Pericentric inversion of chromosome 19 in three families

Summary Pericentric inversion of chromosome 19 has been found in several members of three unrelated families from a restricted geographical region. In one of the families, an additional pericentric inversion of chromosome 9 was observed. Reproductive problems, multiple abortions in two families and a neonatal death in the third, were present. A review of previously described cases is included, and the genetic risk connected with this type of rearrangement is also discussed.     

DR antigen expression on ovarian carcinoma cells does not correlate with their capacity to elicit an autologous proliferative response

Summary Expression of HLA-DR antigens by purified preparations of human ovarian carcinoma cells freshly isolated from surgical specimens was examined in parallel with the capacity of tumor cells to elicit a blastogenic response from autologous lymphocytes in mixed lymphocyte-tumor culture (MLTC) assay. Of 21 tumor preparations, 11 (52%) reacted with monoclonal antibodies 279 and/or 949 specific for a monomorphic determinant of HLA-DR antigens, with heterogeneous positivity, ranging between 30% and 95%. In this series of patients positive MLTC occurred in 8/21 individual experiments. The HLA-DR expression was proportionally similar in tumors giving positive MLTC (4/8=50%) and negative MLTC (7/13=53%). The lack of correlation between DR expression on tumor cells and stimulatory activity in autologous MLTC and the fact that DR-negative tumors could induce lymphocyte stimulation, support the hypothesis that blastogenesis occurs upon recognition of tumor-associated antigens, different from DR molecules, possibly tumor-specific antigens.     

Localization of the membrane-bound hydrogenase in Alcaligenes eutrophus by electron microscopic immunocytochemistry

Abstract The membrane-bound hydrogenase was localized in cells of Alcaligenes eutrophus by electron microscopic immunocytochemistry. Post-embedding labeling performed on ultrathin sections revealed that the enzyme was located predominantly (80%) at the cell periphery in autotrophically and heterotrophically grown bacteria harvested from the exponential phase of growth. In the stationary growth phase, however, only 50% of the enzyme was found at the cell periphery; the remaining 50% was distributed over the cytoplasm. The relative amount of electron microscopic label per cell as seen by application of the protein A—gold technique was higher in cells grown autotrophically as compared to cells grown heterotrophically on fructose. Derepression of the enzyme was followed electron microscopically in a substrate-shift experiment (growth on fructose, followed by a shift to glycerol). Major amounts of the enzyme appeared to undergo a reattachment to the cytoplasmic membrane under these conditions, starting with a reduced location of the enzyme in the cytoplasm and an accumulation in cell areas close to the cytoplasmic membrane. These findings indicate that the 'membrane-bound' hydrogenase (i.e., that material enriched as membrane-bound enzyme according to the appropriate activity test) is not, in fact, membrane bound or membrane integrated but membrane associated. It may or may not interact with the cytoplasmic face of the cytoplasmic membrane, depending on the growth phase and conditions.     

Prevalence of nits and lice in samples of cut hair from floors of barbershops and beauty parlors in Belo Horizonte, Minas Gerais State, Brazil

A louse survey based on samples of cut hair collected from floors of barbershops and beauty parlors was conducted in Belo Horizonte, Minas Gerais State, Brazil, from October 1984 to April 1985, as an alternative way to determine the prevalence of pediculosis capitis in the population. Of 475 samples examined for nits, nymphs, or adults of Pediculus capitis, 140 were infested (29.5%). A total of 58 lice and 3,553 nits were found in 33,632.9 g of hair collected, giving a ratio of 0.10 nit/g. Almost 29% of the nits were viable and capable of being transmitted after hatching. There was significant difference among the infestation rates by socioeconomic levels, and samples from barbershops with male customers were the most infested. Based upon the number of haircuts in each sample, we estimated that 5 or 6% of the population might be infested by this species.     

The Salmonella wien virulence plasmid pZM3 carries Tn1935, a multiresistance transposon containing a composite IS1936-kanamycin resistance element

Tn1935, a 23.5-kb transposon mediating resistance to ampicillin, kanamycin, mercury, spectinomycin, and sulfonamide was isolated from pZM3, an IncFIme virulence plasmid from Salmonella wien. Tn1935 possesses the entire sequence of Tn21 and contains two additional DNA segments of 0.95 and 2.7 kb carrying the ampicillin and kanamycin resistance genes, respectively. The latter is part of a composite element since it is flanked by two IS15-like insertion sequences (IS1936) in direct orientation. IS1936 is about 800 bp long and is closely related to IS15 delta, IS26, IS46, IS140, and IS176. Functional analysis of IS1936-mediated cointegrates shows that both insertion sequences are active and able to form cointegrates at the same frequency. Resolution of the cointegrates requires the presence of the host Rec system. The presence of the composite IS1936-element within Tn1935 supports the hypothesis that multidrug resistance transposons evolved by insertion of antibiotic determinants which are themselves transposable.     

Different lipid A types in lipopolysaccharides of phototrophic and related non-phototrophic bacteria

Lipid A analyses confirm not only the present taxa of the purple nonsulfur bacteria (formerly Rhodospirillaceae), but also phylogenetical relatedness of distinct phototrophic to distinct non-phototrophic bacteria, as was suggested by cataloguing 16S rRNA. For example, lipid A with ester-bound 3-OH-10:0 and the rare amide-linked 3-oxo-14:0 is common to the phototrophic Rhodobacter capsulatus and Rhodobacter sphaeroides and also to Paracoccus denitrificans and Thiobacillus versutus. 'Lipid ADAG' (lipid A with 2,3-diamino-D-glucose (DAG)) occurs in the phototrophic Rhodopseudomonas viridis and Rhodopseudomonas palustris and also in the related non-phototrophic species, e.g., Nitrobacter winogradskyi, Pseudomonas diminuta, or Thiobacillus ferrooxidans. The phylogenetically more coherent purple sulfur bacteria (Chromatiaceae) uniformly contain D-mannose in their phosphate-free lipid A. Among the green bacteria, only the Chlorobiaceae but not the likewise chlorosome-containing Chloroflexaceae contain lipopolysaccharide. Lipid ADAG from R. viridis is a structural analogue of a biosynthetic precursor (lipid X) of enterobacterial lipid A. Lipid A synthase from Salmonella accepts not only lipid X but also the synthetic di-N-acyl-2,3-diamino-D-glucose analogue as substrate (Raetz, C.R.H., unpublished results). More and more naturally occurring lipid A's with both, 2,3-diaminoglucose and glucosamine ('mixed' lipid A, with 2,3-diaminoglucose or glucosamine dominating) are being found. Newly recognized lipid A and lipid ADAG types might offer the possibility of differentially stimulating desired biological activities in animals without also having the undesired endotoxic activities. The non-toxic lipid A from Rhodopseudomonas viridis for example is able to stimulate prostaglandin secretion in peritoneal macrophages and can be used as an antagonist to the endotoxic shock caused by Salmonella lipopolysaccharide.     

Aspects of the reproductive biology of the bass, Dicentrarchus labrax L. I. An histological and histochemical study of oocyte development

Histological and histochemical studies of oocyte development in the bass, Dicentrarchus labrax L., showed that three types of inclusions are formed during vitellogenesis. Lipid yolk accumulates first as lipid droplets, followed by protein yolk in the form of discrete protein yolk granules. The third type of inclusion are the small cortical alveoli (intravesicular yolk/yolk vesicles, i.e.'carbohydrate yolk') which form in the peripheral cytoplasm after both the lipid and protein yolk have started to accumulate. While the protein yolk granules maintain their structural integrity through to maturation, forming a densely packed zone in the mid-outer cortex, the lipid yolk droplets continually coalesce and migrate centripetally, forming a prominent zone of large lipid droplets in the inner-mid cortex. From the histological study of oocyte development, a number of distinct developmental stages are delineated, while gross examination of the paired ovary revealed that, depending on its stage of development, it can be placed into one of seven maturity stages.     

Inhibitory effect of 11-ketoandrostenedione and androstenedione on spermatogenesis in the three-spined stickleback, Gasterosteus aculeatus L.

Stickleback males were implanted with Silastic capsules filled with 11-ketoandrostenedione or androstenedione at the end of the breeding season. 11-Ketoandrostenedione prevented the natural decline in secondary sexual characters and testes weight. It also completely inhibited the commencement of spermatogenesis, which normally takes place in late summer after having been quiescent during the breeding season. Androstenedione also exerted these effects, but to a lesser degree.     

Tricyclic Imipramine Modification of the Circadian Rhythms of Hypothalamic Serotonin, its Precursors and Acid Catabolite in Individually Housed Rats

Circadian rhythms of serotonin (5HT), its precursors tryptophan (TP) and 5-hydroxy-tryptophan (5HTP) and its acid catabolite 5-hydroxy-indoleacetic acid (5HIAA), were determined in the hypothalamus of control rats and rats which had been treated continuously with subcutaneous imipramine (10 mg/kg/day) for 2 weeks.

Rats were individually housed and entrained to LD12:12. Controls showed the 5HT and TP peaks in the light and dark periods respectively, as reported in the literature, but no inverted correlation (antiphase) between SHT and 5HIAA rhythms.

Imipramine significantly modified circadian rhythm characteristics: the 5HT acrophase was advanced, that of TP and 5HIAA was delayed. Imipramine also significantly increased hypothalamic SHT and TP concentrations.     

Structural relationship between the polyagglutinable antigen and the core polysaccharide of Pseudomonas aeruginosa

It has been observed that each strain of the Pseudomonas aeruginosa species harbours the so-called polyagglutinable antigen (PA). Some strains may produce it in a form which is linked to the core moiety of lipopolysaccharide (LPS) and this type of PA can thus be detected by passive haemagglutination using the isolated LPS as coating antigen. Other strains synthesize PA exclusively in a free form, which is also coextractable with LPS, its presence can, however, be demonstrated by the haemagglutination inhibition test. From a polyagglutinable strain of P. aeruginosa an R-type LPS was isolated having the core-linked PA. This LPS preparation was highly immunogenic with regard to its PA moiety. The core-bound PA seems to exert an immunosuppression on the core region, hence, the polyagglutinable strains isolated from cystic fibrosis patients only engender anti-PA antibodies, whereas antibodies against both, side chain and core region of LPS, are not engendered. The mucoid exopolysaccharide also contains the PA which could possibly play an important role in the patient by protecting P. aeruginosa cells against anti-PA antibodies.