Pharmacokinetics of rokitamycin after single administration to healthy volunteers

The pharmacokinetics of rokitamycin tablets were studied in 12 healthy volunteers in a randomized cross-over design. The doses tested were 200 mg, 300 mg, 400 mg and 600 mg, as single oral administration. Rokitamycin was absorbed quickly with Tmax for all doses around 30 min after drug intake. Total AUC and Cmax values were linearly related to the administered dose. The buffer formulation determined a low interindividual variation. The overall findings show a good similarity with the data obtained in Japanese subjects. Tolerability was very good.

Serum copper, zinc and magnesium in maternal and cord blood at delivery

Serum concentrations of copper, zinc and magnesium were determined in maternal and cord blood at delivery in term pregnancies among healthy Nigeria women. Maternal serum copper concentration was significantly higher than cord serum concentration. There were no significant differences in maternal and cord serum levels of zinc and magnesium.

Selective attenuation by perivascular blood of prostanoid-dependent cerebrovascular dilation in piglets

Cerebral hemorrhagic insults are common in neonates. However, the consequences of intracranial blood on cerebral hemodynamics are poorly understood. We examined the effects of perivascular blood on cerebrovascular dilator responses in 29 piglets. Fresh, autologous blood (n = 15) or cerebrospinal fluid (n = 14) was placed under the dura mater over the parietal cortex, and the piglets were allowed to recover from anesthesia. One to four days later, a closed cranial window was placed over the parietal cortex and pial arteriolar responses to arterial hypercapnia (PaCO2 greater than 55 mm Hg), hemorrhagic hypotension (mean arterial blood pressure less than 35 mm Hg), or topical application of 10(-6) and 10(-4) M isoproterenol were determined. Pial arterioles in the cerebrospinal fluid group dilated 27 +/- 4% (mean +/- SEM) (n = 11) in response to hypercapnia, 26 +/- 5% (n = 9) in response to hypotension, and 26 +/- 3% in response to 10(-6) M and 40 +/- 4% in response to 10(-4) M isoproterenol (n = 11). In the group in which blood was placed on the parietal cortex, pial arterioles did not dilate significantly in response to hypercapnia (8 +/- 3%, n = 11) or hypotension (2 +/- 5%, n = 13) but dilated normally in response to isoproterenol (25 +/- 5% in response to 10(-6) M and 36 +/- 7% in response to 10(-4) M, n = 13). We conclude that prolonged contact of pial arterioles with extravascular blood selectively attenuates cerebrovascular dilation in piglets.

Increase of auto anti-phosphatidylinositol antibodies in plasma of female rats during the appearance of DMBA-induced malignant mammary tumors

Using a lipid-adapted ELISA, antiphosphatidylinositol (PtdIns) antibodies (Ab) have been found in sera of cancer patients. With the same procedure, we have checked their possible raising in plasma of female rats during the appearance of 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary tumors. Twenty days after DMBA administration, the mean anti-PtdIns Ab level was already higher than that of control rats (oil). Immunochemical analysis of the anti-PtdIns Ab site showed a rather high Ab avidity (8 x 10(-9) M, at half-displacement) and high specificity for glyceryl phosphate inositol residues. Other phospholipids (PL) were not recognized by the anti-PtdIns Ab induced by malignant cell transformation.

Effect of fish diet versus meat diet on blood lipids, coagulation and fibrinolysis in healthy young men

Twelve healthy young men followed a 10-d controlled diet that included 210 g of fatty fish d-1. The diet was repeated after 18 d, but with lean meat substituted for fish. Blood samples were collected for assessment of serum lipids and haemostatic variables in the plasma. Both experimental diets caused serum triglycerides and plasma factor VIIc to decline to the same extent. The meat diet was also associated with significant changes in plasma levels of tissue plasminogen activator (t-PA) antigen. PA inhibitor type I (PAI-1) antigen, PAI activity, and t-PA activity of the euglobulin fraction of plasma. The fish diet left these variables unchanged from initial values. Thus, in a paired comparison of the two diets, the fish diet was associated with higher levels of t-PA antigen (5.4 vs. 4.7 g ml-1), which is considered to be beneficial with regard to prevention of cardiovascular disease. However, the fish diet was concurrently associated with the putative unfavourable higher levels of PAI-1 antigen (3.0 vs. 1.2 ng ml-1) and PAI activity (6.1 vs. 3.2 IU ml-1), and lower t-PA activity (80 vs. 140 mIU ml-1). Thus it is unclear which of the two diets has the greatest potential in the prevention of cardiovascular disease.

Estimation of absorbed doses in humans due to intravenous administration of fluorine-18-fluorodeoxyglucose in PET studies

Radiation absorbed doses due to intravenous administration of fluorine-18-fluorodeoxyglucose in positron emission tomography (PET) studies were estimated in normal volunteers. The time-activity curves were obtained for seven human organs (brain, heart, kidney, liver, lung, pancreas, and spleen) by using dynamic PET scans and for bladder content by using a single detector. These time-activity curves were used for the calculation of the cumulative activity in these organs. Absorbed doses were calculated by the MIRD method using the absorbed dose per unit of cumulated activity, "S" value, transformed for the Japanese physique and the organ masses of the Japanese reference man. The bladder wall and the heart were the organs receiving higher doses of 1.2 x 10(-1) and 4.5 x 10(-2) mGy/MBq, respectively. The brain received a dose of 2.9 x 10(-2) mGy/MBq, and other organs received doses between 1.0 x 10(-2) and 3.0 x 10(-2) mGy/MBq. The effective dose equivalent was estimated to be 2.4 x 10(-2) mSv/MBq. These results were comparable to values of absorbed doses reported by other authors on the radiation dosimetry of this radiopharmaceutical.

Histochemical demonstration of 5'-nucleotidase activity in inflammatory muscle disease

Using a histochemical method, 5'-nucleotidase activity was investigated in 80 muscle biopsy specimens, including specimens from eight patients with muscular dystrophy, 18 with nonspecific type II fiber atrophy, 15 with polymyositis, and 29 histologically normal controls. An interstitial reaction for 5'-nucleotidase was associated with an inflammatory infiltrate in 19 of 21 positive cases. Of the 15 cases of polymyositis, 14 showed an extensive interstitial reaction surrounding most of the myofibers and extending well away from the areas infiltrated by inflammatory cells. The extensive nature of this reaction makes 5'-nucleotidase activity a useful adjuvant in the diagnosis of inflammatory muscle disease.

Steady-state response characteristics of a pulse oximeter on equine intestine

The steady-state response characteristics of a pulse oximeter were evaluated on intestinal segments of seven clinically normal halothane-anesthetized horses. Arterial oxygen tension greater than 200 mm of Hg, end tidal carbon dioxide from 30 to 35 mm of Hg, and systemic mean arterial pressure greater than 70 mm of Hg were maintained throughout the recording periods. Values for percentage of pulse oximeter oxygen saturation, pulsatile blood flow, and percentage of signal strength were recorded from jejunum, ileum, cecum, left ventral colon, left dorsal colon, and descending colon. Probe placement on intestinal segments was recorded as over or not over visible subserosal or transmural vessels. There was no significant difference between median values on the basis of vessel codes for pulse oximeter oxygen saturations, pulsatile flow, and signal strength. Median values recorded for pulse oximeter oxygen saturation were 93% from jejunum and ileum and 95% from cecum, left ventral colon, left dorsal colon, and descending colon; median values for pulsatile flow were 576 from jejunum, 560 from ileum, 560 from cecum, 574 from left ventral colon, 578 from left dorsal colon, and 560 from descending colon; median values for signal strength were 50% from jejunum, 67.5% from ileum, 60% from cecum, 75% from left ventral colon, 50% from left dorsal colon, and 52.5% from descending colon. Median values obtained from each anatomic location were not significantly different for pulsatile flow or signal strength. Median pulse oximetry oxygen values recorded from jejunum and ileum were significantly lower than values obtained from other intestinal segments.(ABSTRACT TRUNCATED AT 250 WORDS)

Enumeration of S-phase cells in normal rat liver by immunohistochemistry using bromodeoxyuridine-antibromodeoxyuridine system

The visualization of incorporation sites of the thymidine analog bromodeoxyuridine (BrdU) into DNA, detected by immunocytochemistry, has been proposed as an index of the percentage of S-phase cells in a variety of tissues and as an easy, less expensive alternative to autoradiography. This technique has not yet been applied to the study of physiological cell renewal in the normal liver. In the present study, results obtained with this method in the liver of normal young adult rats is reported. BrdU was administered in vivo and subsequent incorporation was detected by the PAP technique using monoclonal anti-BrdU antibodies. The nuclei exhibiting a positive reaction within the liver were few and accounted for about 0.45% of all hepatocytes. Positive cells were located preferentially in zone 1, which contained 82.7% of the labeled cells. Zone 2 contained 15.4%, while only 1.9% of the labeled cells were found in zone 3. Positive-staining Kupffer cell nuclei were rare (about 0.5% of all Kupffer cells) and were distributed randomly in the hepatic lobule. These findings provide quantitative data about hepatocyte renewal in the normal liver in the absence of a growth stimulus. The simplicity and the reproducibility of this technique suggests that further application of this method in situations assessing hepatic regeneration are indicated.

Brain polyphosphoinositide metabolism during focal ischemia in rat cortex

Using a rat model of stroke, we examined the effects of focal cerebral ischemia on the metabolism of polyphosphoinositides by injecting 32Pi into both the left and right cortices. After equilibration of the label for 2-3 hours, ischemia induced a significant decrease (p less than 0.001) in the concentrations of labeled phosphatidyl 4,5-bisphosphates (66-78%) and phosphatidylinositol 4-phosphate (64-67%) in the right middle cerebral artery cortex of four rats. The phospholipid labeling pattern in the left middle cerebral artery cortex, which sustained only mild ischemia and no permanent tissue damage, was not different from that of two sham-operated controls. However, when 32Pi was injected 1 hour after the ischemic insult, there was a significant decrease (p less than 0.01) in the incorporation of label into the phospholipids in both cortices of four ischemic rats compared with four sham-operated controls. Furthermore, differences in the phospholipid labeling pattern were observed in the left cortex compared with the sham-operated controls. The change in labeling pattern was attributed to the partial reduction in blood flow following ligation of the common carotid arteries. We provide a sensitive procedure for probing the effects of focal cerebral ischemia on the polyphosphoinositide signaling pathway in the brain, which may play an important role in the pathogenesis of tissue injury.

Effects of insulin and amino acids on leg protein turnover in IDDM patients

To determine whether the responses of muscle protein metabolism to insulin and amino acids in patients with insulin-dependent diabetes mellitus (IDDM) were different from those in nondiabetic subjects, leg tissue kinetics of [15N]phenylalanine and [1-13C]leucine and its metabolites were measured in eight insulin-withdrawn IDDM patients and eight nondiabetic subjects during basal insulinemia and during infusion of insulin (0.29 nmol.min-1.m-2). The diabetic patients were studied in the absence of amino acids, and both groups were studied during infusion of a mixed-amino acid solution (AA). In the diabetic patients, insulin alone and combined with additional AA reduced leg tissue phenylalanine release by 42 and 41%, respectively (both P less than 0.05), but uptake was unchanged. Leg tissue leucine oxidation was unchanged by insulin alone but was increased (P = 0.012) fourfold during insulin infusion with additional AA. In the nondiabetic subjects, insulin with AA infusion increased leg tissue phenylalanine uptake (45.7 +/- 7.5 to 73.1 +/- 7.3 nmol.min-1.100 g-1, P less than 0.01). Insulin-stimulated glucose uptake in the diabetic patients (1.60 +/- 0.28 mumol.min-1.100 g-1, P = 0.04). These results suggest that, in IDDM patients, 1) infusion of insulin fails to stimulate muscle protein synthesis even when combined with a substantially increased provision of AA, and 2) compared with nondiabetic subjects, muscle protein synthesis as well as glucose uptake exhibit blunted responses to insulin.

Neuroanatomic differences between dyslexic and normal readers on magnetic resonance imaging scans

The areas of six bilateral brain segments in the right and left hemispheres, on a horizontal brain section, and the area of subdivisions of the corpus callosum, on a midsagittal brain section, were measured on magnetic resonance images obtained from 21 dyslexic and 29 control subjects. In the entire group, the frontal half of the horizontal brain section showed asymmetry, with the right side being larger, whereas posteriorly only the occipital polar segment was asymmetrical, with the left side being larger. Dyslexic subjects exhibited asymmetry, with the right side greater than the left side, in contrast to the relatively symmetrical pattern that is normally observed in the midposterior segment that corresponds to the angular gyrus. In the corpus callosum, dyslexic subjects were found to have a larger splenium than nondyslexic subjects, and dyslexic female subjects were found to have a larger splenium than dyslexic male subjects. Because transcallosal pathways connecting the left and right angular gyrus regions traverse through the splenium of the corpus callosum, the above findings in dyslexic subjects suggest an anatomic abnormality in the angular gyrus region.

Very mild Alzheimer's disease: informant-based clinical, psychometric, and pathologic distinction from normal aging

We compare clinicopathologic data from 10 subjects identified in the very mild stage of senile dementia of the Alzheimer type with findings from similar studies in four cognitively normal subjects. We based the diagnosis of very mild dementia in the 10 subjects on informant reports and the judgment of experienced clinicians. Deficits of some psychometric measures of memory, language, and speeded psychomotor performance were observed for these subjects. The histologic markers of Alzheimer's disease, including neurofibrillary tangles and both the "diffuse" and classic subtypes of senile plaques, were present in the neocortex in all 10 subjects but essentially were absent in the four controls. These findings indicate that even "questionable" dementia can be diagnostic for Alzheimer's disease. Furthermore, because truly normal aging may be unaccompanied by neocortical senile plaques and neurofibrillary tangles, the presence of these lesions should suggest the possibility of clinically undetected Alzheimer's disease.

The Consortium to Establish a Registry for Alzheimer's Disease (CERAD). Part II. Standardization of the neuropathologic assessment of Alzheimer's disease

The Neuropathology Task Force of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) has developed a practical and standardized neuropathology protocol for the postmortem assessment of dementia and control subjects. The protocol provides neuropathologic definitions of such terms as "definite Alzheimer's disease" (AD), "probable AD," "possible AD," and "normal brain" to indicate levels of diagnostic certainty, reduce subjective interpretation, and assure common language. To pretest the protocol, neuropathologists from 15 participating centers entered information on autopsy brains from 142 demented patients clinically diagnosed as probable AD and on eight nondemented patients. Eighty-four percent of the dementia cases fulfilled CERAD neuropathologic criteria for definite AD. As increasingly large numbers of prospectively studied dementia and control subjects are autopsied, the CERAD neuropathology protocol will help to refine diagnostic criteria, assess overlapping pathology, and lead to a better understanding of early subclinical changes of AD and normal aging.

Cardiac microcirculatory effects of beta-adrenergic blockade during sympathetic stimulation

The effects of beta-adrenergic blockade on cardiac transcapillary exchange were examined at rest and during sympathetic stimulation. Multiple indicator dilution experiments were carried out in closed-chest anesthetized dogs at rest and during carotid occlusion, either under basal conditions or after beta-adrenergic blockade with alprenolol. beta-Adrenergic blockade at rest had no effect on coronary flow or transcapillary exchange in comparison with the control situation, but it abolished the increase in coronary flow and in the permeability/surface area product for labeled sucrose produced by carotid occlusion. High coronary resistance values in beta-blocked animals with carotid occlusion were associated with a high degree of heterogeneity in capillary transit times, but the overall relation between coronary flow and the capillary permeability/surface area product was unchanged. The findings indicate that beta-blockade increases coronary resistance during sympathetic stimulation and, simultaneously, decreases the coronary blood flow and capillary permeability/surface area product while increasing the heterogeneity of capillary transit times.

Increased sarcolemmal Ca2+ transport activity in skeletal muscle of diabetic rats

Sarcolemmal membranes were isolated from skeletal muscle by a sucrose density gradient method from rats with diabetes induced by a streptozotocin injection (65 mg/kg iv). The activities of Na(+)-dependent Ca2+ uptake and Ca2(+)-stimulated adenosine-triphosphatase (ATPase) in the sarcolemmal fraction from diabetic rats was higher than those from the control animals. These changes were apparent at various times of incubation (1-10 min) as well as at different concentrations of free Ca2+ (10(-7) to 10(-5) M) and developed during the third and/or fourth weeks after streptozotocin injection. ATP-dependent Ca2+ uptake in the sarcolemmal vesicles was also increased at 28 and 56 days after inducing diabetes. Treatment of diabetic animals with insulin for 14 days reversed the changes in Ca2+ transport activities toward the control levels. Sarcolemmal Mg2(+)-ATPase and Na(+)-K(+)-ATPase activities remained unchanged in diabetic preparations. Furthermore, no difference in the sarcolemmal phospholipid composition and sodium dodecyl sulfate-gel electrophoretic pattern was evident between the control and experimental groups. These results indicate a higher activity of the sarcolemmal Ca2+ transport, which may be associated with hyperfunction of the skeletal muscle in diabetic rats.

Effects of DuP 753 on renal function of normotensive and spontaneously hypertensive rats

This study examined the effects of a new, orally-active, nonpeptide angiotensin II (AII) receptor antagonist, 2-n-butyl-4-chloro-5-hydroxymethyl-1-[2'-(1H-tetrazol-5-yl)biph eny l-4- yl)methyl] imidazole, DuP 753, on renal function of anesthetized, volume-expanded Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHR), and in a group of euvolemic Munich-Wistar (MW) rats. Plasma renin activities were similar and averaged 4.4 +/- 0.7 and 4.3 +/- 1.4 ng AI/mL.h, respectively, in the SHR and WKY rats. In WKY rats (n = 15), DuP 753 (2 or 10 mg/kg, intravenously) had no effect on urine flow, sodium excretion, renal blood flow (RBF), or glomerular filtration rate (GFR). Fractional excretion of lithium (FELi) rose from 32 +/- 5 to 40 +/- 4% of the filtered load and arterial pressure decreased slightly from 129 +/- 2 to 122 +/- 2 mm Hg. In SHR (n = 9), urine flow fell 24%, and FELi and RBF increased by 27% and 30%, respectively, after 2 mg/kg DuP 753, but sodium excretion, GFR, and arterial pressure were not significantly altered. A higher dose of DuP 753 (10 mg/kg; n = 8) reduced arterial pressure, urine flow, and sodium excretion in the SHR. RBF increased 34%, while GFR and FELi were not significantly altered. Similar effects were seen in SHR (n = 11), given an equivalent antihypertensive dose of captopril (20 mg/kg). In euvolemic MW rats in which plasma renin activity was elevated to 18.8 +/- 3.3 ng AI/mL.h, DuP 753 (2 mg/kg, n = 7) increased RBF, urine flow, and sodium excretion, while mean arterial pressure and GFR were unaltered.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical implications of serum levels of basement membrane components in diabetic patients with and without albuminuria

Serum levels of type IV collagen (7S-IV) and laminin P1 in 185 non-insulin-dependent diabetes mellitus patients were significantly higher than those in normal subjects. Furthermore, they were significantly elevated in relation to the excretion of urinary albumin, showing their increases even at the stage of microalbuminuria, although they were not correlated with HbA1c or age in diabetic patients. Thus, the determination of serum levels of basement membrane components, 7S-IV and laminin, could be beneficial as the early indices of diabetic microangiopathy, including diabetic nephropathy.

Clinical significance of urinary laminin P1 in diabetic patients

The urinary concentrations of laminin fragment P1 (L-P1), a major component of laminin, were determined in diabetic patients without diabetic nephropathy and healthy controls. In the control subjects, urinary L-P1 increased with age, especially over 60 years of age. A significant increase of urinary L-P1 was observed in diabetics aged less than 50 years. Neither urinary albumin nor N-acetyl-beta-D-glucosaminidase correlated to the urinary L-P1 level. We used immunohistochemistry to locate L-P1 in the cortex of human kidneys. In non-diabetic kidneys, the glomerular and tubular basement membranes, mesangium, and Bowman's capsule were stained. In the diabetic kidney, more was stained, including the mesangial expansion and the thickened capillary basement membranes.

The prevalence of Helicobacter pylori infection in the Peoples Republic of China

Meta-analysis on data from 16 (two volunteer and 14 endoscopic) studies ahs been performed to investigate the prevalence of Helicobacter pylori infection in the stomachs of individuals within the Peoples Republic of China. In this survey covering 2216 cases (89 volunteers and 2127 endoscopy patients), the incidence of H. pylori infection in 15- to 22-yr-old healthy volunteers, and in 13- to 88-yr-old symptomatic patients undergoing gastroscopy was 49.4% and 64.5%, respectively. The frequency of H. pylori infection in chronic gastritis (63.6%), gastric ulcer (71.9%), and duodenal ulcer disease (73.1%) differed significantly from that in histologically normal individuals (8.2%), confirming the relationship of H. pylori infection with those disease states. We found no significant association between H. pylori infection and symptoms.

Segmental vascular resistance in isolated perfused rat lungs. Influence of vasomotor tone and cyclooxygenase and lipoxygenase inhibition

We have determined the profile of pressures in isolated perfused lungs of adult rats and investigated the influence of vasomotor tone and cyclooxygenase and lipoxygenase inhibition on total and segmental vascular resistance. We isolated and blood-perfused lungs of 30 rats (480 +/- 21 g). Group 1 (n = 7) was untreated, group 2 (n = 8) was paralyzed with papaverine, group 3 (n = 11) was treated with indomethacin, and group 4 (n = 4) was treated with indomethacin and U60257, a putative lipoxygenase inhibitor. Blood flow was adjusted initially to raise pulmonary artery pressure to approximately 15 cm H2O and then held constant. Airway and left atrial pressures were held constant at 7 and 8 cm H2O, respectively (zone 3 conditions). In all lungs, we measured pressures in subpleural 20-50-microns-diameter arterioles and venules using the micropuncture servonull technique. Thus, the pulmonary circulation was partitioned into three segments: arteries, microvessels, and veins. In group 1 lungs, arteries presented the largest fractional resistance to flow at 46% of total resistance, with microvessels and veins contributing 34% and 20%, respectively. In group 2 lungs that had no vasomotor tone, total vascular resistance was approximately 27% lower than in group 1 lungs, mainly due to a lower resistance in veins. In indomethacin-treated lungs (group 3) and indomethacin and U60257-treated lungs (group 4), total and segmental vascular resistance was not significantly different from untreated lungs (group 1). We conclude that in isolated perfused rat lungs, arteries are the predominant site of resistance to blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)

Complement activation by cigarette smoke

Lung disease secondary to cigarette smoking is associated with an influx of neutrophils and monocytes into the lower respiratory tract. To determine whether cigarette smoke can generate chemotactic activity, human serum was exposed to cigarette smoke and evaluated for neutrophil and monocyte chemotactic activity. Serum exposed to cigarette smoke attracted significantly greater numbers of neutrophils and monocytes compared with normal human serum exposed to air (P less than 0.01, both comparisons). The increase in chemotactic activity was partially attenuated by EDTA but not by ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) and MgCl2 (P greater than 0.05, both comparisons), suggesting activation of the alternate complement pathway. To evaluate the capacity of cigarette smoke to activate the complement system, smoke-exposed serum was evaluated for cleavage of properdin factor B and C3 using immunoelectrophoresis and for C5a using a radioimmunoassay. Cleavage of properdin factor B and C3 was observed in the smoke-exposed serum and C5a was detected in the smoke-exposed serum (112 +/- 31 ng/ml). These data suggest that complement activation may play a role in directing the influx of neutrophils and monocytes into the lungs of cigarette smokers.

Reduced glycogen synthase activity in skeletal muscle from obese patients with and without type 2 (non-insulin-dependent) diabetes mellitus

In order to evaluate the importance of a defect in insulin mediated non-oxidative glucose metabolism and glycogen synthase activity in skeletal muscles in obese subjects with and without Type 2 (non-insulin-dependent) diabetes mellitus we studied: 10 lean and 10 obese control subjects and 12 obese diabetic patients using the euglycaemic hyperinsulinaemic clamp technique (basal, 20 mU.(m2)-1.min-1, 80 mU.(m2)-1.min-1) in combination with indirect calorimetry. Muscle biopsies were taken from m. vastus lateralis at each insulin level. We found that non-oxidative glucose metabolism could be stimulated by insulin in all three groups (p less than 0.01). The values obtained at the highest insulin levels (around 140 microU/ml) were lower in both obese groups compared to the lean control subjects (118 +/- 21, 185 +/- 31, 249 +/- 14 mg.(m2)-1.min-1 (p less than 0.01]. Insulin stimulation of the glycogen synthase activity at a glucose-6-phosphate concentration of 0.1 mmol/l was absent in both obese groups, while activities increased significantly in the lean control subjects (19.6 +/- 4.2% to 45.6 +/- 6.8%, p less than 0.01). Glycogen synthase activities at the highest insulin concentrations only differed significantly between lean control subjects and obese diabetic patients (45 +/- 7% and 31 +/- 5%, p less than 0.05). We conclude that insulin resistance in peripheral tissues in obese subjects with and without Type 2 diabetes may be partly explained by a reduced insulin mediated non-oxidative glucose metabolism and that this abnormality might be due to an absent insulin stimulation of glycogen synthase in skeletal muscles. This enzyme defect is correlated to obesity itself.

[A study of weight and weight/birth at birth by gestational week]

A study of 35,919 live neonates was conducted from 1976 to 1987 (excluding 1980) at a teaching hospital in Central Taiwan. Our goal was to determine the proportions of low birth weight (LBW) and very low birth weight (VLBW) and birth weight/birth length ratios by gestational week. The results showed that LBW and VLBW neonates were 6.3% and 1.1%, respectively. In LBW neonates groups, there was a rapid decline after the 33rd gestational week, then as low as 6.9% by the 38th gestational week. After the 28th gestational week, there was a rapid decline in VLBW proportion, then a further decline to 9.3% at the 32nd gestational week. Birth weight/birth length ratios were 2.94 and 6.25 at the 28th and 39th gestational weeks, respectively. There were no differences in birth weight/birth length ratios between male and female babies. Based on the above findings, we tried to set a norm from birth weight/birth length ratios by gestational week.

Effect of cyclosporine on hepatic energy status and on fructose metabolism after portacaval shunt in dog as monitored by phosphorus-31 nuclear magnetic resonance spectroscopy in vivo

The effect of cyclosporin A on the hepatic energy status and intracellular pH of the liver and its response to a fructose challenge has been investigated using in vivo phosphorus-31 nuclear magnetic resonance spectroscopy in dogs. Three experimental groups were studied: (a) control dogs (n = 5), (b) dogs 4 days after the creation of an end-to-side portacaval shunt (n = 5), and (c) dogs 4 days after portacaval shunt and continuous infusion of cyclosporin A (4 mg/kg/day) by way of the left portal vein (portacaval shunt plus cyclosporin A, n = 5). The phosphorus-31 nuclear magnetic resonance spectra were obtained at 81 MHz using a Bruker BIOSPEC II 4.7-tesla nuclear magnetic resonance system equipped with a 40-cm horizontal bore superconducting solenoid. The phosphomonoesters (p less than 0.01), inorganic phosphate and ATP levels (p less than 0.05) were decreased significantly in portacaval shunt-treated and in portacaval shunt-plus-cyclosporin A-treated dogs compared with unshunted control dogs. After a fructose challenge (750 mg/kg body wt, intravenously), fructose-1-phosphate metabolism was reduced in portacaval shunt-treated dogs compared with either the normal or portacaval shunt-plus-cyclosporin A-treated dogs (p less than 0.05). Both portacaval shunt- and portacaval shunt-plus-cyclosporin A-treated dogs demonstrated a reduced decline in ATP levels after fructose infusion when compared with the controls (p less than 0.05). Immediately after the fructose challenge, the intracellular pH decreased from 7.30 +/- 0.03 to 7.00 +/- 0.05 in all animals (p less than 0.01) and then gradually returned to normal over 60 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Cingulin, a specific protein component of tight junctions, is expressed in normal and neoplastic human epithelial tissues

Cingulin is a 140-kd protein localized on the cytoplasmic face of avian tight junctions. The expression of cingulin in human normal and neoplastic colonic tissue has been investigated with an antiserum against chicken cingulin. Human cingulin shares its apparent molecular mass and localization with avian cingulin. In normal colonic epithelium, villous adenomas, and differentiated adenocarcinomas, cingulin staining is observed in the junctional region of the polarized cells lining the surface, the crypts, and the glandular lumina. In poorly differentiated adenocarcinomas, labeling also is observed at the interface between cancer tissue and stroma, or in clumps of malignant cells, forming a pattern that highlights the presence of small, compressed lumina. The cingulin content of four adenocarcinomas, estimated by immunoblotting and densitometry, was higher than that of the normal tissue (150% to 230%). Cingulin was detected in a metastasis from a colon adenocarcinoma but not in nonepithelial tissues and neoplasias, suggesting that cingulin may be a useful marker in the characterization of colonic and probably other epithelial neoplasias.

Serum chemistry of the wild caught karyotype I night monkey (Aotus nancymai)

Serum samples from 254 wild-caught Aotus nancymai were analyzed to determine the reference intervals for serum chemistry parameters in this species. Findings show values of total bilirubin, creatinine, alkaline phosphatase, alanine aminotransferase, urea nitrogen, serum albumin, and gamma glutamic transpeptidase having a non-normal distribution. Based on nonparametric tests, significant differences between male and female values were observed for cholesterol, serum calcium, and gamma glutamic transpeptidase. Males were significantly heavier than females. The reference intervals presented were estimated by the nonparametric percentile method.

Elevated endogenous Na-K-ATPase inhibitor activity in hypertensive diabetic patients with a family history of hypertension

Digitalis-like substance (DLS) was measured by Na-K-ATPase inhibitor (ATPI) activity and digitalis-like immunoreactivity (DLI) in 100 patients with type II diabetes. Hypertensive diabetic patients with a positive family history for hypertension had high ATPI levels compared with those patients with a negative family history for the disease. DLI level did not differ between groups. There was no significant difference in ATPI and DLI levels among three groups based on level of urinary albumin excretion. These data suggest that a circulating factor (or circulating factors) determined by ATPI may be linked with genetic factors in the development of hypertension, but not to the development of diabetic nephropathy.

Regulation by progesterone of the high-affinity state of myometrial beta-adrenergic receptor and of adenylate cyclase activity in the pregnant rat

The effects of pregnancy or progesterone dominance on the beta-adrenergic responsiveness of the uterus were studied in myometrial membranes from mid- and late-pregnant rats (day 15 and on the 16th h of day 22 of pregnancy respectively) or 24 h after administration of progesterone. Levels of the high (RH)- and low (RL)-affinity states of the beta-adrenergic receptor were determined by competition experiments between 125I-labelled cyanopindolol binding and the selective beta-agonist isoproterenol. The ratio KL/KH (respective dissociation constants) was determined since it also reflects the degree of formation of the high-affinity state of the beta-adrenergic receptor. From day 15 to the 10th h of day 22 of pregnancy, two distinct affinity states were apparent: 80-55% RH (KH = 0.31-0.21 microM) and 45-20% RL (KL = 14-5 microM) with a ratio of KL/KH of 55-34. In the last 6 h before birth, beta-adrenergic receptors underwent uncoupling which was paralleled by decreased responsiveness of myometrial adenylate cyclase to isoproterenol (maximum velocity (Vmax) = 17 +/- 3 vs 44 +/- 3 fmol cyclic AMP/10 min per mg protein on day 15). At this stage of pregnancy, previous exposure to progesterone resulted in a 1.8-fold increase in 125I-labelled cyanopindolol-binding sites (Bmax) and the reappearance of the high-affinity state (67% RH, KH = 0.19 +/- 0.04 (S.E.M.) microM, ratio KL/KH = 81.1 +/- 16.9).(ABSTRACT TRUNCATED AT 250 WORDS)

Dissociation of tubular cell detachment and tubular cell death in clinical and experimental "acute tubular necrosis"

"Acute tubular necrosis" in humans is often characterized histologically by tubular cell loss and nonreplacement rather than by frank cellular necrosis. It has been assumed that tubular cells detach from the tubular basement membrane after the occurrence of irreversible cell injury and/or cell death. We examined voided urine from patients with native kidney and transplant kidney "acute tubular necrosis" and found significant tubular cell shedding with up to 100% viability of voided tubular cells, as determined by exclusion of trypan blue. Histochemical stains for the brush border enzyme gamma-glutamyl transpeptidase and electron microscopy of cell isolates demonstrated that 30 to 100% of the voided cells were of proximal tubule origin. Moreover, epithelial cell cultures were readily established from noncontaminated voided specimens, and more than 80% of the cells in monolayers expressed gamma-glutamyl transpeptidase activity in vitro. Electron microscopy of cell monolayers confirmed proximal tubular differentiation in the majority of cells in the monolayer, with the remainder having an appearance more consistent with distal origin. In rabbit models of acute ischemic (pedicle clamp) and toxic (HgCl2 and glycerol-induced) injury, tubular cell shedding was also significant, with a mean of 25 to 30% of the voided cells viable. Epithelial cells were successfully cultured and passed from animals with ischemic renal injury. In vitro studies were carried out in cultured human proximal tubular cells to assess suitability of this system for more direct study of the phenomenon of cell detachment in response to injury. We found significant changes in cell shape in response to exposure to anoxia and HgCl2 in these cultures, with extensive cell rounding and retraction at times when cell viability remained high. This in vitro system could prove useful for defining mechanisms of renal tubular cell detachment in response to injury and for examining potential interventions to prevent epithelial disruption and loss of functional integrity. These strategies may ultimately have clinical relevance in patients with "acute tubular necrosis".

Autosomal recessive chronic granulomatous disease caused by deletion at a dinucleotide repeat

Chronic granulomatous disease (CGD) is a rare inherited condition rendering neutrophils incapable of killing invading pathogens. This condition is due to the failure of a multicomponent microbicidal oxidase that normally yields a low-midpoint-potential b cytochrome (cytochrome b245). Although defects in the X chromosome-linked cytochrome account for the majority of CGD patients, as many as 30% of CGD cases are due to an autosomal recessive disease. Of these, greater than 90% have been shown to be defective in the synthesis of a 47-kDa cytosolic component of the oxidase. We demonstrate here in three unrelated cases of autosomal recessive CGD that the identical underlying molecular lesion is a dinucleotide deletion at a GTGT tandem repeat, corresponding to the acceptor site of the first intron-exon junction. Slippage of the DNA duplex at this site may contribute to the high frequency of defects in this gene.

Thigh bleeding time as a valid indicator of hemostatic competency during surgical treatment of patients with advanced renal disease

We compared the usefulness of the modified Ivy bleeding time performed in the forearm (arm bleeding time) with that performed in the thigh (thigh bleeding time) as an indicator of hemostatic competence during surgical treatment in 16 patients with chronic renal failure. In 22 normal adults, the arm bleeding time (mean plus or minus standard deviation, 6.6 +/- 1.4 minutes) was significantly longer than the value in the thigh (mean plus or minus standard deviation, 4.1 +/- 1.3 minutes) (p less than 0.001), and there was no correlation between arm and thigh bleeding time. Preoperatively, the arm bleeding time in patients with renal disease was markedly prolonged (greater than 20 minutes) in 15 patients and slightly prolonged in one patient. There was no abnormal perioperative bleeding in 13 patients whose preoperative thigh bleeding time was seven minutes or less. Prolonged and excessive perioperative bleeding was observed in three patients whose thigh bleeding time was 8.0, 9.5 and 26.5 minutes. These findings suggest that thigh bleeding time is a better indicator of competence of primary hemostasis during the operation than the arm bleeding time in patients with advanced renal failure.

Inhibition of surfactant subtype convertase in radiation model of adult respiratory distress syndrome

The accompanying paper [Am. J. Physiol. 260 (Lung Cell. Mol. Physiol. 4): L302-L310, 1991] showed that in the radiation pneumonitis model of adult respiratory distress syndrome (ARDS) there was an excess of the proximate, higher buoyant density subtypes of alveolar surfactant, and a decrease in the light buoyant density form. Because the surfactant subtypes normally evolve from the former to the latter a delay in the alveolar metabolism of surfactant could explain this disproportion. Three possible mechanisms of a delay in surfactant metabolism in radiation pneumonitis were explored using an in vitro model of surfactant subtype metabolism called "cycling". The first was that the surfactant of mice with radiation pneumonitis was intrinsically less capable of conversion to the light subtype. It was found, however, that the proximate forms of surfactant of mice with radiation pneumonitis were as capable of generating light subtype as those of control mice. The second was that there was a deficit in the serine protease activity, called "convertase", that mediates the conversion. But it was found that lungs of mice with radiation pneumonitis released convertase activity to the same extent as control lungs. The third was that an inhibitor of convertase activity was present in the alveoli. It was found that the alveolar lavage fluid of mice with radiation pneumonitis inhibited the conversion of exogenous surfactant by exogenous convertase. Moreover, it contained an 18-fold excess of antiprotease activity. The present data are interpreted as suggesting that an inhibitor in the alveolar space is responsible for the delay in surfactant subtype metabolism in radiation pneumonitis, resulting in the disproportion of surfactant subtypes in radiation pneumonitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of streptozotocin-induced diabetes on acetylcholine metabolism in rat brain

The main objective of this study was to determine whether uncontrolled hyperglycemia, as a consequence of diabetes, altered the metabolism of acetylcholine (ACh) in rat brain. To accomplish this, rats received injections of streptozotocin (STZ, 60 mg/kg, i.v.) or vehicle, and were maintained for up to 7 weeks after the injections. Various indices of ACh metabolism were determined in striatum and hippocampus, two brain regions densely innervated by cholinergic neurons. STZ induced diabetes in 96% of the rats injected, as evidenced by glucose spillage into the urine within 48 hours. Serum glucose levels increased to 326% of control values by 1 week and remained at this level for the duration of the study. The steady-state concentrations of ACh and choline, determined in brain tissue from animals killed by head-focused microwave irradiation, did not differ between the control and STZ-injected groups. However, the synthesis and release of neurotransmitter by striatal slices, measured in vitro, decreased in a time-dependent manner. Although the basal release of ACh was unaltered at 1 week, neurotransmitter release decreased significantly by 21% at 5 weeks and by 26% at 7 weeks. The release of ACh evoked by incubation with 35 mM KCl was inhibited significantly by 20% at all time points studied. ACh synthesis by slices incubated under basal conditions decreased by 13% and 27% at 5- and 7-weeks, respectively, the latter significantly less than controls. Synthesis by striatal slices incubated with 35 mM KCl was inhibited by 17% at 7 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone mineral density measured by dual-energy X-ray absorptiometry in healthy Finnish women

A cross-sectional study of 351 healthy Finnish women aged 20-76 years was done to establish reference values of bone mineral density (BMD) using dual-energy X-ray absorptiometry (DEXA). The effects of age and of several physical and lifestyle factors on BMD of the lumbar spine and proximal femur (femoral neck, trochanter, and Ward's triangle area) were investigated. Altogether 58 women were excluded from the final analysis due to significant spinal osteoarthritis or other diseases or drugs known to influence calcium or bone metabolism. The precision of the method was 0.9, 1.2, 2.7, and 2.4% in the lumbar, femoral neck, Ward's triangle and trochanter area, respectively. Lumbar BMD was increased by 30% (P less than 0.001) in 15 patients with osteoarthritis (21% of women 50 years or older), but it was apparently unaffected in 5 cases with aortic calcification. Except for the trochanter area, BMD diminished along with age, and this was significant after the menopause. The peak of mean BMD was observed at the age of 31-35 years in the spine and at the age of 20-25 years in the femoral neck and Ward's triangle. BMD was in a positive relationship to weight both in premenopausal and postmenopausal women and to the use of oral contraceptives in premenopausal women and to that of estrogen replacement therapy in postmenopausal women. Labors and pregnancies had a weak positive effect on BMD in premenopausal women. As compared with nonusers premenopausal women who had used alcohol showed a slightly decreased BMD of Ward's triangle. In postmenopausal women there was a positive correlation between alcohol intake and BMD.

Regulation of expression of M, B, and mitochondrial creatine kinase mRNAs in the left ventricle after pressure overload in rats

Pressure overload of the left ventricle induces synthesis of creatine kinase isoenzymes. To determine whether this response is associated with an altered pattern of creatine kinase gene expression, we induced arterial hypertension in rats by suprarenal aortic banding. After 4 days, left ventricular myocardium from hypertensive (n = 7) and normotensive, sham-operated (n = 5) rats was analyzed for isoenzyme activities by chromatography; M and B creatine kinase subunit protein by Western blot; and M, B, and mitochondrial creatine kinase mRNA by Northern blot. Although total creatine kinase activity increased in hypertensive (1,096 +/- 214 IU/g left ventricle) compared with normotensive rats (648 +/- 81 IU/g left ventricle, p less than 0.01), the relative proportions of the cytoplasmic and mitochondrial isoenzymes did not change. The mass of M and B subunits increased 1.9- and 2.7-fold, respectively, in hypertensive compared with control rats. Similarly, the mRNA for M and B subunits as well as mitochondrial creatine kinase increased 2.6-, 1.6-, and 1.8-fold, respectively, in hypertensive rats compared with control rats. Thus, increased energy requirements in acute pressure overload are met by generalized induction of creatine kinase mRNA and subunit protein and not by an isoenzyme switch.

Can concomitant restriction be detected in adult men with airflow obstruction?

A reduction in lung volume is used to diagnose physiologic restriction in the pulmonary function tests of patients with lung disease. Airflow obstruction is commonly associated with hyperinflation of static lung volume. Because restriction and obstruction exert opposite effects on lung volumes, we questioned whether the lack of hyperinflation of static lung volumes could indicate the presence of concomitant restriction in patients with airflow obstructive ventilatory defects. To assess this, we evaluated by pulmonary function tests and chest roentgenograms of 58 patients with airflow obstruction (group 1), 18 of whom then sustained various types of resection for lung cancer (group 2) as a type of superimposed restriction. We selected 80 percent of predicted as the lower limit of "normal" frequently used by clinical pulmonary function laboratories. Despite a statistically significant decrease in total lung capacity (p less than 0.05) for the postpneumonectomy patients, when the static lung volume measurements of the patients with resection were evaluated, no one lung volume showed a consistent reduction sufficient to detect the superimposed restriction in all these patients. Using 80 percent of predicted as "normal," 61 percent of our patients with airflow obstruction and superimposed restriction would have been missed. We conclude that it is clinically difficult, based on only static lung volume measurements alone, to detect restriction superimposed on the hyperinflation of airflow obstruction unless these lung volumes are reduced to below accepted "normal" limits.

Chronic hyperglycemia increases the density of glucose transporters in human erythrocyte membranes

We investigated the effect of chronic hyperglycemia on glucose transporters in erythrocytes of subjects with and without diabetes mellitus. We found a 22% increase in D-glucose-displaceable cytochalasin-B binding in erythrocyte membranes of diabetic subjects over those of controls (311 +/- 13 vs. 254 +/- 8 pmol/mg protein; P less than 0.001). This increased binding was due to a higher density of binding sites without a significant change in binding affinity. Cytochalasin-B binding to erythrocyte membrane correlated positively with both erythrocyte glycohemoglobin and serum glucose levels, but not with plasma C-peptide levels. The data are compatible with up-regulation of glucose transporters in the erythrocytes of subjects with chronic hyperglycemia. We suspect that this is brought about by increased synthesis and membrane incorporation of the glucose transporter during erythropoiesis.

Voltage dependence of desensitization to carbamylcholine in frog muscle fibers reverses in low-calcium solutions

1. The effect of reduction in external Ca concentration on the voltage dependence of desensitization to carbamylcholine was studied in frog muscle fibers to determine whether local increase in cytosolic free Ca2+ from inward movement through agonist-activated receptor channels is a factor producing increased desensitization rate, as has been proposed. A critical feature is whether or not the relation of desensitization rate with voltage decreases in a regular manner as potential is increased to levels above ECa. 2. A conventional two-electrode voltage clamp procedure was used for voltage control of the postjunctional membrane of K-depolarized muscle fibers, and a standard 1-mM solution of carbamylcholine was applied to voltage-clamped endplates by local superperfusion from a micropipette. Measurements of average sarcomere length were also made in separate experiments to detect persistent raised levels of internal Ca2+ in the high-K test media. 3. In high-K test solutions containing 1.8 mM Ca, desensitization rate decreased in a regular monotonic relation with increase in potential through the range from -40 to +30 mV, giving an exponential voltage sensitivity factor of 0.016 mV-1. 4. By contrast, desensitization onset rate in high-K test media containing Ca ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (CaEGTA) buffer (calculated free Ca2+ = 61 nM) showed a nonmonotonic, reversing relation with potential characterized by a decrease in rate between -40 and -20 mV and an increase of rate with increase in potential from -20 to +30 mV.(ABSTRACT TRUNCATED AT 250 WORDS)

The induction of premature luteolysis in normal women--follicular phase luteinizing hormone secretion and corpus luteum function in the subsequent cycle

Women with luteal phase deficiency have been shown to have an increased frequency of luteinizing hormone pulses in the early follicular phase of the menstrual cycle. Because progesterone is known to modulate luteinizing hormone secretion, it has been hypothesized that the decreased progesterone secretion in a previous luteal phase deficiency cycle could lead to the abnormal luteinizing hormone secretory pattern in the ensuing early follicular phase. With the possibility that the higher luteinizing hormone pulse frequency might lead to another deficient luteal phase, it becomes conceivable that luteal phase deficiency could be self-perpetuating. To test this hypothesis, luteal phase deficiency was induced in six normal women by decreasing luteinizing hormone support of the corpus luteum with a gonadotropin-releasing hormone antagonist Nal-Glu, administered twice daily beginning in the midluteal phase after a control cycle. During the antagonist-treated luteal phase, each subject met the predetermined criteria for induced luteal phase deficiency: a 33% or greater decrease in integrated progesterone from the control cycle and an integrated progesterone level less than 100 ng/ml per day. Luteinizing hormone secretion patterns were determined by frequent blood sampling performed every 10 minutes for 12 hours in the early follicular phase of the control cycle and the cycle after antagonist administration. Daily luteal progesterone levels were measured in the control, treatment, and posttreatment cycles. Each volunteer served as her own control. Standard parameters were compared between the control and posttreatment pulse studies in the early follicular phase: (1) luteinizing hormone pulse frequency was 9.5 +/- 1.0 vs 10.0 +/- 0.9 pulses/12 hours, control vs posttreatment, respectively, p = 0.5; (2) luteinizing hormone pulse amplitude was 11.0 +/- 1.3 vs 12.0 +/- 2.2 ng/ml, p = 0.6; and (3) luteinizing hormone mean level was 19.4 +/- 2.3 vs 22.2 +/- 3.3 ng/ml, p = 0.1. Corpus luteum function was also compared between the control and posttreatment cycles. Luteal phase length was 13.7 +/- 0.6 vs 12.7 +/- 0.6 days, p = 0.08. Integrated progesterone values were 136.9 +/- 12.9 vs 130.5 +/- 11.3 ng/ml per day, p = 0.5. Therefore no discernible abnormalities in early follicular luteinizing hormone secretions or corpus luteum secretion of progesterone occurred after an induced luteal phase deficiency cycle.(ABSTRACT TRUNCATED AT 400 WORDS)

Compensatory changes in thyroid blood flow are only partially mediated by thyrotropin

It has been shown that the compensatory growth of the thyroid gland and the compensatory increase in hormone secretion that occur after hemithyroidectomy are preceded by a dramatic increase in thyroid blood flow (BF). These alterations in the thyroid remnant may be due to the concomitant increase in plasma thyrotropin (TSH) concentrations. It has been suggested, however, that the compensatory thyroid growth may also involve a neural reflex. In this study we have investigated the role of TSH in mediating the compensatory alterations in thyroid BF and mass after subtotal thyroidectomy. Male Sprague-Dawley rats were anesthetized with ether for surgical or sham hemithyroidectomy. One-half of the hemithyroidectomized rats (HTX) received no further treatment; in the other one-half of the HTX rats (Clamp), plasma TSH levels were maintained at levels comparable with those in sham-operated animals by initiating constant thyroid hormone replacement beginning at the time of hemithyroidectomy. Plasma samples for TSH, 3,5,3'-triiodothyronine, and thyroxine radioimmunoassays were obtained 2, 7, 14, and 21 days after surgery. Thyroid BF was determined at 1, 2, and 3 wk after surgery by the reference sample version of the radioactive microsphere technique (141Ce, 15 microns diameter). Plasma TSH levels and thyroid lobe weight were significantly elevated in HTX rats but not in Clamp rats. Thyroid BF was markedly increased in HTX rats. Thyroid BF was also significantly increased in Clamp rats despite the suppression of the rise in plasma TSH concentration, but this increase was less than that in HTX rats. Neither hemithyroidectomy nor Clamp treatments had any effect on arterial blood pressure or BF to other tissues (e.g., kidney).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine and hemodynamic alterations in cirrhotic rats

This study evaluated the hypothesis that adenosine may participate in the hemodynamic alterations observed in conscious unrestrained cirrhotic rats. In sham-operated rats, adenosine (20 micrograms.100 g body wt-1.min-1 iv) induced hyperdynamic circulation and significantly increased portal pressure, mimicking the hemodynamic changes observed in cirrhosis. Although adenosine significantly increased hyperdynamic circulation and portal pressure in cirrhotic rats, these changes were significantly less marked than in sham-operated rats. 8-Phenyltheophylline (20 micrograms.100 g body wt-1.min-1 iv), a specific and potent adenosine antagonist, significantly decreased portal tributary blood flow in sham-operated rats (-18.0 +/- 5.6%) but did not have a significant effect in cirrhotic rats. The limited effect of 8-phenyltheophylline was not due to an insufficient dose, since the dose administered antagonized the hemodynamic effect of exogenous adenosine up to 40 micrograms.100 g body wt-1.min-1. We conclude that in certain circumstances, although adenosine may aggravate the hyperdynamic circulation, in normal conditions, the hemodynamic alterations observed in cirrhotic rats are not mediated by adenosine.

Increase in serum and bile cholesterol and HMG-CoA reductase by lovastatin in rats

Lovastatin, a competitive inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, is effective in the treatment of hypercholesterolemic patients and is currently being evaluated as a potential agent for dissolving gallstones. We therefore evaluated its effect on cholesterol metabolism in a rat model. A low-cholesterol diet containing 0.1% lovastatin was fed 15 h and 7 and 21 days. Microsomal HMG-CoA reductase activity, hepatic cholesterol synthesis, blood cholesterol, and biliary lipid output were determined and compared with control rats. Hepatic cholesterol synthesis increased ninefold after 7 days and levels of HMG-CoA reductase activity sevenfold. Biliary cholesterol excretion maximally increased fourfold. Biliary lipid output was still elevated after 21 days of treatment (cholesterol 3-fold and phospholipid 2-fold, P less than 0.01). Bile salt output did not change. Augmented responses to lovastatin were present but less on the high-cholesterol diet. The data are consistent with the hypothesis that lovastatin increases HMG-CoA reductase activity through a feedback mechanism that promoted increased cholesterol synthesis, biliary lipid secretion, and elevated blood cholesterol. There was an apparent coupling of biliary cholesterol output with phospholipids but not with bile salts. Although lovastatin also increased microsomal HMG-CoA reductase activity in humans, cholesterol synthesis is not stimulated but is inhibited. This may be explained by higher permeability of the microsomal membranes for lovastatin. Thus the effect of HMG-CoA reductase inhibitors on cholesterol synthesis in different species should then depend on the properties of microsomal membranes.

Sequential release of eicosanoids during endotoxin-induced shock in anesthetized pigs

The release of eicosanoids during endotoxin shock was investigated in anesthetized pigs receiving 5 micrograms/kg Escherichia coli lipopolysaccharide (LPS) over 60 min into the superior mesenteric artery. TXB2, 6-keto PGF1 alpha and LTB4 concentrations in blood obtained from the superior mesenteric vein (SMV), right ventricle (RV) and aorta, during LPS infusion and an additional period of 2 h, were assessed along with hemodynamic variables, blood gases and pH and laboratory parameters. Half of the animals died within 30 min after termination of LPS infusion (non-survivors, n = 8), while the other half survived the experimental period of 3 h, though in a shock state (survivors, n = 9). The non-surviving pigs demonstrated progressively reduced cardiac output, hypotension and hypoperfusion in all organs. The surviving pigs demonstrated also a reduced cardiac output, which however was compensated by an elevated systemic vascular resistance resulting in a maintenance of arterial blood pressure. After exhausting this compensation the flow to non-vital organs increased and consequently arterial blood pressure was reduced resulting in hypoperfusion. In survivors a marked, though, transient increase was measured in concentrations of TXB2 and 6-keto PGF1 alpha level. A significant increase was measured in plasma concentration of LTB4 in SMV without any elevation in RV and aorta. LTB4 production started when prostanoid release had decreased. In contrast to survivors, no changes could be observed in eicosanoid release for non-survivors. A correlation was observed between systemic vascular resistance and TXB2 to 6-keto PGF1 alpha ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

[Electron microscopy findings in human spermatozoa with flagellar defects]

Spermatozoal motility disorders must be interpreted with reference to whether the flagella are intact or impaired. A new classification of alterations of midpiece and flagellum includes a shaft disturbance that is increasingly often observed and can be recognized by light microscopy. Electron microscope examinations have shown that missing or poorly developed outer dense fibres are one cause of this flagellar disorder. As suitable longitudinal sections are rarely obtained in transmission electron microscopy, the negative staining technique was used in addition for this purpose. This method was found to be most suitable for an exact analysis of the periaxonemal structures of the sperm flagellum. Consideration of this hitherto unknown flagellar disturbance is important, because various therapeutic approaches have had little success so far and patients should be referred in good time for other gynaecological or andrological treatments.