Endoluminal MR imaging of porcine gastric structure in vivo

Background and aims

Recently, several new endoscopic instruments have been developed. However, even with the full use of current modalities, the safety of endoscopic surgery is not guaranteed. Information regarding factors such as fibrosis and the blood vessels under the mucosa is very important for avoiding procedure-related complications. The aim of this study was to define the detailed anatomy of the gastric wall structure in vivo using original endoluminal radiofrequency coils for safer endoscopic therapy.

Methods

Swine were used as the subjects and controlled with general anesthesia. Anatomical images were obtained with T1-weighted fast spin echo (T1FSE) and T2-weighted fast spin echo (T2FSE). Dynamic magnetic resonance (MR) angiography was also obtained with three-dimensional T1-weighted fast spoiled gradient recalled acquisition in the steady state (3D-DMRA) following the injection of hyaluronic acid sodium into the submucosal layer.

Results

Porcine gastric wall structure was visualized, and four layers were discriminated in the T1FSE and T2FSE images. The vascular structure was clearly recognized in the submucosa on 3D-DMRA.

Conclusion

Endoluminal MR imaging was able to visualize the porcine stomach with similar quality to endoscopic ultrasonography imaging. Additionally, it was possible to visualize the vascular structures in the submucosal layer. This is the first report to show that blood vessels under the gastric mucosa can be depicted in vivo.     

Clinical and molecular epidemiology of erythromycin-resistant beta-hemolytic lancefield group G streptococci causing bacteremia

Among 100 patients with group G beta-hemolytic streptococcal bacteremia in a 6-year period (1997 to 2002), seven had bacteremia caused by erythromycin-resistant strains. Five of the seven patients had cellulitis and/or abscesses. The two isolates resistant to erythromycin and clindamycin possessed erm genes, one ermTR and the other ermB. The five isolates resistant to erythromycin but sensitive to clindamycin and one of those resistant to both erythromycin and clindamycin possessed mef genes.     

A novel genotype of beak and feather disease virus in budgerigars (<Emphasis Type="Italic">Melopsittacus undulatus</Emphasis>)

House sparrow (Passer domesticus) is one of the most widely distributed wild birds in China. Five Newcastle disease virus (NDV) strains were isolated from house sparrows living around the poultry farms in southern China. These isolates were characterized by pathogenic assays and phylogenetic analysis. The results showed that all NDV isolates except one were velogenic and virulent for chickens. These four virulent strains for chickens possess the amino acid sequence ¹¹²R/K-R-Q-K/R-R-F¹¹⁷ in the F₀ cleavage site which is typical of velogenic NDV. Phylogenetic analysis indicated that these isolates belong to genotype VII and were closely related to the strains which were isolated from NDV outbreaks in chickens since 2000. One isolate of NDV from house sparrow belong to genotype II and was proved to be vaccine strain (Chicken/U.S./LaSota/46). The result of this study proved that house sparrow can carry the virulent NDV strains and the same genotype of viruses that are circulating in poultry are existing in house sparrows living around poultry farm in southern China.     

In vitro hydrolysis of blends from enantiomeric poly(lactide)s. Part 4: well-homo-crystallized blend and nonblended films

Well-homocrystallized enantiomeric blend and nonblended films were prepared from poly(L-lactide), i.e., poly(L-lactic acid) (PLLA) and poly(D-lactide), i.e., poly(D-lactic acid) (PDLA) by crystallization from the melt. The effects of enantiomeric blending on the in vitro autocatalytic hydrolysis of the homo-crystallized polylactide, i.e., poly(lactic acid) (PLA) films were investigated in phosphate-buffered solution (pH 7.4) at 37 degrees C for up to 24 months. In the period of 0-12 months, the effects of enantiomeric polymer blending on the autocatalytic hydrolysis were very small. This finding reflects that in the PLLA/PDLA blend film separate homo-crystallization of PLLA and PDLA into the respective crystallites reduced the peculiar strong interaction between PLLA and PDLA chains in the amorphous region between the homo-crystalline regions. In the period of 12-24 months, enantiomeric polymer blending significantly retarded the autocatalytic hydrolysis of the PLLA/PDLA blend film compared with that of the nonblended PLLA and PDLA films. This is attributable to the increased chain mobility and the reduced entanglement effects due to the chain cleavage to a great extent, resulting in the enhanced interaction between PLLA and PDLA chains. It was also revealed that the hydrolyzabilities of the PLA films can be widely varied by enantiomeric polymer blending, crystalline species and their amounts, and molecular weight.     

Neonatal estrogen treatment with β-estradiol 17-cypionate induces in post-pubertal mice inflammation in the ductuli efferentes,epididymis, and vas deferens,but not in the testis,provoking obstructive azoospermia

Neonatal estrogen treatment (NET) induces morphological changes in male reproductive organs. NET with β-estradiol 17-cypionate is reported to induce inflammation with stromal-epithelial abnormalities in the prostate and seminal vesicles in post-pubertal mice. The aim of this study was to investigate the histopathology of the testis, ductuli efferentes, epididymis, and vas deferens in mice after NET with β-estradiol 17-cypionate. No morphological changes in these organs were observed until 4 weeks after NET. However, some inflammatory cells were found in epididymis and vas deferens 6 weeks after NET. Eight weeks after NET, inflammatory cells spread to the ductuli efferentes and inflammation was severe from 6 to 12 weeks after NET. Inflammatory cells were never seen in the whole testis, but cystic dilatation of the rete testes with spermatogenic disturbance was found around the mediastinum testis. Many inflammatory cells emigrated into the lumen of the epididymis, resulting in complete absence of spermatozoa in the vas deferens. Most of the inflammatory cells penetrating into the epithelial layers of epididymal ducts were neutrophils. These results indicate that in post-pubertal mice, NET with β-estradiol 17-cypionate induces inflammation in the ductuli efferentes, epididymis, and vas deferens, but not in the testis, provoking obstructive azoospermia.     

B7-H4, a molecule of the B7 family,negatively regulates T cell immunity

We identify a B7 family molecule, B7-H4, by protein sequence analysis and comparative molecular modeling. While B7-H4 mRNA is widely distributed in mouse and human peripheral tissues, cell surface expression of B7-H4 protein is limited and shows an inducible pattern on hematopoietic cells. Putative receptor of B7-H4 can be upregulated on activated T cells. By arresting cell cycle, B7-H4 ligation of T cells has a profound inhibitory effect on the growth, cytokine secretion, and development of cytotoxicity. Administration of B7-H4Ig into mice impairs antigen-specific T cell responses whereas blockade of endogenous B7-H4 by specific monoclonal antibody promotes T cell responses. B7-H4 thus may participate in negative regulation of cell-mediated immunity in peripheral tissues.     

Intrauterine therapy with cytomegalovirus hyperimmunoglobulin for a fetus congenitally infected with cytomegalovirus

Reported herein is a case of hydrops fetalis in which the cord blood expressed cytomegalovirus (CMV) antigen. Fetal ascites was removed from an infected fetus with hydrops in utero and 2.5 g CMV hyperimmunoglobulin was administered into the fetal abdominal cavity at 28 weeks gestation. After immunoglobulin administration, fetal ascites vanished, preload index of the inferior vena cava decreased and platelet count of the infant increased. However, despite intrauterine therapy and intensive neonatal care, the infant died soon after birth. The expression of CMV antigen in the nucleus of polymorphonuclear leukocytes in fetal cord blood indicated that the fetal hydrops was caused by CMV infection. When symptomatic CMV infection of a fetus is suspected from serological and ultrasound findings, further examinations should be performed for the diagnosis. Intrauterine immunoglobulin therapy could be one of the therapeutic options for the affected fetus.