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Biomedical subjects

M G Caty

Publications and source records attributed to M G Caty.

At least 37 records · Page 2Linked to original sources

Pediatric umbilical problems.

After birth, the normal umbilicus is a relatively simple structure. During the development of the embryo, however, this region is highly complex. Vestigial of the umbilical cord can be responsible for umbilical inflammation and drainage. This article reviews the embryology of the umbilicus and discusses a number of clinical problems seen in this area. The authors' aim is to aid the primary care pediatrician in evaluating, treating, and appropriately referring umbilical problems encountered in office practice.

Female↗

The approach to common abdominal diagnoses in infants and children. Part II.

Part I (August 1998 issue, Pediatric Clinics), discussed appendicitis and common abdominal diagnoses in infants and in children associated with vomiting, as well as special considerations in the evaluation of immunologically suppressed and neurologically impaired pediatric patients. In this article, the authors continue to discuss the evaluation of constipation, gastrointestinal bleeding, common abdominal masses, and recurrent abdominal pain.

Abdominal Neoplasms↗

Care of the surgical intensive care nursery graduate. The primary care pediatrician's perspective.

Care of the intensive care nursery graduate may be quite challenging. It is important that primary care pediatricians become familiar with the complications unique to surgical patients so that they may properly prepare and educate parents and provide appropriate long-term follow-up for these often complex patients. Maintenance of a close relationship with the pediatric surgeon with an open line of communication regarding the approach to various surgical problems facilitates the effective integration of the intensive care nursery graduate into the primary care pediatrician's practice and provides the foundation for a successful clinical outcome.

Algorithms↗

Mucosal protection from intestinal ischemia-reperfusion reduces oxidant injury to the lung.

The authors investigated whether amelioration of intestinal mucosal injury, due to ischemia-reperfusion (I/R), with oxygenated perfluorocarbon (PFC) would reduce an oxidant-generated lung injury. The small intestine is increasingly recognized as a primary effector of distant organ injury. Clinical and experimental studies suggest oxidant species and activated neutrophils as the agents responsible for lung injury after intestinal I/R. The role of intestinal mucosal injury has not been defined. Oxygenated PFC was perfused through the lumen of the intestine during periods of I/R. Portal venous effluent was examined for reactive oxygen species and lung tissue was examined for lipid peroxidation. Luminal perfusion of oxygenated PFC during intestinal I/R reduced oxidant species in the portal blood. This correlated with a reduction in lung lipid peroxidation. Oxygenated PFC prevented intestinal mucosal injury resulting from induced I/R. Amelioration of mucosal injury reduced oxidant generation in the portal venous circulation that was proportional to the reduction in measured lung injury. Protection of the mucosa with intraluminal oxygen may prevent I/R-associated lung injury.

Animals↗

Oxygenated intraluminal perfluorocarbon protects intestinal muscosa from ischemia/reperfusion injury.

Ischemia/reperfusion (I/R) injury to the intestinal mucosa occurs in several commonly encountered clinical situations, such as necrotizing enterocolitis and nonocclusive mesenteric insufficiency. No clinically feasible technique is available for mucosal preservation during ischemia. The goal of this work was to determine whether the continuous intraluminal flow of oxygenated perfluorocarbon (PFC) could protect mucosal integrity and function in a rat model of intestinal I/R injury. Rats were subjected to ischemia by clipping the superior mesenteric artery (SMA) for 60 minutes. Reperfusion was achieved by release of the clip for 120 minutes. Animals were divided into 4 groups: Sham (laparotomy alone), I/R (I/R alone), I + PFC/R (PFC was administered during the ischemic interval only), I/R + PFC (PFC was delivered only during reperfusion). Tissue sections were examined blindly to assess mucosal integrity, and mucosal dissacharidase activities were measured to assess function. Oxygenated PFC, when administered during ischemia alone, ameliorated I/R-induced mucosal injury; however, when it was delivered during reperfusion alone, the mucosal injury worsened. When oxygenated PFC was administered throughout I/R, the degree of mucosal injury was similar to the I + PFC/R group, and dissacharidase activities were preserved when compared with the I/R group. Intraluminal perfusion of oxygenated PFC during ischemia preserves mucosal function and integrity, and may offer a new treatment modality for a variety of mesenteric ischemic disorders.

Animals↗

Risk of hemorrhage and appropriate use of blood transfusions in pediatric blunt splenic injuries.

OBJECTIVE: To define changes in hematocrit (Hct) and the indications for blood transfusion in pediatric blunt splenic injury. DESIGN: Retrospective case series MATERIALS AND METHODS: All children with blunt splenic injuries from 1990 to 1995 were studied (n = 74). Transfusion practices were reviewed for the whole group. Thirty children with isolated splenic injuries who were not transfused were analyzed to document Hct changes (mean +/- 95% confidence intervals). MEASUREMENTS AND RESULTS: The Hct at presentation was 37 +/- 2%, which rapidly dropped to 31 +/- 2% (p < 0.05) within 24 hours. After remaining stable at that level for the next 5 days, the Hct rose to 33 +/- 4% on day 6 (p = not significant), 35 +/- 4% on day 7 (p = not significant), and 38 +/- 2% (p = not significant) on day 13 +/- 3. Fifteen children received transfusions, all but one of whom had suffered multiple injuries. The transfusion rate declined from 38% of children in 1990 to 10% in 1995. CONCLUSIONS: After the initial drop within the first 24 hours, the Hct remains stable and rises with time to reach the baseline by day 6. Transfusion rates have declined over time, and transfusions are now used almost exclusively in severely injured children with multiple injuries.

Blood Transfusion↗

Mucosa cell regeneration following intestinal ischemia/reperfusion injury in rats.

OBJECTIVE: To evaluate regeneration and proliferation of the mucosa cells following intestinal ischemia/reperfusion (I/R) injury. METHODS: Sixty rats (200-250 g) were examined after intestinal I/R injury with immunohistochemical (BrdU) method and flow cytometric analysis. RESULTS: Severe damage to the villi was evident at 2 hours reperfusion and the rate of cell proliferation was lower (P < 0.01). All the specimens has healed mucosa with re-epithelialized villi tips after 2 days regeneration, but the villi were scarce and tiny. After two and four days regeneration, the rate of cell proliferation was significantly higher than that of controls (P < 0.01). CONCLUSIONS: Our study suggests that the intestinal regeneration following I/R injury in rats occurs early. The immunohistochemical method with BrdU-labeled technique is a rapid method for quantifying the rate of cellular DNA synthesis.

Animals↗

Insurance-related differences in the presentation of pediatric appendicitis.

In the pediatric population, there is strong evidence to suggest that a delay in treatment results in an increased risk of appendiceal perforation. However, it is not clear whether this delay arises from the parent seeking medical advice, the referring physician seeking surgical consultation, or the surgeon deciding to operate. To resolve this issue, the authors performed a retrospective chart review of all cases of confirmed acute appendicitis that presented to the pediatric surgical service of the Children's Hospital of Buffalo during a 4-year period (January 1990 through December 1993). All children (< or = 16 years of age) were categorized with respect to type of insurance coverage:Medicaid (or uninsured), health maintenance organization (HMO), or private fee-for-service. Their time until emergency room (ER) presentation, operating room (OR) presentation, and hospital discharge were recorded and compared. Their complications and perforation rates also were noted. Two hundred eighty-eight cases were reviewed. The rate of appendiceal perforation was significantly higher among the Medicaid patients (Medicaid, 44%; HMO, 27%; private, 23%; P < .05); their duration of symptoms before presentation was significantly longer (Medicaid, 47.3 +/- 4.1 hours; HMO, 29.3 +/- 1.9 hours; private, 23.1 +/- 2.5 hours; P < .01), and their hospital stay was longer (Medicaid, 7.9 +/- 0.9 days; HMO, 4.8 +/- 0.27 days; private, 4.6 +/- 0.44 days; P < .01). However, there were no significant differences in the time from presentation to the ER until definitive surgery in the OR. Children covered by Medicaid (or uninsured) presented later, had a higher risk of appendiceal perforation, and required a longer hospital stay. The parents of these children either failed to recognize the significance of their children's symptoms, or delayed seeking medical advice because of financial or logistical reasons. The gatekeeper consultation, required by the health maintenance organizations (HMO) did not result in a delay in presentation or have a negative impact on morbidity. Providing easier access to a primary care physician and improving parental health education/awareness may shorten the time until presentation for the uninsured/Medicaid patient.

Acute Disease↗

Neutrophil activation and chemotaxis after in vitro treatment with perfluorocarbon.

The in vitro effects of perfluorocarbon (PFC) on human neutrophil activation and chemotaxis were examined. Neutrophils were incubated, with and without PFC, and were analyzed for chemotaxis through 5-microns and 8-microns pore filters. Neutrophil activation was quantitated by flow cytometry. Activation studies showed that PFC-treated neutrophil samples (n = 6) produced only 39.83% +/- 25.9% (mean +/- SD) of matched control (n = 6) fluorescence. Chemotaxis studies showed that PFC-treated neutrophil samples (n = 8) had migration of only 18.63% +/- 6.5% (of control values) of neutrophils to the outer boundary of the 5-microns filters (n = 8 controls). The 8-microns pore filter migration (n = 8) was similarly low, with a mean outer boundary migration count of only 26% +/- 19.8% of the control (n = 8) value. Thus, neutrophils exposed to perfluorocarbon produce significantly less detectable H2O2 (P < .001) and have a significantly lower chemotactic response (P < .001).

Chemotaxis, Leukocyte↗

Teratomas in childhood.

Teratomas are embryonal neoplasms consisting of tissues from at least two of the three germ layers. Teratomas can occur in almost any region of the body and in any organ, but they are most commonly observed in the paraxial and midline locations. Excluding teratomas of the testes, 75% to 80% of teratomas occur in females. Approximately 80% are benign and 20% are malignant. The presenting location of teratomas correlates with patient age. Teratomas occurring in infancy and early childhood are usually extragonadal, whereas older children predominantly present with gonadal teratomas. The most common site of occurrence in neonates is in the sacrococcygeal and presacral region. Prognosis depends on patient's age, the resectability of the tumor, and the presence of metastases or metastatic potential.

Adolescent↗

Primary antiphospholipid syndrome in a child with lower extremity arterial thrombosis.

Primary antiphospholipid syndrome is characterized by venous and arterial thrombosis, fetal loss, or thrombocytopenia in association with antiphospholipid antibodies and no associated disease process. The authors report a case of lower extremity thrombosis in a 12 year old who had primary antiphospholipid syndrome. To our knowledge, this is the first report of peripheral arterial thrombosis in primary antiphospholipid syndrome in the pediatric population.

Antiphospholipid Syndrome↗

Cytoprotection by diclofenac sodium after intestinal ischemia/reperfusion injury.

Intestinal injury resulting from ischemia/reperfusion (I/R) is of fundamental importance in clinical pediatric surgery. I/R injury results from inadequate oxygen delivery as well as a secondary inflammatory response involving neutrophils and oxidants. This study was designed to evaluate a novel use for diclofenac sodium (DS), a nonsteroidal antiinflammatory agent, and to compare it with traditional antioxidants in this setting. Rats were subjected to intestinal ischemia followed by reperfusion. When killed, samples were obtained for measurement of intestinal myeloperoxidase (MPO), a measure of neutrophil sequestration, as well as for adenosine triphosphate (ATP) content, a marker of tissue injury. Animals exposed to I/R injury had significant neutrophil sequestration in the intestine by 120 minutes of ischemia, and this persisted after 60 minutes of reperfusion. DS pretreatment did not prevent neutrophil sequestration in the intestine. Analysis of intestinal ATP content demonstrated a decrease in intestinal ATP after 120 minutes of ischemia, and this did not change with 60 minutes of reperfusion. Pretreatment with DS significantly attenuated this intestinal ATP depletion. Furthermore, with 120 minutes of ischemia and 60 minutes of reperfusion, ATP preservation with DS pretreatment exceeded that obtained using the following conventional antioxidants: a xanthine-oxidase inhibitor (lodoxamide), deferoxamine, dimethysulfoxide, and superoxide dismutase plus catalase. DS has a significant cytoprotective effect for intestine subjected to I/R injury, exceeding that of conventional antioxidants. DS does not attenuate injury by preventing neutrophil influx into injured intestine.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗

Abdominal tumors in infancy and childhood.

Detection of an abdominal mass in a child is an alarming finding for both parent and practitioner. Diagnostic studies including ultrasonography, computed tomography, and magnetic resonance imaging provide an accurate diagnosis in most cases. The current treatment of Wilms' tumor results in an 85% to 90% survival. Hepatoblastoma and neuroblastoma often present in an advanced stage and require preoperative chemotherapy before resection is attempted. Improved survival for children with these tumors awaits better detection, chemotherapy, and understanding of the biology of their growth.

Abdominal Neoplasms↗

Current diagnosis and treatment of pheochromocytoma in children. Experience with 22 consecutive tumors in 14 patients.

Pheochromocytoma is a rare tumor of childhood. In comparison with adults with pheochromocytomas, children have a higher incidence of bilaterality, familial association, and extra-adrenal location. Fourteen children with 22 tumors were treated during the period 1970 through 1988. Children presented at a mean age of 13 years. Most children (10 of 14) presented with sustained hypertension. The majority of tumors were located with a combination of computed tomography and iodine 131 metaiodobenzylguanidine scanning. Eight adrenal and six extra-adrenal tumors were resected. Four children underwent bilateral adrenalectomy. Follow-up data are available on 9 of the 14 children. All of these patients remain normotensive without medication. Preoperative examination of children with pheochromocytoma using the iodine 131 metaiodobenzylguanidine scan provides an accurate diagnosis of adrenal and extra-adrenal tumors, thus making feasible resection of this rare tumor with complete cure.

3-Iodobenzylguanidine↗

Histamine: a promoter of xanthine oxidase activity in intestinal ischemia/reperfusion.

Xanthine oxidase (XO)-derived oxygen radicals are thought to play an important role in the intestinal injury resulting from ischemia and reperfusion. In vitro data shows enhanced XO activity in the presence of histamine. Histamine is known to be released during intestinal ischemia and reperfusion. The purpose of this study was to evaluate the relationship between histamine and XO in vivo in intestinal ischemia/reperfusion injury. Using an established model of gut ischemia and reperfusion, portal venous plasma was obtained and assayed for histamine levels, XO activity, and xanthine dehydrogenase (XD) activity following injury. Intestinal ischemia for 120 minutes resulted in a 200% increase in plasma histamine levels (263.4 +/- 36.9 nmol/mL control, v 548.7 +/- 35.1 nmol/mL experimental, P less than .05). Reperfusion for 15 minutes resulted in a further increase in plasma histamine (to 658.3 +/- 33.9 nmol/mL), compared with 120 minutes of ischemia alone. No significant change in plasma XO activity resulted after simple ischemia for 120 minutes. However, XO activity doubled within 15 minutes of reperfusion of the ischemic intestine (6.37 +/- 0.53 nmol O2- per milliliter per minute v 3.12 +/- 0.25 nmol O2- per milliliter per minute, P less than .05). Reperfusion for 60 minutes resulted in the maximal observed increase in plasma XO activity (9.49 +/- 0.67 nmol O2- per milliliter per minute). Analysis of XD activity demonstrated no significant decrease compared with controls until 120 minutes of ischemia and 60 minutes of reperfusion (1.62 +/- 0.49 nmol uric acid per milliliter per minute at 60 minutes of reperfusion, versus 5.02 +/- 0.52 nmol uric acid per milliliter per minute control, P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Embryonal rhabdomyosarcoma of the ampulla of Vater with long-term survival following pancreaticoduodenectomy.

Rhabdomyosarcoma of the biliary tree is a rare cause of biliary tract obstruction in childhood. A 3-year-old child is reported here after presenting with obstructive jaundice secondary to an embryonal rhabdomyosarcoma of the ampulla of Vater. He underwent pancreaticoduodenectomy followed by adjuvant chemotherapy and irradiation. He is now well and free of disease 5 years following treatment. This child appears to be the first long-term survivor who has required pancreaticoduodenal resection for this lesion.

Ampulla of Vater↗