Search PubMed⌕ Search

Biomedical subjects

J K Larsen

Publications and source records attributed to J K Larsen.

At least 37 records · Page 2Linked to original sources
PubMed1998

Immediate bromodeoxyuridine labelling of unseparated human bone marrow cells ex vivo is superior to labelling after routine laboratory processing.

It is important to evaluate the proliferation of bone marrow cells in several disease conditions and during treatment of patients with for example cytokines. Labelling with bromodeoxyuridine (BrdUrd), immunocytochemical staining with anti-BrdUrd antibody and analysis by flow cytometry provides a reliable and reproducible technique for estimation of the fraction of cells that incorporated BrdUrd into DNA during S-phase. We have compared immediate BrdUrd labelling of unseparated bone marrow cells with the previously used labelling in the laboratory after routine separation of the mononuclear cells. Bone marrow aspirates from seven lymphoma patients without bone marrow involvement were studied with these two methods. We found higher BrdUrd labelling indices (LI) in the mononuclear cells, when cells were labelled immediately. A large variation in LI was found between patients. Our results suggest that ex vivo BrdUrd labelling of bone marrow cells should be performed immediately after aspiration and before separation, because these data are closer to values reported from in vivo labelling with BrdUrd.

Bone Marrow Cells↗
PubMed1997

The Major Depression Rating Scale (MDS). Inter-rater reliability and validity across different settings in randomized moclobemide trials. Danish University Antidepressant Group.

The Major Depression Rating Scale (MDS) has been derived from the Hamilton Depression Scale and the Melancholia Scale. The MDS contains the nine DSM-IV items for major depression which all have anchoring scores from 0 to 4; hence, the theoretical score range is up to 36. The Major Depression Rating Scale has in this study been psychometrically analysed in randomized moclobemide trials. The results showed that the MDS had higher internal validity than the Hamilton Depression Scale. Thus, the homogeneity of the items was higher; factor analysis identified only one general depression factor (after 4 weeks of treatment explaining more than 50% of the variance). The inter-rater reliability of the two scales was of the same high level. The ability to measure changes (external validity) was tested in randomized clinical trials with moclobemide versus tricyclics (clomipramine and notriptyline) performed in Denmark in the psychiatric setting as well as in the general practice. The results showed that in the psychiatric setting tricyclics were superior to moclobemide with effect sizes ranging between 0.43 and 0.53. The highest effect size was obtained with the Melancholia Scale and the Major Depression Rating Scale, while the Hamilton Depression Scale was below 0.50. In the general practice setting no difference was found between moclobemide and clomipramine. In conclusion, the Major Depression Rating Scale has been found to have a more homogeneous factor structure than the Hamilton Depression Scale, but still with the same level of reliability and external validity. However, studies are needed to standardize the scale, especially in the general practice setting.

Antidepressive Agents↗
PubMed1997

Phosphorylation of the 27-kDa heat shock protein via p38 MAP kinase and MAPKAP kinase in smooth muscle.

The 27-kDa heat shock protein (HSP27) is expressed in a variety of tissues in the absence of stress and is thought to regulate actin filament dynamics, possibly by a phosphorylation/dephosphorylation mechanism. HSP27 has also been suggested to be involved in contraction of intestinal smooth muscle. We have investigated phosphorylation of HSP27 in airway smooth muscle in response to the muscarinic agonist carbachol. Carbachol increased 32P incorporation into canine tracheal HSP27 and induced a shift in the distribution of charge isoforms on two-dimensional gels to more acidic, phosphorylated forms. The canine HSP27 amino acid sequence includes three serine residues corresponding to sites in human HSP27 known to be phosphorylated by mitogen-activated protein kinase-activated protein (MAPKAP) kinase-2. To determine whether muscarinic receptors are coupled to a "stress response" pathway in smooth muscle culminating in phosphorylation of HSP27, we assayed MAPKAP kinase-2 activity and tyrosine phosphorylation of p38 mitogen-activated protein (MAP) kinase, the enzyme thought to activate MAPKAP kinase-2. Recombinant canine HSP27 expressed in Escherichia coli was a substrate for MAPKAP kinase-2 in vitro as well as a substrate for endogenous smooth muscle HSP27 kinase, which was activated by carbachol. Carbachol also increased tyrosine phosphorylation of p38 MAP kinase. SB-203580, an inhibitor of p38 MAP kinases, reduced activation of endogenous HSP27 kinase activity and blocked the shift in HSP27 charge isoforms to acidic forms. We suggest that HSP27 in airway smooth muscle, in addition to being a stress response protein, is phosphorylated by a receptor-initiated signaling cascade involving muscarinic receptors, tyrosine phosphorylation of p38 MAP kinase, and activation of MAPKAP kinase-2.

Amino Acid Sequence↗
PubMed1997

Lesional psoriatic T cells contain the capacity to induce a T cell activation molecule CDw60 on normal keratinocytes.

In this report we demonstrate, that in psoriatic skin, basal and suprabasal keratinocytes express CDw60. The CDw60-specific monoclonal antibody, UM4D4, has recently been shown to recognize the 9-O-acetylated disialosyl group on ganglioside GD3. The CDw60 antigen on cultured keratinocytes also seems to be identical with the 9-O-acetylated disialosyl group, because the anti-UM4D4 binding was markedly reduced after neuraminidase treatment of keratinocytes. To examine whether factors from T cells in psoriatic lesions are responsible for the overexpression of CDw60 on keratinocytes, T cell lines obtained from lesional skin were initiated and cloned by limiting dilution. Factors released from 19 of 19 activated T cell clones up-regulated CDw60 expression on cultured normal keratinocytes. T-cell-secreted cytokines, including interleukin (IL)-2, IL-3, IL-4, IL-6, IL-13, transforming growth factor-beta, granulocyte/macrophage colony-stimulating factor, and interferon-gamma were tested for their capacity to modulate keratinocyte CDw60 expression. IL-4 and IL-13 strongly up-regulated the expression of CDw60; by contrast, interferon-gamma down-regulated keratinocyte CDw60 expression. Interestingly, IL-13 may in part be responsible for the T-cell-induced up-regulation of CDw60, because anti-IL-13 partly neutralized this effect of the T cell supernatant. In conclusion, CDw60 expression on psoriatic epidermal keratinocytes is likely induced by intralesionally activated T cells and may in part be due to IL-13. These findings would represent a novel mechanism by which T cells participate in the pathogenesis of psoriasis.

Antibodies↗
PubMed1997

DNA ploidy analysis in breast carcinoma. Comparison of unfixed and fixed tissue analyzed by image and flow cytometry.

OBJECTIVE: To form a methodologic basis for DNA analysis of ductal carcinoma in situ (DCIS) and invasive carcinoma (IC) of the breast, including very small lesions, by comparison of flow cytometric (FCM) and image cytometric (ICM) methods for DNA quantitation. STUDY DESIGN: The material consisted of 41 DCIS lesions and 26 ICs. FCM DNA analysis of unfixed, frozen samples were compared to (1) FCM of formalin-fixed, paraffin-embedded tissue; (2) ICM of imprints; and (3) ICM of paraffin-embedded tissue sections. RESULTS: FCM of unfixed tissue showed higher DNA measurement precision and a higher number of DNA nondiploid clones as compared to the other three methods. For the classification of DNA diploid/nondiploid cases, high concordance rates were found between the methods. Discordant cases were predominantly DNA neardiploid by FCM of unfixed tissue but DNA diploid by the other methods. The reproducibility of the DNA index (DI) was best in the interval 1.2 < DI < or = 2.2; it was 74% for FCM of fixed tissue and 79% for ICM of imprints. Clones with DI > 3 were found almost exclusively by ICM of imprints. For ICM of tissue sections, DI could not be reliably estimated. By ICM, contrary to FCM, a combined DNA diploid and nondiploid pattern was found frequently. CONCLUSION: Each of the methods has its own advantages and limitations. If possible, FCM should be combined with ICM. FCM of unfixed tissue is superior to the other methods with respect to precise DI estimation. Alternatively, FCM of fixed tissue and ICM of imprints may both give a reliable estimate of DI. ICM of tissue sections can discriminate DNA diploid from nondiploid clones, except for neardiploid subpopulations, and permits the analysis of very small lesions.

Breast Neoplasms↗
PubMed1996

[Angiotensin-converting enzyme inhibitors and anesthesia].

The increasing usage of ACE-inhibitors in the treatment of hypertension and chronic heart failure may increase the incidence of adverse anaesthetic occurrences. Four such cases are described. In two of these cases, the patient reacted with severe hypotension when general anaesthesia was supplemented with epidural bupivacaine. Another patient suffered a heart fatality after severe hypotension in conjunction with the administration of a spinal anaesthetic. Finally, one patient suffered sudden fatal pulmonary oedema after completion of uneventful general anaesthesia, possibly due to late resumption of ACEI-treatment. The cases are discussed in detail, with particular reference to the possible underlying mechanisms. Preoperative discontinuation of ACEI-treatment is controversial. We present some of the issues involved. Most authors lean towards continuing ongoing treatment, even though there is firm evidence that this increases the risk of hypotensive episodes due to hypovolaemia, arguing that such events may be predicted and antagonized with fluid therapy.

Aged↗
PubMed1996

Tissue disaggregation for flow cytometric DNA analysis: comparison of fine-needle aspiration and an automated mechanical procedure.

Flow cytometric DNA analysis was performed on unfixed frozen samples from 56 breast cancer patients. From each patient, two samples were analyzed. The only difference in the handling of the paired samples was the mechanical disaggregation of one sample by fine-needle aspiration compared to an automated mechanical disaggregation method (Medimachine) of the other sample. With the two methods for tissue disaggregation, the same resolution of the DNA histograms was obtained, indicated by median coefficients of variation (CV) of 1.5% for the DNA diploid G1 peaks. Also, the frequencies of DNA diploid and aneuploid cases as well as the fractions of DNA aneuploid cells were comparable. This indicates that the two methods did not differ in ability to detect DNA aneuploid tumor clones. Automated mechanical disaggregation resulted in DNA histograms with significantly less debris and with lower S-phase fractions. In practice, the procedure of automated mechanical disaggregation was rapid, easy, and safer because of minimal handling of the unfixed tissue compared to the fine-needle aspiration.

Automation↗
PubMed1996

[Abnormal neurological findings at first admission in patients with schizophrenia or schizophreniform disorders. Results of computer tomography and measurement of regional cerebral blood flow].

Forty-five patients with schizophrenia or schizophreniform disorder admitted to hospital for the first time had a neurological examination, including integrative sensory and complex motor acts, by a trained neurologist. The patients were studied by CT and regional cerebral blood flow as well. A control group of 24 healthy volunteers was included. The patients had significantly more neurological abnormalities (NA) than the healthy volunteers. Medication did not explain the discrepancy. The NA were associated with sulcal enlargement and smaller brains as visualized by CT but not with ventricular enlargement. There was no association between the regional flow values and NA.

Adolescent↗
PubMed1996

The bone-marrow infiltration pattern in B-cell chronic lymphocytic leukemia is not an important prognostic factor. Danish CLL Study Group.

In a multicentre study of 635 consecutive newly diagnosed patients with B-CLL, the histological bone marrow (BM) specimens were reviewed independently by each of 3 pathologists and found evaluable for BM infiltration pattern in 575 patients, 404 of whom had a CD5+, mainly FMC7-, faint surface-membrane immunoglobulin (SIg) fluorescence-intensity ppenotype. In these 404 patients the following BM infiltration patterns were found: mixed nodular-interstitial (30%), moderate interstitial (44%), heavy interstitial (20%) and diffuse packed (6%). In univariate survival analysis, significant differences were found according to BM pattern (p < 0.05), the presence of nodules being a favorable prognostic sign. In multivariate survival analysis in a model including age, clinical stage, BM pattern, BM lymphocytosis, WBC and sex, only age and stage but not BM pattern or BM lymphocytosis had independent prognostic significance. In stage A, progression-free survival was significantly longer in patients with nodular than in patients with non-nodular bone-marrow pattern. The overall survival of these patients, however, did not differ, possibly owing to the prompt and prolonged treatment given to most patients at the time of progression to stage B or C. We conclude that in CD5+, SIg(faint), mainly FMC7-B-CLL, bone-marrow histology may predict unstable disease in early clinical stage but is not important for treatment decisions, when these are based on clinical stage.

Age Factors↗
PubMed1996

Circadian variation of DNA replication in hamster cheek pouch epithelium analysed by tritiated thymidine labelling, flow sorting and autoradiography: no resting S phase cells in the normal epithelium.

In the normal hamster cheek pouch epithelium, cell proliferation takes place with a pronounced circadian rhythm. We tested our previous hypothesis that all cells having S phase DNA content are actively synthesizing DNA and thus participating in the daily cohort of proliferating cells. We found no evidence of resting S phase cells in the normal epithelium. Using labelling with tritiated thymidine followed by fluorescence activated cell sorting according to DNA content and by autoradiography of the sorted nuclei, it was demonstrated that during the 24 h period almost all cells with mid S phase DNA content were active in DNA synthesis.

Animals↗
PubMed1995

DNA analysis of in situ ductal carcinoma of the breast via flow cytometry.

Flow cytometric (FCM) DNA analysis of 41 clinical cases of ductal carcinoma in situ (DCIS) of the breast was performed on fine-needle aspirates of unfixed, frozen tissue. Based on analysis of a single tissue sample, abnormal DNA content was found in 35 (85%) of the cases, and 15 (37%) disclosed heterogeneity. If five or more samples were analyzed, then heterogeneity was found in eight of ten cases. No conclusive correlation could be found between DNA index (DI) and histopathology. Our results on DCIS demonstrate a very high concordance with invasive breast cancer with respect to the frequency of DNA nondiploid cases, distribution of DI, occurrence of multiple clones, and S-phase fraction. This indicates that major genetic alterations and DNA heterogeneity are early events in carcinogenesis that are already established at the preinvasive stage.

Breast Neoplasms↗
PubMed1995

Cloning and sequencing of a cDNA encoding the canine HSP27 protein.

The nucleotide (nt) sequence encoding a 27-kDa heat-shock protein (HSP27) was determined from cDNAs cloned from a canine smooth muscle library. The primary structure deduced from the nt sequence reveals a 209-amino-acid protein having 86-89% identity with human, mouse, rat and hamster small HSP. Similar to human HSP27, the canine protein contains three Ser residues that are potential MAPKAP kinase II substrates.

Amino Acid Sequence↗
PubMed1995

DNA aneuploidy in early breast cancer.

High-resolution flow cytometric (FCM) DNA analysis was performed on 148 unfixed, frozen tissue samples from four groups of early breast cancers: invasive carcinomas (ICs) with predominance of carcinoma in situ (DCIS) (group I), small clinical cancers < or = 15 mm (group II), node-negative, clinical cancers (group III) and small screening-detected cancers < or = 15 mm (group IV). The median tumour size was 12 mm. The aim of the study was to support, with a larger sample, our recent findings with respect to DNA ploidy pattern in the selected group of ICs with predominance of DCIS (group I). Similar results to this group were found for both the small clinical cancers and the node-negative cancers, with respect to frequency of DNA aneuploidy (79% and 90%), DNA index (DI) distribution, intratumoral DNA heterogeneity and S-phase fraction. A high frequency of DNA hyperdiploid clones was found, in particular related to highly differentiated tumours. A significant difference was found compared with the screening-detected cancers, which were characterised by a much lower frequency of DNA aneuploid samples (49%) and may represent a biologically specific group of low-malignant, slowly growing tumours. Associations were shown between histological grade and DI subclasses, and between lymph node status and DNA diploidy/aneuploidy, whereas DI was not correlated with tumour size. The DNA ploidy findings in this series of early cancers are concordant to our own results from preinvasive lesions as well as those reported from series of more advanced cancers.

Adult↗
PubMed1995

Cell cycle perturbation by sodium butyrate in tumorigenic and non-tumorigenic human urothelial cell lines assessed by flow cytometric bromodeoxyuridine/DNA analysis.

The effect of sodium butyrate on cell proliferation was studied in eight human urothelial cell lines differing in transformation grade (TGr): Hu 1752 (mortal, TGr I); HCV29 (immortal and tumorigenic, TGr II); HCV29T, T24, T24A, T24B, Hu 961A and Hu 1703He (tumorigenic, TGr III). In all cell lines, except Hu 1752, addition of 4 mM sodium butyrate at 18 h after replating resulted in a significantly decreased population of adherent cells after a further 24-48 h. This might partially be explained by detachment of cells, probably mainly S phase cells, from the substrate in the lines HCV29, HCV 29T, Hu 961A and Hu 1703He. Flow cytometric DNA analysis of the adherent cell population showed that all TGr II and III urothelial cell lines were DNA aneuploid, and that butyrate perturbed the cell cycle distribution in these cell lines, mainly by a decrease of the S phase fraction. Flow cytometric bromodeoxyuridine (BrdUrd)/DNA analysis of continuously BrdUrd labelled cultures, using a 'washless' BrdUrd/DNA staining technique, showed that butyrate inhibited the G0/1-S phase transition, indicated by a delayed depletion of BrdUrd negative G0/1 cells in the cell lines HCV29, HCV29T, T24B, Hu 961A and Hu 1703He. BrdUrd/DNA analysis further showed that butyrate inhibited the G2M-G0/1 phase transition, indicated by a pronounced accumulation of BrdUrd positive G2M cells in the cell lines HCV 29T, T24B, Hu 961A and Hu 1703He. Microscopy of HCV29T and Hu 961A cells indicated that this block did not occur in mitosis. The parental cell line T24 and the cell line T24A did not show an accumulation of BrdUrd negative G0/1 cells or BrdUrd positive G2M cells like that occurring in the derived cell line T24B.

Amnion↗
PubMed1995

Effect of chronic and experimental jaw muscle pain on pain-pressure thresholds and stimulus-response curves.

Pain-pressure thresholds (PPTs) and stimulus-response (S-R) curves in masseter muscles and index fingers of 11 female patients with chronic jaw-muscle pain were compared with that of 11 matched control subjects. Experimental hyperalgesic and hypoalgesic conditions in the masseter muscles of control subjects were induced by intramuscular injection of 5% saline and of local anesthetic, respectively. The PPTs were found to be significantly lower in the masseter muscles of pain patients than in those of control subjects. The mean slopes of the S-R curves were significantly steeper for the masseter muscles of pain patients (0.481 +/- 0.213) than of control subjects (0.274 +/- 0.201, P < .0256). There were no statistically significant differences in PPTs or S-R curves for the index finger. The PPTs in masseter muscles of control subjects were not significantly affected by injection of 5% saline; however, the slopes of the S-R curves for the masseter muscles were significantly steeper for saline-injection values compared to baseline values (21.7% +/- 29.6%, P < .037). Injection of local anesthetic into masseter muscles of control subjects increased the PPTs significantly and reduced the slopes of the S-R curves significantly as compared to baseline values (-22.9% +/- 34.6%, P < .0155). The present results suggest that PPTs and S-R curves are valuable tools for quantitative description of chronic and experimental jaw muscle pain.

Adult↗
PubMed1995

Flow cytometric DNA analysis of breast cancers with predominance of carcinoma in situ: a comparison of the premalignant and malignant components.

Flow cytometric DNA analysis was performed on unfixed frozen tissue samples from 48 cases of invasive breast cancer (IC) with a predominance of ductal carcinoma in situ (DCIS). In 15 cases the samples contained only the DCIS component, in 17 cases only the IC component, whereas in 16 cases separate samples from the DCIS as well as the IC part within the individual lesion were available. In the latter 16 cases, complete or partial accordance in DNA ploidy between DCIS and IC was found in 12 cases, whereas no correspondence could be demonstrated in the remaining 4 cases, possibly due to intratumoral DNA heterogeneity. Comparison of the DNA index distribution in samples of DCIS and IC from the 48 cases showed concordant results except for the DNA hyperdiploid subclass, in which 6 clones were found in the DCIS portion compared to 18 clones in the IC portion. S-phase fractions were also comparable in the two groups. A comparison of the DCIS component from the present series of breast cancers to our previous series of pure DCIS also showed similar results with respect to the DNA index distribution, DNA heterogeneity, and S-phase fraction. No differences could be demonstrated between DCIS with and without invasion. The results indicate that the DNA ploidy pattern of breast cancer, as detected by flow cytometric DNA analysis, is established at the preinvasive stage of carcinogenesis.

Breast Neoplasms↗