Galanin in the hypothalamus of fed and fasted lean and obese Zucker rats

Galanin (GAL), a 29 aminoacid peptide, is widely distributed in the central nervous system and especially in the hypothalamus. It strongly stimulates food intake when it is injected in the paraventricular nucleus (PVN) of normal rats. The obese Zucker rat with a well-established hyperphagia is characterized by a general dysregulation of some important neuropeptides involved in the regulation of feeding behavior e.g. neurotensin, NPY or CCK and the aim of this study was to measure GAL in different microdissected brain areas in lean (Fa/Fa) and obese (fa/fa) male Zucker rats. As feeding status may modulate the central peptide concentrations, it was measured in ad libitum fed rats and in 48-h fasted rats of both genotypes. GAL was measured by a specific radioimmunoassay in the arcuate nuclei (ARC) and parvocellular (PVNp) and magnocellular (PVNm) parts of the PVN as well as in the median eminence (ME), median preoptic area (MPOA), supraoptic (SON) and dorsomedian (DMN) nuclei. Two-way analysis of variance revealed a very significant effect of genotype in the PVNp (P < 0.001), SON (P < 0.001) and in the ME (P < 0.02). No significant variations at all were noted in the ARC, PVNm, MPOA and DMN. GAL concentrations were more than doubled in the PVNp and SON of ad lib obese rats when compared to the ad lib lean rats (P < 0.005). On the other hand, in the ME where GAL concentration was about 4-fold greater than in the other areas, there was a 20 to 30% decrease in GAL concentrations in the obese rat (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Stimulation by leptin of 3H GDP binding to brown adipose tissue of fasted but not fed rats

We conducted a retrospective review of 125 patients undergoing high-dose therapy and stem cell rescue in order to evaluate the incidence of documented infection and the utility of the administration of vancomycin empirically. All patients received prophylactic oral quinolone therapy. Because neutropenia in this setting is relatively brief, 21 patients never manifested fever, and no patient died of infection. Of the remaining 104 patients, positive blood cultures were obtained in only 10, nine with a gram stain positive and one with a gram stain negative organism. Sixty-two patients without any evidence of gram positive infection received vancomycin according to the existing algorithm for care of neutropenic fevers. In this population of patients, empiric administration of vancomycin for neutropenic fevers without culture documentation appears to be unnecessary, could be discontinued safely and at substantial cost savings, and might slow the appearance of vancomycin-resistant organisms.     

Nephrectomy decreases amylin and pramlintide clearance in rats

Amylin is a 37 amino acid hormone, co-secreted with insulin from the pancreatic beta-cell in response to nutrient stimuli. Because the human amylin analog, pramlintide, is being tested in patients with diabetes mellitus, a known risk factor for nephropathy, we examined the role of the kidney on amylin and pramlintide metabolism and action in functionally nephrectomized rats. Nephrectomy markedly altered amylin metabolism: it increased incremental area under the plasma amylin concentration curve 3.6-fold (P<0.001) and increased the elimination half-life from 17+/-1 to 26+/-2 minutes (P < 0.01) after subcutaneous injection of 100 microg amylin. Nephrectomy decreased plasma amylin clearance from 20.3+/-1.1 to 7.9+/-0.4 mL/min (P < 0.0001). Thus, at these doses in the rat, the kidney is important for metabolizing amylin and pramlintide.     

Activin B: detection by an immunoenzymometric assay in human serum during ovarian stimulation and late pregnancy

Cerebral 1H MR spectra were recorded in 13 children and adolescents with schizophrenia and 12 healthy children and adolescents. Stimulated echo acquisition mode (STEAM) sequence was used to localize an 8-ml voxel bilaterally in the frontal gray matter. The frontal gray matter metabolite ratios for NAA/Cr, Ch/Cr, Glx/Cr, and mI/Cr in schizophrenic children and adolescents were 1.08 +/- .28, .64 +/- .23, 1.09 +/- .30, and .60 +/- .24, respectively. In comparison, these ratios were 1.59 +/- .35, .74 +/- .27, 1.23 +/- .36, and .58 +/- .29 in healthy children and adolescents. Decrease in the frontal lobe NAA/Cr of schizophrenic children and adolescents was statistically significant (P < .001). In contrast, the MR spectra localized bilaterally in the occipital gray matter (8 ml) showed no significant changes between the patients and the controls. In the occipital gray matter, the metabolite ratios were 1.21 +/- .26,.52 +/- .08, 1.00 +/- .11, and.55 +/- .12 inpatients versus 1.30 +/- .23, .45 +/- .10, 1.15 +/- .20, and .48 +/- .19 in controls. Our preliminary finding of reduced NAA/Cr ratio in the frontal gray matter is consistent with the neurodevelopmental models emphasizing dysfunction of frontal lobe areas in patients with schizophrenia.     

Plasma lipids, ketone bodies, and glucose concentrations in calves fed high- and low-fat milk replacers

Twenty-four 5-day-old male calves were fed twice daily milk replacers containing either 5% (low-fat) or 25% (high-fat) lard. Plasma lipids, blood glucose, and ketone bodies were determined in jugular blood before feeding and every hour during 8 h after feeding. The high-fat diet caused in the 1st h after feeding a sharp increase of triglycerides and phospholipids followed by a sharp decrease; these two increased slowly during the following 5 h. Within the first 2 h after feeding, there was an increase of cholesterol esters, free cholesterol, and nonesterified fatty acids. With the low-fat diet, triglycerides and cholesterol esters showed a small increase during the 4 h following meal whereas phospholipids, free cholesterol, and nonesterified fatty acids were not affected significantly. With both diets, blood glucose reached a maximum of 110 mg/100ml 1 h after feeding; ketone bodies were not altered significantly. With the high-fat diet, lipid digestion would occur in two phases; firstly, part of the fat would be lipolyzed quickly by pregastric esterase before clot formation in the abomasum; secondly, the rest of the lipids, slowly released by progressive lysis of the coagulum would be digested under the action of gastric and pancreatic lipases. The first phase did not occur with the low-fat diet.     

Plasma and erythrocyte alpha-tocopherol and plasma retinol concentrations in term infants fed formula enriched with long-chain polyunsaturated fatty acids

OBJECTIVE: To assess the effect of long-chain polyunsaturated fatty acids (LCPUFA)- and vitamin E-supplemented formula feeding on erythrocyte and plasma alpha-tocopherol (VE), and plasma retinol (VA) concentrations in neonates and to compare these values with those found in infants feeding on infant formula without LCPUFA or breast milk SETTING: University Hospital of Granada, Spain. SUBJECTS: 49 full-term infants. DESIGN AND INTERVENTION: Subjects who chose not to breast feed were fed either (i) unsupplemented infant formula (F) or (ii) infant formula supplemented with LCPUFA and vitamin E (FL). Alpha-tocopherol and retinol were measured at 7 days, 1 month and 3 months. RESULTS: Plasma and erythrocyte VE concentrations and plasma VE/total lipids ratio increased significantly in all groups at 1 month of life (P < 0.05), but did not change significantly between 1 month and 3 months in any group (P > 0.05). Erythrocyte VE and VA retinol concentrations were higher in infants fed an infant formula than in breast milk-fed infants at 1 month of life (P < 0.05). Finally, there were no significant differences in plasma or erythrocyte VE levels, plasma VA or plasma VE/total lipid ratio between any groups at 3 months of life (P > 0.05). CONCLUSION: Infants fed on LCPUFA- and vitamin E-supplemented infant formula for 3 months have similar vitamin E and A status to infants fed on breast milk or infant formula without LCPUFA supplementation.     

Effects of spinach leaf protein concentrate on the serum cholesterol and amino acid concentrations in rats fed a cholesterol-free diet

The effects of spinach leaf protein concentrate (SPPC) on serum and liver lipid concentrations and on serum free amino acid concentrations were examined in rats fed a cholesterol-free diet containing 2 and 10% fats. The serum total cholesterol, triacylglycerol and phospholipid concentrations in the rats fed an SPPC diet containing 2% corn oil were significantly lower than those of the rats fed a corresponding casein diet. When 10% corn oil or lard was used, the serum cholesterol-lowering effect of the SPPC became insignificant, but the serum and liver triacylglycerol concentrations were kept at significantly lower levels. Both the amounts of fecal neutral steroids and bile acids were significantly higher in the rats fed the SPPC than those of the casein-fed rats. The concentrations of serum threonine, serine, glutamine, glycine, cystine, and isoleucine were significantly higher in the rats fed the SPPC diet containing 2% corn oil compared with those of the control rats, but when the dietary fat was raised to 10%, only glycine showed a higher serum concentration. These results indicate that the SPPC has a stronger cholesterol-lowering effect at a lower dietary fat level, 2%, and the activity is partly due to the inhibition of intestinal absorption of cholesterol and bile acid, and partly due to an increase in the concentration of some of the serum amino acids.     

Plasma and blood vessel endothelin-1 concentrations in hypertensive uremic rats treated with erythropoietin

The present study was designed to evaluate whether changes in plasma and blood vessel endothelin-1 (ET-1) concentrations may play a role in the enhanced blood pressure response to recombinant human erythropoietin (r-HuEPO) replacement therapy in uremia. Renal failure was induced by 5/6 nephrectomy (Nx). Uremic rats received either r-HuEPO (100 u s.c. three times a week) or the vehicle for 5 weeks. They were compared to control rats receiving the vehicle. Systolic blood pressure (tail cuff method), hematocrit, serum creatinine, plasma and tissue ET-1 were measured at the end of the protocol. Immunoreactive ET-1 (ir-ET-1) was determined by radioimmunoassay of acid-extracts from the plasma, thoracic aorta and mesenteric arterial bed. Creatinine increased about three fold in Nx animals. Blood pressure in control rats was 120+/-3 mmHg compared to 161 +/-6 mmHg in the Nx + vehicle group (p <0.01) and 199+/-9 mmHg in the Nx + r-HuEPO group (p <0.01 vs Nx + vehicle). Hematocrit in control rats was 41.3+/-0.4% vs 32.6+/-1.8% in the Nx + vehicle group (p <0.01) and 47.6+/-1.5% in the Nx + r-HuEPO group (p <0.01). Plasma ir-ET-1 levels were similar in the Nx + vehicle and Nx + r-HuEPO groups (7.9+/-1.0 and 7.8+/-0.8 pg/ml). In contrast, thoracic aorta ir-ET-1 content was significantly higher in the Nx + r-HuEPO group than in the Nx + vehicle group (20.3+/-2.9 vs 13.4+/-1.9 pg, p <0.05). Similar results were obtained in the mesenteric arterial bed. There were significant correlations between blood pressure and ir-ET-1 content in the thoracic aorta (r= 0.45, p<0.05) and in the mesenteric arterial bed (r= 0.41, p<0.05). Vascular ET-1 content but not plasma levels are increased in uremic rats treated with r-HuEPO suggesting an increase in blood vessel ET-1 production which may play a role in the pathogenesis of r-HuEPO-induced hypertension.     

A spectrophotometric assay of folic acid concentrations in rats: correlations with age and organ

Spectrophotometric assays have been used to determine FA concentration in tissue homogenates from various organs (liver, kidneys, brain, spleen) in white rats; these studies were undertaken to test the age--and organ--dependent variations of FA concentrations in tissue homogenates. The results showed a marked decrease of FA concentration in the adult group of rats when related to the young group, and in the aged group when compared to the adults respectively. Analysing the determined values of folates in tissue homogenates of various organs (in rats belonging to the same group of age), the highest concentration has been found in the liver homogenate, followed in decreasing order by kidneys and to a much greater distance, by the brain and spleen.     

Plasma buspirone concentrations are greatly increased by erythromycin and itraconazole

BACKGROUND: The oral bioavailability of buspirone is very low as a result of extensive first-pass metabolism. Erythromycin and itraconazole are potent inhibitors of CYP3A4, and they increase plasma concentrations and effects of certain drugs, for example, oral midazolam and triazolam. The possible interactions of buspirone with erythromycin and itraconazole have not been studied before. METHODS: The pharmacokinetics and pharmacodynamics of buspirone were investigated in a randomized, double-blind, double-dummy crossover study with three phases. Eight young healthy volunteers took either 1.5 gm/day erythromycin, 200 mg/day itraconazole, or placebo orally for 4 days. On day 4, 10 mg buspirone was administered orally. Timed blood samples were collected up to 18 hours, and the effects of buspirone were measured with four psychomotor tests up to 8 hours. RESULTS: Erythromycin and itraconazole increased the mean area under the plasma concentration-time curve from time zero to infinity [AUC(0-infinity] of buspirone about sixfold (p < 0.05) and 19-fold (p < 0.01), respectively, compared with placebo. The mean peak plasma concentration (Cmax) of buspirone was increased about fivefold (p < 0.01) and 13-fold (p < 0.01) by erythromycin and itraconazole, respectively. These interactions were evident in each subject, although a striking interindividual variability in the extent of both interactions was observed. The elimination half-life of buspirone did not seem to be prolonged by either erythromycin or itraconazole. The effect of itraconazole on the Cmax and AUC(0-infinity) of buspirone was significantly (p < 0.01) greater than that of erythromycin. The greatly elevated plasma buspirone concentrations resulted in increased (p < 0.05) pharmacodynamic effects (as measured by the Digit Symbol Substitution test and the Critical Flicker Fusion test) and in side effects of buspirone. CONCLUSIONS: Both erythromycin and itraconazole greatly increased plasma buspirone concentrations, obviously by inhibiting its CYP3A4-mediated first-pass metabolism. These pharmacokinetic interactions were accompanied by impairment of psychomotor performance and side effects of buspirone. The dose of buspirone should be greatly reduced during concomitant treatment with erythromycin, itraconazole, or other potent inhibitors of CYP3A4.     

Diminished kidney function and nephrocalcinosis in rats fed a magnesium-deficient diet

Microcapsules have been used as drug delivery systems in the pharmaceutical field for sustained or controlled release of drug, and for artificial cells and organs. Biodegradable polymers, especially polylactic acid, have been widely used in this field. In this study, an attempt was made to develop a new method to prepare polylactic acid microcapsules for drug delivery. The biodegradable polylactic acid microcapsules were made by the phase separation process: two types of polylactic acid, poly[(D,L)lactic acid] and poly[(L)lactic acid] were combined as the membrane material. Because of the difference of the crystal properties of the two polymers, the aggregation which happens frequently in the phase separation process was prevented. As a model drug, Ciprofloxacin was encapsulated in the polylactic acid microcapsules.     

Pentagastrin stimulates epithelial cell proliferation in duodenal and colonic crypts in fasted rats

In fasted rats, single injection of pentagastrin (250 mug/kg) stimulates epithelial cell proliferation in the duodenum and colon, but not in the esophagus. Fasting for 64 hours suppresses cell proliferation more markedly in colonic crypts than in duodenal crypts, and pentagastrin restores the cell proliferative activity of the colon and duodenum to levels comparable with those of fed rats. In both duodenal and colonic crypts, differentiating-proliferative cells in the mid-portion of the crypts are more responsive to pentagastrin stimulation than immature proliferative cells at the base of the crypts. Non-dividing epithelial cells are not affected. Pentagastrin has no influence on cell proliferation in fed rats.     

Unidirectional influx of glutamine and other neutral amino acids into liver of fed and fasted rat in vivo

The fractional extraction of unidirectional influx of several neutral amino acids (glutamine, leucine, alanine, tryptophan, and cycloleucine) into rat liver in vivo is studied with a tissue-sampling, single-injection technique. Liver uptake of 14C-amino acid is expressed as an index relative to the hepatic clearance of a 3H-labeled water (3HOH) internal reference. The maximal fractional extraction of 3HOH influx into liver, 0.85, and the rate constant of 3HOH exodus back to blood, 0.87 min-1, provide an estimate of portal blood flow, 0.93 ml min-1 g-1, in the barbiturate-anesthetized, laparotomized rat. Given the extraction data for the 3HOH reference, liver uptake indices for the five amino acids studied are converted into maximal fractional extractions of amino acid influx into liver: glutamine, 0.72 +/- 0.03; leucine, 0.56 +/- 0.02; alanine, 0.43 +/- 0.04; tryptophan, 0.40 +/- 0.03; cycloleucine, 0.25 +/- 0.01; and sucrose, 0.09 +/- 0.02. The influx of glutamine and cycloleucine is shown to be increased (35%) with 48 h of fasting. These data indicate that glutamine penetrates the liver cell membrane faster than any of the 19 amino acids studied thus far. The rate of unidirectional influx of glutamine and other amino acids into liver is estimated and reveals that the capacity of liver cells to transport amino acids is severalfold greater than that of other organs such as brain or muscle.     

Detection of Vibrio anguillarum by a sandwich enzyme-linked immunosorbent assay performed with monoclonal antibodies

Monoclonal antibodies (Mabs) against V. anguillarum were produced and characterized by Western blotting analysis, competitive binding assays and cross-reactivity tests. Their ability to detect V. anguillarum in a liquid culture was tested in a sandwich enzyme-linked immunosorbent assay (ELISA) performed with different combinations of these Mabs used as capture or tracer antibodies. One combination was selected as the most suitable for diagnostic applications, showing the highest sensitivity and specificity.     

Plasma steroid concentrations in conscious and anesthetized rabbits

The ovarian steroids, estrogen, androgen, and progestin, were measured in the peripheral plasma of adult female rabbits that were either conscious or anesthetized with sodium pentobarbital (nembutal) or halothane. Concentrations of estrogen, androgens, and progestin were determined before and at 10 and 45 min after systemic injection of either buffer or LH. In the controls androgen levels were significantly different between animals anesthetized with nembutal and halothane. However, the greatest treatment effect was noted in plasma progestin concentrations which were significantly elevated in halothane-anesthetized animals in comparison to the conscious and nembutal-anesthetized animals. Following LH, the androgen and progestin levels were significantly elevated over basal levels. Most likely the treatment effect observed in the controls was still present but was overridden by the increased release of steroids following gonadotrophin stimulation. This study suggests that halothane, in contrast to nembutal, does significantly elevate peripheral progestin and androgen levels.     

Flavor preferences conditioned by intragastric nutrient infusions in rats fed chow or a cafeteria diet

Numerous studies demonstrate that chow-fed rats learn to prefer flavors that are associated with the postingestive effects of nutrients. The rats> limited dietary experience (i.e. only lab chow) may have facilitated preference learning because of the novelty of the training stimuli. This possibility was investigated by comparing nutrient conditioning in rats fed chow or a varied "cafeteria" diet. Rats in Experiment 1 were trained during alternate sessions (30 min/day) to drink two different flavors paired with concurrent intragastric infusions of 16% Polycose or water. Both diet groups displayed similarly strong preferences (89%) for and increased acceptance of the Polycose-paired flavor. A more demanding learning task was used in Experiment 2: new flavors were paired with delayed (15 min) infusions of Polycose or water. The chow and cafeteria groups both showed reduced, but comparable (78%, 77%) preferences for the Polycose-paired flavor. In Experiment 3, new flavors were paired with concurrent infusions of 7.1% corn oil or water. Again, the cafeteria and chow groups developed similar preferences for the nutrient-paired flavor (85%, 78%). Also, both groups preferred the Polycose-paired flavor of Experiment 1 to the oil-paired flavor of Experiment 3 (76%, 78%). These results indicate that dietary variety does not interfere with nutrient-conditioned flavor preference learning in rats.     

Glucagon, insulin, and gluconeogenesis in fasted odd carbon fatty acid-enriched rats

Forty-eight male rats were fed a nutritionally complete diet containing 30% of dietary energy as fat. For 24 animals (control) the fat source was corn oil, for the remaining 24 rats (experimental) the fat source was a triundecanoin-corn oil mixture (7:3, wt/wt). After 6 wk, groups of control and experimental rats were killed after 0, 24, and 48 h of fasting. In the experimental group, adipose tissue fatty acids contained, on average, 280 mmol undecanoate/mol fatty acid. In the control group, no odd-numbered fatty acids were present. During fasting, the experimental groups had higher plasma glucose and alanine levels, higher plasma insulin-to-glucagon ration, and lower liver phosphenol pyruvate caboxykinase. The results suggest that the terminal propionate residues generated when odd carbon fatty acids are oxidized become gluconeogenic precursors and cause a reduced need for gluconeogenesis from protein.     

A sensitive assay for measuring alpha-Gal epitope expression on cells by a monoclonal anti-Gal antibody

BACKGROUND: The distinction between solitary parathyroid adenoma and hyperplasia can sometimes be difficult during surgery for primary hyperparathyroidism (pHPT), especially in patients who have undergone previous thyroid or parathyroid surgery. The use of intraoperative parathyroid hormone (PTH) monitoring as a possible diagnostic tool was therefore investigated. METHODS: Intraoperative levels of PTH were measured in 119 patients during 121 operations (including 14 reoperations) for pHPT. The mean(s.d.) preoperative serum calcium level was 2.79(0.21) mmol/l. Blood samples were drawn before, and at 5 and 15 min after, excision of the first enlarged parathyroid gland. PTH was analysed electively in 61 patients and on-line by a modified assay for intact PTH in 48 patients. Both procedures were used in ten patients. RESULTS: The mean(s.d.) decline in PTH concentration in 101 patients with primary exploration due to solitary adenoma was 63(17) per cent after 5 min (n=84) and 83(10) per cent after 15 min. The patients with primary exploration because of multiglandular disease (n=6) were correctly predicted not to have parathyroid adenoma. CONCLUSION: Measurement of PTH levels during surgery for pHPT is a highly sensitive method for differentiating between single and multiple gland disease. The on-line monitoring of PTH is clinically useful in patients who have undergone previous neck surgery. Its role in pHPT surgery at primary exploration should be evaluated in prospective trials.     

Plasma prostaglandin metabolite concentrations in normal and dysfunctional labour

OBJECTIVE: To determine the concentrations of the metabolites of prostaglandin E2 (PGEM) and of prostaglandin F2 alpha (PGFM) prior to the onset of labour and during spontaneous labour, and to correlate the changes in concentrations of these metabolites with labour outcome. DESIGN: Longitudinal study throughout labour. SETTING: Labour ward of a large maternity unit. SUBJECTS: Seven primigravid and 11 parous women in the late third trimester with no signs of labour, and 17 primigravid and 11 parous women in spontaneous labour. INTERVENTIONS: Six of the primigravid women required augmentation with oxytocin because of dysfunctional labour. RESULTS: Before labour, parous women had significantly higher concentrations of both PGEM (P < 0.007) and PGFM (P < 0.006) compared with primigravid women. During labour, PGFM concentrations were significantly higher in both primigravid (P < 0.0002) and parous (P < 0.0001) women compared with the concentrations of these metabolites in women not in labour; the same was true for PGEM in primigravid (P < 0.003) but not in parous (P = 0.1) women. There was a small but significant increase (P < 0.02) in PGEM as labour progressed in both the normal groups. Amniotomy was associated with a significant increase in PGFM in primigravid and parous women (P < 0.002 and P < 0.009, respectively). The concentration of PGFM one hour following amniotomy correlated inversely with the amniotomy to delivery interval in both the normal primigravid (r = -0.624; P = 0.04) and the parous (r = 0.745; P = 0.021) groups. Women with dysfunctional labour showed no significant rise in PGEM or PGFM. Their PGFM concentrations were significantly lower than those seen in normal labour (P < 0.05). The concentration of PGFM in cord blood was significantly higher (P < 0.0001) in the parous women who laboured than in women delivered by elective caesarean section. There was no difference in the corresponding concentrations of PGEM (P = 0.9). CONCLUSIONS: These data show that spontaneous labour is associated with increased concentrations of prostaglandin metabolites in the maternal plasma, and are consistent with PGF2 alpha being an important stimulator of uterine contractility, with a relative deficiency of PGF2 alpha being associated with dysfunctional labour.