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Biomedical subjects

A J Ross

Publications and source records attributed to A J Ross.

At least 55 records · Page 3Linked to original sources
PubMed1993

Analysis of the monoclonal antibodies comprising WC6.

The WC6 antibovine monoclonal antibodies (mAbs) CC98, IL-A114 and IL-A53 were investigated for reactivity in sheep by (fluorescence activated cell sorting) FACS analysis, immunoprecipitation and immunohistology. The mAbs behave identically by all criteria although IL-A114 reacts more weakly than the other mAbs. This probably reflects limited cross-species reactivity. The mAbs stain < 30% of lymphocytes from blood, efferent and afferent lymph and the majority of afferent lymph dendritic cells. They also weakly stain granulocytes. They precipitate molecules of apparent molecular weight 220 kD and 180-190 kD. Sequential immunoprecipitation shows that CC98 antigen is not related to CD45. Immunohistology indicates staining of B cell areas and macrophages in Peyer's patch and lamina propria. The data show that these monoclonal antibodies react with a molecule distinct from OvCD45R.

Animals↗
PubMed1993

Diaphragmatic hernia in tetrasomy 12p mosaicism.

Twelve infants with diaphragmatic hernias plus other anomalies who had mosaicism for tetrasomy isochromosome 12p (Pallister-Killian syndrome) are reviewed. A newborn infant with a diaphragmatic hernia plus dysmorphic features and a normal peripheral blood karyotype should have chromosome analysis performed on fibroblasts or bone marrow.

Abnormalities, Multiple↗
PubMed1993

Mesenteric, omental, and retroperitoneal cysts in children: a clinical study of 22 cases.

Cystic lesions of the mesentery, omentum, and retroperitoneum are rare; from 1956 to 1990, 22 patients had operative treatment for such lesions at our institution. They ranged in age from 1 month to 14 years; 75% were younger than 5 years. All had either an acute abdomen or, more commonly, a silent abdominal mass. In all cases, the histologic diagnosis was lymphangioma. Abdominal ultrasonography was done in all cases after 1977 except for two patients who had an acute abdomen requiring emergency exploration. A cystic abdominal mass was diagnosed in 94% of these cases, but the correct diagnosis of lymphangioma was made prior to surgery in only 24%. Mesenteric cysts are most common in the small bowel mesentery. Omental cysts usually occur singly and are easily resected, but multiple cysts predominate in the mesentery and retroperitoneum. Complete resection was accomplished in 82% of our cases. Two patients required partial bowel resection, and four had partial excision with marsupialization of the cysts. With a mean follow-up of 23 months, we have had three recurrences, but none necessitated reexploration. Extra-abdominal lesions, mainly cutaneous lymphangiomas, developed in two cases. Prognosis is good after surgical excision, but long-term follow-up is advisable because of the possibility of recurrence, even during adulthood.

Adolescent↗
PubMed1993

Systemic and mesenteric vascular effects of platelet-activating factor and cocaine. In vivo effects on a neonatal swine model.

Mesenteric hypoperfusion may be responsible for alterations in gut mucosa leading to necrotizing enterocolitis. Platelet-activating factor (PAF) and cocaine have been implicated in the etiology of necrotizing enterocolitis. We have demonstrated direct toxic effects of these compounds in vitro, but the in vivo mechanism of bowel damage is unknown. Newborn piglets (3.0 +/- 0.3 kg) had physiologic parameters (electrocardiogram, blood pressure, pulse, and central venous pressure) continuously monitored as well as Doppler probe recordings of superior mesenteric artery flow (Qsma). Aortic flow with calculation of cardiac index, and systemic and mesenteric vascular resistances (SVR and MVR) were also determined. Group 1 (N = 8) received PAF (0.5 microgram/kg). Groups 2 (N = 8) and 3 (N = 8) received high (17 mg/kg) and low (9 mg/kg) doses of cocaine, respectively. Each subject served as its own control. Histology demonstrated edema or early mucosal hemorrhage in all groups. PAF caused a third-degree atrioventricular block of short duration and a prolonged decrease of the cardiac index, but only a brief elevation of SVR and MVR. The cocaine groups had a sustained increase of SVR and MVR associated with a decrease of cardiac index. The decrease of Qsma paralleled the changes of MVR in each subject. These data show that both PAF and cocaine induce mesenteric ischemia. The effect of PAF is of short duration and mainly related to its cardiotoxic effects resulting in low Qsma. Cocaine causes an increase in MVR with prolonged depression of mesenteric flow.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Sites of relapse in patients with neuroblastoma following bone marrow transplantation in relation to preparatory "debulking" treatments.

Forty-one patients with high-risk neuroblastoma were treated between September 1977 and December 1987 at the Children's Hospital of Philadelphia with supralethal chemotherapy and total-body irradiation rescued by bone marrow transplantation. Twenty-six patients were treated following relapse and 15 were newly diagnosed. At the time of evaluation, January 1991, 11 of 41 patients (26.8%) remained in complete remission. Actuarial survival rates of patients transplanted following relapse were 0.35 and 0.31 at 2 and 5 years, respectively, and actuarial disease-free survival rates were 0.38 at 12 months and 0.27 at 24 months. The 2- and 5-year actuarial survival values for the patients with newly diagnosed disease were 0.53 and 0.25, respectively, and the 12- and 24-month disease-free survival rates were 0.47 and 0.27, respectively. There was no significant difference in survival between these groups. Twenty-nine of the 41 patients reviewed were available for analysis of the effect of local treatment. Thirteen had a combination of surgery and radiation (RT), 2 had surgery alone, 9 had RT alone, and in 5 patients no local treatment was given. The local relapse rate was 17%; it was 15% following surgery plus RT and 22% following RT alone. The failure rate combining local and distant relapse is 62% for surgery plus RT and 44% for RT alone. Although a local relapse rate of 17% is imperfect, it is a relatively small contribution to the overall relapse of 62%.

Adrenal Gland Neoplasms↗
PubMed1991

Parathyroid surgery in children.

Parathyroid surgery in children is uncommon. Spontaneously occurring cases of hyperparathyroidism are almost always due to single-gland disease: however, on exploration all four parathyroid glands should be identified. Most of the other instances in which the surgeon needs to perform a parathyroidectomy on an infant or a child will be situations were multiple-gland disease is the rule rather than the exception. Therefore, the surgeon must have in his mind a well developed logical approach to the management of children with parathyroid disorders on the basis of multiple glandular disease. We believe that the technique of parathyroid autotransplantation very satisfactorily addresses the surgical needs of children with familial hyperparathyroid states, including the multiple endocrine neoplasias. We believe that it is mandatory treatment in patients presenting with neonatal primary hyperparathyroidism and is also the procedure of choice in children with secondary and tertiary hyperparathyroidism. The workup and diagnosis of parathyroid disorders should be familiar to the surgeon who undertakes neck exploration on children, and the entity of familial hypocalciuric hypercalcemia should be looked for, as these patients have a strong likelihood of not benefiting from parathyroidectomy.

Child↗
PubMed1991

Maternal cocaine abuse and necrotizing enterocolitis: outcome and survival.

Since 1987, multiple complications related to maternal cocaine abuse have been reported. Necrotizing enterocolitis-(NEC) of the newborn has been observed with increasing frequency. We report a comparative analysis of infants with NEC born to cocaine abusing mothers (n = 11) to a standard population of newborns with NEC (n = 50) treated in this institution from January 1987 to July 1989. We also evaluated whether prenatal cocaine abuse predisposes infants to NEC by performing a case-control analysis using 51 of 61 infants and controls matched for race, sex, and birthweight +/- 250g. Significant differences were apparent between the cocaine-affected infants (COC) and the noncocaine-affected infants (Non-COC) with regard to surgical intervention (72.7% v 38%, P less than .05), the presence of massive gangrene (54% v 12%, P less than .01), mortality (54.5% v 18%, P less than .01), and maternal age (28.13 +/- 3.82 years v 24.12 +/- 6.21 years P less than .05). No differences between these groups could be demonstrated for other known NEC risk factors such as gestational age, birthweight, feeding patterns, umbilical artery catheters, or asphyxia. In the matched case-control study, infants born to mothers who were cocaine abusers demonstrated a 2.5-fold increased risk of developing NEC (95% Cl = 1.17 to 5.32, P = .02) when compared with the noncocaine-exposed group. Maternal cocaine abuse appears to play a contributory role in the pathogenesis of NEC, its extent, and its outcome.

Adult↗
PubMed1991

Postoperative intussusception: increasing frequency or increasing awareness?

Postoperative intussusception in children is a rare but well recognized phenomenon. The diagnosis is often delayed due to the protean manifestations of the disorder (ileus, distention, and nausea and vomiting) which, when encountered shortly after an abdominal operation, usually result in a low index of suspicion because they are common after laparotomy. Experience with two cases of postoperative intussusception within 24 hours heightened our index of suspicion. Review of our records indicated we had diagnosed and treated postoperative intussusception in 14 children during the preceding 4 years. Patient ages ranged from 4 months to 12 years (mean 39 months, median 20 months), and symptoms appeared on postoperative days 3 to 36 (mean 10 days, median 6 days). Initial operations included excision of a retroperitoneal or abdominal tumor (five cases), Nissen fundoplication and gastrostomy (three), ileal resection (two), Ladd procedure (one), Duhamel operation (one), and operative reduction of ileocolic intussusception (the two most recent cases). Eleven patients had appendectomy (five by the inversion technique), and three had placement of a transgastric small bowel feeding tube. Nine children had had either barium enema or upper gastrointestinal studies because of the postoperative suspicion of obstruction; one patient had both. Diagnostic studies were not done in four patients. Operative reduction was successful in all but one child, who required bowel resection.

Child↗
PubMed1990

The role of leukocytes in mediating mucosal injury of intestinal ischemia/reperfusion.

The source of oxygen-free radicals in putative intestinal reperfusion injury is unknown. To define the role of the circulating leukocyte in this pathophysiology, we report a rat model of ex vivo intestinal perfusion that permits alteration of the intravascular perfusate. The validity of the model is proven by the degree of intestinal injury produced by reperfusion following occlusive ischemia. Severe damage was noted in the animals reperfused with normal blood; however, reperfusion with a white blood cell-free perfluorochemical significantly ameliorated this damage. The addition of leukocytes to the perfluorochemical negated the previously seen protection of the leukocyte-free perfusate. This study strongly suggests that the intravascular leukocyte is an important mediator of intestinal ischemia/reperfusion injury.

Animals↗
PubMed1990

A trilaminar skin coverage technique for treatment of severe degloving injuries of the extremities and torso.

A 60 percent degloving injury involving the torso and lower extremities of an 8-year-old boy is described. Successful management employed the use of a new trilaminar skin coverage technique. With the avulsed flap still attached to its bed, a 0.14-inch split-thickness graft of epithelium and superficial dermis is raised with a power-driven dermatome. From the same harvest site, one level deeper, a second layer consisting of split-thickness dermis (0.14 inch) is taken. Both the first and second layers are meshed and expanded. The remaining degloved flap is excised and, on a sterile bench, defatted to produce a third layer of deep dermis. In our case, this third layer was ultimately lost, but it functioned well as a temporary biologic dressing. Depending on donor-site morbidity, other potential applications of this method (i.e., major burn injuries) may be feasible.

Body Surface Area↗
PubMed1989

Partial splenectomy: the preferred alternative for the treatment of splenic cysts.

We report six pediatric patients who had a partial splenectomy for splenic cysts and a seventh patient who had a total splenectomy. There were six epidermoid cysts and one traumatic cyst. All patients had benign postoperative courses. All patients who underwent partial splenectomy had a significant postoperative rise in platelet count that subsequently returned toward baseline. This rise implies a loss of splenic function, although the exact meaning of this is unclear. All patients had late postoperative liver-spleen scans that showed mean spleen size and function to be normal. We have described several methods of partial splenectomy used at Children's Hospital of Philadelphia. Recommendations for patients undergoing partial splenectomy include preoperative pneumococcus and Hemophilus influenzae vaccinations and prophylactic antibiotics postoperatively. The antibiotics are terminated if a liver-spleen scan and platelet count at the end of 3 months' time are normal.

Adolescent↗
PubMed1988

Pediatric neck masses: guidelines for evaluation.

Neck masses are frequent findings in the pediatric population. Unlike the adult, there are few established guidelines for evaluation of these children. The etiology of cervical masses includes many conditions. Knowledge of these conditions and their clinical presentations is essential. To elucidate the clinical characteristics which may help in establishing a correct diagnosis, the charts of 445 patients with biopsies of neck masses performed at the Children's Hospital of Philadelphia were analyzed. There were 244 (55%) congenital lesions, 118 (27%) inflammatory lesions, 23 (5%) non-inflammatory benign masses, 12 (3%) benign neoplasms, and 48 (11%) malignancies. The preoperative diagnosis was correct in 270 (61%) patients. Guidelines are established for the evaluation of the child presenting with a neck mass.

Adolescent↗
PubMed1988

The usefulness of open-lung biopsy in the pediatric bone marrow transplant population.

From October 1976 to October 1986, 126 children had bone marrow transplants at the Children's Hospital of Philadelphia. The indications were acute lymphocytic leukemia (ALL) (30), nonlymphocytic leukemia (24), aplastic anemia (15), solid tumors (47), and miscellaneous conditions (10). Of these, 21 (17%) underwent 22 open-lung biopsies. Fourteen of these patients showed no causative microorganism. When a cause was found it was viral (usually cytomegalovirus [CMV]) in three, fungal in one, Pneumocystis carinii alone in two, both viral and pneumocystis in one, and a combination of viral, bacterial, and pneumocystis in one. Thirteen patients died due to continued deterioration after the biopsy. In only two patients was there a significant change in antimicrobial therapy as a result of the biopsy. Both had Pneumocystis (one in combination with virus and bacteria). One patient with chronic infiltrates showed a lymphocytic interstitial pneumonia, which responded well to steroids. Open-lung biopsy is currently of limited value in this patient population. Survival is dismal unless the patient has Pneumocystis. We believe that prospective studies should be set up to compare open-lung biopsy with empiric antimicrobial therapy. A major emphasis must be on prevention.

Adolescent↗
PubMed1988

Resection with primary anastomosis for necrotizing enterocolitis: a contrasting view.

Resection with primary anastomosis is currently being advocated for treatment of infants with necrotizing enterocolitis. To determine whether our own data would support such an approach, we reviewed retrospectively our experience with this disease since 1974. Since that time, 173 infants have been admitted for treatment of advanced (surgical) disease in its acute phase, of whom 143 underwent resection for cure; the remainder either underwent laparotomy with decompression (3), laparotomy with drainage (3), laparotomy alone (14), died at operation (1), or could not be resuscitated sufficiently to withstand operation (9). Excluded were patients who underwent operative repair of late stricture (6), all of whom survived with no morbidity. Among those resected for cure, 27 infants were carefully selected by the operating surgeon for treatment by means of resection with primary anastomosis, based on the limited and apparently discrete nature of their disease; in three the procedure was combined with a decompressing enterostomy. In the majority of cases (14), the disease was found to involve multiple areas of intestine, but was limited to a particular anatomic region, usually distal ileum and/or ascending colon; in the remainder, it was due to discrete ileal or jejunal perforation or ulcer. Overall survival among those resected for cure was 65% (96/143). It was 48% (13/27) among those treated by means of resection with primary anastomosis but 72% (83/116) among those who underwent resection with enterostomy. However, if the early years of the series (1974 to 1976) are excluded, a time when resection with enterostomy had not yet become established as standard therapy, overall survival was 77% (77/100), 64% (9/14) among those anastomosed primarily.

Colon↗
PubMed1988

Surgical experience with thirteen conjoined twins.

Conjoined twins occur in approximately one in 50,000 or so births, and most do not survive. The authors report herein their experience with 13 conjoined twins over the last 30 years, involving those of the following forms: thoracopagus (4 cases), omphalopagus (1 case), ischiopagus (4 cases), pygopagus (1 case), craniopagus (1 case), and incomplete or parasitic varieties (2 cases). The various diagnostic and imaging studies used are described in detail for each form of twinning. Separation is best delayed until such infants are relatively mature (i.e., 6-12 months of age). Operative survival was 50% in those operated on in the neonatal period, but 90% in those over 4 months of age. Ten separations were attempted in 13 sets of twins, with 16 operative survivors. Significantly, up to 10 years after surgery, there were six late deaths due to serious associated congenital anomalies, predominantly cardiac. Improved recent survival is probably the result of the availability of more accurate imaging studies and better anesthetic and operative techniques, with great emphasis on performing immediate reconstruction whenever possible. Use of skin expanders and prosthetic mesh has facilitated wound closure. In the future, ex vivo cardiac reconstruction and autotransplantation may permit separation of twins with complicated conjoined hearts.

Female↗
PubMed1987

Kinetics and mechanism of the hydrolysis of a 2-substituted imidazoline, cibenzoline (cifenline).

The results of a kinetic and mechanistic study of the hydrolysis of a new antiarrhythmic agent, cibenzoline, are reported. The reaction is subject to specific base catalysis which proceeds via the protonated cibenzolinium ion. No evidence for the existence of a "pseudobase"-type intermediate could be found. The results support only one of two different mechanisms which have been proposed previously for the hydrolysis of this class of compounds.

Hydrogen-Ion Concentration↗
PubMed1987

Total intestinal aganglionosis: a new technique for prolonged survival.

Total small bowel aganglionosis is uniformly fatal; and prolonged nutritional treatment for the resulting severe short bowel syndrome in the absence of a therapy designed to achieve a functional bowel length has not been warranted. We report an operative technique, long segment small bowel myectomymyotomy, which has produced a functioning length of intestine capable of supporting ever increasing amounts of enteral nutrition. A term female was noted to have neonatal intestinal obstruction, and two laparotomies proved total colonic and near-total small bowel aganglionosis. At 2 months of age reoperation was done and the aganglionosis was proved to extend to 7 cm below the ligament of Treitz. From this transition zone to 10 cm distally, a myectomy was done removing a 1 cm wide length of seromuscular tissue to the level of the submucosa. From the distal end of the myectomy, another 40 cm of bowel received an antimesenteric border myotomy cutting to the submucosal level followed by spreading of the cut surface to a width of 1 cm. This left the patient with 55 to 60 cm of small bowel from the ligament of Treitz to the end of the myotomy at which point an end ostomy was created. The remainder of the small bowel was excised and the colon exteriorized as a mucous fistula. The patient was continued on total parenteral nutrition alone for ten days at which time small volume enteral feeds were introduced. By 5 months of age, 25% of calories were enteral; by 6 months, 33% of calories were enteral; and by 8 months, 45% of intake was enteral.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗