Ultrastable absolute-phase common-path optical profiler based on computer-generated holography

A new scanning common-path interferometric profiler capable of absolute-phase measurement is described. The key element is a computer-generated hologram, which acts as the beam-splitting element. Unlike most absolute phase systems, it can be made entirely common path with respect to piston microphonics and is thus exceptionally stable. In addition to operating in scanning mode, the optical configuration permits simultaneous operation as a single-shot phase measuring interferometer and is thus capable of simultaneous form and texture measurements. The operation and stability of the scanning profiler are demonstrated experimentally.

Transposed basilic vein versus polytetrafluorethylene for brachial-axillary arteriovenous fistulas

BACKGROUND

Both transposed basilic vein (BV) and polytetrafluorethylene (PTFE) upper arm arteriovenous fistulas (AVF) are common angioaccess operations. To evaluate the patency and complication rates after AVF, a concurrent series of patients was reviewed.

METHODS

Ninety-eight patients underwent brachial artery to axillary vein AVF: 30 BV and 68 PTFE. The PTFE grafts were performed in the standard fashion, whereas the basilic veins were translocated subcutaneously to the brachial artery.

RESULTS

Risk factors were similar between the two groups. Basilic vein AVF had better patency at 24 months (70% BV versus 46% PTFE, P = 0.023). The dialysis access complications were higher in the BV group (20%) versus PTFE (5%), but the PTFE group had a higher infection rate (10%) than BV (0%).

CONCLUSIONS

The primary and secondary patency rates were superior in the BV AVFs. The BV AVF preserves the venous outflow tract after AVF thrombosis for a future PTFE AVF operation.

Gene mapping in zebrafish using single-strand conformation polymorphism analysis

To exploit fully the power of the zebrafish system as a model for vertebrate development, it will be necessary to develop efficient tools for genomic analysis. In this report we have tested whether single-strand conformation polymorphism analysis (SSCP) can be utilized for gene mapping in zebrafish. Over 100 primer pairs derived from noncoding regions of known genes and partially characterized cDNAs were analyzed, and a polymorphism frequency of approximately 50% was detected in zebrafish strains used for genetic mapping studies. A subset of these polymorphic cDNAs was localized on the zebrafish map. SSCP thus represents an efficient strategy for mapping transcribed sequences with a high resolution in the zebrafish genome, which will facilitate the integration of existing zebrafish framework maps, the generation of a zebrafish EST map, and the application of alternative gene localization strategies such as comparative mapping.

Longitudinal changes associated with improvement in chronic fatigue patients

Tertiary care patients with chronic fatigue were followed for 2.5 years to determine if changes in physical and psychological status were associated with improvements in chronic fatigue, physical functioning, and return to work. Results indicated that improvement in psychological symptoms, DSM-III-R disorders, physical examination signs, and changes in whether the patient continued to meet criteria for chronic fatigue syndrome (CFS) were associated with recovery from fatigue, improved functioning, and return to work. Patients who never met CFS criteria or only met criteria at the initial assessment, reported improved physical functioning. Patients whose psychiatric disorders and physical examination signs were still present at a mean follow-up time of 2.5 years were more likely to have persistent fatigue and work disability. Loss of physical examination signs was a significant independent predictor of improved functioning and return to work. These results suggest that psychiatric status, as well as physical status, are associated with recovery from chronic fatigue.

Sensitivity of the rat hippocampal GABA(A) receptor alpha 4 subunit to electroshock seizures

The effects of one and five electroshock seizures on [3H]flunitrazepam binding, diazepam-insensitive (DIS) [3H]Ro 15-4513 binding, and levels of mRNA for GABA(A) receptor alpha1, alpha4, beta3 and gamma2 subunits were examined in rats. No changes in any parameter were observed in the CA1 region of hippocampus or in parietal cortex. However, a single seizure produced a rapid and transient increase of alpha4 mRNA in the dentate gyrus, without altering the expression of the other subunits. The putative alpha4 protein, as measured by DIS [3H]Ro 15-4513 binding, was also elevated in the dentate gyrus by a single shock. Repeated electroshock (48-h intervals) resulted in an enhanced response of the alpha4 subunit to the seizure. Neither one nor five seizures altered [3H]flunitrazepam binding.

Removing the 'estimates and guesses' from practice--evidence based tissue viability

The development of evidence based tissue viability is reviewed using the prevention and management of pressure sores as a specific example. Although data is limited, pressure sores may be more common at the end of the 1990's than they were fifteen years ago, despite changes in clinical practice. If evidence based tissue viability is to grow and mature, then two key obstacles must be overcome; changes in patient populations must be reflected within prevalence or incidence data (case-mix adjustment) so allowing interpretation of longitudinal changes in the occurrence of sores. Secondly, the efficacy and effectiveness of interventions such as pressure-redistributing beds and mattresses must be identified through rigorous and appropriate methodologies. Only through such steps can clinical skill be blended with research evidence to fully realise evidence based practice.

MRI measurement of brain tumor response: comparison of visual metric and automatic segmentation

An automatic magnetic resonance imaging (MRI) multispectral segmentation method and a visual metric are compared for their effectiveness to measure tumor response to therapy. Automatic response measurements are important for multicenter clinical trials. A visual metric such as the product of the largest diameter and the largest perpendicular diameter of the tumor is a standard approach, and is currently used in the Radiation Treatment Oncology Group (RTOG) and the Eastern Cooperative Oncology Group (EGOG) clinical trials. In the standard approach, the tumor response is based on the percentage change in the visual metric and is categorized into cure, partial response, stable disease, or progression. Both visual and automatic methods are applied to six brain tumor cases (gliomas) of varying levels of segmentation difficulty. The analyzed data were serial multispectral MR images, collected using MR contrast enhancement. A fully automatic knowledge guided method (KG) was applied to the MRI multispectral data, while the visual metric was taken from the MRI films using the T1 gadolinium enhanced image, with repeat measurements done by two radiologists and two residents. Tumor measurements from both visual and automatic methods are compared to "ground truth," (GT) i.e., manually segmented tumor. The KG method was found to slightly overestimate tumor volume, but in a consistent manner, and the estimated tumor response compared very well to hand-drawn ground truth with a correlation coefficient of 0.96. In contrast, the visually estimated metric had a large variation between observers, particularly for difficult cases, where the tumor margins are not well delineated. The inter-observer variation for the measurement of the visual metric was only 16%, i.e., observers generally agreed on the lengths of the diameters. However, in 30% of the studied cases no consensus was found for the categorical tumor response measurement, indicating that the categories are very sensitive to variations in the diameter measurements. Moreover, the method failed to correctly identify the response in half of the cases. The data demonstrate that automatic 3D methods are clearly necessary for objective and clinically meaningful assessment of tumor volume in single or multicenter clinical trials.

Evaluating critical thinking skills in a scenario-based community health course

This study evaluated the influence of a scenario-based community health course on the ability of senior nursing students (N = 54) to address complex problems seen in the community health setting. In addition, we examined whether students' scores on the Watson-Glaser Critical Thinking Appraisal (WGCTA) questionnaire would differ depending on the size of the educational institution they attended before enrollment in a school of nursing and whether the types of electives (liberal arts or science) previously taken would influence the scores. Sign ficant improvements were seen on the Interpretation and Evaluation subscales and on the total critical thinking score from pretest to posttest for students who completed the course. Also students who completed nursing prerequisites in midsized, 4-year universities (10,000 to 30,000 students) had higher pretest mean scores on the majority of WGCTA subscales than did other students.

Health Locus of Control in problem drinkers with and without liver disease

The purpose of this study was to investigate whether patients who developed alcoholic liver disease have more awareness of the link between their behaviour and subsequent health than patients with non-alcoholic liver disease and people with drink problems with no liver disease. This study included three groups of patients, alcoholic liver disease (ALD) (n=57), non-alcoholic liver disease (n=77), and problem drinkers with no liver disease attending a London community day treatment centre (ACCEPT) (n=115). Health locus of control differentiates people into two groups, health externals who are individuals who maintain that their health is largely determined by external factors, as opposed to health internals, who believe that their behaviour plays a major role in determining their subsequent health or illness. The results of the Health Locus of Control (HLC) scale administered to the above subjects suggested that the ALD group had limited insight into the relationship between their drinking and subsequent liver disease, compared to the ACCEPT group. It is suggested that alcoholic liver disease patients receive counselling as part of their total management.

Elder care among Mexican American families

This exploratory study describes caregiving experiences of elderly family members as perceived by eight Mexican American women caregivers and characterizes the ideas that some Mexican Americans have about elder care. A qualitative approach, using open-ended questions, revealed a cultural picture that reflected a very rich cultural heritage. This picture includes the importance of the family's responsibility to care for its elder members and describes family commitments that reach beyond obligation. It also portrays a complex system of cultural beliefs and values that are based on Mexican American tradition. The themes of reciprocity and point of reckoning emerged as two descriptive characteristics of the Mexican American family in the southwestern United States that form the basis for the restructuring of a woman's responsibilities during middle age. This study indicated that the bicultural lens through which the caregiver views the world may differ markedly from that of the elderly family member.

Mobility after hip fracture predicts health outcomes

OBJECTIVES

Balance and gait are essential to physical functioning and the performance of activities of daily living. The objective of this study was to determine the predictive value of a balance and gait test on subsequent mortality, morbidity, and healthcare utilization among older hip fracture patients.

DESIGN

A prospective study of hip fracture recovery.

SETTING

Patients with a new hip fracture admitted from the community to one of eight Baltimore hospitals and followed in their homes for 2 years postfracture.

PARTICIPANTS

A total of 306 patients with hip fracture, 65 years of age and older, who completed a gait and balance assessment at 2 months postfracture.

MEASUREMENTS

The relationship between gait and balance test performance at 2 months postfracture and mortality, physician visits, rehospitalizations, nursing home placement, and falls up to 24 months postfracture was assessed by Cox proportional hazards and least squares regression.

RESULTS

After adjusting for age, sex, race, and comorbidity, the balance score and the summary mobility score predicted mortality. A 17% increase in the risk of mortality was demonstrated for each unit decrease in the balance score (range 0-17), and a 10% increase was demonstrated for each decrease in the summary score (range 0-26). Unsteady balance during immediate standing, turning, sitting down, and rising from a chair were associated significantly with increased mortality. Poor balance, but not poor gait, was associated with an increase in hospitalizations up to 24 months postfracture. Both poor balance and poor gait were associated with nursing home placement, with 20% and 17% increased odds, respectively. Mobility did not predict future physician visits or falls.

CONCLUSIONS

These findings demonstrate that balance and gait are predictive of future health outcomes for older hip fracture patients.

Visual-imitative dissociation apraxia

Liepmann posited that, in right handers, the left parietal lobe contains movement formulas or representations. Therefore, performance failures may be induced by degraded representations, a failure of these representations to influence motor systems or a failure of stimuli to fully access these representations. Imitation may help the performance of subjects with degraded representations. However, patients who have impaired visual access to movement representations may perform more poorly with imitation than to verbal command. Trajectories of repetitive 'slicing' gestures made by a previously reported subject (Raymer et al.) with an infarction in the left visual association cortex (left occipital and inferior temporal lobe) that spared the parietal lobe were contrasted with those of three apraxic subjects with lesions that included the left parietal lobe and four non-brain-damaged control subjects. All subjects were asked to produce the gesture to verbal command and to imitation. Movements of the left hand, wrist, elbow and shoulder were digitized from neighboring views, reconstructed in three dimensions, and analysed graphically and numerically. The apraxic subjects with left parietal damage were unable to maintain the proper linearity and spatiotemporal attributes of their wrist motions and showed interjoint coordination deficits. Their deficits were most pronounced to verbal command, with their movements improving though remaining poorly performed when they imitated. The subject with the left occipital and inferior temporal lesion that spared parietal cortex, however, showed an opposite pattern. This subject exhibited close to normal performance when producing the movement to verbal command, but significant deficits when imitating.

The germinal center kinase gene and a novel CDC25-like gene are located in the vicinity of the PYGM gene on 11q13

Multiple endocrine neoplasia type 1 (MEN1) is tightly linked to the muscle-type glycogen phosphorylase (PYGM) gene in 11q13. This region of the human genome contains additional disease-related loci implicated in the development of insulin-dependent diabetes mellitus, familial paraganglioma type 2, spinocerebellar ataxia type 5, Bardet-Biedl syndrome and translocation t(11;17) described in B-cell non-Hodgkin's lymphoma. We approached cloning of candidate disease genes from 11q13 by large-scale genomic sequencing. We obtained > 106 kb of sequence around the PYGM gene and established a transcriptional map that includes: (i) two genes previously localized to 11q13, PYGM and a zinc-finger protein (ZFM1) gene; (ii) the germinal center kinase (GCK, human B-lymphocyte serine/threonine protein kinase) gene; (iii) a novel human CDC25-like (HCDC25L) gene; (iv) a dystrophia myotonica protein kinase-like (DMPKL) gene; and (v) a novel ubiquitously expressed gene of unknown function (germinal center kinase- neighboring gene, GCKNG).

Dissolution testing of soft shell capsules-acetaminophen and nifedipine

The problem of pelliculation of soft gelatin capsules on aging has been studied. Pelliculation frequently differs in soft shell capsules from hard shell capsules because of the larger mass of gelatin in the softshell dosage form. Two batches of nifedipine soft shell capsules are described. One batch failed in vivo testing and the other batch did not, after storage at 25 degrees C, yet both batches failed dissolution testing by the USP apparatus II method. The USP dissolution apparatus III-method, however, distinguished correctly between the batches. The study reported here was carried out with acetaminophen and was set up to establish whether the USP apparatus III testing method would be more suitable, and if so, what the most desirable dissolution medium should be. To create controlled pelliculation, samples were made with 0, 20, and 80 ppm of formaldehyde. The resulting capsules were subjected to ambient and accelerated storage and dissolution testing was carried out. It was found that the USP apparatus III method best reflected distinction between acceptable and substandard capsules.

Sequence and developmental expression of AmphiTob, an amphioxus homolog of vertebrate Tob in the PC3/BTG1/Tob family of tumor suppressor genes

Tob is a member of the PC3/ BTG1/Tob family of vertebrate tumor suppressor genes; its expression is known to inhibit proliferation of cells in vitro, but its possible roles during normal development have not been investigated previously. The present study concerns the structure and developmental expression of AmphiTob in an invertebrate chordate, amphioxus. This is the first investigation of any Tob gene during embryological development. The 311 amino acid AmphiTob protein is similar to vertebrate Tob but lacks the C-terminal PQ-rich domain of the latter. In early embryos of amphioxus, in situ hybridization first reveals AmphiTob expression in the hypoblast at the gastrula stage on the likely dorsal side of the embryo. During subsequent development, expression is seen in several tissues of the ectoderm, mesoderm, and endoderm. The most striking expression domains are in the developing somitic musculature and dorsal nerve cord. In the medial wall of each somite, AmphiTob is expressed strongly by cells destined to differentiate into the axial trunk muscles; this pattern persists until late in the larval stage, evidently because undifferentiated cells are continually becoming myogenic as the muscles grow. Nerve cord cells conspicuously transcribe AmphiTob from the late neurula until the early larval stage: Expression occurs in a few cells scattered along the nerve cord and in a group of cells located in the cerebral vesicle (in a region presumably homologous to the vertebrate diencephalic forebrain). During development, an intense and transitory transcription of AmphiTob may be an early event in cells exiting the cell cycle in preparation for differentiation.

Effect of long-term treatment with salmeterol on asthma control: a double blind, randomised crossover study

OBJECTIVES

To determine the effect of adding salmeterol 50 micrograms twice daily for six months to current treatment in subjects with asthma who control their inhaled corticosteroid dose according to a management plan.

DESIGN

A double blind, randomised crossover study.

SETTING

Nottingham.

SUBJECTS

101 subjects with mild or moderate asthma taking at least 200 micrograms twice daily of beclomethasone dipropionate or budesonide.

INTERVENTIONS

Salmeterol 50 micrograms twice daily and placebo for six months each, with a one month washout. Subjects adjusted inhaled steroid dose according to guidelines.

MAIN OUTCOME MEASURE

Reduction in inhaled steroid use, exacerbations of asthma, and use of oral steroids.

RESULTS

Data were available for 87 subjects. When compared with placebo salmeterol treatment was associated with a 17% reduction in inhaled steroid use (95% confidence interval 12% to 22%) with no significant difference in the number of subjects who had an exacerbation (placebo 25%, salmeterol 16%) or use of oral steroids. For secondary end points salmeterol treatment was associated with higher morning and evening peak expiratory flow and forced expiratory volume in one second; a reduction in symptoms, bronchodilator use and airway responsiveness to methacholine; and no effect on serum potassium concentration, 24 hour heart rate, or the final forced expiratory volume in one second achieved during a salbutamol dose-response study.

CONCLUSIONS

In subjects who adjusted their inhaled steroid treatment according to guidelines the addition of salmeterol 50 micrograms twice daily was associated with a reduction in inhaled steroid use and improved lung function and symptom control.