Search PubMed⌕ Search

Biomedical subjects

M J Martin

Publications and source records attributed to M J Martin.

At least 109 records · Page 6Linked to original sources

Complement activation by human lymphocytes from different lymphoid organs: role of sialic acid and lack of relationship to electrical surface charge.

A study was made of the complement activation (CA) capacity of human lymphocytes from lymphoid organs. Whereas thymocytes did not show complement membrane fluorescence (CMF) following incubation in normal homologous serum (NHS), a mean of 18 and 34%, respectively, of tonsil and spleen cells were positive for antihuman C3 fluorescent serum. Isolated T cells did not show CA capacity, while 62% of a purified tonsil B population possessed this capacity. The CMF was abolished by adding EDTA and when the incubation was performed in C1q and factor-D-depleted serum. Addition of EGTA, supplemented with MgCl2 to NHS failed to abolish the fluorescence, indicating that the alternative pathway was involved in the phenomenon. Removal of sialic acid with neuraminidase increased the percentage of cells showing CMF. Since sialic acid significantly contributes to the extent of net negative surface charge, we have studied whether this parameter influences the CA capacity. Tonsil B cells were separated in fractions with different electrophoretic mobility by preparative cell electrophoresis, and similar percentages of CMF-positive cells were found in all fractions. Therefore, it is likely that the capacity to activate complement is unrelated to the membrane electrical charge.

B-Lymphocytes↗

Serum cholesterol, blood pressure, and mortality: implications from a cohort of 361,662 men.

The risks associated with various levels of serum cholesterol were determined by analysis of 6-year mortality in 361,662 men aged 35-57. Above the 20th percentile for serum cholesterol (greater than 181 mg/dl, greater than 4.68 mmol/l), coronary heart disease (CHD) mortality increased progressively; the relative risk was large (3.8) in the men with cholesterol levels above the 85th percentile (greater than 253 mg/dl, greater than 6.54 mmol/l). When men below the 20th cholesterol percentile were used as the baseline risk group, half of all CHD deaths were associated with raised serum cholesterol concentrations; half of these excess deaths were in men with cholesterol levels above the 85th percentile. For both CHD and total mortality, serum cholesterol was similar to diastolic blood pressure in the shape of the risk curve and in the size of the high-risk group. This new evidence supports the policy of a moderate fat intake for the general population and intensive treatment for those at high risk. There is a striking analogy between serum cholesterol and blood pressure in the epidemiological basis for identifying a large segment of the population (10-15%) for intensive treatment.

Adult↗

Health policy for treating hyperlipidemia: analogy with hypertension and prospects for the next decade.

Over the past 15 years, efforts by the health profession to detect and treat high blood pressure have grown remarkably successful. A similar growth now seems likely for high blood cholesterol. Three factors are responsible: the continuing emergence of scientific evidence corroborating the benefit of lowering high blood cholesterol levels by diet or drugs, the formulation in 1984 of more specific health policy guidelines by the Consensus Development Conference on Lowering Blood Cholesterol and the creation in 1985 of the National Cholesterol Education Program. This program has been designed to enhance preventive activities by the public and by health care professionals. Its success will depend in part on resolving problems with the efficacy and acceptability of life-style and drug interventions for lowering blood cholesterol levels.

Cholesterol↗

Ovarian compensatory hypertrophy following unilateral ovariectomy in the suckled sow.

The effects of unilateral ovariectomy on ovarian compensatory hypertrophy (OCH), endocrine profiles and the pituitary response to gonadotropin releasing hormone (GnRH) were studied in 46 multiparous suckled sows. On d 20 of lactation (d 0 of experiment), sows were subjected to sham ovariectomy (Sham; n = 23) or unilateral ovariectomy (ULO; n = 23). On d 1 (n = 16), 2 (n = 15) or 8 (n = 15) following initial surgery the remaining ovaries in both Sham and ULO sows were removed. Immediately following removal of the remaining ovaries, GnRH (10 micrograms) was administered to each sow. Peripheral blood samples were taken every 10 min for 80 min beginning 20 min prior to GnRH administration. No difference in ovarian weight was observed between ULO and Sham sows until d 8, when ovarian weight was greater (P less than .05) for the remaining ovary from ULO sows (3.96 +/- .21 vs 5.91 +/- .39 g). Ovarian follicular fluid weights from ULO sows were greater (P less than .05) than Sham sows on both d 2 and 8. On d 1, plasma concentrations of follicle stimulating hormone (FSH) were greater (P less than .05) in ULO sows than in Sham sows (2.9 +/- .2 vs 2.1 +/- .1 ng/ml). Plasma FSH concentrations, however, did not differ between Sham and ULO sows on either d 2 or 8. Ovarian venous concentrations of estradiol-17 beta were also greater (P less than .05) in ULO sows compared with Sham sows on d 2 but not d 8.

Animals↗

Race and primary open-angle glaucoma.

A comparison of racial distributions for three groups of patients showed that 115 of 140 patients (81.6%) with open-angle glaucoma, 221 of 392 patients (56.4%) with ocular hypertension, and 1,028 of 2,109 patients (48.7%) in a random sample were black. Average age at diagnosis was significantly (P = .006) higher for whites than for blacks (69.1 years vs 63.7 years). Black patients with primary open-angle glaucoma had a significantly larger mean cup-disk ratio (P less than or equal to .002) and a higher but not significantly higher mean intraocular pressure at the time of diagnosis. Advanced glaucomatous visual field loss was more frequent at the time of diagnosis in blacks (43 of 129 patients or 33.3%) than in whites (five of 27 patients or 18.5%), but this difference was not significant.

Adult↗

Parturition control in sows with a prostaglandin analogue (alfaprostol).

The objective of this study was to determine the dose of alfaprostol (18, 19, 20-trinor-17-cyclohexyl-13, 14 didehydro-PGF(2)alpha-methylester) and the day of administration most effective in inducing sows to farrow during normal working hours (0700 to 1700). One-hundred forty multiparous crossbred sows, taken from a herd whose mean gestation length was 114.3 days, were assigned to one of five treatment groups: 1) control vehicle-propylene glycol, 2) 0.5 mg alfaprostol (AP). 3) 1 mg AP, 4) 2 mg AP and 5) 3 mg AP. Sows received an intramuscular injection of AP between 0800 and 0830 on either day 111, 112 or 113 of gestation. Parameters studied included interval from injection to birth of first pig, farrowing interval, total number of pigs born, number born alive, average birth weight, percent stillborn, interval from weaning to next estrus and number born alive next litter. The mean intervals from injection to the birth of the first pig were 55.2 +/- 7.1; 41.1 +/- 5.1; 29.6 +/- 4.0; 24.3 +/- 1.1; 24.8 +/- 0.9 h for groups 1, 2, 3, 4 and 5, respectively (P<0.05). The percentage of sows that farrowed during normal working hours (23 to 33 h after injection) for groups 1, 2, 3, 4 and 5 were 15, 53, 60, 77 and 70%, respectively. Average birth weights (kg) for treatment groups 1, 2, 3, 4 and 5 were 1.54 +/- 0.05; 1.65 +/- 0.05; 1.59 +/- 0.05; 1.54 +/- 0.05 and 1.42 +/- 0.05, respectively (P<0.05). Mean differences in total number of pigs born and number born alive were also statistically significant (P<0.05) but stillbirth rate was not different (P>0.05) among treatment groups. These results indicate that a single injection of 1, 2 or 3 mg of alfaprostol will successfully induce parturition the following day in a majority of the treated sows.

Journal Article↗

Analysis of the outcome of in vitro fertilization in relation to the timing of human chorionic gonadotropin administration by the duration of estradiol rise in stimulated cycles.

A retrospective analysis was carried out to assess the outcome of ovarian stimulation on in vitro fertilization when human chorionic gonadotropin (hCG) was administered after 5, 6, or 7 days of continuously rising plasma estradiol (E2). There was no significant difference in the number and size of large follicles in each group although the number of small follicles (less than 15 mm in diameter) decreased significantly after 7 days of E2 rise. After hCG injection in the 7-day group, the E2 level fell below the previous day's value in 40% of patients, whereas a similar fall was observed in only 16% of patients in the 5- and 6-day groups. In those cycles where a luteinizing hormone surge occurred, most surges were detected during the seventh day of E2 rise. The pregnancy rate was 31% when hCG was given after 6 days of rising E2, 21% after 5 days, and 14% after 7 days. In patients achieving pregnancy in the 6-day group, 53% of embryos were derived from leading follicles. In the 7-day group, only 15% of embryos associated with pregnancies were derived from leading follicles. These results strongly suggest that in stimulated cycles, hCG should be administered after 6 days of continuously rising E2. It is therefore postulated that 6 days of rising E2 represents a mean optimal period for follicular growth and oocyte maturation in stimulated cycles.

Chorionic Gonadotropin↗

Aspects of multiple embryo transfer.

Three hundred seventy-two patients underwent laparoscopy for in vitro fertilization and embryo transfer. Of these, 156 were treated with clomiphene citrate alone, 203 with clomiphene citrate and hMG, and 13 with hMG alone. Two-hundred seventy-two of these patients underwent embryo transfer, and 55 pregnancies resulted. Of these, 30 were ongoing, 14 biochemical, 6 ectopic, and 5 aborted. Where four embryos were transferred, the pregnancy rate was found to be significantly higher than when a lesser number were transferred. When the embryos transferred were analyzed, however, it was found that fewer than 10% of all transferred embryos implanted and it was largely a function of multiple embryo transfer per patient that led to success. When the type of hyperstimulation was compared, clomiphene citrate cycles were found to be less successful in that they produced fewer oocytes and embryos than did cycles in which hyperstimulation was achieved by supplementary hMG. It is conceded that this is an overall analysis and that individuals, especially those producing twins, had more than one good embryo transferred into a receptive uterus. The data suggest that unsuccessful cycles had somewhat poorer quality embryos, nonreceptive endometria, or a combination of these factors when compared with those of the successful embryo transfer cycles. The only predictive factor as to outcome relates to the multiplicity of embryos transferred. The fact that some IVF cycles produce multiple pregnancies indicates that a predictor of embryo health is urgently required. However, until such a reliable predictor is obtained, multiple embryo transfer remains a major advance in the success of IVF and ET.

Abortion, Spontaneous↗

The luteal phase after hyperstimulation for in vitro fertilization.

Of 500 cycles in which in vitro fertilization (IVF) was undertaken, laparoscopy was performed 372 times, 272 embryo transfers were carried out, and 55 pregnancies resulted, 30 of which resulted in delivery. Of those patients who underwent laparoscopy, 156 received clomiphene citrate alone, 203 clomiphene citrate and hMG, and 13 hMG alone. All patients were found to have a luteal-phase length of 10 days or greater (measured from the time of ovulation). The midluteal urinary total estrogen (UTE) value and pregnanediol excretion (Pd2) far exceeded the levels seen in normal cycles. There were no significant differences between conceptual and nonconceptual cycles and the high levels encountered would be expected after deliberate hyperstimulation. Fifty-five patients (in whom 11 pregnancies resulted) were monitored every other day throughout the luteal phase after embryo transfer. Both conceptual and nonceptual cycles showed a peak in pregnanediol glucuronide level around luteal day 6, which then fell. The level rose again if the corpus luteum was "rescued" by the implanting embryo. While the difference was not statistically significant, the estradiol levels appeared to decrease earlier in the nonconceptual cycles than in the continuing pregnancy cycles. It is important to note that the pattern of steroid production in the follicular phase was similar in both conceptual and nonconceptual cycles. While these data are not conclusive, they suggest that some nonconceptual cycles may have suffered early corpus luteal regression. Whether luteal-phase support is indicated in patients treated with clomiphene or clomiphene/hMG therapy cannot be determined from this study. However, it is thought that a controlled study of luteal-phase support in patients so stimulated is warranted. It appears that patients treated with hMG alone tend to undergo a compressed cycle and should be given luteal-phase support since other studies have reported shortened luteal phases following such hMG therapy.

Chorionic Gonadotropin↗

Local changes in cerebral 2-deoxyglucose uptake during alphaxalone anaesthesia with special reference to the habenulo-interpeduncular system.

The effects of the steroid anaesthetic Althesin (alphaxalone plus alphadolone acetate) on regional cerebral metabolism was studied in female rats. [14C]2-Deoxyglucose (2-DG) uptake was measured in 19 discrete anatomical areas by quantitative autoradiography. Under Althesin anaesthesia metabolic activity, relative to the corpus callosum ( rma ), was significantly (24-46%) increased in the locus coeruleus, medial (but not lateral) habenula (Hb) and interpeduncular nucleus (IPN). The Hb-IPN tract, not discernible in autoradiograms from conscious rats, became readily apparent in films from anaesthetized rats. However, the increased metabolic activity of this pathway was not associated with a significant change in the tissue concentrations of substance P in either the Hb or IPN. In sensorimotor and visual cortex, caudate nucleus, thalamic nuclei and the medial geniculate body rma was significantly (26-38%) depressed. Metabolic activity in the other 8 areas measured was unaffected by Althesin. Destruction of the stria medullaris input to the habenulae prevented the Althesin-induced increase in 2-DG uptake by the MHb and LHb.

Alfaxalone Alfadolone Mixture↗

The MMPI today.

Explore the source record for details and available documents.

Humans↗