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Biomedical subjects

J K Larsen

Publications and source records attributed to J K Larsen.

At least 145 records · Page 8Linked to original sources
PubMed1983

Aneuploidy in cutaneous T-cell lymphoma.

A new method is described which makes it possible using skin specimens to perform flow cytometric analysis of DNA content. DNA content analysis was performed on 28 skin specimens and 9 blood samples from 18 patients with mycosis fungoides and Sézary syndrome. The reproducibility was fair, with almost identical results in 6 cases (mycosis fungoides and Sézary syndrome) where two samples (skin specimens or blood samples) were taken 6 hours to 10 days apart. Hyperdiploidy was found in 7 of 11 skin specimens from patients with mycosis fungoides stage I with negative histology. In 13 skin specimens and 3 blood samples from patients with mycosis fungoides stages II and IV, abnormalities including hyperdiploidy, near-tetraploidy and near-hexaploidy were found in 8 of 13 skin specimens and in 2 of 3 blood samples. Four patients with Sézary syndrome were studied: 2 patients in remission showed normal DNA histograms (2 skin specimens, 3 blood samples) and 2 patients with active disease showed aneuploidy in the 2 skin specimens examined and in 1 of 3 blood samples. These studies demonstrate: 1) the importance of flow cytometry as a diagnostic tool for use on skin specimens in the early stages of mycosis fungoides where routine histology is non-diagnostic; 2) the diagnostic and prognostic aid of flow cytometry during the course of mycosis fungoides and Sézary syndrome in addition to the probability of measuring the effect of treatment.

Adult↗
PubMed1983

Chronic lymphocytic leukaemia of T cell origin. Clinical variation possibly due to involvement of different T lymphocyte subpopulations.

Based on the literature and 2 patients studied, we suggest that at least 2 different clinical entities are included in the concept of T CLL: (i) a clinical variant characterized by a relatively benign course, splenomegaly without lymphadenopathy, low lymphocyte count and granulocytopenia; the proliferating lymphocyte is morphologically mature, of medium size and a cytoplasm with azurophilic granules staining positively for acid phosphatase and corresponding to parallel tubular arrays as demonstrated by electron microscopy. The cells form E-rosettes, have no surface-membrane-bound Ig, but Fc-receptors for IgG. With monoclonal antibodies, the phenotype is OKT3+, OKT4- and OKT8+, theoretically corresponding to the suppressor/cytotoxic T lymphocyte subset, but functionally the cells demonstrate killer cell (responsible for ADCC), but not natural or suppressor cell activity. (ii) another clinical variant with an aggressive course, massive hepato-splenomegaly, lymph node enlargement and very high lymphocyte counts; the lymphocytes are small without cytoplasmic granules; their immunological and functional characteristics have not been determined, but morphologically the cells correspond to the T helper/inducer lymphocyte subset. Thus, involvement of different T lymphocyte subsets may be the reason for the clinical variation in T CLL.

Aged↗
PubMed1983

Abnormal growth of ovarian antral follicles in breast cancer patients.

Ovarian antral follicles from patients with breast cancer were compared with follicles from healthy women. Steroid levels in the follicular fluid and the health status of the follicles were evaluated. Follicles were judged to be healthy or atretic by flow cytometric determinations of the deoxyribonucleic acid content of aspirated granulosa cell nuclei. Fifteen of the 25 follicles (60%) from the cancer patients contained unmeasurable or abnormally low steriod levels (i.e., less than 100 ng/ml) which were significantly (P less than 0.001) lower than in follicles of the same health status from healthy women (500 to 1000 ng/ml). It is speculated whether substances other than the usual follicular steriods are produced by the cancer patients, which stimulate mitotic activity of the granulosa cells.

Adult↗
PubMed1982

Flow sorting of mouse pancreatic B cells by forward and orthogonal light scattering.

Mouse islet cell suspensions were separated into subpopulations based on forward low angle and orthogonal scattered light. Separation fractions were analyzed for hormone content by radioimmunoassays. The pancreatic B-cells had the highest orthogonal light scattering, while they overlapped in forward low angle light scattering with other endocrine (glucagon, pancreatic polypeptide and somatostatin containing cells) and nonendocrine cells. Living and paraformaldehyde fixed islet cell suspensions showed similar distributions of combined light scattering.

Animals↗
PubMed1982

Flow cytometric deoxyribonucleic acid analysis of granulosa cells aspirated from human ovarian follicles. A new method to distinguish healthy and atretic ovarian follicles.

Granulosa cell aspirates from human ovarian follicles were analyzed by flow cytometry to determine the fraction of cells in the DNA S-phase of the mitotic cell cycle. The aim of the study was to evaluate if the percentage of granulosa cells in S-phase (the S-fraction) could be used to indicate whether a follicle was healthy or atretic. A highly significant relationship was found between the S-fraction and the concentration of estradiol in the follicular fluid (r = 0.6, P less than 0.001). More than 85% of the follicles having an S-fraction of 16% or greater contained intrafollicular levels of estradiol equal to or greater than 200 ng/ml and had a low androstenedione:estradiol ratio. Conversely, 95% or more of the follicles that had an S-fraction of less than 16% contained low estradiol (less than 200 ng/ml) and had a high androstenedione to estradiol ratio. We conclude that flow cytometric DNA measurements on follicular aspirates provide a reliable and rapid method by which to distinguish healthy and atretic ovarian follicles. Since only a small fraction (less than 5%) of an entire granulosa cell population is required for S-phase analysis, the technique allows the majority of cells to be immediately available or other biochemical studies. Moreover, since excision of ovarian tissue is avoided, the technique may be acceptable for studies on women with normal ovarian function but who are undergoing laparotomy or laparoscopy for some reason.

Adolescent↗
PubMed1980

Long-term treatment of depression with isocarboxazide.

Isocarboxazide has been used as long-term treatment for a selected group of 20 depressive patients, of whom some 90% (17/19) were non-responders to treatment with tricyclic antidepressants. At the follow-up the median duration of illness was 162 months, and the median duration of treatment was 42 months. Side-effects and interactions were moderate thus legitimating a treatment procedure on which all the patients of the material responded better than on any other antidepressive treatment. Treatment with monoamine-oxidase-inhibitors, like isocarboxazide, should not be left untried in the case of therapy-resistant depression.

Adult↗
PubMed1979

DNA flow cytometry of isolated keratinized epithelia: a methodological study based on ultrasonic tissue disaggregation.

Ultrasonication of keratinized, stratified, squamous epithelium, which had been separated from underlying tissue by means of acetic acid, resulted in disaggregation of all cellular layers in the epithelium, giving a suspension of single nuclei with mitoses preserved. This suspension was treated with RNAse and ethidium bromide for analysis by flow cytometry. From the resulting DNA histogram the G1, S and G2 + M fractions were estimated using the computer program of Fried (1976). Treatment with dithiothreitol before sonication increased the yield of nuclei in suspension and decreased the amount of debris and clumps, thereby suppressing overestimation of small S fractions. This method of preparation prior to DNA flow cytometry was useful for the study of the hamster cheek pouch epithelium and of normal and pathological human epidermis.

Animals↗
PubMed1979

Psychoses in drug-resistant temporal lobe epilepsy.

In the survey of 74 Danish patients with temporal lobe epilepsy who underwent temporal lobectomy, a total of 20 patients were psychotic. Nine of these became psychotic during the follow-up period, six of them after cessation of their epileptic seizures. There were 13 schizophrenia-like psychoses, six paranoid delusional and depressive psychoses, and one childhood psychosis. Operation was on the right side in 39 and on the left side in 35 patients. When the various psychotic groups were compared with each other or with the nonpsychotic patients, the side of operation was not found to be statistically important. The patients with psychoses were older at operation and showed a higher rate of focal lesions in the resected specimens. Although more psychotic patients were bright or normally gifted, and had achieved a higher standard of schooling than nonpsychotic patients, their social status after operation was inferior. Surgery had no effect on psychosis present preoperatively nor on its possible postoperative onset. The diagnosis of psychosis was not considered to be contraindication to temporal lobectomy.

Age Factors↗
PubMed1979

Mental aspects of temporal lobe epilepsy. Follow-up of 74 patients after resection of a temporal lobe.

Psychiatric disorders were investigated in 74 patients with drug-resistant temporal lobe epilepsy (complex partial epilepsy). In all cases unilateral anterior temporal lobectomy had been performed during the period 1960-69. At follow-up in 1970-71, 45 patients were free from seizures, and in a further group of 15 patients seizure frequency had been substantially reduced. There were four postoperative deaths. Six patients were psychiatrically normal and had no history of any such disorder. Behavioural disturbances were observed in 55 patients. Before operation 11 patients displayed schizophrenia-like psychoses, and nine others became psychotic during follow-up. Fourteen patients attempted suicide on one or more occasions. Half the patients had diminished sexual drive. Improvement in psychiatric status was clearly correlated with relief from seizures and, in those cases with only a few or no seizures after operation, led directly to social rehabilitation. The presence or absence of a psychiatric disorder was not useful as a criterion for or against surgery.

Adolescent↗
PubMed1979

Flowcytometric evaluation of the DNA distribution in isolated pancreatic islets from normal and diabetic mice.

Pancreatic islets from C57BL/KsJ-db/db, and +/+ mice were isolated by collagenase. After isolation the islets were transferred to a hypotonic ethidiumbromide solution with 0.3% of the detergent Nonidet P40. After vortexing, the samples were analyzed in a BioPhysics Cytofluorograf 4802A. The DNA histograms were divided into 2c, 2-4c, 4c and 8c fractions under the assumption of a constant rate of DNA synthesis during the 2-4c phase. In comparison with normal mice, we found that diabetic mice had a lower fraction of 2c nuclei and a higher fraction of 2-4c, 4c, and 8c nuclei. These results obtained by flow cytometry are in agreement with results obtained by 3HTdR incorporation and by cytophotometry on histological sections.

Animals↗
PubMed1979

Cell proliferation in normal and diseased gastric mucosa. Autoradiography after in vitro continuous labelling with tritiated thymidine.

The rate of gastric epithelial cell proliferation was studied in healthy volunteers and in patients with different degrees of gastritis. Endoscopic biopsies from the antral and fundic part of the stomach were incubated in vitro with 3H-thymidine for 30, 120, and 210 minutes respectively. Autoradiographs were prepared, and the percentage of DNA-synthesizing cells (labeling index) in the progenitor cell region was estimated. From the successive labeling indices the rate of entry of cells into DNA-synthetic phase (S-phase) and the duration of the S-phase could be estimated. All the biopsies were classified according to the degree of gastritis. The mean (+/-SEM) length of the S-phase was found to be 7.4 +/- 0.3 hours in antral mucosa and 7.2 +/- 0.4 hours in fundic mucosa. There was no significant difference between the S-phase duration in normal mucosa, superficial gastritis, mild atrophic gastritis and severe atrophic gastritis. This observation suggests that the labeling index can be used as an expression for the rate of cell proliferation in human gastric mucosa. A significant correlation between the labelling indices and the degree of gastritis was found in both antral and fundic mucosa. In six cases, labelling indices estimated by cell counts performed on longitudinal or cross sections of foveolae were compared. Ther was no significant difference between the results obtained by the two different counting techniques.

Adult↗
PubMed1978

The circadian variations in the epithelial growth of the hamster cheek pouch: quantitative analysis of DNA distributions.

The pronounced diurnal rhythm in DNA distributions of the hamster cheek pouch epithelium both in the S fraction and in the (G2 + M) fraction was compared with previous studies of the changes in tritiated thymidine labelling index and mitotic activity. The DNA distributions were obtained by flow cytometry after ultrasonic disaggregation of the isolated epithelium into a suspension of single nuclei. The DNA distributions were analysed with the computer program of J. Fried (1976) and by planimetry. The S fraction was higher than the autoradiographic labelling index during the whole 24 hr period. Only the computer fitted S fraction and the labelling index had the same difference between maximal and minimal values, and maxima at the same time of day. The DNA distributions showed a diurnal release of G1 cells into S phase proceeding through (G2 + M) phase and returning to G1 phase within a 24 hr period.

Animals↗