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Biomedical subjects

J K Thompson

Publications and source records attributed to J K Thompson.

At least 73 records · Page 4Linked to original sources

Body image changes during early adulthood.

Results from recent studies on body image have revealed differences between college-age individuals and older samples. In this study, adults 17 to 40 years old were evaluated for their body dissatisfaction on the Figure Rating Scale. Females had higher levels of body dissatisfaction than males and these differences did not diminish with age. However, consistent with physical changes in adulthood, current and ideal ratings became more discrepant with age. Interestingly, for women, affective and cognitive dimensions of body dissatisfaction became more consistent. Research on early adulthood personality development is used to help explain these results.

Adolescent↗

Epizootic of external and internal abscesses in a large goat herd over a 16-year period.

From 1973 through 1988, 518 external and internal abscesses were diagnosed in a large commercial goat herd. Of the 518 abscesses, 238 were primary and 280 were secondary abscesses in the same or other anatomic locations. During this period, the herd varied in size from 94 goats in 1973 to 431 goats in 1988. Abscesses in the jaw area were detected in 141 goats, 4 of which developed osteomyelitis of the mandible. Sternal abscesses were detected in 72 goats, with 2 also having osteomyelitis of the sternum diagnosed at necropsy. Most of the abscesses were in the jaw, sternal, facial, and cervical areas. Lung abscesses were diagnosed at necropsy in 20 goats that most recently had 1 or more superficial abscesses. Abscess incidence was 27.6% (112 of 406) in wethers and 22.9% (154 of 687) in does. Actinomyces pyogenes was isolated most frequently by bacteriologic culture of abscess specimens and about 3 times as often as was Corynebacterium pseudotuberculosis or Staphylococcus sp, usually coagulase-positive S aureus. Bacteriologic culture of blood samples, taken during abscess episodes, yielded A pyogenes (n = 3) or C pseudotuberculosis (n = 1) in 3 goats. Results of antibiotic treatment of abscesses were disappointing, with little evidence of altering the course of the disease or sterilizing the abscess, despite the fact that the bacteria were susceptible in vitro to the antibiotics used. Excision of intact abscesses was the preferred treatment for abscesses of the jaw and facial areas.(ABSTRACT TRUNCATED AT 250 WORDS)

Abscess↗

Size overestimation among anorexics: much ado about very little?

Research on size overestimation among anorexics has failed to control for the effects of actual body size on estimated size. We obtained estimates of the size of 3 body sites from 3 groups: 13 anorexic women; 13 non-eating disordered women matched with the anorexics on actual body size; and 13 non-eating disordered women of average size. The anorexic and size-matched normal subjects did not differ in the extent to which they overestimated their body size, but both displayed significantly greater overestimation than did the subjects of average size. Both groups also estimated the actual size of their body sites to be larger than did average-size normal subjects. These findings illustrate the need for appropriate control procedures when considering body image disturbances among persons with eating disorders, and they raise questions about the psychological significance of disturbances in the perceptual component of body image.

Adolescent↗

Role of xanthine dehydrogenase and oxidase in focal cerebral ischemic injury to rat.

The role of xanthine dehydrogenase and oxidase as a source of free radicals contributing to focal cerebral ischemic injury was evaluated in Long-Evans rats after the middle cerebral artery was permanently occluded and both carotid arteries were clamped for 90 min. The fraction of xanthine dehydrogenase present as the free radical producing oxidase increased slightly from 22% in control cortex to 30% in the ischemic right cortex during the first 3 h of reperfusion and then remained relatively unchanged over the next 24 h. This increase may in part be due to entrapped plasma, which contained 4.5 +/- 0.8 nmol.min-1.ml-1 xanthine oxidase entirely in the free radical-producing form. Infarct volume was unaffected by pretreatment with 50 mg allopurinol/kg per day over 3 days before surgery but was decreased by 8% with 100 mg/kg and 24% with 150 mg/kg of allopurinol (P less than 0.05). However, inhibition of xanthine oxidase by dietary depletion of the essential molybdenum cofactor increased infarct volume by 19%, suggesting that protection by allopurinol at higher dosages was independent of xanthine oxidase inhibition. Neither xanthine oxidase present in rat brain nor circulating in plasma appears to be the primary source of oxygen radicals that contributes to infarction in focal cerebral ischemia.

Allopurinol↗

Development and validation of the Physical Appearance Related Teasing Scale.

The development and preliminary validation of the Physical Appearance Related Testing Scale (PARTS) is reported. The 18-item scale has good psychometric qualities (high internal consistency and test-retest reliabilities) and consists of two factors: Weight/Size Testing (W/ST) and General Appearance Teasing (GAT). The W/ST converges well with measures of eating disturbance, body image dissatisfaction, social comparison, depression, and self-esteem, whereas the GAT scale shows little relationship to these variables. The role of teasing history as an etiological component of body image and eating disturbance is discussed; the need for further validation work on the PARTS is addressed.

Adolescent↗

Visuospatial ability, accuracy of size estimation, and bulimic disturbance in a noneating-disordered college sample: a neuropsychological analysis.

The relationship between visuospatial ability and size accuracy in perception was assessed in 69 normal college females. In general, correlations indicated small associations between visuospatial defects and size overestimation and little relationship between visuospatial ability and level of bulimic disturbance. Implications for research on the size overestimation of body image are addressed.

Adolescent↗

Chromosome 9 from independent clones and isolates of Plasmodium falciparum undergoes subtelomeric deletions with similar breakpoints in vitro.

We show that chromosome 9 in all isolates and clones of Plasmodium falciparum examined so far exists as one of two distinctly different forms, a large form about 1.9 megabases long or a smaller form about 25% shorter. Physical maps of chromosome 9 from independent clones with large and small forms of chromosome 9, and from an isolate with the large form and 3 derived clones with the small form reveal the underlying structural basis of this size polymorphism. The small form differs from the large only in that there are subtelomeric deletions at each end, one of these deletions involving about 0.45 megabases. Remarkably, the breakpoints map within about +/- 1% of the total chromosome length for each of these populations. We discuss some possible mechanisms for this.

Animals↗

Amplification of the multidrug resistance gene in some chloroquine-resistant isolates of P. falciparum.

Resistance of Plasmodium falciparum to chloroquine shares features with the multidrug resistance (MDR) phenotype of mammalian tumor cells. We report here the sequence of pfmdr, the P. falciparum homolog of mdr. We show that pfmdr is amplified in some chloroquine-resistant parasites but not in any of the sensitive isolates examined and that pfmdr transcript levels are increased. The gene is located on chromosome 5, and in one chloroquine-resistant line with an amplified pfmdr gene, chromosome 5 is greatly enlarged. The chromosome heterogeneity is due to varying copy numbers of different-sized pfmdr-containing amplicons. The existence of an mdr gene in P. falciparum and its amplification in some chloroquine-resistant lines greatly adds to the circumstantial evidence that pfmdr mediates chloroquine resistance in these lines.

Amino Acid Sequence↗

Family correlates of bulimic characteristics in college females.

This article provides a short review of the literature that relates family characteristics to anorexia nervosa and bulimia nervosa. In addition, a quantitative analysis of the relationship between family variables and level of eating disturbance was performed on self-reported responses of 175 normal weight females in an attempt to verify an expansion of the continuum hypothesis outlined by Kagan and Squires (1985). Consistent with the continuum hypothesis, moderate relationships were found between level of family dysfunction and bulimic symptomatology. Among several family variables, inconsistent expression of affection by the mother best predicted severity of eating disturbance.

Adolescent↗

The discrepancy between emotional vs. rational estimates of body size, actual size, and ideal body ratings: theoretical and clinical implications.

Thirty-two asymptomatic college females were assessed on multiple aspects of body image. Subjects' estimation of the size of three body sites (waist, hips, thighs) was affected by instructional protocol. Emotional ratings, based on how they "felt" about their body, elicited ratings that were larger than actual and ideal size measures. Size ratings based on rational instructions were no different from actual sizes, but were larger than ideal ratings. There were no differences between actual and ideal sizes. The results are discussed with regard to methodological issues involved in body image research. In addition, a working hypothesis that differentiates affective/emotional from cognitive/rational aspects of body size estimation is offered to complement current theories of body image. Implications of the findings for the understanding of body image and its relationship to eating disorders are discussed.

Adolescent↗

Molecular karyotyping of the rodent malarias Plasmodium chabaudi, Plasmodium berghei and Plasmodium vinckei.

The molecular karyotypes of four isolates of Plasmodium chabaudi, three of the subspecies P. chabaudi adami and one P. chabaudi chabaudi, as well as P. berghei and P. vinckei were studied by means of pulsed field gradient (PFG) gel electrophoresis. Each species appears to have 14 chromosomes, ranging in size from approximately 730 kb to greater than 2000 kb. The three P. chabaudi adami isolates did not appear any more similar to each other than to the P. c. chabaudi isolate. The chromosome locations of genes for a heat shock protein (hsp) 70, ribosomal RNA (rRNA), the precursor to the major merozoite surface proteins, dihydrofolate reductase and P. falciparum antigen 352 as well as four cloned DNA markers and a telomere probe were determined. However, a number of probes representing cloned P. falciparum antigens failed to hybridize to P. chabaudi DNA. Hence genes for malaria antigens appear to be much more divergent than genes for housekeeping functions.

Animals↗

Homologous recombination within subtelomeric repeat sequences generates chromosome size polymorphisms in P. falciparum.

We present restriction maps for chromosomes 1 and 2 of six cloned lines of P. falciparum. These delineate the locations of eight genetic markers, including genes for five antigens. In parasites from diverse areas, chromosome structure is conserved in central regions but is polymorphic both in length and sequence near the telomeres. The telomeres and adjacent sequences comprise a conserved structure at the ends of most P. falciparum chromosomes. However, the subtelomeric zones are polymorphic and coincide with the locations of a repetitive element (rep20). Deletions of rep20 generate clones of P. falciparum that lack rep20 on one or both ends of chromosomes 1 or 2, and larger deletions remove telomere-proximal genes as well. The chromosome length polymorphisms can therefore be largely explained by recombination within these blocks of repeats, a mechanism that is also important in the generation of diversity in genes for repetitive antigens of P. falciparum.

Animals↗

A second antigenic heat shock protein of Plasmodium falciparum.

We describe here an antigen of Plasmodium falciparum, defined by a cDNA clone designated Ag361. The antigen is a soluble cytoplasmic 70-kD polypeptide present in all isolates analyzed and in all stages of asexual development in the blood. The antigen is a natural immunogen, although it lacks repeating epitopes of many P. falciparum antigens. Ag361 shares extensive sequence homology with the hsp70 proteins of Xenopus laevis, Drosophila melanogaster, Escherichia coli, and man, as well as a previously isolated P. falciparum hsp70 protein. The genome of P. falciparum contains at least five hsp70-like genes, located on at lest four different chromosomes.

Amino Acid Sequence↗

Evidence for the conjugal transfer of the broad host range plasmid pIP501 into strains of Lactobacillus helveticus.

The conjugative broad host range plasmid pIP501 was transferred from Streptococcus faecalis to a series of strains of lactic streptococci used commercially as dairy starter cultures. With these transconjugants as donors the plasmid was exconjugated to two strains of Lactobacillus helveticus and a commercially used strain of Strep. thermophilus. There was evidence that the plasmid could transfer between isogenic derivatives of one of the strains of Lact. helveticus. Transfer from Lact. helveticus to Strep. faecalis was also detected but at a low frequency. There was no evidence for the conjugal transfer of plasmid pIP501 into a strain of Lact. bulgaricus by exconjugation from either lactic streptococci or Lactobacillus sp.

Conjugation, Genetic↗

Identification and control of paratuberculosis in a large goat herd.

Mycobacterium paratuberculosis infection was detected in 2 goats in 1974 and in 5 goats in 1975; 5 of which were from a single herd. The magnitude of the subsequent epizootic in the goat herd was not recognized until 1977, when results of bacteriologic culture of fecal and tissue specimens, antibody determinations (agar-gel immuno-diffusion test), and histopathologic studies became available. By 1984, paratuberculosis had been diagnosed in 124 goats. Nearly all the goats were being used in antiserum production and had been given Freund complete adjuvant and human antigens. From 1974 to 1986, herd size varied from 100 to 300. The yearly incidence of paratuberculosis decreased from 13.2% (27 of 204 goats) in 1977 to 0% in 108 goats in 1985. The prevalence was higher in does. In goats that arrived on the farm in 1975 and before, 49 of 121 (40.5%) does developed paratuberculosis vs 41 of 120 (34.2%) wethers. In goats arriving on the farm in 1976 and after, 25 of 274 (8.5%) does and 9 of 216 (4.1%) wethers developed paratuberculosis. The average incubation period was approximately 4 years from arrival on the farm in every year except 1978, regardless of whether the goat was born on the farm or was purchased elsewhere.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗