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Biomedical subjects

J Harris

Publications and source records attributed to J Harris.

At least 325 records · Page 18Linked to original sources

Factors predicting for response, time to treatment failure, and survival in women with metastatic breast cancer treated with DAVTH: a prospective Eastern Cooperative Oncology Group study.

Six hundred twenty-four women with metastatic breast cancer were entered on Eastern Cooperative Oncology Group (ECOG) study EST 2181. Patients were treated with mitolactol, doxorubicin, vincristine (DAV), tamoxifen, and fluoxymesterone (DAVTH). Nine patients were canceled, and 114 were ineligible (half because of concomitant diseases). Among the 501 eligible patients, the overall response rate was 54% (14% complete response and 5% not assessable). The median time to treatment failure (TTF) was 9.0 months, and the median survival was 20.9 months. Multivariate models were fit on a randomly chosen half of the eligible cases and then verified on the other half. About half of the variables that were significant in the models remained significant in the verification data set. In the verification data set the variables that remained significantly associated with lower probability of response were three or more organ sites of disease and lack of nodal metastases; the variables associated with a significantly shorter TTF were liver metastases, estrogen receptor (ER)-negativity, and prior adjuvant therapy. The variables associated with significantly shorter survival were liver metastases, ER negativity, three or more organ sites of disease, and prior adjuvant chemotherapy. None of the variables in the data set had a significant influence on toxicity. The 125 patients aged over 65 years did not have worse toxicity or worse prognosis than younger patients. Ineligible patients had significantly less response but virtually identical TTF curves, survival curves, and toxicities. Therefore, patient discriminants are of paramount importance in predicting the outcome of treatment. Many of the current criteria for eligibility for entry on study may not be justified.

Adenocarcinoma↗

Rapidity and accuracy of tracheal intubation in a mannequin: comparison of the fibreoptic with the Bullard laryngoscope.

Successful tracheal intubation with the flexible fibreoptic bronchoscope requires a certain amount of skill which is acquired by practice. It has been suggested that the new Bullard laryngoscope may be mastered more easily. To determine if learning was superior with a flexible fibreoptic or the Bullard device, the ease of tracheal intubation with both devices was compared by first-year anaesthetic residents, using a mannequin modified to make intubation difficult. The Bullard laryngoscope was as easy to master as the flexible fibreoptic device, but passage of the tracheal tube took longer. Both devices require a similar amount of practice.

Anesthesiology↗

Decreased expression of the glutathione S-transferases alpha and pi genes in human renal cell carcinoma.

Using the polymerase chain reaction (PCR), a human kidney glutathione S-transferase (GST) alpha cDNA clone (GST alpha 12 K) was synthesized; it is identical to a known liver GST alpha cDNA clone except for one base change (G----A), indicating that an alpha class gene expressed in human kidney is similar to one expressed in human liver. Comparisons were made in the expression of GST alpha and GST pi between renal cell carcinoma and adjacent non-neoplastic tissue. Messenger RNA expression in 30 cases was determined by Northern blotting, and GST protein from nine of these cases was analyzed by HPLC. The GST alpha gene products were expressed at near-zero levels. The GST pi gene product was the predominant GST in tumors, but was decreased in absolute amount compared with control tissue, the tumor/control ratios for the GST pi gene obtained by Northern blots and HPLC analysis being 0.50 +/- 0.07 and 0.36 +/- 0.07 respectively. The resulting pattern in renal cell carcinoma therefore shows a predominance of GST pi. Since it is assumed that renal cell carcinoma derives from the proximal tubular epithelial cells which are high in GST alpha, this implies a dedifferentation in the GST expression pattern.

Blotting, Northern↗

Teaching of medical ethics.

Teaching medical ethics in Manchester within the introductory course of obstetrics and gynaecology is a joint activity with the Centre for Social Ethics and Policy. This interdisciplinary teaching has evolved through lecture sessions with small-group discussions dealing with topics of interest in human reproduction. The small-group discussion have been replaced by an open debate conducted by the students. Their own involvement and participation and an exposure to the disciplines of the humanities has broadened their approach to different ways of problem-solving of these real issues.

Bioethical Issues↗

Performance and cost-effectiveness of a dual rapid assay system for screening and confirmation of human immunodeficiency virus type 1 seropositivity.

Recent studies have shown that rapid, instrument-free assays for the detection of antibody to human immunodeficiency virus (HIV) can be as sensitive and specific as enzyme-linked immunosorbent assay (ELISA) for screening of donated blood in developing countries. Currently, however, specimens which test positive on a screening assay must still be confirmed by Western blot (immunoblot), a method which is not feasible in most developing-country laboratories. We examined whether a testing hierarchy which utilizes neither conventional ELISA nor Western blot can be reliably used for screening and confirmation of HIV infection in a high-risk population. In a retrospective analysis of 3,878 specimens which were screened for antibody to HIV in Kinshasa, Zaire, we observed that a testing hierarchy consisting of duplicate HIVCHEK screening assays followed by duplicate Serodia-HIV confirmatory assays resulted in correct confirmation of all ELISA- and Western blot-positive specimens. We conclude that such a testing hierarchy can produce highly accurate results for identification of positive specimens in routine HIV testing and provides a practical alternative to conventional methods of HIV screening and confirmation.

Blood Donors↗

A novel T-cell protein which recognizes a palindromic sequence in the negative regulatory element of the human immunodeficiency virus long terminal repeat.

Two major protein-binding sites within the negative regulatory element of the human immunodeficiency virus type 1 long terminal repeat have been identified. One (site B) contained a palindromic sequence with homology to steroid/thyroid hormone response elements but was distinct from previously described binding sites of this class. A novel T-cell protein recognized the palindromic sequence within site B and also bound estrogen- or thyroid hormone-response elements with lower affinity. A 7-base-pair mutation in the site B palindrome, which destroyed protein binding, resulted in increased expression from the human immunodeficiency virus type 1 long terminal repeat in T cells.

Base Sequence↗

A truncated, secreted form of the epidermal growth factor receptor is encoded by an alternatively spliced transcript in normal rat tissue.

Two independent cDNA clones corresponding to a 2.7-kilobase (kb) epidermal growth factor receptor (EGF-R) mRNA were isolated from a rat liver cDNA library. Sequence analysis revealed 100% homology in the external domain when compared with the full-length rat EGF-R nucleotide sequence and 80 to 90% similarity relative to the human EGF-R. However, the 3'-terminal sequence of these clones did not match EGF-R or any other known sequence(s) and was distinct from the 3' end of the 2.8-kb mRNA, which encodes a truncated EGF-R in A431 cells. The deduced amino acid sequence revealed an open reading frame which is homologous to the external domain of the EGF-R but which terminates prior to the transmembrane region. Southern blot analysis of rat genomic DNA indicated that the 3'-terminal sequence of this transcript is derived from the EGF-R gene. Analysis of a genomic clone containing the 3' end of the 2.7-kb transcript revealed that this sequence is present as a discrete exon in the mid-region of the receptor gene in proximity to the exon encoding the transmembrane domain. Introduction of an expression vector containing the truncated EGF-R cDNA into Chinese hamster ovary (CHO) cells led to the expression of a 95-kilodalton protein which was detected in conditioned media, by using antisera directed against the EGF-R. A similarly sized protein was also detected in the media of WB cells, a continuous, nontransformed line of rat hepatic epithelial cells. Northern (RNA blot) analysis established that the truncated receptor is encoded by a 2.7-kb transcript found in normal rat liver. Furthermore, Northern analysis of rat poly(A)+ RNA showed that the 2.7-kb EGF-R transcript is expressed at differing levels in various fetal and adult tissues. These data indicate that alternative splicing of the EGF-R primary transcript yields a 2.7-kb mRNA which codes for a truncated form of the receptor. This receptor is secreted by rat hepatic epithelial cells in culture, which suggests that it may be secreted by normal rat cells or tissues and perhaps serve an as yet unknown physiological function.

Amino Acid Sequence↗

Intraoperative autotransfusion: a community program.

The Southern Arizona Regional Blood Program of the American Red Cross in cooperation with Tucson hospitals conducted a pilot program of the provision of intraoperative autologous transfusion services. The service provided instruments, staff, and disposables to salvage and wash red cells shed during scheduled and emergency surgical procedures. The lower cost and other efficiencies of providing this service through a regional blood center suggest that it may be more appropriate to offer this service on a regional basis than exclusively within a hospital. Hospitals and regional blood centers should consider offering this advanced form of hemotherapy to their communities.

Arizona↗

Workplace flexibility.

Whether your organization is in a growth pattern or downsizing, you are probably facing change. To gain some insight into your options, here is an in-depth look at the problems and benefits of some flexible work arrangements from a just published study by Catalyst.

Employment↗

AIDS policy and education in the workplace.

It is inevitable that every workplace will someday be affected by an employee with AIDS or positive HIV. Policy and education should be in place before the first case appears. Most companies do not have AIDS policies or educational programs. Managers and supervisors must have current information and concrete guidelines to deal effectively with an employee with HIV. Other problems that may occur and disrupt the work force are: concerns of coworkers, legal issues, and problems with confidentiality. The occupational health nurse is a key figure in the development of policy and planning for education of all employees.

Acquired Immunodeficiency Syndrome↗

Field testing and comparative evaluation of rapid, visually read screening assays for antibody to human immunodeficiency virus.

Five rapid, visually read assays for detection of antibody against human immunodeficiency virus (HIV) were evaluated on fresh serum samples from 4000 prospective blood donors at Mama Yemo Hospital, Kinshasa, Zaïre. The sensitivity of the assays, based on 214 specimens positive by western blot, ranged from 84.6% to 99.1%. The specificity, based on 3664 samples negative by enzyme-linked immunosorbent assay (ELISA) or western blot, ranged from 92.7% to 98.8%. Three readers scored each test result independently; disagreement about test interpretation occurred in 1.2-8.3% of the specimens. There was no correlation between assay performance and assay principle (agglutination or dot immunobinding) or antigen source (viral lysate or recombinant). Assays such as these can be readily implemented in a developing country transfusion centre, where blood screening by ELISA is not practicable.

Agglutination Tests↗