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Biomedical subjects

M Ray

Publications and source records attributed to M Ray.

At least 73 records · Page 4Linked to original sources
PubMed1978

UDP-glucose 4-epimerase from Saccharomyces fragilis. Involvement of sulfhydryl group(s) at the active site.

UDPglucose-4-epimerase (EC 5.1.3.2) from Saccharomyces fragilis is inactivated by 0.1 mM 5,5'-dithiobis-(2-nitrobenzoate) in 6 min. Unlike p-chloromercuribenzoate-inactivated or heat-inactivated enzymes, the dithiobisnitrobenzoate-inactivated enzyme retains the dimeric structure and NAD is not dissociated from the protein moiety. Inactivation of the enzyme by dithiobisnitrobenzoate can not therefore be attributed to any subsequent loss of structural integrity or to the detachment of the cofactor from the apoenzyme. The inactivated enzyme can be almost fully reactivated in the presence of mercaptoethanol and characteristic properties of native enzyme are regained. The inactivation by dithiobisnitrobenzoate can be substantially protected by UDPglucose or UDPgalactose indicating a possible critical involvement of one or more sulfhydryl groups at the active site.

Binding Sites↗
PubMed1978

Analysis of DNA replication patterns of human fibroblast chromosomes: the replication map.

A replication map of human fibroblast chromosomes from two diploid human female fibroblast lines, 46,XX and 46,X, del (X)(q13), was determined using the 'fluorescent plus Giemsa' (FPG) technique. Each chromosome was found to stain homogeneously dark when thymidine was incorporated for the entire S phase of that particular cell. As the duration of exposure to thymidine progressively decreased by increasing the incubation time in bromodeoxyuridine, the staining intensity of chromosomes decreased and, concurrently, gaps in the staining began to appear. These gaps coincide with R bands and represent the earliest areas to complete DNA synthesis. As these areas widen and increase in frequency, first Q and G bands appear, and finally C bands. Homologous X chromosomes were easily differentiated by either a comparison of the bands present or their staining intensity. The replication kinetics of the structurally abnormal heterocyclic X chromosome were very similar to those of the normal heterocyclic X chromosome. The X chromosome with deletion of a portion of the long arm was consistently late in replication.

Cell Line↗
PubMed1978

Multiple primary malignancy in the elderly.

The longer a patient lives, the more predisposed he is to become host to primary malignant neoplasms at various sites. Hence the importance of follow-up clinics in long-term care facilities. Data on multiple malignancies at Oak Forest Hospital are presented. Among 34 such patients (average age, 72 years), 28 had malignant lesions at two primary sites, and 6 at three primary sites.

Age Factors↗
PubMed1978

Spontaneous and provoked coronary artery spasm: are they the same?

A 44-yr-old man suffering fro exertional, emotional and spontaneous angina underwent coronary arteriography. During the examination he had a spontaneous attack of angina with ST elevation in the anterior leads. Injection of a contrast medium in the left coronary artery during pain showed marked spasm with anterior descending artery occlusion. The spasm was quickly relieved by nitroglycerin. Intravenous administration of 0.4 mg of ergonovine maleate reproduced the anginal episode with pain, ST elevation in the anterior leads and coronarographic patterns of a spasm occluding the anterior descending artery at the same level. After nitroglycerin, the pain disappeared and the electrocardiographic and coronarographic findings returned to basal conditions.

Adult↗
PubMed1978

[Electrophysiological aspects of ectopic atrial tachycardia (author's transl)].

In 10 patients with supraventricular tachycardia who underwent an electrophysiological study the ectopic atrial origin of the tachycardia could be demonstrated by the intracavitary localization of the earliest depolarized point (six cases in the right atrium and four cases in the left). Vagal stimulation and/or the i.v. infection of ATP induced or increased the degree of AV block during tachycardia; in five cases ATP interrupted the tachycardia. On the basis of their clinical and electrophysiological behavior, the patients were divided into two groups. In the first one (6 patients) tachycardia was persistent, started following late atrial beats with the same morphology of the subsequent and showed a progressive initial rate increase (warm-up phenomenon); programmed atrial stimulation failed to start and interrupt it. In the second group (4 patients) tachycardia was paroxysmal or repetitive, started following early atrial beats and could be induced and interrupted by programmed atrial stimulation. With respect to the electrophysiological characteristics of each group the authors try to define the possible mechanism responsible for the tachycardia (automaticity and micro-reentry).

Adenosine Triphosphate↗
PubMed1977

Favorable effects of hyaluronidase on electrocardiographic evidence of necrosis in patients with acute myocardial infarction.

To evaluate hyaluronidase's effect in reducing post-infarction myocardial necrosis, we randomized 91 patients with anterior infarction to control (45) or to hyaluronidase-treatment (46) groups. A 35-lead precordial electrocardiogram was recorded on admission and seven days later. Hyaluronidase was administered intravenously after the first electrocardiogram and every six hours for 48 hours. QRS-complex changes were analyzed to assess the drug's effect. Precordial sites with ST-segment elevation (larger than or equal to 0.15 mV) on the initial electrocardiogram that retained an R wave were considered vulnerable for the development of electrocardiographic signs of necrosis. The sum of R-wave voltages of vulnerable sites fell more in the control group than in the hyaluronidase group (70.9 +/- 3.6 per cent [+/- 1 S.E.M.] vs 54.2 +/- 5.0 per cent P less than 0.01). Q waves appeared in 59.3 +/- 4.9 per cent of the vulnerable sites in control versus 46.4 +/- 4.9 per cent in hyaluronidase-treated patients (P less than 0.05). Thus, hyaluronidase reduced the frequency of electrocardiographic signs of myocardial necrosis.

Acute Disease↗
PubMed1977

Phenotypic correlations in patients with ring chromosome 22.

This paper reports two patients with a ring 22 chromosome which has been confirmed by Q-banding. The literature contains 19 patients with a ring G-group chromosome which has been shown by chromosome banding to be a ring 22. The most commonly reported features in affected patients have included: retardation with disproportionate verbal delay, reduced head circumference, hypotonia, unsteady gait, large ears with abnormal configuration, and epicanthic folds. The importance of these, as well as other, less often noted findings, is discussed in relation to a possible r(22) syndrome.

Abnormalities, Multiple↗
PubMed1977

Cebocephaly in an infant with trisomy 18.

An infant who died in the perinatal period with the unusual association of trisomy 18 and cebocephaly is described. It is suggested that this association may be more common than is generally recognised because the majority of such infants are stillborn or live only briefly and often do not have chromosome studies performed.

Brain↗