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Biomedical subjects

S Nilsson

Publications and source records attributed to S Nilsson.

At least 379 records · Page 21Linked to original sources
PubMed1985

Long-term use of oral contraceptives and cervical neoplasia: an association confounded by other risk factors?

One-hundred-and-forty women with cervical intraepithelial neoplasia (CIN) found during pregnancy were compared to 280 pregnant age-matched controls. Information was obtained on obstetrical and gynecological history, sexual behaviour, contraceptive use and smoking of the female and of the male partner. Oral contraceptive use for 60 months or more was significantly associated with CIN. This significance vanished when the effect of confounding factors was controlled for in a log-linear analysis. According to these results, long-term oral contraceptive use does not seem to be a causal factor of CIN, but these women constitute a high risk group due to sexual history and smoking habits and should thus be referred for a regular cytological screening.

Adolescent↗
PubMed1985

Substance P acts by releasing 5-hydroxytryptamine from enteric neurons in the stomach of the rainbow trout, Salmo gairdneri.

The effect and mode of action of substance P was studied in a perfused stomach preparation and on isolated strip preparations of the stomach wall from the rainbow trout, Salmo gairdneri. Substance P was excitatory on the stomach muscle wall in a dose-dependent manner. Two other tachykinins, physalaemin and eledoisin, excited the preparations in a similar manner and in the same dose range. The effect of substance P was not antagonized by the substance P analogues [D-Pro2, D-Phe7, D-Trp9]substance P and [D-Pro2, D-Trp7,9]substance P (both 10(-5) M). Tetrodotoxin reduced or abolished the effect of substance P, while no reduction of the response was obtained after atropine, chlorisondamine or phentolamine (all 10(-6) M). 5-Hydroxytryptamine excited the stomach and this effect was not antagonized by tetrodotoxin, suggesting that the action of 5-hydroxytryptamine was direct on the smooth muscle. The 5-hydroxytryptamine antagonist methysergide, in a concentration which selectively blocked the response to 5-hydroxytryptamine, also blocked the response to substance P (10(-9)-10(-8) M). The outflow of 5-[3H]hydroxytryptamine from a preloaded perfused stomach was clearly increased by substance P, and this release was blocked by tetrodotoxin. Immunohistochemistry revealed the presence of nerve fibres and ganglion cells showing 5-hydroxytryptamine-like immunoreactivity in the myenteric plexus and smooth muscle layers of the stomach wall. The immunoreactive cells and nerve fibres were particularly abundant in the pyloric part of the stomach. It is concluded that the main effect of substance P on the stomach wall of the rainbow trout is indirect, via activation of a non-adrenergic, non-cholinergic neuron. The results are compatible with the view that this neuron exerts its action by release of 5-hydroxytryptamine. Supramaximal concentrations (greater than or equal to 10(-7) M) of substance P may in addition have a direct effect on the gastric smooth muscle.

Animals↗
PubMed1985

D- and L-isoprenaline have different effects on adrenoceptors in the systemic vasculature of the cod, Gadus morhua.

The effects of D- and L-isoprenaline on systemic vascular adrenoceptors of the cod was studied using blood pressure recording from conscious cod in vivo and isolated coeliac artery strip preparations in vitro. Experiments with isolated artery preparations demonstrated that the D-, but not the L-isomer of isoprenaline acts as an alpha-adrenoceptor antagonist. A dose-dependent reduction of ventral and dorsal aortic blood pressures together with a dose-dependent increase in the heart rate could be produced by injection of L-isoprenaline. D-Isoprenaline, on the other hand, had no effect on the blood pressures or heart rate except in the highest dose injected. The results show an alpha-adrenoceptor blocking capacity of D-isoprenaline in the cod. The effect of L-isoprenaline on the blood pressure supports the idea that the hypotensive effect of DL-isoprenaline seen in previous studies of the cod may be attributed to an effect of the L-isomer on beta-adrenoceptors mediating vasodilation of the cod systemic vasculature.

Animals↗
PubMed1985

Testicular germ cell tumors after clomiphene therapy for subfertility.

The stimulatory effect of low doses of clomiphene citrate on the human male gonad is accepted widely. We used 25 mg. clomiphene daily for 3 weeks, with 1 week of rest, for 6 to 12 months in 650 oligospermic men without increased serum levels of follicle-stimulating hormone (less than 20 IU/l.). Unilateral testicular neoplasm developed in 2 subjects. Although a definite cause-and-effect relationship between treatment and tumor development cannot be assigned the possible risk of tumor development in men undergoing long-term clomiphene treatment is suggested. Since clomiphene administration or gonadotropin treatment might enhance tumor development in men, patients at risk undergoing such therapy should be examined frequently and when a testicle enlarges a malignant tumor must be ruled out.

Adult↗
PubMed1985

Renal and extra-renal excretion of calcium in the marine teleost, Gadus morhua.

The calcium turnover, with particular emphasis on the routes and rates of excretion, was investigated in the Atlantic cod, Gadus morhua. A very rapid internal redistribution of injected 45Ca was demonstrated, with the decline in the plasma concentration conforming to the power function f(t) = 8.83% X t-0.585. The clearance for 45Ca and [3H]inulin were both linearly correlated to urine flow and showed a ratio (Cca/CIn) of 2.6:1. Likewise a linear correlation between the renal and extra-renal excretion of 45Ca could be demonstrated with a ratio of 1:0.47, indicating that the renal route of excretion is of major importance in this species. The renal excretion of calcium was estimated to be 4.2 mumol X kg-1 X h-1 and the total calcium excretion to be 6.2 mumol X kg-1 X h-1. Calculations are presented, suggesting that the balance between intake and excretion of calcium can be explained in terms of growth of the animal, which would allow for an increase in the amount of body calcium of approximately 5 g X yr-1. It is also concluded that because about two-thirds calcium is excreted via the renal route, the kidneys may be the most important site for the regulation of calcium excretion in the cod.

Animals↗
PubMed1985

Nervous control of the blood pressure in the Atlantic cod, Gadus morhua.

Dorsal (PDA) and ventral aortic blood pressure (PVA) and heart rate (HR) were measured in conscious resting cod, Gadus morhua L., which has been allowed 24 h recovery from surgery. Plasma adrenalin and nonadrenalin concentrations in these fish were 3.4 and 2.2 nmoll-1 respectively, and thus lower than previously reported values from partially recovered cod. Twenty-four hours after treatment with the adrenergic neurone blocking agent bretylium, PDA was significantly reduced by 17% compared to sham-injected controls, although PVA and heart rate were unaltered. Subsequent alpha-adrenoceptor blockade by phentolamine produced no further fall in PDA and no changes in PVA or HR, provided a 5-h period was allowed to overcome the acute toxic side effects of phentolamine. The effectiveness of the bretylium or phentolamine blockade was confirmed by noting the absence of any vasoconstrictor response during sympathetic nerve stimulation in perfused tails from fish used in the in vivo experiments. Bretylium had no significant effect on the sensitivity of the isolated coeliac artery to adrenalin, but effectively blocked the adrenergic innervation of this artery or the vasculature of the tail. Evidence for a non-selective blockade of non-adrenergic nerves to the heart was also obtained. It is concluded that the adrenergic tonus affecting the dorsal aortic blood pressure in resting cod that have recovered for 24 h following surgery is due solely to an adrenergic nervous tone.

Animals↗
PubMed1985

Control of the heart in the mudpuppy, Necturus maculosus.

The cardiac innervation of the mudpuppy, Necturus maculosus, was investigated using in vivo recording of blood pressure and heart rate, a perfused heart preparation, isolated paced ventricular and atrial strip preparations, Falck-Hillarp fluorescence histochemistry and measurements of plasma concentrations of catecholamines. The heart of Necturus receives a 'classical' vagal inhibitory innervation by cholinergic fibres which act via muscarinic cholinoceptors. In addition, there appears to be an atropine-resistant inhibitory component in the vagal innervation of the heart. This component is best seen at higher frequencies of vagal stimulation (10-20 Hz), but the mechanism behind this response is not known. There is no direct adrenergic innervation of the ventricle or atria, but by use of Falck-Hillarp fluorescence histochemistry, adrenergic fibres have been demonstrated at the atrio-ventricular border, particularly within the intracardiac ganglion. The histochemical evidence is consistent with a modulation of the ganglionic transmission in the vagal pathways by adrenergic neurons and small intensely fluorescent (SIF) cells, but physiological evidence is wanting. An adrenergic control of the heart via circulating adrenaline may occur during 'stress', when the plasma level of adrenaline is high enough to affect cardiac performance.

Acetylcholine↗
PubMed1984

Comparison of a triphasic oestradiol/norethisterone acetate preparation with and without an oestriol component in the treatment of climacteric complaints.

This study was undertaken to evaluate the effects of oestriol in combination with oestradiol in the treatment of women with climacteric complaints. Forty-three post-menopausal women were randomly allocated to two groups on a double-blind basis. Over a 28-day cycle 23 of the women were treated sequentially for 12 days with 1 tablet containing 17 beta-oestradiol 2 mg plus oestriol 1 mg, then for 10 days with 1 tablet containing the same oestrogens plus norethisterone acetate 1 mg, thereafter for 6 days with 1 tablet containing 17 beta-oestradiol 1 mg plus oestriol 0.5 mg. The other 20 women received the same treatment but without the oestriol. No clinical, laboratory or histological differences were seen between the two groups. Both treatments were found to be equally effective in alleviating climacteric symptoms, with few side effects. It may be stated in conclusion that, on the basis of routine clinical and laboratory parameters no differences were found between the two preparations.

Adult↗
PubMed1984

Late results after surgical correction of pyeloplasty failure in idiopathic hydronephrosis.

Late results after a secondary pyeloplasty because of failure of the initial procedure were evaluated by glomerular filtration rate and drainage function studies in 15 patients. Total and separate glomerular filtration rates were measured using the 51chromium-ethylenediaminetetraacetic acid clearance technique and isotope renography. The drainage function of the renal pelvis was evaluated from the isotope renogram. Secondary pyeloplasty was performed 1 to 15 years (mean 8.0 years) after the first procedure because of obstruction, which was verified by diuretic urography and isotope renography. Our results show that a secondary pyeloplasty can be performed after failure of the primary procedure. Functional results 3 to 15 years after reoperation were equally good as after uncomplicated primary pyeloplasty.

Adult↗
PubMed1984

Neuronal and extraneuronal uptake of L-3H-adrenaline and L-14C-noradrenaline in the fish spleen.

The neuronal and extraneuronal uptake of adrenaline and noradrenaline in the isolated perfused spleen of the cod has been studied using radiolabelled amines. The neuronal uptake of adrenaline shows an optimum at 0.5 microgram/ml, but is less efficient than for noradrenaline in the concentration range 0.01-2.5 micrograms/ml. The neuronal uptake of noradrenaline accounts for 60-70% of the total (neuronal plus extraneuronal) uptake in the concentration range 0.01-1.0 microgram/ml. At higher concentrations (2.5-5.0 micrograms/ml) the importance of the extraneuronal uptake increases for both amines, to reach more than 90% of the total uptake at 5.0 micrograms/ml. The extraneuronal uptake shows equal efficiency for the two amines throughout the concentration range studied. It is concluded that the cod spleen possesses a neuronal uptake mechanism which shows a higher uptake efficiency for noradrenaline than for adrenaline, while the extraneuronal uptake mechanism shows no preference.

Animals↗
PubMed1984

Vitamin A transfer to the fetus and to the amniotic fluid in rhesus monkey (Macaca mulatta).

The mechanisms of the fetal transmission of vitamin A were investigated by injecting 125I-retinol-binding protein (RBP), 131I-prealbumin and 3H-retinol-RBP in 9 pregnant rhesus monkeys. Samples of blood, amniotic fluid, and when needed fetal liver and kidney were collected after 2.5-48 h. 125I-RBP and 131I-prealbumin were detected in fetal plasma and amniotic fluid already in the first samplings. The specific radioactivity of fetal RBP increased during the first 25 h but never exceeded 13% of the maternal value. This is presumably due to concurrent synthesis of RBP (and prealbumin) by the fetus. The maximum specific activity of 125I-RBP in amniotic fluid was 70% of the maternal value indicating that the protein was predominantly derived from the mother. 3H-retinol was more readily transmitted to fetal plasma than RBP. A significant portion of the 3H activity was found in the lipoproteins suggesting that some retinol enters the fetal circulation by other routes than those involving transmission of RBP. The high specific activity of retinol in the fetal kidney implicates its direct involvement in the turnover of transmitted vitamin A. Quantitatively, however, the accumulation of vitamin A activity was largest in the fetal liver.

Amniotic Fluid↗
PubMed1984

Functional characteristics of idiopathic hydronephrosis.

The functional characteristics of idiopathic hydronephrosis were studied in 171 patients. Conventional renography and measurement of the glomerular filtration rate were performed in all subjects, 137 (79%) of whom had normal parenchymal function despite severely reduced drainage function. Proximal tubular function, measured by determination of beta 2-microglobulin excretion was not reduced. Distal tubular function, evaluated as the maximum concentration ability, was not reduced in 35 of the 89 patients studied. During urography and diuresis renography were both useful tools for verifying the presence of obstruction in doubtful cases. Intrapelvic pressure was measured during constant perfusion at a rate of 7.5 ml/min and during furosemide-induced diuresis. The basal intrapelvic pressure varied from 6 to 10 cm H2O and was not increased in any kidney regardless of the degree of duration of obstruction. During perfusion, the pressure increased and varied from 28 to 52 cm H2O. During diuresis, an increase in pressure above 20 cm H2O was registered only in obstructed kidneys with a normal urinary concentrating ability. The pressure rise never exceeded 20 cm H2O during diuresis in obstructed kidneys with complications such as calculi of previous episodes of upper urinary tract infection. From these studies it is concluded that, besides cases with complications such as urinary tract infection and renal calculi, surgery should be offered to patients with idiopathic hydronephrosis with reduced urinary concentrating ability. In doubtful cases with wide pelves, renography and urography during increased diuresis can be used provided kidney function is not reduced. When kidney function is reduced, a pressure increase above 20 cm H2O during constant perfusion at a rate of 7.5 ml/min indicates obstruction.

Adult↗
PubMed1984

Acute epididymitis and Chlamydia trachomatis.

Prostatitis and epididymitis, which are the most common complications of urethritis in men below 35 years of age may be associated with Chlamydia trachomatis infection. Chlamydiae have been isolated from expressed prostatic fluid in men with urethritis complicated by prostatitis and epididymitis. Epididymitis seem to be an established complication of chlamydial urethritis particularly when urethritis is complicated with prostatitis. Since epididymitis may lead to reduced fertility, prompt antibiotic treatment using tetracyclines should be administered to patients with this condition.

Acute Disease↗