Functional correlation between cerebellum and basal ganglia: A parkinsonism model.

INTRODUCTION: The cerebellar response has been studied for years with different models of alteration of other brain structures to understand its complex functioning and its relationship with the rest of the body. Studies in patients with Parkinson's disease (PD) showed that the cerebellar function is modified by deficit of the basal ganglia; which supports the hypothesis that both structures are related anatomically and functionally. METHODS: In our study, the ventrolateral striatum (VLS) of the basal ganglia was altered by an electrolytic lesion, in order to produce a similar jaw frequency of jaw tremor movements presented in parkinsonism, thereafter we analyzed the effect of the lesion on the expression of multiunit activity (MUA) of the cerebellum. RESULTS: We found cerebellar activation during mandibular movements and increment during oral jaw tremor movements. In addition, the amplitude of baseline MUA registered in animals with alteration of the VLS decreased with respect to the intact group. CONCLUSIONS: Accordingly, we conclude that cerebellar changes in MUA may be due to a decrease in the cerebellar inflectional or as a possible compensatory function between cerebellum and basal ganglia.

Vitreoretinal lymphoma: a diagnostic challenge.

A 66-year-old man with posterior uveitis and recurrent cystic macular edema related to possible previously treated Lyme disease is presented. Due to the recurrence of macular edema despite systemic and local corticosteroid treatment with intravitreal dexamethasone, biological treatment with Adalimumab was established. During follow-up, the patient developed bilateral subretinal lesions compatible with Vitreoretinal Lymphoma (VRL), so vitrectomy was performed, confirming the diagnosis of large B-cell lymphoma. Treatment with systemic chemotherapy with BRAM-Carmustine, Metrotexate, Ara C, and Rituximab was started with a good answer. Two years later, the patient remains without ocular or systemic recurrences. Vitreoretinal Lymphoma is a rare type of primary central nervous system lymphoma. The diagnosis is frequently delayed due to the nonspecific symptoms, which mimic chronic posterior uveitis, hence the importance with a diagnostic suspicion.

Bactericidal activity of silver nanoparticles in drug-resistant bacteria.

Bacterial resistance to multiple drugs is a worldwide problem that afflicts public health. Various studies have shown that silver nanoparticles are good bactericidal agents against bacteria due to the adherence and penetration of the external bacterial membrane, preventing different vital functions and subsequently bacterial cell death. A systematic review of ScienceDirect, PubMed, and EBSCOhost was conducted to synthesize the literature evidence on the association between the bactericidal property of silver nanoparticles on both resistant Gram-positive and Gram-negative bacteria. Eligible studies were original, comparative observational studies that reported results on drug-resistant bacteria. Two independent reviewers extracted the relevant information. Out of the initial 1 420, 142 studies met the inclusion criteria and were included to form the basis of the analysis. Full-text screening led to the selection of 6 articles for review. The results of this systematic review showed that silver nanoparticles act primarily as bacteriostatic agents and subsequently as bactericides, both in Gram-positive and Gram-negative drug-resistant bacteria.

Monte Carlo calculation of charge collection efficiencies in ionization chambers.

Collection efficiency is an important quantity in dosimetry with ionization chambers. It can be calculated by solving a hyperbolic system of partial differential equations. This system can be solved only in few, simple, idealized geometries, but for more realistic designs an analytical resolution is no longer possible. In the present work a Monte Carlo scheme that could permit to calculate the collection efficiency for any ionization chamber geometry is proposed. This scheme has been tested against Boag's approach for three chambers with plane-parallel, cylindrical and spherical geometries, operated in the recombination regime. The results obtained in the full Monte Carlo simulation closely agree with the Boag's ones for the three ideal geometries considered. The largest relative difference, ∼0.3%, has been found for the plane-parallel chamber in case of 50 V, the lowest potential difference investigated in this study. Results appear to be stable against changes in the chamber volume, the ion mobility and the recombination constant. The method proposed could be a useful tool to calculate collection efficiencies of ionization chambers, provided the electric field inside them is known.

Repeated stereotactic radiosurgery for recurrent brain metastases: An effective strategy to control intracranial oligometastatic disease.

Due to improvements in systemic therapies and longer survivals, cancer patients frequently present with recurrent brain metastases (BM). The optimal therapeutic strategies for limited brain relapse remain undefined. We analyzed tumor control and survival in patients treated with salvage focal radiotherapy in our center. Thirty-three patients with 112 BM received salvage stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSRT) for local or regional recurrences. Local progression was observed in 11 BM (9.8 %). After 1 year, 72 % of patients were free of distant brain failure, and the 2-year overall survival (OS) was 37.7 %. No increase in toxicity or neurologically related deaths were observed. The 2- and 3-year whole brain radiation therapy free survival (WFS) rates were 92.9 % and 77.4 %, respectively. Hence, focal radiotherapy is a feasible salvage of recurrent BM in selected group of patients with limited brain disease, achieving a maintained intracranial control and less neurological toxicity.

New criteria to determine the destabilization of the acidogenic anaerobic co-digestion of organic fraction of municipal solid waste (OFMSW) with mixed sludge (MS).

Effect of hydraulic retention time (HRT) on bio-hydrogen production from co-digestion of organic fraction of municipal solid waste (OFMSW) and mixed sludge (MS) in dry thermophilic conditions (55°C and 20% total solids) was investigated. A decreasing sequence of six HRTs, from 2.9 to 0.8-days, was performed to evaluate the stability of the system and the influence of HRT on the organic matter solubilization, the daily hydrogen production (HP) and the specific hydrogen production (SHP). Best results were obtained operating at 1.2-days HRT: HP of 3.67L H2/Lreactor/day, SHP of 33.8mL H2/gVSadded and hydrogen percentage in biogas of 52.4%. However, HRTs lower than 1.2-days induce failure in the system due to an unbalance of the hydrolytic phase. This fact was corroborated through the evaluation of two indirect parameters, "non-solubilized carbon" (NSC) and "acidogenic substrate as carbon" (ASC), and the relationships of NSC/TOC and ASC/TOC.

Olfactory conditioned same-sex partner preference in female rats: Role of ovarian hormones.

The dopamine D2-type receptor agonist quinpirole (QNP) facilitates the development of conditioned same-sex partner preference in males during cohabitation, but not in ovariectomized (OVX) females, primed with estradiol benzoate (EB) and progesterone (P). Herein we tested the effects of QNP on OVX, EB-only primed females. Females received a systemic injection (every four days) of either saline (Saline-conditioned) or QNP (QNP-conditioned) and then cohabited for 24h with lemon-scented stimulus females (CS+), during three trials. In test 1 (female-female) preference was QNP-free, and females chose between the CS+ female and a novel female. In test 2 (male-female) they chose between the CS+ female and a sexually experienced male. In test 1 Saline-conditioned females displayed more hops & darts towards the novel female, but QNP-conditioned females displayed more sexual solicitations towards the CS+ female. In test 2 Saline-conditioned females displayed a clear preference for the male, whereas QNP-conditioned females displayed what we considered a bisexual preference. We discuss the effect of dopamine and ovarian hormones on the development of olfactory conditioned same-sex preference in females.

Influence of total solids concentration on the anaerobic co-digestion of sugar beet by-products and livestock manures.

A series of batch anaerobic digestion assays were implemented to determine the influence of total solids concentration on the anaerobic digestion of sugar beet by-products and their co-digestion with two kind of livestock manures (pig and cow manures). The two total solid concentrations studied were 8% and 5%. Total solids contents above 8% were not evaluated because of the inappropriate rheological behaviour of sugar beet by-products at these concentrations. The best total solid content tested corresponded to 8%, achieving specific methane yields of 464.3 and 451.4mL/g VSadded for co-digestion with pig manure and cow manure respectively. These data were 1.5 times higher than that obtained for reactors operating with 5% total solids content. For individual digestion of sugar beet by-products, final methane yields operating at 8% were also higher than those measured at 5% total solids concentration. However, in these tests, a large delay in the start of biogas production was registered due to the inhibition caused by the accumulation of volatile fatty acids. No significant differences in the organic matter removal efficiencies were observed for the two total solids contents studied.

Effect of electrolytic lesion of the dorsomedial striatum on sexual behaviour and locomotor activity in rats. / Efecto de la lesión electrolítica del estriado dorsomedial sobre la conducta sexual y actividad locomotora de la rata.

INTRODUCTION: Cortical motor areas are influenced not only by peripheral sensory afferents and prefrontal association areas, but also by the basal ganglia, specifically the striatum. The dorsomedial striatum (DMS) and dorsolateral striatum are involved in both spatial and stimulus-response learning; however, each of these areas may mediate different components of learning. The aim of the study is to determine the effect of electrolytic lesion to the DMS on the learning and performance of sexual behaviour and locomotor activity in male rats. METHOD: Once the subjects had learned to perform motor tests of balance, maze navigation, ramp ascent, and sexual behaviour, they underwent electrolytic lesion to the DMS. Five days later, the tests were repeated on 2 occasions and researchers compared performance latencies for each test. RESULTS: Average latency values for performance on the maze and balance tests were higher after the lesion. However, the average values for the ramp test and for sexual behaviour did not differ between groups. CONCLUSIONS: Electrolytic lesion of the DMS modifies the performance of locomotor activity (maze test and balance), but not of sexual behaviour.

Effect of copulation on potentially precancerous prostate lesions, serum testosterone and prolactin levels in rats.

UNLABELLED: The prostate is an exocrine reproductive gland that participates in ejaculation and it is prone to diseases, including cancer. AIM: In the pre-sent study, we assessed the long-term effects of copulation on the development of precancerous lesions in rats, and compared them with testosterone-induced prostatic lesions. MATERIALS AND METHODS: One group of Wistar males was given 10 copulatory sessions to one ejaculation with ovariectomized, hormone-primed females. Sessions occurred twice per week for a total of ten trials. A second group was exposed to females during the same trials, but physical contact was prevented. In addition, each group received a subcutaneous implant in the back either filled with testosterone propionate (T, 100 mg/kg) or empty. This resulted in four subgroups: 1) Control + No sex, 2) Control + Sex, 3) T + No sex and 4) T + Sex. Two days after the 10(th) trial all the males were sacrificed for prostate histo-logy (H&E) and hormone analysis (testosterone and prolactin). RESULTS: Males from the group Control + No sex expressed normal histo-logy. However, those in the groups Control + Sex and T + No sex expressed metaplasia and dysplasia in both the dorsolateral and ventral portions of the prostate, respectively. Interestingly, males from the group T + Sex expressed dysplasia in the dorsolateral prostate only, but not in the ventral prostate. CONCLUSIONS: These results indicate that constant copulation may facilitate the development of prostatic lesions in males with normal levels of testosterone. However, copulation induces less lesions in the ventral prostate of males treated with testosterone.

Effects on locomotion and memory in 2 models of cerebral hypoperfusion in male Wistar rats.

INTRODUCTION: Cerebral ischaemia is one of the most common neurological diseases worldwide. Its many sequelae range from motor and sensory symptoms to cognitive decline and dementia. Animal models of cerebral ischaemia/hypoperfusion elicit effects on long term memory; however, the effects of these procedures on short term memory are not clearly understood and effects induced by alternative hypoperfusion models are completely unknown. METHODS: We evaluated the effects of 2 cerebral hyperperfusion models on memory in 3-month-old male rats. Episodic memory and working memory were assessed using the new object recognition test and the spontaneous alteration test, respectively. Neurological assessment was also performed, along with an open field test to evaluate locomotor activity. RESULTS: Rats in both hyperperfusion models displayed no cognitive changes. Rats with unilateral left-sided ligation plus temporary ligation of the right carotid tended to show slightly impaired performance on the new object recognition test on the second day after the procedure. In contrast, the group with permanent unilateral ligation tended to display alterations in working and episodic memory 9 days after the procedure, but they subsequently recovered. CONCLUSION: Despite these differences, both hypoperfusion groups displayed clear signs of motor impairment 2 days after the procedure, as reflected by their decreased locomotor activity during the open field test.

Activation of the cerebellum by olfactory stimulation in sexually naive male rats.

INTRODUCTION: The cerebellum has been linked to multiple functions, such as motor control, cognition, memory, and emotional processing. As for its involvement in the sensory systems, the role of the cerebellum in the sense of smell remains unclear. We suggest that sexually naive male rats will present increased neuronal activity in the cerebellar vermis after being stimulated with almond odour or oestrous odour from receptive females. METHODS: We compared activity in the cerebellar vermis using Fos immunoreactivity after olfactory stimulation. Stimulation took place during 60 min in a cube-shaped acrylic chamber with a double bottom. Stimuli were clean woodchip bedding, bedding with almond extract, and bedding taken from a cage of receptive females. Male rats were subsequently anaesthetised with intraperitoneal sodium pentobarbital. Cerebellar tissue was fixed with paraformaldehyde for later immunohistochemical analysis. RESULTS: The number of Fos immunoreactive cells in all lobes of the cerebellar vermis was similar between groups stimulated with almond extract and with oestrous odour, and higher than in the clean woodchip group. CONCLUSIONS: Stimulation of the main olfactory system (almond) and the accessory system (oestrous odour) increases Fos protein production in the granular layer of the cortex of the cerebellar vermis in naive male rats.

Enhancement in hydrogen production by thermophilic anaerobic co-digestion of organic fraction of municipal solid waste and sewage sludge--optimization of treatment conditions.

Batch dry-thermophilic anaerobic co-digestion (55°C) of organic fraction of municipal solid waste (OFMSW) and sewage sludge (SS) for hydrogen production was studied under several sludge combinations (primary sludge, PS; waste activated sludge, WAS; and mixed sludge, MS), TS concentrations (10-25%) and mixing ratios of OFMSW and SS (1:1, 2.5:1, 5:1, 10:1). The co-digestion of OFMSW and SS showed a 70% improvement in hydrogen production rate over the OFMSW fermentation only. The co-digestion of OFMSW with MS showed 47% and 115% higher hydrogen production potential as compared with OFMSW+PS and OFMSW+WAS, respectively. The maximum hydrogen yield of 51 mL H2/g VS consumed was observed at TS concentration of 20% and OFMSW to MS mixing ratio of 5:1, respectively. The acetic and butyric acids were the main acids in VFAs evolution; however, the higher butyric acid evolution indicated that the H2 fermentation was butyrate type fermentation.

Beyond the basal ganglia: cFOS expression in the cerebellum in response to acute and chronic dopaminergic alterations.

The suggestion of an anatomical and functional relationship between the basal ganglia and cerebellum is recent. Traditionally, these structures were considered as neuronal circuits working separately to organize and control goal-directed movements and cognitive functions. However, several studies in rodents and primates have described an anatomical interaction between cortico-basal and cortico-cerebellar networks. Most importantly, functional changes have been observed in one of these circuits when altering the other one. In this context, we aimed to accomplish an extensive description of cerebellar activation patterns using cFOS expression (cFOS-IR) after acute and chronic manipulation of dopaminergic activity. In the acute study, substantia nigra pars compacta (SNc) activity was stimulated or suppressed by intra cerebral administration of picrotoxin or lidocaine, respectively. In addition, we analyzed cerebellar activity after the induction of a parkinsonism model, the tremulous jaw movements. In this model, tremulous jaw movements were induced in male rats by IP chronic administration of the dopamine antagonist haloperidol (1.5mg/kg). Acute stimulation of SNc by picrotoxin increased cFOS-IR in the vermis and cerebellar hemispheres. However, lidocaine did not produce an effect. After 14days of haloperidol treatment, the vermis and cerebellar hemispheres showed an opposite regulation of cFOS expression. Chronic dopaminergic antagonism lessened cFOS expression in the vermis but up-regulated such expression in the cerebellar hemisphere. Overall, the present data indicate a very close functional relationship between the basal ganglia and the cerebellum and they may allow a better understanding of disorders in which there are dopamine alterations.

Induction of mandibular tremor using electrolytic lesion of the ventrolateral striatum or using subchronic haloperidol therapy in male rats: an electromyographic comparison.

INTRODUCTION: Tremulous jaw movement (TJMs) in rats can be induced pharmacologically by striatal dopaminergic manipulation or electrolytic lesion of ventrolateral striatum (VLS). This tremor has neurochemical, anatomical and electromyographic (EMG) characteristics similar to those of tremor in Parkinson patients. However, the EMG characteristics of tremors generated by electrolytic lesion to the VLS have not yet been studied. METHOD: This study used electromyography to describe tremulous jaw movement generated by bilateral electrolytic lesion in the VLS and compare it to tremors induced using subchronic IP treatment with haloperidol, a dopaminergic D2 receptor antagonist. The experimental groups contained rats with a lesion in the ventrolateral striatum and rats on subchronic haloperidol treatment; the control group received only the vehicle. The EMG signal from the temporal muscle was recorded at baseline and during TJMs in all groups. RESULTS: TMJ frequencies were heterogeneous among the groups. Rats with VLS lesion showed higher amplitude and frequency values than the haloperidol-treated rats. Amplitudes at baseline also differed among the groups. CONCLUSIONS: We conclude that TMJs associated with electrolytic lesion to the VLS show a higher frequency and amplitude than tremors induced by haloperidol. This may be related to the way striatum neurons are affected.

New strategy for a suitable fast stabilization of the biomethanization performance.

The start-up strategies for thermophilic anaerobic reactors usually consist of an initial mesophilic stage (35°C), with an approximate duration of 185 days, and a subsequent thermophilic stage (55°C), which normally requires around 60 days to achieve the system stabilizatio. During the first 8-10 days of the mesophilic stage, the reactor is not fed so that the inoculum, which is generally a mesophilic anaerobic sludge, may be adapted to the organic solid waste. Between mesophilic and thermophilic conditions the reactor is still not fed in an effort to prevent possible imbalances in the proces. As a consequence, the start-up and stabilization of the biomethanization performance described in the literature require, at least, around 245 days. In this sense, a new strategy for the start-up and stabilization phases is presented in this study. This approach allows an important reduction in the overall time necessary for these stages in an anaerobic continuous stirred tank reactor (CSTR) operated at thermophilic-dry conditions for treating the organic fraction of the municipal solid waste (OFMSW): 60 days versus 245 days of conventional strategies. The new strategy uses modified SEBAC technology to adapt an inoculum to the OFMSW and the operational conditions prior to seeding the CSTR.

Dry-thermophilic anaerobic digestion of organic fraction of municipal solid waste: methane production modeling.

The influence of particle size and organic matter content of organic fraction of municipal solid waste (OFMSW) in the overall kinetics of dry (30% total solids) thermophilic (55°C) anaerobic digestion have been studied in a semi-continuous stirred tank reactor (SSTR). Two types of wastes were used: synthetic OFMSW (average particle size of 1mm; 0.71 g Volatile Solids/g waste), and OFMSW coming from a composting full scale plant (average particle size of 30 mm; 0.16 g Volatile Solids/g waste). A modification of a widely-validated product-generation kinetic model has been proposed. Results obtained from the modified-model parameterization at steady-state (that include new kinetic parameters as K, Y(pMAX) and θ(MIN)) indicate that the features of the feedstock strongly influence the kinetics of the process. The overall specific growth rate of microorganisms (µ(max)) with synthetic OFMSW is 43% higher compared to OFMSW coming from a composting full scale plant: 0.238 d(-1) (K=1.391 d(-1); Y(pMAX)=1.167 L CH(4)/gDOC(c); θ(MIN)=7.924 days) vs. 0.135 d(-1) (K=1.282 d(-1); Y(pMAX)=1.150 L CH(4)/gDOC(c); θ(MIN)=9.997 days) respectively. Finally, it could be emphasized that the validation of proposed modified-model has been performed successfully by means of the simulation of non-steady state data for the different SRTs tested with each waste.

Dry-thermophilic anaerobic digestion of simulated organic fraction of municipal solid waste: process modeling.

Solid retention time (SRT) is a very important operational variable in continuous and semicontinuous waste treatment processes since the organic matter removal efficiency--expressed in terms of percentage of Dissolved Organic Carbon (% DOC) or Volatile Solids (% VS) removed--and the biogas or methane production are closely related with the SRT imposed. Optimum SRT is depending on the waste characteristics and the microorganisms involved in the process and, hence, it should be determined specifically in each case. In this work a series of experiments were carried out to determine the effect of SRT, from 40 to 8 days, on the performance of the dry (30% Total Solids) thermophilic (55°C) anaerobic digestion of organic fraction of Municipal Solid Wastes (OFMSW) operating at semicontinuous regime of feeding. The experimental results show than 15days is the optimum SRT (the best between all proved) for this process. Besides, data of organic matter concentration and methane production versus SRT have been used to obtain the kinetic parameters of the kinetic model of Romero García (1991): the maximum specific growth rate of the microorganisms (µmax=0.580 days(-1)) and the fraction of substrate non-biodegradable (α=0.268).

Start-up of thermophilic-dry anaerobic digestion of OFMSW using adapted modified SEBAC inoculum.

The work presented here concerns the start-up and stabilization stages of a Continuous Stirred Tank Reactor (CSTR) semicontinuously fed for the treatment of the Organic Fraction of Municipal Solid Waste (OFMSW) through anaerobic digestion at thermophilic temperature range (55 degrees C) and dry conditions (30% Total Solids). The procedure reported involves two novel aspects with respect to other start-up and stabilization protocols reported in the literature. The novel aspects concern the adaptation of the inoculum to both the operating conditions (thermophilic and dry) and to the type of waste by employing a modified SEBAC (Sequential Batch Anaerobic Composting) system and, secondly, the direct start-up of the process in a thermophilic temperature regime and feeding of the system from the first day of operation. In this way a significant reduction in the start-up time and stabilization is achieved i.e. 110 days in comparison to 250 days for the processes reported by other authors for the same type of waste and digester. The system presents suitable operational conditions to stabilize the reactor at SRT of 35 days, with a maximum biogas production of 1.944 LR/L.d with a CH(4) and CO(2) percentage of 25.27% and 68.15%, respectively.

Effect of the pH influent conditions in fixed-film reactors for anaerobic thermophilic treatment of wine-distillery wastewater.

In anaerobic treatments, the pH conditions affect the efficacy and operation of the process. The main purpose of this research is to compare the effect of the pH influent on the performance of a high rate technology at laboratory scale, upflow anaerobic fixed-film reactor, treating distillery wastewater (wine vinasses) in thermophilic conditions. The results obtained shown that the pH influent influences the performance of the biodegradation process: the depurative efficiency is higher for the operation with alkaline influent. The operation with acid influent allows us to operate at organic loading rates (OLR) around 5.6 kgCOD/m3/d (hydraulic retention time: 1.5 days), maintaining total Chemical Oxygen Demand removals (CODr) of 77.2%; the operation with alkaline influent allows total CODr of 76.8% working at OLR around 10.5 kgCOD/m3/d. The greatest efficiency of substrate removal was 87.5% for OLR 3.2 kgCOD/m3/d and hydraulic retention time of 4.0 days operating with alkaline influent. Therefore, the operation with alkaline influent implicates senior levels of purifying efficiency for similar organic load rate.