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R Richards

Publications and source records attributed to R Richards.

At least 37 records · Page 2Linked to original sources
PubMed2000

Views of academic dentists about careers in academic dentistry in the United Kingdom.

The aim of this paper is to report the views of academic dentists about careers in academic dentistry assessed by method of a postal questionnaire survey. The subjects of the survey were dentists in academic posts in the United Kingdom. The incentives in pursuing an academic career which respondents rated most highly were the opportunity to teach and the variety of work in an academic career. The greatest disincentives were competing pressures from service work, teaching and research, and the difficulty of getting research grants. Many would like to spend more time on research and less on service work and teaching. The length of time required for training, and the quality of training, was a concern, particularly for junior academics. Most respondents rated the enjoyment of their job highly but scored much lower on satisfaction with the time their job left for domestic and leisure activities. By contrast with academic medicine, in academic dentistry there is typically greater emphasis on teaching and less on research. In conclusion, the balance of activities in academic posts, particularly between service work, teaching and research, needs to be regularly reviewed. The development of a more structured training programme for junior academics, which does not disadvantage academic dentists when compared with their NHS colleagues, may be required.

Attitude of Health Personnel↗
PubMed2000

A 500-kb region on chromosome 16p13.1 contains the pseudoxanthoma elasticum locus: high-resolution mapping and genomic structure.

We have recently mapped the genetic defect underlying pseudoxanthoma elasticum (PXE), an inherited disorder characterized by progressive calcification of elastic fibers in skin, eye, and cardiovascular system, to chromosome 16p 13.1. Here we report further data on the fine-mapping and genomic structure of this locus. Haplotype analysis of informative PXE families narrowed the locus to an interval of less than 500 kb located between markers D16B9621 and D16S764. Three overlapping YAC clones were found to cover this region through YAC-STS content mapping. An overlapping BAC contig was then constructed to cover this interval and the surrounding region. About 80% of this chromosomal region has been fully sequenced using the BAC shotgun technique. Gene content and sequence analysis predicted four genes (MRP1, MRP6, PM5, and a novel transcript) and two pseudogenes (ARA and PKDI) within this interval. By screening a somatic cell hybrid panel we were able to precision-map the breakpoint of Cy185 and the starting point of a chromosomal duplication within 20 kb of BAC A962B4. The present data further refine the localization of PXE, provide additional physical cloning resources, and will aid in the eventual identification of the genetic defect causing PXE.

Adult↗
PubMed2000

Mutations of the gene encoding the transmembrane transporter protein ABC-C6 cause pseudoxanthoma elasticum.

We recently published the precise chromosomal localization on chromosome 16p13.1 of the genetic defect underlying pseudoxanthoma elasticum (PXE), an inherited disorder characterized by progressive calcification of elastic fibers in skin, eye, and the cardiovascular system. Here we report the identification of mutations in the gene encoding the transmembrane transporter protein, ABC-C6 (also known as MRP-6), one of the four genes located in the region of linkage, as cause of the disease. Sequence analysis in four independent consanguineous families from Switzerland, Mexico, and South Africa and in one non-consanguineous family from the United States demonstrated several different mis-sense mutations to cosegregate with the disease phenotype. These findings are consistent with the conclusion that PXE is a recessive disorder that displays allelic heterogeneity, which may explain the considerable phenotypic variance characteristic of the disorder.

ATP-Binding Cassette Transporters↗
PubMed2000

The findings in paediatric obstetric brachial palsy differ from those in older patients: a suggested explanation.

An EMG and nerve-conduction-study protocol has been developed and used in all patients with brachial plexus lesions since 1985. The findings of EMG and nerve-conduction studies in obstetric brachial palsy (OBP) mostly suggest a falsely optimistic prognosis. To analyse this, all subjects were selected with complete avulsion of both roots C5 and C6 and/or complete rupture of the upper trunk verified during operation from a group of 162 infants with OBP (aged 4 to 14 months) and a group of 184 child and adult patients (aged 6 to 74 years) with a traumatic brachial plexus lesion. Fourteen infants, approximately 4 months old, with OBP, and 19 adults (aged 16 to 30 years) met the selection criteria. The infants from the group with OBP had at 4 months a nearly normal recruitment pattern of motor units in the biceps brachii and deltoid muscles, with little or no denervation. However, in the older group with traumatic brachial palsy, the same lesion caused complete denervation of both muscles. From the group with OBP, a third group (N=3) with the same lesion plus an additional lesion of C7 or a rupture of the middle trunk was selected. This additional lesion resulted in nearly complete denervation of both muscles. This means that C7 largely contributes to the innervation of both muscles at the time of birth, but this innervation is lost during later life in normally developing individuals (apoptosis). A central mechanism might be responsible for the clinical palsy and later spontaneous improvement which is always found in the infants with OBP.

Adolescent↗
PubMed2000

Long-term follow-up of Barrett's high-grade dysplasia.

OBJECTIVE: The management of Barrett's high-grade dysplasia (HGD) remains controversial. The aims of this study were to evaluate prospectively the outcome of unifocal HGD (uHGD) in patients with Barrett's esophagus, and to determine demographic and endoscopic features predictive of progression to multifocal HGD (mHGD) and/or adenocarcinoma. METHODS: Consecutive Barrett's patients in whom uHGD was found at initial endoscopy or during surveillance underwent intensification of medical treatment and repeat endoscopy. The study endpoint was progression to mHGD or adenocarcinoma or HGD in conjunction with a dysplasia-associated lesion or mass (DALM). HGD diagnosis was confirmed by a second, blinded pathologist. RESULTS: A total of 15 Barrett's patients with uHGD met inclusion criteria and have been prospectively followed for a mean +/- SD of 36.8 +/- 23.2 months. All were white and male, with a mean age +/- SD of 61.4 +/- 14.9 yr. Barrett's length varied from 1 to 13 cm (mean, +/- SD, 6.8 +/- 4 cm). Overall, eight (53.3%) uHGD progressed: four of 15 (26.7%) to frank cancer between 17 and 35 months of follow-up, two of 15 (13.3%) to mHGD with DALM in conjunction with one or more foci of possible intramucosal cancer after 12-91 months of follow-up, one of 15 (6.7%) to mHGD with a focus of possible intramucosal cancer after 14 months, and one of 15 (6.7%) to mHGD after 29 months. Seven of 15 (46.7%) uHGD have regressed, five to no dysplasia and two to LGD, over the course of follow-up ranging from 24 to 73 months (mean +/- SD, 43.3 +/- 19.9). All three patients with short-segment Barrett's esophagus with uHGD regressed. Fisher's exact test revealed that Barrett's length > or =3 cm and presence of hiatal hernia approached significance (p < 0.08) in predicting uHGD progression to mHGD/DALM/cancer. However, use of the log-rank test to account for differences in length of follow-up show no significance for hiatal hernia or Barrett's length. CONCLUSIONS: Barrett's uHGD has a high risk for progressing to mHGD or cancer. Justification of an observational approach to uHGD should be discouraged. Markers of uHGD progression, as well as regression, are needed.

Adenocarcinoma↗
PubMed2000

The human leukocyte antigen HLA DRB3*020/DQA1*0501 haplotype is associated with Graves' disease in African Americans.

Information on genetic susceptibility to Graves' disease in African Americans is limited. We studied DRB1, DQB1, DRB3 subtypes, DQA1*0501, DQA1*0201, and CTLA-4 polymorphisms in 49 African American patients with adult onset Graves' disease and 47 racially-matched controls using PCR-based sequence-specific priming methods. There were no significant differences in DRB1 or DQB1 allelic frequencies or CTLA-4 polymorphisms between patients and controls. However, we found that the frequency of DRB3 was significantly increased in the patients (75.5% vs. 57.4%, P = 0.006, X2 = 3.52), especially for the DRB3*0202 subtype (53.1% vs. 23.4, P = 0.003, X2 = 8.91). In this one respect, the finding was in concordance with our previous observations in Caucasian patients with adult-onset Graves' disease. In addition, whereas the frequency of DQA1*0501 was increased (P = 0.018, X2 = 5.63) in our patients, the haplotype of DRB3/DQA1*0501, or DRB3*0202/DQA1*0501 was found to be more strongly associated (P = 0.008, X2 = 7.0; P = 0.0008, X2 = 11.34, respectively). These data suggest that DRB3*0202, particularly when found with DQA1*0501 in a haplotype is a susceptible gene(s) for Graves' disease in adult African Americans. Considering these data with those in Caucasian patients, our results would suggest that the primary Graves susceptible locus is likely DRB3 and not DRB1.

Abatacept↗
PubMed2000

Laser scanning of the ear identifying the shape and position in subjects with normal facial symmetry.

The objective of the present study was to discover if dimensional measurements of the ear could be determined with a laser scanning technique and whether or not the location of landmarks of the ear could be reliably measured with respect to those on the midline of the face. Computer-generated images were created from laser scans of 20 subjects. Dimensional measurements were made between landmarks on the ear and face. Differences between repeated dimensional measurements of the ear were very small, as were those measurements made between landmarks on the ear to the midline of the face. Differences between dimensions of the left and right ears were observed, but were of a small magnitude. The results suggest that the dimensions of the ear and its position with respect to landmarks in the midline of the face can be reliably measured on normal subjects and that laser scanning is a useful technique for planning and monitoring facial reconstruction of the ear.

Adolescent↗
PubMed1999

Junior doctors' views about careers in academic medicine.

OBJECTIVE: To investigate junior doctors' views about careers in academic medicine. DESIGN: Postal questionnaire survey. SETTING: National Health Service in England. SUBJECTS: Doctors in university posts at specialist registrar level, Medical Research Council and Wellcome Trust training fellows, and specialist registrars in National Health Service posts. RESULTS: Incentives to pursue an academic career which respondents rated as strong related to the challenge of research and the intellectual environment of research units. The strongest disincentives were perceived difficulties in obtaining research grants and uncertainty regarding pay parity with National Health Service colleagues. Medical Research Council and Wellcome fellows had much more protected research time than other academic doctors but were less satisfied with their clinical training. Academic doctors who were not fellows reported spending less than half their time on research and the great majority agreed that their research suffers when there is pressure on the service side. CONCLUSIONS: The job content of academic posts should be kept under regular review to ensure that clinical service pressures do not inappropriately erode research time while also ensuring that postholders have adequate clinical training. Training programmes need flexibility to accommodate the needs of clinical academics in their progress through higher specialist training.

Attitude of Health Personnel↗
PubMed1999

A prospective study of computer-aided design and manufacture of titanium plate for cranioplasty and its clinical outcome.

The use of computerized three dimensional imaging and automated milling of models to produce accurate titanium plates for the reconstruction of craniofacial defects is described. A total of 148 patients have had extensive calvarial defects repaired using this (computer aided design and manufacture) technique developed in our unit. Of these, 141 were repaired secondarily (delayed cranioplasty), whilst seven were repaired immediately following craniectomy (single stage cranioplasty). All cases were assessed for accuracy of fit, restoration of natural skull contour and aesthetics. Seventy-two patients were reviewed after 1 year to determine the effect on adverse preoperative symptoms. Of the plates 97% had an excellent or good intraoperative fit. The modal insertion time was only 15 minutes. Postoperatively 98% resulted in the restoration of natural skull shape and symmetry. After 1 year, 82% of patients had complete resolution or diminution in severity of the adverse symptoms. A staphylococcus infection necessitated the temporary removal of one plate.

Adolescent↗
PubMed1999

Leadership behaviors for successful university--community collaborations to change curricula.

PURPOSE: What constitutes effective leadership in a collaborative effort to achieve enduring curricular and student career changes? This question was investigated as part of a larger evaluation of the W. K. Kellogg Foundation's Community Partnership Health Professions Education, a five-year initiative involving projects at seven sites. The goal was to produce more primary care health providers by making enduring curricular change. METHOD: Data were collected from participants with respect to predictors of project success and leaders' use of 16 behaviors via telephone interviews, mailed surveys, and focus groups. Focus groups also gathered project leaders' views of skills and knowledge necessary for effective leadership. RESULTS: Leadership strategies associated with positive outcomes were: consistent leader; use of multiple cognitive frames, especially a human resource frame; use of a broad range of leadership behaviors, particularly participative governance and cultural influence; and a majority of community representatives on the partnership board. The primary leader, compared with a leadership team, is most influential in achieving positive outcomes. CONCLUSION: Effective leaders use a broad array of behaviors, but particularly emphasize the use of participative governance and culture/value-influencing behaviors. In addition, the more frequent use of these behaviors compared with the use of organizational power behaviors is important. It is helpful to perceive the project from a human-relations frame and at least one other frame. Using a leadership team can be helpful, especially in building coalitions, but the importance of the primary leader's behaviors to project outcomes is striking.

Academic Medical Centers↗
PubMed1999

Modeling the interactions of particulates with epithelial lining fluid antioxidants.

Oxidative stress may be a fundamental mode of injury associated with inspired particles. To examine this, we determined the ability of three carbon black particles (CBPs; M120, M880, and R250) and two forms of silicon dioxide, amorphous (Cabosil) and crystalline (DQ12) quartz, to deplete epithelium lining fluid antioxidant defenses. Single and composite antioxidant solutions of uric acid, ascorbic acid (AA), and reduced glutathione (GSH) were examined in the presence of particle concentrations of 150 microgram/ml. Uric acid was not depleted by any particle considered. AA was depleted in a near-linear fashion with time by the three different CBPs; however, AA depletion rates varied markedly with CBP type and decreased in the presence of metal chelators. An initially high GSH depletion rate was noted with all CBPs, and this was always accompanied by the appearance of oxidized glutathione. Exposure to Cabosil or DQ12 did not result in the loss of GSH. Together, these data demonstrate that particle type, size, and surface area are all important factors when considering particle-antioxidant interactions in the airways.

Air Pollutants↗
PubMed1999

Validation of computer-assisted manufacture of titanium plates for cranioplasty.

We have constructed 300 titanium cranioplasty plates, over 150 cases using a computerised technique, the remainder by external impression. The clinical follow-up of these cases over 8 years has shown consistently good results that justify our simple low-cost method of manufacturing these plates. Both techniques require the provision of a model on which to construct the plate. In the traditional technique, an approximate model is derived from the resected bone or a direct impression of the defect over the patient's scalp. Using the computerised technique, a more accurate model of the defect and the surrounding bone is milled in polyurethane foam from cross-sectional computerised tomographic (CT) scans. Sheet titanium is pressed to shape from a design outlined on a counterdie. The subsequent stages of the plate construction are then the same for both methods. This study describes the stages of the model manufacture, the validation of its accuracy and the plate construction that follows. Use of the computerised method has resulted in a reduction of errors, enabling the manufacture of a smaller plate than was possible previously. It has also enabled design changes through the achievement of greater accuracy in fit.

Bone Plates↗
PubMed1998

The use of computer-generated three-dimensional models in orbital reconstruction.

In this paper we describe the application of three-dimensional (3D) imaging and computer-generated models in the management of orbital deformity. The technique was found to be particularly useful in posttraumatic deformity and fibrous dysplasia involving the orbit. Further application was found in cases of radiation hypoplasia, high facial cleft, and facial atrophy. Funding restrictions necessitate appropriate selection of cases when using new and expensive 3D imaging rather than traditional and less expensive methods. To remain within a realistic budget only those patients who will clearly benefit from the third dimension compared with traditional methods of assessment and management should be selected. These include patients requiring precise reduction or secondary reconstruction in which there is a matched normal anatomical component for comparison. This application is also only beneficial where the planned reconstruction is dimensionally stable.

Adolescent↗
PubMed1998

Diplopia following transconjunctival blepharoplasty.

The resurgence of popularity of the transconjunctival approach to lower eyelid fat removal as a component of cosmetic blepharoplasty has been highlighted by a number of publications in recent years. There has been, however, minimal discussion in the literature of the complications of this procedure. Although the mechanism of muscle injury is similar in transcutaneous and transconjunctival surgery, there is a much more direct route to the inferior extraocular musculature via the latter approach. Herein, we present a series of six patients with diplopia status post-transconjunctival lower eyelid blepharoplasty referred to the Manhattan Eye, Ear, and Throat Hospital for evaluation. Transconjunctival lower lid blepharoplasty was performed as a primary procedure in four patients and as a secondary procedure following transcutaneous blepharoplasty in two patients. Patients were evaluated with ocular examination and orthoptic measurements. Magnetic resonance imaging was obtained in two cases. The inferior rectus and inferior oblique muscles were found to be equally injured in these cases (4 of 6), and the lateral rectus was encountered in one case. Two patients required strabismus surgery to correct their diplopia, whereas four patients improved with observation alone. The possible etiologies of postoperative diplopia following transconjunctival lower lid blepharoplasty are manifold. Mechanisms of extraocular muscle injury may include intramuscular hemorrhage and edema, cicatricial changes within the muscle, and accidental incorporation of extraocular muscle in closure of orbital septum. Avoidance of these complications is probably best achieved through intimate understanding on the part of the surgeon of eyelid anatomy from the transconjunctival perspective.

Adult↗
PubMed1997

A simple procedure for sulfation and 35S radiolabelling of paralytic shellfish poisoning (PSP) gonyautoxins.

A method is described to sulfate PSP toxins at various positions in the molecule and to prepare 35S labelled compounds using H2(35)SO4 in the presence of dicyclohexylcarbodiimide (DCC). The 11-sulfates of saxitoxin and neosaxitoxin, known as gonyautoxins, are often the most abundant of the PSP toxins in algae and contaminated shellfish. Receptor site binding and antibody assays based on these analogues should, therefore, better reflect toxicity than those in which saxitoxin is used. Although the specific activity of 35S-gonyautoxins is lower than that of commercially available 3H-saxitoxin, the label is strongly bound and is not lost through proton exchange with water as occurs with tritiated saxitoxin. The labelling procedure is rapid, inexpensive and can be done on a small scale. Sulfate can be removed from the 11-position of GTX's in methanolic-HCl and from the 21-position by mild acid hydrolysis and H2(35)SO4 added in 5-10-fold excess. Addition or exchange occurs rapidly on mixing DCC in dimethylformamide with dry toxin and sulfate. Reaction conditions were optimized and reaction products identified by capillary electrophoresis, autoradiography and ionspray mass spectrometry. Together with methods for selective removal of sulfate, the sulfation reaction provides an additional way to prepare some of the naturally occurring derivatives of saxitoxin, many of which are sulfates.

Animals↗
PubMed1997

Remote electronic blood release system.

BACKGROUND: The Hunter Area Pathology Service provides transfusion services to 4 metropolitan and 11 rural hospitals in Australia. To improve blood availability, conserve blood stocks, and reduce crossmatch-to-transfusion ratios, a networked electronic blood release system (EBRS) has been developed for computer cross-matching within the laboratory and at sites remote from the transfusion laboratory. It is innovative, in that non-laboratory staffs have been trained to release computer-matched blood at remote hospitals without transfusion laboratories. STUDY DESIGN AND METHODS: The EBRS software was tested and validated according to the Australian software standards AS 3563.1 and 3563.2 (1991). Over 7000 units were released by the EBRS in a laboratory trial conducted in conjunction with the conventional immediate-spin crossmatch. A further, 12-month study was conducted within the laboratory before the staged implementation of the EBRS at the remote hospitals. RESULTS: The EBRS has resulted in 1) a 25-percent reduction in the number of units requested by the medical staff, resulting from the reduction in time needed to provide compatible blood due to the elimination of the serologic crossmatch; 2) better blood stock management (reducing outdated red cell units by 30%); and 3) significant savings in laboratory workload (savings of approximately 100 hours/month). In addition, the rapid availability of computer-crossmatched red cells in emergency situations has enhanced patient safety. CONCLUSION: The EBRS is a safe and efficient means of providing red cells within the laboratory and at remote hospitals without laboratory services.

Blood Banks↗