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Biomedical subjects

D E Powell

Publications and source records attributed to D E Powell.

At least 73 records · Page 4Linked to original sources
PubMed1982

Reversible hepatotoxicity associated with hepatic vitamin A accumulation in a protein-deficient patient.

A 62-yr-old white male presented with edema, protein malnutrition, and abnormal liver function. He had ingested from 40,000-50,000 IU of vitamin A per day for 7 yr. Examination of liver tissue by light and electron microscopy revealed findings characteristic of an excessive accumulation of vitamin A. Liver tissue contained massive amounts of vitamin A (19,000 IU/g); however, both the serum concentration of vitamin A and retinol-binding protein were below normal, and serum RBP was not saturated. On a normal diet the patient was able to mobilize hepatic vitamin A, as indicated 71 days later by a repeat biopsy of the liver, which then contained 9000 IU of vitamin A/g. During this time his nutrition improved, serum vitamin A rose, and serum RBP became transiently saturated. The amount of vitamin A ingested by this patient was less than that usually producing recognizable hepatotoxicity, and he had no extra hepatic manifestations of vitamin toxicity, consistent with a low serum vitamin A concentration and a low vitamin A to retinol-binding protein ratio. At presentation he was apparently unable to normally mobilize vitamin A from his liver, which may have been due to an accompanying protein deficiency.

Biopsy↗
PubMed1980

Placental chorioangioma: presentation of a case with electron-microscopic and immunochemical studies.

A case of placental chorioangioma in an infant who experienced transient congestive heart failure is presented. The mechanism for this heart failure was probably due to excessive left to right shunting of blood across the tumor. Electron-microscopic examination revealed the tumor to be composed of endothelial cells and vascular structures of different types. Immunochemistry revealed the lack of normal placental antigens indicating that these tumors are not composed of trophoblastic tissue.

Adult↗
PubMed1979

Leukaemia classification: a study of the accuracy of diagnosis in 456 patients.

A panel of five haematologists has examined, without consultation or prior knowledge of the diagnosis, blood films and bone marrow smears from 456 patients with a diagnosis of leukaemia. A diagnostic classification which recognized various subtypes of acute myelogenous leukaemia was used but no attempt was made to subdivide acute lymphoblastic leukaemia. Complete agreement with the initial diagnosis was low (56.4%) and was particularly poor (45.7%) when the patient had one of the forms of acute leukaemia. However, disagreements which would have involved the patient in a change of treatment were unusual (2.0%). We conclude that a high degree of diagnostic agreement for patients with leukaemia is unlikely from morphological classifications alone.

Diagnosis, Differential↗
PubMed1979

Assessment of chemical tests for faecal occult bleeding and correlation of results with presence or absence of anaemia.

Stools from 88 consecutive patients in acute geriatric wards were tested for occult blood by four common commercial methods. The Peroheme and Haemostix tests were found too sensitive for general use, the Okokit and Haemoccult tests being preferable. Positive tests were correlated with anaemia in 27 patients, iron deficiency in 26, iron deficiency anaemia in 15, non-anaemia in 52, non-iron deficiency in 43 and with absence of both in 27. Such testing has been considered unnecessary in anaemic patients without gastrointestinal symptoms.

Aged↗
PubMed1979

Abnormalities of hepatic mitochondrial urea-cycle enzyme activities and hepatic ultrastructure in acute fatty liver of pregnancy.

Two patients presenting with acute fatty liver of pregnancy were studied. Because of similarities between acute fatty liver of pregnancy and Reye's syndrome, we investigated hepatic ultrastructure, urea-cycle enzyme activities, and plasma amino acids. Initial liver biopsies obtained 12 and 21 days after the onset of illness demonstrated microvesicular fat deposition and mitochondrial ultrastructural changes, including pleomorphism and abundant crystalline inclusions. In both biopsies, activity of the mitochondrial urea-cycle enzyme OTC was markedly below normal limits. Activity of the other mitochondrial urea-cycle enzyme, CPS, was low in one patient. Abnormalities of these enzymes persisted in second biopsies obtained at 9 and 28 weeks, respectively. By 44 weeks all urea-cycle enzyme activities had returned to normal in one patient. However, in the other patient OTC activity was still reduced at 52 weeks, although it had doubled in comparison to previous biopsies. Morphological changes of the mitochondria generally improved in parallel with the urea-cycle enzymes. Plasma amino acids, obtained at the time of the initial biopsies, demonstrated a generalized hypoaminoacidemia with the exception of glutamate. Serial observations in patients with this rare disease indicate that there are similarities with Reye's syndrome, in particular, reduced activity of the mitochondrial urea-cycle enzymes. But there are important differences. (1) Enzymatic and ultrastructural abnormalities of mitochondria persist for a longer period of time than in Reye's syndrome. (2) Mitochondrial ultrastructure is different. (3) Plasma amino acid profiles are different.

Acute Disease↗