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Biomedical subjects

A M Khan

Publications and source records attributed to A M Khan.

At least 19 recordsLinked to original sources

Wegener's granulomatosis: a rare, chronic and multisystem disease.

Wegener's granulomatosis (WG) is an autoimmune disease which has a clinical predilection for the upper airways, lungs and kidneys. It is a necrotising granulomatous vasculitis which is associated with a distinct autoantibody--the antineutrophil cytoplasmic antibody (ANCA). A heightened index of suspicion by clinicians is needed in the diagnosis of this complex and rare condition. A multidisciplinary approach should then be used to treat this chronic multisystem disease. Treatment involves the use of various regimens of corticosteroids and immunosuppressive medication. Mortality due to WG has been significantly decreased by this therapy. In this article, we focus on clinical manifestations and review the salient histologic, laboratory and serologic features and treatment.

Antibodies, Antineutrophil Cytoplasmic↗

Laryngopharyngeal reflux: A literature review.

Laryngopharyngeal reflux (LPR) is a common condition encountered in otolaryngological practice in the United Kingdom. It is one of the most important aetiological factors for many inflammatory disorders of the upper aerodigestive tract. The presentations are diverse and include chronic hoarseness, sensation of a foreign body in the throat, sore throat, dysphagia, postnasal drip, excessive throat mucous, chronic cough and throat clearing. LPR patients may not complain of heartburn. Although LPR is common, its diagnosis may not be easy, as its symptoms are non specific and the laryngeal findings are not always associated with symptom severity. This article discusses an overall view of LPR in terms of pathophysiology, clinical presentation, diagnosis and treatment

Diagnosis, Differential↗

Torsion and infarction of an accessory liver lobe.

Accessory lobes of the liver (ALL) may be congenital or acquired and are usually of no clinical significance. Torsions of the ALL are exceedingly rare and most are incidental findings at laparotomy, autopsy and in the course of investigation radiological investigations. A total of 17 infant and adult cases have been described previously in the medical literature. Most cases described since 1925 have been diagnosed at laparotomy, we report the 18th case of torsion of the accessory lobe of the liver in an elderly female which, despite all radiological interventions, required laparoscopy for diagnosis. We conclude that torsion of the accessory lobes of the liver is a rare finding; radiological imaging does not reveal the diagnosis and most are found at laparotomy. Laparoscopy may aid in the diagnosis of torsion of accessory liver lobes. If pain persists, we advocate the use surgical intervention with or without cholecystectomy.

Abdominal Pain↗

Extended-interval gentamicin administration in malnourished children.

Malnourished children have several physiologic abnormalities that can affect drug distribution and elimination. The aim of this study was to determine the efficacy, safety and pharmacokinetics of a once-daily dose of gentamicin compared with conventional thrice-daily dosing in malnourished children. To our knowledge, it has not been investigated in this population so far. A total of 310 malnourished children of either gender aged 6 months to 5 years with diarrhea and pneumonia were randomized to receive intramuscular gentamicin 5 mg/kg/day once-daily (OD) (n=148) or the same total daily amount given in three divided doses (TD) (n=162) in addition to ceftriaxone 75 mg/kg/day. After 48 h at steady state, gentamicin pharmacokinetics was assessed by fluorescence polarization immunoassay in a subgroup of 59 children and 43 children in the OD and TD groups, respectively. The groups were equivalent in baseline demographic, clinical and laboratory characteristics. Good and partial clinical responses occurred in 64 per cent vs. 54 per cent and 25 per cent vs. 27 per cent in the OD and the TD children, respectively (p=NS for both comparisons). Five patients in each treatment group died. Renal toxicity defined by change in serum creatinine was not observed in any patient from either group. In the OD group, mean+/-SD serum gentamicin concentrations at 1 (peak), 3, 5, 8, 23, and 24 (trough value) hours after the dose were 11.7+/-4.1, 4.4+/-1.2, 2.08+/-0.9, 1.01+/-0.6, 0.31+/-0.09 and 0.29+/-0.07 mg/l respectively. In the TD group, mean +/-SD serum gentamicin concentration at 1 hour (peak) was 4.7+/-1.8 mg/l and the trough concentration was 0.48+/-0.21 mg/l. In OD group, the gentamicin trough concentration was significantly lower (p<0.001) and the peak concentration was significantly higher (p<0.001) compared to TD group. The results of this study indicate that once-daily gentamicin is effective and safe in malnourished children. Widespread implementation of once-daily dosing in malnourished children is appropriate and will reduce number of intramuscular injections and hospital costs.

Anti-Bacterial Agents↗

Isolation of Vibrio cholerae from neonates admitted to an urban diarrhoeal diseases hospital in Bangladesh.

BACKGROUND: Very little is known about Vibrio cholerae infection in neonates with diarrhoea. AIM: The aim was to examine the frequency of enteropathogenic bacteria, especially Vibrio cholerae, in stool specimens from neonates with diarrhoea. METHODS: We reviewed the hospital records of 240 neonates admitted with diarrhoea to the Dhaka Hospital of ICDDR,B: Centre for Health and Population Research, Dhaka, Bangladesh during January-December 2001. On admission, rectal swabs or stool specimens were plated directly onto taurocholate-tellurite-gelatin agar, Salmonella-Shigella agar and MacConkey's agar for culture of Vibrio cholerae, Shigella and Salmonella spp. RESULTS: A single bacterial enteric pathogen was detected in 71 neonates, multiple pathogens in 12, and stool samples of 157 neonates revealed no pathogen. The identified enteropathogens were as follows: V. cholerae in 42 neonates, Shigella spp in 22, Salmonella spp in 8, Aeromonas spp in 9 and Hafnia alvei in 2. CONCLUSION: V. cholerae is not uncommon in neonates presenting with diarrhoea in cholera-endemic countries.

Aeromonas↗

Low osmolar oral rehydration salts solution in the treatment of acute watery diarrhoea in neonates and young infants: a randomized, controlled clinical trial.

To compare the efficacy and safety of low osmolar oral rehydration salts solution (ORS-75) (mmol/L: Na+ 75, osmolarity 245) with that of World Health Organization-recommended ORS (ORS-90) (mmol/L: Na+ 90, osmolarity 311 ) in the treatment of acute watery diarrhoea in neonates and very young infants, a randomized double-blind, controlled clinical trial was carried out at the Clinical Research and Service Centre of ICDDR,B: Centre for Health and Population Research, Dhaka, Bangladesh, during January 1998-December 1999. Infants, aged < or = 2 months, presenting with a history of watery diarrhoea of < or = 72 hours, with no or some dehydration and without any systemic illness, were randomly assigned to receive either ORS-75 or ORS-90 for the correction and subsequent prevention of dehydration. Infants were studied for a maximum of five days. Total stool output, stool frequency, and requirement for ORS were outcome measures. Serum electrolytes were measured at 24 hours after admission to monitor serum sodium imbalance. Seventy-three infants received ORS-75, and 71 received ORS-90. Both the groups were comparable in their baseline characteristics. Diarrhoea resolved within five days in 53% and 66% of infants receiving ORS-75 and ORS-90 respectively (p = 0.3). Total stool volume [median (inter-quartile range) 132 (65-280) vs 139 (70-259) g/kg, p = 0.9], during the study period, was not significantly different between the two groups. Total stool frequency [31 (16-51) vs 35 (16-53), p = 0.9] and total ORS intake [192 (96-374) vs 209 (134-317) mL/kg, p = 0.7] were similar between the groups. No infants developed late evidence of hypernatraemia, irrespective of treatment. The results of the study indicate that ORS-75 is as safe as standard ORS-90 in the treatment of acute watery diarrhoea in neonates and very young infants and is effective in correcting and preventing dehydration.

Bangladesh↗

Biodiversity of mosquitoes in Manipur State and their medical significance.

Entomological studies conducted during monsoon and post-monsoon season in Manipur State revealed the presence of fifty-five species of mosquitoes under ten genera. Out of the seventeen Anopheles species recorded, Anopheles aconitus, An. dirus and An. nivipes were recorded for the first time from the state. The present study has confirmed the existence of An. dirus, the major malaria vector in the Northeast from a selected area of the state. Among Culicines, four species viz., Aedes nigrostriatus, Malaya genurostris, Aediomyia catasticta and Toxorhynchites splendens which were not reported earlier from this state have been recorded in the present study. With the addition of these seven species of mosquitoes to the earlier record of mosquitoes so far reported from Manipur, the mosquito fauna swells up to one hundred and eleven including the major vectors of malaria of the Northeast and the potential vectors of Japanese encephalitis and dengue virus transmission in India.

Animals↗

Prediction of class I T-cell epitopes: evidence of presence of immunological hot spots inside antigens.

MOTIVATION: Processing and presentation of major histocompatibility complex class I antigens to cytotoxic T-lymphocytes is crucial for immune surveillance against intracellular bacteria, parasites, viruses and tumors. Identification of antigenic regions on pathogen proteins will play a pivotal role in designer vaccine immunotherapy. We have developed a system that not only identifies high binding T-cell antigenic epitopes, but also class I T-cell antigenic clusters termed immunological hot spots. METHODS: MULTIPRED, a computational system for promiscuous prediction of HLA class I binders, uses artificial neural networks (ANN) and hidden Markov models (HMM) as predictive engines. The models were rigorously trained, tested and validated using experimentally identified HLA class I T-cell epitopes from human melanoma related proteins and human papillomavirus proteins E6 and E7. We have developed a scoring scheme for identification of immunological hot spots for HLA class I molecules, which is the sum of the highest four predictions within a window of 30 amino acids. RESULTS: Our predictions against experimental data from four melanoma-related proteins showed that MULTIPRED ANN and HMM models could predict T-cell epitopes with high accuracy. The analysis of proteins E6 and E7 showed that ANN models appear to be more accurate for prediction of HLA-A3 hot spots and HMM models for HLA-A2 predictions. For illustration of its utility we applied MULTIPRED for prediction of promiscuous T-cell epitopes in all four SARS coronavirus structural proteins. MULTIPRED predicted HLA-A2 and HLA-A3 hot spots in each of these proteins.

Algorithms↗

ANTIMIC: a database of antimicrobial sequences.

Antimicrobial peptides (AMPs) are important components of the innate immune system of many species. These peptides are found in eukaryotes, including mammals, amphibians, insects and plants, as well as in prokaryotes. Other than having pathogen-lytic properties, these peptides have other activities like antitumor activity, mitogen activity, or they may act as signaling molecules. Their short length, fast and efficient action against microbes and low toxicity to mammals have made them potential candidates as peptide drugs. In many cases they are effective against pathogens that are resistant to conventional antibiotics. They can serve as natural templates for the design of novel antimicrobial drugs. Although there are vast amounts of data on natural AMPs, they are not available through one central resource. We have developed a comprehensive database (ANTIMIC, http://research.i2r. a-star.edu.sg/Templar/DB/ANTIMIC/) of known and putative AMPs, which contains approximately 1700 of these peptides. The database is integrated with tools to facilitate efficient extraction of data and their analysis at molecular level, as well as search for new AMPs. These tools include BLAST, PDB structure viewer and the Antimic profile module.

Animals↗

Plesiomonas shigelloides-associated diarrhoea in Bangladeshi children: a hospital-based surveillance study.

Little is known about clinical and epidemiological features of Plesiomonas shigelloides-associated diarrhoea in children. We reviewed hospital-based surveillance records of 38 children with diarrhoea having P. shigelloides as the only pathogen isolated from their faecal specimen. Of those 38 children, 29 (76 per cent) were below 2 years of age and 28 (74 per cent) were male. Thirty-two (84 per cent) children presented with watery diarrhoea and six (16 per cent) had dysenteric stools. Vomiting was a feature in 27 (71 per cent) children and clinically significant dehydration was observed in nine (23 per cent) children. Fever was present in three (8 per cent) children and five (13 per cent) had diarrhoea 14 days. Thirty-three (87 per cent) children were successfully treated with ORS alone and only five (13 per cent) required intravenous fluid in addition to ORS. Plesiomonas shigelloides was isolated throughout the year. The findings may be of public health importance for creating awareness among physicians about the clinical profile and management strategy of P. shigelloides-associated diarrhoea in children.

Age Distribution↗

Hip osteoarthritis: where is the pain?

BACKGROUND: Pain radiating below the knee is typically thought to originate from the lumbosacral spine rather than degenerative hip pathology. We investigated the lower limb distribution of pain using body image maps in 60 patients awaiting primary hip arthroplasty and in 60 patients awaiting spinal decompression for confirmed spinal stenosis. The perception of 33 orthopaedic registrars regarding distribution of hip pain was also assessed. RESULTS: Groin and buttock pain are significantly more common in hip osteoarthritis. The presence of groin pain is 84.3% of those sensitive for hip dysfunction with a specificity of 70.3%. Patients with hip osteoarthritis had pain below the knee in 47% of cases whereas 88.5% of orthopaedic trainees believed hip pain did not radiate below the knee. Radiographic features of osteoarthritis within the hip joint, visual analogue pain score or Oxford Hip Score have no significant association with a patient's distribution of hip pain. CONCLUSIONS: Hip pain referred below the knee is common with a degenerate hip joint and follows the distribution of the saphenous nerve, which branches from the femoral nerve. Radiographic deterioration of a hip joint does not correlate with pain distribution or patient dysfunction as measured by the Oxford Hip Score.

Adult↗

Cross-match protocols for femoral neck fractures--finding one that can work.

BACKGROUND: Cross-match practice for patients with femoral neck fractures continues to cause concern due to a failure of compliance to the existing protocols. To address this issue, a number of studies were conducted over a 3-year period. METHODS: First, the existing cross-match practice for patients admitted with femoral neck fractures was reviewed to demonstrate the deficiencies within the system. Second, the opinion of anaesthetic and orthopaedic trainees was assessed regarding blood requirements for different femoral neck fractures following surgery and the justification of their perceptions. RESULTS: A summation of the studies is reported which demonstrates the reasons for the poor compliance to previous protocols. CONCLUSIONS: A simple and effective protocol is provided that has helped reduce pre-operative cross-matching of femoral neck fractures from 71% to 16.7% when assessed 2 years after its introduction.

Blood Grouping and Crossmatching↗

Entomological observations on dengue vector mosquitoes following a suspected outbreak of dengue in certain parts of Nagaland with a note on their susceptibility to insecticides.

Three species of Aedes viz., Aedes albopictus, Aedes aegypti and Aedes annandalei were detected from different breeding sources in and around human habitats during entomological study conducted following an outbreak suspected to be of dengue (which occurred during, 1994) in parts of Medziphema PHC area of Nagaland in two different points of time ie., in the year, 1994 and, 2000. The potential dengue vector, Aedes albopictus showed high preponderance by breeding in all types of containers searched with high Breteau Index (BI) value of 85.0 and 72.72 recorded in, 1994 and, 2000 respectively whereas the BI value for other potential vector, Aedes aegypti was recorded low (4.9) in the year, 1994 with a substantial increase (31.81) in, 2000. The change in ecosystem along with the process of urbanization has facilitated the growth of these dengue vector mosquitoes in the area of investigation. Adults of both Aedes aegypti and Aedes albopictus were found to be susceptible to DDT, dieldrin and malathion in insecticide bioassay carried out using WHO test kit.

Aedes↗

A focus of lymphatic filariasis in a tea garden worker community of central Assam.

A survey for lymphatic filariasis was conducted among tea garden workers of central Assam. Of the 656 night blood samples examined, 31 were found positive for Wuchereria bancrofti parasite (microfilaria rate 4.7%). Microfilaria rate was higher in male (7.3%) than females (2.1%). Culex quinquefasciatus was incriminated as vector mosquito.

Agriculture↗

Sacroiliac joint fusion for chronic pain: a simple technique avoiding the use of metalwork.

A previously undescribed method for posterior fusion of the sacroiliac joint (SIJ) utilizing the Cloward instrumentation is presented, suitable for cases with chronic pain and intact ligamental structures of the SIJ. The advantages of the method in comparison with other described options include minimal disturbance of the periarticular structures, avoidance of introduction of metalwork and preservation of the iliac crest contour. This technique has been used in five cases with follow-up longer than 2 years (mean 29 months, range 25-41 months). In all cases there was resolution of their painful symtomatology.

Adult↗