Detection of dimeric inhibin throughout the human menstrual cycle by two-site enzyme immunoassay

OBJECTIVE We have developed and validated a two-site immunoassay for the measurement of dimeric inhibin in plasma and subsequently measured dimeric inhibin levels in plasma through the normal female menstrual cycle. DESIGN Recombinant inhibin added to plasma samples was quantitatively recovered in both follicular and luteal phase, and serial dilutions of samples were tested for parallelism to similar dilutions of recombinant 32kDa inhibin. Daily samples were assayed from four women through a menstrual cycle. PATIENTS (a) Four groups of six women who (i) were in the follicular phase of a normal menstrual cycle, (ii) were in the luteal phase of a normal menstrual cycle, (iii) were post-menopausal and (iV) who had received hMG to induce superovulation. (b) Four healthy female volunteers aged 25–33. RESULTS Post-menopausal women had less than 2ng/l of inhibin whereas six women treated with hMG had dimeric inhibin concentrations up to 1125ng/l. During the early follicular phase, at the time of onset of menstruation, extremely low levels of dimeric inhibin were found (3-4ng/l (CI 2.2-5.0)) while in the late follicular phase, there was a marked increase in dimeric inhibin concentration. The concentration of dimeric inhibin was maximal (65.6 ng/l (CI 53.1-81,1)) in the mid-luteal phase. The overall pattern of dimeric inhibin concentration during the menstrual cycle was similar to that observed with previous inhibin assays although the magnitude of change was considerably greater. CONCLUSION The human ovary, In particular the corpus luteum, secretes significant amounts of dimeric and therefore biologically active inhibin.     

Effect of immunoneutralization of LH releasing hormone on LH, FSH and ovarian steroid secretion in the preovulatory phase of the oestrous cycle in the ewe

Immunoneutralization of LH releasing hormone (LHRH) by the i.v. administration of LHRH antiserum in the preovulatory period in the ewe resulted in a prompt abolition of the pulsatile secretion of LH without alteration of basal plasma levels of LH. This resulted in an immediate cessation of the pulsatile secretion of ovarian oestradiol, with no change in the secretion rate of androstenedione or plasma levels of FSH. The ovarian secretion rate of testosterone increased significantly. Twenty to 22h after the injection of LHRH antiserum, pulsatile secretion of LH and ovarian oestradiol and androgen secretion remained suppressed while plasma levels of FSH had increased significantly. The bolus injection of ovine LH (10 micrograms, i.v.) at this time caused a significant increase in oestradiol, androstenedione and testosterone, these responses being inversely related to the titre of LHRH antiserum in the plasma at this time. These results show that (1) the secretion of oestradiol from the preovulatory sheep follicle is entirely dependent on the pulsatile secretion of LH and (2) since the secretion of ovarian androgens was not inhibited, LH may exert a short-term control over the aromatase enzyme system controlling the conversion of androgen to oestrogen in the granulosa cell of the preovulatory sheep follicle.     

Complete heart block during cardiac catheterization in a normal individual

A 44-year-old white male who developed third-degree heart block during cardiac catheterization is presented. Right heart catheterization precipitated bifascicular block, right bundle branch block with left posterior hemiblock, and resulted in third-degree heart block during the left heart procedure. It is recommended that multiple electrocardiographic lead monitoring be considered during cardiac catheterization in order to recognize more easily high-risk conduction disturbances, ie a bifascicular block pattern with frontal plane axis shifts.     

Percutaneous gastrostomy in patients with a ventriculoperitoneal shunt: case series and review

BACKGROUND: There are few data on the safety of PEG in patients with a ventriculoperitoneal shunt. METHODS: Medical records for patients seen in 3 tertiary care, university-affiliated hospitals between January 1, 1991, and January 1, 1999, were reviewed. OBSERVATIONS: Six patients underwent PEG after ventriculoperitoneal shunt placement during the study period. There was no immediate complication. One patient died of pneumonia 2 months after PEG insertion. There was no instance of shunt malfunction, intra-abdominal complication, or wound infection in the study group. There was no long-term complication, with either the ventriculoperitoneal shunt or the PEG. CONCLUSIONS: Although the number of cases was small, PEG placement with prophylactic administration of antibiotics appears to be safe in patients with a pre-existing ventriculoperitoneal shunt.     

Pseudoaneurysm of the Left Ventricle

Abstract: A case study is reported of a patient with rheumatoid arthritis who developed a pseudoaneurysm of the left ventricle after inferior myocardial infarction. The clinical diagnosis was confirmed by radionuclide cardiac blood pool imaging and by contrast ventricu-lography; the aneurysm was successfully excised.     

Changes in the plasma concentrations of inhibin throughout the normal sheep oestrous cycle and after the infusion of FSH

A radioimmunoassay for inhibin was developed using a peptide containing the 1-26 amino acid sequence of the N-terminus of the alpha-chain of 32 kDa porcine inhibin as immunogen, and 125I-labelled tracer. Evaluation of this assay using Sephadex column chromatography, chromatoelectrophoresis and immunoblotting confirmed that it measured all forms of inhibin present in sheep follicular fluid and was suitable for measurement of inhibin in sheep plasma. There was no evidence of the presence of free alpha-subunit in either sheep follicular fluid or ovarian vein plasma. The concentration of inhibin in jugular plasma throughout the follicular and luteal phases of four ewes with ovarian autotransplants was measured. The ovarian secretion of inhibin and oestradiol were also measured simultaneously throughout the follicular phase in a spontaneous cycle and after infusion of NIH-oFSH-S14 at 10 micrograms/h for 48 h following premature luteal regression induced by prostaglandin. The results showed: (1) no change in the peripheral concentration of inhibin throughout the cycle except an increase related to the periovulatory increase in FSH and LH. (2) Following luteal regression, the concentration of FSH fell as the secretion rate of oestradiol increased. During this time there was no significant change in the peripheral concentration of inhibin or ovarian inhibin secretion rate. (3) Following the infusion of FSH there was a marked increase in the concentration of inhibin in both ovarian and peripheral plasma and an increase in ovarian inhibin secretion rate. (4) The calculated metabolic clearance rate of inhibin, 20.3 ml/min, is similar to that of FSH. We conclude that in the ewe the ovarian inhibin secretion rate is stimulated by FSH and, although inhibin may modulate the basal secretion of FSH, a change in its secretion does not account for the fall in FSH which occurs during the follicular phase of the sheep oestrous cycle.     

Oxidative stress and erythrocyte damage in Kenyan children with severe Plasmodium falciparum malaria

Anaemia causes significant morbidity in children with Plasmodium falciparum malaria, but the mechanism(s) are unclear. During malarial infection, increased reactive oxygen species (ROS) are generated that may contribute to erythrocyte damage and anaemia. This study measured the concentrations of alpha-tocopherol in plasma and erythrocyte membranes, and the percentage polyunsaturated fatty acid composition (%PUFA) (an indirect marker of ROS damage) in erythrocyte membranes in children with severe P. falciparum malaria from Kilifi, Kenya, and asymptomatic children from the same district. Malarial subjects were stratified into complicated malaria and malaria anaemia. Results demonstrated significant reductions in erythrocyte membrane alpha-tocopherol concentration (1.63 +/- 0.16 versus 3.38 +/- 0.18 micromol/mg protein; P < 0.001) and total %PUFA (30.7 +/- 0.49 versus 32.8 +/- 0.44% P < 0.005) for the malarial subjects (non-stratified) compared with controls. Malarial subjects showed a significant positive correlation between membrane alpha-tocopherol and haemoglobin concentrations (P < 0.005 r = 0.63 complicated malaria group; P < 0.05 r = 0.36 non-stratified data). There were no significant differences in plasma alpha-tocopherol concentration between malaria patients and controls. In conclusion, malarial infection may be associated with oxidative damage and reduced alpha-tocopherol reserve in the erythrocyte membrane, suggesting that local antioxidant depletion may contribute to erythrocyte loss in severe malaria. Erythrocyte membrane alpha-tocopherol appeared a better indicator of ROS exposure than plasma.     

Changing the model of radiography practice in the UAE: A snapshot of a profession in transition

IntroductionThis study forms part of a needs assessment in relation to the challenges United Arab Emirates (UAE) radiographers face as they move beyond the role of a technician, and their learning needs to facilitate role advancement. It presents a snapshot of the workforce in terms of qualifications, clinical experience, and responsibilities, as it transitions towards an Emirati, led profession. The results will aid the radiography workforce to embrace a broader role within medical imaging and radiographic practice in the UAE.MethodsAn electronically distributed cross-sectional study was conducted among radiographers in the UAE. The questionnaire captured radiographer demographics, qualifications, professional experience, postgraduate training, professional development plans, and their interest in future role developments.Results272 radiographers were invited to participate with a response rate of 68% (n = 185). Thirty-four (18%) radiographers were UAE nationals with the remainder educated overseas. BSc qualifications were held by 153 (82.7%) and had 6–20 years of experience. There were 12 masters’ qualified and two with doctoral qualifications. Modality vendors were significant providers of professional development. Improved job satisfaction and the development of an Emirati led radiography profession were identified as the main gains for role advancement by 171 (92.4%) respondents.ConclusionCurrently, UAE radiographers work within traditional professional boundaries focussing on image acquisition under direct radiologist supervision. At the same time, many respondents revealed they had embraced advanced practice roles after appropriate education and training.Implications for practiceThe findings suggest an Emirati led profession requires the creation of a distinct professional body to represent the interests of radiographers, more investment in postgraduate education, and the creation of a career structure that encompasses positive role development.