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Biomedical subjects

D A Levison

Publications and source records attributed to D A Levison.

At least 109 records · Page 6Linked to original sources
PubMed1984

Unexpected inorganic elements in oral lesions: results of X-ray energy spectroscopy (XES) on particulate matter in paraffin sections.

X-ray energy spectroscopy (XES) of all particulate matter found by light microscopy in histological sections of 222 oral lesions revealed a much wider range of elements than expected from dental amalgam. Subsequent XES of a variety of endodontic materials, impression materials and toothpastes indicated possible sources for virtually all elements identified in the histopathological lesions. The range of materials identified is tabulated; histopathological lesions and probable source substances are correlated; light microscopic pointers to the elemental nature of particulate matter in sections are indicated--titanium and bismuth have characteristic appearances; possible implications of local implantation and large scale ingestion of such substances are discussed.

Barium Sulfate↗
PubMed1984

The pharmacokinetics of subcutaneous bolus cytosine arabinoside in an arachis oil plus aluminium distearate suspension.

An attempt was made to create a delayed release preparation of cytosine arabinoside (araC) which could be administered subcutaneously, and would produce plasma levels similar to steady state infusion concentrations. A thixotropic suspension of araC in arachis oil and aluminium distearate was formulated. This preparation was similar to that previously used with bleomycin oil suspension and procaine penicillin. Two hundred mg/ml of araC in arachis oil containing varying amounts of aluminium distearate were administered firstly to New Zealand White rabbits and then to patients with acute myelogenous leukaemia. This preparation was well tolerated by both rabbits and patients but did not delay the release of araC from the subcutaneous tissues.

Animals↗
PubMed1984

Varied light and scanning electron microscopic appearances of barium sulphate in smears and histological sections.

The various light and scanning electron microscopic appearances of barium sulphate in smears and in histopathological lesions in sections are illustrated. One type of barium sulphate (E-Z-HD) includes much larger, bright birefringent particles and has very different appearances from other widely used types. Such larger particles in sections were not originally suspected to be barium sulphate and were identified only by energy dispersive x ray analysis in a scanning electron microscope. This form of barium sulphate is used for double contrast upper gastrointestinal radiography, and is not thought to have been responsible for the lesions in which it has been observed by us.

Barium Sulfate↗
PubMed1983

Merkel cell tumour: report of a case.

We report the case of a 75-year-old lady with recurrent primary cutaneous Merkel cell tumours. The condition can be misdiagnosed as lymphoma or anaplastic carcinoma, and the definitive diagnosis can be made only by electron microscopy of fresh tissue. This is the first reported case in the British literature.

Aged↗
PubMed1982

Microscopic colitis-a cause of chronic watery diarrhoea.

Six patients with severe watery diarrhoea were found to have microscopic total colitis. None had any abnormality detectable by conventional tests used to diagnose inflammatory bowel disease-namely, barium radiology and endoscopy. The diagnosis could only be made by microscopic examination of biopsy specimens from the apparently normal colon. Anaemia, raised erythrocyte sedimentation rate, hypokalaemia, and hypoalbuminaemia were common findings. Small-bowel function was normal in all, though three patients had jejunal lesions of uncertain relevance but seemingly unrelated to the diarrhoea. The five patients given anti-inflammatory drugs showed a satisfactory response with improvement of the diarrhoea and colonic inflammation and return to normal of the abnormal laboratory findings. Microscopic colitis is responsible for a proportion of cases of intractable diarrhoea of obscure origin and rectal and colonic biopsies sould be undertaken in such cases.

Adult↗
PubMed1982

Slow cirrhosis--or no cirrhosis? a lesion causing benign intrahepatic portal hypertension.

We report the histological findings in livers from a group of 60 patients with benign intrahepatic portal hypertension. The lesion is benign in comparison with true cirrhosis in the sense that most of the patients survive many years from the time of diagnosis. The histological changes, in our view, differ from those of any variant of cirrhosis and generally do not progress even after many years. The essential features are: (1) irregular capsular thickening; (2) thickening of some portal tracts with fine fibrous septa radiating out from some of them; and (3) distortion of lobular architecture with hyperplastic expansion of some areas and compression of others and irregularly distributed central veins. We suggest that this is the lesion responsible for at least some cases of so-called idiopathic non-cirrhotic portal hypertension.

Follow-Up Studies↗
PubMed1982

Combined light and electron microscope in routine histopathology.

We report our experience with a prototype combined light and electron microscope (the LEM 2000) with particular reference to its application to routine surgical histopathology. We found its major advantages over conventional transmission electron microscopies were due to the large grid size (7 mm diameter), low magnification capacity (x 250), and the built-in microprocessor for recording areas of interest. These features combine to reduce sampling errors and greatly facilitate orientation and relocation of fields of diagnostic importance.

Histological Techniques↗
PubMed1981

Interaction of azaserine and raw soya flour on the rat pancreas.

Rats have been fed for up to 2 years with either raw soya flour or control diets of heated soya flour or rat chow not containing soya flour. In addition, the rats received weekly injections of either a weak pancreatic carcinogen (azaserine) or control injection of saline. We found that rats fed a diet of raw soya flour and given weekly injections of azaserine developed benign and malignant neoplasms of the pancreas earlier in life and much more frequently than rats given raw soya flour alone, whereas azaserine alone in the dose used in this study did not produce pancreatic cancer. We conclude that raw soya flour sensitizes the pancreas to the action of azaserine.

Animals↗
PubMed1981

Diffuse interstitial renal tuberculosis--an unusual cause of renal failure.

Three immigrant patients are described with diffuse interstitial renal tuberculosis. Two had associated pulmonary tuberculosis and the third had tuberculous peritonitis. Excretion urography gave no clue to the diagnosis. At the time of diagnosis by renal biopsy two patients had severe chronic renal failure. In one, renal impairment had progressed during the course of anti-tuberculous treatment. The third patient showed marked fluctuations in renal function, and improvement appeared to relate to concomitant corticosteroid therapy. The importance of this particular form of renal tuberculosis has not previously been emphasized.

Adult↗
PubMed1981

Non-cirrhotic intrahepatic portal hypertension: A long term follow-up study.

The clinico-pathological features and prognosis of 59 cases of non-cirrhotic portal hypertension seen at one hospital over a 30-year period are described. Diagnosis was made on operative wedge liver biopsy in most cases. All but two had clinical features of portal hypertension and 47 had bled from oesophageal varices. In 53, portal decompression was performed without operative death or variceal rebleeding. Subsequent liver histology in 16 cases up to 18 years after diagnosis showed no change in the majority. The relatively static morphology was reflected in the clinical course. Twenty-two patients have died but only 11 as a result of liver disease or its treatment. Actuarial analysis shows the five year survival to be 90 per cent and the 30-year survival 55 per cent in strong contrast to the grim prognosis for cirrhosis. The infrequency of operative liver biopsies and unfamiliarity with the disease lead to underdiagnosis.

Adolescent↗
PubMed1980

A practical method for the identification of particulate and crystalline material in paraffin--embedded tissue specimens.

The combination of light microscopy, low temperature micro-incineration of paraffin sections, and subsequent scanning electron microscopy (SEM), with X-ray energy spectroscopy (XES) has been shown to allow rapid and reliable identification of inorganic crystalline and particulate material in body tissues. Applications of this technique to hospital practice are illustrated and its potential in diagnosis and research are suggested.

Electron Probe Microanalysis↗
PubMed1980

The effects of long-term feeding of soya flour on the rat pancreas.

Rats were fed raw and heated soya flour for up to 2 years. The rats fed raw soya flour all developed pancreatic hypertrophy and hyperplastic and adenomatous nodules. Four of 26 rats fed raw soya flour continuously and 1 of 5 rats fed raw soya flour for 2 days each week developed pancreatic cancer. Preheating the soya flour seemed to protect against the pancreatic hyperplastic and neoplastic changes.

Adenoma↗