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Biomedical subjects

K Jones

Publications and source records attributed to K Jones.

At least 253 records · Page 14Linked to original sources
PubMed1994

A preliminary cost effectiveness analysis of an intervention to reduce homelessness among the mentally ill.

The Critical Time Intervention Project is a three-year clinical trial which tests a time-limited, supportive intervention to reduce recurrent homelessness among mentally ill men moving from a shelter to the community. Along with a comparison of nights spent homeless and other outcomes, the evaluation of the Critical Time Intervention includes a comparison of the relative costs of the intervention, compared to usual treatment. Such cost effectiveness analyses are difficult to perform and are rarely applied to mental health treatments. This paper presents the general scheme of this analysis and discusses critical issues in the construction and measurement of cost variables. Preliminary results which have implications for the cost analysis are presented.

Activities of Daily Living↗
PubMed1994

The role of intracellular free calcium in motor neuron disease.

The intracellular calcium (Ca2+) concentrations of motoneurons can be altered by the influx of Ca2+ into the cell by the opening of voltage-dependent Ca2+ channels and ligand-gated channels linked to Ca2+ influx, especially by the N-methyl-D-aspartate (NMDA) type of excitatory amino acid receptor. Intracellular Ca2+ concentration is also affected by the release of Ca2+ buffered in mitochondria and endoplasmic reticulum. Evidence that motoneurons may be selectively vulnerable to Ca(2+)-induced cell death include the following observations: (i) the presence of excitatory amino acid receptors on the cell membranes of motoneurons, some of which would permit Ca2+ influx (e.g. NMDA receptors); (ii) the availability of the presynaptic terminal for antibody-mediated effects leading to changes in cell permeability and Ca2+ influx; and (iii) the limited amounts of intracellular Ca(2+)-binding proteins such as calbindin D28K and parvalbumin in motoneurons. Elevation of intracellular free Ca2+ may also be a common event in a number of independent mechanisms leading to motoneuron death in motor neuron disease.

Animals↗
PubMed1994

Effect of frequency-altered feedback on stuttering frequency at normal and fast speech rates.

The purpose of this study was to determine the effect of the magnitude and direction of the frequency shift of frequency-altered auditory feedback (FAF) on stuttering frequency at both normal and fast speech rates. Twelve adult male and 2 adult female subjects who stutter read 10 different passages at either a normal or fast speech rate under nonaltered auditory feedback (NAF) and each of four FAF conditions in which the feedback signal was shifted: up one-half octave; up one octave; down one-half octave; and down one octave. Mean stuttering frequency for NAF was significantly higher than mean stuttering frequencies for all FAF conditions (p < 0.05). There were no statistically significant differences between the FAF conditions (p > 0.05). Subjects exhibited significantly more disfluencies under the fast speech rate condition relative to the normal speech rate condition. Future research should examine the relationship between frequency shifts of less than one-half octave and stuttering amelioration.

Adolescent↗
PubMed1994

A novel gene encoding a B-box protein within the BRCA1 region at 17q21.1.

A novel cDNA clone was isolated using a polyclonal serum directed against partially purified ovarian carcinoma antigen CA125. The deduced peptide sequence lacked membrane protein characteristics expected for CA125 but encompassed a B-box/coiled coil motif present in many genes with transformation potential. The gene was mapped by fluorescence in situ hybridization within the minimum region known to contain the familial breast/ovarian carcinoma gene, BRCA1. YAC and cosmid clones were isolated and used to refine the location of this gene adjacent and proximal to the RNU2 locus. The exon structure of the gene was determined. Extensive SSCP and sequence analysis of over 100 tumour and normal DNAs from familial and sporadic breast cancers and sporadic ovarian cancers failed to detect mutations in the coding region of this gene.

Amino Acid Sequence↗
PubMed1994

EMEA (European Medicines Evaluation Agency) and the new pharmaceutical procedures for Europe.

Regulation of medicines in the United Kingdom has changed considerably since the establishment of the Medicines Control Agency in 1989, and other changes will take place throughout the European Community (EC) over the next few years. 1995 will see the introduction of a centralised procedure, applicable to a small number of innovative drugs, and a decentralised procedure, based on mutual recognition of licences granted by existing control authorities in other EC countries.

Drug Approval↗
PubMed1994

Induction of trimethyltin neurotoxicity by dietary administration.

Groups of 12 male and 12 female rats were fed diets containing 0 or 8ppm trimethyltin chloride for up to 25 days. All the animals were observed prior to the study start and daily throughout the study for any changes in clinical condition. In addition, detailed clinical observations, including quantitative assessments of landing foot splay, sensory perception, muscle weakness and locomotor activity were monitored during the study. At the end of the study, the rats were killed and subjected to a full Post-mortem. Selected nervous system tissues were removed, processed and examined microscopically. Clinical signs typical of trimethyltin neurotoxicity (e.g. aggression, shaking and convulsions) were seen in rats receiving diets containing 8ppm trimethyltin chloride for as little as 22 days. Neuropathological lesions consisting of extensive neuronal cell necrosis in the limbic region of the brain, vacuolar degeneration of ventral horn cells of the spinal cord and a marginal increase in Wallerian-type degeneration were seen. The study demonstrates that trimethyltin neurotoxicity can be induced by dietary administration and that both male and female rats are equally sensitive.

Animals↗
PubMed1994

A molecular technique for identification of bacteria using small subunit ribosomal RNA sequences.

We have recently developed a novel molecular technique for identification of specific bacterial species within a complex mixture. The technique uses PCR to amplify small subunit ribosomal RNA (SSU rRNA) genes from a mixture of bacteria. One of the PCR primers is labeled with a fluorescent dye to allow detection of the amplified product. The PCR product is then digested with restriction enzymes and a capillary electrophoresis unit equipped with a laser-induced fluorescence detector is employed to analyze the restriction fragments. Only restriction fragments that contain the fluorescent-labeled primer are detected. Generally, the nucleotide sequence of the SSU rRNA genes is unique for each bacterial species. Consequently, the fluorescent-labeled restriction fragments from different bacterial species often have characteristic lengths. Thus, the different fluorescent peaks that appear in a capillary electropherogram correspond to labeled restriction fragments from different bacterial species. This protocol allows us to identify a number of different bacterial species in a complex mixture. Only a minute sample of bacterial DNA and a minimal amount of time (8-10 h) are required for this analysis. The protocol is sensitive, rapid and capable of identifying a broad spectrum of bacterial species.

Bacteria↗
PubMed1994

Tailoring velopharyngeal surgery: the influence of etiology and type of operation.

The results of 132 consecutive endoscopically selected pharyngoplasties were assessed. Depending on the size and shape of the velopharyngeal defect on attempted closure, patients had been allocated to one of four pharyngoplasties: (1) a superiorly based pharyngeal flap combined with a V-Y pushback of the soft palate (Honig), (2) a modified Hynes approach, (3) a superiorly based pharyngeal flap, or (4) a fish flap. Patients were categorized according to etiology as having cleft palate, submucous cleft palate, disproportion, or neurologic origin. Acceptable nasal resonance was found after 81 percent of the Honig operations, 81 percent of the Hynes operations, and 63 percent of the superiorly based flap operations, vindicating the selection criteria based on palatal and pharyngeal wall movement. The fish flap operation was successful in only 50 percent and is not recommended. The cleft, submucous cleft, disproportion, and neurologic categories were equally well corrected by the Honig and Hynes operations. Side effects were common, with catarrh or snoring in 51 percent, difficulty breathing through the nose in 27 percent, and 9 percent requiring revision of their pharyngoplasty (6 of 53 Honig and 5 of 63 Hynes operations). The higher median age for those patients requiring pharyngoplasty revision (17 versus 10 years) suggests more cautious use in the older patient.

Cleft Palate↗
PubMed1993

Gelsolin immunoreactivity in corneal amyloid, wound healing, and macular and granular dystrophies.

Immunohistologic studies of tissue sections obtained from patients with type 1 or type 2 lattice corneal dystrophy, polymorphic amyloid degeneration, or gelatinous amyloid degeneration were performed by using a monoclonal antibody raised to a chymotryptic fragment inclusive of the carboxy-terminal half of plasma gelsolin, and also with a series of polyclonal antibodies specific for synthetic peptides corresponding to immunogenic epitopes of gelsolin. These epitopes are parts of sequences at the amino- and carboxy-terminal ends of gelsolin, as well as adjacent to and inclusive of the codon 187 mutant 7-11 kD fragment that has been shown to be the subunit protein of amyloid fibrils occurring systemically in patients affected by Finnish type familial amyloidosis. These antibodies were also tested on tissue sections obtained from patients with granular and macular corneal dystrophy, corneal wounds, and normal control corneas. Specificity of staining was established by absorption with gelsolin purified from plasma, or the appropriate synthetic peptide. Gelsolin immunoreactivity was detected in the conjunctival and skin amyloid in familial amyloidosis by using familial amyloid (Finnish type) antibody. In other types of corneal amyloid, including lattice dystrophy type 1, immunoreactivity with gelsolin and synthetic peptides was observed adjacent to the deposits, but rarely within them. In macular dystrophy, variable staining of the deposits could result from the association of subunit proteins with glycosaminoglycans.

Amyloidosis↗
PubMed1993

Inactivation of peptidoleukotrienes in the isolated perfused rat lung.

Inactivation of peptidoleukotrienes by alveolar transfer and metabolism was investigated in isolated perfused rat lungs. [3H]Leukotriene (LT)C4 or [3H]LTE4 was instilled into the airways and 25 min later the distribution of tritiated metabolites in bronchoalveolar lavage fluid, lung, and perfusate was determined. Metabolism of LTC4 was found to occur in both the alveolar and vascular space in contrast to metabolism of LTE4, which occurred exclusively on the alveolar side. The alveolar transfer of leukotrienes into the perfusate was slow with only 25-29% transfer occurring during the 25-min perfusion. Only a small percentage of instilled LTC4 was transferred out of the airways unmetabolized, suggesting that this leukotriene is not the major one that is removed from the airways. In contrast, LTE4 either added directly into the airways or produced in the alveolar space from LTC4 metabolism was more readily transferred out of the lung. LTE4 was transported into alveolar cells by a nonenergy requiring, receptor-mediated mechanism inhibited by LTD4/LTE4 receptor antagonists and by probenecid. Cysteine-containing compounds (cysteine, cystine, and N-acetylcysteine) added to the perfusate caused a significant increase in LTE4/N-acetyl-LTE4 transport possibly due to a coupling of cyst(e)ine (in) and LTE4 (out) transport. Metabolism of LTC4 by gamma-glutamyltransferase appears to be the rate limiting step of peptidoleukotriene inactivation in the rat airways, being necessary for both metabolic inactivation and the formation of products which can be eliminated by transfer.

Animals↗
PubMed1993

Brain electrical correlates of psychological measures: strategies and problems.

We explore relationships between brain electrical activity and cognitive performance where qEEG data are correlated with psychological variables gathered at a different time. For a population of 202 healthy adults using univariate and multivariate correlation techniques in a split half replication design, we confirm prior findings that subjects with better psychological scores show shorter evoked potential (EP) latency, suggesting that speed of processing is an important factor in cognitive performance. By canonical correlation we demonstrate a consistent, replicable relationship between electrophysiological and behavioral data. We suggest that reliance upon univariate correlation may have fueled early controversies about relationships between electrophysiology and IQ. In addition we correlate psychological factors with the entire qEEG data set (both EP and spectral analyzed EEG) and demonstrate the use a multidimensional image graphics techniques to assist in visual assessment of the resulting correlation matrices.

Adult↗
PubMed1993

The effect of posture on gastric emptying and intragastric distribution of oil and aqueous meal components and appetite.

BACKGROUND: It is uncertain whether gastric emptying of fat is determined mainly by its physical characteristics or chemical composition. In particular, the intragastric distribution of extracellular fat and the importance of that distribution to gastric emptying of fat is controversial. The effects of posture on gastric emptying, intragastric distribution, and appetite after ingestion of a meal containing oil and aqueous phases was evaluated. METHODS: Eleven volunteers consumed 60 mL 99mTc-(V)-thiocyanate-labeled olive oil and 290 mL 113mIn-labeled soup while sitting and while lying in the left lateral decubitus position. Hunger before and after the meal was recorded. RESULTS: In the sitting position, oil emptied from the stomach more slowly (P < 0.01) whereas in the decubitus position oil emptied faster (P < 0.01) than the aqueous phase. Oil was preferentially retained in the proximal stomach when sitting (P < 0.01), and more oil was retained in the distal stomach in the decubitus position (P < 0.05). The amount of oil that emptied in the first 180 minutes was not different between the two postures. The aqueous phase emptied much more slowly (P < 0.01) in the decubitus position. At 120 minutes and 180 minutes, subjects were less hungry (P < 0.05) in the decubitus position. In the decubitus position, hunger at 120 minutes and 180 minutes was related to the retention of oil (r > or = 0.79; P < 0.01) in the stomach. CONCLUSIONS: These results indicate that (1) gravity has a major effect on the intragastric distribution and relatively little effect on total stomach emptying of oil, and (2) postprandial hunger is affected by posture and, in the decubitus position, is inversely related to the amount of oil that has entered the small intestine.

Adolescent↗
PubMed1993

Do places matter? A multi-level analysis of regional variations in health-related behaviour in Britain.

A number of commentators have argued that there is a distinctive geography of health-related behaviour. Behaviour has to be understood not only in terms of individual characteristics, but also in relation to local cultures. Places matter, and the context in which behaviour takes place is crucial for understanding and policy. Previous empirical research has been unable to operationalize these ideas and take simultaneous account of both individual compositional and aggregate contextual factors. The present paper addresses this shortcoming through a multi-level analysis of smoking and drinking behaviours recorded in a large-scale national survey. It suggests that place, expressed as regional differences, may be less important than previously implied.

Adolescent↗