Biomedical subjects
Publications and source records attributed to J S Watson.
Current and proposed European Union (EU) regulations require the residual material from municipal solid waste incineration to be characterised prior to disposal. X-Ray fluorescence (XRF) provides a rapid and non-destructive technique for analysing such materials.
Practitioner-led hand clinics were introduced in our unit in the year 2000 as a response to the high and increasing number of postoperative hand trauma patients coming to consultant clinics. The aim of this study was to evaluate the influence of these clinics on rupture rates following primary tendon repair in the hand. The study specifically examined:zone II flexor tendon repairsflexor pollicis longus (FPL) tendon repairsextensor pollicis longus (EPL) tendon repairs. Prospective data collection were undertaken for these particular operations over a 17-month study period. Prior to the introduction of the practitioner-led hand clinics previous audits had demonstrated rupture rates of 30% zone II flexor tendon repairs, 16% for FPL repairs and 5% for EPL repairs. Rupture rates after the introduction of practitioner-led hand clinics fell in all of the study categories-to 17% for zone II flexor tendon repairs, 4% for FPL repairs and 0% for EPL repairs. It is suggested that improved continuity of care by experienced hand therapists may have contributed to the observed improvements in outcome.
Dupuytren's disease (DD) is a benign fibroproliferative disease of unknown cause. It is a familial condition that commonly affects Caucasians. Genetic studies have yet to identify the genes involved in DD. Transforming growth factor beta (TGFbeta) family members are multifunctional; some play a central role in wound healing and fibrosis. Previous studies have implicated TGFbeta cytokines and receptors in DD. In the light of this evidence, TGFbeta receptors represent candidate susceptibility genes for this condition. In this study, we investigated the association of single nucleotide polymorphisms (SNPs) in TGFbeta receptors one, two and three (TGFbetaRI, RII and RIII) with the risk of DD formation. A polymerase chain reaction-restriction fragment length polymorphism method was used for genotyping novel and known TGFbeta receptor polymorphisms. DNA samples from 183 DD patients and 181 controls were examined. There was a statistically significant difference (p<0.05) in genotype frequency distributions between cases and controls for TGFbetaRI polymorphisms in the recessive model. However, there were no significant difference in genotype or allele frequency distributions between cases and controls for the TGFbetaRII and TGFbetaRIII SNPs.
A prospective double-blind, randomized, controlled clinical trial was conducted to assess the use of ADCON-T/N after flexor tendon repair in Zone II. Forty-five patients with 82 flexor tendon repairs in 50 digits completed the study. ADCON-T/N was injected into the tendon sheath after tenorrhaphy in the experimental group while the control group was not treated with ADCON-T/N. ADCON-T/N had no statistically significant effect on total active motion at 3, 6 and 12 months but the time taken to achieve the final range of motion was significantly shorter in treated patients. ADCON-treated patients had a higher rupture rate but this was not significant.
The use of dynamic traction splintage is established in the treatment of complex intra-articular phalangeal fractures. Several different systems have been used and we report our experience with one of these, the Pins and Rubber Traction System. A cohort of 14 patients with complex intra-articular fractures at the base of the middle phalanges of the fingers were treated and assessed prospectively over a 2.5-year period (mean, 20 months; range, 7-28 months). The mean active range of motion regained, at the proximal interphalangeal joint, was 74 degrees (range, 0-100 degrees ). The mean total active motion of the injured digit was 196 degrees (range, 40-275 degrees ). Refinements in the regime are suggested as a result of this investigation.
Transforming growth factor beta (TGFbeta) family members are multifunctional cytokines that play a key role in cellular growth, proliferation and differentiation. Transmembrane signalling by TGFbeta occurs via a complex of the serine/threonine kinases TGFbeta type 1 (TGFbetaRI), type 2 (TGFbetaRII), and type 3 (TGFbetaRIII) receptors. Previous studies have implicated TGFbeta receptors (TGFbetaR) in a variety of important hereditary clinical disorders. Mutations of the TGFbetaR genes have been observed in several human cancers. The aim of this study was to identify and confirm novel single nucleotide polymorphisms (SNPs) in TGFbetaRI and RIII and to determine the relative allele and genotype frequencies of these SNPs. SNPs were identified from the examination of sequence alignments held in databases and were confirmed by DNA sequencing. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was devised for genotyping TGFbeta receptor polymorphisms. DNA samples from 91 controls were examined. The observed heterozygosities of TGFbetaRI and TGFbetaRIII gene polymorphisms in the control population were 43 and 33%, respectively, suggesting these SNPs could be useful markers in disease association studies.
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The genes involved in the pathogenesis of Dupuytren's disease have yet to be identified. In this study, we tested for an association between Dupuytren's disease (DD) and a novel insertion polymorphism within the 5'-untranslated region (5'-UTR), of the TGFbeta(2) gene. DNA samples from 179 DD patients and 187 ethnically matched controls were examined. There was no statistically significant difference in TGFbeta(2) allele frequency distributions between cases and controls for the TGFbeta(2) polymorphism.
A case involving the accidental loss of all the skin of the palm and the palmar surfaces of all four fingers, and its replacement as a full-thickness graft, is presented. The importance of long-term follow-up to detect and correct palmar skin contractures is emphasized. The literature which relates to this difficult area of loss is reviewed.
Dupuytren's disease is a benign fibroproliferative disease of unknown aetiology. It is often familial and commonly affects Northern European Caucasian men, but genetic studies have yet to identify the relevant genes. Transforming growth factor beta one (TGF-beta1) is a multifunctional cytokine which plays a central role in wound healing and fibrosis. It stimulates the proliferation of fibroblasts and the deposition of extracellular matrix. Previous studies have implicated TGF-beta1 in Dupuytren's disease, suggesting that it may represent a candidate susceptibility gene for this condition. We have investigated the association of four common single nucleotide polymorphisms in TGF-beta1 with the risk of developing Dupuytren's disease. A polymerase chain reaction-restriction fragment length polymorphism method was used for genotyping TGF-beta1 polymorphisms. DNA samples from 135 patients with Dupuytren's disease and 200 control subjects were examined. There was no statistically significant difference in TGF-beta1 genotype or allele frequency distributions between the patients and controls for the codons 10, 25, -509 and -800 polymorphisms. Our observations suggest that common TGF-beta1 polymorphisms are not associated with a risk of developing Dupuytren's disease. These data should be interpreted with caution since the lack of association was shown in only one series of patients with only known, common polymorphisms of TGF-beta1. To our knowledge, this is the first report of a case-control association study in Dupuytren's disease using single nucleotide polymorphisms in TGF-beta1.
A method is presented for the routine, rapid, and quantitative analysis of aliphatic and naphthenic acids in crude oils, based on their isolation using nonaqueous ion exchange solid-phase extraction cartridges. The isolated acid fractions are methylated and analyzed by gas chromatography and gas chromatography/mass spectrometry. The method is effective on both light and heavy oils and is capable of providing mechanistic information of geochemical significance on the origin of the acids in the oils. Analysis of oils that were solvent extracted from laboratory and field mesocosm marine sediment oil degradation studies indicate that this new method of analyzing the products of hydrocarbon biodegradation may be a useful tool for monitoring the progress of bioremediation of oil spills in the environment.
Prior research on the ability to solve the Piagetian invisible displacement task has focused on prerequisite representational capacity. This study examines the additional prerequisite of deduction. As in other tasks (e.g., conservation and transitivity), it is difficult to distinguish between behavior that reflects logical inference from behavior that reflects associative generalization. Using the role of negation in logic whereby negative feedback about one belief increases the certainty of another (e.g., a disjunctive syllogism), task-naive dogs (Canis familiaris; n=19) and 4- to 6-year-old children (Homo sapiens; n=24) were given a task wherein a desirable object was shown to have disappeared from a container after it had passed behind 3 separate screens. As predicted, children (as per logic of negated disjunction) tended to increase their speed of checking the 3rd screen after failing to find the object behind the first 2 screens, whereas dogs (as per associative extinction) tended to significantly decrease their speed of checking the 3rd screen after failing to find the object behind the first 2 screens.
Partial preservation of object-oriented hand use (OOHU) was studied behaviorally in a 6-1/2-year-old girl with the preserved speech variant (PSV) of Rett syndrome (RS), associated with a T 158 missense MeCP2 mutation and favorably skewed X-inactivation. At home, OOHU was limited except for self-feeding. When examined, overall time invested in toy play was only 38% of that of healthy subjects, and also, by comparison with healthy subjects, less when autonomous than when socially-facilitated (13% vs 63%). Good interest in and responsiveness to people translated into better motivation for OOHU. She responded to others' requests for grasping and handling objects and used them to reinforce affiliations with people. Results were discussed in terms of a disruption of the formation of a specialized OOHU cerebral network in RS, partially compensated for by the favorably skewed X-inactivation, which among other effects permitted functional retention of the network segment incorporating social influence and motivation.
A theoretical analysis is presented in which the four major attachment patterns (A, B, C, and D) are viewed as adaptations to particular forms of early contingency experience. The author proposes that human infants analyze contingency experience on the basis of two computations of conditional probability, one prospective and one retrospective. Ideally, when these computations do not agree, the direction of disagreement provides information as to how the infant should adjust effective behavior and/or how potential contingent consequences should be redefined. The author also proposes that the specific patterns of insecure attachment (A, C, and D) are a result of parental responsiveness that is by nature inconsistent or out of balance and that the infant interprets this imbalance as his or her misperception of a balanced contingency. The observed symptoms of attachment insecurity are seen as consistent with specific attempts by infants to adjust behavior and/or discrimination according to the direction of imbalance in conditional probabilities they have experienced in interactions with their caretakers.
We have used the double pulp flap technique described by Buck-Gramcko for nail fold creation in 75 fingertips after separation of 38 complete syndactyly webs in 27 patients. The operative technique is described and the results are discussed. Nail patterns in these complex syndactyly webs are analysed and a classification is proposed.
This prospective study compares subjects following primary repair of flexor tendons in zone 2 using either controlled active motion or a modified Kleinert regime. A matched pairs design was employed, subjects being matched for gender, age and injury characteristics. Twenty-six pairs of subjects with 92 tendon injuries in 52 digits were assessed 12 weeks postoperatively in respect of range of motion and dehiscence. Outcomes were defined using the Strickland criteria. No statistically significant differences in respect of range of motion were demonstrated between the groups. Incidence of rupture, however, was significantly less in the modified Kleinert group (7.7%) than in the controlled active motion group (46%).
The influence of eye movements on hand use and pervasive stereotypies in Rett syndrome was studied, to better understand the developmental abnormality in this disorder. Nine patients in the post-regression phase were offered objects. As expected, the girls looked at the objects but usually did not reach for them. Nor were their characteristic hand stereotypies altered by such looking. But the occurrence of stereotypies was promoted by overall shifts in gaze, ie, eye movements in any direction. This finding may be relevant to the late-infancy loss of voluntary hand use in Rett syndrome associated with onset of pervasive stereotypies. It suggests a stage-specific regression to a level characteristic of normal 3-month-old infants who do not reach and grasp, but whose hand clasping and mouthing may be triggered by the perceptual consequences of exploratory eye movements and shifts in gaze.
The authors present a new theory of parental affect-mirroring and its role in the development of emotional self-awareness and control in infancy. It is proposed that infants first become sensitised to their categorical emotion-states through a natural social biofeedback process provided by the parent's 'marked' reflections of the baby's emotion displays during affect-regulative interactions. They argue that this sensitisation process is mediated (similarly to that of adult biofeedback training) by the mechanism of contingency-detection and maximising. Apart from sensitisation, affect-mirroring serves three further developmental functions: (1) it contributes to the infant's state-regulation; (2) it leads to the establishment of secondary representations that become associated with the infant's primary procedural affect-states providing the cognitive means for accessing and attributing emotions to the self; (3) it results in the development of a generalised communicative code of "marked' expressions characterised by the representational functions of referential decoupling, anchoring and suspension of realistic consequences. They consider the clinical implications of our theory, relating it to current psychodynamic approaches to the functions of parental affect-mirroring. Using their model they identify various types of deviant mirroring styles and speculate about their developmental consequences. Finally, they discuss what role their social biofeedback model may play as a mediating mechanism in the therapeutic process.