Search PubMed⌕ Search

Biomedical subjects

J Watson

Publications and source records attributed to J Watson.

At least 289 records · Page 16Linked to original sources
PubMed1982

A new device and method for rapid emergency pacing: clinical use in 10 patients.

A new multipurpose transthoracic pacing device is described that will simultaneously enable transthoracic electrode insertion, intracardiac drug infection, and blood sample removal for blood gas determination, all via a single myocardial needle insertion. The device proved efficacious and safe in trials in an animal model. In clinical use in 10 emergency room patients with brady-asystolic cardiac arrest, pacing was achieved in all 10 with one short-term survivor. Median insertion time was 30 seconds. Median threshold in 6 patients was 2.5 mA (1 to 6). This new device enables reliable and rapid emergency treatment of brady-asystolic cardiac arrest.

Adult↗
PubMed1982

Genetic control of responses to Trypanosoma cruzi in mice: multiple genes influencing parasitemia and survival.

Inbred strains of mice can be divided into two groups based on the level of parasitemia which develops after injection with 10(3) trypomastigotes of Trypanosoma cruzi (Peru). Strains which developed parasitemias of greater than 10(7) trypomastigotes per ml by day 17, including C3H/HeJ, BALB/c, and CBA/N mice, were termed high parasitemia strains. Low parasitemia strains, including C57BL/6J and DBA/2J mice, developed parasitemias of less than 5 x 10(6) trypomastigotes per ml by day 17 of infection. Congenic mice from C57BL/10J, C57BL/6J, and BALB/c backgrounds which differed at the H-2 region were injected with 10(3) trypomastigotes to determine the effect of the H-2 locus on response to infection. The H-2 locus had no effect on the level of parasitemia attained during infection. However, one strain, B10.S (H-2s), was unusual in that most of the mice survived infection. The results of infection of F1 hybrid progeny with T. cruzi (Peru) suggest that the low parasitemia response in inherited in a dominant manner and that survival may be influenced by several other genes. The response to T. cruzi infection in inbred mice, as measured by parasitemia and survival time, was influenced by several genes. One or more genes, located outside the H-2 region, were involved in regulating the level of parasitemia reached during infection. Another H-2-linked gene(s) was involved in survival of the infection and appeared to be unique to the H-2s haplotype.

Animals↗
PubMed1981

Bone marrow transplantation for acute leukaemia and severe marrow aplasia: an analysis of five patients.

Five patients, three with severe aplasia and two with acute leukaemia have been treated by bone marrow transplantation (BMT). Four are alive and well with excellent graft function. One showed engraftment but died of acute graft-versus-host disease (GVH); this patient and his donor were hepatitis B antigen positive. Three show evidence of mild chronic GVH, two patients requiring control by immunosuppressive therapy. Bone marrow transplantation (BMT) has now become an established method of treatment in severe aplasia and in acute leukaemia and our results serve to emphasise this. The clinical and organisational problems associated with BMT are discussed.

Adolescent↗
PubMed1981

Right atrial catheters for long-term venous access.

Thirty-two Hickman central venous catheters were placed in patients suffering mainly from blood disorders. The catheters remained in situ for an average of 64 days. In 20 patients the catheters were removed either because they were no longer needed (14) or at death (6). In five patients they are still in position. Complications in seven patients led to the catheter being removed and these included four patients with catheter related sepsis. The use of these catheters allows safe long-term access to the venous circulation even in the neutropenic, immunosuppressed patient.

Bacterial Infections↗
PubMed1981

Elderly in Canada: integrated care.

Care of the elderly is perhaps one of the more acute areas of need in the health service in the United Kingdom. By comparison, Canada does not have such a high proportion of elderly people, but John Watson found a more positive approach to "keeping people at their highest level of function" during a visit to the Baycrest Centre for Geriatric Care in Toronto. He found that the centre, which was set up in the last ten to 20 years, has some facilities which are not generally offered in this country.

Comprehensive Health Care↗
PubMed1981

In vitro analysis of allogeneic lymphocyte interaction. V. Identification and characterization of two components of allogeneic effect factor, one of which displays H-2-restricted helper activity and the other, T cell-growth factor activity.

An allogeneic effect factor (AEF) derived from mixed lymphocyte reaction (MLR) cultures of alloactivated A.SW (H-2s) responder T cells and irradiated A/WySn (H-2a) stimulator spleen cells helps an in vitro primary anti-erythrocyte plaque-forming cell PFC response of BALB/c nude spleen cels and also A/WySn but not A.SW T cell-depleted spleen cells. AEF activity is adsorbed by anti-Ik and anti-I-Ak but not by anti-I-Jk, anti-I-ECk, and anti-Is. Gel filtration of ACA 54 resolves AEF into two main components that which appear in the 50,000- to 70,000-mol wt (component I) and 30,000- to 35,000-mol wt (component II) regions, respectively. Component I has a mol wt of 68,000, elutes from DEAE-Sephacel at 0.05-0.1 M NaCl, and has an isoelectric point (pI) of 5.8. It helps A/WySn but not A.SW B cells and, therefore, is H-2 restricted. Component II is not H-2 restricted, because it helps both A.SW and A/WySn B cells. It also stimulates (a) the growth of a long-term cytotoxic cell line in vitro, (b) Con A-induced thymocyte mitogenesis, and (c) the generation of cytotoxic T cells. The latter three properties of component II are not shared by component I. In addition, component II elutes from DEAE-Sephacel at 0.15-0.2 M NaCl and has a pI of 4.3 and 4.9. Ia determinants and Ig VH, CH, L-chain, and idiotypic determinants are not present on either component I or component II. The properties of component II are identical to that of a T cell growth factor produced by Con A-stimulated spleen cells. It is suggested that the H-2-restricted component I of AEF might be an MLR-activated responder T cell-derived Ia alloantigen receptor.

Animals↗
PubMed1981

Isolation of an Hfr donor of Pseudomonas aeruginosa PAO by insertion of the plasmid RP1 into the tryptophan synthase gene.

A derivative of the IncP-1 plasmid RP1, temperature-sensitive for maintenance, was inserted into the Pseudomonas aeruginosa chromosome by selection for a plasmid marker (carbenicillin resistance) at non-permissive temperature. In one strain, PAO 1000, the plasmid was stably integrated in the trpA, B gene cluster mapped at 27 min, as shown by the following evidence. (i) Trp+ transductants lost all plasmid markers. (ii) Cleared lysates of PAO 1000 showed no plasmid band typical of the autonomous RP1 in agarose gel electrophoresis. (iii) No transfer of carbenicillin resistance by PAO 1000 was detectable. (iv) PAO 1000 mobilised the chromosome from an origin at, or very near, the plasmid insertion site with high frequency (recovery of proximal markers greater than or equal to 10(-3) per donor). Matings on the plate with and without interruption of conjugation showed that chromosome transfer was unidirectional. (v) Recombinants from PAO 1000-mediated crosses did not inherit plasmid markers or the trpA, B mutation. A derivative of PAO 1000 was obtained which had lost the Hfr property and all plasmid markers except carbenicillin resistance. This strain (PAO 1001), when carrying the autonomous RP1 plasmid, was capable of unidirectional chromosome mobilisation like PAO 1000, but with 50-fold lower efficiency. We propose that integration of the temperature-sensitive RP1 plasmid in PAO 1000 occurred via transposition of Tn1, the element specifying carbenicillin resistance.

Conjugation, Genetic↗
PubMed1981

Comparative mitogenic effects of herpes simplex virus and mycoplasma on murine lymphocytes.

Previous work indicated that herpes simplex virus type 1 (HSV-1) is a mitogen for mouse spleen cultures, as monitored by uptake of 3H-thymidine. We observed variable responses of mouse spleen cultures to different viral preparations. The variable responses, which did not follow normal dose-response relationships, were not due to HSV-1 strain differences, altered response kinetics or the presence or absence of defective viral particles, but to mycoplasma contamination of viral stocks. Mycoplasma-free (MF) HSV-1 stocks were prepared by transfection of MF NHF cells with HSV-1 DNA. MF HSV-1 infection of spleen cultures resulted in a five- to sixfold stimulation of DNA synthesis and stimulation of a polyclonal antibody response. Heat treatment (56 degrees C for 1 h) and antibiotics were used to distinguish mycoplasma and HSV-1-induced spleen culture mitogenic responses. The mycoplasma-induced mitogenic activity was found to be heat labile and sensitive to gentamicin and chloramphenicol. In contrast, the HSV-1 induced response was not affected by gentamicin or chloramphenicol and heat treatment resulted in only a 50% loss of activity.

Animals↗