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Biomedical subjects

O Mutchinick

Publications and source records attributed to O Mutchinick.

At least 19 recordsLinked to original sources
PubMed1992

Absence of limbs and gross body wall defects: an epidemiological study of related rare malformation conditions.

The study is based on almost 10 million births and reports on 215 infants with two unusual malformations: amelia and gross body wall defect. Amelia without body wall defect was present in 116 cases, 67 had body wall defects without amelia, and 32 had both. The total rate was 2.2 per 100,000 births. The infants were divided into five mutually exclusive groups. There were 40 infants (0.4 per 100,000) with agenesis of the body stalk, 18 with amelia and other types of gross body wall defects (0.2 per 100,000), 56 with amelia and malformations other than gross body wall defects (0.6 per 100,000), 41 with amelia (with or without other limb reduction defects) but no nonlimb malformations (0.4 per 100,000), and 60 infants with gross body wall defects of a type other than agenesis of body stalk and without amelia (0.6 per 100,000). A weak trend of decreasing prevalence of these malformations was found during the observation period. Infants with agenesis of the body stalk and infants with amelia combined with other types of gross body wall defects occurred at an increased rate in infants of young women. This maternal age effect is also found with gastroschisis, but not with omphalocele, and may indicate etiological or pathogenetic similarities between gastroschisis and the two former groups of defect. In infants with amelia, additional limb reduction defects could be of any type: transverse, longitudinal, or intercalary. Therefore, amelia may be the end result of different types of disturbances of limb morphogenesis. There was an increased rate of twinning. The relationship with amniotic band syndrome is discussed.

Abdominal Muscles↗
PubMed1992

An international case-control study on hypospadias. The problem with variability and the beauty of diversity.

The paper describes problems and advantages in an international cooperative study of a case-control design, aimed at investigating the possible association between exogenous hormones and hypospadias. The varying degrees of the ascertainment of specific exposures and risk factors, in spite of the use of a standardized questionnaire is illustrated. Definite support for the existence of recall or interviewer bias is presented. On the other hand, the multipopulation design offers possibilities to make use of the diversity of the populations: differences in reproductive patterns and in specific exposures such as drug use, smoking and maternal occupation.

Bias↗
PubMed1992

The cyclops and the mermaid: an epidemiological study of two types of rare malformation.

Infants with cyclopia or sirenomelia are born at an approximate rate of 1 in 100,000 births. Eight malformation monitoring systems around the world jointly studied the epidemiology of these rare malformations: 102 infants with cyclopia, 96 with sirenomelia, and one with both conditions were identified among nearly 10.1 million births. Maternal age is somewhat increased for cyclopia, indicating the likely inclusion of some chromosomally abnormal infants which were not identified. About half of the infants are stillborn. There is a female excess among infants with cyclopia. Excess twinning occurred for cyclopia and possibly also for sirenomelia. An analysis of associated malformations indicates the similarity between the two conditions, which is in agreement with recent embryological analysis.

Abnormalities, Multiple↗
PubMed1991

Molecular differentiation of two different translocations producing two apparent Ph chromosomes in a patient with CML.

A case of chronic myelogenous leukemia (CML) is described whose leukemic cells appeared to contain two Philadelphia (Ph) chromosomes originating from different translocations involving the two chromosomes 22. The karyotype of the affected cells, established on two different occasions, was: 46,XY,t(9;22)(q34;q11),t(15;22)(p11;q11) with no normal chromosomes 22 and only one 9q+ in each of 115 marrow cells examined. The same findings were present in 50 peripheral blood cells cultured without phytohemagglutinin (PHA) stimulation. When stimulated with PHA, a normal male karyotype was present in the 11 cells examined. There were no additional chromosomal abnormalities and no indication of a blastic crisis after nearly 1 year following the original study. Analysis of the breakpoint cluster region (bcr) on chromosome 22 in the DNA of the affected cells (marrow) revealed evidence for one rearranged chromosome 22 and one normal chromosome 22, indicating that the t(15;22) was not due to the usual Ph translocation seen in CML. The results point to the crucial usefulness of molecular analysis in confirming cytogenetic results related to Ph translocations in CML.

Adult↗
PubMed1991

Parental fertility and infant hypospadias: an international case-control study.

The authors have performed an international case-control study on the significance of exogenous hormones for the origin of hypospadias (Källén et al., 1991 a,b). Using data from this study on 846 infants with isolated hypospadias and equally many controls (next male infant born in the same hospital as the case), variables that might indicate an increased rate of fertility problems in couples who had a boy with hypospadias were studied. Cases had slightly fewer previous pregnancies, there was practically no difference in the rate of previous induced abortions, and no demonstrable difference in menstrual history. Infertility periods of at least 6 months were more likely among cases than controls but the difference did not reach statistical significance in a two-tailed test. There was no demonstrable difference in the time to conceive between cases and controls. The difficulties of directly studying subfertility problems are stressed.

Case-Control Studies↗
PubMed1991

Oral contraceptives in the etiology of isolated hypospadias.

With the objective of identifying whether hypospadias in infants is associated with maternal use of oral contraceptives before pregnancy or in early pregnancy, 846 case-control pairs were collected from eight different malformation monitoring programs around the world and mothers were interviewed using structured questionnaires administered after the birth of the infants. There was no difference in the preconceptional use of oral contraceptives between cases and controls, neither with respect to the number of years of oral contraceptive usage nor the time between stopping oral contraceptives and the present pregnancy. To this material was added data on oral contraceptive usage in early pregnancy from two other sources: an ongoing case-control study in Spain (725 infants with hypospadias) and a population-based study in Sweden (631 infants with hypospadias). There was no statistically significant difference in oral contraceptive exposure in early pregnancy between cases and controls. There is no demonstrable association between oral contraceptive use and infant hypospadias.

Contraceptives, Oral↗
PubMed1991

[Risk for Down syndrome based on maternal ages grouped in intervals of 2 and 5 years in the Mexican population].

Based on the analysis of 515 patients with Down's syndrome, identified in the Mexican program of Registry and Epidemiological Surveillance of External Congenital Malformations, we obtained the risk at birth for this disease, according to the mother's age, grouped in two and five years intervals. The results confirms other studies suggesting that the risk increases after age 30 and particularly 35. For example the incidence in women 21-22 years old is 0.62 per 1000 births and 40.7 in mothers ages 43-44. The data presented can be utilized for genetic counselling in Mexico and we recommend the use of the biannual figures because they are more precise than the usually employed five years intervals results.

Adolescent↗
PubMed1990

Genetic polymorphism of the human sex hormone-binding globulin: evidence of an isoelectric focusing variant with normal androgen-binding affinities.

Human sex hormone-binding globulin (hSHBG) is a plasma glycoprotein composed of two identical subunits. The protein, which has high affinity for testosterone and estradiol has been purified to homogeneity. In this study we have investigated, on neuraminidase-treated serum samples, the presence of genetic variations of hSHBG by polyacrylamide gel isoelectric focusing (IEF). Based on IEF analyses of 110 serum samples from adult Mexican individuals we have identified two distinct IEF-patterns. The most frequent phenotype (95.45%) was characterized by two IEF-bands with pIs of 6.50 and 6.63, respectively. In five serum samples, a different 4-band pattern with pIs of 6.50, 6.63, 6.70 and 6.76 was identified. Family studies showed that this pattern was genetically determined. The frequency of this variant was 4.55%, and the observed phenotypes were consistent with the expression of an autosomal genetic system. The estimated gene frequencies for both alleles were shown to be in genetic equilibrium. Affinity constants, binding kinetics and serum concentrations of hSHBG from individuals having a 4-band pattern were similar to those obtained in individuals with a 2-band pattern, thus suggesting that the mechanism responsible for the generation of polymorphic variants of hSHBG reported herein did not involve the steroid binding site of the molecule. These findings may be of broad interest, as other serum binding proteins express genetic variants, which may permit their further structural and functional subclassification.

Adult↗
PubMed1990

Human lymphocyte proliferation kinetics in Hanks' BSS supplemented with autologous plasma and in synthetic medium.

Human lymphocyte proliferation kinetics was studied in different culture conditions including synthetic medium, Hanks' BSS and Hanks' supplemented with autologous plasma at several culture times. Even though mitotic indices (MI) were low, lymphocytes were able to divide for a few cycles in BSS alone, with a cycling time of around 24 h. Similar cell proliferation patterns with similar MIs, replication indices and cell cycle times of approximately 12 h were obtained with RPMI 1640 and with autologous plasma-supplemented BSS, although lymphocytes exhibited a more uniform MI distribution curve in synthetic medium. The findings mentioned above suggest that Hanks' with autologous plasma may represent a suitable and inexpensive culture condition to avoid undesirable side effects related to synthetic media and heterologous sera, for diagnostics as well as research cytogenetics.

Acetates↗
PubMed1988

Duplication 11q and deletion 5p syndromes due to a reciprocal translocation segregating in four generations.

We report on 2 relatives with duplication 11q and deletion 5p, resulting from an adjacent-1 segregation of a balanced reciprocal translocation 5p15;11q23, segregating in 4 generations of this family. Twelve out of 16 at-risk relatives of inheriting the translocation were shown to be carriers, giving a significant (p less than .05) 3:1 ratio of carriers/noncarriers. The breakpoint on chromosome 11 at q23 is a folate sensitive fragile site into where the proto-oncogene c-ets has been mapped.

Abnormalities, Multiple↗
PubMed1985

Endocrine and biochemical studies in a 46,XY phenotypically male infant with 17-ketosteroid reductase deficiency.

A 46,XY phenotypically male patient with 17-ketosteroid reductase deficiency is described. The patient was a 6-month-old infant who presented with micropenis and bilateral cryptorchidism. Baseline plasma levels of testosterone (T), delta 4-androstenedione (delta 4A), and 5 alpha-dihydrotestosterone (5 alpha-DHT) were within the normal range [patient: 0.17 (T), 0.12 (delta 4A), and 0.032 (5 alpha-DHT) ng/ml; normal infants: 0.03-0.55 (T), 0.14-0.45 (delta 4A), and 0.01-0.23 (5 alpha-DHT) ng/ml]. hCG administration induced a significant rise in plasma delta 4A levels (up to 8.39 ng/ml) and a slight increase in T and 5 alpha-DHT levels. The delta 4A/T ratios before and during the hCG challenge were 0.86 and 55.61, respectively (controls: 0.83 and 0.13). Incubation of genital skin-derived fibroblasts from the patient with either [3H]T or [3H] delta 4A revealed normal formation of delta 4A from T and diminished conversion of delta 4A to T. The development of a male phenotype despite both a testicular and peripheral 17-ketosteroid reductase deficiency is difficult to explain. It is possible that the fetal testes were the source of sufficient amounts of T during the early periods of embryonic life, and that late onset of the enzyme deficiency prevented the development of completely normal male genitalia. The in vitro finding of normal T to delta 4A conversion by the mutant fibroblasts suggests that in this particular tissue 17 beta-reduction and dehydrogenation of androgens are mediated by two isoenzymes with distinct substrate and/or cofactor specificities.

17-Hydroxysteroid Dehydrogenases↗
PubMed1979

Cytogenetic and endocrine studies in a 45,X female subject with spontaneous sexual development.

Cytogenetic and endocrine evaluation of a postpubertal 45,X female subject with Turner's stigmas and spontaneous sexual development was performed. A 45,X chromosomal complement was found in the peripheral blood lymphocytes, bone marrow, and fibroblasts derived from skin and ovaries. Menarche, pubarche, and thelarche occurred at age 12; at age 16 she developed menstrual irregularities, with endometrial bleeding occurring every 60 to 90 days. The ovaries were normal in size, and histologic examination revealed a marked paucity of primordial follicles, increased collagenization, and absence of corpora albicans. Anovulatory cycles with moderately elevated levels of luteinizing hormone (LH) and low follicle-stimulating hormone (FSH) levels were observed. LH-releasing hormone pituitary stimulation induced a normal LH release with a very slight FSH increase. Administration of clomiphene citrate successfully induced a normal-length ovulatory cycle. Similarities in the hormonal situation of this patient and that seen in the Stein-Leventhal syndrome are pointed out.

Adolescent↗
PubMed1979

Gerodermia osteodysplastica hereditaria: report of three affected brothers and literature review.

Gerodermia osteodysplastica hereditaria was diagnosed in three Mexican brothers 6, 7, and 8 years old, respectively, who had the distinct facial appearance with sagging cheeks, premature wrinkling of the skin of face, abdomen, and dorsum of hands and feet; malocclusion, span greater than height; hyperextensibility; winging of the scapulae; stooped posture with kyphoscoliosis; protuberant abdomen; and pes planus. Radiologically they had generalized osteoplorosis, platyspondily due to multiple compression fractures, pseudoepiphyses of second metacarpals, and dislocated hips. Three other families with a total of 14 affected individuals have been reported. Inter- and intrafamilial variability can be recognized, particularly regarding the tendency to fractures, upper:lower segment ratio abnormalities, and results of skin biopsies, which have shown fragmentation of the elastic fibers in some cases (including the present family) and not in others. Although inheritance was considered to be X-linked recessive in the first reported family, an analysis of that pedigree together with those of the other reported families, including the present one, suggests that gerodermia osteodrysplastica is inherited in an autosomal recessive manner.

Abnormalities, Multiple↗
PubMed1979

Frequency of sister chromatid exchanges in severe protein calorie malnutrition.

Nine children with severe protein calorie malnutrition were studied regarding the frequency of sister chromatid exchanges (SCE's) in peripheral blood lymphocytes. The results showed that there was no significant difference between the number of SCE's in the malnourished children as compared to an adequate control group. An interesting finding was that the proportion of 3rd or subsequent division metaphases found in the malnourished children, was higher and significantly different from that seen in the control group.

Adult↗
PubMed1978

Partial trisomies 13 and 22 due to nondisjunction of a maternal reciprocal translocation, t(13;22)(q22;q11).

A family is reported in which the propositus has an extra G-like chromosome with an unusual G-banding pattern. Cytogenetic family studies showed that the mother is a carrier of a balanced reciprocal translocation t(13;22), which does not affect the size and morphology of the chromosomes involved. The propositus has a 47,XY,+der(22),t(13;22)(q22;q11) karyotype and is therefore partially trisomic for the distal third of the long arm of chromosome 13 and for a very small part of chromosome 22. The clinical findings are presented and compared with those of other reported cases of partial trisomies 13 and 22.

Abnormalities, Multiple↗
PubMed1978

45,X/47,XYY mosaicism in a patient with Turner's syndrome.

A patient with classical Turner's syndrome and a 45,X/47,XYY mosaicism is described. Each cell line was present in approximately equal amounts in the peripheral blood lymphocytes, while in fibroblasts derived from skin and both gonads only the 45,X karyotype was present. It is suggested that the latter fact is responsible for the patient not having the mixed gonadal dysgenesis syndrome or tumor formation in both streak gonads.

Adult↗