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Biomedical subjects

A G Hunter

Publications and source records attributed to A G Hunter.

At least 109 records · Page 6Linked to original sources
PubMed1985

Chondrodysplasia punctata in an infant with duplication 16p due to a 7;16 translocation.

This paper describes a newborn with a number of clinical manifestations compatible with duplication 16p due to a 46, XY, -7, +der (7), t(7;16) (p22;p13) pat karyotype. In addition, the baby had chondrodysplasia punctata, whose distribution of lesions did not match any of the well-documented forms of these disorders. The baby also had microcornea and lacked a gallbladder, two features, in addition to chondrodysplasia punctata, that have not previously been noted in cases of duplication 16p.

Chondrodysplasia Punctata↗
PubMed1985

A study of institutionalized mentally retarded patients in Manitoba: over-representation by Canadian Indian children.

During analysis of data on 406 severely and profoundly mentally retarded children and their families in Manitoba a marked excess of Canadian Indian children was observed. There was no evidence to suggest that the over-representation by native children was due to an increased propensity of Indian families to institutionalize their children nor were these patients more profoundly retarded or more physically handicapped than the non-Indian children studied. Further analysis showed that Indian children were primarily over-represented in the groups with acquired retardation, autosomal recessive genetic disorders, idiopathic retardation with seizures and idiopathic retardation with malformations or dysmorphic signs. Review of other demographic findings indicated that other factors potentially predisposing to retardation, including low socioeconomic status, illegitimacy, high birth order, poor maternal reproductive history and increased consanguinity, were more common in the histories of native children. Severe and profound mental retardation has been said to occur equally in all strata of society. This evidently was not so in this Canadian population and the Indian child may be at special risk. Health care workers should be aware of possible predisposing factors for retardation in this group if reduction of the incidence of this major problem is to be achieved.

Adolescent↗
PubMed1985

The characteristic physiognomy and tissue specific karyotype distribution in the Pallister-Killian syndrome.

We report a child with clinical features remarkably similar to those of our patient reported as tetrasomy 21 in 1982. Improved banding in this, and the previous case, together with gene dosage studies, and subsequent reports in the literature lead us to conclude that these patients are in fact tetrasomic for 12p. The clinical features of these children are most distinctive and the importance of their recognition lies in the fact that the abnormal cell line is virtually confined to fibroblast studies.

Chromosome Aberrations↗
PubMed1985

Detection at amniocentesis of a maternally inherited X;Y translocation.

G banded chromosomal analysis of cells from a routine amniocentesis revealed a Y to X translocation in the fetus. The same unbalanced translocation was found in the mother who was disproportionately short. H-Y antigen titers in the mother were intermediate and steroid sulfatase activity was in the normal female range. At birth the baby exhibited few dysmorphic features but appeared to have short limbs.

Adult↗
PubMed1985

In vitro maturation of bovine cumulus enclosed primary oocytes and their subsequent in vitro fertilization and cleavage.

Cumulus enclosed primary oocytes from 2 to 4-mm bovine follicles were matured in vitro in Minimum Essential Medium containing follicle-stimulating hormone (0, .1, 1, 10, 50, or 100 micrograms/ml) or human chorionic gonadotropin (0, .1, 1, or 10 IU/ml) for 48 h at 37 degrees C under paraffin oil. Cumulus mass expansion comparable to that seen in vivo occurred in 18% of the control oocytes, 39% of those cultured in human chorionic gonadotropin, and 56% of those cultured in follicle-stimulating hormone. The optimum follicle-stimulating hormone concentration for cumulus expansion was 1 microgram/ml, and this was then used to mature oocytes individually or in groups of 5 for in vitro fertilization. Ejaculated bovine semen, extended 1:10 with yolk-TES-Tris extender and stored 24 to 48 h at 4 degrees C, was warmed, washed once with Minimum Essential Medium, and 500,000 motile sperm/ml were used to inseminate the matured oocyte-cumulus cell complexes. Criteria for fertilization was cleavage to the two-cell stage 48 h after insemination. Oocytes, inseminated individually, cleaved with a frequency of 5%, whereas 15% of those inseminated in groups of 5 cleaved, perhaps as the result of cumulus factors enhancing capacitation. The cleavage rate for the parthenogenetic control with killed spermatozoa was 0%. Therefore, primary oocytes matured in vitro to secondary oocytes were successfully fertilized in vitro and cleaved to at least the two-cell stage in the Minimum Essential Medium. Individual differences between bulls in ability to fertilize in vitro were noted.

Animals↗
PubMed1985

Immunosuppressive activity of bovine seminal plasma on bovine lymphocytes in vitro.

Pooled seminal plasma obtained from six bulls was tested for its immunosuppressive activities in vitro on blastogenesis of bovine lymphocytes. Lymphocyte stimulation assay and mixed lymphocyte reaction were used as test procedures. Concanavalin A and phytohemagglutinin were utilized in the lymphocyte stimulation assays as nonspecific stimuli. Tritiated thymidine uptake by the lymphocytes was measured after incubation for 5 d with seminal plasma. Undiluted seminal plasma was cytotoxic to lymphocytes up to and at 1/100 dilution but not at 1/400. Undiluted seminal plasma was immunosuppressive at a 1/400 dilution. Lyophilization of seminal plasma without prior dialysis resulted in loss of immunosuppressive activity. After dialysis and lyophilization, the reconstituted seminal plasma suppressed thymidine uptake by Concanavalin A and phytohemagglutinin-stimulated bovine lymphocytes while being noncytotoxic. This paper documents that bovine seminal plasma is immunosuppressive and also cytotoxic to the bovine cells that generate an immune response.

Animals↗
PubMed1985

Identification of an immunosuppressive protein in bovine seminal plasma with activity against bovine lymphocytes.

Seminal plasma was determined to have immunosuppressive activities in vitro on Concanavalin A-induced blastogenesis of bovine lymphocytes. This immunosuppressive activity was isolated and characterized using a pool of seminal plasma from five bulls. The immunosuppressive activity was associated with seminal plasma proteins of less than 50,000 daltons and also with those of approximately 150,000 daltons. The 150,000-dalton proteins were precipitable at 33% saturation with ammonium sulfate and with an antibody to a Sephadex G-200 chromatographic fraction of seminal plasma. The immunosuppressive activity of the less than 50,000 dalton proteins was lost upon chromatography on Sephadex G-25. This suggests that interaction of several components of low molecular weight might be necessary for this inhibitory activity to be expressed.

Animals↗
PubMed1985

Immunosuppressive activity of bovine follicular fluid on bovine T lymphocytes in vitro.

Follicular fluid from bovine follicles at various stages of the estrous cycle and cysts were tested in vitro for immunosuppressive activity. Mitogen-stimulated lymphocyte assays and the mixed lymphocyte reaction were used as test procedures and thymidine uptake was monitored. Follicular fluid and cyst fluid inhibited the deoxyribonucleic acid synthesis response of bovine lymphocytes to mitogenic and antigenic stimulation. The nature of the suppression varied with the mitogen or antigen assay used, with the estrual stage, with size of follicle within the diestrual stage, and with the type of ovarian cyst. Blood sera from estrual or diestrual cows were not immunosuppressive. Heating (56 degrees C for 30 min) follicular fluid from normal follicles and cysts destroyed most of its suppressive activity toward Concanavalin A-stimulated lymphocytes but did not suppress that in luteal cyst fluid. The suppressive activity in follicular fluid toward phytohemagglutinin-stimulated lymphocytes was more stable to heat than that against Concanavalin A-stimulated lymphocytes. Because the immunosuppressive activity in follicular fluid was heat labile, estrogen, progesterone, and other steroids were not the active suppressive molecules. Proposed roles for these immunosuppressive substances are hypothesized in preventing autoantibody formation to the zona pellucida and in the inflammatory reaction leading to ovulation.

Animals↗
PubMed1985

Effect of estrual stage on complement activity in bovine follicular fluid.

Ovaries were excised from 112 cows during specific stages of the estrous cycle and from cows with follicular cysts. Follicular fluid was collected from the largest follicle at estrus (d 1), metestrus (d 2 to 4), early diestrus (d 5 to 8), mid diestrus (d 9 to 14), late diestrus (d 15 to 18), proestrus (d 19 to 21), and from follicular cysts. Complement was measured with a standard hemolytic assay. Complement in follicular fluid varied with stage of cycle and was two to five times higher at estrus than at diestrus. Complement in follicular fluid was 5 to 22-fold higher than in blood serum. Blood complement was not influenced by stage of cycle. Cystic follicular fluid had complement amounts similar to that of metestrus follicles. The relationships of complement to ovulation, sperm maturation, fertilization, and sperm removal from the tract are discussed.

Animals↗
PubMed1985

Association of asthenozoospermia with a deficiency of a seminal glycoprotein.

Two major glycoprotein bands (Rf 0.67 and 0.49) were detected with polyacrylamide disc gel electrophoresis in normal human semen, spermatocele fluid and prostatovesicular fluid. The most rapidly migrating band (Rf 0.67) was either present in only trace amounts or absent in asthenozoospermic semen. The protein moiety of this glycoprotein was present in normal and asthenozoospermic semen, but it was not glycosylated in asthenozoospermic semen. It is suggested that there is a relationship between this glycoprotein and the acquisition of sperm motility.

Electrophoresis, Polyacrylamide Gel↗
PubMed1984

Neural tube defects in Eastern Ontario and Western Quebec: demography and family data.

This paper reports the results of a study of families in the Eastern Ontario/Western Quebec region who had a child born with a neural tube defect during the years 1969-1981. As in several other geographic areas, the prevalence of neural tube defects at birth has fallen from previous levels. However, there was no evidence of further decline during the period of study. Socioeconomic and ethnic influences were noted, but there was no evidence of seasonal variation or any correlation with maternal age or parity. There was support for a causative role of maternal fever in some cases. The rates of miscarriage varied between pregnancies before and those after the proband, and there was an excess of males born prior to the proband. Family studies showed a 2.4% risk for sibs born after the proband and an excess of affected relatives on the maternal side. Knowledge of rates of occurrence in relatives is useful for counseling and the interpretation of the results of alpha-fetoprotein screening.

Abortion, Spontaneous↗
PubMed1984

Ovine internal parasitism in the Yemen Arab Republic.

Internal parasitism was studied in five flocks in different regions of the Yemen Arab Republic. Ewes and lambs were faeces sampled from the spring of 1977 to the spring of 1978 and helminth-free tracer lambs were subsequently run with three of the flocks from October 1978 to November 1979. The findings indicated that ovine helminthiasis and fascioliasis may be of importance with the following regional variations: Haemonchosis all the year round in the Tihammah coastal plain. Haemonchosis and trichostrongylosis in the periparturient period in the Southern Uplands and Western Foothills. Fascioliasis and nematodiriasis in the Inter-Montane Plains of the Highlands. Possible control regimes are suggested for further investigation.

Animals↗
PubMed1984

Antigens in bovine estrual and cystic follicles.

The antigenic spectra of estrual or cystic follicular fluid (FF) consisted of 11 blood serum antigens while that of estrual or cystic ovary consisted of 9 identical antigens of which 2 were ovarian specific. The two ovarian-specific antigens were detected with antisera to estrual or cystic ovary but not with antisera to nonestrual ovaries. They were in higher concentration in estrual ovary than cystic ovary, were localized in bovine oocyte zona pellucida by immunofluorescence and light scattering, and cross-reacted with prostate tissue. Cystic FF contained a higher concentration (P less than 0.05) of IgG than at any stage of the cycle except estrus, and a lower concentration (P less than 0.05) of estradiol-17 beta than at estrus. It was hypothesized that increased levels of estradiol during estrus alter the permeability of the follicle wall unmasking a zona pellucida antigen in the preovulatory follicle. The appearance of this previously unexposed antigen at estrus could lead to an inflammatory-like response triggering ovulation.

Animals↗
PubMed1984

Corneal pathology and aniridia associated with partial trisomy 2q, due to a maternal (2;6) translocation.

A newborn with partial trisomy 2q, due to a maternal (2;6) translocation is presented. The baby had microcephaly, a prominent forehead, hypertelorism, a broad nose with a flat nasal bridge, a long philtrum, micrognathia, and low set ears which are common to cases with partial 2q trisomy. Additional findings of aniridia and marked corneal pathology are reported.

Chromosomes, Human, 1-3↗
PubMed1983

The genetics of congenital malformations.

In this paper I have attempted to review briefly both how and why visible chromosome and invisible gene abnormalities may cause congenital malformations and syndromes. The causes may represent nonspecific disturbances in the timing of embryologic events or specific effects on a particular tissue, organ, or cell type. Several different biochemical pathways or structural proteins may impinge upon a single or several embryological events; several genes may be involved in a single pathway, and different changes may affect a single gene. The end result of many of these different processes may well be a similar morphological manifestation. An appreciation and understanding of the potential diversity of genetic causes for a malformation, and the wide variation in the phenotypic expression of malformations or syndromes that is typically seen, is essential if one is to provide adequate medical management to patients and their families. The rapid advances being seen today in the fields of genetics and embryology hold great potential for a true understanding of the developmental biology of, and the ultimate prevention of, congenital malformations.

Chromosome Aberrations↗