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Biomedical subjects

P Tuohimaa

Publications and source records attributed to P Tuohimaa.

At least 145 records · Page 8Linked to original sources
PubMed1977

Weight, stroma to gland ratio, and mitotic activity of the human hyperplastic prostate.

The growth of the hyperplastic prostate of 12 patients was studied with an in vitro 3H-thymidine labeling method. The prostates were weighed and the stroma to gland ratio was analyzed. The mitotic activity of the glandular epithelium averaged 0.36 per cent (+/- 0.06 SE). No mitotic activity was found in the stromal tissue. There was a positive correlation between the weight of the prostate and the labeling Index of the glandular epithelium. Thus, the prostatic hyperplasia of these patients appeared to be purely glandular in form. The stroma to gland ratio was 70 to 80 per cent. It was found that most of the glandular follicles were mitotically quiescent, and that the mitotic activity was concentrated in a few of the follices. The results indicate that the growth of the hyperplastic prostate is caused both by the mitotic activity (hyperplasia) of the glandular epithelium and by the stromal hypertrophy. Thus, in vitro assay of the mitotic activity of the prostatic biopsies can be used for the estimation of the weight of the hyperplastic prostate. The possible role of the stroma in regulation of the mitotic activity of the glandular epithelium has been discussed.

Aged↗
PubMed1976

Translation of avidin mRNA from chick oviduct in the oestrous mouse uterus.

Oestrogen-primed immature chicks were injected with 5.0 mg of progesterone. Twenty hours after progesterone avidin mRNA was isolated and purified by a method including an antibody precipitation of the avidin polysomes, phenol extraction and nitrocellulase trapping. A water solution of mRNA (1 mug) with [14C]amino acids was instilled into the uterine horn of oestrous or dioestrous mice. Saline and [14C]amino acids were injected into the opposite control uterine horn. Avidin was assayed by an antibody method. A clear-cut avidin synthesis was found in the oestrous uterus, whereas the dioestrous showed only a slight avidin synthesis. This suggest that there are no absolute species-specific factors required at the translational level of uterine protein synthesis and that the mammalian uterus can translate foreign hormone-specific proteins at a rate dependent on the endogenous protein synthesis.

Animals↗
PubMed1976

Control of the mitotic activity in the rat seminal vesicle by "chalone".

One month after castration male rats were injected daily with 2 X 50 mug of testosterone. Starting before the highest mitotic activity of seminal vesicles, 3 injections of normal seminal vesicle extract were given into the lumen at 3 h intervals. The contralateral seminal vesicle was injected with rat liver extract. Tritiated thymidine was given intravenously. The labelling index of the seminal vesicles was determined by means of radioautography. The crude supernatant of seminal vesicle was the most effective to inhibit the mitotic activity of the seminal vesicles. The decrease was on an average 34 per cent. The liver extract did not influence the mitotic activity. When the seminal vesicle extract was fractionated by Sephadex G-25, the largest fraction (M. W. greater than 3000) showed the highest inhibitory activity, whereas the smallest fraction (M. W. less than 1000) was ineffective. The inhibition of mitosis can also be induced by an unspecific factor, since pronase showed slight inhibitory action on seminal vesicle mitosis. However, the seminal vesicle extract had no inhibitory action on the epidermal mitotic activity.

Animals↗
PubMed1975

Immunofluorescence demonstration of avidin in the immature chick oviduct epithelium after progesterone.

Immature chicks were used for the experiments 1-2 days after hatching. A group of chicks were injected with 5 mg of progesterone and sacrificed 1 or 24 hr later. An other group of chicks were injected daily for 9 days with 5 mg of diethylstilbestrol and thereafter with single injection of progesterone. Cryostat sections were incubated with rabbit anti-avidin serum and with fluorescein labelled antirabbit globulin for fluorescence histochemistry. In the control animals no epithelial cells of the oviduct were fluorescence positive independently whether or not the animals were pretreated with diethylstilbestrol. One hour after administration of progesterone epithelial cells showed occasionally a slight synthesis of avidin. 24 hours after the injection of progesterone most, however never all, of the epithelial cells showed avidin in the apical part of the cell. The fluorescence reaction was clearly more intense if the animals were estrogen-primed. Diethylstilbestrol caused a differentiation of oviductal glands which were, however, only occasionally avidin positive after progesterone. These results suggest that primitive oviductal cells can produce avidin without preceding differentiation whereas estrogen causes a differentiation of new line of cells which have regularly lost their capacity of avidin synthesis after progesterone administration.

Animals↗
PubMed1975

Impaired 3H-testosterone uptake and metabolism in the accessory sex glands of diabetic castrated male rats.

The uptake and retention of 1,2-3H-testosterone in accessory sex glands, muscle and liver of streptozotocin diabetic castrated male rats, insulin-treated diabetic castrated rats and non-diabetic castrated control rats were studied at various time intervals after an intravenous injection. Diabetes reduced the retention of 3H-testosterone in the prostate, the preputial gland and the epididymis. Exogenous insulin slightly increased the retention of 3H-testosterone in these tissues of diabetic rats. No significant differences in the radioactivity in the rectus abdominis muscle, the coagulating glands and the seminal vesicles were found between the various experimental groups. Ventral prostate homogenates obtained from diabetic and control rats were incubated with 3H-testosterone in vitro. The steroids were extracted and thin-layer chromatographs were scanned for radioactivity. In prostatic homogenates taken from diabetic rats, testosterone transformation to dihydrotestosterone was reduced. The results indicate that the impaired function and androgen retention of the accessory sex glands of diabetic male rats is at least partly due to the reduced formation of dihydrotestosterone from testosterone.

Animals↗
PubMed1974

An improved micro-method for avidin assay.

A sensitive method for avidin assay was devised. Tritiated biotin is bound to avidin and this complex is then bound to bentonite. Radioactivity is converted into a gas form by combustion and counted in an automatic proportional counter with 55% efficiency and background of 3.7c.p.m. The sensitivity is 1-2ng of avidin.

Animals↗
PubMed1974

A simple method for the clinical determination of the mitotic activity of the human prostate in vitro.

Patients with a hyperplastic prostate were studied for the epithelial mitotic activity of adenomatous tissue by the (3)H-thymidine labelling method. A simple method in vitro was improved for biopsy samples. The mitotic activities obtained in vitro were compared with those obtained in vivo. The results show that the mitotic activity is not affected by the short incubation of the samples in Tyrode's balanced salt solution.

Aged↗
PubMed1973

Progesterone-dependent messenger RNA: heterospecific activity in vivo.

The action of progesterone in mediating the synthesis of avidin by the chick oviduct can be simulated by the intraoviductal instillation of nitrocellulose-trapped RNA from hormonally prepared chick or pigeon oviduct. Similarly, the pigeon oviduct synthesizes avidin in response to chick oviduct RNA. Thus, a heterospecific transfer of hormonal stimulation, through the transfer of progesterone-induced RNA, is demonstrated. The biological activity is lost after digestion by pancreatic ribonuclease. The 50-fold purification achieved by nitrocellulose chromatography of the total RNA preparation suggests that the activity resides in a messenger RNA fraction.

Animals↗