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Biomedical subjects

T Campbell

Publications and source records attributed to T Campbell.

At least 55 records · Page 3Linked to original sources
PubMed1997

How can psychological theory help to promote condom use in sub-Saharan African developing countries?

Condom use for HIV prevention has been very inconsistent in most sub-Saharan African countries. Studies from around the continent report that knowledge about HIV transmission is variable and seems to be related to gender, socioeconomic and educational status. There is a large body of psychological knowledge about HIV prevention which has been applied to condom promotion campaigns in developed countries. These approaches to condom promotion, based on formal theory, have not been used on a wide scale in African countries and this paper explores ways in which psychological theory might be appropriately applied in a situation of high HIV prevalence.

Africa South of the Sahara↗
PubMed1996

Silicone gel-filled breast implants in women: findings at H-1 MR spectroscopy.

PURPOSE: To evaluate, at hydrogen-1 magnetic resonance (MR) spectroscopy, the effect of implantation time, implant status, and implant removal on the amount of silicone in the liver in women with silicone gel-filled breast prostheses. MATERIALS AND METHODS: The study population included 55 women (39 patients with silicone gel-filled prostheses and seven from whom implants had been removed, and nine control subjects [eight with no implant and one with saline-filled implants]). Stimulated-echo acquisition mode, or STEAM, H-1 MR spectroscopy was performed to determine the concentration of silicone in the liver. Implant status at the time of spectroscopy was diagnosed at MR imaging. RESULTS: Twenty of 39 (51%) women with implants had ruptured prostheses. Resonances associated with the presence of silicone and partially hydrolyzed silicone (0.3 to -0.8 ppm with respect to water at 4.7 ppm) and other resonances that are not yet assigned (-2 to -5 ppm) were detected in 27 (69%) of the 39 women (17 with ruptured implants). Relative signal intensities of the silicone species detected in the liver in these women were found to vary substantially and were not correlated with the status of the implants (P > .70). Silicone resonances were not detected in the livers in the nine control subjects. After implant removal, no resonances between 0.3 and -0.8 ppm were observed in six of seven women, but silicone-related peaks were still detectable in the region of -2 to -5 ppm. CONCLUSION: Proton MR spectra obtained in the liver of women with silicone gel-filled breast implants helped measure silicone exposure.

Adult↗
PubMed1995

Congenital leukemia: report of two cases.

Congenital leukemia is a rare disease in which a leukemic process is present at birth or immediately thereafter. The majority of cases presented in the literature were reported prior to the availability of contemporary immunophenotyping methods, and lineage assignment was often made on the basis of morphology alone. Congenital leukemias may be of various lineages, although, historically, monocytic and myelomonocytic congenital leukemias appear to be the most prevalent. We present two cases of congenital leukemia with detailed immunophenotypic and cytochemical characterization. One case is of the lymphoid lineage, and the second is of myelomonocytic lineage. Neither patient displayed trisomy 21.

Female↗
PubMed1995

Dynamic magnetic resonance imaging of vocal cord closure during deglutition.

BACKGROUND & AIMS: Vocal cord closure is instrumental in airway protection during deglutition. Conventional imaging of vocal cord closure and reopening during deglutition requires invasive and nonphysiological methods. The aim of this study was to characterize the biomechanical properties of normal vocal cord adduction/abduction during deglutition using echoplanar magnetic resonance imaging, a technique that has the capability of imaging soft-tissue motion with real-time temporal resolution. METHODS: The movements of laryngeal and vocal cord structures during swallowing were determined in 11 normal volunteers by single slice and axially reformatted multislice coronal echoplanar images. RESULTS: During swallowing, the larynx ascended to peak elevation, maintained peak elevation for a discrete interval, and descended to its resting position. Vocal cord adduction occurred with a symmetric tent-like configuration at the midpoint of maximal laryngeal elevation, whereas vocal cord abduction occurred at the midpoint of laryngeal descent. Spatial analysis of vocal cord configuration during adduction determined that the vocal cords attained an initial parallel configuration during ascent, followed by closure at peak laryngeal elevation. CONCLUSIONS: These results show that the vocal cords adduct and abduct synchronously with laryngeal ascent and descent, respectively, during deglutition. Echoplanar magnetic resonance imaging constitutes a novel tool used to assess clinical abnormalities of deglutitive laryngeal function.

Adult↗
PubMed1995

Enumeration of isotype-specific antibody-secreting cells derived from gnotobiotic piglets inoculated with porcine rotaviruses.

In order to evaluate mucosal antibody responses to rotavirus, an enzyme-linked immunospot (ELISPOT) assay was adapted to enumerate antibody-secreting cells (ASC) in the mesenteric lymph nodes (MLN), lamina propria (LP) of the small intestine and spleens of gnotobiotic pigs orally inoculated with porcine rotaviruses (SB1A and Gottfried). Rotavirus-specific IgM ASC occurred by post-inoculation day (PID) 3, and numbers peaked in spleen and MLN tissues by PID 7 and in intestinal LP by PID 7-14. Numbers of rotavirus specific IgA and IgG ASC in these tissues peaked at PID 14-21. Rotavirus specific IgA ASC were predominant in the gut and IgA to IgG rotavirus specific ASC ratios were highest for all rotavirus antigen coatings in the gut LP. However, the relative ratios of specific IgA to IgG ASC were lower (ratios of 5 to 7) against combined structural and nonstructural viral antigens (rotavirus-infected fixed cell ELISPOT plates) than ratios (13 to 46) against only viral structural antigens (rotavirus-coated ELISPOT plates), indicating that there were proportionately more specific IgG ASC to the nonstructural viral antigens in the LP, the tissue adjacent to the site of rotavirus replication in the intestine. In the node cells (spleen and MLN) rotavirus-specific IgA to IgG ASC ratios were lowest and against the various ELISPOT rotavirus coatings ranged from 0.7 to 4. Gnotobiotic piglets inoculated at different ages with porcine rotaviruses generally showed similar specific immunoglobulin (Ig) ASC responses to rotavirus infection, along with similar diarrhea and virus shedding patterns in the different age groups. However, the numbers of specific IgA ASC in the MLN of 3-4 week old pigs were higher than those of 3-5 day old pigs. Although challenge of SB1A or Gottfried rotavirus-inoculated pigs with SB1A (G4P7) or Gottfried (G4P6) rotavirus revealed a high degree of protection from diarrhea and virus shedding, greater numbers of specific IgM ASC were observed in spleen after challenge of SB1A-inoculated pigs with Gottfried rotavirus (same G type, distinct P type). Thus, by using the ELISPOT technique, we successfully measured intestinal mucosal antibody-related responses to rotavirus in gnotobiotic pigs. Moreover, our results support the use of gnotobiotic piglets as an animal model to evaluate active antibody responses and protection against rotavirus infection and disease.

Animals↗
PubMed1995

Benign and malignant breast lesions: differentiation with echo-planar MR imaging.

PURPOSE: To quantify dynamic enhancement of breast lesions with echo-planar and conventional magnetic resonance (MR) imaging, to correlate these data with histologic findings and vessel density, and to evaluate MATERIALS AND METHODS: Twenty female patients with 22 breast lesions underwent conventional and MR echo-planar imaging T1 values, change in gadopentetate dimeglumine concentration, and extraction-flow products were calculated with echo-planar imaging data and were correlated with histologic findings and microvessel density. RESULTS: T1 values of cancers were not statistically significantly shorter. Cancers had more rapid uptake and higher extraction-flow products (P < .02). Sensitivity was 86% and specificity was 93% for diagnosis of malignancy. Microvessel density was higher for malignant lesions (P < .02) with an overall positive (not statistically significant) correlation between extraction-flow product and microvessel density. CONCLUSION: Echo-planar imaging appears promising for quantification of breast lesion enhancement. Microvessel data indicate that tumor angiogenesis affects enhancement.

Adolescent↗
PubMed1994

The power of listening.

The list of physician dissatisfiers--complaining patients, disgruntled employees, the egos of other physicians, and more government regulations and control--continues to increase. There is a common thread among many of these dissatisfiers. They involve relationships with people and organizational cooperation, or the lack of it. Communication problems are targeted as the source of much of the organizational heartburn. In many cases, the real problem is that there is too much talking and too little listening.

Communication↗
PubMed1993

Inherited prion disease (PrP lysine 200) in Britain: two case reports.

OBJECTIVE: To identify cases of inherited prion diseases in Britain and to assess their phenotypic features. DESIGN: Screening study of patients suspected clinically to have Creutzfeldt-Jakob disease and other neurodegenerative diseases by prion protein gene analysis. SETTING: Biochemical research department. SUBJECTS: Patients suspected to have Creutzfeldt-Jakob disease and other neurodegenerative diseases. RESULTS: Two patients with symptoms characteristic of sporadic Creutzfeldt-Jakob disease were found to have inherited prion protein disease (PrP lysine 200), with a mutation at codon 200 of the prion protein gene. Both were homozygous at codon 129 of the gene. One patient was a man aged 58 of British descent while the other was of Libyan Jewish origin. CONCLUSION: Two foci of inherited prion disease are known, among Libyan Jews and in Slovakia. A separate British focus of the disease may also exist. Heterozygosity at codon 129 may lead to reduced penetrance of the mutation.

Codon↗
PubMed1993

Immunohistochemical localisation of pS2 protein in ductal carcinoma in situ and benign lesions of the breast.

The expression of pS2 was examined histochemically in paraffin sections taken from biopsy material from patients diagnosed with ductal carcinoma in situ (DCIS). Often intense immunoreactivity, to an anti-pS2 monoclonal antibody, was observed in comedo, solid, cribriform and micropapillary types of DCIS, with significant positivity found in 63-67% of cases. In 15 samples analysed, we found a good correlation between pS2 expression and presence of progesterone receptor positive cells, but not with estrogen receptor. There was only a limited degree of correspondence between the cells staining with these anti-sera. Some pS2 positive cells were also seen in normal acini in areas adjacent to cancer but much less frequently in sections of normal breast from reduction mammoplasty. Most normal areas were negative, as were cysts. In benign proliferative conditions (seen in sections with and without DCIS) such as adenosis, sclerosing adenosis, mild and florid ductal epithelial hyperplasia, significant pS2 positivity was seen in about 50% of cases. These results suggest that there is a progressive increase in pS2 from normal to benign to cancer cells and that this gene is expressed in both the invasive and pre-invasive forms of breast cancer.

Biopsy↗
PubMed1993

Constituent syllable effects in a nonsense-word repetition task.

Multisyllabic nonsense-word repetition tasks have been used to provide evidence on the phonological processing operations of children with language impairment, independent of their lexical knowledge (Gathercole & Baddeley, 1990; Kamhi, Catts, Mauer, Apel, & Gentry, 1988). However, recent evidence (Gathercole, Willis, Emslie, & Baddeley, 1991) and speculation (Snowling, Chiat, & Hulme, 1991) suggest that the nonsense words employed in such tasks may not be equally "nonsensical." The present investigation directly tested the effect on repetition performance of one previously uncontrolled characteristic of multisyllabic nonsense words: the lexical status (word or nonword) of their stressed syllables. Normally achieving school-age boys repeated nonsense words with lexical stressed syllables significantly more accurately than nonsense words with nonlexical stressed syllables. These results suggest the need to control, at a minimum, the lexical status of constituent syllables in constructing nonsense-word stimuli.

Child↗
PubMed1993

cAMP-independent, G protein-linked inhibition of Na+/H+ exchange in renal brush border by D1 dopamine agonists.

When D1 dopamine agonists are incubated with renal cortical tissue, Na+/H+ exchange activity is inhibited, presumably due to D1 receptor-mediated stimulation of adenylyl cyclase and subsequent increase in protein kinase A activity. Although the role of adenosine 3',5'-cyclic monophosphate (cAMP) and cAMP-dependent protein kinase in the regulation of Na+/H+ exchange activity is well established, receptors functionally coupled to adenylyl cyclase can regulate Na+/H+ exchange activity independently of changes of cAMP accumulation. The current studies were designed to determine whether D1 agonists can inhibit Na+/H+ exchange activity independently of changes of cAMP accumulation and also to determine the role of G proteins in this process. The D1 agonist, fenoldopam, inhibited Na+/H+ exchange activity in a time-related and concentration-dependent manner. The 50% inhibitory concentration was 5-34 microM. Occupation of the renal D1 receptor mediates this action, since the D1 antagonist, SKF 83742, partially blocks the effect. This action, however, was independent of adenylyl cyclase, protein kinase A, and protein kinase C activity. Inhibition of adenylyl cyclase with dideoxyadenosine or inhibition of protein kinase A and C with the isoquinolines N-(2-guanidinoethyl)-5-isoquinolinesulfonamide hydrochloride (H-4) and 1-(5-isoquinolinesfulfonyl)-2-methylpiperazine (H-7) did not block the effect of fenoldopam on the exchanger. The action of fenoldopam is not due to an amiloride-like action on the exchanger, because kinetic analysis of the inhibitory action was noncompetitive and the effect of fenoldopam was time dependent. The process involved G proteins, since guanosine 5'-O-(2-thiodiphosphate) prevented while guanosine 5'-O-(3-thiotriphosphate) increased the inhibitory effect of fenoldopam.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1993

The gay bashing scene chez Proust.

This essay presents a contemporary translation of and brief commentary on the gay bashing scene found in Marcel Proust's A la Recherche du Temps perdu: Le Côté de Guermantes, Tome I. The paper notes that Proust argues in this passage for the acceptance of homosexuality for two main reasons: because gay bashing won't eradicate it; and because gayness is the simple, direct movement of a being toward perceived beauty. The paper suggests that Proust reveals his own gayness (and that of his protagonist) by employing the latter argument in defense of homosexuality whereas, throughout the novel, he presents heterosexual attraction as an immensely indirect, artistically manufactured construct.

France↗