Brain-derived neurotrophic factor signaling modifies hippocampal gene expression during epileptogenesis in transgenic mice

Brain-derived neurotrophic factor (BDNF) regulates neuronal survival, differentiation and plasticity. It has been shown to promote epileptogenesis and transgenic mice with decreased and increased BDNF signaling show opposite alterations in epileptogenesis. However, the mechanisms of BDNF action are largely unknown. We studied the gene expression changes 12 days after kainic acid-induced status epilepticus in transgenic mice overexpressing either the functional BDNF receptor trkB or a dominant-negative truncated trkB. Epileptogenesis produced marked changes in expression of 27 of 1090 genes. Cluster analysis revealed BDNF signalling-mediated regulation of functional gene classes involved in cellular transport, DNA repair and cell death, including kinesin motor kinesin family member 3A involved in cellular transport. Furthermore, the expression of cytoskeletal and extracellular matrix components, such as tissue inhibitor of metalloproteinase 2 was altered, emphasizing the importance of intracellular transport and interplay between neurons and glia during epileptogenesis. Finally, mice overexpressing the dominant-negative trkB, which were previously shown to have reduced epileptogenesis, showed a decrease in mRNAs of several growth-associated genes, including growth-associated protein 43. Our data suggest that BDNF signaling may partly mediate the development of epilepsy and propose that regrowth or repair processes initiated by status epilepticus and promoted by BDNF signaling may not be as advantageous as previously thought.     

Deletion of the CCK2 receptor gene reduces mechanical sensitivity and abolishes the development of hyperalgesia in mononeuropathic mice

Previous studies suggest that cholecystokinin (CCK) is implicated in the modulation of pain sensitivity and the development of neuropathic pain. We used CCK(2) receptor deficient (CCK(2) (-/-)) mice and assessed their mechanical sensitivity using Von Frey filaments, as well as the development and time course of mechanical hyperalgesia in a model of neuropathic pain. We found that CCK(2) (-/-) mice displayed mechanical hyposensitivity, which was reversed to the level of wild-type animals after administration of naloxone (0.1-10 mg/kg). On the other hand, injection of L-365260 (0.01-1 mg/kg), an antagonist of CCK(2) receptors, decreased dose-dependently, mechanical sensitivity in wild-type mice. The mechanism of reduced mechanical sensitivity in CCK(2) (-/-) mice may be explained by changes in interactions between CCK and opioid systems. Indeed, CCK(2) (-/-) mice natively expressed higher levels of lumbar CCK(1), opioid delta and kappa receptors. Next, we found that CCK(2) (-/-) mice did not develop mechanical hyperalgesia in the Bennett's neuropathic pain model. Induction of neuropathy resulted in decrease of lumbar pro-opiomelanocortin (POMC) gene expression in wild-type mice, but increase of POMC expression in CCK(2) (-/-) mice. In addition, induction of neuropathy resulted in further increase of opioid delta receptor in CCK(2) (-/-) mice. Gene expression results indicate up-regulation of opioid system in CCK(2) (-/-) mice, which apparently result in decreased neuropathy score. Our study suggests that not only pain sensitivity, but also mechanical sensitivity and the development of neuropathic pain are regulated by antagonistic interactions between CCK and opioid systems.     

Regulation of feeding by galnon

Galanin is a neuropeptide that has been implicated in multiple bioactivities, inter alia eating disorders. In this study, we have examined the effects of galnon, a novel low molecular weight galanin receptor ligand. Previous studies have shown that galnon acts as a systemically active, blood-brain barrier crossing agonist on galanin signaling both in vitro and in vivo, inhibiting pentylenetetrazole-induced seizures. Here, intracerebroventricular (10-20 microg) and intraperitoneal (1.5-5 mg/kg) administration of galnon induced a strong, dose-dependent reduction of food intake in rats and mice. This reduction in feeding occurred without reducing general activity and was shown to be attenuated by an intracerebroventricular administration of M35, a peptide galanin antagonist. These data demonstrate that galnon is a promising tool for studies of the involvement of galanin in feeding disorders and other behavioral processes.     

Cancer incidence in multiple sclerosis: a 35-year follow-up

The risk of cancer among multiple sclerosis (MS) patients was evaluated emphasising cancers with a potentially infectious aetiology. Cancer incidence was estimated among incident MS patients in 1964-1993 (n = 1,597) in Finland. The cohort was followed up for cancer incidence through the Finnish Cancer Registry until 1999. A total of 85 cancer cases were diagnosed showing a standardised incidence ratio (SIR) of 1.0 (95% CI 0.8-1.2) for all cancers. The risk (SIR) of haematological tumours was 1.1 and that of central nervous system (CNS) tumours 1.3. The small excess risk of haematological malignancies is consistent with infectious aetiology, whereas the association between MS and CNS tumours may be due to misclassification.     

Use of bioabsorbable osteofixation devices in the hand

Bioabsorbable internal fixation by means of pins, tacks, screws and miniplates offers an alternative to metallic osteofixation for the stabilization of small bone fractures, osteotomies, ligament injuries and fusions in the hand. The advantages of using them include avoidance of metallic-implant-related long-term complications and a secondary removal operation. Currently the most commonly used devices are made of poly L-lactide (PLLA) and copolymers of polylactides (P(L/DL)LA) and polyglycolide (PLGA). In areas of mechanical stress, the use of ultra-high-strength self-reinforced devices is recommended. Biomechanical studies on fresh frozen bones have shown that the fixation rigidity achieved with self-reinforced devices approaches that of metallic osteofixation methods. The reliability of modern implants has been confirmed in several experimental and clinical studies.     

Hepatic toxicity caused by adjuvant CMF/CNF in breast cancer patients and reversal by tamoxifen

The purpose of the study was to determine the effect of adjuvant chemotherapy on liver enzymes in breast cancer patients. Furthermore, the effect of tamoxifen on liver enzymes was analyzed. Liver function tests from 194 breast cancer patients who received adjuvant chemotherapy with or without tamoxifen (TAM) were reviewed. Statistically very significant increases were seen in alkaline phosphatase, aspartate acetyl transferase, and gamma glutamyl transferase levels in these patients receiving adjuvant chemotherapy. No statistical changes were noticed in bilirubin levels. If tamoxifen was given together with adjuvant chemotherapy, no changes in liver function tests were detected. Hepatic toxicity was induced in breast cancer patients by adjuvant CMF/CNF therapy (cyclophosphamide, methotrexate, 5-fluorouracil, mitoxantrone). These changes were mostly mild. Adjuvant tamoxifen reduced the increase in liver enzymes caused by adjuvant chemotherapy.     

Second malignant neoplasms among long-term survivors of Hodgkin's disease: a population-based evaluation over 25 years.

PURPOSE: To quantify the relative and absolute excess risks (AER) of site-specific second cancers, in particular solid tumors, among long-term survivors of Hodgkin's disease (HD) and to assess risks according to age at HD diagnosis, attained age, and time since initial treatment. PATIENTS AND METHODS: Data from 32,591 HD patients (1,111 25-year survivors) reported to 16 population-based cancer registries in North America and Europe (1935 to 1994) were analyzed. RESULTS: Two thousand one hundred fifty-three second cancers (observed-to-expected ratio [O/E] = 2.3; 95% confidence interval [CI] = 2.2 to 2.4), including 1,726 solid tumors (O/E = 2.0; 95% CI, 1.9 to 2.0) were reported. Cancers of the lung (observed [Obs] = 377; O/E = 2.9), digestive tract (Obs = 376; O/E = 1.7), and female breast (Obs = 234; O/E = 2.0) accounted for the largest number of subsequent malignancies. Twenty-five years after HD diagnosis, the actuarial risk of developing a solid tumor was 21.9%. The relative risk of solid neoplasms decreased with increasing age at HD diagnosis, however, patients aged 51 to 60 years at HD diagnosis sustained the highest cancer burden (AER = 79.2/10,000 patients/year). After a progressive rise in relative risk and AER of all solid tumors over time, there was an apparent downturn in risk at 25 years. Temporal trends and treatment group distribution for cancers of the esophagus, stomach, rectum, female breast, bladder, thyroid, and bone/connective tissue were suggestive of a radiogenic effect. CONCLUSION: Significantly increased risks of second cancers were observed in all HD age groups. Although significantly elevated risks of stomach, female breast, and uterine cervix cancers persisted for 25 years, an apparent decrease in relative risk and AER of solid tumors at other sites is suggested.