Two-component models of reaching: evidence from deafferentation in a Fitts' law task

Both feedforward and feedback mechanisms are used to ensure accurate movements. Feedback information comes primarily from vision and proprioception; the relative contributions of these modalities to on-line control of action and internal model maintenance remain unclear. We report data from an experiment in which a chronically deafferented subject (JDY) and nine controls were asked to reach to targets of different sizes both with and without vision. Movement times of controls were consistent with Fitts' law on trials with and without vision. JDY's movement times were consistent with Fitts' law only with vision. She was inaccurate relative to controls with vision but exhibited a significantly greater decrement in performance than controls without vision. Finally, JDY's performance on trials with vision deteriorated as a function of the number of preceding trials on which vision was not available. These data provide support for classical models of motor control that divide reaching into an initial ballistic movement guided by efference copy, and a terminal stage where sensory feedback is crucial. Furthermore, these data also demonstrate that proprioception is needed to calibrate and maintain internal models of action.

Phantom tactile sensations modulated by body position

Bilateral activation of somatosensory areas after unilateral stimulation is assumed to be mediated by crosshemispheric connections. Despite evidence of bilateral activity in response to unilateral stimulation, neurologically intact humans do not experience bilateral percepts when stimulated on one side of the body. This may be due to active suppression of ipsilateral neural activity by inhibitory mechanisms whose functioning is poorly understood. We describe an individual with left fronto-parietal damage who experiences bilateral sensations in response to unilateral tactile stimulation-a rarely reported condition known as synchiria (previously described in visual, auditory, and somatosensory modalities). Presumably, the phantom sensations result from normal bilateral crosshemispheric activation, combined with a failure of inhibitory mechanisms to prevent bilateral perceptual experiences. Disruption of these mechanisms provides a valuable opportunity to examine their internal functioning. We find that the synchiria rate is affected by hand position relative to multiple reference frames. Specifically, synchiria decreases as the hands move from right (contralesional) to left (ipsilesional) space in trunk- and head-centered reference frames and disappears when the hands are crossed. These findings provide novel evidence that mechanisms that inhibit bilateral percepts operate in multiple reference frames.

Review article: pharmacological therapy for hepatocellular carcinoma with sorafenib and other oral agents

BACKGROUND

Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide. Unresectable disease patients have median survival of few months. There is a substantial need for novel treatments for patients with advanced HCC.

AIM

To provide an update review of mechanism of hepatocarcinigenesis and systemic therapies for HCC and the relevant role of Sorafenib in patients with advanced disease.

METHODS

A Medline search was performed to identify pertinent original research and review articles. Selected references in these articles were also evaluated.

RESULTS

Systemic chemotherapy for HCC has been quite ineffective. Preclinical studies demonstrated that Raf/MAPK-ERK kinase (MEK)/Extracellular signal regulated kinase (ERK) pathway has a role in HCC. HCC tumours are highly vascularized and vascular endothelial growth factor (VEGF) augments HCC development and metastasis. Sorafenib blocks tumour cell proliferation by targeting Raf/MEK/ERK signalling and exerts an antiangiogenic effect by targeting VEGF receptors-2/3 and platelet derived growth factor receptor beta tyrosine kinases.

CONCLUSIONS

Currently available therapies are not effective for patients with advanced HCC. Sorafenib has demonstrated for the first time to prolong survival in patients with advanced HCC, and it is the new reference standard for systemic treatment in these patients.

[The upper limb of children with cerebral palsy: surgical aspects]

Cerebral palsy has a complex and multifactorial etiology. The management of the upper limb aims to improve function, hygiene and cosmesis in many patients. Surgical treatment need a good and repeated clinical examination before. The functional surgery has a lot of procedures on the elbow, the wrist, the fingers and the thumb. These procedures include the release or lengthening of spastic muscles, tendon transfers and joint stabilizations. The surgeon must know the indications and contraindications of functional surgery.

Raman spectroscopy of the system iron(III)-sulfuric acid-water: an approach to Tinto River's (Spain) hydrogeochemistry

Acid mine drainage is formed when pyrite (FeS(2)) is exposed and reacts with air and water to form sulfuric acid and dissolved iron. Tinto River (Huelva, Spain) is an example of this phenomenon. In this study, Raman spectroscopy has been used to investigate the speciation of the system iron(III)-sulfuric acid-water as an approach to Tinto River's aqueous solutions. The molalities of sulfuric acid (0.09 mol/kg) and iron(III) (0.01-1.5 mol/kg) were chosen to mimic the concentration of the species in Tinto River waters. Raman spectra of the solutions reveal a strong iron(III)-sulfate inner-sphere interaction through the nu(1) sulfate band at 981 cm(-1) and its shoulder at 1005 cm(-1). Iron(III)-sulfate interaction may also be facilitated by hydrogen bonds and monitored in the Raman spectra through the symmetric stretching band of bisulfate at 1052 cm(-1) and a shoulder at 1040 cm(-1). Other bands in the low-frequency region of the Raman spectra are attributed to the hydrogen-bonded complexes formation as well.

Clinical and pathological characteristics and response to combination therapy of genotype 4 chronic hepatitis C patients: experience from a spanish center

This observational study evaluated the characteristics of genotype 4 chronic hepatitis C (CHC) patients and their response to combination therapy in Spain. 383 patients with CHC, 44 with genotype 4-HCV infection, were investigated. Nineteen genotype 4-HCV infected patients received IFNalpha-2b (3 MU three times weekly) plus ribavirin (1-1.2 g/day) and ten received Peg-IFNalpha-2b (1.5 microg/kg/week) plus ribavirin (1-1.2 g/day) for 12 months. A sustained virological response (SVR) was evaluated. Genotype 4-HCV was detected in 11.5% of patients, and was significantly associated with a higher proportion of infection through intravenous drug use (46% vs 11%; p<0.001), a higher alcohol intake (35% vs. 7%; p<0.001), higher proportion of anti-HBc positivity (41% vs. 22%; p<0.05), lower ALT (87+/-50 vs. 139+/-142 IU/L; p<0.001) and AST (53+/-30 vs. 85+/-126 IU/L; p<0.001) levels, lower viremia (4.1 +/- 7.7 (x 10(5)) vs . 7.3 +/- 9.8 IU(x 10(5) )/mL) p<0.05) and less fibrosis (stage 3-4 in 21% vs. 32%; p<0.06). Sixteen (55%) out of the 29 patients treated with combination therapy achieved a sustained virological response (SVR) while 10 (36%) were non-responders and 3 (9% relapsed. In conclusion, the lower stage of fibrosis, lower viremia and higher SVR rate than genotype 1 suggest a less aggressive pattern of diseased caused by this genotype.

The effect of supplementation with n-3 fatty acids on the physical performance in subjects with spinal cord injury

A global physical evaluation was performed in 21 males with spinal cord injury (SCI), at the beginning and at three and six months of omega-3 fatty acid (FA) supplementation. A significant increase in the proportion of eicosapentaenoic acid and docosahexanoic acid in plasma was observed in response to the supplementation (p<0.05). After six months of FA supplementation, strength endurance time increased from 127.7+/-19.0 s to 215.2+/-45.6 s in the right arm, and from 139+/-27.6 s to 237.7+/-48.7 s, in the left arm. The time to perform 20 repetitions of 70% maximum workload showed a reduction of 41% between the first and the third test. The time taken to cover a 90 meter long track, with a 6% slope, was reduced from 66.9+/-8.0 s to 59.3+/-6.7 s, at the end of the study (p<0.05). In conclusion, omega-3 FA supplementation could contribute to improve the functional capabilities in SCI subjects.

Prevalence, duration and aetiology of bacteraemia following dental extractions

OBJECTIVE

To investigate the prevalence, duration and aetiology of bacteraemia following dental extractions, analysing the factors affecting its development.

SUBJECTS AND METHODS

The study group was composed of 53 patients undergoing dental extractions under general anaesthesia. Peripheral venous blood samples were collected at baseline and at 30 s, 15 min and 1 h after the dental extractions. Samples were inoculated into BACTEC PLUS aerobic and anaerobic blood culture bottles and were processed in Bactec 9240. Subculture and further identification of the bacteria isolated was performed by conventional microbiological techniques.

RESULTS

The prevalence of bacteraemia following dental extractions was 96.2% at 30 s, 64.2% at 15 min and 20% at 1 h after completing the surgical procedure. The bacteria most frequently identified in the positive blood cultures were Streptococcus spp. (63.8%), particularly Streptococcus viridans.

CONCLUSIONS

In our series, the majority of patients undergoing dental extractions developed bacteraemia, usually of a streptococcal nature, independently of the grade of oral health and of the number of extractions performed. Positive blood cultures persisted for at least 1 h after the dental procedure in a considerable number of patients, questioning the supposedly transient nature of bacteraemia following dental extractions.

Association between angiogenesis soluble factors and disease progression markers in chronic hepatitis C patients

OBJECTIVES

Our objectives were to compare angiogenesis soluble factor (ASF) levels in chronic hepatitis C (CHC) patients and healthy individuals, and to investigate potential associations between ASF levels and both histological and biochemical markers of disease progression.

METHOD

Thirty-six patients (69% males) positive for HCV-RNA by PCR analysis were included in the study. All patients underwent liver biopsy before treatment. Serum levels of vascular endothelial growth factor (VEGF), soluble Flt-1 and Flk-1 receptors, placental growth factor (PlGF), angiopoietin-2 (Ang-2) and soluble Tie-2 receptor were determined by ELISA. Fifteen healthy subjects were used as controls.

RESULTS

In comparison to healthy individuals, CHC patients showed significantly increased serum levels of proangiogenic factors PlGF (22 +/- 5 vs. 18 +/- 8 pg/ml; p < 0.05), Ang-2 (1265 +/- 385 vs. 833 +/- 346 pg/ml; p < 0.005) and sFlt-1 (95 +/- 22 vs. 72 +/- 14 pg/ml; p < 0.0001). Interestingly, in CHC patients serum levels of VEGF and Tie-2 correlated with grade of inflammation, PlGF correlated with stage of fibrosis, and Flt-1 and Flk-1 correlated with serum transaminase levels (p < 0.05 in all cases).

CONCLUSIONS

CHC patients showed increased serum levels of ASF, and a significant correlation was shown between serum levels of selected ASFs and grade of inflammation, stage of fibrosis, and transaminase levels.

Sustained virological response to peginterferon plus ribavirin in chronic hepatitis C genotype 1 patients is associated with a persistent Th1 immune response

BACKGROUND

An impairment of cellular immune response may contribute to the persistency of hepatitis C virus infection.

AIM

To analyse the Th1/Th2 cytokine profile in peripheral blood CD4(+) and CD8(+) T cells from patients with chronic hepatitis C (CHC) during treatment with pegylated interferon-alpha2a plus ribavirin and to correlate the Th1/Th2 balance with virological response (SVR).

METHODS

Prospective longitudinal study: 44 naïve genotype 1 CHC patients received PEG-IFNalpha2a plus ribavirin for 48 weeks: 26 (59.1%) achieved a SVR, 13 relapsed (29.5%) and 5 (11.4%) were non-responders. Sixteen healthy controls were analysed. The production of IL-4, IFNgamma and TNFalpha by CD4(+) and CD8(+) T cells was measured using flow cytometry, both in resting and phorbol-ester-stimulated cells.

RESULTS

First three months of treatment: the synthesis of TNFalpha by phorbol-ester-stimulated-CD4(+) T cells was higher in patients with SVR (P < 0.01). At the end of treatment, SVR was associated with higher intracellular expression of IFNgamma by stimulated-CD4(+) and CD8(+) T cells (P < 0.05). At the end of follow-up, a higher intracellular expression of IFNgamma by CD4(+) T cells was associated with a SVR.

CONCLUSIONS

A Th1-type immune response was associated with achievement of a SVR, as indicated by the persistent elevation of intracellular IFNgamma and TNFalpha.

Resultados del tratamiento ortopédico del dedo en martillo por ruptura subcutánea del tendón extensor. Serie de 170 casos

Objetivo: El presente estudio tiene por objetivo demostrar que los pacientes con dedo en martillo por arrancamiento del tendón extensor o ruptura subcutánea, pueden beneficiarse del tratamiento ortopédico, reservando el tratamiento quirúrgico para casos con mala evolución.

Material y Método: Se realizó un estudio retrospectivo de un grupo 170 de pacientes que presentaban una deformación digital en martillo por ruptura subcutánea o arrancamiento del tendón extensor. Todos los casos fueron tratados ortopédicamente, ya sea en consulta precoz y hasta en casos con un retraso máximo de 8 semanas. El tratamiento utilizado fue una férula dorsal en forma de rejilla, moldeada a medida, inmovilizando sólo la articulación interfalángica distal en extensión por un período de tiempo medio de 54 días.

Resultados: Con un seguimiento medio de 5 meses, el déficit de extensión fue de 7° y la flexión alcanzó los 61°. Setenta y ocho pacientes de este grupo fueron evaluados después de un plazo medio de 5 años, obteniendo similares resultados, con un déficit de extensión medio de 5° y una movilidad en flexión media de 61°.

Conclusiones: La férula es pues el tratamiento de elección incluso en caso de consulta diferida; la cirugía sólo la utilizamos para casos de fracaso del tratamiento ortopédico y en pacientes exigentes ya sea por razones profesionales o de ocio.

Report of a National Conference on Donation after cardiac death

A national conference on organ donation after cardiac death (DCD) was convened to expand the practice of DCD in the continuum of quality end-of-life care. This national conference affirmed the ethical propriety of DCD as not violating the dead donor rule. Further, by new developments not previously reported, the conference resolved controversy regarding the period of circulatory cessation that determines death and allows administration of pre-recovery pharmacologic agents, it established conditions of DCD eligibility, it presented current data regarding the successful transplantation of organs from DCD, it proposed a new framework of data reporting regarding ischemic events, it made specific recommendations to agencies and organizations to remove barriers to DCD, it brought guidance regarding organ allocation and the process of informed consent and it set an action plan to address media issues. When a consensual decision is made to withdraw life support by the attending physician and patient or by the attending physician and a family member or surrogate (particularly in an intensive care unit), a routine opportunity for DCD should be available to honor the deceased donor's wishes in every donor service area (DSA) of the United States.

Epidemiological study of Rickettsia typhi infection in two provinces of the north of Spain: analysis of sera from the general population and sheep

Data relating to Rickettsia typhi infection in Spain are scarce. A serological survey of 383 serum samples (184 males, 199 females) from the general population and 120 sera from sheep were studied by immunofluorescence assay (IFA). The human serum samples were collected from the general population of Palencia and Burgos provinces, and sheep serum samples were collected from Palencia province. Of the 383 human serum samples studied, 29 were positive for antibodies against R. typhi (7.5%) No statistical differences were found according to age, sex, origin (rural vs. urban) or geographic distribution, but a significant difference was observed related to occupation. In addition, 69 serums were found positives for R. typhi in sheep samples (57.5%). Our results indicated the circulation of R. typhi infectious for humans and sheep in Palencia and Burgos provinces. This study indicates that sheep may be infected with R. typhi, and that animals can, therefore be used as indicators of the presence of this organism.

Contrast media: future aspects

In spite of the dramatic development in CT, there was no major breakthrough in the iodinated contrast media development. New agents based on hybrid between MRI and CT compounds may be a new innovative alternative. This new approach may also open new indications such as radiotherapy.

Continual supplementation with n-3 fatty acids does not modify plasma lipid profile in spinal cord injury patients

STUDY DESIGN

A prospective study during a diet modification.

OBJECTIVE

To observe the evolution of the plasma lipid profile in a group of spinal cord injury (SCI) patients given a supplement of a mixture of docosahexanoic acid (DHA) and eicosapentaenoic acid (EPA).

SETTING

Department of Physiological Sciences II, Medical School of the University of Barcelona and Guttmann Institut of Badalona, Barcelona, Spain.

METHODS

A total of 19 adult males with SCI, 17 with paraplegia and two with tetraplegia, were given a daily supplement of 1.5 g of DHA and 0.75 g of EPA for 6 months. Determination of plasma values of DHA, EPA, total cholesterol, HDL-c, LDL-c, VLDL-c, triglycerides, and glucose was performed before supplementation and at 3 and 6 months of supplementation.

RESULTS

A statistically significant increase in the plasma concentration of EPA (F=30.556, P<0.05) and DHA (F=106.6, P<0.05) was observed after 3 and 6 months of supplementation. However, there were no observable differences in the plasma concentration of total-cholesterol, HDL-c, LDL-c, VLDL-c, and triglycerides during the study.

CONCLUSION

DHA-EPA supplementation for 6 months does not modify the glycemic and lipid plasmatic levels in SCI patients. Despite its absence of effect on the serum lipid profile, n-3 fatty acids may induce beneficial cardiovascular effects in this population.

[Comparative study on the protective effect of two immunization schemes using a hepatitis B recombinant vaccine in vulnerable health science students]

OBJECTIVE

Demonstrate the protective effect of hepatitis B in vaccine vulnerable health sciences students, under 30 years with three schemes the vaccination, two of them are conventional three doses and another one with two doses.

HYPOTHESIS

Three schedules of vaccination dosage schemes hepatitis B produce antibody response over 10 IU/ml.

DESIGN

Analytical, experimental, longitudinal., prospective and concurrent cohort study.

MATERIALS AND METHOD

100 vulnerable female and male students of the Medical Technology Faculty of the UNMSM Medical School were enrolled at first. 89 students completed the final analysis due to the inclusion and exclusion criteria in accordance with the study purpose. A vaccine dosage of 20 ug of surface antigen in 1 mL through three dosage schemes was administered: month 0, 1, 6; month 0, 1, 2; and month 0, 1. Blood samples were taken before and 1, 2, 6, and 7 months after the first dosage administration to determine the anti-HBs level. Anti-HBs approximately 10 mIU/mL was defined as seroprotective value.

RESULTS

89 students under 30 years (average age: 23.5 years). 46 (51.7%) male individuals, and 43 (48.3%) female individuals.12.4% of students reached protection within 30 days from the first dosage; 98.8% reached protection within 30 days from the second dosage; and 100% reached protection 180 days later. After the second dosage, the three groups reached protection values, and at the end of the study, the average antibody levels were between 532.7 mIU/mL and 1237.2 mIU/mL.

CONCLUSIONS

This study showed an equivalent protective effect 7 months after the first dosage. An equivalent protective effect for hepatitis B was reached through three different vaccination schemes: conventional three dose scheme (month 0, 1, 6); two dose brief scheme (month 0, 1); and three dose brief scheme (month 0, 1, 2). A two dose scheme is suggested for individuals under 30 years, which would imply a higher compliance rate, lower cost, and a similar protection benefit.