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Biomedical subjects

D Hansen

Publications and source records attributed to D Hansen.

At least 73 records · Page 4Linked to original sources
PubMed1996

Intrauterine growth retardation and premature delivery: the influence of maternal smoking and psychosocial factors.

OBJECTIVES: This study investigated the influence of psychosocial stress, maternal schooling, social support, psychological well-being, alcohol, and smoking on intrauterine growth retardation and premature delivery. METHODS: At a Copenhagen university hospital, 2432 pregnant women completed a questionnaire on general health, psychosocial stressors, and sociodemographic characteristics. RESULTS: In 212 cases (8.7%) the women delivered prematurely. Preterm delivery as associated with psychosocial stress (adjusted odds ratio [OR]=1.14 for each 1-point increase on the psychosocial stressor 5-point scale and 1.92 for the whole scale) and poor school education (adjusted OR=2.62 for 7-9 years of schooling, 1.91 for 10 years, and 1.0 for 11-13 years). In 152 cases (6.3%), infants had a birthweight below the 10th percentile. Intrauterine growth retardation was associated with smoking, daily drinking, school education, and social network variables. In a multiple logistic regression model, intrauterine growth retardation was associated with smoking habits (adjusted OR=2.40 for 0-9 cigarettes daily, 2.68 for 10-15 daily, and 2.88 for more than 15 daily). CONCLUSIONS: Psychosocial stressors and limited duration of schooling appeared to influence preterm delivery. Smoking habits influenced intrauterine growth retardation.

Adult↗
PubMed1995

Regulation of Dictyostelium early development genes in signal transduction mutants.

The secreted cyclic nucleotide phosphodiesterase (PDE) and its glycoprotein inhibitor (PDI) are among the first genes expressed when Dictyostelium amoebae begin their development. We used a series of mutants with defects in signal transduction to ask whether cAMP receptors 1 and 3, G alpha2, G beta, adenylyl cyclase (ACA), or the protein kinase A catalytic subunit (PKAcat) are required for the initial appearance or later regulation of the PDE and the PDI transcripts. The PDE gene produces a 1.9-kb transcript during vegetative growth and then a 2.4-kb transcript during the early hours of development. Regulation of the 2.4-kb transcript in CAR1, G alpha2, G beta, and ACA mutants is similar to that of isogenic parental strains, although its level is reduced in strains that carry the CAR1 mutation. CAR1/CAR3 double mutants also produce less PDE transcript, but the PDE gene remains inducible by cAMP. The PKAcat mutant produces the 2.4-kb PDE transcript, but in this mutant the vegetative transcript is retained in development. CAR1 and CAR3 are not required for transcription of the PDI gene, but deleting CAR1 leads to overproduction of the PDI transcript. Induction or repression of the PDI gene does not require G alpha2, G beta, or ACA. PKAcat is required for synthesis of the PDI transcript. The results suggest a two-stage regulation of these early genes through a G alpha2/G beta-independent mechanism and an absolute dependence of PDI on the PKAcat.

Adenylyl Cyclases↗
PubMed1995

[Cerebral vasospasm following aneurysmal subarachnoid hemorrhage. Therapeutic value of treatment with calcium antagonists, hypervolemic hemodilution and induced arterial hypertension].

Only 53%-58% of patients with a subarachnoid haemorrhage (SAB) following the rupture of a cerebral aneurysm survive without neurological damage. Morbidity and mortality are closely related to the delayed ischaemic neurological deficit due to cerebral vasospasm. The following review gives an account of pathophysiological mechanisms; the importance of treatment with calcium antagonists, hypervolaemic haemodilution, and induced arterial hypertension is discussed in light of the current literature. PATHOPHYSIOLOGY. In addition to other vasoactive substances in the blood, haemoglobin, which is released from lysed erythrocytes on the 2nd to 4th day after the haemorrhage, plays an important role in inducing vasospasm. An inflammatory angiopathy ensues, with complete resolution after 6-12 weeks. The cerebral blood flow (CBF) is reduced depending on the extent of vasospasm. Irreversible infarction may follow the decrease of CBF below a critical value. Severe vasospasm causes autoregulatory disturbances and reduced responsiveness of cerebral vessels to CO2. CALCIUM ANTAGONISTS. The calcium blocker nimodipine causes dilatation of small pial vessels with increased CBF. However, systemic vasodilation with the subsequent fall in blood pressure may limit the increase in CBF. Furthermore, it is known that nimodipine decreases intracellular calcium concentrations resulting in some protection against ischaemic cellular injury. Seven placebo-controlled clinical studies have shown that nimodipine improves the outcome of patients with severe neurological damage due to cerebral vasospasm. HYPERVOLAEMIC HAEMODILUTION. Volume expansion and haemodilution to a hematocrit of 30%-33% is suggested to improve cerebral perfusion during vasospasm. The central venous and pulmonary capillary wedge pressures should be 10-12 mm Hg and 15-18 mm Hg, respectively. But there is no evidence of improved outcome with this measure, and pulmonary edema is a frequent side effect. However, impairment of cerebral perfusion and increased neurological damage can be demonstrated with hypovolaemia and haemoconcentration. INDUCED ARTERIAL HYPERTENSION. In the presence of cerebral vasospasm and resulting autoregulatory disturbances, cerebral perfusion can be increased by raising systemic arterial pressure. This measure, too, fails to improve neurological outcome. CONCLUSION. Treatment of cerebral vasospasm following a SAB aims to avoid any impairment of cerebral perfusion. Hypovolaemia and haemoconcentration have to be corrected. Normoventilation should be established to avoid hypocapnic vasoconstriction. Nimodipine should be administered continuously after a SAB. In view of the autoregulatory disturbances, systemic hypotension with its danger of decreased CBF must be prevented. The importance of hypervolaemic haemodilution and/or induced arterial hypertension is not clear. Despite therapeutic efforts, the number of patients who have survived a SAB without a substantial neurological deficit has not increased.

Aneurysm, Ruptured↗
PubMed1995

[Obstruction of a spiral anesthesia tube in a pediatric circuit system].

A separation of the individual latex layers is a known complication of endotracheal armoured tubes manufactured by immersion technique. This can result in herniation into the lumen with obstruction of the tube. Diffusion of nitrous oxide into the inner hernia considerably intensifies the obstruction. This can lead to life-threatening situations. We observed a similar herniation caused by layer separation with subsequent tube obstruction of silicolatex anaesthesia tubes used in paediatric circuit systems. This is caused by manufacturing defects and above all by damage incurred in reprocessing. Therefore it is important to process the tubes carefully. A too-high drying temperature can cause premature layer separation. The tubes should never be processed more than 80 times. Routine examination of the tubes is imperative, especially at the predilection sites for layer separation.

Anesthesia↗
PubMed1995

Drug-related fatal anaphylactic shock in Denmark 1968-1990. A study based on notifications to the Committee on Adverse Drug Reactions.

Based on notifications to the Danish Committee on Adverse Drug Reactions and to the Central Death Register, 30 cases of fatal drug-induced anaphylactic shock were identified during the period 1968-1990. The most frequent causes were contrast media for X-ray examinations, antibiotics, and extracts of allergens. Nine cases occurred outside hospital; they were mainly caused by the use of allergen extracts of moulds for desensitization in general practice. Fatal drug-induced anaphylactic shock is rare, estimated in the present study at 0.3 case per million inhabitants per year.

Adolescent↗
PubMed1995

Video-assisted thoracoscopic surgery for congenital heart disease.

Video-assisted endoscopic techniques have reduced operative trauma in adult thoracic and general surgery, but applications in children with congenital heart disease have been limited. We report the development of video-assisted thoracic surgery procedures for neonates and infants with cardiovascular disease. Endoscopic instruments and techniques for pediatric cardiovascular procedures were designed and tested in the animal laboratory. Forty-eight operations were subsequently performed in 46 pediatric patients ranging in age from 2 hours to 14 years (median 9 months), weighing from 575 grams to 54 kg (median 8.5 kg). Clinical applications included seven different surgical procedures: patent ductus arteriosus interruption in infants (n = 26) and premature neonates (n = 5), vascular ring division (n = 8), pericardial drainage and resection (n = 3), arterial and venous collateral interruption (n = 2), thoracic duct ligation (n = 2), epicardial pacemaker lead insertion (n = 1), and diagnostic thoracoscopy (n = 1). There was no operative mortality. Technical success, defined as a video-assisted procedure completed without incising chest wall muscle or spreading the ribs, was achieved in 39 of 48 procedures (82%), with thoracotomy required to complete nine procedures. Most patients (22/25, 88%) undergoing elective ductus ligation were extubated in the operating room and discharged from the hospital within 48 hours of the operation. Eight of the last 10 patients having ductus ligation were discharged on the first postoperative day. Residual ductal flow was assessed by (1) transesophageal echocardiography in the operating room (incidence: 0/25, 0%, 70% CL 0% to 7.3%); (2) discharge auscultation (incidence: 1/30, 3%, 70% CL 0.5% to 10.8%); and (3) follow-up Doppler echocardiography (incidence: 3/25, 12%, 70% CL 5.4% to 22.6%). Video-assisted thoracoscopic techniques can be safely applied to pediatric patients with patent ductus arteriosus and vascular rings and may become an effective addition to the staged management of more complex forms of congenital heart disease.

Adolescent↗
PubMed1995

The C. elegans sex-determining gene fem-2 encodes a putative protein phosphatase.

The genetic and molecular analysis of genes involved in the regulation of sex determination in Caenorhabditis elegans suggests that the gene fem-2 plays an important role in regulating a pathway transducing a non-cell-autonomous signal to a nuclear transcription factor. The wild-type fem-2 gene was cloned by identifying sequences from the C. elegans physical map that could restore normal Fem-2 function to homozygous mutant fem-2 transgenic animals. cDNA sequences mapping to the minimal rescuing region correspond to an open reading frame with a sequence similar to protein phosphatase 2C enzymes from systems as diverse as yeast, humans, and plants, but the alignments suggest that FEM-2 falls into a separate class of proteins than the canonical homologues. Several fem-2 mutant alleles were sequenced, and the mutations are predicted to cause protein changes consistent with their observed phenotypes, such as missense mutations in conditional alleles, and a nonsense mutation in a predicted null allele. This is the first evidence implicating phosphorylation and/or dephosphorylation as a control mechanism in C. elegans sex determination.

Alleles↗
PubMed1995

Ontogeny of human mannan-binding protein, a lectin of the innate immune system.

Mannan-binding protein (MBP) is a member of the collectins. These lectins are composed of polypeptide chains which contains a collagen-like region and a calcium dependent carbohydrate recognition domain (named a C-type CRD). MBP binds via the CRD to carbohydrate structures on microorganisms. MBP can activate the complement system when bound to carbohydrate. MBP is thus thought to play a role in the defence against microorganisms. The present report describes the ontogeny of MBP. The level of MBP increase during the first 3 months of life, at which time a stable level is reached, comparable to that seen in adults. On average, the level of MBP at term was 37% of the post 3-month level. Measurements on infants born prematurely showed a 3-fold increase in MBP concentration from the time of birth at around 30 weeks from conception to the 10th week of life.

Carrier Proteins↗
PubMed1995

Suspected scaphoid fractures. Can we avoid overkill?

Among 231 patients with clinical signs of a fractured carpal scaphoid but negative primary radiographs, only 3 fractures of the scaphoid were finally diagnosed on subsequent radiological and clinical examinations. Two of these could be seen retrospectively in the primary radiographs. After an observation period of two to three weeks in dorsal plaster casts, 88.8% of the patients were discharged from the outpatient department as having soft-tissue injuries. They required no further treatment. This "overkill" is unsatisfactory, as we agree with other studies that almost 100% of factual fractures of the scaphoid bone are visible on initial radiographs of good quality, using 4 or 5 different views and evaluated by a senior radiologist. We propose a more stringent clinical inclusion into the category of "clinical scaphoid fracture" and the use of simple supportive bandages in an observation period.

Adolescent↗
PubMed1994

[Kawasaki disease. Incidence in Denmark during the period 1981-1990].

The aim of the study was to estimate the incidence of Kawasaki's disease and to describe the clinical manifestations and the prognosis of the disease in children in Denmark during the period 1981-1990. In a register of all hospital admissions in Denmark, 99 patients were registered as having Kawasaki's disease. Of those, 89 patients fulfilled the clinical diagnostic criteria. The mean incidence of the ten year period was 1.0 per 100,000 children per year. The incidence of the disease decreased in the age group from zero to seven years after which it was rarely observed. Typical laboratory findings were hypersedimentation, leucocytosis and thrombocytosis. Eight children had cardiomegaly and three had electrocardiographic changes. Echocardiography was performed in 66 patients showing coronary artery aneurysms in nine patients (14%) (six boys and three girls). No further cardiac complications were found.

Adolescent↗
PubMed1994

[Cardiac effects of atropine in patients treated with antidepressive medication].

UNLABELLED: It is often suggested that atropine should be avoided in patients on treatment with tricyclic or tetracyclic antidepressants. It is feared that the strong anticholinergic side effects of these drugs could exaggerate the effects of atropine on the heart. METHODS: In a controlled prospective study, 31 patients on treatment with tri- or tetracyclic antidepressants were given atropine in incremental doses. ECG-changes and changes in heart rate were recorded and compared to a control group. Atropine 2 micrograms/kg was administered in 60 sec. intervals up to a total dose of 10 micrograms/kg. RESULTS: The patients on antidepressant treatment had a higher incidence of common anticholinergic side effects (dryness of mouth, accommodation disorders, constipation) due to the anticholinergic properties of the antidepressants. In addition, the basal heart rate of these patients was significantly higher compared to the control group (81/min vs. 73/min). After administration of 2 and 4 micrograms/kg of atropine the patients of the control group showed a 5% resp. 4% decrease in heart rate. 26% of these patients developed conduction disturbvances. These changes could be explained by the parasympathetic effect of low doses of atropine. They were less pronounced in the patients on treatment with antidepressants. Here, only the administration of 2 micrograms/kg of atropine led to a 2% decrease in heart rate. Only 6% of these patients developed conduction disturbances. Both groups showed an increase in heart rate when higher doses of atropine were administered (8 and 10 micrograms/kg). However, the increase in heart rate after administration of 10 micrograms/kg was significantly less in the patients on antidepressant treatment compared to the control group (11.4% vs. 16.2%). There were no changes of blood pressure during these investigations. CONCLUSION: The results of this study suggest that the anticholinergic properties of tri- and tetracyclic antidepressants include an increase in basal heart rate, but do not render the heart more susceptible to the cardiac effects of atropine.

Adult↗
PubMed1994

Prenatal stressors of human life affect fetal brain development.

In a population-based study, 3021 women in a central Copenhagen district received a questionnaire on environmental and psychological factors during mid-gestation. Of these, 70 women were selected consecutively on the basis of moderate to severe stressful life-events (DSM-III-R categories 3 to 5), in combination with an inadequate social network. They were compared with 50 non-stressed women with an intact social network. Stress and smoking significantly affected birthweight and head circumference. When birthweight was corrected, stress remained a significant determinant of small head circumference, indicating a specific effect on brain development. Stress also led to a suboptimal Prechtl neonatal neurological score. These findings suggest the existence of a fetal stress syndrome with adverse effects on fetal development, including deficient brain development.

Brain↗
PubMed1993

[Utilization of the right to maternity leave and resumption of work after delivery. A longitudinal prospective study].

A longitudinal interview study of 360 mothers was carried out to investigate: 1) utilization of maternity leave by the parents, 2) mothers' resumption of occupation after delivery and 3) duration of breast feeding seen in correlation with the mothers' resumption of work. 1) 95% of the families utilized the entire maternity leave. In 92% of the families, the mothers utilized all 24 weeks and, in 3% of the families, the fathers took part in the maternity leave. Only 46% of the fathers utilized the right to take leave in connection with delivery and 14% employed their holiday but were at home for a significantly shorter period. 2) Only one fourth of the mothers had resumed work 24 weeks after the delivery. 44% of the mothers prolonged the maternity leave with their holiday and 32% prolonged the maternity leave even longer. One year after delivery, significantly more mothers were housewives than previously. 3) A significantly positive correlation was found between the time for maternal return to work and the duration of breast feeding. We conclude that almost all of the families utilized the maternity leave and that prolongation of maternity leave (which is 24 weeks after delivery at present) might be necessary.

Denmark↗
PubMed1993

Solid-state NMR analysis of crosslinking in mussel protein glue.

Solid-state 13C and 15N NMR spectra have been obtained of intact adhesive plaques from the mussel Geukensia demissa labeled by L-[6-13C,6-15N]lysine. The plaques are rich in a polyphenolic protein glue which has 50 or more repeats of a nonapeptide sequence with one lysine per repeat. The average isotopic 15N enrichment of lysyl epsilon nitrogens in the plaques was 4%. These lysyl amines are not involved in ionic complexes and do not form observable concentrations of covalent crosslinks.

Animals↗
PubMed1993

IgE levels in cord and capillary blood at 5 days of age.

We have determined the correlation between IgE in cord blood and capillary serum from 98 mature children at 5 days of age. Sixty-six per cent had no family history of atopy, 29% had a single and 5% a double disposition. The study showed a good correlation, rho = 0.75, p < 10(-5), between IgE levels in cord blood and capillary blood samples drawn on the 5th day of life in children both with and without a heredity of atopic diseases. There was no correlation between the concentrations of cord blood IgE and IgA.

Capillaries↗
PubMed1993

[Ethical and psychological aspects of screening tests for children].

The increase in the incidence of screening procedures has been accompanied by increased awareness of the ethical and psychological problems involved, particularly in conjunction with the detection of diseases in children. Before a screening programme is launched, the ethical and psychological consequences for children and their families should be evaluated, as well as what supportive measures may be necessary to minimize the psychological effects of positive and false-positive test results. Moreover, it should be carefully determined which age is the most appropriate for screening with a view to the possibility of initiating prophylactic treatment and minimizing the adverse effects of stigmatization.

Child↗
PubMed1993

[Perioperative cardiovascular reactions and the noradrenaline plasma level in patients on chronic antidepressant medication].

UNLABELLED: It is still controversial whether the perioperative incidence of cardiovascular complications is increased in patients on chronic treatment with cyclic antidepressants (AD) and whether AD medication should be discontinued prior to surgery. METHODS. We measured perioperative cardiovascular variables in 31 patients on chronic treatment with tri- and tetracyclic AD and 31 patients without AD medication. Heart rate, blood pressure, and noradrenaline plasma concentrations were compared between the two groups at nine points in time. During induction of anaesthesia, the ECG was recorded continuously. After the administration of 0.01 mg/kg atropine i.v., all patients received opiate-supplemented enflurane anaesthesia. RESULTS: Re-uptake inhibition of noradrenaline by AD resulted in significantly higher noradrenaline plasma concentrations before and during anaesthesia in the AD-treated group. The incidence of arrhythmias, blood pressure elevations, and tachycardia was not increased in patients in AD treatment. Arrhythmias during induction of anaesthesia were seen in 6 of the AD-treated patients and 5 of the controls. Blood pressure elevations by more than 35% were seen in 10 patients on AD treatment and 8 controls. The heart rate prior to induction of anaesthesia and 2 h after the end of surgery was significantly higher in the AD-treated group. During anaesthesia the heart rate was higher at two points in time only. The incidence of tachycardia was similar in both groups. Intravenous administration of 0.01 mg/kg atropine prior to induction of anaesthesia increased the heart rate of the patients on chronic AD medication by 11.4%. This increase was significantly higher in the control group (16.2%), suggesting that patients with chronic AD treatment do not have a higher sensitivity to atropine. CONCLUSION: The elevated noradrenaline plasma levels in patients on chronic AD treatment did not result in a higher incidence of arrhythmias, blood pressure elevations, or tachycardia perioperatively. Taking these results into account, we do not consider it necessary to discontinue chronic AD medication prior to surgery in patients without cardiovascular disease.

Antidepressive Agents↗