The influence of the transposed stomach through the posterior mediastinum on the respiratory forced expiratory volume and forced vital capacity in patients with resected esophageal cancer.

Although the use of the posterior mediastinum and the stomach as a reconstruction option after esophagectomy has large acceptance all over the world, there are concerns about the potential respiratory impairment it could cause. We prospectively studied 35 patients regarding the forced expiratory volume and vital capacity. The patients were studied preoperatively and between the 45th and 60th postoperative days. The value of both parameters decreased, although they were still within normal clinical ranges. We concluded that this type of reconstruction does not harm the patients regarding the respiratory flow rates.

Isolation of Laribacter hongkongensis, a novel bacterium associated with gastroenteritis, from drinking water reservoirs in Hong Kong.

AIMS: Freshwater fish has been found to be the reservoir of Laribacter hongkongensis, a recently discovered bacterium associated with community-acquired gastroenteritis. However, little is known about the ecology of this bacterium in the aquatic environment. We carried out a surveillance study to investigate the presence of L. hongkongensis in water and freshwater fish from 10 drinking water reservoirs in Hong Kong. METHODS AND RESULTS: Using membrane filtration, L. hongkongensis was isolated from the waters of six reservoirs, with numbers ranging from 1 to 12 CFU l(-1). Higher recovery rates were observed in summer and during days of higher water and ambient temperatures. Of 27 freshwater fish collected from the reservoirs, L. hongkongensis was recovered from the intestines of two fish, a Goldfish and a Nile tilapia. Overall, 35 different pulsed-field gel electrophoresis patterns are found among the 59 isolates recovered from water and the two isolates from freshwater fish. CONCLUSIONS: The present report represents the first to demonstrate the presence of L. hongkongensis in natural water environments. SIGNIFICANCE AND IMPACT OF THE STUDY: Although it is unlikely that treated, drinking water is an important source of L. hongkongensis-associated gastroenteritis, one should be aware of the possibility of other contaminated water as a source of human infection.

Purification and characterization of a major secretory cellobiase, Cba2, from Cellulomonas biazotea.

A novel cellobiase (Cba2) was purified from the culture supernatant of Cellulomonas biazotea and characterized. Cba2 appeared to be a major secretory cellobiase in C. biazotea as its enzymatic activity was estimated to represent over 40% of the total extracellular beta-glucosidase activity. The enzyme was purified over 260-fold subsequent to ammonium sulfate precipitation, gel-filtration chromatography, anion-exchange chromatography, and reversed-phase high-performance liquid chromatography. Cba2 was shown by SDS-PAGE to have a large molecular mass of 109 kDa, which makes it one of the largest secretory cellobiases characterized. Its homogeneity was confirmed by N-terminal amino acid sequencing. The K(m) and V(max) values were 0.025 mM and 0.0048 mM min(-1), respectively, for the Cba2 hydrolysis of p-nitrophenyl-beta-d-glucopyranoside, and 0.73 mM and 0.00033 mM min(-1), respectively, for the hydrolysis of cellobiose (at 37 degrees C and pH 7.0). The purified enzyme has a pH optimum of 4.8 and the optimum temperature for activity is 70 degrees C. In view of the secretory nature of Cba2 and the fact that it is a major component of secretory cellobiases of C. biazotea, it is potentially important in the enzymatic degradation of cellulose, and its availability as a recombinant protein may facilitate the studies of its biotechnological applications.

The influence of the transposed stomach through the posterior mediastinum on the respiratory forced expiratory volume and forced vital capacity in patients with resected esophageal cancer.

Although the use of the posterior mediastinum and the stomach as a reconstruction option after esophagectomy has large acceptance all over the world, there are concerns about the potential respiratory impairment it could cause. We prospectively studied 35 patients regarding the forced expiratory volume and vital capacity. The patients were studied preoperatively and between the 45th and 60th postoperative days. The value of both parameters decreased, although they were still within normal clinical ranges. We concluded that this type of reconstruction does not harm the patients regarding the respiratory flow rates.

Detection of estrogen receptor alpha, carbonic anhydrase II and tartrate-resistant acid phosphatase mRNAs in putative mononuclear osteoclast precursor cells of neonatal rats by fluorescence in situ hybridization.

Increasing evidence suggests that estrogen deficiency in women promotes the expansion of populations of bone marrow cells that differentiate into osteoclasts under the influence of osteotropic hormones and local factors. A progressive cytoplasmic accumulation of osteoclastic bone resorbing enzymes, such as tartrate-resistant acid phosphatase (TRACP) and carbonic anhydrase II (CA II), characterizes osteoclast differentiation. To evaluate the possibility that estrogen may have a direct effect on osteoclast precursor cells, we investigated the mRNA levels of estrogen receptor a (ERa), TRACP and CA II genes in neonatal rat bone imprints by fluorescence in situ hybridization and confocal microscopy. Morphological assessment of bone imprints has shown that the putative mononuclear osteoclast precursor cells (MOPC) display strongly basophilic cytoplasm and a low nuclear/cytoplasmic ratio, while some of these cells possess pale-staining ruffled border regions similar to those observed in osteoclasts. Both CA II and TRACP mRNAs were detected in putative MOPC as well as multinuclear osteoclasts. The gene transcripts were mainly located in the cytoplasm of these cells. To determine whether these putative MOPC possess ER mRNA, a 637 base pair antisense ER riboprobe was used. The results indicated that MOPC which show TRACP reactivity express high levels of ER gene transcripts in their cytoplasm. In contrast, only a few multinuclear osteoclasts in the bone imprints possessed ER gene transcripts. Interestingly, the levels of ER mRNA in these multinuclear osteoclasts were very low compared with those in the putative MOPC. Treatment with RNase prior to hybridization resulted in a significant loss of signal in these cells. The results of these studies suggest that estrogen may have a direct role in modulating the recruitment of osteoclast precursor cells during osteoclastogenesis.

Gene expression of transforming growth factor-beta 1 and its type II receptor in giant cell tumors of bone. Possible involvement in osteoclast-like cell migration.

Giant cell tumor of bone (GCT) is a relatively rare skeletal neoplasm characterized by multinuclear giant cells (osteoclast-like cells) scattered in a mass of mononuclear cells. The currently favored hypothesis for the origin of cells within GCT is that the multinuclear giant cells are reactive osteoclasts, whereas the truly neoplastic cells are the major component of the mononuclear population. However, the pathological significance and the precise relationship of tumor cells and osteoclast-like cells in GCT have not been fully established. In this study, we evaluated two GCTs for the presence of transforming growth factor-beta 1 (TGF-beta 1) and TGF-beta type II receptor gene transcripts and attempted to establish a possible role for TGF-beta 1 in the interaction between tumor cells and osteoclast-like cells. By using in situ hybridization and Northern blot analysis, we have demonstrated that TGF-beta 1 mRNA transcript is consistently detected in both tumor mononuclear cells and osteoclast-like cells, whereas TGF-beta type II receptor gene transcript is only present in osteoclast-like cells. Moreover, isolated rat osteoclasts were tested for their ability to migrate in response to GCT-conditioned medium (GCTCM) in an in vitro chemotactic assay. Our results showed that GCTCM stimulates the migration of osteoclasts in a dose-dependent manner. Interestingly, only osteoclasts containing less than three nuclei can migrate through 12-mu pore filters. Addition of monoclonal antibody against TGF-beta significantly reduced but did not abolish the chemotactic activity of GCTCM. Moreover, TGF-beta type II receptor mRNA has been demonstrated in the normal rat osteoclasts and may be involved in the chemotactic action of TGF-beta 1. We concluded that TGF-beta 1, possibly in concert with other cytokines, is involved in the recruitment of osteoclast-like cells in GCT by acting in an autocrine or paracrine fashion.

Effect of aspirin on ulcer site blood flow in cat stomachs.

Radioactive microspheres were used to measure blood flow in the cat stomach during exposure to saline, 0.075 M HCl, and then 15 and 30 min after exposure to 20 or 40 mM aspirin in HCl. At the end of the experiment, the stomach wall was divided into ulcerated regions and adjacent nonulcerated areas. When exposed to saline, both regions had similar blood flow: 27 +/- 5 and 25 +/- 5 ml.min-1.100 g-1 (means +/- SE). Addition of acid caused a significant increase in blood flow to 41 +/- 7 ml.min-1.100 g-1 only at those sites that eventually ulcerated in the presence of aspirin. In the adjacent nonulcerated regions, blood flow was 31 +/- 5 ml.min-1.100 g-1 and was not significantly greater than the flow recorded during saline exposure. Aspirin caused ulcer site blood flow to increase dramatically to 89 +/- 12 and 122 +/- 18 ml.min-1.100 g-1 after 15 and 30 min, whereas the adjacent nonulcerated tissue rose to 40 +/- 6 and 44 +/- 5 ml.min-1.100 g-1, respectively. The ulcer site hyperemia with acid alone suggests higher mucosal permeability in these regions allowing back-diffusion of acid and injurious agents. The present data obtained in the cat do not support the notion that ischemia plays a role in initiating nonsteroidal anti-inflammatory drug (NSAID)-induced ulcers, but rather that acute NSAID ulcers are associated initially with a hyperemia.