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Biomedical subjects

D Bates

Publications and source records attributed to D Bates.

At least 37 records · Page 2Linked to original sources
PubMed1998

Yeast adaptation on softwood prehydrolysate.

Several strains and genera of yeast, including Saccharomyces cerevisiae D5A, Pachysolen tannophilus, S. cerevisiae K-1, Brettanomyces custersii, Candida shehatae, and Candida acidothermophilum, are screened for growth on dilute acid-pretreated softwood prehydrolysate. Selected softwood species found in forest underbrush of the western United States, which contain predominantly hexosan hemicellulose, were studied. This phase of the work emphasized debarked Douglas fir. The two best initial isolates were gradually selected for improved growth by adaptation to increasing prehydrolysate concentrations in batch culture, with due consideration of nutrient requirements. Microaerophilic conditions were evaluated to encourage tolerance of pretreatment hydrolysate, as well as ethanol product. Adaptation and simultaneous saccharification and fermentation (SSF) results are used to illustrate improved performance with an adapted strain, compared to the wild type.

Adaptation, Physiological↗
PubMed1998

Parotid and submandibular sialadenitis treated by salivary gland excision.

BACKGROUND: The purpose of the present study was to compare and contrast the clinicopathological features and treatment outcome of chronic sialadenitis involving the parotid and submandibular glands, among patients who were treated by excision of the affected gland. METHODS: In a series of 88 patients treated over an 8-year period, 47 had parotid sialadenitis and 41 had submandibular sialadenitis. In the parotid group, 63% of patients were symptomatic for longer than 6 months compared with 27% in the submandibular group. Calculi were implicated in the disease process in 24% of patients with parotid sialadenitis, compared with 73% of patients with submandibular disease. RESULTS: Patients with parotid sialadenitis had superficial (n = 14) or near-total parotidectomy (n = 35), while those with submandibular sialadenitis underwent total gland excision. Complications occurred twice as frequently in the parotidectomy group. The rate of temporary facial nerve weakness was 29% after parotidectomy while marginal mandibular nerve dysfunction occurred after 12% of submandibular excisions. Both procedures were highly effective in permanently relieving the symptoms of sialadenitis. CONCLUSIONS: Parotid sialadenitis is infrequently associated with stones and tends to run a longer course before surgical intervention is necessary. Submandibular sialadenitis usually presents earlier, is secondary to calculi and requires early intervention.

Chronic Disease↗
PubMed1998

Neurology and the kidney.

Renal failure is relatively common, but except in association with spina bifida or paraplegia it is unlikely to occur as a result of disease of the CNS. Renal failure, however, commonly affects the nervous system. The effects of kidney failure on the nervous system are more pronounced when failure is acute. In addition to the important problems related to renal failure there are both acquired and genetically determined diseases which may affect the kidney and the brain. Those acquired diseases include the vasculitides, the paraproteinaemias, and various granulomatous conditions (considered in other chapters of Neurology and Medicine). In two of the most commonly encountered genetically determined diseases, Von Hippel-Lindau disease and polycystic kidney disease, location of pathogenic mutations will provide improved screening programmes and, possibly, allow therapeutic intervention. Uraemia may affect both the central and peripheral nervous systems. Whereas the clinical features of uraemia are well documented, the pathophysiology is less well understood and probably multifactorial. Uraemic encephalopathy, which classically fluctuates, is associated with problems in cognition and memory and may progress to delirium, convulsions, and coma. The encephalopathy may initially worsen with periods of dialysis and almost certainly relates to altered metabolic states in association with ionic changes and possibly impaired synaptic function. Renal failure may affect the peripheral nervous system, resulting in a neuropathy which shows a predilection for large diameter axons. This may be reversed by dialysis and transplantation. The myopathy seen in renal failure, often associated with bone pain and tenderness, is similar to that encountered in primary hyperparathyroidism and osteomalacia. Dialysis itself is associated with neurological syndromes including the dysequilibrium syndrome, subdural haematoma, and Wernicke's encephalopathy. Dialysis dementia, which was prevalent during the 1970s, has reduced in frequency with the use of aluminium free dialysate. With the introduction of transplantation and the concomitant use of powerful immunosuppressive drugs, the pattern of neurological problems encountered in renal replacement therapy has shifted. Five per cent of patients develop nerve injuries during renal transplantation, and up to 40% of patients experience neurological side effects from cyclosporine. Furthermore, CNS infections, often fungal in type, have been reported in up to 45% of transplant patients coming to postmortem. The nature of the involvement of neurologists with their nephrology colleagues is therefore evolving.

Brain↗
PubMed1998

Standards of laboratory practice: antiepileptic drug monitoring. National Academy of Clinical Biochemistry.

Discussion and development of standards for appropriate monitoring led to the following key recommendations for ordering, sampling, and analyzing antiepileptic drugs: Monitoring should usually be done on trough specimens after steady-state has been reached and always with an appropriate medical indication; non-steady-state concentrations may be indicated in selected situations. Monitoring of free phenytoin and free valproic acid is indicated in specific situations and should be done in serum. The metabolite of primidone, phenobarbital, should be measured concurrently with parent drug, but the active metabolite of carbamazepine does not need to be monitored unless the patient is exhibiting an unusual toxic response that cannot be otherwise explained. Assays used for antiepileptic drug monitoring should display a long-term CV of <10% and preferably <5%. Subtherapeutic and supratherapeutic drug concentrations should be investigated on a regular basis as part of a quality assurance process.

Anticonvulsants↗
PubMed1997

New variant Creutzfeldt-Jakob disease: neurological features and diagnostic tests.

BACKGROUND: In April, 1996, ten cases of Creutzfeldt-Jakob disease (CJD) with an apparently new clinicopathological phenotype were published and it was suggested that these new variant cases (nvCJD) might be causally linked to bovine spongiform encephalopathy (BSE). There have now been 21 cases of nvCJD in the UK and one case in France. We report clinical features and diagnostic test results of the first 14 cases of nvCJD in the UK. METHODS: Case ascertainment of CJD was mainly by direct referral from neurologists and neuropathologists. Clinical and investigate details were obtained by interview with patients' relatives and by examination of case notes. Ten cases in this report were examined while alive. Prion protein (PrP) gene analysis was carried out with informed consent from the patient or from a relative. The diagnosis of nvCJD was established histologically. FINDINGS: Eight cases were women. Mean age at onset of symptoms was 29 (16-48) years and the median duration of illness was 14 (9-35) months. All patients had early psychiatric symptoms, most often depression, and 13 were seen by a psychiatrist early in the clinical course. Eight patients developed early sensory symptoms which were persistent and often painful. Neurological signs, including ataxia and involuntary movements, developed in all cases and towards the end of the illness, most had akinetic mutism. The electroencephalogram was abnormal in most patients but typical periodic complexes of CJD were not seen in any case. Cerebral imaging was usually normal or showed non-specific abnormalities; in two cases magnetic-resonance imaging scans showed high signal in the thalamus. INTERPRETATION: Clinical features in these cases are similar and relatively distinct from other forms of CJD, suggesting that this is a new clinical phenotype consistent with a single strain of infectious agent. There is, however, some overlap with atypical cases of sporadic CJD, and the diagnosis of nvCJD remains dependent on neuropathological confirmation.

Adolescent↗
PubMed1997

Multiple intracerebral intravascular papillary endothelial hyperplasia.

Intravascular papillary endothelial hyperplasia (IPEH) is a rare benign reactive lesion usually found in thrombosed subcutaneous blood vessels. It uncommonly occurs in the central nervous system and may be mistaken for a more malignant type of tumour such as angiosarcoma. We present a first case of multiple IPEH occurring intracranially in a 51-year-old woman. She developed neurological compromises secondary to the mass affect of the haematoma arising from one of the lesions. Prompt surgical evacuation of the haematoma stabilized her condition. Surgical treatment, pathological findings, radiographic characteristics, and a review of the literature are presented.

Brain Diseases↗
PubMed1997

Persistent vegetative state and brain stem death.

Interest in the persistent vegetative state has focused on the accuracy of diagnosis and prognosis. Retrospective studies in both adult and paediatric groups have raised questions about the most appropriate clinical methods to diagnose patients in the vegetative state and about the length of time before recovery from such a state can be regarded as hopeless. Although no absolute answers have been forthcoming, the debate engendered by the work has been informative and the need for further prospective studies is apparent. Following the publication of guidelines on the management of patients in the vegetative state, the views of physicians in the USA and Europe have been sought in relation to ethical problems and, although they highlight some areas of inconsistency, they show the potential for consensus. Clinically, the field of brain stem death is reasonably defined and consistently managed but the search for methods of technical confirmation of diagnosis continues. It is suggested that the use of magnetic resonance imaging and angiography might provide additional confirmatory evidence.

Animals↗
PubMed1997

Sound movement detection deficit due to a brainstem lesion.

Auditory psychophysical testing was carried out on a patient with a central pontine lesion involving the trapezoid body, who presented with a deficit in sound localisation and sound movement detection. A deficit in the analysis of time and intensity differences between the ears was found, which would explain the deficit in detection of sound movement. The impaired detection of sound movement, due to a lesion interfering with convergence of auditory information at the superior olive, suggests this structure to be critical for human sound movement analysis.

Audiometry, Pure-Tone↗
PubMed1997

Transient focal neurological deficit in sarcoidosis.

Sarcoidosis presents only infrequently with stroke or focal neurological deficit and recurrent focal neurological deficit is rarer still. This case report describes a patients presenting with episodic non-fluent dysphasia of abrupt onset occurring during a period of 18 months without evidence of seizure activity or macroscopic granulomatous collection. The case illustrates that the presentation of neurosarcoidosis may mimic classic reversible ischaemic neurological deficit.

Adult↗
PubMed1996

The incidence of diabetes mellitus in an English community: a 20-year follow-up of the Whickham Survey.

The original Whickham Survey documented the prevalence of diabetes and lipid disorders in a sample of 2779 adults aged 18 years and over, which matched the British population structure. The aim of the 20-year follow-up study was to determine the incidence and natural history of diabetes. Outcomes in terms of morbidity and mortality at follow-up were determined in over 97% of the original population. Ninety-four subjects had been identified and treated for diabetes since the first survey, including 17 subjects identified as having a fasting plasma glucose > or = 7.8 mmol l-1 at follow-up. The incidence of diabetes for the total population was 2.2 1000-1 year-1 (95% confidence interval 1.8, 2.6). The risk factors identified at first survey were corrected for age, cut-off at the 95 centile and entered into a log linear model. Those which strongly predicted development of diabetes in the total population were fasting blood glucose (odds ratio (OR) (with 95% confidence intervals) = 2.3 (1.5, 3.5)) and body mass index (OR = 2.2 (1.5, 3.3)) in men, and fasting blood glucose (OR = 2.6 (1.7, 4.1)) and fasting serum triglyceride (OR = 2.8 (1.8, 4.4)) in women. A logit model has enabled the calculation of the probability of developing diabetes 20 years later. It was the characteristics of becoming older such as obesity, hypertriglyceridaemia, and raised fasting blood glucose, rather than age itself, which were associated with the development of diabetes.

Adult↗
PubMed1996

The development of ischemic heart disease in relation to autoimmune thyroid disease in a 20-year follow-up study of an English community.

The original Whickham Survey documented risk factors for cardiovascular disease and the prevalence of thyroid disorders in a sample of 2779 adults that closely matched the British population. A 20-year follow-up study has determined outcomes in terms of morbidity and mortality from ischemic heart disease in over 97% of the original survey population. Analysis of deaths from all causes and from ischemic heart disease showed no association with antithyroid antibody status identified at first survey. A multiple logistic regression using the development of ischemic heart disease in the total population at follow-up as the dependent variable found that the significant predictor variables for men were age, cholesterol, mean arterial blood pressure, smoking history, and skinfold thickness index. For women only age, cholesterol, and mean arterial blood pressure were significant. The presence of autoimmune thyroid disease, as defined by either hypothyroidism, positive antithyroid antibodies, or raised serum thyrotropin at first survey, was not significant. A retrospective cohort study of a subsample of women identified at first survey with positive antithyroid antibodies or raised serum thyrotropin and closely matched controls found no significant association with mortality or development of ischemic heart disease. There is no evidence from this study to suggest that evidence of autoimmune thyroid disease identified 20 years ago is associated with an increased risk of ischemic heart disease.

Adolescent↗
PubMed1995

Parkinsonism in motor neuron disease: case report and literature review.

This report describes a patient who had clinical features of both motor neuron disease and Parkinson's disease. Neuropathological examination and immunocytochemical studies showed that he had motor neuron disease of the progressive muscular atrophy type, and Lewy body Parkinson's disease, with intracytoplasmic inclusion bodies characteristic of both conditions. This is the first detailed description of these two diseases occurring concurrently in the same patient. A review of all previously reported cases of combined motor neuron disease and parkinsonism has led to the following conclusions: (1) that these two neuropathologically defined diseases occur together very infrequently, but (2) that parkinsonism and substantia nigra degeneration are not uncommon as part of the multi-system disease process underlying motor neuron disease.

Aged↗
PubMed1995

The incidence of thyroid disorders in the community: a twenty-year follow-up of the Whickham Survey.

BACKGROUND AND OBJECTIVE: The original Whickham Survey documented the prevalence of thyroid disorders in a randomly selected sample of 2779 adults which matched the population of Great Britain in age, sex and social class. The aim of the twenty-year follow-up survey was to determine the incidence and natural history of thyroid disease in this cohort. DESIGN, PATIENTS AND MEASUREMENTS: Subjects were traced at follow-up via the Electoral Register, General Practice registers, Gateshead Family Health Services Authority register and Office of Population Censuses and Surveys. Eight hundred and twenty-five subjects (30% of the sample) had died and, in addition to death certificates, two-thirds had information from either hospital/General Practitioner notes or post-mortem reports to document morbidity prior to death. Of the 1877 known survivors, 96% participated in the follow-up study and 91% were tested for clinical, biochemical and immunological evidence of thyroid dysfunction. RESULTS: Outcomes in terms of morbidity and mortality were determined for over 97% of the original sample. The mean incidence (with 95% confidence intervals) of spontaneous hypothyroidism in women was 3.5/1000 survivors/year (2.8-4.5) rising to 4.1/1000 survivors/year (3.3-5.0) for all causes of hypothyroidism and in men was 0.6/1000 survivors/year (0.3-1.2). The mean incidence of hyperthyroidism in women was 0.8/1000 survivors/year (0.5-1.4) and was negligible in men. Similar incidence rates were calculated for the deceased subjects. An estimate of the probability of the development of hypothyroidism and hyperthyroidism at a particular time, i.e. the hazard rate, showed an increase with age in hypothyroidism but no age relation in hyperthyroidism. The frequency of goitre decreased with age with 10% of women and 2% of men having a goitre at follow-up, as compared to 23% and 5% in the same subjects respectively at the first survey. The presence of a goitre at either survey was not associated with any clinical or biochemical evidence of thyroid dysfunction. In women, an association was found between the development of a goitre and thyroid-antibody status at follow-up, but not initially. The risk of having developed hypothyroidism at follow-up was examined with respect to risk factors identified at first survey. The odds ratios (with 95% confidence intervals) of developing hypothyroidism with (a) raised serum TSH alone were 8 (3-20) for women and 44 (19-104) for men; (b) positive anti-thyroid antibodies alone were 8 (5-15) for women and 25 (10-63) for men; (c) both raised serum TSH and positive anti-thyroid antibodies were 38 (22-65) for women and 173 (81-370) for men. A logit model indicated that increasing values of serum TSH above 2mU/l at first survey increased the probability of developing hypothyroidism which was further increased in the presence of anti-thyroid antibodies. Neither a positive family history of any form of thyroid disease nor parity of women at first survey was associated with increased risk of developing hypothyroidism. Fasting cholesterol and triglyceride levels at first survey when corrected for age showed no association with the development of hypothyroidism in women. CONCLUSIONS: This historical cohort study has provided incidence data for thyroid disease over a twenty-year period for a representative cross-sectional sample of the population, and has allowed the determination of the importance of prognostic risk factors for thyroid disease identified twenty years earlier.

Adult↗