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At least 595 records · Page 33Linked to original sources
PubMed2006

Death obsession in Palestinians.

The authors explored death obsession level and correlates among a sample (N = 601) of Palestinians living in the city of Beit Jala, the village of Al-Khader, and the Aida refugee camp in the Bethlehem area. They live in war conditions; the houses of half of them have been demolished. The Death Obsession Scale (DOS) was administered. Its alpha reliability was .92, denoting high internal consistency. Among women, it yielded 1 factor, (General Death Obsession), whereas among men it yielded 3 factors: Death Rumination, Death Dominance, and Death Idea Repetition. Palestinian men and women attained significantly lower DOS mean scores than participants from 4 Arab countries: Egypt, Kuwait, Syria, and Lebanon in 7 out of 8 comparisons. However, Palestinian women had significantly higher DOS mean score than their Spanish, American and British counterparts, whereas Palestinian men had significantly higher mean DOS score than Spanish peers. The low DOS scores of Palestinians, in proportion to other Arab samples, may reflect their adaptation to strife and violence.

Anxiety↗
PubMedDate not supplied

Optimization of the EMIT immunoassay procedure for the analysis of cannabinoids in methanolic blood extracts.

EMIT assays are commonly used for the detection of cannabinoids in urine and have been widely adapted to accommodate blood samples. Over recent years, several different kits have been produced by the assay manufacturer for this purpose. The newest kit was found to be significantly less sensitive for methanolic blood extracts than kits previously available. Modifications are described to improve the sensitivity of the newer cannabinoid kit as applied to blood extracts. In addition, information is presented which demonstrates enhanced performance of this assay procedure by the use of a commercially available enzyme substrate supplement.

Cannabinoids↗
PubMed1994

Detection of K-ras mutation in colonic effluent samples from patients without evidence of colorectal carcinoma.

BACKGROUND: K-ras gene mutation appears in more than 50% of patients with colon tumors. Both its frequency and early appearance may qualify this mutation as a potential biomarker. To enable early detection of mutant K-ras alleles, we had previously developed a sensitive polymerase chain reaction (PCR)-based assay, i.e., enriched PCR, which enables detection of one mutant K-ras allele present within 10,000 normal alleles. Using the enriched PCR, we were able to detect mutant K-ras alleles in "normal-appearing" colonic mucosa in patients with colorectal cancer. PURPOSE: A study was initiated to determine whether mutant K-ras alleles could be identified in colonic effluent samples of patients who may be at risk to develop colorectal cancer. METHODS: Over 9 years, colonic effluent samples were collected prior to routine colonoscopy from 39 patients who were apparently free of colorectal cancer. These samples were collected from patients with a family history of colorectal cancer (n = 7), adenomatous polyps (n = 7), previously resected colorectal cancer (n = 5), inflammatory bowel disorders (n = 13), normal colonoscopic examination (n = 6), and familial adenomatous polyposis (n = 1). All of the samples were double coded and analyzed for K-ras gene mutation. RESULTS: Of the 39 patients, seven were found to harbor mutant K-ras codon 12 alleles. Mutations were found in patients with a family history of colorectal cancer (three of seven), adenomatous polyps (one of seven), previously resected colorectal carcinoma (two of five), and familial adenomatous polyposis (one of one). In one case, effluent was found to harbor a mutant K-ras allele 4 years before the patient was diagnosed with colorectal cancer. CONCLUSIONS: (a) Effluent samples contain enough DNA to be detected with enriched PCR. Such samples may well be representative of the entire colon in general as opposed to a localized area such as that usually analyzed during colonoscopy. (b) K-ras gene mutation can be identified in routinely obtained colonic washings of patients who are at risk of developing colorectal cancer. Such mutations were absent in patients with inflammatory bowel disorders and in those who had undergone normal colonoscopic examinations. Detection of K-ras mutation in colonic washings may assist in identifying patients who may be at high risk for developing adenocarcinoma of the colon. IMPLICATIONS: The ability to examine colonic effluents provides a powerful and convenient source of sampling and may be adapted for future large-scale screening.

Adult↗
PubMed1997

Sleep in a truck berth.

The aim of the present pilot study was to study the effects of sleep in a truck berth. Experiment A included eight subjects who slept during two conditions (laboratory and in a truck berth during quiet conditions). Experiment B included two conditions (truck-berth sleep during quiet and noisy/disturbed conditions, respectively); six subjects participated. Polysomnography was recorded and ratings of sleep quality and postsleep sleepiness were made. During the truck-berth conditions, noise was continuously recorded. When two-tailed t tests were used, the results showed no significant effects (alpha level = 0.05) for any of the experiments. However, when one-tailed tests were used, experiment A showed a longer rapid eye movement (REM) latency for the truck-berth condition. Experiment B showed less-refreshing sleep for the disturbed condition (one-tailed test). The noise level was significantly higher during the disturbed condition. The results showed that electroencephalograph (EEG)-recorded sleep was not affected by sleeping in a truck, even when the truck was parked at a noisy location (truck terminal). However, considering some limitations of the experiments, for example small sample size, lack of adaptation night, etc., the present results should be interpreted with some caution and need to be replicated.

Adult↗
PubMed1967

Carbon Dioxide Production by Dry Grain of Zea mays.

Use of the gas chromatograph and a mercury-to-glass sealed respirometer adapted for gas syringe sampling, allowed the rapid, accurate characterization of CO(2) evolution rates from live and from dead-sterile Zea mays L. grain dried to moisture levels of 12.6 to 1.4%. The live grain at the lowest moisture level showed an elevated rate inconsistent with the exponential increase in rate of CO(2) evolution with increasing moisture found for maize with moisture contents from 4 to 12.6%. At the lowest moisture level, rates of CO(2) evolution from dead-sterile grain were greater than for live grain. Moisture had no effect on CO(2) evolution from dead-sterile grain. Increasing temperature and increasing levels of O(2) in the storage atmosphere resulted in increased rates of CO(2) evolution from both live and dead-sterile maize. CO(2) production rates from live and from dead-sterile grain decreased with increasing storage time, even though respirometer CO(2) concentrations were less than 1% at the end of the experiment. Our results indicate that CO(2) production is not a dependable measure of respiration in dry seeds. Other experiments indicate that oxygen absorption also is not reliable in maize grain.

Journal Article↗
PubMed2005

Video super-resolution using controlled subpixel detector shifts.

Video cameras must produce images at a reasonable frame-rate and with a reasonable depth of field. These requirements impose fundamental physical limits on the spatial resolution of the image detector. As a result, current cameras produce videos with a very low resolution. The resolution of videos can be computationally enhanced by moving the camera and applying super-resolution reconstruction algorithms. However, a moving camera introduces motion blur, which limits super-resolution quality. We analyze this effect and derive a theoretical result showing that motion blur has a substantial degrading effect on the performance of super-resolution. The conclusion is that, in order to achieve the highest resolution, motion blur should be avoided. Motion blur can be minimized by sampling the space-time volume of the video in a specific manner. We have developed a novel camera, called the "jitter camera," that achieves this sampling. By applying an adaptive super-resolution algorithm to the video produced by the jitter camera, we show that resolution can be notably enhanced for stationary or slowly moving objects, while it is improved slightly or left unchanged for objects with fast and complex motions. The end result is a video that has a significantly higher resolution than the captured one.

Algorithms↗
PubMed1984

An improved, automated adenylate cyclase assay utilizing preparative HPLC: effects of phosphodiesterase inhibitors.

Analysis of adenylate cyclase (ACase) activity in broken cell preparations usually involves conversion of [alpha-32P]ATP to [32P]cyclic AMP (cAMP) followed by purification of cAMP by liquid chromatographic methods. An automated, preparative reverse-phase HPLC procedure was developed that purifies cAMP rapidly and decreases variability and background. It permits the separation procedure to be validated rapidly prior to use with actual samples, and is readily adaptable for assaying guanylate cyclase, phosphodiesterases (PDE), or a variety of other related nucleotide-metabolizing enzymes. For ACase assays, 4.5% ZnSO4-10% Ba(OH)2 is added to the incubation mixture, and following centrifugation, the supernatant is injected on an HPLC apparatus fitted with a Waters Z-Module containing a 10-microns C18 reverse-phase cartridge. Using a mobile phase of 0.15 M sodium acetate-20% methanol (pH 5.0) at a flow rate of 4 ml/min, cAMP is eluted at k' greater than 1.25, whereas k' less than 0.5 for all other adenine nucleotides, permitting collection of the cAMP fraction after running the other nucleotides to waste. The method was validated by characterizing dopamine-sensitive ACase in homogenates of striatum from Sprague-Dawley rats. Basal activity (177 +/- 16 pmol/mg protein/min), the stimulation by dopamine (186 +/- 19 pmol/mg/min), the apparent Km for dopamine (5.0 +/- 1.5 microM), and expected effects of varying magnesium, EGTA, and GTP were similar to available data. However, it was found that isobutylmethylxanthine (IBMX) or theophylline, usually included in the incubation mixture as PDE inhibitors, markedly inhibited the synthesis of cAMP in both the presence and absence of dopamine. A consequence of this inhibition was a marked change in the apparent Km of dopamine calculated from a Lineweaver-Burk plot. The use of IBMX to inhibit PDEs was compared with an alternate strategy, the addition of excess exogenous cAMP. Simultaneous analysis of PDE and ACase activity was accomplished by including [3H]cAMP in the incubation and quantifying the amounts of [3H]cAMP hydrolyzed and [32P]cAMP synthesized. Without IBMX, a concentration of 1 mM exogenous cAMP was sufficient to prevent significant loss of [3H]cAMP. In the absence of exogenous cAMP, 0.5 mM IBMX did not completely prevent the breakdown of [3H]cAMP, whereas 2.5 mM IBMX did. Although there was 25% less [3H]cAMP recovered in the presence of 0.5 mM IBMX than with 2.5 mM IBMX, there was no difference in the amount of [32P]cAMP formed (either with or without dopamine).(ABSTRACT TRUNCATED AT 400 WORDS)

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMedDate not supplied

Ribosomal RNA-based oligonucleotide probes to identify marine green ultraphytoplankton.

Oligonucleotide probes based on small subunit 18S rRNA variable region sequences, were designed and used to discriminate groups of marine green ultraphytoplankton of similar size and morphology. Hybridization of probes was visualized using a combination of biotinylated oligonucleotides and fluorescein labeled avidin. Increased fluorescent signal was generated by building a complex of biotinylated probe, fluorescein labeled avidin and biotinylated anti-avidin. Cells of one phylogenetic group were easily differentiated from morphologically similar cells of a different phylogenetic group. Design of specific probes allowed identification of Mantoniella squamata, Micromonas pusilla, Pseudoscourfieldia marina and the micromonadophyte clone CCMP1194. This technique should be readily adaptable to open ocean samples and should greatly facilitate the description and quantification of ultraphytoplankton in the open ocean.

Animals↗
PubMed1995

Genetic structure of a lotic population of Burkolderia (Pseudomonas) cepacia.

The genetic structure of a population of Burkholderia (Pseudomonas) cepacia isolated from a southeastern blackwater stream was investigated by using multilocus enzyme electrophoresis to examine the allelic variation in eight structural gene loci. Overall, 213 isolates were collected at transect points along the stream continuum, from both the sediments along the bank and the water column. Multilocus enzyme electrophoresis analysis revealed 164 distinct electrophoretic types, and the mean genetic diversity of the entire population was 0.574. Genetic diversity values did not vary spatially along the stream continuum. From a canonical discriminant analysis, Mahalonobis distances (measurements of genetic similarity between populations) revealed significant differences among the subpopulations at the sediment sampling points, suggesting bacterial adaptation to a heterogeneous (or patchy) microgeographical environment. Multilocus linkage disequilibrium analysis of the isolates revealed only limited association between alleles, suggesting frequent recombination, relative to binary fission, in this population. Furthermore, the dendrogram created from the data of this study and the allele mismatch distribution are typical of a population characterized by extensive genetic mixing. We suggest that B. cepacia be added to the growing list of bacteria that are not obligatorily clonal.

Alleles↗
PubMed1989

Monoclonal antibody-mediated, immunodiagnostic competitive enzyme-linked immunosorbent assay for equine monocytic ehrlichiosis.

Competitive enzyme-linked immunosorbent assay (CELISA), mediated by a monoclonal antibody designated HybI, was developed for the diagnosis of equine monocytic ehrlichiosis. Inhibition of binding of HybI by the horse antibodies to Ehrlichia risticii was optimum at dilutions of 1:20 for serum and 1:10,000 for HybI. Mean optical densities (ODs) of positive and negative sera were 0.158 and 0.855, respectively. A comparison of ODs obtained by CELISA and indirect enzyme-linked immunosorbent assay (ELISA) indicated a marked tendency of positive and negative samples to cluster separately with respect to CELISA ODs, whereas the ELISA results displayed a continuum of ODs from negative to positive. Analysis of diagnosis by indirect fluorescent-antibody test (IFA), ELISA, and CELISA for 66 field-collected serum samples indicated that CELISA was superior to IFA and ELISA. Among 11 acute-phase serum samples negative by IFA which were obtained from horses that subsequently seroconverted, CELISA clearly demonstrated antibodies in 8 of these acute-phase sera, whereas 5 were borderline positive by ELISA. The presence of agent-specific humoral antibodies could be demonstrated conclusively by 14 days after infection. The results suggest that CELISA is more sensitive than IFA and ELISA and, owing to the marked differences between positive and negative samples, can be easily adapted for use in the field for detection of horse antibodies to E. risticii.

Animals↗
PubMed1989

Different hematologic responses to hypoxia in Sherpas and Quechua Indians.

Previous studies of the erythropoietic response to hypoxia in high-altitude natives suggest that the hematocrit and hemoglobin values in Himalayan natives (Sherpas) are lower than expected for the altitude, perhaps because of a genetic adaptation. However, differences in sampling techniques and experimental methods make comparisons difficult. Our studies were carried out to compare the erythropoietic response with the same altitude in age-matched natives of the Himalayas and Andes by the same experimental techniques. Healthy male subjects were selected in Ollagüe, Chile (n = 29, 27.3 +/- 5.9 yr) and in Khunde, Nepal (n = 30, 24.7 +/- 3.8 yr). Both of these villages are located at 3,700 m above sea level. Hematologic measurements confirmed lower hematocrit values in Nepal (48.4 +/- 4.5%) than in Chile (52.2 +/- 4.6%) (P less than 0.003). When subjects were matched for hematocrit, erythropoietin concentrations in Chile were higher than in Nepal (P less than 0.01). Detailed measurements of blood O2 affinity in Nepal showed no differences in shape or position of the O2 equilibrium curve between Sherpas and Western sojourners. Our results indicate that although Quechua Indians have higher hematocrits than Sherpas living at the same altitude, nevertheless they may be functionally anemic.

Adult↗
PubMed2001

Functional characteristics of the parallel SI- and SII-projecting neurons of the thalamic ventral posterior nucleus in the marmoset.

The functional organization of the primate somatosensory system at thalamocortical levels has been a matter of controversy, in particular, over the extent to which the primary and secondary somatosensory cortical areas, SI and SII, are organized in parallel or serial neural networks for the processing of tactile information. This issue was investigated for the marmoset monkey by recording from 55 single tactile-sensitive neurons in the lateral division of the ventral posterior nucleus of the thalamus (VPL) with a projection to either SI or SII, identified with the use of the antidromic collision technique. Neurons activated from the hand and distal forearm were classified according to their peripheral source of input and characterized in terms of their functional capacities to determine whether the direct thalamic input can account for tactile processing in both SI and SII. Both the SI- and SII-projecting samples contained a slowly adapting (SA) class of neurons, sensitive to static skin displacement, and purely dynamically sensitive tactile neurons that could be subdivided into two classes. One was most sensitive to high-frequency (> or =100 Hz) cutaneous vibration whose input appeared to be derived from Pacinian sources, while the other was sensitive to lower frequency vibration (< or =100 Hz) or trains of rectangular mechanical pulse stimuli, that appeared to receive its input from rapidly adapting (RA) afferent fibers presumed to be associated with intradermal tactile receptors. There appeared to be no systematic differences in functional capacities between SI- and SII-projecting neurons of each of these three classes, based on receptive field characteristics, on the form of stimulus-response relations, and on measures derived from these relations. These measures included threshold and responsiveness values, bandwidths of vibrational sensitivity, and the capacity for responding to cutaneous vibrotactile stimuli with phase-locked, temporally patterned impulse activity. The analysis indicates that low-threshold, high-acuity tactile information is conveyed directly to both SI and SII from overlapping regions within the thalamic VP nucleus. This direct confirmation of a parallel functional projection to both SI and SII in the marmoset is consistent with our separate studies at the cortical level that demonstrate first, that tactile responsiveness in SII largely survives the SI inactivation and second, that SI responsiveness is largely independent of SII. It therefore reinforces the evidence that SI and SII occupy a hierarchically equivalent network for tactile processing.

Afferent Pathways↗
PubMed1982

Use of Youden plot for internal quality control in the immunoassay laboratory.

The Youden two-sample plot has been adapted for use in internal quality control in the immunoassay laboratory. It can be designed to show within-batch imprecision and drift as well as long-term between-batch reproducibility and is proposed as a method that is more economical and easily understood than other current plotting procedures.

Female↗
PubMed1986

The use of a bioimpedance analyzer in the measurement of sexual arousal in male sexual deviants.

The physiological responses of sexual arousal which have been well described by Masters & Johnson, has led to the objective measure of sexual arousal. Penile tumescence is an accepted and reliable method of evaluating sexual excitability. The correlation between Penile tumescence measure and the subjective assessment of sexual arousal is high and has been reported in the range of 0.55 to 0.74 in various studies. The development of simple and inexpensive transducers for measuring penile tumescence has been a significant factor in the empirical research into sexual offenders and has led to major advances in the identification of deviant sexual arousal. This, in turn, allows more specific treatment strategies to be developed and also provides a method for evaluating and monitoring the response to treatment. Electrical bioimpedance is a technique that enables the non-invasive measurement of blood flow by the quantification of changes in the electrical conductivity of a body segment or a tissue sample and is being adapted for penile tumescence testing.

Humans↗
PubMed1975

Nocturnal increase of plasma testosterone in men: relation to gonadotropins and prolactin.

The nocturnal increase of plasma testosterone (T) in adult men has been well established. Luteinizing hormone (LH) does not show a similar increase throughout the night, whereas prolactin (PRL) does, suggesting the possibility of other hormone influence on T secretion. To investigate this possibility, 8 young adult men were studied for 4 consecutive nights in the sleep laboratory (2 nights adaptation, 2 nights blood sampling), by blood samples taken every 30 min during the 8-h sleep period, for measurement of LH, follicle stimulating hormone (FSH), PRL, and T. LH and FSH were secreted episodically, with little or no change in baseline levels during the night. PRL and T also were secreted episodically, but their baseline levels increased as the night progressed. Both LH and PRL had maximum within-subject correlations (averages equal +0.35 and +0.48 respectively) with T when they led T by 60 min. Within-subject correlations done on first differences (to remove the effect of slow trends) were near zero. LH and PRL had larger correlations with T than did FSH, for both calculations. These data suggest that both LH and PRL levels precede T levels by about 60 min. PRL thus may participate in the regulation of nocturnal T secretion in adult men.

Adult↗
PubMed2006

[Proposed UNGASS indicators and the monitoring of the AIDS epidemic in Brazil].

The objective of this study was to analyze, on the national level, the process of monitoring the proposed UNGASS indicators through the use of the Brazilian National Program for STD/AIDS indicators. Two groups of proposed indicators were analyzed in 2002 and 2005 respectively, as part of the monitoring of the progress of the UNGASS Declaration of Commitment. The availability of information and limitations in calculating the proposed indicators in Brazil were analyzed and the appropriateness of the indicators for monitoring the epidemic in Brazil was discussed. Of the 13 quantitative indicators originally proposed by UNGASS, five were not included in the National Program. One was not included due to its qualitative nature. Two of the indicators were considered to be of little use and two were not included due to the lack of available data needed for their calculation. As the epidemic in Brazil is characterized as being concentrated, within the second group of proposed UNGASS indicators those that refer to the accompaniment of epidemic among high-risk population groups were prioritized. The study highlights that the National Program concentrates its efforts in the development, adaptation, and sharing of sampling methodologies for hard to reach populations. Such activities are geared towards estimating the size of vulnerable population groups, as well as obtaining more information regarding their knowledge, attitudes, and practices. The study concludes that by creating the possibility of international comparisons between advances achieved, the proposal of supranational indicators stimulates countries to discuss and make their construction viable. In a complementary way, the national monitoring systems should focus on program improvement by covering areas that permit the evaluation of specific control and intervention actions.

Acquired Immunodeficiency Syndrome↗
PubMed2004

Identification of adeno-associated virus contamination in cell and virus stocks by PCR.

To further understand the biology of adeno-associated virus (AAV) and identify the presence of AAV in laboratory samples, we have developed a sensitive PCR-based assay using degenerate primers based on the sequence of seven diverse AAV isolates. Using these primers, we can detect free virus in viral stocks, cleared cell lysate, as well as in latently infected cells. The method can detect as little as 10 viral copies/microL of sample and can be adapted for high-throughput screening technology. With this method, we have also detected a new AAV isolate from a stock of bovine adenovirus.

Base Sequence↗