Standardisation of 31phosphorus-nuclear magnetic resonance spectroscopy determinations of high energy phosphates in humans

A procedure is described for standardising the determination of adenosine 5-triphosphate and phosphocreatine concentration ([ATP] and [PC], respectively, in absolute arbitrary units) in human muscle by nuclear magnetic resonance (NMR) spectroscopy. The individual ³¹phosphorus (²¹P)-NMR spectra obtained on equal hemispherical tissue volumes (muscle plus skin and fat) were corrected for the thickness of the skin and of the subcutaneous fat. The volumes investigated were standardised using an external reference. The procedure described made possible the comparison of high energy phosphate concentrations among different subjects. It was applied to the assessment of [ATP] and [PC] in four groups of sedentary subjects (children, and adults aged 20–35, 35–50 and over 50 years), and in a group of athletes (volleyball players). The [ATP] and [PC] were not statistically different in the groups investigated.     

Distribution of TT virus genomic groups 1-5 in Brazilian blood donors, HBV carriers, and HIV-1-infected patients

Human isolates of the highly prevalent TT virus (TTV) have been classified into five major genomic groups (1-5). The geographical distribution of the groups throughout the world is not well known. Five different PCR assays were developed in an attempt to amplify specifically TTV DNAs of each genomic group. Serum samples collected from 72 Brazilian adults (24 voluntary blood donors, 24 hepatitis B virus (HBV) carriers, and 24 human immunodeficiency virus type 1 (HIV-1)-infected patients) were tested. TTV DNA from at least one genomic group was detected in 11 (46%) blood donors, 13 (54%) HBV carriers, and 24 (100%) HIV-1 patients. All five genomic groups were detected in the three populations, with the exception of group 2 in blood donors. Some samples, negative with all five specific assays, were positive with the commonly used untranslated region (UTR) PCR system. On the other hand, TTV DNA was detected in some samples by using specific assays but not with the UTR PCR. Mixed infections with 2-5 TTV isolates from different groups were detected in 21% blood donors, 29% HBV carriers, and 71% HIV-1 patients. Fifteen PCR products (three obtained with each assay) were sequenced. Most sequences showed high (>86%) homology with those of TTV isolates belonging to their presumed groups. However, three sequences had low homology with all TTV sequences available from the DNA databanks. In conclusion, TTV isolates belonging to all five known genomic groups circulate in Brazil, and the results suggest the existence of new and as yet uncharacterised major genomic groups.     

A fucose-containing epitope potentially involved in gamete interaction on the human zona pellucida

The oligosaccharide moiety of human, porcine and bovine zonaepellucidae was studied with lectins and monoclonal antibodiesspecific for tri- or tetra-saccharidic epitopes containing atleast one terminal -L-fucose. Animal eggs were collected fromfollicular aspirates, human eggs were collected from in-vitrofertilization and embryo transfer programmes and pooled intosix groups. By direct immunofluorescence, the lectins reactivitywas detected for the animal or the human zonae pools in thesame way. Reactivity of Aleuria aurantia lectin demonstratedthe presence of –L-fucose terminal residues in the zonaefrom the three species studied. By indirect immunofluorescence,the 2–25 antibody reactivity was detected in every poolof human zonae whereas there was no evidence of any antibodyreactivity on animal zonae. Using an anti-Lewis-b blood groupantibody (2–25), we observed expression of this antigenas an intrinsic component of the human zona pellucida, independentlyof patients'Lewis red blood cell phenotypes. Antibody 2–25inhibited the sperm–atozoa-zona binding in a hemizonaassay, suggesting that this fucose-containing antigen couldbe part of a sperm-zona receptor.     

Relationship between lipofuscin granules and polyunsaturated fatty acids in the housefly, Musca domestica

The fractional volume occupied by lipofuscin granules in epithelial cells of the midgut or oenocytes of abdominal fat body of 3-day-old and 13-day-old male houseflies was determined in two groups of flies by electron microscopic morphometry. One group had developed from larvae reared on diets containing no added polyunsaturated fatty acids and the second from larvae reared on diets containing added linoleic acid. No polyunsaturated fatty acids could be detected in the lipids of the first group of flies using a method which would have detected their presence in amounts greater than 0.1% of the total esterified fatty acids. The second group contained at least two hundred times more than this minimal level. The volume of lipofuscin granules increased significantly (p less than 0.01) (about threefold for the fat body and twofold in midgut cells) between 3 days and 13 days of age but no statistically significant difference was seen between the two groups of flies at the same age. The results show that if lipofuscin formation depends on the oxidation of polyunsaturated fatty acids in the housefly, then extremely small amounts of the acids are involved which lie below the detection limit of the methods employed. The age-associated small increase of extractable fluorescence seen previously in the linoleic acid group of flies is not associated with an increase in the lipofuscin granules.     

Sex- and age-related blood pressure response to dynamic work with small muscle masses

Summary Four groups of subjects of different ages and sex (group I: 20–29 years, women; group II: 20–29 years, men; group III: 30–39 years, women; group IV: 30–39 years, men) undertook dynamic one-hand work (load range 40%–80% of maximum voluntary contraction, at 60 working cycles/min) to allow a study of cardiovascular responses as shown by the resultant changes in blood pressure and heart rate. During fatiguing dynamic one-hand work, there was a large increase in systolic and diastolic blood pressures in both sexes after a few minutes. For all load levels, the systolic blood pressure was found to be higher by about 4 kPa in men (groups II and IV) than in women (groups I and III). Other age-related differences became evident in the diastolic blood pressure changes. The values obtained for the older groups were higher than those in the two younger groups. These differences in blood pressure response are possibly due to sex-related differences in the release of catecholamines, or to age-related organic changes in the vessels.     

HLA class I in three West African ethnic groups: genetic distances from sub-Saharan and Caucasoid populations

Fulani of Burkina Faso (West Africa) are a particularly interesting ethnic group because of their lower susceptibility to Plasmodium falciparum malaria as compared to sympatric populations, Mossi and Rimaibé. Moreover, the occurrence of a Caucasoid component in their genetic make-up has been suggested on the basis of their physical traits and cultural traditions even though this view was not supported by genetic studies. A total of 149 unrelated subjects (53 Mossi, 47 Rimaibé and 49 Fulani) have been typed for 97 HLA class I alleles with the amplification refractory mutation system/polymerase chain reaction (ARMS/PCR) technique. Mossi and Rimaibé data were pooled since none of the 42 statistically testable alleles exhibited a significant heterogeneity. These pooled gene frequencies were found to be very different from those of Fulani: a certain (P<0.001) or a likely (0.001 相似文献   

The effect of 2,3-dimercaptopropane sodium sulfonate on mercury retention in rats in relation to age

The effectiveness of DMPS (sodium 2,3-dimercaptopropane-1-sulfonate) in reducing inorganic mercury retention was studied in 2-, 6-, and 28-week-old albino rats. ²⁰³Hg was administered IP. The chelating agent DMPS was administered by IP injection at a dose of 250 mol/kg body weight three times, 1 day after ²⁰³Hg administration and at 24 h intervals thereafter. The whole body retention determined 1, 2, 3, and 6 days after ²⁰³Hg administration showed that DMPS decreased the body retention of mercury in all age groups, being about twice as effective in adult compared to suckling rats. The reduced effectiveness was due to the reduced efficacy of DMPS in reducing kidney retention in young animals. In other organs the effectiveness of DMPS was not age dependent. These and previous results obtained with different chelating agents and other metals indicate that age might be an important factor in chelation therapy in general.     

Influence of exposure mode on vinyl chloride action

Rats were subjected to 4 h continuous or intermittent exposure to vinyl chloride (VC) at different time-weighted average concentrations (15, 50, 150, 500 and 15,000 mg/m³). Hepatic non-protein sulfhydryl content (NPSH) and excretion of thiodiglycolic acid (TdGA) in urine were determined. VC at concentrations from 50 mg/m³ to 15,000 mg/m³ caused a dose-dependent depression of NPSH, but no difference in the magnitude of this depression induced by continuous or intermittent exposure at the same average concentration of VC was noted. At average concentrations of 50 mg/m³ and 150 mg/m³, the urinary excretion of TdGA under continuous exposure did not differ from that under intermittent exposure, whereas at VC concentrations of 500 mg/m³ and 15,000 mg/m³ it was higher following continuous exposure.     

A qualitative exploration of the mechanisms,pathways and public health outcomes of a city centre 20mph speed limit intervention: The case of Belfast,United Kingdom

Twenty miles per hour (mph) speed limits can impact the health of the public (e.g., road safety, active travel). However, a better understanding of how individuals experience 20mph limits is required, to ensure interventions are cognisant of perceptions and potential un/intended outcomes. Focus groups (n = 9, 60 participants) to explore the Belfast 20mph intervention highlighted divergent perspectives and experiences including: 12 mechanisms (e.g., limited awareness), 15 pathways (e.g., reduced driving speed→improved liveability) and 10 public health outcomes (e.g., increased cyclist safety). Future interventions should consider un/intended outcomes and implement strategies to enhance effectiveness and mitigate harms (e.g., through training, enforcement).     

广西壮族人群血清HBsAg阳性与 ABO血型相关性研究

目的 探讨广西壮族人群血清HBsAg与ABO血型分布之关系。方法 采用卡方（x^2）检验方法与Woolf统计方法对578例HBsAg阳性携带者血清的ABO血型分布及男女性别的关系进行系统分析。结果 男性携带者血型呈O＞B＞A＞AB型分布,女性携带者呈O＞A＞B＞AB型分布。A、B、O和AB血型人相对危险率分别为1．1531、1．0458、0．9238和0．7365。结论：血清HBsAg阳性携带者与ABO血型间存在一定关系且与性别有关,尤以A型血女性感染乙肝病毒的危险性更大,具有重要流行病学意义。