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Biomedical subjects

A Harris

Publications and source records attributed to A Harris.

At least 451 records · Page 25Linked to original sources
PubMed1987

Clinically unsuspected cardiac disease in patients with cerebral ischaemia.

In a 6 month prospective study of 232 patients with cerebral ischaemia, 100 (43%) had a prior history of heart disease. In 22 of the patients with prior heart disease an unsuspected cardiac disorder was subsequently detected (6 atrial fibrillation, 13 cardiomegaly or left ventricular hypertrophy and 3 ischaemic heart disease). In patients without prior heart disease, 47 (20%) were found to have cardiac disease: 6 atrial fibrillation, 31 cardiomegaly or left ventricular hypertrophy 9 ischaemic heart disease and 1 left bundle branch block. Previously unsuspected or asymptomatic cardiac disease is common in patients with cerebral ischaemia.

Adult↗
PubMed1987

Central diabetes insipidus in children. Antidiuretic effect and pharmacokinetics of intranasal and peroral 1-deamino-8-D-arginine vasopressin.

The antidiuretic effect and pharmacokinetics of 10 to 20 micrograms of intranasal (IN) and 200 to 400 micrograms of oral (po) 1-deamino-8-D-arginine vasopressin (DDAVP) were studied in 10 paediatric diabetes insipidus patients. A significant increase in urine osmolality was obtained with all doses, maximum within 2 h and still present at 8 h. At 12 h after administration, the ratio urine osmolality/plasma osmolality was above 1 only after 20 micrograms intranasally and 400 micrograms perorally. The free water clearance decreased rapidly with all doses and was similar in magnitude and duration for both the intranasal and peroral routes of administration and remained negative for more than 8 h. The maximum plasma concentrations of DDAVP, measured with a specific and sensitive RIA method, was dose-dependent and there was not significant difference in time until maximum concentration was obtained or in plasma half-life between the two routes of administration. The ratio established, 1:20, by calculating the area under the curve showed a bio-equivalence between 10 micrograms IN and 200 micrograms po and between 20 micrograms IN and 400 micrograms po of DDAVP. This work further emphasized the effectiveness of the oral route and the rapidity of absorption. By continuous monitoring of DDAVP plasma values we have demonstrated that peak values were reached within one hour after administration. This study demonstrates that the doses needed to treat diabetes insipidus patients by the oral route will be approximately 20 times greater than by the nasal route.

Administration, Intranasal↗
PubMed1987

Cardiac enzyme changes in myxedema coma.

A 74-year-old man with myxedema and hypothermia had increased activities in plasma of creatine kinase (CK; EC 2.7.3.2), aspartate aminotransferase (AST; EC 2.6.1.1), and lactate dehydrogenase (LD; EC 1.1.1.27) and increased proportions of CK-MB (up to 20% of total CK) and LD1 isoenzymes, but no clinical or investigational evidence of associated myocardial infarction. This case illustrates that plasma enzyme activity and isoenzyme profiles in such clinical settings should be interpreted with caution, because increases in CK-MB and LD1 may relate to myxedema coma or hypothermia (or both) rather than to myocardial infarction.

Aged↗
PubMed1986

Response of cranial nerve abnormalities in nasopharyngeal carcinoma to radiation therapy.

Eighteen of 36 patients (50%) with the diagnosis of nasopharyngeal carcinoma had cranial nerve deficits before definitive radiotherapy. Within this group of 18 patients, there were 34 cranial nerve abnormalities and four Horner's syndromes. Overall, 62% of cranial nerve deficits recovered completely (CR) and 32% recovered partially (PR), for a total response rate of 94% to definitive radiotherapy. The magnitude of response (complete versus partial) depended upon the individual cranial nerve and the pretreatment duration of the abnormality. All of the responses except one occurred within 1 month after the completion of therapy. Complete responses were not obtained when deficits had existed longer than 2 months. However, PRs were obtainable. Seven of seven cases of posttreatment new or recurrent cranial nerve deficits were caused by recurrent tumor. The actuarial 5-year disease-free survival for this group of 18 patients was 31%. The results indicate that patients with cranial nerve deficits will respond to definitive radiotherapy and long-term disease-free survival can be achieved in some patients.

Adolescent↗
PubMed1986

The Tasmanian Insulin-treated Diabetes Register. Inception and progress in the first 12 months.

A Statewide register of insulin-treated diabetic patients has been established in Tasmania. The register is the first of its kind in Australasia. Insulin treatment was chosen as the criterion for admission to the register because it was a suitably "hard" end-point, and because the completeness of the register could be validated easily by insulin prescription statistics. Both subjects with insulin-dependent diabetes mellitus and those with non-insulin-dependent diabetes mellitus (who happened to be treated with insulin as of the prevalence date, May l, 1984) are eligible for registration in the prevalent population. Furthermore, no age restrictions have been placed upon entry. It is to be hoped that this all-inclusive policy will assist in the development of an epidemiological definition of insulin-dependent diabetes mellitus. Access to cases has been by hospital records, general practitioners, lay bodies and general publicity. Of over 600 diabetic subjects who were contacted during the first 12 months of the study (approximately one-half of the estimated prevalent population), only three declined to join the register. Once fully established and validated, the register will be used to test aetiological hypotheses in addition to providing descriptive cross-sectional information about diabetes in Tasmania. It is intended that a longitudinal study of insulin-treated diabetes will follow once the cross-sectional information is complete.

Age Factors↗
PubMed1986

The differential diagnosis of dementia using P300 latency.

The P300 component was elicited by an auditory oddball paradigm in 55 normal adults from a wide age range: 19 patients with dementia, 17 patients with depression, and 15 patients with schizophrenia. Normal P300 latency at a given age was predicted by using an age regression equation that had been calculated on the basis of the entire normal sample. Using this procedure, an abnormal delay in latency (greater than 2 SD) was found in approximately 80% of the dementia patients. However, when normal latency was predicted with a slightly greater degree of reliability according to separate equations for adults younger and older than 63 years, an abnormal delay in P300 was found to be less sensitive and specific to dementia. Suggestions for enhancing the diagnostic utility of the P300 component are proposed.

Adolescent↗
PubMed1986

Clinical evaluation of patients with metastatic squamous carcinoma of the neck with occult primary tumor.

Between 1976 and 1982, we systematically evaluated 33 patients with a diagnosis of metastatic squamous carcinoma of the neck (excluding the supraclavicular fossa) from an occult primary tumor. In 11 patients the primary lesion was identified by physical and indirect mirror examinations, in four by examinations done under anesthesia and panendoscopies, and in an additional three by random biopsies. Primary lesions were in the nasopharynx (five patients), hypopharynx (five), tonsillar fossa (three), epiglottis (two), lateral oropharyngeal wall (one), the base of the tongue (one), and the anterior tonsillar pillar (one). In 15 patients (45%), the primary lesion was not identified after complete evaluation; these patients remained free of primary lesions in the head and neck area during a follow-up of two to six years. Our results indicate that patients with metastatic carcinoma of the neck should have a complete evaluation before treatment is started; in the majority of these patients, the primary site can be identified, with a resultant change in the treatment plan. A review of the literature shows that metastatic squamous carcinoma of the neck with an unknown primary tumor is a treatable disease with a cure rate as high as 50%.

Adult↗
PubMed1985

Auditory span of apprehension deficits in schizophrenia.

Previous research on the visual span of apprehension procedure has interpreted the performance deficits commonly demonstrated by schizophrenic subjects as indicative of a core central processing deficit. Little research has directly investigated the existence of similar information-processing deficits in an auditory modality in these patients. In the present study, groups of schizophrenic and nonschizophrenic patients and a comparison group of normal subjects reported the occurrence of a target syllable in the presence of background speech. Schizophrenic subjects performed as well as subjects from both comparison groups in the simpler background conditions, but were significantly less able to identify the target in the presence of auditory distracters when greater amounts of information were available to be processed. These data support the nonmodality specific nature of the deficit.

Adult↗
PubMed1985

Random association of Epstein-Barr virus genomes with host cell metaphase chromosomes in Burkitt's lymphoma-derived cell lines.

The random association of Epstein-Barr virus DNA with host cell metaphase chromosomes of all sizes in Burkitt's lymphoma-derived cell lines was demonstrated by two substantially different techniques, namely fluorescence-activated chromosome sorting and in situ hybridization. The nature and potential importance of this association are discussed.

Burkitt Lymphoma↗
PubMed1985

Serial cell culture and cytogenetic studies of marrow cells from a patient with monosomy 7 syndrome.

Serial bone marrow cell culture studies, with cytogenetic characterization, were performed in an 18-month-old boy with monosomy 7 syndrome--a condition that usually converts to nonlymphoblastic leukemia. Over a 12-month course, his marrow demonstrated: decreased colony formation and increased cluster formation in vitro with disease progression (consistent with preleukemia); persistence of only the monosomy 7 karyotype in direct marrow studies; and in contrast, proliferation of both 46,XY and monosomy 7 cells in in vitro marrow cultures. The findings indicate that certain dormant marrow cell populations may be expressed under in vitro culture conditions and suggest the need for determining factors which would allow their expression in vivo.

Bone Marrow↗
PubMed1984

Cellular distribution of three mammalian Ca2+-binding proteins related to Torpedo calelectrin.

Addition of Ca2+ to post-microsomal fractions of bovine adrenal or liver produced a sedimentable complex of membrane vesicles and cytoplasmic proteins. Proteins with apparent mol. wts. 70 000, 36 000 and 32 500 were solubilized from this complex by Ca2+ chelation. The 36 000 mol. wt. protein (p36) was immunoprecipitated by an antiserum specific for pp36, a major substrate for Rous sarcoma virus src-gene tyrosine kinase. This protein was present in many mesenchymal cells and associated with membrane cytoskeleton of bovine fibroblasts in a Ca2+-dependent manner. The 70 000 and 32 500 mol. wt. proteins were widely distributed in established cell lines, but were not clearly associated with cell organelles in tissue sections, nor retained in cytoskeleton preparations. On immunoblots p36 reacted strongly with antibodies produced against the electric fish protein Torpedo calelectrin and the similar Ca2+-binding properties and subunit mol. wts. of these proteins suggests that they might be functionally related. Since Torpedo calelectrin, p70, p36 and p32.5 were bound by lipid vesicles or microsomal membranes at micromolar free Ca2+ concentrations, regulated association with intrinsic membrane components may be involved in the functions of these widespread proteins.

Adrenal Medulla↗