A comparison of bone mineral density in oligomenorrhoeic adolescents with polycystic ovaries and normal ovaries

We evaluated whether the presence of polycystic ovaries in adolescent girls as a cause of oligomenorrhoea and amenorrhoea would pose any protective effect against osteoporosis or low bone mineral density (BMD) compared with girls having similar menstrual dysfunction but normal ovaries. A cross-sectional observational study was done in consecutive girls, aged between 16 and 19 years, presenting to the adolescent gynaecology clinic with oligomenorrhoea or amenorrhoea. All patients underwent full hormonal profile assessment, pelvic ultrasound for ovarian morphology, bio-impedance estimation of body fat, and dual-energy X-ray absorptiometry and quantitative peripheral computed tomography scans to determine BMD in axial and appendicular skeletal sites. Polycystic ovaries were diagnosed according to ultrasound morphology. These were then compared with an age-matched eumenorrhoeic control group that had undergone the same evaluation. Of 45 patients with oligomenorrhoea or amenorrhoea, 14 (31%) were diagnosed to have polycystic ovaries, while the other 31 had normal ovaries. The control group consisted of 45 age-matched eumenorrhoeic girls. The group with normal ovaries had lower BMD at the lumbar spine and hip, as well as lower total tibial volumetric BMD, than the eumenorrhoeic controls, but there were no significant differences between the group with polycystic ovaries and eumenorrhoeic controls. We conclude that adolescents with oligomenorrhoea and amenorrhoea with normal ovaries had lower BMD than eumenorrhoeic ones, but those with polycystic ovaries had BMD values comparable to those of eumenorrhoeic controls despite their menstrual dysfunction.     

Manufacture and acoustical characterisation of a high-frequency contrast agent for targeting applications

The aim of this study was to develop and acoustically to optimise an ultrasonic contrast agent for research imaging applications at 40 MHz. A range of liposomal dispersions were manufactured and the mean backscatter power was measured using a Boston Scientific ClearView Ultra intravascular scanner with a 40 MHz, 2.5 Fr Atlantis SR Plus catheter. The scanner had been modified to allow access to the unprocessed ultrasound data, which were digitised, and the mean backscatter power was calculated over a region-of-interest centred at 2 mm from the transducer. Mean backscatter power was normalised to the data collected from a water-air interface. The effects of sonication and rapid shaking on six liposomal samples were also studied and this indicated that both techniques significantly reduced the size of the liposomes within the dispersions. Maximum mean backscatter power was measured for sonicated liposomal dispersions with 60% by weight of phosphatidylethanolamine. Moreover, this dispersion had greater mean backscatter power than sheep blood at 40 MHz.     

The effects of placental site on the arcuate artery flow velocity waveform

Eighty-three consecutive patients were studied to determine the effect of placental site on the arcuate artery flow velocity waveform. The resistance indices derived from signals obtained from the placental side of the uterus were significantly lower than those derived from signals obtained from the nonplacental side. Doppler studies of the uteroplacental circulation should be performed preferably with knowledge of the placental site.     

A labelled discrete choice experiment adds realism to the choices presented: preferences for surveillance tests for Barrett esophagus

Background  

Discrete choice experiments (DCEs) allow systematic assessment of preferences by asking respondents to choose between scenarios. We conducted a labelled discrete choice experiment with realistic choices to investigate patients' trade-offs between the expected health gains and the burden of testing in surveillance of Barrett esophagus (BE).     

Light chain nephropathy. Case report.

Two patients with light chain nephropathy are described. The diagnosis and management of this rare condition is discussed.     

Increased tumors but uncompromised fertility in the female descendants of mice exposed developmentally to diethylstilbestrol

Prenatal exposure to diethylstilbestrol (DES) has been associated with the subsequent development of reproductive tract abnormalities, including poor reproductive outcome and neoplasia, in experimental animals and humans. Experimental animal studies with chemical carcinogens have raised the possibility that adverse effects of DES may be transmitted to succeeding generations. To evaluate this possibility and to determine if there is a sensitive window of developmental exposure, outbred CD-1 mice were treated with DES during three stages of development: group 1 was treated on days 9-16 of gestation (2.5, 5 or 10 microg/kg maternal body wt), the time of major organogenesis; group II was treated once on day 18 of gestation (1000 microg/kg maternal body wt) just prior to birth; group III was treated on days 1- 5 of neonatal life (0.002 microg/pup/day). Female mice (F1) in each group were raised to sexual maturity and bred to control males. As previously reported, fertility of the F1 DES-exposed females was decreased in all groups. Female offspring (DES lineage or F2) from these matings were raised to maturity and housed with control males for 20 weeks. The fertility of these DES lineage female mice was not affected by DES exposure of their 'grandmothers'. DES lineage mice were killed at 17-19 and 22-24 months of age. An increased incidence of malignant reproductive tract tumors, including uterine adenocarcinoma, was seen in DES lineage mice but not in corresponding controls; the range and prevalence of tumors increased with age. Because uterine adenocarcinomas were seen in all three DES groups, all developmental exposure periods were considered susceptible to the adverse effects of DES. These data suggest that the reduced fertility observed in the DES F1 female mice was not transmitted to their descendants; however, increased susceptibility to tumor formation is apparently transmitted to subsequent generations.      

Adaptive time gain compensation for ultrasonic imaging.

The quality of ultrasonic images is often adversely affected by incorrect time gain compensation (TGC) settings. TGC set up by the operator is inadequate for two reasons: firstly, one gain function is unlikely to be appropriate for all the scan lines in an image and secondly, the operator may not have sufficient time or experience to optimise it. Adaptive processing offers a solution to this problem; it has the potential both to improve image quality and to let the operators make more effective use of their time. The literature concerned with adaptive TGC is briefly reviewed. A microcomputer-controlled system has been used to develop various algorithms for adaptive TGC. The algorithms operate in real-time and have been tested using a grey-scale test object, and clinically in routine abdominal and obstetric scanning. The imaging characteristics of each algorithm are determined largely by the value of a parameter beta, described in the text. It is concluded that adaptive TGC capable of applying a unique gain function to each part of the image can consistently produce better images than a single gain function set either automatically or manually.     

Nonpalpable breast lesion localization: limited efficacy of sonography

We attempted to use hand-held, high-resolution breast sonography to localize for biopsy 11 solid, nonpalpable lesions detected by mammography. Using sonography, we identified and localized only one of four lesions presenting as poorly defined masses and only one of seven lesions presenting as clusters of tiny calcifications. This 18% rate of success is too low to justify the use of sonography for all patients undergoing needle localization. Mammography remains the procedure of choice for localizing solid, nonpalpable breast masses and clustered calcifications.     

A clinical trial of automatic gain control in abdominal ultrasound

Large errors can occur with time gain compensation which is set up manually. These errors occur since basic time gain compensation usually assumes that the tissues being scanned are uniform. Automatic gain control has been somewhat neglected, probably due to a lack of clinical confirmation of its value and reliability. The trial of a commercial automatic gain control system in routine abdominal work has demonstrated that for 90% of patients it is capable of producing images as good as, or better than, the basic gain controls while involving the operator in fewer control manipulations.