Minimal-access retroperitoneal pancreatic necrosectomy for infected necrotizing pancreatitis: a multicentre study of a step-up approach.

BACKGROUND: Various minimally invasive approaches have been described for infected necrotizing pancreatitis. This article describes a modified minimal-access retroperitoneal pancreatic necrosectomy (MARPN) procedure assisted by gas insufflation. METHODS: This retrospective, observational study documented patients who had undergone a step-up MARPN between 1 January 2010 and 31 December 2016. A minimum follow-up of 1 year was required for inclusion. The step-up approach involved percutaneous catheter drainage followed by the modified MARPN and necrosectomy. If more than one access site was needed it was categorized as complex MARPN. RESULTS: Of 212 patients with infected necrotizing pancreatitis, 164 (77·4 per cent) underwent a step-up approach. The median number of percutaneous catheter drains and MARPN procedures was 3 (range 1-7) and 1 (1-6) respectively. Ninety patients (54·9 per cent) underwent complex MARPN. For residual necrosis after MARPN, three patients (1·8 per cent) underwent sinus tract gastroscopy, and 11 (6·7 per cent) had sinography combined with a tube change. However, operations in 13 patients (7·9 per cent) required conversion to open surgery. Postoperative complications developed in 103 patients (62·8 per cent). The mortality rate was 6·1 per cent (10 deaths). CONCLUSION: A step-up approach using a modified MARPN for infected necrotizing pancreatitis is a reasonable option.

ANTECEDENTES: Los procedimientos mínimamente invasivos se han convertido en los más frecuentes para el tratamiento de necrosis pancreáticas infectadas. El objetivo de este estudio fue presentar un procedimiento de necrosectomía pancreática retroperitoneal de acceso mínimo (minimal-access retroperitoneal pancreatic necrosectomy, MARPN) modificado y asistido mediante insuflación de gases, así como evaluar su seguridad y eficacia. MÉTODOS: Se realizó un análisis retrospectivo y observacional de los datos de un hospital desde el 1 de enero de 2010 hasta el 31 de diciembre de 2016. Se incluyeron en el análisis todos los pacientes en los que realizó un abordaje por etapas, que consistía en el drenaje percutáneo mediante la colocación de un catéter seguido de un procedimiento MARPN modificado, en los que se dispusiese de un seguimiento postoperatorio mínimo de 1 año. El MARPN en el lado derecho y la necrosectomía realizada a través de más de un acceso se clasificaron como MARPN complejo. Se evaluaron los resultados radiológicos y quirúrgicos. RESULTADOS: De 212 pacientes con necrosis pancreática infectada, en 164 (77,4%) se realizó un abordaje por etapas. La mediana del número de drenajes percutáneos y procedimientos MARPN fue 3 (rango, 1-7) y 1 (rango, 1-6), respectivamente. En 90 pacientes (54,9%) se realizó un MARPN complejo. Para la exéresis de necrosis residual después de un MARPN, en 3 pacientes (1,8%) se realizó mediante gastroscopia y en 11 pacientes (6,7%) con un recambio de drenaje bajo control radiológico. En 13 pacientes (7,9%) fue necesaria la reconversión a cirugía abierta. Hubo complicaciones postoperatorias en 103 pacientes (62,8%). La tasa de mortalidad fue del 6,1% (n = 10). CONCLUSIÓN: El abordaje por etapas con un MARPN modificado es seguro y efectivo en el tratamiento de la necrosis pancreática infectada.

Protective effects of folic acid against central nervous system neurotoxicity induced by lead exposure in rat pups.

Recent studies found folic acid is associated with lower blood lead (Pb) levels, and folate deficient children are more susceptible to the negative cognitive effects of Pb. This study evaluated the protective effects of folate supplementation against Pb exposure in rat pups and the mechanisms of protection. A total of 72 rats were used. Thirty were administered Pb only; 30, Pb and folic acid at the same time; and 12, only physiological saline. Protective effects of folic acid were examined at 14, 21, and 28 days after treatment. Lower blood Pb levels were found in all of the samples collected from the rats treated with folic acid. Downregulation of Bc1-2 expression and upregulation of Bax expression were observed in the neurons of folic acid-treated rats. Significantly more hematoxylin and eosin stained neurons were found in the folic acid treatment group. Nuclear enrichment and neuron apoptosis were observed by electron microscopy in the Pb-treated group. In conclusion, this study demonstrated that folic acid supplementation might offer efficient protective effects against Pb poisoning in rat pups, which was associated with less neuron damage and lower blood levels of Pb.

Antibody study in canine distemper virus nucleocapsid protein gene-immunized mice.

The gene for the nucleocapsid (N) protein of canine distemper virus was cloned into the pMD-18T vector, and positive recombinant plasmids were obtained by enzyme digestion and sequencing. After digestion by both EcoRI and KpnI, the plasmid was directionally cloned into the eukaryotic expression vector pcDNA; the positive clone pcDNA-N was screened by electrophoresis and then transfected into COS-7 cells. Immunofluorescence analysis results showed that the canine distemper virus N protein was expressed in the cytoplasm of transfected COS-7 cells. After emulsification in Freund's adjuvant, the recombinant plasmid pcDNA-N was injected into the abdominal cavity of 8-week-old BABL/c mice, with the pcDNA original vector used as a negative control. Mice were immunized 3 times every 2 weeks. The blood of immunized mice was drawn 2 weeks after completing the immunizations to measure titer levels. The antibody titer in the pcDNA-N test was 10(1.62 ± 0.164), while in the control group this value was 10(0.52 ± 0.56), indicating that specific humoral immunity was induced in canine distemper virus nucleocapsid protein-immunized mice.

Selecting representative microsatellite loci for genetic monitoring and analyzing genetic structure of an outbred population of orange tabby cats in China.

We optimized a panel of microsatellite markers from cat and tiger genetic data for efficient genetic monitoring and used it to analyze the genetic structure of an outbred cat stock in China. We selected a set of rich polymorphic microsatellite loci from 131 cat microsatellite loci and 3 Sumatran tiger microsatellite loci using agarose gel electrophoresis. Next, the set of optimized genetic markers was used to analyze the genetic variation in an outbred population of orange tabby cats in China by simple-tandem repeat scanning. Thirty-one loci rich in polymorphisms were selected and the highest allele number in a single locus was 8. Analysis of the orange tabby cat population illustrated that the average observed number of alleles, mean effective allele number, mean Shannon's information index, mean expected heterozygosity, and observed heterozygosity were 3.8387, 2.4027, 0.9787, 0.5565, and 0.5528, respectively. The 31 microsatellite markers used were polymorphic and suitable for analyzing the genetic structure of cats. The population of orange tabby cats was confirmed to be a well-outbred stock.

Preparation of monoclonal antibody of anti-feline calicivirus and establishment of double-antibody sandwich enzyme-linked immunosorbent assay detecting method.

This study aimed to prepare monoclonal antibody of feline calicivirus (FCV) and identify its basic biological characteristics. Saturated ammonium sulfate precipitation, combined differential centrifugation, and cesium chloride density gradient centrifugation were used for the purification of FCV. The purified FCV was used as antigen to immunize BALB/c mice. The hybridoma lines of anti-FCV monoclonal antibodies were established using cell fusion and hybridoma screening techniques. The subtypes of the monoclonal antibody were identified. The results showed that 3 strains of hybridoma cell lines stably secreted anti-FCV monoclonal antibody; they were named as D8, E5, and H4. The D8 and E5 were IgM subtype antibodies, and H4 was IgG2b subtype antibody. The monoclonal antibody obtained shared no cross-reactivity with feline parvovirus, canine parvovirus, and canine distemper virus. According to the different recognition sites of 2 monoclonal antibodies E5 and H4 to the FCV, they were used to coat microtiter plates and prepare 2 enzyme-labeled secondary antibodies to establish double-antibody sandwich enzyme-linked immunosorbent assay detecting method.

The identification of NP25: a novel protein that is differentially expressed by neuronal subpopulations.

A novel gene encoding a 25-kDa neuronal-specific protein, here named 'NP25', has been isolated as a cDNA clone from rat brain. The sequence of the NP25 cDNA reveals a single open reading frame that encodes a primary translation product of 206 amino acids. A search of the protein sequence databank indicates that NP25 is significantly homologous with three recently discovered muscle proteins: SM22 alpha, mp20 and calponin. The gene is specifically and ubiquitously expressed in the rat brain and has conserved sequences among chicken, rat, mouse and human. Rat brain NP25 was identified by Western blot using an antiserum elicited against trpE-NP25 fusion protein. On pH gradient electrophoresis, NP25 was separated into at least two isoforms with similar molecular weights. Immunocytochemistry and in situ hybridization demonstrated that NP25 was differentially expressed by neuronal subpopulations of the rat central nervous system. The highest concentration of NP25 protein was localized in central amygdaloid nuclei and glomeruli in the granule layer of cerebellum. The wide and differential distribution of NP25 in the brain suggests that it may play a particular important role in the function of specific neuronal systems.