Distribution of Virulence Genes among Enterococcus species Isolated from Patients of Urinary Tract Infection Attended in a Tertiary Care Hospital of Bangladesh

Enterococcus species was frequently considered to be commensal organisms but last few decades it has emerged as an important cause of health care associated infections. The presence of virulent genes is one of a key factor for which Enterococcus spp. is gaining attention. In this study, we aim to determine the frequency of virulence genes in uropathogenic Enterococcus species. A total of 46 Enterococcus strains isolated from January 2017 to December 2017. Urine samples were collected from adult clinically suspected urinary tract infected patients from the inpatient and outpatient department of Dhaka Medical College Hospital, Bangladesh irrespective of sex and antibiotic intake. Potential virulence genes such as asa, esp, ace, ebp, cyl, gelE, pilA, pilB, sprE, scm, fms8, ecbA and hyl were detected by PCR using specific primers. Among 46 culture positive Enterococcus, 33(71.74%) were E. faecalis, 11(23.91%) were E. faecium, 2(4.35%) were unidentified. Of the 44 identified Enterococci (33 E. faecalis and 11 E. faecium), 43(97.73%) were positive for pilB, 41(93.18%) for both scm and fms8, 39(88.64%) were positive for ebp, 34(77.27%) for gelE, 32(72.78%) for esp, 31(70.45%) for ecbA, 30(68.18%) for sprE, 28(63.67%) for pilA, 25(56.82%) for ace, 21(47.73%) for cyl, 20(45.45%) for asa and 3(6.82%) for hyl gene. Different virulence factors could be associated with the pathogenicity of E. faecalis and E. faecium and these genes are extensively available among the Enterococcus species.

Role of the redox state of the Pirin-bound cofactor on interaction with the master regulators of inflammation and other pathways

Persistent cellular stress induced perpetuation and uncontrolled amplification of inflammatory response results in a shift from tissue repair toward collateral damage, significant alterations of tissue functions, and derangements of homeostasis which in turn can lead to a large number of acute and chronic pathological conditions, such as chronic heart failure, atherosclerosis, myocardial infarction, neurodegenerative diseases, diabetes, rheumatoid arthritis, and cancer. Keeping the vital role of balanced inflammation in maintaining tissue integrity in mind, the way to combating inflammatory diseases may be through identification and characterization of mediators of inflammation that can be targeted without hampering normal body function. Pirin (PIR) is a non-heme iron containing protein having two different conformations depending on the oxidation state of the iron. Through exploration of the Pirin interactome and using molecular docking approaches, we identified that the Fe2+-bound Pirin directly interacts with BCL3, NFKBIA, NFIX and SMAD9 with more resemblance to the native binding pose and higher affinity than the Fe3+-bound form. In addition, Pirin appears to have a function in the regulation of inflammation, the transition between the canonical and non-canonical NF-κB pathways, and the remodeling of the actin cytoskeleton. Moreover, Pirin signaling appears to have a critical role in tumor invasion and metastasis, as well as metabolic and neuro-pathological complications. There are regulatory variants in PIR that can influence expression of not only PIR but also other genes, including VEGFD and ACE2. Disparity exists between South Asian and European populations in the frequencies of variant alleles at some of these regulatory loci that may lead to differential occurrence of Pirin-mediated pathogenic conditions.

TTN as a candidate gene for distal arthrogryposis type 10 pathogenesis

Background

Arthrogryposis is a medical term used to describe congenital contractures which often affect multiple limbs. Distal arthrogryposis (DA) is one of the major categories of arthrogryposis that primarily affects the distal parts of the body, i.e., the hands and the legs. Although ten different types and several subtypes of DAs have been described, the genes associated with each of these DAs are yet to be characterized. Distal arthrogryposis type 10 (DA10) is a rare genetic disease, which is distinguished from the other arthrogryposis types by plantar flexion contractures resulting in toe-walking during infancy as well as variability in contractures of the hip, hamstring, elbow, wrist and finger joints with no ocular or neurological abnormalities. Symptoms of DA10 indicate impairment specifically in the musculoskeletal system. DA10 is still poorly studied.

Aim

The objective of this study was to identify the candidate gene for DA10 by scrutinizing the protein-protein interaction (PPI) networks using in silico tools.

Results

Among the genes that reside within the previously reported genomic coordinates (human chromosome assembly 38 or GRCh38 coordinates 2:179,700,000–188,500,000) of the causative agent of DA10, only TTN (the gene that codes for the protein Titin or TTN) follows the expression pattern similar to the other known DA associated genes and its expression is predominant in the skeletal and heart muscles. Titin also participates in biological pathways and processes relevant to arthrogryposes. TTN-related known skeletal muscle disorders follow the autosomal-dominant pattern of inheritance, which is a common characteristic of distal arthrogryposes as well.

Conclusion

Based on the findings of the analyses and their correlation with previous reports, TTN appears to be the candidate gene for DA10. Our attempt to discover a potential candidate gene may eventually lead to an understanding of disease mechanism and possible treatment strategies, as well as demonstrate the suitability of PPI in the search for candidate genes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s43141-022-00405-5.

A comprehensive in silico exploration of the impacts of missense variants on two different conformations of human pirin protein

BACKGROUND

Pirin, a member of the cupin superfamily, is an iron-binding non-heme protein. It acts as a coregulator of several transcription factors, especially the members of NFκB transcription factor family. Based on the redox state of its iron cofactor, it can assume two different conformations and thereby act as a redox sensor inside the nucleus. Previous studies suggested that pirin may be associated with cancer, inflammatory diseases as well as COVID-19 severities. Hence, it is important to explore the pathogenicity of its missense variants. In this study, we used a number of in silico tools to investigate the effects of missense variants of pirin on its structure, stability, metal cofactor binding affinity and interactions with partner proteins. In addition, we used protein dynamics simulation to elucidate the effects of selected variants on its dynamics. Furthermore, we calculated the frequencies of haplotypes containing pirin missense variants across five major super-populations (African, Admixed American, East Asian, European and South Asian).

RESULTS

Among a total of 153 missense variants of pirin, 45 were uniformly predicted to be pathogenic. Of these, seven variants can be considered for further experimental studies. Variants R59P and L116P were predicted to significantly destabilize and damage pirin structure, substantially reduce its affinity to its binding partners and alter pirin residue fluctuation profile via changing the flexibility of several key residues. Additionally, variants R59Q, F78V, G98D, V151D and L220P were found to impact pirin structure and function in multiple ways. As no haplotype was identified to be harboring more than one missense variant, further interrogation of the individual effects of these seven missense variants is highly recommended.

CONCLUSIONS

Pirin is involved in the transcriptional regulation of several genes and can play an important role in inflammatory responses. The variants predicted to be pathogenic in this study may thus contribute to a better understanding of the underlying molecular mechanisms of various inflammatory diseases. Future studies should be focused on clarifying if any of these variants can be used as disease biomarkers.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1186/s42269-022-00917-7.

Missense variants in the TNFA epitopes and their effects on interaction with therapeutic antibodies-in silico analysis

BACKGROUND

Tumor necrosis factor alpha (TNFA) is an important cytokine that influences multiple biological processes. It is one of the key mediators of acute and chronic systemic inflammatory reactions and plays a central role in several autoimmune diseases. A number of approved monoclonal antibodies (mAbs) are widely used to subside these autoimmune diseases. However, there is a high rate of non-responsiveness to treatments with these mAbs. Therefore, it is important to be able to predict responses of the patients in an individualistic manner to these therapeutic antibodies before administration. In the present study, we used in silico tools to explore the effects of missense variants in the respective epitopes of four therapeutic anti-TNFA mAbs-adalimumab (ADA), certolizumab pegol (CZP), golimumab (GLM), and infliximab (IFX)-on their interactions with TNFA.

RESULTS

The binding affinities of CZP and ADA to corresponding epitopes appear to be reduced by four (TNFAR131Q, TNFAE135G, TNFAR138Q, and TNFAR138W) and two (TNFAG66C and TNFAG66S) variants, respectively. The binding of GLM and IFX appears to be affected by TNFAR141S and TNFAR138W, respectively. TNFAG66C and TNFAG66S may be associated with autoimmune diseases, whereas TNFAE135G, TNFAR138W, and TNFAR141S may be pathogenic per se.

CONCLUSION

These variants may contribute to the observed inter-individual variability in response to anti-TNFA mAbs treatments and be used as markers to predict responses, and thus optimize therapeutic benefits to the patients.

Effects of arsenic and heavy metals on metabolic pathways in cells of human origin: Similarities and differences

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There are distinctive overlaps in different heavy metal affected metabolic pathways.

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Affected pathways vary according to the tissue origin and maturity of the cell.

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Arsenic appears to have relatively more pleiotropic effects on metabolic pathways.

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Some of the arsenic affected pathways are associated with diabetes.

Various anthropogenic and natural events over the years have gradually increased human exposure to various heavy metals. Several of these heavy metals including cadmium, mercury, nickel, chromium, and the metalloid arsenic among others, have created major public health concerns for their high level of toxicities. Identification of the general as well as the differentially affected cellular metabolic pathways will help understanding the molecular mechanism of different heavy metal-induced toxicities. In this study, we analyzed 25 paired (control vs. treated) transcriptomic datasets derived following treatment of various human cells with different heavy metals and metalloid (arsenic, cadmium, chromium, iron, mercury, nickel and vanadium) to identify the affected metabolic pathways. The effects of these metals on metabolic pathways depend not only on the metals per se, but also on the nature of the treated cells. Tissue of origin, therefore, must be considered while assessing the effects of any particular heavy metal or metalloid. Among the metals and metalloid, arsenic appears to have relatively more pleiotropic influences on cellular metabolic pathways including those known to have association with diabetes. Although only two stem cell derived datasets are included in the current study, effects of heavy metals on these cells appear to be different from other mature cells of similar tissue origin. This study provides useful information about different heavy metal affected pathways, which may be useful in further exploration using wet-lab based techniques.

Disparities in COVID-19 severities and casualties across ethnic groups around the globe and patterns of ACE2 and PIR variants

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) mediated Coronavirus disease-19 (COVID-19) has affected millions of individuals around all corners of the globe. Symptoms and severities of infection with this highly contagious virus vary among individuals and there is disparity in the number of COVID-19-related casualties across different ethnic groups. The primary receptor for SARS-CoV-2 entry into the host cells is angiotensin-converting enzyme 2 (ACE2). Certain variants of ACE2 are known to be associated with COVID-19 comorbidities such as hypertension, cardiovascular complications, diabetes, chronic lung disease, etc. In this study, we looked into the geographic distribution of disease-associated variants of ACE2 as well as closely located PIR gene to explore any possible correlation with the disparities in COVID-19 severities and casualties across ethnic groups. Frequencies of the ACE2 variants associated with COVID-19 comorbidities are higher in the European and the admixed American populations. These variants are also present with stronger pairwise linkage disequilibrium (LD) in the European and the admixed American populations. On the other hand, the variants with protective role are more prevalent in the East and the South Asian populations. Strong pairwise LD exists among the activity modifying (modifier) variants of the PIR and ACE2 genes only in the European super-population. Absence of these PIR variants in the South Asian population may contribute to the overall lower COVID-19 case fatality rates (CFR) despite the dense population in this region.

Repurposing of approved drugs with potential to interact with SARS-CoV-2 receptor

Respiratory transmission is the primary route of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection. Angiotensin I converting enzyme 2 (ACE2) is the known receptor of SARS-CoV-2 surface spike glycoprotein for entry into human cells. A recent study reported absent to low expression of ACE2 in a variety of human lung epithelial cell samples. Three bioprojects (PRJEB4337, PRJNA270632 and PRJNA280600) invariably found abundant expression of ACE1 (a homolog of ACE2 and also known as ACE) in human lungs compared to very low expression of ACE2. In fact, ACE1 has a wider and more abundant tissue distribution compared to ACE2. Although it is not obvious from the primary sequence alignment of ACE1 and ACE2, comparison of X-ray crystallographic structures show striking similarities in the regions of the peptidase domains (PD) of these proteins, which is known (for ACE2) to interact with the receptor binding domain (RBD) of the SARS-CoV-2 spike protein. Critical amino acids in ACE2 that mediate interaction with the viral spike protein are present and organized in the same order in the PD of ACE1. In silico analysis predicts comparable interaction of SARS-CoV-2 spike protein with ACE1 and ACE2. In addition, this study predicts from a list of 1263 already approved drugs that may interact with ACE2 and/or ACE1 and potentially interfere with the entry of SARS-CoV-2 inside the host cells.

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Peptidase domains (PD) of ACE1 and ACE2 have striking similarities.

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In silico analysis predicts comparable interactions of S protein with ACE1 and ACE2.

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Several approved drugs may be repurposed to interfere with SARS-CoV-2 binding.

Retroperitoneal Lymphangioma in Adult: A Case Report

Lymphangioma is a rare, benign tumour occurring due to congenital malformation of the lymphatic channels. It occurs due to obstruction in the lymphatic channel and results in lymphangiectasia. The tumour is most commonly encountered in the head and neck regions and almost 90% are in the children below the age of 2 years. Retroperitoneal Lymphangioma in an adult is a rare clinical condition. We have presented a 41 year old female with retroperitoneal lymphangioma who came to Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh on 10 October 2017 with the non-specific complains of upper abdominal discomfort, occasional nausea, vomiting and aorexia for the last 1.5 years. She was managed surgically by exploratory laparotomy followed by de-roofing of the cyst. Histopathological examination of the cyst wall was consistent with lymphangioma.

Aspartame, acesulfame K and sucralose- influence on the metabolism of Escherichia coli

Gut microbes play a crucial role in the maintenance of human health. Components in the diet of the host affect their metabolism and diversity. Here, we investigated the influences of three commonly used non-caloric artificial sweeteners-aspartame, acesulfame K and sucralose-on the growth and metabolism of an omnipresent gut microbe Escherichia coli K-12. Methods: Growth of E. coli in the presence of aspartame, acesulfame K and sucralose in media was assessed and the influences of these artificial sweeteners on metabolism were investigated by relative expression analysis of genes encoding the rate limiting steps of important metabolic pathways as well as their global metabolomic profiles. Results: As a whole, E. coli growth was inhibited by aspartame and induced by acesulfame potassium, while the effect of sucralose on growth was less prominent. Although the expressions of multiple key enzymes that regulate important metabolic pathways were significantly altered by all three sweeteners, acesulfame K caused the most notable changes in this regard. In multivariate analysis with the metabolite profiles, the sucralose-treated cells clustered the closest to the untreated cells, while the acesulfame potassium treated cells were the most distant. These sweeteners affect multiple metabolic pathways in E. coli, which include propanoate, phosphonate, phosphinate and fatty acid metabolism, pentose phosphate pathway, and biosynthesis of several amino acids including lysine and the aromatic amino acids. Similar to the gene expression pattern, acesulfame potassium treated E. coli showed the largest deviation in their metabolite profiles compared to the untreated cells.

Role of Laparoscopic Appendicectomy in the Treatment of Acute Appendicitis and Its Complications

The aim of this prospective study was to evaluate the role and application of laparoscopy in the management of acute appendicitis and its complications. The study was conducted between January 2011 to February 2019 in Bangabandhu Sheikh Mujib Medical University (BSMMU) and some private hospitals of Dhaka, Bangladesh. A total of 641 patients who presented with acute appendicitis and its complications were treated by laparoscopic method. Around 70% (449) patients had classical presentation, 20% (128) were atypical and 10% (64) were recurrent or chronic presentation. Maximum (527, 82%) came with acute appendicitis. Eighty eight (13.72%) patients had burst (perforated) appendicitis, 12(1.87%) patients had appendicular abscess, 11(1.71%) showed early appendicular lump, 2(0.4%) had stump appendicitis and 1(0.2%) had previous laparoscopic clip control of stump. Energy source was unipolar diathermy. Intracorporeal knotting, endoloop and haemoclip were used for haemostosis and ligation of appendicular stump. Mean duration of surgery was 20minutes and mean hospital stay was 36 hours. Histopathological patterns were acute appendicitis (554, 86.42%), gangrenous appendicitis (58, 9.04%), catarrhal (13, 2.02%), chronic appendicitis (10, 1.56%) lymphoid hyperplasia (6, 0.93%) and carcinoid tumor (1, 0.15%), among the complications (25) were single or multiple port infections, port TB, paralytic ileus and diarrhea. Conversion was 1(0.15%) for controlling haemorrhage of burst appendicitis. The rest of the patients recovered quickly and uneventfully. In conclusion, it can be stated that laparoscopic appendicectomy is safe, convenient and achievable and can become the gold standard of management of acute appendicitis and its complications.

Heterogeneity in the distribution of 159 drug-response related SNPs in world populations and their genetic relatedness

Interethnic variability in drug response arises from genetic differences associated with drug metabolism, action and transport. These genetic variations can affect drug efficacy as well as cause adverse drug reactions (ADRs). We retrieved drug-response related single nucleotide polymorphism (SNP) associated data from databases and analyzed to elucidate population specific distribution of 159 drug-response related SNPs in twenty six populations belonging to five super-populations (African, Admixed Americans, East Asian, European and South Asian). Significant interpopulation differences exist in the minor (variant) allele frequencies (MAFs), linkage disequilibrium (LD) and haplotype distributions among these populations. 65 of the drug-response related alleles, which are considered as minor (variant) in global population, are present as the major alleles (frequency ≥0.5) in at least one or more populations. Populations that belong to the same super-population have similar distribution pattern for majority of the variant alleles. These drug response related variant allele frequencies and their pairwise LD measure (r²) can clearly distinguish the populations in a way that correspond to the known evolutionary history of human and current geographic distributions, while D' cannot. The data presented here may aid in identifying drugs that are more appropriate and/or require pharmacogenetic testing in these populations. Our findings emphasize on the importance of distinct, ethnicity-specific clinical guidelines, especially for the African populations, to avoid ADRs and ensure effective drug treatment.

Use of p-nitrobenzoic acid in 7H10 agar for identification of Mycobacterium tuberculosis complex: a field study

We report the efficiency and cost-effectiveness of p-nitrobenzoic acid (PNB) testing in Middlebrook 7H10 agar medium for the identification of Mycobacterium tuberculosis complex (MTC). PNB-7H10 was compared with PNB-MGIT and BACTEC-NAP using 200 clinical mycobacterial isolates. PNB-7H10 showed 100% agreement with PNB-MGIT and BACTEC-NAP tests, and reduced the cost of PNB-MGIT test by 80%. PNB-7H10 agar is therefore an effective alternative to the costly PNB-MGIT and BACTEC-NAP tests, especially in resource-poor settings.

Metallo-beta-lactamase-producing clinical isolates of Acinetobacter species and Pseudomonas aeruginosa from intensive care unit patients of a tertiary care hospital

Prompt detection of metallo-beta-lactamase (MBL) producing isolates is necessary to prevent their dissemination. Frequency of MBLs producing strains among multidrug resistant (MDR) Acinetobacter species and Pseudomonas aeruginosa was evaluated in critical care patients using imipenem-EDTA disk method. One hundred MDR Acinetobacter spp. and 42 Pseudomonas aeruginosa were checked for MBL production, from January to June 2001. MBL was produced by 96.6 % of imipenem-resistant Acinetobacter isolates, whereas 100% imipenem-resistant Pseudomonas aeroginosa isolates were MBL producers. Carbapenem resistance in MDR Acinetobacter spp. and Pseudomonas aeruginosa isolates in this study was due to MBLs. This calls for strict infection control measures to prevent further dissemination.

Bioengineered tissues: the science, the technology, and the industry

OBJECTIVE

The bioengineering of tissues and organs, sometimes called tissue engineering and at other times regenerative medicine, is emerging as a science, as a technology, and as an industry. The goal is the repair, replacement, and/or the regeneration of tissues and organs. The objective of this paper is to identify and discuss the major issues that have become apparent.

RESULTS

One of the critical issues is that of cell source, i.e. what will be the source of the cells to be employed? Another critical issue is the development of approaches for the fabrication of substitute tissues/organs and/or vehicles for the delivery of biological active molecules for use in the repair/regeneration of tissues. A third critical issue, one very much related to cell source, is that of immune acceptance. In addition, there are technological hurdles; there are additional issues such as the scale-up of manufacturing processes and the preservation of living-cell products for off-the-shelf availability. Although the initial products have been superficially applied skin substitutes, as this fledgling industry continues to evolve, it is beginning to focus on a wider range of more invasive and complicated products. From a public health perspective, the real opportunity may be in addressing chronic diseases, as well as the transplantation crisis (i.e. the tremendous disparity between patient need for vital organs and donor availability) and, equally important is the challenge of neural repair.

CONCLUSION

These are the grand challenges, and the scientific community, business/private sector, and federal government must mobilize itself together in this emerging area to translate the benchtop science to the patient bedside.

Kinetics of collagen crosslinking in adult bovine articular cartilage

OBJECTIVE

Determine the kinetics of collagen crosslinking in adult bovine articular cartilage explants using radiolabel pulse-chase studies.

METHODS

Explant cultures of adult bovine articular cartilage were radiolabeled with [14C]lysine in medium including fetal bovine serum and ascorbate, and then maintained for chase periods up to 28 days. In some samples, beta-aminopropionitrile (BAPN) was included during chase to inhibit lysyl oxidase-mediated collagen crosslinking. Tissue was hydrolyzed and analyzed for [14C]metabolites in the forms of lysine, hydroxylysine, dehydrodihydroxylysinonorleucine (DeltaDHLNL), and hydroxylysyl pyridinoline (HP).

RESULTS

Explant cultures of adult bovine articular cartilage metabolized lysine into hydroxylysine and the collagen crosslinks, DeltaDHLNL and HP. During chase, [14C]hydroxylysine maintained steady-state levels, [14C]DHLNL rose to a plateau, and [14C]HP increased gradually. Addition of BAPN inhibited formation of [14C]DHLNL. Analysis of raw data and that normalized to [14C]hydroxylysine gave characteristic time constants for formation of DeltaDHLNL and HP crosslinks of 1-2 and 7-30 days, respectively. The distribution of [14C]lysine metabolites in collagen crosslinks was described by peak values in [14C]DHLNL/[14C]hydroxylysine of 0.047-0.064 and in [14C]HP/[14C]hydroxylysine of 0.03.

CONCLUSION

Collagen crosslinks form in cartilage explants in vitro according to the classical lysyl oxidase-mediated pathway.

Amoebic versus pyogenic liver abscess

OBJECTIVES

To study the differences between the clinical presentation and complications of amoebic and pyogenic liver abscess. To correlate the diagnostic significance of Entamoeba Indirect Haemagglutination test (E.IHA) in establishing the diagnosis of amoebic liver abscess.

DESIGN

Open cohort observational study.

SETTING

Department of Medicine (Medical Unit II) Jinnah Postgraduate Medical Centre, Karachi.

PARTICIPANTS

Fifty two patients aged 13-70 years admitted in Medical Unit II and diagnosed to have liver abscess.

INTERVENTIONS

Group A comprised of patients clinically diagnosed to have amoebic liver abscess and received Metronidazole 500mg iv x 8 hourly for atleast 10 days or more if patient developed complications. Group B comprised of patients diagnosed to have pyogenic abscess and received Cefotaxime 1g iv x 8 hourly for the same duration or more if complicated (antibiotic reviewed in accordance with culture and sensitivity report).

MAIN OUTCOME MEASURES

Differences in the clinical presentation, complications and diagnostic parameters between the two groups of patients.

RESULTS

It was not possible to differentiate between amoebic and pyogenic liver abscess on clinical grounds, routine investigations and imaging techniques. Aspiration of pus, especially if the abscess was multiple, was most helpful in differentiating the two types of abscesses. Serological test of E.IHA was highly specific and sensitive for amoebic liver abscess.

CONCLUSION

Majority of liver abscesses in Karachi are due to Entamoeba Histolytica. Pyogenic abscess though less frequent, must be excluded by pus aspiration and culture and sensitivity. E.IHA is a good rapid method of discriminating between the two types of abscesses.

Diabetes mellitus is equally frequent in chronic HCV and HBV infection

OBJECTIVE

To see the association of type 2 diabetes mellitus (Type 2 DM) in patients suffering from chronic HBV or HCV related liver disease.

SETTING

Patients were selected from the gastroenterology OPD of the medical research centre, diabetic controls from private diabetes clinic and healthy controls from the blood bank of the hospital.

METHODS

Patients with chronic liver disease had HBV, HCV tested using ELISA and blood sugar using a glucometer mostly as a 2 hour post prandial sample. Healthy controls had their sugar and ALT checked while donating blood and HBV, HCV were checked routinely. In diabetic controls, blood sample was taken as sera stored for HBV,HCV and ALT and later tested in batches. A random sugar of > or = 200 mg/dl was taken as diabetes.

RESULTS

Of 400 patient with chronic liver disease 302 had HCV and 98 HBV infection. Diabetes was found in 24.5% HCV and 19.4% HBV related cases (not significant). Out of 410 healthy controls 18 were HCV and 17 HBV positive. Diabetes was found in only 1 (5.6%) HCV positive control and none of the HBV positive controls. Of 196 diabetics 10 (5.1%) were HCV positive and none HBV positive. Diabetes was more frequent in patients having liver cirrhosis than in those having chronic hepatitis (P < 0.01).

CONCLUSION

Diabetes is equally frequent in both HBV and HCV related disease but is significantly more in those with chronic liver disease than in controls. The pancreatic damage secondary to extrahepatic viral replication appears to be the major cause but genetic factors also need to be explored.

Role of dexamethasone in acute bacterial meningitis in adults

OBJECTIVE

To evaluate the role of dexamethasone as adjunctive therapy in adult acute bacterial meningitis (ABM) in two groups of patients treated with antibiotics alone or a combination of antibiotics and dexamethasone.

DESIGN

Systematic sampling interventional open cohort study.

SETTING

Department of Medicine (Medical Unit II), Jinnah Postgraduate Medical Centre, Karachi.

PATIENTS

Sixty eight patients aged 12-85 years admitted in Medical Unit II and diagnosed to have ABM. Patients were divided into two groups. Group A received anti-microbial therapy for 14 days (a combination of benzyl penicillin 6 million units I/V 6 hourly and chloramphenicol 1 gm I/V 6 hourly) and group B received the same antimicrobial therapy with dexamethasone 0.6 mg/kg/day in 3 divided doses for 4 days.

MAIN OUTCOME MEASURES

Differences in mortality and morbidity in the two groups and differences in the CSF inflammatory parameters between the two groups of patients.

RESULTS

There was early resolution of fever, headache and altered consciousness in group B as compared to group A. Cranial nerves involvement was lower in group B. There was no difference in the occurrence of other focal neurological deficits between the two groups. CSF inflammatory parameters (glucose, protein and WBC count) were significantly better in group B by day 5. No complications attributable to dexamethasone were seen in group B.

CONCLUSION

There was early resolution of symptoms and CSF inflammatory parameters in the group that received dexamethasone as adjuvant therapy. Mortality was lower in the group treated with dexamethasone but the difference was not statistically significant. Dexamethasone should be administered to all adults patients with ABM.

Integrative cartilage repair: inhibition by beta-aminopropionitrile

The effects of beta-aminopropionitrile, a known inhibitor of lysyl oxidase, on the extractability of newly synthesized collagen and integrative cartilage repair were determined in explant cultures of adult bovine articular cartilage. Dose-escalation studies indicated that treatment of cartilage explants for 6 days with beta-aminopropionitrile caused a dose-dependent inhibition of proteoglycan synthesis ([35S]sulfate incorporation) with a 50% inhibition at 2.2 mM. However, 0.25 mM beta-aminopropionitrile had no detectable effect on proteoglycan synthesis and was thus used for subsequent experiments. Treatment of cartilage with beta-aminopropionitrile for 14 days increased the extractability of newly synthesized collagen with 4 M guanidine-HCl while having little effect on proteoglycan synthesis, proteoglycan deposition, collagen synthesis (formation of [3H]hydroxyproline after labeling with [3H]proline), collagen deposition, or cartilage cellularity (DNA content). In untreated cultures, the percentage of radiolabeled collagen ([3H]hydroxyproline) that was extractable after 1 day of radiolabeling, 6 days of radiolabeling, or 6 days of label and 6 days of chase decreased from 81 to 25 and 9%, respectively. In beta-aminopropionitrile-treated cultures, the extractability was relatively higher (96, 62, and 47%, respectively). Treatment with beta-aminopropionitrile after radiolabeling with [14C]lysine also significantly inhibited the formation of the reducible crosslink [14C]dihydroxylysinonorleucine without affecting the overall deposition in cartilage of [14C]lysine and [14C]hydroxylysine. In functional repair studies, treatment with beta-aminopropionitrile caused an almost complete inhibition of integration between pairs of cartilage explants maintained in apposition for 2 weeks. These results indicate that beta-aminopropionitrile blocks the formation of collagen crosslinks in cartilage explants and suggest that such crosslinks are critical to integrative cartilage repair.

Biomechanics of integrative cartilage repair

Cartilage repair is required in a number of orthopaedic conditions and rheumatic diseases. From a macroscopic viewpoint, the complete repair of an articular cartilage defect requires integration of opposing cartilage surfaces or the integration of repair tissue with the surrounding host cartilage. However, integrative cartilage repair does not occur readily or predictably in vivo. Consideration of the 'integrative cartilage repair process', at least in the relatively early stages, as the formation of a adhesive suggests several biomechanical approaches for characterizing the properties of the repair tissue. Both strength of materials and fracture mechanics approaches for characterizing adhesives have recently been applied to the study of integrative cartilage repair. Experimental configurations, such as the single-lap adhesive test, have been adapted to determine the strength of the biological repair that occurs between sections of bovine cartilage during explant culture, as well as the strength of adhesive materials that are applied to opposing cartilage surfaces. A variety of fracture mechanics test procedures, such as the (modified) single edge notch, 'T' peel, dynamic shear, and trouser tear tests, have been used to assess Mode I, II, and III fracture toughness values of normal articular cartilage and, in some cases, cartilaginous tissue undergoing integrative repair. The relationships between adhesive biomechanical properties and underlying cellular and molecular processes during integrative cartilage repair remain to be elucidated. The determination of such relationships may allow the design of tissue engineering procedures to stimulate integrative cartilage repair.

Falciparum malaria or fulminant hepatic failure?

Six cases of severe jaundice and encephalopathy due to falciparum hepatitis initially diagnosed as fulminant hepatic failure are reported. This rare presentation of falciparum malaria should be suspected in patients with persistent fever, jaundice, encephalopathy and hepatomegaly. The diagnosis should be further suspected when the liver function tests show a predominantly conjugated hyperbilirubinemia with only modest elevation of liver enzymes and alkaline phosphatase. Liver biopsy is valuable in establishing the diagnosis at all stages of the disease.

Enoxacin in the treatment of typhoid fever

Enoxacin 400 mg twice daily was given orally to 40 patients who had Salmonella typhi- or Salmonella paratyphi-positive blood or bone marrow cultures. One patient was switched to parenteral therapy within 48 hours of study enrollment, but the remaining 39 patients were given enoxacin for 10 to 14 days. All 39 patients were cured by enoxacin, even though 23 (58.9%) strains were resistant to cotrimoxazole and 16 (41%) strains were multiply resistant to ampicillin, chloramphenicol, and cotrimoxazole. No adverse events necessitated the interruption of therapy. In this study, enoxacin was well tolerated and efficacious in the treatment of typhoid fever.