Exploring novel electroanalytical approach using MWCNT nanostructures to quantify nimodipine

A new type of buckypaper of MWCNT with entrapped Nimodipine (NMD) drug was constructed. NMD features a nitroaromatic group that is electroreducible, and a dihydropyridine ring that can be electrooxidized. From the perspective of the nitroaromatic group's reductive capability, we have devised amperometric and voltammetric analytical strategies, including both differential pulse and linear voltammetric techniques. These methods are implemented using glassy carbon electrodes (GCE) modified with buckypaper (BP) disks composed of multiwalled carbon nanotubes (MWCNT), which are capable of adsorbing NMD. Furthermore, by capitalizing on the oxidative capacity of the dihydropyridine ring, we have designed strategies that involve amperometry using screen-printed electrodes (SPE) modified with BP-MWCNT mini discs within a Batch Injection Analysis Cell (BIAS) designed for SPE. The developed sensor was applied successfully to determine the drug in commercial tablets. The analytical parameters of this sensor were adequate, with a recovery value of 98.24 % and detection and quantification limits of 7.01 mgL-1 and 23.35 mgL-1, respectively using the DPV method.

A Novel Terrestrial Rabies Virus Lineage Occurring in South America: Origin, Diversification, and Evidence of Contact between Wild and Domestic Cycles

The rabies virus (RABV) is characterized by a history dominated by host shifts within and among bats and carnivores. One of the main outcomes of long-term RABV maintenance in dogs was the establishment of variants in a wide variety of mesocarnivores. In this study, we present the most comprehensive phylogenetic and phylogeographic analysis, contributing to a better understanding of the origins, diversification, and the role of different host species in the evolution and diffusion of a dog-related variant endemic of South America. A total of 237 complete Nucleoprotein gene sequences were studied, corresponding to wild and domestic species, performing selection analyses, ancestral states reconstructions, and recombination analyses. This variant originated in Brazil and disseminated through Argentina and Paraguay, where a previously unknown lineage was found. A single host shift was identified in the phylogeny, from dog to the crab-eating fox (Cerdocyon thous) in the Northeast of Brazil. Although this process occurred in a background of purifying selection, there is evidence of adaptive evolution -or selection of sub-consensus sequences- in internal branches after the host shift. The interaction of domestic and wild cycles persisted after host switching, as revealed by spillover and putative recombination events.

Evaluation of Two Real-Time, TaqMan Reverse Transcription-PCR Assays for Detection of Rabies Virus in Circulating Variants from Argentina: Influence of Sequence Variation

In rabies diagnosis, it is essential to count on a rapid test to give a quick response. The combined sensitivity and robustness of the TaqMan RT-PCR assays (qRT-PCR) have made these methods a valuable alternative for rabies virus (RABV) detection. We conducted a study to compare the applicability of two widely used qRT-PCR assays targeting the nucleoprotein gene (LysGT1 assay) and leader sequences (LN34 qRT-PCR assay) of RABV genomes, in all variants circulating in Argentina. A total of 44 samples obtained from bats, dogs, cattle, and horses, that were previously tested for rabies by FAT and conventional RT-PCR, were used in the study. All variants were successfully detected by the pan-lyssavirus LN34 qRT-PCR assay. The LysGT1 assay failed to detect three bat-related variants. We further sequenced the region targeted by LysGT1 and demonstrated that the presence of three or more mismatches with respect to the primers and probe sequences precludes viral detection. We conclude that the LysGT1 assay is prone to yield variant-dependent false-negative test results, and in consequence, the LN34 assay would ensure more effective detection of RABV in Argentina.

2326. Enterovirus-Associated Acute Flaccid Myelitis. Argentina′s Nationwide Surveillance of Acute Flaccid Paralysis 2016–2018

Background

Acute flaccid paralysis (AFP) surveillance is carried out in Argentina in the frame of the Polio Eradication Program. Acute flaccid myelitis (AFM) is a type of AFP and can be detected in the frame of AFP surveillance. Although many case series of AFM associated to enterovirus (EV) were released since 2014 in many countries, there were no notifications of this entity from Argentina until 2016.

Methods

Descriptive-observational study. AFP cases reported to the National Surveillance System (NSS) between 2016 and 2018 were included.

Results

From January 1, 2016 to December 31, 2018, 610 cases of AFP in children under 15 years old were registered (207 in 2016, 205 in 2017 and 198 in 2018). In 2016, from epidemiological weeks (EWs) 14 to 28, 23 cases of AFM were notified (median age 36 months; range: 3 months to 13 years). No special clustering was observed, and the number of AFM cases did not correlate with an increase in the annual rate of AFP notifications. Main prodromal were respiratory symptoms in 21 cases (91.3%) and fever in 18 (78.2%). One or two limbs were affected in 65%; in 35% mechanical ventilation was required. More than 90% had sequelae at discharge. Stool (ST), nasopharyngeal aspirate (NPA) and cerebrospinal fluid (CSF) samples were processed at the Regional Reference Laboratory facilities. RT nested PCR was employed. All detections are shown in Table 1. To note, In 12 cases (53%), EV D68 was detected (11, out of 16 NPA and 3, out of 11 ST samples). As for 2017, only one case of AFM was detected. Attempt of viral detection was unsuccessful. In 2018, 3 cases of AFM were detected, one EV C105, one Coxsackie B and one case without viral detection.

Conclusion

The occurrence of AFM cases in Argentina since 2016 is similar to the findings in other countries. An association with EV D68 is apparent, notwithstanding the finding of other EV, finding that further points to the causal association between EV D68 and AFM. As NPA is the sample of choice for AFM diagnosis, from 2019 the work-out of every case of AFP includes this sample as mandatory when AFM is suspected. Given the severity and the high rate of permanent sequelae, a high sensitivity of the health team must be sustained to keep with adequate surveillance, which allows prompt outbreak detection of other agents that can cause AFP in the last phase of polio eradication.

Disclosures

All authors: No reported disclosures.

Global phylodynamics of Echovirus 30 revealed differential behavior among viral lineages

Echovirus 30 (E30) is an important causative agent of aseptic meningitis worldwide. Despite this, the global and regional dispersion patterns, especially in South America, are still largely unknown. We performed an in-depth analysis of global E30 population dynamics, by using the VP1 sequences of 79 strains isolated in Argentina, between 1998 and 2012, and 856 sequences from GenBank. Furthermore, the 3D^pol regions of 329 sequences were analyzed to study potential recombination events. E30 evolution was characterized by co-circulation and continuous replacement of lineages over time, where four lineages appear to circulate at present and another four lineages appear to have stopped circulating. Five lineages showed a global distribution, whereas three other lineages had a more restricted circulation pattern. Strains isolated in South America belong to lineages E and F. Analysis of the 3D^pol region of Argentinean strains indicated that recombination events occurred in both lineages.

2497. Acute Flaccid Paralysis: 17-Year’s Active Epidemiological Surveillance in a Pediatric Hospital in Argentina

Background

Methods

Results

Conclusion

Disclosures

Unusual increase of cases of myelitis in a pediatric hospital in Argentina

INTRODUCTION

The association between enterovirus D68 and acute flaccid myelitis was first described in the United States in 2014. Since then, sporadic cases have been reported in Canada and Europe. This study describes a series of cases of acute flaccid myelitis at Hospital de Pediatría "Prof. Dr. Juan P. Garrahan," in Buenos Aires, Argentina, during 2016.

METHODS

Descriptive, retrospective study. All patients with acute flaccid myelitis and lesions in the spinal cord involving the gray matter, as observed in the magnetic resonance imaging (MRI) scan, hospitalized from 04/01/2016 to 07/01/2016, were included in the study. Samples of nasopharyngeal secretions, fecal swabs and cerebrospinal fluid were collected and processed to look for the causative agent.

RESULTS

Ten patients were included. The median age was 4 years old (range from 3 months to 5 years old). Eight patients had a self-limiting febrile condition before the onset of neurological symptoms. Neurological findings were flaccid weakness in, at least, one limb, cervical paralysis (n= 2) and facial paralysis (n= 2). All patients had longitudinal lesions in the spinal cord, with gray matter involvement, mainly in the anterior horn. In all cases, a lumbar puncture (spinal tap) was performed. Pleocytosis was observed in 7 patients. In four children, enterovirus D68 was identified in nasopharyngeal secretions, and in one, it was detected in the cerebrospinal fluid. Neurological deficit persisted in all patients at the time of discharge.

CONCLUSIONS

The first outbreak of acute flaccid myelitis associated to enterovirus D68 is reported in Argentina. Active epidemiological surveillance will help to determine the true incidence, epidemiology and etiology of this disease.

Phylodynamics of vampire bat-transmitted rabies in Argentina

Common vampire bat populations distributed from Mexico to Argentina are important rabies reservoir hosts in Latin America. The aim of this work was to analyse the population structure of the rabies virus (RABV) variants associated with vampire bats in the Americas and to study their phylodynamic pattern within Argentina. The phylogenetic analysis based on all available vampire bat-related N gene sequences showed both a geographical and a temporal structure. The two largest groups of RABV variants from Argentina were isolated from northwestern Argentina and from the central western zone of northeastern Argentina, corresponding to livestock areas with different climatic, topographic and biogeographical conditions, which determined their dissemination and evolutionary patterns. In addition, multiple introductions of the infection into Argentina, possibly from Brazil, were detected. The phylodynamic analysis suggests that RABV transmission dynamics is characterized by initial epizootic waves followed by local enzootic cycles with variable persistence. Anthropogenic interventions in the ecosystem should be assessed taking into account not only the environmental impact but also the potential risk of disease spreading through dissemination of current RABV lineages or the emergence of novel ones associated with vampire bats.

High-content imaging for automated determination of host-cell infection rate by the intracellular parasite Trypanosoma cruzi

Chagas disease affects 8-11 million people, mostly in Latin America. Sequelae include cardiac, peripheral nervous and/or gastrointestinal disorders, thus placing a large economic and social burden on endemic countries. The pathogenesis and the evolutive pattern of the disease are not fully clarified. Moreover, available drugs are partially effective and toxic, and there is no vaccine. Therefore, there is an urgent need to speed up basic and translational research in the field. Here, we applied automated high-content imaging to generate multiparametric data on a cell-by-cell basis to precisely and quickly determine several parameters associated with in vitro infection of host cell by Trypanosoma cruzi, the causative agent of Chagas disease. Automated and manual quantifications were used to determine the percentage of T. cruzi-infected cells in a 96-well microplate format and the data generated was statistically evaluated. Most importantly, this automated approach can be widely applied for discovery of potential drugs as well as molecular pathway elucidation not only in T. cruzi but also in other human intracellular pathogens.

[Epidemiology of enterovirus associated with neurologic diseases]

This report describes the results of human enterovirus (HEV) detection and characterization using cell culture, polymerase chain reaction and molecular typing in 2167 samples obtained from acute flaccid paralysis, aseptic meningitis and acute encephalitis patients, from 1991 to 1998 in Argentina. HEV were isolated in 130 out of 666 cases (19.5%) and 36 out of 666 (5.4%). HEV RNA was detected in 28.8% (231/801) and 3.0% (21/700) of the patients with meningitis and encephalitis, respectively. Children with ages ranging from 1 to 9 years accounted for 75.3% of the meningitis cases and from 1 to 4 years for 58% of acute flaccid paralysis patients. Echovirus 4 (E4), E9, E30 and E17 were identified from meningitis outbreaks. Coxsackievirus A2 (CAV2), CBV2, CBV5, E7, E11, E19, E24, E29 and enterovirus 71 were recovered only from sporadic cases. Three different serotypes were identified in encephalitis patients: E4, E7 and E24. A total of 28 different serotypes of non-polio enteroviruses were detected from acute flaccid paralysis cases. The information here presented contributes to improving our knowledge about enteroviruses epidemiology in Argentina and their relationship with different neurological diseases. This study provides valuable data that could be useful to further research.

Association between HLA-DQB1 and cervical dysplasia in Vietnamese women

Host genetic background seems to play a key role in cervical carcinogenesis as only a small subset of women infected with high-risk human papillomaviruses (HPVs) develop cervical cancer. The rate of cervical cancer in Vietnamese women is notably high. To explore the association of human leukocyte antigen (HLA)-DQB1 alleles, HPV infection, and cervical dysplasia in this population, cervical smears were obtained from 101 women attending the obstetrics and gynecology clinic of Da Nang General Hospital in Vietnam. Besides the Papanicolaou test, HPV and HLA-DQB1 genotyping were performed using cervical smear DNA. Additionally, a subset of 30 blood samples was used as the gold standard for HLA genotyping. HLA-DQB1 alleles showed no association with HPV infection status. However, a positive association with cervical dysplasia was found for HLA-DQB1*0302 (P= 0.0229, relative risk (RR) = 4.737) and HLA-DQB1*0601 (P= 0.0370, RR = 4.038), whereas HLA-DQB1*0301 (P= 0.0152, RR = 0.221) was found negatively associated. The low diversity of HLA-DQB1 alleles, wide spectrum of HPV genotypes, and high prevalence of HPV 16 and HPV 18 observed in the study population suggest a permissive/susceptible genetic background that deserves further research. Total concordance of HLA-DQB1 genotyping results between blood and cervical cells confirms the potential value of cervical smears as an effective tool for the development of cervical cancer biomarkers.

Association between HLA-DQB1 and cervical dysplasia in Vietnamese women

Host genetic background seems to play a key role in cervical carcinogenesis as only a small subset of women infected with high-risk human papillomaviruses (HPVs) develop cervical cancer. The rate of cervical cancer in Vietnamese women is notably high. To explore the association of human leukocyte antigen (HLA)-DQB1 alleles, HPV infection, and cervical dysplasia in this population, cervical smears were obtained from 101 women attending the obstetrics and gynecology clinic of Da Nang General Hospital in Vietnam. Besides the Papanicolaou test, HPV and HLA-DQB1 genotyping were performed using cervical smear DNA. Additionally, a subset of 30 blood samples was used as the gold standard for HLA genotyping. HLA-DQB1 alleles showed no association with HPV infection status. However, a positive association with cervical dysplasia was found for HLA-DQB1*0302 (P = 0.0229, relative risk (RR) = 4.737) and HLA-DQB1*0601 (P = 0.0370, RR = 4.038), whereas HLA-DQB1*0301 (P = 0.0152, RR = 0.221) was found negatively associated. The low diversity of HLA-DQB1 alleles, wide spectrum of HPV genotypes, and high prevalence of HPV 16 and HPV 18 observed in the study population suggest a permissive/susceptible genetic background that deserves further research. Total concordance of HLA-DQB1 genotyping results between blood and cervical cells confirms the potential value of cervical smears as an effective tool for the development of cervical cancer biomarkers.

[Inverted metamorphopsia: an alteration in the perception of a special situation of objects]

OBJECTIVES

This study describes the characteristics of six patients who consulted because of episodes of perceptive alteration of extrapersonal space consisting in an inversion of the situation of objects although without changes in shape or size (inverted metamorphopsia).

PATIENTS

Six patients (4 males and 2 females) who presented episodes of inverted metamorphopsia were studied: 4 referred right-left inversion (axial plane), 1 upwards-downwards (saggital plane) and 1 inclination of environment (clockwise movement). None had any alteration in the perception of their own bodies during the episodes which lasted from 3 minutes to 1 hour, reporting from 1 to 40 episodes. The most notable antecedents were: traumatism and forced cervical posture (2), arterial hypertension (3), migraine (2), hyperlipemia (2) and protuberantial ischemia (1).

RESULTS

Intercritical neurologic exploration was normal. MR study showed leukoaraiosis (4), protuberantial paramedian infarctions (1) and was normal in one case of basilar migraine. Study of vestibular function (performed in 4 cases) did not show alterations. Three patients received antiepileptic drugs (1 carbamazepine and 2 gabapentin) with favorable response.

CONCLUSIONS

Inverted metamorphopsia is a paroxistic phenomenon which transduces a dysfunction of the posterior parietal cortex or its afferences (propioceptive, vestibular, retinian). The causes may be multiple (traumatism, migraine, ischemia). Antiepileptic drugs may have a therapeutic role in the cases with multiple episodes.

[Malignant prolactinoma with intra- and extracranial metastasis: clinico-radiologic study]

Malignant prolactinomas are very rare pituitary neoplasms which can be identified not from the hystopathologic nor neuroimaging aspects but only retrospectively from the presence of distant metastases. A 32-year-old male patient was diagnosed of a pituitary prolactinoma because of bitemporal hemianopsia on the basis of cranial MRI aspect and raised blood prolactin level. Visual signs improved under bromocriptine treatment but after surgical and X-ray therapies patient developed paralysis of V and XII left cranial nerves and suffered from medulocerebelous angle, vertebrae, spinal epidural space, lung, liver, suprarenal and femoral metastases. Patient died 3 years after the diagnosis time. Prolactin levels raised 2000 ng/ml. This is the first case of malignant prolactinoma described in the spanish literature and the more large one in number of metastatic localizations between the malignant prolactinomas from the literature. These kind of neoplasms can be partially ameliorated under X-ray and bromocriptine treatment but there is not, by the moment, a curative chemotherapy.

Green tea polyphenols induce apoptosis in vitro in peripheral blood T lymphocytes of adult T-cell leukemia patients

Green tea polyphenols (TEA) are known to exhibit antioxidative activity as well as tumor-suppressing activity. In order to examine the tumor-suppressing activity of TEA against adult T-cell leukemia (ATL), we cultivated peripheral blood T lymphocytes of ATL patients (ATL PBLs), an HTLV-I-infected T-cell line (KODV) and healthy controls (normal PBLs) for 3 days in the presence of TEA and its main constituent, epigallocatechin-3-gallate (EGCg), to measure cell proliferation and apoptosis, and to quantitate mRNAs of HTLV-I pX and beta-actin genes of the cultured cells. Growth of ATL PBLs was significantly inhibited by 9-27 microg/ml of TEA and EGCg, in contrast to minimal growth inhibition of T cells of normal PBLs. Inhibition of KODV was intermediate between ATL PBLs and normal PBLs. The ATL PBLs and KODV treated with 27 microg/ml of either TEA or EGCg induced apoptotic DNA fragmentation, producing terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL)-positive cells, while the normal PBLs treated with the same concentration of TEA or EGCg produced a negligibly small number of TUNEL-positive cells, in which apoptotic DNA fragmentation was not detectable. Expression of HTLV-I pX mRNA was suppressed more than 90% in ATL PBLs by treatment with 3-27 microg/ml of either TEA or EGCg, while expression of beta-actin mRNA was much less suppressed by treatment with the same concentration of TEA or EGCg. These results indicate that TEA and EGCg inhibit growth of ATL PBLs, as well as HTLV-I-infected T-cells, by suppressing HTLV-I pX gene expression and inducing apoptotic cell death.

[Isolated hemi-ataxia as a sign of mesencephalic lacunar infarction]

INTRODUCTION

Lesions of the dento-rubro-thalamo-cortical pathway may cause homolateral or contralateral hemiataxia, depending on whether they are found above or below the decussation which occurs at the level of the inferior colliculus. Most mesencephalic infarctions causing hemiataxia also show oculomotor involvement with nuclear or fascicular lesions of the third cranial nerves. This was not seen in the case we report.

CLINICAL CASE

We describe the case of a diabetic patient with a permanent right appendicular hemiataxia, without oculomotor involvement, caused by a lacunar infarct shown on MR imaging which was situated in the antero-external part of the left superior mesencephalum.

CONCLUSIONS

This case helps to clarify the topography of the thalamic radiations of the mesencephalic calotte, including the decussated superior dento-rubro-thalamic pathway to the red nucleus. Involvement of this, situated in the mesencephalic lateral vascular territory causes contralateral hemiataxia.

[Coma associated with migraine]

INTRODUCTION

Basilar migraine is a particular form of migraine with an aura in which crises of headache are accompanied by symptoms of dysfunction in the vertebro-basilar territory, including alteration of consciousness in the form of stupor or coma.

CLINICAL CASES

We report four patients, three men of 14, 17 and 83 years of age and one woman of 21. All had previous histories of migraine and presented with transitory episodes of coma. During the coma, the woman woke up spontaneously with intense bulimia. In the three men, it was seen, on injecting flumazenil, that the state of consciousness and the EEG returned to normal transiently. Neuroimaging studies (CT and MR) were normal in all patients.

CONCLUSIONS

Migraine-coma is an exceptional, emergency condition in which structural, infectious, toxic and metabolic pathology of the Central Nervous System should be ruled out. As well as in patients with basilar migraine, the association of migraine and coma may also be seen in patients with familial hemiplegic migraine and CADASIL and MELAS syndromes. It may be that gabaergic mechanisms are involved in the theoretical dysfunction of the ascending reticular activating system causing alteration of consciousness, since in the three patients in whom flumazenil was injected, there was a response.

[From writer's cramp to butcher's spasms: a case of interprofessional dystonia]

INTRODUCTION

Occupational or professional dystonia is a focal motor dystonic disorder which affect motor programs necessaries for the exercise of the patient's profession. Clinical case. A patient with writer's cramp in the childhood presented at the age of 22 years a new dystonia, which we name 'butcher's spasm', giving rise to a laboral incapacity. Neurological exam was normal except for right arm distal (writer's cramp) and proximal dystonias (butcher's cramp), with intentional tremor in the upper extremities. We classified, after complementary exams, the disease as idiopathic.

CONCLUSIONS

Idiopathic focal dystonias can progress to segmentary or multifocal dystonias, and, in exceptional cases as ours, can interfere with two different professional activities.

[Long chronic course of hemiparkinson-plus with l-dopa maintained response]

OBJECTIVE AND CLINICAL CASE: We describe and present a video film of a patient with a hemiparkinsonian illness associated with hemidystonia and pyramidalism, which responded to continuous L-Dopa treatment for twenty years, with no fluctuation or deterioration at the end of the dose-effect. CT and MR studies were normal.

CONCLUSIONS

The characteristics of this case with probable static unilateral dysfunction, basically presynaptic, of the nigrostriate via, make it reasonable to include it in the hemiparkinson-hemiatrophy group.

[Autoscopy and multiple sclerosis]

A female patient with clinically defined multiple sclerosis presented episodes of audiovisual hallucinations in the form of projections of her own body image speaking to her. EEG and EEG-Holter studies were normal. MRI revealed multiple areas of hypersignals in white matter, particularly in both temporal lobes. The episodes remitted with carbamazepine therapy. We postulate that this phenomenon of autoscopy, which is unusual in multiple sclerosis, may be related to a mechanism of ephaptic transmission in the temporal lobe that is inhibited by carbamazepine, or it may be related to seizure.

[Pseudotumor cerebri secondary to cerebral venous defects not identified by magnetic resonance]

Pseudotumour cerebri is the name of a syndrome characterized by headache and papilloedema, with normal cerebral CT/MR studies and CSF with a high pressure and normal laboratory findings. We describe four patients who fulfilled the diagnostic criteria of this condition (including normal 0.5T MR studies). They all had cerebral angiograms showing minor abnormalities localized to the level of the superior longitudinal sinus. All improved on treatment with anticoagulants and steroids. In view of these findings we consider that in cases of pseudotumour cerebri without a clear aetiological factor, an angio MR study should be done, or if this technique is not available, a cerebral angiogram should be done, to exclude cerebral venous drainage defects.

[Hemiballismus heralding thrombosis of the basilar artery]

We present a patient with top-of-the-basilar syndrome that was preceded by hemiballismus and progressed to coma and tetraplegia. Magnetic resonance imaging showed extensive infarction in the basilar artery territory. Cerebral angiography confirmed basilar artery obstruction. The patient died in spite of anticoagulation therapy.