Almost all methods of measuring residual volume of urine in the bladder of patients undergoing urologic assessment are biased to an unknown extent. The authors describe the application of an unbiased stereologic technique for estimating the volume of bladder urine known as the Cavalieri method. The method requires imaging of a series of systematic (ie, equally spaced) parallel sections through the bladder. Such data can be conveniently obtained with magnetic resonance (MR) imaging. If sampling begins at a position randomly chosen within the distance corresponding to the section interval, bladder volume is estimated without bias as the sum of the areas of the bladder sections on the images multiplied by the section interval. Computer-aided point-counting techniques represent an efficient means of obtaining the required section area estimates. Optimum sectioning and point counting densities for estimating bladder volume were established by analyzing detailed data sets obtained in five volunteers. It was shown that if an average of only 20 points were counted in each of only five systematic sections through the bladder, the volume of bladder urine was estimated with a coefficient of error of about 5%. By studying these five volunteers and an additional 13 with MR imaging and the Cavalieri method, the authors showed that the difference between the volume of urine in the bladder before and after micturition is unbiased (ie, shows no systematic difference) with respect to the volume of urine voided by the subjects.

Adult↗

PubMedDate not supplied

MRI analysis of lumbar intervertebral disc height in young and older populations.

Measurements of length and section area on MR images are made conventionally by the manipulation of a tracker ball to move a cursor to define end points or delineate boundaries. This operator-dependent method lacks the objectivity that computer-based image analysis techniques, such as edge-detection algorithms, can give. We describe an image analysis routine, based on earlier work by Vincent and Soille using algorithms of mathematical morphology, for automatically extracting the boundary of lumbar intervertebral discs on MR images. This is applied to the automatic measurement of the maximum disc space height and section area of non-degenerate intervertebral discs on MR images obtained for healthy male subjects of two distinct age ranges, ie, twenty 20- to 30-year-olds and twenty 50- to 60-year-olds. Throughout the levels L1 to L4, intervertebral disc height is found to be significantly greater (P = .0003 to .0161) in the older than in the younger age group. The data support a model of the spine in which the disc adopts a more concave form as a result of microfracturing of the end plates during adult life.

Adult↗

PubMedDate not supplied

The hippocampus and delayed recall: bigger is not necessarily better?

Healthy young female participants were tested on a measure of delayed verbal recall and then received volumetric Magnetic Resonance Imaging (MRI) scans. The analysis of the MRI scans focused on the volume of the hippocampus. Left hippocampal volume was negatively associated with the level of delayed verbal recall performance. This relationship was confirmed in further testing. This finding is consistent with a previous report of a similar relationship in healthy elderly individuals, but not in patients with Alzheimer's disease, in whom the opposite relationship was observed. An explanation of these findings in terms of impaired neural pruning of the hippocampus is advanced, whereby insufficient pruning of the hippocampus during childhood and adolescence (following adequate growth) may lead to reduced mnemonic efficiency.

Adult↗

PubMedDate not supplied

Estimation of brain compartment volume from MR Cavalieri slices.

PURPOSE: Recent theory has been developed to estimate volume from a systematic sample of tissue slices of a given thickness and to predict the corresponding error. Our goal was to check the error prediction formulas by resampling and to determine the minimum number of MR slices required to estimate the volumes of the cerebrum and of the compartments of gray matter (GM) and white matter (WM) with prescribed errors. METHOD: Our working data set comprised the GM and WM segmentations obtained from a paradigmatic high signal-to-noise ratio 3D spoiled GRASS MR volume data set for a single healthy human subject. The data were classified using a fuzzy clustering minimum distance algorithm. We thereby obtained a stack of 183 serial coronal slices of 1 mm thickness encompassing the whole cerebrum. Empirical resampling was carried out using the corresponding data vectors, and the theoretical error predictors were thereby checked for slice thicknesses of 1, 3, 9, and 27 mm, with a distance of 45 mm between slice midplanes. RESULTS: Irrespective of slice thickness, a minimum of 3, 5, and 10 slices provided estimates of the true total volume of GM and WM in the cerebrum with coefficients of error (CEs) of 10, 5, and 3%, respectively, where CE(V)% = 100 x SE(V)/V. For the cerebrum, a minimum of two, three, and four slices were required for CEs of the same precision. CONCLUSION: In combination with high signal-to-noise ratio and enhanced tissue contrast, Cavalieri slices are the most appropriate for MRI, they supply unbiased and highly efficient volume estimates of brain compartments. For a given number of slices, CE(V) decreases rapidly when the slices are thicker than the gaps between them; when the slices are thinner than the gaps, then CE(V) is similar to that in the situation when the slice thickness is zero.

Brain↗

PubMedDate not supplied

Evaluation of innovations in nursing practice: report and discussion.

AIM: To assess whether a pilot study conducted in the UK achieved its objective to reduce admissions to hospital and bed days in patients identified as suitable recipients of case management by community matrons. BACKGROUND: The Department of Health has advocated the use of nurse-led case management to improve the coordination of care and prevent inappropriate hospital admissions. METHOD: 66 patients and another 66 controls were identified for the 'Evercare' caseload according to criteria set by United Healthcare. Admissions data for the six months after entry into the study were collected from the hospital information system. FINDINGS: admission rates in both the control and intervention group decreased over time and there was no significant difference in rates between the two groups at six months. There was no demonstrable effect on length of stay either. Users were satisfied with the service and nurses cited several clinical stories implying benefits for individual patients.

Aged↗

PubMedDate not supplied

Student internships provide extra hands, enhanced credibility for health promotion.

Explore the source record for details and available documents.

Education Department, Hospital↗

PubMedDate not supplied

The ethane dimethanesulfonate-induced decrease in the fertilizing ability of cauda epididymal sperm is independent of the testis.

Several decades ago it was reported that when adult male rats were exposed to a single injection of 50 mg/kg body weight ethane dimethanesulfonate (EDS) and mated with untreated females, average litter size was significantly reduced as early as 2 weeks later. Recently, we demonstrated that EDS exerts multiple effects in the epididymis of adult rats. Some of these effects were independent of reduced serum testosterone (T) levels. Later we found that EDS has direct effects on epididymal epithelial cells in vitro. Herein, we sought to determine whether EDS perturbs the fertilizing ability of cauda epididymal sperm. Four days after exposure to 50 mg/kg EDS, sperm from the proximal cauda epididymidis were inseminated into adult receptive females in utero; on the next day the percentage of fertilized eggs was determined. Exogenous T administration and castration were used to determine what role, if any, androgen deprivation and the testis had on the fertilizing ability of proximal cauda epididymal sperm. Sperm motion parameters, serum T, T in the caput/corpus epididymidis, and detergent-extracted sperm protein were evaluated and correlated with fertilizing ability. We found that both castration and EDS exposure significantly compromised the fertilizing ability of sperm in proximal cauda epididymidis 4 days after exposure. Exogenous T, sufficient to maintain serum T, completely restored the fertilizing ability of sperm following castration, but not after EDS exposure. Moreover, exogenous T failed to restore fertilizing ability when castrated animals were exposed to EDS. Thus, the effects that EDS exerts on sperm maturation in vivo are independent of the testis. Finally, the only endpoint that was well correlated with fertilizing ability was the relative amount of an acidic 18-kDa sperm protein.

Animals↗

PubMedDate not supplied

The gut and the skin.

Many disorders of the gastrointestinal tract have cutaneous manifestations. In this article the skin signs and diseases that are most commonly associated with gastrointestinal disease are described.

Adenocarcinoma↗