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71.
Previously, we demonstrated elevated cortisol production/release in response to the administration of the serotonin precursor, L-5-hydroxytryptophan (L-5-HTP) in untreated patients with obstructive sleep apnea (OSA). We hypothesized that if this elevated cortisol response to L-5-HTP was related to OSA, this finding would not be present in OSA patients treated with nasal continuous positive airway pressure (nCPAP). Eleven OSA patients treated for at least 1 month with nCPAP were studied. On two different days, we measured blood cortisol level every 15 min for 4 h following the ingestion of L-5-HTP, 0.4 mg/kg, or placebo, both given with carbidopa, a peripheral tryptophan decarboxylase inhibitor, used to prevent peripheral L-5-HTP metabolism before brain absorption. For a given subject, the cortisol response was calculated as the difference between the area under the curve of the L-5-HTP and placebo responses. In the nCPAP-treated OSA patients, this net cortisol response, 577 +/- 240 min.micrograms/dL, was less than the value found in the previously studied untreated OSA group, 1,198 +/- 227 min.micrograms/dL (p < 0.05) and not different from the previously studied nonapneic control group, 469 +/- 154 min.micrograms/dL. From these results, we speculate that nCPAP treatment reverses the elevated cortisol response to serotonergic stimulation seen in untreated OSA patients. 相似文献
72.
NM Horlock GD Wilson FM Daley PI Richman R Sanders 《Canadian Metallurgical Quarterly》1997,23(3):247-252
The authors conducted a retrospective study of 80 cases of pressure sores of the pelvic girdle. This study was designed to evaluate the therapeutic approach, surgical reconstruction techniques and their results at 1 year. Only 32 patients (40%) underwent surgical reconstruction, always using regional pedicled myocutaneous flaps. 15.6% of these patients developed a local recurrence (5/32). Analysis of the results of this series shows that failures of reconstruction cannot be attributed to surgical techniques, but to their indications. The reduction of recurrences depends on earlier medical and surgical management and more rigorous patient selection, especially concerning psychological aspects. The patient's cooperation is an essential condition to the success of treatment. 相似文献
73.
The basis for the medical treatment of prostate cancer is inhibition of the influence of testosterone on the prostate. Surgical castration is in 1997 still the gold standard; it reduces the testosterone level by 90% and the level of dihydrotestosterone (the active metabolite) by 60%. In the eighties luteinising hormone releasing hormone (LH-RH) analogues were introduced to avoid the psychological burden of castration. After an initial stimulation (the flare-up) testosterone decreases to castrate level within 3 weeks. Recently (non-steroidal) anti-androgens, competitive inhibitors of dihydrotestosterone on receptor level were introduced. There are also drugs which inhibit the conversion of testosterone to dihydrotestosterone: 5 alpha-reductase inhibitors. Non-steroidal anti-androgens and 5 alpha-reductase inhibitors do not decrease the testosterone level and therefore cause less loss of libido and energy than castration. Combination of (chemical) castration and anti-androgens is called maximum androgen blockade. This treatment has limited additional value in proportion to the increase in side effects and costs. A new form of treatment is intermittent androgen blockade. With this strategy growth of hormone-insensitive cells in the prostate, which is considered the main determinant of the poor prognosis, might be delayed with reduction of side effects and costs. The role of imidazoles is still investigated; the role of cytotoxic drugs is mainly palliative. 相似文献
74.
Juvenile rats are more susceptible to the acute toxicity of the phosphorothionate insecticides parathion and chlorpyrifos than are adult rats. Developmental changes in brain acetylcholinesterase and hepatic aliesterase (carboxylesterase), cytochrome P450, and the P450-mediated metabolism of these two phosphorothionate insecticides were investigated in male Sprague-Dawley rats. Specific activities of acetylcholinesterase in cerebral cortex, but not medulla oblongata, and of liver aliesterases increased with age, indicating the presence of both more target esterases and more protective esterases, respectively, in the adult compared to the juvenile animal. Sensitivity of the brain acetylcholinesterase to inhibition by paraoxon and chlorpyrifosoxon, as measured by IC50 values, did not change significantly with age, whereas the hepatic aliesterase sensitivity to inhibition decreased with age. Progressive increases in activities of P450-mediated activation (desulfuration) (6- to 14-fold) and detoxication (dearylation) (2- to 4-fold), as well as concentrations of P450 (7-fold) and protein (2-fold), were observed between neonate and adult hepatic microsomes. Microsomal pentoxyresorufin O-dealkylase activity followed a developmental pattern similar to desulfuration and dearylation, displaying a 16-fold increase between neonates and adults. However, microsomal ethoxyresorufin O-deethylase activity increased until 21 days of age, displaying a 16-fold increase, then decreased in adulthood to a level 10-fold higher than neonates. These results indicate that target enzyme sensitivity is not responsible for age-related toxicity differences, nor is the potential for hepatic bioactivation, whereas lower levels of hepatic aliesterase-mediated protection and P450-mediated dearylation probably contribute significantly to the greater sensitivity of juveniles to phosphorothionate toxicity. 相似文献
75.
76.
FM Reischies B Geiselmann R Gessner S Kanowski M Wagner F Wernicke H Helmchen 《Canadian Metallurgical Quarterly》1997,68(9):719-729
The frequency of dementia in very old subjects, the risk factors and the consequences of the disease were investigated in the Berlin Aging Study in an age- and gender-stratified design (ages 70-103 years, n = 516). Psychiatrists diagnosed a dementia syndrome according to DSM-III-R, applying the GMS-A and HAS interviews. The dementia frequency steeply increases until the 90-94 year group, but there is no further exponential increase for the 95+ group--instead for men the data show a plateau of dementia prevalence. Low education level turned out to be a risk factor, which explains the gender effect in a logistic regression analysis. The apolipoprotein E4 genotype was confirmed as a risk factor--however, only for the older subjects (85+). Dementia was a major reason for institutionalization. The 2-year mortality was no higher in dementia than for age-matched non-demented controls. The results gave a detailed picture of dementia in the very old. This is a prerequisite for planning facilities for psychiatric diagnostics and therapy as well as nursing care. 相似文献
77.
FM Hecht J Wheat AH Korzun R Hafner KJ Skahan R Larsen MT Limjoco M Simpson D Schneider MC Keefer R Clark KK Lai JM Jacobson K Squires JA Bartlett W Powderly 《Canadian Metallurgical Quarterly》1997,16(2):100-107
The expression of cytokeratins (CKs) in normal cervical epithelium, low grade squamous intraepithelial lesions (SIL), high grade SILs and squamous cell carcinoma (SCC) were analyzed using four different monoclonal antikeratin antibodies. In normal cervical epithelium, CK 18 showed strong immunoreactivity in basal and parabasal layers. CK 19 and 14 were expressed only in the basal layer while CK 13 was found selectively n the spinal cells. As the lesions progressed from low grade SIL to high grade SIL, immunoreactivity of CK 18, 19 and 14 in the basal cell compartment increased while the expression of CK 13 decreased. In SCC, as well-differentiated tumors showed decreased immunoreactivity for CK 18, 19 and 14 with CK 13 showing a strong and focal (localized) immunoreactivity. Undifferentiated carcinomas totally lacked CK 13 reactivity. Our findings therefore suggest that expression of CK 18, 19 and 14 may be directly related to tumor grade and CK 13 may be a marker of differentiation in cervical lesions. 相似文献
78.
79.
80.
JL Grem N McAtee RF Murphy FM Balis E Cullen AP Chen JM Hamilton SM Steinberg M Quinn JM Sorensen SG Arbuck D Lawrence J Pang CJ Allegra 《Canadian Metallurgical Quarterly》1997,3(7):1125-1134
The combination of IFN-alpha-2a (IFN-alpha) and IFN-gamma-1b (IFN-gamma) has been found to produce more than additive cytotoxicity with fluorouracil (5-FU) in HT 29 colon cancer cells due to enhanced DNA-directed effects. We therefore studied the combination of IFN-gamma with IFN-alpha, 5-FU, and leucovorin (LV) in a clinical trial. Fifty-three patients received an initial cycle of 5 million units (MU)/m2 IFN-alpha s.c. on days 1-7 with 500 mg/m2 LV and 370 mg/m2 5-FU i.v. on days 2-6. IFN-gamma was then added once tolerable doses of 5-FU and IFN-alpha were established for each patient. IFN-gamma was administered at one of six dose levels between 0.3-4.8 MU/m2 s.c. on days 1-7. This design permitted comparison of the clinical toxicity and pharmacokinetics of 5-FU in two consecutive cycles in an individual treated with the same doses of 5-FU/LV/IFN-alpha in the absence and presence of IFN-gamma. In 43 matched patient cycles, the addition of IFN-gamma did not seem to worsen gastrointestinal toxicity, and skin toxicity tended to be milder. 5-FU clearance was higher in 14 cycles with IFN-gamma compared to the patient's prior cycle with the same doses of 5-FU/LV/IFN-alpha: 798 +/- 309 versus 601 +/- 250 ml/min/m2 (mean +/- SD; P = 0.04). In these 28 cycles, the median 5-FU clearance was significantly lower in 11 cycles that were complicated by more severe diarrhea: 524 versus 798 ml/min/m2 (grade 2 versus 0-1; P = 0. 0032). Overall, 38% and 26% of patients had grade 3-4 diarrhea and mucositis. Dose reductions of IFN-gamma for chronic fatigue, malaise, or anorexia were ultimately required more frequently with >/=2.4 MU/m2 (P = 0.018), and the maximum tolerated dose of IFN-gamma was considered to be 1.2 MU/m2/ day. Objective responses were seen in 41% of 29 measurable colorectal cancer patients. Compared to our previous experience with 5-FU/LV/IFN-alpha, IFN-gamma and IFN-alpha appeared to have opposite effects on 5-FU clearance. These results suggest that any potential benefit of adding IFN-alpha to 5-FU/LV on this schedule may not depend solely on alterations in 5-FU clearance. 相似文献