Search

Vanadium is a strategic metal that has many important industrial applications and is generated by the use of burning fossil fuels, which inevitably leads to their release into the environment, mainly in the form of oxides. The wastes generated by their use represent a major health hazard. Furthermore, it has attracted attention because several genotoxicity studies have shown that some vanadium compounds can affect DNA; among the most studied compounds is vanadium pentoxide, but studies in vivo with oxidation states IV and III are scarce and controversial. In this study, the genotoxic and cytotoxic potential of vanadium oxides was investigated in mouse bone marrow cells using structural chromosomal aberration (SCA) and mitotic index (MI) test systems. Three groups were administered vanadium(IV) tetraoxide (V 2 O 4 ) intraperitoneally at 4.7, 9.4 or 18.8 mg/kg, and three groups were administered vanadium(III) trioxide (V 2 O 3 ) at 4.22, 8.46 or 16.93 mg/kg body weight. The control group was treated with sterile water, and the positive control group was treated with cadmium(II) chloride (CdCl 2 ). After 24 h, all doses of vanadium compounds increased the percentage of cells with SCA and decreased the MI. Our results demonstrated that under the present experimental conditions and doses, treatment with V 2 O 4 and V 2 O 3 induces chromosomal aberrations and alters cell division in the bone marrow of mice.

Background: Data on long-term neurodevelopmental outcomes of normocephalic children (born with normal head circumference) exposed to Zika virus in utero are scarce. We aimed to compare neurodevelopmental outcomes in normocephalic children up to age 48 months with and without Zika virus exposure in utero., Methods: In this prospective cohort study, we included infants from two cohorts of normocephalic children born in León and Managua, Nicaragua during the 2016 Zika epidemic. In León, all women pregnant during the two enrolment periods were eligible. In Managua, mother-child pairs were included from three districts in the municipality of Managua: all women who became pregnant before June 15, 2016, and had a due date of Sept 15, 2016 or later were eligible. Infants were serologically classified as Zika virus-exposed or Zika virus-unexposed in utero and were followed up prospectively until age 48 months. At 36 months and 48 months of age, the Mullen Scales of Early Learning (MSEL) assessment was administered. Primary outcomes were MSEL early learning composite (ELC) scores at 30-48 months in León and 36-48 months in Managua. We used an inverse probability weighting generalised estimating equations model to assess the effect of Zika virus exposure on individual MSEL cognitive domain scores and ELC scores, adjusted for maternal education and age, poverty status, and infant sex., Findings: The initial enrolment period for the León cohort was between Jan 31 and April 5, 2017 and the second was between Aug 30, 2017, and Feb 22, 2018. The enrolment period for the Managua cohort was between Oct 24, 2019, and May 5, 2020. 478 mothers (482 infants) from the León cohort and 615 mothers (609 infants) from the Managua cohort were enrolled, of whom 622 children (303 from the León cohort; 319 from the Managua cohort) were included in the final analysis; four children had microcephaly at birth and thus were excluded from analyses, two from each cohort. 33 (11%) of 303 children enrolled in León and 219 (69%) of 319 children enrolled in Managua were exposed to Zika virus in utero. In both cohorts, no significant differences were identified in adjusted mean ELC scores between Zika virus-exposed and unexposed infants at 36 months (between-group difference 1·2 points [95% CI -4·2 to 6·5] in the León cohort; 2·8 [-2·4 to 8·1] in the Managua cohort) or at 48 months (-0·9 [-10·8 to 8·8] in the León cohort; 0·1 [-5·1 to 5·2] in the Managua cohort). No differences in ELC scores between Zika virus-exposed and unexposed infants exceeded 6 points at any time between 30 months and 48 months in León or between 36 months and 48 months in Managua, which was considered clinically significant in other settings., Interpretation: We found no significant differences in neurodevelopmental scores between normocephalic children with in-utero Zika virus exposure and Zika virus-unexposed children at age 36 months or 48 months. These findings are promising, supporting typical neurodevelopment in Zika virus-exposed normocephalic children, although additional follow-up and research is warranted., Funding: National Institute of Child Health and Development, National Institute of Allergy and Infectious Diseases, and Fogarty International Center., Translation: For the Spanish translation of the abstract see Supplementary Materials section., Competing Interests: Declaration of interests EWG is supported by the National Eye Institute, the END Fund, and the Task Force for Global Health. All other authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Vanadium(V) and vanadium(IV) are the predominant redox forms present in the environment, and epidemiological studies have reported that prenatal vanadium exposure is associated with restricted fetal growth and adverse birth outcomes. However, data about the toxic effects of vanadium(IV) oxide (V 2 O 4 ) on the development of mammals are still limited. Therefore, in this work, 4.7, 9.4, or 18.7 mg/kg body weight/injection/day V 2 O 4 was administered through an intraperitoneal (ip) injection to pregnant mice from gestational days 6 to 16. The results showed that V 2 O 4 produced maternal and embryo-fetal toxicity and external abnormalities in the offspring, such as malrotated and malpositioned hind limbs, hematomas and head injuries. Moreover, the skeletons of the fetuses presented reduced ossification of the cranial bones, including the frontal and parietal bones, corresponding to head injuries observed in the external assessment of the fetuses. These results demonstrate that administration of V 2 O 4 to pregnant females in the organogenesis period adversely affects embryonic development., (© 2022 Wiley Periodicals LLC.)

The humeral head is considered the second most common site for osteonecrosis to occur after the femoral head. As seen in the femoral head, the circulatory implications characteristic of this condition are attributable to the interaction between a genetic predisposition and the exposure to certain risk factors. There is no consensus regarding the pathogenesis of osteonecrosis, yet the final common pathway results in disrupted blood supply, increased intraosseous pressure, and bone death. Disease staging using radiography and magnetic resonance imaging is predictive of disease progression and can help the orthopedic surgeon to guide treatment. Although there is a myriad of treatment modalities, there is a lack of high-quality evidence to conclude what is the most appropriate treatment option for each stage of humeral head osteonecrosis. Nonoperative treatment is the preferred option in early-stage disease, and it may prevent disease progression. Nonetheless, in some cases, disease progression occurs despite nonoperative measures, and surgical treatment is required. The purpose of this article is to provide an updated review of the available evidence on risk factors, diagnosis, and treatment of atraumatic humeral head osteonecrosis., (© 2022 The Authors.)

Temephos ( O , O , O ', O '-tetramethyl O , O '-thiodi- p -phenylene bis(phosphorothioate)) is a larvicide belonging to the family of organophosphate pesticides used for the control of different vectors of diseases, such as dengue, Zika, chikungunya, and dracunculiasis. The aim of this review was to discuss the available published information about temephos toxicokinetics and toxicity in mammals. Temephos is quickly absorbed in the gastrointestinal tract, distributed to all organs, and then it accumulates mainly in adipose tissue. It is metabolized by S -oxidation, oxidative desulfuration, and hydrolysis reactions, with the possible participation of cytochrome P450 (CYP). Temephos is mainly eliminated by feces, whereas some of its metabolites are eliminated by urine. The World Health Organization classifies it as class III: slightly dangerous with a NOAEL (no-observed adverse effect level) of 2.3 mg/kg/day for up to 90 days in rats, based on brain acetylcholinesterase (AChE) inhibition. A LOAEL (lowest observable adverse effect level) of 100 mg/kg/day for up to 44 days in rats was proposed based on cholinergic symptoms. However, some studies have shown that temephos causes toxic effects in mammals. The inhibition of the enzyme acetylcholinesterase (AChE) is one of its main demonstrated effects; however, this larvicide has also shown genotoxic effects and some adverse effects on male reproduction and fertility, as well as liver damage, even at low doses. We performed an extensive review through several databases of the literature about temephos toxicokinetics, and we recommend to revisit current assessment of temephos with the new available data.

In vitro assays have demonstrated that vanadium compounds interact with biological molecules similar to protein kinases and phosphatases and have also shown that vanadium oxides decrease the proliferation of cells, including human lymphocytes; however, the mechanism, the phase in which the cell cycle is delayed and the proteins involved in this process are unknown. Therefore, we evaluated the effects of vanadium oxides (V 2 O 3 , V 2 O 4 and V 2 O 5 ) in human lymphocyte cultures (concentrations of 2, 4, 8, or 16 μg/ml) on cellular proliferation and the levels of the p53, p21 and Cdc25C proteins. After 24 h of treatment with the different concentrations of vanadium oxides, the cell cycle phases were determined by evaluating the DNA content using flow cytometry, and the levels of the p21, p53 and Cdc25C proteins were assessed by Western blot analysis. The results revealed that the DNA content remained unchanged in every phase of the cell cycle; however, only at high concentrations did protein levels increase. Although, according to previous reports, vanadium oxides induce a delay in proliferation, DNA analysis did not show this occurring in a specific cell cycle phase. Nevertheless, the increases in p53 protein levels may cause this delay., (© 2021 Wiley Periodicals LLC.)

Thallium (Tl) is a heavy and toxic metal and a byproduct of several human activities, such as cement production, mining, and coal combustion. Thallium is found in fruits, vegetables, and animal fodder with high Tl contamination; therefore, it is an environmental pollution issue and a toxicological contamination problem for human beings and other organisms when exposed to it. The mutagenic potential of Tl and its compounds is controversial, and there are few in vivo studies on its effects. We conducted the animal bioassay Drosophila wing somatic mutation and recombination test (SMART) to test for genotoxicity and assessed the genotoxic effects of Tl acetate (TlCH 3 COO) and Tl sulfate (Tl 2 SO 4 ) on Drosophila melanogaster . Third instar larvae from the SMART standard cross (ST) were fed Tl acetate [0.2, 2, 20, 200, 600 and 1200 μM] and Tl sulfate [0.2, 2, 20, 200, and 600 μM]. Hexavalent chromium [CrO 3 , 500 μM] served as the positive control, and Milli-Q water served as the negative control. Only the high Tl 2 SO 4 [600 μM] concentration resulted in genotoxicity with 87.6% somatic recombination, and both salts disrupted cell division of wing imaginal disc cells, showing the expected cytotoxic effects. Genotoxic risks due to high metal levels by bioaccumulation of Tl +1 or its compounds require further evaluation with other in vivo and in vitro assays., Competing Interests: The authors declare no conflict of interest., (© 2021 The Authors.)

The recovery of injured nervous tissue, one of the main goals for regenerative therapeutic approaches, is often hindered by the limited axonal regeneration ability of the central nervous system (CNS). In this regard, the identification of scaffolds that support the reconstruction of functional neuronal tissues and guide the alignment of regenerating neurons is a major challenge in tissue engineering. Ideally, the usage of such scaffolds would promote and guide the axonal growth, a crucial phase for the restoration of neuronal connections and, consequently, the nerve function. Among the materials proposed as scaffolds for CNS regeneration, silk has been used to exploit its outstanding features as a biomaterial to promote axonal regeneration. In this study, we explore, for the first time, the possibility of using high-performance regenerated silk fibers obtained by straining flow spinning (SFS) to serve as scaffolds for inducing and guiding the axonal growth. It is shown that SFS fibers promote the spontaneous organization of dissociated cortical primary cells into highly interconnected cellular spheroid-like tissue formations. Neuronal projections (i.e., axons) from these cellular spheroids span hundreds of microns along the SFS fibers that act as guides and allow the connection of distant spheroids. In addition, it is also shown that SFS fibers serve as scaffolds for neuronal migration covering short and long distances. As a consequence, the usage of high-performance SFS fibers appears as a promising basis for the development of novel therapies, leading to directed axonal regeneration.

Thallium (Tl) is a highly toxic metal for human beings; higher amounts found in diverse fluids of pregnant women are associated with low birth weight and preterm birth. However, experimental data concerning their effects on the embryonic development of mammalian organisms are limited. Hence, in the present work, TI(I) acetate of 0, 4.6, 9.2, or 18.5 mg/kg body weight were administered by intraperitoneal injection to groups of 10 pregnant CD-1 mice on the 7th gestational day, and animals were sacrificed on day 18 of gestation. The fetuses obtained showed some variations, such as trunk bent over (18.5 mg/kg), tail variations (all doses), forelimbs malrotation and hind limbs (all doses). Skeletal examination of the fetuses showed a delay in the ossification of skull bones, ribs, and limbs (all doses). In conclusion, the Intraperitoneal injection of Tl(I) acetate to pregnant mice induced morphological variations and a delay of the fetus ossification., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: According to several studies in population of high-income countries (HIC), patients with Type 2 diabetes mellitus (DM) have a considerably higher risk of cardiovascular morbidity and mortality. However, it is not clear if the magnitude of this association can be widespread in other populations. The objective of this study was to determine the independent association between Type 2 DM and first cardiovascular event in Colombian Caribbean poor population with no records of previous cardiovascular events reported., Methods: We retrospectively reviewed the individual records from the hospitalizations database of 64,668 patients of cardiovascular risk management program from July 2014 to December 2015. We used a propensity score matching cohort analysis for this study. The Kaplan-Meier curves were constructed for the cardiovascular events related endpoints and matched Cox-regression analysis to estimate associations of a history of Type 2 DM with cardiovascular outcomes during 1.5 years of follow-up. A formal sensitivity analysis using The Breslow-Day and Tarone Homogeneity tests was conducted., Results: Out of 56,351 patients with no previous cardiovascular events records, 19,368 (34.4%) patients were found to suffer Type 2 DM. Using propensity scores for Type 2 DM, we gathered a cohort of 18,449 pairs of patients with and without Type 2 DM who were balanced on 22 baseline characteristics. A first cardiovascular event occurred in 650 (3.5%) and 403 (2.1%) matched patients with and without Type 2 DM, respectively, during 1.5 years of follow-up. Type 2 DM was associated with first cardiovascular event (HR 1.69; 95% CI 1.43-2.00; p = 0.000), AMI (HR 1.79; 95% CI 1.45-2.20; p = 0.000) and stroke (HR 1.54; 95% CI 1.18-2.02; p = 0.001). Hazard ratios (95% CIs) for the association of Type 2 DM with all-cause mortality, cardiovascular mortality and all-cause hospitalization were 1.36 (1.21-1.53; p < 0.001), 1.52 (1.12-2.08; p 0.004), and 1.20 (1.21-1.53; p < 0.001), respectively., Conclusion: Type 2 DM resulted to be a significant independent risk factor for first cardiovascular event in Colombian Caribbean poor population with no previous records of cardiovascular events.

Introduction: IDH1 mutation has been identified as an early genetic event driving low grade gliomas (LGGs) and it has been proven to exerts a powerful epigenetic effect. Cells containing IDH1 mutation are refractory to epigenetical reprogramming to iPSC induced by expression of Yamanaka transcription factors, a feature that we employed to study early genetic amplifications or deletions in gliomagenesis., Methods: We made iPSC clones from freshly surgically resected IDH1 mutant LGGs by forced expression of Yamanaka transcription factors. We sequenced the IDH locus and analyzed the genetic composition of multiple iPSC clones by array-based comparative genomic hybridization (aCGH)., Results: We hypothesize that the primary cell pool isolated from LGG tumor contains a heterogeneous population consisting tumor cells at various stages of tumor progression including cells with early genetic lesions if any prior to acquisition of IDH1 mutation. Because cells containing IDH1 mutation are refractory to reprogramming, we predict that iPSC clones should originate only from LGG cells without IDH1 mutation, i.e. cells prior to acquisition of IDH1 mutation. As expected, we found that none of the iPSC clones contains IDH1 mutation. Further analysis by aCGH of the iPSC clones reveals that they contain regional chromosomal amplifications which are also present in the primary LGG cells., Conclusions: These results indicate that there exists a subpopulation of cells harboring gene amplification but without IDH1 mutation in the LGG primary cell pool. Further analysis of TCGA LGG database demonstrates that these regional chromosomal amplifications are also present in some cases of low grade gliomas indicating they are reoccurring lesions in glioma albeit at a low frequency. Taken together, these data suggest that regional chromosomal alterations may exist prior to the acquisition of IDH mutations in at least some cases of LGGs.

Zika virus (ZIKV) is a mosquito-borne flavivirus that is responsible for recent explosive epidemics in the Americas. Notably, ZIKV infection during pregnancy has been found to cause congenital birth defects, including microcephaly, and ZIKV has been associated with Guillain-Barré syndrome in adults. Diagnosis and surveillance of Zika in the Americas have been challenging due to similar clinical manifestations and extensive antibody cross-reactivity with endemic flaviviral diseases, such as dengue. We evaluated four serological and two reverse transcription-PCR (RT-PCR) methods in acute-phase (mean day, 1.8), early-convalescent-phase (mean day, 16.7), and late-convalescent-phase (mean, ~7 months) samples from the same individuals in a long-term pediatric cohort study in Nicaragua. Well-characterized samples from 301 cases of Zika, dengue, or non-Zika, nondengue febrile illnesses were tested. Compared to a composite reference, an in-house IgM antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) and the NIAID-Biodefense and Emerging Infections (BEI) MAC-ELISA measuring IgM yielded sensitivities of 94.5% and 70.1% and specificities of 85.6% and 82.8%, respectively. The NS1 blockade-of-binding ELISA measuring anti-ZIKV NS1 antibody levels yielded sensitivities of 85.0% and 96.5% and specificities of 91.4% and 92.6% at early and late convalescence, respectively. An inhibition ELISA detecting total anti-ZIKV antibodies had sensitivity and specificity values of 68.3% and 58.3% for diagnosis and 94.0% and 98.6% for measuring annual infection incidence. Finally, the ZCD and Trioplex real-time RT-PCR assays detecting Zika, chikungunya, and dengue viruses both yielded a sensitivity of 96.1% and specificity of 100%. Together, these assays resolve the urgent need for diagnostic and surveillance tools for countries affected by Zika virus infections., (Copyright © 2018 American Society for Microbiology.)

The true incidence of light chain deposition disease (LCDD) restricted to the central nervous system (CNS) is unknown. To our knowledge only 7 cases of LCDD restricted to the brain have been previously reported. We herein describe an unusual example. A 44-year-old man presented with a history of ischemic retinopathy in 2004 and left lower extremity hypoesthesia in 2007 that progressed gradually to left-sided weakness and numbness in the 2 years prior to his hospitalization in 2015. A stereotactic brain biopsy was performed, displaying nonspecific hyaline deposits of amorphous "amyloid-like" material involving deep brain white matter and vessels. These were Congo red negative and were accompanied by a sparse lymphoplasmacytic infiltrate. Plasma cells demonstrated kappa light chain class restriction by chromogenic in situ hybridization (CISH). There was patchy reactivity with kappa immunohistochemistry in the amorphous deposits. A diagnosis of light chain deposition disease was made. Subsequent systemic myeloma and lymphoma workups were negative. Previously reported cases have included men and women, spanning the ages of 19 and 72 years, often presenting with hemiparesis, hypoesthesia, or seizures. Deposits have been reported in the cerebrum and cerebellum. T2/FLAIR (fluid attenuation inversion recovery) changes are usual, but lesions may or may not produce contrast enhancement. The light chain deposition may be of kappa or lambda class. Most lesions have been accompanied by local lymphoid and/or plasma cell infiltrates exhibiting light chain restriction of the same class as the deposits. In summary, LCDD limited to the CNS is a rare lesion consisting of deposition of amyloid-like, but Congo red-negative monotypic light chain usually produced by local lymphoplasmacytic infiltrates.

This study compares the lipid composition, including individual phospholipid molecular species of solubilized nAChR detergent complexes (nAChR-DCs) with those of the bulk lipids from their source, Torpedo californica (Tc) electric tissue. This lipidomic analysis revealed seventy-seven (77) phospholipid species in the Tc tissue. Analysis of affinity-purified nAChR-DCs prepared with C-12 to C-16 phospholipid analog detergents alkylphosphocholine (FC) and lysofoscholine (LFC) demonstrated that nAChR-DCs prepared with FC12, LFC14, and LFC16 contained >60 phospholipids/nAChR, which was more than twice of those prepared with FC14, FC16, and LFC12. Significantly, all the nAChR-DCs lacked ethanolamine and anionic phospholipids, contained only four cholesterol molecules, and a limited number of phospholipid molecular species per nAChR. Upon incorporation into oocytes, FC12 produce significant functionality, whereas LFC14 and LFC16 nAChR-DCs displayed an increased functionality as compared to the crude Tc membrane. All three nAChR-DCs displayed different degrees of alterations in macroscopic activation and desensitization kinetics.

Background: Non-melanoma skin cancer (NMSC) is the most common malignancy in transplant patients. The incidence of basal cell carcinoma (BCC) is 10 times greater than in the general population, while squamous cell carcinoma (SCC) is 100 times greater. The relationship between the BCC and SCC reverses and increases according to the degree of immunosuppression and sun exposure. One way to predict the risk of NMSC should be based on factors such as: total sun burden factor (TSB)., Objective: To determine the influence of various risk factors in the development of NMSC and its relation to the type and duration of immunosuppressive treatment, type of transplant, and TSB., Methods: We worked with a fledgling historical cohort in which patients with kidney or liver transplant were identified and recorded if they developed some form of skin cancer. To study the factors associated with NMSC, we resorted to the strategy of a case-control study. Dermatological examination was performed and a questionnaire of risk factors made in both groups., Results: Of the 140 patients enrolled, 51 were women and 89 men, 120 were renal transplant recipients and 20 liver transplants. Of patients who developed NMSC, 100% were renal transplant recipients. The median age was 48.5 years. Most cancer patients worked outdoors. A total of 78 lesions were found in 40 NMSC patients, 59 (76%) of them were SCC, and 19 (24%) BCC; 45% of all skin cancer patients had more than one injury. The worst affected areas were those photoexposed: 60% head and neck, trunk and upper extremities 18% 50%. In 30% of patients (12/40) 22 new tumors were identified (SCC 18 and BCC 4). No lesions were identified for melanoma. In multivariate logistic regression analysis, statistically significant features were: type-based immunosuppressive regimen of cyclosporine A, azathioprine and prednisone (OR: 59.7; 95% CI: 10.2-348), TSB > 10 (OR: 19; 95% CI: 3-120) and duration of use of immunosuppressive therapy (OR: 1.06; 95% CI: 0.9-1.1). The mean time from transplantation to first dermatological assessment was six years (+5.4). Of the patients, 93% had not regularly used sunscreen before and after transplantation., Conclusions: The dermatological assessment is convenient and easy to perform. Primary prevention, close monitoring, diagnosis, and treatment of skin lesions are essential components of a comprehensive program for the evaluation of transplant recipients, the purpose of which is to reduce the incidence and morbidity associated with cancer.

Tetanus is a potentially life-threatening infection characterized by muscle spasms. Cephalic tetanus is limited to muscles and nerves in the head and can occur after trauma to this area. Because of the rarity of cephalic tetanus clinicians may be unfamiliar with the clinical presentation unsuspecting of the diagnosis.

We report a case of penetrating eye globe injury due to a metallic nail. This is the first case evaluated by our service that presented with an intact 2.5-centimeter nail penetrating the right eye with a significant intraocular component that the patient did not remove. We describe the initial presentation and the multi-step surgery that this complicated injury required. The early postoperative visual acuity remained unchanged when compared to the presenting. In addition, the patient had no retinal pathology or optic nerve damage after the procedure.

Objective: Determine the susceptibility to five fluoroquinolones and cross-resistance of pneumococcusclinical isolates with different penicillin susceptibilities gathered in a community-based study., Design: Cross-sectional survey., Materials: Two hundred and thirty one (231) isolates were obtained from respiratory secretions or blood specimens from 231 patients with acquired acute respiratory infection or bacteremia., Outcome Measures: In vitro susceptibility to penicillin (PEN), ciprofloxacin (CIP), levofloxacin (LEV), gatifioxacin (GAT), moxifloxacin (MOX) and gemifioxacin (GEM) was determined with minimal inhibitory concentration (MIC) using the E test., Results: 42% of the isolates showed decreased susceptibility to PEN. The lowest antibiotic concentration that inhibited 90% of the isolates was 3 microg/ml (for CIP), 1 microg/ml (for LEV), 0.25 microg/ml (for GAT), 0.125 microg/ml (for MOX) and 0.032 microg/ml (for GEM). Median MIC for LEV, GAT, MOX and GEM increased with decreasing susceptibility to CIP. Susceptibility to CIP was similar between penicillin-susceptible and penicillin-resistant pneumococci., Conclusion: Third and fourth generation fluoroquinolones showed very high inhibitory activity, higher than that for CIP, for both penicillin-susceptible and penicillin-resistant pneumococci. We noted cross-resistance among fluoroquinolones.

Objectives: To determine the frequency and risk factors associated with peripheral neuropathy in a population of patients with hepatitis C virus infection., Methods: Cross-sectional study. Electrophysiological assessment included bilateral motor and sensory conduction studies of four limbs., Results: Thirty-one cases and 31 control subjects were studied. Eighteen patients (58%) from the group of patients infected with the hepatitis C virus had evidence of neuropathy. Only 3 (10%) persons from the control group exhibited neuropathy. Among the risk factors for neuropathy in the patients infected with hepatitis C virus, we found the following: positive rheumatoid factor, cryoglobulinemia, and cirrhosis or active hepatitis. Other risk factors were advanced age, prolonged time of evolution, high viral load of the hepatitis C virus, and low complement., Conclusions: The frequency of neuropathy encountered in our study was high (58%). In our study, a positive rheumatoid factor, cryoglobulins, and a high viral load were also associated with the presence of peripheral neuropathy. A high viral load could express possible direct viral damage.