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Biomedical subjects

R Pearl

Publications and source records attributed to R Pearl.

At least 19 recordsLinked to original sources
PubMed2000

Heterogeneity of popular boys: antisocial and prosocial configurations.

This study examined subtypes of popular 4th-6th grade boys (N = 452). Popular-prosocial (model) and popular-antisocial (tough) configurations were identified by means of teacher ratings and compared with peer and self-assessments and social centrality measures. Peers perceived model boys as cool, athletic, leaders, cooperative, studious, not shy, and nonaggressive. Peers perceived tough boys as cool, athletic, and antisocial. Model boys saw themselves as nonaggressive and academically competent. Tough boys saw themselves as popular, aggressive, and physically competent. Tough boys were disproportionately African American, particularly when African Americans were a minority in their classrooms. Model and tough boys were overrepresented at nuclear social centrality levels. These findings suggest that highly aggressive boys can be among the most popular and socially connected children in elementary classrooms.

Black or African American↗
PubMed1999

Pulmonary barotrauma in congenital diaphragmatic hernia: a clinicopathological correlation.

BACKGROUND/PURPOSE: The high mortality rate in congenital diaphragmatic hernia (CDH) has been ascribed to pulmonary hypoplasia and persistent pulmonary hypertension of the newborn (PPHN). One of the principal treatment strategies has been the use of hyperventilation to reverse ductal shunting, but the wisdom of this approach is being questioned because of parenchymal lung injury from high inflation pressures. The authors hypothesize that the use of hyperventilation to reverse or prevent ductal shunting would result in ventilator-induced lung injury, which would be evident on postmortem examination. A retrospective review of clinical and autopsy information was conducted. METHODS: Clinical and autopsy information gathered for a previously published series of 223 infants with CDH presenting in the first 24 hours of life was reviewed. Autopsy and clinical data were analyzed from 68 of 101 nonsurvivors who died with severe hypoxemia. RESULTS: Sixty-two of 68 cases (91%) had evidence of diffuse alveolar damage and hyaline membrane formation, which was more evident in the ipsilateral lung. Forty-four (65%) infants had pneumothoraces, and 4 infants had interstitial fibrosis. Pulmonary hemorrhage was seen in 35 cases (50 maximum peak inspiratory pressure [mean +/- SD] was 40.4+/-7.9 cm H2O and lowest modified ventilatory index [respiratory rate x peak airway pressure] was 2323+/-836). The degree of pulmonary hypoplasia was evaluated by lung weight with the ratio of the observed combined lung weight to the expected lung weight based on birth weight and gestational age. The ratio based on birth weight was 57%+/-25%, and the ratio based on gestational age was 60%+/-26%. Twenty-one infants (35%) had nonpulmonary anomalies. The most significant was a 10% incidence of congenital heart disease. Apart from this, lethal nonpulmonary anomalies were rare. CONCLUSION: These results suggest that lung injury secondary to mechanical ventilation plays an important role in the mortality rate of patients with CDH, which may become increasingly significant when there is underlying pulmonary hypoplasia.

Barotrauma↗
PubMed1998

Anorectal disease in HIV-infected patients.

PURPOSE: Anorectal diseases are common in human immunodeficiency virus-infected individuals. The aim of this prospective study was to assess the cause and clinical presentation of anorectal disease in this human immunodeficiency virus-infected population. METHODS: A registry of all human immunodeficiency virus-seropositive patients with anorectal complaints who were referred to and followed up in the colorectal surgery clinic at a county hospital was maintained, with all data collected prospectively. All patients underwent examination under anesthesia with random cultures and biopsies, along with specific sampling of any suspicious lesions. RESULTS: Data from 180 consecutive human immunodeficiency virus-seropositive patients with anorectal symptoms were analyzed. Mean age of the population was 34 years, with a male-to-female ratio of 14:1. This group comprised homosexual and bisexual males (55 percent), injection-drug users (15 percent), heterosexuals (12 percent), and others (18 percent). The average lag time from diagnosis of human immunodeficiency virus to anorectal symptoms was 48 months. The average CD4 lymphocyte count was 160 cells/mm3. The most common symptom was anorectal pain (57 percent), followed by lumps or warts (28 percent), rectal bleeding (12 percent), discharge (11 percent), and pruritus (6 percent), with 24 percent of patients having multiple complaints. Anal condyloma was the most prevalent pathology observed (43 percent), of which 10 percent was associated with anal intraepithelial neoplasia. Wide-based anal ulcers were the most frequent noncondylomatous lesions, occurring in 32 percent of patients, with the majority (91 percent) presenting with the chief complaint of anorectal pain. Some of these ulcers were associated with viral infections: herpes simplex virus (12 percent) and cytomegalovirus (7 percent). However, most ulcers were idiopathic, with negative cultures and biopsies. Other lesions encountered included fistulas (14 percent), abscesses (12 percent), hemorrhoids (6 percent), and malignancy, with two cases of Kaposi's sarcoma, one case of non-Hodgkin's lymphoma, and one case of squamous-cell carcinoma. More than one anorectal condition was identified in 16 percent of the patients. CONCLUSIONS: Human immunodeficiency virus infection is associated with a wide spectrum of anorectal disease, of which the most common lesions are anal condylomata and painful ulcers. The majority of these anal ulcers gave negative culture and biopsy results. In addition, there seems to be a high incidence of anorectal neoplasia in this patient population.

Adolescent↗
PubMed1998

Multidisciplinary evaluation of the distended abdomen in critically ill infants and children: the role of bedside sonography.

Abdominal distention and metabolic acidosis are common in critically ill infants and children, and can be manifestations of an intra-abdominal catastrophe. This series demonstrates the value of bedside sonography (US) in this difficult assessment. Eight infants and children presented with the above situation. Seven were immediately post-cardiopulmonary resuscitation and none had antecedent histories of abdominal pain or bilious vomiting. Abdominal radiographs could not rule out intra-abdominal pathology such as ischemic bowel. Review of all laboratory and radiological data showed US to be a discerning modality for acute bowel pathology. A characteristic pattern of echogenic ascites, thickened bowel wall, dilated, fluid-filled bowel lumen, and lack of peristalsis was seen in those children with gangrenous bowel. Sonographic examination accurately predicted the status of the bowel in all patients. Four patients survived: two had segmental ileal necrosis, one had localized gangrene of the jejunum (twice), and one had necrotic bowel from a closed-loop obstruction. The four who died had malrotation with volvulus (two), superior mesenteric venous thrombosis, and one was immunocompromised with pulmonary aspiration. We conclude that bedside US can be extremely valuable as an adjunct in assessing the abdomen and diagnosing gangrenous bowel in critically ill infants and children.

Abdomen↗
PubMed1997

Using genetic information to make surgical decisions: report of a case of a 13-year-old boy with colon cancer.

PURPOSE: We report the case of a boy aged 13 years who was diagnosed with a Dukes B obstructing cancer of the sigmoid colon. At the time of diagnosis, he underwent a Hartmann's procedure with end colostomy. Because of his unusually young age, he was referred to the Familial GI Cancer Registry at Mount Sinai Hospital for genetic assessment. A detailed pedigree revealed no significant history other than lung cancer in his maternal grandfather. METHODS: We obtained his tumor specimen and performed molecular analysis of both normal colonic and tumor DNA. Specifically, we identified replication errors (RER) in the patient's tumor DNA when compared with normal colonic DNA. RER has been found in more than 90 percent of tumors from patients with Hereditary Nonpolyposis Colon Cancer (HNPCC) and is, thus, considered to be one of the hallmarks of this disease. Because HNPCC patients have a 40 percent risk of synchronous or metachronous tumors, the recommended surgery for HNPCC should be at least a subtotal colectomy with ileorectal anastomosis. RESULTS: Based on molecular results, we were able to recommend that the patient have a subtotal colectomy performed instead of merely colostomy closure, to reduce his lifetime risk of developing further colon tumors and to make surveillance of the remaining rectum relatively easy. In this patient, we subsequently identified a germline mutation of the mismatch repair gene hMSH2 that is implicated in HNPCC. The possibility of HNPCC should be considered in adolescents who are diagnosed with colorectal cancer, so appropriate surgical decisions can be made.

Adenocarcinoma, Mucinous↗
PubMed1997

Congenital diaphragmatic hernia--a tale of two cities: the Toronto experience.

PURPOSE: The optimal therapy for congenital diaphragmatic hernia (CDH) is evolving. This study analyzes the results of treatment of CDH in a large tertiary care pediatric center using conventional and high-frequency oscillatory ventilation (HFOV) without extracorporeal membrane oxygenation (ECMO) contrasting these with a parallel study from a similar large urban center using conventional ventilation with ECMO. METHODS: Between 1981 and 1994, 223 consecutive neonates who had CDH diagnosed in the first 12 hours of life were referred for treatment before repair. Conventional ventilation was used with conversion to HFOV for refractory hypoxemia or hypercapnia, and a predicted near 100% mortality rate. ECMO was used in only three patients, all of whom died. A retrospective database was collected. Thirty-one clinical variables were tested for their association with the outcome. Common ventilatory and oxygenation indices were tested for their prognostic capability. RESULTS: Apgar scores, birth weight, right-sided defects, pneumothorax, total ventilatory time, and the use of high frequency oscillatory ventilation were the only variables associated with outcome. A modified ventilatory index and postductal A-aDo2 were strong prognostic indicators. From 1981 to 1984 surgery was performed on an emergency basis. Since 1985 surgery was deferred until stabilization had been achieved. This resulted in a shift in the mortality from postoperative to preoperative with no change in total survival. HFOV did not alter the overall survival. Results of autopsies performed (70%) showed significant pulmonary hypoplasia and barotrauma as the primary causes of death. The survival was 54.7%. CONCLUSION: Conventional ventilation with HFOV produced equal survival to conventional ventilation with ECMO in two comparable series. Pulmonary hypoplasia was the principle cause of death. This continued high mortality at both centers suggests that new therapies are required to improve outcomes.

Extracorporeal Membrane Oxygenation↗
PubMed1996

Imaging gastrointestinal perforation in pediatric blunt abdominal trauma.

OBJECTIVE: To assess the role of imaging, in particular CT, in the early detection of GI perforation. SUBJECTS AND METHODS: In a 10-year period, 43 patients with surgically confirmed GI perforation were identified from hospital records; 22 of these had preoperative CT evaluation. Medical records and radiology were retrospectively reviewed and CT studies were particularly assessed for extraluminal air, free intraperitoneal fluid, bowel wall thickening, bowel wall enhancement, and bowel dilatation. During the study period an additional 12 trauma patients were identified who had CT studies demonstrating the above findings, but who had hypovolemic shock bowel or nondisrupting bowel injury without perforation evident. RESULTS: Extraluminal air was demonstrated in 47 % of the imaged perforations. There was one false-positive extraluminal air. Perforation was confirmed in patients who had all five of the above CT findings, but this was the case for only 18 % of patients with perforation. One or more of the five specified CT findings were present in all CT studies reviewed. No false-negative CT study was performed in the study period. CONCLUSION: Separating nondisrupting bowel injury from perforation is diagnostically difficult; however, CT remains a good modality for assessing GI perforation in pediatric blunt trauma, but it cannot replace diligent and repeated clinical evaluation of all potential perforation victims.

Abdominal Injuries↗
PubMed1996

Postnatal management of congenital diaphragmatic hernia.

The emphasis in postnatal management has shifted from the neonatal surgical emergency approach to strategies designed to deal with pulmonary hypoplasia and the pulmonary vascular abnormalities. There has been extensive experience with alternative ventilation strategies such as ECMO and high frequency ventilation, without there being convincing evidence that these have had a major impact on mortality. Strategies that emphasize the importance of minimizing ongoing lung injury, such as pressure limited (permissive hypercapnia) ventilation and the use of surfactant replacement therapy, are beginning to show some encouraging results.

Extracorporeal Membrane Oxygenation↗
PubMed1995

Conversational interactions of mothers and their preschool children who had been born preterm.

This study examined the conversational interactions of mothers and their 4.5-year-old children, who had been born preterm, during a social problem-solving task asking each dyad to agree on the choice of a snack. Relative to comparison mothers, mothers of preterm children seemed to approach the task as a vocabulary lesson; they produced less complex sentences and were more likely to name the snacks and to test their children's knowledge of snack names. Comparison mothers were more likely to focus on the social negotiation aspect of the task, by offering more opinions and reasons. Discussed is whether the conversational strategies of mothers of preterm children reflect appropriate "fine-tuning" or a lag in adjusting to their children's emerging language skills because of a lingering "prematurity stereotype."

Child Development↗
PubMed1995

Brief report: four years after a preterm birth: children's development and their mothers' beliefs and expectations.

Examined the development of preterm-born 4 1/2-year-olds who lived in environments free from socioeconomic disadvantages often associated with deleterious outcomes. Beliefs and expectations of their mothers were also assessed. Thirty-two preterm and 41 comparison children and their mothers participated. Results indicated that although the preterm children were performing at or above age norms on most measures, they scored lower than comparison children in receptive vocabulary, syntactic complexity, articulation, and visual-motor skill. In addition, preterm and comparison group mothers differed in some beliefs and expectations. Results suggest that a preterm birth remains a factor in development during the preschool period, even in a social environment most likely to provide compensatory mechanisms for preterm birth.

Analysis of Variance↗
PubMed1995

Antibody facilitation of multiple sclerosis-like lesions in a nonhuman primate.

In the human disease multiple sclerosis (MS), the immune mechanisms responsible for selective destruction of central nervous system myelin are unknown. In the common marmoset Callithrix jacchus, a unique demyelinating form of experimental allergic encephalomyelitis resembling MS can be induced by immunization with whole myelin. Here we show that the MS-like lesion can be reproduced by immunization against the extracellular domain of a single myelin protein, myelin/oligodendrocyte glycoprotein (MOG). By contrast, immunization against the quantitatively major myelin proteins myelin basic protein or proteolipid protein results in inflammation but little or no demyelination. Furthermore, in the presence of encephalitogenic (e.g., disease-inducing) T cells, the fully demyelinated lesion is reconstructed by systemic administration of IgG purified from whole myelin-, or MOG-immunized animals, and equally by a monoclonal antibody against MOG, but not by control IgG. Encephalitogenic T cells may contribute to the MS-like lesion through disruption of the blood-brain barrier that permits access of demyelinating antibody into the nervous system. The identification of MOG as a major target antigen for autoimmune demyelination in a nonhuman primate should facilitate development of specific immunotherapies for human MS.

Animals↗
PubMed1994

Getting caught in misconduct: conceptions of adolescents with and without learning disabilities.

This study examined adolescents' conceptions about how to respond after being caught in misconduct, in order to determine whether students with learning disabilities differ from nondisabled students in their beliefs regarding apprehension. A total of 88 students with learning disabilities (62 male, 26 female) and 84 nondisabled students (45 male, 39 female) were interviewed about 10 scenarios in which a teenager was caught by authorities after participating in misconduct, either alone or with a peer. The mean age of the students was 16 years (SD = 1.4). The results indicated that the students with learning disabilities were significantly more likely than other students to suggest escaping and less likely to suggest accepting the consequences, although the differences were not great. The implications of these findings are discussed.

Adolescent↗
PubMed1992

Efficacy of immobilization following aspiration of carpal and digital ganglions.

In a prospective study 69 carpal and digital ganglions were aspirated, multiply punctured, and digitally ruptured. Fifty percent of the wrists and digits were immobilized for 3 weeks and 50% were mobilized early. Follow-up was 1 year. Immobilization in our study did not significantly improve the results of treatment. During the course of the study, 51% of all ganglions did not recur. The outcome was successful in 52% of the wrists and digits that were immobilized and in 50% of those that were not. Forty-six percent of the dorsal carpal ganglions did not recur. Treatment was successful in 48% of dorsal carpal ganglions in which the wrists were immobilized and in 45% of those that were not. Similar percentages were found for palmar and digital ganglions. From our results, we conclude that immobilization does not significantly improve the successful treatment of ganglions over perforation and aspiration alone.

California↗
PubMed1992

Students' expectations about peer pressure to engage in misconduct.

Previous research suggests that students with learning disabilities may differ from other students in their expectations of how peers are likely to propose engaging in misconduct. This study followed up on these findings using a methodology that did not require the participants to produce their responses verbally. Participants were 74 students with learning disabilities (53 male, 21 female) and 85 students without disabilities (40 male, 45 female) from high schools in three types of communities (urban, primarily black; urban, primarily Hispanic; suburban, primarily white). The students were presented with a series of pairs of statements that might be made by a teenager trying to entice a peer into misconduct and were asked to indicate which statement in each pair was the more persuasive. The results partially replicated the earlier research. The methodological and social implications of these results are discussed.

Adolescent↗
PubMed1990

The management of vascular injuries associated with total hip arthroplasty.

Approximately 100,000 total hip reconstructions are done annually in the United States. The nature of the surgical technique in a field close to the iliac and femoral vessels makes the occurrence of vascular injury an occasional but serious complications. We have reviewed retrospectively our experience of five cases of vascular injuries with total hip replacement and an additional 63 cases in the literature to identify those patients at risk and to define the management of these injuries. For the entire group of 68 patients, most injuries were sustained on the left side (66%), and 39% were seen in revisions. Complications were related to cement incorporation of the iliac vessels (44%), aggressive medial retraction (17%), excessive traction on atherosclerotic vessels (10%), and improper technique in preparation of the acetabulum. The most commonly injured vessels were the external iliac artery (36), common femoral artery (17), and external iliac vein (6). Twenty-seven of these injuries required emergent surgery, most for hemorrhage (66%). Injuries consisted of thromboembolic complications leading to distal ischemia (46%), vessel lacerations (26%), pseudoaneurysms (25%), and arteriovenous fistulas (3%). Vascular repair was individualized and included suture repair, thrombectomy and patch angioplasty, embolectomy, and arterial and venous bypass procedures. There was an overall 7% mortality and a 15% incidence of limb loss. Risk factors include (1) revision procedures, (2) left-sided procedures, and (3) intrapelvic migration of the acetabular component of the hip prosthesis. Elective vascular workup and preliminary retroperitoneal exposure of the iliac vessels at time of hip arthroplasty is recommended for patients at risk.

Aged↗
PubMed1985

Cognitive-behavioral interventions for increasing motivation.

Interventions aimed at improving students' achievement behavior by promoting adaptive attributions for success and failure are described. Issues concerning identification of appropriate recipients of these interventions, content and method of training, and evaluation of treatment effectiveness are discussed.

Achievement↗