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1.
超级传播者(super spreaders)是在短时期内感染10人以上的传染病患者,受感染的多为患者的家属、医务工作者或其他密切接触者。大多数传染病暴发流行中都存在超级传播者,他们能特别高效地将病原传染给其他未曾暴露的个体并使其建立感染。因此,早期发现、及时诊断和严格管理超级传播者对于传染病的防控非常重要。本文就认识超级传播者的重要性、超级传播者的形成及对其的鉴定和干预作简要综述。  相似文献   

2.
Iu P Ksenofontov 《Genetika》1978,14(2):359-364
In the course of studying patients affected with arthritic diseases (bronchial asthma, sugar diabetes) a relationship between those diseases and the blood groups of the Hp and MN systems was established. Patients with bronchial asthma more frequently than in the controls belonged to the Hp 2-2 type and to blood groups MN and O (I), whereas the patients affected with sugar diabetes are usually of the Hp 2-1 type and belong to the belong to the blood groups MN and A(II). The investigation of patients affected with other diseases having a pathogenesis similar to that of bronchial asthma or of diabetes and the observation of healthy persons after prophylactic inoculations as well as the study of sugar metabolism in healthy persons all confirm the relationship of Hp, MN and ABO antigens with arthritic diseases.  相似文献   

3.
We have quantitatively documented the development of sex differences in the behavior of juvenile Japanese macaques (1 to 2 years of age). Mothers treated their offspring differently by sex, i.e., mothers of males broke contact with them more frequently than did mothers of females. Juvenile males played more, and mounted other macaques more frequently; juvenile females groomed their mothers more and were also punished by other group members more frequently than were males. Males showed a pattern of decreasing interactions with their mothers, but females increased the frequency of their maternal interactions. These patterns appear to presage the life histories of the sexes. However, comparisons with other species of nonhuman primates indicate that although sex differences in behavior are common, the variability among species severely limits cross-specific generalizations.  相似文献   

4.
Being male or female is an important determinant of risks for certain diseases, patterns of illness and life expectancy. Although differences in risks for and prognoses of several diseases have been well documented, sex-based differences in responses to pharmaceutical treatments and accompanying risks of adverse events are less clear. The objective of this umbrella review was to determine whether clinically relevant differences in efficacy and safety of commonly prescribed medications exist between men and women. We retrieved all available systematic reviews of the Oregon Drug Effectiveness Review Project published before January 2010. Two persons independently reviewed each report to identify relevant studies. We dually abstracted data from the original publications into standardized forms. We synthesized the available evidence for each drug class and rated its quality applying the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. Findings, based on 59 studies and data of more than 250,000 patients suggested that for the majority of drugs no substantial differences in efficacy and safety exist between men and women. Some clinically important exceptions, however, were apparent: women experienced substantially lower response rates with newer antiemetics than men (45% vs. 58%; relative risk 1.49, 95% confidence interval 1.35–1.64); men had higher rates of sexual dysfunction than women while on paroxetine for major depressive disorder; women discontinued lovastatin more frequently than men because of adverse events. Overall, for the majority of drugs sex does not appear to be a factor that has to be taken into consideration when choosing a drug treatment. The available body of evidence, however, was limited in quality and quantity, confining the range and certainty of our conclusions.  相似文献   

5.
The results obtained in the study of the characteristic features of the spread of viral hepatitis B under the conditions of family foci are presented. Children with viral hepatitis B have been found to infect 4-5 persons per 1,000 contacts, while adults infect not more than 1 person per 1,000 contacts. The results of the study have led to the conclusion that the idea of the potential danger of hepatitis B patients as the source of infection depends on the forms of the infectious process taken into account in evaluating its epidemiological significance. Latent cases of hepatitis B virus infection appear more frequently among the contacts of sick children than among those of sick adults, but the manifest forms of the disease are more frequently caused by infection contacted from sick adults.  相似文献   

6.
doi: 10.1111/j.1741‐2358.2009.00355.x
How primary health care professionals and residents assess issues related to the oral health of older persons? Background and objectives: It is known that older persons need integrated primary health care. However, oral health may not be a frequent concern of multi‐professional teams taking care of older persons. The aim of the present study was to evaluate knowledge and practices related to oral health care, as reported by professionals and residents in a primary health care service. Material and methods: One hundred and seventy‐three health professionals and residents were assessed in this cross‐sectional study by means of a structured questionnaire containing questions pertaining to oral health practices and beliefs. Participants were grouped based on their professions into “primary health care dentists” or “other primary health care professionals” and based on their working status into “permanent team” or “residents”. Results: Permanent team members (other professionals) assessed and recommended dental care more frequently than residents. Permanent team members (other professionals) also reported that they felt they were able to inform older patients in respect to oral health‐related issues more frequently than did residents (68.7% vs. 31.3%, respectively). Conclusion: Oral health‐related knowledge and beliefs were frequent among non‐dentists primary health care workers, suggesting that primary health care which integrates oral health represents an attainable goal.  相似文献   

7.
In a captive group of long-tailed macaques, tool-using behavior by a single competent individual had a significant effect on the synchronous manipulative behavior of naïve animals. Group members engaged in manipulations on the same object class more frequently during times when the model was working than when it was not. The form of their behavior, however, in no way resembled the technique used by the model. All three animals that later became successful tool users were among the few subjects that exhibited a significant increase in manipulations on the same object class while the model was working. Possible causal relationships between this stimulus enhancement and the transmission of the new behavior to other group members are analyzed and discussed.  相似文献   

8.
Observations carried out during 1973-1979 indicate that persons, who are frequently ill, determine the incidence of influenza and acute respiratory diseases among various groups of adult population at all epidemic periods. In constantly observed groups of different ages such persons were the source of 60-85% of the outbreaks of acute respiratory diseases. The correlation between genotypic blood markers (the ABO and HLA systems) and susceptibility to respiratory viruses has been established.  相似文献   

9.
Sequential staining for G- and C-banding of acrocentric chromosomes of 8 persons showed that the large heterochromatin region occurred more frequently in chromosome 15 than in chromosomes 13 and 14, and in chromosome 22 more frequently than in chromosome 21. There proved to be no correlation between the size of the heterochromatic region and the short arm of the acrocentric chromosomes. The frequency of occurrence of the satellites in the 8 persons was approximately the same for all the acricentric pairs. The C-banded satellite region of the homologous chromosomes is often heteromorphic.  相似文献   

10.
A prospective study was initiated before the expected rubella epidemics in 1964 and 1965 in Los Angeles. Seventy-six families were evaluated by means of rubella complement fixing (cf) antibodies. The cf test, which has notable limitations, was chosen as a serologic test because it was possible to secure repeated samples of sera from all members of the families if venipuncture could be avoided.Definite evidence of clinical or serological rubella occurred in 13 of 399 persons enrolled in 1964, an attack rate of 3.3 percent. Four persons had clinical rubella only, five had clinical disease with seroconversion and four had seroconversion only. The ratio of apparent to unapparent disease was nine to four.There were four key families, each of which had more than one individual with definite clinical or serological evidence of rubella, suggesting that clustering of rubella cases does occur in families having an index case. In these families three types of intra-family spread were demonstrated: (1) all affected members had clinical disease, (2) all those affected had only inapparent disease, and (3) both apparent and inapparent disease in the same family.  相似文献   

11.
Medical-genetic study was carried out in the population of Khorezm province (population size above 200 000 persons). Hereditary pathology was ascertained among families having two or more members affected with chronic non-infectious diseases. 155 families with 348 members affected with hereditary diseases were registered. The most frequent were autosomal recessive diseases (55 nosological forms in 104 families with 271 affected), then followed the autosomal dominant conditions (10 nosological forms in 21 families with 53 affected). The less frequent was X-linked recessive pathology (6 forms in 12 families with 20 affected). The main part of cases of autosomal recessive pathology were found in separate families and were not observed during previous medical-genetic studies in Uzbekistan. Three autosomal recessive conditions are probably new forms of hereditary pathology. The important role of assortative matings in manifestation of rare autosomal recessive genes in Uzbek population is discussed.  相似文献   

12.
The mongoose family, Herpestidae, includes several species that comprise the most social small Carnivora. The small Indian mongooseHerpestes javanicus (E. Geoffroy Saint-Hilaire, 1818), a South Asian species that has been introduced to numerous Caribbean and Pacific islands, has not been reported to show complex sociality. A radio-tracking study conducted on Oahu, Hawaii, revealed that a group of at least 5, and perhaps more than 10, large males in the study area shared a single, large home range during the breeding season. Members of this group spent far more time than expected within 20 m of fellow members. Group members frequently shared dens, sleeping within 50 cm of each other. Females maintained very small, overlapping home ranges inside the male group’s range. Male breeding coalitions have previously been reported in a congeneric species, the slender mongooseHerpestes sanguineus.  相似文献   

13.
A total of 231 persons from the families of 62 children hospitalized in connection with viral hepatitis B were examined for the presence of HBsAg in their blood over a period of 3 years. Simultaneously with countercurrent electrophoresis (CIE) and the gel precipitation (GP) test, the passive hemagglutination (PHA) test and the GP test with sandwich treatment were used in this work. The presence of HBs-antigenemia in the members of the families of children with viral hepatitis confirmed by laboratory methods were found to occur 6.7 times more frequently than in the families of children with HBsAg-negative hepatitis. The use of the PHA test and the GP test with sandwich treatment increased the frequency of the detection of HBsAg 2.5 times in comparison with CIE and the GP test. The data indicating the possibility of children being infected through everyday contacts in families with cases of HBs-antigenemia among their members are presented, but further studies are necessary to make the final decision on this problem.  相似文献   

14.

Background

We set out to describe the risk of hospitalization from heart disease, stroke, and diabetes among persons born in India, all foreign-born persons, and U.S.-born persons residing in New York City.

Methods

We examined billing records of 1,083,817 persons hospitalized in New York City during the year 2000. The zip code of each patient's residence was linked to corresponding data from the 2000 U.S. Census to obtain covariates not present in the billing records. Using logistic models, we evaluated the risk of hospitalization for heart disease, stroke and diabetes by country of origin.

Results

After controlling for covariates, Indian-born persons are at similar risk of hospitalization for heart disease (RR = 1.02, 95% confidence interval 1.02, 1.03), stroke (RR = 1.00, 95% confidence interval, 0.99, 1.01), and diabetes mellitus (RR = 0.96 95% confidence interval 0.94, 0.97) as native-born persons. However, Indian-born persons are more likely to be hospitalized for these diseases than other foreign-born persons. For instance, the risk of hospitalization for heart disease among foreign-born persons is 0.70 (95% confidence interval 0.67, 0.72) and the risk of hospitalization for diabetes is 0.39 (95% confidence interval 0.37, 0.42) relative to native-born persons.

Conclusions

South Asians have considerably lower rates of hospitalization in New York than reported in countries with national health systems. Access may play a role. Clinicians working in immigrant settings should nonetheless maintain a higher vigilance for these conditions among Indian-born persons than among other foreign-born populations.  相似文献   

15.
In a non-epidemic period the carrier rate of meningococci among 60 members of the laboratory staff during a long-term observation period of 1.5 years was 38%.In a children's home only a few children were carriers. The meningococci practically did not spread.In 161 recruits observed for periods of at most eight weeks the percentage of positives was 39.1 on the day of joining up and reached its maximum of 80.1 in the course of the period of observation.Among the strains isolated from patients and from carriers, type B predominated. In patients, type C was second in frequency; in carriers, type Y. Type A was found very rarely in carriers and somewhat more frequently in patients.The high carrier rate of type B in adults, together with its low aggressiveness for persons older than ten, may explain the relatively high frequency of the disease in the younger age groups.  相似文献   

16.
The comparative study of the incidence of the pathogenicity markers (DNAase, RNAase, phosphatase and hemolytic activity) in shigellae and salmonellae, acknowledged as the causative agents of intestinal infections, and in opportunistic bacteria isolated from the feces of patients with acute intestinal diseases and healthy persons has been made. The study has revealed that DNAase and RNAase activity occurs most frequently in Shigella flexneri, in salmonellae and in opportunistic enterobacteria isolated from the intestinal contents of patients with acute intestinal diseases. In this respect they essentially differ from the same species of opportunistic enterobacteria isolated from healthy persons.  相似文献   

17.
Horizontal gene transfer (HGT) is thought to be an important driving force for microbial evolution and niche adaptation and has been show in vitro to occur frequently in biofilm communities. However, the extent to which HGT takes place and what functions are being transferred in more complex and natural biofilm systems remains largely unknown. To address this issue, we investigated here HGT and enrichment of gene functions in the biofilm community of the common kelp (macroalgae) Ecklonia radiata in comparison to microbial communities in the surrounding seawater. We found that HGTs in the macroalgal biofilms were dominated by transfers between bacterial members of the same class or order and frequently involved genes for nutrient transport, sugar and phlorotannin degradation as well as stress responses, all functions that would be considered beneficial for bacteria living in this particular niche. HGT did not appear to be driven by mobile gene elements, indicating rather an involvement of unspecific DNA uptake (e.g. natural transformation). There was also a low overlap between the gene functions subject to HGT and those enriched in the biofilm community in comparison to planktonic community members. This indicates that much of the functionality required for bacteria to live in an E. radiata biofilm might be derived from vertical or environmental transmissions of symbionts. This study enhances our understanding of the relative role of evolutionary and ecological processes in driving community assembly and genomic diversity of biofilm communities.Subject terms: Biofilms, Metagenomics  相似文献   

18.
Divergence and differential expression of soybean actin genes   总被引:17,自引:2,他引:15       下载免费PDF全文
DNA sequence analysis as well as genomic blotting experiments using cloned soybean actin DNA sequences as probes show that large sequence heterogeneity exists among members of the soybean actin multigene family. This heterogeneity suggested that the members of this family might be diverged in function and/or regulation. Five of the six soybean actin gene family members examined are shown to be significantly more diverged from one another than members of other known actin gene families. This high level of divergence was utilized in the preparation of actin gene-specific probes in the analysis of the complexity and expression of these members of the soybean actin gene family. Hybridization studies indicate that the six soybean actin genes fall into three classes with a pair of genes in each class. These six genes account for all but two actin gene fragments detected in the soybean genome. We have compared the relative steady state mRNA levels of these classes of soybean actin genes in three organs of soybean. We find that actin genes SAc6 and SAc7 are most highly expressed accounting for 80% of all actin mRNA with respect to the six soybean actin genes examined. Actin genes SAc3 and SAc1 are expressed at intermediate and low levels respectively; and SAc2 and SAc4 are expressed at barely detectable levels. Four of the six soybean actin genes appear to be expressed at the same level in root, shoot and hypocotyl. SAc3 and SAc7 genes appear to be more highly expressed in shoot and 2,4-dichlorophenoxyacetic acid-induced hypocotyl than in root and hypocotyl.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

19.
A total of 708 healthy persons in Tajikistan and 576 healthy persons in Azerbaijan, these groups comprising persons of both sexes and different age groups, were examined by the method of double gel immunodiffusion (the gel precipitation test) and by the passive hemagglutination test for the presence of the markers of hepatitis B virus (HBV) infection (HBsAg and HBeAg) and antibodies to them. This investigation showed that, in accordance with the level of hepatitis B morbidity, HBsAg was significantly more often detected among the population in Tajikistan (7.2%) than in Azerbaijan (2.8%). In both republics HBV carriers occurred most frequently among children aged 1-4 years (4.0% in Azerbaijan and 13.9% in Tajikistan), and among men more frequently than among women. In accordance with different intensity of the spread of HBV infection in the territories under comparison, differences in the age structure of the immune population were noted: in Tajikistan the formation of the immune layer occurred most frequently among younger age groups and in Azerbaijan, among senior adult age groups. The presence of a considerable percentage of persons with HBe-antigenemia (14.3-14.9% as determined by the gel precipitation test) among HBV carriers, observed in Tajikistan and in Azerbaijan, indicates that some of them have undetected chronic hepatitis B.  相似文献   

20.

Background

Persons affected by neurofibromatosis type 1 (NF1) have a decreased survival, yet information on NF1-associated mortality is limited.

Methods/Aim

The National Mortality Database and individual Multiple-Causes-of-Death records were used to estimate NF1-associated mortality in Italy in the period 1995-2006, to compare the distribution of age at death (as a proxy of survival) to that of the general population and to evaluate the relation between NF1 and other medical conditions by determining whether the distribution of underlying causes of NF1-associated deaths differs from that of general population.

Results

Of the nearly 6.75 million deaths in the study period, 632 had a diagnosis of NF1, yet for nearly three-fourths of them the underlying cause was not coded as neurofibromatosis. The age distribution showed that NF1-associated deaths also occurred among the elderly, though mortality in early ages was high. The mean age for NF1-associated death was approximately 20 years lower than that for the general population. The gender differential may suggest that women are affected by more severe NF1-related complications, or they may simply reflect a greater tendency for NF1 to be reported on the death certificates of young women. Regarding the relation with other medical conditions, we found an excess, as the underlying cause of death, for malignant neoplasm of connective and other soft tissue and brain, but not for other sites. We also found an excess for obstructive chronic bronchitis and musculoskeletal system diseases among elderly persons.

Conclusion

This is the first nationally representative population-based study on NF1-associated mortality in Italy. It stresses the importance of the Multiple-Causes-of-Death Database in providing a more complete picture of mortality for conditions that are frequently not recorded as the underlying cause of death, or to study complex chronic diseases or diseases that have no specific International Classification of Diseases code, such as NF1. It also highlights the usefulness of already available data when a surveillance system is not fully operational.  相似文献   

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