African green monkeys have sexually dimorphic and estrogen-sensitive hypothalamic neuronal membranes

Previous studies have shown sex differences in intramembrane particle content in the arcuate neurons of the rat hypothalamus. In this study, freeze-fracture replicas were prepared from the infundibular hypothalamus of adult African green monkeys (Cercopithecus aethiops) in order to determine whether primates also have sexual dimorphism in neuronal membranes. Intramembrane particles (IMP) were quantitatively assessed in the perikaryal plasma membranes of infundibular neurons. Four groups of monkeys were studied: intact males, intact females, ovariectomized females injected with 20 mg of estradiol valerate over 10 days and ovariectomized females injected with vehicle (castor oil). Membranes from females showed an increased numerical density of IMPs when compared to males. Ovariectomy of females did not affect IMP content, while estrogen administration resulted in a significant decrease in IMP numerical density to reach male values. These findings indicate a sex difference in neuronal membranes in the hypothalamus of monkeys and suggest that as in rodents, neuronal plasma membrane organization in higher primates may be modulated by gonadal steroids.

In vitro production of tumour necrosis factor and prostaglandin E2 by peripheral blood mononuclear cells from tuberculosis patients

We investigated the production of tumour necrosis factor-alpha (TNF-alpha) and prostaglandin E2 (PGE2) by peripheral blood mononuclear cells (PBMC) from tuberculosis patients and healthy controls. PBMC from tuberculosis patients generated constitutively more TNF-alpha than did control PBMC. This production was significantly higher for patients with high-grade fever and cachexia. The increase of TNF-alpha production by PBMC from tuberculosis patients was associated with a comparatively weaker elevation of PGE2 synthesis which did not parallel fever or weight loss. In vitro treatment of control PBMC with the tuberculin purified protein derivative (PPD) promoted an increased TNF-alpha production which was similar to that of untreated PBMC from tuberculosis patients. Thus, the increased TNF-alpha production in tuberculosis could be explained by the in vivo exposure of PBMC to mycobacterial antigens. In contrast, the concentration of PGE2 was weaker in the medium of untreated PBMC from tuberculosis patients than in the medium of PPD-treated control PBMC, suggesting that PGE2 synthesis by PBMC was limited in tuberculosis by unidentified factors.

Reduction in tumor necrosis factor binding and cytotoxicity by hydrogen peroxide

The regulatory effect of H2O2 on both the cytotoxic activity and the specific binding of TNF-alpha was studied by using TNF-alpha-sensitized murine L929 cells. When these cells were exposed simultaneously to TNF-alpha and H2O2 (100 to 500 microM), the cytotoxic activity of TNF-alpha was inhibited by up to 66.6%. This inhibition was also effective when the cells were pretreated by H2O2, but not when TNF-alpha alone was preexposed to H2O2. These data suggest that H2O2 altered the cell sensitivity to TNF-alpha, without modifying the activity of the TNF-alpha molecule. Maximum loss of cell sensitivity to TNF-alpha occurred after 30-min preexposure to 500 microM H2O2. Complete restoration of TNF-alpha sensitivity was obtained within 12 h after H2O2 removal. It required protein synthesis as demonstrated by the suppressive effect of actinomycin D. The inhibitory effect of H2O2 was suppressed by catalase, but was unaffected by the scavengers of hydroxyl radical and hypochlorous acid, suggesting that H2O2 but not one of its metabolites was responsible for this inhibition. H2O2 inhibitory effect did not implicate any change in prostaglandin production or in PKC activity. In contrast, H2O2 effect was associated with an about 50% loss of the density of cell membrane 125I-TNF-alpha receptors (2949 vs 5620 binding sites per cell), without change in their affinity (3.9 vs 3.4 nM). Moreover H2O2 did not affect the rate of degradation of TNF-alpha, and only slightly increased the degree of internalization of 125I-TNF-alpha receptors. These findings indicate that H2O2 can down-regulate the cellular response to TNF-alpha, possibly by reducing the TNF-alpha-binding capacity.

Reduction in tumor necrosis factor binding and cytotoxicity by hydrogen peroxide

The regulatory effect of H2O2 on both the cytotoxic activity and the specific binding of TNF-alpha was studied by using TNF-alpha-sensitized murine L929 cells. When these cells were exposed simultaneously to TNF-alpha and H2O2 (100 to 500 microM), the cytotoxic activity of TNF-alpha was inhibited by up to 66.6%. This inhibition was also effective when the cells were pretreated by H2O2, but not when TNF-alpha alone was preexposed to H2O2. These data suggest that H2O2 altered the cell sensitivity to TNF-alpha, without modifying the activity of the TNF-alpha molecule. Maximum loss of cell sensitivity to TNF-alpha occurred after 30-min preexposure to 500 microM H2O2. Complete restoration of TNF-alpha sensitivity was obtained within 12 h after H2O2 removal. It required protein synthesis as demonstrated by the suppressive effect of actinomycin D. The inhibitory effect of H2O2 was suppressed by catalase, but was unaffected by the scavengers of hydroxyl radical and hypochlorous acid, suggesting that H2O2 but not one of its metabolites was responsible for this inhibition. H2O2 inhibitory effect did not implicate any change in prostaglandin production or in PKC activity. In contrast, H2O2 effect was associated with an about 50% loss of the density of cell membrane 125I-TNF-alpha receptors (2949 vs 5620 binding sites per cell), without change in their affinity (3.9 vs 3.4 nM). Moreover H2O2 did not affect the rate of degradation of TNF-alpha, and only slightly increased the degree of internalization of 125I-TNF-alpha receptors. These findings indicate that H2O2 can down-regulate the cellular response to TNF-alpha, possibly by reducing the TNF-alpha-binding capacity.

Antenatal fetal diagnosis and maternal transport gastroschisis. A maternal-infant case report

Gastroschisis is a rare congenital birth defect of the abdominal wall that invariably is fatal if not managed appropriately. Early in utero diagnosis is now possible using maternal serum alpha-fetoprotein and ultrasound. As with other serious congenital disorders, antenatal diagnosis allows therapeutic options and time for preparation. Even if the diagnosis is made late, however, efforts to achieve prenatal maternal transport are still reasonable. The neonatal outcome of an unplanned delivery of an anomalous child requiring immediate attention is likely to be better if the delivery occurs in a tertiary center. These facilities generally have specialized services and teams available for critical care around the clock. The authors describe the maternal transport and delivery of a neonate with a serious disorder that required specialized attention at an hour when most hospitals are staffed with a skeleton crew. The necessary resources were available immediately, and the neonatal outcome was favorable. Although this report describes gastroschisis specifically, the concept of tertiary site delivery for potentially seriously ill neonates applies to any condition. With a late diagnosis, possible other anomalies, and a logistically unfavorable hour, the advantages of maternal transport are evident. This report also briefly reviews the area of antenatal ultrasound diagnosis and the newer mechanisms used to develop a perinatal care plan.

Mineralization of 14 C-Ring-Labeled Synthetic Lignin Correlates with the Production of Lignin Peroxidase, not of Manganese Peroxidase or Laccase

Recently, Mn(II) has been shown to induce manganese peroxidases (MnPs) and repress lignin peroxidases (LiPs) in defined liquid cultures of several white rot organisms. The present work shows that laccase is also regulated by Mn(II). We therefore used Mn(II) to regulate production of LiP, MnP, and laccase activities while determining the effects of Mn(II) on mineralization of ring-labeled synthetic lignin. At a low Mn(II) level, Phanerochaete chrysosporium and Phlebia brevispora produced relatively high titers of LiPs but only low titers of MnPs. At a high Mn(II) level, MnP titers increased 12- to 20-fold, but LiPs were not detected in crude broths. P. brevispora formed much less LiP than P. chrysosporium , but it also produced laccase activity that increased more than sevenfold at the high Mn(II) level. The rates of synthetic lignin mineralization by these organisms were similar and were almost seven times higher at low than at high Mn(II). Increased synthetic lignin mineralization therefore correlated with increased LiP, not with increased MnP or laccase activities.

Hepatic alcohol dehydrogenase activity in alcoholic subjects with and without liver disease

Alcohol dehydrogenase activity was measured in samples of liver tissue from a group of alcoholic and non-alcoholic subjects to determine whether decreased liver alcohol dehydrogenase activity is a consequence of ethanol consumption or liver damage. The alcoholic patients were classified further into the following groups: control subjects with no liver disease (group 1), subjects with non-cirrhotic liver disease (group 2), and subjects with cirrhotic liver disease (group 3). The non-alcoholic subjects were also divided, using the same criteria, into groups 4, 5, and 6, respectively. The analysis of the results showed no significant differences when mean alcohol dehydrogenase activities of alcoholic and non-alcoholic patients with similar degrees of liver pathology were compared (groups 1 v 4, 2 v 5, and 3 v 6. Alcohol dehydrogenase activity was, however, severely reduced in patients with liver disease compared with control subjects. Our findings suggest that alcohol consumption does not modify hepatic alcohol dehydrogenase activity. The reduction in specific alcohol dehydrogenase activity in alcoholic liver disease is a consequence of liver damage.

Serodiagnosis of leprosy in patients' contacts by enzyme-linked immunosorbent assay

Serum samples from 3336 contacts of leprosy patients were tested for antiphenolic glycolipid I antibodies by enzyme-linked immunosorbent assay with the albumin coupled synthetic disaccharide antigen. The overall positivity rate was 9.3%. No significant differences were seen between a group of household contacts of lepromatous patients and those of the other types of the disease. The proportion of ELISA positives was slightly higher in the relatives as compared to workplace contacts and neighbours but significantly different only between the two former (p less than 0.05). Among those contacts with absorbance values higher than 0.100, 5 new leprosy patients were diagnosed, 2 of them with positive skin smears. A sixth contact was detected with a very high absorbance value in whom no single skin lesion was found but whose lepromin reaction was 0 mm and the skin smear showed a bacteriological index of 3+.

Single-breath carbon monoxide diffusing capacity prediction equations from a Mediterranean population

Because of unanswered questions about prediction equations for the single-breath carbon monoxide diffusing capacity (DLCO) and as part of a larger collaborative project, standardized DLCO measurements were carried out in a selected sample of 361 healthy nonsmoking volunteers (194 men and 167 women) living in the Barcelona metropolitan area (Spain). Except for the test FIO2 (0.18), the study essentially followed the American Thoracic Society (ATS) and European Community for Coal and Steel (ECCS) recommendations for standardizing the methodology of measuring DLCO. Prediction equations for ages 20 through 70 were calculated separately for both sexes. Simple linear equations using age, height, and body weight as independent variables predicted the DLCO indices (DLCO, VA, and DL/VA) as well as more complex equations. In addition, a complete analysis of the residuals (predicted measured values) showed that the assumptions of the multiple regression analysis (independence, homoscedasticity and Gaussian distribution of residuals) were fulfilled using simple linear equations. Correction for the instrumental and anatomic dead spaces decreased the DLCO an average of 4.7%. The standard error of estimates was lower than those reported from other series in the literature. The predicted values from this study were lower than those reported by some investigators and were in reasonable agreement with other studies. A portion but not all of the differences could be explained on the basis of recognized differences in testing methodology. The results of this study may be of value to clinical laboratories seeking predictive equations for DLCO most appropriate for their testing methodology and patient population, and may assist in the resolution of some controversies regarding differences among predictive equations for DLCO.

Gap junctions in the hypothalamic arcuate neurons of ovariectomized and estradiol-treated rats

Freeze-fracture methodology was used to study the organization of the neuronal plasma membrane in the rat arcuate nucleus, an estrogen sensitive area of the hypothalamus. Freeze-fracture replicas were prepared from 6 adult ovariectomized rats injected with a single dose of 17 beta-estradiol and from 6 ovariectomized littermates injected with vehicle. Rats were sacrificed 2 days after the injection. Occasional gap junctions were observed in freeze-fractured neuronal membranes from both groups of animals and their incidence was increased (P less than 0.01) in estradiol treated rats. This study demonstrates gap junctions in arcuate neurons and suggests that these structures may be affected by gonadal hormones.

Gonadal influences on behavioral deterioration with aging of male rats

There is much evidence that gonadal steroids modulate brain and behavioral development. However their possible influence on age-related deteroriation of brain and behavior has received little attention. We now present evidence that neonatal castration reduces the decline in locomotion, motor coordination, and circadian activity rhythms that normally accompanies old age in male rats. Three behavioral tests (open field, Rota-Rod, and wheel running) were conducted with aged male rats (24 months). Those castrated in the first 24 hr of postnatal life were more active in the open field (P less than 0.001) than aged rats that were sham-operated neonatally. The sham-operated aged males showed a more marked deterioration of motor coordination in the Rota-Rod (P less than 0.01) and greater disorganization of circadian wheel-running (P less than 0.05) than the neonatal castrates or than young rats neonatally sham-operated.

Signet ring cell sinus histiocytosis. A previously unrecognized histologic condition mimicking metastatic adenocarcinoma in lymph nodes

The axillary lymph nodes in a radical mastectomy specimen from a 70-year-old insulin-dependent diabetic patient contained significantly vacuolated sinus histiocytes. The histologic picture closely resembled metastatic signet ring cell adenocarcinoma. The signet ring histiocytes did not stain with the mucicarmine or periodic acid-schiff stains or any of the immunohistochemical epithelial markers. The differential diagnosis and the possible origin of these vacuolated histiocytes are discussed.

cAMP-dependent phosphorylation of soluble and crude microtubule fractions of rat cerebral cortex after prolonged desmethylimipramine treatment

We have analyzed the cAMP-dependent phosphorylation system in the cerebral cortex and hippocampus of rats after acute and chronic administration of desmethylimipramine. Prolonged desmethylimipramine administration modified the cAMP-dependent endogenous phosphorylation of a protein band with apparent molecular weight 280 kDa from the cerebrocortical-soluble fraction. The effect appeared to be specific and associated with the chronic but not the acute administration of desmethylimipramine since we did not obtain any modification in other endogenous cAMP phosphoproteins of either the particulate or soluble fraction of the cerebral cortex. 280 kDa was identified as the soluble microtubule associated protein 2 on the basis of molecular weight, endogenous phosphorylation and immunological recognition. Prolonged desmethylimipramine administration did not induce any modification in the soluble cAMP-dependent endogenous phosphorylation of 280 kDa in other brain areas such as hippocampus, striatum or cerebellum, suggesting a region-specific effect of chronic desmethylimipramine treatment. Microtubule-associated protein 2 is a neuronal protein highly enriched in the dendritic portion of neurons and represents one of the major substrates in the cell for the type II cAMP protein kinase. Since the type II cAMP protein kinase that catalyzes the phosphorylation of microtubule-associated protein 2 copurifies with microtubules, we performed endogenous phosphorylation using increasing concentrations of cAMP in a crude microtubule preparation where microtubule-associated protein 2 appeared to be more concentrated. Under our conditions the maximal effect occurred at 1 microM cAMP, revealing increased 32P incorporation in microtubule-associated protein 2 from a crude microtubule preparation obtained from the cerebral cortex of rats treated with desmethylimipramine. Photoaffinity labelling with 8-azido-[32P]cAMP of the various fractions obtained during the preparation of crude microtubules (S1, S2 and crude microtubules) revealed an increase in the labelling of a protein band with apparent molecular weight of 52 kDa after desmethylimipramine treatment. The labelling of a 47 kDa protein band, which is also present in S1 and S2 fractions was, however, not altered by drug treatment. In conclusion, our studies demonstrated that prolonged desmethylimipramine treatment elicited specific changes in the phosphorylation system associated with a crude microtubule fraction.

Leukotriene D4-induced proliferation of glomerular epithelial cells: PKC- and Na+-H+ exchanger-mediated response

The growth-promoting effect of leukotriene D4 (LTD4) has been observed in a variety of cells, including human glomerular epithelial cells. The purpose of this study was to determine the mechanisms underlying this process. LTD4 induction of [3H]thymidine uptake in human glomerular epithelial cells was blocked by the LTD4 receptor antagonist L648,051 when added in a 50-fold excess and by pertussis toxin. Neither drug affected basal DNA synthesis. These results suggest that the LTD4-mediated signal transduction implies activation of a GTP-binding protein that is coupled to a specific receptor. The possible role of protein kinase C (PKC) activation was also studied. In the presence of the PKC inhibitor H-7 or after downregulation of PKC levels by chronic treatment with phorbol ester, stimulation of [3H]thymidine uptake by LTD4 was greatly inhibited. Moreover, treatment of the cells by LTD4 resulted in a time-dependent increase of cytosolic PKC activity, whereas addition of phorbol 12-myristate 13-acetate reduced this activity. Therefore PKC-dependent mechanisms are likely to mediate the growth-promoting effect of LTD4. Finally, three approaches were used to determine the potential role of the Na+-H+ exchanger. First, progressive removal of extracellular Na+ using N-methyl-D-glucamine+ as a substitute inhibited LTD4-induced [3H]thymidine uptake with a 50% inhibitory concentration (IC50) of 85 mM. Second, addition of amiloride reduced the LTD4 growth effect with an IC50 of 6.5 microM, whereas three amiloride analogues exhibited lower IC50 values in accordance with their greater affinity for the Na+-H+ exchanger.(ABSTRACT TRUNCATED AT 250 WORDS)

Disparate urinary catecholamine patterns in secondary hypertension due to unique sequential development of pheochromocytoma and neuroblastoma

A 43-year-old white woman had a pheochromocytoma removed from her left adrenal gland, and one year later she developed a new left upper abdominal mass that was found to be a neuroblastoma. On both occasions, urinary vanillylmandelic acid level was elevated. However, urinary norepinephrine and epinephrine levels were increased only during the pheochromocytoma episode, while the urinary homovanillic acid level was elevated only when neuroblastoma developed. Despite a high suspicion of pheochromocytoma recurrence, the urinary catecholamine profile was suggestive of neuroblastoma, which was revealed by histopathologic analysis of the tumor tissue.

In vivo transillumination of the hand using near infrared laser pulses and differential spectroscopy

In vivo dual wavelength differential spectrography was performed on the hand of an adult male, using a collimated transillumination device. A pulsed laser with sufficiently high peak power and sufficiently low energy was employed so that transillumination could be realized without thermal damage. Spectrochemical analysis based on the absorbance of oxygen transporting molecules (OTM), i.e. haemoglobin in blood vessels and myoglobin in muscles, was performed along a 70 mm scanning line within the near-red infrared range. The two wavelengths used (675 and 800 nm) were chosen on the basis of the absorption spectrum of haemoglobin. The profiles computed with differential spectrography data related to the oxygen saturation of OTM are closely correlated with X-ray densitometry of the most vascularized tissues in the hand along the scanning line. In addition, at 675 nm, the profiles are rapidly modified as a function of the oxygen supply to the hand. Considering the accuracy obtained for the spatial localization of the OTM redox state, it is expected that these results could be applied to imaging.

Pulmonary phospholipids in amniotic fluid of pathologic pregnancies: relationship with clinical status of the newborn

We evaluated phospholipids, C-peptide and cortisol levels in amniotic fluid of 203 pathologic pregnancies (63, class A, B and C diabetics; 11 class D, F and H diabetics; 44 preclampsia and 85 Rh-isoimmunization); the control group was 82 normal pregnant women. There was an acceleration of fetal pulmonary maturation in women with preclampsia and severe Rh-isoimmunization in class D, F and H diabetics (at 34 weeks gestation the incidence of mature surfactant (lecithin/sphingomyelin greater than or equal to 2.7 and presence of phosphatidyl-glycerol) in these groups was 30%, 50% and 100%, respectively, while it was zero in the control group). At 37 and 38 weeks only 44.4% of the class A, B and C diabetics had mature surfactant and there was a significant difference with respect to the control group (x2 = 4.9; p less than 0.05); C-peptide levels in these diabetics (class A, B and C) were higher than in controls (p less than 0.001); in pregnant women with accelerated fetal lung maturation they were lower. We demonstrated a close relationship between fetal pulmonary maturity and the type of surfactant in amniotic fluid, which was independent of gestational age.

[Organization of a pedodontic residency in the interior of the country]

Since 1981 there is an Odontopediatric residence in Azul, Pcia. de Bs. As., Argentina. The resident accomplish a three year cycle and obtain a Scholarship payed by Health Ministry of Provincia de Bs. As. The educational curricula is basic and points to the essential aim of health preservation putting aside disease treatment as a way to achieve it.

Sex differences in plasma membrane concanavalin A binding in the rat arcuate neurons

Previous studies have shown that synaptic connections and organization of neuronal membranes are sexually dimorphic in the arcuate nucleus of developing and adult rats. These sex differences can be abolished by the perinatal androgenization of females. In this study the label-fracture method of Pinto da Silva and Kan was used in order to determine whether membrane sex differences are related to the glycoconjugates in neuronal plasma membranes. Six Sprague-Dawley female rats treated with testosterone on the day of birth, six control females injected with vehicle and six intact males were studied when they were 100 days old. The arcuate nucleus was dissected and incubated for 2 hours in a solution of 0.25 mg/ml concanavalin A, washed in buffer and incubated for 3 hours in a suspension of horseradish peroxidase-coated colloidal gold. Then, freeze-fracture replicas of the arcuate nucleus were prepared. Colloidal gold labeling was observed to be codistributed with intramembrane particles in the outer membrane face of the neuronal perikaryal plasma membrane. The numerical density of small (less than 10 nm) intramembrane particles and colloidal gold particles was significantly greater in control female membranes when compared to males or to androgenized females. The labeling was significantly reduced when the arcuate nucleus was incubated with concanavalin A in presence of 0.5 M methyl-alpha-manopyranoside. These findings indicate a sex difference in the density and distribution of glycoconjugates and intramembranous particles in the neuronal plasma membrane that is dependent on the perinatal levels of sex steroids and is concordant with, and could be the cause of, sex differences in the pattern of synaptic contacts.

Synaptic remodeling in the rat arcuate nucleus during the estrous cycle

Adult female rats showing regular vaginal cycles were studied in order to determine the number of axosomatic synapses in thin sections of the arcuate nucleus. The number of synapses per length of perikaryal membrane was significantly decreased in estrus, compared to other days of the estrous cycle (P less than 0.05). The reduction in the number of synapses in estrus was accompanied by a decrease in the percentage of the average length of perikaryal membrane covered by presynaptic terminals and by an increase in the percentage of membrane in close apposition of glial processes. Since the average perikaryal perimeter was not significantly changed during the estrous cycle, these results indicate a net decrease in the number of arcuate nucleus axosomatic synapses between proestrus and estrus, with a reinnervation of arcuate neurons between estrus and metestrus. These results suggest that there is a physiological synaptic turnover in the arcuate nucleus of the rat during the estrous cycle.

Relation between delay and survival in 596 patients with breast cancer

To evaluate the influence of delay between first symptom and first treatment upon survival the medical records of 596 patients with breast cancer were reviewed. The following intervals were considered: less than 3 months; 3-6 months and greater than 6 months. Patients in the less than 3 months delay group had a better distribution by clinical stages and a 10-year survival rate higher than those in the longer delay groups (p = 0.034). However, within each stage no statistically significant difference in survival according to delay was observed. A Cox multivariate analysis revealed that performance status and stage of disease were independent predictors of survival, but not delay. Assuming the best prognosis for patients with clinical stages I and II and less than 3 months delay, the group with longer delay times had 15 deaths over what would have been predicted. This adverse effect was observed almost exclusively among patients over age 50 (14/15).

Tumor necrosis factor stimulates prostaglandin production and cyclic AMP levels in rat cultured mesangial cells

Human recombinant tumor necrosis factor-alpha (TNF) was found to stimulate the production of prostaglandins (PG) by cultured rat mesangial cells. This effect was demonstrable from 6 h, was dose dependent and affected the synthesis of PGE2, PGF2 alpha, and 6-keto-PGF1 alpha. It required both RNA and protein synthesis but was not associated with a modification of cell proliferation. TNF also stimulated adenosine 3'-5' cyclic monophosphate (cAMP) levels in the mesangial cell culture medium. Indomethacin suppressed the effect of TNF on PGs but only reduced that on cAMP, indicating that PG production partly mediates the increase in cAMP. These findings demonstrate that mesangial cells can be a target for TNF and that the mechanism of TNF action includes stimulation of both PG production and cAMP levels.

Effects of diet and feeding time on daily variations in plasma insulin, hepatic c-AMP and other metabolites in a teleost fish,Dicentrarchus labrax L

Juvenile sea bass, 1.5 years old, of mixed sex, held on long photoperiods were fed early on the photoperiod and late on the photoperiod, using different diets. Fish fed natural diets showed a daily rhythmicity of plasma insulin, liver c-AMP, plasma glucose, liver glycogen and muscle glycogen content, however, fish fed a commercial diet did not show this daily rhythmicity except for plasma insulin levels. In addition, these fish had significantly lower levels of plasma insulin, liver c-AMP and plasma glycerol than the group fed on the natural diets at similar feeding times. The time of feeding also induced different rhythmicity patterns in hormones and metabolites as well as a significant change in their mean levels. These facts are discussed in relation with the pre-feeding activity and increased appetite exhibited by the fish fed late on the photoperiod and with their implications on fish culture.

Sexual differentiation of the neuronal plasma membrane: neonatal levels of sex steroids modulate the number of exo-endocytotic images in the developing rat arcuate neurons

Exo-endocytotic images and intramembrane protein particles (IMP) were quantitatively assessed in freeze-fracture replicas from the plasma membrane of arcuate neurons of rats aged 0 (newborns), 10, 20 and 100 days postpartum. Membranes contained significantly (P less than 0.02) more IMPs in females than in males. Exo-endocytotic images were increased in newborn and 10-day-old males when compared to adult males or to developing females (48 +/- 6 vs 6 +/- 1 images/100 micron 2 in 10-day-old male and female rats, respectively). Androgenization of females with a single injection of testosterone propionate on the day of birth resulted in an increased number of exo-endocytotic images in developing animals (75 +/- 9 images/100 micron 2, 10-day-old rats) and in the abolishment of the sex differences in the number of IMPs.

Estrogen modulation of the gamma-aminobutyric acid receptor complex in the central nervous system of rat

Administration of estradiol benzoate to ovariectomized rats results in an increased binding of [3H]muscimol, [3H]diazepam and 35S-t-butylbicyclophosphorothionate in various areas of the central nervous system of rats. The effect is dose-dependent and its onset can be observed as early as 12 hr after s.c. administration of the hormone. The various binding activities are differentially affected by the hormonal treatment: the maximal effect observed for [3H]diazepam binding is in the cerebellum (+42%), for [3H]muscimol binding in the frontal cortex (+84%) and for 35S-t-butylbicyclophosphorothionate binding in the striatum (+46%) indicating that the activities of the sites are not under the same cellular regulatory control. The estrogen-induced increase in [3H]diazepam binding sites does not result in an increased protection against chemoconvulsants such as pentylenetetrazole.

Relationship between elevated plasma levels of crosslinked fibrin degradation products (XL-FDP) and the clinical presentation of patients with myocardial infarction

To assess whether the intense thrombotic state known to occur early after the onset of acute myocardial infarction is further exacerbated by impaired intrinsic fibrinolysis, we compared the intensity of fibrinolysis as measured by the level of crosslinked fibrin degradation products (XL-FDP) in plasma with the intensity of thrombosis as assessed by fibrinopeptide A (FPA) in 98 patients with transmural and 14 patients with non-Q wave infarction. Patients without complications of infarction such as shock, mural thrombi, or malignant arrhythmias requiring countershock generally had normal plasma levels of XL-FDP, less than or equal to 300 ng/ml (81% of those presenting less than 8 hours after onset and 66% of those presenting greater than 8 hours after onset) on admission despite elevated FPA indicative of ongoing thrombosis. In contrast, patients with complications generally had elevated levels of XL-FDP greater than 300 ng/ml (80% of those presenting early and 62.5% of those presenting late) and 50% of these patients had marked elevations to greater than 1000 ng/ml. FPA was markedly elevated in patients with complications whether they presented early or late after onset of infarction. Our direct measurements at the time of infarction support previous data indicating that intrinsic fibrinolysis is impaired in patients with acute infarction, despite marked thrombin activity, when complications are not present. However, when complications are present initially, a more exuberant fibrinolytic response is observed perhaps due to thrombosis associated with the complications themselves.

Modulation of fibroblast proliferation by sulfidopeptide leukotrienes: effect of indomethacin

Because infiltration of mononuclear cells and fibroblast proliferation are associated in chronic inflammatory lesions, we tested the hypothesis that leukotrienes (LT), a product of activated mononuclear cells, may modulate fibroblast growth. Proliferation of cultured human skin fibroblasts was estimated by [3H]thymidine incorporation and cell count at increasing concentrations (0.1 nM to 0.1 microM) of LTC4 or LTD4. LTC4 and LTD4 stimulated cell growth in a dose-dependent manner only in the presence of 50 microM indomethacin. Under similar conditions, LTE4 but not LTB4 (0.1 microM) was active. Both asynchronous, growing cells and synchronous, quiescent cells were sensitive to LT when prostaglandin (PG) synthesis was suppressed by indomethacin. Other blockers of cyclooxygenase such as ibuprofen and aspirin exhibited identical permissive activity, and the effect of indomethacin was totally abolished by addition of PGE2. LTC4 modified neither [3H]arachidonic acid release from prelabeled fibroblasts nor PGE2 production by fibroblasts. These results demonstrate that the sulfidopeptide LT stimulate fibroblast proliferation only when the endogenous synthesis of PG is blocked, but they do not enhance the synthesis of PG in their target cells showing no evidence for a negative feed-back loop. Nevertheless, it seems likely that the initiation and development of the fibrotic process in the different tissues depends in part on the local balance between PG and LT productions.

Modulation of fibroblast proliferation by sulfidopeptide leukotrienes: effect of indomethacin

Because infiltration of mononuclear cells and fibroblast proliferation are associated in chronic inflammatory lesions, we tested the hypothesis that leukotrienes (LT), a product of activated mononuclear cells, may modulate fibroblast growth. Proliferation of cultured human skin fibroblasts was estimated by [3H]thymidine incorporation and cell count at increasing concentrations (0.1 nM to 0.1 microM) of LTC4 or LTD4. LTC4 and LTD4 stimulated cell growth in a dose-dependent manner only in the presence of 50 microM indomethacin. Under similar conditions, LTE4 but not LTB4 (0.1 microM) was active. Both asynchronous, growing cells and synchronous, quiescent cells were sensitive to LT when prostaglandin (PG) synthesis was suppressed by indomethacin. Other blockers of cyclooxygenase such as ibuprofen and aspirin exhibited identical permissive activity, and the effect of indomethacin was totally abolished by addition of PGE2. LTC4 modified neither [3H]arachidonic acid release from prelabeled fibroblasts nor PGE2 production by fibroblasts. These results demonstrate that the sulfidopeptide LT stimulate fibroblast proliferation only when the endogenous synthesis of PG is blocked, but they do not enhance the synthesis of PG in their target cells showing no evidence for a negative feed-back loop. Nevertheless, it seems likely that the initiation and development of the fibrotic process in the different tissues depends in part on the local balance between PG and LT productions.

Estrogen-induced up-regulation of gamma-aminobutyric acid receptors in the CNS of rodents

Previous studies have identified an effect of estrogen administration on the number of central GABAergic binding sites of rat. We have further characterized this effect by performing a series of experiments in vitro where we analyzed the changes of gamma-aminobutyric acid (GABA) binding in slices of nervous tissue incubated in a physiological medium in presence of estradiol. The tissues were dissected from ovariectomized rats. In such a system, estrogen augmented the amount of [3H]muscimol binding within 3 h of incubation. The effect was dose-dependent and could be blocked by the addition of the anti-estrogen tamoxifen. The increase in [3H]muscimol binding could not be observed by addition of estradiol to broken membranes or by incubation of the slices with steroids deprived of estrogenic activity. Furthermore, the estrogen-induced increase of GABA binding sites could be prevented by addition of cycloheximide and alpha-amanitin in the incubation medium. Our data indicate that the estrogen may increase the number of GABA binding sites by direct interaction with the GABA receptor gene or genes involved in the metabolism of GABA receptor.

Sexual dimorphism in the response of the GABAergic system to estrogen administration

Administration of estradiol benzoate to gonadectomized female rats results in up-regulation of CNS gamma-aminobutyric acid (GABA) receptors. The increase of [3H]muscimol binding activity is observed in six of the seven brain areas examined. The same treatment, performed in castrated male or androgenized female rats, induced an increase of [3H]muscimol binding only in the striatum. Evidence is provided suggesting that the dimorphic sensitivity of GABA receptor is not correlated with the difference in spontaneous motor activity reported between male and female rats.

Dexamethasone and hydrogen peroxide production by mesangial cells during phagocytosis

We have previously demonstrated that a high percentage of rat cultured mesangial cells phagocytized serum-treated zymosan (STZ) (L. Baud, J. Hagege, J. Sraer, E. Rondeau, J. Perez, and R. Ardaillou, J. Exp. Med. 158: 1836-1852, 1983). Phagocytosis resulted in stimulation of arachidonic acid metabolism with generation of H2O2. Exposure of mesangial cells to dexamethasone for 48 h produced a dose-dependent decrease in phagocytosis-induced production of H2O2 with a 50% inhibitory concentration of 32 nM. The decrease in H2O2 release was associated with the inhibition of prostaglandin (PG) E2 production. The effect of dexamethasone could be considered as due to receptor-mediated modulation of protein synthesis since dexamethasone was not active immediately but only after a lag period of 3 h; RU 38486, a potent competitor for dexamethasone receptors, counteracted the reduction in H2O2 generation; and actinomycin and cycloheximide both blunted the inhibitory effect of dexamethasone. Pretreatment of mesangial cells with dexamethasone also produced a dose-dependent decrease in the phagocytic capability of the cells (63% inhibition for 1 microM dexamethasone). However, the inhibitory effect of dexamethasone on H2O2 production expressed as percentage of control was similar whether or not phagocytosis had been blocked by cytochalasin B. This result and also the fact that dexamethasone inhibited H2O2 production in cells triggered with soluble stimuli (A 23187 ionophore, PAF) suggested that the effect of dexamethasone on H2O2 generation was independent of that on phagocytosis. Addition of exogenous arachidonic acid reduced the effect of dexamethasone only when its conversion into PGE2 was inhibited by indomethacin.(ABSTRACT TRUNCATED AT 250 WORDS)