Biomedical subjects

M Ahmed

Publications and source records attributed to M Ahmed.

At least 109 records · Page 6Linked to original sources

PubMed2000

Analgesic principle from Abutilon indicum.

Bioactivity guided isolation of Abutilon indicum yielded eugenol [4-allyl-2-methoxyphenol], which was found to possess significant analgesic activity. At doses of 10, 30, and 50 mg/kg body weight, eugenol exhibited 21.30 (p < 0.05), 42.25 (p < 0.01) and 92.96% (p < 0.001) inhibition of acetic acid induced writhing in mice. At a dose of 50 mg/kg body weight, eugenol showed 33.40% (p < 0.05) prolongation of tail flicking time determined by the radiant heat method.

Acetates↗

PubMed2000

A comparison of dissection-method and diathermy tonsillectomies.

OBJECTIVE: To compare the dissection and diathermy methods of tonsillectomy and evaluate their advantages and disadvantages during surgery and convalescence. METHODS AND SETTING: Patients who had tonsillectomy at Aga Khan University Hospital, between January 1994-December 1997. RESULTS: Four year retrospective analysis was done of 200 patients who underwent tonsillectomy by either electrocautery or dissection method. One hundred and eleven underwent tonsillectomy by electrocautery and the other 79 had their tonsils removed by dissection-method and 2 had a combination of both. The average intra-operative blood loss was 10 ml with cautery and 65 ml with dissection method. The average operative time was 15.7 minutes with cautery and 26.9 minutes for dissection. We found higher amounts of blood loss and intra-operative time with dissection method than electrocautery. In comparing diathermy dissection method tonsillectomies, there was marked diffference between two, in peri-operative blood loss and operative time. CONCLUSION: Although post-operative bleeding, pain and infection are complications of both techniques and in our study their incidence in similar in both, but intra-operative blood loss and time are two important factors, based on which we can conclude that electrocautery technique is a more effective technique in our set up.

Adolescent↗

PubMed2000

The histopathology of routine tonsillectomy specimens: results of a study and review of literature.

Controversy continues to attend the routine histologic examination of tonsillectomy specimens. We performed a retrospective evaluation of 400 tonsil specimens removed from 200 patients. We found that 68.3% of the specimens contained reactive lymphoid hyperplasia, 13.5% had follicular hyperplasia, 10.0% represented acute or chronic tonsillitis, and 7.5% were normal. Only one case of malignancy was detected: a non-Hodgkin's lymphoma in one tonsil of a patient who was a cigarette smoker and who had asymmetric tonsils. The results of our study, taken in combination with data already published in the literature, indicate that routine histologic examination of tonsillectomy specimens is unnecessary and results only in added costs and a loss of man-hours. However, in patients who have certain preoperative risk factors, a histopathologic evaluation of tonsillar specimens remains mandatory.

Adolescent↗

PubMed2000

Knowledge and attitude of health professionals in relation to the integration of leprosy control into the general health service in Ethiopia.

Since the introduction of multidrug therapy for leprosy patients, the integration of leprosy control in the general health service (GHS) system has been an issue of debate. In Ethiopia, the present policy stresses integrated management of diseases. In spite of the policy, however, leprosy control was a vertical program until 1998 in most parts of the country. A descriptive cross-section study was conducted in the southern region of Ethiopia from October 1996 to March 1997 to determine the levels of involvement of the GHS staff and to identify obstacles to their involvement in the management of leprosy patients. Through a written questionnaire, data were collected from 240 GHS staff, including doctors, nurses and health assistants. It was found that 6% of the GHS staff was involved in leprosy control activities, mainly case finding and health education. Negative attitudes toward leprosy workers were held by 13% of the GHS staff while 40% had intermediate attitudes and the remaining 47% had positive attitudes. Statistically significant differences were found with regard to the level of knowledge among different health professionals, type of health institutions and years of service. The levels of involvement, knowledge and attitude of GHS staff showed that lack of integration and training were core problems. Hence, policy makers should give due attention to promoting the involvement of the GHS staff by integrating the program into the GHS system using the approach already in place in certain parts of the country.

Attitude of Health Personnel↗

PubMed2000

Solidification as low cost technology prior to land filling of industrial hazardous waste sludge.

The aim of this study is to stabilize and solidify two different treated industrial hazardous waste sludges, which were selected from factories situated close to Alexandria. They were selected to ensure their safe transportation and landfill disposal by reducing their potential leaching of hazardous elements, which represent significant threat to the environment, especially the quality of underground water. The selected waste sludges have been characterized. Ordinary Portland Cement (OPC), Cement Kiln Dust (CKD) from Alexandria Portland Cement Company, and Calcium Sulphate as a by-product from the dye industry were used as potential solidification additives to treat the selected treated waste sludges from tanning and dyes industry. Waste sludges as well as the solidified wastes have been leach-tested, using the General Acid Neutralization Capacity (GANC) procedure. Concentration of concerning metals in the leachates was determined to assess changes in the mobility of major contaminants. The treated tannery waste sludge has an acid neutralization capacity much higher than that of the treated dyes waste sludge. Experiment results demonstrated the industrial waste sludge solidification mix designs, and presented the reduction of contaminant leaching from two types of waste sludges. The main advantages of solidification are that it is simple and low cost processing which includes readily available low cost solidification additives that will convert industrial hazardous waste sludges into inert materials.

Coloring Agents↗

PubMed1999

Effects of nasal O2 on sleep-related disordered breathing in ambulatory patients with stable heart failure.

OBJECTIVE: The purpose of this study was 1) to determine the effects of nasal O2 on periodic breathing, arterial oxyhemoglobin desaturation and nocturnal ventricular arrhythmias in patients with heart failure and 2) determine the characteristics of patients whose periodic breathing will be reversed by O2 administration; our hypothesis was that patients with more severe periodic breathing and desaturation, will respond more favorably to oxygen. DESIGN: Prospective study. SETTING: Referral sleep laboratory of a Department of Veterans Affairs Medical Center. PARTICIPANTS: 36 ambulatory male patients with heart failure whose initial polysomnograms showed periodic breathing with fifteen or more episodes of apnea (A) and hypopnea (H) per hour (AH index, AHI) were treated with nasal O2 during the subsequent full night polysomnography. INTERVENTIONS: Oxygen. MEASUREMENTS AND RESULTS: Arterial blood gases and hydrogen ion concentrations were measured, and cardiac radionuclide ventriculography, Holter monitoring, and polysomnography were done. The studies were scored blindly. Treatment with O2 resulted in a significant reduction in AHI (49+/-19 vs 29+/-29, means+/-SD), central apnea index (28+/-23 vs 13+/-18 per hour), and the percent of total sleep time below an arterial oxyhemoglobin saturation of 90% (23+/-21% vs 0.8+/-2.3%). In spite of virtual normalization of saturation with O2 therapy, the number of ventricular arrhythmias during sleep did not change significantly. In 39% of the patients (14 out of 36), O2 therapy resulted in reversal of central sleep apnea (defined by a reduction in AHI to less than 15/hr). In this group, the AHI decreased by 78% which was significantly (p=0.0001) more than improved (22%) in AHI of the remaining patients (n=22). The main differences between baseline characteristics of the two groups was a significantly higher mean PaCO2 in patients who did respond fully to O2 (39.3+/-5.4 vs 36.1+/-4.2 mm Hg, p=0.03). In both groups, however, O2 administration resulted in significant and similar improvement in arterial oxyhemoglobin saturation (saturation <90%, percent total sleep time 0.1+/-0.3% vs 1+/-3%). CONCLUSION: In patients with stable heart failure, administration of nasal O2 significantly improves periodic breathing and virtually eliminates clinically significant arterial oxyhemoglobin desaturation. The beneficial effects of O2, however, may be modulated by the level of arterial PCO2. Acute O2 therapy has important benefits on sleep apnea and nocturnal arterial oxyhemoglobin desaturation in heart failure patients. Long term benefits of O2 therapy in heart failure and sleep apnea need to be determined.

Aged↗

PubMed1999

Metal binding specificity in carbonic anhydrase is influenced by conserved hydrophobic core residues.

The role of highly conserved aromatic residues surrounding the zinc binding site of human carbonic anhydrase II (CAII) in determining the metal ion binding specificity of this enzyme has been examined by mutagenesis. Residues F93, F95, and W97 are located along a beta-strand containing two residues that coordinate zinc, H94 and H96, and these aromatic amino acids contribute to the high zinc affinity and slow zinc dissociation rate constant of CAII [Hunt, J. A., and Fierke, C. A. (1997) J. Biol. Chem. 272, 20364-20372]. Substitutions of these aromatic amino acids with smaller side chains enhance the copper affinity (up to 100-fold) while decreasing the affinity of both cobalt and zinc, thereby altering the metal binding specificity up to 10(4)-fold. Furthermore, the free energy of the stability of native CAII, determined by solvent-induced denaturation, correlates positively with increased hydrophobicity of the amino acids at positions 93, 95, and 97 as well as with cobalt and zinc affinity. Conversely, increased copper affinity correlates with decreased protein stability. Zinc specificity is therefore enhanced by formation of the native enzyme structure. These data suggest that the hydrophobic cluster in CAII is important for orienting the histidine residues to stabilize metals bound with a distorted tetrahedral geometry and to destabilize the trigonal bipyramidal geometry of bound copper. Knowledge of the structural factors that lead to high metal ion specificity will aid in the design of metal ion biosensors and de novo catalytic sites.

Amino Acids↗

PubMed1999

Sensory neuropeptidergic pattern in tendon, ligament and joint capsule. A study in the rat.

The normal occurrence of sensory neuropeptides in tendons, ligaments and joint capsules in the rat was analyzed by immunohistochemistry and radioimmunoassay (RIA). Nerve fibres immunoreactive to substance P (SP), calcitonin gene-related peptide (CGRP), neurokinin A, galanin and somatostatin were identified in the Achilles tendon as well as the collateral ligaments and joint capsule of the knee. The neuropeptidergic fibres were predominantly found in the epiligament and paratenon. However, SP- and CGRP-positive fibres were also seen in the proper ligament and tendon tissues. RIA showed higher concentrations of SP and CGRP in tendons than in ligaments and capsules. The morphological and quantitative data obtained on sensory neuropeptides in normal tendons, ligaments and joint capsules may be used as a reference for tissue analysis in painful and inflammatory conditions of the locomotor apparatus.

Achilles Tendon↗

PubMed1999

Accelerated transcription of PRPS1 in X-linked overactivity of normal human phosphoribosylpyrophosphate synthetase.

Phosphoribosylpyrophosphate (PRPP) synthetase (PRS) superactivity is an X-linked disorder characterized by gout with overproduction of purine nucleotides and uric acid. Study of the two X-linked PRS isoforms (PRS1 and PRS2) in cells from certain affected individuals has shown selectively increased concentrations of structurally normal PRS1 transcript and isoform, suggesting that this form of the disorder involves pretranslational dysregulation of PRPS1 expression and might be more appropriately termed overactivity of normal PRS. We applied Southern and Northern blot analyses and slot blotting of nuclear runoffs to delineate the process underlying aberrant PRPS1 expression in fibroblasts and lymphoblasts from patients with overactivity of normal PRS. Neither PRPS1 amplification nor altered stability or processing of PRS1 mRNA was identified, but PRPS1 transcription was increased relative to GAPDH (3- to 4-fold normal in fibroblasts; 1.9- to 2.4-fold in lymphoblasts) and PRPS2. Nearly coordinate relative increases in each process mediating transfer of genetic information from PRPS1 transcription to maximal PRS1 isoform expression in patient fibroblasts further supported the idea that accelerated PRPS1 transcription is the major aberration leading to PRS1 overexpression. In addition, modulated relative increases in PRS activities at suboptimal Pi concentration and in rates of PRPP and purine nucleotide synthesis in intact patient fibroblasts indicate that despite an intact allosteric mechanism of regulation of PRS activity, PRPS1 transcription is a major determinant of PRPP and purine synthesis. The genetic basis of disordered PRPS1 transcription remains unresolved; normal- and patient-derived PRPS1s share nucleotide sequence identity at least 850 base pairs 5' to the consensus transcription initiation site.

Allosteric Regulation↗

PubMed1999

Mutually exclusive expression patterns of Bcl-2 and Par-4 in human prostate tumors consistent with down-regulation of Bcl-2 by Par-4.

Par-4 is a widely expressed protein that sensitizes both prostatic and non-prostatic cells to apoptosis. Constitutive- or regulated- overexpression of Par-4 caused a reduction in the levels of the anti-apoptotic protein Bcl-2. Replenishment of Bcl-2 levels abrogated susceptibility to Par-4-dependent apoptosis, suggesting that Par-4-mediated apoptosis requires downmodulation of Bcl-2 levels. The inverse correlation between Par-4 and Bcl-2 expression was recapitulated in human prostate tumors. Par-4 but not Bcl-2 was detected in the secretory epithelium of benign prostatic tumors and in primary and metastatic prostate cancers that are apt to undergo apoptosis. Moreover, xenografts of human, androgen-dependent CWR22 tumors showed Par-4 but not Bcl-2 expression. By contrast, androgen-independent CWR22R tumors derived from the CWR22 xenografts showed mutually exclusive expression patterns of Par-4 and Bcl-2. These findings suggest a mechanism by which Par-4 may sensitize prostate tumor cells to apoptosis.

3T3 Cells↗

PubMed1999

The role of depression in pain, psychophysiological syndromes and medically unexplained symptoms associated with chronic fatigue syndrome.

BACKGROUND: The association between depression and pain, function, medically unexplained symptoms and psychophysiological syndromes such as irritable bowel syndrome has not been explored before in chronic fatigue syndrome. METHODS: Cross-sectional controlled study of the current prevalence of psychophysiological syndromes, pain, function and lifetime prevalence of medically unexplained symptoms in 77 out-patients with chronic fatigue syndrome (CFS) without DSM-III-R depression, 42 CFS out-patients with DSM-III-R depression and 26 out-patient with primary DSM-III-R depression. RESULTS: Both CFS groups differed significantly from the primary depression group but not each other in the prevalence of tension headaches (P < 0.001), reporting of widespread bodily pain (P < 0.001) and the number of lifetime medically unexplained symptoms (P < 0.001). The three groups did not significantly differ in the prevalence of irritable bowel syndrome or fibromyalgia. CFS patients with depression were more impaired in social function than other CFS patients. CONCLUSION: Depression is not associated with the reporting of pain, psychophysiological syndromes and medically unexplained symptoms in CFS patients. Depression is associated with decreased social function in CFS patients. LIMITATIONS: Study depended on recall of symptoms, not confirmed by medical records and current investigations. Patients with depression were taking antidepressants. CLINICAL RELEVANCE: Treating depression in chronic fatigue syndrome is unlikely to diminish reporting of pain and medically unexplained symptoms but may improve social function.

Adult↗

PubMed1999

Cellular radiosensitivity of patients with papillary thyroid cancer.

Cultured skin fibroblasts from patients with papillary (differentiated) thyroid carcinomas were compared to those from healthy subjects, ataxia telangiectasia (AT) homozygotes and AT heterozygotes for colony-forming ability after low dose-rate irradiation, and post-irradiation DNA synthesis as indicated by uptake of [3H]-thymidine. The cells from the cancer patients exhibited enhanced radiosensitivity (intermediate between normal and AT) and less than normal level of radioinduced inhibition of DNA synthesis.

Adult↗

PubMed1999

High pre-treatment serum hepatitis B virus titre predicts failure of lamivudine prophylaxis and graft re-infection after liver transplantation.

BACKGROUND/AIMS: Orthotopic liver transplantation has an established role for the treatment of patients with chronic liver failure secondary to hepatitis B virus (HBV) infection. Unfortunately, recurrent infection of the graft can be associated with aggressive disease, and with diminished graft and patient survival. Currently, the role of nucleoside analogues for prevention of graft re-infection is being evaluated. Preliminary results are encouraging, but treatment failure has been associated with emergence of drug-resistant virus. METHODS: We have studied ten consecutive patients who received lamivudine prophylaxis for prevention of HBV graft reinfection. Sequential sera, collected prelamivudine then during treatment before and after liver transplantation, were examined. Conventional serological markers were measured, as were serum viral DNA levels with a sensitive quantitative polymerase chain reaction assay. RESULTS: Lamivudine treatment effected a reduction in serum HBV levels, but six patients still had measurable viral DNA at the time of transplantation. Five patients developed graft re-infection with lamivudine-resistant virus. Resistant virus emerged 8 to 15 months post-transplant. The likelihood of emergence of resistant virus was related to the pre-treatment serum HBV titre. Persistent serum viral DNA positivity and evidence of graft re-infection during the early post-transplant period did not predict the subsequent emergence of resistant virus. CONCLUSIONS: Our observations suggest that the resistant species may be present in the viral quasispecies in the serum and liver of patients with high-level replication prior to lamivudine exposure. The resistant species can persist during lamivudine treatment prior to transplantation, and emerge following transplantation. These observations suggest strategies which might prevent the emergence of drug-resistant species, and imply that graft re-infection may be a preventable phenomenon.

Antiviral Agents↗

PubMed1999

Autonomic neuropeptides in the interface membrane of aseptic loose hip prostheses.

We analyzed the presence of autonomic nerve fibers in the interface membranes (n = 9) surrounding aseptic loosened hip prostheses by immunohistochemistry. The study focused on the autonomic messengers neuropeptide Y (NPY), tyrosine hydroxylase (TH), the rate-limiting enzyme in the synthesis of noradrenaline (NA), and vasoactive intestinal polypeptide (VIP). Protein gene product (PGP) 9.5, a general marker of peripheral nerve fibers, was also analyzed to establish the neuronal character of the immunoreactive structures. PGP 9.5-positive and NPY-positive nerve fibers were identified in all 9 samples, and VIP-immunoreactive and TH-immunoreactive fibers were found in 7. There was a difference in the distribution of nerve fibers both between and within the samples. Among the neuropeptides analyzed, NPY was most abundant. NPY-positive and TH-positive fibers were predominantly found around the blood vessel walls forming varicose nerve terminals. VIP-positive fibers were mainly observed as thin varicose nerve terminals with no relationship to blood vessels. Autonomic neuropeptides exert not only vasoactive and immunoregulatory effects, but also have been found to have direct effects on bone tissue. Moreover, the autonomic nervous system has been strongly implicated in nociception and inflammation. Neuronal NPY, TH, and VIP in the interface membrane may prove to contribute to the pathologic mechanisms leading to aseptic loosening of hip prostheses.

Aged↗

PubMed1999

Histological progression during short-term follow-up of patients with chronic hepatitis C virus infection.

Assessment of prognosis from hepatitis requires liver histology. When the fibrosis stage is known, and if the fibrosis progression rate can be established, time to development of cirrhosis can be calculated. The fibrosis progression rate can be calculated from a single biopsy when duration of infection prior to biopsy is known. Sequential biopsies can also be examined. In this work, we studied histological activity and fibrosis stage in liver biopsies of 157 hepatitis C virus (HCV)-infected patients, including 92 for whom the approximate duration of infection was known. The mean fibrosis progression rate was 0.09 units per year, and was not influenced by mode of infection or viral genotype. Forty-six patients who had very mild histological changes in the initial biopsy underwent repeat biopsy 2 years later (with no intervening anti-viral treatment). Comparison of paired biopsies confirmed a tendency to histological progression and increasing hepatic fibrosis (mean, 0.15 fibrosis units per year). A normal baseline alanine aminotransferase (ALT) value was associated with slow fibrosis progression before baseline biopsy and between biopsies. These data do not differ from published cross-sectional and longitudinal studies, and suggest that histological progression will be observed during follow-up of most patients, including those with mild histological changes at time of initial assessment.

Adult↗

PubMed1999

Survey of surgical emergencies in a rural population in the Northern Areas of Pakistan.

OBJECTIVE: To determine the incidence of specific surgical emergencies in a mountainous rural community in the Northern Areas of Pakistan and to assess use of existing health services, and outcomes related to acute surgical illness events. METHOD: A cross-sectional population-based survey was conducted. Interviewers visited each of 118 villages in the study area (population 100000), selected a random sample from a total of 9900 households, and interviewed the oldest premenopausal female member (n = 836). Questions were focused on injury, acute abdomen, and/or maternal morbidity occurring in the past year. Cases were included as surgical emergencies when one or more index clinical features indicating a potential for surgical intervention were present. Mortality from a wider range of surgical emergencies was also elicited based on the respondent's lifetime knowledge of the household. RESULTS: The incidence rates were 1531/100000 persons per year for injuries; 1364/100000 for acute abdomen, and 16462/100000 for maternal morbidity. The rate of injuries was 2.7 times higher and that of acute abdomen twice as high in males as in females. The injury rate decreased with advancing age, being 13 times higher in children < 5 years than in adults > 40. By contrast, the rate for acute abdomen showed a rise with advancing age, being 8 times higher in the > 40 age group than in under-fives. Burns, falls and road accidents, in that order, were the commonest forms of injury accounting for 82% of 138 cases. Of 43 burn casualties, 46% were in the age group < 5 years; there was no gender bias. Of 71 casualties from falls and road accidents, 85% were aged 6-40 years; there was 6 : 1 male predominance. The maternal morbidity rate was highest in the age group 25-35 years and may be attributed to the high pregnancy rate in this age bracket. Of 408 patients with acute surgical illness, 85% were managed initially at home or close to home in a health centre, dispensary or civil hospital; 32% eventually sought specialist surgical care. The overall rate for minor and major surgical procedures was 411/100000 persons per year (lowest estimate), and appeared to be low. The rate of operative deliveries at 11.8/1000 deliveries (lowest estimate) was particularly low. The mortality rates were correspondingly high: 55/100000 persons per year for injuries and for acute abdomen (lowest estimates). The maternal mortality ratio was particularly high at 8.9/1000 deliveries (lowest estimate). Annual mortality rates derived from deaths recalled during the respondent's lifetime in the household (mean period = 26 years), tended to corroborate the results of the 1-year survey. CONCLUSION: The incidence rates for broad categories of serious acute surgical illness in the study population far exceeded the rates of acute surgical intervention. Mortality rates were correspondingly high. Such evidence points to a large unmet surgical need and ought to spur improvements in the health service.

Abdomen, Acute↗

PubMed1999

Autonomic neuropathy in Type 2 diabetic patients is associated with hyperinsulinaemia and hypertriglyceridaemia.

AIMS: To clarify whether parasympathetic neuropathy in Type 2 diabetic patients is associated with features of the insulin resistance syndrome. METHODS: Blood pressures, glycaemic control (HbA1c), plasma lipids, residual beta-cell function (fasting plasma C-peptide), autonomic nerve function, urinary albumin excretion and glomerular filtration rate (Cr-EDTA clearance) were evaluated in 82 Type 2 diabetic patients (age 63+/-years) 5 years after diagnosis of diabetes. RESULTS: Parasympathetic neuropathy (an abnormal age corrected E/I ratio) was found in 24/82 (29%) patients. After adjustment for body mass index (BMI), patients with parasympathetic neuropathy had elevated fasting plasma C-peptide (P < 0.001) and triglyceride (Tg) (P < 0.05) levels compared with patients without parasympathetic neuropathy. In addition, the age corrected E/I ratio correlated inversely with Tg (r=-0.31; P<0.01) and fasting plasma C-peptide (r=-0.32; P < 0.01) in the Type 2 diabetic patients. CONCLUSION: Autonomic neuropathy 5 years after diagnosis of Type 2 diabetes is associated with an unfavourable metabolic risk profile.

Autonomic Nervous System Diseases↗

PubMed1999

Metal mesh stents for ureteral obstruction caused by hormone-resistant carcinoma of prostate.

BACKGROUND: Long-segment ureteral obstruction by hormone-refractory carcinoma of the prostate is a difficult problem to manage. J-Stents often obstruct by compression. Metal mesh stents have been used successfully in the management of extrinsic ureteral obstruction caused by malignant disease. In this paper, we review our results in three patients in terms of the defined objective of palliation. PATIENTS AND METHODS: All three patients presented with painful obstructed kidneys and renal failure from long (7-10-cm) distal ureteral strictures responding to nephrostomy drainage. Endoluminal metal mesh stents of 7 to 8-mm diameter of various lengths (depending on the size of the stricture) were implanted after antegrade balloon dilatation of the stricture by a standard technique. The case notes were reviewed for technical success, preservation of the renal units, complications, and the impact on the overall quality of life. RESULTS: All three stents were placed without any complication and showed patency on contrast study. In one patient, the stent obstructed after 5 months, necessitating placement of a nephrostomy tube. In the remaining two patients, the stents obstructed within 3 months. During these 3 months, both patients had multiple admissions for stent-related complications and other symptoms of their disease. Overall quality of life was poor for these patients. CONCLUSION: Metal mesh ureteral stents give poor palliation in distal strictures caused by hormone-refractory carcinoma of the prostate. Permanent nephrostomy may be a more acceptable alternative in these patients with short life expectancies.

Aged↗