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Biomedical subjects

J Jensen

Publications and source records attributed to J Jensen.

At least 307 records · Page 17Linked to original sources
PubMed1991

Latent class analysis of organic aspects of obsessive-compulsive disorder in children and adolescents.

Organic aspects of obsessive-compulsive disorder (OCD) have previously been described and hypotheses of biological etiology have been suggested. Sixty-one patients, 8-17 years of age, who fulfilled the DSM-III criteria for OCD in a review of the records were compared with 117 matched control patients for organic features. The indicators chosen for an organic concept were neurological signs, more than mild electroencephalographic abnormality, specific developmental disorder and attention deficit, and their defining property of an organic concept was confirmed by latent class analysis. Neurological signs was the most sensitive and specific indicator. Significantly fewer OCD children than control patients were assigned to the organic class. Almost all the types of obsessive-compulsive symptoms were more related to the non-organic class. Such extroverted symptoms as behavioral problems and loss of temper were significantly more frequent in patients assigned to the latent organic class, whereas symptoms of phobia and depressive mood were more often present in patients belonging to the nonorganic class. No difference was found between OCD patients and controls as to frequency of birth complications. The findings do not support the evidence of OCD having signs of major cerebral disturbance found by conventional neuropediatric methods.

Adjustment Disorders↗
PubMed1991

Dimensional approach to obsessive-compulsive disorder in childhood and adolescence.

Based on a review of the charts of child and adolescent psychiatric patients, a group of patients with obsessive-compulsive symptoms and a control group were identified. Obsessive-compulsive symptoms described in the charts were classified according to form using the checklist of Khanna et al. By use of latent trait models, a 6-item obsessive-compulsive rating scale was established revealing a dimensional rather than a categorical distribution of obsessive-compulsive symptoms. The correlation with other clinical features was investigated.

Adjustment Disorders↗
PubMed1991

Corrosion investigation of two materials for implant supraconstructions coupled to a titanium implant.

The corrosion of two materials for implant supraconstructions, a carbon fiber/PMMA composite and a silver-palladium alloy, was investigated in vitro, the materials being galvanically coupled to a titanium implant. Corrosion current and pH of the electrolyte were monitored, and corrosion products were identified by powder X-ray diffraction. The carbon composite and the silver-palladium per se did not corrode, whereas a silver-palladium specimen brazed with the recommended brazing alloy corroded unmistakably, yielding copper-containing corrosion products. The action of local corrosion cells around the brazed joint is considered, and it is concluded that the two materials seem well suited for implant supraconstructions, provided that brazing the silver-palladium can be avoided. Considering the clinical relevance of the experimental model used, it is concluded that the model is likely to predict a lower corrosion susceptibility than the one found in vivo.

Carbon↗
PubMed1991

Should aerobic blood cultures be shaken intermittently or continuously?

Stationary incubation of aerobic blood cultures was compared with intermittent shaking in aerobic Vacutainer 2630 bottles with agar slants during the first 24 h, and was simultaneously compared with the continuously shaken aerobic Bactec 6A bottles as a reference system. Intermittent shaking did not significantly increase or decrease the seven days yield of the Vacutainer bottles as compared with the continuously agitated Bactec 6A bottles. When one of 604 paired Vacutainer bottles was agitated for eight h and the other incubated stationary, the speed of growth detection was significantly greater in the agitated bottle (p less than 0.001), but significantly less than with continuously agitated Bactec 6A bottles (p less than 0.001). Agitation for 14 h showed the same pattern of detection speed. These results suggest that it is desirable initially to agitate aerobic blood cultures either intermittently or continuously.

Aerobiosis↗
PubMed1991

Darkening of haemoglobin in simulated, continuously agitated aerobic blood cultures: an early indicator of bacterial growth.

The change of purple oxyhaemoglobin to the darker reduced haemoglobin and methaemoglobin was used as an initial visual growth indicator in continuously agitated, aerobic Colorbact bottles after inoculation with a broad assortment of aerobic and facultatively anaerobic bacteria previously isolated from blood cultures. Growth of all the faster growing strains could be detected by darkening of the blood cultures within a 24 h period of agitation, after they had stood unshaken for eight h. The darkening was accompanied by consumption of O2 and acidification of the fluid media. The slower growing bacteria were detected by turbidity. This growth detection method is easy, quick, inexpensive and reliable, and is especially promising for application in clinical microbiological departments which daily receive blood cultures from peripheral hospitals.

Aerobiosis↗
PubMed1991

Colorbact, a visually read blood culture system using darkening of haemoglobin in aerobic blood cultures as an early growth indicator, compared with Bactec 6A and 7A.

Colorbact-A (aerobic), a blood culture system using darkening due to oxygen reduction and acidification of haemoglobin as an initial growth indicator during the first day of incubation of continuously agitated, aerobic blood cultures, was compared with the 24 h agitated aerobic Bactec 6A in 1767 consecutive paired cultures. Both systems were examined simultaneously twice daily during the first two days and once daily the next five days of incubation. In addition, during the agitation period Colorbact-A was observed for darkening four to five times during day duty between 8 a.m. and 4 p.m. The final seven days detection rate found by Colorbact-A using observation for darkening during initial agitation was similar to the rate found by Bactec 6A for both clinically significant strains and "contaminants", but Colorbact-A was significantly faster (p less than 0.001) in finding clinically significant strains. Colorbact-AN (anaerobic) was more rapid (p less than 0.01) and yielded more positive cultures than the anaerobic Bactec 7A. The Colorbact system was flexible, inexpensive, reliable and especially promising for laboratories which receive blood cultures from other hospitals once daily, as many positive cultures can be found immediately on arrival undisturbed by agitation during transport.

Aerobiosis↗
PubMed1991

Genetic parameters of growth, feed intake, feed conversion and carcass composition of dual-purpose bulls in performance testing.

Genetic parameters for growth, total energy intake, feed conversion ratio, average daily energy intake and carcass composition were estimated in an experiment with 650 bull calves from 31 half-sib groups of Holstein Friesian or Brown Swiss sires. All traits analyzed had an amount of additive genetic variance that allows for considerable response to selection. No interaction between genotype (sire group) and proportion of roughage in the diet was found. Daily gain was strongly correlated negatively with feed conversion ratio but positively correlated with daily energy intake. Results indicate that genetic selection for either daily gain or average daily energy intake would decrease carcass fatness at a constant slaughter weight. However, the environmental correlation between daily energy intake and carcass fatness was positive.

Animals↗
PubMed1991

Clearance of xenon-133 from bone marrow in patients with small-cell lung cancer.

The aim of this study was to estimate bone-marrow blood flow (BMBF) in man and to correlate this with myelosuppression induced by cytostatic treatment dosed as a function of surface area. Twenty-four patients suffering from small-cell lung cancer participated in the study. Blood flow was measured with the xenon-133 washout technique. The 133Xe clearance measurement took place in conjunction with the pre-treatment bone-marrow staging procedure (ad modern Radner). Tissue samples were taken for microscopy and for the determination of the blood-to-tissue partition coefficient lambda. After the bone-marrow aspiration, 0.1-0.2 ml of 133Xe in saline was injected into the bone marrow and the cannula was removed. Following a hyperaemic phase of 12 min (7-16 min), monoexponential washouts were demonstrated. The median washout rate constant was 0.0063 min-1 (0.0038-0.0098 min-1). Lambda values of 0.3-3.5 ml g were found, but microscopy of the bone marrow showed a fairly large admixture of peripheral blood. Therefore, the lambda values should be taken with caution and absolute blood-flow values were not calculated. The results demonstrated no correlation between 133Xe clearance from crista iliaca and leucocyte or platelet suppression.

Aged↗
PubMed1991

Heterotopic bone formation following hip arthroplasty. A retrospective study of 65 bilateral cases.

Heterotopic bone formation after two-stage bilateral cemented total hip arthroplasty was evaluated in 65 patients (23 women and 42 men) who had not received treatment with antiinflammatory drugs in the immediate postoperative weeks. The mean age at the first operation was 65 years, and the median interval between the two arthroplasties was 3 months. Fifty-two patients developed heterotopic ossification after the initial hip arthroplasty. Of these patients, 40 also developed ossifications after contralateral hip arthroplasty. Out of 11 males developing Grade-III heterotopic ossification after the initial hip arthroplasty, 8 also developed Grade-III ossification after contralateral hip arthroplasty. Two females developed Grade-III ossification after the initial arthroplasty, but neither of them developed a Grade-III lesion after contralateral total hip arthroplasty. Males with Grade-III heterotopic ossification after the initial hip arthroplasty were shown to be at a high risk of developing the same severe lesion after contralateral total hip arthroplasty, making them candidates for postoperative prophylaxis.

Aged↗
PubMed1991

Estimation of genetic parameters using sampled data from populations undergoing selection.

In populations undergoing selection, genetic (co)variances may be altered in amounts dependent on selection intensity among parents and the mating structure. In order to estimate the genetic parameters of the unselected population, all information that led to the current population must be included in the analysis. This is often not possible due to missing information or computer limitations, and, therefore, only samples of data and pedigree information of recent generations are included in analysis, and simplified operational models are used. Biases in genetic parameters, which were estimated by multitrait derivative-free REML method, were investigated in different strategies of sampling data and pedigree. In dual purpose cattle, in which young bulls are selected for growth before being progeny tested for milk yield, heritabilities and additive genetic correlations were all unbiased when all data and all relationships were used in an animal model. Using only recent data but all relationships in an animal model also gave unbiased estimates of heritabilities. Using an animal model for growth but a sire model for milk with all data gave an unbiased estimate of heritability for milk. When only recent data were used, the heritability estimate for milk was biased downward. In single purpose dairy populations, sire models gave biased estimates of genetic parameters even when all data were included in the analysis. Treating sire effects on second crop of daughters as fixed did not overcome selection bias.

Algorithms↗
PubMed1991

Functional significance of the oligomeric structure of the Na,K-pump from radiation inactivation and ligand binding.

The present article is concerned with the oligomeric structure and function of the Na,K-pump (Na,K-ATPase). The questions we have addressed, using radiation inactivation and target size analysis as well as ligand binding, are whether the minimal structural unit and the functional unit have more than one molecule of the catalytic subunit, alpha. We first discuss the fundamentals of the radiation inactivation method and emphasize the necessity for rigorous internal standardization with enzymes of known molecular mass. We then demonstrate that the radiation inactivation of Na,K-ATPase is a stepwise process which leads to intermediary fragments of the alpha-subunit with partial catalytic activity. From the target size analysis it is most likely that the membrane-bound Na,K-ATPase is structurally organized as a diprotomer containing two alpha-subunits. Determination of ADP- and ouabain-binding site stoichiometry favors a theory with one substrate site per (alpha beta)2.

Animals↗
PubMed1990

Regional differences in the activation of synaptosomal mitochondrial Ca2+ uptake by spermine in rat brain.

Several properties of Ca2+ uptake by isolated synaptosomal mitochondria were characterized by using a repetitive Ca2+ loading technique. Synaptosomal mitochondria maintained extramitochondrial Ca2+ concentration at submicromolar levels when challenged with successive additions of small amounts of Ca2+. Ca2+ uptake under these conditions was markedly stimulated by the presence of spermine, a polyamine found in high concentrations in brain. Moreover, mitochondria isolated from telencephalic areas of rat brain were activated to a greater extent by spermine than were mitochondria from non-telencephalic brain regions. The present results support the idea that brain mitochondria could play a significant role in limiting the intraneuronal rise in Ca2+ that follows stimulation or injury. In addition, telencephalic mitochondria exhibit more flexibility in the regulation of Ca2+ uptake than do mitochondria from phylogenetically older non-telencephalic brain regions and this could be related to differences in Ca2+ influx mechanisms in these brain regions.

Animals↗
PubMed1990

Double contrast barium enema and flexible rectosigmoidoscopy: a reliable diagnostic combination for detection of colorectal neoplasm.

The efficiency of double contrast barium enema and flexible rectosigmoidoscopy (to 60 cm) in the assessment of patients with a positive Hemoccult II test in a randomized screening study for colorectal neoplasms was evaluated. A positive test was present in 625 patients, of whom 530 had a complete enema and rectosigmoidoscopic assessment. A carcinoma was diagnosed in 26 and an adenoma greater than or equal to 1 cm in diameter in 71. As a control, 323 patients with a negative assessment repeated the Hemoccult II test and of these 67 had a positive second test, of whom 55 underwent colonoscopy. One carcinoma (Dukes' A) and two adenomas greater than or equal to 1 cm in diameter were diagnosed. The efficiency of the assessment was also checked by rescreening the whole group 1-2 years after the first study and by continuing follow-up. It was found that two more carcinomas and one adenoma greater than or equal to 1 cm in diameter had been overlooked at the primary assessment. The sensitivity for neoplasms greater than or equal to 1 cm in diameter at the primary assessment was 72 per cent for double contrast barium enema and 86 per cent for rectosigmoidoscopy. The sensitivity for the combined methods was 94 per cent and the specificity was 99 per cent. The combination of double contrast barium enema and rectosigmoidoscopy in the primary assessment of patients with a positive Hemoccult II test gives an acceptable result and immediate retesting of those with a negative assessment is not necessary.

Adenoma↗
PubMed1990

Value of retesting subjects with a positive Hemoccult in screening for colorectal cancer.

Within a prospective randomized screening study for early detection of colorectal cancer with rehydrated Hemoccult II test, the possibility of increasing the specificity of the test by retesting patients with an initially positive Hemoccult II test was investigated. Of those offered the test 3561 (62.6 per cent) returned it and it was positive in 210 cases (5.9 per cent). The repeat test was performed by 184 patients and was positive in 68 (1.9 per cent). All those with a positive initial test had rectosigmoidoscopy to 60 cm and a double contrast enema. A carcinoma was found in one in seven patients with a positive retest but in only one in 100 patients with a negative retest (P less than 0.001). The specificity of the test was, therefore, increased from 95 per cent to 98 per cent and the sensitivity was unchanged. Rescreening was offered at a later date and increased numbers were available: 7147 patients returned the test and 369 (5.2 per cent) were positive. The test was repeated in 360 patients and 118 (1.7 per cent) were positive. A colorectal neoplasm was found in one in three of those with a positive repeat test, compared with one in seven of those with a negative repeat test. In conclusion, screening for early detection of colorectal cancer with a rehydrated Hemoccult II test may be followed by investigation of only those patients with a positive retest. Such a procedure will reduce the work-load by 60 per cent without reducing sensitivity.

Barium Sulfate↗
PubMed1990

Missed injuries in an orthopaedic department.

In a prospective study lasting 6 months, all missed injuries in patients visiting the casualty department or admitted to the orthopaedic department of Aarhus Amtssygehus were registered and analysed. A total of 15,806 patients attended the casualty department and 783 patients were admitted to the orthopaedic department. Eighty-four injuries were missed in 83 patients in the casualty department, making a missed injury rate of 0.5 per cent. Twenty-three injuries were missed in 17 patients in the orthopaedic department making a missed injury rate of 2.2 per cent. Re-examination of all patients and matching radiographs reduced the number of missed injuries significantly.

Adolescent↗