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Biomedical subjects

J Watson

Publications and source records attributed to J Watson.

At least 253 records · Page 14Linked to original sources
PubMed1986

Detection of the c-myc oncogene product in colonic polyps and carcinomas.

The c-myc oncogene has been implicated in the processes of normal cell proliferation and differentiation. Elevated levels of c-myc mRNA and its gene product (p62c-myc), have been detected in a variety of solid tumours and cultured cel lines. Its precise role in normal cell function and in neoplastic transformation and progression has yet to be elucidated. We have used a monoclonal antibody, raised by peptide immunisation, to determine the distribution by immunoperoxidase staining of the c-myc oncogene product in archival specimens of colonic polyps and carcinomas. Samples from 42 patients with colon carcinoma, 24 with benign polyps and 15 normal colon biopsies were examined. Normal colon revealed maximum staining in the mid-zone of the crypts, corresponding to the zone of differentiation and maturation. The staining was predominantly cytoplasmic. Adenomatous polyps revealed the most intense pattern of staining in areas of dysplastic change. Colonic tumours showed a wide range of staining. Well differentiated tumours contained more cytoplasmic p62c-myc than poorly differentiated tumours. These findings suggest that the c-myc oncogene product may play an important role in the evolution of colonic neoplasia.

Adenoma↗
PubMed1986

Localisation of lung cancer by a radiolabelled monoclonal antibody against the c-myc oncogene product.

A set of mouse nonoclonal antibodies against the c-myc oncogene product, a 62,000 dalton nuclear binding protein involved in cell cycle control, has been constructed by immunisation with synthetic peptide fragments. One such antibody, CT14, was radiolabelled with 131I and administered to 20 patients with different malignant diseases. Good tumour localisation was observed in 12 out of 14 patients with primary bronchial carcinoma but not in patients with pulmonary metastases from primary tumours elsewhere. Successfully localised tumours were all 3 cm or more in diameter. Monoclonal antibodies against oncogene products may provide novel selective tools for the diagnosis and therapy of cancer.

Adult↗
PubMed1986

Effects of dietary supplementation on autoimmunity in the MRL/lpr mouse: a preliminary investigation.

The effects of dietary fatty acid supplementation on various disease parameters in the spontaneously autoimmune MRL-mp-lpr/lpr mouse model of systemic lupus erythematosus before onset of disease were investigated. A fat deficient diet was supplemented with the following oils: olive oil, sunflower oil, evening primrose oil (EPO), fish oil, and a fish oil/EPO mixture. The mice receiving a diet enriched with EPO showed an increase in survival, as did those receiving the fish oil/EPO mixture. These results, taken together with those of the other parameters monitored, suggest that EPO may be of benefit in alleviating the murine form of the disease.

Animals↗
PubMed1986

Effect of cardiogenic oscillations on gas mixing during tracheal insufflation of oxygen.

In a previous study using tracheal insufflation of O2 (TRIO) at a rate of 2 l/min, we showed that anesthetized paralyzed dogs could be adequately oxygenated for up to 5 h, albeit with hypercapnia (mean arterial PCO2 approximately 160 Torr). To examine the contribution of cardiogenic oscillations in producing this gas exchange, we studied seven anesthetized paralyzed dogs weighing between 19.6 and 25.5 kg and quantified gas transport by analyzing continuous N2-washout curves in vivo and postmortem. We found that cardiogenic oscillations increase gas mixing roughly fourfold and that this value was independent of insufflation flow rate (0.2-10.0 l/min). Our results lend indirect evidence that, with regard to gas exchange, there are two mechanistically different zones in the lung during TRIO. One zone, located in the more peripheral areas of the lung, is dominated by the effects of cardiac oscillations and molecular diffusion and accounts for the increase in gas mixing found in the alive vs. dead dog. A second zone, close to the insufflated jet of O2, uses convective streaming to produce greater gas mixing at higher flows.

Aerosols↗
PubMed1986

Antenatal evaluation and management in nonimmune hydrops fetalis.

Thirty-eight cases of nonimmune hydrops fetalis were evaluated by detailed real-time ultrasonography and two-dimensional echocardiography. Before ultrasound evaluation, all mothers had a complete blood count, titers for toxoplasmosis, rubella, cytomegalovirus, and herpes (TORCH screen), serum albumin, and a Kleihauer-Betke stain of a peripheral blood smear. Karyotyping of fetal fibroblasts or lymphocytes was performed if these examinations were not diagnostic. A probable etiology was found in 27 (71%) cases. These were chromosome abnormality (nine), pulmonary (three), viral (three), hematologic (two), transient ascites (two), renal (one), skeletal (two), and gastrointestinal (one). Despite extensive antenatal and postmortem examinations, no etiology was found in 11 (28.9%) cases. Although early diagnosis was accomplished in many cases allowing for the option of antenatal therapy, the survival rate was 23.7%, similar to previous reports.

Abortion, Therapeutic↗
PubMed1986

Suppressive effects of visual and facial screening on self-injurious finger-sucking.

Effects of following the self-injurious finger-sucking of two profoundly mentally retarded persons by 5 seconds of either visual or facial screening were compared using an alternating treatments design. The two screening procedures reduced the self-injury more than did a no-treatment control condition. Visual screening was more effective than facial screening with one of the subjects. Subsequently, when the only treatment was visual screening, the contrast in the effect on self-injury between visual screening and no-treatment was further increased. The greatest suppression occurred when visual screening was given in all sessions. Toy play reliably occurred only with appropriate training: The mere provision of toys had no impact on toy play. The effect of toy play on self-injury was equivocal. Possible limitations to the generality of the findings were discussed.

Adolescent↗
PubMed1985

Discussion on the metabolism of c-myc mRNA and protein.

The c-myc gene is expressed in a variety of actively growing cells and tissues including lymphoblastoid cell lines made in vitro by EBV infection (Hamlyn & Rabbitts 1983). The gene is implicated in the derivation of Burkitt's lymphoma because of its association with consistent chromosomal translocations (Dalla-Favera et al. 1982; Neel et al. 1982; Taub et al. 1982) and in, for example, some colon carcinomas where the gene is amplified (Alitalo et al. 1983). To understand the formation of these cancers, we must determine the function of the c-myc protein in the cell. In this discussion we describe some features of c-myc metabolism which indicate that its expression may normally be strictly modulated; it is possible that the potential oncogenic effect of c-myc in various tumours is the result of loss of this ability to modulate its activity.

Burkitt Lymphoma↗
PubMed1985

Prostaglandins, steroids and human mammary cancer.

PGE2 and PGF2 alpha secretion in vitro were measured from tissues of patients with breast tumours and examined in relation to oestrogen receptor status. Prostaglandin secretion was significantly greater from malignant breast tumours than from 'normal' breast tissue or benign tumours. Synthesis of PGE2 by oestrogen-positive and malignant tumours was significantly higher than by oestrogen-negative tumours, suggesting a correlation between prostaglandin E2 and receptor status. Synthesis of PGF2 alpha by the malignant tumour tissues also occurred, but only at relatively low levels and with no significant difference between oestrogen-positive and negative tissues. Exogenous oestrogen in vitro had a significant stimulatory effect on both PGE2 and PGF2 alpha secretion by oestrogen-positive malignant tumour tissues but did not influence oestrogen-negative tumour tissues. Progesterone, on the other hand, had no statistically significant effect on PG secretion by either type of tumour tissue, although the increased levels of PGE2 secreted by oestrogen-positive tumour tissue in the presence of progesterone are unlikely to have arisen by chance. The results support the concept of steroidal influence on excess production of prostaglandins by human malignant breast tumour tissues.

Adult↗
PubMed1985

Tracheal insufflation of O2 (TRIO) at low flow rates sustains life for several hours.

The emergency management of respiratory arrest can be a difficult problem. The authors hypothesized that tracheal insufflation of O2 (TRIO) at low flows could provide adequate oxygenation and sufficient CO2 elimination to sustain life until more definitive (but more difficult to implement) measures could be applied. Therefore, 10 anesthetized, paralyzed dogs (15.9-48.2 kg), initially ventilated with conventional mechanical ventilation (CMV) using room air, were studied. CMV was stopped and a 1- or 5-mm id catheter with a constant flow (V) of O2 ranging from 0.2 to 3.0 l/min was inserted to within 1 cm of the carina. With all flow rates, PaO2 and PaCO2 initially increased with time; the rate of increase of PaO2 was greater and that of PaCO2 was less, with increasing V. In three dogs studied at flow rates of 2.0 or 3.0 l/min, arterial blood gases reached a plateau after about 2 h: pH = 6.87; PCO2 = 164 mmHg; and PO2 = 363 mmHg (mean values). These studies were stopped at between 4 and 5 h, with no dogs showing any signs of cardiovascular or other decompensation. Results in which catheter position was studied indicated that as long as the catheter tip was at or past the carina, gas transport was similar to that observed when the catheter tip was 1 cm proximal to the carina. The authors conclude that TRIO at low flow rates can produce sufficient gas exchange to support life for prolonged periods in apneic dogs.

Animals↗
PubMed1985

Analysis of Photosynthetic Antenna Function in a Mutant of Arabidopsis thaliana (L.) Lacking trans-Hexadecenoic Acid.

Several lines of evidence support the proposal that the unusual chloroplast-specific lipid acyl group Delta3,trans-hexadecenoic acid (trans-C(16:1)) stimulates the formation or maintenance of the oligomeric form of the light-harvesting chlorophyll a/b complex (LHCP). To assess the functional significance of this apparent association we have analyzed LHCP structure and function in a mutant of Arabidopsis thaliana (L.) which lacks trans-C(16:1) by electrophoretic analysis of the protein-chlorophyll complexes and by measurements of chlorophyll fluorescence under a variety of conditions. By these criteria the putative oligomeric form of LHCP appears to be slightly more labile to detergent-mediated dissociation in the mutant. The oligomeric PSI chlorophyll-protein complex, associated with PSI, was also more labile to detergent-mediated dissociation in the mutant, suggesting a previously unsuspected association of trans-C(16:1) with the PSI complex. However, no significant effect of the mutation on the efficiency of energy transfer from LHCP to the photochemical reaction centers was observed under any of the various conditions imposed. Also, the stability of the chlorophyll-protein complexes to temperature-induced dissociation was unaffected in the mutant. The role of trans-C(16:1) is very subtle or is only conditionally expressed.

Journal Article↗
PubMed1985

Fetoscopy in the assessment of unexplained fetal hydrops.

Pure fetal blood samples, obtained fetoscopically from 30 patients with unexplained fetal hydrops at 16 to 32 weeks gestation were investigated for cytogenetic, haematological, biochemical and virological properties. In two patients with oligohydramnios, the fetoscope was introduced transabdominally into the fetal peritoneal cavity and sampling was undertaken from the intra-abdominal portion of the umbilical vein; in all the other patients an umbilical cord vessel was sampled. Ten (33%) of the fetuses had chromosomal abnormalities, one an erythroblastic process, possibly erythroleukaemia, one alpha-thalassaemia and one cytomegalovirus infection. Blood-film abnormalities were seen in 23 (88%) of 26 fetuses that had this examination. Biochemical analysis of fetal plasma was undertaken in 18 fetuses and hypoproteinaemia was found in all cases. One fetus was subsequently found to have a paroxysmal tachyarrhythmia that responded to digitilization. Three (10%) of the fetuses survived.

Adolescent↗
PubMed1985

Alcohol use among migrant laborers in western New York.

A survey of alcohol use among 217 Black and Haitian migrant agricultural workers was conducted in 13 camps in three counties of upstate New York. The orienting hypothesis stated that older, unattached men account for much of the drinking on migrant camps and that older, unattached men have experienced a variety of personal troubles as a result of their drinking. The results of the survey were found to support the initial hypothesis. In camps composed primarily of family groups, social control mechanisms were found to be more highly developed than in camps composed primarily of unattached, isolated men. It was also found that this difference in degree of social control was reflected in differences of drinking behavior. It is suggested that the mechanization of agriculture has become a self-reinforcing process that results in a proportional increase in the use of the homeless and troubled as a source of low-cost agricultural labor.

Black or African American↗
PubMed1984

The origin of the long-wavelength fluorescence emission band (77 degrees K) from photosystem I.

Isolated photosystem I (PSI)-110 particles, prepared using a minimal concentration of Triton X-100 [J. E. Mullet, J. J. Burke, and C. J. Arntzen (1980) Plant Physiol. 65, 814-822] and further subjected to short-term solubilization with sodium dodecyl sulfate (SDS), were resolved into four pigment-containing bands on polyacrylamide gel electrophoresis (PAGE). We have identified these in order of increasing electrophoretic mobility as being (a) CPIa, (b) CPI, (c) the light-harvesting complex of photosystem I (LHC-I), and (d) a free pigment-zone. LHC-I had an absorption maximum in the red at 668-669 nm and a shoulder at 650 nm, which was resolved by its first-derivative spectrum to indicate the presence of chlorophyll b. LHC-I exhibited a 77 degrees K fluorescence emission maximum at 729-730 nm. The 77 degrees K fluorescence emission maxima of CPIa and CPI, excised from the gel, were at 729 and 722 nm, respectively. The LHC-I band, excised from the gel and rerun on dissociating SDS-PAGE, was resolved into two polypeptide doublets of 24-22.5 and 21-20.5 kDa. The CPIa band under similar conditions was resolved into polypeptides of 68, 24, 22.5, 21, 20.5, 19, 15, and 14 kDa; on the contrary, CPI contained only the 68-kDa polypeptide. When intact thylakoids were subjected to "nondenaturing" SDS-PAGE, LHC-I comigrated with an oligomeric form (dimer) of the light-harvesting chlorophyll a/b pigment-protein that preferentially serves photosystem II (LHCP-II). When this combined LHC-I/LHCP-II pigment-protein band was prepared by SDS-PAGE from isolated stroma lamellae, it exhibited a long-wavelength fluorescence band near 730 nm at 77 degrees K. When a similar preparation was obtained from sucrose density gradients containing SDS [J. Argyroudi-Akoyunoglou and H. Thomou (1981) FEBS Lett. 135, 171-181], it was found to be enriched in a 21-kDa polypeptide. The data suggest that the 21-kDa polypeptide of LHC-I is the chlorophyll-containing polypeptide responsible for the long-wavelength fluorescence of LHC-I; other polypeptides in the complex (20.5, 22.5, and 24 kDa) presumably bind chlorophyll and also serve an antennae function.

Chemical Phenomena↗