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Biomedical subjects

J M Robinson

Publications and source records attributed to J M Robinson.

197 records · Page 11Linked to original sources
PubMed1975

Frontal sinus cancer manifested as a frontal mucocele.

During the period 1972 to 1974, 12 frontal mucopyoceles were seen. Subsequently, three were shown to have an underlying neoplasm. Evaluation of the roentgenograms demonstrated minor differences between those with and those without a malignant basis. In previous reports of frontal sinus cancer, the descriptions of the roentgenograms suggest that it is possible that these features were also present. The difficulty in deciding the sinus of origin in such cancers has often been discussed, but the possibility that neoplasms of the orbital lobe of the lacrimal gland may occur in the frontal sinus is usually not considered. Anatomically, the intimate proximity of this lobe to the frontal sinus suggests that a neoplasm could develop in this manner. I believe that this was true in two of the patients reported herein.

Adenocarcinoma↗
PubMed1975

Ergot alkaloids. Synthesis of 6-methyl-8-ergolenes as inhibitors of prolactin release.

A general synthetic route from elymoclavine (4a) to a variety of C-17 substituted 8-ergolenes has been established. [The C-17 position is the carbon attached to C-8 of the ergoline (1) skeleton as indicated in structure 2.] This route involves displacement reactions on the allylic chloride (4h) prepared from 4a by reaction with thionyl chloride. Conversion of the naturally occurring tricyclic clavines, chanoclavine I (5a) and isochanoclavine I (5b), to the tetracyclic clavine, agroclavine (4i), has been achieved. The new compounds prepared were tested for prolactin-inhibiting ability and were found to possess activity. One of the compounds prepared, 6-methyl-8-ergolenylacetamide (4k), was very potent, comparing favorably in activity to the best prolactin inhibitors reported to date.

Animals↗
PubMed1975

Effect of Disalicylidenepropanediamine on the Light-dependent Reduction of Carbon Dioxide and Glycerate 3-Phosphate in Intact Spinach Chloroplasts.

Disalicylidenepropanediamine (DSPD) at 0.1 to 1 mm levels inhibited light-dependent (14)CO(2) assimilation in intact spinach chloroplasts about 50 to 80%, and this inhibition was accompanied by an increased ratio of (14)C-glycerate 3-phosphate to (14)C-glyceraldehyde 3-phosphate. Enzymatic analysis established that DSPD also inhibited the light-dependent reduction of glycerate 3-phosphate in intact spinach chloroplasts. DSPD at 0.5 mm did not inhibit ribose 5-phosphate isomerase, ribulose 5-phosphate kinase, glycerate 3-phosphate kinase, NADP(+)-linked glyceraldehyde 3-phosphate dehydrogenase or ribulose 1,5-diphosphate carboxylase. The inhibition of chloroplast (14)CO(2) assimilation by DSPD appeared to be related to the inhibition of the photosynthetic electron transport chain. These observations are consistent with experimental results which demonstrated that DSPD inhibited directly the chloroplast lamellar membrane-mediated, light-dependent reduction of ferredoxin (Trebst, A. and M. Burba, 1967, Z. Pflanzenphysiol. 57: 419-433 and Ben-Amotz, A. and M. Avron, 1972, Plant Physiol. 49: 244-248).

Journal Article↗
PubMed1975

Factors affecting the release of haemoglobin and enzymes from human erythrocytes.

The efflux of lactate dehydrogenase and haemoglobin from human erythrocytes during prolonged incubation at 37 degrees was significantly reduced by ATP, ADP, AMP, UTP, creatine phosphate, or phosphoenolpyruvate and to a lesser extent by fructose, glucose 6-phosphate or fructose 6-phosphate, but not by glucose. Iodoacetate, however, markedly increased the loss of haemoglobin and slightly increased that of lactate dehydrogenase. Phospholipase C greatly accelerated the relase of haemoglobin, lactate dehydrogenase, pyruvate kinase, hexokinase, glucose 6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase from human erythrocytes, but this effect was also reduced in the presence of ATP or ADP. The loss of lactate dehydrogenase, malate dehydrogenase, and pyruvate kinase from the cells treated with phospholipase C increased as their ATP content fell. In a series of experiments in which the action of phospholipase C was stopped by the subsequent addition of trypsin, ATP and ADP (1 mmol/l) significantly reduced the efflux of haemoglobin, but AMP had no such effect. The results are consistent with the conclusion from our previous work that enzyme leakage is related to diminution in the energy content of the cells. The protective action of AMP on cells not treated with phospholipase C, however, differs from earlier findings with rat lymphocytes and it is suggested that in red cells it might be converted into ATP or that it has a direct effect on the permeability of the cell membrane.

Adenosine Diphosphate↗
PubMed1974

Photosynthetic intermediates, the warburg effect, and glycolate synthesis in isolated spinach chloroplasts.

Increasing levels of CO(2) have been shown to stimulate the rate of photosynthesis, eliminate the oxygen inhibition of photosynthesis (Warburg effect), and decrease glycolate formation in isolated spinach chloroplasts. Ribose 5-phosphate and fructose 1,6-diphosphate at concentrations of 5 to 10 mum also stimulate the rate of plastid photosynthesis and eliminate the Warburg effect. In contrast to the effect of high CO(2) levels, these sugar phosphates have little effect on glycolate formation. Evidence is presented to show that the level of intermediates of the photosynthetic carbon reduction cycle may influence the Warburg effect in vivo. It is postulated that the formation of glycolate is not the causal factor of the Warburg effect.

Journal Article↗
PubMed1968

Oxygen evolution and the permeability of the outer envelope of isolated whole chloroplasts.

A rapid oxygraph method of studying the permeability of the envelope of isolated chloroplasts was used. The outer envelope of aqueously isolated whole spinach (Spinacia oleracea L.) chloroplasts in buffer is readily permeable to 3-phosphoglyceric acid, which induces an immediate light dependent oxygen evolution. This light dependent oxygen evolution was completely eliminated by swelling these plastids in an osmotically dilute solution. Exogenous adenosine diphosphate, but not inorganic phosphate, strongly stimulated this oxygen evolution. This indicated that the chloroplast envelope is relatively permeable to adenosine diphosphate.Oxygen evolution and swelling studies indicated that the chloroplast envelope is relatively impermeable to NADP and to ferredoxin.A method is described whereby the percent of whole chloroplasts present in a chloroplast preparation may be rapidly estimated.

Journal Article↗
PubMedDate not supplied

Glyceryl trinitrate as a hypotensive agent in middle-ear surgery.

A total of 47 patients having microsurgery of the middle-ear under general anaesthesia received an infusion of glyceryl trinitrate to produce controlled hypotension. The operating field was evaluated by the surgeon by means of a simple scoring system. Using this technique satisfactory conditions were achieved in all patients without complications.

Adolescent↗
PubMedDate not supplied

Longitudinal nursing case management for elderly heart failure patients: notes from the field.

Longitudinal case management is an intervention delivered by professional nurses that involves following patients from the inpatient to the outpatient arena. The hands-on process of day-to-day case management of elderly persons with heart failure is presented. The issues associated with delivering this intervention to this patient population are examined, and implications for refining the case management process are discussed.

Aged↗