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PubMed1996

Subarachnoid hemorrhage diagnosis: lumbar puncture is still needed when the computed tomography scan is normal.

OBJECTIVES: To determine the sensitivity of third-generation CT scanners for diagnosed nontraumatic subarachnoid hemorrhage (SAH) and to assess the impact of symptom duration on sensitivity. METHODS: A retrospective chart review was performed in a university-affiliated tertiary care hospital with an annual ED volume of > 100,000 patients. The target population was all patients who presented to the ED from January 1991 to September 1994 with symptoms suggestive of SAH and who had a final diagnosis of nontraumatic SAH based on either a positive CT scan or positive spinal fluid analysis. Patients referred from outside facilities were included if they had a CT done at the study site. All CT scans were done using third-generation scanners. Official CT scan reports were used to categorize scans as positive or negative. RESULTS: There were 140 patients identified with SAH, with a mean age of 56 years (range 10-88). The sensitivity of CT in the diagnosis of nontraumatic SAH when performed at or before 12 hours of symptom duration was 100% (80/80), and 81.7% (49/60) after 12 hours of symptom duration (95% CI 95-100% and 69.5-90.4%, respectively; p < 0.0001). Eleven of the 140 patients had a negative CT and positive spinal fluid analysis, yielding an overall sensitivity of 92.1% (129/140). CONCLUSION: The sensitivity of third-generation CT scans for SAH decreases with time from the onset of symptoms. In this sample population, CT was able to detect all patients scanned < or = 12 hours after symptom onset. Although the study demonstrated good sensitivity of CT scan reports for SAH when the scan was performed after < or = 12 hours of symptom onset, additional real-time experience is needed to better define the potential risk of a missed SAH should this population not receive the customary lumbar puncture examination in the setting of a negative CT scan.

Adolescent↗
PubMed2004

Coping and stress: a conceptual analysis.

BACKGROUND: Much work has been done towards the classification of clinical concepts in nursing. However, there is a comparative lack of analysis of non-technical terms, which nevertheless bear closely on professional practice in nursing. Within nursing classifications, the term 'coping' functions as an element in more complex conceptual structures, the term itself being left relatively undefined. The case is similar for the term 'stress'- the set of circumstances with which the individual is attempting to cope. AIMS: The aim of this paper is to arrive at grounds for consensus over the use and meaning of the widely used terms 'stress' and 'coping'. METHODS: A conceptual analysis of the terms 'stress' and 'coping' was carried out, looking at etymology, ordinary usage and theoretical contingencies, in order to generate paradigmatic cases. A range of nursing and non-nursing literature was examined in order to illustrate further the range of the terms. CONCLUSIONS: 'Stress' and 'coping' are terms which are widely used in nursing; their significance has varied overtime and in the literature, and there continues to be lack of clarity over their precise meaning and use.

Adaptation, Psychological↗
PubMed2006

Seasonal fluctuation in susceptibility to insecticides within natural populations of Drosophila melanogaster. II. Features of genetic variation in susceptibility to organophosphate insecticides within natural populations of D. melanogaster.

To elucidate genetic variation in susceptibility to organophosphate insecticides within natural populations of Drosophila melanogaster, we conducted an analysis of variance for mortality data sets of isofemale lines (10-286 lines) used in the previous studies. Susceptibility of isofemale lines to the three organophosphate insecticides was continuously distributed within each natural population, ranging from susceptible to resistant. Analysis of variance showed highly significant variation among isofemale lines in susceptibility to each insecticide for each natural population. Significant genetic variances in susceptibility to the three chemicals were estimated for the Katsunuma population; 0.0529-0.2722 for malathion, 0.0492-0.1603 for prothiophos, and 0.0469-0.1696 for fenitrothion. Contrary to the consistent seasonal tendency towards an increase in mean susceptibility in the fall, reported in the previous study, genetic variances in susceptibility to the three organophosphates did not change significantly in 1997 but tended to increase by 2- to 5-times in 1998. We tested whether both the observed situations, maintenance and increase in genetic variance in organophosphate resistance, can be generated under circumstances in which the levels of resistance to the three organophosphates tended to decrease, by conducting a simulation analysis, based on the hypothesis that resistant genotypes have lower fitnesses than susceptible ones under the density-independent condition. The simulation analysis generally explained the pattern in the mean susceptibility and genetic variances in susceptibility to the three organophosphates, observed in the Katsunuma population of D. melanogaster. It was suggested that the differences in the frequencies of resistance genes in the summer population could affect the patterns in genetic variance in organophosphate resistance in the fall population.

Animals↗
PubMed1999

[Transmission of binding over generations--contribution of the Adult Attachment Interview].

A new domain has been established within attachment research that deals with mental representations of attachment in adults, particularly in parents. This contribution describes the procedure of the Adult Attachment Interview (AAI) developed by George et al. (1996) and the scoring and classification system by Main and Goldwyn (1994). This method allow trained coders a reliable classification of different states of mind with respect to attachment based on a content and discourse analysis of the interview transcripts. By means of observational procedure of the Strange Situation for infants and the AAI for the adults, several studies support the assumption of a transmission of attachment relationships from one generation to the next one. These findings reveal that parents with secure autonomous attachment representations predominantly have infants with secure attachment patterns, parents with insecure-dismissing attachment representations mostly have children with an avoidant attachment and parents with insecure-preoccupied representations often have children with an insecure-ambivalent attachment. Less consistent results have been found for the correspondence between parents unresolved attachment status with respect to traumatic experiences and their infants' disoriented/disorganized attachment patterns. A recent study assessing attachment in six year olds revealed as well the transmission from mothers' attachment representations to those of their children for this older age. Since many studies have confirmed the correspondence of parents' and infants' attachment classifications, research interests are now directed towards the mediating processes of transmission.

Adult↗
PubMed2001

Derivation and validation of a formula to calculate the contribution of ethanol to the osmolal gap.

STUDY OBJECTIVES: We sought to evaluate the relationship between osmolal gap and serum ethanol level and derive a formula that can be used clinically to calculate the expected osmolal gap in the presence of ethanol. Some investigators have noted that the residual osmolal gap appears to increase as the ethanol level increases, and thus it is important to determine the exact relationship between these 2 values. METHODS: In part 1, a convenience sample of emergency department patients undergoing serum ethanol determination had sodium, urea, and glucose levels and osmolality determined on the same blood sample, and values were prospectively recorded. Predicted osmolality excluding ethanol was calculated with the following formula: 2 Na (mEq/L) + (Urea [mg/dL])/2.8 + (Glucose [mg/dL])/18. The osmolal gap was determined by subtracting the calculated serum osmolality excluding ethanol from the measured serum osmolality. Linear regression analysis was then used to derive a formula for the relationship between ethanol and the osmolal gap. This formula was then prospectively validated on a second convenience sample of patients. In part 2, we repeated this experiment in vitro by adding known amounts of ethanol to serum. RESULTS: We derived the formula to calculate the contribution of ethanol to the osmolal gap by using 98 observations. The mean ethanol level was 197.8 mg/dL (SD 138.5), with a range of 0 to 538.2 mg/dL. The relationship between ethanol and osmolal gap was linear, with a Pearson coefficient of correlation of 0.99. Linear regression analysis generated a model with the following formula: Osmolal gap=(Ethanol [mg/dL])/3.7 - 0.35 or, in SI units: Osmolal gap (mOsm/kg)=1.25 (Ethanol [mmol/L]) - 0.35 The 95% confidence interval (CI) for the multiplicative factor was 1/3.58 to 1/3.80 (or, in SI units, 1.21 to 1.28). The 95% CI for the additive constant was -2.19 to 1.50. We prospectively validated our formula on 128 patients. The mean residual osmolal gap for this group of patients was 0.84 mOsm/L (SD 5.65; range, -18.40 to 17.85 mOsm/L). The results of the in vitro experiments were similar. CONCLUSION: Our data suggest that the best formula for the calculation of the contribution of ethanol to osmolality is as follows: Ethanol (mg/dL)/3.7 or, in SI units: 1.25 (Ethanol [mmol/L])

Adult↗
PubMedDate not supplied

Expert videotape analysis and critiquing benefit laparoscopic skills training of urologists.

INTRODUCTION: Teaching laparoscopic skills has become the focus of the latest generation of hands-on laparoscopic courses. METHODS: Thirty-four practicing urologists, ages 31 to 61 years (mean, 46.6 years) with laparoscopic experience (range, 0 to 200, mean, 27.6 cases), 32 of whom had taken prior American Urological Association (AUA) laparoscopy courses, participated in an AUA-sponsored hands-on laparoscopic skills course over a 2-day period in August 2002 or March 2003. They all took a knowledge assessment examination and performed standardized tasks (rope passing, ring placement, and laparoscopic suturing and knot tying) at the beginning and the end of the course with a videotape analysis and critique. Prior to the repeat-skills assessment, each participant was individually critiqued and instructed based on a videotape review of their initial performance. The urologists also participated in a porcine laboratory and a pelvic trainer session totaling 6 hours between skills assessments. None of the participants had performed significant laparoscopic suturing prior to the course. RESULTS: Using Wilcoxon's signed rank test, the participants improved from a mean of 119.32 seconds to 98.36 seconds with the rope pass (P = 0.0001), and with the ring placement from a mean of 9.70/minute to 12.09/minute (P = 0.0001). All participants had significantly fewer false passes (mean, 9.35 compared with 5.21) during repeat skills assessments (P = 0.0001). Participants improved from 0.54 sutures/minute to 1.22 sutures/ minute following the video critique and practice (P = 0.0001). Degree of laparoscopic experience (number of cases), age of the urologist, and precourse knowledge (examination score) had no significant bearing on results in the initial skills assessment or in the improvement of task time (Spearman correlation coefficients). CONCLUSION: Urologists with some laparoscopic experience (mean 27.6 cases) can improve laparoscopic skills using mentored videotape analysis and experience gained from a 2-day hands-on course. Prior knowledge, degree of experience, and urologist age had no significant bearing on performance in this setting.

Adult↗
PubMed1999

Recognizing species diversity among large-bodied hominoids: a simulation test using missing data finite mixture analysis.

A persistent problem in paleoanthropology is the recognition of intra- vs. inter-specific differences within fossil samples. Exacerbating this situation is the often fragmentary nature of the fossils themselves, thus precluding rote applications of many multivariate approaches designed for complete case analyses. In this paper we apply finite mixture analysis to samples of large-bodied hominoids to test this procedure's efficacy in clustering individuals by species without a priori knowledge of group membership. In addition, we stochastically remove individual specimens and measurements, simulating small, incomplete fossil samples, and re-apply the finite mixture procedure to test how often it correctly assigns these "fragmentary" specimens. Finite mixture analysis can be highly accurate, even when confronted with small sample sizes and missing data. For example, a combination of 124 chimpanzees and humans are correctly identified in one analysis, and the accuracy drops only 2% to become 98% when the total sample size is reduced to 16 and missing data patterns are applied. In comparisons to better known methods that have been used to recognize groups in the fossil record, such as k-means, the benefits of finite mixture analysis are readily apparent. First, k-means is unable to accommodate missing data, an obvious deficiency when investigating the fossil record. Second, in direct comparisons of their ability to accurately assign "unknowns" to taxa, finite mixture performed at least as well as, and often better than, k-means in our analyses. A potential test that can be used to identify species in the fossil record, derived from comparisons of results generated from a general vs. a restricted (isometry-corrected) finite mixture analysis, is presented.

Animals↗
PubMed2005

Use of sequence data generated in the Bayer Tru Gene genotyping assay to recognize and characterize non-subtype-b human immunodeficiency virus type 1 strains.

Human immunodeficiency virus type 1 (HIV-1) protease (PR) and reverse transcriptase (RT) gene sequences obtained during antiretroviral resistance testing with a commercial genotyping assay (Tru Gene; Bayer Corp.) were analyzed to assess the utility of these data for detecting and characterizing non-subtype-B HIV-1 strains. A total of 125 viral sequences obtained from patients believed to have acquired their HIV-1 infection in Africa were analyzed, of which 121 were determined to belong to non-B subtypes. Utilizing Tru Gene sequence data alone, 92 (76%) of these viruses could be subtyped by conventional phylogenetic analysis. The addition of supplemental RT sequence data enabled a further 28 (23.1%) viruses to be classified, while one (0.9%) sample could not be classified conclusively. Two internet-accessible databases that generate HIV-1 subtypes from PR and RT sequences (HIV-SEQ and Geno 2 Pheno) were also evaluated, and both achieved 88% concordance (106/120) with phylogenetic analysis. Non-subtype-B and B-subtype HIV-1 sequences could be readily discriminated by tallying silent polymorphisms listed on the Tru Gene research report. The mean number of silent polymorphisms in the non-B HIV-1 sequences identified in this study was 58.3 (95% confidence interval [CI], 41.1 to 75.5), compared with 20.7 (95% CI, 9.9 to 31.5) for the four subtype B viruses in the study cohort and 118 case-matched B-subtype controls. Sequence data generated in the Tru Gene HIV-1 genotyping assay could, therefore, provide a ready means of tracking the prevalence and identity of non-B subtypes in HIV-1-infected populations undergoing routine antiretroviral resistance testing.

Algorithms↗
PubMed1990

Growth hormone restriction fragment length polymorphisms that segregate with 42-day live weight of mice.

The known correlation between growth hormone levels and growth rate in a number of species prompted us to examine if polymorphic restriction fragment alleles at the growth hormone locus in mice might be associated with differentiable rates of growth. An F2 population of mice was generated from crosses between a line selected for high 42-day weight and an unselected control line. The original selected and control lines exhibited mean 42-day weights of 30.6 +/- 3.8 and 20.5 +/- 2.6 g, respectively. Since the two lines also differed with respect to the restriction fragments detected by hybridization to a rat growth hormone cDNA probe, an analysis of the F2 generation was carried out to determine whether this polymorphism could be considered a quantitative trait locus for 42-day weight. The results of the analysis indicated that a polymorphic HindIII restriction fragment was correlated (P less than 0.05) with 42-day weight. However, the allele that was positively correlated with weight was the one that was fixed in the original control line, rather than the one from the selected line. While these findings support the potential use of restriction fragment length polymorphisms in quantitative trait evaluation of livestock, they also emphasize the requirement for testing such potential quantitative trait loci in the appropriate genetic background.

Animals↗
PubMed1976

[Generation and determination of pulmonary distribution disturbances (author's transl)].

Pulmonary distribution disturbances could be generated in patients with bronchial hyperreactivity by inhalation of a Falicain aerosol (Propoxipiperocainhydrochlorid); The inhomogeneities of ventilation and mechanics of breathing were determined by means of several simple and complex methods. Comparison between these methods of analysis of distribution shows that small alterations of inhomogeneity can be indicated also by simple screening tests. The results confirm the significant relationship between ventilation disturbance and pulmonary inhomogeneity. Distribution disturbance enhances both the obstructive and the restrictive component of a ventilation disturbance. These two components cannot be separated exactly by means of the parameters of ventilation and mechanics of breathing because of the influence of inhomogeneity. The generated disturbances of distribution and ventilation became regular after inhalation of an Alupent aerosol.

Aerosols↗
PubMed1989

Characterization of ovarian dysplasia by interactive morphometry.

This study defines, by morphometric analysis, criteria for the diagnosis of ovarian dysplasia. Areas of surface epithelium, adjacent to Stage I ovarian serous papillary adenocarcinoma, were diagnosed as dysplastic and evaluated for architectural and cytologic changes by means of two specially designed interactive morphometric procedures. Statistical evaluation was based on stepwise discriminant analysis of multiple quantitative descriptors. A data base was generated by analyzing histologic slides from eight normal (control), and 13 malignant ovarian tissues. Confirmation of the diagnosis was achieved in each case. The histologic criteria for ovarian dysplasia differ from those used for ovarian borderline malignancy. Interactive morphometric image analysis offers an objective method for delineating cancer precursors that could be used in ovarian biopsies taken by laparoscopy or during incidental abdominal surgery. It could be applied to cancer precursors in other locations.

Adult↗
PubMed2006

Who were the ancient Egyptians? Dental affinities among Neolithic through postdynastic peoples.

Qualitative and quantitative methods are employed to describe and compare up to 36 dental morphological variants in 15 Neolithic through Roman-period Egyptian samples. Trait frequencies are determined, and phenetic affinities are calculated using the mean measure of divergence and Mahalanobis D2 statistics for discrete traits; the most important traits in generating this intersample variation are identified with correspondence analysis. Assuming that the samples are representative of the populations from which they derive, and that phenetic similarity provides an estimate of genetic relatedness, these affinities are suggestive of overall population continuity. That is, other than a few outliers exhibiting extreme frequencies of nine influential traits, the dental samples appear to be largely homogenous and can be characterized as having morphologically simple, mass-reduced teeth. These findings are contrasted with those resulting from previous skeletal and other studies, and are used to appraise the viability of five Egyptian peopling scenarios. Specifically, affinities among the 15 time-successive samples suggest that: 1) there may be a connection between Neolithic and subsequent predynastic Egyptians, 2) predynastic Badarian and Naqada peoples may be closely related, 3) the dynastic period is likely an indigenous continuation of the Naqada culture, 4) there is support for overall biological uniformity through the dynastic period, and 5) this uniformity may continue into postdynastic times.

Black People↗
PubMed1994

Evaluation of an algorithm for the automated sequential assignment of protein backbone resonances: a demonstration of the connectivity tracing assignment tools (CONTRAST) software package.

The peptide sequential assignment algorithm presented here was implemented as a macro within the CONnectivity TRacing ASsignment Tools (CONTRAST) computer software package. The algorithm provides a semi- or fully automated global means of sequentially assigning the NMR backbone resonances of proteins. The program's performance is demonstrated here by its analysis of realistic computer-generated data for IIIGlc, a 168-residue signal-transducing protein of Escherichia coli [Pelton et al. (1991) Biochemistry, 30, 10043-10057]. Missing experimental data (19 resonances) were generated so that a complete assignment set could be tested. The algorithm produces sequential assignments from appropriate peak lists of nD NMR data. It quantifies the ambiguity of each assignment and provides ranked alternatives. A 'best first' approach, in which high-scoring local assignments are made before and in preference to lower scoring assignments, is shown to be superior (in terms of the current set of CONTRAST scoring routines) to approaches such as simulated annealing that seek to maximize the combined scores of the individual assignments. The robustness of the algorithm was tested by evaluating the effects of imposed frequency imprecision (scatter), added false signals (noise), missing peaks (incomplete data), and variation in user-defined tolerances on the performance of the algorithm.

Algorithms↗
PubMed1992

A clinical and biological validation of the DSM-III melancholia diagnosis in men: results of pattern recognition methods.

Pattern recognition methods were carried out on a sample of 80 depressed men, assessed by means of 14 items relevant to depressive symptomatology of the Structured Clinical Interview for DSM-III-R. 1985 edition (SCID). A cluster analysis generated two classes, which were described as a vital (n = 35) and a nonvital cluster (n = 45). Vital depressives were characterized by psychomotor disorders, loss of energy, cognitive disturbances, a distinct quality of mood, early morning awakening and nonreactivity (the "vital" symptoms). Our findings support the descriptive validity of the DSM-III melancholia diagnostic category, although the DSM-III criteria are too conservative and include nonrelevant symptoms (e.g., diurnal variation, anorexia-weight loss) whilst excluding some important items (e.g., loss of energy, cognitive disorders). Vital depressed men were significantly older, more severely depressed and they exhibited biological disturbances (abnormal dexamethasone suppression test, lower basal thyroid secreting hormone) as opposed to nonvital depressives. There are several arguments to support the possibility that both clusters constitute relevant stages in the overall severity of illness continuum, whilst showing qualitative differences with regard to the vital symptoms. In other words, both clusters are continuous categories within the overall severity of illness continuum and form discrete categories with regard to the vital symptoms. By merging the dimensional and categorical hypotheses, we were able to construct a new integrated threshold model: unipolar depression in men is probably a homogeneous disease with reference to overall severity of illness, but--as severity increases--vital symptoms emerge, grouping together into a distinct profile, i.e., vital depression.

Adult↗
PubMed1990

Health care expenditures for the elderly: a current and future dilemma.

Financing health care for the elderly is becoming a familiar topic in the popular press. Considering that those aged 65 yr and older constitute 12% of the population and consume about 30% of all health care expenditures, health care financing for the elderly makes a timely and interesting topic. In this paper the financing issue is addressed. With the elderly, on average, becoming more affluent, the issue of self-financing must be explored. This of course does not mean the elimination of Medicare but possibly development of a different/alternative approach. As part of our analysis, the potential political pressure from the younger generation is considered.

Aged↗
PubMed2005

Electron transfer dissociation of peptide anions.

Ion/ion reactions of multiply deprotonated peptide anions with xenon radical cations result in electron abstraction to generate charge-reduced peptide anions containing a free-radical site. Peptide backbone cleavage then occurs by hydrogen radical abstraction from a backbone amide N to facilitate cleavage of the adjacent C-C bond, thereby producing a- and x-type product ions. Introduction of free-radical sites to multiply charged peptides allows access to new fragmentation pathways that are otherwise too costly (e.g., lowers activation energies). Further, ion/ion chemistry, namely electron transfer reactions, presents a rapid and efficient means of generating odd-electron multiply charged peptides; these reactions can be used for studying gas-phase chemistries and for peptide sequence analysis.

Amino Acid Sequence↗
PubMed2006

Expression pattern of Filamin-240 in Drosophila blood cells.

The expression pattern of Filamin-240 was studied in subsets of Drosophila blood cells by means of immunofluorescent staining and Western blot analysis with use of an antibody specific to a "filamin-folding domain", a consensus motif profile generated from the 20 existing filamin repeats. Expression of Filamin-240 is restricted to lamellocytes - a special blood cell type of the cellular immune response - and is involved in the regulation of lamellocyte development. In the cher1 homozygous larvae, which lack Filamin-240 protein, a vigorous lamellocyte differentiation occurs which is further enhanced upon in vivo immune challenge by a parasitic wasp, Leptopilina boulardi. By introducing a full-length transgene encoding the Drosophila Filamin-240 protein into the cher1 Filamin-deficient homozygous mutant, the mutant blood cell phenotype was rescued. These data demonstrate that the expression of Filamin-240 is strictly lamellocyte specific in Drosophila blood cells and that the protein is a suppressor of lamellocyte development.

Animals↗