Carotid Anatomy Does Not Predict the Risk of New Ischaemic Brain Lesions on Diffusion-Weighted Imaging after Carotid Artery Stenting in the ICSS-MRI Substudy.

INTRODUCTION: The International Carotid Stenting Study (ICSS, ISRCTN25337470) randomized patients with recently symptomatic carotid artery stenosis > 50% to carotid artery stenting (CAS) or endarterectomy. CAS increased the risk of new brain lesions visible on diffusion-weighted magnetic resonance imaging (DWI-MRI) more than endarterectomy in the ICSS-MRI Substudy. The predictors of new post-stenting DWI lesions were assessed in these patients. METHODS: ICSS-MRI Substudy patients allocated to CAS were studied. Baseline or pre-stenting catheter angiograms were rated to determine carotid anatomy. Baseline patient demographics and the influence of plaque length, plaque morphology, internal carotid angulation, and external or common carotid atheroma were examined in negative binomial regression models. RESULTS: A total of 115 patients (70% male, average age 70.4) were included; 50.4% had at least one new DWI-MRI-positive lesion following CAS. Independent risk factors increasing the number of new lesions were a left-sided stenosis (incidence risk ratio [IRR] 1.59, 95% CI 1.04-2.44, p = .03), age (IRR 2.10 per 10-year increase in age, 95% CI 1.61-2.74, p < .01), male sex (IRR 2.83, 95% CI 1.72-4.67, p < .01), hypertension (IRR 2.04, 95% CI 1.25-3.33, p < .01) and absence of cardiac failure (IRR 6.58, 95% CI 1.23-35.07, p = .03). None of the carotid anatomical features significantly influenced the number of post-procedure lesions. CONCLUSION: Carotid anatomy seen on pre-stenting catheter angiography did not predict of the number of ischaemic brain lesions following CAS.

Beef production options and requirements for fossil fuel.

A large percentage of the feed resources used in beef production cannot be used by man or most other animals. These noncompetitive feeds could be used in different ways to increase beef production, but fossil fuel consumption by the beef industry would not be greatly reduced.

Qualitative difference in follicle-stimulating hormone activity in the pituitaries of young women compared to that of men and elderly women.

The possible existence of qualitative differences between FSH in pituitaries from men and women of different ages was investigated with the use of an in vitro bioassay, an in vitro bioassay, and a RIA. Aqueous extracts were made from pituitaries obtained at autopsy and frozen until extracted. The FSH activities per pituitary and the ratios of FSH activities as obtained with the three assay methods were similar for young and elderly men. The ratios of in vivo biological to in vitro biological FSH activities were similar for men and postmenopausal women and significantly higher than the corresponding ratio for FSH from young women. With the in vivo bioassay the activity in the extracts of pituitaries from men and young women were similar, whereas extracts from postmenopausal women had significantly higher activity. With the in vitro bioassay the extracts from young women and elderly women had a similar content of FSH activity, whereas the FSH level in the extracts of male pituitaries was significantly lower. The results of the RIA correlated well with those of the in vitro bioassay. In conclusion, the results show that FSH in pituitaries from young women has a biological activity that is qualitatively different from FSH of men and elderly women. The relatively low in vivo biological activity of FSH from young women compared to FSH from men and elderly women was most likely due to a more rapid clearance of the hormone from the circulation of the test animal.

Absence of hCG-like activity in the blood of women fitted with intra-uterine contraceptive devices.

Blood was obtained at various stages of the menstrual cycle from 201 women fitted with intra-uterine contraceptive devices (IUDs), and plasma levels of hCG were determined by radioimmunoassay. Urine samples were obtained from 117 of these women and tested, before and after sephadex gel filtration, in a haemagglutination inhibition test for pregnancy (Pregnosticon). Plasma hCG was undetectable (less than 25 MLU/ml) in all but one of the 201 women and, in this instance, the hCG-assay appeared to be measuring a midcycle peak of LH, as evidenced by high plasma FSH levels. All unextracted urines gave negative results in the Pregnosticon test but, after extraction, 18 of the 117 urines gave positive reactions, most of these being from women at midcycle or in the luteal phase. We conclude that the IUD does not permit the development of the embryo to a point where it is capable of secreting measurable amounts of hCG. Recent claims to the contrary are probably due to cross-reaction of LH or non-specific interference in the assays used for measuring hCG.

Relationship of the sex of the foetus to the amount of human chorionic gonadotrophin in placentae; single and dizygotic twin placentae compared.

Human chorionic gonadotrophin (HCG) was assayed by biological and radioimmunological methods in placentae from 16 women with a normal twin pregnancy. When the concentration and total amount of HCG in placentae was related to the sex of the twin foetus, no significant difference between 'male' and 'female' placentae was found. This is contrary to findings that there is a significant (P less than 0-005) difference in the concentration of HCG per g and per placenta of singletons at term. A comparison between the grouped geometric mean data from bioassays shows that the amount of HCG per g and per placenta falls between the geometric mean values for 'male' and 'female' singleton placentae.

Accuracy of a calculating system in transcribing output from a reaction rate analyser.

A system for the mechanized calculation and transcription of output from a reaction rate analyser has been evaluated in the performance of 8 enzyme assays, many of which show anomalous kinetic behaviour with regard to "lag" or "accelerated" phases or "blank" reactions. For all of these enzymes, a cycle of three consecutive 18-second readings per assay proved optimal, the result being based upon the final output value unless this showed marked discrepancy with the second value, in which circumstances it is helpful to refer to a strip chart recording of the progress curve. Excellent agreement was obtained with manually-derived results and the system functioned without downtime for more than one year. Marked descrepancies between manual and mechanised results were invariably traced to technician error.

Subchronic effects of gum arabic (Acacia) in the rat.

Young Wistar rats were fed gum arabic (GA) at dietary concentrations of 0% (two control groups), 1, 2, 4, 8 and 20% for 13 weeks. The criteria studied were body weights, food and water consumption, urinalysis, liver and kidney weights, clinical chemistry, haematology, and histology. No untoward effects were observed at dose levels below those which caused dietary imbalance. At the top dose, female rats showed a small reduction in kidney weight, caecal enlargement, and changes in serum urea and total CO2. Male rats showed no differences from the control groups at dietary concentrations up to approx. 8%, but food and water consumption, body weight, liver and kidney weights all decreased significantly and caecal enlargement was evident at the top dose tested. There were no histological changes and no significant changes in haematological parameters in male or female rats at the top dose tested. The no-untoward effect concentrations were 8.6% (5.2 g/kg/day) and 18.1% (13.8 g/kg/day) for male and female rats respectively.

Evaluation of the sub-human primate tube test for pregnancy in primates.

A haemagglutination inhibition test, developed specifically for primates, diagnoses early pregnancy in the chimpanzee, gorilla, orang-utan and baboon. The test was sensitive and reacted positively when the concentration of gonadotrophin in urine was equivalent to 0.03 i.u. human chorionic gonadotrophin per ml. This degree of sensitivity and the certitude that it cross-reacts with primate luteinizing hormone probably accounts for most of the false positive results.

Chromatographic studies on a chorionic gonadotropic activity in the placenta of the rat, mouse and hamster.

Acetone-ether extracts of rat, mouse and hamster placentae were fractionated by molecular sieve chromatography on Sephadex G-200. The fractions were tested for immunoreactivity in human chorionic gonadotropin (hCG), hCG-beta-subunit and alpha-subunit radio-immunoassay systems. The elution profiles were compared with those of similar chromatographic studies of a human placental extract and of purified preparations of hCG and its subunits. The results indicate that rodent placentae have a chorionic gonadotropin and that this hormone in the rat, mouse and hamster is structurally similar to hCG with its alpha- and beta-subunits. Extracts of rat and hamster placentae had a gonadotropic activity similar in concentration to that found in normal human placentae at term. Until now, it has been difficult to find an animal model for studying how the production of chorionic gonadotropin is regulated. Our results suggest that rodents may be suitable for such an investigation.

Prediction of ovulation using a dipstick sensitive to urinary luteinising hormone.

Accurate prediction of ovulation is essential for patients receiving donor insemination (AID). In 9 patients, detection of the urinary luteinising hormone (LH) surge by monoclonal antibody immunospecific dipstick tests (Ovustick) for both home and laboratory use was assessed with simultaneous quantitative estimations of plasma and urinary LH. In all patients the Ovustick accurately detected within 24 hours the beginning of the plasma LH surge. This test may prove to be a useful method for ovulation prediction but further evaluation is required.

An appraisal of the mouse uterine weight assay for the bioassay of chorionic gonadotrophin in the macaque term placenta.

The results obtained in this investigation have shown that the increase in uterine weight of 21-day-old mice, injected with monkey CG, was affected significantly by the number of injections made, the interval between injections and the time of autopsy after the first injection. Failure to take account of these factors may explain why some investigators, using the increase in mouse uterine weight as the index of response, do not find CG in macaque placentae after the 10th week of pregnancy. The present investigation confirmed that extracts of term placentae from rhesus and stump-tailed monkeys contained measurable amounts of CG whose biological activity could be neutralized by an anti-hCG serum.

Chorionic gonadotropin in the placenta of a chimpanzee (Pan troglodytes).

Chorionic gonadotrophin (CG) concentration in the 'near term' chimpanzee placenta was similar to that of human term placentae and significantly (p smaller than 0.05) higher than that found in term placentae of marmosets and rhesus monekys. A significant linear relationship, correlation coefficient r equals +0.999, was found between log mean placental weight and log mean CG concentration in placentae from marmosets, rhesus monekys and the chimpanzee.