Reproducibility of proton MR spectroscopic imaging (PEPSI): comparison of dyslexic and normal-reading children and effects of treatment on brain lactate levels during language tasks

BACKGROUND AND PURPOSE: We repeated a proton echo-planar spectroscopic imaging (PEPSI) study to test the hypothesis that children with dyslexia and good readers differ in brain lactate activation during a phonologic judgment task before but not after instructional treatment. METHODS: We measured PEPSI brain lactate activation (TR/TE, 4000/144; 1.5 T) at two points 1-2 months apart during two language tasks (phonologic and lexical) and a control task (passive listening). Dyslexic participants (n = 10) and control participants (n = 8) (boys and girls aged 9-12 years) were matched in age, verbal intelligence quotients, and valid PEPSI voxels. In contrast to patients in past studies who received combined treatment, our patients were randomly assigned to either phonologic or morphologic (meaning-based) intervention between the scanning sessions. RESULTS: Before treatment, the patients showed significantly greater lactate elevation in the left frontal regions (including the inferior frontal gyrus) during the phonologic task. Both patients and control subjects differed significantly in the right parietal and occipital regions during both tasks. After treatment, the two groups did not significantly differ in any brain region during either task, but individuals given morphologic treatment were significantly more likely to have reduced left frontal lactate activation during the phonologic task. CONCLUSION: The previous finding of greater left frontal lactate elevation in children with dyslexia during a phonologic judgment task was replicated, and brain activation changed as a result of treatment. However, the treatment effect was due to the morphologic component rather than the phonologic component.     

颅内动脉瘤栓塞后并发脑缺血的原因分析

1 临床资料我们总结2004-02/2004-06在第四军医大学唐都医院神经外科住院行栓塞治疗颅内动脉瘤患者27(男12,女15)例,年龄32～72岁.     

Unusual presentation of perirenal lung metastases

Lung cancer is not commonly known to metastasise to the perirenal space, with only five such cases previously published. We present an unusual case of perirenal lung metastases manifesting as diffuse perinephric stranding which to our knowledge has not been described before.     

Lymphoscintigraphy in the diagnosis of lymphatic leak after surgical repair of femoral artery injury

PURPOSE: Technetium-99m-labeled sulfur colloid lymphoscintigraphy is useful to evaluate lower extremity lymphatic circulation in cases of possible lymphedema and to reveal abnormal lymphatic collections. Groin lymphatic fistulas and lymphoceles are known complications of peripheral vascular surgical procedures. The authors describe a patient with ascites that developed into right lower extremity swelling after surgical repair of a femoral artery injury. Even after surgical ligation of multiple lymphatic channels, the patient continued to have lymphorrhea. It was unclear whether this was attributable to a persistent lymphatic leak or an ascitic leak from a postsurgical defect resulting in an abnormal connection with the peritoneal cavity. METHODS: Lymphoscintigraphy of the lower extremities was performed using Tc-99m sulfur colloid. Images were obtained at several intervals after injection of the radiotracer. Images were also acquired after the wound packing was removed. RESULTS: The images revealed an accumulation of radiotracer in the right groin, confirming the lower extremity lymphatic origin of the collection. CONCLUSIONS: Lymphoscintigraphy is useful to evaluate the origin of serous collections in the groin, a region in which lymphatic complications of vascular surgery are not uncommon.     

High prevalence of HIV infection among homeless and street-involved Aboriginal youth in a Canadian setting

Aboriginal people experience a disproportionate burden of HIV infection among the adult population in Canada; however, less is known regarding the prevalence and characteristics of HIV positivity among drug-using and street-involved Aboriginal youth. We examined HIV seroprevalence and risk factors among a cohort of 529 street-involved youth in Vancouver, Canada. At baseline, 15 (2.8%) were HIV positive, of whom 7 (46.7%) were Aboriginal. Aboriginal ethnicity was a significant correlate of HIV infection (odds ratio = 2.87, 95%CI: 1.02 – 8.09). Of the HIV positive participants, 2 (28.6%) Aboriginals and 6 (75.0%) non-Aboriginals reported injection drug use; furthermore, hepatitis C co-infection was significantly less common among Aboriginal participants (p = 0.041). These findings suggest that factors other than injection drug use may promote HIV transmission among street-involved Aboriginal youth, and provide further evidence that culturally appropriate and evidence-based interventions for HIV prevention among Aboriginal young people are urgently required.     

Accuracy of passive ankle joint positioning during quiet stance in young and elderly subjects

Age-related postural deficits elicit compensatory mechanisms such as ankle dorsiflexion in the elderly. To gain further insight into this problem, the ability to match an ankle angle during quiet stance was studied in 12 elderly and 12 young subjects. Following an initial single limb angular perturbation presented in the ±4° range, a subject had to return a tilt platform to level, as determined by the nonperturbed limb. Elderly subjects exhibited significant positive (0.9°) over-shoot of the level position, in contrast to young subjects who matched ankle angle with a mean error of −0.1°. The elderly group also exhibited an increase in positioning error for angular displacements in the range between −1 and +1°. The results document age-related postural changes in ankle positioning which might affect postural stability in older adults.     

Party drugs: properties, prevalence, patterns, and problems

This review summarizes the latest literature on "party" or "club" drugs, defined as MDMA, GHB, ketamine, and Rohypnol, as published from 2002 to early 2005. Club drugs have been categorized as being used at raves and dance parties. The literature shows that each drug has different properties, users, and settings. Each drug has different adverse effects and requires different acute care protocols. Although these drugs were identified early, scientific information about them, including the toxicological tests to identify them, is still evolving. Increasing numbers of studies on the short- and long-term effects of these drugs on humans are being published, but because of limitations on research using human subjects, they may not always be as rigorous as desired and can be cited by drug users to discredit findings of harm. The lack of research-based information on these drugs has led to the emergence of web sites that may or may not provide accurate data. Evaluated chemical dependency treatment protocols using the latest research for each of these different drugs are needed.     

The behavioral thermoregulatory response of febrile female rats is not attenuated by vagotomy

An oft-overlooked consequence of fever is the occurrence of thermoregulatory heat-seeking/producing behaviors. Subdiaphragmatic vagotomy attenuates fever resulting from low dose, peripherally administered pyrogens, suggesting that the vagus is involved in generating the pathogen-induced rise in core body temperature (T(c)). This study was designed to confirm that rats utilize behavioral thermoregulation to augment fever following systemic administration of lipopolysaccharide (LPS), and to test the hypothesis that, in febrile animals, vagotomy would block the preference for a higher ambient temperature (T(a)) as T(c) is rising. First, female Sprague-Dawley rats received IP injections of either saline or LPS (50 microg/kg), prior to placement inside a thermal gradient that offered subjects T(a) values between 7 and 45 degrees C. LPS injection caused significant increases in T(c) and selection of a higher T(a) as compared to saline administration. Second, groups of rats were vagotomized, sham-vagotomized or received no surgery, and then underwent the same gradient testing procedure. Vagotomy attenuated LPS-induced fever, but did not influence the concomitant behavioral thermoregulatory response. All groups selected comparable, higher T(a) values following LPS vs. saline. These data suggest that the reduction in the febrile response to LPS administration following vagotomy is not due to inhibition of the behavioral thermoregulatory response to the pyrogen. Rather, this behavioral response to LPS appears to be mediated by a nonvagal mechanism.