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A Nielsen

Publications and source records attributed to A Nielsen.

At least 55 records · Page 3Linked to original sources
PubMed1988

Cyclical changes in endogenous overnight creatinine clearance during the third trimester of pregnancy.

To investigate the pattern of change in endogenous overnight creatinine clearance during the third trimester, 12 healthy women with uncomplicated pregnancies were examined three times a week. Urine was collected overnight from 22.00 to 08.00 hours and analysed for creatinine. Serum was sampled in the morning and analysed for creatinine, beta 2-microglobulin, progesterone and estradiol. The general trend of creatinine clearance was parabolic with a declining level during the last month before term. A sinusoid pattern with minimum values around the time when the women would have had menstruation had they not become pregnant was superimposed on the parabolic trend. A mathematical model (parabolas overlaid with a cosine curve) was constructed and fitted to the data. The cyclical pattern was significant. Serum creatinine showed a pattern with increasing values during the last 4-6 weeks before term and cyclical changes which were also significant. In the individual case the monthly and preterm clearance decrement sometimes was over 50%. Monthly and preterm decreases in creatinine clearance may be quite normal and serial measurements of creatinine clearance are therefore necessary to determine if declining values indicate pathological falls in the glomerular filtration rate.

Adult↗
PubMed1986

Primary malignant lymphoma of the salivary glands.

Five cases of primary malignant lymphomas of the salivary glands are reported. Four lymphomas arose in the parotid gland and one in the submandibular gland. All were non-Hodgkin lymphomas. In 4 cases the lymphomas were of low-grade malignancy, viz. 2 immunocytomas and 2 centroblastic/centrocytic malignant lymphomas, and 1 was a T-immunoblastic malignant lymphoma of high-grade malignancy. Four patients with localized disease were treated with radiotherapy and 1 patient with disseminated disease was treated with chemotherapy. One patient died from a disease unrelated to the malignant lymphoma, and 4 patients were alive at 66-136 months after treatment.

Aged↗
PubMed1986

Long-term follow-up of von Recklinghausen neurofibromatosis. Survival and malignant neoplasms.

To document the natural history of von Recklinghausen neurofibromatosis, we followed up a nationwide cohort of 212 affected patients and families identified in Denmark 42 years ago. We obtained follow-up information on 99 percent. Because all 76 probands were identified through hospitals, they may include a disproportionate number of severe cases of neurofibromatosis. To diminish this effect of selection bias, we distinguished between the probands and their affected relatives. In a comparison with the general population, survival rates were significantly impaired in relatives with neurofibromatosis, worse in probands, and worst in female probands. Malignant neoplasms or benign central nervous system tumors occurred in 45 percent of the probands, giving a relative risk of 4.0 (95 percent confidence limits, 2.8 to 5.6) as compared with expected numbers. Multiple primary neoplasms were found in 15 probands, but only 1 relative. Compared with the general population, male relatives with neurofibromatosis had the same rate of neoplasms, whereas female relatives had a nearly twofold higher rate (relative risk, 1.9; 1.1 to 3.1). Nervous system tumors were disproportionately represented. We conclude that patients with severe neurofibromatosis requiring hospitalization often have a poor prognosis, but incidentally diagnosed relatives may have a considerably better outcome.

Brain Neoplasms↗
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

Number of "high genes" involved in determining the activity of paraoxonase.

The genetics of paraoxonase activity is further analysed on the basis of a Danish family material (Eiberg & Mohr 1981), namely a random sample of the investigated two mating types. The starting point is the earlier assumption that the segregation into high and low activity is due to alleles on a single locus with the frequency 0.726 of low genes (Eiberg & Mohr 1981, Nielsen et al. 1986). It is shown that a hypothesis of two "high genes", h1 and h2 on the same locus, with allele frequencies 0.117 and 0.157, both high genes being dominant over low genes and h2 dominant over h1, may explain the observed pattern of segregation. The hypothesis would imply average activities of genotype 1h1 of 960 microM PNP/1, of 1h2 1385 microM PNP/1, of h1h1 1202 microM PNP/1, and of h1h2 and h2h2 2048 microM PNP/1. It cannot be excluded that there are more than two "high genes". It is further shown that more than one "low gene" must be involved.

Alleles↗
PubMed1986

Number of loci responsible for the inheritance of high and low activity of paraoxonase.

On the basis of a Danish family material of Eiberg & Mohr (1981), especially 416 matings with 1595 children where the one parent has high activity of paraoxonase and the other low activity, and the 185 matings with 684 children where both parents have high activity, it is, by consideration of a two-loci model and other alternatives besides the earlier suggested one-locus model, confirmed that segregation into high and low activity is largely or exclusively due to a one-locus system; in case any secondary locus is involved, its most common allele would probably have a frequency above 0.95.

Adult↗
PubMed1986

Comparison of characteristics of human small cell carcinoma of the lung in patients, in vitro and transplanted into nude mice.

Specimens from 24 patients with metastatic small cell carcinoma of the lung were explanted in vitro as well as transplanted directly into nude mice. A method to obtain fibroblast-free cultures is described. This method resulted in cell lines which could be grown for more than one year in 79% of the cases. Fifty-four % of the tumours could be established as serially transplantable tumours in nude mice. The tumours were characterized by histology, electron microscopy, DNA index, and cell cycle distribution. The in vitro cell lines were furthermore characterized by the plating efficiency and by doubling time. The macroscopic growth of the heterotransplanted tumours was ascribed to a transformed Gompertz function. The tumour cells preserved their light microscopic constitution of small cell carcinoma of the lung in the model systems. The heterogeneity of the original tumours was reflected in vitro and in nude mice and the model systems thus allows an expression of the inherent heterogeneity and instability. The panel of transplantable tumours and the in vitro cell lines offer the study of biology inclusive of tumour progression of SCCL.

Animals↗
PubMed1986

Onset of the release of spermatozoa (spermarche) in boys in relation to age, testicular growth, pubic hair, and height.

The onset of production of spermatozoa (spermarche) is the basis for achievement of reproductive capacity in men. We collected 24-h urine samples every 3 months in a 7-yr longitudinal study of 40 normal boys initially aged 8.6-11.7 yr. After centrifugation, the urine was analyzed for the presence of spermatozoa by microscopic examination, and spermarche was estimated on the basis of age at first observed spermaturia. The results were corrected for the intermittent occurrence of spermatozoa in the urine after first observed spermaturia and the fact that the urine samples were collected quarterly. In addition, physical examination, including determination of testicular size by orchidometer measurement, pubic hair distribution (Tanner stage), and height, was carried out every 6 months. Spermarche occurred at a median age of 13.4 yr (range, 11.7-15.3 yr), at a time when testicular size was 4.7-19.6 ml (median, 11.5 ml), and pubic hair distribution was 1-5 (median, 2.5). In most boys, spermarche preceded the age of peak height velocity (median, 13.8 yr; range, 12.2-15.2 yr); at the time of spermarche, median peak height growth velocity was 9.9 cm/yr (range, 7.5-13.4 cm/yr), and median height was 160.4 cm (range, 151.7-175.9 cm). We conclude that spermarche is an early pubertal event and that a wide variation in testicular size and secondary sex characteristics is found at that time. In particular, spermarche may occur when little or no pubic hair has developed, and the testes have grown only slightly.

Adolescent↗
PubMed1986

[Barodontalgia].

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Adolescent↗
PubMed1985

Endocrine sensitivity of the receptor-positive T61 human breast carcinoma serially grown in nude mice.

A study was made on the effect of ovariectomy, 17 beta-oestradiol, and tamoxifen on the oestrogen and progesterone receptor-positive T61 human breast carcinoma grown in nude mice. The effect of the treatment was evaluated by the specific growth delay calculated on the basis of Gompertz growth curves, and by the changes in the cell cycle distribution monitored by flow cytometric DNA analysis. The results demonstrated that both oestradiol and tamoxifen induced a temporary growth delay, whereas ovariectomy of the host had no effect on the growth of the tumour. The oestradiol-induced tumour growth delay was accompanied by a decrease in the G1 fraction, an accumulation of cells in the S-phase, and polyploidy, whereas neither treatment with tamoxifen nor ovariectomy influenced cell cycle distribution. The results indicate that oestradiol and tamoxifen have different mechanisms of action. In addition, they were interpreted as indicating different mechanisms regulating ovarian-dependent tumour growth, on the one hand, and oestrogen and tamoxifen-induced tumour growth inhibition, on the other. The results support the view that the presence of receptors may be of importance but is not a sufficiently clear marker to allow prediction of the endocrine sensitivity of individual breast tumours.

Animals↗