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Biomedical subjects

R Harris

Publications and source records attributed to R Harris.

At least 523 records · Page 29Linked to original sources
PubMed1977

Suxamethonium pains and electromyograph recordings in children.

Surface electromyography was used to investigate muscle activity in children following the administration of suxamethonium. The duration, amplitude and frequency of muscle action potentials recorded in children were similar to those in adults. Twenty-three children had muscle action potential frequencies in excess of 50 Hz, but only two suffered pain after operation. The relationship between high frequency discharge rates of motor units noted in adults in earlier studies does not apply to children.

Action Potentials↗
PubMed1977

Clinical, biochemical, and physiological features distinguishing myoclonus responsive to 5-hydroxytryptophan, tryptophan with a monoamine oxidase inhibitor, and clonazepam.

Fifteen patients with a variety of myoclonic syndromes were studied clinically, pharmacologically, and physiologically. CSF tryptophan, 5HIAA, and HVA were also measured. Of these patients, 8 were improved to varying degrees by therapy with 5HTP, tryptophan in combination with MAOI (but not tryptophan alone), and clonazepam. This group included 6 cases of post-anoxic myoclonus, one case of post-traumatic myoclonus and one undiagnosed case of non-progressive focal myoclonus and epilepsy. In this group low levels of CSF 5HIAA were found compared to non-responsive cases and controls. Two cases of dysynergia cerebellaris myoclonica, 2 cases of undiagnosed aetiology, 2 cases of essential myoclonus, and one case of palatal myoclonus failed to respond to drug therapy. However, even amongst the responsive group the improvement varied. The most dramatic responses were seen in those patients in whom physiological study suggested that myoclonus was mediated by brain-stem structures. Less dramatic responses were seen in patients in whom the myoclonus appeared to originate from cortical structures. The neurochemical basis of myoclonus responding to 5HT precursors and clonazepam is discussed. It is suggested that such myoclonus arises from a relative hypoactivity of the 5HT neuronal system which results in a release of abnormal responses to sensory stimuli which characterize this type of myoclonus.

5-Hydroxytryptophan↗
PubMed1977

The radial dysplasia/imperforate anus/vertebral anomalies syndrome (the VATER association): Developmental aspects and eye findings.

The developmental evaluations of four children of different age groups with radial dysplasia/imperforate anus/vertebral anomalies syndrome are presented. These show that although the gross motor behavior is significantly delayed, intelligence, language, and social development are within normal range. Therefore, the patients with this syndrome merit every effort toward rehabilitation. Three of the patients discussed have ophthalmological abnormalities, in addition to their major malformations. It may be that congenital eye defects are another component of this syndrome of morphogenesis.

Abnormalities, Multiple↗
PubMed1977

The lowly mould.

Explore the source record for details and available documents.

Antibiosis↗
PubMed1977

Cardiopathy of aging: are the changes related to congestive heart failure?

Over the years, hemodynamic stresses and biologic changes bring about reduced cardiac function. The addition of one or more types of organic heart disease leds to further deterioration of fuction. This is why elderly patients require special consideration and management, why their clinical manifestations and therapeutic responses differ from those in young patients. Although no single abnormality characterizes the aging process, cellular, functional, and structural changes support the existence of a cardiopathy. However, there are insufficient data to link so-called senile cardiopathy directly to otherwise unexplained heart failure. Failure is usually due to the typical reasons, i.e., coronary artery or valvular disease, hypertension, amyloidosis, and chronic pulmonary lesions. Nevertheless, the possibility of senile heart failure should not be overlooked in case of impending or actual myocardial failure. In patients over 60, edema, dyspnea, or tachycardia cannot always be attributed to heart disease. It is hazardous to diagnose and prescribe treatment for cardiac failure if the heart shadow is not enlarged on the x-ray,the circulation time is not prolonged, and the heart sounds and rhythmare normal. Other reasons for the complaints should be looked for, even when the heart rate is fast.

Adult↗
PubMed1977

Comparison of different noninvasive methods of infarct sizing during experimental myocardial infarction.

This study evaluated the accuracy of several noninvasive infarct-sizing techniques in 12 awake, unsedated dogs with multivessel coronary obstructions and acute anterior myocardial infarcts. Estimations of infarct size by scintigraphy with technetium-99m Sn pyrophosphate (Tc-PP), serum creatine phosphokinase (CPK) release, peak serum myoglobin levels by radioimmunoassay, and precordial ECG mapping were compared and correlated with histologic measurements of infarct size. The comparisons indicate that precordial ST segments mapping, serum CPK release measurements and peak serum CPK, peak serum myoglobin, and Tc-PPi myocardial scintigraphy all provide approximate estimates of infarct size in this model. Each technique also has certain important limitations, however, including: (A) precordial mapping is relatively insensitive in the identification of small anterior infarcts, (B) serial serum CPK release measurements when obtained for only 24 hr after infarction tend to underestimate large anterior infarct size, and (C) Tc-PPi myocardial scintigrams may fail to recognize anterior infarcts less than 3 gm in size and may overestimate the size of small predominantly subendocardial infarcts. The findings also show that the closest estimate of histologic infarct size in this model was provided by combining two of the noninvasive techniques (precordial mapping to identify sites with 2 or more millimeters of ST segments elevation and Tc-PPi myocardial scintigrams) rather than by relying exclusively on any one technique alone.

Animals↗
PubMed1976

Hormonal control of fat cells adenylate cyclase.

Fat cells were preincubated for 2 h in the presence and absence of growth hormone (GH) and Dexamethasone (Dex) before the addition of increasing concentrations of either epinephrine, theophylline or glucagon and final incubation of the cells for an additional 5 minutes. GH and Dex increased by 85%, 28% and 72%, respectively, the cAMP levels reached in the sole presence of 10(-5)M epinephrine, 10(-2)M theophylline or 5 X 10(-5)M glucagon. An adenylate cyclase particulate preparation shows that epinephrine decreases Km from 2mM to 0.6 MM and increases Vmax and the strength of interaction value (n) from 0.91 to 1.75.

Adenosine Triphosphate↗
PubMed1976

Receptors for human immunoglobulin on acute myeloid leukaemic leucocytes.

Immunoglobulin (Fc) receptors were detected on leucocytes from patients with acute myeloid leukaemia (AML) by rosette formation with human cDE/cDE erthyrocytes (HE) sensitized with Rhesus (Rh) antisera (HEA). Of 7 Rh antisera tested, erythrocytes sensitized with anti-d (Gm10) detected the highest numbers of rosette-forming cells (HEA-RFC) in normal and AML leucocyte preparations. Using this assay, HEA-RFC was studied in 22 untreated AML patients and ce assay detected 11-6% lymphocyte and 2-1% granulocyte HEA-RFC in normal peripheral blood. Leucocytes from 16 to 22 AML patients had a similar or lower percentage than normal lymphocyte HEA-RFC, which could be explained by the dilution of peripheral blood leucocytes by poorly or non-rosetting leukaemic blasts. Ten of these 16 patients were diagnosed as having acute myeloblasts leukaemia. Six of the 22 AML patients had high HEA-RFC values of which 5 were diagnosed as having myelomonocytic leukaemia. Cytocentrifuge preparations of HEA-RFC showed that the proportion able to form rosettes was lower in myeloblasts than in monoblasts. Enzyme treatment (pronase), inhibition or simultaneous labelling of surface Ig and Fc receptors showed that the characteristic surface Ig found to AML cells is, at least in part, bound to Fc receptors. The HEA-RFC test described in this paper could be useful in the immuno-diagnosis of myelomonocytic leukaemia.

Adult↗
PubMed1976

Cell-mediated cytotoxicity as a result of immunotherapy in patients with acute myeloid leukaemia.

Leucocytes from normal individuals and from patients with acute myeloid leukaemia (AML) in remission receiving active immunotherapy with allogeneic AML blasts (AML-I) were cultured for 6 days with AML-I blasts, Burkitt's lymphoma cells (BL) or lymphoblastoid cells (LCL). The leucocytes were then tested for cell-mediated cytotoxicity (CMC) against 51Cr-labelled AML-I, BL or LCL target cells. There was no substantial difference in the CMC of leucocytes from patients and normals cultured without stimulation, and tested against AML-I, BL or LCL targets. Patient's leucocytes stimulated in vitro with AML-I had a greater frequency of positive CMC responses against AML-I, BL and LCL than normal individuals. The results suggest that co-cultivation of leucocytes with AML-I blasts reactivates memory cytotoxic leucocytes in AML patients receiving immunotherapy and that this test may be useful in measuring the effectiveness of immunotherapy.

Burkitt Lymphoma↗
PubMed1976

Response of remission lymphocytes to autochthonous leukaemic myeloblasts.

Thymidine incorporation in vitro by remission lymphocytes from a total of 6 patients with acute myeloid leukaemia (AML) was measured following stimulation by autochthonous and allogeneic AML blasts and cell lines. The early peak response to autochthonous blasts in 2 of these patients (48-72 h) is consistent with the concept of a population of lymphocytes pre-immunized to antigens carried by the blasts. Although stimulation in one patient was increased in the presence of more stimulating (S) blasts than responding (R) lymphocytes, positive responses in other tests were obtained at an S : R ratio of 1 : 1-5. When different methods of treatment of the stimulating autochthonous blasts were compared with untreated cells, mitomycin C gave the highest stimulation indices 2 out of 3 tests. Tissue culture medium in which autochthonous blasts had been incubated for 3-5 days failed to stimulate either remission lymphocytes alone, or combined cultures of lymphocytes with autochthonous or allogeneic blasts, suggesting that mitogenic factors released from autochthonous blasts are not responsible for lymphocyte stimulation. Treatment of autochthonous or allogeneic AML blasts with glycine-HC1(pH 3-0) to remove putative "blocking" factors failed to increase the stimulatory capacity of the leukaemic blasts.

Antigens↗
PubMed1976

Serological identification of Ia antigens: report of a British region Ia workshop.

In preparation for the 7th International Histocompatibility Workshop 13 laboratories in the British Region participated in a local workshop. One hundred and twenty-three sera which had been previously shown to have activity on either normal B cells, CLL cells or B cell lymphoid lines in the absence of HLA-A, B or C activity were exchanged between the laboratories. These sera were tested on a total of 212 B cells, 101 CLL cells, 76 T cells and 76 lymphoid cell lines. The data was collected and analyzed in Oxford. The analysis showed that six groups of sera could be distinguished. When these groups were compared with the D locus typing of some of the lymphoid lines which were derived from individuals used as MLC typing cells, they were seen to have significant associations with D locus antigens. The serological groups defined were therefore given numbers corresponding to the D locus numbers they associate with, i.e. UK1 is associated with DW1 and so on for UK2, 3, 4, 5 and 7. Comparison of typing techniques showed that long incubation both with antiserum and then with complement, 1 hour + 2 hours gave the best and most reproducible reactions on normal B cells. Residual anti-HLA-A, B or C activity in some of the sera even after platelet absorption showed the importance of adequate checking on T cells after absorption.

Antibody Specificity↗
PubMed1976

Confirmation of the existence of human serum leukaemia-associated antigens (LAA).

We have obtained antisera from rabbits which react with serum from several leukaemia patients after absorption with normal human serum. The specificities of these rabbit antisera have been shown to be closely related to those of the original anti-LAA antisera of Viza et al (1970) and Harris et al (1971). Thus, the existence of leukaemia associated (but probably not leukaemia specific) serum antigen in man has been confirmed. One of the animals was immunized with normal amniotic fluid obtained at 15-16 weeks of gestation. Thus, LAA seems to be a normal constituent of amniotic fluid. This suggests that LAA is another onco-fetal component.

Acute Disease↗