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Results for “Sampling Studies”

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At least 55 records · Page 3Linked to original sources
PubMed1986

Steroid hormone receptors in laryngeal carcinoma.

The larynx has long been shown to be a target organ for androgenic steroids in both women and men, and specific androgen receptors have been determined in normal laryngeal mucosa and in laryngeal carcinoma tissue. In this study, samples from 21 primary laryngeal carcinomas, from 4 recurrent laryngeal carcinomas and from 1 cervical metastasis of laryngeal carcinoma were obtained at the time of surgery to assay specific androgen, estrogen, and progesterone receptors. Specific androgen receptors were found in 8 samples (31%). The level of receptors varied from 1.7 femtomoles (fmol) per milligram to 7.3 fmol/mg cytosol protein. Detectable levels of specific estrogen receptors were found in 18 samples (69%) and progesterone receptors in 8 of the 15 samples studied (53%). There was no apparent correspondence with donors' sex, since samples from both females and males contained all kinds of receptors. We know that antiestrogen inhibits the growth of squamous carcinoma cells lines positive for estrogen receptors in vitro and that this effect is reversible with the appropriate hormone. Thus, the relatively high percentage of estrogen and progesterone receptors found in laryngeal carcinoma tissue may open new aspects in the treatment of laryngeal carcinoma with antihormones.

Aged↗
PubMed1987

Oral health care for hospitalized patients: the nurse's role.

Oral health care is an essential component of daily hygiene for hospitalized patients, and nurses have an important role in helping patients maintain an acceptable level of oral health. This study tested the hypothesis that nursing students are graduating with an insufficient knowledge of oral health care for hospitalized patients. Four groups of senior nursing students comprised the study sample. Study data reveal gaps in the subjects' knowledge of and rationale for oral health care procedures for hospitalized patients. However, the subjects also indicated a high level of interest in improving their ability to offer appropriate oral care services. In addition to study findings, an oral health care instructional unit outline for nursing students is presented.

Clinical Competence↗
PubMed1992

Sample size calculations for ophthalmologic studies.

Sample size calculations are shown for some common ophthalmologic study designs in which two treatments are to be compared. Included are the following three designs: 1, only one eye per subject; 2, both eyes, with each eye assigned to a different treatment; and 3, both eyes undergoing a common treatment. Continuous and binary outcomes are considered. The correlation between eyes is accounted for in the computations using a simple correction factor. For design 3, the formulas allow for a mixture of single-eye and double-eye eligible subjects. A computer program that performs the calculations is available.

Humans↗
PubMed1988

Pulmonary function is influenced by heavy alcohol consumption.

To study the possible impact of alcohol consumption on lung function (FEV1 and FVC), we observed 11,135 men and women for 5 yr. Subjects were between 20 and 90 yr of age and were selected so that they were representative of the population of the city of Copenhagen. The study population was stratified according to smoking habits and alcohol consumption. A total of 8,765 persons did not significantly change alcohol or smoking habits during the 5 yr of observation and constituted the study sample. The study sample included 32 women and 301 men with an alcohol consumption of greater than or equal to 350 g/wk (78 were nonsmokers). Multiple regression analysis showed that alcohol consumption significantly accelerated the loss of FEV1 and the loss of FVC with time. Consumption of 350 g of alcohol/wk had an effect on FEV1 comparable to the effect of smoking 15 g of tobacco/day.

Adult↗
PubMed1985

Use of biological sample banks in epidemiological studies.

Serum and urine banks have proved to be useful in the conduct of epidemiological studies. Samples collected as part of a large prospective study can be stored and retrieved later for laboratory analyses, selecting samples from groups of special interest and also from matched controls. The applications of the method are considered under three headings: firstly as a marker of a medical disorder, secondly as a measure of the extent of exposure to a harmful agent and thirdly as a direct measure of a suspected harmful or protective agent. Examples of each are given. Banks of biological samples other than serum or urine, such as hair and nail, are now being formed. The scientific opportunities of these collections are great and it will be of interest to see how they will be used.

Birth Weight↗
PubMed1979

Assay of major and minor constituents of opium samples and studies of their origin.

Samples of opium from different countries as well as from various regions of India were studied for their morphine and codeine content by gas-liquid chromatography (GLC) as their silyl ethers in a single step. Non-phenolic alkaloids (thebaine, papaverine and narcotine) were extracted with dichloromethane for GLC after conversion of the meconic acid, morphine and codeine in opium into insoluble salts with lime water. The data on alkaloidal constituents have been utilised in a determination of the origin of seized opium samples in this preliminary study.

Alkaloids↗
PubMed1989

Ultrastructure of spermatozoa & non spermatozoal cells in human semen in genital tract infections.

With a view to ascertain the possible etiology fo the morphological abnormalities seen in spermatozoa of semen from genital tract infections, 16 semen samples were studied. Samples were selected on the basis of each of them having 10-12 pus cells per high power field. Apart from routine semen analysis, the sperms were subjected to electron microscopic studies. Alterations in the ultrastructure of spermatozoa and non-spermatozoal constituents of the infected semen samples were studied. The possible etiology of a wide spectrum of abnormalities in semen found to be associated with genital infection is discussed.

Genital Diseases, Male↗
PubMedDate not supplied

[Homogenization of samples for the culture of mycobacteria. A comparative study of samples with and without centrifugation].

A homogenization method for sputum samples for the culture of acid-fast bacilli that omits the use of centrifugation, passage test tubes and balances is described. 10% sodium phosphate was used as decontaminating substance. This method facilitates the laboratory work since the samples so treated are incubated at 37 degrees C up to the next day when they are then cultured. 676 samples prepared according to this method were compared with samples prepared according to the standard method; a 6,21% positivity in the former compared to a 5,47% in the latter as well as a lower percentage of contamination were obtained. Contamination occurred in 9,91% of samples without centrifugation and in 14,35% of centrifuged samples.

Bacteriological Techniques↗
PubMed2025

Identification of Sample Processing Errors in Microbiome Studies Using Host Genetic Profiles.

In microbiome studies, sample processing errors are frequent and difficult to detect, especially in large studies involving multiple sites, personnel, and sample types. We present two complementary approaches to identify such errors using host DNA profiled via metagenomic sequencing of microbiome samples. The first approach compares host SNPs inferred from metagenomics to independently obtained genotypes (e.g., microarray genotypes) to match samples to their donors, while the second method compares metagenomics-inferred SNPs between samples to identify samples supplied by the same donor. Furthermore, we demonstrate that combining these methods with experimental metadata provides greater confidence in the identification of errors. Analyzing a longitudinal vaginal microbiome dataset, we demonstrate the ability of our approach to identify mislabeled samples. Using subsampling, we further show that our methods are robust to low sequencing coverage. Overall, our analysis highlights the frequency of processing errors in microbiome studies. We therefore recommend applying error-detection methods in all studies with suitable data.

Journal Article↗
PubMed1988

Disease based spectrum bias in referred samples and the relationship between type A behavior and coronary artery disease.

Using referred samples to study predictors of disease produces statistical problems that reduce the likelihood of obtaining statistically significant results even when a substantial relationship is present between a risk factor and a disease. The present paper refers to these problems as disease based spectrum (DBS) bias. DBS bias is present when subjects are directed into or excluded from the study sample according to their disease status. For example, healthy individuals are excluded from and diseased individuals are directed into referred samples. Therefore, DBS bias is present in referred samples. Examples from the literature on Type A behavior and coronary artery disease (CAD) are presented to illustrate how DBS bias reduces statistical associations. The results of the current research indicate DBS bias has reduced the association between Type A behavior and CAD in a number of studies reported in recent years. In addition, the present article discusses techniques for assessing and controlling for DBS bias.

Age Factors↗
PubMedDate not supplied

Crystalloid structures in retroperitoneal paragangliomas: a light and electron microscopic study.

Samples from three clinically functional retroperitoneal paragangliomas were studied by light and electron microscopy. The tumors exhibited a Zellballen pattern histologically, and ultrastructurally all three neoplasms consisted of cells containing catecholamine granules. Prominent cytoplasmic crystalloids were present in all cases. The crystalloids were identified in routine histologic sections, demonstrated eosinophilia, and stained with periodic acid-Schiff, Giemsa, phloxine-tartrazine, and azan stains. Ultrastructurally the crystalloids were osmiophilic, often appeared as slender needles, were membrane bound, and demonstrated a periodicity of 9 nm. The crystalloids, unlike the catecholamine granules, were negative for catecholamine fluorescence. X-ray microanalysis, however, revealed the selective presence of chromium in both catecholamine granules and crystalloids.

Adult↗
PubMed1988

Avoidance of contamination in element analysis of serum samples.

The selection of sampling needles and plastic material used for the storage of serum samples were studied. Sampling needles and plastic material were analyzed by neutron activation analysis. Leaching of elements from containers by acids and EDTA-solution was also followed. Also the long-term storage of serum samples for element analysis was investigated. Zn, Cu and Se concentration of serum was followed over the course of four years. The selection of sampling needles, as well as all plasticware which comes into contact with the serum, should be based on the knowledge of possible removal of elements from materials into the sample. Storage of serum samples at -18 degrees C does not change the copper, zinc or selenium concentration over the course of 4 years despite repeated melting and refreezing of the samples.

Blood Chemical Analysis↗