The epidemiology of infectious diseases among South American Indians: a call for guidelines for ethical research.
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Communicable Diseases↗
Biomedical subjects
J Lancaster
Publications and source records attributed to J Lancaster.
Neuroimaging evidence implicating cerebellum in support of sensory/cognitive processes associated with thirst.
Recent studies implicate the cerebellum, long considered strictly a motor control structure, in cognitive, sensory, and affective phenomenon. The cerebellum, a phylogenetically ancient structure, has reciprocal ancient connections to the hypothalamus, a structure important in vegetative functions. The present study investigated whether the cerebellum was involved in vegetative functions and the primal emotions engendered by them. Using positron emission tomography, we examined the effects on the cerebellum of the rise of plasma sodium concentration and the emergence of thirst in 10 healthy adults. The correlation of regional cerebral blood flow with subjects' ratings of thirst showed major activation in the vermal central lobule. During the development of thirst, the anterior and posterior quadrangular lobule, lingula, and the vermis were activated. At maximum thirst and then during irrigation of the mouth with water to alleviate dryness, the cerebellum was less activated. However, 3 min after drinking to satiation, the anterior quadrangular lobule and posterior cerebellum were highly activated. The increased cerebellar activity was not related to motor behavior as this did not occur. Instead, responses in ancient cerebellar regions (vermis, fastigal nucleus, archicerebellum) may be more directly related to vegetative and affective aspects of thirst experiences, whereas activity in neocerebellar (posterior) regions may be related to sensory and cognitive aspects. Moreover, the cerebellum is apparently not involved in the computation of thirst per se but rather is activated during changes in thirst/satiation state when the brain is "vigilant" and is monitoring its sensory systems. Some neocerebellar activity may also reflect an intentionality for gratification by drinking inherent in the consciousness of thirst.
Adult↗
Intersubject variability in cortical activations during a complex language task.
Intersubject variability in the functional organization of the human brain has theoretical and practical importance for basic and clinical neuroscience. In the present study, positron emission tomography (PET) and anatomical magnetic resonance imaging (MRI) were used to study the functional anatomy of language processes. Intersubject variability in task-induced activations in six brain regions was assessed in 20 normal subjects (10 men and 10 women) for frequency of occurrence, location, intensity, and extent. A complex, but well-studied task (overt verb generation) was compared to a simple baseline (visual fixation) to induce activations in brain areas serving perceptual, motoric, and cognitive functions. The frequency of occurrence was high for all selected brain areas (80-95%). The variability in response location in Talairach space, expressed as the standard deviation along each axis (x, y, z), ranged from 5.2 to 9.9 mm. This variability appears to be uniformly distributed across the brain, uninfluenced by regional differences in the complexity of gyral anatomy or mediated behavior. The variability in response location, expressed as the average Euclidean distances (averaged across subjects) about mean locations of activations, varied from 9.40 to 13.36 mm and had no significant differences by region (P>0.05, beta = 0.20). Intensity variability was also relatively small and homogenous across brain regions. In contrast, response extent was much more variable both across subjects and across brain regions (0.79 to 1.77, coefficient of variation). These findings are in good agreement with previous PET studies of intersubject variability and bode well for the possibility of using functional neuroimaging to study neural plasticity subsequent to congenital and acquired brain lesions.
Adult↗
Magnetic nasal foreign bodies.
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Foreign Bodies↗
Non-pseudomonal malignant otitis externa and jugular foramen syndrome secondary to cyclosporin-induced hypertrichosis in a diabetic renal transplant patient.
We present the case of a 58-year-old diabetic renal transplant patient who developed a left jugular foramen syndrome, secondary to an ipsilateral staphylococcal malignant (necrotizing) otitis externa. This followed a protracted episode of uncomplicated otitis externa with no evidence of bone involvement on computed tomography (CT) scanning. Cyclosporin-induced hypertrichosis (excess hair growth) in his external auditory canal contributed greatly to the initial difficulty in managing his otitis externa. Following an initial successful treatment with prolonged intravenous antibiotics the patient relapsed with a secondary infection in the same anatomical site due to Candida parapsilosis. Despite further intensive treatment including antimicrobials, a subtotal petrosectomy and hyperbaric oxygen therapy he eventually succumbed to his disease.
Candidiasis↗
Rare case of naso-oral fistula with extensive osteocartilaginous necrosis secondary to cocaine abuse: review of otorhinolaryngological presentations in cocaine addicts.
We report what we believe to be only the 10th case of palatal necrosis secondary to cocaine abuse in a 33-year-old female patient. Extensive necrosis also involved the cartilaginous and bony septum and paranasal sinuses. Following exclusion of other mid-line destructive diseases her treatment involved saline douches and cessation of cocaine. She remains under review within the department with no evidence of progressive disease. We present a review of the other nine cases of palatal necrosis reported in the world literature and demonstrate a greater incidence in female users. The various presenting conditions of cocaine abuse encountered within the head and neck region by the otorhinolaryngologist are then discussed.
Adult↗
Evaluation of octree regional spatial normalization method for regional anatomical matching.
The goal of regional spatial normalization is to remove anatomical differences between individual three-dimensional (3D) brain images by warping them to match features of a standard brain atlas. Processing to fit features at the limiting resolution of a 3D MR image volume is computationally intensive, limiting the broad use of full-resolution regional spatial normalization. In Kochunov et al. (1999: Neuro-Image 10:724-737), we proposed a regional spatial normalization algorithm called octree spatial normalization (OSN) that reduces processing time to minutes while targeting the accuracy of previous methods. In the current study, modifications of the OSN algorithm for use in human brain images are described and tested. An automated brain tissue segmentation procedure was adopted to create anatomical templates to drive feature matching in white matter, gray matter, and cerebral-spinal fluid. Three similarity measurement functions (fast-cross correlation (CC), sum-square error, and centroid) were evaluated in a group of six subjects. A combination of fast-CC and centroid was found to provide the best feature matching and speed. Multiple iterations and multiple applications of the OSN algorithm were evaluated to improve fit quality. Two applications of the OSN algorithm with two iterations per application were found to significantly reduce volumetric mismatch (up to six times for lateral ventricle) while keeping processing time under 30 min. The refined version of OSN was tested with anatomical landmarks from several major sulci in a group of nine subjects. Anatomical variability was appreciably reduced for every sulcus investigated, and mean sulcal tracings accurately followed sulcal tracings in the target brain.
Algorithms↗
Neuroimaging of genesis and satiation of thirst and an interoceptor-driven theory of origins of primary consciousness.
There are defined hypothalamic functions in the genesis of thirst, but little is known of the cortical processes subserving consciousness of thirst notwithstanding the medical disorders that occur in psychiatric illness, addiction, and the attested decline of thirst with aging. In 10 adult males, positron emission tomography scans were made (i) during genesis of moderate thirst by infusion of i.v. hypertonic saline 0.51 M, (ii) after irrigation of the mouth with water to remove the sensation of dryness, and (iii) 3, 14, 45, and 60 minutes after drinking water to fully satiate thirst. The correlation of regional cerebral blood flow with thirst score showed the major activation to be in the posterior cingulate. Maximum thirst sensation evoked 13 highly significant activations and 9 deactivations in cingulate and parahippocampal gyri, insula, thalamus, amygdala, and mesencephalon. It is possible that cingulate sites (Brodmann's areas 32, 24, and 31) that persisted with wet mouth but disappeared immediately after drinking to satiation may have an important role in the consciousness of thirst. Consciousness of thirst, a primal vegetative emotion, and satiation of thirst appear to be subserved by phylogenetically ancient brain regions. This is salient to current discussion on evolutionary emergence of primary consciousness.
Adult↗
Correlation of anthropometry with CT in Mexican-American women.
Measurement of regional fat has commonly been accomplished by extrapolation from anthropometric measures. Recent studies of White and Black women have demonstrated differences in intra-abdominal fat, using computerized tomographic (CT) techniques. These same estimates were computed for 48 Mexican American women who were undergoing CT for diagnostic purposes. Waist-hip ratios, waist-thigh ratios, and sagittal diameter index were also calculated. Four (7mm) CT slices between L-4 and L - 5 were analyzed with imaging software. The volume of both subcutaneous and visceral fat was estimated. Like other minority women, Mexican American women had less intra-abdominal fat than subcutaneous fat, which is important because of the association of excess intra-abdominal fat with cardiovascular risk. Intra-abdominal fat volume was significantly predicted by only one variable, sagittal abdominal diameter, while subcutaneous fat volume was predicted by hip and thigh circumferences.
Adipose Tissue↗
Medical containers and the law.
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Australia↗
Mycobacterium bovis as a zoonosis in the Kruger National Park, South Africa.
SETTING: The Kruger National Park (KNP), Mpumalanga Province, South Africa. OBJECTIVE: The prevalence of tuberculosis caused by Mycobacterium bovis exceeds 70% in African buffalo in the southern region of the KNP. Inter-species transmission (lion, cheetah, baboon, antelope) has also been confirmed. Regular culling of emaciated buffalo and processing of meat and hides constitute routine control policy. Following extensive media coverage of the problem, public health concerns about the transmission of M. bovis to humans, including visitors to the KNP, prompted this investigation. DESIGN: The study was designed to determine the prevalence of infection and/or active disease due to M. bovis among KNP employees selected from three defined risk groups based on occupation category. RESULTS: Of 206 persons screened for active disease by sputum bacteriology, two persons with disease due to M. tuberculosis were identified. No isolate of M. bovis was found. Differential skin testing using three antigens failed to show any degree of M. bovis infection risk, even among high risk occupations. Reasons for these results are discussed. CONCLUSIONS: Bovine tuberculosis was not indicated as an occupational zoonosis in the KNP, nor was aerosol transmission implicated as a mechanism for human infection. Concerns about the public health implications of tuberculosis in buffalo in the KNP have therefore not been validated.
Adult↗
Identification of two distinct deleted regions on chromosome 13 in prostate cancer.
Aberrations of 13q occur frequently in prostate cancer and this chromosome contains two known tumor suppressor genes, BRCA2 and Rb1. This study analysed 13q LOH, DNA ploidy, BRCA2 mutation and pRb expression in prostate cancers. In total, 13q deletions were found in 18 of 36 tumors but did not correlate with histological grade, stage or DNA ploidy. Two smallest regions of overlapping deletions were defined: one flanked by D13S218 and D13S153; the other flanked by D13S31 and D13S137. BRCA2 was less frequently deleted whereas Rb1 did have a high frequency of deletion. None of the two genes was located in any of these two regions. Furthermore, BRCA2 mutation was not found in the five tumors where deletions had involved the BRCA2 locus. Neither did the Rb1 deletion correlate with absent pRb expression. In addition, tetraploidy was found in 14 out of 25 tumors analysed and correlated with aberrant pRb expression. Our results indicate that 13q deletion is an early non-random event. Tumor suppressor genes other than BRCA2 or Rb1 may be the target of 13q deletions. Aberrant pRb expression may not reflect the two-hit Rb1 inactivation but may be involved in the tetraploidization of prostate cancer cells.
Aged↗
A phase I trial of human corticotropin-releasing factor (hCRF) in patients with peritumoral brain edema.
BACKGROUND: Human corticotropin-releasing factor (hCRF) is an endogenous peptide responsible for the secretion and synthesis of corticosteroids. In animal models of peritumoral brain edema, hCRF has significant anti-edematous action. This effect, which appears to be independent of the release of adrenal steroids, appears mediated by a direct effect on endothelial cells. We conducted a feasibility and phase I study with hCRF given by continuous infusion to patients with brain metastasis. PATIENTS AND METHODS: Peritumoral brain edema documented by MRI and the use of either no steroids or stable steroid doses for more than a week were required. MRIs were repeated at completion of infusion and estimations by dual echo-image sequence (Proton density and T2-weighted images) of the amount of peritumoral edema were performed. The study was performed in two stages. In the feasibility part, patients were randomized to receive either 0.66 or 1 microgram/kg/h of hCRF or placebo over 24 hours. The second part was a dose finding study of hCRF over 72 hours at escalating doses. RESULTS: Seventeen patients were enrolled; only one was receiving steroids (stable doses) at study entrance; dose-limiting toxicity (hypotension) was observed at 4 micrograms/kg/h x 72 hours in two out of four patients, while zero of five patients treated at 2 micrograms/kg/h developed dose-limiting toxicities. Flushing and hot flashes were also observed. Improvement of neurological symptoms and/or exam were seen in 10 patients. Only small changes were detected by MRI. Improvement in symptoms did not correlate with changes in cortisol levels, and changes in cortisol levels were not correlated with changes in peritumoral edema. CONCLUSIONS: hCRF is well tolerated in doses up to 2 micrograms/kg/h by continuous infusion x 72 hours. Hypotension limits administration of higher doses. The observation of clinical benefit in the absence of corticosteroids suggests hCRF may be an alternative to steroids for the treatment of patients with peritumoral brain edema. Further exploration of this agent in efficacy studies is warranted.
Adrenal Glands↗
NHS library and information services in Wales.
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Cooperative Behavior↗
Non-attendance. A turn up for the books.
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Advertising↗
Acute and chronic effects of a 5-lipoxygenase inhibitor in asthma: a 6-month randomized multicenter trial. Zileuton Study Group.
BACKGROUND: Leukotrienes produced by the 5-lipoxygenase pathway of arachidonic acid metabolism may mediate bronchoconstriction and inflammatory changes important in the pathophysiology of asthma. Leukotriene inhibition may be effective in asthma management. OBJECTIVE: This clinical trial was performed to assess the long-term efficacy and safety of zileuton, an inhibitor of 5-lipoxygenase. METHODS: In this multicenter, double-blind, parallel-group, placebo-controlled trial, 600 mg of zileuton, 400 mg of zileuton, or placebo was given orally, each four times daily for 6 months. Patients with mild to moderate asthma (n = 373), 18 to 62 years of age, being managed with regularly inhaled beta-agonist alone, were randomized to the zileuton or placebo groups (n = 122 to 126). Outcome measures included serial spirometry, daily peak expiratory flow rates, daytime and nocturnal symptoms, frequency of beta-agonist use, and number of asthma exacerbations treated with systemic corticosteroids. RESULTS: An acute bronchodilatory effect was observed 2 to 5 hours after the initial dose of medication in both 400 mg zileuton and 600 mg zileuton groups compared to the placebo group. Both zileuton groups had significantly greater improvements in FEV1 than did the placebo group by day 8. On day 36, FEV1 improved 16% and 12% from baseline for patients treated with 600 mg zileuton and 400 mg zileuton, respectively, compared with an improvement of 6% for the placebo-treated group (p < 0.01, zileuton 600 mg vs placebo). Blood eosinophil levels were significantly reduced in both zileuton-treated groups compared with the placebo group. In the group receiving 600 mg zileuton, morning peak expiratory flow rate improved by 7% to 10%; daytime and nocturnal symptoms decreased by 37% and 31%, respectively; beta-agonist use decreased by 31%; and the proportion of patients requiring steroid rescue medication during the study was reduced by 62% (p < 0.05 for all comparisons of zileuton, 600 mg, vs placebo). Improvements were sustained over 6 months. Adverse events were similar in the three groups with no apparent, dose-related side effects. CONCLUSION: Zileuton produces objective and subjective improvements in patients with mild to moderate asthma and is well tolerated.
Adolescent↗
Group peer review: a questionnaire-based survey.
OBJECTIVE: This paper presents the findings from a questionnaire-based survey of psychiatrists designed to elucidate the positive and negative aspects of group peer review and its perceived place in accountability procedures, and to provide information about how accountability through group peer review might be improved. METHOD: Three hundred and eighty-eight psychiatrists were surveyed via mailout questionnaire. Demographic data, details of groups, and perceptions of beneficial and detrimental effects of group peer review were sought from group participants and non-participants. Attitudes of participants were compared with those of non-participants. Features of groups related to satisfaction in participants were examined. RESULTS: The majority of the 170 respondents participating in groups regarded peer review as a means of maintaining and improving skills, sharing ideas and methods, receiving constructive criticism and feedback, of educational benefit and an important source of professional accountability. Non-participants, while less positive overall, responded equally that participation in peer review groups would be an effective response to accountability procedures. Potential detrimental effects and problems with the functioning of peer review groups were elucidated. CONCLUSIONS: Group peer review contributes significantly to professional accountability and education in well-functioning groups. Further strategies for the facilitation of group functioning and for the processing of problems arising in group peer review need to be developed to optimise its contribution to the maintenance and improvement of professional standards.
Adolescent Psychiatry↗
Group peer review in psychiatry: the relationship to quality improvement and quality care.
OBJECTIVE: This study sought to elucidate the contribution of peer review groups involving psychiatrists to quality improvement and quality care. METHOD: Audio-taped interviews of groups engaged in peer review were analysed using a qualitative methodology. Participants' views of the ways in which they experienced and conceptualised peer review were explored. RESULTS: The views of participants in peer review groups were analysed, and categories evolved which identified differences in how they perceived the structure and function of group peer review. CONCLUSIONS: Participants in the groups studied perceived peer review as a professional growth forum within a quality improvement framework providing critical review of treatment, continuing education, and a sense of collegiality. Boundaries of acceptable practice were tested and defined. At its best, participation in peer review groups enhanced reflective practice which achieved new understandings of clinical work. In this regard, peer review is seen as a highly desirable method for the maintenance of professional standards.
Attitude of Health Personnel↗