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Biomedical subjects

H A Ahmed

Publications and source records attributed to H A Ahmed.

At least 19 recordsLinked to original sources
PubMed2003

Small joint fusion of the hand--a technique using Coughlin cup and cone reamers.

We describe a method of cup and cone arthrodesis using Coughlin concave and convex reamers, which we have used in a series of 22 hand joints in 19 patients. These reamers, originally designed for use in the foot, can be used in the hand to give very accurate preparation of bone surfaces. This results in maximum bone contact and the ability to fuse the joint in any desired position. The procedure is simple, rapid and forgiving. Union was achieved in all 22 cases, usually within 3 months.

Adult↗
PubMed2001

Thoracoscopic sympathectomy for treatment of hyperhidrosis surgical experience and results of 30 cases.

The thoracoscopic sympathectomy in treatment of primary palmar and axillary hyperhidrosis was performed on 30 patients complaining of hyperhidrosis admitted to El Demerdash University Hospital and Ain Shams University Specialised Hospital and The Saudi German Hospital between March 1999 and March 2001. The indication of surgery was primary palmar hyperhidrosis in 24 cases and combined palmar and axillary hyperhidrosis in 6 cases. 25 cases were males and 5 cases were females. The mean age in our sample was 25.7 +/- 4.05 years. There were no major complications in our series and 4 cases were complicated by intercostal vessels bleeding which were successfully controlled by cauterization during surgery and no one of them necessitated neither thoracotomy nor application of intercostal tubes. The patients were followed up for one year after operation and only one case had recurrence of palmar hyperhidrosis.

Adult↗
PubMed1999

Assessment of liver function by the MEGX test in patients with schistosomiasis and cirrhosis.

OBJECTIVES: The aim of this study was to determine the effect of schistosomiasis infection on hepatic function in Egyptian patients with posthepatitic cirrhosis. DESIGN AND METHODS: Hepatic function, was assessed in 66 Egyptian patients, with (n = 30) and without (n = 36) schistosomal liver fibrosis due to Schistosoma mansoni and in 20 healthy controls, using the monoethylglycinexylidide (MEGX) test. Serum MEGX concentrations were measured before and 5, 15, 30, 60, 120, and 180 min after a lidocaine bolus. The sero-prevalence of antibodies to hepatitis C was also determined in the patients. RESULTS: MEGX test results were significantly lower in patients than in controls at all time points. MEGX test results declined with advancing Child Class. Receiver operating characteristic (ROC) curve analysis revealed the following areas under the ROC curves for discrimination of Child Class C from Child Classes A/B: 30 min, 0.762; 60 min, 0.743; 120 min, 0.731; 15 min, 0.728; 180 min, 0.728; 5 min, 0.602. Schistosomiasis infection had no influence on MEGX test results when cirrhotic patients with (Schisto+) and without (Schisto-) schistosomiasis were compared. While the prevalence of the hepatitis B surface antigen was only 16.7% (Schisto-) and 26.7% (Schisto+), there was an extremely high sero-prevalence of antibodies to hepatitis C (HCV) in both groups: 88.9% (Schisto-) and 73.3% (Schisto+). CONCLUSIONS: The association of schistosomal liver fibrosis with cirrhosis does not additionally influence MEGX formation. In addition, HCV rather than schistosomiasis infection must be considered as a major cause for the progressive liver disease in these patients.

Adult↗
PubMed1999

Demonstration and partial characterisation of phospholipid methyltransferase activity in bile canalicular membrane from hamster liver.

BACKGROUND/AIMS: Methylation of phosphatidylethanolamine to phosphatidylcholine predominantly takes place in mitochondrial-associated membrane and the endoplasmic reticulum of the liver. The transport of the phospholipids from endoplasmic reticulum to the bile canalicular membrane is via vesicular and protein transporters. In the bile canalicular membrane a flippase enzyme helps to transport phosphatidylcholine specifically to the biliary leaflet. The phosphatidylcholine then enters the bile where it accounts for about 95% of the phospholipids. We postulated that the increased proportion of phosphatidylcholine in the bile canalicular membrane and the bile compared to the transport vesicles may be due to a methyltransferase activity in the bile canalicular membrane which, using s-adenosyl methionine as the substrate, converts phosphatidylethanolamine on the cytoplasmic leaflet to phosphatidylcholine, which is transported to the biliary leaflet. The aim of our study was to demonstrate and partially characterise methyltransferase activity in the bile canalicular membrane. METHODS: Organelles were obtained from hamster liver by homogenisation and separation by sucrose gradient ultracentrifugation. These, along with phosphatidylethanolamine, were incubated with radiolabelled s-adenosyl methionine. Phospholipids were separated by thin-layer chromatography and radioactivity was counted by scintigraphy. RESULTS: We demonstrated methyltransferase activity (nmol of SAMe converted/mg of protein/h at 37 degrees C) in the bile canalicular membrane of 0.442 (SEM 0.077, n=8), which is more than twice that found in the microsomes at 0.195 (SEM 0.013, n=8). The Km and pH optimum for the methyltransferase in the bile canalicular membrane and the microsomes were similar (Km 25 and 28 microM, respectively, pH 9.9 for both). The Vmax was different at 0.358 and 0.168 nmol of SAMe converted/mg of protein/h for the bile canalicular membrane and the microsomes, respectively. CONCLUSION: The presence of the methyltransferase activity in the bile canalicular membrane may be amenable to therapeutic manipulation.

Animals↗
PubMed1999

Prescribing habits in primary biliary cirrhosis: a national survey.

BACKGROUND: Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease of unknown aetiology. A number of drugs have been used in its treatment, but only ursodeoxycholic acid (UDCA) has been shown to improve survival. Our aims were to determine the current prescribing habits in PBC of all practising gastroenterologists in the UK. METHODS: A postal questionnaire was sent to 454 gastroenterologists in 1996, followed by a second questionnaire a month later to the non-responders. RESULTS: Of 454 doctors sent questionnaires, 379 (83%) replied. Of these, 58 were excluded from further analysis as they were not practising gastroenterologists. There are an estimated 4337 patients with PBC being seen by gastroenterologists in hospitals. Of these, only 1376 (32%) are being seen in liver units. Ninety-one per cent of gastroenterologists look after patients with PBC (median 10 patients, range 1-500). Ninety-five per cent of gastroenterologists prescribe UDCA but there is a large dose range (median 11.5 mg/kg/day, range 1.5-23.1). Of these, 93% also prescribe cholestyramine. Only 45 (14%) gastroenterologists prescribed other treatments for PBC (13 colchicine, 24 steroids, nine penicillamine, 13 immunosuppressants). Only 53 (17%) treat the symptoms/complications of PBC (37 fat-soluble vitamins, 15 calcium, six bisphosphonates, one hormone replacement therapy, 10 antihistamines, 10 rifampicin). CONCLUSIONS: UDCA is being prescribed for PBC by the majority of practising gastroenterologists but over a wide dose range. Very few gastroenterologists are using preventive treatment for osteoporosis in this high-risk group. Other treatments, as yet unproven in trials, are being prescribed by a minority of gastroenterologists.

Cholagogues and Choleretics↗
PubMed1999

Optimum dose of ursodeoxycholic acid in primary biliary cirrhosis.

BACKGROUND: Ursodeoxycholic acid (UDCA) improves liver function tests and prolongs survival in primary biliary cirrhosis (PBC). The dose of 10- 15 mg/kg/day used in the large trials has largely been based on that used for gallstone dissolution. The only dose-response study of UDCA in PBC suggested that a dose of 8 mg/kg/day was the most efficacious. However, disease stage of the patients was not known, higher doses of UDCA were not tried and there was no 'washout period' between the different doses. The aim of this study was to determine the optimum dose of UDCA in early-stage PBC (stage 1 and 2). METHODS: Twenty-four biopsy-proven early-stage PBC patients (one male, 23 female) received five doses of UDCA (0, 300, 600, 900, 1200 mg/day) each for 8 weeks with 4-week washout periods between doses. Symptoms (pruritus, fatigue, diarrhoea) were assessed on a four-point scale (none, mild, moderate, severe). Liver function tests (LFTs) were performed using conventional methods, and serum bile acids were measured using gas liquid chromatography. RESULTS: The dose of 900 mg/day produced the greatest enrichment of UDCA in serum bile acids; although there was no difference in the enrichment of UDCA between the different doses. There was a trend towards normalization of the abnormal LFTs in a dose-dependent manner (for y-glutamyl transferase (yGT), alkaline phosphatase (ALP), alanine transaminase (ALT) and IgM). Multi-factorial analysis showed that UDCA treatment, irrespective of dose, was significantly better than placebo for all the variables. The 900 and 1200 mg doses were better than both 300 and 600 mg using yGT and total bilirubin as variables, better than 300 mg using ALP and IgM as variables, and better than 600 mg using albumin as a variable. No variables showed a significant difference between 900 and 1200 mg. CONCLUSION: The optimum dose of UDCA is 900 mg/day (equivalent to 13.5 mg/kg/day).

Adult↗
PubMed1996

New insights into the pathogenesis of copper toxicosis in Wilson's disease: evidence for copper incorporation and defective canalicular transport of caeruloplasmin.

Previous studies have suggested that copper is incompletely incorporated into caeruloplasmin, the major plasma form of copper-transporting protein, in the genetic copper toxic condition, Wilson's disease. In this paper we have investigated the role of copper and caeruloplasmin in the abnormal biliary copper transport and characterizes Wilson's disease. Using SDS/PAGE and Western blotting, we have demonstrated the presence of holocaeruloplasmin in liver samples from patients with Wilson's disease (abnormal biliary copper excretion) and in control patients (normal biliary copper excretion). The presence of holocaeruloplasmin was also confirmed by measurement of caeruloplasmin oxidase activity using staining with o'Dianisidine. In contrast with the findings in liver tissue, holocaeruloplasmin was absent from bile from patients with Wilson's disease, but as expected it was present in the bile from control subjects. We have also identified and partially characterized a 189-200 kDa protein from purified human biliary canalicular membranes which binds copper and possesses caeruloplasmin-like activity when probed with a specific human anti-caeruloplasmin antibody. In conclusion, we have demonstrated that copper incorporation in caeruloplasmin is normal in patients with Wilson's disease contrary to previous reports. Secondly, we have shown that the defect in Wilson's disease appears to lie in the biliary canalicular excretion of holocaeruloplasmin resulting in its retention within the hepatocyte causing copper toxicosis. Finally we have identified and partially characterized a caeruloplasmin-binding protein from biliary canalicular membranes which may provide a link to the gene defect in Wilson's disease.

Apoproteins↗
PubMed1995

The effects of unsaturated fatty acids on Helicobacter pylori in vitro.

The effects of three unsaturated free fatty acids on Helicobacter pylori growth in vitro was determined. Growth of H. pylori in Brucella broth was inhibited in a dose-dependent manner by arachidonic, linoleic and oleic acids. The degree of inhibition at any one concentration was related to the degree of fatty acid unsaturation. Triolein, a triacylglycerol ester of oleic acid did not inhibit growth. Inhibition of H. pylori growth was associated with disruption of cell membranes. Incubation with 14C linoleic acid and 14C oleic acid showed incorporation of these fatty acids into H. pylori cell mass and phospholipids leading to alteration of the phospholipid composition of the organism. Incorporation was greater with linoleic than oleic acid and this was associated with a greater inhibition of growth. These findings indicate that H. pylori is sensitive to unsaturated free fatty acids through their incorporation into phospholipids and membrane destruction. This may have therapeutic implications.

Arachidonic Acids↗
PubMed1995

Intrahepatic biliary cholesterol and phospholipid transport in humans: effect of obesity and cholesterol cholelithiasis.

The mode of transport of biliary lipids within the hepatocyte and the role of the bile canalicular membrane (BCM) in biliary lipid secretion are not well understood. We hypothesized that biliary cholesterol and phospholipid are co-transported across the hepatocyte in vesicular form from the endoplasmic reticulum to the bile across the BCM. We obtained wedge liver biopsies and fasting gallbladder bile from 15 cholesterol gallstone patients and 10 control subjects. BCM, basolateral membrane (BLM), and many microsomal vesicular fractions were isolated by centrifugation. One of the vesicular fractions (V3) was enriched in both the microsomal and the BCM marker enzymes and had a high phosphatidylcholine proportion in its phospholipid with a fatty acid pattern similar to biliary phosphatidylcholine. Moreover, its cholesterol content was increased in the obese cholesterol gallstone subjects, who had an increase in cholesterol synthesis, as indicated by the increased activity of the HMG-CoA reductase. The cholesterol content correlated with HMG-CoA reductase activity. A direct correlation was found between cholesterol/phospholipid ratio in V3, BCM, and in bile but not in the BLM. These data are in agreement with the assumption that this vesicular fraction is involved in the transport of cholesterol and phospholipid from the endoplasmic reticulum to the site of secretion in the BCM, and thence to bile, and that this transport is enhanced in obese gallstone patients.

Bile Canaliculi↗
PubMed1994

Soluble intercellular adhesion molecule-1 in primary biliary cirrhosis: relationship with disease stage, immune activity and cholestasis.

Intercellular adhesion molecule-1, strongly expressed on the interlobular and proliferating bile ducts in primary biliary cirrhosis, is important in the migration and adhesion of inflammatory cells from the circulation to these structures. A soluble form has been found to be elevated in serum in primary biliary cirrhosis. Our aim was to check on the role of soluble intercellular adhesion molecule-1 in primary biliary cirrhosis with particular reference to its specificity by comparison with other disease control groups and to assess its relationship with stage of disease activity, circulating lymphocyte activation and cholestasis. Soluble intercellular adhesion molecule-1 (enzyme-linked immunosorbent assay) and liver biochemistry were measured in 41 patients with primary biliary cirrhosis, 9 with primary sclerosing cholangitis, 12 with alcoholic liver disease and 17 healthy controls. In subgroups of patients with primary biliary cirrhosis, lymphocyte activation and hepatic bile acid uptake and excretory rates were determined. Soluble intercellular adhesion molecule-1 was significantly higher in all three disease groups. Levels in primary biliary cirrhosis and primary sclerosing cholangitis were similar and significantly higher than alcoholic liver disease. Soluble intercellular adhesion molecule-1 expression was greater in late primary biliary cirrhosis than early disease and correlated with histological progression. Correlations were also found with alkaline phosphatase, gamma-glutamyl transpeptidase and conjugated bilirubin. A trend toward an inverse correlation with hepatic excretory rate was found, but no correlation was detected with circulating lymphocyte interleukin-2 receptor expression.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Hydrophobic/hydrophilic balance of proteins: a major determinant of cholesterol crystal formation in model bile.

Biliary proteins are speculated to play an important role in modulating nucleation of cholesterol crystals from supersaturated gallbladder bile, acting either as pro- or antinucleating agents. However, conflicting results have been obtained in attempts to isolate specifically active proteins. Our hypothesis, therefore, was that this may be a nonspecific effect of proteins, related to their secondary structure or to their overall hydrophobic/hydrophilic balance. We studied the effect of a number of "nonspecific" proteins with different secondary structures on cholesterol crystal formation in model bile. Their relative hydrophobic/hydrophilic indices were experimentally determined by measuring their retention time on a phenyl-agarose column (hydrophobic ligand). The potency of each protein in enhancing or inhibiting crystal formation was ranked according to the lowest protein concentration capable of significantly influencing crystal formation by comparison with control using model bile with cholesterol saturation index (SI) of 1.2 and 1.5. Some of these proteins (chymotrypsin, IgA, myoglobin) significantly enhanced crystal formation, while some (apolipoproteins A-I, A-II, and B) inhibited it, and others (IgG, chymotrypsinogen) showed no effect. The different effects were not related to their secondary structure but to their hydrophobic/hydrophilic index, with the most hydrophilic proteins showing maximal pronucleating potency and vice versa (r = 0.93; and 0.97, P < 0.005 for SI = 1.2 and 1.5, respectively). Pronucleating proteins enhanced, while antinucleating proteins inhibited, the transfer of cholesterol and phospholipid from micellar to vesicular forms. We conclude that the effect of proteins on cholesterol crystal formation in model bile is nonspecific and mainly related to their hydrophobic indices rather than to their secondary structures.

Bile↗
PubMed1993

Cholesterol nucleation time measurement in nasobiliary or nasoduodenal bile. Comparison with surgical bile.

The usual technique of collecting gallbladder bile at laparotomy is not suitable for sequential studies of cholesterol nucleation time (NT) in patients receiving therapy to prevent or dissolve cholesterol gallstones. Our aim was to study the feasibility of measuring NT in bile obtained by nasobiliary or nasoduodenal intubation. We studied a total of 10 cholesterol gallstone patients; in 8 bile was collected by nasobiliary drainage, in 7 it was collected by nasoduodenal intubation, and in 3 it was collected at laparotomy the next day. Three patients developed abdominal pain and increased serum amylase after endoscopic retrograde cannulation. All three biles obtained at operation nucleated quickly (NT, 1-4 days), whereas duodenal biles were all beyond the expected range (NT, > 21 days). Chymotrypsin activity, as a marker of pancreatic juice contamination, was detected in five of eight nasobiliary biles and in all seven duodenal biles but in none of the surgical biles. Free fatty acids (reflecting lipolysis) were significantly higher in duodenal than in surgical biles, with nasobiliary bile showing intermediate values. Nasobiliary bile showed either a rapid (median NT, 3 days) or a slow (median NT, 22 days) NT, depending on whether chymotrypsin activity was absent or present (p < 0.05). We conclude that duodenal bile is never suitable for NT determination because of contamination by pancreatic enzymes, and that nasobiliary bile, if not contaminated by pancreatic enzymes, may be suitable for NT determination but that its collection via a nasobiliary tube after cholecystokinin injection carries a risk of pancreatitis.

Adolescent↗