Biomedical subjects

R Zamir

Publications and source records attributed to R Zamir.

58 records · Page 4Linked to original sources

PubMedDate not supplied

Role of children's sex in mixed mother-child lymphocyte culture reactivity.

One-way mixed mother-child lymphocyte cultures (MMCLC) 4 to 20 years after the last delivery were studied with maternal responding and children's or fathers' stimulating cells (MMFLC) in 14 multiple child families with 18 sons and 20 daughters. HLA antigen typing locus A, B, DR was performed for all family members. As reported previously for newborn cells, a significantly increased maternal response could be observed in MMCLC with male as compared to female children's stimulating cells. Although the number of cases studied was small, it seems that the increased stimulating effect of male children's cells could also be observed when MMCLC values from children of different sex, and identical A,B,DR haplotypes were compared. In contrast to this, A,B,DR haploidentical children of the same sex seem to have a similar stimulating effect on the maternal response in MMCLC. The results suggest that male children's Y-chromosome-correlated minor histocompatibility antigens may additionally stimulate the maternal immune response in MMCLC.

Birth Order↗

PubMedDate not supplied

Differential effect of advanced maternal age on prenatal diagnosis of trisomies 13, 18 and 21.

Nondisjunction associated with advanced maternal age, a well-established factor in the etiology of autosomal trisomy, should equally affect all chromosomes. In this study we evaluate the association of advanced maternal age with the occurrence of potentially viable autosomal trisomies (13, 18 and 21). 275 aneuploid pregnancies were ascertained prenatally and were grouped according to chromosome anomaly diagnosed. Mean maternal age was significantly younger (p = 0.009) in pregnancies affected by trisomy 13 than in pregnancies with trisomy 21. An intermediate mean maternal age was observed in pregnancies affected by trisomy 18. Our study shows a trend of the more severe, but potentially viable, autosomal trisomies to be diagnosed at younger maternal age. This may substantiate the 'relaxed selection hypothesis' proposed to explain the association of aneuploid conceptions with advanced maternal age.

Adult↗

PubMedDate not supplied

Sonographic nuchal markers for Down syndrome are more common but less ominous in gestations with a male fetus.

OBJECTIVE: A change in the normal male-to-female ratio has been reported in some autosomal trisomies (i.e., trisomy 21 or trisomy 18). The objective of the present study was to evaluate the male-to-female ratio in pregnancies with sonographic nuchal markers for Down syndrome. METHODS: The results of amniocenteses performed for isolated nuchal markers for Down syndrome were grouped by fetal sex and by maternal age. The male-to-female ratio in normal and trisomic gestations was compared. RESULTS: 584 fetal karyotypes were available for analysis. A significantly higher male-to-female ratio was observed. More affected gestations were observed in association with a female fetus. These differences were mainly attributed to the group of patients younger than 35 years that represents more than 80% of our study population. No difference was observed in pregnancies of patients older than 35 years of age. CONCLUSIONS: In patients younger than 35 years, sonographic nuchal markers for Down syndrome are more frequent (but apparently less ominous) in gestations with a male fetus. If the gender is known, counseling can be modified to include such differential risks.

Adult↗

PubMedDate not supplied

Familial varicocele.

Described are two families in each of which two young males had varicocele. HLA-A, B, C and D5R antigen studies were performed in one family but no genetic factors could be determined. In a review of several large series of patients with varicocele we found no mention of familial occurrence. Although the linkage between adolescent varicocele and spermatogenic dysfunction is still debatable, it is concluded from our experience that it is worthwhile examining other male members of families of affected adolescents or children but that expensive invasive studies are not warranted.

Adolescent↗