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Biomedical subjects

M G Caty

Publications and source records attributed to M G Caty.

At least 19 recordsLinked to original sources
PubMed2000

Attenuated nitric oxide synthase activity and protein expression accompany intestinal ischemia/reperfusion injury in rats.

Intestinal ischemia/reperfusion (I/R) leads to bowel impairment via the release of reactive oxygen species (ROS) and neutrophil infiltration. In addition to modulating intestinal integrity, nitric oxide (NO(*)) inhibits neutrophil activation and scavenges ROS. Attenuated endogenous NO(*) formation may result in the accrual of these deleterious stimuli. Therefore, we determined nitric oxide synthase (NOS) activity in anesthetized rats subjected to 1 h of superior mesenteric ischemia or ischemia followed by reflow. NOS activity was measured in intestinal tissue homogenates as the conversion rate of (3)H-L-arginine to (3)H-L-citrulline. Our results demonstrate that intestinal ischemia leads to a decrease in NOS activity indicating lower NO(*) formation in the animal model. The attenuation in NOS activity was not reversed following 4 h of reperfusion. Western blot analysis revealed that the decline in enzyme activity was accompanied by reduced intestinal NOS III (endothelial constitutive NOS) expression. These findings provide biochemical evidence for impaired NO(*) formation machinery in intestinal I/R injury.

Actins↗
PubMed1999

Does early ultrasonography affect management of pediatric appendicitis? A prospective analysis.

BACKGROUND: Appendicitis remains a difficult diagnosis in children. Ultrasonography is increasingly used for the diagnosis of appendicitis, although the proper clinical role for this test remains unclear. METHODS: To evaluate the clinical utility of ultrasonography in appendicitis, the authors analyzed prospectively all children evaluated for possible appendicitis from January 1 through December 31, 1997. Children with a high clinical suspicion of appendicitis were referred for surgery (n = 122). Children with equivocal findings of appendicitis were referred for early ultrasonography (EUS) and formed the study cohort (n = 103). An initial management plan was made to operate or observe each patient, and a risk of appendicitis (doubtful, possible, probable) was assigned by a pediatric surgery fellow. EUS was then performed, and its effect on management was assessed. RESULTS: Using clinical judgment to operate at initial presentation, the sensitivity was 38% and specificity was 95%. Using EUS alone, the sensitivity was 87% and specificity was 88%. The management of 30 of 103 patients (30%) was changed after EUS, including a decision to operate in 28 patients and a decision not to operate in two patients. CONCLUSIONS: EUS appears to have substantial clinical utility in children with equivocal findings of appendicitis, and its use complements the clinical management. The use of EUS can improve patient care and reduce hospital resource utilization.

Adolescent↗
PubMed1999

Observation of splenic trauma: when is a little too much?

A 12-year-old boy was treated conservatively for a grade II splenic laceration. On discharge, he was instructed to avoid contact sports, running, and strenuous physical activity. Thirty-eight days later, after diving off the side of a swimming pool, he had abdominal pain, nausea, and diaphoresis. On admission, he was hemodynamically unstable. Results of a diagnostic lavage showed gross blood. At laparotomy, a fractured spleen was found, and splenectomy was performed. He recovered without complication. This case questions the activity restrictions placed on patients with conservatively managed splenic trauma. Avoidance of only contact sports and heavy exertion may be inadequate.

Child↗
PubMed1999

Molecular biology for the pediatric surgeon.

Molecular biology is leading a revolution in our understanding, diagnosis, and treatment of disease and will continue to do so. Medicine in the future will require a greater understanding of this field and its methods by medical practitioners. This report reviews the basic aspects of the field including recombinant DNA methods. Of particular importance is how molecular biology will impact pediatric surgeons. Accordingly, the final section of this report briefly reviews the molecular biology of three diseases commonly treated by pediatric surgeons.

DNA, Recombinant↗
PubMed1999

Bleeding in children caused by gastrointestinal vascular lesions.

Intestinal vascular malformations in infants and children are rare but must be considered in the differential diagnosis of gastrointestinal bleeding. Many vascular malformation syndromes have associated intestinal lesions. Localization of vascular lesions is essential for successful management. A variety of treatment options including laser photoablation, surgical resection, and other nonoperative therapies have been utilized to treat these disorders.

Adolescent↗
PubMed1999

Follow-up imaging studies in children with splenic injuries.

We undertook a retrospective study of pediatric blunt splenic injuries treated nonoperatively at our institution from 1990 to 1995 (n = 72) to assess the impact of serial computed tomography (CT) scans on the outcome. Median number of studies per child was three. The result showed that the appearance of the splenic injury remained unchanged or improved in 95% of the imaging studies obtained (116 of 122). Only one of five patients with an image suggesting a worsening splenic injury required operative intervention. There were no instances of missed injuries, delayed ruptures, or readmissions. We conclude that serial CT scans have limited follow-up value and should be used selectively.

Child↗
PubMed1998

Impact of bicycle helmet safety legislation on children admitted to a regional pediatric trauma center.

PURPOSE: The regional pediatric trauma center in Buffalo, NY, has been active in pediatric injury prevention programs, including community education and distribution of bicycle helmets, since 1990. Since June 1, 1994, the use of bicycle safety helmets for children under 14 years of age has been mandated by a state law in New York. The authors undertook this study to assess the impact of this legislation on the frequency of helmet use in children involved in bicycle crashes presenting to the regional pediatric trauma center, and to assess the impact of helmet use on the number and severity of head injuries. METHODS: Bicycle crash victims (n = 208) admitted to a regional pediatric trauma center from 1993 to 1995 were studied retrospectively. Head injuries were classified as concussion alone, skull fractures, intracranial hemorrhages (ie, epidural, subdural, and subarachnoid), cerebral contusions, or diffuse cerebral edema alone (without any other intracranial injury). Helmeted children (HC) were compared with nonhelmeted children (NHC) using chi2 and Fisher's Exact test. P value less than .05 was considered significant. RESULTS: Only 31 children (15%) wore helmets at the time of the crash. Helmet use increased from 2%, during the period of education alone, to 26% after the legislation went into effect (P < .00001). The proportion of children suffering head injuries was similar in both groups (HC, 68%; NHC, 61%; P = NS). However, the type of head injury was different. HC were more likely to sustain concussion alone (HC, 65%; NHC, 44%; P < .03). HC were less likely to have skull fractures (HC, 0%; NHC, 13%; P < .02), and exhibited a trend toward less intracranial hemorrhages (HC, 0%; NHC, 9%; P = NS), cerebral contusions (HC, 3%; NHC, 5%; P = NS), and cerebral edema (HC, 0%; NHC, 0.6%; P = NS). Excluding the isolated concussions, head injuries were noted in only one HC, compared with 30 NHC (P < .04). None of the three children who died wore helmets at the time of the crash, and all died of multiple head injuries. CONCLUSIONS: The bicycle helmet safety law resulted in a 13-fold increase in the use of bicycle helmets among the children admitted to a regional pediatric trauma center after bicycle crashes, but the helmet use remains inadequate. Helmet use reduced the severity of head injuries, and might have prevented deaths caused by head injuries.

Bicycling↗
PubMed1998

Cervical ECMO cannula placement in infants and children: recommendations for assessment of adequate positioning and function.

BACKGROUND/PURPOSE: Cervical extracorporeal membrane oxygenation (ECMO) cannula position is often difficult to confirm by chest x-ray alone. Malposition requires a second surgery to rectify the problem. Reoperation places the patient at risk for infection, bleeding, or death. This study analyzes indications for cannula repositioning and suggests an alternative standard for intraoperative evaluation of catheter function as it relates to position. METHODS: The authors reviewed charts of 73 patients placed on arterio-venous ECMO through cervical vascular access. Reasons for repositioning of either cannula at the initial surgery or postoperatively were recorded. RESULTS: Of 73 patients, 18 (24.6%) required either arterial cannula or venous cannula repositioning. In 10 (55%) of these patients, cannula malposition was not detected by chest x-ray during the initial cannulation, and they therefore required a second cervical exploration for repositioning. CONCLUSIONS: Chest x-ray is not sensitive in demonstrating malpositioned cervical ECMO cannulae. Two-dimensional ECHO before wound closure, may be a superior, more cost effective means of assessing cannula placement and function than x-ray alone. Confirmation of cannula position and function, before wound closure, would reduce the risks involved with cervical reexploration.

Catheterization↗
PubMed1998

Fluid therapy for the pediatric surgical patient.

The fluid management of the pediatric surgical patient is a crucial aspect of surgical care. This article reviews the fundamental physiology of fluid replacement in children and highlights how standard formulas for fluid therapy can be modified to account for the rapidly changing physiology of the pediatric surgical patient. Novel approaches to fluid treatment of the surgical patient with oral rehydration formulas are discussed. Finally, guidelines for specific management of common pediatric surgical diseases are presented.

Appendicitis↗
PubMed1998

The approach to common abdominal diagnosis in infants and children.

This article focuses on salient points in the evaluation of abdominal pain in infants and children. Specifically, the authors address appendicitis and abdominal pain associated with either vomiting, constipation, or gastrointestinal bleeding. A discussion of common abdominal masses, urologic, and gynecologic problems, and considerations in the evaluation of immunologically suppressed or neurologically impaired children, and children with recurrent abdominal pain is also presented. The authors establish logical, focused approaches to the initial evaluation and management of abdominal pain and suggest criteria for timely surgical referral.

Abdominal Pain↗
PubMed1998

Pediatric hernias and hydroceles.

Hernias and hydroceles are common conditions of infancy and childhood, and inguinal hernia repair is one of the most frequently performed pediatric surgical operations. As a result of improved neonatal intensive care, more and more premature babies are being delivered, and consequently the incidence of neonatal inguinal hernia is increasing. The most important aspect of the management of neonatal inguinal hernias relate to its risk on incarceration, and emphasis is placed on this point. This article covers the embryology, incidence, clinical presentation, and treatment of groin hernias and hydroceles, as well as dealing with abdominal wall hernias other than umbilical hernias. This article places special emphasis on when a patient with a hernia or hydrocele should be referred to a pediatric surgeon.

Female↗
PubMed1998

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↗
PubMed1998

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↗
PubMed1998

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↗
PubMed1997

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↗
PubMed1997

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↗
PubMed1997

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↗