Malignant glioma-derived soluble factors regulate proliferation of normal adult human astrocytes.

Malignant gliomas are characteristically surrounded by marked gliosis. To assess whether glioma-derived products contribute to the proliferation of astrocytes, a feature of the gliosis response, we evaluated the influence of culture supernatants from malignant human glioma lines and tumor cyst fluids collected from two patients with glioblastoma multiforme on the proliferation of non-transformed adult human astrocytes. Both the culture supernatants and cyst fluids significantly increased DNA synthesis in astrocytes as assessed by a double immunofluorescence glial fibrillary acidic protein-bromodeoxyuridine technique. The net proliferative effect mediated by glioma cell line supernatants was tumor growth phase-dependent, being preferentially expressed during the logarithmic phase of glioma cell growth. Specific growth factor molecules and cytokines known to be secreted by gliomas (epidermal growth factor, fibroblast growth factor, platelet-derived growth factor, transforming growth factor-beta, interleukin-6, and tumor necrosis factor-alpha) could not reproduce the mitogenic effects of the glioma-derived soluble factors. Cytokines which can induce DNA synthesis by adult human astrocytes in vitro, gamma-interferon and interleukin-1, were not detected in the culture supernatant of glioma lines used in this study. In conjunction with the documented effects of glioma products on endothelial and lymphoid cells, the current study suggests that soluble glioma products can contribute to the production of surrounding gliosis observed in vivo.     

Improving recovery following cardiac surgery: a randomized clinical trial*

To enhance individual and family health during recovery from heart surgery, this study employed nursing interventions based on self-efficacy and family stress theory during the hospitalization period and for 3 months thereafter. The effectiveness of the interventions were assessed through a randomized trial in which 67 prospective bypass and valve surgery patients, aged 30-77 years, and their spouses, were allocated either the experimental interventions or usual care and followed for 6 months. At 3 months post-surgery, the only statistically significant differences between the experimentals and controls were on perceived self-efficacy for lifting and tolerating emotional distress. At 6 months no significant differences were found on individual or family measures. Analyses revealed that age, gender and preoperative cardiac status significantly affected individual recovery. The study is continuing with a larger sample in order to explicate the recovery process and to better determine whether a low intensity nursing intervention can effect changes in individual and family recovery.     

An Inbred Epilepsy-Prone Substrain of BALB/c Mice Shows Absence of the Corpus Callosum, an Abnormal Projection to the Basal Forebrain, and Bilateral Projections to the Thalamus

BALB/c mice lack a corpus callosum in about 11% of the population.Two inbred substrains of BALB/c mice, epilepsy-prone (EP) andepilepsy-resistant (ER), have been examined to determine whetherthese substrains differ in regard to corpus callosum morphology.Further, this study addressed the issue of whether misroutedcortical axons form an aberrant pathway instead of the corpuscallosum. Initial studies that examined fresh brain tissue ofadult animals revealed normal corpora callosa in all ER micebut deficient or absent corpora callosa in all EP mice. Subsequently,Dil crystals were placed in the motor cortices of aldehyde-fixedbrains of 2-week-old animals to investigate cortical projectionsin both inbred substrains of mice. Fluorescent microscopy revealedthat all of the ER animals had normal corpora callosa, whereasall EP animals exhibited either reduced corpora callosa (partiallycallosal) or an absence (acallosal) of this structure. Bothacallosal and partially callosal EP mice displayed an extensive,aberrant projection to the basal forebrain as well as bilateralprojections to midline and intralaminar thalamic nuclei. Thefibers projecting to the basal forebrain arose from the cortex,coursed toward the midline before turning ventrally along themidline, and appeared to terminate in the medial septal nucleusand the nucleus of the diagonal band. ER animals lacked thisaberrant cortical projection to the basal forebrain. Electronmicroscopic results obtained from EP mice indicated that labeledaxons in this aberrant pathway formed axosomatic, axodendritic,and axospinous synapses with the neurons in the medial septal/diagonalband complex. The function of the aberrant projection to thebasal forebrain remains unknown but it may provide an abnormalexcitatory input to a region that provides cholinergic and GABAergicinput to the cerebral cortex and hippocampus. The additionalprojections to midline and contralateral intralaminar thalamicnuclei in EP mice may function to intensify the synchronizationof bilateral discharges.     

Evaluation of the Transverse Sinus by Magnetic Resonance Venography: Limitations-An Illustrative Case Report

Many techniques of magnetic resonance angiography depend on flow velocity. The broad normal range of venous flow velocities and preferential patterns of drainage, particularly in the transverse sinuses, may produce images that are diagnostically misleading. This reports such a case, with samples of various flow patterns in the transverse sinuses of other individuals, as demonstrated by one magnetic resonance angiographic technique (time-of-flight).     

Severe odontogenic infections, part 2: prospective outcomes study.

PURPOSE: The purpose of this study was to identify significant predictors of 4 outcomes in patients with severe odontogenic infections: abscess formation, penicillin therapeutic failure (PTF), length of hospital stay (LOS), and need for reoperation. PATIENTS AND METHODS: We used a prospective case series study design and enrolled 37 consecutive patients admitted for severe odontogenic infection between March 1996 and June 1999. Treatment consisted of intravenous penicillin (PCN) or clindamycin in PCN-allergic patients, surgical incision and drainage, and extraction(s) as soon as possible. Study variables were categorized as demographic, preadmission, time-related, preoperative, anatomic, treatment, microbiologic, and complications. The primary outcome variables were abscess formation, PTF, LOS, and reoperation. Multivariate linear and logistic regression techniques were used to measure associations between study variables and the outcome variables. RESULTS: The sample consisted of 37 subjects (23 male, 14 female) with a mean age of 34.9 +/- 15.8 years. Multivariate analyses, controlling for confounding variables, indicated that culture of Peptostreptococci was a negative predictor of abscess formation. LOS was predicted by the number of infected spaces and duration of operation. There was no significant predictor of PTF or reoperation on multivariate analysis, although PCN-resistant organisms were isolated in all cases of PTF. CONCLUSION: Increased LOS in severe odontogenic infections is predicted by the anatomic extent and severity of the infection and the occurrence of complications such as PTF and the need for reoperation. PTF is significantly associated with later identification of PCN-resistant organisms. The role of Peptostreptococci in abscess formation warrants further investigation.