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Biomedical subjects

S Youssef

Publications and source records attributed to S Youssef.

At least 55 records · Page 3Linked to original sources
PubMed1992

Antiplatelet activity of the long-acting thromboxane receptor antagonist BMS 180,291 in monkeys.

The effects of the novel TxA2/prostaglandin endoperoxide (TP) receptor antagonist BMS 180,291 on platelet reactivity was determined ex vivo in conscious African green monkeys. Platelet aggregation responses to U-46,619 were decreased 50% and 100% at 23 to 24 hrs after BMS 180,291 oral doses of 1 and 3 mg/kg, respectively. In addition to inhibiting aggregation, a 3 mg/kg oral dose of BMS 180,291 also produced an 11 +/- 3-fold shift to the right in the U-46,619 concentration-response relationship for platelet shape change at 24 hrs after dosing. When the 3 mg/kg oral dose was continued for 11 days, the shift in this concentration-response relationship increased to 26 +/- 10- and 93 +/- 30-fold at 24 hrs after the 8th and 11th doses, respectively. This progressive inhibition corresponds to 93 +/- 3 and 99 +/- 1% blockade of platelet TP-receptors responsible for shape change, respectively. Comparable levels of TP-receptor blockade have been previously correlated with antithrombotic and antiischemic activities of TP-receptor antagonists in vivo. Platelet reactivity to U-46,619 had completely recovered on the 7th day after the final dose of BMS 180,291, indicating effective elimination from the circulation over this interval. In separate experiments, a 3-mg/kg i.v. dose of BMS 180,291 produced only marginal and transient hemodynamic effects in anesthetized African green monkeys. Overall, these data demonstrate that BMS 180,291 given orally once a day produces a sustained and therapeutically-relevant level of TP-receptor antagonism.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1992

Serum lipoprotein profile under different antihypertensive therapy.

Serum lipids of 80 patients with moderately severe essential hypertension under four different antihypertensive therapies were compared to ten matched hypertensives on a placebo, after eight weeks of therapy. The results in the serum lipid parameters measured after therapy showed with enalapril a significant increase in high-density lipoprotein cholesterol (HDL-C) and a decrease in the total cholesterol/HDL-C ratio. With benazepril a significant decrease in the total cholesterol/HDL-C ratio was obtained. With the diuretic combination Epitens the effect on serum sodium and potassium was minimal. No significant changes were found in the lipoprotein profile following the administration of the placebo. Both angiotensin converting enzyme inhibitors (enalapril and benazapril) induced a significant improvement in the atherogenic ratio; as well as the calcium antagonist (isradipine), though to a less extent. The diuretic Epitens induced an insignificant deterioration of the atherogenic ratio.

Adult↗
PubMed1991

Surgical indications in antenatally diagnosed ovarian cysts.

The antenatal diagnosis of ovarian cysts poses a therapeutic dilemma because the natural history of these lesions is not well known. A retrospective review from 1980 to 1989 showed 29 ovarian cysts in 27 patients diagnosed by prenatal ultrasonography performed between 28 and 36 weeks of gestation. Nineteen cysts were initially observed. Eleven cysts resolved (diameter less than 2 cm), three are decreasing, three were lost to follow-up, and two underwent resection. Eight patients underwent surgical exploration immediately following birth. The diagnosis of benign ovarian cyst was confirmed histologically in all cases. A review of the literature showed an additional 230 cases of antenatally diagnosed ovarian cysts. Simple cysts of the ovary tend to resolve spontaneously and, therefore, may be treated conservatively. Serial ultrasonography allows accurate diagnosis and long-term assessment of ovarian cysts in the neonate and may prevent unnecessary oophorectomy. Patients with cysts larger than 4 cm may be candidates for percutaneous aspiration, or should undergo removal of the cyst because of a significant risk of torsion. Complex cystic masses, symptomatic ovarian cysts, and cysts that do not resolve should be removed.

Female↗
PubMed1991

Distal congenital esophageal stenosis associated with esophageal atresia.

A series of six patients with congenital esophageal stenosis associated with esophageal atresia (EA) and distal tracheoesophageal fistula is presented. Three patients required only repeated dilatations, and have had good results. Two patients required limited resections of the distal esophagus, with excellent results. One patient died following a Heller myotomy. Tracheobronchial rests were present in the distal esophagus in the latter three patients. Diagnosis of congenital distal esophageal stenosis following repair of EA requires a high index of suspicion and a careful review of previous esophagrams. It is important to exclude anastomotic stricture and stenosis associated with gastroesophageal reflux. This requires barium esophagram, esophagoscopy with biopsy, and esophageal pH monitoring. Once a congenital basis for distal esophageal stenosis is suspected, management consists of dilatation by bouginage followed by balloon dilatation. Resection is reserved for persistent stenoses from tracheobronchial rests, which usually do not respond to dilatations.

Biopsy↗
PubMed1990

Appendicitis in children: current therapeutic recommendations.

Wound infection is the most common source of morbidity in appendicitis. Most recent pediatric series use protocols of preoperative antibiotics with aerobic and anaerobic coverage, intraoperative lavage, no peritoneal or wound drains, and continuation of antibiotics postoperatively with complicated appendicitis. There still remains controversy concerning skin closure and the duration of antibiotic therapy. We report the results of a prospective protocol followed over 2 years with 420 children. The protocol was designed to determine whether the skin could be closed primarily in all patients undergoing appendectomy. Preoperatively all patients received triple antibiotics (ampicillin, gentamicin, and clindamycin) that were continued postoperatively for two doses if there was a normal appendix or simple acute appendicitis, for at least 3 days with gangrenous appendicitis, and at least 5 days with perforated appendicitis. Antibiotics were continued if the patient remained febrile or had a white count greater than 10,000. No drains were used and the skin was closed primarily. The overall infectious complication rate was 1.0% (4/420). Among those with a normal appendix or simple acute appendicitis there were no infectious complications. Among those with gangrenous or perforated appendicitis there were 1.7% wound infections (2/117) and 1.7% intraabdominal abscesses (2/117). Duration of hospitalization was 2.1 days (range, 1 to 5 days) after simple acute appendicitis and 6.9 days (range, 3 to 40 days) after gangrenous or perforated appendicitis. These results set new standards in terms of wound management, infectious complications, and length of hospital stay.

Adolescent↗
PubMed1990

Malignant thymoma in children: a 20-year review.

Malignant thymomas are extremely rare in children, with only 27 cases reported thus far in the pediatric surgical literature. We report four additional cases diagnosed at this institution over the past 20 years (ages 3 to 14 years). Clinical presentations included superior vena cava syndrome, cough, dyspnea, cyanosis, enlarging mediastinal mass, spontaneous pneumothorax, and pleuropericardial effusion. Three patients underwent incomplete resection of the mass or biopsy because of "unresectability" and were treated with radiotherapy and adjunctive chemotherapy. One patient underwent near complete macroscopic resection as well as radiotherapy and chemotherapy. All patients died at intervals ranging from 6 months to 2 1/2 years after diagnosis. Three patients were found to have metastatic disease prior to death or at autopsy. In one case, the initial pathological diagnosis was lymphocytic thymoma. After ultrastructural studies were performed, the diagnosis was changed to thymic T-cell lymphoma. This patient subsequently developed acute lymphoblastic leukemia 3 months after surgical resection followed by radiotherapy. Malignant thymomas are highly aggressive tumors in children. A radical surgical approach with complete excision of the tumor and contiguous structures in continuity, with adjunctive radiotherapy and chemotherapy remains the only hope for survival in children with these rare lesions.

Adolescent↗
PubMed1990

Delayed presentation of Hirschsprung's disease: acute obstruction secondary to megacolon with transverse colonic volvulus.

Despite advances in the diagnosis of Hirschsprung's disease, occasionally there is still a delay in presentation. We report an unrecognized case of Hirschsprung's disease in a patient who presented at 11 years of age with volvulus of the transverse colon. This is the eighth reported case of colonic volvulus secondary to Hirschsprung's disease in children and the first occurring in the transverse colon. A literature review of other causes of colonic volvulus in children showed only 31 cases occurring in the sigmoid colon and nine in the transverse colon. The treatment of unsuspected colonic volvulus in children is discussed.

Acute Disease↗
PubMed1990

[Crohn's disease limited to the appendix. Apropos of a case].

A rare case of Crohn's disease limited to the appendix is reported in an 18 years old adolescent, hospitalised as having acute appendicitis. Appendectomy was performed. There were no postoperative complication and no recurrence after 3 years follow-up. Surgical indications are discussed and literature reviewed.

Abscess↗
PubMed1989

Splenic cysts: aspiration, sclerosis, or resection.

Percutaneous aspiration and tetracycline sclerosis is a safe but temporary therapy of large splenic cysts in children. Between 1985 and 1987, three girls with splenic cysts were seen. Their ages ranged from 5 to 14 years, and the cysts were from 8 to 16 cm in diameter. Despite their large size, all were asymptomatic and were discovered upon physical examination or ultrasound for unrelated conditions. All cysts were avascular by scan and had irregular crenated or smooth walls by ultrasound. Further investigation excluded infectious or parasitic causes. Each cyst was aspirated for diagnosis, and a pigtail catheter was inserted for drainage and sclerotherapy. All needle aspirations resulted in cyst collapse, but in one patient the pigtail catheter insertion was unsuccessful, and in the other two cases, multiple attempts of tetracycline sclerosis failed to obliterate the cysts. There were no other complications. Surgery for the recurrent splenic cysts was performed 3 months to 2 years following the percutaneous procedures. The two patients operated on with 3 months of aspiration underwent successful partial splenectomy and have normal splenic function by ultrasound scan, and absence of RBCs. The third patient had progression of the cystic disease throughout the spleen, and required splenectomy. Pathology confirmed multiseptate congenital mesothelial cysts in the first two patients and massive lymphangiomatosis in the third. In all three cases, percutaneous therapy was safe but did not result in long-term control. In one patient, the cystic disease progressed following sclerotherapy and may have influenced the need for complete splenectomy. Prior manipulation did not adversely affect the dissection and mobilization of the spleens.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Gastrointestinal manifestations of Sipple syndrome in children.

The diagnosis and management of patients with multiple endocrine neoplasia (MEN) type IIA and type IIB are of special challenge to pediatric surgeons. Patients characteristically present early in life with significant intestinal symptoms at a time when the characteristic phenotypic features of MEN IIB are frequently absent. We are reporting 12 patients with MEN type II (9 with type IIA and 3 type IIB or Sipple's syndrome), all of whom presented with gastrointestinal manifestations. All 12 patients had signs and symptoms of bowel obstruction during the neonatal period. An unusual association of Hirschsprung's disease and MEN IIA was noted in our nine patients found among a kindred of 92 individuals. All three patients with Sipple's syndrome (MEN IIB) had severe gastrointestinal symptoms since birth, including recurrent pseudoobstruction. The possibility of MEN type II should be considered in all cases of bowel obstruction in the newborn period. Screening for medullary carcinoma of the thyroid must be carried out from infancy. A detailed family history is very important to avoid unnecessary surgery for bowel obstruction in Sipple's syndrome.

Female↗
PubMed1986

Meconium ileus: is a stoma necessary?

During the 15 years from 1970 to 1984, 38 infants, all with cystic fibrosis, were treated for meconium ileus at The Montreal Children's Hospital and Ste-Justine Hospital for Children. Thirteen patients (34%) had complicated meconium ileus that included 7 perforations (2 colon, 5 ileum), 4 volvulus, and 2 atresia with meconium pseudocyst. In this group, various operations were done: resection with primary anastomosis for atresia, or resection with enterostomy for peritonitis or volvulus. One died shortly after surgery. Of 25 patients with uncomplicated meconium ileus (66%), one died shortly after arrival from respiratory distress, leaving 24 patients available for study. Gastrografin enema was attempted on 20 patients with eight successes (40%). Of the remaining 16 patients with unresolved meconium ileus, nine were treated with laparotomy and ileostomy, and one with laparotomy and T-tube irrigation. Six patients were treated by laparotomy and enterotomy for irrigation with N-acetylcysteine and evacuation by Fogarty catheter, a technique not widely used. No one succumbed in this group. This latter method of management is recommended for patients with simple uncomplicated meconium ileus.

Cystic Fibrosis↗