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Biomedical subjects

C J Watson

Publications and source records attributed to C J Watson.

At least 19 recordsLinked to original sources
PubMed1992

A survey of complete denture prosthetics for the elderly, the handicapped and difficult patients.

A survey was carried out to establish information on the facilities and management of the elderly and the handicapped and to evaluate the treatment of the difficult edentulous patient in general dental practice. A postal questionnaire was sent to a total of 1090 dentists in three regions of England and Wales. There was a 50.4% response. Ninety-nine per cent of practitioners were able to treat the ambulant elderly, whereas only 72% offered treatment if the patient was wheelchair dependent. Ninety-six per cent of all respondents undertook domiciliary visits. All practitioners provided prosthetic treatment (complete and partial dentures) for the elderly, whereas fewer felt able to treat the physically and the mentally handicapped. There was less conservative and periodontal treatment provided than prosthetic treatment. A similar pattern was obtained in all three regions. Forty-seven per cent preferred to treat difficult complete denture patients privately, 44% under the NHS and 6% not at all. There were regional variations in the referral patterns of these difficult denture cases. The majority of respondents considered that there should be more opportunities for postgraduate education in prosthetic dentistry.

Aged↗
PubMed1992

Computed tomography in blunt abdominal trauma: an analysis of clinical management and radiological findings.

We have retrospectively assessed the computed tomography (CT) findings in 92 patients suffering severe blunt abdominal trauma. Surgical findings and clinical follow-up were correlated with the CT findings. In nine patients CT was first used after emergency surgery and provided baseline data which was useful for further management. In two patients CT did not demonstrate small hepatic lacerations seen during previous surgery. No deaths were recorded. In 16 patients surgery followed CT within 24 h; there was good correlation between the CT and operative findings in 10 patients. However, CT failed to detect significant solid organ injury in five patients and was misleading (false positive) in another patient. There were two deaths amongst these 16 patients. Sixty-seven haemodynamically stable patients were initially managed non-operatively. Fifteen of these 67 patients had normal CT examinations; only one had subsequent laparotomy (for reasons unconnected with the trauma) where no injury was detected; there were no deaths. Of the 52 patients with an abnormal CT examination, 43 were successfully managed non-operatively. There were three deaths, including one where an injury missed at CT contributed to the demise of the patient. After an initial trial of non-operative management, the remaining six patients went to surgery where there was good concordance with the CT findings except for one missed renal injury. Active non-operative management of blunt abdominal trauma is widely accepted in haemodynamically stable patients and this report shows how CT supports this policy of surgical restraint in such cases. However, on review CT missed 13 injuries in nine patients overall; stricter attention to technique and better equipment may lead to improved results in the future.

Abdominal Injuries↗
PubMed1992

Finite element stress and strain analysis of the bone surrounding a dental implant: effect of variations in bone modulus.

The long-term clinical performance of a dental implant is dependent upon the preservation of good quality bone surrounding the implant and a sound interface between the bone and the biomaterial. Good quality bone is itself dependent upon the appropriate level of bone remodelling necessary to maintain the bone density and the avoidance of bone microfracture and failure. Both processes are governed by the stress and strain distribution in the bone. In this study, a dental implant which had the same geometry as the Branemark system, but with a bioactive surface coating added to produce a direct bond to the bone, was analysed. A finite element stress and strain analysis has been carried out for a range of bone density distributions under axial and lateral loading. The predictions indicated that there was no evidence of strain shielding around the neck of the implant. With lateral loading, high values of von Mises stresses (18 M Pa) were predicted around the neck of the implant. A reduction in the elastic modulus of the bone around the neck of the implant by a factor of 16 only produced a twofold reduction in the peak stress. This resulted in stress levels capable of inducing fatigue failure in this much weaker bone. This analysis has demonstrated that it is extremely important to have good quality dense bone around the neck of the implant to withstand the predicted peak stresses of between 9 and 18 M Pa. Failure to achieve this after implantation and subsequent healing may result in local fatigue failure and resorption at the neck upon resumption of physiological loading.

Bone Density↗
PubMed1992

Computed tomography in abdominal trauma: an audit of usage and image quality.

The use and quality of computed tomography (CT) in the evaluation of blunt abdominal trauma has been assessed by a retrospective review of 122 patients referred in the first 8 years following the installation of CT of the body. The referral patterns were analysed, and the quality of the images was assessed, with particular reference to unsatisfactory (unacceptable or poor) images. Referrals increased over the 8 years following installation. A large proportion of these examinations were performed outside normal working hours (58/122, 48%). In 64 out of 122 (52%) of examinations the images were considered of unsatisfactory quality with inadequate use of intravenous contrast medium cited as the most common cause for unsatisfactory examinations. Image quality did not improve with time. Image quality was unsatisfactory in a larger proportion of those examinations performed outside normal working hours (35/58, 60%) than those during the routine working day (29/64, 45%), although this difference did not reach statistical significance (0.1 greater than p greater than 0.05). Fewer unsatisfactory examinations were produced by a system dedicated to body CT (31/74, 42%) than by a neuroradiological system (33/48, 69%) (p less than 0.01). The proportion of unsatisfactory abdominal examinations was lower when the CT study concentrated on the abdomen (26/65, 40%) than when multiple regions (head, chest, abdomen, etc.) were examined (38/57, 67%) (p less than 0.01). This audit revealed many unsatisfactory examinations. In order to complete the audit loop we have addressed many of the contributory factors. A new CT system now provides images of high quality and is used for all abdominal work. Guidelines, which describe an optimized technique, have been issued to radiographers and radiologists. In particular, we have emphasized that there is no place for a poorly supervised "quick look" at the abdomen following a cranial or thoracic study.

Abdominal Injuries↗
PubMed1991

Interaction of DNA-binding proteins with a milk protein gene promoter in vitro: identification of a mammary gland-specific factor.

The minimal 5' regulatory region of the sheep beta-lactoglobulin gene (BLG), as defined in transgenic mice, was used to identify nuclear factors which may be involved in milk protein gene expression in the lactating mammary gland. This 406bp promoter region was dissected into short, overlapping, double-stranded oligonucleotides to facilitate identification of the bound proteins. A variety of sites, for both known and previously undescribed DNA-binding proteins, are occupied in vitro. Some of these factors were investigated in detail. Two forms of nuclear factor I (NFI), which have different recognition site affinities, are present in nuclear extracts from lactating mammary gland and bind to at least 5 sites in this BLG control element. In addition, a factor (milk protein binding factor, MPBF) which is specific to extracts from both mouse and sheep lactating mammary gland binds to 3 BLG promoter sites and may be a milk protein gene transcription factor.

Animals↗
PubMed1991

Tongue control of upper complete dentures: a clinical hint.

The role of the tongue in aiding upper denture retention is well recognised by clinicians, but this information is not always related to the patient. This paper describes a simple method of diagnosing the problem and training patients to control their maxillary denture during function, particularly when chewing food.

Denture Retention↗
PubMed1991

Early abdominal complications following heart and heart-lung transplantation.

In the first 11 years of the heart and heart-lung transplantation programme at Papworth Hospital, Cambridge, 356 patients underwent heart transplantation, and 73 patients received both heart and lungs. Out of 429 patients 41 (9.5 per cent) developed abdominal complications within the first 30 days, and 20 of the 41 required surgery. The complications included pancreatitis (10), peptic ulceration (8), and pseudo-obstruction (8), in addition to colonic perforation and small bowel obstruction. When laparotomy was performed it was well tolerated. This paper supports the view that successful management of abdominal complications following transplantation requires prompt diagnosis and treatment. Where doubt exists in the presence of an acute abdomen, laparotomy is the appropriate way to establish a definitive diagnosis.

Acute Disease↗
PubMed1991

Surgical restraint in the management of liver trauma.

Previous experience in Cambridge in the management of liver trauma has led to the evolution of a protocol for surgical intervention to secure control of haemorrhage from the injured liver. We report 80 cases of liver trauma including 12 who were initially managed non-operatively; three of these subsequently required operation. Of the 80, all but five suffered blunt abdominal trauma. Perihepatic packing was used to manage 29 patients, of whom 21 were initially treated elsewhere before being transferred to Cambridge. Six of these required a hemihepatectomy at subsequent exploration. Of the 39 patients who underwent urgent laparotomy and definitive surgery, 11 (28 per cent) died; only three out of 29 (10 per cent) died after initial packing. Only one death from hepatic complications occurred after packing and subsequent transfer.

Hemorrhage↗
PubMed1991

Computer graphics representation of a statistical model used with computer-aided diagnosis.

A description of computer graphics of a multidimensional model that is used with computer-aided diagnosis or prognosis is presented. The model is discussed and computer graphics of the model are developed. The computer graphics are suitable as visual supplements for presenting the computer-aided diagnostic model to individuals who may be inexperienced in multivariate statistics.

Animals↗
PubMed1991

Surgical management of the atrophic edentulous ridge--a prosthetic view.

The vast majority of edentulous patients manage to wear complete dentures with relative ease. There are however a small group of patients described as "Denture Cripples" by Hopkins, Stafford and Gregory (1980), for whom the provision of complete dentures using conventional means has proved impossible. Clinical examination usually reveals marked atrophy of the alveolar ridge, the prominence of sharp bony ridges and an atrophic denture bearing mucosa. The patient complains of loose, painful dentures and an inability to masticate a normal diet. The patients can often be helped by correcting errors on their presenting dentures or by minor surgical procedures such as frenectomy or smoothing sharp bony ridges. Other patients present with such extreme ridge atrophy that major surgery may need to be considered. This paper reviews three types of surgery commonly used to help the prosthetist rehabilitate the patient, namely vestibuloplasties, ridge augmentations and implants.

Alveolar Bone Loss↗
PubMed1990

Expression of adenovirus type 2 DNA polymerase in insect cells infected with a recombinant baculovirus.

Sequences encoding adenovirus type 2 DNA polymerase were placed under control of the polyhedrin promoter and inserted into the baculovirus Autographa californica nuclear polyhedrosis virus by homologous recombination. Insect cells infected with the recombinant virus produced substantial amounts of the adenovirus type 2 DNA polymerase protein which was functional in both DNA polymerase and replication initiation reactions. Thus, the baculovirus expression system can provide active adenovirus type 2 DNA polymerase that is produced in quantities suitable for biochemical and structural analysis.

Adenoviruses, Human↗
PubMed1990

A clinical study of the Brånemark dental implant system.

A clinical study using the Brånemark dental implant system was carried out on 13 patients aged 41 to 68 years. Clinical and psychological effects of treatment were assessed at 6-monthly intervals over a period of 3 years by means of a clinical examination, a personality assessment using Cattell's 16 PF Questionnaire and a general subjective questionnaire. Six per cent of implants failed to osseointegrate. Fifty per cent of bridges became loose, but remained stable after retightening. A similar percentage of fractures occurred, mainly teeth separating from acrylic gumwork. There was some soreness of peri-implant mucosa, particularly on cleaning. Despite these problems, there was considerable evidence of improved well-being of patients, who felt more secure following treatment and, as a result, their personal and social relationships improved.

Adult↗