Binding of homologous polymerized deoxyribonucleic acid by Streptomyces griseus

Germaine, G. R. (University of Minnesota, Minneapolis), and D. L. Anderson. Binding of homologous polymerized deoxyribonucleic acid by Streptomyces griseus. J. Bacteriol. 92:662-667. 1966-An irreversible P(32) deoxyribonucleic acid (DNA) binding system is described for Streptomyces griseus S104. The 69% guanine plus cytosine (GC) S. griseus DNA was bound by late exponential -early stationary phase cultures. Simultaneous addition of deoxyribonuclease with the P(32)-DNA to maximally receptive cultures reduced the uptake by 98%. Saturation of the binding ability occurred after 20-min incubation of cells with P(32)-DNA. Preparative cesium chloride density gradient centrifugation of the P(32)-DNA revealed that 98% of the label banded in the position expected for S. griseus DNA. Sedimentation of the P(32)-DNA at both 23 and 37 mug/ml indicated a molecular weight of 10.8 million. Attempts to transform S. griseus S104 auxotrophs to prototrophy by use of immediate and delayed selective procedures were unsuccessful.     

The Chilliwack Respiratory Survey, 1963: Part I. Methodology

In order to ascertain the prevalence of chronic respiratory disease in residents of a rural town and to determine the relative importance of tobacco smoking and air pollution, a survey was conducted of 726 persons living at Chilliwack, British Columbia, in May and June, 1963. Over 95% of a random sample of adults was interviewed and performed simple tests of respiratory function. The sample was selected from a commercial census. An analysis of the demographic characteristics of the sample indicated that the group, aged 25 to 74 years, was reasonably representative for detailed study of chronic respiratory disease.     

Metabolic origins of 5-hydroxytryptamine in enteric neurons in a teleostean fish (Platycephalus bassensis), a toad (Bufo marinus) and the guinea-pig

1. 5-Hydroxytryptamine (5-HT) content and synthesis in mucosa-free intestine of guinea-pig, the teleost Platycephalus bassensis and the amphibian Bufo marinus was studied by HPLC with electrochemical detection or by TLC. 2. The 5-HT content of small intestine was: guinea-pig 0.58; Bufo: 1.23; Platycephalus: 26.88 nmol/g. 3. Intestine from each species synthesized 5-HT from exogenous 5-HTP. 4. Platycephalus preparations synthesized labelled 5-HT from 14C-tryptophan, but no labelled 5-HT was detected after similar incubation of guinea-pig or Bufo preparations. 5. Incubation of guinea-pig preparations with tryptophan did not increase tissue 5-HT or 5-HIAA content. 6. 5-HT in Platycephalus enteric neurons may be synthesized from tryptophan in situ; 5-HT in Bufo and guinea-pig neurons may be synthesized elsewhere, perhaps in enterochromaffin cells.     

The bovine and ovine genomes contain multiple sequences homologous to the alpha-lactalbumin-encoding gene

Bovine and ovine (pseudo)genes homologous to the alpha-lactalbumin-encoding gene are described. In both cases, sequence analysis reveals homology extending downstream from exon 2. Southern analysis indicates the presence of a family of alpha-lactalbumin-related sequences in the bovine genome.     

A recessive mutation causing imperforate vagina in mice

A recessive mutation (ipv) causing imperforate vagina was discovered in a line of mice selected for low lean tissue mass as a proportion of body weight. Two full sisters were found to have marked swelling of the perineum and complete closure of the vagina. Crosses of heterozygotes identified by progeny testing produced a female progeny ratio not different from the 3 normal: 1 affected (chi 2 = 0.695; p less than .3) expected on the basis of a recessive allele at a single autosomal locus. As a consequence of the imperforate vagina, the uterus and vagina were greatly distended by fluid. The uterus of affected females displayed a swollen uterine lumen and thin endometrial stroma and muscularis. Ovarian tissue of affected females was similar to that of normal mice, and affected females produced ova that were normal in appearance. The mutation causing an imperforate vagina may present a useful model for studying the basis of abnormal vaginal development in other species and increasing the understanding of normal vaginal development in the mouse.     

Establishment of a leukemic cell model for studying human pre-B to B cell differentiation

Reproducible models for examining early stages of human B cell differentiation are poorly developed. We now describe the establishment and characterization of a novel human leukemic cell line that recapitulates the pre-B to B cell stage of differentiation. This cell line, designated BLIN-1, was initially established in tissue culture medium containing low m.w. B cell growth factor, and consistently shows a dependency on this cytokine for optimal growth at low density. BLIN-1 cells have a 9p chromosomal abnormality, identical to the abnormality present in the leukemic blasts from the patient's original bone marrow aspirate. The immunologic phenotype of BLIN-1 is consistent with a cell arrested at the pre-B cell stage of development. Analysis of Ig gene rearrangement and Ig expression in a series of BLIN-1 subclones show that the cells spontaneously rearrange kappa light chain genes, leading to the differentiation of surface kappa-negative pre-B cells into surface kappa-positive B cells. The BLIN-1 cell line is, to our knowledge, the first defined human model for examining this critical developmental stage in human B cell ontogeny. As such, it offers a unique resource for examining variables influencing onset of kappa L chain gene rearrangement and expression.     

Serotonin in human lumbar cerebrospinal fluid: a reassessment

An inter-laboratory comparison study was carried out in order to ascertain mean levels of serotonin (5-HT) in human lumbar cerebrospinal fluid (CSF). Analyses were performed using high performance liquid chromatography (HPLC) coupled with either electrochemical (LC-EC) or fluorometric (LC-F) detection. With the detection limits obtained (7-8 pg/ml for LC-EC, 7-15 pg/ml for LC-F) 5-HT was not usually detected in human lumbar CSF. The findings indicate that the true mean concentration of CSF 5-HT is less than 10 pg/ml. This upper limit is substantially lower than all previous reports of 5-HT concentrations in normal human lumbar CSF. The extremely low concentrations of 5-HT present in CSF make it unlikely that CSF 5-HT will be of clinical utility in assessing central serotonergic function.