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R J Blunt

Publications and source records attributed to R J Blunt.

8 recordsLinked to original sources
PubMed1999

Accuracy of the tomey topographic modeling system in measuring surface elevations of asymmetric objects.

BACKGROUND: Most studies have assessed the accuracy of videokeratographic systems using spheres, ellipsoids, or toric surfaces. Most human corneas are asymmetric to some degree and many pathological corneas are markedly asymmetric. To date, little work has been done to ascertain the accuracy of videokeratographic systems for measuring the shape of asymmetric objects. PURPOSE: The purpose of this study is to determine the accuracy with which the Tomey Topographic Modeling System can evaluate the topography of asymmetric surfaces. METHODS: Calibrated ellipsoidal test objects were tilted with respect to the videokeratometric axis to create asymmetric test surfaces with known characteristics. RESULTS: Root mean squared error of all the measured surface elevations varied from 0.7 microm to 11.3 microm. Although there was a trend for greater error with the more asymmetric surfaces, the trend was not statistically significant. Accuracy was not dependent on apical radius. Measurement error increased toward the periphery. CONCLUSIONS: For the Tomey Topographic Modeling System, the accuracy in measurement of smooth, asymmetric surfaces is comparable the accuracy in measurement of symmetric surfaces.

Cornea↗
PubMed1981

Raynaud syndrome.

Explore the source record for details and available documents.

Adrenergic beta-Antagonists↗
PubMed1980

Hyperviscosity and thrombotic changes in idiopathic and secondary Raynaud's syndrome.

Whole-blood viscosity (measured at 128, 23 and 0.2 s-(1) was significantly increased in 29 females with Raynaud's syndrome, 13 males with vibration-induced Raynaud's syndrome, and 18 males with calf claudication secondary to atherosclerosis, as compared with 50 healthy controls matched for sex, age and smoking habit. Viscosity was higher at low temperature (27 and 22 degrees C) in all three types of vascular disease and, despite symptoms of cold hypersensitivity, patients with Raynaud's syndrome did not show selective hypersensitivity at low temperature. Patients with vascular disease, irrespective of aetiology, also showed an increase in the acute-phase reactants haptoglobin, fibrinogen, and factor VIII antigen, together with reduced fibrinolytic activity and minor activation of platelets. These alterations in viscosity and haemostatic factors in vascular disease are probably related to the degree, rather than the aetiology, of endothelial damage and their cumulative effect may contribute to local stasis and thrombosis, particularly in cold extremities.

Adult↗
PubMed1977

Sclerosing peritonitis due to practolol: a report on 9 cases and their surgical management.

Nine patients with an unusual and serious intraabdominal complication of the beta-adrenergic blocking agent practolol seen since 1973 are reported. The striking and bizarre peritoneal changes induced by the drug have distinctive features that are not shown by other forms of peritoneal disease. The cases presented with small bowel obstruction, usually chronic in type and often associated with profound weight loss and an abdominal mass. Characteristic radiological features were present. The abnormalities at laparotomy were impressive, with a gross proliferation of the visceral peritoneum which formed a dense white cocoon which encased, constricted and markedly shortened the small bowel, usually from the duodenojejunal flexure to the ileocaecal valve. The obstruction was relieved by mobilizing the small bowel from the ensheathing tissue. Restoration of alimentary function after surgery was delayed but the long term result was satisfactory with full relief of symptoms and the absence of recurrent obstruction during the follow-up period. This complication may arise after treatment with the drug has been stopped, and although long term oral therapy has been discontinued, further cases will almost certainly present for some time to come.

Aged↗
PubMed1975

The use of local anaesthetics to produce prolonged motor nerve block in the study of denervation hypersensitivity.

1. Silastoseal cuffs containing 25% and 45% lignocain, 25% marcain and 25% NaCl were placed onto the sciatic nerve. The effects of this on the sciatic nerve as well as the soleus and extensor digitorum longus (EDL) muscles was studied. 2. Cuffs containing local anaesthetics caused both early and late phases of paralysis, cuffs containing NaCl caused only the late phase of paralysis, showing that the late phase of paralysis was not due to the anaesthetic properties of the drugs. The paralysis produced by these procedures was irreversible. 3. Responses to indirect and direct stimulation of soleus and EDL muscles were compared to assess the degree of denervation. In case of cuffs containing 25% marcain and 45% lignocain more than half of the muscle fibres were denervated. 4. Acetylcholine sensitivity was assesses in all experiments. Soleus and EDL muscles from all animals that had cuffed nerves containing either local anaesthetics or 25% NaCl were hypersensitive to ACh. The degree of hypersensitivity could be correlated to the degree of "denervation" as assessed by comparing the directly and indirectly elicited twitch tensions. 5. It was found that the sciatic nerve undergoes degenerative changes when exposed to cuffs containing either local anaesthetics or 25% NaCl.

Acetylcholine↗
PubMed1975

Inhibition of cell division and the development of denervation hypersensitivity in skeletal muscle.

1. It was found that in 3 day denervated soleus and EDL muscles nuclear division takes place. This can be stopped by administration of either 5-fluoro-uracil or vincristine. 2. The increased sensitivity to acetylcholine following denervation developed at a time when rapid cell division takes place. Both 5-fluoro-uracil and vincristine prevent the development of denervation hypersensitivity both in soleus and EDL muscles. 3. Muscle injury causes some cell division locally, but some phagocytic cells that infiltrate the damaged muscle appear to be blood-borne as their appearance within the muscle is not entirely prevented by either 5-fluoro-uracil or vincristine. Correspondingly the development of increased sensitivity that follows muscle injury is only partly prevented by administration of cytotoxic drugs. 4. It is suggested that the presence of dividing cells is causally related to the development of denervation hypersensitivity.

Acetylcholine↗