Physiological properties of cold-sensitive suppressor mutations of a temperature-sensitive dnaZ mutant of Escherichia coli.

Suppressors of a temperature-sensitive dnaZ polymerization mutant of Escherichia coli have been identified by selecting temperature-insensitive revertants. Those suppressed strains which concomitantly became cold sensitive were chosen for further study. Intragenic suppressor mutations, which caused cold-sensitive defects in DNA polymerization, were located in dnaZ by transduction with lambda dnaZ+ phages.

Genetic analysis of acrA and lir mutations of Escherichia coli.

An analysis of acrA (acriflavine- and methylene blue-sensitive) and lir (lincomycin- and erythromycin-sensitive) mutants of Escherichia coli indicated that these mutations are probably within the same gene.

Identification of hemoglobin G-Philadelphia (alpha 68 Asn replaced by Lys) and hemoglobin Matsue-Oki (alpha 75 Asp replaced by Asn) in a black infant.

Two alpha-chain variants, Hb G-Philadelphia and Hb Matsue-Oki, were present in members of a relatively large black family from South Carolina. The four Hb G-Philadelphia heterozygotes averaged 35.6% Hb G, suggesting the presence of an alpha-thalassemia-2 condition in cis to the Hb G mutation, which was confirmed by DNA structural analysis.

Phagocytosis of senescent neutrophils by human monocyte-derived macrophages and rabbit inflammatory macrophages.

An in vitro system to investigate the ability of macrophages to recognize and ingest senescent polymorphonuclear neutrophils has been used that uses chromium-labeled neutrophils and staining for myeloperoxidase (MPO). Human monocyte-derived macrophages obtained from in vitro cultures were able to recognize "aged" but not freshly isolated 51Cr-labeled human neutrophils and ingest them. Freshly isolated monocytes did not exhibit this property.

Pulmonary microvascular alterations and injury induced by complement fragments: synergistic effect of complement activation, neutrophil sequestration, and prostaglandins.

Fragments of C5 that are generated at, or administered to, extravascular sites in the pulmonary parenchyma induced neutrophil infiltration, edema, tissue damage, and a complete inflammatory response. Generation of C5 fragments within the vascular system induced leukocyte sequestration in the pulmonary vasculature, but without detectable increased vascular permeability or neutrophil migration. By contrast, the combination of short episode of hypoxemia with the intravascular C5 activation led significant increases in pulmonary vascular permeability, mild endothelial alterations, and emigration of neutrophils.

The Escherichia coli dnaW mutation is an allele of the adk gene.

A dnaW mutant, isolated on the basis of inability to effect conjugal DNA transfer at high temperature, has been shown by complementation and enzyme assay to be defective in the adk (adenylate kinase; EC 2.7.4.

The gamma chain heterogeneity of fetal hemoglobin in black beta-thalassemia and HPFH heterozygotes.

High pressure liquid chromatography (HPLC) was applied to the HbF isolated from blood of numerous black patients with beta-thalassemia trait or homozygosity, G gamma-delta beta-thalassemia trait, G gamma A-gamma HPFH heterozygosity, or the G gamma-[delta+ beta+]-HPFH condition. The method allowed an accurate evaluation of the relative quantities of three types of gamma-chain (G gamma, A gamma I, A gamma T) in the fetal hemoglobins. The results have shown the following.

A clinico-pathological study of fatal pulmonary embolism in a specialist orthopaedic hospital.

A study of post-mortem examinations performed between 1970 and 1979 at a specialist orthopaedic hospital revealed that the overall mortality rate due to pulmonary embolism was 0.23% and that pulmonary embolism was responsible for 19.1% of hospital deaths.

Carboxymethyl-cellulose microchromatography for the quantitation of hemoglobin Bart's (gamma 4) and its use in the detection of the alpha-thalassemia conditions.

A modification of an existing (micro) CM-cellulose chromatographic procedure is introduced for the quantitation of hemoglobin Bart's (or gamma 4) in blood samples of newborn babies. Normal newborn with four active alpha chain genes (alpha alpha/alpha alpha) have small amounts (average 0.55%) of this abnormal hemoglobin while increased percentages are present in newborn with an alpha-thalassemia-2 heterozygosity (alpha 0 alpha/alpha alpha; average 1.

The connective tissue component of the caprine arthritis-encephalitis syndrome.

The gross and microscopic connective tissue lesions in 12 goats with caprine arthritis-encephalitis (CAE) are described, including those from which a virus (CAEV) was isolated. Lesions were most often associated with synovial-lined structures including joints, tendon sheaths, and bursae, and were typified by synovial cell proliferations, subsynovial mononuclear cell infiltration, the presence of fibrin, fibrinous concretions, necrosis, and mineralization. Extrasynovial lesions were located in kidneys, vessels, and brain.

A differential effect of C5a and C5a des Arg in the induction of pulmonary inflammation.

Earlier studies have shown that C5 fragments induce an inflammatory reaction when instilled into the rabbit lung. Because C5a is rapidly converted to C5a des Arg in vivo, experiments were performed to determine which fragment was most effective in producing pulmonary inflammation in this animal model. C5a des Arg consistently produced marked inflammation.

Villous damage induced by suction biopsy and by acute ethanol intake in normal human small intestine.

Previous studies by us indicated that ethanol in concentrations of 2.0-4.8% produced subepithelial blebs in the jejunum of the hamster.

Lung inflammation induced by complement-derived chemotactic fragments in the alveolus.

The intratracheal injection into rabbits of low molecular weight C5-derived chemotactic fragments (C5fr), prepared from zymosan-activated serum, induced an acute pulmonary inflammation characterized by intraalveolar accumulation of neutrophils, erythrocytes, and edema fluid. In separate experiments, depletion of circulating pulmonary neutrophils and absorption of C5fr with immobilized antibody to homogenous human C5a prevented the observed inflammatory changes, indicating a requirement for these two elements in initiating this reaction. When examined by transmission and scanning electron microscopy, lungs of C5fr-injected rabbits revealed pulmonary neutrophils, often appearing partially degranulated, in alveolar, pulmonary capillary, and interstitial spaces.

Hemoglobinopathies observed in the population of the Southeastern United States (SE-USA).

A survey of nearly 250,000 citizens of Georgia and South Carolina conducted during the past twenty years has led to the detection of over 40 abnormal hemoglobins and several additional hemoglobinopathies. The presence of some of these hemoglobin abnormalities cause (severe) clinical symptoms but others remain undetected unless a specific search is initiated. The incidence of Hb S varies slightly among the populations of different areas, and appears to be the highest in the coastal counties of Georgia and South Carolina.

Isolation and characterization of dnaX and dnaY temperature-sensitive mutants of Escherichia coli.

Escherichia coli mutants with temperature-sensitive (ts) mutations in dnaX and dnaY genes have been isolated. Based on transduction by phage P1, dnaX and Y have been mapped at minutes 10.4--10.

Mechanisms of platelet response to monosodium urate crystals.

The mechanisms of urate-crystal-induced release of platelet constituents has been studied morphologically and biochemically. Urate crystals provoked an early energy-dependent release of the dense-body constituents serotonin, ADP, and ATP from washed platelets. Concurrently, platelet ultrastructure showed evidence of shape change, contractile wave, and aggregation.

Variability in the interaction of beta-thalassemia with the alpha-chain variants Hb G-Philadelphia and Hb Rampa.

Two unrelated families are reported in which beta-thalassemia trait occurred with a heterozygosity of Hb G-Philadelphia (alpha2 68(E17)Asn leads to Lys beta2) in one family and with Hb Rampa (alpha2 95(G2)Pro leads to Ser beta2) in the other. The percentage of Hb G-Philadelphia was not influenced by the simultaneous presence of a beta-thalassemai determinant, but that of Hb Rampa was descreased from 20% in the simple heterozygote to about 6% in persons with the Hb Rampa-beta-thalassemia combination. Data from in vitro recombination experiments with isolated alpha X, alpha A, and beta A chains, with heme attached, indicated a preferential formation of Hb A over Hb Rampa but not over Hb G-Philadelphia in conditions of relative beta-chain deficiency.

Comparison of the lesions of Aleutian disease in mink and hypergammaglobulinemia in ferrets.

Gross and microscopic lesions of Aleutian disease (AD) in mink and hypergammaglobulinemia in ferrets were compared. Both conditions were characterized by widespread proliferation of plasma cells, but proliferation was more prominent in mink infected with AD. Arteritis did not occur in hypergammaglobulinemic ferrets.

An outbreak of tularemia in mink.

An outbreak of tularemia in farm raised mink is reported. Twenty-six of approximately 5000 mink succumbed within a 10 day period. Prodromal signs were minimal.