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Biomedical subjects

M N Cauchi

Publications and source records attributed to M N Cauchi.

At least 37 records · Page 2Linked to original sources
PubMed1985

Increased frequency of autoantibodies in men with sperm antibodies.

Autoantibodies to thyroid microsomes were more frequent in 102 infertile men with complement-dependent sperm-immobilizing activity (sperm immobilization test [SIT] ) in serum (11.8%) than in a control group of 277 men of comparable ages and semen quality without sperm antibodies (4.3%, P less than 0.05). Frequencies of organ-specific antibodies (antigastric parietal cell, antithyroglobulin, and antithyroid microsome) in 57 men with genital tract obstructions and positive SIT were similar to those for control subjects, and there were no significant differences in the frequencies of non-organ-specific autoantibodies (antinuclear antibody, rheumatoid factor, antimitochondrial, and anti-smooth muscle) in the three groups. Because in men without genital tract obstruction antithyroid microsomal autoantibodies were more common with sperm antibodies than without, the possibility of a genetic factor in the causation of sperm autoimmunity should be considered.

Adult↗
PubMed1985

Changes in lymphocyte status and responsiveness in pregnancy detected by a fluorescent cell probe.

Lymphocyte reactivity assessed by a fluorescent lipophilic probe test of responsiveness to concanavalin A (con A) was shown to differ from normal in early pregnancy. The difference was most marked in multiparas. Abnormal reactivity was detected in the earliest pregnancy examined (5 weeks' gestation) and up to about the 20th week; after 20 weeks, reactivity was normal in all of the multiparas and most of the nulliparas studied. However, in pregnancy induced hypertension (PIH), a disorder of late pregnancy, the same responsiveness as in early pregnancy was found. When unstimulated lymphocytes were examined, abnormal reactivity associated with increased fluorescence was observed in early pregnancy and in PIH, compared with normal late pregnancy, reflecting alteration in lymphocyte membrane phospholipids. It is postulated that pregnancy is associated with sequential change in immunity, disturbance of which may result in immunologically-determined obstetric morbidity.

Adult↗
PubMed1985

The immunoglobulin class of antispermatozoal antibodies in serum.

The aim of this study was to determine the immunoglobulin class of circulating antisperm antibody using a technique called the indirect immunobead test (IBT). In the IBT sperm bound antibodies are detected using polyacrylamide beads coated with rabbit antihuman immunoglobulin classes IgG, IgA, and IgM. Of the 20 infertile men with serum immobilizins, 100% were found to be positive for sperm-bound IgG, 50% positive for IgA, and 0% positive for IgM, using the IBT. Similarly, 20 infertile females with serum immobilizins showed 95% positivity for IgG, 60% for IgA, and 15% for IgM. Thus there was a good correspondence between the presence of serum immobilizins as determined by the sperm immobilization test (SIT) and the IBT. This study provides data that indicates that IgG and IgA are the two major immunoglobulin classes of sperm antibody in male and female immune sera as detected by a simple, sensitive immunological technique, the serum IBT.

Acrylic Resins↗
PubMed1985

The role of fetal adrenal hormones in the switch from fetal to adult globin synthesis in the sheep.

The switch from gamma (fetal) to beta (adult) globin production was studied by the analysis of globin synthesis in chronically cannulated ovine fetuses and newborn lambs. The gamma/alpha globin synthesis ratio decreased from 0.98 +/- 0.11 (S.D.) (n = 4 samples) at 100-120 days of gestation to 0.15 +/- 0.07 (n = 4) in lambs of 150-156 days post-conception, and the beta/alpha synthesis ratio increased from 0.04 +/- 0.06 (n = 4) to 1.13 +/- 0.21 (n = 4) over the same period. In bilaterally adrenalectomized fetuses, which survived in utero until 151-156 days, the gamma/alpha and beta/alpha synthesis ratios were 0.64 +/- 0.14 (n = 3) and 0.25 +/- 0.07 (n = 3) respectively in the 150- to 156-day period. Bilateral adrenalectomy did not affect the time of onset of beta globin synthesis, but significantly decreased the rate. In one bilaterally adrenalectomized fetus the infusion of increasing concentrations of cortisol restored the rate of beta globin synthesis to normal. Treatment of three intact fetuses with 100 micrograms cortisol/h for 3 weeks, from 100 to 121 days, did not affect the timing or rate of switch from gamma to beta globin synthesis. Thus fetal adrenal secretions, probably cortisol, affected the rate of change of gamma to beta globin synthesis but other factors must have been involved in the initiation of the switch.

Adrenal Cortex Hormones↗
PubMed1984

Smoking in pregnancy: relevance of maternal screening tests on fetal outcome.

A number of laboratory parameters were estimated in 54 pregnant women in order to assess whether changes induced by smoking could reflect weight gain in the fetus. There was a significant correlation between maternal weight gain index, oestriol levels, antithrombin III levels and reticulocyte synthesis with infant and placental weight gain. One or more of these tests was found abnormal in 27% of normal pregnant patients, 72% of light smokers, and 89% of heavy smokers. Several other parameters were found to be significantly altered in smoking compared to non-smoking pregnant patients; however, these bore no relationship to infant and placental parameters. These studies indicate that laboratory assessment of a number of maternal parameters could be of some value in determining the likelihood of depressed weight gain by infants of smoking mothers.

Birth Weight↗
PubMed1984

Sperm antibodies, immunoglobulins, and complement in human follicular fluid.

The levels of immunoglobulins (IgG, IgA, IgM), complement (C3, C4, C1EI) and sperm antibodies were determined in plasma and follicular fluid samples from 26 patients undergoing in vitro fertilization (IVF) treatment. The results show that IgG, IgA, C3, C4, and C1EI concentrations in follicular fluid are similar to plasma concentrations (63.1-96.1% of plasma levels). The follicular fluid concentration of IgM was severely reduced, however, being only approximately 10% of plasma concentrations. Sperm antibody titres were compared in three patients using sperm agglutination, immobilization, and immunobead binding. The titres in plasma and follicular fluid were similar, apart from antibodies of IgM class, which were undetectable in follicular fluid.

Antibodies↗
PubMed1984

Detection of antispermatozoal antibodies of IgA class in cervical mucus.

A simple procedure for detection of antisperm antibodies of IgA class in human cervical mucus is described and the results of its application to samples from 102 patients are presented. The results suggest that the IgA immunobead test (IgA-IBT) is a specific and clinically useful test for sperm antibodies. There was a strong correlation between the IgA-IBT and the presence of complement-dependent sperm immobilization in serum (Spearman's, r = 0.92, p less than 0.001). Positive IgA-IBT results occurred only in mucus samples that showed poor penetration by normal sperm. An added advantage of the IgA-IBT is that both the immunoglobulin class and the site of binding to the sperm surface can be determined simultaneously.

Antibodies↗
PubMed1984

Oncofetal antigens in ovarian cyst fluids.

The levels of five oncofetal antigens were measured in ovarian cyst fluids. Significantly raised levels of carcinoembryonic antigen (CEA), human chorionic gonadotropin, beta 2-microglobulin, and alpha-fetoprotein were found in ovarian cyst samples. Human placental lactogen was not detectable in any samples. Mucinous cyst fluids demonstrated higher levels of CEA than serous fluids in both malignant and benign conditions. We could not distinguish between malignant and benign conditions with any of the markers. Except for CEA, there is no difference in values between mucinous and serous cystadenocarcinomas.

Antigens, Neoplasm↗
PubMed1983

Red cell nucleotide levels in patients with thalassaemia, iron deficiency, and renal failure.

Red cell nucleotides, predominantly adenine nucleotides, were measured spectrophotometrically in normal individuals and in patients with iron deficiency, beta thalassaemia and renal failure following dialysis or transplantation. There was a significant correlation between the mean red cell haemoglobin (MCH) or the mean cell volume (MCV) and the nucleotide levels in red cells (P less than 0.001). Patients with beta thalassaemia did not have increased nucleotide levels compared to red cells having the same MCH or MCV. Patients with renal failure had significantly increased levels of nucleotides compared to normal individuals, and this level remained high after renal dialysis but returned to normal following renal transplantation.

Erythrocyte Indices↗
PubMed1983

Prognostic significance of oncofetal antigens in patients with ovarian cancer.

The prognostic significance of elevated oncofetal antigens, namely carcinoembryonic antigen (CEA), alphafetoprotein (AFP), and beta subunit of human chorionic gonadotrophin (beta HCG) were studied in 39 patients with cancer of the ovary. At low cut-off levels, (CEA greater than 2.5 micrograms/l, AFP greater than 5 micrograms/l, and beta HCG greater than 3 IU/l) the median survival was 21 months in patients with one or more positive markers compared to greater than 43 months in patients without markers. At high cut-off points (namely CEA greater than 10 micrograms/l, AFP greater than 10 micrograms/l and beta HCG greater than 10 IU/l), the median survival of patients having one or more positive markers was 10 months compared to greater than 46 months in patients with no markers. Using linear regression and Logrank analysis, the difference between the observed and expected death rate was significant (P less than 0.05 at low cut-off levels, and less than 0.01 at high cut-off levels). These results indicate that patients who have one or more positive oncofetal markers on presentation are likely to have a significantly worse prognosis than patients without markers. Moreover, higher levels of oncofetal markers are associated with correspondingly worse prognosis.

Adolescent↗
PubMed1982

Analysis of rates of globin synthesis in normal human fetuses and neonates and in twins.

The factors responsible for the switch from gamma- to beta-globin synthesis, which occurs in man in the perinatal period, are still unknown. In this study the relationship of fetal maturity (as measured by gestation age and fetal weight) to changing rates of globin synthesis was analyzed. The relationship of rates of erythropoiesis to the switch was also analyzed. Rates of globin chain synthesis were studied in blood from fetuses from 10-41 wk gestation, in neonates up to 6 mo of age, and in a series of twins from 29-40 wk gestation. The beta/gamma-globin synthesis ratio in fetal blood remained relatively constant until 30-34 wk gestation when an increase in beta-globin production was observed. Adult levels of globin synthesis were present in neonates at 6-9 wk after birth. The gamma/alpha-globin synthesis ratio showed a reciprocal change, falling after 30 wk gestation. Globin synthesis ratios in fetuses and neonates from 32-41 wk post-conception showed a significant correlation with age (beta/gamma: p less than 0.001; beta/alpha:p less than 0.001; gamma/alpha: p less than 0.05), and there were significant correlations between the beta/alpha and beta/gamma synthesis ratios and weight (p less than 0.05 for both ratios). Globin synthesis ratios in 12 sets of twins from 29-40 wk gestation were generally within the normal range for gestational age. However, the switch to beta-globin production was more advanced than expected from weight for some of these babies.

Birth Weight↗
PubMed1982

Factors affecting haemoglobin synthesis in the mouse.

The effect of various forms of haematopoietic stress on haemoglobin production was studied in mice. During acute anaemia, recovery from polycythaemia or irradiation, there was an increase in the number of reticulocytes, and this was associated with a marked increase in the total protein synthesis. The specific activity in reticulocytes increased up to 20-fold from the normal. The maximum specific activity usually preceded the maximum peak of reticulocytosis. The proportion of minor haemoglobin increased by up to 30%, and there was a significant correlation between the specific activity in reticulocytes and the proportion of minor haemoglobin synthesized. These results indicate that erythropoietic stress results in the release of a new population of reticulocytes that are very active in protein synthesis as measured by markedly increased specific activity, and that this coincides with an increase in the proportion of minor haemoglobin produced.

Anemia↗
PubMed1982

Quantitative aspects of red cell size variation during pregnancy.

Red cell volume distribution curves may be readily obtained using electronic cell counters, and the proportion of cells that deviate from the normal population may be determined. In this study, we report the results of red cell volume distribution analyses in pregnant and non-pregnant females. The relationship between red cell volume distribution and other red cell indices is also studied. Statistical analysis showed good correlation between various Channelyzer parameters and red cell indices including Hb, RCC, MCV, MCH, and MCHC. A significant proportion of pregnant patients showed abnormal red cell volume distribution curves particularly in the latter half of pregnancy. During the latter half of pregnancy there was an increased proportion of microcytic cells in 8% of patients and evidence for macrocytosis was found in 67% of patients. In general there was good correlation between stages of gestation and Channelyzer parameters associated with macrocytosis. It is suggested that analysis of red cell size, which may be simply performed with minimal quantities of blood and inconvenience using the Channelyzer, could give insight into those conditions associated with variation in red cell size including iron deficiency and folate deficiency in pregnancy and it is conceivable that repeated estimations of these parameters could obviate the need for blanket administration of haematinics to the pregnant patient.

Adult↗