Magnetic resonance imaging: absence of in vitro cytogenetic damage

Human lymphocytes and Chinese hamster ovary (CHO) cells in culture were exposed for 12 1/2 hours to a magnetic resonance imaging apparatus with a 2.35-Tesla magnet and 100-MHz radio frequency emission. The cells were examined for cytogenetic damage manifested either as chromosome aberrations or sister chromatid exchanges (SCEs), which constitute very sensitive measures of genetic and cellular damage. In either unstimulated or stimulated human lymphocytes, as well as in exponentially growing CHO cells, no increase in either chromosome aberrations or SCEs was found as a result of exposure to these MR conditions. The data indicate that long-term exposure to MR imaging conditions far exceeding those to be found in the clinical situation does not cause cytogenetic damage.     

Leucocytoclastic vasculitis associated with hepatitis C virus antibodies

The actiopathogenesis of leucocytoclastic vasculitis is still unknown, but recently hepatitis C virus (HCV) has been suggested as trigger of autoimmunity. We report a case of a 26-yr-old patient with purpura due to leucocytoclastic vasculitis associated with hepatitis C virus infection. Laboratory findings showed AST, ALT, gamma GT within normal limits, positive antibodies to HCV (IIF and Riba II) and polymerase chain reaction for HCV RNA. Anti-nuclear antibodies, IgG and IgM anti- cardiolipin antibodies, anti-platelet antibodies and anti-neutrophil cytoplasmic antibodies with perinuclear pattern were also present. A skin biopsy specimen of a purpuric lesion showed leucocytoclastic vasculitis with small vessel thrombosis and perivascular deposition of IgM and fibrinogen on immunofluorescence study. This case shows a role of HCV in leucocytoclastic vasculitis; it is possible that this HCV can induce autoimmunity independently of cryoglobulins and liver involvement.      

Why is it that internists do not follow guidelines for preventing intravascular catheter infections?

BACKGROUND AND OBJECTIVE: High morbidity of CVC-related infections has led to national guidelines for their prevention. Despite recommendations for the use of maximal barrier precautions (mask, sterile gloves, gown, and large drape) and skin antisepsis with 2% chlorhexidine gluconate during CVC insertion, internists in the United States are not implementing these practices frequently. This study sought to identify and characterize the obstacles to and potential opportunities for improving adherence. DESIGN: Cross-sectional survey. PARTICIPANTS: One thousand randomly selected physician-members of the American College of Physicians-American Society of Internal Medicine. METHODS: Several potential determinants of adherence to maximal barrier precautions were assessed, including awareness of, agreement with, and ability to implement the recommendation, as well as the practice and training characteristics of the respondents. Factors influencing antiseptic selection were also recorded. RESULTS: Of 526 respondents, 178 (34%) had recently inserted CVCs. Clinician experience and subspecialty, awareness of CDC guidelines, and external influences (eg, time to collect equipment) did not affect maximal barrier precautions adherence. The only independent predictor of adherence was high outcome expectancy for the use of large sterile drapes (OR, 5.3; CI95, 2.2-12.6). Availability had the greatest influence on internists' selection of specific antiseptic agents, whereas cost was the least important determinant. CONCLUSIONS: Despite established efficacy, use of maximal barrier precautions and chlorhexidine gluconate is low among internists. Because improved adherence to these practices will require increased outcome expectancy for maximal barrier precautions and availability of chlorhexidine gluconate, targeting these areas through focused education and systems modifications is essential.     

Platelet 3H-imipramine binding and sulphotransferase activity in primary headache

We investigated platelet ³H-imipramine (³H-IMI) binding, a putative peripheral serotonergic marker, and the activity of sulphotransferase (ST), an enzyme involved in the catabolism of catecholamines and phenolic compounds, in 14 patients suffering from migraine without aura (MWoA) and in 10 with tension-type headache (TH), as compared with a group of controls. The possible relationships between the biological parameters and clinical features were also examined. The results showed that the two groups of patients had a lower number of ³H-IMI binding sites and a lower activity of the thermolabile form of ST, which acts preferentially on monoamine substrates, than the healthy controls, with no intergroup differences. Significant correlations between psychopathological rating scales and characteristics of the illness were observed in the patients with TH. The decreased number of platelet ³H-IMI binding sites is suggestive of a presynaptic serotonergic dysfunction and confirms the involvement of 5HT in primary headaches. The reduced ST activity might produce changes in the level of sulphated biogenic amines, including dopamine and tyramine, which might have an additional role in the pathophysiology of some aspects of primary headache.     

Effectiveness of individualized neurodevelopmental care in the newborn intensive care unit (NICU)

The individual infant's neurodevelopmental process provides an integrative framework for the delivery of medical care needed to assure the infant's survival and quality of outcome. The infant's neurobehavioral functioning and expression provides an opportunity for caregivers to estimate the individual infant's current strengths, vulnerabilities and threshold to disorganization, as well as to identify the infant's strategies in collaborating in his or her best progression. This perspective supports caregivers in seeing themselves in a relationship with the infant, and in considering opportunities to enhance the infant's strengths and reduce apparent stressors in collaboration with the infant and the family. The results of several randomized studies supporting the effectiveness of such a neuro developmental approach to NICU care will be presented, and suggest implications for staff education and nursery-wide implementation.     

Risk factors for the development of bronchiolitis obliterans in children with bronchiolitis

BACKGROUND: Bronchiolitis obliterans (BO) is an uncommon and severe form of chronic obstructive lung disease in children that results from an insult to the lower respiratory tract. METHODS: A case-control study of children under the age of 3 years was performed in 109 cases and 99 controls to determine risk factors for the development of BO. Participants were evaluated by immunofluorescence viral tests, pulmonary function tests, and questions to assess tobacco and other exposures. RESULTS: Bronchiolitis due to adenovirus (odds ratio (OR) 49, 95% confidence interval (CI) 12 to 199) and the need for mechanical ventilation (OR 11, 95% CI 2.6 to 45) were strongly and independently associated with an increased risk for BO. Factors not associated with post-infectious BO included age of the child, sex, and environmental tobacco exposure (either in utero or during infancy). CONCLUSIONS: Adenovirus infection and need for mechanical ventilation are significant risk factors for developing BO in children. Further research is needed to determine why these risk factors are so strong and how they may contribute to the development of the disease.