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Biomedical subjects

M S Ali

Publications and source records attributed to M S Ali.

At least 73 records · Page 4Linked to original sources
PubMed1995

Neurologic changes in visceral leishmaniasis.

Neurologic changes in visceral leishmaniasis (VL) are rarely reported. From January 1992 to April 1993, 111 patients with VL were seen at Soba University Hospital in Khartoum, Sudan. Fifty-two (46%) patients had neurologic symptoms or signs; the most common symptom was a sensation of burning feet. Four patients had foot drop. Five patients had deafness and one patient had multiple cranial nerves palsies. None of our patients had vitamin deficiency or any of the other known causes of neuropathy. Nerve conduction studies in 15 patients showed evidence of axonal degeneration and demyelination, which were confirmed by histopathology and electron microscopy of nerve biopsies. There was no direct parasitic infection of the nerve and there was no neuritis. In most patients, the sensory symptoms disappeared within two weeks in most of our patients after specific anti-leishmanial treatment. Motor recovery was much slower. Audiographic studies in five patients with deafness showed it to be sensory-neural. Hearing returned to normal after treatment with sodium stibogluconate. Further studies are needed to define the etiology of the nerve pathology in patients with VL.

Adolescent↗
PubMed1995

Airway protection by the laryngeal mask airway in children.

The pediatric laryngeal mask airway (LMA) is a scale-down version of the adult form, and no direct postmortem specimen work has been performed so far. There are several anatomical differences between pediatric and adult airways, and hence, the scale-down version of the adult LMA is not necessarily water-tight in pediatric patients. We performed a prospective study to assess airway protection by the LMA in pediatric patients, using methylence blue (injected in the pharynx outside the LMA) and the fibreoptic bronchoscope to view the inside of the mask, to detect any leakage of the dye. Fifty Patients (40 boys and 10 girls) aged 1-10 years (mean 4.5 yr) were studied. All patients underwent surgery below the level of the umbilicus, under light general anesthesia combined with caudal epidural block. All patients were allowed to breath spontaneously over an Ayre's T-piece. Dye staining of the inside of the mask was detected in 5 patients (10%). The esophageal opening was visualized within the mask in 3 patients (6%). No serious complications occurred in any of our patients.

Anesthesia↗
PubMed1994

Chemical constituents of sapindus mukorossi gaertn. (Sapindaceae).

Six new fatty esters of tetracyclic triterpenoid (1-6) together with a known acyclic sesquiterpenoidal glycoside (7) have been isolated from the fruits of Sapindus mukorossi belonging to the family Sapindaceae. Their structures were elucidated with the help of extensive spectroscopic techniques and by chemical means.

Journal Article↗
PubMed1993

Identification of the essential cysteine residue in the active site of bovine pyruvate dehydrogenase.

Pyruvate dehydrogenase (E1), the first catalytic component of the bovine pyruvate dehydrogenase complex, is composed of two nonidentical subunits in a tetrameric alpha 2 beta 2 form. The sulfhydryl-specific reagent N-ethylmaleimide (NEM) was used to identify the reactivities and function of cysteinyl residues and subsequent identification of these residues in the active site of bovine E1. Treatment of E1 with 0.2 mM NEM resulted in loss (90%) of enzymatic activity; the inactivation followed bimolecular reaction kinetics. The inactivation was almost entirely prevented by thiamin pyrophosphate (TPP) and pyruvate; protection is probably due to formation of the hydroxyethylidene-TPP intermediate. To identify the reactive cysteinyl residues in the active site region, the nonessential SH groups in E1 were first modified with NEM in the presence of TPP and pyruvate. After quenching with dithiothreitol and removal of the substrate and cofactor by dialysis, the modified E1 was treated with [14C]NEM to label the exposed cysteinyl residue(s) in or near the active site region. The data indicate that NEM reacted in the active site region of the E1 component with a stoichiometry of 2 mol of [14C]NEM bound per mol of E1 tetramer. The initial rapid labeling of E1 with [14C]NEM established that incorporation was predominantly into the alpha subunit. A single radiolabeled peptide was isolated following V8 protease digestion of radiolabeled E1 by [14C]NEM. Sequence analysis of the labeled peptide derived from bovine E1 demonstrated that the labeled cysteinyl residue was equivalent to Cys-62 in the alpha subunit (mature form) of human E1.

Amino Acid Sequence↗
PubMed1993

Prevalence of cutaneous leishmaniasis along the Nile River north of Khartoum (Sudan) in the aftermath of an epidemic in 1985.

Based on a pilot clinical study of the prevalence of cutaneous leishmaniasis (CL) among school children in villages on both banks of the Nile River north of Khartoum, Sudan in the aftermath of a 1985 epidemic, we studied a random sample (303 individuals) from one of these villages to determine the prevalence of infection and exposure to CL. Four percent of the population had active CL lesions, 47% had healed lesions, and another 43% reacted positively to sensitization with leishmanin in the absence of past or active CL lesions. Ninety-one percent of the total population reacted positively to leishmanin. The present status of CL in the area and possible reasons for the emergence of the epidemic are discussed, and gaps in our knowledge about the epidemic are identified.

Adolescent↗
PubMed1993

Two triterpenoidal saponins from sapindus, mukorossi gaertn.

The two triterpenoidal saponins 2 and 3 containing hederagenin aglycone moiety (1) have been isolated from the butanol soluble fraction of the fruits (without shells) of Sapindus mukorossi Gaertn. Their structures were elucidated with the aid of chemical and spectroscopic means.

Journal Article↗
PubMed1992

Clinical aspects of kala-azar in children from the Sudan: a comparison with the disease in adults.

The clinical presentation of kala-azar in 43 children and 45 adults was compared. In both groups fever, left upper quadrant abdominal pain and swelling, and weight loss were equally the most common presenting symptoms. Lymphadenopathy was observed in 86 per cent of children and 76 per cent of adults. Splenomegaly was absent in 2 per cent of children and 7 per cent of adults. No significant difference was found in frequency distribution of symptoms and signs between children and adults. Haematological indices were compared in both children and adults with kala-azar and their control groups. In both children and adults with kala-azar, haemoglobin concentration, total white cell count, and platelet count were significantly lower before than after treatment. Only haemoglobin concentration was lower in children with kala-azar as compared with adults with the disease. Children in the control group had lower haemoglobin and higher total white cell count than adult controls. Response to therapy was evaluated in 693 patients. Two-hundred-and-fifty children and 373 adults were treated with sodium stibogluconate 10 mg/kg for 30 days; in both groups 12 per cent deaths and 4 per cent relapses occurred. Thirty children and 40 adults were treated with sodium stibogluconate 2 x 10 mg/kg for 15 days. In children, 3 per cent deaths and 7 per cent relapses were noted; in adults there were 8 per cent deaths and 5 per cent relapses. No significant difference in death rate or relapse rate was found between children and adults in both regimens. Both regimens performed equally well in children and adults with regard to death rate and relapse rate.

Adolescent↗
PubMed1992

Post-kala-azar dermal leishmaniasis in the Sudan: peripheral neural involvement.

Four patients developed post-kala-azar dermal leishmaniasis and neuritis (PKDL) 1 to 6 months following apparently successful treatment of kala-azar. The duration of the lesion varied between 1 month and nearly 5 years. The lesions were macules, papules, or nodules affecting the face, extremities, and trunk. The diagnosis was made by demonstration of the parasite in slit smear and biopsies and by a positive direct agglutination test (DAT). Histologically, the patients were found to have neuritis affecting the cutaneous nerves in the lesion only. The nerves showed a lymphohistiocytic infiltration and occasionally parasites. There was no impairment of sensation. Response to sodium stibogluconate was good. PKDL may simulate leprosy both clinically and pathologically.

Adult↗
PubMed1992

An unusual cause of carpal tunnel syndrome. Case report.

A 38 year old woman with carpal tunnel syndrome of the right hand was treated with operative decompression, initially successfully. Subsequently, she developed a compartment syndrome after an injury. On re-exploration, an accessory palmaris longus muscle was encasing the median nerve at the distal forearm and passing through the flexor sheath, underneath the flexor retinaculum, inserted into the deep palmar fascia.

Adult↗
PubMed1992

Congenital kala-azar and leishmaniasis in the placenta.

During an epidemic of visceral leishmaniasis in the Sudan, two cases of congenital kala-azar were seen. The first child, whose mother had contracted kala-azar in southern Sudan, was born in Khartoum, where no transmission of leishmaniasis is currently occurring. At seven months, the child had fever, lymphadenopathy, and hepatosplenomegaly; leishmania parasites were detected in the bone marrow. The child died and an autopsy showed leishmania parasites in all tissues including the lungs, kidneys, and thymus. In the second case, parasites were found in the placenta of a five-month-old fetus. These two cases demonstrate the importance of follow-up of infants born to mothers with leishmaniasis.

Adult↗
PubMed1990

Carbon fibre composite bone plates. Development, evaluation and early clinical experience.

We compared the mechanical properties of carbon fibre composite bone plates with those of stainless steel and titanium. The composite plates have less stiffness with good fatigue properties. Tissue culture and small animal implantation confirmed the biocompatibility of the material. We also present a preliminary report on the use of the carbon fibre composite plates in 40 forearm fractures. All fractures united, 67% of them showing radiological remodelling within six months. There were no refractures or mechanical failures, but five fractures showed an unexpected reaction; this is discussed.

Adult↗
PubMed1989

Effects of nicorandil on left ventricular hemodynamics and volume at rest and during exercise-induced angina pectoris.

The hemodynamic effects of nicorandil (20 mg) were compared with placebo in a double-blind study of 20 patients with angiographically proved coronary artery disease at rest before and 7, 15, 30 and 60 minutes after oral dosing. The impact of the drug on left ventricular (LV) hemodynamics and volume during exercise-induced angina was determined by repeating exercise 60 minutes after drug administration, at the same work load that reliably induced angina during control predrug exercise. At rest, nicorandil reduced all components of systemic arterial pressure without change in cardiac or stroke volume indexes or heart rate. Pulmonary artery occluded pressure was reduced without change in LV ejection fraction or systemic vascular resistance index. Effects were evident at 7 minutes and peaked at 30 minutes with attenuation at 60 minutes. Compared with control supine bicycle exercise, the drug (at 60 minutes) reduced mean systemic arterial pressure and LV filling pressure without change in cardiac stroke volume indexes and heart rate. There was a smaller increase in LV ejection fraction. These data suggested greatest impact on LV function during exercise when substantial decreases in filling pressure occurred at maintained cardiac pumping indexes.

Adult↗
PubMed1989

Fractures of the fifth metacarpal neck: is reduction or immobilisation necessary?

Sixty two patients with fractures of the neck of the little finger metacarpal have been studied. Treatment consisted of unrestricted exercises without any splintage or attempts at reduction, irrespective of the degree of angulation of the fractures. Patients were reviewed at one or two-weekly intervals until movement had recovered and return to work was possible. One year after injury, patients were recalled for examination. Recovery was rapid with no long-term functional restriction, although 14% of patients noted minor cosmetic deformity.

Adolescent↗
PubMed1989

Segmental spinal instrumentation. A study of the mechanical properties of materials used for sublaminar fixation.

Segmental spinal instrumentation with sublaminar fixation is widely used but a variety of materials and techniques are being employed for both scoliosis and other spinal surgery. This study addresses the question as to which is best. Both the materials and the methods of securing them were studied. The materials tested were stainless steel 316L, Ortron 90 high nitrogen steel, titanium alloys, nylon straps, and Mersilene tapes. Doubled cold-worked 00.84-mm diameter stainless steel formed in a knot with a twist proved to be the strongest and most secure means of fixation with a yield value of 1,610 N. Attention to the details of technique and material such as the incorporation of a secondary twist and avoidance of hot-worked stainless steel may reduce the incidence of implant failure.

Bone Wires↗
PubMed1987

Ankle fractures in the elderly: nonoperative or operative treatment.

One hundred consecutive patients over the age of 60 years with unstable fractures of the ankle were retrospectively reviewed. Fifty were treated operatively and 50 nonoperatively. The mean follow-up was 7 years (2-16 years). Satisfactory reduction was a prerequisite in both groups. Patient satisfaction with regard to pain, deformity, and stability was significantly better in the operated group. The high proportion of poor final results in the nonoperatively treated group correlated well with malunion and nonunion.

Aged↗
PubMed1986

Golgi-specific localization of transglycosylases engaged in glycoprotein biosynthesis in suspension-cultured cells of sycamore (Acer pseudoplatanus L.).

Golgi complex and endoplasmic reticulum (ER) were isolated from suspension-cultured cells of sycamore (Acer pseudoplatanus L.) by stepwise sucrose density gradient centrifugation using protoplasts as starting material. The purity of the two organelle fractions isolated was assessed by measuring marker enzyme activities. Localization of glycolipid and glycoprotein glycosyltransferase activities in the isolated Golgi and ER fractions was examined; three glycosyltransferases, i.e., galactosyltransferase, fucosyltransferase, and xylosyltransferase, proved to be almost exclusively confined to the Golgi, whereas the ER fractions contained glycolipid glycosyltransferase. The Golgi complex was further subfractionated on a discontinuous sucrose density gradient into two components, migrating at densities of 1.118 and 1.127 g/cm3. The two fractions differed in their compositional polypeptide bands discernible from Na-dodecylsulfate gel electrophoresis. Galactosyltransferase distributed nearly equally between the two protein peaks and xylosyltransferase activities using the endogenous acceptor also appeared to be localized in the two subcompartments. By contrast, fucosyltransferase, engaged in the terminal stage of glycosylation, banded in the lower density fractions. Golgi-specific alpha-mannosidase, which is presumably engaged in the sugar trimming of Asn-N-linked glycoprotein carbohydrate core, was enriched fourfold in specific activity in the fractions of the higher density. The overall experimental results indicate that the cotranslational glycosylation of Asn-N-linked glycoproteins, e.g., polyphenol oxidase (laccase), takes place in the ER, while subsequent post-translational processing of the oligosaccharide moiety proceeds successively in the two physically separable compartments of the Golgi complex.

Endoplasmic Reticulum↗
PubMed1986

Association of H-Translocating ATPase in the Golgi Membrane System from Suspension-Cultured Cells of Sycamore (Acer pseudoplatanus L.).

The Golgi complex and the disrupted vesicular membranes were prepared from suspension-cultured cells of sycamore (Acer pseudoplatanus L.) using protoplasts as the starting material and employing linear sucrose density gradient centrifugation followed by osmolysis (Ali et al. [1985] Plant Cell Physiol 26: 1119-1133). The isolated Golgi fraction was found to be enriched with marker enzyme activities and depleted of the activity of a typical mitochondrial marker enzyme, cytochrome c oxidase. Golgi complex, and vesicular membranes derived thereof were found to contain the specific ATPase (specific activity of about 0.5 to 0.7 micromoles per minute per milligram protein). Inhibitor studies suggested that the ATPase of Golgi was different from plasma membrane, tonoplast and mitochondrial ATPases as it was not inhibited by sodium vanadate, potassium nitrate, oligomycin and sodium azide. The sensitivity to N-ethylmaleimide further distinguished the Golgi ATPase from F(0) to F(1) ATPase of mitochondria. The internal acidification was measured by monitoring the difference in absorbance at 550 nanometers minus 600 nanometers using neutral red as a probe. The maximum rate detected with Golgi and disrupted membrane system was 0.49 and 0.61 optical density unit per minute per milligram protein, at pH 7.5, respectively, indicating that the proton pump activity was tightly associated with the Golgi membranes. In both cases, the acidification was inhibited 70 to 90% by various ionophores, indicating that the proton pump was electrogenic in nature. Both the Golgi ATPase activity and ATP-dependent acidification were profoundly inhibited by N,N'-dicyclohexylcarbodiimide, which also indicate that the two activities are catalyzed by the same enzyme.

Journal Article↗