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1.
It is generally assumed that chronic glucocorticoid therapy is similar pharmacologically when administered to either black or white renal transplant recipients, resulting in adrenal suppression, low circulating plasma cortisol concentrations, and a similar degree of drug exposure and toxicity. To examine this theory and to investigate the relationship of glucocorticoid metabolism to steroid-induced adverse effects among specific ethnic groups of renal transplant recipients, 9 black and 9 white male patients chronically receiving methylprednisolone were enrolled. All patients had stable renal function and were matched for age, weight, and time since transplant. Standard pharmacokinetic parameters for methylprednisolone were determined and cortisol responses were characterized by total cortisol area under the concentration curve (AUC), return cortisol AUC, and cortisol suppression half-life. All patients received their daily oral dose of methylprednisolone (mean daily dose = 11 mg for blacks and 11 mg for whites) as an intravenous infusion with serial plasma samples obtained over 24 h. The patients were assessed for the presence of specific cushingoid manifestations (buffalo hump, moon facies) and steroid-associated diabetes. Methylprednisolone and cortisol were analyzed via HPLC. In the black patients, the mean clearance of methylprednisolone (206 +/- 70 ml/hr/kg) was significantly slower with a smaller volume of distribution (0.95 +/- 0.32 L/kg) when compared with the white group (327 +/- 129 ml/hr/kg, P = 0.03; volume of distribution = 1.33 +/- 0.27 L/kg, P = 0.015). Despite chronic methylprednisolone therapy, a definite 24-hr cortisol response pattern was noted in 15 of the 18 patients with a mean total cortisol AUC of 732 +/- 443 ng.hr/ml in blacks and 539 +/- 361 ng.hr/ml in whites (P = 0.17, black vs. white). The mean cortisol suppression half-life was 4.31 +/- 1.54 hr in black recipients and 4.11 +/- 1.49 hr in whites (P = 0.48). The mean return cortisol AUC for the black patients was 327 +/- 279 ng.hr/ml and 370 +/- 207 ng.hr/ml for white patients (P = 0.28). The serum cortisol nadir for black patients was 12.3 +/- 7.2 ng/ml, which was significantly higher than the cortisol nadir in white patients (6.4 +/- 4.4 ng/ml; P = 0.03). A majority (94%) of patients (9 black, 8 white) had moon facies and 27% of patients (3 black, 1 white) had a buffalo hump. While 5 of 9 black patients had steroid-associated diabetes, no white patients manifested this adverse effect. The black patients with diabetes had higher cortisol AUCs with lower methylprednisolone clearances than the white group.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   

2.
PURPOSE: To investigate the pharmacokinetics and pharmacodynamics of paclitaxel (P) and carboplatin (C) in a sequence-finding and dose-escalating study in untreated non-small-cell lung cancer (NSCLC) patients. PATIENTS AND METHODS: Fifty-five chemotherapy-naive patients with NSCLC were entered onto the pharmacokinetic part of a large phase I trial in which P was administered as a 3-hour infusion at dosages of 100 to 250 mg/m2, and C over 30 minutes at dosages of 300 to 400 mg/m2. Patients were randomized for the sequence of administration, first C followed by P or vice versa. Each patient received the alternate sequence during the second and subsequent courses. RESULTS: The most important hematologic toxicity encountered-was neutropenia. Hematologic toxicity was not dependent on the sequence in which P and C were administered, but there was cumulative neutropenia. Nonhematologic toxicities consisted mainly of vomiting, myalgia, and arthralgia. No sequence-dependent pharmacokinetic interactions for the P area under the concentration-time curve (P-AUC), maximal plasma concentration (P-Cmax), or time above a threshold concentration of 0.1 mumol/L (P-T > or = 0.1 mumol/L) were observed. However, there was a significant difference for the metabolite 6 alpha-hydroxypaclitaxel AUC (6OHP-AUC). Higher 6OHP-AUCs were observed when C was administered before P. The mean plasma ultrafiltrate AUC of C (CpUF-AUC) at the dosage of 300 mg/m2 for the sequence C-->P was 3.52 mg/mL.min (range, 1.94 to 5.83) and 3.62 mg/mL.min for the sequence P-->C (range, 1.91 to 5.01), which is not significantly different (P = .55). Of 45 assessable patients, there were five major responders (three complete responders and two partial responders). Four of five responses occurred at dosages above dose level 4 (P 175 mg/m2 + C 300 mg/m2). The median survival duration was best correlated with the P dose (4.8 months for doses < 175 mg/m2 v 7.9 months for doses > or = 175 mg/m2, P = .07; P-T > or = 0.1 mumol/L, 4.8 months for < 15 hours v 8.2 months for > or = 15 hours, P = .06). CONCLUSION: There was no pharmacokinetic-sequence interaction between C and P in this study. A clear dose-response relation with respect to response rate and survival was observed. The pharmacokinetic parameter P-T > or = 0.1 mumol/L was related to improved survival in this study.  相似文献   

3.
BACKGROUND: Mycophenolate mofetil (MMF) is rapidly hydrolyzed to its active metabolite mycophenolic acid (MPA), which is excreted by the kidney after undergoing glucuronidation to MPAG. MPAG has been shown to accumulate in patients with renal failure. MPA is extensively and avidly bound to human serum albumin. In vitro inhibition of the pharmacologic target, inosine monophosphate dehydrogenase, is dependent on free MPA. It has been demonstrated that high MPAG concentrations decrease MPA protein binding in vitro. In addition, the uremic state is associated with altered protein binding of many drugs. METHODS: We assessed free MPA, total MPA, and MPAG kinetics in a patient with renal failure receiving MMF for a pancreas transplant, who presented with signs of MMF toxicity. MPA, MPAG, and free MPA were measured by high performance liquid chromatography and a validated 14C-MPA ultrafiltration methodology. RESULTS: The MPAG area under the concentration curve (AUC) in this patient was extremely high (5899 microg x hr/ml). The total MPA AUC of 36.8 microg x hr/ml was within the range usually obtained in stable renal patients. The free fraction of MPA and the free MPA AUC were markedly elevated (13.8% and 5.07 microg x hr/ml, respectively). CONCLUSIONS: Patients with severe renal insufficiency may have markedly increased free MPA levels that may not be reflected in total MPA concentrations. These patients may be at increased risk for MMF-related toxicity.  相似文献   

4.
PURPOSE: To determine the toxicities, pharmacokinetics, and recommended doses of the topoisomerase I inhibitor, topotecan, in patients with varying degrees of renal excretory dysfunction. PATIENTS AND METHODS: Fourteen patients with normal renal function [creatinine clearance (CrCl) > or = 60 mL/min] and 28 patients with varying degrees of renal dysfunction were treated with topotecan 0.4 to 2.0 mg/m2/d as a 30-minute infusion for 5 consecutive days every 3 weeks. Plasma and urine samples were obtained to determine the disposition of topotecan. RESULTS: In patients with mild renal dysfunction (CrCl = 40 to 59 mL/min), dose-limiting hematologic toxicity was observed in three of eight patients receiving topotecan 1.0 mg/m2/d and in two of five patients receiving topotecan 1.5 mg/m2/d. In patients with moderate renal dysfunction (CrCl = 20 to 39 mL/min), dose-limiting hematologic toxicity was observed in three of eight patients who received topotecan 0.5 mg/m2/d, and in two of four patients receiving topotecan 1.0 mg/m2/d; these events were more frequently observed in extensively pretreated patients. Pharmacokinetic analyses showed significant correlations between CrCl and the plasma clearance of both total topotecan [Spearman's correlation coefficient (r2) = 0.65, P = .00001] and topotecan lactone (r2 = 0.65, P = .00003). Mean systemic plasma clearance of total topotecan was significantly reduced in patients with mild (P = .04) and moderate (P = .00006) renal dysfunction. There was no evidence of changes in the pharmacodynamic relationship between topotecan exposure (AUC) and myelotoxicity. CONCLUSION: Dose adjustments are required in patients with moderate, but not mild, renal impairment. For patients with moderate renal dysfunction, the recommended starting dose of topotecan is 0.75 mg/m2/d for 5 days every 3 weeks. Moreover, extensively pretreated patients need further dose reductions.  相似文献   

5.
i.p. administration of cytotoxic drugs for the treatment of regionally confined cancers results in a greater total drug exposure [area under the concentration x time curve (AUC)] for the peritoneal fluid and regional lymphatics than for plasma. We sought to augment the relative advantage of i.p. administration further through modulation of peritoneal clearance by reduction in splanchnic blood flow. Pigs were treated with 5-fluorouracil, etoposide (VP-16), and carboplatin (CBDCA) alone by the i.p. route or with the same drugs in combination with i.v. lypressin, a synthetic vasopressin analogue, which reduces splanchnic blood flow. Drug concentrations in peritoneal fluid, plasma, and thoracic duct lymph were monitored over the ensuing 6 h. The pharmacokinetics of 5-fluorouracil were not altered by vasopressin; however, vasopressin increased the peritoneal fluid:plasma AUC ratio for CBDCA from 30.6 +/- 5.6 to 70. 6 +/- 7.4 (P < 0.01) and increased the lymph:plasma AUC ratio from 1.1 +/- 0.4 to 2.6 +/- 0.22 (P < 0.05). In the case of VP-16, vasopressin increased the peritoneal fluid:plasma AUC ratio from 129 +/- 35 to 350 +/- 76 (P < 0.05) and the lymph:plasma AUC ratio from 2.1 +/- 0.6 to 10.6 +/- 3.5 (P < 0.05). Concurrent i.v. administration of vasopressin can increase the pharmacokinetic advantage of the i.p. route of administration of CBDCA and VP-16 markedly in the pig model. These data suggest that the strategy of concurrent i.p. administration of CBDCA or VP-16 plus an agent that reduces splanchnic blood flow may increase the dose intensity in the abdominal cavity and intraabdominal lymphatic tissue substantially without increasing systemic toxicity.  相似文献   

6.
Weight loss in humans is associated with elevated hypothalamic-pituitary growth hormone (GH) secretion. This study evaluates the effects of weight loss on the hypothalamic-pituitary (GH-releasing hormone [GHRH]-GH) axis in 14 normal-weight (body mass index [BMI], 25+/-1 Kg/m2) subjects, of whom half had undergone a diet-induced weight loss of 14%+/-2% (mean+/-SEM). Insulin-like growth factor-1 (IGF-1), insulin, oral glucose tolerance, leptin, and GH pulse patterns were determined in both groups after weight maintenance for 1 week. Of note, we tested the effects of recent weight loss (3 months) and not a recent dietary intake, since both groups ingested a normal calorie diet for 2 days in the Clinical Research Center (CRC) prestudy. Serum insulin (3.8+/-0.7 v 9.0+/-0.9 microU/mL, P < .01) and C-peptide (0.44+/-0.06 v 0.59+/-0.04 ng/mL, P < .05) were significantly lower in the weight loss group. Serum leptin was not different. Endogenous GH pulse height (11.9+/-4.8 v 1.3+/-0.1 microg/L, P < .05), area per GH pulse ([AUC] 57+/-28 v 6+/-1 microg/L, P < .05), and mean GH (3.91+/-0.76 v 0.85+/-0.16 microg/L, P < .01) were increased in the weight loss group. The serum insulin level was inversely associated with the mean GH concentration (r=-.678, P < .01) and GH pulse height (r=-.733, P < .01). In addition to spontaneous GH secretion, the GHRH-stimulated GH pulse height (41.8+/-18.1 v7.1+/-1.6 microg/L, P < .05) and AUC (161+/-35 v46+/-13 microg/L/min, P < .05) were also increased in the weight loss group. The insulin concentration was also inversely correlated with the GHRH-stimulated GH pulse height (r=-.718, P < .01). The leptin concentration was correlated with the BMI (r=.554, P < .05) and body fat (r=.744, P < .01), but not with GH secretion. In summary, even though these patients were on a normal calorie diet, a history of recent weight loss in young men and women of normal weight and health can be associated with a significant increase in spontaneous GH pulse height and GHRH-stimulated pulse height. Weight loss was also associated with a reduced serum insulin level. The observed increase in GH secretion may be secondary to the reduction in insulin or alterations of other factors acting at the site of the pituitary.  相似文献   

7.
Previous studies in children have shown inconsistent, poorly reproducible GH responses to exogenous GH-releasing factor (GRF), with wide individual variability. In the present study, we tested the hypothesis that prior administration of the long-acting somatostatin analog, SMS 201-995 (SMS), will enhance GH responsiveness to a subsequent GRF challenge. Two study protocols were employed in 37 children with short stature [M = 31, F = 6, ages 11.8 +/- 1.6 yr (mean +/- SEM), height -2.25 +/- 0.55 SDS (SD scores)]. In both studies, each subject served as his/her own control. In the first study, which was designed to determine optimal SMS dose and regimen, SMS, in doses ranging from 0.8-2.2 micrograms/kg sc, was randomly administered or omitted at 0800 h after an overnight fast, and a GRF bolus (50 micrograms, iv) was given 4 h later. In the second study, we employed a protocol identical to study 1 except for the use of standard doses of SMS (1 microgram/kg, sc) and GRF (1 microgram/kg, iv) and an additional 1-h delay of the GRF injection. Plasma GH levels were measured every 20 min from 0800 h until 2 h after the GRF injection in both studies. In study 1 (n = 12; M = 10, F = 2), SMS significantly suppressed spontaneous GH secretion (expressed as the mean +/- SEM GH AUC during the 4-h SMS-GRF interval, AUC 1:2.2 +/- 0.4 vs. 6.2 +/- 0.9 micrograms/L.h; P < 0.001), GH responsiveness to GRF (GH AUC during the 2 h after the GRF injection, AUC 2: 41.5 +/- 7.8 vs. 85.0 +/- 13.5 micrograms/L.h; P < 0.001), and the GH peak response (17.4 +/- 3.1 vs. 36.0 +/- 6.2 micrograms/L; P < 0.001), compared to control tests. In contrast, in study 2 (n = 25; M = 21, F = 4), whereas spontaneous GH secretion was still suppressed during the 5-h SMS-GRF interval (AUC 1:3.8 +/- 0.4 vs. 7.4 +/- 1.1 micrograms/L.h; P < 0.001), both the GH peak response (56.7 +/- 5.5 vs. 30.5 +/- 3.0 micrograms/L; P < 0.0001) and the GH AUC (AUC 2: 103.7 +/- 10.3 vs. 77.5 +/- 6.8 micrograms/L.h; P < 0.05) after GRF administration were significantly augmented by pretreatment with SMS, compared to control tests. Taken together, these results indicate that a priming SMS dose of 1 microgram/kg has a significant permissive effect on GH responsiveness to exogenous GRF administered 5 h later.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   

8.
PURPOSE: We have examined the role of an increase in cisplatin dose-intensity in patients with advanced epithelial ovarian cancer by means of single-agent carboplatin therapy. PATIENTS AND METHODS: Two hundred twenty-seven patients were randomized to treatment and eligible for analysis. The dose of carboplatin was calculated according to the Calvert formula. One hundred seventeen patients received carboplatin at an area under the concentration time curve (AUC) of 6 for six courses, administered every 28 days, and 110 patients received carboplatin at an AUC of 12 for four courses, administered every 28 days. Patients were eligible provided they had not received prior chemotherapy or radiotherapy and had International Federation of Gynecology and Obstetrics stages II to IV or relapsed stage I epithelial ovarian cancer. RESULTS: The planned total-dose increase was 33% for the patients treated with carboplatin AUC 12, but the received percentage total-dose increase was 20%. There were no differences in progression-free or overall survival between the two treatment arms; the overall survival rate at 5 years was 31% and 34% of patients treated at AUCs 6 and 12, respectively. There was significantly more toxicity associated with carboplatin AUC 12, which resulted in more treatment delays and/or dose reductions (52% v 18%; P < .001). CONCLUSION: We have shown that carboplatin can be delivered at an AUC of 12 for four courses without granulocyte colony-stimulating factor support, although significant hematologic toxicity occurs. Nonhematologic toxicities were not clinically significant. Carboplatin offers an opportunity to intensify cisplatin therapy, but a greater than two-fold increase in dose-intensity probably needs to be achieved before significant effects on survival will be produced and hematologic support will be required.  相似文献   

9.
Previous studies have demonstrated that cytochrome P450 2E1 (P450 2E1) catalyzes the oxidation of acetone in vitro. The present study was designed to determine the importance of P450 2E1 in the catabolism of acetone in rats using diallyl sulfide (DAS) as an inhibitor of this enzyme. After a single intragastric dose of DAS, blood samples were collected from rats at different time points, and blood acetone concentrations were measured by gas chromatography. In a low DAS dose (50 mg/kg body weight) group, the maximum acetone level of 6-fold higher than the normal level was reached at 6 hr; the acetone level returned to normal at 48 hr. In a high dose (200 mg/kg) group, the maximum acetone level of 9-fold higher than the normal level was reached at 12 hr; the acetone level returned to normal at 60 hr. The turnover time and fractional turnover rate of elevated acetone were 15.8 +/- 0.5 hr and 0.054 +/- 0.001 hr-1, respectively, for the low dose, and 19.2 +/- 0.6 hr and 0.046 +/- 0.005 hr-1, respectively, for the high dose. In a chronic experiment, DAS (50 and 200 mg/kg, i.g.) was given to rats daily for 29 days, and elevated blood acetone levels were observed during the entire experimental period: 2.0 to 2.8 micrograms/mL for the low dose and 3.4 to 3.9 micrograms/mL for the high dose at 24 hr after the 1st, 7th, 14th and 28th doses versus 0.8 to 0.9 micrograms/mL for the control. The increase of blood acetone level was closely related to the decreases of N-nitrosodimethylamine (NDMA) demethylase activity and P450 2E1 content in liver microsomes. Consistent with the lack of cumulative effect from the multiple doses of DAS on acetone level, rather stable levels of the DAS metabolites, diallyl sulfoxide (45.0 micrograms/mL, range: 33.8 to 58.6 micrograms/mL) and diallyl sulfone (11.7 micrograms/mL, range: 6.9 to 15.6 micrograms/mL), were observed at 24 hr after the 1st, 7th, 21st and 28th doses with DAS (200 mg/kg) in the chronic experiment. It is likely that the inactivation and inhibition of P450 2E1 by DAS and its metabolites block the oxidation of acetone and cause its elevation in blood. The results strongly suggest an important role of P450 2E1 in acetone catabolism under physiological conditions.  相似文献   

10.
To determine the effect of aging on the suppression of GH secretion by insulin-like growth factor (IGF)-I, we studied 11 healthy young adults (6 men, 5 women, mean +/- SD: 25.2 +/- 4.6 yr old; body mass index 23.7 +/- 1.8 kg/m2) and 11 older adults (6 men, 5 women, 69.5 +/- 5.8 yr old; body mass index 24.2 +/- 2.5 kg/m2). Saline (control) or recombinant human IGF-I (rhIGF-I) (2 h baseline then, in sequence, 2.5 h each of 1, 3, and 10 micrograms/kg.h) was infused iv during the last 9.5 h of a 40.5-h fast; serum glucose was clamped within 15% of baseline. Baseline serum GH concentrations (mean +/- SE: 3.3 +/- 0.7 vs. 1.9 +/- 0.5 micrograms/L, P = 0.02) and total IGF-I concentrations (219 +/- 15 vs. 103 +/- 19 micrograms/L, P < 0.01) were higher in the younger subjects. In both age groups, GH concentrations were significantly decreased by 3 and 10 micrograms/kg.h, but not by 1 microgram/kg.h rhIGF-I. The absolute decrease in GH concentrations was greater in young than in older subjects during the 3 and 10 micrograms/kg.h rhIGF-I infusion periods, but both young and older subjects suppressed to a similar GH level during the last hour of the rhIGF-I infusion (0.78 +/- 0.24 microgram/L and 0.61 +/- 0.16 microgram/L, respectively). The older subjects had a greater increase above baseline in serum concentrations of both total (306 +/- 24 vs. 244 +/- 14 micrograms/L, P = 0.04) and free IGF-I (8.5 +/- 1.4 vs. 4.2 +/- 0.6 micrograms/L, P = 0.01) than the young subjects during rhIGF-I infusion, and their GH suppression expressed in relation to increases in both total and free serum IGF-I concentrations was significantly less than in the young subjects. We conclude that the ability of exogenous rhIGF-I to suppress serum GH concentrations declines with increasing age. This suggests that increased sensitivity to endogenous IGF-I negative feedback is not a cause of the decline in GH secretion that occurs with aging.  相似文献   

11.
The elderly have impaired cellular immunity and are more predisposed to opportunistic infections after long term glucocorticoid treatment. No data, examining the response of lymphocyte subsets (CD4+, CD8+) under baseline conditions and after exposure to methylprednisolone in young and elderly males, are available. This crossover study examined lymphocyte subsets and cortisol response patterns in seven elderly males (66-82 years) and five young males (24-37 years) randomized into Phase I (24 hr baseline) and Phase II (10 mg intravenous dose of methylprednisolone). Whole blood samples were obtained at 0, 4, 8, 12 and 24 hr to determine total lymphocytes and CD4+ and CD8+ cells utilizing monoclonal antibodies and flow cytometry. The absolute number of lymphocyte subsets and the lymphocyte area under the time curve (AUC) were measured and a 12 and 24 hr lymphocyte response ratio (AUC Phase II divided by AUC Phase I) was determined. Serial plasma samples over 24 hours were collected to quantitate cortisol (Phase I) and methylprednisolone concurrent with cortisol (Phase II). Pharmacokinetic parameters were generated and the cortisol AUC was determined. The AUC values for lymphocytes and cortisol from Phase II quantitated the pharmacologic response to methylprednisolone exposure while Phase I data described the interpatient variability in these parameters. Diurnal patterns for lymphocytes and cortisol were noted in all subjects during Phase I. The mean CD4+ and CD8+ lymphocyte AUC from 0 to 24 hr during Phase I was significantly smaller for the elderly when compared to young men. However, after exposure to methylprednisolone, lymphopenia occurred in all subjects with a mean decline of 54% in the elderly and 60% (p = 0.44) in young subjects for the total lymphocyte count and returned to baseline by 8-12 hr. During Phase II, the CD4+ lymphocytes (72% decline in elderly; 70% in young; p = 0.71) demonstrated a more notable decline than CD8+ cells (44% decline in elderly; 52% in young; p = 0.31) with a nadir occurring between 4 to 6 hr for both subsets. The lymphocyte response ratio was not significantly different between groups for total, CD4+, and CD8+ cells at 12 hr or 24 hr determinations. A slower clearance of methylprednisolone was noted in the elderly (mean: 256 mL/hr/Kg) than in the young men (mean: 359 mL/hr/Kg; p < 0.05) during Phase II with no significant difference found between groups for volume of distribution, elimination rate constant or half-life. A significantly smaller cortisol suppression ratio [0.36+/-0.11 (elderly) versus 0.58+/-0.11 (young), p = 0.01] which indicates a more profound cortisol suppression was noted. A significant correlation of -0.61 (p < 0.05) between drug exposure (methylprednisolone AUC) and pharmacologic effect (cortisol suppression ratio) was noted for the combined data in the young and elderly males. During Phase I, the CD4+ and CD8+ lymphocyte AUC was significantly smaller in the elderly. A definite suppression pattern for total, CD4+ and CD8+ lymphocytes and cortisol was noted after methylprednisolone exposure in young and elderly males. An age-dependent suppression of cortisol during Phase II was noted but the degree of lymphopenia after drug exposure did not differ between the young and elderly group for any of the cell subsets. These data from healthy elderly provide a basis for further studies to assess immunologic and endocrinologic responses among elderly patients requiring chronic glucocorticoid therapy.  相似文献   

12.
PURPOSE: In two sequential phase II studies, we evaluate the feasibility and efficacy of adding paclitaxel to a standard platinum/etoposide regimen in the first-line treatment of small-cell lung cancer. PATIENTS AND METHODS: One hundred seventeen patients with small-cell lung cancer were treated between June 1993 and July 1996. The first 38 patients received a lower-dose regimen: paclitaxel 135 mg/m2 by 1-hour infusion, carboplatin at an area under the concentration-time curve (AUC) of 5.0, and etoposide 50 mg alternating with 100 mg orally on days 1 to 10. When only mild myelosuppression was observed, doses of paclitaxel and carboplatin were increased in the subsequent 79 patients (paclitaxel 200 mg/m2 by 1-hour infusion and carboplatin at an AUC of 6.0). All patients received four courses of treatment, administered at 21-day intervals. Patients with limited-stage small-cell lung cancer also received thoracic radiation therapy (1.8 Gy/d; total dose, 45 Gy) administered concurrently with courses 3 and 4 of chemotherapy. RESULTS: Seventy-two of 79 patients (91%) who receive the higher-dose regimen had major responses. Thirty-two of 38 (84%) with extensive-stage disease responded (21% complete response rate); median survival was 10 months for this group. With limited-stage disease, the overall response rate was 98%, with 71% complete responses; the median survival time has not been reached at 16 months. Median survival in extensive-stage patients was longer in patients who received the higher-dose regimen (10 months) than in the previous group treated with lower doses (7 months; P = .008). The higher-dose regimen was well tolerated, with myelosuppression being the major toxicity. Compared with the lower-dose regimen, grade 3/4 neutropenia increased from 8% to 38% of courses, but the incidence of hospitalization for neutropenia and fever did not increase. Other nonhematologic toxicities were uncommon, and did not increase substantially with the higher-dose regimen. CONCLUSION: Paclitaxel can be added at full dose (200 mg/m2) to a carboplatin/etoposide combination while maintaining a tolerable toxicity profile. Median survival times in both extensive- and limited-stage patients compare favorably with other reported regimens. This regimen merits further investigation, and a randomized trial to compare this regimen with a standard carboplatin/etoposide combination is underway.  相似文献   

13.
It is widely accepted that, in man, galanin, a neuropeptide, has a clear GH-releasing effect while its stimulatory influence on PRL secretion is matter of debate. To clarify this point, in 6 normal young women (23-35 yr) in their early follicular phase, we studied the effect of galanin (pGAL, 80 pmol/kg. min infused i.v. over 60 min) on both basal and arginine (ARG, 0.5 g/kg i.v. in 30 min), TRH (400 micrograms i.v. as a bolus at 0 min) or metoclopramide (MCP, 10 mg i.v. as a bolus at 0 min)-stimulated PRL secretion. GAL infusion failed to significantly increase basal PRL levels (peak vs baseline: 12.2 +/- 3.6 vs 8.7 +/- 1.2 micrograms/L) but counteracted the spontaneous PRL decrease observed during saline infusion (AUC: 1216.6 +/- 282.1 vs 672.0 +/- 94.5 micrograms.min/L; p < 0.05). GAL infusion clearly enhanced the PRL response to TRH (AUC: 5806.3 +/- 743.0 vs 3952.1 +/- 423.9 micrograms.min/L, p < 0.05) and ARG (AUC: 3676.8 +/- 382.6 vs 2638.9 +/- 287.0 micrograms.min/L, p < 0.05), respectively. On the other hand, GAL failed to modify the MCP-induced PRL response (AUC: 15409.5 +/- 2085.3 vs 14,787.9 +/- 2045.5 micrograms.min/L). The PRL response to MCP was higher than that to TRH (p < 0.01) which, in turn, was higher than that to ARG (p < 0.01). During GAL infusion, the PRL response to TRH or ARG remained lower (p < 0.01) than that after MCP administration. Thus, in conclusion, present data demonstrate that in normal women galanin enhances the PRL response to ARG and TRH but fails to modify that induced by dopamine receptor blockade with metoclopramide. Based on evidence that the inhibition of central dopaminergic activity inhibits the lactotrope responsiveness to dopaminergic antagonists or TRH, it is unlikely that galanin influences PRL secretion via inhibition of dopaminergic tone.  相似文献   

14.
To determine whether peptides of the insulin-like growth factor (IGF) system might be useful indicators of nutritional adequacy in premature infants, we studied 50 premature (25-34 weeks gestation) infants prospectively to define the relationship between nutrient intake and serum concentrations of IGF-I, IGF-binding protein-2 (IGFBP-2), and IGFBP-3. Each infant was monitored for at least 2 weeks. Nutrient intake was quantified from daily logs; weight was determined daily, and measurements of IGF-I, IGFBP-2, and IGFBP-3 in serum were made twice weekly. Serum IGF-I correlated strongly with length of gestation, increasing 4.03 +/- 0.95 ng/mL for each additional week of gestation (P < 0.0001) and 0.36 +/- 0.07 ng/mL day each day since birth (P < 0.0001). A higher intake of calories increased IGF-I by 0.07 +/- 0.01 ng/mL for each calorie per kg ingested over the previous 3 days (P < 0.0001). IGF-I increased quadratically as protein intake increased. For each change of 1% in calories as protein squared, IGF-I increased 0.36 +/- 0.11 ng/mL (P < 0.0001). Serum IGFBP-3 concentrations also correlated with length of gestation, increasing 25.06 +/- 11.83 micrograms/L.wk (P = 0.035) and 4.14 +/- 1.33 micrograms/.day since birth (P = 0.003). Unlike IGF-I, variation in the amount of protein supplied did not change IGFBP-3. As calorie intake increased, IGFBP-3 increased by 0.54 +/- 0.17 microgram/L for each calorie per kg consumed over the previous 3 days (P = 0.0015). In contrast to IGF-I and IGFBP-3, IGFBP-2 declined as the length of gestation increased (56.12 +/- 16.92 ng/mL.week; P = 0.001) and with each additional day of life (7.57 +/- 2.44 ng/mL.day; P = 0.003). Dietary protein, the predominant regulator of IGFBP-2, caused a decrease of 33.22 +/- 9.00 ng/mL with each percent increase in dietary calories as protein (P < 0.0003). Calorie intake had less effect on IGFBP-2 than protein intake. These results indicate that each of the three peptides studied is regulated in premature infants by nutritional intake, and that their regulatory patterns are qualitatively similar to those observed in older individuals. Measurements of these peptides in premature infants may be useful indicators of nutritional status and adequacy of nutrient intake.  相似文献   

15.
We examined the relationships among gender, sexual maturation, four-compartment model estimates of body composition, body fat distribution (magnetic resonance imaging for abdominal visceral fat and anthropometrics), aerobic fitness, basal and total energy expenditure, and overnight GH release in an ultrasensitive chemiluminescence assay in healthy prepubertal and pubertal boys (n = 18 and 11, respectively) and girls (n = 12 and 18, respectively). Blood samples were withdrawn every 10 min from 1800-0600 h to determine the area under the serum GH-time curve (AUC), sum of the GH peak heights (sigma GH peak heights), and the mean nadir GH concentration. GH release was greater in the pubertal than prepubertal subjects due to an increase in sigma GH peak heights (43.8 +/- 3.6 vs. 24.1 +/- 3.5 ng.mL-1, P = 0.0002) and mean nadir (1.7 +/- 0.2 vs. 0.7 +/- 0.2 ng.mL-1, P = 0.0002), but not peak number (4.3 +/- 0.2 vs. 4.5 +/- 0.2). The girls had a greater sigma GH peak heights (39.0 +/- 3.5 vs. 28.8 +/- 3.6 ng.mL-1, P = 0.05) and mean nadir concentration (1.4 +/- 0.2 vs. 0.9 +/- 0.2 ng.mL-1, P = 0.05) than the boys. Significant inverse relationships existed between sigma GH peak heights (r = -0.35, P = 0.06) or mean nadir (r = -0.39, P = 0.04) and four-compartment percent body fat for all boys but not for all girls or when combining all subjects. For all girls, significant inverse relationships existed between sigma GH peak heights (r = -0.39, P = 0.03) or mean nadir (r = -0.37, P = 0.04) and waist/hip ratio. Similar inverse relationships in all boys or all subjects were not significant. Forward stepwise regression analysis determined that bone age (i.e. maturation, primary factor) and gender were the significant predictors of AUC, sigma GH peak heights, and mean nadir. The influence of maturation reflects rising sex steroid concentrations, and the gender differences appear to be because of differences in estradiol concentrations rather than to body composition or body fat distribution.  相似文献   

16.
PURPOSE: The primary objectives of the study were to evaluate the efficacy and safety of prolonged oral (PO) etoposide as part of cisplatin-based chemotherapy plus concurrent chest/brain irradiation induction, followed by CAV consolidation, in the treatment of patients with limited-stage small cell lung cancer (SCLC-LD) within a cooperative group setting. METHODS AND MATERIALS: Fifty-six eligible patients with SCLC-LD received three 28-day cycles of cisplatin 50 mg/m2 i.v. (days 1, 8; 29, 36; and 57, 64), PO etoposide 50 mg/m2 (days 1-14, 29-42, and 57-70), and vincristine 2 mg i.v. (days 1, 29, and 57). Thoracic irradiation (TRT) was administered at 1.8 Gy in 25 daily fractions to a total dose of 45 Gy via an AP:PA arrangement, to begin concomitantly with induction chemotherapy. Prophylactic cranial irradiation (PCI) was started on day 15 of induction therapy. Fifteen daily fractions of 2.0 Gy were administered to the entire brain to a total dose of 30 Gy to finish at approximately the same time as TRT. Two 21-day cycles of consolidation cyclophosphamide 750 mg/m2 i.v., doxorubicin 50 mg/m2 i.v., and vincristine 2 mg i.v. (all on days 1 and 22), were given beginning on day 106 or week 16, from the start of induction therapy. RESULTS: Among 56 eligible patients, 93% had SWOG performance status 0-1. All had adequate organ function and had not received prior therapy. The overall confirmed response rate was 46%, including 16% complete responders and 30% partial responders. After a minimum follow-up duration of 17 months, the Kaplan-Meier median progression-free (PFS) and overall survival (OS) were 10 and 15 months, respectively. Two-year survival is 28%. Only 28 of 56 patients (50%) completed chemotherapy per protocol, while 52 of 56 patients (93%) completed radiation per protocol. Eleven patients (20%) discontinued secondary to toxicity and two patients died from treatment. The major toxicity was hematologic. The two deaths were secondary to infection. Of the nonhematologic toxicities, there were 10 cases of pulmonary fibrosis (including one Grade 3) and six cases of pneumonitis (including one Grade 3). CONCLUSION: Concomitant chemoradiation with oral etoposide as part of a platinum-based chemotherapy and TRT induction regimen is toxic. The CR rate is not better than our prior best group-wide experience. The progression-free and overall survival are similar to published trials utilizing short-course i.v. etoposide. As in chemotherapy for extensive-stage SCLC, there is no apparent advantage to prolonged exposure to etoposide, and toxicity resulted in an inferior therapeutic index compared to programs with shortened exposure.  相似文献   

17.
Two lysosomal storage diseases, aspartylglucosaminuria and mannosidosis, are associated with highly elevated serum dolichol concentrations. To elucidate possible mechanisms leading to elevated serum dolichols, we studied the effects of Triton WR 1339 (known to increase serum cholesterol) and orotic acid (known to decrease serum cholesterol) on blood and biliary dolichol and beta-hexosaminidase levels in rats. In Triton WR 1339-treated rats, serum dolichol was markedly increased compared with saline-treated controls 1 (400 +/- 70 ng/mL, n = 7 v 85 +/- 11 ng/mL, n = 8, P < .001), 4 (789 +/- 70 ng/mL, n = 10 v 110 +/- 10 ng/mL, n = 7, P < .0001), and 8 (549 +/- 43 ng/mL, n = 8 v 87 +/- 8 ng/mL, n = 7, P < .001) days after administration of the drug. By contrast, serum dolichol was decreased (64 +/- 5 ng/mL, n = 8 v 119 +/- 7 ng/mL, n = 8, P < .0001) after a 7-day orotic acid feeding compared with controls. Serum beta-hexosaminidase was unaffected by both treatments. Orotic acid also increased biliary dolichol (280 +/- 47 ng/100 g body weight [BW]/h, n = 7 v 83 +/- 15 ng/100 g BW/h, n = 7, P < .01) and beta-hexosaminidase (21 +/- 3 mU/100 g BW/h, n = 7 v 8.3 +/- 2 mU/100 g BW/h, n = 9, P < .01) excretion compared with controls. Thus, both Triton WR 1339 and orotic acid have an effect on dolichol metabolism, and it is conceivable--based on our results--that serum dolichol concentrations are regulated, at least in part, by a mechanism similar to that for serum cholesterol levels.  相似文献   

18.
PURPOSE: The aim of this randomized trial was to assess the potential therapeutic advantage of an intensive induction-sequential chemotherapy schedule (bleomycin, vincristine, cisplatin [BOP])/etoposide, ifosfamide, cisplatin, and bleomycin [VIP-B]), compared with a regimen based on bleomycin, etoposide, and cisplatin (BEP) (BEP/etoposide and cisplatin [EP]) for the treatment of patients with poor-prognosis metastatic nonseminomatous germ cell tumors (NSGCTs). PATIENTS AND METHODS: Patients had one or more of the following: a retroperitoneal mass > or = 10 cm in diameter; mediastinal or supraclavicular mass > or = 5 cm in diameter; at least 20 lung metastases (any size); liver, bone, or brain metastases; and serum beta human chorionic gonadotropin (betaHCG) > or = 10,000 IU/L or alfa fetoprotein (AFP) > or = 1,000 IU/L. A total of 380 patients were accrued between May 1990 and June 1994 into this joint Medical Research Council (MRC)/European Organization for Research and Treatment of Cancer (EORTC) trial; of these, nine patients were deemed ineligible. RESULTS: There was no significant difference between the two arms in the proportion of patients who achieved a complete response (CR) with chemotherapy alone, ie, 79 of 185 assessable patients (57%) with BEP/EP and 72 of 186 (54%) with BOP/VIP-B (P = 0.687). With a median follow-up of 3.1 years (maximum, 5.8), a total of 107 patients (28%) had progressive disease. There was no significant difference in time to first disease progression, or failure-free or overall survival between the two arms (P = 0.21, 0.101, and 0.190, respectively). The 1-year failure-free survival rates for BEP/EP and BOP/VIP-B were 60% (95% confidence interval [CI], 53% to 67%) and 53% (95% CI, 47% to 61%). Grade 3 or 4 myelosuppression, febrile neutropenia, and weight loss were more pronounced with BOP/VIP-B than with BEP/EP, and there were more toxic deaths with BOP/VIP-B than BEP/EP (18 [9%] v nine [5%]). CONCLUSION: The intensive BOP/VIP-B therapy was associated with more toxicity, but there was no evidence of an improvement in response rate or survival compared with treatment with BEP/EP.  相似文献   

19.
We investigated the effect of chronic exposure (3 days) with low-density lipoprotein (LDL) and oxidized (Ox)-LDL on the unstimulated and stimulated formation of prostacyclin (6-keto-prostaglandin [PG]F1 alpha) and total inositol phosphates (IPs) by cultured bovine aortic endothelial cells. Neither basal nor bradykinin-stimulated (1 to 10 nmol/L) formation of 6-keto-PGF1 alpha was affected by LDL, except at the highest concentration of bradykinin tested (100 nmol/L). In the presence of the antioxidants N-acetyl-L-cysteine (NAC, 10 mumol/L) or vitamin E (100 mumol/L), basal and bradykinin-stimulated formation of 6-keto-PGF1 alpha was potentiated by 20 micrograms protein/mL of LDL. Ox-LDL decreased unstimulated formation of the eicosanoid from 3.1 +/- 0.2 pg/micrograms protein in control cells to 1.6 +/- 0.1 and 0.5 +/- 0.1 pg/microgram protein after 3-day incubation with 5 and 20 micrograms protein/mL of Ox-LDL, respectively (P < .05). As in the basal state, Ox-LDL decreased bradykinin-induced 6-keto-PGF1 alpha formation. NAC or vitamin E did not influence Ox-LDL-induced endothelial cell changes in eicosanoid production. IPs formation by endothelial cells increased to a similar extent in the presence of 20 micrograms protein/mL of either LDL or Ox-LDL. However, no change was apparent in the bradykinin (10 mumol/L)-induced increase in total IPs formation after incubation with the lipoproteins. The data indicate that chronic exposure to Ox-LDL abolishes the production of prostacyclin by cultured endothelial cells. The oxidatively modified lipoprotein seems to more specifically affect the prostacyclin pathway.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

20.
PURPOSE: A Phase II study to evaluate the effect of a five-drug regimen, VP-16, ifosfamide, cisplatin, vinblastine, and bleomycin (VIP/VB) on complete response rate, continuous disease-free survival, and toxicity in patients with advanced germ-cell tumor. PATIENTS AND METHODS: Twenty male patients with a histologic diagnosis of advanced-stage germ-cell cancer, previously untreated with chemotherapy, received the following: etoposide 75 mg/m2 i.v. days 1-5; ifosfamide (with mesna uroprotection) 1.2 g/m2 i.v. days 1-5; cisplatin 20 mg/m2 i.v. days 1-5; vinblastine 0.18 mg/kg i.v. day 1; bleomycin 30 units i.v. day 1; filgrastim 5 micrograms/kg days 7-16. Chemotherapy was given every 3 weeks (bleomycin weekly x 12) for four courses. RESULTS: All patients entered were evaluable for toxicity, response, and survival. Eleven of 20 (55%) achieved complete remissions with chemotherapy alone and an additional 5 (25%) were rendered disease-free with surgical resection of teratoma (3) or viable cancer (2). Two patients relapsed at 4 and 5 months from complete remission (CR). There was one treatment-related death, from bleomycin lung toxicity after thoracotomy. Thirteen patients (65%) are alive and continuously free of disease, with a median follow-up of 20 months and a minimal follow-up of 12 months. Hematologic toxicity was most common, with 16 patients (80%) having grade 3 or 4 leukopenia. CONCLUSIONS: VIP/VB appears to be a very active regimen in advanced disseminated germ-cell cancer. Hematological toxicity was severe but manageable.  相似文献   

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