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PubMed1990

A rapid DNA assay for the species-specific detection and quantification of Brugia in blood samples.

This report describes a new assay for detecting filarial parasites of the genus Brugia in blood samples using labeled DNA probes. The sequences of these DNA probes are based on the HhaI repeat DNA family found in the genus Brugia. These DNA probes are species-specific and can detect the DNA from a single microfilaria in hybridization assays. To adapt this test for use on blood samples collected in the field, complex steps to separate microfilariae from blood cells and to purify parasite DNA were eliminated. We found that the most effective method was to filter blood samples through 5.0 microns pore nitrocellulose membranes, lyse the microfilariae on the membranes by proteinase K digestion, denature the parasite DNA with sodium hydroxide, and hybridize with the DNA probe. With this method, individual microfilariae can be visualized and counted on autoradiograms. The assay was evaluated in a mock field study using Brugia malayi-infected jirds and was found to be an efficient and accurate method for quantifying microfilariae in blood samples.

Animals↗
PubMed2006

A multiscale expectation-maximization semisupervised classifier suitable for badly posed image classification.

This paper deals with the problem of badly posed image classification. Although underestimated in practice, bad-posedness is likely to affect many real-world image classification tasks, where reference samples are difficult to collect (e.g., in remote sensing (RS) image mapping) and/or spatial autocorrelation is relevant. In an image classification context affected by a lack of reference samples, an original inductive learning multiscale image classifier, termed multiscale semisupervised expectation maximization (MSEM), is proposed. The rationale behind MSEM is to combine useful complementary properties of two alternative data mapping procedures recently published outside of image processing literature, namely, the multiscale modified Pappas adaptive clustering (MPAC) algorithm and the sample-based semisupervised expectation maximization (SEM) classifier. To demonstrate its potential utility, MSEM is compared against nonstandard classifiers, such as MPAC, SEM and the single-scale contextual SEM (CSEM) classifier, besides against well-known standard classifiers in two RS image classification problems featuring few reference samples and modestly useful texture information. These experiments yield weak (subjective) but numerous quantitative map quality indexes that are consistent with both theoretical considerations and qualitative evaluations by expert photointerpreters. According to these quantitative results, MSEM is competitive in terms of overall image mapping performance at the cost of a computational overhead three to six times superior to that of its most interesting rival, SEM. More in general, our experiments confirm that, even if they rely on heavy class-conditional normal distribution assumptions that may not be true in many real-world problems (e.g., in highly textured images), semisupervised classifiers based on the iterative expectation maximization Gaussian mixture model solution can be very powerful in practice when: 1) there is a lack of reference samples with respect to the problem/model complexity and 2) texture information is considered negligible (i.e., a piecewise constant image model holds).

Algorithms↗
PubMed2001

Major histocompatibility complex class II polymorphisms in Macaca mulatta: factors influencing comprehensive genotyping of Macaca mulatta (Mamu)-DQA1 alleles by PCR-RFLP in archival samples.

In the last 5 years, HLA class II genotyping methods have been adapted for genotyping of class II loci in rhesus macaques. Since previously published typing protocols were used on samples that were collected and stored under ideal conditions, it was of interest to determine if these methods were adequate for genotyping a large collection of archival samples from which DNA had been isolated and stored under various conditions. Established macaque DQA1 typing protocols were modified to optimize the typing procedure and enhance the ability to successfully genotype DNA from samples that were of poor quality and/or quantity. Long-term storage of whole-blood buffy coats or stored DNA extracted from whole-blood buffy coats did not affect typing success; however, amplification and typing of DNA extracted from archival samples of plasma were difficult and resulted in a low success rate. This suggests that amplification and DQA1-genotyping of archival samples is possible with a modified protocol, but is influenced by the age and source of the sample, and to a lesser extent, the method used to extract DNA from sample substrates.

Animals↗
PubMed1993

Paraffin wax-embedded material as a source of DNA for the detection of somatic genetic changes.

Loss of genetic material, corresponding to chromosomal deletions, has been detected in a wide range of tumours and may indicate the position of a tumour suppressor gene. In order to identify the position of such a gene more precisely, many tumour samples must be studied until a minimum consensus deletion is characterized. This process is particularly necessary for lung tumours in which the deletion in chromosome 3, seen with such high frequencies in all histological subtypes, is almost always large. We have recently described the use of the polymerase chain reaction (PCR) for restriction fragment length polymorphism (RFLP) analysis of DNA isolated from small bronchial biopsies of lung tumours. In this study we adapted this technique to allow genotyping of DNA isolated from paraffin wax-embedded material (PWEM) microdissected from glass slides. We have investigated 12 lung tumours at polymorphic loci on chromosome 3 and showed allelic loss in all samples. In adapting PCR-RFLP analysis for DNA isolated from PWEM, we have concentrated on those approaches which might be adaptable to routine clinical practice. Somatic genetic changes are now being identified in many tumour types, and this information is expected to be of diagnostic and prognostic significance.

Alleles↗
PubMed1971

The distribution of cutaneous receptors in the rabbit's hind limb and differential electrical stimulation of their axons.

1. The receptive field properties and conduction velocities of single dorsal root axons, activated from the sural and cutaneous branches of the posterior tibial (medial plantar) nerves, were examined in anaesthetized rabbits.2. The sural nerve sample included all types of units previously recorded from the saphenous nerve (Brown & Iggo, 1967). In particular it was shown that electrical stimulation of the sural nerve at strengths up to 1.3T produced a volley of impulses in a pure population of slowly adapting units (Type I units).3. The medial plantar sample showed an absence of Type I slowly adapting units and Type T hair follicle units. Corresponding to this there were no touch corpuscles or tylotrich hairs in the skin of the hind foot and the fastest medial plantar axons conducted at 60-70 m/sec as opposed to 80-85 m/sec for the sural nerve. Stimulation of the medial plantar nerve at stimulus strengths close to threshold produced a volley of impulses in a nearly pure population of Type G hair follicle units.

Animals↗
PubMedDate not supplied

A comparison of different severities of nausea and vomiting during pregnancy relative to stress, social support, and maternal adaptation.

A cross-sectional and comparative research design with convenience sampling was used to recruit pregnant women from prenatal clinics in southern Taiwan between 2002 and 2003 to examine the differences in perceived stress, social support, and maternal psychosocial adaptation among women with different severities (mild or less than mild, moderate, and severe) of nausea and vomiting during pregnancy. A total of 150 pregnant women participated in this study. One-way analysis of variance indicated that perceived stress was significantly different among the 3 groups. The least significant difference post-hoc test revealed that pregnant women with mild nausea and vomiting had significantly lower stress than did pregnant women with severe nausea and vomiting. The severity of nausea and vomiting was significantly associated with the Prenatal Self Evaluation Questionnaire subscales for "acceptance of pregnancy" and "fear of helplessness and loss of control in labor." Social support and maternal psychosocial adaptation were not significantly different among these three groups. The degree of perceived stress and maternal psychosocial adaptation may be related to the severity of nausea and vomiting during pregnancy.

Adult↗
PubMed1986

The somatosensory thalamus of the raccoon: properties of single neurons responsive to light mechanical stimulation of the forepaw.

These studies were undertaken to characterize the discharge properties of single neurons of the raccoon thalamic ventrobasal complex (VB) that respond to light mechanical stimulation of the glabrous surfaces of the forepaw. Microelectrodes were used to record the extracellular activity of 146 cells in anesthetized raccoons, and all neurons were histologically verified as falling within or along the boundaries of VB. Sixty-one neurons were tested for activation by electrical stimulaton of primarily somatosensory cortex. Of these, 88% were antidromically activated, 5% were synaptically activated, and the remaining 7% were unresponsive. Out of the total sample of 146 neurons, 136 had peripheral receptive fields (RFs) that were restricted to glabrous skin and revealed properties of modality and place-specificity predictable through knowledge of properties of primary mechanoreceptive afferents. Rapidly adapting (RA) neurons accounted for 77% of this modality-place-specific sample, while 19% were slowly adapting (SA), and 4% revealed properties indicative of input from Pacinian afferents (Pc). Absolute displacement thresholds were comparable for RA and SA neurons (range = 6-415 micron). Palmar RF areas (range = 3.3-328 mm2) were significantly larger than digital RF areas (range = 0.5-98.2 mm2). As defined by exponents (b) of power functions relating instantaneous discharge frequency to displacement ramp velocity, SA neurons formed a single, homogeneous group (range of values of b = 0.633-0.720). However, RA neurons fell into three distinct groups: those showing relatively steep functions (b = 0.559-0.938), those showing relatively flat functions (b = 0.146-0.334), and those showing discontinuous, or step, functions. A small number of neurons (7% of total sample) revealed "complex" properties, not predictable from knowledge of properties of primary afferents. These included five neurons whose RFs encompassed both glabrous and hairy skin, and several linear orientation, or "tactile edge," detectors. The present results, in conjunction with those of earlier studies of the raccoon dorsal column-medial lemniscal system, lead to the conclusion that different types of information transformation are emphasized at different levels of the system. Intramodality convergences (increases in RF area) occur primarily within the cuneothalamic relay, while changes in the coding of quantitative information are primarily a function of VB neurons. The appearance of linear orientation detectors--a type of tactile "feature detector"--indicates that the synthesis of information regarding complex spatial properties of stimuli has its beginnings within the somatosensory thalamus.

Animals↗
PubMed1972

The effect of real and simulated time-zone shifts upon the circadian rhythms of body temperature, plasma 11-hydroxycorticosteroids, and renal excretion in human subjects.

1. Observations were made upon five subjects who flew through 4(1/2)-6 time zones, four of them returning later to their starting point, and upon twenty-three subjects experiencing simulated 6 or 8 hr time zones shifts in either direction in an isolation unit.2. Measurements were made of plasma concentration of 11-hydroxycorticosteroids, of body temperature, and of urinary excretion of sodium, potassium and chloride. Their rhythm was defined, where possible, by fitting a sine curve of period 24 hr to each separate 24-hr stretch of data and computing the acrophase, or maximum predicted by the sine curve.3. The adaptation of the plasma steroid rhythm was assessed by the presence of a sharp fall in concentration after the sample collected around 08.00 hr. The time course of adaptation varied widely between individuals; it was usually largely complete by the fourth day after westward, and rather later after eastward, flights. After time shift the pattern often corresponded neither to an adapted nor to an unadapted one, and in a subject followed for many months after a real flight a normal amplitude only appeared 2-3 months after flight.4. Temperature rhythm adapted by a movement of the acrophase, without change in amplitude, although on some days no rhythm could be observed. This movement was always substantial even on the first day, and was usually nearly complete by the fifth.5. High nocturnal excretion of electrolyte was often seen in the early days after time shift, more notably after simulated westward flights. Adaptation of urinary electrolyte rhythms usually proceeded as with temperature, but the movement of the acrophase was slower, more variable between individuals, more erratic, and sometimes reversed after partial adaptation. On a few days there were two maxima corresponding to those expected on real and on experimental time.6. Sodium excretion was much less regular than that of potassium, but adapted more rapidly to time shift, so that the two often became completely dissociated. Chloride behaved much as sodium.7. The time course of adaptation of the plasma steroid and urinary potassium rhythms were sufficiently similar to suggest a causal connexion. The time course of adaptation of the temperature rhythm did not coincide with that of any other component considered here.

Adrenal Cortex Hormones↗
PubMed2004

Italian version of the International Knee Documentation Committee Subjective Knee Form: cross-cultural adaptation and validation.

PURPOSE: Patient-oriented measures, represented by self-administered questionnaires, have become an important aspect of clinical outcome assessment. To be used with different language groups and in different countries, questionnaires must be translated and adapted to new cultural characteristics, and then validated by a widely accepted process to evaluate reliability and validity, fundamental characteristics for each measure. The aim of the study was to perform the cross-cultural adaptation and to assess the reliability and validity of the Italian version of the International Knee Documentation Committee (IKDC) Subjective Knee Form. TYPE OF STUDY: A cross-cultural adaptation and cross-sectional study of a sample of patients undergoing anterior cruciate ligament (ACL) reconstruction with a subsample followed up prospectively for retest reliability. METHODS: The IKDC Subjective Knee Form was culturally adapted for Italian-speaking people, following the simplified Guillemin criteria. Reliability and validity were assessed in a cross-sectional study of 50 consecutive patients undergoing ACL reconstruction. A subsample of 20 patients was followed up prospectively for retest reliability. RESULTS: The results were compared with other validated patient-oriented measures. The principal IKDC scale showed a high correlation with other patient-oriented measures as hypothesized, and it also showed good values with regard to reproducibility, consistency, and validity, compared with the versions of IKDC published in other languages. CONCLUSIONS: These findings suggest that the evaluation capacities of the IKDC Italian version are equivalent to those of other language versions of the IKDC. LEVEL OF EVIDENCE: Level II.

Adolescent↗
PubMed1993

Sex differences on the Chinese standardization sample of the WAIS-R.

The Wechsler Adult Intelligence Scale-Revised (WAIS-R) has been adapted with minor revisions for use in China and standardized on a sample of 179 adults. Sex differences on the subtests are similar to those in the United States, with women obtaining higher means on the Digit Symbol subtest and men obtaining higher means on the Information and Arithmetic subtests. Men obtained higher verbal, performance, and full-scale IQs in China. The factor structure of the Chinese WAIS-R also is similar to those obtained on the Wechsler tests in the United States and Scotland.

Adolescent↗
PubMed2004

Diagnosis of human visceral leishmaniasis by PCR using blood samples spotted on filter paper.

The polymerase chain reaction (PCR) is a simple, rapid procedure that has been adapted for the diagnosis of leishmaniasis. In the present study, 85 blood samples and seven bone marrow aspirates from 85 patients with clinical symptoms suggestive of visceral leishmaniasis from the metropolitan region of Belo Horizonte in the Brazilian State of Minas Gerais were screened using molecular and serological techniques. Samples that were negative (N = 12) and positive (N = 19) in parasitological and serological tests were used as controls. Of the 85 samples analyzed by PCR, 61 (71.7%) showed the expected amplification products in agarose gels. However, when the technique was combined with molecular hybridization, 72 samples (83.5%) gave a positive signal on film. Nineteen patients with Leishmania parasites in bone marrow cultures (positive controls) showed PCR hybridization in whole-blood samples, as did the seven bone marrow aspirates positive for Leishmania. None of the negative controls reacted in PCR or in an indirect immunofluorescent assay. These results indicate that PCR could replace the conventional parasitological examination in the diagnosis of leishmaniasis since it provides very satisfactory results with blood samples spotted on filter paper.

Animals↗
PubMed2006

Rapid determination of protein solubility and stability conditions for NMR studies using incomplete factorial design.

Sample preparation constitutes a crucial and limiting step in structural studies of proteins by NMR. The determination of the solubility and stability (SAS) conditions of biomolecules at millimolar concentrations stays today empirical and hence time- and material-consuming. Only few studies have been recently done in this field and they have highlighted the interest of using crystallogenesis tools to optimise sample conditions. In this study, we have adapted a method based on incomplete factorial design and making use of crystallisation plates to quantify the influence of physico-chemical parameters such as buffer pH and salts on protein SAS. A description of the experimental set up and an evaluation of the method are given by case studies on two functional domains from the bacterial regulatory protein LicT as well as two other proteins. Using this method, we could rapidly determine optimised conditions for extracting soluble proteins from bacterial cells and for preparing purified protein samples sufficiently concentrated and stable for NMR characterisation. The drastic reduction in the time and number of experiments required for searching protein SAS conditions makes this method particularly well-adapted for a systematic investigation on a large range of physico-chemical parameters.

Bacterial Proteins↗
PubMed1992

Ultrastructural analysis of the adaptation of articular cartilage to mechanical stimulation.

Ultrastructural analysis was conducted on samples of articular cartilage taken from both load-bearing and non-load-bearing areas with the aim of evaluating the morphologic adaptation of the articular cartilage to mechanical stimulation and identifying the mechanisms of interaction of the chondrocyte and the matrix. Through this analysis we were able to better define the adaptation process of the cartilage as well as the modalities of mechanical stress transmission. We believe that the complex formed by the chondrocyte, the pericellular matrix, and the pericellular capsule constitutes the biomechanical unit of the articular cartilage which serves as the sensor and transducer of mechanical stress. The arrangement of the collagen fibers and the proteoglycans which make up the pericellular capsule and membrane around the chondrocyte can be compared, from a mechanical standpoint, to a dynamic structure constructed in order to absorb the load stresses and protect the internal environment. From a biological standpoint, these are comparable to an extracellular-scaffold constructed with the aim of mediating the interaction between the chondrocyte and the territorial and inter-territorial compartments.

Adaptation, Physiological↗
PubMed1986

Nutrient limitation and adaptation of microbial populations to chemical transformations.

Using field-collected periphyton and bacterial isolates, we determined adaptation lag periods for microbial transformation of p-cresol. Lag periods were longer for periphyton samples collected from field sites that were low in dissolved inorganic nitrogen and phosphorus. Moreover, lag periods decreased in samples amended with N or P. Our data suggest that adaptation lag periods for microbial transformation of low concentrations of chemicals may correlate with limiting nutrient concentrations, and this correlation may provide a basis for predictive mathematical modeling of lag periods.

Journal Article↗
PubMed2005

Prevalence of pathological gambling in Quebec in 2002.

OBJECTIVE: To assess gambling behaviours and the problems associated with pathological gambling among the adult population of Quebec in 2002. METHOD: In Phase 1 of this 2-phase study, a total sample of 8842 adults was assessed. We used the South Oaks Gambling Screen (SOGS), adapted for telephone interview, to assess one-half of the sample; the other one-half was evaluated with the Canadian Problem Gambling Index (CPGI). In the study's second phase, we compared the classifications obtained from these screening instruments with classifications obtained by a psychologist using a semistructured clinical telephone interview. RESULTS: The results indicate that the prevalence of pathological gambling in 2002 (at which time 0.8% of the adult population were classified as probable pathological gamblers) did not differ from the proportion obtained in 1996 (1.0%), despite the significant decrease in gambling participation in 2002 (81% vs 90% in 1996). The most popular gambling activities were buying lottery tickets (68%), participating in fundraising draws (40%), gambling in casinos (18%), playing cards with family or with friends (10%), playing bingo (9%), and playing video lotteries (8%). The findings obtained from the SOGS and the CPGI revealed that the 2 instruments perform similarly when identifying pathological gambling prevalence. However, the results of the semistructured clinical telephone interviews differed from the results obtained with the screening instruments: 82% of the gamblers initially identified as probable pathological gamblers by the SOGS or the CPGI were not confirmed by a clinical interview. CONCLUSION: The discrepancy between the results of the screening questionnaires and the clinical evaluation is significant, and this difference needs to be addressed before further cross-sectional or longitudinal studies are conducted.

Adult↗
PubMed1999

National probability samples in studies of low-prevalence diseases. Part I: Perspectives and lessons from the HIV cost and services utilization study.

OBJECTIVE: To examine the trade-offs inherent in selecting a sample design for a national study of care for an uncommon disease, and the adaptations, opportunities and costs associated with the choice of national probability sampling in a study of HIV/AIDS. SETTING: A consortium of public and private funders, research organizations, community advocates, and local providers assembled to design and execute the study. DESIGN: Data collected by providers or collected for administrative purposes are limited by selectivity and concerns about validity. In studies based on convenience sampling, generalizability is uncertain. Multistage probability sampling through households may not produce sufficient cases of diseases that are not highly prevalent. In such cases, an attractive alternative design is multistage probability sampling through sites of care, in which all persons in the reference population have some chance of random selection through their medical providers, and in which included subjects are selected with known probability. DATA COLLECTION AND PRINCIPAL FINDINGS: Multistage national probability sampling through providers supplies uniquely valuable information, but will not represent populations not receiving medical care and may not provide sufficient cases in subpopulations of interest. Factors contributing to the substantial cost of such a design include the need to develop a sampling frame, the problems associated with recruitment of providers and subjects through medical providers, the need for buy-in from persons affected by the disease and their medical practitioners, as well as the need for a high participation rate. Broad representation from the national community of scholars with relevant expertise is desirable. Special problems are associated with organization of the research effort, with instrument development, and with data analysis and dissemination in such a consortium. CONCLUSIONS: Multistage probability sampling through providers can provide unbiased, nationally representative data on persons receiving regular medical care for uncommon diseases and can improve our ability to accurately study care and its outcomes for diseases such as HIV/AIDS. However, substantial costs and special circumstances are associated with the implementation of such efforts.

Data Collection↗
PubMed1989

[Effect of various polishing techniques on restorative resin discoloration].

The color stability of the composite filling material (Adaptabond-Hybrid) polished with different techniques -pumice-brush, sof-lex XT, adaptic polish-was tested by reflectance spectrophotometry. Samples were dipped in tea-coffee staining solution for the periods of 1, 2 or 4 weeks. All the samples were better than the group polimerized with celluloid matrix strip. No significant difference were found between the groups pumice-brush, sof-lex XT and adaptic polish for the periods 1, 2 and 4 weeks.

Color↗
PubMed2026

Haplotype Blocks Are Associated With Rapid Local Adaptation to Environmental Shifts in Wild Barley.

Genomic mechanisms of local adaptation must be highly responsive in geographic regions where climate is changing rapidly. The Levant region is a critical biodiversity hotspot and the distribution edge for many species, including the wild ancestor of domesticated barley. This region is under an accelerated desertification process, thus enforcing a rapid genomic response to the projected environmental changes. To elucidate the genomic basis of rapid local adaptation, we studied wild barley populations using an ecological-genetic sampling design that decouples environmental variation from demographic background. We collected and sequenced 300 wild barley individuals and evaluated the phenotypes of 3600 progeny plants over 3 years. Our genomic analyses revealed that local adaptation is associated with clusters of candidate genes forming haplotype blocks. These clusters are enriched with environment and stress responsive genes, including flowering time regulators, drought and heat responsive genes. We identified six candidate adaptive haplotype blocks which span 1-8 Mbp and are distributed across chromosomes 1H, 2H, 4H and 5H, each segregating as two major haplotypes. Additionally, we integrated over 2600 occurrence records into ecological and evolutionary modelling to assess the genomic vulnerability of populations to projected future climates. Our study identifies candidate genomic regions and environmental drivers of local adaptation in wild barley and highlights the advantage of haplotype blocks architecture in orchestrating an efficient response to rapid environmental change. We highlight the ecological factors most strongly associated with the observed evolutionary responses and provide insights and guidelines for biodiversity conservation and implementation of crop wild relatives in breeding.

Hordeum↗