Arne Eide

Morphometric and autoradiographic studies on the growth of red and white axial muscle fibres in the shark Etmopterus spinax

SummaryThe axial muscle growth of the shark Etmopterus spinax has been studied by means of morphometry, slide histology and autoradiography from radioactive thymidine and amino acids. Comparisons have been made between the red and the white muscle fibres. While growing from 10 to 23 cm in length, the white muscle transverse sectional (ts) area increases 5.4 times, while the red area increases 3.7 times. The mean ts area of individual white fibres increases by 2.7, and the ts area of red fibres increases by 1.6. The number of white fibres does not increase significantly, while the red fibres increase slightly in number. Red fibres incorporate amino acids faster than the white fibres, and have a higher turnover rate. The myonuclei of the red fibres (satellite cell nuclei) incorporate thymidine more often than do those of white fibres, but the frequency of the satellite cells is simillar in the two fibre types. Mitoses are extremely rare in the myonuclei. The nucleocytoplasmic ratio is higher in the red than in the white fibres.

The effect of estradiol on the cell kinetics in the uterine and cervical epithelium of neonatal mice.

The effect of estradiol‐17β on the length of the various phases of the cell cycle was studied in the neonatal mouse uterine, and cervical epithelium. A double labelling method was used, and in addition labelled mitoses were counted. In the uterus proper, estradiol shortens the length of the total cell cycle, Tc, from 17‐9 hr to 15‐7 hr, and the duration of S phase, Ts, from 6–7 to 5‐1 hr 6 hr after estradiol treatment. 12 hr after estradiol treatment, Tc is shortened to 7‐4 hr and Ts to 4–5 hr. The shortening of Tc at 12 hr is mainly due to an effect on TG1, which is shortened from 8–55 hr in untreated animals to 1–8 hr in estradiol treated animals.

The effect of oestradiol on the DNA synthesis in neonatal mouse uterus and cervix

Summary(3H)-Thymidine autoradiography was used to study the DNA synthesis in the stroma and epithelium in the uterus proper and the uterine cervix of neonatal mice treated with oestradiol. It was found that in the epithelium of the uterus proper the DNA synthesis is stimulated between 6 and 12 h after injection of oestradiol and decreases again at 18 h. In the stroma of the uterus proper the DNA synthesis is increased 18 h after oestradiol injection.In the epithelium and stroma of the uterine cervix the DNA synthesis decreases from 5 h and is strongly depressed 18 h after oestradiol treatment.

Estradiol receptor in uterine tissue from neonatal mice. Influence by cyclic AMP.

Abstract The estradiol receptor in uterine tissue of neonatal mice has been studied. It is present neonatally and fulfills normal criteria as regards sedimentation behaviour, specificity etc. The influence of dibutyryl-cyclic AMP (db-cAMP) on receptor characteristics has been studied using sucrose gradient centrifugation and dry mount autoradiography. A consistent change in the cytosol receptor sedimentation behaviour is found when db-cAMP is included in the incubation medium of whole uteri preparations. A depression in the 8s receptor region is found simultaneously with an increase in the 4s region. There is no uptake of tritiated estradiol as seen in autoradiograms from organ cultures of neonatal uterine cervix preparations, when these have been cultured for 48 h. When db-cAMP is included in the incubation medium, a pronounced uptake is seen in the sections. Different possible points of action of cyclic AMP related to the findings described, are discussed.

Cultural Orientation and Alcohol-Type Preferences among Adolescents in Four Sociocultural Subgroups in Zimbabwe

A classroom survey among 3,061 secondary school students in four different socio-cultural subgroups was conducted in Zimbabwe. Structural equation modelling was applied to explore the relationship among sociodemographic variables, school childrens cultural orientation, and alcohol-type preferences. A model with local and global orientation as mediators explained 17% of the variance in reported use of imported alcohol types and 2.4% of the variance in use of traditional alcohol types. Global cultural orientation was positively associated with reported experimenting with, and use of, both imported and traditional alcohol types, whereas local orientation was negatively associated with use of imported alcohol types and positively associated with use of traditional alcohol types.

Cultural orientation and use of cannabis and inhalants among secondary school children in Zimbabwe

A survey among 3061 secondary school children in four provinces in Zimbabwe was conducted in 1994. In the present paper, the relationships between cultural and social factors and use of inhalants and cannabis are explored. Respondents were selected by means of a two-stage sample design, first based on a complete list of schools in the four provinces and subsequently on lists of students at the randomly selected schools. Stratification was based on the identification of four different sociocultural groups. Data collection followed standardised procedures and was conducted by a research team from University of Zimbabwe. Cultural orientation was operationalised by means of a Likert-type 14-item scale on choice of media, language and music. Exploratory principal component analysis revealed a two-factor solution, representing a global or Western cultural orientation and a local or Zimbabwean cultural orientation. Drug use by older siblings and best friends represented social factors. A combined model of cultural and social variables was subject to a multiple logistic regression analysis. Results revealed that the social variables and global cultural orientation were significantly associated with increased use of both drugs, whereas a local cultural orientation was found not to be associated with use of these substances. Findings are discussed in the light of historical and cultural factors.

Effects of 17β-estradiol on the distribution and activity of some oxydative enzymes of uterine and cervical epithelium in neonatal mice

SummaryThe following enzymes were studied histochemically in uterine and cervical epithelium from neonatal mice treated with 17β-estradiol for the first four days after birth: NADH-, NADPH-, succinate-, α-glycerophosphate-, lactate-, glucose-6-phosphate-, and 17β-OH-steroid dehydrogenases.It was demonstrated that estradiol administration had a marked influence on distribution and activity of several of the enzymes compared with the control animals. In cervix there was an increase of activity for most of the enzymes, especially in the apical parts of the epithelium cells. The uterine epithelium was also estradiol sensitive as regards most enzymes, and in the case of glucose-6-phosphate dehydrogenase there was a dramatic enhancement of reaction in the uterus of the experimental animals. The differences obtained between cervical and uterine epithelium are described.17β-OH-steroid dehydrogenase could not be detected histochemically in the present material.

Autoradiographic study on the localization of estradiol-17β in neonatal mouse uterus and cervix

SummaryThe uptake of 3H-estradiol-17β in the neonatal mouse uterus and cervix has been studied by an autoradiographic method. When the radio-active hormone is administered in vivo and in vitro, grains are found to be concentrated above the nuclei both in the uterine and cervical epithelium and stroma. Grain counts revealed that the nuclear concentration of grains is higher at 4 h than at 2 h after isotope injection. The cervical epithelium has a higher nuclear concentration than the uterine epithelium both in vivo and in vitro. In the stroma, this situation is reversed except after in vitro treatment of the tissues.In the cervix, more of the hormone seems to be located within the nucleus while in the uterus a higher proportion of the grains are found in the vicinity of the nuclear periphery.Although the nuclear concentration of grains is higher at 4 h than at 2 h, the number of grains above the sections is lower at 4 h. Both in vivo and in vitro, the number of grains is higher above the stromal than above the epithelial compartments of the uterus and cervix.Five days old animals showed the same labeling pattern. The differences in uptake and distribution of 3H-estradiol are discussed in relation to other known differences in the hormone responsiveness in these tissues.

The effect of cyclic adenosine 3′,5′-monophosphate on the uptake of estradiol by the neonatal mouse uterus

SummaryUterine tissue from neonatal mice was incubated in vitro at 0° C for 1 h in a medium containing 1×10-8 M 3H-estradiol with or without 1×10-4M dibutyryl cyclic AMP. In some incubations the temperature was raised to 37° C for 15 min after incubation in the cold, in others the temperature was kept at 0° C during this 15 min period. The tissue was frozen in liquid propane cooled in liquid nitrogen, sectioned at 2 or 4 microns, and autoradiograms prepared according to the dry-mount procedure. cAMP increases the cellular uptake of 3H-estradiol in uterine tissue. After rising the temperature to 37° C, grains appeared over the nuclei. cAMP at low temperature increased the cellular uptake of 3H-estradiol, but the grains were not associated with the nuclei. In the autoradiograms the grain number above the epithelium was markedly less than above the stroma.

A histochemical study of the oxidation of 17β-estradiol in human term placenta at different incubation conditions

SummaryThe present study deals with the histochemical demonstration of 17β-estradiol dehydrogenase in human term placenta using the polyvinyl alcohol method to reduce diffusion artefacts. Incubations took place with both NAD+ and NADP+ as coenzymes and at different pH values of the incubation medium. The NAD+ linked enzyme reaction showed a greater activity than the NADP+ linked, both in the trophoblast as well as in connective tissue. There were differences in staining intensity at the different pH values, and strongest reaction was observed using glycine-NaOH buffer pH 10 in the incubation medium. Owing to a non-enzymatically reduction of nitro blue tetrazolium by reduced NAD+, the demonstration of 17β-estradiol dehydrogenase is independent of diaphorase at this high pH. The findings are discussed in relation to data about “nothing dehydrogenase” and biochemically determined pH optima for the enzymatic reactions dealt with in this work.