[Confidentiality--regulations and intuition. Interview by Kirsten Bjørnsson].
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Confidentiality↗
Biomedical subjects
L Nielsen
Publications and source records attributed to L Nielsen.
Morphological and functional characteristics of peritoneal mast cells from young rats.
To study why neonatal and young rats are resistant to the effects of some secretagogues, such as compound 48/80 and 2.5-S nerve growth factor, we examined peritoneal mast cells from 14-15-day-old rats (young rats) and compared them to peritoneal mast cells from adults. Peritoneal mast cells from young rats contain approximately one-tenth of the amount of histamine observed in adult peritoneal mast cells. However, both cell populations contained similar low levels of the mucosal mast cell-associated protease rat mast cell protease II. Histochemical analysis of peritoneal mast cells from young rats using safranin O and berberine sulphate suggested that only a portion of the granules of these cells contained heparin. At an ultrastructural level the young rat peritoneal mast cell contains relatively few granules. The majority of mast cells from young rats have a bilobed or indented nucleus which is only rarely observed in adult cells. Functionally, the young rat peritoneal mast cell demonstrates a significantly reduced histamine release in response to the connective tissue mast cell-specific secretagogues compound 48/80 and 2.5-S nerve growth factor. In contrast, the percent histamine release in response to the neurotransmitter substance P, which degranulates both connective tissue mast cells and intestinal mucosal mast cells, was similar in the adult cells and the young rat cells. This study demonstrates substantial differences between the young rat and adult peritoneal mast cells which may explain the ability of very young animals to withstand large doses of certain secretagogues.
Animals↗
Long-term followup of orthodontic treatment of a patient with maxillary protrusion, severe deep overbite and thumb-sucking.
Oral habits should be of primary clinical concern to orthodontists because they may cause malocclusion, and/or interfere with treatment progress. Generally habit control should be achieved prior to correction of the malocclusion in an effort to remove any etiological factors in development and maintenance of the malocclusion. It is also important for the clinician to understand that habit-breaking treatment may require an extended treatment time because habits may have been present for long periods of time and may be related to underlying psychological problems. The present report documents the treatment of maxillary protrusion in a patient in which a thumb-sucking habit had persisted from infancy until almost age 12. Elimination of the habit was accomplished prior to correcting the malocclusion and for stability of the result. Orthodontic treatment consisted of extracting two maxillary premolars followed by full treatment with fixed appliances. Long-term postretention records show good stability of the corrected malocclusion.
Child↗
Efficacy of acrivastine in the treatment of allergic rhinitis during natural pollen exposure: onset of action.
In a placebo-controlled, randomized, and double-blind 1-day field study, the efficacy and onset of action of capsule acrivastine 8 mg were evaluated in 42 patients suffering from allergic rhinoconjunctivitis elicited by natural grass pollen exposure. Before and for 2 h after treatment, the patients scored the severity of five rhinoconjunctivitis symptoms every 10 min on a 0-5 scale (0 = no symptoms; 5 = very severe symptoms). The number of sneezes was recorded, and every 30 min, measurements of nasal peak flow were made. Before treatment, there was no difference in median total symptom score (mTSS) between the acrivastine group (A) and the placebo group (P) (12 and 12, respectively). Time of onset was estimated by an exponential decay model to be 19 min (95% confidence interval 0-39 min). A statistically significant difference in percent reduction of mTSS between A and P was observed for the first time 46 min after treatment start (A = 22%, P = 0%, P < 0.05). A 50% reduction in total symptom score (TSS) was achieved within 60 min by 38% in A and 17% in P (NS), and within 80 min in 52% and 17%, respectively (P < 0.05). The median time for 50% reduction in TSS (MT50) was 80 min for A and > 120 min for P (P < 0.01). The symptom score of sneezing and number of sneezes were evaluated for periods of 30 min. The difference between A and P became statistically significant from 31-60 and 61-90 min, respectively (P < 0.05 and P < 0.01). Objective and subjective determinants in the different time intervals were well correlated. Improvement of nasal congestion was observed in A at 91-120 min, as measured by nasal peak flow.
Administration, Oral↗
Tumour necrosis factor and eicosanoid production from monocytes exposed to HIV in vitro.
We investigated the hypothesis that exposure of monocytes to human immunodeficiency virus (HIV) augments production of proinflammatory mediators. The production of tumour necrosis factor alpha (TNF-alpha) and the eicosanoids PGE2 and LTB4 from human monocytes was evaluated after exposure to two strains of HIV (SSI-002 or HIV-1IIIB). After 16 h incubation with low doses of SSI-002, lipopolysaccharide-stimulated TNF-alpha production was enhanced 70-85% while PGE2 production was decreased. Heat-inactivated virus failed to alter the production of these mediators. Higher viral doses tended to decrease TNF-alpha and PGE2 production concomitantly, but this might be due to toxicity. HIV-1IIIB had no effect on either TNF-alpha or PGE2 production. Calcium ionophore-stimulated LTB4 production was doubled by HIV-1IIIB, but significantly decreased by SSI-002. Three or seven days after exposure to both HIV strains, increased PGE2 production was found. In conclusion, HIV only modestly altered the production of mediators from monocytes. The effects were strain-specific. In most experiments a second stimulus was required to demonstrate differences.
Dinoprostone↗
Chronic fatigue syndrome--a controlled cross sectional study.
OBJECTIVE: To look for signs of immunodeficiencies and/or longstanding infections underlying chronic fatigue syndrome (CFS). METHODS: Twenty-one patients fulfilling the Centers for Disease Control criteria for CFS were compared to 21 age and sex matched controls. A number of viral antibodies as well as the following tests evaluating the immune system were studied: autoantibody profile, cell surface markers on isolated blood mononuclear cells, cytokine production, lymphocyte proliferative responses, natural killer cell activity and quantitation of immunoglobulin secreting cells. RESULTS: Production in vitro of the predominantly T cell derived cytokines interleukin 2 and interferon gamma was significantly higher in patients with CFS compared to the control group. Furthermore, the serum concentrations of IgA and IgE were lower in patients with CFS; however, this difference was caused by a larger number with values of IgA and IgE above the upper limit of the normal range among the controls than among the patients with CFS. All other variables were similar in the 2 groups. CONCLUSION: A pathogenically significant imbalance of the immune system in patients with CFS cannot be excluded. However, evidence of a causal link between abnormal immunity and CFS was not obtained.
Adolescent↗
Leukemia inhibitory factor production by rat mast cells.
Leukemia inhibitory factor (LIF) is a pluripotent cytokine of importance in the regulation of immune and inflammatory responses. This cytokine may play an important role in neuronal development and bone metabolism. We have examined the ability of freshly isolated rat mast cells and mast cell lines to produce LIF at both the mRNA and bioactivity levels. Initial experiments demonstrated that two mucosal mast cell-like cell lines RBL.2H3 and RCMC9 endogenously produced low levels of LIF bioactivity. The production of this cytokine was examined using a hepatocyte-stimulating factor activity assay and confirmed by the use of neutralizing antibodies specific for LIF. This production was enhanced by treatment with the calcium ionophore A23187. No interleukin-6 production was observed by these cells either endogenously or following ionophore activation. Freshly isolated highly purified rat peritoneal mast cells also expressed mRNA for LIF. These results could have important implications for the role of mast cells in neuronal development, hematopoiesis bone metabolism and the acute-phase response.
Animals↗
Complex telomere-associated repeat units in members of the genus Chironomus evolve from sequences similar to simple telomeric repeats.
The dipteran Chironomus tentans has complex tandemly repeated 350-bp DNA sequences at or near the chromosome ends. As in Drosophila melanogaster, short simple repeats with cytosines and guanines in different strands have never been observed. We were therefore interested in learning whether the Chironomus repeats could have evolved from simple sequence telomeric DNA, which might suggest that they constitute a functional equivalent. We screened for repeat units with evolutionarily ancient features within the tandem arrays and recovered two clones with a less-evolved structure. Sequence analysis reveals that the present-day 350-bp unit probably evolved from a simpler 165-bp unit through the acquisition of transposed sequences. The 165-bp unit contains DNA with a highly biased distribution of cytosine and guanine between the two strands, although with the ratios inverted in two minor parts of the repeat. It is largely built up of short degenerate subrepeats for which most of the sequence can be reconstructed. The consensus for the subrepeat sequence is similar to the simple telomeric repeat sequences of several kinds of eukaryotes. We propose that the present-day unit has evolved from telomeric, simple sequence, asymmetric DNA from which it has retained some original sequence features and possibly functions.
Animals↗
[Nicaragua--from knowledge to action].
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Denmark↗
Modelling the growth and protein production by insect cells following infection by a recombinant baculovirus in suspension culture.
A mathematical model has been developed to describe the growth and infection of insect cells by recombinant baculoviruses. The model parameters were determined from a series of independent experiments involving batch suspension culture. The profiles generated by the model for cell growth, virus production and protein production agree with those observed in experiments. Presently, the model simulates only systems where cells are not growth-limited. The model is useful in aiding the design and optimization of large-scale systems for production of biological insecticides as well as recombinant proteins and in delineating those areas which are limiting the process and require further, more fundamental, investigation.
Animals↗
Muscarinic cholinergic agonists and antagonists of the 3-(3-alkyl-1,2,4-oxadiazol-5-yl)-1,2,5,6-tetrahydropyridine type. Synthesis and structure-activity relationships.
A series of 3-(3-alkyl-1,2,4-oxadiazol-5-yl)-1,2,5,6-tetrahydro-1-methylpyr idines (2a-q) were synthesized and tested for central muscarinic cholinergic receptor binding affinity by using [3H]oxotremorine-M and [3H]QNB as ligands and in a functional assay using guinea pig ileum. The analogues with unbranched C1-8-alkyl substituents (2a-g) were agonists, whereas the compounds with branched or cyclic substituents (2h-m) were antagonists. The alkyl ether analogues (2o-q) were also agonists but had lower receptor binding affinity than the corresponding alkyl analogues. The 3-(5-alkyl-1,2,4-oxadiazol-3-yl)-1,2,5,6-tetrahydro-1-methylpyridi ne analogues had only ver low affinity for the central muscarinic receptors and were weak antagonists in the ileum assay. A few 3-(3-butyl-1,2,4-oxadiazol-5-yl)-1,2,5,6-tetrahydro-1-methylpyr idines substituted with methyl or hydrogen in the 1-, 5-, or 6-position were synthesized and tested. N-Desmethyl analogue 7 was a potent muscarinic agonist, whereas N-desmethyl-5-methyl analogue 11 and N-methyl-6-methyl analogue 13 both were antagonists with lower muscarinic receptor affinity. The 3-(3-butyl-1,2,4-oxadiazol-5-yl)quinuclidine (17) and tropane (15) analogues were both very potent antagonists with high affinity for central muscarinic receptors. The ratio [IC50(QNB)/IC50(Oxo-M)] x 0.162 proved to be a good indicator of the efficacy of the compounds in the guinea pig ileum assay.
Animals↗
Occlusal contacts in maximum intercuspation and craniomandibular dysfunction in 16- to 17-year-old adolescents.
The relationship between number, distribution and intensity of occlusal tooth contacts and the craniomandibular functional status was investigated in 56 subjects aged 16-17 years. The photocclusion technique was used for the qualitative and quantitative evaluation of occlusal contacts, and a clinical examination was performed to assess the function of the stomatognathic system. According to a matched-pairs design two groups were formed, one consisting of individuals with signs of craniomandibular disorders, and the other consisting of functionally healthy adolescents. The pairs were matched according to morphological occlusal characteristics. The results of the present study emphasize the importance of occlusal contacts in relation to craniomandibular function. In particular the posterior occlusion appeared to be related to function, since statistically significant differences between the two groups were detected with regard to the number and load of contacts. Symmetry of intensity rather than symmetry of contact distribution per se seemed to be important in relation to craniomandibular function.
Adolescent↗
Subrepeats result from regional DNA sequence conservation in tandem repeats in Chironomus telomeres.
Repeat units, widespread in eukaryotic genomes, are often partially or entirely built up of subrepeats. Homogenization between whole repeat units arranged in tandem usually can best be understood as a result of unequal crossing over. Such a mechanism is less plausible for maintaining similarities between subrepeats within a repeat unit when present in a regular array. In Chironomus telomeres, large blocks of tandemly repeated approximately 350 base-pair units contain two or three pairs of subrepeats with high mutual identities, embedded in linker DNA, non-repetitive within the repeat unit. Measurements of evolutionary base changes in two closely related species, Chironomus tentans and Chironomus pallidivittatus, permit us to conclude that the subrepeat arrangement is best explained as a consequence of regional sequence conservation after an earlier duplication of an ancestral half-unit.
Animals↗
[Women and AIDS. It could have been you. Interview by Kirsten Bjørnsson].
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Acquired Immunodeficiency Syndrome↗
[Regional fibrinolysis with tissue plasminogen activator (rt-PA) (Actilyse)].
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Fibrinolysis↗
[Living conditions and social needs of long-term psychiatric patients].
The purposes of this case-referent study were to investigate psychiatric long-term patients' social living conditions compared with these of the background population, their need of social support and to find a possible connection between these conditions and the patients' utilization of care. Our cases were 85 psychiatric long-term patients in Psychiatric Department, Horsens Sygehus, Denmark, interviewed in autumn 1987. Our control group was the population in the catchment area of the department. The distribution of social living conditions in the control group is estimated by a cross-section sample, interviewed as part of the welfare survey of 1986. Psychiatric long-term patients belonged to lower social classes and had lower family-gross-income (p = 0.008, p = 0.009, respectively). They suffered more frequently from nervous complaints (p less than 0.0001). 84% lacked close social contacts and/or lacked influence compared with 47% in the total population (p less than 0.00001). 57% of the patients appeared to need at least one kind of social support. The patients who appeared to be in need of four various kinds of support used the treatment facilities more often than the rest of the patients (p = 0.02) and so did the patients with health problems or those whose close social contacts were deficient and/or lacked influence (p less than 0.05).
Adolescent↗
The role of mast cell degranulation products in mast cell hyperplasia. I. Mechanism of action of nerve growth factor.
A variety of mast cell degranulating agents have previously been shown to induce mast cell hyperplasia in adult rats. In neonates 2.5 S nerve growth factor (NGF) induces a hyperplasia of both mucosal and connective tissue mast cells (MMC and CTMC). We have examined the role of the potent mast cell degranulating properties of NGF on its ability to induce mast cell hyperplasia. Administration of NGF in combination with the mast cell stabilizing agent disodium cromoglycate was found to abrogate the CTMC hyperplasia induced by NGF alone. Treatment of neonatal rats with the alternate degranulating agent compound 48/80 was found to induce a limited CTMC but not a MMC hyperplasia. A supernatant obtained by degranulating purified adult rat peritoneal mast cells with anti-IgE was found to induce hyperplasia of the CTMC population similar to that observed with NGF administration. However, this degranulation product supernatant only induced a limited MMC hyperplasia as judged by RMCP II content of the tissues. These results suggest that NGF has dual action inducing mast cell hyperplasia; CTMC hyperplasia being dependent on the ability of NGF to degranulate mast cells. MMC hyperplasia induced by NGF is independent of CTMC degranulation. Degranulation products from peritoneal mast cells act to increase both MMC and CTMC populations in the neonate. These data suggest that the CTMC population may be regulated by an autocrine positive feedback mechanism in vivo.
Animals↗
[Respiratory arrest following retrobulbar block].
After a retrobulbar block, a patient developed transient apnoea and cranial nerve paralysis. All of the symptoms resolved within hours. According to the literature, apnoea is a rare complication of retrobulbar blockade and usually develops ten minutes after administration of the blockade at the latest. The outcome is excellent if skilled staff, and facilities for resuscitation are available. This complication does not occur after peribulbar anaesthesia.
Apnea↗