A crystal camera for ultra-small-angle x-ray scattering using synchrotron radiation

We describe a novel USAXS camera that combines the use of synchrotron radiation with collimation by perfect-crystal optics. The outstanding result is that high measuring intensities and extreme angular resolution are achieved even with a point-focusing geometry. Along the principles of the original design (U. Bonse and M. Hart, Z. Phys. 189, 151 (1966)) which had to be operated at an x-ray tube, we employ two sets of pairs of multiply reflecting channel-cut crystals diffracting in the horizontal and vertical planes. The collimation characteristics thus obtained are equivalent to the point-focusing geometry of conventional SAXS cameras based on slit collimation. We present results from samples of polystyrene spheres which were used for test measurements performed with synchrotron radiation of DORIS at HASYLAB/DESY in Hamburg. Taking into account the number of reflections within the channel-cut crystals, the theoretical resolution was calculated and found to agree well with that derived from measured scattering patterns. Structures as large as about 1.3 μm could easily be identified from the scattering curves. As expected with point-focusing geometry, desmearing of raw data was unnecessary.     

Inter-laboratory validation of PCR-based detection of Mycobacterium tuberculosis in formalin-fixed, paraffin-embedded tissues

The present study is based on the initiative for quality assurance in pathology of the German Society of Pathology and the Professional Association of German Pathologists. Four panel laboratories with experience and expertise in polymerase chain reaction (PCR) detection of Mycobacterium tuberculosis were selected to establish the prerequisites for continuous external laboratory trials, in particular, by providing pre-tested specimens and evaluation criteria for participating institutes. In the first step, the four panel laboratories performed an internal trial to test their own reliability and reproducibility. Paraffin sections and DNA preparations from 34 tissues (25 clinical specimens and 9 controls) totalling to 66 samples were evaluated by each panel institute according to their own protocols. The methodologies differed and are described in detail. Despite these differences, a high degree of inter-laboratory reliability was achieved. In this report, we summarise our results including the correlation with the histology and provide recommendations for applying PCR-based methodology for the detection of mycobacterial DNA in surgical specimens. Supplementary data are available online at (rubric Forschung). Pre-tested specimens are now available for the external trial and can be ordered from the steering institute via Oligene (). All molecular pathology laboratories are invited to participate in this quality assurance initiative.     

Nicotine dependence and problem behaviors among urban South African adolescents

Tobacco use and its concomitant, nicotine dependence, are increasing in African countries and other parts of the developing world. However, little research has assessed nicotine dependence in South Africa or other parts of the African continent. Previous research has found that adolescent problem behaviors, including tobacco use, tend to cluster. This study examined the relationship between nicotine dependence and adolescent problem behaviors in an ethnically diverse sample of urban South African adolescents. A community sample (N = 731) consisting of “Black,” “White,” “Coloured,” and “Indian” youths aged 12–17 years was drawn from the Johannesburg metropolitan area. Structured interviews were administered by trained interviewers. Nicotine dependence was assessed by the Fagerström Test of Nicotine Dependence. Logistic regression analyses showed that higher levels of nicotine dependence significantly predicted elevated levels of violent behavior, deviant behavior, marijuana and other illegal drug use, binge drinking, early sexual intercourse, multiple sexual partners, and inconsistent condom use, despite control on the adolescents’ demographic characteristics, peer smoking, conflict with parents, peer deviance, and the availability of legal and illegal substances. These relationships were robust across ethnicity and gender. The findings indicate the need for policy makers and prevention and intervention programs in South Africa to consider adolescent nicotine dependence in conjunction with comorbid problem behaviors, including other substance use, sexual risk behaviors, and deviant behaviors.     

Intra-articular osteochondroma of the posterior cavity of the knee

A patient with a large intra-articular osteochondroma of the posterior cavity of the knee joint is presented. Preoperative imaging included radiographs and magnetic resonance imaging, which revealed a completely intra-articular, locally expanding, mineralised mass in the intercondylar tunnel and posterior joint cavity. Flexion was limited to 70 deg. The osteochondroma was removed from a posterior approach. Gross and histologic pictures are presented, and the origin and pathogenesis of the tumour are discussed. After removal, the clinical course was benign. Full flexion was regained within 2 months. At the 2-year follow-up, no signs of recurrence were evident on radiographs and magnetic resonance imaging.     

Thin section arrays for I-FISH analysis of chromosome-specific imbalances in squamous cell carcinomas of the head and neck

Thin section arrays of 20 head and neck squamous cell carcinomas were studied by I-FISH for gains (including amplification) and losses of specific genomic segments. These arrays allow the examination not only of a number of tumor sections but also of the surrounding margins and of inconspicuous control tissue in one experiment. All tumor sections examined significantly differed from the inconspicuous control tissues by containing more or less extensive cell populations with aberrant signal constitutions. In no case, however, did the aberrant population constitute the whole area of the section. Gains of signals were strikingly more frequent than were losses. All tumors showed significant gains of the segments examined, the highest differences between tumor and control sections were found for the segments 9q34 and 8q24, followed by 5p15.3 and 11q13. Amplifications were most frequently found of 11q13: 8 of the 20 tumors showed amplifications in more than 20% of the nuclei, while no nucleus with more than four signals was found in any of the control tissues (control: 0%). Amplifications of the target sequences on chromosomes 8 (14 tumors) and 9 (8 tumors) were observed in low but significant percentages of nuclei, no significant cell population was detected with an amplification of 5p15.3. Fourteen tumors exhibited a significant loss of 13q14, and only 8 tumors a significant loss at any other site. In the tumor margin sections, in most cases, the margins apparently were also affected by the one or the other of the genomic changes of the pertinent primary tumor. Nevertheless, there were, in some cases, also large differences depending on the way of analysis, but also on the specific signal constitution considered. Tumor stages T3 and T4 tended to have higher frequency of nuclei with gains of 5p15.3, 8q24, and 11q13 as compared to T2 tumors and less gains of 9q34 and loss of 13q14. With the exception of 8q24 and 13q14 alterations there was also a trend to higher percentages of aberrant nuclei in the margin of T3-4 tumors vs. T2 tumors.     

Glucocorticoid effects on the inflammatory and clinical responses to cardiac surgery

OBJECTIVE: To measure the effects of glucocorticoids on the systemic inflammatory response and clinical recovery after cardiac surgery. DESIGN: Randomized, prospective, double-blind, placebo-controlled clinical trial with concurrent comparison groups. SETTING: University medical center. PARTICIPANTS: Patients scheduled for elective coronary artery bypass graft surgery using normothermic cardiopulmonary bypass (CPB) and a standardized anesthetic. INTERVENTIONS: Participants randomly received either methylprednisolone, 15 mg/kg intravenously 1 hour before surgery and 0.3 mg/kg intravenously every 6 hours x 4 doses, or placebo. Comparison groups included cardiac surgical patients who received etomidate to lower endogenous cortisol during surgery and healthy volunteers who received methylprednisolone only. MEASUREMENTS AND MAIN RESULTS: Patients who received methylprednisolone had a significant reduction in circulating interleukin (IL)-6 at 60 minutes after CPB (p < 0.05) and on the morning of the 1st (p < 0.01) and 3rd (p < 0.05) postoperative days and a significant increase in circulating IL-10 at 60 minutes after CPB (p < 0.01) compared with the placebo group. Etomidate, given to lower cortisol during surgery, was associated with significantly decreased IL-6 and IL-10 responses to surgery compared with the placebo group, whereas methylprednisolone alone, given to healthy nonsurgical volunteers, had no effect on these cytokines. After adjusting for age, there were no significant differences in postoperative length of hospital stay between the methylprednisolone-treated (4.6 days) and placebo (6.1 days) groups or in the duration of mechanical ventilation (9.9 hours and 15.6 hours). No patient treated with methylprednisolone had nausea and vomiting on the 1st postoperative day compared with 33% of placebo-treated patients (p = 0.02). Glucose was significantly higher after methylprednisolone treatment at 1 hour after CPB (276 mg/dL v 210 mg/dL; p = 0.001) and at 2 hours (289 mg/dL v 213 mg/dL; p = 0.009) and 8 hours (247 mg/dL v 196 mg/dL; p = 0.02) after surgery. There were no differences in pain scores and no significant intergroup differences in lung peak expiratory flow rate or alveolar-arterial oxygen gradients after surgery. CONCLUSION: This study shows significant effects of glucocorticoids on the production of IL-6 and IL-10 in response to cardiac surgery but only minor effects on clinical recovery.     

Nerve injury proximal or distal to the DRG induces similar spinal glial activation and selective cytokine expression but differential behavioral responses to pharmacologic treatment

The specific mechanisms by which nervous system injury becomes a chronic pain state remain undetermined. Historically, it has been believed that injuries proximal or distal to the dorsal root ganglion (DRG) produce distinct pathologies that manifest in different severity of symptoms. This study investigated the role of injury site relative to the DRG in (1) eliciting behavioral responses, (2) inducing spinal neuroimmune activation, and (3) responding to pharmacologic interventions. Rats received either an L5 spinal nerve transection distal to the DRG or an L5 nerve root injury proximal to the DRG. Comparative studies assessed behavioral nociceptive responses, spinal cytokine mRNA and protein expression, and glial activation after injury. In separate studies, intrathecal pharmacologic interventions by using selective cytokine antagonists (interleukin-1 [IL-1] receptor antagonist and soluble tumor necrosis factor [TNF] receptor) and a global immunosuppressant (leflunomide) were performed to determine their relative effectiveness in these injury paradigms. Behavioral responses assessed by mechanical allodynia and thermal hyperalgesia were almost identical in the two models of persistent pain, suggesting that behavioral testing may not be a sensitive measure of injury. Spinal IL-1beta, IL-6, IL-10, and TNF mRNA and IL-6 protein were significantly elevated in both injuries. The overall magnitude of expression and temporal patterns were similar in both models of injury. The degree of microglial and astrocytic activation in the L5 spinal cord was also similar for both injuries. In contrast, the pharmacologic treatments were more effective in alleviating mechanical allodynia for peripheral nerve injury than nerve root injury, suggesting that nerve root injury elicits a more robust, centrally mediated response than peripheral nerve injury. Overall, these data implicate alternate nociceptive mechanisms in these anatomically different injuries that are not distinguished by behavioral testing or the neuroimmune markers used in this study.     

The in vivo effects of general and epidural anesthesia on human immune function

Impaired in vivo immunity is often observed after major surgery and is multifactorial. We conducted a randomized clinical study to determine the independent effects of general anesthesia (GA) and of lumbar epidural anesthesia (LEA) on human immune function in the absence of surgical trauma. Nineteen healthy volunteers were randomized to receive GA with thiopental and isoflurane, LEA with lidocaine, or no anesthesia (Control). Serial blood samples were tested for antibody responses to antigen inoculation, neutrophil and mononuclear cell antibody-dependent cell cytotoxicity (ADCC), natural killer cell cytotoxicity, and neutrophil phagocytic activity. Antibody responses were similar in the three groups. Mononuclear cell ADCC increased in the LEA group at the end of the anesthetic (P < 0.05 at effector/target [E/T] ratios of 10:1, 25:1, and 50:1). Natural killer cell cytotoxicity increased at the end of the anesthetic in both the LEA group (P < 0.05 at all E/T ratios) and the GA group (P < 0.05 at an E/T ratio of 5:1 and 10:1). No significant changes were observed for neutrophil ADCC or phagocytosis. General or epidural anesthesia alone, in the absence of surgery, seems to have only transient and minor effects on human immune function. IMPLICATIONS: General or epidural anesthesia alone, in the absence of surgery, seems to have only transient and minor effects on human immune function.     

Persistent hyperinsulinemic hypoglycemia of infancy: case report

OBJECTIVE: To report a case of Persistent Hyperinsulinemic Hypoglycemia in twins which is a situation not yet reported in the literature. METHODS: Report of seizures in identical twins, from consanguineous parents, with persistent hypoglycemia as cause of the seizures. Laboratory tests, performed for etiological investigation of the hypoglycemia, included thyroid hormones (T4/TSH), insulin, cortisol, growth hormone, stimulation test with glucagon (to evaluate the insulin/glucose relation), and histopathological study of the pancreas. RESULTS: Laboratorial investigation revealed a persistent hypoglycemia with hyperinsulinism which were confirmed with the stimulation test with glucagon. The histopathological exam showed a persistence of first generation pancreatic islet, confirming the diagnosis of Persistent Hyperinsulinemic Hypoglycemia in Infancy (the new denomination of Nesidioblastosis). CONCLUSION: Although rare, this condition must be early suspected early in the evaluation of hypoglycemia of the young infant, even out of the neonatal period, specially if the parents are consanguineous. The adequate therapy must be quickly initiated in order to prevent neurological damage.