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Biomedical subjects

S B Schwartz

Publications and source records attributed to S B Schwartz.

11 recordsLinked to original sources

Azithromycin prophylaxis during a hospital outbreak of Mycoplasma pneumoniae pneumonia.

Outbreaks of Mycoplasma pneumoniae (MP) in closed communities can have a high attack rate and can last several months. Azithromycin chemoprophylaxis has not been evaluated as a means of limiting transmission. This randomized, double-blinded placebo-controlled trial of azithromycin was conducted among asymptomatic hospital employees during an MP outbreak. Oropharyngeal swabs were obtained for detection of MP by polymerase chain reaction, and questionnaires were administered to assess clinical illness. Of the 147 employees who were enrolled, 73 received azithromycin and 74 received placebo. Carriage was similar within and between groups at weeks 1 and 6 (9.6% vs. 6.7% and 10.3% vs. 13.2%, respectively). Four episodes of clinically significant respiratory illness occurred in the azithromycin group versus 16 episodes in the placebo group (protective efficacy, 75%; 95% confidence interval, 28%-91%). Use of azithromycin prophylaxis in asymptomatic persons during an MP outbreak in a closed setting may be of value in reducing clinical illness.

Adult↗

Wound fluids: a reflection of the state of healing.

Analyzing acute and chronic wound fluids provides an important and intriguing insight into the wound milieu. This review outlines some of the salient features of wound repair and the wound fluid environment. Most studies support the premise that the contents of the wound fluid reflect the status of the wound and can be indicative of whether a wound is on the course of a normal or impaired response to injury. For example, chronic wound fluids often differ from acute wound fluids in their proliferative effects on cells active in healing as well as their proteolytic effects. The authors discuss various cytokines, growth factors, proteinases, and protease inhibitors within wound fluids as well as their effect on wound repair. This review also presents confounding factors affecting interpretation of wound fluid studies, suggesting that further studies need to elucidate mechanisms whereby wound fluids either enhance or inhibit wound repair. So far, wound fluid analysis has yielded tantalizing glimpses of the teeming wound environment. What wound fluid contents tell us about the wound or its clinical care is not yet certain.

Acute Disease↗

HPV 16 E6 blocks TNF-mediated apoptosis in mouse fibroblast LM cells.

The interaction between hosts and the viruses that infect them is a dynamic one, and a growing literature documents the fact that many viruses have developed mechanisms designed to avoid elimination by the host immune system. One of the immune strategies used by the host and targeted by virus proteins is apoptosis triggered by the cytokine tumor necrosis factor (TNF). Mouse fibroblast LM cells are spontaneously sensitive to TNF. When the wild-type E6 protein from the human papillomavirus type 16 (HPV 16) was expressed in LM cells, the cells became resistant to TNF. This resistance was examined by several means, including cell morphology, the dose- and time-independent response to TNF in a cell death ELISA, trypan blue exclusion, and cell proliferation. The level of p53 did not rise in TNF-treated cells prior to apoptosis, suggesting a p53-independent mechanism. Significant, though not complete, resistance to TNF was also observed following transfection of a plasmid expressing a mutant E6 protein, which is unable to mediate rapid degradation of the p53 tumor suppressor. These results indicate that the HPV 16 E6 protein can protect LM cells from TNF-triggered apoptosis and likely does so by a mechanism other than mediation of p53 degradation.

Animals↗

Clinical manifestations of Bordetella pertussis infection in immunized children and young adults.

STUDY OBJECTIVES: The incidence and prevalence of pertussis in adults have increased in recent years. It has been shown that previously immunized adults and adolescents are the main sources of transmission of Bordetella pertussis. The aim of this study was to describe the clinical presentation and the clinical course of pertussis in children and young adults who were immunized previously against B pertussis. DESIGN: Retrospective study. SUBJECTS: Children and young adults who were reported by local physicians to the Department of Epidemiology in the Israeli Ministry of Health with serologically confirmed pertussis and who were immunized previously were included. Information sought included personal data, epidemiologic data, signs and symptoms, laboratory results, initial diagnosis, and treatment. RESULTS: In the 95 previously immunized patients with serologically confirmed pertussis (mean age [+/- SD], 8.9 +/- 4.4 years old; range, 5 to 30 years old), the mean duration from onset of symptoms until the final diagnosis of pertussis was 23 +/- 15 days. The disease was usually atypical and generally mild. All the described patients had cough, usually prolonged, lasting 4 +/- 3.6 weeks. Only 6% had the classic whoop. The mean WBC count was 8.7 +/- 2.6 cells/mm6, and the lymphocyte count was 40 +/- 12%. Two patients were admitted to the hospital for severe pneumonia. Among the reported cases, the proportion of patients between the ages of 10 and 45 years increased from 6.5% during the period from 1971 to 1980, to 26% during the period from 1980 to 1990, and to 38% during a 1989 outbreak. CONCLUSIONS: Pertussis in previously immunized individuals is usually characterized by an atypical and relatively mild clinical course. Patients suffer mainly from a prolonged and persistent cough. Early diagnosis may lead to prompt administration of therapy. Prophylaxis of exposed persons might be effective in decreasing both severity and transmission of the disease.

Adolescent↗

Efficacy of corticosteroids in acute bronchiolitis: short-term and long-term follow-up.

Corticosteroids continue to be used by many physicians to treat infants with bronchiolitis. The aim of this study was to examine the short-term and long-term efficacy of oral corticosteroid therapy when added to beta2-agonists in infants with mild to moderate bronchiolitis (defined as the first episode of wheezing associated with low grade fever, rhinitis, tachypnea, and increased respiratory effort in a previously healthy infant during the winter months). Infants with mild to moderate bronchiolitis, were randomly assigned to receive either oral prednisone (2 mg/kg/day) or placebo for 3 days. All patients received nebulized albuterol q.i.d. during this period. Upon admission and after 3 days of therapy, a clinical score was assigned based on respiratory rate, use of accessory muscle, and the presence of wheeze. Oxygen saturation (SaO2) was also measured. On day 7, we inquired as to the well-being of each child. Two years later, the development of chronic respiratory symptoms was assessed. Thirty-eight infants were enrolled in the study; 20 received prednisone and 18 received placebo. Both groups were similar in terms of age, duration of illness prior to enrollment, pretrial medication use, clinical severity of bronchiolitis, history of atopy, and family history of atopy. After 3 and 7 days of treatment, both groups showed similar clinical improvement and there were no statistically significant differences between the two groups in the clinical score or in the SaO2. No major side effects were observed. Two years later, 32% of the infants continued to suffer from chronic respiratory symptoms, with a similar prevalence in both groups. We conclude that a 3-day course of oral corticosteroids is of no benefit to infants with mild to moderate bronchiolitis who are also treated with an inhaled beta2-agonist.

Acute Disease↗

Ventriculofemoroatrial shunt: a viable alternative for the treatment of hydrocephalus. Technical note.

Children with shunted hydrocephalus often have a myriad of other medical conditions. When these concomitant problems involve the pleura, peritoneum, and/or the venous system, placement of the distal catheter may prove to be problematic. This report presents preliminary results in three hydrocephalic children following ventriculofemoroatrial shunt placement. The peritoneal and pleural cavities in each of these children were compromised and there was no vascular access into the superior vena cava due to intercurrent disease. An alternative technique for ventriculoperitoneal shunt placement was performed via the femoral vein. Fluoroscopic guidance was used to confirm the intraatrial position of the distal end of the shunt catheter. Follow-up review to date shows no complications. This newly described technique provides a feasible alternative to distal shunt catheter placement in patients in whom more traditional sites are unavailable.

Cerebrospinal Fluid Shunts↗

Pediatric burns. An overview.

This article describes the management of burn injuries in children. It begins with an epidemiologic description of pediatric burns. Attention is given to emergency care, burn wound evaluation, operative management, and rehabilitative goals.

Burns↗

Chronic dysphagia, vomiting and gastroesophageal reflux as manifestations of a brain stem glioma: a case report.

Brain stem glioma is the third most common childhood brain tumor, comprising 10-15% of this group of neoplasms. Typical presenting symptoms include ataxia, diplopia and headache, while signs of increased intracranial pressure occur later in the clinical course. Although prolonged failure to thrive, characterized by cachexia and vomiting are rare manifestations of brain stem lesions, in this study we report a 9.5-year-old boy with failure to thrive since infancy which remitted after excision of a brain stem astrocytoma.

Astrocytoma↗