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J Csoknyay

Publications and source records attributed to J Csoknyay.

6 recordsLinked to original sources
PubMed1999

[Annual school and menarche rhythms (vacation-study)].

BACKGROUND: It has been hypothesized that the yearly menarche rhythm could be caused by the seasonal variation of photoperiod and temperature or by the annual distribution of the scholar vacation and study periods. AIM: To test the hypothesis that the distribution of study vacation periods is a condition that modifies the annual menarche rhythm. SUBJECTS AND METHODS: Two thousand ninety four school girls from Chile, 2,356 girls from Madras, India, 3,454 girls from Medellin, Colombia and 2,627 girls from Debrecen, Hungary, were studied. They were asked about the month of their menarche. Vacation months were considered those with more than 6 days of leave from school. RESULTS: The seasonal hypothesis was refuted because there were contradictions with the expected antithetical behavior in both hemispheres, there was a significant heterogeneity of the yearly menarche among girls from the same region, the expected cline of the menarche frequency variance from equator to poles was not observed, finding an antithetical cline instead and there was a significant heterogeneity among months of the same season. On the other hand, months with vacation periods coincided significantly with peaks of menarche, while study months had lower proportion of menarche (total binomial probability < 10(-6)). Girls whose month of menarche was the same as their month of birth, did not agree completely with the vacation-study hypothesis as the rest of the sample. CONCLUSIONS: Vacation periods influenced menarche rhythm. However, these periods coincide with most cultural events and this strong association needs further study to be considered causal. It is not possible to assume school stress as the main explanatory variable. Ontogenetic factors such as birth imprinting also can influence the menarche rhythm, as shown in girls whose month of menarche coincided with their month of birth.

Adolescent↗
PubMed1996

New evidence of non seasonal factors in the menarche rhythm.

The phylogenetic, ontogenetic and seasonal hypotheses on the annual periodicity of menarche were tested. Data from European, Asian (Caucasian, Mongolian and Caucaso-Mongolian people from the northern hemisphere) and Chilean (Caucaso-Amerindian from the southern hemisphere) populations were compared with data from Hungary (Caucaso-Mongolian Europeans from a northern temperature zone) and Madras, India (a complex ethnically originated people from a tropical northern area). Chileans were compared with those Caucaso-Mongolian people because Amerindians belong also to the Mongolian group. Hungarian girls showed peaks of menarche in the month of January (winter), June, July and August (summer), in contradiction with most European Caucasians who showed peaks only in winter months; and in agreement with Finns who showed both peaks. Indian girls had peaks in April, May and June (summer) and more extreme peaks and troughs than the Finnish girls (from a temperature arctic zone). These findings do not agree with the seasonal hypothesis, but they do with the phylogenetic hypothesis. Indian girls had a peak of menarche in the same month of birth and the arrangement of data according to the gestational-menarche coincidence showed a significant heterogeneity for the monthly peaks of menarche; thus, the ontogenetic hypothesis was also supported.

Adolescent↗
PubMed1991

[Sexual development: development of secondary sex characteristics--Tanner stages 25 years later].

In a longitudinal study the british pediatrician J.M. Tanner evaluated the development of breasts (thelarche), of pubic hairs (pubarche) and age of menarche. In Hungary we did a similar evaluation in 680 girls in the years 1980 to 1986. Comparing these data in a cross-sectional study with similar data from Münster we named the results central-european study. The results are similar the Tanner ones exceptionally the duration of breast development, which was shorter than in the hitherto published longitudinal studies. Mean age of menarche in our study was 12.5 years compared with 13.5 years in the former ones. This is not a confirmation to acceleration of puberty, because in other countries age of menarche was stabile. Additionally, to thelarche, pubarche and menarche we collected data about axillarche.

Adolescent↗
PubMed1988

Ovarian function after the menarche and hormonal contraception.

The aim of the study was to determine the date of regular ovulation after the menarche to better understand the physiology of female adolescence, especially as it pertains to the use of hormonal contraception. Early morning urine samples were collected from 51 girls in the perimenarche for 9 weeks semi-annually during 2 years. Estrone- and pregnanediol-3-glucuronide values were determined. Cycles lasting 35-40 days at the onset of menses shortened to 28 days after the 23rd-25th cycle. Menses reached a 5.0-5.5 day average length at about the same time. After the 20th cycle, ovulation could be demonstrated in more than 50% of the study patients. Using a scoring system, regular ovulation could be expected on the basis of somatic data with scores of greater than 16. Hormonal contraception may be prescribed 2 years after the menarche, based on scores of greater than 16 and ovulation proven be hormonal cytology and basal body temperature.

Adolescent↗
PubMed1986

Ovarian function immediately after the menarche.

Estrone and pregnanediol-glucuronide values of early morning urine samples collected from young girls in the perimenarche were determined by radioimmunological technique. A total of 58 teenage girls started collecting urine samples after their menarche at various times. Of these, 9 completed collection within 100 days of the onset of the first menstrual period. In 3 cases, insignificant changes in estrone and pregnanediol levels were noted. Normal estrone values were found in 3 cases together with pregnanediol levels suggestive of ovulation. In 2 further cases the possibility of ovulation without follicular release was suggested. The results indicate that ovarian activity is unpredictable immediately following the menarche. Between very low levels of sexual steroid hormone production and those normally observed in adult females, all transitional values could be found.

Adolescent↗