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Biomedical subjects

J White

Publications and source records attributed to J White.

At least 523 records · Page 29Linked to original sources
PubMed1983

Nopaline Ti-plasmid, pTiT37, T-DNA insertions into a flax genome.

The FT37/1 plant tumor line induced on flax epicotyls by T37, a nopaline strain of Agrobacterium tumefaciens, contains multiple copies of the pTiT37, T-DNA. There are three to four distinct full-length insertions and one tandem insertion. Allowing for the different copy numbers of the inserts, this amounts to seven to eight T-DNA copies per genome unit. The genome unit in this case is the haploid DNA value (7 X 10(8) bp) which predicts a T-DNA copy number of 14-16 per diploid cell. Three novel types of abnormal insertion are also present. FIL (one copy per basic genome) comprises 3.04-4.47 kb of T-DNA derived from the left end, with a normal left border and an abnormal right border. FIR (four copies per basic genome) comprises 5.88-6.47 kb of T-DNA derived from the right end, with a normal right border and an abnormal left border. The third abnormality is represented by fragment "X," a HindIII fragment of 4.90 kb which contains homology with several noncontiguous regions of the T-DNA and which may derive from a tandem insertion. Of the two possible left-border sites (primary and secondary) in which fusion with plant DNA sequences has been observed, only the primary is used.

Chromosome Mapping↗
PubMed1983

A comparison of craniofacial growth between two colonies of marmosets (Callithrix jacchus).

General and craniofacial measurements from young marmosets in a recently established Australian colony are presented and compared with similar data published for a long-established colony in the United Kingdom. Statistically significant differences between the colonies were those associated with large error variances, suggesting difficulties in locating certain landmarks rather than real differences in growth. Thus, direct comparison can be made between craniofacial growth studies conducted at these two different marmoset colonies.

Analysis of Variance↗
PubMed1983

Internal mammary implantation: the need for revival of a simple technique.

Available statistics on breast cancer indicate a high frequency of positive internal mammary nodes, which is associated with decreased five-year survival rates. The close proximity of the majority of internal mammary nodes (87 percent within 1 cm) to the internal mammary vessels makes them easily accessible to high-dose intravascular continuous irradiation by afterloading radioactive ribbons (iridium 192) in the internal mammary vessels that are surgically exposed. This is a simple technique that can be carried out at the time of mastectomy or as a separate procedure, either as a primary radiation modality, for post-XRT recurrence, or as a boost in combination with conventional parasternal radiation therapy. The step-by-step technique, indications, need for revival, and future implications are presented.

Brachytherapy↗
PubMed1982

Combination chemotherapy, radiotherapy, and BCG immunotherapy in limited small-cell carcinoma of the lung: a Southwest Oncology Group Study.

From November 1976 to March 1979 the Southwest Oncology Group treated 298 patients with limited (disease confined to the chest and encompassed by one radiotherapy port) small-cell carcinoma of the lung with combination chemotherapy and radiotherapy with or without BCG immunotherapy. Two induction chemotherapy programs were utilized: (1) cyclophosphamide, vincristine, methotrexate, fluorouracil; or (2) cyclophosphamide, doxorubicin, and vincristine. Patients received 4500 rads of radiation therapy to the bulk primary tumor and 3000 rads to whole brain followed by maintenance chemotherapy. One-half of all the patients were randomized to receive one vial (5 x 10(8)) of high viability Pasteur BCG by scarification technique given on days 8 and 15 of each 21--28 day treatment cycle. Increased granulocytopenia accompanied the addition of BCG immunotherapy. Patients receiving BCG achieved a response rate of 49% vs. those patients not receiving BCG of 44% (P = 0.579). Median response duration was 40 weeks for the BCG arms and 38 weeks for the arms without BCG; survival was no different, 42 weeks for the BCG arms vs. 50 weeks for the arms without BCG. In patients who responded to therapy and survived longer than one year, those who continued to receive BCG therapy demonstrated a slight, yet significant, survival benefit over those patients not receiving BCG (93 weeks vs. 81 weeks, P = 0.03). It appears that BCG immunotherapy has no beneficial effect on response rate, duration of response, or survival in programs using chemotherapy and radiotherapy for control of limited small-cell carcinoma of the lung except in this small group of long-term survivors.

Antineoplastic Agents↗
PubMed1982

Survey of pulmonary tuberculosis in south and west Wales (1976-8).

In routine clinical practice 20% of patients with pulmonary tuberculosis were treated with the regimen recommended by the British Thoracic Association after the British trial of short-course chemotherapy. Despite the use of several regimens that could be considered inadequate, no patients from the survey within south and west Wales appears to have relapsed yet. Deaths from pulmonary tuberculosis continue at the same rate as 10 years ago. Patient default remains a difficult problem even with modern, less toxic, short-course regimens.

Adolescent↗
PubMed1982

Membrane fusion activity of influenza virus.

A simple assay is described to monitor fusion between fowl plague virus (FPV, an avian influenza A virus) and liposomes which allows the simultaneous quantitation of both lytic and non-lytic fusion events. As in fusion between viruses and the plasma membrane and in FPV-induced cell-cell fusion, the reaction only occurs at pH 5.5 or below, and it is fast, highly efficient, and essentially non-lytic when fresh virus and liposomes are used. The fusion occurs over a broad temperature range, and has no requirement for divalent cations. The fusion factor of influenza virus is a hemagglutinin (HA) spike which protrudes from the virus membrane and which is also responsible for virus binding to the host cell. The finding that fusion occurs as efficiently with liposomes containing or lacking virus receptor structures, further emphasizes the remarkable division of labor in the HA molecule: the receptor-binding sites are located in the globular HA1 domains and the fusion activation peptide is found at the N-terminal of HA2 in the stem region of the protein. The mechanism of fusion is discussed in terms of the three-dimensional structure of the HA and the conformational change which the protein undergoes at the fusion pH optimum.

Animals↗
PubMed1982

Antigen presentation by Ia+ B cell hybridomas to H-2-restricted T cell hybridomas.

The Ia+, H-2d BALB/c lymphoma cell line L10.A 2J was fused to T cell-depleted spleen cells from mouse strains bearing other H-2 haplotypes. A portion of the selected hybrids expressed Ia antigens of the normal spleen cell partner in the fusion as evidenced by their presentation of various antigens to a set of antigen-specific I-region-restricted T cell hybridomas. Three cloned hybrids were studied in detail. Antigen presentation was shown to be inhibited specifically by monoclonal anti-Ia antibodies. Both I-A and I-E molecules were expressed, including in the one case examined hybrid I-A and I-E molecules between the H-2d and H-2b haplotypes. These Ia+ B cell hybridomas provide a useful set of tools for studying the role of I-region-encoded molecules in antigen presentation to T cells.

Antibody Formation↗
PubMed1982

Inhibition of Semliki forest virus penetration by lysosomotropic weak bases.

The effect of five lysosomotropic weak bases (chloroquine, amantadine, tributylamine, methylamine and NH4C1) on Semliki Forest virus (SFV) infection has been studied in BHK-21 cells. When present at concentrations equal to or greater than 0.1, 0.5, 2, 15 and 15 mM respectively, the agents inhibited SFV infection by more than 90%. The effect was reversible and involved a process occurring within the first 60 min of virus-cell contact. The agents did not have a direct virucidal effect nor did they affect virus binding to the cells, receptor-mediated endocytosis of prebound virus, intracellular distribution of virus after endocytosis, or the low pH-induced membrane fusion activity of the virus spike glycoproteins. The step blocked by chloroquine and NH4C1 occurred intracellularly and was identified as the release of the virus nucleocapsid into the cytoplasm or the uncoating process. On the basis of these results, our previous studies on SFV entry, and the known effects of lipophilic amines on lysosomes, we conclude that the agents affect entry by a common mechanism: they prevent the transfer of the virus nucleocapsid into the cytoplasm by increasing the lysosomal pH above the critical value needed to trigger a low pH-dependent fusion reaction between the membranes of the lysosome and the virus.

Amantadine↗
PubMed1982

A clinical trial of a bead bed system for the prevention of pressure sores in elderly orthopaedic patients.

This paper summarizes the results of the trial of the Beaufort Bead Bed system designed to reduce the incidence and severity of pressure sores. Elderly orthopaedic admissions were allocated alternately to the Beaufort system and to the usual trolley, table and bed surfaces, and followed from admission to hospital until separation. The incidence of pressure sores was 15.6% in the 32 'trial' patients, which was significantly less than the 48.8% in the 43 'control' patients, as was the mean maximum diameter of the pressure sores incurred: 6.4 mm for the 'trials' as against 29.5 mm for the 'controls'. In particular the trial group were free from pressure lesions to the heel, which affected 32.6% of the control group. The groups were well matched on a variety of criteria on admission, and we conclude that the Beaufort system successfully reduces the incidence and severity of pressure sores for elderly orthopaedic patients. The system--renamed recently the 'Neumark-Macclesfield Support System'--is now in regular and satisfactory use.

Aged↗
PubMed1982

A method for using microspheres to measure muscle blood flow in exercising rats.

A catheter-implantation procedure allowing use of the radiolabeled microsphere (MS) technique for measuring skeletal muscle blood flow (BF) in rats during high-speed treadmill running was desired. Attempts to use existing procedures were unsuccessful. We found that Silastic catheters (0.02 in. ID X 0.037 in. OD) placed in the ascending aorta (for MS infusions) and the renal artery (for reference sample withdrawal) minimized these exercise performance problems. It was then necessary to establish that aortic MS infusions result in good MS-blood mixing. We tested the method with the following: 1) the radioactivities found in reference withdrawal samples taken from two locations in the aorta were compared after left ventricular (LV) infusion and after aortic infusion; 2) BFs to bilaterally paired tissues were compared in anesthetized and conscious rats with LV and aortic infusions; 3) the distribution of MSs in the muscles was studied histologically; and 4) BFs in bilaterally paired tissues were compared in rats with aortic MS infusions during treadmill running. The results indicate that 1) the percent difference between the radioactivities found in the proximal and distal reference withdraw samples was the same for LV and aortic MS infusions; 2) BF to bilaterally paired tissue samples was the same with both LV or aortic MS infusions; 3) the MSs were distributed uniformly within muscles, and MS aggregation was not a significant problem; and 4) BFs to bilaterally paired tissue samples were the same in exercising rats. We conclude that this technique can be used to measure muscle BF in rats running on a treadmill.

Animals↗
PubMed1982

Antithymocyte globulin in cadaver renal grafts: prophylaxis and antirejection therapy with three different preparations.

Three different preparations of antithymocyte globulin were used to treat recipients of cadaver kidney transplants. Twenty patients received Connaught Institute/Armand-Frappier ATG prophylactically beginning on the day of grafting and achieved superior graft and patient survival compared to 18 concurrent controls. Pressimmune as a 5-day course was able to reverse steroid resistant rejections in 20 of 31 recipients as was ATGAM in three of six treated patients receiving it for 10 days. These short courses were associated with a 16% early and a 10% late relapse rate. The combination of high steroid therapy, maintenance azathioprine and ATG was associated with an infection rate of 22%.

Antilymphocyte Serum↗
PubMed1982

Nasendoscopy: significant refinements of a direct-viewing technique of the velopharyngeal sphincter.

The need for a three-dimensional record of velopharyngeal sphincter function in patients with craniofacial anomalies and speech problems is discussed. A refined split-screen video technique using color nasendoscope image, lateral video-fluoroscopy, and synchronous speech recording with the patient awake and in supine position is described. A special signal processor is used to position the color nasendoscopy image. The examination is recorded on 1-in. videotape. The technique allows three-dimensional appraisal of sphincter function with direct viewing and enables assessment of a range of abnormalities, assessment of the effectiveness of pharyngoplasties, and prediction of speech deformities and their management following midface craniofacial surgery.

Endoscopes↗