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Biomedical subjects

A Morris

Publications and source records attributed to A Morris.

At least 253 records · Page 14Linked to original sources
PubMed1983

Interferon with novel characteristics produced by human mononuclear leukocytes.

Treatment of human peripheral blood mononuclear leukocytes with phytohaemmaglutinin and the tumour promoter teleocidin, results in the production of large amounts of interferon-gamma and significant amounts of a novel interferon-like substance which we tentatively class as interferon-delta. This novel interferon type possesses all the important characteristics of classical interferon but, of various cell types tested, has antiviral activity only in trisomy-21 human fibroblasts. It differs decisively from previously identified interferon types in its antigenic, biological and physicochemical properties.

Animals↗
PubMed1981

Seasonal changes in perinatal vitamin D metabolism: maternal and cord blood biochemistry in normal pregnancies.

Two groups of white, primiparous women and their babies were studied: one group in April 1979 and the other in September 1979. They were selected to be as near normal as possible. In each case maternal and cord blood samples were taken at delivery and analysed for serum 25-hydroxycholecalciferol (25-OHD), calcium, magnesium, phosphate, alkaline phosphatase, total protein, and albumin. Follow-up was by questionnaire at 6 weeks. The study showed a highly significant increase in maternal and cord serum 25-OHD levels in September. The few mothers who had taken vitamin D supplements had significantly higher serum 25-OHD values. Some of the unsupplemented women studied in April had low serum 25-OHD levels suggesting that oral vitamin D supplements should be given to pregnant white women in Britain, at least during the winter.

Calcifediol↗
PubMed1980

Cytochalasin D does not produce net depolymerization of actin filaments in HEp-2 cells.

The altered morphology, disappearance or 'disruption' of actin filaments (microfilaments) in cells treated with cytochalasin has sometimes been attributed to depolymerization of filamentous actin (F-actin) to its globular subunit (G-actin), but attempts to confirm that mechanism have been inconclusive. Treatment of purified actin filaments with cytochalasin B (CB) decreased their viscosity, consistent with depolymerization, which was not, however, revealed by electron microscopy, although the filaments appeared abnormal. CB also increased the ATP-ase activity of F-actin, suggesting that it had been destabilized, while actin filaments in the acrosomal process were not depolymerized. CB or cytochalasin D (CD) can dissolve actin gels (reviewed in ref. 7, see also refs 8 and 9) without depolymerizing their filaments. The 'disrupted' actin structures in CD-treated cells bound heavy meromysin, indicating that at least some of the cellular actin was filamentous. Using a rapid assay for G- and F-actin in cell extracts, based on the inhibition of DNase I, we have found that neither short-nor long-term exposure of HEp-2 cells to CD produce net depolymerization of actin filaments.

Actins↗
PubMed1980

The isolation and characterization of a clonally related series of murine retrovirus-infected mouse cells.

Starting with cloned NIH 3T3 mouse cells we have isolated a series of related lines infected with the Kirsten murine sarcoma/leukaemia (MSV/MLV) virus complex. These lines exhibit all three possible infected cell phenotopes: (i) transformed MSV/MLV producers; (ii) non-transformed MLV producers; (iii) transformed non-producers. We have also selected non-transformed revertants from one of the non-producer clones. This series of lines allows the study of the expression of the virus genome against a constant background of cellular gene expression. We have further characterized the lines with regard to anchorage dependence of growth, tumorigenicity and the presence of a rescuable sarcoma genome. The non-producer clones are uniform in their transformed properties. The revertants contain rescuable sarcoma virus, biologically indistinguishable from the original transforming virus, implying that the reversion is due to a change in cellular rather than viurs genetic information.

Animals↗
PubMed1979

Folic acid supplementation in low birth weight infants.

Low birth weight infants (246) entered a trial to folic acid supplementation from 3 weeks to 12 months of age. The folic acid group had significantly higher mean hemoglobin levels at 6 and 9 months of age but the differences were only about 0.5 gm/dl, there was no significant difference in hematocrit, and in both groups of infants the mean hemoglobin levels were higher than those of normal birth weight infants. The differences in hemoglobin, although statistically significant, are of uncertain clinical significance. Median red cell folate levels remained within the normal adult range in both groups of infants. A minority of infants in the untreated group had low red cell folate levels but this was usually temporary, corrected by dietary folate, and not associated with low hemoglobin. Weight gain was not affected by folic acid supplementation. The infants in this trial were fed with a milk preparation containing 3.5 microgram/100 ml of folic acid which is a similar concentration to that of human milk and we recommend that the folate content of milks fed to low birth weight infants should not fall below this level. We do not have sufficient grounds to recommend routine folic acid supplements for all low birth weight infants throughout the first year of life but there is a possibility that their folate intake may sometimes be suboptimal.

Anemia, Macrocytic↗
PubMed1978

Computed tomography, ultrasound, and cholestatic jaundice.

Computed tomography detected the presence of dilated ducts in 15 of 18 cases with extrahepatic obstructive jaundice and demonstrated the obstructing lesion in 18 out of 25. The cause of the obstruction was detected in the absence of duct dilatation, and calculi which were radiolucent on conventional radiographs were demonstrated. Ulstrasound detected dilated ducts in eight of 10 cases, but demonstrated the cause of the obstruction in only one of 13 cases. Both techniques are capable of demonstrating dilated ducts in the majority of cases, but computed tomography is better at detecting the cause of the obstruction.

Bile Duct Neoplasms↗
PubMed1977

Uses of barium meal examination in dyspeptic patients under 50.

No abnormality was found in 76 of 100 dyspeptic out-patients under the age of 50 who underwent barium meal examination, while various non-malignant lesions were found in the remaining 24. Only 10% of those under 30, and 10% of those with symptoms for less than a year proved to have any abnormality. Because of the radiographic results treatment was altered in only 11 patients, and most of these changes were small.

Adult↗
PubMed1976

Right atrial versus left atrial echo zones: a proposed new criterion for determining the atrial site of retrograde preexcitation.

In a patient whose electrocardiogram (ECG) initially (1966) showed a Type A Wolff-Parkinson-White pattern, recurrent supraventricular tachycardia (SVT) developed but never subsequently showed antegrade bypass conduction. Intracardiac pacing studies (1975) revealed that premature high right atrial (induced 250-450 msec after atrial depolarization) or coronary sinus depolarization (250-550 msec) resulted in SVT. Late coronary sinus depolarization resulted in SVT without A-H prolongation. During SVT, P wave morphology changed and the coronary sinus atrial electrogram preceded that from the low right atrium; retrograde ventriculoatrial conduction time was 240 msec. Neither pacing the high right atrium or coronary sinus up to rates of 200 beats/min nor progressive atrial premature depolarizations from the high right atrium or coronary sinus resulted in antegrade bypass conduction. Failure of antegrade bypass conduction does not preclude SVT due to retrograde preexcitation and must be distinguished from atrioventricular (A-V) nodal reentry. Atrial effective refractory period (200 msec) was shorter than the minimal time required for an atrial impulse to return to the atrium (380 msec), suggesting concealed antegrade bypass conduction. Stimulation of the atrium linked to the A-V bypass results in earlier bypass activation and recovery and explains the differing high right atrial vs coronary sinus echo zones.

Adult↗