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Biomedical subjects

B Landing

Publications and source records attributed to B Landing.

14 recordsLinked to original sources
PubMed1995

Increased neutrophil respiratory burst in bcr-null mutants.

Philadelphia (Ph)-positive leukemias invariably contain a chromosomal translocation fusing BCR to ABL. The BCR-ABL protein is responsible for leukemogenesis. Here we show that exposure of bcr-null mutant mice to gram-negative endotoxin led to severe septic shock and increased tissue injury by neutrophils. Neutrophils of bcr (-/-) mice showed a pronounced increase in reactive oxygen metabolite production upon activation and were more sensitive to priming stimuli. Activated (-/-) neutrophils displayed a 3-fold increased p21rac2 membrane translocation compared with (+/+) neutrophils. These results connect Bcr in vivo with the regulation of Rac-mediated superoxide production by the NADPH-oxidase system of leukocytes and suggest a link between Bcr function and the cell type affected in Ph-positive leukemia.

Actin Cytoskeleton↗
PubMed1990

Soft tissue calcification in pediatric patients with end-stage renal disease.

Soft tissue calcification is a recognized complication of uremia in adult patients and has been implicated as a cause of ischemic necrosis, cardiac arrhythmias, and respiratory failure. However, soft tissue calcification has been regarded as rare in pediatric renal patients. Following a sudden death due to pulmonary calcinosis in an adolescent after renal transplantation, we retrospectively reviewed clinical, biochemical and autopsy data of 120 patients with uremia, on dialysis, or following renal transplantation cared for at Childrens Hospital of Los Angeles from 1960 to 1983. Soft tissue calcification was found in 72 of 120 patients (60 percent). Forty-three patients (36 percent) had systemic calcinosis (Group A): the most frequent sites of mineral deposition were blood vessels, lung, kidney, myocardium, coronary artery, central nervous system, and gastric mucosa. Vascular calcification was uniformly accompanied by deposits in other organs. Twenty-nine patients had small amounts of focal calcification (Group B) and 48 patients had no soft tissue calcification (Group C). By multiple logistic regression analysis, the use of vitamin D or its analogues, the form of vitamin D medication prescribed, the peak calcium x phosphorus product, the age at onset of renal failure, and male sex were jointly associated with calcinosis (Group A). Vitamin D therapy showed the strongest independent association with calcinosis and the probability of calcinosis was greater in patients receiving calcitriol when compared with dihydrotachysterol and vitamin D2 or D3. The duration of renal failure, peak serum calcium, serum calcium at death, serum phosphorus at death, and primary renal diagnosis, were not statistically associated with calcinosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcinosis↗
PubMed1989

A subacute rabbit model for hepatobiliary dysfunction during total parenteral nutrition.

Total parenteral nutrition (TPN) in children is associated with the complicating syndromes of cholestasis and cholelithiasis. The causes of these syndromes are not completely clear. Gastrointestinal hypomotility associated with enteral fasting may be involved in the pathogenesis of both syndromes. We compared weanling rabbits maintained solely on TPN with chow pair-fed and free-fed controls over a 10-day period. Gastrointestinal transit time, assessed with a solid marker technique, was significantly greater in the TPN-treated animals. No difference in intestinal or biliary bacterial flora was demonstrated by aerobic or anaerobic cultures. Gallbladder bile contained a higher percentage of lithocholic acid, unconjugated bilirubin, and total calcium in the TPN-treated animals. Markers of hepatic dysfunction were elevated in the serum of the TPN-treated animals. Mild steatosis and edema were the only histologic differences in the livers of the TPN-treated animals. We conclude that gastrointestinal hypomotility associated with enteral fasting plays a role in the pathophysiologic changes leading to TPN-associated hepatobiliary dysfunction. This dysfunction may be mediated by an increase in the absolute and relative concentrations of lithocholic acid in the bile of TPN-treated animals.

Animals↗
PubMed1982

Cerebellar coning and uncal herniation in childhood acute leukaemia.

188 cases of childhood leukaemia came to necropsy at Children's Hospital of Los Angeles between 1965 and 1978. The necropsy records show that cerebellar coning and/or uncal herniation occurred in 5 of 47 cases with central nervous system (CNS) leukaemia and in only 1 of 141 without meningeal or cerebral infiltration. A review of the 168 cases of acute lymphocytic leukaemia treated at the University Hospital, Kuala Lumpur, since 1968 revealed another instance of coning, which occurred in a patient with CNS leukaemia. 4 of these 7 children with coning and/or uncal herniation did not have papilloedema, and the diagnosis was made only at necropsy. Coning was recognized 48 h after lumbar puncture in 2 children. In the other 5 cases, there was no relation between coning and lumbar puncture. This life-threatening complication should be considered before patients with CNS leukaemia are subjected to lumbar puncture.

Age Factors↗
PubMed1980

X-linked lymphoproliferative syndrome registry report.

Immune deficiency, especially to the Epstein-Barr virus, and increased susceptibility to fatal infectious mononucleosis, acquired agammoglobulinemia, and lymphoma are the cardinal features of the X-linked lymphoproliferative syndrome. Since the establishment of the XLP Registry in September, 1978, 59 affected males in seven unrelated kindreds were comprehensively studied. A spectrum of lymphoproliferative phenotypes was observed. Thirty-four patients (57%) died from infectious mononucleosis, eight (14%) had fatal infectious mononucleosis with lymphoma (immunoblastic sarcoma), nine (15%) had depressed immunity following EBV infection, and eight (14%) developed lymphoma. Several patients with XLP lacked EBV antibodies despite infection by EBV. The results of this study suggest that EBV can be an oncogenic agent in patients who are immune deficient with XLP.

Adolescent↗
PubMed1978

Initial urinary catecholamine metabolite concentrations and prognosis in neuroblastoma.

Initial urinary catecholamine metabolite and amino acid excretion patterns were examined in 54 children with neuroblastoma. The relationships between prognosis and age at diagnosis, stage of disease, primary site, and histologic grade of tumor were similar in this population to those found in previous studies, but only age and stage were found to be independent prognostic variables. Prognosis in disseminated disease was found to correlate directly with the urinary vanilmandelic acid (VMA)/homovanillic acid (HVA) ratio but not with the absolute levels of HVA. The presence of the dopa metabolite, vanillactic acid, as well as increased amounts of cystathionine and/or low levels of VMA indicated poor prognosis. These results are consistent with the hypothesis that biochemically primitive neuroblastomas deficient in dopamine beta-hydroxylase are move virulent than their mature analogues which produce epinephrine, norepinephrine, and their metabolites.

Adrenal Gland Neoplasms↗
PubMedDate not supplied

Scleroderma-like changes in insulin-dependent diabetes mellitus: clinical and biochemical studies.

Children with insulin-dependent diabetes mellitus (IDDM) were examined for scleroderma-like changes of digital sclerosis and joint contractures. Of the 104 patients, 19 (18%) demonstrated these features; five patients had both multiple joint involvement and skin changes; three were studied in detail. All three had restrictive pulmonary disease. Histopathology of skin in these three patients demonstrated increased accumulation of collagen in the lower dermis. In two of the patients, the extractability of collagen in 0.5 N acetic acid was decreased by about 50% as compared with normal controls, which suggests increased cross-linkage of collagen. In addition, the mean nonenzymatic glycosylation of collagen in these three patients was 13 times that of controls. The results indicate that distinct histopathologic and biochemical changes can be detected in the skin of these patients. The results further support the hypothesis that nonenzymatic glycosylation may alter the turnover of collagen, thus contributing to the development of a scleroderma-like syndrome with skin, joint, and pulmonary findings in patients with IDDM.

Adolescent↗