RF refocused echoes of J-coupled spin systems: effects on RARE-based spectroscopic imaging.

A numerical simulation tool was developed to calculate the echo amplitudes of J-coupled resonances within a series of radiofrequency (RF) refocused echoes. The signal modulation due to J-coupling in rapid acquisition with relaxation enhancement (RARE) is suppressed only when the inverse of the pulse interval (tau) is large compared to both the chemical shift (CS) difference (Deltadelta) of the coupled spins and the coupling constant. In contrast, the echo amplitudes in ultrafast low-flip-angle RARE (U-FLARE) oscillate around a quasi-steady-state value that is greater than zero (neglecting relaxation and diffusion) even when Deltadelta > 1/tau. The flip-angle distribution over the measured slice caused by the use of Gaussian-shape slice-selective refocusing pulses further reduces the echo oscillations. When the pulse interval falls short of the fast pulse rate regime, spectroscopic U-FLARE provides an improved spatial impulse response in the phase-encoding (PE) direction compared to spectroscopic RARE.     

Ainhum

Ohne Zusammenfassung     

Entwicklung einer neuen Säuglingsnahrung mit Thermobacterium bifidum. Ein Beitrag zum Problem der Sauermilchnahrung

Ohne Zusammenfassung     

Inhaled iloprost to control residual pulmonary hypertension following pulmonary endarterectomy

Objective: Pulmonary endarterectomy (PEA) is the standard therapy for patients with chronic thromboembolic pulmonary hypertension (CTEPH). In the immediate postoperative period, persistent pulmonary hypertension increases the risk of acute respiratory or right heart failure. In pulmonary arterial hypertension, prostanoid inhalation has been found to improve pulmonary hemodynamics, right ventricular function, gas exchange, and clinical outcome. We report the results of a double-blinded randomized trial with the aerosolized prostacyclin analogue iloprost in patients with residual pulmonary hypertension after PEA. Methods: Twenty-two patients (age, 55 ± 13 years; 8 females; propofol- and sufentanil-based anesthesia; pressure-controlled mechanical ventilation) were randomized to receive either a single dose of 25 μg aerosolized iloprost (iloprost group; n = 11) or normal saline (placebo group; n = 11) immediately after postoperative ICU admission. Primary endpoints were changes in gas exchange, pulmonary and systemic hemodynamics, and clinical outcome. Results: Iloprost significantly enhanced cardiac index (CI) and reduced mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance [PVR (dyn s cm⁻⁵)] in contrast to placebo. Placebo: pre-inhalation 413 ± 195 versus post-inhalation 404 ± 196 at 30 min (p = 0.051), 415 ± 189 at 90 min (p = 0.929). Iloprost: pre-inhalation 503 ± 238 versus post-inhalation 328 ± 215 at 30 min (p = 0.001), 353 ± 156 at 90 min (p = 0.003). Blood oxygenation remained unchanged. Conclusion: In addition to the effect of PEA, iloprost reduces residual postoperative pulmonary hypertension, decreases right ventricular afterload and may facilitate the early postoperative management after PEA.     

Primary spinal intramedullary malignant lymphoma. A case report

A rare case of primary malignant intramedullary lymphoma, localized in the cervical part of the spinal cord, is presented. The onset of clinical symptoms was associated with herpes zoster infection. Surgery led to the histological diagnosis. The clinical investigations excluded the presence of lymphoma in other sites in the central nervous system and in the extraneural organs. Postoperative irradiation and chemotherapy effected relict of neurological symptoms.     

Effects of HIV antibody test knowledge on subsequent sexual behaviors in a cohort of homosexually active men.

This study assesses the effects of HIV (human immunodeficiency virus) antibody testing on subsequent (one year) sexual behavior among 270 homosexual men at a Boston community health center, 21 per cent of whom were unaware of their test result. Except for the number of steady partners, the levels of all sexual activities of all groups of study participants declined over time. No effects of test awareness of antibody status were found on protective behavior for receptive anogenital contact. Elimination of unprotected insertive anogenital contact (by elimination of the practice or by condom use) was reported somewhat more often among seropositive men who became aware of their test result. Increased negative emotional reactions were reported by HIV seropositive men who were aware of their test result. These results suggest some behavioral impact of HIV antibody test knowledge in this cohort, but may not be generalizable to other populations.     

Scleral fibroblasts. Human leukocyte antigen expression and complement production

The authors investigated the ability of recombinant human gamma-interferon (rhIFN-gamma) to influence production of complement and expression of human leukocyte antigens (HLA) by human scleral fibroblasts in culture. Cell cultures were established by explanting sclera from normal human donor eyes. To study complement production, fibroblasts were treated with 500 units/ml rhIFN-gamma in cell culture, and media were tested for complement components by hemolytic assay after 0, 1, 3, 6, 9, and 11 days. To induce Class II HLAs, fibroblasts were exposed to rhIFN-gamma at concentrations ranging from 10-500 units/ml and incubated for 1, 3, and 6 days. The HLAs were detected by immunofluorescence in conjunction with flow cytometry. Class I antigen was detected using a monoclonal antibody directed against beta 2-microglobulin. Class II histocompatibility antigens were identified using monoclonal antibodies specific for HLA-DR, -DP, and -DQ. Although complement component C1 was produced constitutively in cell culture, the addition of rhIFN-gamma resulted in an increase in production. Complement components C2 and C4 were detected only after treatment with rhIFN-gamma. Complement production was completely inhibited by cycloheximide, and C3, C5, C6, and C7 were not present in cell culture media with or without rhIFN-gamma. Class I antigen was present on all cells before induction, and an increase in expression was noted after exposure to rhIFN-gamma. Class II antigens were absent before induction with rhIFN-gamma. After treatment with rhIFN-gamma, scleral fibroblasts expressed HLA-DR, -DP, and -DQ in a dose-dependent, time-related fashion. These findings suggest that rhIFN-gamma has multiple effects on scleral fibroblasts: (1) increased production of C1, (2) production of C2 and C4, (3) up-regulation of Class I antigen expression, and (4) expression of Class II antigens. They also suggest that scleral fibroblasts have the potential to participate in immunologic diseases of the eye.     

Intestinal permeability after single dose gluten challenge in coeliac disease.

The changes of intestinal permeability before and after a gluten load were studied. The study group comprised 27 patients with coeliac disease (mean age 12.3 years) and 19 healthy controls matched by sex and age. Intestinal permeability was studied by measuring the urinary excretion of two sugars, lactulose and L-rhamnose, before and six hours after the ingestion of five palatable biscuits made with 50 g of gluten powder. The patients with coeliac disease had been on a gluten free diet during the previous two years. After the gluten load lactulose and L-rhamnose urinary excretion changed significantly in patients, and a significant increase in the lactulose: L-rhamnose ratio was also observed. No significant changes were observed in the controls. In view of the modification of the three biopsies diagnostic protocol made by the European Society for Paediatric Gastroenterology and Nutrition, permeability tests associated with single gluten challenges may be an added contribution to the accuracy of the diagnosis in childhood.     

The mentored clinical casebook project at Harvard Medical School.

An excellent physician must be aware of the countless issues that affect each patient's health. Many medical education programs expose students to a broad spectrum of disparate knowledge and hope they will integrate all the pieces into a coherent whole. The authors describe an explicit approach to integration used at Harvard Medical School since 2003 that aims to enhance students' learning in medical school and throughout their medical careers: the Mentored Clinical Casebook Project (MCCP). The MCCP is constructed on the premise that such integration does not occur suddenly but, rather, is an unending process. A first-year student is assigned to one clinician and follows one patient for one year. The student is expected to spend as much time with the patient as possible, in both clinical and nonclinical settings, seek help from the clinician, and consult other experts and sources to develop a complete picture of the patient's life. The student must produce a casebook that includes, but is not limited to, the patient's history; basic science, clinical, socioeconomic, and cultural issues; and self-reflection. The MCCP is intended to allow students to develop a deeper and more diverse understanding of what comprises a patient's health care life, to discern the patient as a person and the person as a patient. This educational project has been popular with students since its inception, providing them with a personal framework from which to address the needs of future patients and introducing them to how much they will continue to learn from their patients.     

Increased numbers of interleukin-12-producing cells in human tuberculosis.

Numbers of interleukin-12 (IL-12) producing cells were quantitated in the peripheral blood of healthy donors and tuberculosis patients by the ELISPOT assay. We observed that (i) stimulation with mycobacteria increases numbers of IL-12 producers from healthy donors and (ii) tuberculosis patients have larger numbers of IL-12 producers than healthy donors. Our data emphasize the importance of Il-12 in immunity to tuberculosis.