Toll-like receptor (TLR)7 expression in mycosis fungoides and psoriasis: a case-control study.

BACKGROUND: Toll-like receptors (TLRs) have been implicated in various dermatological diseases. TLR agonists have the capacity to potently activate the innate immune cells of patients with advanced, refractory, cutaneous T-cell lymphoma (CTCL). AIM: To detect TLR7 gene expression in mycosis fungoides (MF) (a neoplastic skin condition) and to compare it with psoriasis (an inflammatory skin condition) in an attempt to clarify the pathogenic role played by TLR7 in both conditions. METHODS: This case-control study enrolled 28 patients with MF: 30 patients with psoriasis, and 30 age- and sex-matched healthy controls (HCs). A 4-mm punch skin biopsy was obtained from lesional skin of patients and from normal skin of HCs for detection of TLR7 gene expression using real-time PCR. RESULTS: Mean TLR7 level in patients with MF (0.4 ± 0.23) was significantly lower than in patients with psoriasis (1.49 ± 0.46) and in HCs (1.22 ± 0.44) (P < 0.001), and mean TLR7 level in patients with psoriasis was significantly higher than in HCs (P < 0.03). Based on MF staging, 21.4% of patients had stage Ia, 28.6% had stage Ib, 28.6% had stage IIa and 21.4% had stage IIb disease. Comparing the TLR7 levels in relation to MF staging revealed the lowest mean value was in stage IIb and highest mean value in stage Ia, and this was significant (P < 0.001). CONCLUSION: Disturbed innate immunity might play a role in the pathogenesis of neoplastic and inflammatory skin conditions. TLR7 could be useful as a prognostic factor in MF.

Pediatric kidney transplantation in the developing world: challenges and solutions.

The prevalence of pediatric RRT and transplantation are low in developing countries, 6-12 and <1 to 5 per million child population (pmcp), respectively. This is due to low GDP/capita of <$10 000, government expenditure on health of <2.6-9% of GDP and paucity of facilities. The reported incidence of pediatric CKD and ESRD is <1.0-8 and 3.4-35 pmcp, respectively. RRT and transplantation are offered mostly in private centers in cities where HD costs $20-100/session and transplants $10 000-20 000. High costs and long distance to centers results in treatment refusal in up to 35% of the cases. In this backdrop 75-85% of children with ESRD are disfranchised from RRT and transplantation. Our center initiated an integrated dialysis-transplant program funded by a community-government partnership where RRT and transplantation was provided "free of cost" with life long follow-up and medication. Access to free RRT at doorsteps and transplantation lead to societal acceptance of transplantation as the therapy of choice for ESRD. This enabled us to perform 475 pediatric transplants in 25 years with 1- and 5-year graft survival of 96% and 81%, respectively. Our model shows that pediatric transplantation is possible in developing countries when freely available and accessible to all who need it in the public sector.

The Infectious Diseases Act and Resource Allocation during the COVID-19 Pandemic in Bangladesh.

The Infectious Diseases (Prevention, Control and Eradication) Act entered into force officially on 14 November 2018 in Bangladesh. The Act is designed to raise awareness of, prevent, control, and eradicate infectious or communicable diseases to address public health emergencies and reduce health risks. A novel coronavirus disease (COVID-19) was first identified in Bangladesh on 8 March 2020, and the Ministry of Health and Family Welfare issued a gazette on 23 March, listing COVID-19 as an infectious disease and addressing COVID-19 as a public health emergency. The gazette empowers the government to monitor the spread of infection. Despite there being an infrastructure of research ethics committees in almost all hospitals in Bangladesh, a lack of such committees in the clinical setting often forces healthcare professionals to allocate scarce healthcare resources to the task. These personnel are often either influenced by materialistic matters or guided by the emergency policies, without reaching a consensus on how to allocate scarce resources in times of need, especially in the time of the COVID-19 pandemic. Ethical dilemmas often arise when a number of patients with COVID-19, especially in poor and middle-class areas, are denied care while elites are prioritized to receive such scarce resources. Resource allocation in healthcare during the COVID-19 pandemic in Bangladesh appears to be unethical and in direct conflict with the biomedical principles of non-maleficence and procedural justice. The findings of this study suggest that the Act needs substantive changes in the stipulation of policy directing hospitals in the provision of resource allocation framework. Furthermore, parliament should produce guidance outlining how to successfully implement the law with the aim of protecting public health in times of emergency, especially the COVID-19 pandemic.

Mathematical Global Dynamics and Control Strategies on Echinococcus multilocularis Infection.

Echinococcus multilocularis, a major cause of echinococcosis in human, is a parasitic sylvatic disease between two major hosts in a predator-prey relation. A new model for the transmission dynamics of Echinococcus multilocularis in the population of red foxes and voles with environment as a source of infection is formulated and rigorously analyzed. The model is used to access the impact of treatment on red foxes and environmental disinfection as control strategies on the disease dynamics. The control reproduction number is computed and is used to rigorously prove the local and global dynamics of models' equilibria. Using available data on Echinococcus, elasticity indices and partial rank correlation coefficients of control reproduction number and cumulative new cases in red foxes and voles are computed. Parameters that have high influence locally and globally are identified. Numerical experiments indicate that administering disinfection of environment only induces more positive impact than applying treatment only on red foxes in controlling the infection. Generally, interventions towards treating red foxes and environmental disinfection could be sufficient in tackling transmission of disease in the populations.

Effects of chronic inhibition of glutathione biosynthesis on cholesterol and bile acid metabolism in rats.

The objective of this study was to examine the effect of chronic inhibition of glutathione (GSH) biosynthesis on cholesterol and bile acid metabolism in rats. Male Sprague-Dawley rats, weighing between 60 and 65 g, were randomly assigned to one of two groups and allowed a 1-week adaptation period to a 6 a.m.-6 p.m. light cycle. Food and water were available ad libitum. Following the adaptation period, 1 group was given a solution of 30 mM DL-buthionine sulfoximine (BSO, an inhibitor of GSH biosynthesis) in saline, while the other group received saline only. All studies were carried out during, or at the end of the second week of BSO treatment. While body weight was minimally affected by BSO treatment, liver weight (% of body weight) was significantly greater in the BSO group (control 4.8 +/- 0.2 vs. BSO 5.2 +/- 0.3; P less than 0.05). The increase in liver weight, however, was not associated with a change in the specific content of cytochrome P-450. Even though fecal output (g/100 g per day) was significantly greater in the BSO group (control 2.4 +/- 0.1 vs. BSO 2.7 +/- 0.3; P less than 0.05), it was not commensurate with an increase in fecal bile acids and neutral sterols. In fact, fecal bile acid excretion (mg/100 g per day) was significantly reduced in the BSO group (control 9.0 +/- 2.0 vs. BSO 6.2 +/- 0.9; P less than 0.05), a finding consistent with a significant reduction in bile acid pool size (mg/100 g) in that group (control 23.1 +/- 1.9 vs. BSO 14.3 +/- 4.8; P less than 0.05). Hepatic GSH content (mumol/g) and cholesterol 7 alpha-hydroxylase activity (pmol/mg per min) were assayed at two time points: 12-2 a.m. (mid-dark point) and 12-2 p.m. (mid-light point). At mid-dark point, BSO-treated animals had a significantly lower hepatic GSH content (control 4.5 +/- 0.3 vs. BSO 0.6 +/- 0.3; P less than 0.05) and a significantly lower cholesterol 7 alpha-hydroxylase activity (control 33.5 +/- 1.3 vs. BSO 14.7 +/- 3.9; P less than 0.05). At mid-light point, hepatic GSH content in the two groups was similar to that at mid-dark point. While cholesterol 7 alpha-hydroxylase activity in both groups was significantly lower (P less than 0.05) at mid-light point relative to that at mid-dark point, there was no difference between the two groups in cholesterol 7 alpha-hydroxylase activity at mid-light point.(ABSTRACT TRUNCATED AT 400 WORDS)

Abnormal bile acid pool and composition in neonates of spontaneously diabetic Wistar BB rats and its change during development.

Streptozotocin-induced diabetes during pregnancy in rats causes a decrease in primary bile acid pool in neonates. To rule out direct drug effect on the fetus as the basis for this change, studies of bile acid pool and composition at birth and during subsequent development was carried out in neonates of spontaneously diabetic Wistar BB rats and compared to control neonates. The cholic acid pool in neonates of diabetic rats was lower when compared to control neonates at birth. The pool of secondary bile acids was markedly increased in neonates of diabetic rats, with increases in lithocholic and 3 beta,12 alpha-dihydroxycholanoic acid. With age, the cholic acid pool of neonates from diabetic rats was increased and at 3 months of age it was actually higher than in control neonates. The pool of chenodeoxycholic at diabetes onset age was lower in neonates of diabetic rats. HDL-cholesterol was lower in neonates of diabetic rats at 1 week, but this reversed at 3 months of age. These studies firmly establish that neonates of diabetic rats have abnormal bile acid pool and composition at birth which changes to adult diabetic pattern with age.

Effect of enhancement of cholesterol catabolism in guinea pigs after weaning on subsequent response to dietary cholesterol.

Cholesterol catabolism was stimulated (by cholestyramine) in post-weaned guinea pigs for a 4-wk period. The animals were then switched to regular Chow diet for another 4 wk. When subsequently challenged with 0.25% cholesterol-containing Chow, plasma cholesterol level was significantly (p less than 0.05) lower in cholestyramine pretreated guinea pigs when compared to control guinea pigs and this "hyporesponder" pattern was maintained throughout the study period. Cholestyramine pretreated animals continued to excrete significantly (p less than 0.05) higher bile acids even at 4 wk after switching to regular Chow diet. This study demonstrates that stimulation of cholesterol catabolism even at postweaning stages can still be as effective in improving subsequent cholesterol handling capacity as noted previously after manipulation at the neonatal stage.

Cholestyramine treatment during pregnancy in the rat results in hypercholesterolemia.

Timed pregnant (8 days) Sprague-Dawley rats were fed ground stock diet (CON) or ground stock diet with 4% cholestyramine (CTR) until day 20 of gestation. Animals in both groups gained weight equally well during the study period (CON (n = 7), 308 +/- 7 g; CTR (n = 6), 315 +/- 7 g, mean +/- SEM). At the end of the study period, plasma cholesterol in the CTR group was significantly greater than that in the control group (CON n = 7, 91 +/- 4 mg/dl; CTR (n = 6), 108 +/- 5 mg/dl, P less than 0.05). The fecal excretion of both neutral steroids and bile acids, studied for 3 days between days 15 and 18 of gestation, was significantly enhanced by CTR treatment. (Neutral steroids: CON, 3.9 +/- 0.3; CTR, 10.4 +/- 0.3, P less than 0.05. Bile acids: CON, 7.6 +/- 0.4; CTR, 25.8 +/- 1.7, P less than 0.05, mg/100 g body wt/day). Bile acid pool size, measured at day 20 of gestation, however, was not significantly different. Consistent with these results was the finding that hepatic cholesterol 7 alpha-hydroxylase activity (the rate-limiting enzyme of bile acid biosynthesis) measured at day 20 of gestation was significantly enhanced by CTR treatment (CON (n = 4), 14.7 +/- 1.7; CTR (n = 4), 34.8 +/- 3.3, pmoles/mg/min, P less than 0.05). The atypical finding of hypercholesterolemia, despite the CTR-induced enhanced turnover of cholesterol, may be due to changes in the homeostatic mechanisms of cholesterol and bile acid metabolism during pregnancy.

Cholestyramine feeding in weaned rats. Increase in plasma corticosterone levels and bile acid synthesis following adrenalectomy.

Feeding cholestyramine to weaned rats increased the bile acid pool and activity of cholesterol 7 alpha-hydroxylase as expected. Following adrenalectomy, cholestyramine still increased the activity of cholesterol 7 alpha-hydroxylase but the magnitude of increase was lower (P less than 0.01) than noted in intact rats. Surprisingly, cholestyramine feeding to both intact and adrenalectomized rats increased plasma levels of corticosterone.

Glutathione and bile acid synthesis. Effect of GSH content of HepG2 cells on the activity and mRNA levels of cholesterol 7 alpha-hydroxylase.

Cholesterol 7 alpha-hydroxylase (CH-7 alpha) activity in HepG2 cells depleted of glutathione (GSH) was reduced significantly (P < 0.05) compared to that in untreated controls. Northern blot analysis of poly A+ mRNA isolated from GSH-depleted and control HepG2 cells showed that there was a reduction in mRNA for CH-7 alpha in treated HepG2 cells that was commensurate with the reduction in CH-7 alpha activity. The fact that total RNA, rRNA, and mRNA for beta fibrinogen were unaltered by the depletion of GSH suggests that the change in steady-state CH-7 alpha mRNA content is specifically sensitive to GSH content. This observation represents the first demonstration, for human liver cells, that there is an interaction between GSH levels and the regulation of CH-7 alpha mRNA levels.

Glutathione and bile acid synthesis. II. Effect of hepatic glutathione content on the activity and mRNA levels of cholesterol 7 alpha-hydroxylase in the rat.

Hepatic cholesterol 7 alpha-hydroxylase (CH-7 alpha) activity in intact rats depleted of glutathione (GSH) was reduced significantly (P < 0.007) compared with that in untreated controls. Northern blot analysis of poly A+ mRNA isolated from GSH-depleted and control rat livers showed that there was a reduction in mRNA for CH-7 alpha in treated rats that was commensurate with the reduction in CH-7 alpha activity. The fact that the level of transferrin mRNA was unaltered by the depletion of GSH suggests that the change in steady-state CH-7 alpha mRNA content is specifically sensitive to GSH content. This observation extends previous in vitro findings and provides strong justification for a more detailed biochemical investigation into the interaction between GSH levels and the regulation of CH-7 alpha mRNA levels.

Retinal toxicity of commercial intravitreal tissue plasminogen activator solution in cat eyes.

BACKGROUND: We previously reported retinal toxic reactions in rabbit eyes receiving intravitreal injections of commercial tissue plasminogen activator (tPA) in concentrations greater than or equal to 50 microg/0.1 mL, and recent clinical experience suggests that intravitreal tPA solution may produce toxic effects in human eyes. We therefore investigated the dose-dependent retinal toxicity of intravitreal commercial recombinant tPA solution in cat eyes, which have a vascularized inner retina and vitreous volume similar to that of human eyes. METHODS: Commercial tPA in L-arginine solution was injected into the mid vitreous cavity of normal cat eyes in doses of 25, 50, 75, and 100 microg/0.1 mL and 200 microg/0.2 mL. Control (fellow) eyes received an equal volume of sterile saline solution. After injection, eyes were evaluated by ophthalmoscopy and electroretinography for 14 days and then enucleated for histopathological evaluation. RESULTS: Fundus pigmentary alterations were observed in eyes receiving doses greater than or equal to 50 microg/0.1 mL. Changes were centered in the area around the injection site, and the area's size increased in proportion to the dosage. Mean electroretinography B-wave amplitude measured at 14 days was significantly reduced in eyes receiving greater than or equal to 50 microg of tPA in a dose-dependent fashion. Light microscopy of the involved areas showed loss of photoreceptor elements with necrosis and proliferation of the retinal pigment epithelium. CONCLUSION: Intravitreal injection of commercial tPA solution results in dose-dependent retinal toxicity in cat eyes. CLINICAL RELEVANCE: Because cat eyes are similar to human eyes regarding retinal vascularity and vitreous volume, intravitreal injections of commercial tPA (with L-arginine vehicle) in concentrations greater than 25 microg/0.1 mL are potentially unsafe in human eyes.

Alterations in liver nucleic acids and nucleotides in arginine deficient rats.

Dietary arginine deficiency is associated with retarded growth and depressed feed intake. Nucleic acid biosynthesis as indicated by the incorporation of [6-14C]-orotic acid and [32P]-orthophosphate was significantly depressed in rats fed an arginine deficient diet. The activities of the pyrimidine enzymes, aspartate transcarbamylase (ATC) and dihydroorotate dehydrogenase (DHODH) were significantly increased in rats fed an arginine deficient diet. ATC and DHODH activities in rats fed the arginine deficient diet returned to control activities after 3 wk of feeding. Orotidine 5' phosphate decarboxylase and orotate phosphoribosyl transferase activities were not affected by dietary arginine availability. In the rat fed an arginine deficient diet there was an increase in total liver pyrimidine nucleotides and a decrease in the total purine nucleotides. Significant alterations in the individual liver nucleotides were also observed. Incubation of various tissues obtained from rats fed an arginine deficient diet or a complete diet with glutamine (5mM) revealed that the liver is the major site of orotic acid synthesis. Orotic acid production in liver slices using glutamine as the nitrogen source was significantly greater in rats fed an arginine deficient diet compared to controls. The orotic aciduria occurring in rats fed an arginine deficient diet is associated with increased synthesis and decreased utilization of pyrimidines.

Effect of prior high-intensity exercise on exercise-induced arterial hypoxemia in Thoroughbred horses.

Strenuously exercising horses exhibit arterial hypoxemia and exercise-induced pulmonary hemorrhage (EIPH), the latter resulting from stress failure of pulmonary capillaries. The present study was carried out to examine whether the structural changes in the blood-gas barrier caused by a prior bout of high-intensity short-term exercise capable of inducing EIPH would affect the arterial hypoxemia induced during a successive bout of exercise performed at the same workload. Two sets of experiments, double- and single-exercise-bout experiments, were carried out on seven healthy, sound Thoroughbred horses. Experiments were carried out in random order, 7 days apart. In the double-exercise experiments, horses performed two successive bouts (each lasting 120 s) of galloping at 14 m/s on a 3.5% uphill grade, separated by an interval of 6 min. Exertion at this workload induced arterial hypoxemia within 30 s of the onset of galloping as well as desaturation of Hb, a progressive rise in arterial PCO2, and acidosis as exercise duration increased from 30 to 120 s. In the single-exercise-bout experiments, blood-gas/pH data resembled those from the first run of the double-exercise experiments, and all horses experienced EIPH. Thus, in the double-exercise experiments, before the horses performed the second bout of galloping at 14 m/s on a 3.5% uphill grade, stress failure of pulmonary capillaries had occurred. Although arterial hypoxemia developed during the second run, arterial PO2 values were significantly (P < 0.01) higher than in the first run. Thus prior exercise not only failed to accentuate the severity of arterial hypoxemia, it actually diminished the magnitude of exercise-induced arterial hypoxemia. The decreased severity of exercise-induced arterial hypoxemia in the second run was due to an associated increase in alveolar PO2, as arterial PCO2 was significantly lower than in the first run. Thus our data do not support a role for structural changes in the blood-gas barrier related to the stress failure of pulmonary capillaries in causing the exercise-induced arterial hypoxemia in horses.

Nitric oxide synthase inhibition does not affect the exercise-induced arterial hypoxemia in Thoroughbred horses.

Because sensitivity of equine pulmonary vasculature to endogenous as well as exogenous nitric oxide (NO) has been demonstrated, we examined whether endogenous NO production plays a role in exercise-induced arterial hypoxemia. We hypothesized that inhibition of NO synthase may alter the distribution of ventilation-perfusion mismatching, which may affect the exercise-induced arterial hypoxemia. Arterial blood-gas variables were examined in seven healthy, sound Thoroughbred horses at rest and during incremental exercise protocol leading to galloping at maximal heart rate without (control; placebo = saline) and with N(omega)-nitro-L-arginine methyl ester (L-NAME) administration (20 mg/kg iv). The experiments were carried out in random order, 7 days apart. At rest, L-NAME administration caused systemic hypertension, pulmonary hypertension, and bradycardia. During 120 s of galloping at maximal heart rate, significant arterial hypoxemia, desaturation of hemoglobin, hypercapnia, hyperthermia, and acidosis occurred in the control as well as in NO synthase inhibition experiments. However, statistically significant differences between the treatments were not found. In both treatments, exercise caused a significant rise in hemoglobin concentration, but the increment was significantly attenuated in the NO synthase inhibition experiments, and, therefore, arterial O(2) content (Ca(O(2))) increased to significantly lower values. These data suggest that, whereas L-NAME administration does not affect pulmonary gas exchange in exercising horses, it may affect splenic contraction, which via an attenuation of the rise in hemoglobin concentration and Ca(O(2)) may limit performance at higher workloads.

Nasal strips do not affect pulmonary gas exchange, anaerobic metabolism, or EIPH in exercising Thoroughbreds.

The present study was carried out to examine whether nasal strip application would improve the exercise-induced arterial hypoxemia and hypercapnia, diminish anaerobic metabolism, and modify the incidence of exercise-induced pulmonary hemorrhage (EIPH) in horses. Two sets of experiments, control and nasal strip experiments, were carried out on seven healthy, sound, exercise-trained Thoroughbred horses in random order, 7 days apart. Simultaneous measurements of core temperature, arterial and mixed venous blood gases/pH, and blood lactate and ammonia concentrations were made at rest, during submaximal and near-maximal exercise, and during recovery. In both treatments, whereas submaximal exercise caused hyperventilation, near-maximal exercise induced significant arterial hypoxemia, desaturation of Hb, hypercapnia, and acidosis. However, O2 content increased significantly with exercise in both treatments, while the mixed venous blood O2 content decreased as O2 extraction increased. In both treatments, plasma ammonia and blood lactate concentrations increased significantly with exercise. Statistically significant differences between the control and the nasal strip experiments could not be discerned, however. Also, all horses experienced EIPH in both treatments. Thus our data indicated that application of an external nasal dilator strip neither improved the exercise-induced arterial hypoxemia and hypercapnia nor diminished anaerobic metabolism or the incidence of EIPH in Thoroughbred horses performing strenuous exercise.

Glutathione levels in specific brain regions of genetically epileptic (tg/tg) mice.

The tottering (tg/tg) mouse is a genetic model of human generalized epilepsy; these mice exhibit spontaneous absence seizures accompanied by bilaterally synchronous spike-wave discharges (6). The mechanism(s) for seizure activity are unknown in these mice. Several recent studies have suggested that membrane lipid peroxidation may be causally involved in some forms of experimentally induced epilepsies (18). Since reduced glutathione (GSH) is the most important free radical scavenging compound in vivo that can prevent membrane lipid peroxidation, the objective of this study was to investigate GSH concentrations in specific central nervous system regions of genetically epileptic, tg/tg, mice as compared to age-matched controls. Three brain regions, cerebellum, hippocampus, and occipital cortex, were dissected, weighed and the concentrations of reduced and oxidized glutathione (GSH and GSSG, respectively) were measured in each of these tissues. GSH content was significantly lower in the occipital cortex of tg/tg mice compared to controls; no differences were observed in the other two brain regions examined. Total GSH content (GSH plus 2 x GSSG) paralleled GSH concentration differences. GSSG content from tg/tg mice was lower in the hippocampus and occipital cortex, compared to controls. This is the first report of an association between decreased central nervous system glutathione concentrations and seizure activity in animals exhibiting generalized seizures.

Bile acids in the fetal rat: effect of maternal bile duct ligation.

The effect of bile duct ligation during pregnancy in rats (thereby increasing maternal plasma bile acids levels) on the bile acid content and composition in the fetus was examined. In spite of 30-fold increase in maternal plasma cholic acid, the bile acid content in the fetus of bile duct ligated rats was significantly lower (p less than 0.05) with a significant reduction in cholic acid content. Plasma cholesterol levels of fetuses from bile duct ligated rats were also significantly lower (p less than 0.05). In addition to the commonly expected bile acids, gas-liquid chromatographic analysis of the fetal bile acid pool showed peaks corresponding to several secondary bile acids. These results suggest that the transfer of primary bile acids of maternal origin into the fetus is minimal.

Effect of beta-sitostanol (5 alpha-stigmastan-3 beta-ol) on cholesterol absorption from micellar solutions in jejunal loops in situ.

In situ jejunal loops were infused with micellar solutions of cholesterol with or without beta-sitostanol (5 alpha-stigmastan-3 beta-ol), and the uptake of 14C-cholesterol by the loop was followed for 20 minutes. It was found that beta-sitostanol, given as a 'solution-mix' (a solution resulting from the mixture of two separate micellar solutions of cholesterol and beta-sitostanol), at a concentration of 0.30 mM reduced cholesterol uptake. Substituting cholesterol for beta-sitostanol in the 'solution-mix' had no effect on cholesterol uptake by the loop. beta-Sitostanol at a concentration of 0.30 mM in the 'pre-mix' (a solution resulting from pre-mixing of the two sterols prior to preparation of the micellar solution) condition, had no effect on cholesterol absorption. Taken together, these results suggest that the concentration of beta-sitostanol-containing micelles is the important factor in its suppression of cholesterol absorption.