Clinical evaluation of technetium-99m infecton for the localisation of bacterial infection

The aim of the study was to distinguish infection from inflammation in patients with suspected infection using technetium-99m Infecton. Ninety-nine patients (102 studies) referred for infection evaluation underwent imaging with 400 MBq^99mTc-Infecton at 1 and 4 h. Most patients had appropriate microbiological tests and about half (56) had radiolabelled white cell scans as well. No adverse effects were noted in any patient. The clinical efficacy of^99mTc-Infecton depended in part on whether imaging was undertaken during intibiotic therapy for infection or not. In consultation with the microbiologist, 5–14 days of appropriate and successful antibiotic therapy was considered adequate to classify some results as true-negatives. The figures for sensitivity and specificity of^99mTc-Infecton for active or unsuccessfully treated infection were 83% and 91% respectively. It is concluded that^99mTc-Infecton imaging contributed to the differential diagnosis of inflammation. It is being used as the first imaging modality when bacterial infection is suspected.     

High-dose gadoteridol in MR imaging of intracranial neoplasms.

Twelve patients with a high suspicion of brain metastases by previous clinical or radiologic examinations were studied in a phase III investigation with magnetic resonance (MR) imaging at 1.5 T after a bolus intravenous injection of 0.1 mmol/kg gadoteridol followed at 30 minutes by a second bolus injection of 0.2 mmol/kg gadoteridol. All lesions were best demonstrated (showed greatest enhancement) at the 0.3-mmol/kg (cumulative) dose, with image analysis confirming signal intensity enhancement in the majority of cases after the second gadoteridol injection. More lesions were detected with the 0.3-mmol/kg dose than with the 0.1-mmol/kg dose, and more lesions were detected with the 0.1-mmol/kg dose than on precontrast images. In this limited clinical trial, high-dose gadoteridol injection (0.3-mmol/kg cumulative dose) provided improved lesion detection on MR images specifically in intracranial metastatic disease.     

Internet tools in the medical classroom

Summary: The Internet contains a vast amount of medically relevant information. In order to access this information, however, many networks require one to master applications written in UNIX, an operating system considered by many not to be user friendly. Although these tools may be available on the campus, it is difficult to teach their use unless there is some immediate benefit to the already busy user. From that standpoint, it is important for instructors to realize that common UNIX applications can be utilized as classroom tools to significantly enhance the learning experience by facilitating teacher/student communication. Also, whilst the student enjoys greater communication with the instructor (and with other students) he/she is also becoming adept at using information management tools.     

Effect of different questionnaire formats on reporting of occupational exposures

During an exposure monitoring study, 78 saw maintenance tradesmen were randomly assigned to be interviewed about their exposures using one of two questionnaire formats: open-ended and partly prompted questions about five categories of materials; and detailed prompting about 75 agents. The more open-ended questionnaire elicited fewer exposure responses overall, but more responses about agents not included on the detailed questionnaire. Composite materials and trade name products were more frequently cited as exposures than individual metals or compounds. Validity of responses was ascertained using air measurements (individual metals) or observations of the employees (composite materials). Sums of sensitivities and specificities were very low (near 1.0) for most of the metals for both types of questionnaire. For composite materials, validity improved substantially. Sensitivities with the partly prompted format (0.44–0.85) were always lower than with detailed prompting (0.80–1.00). Specificities were usually, but not always, higher with partial prompting (0.66–0.92) than with detailed prompting (0.18–0.86). Selection of questionnaire format for an epidemiologic study would depend on the likely prevalence of exposure in controls and the effects of trade-offs in sensitivity and specificity.     

Effects of cadaver dissection on the attitudes of medical students

Summary: Summary. A study was conducted to determine whether the attitudes of medical students to death and caring changed during the 3 months following exposure to cadaver dissection. All first-year students were invited to complete a questionnaire immediately before their initial cadaver dissection experience, after 6 weeks, and after a further 3 months. The questionnaire reflected attitudes to death, violent death, death of someone known to the respondent and caring when someone known to the respondent is seriously injured. Ethnicity and previous exposure to dying has no effect on responses, but overall men students' reactions were significantly less than for women ( P < 0.001). The responses given on the final part of the questionnaire after 3 months were significantly lower than those to most questions in the first part of the questionnaire. The exceptions were those questions where the subject in the given scenario was known to the respondent, where reactions were rated significantly greater ( P < 0.001) in the follow-up questionnaire and can be explained on the basis that they were a personal referent.
Students rapidly develop a coping mechanism which enables them to view cadaver dissection as an occupation quite divorced from living human beings. During these early months of training solicitude decreases for those who die who are unknown to them, but concern for personal referents increases. Educators should be aware of the dramatic change of attitudes among students and the process of professionalization which might influence their caring of future patients.     

305例老年死亡病例医院感染回顾性调查

本文结果表明,305例老年死亡病例医院感染的发病率为33.8％。感染最多部位为肺部(66.9％),其次为尿路感染(19.4％)。高龄患者,侵袭性操作、多种抗生素联合应用,激素疗法等是诱发医院感染的危险因素。58.8％的病原菌为革兰氏阴性杆菌,37.2％为真菌。31株病原菌药敏结果显示耐药率为33.3％。本文指出合理应用抗生素是预防医院感染的重要措施之一。     

SCHWANN CELLS AND THE REGROWTH OF AXONS IN THE MAMMALIAN CNS: A REVIEW OF TRANSPLANTATION STUDIES IN THE RAT VISUAL SYSTEM

1. We have used peripheral nerve transplants or cultured Schwann cells grafted in association with different types of polymer to study axonal regrowth in the rat visual system. In some instances the glia were co-grafted with fetal tectal tissue. 2. The studies have two main aims: (i) to determine whether retinal axons can be induced to regrow at a site distant from their cell soma, that is, after damage to the brachial region of the optic tract; (ii) to determine whether retinal axons exposed to Schwann cells retain the ability to recognize their appropriate target neurons in CNS tissue. 3. In brachial lesion studies, Schwann cells were placed in the lesion site in association with nitrocellulose papers, within polycarbonate tubes in the presence or absence of a supporting extracellular matrix (ECM), or within polymer hydrogel scaffolds. Autologous sciatic nerve grafts were also used. Immuno-histochemical studies revealed the presence of regenerating axons within all polymer bridges. Regrowth of retinal axons was also seen, however, growth was not extensive and was limited to the proximal 1–1.5 mm of the implants. 4. In target innervation experiments, two surgical paradigms were developed. In one experiment, a segment of sciatic nerve was autografted onto the transected optic nerve in adult rats and the distal end of each graft was placed adjacent to fetal tectal (target) tissue implanted into the frontal cortex. To date, we have not been able to demonstrate selective recognition of target regions within tectal transplants by retinal axons exiting the sciatic nerve implants. 5. In the second experiment, Schwann cells were mixed with fetal tectal cells and co-grafted to the midbrain of newborn host rats. Schwann cells altered the characteristic pattern of host retinal growth into tectal grafts; in some cases axons were induced to grow away from appropriate target areas by nearby co-grafted Schwann cells. 6. In summary, Schwann cell/polymer scaffolds may provide a useful way of promoting the regrowth of damaged axons in the CNS, however: (i) in adults, at least, their effectiveness is reduced if they are located at a distance from the cell bodies giving rise to regenerating axons; (ii) in some circumstances exposure to a peripheral glial environment may affect the capacity of regenerating axons to recognize appropriate target cells in the CNS neuropil.