摘要:

SummarySeasonal prevalence and malaria transmission patternsof Anopheles farauti, An. punctulatusandAn. koliensiswere studied in two coastal and two inland villages in the Madang district of northern Papua New Guinea. The monthly manbiting rates (average biting density of vector mosquitoes per man per night) were observed over a two‐year period to establish typical seasonal prevalence patterns. Observations on the frequency of feeding and the human blood index were combined to derive the manbiting habit. A daily survival rate was determined from the dissection of mosquito ovaries by Polovodova's age‐grading method. The extrinsic cycle in the mosquito was not observed, and the value for this parameter was extracted from the literature. All parameters were combined to estimate the monthly variations in vectorial capacity of each of the vector species, and the vectorial capacities of the individual species were added together to give a total monthly vectorial capacity of thepunctulatuscomplex in each locality. The results showed that malaria transmission can be perennial, with a period of more intense transmission between August and January in the southern area, and between September and February in the northern. A period of very low transmission can be expected between February/March and July/August.

ISSN:0004-945X    

DOI:10.1038/icb.1980.1

出版商:Nature Publishing Group    

年代:1980

数据来源: WILEY

摘要:

SummaryThe association between nutrient deficiencies, steroid administration, anti‐flagellate therapy and giardiasis was examined using theGiardia muris/mouse model. Administration of steroids to BALB/c mice resulted in persisting high levels of infection withG. muris, whereas untreated animals were able to eliminate this parasite. In addition, steroid treatment significantly reduced the efficacy of anti‐flagellate therapy. Protein‐deficient mice eliminated the parasite at the same rate as mice on an optimum diet and also developed strong acquired resistance to re‐infection. A similar pattern was observed in iron‐deficient mice, except that the number of parasites that became established during the first 2 weeks of infection was significantly reduced. Thus, there was no evidence of synergism between iron and protein deficiency and infection in this model.

ISSN:0004-945X    

DOI:10.1038/icb.1980.2

出版商:Nature Publishing Group    

年代:1980

数据来源: WILEY

摘要:

SummaryLeukaemic cells from seventeen untreated acute lymphocytic leukaemia (A.L.L.) patients have been typed at presentation with heteroantisera prepared in rabbits by complement mediated cytotoxicity. Reactivity with antisera has suggested a preliminary grouping of patients, in this study, into Null, pre‐T (post‐thymic T‐cell precursor) and T‐cell subtypes. The leukaemic cells have also been classified with the established markers, E‐rosette receptor, surface immunoglobulin and C3receptor as well as total white cell count at presentation.Anti NALM‐1 (Null‐lymphoblastoid cell line) serum reacted with cells from all childhood A.L.L. patients tested but could be made specific for cALL antigen of the common Null form of A.L.L. by further absorption or dilution. Antisera to membrane fractions from cells of high white cell count Null‐A.L.L. patients reacted with cells of these patients as well as T‐A.L.L. patients. Anti MOLT‐4 (adult T‐A.L.L. derived lymphoblastoid cell line) serum reacted only with cells of T‐A.L.L. patients.

ISSN:0004-945X    

DOI:10.1038/icb.1980.3

出版商:Nature Publishing Group    

年代:1980

数据来源: WILEY

摘要:

SummaryAlloantibody was raised in PVG/c rats against DA rats. The catabolism of alloantibody in normal PVG/c rats and PVG/c rats tolerant to DA rats was followed after intravenous injection. A haemagglutination assay was used to detect alloantibody activity. The half‐life time of alloantibody IgG2a in the normal PVG/c rats was 10 days. On the other hand, in the PVG/c rats tolerant to DA rats, the half‐life of alloantibody lgG2a varied. The rats could be divided into three groups. Group A: alloantibody IgG2a was eliminated from the circulation very rapidly. Group B: alloantibody IgG2a disappeared from the circulation relatively rapidly and was maintained at a low level in the plasma but then increased to a high titre. This peculiar pattern of Group B seems to be due to the endogenous production of alloantibody. In this case abrogation of tolerance took place. Group C: the pattern of elimination of this group was almost identical to that of normal rats.The biological significance of the plasma decay of alloantibody IgG2a in the normal and homograft tolerant rats has been considered. It is concluded from the present results that alloantibody might be important in some cases for the maintenance of homograft tolerance.

ISSN:0004-945X    

DOI:10.1038/icb.1980.4

出版商:Nature Publishing Group    

年代:1980

数据来源: WILEY

摘要:

SummaryApparent kinetic constants for NADPH have been calculated for NADPH‐cytochrome P450reductase and demethylase activity in the presence of aminopyrine and ethylmorphine with hepatic microsomal preparations from phenobarbital pre‐treated rats. The presence of NADH changed Kmvalues but not the V values for cytochrome P450reductase. In addition, NADH reduced Kmvalues for demethylase activity and had a biphasic effect on V values; elevating them at high and depressing them at low concentrations. The V values at different NADH concentrations appeared to correlate with the concentration of reduced cytochrome b5that the added NADH could sustain during the incubation period. Tetrahydronicotinamide adenine dinucleotide (NADH3), a structural analogue of NADH, reduced demethylase activity without affecting NADPH‐cytochrome P450reductase activity or the concentration of reduced cytochrome b5. As this analogue cannot reduce biological systems, the depressed V values for demethylation suggest that in the presence of NADH3and NADPH there exists an alternative mechanism for the supply of electrons from NADPH to the partially reduced oxygenated cytochrome P450‐substrate complex.

ISSN:0004-945X    

DOI:10.1038/icb.1980.5

出版商:Nature Publishing Group    

年代:1980

数据来源: WILEY

摘要:

SummaryOne hundred and sixty three isolates of group B streptococci from human carrier and disease conditions in Brisbane, Melbourne and Adelaide were serotyped by the Lancefield capillary precipitin test, coagglutination and microimmunodiffusion. Serotypes I and III were most common; serotype III appeared to occur uniformly but serotype Ia varied in distribution. No significant difference was found in serotype distribution among isolates from pregnant and non‐pregnant women, or rectal and vaginal swabs; however, type Ia was found to occur significantly more often as an infectious agent than as a commensal (P<0.01).

ISSN:0004-945X    

DOI:10.1038/icb.1980.6

出版商:Nature Publishing Group    

年代:1980

数据来源: WILEY

摘要:

SummaryCurrent practices for early warning of activity of Murray Valley encephalitis and other medically‐important arboviruses are reviewed with view to improvement. Data From previous papers onCulex annulirostrispopulations, environmental factors and virus infection rates were reanalysed and the results considered as a basis for prediction and surveillance. This goal will only be achieved with improved national cooperation, a better epidemiological understanding and greater knowledge of the bionomics of the major vector,Culex annuliroslris. The improved monitoring system will utilize meteorological, serological and entomological criteria.

ISSN:0004-945X    

DOI:10.1038/icb.1980.7

出版商:Nature Publishing Group    

年代:1980

数据来源: WILEY

摘要:

SummaryThe natural killer (NK)*cell induced one to two days after Kunjin virus infection of BAI.B/c mice is cytotoxic for a wide range of syngeneic, allogeneic and xenogeneic cell lines. It is also weakly cytotoxic for some non‐malignant cells including mouse fibroblasts, macrophages and thymocytes, but not lymph node cells. Levels of lysis of non‐tumour target cells are dependent on their genotype. Furthermore, malignant cell lines may become resistant following transplantationin vivothen susceptible again after culturein vitro.The virus‐induced NK cell is elicited as readily in athymic (nude) as in normal mice. X‐irradiation inhibits its development if administered prior to infection. It is labile on culture at 37°. The cell carries Fc receptors but its NK activity is not antibody‐dependent.

ISSN:0004-945X    

DOI:10.1038/icb.1980.8

出版商:Nature Publishing Group    

年代:1980

数据来源: WILEY

摘要:

SummaryDuring investigations of epidemic polyarthritis at Nelson Bay, New South Wales, 12 strains of Ross River virus, the causative agent, were recovered from pools of mosquitoes. In addition, the mosquito pools yielded 9 strains of the flavivirus Edge Hill, 4 strains of a bunyavirus, Gan Gan, 1 strain of an orbivirus Tilligerry, and 1 strain of an ungrouped probable arbovirus, Yacaaba. The latter 3 viruses were found to be antigenically distinct from previously recorded arboviruses.A case of epidemic polyarthritis probably contracted at Bawley Point, approximately 400 kilometres south of Nelson Bay on the south coast of New South Wales, is recorded. Mosquitoes collected in the nearby Termeil State Forest one year later yielded a strain of Ross River virus and 5 strains of a previously undescribed ungrouped togavirus, Termeil.The extent of arboviral activity in temperate coastal areas of south‐eastern Australia was unexpected.

ISSN:0004-945X    

DOI:10.1038/icb.1980.9

出版商:Nature Publishing Group    

年代:1980

数据来源: WILEY