Comparison of counterimmunoelectrophoresis (CIE), latex agglutination (LA) and staphylococcal coagglutination (COAG) in pneumococcal antigen detection in vitro

CIE was compared to agglutination assays employing commercial kits (Directigen, Phadebact), as well as our own LA and COAG reagents, in detection of pneumococcal capsular polysaccharide (PCP) antigens in vitro. Directigen provided the most sensitive assay. CIE was of comparable sensitivity except for PCP antigen types 7 and 14.     

Androstenedione or corticosterone treatment during pregnancy alters estrous cycle of adult female offspring in mice

Female offspring from mice injected with androstenedione during late pregnancy showed lengthened vaginal cycles, persistent estrus and decreased incidence of pro-estrus and diestrus, whilst offspring from mice injected with corticosterone showed increased incidence of diestrus. These observations give qualified support to the hypothesis that stress during pregnancy alters the female offspring reproductive system through the action of adrenal steroids.     

Abnormal development of phialides in a strain ofAspergillus niger

Summary AnAspergillus niger mutant strain (hpp) produces an average of 4.1% of conidiophores with phialide proliferations. Increased frequency of proliferations could be induced on all studied strains by growth on potato dextrose agar. The characteristic is recessive and seems to be due to a pleiotropic effect of the mutation for olive conidia color.Acknowledgments. The authors are indebted to CNPq for financial assistance provided with grant PIG/SIP 04/053 as well as the scholarships Pesquisador Científico (R.B.Jr) and Iniciação Científica and Aperfeiçoamento (G.U.V.).     

Morphological transformation in vivo of human uterine cervix with papillomavirus from condylomata acuminata

Carcinoma of the human uterine cervix has been associated with several infectious agents including papillomavirus. Papillomavirus group-specific antigen (GSA) and viral particles have been demonstrated in human condylomata acuminata (CA) and flat warts of the uterine cervix. Cell alterations consisting of nuclear enlargement, hyperchromasia, irregularity, binucleation and cytoplasmic clearing (koilocytosis) are often interpreted as mild to moderate dysplasia. Present evidence that human papillomavirus (HPV) is responsible for the development of these lesions relies on the association of GSA and virus particles in the affected tissue, fulfilling the first two of Koch's postulates. Direct proof of an aetiological relationship, however, requires induction of the CA change in normal, human uterine cervix after exposure to papillomavirus. Infecting human subjects with HPV is ethically unacceptable and no satisfactory alternative systems have been defined. Also, human cell cultures do not support growth or transformation by HPV. Here we report the first demonstration of the morphological transformation of human tissues with a human papillomavirus under controlled, experimental conditions. 'Transformation' is used here in its literal sense to refer to a heritable morphological alteration in the appearance of the cells. The use of this term does not indicate that the changes described are neoplastic, but they are identical to the dysplastic changes found in biopsies of uterine cervical CA. Our results demonstrate the direct involvement of CA virus in dysplastic change of human cervical tissue and indicate that the experimental system described may be useful in elucidating the contribution of human papillomaviruses to the pathogenesis of human cervical cancer.     

An HTLV-III peptide produced by recombinant DNA is immunoreactive with sera from patients with AIDS

Human T-cell lymphotropic retrovirus type III (HTLV-III), also called lymphadenopathy-associated virus (LAV), has been identified as the aetiological agent of acquired immune deficiency syndrome (AIDS). The sera of most patients with AIDS or AIDS-related complexes, and of asymptomatic individuals infected with HTLV-III, contain antibodies against antigens of HTLV-III. The characterization of these antibodies and their corresponding viral antigens is important not only for understanding immunity against HTLV-III and the pathology of AIDS, but also for the development of diagnostic methods and preventive vaccine for AIDS. Following the successful establishment of a long-term T-cell line permissive for HTLV-III replication, large quantities of virus have been produced, facilitating the purification of viral proteins and the development of mouse monoclonal antibodies against several viral antigens. More recently, the structure of HTLV-III proviral DNA has been elucidated. We now report the production, by genetic engineering methods, of a peptide encoded by a gene segment of HTLV-III. A 1.1-kilobase (kb) EcoRI DNA segment from an isolate of HTLV-III was inserted into a lpp and lac promoter-coupled expression vector, pIN-III-ompA. Escherichia coli transformants of this plasmid produced a peptide of relative molecular mass (Mr) 15,000 (15K) which was strongly immunoreactive with anti-HTLV-III antibodies present in sera from AIDS patients. Lysates of the clones expressing this 15K peptide inhibited the reactivity of the p31 virion protein with AIDS sera, suggesting that it is a fragment of the viral p31 protein. The peptide reacted with sera from all 20 AIDS patients but none of the 8 normal controls tested. These results suggest that the peptide may be useful for detecting anti-HTLV-III antibodies in blood samples.     

MATHEMATICAL MEASURES OF SHAPE CONFORMITY

This paper has developed a single mathematical measure for the evaluation of the shape conformity of the curved garment objects such as moulded brassiere cups. The measurements are based on the sectional analysis of the fringe pattern generated by means of moire topography. They include the area ratio, shape ratio and root mean square (RMS) of the height deviation of the moulded cup from the standard shape profile. Ultimately, the RMS was found to be a satisfactory method of assessing the shape conformity and a guideline for determining a good fit from the RMS value was then derived.     

Radiation carcinogenesis in experimental animals

Exposure of man to relatively high doses of ionizing radiation is generally restricted to accidental situations, with very limited knowledge about the actual doses received. Animal experiments can be performed under standardized and controlled conditions and can provide information on the dose-response relationships for radiation carcinogenesis. The risk of inducing neoplastic late effects after total-body irradiation with relatively high doses has been demonstrated for larger animals, such as monkeys and dogs. The bone marrow, the mammary glands and the lungs are among the tissues with the highest susceptibility for radiation carcinogenesis. Experimental results on tumour induction in rodents are summarized with emphasis on the effectiveness in dependence on radiation quality and fractionation or dose rate.     

Further evidence for the existence of a bottleneck in the metabolism of Saccharomyces cerevisiae

The growth physiology of Saccharomyces cerevisiae strains H1022 and Whi2+ has been studied in aerobic batch and continuous (chemostat) cultures. Results from the measurement of biomass and medium components (off-line) together with oxygen, carbon dioxide and heat measurements (on-line) have been used in an attempt to explore the existence of 'overflow' or 'bottleneck' metabolism as opposed to catabolite repression (Crabtree effect) in these strains. Chemostat experiments indicated that specific oxygen uptake rate (qO2) was linearly related to the dilution rate (D) at values below the critical dilution rate (D crit), becoming constant above D crit, which is in agreement with the bottleneck theory. However, batch culture experiments indicated negligible oxygen consumption during the initial glucose growth phase, the culture exhibiting purely anaerobic metabolism. The bottleneck theory would propose that qO2 has a constant (maximum) value under these conditions. The results presented here suggest that while the bottleneck theory can be adequately used to describe chemostat growth of S. cerevisiae, some other control mechanism must be operating under conditions of high glucose concentrations, such as those initially prevailing in the batch culture experiments.     

火灾报警系统的研究

介绍了火灾报警系统的硬件设置与软件设计原理，讨论了该系统安装调试过程中的有关技术问题，阐述了对该系统进行的模拟联动试验，证明该系统的技术是先进的，工作是可靠的，每个工作环节都准确无误。