[Method of measurement of hydrogen-ion concentration in the micro- and macrovolumes of studied samples].
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Body Fluids↗
SEARCH · PubMed Health
Results for “Sampling Studies”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
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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↗
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↗
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↗
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↗
[Study of postprandial insulin secretion after a sample meal. Study of normal subjects and diabetics (apropos of 60 cases)].
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Blood Glucose↗
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↗
[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↗
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↗
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↗
Orthodontics and temporomandibular disorders: a review of the literature (1966-1988)
The orthodontist has been both accused of causing and complimented for curing temporomandibular dysfunction. To better understand the origins of these conflicting opinions, a review of the orthodontic and temporomandibular joint journals was performed for articles published since 1966. A total of 91 publications that discussed the relationship between orthodontics and temporomandibular disorders was found, and these articles were divided in three categories: viewpoint publications, case reports, and sample studies. Among the areas scrutinized in each category was the method that has led to the diversity of viewpoints. From this analysis, the following conclusions were drawn: (1) viewpoint publications and case reports were excessively represented in comparison with the number of sample studies; (2) viewpoint publications and case reports described a wide variety of conflicting opinions on the relationship between orthodontics and temporomandibular disorders; (3) unlike sample studies, viewpoint publications and case reports have little or no value in assessment of the relationship between orthodontics and temporomandibular disorders; (4) sample studies indicate that orthodontic treatment is not responsible for creating temporomandibular disorders, regardless of the orthodontic technique; and (5) sample studies indicate that orthodontic treatment is not specific or necessary to cure signs and symptoms of temporomandibular dysfunction.
Humans↗
On the homogeneity of personality disorder clusters.
This study was conducted using as subjects persons seeking psychiatric care in a public intake facility. Patients who received a diagnosis of a personality disorder (PD) on axis II constituted the study sample. The study is unique in that it attempts to analyze in a treatment population the relationships between all of the personality disorders (PD) stipulated in DSM-III with emphasis on their relationships to the associated features recorded in the remaining axes of DSM-III. The specific aim of the study was to determine the variation that exists with respect to clinical and demographic variables across the PD clusters categorized in DSM-III and across the PD types of each of the DSM-III PD clusters. In general, considerable inhomogeneity was shown within and across clusters in both demographic and clinical variables, although differences among clusters were noted as well. Cluster B differs prominently from its cohorts with respect to demographic and clinical characteristics. Some of the limitations of these results are emphasized.
Adult↗
Improved estrogen receptor assay in human mammary cancer. Technics for handling small tissue samples.
Studies of various technics that aid in performing estrogen receptor assays on small tissue samples from primary cancers of the breast are reported. It is shown how sufficient protein can be obtained from less than 100 mg of small primary tumor without ultracentrifugation to assay estrogen receptor by a simplified two-point Scatchard plot method. The resulting Kd and maximum binding site values with 36 tumor tissue samples approximated the values obtained with the more laborious, larger tissue sample-demanding six-point Scatchard plot. Target and nontarget tissue controls are easily included in an assay run of four to eight samples. For interpretive purposes the derivation of the characterizing value of the Kd for estrogen receptor is given and compared with nonspecific associating binders.
Animals↗
Temporal lobe epilepsy and aggression.
Research on temporal lobe epilepsy (TLE) and aggression is reviewed in order to learn why it has not contributed more to our understanding of the neural basis of aggression. The research problem can be resolved into two questions: Are temporal lobe epileptics more aggressive? What inferences can be drawn about the factors underlying aggression in TLE? Difficulties in finding suitable operational definitions for TLE and for aggression have, to date, received insufficient attention. In published studies, sample bias and lack of regard for the validity and reliability of behavioral assessments prevent our deciding whether an association exists between interictal aggressive behavior and TLE. Even if this association were demonstrated, one could not draw direct neurobehavioral inferences from it, since a variety of social and psychological, as well as neurophysiological variables could contribute to the association. These would have to be controlled. Methodological refinements could lead to more satisfactory answers to the first question, but the second is considerably more difficult. Some sources of complexity and apparent contradictions in the experimental literature on the neurology of aggression are discussed. They consist of technical problems, the complexity of the neural substrate of aggression and the influence of environmental cues and learning. The combined use of electrophysiological and interview techniques has yielded some interesting results with TLE patients.
Age Factors↗
Rapid detection and further characterization of infection with hepatitis B virus variants containing a stop codon in the distal pre-C region.
Recently, hepatitis B virus (HBV) replication in the absence of HBe antigenaemia has been attributed to HBV variants with a TAG stop codon in the distal pre-C region associated with one or two point mutations. We describe here a rapid detection method for the diagnosis of such HBeAg-negative HBV variants using selective oligonucleotide hybridization. The entire pre-C region was amplified by the polymerase chain reaction and hybridized under stringent conditions with non-mutated (M0), one (M1) and two (M2) point-mutated oligonucleotide probes. Of the 15 HBeAg-positive (group I) and 20 HBeAg-negative (group II) serum samples studied, 14 samples in group I and one sample in group II hybridized with M0 only and 18 samples in group II hybridized with M1 or M2, or both. The remaining two samples (from groups I and II, respectively) failed to hybridize with any of the three probes. DNA sequencing confirmed mixed distal pre-C sequences in samples hybridizing with more than one probe and also revealed novel mutations in the distal pre-C region of the two samples which failed to hybridize with any of the probes. The latter sample had a +2 frameshift and hence represented a new type of HBeAg-negative HBV variant. This method may therefore prove useful in the diagnosis of infections by HBeAg-negative HBV variants resulting from common mutations in the pre-C region, as well as for the identification of less common variants with novel mutations in the same region.
Base Sequence↗
Very high blood pressure in acute stroke.
In a study sample consisting of 388 unselected, consecutive acute stroke patients, 27 with systolic blood pressure greater than or equal to 200 mmHg and diastolic blood pressure greater than or equal to 115 mmHg were compared with the other 361 patients. The patients with high blood pressure were younger (65 vs. 73 years) and much more often had a history of hypertension (78 vs. 42%). Cardiac and vascular hypertensive manifestations were more frequent, particularly when only those patients with a history of hypertension were compared in the two groups. Alcohol abuse was mentioned in a higher proportion of hypertensives in the summaries of their medical records. No definite conclusions could be drawn with regard to the size and location of the brain lesions. Clinical symptoms did not differ between the groups, neither did the proportion of patients who could be discharged from hospital immediately. Mortality was higher in the high blood pressure group (30 vs. 14%, P less than 0.05). Thus the characteristics of patients with very high blood pressure were: younger age, much more frequent and severe previous hypertension. Alcohol abuse might be an important factor. The type, size and location of the brain lesion itself could not be statistically related to the high blood pressure, but very large lesions, particularly haemorrhages, might be associated with a reactive blood pressure response.
Age Factors↗
Aerobic biodegradation of vinyl chloride in groundwater samples.
Studies were conducted to examine the biodegradation of 14C-labeled vinyl chloride in samples taken from a shallow aquifer. Under aerobic conditions, vinyl chloride was readily degraded, with greater than 99% of the labeled material being degraded after 108 days and approximately 65% being mineralized to 14CO2.
Aerobiosis↗
Factual knowledge about AIDS and dating practices among high school students from selected schools.
Following various educational strategies by governmental and non-governmental organisations to educate youths and school teachers about HIV infection and prevention, this KABP survey was one attempt to evaluate the results. The study sample of 478 high school students was drawn from four randomly selected schools in Mashonaland and Matabeleland including high and low density, government and mission co-educational schools. The sample was randomly selected and stratified to represent sex and grade level. The KABP self administered questionnaire was used. The paper analyses the relationship between the knowledge and dating patterns. Generally, respondents demonstrated a 50pc to 80pc accuracy of factual knowledge. Of the 66pc Forms I through IV pupils who dated, 30pc preferred only sexually involved relationships and a small number considered the possibility of HIV/AIDS infection. A theoretically based tripartite coalition involving the school, the family health care services for education, guidance and support to promote responsible behaviour throughout childhood was suggested.
Acquired Immunodeficiency Syndrome↗