PubMed Health⌕ Search

Biomedical subjects

Y C Smart

Publications and source records attributed to Y C Smart.

47 records · Page 3Linked to original sources
PubMed1984

Observations on rat collagenase-separated islets and long-term composite islet allografts.

Collagenase digest preparations of isolated rat islets and long-surviving allogeneic rat islets implanted beneath the kidney capsule of a composite kidney and islet allograft have been studied immunocytochemically and by electron microscopy. The four main endocrine cell types were identified in the collagenase preparations with minimal evidence of cell damage. In contrast, there were only granulated B cells in the composite grafts and amongst the granules of these cells there was pleomorphism. The granule appearances may support previous suggestions that paracrine control of insulin secretion is lacking in these composite grafts.

Animals↗
PubMed1983

Effects of age, gender, and cigarette smoking on human immunoregulatory T-cell subsets: establishment of normal ranges and comparison with patients with colorectal cancer and multiple sclerosis.

Normal ranges for peripheral circulating mature functional T cells (OKT3+), T helper-inducer cells (OKT4+), and T cytotoxic-suppressor cells (OKT8+) were determined in 161 normal male and female volunteers. Children between 5 and 15 years of age showed higher circulating OKT3+ cell numbers than adults, and in male children the circulating OKT4+ cell number was also higher. In adults, females demonstrated higher circulating OKT4+ cell numbers than males, and smokers demonstrated higher circulating numbers of both OKT3+ and OKT4+ cells than nonsmokers. There was a significant interaction between gender and smoking, with female smokers exhibiting the highest circulating OKT3+ cell numbers. Two groups of patients entering longitudinal T-cell subset monitoring studies were compared to their appropriate normal control groups. It was found that 48% of patients with colorectal cancer were T-cell (OKT3+) lymphopenic at presentation, and that 62% had a low OKT4/OKT8 ratio. Colorectal surgery tended to correct this T-cell lymphopenia. However, only transient rises in low OKT4/OKT8 ratios were observed after surgery. Of 11 patients with multiple sclerosis in a trial of transfer factor therapy, 7 were found to have high OKT4/OKT8 ratios prior to treatment; these ratios have persisted to date during treatment.

Adolescent↗
PubMed1982

Early pregnancy factor as a monitor for fertilization in women wearing intrauterine devices.

Measurement of early pregnancy factor (EPF) by the rosette inhibition test was performed on serum samples from 14 women using intrauterine devices (IUDs). Serial blood samples taken during the luteal phase of 23 cycles demonstrated in six of the cycles a transient appearance of EPF during the 6- to 8-day period following ovulation. In contrast, no EPF activity was found in sera obtained from women in whom fertilization was prevented, either by sexual abstinence or tubal ligation. These observations support the postulate that the IUD functions by the prevention of implantation of the fertilized ovum, rather than by preventing fertilization.

Adult↗
PubMed1982

Validation of the rosette inhibition test for the detection of early pregnancy in women.

The authors validated use of the rosette inhibition test for the detection of early pregnancy factor (EPF) in human pregnancy, first by optimizing conditions for the assay, using known pregnant and nonpregnant sera, and second, by examining the performance of this assay in three clinical situations: a "blind" study involving coded first-trimester sera showed 80% correlation with pregnancy status; serial assay of EPF activity in sera collected from normal women attempting to conceive, correlated with human chorionic gonadotropin beta-subunit (beta-hCG) levels and pregnancy status; a longitudinal study of serial serum samples through two normal pregnancies showing the continued presence of EPF until the early third trimester in each case. It was concluded that with the rosette inhibition assay, consistent demonstration of a pregnancy-associated substance (EPF) could be obtained.

Chaperonin 10↗
PubMed1982

Fertilization and early pregnancy loss in healthy women attempting conception.

The rosette inhibition test was used to monitor the activity of an early pregnancy factor (EPF) in sera collected from 18 healthy women who were attempting to conceive. Serial blood samples collected during the luteal phase of 21 menstrual cycles demonstrated the appearance of EPF in 14 of the cycles, of which six showed only transient EPF activity over a 5-10 day period following ovulation. These results indicate a 67% rate of fertilization and a 36% rate of early conceptus losses.

Abortion, Spontaneous↗
PubMed1981

Detection of an immunosuppressive factor in human preimplantation embryo cultures.

Within 48 hours of fertilization of human preovulatory oocytes in vitro, an immunosuppressive factor was detected in the culture medium by a rosette inhibition test. Cultures in which fertilization of the oocyte was unsuccessful were indistinguishable from control medium. Release of an early pregnancy factor from the preimplantation embryo could be of clinical significance to the establishment of pregnancy after embryo transfer.

Chaperonin 10↗
PubMed1981

Early pregnancy factor: its role in mammalian reproduction--research review.

An immunosuppressive early pregnancy factor associated with mammalian reproduction is currently attracting considerable interest. Research into its detection, site of production, distribution, immunosuppressive property, characterization, and application is in progress in a number of laboratories. This review aims to crystallize the current research findings and to identify significant areas for further investigation and application.

Animal Husbandry↗
PubMedDate not supplied

Comparative study of two immunocytochemical techniques in the electron microscopical detection of alpha-1-antitrypsin in routinely processed liver biopsies.

Two indirect immunocytochemical techniques using different markers, namely peroxidase and gold, were applied to ultrathin sections of liver biopsies to detect alpha-1-antitrypsin. The blocks used were taken from the routine electron microscopy files and had been processed optimally for maximum ultrastructural preservation. The immunogold technique provided the best method for localizing alpha-1-antitrypsin and was associated with ultrastructural preservation equivalent to that seen in routinely processed liver biopsies. The procedure may be a useful adjunct to understanding the pathogenesis of alpha-1-antitrypsin deficiency and in recognizing further variants of this disorder.

Biopsy↗