Efficacy and safety profile of corticosteroids and non-steroidal anti-inflammatory drugs in COVID-19 management: A narrative review

Due to the fact that coronavirus disease 2019 (COVID-19) is still prevalent, and current reports show that some parts of the world have seen increase in incidence, it is relevant that health professionals and scientists know about recent or novel trends, especially drug treatments. Additionally, the safety profiles of these drug treatments need to be documented and shared with the public. Some studies have demonstrated the clinical benefits of non-steroidal anti-inflammatory drugs (NSAIDs) and corticosteroids in COVID-19 treatment. On the contrary, others have also reported that NSAIDs and corticosteroids may worsen symptoms associated with COVID-19. While some researchers have suggested that corticosteroids may be helpful if used in the early stages of COVID-19, there are still some conflicting findings regarding the use of corticosteroids in certain viral infections. Our review suggests that methylprednisolone, dexamethasone, and ibuprofen have therapeutic potential in reducing mortality due to COVID-19 among hospitalized patients. This review also highlights the fact that the use of NSAIDs is not associated with adverse outcomes of COVID-19. In reality, evidence suggests that NSAIDs do not increase the risk of COVID-19 infections. Also, the literature reviewed suggests that corticosteroid treatment in COVID-19 was linked with a decrease in all-cause mortality and disease progression, without increase in adverse events when compared to no corticosteroid treatment.

Pharmaceutical and pharmacokinetic evaluation of a newly formulated multiparticulate matrix of levodopa and carbidopa

Levodopa is routinely co-administered with carbidopa in the management of Parkinson's disease. Although the aforementioned combination therapy is effective, there may be fluctuating plasma levels of levodopa after oral administration. We formulated and evaluated the kinetic characteristics of the chitosan-pectin-based multiparticulate matrix of levodopa and carbidopa. Pectin was extracted from the cocoa husk, and the chitosan-pectin-based matrix was prepared by wet granulation. Formulations were evaluated for drug-excipient compatibility, drug content, precompression properties and in vitro release. For pharmacokinetic evaluation, rats were put into groups and administered either chitosan-pectin based matrix of levodopa/carbidopa, Sinemet^® CR or levodopa/carbidopa immediate release powder. Rats were administered the different formulations of levodopa/carbidopa (20/5 mg/kg) per os every 12 hours. The pharmacokinetic parameters of levodopa were estimated for the various treatment groups. The percentage content of levodopa and carbidopa in the various formulations was within the acceptance criteria. The AUC_0-24 for levodopa/carbidopa multiparticulate matrix (Formulation 3: 484.98 ± 18.70 μg.hr/mL); Formulation 4: 535.60 ± 33.04 μg.hr/mL), and C_max (Formulation 3: 36.28 ± 1.52 μg/mL; Formulation 4: 34.80 ± 2.19 μg/mL) were higher than Sinemet^® CR (AUC_0-24 262.84 ± 16.73 μg.hr/mL and C_max 30.62 ± 3.37 μg/mL). The t _1/2 of the new formulation was longer compared to Sinemet^® CR.

Targeting hepatic sulfane sulfur/hydrogen sulfide signaling pathway with α-lipoic acid to prevent diabetes-induced liver injury via upregulating hepatic CSE/3-MST expression

BACKGROUND

Diabetes-induced liver injury is a complication of diabetes mellitus of which there are no approved drugs for effective treatment or prevention. This study investigates possible hepatoprotective effect of alpha-lipoic acid (ALA), and sulfane sulfur/hydrogen sulfide pathway as a novel protective mechanism in a rat model of type 2 diabetes-induced liver injury.

METHODS

Thirty Sprague-Dawley rats underwent fasting for 12 h after which fasting blood glucose was measured and rats were randomly assigned to diabetic and non-diabetic groups. Type 2 diabetes mellitus (T2DM) was induced in diabetic group by administration of nicotinamide (110 mg/kg) and streptozotocin (55 mg/kg). Diabetic rats were treated daily with ALA (60 mg/kg/day p.o.) or 40 mg/kg/day DL-propargylglycine (PPG, an inhibitor of endogenous hydrogen sulfide production) for 6 weeks and then sacrificed. Liver, pancreas and blood samples were collected for analysis. Untreated T2DM rats received distilled water.

RESULTS

Hypoinsulinemia, hyperglycemia, hepatomegaly and reduced hepatic glycogen content were observed in untreated T2DM rats compared to healthy control group (p < 0.001). Also, the pancreas of untreated T2DM rats showed severely damaged pancreatic islets while liver damage was characterized by markedly increased hepatocellular vacuolation, sinusoidal enlargement, abnormal intrahepatic lipid accumulation, severe transaminitis, hyperbilirubinemia, and impaired hepatic antioxidant status and inflammation compared to healthy control rats (p < 0.01). While pharmacological inhibition of hepatic sulfane sulfur/hydrogen sulfide with PPG administration aggravated these pathological changes (p < 0.05), ALA strongly prevented these changes. ALA also significantly increased hepatic expression of hydrogen sulfide-producing enzymes (cystathionine γ-lyase and 3-mecaptopyruvate sulfurtransferase) as well as hepatic sulfane sulfur and hydrogen sulfide levels compared to all groups (p < 0.01).

CONCLUSIONS

To the best of our knowledge, this is the first experimental evidence showing that ALA prevents diabetes-induced liver injury by activating hepatic sulfane sulfur/hydrogen sulfide pathway via upregulation of hepatic cystathionine γ-lyase and 3-mecaptopyruvate sulfurtransferase expressions. Therefore, ALA could serve as a novel pharmacological agent for the treatment and prevention of diabetes-induced liver injury, with hepatic sulfane sulfur/hydrogen sulfide as a novel therapeutic target.

Alpha-lipoic acid treatment improves adverse cardiac remodelling in the diabetic heart - The role of cardiac hydrogen sulfide-synthesizing enzymes

INTRODUCTION

Alpha-lipoic acid (ALA) is a licensed drug for the treatment of diabetic neuropathy. We recently reported that it also improves diabetic cardiomyopathy (DCM) in type 2 diabetes mellitus (T2DM). In this study, we present evidence supporting our hypothesis that the cardioprotective effect of ALA is via upregulation of cardiac hydrogen sulfide (H₂S)-synthesizing enzymes.

METHODS

Following 12 h of overnight fasting, T2DM was induced in 23 out of 30 male Sprague-Dawley rats by intraperitoneal administration of nicotinamide (110 mg/kg) followed by streptozotocin (55 mg/kg) while the rest served as healthy control (HC). T2DM rats then received either oral administration of ALA (60 mg/kg/day; n = 7) or 40 mg/kg/day DL-propargylglycine (PAG, an endogenous H₂S inhibitor; n = 7) intraperitoneally for 6 weeks after which all rats were sacrificed and samples collected for analysis. Untreated T2DM rats served as diabetic control (DCM; n = 9).

RESULTS

T2DM resulted in weight loss, islet destruction, reduced pancreatic β-cell function and hyperglycemia. Histologically, DCM rats showed significant myocardial damage evidenced by myocardial degeneration, cardiomyocyte vacuolation and apoptosis, cardiac fibrosis and inflammation, which positively correlated with elevated levels of cardiac damage markers compared to HC rats (p < 0.001). These pathological alterations worsened significantly in PAG-treated rats (p < 0.05). However, ALA treatment restored normoinsulemia, normoglycemia, prevented DCM, and improved lipid and antioxidant status. Mechanistically, ALA significantly upregulated the expression of cardiac H₂S-synthesizing enzymes and increased plasma H₂S concentration compared to DCM rats (p < 0.001).

CONCLUSION

ALA preserves myocardial integrity in T2DM likely by maintaining the expression of cardiac H₂S-synthezing enzymes and increasing plasma H₂S level.

Activation of renal CSE/H2S pathway by alpha-lipoic acid protects against histological and functional changes in the diabetic kidney

INTRODUCTION

We previously reported that alpha-lipoic acid (ALA) supplementation protects against progression of diabetic kidney disease (DKD). In this study, we aim to investigate whether the mechanism of renal protection by ALA involves renal cystathionine γ-lyase/hydrogen sulfide (CSE/H₂S) system in type 2 diabetes mellitus (T2DM).

METHODS

Thirty-seven male Sprague-Dawley rats underwent 12 h of overnight fasting. To induce T2DM, 30 of these rats received intraperitoneal administration of nicotinamide (110 mg/kg) and streptozotocin (55 mg/kg). T2DM rats then received either oral administration of ALA (60 mg/kg/day) or intraperitoneal administration of 40 mg/kg/day DL-propargylglycine (PAG, a CSE inhibitor) or both for 6 weeks after which rats were sacrificed and samples collected for analysis. Untreated diabetic and non-diabetic rats served as diabetic and healthy controls respectively.

RESULTS

T2DM was characterized by reduced pancreatic β-cell function and hyperglycemia. Histologically, untreated diabetic rats showed significantly damaged pancreatic islets, glomerular and tubular injury, with elevated levels of renal function markers compared to healthy control rats (p < 0.001). These pathological changes worsened significantly following PAG administration (p < 0.05). While some renal protection was observed in ALA+PAG rats, ALA administration in untreated diabetic rats provided superior protection comparable to healthy control rats, with improved antioxidant status, lipid profile and reduced inflammation. Mechanistically, ALA significantly activated renal CSE/H₂S system in diabetic rats, which was markedly suppressed in PAG-treated rats (p < 0.001).

CONCLUSION

Our data suggest that ALA protects against DKD development and progression by activating renal CSE/H₂S pathway. Hence, CSE/H₂S pathway may represent a therapeutic target in the treatment or prevention of DKD in diabetic patients.

Effect of Metaswitch® dietary supplement on anthropometric parameters, serum lipids, glucose level, oxidative stress and in vivo antioxidant properties in high fat diet-induced overweight Sprague Dawley rats

PURPOSE

Obesity and overweight are metabolic disorders associated with oxidative stress, and risk factors for many chronic diseases. We sought to investigate the effects of Metaswitch dietary supplement on weight gain and associated acute metabolic alterations in a high-fat diet-induced overweight rat model.

METHODS

Female Sprague Dawley (SD) rats were put into 6 groups. Control groups were fed normal (NCD) or high-fat diet (HFD). Treatment groups on HFD receieved 3 different daily doses of Metaswitch for 3 weeks. Another group on HFD received Slimrite® (phenylpropanolamine), a standard drug. Rats on HFD also received cyproheptadine to stimulate appetite. Food consumption and anthropometric parameters were determined weekly. Serum lipids, glucose level, hepatic lipid peroxidation, and antioxidant activity were used to assess overweight in rats.

RESULTS

Food intake remained relatively constant among groups. Rats on HFD had significantly increased body weight compared to rats fed NCD. Metaswitch significantly prevented weight gain; this effect was greater or similar to rats administered Slimrite, but was not dose-dependant. No significant changes occurred in the levels of serum lipids and glucose among the groups. However, serum triglyceride (TG) was significantly increased. The TG/HDL-C ratio revealed significant metabolic alterations which was prevented by Metaswitch. Catalase activity was significantly decreased in the HFD untreated group but was restored in Metaswitch-treated groups.

CONCLUSIONS

A 3-week HFD regimen with cyproheptadine supplementation in female SD rats resulted in a significant increase in body weight and acute metabolic alterations. The aforementioned changes were found to have been prevented with the administration of Metaswitch.

Combination Therapy of Alpha-Lipoic Acid, Gliclazide and Ramipril Protects Against Development of Diabetic Cardiomyopathy via Inhibition of TGF-β/Smad Pathway

Background: Diabetic cardiomyopathy (DCM) is a major long-term complication of diabetes mellitus, accounting for over 20% of annual mortality rate of diabetic patients globally. Although several existing anti-diabetic drugs have improved glycemic status in diabetic patients, prevalence of DCM is still high. This study investigates cardiac effect of alpha-lipoic acid (ALA) supplementation of anti-diabetic therapy in experimental DCM. Methods: Following 12 h of overnight fasting, 44 male Sprague Dawley rats were randomly assigned to two groups of healthy control (n = 7) and diabetic (n = 37) groups, and fasting blood glucose was measured. Type 2 diabetes mellitus (T2DM) was induced in diabetic group by intraperitoneal (i.p.) administration of nicotinamide (110 mg/kg) and streptozotocin (55 mg/kg). After confirmation of T2DM on day 3, diabetic rats received monotherapies with ALA (60 mg/kg; n = 7), gliclazide (15 mg/kg; n = 7), ramipril (10 mg/kg; n = 7) or combination of the three drugs (n = 7) for 6 weeks while untreated diabetic rats received distilled water and were used as diabetic control (n = 9). Rats were then sacrificed, and blood, pancreas and heart tissues were harvested for analyses using standard methods. Results: T2DM induction caused pancreatic islet destruction, hyperglycemia, weight loss, high relative heart weight, and development of DCM, which was characterized by myocardial degeneration and vacuolation, cardiac fibrosis, elevated cardiac damage markers (plasma and cardiac creatine kinase-myocardial band, brain natriuretic peptide and cardiac troponin I). Triple combination therapy of ALA, gliclazide and ramipril preserved islet structure, maintained body weight and blood glucose level, and prevented DCM development compared to diabetic control (p < 0.001). In addition, the combination therapy markedly reduced plasma levels of inflammatory markers (IL-1β, IL-6 and TNF-α), plasma and cardiac tissue malondialdehyde, triglycerides and total cholesterol while significantly increasing cardiac glutathione and superoxide dismutase activity and high-density lipoprotein-cholesterol compared to diabetic control (p < 0.001). Mechanistically, induction of T2DM upregulated cardiac expression of TGF-β1, phosphorylated Smad2 and Smad3 proteins, which were downregulated following triple combination therapy (p < 0.001). Conclusion: Triple combination therapy of ALA, gliclazide and ramipril prevented DCM development by inhibiting TGF-β1/Smad pathway. Our findings can be extrapolated to the human heart, which would provide effective additional pharmacological therapy against DCM in T2DM patients.

A comparative analysis of pattern and attitude towards self-medication among pharmacy and non-pharmacy students in University of Ghana

Introduction

self-medication involves the use of medicines without the input of health professionals. Available studies are not entirely conclusive on self-medication among health science versus non-health science university students. The current study therefore sought to investigate relevant aspects of self-medication among pharmacy and non-pharmacy students.

Methods

this quantitative cross-sectional research was conducted among undergraduate pharmacy and non-pharmacy students of the University of Ghana from October 1^st 2019 to December 6^th 2019. Using a questionnaire, interviews were conducted to assess the pattern and attitude towards self-medication among respondents within the last 2 months.

Results

a total of 337 (163 pharmacy and 174 non-pharmacy) students filled and completed questionnaires. The prevalence of self-medication was 55.2% for pharmacy and 51.1% for non-pharmacy students. Both pharmacy and non-pharmacy students were either accepting or ambivalent towards self-medication. Painkillers were the major class of medications that were self-medicated by both pharmacy (38.5%) and non-pharmacy students (30.7%). The most common reason for self-medication among pharmacy (62.2%) and non-pharmacy (56.2%) students was the need for rapid relief from an illness. Majority of the participants who were self-medicated (27.6% among non-pharmacy and 36.8% among pharmacy students) demonstrated ambivalent attitude towards self-medication. An increase in the study level reduced the likelihood of self-medication in both pharmacy and non-pharmacy students: OR=0.442, CI = 0.266-0.736 for pharmacy students and OR=0.671, CI = 0.456-0.987 for non-pharmacy students.

Conclusion

self-medication is common students of the University of Ghana. Prevalence of self-medication was higher among pharmacy students than non-pharmacy students. This study provides data for targeted education and sensitisation of self-medication among university students.

Chitosan-Coated Hydroxypropylmethyl Cellulose Microparticles of Levodopa (and Carbidopa): In Vitro and Rat Model Kinetic Characteristics

Background

Parkinson's disease is a neurodegenerative disorder, and a major cause of disability. Levodopa, a prodrug of dopamine, remains the gold standard in the pharmacological management of Parkinson's disease. Despite several attempts to improve the clinical efficacy of levodopa, new oral levodopa formulations are needed to overcome irregular absorption and variable plasma concentrations.

Objective

The aim of this study was to evaluate the in vitro and in vivo kinetic properties of chitosan-coated hydroxypropylmethyl cellulose microparticles of levodopa (and carbidopa).

Methods

Microparticles were formulated by encapsulating levodopa powder in chitosan-coated hydroxypropylmethyl cellulose using the spray-drying method. Levodopa microparticles were evaluated for size, zeta potential, drug loading capacity, encapsulation efficiency and in vitro release. In evaluating in vivo pharmacokinetics, Sprague Dawley rats were administered either levodopa/carbidopa powder, levodopa/carbidopa microparticles, or Sinemet CR (a controlled release formulation of levodopa/carbidopa). The dose of respective formulations administered was 20/5 mg/kg; 20 mg levodopa combined with 5 mg carbidopa per kilogram body weight of animals. Treatments were administered via the oral route every 12 hours. Blood samples were collected after predetermined times following the third dose. Plasma was obtained from blood collected, and levodopa levels determined by HPLC. Pharmacokinetic parameters, including C_max, T_max, AUC, and t_½ of the various formulations, were estimated.

Results

The mean (SD) size of levodopa microparticles was 0.5 (0.05) µm with polydispersity index of 0.41 and a zeta potential of 10.8 mV. Of the expected 20% drug loading, the actual drug loading capacity of levodopa microparticles was found to be 19.1%, giving an encapsulation efficiency of 95.7%. The in vitro release kinetics of levodopa microparticles showed a controlled and sustained release, with about 80% release occurring after 12 hours. In vivo pharmacokinetic studies showed that rats administered levodopa/carbidopa microparticles had greater AUC (612.7 [17.42] ng.h/mL) and higher C_max (262.4 [38.86] ng/mL) compared with Sinemet CR: AUC 354.7 (98.09) ng.h/mL and C_max 95.5 (20.87) ng/mL. However, Sinemet CR had a much longer half-life (6.1 [2.58] hours) compared with levodopa/carbidopa microparticles (2.0 [0.31] hours).

Conclusions

Findings from this study suggest that chitosan-coated hydroxypropylmethyl cellulose microparticles of levodopa/carbidopa may give relatively high levels of levodopa in circulation. (Curr Ther Res Clin Exp. 2020; 81:XXX–XXX)

© 2020 Elsevier HS Journals, Inc.

0367 Social Determinants of Black-White Disparities in the Work-Sleep Relationship by Occupational Class: A Sequential Mixed Methods Approach

Introduction

Although Black adults disproportionately work in lower-wage, lower-skilled jobs and experience short sleep (&lt;7 hours), which has been shown to vary by employment industry and occupation, there is scant literature regarding the influence of the work-sleep relationship on racial/ethnic sleep disparities. Our prior quantitative research based on nationally-representative data revealed a novel finding that the prevalence of short sleep was generally highest at professional occupational classes among Black adults but was the least prevalent among their White counterparts.

Methods

To identify reasons for short sleep generally increasing with increasing professional occupations among blacks but decreasing among whites, we conducted a qualitative study using a sequential mixed methods design among Black and White workers across a range of industries and occupations. Occupations were classified as “professional” (e.g., doctors; lawyers) or “non-professional” (e.g., retail; food service). Race-matched trained facilitators conducted 36 focus groups that were homogenous in terms of race-sex/gender-occupational class and 63 one-on-one interviews (N=334 overall participants) using semi-structured interview guides. NVivo software was used to identify themes/patterns.

Results

Participants were a mean age of 41 ± 11 years, 42% were men, 58% had an annual income of ≥$50,000, and 57% were professionals. Black professionals overwhelmingly described less informational and emotional support as well as needing to “work twice as hard to get half as far” (i.e., John Henryism) compared to coworkers as potential explanations for work-sleep disparities. Both Black and White professionals identified longstanding social structures, interpersonal discrimination, income disparities, and familial or self-imposed pressures to succeed. White professional women frequently reported experiences with gender discrimination, which - they reported - may intersect with and amplify the effects of racial discrimination among Black women. Regardless of occupational class, Black men additionally described unique stressors (e.g., political climate; finances; police). White men frequently avoided discussing disparities, and the existence of disparities was often denied/questioned by non-professionals across race and sex/gender.

Conclusion

Our findings inform future research and interventions designed to illuminate and/or address sleep disparities emanating from the workplace.

Support

This work was funded by the Intramural Program at the National Institute of Environmental Health Sciences (Z1AES103325-01).

The development of a bridging social capital questionnaire for use in population health research

Bridging social capital is defined as the connections between individuals who are dissimilar with respect to socioeconomic and other characteristics. There is an important gap in the literature related to its measurement. We describe the development and validation of a questionnaire to measure bridging social capital. We focused the development of the questionnaire to be suitable for use in Latino immigrant populations in the U.S. The structure of the questionnaire comprised the following: Socialization in the job place (5 items); Membership in community activities (16 items); Participation in community activities (5 items); Contact with similar/different people (7 items); Assistance (17 items); Trust of institutions, corporations and other people(14 items); and Trust of intimate people (3 items). First, we used focus groups (N=17 participants) to establish content validity with an inductive thematic analysis to identify themes and subthemes. Changes were made to the questionnaire based on difficulty, redundancy, length and semantic equivalence. Second, we analyzed the questionnaire's psychometric properties (N=138). We tested internal consistency with Cronbach alpha and construct validity with a Confirmatory Factor Analysis (CFA) for each sub-scale to test theoretical unity; discriminant validity to observe differences between participants from high and low SES backgrounds and different language; and content validity with an independent expert panel. Cronbach alphas ranged from 0.80 (Assistance) to 0.92 (Trust). CFA results indicated that CFI and TLI were higher than 0.90 in almost all the scales, with high factor loadings. The Wilcoxon tests indicated that there were statistically significant mean differences between SES and language groups (p<0.00). The independent expert panel determined that the questionnaire had good content validity. This is the first demonstration of a psychometrically validated questionnaire to measure bridging social capital in an immigrant population in the United States. Our questionnaire may be suitable for further refinement and adaptation to other immigrant groups in different countries.

Tobacco use among low-income housing residents: does hardship motivate quit attempts?

PURPOSE

The purpose of this study was to examine material hardship among smokers to determine whether such hardship was positively associated with current attempts to quit tobacco use.

METHODS

We analyzed cross-sectional data from the Health in Common (HIC) study, an observational study to investigate social and physical determinants of cancer risk-related behaviors among residents of low-income housing in three cities in the Boston metropolitan area. In this study, three indicators of hardship were used: food hardship, financial hardship, and material hardship (food and financial hardship combined). Logistic regression models were used to obtain the odds of currently trying to quit among current smokers in the HIC (n = 170) across hardship types experienced, adjusting for sociodemographic and psychosocial factors.

RESULTS

Fully adjusted models revealed no statistically significant association between trying to quit tobacco use and indicators of material hardship: food hardship and financial hardship present (OR 1.33 (0.42-4.2); food hardship and no financial hardship OR 3.83 (0.97-15.13); and financial hardship but no food hardship OR 0.5 (0.1-2.39).

CONCLUSIONS

These findings suggest that even in the presence of material hardship, low-income housing resident tobacco users are not more likely to quit tobacco use; therefore, cessation efforts focused on the financial benefits of quitting may be insufficient to motivate quit attempts among low-income smokers.

Influenza B pneumonia with Staphylococcus aureus superinfection associated with parvovirus B19 and concomitant agranulocytosis

An 11-year-old patient with anamnestic fever for 3 days and signs of upper respiratory tract infection underwent fulminant Staphylococcus aureus pneumonia with concomitant agranulocytosis. From autopsia influenza B virus and parvovirus B19 were detected by nucleic acid amplification technique (NAT). Specific IgG but no IgM points to preexisting parvovirus B19 infection. Whether in this case agranulocytosis can be interpreted as early manifestation of reactivated parvovirus B19 infection is under discussion. Therefore, parvovirus B19 could have provoked a foudroyant course of influenza B pneumonia which was superinfected with S. aureus.

Fluvastatin induces apoptosis of vascular endothelial cells: blockade by glucocorticoids

Statins block de novo synthesis of cholesterol by inhibiting the enzyme, HMG CoA reductase. The product of this reaction, mevalonic acid, is also a precursor of isoprenoids, molecules required for the activation of signaling G-proteins, such as Ras. Signal transduction pathways involving Ras are important for cell survival and this may be why statins induce apoptotic death of several cell types. Given that statins are used to treat vascular disease, surprisingly no studies have been conducted on vascular endothelial cells. Here we show that fluvastatin (FS), at concentrations from 1-2 microM, blocks growth and induces apoptosis of the endothelial cell line, EA.hy 926. Considerable redundancy is known to exist in cell signaling and in vivo toxicity of FS might be prevented by other signaling pathways, like those activated by adrenal or sex steroids. RT-PCR analysis revealed the expression of the androgen and glucocorticoid receptor in EA.hy 926 cells. Although the androgen, dihydrotestesterone (DHT) had no effect, the glucocorticoid, dexamethasone (Dex), blocked FS-induced apoptosis. Cell cycle analysis revealed that 24 h exposure to FS prevented cells from leaving G(1) and 24-48 h later a marked sub-G(1) peak was observed. Dex was able to reduce the sub-G(1) peak, but it failed to block accumulation of cells in G(1), indicating that it's effect was specific for blockade of apoptosis, and not specific to an effect on FS alone. This study strongly suggests that glucocorticoids have a role to play in preventing vascular injury and they may provide the reason why statins are not inherently toxic to vascular endothelial cells, in vivo.

Statin-induced apoptosis of vascular endothelial cells is blocked by dexamethasone

Statins block de novo synthesis of cholesterol by inhibiting the enzyme, HMG CoA reductase. The product of this reaction, mevalonic acid, is also a precursor of isoprenoids, molecules required for the activation of signalling G-proteins, such as Ras. Signal transduction pathways involving Ras are important for cell survival and this may be why statins induce apoptotic death of several cell types. Given that statins are used to treat vascular disease, it is surprising that no studies have been conducted on vascular endothelial cells. For this reason, we have tested the effect of fluvastatin (FS) on the endothelial cell line EA.hy 926. Here we show that FS, at concentrations from 1 to 2 microM, blocks growth and induces apoptosis of the endothelial cell line, EA.hy 926. As considerable redundancy exists in cell signalling pathways for cell survival, toxicity of FS under more physiological conditions might be prevented by pathways that do not require Ras, such as those activated by adrenal or sex steroids. To test this hypothesis, first RT-PCR analysis was performed for nuclear receptor mRNA expression. This revealed the presence of mRNA for the androgen receptor (AR) and glucocorticoid receptor (GR). The effect of the AR agonist, dihydrotestosterone (DHT), and the GR agonist, dexamethasone (Dex), was then tested. Whilst DHT (100 nM) had no effect on FS-induced cell death, Dex (1 microM) blocked FS-induced apoptosis. Cell cycle analysis revealed that 24 h exposure to FS prevented cells from leaving G(1) and 24-48 h later a marked sub-G(1) peak was observed. Dex was able to reduce the sub-G(1) peak, but it failed to reduce accumulation of cells in G(1). Further studies revealed that, in addition to blocking FS-induced apoptosis, Dex was able to block apoptosis of EA.hy 926 cells induced by serum deprivation, tumour necrosis factor-alpha, oxidants, DNA damage and mitochondrial disruption. This study strongly suggests that glucocorticoids have a role to play in preventing vascular injury and they may provide a reason why statins are apparently not toxic to vascular endothelial cells in vivo.

Perineuronal nets in the rhesus monkey and human basal forebrain including basal ganglia

Perineuronal nets of extracellular matrix have been shown to characterize the microenvironment of individual neurons and the chemoarchitecture of brain regions such as basal forebrain nuclei. Previous work has also demonstrated that neurons in the human cerebral cortex ensheathed by perineuronal nets rarely undergo cytoskeletal changes in Alzheimer's disease, suggesting a neuroprotective effect of extracellular matrix components. It is not known, however, whether or not perineuronal nets are absent in the microenvironment of the cholinergic basal forebrain neurons that are involved early in the cascade of neurodegeneration in humans. Therefore, the present study was undertaken to examine the distribution patterns of perineuronal nets in the basal forebrain of the higher primates, rhesus monkey and human. Cytochemical staining was performed with the lectin Wisteria floribunda agglutinin and a polyclonal antibody to core proteins of chondroitin sulfate proteoglycans in the perfusion-fixed tissue of rhesus monkeys. In human brains, perineuronal nets were only stained with the immunoreaction for chondroitin sulfate proteoglycans. The results showed similar characteristics in distribution patterns of perineuronal nets in the medial septum, the diagonal band of Broca, the basal nucleus of Meynert (Ch1-Ch4), the lateral septum, the caudate-putamen, and the globus pallidus in both species. Double-labelling revealed that the vast majority of cholinergic neurons, labelled either with antibodies to choline acetyltransferase or the low-affinity neurotrophin receptor p75(NTR), were not ensheathed by perineuronal nets. A small subpopulation of net-associated neurons in close proximity to or intermingled with cholinergic neurons of the Ch1-Ch4 cell groups was found to be immunoreactive for parvalbumin. In the caudate-putamen, a large number of the parvalbumin-positive neurons were surrounded by perineuronal nets, whereas in the external and internal segments of the globus pallidus the coincidence of both markers was nearly complete. The study demonstrates that perineuronal nets of extracellular matrix are associated with different types of non-cholinergic neurons in the primate basal forebrain. The absence of nets around cholinergic basal forebrain neurons may be related to their slow modulatory activity but may also contribute to their susceptibility to degeneration in Alzheimer's disease.

Meningitis in a girl with recurrent otitis media caused by Streptococcus pyogenes--otitis media has to be treated appropriately

Streptococcus pyogenes rarely causes meningitis. A recent increase in the incidence and severity of diseases due to S. pyogenes has been observed worldwide, without an apparent increase in the incidence of S. pyogenes meningitis. However, more recently severe and fulminant cases of S. pyogenes meningitis have been reported in the literature. This case report emphasizes the fact that S. pyogenes can cause meningitis with severe clinical sequelae such as hygromas and right-sided third cranial nerve palsy. Most importantly, it is concluded that recurrent otitis media has to be treated carefully following appropriate identification of the causing organism in order to prevent severe clinical courses of streptococcal infections.

Plasticity of the synaptic contact zone following loss of synapses in the cerebral cortex of aging humans

Quantitative ultrastructural analyses of ethanolic phosphotungstic acid-stained human layer 1 precentral motor cortex (Brodmann's area 4) and layer 1 postcentral somatosensory cortex (Brodmann's area 3) were undertaken to determine the nature of synaptic changes occurring over a series of ages (45-84 years) of a normal aging human population. In the precentral cortex, a significant decrease in the number of synapses was accompanied by an increase in mean length of the postsynaptic contact zone and a decrease in the mean width of the presynaptic paramembranous density. The frequency of mature type A and immature type E synaptic profiles decreased with age. There were no changes in the width of the postsynaptic paramembranous density, cleft width or the number of presynaptic dense projections per synapse. In the postcentral cortex there were no significant changes in synaptic number or in any of the synaptic parameters measured. The present study demonstrates that age-related synapse loss in the human cerebral cortex may be confined to specific cortical regions. The data suggest that in the precentral cortex the plasticity of the synaptic contact zone may be a compensatory response by the remaining synapses to age-related synapse loss.

Comparison of synaptic changes in the precentral and postcentral cerebral cortex of aging humans: a quantitative ultrastructural study

Ultrastructural quantitative analysis was undertaken to determine whether any age-related synaptic changes occur in cortical layer 1 of the human precentral motor gyrus (Brodmann's area 4) and postcentral somatosensory gyrus (Brodmann's area 3). Immersion fixed, osmicated, uranyl acetate/lead citrate stained (OsUL) preparations of autopsied brains were taken from patients aged 45 to 84 years, with no prior history of neurological or intellectual abnormalities. In the precentral gyrus there was a significant decrease in the number of synapses, which was primarily due to a decrease in asymmetrical axospinous synapses. Symmetrical synapses remained constant in number, while axodendritic synapses showed a small increase with age. Accompanying the decline in synapse number was an increase in mean length of the postsynaptic contact zone. In the postcentral gyrus there were no significant changes in synaptic number or in any of the synaptic parameters measured. The results suggest that the motor cortex of the human brain is capable of synaptic plasticity in response to aging-induced synaptic loss. This plasticity is not apparent in the somatosensory cortex, where there is no age-related synapse loss.

Synaptic remodelling and astrocytic hypertrophy in rat cerebral cortex from early to late adulthood

Ultrastructural observation of the molecular layer of the parietal cortex of rats, aged 3, 6, 10 and 17 months, revealed various atypical synaptic profiles besides typical synapses. The atypical synapses were frequently in the vicinity of hypertrophied astrocytic profiles, and were sometimes completely surrounded by astrocytic processes. The presynaptic terminal contained either no vesicles or a few small distorted vesicles. Vacant postsynaptic terminals were occasionally seen. The total surface area of astrocytic profiles and the numbers of atypical synapses increased significantly between 3 and 10 months. The astrocytic acquisition of degenerating terminals was repeatedly observed over this period. Since there was no decrease in total synaptic number at this age, the astrocytic phenomenon may represent a stage in a continuous cycle of synaptic loss and replacement in the normal brain. By 17 months, when total synapse numbers decrease, synaptic replacement may be less than optimal.

Quantitative ultrastructural changes in rat cortical synapses during early-, mid- and late-adulthood

Quantitative ultrastructural analysis of rat parietal cortex was undertaken to determine the nature of the synaptic changes occurring in the molecular layer over a series of ages in early- (3 months), mid- (6 and 10 months) and late- (17 months) adulthood. The total number of synapses remained constant until 10 months of age, but decreased significantly by 17 months. Asymmetrical synapses on dendritic shafts were lost earlier (by 6 months) than asymmetrical synapses on dendritic spines (by 17 months). Symmetrical axodendritic synapses remained constant throughout adulthood. Analysis of synaptic terminal parameters revealed the following. Both individual and total presynaptic terminal areas decreased over the age range studied. Individual and total postsynaptic terminal areas, however, remained constant over the 3--17-month period. Positive correlations were obtained for the relationships between presynaptic terminal area and both age and synaptic vesicle number. The presynaptic terminal area was largest and contained the greatest number of vesicles at 3 months of age. This age was, in addition, characterized by the least numbers of mitochondria in the presynaptic terminal and spine apparatus in the postsynaptic terminal. The vacuolar and tubular cisternae of the presynaptic terminal were considerably reduced at 17 months. These data suggest that in the molecular layer of the cerebral cortex the period of adulthood is characterized by a diversity of synaptic changes. The 3-month age may reflect the end of the developmental phase and may be marked by changes in synaptic functional activity. The asymmetrical axodendritic synapses may constitute an intermediate form of synapse, capable of being transformed into axospinous synapses as dendritic spines continue to be formed in the adult.

The formulation and sterilization of a surgical lubricant gel based on carboxypolymethylene

A lubricant gel of optimal consistency containing a local anaesthetic (lignocaine) has been formulated which can be sterilized by gamma irradiation. A rheological specification was obtained by examination of some currently used preparations. The variation in their consistency was large but all exhibited pseudoplastic flow with a yield value. Gels based on tragacanth, the methylcelluloses and the Carbopols were suitable as lubricants before sterilization and after autoclaving, but on gamma irradiation the gel structure was destroyed. Ethanol (5–10%) protected the Carbopol formulations. Irradiation of lignocaine solutions caused some cloudiness and a small drop in pH. Ethanol and metabisulphite acted as protective agents. A final formulation was developed consisting of a Carbopol gel (1%) neutralized by lignocaine base (2%) and the biological availability of the local anaesthetic was assessed using an in vitro method.