Encefalopatía necrotizante aguda asociada a influenza A / Influenza A-associated acute necrotizing encephalopathy

INTRODUCCIÓN: La encefalopatía necrotizante aguda (ENA) es una patología rara, caracterizada por compromiso de conciencia y presencia de múltiples lesiones encefálicas simétricas localizadas principalmente en tá lamo. Se asocia a alta letalidad e importantes secuelas. OBJETIVO: Describir el caso de un paciente escolar con ENA asociada a influenza-A con evolución favorable. CASO CLÍNICO: Paciente de 6 años de edad, con historia de 3 días de evolución de síntomas respiratorios altos asociados a fiebre (39 °C). Veinticuatro horas previo a la consulta destacaba compromiso de conciencia cualicuantitativo. Se realizó punción lumbar con proteinorraquia leve. En resonancia magnética (RM) se identificó focos de restricción a la difusión bilaterales de distribución simétrica, talámicos, en cuerpos mamila res, periacueductales, de tegmento pontino, hipocampales y en ambas cápsulas externas, asociado a componente hemorrágico y edema vasogénico, sugerente de ENA. Recibió tratamiento empírico con metilprednisolona y oseltamivir. Posteriormente, se recibió resultado positivo para virus influenza- AH1. Dado diagnóstico, se decidió administrar inmunoglobulina, evolucionando lento pero favora blemente. Al alta levemente bradipsíquico, con disminución de agudeza visual, lenguaje espontáneo y marcha con apoyo. A los 6 meses de seguimiento presentaba lenguaje y marcha normales, persis tiendo alteración visual a derecha. CONCLUSIÓN: Nuestro paciente presentó una ENA cuyo diagnóstico y manejo oportunos se asociaron a una favorable evolución neurológica en el largo plazo. Si bien la ENA es una patología infrecuente, la morbimortalidad asociada es altísima, por lo que resulta de gran importancia tener un alto grado de sospecha, a fin de solicitar estudio imagenológico dirigido, buscar causas infecciosas relacionadas e iniciar un manejo oportuno.

INTRODUCTION: Acute necrotizing encephalopathy of childhood (ANEC) is a rare disease characterized by alteration of consciousness and multiple symmetric brain lesions mainly involving the thalamus. It presents a high mortality rate and severe sequelae. OBJECTIVE: To describe a school-age patient with influenza A-related ANEC with favorable evolution. CLINICAL CASE: Six-year-old boy with 3 days history of upper respiratory symptoms and fever (39 °C). One day previous to admission, he presented altered state of consciousness. A lumbar puncture was performed, showing a mild increase of protein level in CSF. MRI showed bilateral foci of symmetric restricted signal in the thalamus, mammillary bodies, periaqueductal gray, ventral tegmentum, hippocampus, and in both external capsules, which was compatible with ANEC. The patient received empirical treatment with methylprednisolone and oseltamivir. Subsequently, a positive result was received for influenza. Considering diagnosis and severity of illness, it was decided to administer immunoglobulin. The patient got better slowly but favorably. At discharge, he still was mildly bradypsychic with decreased visual acuity, spontaneous speech and walking with assistance. At 6 months of follow-up, the patient presented normal speech and gait, with persistent visual impairment in the right eye. CONCLUSIONS: Our patient presented ANEC, whose timely diagnosis and management were associated with a favorable neurological evolution in the long term. Although ANEC is an infrequent pathology, it has very high morbidity and mortality rates, so it is very important to have a high degree of suspicion in order to request a targeted imaging study, search for related infectious causes, and start proper treatment.

[Influenza A-associated acute necrotizing encephalopathy]. / Encefalopatía necrotizante aguda asociada a influenza A.

INTRODUCTION: Acute necrotizing encephalopathy of childhood (ANEC) is a rare disease characterized by alteration of consciousness and multiple symmetric brain lesions mainly involving the thalamus. It presents a high mortality rate and severe sequelae. OBJECTIVE: To describe a school-age patient with influenza A-related ANEC with favorable evolution. CLINICAL CASE: Six-year-old boy with 3 days history of upper respiratory symptoms and fever (39 °C). One day previous to admission, he presented altered state of consciousness. A lumbar puncture was performed, showing a mild increase of protein level in CSF. MRI showed bilateral foci of symmetric restricted signal in the thalamus, mammillary bodies, periaqueductal gray, ventral tegmentum, hippocampus, and in both external capsules, which was compatible with ANEC. The patient received empirical treatment with methylprednisolone and oseltamivir. Subsequently, a positive result was received for influenza. Considering diagnosis and severity of illness, it was decided to administer immunoglobulin. The patient got better slowly but favorably. At discharge, he still was mildly bradypsychic with decreased visual acuity, spontaneous speech and walking with assistance. At 6 months of follow-up, the patient presented normal speech and gait, with persistent visual impairment in the right eye. CONCLUSIONS: Our patient presented ANEC, whose timely diagnosis and management were associated with a favorable neurological evolution in the long term. Although ANEC is an infrequent pathology, it has very high morbidity and mortality rates, so it is very important to have a high degree of suspicion in order to request a targeted imaging study, search for related infectious causes, and start proper treatment.

Method Based on the ß-Lactamase PenPC Fluorescent Labeled for ß-Lactam Antibiotic Quantification in Human Plasma.

Recently, Wong et al. have successfully developed a fluorescent biosensor based on the PenPC ß-lactamase which changes its intrinsic fluorescence in presence of ß-lactam antibiotics (BLAs). Here, we studied systematically this correlation among the fluorescence change of the biosensor and the concentration of different BLAs aimed at developing a novel method for estimating the concentration of a wide range of BLAs. This method showed high precision and specificity and very low interference from clinically relevant samples. We were able to monitor the pharmacokinetics of meropenem in healthy volunteers as well as in an ill animal model too, indicating that the implemented method could be suitable for clinical practice.

The INNs and outs of antibody nonproprietary names.

An important step in drug development is the assignment of an International Nonproprietary Name (INN) by the World Health Organization (WHO) that provides healthcare professionals with a unique and universally available designated name to identify each pharmaceutical substance. Monoclonal antibody INNs comprise a -mab suffix preceded by a substem indicating the antibody type, e.g., chimeric (-xi-), humanized (-zu-), or human (-u-). The WHO publishes INN definitions that specify how new monoclonal antibody therapeutics are categorized and adapts the definitions to new technologies. However, rapid progress in antibody technologies has blurred the boundaries between existing antibody categories and created a burgeoning array of new antibody formats. Thus, revising the INN system for antibodies is akin to aiming for a rapidly moving target. The WHO recently revised INN definitions for antibodies now to be based on amino acid sequence identity. These new definitions, however, are critically flawed as they are ambiguous and go against decades of scientific literature. A key concern is the imposition of an arbitrary threshold for identity against human germline antibody variable region sequences. This leads to inconsistent classification of somatically mutated human antibodies, humanized antibodies as well as antibodies derived from semi-synthetic/synthetic libraries and transgenic animals. Such sequence-based classification implies clear functional distinction between categories (e.g., immunogenicity). However, there is no scientific evidence to support this. Dialog between the WHO INN Expert Group and key stakeholders is needed to develop a new INN system for antibodies and to avoid confusion and miscommunication between researchers and clinicians prescribing antibodies.

Outcome of a workshop on applications of protein models in biomedical research.

We describe the proceedings and conclusions from the "Workshop on Applications of Protein Models in Biomedical Research" (the Workshop) that was held at the University of California, San Francisco on 11 and 12 July, 2008. At the Workshop, international scientists involved with structure modeling explored (i) how models are currently used in biomedical research, (ii) the requirements and challenges for different applications, and (iii) how the interaction between the computational and experimental research communities could be strengthened to advance the field.

Engineered human IgG antibodies with longer serum half-lives in primates.

The neonatal Fc receptor (FcRn) plays an important role in regulating the serum half-lives of IgG antibodies. A correlation has been established between the pH-dependent binding affinity of IgG antibodies to FcRn and their serum half-lives in mice. In this study, molecular modeling was used to identify Fc positions near the FcRn binding site in a human IgG antibody that, when mutated, might alter the binding affinity of IgG to FcRn. Following mutagenesis, several IgG2 mutants with increased binding affinity to human FcRn at pH 6.0 were identified at Fc positions 250 and 428. These mutants do not bind to human FcRn at pH 7.5. A pharmacokinetics study of two mutant IgG2 antibodies with increased FcRn binding affinity indicated that they had serum half-lives in rhesus monkeys approximately 2-fold longer than the wild-type antibody.

Humanization of a chicken anti-IL-12 monoclonal antibody.

Chicken anti-IL-12 monoclonal antibodies were isolated by phage display using spleen cells from a chicken immunized with human and mouse IL-12 as a source for library construction. One of the chicken monoclonal antibodies, DD2, exhibited binding to both human and mouse IL-12 in the single-chain Fv form and also after conversion to chicken-human chimeric IgG1/lambda antibody. The chicken DD2 variable regions were humanized by transferring their CDRs and several framework amino acids onto human acceptor variable regions. In the Vlambda, six chicken framework amino acids were identified to be important for the conformation of the CDR structure by computer modeling and therefore were retained in the humanized form; likewise, five chicken amino acids in the VH framework regions were retained in the humanized VH. The affinities of humanized DD2 IgG1/lambda to human and mouse IL-12 measured by competitive binding were nearly identical to those of chicken-human chimeric DD2 IgG1/lambda. This work demonstrates that humanization of chicken monoclonal antibodies assisted by computer modeling is possible, leading to a new way to generate therapeutic humanized antibodies against antigens to which the rodent immune system may fail to efficiently raise high affinity antibodies.