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Biomedical subjects

D Matthews

Publications and source records attributed to D Matthews.

At least 55 records · Page 3Linked to original sources
PubMed1995

Confirmation of genetic heterogeneity in familial psoriasis.

Psoriasis affects approximately 2% of the European population and is often familial. Linkage of a subset of psoriasis families to loci on chromosome 17q has recently been reported. We have studied members of a large multiply affected family from the north east of England and analysed genotypes for markers from 17q, including the polymorphic microsatellite markers AFM210xa5, AFM163yg1, AFM044xg3, AFMa353yg1, and AFM217yd19. Two point and multipoint analysis clearly show exclusion of linkage between the telomeric region of 17q and psoriasis in this family. This confirms the genetic heterogeneity of psoriasis and the existence of at least one other major psoriasis locus.

Chromosomes, Human, Pair 17↗
PubMed1994

Late effects of intraoperative radiation therapy on retroperitoneal tissues, intestine, and bile duct in a large animal model.

PURPOSE: The late histopathological effects of intraoperative radiotherapy (IORT) on retroperitoneal tissues, intestine, and bile duct were investigated in dogs. METHODS AND MATERIALS: Fourteen adult foxhounds were subjected to laparotomy and varying doses (0-45 Gy) of IORT (11 MeV electrons) delivered to retroperitoneal tissues including the great vessels and ureters, to a loop of defunctionalized small bowel, or to the extrahepatic bile duct. One control animal received an aortic transection and reanastomosis at the time of laparotomy; another control received laparotomy alone. This paper describes the late effects of single-fraction IORT occurring 3-5 years following treatment. RESULTS AND CONCLUSION: Dogs receiving IORT to the retroperitoneum through a 4 x 15 cm portal showed few gross or histologic abnormalities at 20 Gy. At doses ranging from 30-45 Gy, radiation changes in normal tissues were consistently observed. Retroperitoneal fibrosis with encasement of the ureters and great vessels developed at doses > or = 30 Gy. Radiation changes were present in the aorta and vena cava at doses > or = 40 Gy. A 30 Gy dog developed an in-field malignant osteosarcoma at 3 years which invaded the vertebral column and compressed the spinal cord. A 40 Gy animal developed obstruction of the right ureter with fatal septic hydronephrosis at 4 years. Animals receiving IORT through a 5 cm IORT portal to an upper abdominal field which included a defunctionalized loop of small bowel, showed a few gross or histologic abnormalities at a dose of 20 Gy. At 30 Gy, hyaline degeneration of the intestinal muscularis layer of the bowel occurred. At a dose of 45 Gy, internal intestinal fistulae developed. One 30 Gy animal developed right ureteral obstruction and hydronephrosis at 5 years. A dog receiving 30 Gy IORT through a 5 cm portal to the extrahepatic bile duct showed diffuse fibrosis through the gastroduodenal ligament. These canine studies contribute to the area of late tissue tolerance to IORT.

Anastomosis, Surgical↗
PubMed1994

Pathogenesis of glucose intolerance and diabetes mellitus in cirrhosis.

Glucose intolerance and diabetes mellitus are both prevalent in cirrhosis, yet the pathogenesis of impaired glucose metabolism remains unknown. Therefore insulin secretion (hyperglycemic clamp, +125 mg/dl), insulin sensitivity (euglycemic hyperinsulinemic insulin clamp, +10 microU/ml and +50 microU/ml), whole-body glucose oxidation (indirect calorimetry) and glucose turnover ([6,6-2H2]glucose isotope dilution) were evaluated in a homogenous group of cirrhotic patients with glucose intolerance (n = 7) or frank diabetes mellitus (n = 6). The results were compared with those obtained in control subjects (n = 8). In glucose-intolerant patients, whole-body glucose uptake (mainly reflecting glucose utilization by muscle) was significantly impaired in patients during both insulin infusions as a result of decreased stimulation of the two major intracellular pathways of glucose disposal--nonoxidative glucose disposal (i.e., glycogen synthesis) and glucose oxidation. Hepatic glucose production was normal in the basal state and was normally suppressed during stepwise insulin infusion (by 65% and 85%, respectively, p = NS vs. controls). Hyperglycemia-induced increases of plasma C-peptide concentrations were comparable to those in controls (p = NS). In diabetic patients, insulin-mediated glucose uptake was significantly reduced, mainly because of impaired non-oxidative glucose disposal. Glucose oxidation appeared to be reduced, too. Hepatic glucose production was significantly increased in the basal state (3.03 +/- 0.24 vs. 2.34 +/- 0.10 mg/kg min, p < 0.02) and during insulin infusion (+50 microU/ml: 0.67 +/- 0.17 vs. 0.13 +/- 0.08 mg/kg min, p < 0.05) compared with that in controls. Both the first and second phases of beta-cell secretion were significantly reduced in response to steady-state hyperglycemia (both p < 0.01 vs. control values). In conclusion, glucose intolerance in cirrhosis results from two abnormalities that occur simultaneously: (a) insulin resistance of muscle and (b) an inadequate response (even when comparable to that of controls) of the beta-cells to appropriately secrete insulin to overcome the defect in insulin action. Diabetes mellitus in insulin-resistant cirrhotic patients develops as the result of progressive impairment in insulin secretion together with the development of hepatic insulin resistance leading to fasting hyperglycemia and a diabetic glucose tolerance profile.

Adult↗
PubMed1994

Correlation between the results of a histopathological examination and the detection of abnormal brain fibrils in the diagnosis of bovine spongiform encephalopathy.

A statistical comparison was made between the results of the statutory neurohistopathological method for the post mortem diagnosis of bovine spongiform encephalopathy (BSE) and the detection of abnormal brain fibrils (SAF). A total of 773 suspect cases was examined by both methods; it comprised 531 animals born before the feeding of ruminant-derived protein to ruminant species was prohibited and 242 born after the ban. The relative sensitivities and specificities of the methods were calculated for the diagnosis of clinically suspected BSE. The agreement between the results of the methods was excellent for 331 of the cases born before the ban and for all the cases born after it. In these cases the samples were not autolysed. For the 200 cases in which autolysis was recorded there was poor agreement between the diagnostic methods and this was attributed to an apparently reduced specificity of the histopathological diagnosis in the autolysed material. Despite the potentially greater specificity of fibril detection in the diagnosis of scrapie-like disease, this study indicates that a reliance on fibril detection alone may result in some false negative diagnoses, probably owing to the inadequate sampling of the tissues.

Animals↗
PubMed1994

The prevention and diagnosis of infective endocarditis. The primary care provider's role.

Infective endocarditis, a microbial infection of the endocardium, is a complex multifaceted disease that may affect any organ system. Despite advances in diagnostic technology and treatment, overall mortality rates from infective endocarditis remain between 15-45%, and as high as 40-70% among the elderly. Explanations for the persistence of high mortality rates have focused on delays or errors in diagnosis. The classic diagnostic triad of fever, cardiac murmur, and positive blood cultures are not always present. Elderly patients often have more non-specific symptoms than do younger patients. Infective endocarditis should be considered in conditions dominated by the insidious onset of congestive heart failure, acute mental status or neurological changes, or the acute onset of arthralgias or myalgias. This article reviews the pathogenesis, epidemiology and etiology, risk factors, and clinical presentations of infective endocarditis, as well as current recommendations for antibiotic prophylaxis.

Aftercare↗
PubMed1994

Post therapy imaging in high dose I-131 radioimmunotherapy patients.

The biodistribution of a trace-labeled I-131 antibody is used to predict the biodistribution of a high dose I-131 antibody for therapy. Internal radiation dose estimates derived from the trace-labeled antibody have been used to determine the I-131 doses in a phase I escalating dose therapy trial for hematologic malignancy. To confirm the hypothesis that the distribution of a trace- and high-dose labeled antibodies are similar, both trace (7-11 mCi, 259-407 MBq) and high-dose (100-800 mCi, 3700-29600 MBq) I-131 radiolabeled antibody infusion were imaged in 12 patients who were treated for leukemia or lymphoma. With specialized imaging techniques using lead attenuation sheets, clearance data from organs were obtained from serial gamma camera images. Biological clearance half times of I-131 from both trace and therapy level doses were in agreement. An exception was a patient who developed human antimouse antibody before therapy, and subsequently had rapid clearance of the therapy dose. The method was feasible, yielded reproducible results, and provided critical data for relating therapy toxicity to radiation absorbed dose estimates.

Biophysical Phenomena↗
PubMed1993

Treatment of chronic post-traumatic dorsal subluxation of the distal ulna by hemiresection-interposition arthroplasty.

Twenty-four patients were evaluated for complaints of pain in the area of the distal radioulnar joint, decreased forearm rotation, and weakness of grip. All patients had a history of trauma to the involved wrist an average of 40 months prior to presentation. Six patients had undergone previous surgery that was unsuccessful. Twenty-three patients were available for follow-up evaluation at an average of 36 months following hemiresection-interposition arthroplasty. At that time, results were excellent in 13 patients, good in 4 patients, fair in 3, and poor in 3. Two patients developed symptoms of styloidcarpal abutment (poor results), one of whom was upgraded to an excellent result after undergoing a shortening osteotomy of the ulna.

Adult↗
PubMed1992

Sub-acute, transmissible spongiform encephalopathies: current concepts and future needs.

The first diagnosis of bovine spongiform encephalopathy (BSE) in the United Kingdom in 1986 was to stimulate the most intensive epidemiological study of any animal disease of all time in that country. It led also to the initiation of a broad-based research programme with an international flavour. This principally involved scientists and veterinarians in Europe (especially the United Kingdom) and the United States of America, especially those with experience of slow infections in general and experimental scrapie in particular. This final chapter highlights some of the significant discoveries made in the study of BSE and related diseases of this group but also emphasises the deficits in knowledge which need to be corrected before such diseases as scrapie in sheep and goats can be brought under control. The benefits resultant upon effective disease control will be manifest as improvement in animal production, welfare and, importantly, the removal of trading barriers currently in place to protect countries in which diseases such as BSE and scrapie do not exist. Of key importance is the development of a simple, cheap and effective diagnostic test for use in the live animal before the onset of clinical signs. This will be difficult since the nature of the causal agents is uncertain and none provokes either a detectable immune response or inflammatory reaction in the host. The earlier chapters, written by acknowledged specialists from around the world, deal with the specific diseases in detail and all present some of the most recent knowledge available. Here the authors emphasise the important role that major national and international agencies have in effecting the highest level of control possible in the absence of key information. International collaboration with countries in which these diseases exist, and as well as those where they are absent, is of paramount importance. It is essential that the BSE epidemic which has severely affected the cattle industry of the United Kingdom is not allowed to happen in developing countries. Whereas the former has implemented stringent control measures based on scientific knowledge and is well on the way to eradicating the disease, the latter could have much greater difficulty in establishing control. The answer is clear. BSE must be prevented from occurring elsewhere. To do that, knowledge of BSE and other members of the group should be widely dispersed and it is the purpose of this issue to do just that.

Animals↗
PubMed1991

Critically ill patients have high basal growth hormone levels with attenuated oscillatory activity associated with low levels of insulin-like growth factor-I.

OBJECTIVE: The aim was to study the relationship between growth hormone (GH) and insulin-like growth factor-I (IGF-I) in critically ill patients. DESIGN: Case-control study of critically ill patients admitted to the intensive care unit was carried out. PATIENTS: Six critically ill patients (51-78 years) who required ventilation and parenteral nutrition and six age, weight, height, and sex-matched healthy adults were studied. MEASUREMENTS: The patients and controls were studied for two 24-hour periods; the patients before and after starting parenteral feeding, and the controls during a 36-hour fast and when taking meals equivalent in calories and protein to the patients' parenteral feed. Serum GH was measured at 20-minute intervals and analysed by a pulse detection algorithm (Pulsar) and Fourier transformation. IGF-I was measured at 0, 12, and 24 hours. RESULTS: Patients had low serum IGF-I levels compared with controls, whether fasted or fed, despite having mean GH levels similar to fasted controls. For fasted patients vs fasted controls the mean (+/- 1 SD) GH levels were 4.5 +/- 2.0 vs 4.0 +/- 2.4 mU/l respectively, and IGF-I levels at the end of the fast were 0.17 +/- 0.11 vs 0.78 +/- 0.29 U/ml (P = 0.003). Patients showed elevated baseline GH levels compared with controls when fasted and during parenteral feeding (patients vs controls fasted 3.1 +/- 1.9 vs 0.8 +/- 0.5 mU/l, P = 0.01; patients vs controls fed 4.2 +/- 4.5 vs 0.5 +/- 0.04 mU/l, P = 0.028). Fourier transformation confirmed oscillatory GH levels in the controls, fasted or fed, but this activity was attenuated in the patients. Parenteral feeding had no effect on the GH profiles or IGF-I levels of patients, but controls showed greater mean GH levels during their fast than when fed. CONCLUSIONS: We have demonstrated that critically ill patients have low IGF-I levels associated with augmented baseline GH levels which show reduced oscillatory activity. The results would be compatible with the hypothesis that there is an adaptive change in critically ill patients away from the indirect effects of GH (stimulation of IGF-I production and anabolism) and toward the direct effects (lipolysis and insulin antagonism) which increase the availability of energy substrates. The pattern of GH levels seen in our patients may be important in this adaptation.

Abdomen↗
PubMed1991

Bovine spongiform encephalopathy.

Two years after the introduction of a slaughter policy for BSE, the author summarizes the development of the epidemic and introduction of Government controls. In conclusion, the risk to humans is discussed.

Abattoirs↗
PubMed1990

The role of private practitioners in accelerated lambing.

Sheep producers throughout the United States have begun using accelerated lambing programs to enlarge their net income by increasing the number of lambs produced per ewe per year. These new intensive systems have produced some unique problems and concerns. This article attempts to educate the veterinarian as to the justification for these programs. Areas in which veterinary intervention can greatly influence the success or failure of these new accelerated lambing systems are identified. Selection of ewe type, ultrasound pregnancy diagnosis, ram evaluation, specific flock health concerns, and critical ewe nutrition are discussed.

Animal Husbandry↗