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Biomedical subjects

M Murphy

Publications and source records attributed to M Murphy.

At least 451 records · Page 25Linked to original sources

Alternative technique for photographing the corneal endothelium with a conventional photo slitlamp.

Photographs of the corneal endothelium are taken usually with special purpose cameras or by using the Holden-Zantos technique with a conventional photo slitlamp. The latter method requires the camera back to be mounted on the photo slitlamp eyepiece and the resulting slide to be magnified by being rephotographed with a slide copier. This report describes another way of obtaining the requisite magnification using a teleconverter placed before the camera back mounted in its usual position and special darkroom techniques exploiting the properties of Kodak Technical Pan, a fine grain, variable contrast film.

Cornea↗

The 65,000-Mr DNA-binding and virion trans-inducing proteins of herpes simplex virus type 1.

The possible identity of the herpes simplex virus type 1 (HSV-1) 65K (65,000-Mr) virion protein which stimulates transcription from immediate-early genes with the HSV-1 65K DNA-binding protein was investigated. The two proteins were found to be distinct by the three separate criteria of immunological reactivity, tryptic peptide fingerprinting, and mobility in two-dimensional gels. Using HSV-1/HSV-2 intertypic recombinants and a serotype-specific antiserum, we located the gene encoding the 65K DNA-binding protein between coordinates 0.574 and 0.682 on the HSV-1 genome. The protein is posttranslationally modified by phosphorylation. In crude extracts of HSV-1-infected cells the 65K trans-inducing protein did not detectably bind to double-stranded calf thymus DNA under the conditions of our assay.

Antigens, Viral↗

Relative risk estimation from vital statistical data: validation, a pitfall and an alternative method.

A previously described method of obtaining an estimate of relative risk from routinely available data was applied to data on cigarette consumption and lung cancer mortality to test its validity. Some shortcomings of the method were noted and an alternative approach using weighted logistic regression gave results closer to those predicted on the basis of other studies, without the disadvantages of the original technique.

Female↗

Rumen and total diet digestibilities in lactating cows fed diets containing full-fat rapeseed.

Effects of full-fat crushed rapeseed (0, 1, or 2 kg/d) on rumen and total digestion, rumen biohydrogenation, and rumen microbial protein synthesis were studied in lactating cows. Rumen digestibilities (%) of DM, NDF, and cellulose were 52.1, 46.1, and 51.8, respectively, for control. Rapeseed decreased rumen and total DM digestibilities and proportion of DM digested in the rumen. Rumen digestibility of cellulose was decreased by rapeseed, but this was apparently compensated by hindgut fermentation. Dry matter, NDF, and hemicellulose digestibilities were compensated at 1 kg but not at 2 kg/d. Biohydrogenation of 18:1 fatty acids increased with increasing dietary fat, whereas that of 18:2 and 18:3 was 85% on all diets. Fatty acid digestibility was not different among diets. Microbial nitrogen in the duodenum increased from 142 g/d for control to 191 g/d for 1 and 2 kg/d. Efficiency of microbial protein synthesis (grams of microbial nitrogen per kilogram organic matter apparently digested in the rumen) was 17.3, 24.8, and 26.6 for 0, 1, and 2 kg/d. Slow release of fat from crushed rapeseed minimized negative effects on rumen metabolism; 1 to 2 kg/d of full-fat crushed rapeseed may be fed to lactating cows without detrimental metabolic effects.

Animals↗

Tumor necrosis factor and lymphotoxin induce differentiation of human myeloid cell lines in synergy with immune interferon.

We show that the cytotoxins tumor necrosis factor (TNF) or lymphotoxin (LT), at concentrations of approximately 10(-11) M induce monocytic differentiation of human myeloid cell lines. After 5 d of culture in the presence of rTNF and LT, a significant proportion of the myeloid cell lines express monocyte differentiation antigens and ANAE activity, and become able to reduce nitroblue tetrazolium (NBT) and mediate low levels of ADCC against tumor target cells. These markers of differentiation, however, are maximally induced when rIFN-gamma, at concentrations as low as 4 U/ml, is present simultaneously with the cytotoxins, and the two classes of cytokines act synergistically to induce terminal differentiation. The appearance of monocytic antigens is accompanied by acquisition of morphology and other functional properties of mature monocytic cells, such as chemiluminescence and phagocytosis, and by expression of FcR for monomeric IgG. A decrease in cell proliferation accompanies induced differentiation, and is not due to the cytotoxic properties of TNF or LT, as indicated in simultaneous analysis of surface phenotype and cell cycle. The lack of cytotoxicity of TNF on the HL-60 cell line is also demonstrated by the enhancing effect of TNF on HL-60 cell growth and nucleoside uptake in the first 2 d of culture. These data show that the cytotoxins TNF and LT mediate complex effects on cells of the myelomonocytic lineage and, in synergy with IFN-gamma, can fully induce immature myeloid cells to differentiate into cells with phenotypic, functional, and proliferative characteristics of terminally differentiated myelomonocytic cells.

Antibody-Dependent Cell Cytotoxicity↗

Gamma interferon and lymphotoxin, released by activated T cells, synergize to inhibit granulocyte/monocyte colony formation.

We have shown that lymphocytes stimulated by PHA produce colony-forming unit of granulocyte/monocyte (CFU-GM)-stimulating and -inhibiting activities, IFN-gamma, and lymphotoxin (LT). IFN-gamma is necessary for inhibition of CFU-GM by PHA-conditioned medium (CM), as shown by experiments in which removal of IFN-gamma from PHA-CM abrogated inhibition. However, experiments in which rIFN-gamma was added to IFN-gamma-depleted PHA-CM revealed the presence, in PHA-CM, of other factors that act in synergy with IFN-gamma to inhibit CFU-GM. Fractionation of PHA-CM on a Sephadex G-100 column was used to separate IFN-gamma and LT. Colony-inhibiting activity was eluted in fractions that contained both IFN-gamma and LT activities, identifying LT as a factor present in PHA-CM that synergizes with IFN-gamma to inhibit CFU-GM. Treatment of PHA-CM with mAb against either IFN-gamma or LT completely abrogated the colony-inhibiting activity, demonstrating a requirement for both lymphokines in PHA-CM-induced inhibition of CFU-GM. Experiments using rIFN-gamma and preparations of purified LT confirmed that neither lymphokine alone, when added to bone marrow cells at the concentrations present in PHA-CM, strongly inhibited day 7 or day 14 CFU-GM, but that the two lymphokines, added together, behaved synergistically to inhibit CFU-GM by up to 70%. The inhibition observed using purified preparations of lymphokines shows that synergy between IFN-gamma and LT is sufficient to explain PHA-CM-induced inhibition of CFU-GM. Our findings suggest that activated T cells regulate hematopoiesis through the release of inhibitory as well as stimulatory factors, and that the simultaneous production of IFN-gamma and LT may represent a mechanism of suppression of hematopoiesis in the cases of bone marrow failure associated with the presence of activated T cells.

Animals↗

Studies of Doppler aortic flow velocity during supine bicycle exercise.

Although Doppler echocardiography is useful in the assessment of left ventricular function at rest, little information is available on the application of this technique during exercise. Consequently, Doppler aortic flow studies were performed in 17 young normal subjects during and after supine bicycle exercise. The purposes of the study were to determine the feasibility of recording Doppler aortic flow velocity with a suprasternal notch transducer during exercise and to assess the changes in normal aortic flow velocity parameters during exercise and early recovery. Each subject exercised until fatigue; mean duration of exercise was 10 minutes. Heart rate increased from a mean of 69 beats/min at control to 159 beats/min at peak exercise. On average, aortic peak flow velocity increased by 45% from control, reaching its maximum at 2 minutes after exercise. Ejection time decreased by 34% during exercise, being shortest at peak exercise. Heart rate, peak flow velocity and ejection time had not returned to normal by 10 minutes after exercise. Aortic flow velocity integral (a relative measure of stroke volume) decreased by 10% at peak exercise (p less than 0.05) compared with control, but had returned to control at 2 minutes after exercise. Despite mild aliasing, increased spectral dispersion, faster heart rates and increased respiratory rate during maximal exercise, aortic flow velocity measurements could be recorded using the suprasternal technique. These baseline Doppler exercise data should be useful in further studies of exercise hemodynamic changes in patients with heart disease.

Adolescent↗

Paget's disease.

Explore the source record for details and available documents.

Australia↗

Rett syndrome--natural history in 70 cases.

We evaluated, at our institute, 70 females with Rett syndrome between 2 1/2 to 34 1/2 years old. This provided an opportunity of observing the natural history of this condition. The evolution of a subacute encephalopathy of very early onset, maximizing in the second year of life, with slow recovery and devastating sequelae, was recognized. The hyperorality, visual auditory and tactile agnosia with aphasia and seizures resembled symptoms described in human Kluver Bucy syndrome. Over interpretation of behavioral abnormalities as seizures was common. Scoliosis was not a necessary concomitant of age. A consistent biochemical or neurophysiological abnormality was not detectable in understanding the cause and pathogenesis of this disease process. Life span appears to be unaffected though life tables have not yet been established.

Adolescent↗

Rett syndrome and the electroencephalogram.

The EEG is almost always abnormal in patients with Rett syndrome. This is demonstrated in a study based upon 230 EEG records obtained from 44 patients. Rhythmical slowing (mostly 3-5/sec) represents the most common EEG abnormality (30 patients). Diffuse, scattered or bilateral-synchronous spikes or sharp waves were found in 22 patients. Slow spike-wave complexes were present in 9 patients. With advancing age, the EEG abnormalities tend to decline and ill-defined low voltage records may develop. These changes may parallel an intrinsic disease course with an early active phase followed by a phase of residual impairment.

Brain↗

Chromosome studies in 10 patients with the Rett syndrome.

Chromosomes of white blood cells from 10 girls with the Rett syndrome, 9 of their mothers and 17 unrelated controls (5 girls and 12 women) were examined for the presence of the fragile site on Xp22 under different culture conditions. Six of the 10 Rett patients were fra(X)(p22) positive while 4 failed to express this fragile site. In the 6 patients expressing the fragile site it was present in 1 to 3% of all cells. Similarly, 5 of the mothers and 6 of the control women showed this fragile site, with a frequency of 1 to 9%. Concordance analysis showed that in the 9 mother-daughter pairs examined, 5 had concordant results while 4 of the pairs were discordant. These findings are very similar to those found in non-Rett individuals by ourselves and other investigators. These data agree with published findings that fra(X)(p22) is a common fragile site in normal individuals. Therefore, we conclude that the incidence of the Xp22 fragile site in the Rett syndrome does not differ from that found in various non-Rett individuals, including normal persons. This indicates to us that fra(X)(p22) cannot serve as a chromosomal marker for the Rett syndrome.

Adult↗

Balloon angioplasty of coronary bifurcation lesions: the kissing balloon technique.

Initial experience with the technique of "kissing balloon" angioplasty is described in 52 patients undergoing coronary angioplasty. Guiding catheters employing both the femoral and brachial approach were used in all but two of the coronary angioplasties and, in addition, the bilateral femoral approach was used in the renal and peripheral angioplasties. Initial success was achieved in 51 (98%) patients. Abrupt closure requiring urgent coronary revascularization occurred in one patient six hours following the completion of the procedure. Another patient developed a new Q-wave on the electrocardiogram and moderate elevation of CPK-MB fraction following the procedure due to loss of a diagonal branch. No deaths occurred in this series. Angiographic restenosis developed in ten patients. In the recurrence group, five had repeat kissing balloon angioplasty, two had repeat single vessel angioplasty, and three patients chose elective surgical revascularization. Based on our experience, the technique of kissing balloon coronary angioplasty can be performed safely utilizing the brachio-femoral technique. The risk of major side branch occlusion can be minimized with this technique and the overall complication rate does not significantly differ from that of our experience in single vessel coronary angioplasty. Patient selection criteria are based upon the angiographic relationship of the major branch to the side branch and is important in determining the initial and long-term success of this technique.

Adult↗

Demographic event history analysis: a selective review.

This is a selective review of the literature concerning demographic event history analysis. "We have attempted to emphasize work that we consider to be particularly important or innovative, to note some of the difficulties that may arise with the use of event history analysis, and to point to several substantive areas where research is still poorly developed."

Data Collection↗

Natural killer (NK) cell-derived hematopoietic colony-inhibiting activity and NK cytotoxic factor. Relationship with tumor necrosis factor and synergism with immune interferon.

We characterize the natural killer (NK) cell colony-inhibiting activity (CIA) produced in supernatants from cultures of human peripheral blood lymphocytes (PBL) with NK-sensitive target cell lines, and study its relationship with NK cell-derived cytotoxic factor (NKCF). Using monoclonal antibodies (mAb) specific for NK cells or other lymphocyte populations, we unambiguously identify NK cells as the only PBL subset able to produce both NKCF and NK-CIA. We present functional and biochemical data suggesting that NKCF and NK-CIA represent the same molecule: (a) a highly significant positive correlation exists between the quantity of NKCF and NK-CIA in supernatants independently produced by different PBL subsets; (b) both NK-CIA and NKCF are induced by culture of PBL with NK-sensitive, but not with NK-insensitive cell lines, and with HLA-DR+ bone marrow cells; (c) both NKCF and NK-CIA are absorbed on the same cell lines or bone marrow cell types; (d) the two activities coelute in the same gel filtration fractions; (e) D-mannose-6-phosphate blocks both NKCF and NK-CIA activity, and prevents their absorption by K562 cells; and (f) both NKCF and NK-CIA activity are lost after 2 d at 37 degrees C. The NK-CIA-containing preparations are devoid of antiviral activity, and antiinterferon (anti-IFN) antibodies do not block the inhibitor activity of NK-CIA. The effect of NK-CIA on day 14 (early) colony-forming units of granulocytes and macrophages (CFU-GM) is synergistic with that of IFN-gamma, and this synergy is also evident on day 7 (late) CFU-GM growth. A combination of NK-CIA and IFN-gamma suppresses late CFU-GM, at concentrations of the two lymphokines that are completely ineffective when used independently. No synergy between NK-CIA and IFN-alpha or -beta was observed, due to a direct inhibitory effect of these two IFN types on late CFU-GM. Antibodies specific for tumor necrosis factor (TNF), but not those specific for lymphotoxins, inhibit both NK-CIA and NKCF activity in the NK cell-derived supernatant. Recombinant TNF, in the range of concentrations corresponding to that of the cytotoxic activity on L-929 cells present in supernatants, mediated both NKCF and NK-CIA activity.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗