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Biomedical subjects

N Akhtar

Publications and source records attributed to N Akhtar.

At least 19 recordsLinked to original sources

Surgical delay in the management of dog bite injuries in children, does it increase the risk of infection?

Dog bites are contaminated wounds and convention dictates that any surgical treatment should be performed at the earliest opportunity. This practice, however, may be in direct conflict with NCEPOD guidelines to reduce night time operating. We audited our treatment of dog bite injuries in children over a 5-year period (1998-2002) to determine whether delaying surgery to conform to operating guidelines increased the incidence of infection. A retrospective case note study identified 118 patients admitted to Sheffield Children's Hospital with dog bite injuries. Details of their injury, treatment and outcome were recorded. There were 70 males and 48 females and an average age of 6.6 years (range 1-15 years). The most common type of injury was a single laceration (32%) and the most frequent site of injury was the face (59%). The majority of wounds (68%) were cleaned and dressed before theatre and 89% were closed directly after minimal debridement. All patients received prophylactic antibiotics. Of the 114 patients that required surgery, 57 (50%) were operated on within 12 h of their injury and 57 (50%) after 12 h. There were three cases of infection in the early group (<12 h) and none in the delayed group (>12 h). We suggest that delaying the surgical treatment of dog bites in children to avoid operating at night does not increase the infection rate.

Animals↗

Physical examination of the carpal bones by orthopaedic and accident and emergency surgeons.

Our aim was to test knowledge of carpal bone surface anatomy among orthopaedic and accident and emergency surgeons. A survey of 58 surgeons was conducted. Each was asked to palpate seven points on five commonly injured carpal bones. Eight surgeons declined to participate. Five of the remaining 50 correctly palpated all surface markings. Six failed to accurately palpate even a single point. The scaphoid waist and trapezial ridge were accurately palpated by 47 surgeons. The median score for all participants was 3 correctly identified points. The majority of orthopaedic and accident and emergency surgeons do not perform an accurate physical examination of the carpal bones. The ancient art of history taking, precise physical examination and elucidation of a confident diagnosis is at risk of being replaced with tentative diagnoses and imaging techniques that are expensive and time consuming. We believe that basic anatomical teaching is inadequate.

Carpal Bones↗

Removal and recovery of nickel(II) from aqueous solution by loofa sponge-immobilized biomass of Chlorella sorokiniana: characterization studies.

The biosorption process for the removal of nickel(II) by loofa sponge-immobilized biomass of Chlorella sorokiniana (LIBCS), a newly developed immobilized biosorbent, was characterized. Effects of environmental factors on metal uptake capacity of LIBCS were studied and compared with free biomass of C. sorokiniana (FBCS). Nickel(II) removal by LIBCS was found to be influenced by pH of the solution, initial metal concentration, and biomass concentration. The biosorption of nickel(II) ions by both LIBCS and FBCS increased as the initial concentration of nickel(II) ions increased in the medium. No loss to biosorption capacity of LIBCS for nickel(II) was found due to the presence of loofa sponge, indeed as compared to FBCS an increase of 25.3% was noted in the biosorption capacity of LIBCS. Maximum biosorption capacities for FBCS and LIBCS were found as 48.08 and 60.38 mg nickel(II)/g, respectively, whereas the amount of nickel(II) ions adsorbed on the plain loofa sponge was 6.1mg/g. During these biosorption studies, LIBCS exhibited excellent physical and chemical stability without any significant release/loss of microalgal biomass from loofa sponge matrix. The kinetics of nickel(II) removal was extremely fast reaching at equilibrium in about 15 min for LIBCS and 20 min for FBCS. The biosorption equilibrium was well described by the Langmuir and Freundlich adsorption isotherms. The biosorption capacities were found to be solution pH dependent and the maximum adsorption was found at a solution pH 4-5. The LIBCS could be regenerated using 75 mM HCl, with up to 98% recovery. The LIBCS were shown to be robust and stable with little decrease in the nickel(II) uptake capacity when used in consecutive seven biosorption-desorption cycles. Continuous removal of nickel(II) from electroplating effluent by LIBCS packed in fixed bed column bioreactor confirm the possibility of developing a biological treatment process for the removal of toxic metals from authentic wastewater.

Adsorption↗

Severe haemorrhage in neurofibromatoma: a lesson.

Neurofibromatosis is a relatively common inherited disease of the nervous system, with a frequency of almost 1 in 3000. It is associated with a wide range of vascular abnormalities. A 62-year-old man with neurofibromatosis presented to us with a sacral haematoma. This was due to spontaneous rupture of a pre-existing neurofibromata. Upon admission the patient was in hypovolaemic shock and required aggressive resuscitation prior to surgery. Haemorrhage following trauma or spontaneous rupture is an uncommon complication of neurofibromatosis. The management is discussed with emphasis on the cause and control of bleeding from these lesions.

Hematoma↗

Seroprevalence of dengu infections amongst the children.

Serosurvillance of 650 children of clinically suspected dengue infection based on simple laboratory tests were evaluated to find out the early indicator for diagnosis of dengue infection. The study was conducted among the patients attending the Sir Salimullah Medical College (SSMC) and Mitford Hospital and Popular Diagnostic Center, Dhaka, during July 2002 to September 2002. Of these 650 suspected dengue cases, 294 were in the age group 1-5 years, 206 were in age group 6-10 years and 150 cases in age group 11-15 years, of which Seropositivity was found in 78 (26.53%), 60 (24.12%) and 65 (43.33%) cases respectively. Primary dengue IgM was positive in 123 (60.59%) cases and secondary dengue (IgG & IgM combined or IgG alone) was positive in 80 (39.41%) cases. Leucopenia was found in 90 (75%) cases and Thrombocytopenia was found in 95 (79.16%) cases in primary dengue cases. Similarly in secondary dengue cases TWBC and PLT was decreased in 60 (72.29%) and 65 (78.15%) cases respectively. Haemoconcentration was found in 40 (36.67%) cases of primary dengue and 13 (18%) cases in secondary dengue. Month wise distribution of dengue seropositivity shows that 10 (8.53%) cases was found in July, 175 (50.10%) cases in August and 78 (10.00%) cases in September. This study reveals that seropositivity is highest (43.33%), in the age group 11-15 years and incidence of dengue increased in the month of August. Leucopenia (WBC <or= 5000) and Thrombocytopenia (Patelet count <or= 100000) were two findings that help in the early diagnosis of dengue infection.

Adolescent↗

Patch test for the detection of contact allergens.

Patch Test was done in 340 suspected allergic contact dermatitis patients having different ages of both sexes during the period of January 2000 to December 2003 in the department of Dermatology and Venerology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka. Of these 340 cases 145 (42.65%) were male and 195 (57.35%) were female. Among these 340 cases, 250 (73.53%) cases were tested with international standard series allergen (ISS) and 90 (26.47%) cases with cosmetic series allergen (CSS), of which patch test was positive in 125 (50%) cases and 65 (72.22%) cases respectively. The 125 positive cases with ISS consisted of 56% male and 44% female. In 65 CSS positive cases 90.77% were female and 9.23% were male. Highest incidence of positive patch test was found in 61.54% cases in the age group of 30-39 years in ISS and 71.43% cases in the age group of 20-29 yrs in CSS. In ISS--Potassium Dichromate (19.2%), Fragrance mix (17.6%), Nickel Sulphate (15.2%) and PPD (11.2%) were found to be the common allergen and in CSS--Octyl Gallate (27.69%), Getrimide (18.92%), Balsum of Peru (15.38%), Thiomersal (12.31%) were found to be the common allergens.

Adolescent↗

Microalgal-luffa sponge immobilized disc: a new efficient biosorbent for the removal of Ni(II) from aqueous solution.

AIMS: The aim was to develop a new, efficient and cost-effective biosorbent for the removal of heavy metals from aqueous solution. METHODS AND RESULTS: A new biosorbent was developed by immobilizing a unicellular green microalga Chlorella sorokiniana within luffa sponge discs and used for the removal of metal ions from aqueous solution. Microalgal-luffa sponge immobilized discs (MLIDs) removed Ni(II) very rapidly, with 97% of equilibrium loading being reached in 5 min. MLIDs were tested for their potential to remove Ni(II) from aqueous solution in fixed-bed column bioreactor. The regenerated MLIDs retained 92.9% of the initial binding capacity for Ni(II) up to five cycles of reuse. CONCLUSIONS: In this study for the first time, C. sorokiniana biomass immobilized within luffa sponge disc was successfully used as a metal biosorbent for the removal of Ni(II). It appears that MLIDs can be used as an effective biosorbent for efficient removal of Ni(II) or other metals from aqueous solution. SIGNIFICANCE AND IMPACT OF THE STUDY: MLIDs biosorption system was shown to have good biosorption properties with respect to Ni(II). Efficient metal removal ability of MLIDs, low cost and simplicity of the technique used for the preparation of MILDs could provide an attractive strategy for developing high-affinity biosorption system for heavy metal removal.

Biomass↗

Moyamoya disease: an elusive diagnosis.

OBJECTIVE AND BACKGROUND: Moyamoya disease is an idiopathic vasculopathy of circle of Willis. Stroke is a common presentation. We describe clinical and radiological features of moyamoya disease in four patients. SETTING: Tertiary care center in a metropolitan city. MATERIALS AND METHODS: Patients with moyamoya disease were identified by ICD-9 coding system of the hospital medical records. Demographic characteristics, clinical features/presentation, laboratory investigations and radiological investigations were recorded and analyzed. RESULTS: Four patients (three children and one adult) presented with hemiparesis. One patient expired during hospital stay. Two patients underwent surgery (synangiosis). EEGs of three patients showed focal abnormalities. Neuroimaging showed ischemic infarctions in all patients. Findings on four vessel digital substraction angiography and/or magnetic resonance angiography were compatible with moyamoya disease. CONCLUSION: Moyamoya disease should be considered in all young patients, especially children, presenting with stroke.

Adolescent↗

Ischemic stroke subtypes in Pakistan: the Aga Khan University Stroke Data Bank.

OBJECTIVE: Frequency of ischemic stroke subtypes is influenced by ethnic and geographic variables. Our objective was to identify various stroke subtypes and its determinants at a tertiary care hospital. METHODS: We prospectively collected data on ischemic stroke subtypes admitted to The Aga Khan University Hospital in Karachi. RESULTS: A total of 596 patients were enrolled in 22 months in the Aga Khan Universtiy Stroke Registry. These included 393 patients with Ischemic stroke, 126 patients with intracerebral hemorrhage, 50 patients with subarachnoid hemorrhage and others. The ischemic stroke group was classified according to the TOAST criteria and comprised of lacunar 168/393 (42.7%); large artery atherosclerosis 106/393 (26.9%); cardioembolic 24/393 (6.1%); undetermined 80/393 (20.3%); and other determined types 15/393 (3.8%). The high proportion of lacunar strokes in our population may be due to high burden of inadequately treated hypertension and diabetes. Clear cut cardioembolic stroke was relatively infrequent in our population. CONCLUSION: Lacunar stroke is the most common subtype of stroke in our patient population. This is most likely secondary to uncontrolled hypertension.

Adult↗

Petiolar felt-sheath of palm: a new biosorbent for the removal of heavy metals from contaminated water.

Biosorption of heavy metals such as Pb2+, Ni2+, Cd2+, Cu2+, Cr3+ and Zn2+ by petiolar felt-sheath of palm (PFP) from contaminated water was examined. PFP was found to efficiently remove all the toxic metal ions with selectivity order of Pb2+ > Cd2+ > Cu2+ > Zn2+ > Ni2+ > Cr3+. The uptake was rapid, with more than 70% completed within 15 min. The bound metal ions were successfully desorbed and the PFP fibrous-biomass remained effective after several adsorption-desorption cycles.

Adsorption↗

The p85 subunit of phosphoinositide 3-kinase is associated with beta-catenin in the cadherin-based adhesion complex.

Cell adhesion is fundamental to establishing and maintaining the discrete tissues in multicellular organisms. Adhesion must be sufficiently strong to preserve tissue architecture, whilst having the capacity to readily dissociate to permit fundamental processes, such as wound repair, to occur. However, very little is known about the signalling mechanisms involved in temporary down-regulation of cell adhesion to facilitate such processes. Cadherins are the principal mediators of cell-cell adhesion in a wide variety of tissues and species and form multi-protein complexes with cytosolic and cytoskeletal proteins to express their full adhesive capacity. In the present study we report that the p85 subunit of phosphoinositide 3-kinase (PI 3-kinase) is associated with the cadherin-based adhesion complex in human epithelial cells. The interaction of p85 with the complex is via beta-catenin. We also show that the interaction of p85 and beta-catenin is direct, involves the N-terminal Src homology domain 2 of p85 and is regulated by tyrosine phosphorylation. These data suggest that PI 3-kinase may play a role in the functional regulation of the cadherin-based adhesion complex.

Animals↗

Transient expression of the NG2 proteoglycan by a subpopulation of activated macrophages in an excitotoxic hippocampal lesion.

Cells that express the NG2 proteoglycan (NG2+ cells) constitute a large glial population in the normal mature rodent brain. They can differentiate into oligodendrocytes but are distinct from mature oligodendrocytes, astrocytes, microglia, and neurons. Changes in NG2+ cells were examined in kainic acid-induced excitotoxic lesions of the hippocampus, and the relationship between NG2+ cells and reactive astrocytes and microglia was investigated between 1 and 90 days after lesioning. Two types of reactive NG2+ cells with altered morphology and increased NG2 immunoreactivity were observed in the lesion. Early changes, consisting of an increase in NG2 immunoreactivity and the number of processes, were apparent 24 h after lesioning and persisted through 3 months. These cells were distinct from reactive astrocytes or activated microglia/macrophages. A second type of reactive NG2+ cells appeared 2 weeks after injection, following an influx of macrophages. They had large, round cell bodies with short processes and expressed the microglia/macrophage antigens OX42 and ED1. Single cells coexpressing NG2 and macrophage/microglial antigens could be isolated from the lesion. The number of NG2+/OX42+ cells gradually declined and disappeared by 3 months after injection. They did not express glial fibrillary acidic protein or the alpha receptor for platelet-derived growth factor, indicating that they are distinct from astrocytes or oligodendrocyte progenitor cells. Cells that coexpressed NG2 and OX42 were never observed in hippocampal slice cultures treated with kainic acid, suggesting that NG2+/OX42+ cells are not derived from endogenous resident brain cells. These findings demonstrate that NG2 expression is transiently upregulated on activated macrophages/microglia that appear during the chronic stage in an excitotoxic lesion in the adult CNS.

Animals↗

Functional analysis of the yeast Ran exchange factor Prp20p: in vivo evidence for the RanGTP gradient model.

Numerous cellular processes rely on the movement of macromolecules into and out of the nucleus. The primary regulator of this movement is the small GTPase Ran. Like other small GTPases, the nucleotide-bound state of Ran is regulated by effectors that enhance the rate of nucleotide exchange or hydrolysis. Current models for vectorial nuclear transport suggest that it is the strict compartmentalization of these Ran effector molecules that generates a gradient of RanGTP between the nucleus and the cytoplasm to impart directionality to the transport process. Here we investigate the mechanism by which the Ran exchange factor is targeted to the nucleus, and test the impact of disrupting this nuclear compartmentalization on nucleocytoplasmic transport in vivo. Our results indicate that in Saccharomycces cerevisiae the nucleotide exchange factor Prp20p can be targeted to the nucleus via a classical nuclear localization sequence. This transport mechanism is dependent both on Ran and the receptor that recognizes the nuclear localization sequence, importin alpha. Mutations in the evolutionarily conserved nuclear localization sequence only partially inhibit nuclear import of Prp20p, suggesting the existence of a secondary mechanism for this critical nuclear targeting. In an in vivo test of the RanGTP gradient model, we demonstrate that overexpression of a functional cytoplasmic exchange factor inhibits cell growth and blocks both protein import and RNA export in wild-type cells that contain the endogenous nuclear Prp20 protein. Taken together, our results provide in vivo evidence for the idea that the compartmentalization of the exchange factor serves as a mechanism for establishing directional nuclear transport.

DNA-Binding Proteins↗