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Biomedical subjects

H Christensen

Publications and source records attributed to H Christensen.

At least 181 records · Page 10Linked to original sources
PubMed1995

Trophic effects of biosynthetic growth hormone on normal and defunctioned left colon in rats.

BACKGROUND: In rats with diverting colostomies the effects of growth hormone can be differentiated from the actions of fecal passage. METHODS: After sham operation or diverting colostomy rats were treated with biosynthetic growth hormone (b-hGH) for 4 weeks. RESULTS: In defunctioned colon of b-hGH-treated rats there were increases in mucosal surface area and the weight of mucosa and muscularis propria compared with the atrophic colon of saline-treated rats. The breaking strength of defunctioned colon rings was greater and the defatted dry weight and hydroxyproline content of these specimens were also increased. In intact colon b-hGH stimulated luminal surface area, the weight of mucosal and submucosal layers, and the hydroxyproline content compared with controls. The breaking strength was highest in specimens from saline-treated rats. CONCLUSIONS: B-hGH has a growth-promoting role throughout the whole thickness of the colonic wall in rats also in the absence of fecal passage.

Animals↗
PubMed1995

Ultrastructural studies of the megakaryoblastic leukemias of Down syndrome.

The ultrastructure of the leukemic cells in transient leukemia (six cases), myelodysplasia (five cases) and acute megakaryoblastic leukemia (one case) in patients with Down syndrome were studied. The cells were identified to be of megakaryocytic lineage by virtue of the expression of platelet glycoprotein GpIIIa, detected by immunogold labelling. In all patients, some of the leukemic cells had ultrastructural features of megakaryocytes, including ectoplasmic protrusions, demarcation membranes, and alpha granules. Differentiation was greatest in the cells of patients with transient leukemia. These studies provide a detailed assessment of the ultrastructural features of the leukemic cells in the megakaryoblastic leukemias of Down syndrome.

Acute Disease↗
PubMed1995

Immunogold labeling for the diagnosis of leukemia by transmission and scanning electron microscopy.

For the cell type diagnosis of leukemia in adult patients, particularly when the sampling of bone marrow is difficult, the study of peripheral blood leukocytes (PBLs) by immuno-electron microscopy provides significant information, as illustrated here in two cases of hairy cell leukemia and seven cases tentatively identified as megakaryoblastic leukemia (M7). Indirect immunogold labeling with the B-ly7 monoclonal antibody (CD103) proved valuable in confirming the diagnosis of hairy cell leukemia. Immunogold labeling for the GpIIIa platelet glycoprotein (CD61) was used in cases where the light microscopy of blood films revealed possible megakaryoblastic leukemia. Under the electron microscope, however, the CD61 positive cells showed, in almost all cases, a wide spectrum of megakaryopoietic differentiation which made the diagnosis of M7 questionable. Most of the CD61 positive cells featured cytoplasmic differentiation markers such as alpha granules and demarcation membranes, further confirming the presence of circulating megakaryocythemia, a phenomenon described many years ago in various myeloproliferative disorders. It is suggested, therefore, that many of these cases should not be identified as true megakaryoblastic leukemias.

Humans↗
PubMed1994

Immunogold labelling of leukemic hairy cells with the B-ly7 monoclonal antibody: an SEM and TEM study.

Two cases of hairy cell leukemia have been studied by immuno-TEM and immuno-SEM after immunogold labelling of the cell surface antigen recognized by the B-ly7 monoclonal antibody. Most hairy cells appeared significantly labeled, although the density of the expression of the antigen, as demonstrated by immunogold labelling, seems variable from cell to cell. Moreover, some cells with the morphology of hairy cells and which could not be identified as monocytes were not labeled. Labelling for the antigen identified by the B-ly7 mAb does not seem to correlate with the presence of ribosome lamellae complexes which were present only in one of the two cases studied. Rare lymphocytes of unidentified lineage were labeled. Monocytes were significantly absent from the samples of peripheral blood of the two patients studied. In one normal control sample, monocytes were observed unlabelled. The results are discussed in reference to the pathogenesis of hairy cell leukemia, its surprisingly low mitotic rate, and its distinct response to chemotherapy.

Adult↗
PubMed1994

Efficacy of tacrine and lecithin in mild to moderate Alzheimer's disease: double blind trial.

OBJECTIVE: To assess the efficacy of tacrine and lecithin in treating Alzheimer's disease over nine months. DESIGN: Double blind randomised controlled trial. SETTING: Outpatients clinic of university department of geriatric medicine. SUBJECTS: 53 subjects (26 women, 27 men) with probable Alzheimer's disease. 41 completed the dose finding phase and were randomised to treatment. 32 (14 tacrine, 18 placebo) completed nine months' treatment. INTERVENTIONS: Lecithin and tacrine or lecithin and placebo for 36 weeks. MAIN OUTCOME MEASURES: Scores on neuropsychological tests sensitive to deficits in the cholinergic system; mini-mental state score; behaviour change; mood; functional state; and stress in carers. RESULTS: The tacrine and placebo groups were similar except that the tacrine group had a longer duration of disease (mean 5.4 v 2.5 years in placebo group; P = 0.003). Only 17 of the 32 patients could tolerate the maximum dose of tacrine (100 mg). No significant difference was found between the groups for any of the tests after nine months' treatment except for the digit backwards test, which is insensitive to cholinergic deficit. Analysis of subjects taking the maximum dose of tacrine and of subjects with mild dementia also found no differences. CONCLUSIONS: Tacrine produces no clinically relevant improvement over 36 weeks at the doses tolerated by these patients.

Activities of Daily Living↗
PubMed1994

[Potassium channel openers. A new possible therapeutic principle in several diseases].

Potassium channels are ion channels in the cell membrane which are especially important for regulation of the membrane potential and the cell's excitability. Potassium channel openers are drugs that interfere with these channels, and several such substances have been developed. Existing substances show highest affinity to vascular smooth muscle. The clinical effect is relaxation of blood vessels resulting in lower blood pressure. However, current efforts are concentrated on finding substances which are selective for other cell types. Possible areas of application are treatment of hypertension, angina pectoris, arrhythmias, asthma and urinary bladder instability.

Antihypertensive Agents↗
PubMed1994

The great escape: a neuropsychological study of psychogenic amnesia.

This paper describes the neuropsychological test performance of a patient who experienced a "fugue" episode (functional retrograde amnesia) lasting 7 days, but who continued to complain of a virtually complete loss of autobiographical memory for well over a year. Subsequent evidence revealed that she had been at least partially simulating her amnesia during this prolonged period. Neuropsychological testing took place soon after admission to hospital, at intervals thereafter, and after an Amytal abreaction, which produced a substantial recovery of her memories. On various anterograde tests, designed to detect simulation, the patient's performance was unimpaired, including recognition memory tasks, word-stem completion priming for "neutral" word-lists and for post-onset autobiographical material, and some aspects of semantic memory. However, her pattern of performance on an autobiographical and a remote News Event test differentiated her from patients with organic amnesia, because she showed a grossly disproportionate autobiographical memory loss and an extreme recency effect. In addition, a rating scale, on which she showed impaired feelings-of-knowing for items from her autobiographical memory, suggested simulation. On a word-completion task for pre-onset autobiographical material, she showed absent "priming" relative to "baseline" material. However, following the Amytal abreaction, there was a substantial improvement on this task, relative to recognition and cued recall performance. This finding has been interpreted within an hierarchical model of awareness in memory, derived from studies of normal memory and organic amnesia; and it is suggested that patients with "psychogenic amnesia" may manifest different levels of awareness for differing memories.

Adult↗
PubMed1994

Myelodysplasia and acute megakaryoblastic leukemia in Down's syndrome.

In this report we describe the clinical and hematologic features of 23 cases of myelodysplasia (MDS) or acute megakaryoblastic leukemia (AMKL) occurring in Down's syndrome. MDS was characterized by thrombocytopenia, abnormal megakaryocytopoiesis, megakaryoblasts (< 30%) in the marrow and abnormal karyotype, the most common of which was trisomy 8, found in 7/15 patients with MDS. Three of five patients achieved a complete remission with low dose cytosine arabinoside, vincristine and retinyl palmitate. The high cure rate and the distinctive features of the leukemic process in these cases suggest that this type of MDS and AMKL are unique to patients with Down's syndrome.

Adolescent↗
PubMed1994

The role of neuroimaging in the initial management of patients with minor head injury.

STUDY OBJECTIVE: To determine whether omitting neuroimaging in the primary assessment of patients with minor head injuries in the emergency department is safe. DESIGN: Prospective cohort study. SETTING: University hospital, Copenhagen County Hospital, Glostrup, Denmark. PARTICIPANTS: The study group consisted of 2,204 patients presenting to the ED after sustaining minor head injuries. Only patients able to talk and walk were included. MEASUREMENTS AND MAIN RESULTS: The decision to admit was based exclusively on clinical guidelines in which the findings in the ED were of highest priority. Seven patients (0.3%) had a skull radiograph; computed tomography was not used in the primary evaluation. Four hundred thirty patients (19.5%) were admitted. After hospitalization, four patients developed intracranial complications. One required surgery, two required hyperventilation, and one was observed. Follow-up demonstrated that no patient with an intracranial complication had been missed. CONCLUSION: We found it safe to exclude neuroimaging in the primary assessment of patients with minor head injuries in the ED, and to rely instead on clinical criteria.

Adolescent↗
PubMed1994

Do mental health surveys disturb? Further evidence.

In a community survey of 873 persons aged 70 years or over, focusing on dementia, cognitive decline, depression, and current life circumstances, we included an enquiry into the emotional impact of the interview. A large majority reported at the end of the interview that it had no adverse effect on their emotional state. About 4% reported that it made them distressed, 1% that it depressed them, and 2% that it had intruded on their privacy. By contrast, 52% said it had made them feel good about themselves. Distress seemed to be largely related to performing poorly on cognitive tests. There is no information on the duration of these effects in the period following the interview. It is recommended that respondents in community surveys, including the elderly, be informed that they can decline to answer any question, and that interviewers be trained in how to respond to the few who will be distressed by the experience.

Aged↗
PubMed1994

Complaints of cognitive decline in the elderly: a comparison of reports by subjects and informants in a community survey.

In a community survey, subjects and their informants were asked the same questions about memory and intellectual decline in the subjects. Subjects and informants both commonly reported cognitive decline, although in most cases the decline was not seen as interfering with daily life. However, when responses from subjects and informants were cross-tabulated, agreement was found to be poor. For subjects, reports of cognitive decline were correlated with anxiety and depression symptoms and with trait neuroticism. Subjects' reports were uncorrelated with age and only weakly correlated with cognitive test performance, indicating little validity. By contrast, informants' reports were correlated with the subjects' cognitive test performance and age, but also with the informants' own anxiety and depression symptoms. Although informants' reports have validity, they may also be contaminated by the informants' affective state.

Aged↗
PubMed1994

A survey of dementia in the Canberra population: experience with ICD-10 and DSM-III-R criteria.

A community survey of 1045 persons aged 70 years and over was conducted to identify cases of dementia in the cities of Canberra and Queanbeyan. Cases were identified using the Canberra Interview for the Elderly, administered by lay interviewers. When diagnostic criteria were rigidly applied, the point prevalence of dementia in the combined sample of community and institutional residents was considerably lower by ICD-10 than by DSM-III-R. Both criteria showed a similar rise in prevalence with age, and no gender difference. Agreement between the two systems had a kappa of only 0.48. 'Probable' cases by either criteria were identified solely from respondent-provided information in order to include persons for whom no informant was available. The point prevalence of such 'probable' cases was more similar for the two systems, and the kappa coefficient of agreement rose to 0.80. Analysis of the various components required for a diagnosis of dementia showed that the prevalence of all increased with age. Components involving cognitive assessment were correlated with education, but other components were not. The results of the study point to important differences between ICD-10 and DSM-III-R diagnoses of dementia.

Aged↗
PubMed1994

A latent trait analysis of an inventory designed to detect symptoms of anxiety and depression using an elderly community sample.

An 18-item inventory designed by Goldberg et al. (1987) to detect symptoms of anxiety and depression was administered to an elderly general population sample. Latent trait analysis was used to assess the dimensionality of the inventory and the location and discriminatory ability of the symptoms. The items showed different patterns of discrimination in this group compared to the sample of general practice attenders on which the inventory was developed. Overall, the items did define two correlated dimensions of anxiety and depression. In addition, a third dimension of sleep disturbance was detected. Both individual scales and the total symptom scores were sensitive and relatively specific detectors of depressive disorders assessed according to ICD-10 and DSM-III-R criteria. The retention of sleep items on their original scales did not affect the sensitivity of the scales to detect depressive disorders. A two-step administration procedure suggested for use in the administration of the scales was investigated but found to be sensitive to differences between the current sample and the sample on which the inventory was developed. This symptom inventory can be recommended for use in epidemiological investigations as a brief, valid and acceptable method of detecting elevated levels of anxiety and depression in elderly persons.

Aged↗
PubMed1994

Age differences and interindividual variation in cognition in community-dwelling elderly.

The cognitive test performance of 897 community-dwelling elderly Ss, aged 70 years and over, was examined for age trends and interindividual variation. Data were subjected to factor analysis, and 3 factors emerged (Crystallized Intelligence, Fluid Intelligence, and Memory). Over the age span sampled, Crystallized Intelligence, Fluid Intelligence, and Memory all decreased with the decrease being greatest for Fluid Intelligence and least for Crystallized Intelligence. Interindividual variation increased for Fluid Intelligence and Memory, but not for Crystallized Intelligence. These findings give support to the view that crystallized intelligence is lower in the very old and that there is a greater degree of variability in test performance with advancing age.

Activities of Daily Living↗
PubMed1994

The relationship between health and cognitive functioning in a sample of elderly people in the community.

The association between health status and cognitive performance was examined in a sample of 708 community dwelling elderly people aged 70 years or over. Cognitive performance declined significantly across the age groups 70-74, 75-79, 80-84, and 85-89 years on the Mini-Mental State Examination and on measures of fluid intelligence and memory, but not on measures of crystallized intelligence. Health status declined significantly across age for five of 49 past and current medical conditions, for measures of Activities of Daily Living (ADL) and for systolic blood pressure, but did not decline significantly for global self-ratings of health, diastolic blood pressure or reports of smoking. Weak but significant correlations between health and cognitive performance were found for self-reported global ratings of health and for self-reports of some physical symptoms but not for diastolic or systolic blood pressure, or for many other physical conditions. Both self- and informant-based ratings of ADL correlated with cognitive performance. Age differences remained after cognitive performance was adjusted for health variables such as ADL, self-ratings of health and current health problems. It is concluded that, at the population level, lower levels of cognitive performance in community-dwelling elderly subjects are not strongly mediated by ill health.

Activities of Daily Living↗
PubMed1994

Analysis of fluorescent pseudomonads based on 23S ribosomal DNA sequences.

The regions from positions 1391 to 1545 and 1620 to 1865 (Escherichia coli numbers) of the 23S ribosomal DNA sequences have been analyzed for a number of Pseudomonas fluorescens and P. putida isolates. Variability was observed only in three smaller regions from positions 1484 to 1508, 1531 to 1542, and 1714 to 1748, corresponding to helices 58, 59, and 63, respectively, where up to 53% dissimilarity was found. Sequence analysis did not allow clear distinctions among P. fluorescens biovars, P. chlororaphis, and P. putida biovar B.

Base Sequence↗