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Biomedical subjects

S Strobel

Publications and source records attributed to S Strobel.

At least 73 records · Page 4Linked to original sources
PubMed1993

Degradation of glycosaminoglycans and fibronectin on endotoxin-stimulated endothelium by adherent neutrophils: relationship to CD11b/CD18 and L-selectin expression.

Vascular endothelial injury observed in overwhelming sepsis may be caused by neutrophil-derived enzymes. Adherence to the endothelium, a prerequisite for this process, is mediated sequentially by the neutrophil adhesion molecules L-selectin and the beta 2 integrins including CD11b/CD18. The relationship between expression of these molecules, neutrophil adherence, endothelial activation, and consequent endothelial injury was assessed by changes in heparan sulfate and fibronectin matrices. Endothelial prestimulation with lipopolysaccharide caused both an increase in adherence and a generalized reduction in heparan sulfate; disruption of the fibronectin matrix occurred only on the further addition of FMLP. Although maximal disruption of these matrices was associated with elevation of neutrophil CD11b/CD18 and reduction in L-selectin expression, these changes did not determine either the nature or extent of endothelial damage. This model may provide further insights into the interrelationship between neutrophil activation and endothelial damage in gram-negative sepsis.

Antigens, CD↗
PubMed1993

Noonan's and DiGeorge syndromes with monosomy 22q11.

A boy with the dysmorphic features of Noonan's syndrome and pulmonary valve stenosis who had evidence of hypoparathyroidism and abnormal T lymphocyte numbers in the neonatal period is reported. He had a normal karyotype but molecular analysis revealed a submicroscopic deletion within chromosome 22q11, the region deleted in DiGeorge syndrome. Thus this child has both Noonan's syndrome and DiGeorge syndrome; 22q11 is a candidate region for a gene defective in Noonan's syndrome.

Blotting, Southern↗
PubMed1993

Effects of a few food diet in attention deficit disorder.

Seventy-eight children, referred to a diet clinic because of hyperactive behaviour, were placed on a 'few foods' elimination diet. Fifty nine improved in behaviour during this open trial. For 19 of these children it was possible to disguise foods or additives, or both, that reliably provoked behavioural problems by mixing them with other tolerated foods and to test their effect in a placebo controlled double blind challenge protocol. The results of a crossover trial on these 19 children showed a significant effect for the provoking foods to worsen ratings of behaviour and to impair psychological test performance. This study shows that observations of change in behaviour associated with diet made by parents and other people with a role in the child's care can be reproduced using double blind methodology and objective assessments. Clinicians should give weight to the accounts of parents and consider this treatment in selected children with a suggestive medical history.

Attention Deficit Disorder with Hyperactivity↗
PubMed1993

Interleukin-8 release and neutrophil degranulation after pediatric cardiopulmonary bypass.

Capillary leak after cardiopulmonary bypass operations for correction of congenital heart defects is universally seen in children and often causes significant morbidity and mortality. Since neutrophil-mediated endothelial injury has been implicated as a pathogenetic mechanism, a prospective controlled descriptive study was performed to investigate possible activation pathways during and after the bypass procedure. Eighteen children undergoing operations, nine with cardiopulmonary bypass and nine neurosurgical craniotomy (i.e., operations without bypass), had samples of arterial blood collected at intervals before, during, and after operations. In six of nine cardiac patients circulating interleukin-8 concentrations rose from less than 30 pg/ml to very high concentrations (> 500 pg/ml); in the remaining three patients small rises (peak 57 to 81 pg/ml) were also seen. In all nine, the rise commenced at the time of rewarming, toward the end of bypass, and peaked 1 to 3 hours thereafter. Interleukin-8 release correlated significantly with length of bypass. Interleukin-1 alpha and interleukin-1 beta were not found, and traces of tumor necrosis factor-alpha were detected in one patient only. Circulating elastase alpha 1-antitrypsin concentrations rose simultaneously and correlated significantly with interleukin-8 (p < 0.001) in patients with cardiac disease, as did absolute neutrophil counts (p < 0.001). In contrast, only one of nine patients with neurosurgical disease (undergoing an unusually long operation and exchange transfusion) had a rise in circulating interleukin-8 to levels greater than 500 pg/ml (p < 0.01). The two samples from this patient with elevated interleukin-8 were the only neurosurgical samples with elevated elastase. This study demonstrates the release of interleukin-8 into the circulation after pediatric hypothermic cardiopulmonary bypass and supports the suggestion that this cytokine plays a role in the pathophysiology of capillary leak through neutrophil degranulation.

Cardiopulmonary Bypass↗
PubMed1992

Immunodeficiency presenting as hypergammaglobulinaemia with IgG2 subclass deficiency.

Recurrent bacterial infections, lymphadenopathy, and failure to thrive are unlikely to be attributed to immune deficiency if they occur in the presence of hypergammaglobulinaemia, and other explanations will usually be sought. We describe eight patients who presented with all these features in infancy or early childhood. Deficiencies of immunoglobulin and antibody production were initially discounted, and the children were referred for investigation of possible lymphoma, autoimmune disease, or chronic viral infection. The patients were later referred to us for more detailed immunological investigation, which revealed low levels of IgG2 and poor specific antibody production to common pathogens. Treatment with intravenous immunoglobulin resulted in resolution of signs and symptoms in all patients. Thus we have shown that hypergammaglobulinaemia does not preclude the presence of immunoglobulin/antibody deficiency. We suggest that investigation of children with high levels of IgG and features of immunodeficiency should include IgG subclass analysis.

Adolescent↗
PubMed1992

Tryptophan and serotonin metabolism in familial erythrophagocytic lymphohistiocytosis.

Reduced concentrations of tryptophan and 5-hydroxyindoleacetic acid (the major CSF metabolite of serotonin) were found in the cerebrospinal fluid of two children with familial erythrophagocytic lymphohistiocytosis. This was associated with elevated cerebrospinal fluid neopterin concentrations indicating increased macrophage activity within the central nervous system. In one child, cytotoxic therapy induced a complete clinical remission and an increase of tryptophan and 5-hydroxyindoleacetic acid concentrations to normal; during a subsequent relapse, concentrations of these analytes again fell below normal. In the other child, in whom therapy produced only a transient improvement, tryptophan and 5-hydroxyindoleacetic acid concentrations remained low and the child died. It is likely that increased activity of indoleamine 2,3-dioxygenase induced by the activation of macrophages was responsible for the disturbance in serotonin and tryptophan homeostasis within the brain. Excessive tryptophan catabolism and the disturbance of serotonin turnover may play a role in the aetiology of the neurological symptoms seen in familial erythrophagocytic lymphohistiocytosis.

Aging↗
PubMed1992

A study of mucosal gut immunity in infants who develop Hirschsprung's-associated enterocolitis.

The aim of this study was twofold. First, to establish quantitatively the distribution of the immunoglobulin-containing (plasma) cells, T and B lymphocytes in the lamina propria of the rectal mucosa of normal neonates and neonates with Hirschsprung's disease (HD). Second, to review the neonates with HD to determine any differences in these cell populations between those who subsequently developed Hirschsprung's enterocolitis (HEC) and those who did not. Two conclusions can be drawn from the results of our study of rectal mucosal immune defenses. First, neonates with HD have no deficiencies in these defenses when compared with normal neonates. Second, neonates with HD who subsequently develop HEC have no premorbid deficiency in these defenses. It was noted that the pan-T cell count in the infants who went on to develop HEC appeared to be increased, although this did not reach statistical significance. The use of fresh or frozen material would permit a more detailed analysis of the separate T cell subsets.

Child, Preschool↗
PubMed1992

Dietary manipulation and induction of tolerance.

Clinical observations have suggested that the development of atopic diseases in childhood may be influenced by breast-feeding and the timing of first exposure to foreign protein, but the controversy is far from being resolved. Early weaning and introduction of foreign proteins (i.e., cow milk) have been associated with an increased prevalence of atopic symptoms in infants with a family history of atopy. Opposite results have been reported, and the effects of early protein introduction in infants not at risk of having atopic symptoms are poorly documented. Research in rodents suggests that perinatal antigen exposure is more likely to prime the immune system than to induce tolerance. Continuous feeding beyond the critical neonatal period leads to induction of tolerance. The immunologic response is dependent on the antigen dose. Protein transfer by breast-feeding can induce tolerance, though in a dose range otherwise associated with priming. The protective effect of antigen avoidance in infancy on the development of cow milk allergy and also on subsequent atopic symptoms is well documented. Protective effects have been observed in infants at risk who either were breast fed or received a hydrolyzed infant formula. Several clinical studies suggest a causative role of neonatal milk exposure in the development of cow milk allergy. Prospective, population-based studies are required to assess the true incidence of food-allergic diseases in childhood.

Age Factors↗
PubMed1992

Effects of brief early exposure to partially hydrolyzed and whole cow milk proteins.

Clinical experience ("the dangerous bottle") and experimental evidence indicate that the early life of an infant is particularly important for the development of the immune responses to food antigens. However, the clinical and immunologic consequences of a brief exposure to, or avoidance of, food antigens during the neonatal period in human infants are poorly understood and documented. We present the preliminary results of a prospective controlled study of 256 normal breast-fed infants randomly assigned to receive (blind) either an adapted formula (Nidina) or a partially hydrolyzed formula (Nidal HA) as a supplement to breast-feeding for a few days when necessary, and to be examined at days 5, 90, 150, and 365. The results indicated that (1) the prevalence of clinical symptoms and of total and specific IgE responses was not statistically different in the two groups of infants and (2) infants fed a hydrolyzed formula had median titers of specific IgG lower than those fed an adapted formula; the difference was significant for alpha-lactalbumin at day 90 (p < 0.005) and for alpha-lactalbumin (p < 0.05), casein (p < 0.05), and hydrolyzed formula (p < 0.01) at day 150. Humoral immune responses of breast-fed infants to food antigens thus appear to be modulated by early, short-term exposure to them.

Breast Feeding↗
PubMed1991

Successful bone marrow transplantation and treatment of BCG infection in two patients with severe combined immunodeficiency.

We report successful bone marrow transplantation (BMT) in two patients with severe combined immunodeficiency (SCID), who had developed BCG infection following neonatal vaccination. Patient 1 had Omenn Syndrome, associated with hypertrophic non-obstructive cardiomyopathy. Patient 2 had SCID due to adenosine deaminase deficiency. This communication demonstrates that with appropriate anti-mycobacterial cover, immunological reconstitution together with full recovery from BCG infection can be achieved by BMT. As demonstrated by persistent negative Mantoux tests, specific cell-mediated immunity to BCG was not acquired following BMT. We suggest that these children may continue to be at risk from mycobacterial infection.

Adenosine Deaminase↗
PubMed1991

Erythroderma, palmoplantar keratoderma and profound failure to thrive in an infant.

The case is reported of a female infant, who at the age of 3 months developed severe erythroderma, marked hyperkeratosis of the palms and soles and subsequently extreme growth failure and intermittent diarrhoea. Her course was complicated by life-threatening infections but detailed investigation revealed no recognized underlying metabolic or immune abnormality.

Dermatitis, Exfoliative↗
PubMed1991

Short stature/short limb skeletal dysplasia with severe combined immunodeficiency and bowing of the femora: report of two patients and review.

We report two patients with severe combined immunodeficiency and short stature/short limb skeletal dysplasia. Case 1 presented at birth with rhizomelic shortening of the extremities and bowing of the femora. She developed clinical signs of severe combined immunodeficiency at 13 months and died at 21 months. Case 2 had severe prenatal shortening and bowing of the extremities and a small, malformed chest. Symptoms of severe combined immunodeficiency and severe failure to thrive developed soon after birth and she died at 5 months. The diagnosis of severe combined immunodeficiency in our patients was based on their clinical course and necropsy findings, supported in case 1 by the results of immune function tests. The results of investigation of immune function (immunoglobulins, lymphocyte subpopulations, lymphocyte function) are very variable in this syndrome as in other variants of severe combined immunodeficiency. Bone histopathology in both patients showed grossly irregular costochondral junctions, but normal transition of proliferating to hypertrophic chondrocytes. These cases belong to early lethal type 1 short limb skeletal dysplasia with severe combined immunodeficiency. Review of previously published cases with severe combined immunodeficiency and well documented skeletal findings show eight patients with prenatal onset of bowing and shortening of the extremities and metaphyseal abnormalities. These include two sib pairs concordant for the skeletal changes. In these cases, adenosine deaminase levels were not reported. An additional four published cases with associated adenosine deaminase deficiency had only mild metaphyseal abnormalities, but subsequently showed no linear growth.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Deaminase↗