Three critical clinicobiological phases of the human SARS-associated coronavirus infections

OBJECTIVE

COVID-19 immune syndrome is a multi-systemic disorder induced by the COVID-19 infection. Pathobiological transitions and clinical stages of the COVID-19 syndrome following the attack of SARS-CoV-2 on the human body have not been fully explored. The aim of this review is to outline the three critical prominent phase regarding the clinicogenomics course of the COVID-19 immune syndrome.

MATERIALS AND METHODS

In the clinical setting, the COVID-19 process presents as "asymptomatic/pre-symptomatic phase", "respiratory phase with mild/moderate/severe symptoms" and "multi-systemic clinical syndrome with impaired/disproportionate and/or defective immunity". The corresponding three genomic phases include the "ACE2, ANPEP transcripts in the initial phase", "EGFR and IGF2R transcripts in the propagating phase" and the "immune system related critical gene involvements of the complicating phase".

RESULTS

The separation of the phases is important since the genomic features of each phase are different from each other and these different mechanisms lead to distinct clinical multi-systemic features. Comprehensive genomic profiling with next generation sequencing may play an important role in defining and clarifying these three unique separate phases for COVID-19. From our point of view, it is important to understand these unique phases of the syndrome in order to approach a COVID-19 patient bedside.

CONCLUSIONS

This three-phase approach may be useful for future studies which will focus on the clinical management and development of the vaccines and/or specific drugs targeting the COVID-19 processes. ANPEP gene pathway may have a potential for the vaccine development. Regarding the specific disease treatments, MAS agonists, TXA127, Angiotensin (1-7) and soluble ACE2 could have therapeutic potential for the COVID-19 course. Moreover, future CRISPR technology can be utilized for the genomic editing and future management of the clinical course of the syndrome.

Immunolocalization of natriuretic peptides and their receptors in goat (Capra hircus) heart

Natriuretic peptides are structurally similar, but genetically distinct, hormones that participate in cardiovascular homeostasis by regulating blood and extracellular fluid volume and blood pressure. We investigated the distribution of natriuretic peptides and their receptors in goat (Capra hircus) heart tissue using the peroxidase-anti-peroxidase (PAP) immunohistochemical method. Strong staining of atrial natriuretic peptide (ANP) was observed in atrial cardiomyocytes, while strong staining for brain natriuretic peptide (BNP) was observed in ventricular cardiomyocytes. Slightly stronger cytoplasmic C-type natriuretic peptide (CNP) immunostaining was detected in the ventricles compared to the atria. Natriuretic peptide receptor-A (NPR-A) immunoreactivity was more prominent in the atria, while natriuretic peptide receptor-B (NPR-B) immunoreactivity was stronger in the ventricles. Cytoplasmic natriuretic peptide receptor-C (NPR-C) immunoreactivity was observed in both the atria and ventricles, although staining was more prominent in the ventricles. ANP immunoreactivity ranged from weak to strong in endothelial and vascular smooth muscle cells. Endothelial cells exhibited moderate to strong BNP immunoreactivity, while vascular smooth cells displayed weak to strong staining. Endothelial cells exhibited weak to strong cytoplasmic CNP immunoreactivity. Vascular smooth muscle cells were labeled moderately to strongly for CNP. Weak to strong cytoplasmic NPR-A immunoreactivity was found in the endothelial cells and vascular smooth muscle cells stained weakly to moderately for NPR-A. Endothelial and vascular smooth cells exhibited weak to strong cytoplasmic NPR-B immunoreactivity. Moderate to strong NPR-C immunoreactivity was observed in the endothelial and smooth muscle cells. Small gender differences in the immunohistochemical distribution of natriuretic peptides and receptors were observed. Our findings suggest that endothelial cells, vascular smooth cells and cardiomyocytes express both natriuretic peptides and their receptors.

Spontaneous retroperitoneal hemorrhage presenting as hemoperitoneum secondary to renal cyst rupture in a peritoneal dialysis patient with acquired cystic kidney disease

Spontaneous retroperitoneal hemorrhage (SRH) is a rare and potentially fatal condition. Acquired cystic kidney disease (ACKD) may cause SRH in hemodialysis patients. However, presentation of retroperitoneal hematoma as hemoperitoneum in peritoneal dialysis (PD) patients is exceedingly rare. We report a 44-year-old male PD patient who presented with hemoperitoneum secondary to retroperitoneal hematoma. The reason of SRH was rupture of the cysts of ACKD. The patient underwent unilateral nephrectomy with subsequent disappearance of hemoperitoneum. The importance of this case lies in the fact that the patients who have been receiving dialysis for a long time should be under surveillance in terms of ACKD development and potential associated complications such as cyst hemorrhage and malignancy.

Antifungal activity of cinnamic acid derivatives involves inhibition of benzoate 4-hydroxylase (CYP53)

AIMS

CYP53A15, from the sorghum pathogen Cochliobolus lunatus, is involved in detoxification of benzoate, a key intermediate in aromatic compound metabolism in fungi. Because this enzyme is unique to fungi, it is a promising drug target in fungal pathogens of other eukaryotes.

METHODS AND RESULTS

In our work, we showed high antifungal activity of seven cinnamic acid derivatives against C. lunatus and two other fungi, Aspergillus niger and Pleurotus ostreatus. To elucidate the mechanism of action of cinnamic acid derivatives with the most potent antifungal properties, we studied the interactions between these compounds and the active site of C. lunatus cytochrome P450, CYP53A15.

CONCLUSION

We demonstrated that cinnamic acid and at least four of the 42 tested derivatives inhibit CYP53A15 enzymatic activity.

SIGNIFICANCE AND IMPACT OF THE STUDY

By identifying selected derivatives of cinnamic acid as possible antifungal drugs, and CYP53 family enzymes as their targets, we revealed a potential inhibitor-target system for antifungal drug development.

Evaluation of echocardiographic indices for the prediction of major adverse events during long-term follow-up in chronic hemodialysis patients with normal left ventricular ejection fraction

BACKGROUND

Cardiovascular disease is the leading cause of mortality in endstage renal failure. Prognostic role of echocardiography has not been fully elucidated in chronic hemodialysis patients.

AIM

To assess the ability of Doppler echocardiographic parameters of left ventricular (LV) diastolic function along with conventional echocardiographic indices to predict long-term adverse major events in chronic hemodialysis patients with normal LV ejection fraction (EF).

PATIENTS AND METHODS

A total of 45 chronic hemodialysis patients (aged 49 +/- 15 years) were included to the study. All patients underwent complete standard and tissue Doppler imaging echocardiography before and immediately after hemodialysis session and were followed-up prospectively. Major outcome measure was the combination of all-cause death and hospitalization for any cardiovascular event.

RESULTS

During the follow up period (52 +/- 26 months) 23 major events occured (17 all-cause deaths and 6 cardiovascular events requring hospitalization). Post-dialytic values of mean left atrial diameter, mitral E (peak early mitral inflow velocity), E/Vp [ratio of mitral E to flow propagation velocity (Vp)] and E/Ea [ratio of mitral E to peak early diastolic mitral annular velocity (Ea)] (average of 4 segments of mitral annulus) were significantly higher in patients who had major events. In Cox proportional hazard analysis only E/Ea ratio predicted combined endpoint of all-cause mortality and nonfatal cardiovascular events (hazard ratio: 1.20; confidence interval: 1.03-1.39; p = 0.018). The optimum cut-off value for E/Ea determined by ROC curve analysis revealed that E/Ea ratio higher than 9.8 predicted future events with sensitivity of 74% and specificity of 86%.

CONCLUSIONS

E/Ea might be an accurate echocardiographic indice during long-term follow up for the prediction of major adverse events in chronic hemodialysis patients with normal LV EF.

Aspergillus thyroiditis in a renal transplant recipient mimicking subacute thyroiditis

Fungal pathogens are increasingly encountered after renal transplantation. Aspergillus causes significant morbidity and mortality in transplant patients. Fungal thyroiditis is a rare occurrence owing to unique features of the thyroid gland. Most cases are caused by Aspergillus species and have been described in immunocompromised patients. Presentation may be identical with that of subacute thyroiditis, in which hyperthyroidism features and painful thyroid are the prominent findings. Diagnosis can be ascertained by fine-needle aspiration of thyroid showing branching hyphae of Aspergillus. We describe a renal transplant patient who developed Aspergillus thyroiditis as part of a disseminated infection successfully treated with voriconazole.

Successful Peritoneal Dialysis in a Hemophilia a Patient with Factor VIII Inhibitor

Chronic kidney disease and need for renal replacement therapy in hemophiliacs are relatively rare occurrences. Successful hemodialysis and peritoneal dialysis applications have been reported in the literature. We report a difficult-to-manage patient with hemophilia A plus factor VIII inhibitor who presented with gastrointestinal bleeding complicated by uremia. We admitted this hemophilia A patient with gastrointestinal bleeding who did not take regular factor infusions. He also had chronic kidney disease due to urinary stone disease. Since uremia might have contributed to bleeding, we chose hemodialysis along with factor VIII supplementation. His factor VIII and factor VIII inhibitor levels were 4% and 5 Bethesda units respectively. In order to bypass the inhibitor, we applied factor VIIA and prothrombin complex concentrate. After cessation of the hemorrhage, we placed a Tenckhoff catheter under prothrombin complex concentrate infusion. We did not observe any perioperative complication. To our knowledge, this is the first report of successful peritoneal dialysis in a hemophilia A patient who had factor VIII inhibitors.

Optimization of melt pelletization in a high shear mixer

The effects of process conditions and binder content on the process yield and pellet characteristics of two formulations prepared by melt pelletization in a laboratory-type high shear mixer were investigated. The formulations were prepared using Gelucire 50/13 and Lutrol F68 as meltable binders. The factors under investigation were impeller speed, mixing time, mixer load, binder concentration, and their reciprocal interactions. Analysis of variance (ANOVA) was used in order to study the significance of above mentioned process variables on the useful yield. Twenty-seven experiments were required for the response surface methodology based on Box-Behnken experimental design (24 combinations with three replications of the centre point) for each formulation. The control over the process and the quality of the resulting pellets were found to depend on the rheological properties of the binders used. In the case of a low viscosity binder (Gelucire 50/13), the process was easily controllable whereas in the case of a high viscosity binder (Lutrol F68), the process was more difficult to control. The useful yield of the formulation in the case of the low viscosity binder was found to be mostly influenced by the concentration of the binder. On the other hand, different binder concentrations did not affect the useful yield of the formulation prepared by use of the high viscosity binder. In the latter case, mixing time was identified as the variable that mostly influenced the pelletization process. Finally response surface methodology was applied to find the optimum values of the process variables.

Treatment with antidepressive drugs improved quality of life in chronic hemodialysis patients

BACKGROUND

Despite some improvements in dialysis therapies, depression still remains an important problem in chronic hemodialysis (HD) patients. In this study, we aimed to investigate the association of depression and its treatment with quality of life (QOL) in HD patients.

PATIENTS AND METHODS

97 HD patients (52 male, 45 female, mean age 55 +/- 16 years) were enrolled. All patients had been dialyzed for more than 6 months. In order to evaluate QOL of the patients, a short form of Medical Outcomes Study (SF-36) was used. Depression was assessed by using Beck Depression Inventory (BDI). Patients who had BDI score > or = 15 were diagnosed as to have depression. Patients with depression received antidepressive treatment (sertralin HCl, 50 mg/day) for an 8-week period. After 8-week antidepressive treatment, all biochemical analysis, SF-36 and BDI were performed again.

RESULTS

40 patients (20 male, 20 female, mean age 56 +/- 14 years) had depression. All parameters related to QOL were significantly decreased in patients with depression as compared to patients without depression. Severity of depression was correlated with QOL parameters. After 8 weeks of treatment, as parallel to changes in BDI, QOL parameters improved in patients with depression.

CONCLUSION

Decrease in QOL, associated with depression and antidepressive treatment, improves QOL in HD patients. Hemodialysis patients should be followed-up closely for presence of depression. Treatment of depression with antidepressive drug regimen would lead to relieve the symptoms related to depression and improvement of QOL in these patients. Antidepressive treatment should be required more often than we prescribe in routine clinical practice now.

Application of experimental design methodology in development and optimization of drug release method

The aim of our research was to apply experimental design methodology in the development and optimization of drug release methods. Diclofenac sodium (2-[(2,6-dichlorophenyl)amino]benzeneacetic acid monosodium salt) was selected as a model drug and Naklofen retard prolonged release tablets, containing 100 mg of diclofenac sodium, were chosen as a model prolonged release system. On the basis of previous results, a three-level three-factorial Box-Behnken experimental design was used to characterize and optimize three physicochemical parameters, i.e. rotation speeds of the stirring elements, pH, and ionic strengths of the dissolution medium, affecting the release of diclofenac sodium from the tablets. The chosen dependent variables (responses) were a cumulative percentage of dissolved diclofenac sodium in 2, 6, 12 and 24 h. For estimation of coefficients in the approximating polynomial function, the least square regression method was applied. Afterwards, the information about the model reliability was verified by using the analysis of variance (ANOVA). The estimation of model factors' significance was performed by Student's t-test. For investigation of the shape of the predicted response surfaces and for model optimization, the canonical analysis was applied. Our study proved that experimental design methodology could efficiently be applied for characterization and optimization of analytical parameters affecting drug release and that it is an economical way of obtaining the maximum amount of information in a short period of time and with the fewest number of experiments.

Assessment of acute renal failure patients treated in our nephrology clinic between 1996 and 2002

Acute renal failure (ARF) is a cause of high morbidity and mortality associated with long hospital stay, and expensive treatment. The initial approach to patients with ARF should be focused on preventing future injury to the kidney. Two hundred eighty-three ARF patients, treated from January 1996 to June 2002, were retrospectively investigated for their etiology, clinic features, and laboratory characteristics, as well as treatment results and mortality rate. The mean age was 52.3 +/- 18.7 years. Patients with hospital-acquired ARF comprised 38.8% of the sample. Renal causes (60%) were responsible for most ARF patients. They were medical (63.95%), surgical (23.67%), and obstetric (12.4%) causes. Twenty-five percent of patients with ARF had multiple etiologies. Hemolysis elevated liver enzymes low platelets (HELLP) syndrome was seen in the most of the obstetric-related ARF cases. Signs of hypervolemia were present in approximately 50% of the cases. Oliguric patients comprised 59.7% of the sample, and the mean time to oliguria was 5.2 +/- 4.1 days. The necessity of dialysis was greater in oliguric patients (42.6%) and the ratio of complete/partial improvement (82.2%) was greater among non-oligoanuric patients. However, there was no significant difference between mortality rates. Irreversible renal insufficiency did not develop in the non-oliguric cases. Also, 7.4% of ARF patients died, with the main causes being infection (31.8%) and cardiovascular events (27.2%). Medical problems are important in the etiology of ARF as well as obstetric cases. The mortality rate was low in our cases, a situation that may be explained by medical causes being of importance in the etiology. We are of the opinion that early referral of patients to a nephrologist and following treatment in the nephrology clinic may positively affect the outcome.

Use of statins in primary and secondary prevention of coronary heart disease and ischemic stroke. Meta-analysis of randomized trials

OBJECTIVE

To estimate the relative risk reduction of the clinical outcomes (coronary events, strokes, cardiovascular, non-cardiovascular and all-cause mortality) associated with statin therapy in primary and secondary prevention.

DATA SOURCES

A literature search of the Medline and Cohrane databases for articles published from 1985 to July 2002 was performed. The data on systematic reviews and preliminary reports were also included in this study. Primary and secondary prevention trials and regression trials were eligible. DATA EXTRACTION AND STATISTICAL METHOD: Data were extracted by 2 authors according to the defined inclusion criteria. Disagreements were resolved by consensus or by a third reviewer. Testing for heterogeneity was applied and on the basis of these results a fixed effect model or a random effect model was used for calculation of relative risk values (RR) and 95% confidence intervals (95% CI). Sensitivity analysis tested the impact of the individual study--duration of study, type of statin therapy and study size. The number of patients needed to treat was calculated as an absolute measure of clinical effectiveness of statin therapy when appropriate.

RESULTS

Data from 15 trials with 63,410 participants and mean duration of treatment of 3.6 years, were included in this overview. Tests for heterogeneity showed that the variability between study estimates is sufficiently small to assume that they are estimating the same underlying treatment effect. Statin therapy was associated with a 22% reduction in total cholesterol, 29% reduction in LDL cholesterol, 12% reduction in triglycerides and 6% increase in HDL cholesterol. Overall (primary and secondary studies) statin therapy significantly reduces relative risk of coronary events (RR, 0.73, 95% CI, 0.68, 0.77, *p < 0.0001), relative risk of cardiovascular disease mortality (RR, 0.78, 95% CI, 0.73, 0.84, *p < 0.0001), relative risk of non-fatal stroke (RR, 0.74, 95% CI, 0.67, 0.82, *p < 0.0001), relative risk of total (fatal and non-fatal) stroke (RR, 0.77, 95% CI, 0.70, 0.84, *p < 0.001) and relative risk of all-cause death (RR, 0.85, 95% CI, 0.81, 0.89, *p < 0.0001). There was a slight and insignificant reduction of relative risk in non-cardiovascular mortality (RR, 0.94, 95% CI, 0.86, 1.03, p = 0.1677) and fatal strokes (RR, 0.86, 95% CI, 0.70, 1.07, p = 0.1912). Sensitivity analysis showed the robustness of our results for all outcomes. The results were not altered if an individual study was removed from meta-analysis.

CONCLUSIONS

This overview indicates that statin treatment reduces the relative risk of occurrence of coronary events, cardiovascular disease mortality, non-fatal strokes and all-cause mortality. While secondary prevention with statins provides considerable improvement of cardiovascular morbidity/mortality, primary prevention with statins provides only small and clinically hardly relevant improvement of cardiovascular morbidity/mortality.

Statistical optimisation of diclofenac sustained release pellets coated with polymethacrylic films

The objective of the present study was to evaluate three formulation parameters for the application of polymethacrylic films from aqueous dispersions in order to obtain multiparticulate sustained release of diclofenac sodium. Film coating of pellet cores was performed in a laboratory fluid bed apparatus. The chosen independent variables, i.e. the concentration of plasticizer (triethyl citrate), methacrylate polymers ratio (Eudragit RS:Eudragit RL) and the quantity of coating dispersion were optimised with a three-factor, three-level Box-Behnken design. The chosen dependent variables were cumulative percentage values of diclofenac dissolved in 3, 4 and 6 h. Based on the experimental design, different diclofenac release profiles were obtained. Response surface plots were used to relate the dependent and the independent variables. The optimisation procedure generated an optimum of 40% release in 3 h. The levels of plasticizer concentration, quantity of coating dispersion and polymer to polymer ratio (Eudragit RS:Eudragit RL) were 25% w/w, 400 g and 3/1, respectively. The optimised formulation prepared according to computer-determined levels provided a release profile, which was close to the predicted values. We also studied thermal and surface characteristics of the polymethacrylic films to understand the influence of plasticizer concentration on the drug release from the pellets.

Signal transduction in the Rhizobium meliloti dicarboxylic acid transport system

The gene products of the Rhizobium meliloti dctB and dctD genes, which control the expression of the C4-dicarboxylic acid transporter DctA, were overproduced in Escherichia coli and purified. The purified sensor protein, DctB, was shown to have autophosphorylation activity in vitro and could subsequently phosphorylate the transcriptional activator, DctD. The presence of C4-dicarboxylic acids did not affect either reaction. In vitro experiments aimed at investigating 'crosstalk' between cognate components demonstrated that the phospho-transfer activity was specific between DctB and DctD. Studies on truncated versions of the DctB protein in vitro revealed that the cytoplasmic domain of DctB had strong autophosphorylation activity. Data from gel retardation experiments demonstrated that once the activator protein, DctD, was phosphorylated it had increased affinity for binding to the dctA promoter DNA.