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Biomedical subjects

S Rahman

Publications and source records attributed to S Rahman.

At least 19 recordsLinked to original sources

Effects of acute and chronic nicotine on somatodendritic dopamine release of the rat ventral tegmental area: in vivo microdialysis study.

The objectives of the present study were to examine the effects of acute and chronic nicotine on dopamine (DA) release in the ventral tegmental area (VTA) of Long-Evans rats using in vivo microdialysis. Systemic application of acute nicotine (0.1-0.3 mg/kg, s.c.) significantly increased (145% of baseline) DA release in the VTA. Chronic exposure to nicotine (0.3 mg/kg, s.c.) for 5 days followed by a challenge dose of nicotine (0.3 mg/kg, s.c.) also produced significant enhancement (136% of baseline) of DA release in the VTA. The results suggest that both acute and chronic nicotine treatment exert stimulatory effects on somatodendritic DA release in the VTA. The enhancement of DA release to subsequent challenge nicotine may be susceptible to mild desensitization.

Animals↗

Genetic and functional analyses of FH mutations in multiple cutaneous and uterine leiomyomatosis, hereditary leiomyomatosis and renal cancer, and fumarate hydratase deficiency.

Germline mutations of the fumarate hydratase (FH, fumarase) gene are found in the recessive FH deficiency syndrome and in dominantly inherited susceptibility to multiple cutaneous and uterine leiomyomatosis (MCUL). We have previously reported a number of germline FH mutations from MCUL patients. In this study, we report additional FH mutations in MCUL and FH deficiency patients. Mutations can readily be found in about 75% of MCUL cases and most cases of FH deficiency. Some of the more common FH mutations are probably derived from founding individuals. Protein-truncating FH mutations are functionally null alleles. Disease-associated missense FH changes map to highly conserved residues, mostly in or around the enzyme's active site or activation site; we predict that these mutations severely compromise enzyme function. The mutation spectra in FH deficiency and MCUL are similar, although in the latter mutations tend to occur earlier in the gene and, perhaps, are more likely to result in a truncated or absent protein. We have found that not all mutation-carrier parents of FH deficiency children have a strong predisposition to leiomyomata. We have confirmed that renal carcinoma is sometimes part of MCUL, as part of the variant hereditary leiomyomatosis and renal cancer (HLRCC) syndrome, and have shown that these cancers may have either type II papillary or collecting duct morphology. We have found no association between the type or site of FH mutation and any aspect of the MCUL phenotype. Biochemical assay for reduced FH functional activity in the germline of MCUL patients can indicate carriers of FH mutations with high sensitivity and specificity, and can detect reduced FH activity in some patients without detectable FH mutations. We conclude that MCUL is probably a genetically homogeneous tumour predisposition syndrome, primarily resulting from absent or severely reduced fumarase activity, with currently unknown functional consequences for the smooth muscle or kidney cell.

Amino Acid Metabolism, Inborn Errors↗

A seven year experience of medical emergencies in the assessment unit.

AIMS: To analyse retrospectively all referrals to the assessment unit during a seven year period, to determine their sources and destination. METHODS: All referrals over the seven year period were analysed. Parental satisfaction was determined using a questionnaire in some of the patients. The disease pattern and the investigations performed were determined. The community nurses' working hours and type of work done were analysed. RESULTS AND CONCLUSIONS: A total of 43 496 children were seen in the unit. Over 65% of the patients were referred by the general practitioners; 13 517 (34.2%) of those referred to the unit were discharged directly from the unit. Respiratory disorders and gastrointestinal problems were commonly seen. The children discharged from the unit did not have significantly more tests done on them. Most of the parents whose children were discharged from the unit were happy to be managed at home. The community nurses attended many children who needed intravenous therapy and advice on fluid rehydration. Community nurses reduce admission to the wards by working with other members in the assessment unit. This in turn provides a single point of entry and bridges the gap between primary and secondary care. We suggest recommendations on setting up such a unit.

Child↗

The organization of genes tightly linked to the Ha locus in Aegilops tauschii, the D-genome donor to wheat.

The grain hardness locus, Ha, is located at the distal end of the short arm of chromosome 5D in wheat. Three polypeptides, puroindoline-a, puroindoline-b, and grain softness protein (GSP-1), have been identified as components of friabilin, a biochemical marker for grain softness, and the genes for these polypeptides are known to be tightly linked to the Ha locus. However, this region of the chromosome 5D has not been well characterized and the physical distance between the markers is not known. Separate lambda clones containing the puroindoline-a gene and the puroindoline-b gene have been isolated from an Aegilops tauschii (the donor of the D genome to wheat) genomic lambda library and investigated. Considerable variation appears to exist in the organization of the region upstream of the gene for puroindoline-b among species closely related to wheat. Using in situ hybridization the genes for puroindoline-a, -b, and GSP-1 were demonstrated to be physically located at the tip of the short arm of chromosome 5 of A. tauschii. Four overlapping clones were isolated from a large-insert BAC library constructed from A. tauschii and of these one contained genes for all of puroindoline-a, puroindoline-b, and GSP-1. The gene for puroindoline-a is located between the other two genes at a distance no greater than approximately 30 kb from either gene. The BAC clone containing all three known genes was used to screen a cDNA library constructed from hexaploid wheat and cDNAs that could encode novel polypeptides were isolated.

Chromosomes, Plant↗

The sugary-type isoamylase gene from rice and Aegilops tauschii: characterization and comparison with maize and arabidopsis.

Genes for an isoamylase-like debranching enzyme have been isolated from rice and Aegilops tauschii, the donor of the D genome to wheat. The structures of the genes are very similar to each other and to the maize SU1 isoamylase gene and consist of 18 exons spread over approximately 7.5 kb. Southern analysis and fluorescent in situ hybridization showed the Ae. tauschii gene to be located in the proximal region of the short arm of chromosome 7D, thus showing synteny with the localization of the rice isoamylase gene on rice chromosome 8. Analysis of the expression pattern of wheat sugary isoamylase genes indicates that they are strongly expressed in the developing endosperm 6 days after flowering. Three distinct Sugary-type cDNA sequences were isolated from the wheat endosperm that are likely to correspond to the products of the three genomes. The deduced amino acid sequence of rice and wheat Sugary-type isoamylase is compared with other sequences available in the database and the results demonstrate that there are three types of isoamylase sequences in plants: those containing 18 exons (the Sugary-type isoamylase gene), those containing 21 exons, and those containing only 1 exon. It is possible that different combinations of isoamylase genes are expressed in different tissues.

Amino Acid Sequence↗

Coronary artery disease in young patients: clinical review and risk factor analysis.

Fifty consecutive younger patients (< or = 40 years) with coronary artery disease, who underwent coronary angiography in National Institute of Cardiovascular Diseases were evaluated clinically and coronary risk factors were analyzed and compared with those of fifty older patients with coronary artery disease. Mean age of younger and older patients were 37.31 and 54.58 years respectively and myocardial infarction was the most common presenting complain in both the groups. Smoking and family history of premature coronary artery disease were more common in younger patients but the older patients were more diabetic and hypertensive. Central obesity and dyslipidemia did not vary between the two groups. Fifty percent of younger patients had one or two modifiable risk factors where sixty four percent of older patients had three or more modifiable risk factors. Forty four percent younger patients had hypercholesterolemia but a majority of patients had either isolated hypertriglyciredemia or decrease high density lipoprotein cholesterol or both with normal total cholesterol level but the total cholesterol and high density lipoprotein cholesterol index were more than 4.5. Younger patients had more number of normal coronary or single vessel diseases but older group had more number of triple vessel diseases. So the higher incidence of non-insulin dependent diabetes mellitus with central obesity suggesting insulin resistance along with unique profile of dyslipidemia, higher incidence of smoking and familial predisposition of premature coronary artery disease may be responsible for higher incidence of coronary artery disease at a premature younger age in this population.

Adult↗

Clinical profile of Kala-azar in adults: as seen in Mymensingh Medical College Hospital, Mymensingh, Bangladesh.

A total of eighty-one consecutive cases of Kala-azar admitted in all four medicine units of Mymensingh Medical College Hospital during the period from January 2002 to mid August 2002 were included in this study. The number of the patients clearly indicates that the burden of Kala-azar in this region is significant and expanding, which constituted 1.90% of total admission in all 4 medicine units during this period. Majority of the patients were of 20-29 years of age. Male to female ratio was 1.38:1. Maximum number of the patients were of poor socio-economic group with history of housing made up of mud and having close proximity with cattle house. Fever and splenomegaly (100%) were the predominant features. Hepatomegaly was found in 91.36% of the cases. Other clinical manifestations were weight loss (79.01%), normal or increased appetite (65.43%), generalized weakness (72.84%), pallor (69.13%), cough (25.92%), jaundice (17.28%), abdominal Pain (12.34%), hyperpigmentation (9.88%), ascites (4.94%) and bleeding manifestations (4.94%). Notable concomitant illnesses were urinary tract infection (7.40%), pulmonary tuberculosis (3.70%), malaria (1.23%), scabies (4.94%), heart failure (3.70%) and chronic liver disease (2.47%). Due to wide diversity of clinical presentations, clinical features of kala-azar should be evaluated in details which will pave the hidden cases into light.

Adult↗

A case of acromegaly.

A fifty years old woman hailing from Purbadhala of Netrokona district complaining of gradual enlargement of hands, feet, nose and other acral parts of the body for about last eight years. She noticed coarsening of the skin and gradual protrusion of her lower jaw. She complained of headache, vertigo, frequent passage of urine, increased thirst, weight loss and fatiguability. She was found hypertensive having blood pressure 200/110 mm of Hg. Her appearance was coarse with rough skin. There were enlargement of hands, feet, nose, lower jaw with prognathism and enlargement of other acral parts. Investigations revealed high plasma glucose level, both fasting and 2 hrs. after glucose, high level of growth hormone, failure of suppression of growth hormone during OGTT. Thyroid function tests of the patient were found normal with increased heel pad size and enlarged sella turcica in all diameters. She was diagnosed as a case of acromegaly due to growth hormone hypersecretion.

Acromegaly↗

Correlation between severity of coronary artery athesclerosis and duration and severity of diabetes mellitus in type 2 diabetic patients.

Hundred patients of Type 2 diabetes mellitus with coronary artery disease undergoing diagnostic coronary angiography were studied to determine the relation between the severity and duration of diabetes mellitus and the severity of coronary artery disease. A coronary scoring system using segmental distribution method was used to determine the severity of coronary artery disease and severity of diabetes was assessed by the level of fasting blood glucose within 48 hours of the procedure and also considering the types of treatment received for diabetes mellitus. No significant correlation was demonstrated between the severity of coronary artery disease and the severity (r =.089602; P>0.1) nor the duration (r =0.07865; P> 0.1) of diabetes mellitus on univariate analysis. So the Type 2 diabetic patients had an increased incidence of atherosclerosis in their coronary angiograms did not reflect an angiographically evident progressive coronary artery disease and results of this study suggest that the progress of large vessel coronary athesclerotic disease in diabetes mellitus of adult onset takes place independently of the progress of diabetes mellitus itself.

Adult↗

Epidemiological characteristics of sixty five cases of Kala-azar attending to a laboratory in Mymensingh.

To find out the epidemiological characteristics of the patients with Kala-azar attending to a pathology laboratory at Mymensingh we studied retrospectively in a total of 65 patients. These patients were suspected to be Kala-azar as they were suffering from usually chronic fever, anaemia and splenomegaly. They were referred for serological detection of anti-k39 Leishmanial antibody by Immunochromatographic test (ICT) method. ICT positive cases were included for study. Majority cases were suffering from fever of more than 3 months (40%). Out of 65 patients 43 (66.15%) were males and 22 (33.85%) were females with a M:F ratio 2:1. Patients of 10 or less then 10 years of age were 17 (26.15%), in 11-20 years 23 (35.38%), in 21-30 years 13 (20.00%), in 31-40 years 5 (7.69%), in 41-50 years (6.15%) and in more than 50 years 3 (4.62%). Distribution of patients in different districts were: Mymensingh 54 (83.08%), Tangail 5 (7.69%), Jamalpur (4.62%), Netrokona 1 (1.54%) and Kishorgonj 1 (1.54%). In Mymensingh district patients were distributed as following Upazilla:Trishal 22 (40.74%), Fulbaria 11 (20.37%), Mymensingh Sadar 7 (12.96%), Gaforgaon 7 (12.96%),Bhaluka 5 (9.96%), Fulpur 1 (1.85%) and Nandail 1 (1.85%). Patients were found to scattered among different Unions of the affected Upazillas. The details addresses of the Kala-azar patients are recorded in authors computer databases. This may help in the further study regarding pathogenesis, reservoir and vectors of Leishmania in endemic areas. It may also helps in the community based study of Kala-azar. Present study supports that Kala-azar is still prevailing in the south-western region of greater Mymensingh in Bangladesh of which males and the adolescents are more affected.

Adolescent↗

Immunochromatographic (rK39) strip test in the diagnosis of visceral leishmaniasis in Bangladesh.

Immunochromatographic strip test (ICT strip test) for the diagnosis of visceral leishmaniasis was evaluated in this study in the context of a case-control study. A total sixty consecutive cases of kala-azar admitted in all four Medicine Units of Mymensingh Medical College Hospital during the period of May 2002 to February 2003 was included here. Parasitological confirmation was done by demonstration of leishmania donovani bodies in bone marrow or splenic aspiration in all cases. A total 120 controls was taken of which sixty were asymptomatic endemic controls with no previous history of kala-azar and sixty were admitted patients suffering from diseases other than kala-azar (malaria, tuberculosis, enteric fever and chronic liver disease). ICT strip test for kala-azar was done in all cases and controls. Only 2 of the confirmed kala-azar cases were negative and the remaining 58 cases were positive for ICT strip test which gives the sensitivity of this test 96.6%. Among the controls, 118 were negative for ICT strip test and two of the asymptomatic controls were positive for this test with no clinical evidence of kala-azar. So, the estimated specificity of ICT strip test is 98.3%. The predictive value for a negative result was 98.3% and for a positive result was 96.6%. The ICT strip test is easy, quick, requires no technical facilities with higher sensitivity and specificity entails it to be the ideal test for the diagnosis of kala-azar in field level.

Adult↗

A case report on Wilson's disease.

A case of Wilson's disease, a rare autosomal recessive disorder of copper metabolism is reported here. The patient was presented with the difficulty in speech and writing for 4 years and also on walking for 1 year. He also noticed difficulty to perform any work by hands for 6 months. He had splenomegaly and bilateral gynaecomastia. His speech was low volume slurred and monotonous, muscle tone was mildly increased, and gait was limping. Slit lamp examination of eye revealed bilateral Kayser-Fleischer ring with normal visual acuity. Investigations revealed low serum albumin(26 gram/L), increased alanine trans-aminase ( A.L.T=57 U/L). Ultrasonogram of hepatobiliary system revealed coarse hepatic tissue echotexture with splenomegaly. Liver scan showed slightly nonuniform radiotracer distribution in the liver, there was slight increased bony uptake. Serum caeruloplasmin level was 11.51 mg/dl. 24 hours urinary copper excretion was 150 microgram per day. Liver biopsy revealed cirrhotic change. Now he was advised for taking copper chelating agent (penicillamine) in a dose of 1 gram/day.

Adolescent↗

Early expression of grain hardness in the developing wheat endosperm.

Seeds from near-isogenic hard and soft wheat lines were harvested at regular intervals from 5 days post-anthesis to maturity and examined for hardness using the single kernel characterisation system (SKCS). SKCS analysis revealed that hard and soft lines could be distinguished from 15 days post-anthesis (dpa). This trend continued until maturity where the difference between the hard and soft lines was most marked. SKCS could not be applied to the small 5- and 10-dpa wheat kernels. Fresh developing endosperm material was examined using light microscopy and no visible differences between the cultivars were detected. When air-dried material was examined using scanning electron microscopy (SEM) differences between soft and hard lines were visible from as early as 5 dpa. Accumulation of puroindoline a and puroindoline b was investigated in developing seeds using both Western blotting and ELISA. Low levels of puroindoline a could be detected in the soft cultivar from 10 dpa, reaching a maximum at 32 dpa. In the hard cultivar, puroindoline a levels were negligible throughout grain development. Puroindoline b accumulates in both the soft and hard cultivars from 15 dpa, but overall contents were higher in the soft cultivar. These findings indicate that endosperm hardness is expressed very early in developing grain when few starch granules and storage proteins were deposited in the endosperm cells. Further, the near-isogenic soft and hard Heron lines could be differentiated by SEM at a stage in development when the accumulation of puroindolines could not be detected by the methods used in this study.

Desiccation↗

Diagnostic value of succinate ubiquinone reductase activity in the identification of patients with mitochondrial DNA depletion.

Mitochondrial DNA (mtDNA) depletion syndrome (McKusick 251880) is characterized by a progressive quantitative loss of mtDNA resulting in severe mitochondrial dysfunction. A diagnosis of mtDNA depletion can only be confirmed after Southern blot analysis of affected tissue. Only a limited number of centres have the facilities to offer this service, and this is frequently on an irregular basis. There is therefore a need for a test that can refine sample selection as well as complementing the molecular analysis. In this study we compared the activities of the nuclear-encoded succinate ubiquinone reductase (complex II) to the activities of the combined mitochondrial and nuclear-encoded mitochondrial electron transport chain (ETC) complexes; NADH:ubiquinone reductase (complex I), ubiquinol-cytochrome-c reductase (complex III), and cytochrome-c oxidase (complex IV), in skeletal muscle biopsies from 7 patients with confirmed mtDNA depletion. In one patient there was no evidence of an ETC defect. However, the remaining 6 patients exhibited reduced complex I and IV activities. Five of these patients also displayed reduced complex II-III (succinate:cytochrome-c reductase) activity. Individual measurement of complex II and complex III activities demonstrated normal levels of complex II activity compared to complex III, which was reduced in the 5 biopsies assayed. These findings suggest a possible diagnostic value for the detection of normal levels of complex II activity in conjunction with reduced complex I, III and IV activity in the identification of likely candidates for mtDNA depletion syndrome

DNA, Mitochondrial↗

Multidrug resistant neonatal sepsis in Peshawar, Pakistan.

OBJECTIVE: To investigate the spectrum of organisms causing neonatal sepsis in Peshawar, Pakistan and to assess their sensitivity to various groups of drugs. METHODS: Blood taken from newborn babies admitted to the special care baby unit at the Khyber Teaching Hospital with a clinical diagnosis of neonatal sepsis was cultured. The data obtained from October 1997 to December 2000 were analysed and the results tabulated. RESULTS: A total of 1598 blood cultures were taken; 1003 were positive (positivity rate 62.8%). Escherichia coli was the most common organism found (36.6%), followed by Staphylococcus aureus (29.5%), Pseudomonas (22.4%), Klebsiella (7.6%), and Proteus (3.8%). No group B streptococcus was grown. Listeria monocytogenes was found in one cerebrospinal fluid culture. E coli and Pseudomonas showed a high degree of resistance to commonly used antibiotics (ampicillin, augmentin, and gentamicin), a moderate degree of resistance to cephalosporin (cefotaxime, ceftzidime, and ceftrioxone), and low resistance to drugs not used for newborn babies (ofloxacin, ciprofloxacin, and enoxabid). S aureus showed a low resistance to all three groups of antibiotics. CONCLUSION: Neonatal sepsis remains one of the leading causes of neonatal admission, morbidity, and mortality in developing countries. Gram negative organisms are the major cause of neonatal sepsis in Peshawar. Such organisms have developed multidrug resistance, and management of patients infected with them is becoming a problem in developing countries.

Anti-Bacterial Agents↗

Acquisition of eyeblink conditioning is critically dependent on normal function in cerebellar cortical lobule HVI.

Classical conditioning of the nictitating membrane response (NMR)/eyeblink response of rabbits is a simple form of cerebellar-dependent, associative motor learning. Reversible inactivations of the cerebellar nuclei and inferior olive have implicated the olivo-cortico-nuclear loop in the acquisition of nictitating membrane conditioning, but the role of the cerebellar cortex in acquisition has not been tested directly. Here we have used local infusions of the water-soluble, disodium salt of 6-cyano-7-nitroquinoxaline-2,3-dione reversibly to block cerebellar cortical AMPA/kainate receptors in lobule HVI during acquisition training. After the drug effects dissipated, there was no evidence that acquisition had taken place; the subjects behaved as if naive. Further training without inactivation then allowed normal acquisition, and further inactivations during performance of conditioned responses abolished these established responses. There was a strong correlation between the inactivation effects on acquisition and subsequent inactivation effects on performance, indicating that the same eyeblink-control cortical microzones are engaged in learning and expressing this behavior. The cortical component of the olivo-cortico-nuclear loop is essential for acquisition of classically conditioned nictitating membrane response learning, and eyeblink control areas in HVI are critical. Our findings are consistent with models of cerebellar learning that assign essential plasticity to the cortex or to a distribution between levels in olivo-cortico-nuclear modules.

6-Cyano-7-nitroquinoxaline-2,3-dione↗

Decision making and neuropsychiatry.

Abnormal decision making is a central feature of neuropsychiatric disorders. Recent investigations of the neural substrates underlying decision making have involved qualitative assessment of the cognition of decision making in clinical lesion studies (in patients with frontal lobe dementia) and neuropsychiatric disorders such as mania, substance abuse and personality disorders. A neural network involving the orbitofrontal cortex, ventral striatum and modulatory ascending neurotransmitter systems has been identified as having a fundamental role in decision making and in the neural basis of neuropsychiatric diseases. This network accounts for the dissociations among decision-making deficits in different clinical populations. Ultimately, a more refined and sophisticated characterization of such deficits might guide the early diagnosis and cognitive and therapeutic rehabilitation of these patients.

Journal Article↗