Associative pairing involving monocular stimulation selectively mobilizes a subclass of GABAergic interneurons in the mouse visual cortex

Levels of γ‐aminobutyric acid (GABA) and its synthesizing enzyme in cerebral cortex are regulated by sensory experience. Previously we found that associative pairing of vibrissae stimulation and tail shock results in upregulation of GABAergic markers in the mouse barrel cortex. In order to ascertain whether GABAergic upregulation also accompanies associative pairing in other sensory modalities, we examined the mouse visual cortex after analogous training with visual stimulus. During pairing, visual stimulus (CS) was coupled with a tail shock (UCS). We examined the density of cells expressing glutamic acid decarboxylase (GAD) and parvalbumin (PV) in monocular and binocular segments of the primary visual cortex (V1). The auditory cortex was used as a control. After monocular training, the density of cells expressing GAD rose significantly in the monocular segment of V1 contralateral to the stimulated eye, compared with the opposite hemisphere. This effect was due to the association of CS and UCS, as no changes were found after visual stimulation alone or in the auditory cortex. No changes were noted in the density of PV⁺ neurons, so the effect was attributed to GAD⁺/PV^? neurons. Mobilization of a specific subclass of GABAergic cells, observed after associative pairing in the somatosensory and visual cortices, may reflect the necessity to restrict the activity of circuits involved in sensory association. J. Comp. Neurol. 516:482–492, 2009. © 2009 Wiley‐Liss, Inc.     

OSU-6162, a Sigma1R Ligand in Low Doses,Can Further Increase the Effects of Cocaine Self-Administration on Accumbal D2R Heteroreceptor Complexes

Neurotoxicity Research - Cocaine was previously shown to act at the Sigma1R which is a target for counteracting cocaine actions. It therefore becomes of interest to test if the monoamine stabilizer...     

Value of short exercise and short exercise with cooling tests in the diagnosis of myotonic dystrophies (DM1 AND DM2)

Introduction: Standard electromyography (EMG) is useful in the diagnosis of myotonic dystrophy type 1 (DM1) and type 2 (DM2), but it does not differentiate between them. The aim of this study was to estimate the utility of the short exercise test (SET) and short exercise test with cooling (SETC) in differentiating between DM1 and DM2. Methods: SET and SETC were performed in 32 patients with DM1 (mean age 35.8 ± 12.7 years) and 28 patients with DM2 (mean age 44.5 ± 12.5 years). Results: We observed a significant decline in compound motor action potential (CMAP) amplitude in DM1 with both SET and SETC immediately after effort. In DM2, there was no marked change in CMAP amplitude with either SET or SETC. Conclusions: SET and SETC may serve as useful tools for clinical differentiation between DM1 and DM2, and they may be used as a guide for molecular testing. Muscle Nerve 49 : 277–283, 2014     

Poor-risk high-grade gliomas in three survivors of childhood acute lymphoblastic leukaemia—an overview of causative factors and possible therapeutic options

Purpose  Malignant high-grade gliomas are the most common secondary neoplasms in children cured of acute lymphoblastic leukaemia (ALL). Although many predisposing factors exist (including systemic or intrathecal chemotherapy, young age, brain infiltration and genetic predispositions), cranial irradiation appears to be the strongest one. Methods  Three cases of secondary high-grade gliomas (two multiform glioblastomas, grade IV; one anaplastic astrocytoma, grade III) developed in ALL survivors (F–M, 1:2) 3 to 6.3 years after stopping ALL therapy according to BFM-90 trial. Results  All tumours were supratentorial, contrast-enhancing, space-occupying, highly advanced and aggressive. Possible risk factors and current therapeutic options for paediatric ALL and malignant gliomas are reviewed and discussed. Conclusions  Prognosis in secondary malignant gliomas in children is poor (overall survival of 5, 10 and 19 months) despite intense therapy. Thus, protocols for paediatric ALL reduce prophylactic cranial irradiation in favour of intrathecal and intravenous high-dose MTX. Nevertheless, ALL survivors must undergo systematic, long-term surveillance for early detection of intracranial neoplasms.     

Effect of physicochemical properties of cyclic terpenes on their ex vivo skin absorption and elimination kinetics

BACKGROUND: The terpenes disturb lipid arrangement in the intercellular region of the stratum corneum (SC) that leads to the increased permeability of the skin. This effect is used in technology of transdermal drug forms and depends on physicochemical properties of terpenes and their amounts penetrated to the stratum corneum; however terpenes do not need penetrate into viable skin tissue and this event is not even desired. OBJECTIVE: To correlate skin absorption and elimination kinetics of four cyclic terpenes, namely alpha-pinene, beta-pinene, eucalyptol and terpinen-4-ol, applied as neat substance with their physicochemical properties. METHODS: The terpenes were applied onto the human skin in vitro, and after 1-4 h their content in the separated by a tape-stripping method stratum corneum layers and in the epidermis/dermis was determined using GC. Similarly, the amounts of terpenes in the skin were analysed during 4 h following 1 h absorption. RESULTS: The fastest and progressive penetration into all skin layers was observed for terpinen-4-ol. All studied terpenes are absorbed in the viable epidermis/dermis, however penetration into this layers is time-dependent process, constantly increasing during 4 h. Like for stratum corneum, the largest cumulation in epidermis/dermis was observed for terpinen-4-ol. The elimination of terpenes from the stratum corneum was fast, especially in deeper layers, and much faster if the initial cumulation was small. CONCLUSION: Investigated cyclic terpenes represent different penetration and elimination characteristics and do not permeate across the skin to the acceptor medium due to large cumulation in the skin tissue. The penetration of terpenes into stratum corneum is greater if their log P-value is close to 3.     

Repair of UV dimers in skin DNA of patients with basal cell carcinoma

Epidemiologic studies suggest that exposure to sunlight is the primary etiologic agent for basal cell carcinoma. Formation of UV-induced DNA damage is believed to be a crucial event in the process leading to skin cancer. In this study, repair of photoproducts in DNA was followed in the skin of patients with basal cell carcinoma and control subjects. The subjects were exposed to 800 J/m(2) Commission Internationale de 1'Eclairag of solar-simulating radiation on buttock skin. Biopsies were taken at 0 hour, 24 hours, and 3 weeks after the exposure. Two cyclobutane pyrimidine dimers, TT=C and TT=T, were measured using a sensitive (32)P-postlabeling assay. Initial levels of both TT=C and TT=T differed between individuals in both groups. The levels of TT=T in patients with basal cell carcinoma and controls were similar (9.9 +/- 4.0 and 9.2 +/- 2.9 products per 10(6) normal nucleotides), whereas the level of TT=C was significantly lower in controls than in patients with basal cell carcinoma (6.2 +/- 3.1 versus 10.9 +/- 4.5 products per 10(6) normal nucleotides). The fractions of TT=T remaining after 24 hours and 3 weeks were significantly higher in patients with basal cell carcinoma (72% and 11%) compared with controls (48% and 5%). A slower removal in patients with basal cell carcinoma than in controls was indicated also for TT=C (52% versus 42% remaining at 24 hours); however, the difference between groups was not significant. When including data from our previously reported small-scale study, the fraction of dimers remaining at 24 hours was significantly higher in patients with basal cell carcinoma for both TT=C and TT=T. The data suggest that patients with basal cell carcinoma have a reduced capacity to repair UV-induced DNA lesions.     

Gastric Bypass in Patients with BMI <40 but >32 Without Life-threatening Co-morbidities: Preliminary Report

Background: Surgical intervention is currently indicated for patients with BMI >40 or >35 with life-threatening comorbidities. Patients with BMI 32-40 without these comorbidities not only have the increased propensity to develop them but also suffer from similar psychosocioeconomic consequences. These patients may not respond to non-surgical treatment of obesity any better than those with BMI>40. The question has been raised whether to offer them surgical intervention. Methods: A study was carried out to determine outcome of surgery on patients with BMI >32 but <40 without life-threatening comorbidities but with either psychological, economic or social impairments affecting their quality of life. The approval of our Hospital Internal Review Board was obtained. In addition to routine evaluation for surgical intervention, these patients were required to have the approval of their primary care physician, be seen pre-operatively by a psychiatrist, and have a member of the family or a very close friend present at the time of discussion of operative risks and follow-up requirements. Patients committed to at least a 5-year follow-up. They were to be self-paying patients. The transected silastic ring vertical gastric bypass with a temporary gastrostomy was used. Results: 50 patients, 49 women and one man, were entered into the study between May 1, 1999 and April 30, 2000. 50% were self-pay, and the other 50% were able to obtain coverage through their insurance companies. There were few peri-operative complica tions and no deaths. The late complications include incisional hernias, dumping and transient alopecia. Hospital stay averaged 3.7 days. Follow-up has been 18-27 months. Weight loss has been excellent. Conclusion: Preliminary results of surgical intervention extended to patients with BMI 32-40 without life-threatening comorbidities but with psychosocioeconomic ramifications are very promising. Long term follow-up and comparison with other bariatric patients are planned.     

Inhibitory effect of melatonin on homocysteine-induced lipid peroxidation in rat brain homogenates

Oxidative damage is implicated in several pathologies including cardiovascular disease. As a model system to study the response of cells to oxidative insults, homocysteine toxicity was examined since it is an independent risk factor for atherosclerotic disease. The levels of malondialdehyde and 4-hydroxyalkenals were assayed as an index of oxidatively damaged lipid. In in vitro experiments, the increase of lipid peroxidation products induced by homocysteine were concentration- and time-dependent. To study the protective effect of melatonin on homocystine induced lipid peroxidation, brain homogenates were treated with different concentrations of melatonin. The accumulation of malondialdehyde and 4-hydroxyalkenals induced by homocysteine was significantly reduced by melatonin in a concentration-dependent manner. Additionally, a melatonin concentration of 1.5 mM reduced the levels of oxidatively damaged lipid products below those measured in control homogenates (no homocysteine, no melatonin). These data suggest that melatonin, an endogenous antioxidant may have a role in protecting cells from oxidative damage due to homocysteine and they support the idea that pharmacological concentrations could be used as a therapeutic agent in reducing cardiovascular disease where homocysteine may be a causative or contributing agent.