Search PubMed⌕ Search

Biomedical subjects

J Nielsen

Publications and source records attributed to J Nielsen.

At least 379 records · Page 21Linked to original sources
PubMed1987

Seasonality in twin birth rates, Denmark, 1936-84.

A study was made of seasonality in twin birth rate in Denmark between 1977 and 1984. We studied all twin births (N = 45,550) in all deliveries (N = 3,679,932) during that period. Statistical analysis using a simple harmonic sinusoidal model provided no evidence for seasonality. However, sequential polynomial analysis disclosed a significant fit to a fifth order polynomial curve with peaks in twin birth rates in May-June and December, along with troughs in February and September. A falling trend in twinning rate broke off in Denmark around 1970, and from 1970 to 1984 an increasing trend was found. The results are discussed in terms of possible environmental influences on twinning.

Birth Rate↗
PubMed1987

Short stature in Scandinavian women. An obstetrical risk factor.

We have carried out a case-controlled study on relations between short stature (i.e. less than 156 cm tall) and problems with childbirth in Danish women. Data obtained from 182 pregnant, short women (short mothers) were compared with those obtained from a control group of 2116 pregnant women who were between 166 and 175 cm tall (control mothers). The prevalence rate for acute cesarean section was three-fold greater in short mothers than in controls, and the prevalence rate for elective cesarean section was twice as high in short mothers as in controls. Moreover, the prevalence rates of intra-uterine asphyxia, intra-uterine growth retardation and low Apgar scores were higher in babies of short mothers than in those of control mothers, despite the increased level of obstetric intervention in the former group. Since the findings show that short stature in pregnant women is an obstetrical risk factor, we recommend that it should be given attention in order to detect early signs of intra-uterine asphyxia and to apply the best form of active management of labor if necessary.

Body Height↗
PubMed1986

Effect of vasoactive intestinal polypeptide (VIP) on steroidogenesis in women.

The VIPergic nervous system appears to be the major peptide-containing neuronal component in the female genital tract. Evidence has been put forward that exogenous VIP is able to stimulate progesterone secretion. In the present study the effect of human VIP (900 pmol/kg body weight per h i.v. during 30 min) on steroidogenesis in six female volunteers was investigated. The experiments were performed between the 6th and 14th day of their menstrual cycle, and peripheral venous blood was collected before, during and after infusion of VIP. The concentrations of VIP, oestradiol, progesterone, testosterone, androstenedione (AD), dihydrotestosterone (DHT), dehydroepiandrosterone sulphate (DHAS), sex hormone binding globulin (SHBG) and cortisol were measured. The infusion of VIP was accompanied by a 15% increase (P less than 0.05) in serum oestradiol concentrations, from a mean basal concentration of 0.58 nmol/l. The concentrations of testosterone and DHT also increased significantly. No effect of VIP on progesterone, AD, DHAS, SHBG or cortisol was observed. In the light of the presence of VIP in nerve fibres of the steroid producing tissue, this stimulatory effect of VIP might reflect a direct action on the ovary or the adrenal gland.

Adult↗
PubMed1986

Application of 2-cyanoethyl N,N,N',N'-tetraisopropylphosphorodiamidite for in situ preparation of deoxyribonucleoside phosphoramidites and their use in polymer-supported synthesis of oligodeoxyribonucleotides.

Deoxyribonucleoside phosphoramidites are prepared in situ from 5'-O,N-protected deoxyribonucleosides and 2-cyanoethyl N,N,N',N'-tetraisopropylphosphorodiamidite with tetrazole as catalyst, and the solutions applied directly on an automatic solid-phase DNA synthesizer. Using LCAA-CPG support and a cycle time of 12.5 min, oligonucleotides of 16-25 bases are obtained with a DMT-efficiency per cycle of 98.0-99.3%. The crude and fully deblocked products are of a purity comparable to that obtained using purified phosphoramidites. In case of d(G)16 the product was difficult to analyse and a better product was not obtained using doubly protected (O-6 diphenylcarbamoyl) guanine.

Base Sequence↗
PubMed1986

Alcohol involvement in violence. A study from a Danish community.

All cases of assaults with violence (n = 1639) from a well defined area were registered for 1 year. A positive alcolmeter test (% greater than 0.2) was registered in 488 cases (29%). A further 216 patients (13%) were found under the influence of alcohol according to a simple clinical judgement. In nine of ten manslaughter and murder cases alcohol was involved. Young men, 19-29 years of age, comprised the majority of victims. Of the episodes of violence 66% took place during the weekend. In 250 cases the alcohol concentration surpassed 1.5%. Almost 50% of the violence episoded took place in or around restaurants. Blunt violence was concerned in 73% of the episodes. Gunshot was registered in five cases, stabbings in two cases.

Adolescent↗
PubMed1986

Serum steroid levels in intact and endocrine ablated BALB/c nude mice and their intact littermates.

An investigation was made of the serum steroid levels found in intact and endocrine ablated nude mice of both sexes and in their intact homozygous littermates. The results showed that nude mice have a normal steroidogenesis, but with decreased levels of circulating steroids compared to those of the littermates. The efficacy of the endocrine ablations was confirmed by the reduction in serum oestrone following oophorectomy, and by the reduction in serum testosterone and progesterone following orchiectomy. The normal steroidogenesis in nude mice, and the similarities between mouse and man with regard to changes in serum steroids following oophorectomy and orchiectomy, support the usefulness of human tumor xenograft models for the study of hormone-tumor interactions.

Animals↗
PubMed1986

Phthalic anhydride-induced occupational asthma.

Out of 118 workers exposed to phthalic anhydride (PA) dust for 2 months or more in four plants producing alkyd and/or polyunsaturated polyester resins, 28 (24%) suffered from work-related rhinitis, 13 (11%) from chronic productive bronchitis, and 21 (28%) from work-associated asthma. Asthma was generally preceded by rhinitis and was mostly of late type. 3 out of 11 asthmatics had a PA-positive skin test. In 2 subjects the presence of antibodies was demonstrated by the Prausnitz-Küstner test. 4 out of 25 heavily exposed subjects without asthma had a nonspecific bronchial hyperreactivity. The results did not indicate any significant 'healthy worker selection' as regarding rhinits and asthma. Chronic productive bronchitis was common and was more prevalent among former workers than among present employees, indicating a selection of nonreacting subjects in the plant. The time-weighted average breathing zone PA levels in two plants were between 3 and 13 mg/m3 during different direct PA handling operations and less than 0.3 mg/m3 at other kinds of work. In 2 subjects, positive bronchial provocation was obtained by short-term exposure to 0.5 and 6 mg PA/m3, respectively.

Asthma↗
PubMed1986

Ketoconazole and cyclosporine A: combined effects on rat renal function and on serum and tissue cyclosporine A concentration.

The effects of ketoconazole (Kcnz) on cyclosporine A (CyA) serum levels and CyA-nephrotoxicity were studied. To rats later anesthetized with pentobarbital sodium, CyA 12.5 and Kcnz 20 mg/kg/day (n = 20), or CyA 12.5 mg/kg and Kcnz-vehicle (n = 21), was dosed. To rats anesthetized with etomidate (n = 14), CyA 12.5 mg/kg and Kcnz-carrier was dosed. S-CyA was monitored during 14 days, and then the rats were investigated with clearance (C) methods (inulin [(in), lithium (Li)], sodium, and potassium), and liver (L) and kidney (K) CyA was measured. Kcnz increased S-CyA, L-CyA and K-CyA (+50 -80%). There were significant (p less than 0.05) correlations between S- and L- or K-CyA. Kcnz increased CyA nephrotoxicity: Mean Cin was 1.012 ml/min/gKW (kidney weight) after CyA treatment (a subnormal value), but decreased to 0.556 ml/min/gKW in the group also given Kcnz (p less than 0.001). CLi decreased from 0.135 to 0.048 ml/min/gKW (p less than 0.001), and absolute proximal tubular reabsorption decreased from 0.877 to 0.508 ml/min/gKW (p less than 0.001), while the fractional reabsorption in the proximal tubule (FPR), expressed as a percentage of GFR, increased from 86.9 to 91.6% (p less than 0.005). Thus, after Kcnz treatment to rats given CyA 12.5 mg/kg/day, their renal function was indistinguishable from that in rats given CyA 25 mg/kg/day.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia↗