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Biomedical subjects

B Bergman

Publications and source records attributed to B Bergman.

At least 199 records · Page 11Linked to original sources
PubMed1985

Testosterone-induced decrement of prostatic vascular resistance in rats is reversed by estrogens.

The function and growth of the rat prostate are stimulated by androgens and inhibited by estrogens. To study the influence of these hormones on the prostatic blood flow, prostatic vascular resistance was measured in castrated adult rats, which were testosterone supplemented and treated with different estrogenic substances. Prostatic blood flow was measured using the microsphere technique. Testosterone supplementation for 8-9 days after castration resulted in decreased vascular resistance in both the ventral and dorsolateral prostates. In testosterone-supplemented rats, treatment for the same period of time with estradiol benzoate, ethinyl estradiol, and diethylstilbestrol induced increased vascular resistance in both the ventral and dorsolateral prostates. However, treatment with estromustine or estramustine did not change prostatic vascular resistance significantly. It was concluded that the testosterone-induced decrease of prostatic vascular resistance was reversed by estradiol, ethinyl estradiol, and diethylstilbestrol, possibly by a direct effect on the prostate.

Animals↗
PubMed1985

Clinical long-term study of complete denture wearers.

Thirty-two patients initially treated with a complete denture in the maxilla or mandible were examined after 21 years. The examination included a questionnaire plus clinical and radiographic examinations. Denture function was assessed in general as very good or fairly good by the patients, but about half of the subjects also felt that the dentures needed some attention. The patients generally had a high evaluation of their chewing ability. The functional state of the masticatory system, both according to patients' reports and the clinical signs, was generally good compared with previously published epidemiologic studies. The denture quality and tissue health were far from optimum according to prosthodontic criteria. By overall judgment, 14 patients needed new dentures and six needed relining, occlusal adjustment, or repair. Tracing of cephalometric radiographs showed wide variations in bone resorption among patients.

Adult↗
PubMed1985

Integration of stimulus dimensions in perception and memory: composition rules and psychophysical relations.

A series of five experiments used the method of magnitude estimation to assess how height and width are integrated in perceptual and in memorial judgments of area. Separate groups of subjects estimated the areas of perceived or remembered rectangles produced by a symmetrical 4 X 4 factorial design of height and width. Additional independent groups of observers made area judgments, based on special mixes of perceptual and memorial information referring to the height and width components of the to-be-judged rectangles. Both perceptual and memory data obeyed the bilinear interaction prediction of the normative multiplicative model. The relation between perceived and actual area as well as the relation between remembered and actual area could both be described by a compressive power function, with the exponent being reliably smaller for remembered than for perceived area. These results seem to imply a principle of integration rule invariance across perceptual and memorial estimates of a given set of stimuli, in conjunction with characteristically different valuation operations.

Adult↗
PubMed1985

Effects of Aminooxyacetate and Aminoacetonitrile on Glycolate and Ammonia Release by the Cyanobacterium Anabaena cylindrica.

Aminooxyacetate and aminoacetonitrile cause increased excretion of glycolate by the cyanobacterium Anabaena cylindrica. Both compounds also reduce NH(4)-N release induced by methionine sulfoximine in non-nitrogen-fixing cultures. Changes in amino acid pool sizes together with changes in activities of some enzymes related to glycolate metabolism show that glyoxylate to glycine conversion and glycine to serine conversion are inhibited by aminooxyacetate and aminoacetonitrile, respectively. The results also verify that photorespiratory glycolate metabolism via amination of glyoxylate is operative in A. cylindrica.

Journal Article↗
PubMed1985

Effects of human chorionic gonadotrophin, oestradiol and estromustine on testicular blood flow in hypophysectomized rats.

The effects of human chorionic gonadotrophin (hCG), eostradiol benzoate (E2) and estromustine (Eo) on testicular and prostatic blood flow and plasma levels of testosterone were studied in hypophysectomized rats. Daily injections of 5 IU hCG induced a significant increase in testicular blood flow when measured after 8-9 days treatment. This stimulatory effect was inhibited by concomitant injection of E2 (50 micrograms/day) but not by Eo. In contrast, the stimulatory effect of hCG on plasma levels of testosterone was inhibited by administration of E2 as well as by Eo. This inhibition was correlated with decreased blood flow to the prostate. The present study gives further support to the hypothesis the oestrogens have direct effects on the testis and prostate.

Animals↗
PubMed1985

Actions of enprofylline in the rat hippocampus.

Enprofylline is a novel xanthine with a low adenosine antagonistic potency, but with a good bronchodilator activity. In order to further elucidate its central nervous actions we have studied its effects in the rat hippocampus, both electrophysiologically and biochemically. Adenosine was found to depress evoked field excitatory post-synaptic potentials (EPSPs) in the rat hippocampus. The effect of adenosine was antagonized by theophylline but not by enprofylline. Both xanthines caused a slight increase per se of the field EPSP amplitude. Cyclic AMP accumulation in the rat hippocampus was stimulated by the adenosine analogue NECA, by isoprenaline and by noradrenaline in the presence of propranolol. The cyclic AMP accumulation induced by these agents was not significantly altered by omitting calcium. Enprofylline antagonized the effect of NECA and noradrenaline (after beta-blockade) but not that of isoprenaline. The IC50 of enprofylline against NECA was about 20 mumol X 1(-1). The inhibitory effect of enprofylline against NECA induced cyclic AMP accumulation was not affected by omitting calcium or by the calcium channel antagonist felodipine, but was decreased by the calmodulin inhibitor stelazine and the intracellular calcium chelator Quin-2. The results show that enprofylline is much more potent as an inhibitor of adenosine A2-receptor-mediated cyclic AMP accumulation than against adenosine A1-receptor-mediated inhibition of field EPSP. The difference may depend on a role of a special pool of calcium in the former response.

Adenosine↗
PubMed1985

Characterization of adenosine-induced respiratory depression in the preterm rabbit.

The respiratory performance was studied after intraperitoneal administration of the adenosine agonists N6-phenyl-isopropyl-adenosine (PIA) and adenosine-5-ethylcarboxamide to preterm (gestational age 29-30 days) newborn halothane-anesthetized rabbits. Both agonists induced marked hypoventilation and irregular breathing by decreases in the breathing frequency as well as the tidal volume. Expiratory time was markedly prolonged, resulting in a decrease in the respiratory duty cycle (inspiratory time/total cycle duration). Analysis using the occluded-breath technique revealed that the adenosine analogues altered the time setting of the expiratory (inspiratory) neuronal circuits and lowered the inspiratory off-switch level, while inspiratory drive and the bulbopontine setting of the inspiratory phase were unaltered. The ventilatory response to CO2 was blunted after both adenosine analogues studied. Theophylline almost completely reversed the hypoventilation and irregular breathing seen after PIA injection. It is concluded that activation of central nervous adenosine receptors induced a marked respiratory depression in the preterm rabbit. Furthermore, our data imply that an overactivity of central adenosine mechanisms may have a pathophysiological significance for the irregular breathing or apnea of prematurity sometimes seen in the human neonate.

Adenosine↗
PubMed1985

Prognostic significance of transrectal fine-needle aspiration biopsy findings after orchiectomy for carcinoma of the prostate.

In 48 patients with prostatic carcinoma two types of cell patterns were found at fine-needle aspiration biopsy at follow-up 6 and 12 months after orchiectomy: (1) unmodified carcinoma cells or (2) carcinoma cells with regressive changes. Objective clinical regression at 36 months was significantly more frequent in patients with regressively transformed cancer cells at 6 and/or 12 months than in patients with unmodified carcinoma cells: 73 and 32%, respectively. Ten percent of the patients with regressively transformed carcinoma cells and 41% of the patients with unmodified cancer cells died of prostatic carcinoma. The cytologic findings at 6 and/or 12 months after orchiectomy is thus of importance for predicting the prognosis.

Aged↗
PubMed1985

Direct inhibitory effects of natural and synthetic oestrogens on testosterone release from human testicular tissue in vitro.

Human testicular slices were incubated in vitro in order to examine the direct effects of natural and synthetic oestrogens on testosterone secretion. In the presence of human chorionic gonadotrophin (10 IU per ml), oestradiol-17 beta (1 or 10 micrograms per ml) and ethinyl oestradiol (0.1, 1 or 10 micrograms per ml) inhibited testosterone release into the media in a dose dependent manner. The addition of estramustine phosphate, estromustine, diethylstilboestrol or diethylstilboestrol diphosphate in comparable concentrations produced no significant effects on testosterone release.

Adenocarcinoma↗
PubMed1985

Alginate impression materials, dimensional stability and surface detail sharpness following treatment with disinfectant solutions.

A study was made of the influence of six dissimilar disinfectants on the dimensional stability and the surface detail sharpness of four alginate impression materials. All combinations of alginates and disinfectant solutions produced quite acceptable results as regards dimensional stability one hour after the impression material had been sprayed with the disinfectant. As regards surface detail sharpness one hour after this spraying certain combinations of alginates and disinfectant solutions showed better results than others. Immersion of the alginates in disinfectant solutions for one hour or more produced unacceptable changes.

Alginates↗
PubMed1984

Levels of adenosine and adenine nucleotides in slices of rat hippocampus.

ATP, ADP, AMP, IMP, adenosine, inosine and cyclic AMP were measured in slices of the rat hippocampus maintained in vitro. Immediately following cutting ATP was low (3.5 +/- 0.6 nmol/mg protein) and AMP high (8.6 +/- 0.9 nmol/mg), giving an energy charge of only 0.34 +/- 0.02. Over the next 90 min the energy charge gradually normalized (to 0.92 +/- 0.01), partly due to conversion of AMP to ATP, but mainly to breakdown to adenosine and other purines which were recovered in the incubation medium. Total purine content decreased from approximately 18 to 10 nmol/mg protein in the first hour following cutting. In slices from old rats the energy charge was lower 60 min following preparation than in younger rats, while cyclic AMP and adenosine levels were higher. The adenosine antagonist 8-phenyl-theophylline tended to enhance the recovery of responsiveness after preparation of the slices. Stimulation of excitatory afferent fibers at a frequency of 10 Hz for 5 min did not significantly alter the purine levels in brain slices, while hypoxia decreased the energy charge significantly and tended to increase adenosine levels. These changes occurred somewhat later than the fall in electrophysiological responsiveness. 8-Phenyl-theophylline was able to delay somewhat the decline in the amplitude of synaptic responses under hypoxic conditions. It is concluded that the viable part of the hippocampal slice, which accounts for about half of the tissue, has levels of adenine nucleotides and adenosine which are similar to those found in the intact rat brain. The return of electrophysiological function following slice preparation is paralleled by a normalization of the energy charge, the adenosine level and the concentration of cyclic AMP. The absence of electrophysiological activity following cutting, and the decreases in such responses following either prolonged afferent stimulation or hypoxia may be related to changes in purine concentration in the slice. Although adenosine accumulating in the slice may contribute to the depression of electrophysiological responses it is probably not the major factor responsible for the reduction in synaptic responsiveness.

Adenine Nucleotides↗
PubMed1984

Primary leiomyosarcoma of the vagina: a study of five cases.

The clinical and light and electron microscopic features of five cases of primary vaginal leiomyosarcoma, representing 2.9% of all vaginal malignancies registered at the Swedish Cancer Registry, are presented. The ages of the patients ranged from 31 to 69 years. The most common clinical presentation was an increasing mass and/or local tenderness. The tumor was located in the anterior wall in three cases and in the lateral wall in two. The size of the tumors ranged from 2 to over 10 cm. Four patients had tumors of high histologic malignancy grade and were all dead within 36 months. One patient had a tumor of low grade and is still alive 10 years after the initial excision. The ultrastructural observations of abundant myofilaments with focal elongated densities in primary paraffin-embedded material conform with the light microscopic diagnoses in all cases and indicate the usefulness and value of such material for electron microscopy in order to arrive at the diagnosis of leiomyosarcoma. The therapeutic and diagnostic aspects are discussed.

Adult↗
PubMed1984

Sexual function in prostatic cancer patients treated with radiotherapy, orchiectomy or oestrogens.

Sexual function in prostatic carcinoma patients was studied in 12 patients from each of three treatment groups: radiotherapy, orchiectomy and oestrogen treatment. Significant deterioration occurred in all groups. Although erectile potency was preserved in 9 of 12 patients treated with radiotherapy, 7 of these had a marked reduction in the frequency of sexual activity. Men subjected to orchiectomy or oestrogen treatment were seldom capable of having intercourse or of experiencing orgasm. However, oestrogen-treated men continued sexual activity with their partner more often than orchiectomised subjects. Patients receiving oestrogen treatment scored significantly higher for mental depression than those in the other two treatment groups.

Aged↗
PubMed1984

Transfer of terbutaline across the human placenta in late pregnancy.

Placental transfer of terbutaline was studied in 22 women in late pregnancy who were delivered by elective Caesarian section. A single i.v. dose of terbutaline (0.25 or 0.5 mg) was given at various times (13-295 min) before delivery. Immediately after delivery, one blood sample was drawn from the placental side of the umbilical vein and one from the mother's antecubital vein. By use of gas chromatography plus mass spectrometry terbutaline was assayed in maternal plasma and in plasma and whole blood from the umbilical vein. Plasma concentrations in the mothers (Cmv) were initially 7 micrograms/L, while the highest umbilical venous level ( Cuv ) recorded was 3.5 micrograms/L. The ratio Cuv /Cmv increased continuously during the time interval studied and approached unity after 2-3 h. The blood:plasma concentration ratio in venous umbilical blood was initially low. It reached unity after about 60 min, but increased steadily to about 1.5 during the time of study. Thus there was a continuous uptake of terbutaline from plasma into the erythrocytes. The slow in vivo equilibration of terbutaline between plasma and erythrocytes is probably due to the low lipophilicity of the drug. However, the latter characteristic did not seem to impede its diffusion across the placenta to any great degree.

Adult↗
PubMed1983

Binding capacity of testosterone-estradiol-binding globulin (TeBG), total and calculated unbound concentrations of testosterone in patients with carcinoma of the prostate treated with orchidectomy or estrogens.

Testosterone-estradiol-binding globulin (TeBG) binding capacity, total estradiol-17 beta and total testosterone were measured in patients with carcinoma of the prostate treated with orchidectomy or estrogens. Comparisons were made with a control group. There was a significant increase in TeBG binding capacity in the group treated with estrogens. Both orchidectomy and estrogen-treatment decreased total testosterone significantly and to the same degree. The concentration of free testosterone was calculated using a new method, and was found to be lower in orchidectomized and estrogen treated patients when compared with the control group. When the two groups under treatment were compared, the calculated free testosterone concentration was significantly lower in the estrogen treated group.

Adenocarcinoma↗