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Biomedical subjects

M Kleiman

Publications and source records attributed to M Kleiman.

At least 19 recordsLinked to original sources

Treatment of ovalbumin-induced experimental allergic bronchitis in rats by inhaled inhibitor of secretory phospholipase A(2).

BACKGROUND: The pathophysiology of asthma involves the action of inflammatory/allergic lipid mediators formed following membrane phospholipid hydrolysis by phospholipase A(2) (PLA(2)). Cysteinyl leukotrienes are considered potent inducers of bronchoconstriction and airway remodelling. Ovalbumin (OVA) induced bronchoconstriction in rats is associated with increased secretory PLA(2) (sPLA(2)) activation and cysteinyl leukotriene production, together with suppression of cytosolic PLA(2) and prostaglandin E(2). These processes are reversed when the animals are pretreated systemically with an extracellular cell impermeable sPLA(2) inhibitor which also suppresses the early allergic reaction to OVA challenge. In this study we examine the capacity of the sPLA(2) inhibitor to ameliorate inflammatory and allergic manifestations (early and late bronchoconstriction) of OVA induced allergic bronchitis in rats when the inhibitor was administered by inhalation to confine it to the airways. METHODS: Rats sensitised with OVA were treated with the sPLA(2) inhibitor hyaluronic acid-linked phosphatidyl ethanolamine (HyPE). The rats were divided into four groups (n = 10 per group): (1) naïve controls (no sensitisation/no treatment); (2) positive controls (sensitisation + challenge with OVA inhalation and subcutaneous injection of 1 ml saline before each challenge; (3) sensitisation + challenge with OVA and HyPE inhalation before every challenge; and (4) sensitisation + challenge with OVA and treatment with subcutaneous dexamethasone (300 mug) before each challenge as a conventional reference. Another group received no treatment with HyPE during the sensitisation process but only before or after challenge of already sensitised rats. Pulmonary function was assessed and changes in the histology of the airways, levels of cysteinyl leukotrienes in BAL fluid, and the production of nitric oxide (No) and tumour necrosis factor alpha (TNFalpha) by BAL macrophages were determined. RESULTS: Inhalation of HyPE markedly suppressed OVA induced early and late asthmatic reactions as expressed by bronchoconstriction, airway remodelling (histology), cysteinyl leukotriene level in BAL fluid, and production of TNFalpha and NO by BAL macrophages. OVA induced bronchoconstriction in sensitised non-pretreated rats was also inhibited by inhalation of HyPE either before or after the challenge. CONCLUSIONS: These findings confirm the pivotal role of sPLA(2) in the pathophysiology of both the immediate allergic response and the inflammatory asthmatic process. Control of airway sPLA(2) may be a new therapeutic approach to the treatment of asthma.

Administration, Inhalation↗

Cross-reactivity in Histoplasma capsulatum variety capsulatum antigen assays of urine samples from patients with endemic mycoses.

We evaluated cross-reactivity in the antigen assay used for the diagnosis of histoplasmosis by testing urine samples from patients with disseminated fungal infections. The mycoses chosen for this study were selected on the basis of the observation that during clinical testing, cross-reactions may occur between Histoplasma capsulatum var. capsulatum, Paracoccidioides brasiliensis, Blastomyces dermatitidis, Coccidioides immitis, and Penicillium marneffei. We detected antigen in 12 of 19 patients with blastomycosis, 8 of 9 with paracoccidioidomycois, in 17 of 18 with P. marneffei infection, and in one with disseminated H. capsulatum var. duboisii infection. Cross-reactions were not observed in the assays for six patients with disseminated coccidioidomycosis. Cross-reactivity between the agents of other endemic mycoses should be considered in interpreting a positive H. capsulatum var. capsulatum antigen assay. Antigen detection may provide a rapid, provisional diagnosis for patients with serious infections caused by one of these organisms.

Antigens, Fungal↗

Magnetic resonance differentiation of acute and chronic osteomyelitis in children.

A comparison has been made of the MRI findings of 17 studies in 16 patients with osteomyelitis: eight studies were performed in patients with acute osteomyelitis, six in chronic and three in healed osteomyelitis. Soft tissues, cortex and marrow were assessed in all patients. The best predictors of acute osteomyelitis were poorly defined soft tissue planes, absence of cortical thickening, and a poor interface between normal and diseased marrow. In contrast, chronic osteomyelitis was suggested by the presence of well-defined soft tissue abnormality, thickened cortex, and a relatively good interface between normal and diseased marrow. The appearance of osteomyelitis did not vary in different anatomic sites.

Acute Disease↗

Origin of organisms infecting ventricular shunts.

Results of skin cultures obtained before 413 of 505 operations for cerebrospinal fluid-diverting ventricular shunt placement or revision in a pediatric population from April 1980 to May 1983 are analyzed and compared to results of cultures from 20 subsequent shunt infections. Sensitivities to 11 different antibiotics were determined for each isolate cultured. The total operative infection rate was 20 of 505 (4%). Gram-negative bacilli alone accounted for 3 of 20 (15%) shunt infections. One gram-negative bacillus/Staphylococcus aureus infection occurred. Factors predisposing for gram-negative bacillus shunt infection were found in all 4 cases. The majority of shunt infections were caused by typical resident skin organisms: Staphylococcus epidermidis alone, 9/20 (45%); Staphylococcus aureus alone, 4/20 (20%); Corynebacterium sp., 1/20 (5%); alpha-Streptococcus with S. epidermidis, 1/20 (5%); and Micrococcus with S. epidermidis, 1/20 (5%). Only 4 (20%) of the 20 shunt infections were due to organisms identical to those originally grown from the skin. Another 4 (20%) seemed to be infected with a strain of organism different from that initially recovered from the skin. The remaining skin organism shunt infections may or may not have come from the patient's skin. The data suggest that not all skin organism shunt infections arise from contamination by resident skin bacteria at the incision sites at the time of operation. Alternate sources for the infecting organisms are discussed. The antibiotic sensitivity data on skin isolates and shunt isolates suggest that vancomycin is the antibiotic best suited for prophylaxis against shunt infection at our institution.

Adolescent↗

Magnetic resonance evaluation of disease of the soft tissues in children.

Magnetic resonance imaging was a sensitive modality for identifying pathology in the soft tissues of 32 children, and it consistently showed more abnormality than CT. Magnetic resonance images are not histology specific, but with careful attention to the location of the abnormality, to the definition of the margins, and to the evaluation of involvement of adjacent muscle, bone, subcutaneous fat, and skin, the correct diagnosis can be strongly predicted in most cases. The ability of magnetic resonance to image in multiple planes aids in the evaluation of the extent of lesions and their relationship to adjacent structures. With magnetic resonance imaging, one can accurately predict the extent of abnormality, and there is great potential for the study of disease of soft tissues.

Child↗

Staphylococcus epidermidis sepsis in pediatric patients: clinical and therapeutic considerations.

This report concerns 60 children with documented Staphylococcus epidermidis sepsis. There were 34 boys and 26 girls, ages 2 weeks to 15 years. The primary diagnosis included malignancy (13), congenital (13) or acquired (11) gastrointestinal disorders, prematurity (7), cardiac defect (5), hydrocephalus (2) and miscellaneous (9). Clinical presentation included fever (54), tachycardia (15), lethargy (20), hypotension (8), irritability (6), increased gastric residuals (6) and apnea/bradycardia (3). A documented source of sepsis was noted in 56 patients, including percutaneous central venous catheters (23), Broviac catheters (17), umbilical arterial catheters (6), wound (3), V-P shunt (2), cardiac defect (2), cholangitis (1), chest tube (1) and peripheral arterial line (1). There were six sepsis-related deaths, four in premature infants. Two of six infected subclavian catheters were treated successfully with vancomycin. Infection was successfully cleared in 20 of 23 infected Broviac catheters with vancomycin through the line. However, six were eventually removed for tract infection (1), persistent fever (2), and Candida sp. infection (3). Although once considered a non-pathogenic skin contaminant, S. epidermidis has emerged as a serious pathogen in hospitalized, immunosuppressed, premature and malnourished pediatric patients. Indwelling catheters enhance the likelihood of infection in these patients. Aggressive antimicrobial therapy is vital in this potentially lethal infection. Vancomycin proved efficacious in this series.

Adolescent↗

Long-term outpatient amphotericin B therapy via a silicone central alimentation catheter.

A 6-yr-old boy with systemic histoplasmosis received intravenous amphotericin B for two months as an outpatient utilizing techniques developed for home parenteral nutrition. The therapy was administered on alternate days in the emergency room by nurses trained to use aseptic technique. No complications occurred. The merits of this technique include avoidance of prolonged hospitalization with its high cost and risk of nosocomial infection and better patient acceptance with the patient living at home and continuing many of his usual activities.

Ambulatory Care↗

Immunoglobulin M and G histoplasmal antibody response in histoplasmosis.

Radioimmunoassays for IgM and IgG histoplasmal antibodies were developed and proved to be specific for their respective immunoglobulin classes, sensitive, and reproducible. Elevated IgM antibodies were detected in 59.8% of patients with histoplasmosis and 7.9% of control subjects. Elevated IgG antibodies occurred in 80.4% of patients with histoplasmosis but in only 12.9% of control subjects. Radioimmunoassay was nearly twice as sensitive as complement fixation for identifying patients with mild, presumably asymptomatic, infection. Of 13 patients with serologic follow-up at least 1 yr later, elevated IgM antibodies cleared, whereas IgG antibodies persisted in 7. In an epidemiologic investigation of a recurrent histoplasmosis outbreak, only the radioimmunoassay was able to prove the hypothesis that construction for a swimming complex was the source of exposure. These assays promise to be useful for clinical and epidemiologic investigations.

Antibodies, Fungal↗

Congenital rectal stenosis: a sign of a presacral pathologic condition.

Congenital rectal stenosis may be detected in the newborn during the initial physical examination. Failure of conservative therapy (dilatation) should alert the physician to the presence of an associated pathologic condition in the presacral space. Presacral teratoma, anterior sacral meningocele, or bony anomalies may be the underlying extrinsic causes of congenital rectal stenosis. Prompt recognition and appropriate operative management directed at the presacral lesion will relieve obstructive symptoms and minimize morbidity.

Anus, Imperforate↗