Detection of nucleotide-specific CRISPR/Cas9 modified alleles using multiplex ligation detection

CRISPR/Cas9 genome-editing has emerged as a powerful tool to create mutant alleles in model organisms. However, the precision with which these mutations are created has introduced a new set of complications for genotyping and colony management. Traditional gene-targeting approaches in many experimental organisms incorporated exogenous DNA and/or allele specific sequence that allow for genotyping strategies based on binary readout of PCR product amplification and size selection. In contrast, alleles created by non-homologous end-joining (NHEJ) repair of double-stranded DNA breaks generated by Cas9 are much less amenable to such strategies. Here we describe a novel genotyping strategy that is cost effective, sequence specific and allows for accurate and efficient multiplexing of small insertion-deletions and single-nucleotide variants characteristic of CRISPR/Cas9 edited alleles. We show that ligation detection reaction (LDR) can be used to generate products that are sequence specific and uniquely detected by product size and/or fluorescent tags. The method works independently of the model organism and will be useful for colony management as mutant alleles differing by a few nucleotides become more prevalent in experimental animal colonies.

Nasal cytokine responses to natural colds in asthmatic children

Background

The mechanisms by which viruses induce asthma exacerbations are not well understood.

Objective

We characterized fluctuations in nasal aspirate cytokines during naturally occurring respiratory viral infections in children with asthma.

Methods

Sixteen children underwent home collections of nasal aspirates when they were without cold symptoms and again during self‐reported respiratory illnesses. The presence of viral infection was ascertained by multiplex PCR. Cytokines were measured using multiplex immune assay. mRNA expression for selected markers of viral infection was measured using RT‐PCR. A cumulative respiratory symptom score was calculated for each day of measurement. Generalized estimated equations were used to evaluate associations between viral infection and marker elevation, and between marker elevation and symptom score.

Results

The 16 patients completed a total of 37 weeks of assessment (15 ‘well’ weeks; 22 self‐assessed ‘sick’ weeks). Viral infections were detected in 3 of the ‘well’ weeks and 17 of the ‘sick’ weeks (10 rhinovirus, three coronavirus, two influenza A, two influenza B, two respiratory syncytial virus, one parainfluenza). Compared to virus‐negative well weeks, nasal aspirate IFN‐γ, CXCL8/IL‐8, CXCL10/IP‐10, CCL5/RANTES, CCL11/eotaxin‐1, CCL2/MCP‐1, CCL4/MIP‐1β, CCL7/MCP‐3, and CCL20/MIP3α protein levels increased during virus‐positive sick weeks. Only a subset of cytokines (IFN‐γ, CXCL8, CCL2, CCL4, CCL5, and CCL20) correlated with self‐reported respiratory tract symptoms. While many aspirates were dilute and showed no mRNA signal, viral infection significantly increased the number of samples that were positive for IFN‐λ1, IFN‐λ2/3, TLR3, RIG‐I, and IRF7 mRNA.

Conclusions and clinical relevance

We conclude that in children with asthma, naturally occurring viral infections apparently induce a robust innate immune response including expression of specific chemokines, IFNs, and IFN‐responsive genes.

Task-dependent interactions between dopamine D2 receptor polymorphisms and L-DOPA in patients with Parkinson's disease

Variants in genes regulating dopamine transmission affect performance on tasks including working memory and executive function as well as temporal processing and sequence learning. In the current study, we determined whether a dopamine D2 receptor DNA sequence polymorphism interacts with L-DOPA during motor tasks in patients with Parkinson's disease (PD). Forty-five PD patients were genotyped for the DRD2 polymorphism (rs 1076560, G>T). Patients performed an explicit motor sequence learning task and the grooved pegboard test in both ON and OFF L-DOPA states. For motor sequence learning, DRD2 genotype mediated L-DOPA effects such that L-DOPA associated improvements were only observed in the minor T allele carriers (associated with lower D2 receptor availability, t10=-2.71, p=0.022), whereas G homozygotes showed no performance change with L-DOPA. For the grooved pegboard test, performance improved with L-DOPA independent of patients' DRD2 genotype. Collectively these results demonstrate that common DRD2 allelic differences found in the human population may explain how dopamine differentially contributes to performance across tasks and individuals.

Martial arts as sport and therapy

The term Martial Arts is often used as general phrase to describe many of the combat arts, which have developed in eastern cultures over the past millennium. This paper reviews the Martial Arts from the original context of a trio of life skills. This trio includes the healing arts such as acupuncture, the self-exploration arts such as yoga, and the vital life skills such as meditation. As Martial Arts suggests the waging of combat, the origins of the most common combat arts are reviewed, with an overview of the difference between the hard and the soft styles. The arts developed not only in the eastern, but also in all parts of the world, with references of these types of combats arts in the writings of the ancient Egyptians and Greeks. In modern times, the combat arts are performed for both exercise and sport. A review of the injuries that occur, and the health benefits that might be expected are discussed. A review of the medical literature that demonstrates some of these health benefits is included, with Tai Chi Chuan as the most studied of these. The health benefits discussed include strengthen and self-efficacy of the elderly, reduced falls, increased exercise capacity, and benefits to the immune system and autonomic nervous system. The paper emphasized the breadth of the Martial Arts and the import of these to the sports and health community.

Rehabilitation outcomes of cardiac and non-cardiac anoxic brain injury: a single institution experience

OBJECTIVE

To compare the functional outcomes of patients with anoxic brain injury (ABI) due to cardiac and non-cardiac aetiologies.

DESIGN

Retrospective chart review over 4 years.

SETTING

Freestanding rehabilitation hospital.

PARTICIPANTS

Thirteen patients with cardiac ABI and 13 patients with non-cardiac ABI.

INTERVENTION

Comprehensive, multi-disciplinary inpatient rehabilitation services.

MAIN OUTCOME MEASURES

Rehabilitation hospital length of stay (LOS) and cost; Functional Independence Measure (FIM) scores and its various sub-sets on admission and discharge; FIM efficiency and change; and discharge disposition.

RESULTS

Patients with cardiac ABI were similar in gender and ethnicity when compared to patients with non-cardiac ABI but were older (average age 52 vs 42) with a higher percentage of cardiac patients married (77% vs 39%). No statistically significant differences were found between the two groups on all sub-sets of the FIM on admission and discharge as well as the different FIM efficiencies. However, there was a trend for the cardiac ABI patients to have a greater efficiency in improving mobility during rehabilitation when compared to non-cardiac ABI patients. The rehabilitation hospital LOS was approximately 28 days less for patients with cardiac ABI (41.49 vs 69.84 days), but this difference was not statistically significant (p=0.26). The mean rehabilitation cost for patients with cardiac ABI was approximately $14,000 less than that for those with non-cardiac ABI ($44,181 vs $58,187). This difference was not statistically significant (p=0.15). Cardiac ABI patients were more likely to be discharged directly to home from rehabilitation when compared to non-cardiac ABI patients (p=0.06).

CONCLUSION

This pilot study demonstrates some differences in the recovery patterns of patients with ABI who had a cardiac aetiology and those who had non-cardiac aetiologies. While both groups experienced similar progress during rehabilitation, those with cardiac ABI made gains with a shorter LOS and less rehabilitation costs when compared to non-cardiac ABI patients. These data suggest a trend towards greater cost and length of stay for patients with ABI who had non-cardiac aetiologies.

An integrated microfluidic device for influenza and other genetic analyses

An integrated microfluidic device capable of performing a variety of genetic assays has been developed as a step towards building systems for widespread dissemination. The device integrates fluidic and thermal components such as heaters, temperature sensors, and addressable valves to control two nanoliter reactors in series followed by an electrophoretic separation. This combination of components is suitable for a variety of genetic analyses. As an example, we have successfully identified sequence-specific hemagglutinin A subtype for the A/LA/1/87 strain of influenza virus. The device uses a compact design and mass production technologies, making it an attractive platform for a variety of widely disseminated applications.

Effect of implementation of safety measures in tae kwon do competition

BACKGROUND

Previous reviews of tae kwon do (TKD) tournaments have documented injury rates of 25/1000 to 12.7/100 athlete exposures. Most injuries have been reported to be to the head and the neck and are occasionally very serious. Many of these studies involved high level TKD competitions with minimal safety precautions. Recently, safety measures have been implemented in many TKD competitions.

OBJECTIVE

To evaluate retrospectively the incidence of injuries in TKD competitions involving a wide range of participants and featuring extensive safety precautions.

METHODS

A total of 2498 participants ranged in age from 18 to 66, included both men and women, and ranged in rank from yellow to black belt. Traumas, defined as any event requiring interaction with medical staff, were documented with respect to mechanism, diagnosis, treatment, and follow up recommendations. An injury was defined as a trauma that prevented a contestant from resuming competition on the day that the trauma occurred, according to National Collegiate Athletic Association criteria.

RESULTS

The injury rate was 0.4/1000 athlete exposures. This is lower than reported in previous studies of TKD tournaments and in many other sports.

CONCLUSION

TKD tournaments that emphasise limited contact, protective equipment, and medical supervision are relatively safe and compare favourably with other sports.

Genetic polymorphisms in mouse genes regulating age-sensitive and age-stable T cell subsets

To see whether genetic polymorphisms regulate inter-individual differences in T cell subset levels, we have conducted a genome scan in two populations of mice, bred as the progeny of a cross between CB6F1 females and C3D2F1 males. The data document quantitative trait loci (QTL) with statistically significant effects on CD4, CD8, and CD8 memory T cells, and on subsets of CD4 and CD8 T cells that express P-glycoprotein. Some of the loci detected were robust, in the sense that they produced effects of similar size both in mated female mice, and in a population that included male and female virgin animals. Some of the effects were stable, in that they were apparent at both 8 and 18 months of age, but others were age-specific, showing effects either at 8 or at 18 months but not at both ages. Genes that had an effect on the same T cell subset were in almost all cases additive rather than epistatic, and their combined effects could produce large overall effects, leading in the most dramatic case to a two-fold difference in CD8 memory cells. The analysis also documented two QTL, on chromosomes 4 and 13, that regulate an age-sensitive composite index of T cell subset pattern which has been shown previously to be a predictor of life expectancy in these mice. The analysis thus reveals both subset-specific genes and others which modulate the overall pattern of age-sensitive changes in T cell subset distributions.

A survey of anorexia nervosa using the Arabic version of the EAT-26 and "gold standard" interviews among Omani adolescents

OBJECTIVE

The purpose of this study was to assess the validity of the Eating Attitude Test (EAT) in identifying the presence and severity of eating pathology in male and female Omani urban adolescents and to establish cut-off scores that matched those of anorexia identified by gold standard interviews without fear of fatness criteria.

METHODS

Both females (n=126) and males (n=136) were screened using the Arabic version of the EAT-26 and interviewed using a semi-structured, Composite International Diagnostic Interview (CIDI) in order to investigate the relationship between false positives and false negatives at various EAT-26 cut-off points. A receiver operating characteristics (ROC) curve was calculated to discriminate the power of the EAT-26 for every possible threshold score.

RESULTS

The EAT-26 identified 29% of the subjects as probable anorexic cases as against 9.5% identified during the structured interview based on the anorexia gold standard (32% males and 68% females). The sensitivity and specificity of the EAT-26 were respectively 24% and 69.6%. When using the ROC curve, a cut-off score of 10 gave the best compromise between sensitivity (64%) and specificity (38%).

DISCUSSION

Although the EAT-26 is the most widely used screening instrument in cross-cultural studies, it does not appear to be reliable in identifying probable cases of anorexia among Omani adolescents. The use of a gold standard interview without fat phobia criteria indicated that the rate of anorexia nervosa may be more prevalent among males than previously estimated. This intriguingly high preponderance of males is discussed in terms of prevailing demographic trends in Oman.

Mobility, diffusion and dispersion of single-stranded DNA in sequencing gels

Electrophoresis of single-stranded DNA in denaturing polyacrylamide gels is presently a standard procedure for the sequencing of DNA fragments. A thorough understanding of the factors that determine the resolution of DNA fractionated in polyacrylamide gels is necessary to optimize the performance of DNA sequencers. Significant research on the mobility of double-stranded (ds)DNA molecules in agarose and polyacrylamide gels has been performed, and the phenomenon of band broadening of single-stranded (ss)DNA fragments in DNA sequencing gels has received attention only recently. In this paper, we present a detailed study of mobility, diffusion and dispersion of ssDNA in sequencing gels as a function of molecular size, gel concentration and electric field strength. DNA mobility is shown to be essentially independent of electric field in the range of 0-60 V/cm. The band broadening is greatly enhanced in the presence of an electric field and the dispersion coefficient (DE) can be an order of magnitude higher than the field-free diffusion coefficient. The measured migration parameters approximately follow the predictions of the biased reptation including fluctuations (BRF) theory. However, deviations due to nonidealities of the separation conditions are observed. The measured migration parameters can be used to optimize the performance of separation systems.

Post-stroke violent adventitial movement responsive to levo-dopa/carbi-dopa therapy

Previous reports in the literature concerning cerebrovascular accident have illustrated cases of post-stroke tremor. Treatments of these studies have varied. Trials of levo-dopa have been reported in two such cases. This case study reports on a case of a patient with a left thalamic, left superior cerebellar artery infarction with a lacunar infarction in the basal ganglia. The patient developed a violent tremor/movement disorder which was unresponsive to haloperidol. With this failure, and with the evidence of a basal ganglion lesion, levo-dopa/carbi-dopa was introduced as an intervention. The amplitude of the tremor was dramatically reduced, with protective devices removed, and with complete cessation of the tremor at rest. The medication was withdrawn and reintroduced with a reduction and subsequent resolution of the symptoms. A discussion of the previous studies of movement disorder with cerebrovascular accident is included.

Using talking lights to assist brain-injured patients with daily inpatient therapeutic schedule

OBJECTIVES

To test the ability of patients with brain injury to use a patient locator and minder (PLAM) system to assist in their adherence to therapy schedules.

PARTICIPANTS

Five patients with acquired brain injury who were inpatients on an acute rehabilitation floor of a rehabilitation hospital.

MEASURES

The number of human prompts necessary to direct a patient to, and ensure arrival at, a scheduled therapy destination and the proportion of therapy sessions requiring no prompting was measured both before and after the introduction of the PLAM system.

RESULTS

With the PLAM system, the average number of human prompts dropped by more than 50%, and the number of sessions requiring no prompting increased from 7% to 44%.

CONCLUSION

The PLAM system described in this article seems feasible and useful for patients with acquired brain injury in assisting them with arrival at their therapy destinations without the assistance of staff.

On-chip thermopneumatic pressure for discrete drop pumping

A class of "lab-on-a-chip" devices use external air pressure for pumping discrete drops in a microchannel network. External air connectors can be cumbersome and are real-estate intensive. We have developed an on-chip technique to generate pressures required for metering and pumping of nanoliter-volume discrete drops. This is achieved by heating of trapped air in a pressure-generating chamber. The pressure-generating chamber is connected to the point of pressure application in the liquid-conveying microchannel through an air-delivery channel. The trapped air volume on the order of 100 nL is heated by resistive metal heaters by tens of degrees celcius to generate air pressures on the order of 7.5 kN/m2. The rate of discrete drop pumping is electronically controlled in the microchannel device by controlling the rate of air heating. Flow rates on the order of 20 nL/s are obtained in the microchannel (300 microns x 30 microns) by heating the air chamber at the rate of approximately 6 degrees C/s. In this paper, we describe the design, fabrication, and operation of this new technique of generating on-chip air pressure, used for metering and pumping nanoliter discrete drops in microchannels.

Monolithic capillary electrophoresis device with integrated fluorescence detector

A monolithic capillary electrophoresis system with integrated on-chip fluorescence detector has been microfabricated on a silicon substrate. Photodiodes in the silicon substrate measure fluorescence emitted from eluting molecules. The device incorporates an on-chip thin-film interference filter that prevents excitation light from inhibiting the fluorescence detection. A transparent AZO conducting ground plane is also used to prevent the high electric fields used for the separation from interfering with the photodiode response. Separations of DNA restriction fragments have been performed in these devices with femtogram detection limits using SYBR Green I intercalating dye.

Electrophoresis in microfabricated devices using photopolymerized polyacrylamide gels and electrode-defined sample injection

Microfabrication techniques have become increasingly popular in the development of the next generation of DNA analysis systems. While significant progress has been reported by many researchers, complete microfabricated integrated DNA analysis devices are still in the earliest stages of development. Most miniaturized analysis systems have incorporated noncross-linked polymer solutions as the separation medium of choice and the operation of these systems necessitates the use of high electric fields and long separation lengths. In this paper, we present two techniques that may help alleviate this problem and accelerate the development of the so-called 'lab-on-a-chip' systems. We present the use of photodefinable polyacrylamide gels as a sieving medium for DNA electrophoresis. These gels offer the significant advantages of faster curing times, locally controlled gel interface, and simpler handling over chemically polymerized gels. We also introduce an electrode-defined sample compaction and injection technique. This technique helps achieve sample compaction without migration into the gel and offers significant control over the size and application of the sample plug. The use of these technologies for double-stranded DNA separations in microfabricated separation systems is demonstrated.

Can toe-walking contribute to stiff-legged gait?

OBJECTIVE

Spastic paretic stiff-legged gait, defined as reduced knee flexion in swing, has previously been attributed solely to spastic quadriceps activity. In earlier work, the authors suggested that reduced knee flexion in swing can be attributed to other indirect factors, such as poor hip flexion and abnormal foot-ankle function during gait. The present study was undertaken to determine whether toe-walking, which often occurs in conjunction with stiff-legged gait, in and of itself, might explain some of the reduced knee flexion in swing.

DESIGN

An analysis was performed of three-dimensional kinematic data collected from able-bodied subjects while walking on their toes vs. normal heel-toe walking.

RESULTS

Peak knee flexion was reduced significantly compared with normal heel-toe walking (42.2+/-8.9 degrees toe-walking vs. 59.2+/-5.7 degrees heel-toe walking; P < 0.00001).

CONCLUSIONS

This finding, which occurred when controlling for walking speed, may be clinically relevant for patients who have both a toe-walking and a stiff-legged gait pattern. Some of the reduced knee flexion in swing may be merely a consequence of toe-walking, rather than a result of other causes, such as intrinsic spasticity or abnormal muscle firing about the knee.

Naltrexone: effects on motor function, speech, and activities of daily living in a patient with traumatic brain injury

Evidence from many studies has suggested that endogenous opioid peptides participate in a number of pathophysiological responses to brain injury. This provides the rationale for the use of opioid antagonists for the enhancement of neural recovery after brain injury. A case is presented of an 18-year-old male who had loss of consciousness for 1 month after a severe brain injury. Three months of intensive rehabilitative therapies did not change his functional status. A trial of naltrexone was given while his performance in mobility, speech and overall Functional Independence Measure (FIM) scores were monitored. Results indicate an accelerated improvement in functional status and statistically improved FIM score.

Prevention of deep venous thrombosis: overview of available therapy options for rehabilitation patients

The assessment, diagnosis, and treatment of deep venous thrombosis remain a significant problem facing hospitalized patients. The threat of thromboembolism is no less significant, perhaps more so, when patients are discharged from the hospital for subsequent care in rehabilitation units. These patients can have multiple risk factors that predispose them to a high risk of a thromboembolic event. It is clearly evident that thromboembolic prophylaxis is warranted, as it provides both positive clinical and economic outcomes. A variety of nonpharmacologic and pharmacologic strategies can be used to decrease the risk of developing deep venous thrombosis. The method of thromboembolic prophylaxis used should be based on individual patient characteristics and documented clinical and economic advantages. The purpose of this article is to review currently available thromboembolic prophylaxis measures and the implications of their use by rehabilitation physicians.

Nanoliter liquid metering in microchannels using hydrophobic patterns

Nanoliter-sized liquid drops can be accurately metered inside hydrophilic microchannels using a combination of hydrophobic surface treatment and air pressure. The technique involves spontaneously filling the microchannels up to a hydrophobic region and splitting a liquid drop by injecting air through a hydrophobic side channel. The hydrophobic regions are fabricated by using a patterned metal mask on a substrate. The patterned substrate is immersed in an isooctane solution containing 1H,1H,2H,2H-per-fluorodecyltrichlorosilane to form hydrophobic patches on the exposed surface. Stripping the metal mask leaves the hydrophobic patches and restores the hydrophilic substrate surface. Precise and accurate liquid volumes, ranging from 0.5 to 125 nanoliters, have been metered using this technique. Theoretical predictions of the pressure needed to meter drops compare well with the experimental values.

Electronic memory aids for outpatient brain injury: follow-up findings

The introduction of highly portable computers extends the range of tools potentially useful to persons with functional impairments of prospective memory resulting from brain injury. This study reviews the experience of 12 patients with brain injury undergoing outpatient treatment using palmtop computers to assist with memory dependent activities in their everyday lives. During the initial supervised trial period, each was provided a palmtop computer based memory aid capable of generating audible and visible reminder cues. Subsequently, patients were contacted for follow-up between 2 months and 4 years after initial trial usage, and surveyed as to the utility of the computer. Nine patients found palmtop computers were useful during supervised trials. Seven of nine patients actually continued to use such devices after the usage trials had ended. Experience with this technology has shown it to be useful in a high proportion of patients for assisting with memory dependent functions.

Dosing practices of physicians for anticoagulation with warfarin during inpatient rehabilitation

OBJECTIVE

To determine the percentage of international normalized ratios (INRs) maintained within the therapeutic range for patients receiving chronic anticoagulation treatment with warfarin during inpatient rehabilitation.

DESIGN

A consecutive, 4-month, retrospective chart review of all patients receiving oral anticoagulation treatment was conducted in a large academic rehabilitation center. The percentage of INRs within and out of the therapeutic range, frequency of blood samples, length of therapy, and warfarin dose prescribed by physicians were calculated. A total of 181 patients receiving chronic anticoagulation treatment were identified. A total of 3,709 blood samples were analyzed. In 74 patients, the primary physician recommended a therapeutic range (Group 1). In the remaining 107 patients, no therapeutic range was specified, and a target INR range of 2.0-3.0 was assumed (Group 2).

RESULTS

In Group 1, the INRs were in the recommended range in 38.2% of all blood samples. In Group 2, 37.6% of all blood drawn was within an INR range of 2.0-3.0. Statistical analysis showed that no better accuracy was obtained when the INR range was predefined by a physician (Group 1) or assumed to be in the 2.0-3.0 range (Group 2; P = 0.839).

CONCLUSIONS

Despite frequent physician monitoring, this study demonstrates the difficulty in maintaining INRs within therapeutic ranges for patients receiving oral anticoagulation. An overall tendency for underdosing is observed. Improvement is necessary, given the high morbidity and mortality associated with insufficient anticoagulation in rehabilitation inpatients.

Compensatory advantages of toe walking

OBJECTIVES

The study's hypothesis is that toe walking requires less peak muscle strength distally about the ankle and knee compared with normal heel-toe walking and thus may have compensatory advantages for patients with upper motor neuron injury and distal muscle weakness.

DESIGN

Motion analysis and force platform data were collected in able-bodied subjects during toe walking and normal walking. Sagittal plane joint torques reflecting muscle force requirements and joint powers reflecting nonisometric muscle contraction were compared between the two conditions using paired t tests, applying a Bonferroni correction for multiple comparisons.

SETTING

A gait laboratory.

SUBJECTS

Seventeen able-bodied adults, 9 of whom were ballet dancers.

MAIN OUTCOME MEASURES

Peak hip, knee, and ankle joint torque and power variables during walking.

RESULTS

Peak ankle plantarflexor torque and ankle power generation during terminal stance and preswing were reduced (p<.001), as compared with normal heel-toe walking. The normal ankle dorsiflexor torque at initial contact-and the knee extensor torque and knee power generation during loading response were all essentially absent during toe walking. Hip extensor torque and hip power generation during the loading response phase were greater for toe walking (p<.001).

CONCLUSION

Toe walking may require less ankle plantarflexor, ankle dorsiflexor, and knee extensor strength than normal heel-toe walking and thus may have compensatory advantages for patients with upper motor neuron injury and distal lower extremity weakness.

Subjective swelling: a new sign for carpal tunnel syndrome

This single-blinded, randomized cohort study of 186 patients was conducted to determine whether the subjective complaint of swelling of the hand or wrist is associated with the diagnosis and/or prognosis of carpal tunnel syndrome. All patients were referred for splinting with a presenting clinical diagnosis of carpal tunnel syndrome from outpatient specialty clinics, including orthopedics, rheumatology, and neurology. Patients were assessed before splinting for the complaint of subjective swelling and underwent a clinical examination including Phalen testing and carpal compression testing. In addition, 211 of the 290 joints underwent electrodiagnostic testing by the end of this study. Among the 211 joints for which electrodiagnosis was used, a chi2 analysis was performed to determine the correlation among subjective swelling, the Phalen and carpal compression tests, and the electrodiagnostically verified carpal tunnel syndrome. Two weeks after splinting, an assessment was made of the subjective response to splinting. Chi2 analysis was then performed to assess the correlation among the Phalen test, carpal compression test, and nerve conduction study results and the symptom of subjective swelling at presentation with that of response to splinting. Subjective swelling of the hand showed a trend toward association with electrodiagnostic results (although this finding was not statistically significant) and proved to be significantly correlated with a poor clinical response to splinting. Positive electrodiagnostic findings were significantly, though positively, correlated with pain relief from splinting. This study, therefore, introduces the complaint of subjective swelling of the affected hand as an important diagnostic and prognostic symptom for the assessment and treatment of carpal tunnel syndrome.

Effects of aging on motor-unit control properties

It was hypothesized that the age-related alterations in the morphological properties of a motor unit would be accompanied by modifications in the control aspects of the motor unit, as either an adaptive or compensatory mechanism to preserve smooth force production. In specific, the objective of the study was to investigate the age-related alterations in the concurrent firing behavior of multiple motor units in the first dorsal interosseous (FDI) muscle in isometric contractions at 20 and 50% of the subject's voluntary contraction level. Analysis of the data collected from 10 young (24-37 yr of age) and 10 elderly (65-88 yr of age) subjects led to three novel observations regarding the firing behavior of aged motor units. 1) Among elderly subjects, there is a decrease in the common fluctuations that are observed among the firing rates of motor units in the young. 2) The relationship observed between the firing rate and recruitment threshold of young subjects is disturbed in the elderly. Although in young subjects, at any point in a given submaximal contraction, earlier recruited motor units have higher firing rates than later-recruited units; in aged subjects this dependency of firing rate on recruitment rank is compromised. 3) The progressive decrease observed in the firing rates of concurrently active motor units in constant-force contractions in the young is not seen in the aged. In addition to these original findings, this study provided support for earlier reports of 1) decreased average firing rates probably reflecting the slowing of the muscle, 2) a shift in recruitment thresholds toward lower force levels in line with the shift toward type I fibers, and 3) multiphasic action potential shapes indicative of the reinnervation process that takes place during aging. Taken as a whole, these findings indicate significant age-related modifications in the control properties of human motor units.

Treatment with amantadine potentiated motor learning in a patient with traumatic brain injury of 15 years' duration

This study sought to determine whether pharmacotherapy with amantadine potentiates motor recovery in an 18-year-old man with traumatic brain injury (TBI) of 15 years' duration. This uncontrolled single-case multiple-baseline design allowed preliminary evaluation of amantadine within the context of standard data-collection procedures on the TBI unit. Measurements tracked speed of wheelchair propulsion, wheelchair transfer, donning shirt, and inserting pegs into holes. Data were collected during a 3-week practice period, followed by a 6-week period of practice plus daily treatment with amantadine. The rate at which performance improved was significantly increased with drug treatment in the wheelchair transfer task. There was a statistically insignificant trend toward improvement in donning shirt. Amantadine did not appear to potentiate recovery in the wheelchair propulsion or peg placement tasks. The results suggest that amantadine facilitates some measures of motor recovery in chronic brain injury. Further trials are warranted to investigate this issue.

An algorithm to assess stiff-legged gait in traumatic brain injury

Spastic paretic stiff-legged gait is a frequently encountered gait problem in patients with traumatic brain injury, as well as in many other patients with upper motor neuron disease. Formerly, spasticity of the quadriceps was considered to be the sole cause of stiff-legged gait. Quantitative gait analysis, however, may implicate hip flexor weakness or poor ankle mechanics as the cause of stiff-legged gait. We discuss the use of an algorithm to evaluate stiff-legged gait in traumatic brain injury using a quantitative gait analysis system such that the specific etiology of stiff-legged gait can be identified and can serve as the basis of a treatment plan.

Utility of a microcomputer as an external memory aid for a memory-impaired head injury patient during in-patient rehabilitation

Memory deficit is one of the most frequent cognitive complications encountered after brain injury. It is recognized as difficult to treat. Over the past decades, various strategies of memory remediation have been used. Among them, prosthetic devices, such as notebooks and alarms, have shown some benefit. This study describes the case of a 22-year-old man who demonstrated deficits in memory and executive function. In an in-patient rehabilitation setting, a microcomputer was introduced as an external memory aid. With this intervention, the patient demonstrated an immediate improvement in the ability to attend every therapy and ask for every medication on his schedule. This case study demonstrates the usefulness of a microcomputer as an external memory aid for a memory-impaired head injury survivor.

Multiple-trait quantitative trait loci analysis using a large mouse sibship

Quantitative trait loci influencing several phenotypes were assessed using a genetically heterogeneous mouse population. The 145 individuals were produced by a cross between (BALB/cJ x C57BL/6J)F1 females and (C3H/HeJ x DBA/2J)F1 males. The population is genetically equivalent to full siblings derived from heterozygous parents, with known linkage phase. Each individual in the population represents a unique combination of alleles from the inbred grandparents. Quantitative phenotypes for eight T cell measures were obtained at 8 and 18 mo of age. Single-marker locus, repeated measures analysis of variance identified nine marker-phenotype associations with an experimentwise significance level of P < 0.05. Six of the eight quantitative phenotypes could be associated with at least one locus having experiment-wide significance. Composite interval, repeated measures analysis of variance identified 13 chromosomal regions with comparisonwise (nominal) significance associations of P < 0.001. The heterozygous-parent cross provides a reproducible, general method for identification of loci associated with quantitative trait phenotypes or repeated phenotypic measures.

Effects of dopaminergic combination therapy for frontal lobe dysfunction in traumatic brain injury rehabilitation

Traumatic brain injury poses significant and diverse challenges to rehabilitation efforts. Neurobehavioural deficits represent a particularly difficult barrier to rehabilitative progress and societal reintegration. Early studies have identified dopaminergic drugs such as amantadine, bromocriptine and sinemet as potentially assistive in countering these deficits. To date, side effect profiles have been relatively benign, noted most frequently in small-scale case trials. The case of a 40-year-old patient with bilateral frontal traumatic brain injuries, and previous arteriovenous malformation (AVM) bleed with significant ataxia, dysarthria and neurobehavioural deficits is presented. This long range study demonstrates, through multiple varied dosing schedules, a trade off between the benefits and side effects of dopaminergic therapy, with implications for a larger brain injury population.

An integrated nanoliter DNA analysis device

A device was developed that uses microfabricated fluidic channels, heaters, temperature sensors, and fluorescence detectors to analyze nanoliter-size DNA samples. The device is capable of measuring aqueous reagent and DNA-containing solutions, mixing the solutions together, amplifying or digesting the DNA to form discrete products, and separating and detecting those products. No external lenses, heaters, or mechanical pumps are necessary for complete sample processing and analysis. Because all of the components are made using conventional photolithographic production techniques, they operate as a single closed system. The components have the potential for assembly into complex, low-power, integrated analysis systems at low unit cost. The availability of portable, reliable instruments may facilitate the use of DNA analysis in applications such as rapid medical diagnostics and point-of-use agricultural testing.

Effects of hydrotherapy on pressure ulcer healing

Pressure ulcers are a prevalent and potentially serious medical problem encountered in both the medical and rehabilitation settings. Because the progress of rehabilitation is often interrupted by the presence of pressure ulcers, the efficient care of these wounds is of great interest to the rehabilitation team. Patients in two acute care facilities with Stage III or IV pressure ulcers were identified and consented to participate in the study contained herein. All wounds were mechanically debrided of necrotic tissue, and then the patients were randomly assigned to the conservative treatment group (A; n = 18) or the conservative treatment plus whirlpool group (B; n = 24). Conservative treatment included measures to maximize pressure relief and wound care with wet-to-wet dressings using normal saline. The dressings were changed twice daily and when they became soiled. Whirlpool was administered for 20 min per day in Group B patients. Only those patients whose ulcers were followed-up for 2 or more wk were included in the study. Ulcers were then measured by a physician who was blinded as to the treatment groups. Ulcer dimension changes over time were compared between groups. The results indicate that the conservative treatment plus whirlpool group improved at a significantly faster rate than did the conservative treatment only group (P < 0.05).

Electrophoretic separations using sweeping fields

Sweeping-field electrophoresis is investigated as a method for increasing the resolution of low-voltage slab gel separations. In this technique a low direct current (DC) voltage is time multiplexed to an array of periodically spaced electrodes placed along the length of the slab in a manner that follows the band migration. Because the electrode spacing is smaller than the slab length, a larger field is generated, yielding an improved separation. The effect of the nonuniform electric field on band distortion is studied in some detail. Experimental band distortion results showed good agreement with theoretical predictions in a macroscopic sweeping-field electrophoresis system. Both analytical and numerical results show that band distortion can be effectively minimized when an appropriate sweep rate is selected for a narrow band range. Using this scheme we have achieved the same number of theoretical plates as a DC-driven system with one third of the drive voltage.

Coordinate control and variation in X-linked gene expression among female mice

In normal female mammals, one of the two X Chromosome (Chr) homologs per cell is silenced coordinately during early embryogenesis. The genes located on the inactivated X homolog are predicted to be influenced by the same underlying repression mechanism. To test the uniformity of cis-acting gene repression, 32 genetically identical F1 female mice were analyzed for differential expression of homologous alleles at three X-linked genes-Otc, Atp7a (= Mottled), and Hprt. Gene expression was assayed by the single-nucleotide primer extension (SNuPE) method, thereby allowing the three genes to be quantitated from the same RNA sample. Although variable between individual animals, the relative expression of the two alleles (allelic expression ratio) of the genes is significantly correlated within each steady-state RNA pool. When examined by animal age (3 months to 12 months), no statistically significant differences were observed in the mean or variance of allelic expression ratio. Together, the results confirm that X inactivation is coordinately controlled and is stable across the early- to mid-adult life span.

Two vectors for the insertion of mammalian selectable genes into yeast artificial chromosome cloned DNA

The introduction of cloned DNA into mammalian cells allows functional testing of genes contained on the fragments. In many cases, the exogenous DNA introduced into mammalian cells requires selectable genes that mark the presence of input DNA. Two new vectors, carrying mammalian selectable markers encoding for either neomycin-resistance (neo) or histidinol-resistance (hol), have been constructed for targeted integration to specific single-copy sites within yeast artificial chromosome (YAC) insert DNA. The integration cassettes comprise a single selectable yeast gene adjacent to a mammalian selectable gene, either LEU2 with neo or HIS3 with hol. Modification of the YAC occurs in yeast by transfection with linear DNA containing YAC-specific, unique, recombinogenic ends, thereby ensuring co-integration of the markers. Analysis of modified YACs confirms that both vectors correctly integrate into the targeted unique sites. The precise localization of selectable marker genes in the cloned DNA ensures the integrity of the genomic fragments during functional testing. Placement of mammalian selectable markers within the YAC insert DNA should allow for YAC-based gene targeting experiments in a variety of mammalian cell lines.

Transgenic mice for the establishment of histidinol-resistant embryonic fibroblast feeder layers

Gene targeting in mouse embryonic stem cells generates mutations by replacing an endogenous chromosomal region with a copy disrupted by a selectable genetic marker. The most commonly used selectable marker is the bacterial neo(r) gene, which confers resistance in mammalian cells to the antibiotic G418. Use of an alternative selectable marker, the Salmonella typhimurium gene hisD, should provide expanded applications for gene targeting. The hisD gene encodes the protein histidinol dehydrogenase, which catalyzes the conversion of histidinol to the amino acid histidine. Histidinol is toxic to mammalian cells, while histidine is an essential mammalian amino acid. Consequently, growth selection in cultures with media containing histidinol in place of histidine occurs by both histidine starvation and histidinol poisoning. The hisD selection is being tested for potential use in gene targeting experiments with mouse embryonic stem (ES) cells. Currently, most successful gene targeting experiments use primary embryonic fibroblast feeder layers, which assist in the maintenance of the pluripotential state of the embryonic stem cells. To support ES cell stability under histidinol selection, mice transgenic for the S. typhimurium hisD gene have been produced and used to generate embryonic fibroblast feeder cells. The transgenic embryonic fibroblasts survive under a wide range of histidinol-containing growth conditions and support growth of ES cell cultures.

The mouse X-linked developmental mutant, tattered, lies between DXMit55 and Xkh and is associated with hyperkeratinization

The X-linked mouse mutant phenotype, tattered (Td), is associated with prenatal lethality of males and has been mapped previously to the proximal region of the mouse X chromosome. We report here a refined position for Td and demonstrate that it lies in the approximately 0.9-cM interval between DXMit55 and Xkh. This enables us to predict that the human homologue lies either between CLCN5 and the evolutionary breakpoint that lies between GATA1 and PFC or distal to XK and proximal to the evolutionary breakpoint that lies between XK and DMD. Histological analysis of dorsal skin taken from 5-day-old heterozygous animals revealed that the mutation was associated with patches of hyperkeratinzation in the epidermis and in the hair follicles, accompanied by a mild inflammatory infiltrate in the underlying dermis.

Directed mutagenesis of YAC-cloned DNA using a rapid, PCR-based screening protocol

We have developed a system which facilitates the rapid modification of yeast artificial chromosome (YAC) insert DNA. Specific modifications, such as deletions, insertions and point mutations, can be generated by a two-step allele replacement method using the yeast translational suppressor, SUP4-o, as both a positive and negative selection. The introduction of the SUP4-o gene was successful in 4 out of 24 selected transformant colonies, while the subsequent homologous elimination occurred in 2 out of 30 colonies. The use of a simple, short-range PCR assay rapidly identified the correct events among the genetically selected isolates and should be generally applicable to YAC modifications.

Microfabricated structures for integrated DNA analysis

Photolithographic micromachining of silicon is a candidate technology for the construction of high-throughput DNA analysis devices. However, the development of complex silicon microfabricated systems has been hindered in part by the lack of a simple, versatile pumping method for integrating individual components. Here we describe a surface-tension-based pump able to move discrete nanoliter drops through enclosed channels using only local heating. This thermocapillary pump can accurately mix, measure, and divide drops by simple electronic control. In addition, we have constructed thermal-cycling chambers, gel electrophoresis channels, and radiolabeled DNA detectors that are compatible with the fabrication of thermocapillary pump channels. Since all of the components are made by conventional photolithographic techniques, they can be assembled into more complex integrated systems. The combination of pump and components into self-contained miniaturized devices may provide significant improvements in DNA analysis speed, portability, and cost. The potential of microfabricated systems lies in the low unit cost of silicon-based construction and in the efficient sample handling afforded by component integration.

Single nucleotide primer extension: quantitative range, variability, and multiplex analysis

The quantitative measurement of transcription products from homologous alleles at a diploid locus has broad application for the study of mammalian gene expression. Single nucleotide primer extension (SNuPE) analysis is a simple and sensitive method for allelic transcript discrimination requiring only 1 bp difference between alleles. In this study the effective range, experimental variation, and the influences of poly(dT)-primed and gene-specific reverse transcriptions are characterized. The ability to analyze several genes from a single reverse transcription reaction is assessed as well. For the genes examined, the maximum range of detection is reached when the minor transcript represents 1/250 of the major allele. Relatively little error is seen within or between assays and linearity of response is maintained over an approximately thousandfold range.

Splinting for carpal tunnel syndrome: in search of the optimal angle

Carpal tunnel syndrome (CTS) is the most common of the compression neuropathies. Several studies have demonstrated the efficacy of wrist splinting in relieving the symptoms of CTS; however, the chosen angle of immobilization has varied. Wick catheter measurements of carpal tunnel pressures suggest that the neural position has less pressure and, therefore, greater potential to provide relief from symptoms. This study is a prospectively gathered, blind trial comparing the symptom relief experienced by wearers of splints immobilized at 20 degrees extension and at neutral. The results indicate that the neutral angle provided superior symptom relief, and that the relief did not often improve between 2 weeks and 2 months of wear. Relief of symptoms was not related to the length of time that the patient had experienced of CTS symptoms. The results also indicate that the results of the electromyography/nerve conduction study (EMG/NCS) do not provide information about the subjects' likely response to splinting.

Genomic analysis using a yeast artificial chromosome library with mouse DNA inserts

A yeast artificial chromosome library with mouse genomic DNA inserts has been constructed. The library encompasses a 2.5-fold coverage of the mouse genome, with an average insert size of 250 kilobases. The screening strategy uses the polymerase chain reaction on pooled DNAs prepared from individually stored clones. The usefulness of the library for chromosome walking was illustrated by constructing a 600-kilobase-long contig of DNA surrounding Hba-ps4, a DNA marker that is tightly linked to the fused (Fu) locus on chromosome 17.

The role of yeast artificial chromosome clones in generating genome maps

The cloning of large DNAs as yeast artificial chromosomes (YACs) holds the promise of greatly expanding the scope of physical genomic mapping. Recent improvements in YAC clone libraries and their screening, as well as in the analysis of YAC-cloned DNA, are beginning to fulfill the potential of this system.

Mapping the Drosophila genome with yeast artificial chromosomes

The ability to clone large fragments of DNA in yeast artificial chromosomes (YAC's) has created the possibility of obtaining global physical maps of complex genomes. For this application to be feasible, most sequences in complex genomes must be able to be cloned in YAC's, and most clones must be genetically stable and colinear with the genomic sequences from which they originated (that is, not liable to undergo rearrangement). These requirements have been met with a YAC library containing DNA fragments from Drosophila melanogaster ranging in size up to several hundred kilobase pairs. Preliminary characterization of the Drosophila YAC library was carried out by in situ hybridization of random clones and analysis of clones containing known sequences. The results suggest that most euchromatic sequences can be cloned. The library also contains clones in which the inserted DNA is derived from the centromeric heterochromatin. The locations of 58 clones collectively representing about 8 percent of the euchromatic genome are presented.

Cloning human telomeric DNA fragments into Saccharomyces cerevisiae using a yeast-artificial-chromosome vector

Telomeric fragments of human DNA ranging in size from 50 to 250 kilobases were cloned into Saccharomyces cerevisiae using a yeast-artificial-chromosome (YAC) vector. Six human-telomeric YAC (HTY) strains were selected by virtue of the specific hybridization of their DNA with the human telomeric terminal-repeat sequence (TTAGGG)n, and the telomeric localization of this sequence within each YAC was demonstrated by its sensitivity to nuclease BAL-31. In situ hybridization of DNA from three of these HTY strains with human metaphase chromosomes yielded discrete patterns of hybridization signals at the telomeres of a limited number of human chromosomes, different for each clone. DNA from selected cosmid subclones of one of the HTY strains was used to localize the origin of the cloned telomeric DNA by in situ hybridization to the tip of the long arm of chromosome 7.