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Biomedical subjects

L Young

Publications and source records attributed to L Young.

At least 199 records · Page 11Linked to original sources
PubMed1990

Cerebrovascular permeability in acute hypertension: effect of flunarizine.

The pattern of Evans blue extravasation in the brain in norepinephrine-induced acute hypertension is similar to our previous observations using horseradish peroxidase as a tracer. Pretreatment with flunarizine IV resulted in significant reduction of RISA leakage in all regions of the brains of acutely hypertensive rats. The reduction in RISA leakage in the drug-treated hypertensive group is not attributable to differences in the blood pressure elevations which were not significantly different in both groups. These studies suggest a role for calcium in the increased endothelial permeability occurring in cerebral vessels in acute hypertension. Further morphological studies are required to determine whether flunarizine reduces permeability by decreasing pinocytosis.

Acute Disease↗
PubMed1990

The role of focus groups in health education for cervical cancer among minority women.

Focus groups were used in the development of community-based public health education designed to reduce mortality from cervical cancer among black women in Forsyth County, North Carolina. The educational goals of this National Cancer Institute (NCI) funded project were to increase the proportion of black women, age 18 and older, who obtain Pap smears on a regular basis and return for followup care when necessary. A series of four focus groups were conducted to help develop the conceptual basis for designing educational messages and materials. The groups were led by a black, female professional focus group moderator, and explored a variety of health-related topics ranging from general, ordinary concerns of daily living to knowledge and attitudes about cancer screening. The group discussions suggested that health is regarded as very important to the target population, particularly when related to family functioning. Regarding the Pap smear, most women knew about the test, but had little awareness of its role in the early detection of cervical cancer. Fear and fatalism were clearly the dominant, top-of-mind reactions to cancer, and there was little differentiation among sites or types of cancer. Despite the overall pessimism, the groups agreed that early diagnosis and treatment provide the best hope for good outcomes with cancer.

Black or African American↗
PubMed1990

The influence of furosemide on plasma elimination and urinary excretion of drugs in standardbred horses.

A study of the effects of intravenous administration of either 150 mg or 250 mg of furosemide to standardbred mares pre-treated with other drugs was undertaken to determine whether a unique pattern of drug elimination into urine and from plasma for each compound occurred. Furosemide significantly reduced the plasma concentrations of codeine compared to control 2-6 h after furosemide administration. In contrast, the plasma concentrations of theophylline, phenylbutazone, pentazocine, guaifenesin and flunixin were not markedly altered by furosemide. In the case of acepromazine, clenbuterol and fentanyl, the data generated were insufficient to state with certainty whether or not furosemide affected the plasma concentrations of these three drugs. A significant reduction was noted in the urinary concentrations of guaifenesin, acepromazine, clenbuterol, phenylbutazone, flunixin, fentanyl and pentazocine within 1-4 h of furosemide administration. The urinary concentrations of theophylline remained reduced as long as 8 h after furosemide injection. Furosemide administration to horses pre-treated with codeine resulted in depression of urinary morphine concentrations 2-4 h and 9-12 h after furosemide injection. A lower furosemide dose (150 mg) produced changes in drug urinary excretion and plasma elimination equivalent to the higher dose (250 mg). It is evident that furosemide affects the urinary and plasma concentrations of other co-administered drugs but not in a predictable fashion, which limits the extrapolation of these results to as yet untested drugs.

Acepromazine↗
PubMed1990

Enterobactin-mediated iron transport in Pseudomonas aeruginosa.

A pyoverdine-deficient strain of Pseudomonas aeruginosa was unable to grow in an iron-deficient minimal medium in the presence of the nonmetabolizable iron chelator ethylene diamine-di(omega-hydroxyphenol acetic acid) (EDDHA), although addition of enterobactin to EDDHA-containing minimal media did restore growth of the pyoverdine-deficient P. aeruginosa. Consistent with the apparent ability of enterobactin to provide iron to P. aeruginosa, enterobactin-dependent 55Fe3+ uptake was observed in cells of P. aeruginosa previously grown in an iron-deficient medium containing enterobactin (or enterobactin-containing Escherichia coli culture supernatant). This uptake was energy dependent, was observable at low concentrations (60 nM) of FeCl3, and was absent in cells cultured without enterobactin. A novel protein with a molecular weight of approximately 80,000 was identified in the outer membranes of cells grown in iron-deficient minimal medium containing enterobactin, concomitant with the induction of enterobactin-dependent iron uptake. A Tn501 insertion mutant lacking this protein was isolated and shown to be deficient in enterobactin-mediated iron transport at 60 nM FeCl3, although it still exhibited enterobactin-dependent growth in iron-deficient medium containing EDDHA. It was subsequently observed that the mutant was, however, capable of enterobactin-mediated iron transport at much higher concentrations (600 nM) of FeCl3. Indeed, enterobactin-dependent iron uptake at this concentration of iron was observed in both the mutant and parent strains irrespective of whether they had been cultured in the presence of enterobactin. Apparently, at least two uptake systems for ferrienterobactin exist in P. aeruginosa: one of higher affinity which is specifically inducible by enterobactin under iron-limiting conditions and the second, of lower affinity, which is also inducible under iron-limiting conditions but is independent of enterobactin for induction.

Biological Transport↗
PubMed1990

Novel transcription from the Epstein-Barr virus terminal EcoRI fragment, DIJhet, in a nasopharyngeal carcinoma.

Transcription of Epstein-Barr virus (EBV) genes in epithelial tissue, one of the two principal cell types infected by EBV, is not well characterized. EBV transcription in a nasopharyngeal carcinoma established in nude mice, C15, has been analyzed by using strand-specific RNA probes and sequence analysis of a C15 cDNA library. In C15, two equally abundant mRNAs of 3.7 and 2.8 kilobases (kb) are encoded by the sequences that encode latent membrane protein (LMP). Hybridization with probes specific for the 3' end of the LMP mRNA to Northern (RNA) blots and sequence analysis of cDNAs representing the messages indicated that the 3.7- and 2.8-kb mRNAs are 3' coterminal. Sequence analysis of additional cDNAs revealed an mRNA that is spliced identically to the LMP mRNA but is initiated 5' to the promoter for LMP. A probe representing the sequences contained within the cDNA which are 5' to the LMP promoter identified the 3.7-kb mRNA in C15 and a low-abundance 3.7-kb mRNA in B95-8 RNA. These data indicate that transcription of the LMP-encoding sequences is complex and that LMP can be expressed from an additional RNA in both nasopharyngeal carcinoma and lymphoid cells. Hybridization with BamHI-A identified a predominant 4.8-kb mRNA and two less abundant larger-molecular-weight mRNAs transcribed in C15. These mRNAs are consistently expressed in all passages in nude mice of the C15 tumor. Hybridization with strand-specific probes and sequence analysis of three cDNAs revealed that these mRNAs are transcribed from left to right. Sequence analysis of cDNAs representing the 3' end of the mRNAs identified an open reading frame that could potentially encode a protein of 174 amino acids. In situ hybridization of a 35S-labeled RNA probe homologous to the BamHI-A cDNA to tissue sections revealed that the BamHI-A mRNA is not focally expressed and is transcribed in all cells within the C15 tumor. Linear forms of EBV DNA were not detected in any of the C15 tumors, and replicative viral antigens have not been detected. These data suggest that the C15 tumor represents a latently infected tumor and that the transcription from BamHI-A, which is expressed in all cells, is not associated with virus replication.

Amino Acid Sequence↗
PubMed1990

Epstein-Barr virus types 1 and 2 differ in their EBNA-3A, EBNA-3B, and EBNA-3C genes.

The two Epstein-Barr virus (EBV) types, EBV-1 and EBV-2, are known to differ in their EBNA-2 genes, which are 64 and 53% identical in their nucleotide and predicted amino acid sequences, respectively. Restriction endonuclease maps and serologic analyses detect few other differences between EBV-1 and EBV-2 except in the EBNA-3 gene family. We determined the DNA sequence of the AG876 EBV-2 EBNA-3 coding region and have compared it with known B95-8 EBV-1 EBNA-3 sequences to delineate the extent of divergence between EBV-1 and EBV-2 isolates in their EBNA-3 genes. The B95-8 and AG876 EBV isolates had nucleotide and amino acid identity levels of 90 and 84%, 88 and 80%, and 81 and 72% for the EBNA-3A, -3B, and -3C genes, respectively. In contrast, nucleotide sequence identity in the noncoding DNA adjacent to the B95-8 and AG876 EBNA-3 open reading frames was 96%. We used the polymerase chain reaction to demonstrate that five additional EBV-1 isolates and six additional EBV-2 isolates have the type-specific differences in their EBNA-3 genes predicted from the B95-8 or AG876 sequences. Thus, EBV-1 and EBV-2 are two distinct wild-type EBV strains that have significantly diverged at four genetic loci and have maintained type-characteristic differences at each locus. The delineation of these sequence differences between EBV-1 and EBV-2 is essential to ongoing molecular dissection of the biologic properties of EBV and of the human immune response to EBV infection. The application of these data to the delineation of epitopes recognized in the EBV-immune T-cell response is also discussed.

Amino Acid Sequence↗
PubMed1990

The factor structure of self-report DSM-III axis II symptoms and their relationship to clinicians' ratings.

A factor analysis of the entire item set of the DSM-III criteria was conducted to determine the extent to which the factors that emerged corresponded to the 11 personality disorders and three clusters included in DSM-III. Data were obtained from 552 patients who completed a self-report personality questionnaire and from 287 psychiatrists who rated their patients. Eleven questionnaire factors emerged that had eigenvalues greater than one, and at least three items emerged with factor loadings greater than 0.40. A correlational and multiple regression analysis of the questionnaire factors and clinicians' ratings showed few strong relationships between the factors and the 11 personality disorders but good correspondence with the three clusters.

Adolescent↗
PubMed1990

Asthma education: the perceptions of family physicians.

Education and training are important for people with asthma and for their family doctors in order to reduce the morbidity and mortality associated with the disease, but the most appropriate educational strategies have not been clarified. This study was conducted as a needs-assessment survey to examine the perceptions of 193 family physicians in Sydney (Australia) regarding various aspects of asthma management and patient education. Part of this sample of physicians were subsequently involved in a communitywide asthma education program. Although the measurement of airway function by doctors and patients is the cornerstone of the national asthma strategy in Australia, only 43% of family physicians surveyed regularly measured airway function in their offices and most considered that their patients rarely used a peak flow meter. Most physicians agreed with statements suggesting that asthma education was useful but some felt that education could be dangerous, or might result in fewer consultations by asthma patients. These results have provided clear directions for educating family physicians about optimal asthma management. They also provide some insight into potential barriers to the successful implementation of asthma education programs.

Asthma↗
PubMed1989

Expression of Epstein-Barr virus transformation-associated genes in tissues of patients with EBV lymphoproliferative disease.

Epstein-Barr virus (EBV) has been associated with serious or fatal lymphoproliferative disease in immunocompromised patients. EBV nuclear protein 2 and latent membrane protein are characteristically expressed in B lymphocytes proliferating in vitro in response to growth transformation by EBV. These two proteins are thought to be effectors of lymphocyte growth since they increase the expression of B-lymphocyte activation (CD23) and cell-adhesion (LFA 3 and ICAM 1) molecules in vitro. Using monoclonal antibody-immune microscopy, we have demonstrated that these two EBV proteins and their associated B-lymphocyte activation or adhesion molecules are expressed in the infiltrating B lymphocytes in immunocompromised patients with EBV lymphoproliferative disease. These monoclonal antibodies should be useful in the early diagnosis of EBV lymphoproliferative disease and in distinguishing it from other B-lymphocyte cancers associated with EBV, such as Burkitt's lymphoma. The finding of EBV nuclear protein 2 and latent membrane protein and their associated activation or adhesion molecules provides a further pathophysiologic link between EBV and the proliferation of B lymphocytes in immunocompromised patients.

Adult↗