[Method of dietary nutritional status assessment and its application in cohort study of nutritional epidemiology].

Minimizing the burden on study subjects and assessing the general dietary nutritional status as accurately as possible are the basis of a nutritional epidemiological cohort study in the general population. While introducing the main dietary nutrition assessment methods, this paper manly describes the basic contents and principles for the development of food frequency questionnaire, and briefly illustrates the problems and solutions for the development of area specific food frequency questionnaires by taking the example of Tianjin Chronic Low-grade Systemic Inflammation and Health (TCLSIH) cohort study. Finally, discusses preliminarily the necessity and possibility of developing a national food frequency questionnaire.

HER2 status in gastric cancers: a retrospective analysis from four Chinese representative clinical centers and assessment of its prognostic significance.

BACKGROUND: HER2 has a predictive value in gastric cancer. However, its association with prognosis remains uncertain. The aim of our study was to estimate the HER2-positive rate in Chinese gastric cancers, compare the classical fluorescence in situ hybridization (FISH) method with the novel bright-field dual color silver-enhanced in situ hybridization (DSISH) detection system, and evaluate the relationship between the HER2 status and prognosis. PATIENTS AND METHODS: Seven hundred and twenty-six resected gastric cancers separately from four clinical centers in China were examined for HER2 by immunohistochemistry (IHC), FISH, and DSISH. RESULTS: The HER2-positive rate was 13%. The consistency between FISH and DSISH results was high (99%; κ = 0.958; P < 0.001). Tumor heterogeneity and polysomy were the main reasons for inconsistency. There was no significant difference in the 3-year overall survival (OS) between HER2-positive and -negative patients (P = 0.959). Multivariate analysis showed that HER2 was not an independent prognostic factor. CONCLUSION(S): HER2 overexpression and amplification occur in a significant number of Chinese gastric cancer patients. Given the obvious advantages and high consistency with FISH, DSISH was superior for evaluating HER2 amplification in gastric cancer. HER2 was not a prognostic factor for gastric cancer in our study.

[A survey on sex knowledge and medical demand of the cases in Kaohsiung city adolescent health clinic].

The purpose of this survey is to study the sex knowledge of adolescents, and to analyze their need in sex consultation and related health problem in Kaohsiung city. A total of 1,000 study subjects were recruited from May 1991 to May 1994. A self-administered questionnaire and medical records were used to obtain related information. The results were as follows: 1. The male to female ratio of study subjects was 1:2. Half of them were students, 44.1% had sexual experience, and the mean +/- standard deviation of age at first sex experience was 19.1 +/- 2.8 years. 2. The average percentage of correct knowledge was as low as 67.6%. It indicated an inadequacy of sex knowledge in adolescents. Females had better knowledge than males. Subjects who had graduated from senior high schools had better knowledge than those graduated from middle schools. No association was found between the score of sex knowledge and occupation. 3. 12.5% of study subjects believed that "masturbation" might cause neurasthenia, kidney malfunction and loss of memory, while 11.9% recognized that "nocturnal emission" might result in abnormal ejaculation, mental aberration and guilty feelings. Furthermore, 3.8% considered that kissing, hugging or sleeping together might cause pregnancy. 4. Most adolescents felt that "guidance on sex knowledge" was the major reason for them to visit the adolescent clinic and "obstetric and gynecological problems" was the second most important. 5. Males and females have the same prevalence of sex experience, and 50.6% of them did not practice contraception. 88.9% subjects had a high risk of getting pregnancy. 6. Males had a higher percentage of more than one heterosexual partner than females did. There was a higher percentage of people with a high education level having a fixed heterosexual partner than that of those with a low education level.

A modeling method to improve quantitation of fluorodeoxyglucose uptake in heterogeneous tumor tissue.

UNLABELLED: The standard approach for evaluating FDG-PET kinetic studies is based upon an assumption that tissue within a representative region of interest (ROI) is relatively homogeneous in terms of FDG kinetics. In neoplasms and other disease states, tissue within an ROI may be grossly heterogeneous, due to adjacent infarcted tissue and other causes. We have developed a method employing two ROIs (one over the tumor and another over a "reference region") to deal with this level of heterogeneity. METHODS: The method is based on the regular FDG model but consists of six variable parameters (6P model) which uses the kinetics in the reference region to account for the normal tissue within the tumor ROI, so that the kinetic data only associated with the tumor can be estimated. Monte Carlo simulations and human PET FDG studies were used to analyze the performance of the 6P model. RESULTS: The narrower 95% confidence intervals of parameter estimates, which centered at the true tumor rate constants, and the smaller correlation matrix of the 6P model showed the better performance of the 6P model compared to the standard "homogeneous" four-parameter FDG model. Computer simulations further showed that the 6P model can accurately estimate the microparameters (rate constants: K1* (ml/min/g), k2* (min-1), k3* (min-1), k4* (min-1)) and the macroparameter (K (ml/min/g)) of tumor cells regardless of the percent weight of tumor cells in the lesions. CONCLUSIONS: The new method can produce more reliable and accurate estimates of tumor glucose metabolic rates with dynamic PET FDG studies.

Bending and flexibility of kinetoplast DNA.

We have evaluated the extent of bending at an anomalous locus in DNA restriction fragments from the kinetoplast body of Leishmania tarentolae using transient electric dichroism to measure the rate of rotational diffusion of DNA fragments in solution. We compare the rate of rotational diffusion of two fragments identical in sequence except for circular permutation, which places the bend near the center in one case and near one end of the molecule in the other. Hydrodynamic theory was used to conclude that the observed 20% difference in rotational relaxation times is a consequence of an overall average bending angle of 84 +/- 6 degrees between the end segments of the fragment that contains the bending locus near its center. If it is assumed that bending results from structural dislocations at the junctions between oligo(dA).oligo(dT) tracts and adjacent segments of B DNA, a bend angle of 9 +/- 0.5 degrees at each junction is required to explain the observations. The extent of bending is little affected by ionic conditions and is weakly dependent on temperature. Comparison of one of the anomalous fragments with an electrophoretically normal control fragment leads to the conclusion that they differ measurably in apparent stiffness, consistent with a significantly increased persistence length or contour length in the kinetoplast fragments.