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Biomedical subjects

J del Mazo

Publications and source records attributed to J del Mazo.

31 records · Page 2Linked to original sources
PubMed1988

Identification of centromere proteins in different mammalian cells.

The characterization of centromeric proteins is facilitated using anti-centromere antibodies present in the sera of patients with the CREST variant of scleroderma. We have employed these sera to determine whether or not those proteins are present in different mammalian species, as well as to study their tissue distribution. Here, we describe the immunofluorescent pattern and the proteins recognized by CREST sera in dividing and resting cells from mouse, rat, swine, hamster, rabbit, and man. In nuclear preparations from cultured cells, thymocytes and spermatozoa from these species, the antigens recognized by CREST sera are proteins of 18 to 20 kDa in all species tested, except in rat. Additionally, two peptides of 80 and 140 kDa were observed in human preparations. In contrast, a 50 kDa peptide is the primary protein detected by the sera in rat nuclei.

Animals↗
PubMed1987

Centromeric proteins recognized by CREST sera and meiotic chromosome segregation.

Analysis of the peptides recognized by CREST sera was carried out in different mouse tissues and cells, including spermatozoa. In all cases, a polypeptide of Mr = 18,000 was recognized by the sera and occasionally two other proteins of Mr = 80,000 and Mr = 140,000 were observed after immunoblotting of nuclear proteins. In both early and late spermatids, centromeric staining was observed after incubation and immunofluorescence with CREST sera. After detergent treatment, it was even possible to detect centromeric staining in mature spermatozoa. In spermatid cells, the immunofluorescent pattern presented a binomial distribution of the number of fluorescent spots, with a mean value around half of the haploid number of chromosomes. Since this pattern is the result of chromosome segregation after meiosis II, our data suggest that this centromeric peptide is not directly implicated in the chromosome segregation process. On the other hand, the distribution of spots after immunofluorescence suggests a different organization of centromeric components in meiosis I and meiosis II.

Animals↗
PubMed1986

Multistranded organization of the lateral elements of the synaptonemal complex in the rat and mouse.

Using electron microscopy, we have analyzed the structure of the lateral elements (LEs) of the synaptonemal complex (SC) in rat and mouse spermatocytes under different spreading conditions. Our observations indicate that in nearly 50% of the cells it is possible to detect more than one structural component of the LEs in the XY pair. When the same spreading conditions are used, the structure of the LEs is not the same in the autosomes and the XY pair. Moreover, the correlation between different spreading conditions and the detection of more than one sublateral element (subLE) was different in pachytene and diplotene spreads; it also varied depending on the species and meiotic stage. Our study supports the notion that the LEs of the SC are multistranded.

Animals↗
PubMed1986

Centromere pattern in different mouse seminiferous tubule cells.

Centromere arrangement in different mouse seminiferous tubule cells was analyzed using an anticentromere antiserum from a patient with the CREST syndrome of scleroderma. A peptide of 18 kd was recognized by this serum on immunoblotting of mouse nuclear proteins from seminiferous tubule cells. In the cells studied by immunofluorescence, different patterns of centromere arrangement were observed. A speckled arrangement of centromeres was found in spermatogonia, double spots corresponding to meiotic bivalents were found in pachytene cells, and clusters of a haploid numer of centromeres were found in early and acrosome phase spermatids. In Sertoli cells, only three centromeric spots were detected, corresponding to the nucleolar organizer chromosome pairs. A relationship between the functional stage of the cell and the arrangement of and conformational changes in the centromeres is considered.

Animals↗
PubMed1982

Trisomy 21: origin of non-disjunction.

The Q-band heteromorphisms of chromosome 21 were used in a sample of 48 families with a Down's syndrome child to evaluate the origin of non-disjunction. The parental origin and the meiotic error were determined in 27 families, and in eight families only partial information was obtained. Paternal and maternal origin of non-disjunction was in a 1:3 ratio. Failures were five times more frequent in first than in second meiotic division in both sexes. The mean parental age and environmental factors in relation to the origin of the anomaly are discussed. Our results are compared with those obtained previously in similar studies by other authors.

Chromosomes, Human, 21-22 and Y↗
PubMed1980

[Balanced translocation 8:10 and adrenogenital syndrome. Family study (author's transl)].

An 8:10 translocation was found in a 15-day-old female child affected with adrenogenital syndrome. Some other members of the family also showed the same chromosomal anomaly. By G-, Q- and T-banding, break and fusion points were determined at the level of 8q21 and 10q24 bands. The hormone and enzymatic tests carried out in all the members of the family revealed a 21-hydroxylase deficiency only in the proposita. Possible relationship between the manifestation of syndrome and chromosomal anomaly are discussed.

Adrenal Hyperplasia, Congenital↗
PubMed1979

Trisomy 10p due to a de novo t(10p;13p).

A new case of trisomy 10p has been identified by means of the GTG-banding technique. The patient is a female child carrying a sporadic translocation, t(10;13)(p11;p11), and affected by microsomatia and microcephaly with facial dysmorphia, retarded growth, weight gain, and psychomotor development, and bilateral talipes.

Child, Preschool↗
PubMed1979

Maternal origin of a trisomy 7 in a spontaneous abortus.

Trisomy 7 has been determined in a spontaneous abortus by QFQ- and GTG-banding. The comparative study by photodensitometry of the polymorphism of the 7p14 band in GTG-banding, in both the abortus and its parents, has shown that in this case the origin of the trisomy is in the nondisjunction of the second maternal meiotic division. The factors that may have affected the process are analyzed.

Abortion, Spontaneous↗
PubMed1979

["Free" 9p trisomy in a male child with severe mental retardation (author's transl)].

A new case of free 9p trisomy is described. The GTG banding technique and the Giemsa-11 method showed that the extra chromosome comprised precisely the 9pter leads to q12 segment. The carrier is an eleven-year-old male child with typical facial features: globulous nose, antimongoloid slant of palpebral fissures, downward turning of mouth angels and winged ears, severe mental retardation particularly regarding language and characteristic dermatoglyphics.

Child↗
PubMed1978

Partial deletion of 4p16 band in a ring chromosome and Wolf Syndrome.

A new case of ring chromosome 4 in a 2-day-old female child with multiple malformations is described. By means of the GTG-banding technique, a karyotype 46,XX,r(4), (p16 leads to q35) was determined. The characteristics of the child's karyotype and the relationship with the structure of the chromosome, especially the location of the deletion that produces the syndrome, are compared with previous reports.

Abnormalities, Multiple↗
PubMed1977

Human triploid embryo: cytogenetic and anatomopathologic study.

A cytogenetic and anatomopathologic study of an embryo of 24 mm crown-rump length showing pure triploidy (69,XXY) is reported. Anomalies such as unilateral genitourinary agenesia, aortic alterations, defects in cerebral development, and anomalies of the chorionic villi were detected.

Aneuploidy↗