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Biomedical subjects

S A Sadek

Publications and source records attributed to S A Sadek.

At least 37 records · Page 2Linked to original sources
PubMed1994

An evaluation of vesical urodynamics before renal transplantation and its effect on renal allograft function and survival.

This prospective study investigated the urodynamics of the urinary bladder prior to renal transplantation in 57 patients and related this to graft function and transplantation outcome. The study demonstrated a clear deterioration in the pretransplant urodynamic characteristics in all subgroups, with male patients in the hemodialysis group (HD) showing a more substantial decline: 1st sensation volume (ml) in male HD patients = 112 (120) vs. 171 (173) in male CAPD patients, P < 0.05; and corresponding average flow rate for same groups 3 (3) ml/sec vs. 5 (5) ml/sec, P < 0.05. Figures are median (interquartile range). We have identified a subgroup of patients with a small bladder capacity (less than 100 ml) who have a reduced graft survival (55% vs. 92% for bladders larger than 100 ml at 2 years) apparently unrelated to immunological processes.

Adult↗
PubMed1994

Haemodynamics of liver reperfusion: comparison of two anaesthetic techniques.

Reperfusion during liver transplantation is associated with cardiovascular instability. We have compared the effects of two anaesthetic techniques on these changes. Twenty-six consecutive patients undergoing elective orthotopic liver transplantation were anaesthetized using either isoflurane or propofol. Haemodynamic profiles were studied before and at specific times after liver graft reperfusion. Systemic vascular resistance decreased at reperfusion in both groups (P < 0.0001), which was accompanied by increased cardiac output which attenuated changes in mean arterial pressure. In the isoflurane group, cardiac output was maintained primarily by improvement in stroke volume, whereas in the propofol group the increase in stroke volume was less marked and cardiac output was maintained by a greater heart rate. The cardiovascular changes were tolerated less well in those patients receiving propofol.

Adult↗
PubMed1994

Reperfusion injury, antioxidants and hemodynamics during orthotopic liver transplantation.

Endothelial injury occurs as a result of oxygen free radical production after ischemia and reperfusion of transplanted livers, causing hemodynamic disturbance. Patients with chronic liver disease generally have low levels of fat-soluble vitamins, which have important antioxidant roles. We therefore assessed circulating levels of the antioxidants vitamin A, vitamin E, beta-carotene and lycopene, indices of lipid peroxidation and hemodynamic changes during elective orthotopic liver transplantation in 12 patients. We found that initial antioxidant levels were severely depleted compared with healthy subjects, and in some patients carotene and lycopene levels were undetectable. Increased lipid peroxidation was also evident, as shown by thiobarbituric acid-reactive substances. On reperfusion of the liver graft, vitamin A and E levels fell (p < 0.01) and were associated with decreases in systemic vascular resistance (p < 0.02). These data show that patients undergoing liver transplant have lowered antioxidant defenses and evidence of free radical damage, which compound the additional insult of reperfusion injury. Antioxidant therapy in these patients before transplantation may ameliorate the effects of reperfusion.

Adult↗
PubMed1993

Alterations in plasma magnesium concentrations during liver transplantation.

Plasma magnesium concentrations were monitored during orthotopic liver transplantation. Magnesium supplementation was not given, although intraoperative calcium, potassium, and sodium bicarbonate were given as required. We found that there were significant falls in magnesium concentration to below our laboratory lower limit of normal, occurring chiefly during the anhepatic phase of surgery. Two patients with hypomagnesemia but normal potassium and calcium ion concentrations developed ventricular extrasystoles. Magnesium is a smooth muscle relaxant, dilating coronary arteries and peripheral vessels. It also exerts an antiarrhythmic effect and may have a permissive effect on the actions of catecholamines. Magnesium supplementation may be indicated during orthotopic liver transplantation because of the potentially beneficial effects and to avoid possible deleterious effects of hypomagnesemia. However, magnesium levels need to be monitored to avoid the unwanted side effects of hypermagnesemia.

Adenosine↗
PubMed1993

Does the Whitaker test add to antegrade pyelography in the investigation of collecting system dilatation in renal allografts?

Significant pelvicalyceal dilatation in renal allografts is currently investigated by antegrade pyelography. However, the clinical significance of a radiologically demonstrated narrowing of the ureter is unclear. Over a 21-month period 26 of 155 renal allografts with pelvicalyceal dilatation were investigated by antegrade pyelography. In eight allografts no ureteric stenosis could be identified. Two grafts were shown to have ureteric necrosis and required surgical intervention and 16 of the other grafts appeared to have a ureteric stenosis. 15 of the 16 allografts with radiological ureteric stenosis underwent a concurrent pressure flow study to assess the functional relevance of the ureteric narrowing. As shown by a pressure rise of > 7 mmHg at a perfusion rate of 10 ml min-1, 11 of the 15 grafts were functionally obstructed and were treated by a nephrostomy catheter followed by antegrade insertion of a ureteric stent. The four grafts with a negative pressure flow study were subsequently shown on biopsy to have rejection. The diagnosis of allograft rejection was also confirmed by biopsy in seven of the eight allografts without a radiological ureteric stenosis. The last of the eight allografts was found to be cyclosporin toxic. Pelvicalyceal dilatation of renal allografts is appropriately investigated by antegrade pyelography in combination with a pressure flow study which identifies those grafts with mechanical obstruction.

Adult↗
PubMed1993

Improving the evaluation of renal transplant collecting system dilatation by computerized ultrasound image digitization.

43% of the renal allografts transplanted at our centre demonstrate pelvicalyceal dilatation on ultrasonography. However, only 6% of grafts are ultimately shown to be obstructed by antegrade pyelography. We have attempted to improve the specificity of ultrasonography by a quantitative analysis of 394 serial ultrasound studies from 150 renal transplant recipients. Representative images in the longitudinal and transverse axes were selected by a single observer for each of the studies and the outline of the kidney and its pelvicalyceal system was traced out. The images were then digitized using a Summagraphics tablet so that the length, width and area of the kidney and its pelvicalyceal system were calculated for each image. A step-wise discriminant analysis was performed which showed that the ratio of the area of the kidney to its pelvicalyceal area in both axes discriminated between normal, dilated but non-obstructed, and obstructed grafts. The median ratio of kidney to collecting system area in the obstructed grafts was 5.2 in the longitudinal and 4.4 in the transverse scan planes (vs median ratios of 32.8 and 22.0 for non-dilated grafts). Using canonical discriminant function, an index was derived which combines these ratios for the longitudinal and transverse images of the same kidney and this has further improved the diagnostic accuracy (median index of 2.45 in obstructed group vs -0.85 in non-dilated kidneys). This method improves upon the radiologist's report and identifies those grafts which require intervention.

Adolescent↗
PubMed1988

Computerized ambulatory esophageal pH monitoring in 50 asymptomatic volunteer subjects. Results and clinical implications.

Fifty asymptomatic volunteer subjects underwent prolonged computerized ambulatory distal esophageal pH monitoring to characterize acid reflux patterns. A bimodal distribution of data, which corresponded to the erect and supine positions, occurred in 45 subjects, and separate mean baseline pH values were noted for the erect and supine positions (pH 6.46 and pH 5.46, respectively, p less than 0.001). At esophageal pH 4, reflux episodes occurred more commonly in the erect position (44 percent) than in the supine position (20 percent). There were also significantly greater numbers of reflux events and longer durations when the pH was below 3 (p less than 0.02) and 4 (p less than 0.001) in the erect compared with the supine position, but prolonged events (more than 10 minutes) occurred in both positions. Postprandial reflux occurred in 78.7 percent of the subjects, with an average of 5.1 episodes. A slight but significant correlation between age and erect reflux was seen (p less than 0.04). In the pH 3 to 5 range, 18 percent of the subjects had acid exposure in excess of the group mean plus 2 standard deviations and 10 percent in excess of the mean plus 3 standard deviations. Overall, a nonnormal distribution of pH data was found with 28 subjects having less than 1.6 percent of their values below pH 4. This finding may represent either the true spectrum of normal acid reflux or a subclinical pathologic state that will become symptomatic over time.

Adult↗
PubMed1988

24-hour ambulatory dual gastroduodenal pH monitoring. The role of acid in duodenal ulcer disease.

A new system for long-term, 24-hour, ambulatory dual gastroduodenal pH monitoring is described. Eighteen patients with active duodenal ulcers and ten healthy subjects were studied. Simultaneous gastric and duodenal bulb pH were measured during fasting, the ingestion of a solid meal, and for the remainder of the 24-hour period. The gastric pH profile was similar for both groups. There was no significant difference between the fasting duodenal bulb pH of the duodenal ulcer (DU) patients and controls. The daytime and nocturnal duodenal acid exposure was similar for both groups. The meal caused a similar pattern of duodenal acidification in both controls and DU patients, and acid neutralization appeared to be effective in DU patients. The role of acid in the duodenal bulb does not appear to be of primary pathophysiologic importance in duodenal ulcer disease.

Adult↗
PubMed1988

Pharmacological manipulation of adynamic ileus: controlled randomized double-blind study of ceruletide on intestinal motor activity after elective abdominal surgery.

In a double-blind placebo-controlled trial of patients undergoing elective abdominal surgery (n = 91), a single intravenous infusion of ceruletide (2.5 ng kg-1 min-1 for 1 hour) resulted in audible bowel sounds in 42/47 patients as opposed to 30/44 receiving placebo (P less than 0.025). Excessive bowel sounds were noted in 16 patients in the ceruletide group and four receiving placebo (P less than 0.01). Significantly more patients (P less than 0.01) in the ceruletide group (22/45 versus 9/44) passed flatus per rectum between the second and third post-operative day. Ceruletide infusion was accompanied by a significant increase in the incidence of nausea and vomiting (P less than 0.005, P less than 0.0025) but these side effects were short-lived. These results indicate that ceruletide is likely to be a useful therapeutic agent for acute intestinal adynamic motility disorders.

Abdomen↗
PubMed1988

Reflux oesophagitis and oesophageal transit: evidence for a primary oesophageal motor disorder.

Patients with reflux oesophagitis have a diminished capacity for distal oesophageal clearance. This is considered to be secondary to acid reflux damage to the oesophageal wall. We have postulated that the observed oesophageal dysmotility is a primary phenomenon. Using 24 hour oesophageal pH monitoring and the solid bolus oesophageal egg transit test, we evaluated the oesophageal transit of 55 patients, with symptomatic reflux oesophagitis, and 16 healthy volunteers. The transit for the entire oesophagus was significantly prolonged in the patient group. This delay was evident in all three segments of the oesophagus. Amongst the patients, there was significant correlation between the oesophageal transit time and the number of prolonged reflux events. No correlation was found, however, between symptom score or severity of endoscopic oesophagitis and transit time. These results would indicate that the oesophageal dysmotility is an integral part of gastrooesophageal reflux disease, and is more of a cause than an effect.

Adolescent↗
PubMed1987

The effect of alcohol on nocturnal gastroesophageal reflux.

The effect of 120 mL (4 oz) of scotch whiskey (40% alcohol) on nocturnal gastroesophageal reflux was studied by ambulatory esophageal pH monitoring. Seventeen healthy volunteers were studied on two occasions, using a computerized radiotelemetric esophageal pH monitoring system. The subjects were given the alcohol during the second session, three hours after the evening meal, and went to bed at their usual time. Seven of the 17 subjects had prolonged supine reflux episodes on the night of alcohol ingestion. These lasted an average of 47.1 minutes (23.2 to 91.8 minutes) and occurred on an average of 3 1/2 hours after ingestion of whiskey and 1.4 hours after lying down. None of the subjects had these episodes on the control night. There was also a significant acidic shift in the cumulative percentage of data points below a pH of 3 and a pH of 4 in the supine position on the night of alcohol ingestion compared with the control night. This study has shown that there was a significant exposure of the distal esophagus to acid and that the normal acid clearance of the esophagus in the supine position was impaired after only moderate amounts of alcohol.

Adult↗
PubMed1987

New physiological method of evaluating oesophageal transit.

A method of measurement of oesophageal transit time in the upright posture of a chewed solid bolus has been developed and assessed in normal volunteers (n = 16) and in 32 patients with oesophageal disease: organic stricture (n = 5), oesophageal motility disorders (n = 19) and reflux oesophagitis without stricture formation (n = 8). The test involves swallowing a 10 ml poached egg white bolus labelled with 99mTc sodium pertechnetate and external scanning by a gamma camera. An on-line computer program allows detailed analysis by the condensed image technique (which demonstrates the pattern of oesophageal transit) and activity-time curves for the whole, the upper, middle and lower thirds of the oesophagus. The reproducibility of the test is good (coefficient of variation of the total transit of 14 per cent). The results on the normal volunteers have shown that oesophageal transit slows in an aboral direction with transit being faster in the upper, when compared with the middle and lower thirds. The test clearly differentiates patients with oesophageal disease from the normal. The condensed image analysis appears to be useful in outlining the pattern of transit in patients with motility disorders. Patients with reflux oesophagitis have delayed oesophageal transit.

Adult↗
PubMed1987

Changes in cerebral perfusion after acute head injury: comparison of CT with Tc-99m HM-PAO SPECT.

Technetium-99m hexamethylpropyleneamine oxime (Tc-99m HM-PAO) was successfully used with single photon emission computed tomography (SPECT) on fourteen comatose patients who had acute head injuries. The SPECT scans were correlated with computed tomography (CT) scans obtained within 24 hours of the injury. Tc-99m HM-PAO SPECT was shown to have the following advantages: It reflected perfusion changes, was more sensitive than CT in demonstrating more lesions, and demonstrated lesions at an earlier stage than those demonstrated with CT. Different types of lesions, as evidenced by cerebral perfusion changes, have been described and categorized. The lesions that had a favorable prognosis could be separated from those with an unfavorable prognosis on the basis of the findings of Tc-99m HM-PAO SPECT.

Accidental Falls↗
PubMed1985

Carcinomatous changes in pharyngeal diverticula.

This paper presents a 10-year review of 70 patients treated for pharyngeal diverticula at Wythenshawe Hospital, Manchester. The presenting symptoms, diagnosis and the different methods used to treat them are discussed. The incidence of carcinomatous changes occurring in these pouches is noted and three such cases are documented.

Adult↗
PubMed1985

Plasmacytoma of the nasopharynx (a case report with a follow-up of twelve years).

A case of plasmacytoma of the nasopharynx with a 12-year follow-up is reported. The difficulty in clinical and histological diagnosis is stressed. Despite the development of multiple metastatic lesions, repeated investigations for multiple myeloma were consistently negative. The patient was treated with a combination of radiotherapy, surgery and chemotherapy at different stages of the disease.

Follow-Up Studies↗