Gastric versus duodenal feeding and gastric tonometric measurements

OBJECTIVE: To compare the influence of gastric and postpyloric enteral feeding on the gastric tonometric PCO2 gap (tonometric PCO2 - PaCO2). DESIGN: A prospective, clinical trial. SETTING: Two intensive care units in a university hospital. PATIENTS: Twenty patients undergoing mechanical ventilation and enteral feeding without catecholamines, sepsis, or sign of hypoxia. INTERVENTIONS: Patients were randomized to receive feeding through the tonometer (gastric group), or through a postpyloric tube (postpyloric group). MEASUREMENTS AND MAIN RESULTS: The patients received tube feeding at a rate of 50 mL/hr during 4 hrs. Baseline measurements included: mean arterial pressure, heart rate, tonometric parameters, arterial gases, and arterial lactate concentration. Except for lactate concentration, these measurements were repeated after 1 and 4 hrs of enteral feeding and 2 hrs after stopping enteral feeding. During the study, arterial pH and PaCO2 did not change. During enteral feeding, the PCO2 gap increased in the gastric group from a mean of 7+/-5 to 17+/-14 (SD) torr (0.9 0.7 to 2.3+/-1.9 kPa) (p< .O01) and did not change in the postpyloric group (5+/-5 to 3+/-1 torr [0.7+/-0.7 to 0.4+/-0.1 kPa]). Two hours after stopping enteral feeding, the PCO2 gap was still increased in the gastric group (15+/-9 vs. 7+/-5 torr [2.0+/-1.2 vs. 0.9+/-0.7 kPa]) (p < .01). CONCLUSION: The results indicate that gastric enteral feeding increased the PCO2 gap. However, postpyloric enteral feeding does not interact with gastric tonometric measurements and should be used when using gastric tonometry in enterally fed patients.     

Oestrus, ovulation and peri-ovulatory hormone profiles in tethered and loose-housed sows

Multiparous sows that had been tethered during lactation were put in two different housing conditions after weaning (Day 0); the sows were either tethered by neck chain, or individually housed in a pen of approximately 6 m2. After two months, ten tethered and eleven loose housed sows were used to assess stress and reproductive parameters. Stereotypic behaviour after the afternoon feeding was assessed from Day 18 onwards; at Day 53 stereotypic behaviour tended to occur during a higher percentage of time in the tethered sows (P = 0.11) and at Day 66, the differences were significant (tethered, 78 +/- 5 vs. loose-housed, 40 +/- 10% of time (mean +/- sem); P = 0.03). At Day 35 and 55, cortisol profiles after afternoon feeding were similar for the two groups of sows (P > 0.10). Around oestrus (approximately Day 64), the profiles of oestradiol-17 beta, luteinizing hormone and progesterone were measured and proved to be similar for both treatment groups (P > 0.10). The duration of oestrus was shorter in the tethered sows (42 +/- 4 vs. 63 +/- 2 h; P < 0.001) and, consequently, the timing of ovulation during oestrus (h after onset of oestrus) was advanced in the tethered sows (28 +/- 2 vs. 41 +/- 2; P < 0.001). The duration of ovulation did not differ (tethered, 2.9 +/- 0.5 vs. loose-housed, 2.1 +/- 0.2 h; P = 0.16). The sows were sacrificed at Day 5 after ovulation; ovulation rate, fertilization rate, embryo development and embryo diversity were similar for the two groups, as were adrenal weight and size of adrenal cortex. Duration of oestrus and the levels of stereotypies at Day 60 tended to be negatively related in the tethered sows (P = 0.07), but not in the loose-housed sows (P = 0.65). In conclusion, sows that had been tethered during pregnancy and lactation, and were housed loose or were tethered again at weaning within two months differed both in stereotypic behaviour and in duration of oestrus, without apparent effects on reproductive hormones.     

Alteration of laminin production in small-cell lung carcinoma: possible correlation with the absence of the basement membrane

The amount of protein recommended to minimise N loss in critically ill patients receiving total parenteral nutrition (TPN) varies in the literature. Therefore, we studied the effect of increased protein intake on the N balance, administering TPN with either 1.2 g protein/kg/day (low N diet) or 1.8 g protein/kg/day (high N diet). Fifteen mechanically ventilated critically ill patients were studied in a surgical intensive care unit. After at least two days of standard TPN, patients were randomly assigned to either the low or the high N diet. Ten patients were studied on the low N diet and 11 on the high N diet; 6 patients were studied on both diets. Nonprotein energy was supplied according to estimated energy requirements. For five consecutive days, the N balance was measured daily. Total urinary nitrogen (TUN) was analysed using the Kjeldahl method. There was no difference in N balance between the groups. On the low N diet, N balance was -0.113 +/- 0.088 and on the high N diet -0.113 +/- 0.109 g N/kg/day. In patients studied twice, N balance was -0.087 +/- 0.054 and -0.050 +/- 0.060 g N/kd/day respectively. Results of a previous pilot study showed that in 20 similar patients the N balance became 80% less negative (from -5.7 +/- 5.1 to -1.1 +/- 8.2 g N/day) when protein intake was increased from 0.9 to 1.5 g/kg/day. Since these results are consistent with other studies, we conclude that the optimal range of protein supply in this type of critically ill patients is approximately 1.1-1.5 g protein/kg/day.     

Effect of 48 h treatment with 17 beta-oestradiol or progesterone on follicular wave emergence and synchrony of ovulation in Bos indicus cows when administered at the end of a period of progesterone treatment

The objective of this study was to determine the effect of treatment with additional progesterone (P4) or 17 beta-oestradiol (E2) at the end of a period of P4 treatment on ovarian follicular development, ovulation time, and plasma gonadotrophin and steroid hormone concentrations of Bos indicus cows. Initially, two injections of PGF2 alpha were given 14 days apart, and at the time of the second injection (Day 0) all cows received a single P4-releasing controlled internal drug release (CIDR) device that was removed 10 days later. Control cows (Group 1, n = 8) received no other treatment. On Day 8, cows in Group 2 (n = 8) and Group 3 (n = 8) received either a s.c. implant containing E2, or a second CIDR device, respectively. All CIDR devices and E2 implants were removed at a similar time on Day 10. Treatment with E2 or P4 delayed mean (+/- SD) time of ovulation (113.1 +/- 25.6 h, 153.4 +/- 44.5 h and 150.8 +/- 25.1 h for Groups 1, 2 and 3, respectively; P < 0.05) and the mean time (+/- SD) of the luteinising hormone (LH) peak (87.4 +/- 24.5 h, 124.3 +/- 45.0 h and 122.3 +/- 25.04 h for Groups 1, 2 and 3, respectively; P < 0.05). Both treatments delayed the mean (+/- SD) day of emergence of the ovulatory follicle (7.7 +/- 3.6 days, 11.3 +/- 1.7 days and 11.1 +/- 1.5 days for Groups 1, 2 and 3, respectively; P < 0.05), and reduced the variability in the day of emergence of the ovulatory follicle (P < 0.05) compared with the control cows. Variability in age and duration of dominance of the ovulatory follicle was greater in control animals compared with treated animals (P < 0.05). Treatment with E2 on Days 9 and 10 did not alter mean concentrations of gonadotrophins in the cows in Group 2 compared with control cows (P > 0.05), whereas treatment of cows with an additional CIDR device resulted in greater mean concentrations of FSH and lesser concentrations of LH on Day 9 (P < 0.05) compared with cows in Groups 1 and 2. By Day 10 mean concentrations of gonadotrophins were similar among cows in all three groups. Concentrations of E2 were less in cows in Group 3 compared with cows in Groups 1 and 2 from Day 9 to Day 11 (P < 0.05). We conclude that treatment with either E2 or P4 can influence the pattern of ovarian follicular development and ovulation in cattle; however, the mechanism of action of the two treatments may differ. Atretogenic treatments for ovarian follicles applied at the end of a period of progesterone treatment did not improve synchrony of ovulation.     

Temporary impairment of lung function in infants with anterior abdominal wall defects who have undergone surgery

Compliance of the respiratory system (CRS) was measured before and after surgical intervention in 14 infants who had anterior abdominal wall defects (AWD) (7 exomphalos, 7 gastroschisis). The median gestational age was 37 weeks (range, 34 to 40) and median birth weight was 2.38 kg (range, 1.94 to 3.45). The infants had stiff lungs before surgery (median CRS, 0.58 mL/cm H2(O)/kg). During the first and second postoperative days, the median CRS decreased to 0.33 mL/cm H2(O)/kg (P < .05). In seven cases, measurements also were obtained on the third and fourth postoperative days, which showed an increase in the median CRS (day 3, 0.47 mL/cm H2(O)/kg; P < .05). These findings show that in infants with AWD, primary surgical closure is associated with deterioration of lung function, but this effect is temporary.     

Variations in Valsalva leak point pressure with increasing vesical volume

PURPOSE: Although leak point pressure testing is a valuable tool in the diagnosis of female stress urinary incontinence, little standardization in methodology exists. We examined the effect of vesical volume on leak point pressure to assess the need for determining an optimal volume for leak point pressure testing. MATERIALS AND METHODS: Video urodynamic testing was performed in 52 consecutive women with a mean age of 52 years who presented with stress urinary incontinence. By fluoroscopic criteria stress urinary incontinence was type I in 12 patients, type II in 20 and type III in 20. Leak point pressure determined at 50 cc volume increments was correlated with fluoroscopic criteria. RESULTS: Women with type I stress urinary incontinence had high leak point pressure, which remained high at increasing vesical volumes, and those with type III had low leak point pressure, which remained low at increasing volumes. In patients with type II incontinence initially high leak point pressure decreased significantly at increasing vesical volumes. The most appropriate classification of patients occurred at a volume of 250 to 300 cc. CONCLUSIONS: Leak point pressure is affected by vesical volume. At a volume of 250 to 300 cc leak point pressure correlates best with fluoroscopic findings, and it may be used to guide therapy in women presenting with stress urinary incontinence.     

Miniaturization of analytical systems

BACKGROUND: Bleomycin produces lung fibrosis in a wide variety of species. In humans, it can cause significant morbidity and mortality when used to treat malignancies such as lymphoma and testicular carcinoma. In rodents, it has been extensively used to study key mechanisms of lung injury and repair. Bleomycin pulmonary toxicity is mediated, at least in part, by the generation of active oxygen species. Amifostine, an aminothiol compound, is a cytoprotectant that is used with many antitumor agents and can act as a potent scavenger of free radicals. The authors hypothesized that amifostine could ameliorate bleomycin lung injury. METHODS: Hamsters weighing 120 g were given an intraperitoneal (IP) injection of amifostine (200 mg/kg, 1180 mg/m2) or saline with intratracheal (IT) bleomycin (1 unit) or saline, followed by daily IP amifostine or saline for 6 days. Lungs were assessed on Day 2 for acute lung injury, which was determined by wet-to-dry lung weight ratios. On Day 21, histologic assessment of fibrosis and biochemical analysis of lung hydroxyproline content were performed. RESULTS: No significant differences in morbidity or mortality were observed among the groups. Animals who received IT bleomycin, when compared with controls, had increased lung water measurements on Day 2 that were consistent with acute inflammation; on Day 21, they had pulmonary fibrosis, as measured by morphometric analysis, as well as increased hydroxyproline content. For animals treated with amifostine and bleomycin, significant decreases in wet-to-dry lung weight ratios were observed (mean +/- standard deviation, 4.5+/-1.2 vs. 10.2+/-2.7), as well as significant decreases in the percentage of fibrosis per lung (15.03%+/-3.27 vs. 37.26%+/-5.76) and hydroxyproline content (1.132+/-0.30 vs. 1.831+/-0.243). CONCLUSIONS: Amifostine significantly decreased the amount of acute lung injury and subsequent fibrosis in the hamster model of bleomycin-induced lung injury.     

Ventricular pressure slope and bileaflet mechanical heart valve closure

The maximum left ventricular pressure slope (dP/dt) value has been used by several investigators as the criterion for studying mitral valve closure. In this article, the relationship between the ventricular pressure slope (dP/dt) and the leaflet closing behavior of bileaflet mechanical heart valves (BMV) is investigated. Two current BMVs, the St. Jude Medical 29 mm and CarboMedics 29 mm, installed in the mitral position of a mock circulatory pulsatile flow loop were used as the study model. Under simulated physiologic pressures and flow conditions, the experiment was conducted at 70, 90, and 120 beats/min with corresponding flow rates of 5.0, 6.0, and 7.5 liters/min, respectively. A laser sweeping technique was used to monitor the leaflet closing motion within the last 3 degrees excursion at valve closure. A modified dual beam laser sweeping technique system was used to register the difference of leaflet/housing impact time between the two BMV closing leaflets in asynchronous closure. Common BMV asynchronous closures were found in both BMVs at all three heart rates tested. The second closing leaflet was found to always close at higher velocity than the first. Simultaneous measurements of the ventricular pressure (Pv) and the leaflet closing time showed that Pv exhibited three stage characteristics. In the first stage, Pv gradually increased as the ventricle was filled. A sudden rise of Pv occurred immediately after closing of the first leaflet. The maximum dp/dt occurred in the third stage after closure of both BMV leaflets. The BMV closing behavior and the corresponding Pv pattern were found to depend strongly upon valve type and heart rate. The time averaged ventricular pressure slope (dp/dt) values at 70, 90, and 120 beats/min were about 40, 70, and 150 mmHg/sec for the St. Jude Medical valve and 40, 105, and 205 for the CarboMedics valve during the first closing stage. The maximum dp/dt values were 2670, 4350, and 5000 mmHg/sec for the St. Jude Medical valve and 1210, 2530, and 3210 mmHg/sec for the CarboMedics valve at the three heart rates tested, respectively. The study showed that the left ventricular pressure patterns (dP/dt) at valve closure were the result of valve operation under given driving conditions. The dp/dtmax cannot be used as the criterion for studying BMV closure.     

Urinary glycosaminoglycan excretion in healthy and stone-forming children

OBJECTIVE: To investigate whether the physiological response to surgery-induced stress, as measured by changes in serum secretory proteins, is more profound on older than in younger total joint arthroplasty patients. DESIGN: Retrospective study. SETTING: A 267-bed teaching hospital. PARTICIPANTS: A total of 220 ambulatory patients with normal admission serum albumin levels, of whom 106 were 65 years of age or older (mean age 73.3 +/- 6.2 years) and 114 less than age 65 (mean age 48.8 +/- 12.2 years). METHODS: Serum albumin and transferrin levels obtained at admission an on the fifth and tenth postoperative days were compared in the two age groups. RESULTS: In both age groups, admission serum albumins were significantly higher than on the corresponding postoperative Day 5 levels (40.4 +/- 3.7 g/L vs 25.0 +/- 3.3 g/L, P < .0001 and 39.5 +/- 2.5 g/L vs 23.9 +/- 3.1 g/L, P < .001 in older and younger patients, respectively). The drop in the serum concentration of albumin by postoperative Day 5 in the older patients was not significantly different from that of the younger patients (a drop of 15.6 +/- 3.3 g/L in older vs 15.4 +/- 4.4 g/L for the younger, P = .740). Among the 64 patients who remained in the hospital 10 days subsequent to surgery, the average postoperative Day 10 serum albumin concentration was significantly lower in the older patients when compared with the younger (26.2 vs 29.1 g/L P = .016). Similar results were obtained for serum transferrin. CONCLUSIONS: Subsequent to elective arthroplasty, the magnitude of change in serum albumin and transferrin concentrations is similar in older compared with younger, patients, suggesting that this stress response to surgery is nor age dependent. In contrast, the rate of recovery of the serum protein concentrations to preoperative levels may be slower in the older patients. However, this issue needs to be investigated further.     

The significance of citrate, uromucoid and GAG for diagnosis of renal tubular acidosis in patients with urinary calculi]

BACKGROUND: The purpose of this study was to determine the effects of early postoperative tube feeding on outcomes of liver transplant recipients. METHODS: Fifty transplant patients were randomized prospectively to receive enteral formula via nasointestinal feeding tubes (tube-feeding [TF] group) or maintenance i.v. fluid until oral diets were initiated (control group). Thirty-one patients completed the study. Resting energy expenditure, nitrogen balance, and grip strength were measured on days 2, 4, 7, and 12 after liver transplantation. Calorie and protein intakes were calculated for 12 days posttransplant. RESULTS: Tube feeding was tolerated in the TF group (n = 14). The TF patients had greater cumulative 12-day nutrient intakes (22,464 +/- 3554 kcal, 927 +/- 122 g protein) than did the control patients (15,474 +/- 5265 kcal, 637 +/- 248 g protein) (p < .002). Nitrogen balance was better in the TF group on posttransplant day 4 than in the control group (p < .03). There was a rise in the overall mean resting energy expenditure in the first two posttransplant weeks from 1487 +/- 338 to 1990 +/- 367 kcal (p = .0002). Viral infections occurred in 17.7% of control patients compared with 0% of TF patients (p = .05). Although other infections tended to occur more frequently in the control group vs the TF group (bacterial, 29.4% vs 14.3%; overall infections, 47.1% vs 21.4%), these differences were not statistically significant. Early posttransplant tube feeding did not influence hospitalization costs, hours on the ventilator, lengths of stay in the intensive care unit and hospital, rehospitalizations, or rejection during the first 21 posttransplant days. CONCLUSIONS: Early posttransplant tube feeding was tolerated and promoted improvements in some outcomes and should be considered for all liver transplant patients.     

What is a migraine, anyway, and when is it gone?

PURPOSE: To assess the effect of pneumoperitoneum on P(a-ET)CO2 gradient in children. METHODS: Sixty one ASA I and II children (10.7 +/- 3.0 yr, 38.4 +/- 14.2 kg, mean +/- SD), scheduled for visceral or urological laparoscopic procedures, were studied. They were anaesthetized, intubated, paralysed and their lungs ventilated with constant ventilator settings to obtain PETCO2 values between 4.3 and 4.8 kPa. Intra-abdominal pressure was maintained between 8 and 14 mmHg. The following measurements were performed at steady state, before the pneumoperitoneum (T1) and 15 min later (T2): heart rate, systolic and diastolic arterial pressure; peak airway and intra-abdominal pressure; PaCO2 corrected for the patient's temperature; PETCO2 drawn between the micropore filter and the ventilator tubes, corrected for BTPS conditions; P(a-ET)CO2. Values between -1.0 and +1.0 mmHg were considered nil; patient position (horizontal or head-down tilt): all patients were horizontal at T1. RESULTS: Arterial pressure, heart rate and peak airway pressure increased at T2: PaCO2 and PETCO2 increased by 14%. The incidence of negative gradients increased from 54 to 67% although mean P(a-ET)CO2 remained clinically unchanged. No difference was found in P(a-ET)CO2 gradient, whatever the position and intra-abdominal pressure. The 95% confidence intervals for P(a-ET)CO2 were [-5.6; +3.2] at T1 and [-8.8; +4.8] at T2. CONCLUSION: PETCO2 often overestimates PaCO2 during laparoscopy in children, by up to 8.8 mmHg. Arterial blood gas analysis should be performed during long procedures to avoid hyperventilation.     

Semiquantitative reverse transcription-polymerase chain reaction analysis of mRNA for growth factors and growth factor receptors from normal and healing rabbit medial collateral ligament tissue

By studying western lowland gorillas (Gorilla gorilla gorilla, n = 8) in zoological gardens via ethological and non-invasive physiological techniques, we have demonstrated that their postpartum maternal behavior is related negatively to their postpartum urinary titers of cortisol. On the basis of this finding, it is proposed that postpartum stress contributes to disrupted maternal behavior in the gorilla in captivity. Morning urine samples were collected with a mean sampling interval of 1.6 days from Day 14 prepartum to Day 14 postpartum (n = 11 pregnancies). Creatinine-indexed (Cr) urinary cortisol titers declined significantly between Day 9 to 1 prepartum (0.634 +/- 0.014 microg/mg of Cr, mean +/- SEM) and Day 1 to 6 postpartum (0.396 +/- 0.030 microg/mg of Cr, mean +/- SEM; p < 0.01-0.001). For each pregnancy, the relative postpartum decline in urinary cortisol was calculated as (microg of cortisol/mg of Cr Day 1 to 4)/(microg of cortisol/mg of Cr Day -4 to -1). Values ranged from 0.35 to 1.12, were independent of absolute prepartum cortisol titers, and were interpreted as evidence of inter-female differences in postpartum hypothalamo-pituitary-adrenal axis activity and, therefore, postpartum stress. This postpartum stress index was negatively correlated with the amount of time (0-100%) that females carried and supported their 0-14 day-old infants in a ventral position during locomotion (r(s) = -0.68, p < 0.05) and tended to be negatively correlated with the total amount of time (0-100%) they spent in ventro-ventral contact with their infants (r(s) = -0.58; p < 0.10). This study provides the first physiological evidence that postpartum stress is an important etiologic factor in gorilla maternal failure in captive environments.     

Urinary kallikrein: a marker of blood pressure sensitivity to salt

We evaluated if a rat strain inbred for low urinary kallikrein excretion differs from normal-kallikrein Wistar rats regarding blood pressure levels in basal conditions and during alterations in sodium balance. Blood pressure was measured in unanesthetized rats on normal sodium intake. Then, blood pressure sensitivity to salt was evaluated over a period of 20 days of high sodium diet (0.84 mmol per g chow). Low-kallikrein rats showed greater systolic blood pressure levels (125 +/- 3 vs. 114 +/- 2 mm Hg in controls, P < 0.01) at nine weeks of age. Systolic blood pressure was increased after sodium loading in the low-kallikrein group and remained unchanged in controls (150 +/- 6 vs. 112 +/- 2 mm Hg, P < 0.01). This effect was associated with a reduced cumulative urinary excretion of sodium in the low-kallikrein rats. No group difference was found in the clearance of endogenous creatinine in basal conditions. Urinary creatinine excretion decreased during sodium loading, particularly in the low-kallikrein group. The group-difference in urinary kallikrein excretion found in basal conditions (6.85 +/- 0.31 vs. 20.74 +/- 1.71 nkat/24 hr in controls, P < 0.01) was enhanced by high salt diet (2.96 +/- 0.67 vs. 22.07 +/- 2.47 nkat/24 hr in controls, P < 0.01). In addition, renal kallikrein activity and content were reduced in low-kallikrein rats. The latter group showed a greater ratio of heart weight to body wt both in basal conditions and after sodium loading. The ratio of kidney weight to body wt was reduced after sodium loading. These results indicate that a genetically-determined defect in urinary kallikrein excretion is associated with a greater blood pressure sensitivity to salt, possibly due to altered renal sodium handling.     

Polymorphisms in the HFE gene

BACKGROUND: An important function of the gallbladder is to acidify and concentrate bile. Acidification helps protect against the precipitation of calcium salts, which promote gallstone formation. Altered acidification may result in pigment gallstones. We investigated gallbladder composition in a model of TPN-associated pigment gallstones to test whether changes in acidification may be important in this gallstone model. MATERIALS AND METHODS: Ten miniswine were intravenously fed for 21 to 27 days (mean 23 days). Ten fed pig chow with intravenous infusion of saline served as controls. Gallbladder and hepatic bile electrolytes, lipids, pH, and pCO2 were measured. RESULTS: All animals remained healthy and gained weight. Hepatic bile electrolytes and pH were similar among all animals. Pigs on TPN had a higher gallbladder pH and the [H+] was half the value of controls [8.1 +/- 1.6 x 10(-8) meq/liter (control) versus 3.9 +/- 0.7 x 10(-8) meq/liter (TPN)]. Gallbladder bile pCO2, sodium (Na), and potassium were higher in controls. Biliary lipids [bile salts (BS), phospholipids, and cholesterol] with TPN were decreased in both hepatic and gallbladder bile. CONCLUSIONS: Unlike short-term TPN where gallbladder pH and [BS] are similar, with long-term TPN pH is higher with lower [H+], [Na], and [BS]. Despite a presumed longer residence time in the gallbladder, intravenous feeding without oral intake results in gallbladder bile that is less concentrated and acidified. Enteral stimulation may be an important stimulus for gallbladder acidification and periods without feeding may promote gallstone formation by increasing the pH of gallbladder bile.     

Effect of methionine-deprived total parenteral nutrition on tumor protein turnover in rats

BACKGROUND: Previous studies have shown that a methionine-lacking diet inhibited tumor growth in rats. The aim of this study was to determine how methionine free total parenteral nutrition (MTPN) can result in the inhibition of tumor growth on tumor protein metabolism in rats. METHODS: On day 0, AH109A rat ascites hepatoma cells were implanted subcutaneously into male Donryu rats (n = 68, body weight, 200-225 gm). On day 10, a catheter for total parenteral nutrition (TPN) was placed and either MTPN or standard TPN solution was given for 5 days. On day 15, 1-14C-leucine was infused continuously to measure tumor protein synthesis. Tumor proteolysis was calculated from tumor regional blood flow, using the 85Sr-microsphere injection method. RESULTS: 1) Tumor weight was reduced with MTPN. 2) MTPN did not affect tumor protein synthesis, probably because endogenous methionine production was increased with MTPN (87.3 +/- 13.5 mumole methionine/kg/hour vs. 218.6 +/- 29.5, P < 0.01); however, MTPN caused an increase of tumor proteolysis (2.68 +/- 0.53 mumole leucine/g/hour vs. 3.79 +/- 0.73, P < 0.05). CONCLUSION: The enhanced tumor protein breakdown contributed to the inhibition of tumor growth that was found with the rats given the methionine free diet.     

Hemodynamic and renal excretory effects of human brain natriuretic peptide infusion in patients with congestive heart failure. A double-blind, placebo-controlled, randomized crossover trial

BACKGROUND: The pharmacological effects of infusion of human brain natriuretic peptide (hBNP) in patients with severe congestive heart failure have not been characterized previously. METHODS AND RESULTS: Twenty patients with severe congestive heart failure were randomized in a double-blind, placebo-controlled, crossover trial to receive incremental 90-minute infusions of hBNP (0.003, 0.01, 0.03, and 0.1 microgram/kg per minute) or placebo on 2 consecutive days. At the highest completed dose of the hBNP, mean pulmonary artery pressure decreased from 38.3 +/- 1.6 to 25.9 +/- 1.7 mm Hg; mean pulmonary capillary wedge pressure decreased from 25.1 +/- 1.1 to 13.2 +/- 1.3 mm Hg; mean right atrial pressure decreased from 10.9 +/- 1 to 4.8 +/- 1.0 mm Hg; mean arterial pressure decreased from 85.2 +/- 2.0 to 74.9 +/- 1.7 mm Hg; and cardiac index increased from 2.0 +/- 0.1 to 2.5 +/- 0.1 L/min per square meter (all P < .01 versus placebo). Urine volume and urine sodium excretion increased significantly during hBNP infusion when compared with placebo infusion (90 +/- 38 versus 67 +/- 27 mL/h and 2.6 +/- 2.4 versus 1.4 +/- 1.2 mEq/h, respectively, both P < .05 versus placebo), whereas creatinine clearance and urinary potassium excretion did not change. CONCLUSIONS: Infusion of incremental doses of hBNP is associated with favorable hemodynamic and natriuretic effects in patients with severe congestive heart failure.     

Lhermitte-Duclos disease: first report in Taiwan

Nutritional support is important in critically ill patients, with variable energy and nitrogen requirements (e.g., sepsis, trauma, postsurgical state) in this population. This study investigates how age, severity of illness, and mechanical ventilation are related to resting energy expenditure (REE) and nitrogen balance. Nineteen critically ill children (mean age, 8 +/- 6 [SD] y and range 0.4-17.0 y) receiving total parenteral nutrition (TPN) were enrolled. We used indirect calorimetry to measure REE. Expected energy requirements (EER) were obtained from Talbot tables. Pediatric Risk of Mortality (PRISM) and Therapeutic Intervention Scoring System (TISS) score were calculated. Total urinary nitrogen was measured using the Kjeldahl method. PRISM and TISS scores were 9 +/- 5 and 31 +/- 6 points, respectively. REE was 62 +/- 25 kcal.kg-1.d-1, EER was 42 +/- 11 kcal.kg-1. d-1, and caloric intake was 49 +/- 22 kcal.kg-1.d-1. Nitrogen intake was 279 +/- 125 mg.kg-1.d-1, total urinary nitrogen was 324 +/- 133 mg.kg-1.d-1, and nitrogen balance was -120 +/- 153 mg.kg-1.d-1. The protein requirement in this population was approximately 2.8 g.kg-1.d-1. These critically ill children were hypermetabolic, with REE 48% higher (20 kcal.kg-1.d-1) than expected. Nitrogen balance significantly correlated with caloric and protein intake, urinary nitrogen, and age, but not with severity of illness scores or ventilatory parameters.     

The molecular specificity of action of the tetrapeptide acetyl-N-Ser-Asp-Lys-Pro (AcSDKP) in the control of hematopoietic stem cell proliferation

Nutritional effects have traditionally focused on outcomes, such as nitrogen balance, wound healing, or muscle strength. Little emphasis has been placed on how biochemical or physical improvements translate into functional changes as perceived by the patient. Because glutamine (GLN)-supplemented nutrition promotes protein synthesis and improves nitrogen balance, we assessed the mood of individuals participating in a randomized controlled blinded trial receiving GLN solutions. Patients (n = 23) undergoing marrow transplantation were randomized by the research pharmacist to receive either standard total parenteral nutrition (TPN) (control) or GLN-containing TPN (40 g of glutamine total). The solutions were isocaloric and isonitrogenous and were administered until the patient was eating 50% of estimated requirements. Before TPN and on admission to the hospital, the patient completed the Profile of Mood States questionnaire, a standardized test quantifying the degree of tension, depression, anger, vigor, fatigue, and confusion. The patient completed the questionnaire again at the end of TPN near discharge. The tests were scored and the change from baseline for each mood for both groups of patients was calculated at the completion of TPN. The scores for vigor in the control group (delta scores) decreased over the course of hospitalization as would be expected with a serious illness. The group receiving glutamine TPN, however, essentially showed little change in vigor from baseline and the delta score was significantly different from the control group (delta vigor score -0.85 +/- 2.1 in the glutamine group vs. -5.90 +/- 1.7 in the control group; p = .07).(ABSTRACT TRUNCATED AT 250 WORDS)     

Increase in extracellular glutamate caused by reduced cerebral perfusion pressure and seizures after human traumatic brain injury: a microdialysis study

OBJECT: To determine the extent and duration of change in extracellular glutamate levels after human traumatic brain injury (TBI), 17 severely brain injured adults underwent implantation of a cerebral microdialysis probe and systematic sampling was conducted for 1 to 9 days postinjury. METHODS: A total of 772 hourly microdialysis samples were obtained in 17 patients (median Glasgow Coma Scale score 5+/-2.5, mean age 39.4+/-20.4 years). The mean (+/-standard deviation) glutamate levels in the dialysate were evaluated for 9 days, during which the mean peak concentration reached 25.4+/-13.7 microM on postinjury Day 3. In each patient transient elevations in glutamate were seen each day. However, these elevations were most commonly seen on Day 3. In all patients there was a mean of 4.5+/-2.5 transient elevations in glutamate lasting a mean duration of 4.4+/-4.9 hours. These increases were seen in conjunction with seizure activity. However, in many seizure-free patients the increase in extracellular glutamate occurred when cerebral perfusion pressure was less than 70 mm Hg (p < 0.001). Given the potential injury-induced uncoupling of cerebral blood flow and metabolism after TBI, these increases in extracellular glutamate may reflect a degree of enhanced cellular crisis, which in severe head injury in humans appears to last up to 9 days. CONCLUSIONS: Extracellular neurochemical measurements of excitatory amino acids may provide a marker for secondary insults that can compound human TBI.     

Differences in airway closure between normal and asthmatic subjects measured with single-photon emission computed tomography and technegas

The absence of a maximal dose-response plateau as well as gas trapping and increases in closing capacity (CC) suggest that increased airway closure is an important mechanical abnormality of asthmatic airways. We compared the extent and distribution of airway closure in 13 normal and in 23 asthmatic subjects. Airway closure (LVclosed) was measured with single-photon emission computed tomography (SPECT) and an inhaled Technegas bolus as the percentage of lung volume without Technegas (LVtrans), and with CC, using nitrogen washout. LVclosed was compared in the apical, middle and lower zones, each being of equal vertical height. Values of mean LVclosed +/- 95% confidence interval (CI) were similar in normal (30 +/- 6.0% LVtrans) and asthmatic subjects (30 +/- 7.8% LVtrans). In normal subjects, LVclosed correlated with both age (r = 0.89, p < 0. 01) and CC (r = 0.86, p < 0.01), was more extensive in the lower zone (58 +/- 18.8% LVtrans, p < 0.01) than in the middle and upper zones (17 +/- 8.7% and 26 +/- 8.2 LVtrans, respectively), and increased with age in both the middle and lower zones (r = 0.94 and r = 0.90, respectively, p < 0.01). In asthmatic subjects, LVclosed did not correlate with age; was greatest in the lower zone, intermediate in the middle zone, and lowest in the apical zone (59 +/- 13.2%, 22 +/- 5.8%, and 12 +/- 4.4% LVtrans, respectively, p < 0. 01); and correlated weakly with age in the middle zone only (r = 0. 46, p < 0.05). We conclude that there is a predictable pattern of airway closure in normal subjects and that it is primarily influenced by pulmonary elastic recoil. This pattern is lost in asthmatic subjects. This may be explained by an increased range of closing pressures and a patchy distribution of airway closure, probably secondary to allergic inflammation.