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Biomedical subjects

B Riley

Publications and source records attributed to B Riley.

At least 19 recordsLinked to original sources
PubMed2000

Halo vest effect on balance.

OBJECTIVE: To determine the effect of a halo vest, a cervical orthosis, on clinically relevant balance parameters. DESIGN: Subjects performed unipedal stance (with eyes open and closed, on both firm and soft surfaces) and functional reach, with and without the application of a halo vest. SUBJECTS: A convenience sample of 12 healthy young subjects, with an equal number of men and women. OUTCOME MEASURES: Seconds for unipedal stance (maximum 45); inches for functional reach. RESULTS: Both unipedal stance times and functional reach (mean +/- standard deviation) were significantly decreased with the halo vest as compared to without it (29.1+/-5.8 vs. 32.8+/-6.4 seconds, p = .002; 12.9+/-1.4 vs. 15.1+/-2.1 inches, p<.01). CONCLUSION: A halo vest causes an acute impairment in balance in the healthy young. It is likely that the impairment would be greater in older or injured patients, thus increasing their risk for a fall, which could have devastating consequences.

Adult↗
PubMed2000

Effects of a short-term health promotion intervention for a predominantly African-American group of stroke survivors.

BACKGROUND: The study examined the effects of a 12-week health promotion intervention for a predominantly urban African-American population of stroke survivors. DESIGN: A pre-test/post-test lag control group design was employed. PARTICIPANTS/SETTING: Participants were 35 stroke survivors (9 male, 26 female) recruited from local area hospitals and clinics. MAIN OUTCOME MEASURES: Biomedical, fitness, nutritional, and psychosocial measures were employed to assess program outcomes. RESULTS: Treatment group made significant gains over lag controls in the following areas: (1) reduced total cholesterol, (2) reduced weight, (3) increased cardiovascular fitness, (4) increased strength, (5) increased flexibility, (6) increased life satisfaction and ability to manage self-care needs, and (7) decreased social isolation. CONCLUSION: A short-term health promotion intervention for predominantly African-American stroke survivors was effective in improving several physiological and psychological health outcomes.

Black or African American↗
PubMed1999

Structure-activity relationships for a class of inhibitors of purine nucleoside phosphorylase.

Values of inhibition constants, Ki, for a family of structurally related, competitive inhibitors of calf spleen purine nucleoside phosphorylase (PNP) have been determined employing both inosine as substrate and a manual assay and 2-amino-6-mercapto-7-methylpurine ribonucleoside (MESG) as substrate and a robot-based enzyme kinetics facility. Several of the values determined robotically were confirmed employing the same substrate and a manual assay. Surprisingly, for many of the inhibitors examined, values of Ki determined with MESG as substrate are smaller than those obtained employing inosine as substrate by a factor that varies from less than 2 to 10. Values of concentrations required for 50% inhibition of PNP, IC50, have also been determined for the same family of inhibitors employing inosine as substrate. Values of IC50ino and those for Kiino and Kimesg for subsets of the inhibitors have been employed as training sets to create quantitative structure-activity relationships (QSAR) which have substantial power to predict values of IC50 and Ki for inhibitors outside the training set. These QSAR models should be useful in guiding future medicinal chemistry efforts designed to discover inhibitors of PNP having increased potency.

Animals↗
PubMed1999

An electrophysiological exploration of the double crush hypothesis.

The double crush hypothesis has not been rigorously evaluated in humans. We therefore analyzed cases of C6, C7, and C8 radiculopathy and exploited the fact that the median sensory response is of C6/C7 origin and the median motor response is primarily of C8 origin. We hypothesized that C6 and/or C7 cases would demonstrate an increased frequency of median mononeuropathy by sensory criteria, and C8 cases would demonstrate an increased frequency of median mononeuropathy by motor criteria. We also hypothesized that median sensory and motor response parameters among these same groups would be altered in ways consistent with a proximal influence on distal nerve conduction studies. Although median mononeuropathy was unexpectedly common (22.1%) among cases of cervical radiculopathy (which may explain the clinical acceptance of the double crush hypothesis), none of the hypotheses was supported. This study identified no evidence to support a neurophysiological explanation for the double crush hypothesis.

Age Factors↗
PubMed1999

Strategies for ventilatory support.

Since the introduction of manual positive pressure ventilation during the Copenhagen polio epidemic of 1952, a range of mechanical devices and methods of ventilatory support have been developed to provide life-saving respiratory therapy to critically ill patients. In addition to the development of the equipment hardware to enable effective mechanical ventilation, there has been a gradual realisation that a single mode of ventilation is not universally applicable to all patients, individual pathologies, or to individual patients at various stages in the evolution of their pulmonary pathology. While mechanical ventilation can undoubtedly be life-saving, it can also cause lung damage as a result of its non-physiological method of promoting effective gas exchange. This iatrogenic problem is known as ventilator induced lung injury and, although it may be a problem in any patient requiring mechanical ventilation for any reason, is of particular importance to those patients requiring mechanical ventilation as a consequence of trauma. This chapter describes the range of ventilatory support techniques available, the problem of ventilator induced lung injury with specific reference to trauma patients and offers a strategy for ventilatory support in the trauma patient.

Humans↗
PubMed1996

No evidence for linkage of chromosome 22 markers to schizophrenia in southern African Bantu-speaking families.

Previous studies have demonstrated possible linkage between chromosome 22 and one of the hypothesized schizophrenia susceptibility genes. Interpretation of these data, however, is not straightforward: although not significant at the level traditionally accepted to demonstrate linkage, reported lod scores were greater than should have occurred by chance for an unlinked marker based on simulation studies. Further, these studies used sample populations which were either of mixed nationality and ethnicity, or mixed ethnic ancestry from one country. We therefore tested for linkage between highly polymorphic chromosome 22 markers and schizophrenia in a sample of southern African Bantu-speaking black families, a population known to have diverged within the last 2,000 years. We also tested one candidate locus, the gene for the soluble form of catechol-O-methyl transferase (COMT) located at 22q11, which has been suggested as the cause of psychiatric symptoms observed in velo-cardio-facial syndrome (VCFS, including DiGeorge syndrome), and which is known to be functionally as well as genetically polymorphic. There is no evidence to support the linkage of markers on chromosome 22 to susceptibility to schizophrenia in this population, using either parametric or nonparametric analysis.

Catechol O-Methyltransferase↗
PubMed1996

An unusual case of Ecstasy poisoning.

We describe a case of poisoning with 3,4-methylenedioxymet-amphetamine Ecstasy that presented with all the features suggestive of a fatal outcome, including a creatinine phosphokinase level markedly higher than any previously reported. The patient, a paraplegic, was treated with dantrolene and made a full recovery.

Adult↗
PubMed1996

No evidence for allelic association between schizophrenia and a polymorphism determining high or low catechol O-methyltransferase activity.

OBJECTIVE: Catechol O-methyltransferase (COMT) inactivates catecholamines by methylating their m-hydroxy group. Some previous studies using biochemical methods have found higher levels of COMT activity in schizophrenic patients. Recently, the genetic polymorphism that underlies variation in COMT activity, which results in the creation of a NlaIII restriction site in the low-activity allele, has been elucidated. METHOD: This study investigated this polymorphism in 78 unrelated schizophrenic patients and 78 comparison subjects matched for age and ethnicity. High-molecular-weight DNA was isolated from lymphocytes with routine procedures, and each individual was typed for high and low COMT activity. RESULTS: The frequency of the NlaIII polymorphism was 0.51 in the schizophrenic patients and 0.53 in the comparison subjects, and no significant allelic or genotypic associations were observed. CONCLUSIONS: There was no evidence for variation in COMT activity between a group of schizophrenic patients and matched comparison subjects.

Alleles↗
PubMed1996

Battlefield trauma life support: its use in the resuscitation department of 32 Field Hospital during the Gulf War.

32 Field Hospital was one of two forward British field hospitals deployed during the 1990-1991 Gulf War in northern Saudi Arabia. We describe the use of Battlefield Trauma Life Support (BATLS), a military derivation of Advanced Trauma Life Support (ATLS) as used in the hospital's resuscitation department and discuss the application of ATLS principles in the military environment. Teaching BATLS to doctors, nurses, and combat medical technicians provided a common system for all department members to work toward. This proved to be an efficient system for horizontal casualty management by a trauma team of three people.

Hospitals, Military↗
PubMed1994

Role of FGFs in skeletal muscle and limb development.

Fibroblast growth factors (FGFs) are a family of nine proteins that bind to three distinct types of cell surface molecules: (i) FGF receptor tyrosine kinases (FGFR-1 through FGFR-4); (ii) a cysteine-rich FGF receptor (CFR); and (iii) heparan sulfate proteoglycans (HSPGs). Signaling by FGFs requires participation of at least two of these receptors: the FGFRs and HSPGs form a signaling complex. The length and sulfation pattern of the heparan sulfate chain determines both the activity of the signaling complex and, in part, the ligand specificity for FGFR-1. Thus, the heparan sulfate proteoglycans are likely to play an essential role in signaling. We have recently identified a role for FGF in limb bud development in vivo. In the chick limb bud, ectopic expression of the 18 kDa form of FGF-2 or FGF-2 fused to an artificial signal peptide at its amino terminus causes skeletal duplications. These data, and the observations that FGF-2 is localized to the subjacent mesoderm and the apical ectodermal ridge in the early developing limb, suggest that FGF-2 plays an important role in limb outgrowth. We propose that FGF-2 is an apical ectodermal ridge-derived factor that participates in limb outgrowth and patterning.

Animals↗
PubMed1993

Chromosomal assignment of the second locus for autosomal dominant cerebellar ataxia (SCA2) to chromosome 12q23-24.1.

The autosomal dominant cerebellar ataxias (ADCA) are a group of neurodegenerative disorders characterized by onset with gait ataxia, dysarthria, dysmetria and dysdiadochokinesia. We have demonstrated previously genetic heterogeneity within these disorders by excluding the disease locus from the documented spinocerebellar ataxia locus (SCA1) on chromosome 6p in a large Cuban founder population. We now report the assignment of a second locus for ADCA (SCA2) to chromosome 12q23-24.1 following linkage analyses carried out for the Cuban pedigrees, with probable flanking markers D12S58 and phospholipase A2. Investigation of linkage to the interval containing SCA2 for seven French ADCA families, previously excluded from linkage to SCA1, provides preliminary data suggesting the existence of a third ADCA locus (SCA3).

Chromosome Mapping↗
PubMed1993

Extra inspiratory work of breathing imposed by cricothyrotomy devices.

Using a lung model for spontaneous ventilation, we have assessed the additional work of inspiration imposed by a variety of cannulae ranging from the 12- and 14-gauge intravascular cannulae to the 8.0-mm i.d. adult tracheostomy tube. Work (W) ranged between 9 and 2262 mJ litre-1 and power (W) between 0.2 and 37.7 mW litre-1 min; the smallest values were obtained with the 8.0-mm i.d. adult tracheostomy tube and the 12- and 14-gauge intravascular cannulae gave the largest values. With any given cannula, W and W were influenced by ventilation (tidal volume and frequency) and ventilatory wave pattern of the analogue lung. The results obtained from the 12- and 14-gauge cannulae represent what is probably an excessive inspiratory workload, whereas the other four devices (Portex MiniTrach, 4.0, 6.0 and 8.0 tracheostomy tubes) may be suitable in the short term for relieving airway obstruction and compatible with spontaneous ventilation.

Cricoid Cartilage↗