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Biomedical subjects

H Jordan

Publications and source records attributed to H Jordan.

At least 19 recordsLinked to original sources
PubMed1999

Constructing meiotic maps with known error probability.

We propose methods to construct meiotic gene maps while controlling the probability of a decision-error. First, a single step gene ordering procedure is presented whose decision-error probability is bounded above by a prespecified threshold. The bound for the error probability is valid under quite general circumstances. The ordering procedure is optimal in the sense of having maximal predictive probability of correct ordering among all procedures subject to the same bound on the error probability. Second, to reduce the number of hypotheses to be tested, a stepwise ordering procedure is presented. A Monte Carlo simulation study demonstrated the integrity of the proposed error bound for the stepwise procedure under a wide variety of situations, including data coming from different laboratories and marker typing errors. The stepwise procedure was applied to version 2 of the public database maintained by the Cooperative Human Linkage Center and maps of the 23 chromosomes were generated such that the probability that the order of the markers in a given chromosome is incorrect is less than 1%.

Algorithms↗
PubMed1999

Hantavirus pulmonary syndrome.

We present the first case of Hantavirus pulmonary syndrome in the Dallas/Fort Worth area. The patient was a 50-year-old previously healthy white man, who had adult respiratory distress syndrome (ARDS) and hypotensive shock after 1 week of nonspecific "viral" symptoms. Despite supportive care, the patient died within several hours of presentation. This case illustrates several of the classic hallmarks of hantavirus infection such as hemoconcentration, thrombocytopenia, ARDS, and shock.

Adult↗
PubMed1999

Scene-based and object-centered inhibition of return: evidence for dual orienting mechanisms.

We investigated whether inhibition of return (IOR) could be observed in location-based, scene-based, and object-centered frames of reference. IOR was found to move both with a separate cued object (scene-based) and with a location within a single rotating object (object-centered). Importantly, however, IOR was also associated with the environmental location cued when cuing was of a separate object (scene-based), whereas facilitation of the cued location was found when cuing was of a component within an object. These results suggest that location is of central importance to scene-based representations of separate objects, which appear to be encoded in viewer-centered coordinates, whereas environmental locus is of little relevance when attention orients within a single object. The results also provide further evidence for the coexistence of both excitation and inhibition associated with uninformative exogenous cues.

Adult↗
PubMed1997

Analysis of lipid metabolism in adipocytes using a fluorescent fatty acid derivative. I. Insulin stimulation of lipogenesis.

Stimulation of lipid synthesis (lipogenesis) is one of the most pronounced metabolic actions of insulin. Here we demonstrate insulin-stimulated lipogenesis in isolated rat adipocytes using a fatty acid derivative which carries a fluorophore. Three major fluorescent lipid products (lipids 1, 2, 3) are generated as revealed by TLC analysis and subsequent fluorescent scanning or imaging. Lipolytic digestion and labeling studies suggest monoacylglycerol-3-phosphate and diacylglycerol (-3-phosphate) structures harboring a single fluorescent fatty acyl residue each for lipids 1 and 3 (2), respectively. Fluorescent triglycerides are not generated. Assaying acylation with isolated microsomes using the purified lipids 1 and 3 indicates that incorporation of one fluorescent fatty acyl residue into glycerol(-3-phosphate) interferes with subsequent esterification. Pretreatment of the adipocytes with insulin significantly stimulates synthesis of lipids 1 and 2, only. The insulin concentration-response relationship (EC50 = 0.5 nM) and the maximal insulin response for synthesis of lipid 1 (stimulation factor = 14- to 20-fold at low glucose and 3- to 7-fold at high glucose) are comparable with those for incorporation of [3-3H]glucose into total adipocyte lipids. Thus this fluorescence-based assay may be useful for studying insulin action and lipogenesis.

Adipocytes↗
PubMed1997

A family study of autism: cognitive patterns and levels in parents and siblings.

First-degree relatives of 99 autism probands and of 36 Down's syndrome controls were assessed with standardised tests of intellectual functioning, reading, and spelling. Higher mean verbal IQ scores, and discrepancies in favour of verbal scores, were characteristic of autism relatives. No consistent differences were found on performance scales, reading, and spelling tests. Among autism relatives, siblings affected with the broad phenotype of autism had significantly lower IQ scores and poorer reading and spelling performances than unaffected siblings. However, the small size of the cognitive difference and the lack of a distinctive cognitive profile indicates that standardised cognitive measures used in this study are unlikely to improve the operationalised definition of the broad phenotype of autism. The slightly superior verbal performance of relatives in the autism group might represent some form of heterozygote advantage.

Adolescent↗
PubMed1995

Transplantation of transduced chondrocytes protects articular cartilage from interleukin 1-induced extracellular matrix degradation.

Gene therapy used in the context of delivering a therapeutic gene(s) to chondrocytes offers a new approach for treating chondrocyte-mediated cartilage degradation associated with various human arthropathies including osteoarthritis. In this study, gene delivery to human osteoarthritis chondrocytes in monolayer culture was demonstrated using two adenoviral vectors (Ad.CMVlacZ and Ad.RSVntlacZ) carrying the Escherichia coli beta-galactosidase marker gene, and a third vector (Ad.RSV hIL-1ra) containing the cDNA for human interleukin-1 receptor antagonist. At an moi of 10(3) plaque-forming units/chondrocyte, > 90% of the infected cells stained positive for E. coli beta-galactosidase activity, indicating a high efficiency of transduction. Genetically modified chondrocytes were then transplanted onto the articular surface of osteoarthritic cartilage organ cultures with and without the underlying subchondral bone. Both in situ staining of the cartilage organ cultures for E. coli beta-galactosidase activity and examination by scanning electron microscopy indicated that the transplanted chondrocytes adhered and integrated into the articular surface and continued to express transgenic protein. Chondrocytes transduced with Ad.RSV hIL-1ra and seeded onto the surface of osteoarthritic cartilage secreted high levels of biologically active IL-1 receptor antagonist. The Ad.RSV hIL-1ra-treated cartilage samples were resistant to IL1-induced proteoglycan degradation over 10 d of sustained organ culture. These data demonstrate that transplantation of transduced chondrocytes onto the articular surface protects cartilage from IL-1-induced extracellular matrix degradation.

Adenoviridae↗
PubMed1992

A protocol for rapid screening of proteoglycan-degrading metalloproteinase inhibitors.

A procedure is described for rapid, high-volume screening of proteoglycan-degrading metalloproteinase inhibitors. The procedure was developed by modifying the proteoglycan-polyacrylamide particle assay for proteases, polysaccharidases (Nagase and Woessner, 1980), and the 1,9-dimethylmethylene blue (DMB) assay for sulfated glycosaminoglycans (Farndale et al., 1982). The following modifications have made the new protocol suitable for evaluating a large number of compounds simultaneously: 1) Pipetting steps were automated using a pipetting robot. 2) Speed and sensitivity of the 1,9-dimethylmethylene assay were increased by scaling down the assay and measuring absorbance using an automatic multiwell plate reader. 3) Data capture and analysis were simplified using computer programs. The modified procedure is rapid, sensitive, reliable, and requires a small sample size. Above all, the procedure is suitable for high-volume screening: approximately 100 compounds can be evaluated in 1 day.

Acrylic Resins↗
PubMed1990

The psychometric properties of a tinnitus handicap questionnaire.

The psychometric properties of a tinnitus handicap questionnaire are reported. There were two phases in this study. In Phase I, 87 questions were administered to 100 tinnitus patients. From their responses, 59 items that were either redundant, insensitive, or had low item-total correlations were eliminated. In Phase II, the resulting 27-item questionnaire was administered to 319 patients. Fifty-three of these patients also completed psychological and psychophysical measures that were used to validate the questionnaire. A factor analysis of patients' responses revealed a three-factor structure. These three factors appeared to reflect the physical, emotional, and social consequences of tinnitus (Factor 1), hearing ability of the patient (Factor 2), and the patients' view of tinnitus (Factor 3). Although the 27-item questionnaire had high internal consistency reliability and validity as reflected by correlations with life satisfaction and depression scales, it is recommended that only the items on the Factor 1 and the Factor 2 subscales be scored because of the low internal consistency reliability of the Factor 3 subscale. This questionnaire can be used to compare a patient's tinnitus handicap with the norm, identify specific areas of handicaps, and to monitor a patient's progress with particular treatment programs.

Female↗
PubMed1989

Autism diagnostic observation schedule: a standardized observation of communicative and social behavior.

The Autism Diagnostic Observation Schedule (ADOS), a standardized protocol for observation of social and communicative behavior associated with autism, is described. The instrument consists of a series of structured and semistructured presses for interaction, accompanied by coding of specific target behaviors associated with particular tasks and by general ratings of the quality of behaviors. Interrater reliability for five raters exceeded weighted kappas of .55 for each item and each pair of raters for matched samples of 15 to 40 autistic and nonautistic, mildly mentally handicapped children (M IQ = 59) between the ages of 6 and 18 years. Test-retest reliability was adequate. Further analyses compared these groups to two additional samples of autistic and nonautistic subjects with normal intelligence (M IQ = 95), matched for sex and chronological age. Analyses yielded clear diagnostic differences in general ratings of social behavior, specific aspects of communication, and restricted or stereotypic behaviors and interests. Clinical guidelines for the diagnosis of autism in the draft version of ICD-10 were operationalized in terms of abnormalities on specific ADOS items. An algorithm based on these items was shown to have high reliability and discriminant validity.

Adolescent↗
PubMed1985

Therapeutic embolisation of the hepatic artery: a review of 75 procedures.

In 75 procedures carried out in 57 patients, hepatic arterial embolisation was shown to be a safe and effective treatment for hepatic arterial bleeding and benign vascular tumours and malformations. The median survival of patients with malignant hepatic tumours in our series compares favourably with that recorded for other methods of treatment in patients with similar tumours. Embolisation ameliorated the symptoms produced by malignant hepatic tumours, particularly those occurring in patients with functioning endocrine tumours. The commonest side-effects of embolisation were pain, pyrexia, leucocytosis, intrahepatic gas formation, and nausea. Serious complications were rare and included hepatic abscess (4 patients), septicaemia (2 patients), renal failure (2 patients), and bowel infarction (1 patient). The 2 patients with septicaemia died within a week of embolisation, and these were the only deaths directly attributable to the procedure.

Arteriovenous Malformations↗
PubMed1983

[Reactive dynamics of immunologic parameters in healthy humans and in patients with rheumatoid arthritis].

Investigations of three immune components (IgG, CRP, alpha 1 sGP) in 500 patients with rheumatoid arthritis at the beginning and the end of a spa treatment lasting 4 or 6 weeks as well as in 29 healthy test persons in monthly intervals over 2 years make clear that these immune components represent biorhythmologically regulated functions which underly a different dynamics related to the initial value. By means of the so-called "cross-over-point method" the adequate conditions can be figured. In these cases under the influence of the spa therapy a significant decrease of the dispersion at the end of the significant decrease of the dispersion at the end of the cure develops for the parameters CRP and IgG. These findings as well as the typicality of the course of the empiric regression between the beginning of the cure and the end of the cure represent criteria which are of importance for the demarcation of the dependence of the initial value to a statistical a: (a-b) effect. It is shown that the pathologically reactive dynamics of the immune components can be demarcated from the biorhythmically undisturbed dynamics.

Arthritis, Rheumatoid↗
PubMed1982

[Quantitative determination of CO2-resorption from thermo-indifferent carbon dioxide mineral-water baths through human skin].

By means of mass spectrometric precision analysis of the natural variation of the 12C/13 relation in carbon dioxide of different provenience we contrive to pursue quantitatively the penetration of CO2 from the water of natural containing carbonic acid mineral baths (mineral springs Bad Elster) into the human body (skin--blood--expiratory air). First experiments confirm that in a bath of 21 or 20 minutes duration must be reckoned with a quantity of approximately equal to 24 ml . min-1 . m-2 of resorbed carbon dioxide and that the size of the basic metabolic rate of the bathing patient as well as the CO2 concentration of the bath water have an influence on the resorption process as well as on the measurement. On the other hand, the unspecific effect of the bath activating metabolism itself does not lead to a simulation of increased resorption rates. The borderline value for the penetration of CO2 through the skin seems to be 1.0 g . 1-1, i.e. within the region of the alkali reserve of the blood. The examinations are carried on.

Adult↗
PubMed1980

[Changes in the diastole time of the human heart as influenced by 4-6 weeks of physical training in ischemic heart disease].

On the basis of former investigations, the present study deals with the effects of a 4 to 6-week training, within the framework of a health resort treatment, on the following cardialogic parameters of persons suffering from ischaemic heart disease after myocardial infarction: heart rate, duration of systoles and diastoles (and, following from this, the variance of these quantities, the diastole/systole quotient, and the "diastolic volume per unit of time", i.e., the relative diastolic share per min). Since there is a very close correlation between the heart rate and the diastole, consideration is given to frequency-independent variabilities of these quantities. It can be shown that there is a frequency-dependent behaviour under load as compared to rest, when training, and in two different age groups. The diastole/systole relation and the diastolic volume per unit of time can give additional information concerning training results. But it is not yet possible, for the time being, to show all marginal and limiting conditions required for generalizing these conclusions. From the clinical point of view, the 104 patients included in the study can be considered as a relatively homogeneous group.

Coronary Disease↗