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Biomedical subjects

M Ahmed

Publications and source records attributed to M Ahmed.

At least 19 recordsLinked to original sources
PubMed1992

Analysis of adenoid cystic carcinoma treated by radiotherapy.

The records of 41 patients with adenoid cystic carcinoma of the head and neck region who had been treated with radiotherapy were reviewed. Local control was achieved in 72.3% in the cases with primary lesions at 5 years. The prognosis for tumors that arose in the major salivary glands was better than that for tumors that arose in the minor salivary glands; however, the difference was not statistically significant. In the minor salivary glands, early-stage tumors were well controlled with the use of radiation therapy alone. In spite of the high local control rate, the disease-free survival rate of the patients at 10 years was only 20.8%. Lung metastasis determined the prognosis.

Brachytherapy↗
PubMed1992

Case report: amoebic liver abscess complicated by a hepatoduodenal fistula.

Amoebic liver abscess (ALA) is a common extra-intestinal presentation of amoebiasis caused by Entamoeba histolytica. The liver abscess may be complicated by rupture into adjacent structures. Common organs involved include thorax, peritoneum and pericardium. Rupture into the gastrointestinal tract is extremely rare. We report a patient who developed a hepatoduodenal fistula complicating an amoebic liver abscess. Suspicions were raised on finding air in the liver abscess on ultrasound scanning. Diagnosis was confirmed on a water-soluble (Gastrografin) swallow (Fig. 1 a,b). Complications of ALA are associated with a high morbidity and mortality and early diagnosis is important. To our knowledge only one previous case of a hepatoduodenal fistula complicating an ALA with radiological confirmation has been reported.

Adult↗
PubMed1992

Macroprolactinomas with suprasellar extension: effect of bromocriptine withdrawal during one or more pregnancies.

OBJECTIVE: To investigate the effects of bromocriptine withdrawal during one or more pregnancies in patients who presented with pituitary macroprolactinomas with suprasellar extension. DESIGN: Four infertile patients presenting with a macroprolactinoma with suprasellar extension conceived during treatment with bromocriptine on 10 occasions resulting in eight full-term normal deliveries. Treatment was withheld shortly after conception in each pregnancy. RESULTS: Serum prolactin (PRL) levels fell initially from a mean of 2,776 (range 1,682 to 4,515) to 27 micrograms/L (range 1 to 71) with the development of a partially empty sella in all patients. Recovery of visual field defects occurred in the only affected individual. In case 1, PRL levels remained within the normal range, after bromocriptine withdrawal in the first pregnancy, with the development of an empty sella. Prolactin levels, however, increased substantially in cases 2 to 4. An asymptomatic suprasellar tumor extension returned in cases 2 and 3. After two or more pregnancies (cases 1, 3, and 4), there was a progressive decline in the serum PRL levels. Although still elevated in cases 3 and 4, the PRL levels were considerably below those obtained at presentation or in the first pregnancy. Tumor regression with the development of an empty sella was observed in both these patients as well in their pregnancy or postpartum period. CONCLUSIONS: Bromocriptine may be safely withdrawn during pregnancy in patients presenting with a macroprolactinoma. With multiple bromocriptine induced pregnancies, PRL levels and tumor size may progressively decrease with the eventual development of an empty sella.

Adult↗
PubMed1992

Volume-dependent intracavernous hemodilution during pharmacologically induced penile erections.

The change in the cavernous hematocrit following induction of pharmacological erection by an intracavernous injection of papaverine hydrochloride was documented in normal controls and patients with impotence. Blood samples taken from the penile cavernosa showed a significantly lower hematocrit compared to the systemic venous blood in all normal subjects. The decrease in the cavernous hematocrit was attributable to dilution of the cavernous blood pool by the injected volume of the drug, since this was not observed in erections produced by visual sexual stimulation. It appears that a restriction of the cavernous venous outflow in response to papaverine injection causes sequestration of the diluted blood in the cavernous compartment. The degree of cavernous hemodilution was found to aid in the differential diagnosis and was especially valuable in differentiating patients with arteriogenic impotence from those with venous leakage.

Adult↗
PubMed1992

Systemic manifestations of invasive amebiasis.

Eighty-four patients with serious infection due to Entamoeba histolytica were evaluated for systemic complications by objective criteria for dysfunction of the organ systems normally assessed in surgical sepsis. Of 71 patients with amebic liver abscess (ALA), 41% had systemic complications and 13% had more than one organ system involved. Patients > or = 40 years of age and those being treated with steroids were at significantly increased risk of developing complications (P < or = .05). The erythrocyte sedimentation rate and the levels of the acute-phase markers C-reactive protein (CRP) and serum amyloid A (SAA) were significantly elevated in patients with ALA over values in those without ALA (P < or = .05). ALA patients with complications had lower CRP and SAA concentrations than those without complications (P < or = .05). Blood and liver aspirates in ALA patients were usually bacteriologically sterile. The pathogenesis of systemic complications and the associated acute-phase response requires further study, and ways of predicting disease severity and intervening therapeutically must be devised.

Adolescent↗
PubMed1992

Hodgkin's disease in children.

This study provides information about histological types of Hodgkin's disease (HD) among children of Pakistan. Hodgkins disease constitutes 12 per cent of all pediatric malignant tumours. The peak incidence is between 6 and 10 years. The male to female ratio is 5.25:1. The majority (78 per cent) present with cervical lymphadenopathy. Mixed cellularity (MC) is the commonest histological type. In the developed countries nodular sclerosis (NS) and lymphocyte predominant (LP) subtypes are more common, and which have better prognosis. The developing countries have a higher incidence of poor prognostic subtypes. Our study indicates a situation intermediate between the two.

Child↗
PubMed1992

The effect of intracavernosal haemodilution on the radionuclide quantification of penile vascular changes during pharmacologically induced penile erections.

Radionuclide phallography was performed using 99Tcm-labelled red blood cells in conjunction with pharmacologically induced penile erections. The radioactivity content of aliquots of systemic venous blood taken from the antecubital vein was compared with aliquots of blood withdrawn from the penile cavernosa 20 min after an intracavernosal injection of 10 micrograms prostaglandin E1. The cavernosal samples showed significantly lower counts per unit of blood compared to the systemic venous blood indicating a comparatively lower concentration of tagged red blood cells. On haematological analysis, a significant difference in the haematocrit of the two samples was also established. The fall in the cavernosal haematocrit was found to result from dilution of the cavernosal blood pool by the injected volume of the drug since larger volumes of injection produced a greater fall in the haematocrit. Restriction of the cavernosal venous outflow in response to the injection of the vasoactive drug causes sequestration of the diluted blood in the cavernosal compartment. This factor might affect the quantification of penile blood volume using radiotracer methods.

Adult↗
PubMed1992

Gastric carcinoma--a study of 100 cases in northern Pakistan.

We describe 100 consecutive patients with histologically proven gastric carcinoma who were admitted to various hospitals in Northern Pakistan. Twenty-six per cent of patients were under 40 years of age. In a majority of patients the tumour was of a morphological type associated with poor prognosis. In most cases the disease was already at an advanced stage at the time of diagnosis, and most patients died within one year.

Adenocarcinoma↗
PubMed1992

Management of uric acid stone.

Uric acid stones are the most readily dissolvable of all types of urinary stones. By maintaining urinary pH between 6.2-6.8 with the use of sodium acid citrate or uralyt-U and reducing serum uric acid by allopurinol, we tried to dissolve 107 stones in 67 patients. Ninety three (86.9%) stones were dissolved and 6 (5.6%) passed spontaneously within a period of one year. Eight (7.5%) stones were removed surgically or with ESWL. Five (7.5%) patients had stone recurrence over a period of 3 years follow-up. Serum uric acid was raised in 19 (28.5%) and urinary uric acid in 12 (18%) patients while urinary pH was low in 46 (69%) patients. For uncomplicated uric acid stones oral chemolysis on an out-patient basis is the treatment of choice. It is simple, safe and inexpensive. However, it requires rigid compliance by the patient and strict follow-up by ultrasonography (JPMA 42: 153, 1992).

Adolescent↗
PubMed1992

Implementation of surgical audit in Pakistan.

UNLABELLED: Surgical audit, while extensively practised in the West, is still widely believed an impossible attainment in developing countries owing to the high cost and technology required to implement it. It is thus a poorly understood and rarely practised exercise in these countries. In this article we attempt to demonstrate the usefulness and feasibility of implementing audit in the setting of a developing country using personal computers (PCs) with simple, inexpensive and easily available software. We discuss the results of data analysis of 18 months of audit conducted by one general surgery team (2 consultants, 4 residents) at the Aga Khan University Hospital, Karachi. OBJECTIVE: To implement surgical audit in the setting of a developing country using microcomputers with simple, inexpensive and easily available software. DESIGN: Data analysis of inpatient audit proformas filled at weekly audit meetings from January 1989-July 1990 using Dbase III Plus. SETTING: One general surgery team (2 consultants, 4 residents) in a tertiary care hospital in Karachi. MAIN OUTCOME MEASURES: Disease patterns, caseload, complication rates. RESULTS: Conditions related to the biliary system made 26.1 per cent of the admitting diagnoses; 25.3 per cent of the patients had some co-existing medical condition as well, diabetes and hypertension being most common. The overall morbidity was 12.3 per cent and the mortality 1.5 per cent. Chest infection, wound infection and urinary retention were the most common post-operative complications. CONCLUSIONS: Results of audit data analysis initiated new research projects and development of protocols to improve patient care. Audit meetings also served as teaching sessions for residents.

General Surgery↗
PubMed1991

Ventilatory response to hypoxia in elderly humans.

In young adults the ventilatory response to 25 min of isocapnic hypoxia (SaO2 = 80%) is characterized by an initial increase in ventilation followed by a decline. The increase and decline are proportional. Because older adults have been reported to have reduced initial ventilatory responses to hypoxia, we compared responses to hypoxia in 14 older (mean age 62) and 15 younger (mean age 29) subjects. There was no difference. Both groups demonstrated a similar initial increase in ventilation with hypoxia and a similar subsequent decline due to a decline in tidal volume. In both groups the size of the initial increase was proportional to the subsequent decline. In both groups hyperoxia immediately after 25 min of hypoxia transiently depressed ventilation, while hyperoxia after room air breathing did not. We conclude that the ventilatory response to 25 min of hypoxia is independent of age in normal humans.

Adolescent↗
PubMed1991

Isolation of nephrocalcin from kidney tissue of nine vertebrate species.

Nephrocalcin (NC), a urinary calcium oxalate monohydrate (COM) crystal growth inhibitor, was purified from kidneys of nine vertebrate species including humans. All isolates were glycoproteins with high contents of aspartic and glutamic acids and small amounts of basic and aromatic amino acids. Carbohydrate contents ranged from 4 to 16 wt% among the different species, but all contained fucose, mannose, galactose, glucose, galactosamine, glucosamine, and N-acetylneuraminic acid. Although amino acid and carbohydrate compositions were similar, dissociation constants derived from calcium oxalate monohydrate inhibition varied between 10(-7) and 10(-8) M, and highest affinity could be related to highest ability of the kidney of origin to concentrate urine. Using an antibody raised against NC from human kidney tissue culture medium, we found strong immunoreactivity with two species, pigs and sheep. Thus far all vertebrate kidneys possess COM growth-inhibiting material that seems to be of glycoprotein character, and all the glycoproteins isolated so far share similar features, suggesting NC-like proteins are a well-conserved trait.

Amino Acids↗