Search PubMed⌕ Search

Biomedical subjects

R Brooks

Publications and source records attributed to R Brooks.

At least 109 records · Page 6Linked to original sources
PubMed1988

A baiting system suitable for the delivery of oral rabies vaccine to dog populations in Zimbabwe.

A baiting system suitable for the delivery of oral rabies vaccine to dog populations in developing countries was studied in Zimbabwe. In a field trial, 369 sponge baits containing a placebo liquid, rhodamine B as a biomarker and a pungent attractant were distributed over an area of 60 sq km in a communal land in Manicaland with a dog population of over 500. Twenty-four hours later 21 per cent of the baits were recovered and 79 per cent of these had been significantly bitten or chewed. Twenty-five per cent of the dogs examined showed evidence of superficial staining by rhodamine B indicating that they had chewed baits or ingested their contents. It was concluded that the system would deliver an oral vaccine to dog populations more efficiently than had been the case in comparable studies in wildlife populations, but that the number of baits per unit area should in future studies be increased.

Administration, Oral↗
PubMed1988

Comparison of a protein-stabilized Rotazyme II test, with standard Rotazyme II, and electron microscopy for detection of rotavirus.

We compared the performance of Rotazyme II with protein-stabilized diluent to standard Rotazyme II and to direct electron microscopy, for the detection of rotavirus. Sensitivity and specificity were: standard Rotazyme II, 79 and 100%, respectively; Rotazyme II with protein stabilizers, both 100%, and electron microscopy, 75 and 100%, respectively. Commercial availability of this product should improve rotavirus detection for laboratories utilizing Rotazyme II methodology.

Child↗
PubMed1988

Small cell carcinoma of urinary bladder.

A fifty-seven-year-old woman with urinary bladder carcinoma with extensive areas resembling oat cell carcinoma of the lung in whom distant metastases developed, died seven months after diagnosis. Argyrophil cells could not be demonstrated, but electron microscopy demonstrated dense-core, membrane-bound intracytoplasmic granules. We reviewed 12 cases of epithelial neoplasms of the bladder from the literature in which there was ultrastructural evidence of neuroendocrine differentiation. Cases with malignant histologic features, like their pulmonary counterparts, have the potential for widespread dissemination and rapid growth. We support the previous suggestion that these neoplasms may be of considerable incidence and their recognition is important to determine prognosis and selection of therapy.

Carcinoma, Small Cell↗
PubMed1988

Idiopathic ventricular tachycardia. A review.

Idiopathic or unexplained VT occurs in a small but important subset of patients without clinically evident heart disease. The majority of these patients appear to have a structurally normal heart. The cause of the arrhythmias in these individuals is unclear and may never be recognized. Other patients with this condition may have minor abnormalities not sufficient to impair overall cardiac function. The significance of these abnormalities to the genesis of the arrhythmia is uncertain. Whether patients with minor abnormalities are more likely to harbor covert heart disease such as myocarditis or a focal defect is not known, nor is it resolved whether such patients warrant a more aggressive search for a structural cause. The question that remains in any patient not subjected to surgical or pathological exploration is whether undetermined heart disease is responsible for the arrhythmia. Continued correlation between functional (electrophysiological) and structural (pathological) data will provide meaningful information concerning the pathophysiology (substrate) of these arrhythmias. Because of the preservation of normal cardiac function, these arrhythmias are generally well-tolerated. Although the condition is usually associated with a favorable prognosis, the occasional deaths reported in patients with apparently idiopathic ventricular arrhythmias may not permit calling this condition benign. It would be important to know the extent to which unrecognized abnormalities play a role in the genesis of these tachycardias, and whether such patients are more predisposed to fatal arrhythmias or have a different natural history. If cases involving undetermined or covert heart disease were excluded from consideration, then a relatively homogeneous disease-free group may be identified with a truly benign condition and a uniformly favorable prognosis. In these cases, a primary electrical abnormality may prove to be the basis for the arrhythmia. These issues remain to be elucidated in future studies.

Cardiomyopathies↗
PubMed1988

Association between immediate termination of supraventricular tachycardia by carotid sinus pressure and carotid sinus hypersensitivity.

An association between rapid reversion of supraventricular tachycardia by carotid sinus stimulation and carotid sinus reflex hypersensitivity during sinus rhythm is described in a 55-year-old patient. The findings indicate that a high level of vagal tone facilitates vagal maneuvers in terminating some supraventricular tachyarrhythmias. The briskness of the response during tachycardia may also be a marker for underlying carotid sinus hypersensitivity.

Carotid Sinus↗
PubMed1987

Bony ankylosis in rheumatoid arthritis. Associations with longer duration and greater severity of disease.

Hand and wrist radiographs of 203 patients with rheumatoid arthritis were examined for bony ankylosis. Forty-eight patients (23.6%) showed ankylosis, including 34 with more than one joint fused. The distribution of ankylosed joints was 32.4% midcarpal, 29.5% common carpometacarpal, 15.8% radiocarpal, 15.8% proximal interphalangeal, and 6.5% metacarpophalangeal. Patients with ankylosis had significantly higher radiographic erosion, joint space narrowing, and malalignment scores than those without ankylosis (all P less than .001). Patients with ankylosis had significantly longer duration of disease (P less than .001) and physical examinations showed more limited motion and deformity (both P less than .001). More patients with ankylosis had subcutaneous nodules (P less than .05). Functional testing with grip strength and the button test revealed poorer performance in patients with ankylosis (both P less than .001). Questionnaires revealed patients with ankylosis had more difficulty with activities of daily living (P less than .001) and had more limited activity (P less than .01); physicians estimated more limited functional capacity (P less than .001). Thus, radiographic bony ankylosis was a relatively common feature of rheumatoid arthritis, and a marker of patients whose disease was clinically, radiographically, and functionally more severe.

Age Factors↗
PubMed1985

Management of acute and chronic disorders of the trachea and subglottis.

During a 14 year period, 22 patients with stricture, acute laryngeal injury, and cancer were treated. Nine patients had postintubation tracheal stenosis and underwent tracheal resection with good to excellent results. Six patients had strictures after tracheostomy. In one patient, stenosis occurred after repair and repeated dilatation was necessary. He subsequently had to undergo repeat tracheostomy, but the tube was later removed and his symptoms disappeared. Our current preference for suture is either 3-0 polypropylene or polyglycolic acid. Acute separation of the trachea can occur with trauma to the neck, either by garrotting or direct blunt force. The diagnosis is suspected when endotracheal intubation is impossible and a step off below the larynx and crepitation exists. Emergency tracheostomy is necessary, however, and primary repair can be delayed for up to 24 hours if other conditions require attention. Tracheal resection for squamous cell carcinoma is possible, but only a small group of patients may be surgical candidates.

Adolescent↗
PubMed1985

Eccrine gland clear reticulated cytoplasm.

This report relates how a normal variation of the eccrine secretory coil was mistaken for pathologic change. Electron microscopic studies of this variation, which to the best of our knowledge have not previously been reported, are presented.

Adult↗
PubMed1985

Peripheral T-cell lymphoma: aggressive disease with heterogeneous immunotypes.

Eleven patients with mature or peripheral T-cell lymphoma (PTL), other than mycosis fungoides, were identified using an extensive battery of T- and B-cell markers. Eight cases had a histologic diagnosis of either diffuse large cell or mixed lymphoma, three of small cell type. All cases had one or more "mature" T-antigens and an absence of B- and immature T-antigens. Assessment of T-antigens included E-rosettes (Er), anti-Leu 1-7 and Tdt. The authors delineated striking heterogeneity of T-antigen expression: 9 different immunotypes in 11 cases. Subset T-antigen assessment indicated T-helper neoplastic cells in five cases and T-suppressor in two. The remaining four had universal T-antigens alone. Seven cases appeared to have "novel" T-phenotypes not corresponding to normal T-ontogeny phenotypes. Novel or idiosyncratic phenotypes may be a key characteristic of PTL. Since no single T-antigen, including Er and Er receptor (Leu-5), was expressed in all cases, a battery of monoclonal antibodies is necessary to detect PTL. Clinically, the authors found PTL unexpectedly aggressive, despite mature immunotype. Most patients were elderly (median age 69); all had extranodal disease with cutaneous involvement (six cases) most frequent. Responses to chemotherapy frequently proved transient, with median survival of nine months. A fulminant course was noted even with localized presentation. Clinical outcome suggests PTL requires new therapeutic strategies.

Adult↗
PubMed1985

Positron emission tomography in generalized seizures.

We used 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) to study nine patients with clinical absence or generalized seizures. One patient had only absence seizures, two had only generalized tonic-clonic seizures, and six had both seizure types. Interictal scans in eight failed to reveal focal or lateralized hypometabolism. No apparent abnormalities were noted. Two patients had PET scans after isotope injection during hyperventilation-induced generalized spike-wave discharges. Diffusely increased metabolic rates were found in one compared with an interictal scan, and in another compared with control values. Another patient had FDG injected during absence status: EEG showed generalized spike-wave discharges (during which she was unresponsive) intermixed with slow activity accompanied by confusion. Metabolic rates were decreased, compared with the interictal scan, throughout both cortical and subcortical structures. Interictal PET did not detect specific anatomic regions responsible for absence seizure onset in any patient, but the results of the ictal scans did suggest that pathophysiologic differences exist between absence status and single absence attacks.

Adult↗
PubMed1984

Wechsler Adult Intelligence Scale performance. Cortical localization by fluorodeoxyglucose F 18-positron emission tomography.

We compared local cerebral glucose metabolism, as determined by positron emission tomography following administration of fluorodeoxyglucose F 18, with Wechsler Adult Intelligence Scale (WAIS) scores in 22 right-handed persons. Five study subjects were normal volunteers and the remainder had Alzheimer's disease. Subtest scores within the verbal IQ group or the performance IQ group were generally highly interrelated; there was usually no correlation between the verbal and performance subtests. The cortical distribution of regions in which glucose metabolism was most closely associated with verbal subtest scores generally centered in the left parasylvian area. In contrast, scores on the performance subtests mainly localized to the right posterior parietal region. Most WAIS subtests thus appeared to evaluate primarily either verbal or visuospatial cognitive functions and either left parasylvian or right posteroparietal cortical activity.

Aged↗
PubMed1984

Regional cortical dysfunction in Alzheimer's disease as determined by positron emission tomography.

Local cerebral glucose metabolism and psychometric function were compared in 17 patients with Alzheimer's disease and 5 healthy age-matched controls. Performance on tests of global intellectual function averaged 30 to 45% lower in the Alzheimer's group. Mean cortical glucose metabolism, as determined by positron emission tomography following fluorine-18-labeled fluorodeoxyglucose administration, was reduced by 30% in the Alzheimer's group. There was a significant positive correlation between the degree of overall dementia and the amount of metabolic reduction. The distribution of cortical hypometabolism was not uniform: the posterior parietal lobes and contiguous portions of the posterior temporal and anterior occipital lobes were most severely involved. The frontal cortex was relatively spared. These findings are compatible with the major clinical deficits found in patients with Alzheimer's disease and may help focus future biochemical probes into the pathophysiology of this disease.

Alzheimer Disease↗
PubMed1984

The role of positron emission tomography in the evaluation of seizure disorders.

We studied patients with partial and primary generalized seizures using fluorine-18-labeled 2-fluorodeoxyglucose and positron emission tomography. Interictal studies of patients with partial seizures showed regions of focal or lateralized hypometabolism in 15 of 17 patients with unilateral electroencephalographic foci. Several patients had more than one hypometabolic region. In 1 patient PET hypometabolism was contralateral to the electroencephalographic epileptic focus. Six of 10 patients without definite electroencephalographic foci also showed unilateral PET hypometabolic regions. PET during complex partial seizures in 3 patients showed hypermetabolism at the site of the hypometabolic focus. A postictal scan in 1 patient showed extension of interictal temporal hypometabolism to the frontal lobe as well. Interictal scans in 8 patients with primary generalized seizures did not reveal any hypometabolic regions. One patient scanned during an attack of absence status epilepticus showed a slight decrease in metabolic rate compared to the interictal scan. Temporal lobectomy has been performed in 6 patients with focal PET hypometabolism. PET may obviate the need for depth electrode study in some patients with intractable partial seizures.

Electroencephalography↗