Search PubMed⌕ Search

Biomedical subjects

D C Page

Publications and source records attributed to D C Page.

118 records · Page 7Linked to original sources
PubMedDate not supplied

Chromosome Y-specific DNA in related human XX males.

Human 'XX males' are sterile males whose chromosomes seem to be those of a normal female. About 1 in 20,000 males has a 46, XX karyotype, and most cases are sporadic, that is, they are without familial clustering. It has long been argued that maleness in XX males may result from the undetected presence of a small, testis-determining fragment of the Y chromosome, and there is strong evidence for this in sporadically occurring XX males. Indeed, the genomes of three of four sporadic XX males tested were found to contain certain Y-specific DNA sequences. A pedigree in which three XX males occur has been interpreted as being consistent with autosomal recessive inheritance of maleness, and it has been argued that the basis of XX maleness in this family is fundamentally different from that in the sporadic cases. However, we report here that these related XX males, like the sporadic cases, contain portions of the Y chromosome. The portion of the Y chromosome present in one of the three XX males differs from that present in the other two.

Chromosome Mapping↗
PubMedDate not supplied

Linkage of an X-chromosome cleft palate gene.

Many congenital malformations, such as cleft palate and neural tube defects, have a multifactorial origin involving both environmental and genetic factors. Conditions such as these may be exclusively monogenic, polygenic or environmental, but in most cases both genetic and environmental factors are involved. This study describes the sub-chromosomal localization of a single gene defect causing cleft palate and ankyloglossia (tongue-tied) in a large Icelandic family. This defect is a model for the analysis of other neural-crest malformations that show a more complex multifactorial inheritance pattern.

Cleft Palate↗
PubMedDate not supplied

Valuable libraries.

Explore the source record for details and available documents.

Cloning, Molecular↗
PubMedDate not supplied

Separation of the genetic loci for the H-Y antigen and for testis determination on human Y chromosome.

The mammalian Y chromosome encodes a testis-determining factor (termed TDF in the human), a master regulator of sex differentiation. Embryos with a Y chromosome develop testes and become males whereas embryos lacking a Y chromosome develop ovaries and become females. Expression of H-Y, a minor histocompatibility antigen, may also be controlled by a gene on the Y chromosome, and it has been proposed that this antigen is the testis-determining factor. We have tested the postulated identity of H-Y and TDF in the human. H-Y typing with T cells was carried out on a series of sex-reversed humans (XX males and XY females), each shown by DNA hybridization to carry part but not all of the Y chromosome. This deletion analysis maps the gene for H-Y to the long arm or centromeric region of the human Y chromosome, far from the TDF locus, which maps to the distal short arm.

Chromosome Deletion↗
PubMedDate not supplied

Exchange of terminal portions of X- and Y-chromosomal short arms in human XX males.

In most human 'XX males', DNA sequences normally found on Yp, the short arm of the Y chromosome, are present on Xp, the short arm of the X chromosome. To establish whether this transfer involves a terminal portion of Yp, and whether a terminal portion of Xp is lost in the process, we followed the inheritance of pseudoautosomal restriction fragment length polymorphisms in two XX-male families. One XX male apparently inherited the entire pseudoautosomal region of his father's Y chromosome and no part of the pseudoautosomal region of his father's X chromosome. The second XX male also inherited the entire pseudoautosomal region of his father's Y, but in addition inherited a proximal portion of the pseudoautosomal region of his father's X. These findings argue that XX males result from the transfer of a terminal portion of Yp onto Xp in exchange for a terminal portion of Xp (ref. 7). This implies that the testis-determining factor gene (TDF) maps distally in the strictly sex-linked portion of Yp, near the pseudoautosomal domain. The XX males described here appear to result from single (and, at least in the second case, unequal) crossovers proximal to the pseudoautosomal region on Yp and proximal to or within the pseudoautosomal region on Xp.

Alleles↗
PubMedDate not supplied

Sequences homologous to ZFY, a candidate human sex-determining gene, are autosomal in marsupials.

Sexual differentiation in placental mammals results from the action of a testis-determining gene encoded by the Y chromosome. This gene causes the indifferent gonad to develop as a testis, thereby initiating a hormonal cascade which produces a male phenotype. Recently, a candidate for the testis-determining gene (ZFY, Y-borne zinc-finger protein) has been cloned. The ZFY probe detects a male-specific (Y-linked) sequence in DNA from a range of eutherian mammals, as well as an X-linked sequence (ZFX) which maps to the human X chromosome. In marsupials it is also the Y chromosome that seems to determine the fate of the gonad, but not all sexual dimorphisms. Using the ZFY probe we find, surprisingly, that the ZFY homologous sequences are not on either the X or the Y chromosome in marsupials, but map to the autosomes. This implies ZFY is not the primary sex-determining gene in marsupials. Either the genetic pathways of sex determination in marsupials and eutherians differ, or they are identical and ZFY is not the primary signal in human sex determination.

Animals↗
PubMedDate not supplied

Molecular evidence of Y-autosomal translocations in owl monkeys.

Probe pDP1007, which contains highly conserved DNA sequences from the sex-determining region of the human Y chromosome, cross-hybridized with owl monkey EcoRI restriction fragments of 1.8 kb and 6.6 kb. Southern transfer analysis of owl monkey (karyotype VI)--rodent somatic cell hybrids localized the 1.8-kb fragment on the owl monkey X chromosome and the 6.6-kb fragment, which is male specific, on chromosome 14/Y. Regional in situ chromosome mapping of pDP1007 revealed specific sites of hybridization: the distal short arm of the X chromosome of karyotypes IV, VI, and VII; the small metacentric Y of karyotype IV; the C-band positive region on the short arm of chromosome 17/Y (karyotype VII); and the C-band positive region on the long arm of chromosome 14/Y (karyotype VI). These molecular findings reinforce cytological evidence that Y-chromosomal material has been transferred to autosomes 14 and 17 in owl monkeys of karyotypes VI and VII, respectively, in which there are no independently segregating Y chromosomes.

Animals↗
PubMedDate not supplied

The new dental-medical renaissance. Medically efficacious functional jaw orthopedics.

Functional Jaw Orthopedics (FJO) is medically efficacious, exceptionally unique and unequaled in speed of a cure for a number of very common medical conditions currently only "managed" by modern medicine. This publication combines scientific citations and case presentations to show how and why dentists who advocate and provide early FJO treatment will lead a New Dental-Medical Renaissance into some of the most profound areas of medicine. Nocturnal enuresis (chronic bed-wetting) otitis media (ear infections), cor pulmonare, cognitive thought, vision, hearing, cardio-pulmonary dysfunction, and myocardial infarction have FJO dental-medical relationships. Early FJO treatment fulfills the ADA Code of Ethics which "calls upon dentists to follow high ethical standards which have the benefit of the patient as their primary goal: Do No Harm and Do Good."

Airway Obstruction↗
PubMedDate not supplied

The orthodontic shift towards functional jaw orthopedics.

FJO treatment is exceptionally unique and differs dramatically from traditional orthodontics. Parents are demanding earlier treatment, less bicuspid extractions, and broader smiles. A national trend towards FJO treatment methods will continue because FJO treatment has been shown to be medically effective for a number of common human disorders. Progressive dentists who provide cutting edge FJO therapy are uniquely positioned to impact human development and general health starting at birth, in ways yet to be charted. Early FJO treatment fulfills the ADA Code of Ethics which "calls upon dentists to follow high ethical standards which have the benefit of the patient as their primary goal: Do No Harm and Do Good."

Humans↗