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Biomedical subjects

J D Lewis

Publications and source records attributed to J D Lewis.

At least 91 records · Page 5Linked to original sources
PubMed1990

Cutaneous blood flow responses in the forearms of Raynaud's patients induced by local cooling and intradermal injections of CGRP and histamine.

1. The cutaneous responses of the forearm to local cold exposure and intradermal injection of CGRP and other vasoactive mediators were compared in primary Raynaud's sufferers and normal volunteers. 2. Skin responses in the forearm were measured in terms of erythema reddening and skin blood flow. Visual responses were recorded by tracing and then area calculated by computerised planimetry. Skin blood flow was measured using a laser Doppler blood flow meter. 3. Cooling (5-6 degrees C for 2 min) of a 1 cm2 area of the forearm caused a localised reactive hyperaemia response in normal volunteers, measured using the last Doppler blood flow meter. The peak response in Raynaud's patients was significantly smaller than that of normal volunteers. 4. The cutaneous responses of Raynaud's patients and normal volunteers to intradermal injections of CGRP, histamine and PGE2 were not significantly different. 5. The results suggest that Raynaud's sufferers do not exhibit a diminished response to CGRP in the cutaneous microvasculature and can respond normally to histamine with an axon reflex mediated flare.

Adult↗
PubMed1990

Peripheral laser assisted angioplasty: results, complications and follow-up.

Detailed results including complications and ultimate outcome of 24 laser assisted angioplasties in 22 patients are presented. Despite the enthusiasm expressed in other published reports, we remain sceptical of the value of laser using a 1.5 mm 'hot-tip' probe for assisting angioplasty of peripheral occlusions. The tendency for this type of probe to damage the vessel wall and in so doing prohibit the use of subsequent balloon dilatation is a major problem. In this small series the long-term patency was not improved compared with conventional angioplasty. We have established the relative safety of this laser technique and further advances in probe design may lead to greater success in crossing long lesions. Long-term maintenance of patency in these diseased arteries will need further advances in technique and assessment preferably by a controlled trial.

Aged↗
PubMed1989

Identification of a mammalian protein that binds specifically to DNA containing methylated CpGs.

The effects of DNA methylation on transcription and chromatin structure require that nuclear factors be able to distinguish methylated and nonmethylated DNA. We describe a methyl-CpG binding protein (MeCP) that complexes with a variety of unrelated DNA sequences when they are methylated at CpG. Fifteen or more symmetrically methylated CpG moieties per molecule are required for strong binding under our conditions. Competition experiments show that vertebrate DNAs bind to MeCP, whereas naturally nonmethylated genomes or cloned vertebrate genomes do not bind. Cross-linking experiments detect a 120 kd protein that correlates stringently with MeCP activity. Species and tissue comparisons show that MeCP is widely distributed in mammals except in embryonal carcinoma cell lines, which have very low levels.

5-Methylcytosine↗
PubMed1988

Occult carcinoma of the breast masquerading as primary adenocarcinoma of the small intestine. A case report.

A fifty-year-old woman with abdominal pain, diarrhea, and weight loss ultimately required exploratory laparotomy. The entire small intestine was extensively infiltrated by poorly differentiated adenocarcinoma; mesenteric lymph nodes and surrounding omentum were involved, but no extragastrointestinal tumor was found. A presumptive diagnosis of unresectable primary carcinoma of the small bowel was made. Chemotherapy was initiated with 5-fluorouracil 300 mg/m2/day by continuous intravenous infusion. Nine months later a left breast mass with multiple ipsilateral axillary and supraclavicular lymph nodes developed; biopsy revealed a poorly differentiated adenocarcinoma morphologically identical to the tumor involving her small bowel. In spite of breast irradiation and systemic hormonal therapy, the patient deteriorated rapidly and died from progressive metastatic disease.

Breast Neoplasms↗
PubMed1988

Three somatic responses in grief.

The special instance in which the manifestations of grief are expressed principally in the somatic realm is discussed. Three case histories are presented to illustrate varieties of physical response to bereavement and to illustrate the various mechanisms responsible for the transformation of grief into physical symptomatology and illness.

Adaptation, Psychological↗
PubMed1988

Bacterial colonisation of leg ulcers and its effect on the success rate of skin grafting.

There is little information on the immediate and long-term results of skin grafting to chronic lower limb ulcers. Our experience in their management had led us to analyse, retrospectively, the results of split thickness skin grafts applied to lower limb ulcers in 88 consecutive patients. Graft take has been related to bacterial growth from ulcer swabs taken on admission, preoperatively and postoperatively. Follow-up was for a median of 18 months. Initial graft take varied from 20% to 100% (median 85%). Bacterial flora grown from the ulcer swabs varied with the duration of the ulcer and the treatment. Analysis by bacterial type has shown that Staphylococcus aurcus and Pseudomonas significantly reduced skin graft healing. Overall, 90% of these ulcers had healed with a median of 6 weeks' in-patient treatment. Examination of the swab results from the 8 ulcers that were slow to heal postoperatively and the 8 ulcers that recurred 6 days to 8 months after discharge from hospital revealed that 15 out of 16 (94%) grew S. aurcus; none had Pseudomonas isolated from them. After eighteen months 8% of these ulcers remain active. Aetiology appears important as this figure is 6% for limbs affected by venous disease only, 13.3% for limbs with arterial disease only and 13.6% for limbs with both venous and arterial disease.

Aged↗
PubMed1987

Graduated compression and its relation to venous refilling time.

Graduated compression is important in improving venous function, but the pressure profiles of different brands of stockings in situ and effects on a direct measure of venous function have not been investigated. The pressure profiles of 15 different types of below knee compression stockings were established with a medical stocking tester in 13 healthy volunteers. Analysis of variance was performed for each stocking separately, considering the factors of size of stocking, site of measurement, and their interaction. The criteria used to define satisfactory function were that the stockings should have a significant linear trend with site--that is, graduation--and no other significant effects. Only five types of stockings met these standards. Venous function was then assessed by photoplethysmography in 19 patients with defined venous abnormalities. For each patient the effect on venous refilling time of three satisfactory and three unsatisfactory stockings was assessed. The three satisfactory stockings gave refilling times that were not significantly different from normal in patients with both superficial and deep vein incompetence, while refilling times with the three unsatisfactory stockings remained significantly below normal in all patients with deep vein incompetence; one stocking had no significant effect on refilling times in either group. Functional testing of compression hosiery should form part of future British Standards specifications.

Biometry↗
PubMed1987

The management of the limb in acute venous thrombosis.

This review addresses the management of the limb in patients with deep vein thrombosis. The concepts that underline such treatment are reviewed and the importance of objective diagnosis before the institution of long term therapy is stressed. Management is considered in relation to the extent of segmental venous involvement and to the use of Heparin, Streptokinase, Warfarin and surgical therapy. There is a lack of adequate and comprehensive follow up data on the limb in patients with deep vein thrombosis and in particular there are few objective studies relating to the short and long term sequelae as far as valvular function is concerned. There is uncertainty concerning the appropriateness of continuing compression therapy and the value of such therapy in reducing long term morbidity. The importance of recognising the potentially severe ischaemic consequences of massive venous thrombosis are described, together with an outline management plan. The importance of short and long term follow up studies of the limb is stressed particularly in relation to potential changes in methods of treatment.

Humans↗
PubMed1986

Leg ulcers: epidemiology and aetiology.

In a regional Health District with a population of 198,900, 357 patients with 424 ulcerated legs were documented, an overall prevalence of 0.18 per cent. The prevalence of ulceration in the 92,100 aged greater than 40 years was 0.38 per cent. Fifty per cent of the lesions had been present for more than one year, and 62 per cent of patients had never attended any hospital. The patients were stratified by history of peripheral arterial disease. A random sample (100 patients, 193 legs) was examined by ultrasound and photoplethysmography to assess the venous and arterial circulation; 38 per cent had evidence of deep vein involvement and 43 per cent had superficial vein incompetence. An ischaemic element was present either in isolation (9 per cent) or combined with venous disease (22 per cent) in a total of 31 per cent, with a mean pressure index of 0.62 (s.d. 0.14). Simple objective methods of assessment together with dedicated community staff with ready access to specialized facilities can enhance the service provided to patients with leg ulcers.

Adult↗
PubMed1986

Facilitation of nasogastric and nasotracheal intubation with a nasopharyngeal airway.

The two new uses for the nasopharyngeal airway include facilitation of nasogastric intubation and nasotracheal intubation. First this technique takes advantage of the nasopharyngeal airway's unique ability to traverse the nasopharynx atraumatically and serve as a conduit for the smaller nasogastric tube. This technique also utilizes the nasopharyngeal airway to dilate the nasopharyngeal passage atraumatically, thus facilitating the passage of an endotracheal tube during nasotracheal intubation.

Humans↗
PubMed1986

Peripheral vascular disease: prospective study of intraarterial digital subtraction angiography using a 9-inch intensifier.

A prospective randomized study was undertaken to evaluate the role of intraarterial digital subtraction angiography (IADSA) in the study of peripheral vascular disease. Patients underwent either conventional film-based angiography alone, digital subtraction angiography (DSA) alone, or a combined study. With a 9-inch image intensifier, DSA alone resulted in cost savings of film and contrast material but required a significantly longer examination period than the other groups and an increased iodine dose per examination. When the images were analyzed by a radiologist and a vascular surgeon, the DSA studies provided less detail in the aortoiliac region than the other techniques but had advantages in demonstrating the runoff vessels. IADSA examination should not replace conventional arteriography in patients with peripheral vascular disease but has a useful complementary role.

Aged↗
PubMed1984

Mortality and rebleeding after hypertensive variceal disconnections.

Forty-five patients had operative disconnections of portoazygos venous collaterals for variceal hemorrhage. Nineteen alcoholic patients had urgent partial azygos disconnection (PAD) to control bleeding; this involved intragastric variceal and coronary and distal gastric-vein ligation. A complete azygos disconnection (CAD), which also included splenectomy, was done urgently in 14 patients and electively in 12 patients; 15 were alcoholics. All patients were assessed for operative risk by a modified Child's classification. Hospital mortality after urgent PAD or CAD in alcoholics was 67%, largely due to intraperitoneal sepsis or hepatorenal failure with recurrent hemorrhage. Operative modified Child's classification of survivors was better (lower) than in nonsurvivors. Eleven nonalcoholic patients had CAD; two died of intraperitoneal sepsis. Nine survivors did not rebleed nor have encephalopathy develop during an average follow-up of 41 months. Complete azygos disconnection was a good alternative, particularly in the elective setting, for patients with nonalcoholic portal hypertension.

Adolescent↗
PubMed1983

Studies on the haemopoietic toxicity of nitrous oxide in man.

Nitrous oxide inactivates vitamin B12 and in man can produce a megaloblastic anaemia. Haematological and biochemical changes were studied in nine surgical patients ventilated with 70% N2O for up to 24 h and in three control patients. There was a rise in the numbers of hypersegmented neutrophils in peripheral blood following N2O. Serial bone marrow aspirates showed gross megaloblastic change after 24 h of N2O which had reverted to normoblastic but dyserythropoietic haemopoiesis by 1 week. Giant forms of early myeloid precursors were also seen after 24 h ventilation with N2O but by 1 week abnormalities were evident in more mature cells, metamyelocytes and segmented neutrophils. Megaloblastosis was associated with abnormal dU suppression which showed a correction pattern similar to that seen in vitamin B12 deficiency. Administration of N2O was also associated with a progressive rise in serum folate and fall in serum methionine levels. No similar patterns were seen in the three control patients.

Anesthesia, General↗
PubMed1981

Long-term toluene abuse.

The authors briefly review the literature on the use of toluene as an intoxicating agent. They describe two cases in which the habit of sniffing toluene vapors extended over many years, discuss the rarity of this condition, and speculate about the conditions that might account for both the rarity and the occurrence of long-term toluene abuse.

Adolescent↗