Interactions between neuroactive steroids and reelin haploinsufficiency in Purkinje cell survival

We determined total Purkinje cell (PC) numbers in cerebella of wild-type (+/+) and heterozygous (rl/+) reeler mice of either sex during early postnatal development; in parallel, we quantified levels of neuroactive steroids in the cerebellum with mass spectrometry. We also quantified reelin mRNA and protein expression with RT-PCR and Western blotting. PC numbers are selectively reduced at postnatal day 15 (P15) in rl/+ males in comparison to +/+ males, +/+ females, and rl/+ females. Administration of 17β-estradiol (17β-E) into the cisterna magna at P5 increases PC numbers in rl/+ males, but not in the other groups; conversely, estrogen antagonists 4-OH-tamoxifen or ICI 182,780 reduce PC numbers in +/+ and rl/+ females, but have no effect in males. Testosterone (T) levels at P5 are much higher in males than in females, reflecting the perinatal testosterone surge in males. In addition, rl/+ male cerebella at P5 show a peculiar hormonal profile in comparison with the other groups, consisting of increased levels of T and 17β-E, and decreased levels of dihydrotestosterone. RT-PCR analysis indicated that heterozygosity leads to a 50% reduction of reelin mRNA in the cerebellum in both sexes, as expected, and that 17β-E upregulates reelin mRNA, particularly in rl/+ males; reelin mRNA upregulation is associated with an increase of all major reelin isoforms. These effects may represent a novel model of how reelin deficiency interacts with variable perinatal levels of neuroactive steroids, leading to gender-dependent differences in genetic vulnerability.     

(±)-α-Methyl-4-carboxyphenylglycine, a metabotropic glutamate receptor blocker, impairs retention of an inhibitory avoidance task in rats when infused into the basolateral nucleus of the amygdala

The amygdala is important for memory processes of emotionally motivated learning and the amygdala glutamatergic system may play a key role in this process. In this study we assessed the effect of the infusion of (±)-α-methyl-4-carboxyphenylglycine (MCPG), a metabotropic glutamate receptor (mGluR) antagonist, into the basolateral complex of the amygdala (BLA) on the learning and retention of an emotionally motivated task. Rats received either vehicle or three different doses of MCPG (0.2, or 1.0, or 5.0 μg/0.2μl/side, respectively) bilaterally into the BLA, 5 min before they were trained in a continuous multiple-trial inhibitory avoidance (CMIA) task. Response latencies during the training were recorded. Retention was assessed 8 days later. MCPG in the doses given did not significantly affect the acquisition of the CMIA task. However, MCPG at a dose of 5.0 μg/0.2 μl/side impaired the long-term retention test performance. Additionally, a nociception test indicated that dose of MCPG infused into the BLA did not affect the footshock sensitivity. Our results indicate that MCPG, when infused into the BLA of rats prior to the training, impaired long-term memory of aversive training without affecting acquisition.     

High doses of laser phototherapy can increase proliferation in melanoma stromal connective tissue

It is well established that laser phototherapy (LP) is contraindicated directly over cancer cells, due to its bio modulatory effects in cell and blood vessel proliferation. The aim of the present study was to analyze the influence of typical low-level laser therapy (LLLT) and high intensity laser therapy (HILT) and an in-between dose of 9 J on collagen fibers and blood vessels content in melanoma tumors (B16F10) implanted in mice. Melanoma tumor cells were injected in male Balb C mice which were distributed in four groups: control (no irradiated) or irradiated by 3, 9, or 21 J (150; 450, or 1050 J/cm²). LP was performed in daily sessions for 3 days with a InGaAlP—660 nm (mean output: 50 mW, spot size: 2 mm²). Tumor volume was analyzed using (1) picrosirius staining to quantify collagen fibers content and (2) Verhoeff’s method to quantify blood vessels content. Tumor growth outcome measured in the 3-J group was not significantly different from controls. Nine and 21-J groups, presented significant and dose-dependent increases in tumor volume. Quantitative analysis of the intensity of collagen fibers and their organization in stroma and peri-tumoral microenvironment showed significant differences between irradiated and control group. Blood vessels count of 21-J group outnumbered the other groups. High doses (≥ 9 J) of LP showed a dose-dependent tumor growth, different collagen fibers characteristics, and eventually blood vessel growth, while a typical LLLT dose (3 J) appeared harmless on melanoma cell activity.     

Fracture resistance and pattern of the upper premolars with obturated canals and restored endodontic occlusal access cavities

We studied whether obturing canals and restoring endodontic occlusal access cavities on upper premolars could provide acceptable resistance and pattern to fracture.Eighteen upper premolars were divided equally into 3 groups.Group 1 consisted of intact controls;group 2 had access cavities and root canal preparations;group 3 as in group 2 but obturated with gutta-percha and AH26,and the access cavity restored with glass ionomer and composite.Specimens were submitted to compressive strength testing using the Hounsfield Universal H50KM testing machine with a load cell of 2000 Newtons and a crosshead speed set at 1.0 mm/min until fracture.The results from the compressive strength tests showed that intact controls （1105.83±90.93 MPa） and restored premolars （936.67±44.67 MPa） were significantly different from premolars with unrestored access cavities 568.33±105.49 MPa.There was no significant difference between intact controls and restored premolars.The predominant fracture pattern for intact teeth was an oblique fracture.For premolars that had endodontic access cavities,restored or unrestored,the most common fracture pattern was a vertical fracture.The restoration of occlusal access cavities with glass ionomer and composite provided fracture resistance close to that of intact controls,but when restored teeth fractured,they were predominantly non-restorable.     

A polysialic acid mimetic peptide promotes functional recovery in a mouse model of spinal cord injury

Contrary to lower species that recapitulate some of the developmental programs, in mammals, functional recovery after spinal cord injury is impaired by a non-permissive environment and the lack of plasticity of adult neurons. The developmental plasticity associated linear homopolymer of alpha 2,8-linked sialic acid (PolySialic Acid, PSA), represents a permissive determinant that could contribute to recovery. We previously showed that a PSA cyclic mimetic peptide (PR-21) displayed PSA-like biological functions (Torregrossa, P., Buhl, L., Bancila, M., Durbec, P., Schafer, C., Schachner, M., Rougon, G., 2004. Selection of poly-alpha 2,8-sialic acid mimotopes from a random phage peptide library and analysis of their bioactivity. J. Biol. Chem. 279, 30707–30714.). In the present study we investigated the therapeutic potential of PR-21 in young adult mice after dorsal hemisection at the T9 level. We show that PR-21 fulfills several criteria for an in vivo use as it is not toxic, not immunogenic and displays good stability in biological fluids or tissue. Delivery of PR-21 to the lesion site decreased the time of the animals' return to continence, and enhanced motor functions, sensorimotor control and coordination of hindlimbs with forelimbs when compared to a control peptide. At the cellular level, PR-21 increased serotonergic axon density at and caudal to the lesion site, and decreased reactive gliosis in vivo. In an in vitro model of reactive astrocytes, PR-21 increased NCAM expression in strongly GFAP positive cells. Our data point to the unique features of a carbohydrate mimicking peptide, and support the notion that PSA can be considered as an important factor in recovery from spinal cord injury.     

Melatonin treatment mimics the antidepressant action in chronic corticosterone‐treated mice

Abstract: Melatonin, involved in circadian cycle, provides protective effects on neuronal cells and acts as antidepressant by restoration of corticosterone levels. A mouse model of anxiety/depressive‐like behavior, induced by chronic corticosterone treatment, has been used to evaluate behavior and adult hippocampal neurogenesis in mice and their possible modulation under melatonin. With this aim, CD1 mice were subjected to 7 wk of corticosterone administration, and then behavioral tests as novelty‐suppressed feeding, open field and a forced swim test were performed. Cell proliferation in hippocampal dentate gyrus (DG) was investigated by 5‐bromo‐2′‐deoxyuridine and doublecortin immunohistochemistry techniques, and stereological procedure was used to quantify labeled cells. Golgi‐impregnated method was used to evaluate the changes of dendritic spines in DG neurons. A new therapeutic approach with antidepressant‐like substances (3 wk) such as melatonin (8 mg/kg) was employed to possibly modulate neural development in the adult hippocampus and the behavioral changes. The depressive‐like state caused by chronic corticosterone treatment was reversed by exogenous administration of melatonin; the proliferation of progenitor cells in mice hippocampus was significantly reduced under chronic corticosterone treatment (cort? 83.7 ± 20.3 versus cort+ 60.5 ± 18.2; P < 0.05), whereas long‐term treatment with melatonin prevented the corticosterone‐induced reduction in hippocampal cell proliferation (cort? 60.5 ± 18.2 versus mel 133.4 ± 26.9; P < 0.05). Corticosterone‐treated mice exhibited a reduced spine density, which was ameliorated by melatonin administration. These findings suggest a strong correspondence between behavior and neurogenesis, strengthening the hypothesis that neurogenesis contributes to the effects of melatonin as an antidepressant.     

Study of peripheral muscle strength and severity indexes in individuals with chronic obstructive pulmonary disease

Background and Purpose. Individuals with chronic obstructive pulmonary disease (COPD) present reduced peripheral muscle strength, which leads to impaired mobility and increased mortality risk. However, it is not clear whether there is any relationship between muscle strength, muscle mass and the body mass index, airflow obstruction, dyspnea, exercise performance (BODE) index scale, which is considered to be the best predictor of survival for individuals with COPD. The BODE Index is a multidimensional system that measures body composition (B), airway obstruction (O), dyspnea perception (D) and the ability to exercise (E), and rates the severity of the major changes found in individuals with COPD. The objective of this study was to verify any relationship between the BODE Index, muscle mass and maximum muscle strengths of the upper limb (UL) and lower limb (LL) in subjects with moderate to very severe COPD. Methods. Twenty‐six individuals with moderate to very severe COPD were evaluated by body composition (body mass index and muscle mass), BODE Index, handgrip strength (HS) and one repetition maximum (1RM) test of the UL and LL. Results. There was a positive correlation (Pearson, p < 0.05) of peripheral muscle strength, evaluated by HS and 1RM (pectoral and triceps, round muscles and dorsal section, quadriceps), to muscle mass (0.74, 0.57, 0.74 and 0.62, respectively) and the distance walked in the six‐minute walking test (0.52, 0.50, 0.46 and 0.58, respectively), but no correlation of muscle strength was found to forced expiratory volume in one second to dyspnea or the BODE Index. Conclusion. In accordance with the results of this study, peripheral muscle strength as measured by HS and 1RM is not related to the severity indexes for COPD, unlike UL and LL muscle strength. Therefore, UL and LL measurements now have an additional importance in COPD evaluation. Copyright © 2010 John Wiley & Sons, Ltd.     

Multilocular cystic renal cell carcinoma: our experience

Multilocular cystic renal cell carcinoma is now recognized as an independent pattern by WHO; it is a rare malignancy with a predominantly cystic growth, characterized by very low oncologic evolution and then susceptible to conservative treatment. In the kidney cystic masses of different origin may arise, i.e. due to malformation, acquired disease or tumor. Renal neoplastic lesions may have a cystic or pseudocystic component. There are also four types of neoplasm with a predominantly cystic growth, including the multilocular cystic carcinoma, which are macroscopically very similar and impossible to differentiate through diagnostic pre-operative images. The Authors present four cases of multilocular cystic renal cell carcinoma diagnosed in the 2000-2007 period, with special reference to diagnostic difficulties and to pre- and intra-operative features of the neoplasm. In conclusion, the extemporaneous histological preoperative diagnosis of multilocular cystic renal cell carcinoma is not possible because it requires extensive sampling; furthermore, the final histological diagnosis sometimes needs particular immunohistochemical procedures to be confirmed.