Scalp electrical recording during paralysis: quantitative evidence that EEG frequencies above 20 Hz are contaminated by EMG.

OBJECTIVE: To identify the possible contribution of electromyogram (EMG) to scalp electroencephalogram (EEG) rhythms at rest and induced or evoked by cognitive tasks. METHODS: Scalp EEG recordings were made on two subjects in presence and absence of complete neuromuscular blockade, sparing the dominant arm. The subjects undertook cognitive tasks in both states to allow direct comparison of electrical recordings. RESULTS: EEG rhythms in the paralysed state differed significantly compared with the unparalysed state, with 10- to 200-fold differences in the power of frequencies above 20 Hz during paralysis. CONCLUSIONS: Most of the scalp EEG recording above 20 Hz is of EMG origin. Previous studies measuring gamma EEG need to be re-evaluated. SIGNIFICANCE: This has a significant impact on measurements of gamma rhythms from the scalp EEG in unparalysed humans. It is to be hoped that signal separation methods will be able to rectify this situation.     

Intrathoracic carcinoma in an 11-year-old girl showing a translocation t(15;19).

We report here a rare case of intrathoracic undifferentiated carcinoma in an 11-year-old girl. The biopsy tissue stained with antibodies against cytokeratin and carcino-embryonic antigen. The same staining was obtained using a cell line, PER-403, which was derived from the tumor. DNA from PER-403 cells was tested for the presence of Epstein-Barr virus genes, yielding a negative result. The cytogenetic analysis found a translocation t(15;19) (p12;q13), which has not previously been described in a carcinoma.     

Infarction of the conus medullaris

We describe 5 patients who presented with an acute cauda equina syndrome, which we believe was due to infarction of the conus medullaris. In 3 patients, the onset was spontaneous, and in 2 patients it was secondary to temporary occlusion of the distal aorta during medical manipulation. Pain in the buttocks and posterior thighs was a prominent initial symptom in the 3 patients with unprovoked attacks. The main clinical features were profound impairment of bowel and bladder function and of perianal and perineal sensation (S3 to S5 segments). There was sensory and motor impairment in the legs of variable extent, most marked in the S1 and S2 segments, but extending as high as L4 in 2 patients. In 1 patient, ischemic changes in the conus medullaris were confirmed post mortem. Ischemia confined to the caudal tip of the spinal cord is rare, and an underlying anomaly of the pattern of arterial supply is a likely predisposing factor. Four patients had partial return of function over a period of weeks.     

Human immunodeficiency virus infection in pregnant women under care at AIDS clinical trials centers in the United States.

The federal government supports a nationwide network of medical centers to evaluate promising therapies against the human immunodeficiency virus (HIV) and the opportunistic infections and cancers that characterize AIDS. Forty-five obstetricians from the 49 medical centers receiving federal research support for the conduct of AIDS-related clinical trials, in preparation for a meeting, provided summary information about the number and clinical status of the known HIV-infected pregnant women under their care and the prenatal screening policies for HIV infection at their institutions. In the 12-month period before December 1989, an estimated 1000-1801 HIV-infected women delivered at these centers. The majority (82%) were asymptomatic, 12% were symptomatic, and 6% had AIDS. Routine T-cell testing of infected women was done as part of prenatal care in only 30 of 45 centers. Pneumocystis carinii pneumonia was reported in 35 women. Zidovudine was administered during pregnancy in 29 women. Formal prenatal screening policies have been implemented at the majority (43 of 45) of the medical centers. Most of the infected women identified at these centers chose to continue the pregnancy. With the increasing incidence of HIV infection in women, information concerning the clinical and immunologic state of pregnant infected women and the present use of antiretroviral and other related therapeutics during pregnancy can guide the approach to women's health care and is crucial to the design and implementation of AIDS clinical trials.     

Implementation of a successful endovascular surgical program in a non-teaching tertiary-care centre in Ontario.

Endovascular surgical techniques have become an accepted standard of care for high-risk patients with abdominal aortic aneurysms and for certain patients with thoracic aortic pathology and peripheral arterial aneurysms. In Canada, endovascular surgery has been concentrated in tertiary-care academic teaching institutions. As the technology evolves and as expertise advances, the applicability of endovascular techniques will expand. With time, and as the demand for endovascular techniques rises, this expertise will increasingly need to be delivered by dedicated vascular surgical services in nonteaching institutions. The dissemination of endovascular surgical capabilities represent a unique challenge. We report the successful implementation of an endovascular surgical program in a tertiary-care nonteaching institution using a carefully planned preceptorship model. We review our initial 49 cases and discuss 6 factors important to the successful establishment of an endovascular surgical service: education, teamwork, strict selection of patients, use of a single stent-graft manufacturer, industry support and endovascular preceptorship. Our experience may be used as a model by other institutions in Canada.     

Effects of methylphenidate and behavior modification on the social and academic behavior of children with disruptive behavior disorders: the moderating role of callous/unemotional traits.

This study examined whether response to behavior modification with and without methylphenidate differed for children with attention-deficit/hyperactivity disorder (ADHD) and conduct problems (CP) depending on the presence of callous/unemotional (CU) traits. Participants were 37 children ages 7 to 12, including 19 with ADHD/CP-only and 18 with ADHD/CP-CU, referred to a university-based summer treatment program. Results showed that ADHD/CP-CU children had worse behavior in the behavior-therapy-only (BT-only) condition, especially on measures of CP, noncompliance, and rule violations, but these differences largely disappeared when medication was added to BT. Children with ADHD/CP-CU were also less likely to be normalized by treatment than were children with ADHD/CP-only. These findings, though tentative, suggest that children with ADHD/CP-CU may not show a sufficient positive response to BT alone and that the combination of medication and BT may be especially important for them.     

Lymph node infarction – a rare complication associated with disseminated intra vascular coagulation in a case of dengue fever

Background  

Lymph node infarction is known to occur in association with many non-neoplastic and neoplastic conditions however its occurrence in association with DIC is not reported hitherto in the literature.     

Excitation of neuronal function in rabbit caudal ventrolateral medulla elevates plasma vasopressin

Injection of L-glutamate into the caudal ventrolateral medulla of the rabbit caused a dose-dependent increase in plasma vasopressin. Activity of the A1 noradrenergic cells within the caudal ventrolateral medulla appears to excite the vasopressin-secreting neuroendocrine cells within the hypothalamus.     

Increased inflammatory reactivity in newly formed lining tissue

The air pouch has been shown to provide a convenient model for studying the behaviour of synovial lining tissue. Air pouches of different ages were used to study the reactivity of newly developing lining tissue towards irritants known to cause inflammation. Pouches of 1 day in age were relatively inert in their reactivity as judged by the number of cells and volume of the exudate accumulating in the pouch. In contrast, 3-day-old pouches responded to a much greater extent, and 6-day-old pouches were highly responsive with a further increase in cell numbers and fluid volume. The different responses of 1-, 3- and 6-day-old pouches could be explained by (a) developing vascularity of the pouch, (b) formation of an organised lining of phagocytic cells, or (c) an increasingly organised mechanical barrier that retains the irritant and products of the inflammatory response. These studies of air pouch lining development permit a dissection of those components necessary for inflammatory reactivity of a lining tissue and may help explain the sensitivity of synovium to chronic inflammation.