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Biomedical subjects

M Norman

Publications and source records attributed to M Norman.

At least 109 records · Page 6Linked to original sources
PubMed1985

Macrophage chemotaxis in anti-tubular basement membrane-induced interstitial nephritis in guinea pigs.

Interstitial renal lesions containing T cells and macrophages develop after 14 days in guinea pigs immunized to produce anti-tubular basement membrane-induced interstitial nephritis. We serially examined the renal venous and systemic arterial sera from such animals to determine if chemotactic factors were released across their kidneys. Our findings demonstrated the presence of a macrophage-specific renal chemoattractant with peak detectability on Days 10-14, just subsequent to the deposition of alpha TBM-Ab, but prior to the development of significant renal injury. We propose that such factors may provide important communication signals in the immunopathogenesis of this form of interstitial injury.

Animals↗
PubMed1984

Comparison of isotope dilution technique and haematocrit determination for blood volume estimation in rats subjected to haemorrhage.

The method of posthaemorrhagic blood volume (BV) determination by simple haematocrit measurement has been compared with the conventional isotope dilution technique. 51Cr tagged erythrocytes and 125IHSA were used to estimate RBC volume and plasma volume in non-starved male Sprague-Dawley rats. Two series of experiments were carried out by two different investigatory groups. Haemorrhage was inflicted by 60 or 90 min of haemorrhagic hypotension at 70 mm Hg, causing 41% and 56% loss of the initial estimated BVs, respectively. There was agreement in both series for the initial blood volume indices; RBC volume, 2.82 ml x 100 g-1 b.wt.; plasma volume 3.33 ml x 100 g-1 b.wt. and F cells, 0.91. Using the RBC volume data, the calculated residual BVs after haemorrhage corresponded accurately to the isotope measurements in both series. It is concluded that non-splenectomized rats may be used for accurate BV analysis after haemorrhage if the basal data for the strain used are known.

Animals↗
PubMed1984

Ureteroceles in children: clinical study and report of 58 cases.

Fifty-eight children with ureteroceles are the subject of this study. The lesions occurred more commonly in females and affected the left urinary transport system predominantly. Ectopic ureterocele was the most common type and virtually always developed on the ureter originating from the upper renal unit of a duplex kidney. There was a high incidence of associated urinary tract obstruction or vesico-ureteral reflux. The most common presenting symptoms were those of urinary infection followed by discovery of an abdominal mass. A characteristic filling defect in the bladder was seen on excretory urogram, and voiding cystourethrography revealed vesicoureteric reflux in 50% of the patients. Management of an infant or child with a ureterocele should begin with appropriate antibiotic treatment if infection is present, followed by excision or drainage of the involved renal segment(s). A pus filled upper pole and ureter may need to be removed or drained urgently in some ill patients. Ureteroceles are often complicated anatomic problems, which should be treated by surgeons who are familiar with the various facets of this congenital malformation.

Age Factors↗
PubMed1983

Fibrinogen degradation products in acute renal failure of the newborn.

Acute parenchymal renal failure (ARF) in the newborn infant has emerged as a major problem since the advent of neonatal intensive care units. Because intravascular and/or intrarenal coagulation may be important in the development of ARF, a prospective study of coagulation was performed on 20 babies with ARF, with particular emphasis on the measurement of fibrinogen degradation products (FDP) in serum and urine. Thirteen babies with respiratory distress syndrome (RDS) and 40 healthy neonates served as controls. Initial serum FDP levels were significantly higher in ARF than in RDS or normals (P less than 0.001); initial urine FDP levels were higher in ARF than in normals (P less than 0.01). Levels of FDP did not differentiate among the various etiologies of ARF. Since initial urine FDP levels are high in normal newborns, serial urine FDP were compared among patient groups and found to be highest in ARF. Initial serum and urine FDP levels could not differentiate among the 11 survivors and 9 nonsurvivors, but FDP levels declined as the duration of ARF (e.g., survival) increased, often antedating the recovery of renal function. We conclude: (1) serum and urine FDP are significantly elevated in most newborns with ARF; (2) factors other than hypoxia may be involved in the pathogenesis of elevated serum FDP in RDS with ARF newborns, indicating the importance of coagulation; (3) serial measurements of serum and urine FDP may be early indicators of recovery of renal function.

Acute Kidney Injury↗
PubMed1982

51Cr EDTA determinations of the extracellular fluid volume in hemorrhage: a study with fed and starved rats.

Extracellular fluid volumes have been determined in fed and 24-30 h starved rats, before and after 60 min of hemorrhagic hypotension at 70 mmHg. Bilateral renal vascular ligation was carried out to prevent clearance of the isotope tracer used, 51Cr EDTA. The time taken for a bolus of the tracer to distribute itself in its space, was determined in fed and starved animals after the standard period of hypotension. This was found to be 37 min for fed animals, and 50 min for those which had been starved. When the isotope ECF space was compared before and after hemorrhage in fed animals, it was unchanged, despite an estimated blood volume loss of 39%. The isotope ECF space was reduced 5.5% after hemorrhage in animals which had been starved. It is concluded that fed rats mobilised intracellular fluid to the interstitium in hemorrhage, whereas, starved animals did not. This finding of variable fluid homeostasis is ascribed to the different nutritional status of the animals investigated, and has considerable implications.

Animals↗
PubMed1979

Further characterization and biologic activity of ragweed antigen--induced neutrophil chemotactic activity in man.

We have previously described the appearance in serum of increased neutrophil chemotactic activity (NCA) during bronchospasm induced by inhalation of ragweed antigen in ragweed-sensitive subjects. This NCA is non-complement derived, appears within 1 min after antigen inhalation, and is not seen after methacholine-induced bronchospasm. This article describes further characterization of this chemotactic activity and correlation with in vivo leukocytosis. NCA consistently eluted in the void volume (fraction I) after Sephadex G-150 chromatography of patient serum obtained 10 min postchallenge. Fraction I contained 94% of the NCA of postchallenge whole serum. Both postchallenge whole serum and fraction I deactivated neutrophils to autologous chemoattractants and complement-derived chemotactic factors, but not serum-independent chemotactic factors. NCA was chemotactic for neither human nor guinea pig eosinophils, nor for human mononuclear cells. A significant increase of circulating neutrophils was seen only after antigen-induced bronchospasm and correlated with the increase in NCA. Thus, NCA represents another inflammatory mediator of probable mast cell origin that may explain, at least partially, the accumulation of neutrophils observed in the peripheral blood, skin, and bronchial wall after immediate hypersensitivity reactions.

Bronchial Provocation Tests↗