The hypothalamo-neurohypophyseal complex (HNC) of the fetal guinea pig shows a dramatic increase in its content of vasopressin and neurophysin between the 40th and 55th days of gestation. The values for radioimmunoassayable hormone and binding protein are at day 40, 2 milliunits and less than 0.1 microgram; and at day 55, about 100 milliunits and 10 micrograms, respectively. Isotope incorporation experiments with organ cultures of the fetal HNC taken prior to the 35th day of gestation added additional confirmation of the inability of the hypothalamic neurosecretory cells to synthesize vasopressin or neurophysin at this time. However, by the 45th day, similar organ cultures show a vigorous incorporation of labeled amino acids into both hormone and binding protein. Furthermore, the HNC of the 45-day-old fetus apparently contains a factor that stimulates specifically the biosynthesis of vasopressin and neurophysin in HNC cultures from the adult guinea pig. This factor is not detectable in either cortex or liver of the 45-day-old fetus or in the fetal HNC taken prior to or after the period of exponential rise (40th to 55th days) of hormone and binding protein.

Amino Acids↗

PubMed1975

Guinea pig neurophysin: isolation, developmental aspects, biosynthesis in organ culture.

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Amino Acids↗

PubMed1975

[Pulsecytophotometric analysis of cervical cells of postmenopausal women (author's transl)].

49 suspensions with cells of the cervix uteri exclusively taken from postmenopausal women were analysed with the pulsecytophotometer. 7 of these cases had an histologically verified invasive cancer of the cervix uteri. There were no false negative results, the percentage of false positive measurements was about 30%. This good result may arise from selecting the cell material analized exclusively from postmenopausal patients and the choice of mathematical model for histogram interpretation, which has been constructed analogously to the cycle of mitosis of cells. Comparing the different methods of preparation of the suspensions the standard procedure (RNase, pepsin, ultrasonic) before staining with ethidium bromide seems to be the best one.

Automation↗

PubMed1975

[Cytofotometrically Determined DNA-pattern of premalignant cases of dysplasia of the cervix uteri. Contribution to the problem of morphologic definition and clinical sigificance of these lesions (author's transl)].

24 cases of probably benign and precancerous epithelial lesions of the cervix uteri were analysed cytofotometrically. The specimens were stained after the method of Feulgen. Benign epithelial changes for instance metaplasia, regenerating epithelium, atrophic and parakeratotic epithelium, basal cell hyperplasia and cervix epithelium irritated by inflammation, had normal diploid DNA-pattern. On the contrary premalignant dysplasia of all stages show an aneuploid DNA-content in every case. The cases of dysplasia had no diploid mode, an atypical proliferation with polyploidisation of an atypical way, DNA-stemlines and a broad scattering of DNA-values. Carcinoma in situ had a similar DNA-content. These data confirm the hypothesis premalignant dyplasia is a reality between normal cervical epithelium and carcinoma in situ. For now only severe grades of dysplasia have been treated by operation (i. e. conisation, hystectomy) not the low grade cases of dysplasia. With regard to DNA-histograms of dysplasia of all grades this seems to be unjustified.

Adult↗

PubMed1975

The hypothalamo-neurohypophysial complex in organ culture: morphologic and biochemical characteristics.

Organ cultures of the guinea pig hypothalamo-neurohypophysial complex could be maintained for periods as long as 3 weeks. Morphological studies using conventional light microscopy as well as electron microscopy indicate that neurosecretory cells remain viable during this time. Biochemical studies show that the capability of the cultures to synthesize a normal spectrum of cellular RNA species is impaired during the initial day in culture, but that this capability is restored after 4-5 days. Similarly, protein synthesis proceeds at low levels during initial days of culture, but increases after 5 days. These phenomena appear to be independent of changes in the specific radioactivity of precursor pools and were also observed when outgrowth of non-neuronal cells is inhibited with fluorodeoxyuridine. The content of vasopressin, a product of a specific class of neurosecretory neurons, was found to decrease in the posterior pituitary during 7 - 10 days in culture by 50-70 percent; the levels then plateaued and were maintained for up to 3 weeks. The hypothalamic content of the hormone was relatively constant throughout the culture period. Of most importance was the demonstration that the organ cultures were capable of vasopressin biosynthesis. This capability paralleled the biosynthetic activity of RNA and gross protein metabolism in that there was an initial refractory period of several days duration.

Animals↗

PubMed1975

The hypothalamo-neurohypophysial complex in organ culture: effects of metabolic inhibitors, biologic and pharmacologic agents.

Organ cultures of the guinea pig hypothalamo-neurohypophysial complex synthesize the octapeptide hormone, vasopressin, a specific product of the neurosecretory cells of the supraoptic nucleus. Inhibitors of both protein and RNA synthesis (cycloheximide and bromotubercidin respectively) were found to block vasopressin biosynthesis. In the presence of bromotubercidin, the apparent half-time of decline in the rate of hormone biosynthesis was about 28 h. Colchicine inhibited the distal transport of vasopressin into the posterior pituitary. Ultrastructural studies on colchicine-treated cultures indicated the neuronal stalks were intact and that neurotubules were still present. The narcotic drug, levorphanol at 10-7 M and 10-9 M was found to inhibit RNA synthesis by 20 percent. At these concentrations it had no demonstrable effect on vasopressin synthesis. Cultures established from animals that had been rendered tolerant to narcotics also had no observable alterations in vasopressin biosynthesis, although the initial pituitary vasopressin content of these cultures was reduced by about 35 percent. Various pharmacologic and biologic compounds were tested for their effects on vasopressin biosynthesis in organ cultures. Dibutyryl cyclic AMP, estradiol-17beta, nicotine, nerve growth factor (NGF), and pineal extract all had no effects under the present experimental regimen. Medium conditioned by the presence of fetal hypothalami of 40-55 days gestation produced a 2-4 fold increase in vasopressin biosynthesis in cultures established from adult animals. Medium conditioned by fetal cerebral cortex, liver, or hypothalamic tissue from fetuses of less than 33 days gestation did not have this stimulatory effect.

Antibiotics, Antineoplastic↗

PubMed1975