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31.
From Dec 23, 1978, through Jan 31, 1979, an outbreak of five laboratory-confirmed cases and four clinical cases of measles occurred in a Vietnamese refugee population living in a single housing complex in Albuquerque, NM. The index cases were in two refugee siblings in whom measles was incubating on arrival in the United States. Despite spread through three subsequent generations of disease transmission within the Vietnamese population, there was no additional spread into the general Albuquerque population. Responsible factors included the age distribution of susceptible persons, the social isolation of the refugee population, and the physical structure of the housing complex. There is a need to identify the problem of imported measles in "ethnic islands" in need of vaccination.  相似文献   
32.
The amino acid sequence of the alpha-chain of the principal haemoglobin from the shark, H. portusjacksoni has been determined. The chain has 148 residues and is acetylated at the amino terminal. The soluble peptides obtained by tryptic and chymotryptic digestion of the protein or its cyanogen bromide fragments were isolated by gel filtration, paper ionophoresis and paper chromatography. The amino acid sequences were determined by the dansyl-Edman procedure. The insoluble "core" peptide from the tryptic digestion contained 34 residues and required cleavage by several prosteases before the sequence was established. Compared with human alpha-chain there are 88 amino acid differences including the additional seven residues which appear on the amino terminal of the shark chain. There is also one deletion and one insertion. The chain contains no tryptophan but has four cysteinyl residues which is the highest number of such residues recorded for a vertebrate globin. In the alpha1beta1 contact sites there are four changes in the oxyhaemoglobin form and six deoxy form. Nine of the 16, alpha1beta1 contact sites show variation while three of the haem contact sites have changed in comparison to the residues known to be involved in these interactions in horse haemoglobin alpha-chain. Use of the sequence data to estimate a time of divergence of the shark from the main vertebrate line yielded the value of 410 +/- 46 million years. The data, in general, support the palaeontological view that bony fishes arose before the elasmobranchs.  相似文献   
33.
The relationship of education to both actual blood pressure and the prevalence of high blood pressure, based on a systolic pressure of 160 mm Hg or greater or a diastolic pressure of 95 mm Hg or greater, was analyzed among 27,033 men and women, white and black, age 25-44 and 45-64, from the Chicago Heart Association Detection Project in Industry. The educational status of each individual was categorized as not a high school graduate, high school graduate, some college, or college graduate. A statistically significant inverse association between education and high blood pressure was present in all groups of whites. This association could not be "accounted for" by differences in age, relative weight, and heart rate among the educational strata. Controlling for these variables did, however, lessen the association. Among black males a significant inverse association between education level and blood pressure was found for the younger group. For the older black males there was a clear inverse association although with the small numbers it did not achieve statistical significance. For black females there was no clear association.  相似文献   
34.
Halothane positive pigs (24) were placed on water treatments containing sodium bicarbonate (BC, 12.6 g/L), ammonium chloride (AC, 8 g/L) or no additive for 4 days and slaughtered. Halothane negative pigs (8) also were slaughtered. Loin roasts were aged for periods of 1 or 7 days. Loin roasts from animals treated with AC were scored (P<0.05) less firm, juicy, more tender and mealy than roasts from other halothane positive and halothane negative animals. No difference in sensory properties occurred with aging. Juiciness and off-flavor intensity were positively related to blood bicarbonate and base excess.  相似文献   
35.
To gain insight into the factors controlling the maintenance or loss of T cell self tolerance we produced beef insulin (BI)-transgenic BALB/c mice. Transgenic mice express BI under control of the human insulin promoter and secrete physiological amounts of beef insulin. Although these mice are tolerant to BI, as evidenced by the lack of insulin-specific IgG antibody production following intraperitoneal immunization, tolerance is not complete. Footpad immunization results in a weak antigen-specific T cell proliferative response, indicating the presence of self-reactive BI-specific T cell in the periphery. These T cells are functional in vivo, providing support for IgG1, IgG2a, and IgG2b BI-specific antibody production, but require higher higher concentrations of antigen than nontransgenic T cells (both in vivo and following recall responses in vitro) to become activated. In vitro, BI-specific T cell proliferation in BI-transgenic mice can be largely restored by addition of interleukin-2, indicating that a significant component of T cell tolerance is mediated by anergy. To characterize the autoreactive T cells that become activated when tolerance is broken, BI-specific T cell hybridomas were generated from transgenic mice and compared to a panel of hybridomas previously derived from nontransgenic BALB/c mice. The majority of BI-transgenic hybridomas recognized the immunodominant A1-14 beef insulin peptide but with lower avidity than BALB/c hybridomas. Consistent with this, none of the dominant T cell receptor rearrangements found in the BALB/c BI-specific T cell receptor repertoire were found in the transgenic hybridomas. These results indicate that, despite evidence for clonal inactivation of many BI-specific T cells in BI-transgenic mice, loss of tolerance results from activation of low-affinity antigen-specific T cells that appear to have escaped this process.  相似文献   
36.
Corynebacterium urealyticum is usually resistant to multiple antibiotics. We analyzed whether previous hospitalization and/or the use of antibiotics was a factor associated with the appearance of resistance to different antibiotics in C. urealyticum. Our findings suggest that resistant strains of C. urealyticum are likely to be acquired directly from the hospital environment and that the use of antibiotics in the hospital setting could favor the appearance of multiresistant strains.  相似文献   
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The safety and immunogenicity of purified fusion protein (PFP-2) respiratory syncytial virus (RSV) vaccine was evaluated in a randomized placebo-controlled, double-blind study of 64 healthy adults over age 60. Vaccination was well tolerated with no significant acute side-effects. Twenty-nine of 33 vaccinees (87%) showed a greater than or equal to fourfold rise in serum IgG to the F protein of RSV at 8 weeks post vaccination. Twenty of 33 vaccine recipients (61%) had a greater than or equal to fourfold rise in serum neutralizing titer to group A and/or group B RSV. Response to vaccination was inversely correlated with pre-immunization serum neutralizing titers. Active surveillance throughout the ensuring winter identified three RSV infections in the placebo group and none in the vaccine group. Thus, PFP-2 was found to be safe and immunogenic in healthy older adults.  相似文献   
40.
HDL cholesterol (HDL-C) levels are inversely related to coronary heart disease (CHD) risk, and HDL-C distributions vary among countries. Poland is one of the few developed countries in which CHD rates are increasing at the same time that US rates have been falling, but whether these differences are explained by differences in risk factors such as HDL-C has not been determined. To examine this possibility, levels of HDL-C and its subfractions were compared in US and Polish urban and rural men and women aged 45 to 64 years. Age-adjusted HDL-C means were 0.20 mmol/L higher in urban Polish men and 0.37 mmol/L higher in rural Polish men than in their US counterparts (P < .0001); means in urban Polish women were 0.06 mmol/L higher (P < .05) and in rural Polish women 0.09 mmol/L higher (P < .001) than in their US counterparts. Adjustment for age, education, alcohol intake, smoking, BMI, heart rate, and menopause status (in women) had little effect on differences. Means of HDL2 and HDL3 levels showed similar between-country differences, although differences were minimal for HDL2 in urban men and women, and HDL3 means did not differ between rural women. BMI was inversely related to HDL-C and both subfractions in all gender-country-site strata (P < .001), and alcohol was directly related to HDL-C (P < .001) in all strata except Polish women. Cigarette smoking was negatively related to HDL-C and both subfractions in all US samples except HDL2 in urban men, whereas in Polish samples, significant associations were found only in urban women for HDL-C and in rural and urban women for HDL3. Age, heart rate, and education showed inconsistent or no association with HDL-C and its subfractions in either country. This profile of HDL-C and its subfractions in Polish samples contrasts sharply with the opposite trend in CHD mortality rates, which suggests either that other risk factors may account for the trends or that the relationship between HDL-C and CHD may differ between the two countries.  相似文献   
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