Blockade of dengue virus transmission from viremic blood to Aedes aegypti mosquitoes using human monoclonal antibodies.

BACKGROUND: Dengue is the most prevalent arboviral disease of humans. Virus neutralizing antibodies are likely to be critical for clinical immunity after vaccination or natural infection. A number of human monoclonal antibodies (mAbs) have previously been characterized as able to neutralize the infectivity of dengue virus (DENV) for mammalian cells in cell-culture systems. METHODOLOGY/PRINCIPLE FINDINGS: We tested the capacity of 12 human mAbs, each of which had previously been shown to neutralize DENV in cell-culture systems, to abrogate the infectiousness of dengue patient viremic blood for mosquitoes. Seven of the twelve mAbs (1F4, 14c10, 2D22, 1L12, 5J7, 747(4)B7, 753(3)C10), almost all of which target quaternary epitopes, inhibited DENV infection of Ae. aegypti. The mAbs 14c10, 747(4)B7 and 753(3)C10 could all inhibit transmission of DENV in low microgram per mL concentrations. An Fc-disabled variant of 14c10 was as potent as its parent mAb. CONCLUSIONS/SIGNIFICANCE: The results demonstrate that mAbs can neutralize infectious DENV derived from infected human cells, in the matrix of human blood. Coupled with previous evidence of their ability to prevent DENV infection of mammalian cells, such mAbs could be considered attractive antibody classes to elicit with dengue vaccines, or alternatively, for consideration as therapeutic candidates.

Field- and clinically derived estimates of Wolbachia-mediated blocking of dengue virus transmission potential in Aedes aegypti mosquitoes.

The wMel strain of Wolbachia can reduce the permissiveness of Aedes aegypti mosquitoes to disseminated arboviral infections. Here, we report that wMel-infected Ae. aegypti (Ho Chi Minh City background), when directly blood-fed on 141 viremic dengue patients, have lower dengue virus (DENV) transmission potential and have a longer extrinsic incubation period than their wild-type counterparts. The wMel-infected mosquitoes that are field-reared have even greater relative resistance to DENV infection when fed on patient-derived viremic blood meals. This is explained by an increased susceptibility of field-reared wild-type mosquitoes to infection than laboratory-reared counterparts. Collectively, these field- and clinically relevant findings support the continued careful field-testing of wMel introgression for the biocontrol of Ae. aegypti-born arboviruses.

Obstrucción colónica por pólipo hamartomatoso en una paciente pediátrica con esclerosis tuberosa / Bowel obstruction by hamartomatous polyp in a pediatric patient with tuberous sclerosis

La esclerosis tuberosa es una enfermedad autosómica dominante con gran variabilidad de expresión clínica. Se caracteriza por la presencia de tumores benignos en distintos órganos debidos a un desorden en la proliferación y diferenciación celular. Afecta, especialmente, la piel, el sistema nervioso central, el corazón y el riñón. El compromiso intestinal es infrecuente; afecta a adultos y compromete el colon sigmoide y el recto. En niños, hay solo dos casos descritos en la literatura; nuestra paciente sería el tercero. Presentamos a una paciente con esclerosis tuberosa, que comenzó, desde el mes de vida, con cuadros reiterados de suboclusión intestinal. La videocolonoscopía mostró una formación mamelonada que protruía hacia la luz del colon ascendente. Se realizó una hemicolectomía derecha. El informe anatomopatológico correspondió a un pólipo hamartomatoso. La evolución clínica y nutricional en el posquirúrgico fue muy favorable. Aunque poco frecuente, el pólipo hamartomatoso debe considerarse en el diagnóstico diferencial de oclusión intestinal en pediatría.

Tuberous sclerosis is an autosomal dominant disorder with a wide clinical spectrum of disease. It is characterized by development of benign tumors in multiple organs due to a disturbance in cellular growth and differentiation. It usually affects skin, brain, heart and kidney. Gastrointestinal involvement is rare and mainly restricted to adults and sigmoid colon and rectum. In children there are only two cases; our patient would be the third. We present a patient with tuberous sclerosis who began at the first month of life with repeated intestinal subocclusion. The videocolonoscopy showed a mass protruding into the lumen of the ascending colon. Right hemicolectomy was performed. The anatomopathological report corresponded to a hamartomatous polyp. The clinical and nutritional evolution in the postoperative period was very favorable. Although uncommon, the hamartomatous polyp should be considered in the differential diagnosis of intestinal occlusion in pediatrics.

[Bowel obstruction by hamartomatous polyp in a pediatric patient with tuberous sclerosis]. / Obstrucción colónica por pólipo hamartomatoso en una paciente pediátrica con esclerosis tuberosa.

Tuberous sclerosis is an autosomal dominant disorder with a wide clinical spectrum of disease. It is characterized by development of benign tumors in multiple organs due to a disturbance in cellular growth and differentiation. It usually affects skin, brain, heart and kidney. Gastrointestinal involvement is rare and mainly restricted to adults and sigmoid colon and rectum. In children there are only two cases; our patient would be the third. We present a patient with tuberous sclerosis who began at the first month of life with repeated intestinal subocclusion. The videocolonoscopy showed a mass protruding into the lumen of the ascending colon. Right hemicolectomy was performed. The anatomopathological report corresponded to a hamartomatous polyp. The clinical and nutritional evolution in the postoperative period was very favorable. Although uncommon, the hamartomatous polyp should be considered in the differential diagnosis of intestinal occlusion in pediatrics.

La esclerosis tuberosa es una enfermedad autosómica dominante con gran variabilidad de expresión clínica. Se caracteriza por la presencia de tumores benignos en distintos órganos debidos a un desorden en la proliferación y diferenciación celular. Afecta, especialmente, la piel, el sistema nervioso central, el corazón y el riñón. El compromiso intestinal es infrecuente; afecta a adultos y compromete el colon sigmoide y el recto. En niños, hay solo dos casos descritos en la literatura; nuestra paciente sería el tercero. Presentamos a una paciente con esclerosis tuberosa, que comenzó, desde el mes de vida, con cuadros reiterados de suboclusión intestinal. La videocolonoscopía mostró una formación mamelonada que protruía hacia la luz del colon ascendente. Se realizó una hemicolectomía derecha. El informe anatomopatológico correspondió a un pólipo hamartomatoso. La evolución clínica y nutricional en el posquirúrgico fue muy favorable. Aunque poco frecuente, el pólipo hamartomatoso debe considerarse en el diagnóstico diferencial de oclusión intestinal en pediatría.

Histiocitosis de células de Langerhans con compromiso vertebral y de partes blandas: Caso clínico / Langerhans cell histiocytosis with vertebral involvement and soft tissue extension: Clinical case

La histiocitosis de células de Langerhans es una enfermedad heterogénea de etiología desconocida, que se caracteriza por la proliferación no controlada de histiocitos. Es poco frecuente y, si bien el compromiso óseo es común, la afectación vertebral es rara. Se presenta una niña de 4 años que consultó por dolor abdominal difuso de un mes de evolución, al que se agregó constipación y, posteriormente, debilidad en los miembros inferiores. El examen físico mostraba clonus e hiperreflexia en los miembros inferiores y la marcha era inestable. Se realizó una resonancia magnética, que mostró la vértebra dorsal 9 (D9) plana con tejido blando patológico en el espacio epidural y laterovertebral. Se realizó una cirugía descompresiva, artrodesis para fijar la columna y toma de biopsia, que confirmó el diagnóstico de histiocitosis de células de Langerhans. Recibió 6 meses de tratamiento con metilprednisona y vinblastina, de acuerdo con el protocolo LCH III, con excelente evolución y remisión completa. Conclusión. Frente a una imagen radiológica de vértebra plana o colapso vertebral, debe pensarse en histiocitosis de células de Langerhans como diagnóstico diferencial.

Langerhans cell histiocytosis is a heterogeneous disease of unknown etiology characterized by proliferation of Langerhans cells. It is a rare disease. Bone involvement is common but vertebral disease is rare. We present a 4 year old patient with abdominal pain and neurologic symptoms. Magnetic resonance showed vertebra plana in D9 with involvement of paravertebral soft tissues. The child underwent surgery for decompression and biopsy. Biopsy confirmed Langerhans cell histiocytosis. She was treated with vinblastine and prednisone during 6 months following LCH-III with complete recovery of neurologic symptoms. Conclusion. Langerhans cell histiocytosis is a differential diagnosis in a radiograph with vertebra plana or collapse of vertebral body.

[Langerhans cell histiocytosis with vertebral involvement and soft tissue extension: clinical case]. / Histiocitosis de células de Langerhans con compromiso vertebral y de partes blandas: caso clínico.

UNLABELLED: Langerhans cell histiocytosis is a heterogeneous disease of unknown etiology characterized by proliferation of Langerhans cells. It is a rare disease. Bone involvement is common but vertebral disease is rare. We present a 4 year old patient with abdominal pain and neurologic symptoms. Magnetic resonance showed vertebra plana in D9 with involvement of paravertebral soft tissues. The child underwent surgery for decompression and biopsy. Biopsy confirmed Langerhans cell histiocytosis. She was treated with vinblastine and prednisone during 6 months following LCH-III with complete recovery of neurologic symptoms. CONCLUSION: Langerhans cell histiocytosis is a differential diagnosis in a radiograph with vertebra plana or collapse of vertebral body.

La histiocitosis de células de Langerhans es una enfermedad heterogénea de etiología desconocida, que se caracteriza por la proliferación no controlada de histiocitos. Es poco frecuente y, si bien el compromiso óseo es común, la afectación vertebral es rara. Se presenta una niña de 4 años que consultó por dolor abdominal difuso de un mes de evolución, al que se agregó constipación y, posteriormente, debilidad en los miembros inferiores. El examen físico mostraba clonus e hiperreflexia en los miembros inferiores y la marcha era inestable. Se realizó una resonancia magnética, que mostró la vértebra dorsal 9 (D9) plana con tejido blando patológico en el espacio epidural y laterovertebral. Se realizó una cirugía descompresiva, artrodesis para fijar la columna y toma de biopsia, que confirmó el diagnóstico de histiocitosis de células de Langerhans. Recibió 6 meses de tratamiento con metilprednisona y vinblastina, de acuerdo con el protocolo LCH III, con excelente evolución y remisión completa. Conclusión: frente a una imagen radiológica de vértebra plana o colapso vertebral, debe pensarse en histiocitosis de células de Langerhans como diagnóstico diferencial.

Papilomatosis respiratoria recurrente. Caso dínico / Recurrent respiratory papillomatosis. Case report

La papilomatosis respiratoria recurrente es una enfermedad rara que se caracteriza por el desarrollo de papilomas en toda la vía aérea. Es causada por el virus del papiloma humano. Su incidencia es de 4 por 100 000 en niños. La forma de transmisión es vertical durante el embarazo o el parto. Hay 130 variedades de virus del papiloma humano, de los cuales los tipos 6 y 11 son los que producen papilomatosis respiratoria recurrente, y especialmente el tipo 11 es el que desarrolla enfermedad más agresiva con recurrencia y progresión en todo el tracto respiratorio y, con menos frecuencia, en la región nasofaríngea. Se presenta un paciente de 7 años de edad con diagnóstico de papilomatosis respiratoria recurrente basado en la radiología y la endoscopía respiratoria, que permitió aislar el virus del papiloma humano tipo 11 en papilomas en laringe y tráquea y en material de lavado broncoalveolar.

Recurrent respiratory papillomatosis (RRP) is a rare condition characterized by recurrent growth of papilloma in the respiratory tract. RRP is caused by human papilloma virus. Its incidence is 4 per 100 000 children. Vertical transmission of the virus during gestation or during delivery is the major route of contracting the disease in children. One hundred and thirty different human papilloma virus types have been identified. Types 6 and 11 are involved in RRP and type 11 develops more aggressive disease with recurrence and progression to the respiratory tract and also nasopharyngeal surface. We present a 7 year old boy with diagnosis of RRP based on radiology and endoscopy.

Papilomatosis respiratoria recurrente. Caso dínico / Recurrent respiratory papillomatosis. Case report

La papilomatosis respiratoria recurrente es una enfermedad rara que se caracteriza por el desarrollo de papilomas en toda la vía aérea. Es causada por el virus del papiloma humano. Su incidencia es de 4 por 100 000 en niños. La forma de transmisión es vertical durante el embarazo o el parto. Hay 130 variedades de virus del papiloma humano, de los cuales los tipos 6 y 11 son los que producen papilomatosis respiratoria recurrente, y especialmente el tipo 11 es el que desarrolla enfermedad más agresiva con recurrencia y progresión en todo el tracto respiratorio y, con menos frecuencia, en la región nasofaríngea. Se presenta un paciente de 7 años de edad con diagnóstico de papilomatosis respiratoria recurrente basado en la radiología y la endoscopía respiratoria, que permitió aislar el virus del papiloma humano tipo 11 en papilomas en laringe y tráquea y en material de lavado broncoalveolar.(AU)

Recurrent respiratory papillomatosis (RRP) is a rare condition characterized by recurrent growth of papilloma in the respiratory tract. RRP is caused by human papilloma virus. Its incidence is 4 per 100 000 children. Vertical transmission of the virus during gestation or during delivery is the major route of contracting the disease in children. One hundred and thirty different human papilloma virus types have been identified. Types 6 and 11 are involved in RRP and type 11 develops more aggressive disease with recurrence and progression to the respiratory tract and also nasopharyngeal surface. We present a 7 year old boy with diagnosis of RRP based on radiology and endoscopy.(AU)

[Recurrent respiratory papillomatosis. Case report]. / Papilomatosis respiratoria recurrente. Caso clinic.

Recurrent respiratory papillomatosis (RRP) is a rare condition characterized by recurrent growth of papilloma in the respiratory tract. RRP is caused by human papilloma virus. Its incidence is 4 per 100,000 children. Vertical transmission of the virus during gestation or during delivery is the major route of contracting the disease in children. One hundred and thirty different human papilloma virus types have been identified. Types 6 and 11 are involved in RRP and type 11 develops more aggressive disease with recurrence and progression to the respiratory tract and also nasopharyngeal surface. We present a 7 year old boy with diagnosis of RRP based on radiology and endoscopy.

Comparative Susceptibility of Aedes albopictus and Aedes aegypti to Dengue Virus Infection After Feeding on Blood of Viremic Humans: Implications for Public Health.

Aedes albopictus is secondary to Aedes aegypti as a vector of dengue viruses (DENVs) in settings of endemicity, but it plays an important role in areas of dengue emergence. This study compared the susceptibility of these 2 species to DENV infection by performing 232 direct blood-feeding experiments on 118 viremic patients with dengue in Vietnam. Field-derived A. albopictus acquired DENV infections as readily as A. aegypti after blood feeding. Once infected, A. albopictus permitted higher concentrations of DENV RNA to accumulate in abdominal tissues, compared with A. aegypti. However, the odds of A. albopictus having infectious saliva were lower than the odds observed for A. aegypti (odds ratio, 0.70; 95% confidence interval, .52-.93). These results quantitate the susceptibility of A. albopictus to DENV infection and will assist parameterization of models for predicting disease risk in settings where A. albopictus is present.

Host and viral features of human dengue cases shape the population of infected and infectious Aedes aegypti mosquitoes.

Dengue is the most prevalent arboviral disease of humans. The host and virus variables associated with dengue virus (DENV) transmission from symptomatic dengue cases (n = 208) to Aedes aegypti mosquitoes during 407 independent exposure events was defined. The 50% mosquito infectious dose for each of DENV-1-4 ranged from 6.29 to 7.52 log10 RNA copies/mL of plasma. Increasing day of illness, declining viremia, and rising antibody titers were independently associated with reduced risk of DENV transmission. High early DENV plasma viremia levels in patients were a marker of the duration of human infectiousness, and blood meals containing high concentrations of DENV were positively associated with the prevalence of infectious mosquitoes 14 d after blood feeding. Ambulatory dengue cases had lower viremia levels compared with hospitalized dengue cases but nonetheless at levels predicted to be infectious to mosquitoes. These data define serotype-specific viremia levels that vaccines or drugs must inhibit to prevent DENV transmission.

Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications.

Superparamagnetic iron oxide nanoparticles can provide multiple benefits for biomedical applications in aqueous environments such as magnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles' surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality water-dispersible nanoparticles around 10 nm in size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11051-012-1100-5) contains supplementary material, which is available to authorized users.

Trifluralin toxicity in a Chagas disease mouse model.

Even though trifluralin (alpha,alpha,alpha-2,6-dinitro-N-N-dipropyl-p-toluidine) is effective for the treatment of experimental Chagas disease, more preclinical toxicity studies need to be performed. Cell toxicity of trifluralin was studied in Hep-G2 and Vero C76 cells treated with 50 and 150 microM trifluralin. The results show that duplication time, amount of cellular protein and cell protein/DNA values were normal. Histological, haematological and chemical parameters were measured in CF1 mice after oral trifluralin administration. Acute toxic effects were assayed by administration of 50 or 200 mg/kg body weight daily for 30 days, and chronic effects by administration of 200 mg/kg body weight once a week for 90 days (n = 20). In the acute scheme treatment, hepatic (glutamic-pyruvic, glutamic-oxalacetic and alkaline phosphatase activities; proteins and albumin plasma concentrations) and pancreatic (amylase, glycaemia) functions were normal. Mean corpuscular volume, haemoglobin and haematocrit decreased. Creatine phosphokinase, lactate dehydrogenase and glutamic-oxalacetic activity increased, suggesting lesion in myocardial tissue. Histology was normal, excepting for the heart (mild myocarditis). Similar results were observed in acutely treated animals. There were no differences in body weight gain for treated mice compared to controls. In view of the published therapeutic effects of trifluralin on CF1 Chagas disease model and considering the present results, trifluralin seems to be a moderately toxic drug with a potential selective effect on the myocardium.

Treatment of experimental chronic chagas disease with trifluralin.

We tested trifluralin against Trypanosoma cruzi in a model of chronic Chagas disease in mice. CF1 mice (n=148) were intraperitoneally infected with 10(5) trypomastigotes of T. cruzi, H510C8C3 clone. One hundred mice were partially treated with benznidazole. Mortality was 100% at day 41 in the control group (n=48). At day 90 of the chronic disease (74% survival) mice were divided into three groups and treated orally with trifluralin (50 mg/kg/day, n=26), benznidazole (50 mg/kg/day, n=25) and vehicle (peanut oil; control group, n=23) for 60 days. Electrocardiography (under pentobarbital anaesthesia, 30 mg/kg/dose), serologic immunofluorescence and microstrout were performed at the beginning and at the end of the treatment. Mice were sacrificed at day 10 after treatment; cardiac tissue was studied histopathologically and polymerase chain reaction (PCR) was performed. Spontaneous mortality was 30.43%, 3.85% and 4% in the control, trifluralin and benznidazole groups, respectively (significant survival, P=0.03). Microstrouts were negative in all three groups. Negative immunofluorescence titers were 0%, 16% (P=0.05) and 29% (P<0.02) in the control, trifluralin and benznidazole groups, respectively. The prevailing electrocardiographic disorder was prolongation of the PR interval in the control group, which was not significantly altered in trifluralin- and benznidazole-treated mice, suggesting that trifluralin and benznidazole improve or even stop the damage caused by the disease on the conduction system. Trifluralin- and benznidazole-treated animals showed similar histologic patterns of myocarditis. PCR results were negative for benznidazole and trifluralin (100% and 70.8%, respectively). These results show the therapeutic potential of trifluralin in the treatment of chronic Chagas disease.