Proliferation of endothelial cells in estrogen-stimulated rat liver. A light and electron microscopic cytochemical study.

The mononuclear phagocytes (Kupffer cells) in the normal rat liver can be distinguished from the endothelial cells on the basis of their endogenous peroxidase activity in the endoplasmic reticulum and their exclusive ability to phagocytose large (0.81 mum.) latex particles. Using these cellular markers we have investigated the effects of an estrogen upon the mitotic activity and the ultrastructure of individual types of littoral cells in the rat liver. Adult female rats received a single 10-mg. injection of diethylstilbestrol, and at daily intervals up to 6 days their livers were fixed by perfusion and processed for localization of peroxidase. Mitotic figures were rare in untreated control animals, but dividing littoral cells with both positive and negative peroxidase reaction could be identified. The exclusive localization of injected latex particles in dividing peroxidase-positive cells indicated that peroxidase reaction identified the Kupffer cells not only in the interphase but also during the mitotic division. In estrogen-treated animals there was a sharp rise in the mitotic activity of littoral cells; the activity reached its peak on the 3rd day and returned to normal levels on the 6th day after the initial injection. A breakdown of the dividing cells on the basis of their peroxidase reactivity revealed that nearly the entire population of dividing cells consisted of peroxidase-negative endothelial cells. In addition, numerous hyperactive Kupffer cells containing large phagolysosomes with phagocytosed peripheral blood cells and latex particles were seen. Intermediate cell-types with cytochemical features between Kupffer cells and endothelial cells or between monocytes and Kupffer cells were not encountered. Because of the limited phagocytic capacity of hepatic endothelial cells, our observations would provide morphologic evidence in support of previous physiologic studies, indicating that estrogen treatment has little or no effect upon the particle clearing function of the reticuloendothelial system in rats. The rare but clear demonstration of dividing Kupffer cells in liver sinusoids would indicate that these cells are capable of self-replication in situ. Finally, our observations suggest that estrogens may play an important role in the pathophysiology of endothelial cells.     

The effects of fenugreek seed extract supplementation in patients with Alzheimer's disease: A randomized,double-blind,placebo-controlled trial

The aim of the current randomized control trial (RCT) study was to investigate the effects of fenugreek seed extract on memory, depression, quality of life, blood pressure, and serum malondialdehyde (MDA) and total antioxidant capacity (TAC) levels in adult AD patients. This randomized clinical trial was conducted in geriatric homes in Iran. The study participants included 82 AD patients with mild-to-moderate memory deficit. Patients in the intervention group received 5 cc of fenugreek seed extract for 4 months and subjects in the control group received a placebo. Memory, depression, quality of life, and BP levels, as well as serum MDA and TAC, were assessed before and after the intervention. There was a significant increase in serum levels of TAC (p < 0.001) and a reduction in serum MDA status (p < 0.001) after 4 months of fenugreek seed extract supplementation. In addition, increasing levels of memory (p < 0.001) and quality of life (p < 0.001), as well as reduction of depression (p = 0.002), systolic BP (p < 0.001), and diastolic BP (p < 0.001) levels were detected in the intervention group compared with baseline. Fenugreek seed extract supplementation in AD patients shows promising positive effects on memory, quality of life, BP, and selective oxidative indices levels.     

Differences in the response of Sprague-Dawley and Lewis rats to bezafibrate: The hypolipidemic effect and the induction of peroxisomal enzymes

The effects of bezafibrate administered at 10 and 50 mg/kg/day for 7 days to male Sprague-Dawley (SD) and Lewis rats were investigated in order to determine the interrelation between the changes in serum and hepatic lipid contents and activities of selected peroxisomal, microsomal and mitochondrial enzymes in the two rat strains. In both strains, bezafibrate effectively reduced serum and hepatic lipids, increased the liver weight, induced a proliferation of peroxisomes, and selectively elevated the activities of carnitine acetyltransferase and of the enzymes of the peroxisomal -oxidation system. Moreover, immunoblotting revealed that the drug specifically enhanced the concentration of only those peroxisomal enzymes involved in fatty acid -oxidation. The data obtained demonstrate that although the responses initiated by bezafibrate are qualitatively similar in both strains, they differ in their magnitude in a dose-dependent manner, with the Lewis strain exhibiting a more pronounced response than the SD rats. These results show that dose-dependent strain differences as well as the generally known species differences should be taken into account in pharmacological and toxicological evaluations of fibrates in rodents. Furthermore, generalization and extrapolation from rodent studies should be treated with great caution.     

Endogenous peroxidase in the nuclear envelope and endoplasmic reticulum of human monocytes in vitro: association with arachidonic acid metabolism

The development of peroxidase (PO) reaction in the nuclear envelope (NE) and endoplasmic reticulum (ER) of monocytes differentiating in vitro and its relationship with arachidonic acid metabolism were studied. The PO, as visualized by the diaminobenzidine (DAB) technique, appeared in the NE and ER of the majority of monocytes within 24 hours of culture, with a substantial decrease thereafter. The influence of three major groups of agents--inhibitors of PO, of prostanoids, and of protein biosynthesis--upon the development of the PO reaction was examined. When aminotriazole, a PO inhibitor, was added to the culture medium, the appearance of PO was suppressed in the monocytes. The cyclooxygenase blocker, indomethacin, however, did not influence the development of PO. Also the blockers of protein synthesis, puromycin, cycloheximide, and actinomycin D, did not affect the appearance of PO. The prostanoids released from the monocytes, ie, prostaglandin E and thromboxane B2, were determined by radioimmunoassay and showed a time sequence of secretion that corresponded to the appearance of PO in the cells: a marked increase within the first 24 hours with a substantial decrease thereafter. The presence of the PO inhibitors aminotriazole and sodium azide in the culture medium produced a suppression of prostanoid release from the monocytes comparable with that of indomethacin. The data suggest that the PO in the NE and ER of differentiating monocytes in vitro (1) is associated with arachidonic acid metabolism, and (2) is not formed by de novo protein synthesis but rather by an activation process.     

Hepatic zonation of the induction of cytochrome P450 IVA, peroxisomal lipid beta-oxidation enzymes and peroxisome proliferation in rats treated with dehydroepiandrosterone (DHEA). Evidence of distinct zonal and sex-specific differences

Dehydroepiandrosterone (DHEA) is an intermediate product in the synthesis of male and female sex hormones in the adrenal cortex of man. In livers of rats and mice DHEA increases the levels of cytochrome P450 IVA and peroxisomal beta-oxidation enzymes associated with peroxisome proliferation. Prolonged treatment of rats with DHEA induces liver tumors that are more frequent in females arising mainly in the periportal regions of the liver lobule (Metzger et al., Toxicol. Pathol. 23, 591-605, 1995). Because of paucity of information on hepatic zonation of peroxisomal response to DHEA and controversial reports on gender-specific differences of its effects the present study was undertaken using qualitative immunohistochemical and quantitative immunoelectron microscopical techniques in addition to Western blotting. Rats were treated for 24 weeks with 0.6% DHEA supplied with diet. Immunoblot analysis revealed marked induction of peroxisomal beta- oxidation enzymes, which by quantitative analysis was equally strong in male and female animals, whilst catalase and urate-oxidase were not increased. Cytochrome P450 IVA, in contrast, was induced significantly stronger in male than in female rats. Immunohistochemistry confirmed the induction of cytochrome P450 IVA showing a marked lobular gradient in female animals with strong induction in pericentral and almost no induction in periportal regions of the liver lobule. In male animals cytochrome P450 IVA was expressed more uniformly across the liver lobule. A similar sex specific zone-dependent response was observed for peroxisomes. DHEA induced in females a significant zonal gradient with marked peroxisome proliferation and a strong induction of peroxisomal hydratase/dehydrogenase in pericentral hepatocytes and a much smaller response in periportal regions. Livers of male animals, in contrast, showed a uniform peroxisomal proliferation to DHEA with only slight zonal differences. The striking homologies of the induction patterns of cytochrome P450 IVA and the peroxisome proliferation in both sexes support the notion of a functional relationship. In view of the almost exclusive periportal localization of DHEA-induced tumors in female rats in contrast to the pericentral localization of the peroxisomal proliferation shown by this study, it seems likely that other factors in addition to peroxisome proliferation may contribute to the hepatocarcinogenic effect of DHEA.      

Risk factors of thyroid abnormalities in bipolar patients receiving lithium: a case control study

Background

Lithium-induced thyroid abnormalities have been documented in many studies. They may occur despite normal plasma lithium levels. The objectives of this study were: 1) to determine possible relationship between lithium ratio, defined as erythrocyte lithium concentrations divided by plasma lithium concentrations, and thyroid abnormalities in bipolar patients receiving lithium and 2) to find other possible risk factors for developing thyroid abnormalities in the subjects.

Methods

Sixty-eight bipolar patients receiving lithium therapy were enrolled in a cross-sectional evaluation of thyroid function test and thyroid size. Patients were divided into two groups based on their thyroid function tests and thyroid sizes. Erythrocyte and plasma lithium concentrations were determined by atomic absorption spectrometry for each patient. Lithium ratio was then calculated.

Results

No significant differences were found between age, positive family history of affective disorder, plasma lithium concentration, erythrocyte lithium concentration, and lithium ratio comparing the two groups. Thyroid abnormalities was significantly higher in women than in men (p < 0.05).

Conclusions

Lithium ratio does not appear to have a predictive role for thyroidal side effects of lithium therapy. Female gender was the main risk factor. We suggest more frequent thyroid evaluation of bipolar women who are treated with lithium.

     

Derivation of decision rules to predict clinically important outcomes in acute flank pain patients

Objective

Routine CT for patients with acute flank pain has not been shown to improve patient outcomes, and it may unnecessarily expose patients to radiation and increased costs. As preliminary steps toward the development of a guideline for selective CT, we sought to determine the prevalence of clinically important outcomes in patients with acute flank pain and derive preliminary decision rules.

Evaluation of a Cornstarch-Based Ultrasound Gel Alternative for Low-Resource Settings

Background

Ultrasound is an ideal imaging modality for low-resource settings given its portability, ease of use, and wide range of applications. Commercially available ultrasound gels may be unavailable or cost prohibitive in low-resource settings.

Objective

Our aim was to investigate the quality of images obtained with an alternative ultrasound gel made from cornstarch and water in comparison with commercially available gel.

Methods

The cornstarch gel was made by heating water and cornstarch. The gel was used to obtain standard ultrasound images of the gallbladder, kidneys, bladder, heart, and neck vessels by the study investigators. Commercial gel was used as the control. Twenty-four ultrasound clips were shown to four blinded radiologists and two ultrasound-fellowship−trained emergency department physicians. They rated the images on adequacy (yes/no) and graded the images detail, resolution, and quality using a continuous 0−10 scale.

Results

A total of 144 video clips were shown to reviewers and 129 data-collection sheets were returned. There was no statistical difference in the proportion of images deemed to be of adequate quality: cornstarch-based gel = 0.97 (95% confidence interval [CI] 0.92−1.00) vs. commercially available gel = 0.85 (95% CI 0.75−0.94) (p = 0.053). The cornstarch gel was superior to commercial gel on all three image parameters: detail (p = 0.002), resolution (p = 0.018), and quality (p = 0.013).

Conclusions

In this study, a gel made from cornstarch and water was an acceptable coupling medium and provided equally adequate images as compared with commercial ultrasound gel. This inexpensive gel made from ubiquitous materials can be an acceptable alternative to commercial gel in low-resource settings.     

Microbial contamination of single- and multiple-dose vials after opening in a pulmonary teaching hospital

ObjectivesIntravenous therapy is a complex procedure usually requiring the preparation of the medication in the clinical area before administration to the patient. Breaches in aseptic technique may result in microbial contaminations of vials which is a potential cause of different avoidable infections. We aimed to investigate the prevalence and pattern of microbial contamination of single- and multiple-dose vials in the largest pulmonary teaching hospital in Iran.MethodsIn a period of 2 months, opened single- and multiple-dose vials from different wards were sampled by a pharmacist. The name of the medication, ward, labeling of the vials, the date of opening, and storing temperature were recorded for each vial. Remained contents of each vial were cultured using appropriate bacterial and fungal growth media.ResultsMicrobial contamination was identified in 11 of 205 (5.36%) of vials. The highest contamination rate was 14.28% for vials used in interventional bronchoscopy unit. The most frequent contaminated medication was insulin. Gram-positive bacteria (81.82%) were more significantly involved than gram-negative ones (9.09%) and fungi (9.09%), with the highest frequency for Staphylococcus epidermidis.ConclusionsOur data demonstrate that repeated use of vials especially if basic sterility measures are disobeyed can cause microbial contamination of administered products to the patients. Infection preventionists are responsible to train health care workers regarding aseptic techniques and apply guidelines for aseptic handling of intravenous solutions.