What matters after sleeve gastrectomy: patient characteristics or surgical technique?

Background

The impact of operative technique on outcomes in laparoscopic sleeve gastrectomy has been explored previously; however, the relative importance of patient characteristics remains unknown. Our aim was to characterize national variability in operative technique for laparoscopic sleeve gastrectomy and determine whether patient-specific factors are more critical to predicting outcomes.

Cyst location and presence of high grade dysplasia or invasive cancer in intraductal papillary mucinous neoplasms of the pancreas: a seven institution study from the central pancreas consortium

Background

Traditionally, intraductal papillary mucinous neoplasms (IPMNs) of the pancreas with “high risk stigmata” (HRS) or “worrisome features” (WF) are referred for resection. We aim to assess if IPMN location is predictive of harboring either high grade dysplasia (HGD) or invasive cancer (IC).

Sabin and wild type polioviruses from children who presented with acute flaccid paralysis in Nigeria

Background

Sensitive poliovirus surveillance to detect vaccine-derived-polioviruses will continue to increase in importance.

Objective

Isolating and identifying poliovirus strains from children of pediatrics age in Nigeria.

Methods

A total of 120 fecal samples were randomly collected from children under the age of five who presented with acute flaccid paralysis. Samples were tested by tissue culture technique and further characterized by intratypic differentiation testing using ELISA and PCR methods.

Results

The study confirmed the presence of 22(18.3%) enteroviral isolates comprising 19(86.4%) polioviruses and 3(13.6%) non-polio enteroviruses. These 19 polioviruses include: Sabin-type poliovirus-1 (15.8%), poliovirus-2 (10.5%), poliovirus-3 (10.5%) and wild-type poliovirus-1 (63.2%) isolates. It showed that poliovirus infection was higher in children ages 6–11 months (18.9%), females (18.4%), northern states (91.0%) with no vaccination record (75.0%). Wild-type poliovirus-1 was isolated from the stool samples of 12(54.6%) children from northern states and in all age groups except 18–23 months. No significant differences (P >0.05) between poliovirus infection and age (18.9% vs. 17.7%; 81.9% vs. 18.2%) and sex (18.3% vs. 18.4%). There was significant differences (P<0.05) between poliovirus infection and location (91.0% vs. 9.0%) and history of polio vaccination (75.0% vs. 0.0%). No wild-type poliovirus was found in those with complete vaccination.

Conclusion

This study further confirms the presence of Sabin and wild-type poliovirus among children in Nigeria. The isolation of Sabin strain of poliovirus is advantageous to the polio eradication program as it is capable of inducing natural immunity in susceptible hosts. Transmission of wild-type poliovirus among children with incomplete vaccination poses a serious threat to polio eradication program in Nigeria. Environmental and serological surveillance with larger sample size are important for monitoring poliovirus circulation in Nigeria.     

Characterization and standardization of Sabin based inactivated polio vaccine: proposal for a new antigen unit for inactivated polio vaccines

GMP-batches of Sabin-IPV were characterized for their antigenic and immunogenic properties. Antigenic fingerprints of Sabin-IPV reveal that the D-antigen unit is not a fixed amount of antigen but depends on antibody and assay type. Instead of the D-antigen unit we propose standardization of IPV based on a combination of protein amount for dose and D-antigenicity for quality of the vaccine. Although Sabin-IPV type 2 is less immunogenic than regular wild type IPV type 2, the immunogenicity (virus neutralizing titers) per microgram antigen for Sabin-IPV type 2 is in the same order as for wild type serotypes 1 and 3. The latter observations are in line with data from human trials. This suggests that a higher dose of Sabin-IPV type 2 to compensate for the lower rat immunogenicity may not be necessary.     

Antigen sparing with adjuvanted inactivated polio vaccine based on Sabin strains

Six different adjuvants, each in combination with inactivated polio vaccine (IPV) produced with attenuated Sabin strains (sIPV), were evaluated for their ability to enhance virus neutralizing antibody titres (VNTs) in the rat potency model. The increase of VNTs was on average 3-, 15-, 24-fold with adjuvants after one immunization (serotypes 1, 2, and 3, respectively). Also after a boost immunization the VNTs of adjuvanted sIPV were on average another 7–20–27 times higher than after two inoculations of sIPV without adjuvant. The results indicate that it is feasible to increase the potency of inactivated polio vaccines by using adjuvants.     

Isolation and characterisation of poliovirus mutants resistant to heating at 50 degrees Celsius for 30 min

Poliovirus is heat-labile; on heating at 50 degrees Celsius for 30 min its infectivity decreases drastically and its antigenicity reverts from N to H. However, mutants resistant to heating at 50 degrees Celsius for 30 min from the Sabin 1 and 2 viruses were isolated by repeating the process of incubation of the virus stock at 50 degrees Celsius for 30 min and multiplication of the remaining virus in a cell culture. The isolated mutants were stable genetically, and maintained the rct and d markers of the parent virus. On electron microscopical examination, the mutants were observed to retain the intact morphology after being heated at 50 degrees Celsius for 30 min, while the parent virus was converted to empty particles devoid of RNA under the same conditions. On determination of the nucleotide sequence of the P1 region, a single nucleotide sequence substitution was detected at nucleotide no. 2741, resulting in an amino acid change from valine to alanine at the 87th position of VP1. This amino acid might be associated with the heat-resistance of the mutants. Furthermore, it was found that the thermostable mutants obtained in this study, which are resistant to "high" temperature (50 degrees Celsius) for a short time (30 min), were not stable against heating at the ambient temperature (37 degrees Celsius) for a long time (5 or 7 days). This suggests that the inactivation at high temperature for a short time and that at ambient temperature for a long time involve different mechanisms.