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Biomedical subjects

A O Martin

Publications and source records attributed to A O Martin.

72 records · Page 4Linked to original sources
PubMed1981

Parental chromosomal rearrangements associated with repetitive spontaneous abortions.

Parental chromosomal rearrangements represent a well-established cause of repetitive spontaneous abortions. However, the frequent of parental translocations varies widely in reported series, suggesting differences in ascertainment. For this reason a sample of individuals (120 women, 104 men) who had experienced spontaneous abortions but neither stillborn nor anomalous liveborn infants was investigated. Only one translocation was detected (0.4% of individuals). The relatively low frequency of translocations in this series of probably a reflection of not only lack of coexisting stillborn or anomalous infants but also the referral pattern in this unit that facilitates routine analysis of all couples experiencing repetitive abortions. In addition, one women showed a pericentric inversion.

Abortion, Habitual↗
PubMed1980

Stability of sex chromosome mosaicism.

In individuals with sex chromosome mosaicism the proportions of cell lines have been reported to change over time; however, purported changes have failed to show a consistent decrease or increase in any given cell line, normal or abnormal. We, therefore, investigated three mosaic individuals: two 45,X/46,X,i(Xq) and one 45,X/46,XX. We first initiated studies which verified that the proportion of various cell lines can be reliably (reproducibly) quantitated in lymphocytes of mosaic individuals, data which surprisingly were heretofore unavailable. Having established the ability to quantitate sex chromosome mosaicism, we initiated longitudinal studies. No significant differences in proportions of mosaic cell lines were observed in the three individuals studied over various time intervals. This stability was observed in individuals with high as well as lower proportions of 45,X cells. Further studies over longer periods and with other subjects are continuing, but our preliminary studies suggest mosaicism shows longitudinal stability, at least in adults. The practical clinical significance is that mosaicism can be reproducibly quantitated from a single lymphocyte culture, indicating that a single blood sample will generally suffice for most clinical studies.

Adolescent↗
PubMed1980

Pericentric X chromosome ascertained during antenatal diagnosis.

A pericentric inversion of an X chromosome [46,X,inv(X)(p11q28] with no detectable deletions was ascertained by amniocentesis for prenatal diagnosis in a 42-year-old woman. No defintive counsel could be offered as such an inversion had not been previously reported. At 1 year, the infant appears normal. These data and the review of other recently published karyotypes suggest an absence of a somatic position effect in the human X chromosome and possible biases of ascertainment or possible alternative karyotypic interpretations of some previously reported inv(X) cases.

Adult↗
PubMed1980

Cancer mortality in a human isolate.

Cancer mortality (1965--77) among 12,652 members of an inbred human religious isolate, the Hutterites, was compared with expectations based on mortality rates for the U.S. white population in 1970. Overall, Hutterites had significantly fewer deaths from cancer than expected (P < 0.01), due primarily to fewer lung cancers among males. Smoking is prohibited for this religious group. The most frequent types of cancers were leukemia and cancers of the digestive system, the prostate gland, and the female breast. Preliminary results suggest an association between recessive alleles and childhood leukemia. More stomach and rectal cancers were observed than expected, but differences were generally not significant. Familial aggregates of cancers of the stomach and breast are being investigated. The low frequency of cervical cancer is consistent with current evidence for an association of cervical cancer with early age at first intercourse and promiscuity, neither of which is characteristic of this population.

Canada↗
PubMed1979

Laminaria use in midtrimester abortions induced by intra-amniotic prostaglandin F2alpha with urea and intravenous oxytocin.

A laminaria tent was used as an adjunct during midtrimester abortion to attempt to shorten the injection-abortion interval without adversely affecting the frequency of infection, hemorrhage, failed abortion, or cervical laceration. Eighty patients, between 14 and 20 weeks' gestation and desiring pregnancy termination, were randomized into three groups. Abortion was initiated by an intra-amniotic infusion of 20 mg of prostaglandin F2alpha and 80 gm of hyperosmolar urea in Ringer's lactate (135 ml total volume), followed by oxytocin infused intravenously at 333 mU/min. Group I (N = 28) received no additional therapy; Group II (N = 23) had laminaria placed at the time of the abortifacient injection and removed 4 hours later; Group III (N = 29) had laminaria placed 4 hours prior to inejction and removed at the time of injection. The injection-abortion intervals in these three groups were 17.76, 20.80, and 12.96 hours, respectively. This study illustrates that a laminaria tent palced 4 hours prior to injection is significantly more effective than a laminaria tent placed at the time of injection, and produces a shorter mean injection-abortion interval than that in patients receiving no laminaria. Furthermore, laminaria augmentation results in no demonstrable increase in the frequency of serious complications.

Abortifacient Agents↗
PubMed1979

Localization of the nucleolar organizer by computer-aided analysis of a variant no. 21 in a human isolate.

A variant chromosome no. 21 consisting of two stalks and two satellites in tandem was detected during a survey of a human isolate. The variant segregated in three generations of a large kindred. One male had the variant no. 21, a metacentric Y, and a 47,XXY complement; however, no other evidence of chromosomal nondisjunction was found. Computer-aided analysis of sequentially stained variant no. 21 chromosomes indicated that silver-stained material corresponded to the proximal stalk region (as defined by Giemsa), but often covered both the distal stalk and satellite (also as defined by Giemsa). These data support the hypothesis that human nucleolar organizers are localized to the stalks of acrocentric chromosomes.

Azure Stains↗
PubMed1979

Analysis for amniotic fluid crystallization in second-trimester amniocentesis.

A potential complication of second-trimester amniocentesis for genetic indications is inadvertent needle insertion into the maternal bladder, resulting in aspiration of urine rather than amniotic fluid. Amniotic fluid forms a characteristic crystalline arborization pattern when allowed to air dry. We utilized this property of amniotic fluid to distinguish amniotic fluid from maternal urine. In 24 of 25 cases studied in a randomized blind fashion the crystalline arborization test correctly identified amniotic fluid, whereas none of the 25 urine samples showed this pattern. Our study indicates that the crystalline arborization test is reliable in distinguishing amniotic fluid from maternal urine during the second trimester of pregnancy.

Amniocentesis↗
PubMed1977

Cytogenetic nomenclature.

The advantage of a standardized nomenclature is apparent in any discipline. A standardized method for designating carbon molecules in steroid chemistry facilitates communication in endocrinology; consistent staging methods permit comparison of data in oncology. Likewise, a standardized method for designating cytogenetic data facilitates communications in genetics. Therefore, investigators should adhere to the official recommendations summarized in this report.

Azure Stains↗
PubMed1977

An autosomal dominant midline cleft syndrome resembling familial holoprosencephaly.

We have detected a previously unrecognized autosomal dominant syndrome characterized by: mental retardation, microcephaly; craniofacial anomalies including cleft lip and anterior cleft palate, hypotelorism and antimongoloid slant; skeletal anomalies, notably of the foot and spine; and chronic constipation. Despite similarities to familial holoprosencephaly, this disorder appears to be a distinct entity. Incomplete penetrance and variable expressivity accompany transmission of the abnormal allele through four generations of a large kindred. Three of the four affected males survived past 20 years of age; the fourth is an infant. All three affected females died very early in infancy.

Abnormalities, Multiple↗
PubMed1977

46,XX/47XX, + 14 mosaicism in a liveborn infant.

A liveborn infant with the complement 46,XX/47,XX, + 14 shared certain features in common with the following previously reported cases: (1) the one previously reported possible case of trisomy 14, (2) cases in which individuals had at least some portion of chromosome No. 14 in triplicate, and (3) cases of atypical D trisomy (Snodgrass category II). The common features include developmental retardation, wide flat nose with bulbous or wide tip, large mouth with turned down corners (some with protruding lips), short neck (some with redundant skin folds), low-set ears, retrognathia, digital anomalies (usually contractions and deviations), palatal anomalies, and cryptorchidism.

Child Development↗
PubMedDate not supplied

Implications of 'low' maternal serum alpha-fetoprotein levels: are maternal age risk criteria obsolete?

An association has been reported between 'low' maternal serum alpha-fetoprotein (MSAFP) and fetal chromosome abnormalities, notably Down syndrome. We suggest the predictive value be used for genetic counselling when a 'low' MSAFP is found, and present an illustrative risk table. It can also be seen that normal MSAFP in a woman may lower her age-related risks below that previously defined as 'high risk'. However, until good estimates of sensitivity and specificity are available from prospective, population based studies, patients should be told that any risk estimates are rough approximations. When good estimates are available, use of age risks alone may become obsolete.

Adult↗
PubMedDate not supplied

Cytogenetic analysis of a case of "13q- syndrome" (46,XX,del 13) using banding techniques.

Many chromosomal syndromes include ocular anomalies. In the del(13q) syndrome retinoblastoma, coloboma, and microphthalmia may be present. In the del(13q) case we report, the findings include colobomas and apparent microphthalmia, although the retinoblastoma sometimes associated with this condition was not observed. More precise descriptions of the del(13q) syndrome relative to the region deleted using improved banding techniques may: (1) increase the likelihood of accurate diagnosis, (2) enhance clinical predictions, and (3) possibly further clarify the genetic control over the development of the ocular system.

Abnormalities, Multiple↗