Two new ELISAs using monoclonal H-Y antibody

Biotin-conjugated monoclonal H-Y antibody was used to detect soluble H-Y antigen, directly, in two novel enzyme-based systems: a sandwich or 'capture' ELISA and an inhibition ELISA. In each case, soluble H-Y was readily detected in samples known to contain the antigen, provided that positive and negative samples were compared on an equivalent protein basis. By adding increasing concentrations of inhibitor (antigen) we define the useful range of the assays to be between 0.6 and 20.0 micrograms of added protein. Both sandwich and inhibition ELISAs gave similar results with antigens tested. The methods can accordingly be applied as direct diagnostics in the study of sex determination and in the assignment of gender.

Purification and analysis of a sex-specific antibody

Analysis of the male-specific H-Y antigen is difficult, in part, because of the tendency of "male-specific" antisera to bind cell surface components found in male and in female cells. Some insight as to the nature of that difficulty is provided by biochemical evaluation of H-Y antibody. In this study, purification of a monoclonal H-Y antibody with ammonium sulfate or Protein-A Sepharose, revealed the possibility of microheterogeneity. Despite evidence of multiple subtypes, Protein-A elution profiles suggested that the male-specific activity of the antibody resided in an IgG2a moiety. This was borne out by decreased activity after absorption of the IgG2a subtype with male cells, and by reaction of the monoclonal antibody with mouse subtype-specific antisera in an ELISA. Combined analysis using biological (absorption), biochemical (EF and PAGE) and immunological (ELISA) methods could find applicability in other complex systems.

Enzyme immunoassay of H-Y antigen: experimental and clinical applications

A newly developed enzyme-linked immunosorbent assay (ELISA) was applied for studying H-Y antigen in buffaloes, cattle, horses and humans. A monoclonal H-Y antibody was absorbed with cells from males or females and was then tested against fluid samples known to contain soluble H-Y antigen. In this system, positive absorption manifested itself by a fall in optical density relative to the optical density scored using unabsorbed antibody; this finding signified the presence of H-Y in the absorbing cells. In each of the four species, the fall in optical density was pronounced after absorption with male cells, but some decrease was also evident after absorption with female cells, indicating a degree of nonspecific attachment of the antibody.

Promoter recognition and promoter strength in the Escherichia coli system

The strength of Escherichia coli promoters in vivo as well as the rates of association between RNA polymerase and promoter sequences differ by more than an order of magnitude. Since efficient promoter recognition and rapid binding of the enzyme might be a prerequisite for exceptional promoter strength we have determined the forward rate constants kon (as well as koff) for nine promoters including PL, PA1, and PN25 from phages lambda, T7, and T5, respectively as well as Pbla and PlacUV5 from E. coli. The second order forward rate constants span a 30-fold range from 1 X 10(7) M-1 s-1 for Pbla and PL up to 2.9 X 10(8) M-1 S-1 for PN25. Little correlation between 'promoter recognition' as defined by the rate of complex formation of a promoter sequence with RNA polymerase and its strength in vivo as defined by the rate of RNA synthesis has been found. This adds to the evidence that the complex functional pathway encoded in a promoter sequence can be limited at various levels and that promoter strength in vivo is the result of an optimization process involving more than just one functional parameter.

Reaction of monoclonal H-Y antibody in the ELISA

Monoclonal H-Y antibody of demonstrated specificity was reacted with soluble H-Y antigen in a newly-developed enzyme-linked immunosorbent assay (ELISA). Typing of cell lines was accomplished by qualitative and quantitative absorption. In one case, the antibody was subdivided into equal portions, each of which was absorbed with 1, 3, 6 or 12 X 10(6) cells from male or female; after absorption, the cells were discarded and the antibody was titrated for residual activity in the ELISA. With increasing cell numbers, optical density scores for male-absorbed antibody approached baseline levels. Although male-female differences were pronounced and highly significant, there was also a fall in reactivity after absorption with female cells.

[Delayed development of hemispheric dominance accompanied by a rare form of retarded language development]

A severe and unusual form of retarded speech development in an eight-year old boy is analyzed as "right-hemispheric speech" against the background of neuropsychological theories on the specialisation of the cerebral hemispheres and considered in connection with the development of hemispheric dominance. A plan for therapy and teacher counselling is derived from this analysis. The influence of this retarded speech development on the acquisition of reading and writing is also touched upon.

Anaerobic degradation of halogenated aromatic compounds

Recent microbiological findings show how compounds, regarded hitherto as unusual substrates for anaerobic bacteria, are degraded under anaerobic conditions. The complete conversion of halobenzoic acids and halophenolic compounds to methane by lake sediment and sewage sludge microorganisms has been demonstrated. Since haloaromatic compounds are widely used and may be found in such effluents as those from the forest industry, these studies could stimulate a broader interest in anaerobic treatment of industrial waste waters which contain unusual organic compounds.

H-Y typing in the ELISA

In a series of quantitative absorptions, biotin-conjugated monoclonal H-Y antibody was reacted with a plated source of H-Y antigen in the ELISA. H-Y was demonstrated in testis supernatant fluid of the mouse in this system, and in cells from males of the mouse, bovine and human and females of the chicken, thereby confirming its evolutionary persistence, and underscoring its presumptive role in the primary determination of vertebrate sex.

On the secretion of H-Y antigen

It has been proposed that H-Y antigen secreted by cells of the Sertoli lineage is bound by receptors on these and other cells of the primordial gonad and thereby initiates formation of the testicular cords, and that H-Y is not an integral transmembrane component but a part of a ternary system with beta 2-microglobulin and products of the MHC. It follows that cultured Daudi cells, which lack beta 2-microglobulin and HLA, should secrete H-Y. This is consistent with evidence obtained with monoclonal H-Y antibody and an ELISA. By this method, free H-Y was demonstrable in the supernatant fluids of cultured Sertoli cells and Daudi cells. The assay provides a useful alternative to detection of H-Y in the complement-dependent cytotoxicity test.

H-Y antibodies recognize the H-Y transplantation antigen

The question is raised whether the H-Y transplantation antigen, as defined by skin graft rejection, is the same as the "male-specific" antigen that is identified by H-Y antibodies. We have addressed that question by injecting female mice of the inbred C57BL/6 strain with serologically defined H-Y antigen, and measuring the response of those female mice to skin grafts from intrastrain male mice. The results of our study indicate that the "two" male antigens are crossreactive or identical.

Folate deaminase and cyclic AMP phosphodiesterase in Dictyostelium discoideum: their regulation by extracellular cyclic AMP and folic acid

Cyclic AMP and folic acid act as chemotactic factors in Dictyostelium discoideum. Both agents, when applied extracellularly, also control cell development from the growth stage to the acquisition of aggregation competence. Cyclic AMP phosphodiesterase and folate deaminase are extracellular enzymes whose activity is regulated during early differentiation of D. discoideum cells. The two enzymes help control the extracellular levels of cyclic AMP and folic acid. The substrates cyclic AMP and folic acid each increase the extracellular activity of folate deaminase as well as phosphodiesterase. The specificity of extracellular phosphodiesterase regulation by cyclic AMP indicates that the effect is mediated by specific cyclic AMP receptors rather than the catalytic site of cell surface phosphodiesterase. To some extent cyclic AMP and folic acid are interchangeable with respect to regulating differentiation and enhancing enzymatic inactivation of intercellular signals. Thus the two extracellular signals may share a common cellular pathway of signal transduction. The regulation of folate deaminase and phosphodiesterase by folic acid does not always parallel the folic acid effects on development. Pulses of folic acid stimulate development of aggregation competence, whereas a continuous flux inhibits. In contrast, either continuous flux or pulses of folic acid increase the deaminase and phosphodiesterase activities.

[A multidisciplinary study of infantile Steinert's syndrome]

The authors studied from several points of view 10 patients suffering from a neo-natal form of Steinert's disease. They analyse the variety of the family histories, of dysembryoplastic symptoms, of neo-natal difficulties and the subsequent impairment of mental development. They could not find any correlation between this latter evolution and the severity of the neurological damage, judged by the mentioned symptoms. They conclude that the mental retardation is proportional to the low quality of the early socio-emotional environment and believe that this hypothesis is confirmed by the fact that maxillo-facial malformations are mocise speech and mimicry in their early childhood.

Processing of adenovirus RNA before release from isolated nuclei

Nuclei isolated from cultured human cells (KB) infected with adenovirus type-2 were used to study events occurring during the adenosine triphosphate-dependent release of viral RNA. When cells were labeled with [(3)H]uridine for 50 min beginning 18 hr after infection, most nuclear viral messenger RNA was in the form of high molecular weight precursors with sedimentation coefficients greater than 28 S. When nuclei were incubated in the presence of ATP and an ATP-generating system, labeled RNA the size of viral mRNA (10-29 S) was released. Cleavage of viral RNA precursor molecules of high molecular weight occurred during incubation of nuclei. The change in size of viral RNA did not require exogenous ATP and occurred before release of RNA from nuclei. This RNA cleavage seems comparable to processing of mRNA in vivo, for discrete viral species were produced. Cleavage was completed after 10 min of incubation but was not the rate-limiting step in the release reaction, which required about 20 min for completion.

Bacteriophage release in a lysogenic strain of Agrobacterium tumefaciens

Bacteriophage release in a lysogenic strain of Agrobacterium tumefaciens V-1 is temperature-sensitive. At 25 C and 30 C, phage was released in a ratio of 1 plaque-forming unit per 100 bacteria; at 35 C, although bacterial growth was not inhibited, phage release was suppressed. Phage synthesis was induced by heat shock, 42 C for 30 min, ultraviolet irradiation, and mitomycin C. Induction by ultraviolet light was unusual-an immediate rise in phage titer followed irradiation. A large increase occurred after a 90-min latent period. The lysogenic strain was cured of the phage by incubation at 37 C, and the cured strain produced plant tumors.

Isoprene and Rubber. Part 30. Hydromethylrubber

When rubber is reduced at 270° under high pressure, a hemi-colloidal hydrorubber is obtained, and it was proved by Geiger and Huber that the product has a higher molecular weight and is less cyclicized if a good catalyst is used in large quantity (for example, active nickel produced by the method of Kelber), while according to the original experiments of Fritschi, who carried out the hydrogenation in the presence of very little platinum, a more degraded and somewhat cyclicized hydrorubber is obtained. The saturated hydrorubber is much more stable than the unsaturated rubber since the loosening action of the double bonds is lacking. A hydrorubber of the average molecular weight of 10,000 is still relatively stable at 270°, while a hemi-colloidal rubber with this molecular weight will he cracked to still smaller fragments at this temperature, and these fragments are then changed by cyclicization. This behavior can be clearly seen in methylrubber. The following reduction proves that it is even more easily decomposed than rubber itself. With nickel as catalyst, Geiger obtained from methylrubber by reduction at 270° and 100 atmospheres a hemi-colloidal hydromethylrubber which had an average molecular weight of 1600 and therefore had a degree of polymerization of about 20. If rubber is reduced under the same conditions a higher molecular product is obtained with an average molecular weight of 3000 to 10,000. Judged by reduction experiments, the chain of butadiene rubber is still more stable, since the hydrobutadiene rubber prepared under the same conditions had the highest average molecular weight. The cleavage of the chains, as in the following formula, is therefore favored by the methyl groups: