Personal Digital Assistants

Personal digital assistant sales are growing exponentially, and as medical technology advances the amount of information available becomes staggering, making a handheld device, with the ability to store a great amount of information, progressively more valuable to health care providers. Mobile computing allows for a great deal of knowledge in a small package, creating a walking library with a mobile collection of data always accessible. There are many diverse types of PDAs, and this article discusses the history of PDAs, general purchasing issues, general PDA features, and the most significant differences between the Palm and the Windows CE operating systems.     

Atrial natriuretic peptide expression is increased in rat cerebral cortex following spreading depression: possible contribution to sd-induced neuroprotection

Cortical spreading depression (CSD) is characterised by slowly propagating waves of cellular depolarization and depression and involves transient changes in blood flow, ion balance and metabolism. In cerebral ischaemia, peri-infarct CSD-like depolarization potentiates infarct growth, whereas preconditioning with a CSD episode protects against subsequent ischaemic insult. Thus, many of the long-lasting molecular changes that occur in CSD-affected tissue are presumed to be part of a 'neuroprotective cascade.' 3',5'-Cyclic guanosine monophosphate (cGMP) has been shown to be a neuroprotective mediator and the nitric oxide system, which increases cGMP production by soluble guanylate cyclase, is up-regulated by CSD. Atrial and C-type natriuretic peptide (ANP/CNP) are present in cerebral cortex and their actions are mediated via particulate guanylate cyclase receptors and cGMP production. Therefore, in further efforts to characterise the role of cGMP-related systems in CSD and neuroprotection, this study investigated possible changes in cortical natriuretic peptide expression following acute, unilateral CSD in rats. Using in situ hybridisation, significant 20-80% increases in ANP mRNA were detected in layers II and VI of ipsilateral cortex at 6 h and 1-14 days after CSD. Ipsilateral cortical levels were again equivalent to control contralateral values after 28 days. Assessment of cortical concentrations of ANP immunoreactivity by radioimmunoassay revealed a significant 57% increase at 7 days after CSD. Despite using a sensitive signal-amplification protocol, authentic ANP-like immunostaining was readily detected in subcortical nerve fibres, but was not reliably detected in normal or CSD-affected neocortex, suggesting the presence of very low levels, and/or active or differential processing of the peptide. Cortical CNP mRNA levels are not altered by CSD, indicating the specificity of the observed effects.Overall, these novel findings demonstrate a prolonged increase in cortical ANP expression after an acute episode of CSD. The overlap between the described time course of CSD-induced protection against ischaemic insult and demonstrated increases in ANP levels, suggest that ANP (like nitric oxide) may contribute to CSD-induced neuroprotection, via effects on cGMP production and other signal-transduction pathways.     

Phenotypic library-based microbial source tracking methods: efficacy in the California collaborative study

As part of a larger microbial source tracking (MST) study, several laboratories used library-based, phenotypic subtyping techniques to analyse fecal samples from known sources (human, sewage, cattle, dogs and gulls) and blinded water samples that were contaminated with the fecal sources. The methods used included antibiotic resistance analysis (ARA) of fecal streptococci, enterococci, fecal coliforms and E. coli; multiple antibiotic resistance (MAR) and Kirby-Bauer antibiotic susceptibility testing of E. coli; and carbon source utilization for fecal streptococci and E. coli. Libraries comprising phenotypic patterns of indicator bacteria isolated from known fecal sources were used to predict the sources of isolates from water samples that had been seeded with fecal material from the same sources as those used to create the libraries. The accuracy of fecal source identification in the water samples was assessed both with and without a cut-off termed the minimum detectable percentage (MDP). The libraries (approximately 300 isolates) were not large enough to avoid the artefact of source-independent grouping, but some important conclusions could still be drawn. Use of a MDP decreased the percentage of false-positive source identifications, and had little effect on the high percentage of true-positives in the most accurate libraries. In general, the methods were more prone to false-positive than to false-negative errors. The most accurate method, with a true-positive rate of 100% and a false-positive rate of 39% when analysed with a MDP, was ARA of fecal streptococci. The internal accuracy of the libraries did not correlate with the accuracy of source prediction in water samples, showing that one should not rely solely on parameters such as the average rate of correct classification of a library to indicate its predictive capabilities.     

Earring lesions of the parotid tail

BACKGROUND AND PURPOSE: Masses in the parotid tail can be a source of consternation to radiologists and clinicians; inaccurate localization may lead to significant iatrogenic complication. We sought to review the pertinent anatomic localizing features of the parotid tail, relevant facial nerve anatomy, and sources of clinical and radiologic confusion. To conclude, we review imaging features that are helpful in generating a diagnosis in this location. METHODS: We retrospectively reviewed the imaging and clinical features of 111 parotid tail masses in 103 patients (56 male, 45 female, two of unknown sex; age range, 5 months-81 years). The following imaging findings were noted: size, enhancement, multiplicity of lesions, attenuation on CT scans, signal intensity on MR images, and appearance of the surrounding parotid gland. Diagnosis was confirmed by either surgical resection or biopsy findings or by specific clinical data or characteristic imaging findings. RESULTS: Seventeen types of parotid tail masses were identified. Benign lesions were: pleomorphic adenoma (n = 15), Warthin tumor (n = 14), infectious process (n = 13), venous malformation (n = 9), and Sj?gren disease (n = 9), lymphatic malformations (n = 7), lipoma (n = 6), HIV lymphoepithelial lesion (n = 4), first brachial cleft cyst (n = 3), oncocytoma (n = 2), sarcoid (n = 1), and lymph node (n = 1). Malignant lesions were: Non-Hodgkin lymphoma (n = 14), metastatic disease (n = 7), mucoepidermoid carcinoma (n = 4), acinic cell carcinoma (n = 1), and undifferentiated carcinoma (n = 1). Eight patients had two diagnoses. CONCLUSION: Understanding normal parotid tail anatomy is important to radiologists, because accurate localization has implications for appropriate management of masses in this location, potentially reducing the occurrence of marginal mandibular nerve injury.     

Computerized Scientific Exhibit Utilization: Observations From infoRAD at the Radiologic Society of North America Scientific Assembly

No publication has discussed utilization of computer scientific exhibits (CSE) at national symposia, despite their growing numbers. The hypothesis of this project was that, when given a choice, viewers initially would prefer a more conventional paper presentation of a scientific exhibit over that of an electronic presentation. A nearly identical paper version of the introductory screen to an infoRAD CSE was placed adjacent to the workstation. Utilization of the paper introduction, computer introduction, and both, as well as subsequent behavior, was recorded. Of 67 visitors, initial user choice was 56.7% paper and 43.3% computer. Over the entire time at the exhibit 25.4% only looked at the handout, 25.4% only at the computer, and 49.3% perused both. Only 10.5% completed the entire exhibit, and 0.94% of total registrants visited the CSE. Overall, 74.7% perused the CSE when leaving the exhibit area. Upon arrival, viewers preferred the more conventional paper presentation, confirming the project hypothesis. Surprisingly, about 75% eventually perused at least a portion of the computer presentation. Although a small fraction of Radiologic Society of North America (RSNA) registrants visited the CSE, the findings presented are promising and suggest that CSE presence at national meetings is justifiable, providing a "first step" toward CME outcomes analysis of CSE. Overall, these findings are promising and suggest that computer scientific exhibit presence at national meetings is justifiable.     

Pulmonary cystic hydatid disease in Ireland

Background Hydatid disease is rare in Ireland and its incidence and prevalence are unknown. Most cases are diagnosed by a combination of clinical findings, morphological features on imaging and by serological testing. Aims We describe an Irish case of pulmonary hydatid disease detected at bronchoscopy by bronchoalveolar lavage, and discuss the diagnosis and treatment of the disorder.     

Agromedicine focus group: cooperative extension agents and medical school instructors plan farm field trips for medical students

BACKGROUND: Current medical education policy seeks to address the health care needs of underserved populations, among whom are individuals associated with agriculture. METHODS: This paper describes a focus group approach to planning farm field trips whereby medical students accompany agricultural extension agents to study the personal, occupational, and environmental health concerns of farmers. RESULTS: The resulting plan joins a state's cooperative extension system, medical school, and farm community in partnership to provide an experiential approach to agricultural medicine and rural health education. CONCLUSION: The planning exercise and the field trips are successful examples of agromedicine, a partnership approach to preventive agricultural medicine involving professionals in medicine and in agriculture.     

Absorption and endogenous faecal excretion of calcium by low birthweight infants on feeds with varying contents of calcium and phosphate

Low birthweight infants aged 4-41 days were given from birth one of three experimental milk formulae varying widely in content of calcium and phosphate. Ca and P in feed, urine, and faeces were measured between carmine markers corresponding to a metabolic period of 48 hours. Calcium enriched in 46Ca to provide a marker for the dietary Ca was added to one feed and 46Ca measured in urine and faeces. True absorption of Ca and endogenous excretion into the bowel could then be inferred. True absorption of Ca was proportional to Ca intake and independent of P intake. Endogenous faecal excretion seemed to be independent of both Ca P intakes, and varied widely between different infants in the range 4-150 mg/day. Urine Ca was low and retention was essentially the difference between true absorption and endogenous faecal excretion. Retention of Ca tended to be much greater on a high Ca intake, but the variability in retention between infants on a given intake was large, paralleling the variability in endogenous faecal excretion. The variability in plasma Ca concentrations in newborn infants may in part be a consequence of wide individual variability in endogenous faecal excretion. The 46Ca marker technique provides a means of investigating the factors determining this variability.