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Biomedical subjects

A M Youssef

Publications and source records attributed to A M Youssef.

At least 19 recordsLinked to original sources
PubMed2001

Fate of postharvest-applied dichlorvos in stored and processed dates.

The fate of dichlorvos (DDVP) on dates after storage and processing of postharvest-treated fruits has been investigated. Residues were determined using GC-ECD after extraction of the fruits. A postharvest application was made to fruits at different stages of maturity: khalal fruits (mature full colored stage), rutab fruits (soft brown stage), and the mature tamer fruits (hard raisin-like stage). The fate of the residues was followed during the storage at refrigerated, room, and summer average temperatures (3, 22, and 43 degrees C). The amount of residues absorbed varied with the level of maturity. The rate of the loss of the residues was found to follow first-order kinetics. First-order rate constants were calculated for the different levels of maturity. The rate of the loss of DDVP increased as the temperature of storage increased. Also, it decreased with increasing maturation of the dates, which was characterized by a decrease in moisture content as well as water activity and an increase in sugar content. The period of storage study was limited by the time of maturation to the next stage. Most common home-cooking methods, including dehydration, jam-making, and syrup-making, resulted in significant decreases in residue levels. Only 0-13% of initial DDVP residues was detected in final products.

Chromatography, Gas↗
PubMed2001

Automated polyp detection at CT colonography: feasibility assessment in a human population.

PURPOSE: To test the feasibility of and improve a computer algorithm to automatically detect colonic polyps in real human computed tomographic (CT) colonographic data sets. MATERIALS AND METHODS: Twenty patients with known polyps underwent CT colonography in the supine position. CT colonographic data were processed by using a shape-based algorithm that depicts masses that protrude into the lumen. We studied nine shape criteria and three isosurface threshold settings. Results were compared with those of conventional colonoscopy performed the same day. RESULTS: There were 50 polyps (28 were > or =10 mm in size; 12, 5-9 mm; 10, <5 mm). The sensitivity with optimal settings for detecting polyps 10 mm or greater was 64% (18 of 28). Sensitivity improved to 71% (10 of 14) for polyps 10 mm or greater in well-distended colonic segments. Performance decreased for polyps less than 10 mm, poorly distended colonic segments, and other shape algorithms. There was a mean of six false-positive lesion sites per colon. These sites were reduced 39% to 3.5 per colon by sampling CT attenuation at the lesion site and discarding sites having attenuation less than a threshold. CONCLUSION: Automated detection of colonic polyps, especially clinically important large polyps, is feasible. Colonic distention is an important determinant of sensitivity. Further increases in sensitivity may be achieved by adding prone CT colonography.

Adult↗
PubMed1999

Fuzzy logic algorithm for quantitative tissue characterization of diffuse liver diseases from ultrasound images.

Computerized ultrasound tissue characterization has become an objective means for diagnosis of liver diseases. It is difficult to differentiate diffuse liver diseases, namely cirrhotic and fatty liver by visual inspection from the ultrasound images. The visual criteria for differentiating diffused diseases are rather confusing and highly dependent upon the sonographer's experience. This often causes a bias effects in the diagnostic procedure and limits its objectivity and reproducibility. Computerized tissue characterization to assist quantitatively the sonographer for the accurate differentiation and to minimize the degree of risk is thus justified. Fuzzy logic has emerged as one of the most active area in classification. In this paper, we present an approach that employs Fuzzy reasoning techniques to automatically differentiate diffuse liver diseases using numerical quantitative features measured from the ultrasound images. Fuzzy rules were generated from over 140 cases consisting of normal, fatty, and cirrhotic livers. The input to the fuzzy system is an eight dimensional vector of feature values: the mean gray level (MGL), the percentile 10%, the contrast (CON), the angular second moment (ASM), the entropy (ENT), the correlation (COR), the attenuation (ATTEN) and the speckle separation. The output of the fuzzy system is one of the three categories: cirrhosis, fatty or normal. The steps done for differentiating the pathologies are data acquisition and feature extraction, dividing the input spaces of the measured quantitative data into fuzzy sets. Based on the expert knowledge, the fuzzy rules are generated and applied using the fuzzy inference procedures to determine the pathology. Different membership functions are developed for the input spaces. This approach has resulted in very good sensitivities and specificity for classifying diffused liver pathologies. This classification technique can be used in the diagnostic process, together with the history information, laboratory, clinical and pathological examinations.

Algorithms↗
PubMed1993

Iatrogenic urogenital fistulae.

Nineteen patients with iatrogenic urogenital fistulae were treated between 1985 and 1989. All resulted from obstetric and gynaecological surgery. Major symptoms were leakage of urine through the vagina, menouria and perineal dermatitis. The fistulae formed after treatment for benign conditions in 18 patients. Fistulae complicating cancer surgery were uncommon. All patients with uretero-vaginal fistulae underwent preliminary percutaneous nephrostomy. Twelve patients underwent reconstruction using either the Boari-Ockerblad flap (5), uretero-neocystostomy (4) or other techniques (3), all with excellent results. Most of the remaining patients had treatment elsewhere. We consider that preliminary diversion, followed by delayed reconstruction, is a valuable option in the management of uretero-vaginal fistulae.

Adult↗
PubMed1990

Edible products from pelagic bissaria (Atherina mochon) fish.

The study was concerned with the utilization of small pelagic bissaria (Atherina mochon) fish in preparing edible, cheap, acceptable and nutritive products. The results confirmed the successful use of the mince of both the whole and beheaded gutted fish either alone or after mixing with different levels of plant sources (e.g. rice, wheat, potato, sesame butter, spices) in producing fresh fish ball, fish flour and spiced salted fish paste. Generally, the panelists preferred the products made from beheaded gutted fish mince above that prepared from whole one. The utilization of plant sources improved the technological properties of the products. The influence of processing on the chemical composition of these products was studied and tabulated.

Animals↗
PubMed1985

Blood pressure responses to care procedures in ventilated preterm infants.

Responses of mean aortic blood pressure to sequences of routine care procedures in 22 ventilated, preterm infants were studied daily for the first 3 days of life. In the first 11 infants standard care procedures were used, whereas the next 11 infants were preoxygenated by a preceding 10% increase in inspired oxygen concentration; in these infants, chest physiotherapy was entirely omitted while the frequency of endotracheal suctioning was reduced. A total of 259 blood pressure responses were recorded. In general, responses were biphasic, consisting of an initial blood pressure drop followed by a greater blood pressure rise of longer duration. Baseline blood pressure, as well as the minimum and maximum blood pressure during the care procedures, increased with gestational age and with postnatal age. The blood pressure drop was most pronounced in the infants requiring the most intensive ventilatory support and was reduced by modifying the care procedures. The blood pressure rise was the least in the infants receiving pancuronium and phenobarbitone. Eight infants, 4 in each group, had intraventricular haemorrhage; in these infants, the care procedures induced more pronounced blood pressure drops in the first day of life when compared to the infants without haemorrhage.

Blood Pressure↗
PubMed1982

The characterization of lipoprotein lipase isolated from the post-heparin plasma of the rainbow trout, Salmo gairdneri Richardson.

1. Intravenous injection of heparin into the trout resulted in the appearance in the plasma of a lipase with the properties of lipoprotein lipase. 2. The enzyme was purified to apparent electrophoretic homogeneity by means of heparin-Sepharose affinity chromatography. The enzyme was eluted with 1.5 M-NaCl and had a specific activity approx. 450-fold that of the post-heparin plasma. 3. The activity of the purified enzyme was inhibited by 1.0 M-NaCl and protamine sulphate and was stimulated between 3- and 8.8-fold by the addition of trout plasma. 4. The activity was strongly stimulated by trout very low density lipoproteins and to a lesser extent by high density lipoproteins. 5. The isolated enzyme fraction gave a single band on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and had an apparent subunit M4 of 63 000. 6. These results suggest that the uptake of lipid by the tissues in the trout can occur by a process similar to that in mammals.

Animals↗
PubMed1982

Effects of certain antibilharzial and contraceptive drugs on liver functions in rats.

Effects of single and combined administration of contraceptive drug (microvlar-30) and anti-urinary bilharzial drug (metriphonate) as well as anti-intestinal bilharzial drug (oxamniquine) on the liver functions of female albino rats were studied. Metriphonate increased serum globulin content and caused no change in the hepatic cells. Oxamniquine significantly increased the activities of serum transaminases and alkaline phosphatase and caused necrosis in some liver cells. Microvlar-30 exhibited no change on the serum enzymes, while marked increase was found in serum triglyceride and protein levels. The combined administration of metriphonate or oxamniquine with microvlar-30 prevented the increase in the levels of serum triglycerides and proteins. Histopathological examination confirmed the results obtained by chemical analysis.

Alanine Transaminase↗
PubMed1982

The surgical management of bilharzial strictures of the ureter.

Twenty-one ureteric strictures due to bilharzia have been treated surgically in 13 patients. Two required nephrectomy; 19 had direct ureteric reimplantation into the dome of the bladder after excision of the strictured segment of ureter. A simple technique of reimplantation into the dome of the bladder is described and early results have justified its further use.

Constriction, Pathologic↗
PubMed1980

Internal urethrotomy using Sachse knife for managing urethral strictures.

Urethral strictures secondary to trauma have been a frequent cause of obstruction in the male population residing in Saudi Arabia. This study of 59 patients presenting with urethral strictures covers a two-year period. Patients were asked to return for the initial follow-up one month after treatment and were asked about the force of their urine stream. They returned again after six months for a urethrogram; finally yearly follow-ups were commenced.

Follow-Up Studies↗
PubMed1980

Intrarenal and in situ kidney workbench surgery under hypothermia.

Two methods are described to cool the kidney. The surgact type of device can cover the entire kidney or a single pole. The second method for cooling the kidney is use of an intracellular hypothermic solution with methylprednisolone; the kidney is flushed via the renal artery to achieve cooling. Two interesting cases are presented which illustrate the methods used to achieve hypothermia.

Adenocarcinoma↗
PubMed1978

The use of pedicled grafts of omentum in the repair of transplant-related urinary tract problems.

Urologic complications related to renal transplantation may be difficult to treat and can be serious threats to life or to function of the transplanted kidney. Successful experience with omentrum for non-transplant and transplant-related reconstructive procedures recommends its further use. Herein are reported 4 patients in whom pedicled flaps of omentum were used to treat transplant-related urologic problems.

Adhesiveness↗