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Biomedical subjects

D A Levison

Publications and source records attributed to D A Levison.

At least 91 records · Page 5Linked to original sources

Pulmonary alveolar microlithiasis. A new analytical approach.

A case of pulmonary alveolar microlithiasis is presented which has been investigated using X-ray energy spectroscopy and microscopic infrared spectroscopy. These methods gave precise details of the chemical composition of the microliths seen in this unusual disease. The pathogenesis of this disorder is discussed in the light of these findings.

Adult↗

Urothelial reaction to ureteric intubation. A clinical study.

Urothelial biopsies from ureters intubated with silicone (11) and other polymer (13) double J stents revealed features of mucous metaplasia in 12/24 cases. These changes were associated with encrustation of the stents and occurred principally in stone-forming patients.

Epithelium↗

Immunohistochemistry in district general hospitals in England and Wales.

The findings of a survey on the use of immunohistochemistry in district general hospitals in England and Wales are reported. Immunohistochemistry is used in most district hospitals, contributes to the accuracy and objectivity of some histopathological diagnoses, and is considered to be generally useful though not without drawbacks. Its expansion is being hindered by lack of funds for reagents and staff. In a few regions attempts are being made to rationalise expenditure and coordinate development of the service. We believe that if this can be done at a regional or national level then the relatively small cost entailed will be justified by a resulting improvement in the quality of patient care.

England↗

Granular cells as a marker of early amiodarone hepatotoxicity: a pathological and analytical study.

Two contrasting cases of amiodarone hepatotoxicity are described. In one, perivenular collections of swollen cells, probably macrophages, with granular cytoplasm in an otherwise nearly normal liver were observed. Transmission electron microscopy showed that the cytoplasmic granularity was due to lysosomal bodies of various sizes. X-ray energy and wavelength spectroscopic analysis showed a high iodine content in these lysosomal bodies, good presumptive evidence of the presence of amiodarone or one of its metabolites. In the second case there was a micronodular cirrhosis, and similar granular cells also containing iodine were seen in the fibrous connective tissue. These cases seem to represent the very early and late stages of amiodarone hepatotoxicity. In a patient taking this drug aggregates of swollen granular cells may be a sensitive and histopathologically useful marker of early amiodarone toxicity.

Amiodarone↗

Uptake of iodine-123 MIBG by pheochromocytomas, paragangliomas, and neuroblastomas: a histopathological comparison.

The percentage uptake of [123I]metaiodobenzylguanidine (MIBG) by tumors of the paraganglion system is compared with the number of neurosecretory granules (assessed by both light and electron microscopy) in the subsequently resected tumors in six patients. Iodine-123 MIBG was injected intravenously; the tumor uptake of [123I]MIBG varied between 0.001% and 0.14% of the injected dose per gram of tumor tissue at 22 hr. The number of neurosecretory granules in tissue sections was scored on a scale of I-III. A direct proportional correlation was found between the percentage uptake of [123I]MIBG by the tumor and the number of neurosecretory granules in the tissue sections but not with plasma or urinary catecholamines. This technique for imaging reflects the storage status of the tumor better than plasma and urinary catecholamine measurements.

3-Iodobenzylguanidine↗

Imaging of carcinoid tumors with iodine-123 metaiodobenzylguanidine.

Scintigraphy with 123I-radiolabeled metaiodobenzylguanidine (MIBG) was performed successfully in two patients with metastatic carcinoid tumor. The scintigraphic findings show diversity of the tumor deposits in the uptake of [123I]MIBG in the same patient and between patients.

3-Iodobenzylguanidine↗

Visceral and skin granuloma annulare, diabetes, and polyendocrine disease.

A middle aged man suffered with insulin dependent diabetes, autoimmune Addison's disease, myxoedema, and severe ulcerative colitis, for which he had undergone subtotal colectomy with formation of an ileostomy. Granuloma annulare confined to the anterior abdominal wall was diagnosed in 1981. In 1983 an episode of severe colicky pain and excessive working of the ileostomy occurred associated with severe hyperglycaemia and increased irritation of the granuloma annulare. Laparotomy disclosed adhesions and numerous white nodules over bowel, mesentery, and peritoneum histologically identical with the skin lesions. Two further episodes of subacute small bowel obstruction occurred, and a repeat laparotomy showed widespread intra-abdominal granuloma annulare. Visceral granuloma annulare appears not to have been reported before, and in this patient exacerbation of the skin lesion was associated with poor diabetic control.

Diabetes Complications↗

Spiral organisms in the human jejunum.

Spiral organisms were found in close apposition to the jejunal mucosa in a patient with idiopathic intestinal pseudoobstruction. Such organisms are generally not found in the jejunum and their presence in this patient was considered to be related to intestinal stasis, and possibly to diarrhea.

Adult↗

Cytokeratin and laminin immunostaining in the diagnosis of cutaneous neuro-endocrine (Merkel cell) tumours.

Nine cutaneous neuro-endocrine tumours have been immunostained with monoclonal antibodies to low molecular weight cytokeratin (CAM 5.2) and neurofilament. Polyclonal antisera to neurone-specific enolase, calcitonin and laminin were also used. All nine cases showed paranuclear, dot-like positive staining with CAM 5.2 and diffuse cytoplasmic staining for neurone-specific enolase. Neurofilament and calcitonin immunoreactivity could not be demonstrated. All tumours were negative for laminin immunoreactivity. The limitations of staining for neurone-specific enolase are discussed and the value of CAM 5.2 in the differential diagnosis of cutaneous neuro-endocrine tumours is emphasized. The histogenetic implications of the absence of laminin staining are considered.

Aged↗

An experimental study of hydrophilic plastics for urological use.

Hydrophilic graft copolymers of polyethylene vinyl acetate (PEVA) were extruded into tubular form. These materials increase both external and internal diameters by 60% on contact with water. The tubes were used as ureteric stents in an experimental study and were superior to silicone stents of the same calibre in the limitation of urinary extravasation. Histological, cytotoxic and electron microscopic studies showed that PEVA is a biocompatible material suitable for clinical use in urology.

Animals↗

Collagenous colitis.

Clinical and pathological aspects of six patients with collagenous colitis are presented. These patients have been observed for between four and 15 years and the evolution of the condition is documented in three (cases 1, 3 and 5). Management and possible pathogenetic mechanisms of this enigmatic condition are discussed.

Adult↗

Eosinophilic infiltrates of the gastrointestinal tract.

There are two lesions which are often confused despite their quite distinct clinical and pathological differences: the inflammatory fibroid polyp and eosinophilic gastroenteritis. Other eosinophilic lesions likely to be encountered in the gut also pose problems of differential diagnosis.

Adolescent↗

Coconut matting bezoar identified by a combined analytical approach.

A rare type of bezoar composed of coconut matting was found in the stomach of a caucasian man. The exact identity of the fibres was established by scanning electron microscopy, x-ray energy spectroscopy, and microscopic infrared spectroscopy. This report illustrates the importance of these techniques for identifying the nature of foreign material.

Adult↗

Concomitant conjugal gliomas with similar histologic features.

Conjugal tumors are rarely reported; but nevertheless, raise important questions of possible etiologic factors. In this report, the presentation of grade 2 gemistocytic astrocytomas in an unrelated married couple in their early thirties within 18 months of each other is described. In both cases the left frontal region of the brain was involved and histologically the tumors were very similar. Although there are no accurate figures on the true incidence of gliomas, an estimate can be derived from reliable epidemiologic studies of primary brain tumors as a whole. Using such data, it is calculated that the risk of two designated persons developing a grade 1 to 2 astrocytoma while in the fourth decade within the same year is approximately 1 in 30 billion (10(9)) and, for this couple, over a period of 15 years, at least 1 in 185 million. No specific causative environmental factors were identified in the patients, and results of conventional tests for viral and other infections were negative. It is postulated that apart from remote chance, such conjugal lesions implicate the action of an environmental agent. In the absence of other factors, involvement of a slow, unconventional virus is a possibility that must be strongly considered.

Adult↗

The effects of double J stenting on unobstructed ureters. An experimental and clinical study.

Upper tract pressure flow studies in four clinically unobstructed ureters with double J stents in situ indicated that urinary flow occurred mainly around the stent and that there was significant vesicorenal pressure transmission. This study examined the dynamics of ureteric urinary flow and morphological effects consequent upon stenting a ureter in vivo. In a porcine model, ureteric intubation caused a rise in intrapelvic pressures, hydroureter, vesicorenal reflux and generalised thickening of the ureteric wall with characteristic histological changes in the urothelium. These findings suggest that double J stents may compromise urinary drainage when ureteric obstruction is not present, urging caution in their use in the damaged, unobstructed upper urinary tract.

Animals↗

Parathyroid carcinoma associated with chronic renal failure and previous radiotherapy to the neck.

Carcinoma of the larynx was treated by irradiation followed by laryngectomy in a man who had been receiving regular haemodialysis for two years. At least one, and probably two, parathyroid glands were removed at this time, and the remaining two were removed three years later for tertiary hyperparathyroidism. A portion of one gland was implanted into the forearm. The forearm implant was resected the following year for recurrent hypercalcaemia. Six years later, again with recurrent hypercalcaemia, he died of bronchopneumonia. Metastatic parathyroid carcinoma was found in the apex of the left lung. The source of this parathyroid tissue and the possible role of irradiation in the pathogenesis of parathyroid cancer in this patient were investigated.

Adult↗