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Biomedical subjects

L Tiepolo

Publications and source records attributed to L Tiepolo.

At least 37 records · Page 2Linked to original sources
PubMed1979

Multibranched chromosomes 1, 9, and 16 in a patient with combined IgA and IgE deficiency.

Instability of the centromeric region of chromosome 1 and multibranched configurations formed by different numbers and combinations of arms of chromosomes 1, 9, and 16 were found in cultured lymphocytes of a 12-year-old male with combined IgA and IgE deficiency. No chromosome abnormalities were found in fibroblast cultures from the patient or in blood cultures from his parents. A possible effect on the frequency of the abnormalities of the almost continuous antibiotic treatment received by the patient was found both in vivo and in vitro, but no abnormalities were found in blood cultures from control subjects who received similar treatment. Interphase association of chromosomes 1, 9, and 16 and a high frequency of interchanges among the centromeric regions of these chromosomes due to the presence of a fragile site is assumed to be the cause of the abnormalities.

Child↗
PubMed1979

Familial XX true hermaphroditism and the H-Y antigen.

Two 46,XX sibs, one of female, one of male gender, and both with ambiguous external genitalia and ovotestis, were H-Y positive. The mother was H-Y negative. It is assumed that the underlying mutation was transmitted by the father, resulting in an autosomal dominant mode of inheritance. The common origin and the nature of the mutation leading to XX sex reversal are discussed.

Adolescent↗
PubMed1978

BSu restriction of DNA from cases exhibiting sex-chromosome abnormalities.

The restriction endonuclease BSu, an isoschizomer of the enzyme HaeIII, cleaves human DNA to yield classes of fragments that are characteristic of the DNA of individuals having a Y chromosome. The fragments concerned are therefore diagnostic of the presence of Y-chromosome DNA and have been studied here with the intention of confirming the origin of various translocations thought, on other grounds, to involve the Y. The absence of the fragments from DNA of a case exhibiting absence of the fluorecent region of Yq suggests that the DNA concerned maps predominantly to Yq. Normal gender in the absence of the BSu fragments indicates that they do not function in sex determination.

Adult↗
PubMed1977

Nullisomy for the distal portion of Xp in a male child with a X/Y translocation.

An unbalanced X/Y translocation was found in a male child with malformed external genitalia and in his mother, who are respectively nullisomic and monosomic for the distal portion of Xp and have the translocated distal segment of Yq in excess. The loss of the distal portion of Xp is supposed to be the cause of the phenotypic abnormalities present in these subjects. The phenotype of our subjects is compared with those of the other cases of X/Y translocation described in the literature.

Dermatoglyphics↗
PubMed1977

Reduced phenotypic effect on partial trisomy 1q in a X/1 translocation.

A girl with psychomotor retardation and minor physical abnormalities, had an unbalanced X/1 translocation resulting in a partial trisomy 1q and partial monosomy for Xp. The four cases of partial trisomy for the distal segment of 1q reported in the literature showed a much more severely affected phenotype. In the present case the translocated X/1 chromosome is preferentially late replicating and there is spreading of late replication to the translocated 1q segment only in a minor proportion of the cells. The possibility of a non univocous correspondence between spreading of genetic inactivation and cytological spreading of late replication is discussed.

Child↗
PubMed1976

Localization of factors controlling spermatogenesis in the nonfluorescent portion of the human Y chromosome long arm.

A deletion of the Y chromosome at the distal portion of band q11 was found in 6 men with normal male habitus but with azoospermia. Five of them were found during a survey of 1170 subfertile males while the sixth was karyotyped because of slight bone abnormalities. These findings, together with a review of the literature, suggest that on the distal portion of the nonfluoresecent segment of the long arm of the Y, factors are located controlling spermatogenesis.

Adult↗
PubMed1976

Karotype, DNA replication and origin of sex chromosomes in Anopheles atroparvus.

Anopheles atroparvus has two pairs of autosomes similar in length and morphology and two sex chromosomes with equal, heterochromatic, late replicating long arms with homologous C-, G-, and Q-bands. The short arm of the Y is shorter than that of the X and both are euchromatic. The mean number of chiasmata per cell in the male is 3.2. During mitosis there is a high grade of somatic pairing but X and Y, which form a heteropycnotic mass in the interphase nucleus, have a differential behaviour. The chronology of DNA replication was studied in spermatogonia and brain cells by autoradiography. It is hypothesized that the present sex chromosomes of A. atroparvus evolved by accumulation of sex determining factors and gene deterioration resulting in heterochromatinization of the long arms, followed by structural rearrangements.--The homology of the two sex chromosomes requires limited dosage compensation which is achieved either as in Drosophila by modifier genes or by accumulation on the short arm of the X, only of female determining factors which do not require dosage compensation.

Animals↗
PubMed1975

Homologous bands on the long arms of the X and Y chromosomes of Anopheles atroparvus.

The long arms of the X and Y chromosomes of the mosquito Anopheles atroparvus (2n equals 6) are equal in length, synchronous in their late DNA replication and have homologous G AND Q bands. This indicates that differentiation of the two sex chromosomes was the consequence of a single deletion of an autosome to give the Y chromosome, not followed by the acquisition of differential heterochromatic blocks.

Animals↗