Antibacterial effects ofin situzinc oxide nanoparticles generated inside the poly (acrylamide-co-hydroxyethylmethacrylate) nanocomposite.

The present work reports the antibacterial activity againstPseudomonasaeruginosaof a nanocomposite made of zinc oxide nanoparticles dispersed in a poly(acrylamide-co-hydroxyethylmethacrylate) matrix (PAAm-Hema-ZnONPs). Thein situsynthesis of ZnONPs inside of the PAAm-Hema crosslinked network is described. Moreover, the physicochemical properties of the PAAm-Hema-ZnONPs nanocomposite are analyzed. The results confirm that the PAAm-Hema hydrogel provides an excellent scaffold to generate ZnONPs. The presence of ZnONPs inside the hydrogel was confirmed by UV-visible (band at 320 nm), by Infrared spectroscopy (peak at 470 cm-1), SEM, and TEM images. The presence of NPs in PAAm-Hema diminish the swelling percentage by 70%, and the Young modulus by 33.7%, compared with pristine hydrogel. The 75% of ZnONPs are released from the nanocomposite after 48 h of spontaneous diffusion, allowing the use of the nanocomposite as an antibacterial agent.In vitro, the agar diffusion test presents an inhibition halo againstP. aeruginosabacteria 50% higher than the unloaded hydrogel. Also, the PAAm-Hema-ZnONPs live/dead test shows 54% of dead cells more than the hydrogel. These results suggest that the easy, one-step way generated composites can be used in biomedical applications as antimicrobial agents.

Effects of 4-aminopyridine on attention and executive functions of patients with multiple sclerosis: Randomized, double-blind, placebo-controlled clinical trial. Preliminary report.

BACKGROUND: A high percentage of patients with multiple sclerosis present cognitive alterations. Because 4-aminopyridine improves nerve conduction and efficient synaptic connection could improve cognitive dysfunction. OBJECTIVE: To evaluate the efficacy on cognitive performance and safety of 4-aminopyridine administered to patients with relapsing-remitting multiple sclerosis. METHODS: A randomized, double-blind, placebo controlled clinical trial was conducted in patients with relapsing-remitting multiple sclerosis diagnosis according to the McDonald criteria. At the beginning and at the end of the treatment different tests were used to assess cognitive performance. Subsequently, patients were randomized 1:1 to receive treatment or placebo. A bootstrap-t test was proposed to test the effectiveness of cognitive performance, considering a p-value < 0.05 as statistically significant. RESULTS: Twenty-four patients were recruited of which 21 completed the trial, 11 with 4-aminopyridine and 10 with placebo treatment. No significant differences between groups in the initial assessments were observed. In terms of efficacy, the experimental group achieved significantly higher scores in attention span, verbal fluency, planning and graphics and constructive motion. CONCLUSIONS: 4-aminopyridine proved to be an effective treatment on cognitive aspects in patients with relapsing-remitting multiple sclerosis. Drug doses were shown to be safe with mild to moderate adverse events (ClinicalTrials.gov number, NCT02280096).

Design of a Reconfigurable Robotic System for Flexoextension Fitted to Hand Fingers Size.

Due to the growing demand for assistance in rehabilitation therapies for hand movements, a robotic system is proposed to mobilize the hand fingers in flexion and extension exercises. The robotic system is composed by four, type slider-crank, mechanisms that have the ability to fit the user fingers length from the index to the little finger, through the adjustment of only one link for each mechanism. The trajectory developed by each mechanism corresponds to the natural flexoextension path of each finger. The amplitude of the rotations for metacarpophalangeal joint (MCP) and proximal interphalangeal joint (PIP) varies from 0 to 90° and the distal interphalangeal joint (DIP) varies from 0 to 60°; the joint rotations are coordinated naturally. The four R-RRT mechanisms orientation allows a 15° abduction movement for index, ring, and little fingers. The kinematic analysis of this mechanism was developed in order to assure that the displacement speed and smooth acceleration into the desired range of motion and the simulation results are presented. The reconfiguration of mechanisms covers about 95% of hand sizes of a group of Mexican adult population. Maximum trajectory tracking error is less than 3% in full range of movement and it can be compensated by the additional rotation of finger joints without injury to the user.

C1272F: a novel type 2A von Willebrand's disease mutation in A1 domain; its clinical significance.

Most mutations identified in 2A VWD patients are localized in the A2 domain, although missense substitutions have also been recognized in the A1 domain. We describe a novel heterozygous missense mutation in the A1 domain of VWF gene responsible for type 2A phenotype. Analysis of the complete exon 28 was carried out in a patient and his mother with life-long histories of moderate to severe bleeding and laboratory data of type 2A VWD. The analysis of exon 28 of VWF gene showed a 3815 G → T transversion resulting in C1272F mutation. It is probably associated with a group I mechanism according to patients' clinical symptoms, and, in the case of the propositus, the lack of clinical response to treatment with desmopressin. The mutation was not found in 100 normal alleles. This substitution affected the normal S-S bound between C1272 and C1458, which is involved in A1 loop structure, altering the normal multimerization and function of VWF. The VWFpp/VWF:Ag ratio in the propositus and his mother was >3, suggesting a shortened survival of VWF. We believe it is important to report the complete clinical phenotype corresponding to the new mutation to increase the knowledge in the clinical field.

[Necrobiotic xanthogranuloma: efficacy of surgery in 2 patients]. / Xantogranuloma necrobiótico: eficacia de la cirugía en dos casos clínicos.

Necrobiotic xanthogranuloma is a rare disease characterized by indurated nodules and yellowish-red plaques in the dermis or subdermal tissues particularly in the periorbital region; the lesions are often ulcerated. This disease is frequently associated with hematological disorders such as monoclonal gammopathy and lymphoproliferative disorders. Its pathogenesis is unknown and the small number of cases makes long-term studies difficult. We present 2 cases of periorbital lesions in which the biopsies established a diagnosis of necrobiotic xanthogranuloma. Both patients were treated with corticosteroids and cyclophosphamide, with no improvement. The lesions were excised and the periorbital regions were reconstructed with skin grafts. After 1 year of follow-up there are no signs of recurrence.

Haemostatic effects of adrenaline-lidocaine subcutaneous infiltration at donor sites.

This study sought methods in burn surgery to reduce postoperative pain and blood loss at donor sites. A prospective, randomised, controlled, blinded trial included 56 people undergoing burn surgery, divided into two groups. Both groups received subcutaneous infiltration at donor sites, with either 1:500,000 adrenaline solution containing added lidocaine or with 0.45% normal saline (controls). Outcome measurements included amount of intraoperative bleeding, need for electrocautery, days the hydrocolloid dressing remained on donor sites, percentage of re-epithelialised skin at donor sites 1 week after surgery and viability of skin grafts. Results indicated that subcutaneous adrenaline-lidocaine infiltration at donor sites reduced intraoperative bleeding, decreased postoperative pain, shortened the duration of surgery and general anaesthesia and accelerated re-epithelialisation at the donor site. The overall graft take in both groups was similar.

EEG changes during word and figure categorization.

OBJECTIVE: To analyze whether the EEG changes observed during figure and word categorization are compatible with either the dual, the common amodal, or the alternative model (modality-specific codes for words and pictures, where meaning is represented for both in a higher-order amodal system) for semantic knowledge. METHODS: EEG was recorded during word and figure categorization of animals or non-animals in a group of 28 children 8-10 years old. Computation of EEG sources in the frequency domain using variable resolution electrical tomography (VARETA) and their statistical evaluation by statistical parametric mapping were carried out. RESULTS: At all frequencies, there were significant changes between EEG segments prior to the presentation of the stimuli and EEG segments recorded after the stimuli. Post-segments showed more power from 1.56 to 7.02 Hz, and less power than pre-segments from 8 to 12.48 Hz. EEG changes were only observed in the word task at: 3.9 (left occipital), 4.68, 5.46, and 6.24 Hz (temporo-occipital regions). These changes may be associated with visual encoding of words. Frequencies 7.8 and 17.94 Hz increased in prefrontal, anterior cingulate, and anterior temporal regions only during figure categorization. The prefrontal region may be related to object working memory. Thus, these frequencies might be related to figure codification. No significant differences between tasks were observed at 3.12 and 7.02 Hz in very wide brain areas (all lobes except occipital), suggesting that the amodal semantic system storage could be the model compatible with figure and word categorization. CONCLUSIONS: Thus, our results support the modified amodal semantic hypothesis, which advocates that the meanings of both kinds of stimuli are represented in a conceptual memory that receives input from the logogen and iconogen systems.

Delayed P300 during Sternberg and color discrimination tasks in poor readers.

The P300 ERP component was studied in poor and normal readers, using Sternberg and color discrimination (Spaceships) tasks. During the first one, subjects must decide if a probe item belongs or not to a set of digits previously presented. In the second one, the participants must shoot violet spaceships with one key and other than violet spaceships with another key. There were no significant differences between groups with respect to reaction times, but a larger proportion of errors was observed in poor readers. Longer P300 latencies were recorded for poor readers than controls in both tasks. P300 amplitudes showed topographical differences between the two groups: Poor readers' P300 is larger frontally during the Sternberg task, but smaller at posterior sites during the Spaceships task. These results suggest that poor readers may have deficiencies during the early processing stage, such as visual stimulus evaluation. Poor readers also appear to have deficits for classifying and memorizing visual stimuli.

Sources of abnormal EEG activity in brain infarctions.

EEGs from 16 patients with stroke in three different stages of evolution were recorded. EEG sources were calculated every 0.39 Hz by frequency domain VARETA. The main source was within the delta band in 2 out of 4 chronic patients, and in 67% of the patients in the acute or subacute stages when edema (cytotoxic or vasogenic) was present. Moreover, all patients showed abnormal activity in the theta band. Sources of abnormal activity in cortical or corticosubcortical infarcts were located in the cortex, surrounding the lesion. At the site of the infarct, a decrease of EEG power was observed. Sources of abnormal theta power coincided with edema and/or ischemic penumbra.

Specific EEG frequencies at specific brain areas and performance.

In this study it was shown that in adults, the frequency characteristics of EEG preceding stimuli that were followed by incorrect responses were different from the characteristics of EEG preceding stimuli that were followed by correct responses. In the recording during three different tasks that explore different neuronal networks, higher values of current preceding incorrect performance in those areas directly related to the task were found in frequencies within the delta (1.56 and 3.12 Hz) and beta bands (13.26, 14.04, 14.82, 15.6, 17.16 and 17.94 Hz), suggesting that these frequencies signal inhibition. Frequencies within the alpha band (9.36 and 12.48 Hz) showed greater energy preceding correct responses in task-specific areas, supporting previous results observed in children.

Primary task demands modulate P3a amplitude.

Auditory event-related brain potentials (ERPs) were recorded from 10 subjects in two different conditions: (1) subjects were required to reorder five visually presented letters in order to form a word and provide a verbal response (task condition); (2) subjects were presented with a control stimulus with the same physical characteristics as the experimental stimulus, but containing just one type of letter (i.e., AAAAA). Subjects had to verbally respond to such stimuli by saying "A" (control condition). Tones of 1000 Hz (standard) and 1050 Hz (deviant) were also presented to the subjects in a 85%-15% probability paradigm 2 s before, during and 8 s after the presentation of the visual stimuli. Recordings were obtained from Fpz, Fz, Cz and Pz vs. linked ears. Auditory ERPs to the auditory stimuli after the presentation of the visual letter string and during the performance of the task were averaged for the standard and deviant tones in both conditions. Only correct responses were considered for the averages. The N100 was affected by stimulus type (standard vs. deviant) but not by condition (task vs. control); however, larger P3a waves were observed during the control than during the task condition. No significant differences between conditions were observed in the mismatch negativity (MMN) latency range. These results suggest that primary task demands modulate involuntary attention processing.

N400 and lexical decisions: automatic or controlled processing?

OBJECTIVE: To investigate whether the N400 effect is sensitive to automatic or controlled processes. METHODS: Two experiments were performed. In one experiment, directly related word pairs were used. In the other experiment, mediated-related word pairs were used. In order to reduce controlled processes, each experiment consisted of 3 tasks: Low- and high-proportion of related pairs, and single presentation lexical decision task. RESULTS: In the first experiment, the amount of priming was equivalent for the 3 tasks. The N400 effect appeared in the high and low proportion of directly related words, but not in the single presentation task. In the second experiment, behavioral priming was also found in the 3 tasks. However, the N400 effect was observed only in the task with low proportion of related pairs. CONCLUSION: These results suggest that the N400 effect may be related to controlled processes.

Enzyme linked immunosorbent assay for potency testing of vaccines containing Clostridium perfringens type D epsilon-toxoid.

For ethical, economic and technical reasons in vivo assays need to be replaced in routine laboratory procedures. Based on a method which is already accepted by the British authorities, an indirect ELISA has been developed and evaluated for Clostridium perfringens type D-containing vaccines. Individual and pooled sera of vaccinated rabbits were tested at a single dilution level, the results transferred into IU/ml, and compared with the conventional toxin neutralization test in mice. The ELISA was found to give reproducible estimates of antitoxin levels and showed good correlation with the conventional in vivo test in mice.

Eficacia y seguridad de ranitidina 150mg vs 300 mg dos veces por día en úlcera duodenal / Effectiveness and safety of ranitidine 150 mg vs 300 mg twice a day in duodenal ulcer

Trescientos noventa y cuatro pacientes con úlcera duodenal diagnosticada endoscópica fueron randomizados para recibir ranitidina 150 mg bid o ranitidina 300 mg bid en un estudio multicéntrico, prospectivo, doble-ciego, llevado a cabo en 7 países latinoamericanos. La endoscopía a las 4 semanas mostró curación completa de las úlceras en 171 de 196 pacientes (87.2%) tratados con ranitidina 150 mg bid y 178 de 198 (89.9%) tratados con ranitidina 300 mg bid. Ambos regímenes de tratamientos fueron igualmente efectivos, reduciendo rápidamente la incidencia de los síntomas ulcerosos. Es probable que el regimen de dosis elevadas con ranitidina sea adecuado en pacientes con enfermedad ulcerosa severa

Eficacia y seguridad de ranitidina 150mg vs 300 mg dos veces por día en úlcera duodenal / Effectiveness and safety of ranitidine 150 mg vs 300 mg twice a day in duodenal ulcer

Trescientos noventa y cuatro pacientes con úlcera duodenal diagnosticada endoscópica fueron randomizados para recibir ranitidina 150 mg bid o ranitidina 300 mg bid en un estudio multicéntrico, prospectivo, doble-ciego, llevado a cabo en 7 países latinoamericanos. La endoscopía a las 4 semanas mostró curación completa de las úlceras en 171 de 196 pacientes (87.2%) tratados con ranitidina 150 mg bid y 178 de 198 (89.9%) tratados con ranitidina 300 mg bid. Ambos regímenes de tratamientos fueron igualmente efectivos, reduciendo rápidamente la incidencia de los síntomas ulcerosos. Es probable que el regimen de dosis elevadas con ranitidina sea adecuado en pacientes con enfermedad ulcerosa severa (AU)

[Effectiveness and safety of 150 mg vs 300 mg ranitidine twice a day in duodenal ulcer]. / Eficacia y seguridad de Ranitidina 150 mg vs 300 mg dos veces por día en ulcera duodenal.

394 patients with endoscopically diagnosed duodenal ulcer were randomly allocated to treatment with ranitidine 150 bid o ranitidine 300 mg bid in a prospective double-blind multicenter trial conducted in seven LatinoAmerican countries. Endoscopy at 4 weeks showed complete ulcer healing en 171 of 196 patients (87.2%) treated with ranitidine 150 mg bid and 178 of 198 (89.9%) treated with ranitidine 300 mg bid. Both treatment regimens were equally effective at rapidly reducing the incidence of ulcer-related symptoms. It is possible that higher dosage regimen of ranitidine would be useful in patients with more severe duodenal ulcer disease.

[Perimeters of the arm and the thorax as indicators of low birth weight]. / Perímetros de brazo y de tórax como indicadores del bajo peso nacimiento.

In a group of 317 newborns, measurements of the perimeter of the arm and the thorax were taken as an indicator of low birth weight. The perimeters of both the arm and the thorax had a high correlation with low birth weight (LBW) (0.88-0.80 respectively). In the sample group, the cut-off point to define low birth weight in the case of perimeter of the arm was 9 cm and was 29-30 cm for perimeter of the thorax. Applying these measurements facilitates early detection and treatment of low birth weight babies who are at risk for infant mortality in situations where it is not possible to weigh the baby at birth.

Eficacia y seguridad de Ranitidina 150 mg vs 300 mg dos veces por día en ulcera duodenal. / [Effectiveness and safety of 150 mg vs 300 mg ranitidine twice a day in duodenal ulcer]

394 patients with endoscopically diagnosed duodenal ulcer were randomly allocated to treatment with ranitidine 150 bid o ranitidine 300 mg bid in a prospective double-blind multicenter trial conducted in seven LatinoAmerican countries. Endoscopy at 4 weeks showed complete ulcer healing en 171 of 196 patients (87.2

) treated with ranitidine 150 mg bid and 178 of 198 (89.9

) treated with ranitidine 300 mg bid. Both treatment regimens were equally effective at rapidly reducing the incidence of ulcer-related symptoms. It is possible that higher dosage regimen of ranitidine would be useful in patients with more severe duodenal ulcer disease.

Estimation of bone turnover in climacteric women by the whole body retention of fluoride.

This paper reports the measurement of whole body retention using fluoride (WBRF) as an estimator of skeletal turnover in a group of climacteric women that received an oral dose of 700 mumol of sodium fluoride. WBRF is defined as 100(1-(urinary fluoride/fluoride load)). WBRF was significantly correlated with whole body retention of 99m-Tc-methylene-diphosphonate, the serum levels of the bone alkaline phosphatase and the urinary excretion of hydroxyproline. WBRF values ranged from 20% to 95% and were affected by calcium intake and the urinary calcium excretion. In normal subjects with high turnover, the measurement of serum alkaline phosphatase activity and/or urinary hydroxyproline excretion helps to distinguish these cases from patients with metabolic bone diseases due to metastases, Paget disease, etc. The fact that the fraction of fluoride not incorporated into bone is not further metabolized plus the accuracy, preciseness and rapidity of fluoride measurements in urine are the main advantages of this technique.