Effect of Endoscopic Sphincterotomy on Gallbladder Motility

In experimental animals, sphincterotomyfacilitates passage of solids from the gallbladder andinhibits gallstone formation apparently by improvementin gallbladder emptying. In humans, however, gallbladder emptying has not been studied followingendoscopic sphincterotomy (ES) in patients withgallstones. We therefore prospectively studied restingand cerulinstimulated gallbladder volumes by real timeultrasonography in 15 patients of choledocholithiasis withgallbladder in situ (eight with and seven withoutgallbladder calculi) before and after (after bile ductclearance) ES. ES significantly lowered restinggallbladder volume (21.2 ± 10.6 vs 11.1 ±5.0; P < 0.0001) and cerulin-stimulated residualgallbladder volume (10.8 ± 5.6 vs 4.4 ±2.1; P < 0.0001). ES also significantly increased thegallbladder ejection fraction (47.3 ± 12.1% vs 58.8 ± 11.1%; P < 0.0001). Therate constant for gallbladder emptying after cerulininfusion also increased significantly after ES(–0.022/min vs –0.031/ min; P < 0.0001).Significant improvement in gallbladder motility was observed in both groups ofpatients with and without gallbladder calculi. ESsignificantly improves gallbladder motility inhumans.     

Airway obstruction after extubation following use of transesophageal echocardiography for posterior fossa surgery in the sitting position.

We report respiratory obstruction following surgery in the sitting position with tracheal intubation and placement of a transesophageal echocardiography probe. Obstruction was due to pharyngeal oedema, which resolved with 24 hours. The mechanisms of this complication are discussed.     

Organisation and molecular analysis of repeated DNA sequences in the rice blast fungus Magnaporthe grisea

The distribution of a previously described repeated DNA sequence present as a 1.3-kb PstI fragment in the genome of the rice blast fungus Magnaporthe grisea was analysed by carrying out DNA fingerprint analysis of 36 isolates including rice, non-rice and laboratory strains. The analysis of various higher-molecular-weight PstI fragments with homology to the 1.3-kb repeat revealed that these may arise predominantly from transposon insertions or point mutations. Analysis of a 5.1-kb derivative revealed both a point mutation at a PstI site and an insertion of a putative transposable element which caused an increase in molecular weight from 1.3 to 5.1 kb. Another repeat element of 1.4 kb was identified and found to exist in association with the 1.3-kb repeat. Both 1.3- and 1.4-kb elements were found to be parts of MGR583 (Hamer et al. 1989), a LINE-like element. These elements were present in a high copy number in all the rice and a majority of non-rice pathogens indicating that MGR583 is not a host-specific sequence as reported earlier. Our results suggest that repeated DNA elements in M. grisea have amplified independently of one another and further indicate that different isolates of M. grisea may have evolved from several distinct lines of origin. Received: 12 April / 12 November 1996     

Extinction of the human leukocyte antigen homozygosity effect after two doses of the measles-mumps-rubella vaccine

We have reported associations between human leukocyte antigen (HLA) homozygosity and low measles antibody levels after one dose of the measles, mumps, and rubella (MMR) vaccine. Here, we examined associations between HLA homozygosity and immune responses to MMR after two doses of vaccine. We examined associations between HLA homozygosity and measles antibody levels in a group of 178 children (cohort 1) as well as associations between homozygosity and antibody levels and lymphoproliferative responses to MMR in 346 children (cohort 2). In cohort 1, HLA homozygotes and heterozygotes had similar increases in measles antibody levels after a second dose of measles vaccine. In cohort 2, HLA homozygosity was not associated with measles immune measures after two doses of vaccine. Homozygosity at the DPB locus was associated with increased rubella antibody levels, and homozygosity at the class IA alleles was associated with lower mumps lymphoproliferative response. Homozygosity at increasing numbers of loci was also associated with lower mumps antibody levels and lymphoproliferative response. Therefore, two doses of the MMR vaccine appear to induce sufficient antibody levels and lymphoproliferative responses against measles and rubella, regardless of HLA homozygosity status. However, children who are HLA homozygous may be less protected against mumps compared with children who are heterozygous.     

Frequency of measles virus-specific CD4+ and CD8+ T cells in subjects seronegative or highly seropositive for measles vaccine

The protective effect of measles immunization is due to humoral and cell-mediated immune responses. Little is known about cell-mediated immunity (CMI) to measles vaccine virus, the relative contribution of CD4(+) and CD8(+) T cells to variability in such immune responses, and the immunologic longevity of the CMI after measles vaccination in humans. Our study characterizes cellular immune response in subjects seronegative or highly seropositive for measles vaccine immunoglobulin G-specific antibody, aged 15 to 25 years, previously immunized with two doses of measles-mumps-rubella II vaccine. We evaluated the ability of subjects to respond to measles vaccine virus by measuring measles virus-specific T-cell proliferation. We examined the frequencies of measles virus-specific memory Th1 and Th2 cells by an ELISPOT assay. Our results demonstrated that proliferation of T cells in seronegative subjects was significantly lower than that for highly seropositive subjects (P = 0.003). Gamma interferon (IFN-gamma) secretion predominated over interleukin 4 (IL-4) secretion in response to measles virus in both groups. The median frequency of measles virus-reactive CD8(+) T cells secreting IFN-gamma was 0.09% in seronegative subjects and 0.43% in highly seropositive subjects (P = 0.04). The median frequency of CD4(+) T cells secreting IL-4 in response to measles virus was 0.03% in seronegative subjects and 0.09% in highly seropositive subjects (P = 0.005). These data confirm the presence of measles virus-specific cellular immune responses post-measles vaccine immunization in humans. The detection of measles virus-induced IFN-gamma and IL-4 production by ELISPOT can be used to identify measles virus-specific low-frequency memory T cells in subjects immunized with measles vaccine. These differences agree in directionality with the observed antibody response phenotype.     

Investigating the Acoustic Response and Contrast Enhancement of Drug-Loadable PLGA Microparticles with Various Shapes and Morphologies

Polymer nanoparticles and microparticles have been used primarily for drug delivery. There is now growing interest in further developing polymer-based solid cavitation agents to also enhance ultrasound imaging. We previously reported on a facile method to produce hollow poly(lactic-co-glycolic acid) (PLGA) microparticles with different diameters and degrees of porosity. Here, we investigate the cavitation response from these PLGA microparticles with both therapeutic and diagnostic ultrasound transducers. Interestingly, all formulations exhibited stable cavitation; larger porous and multicavity particles also provided inertial cavitation at elevated acoustic pressure amplitudes. These larger particles also achieved contrast enhancement comparable to that of commercially available ultrasound contrast agents, with a maximum recorded contrast-to-tissue ratio of 28 dB. Therefore, we found that multicavity PLGA microparticles respond to both therapeutic and diagnostic ultrasound and may be applied as a theranostic agent.     

Household Air Quality Risk Factors Associated with Childhood Pneumonia in Urban Dhaka,Bangladesh

To inform interventions to reduce the high burden of pneumonia in urban settings such as Kamalapur, Bangladesh, we evaluated household air quality risk factors for radiographically confirmed pneumonia in children. In 2009–2010, we recruited children < 5 years of age with pneumonia and controls from a population-based surveillance for respiratory and febrile illnesses. Piped natural gas was used by 85% of 331 case and 91% of 663 control households. Crowding, a tin roof in the living space, low socioeconomic status, and male sex of the child were risk factors for pneumonia. The living space in case households was 28% less likely than in control households to be cross-ventilated. Particulate matter concentrations were not significantly associated with pneumonia. With increasing urbanization and supply of improved cooking fuels to urban areas, the high burden of respiratory illnesses in urban populations such as Kamalapur may be reduced by decreasing crowding and improving ventilation in living spaces.