Cement bond strengths of titanium plates

The success of the oral rehabilitation of implant patients depends not only on the osseointegration of implant fixtures but also on maintaining the integrity of the connection of prosthetic superstructures to these fixtures. It was an objective of the present study to evaluate and compare cement bond strengths among rolled (R), cast (C) and metal-injection-molded (M) commercially pure titanium plates which were bonded with Panavia 21 (Kuraray) and Imperva (Shofu) cements. Two plates (15x5x1 mm) of each R, C, and M were lap-jointed (lap length: 5 mm). The joints were stored in 37 degrees C distilled water for 24 h, followed by tensile tests with an INSTRON system under 1 mm/min crosshead speed. It was found that the bond strength of R with Panavia 21 (PAN) was 5.31 (SD:1.5) MPa and 2.30 (0.83) MPa with Imperva (IMP) cement. These were improved by applying an alloy primer to 7.08 (1.31) MPa and 6.72 (1.63) MPa, respectively. Using PAN with primer application, C and M samples showed bond strengths of 7.99 (1.31) and 7.20 (2.50) MPa, while they were 5.83 (2.15) and 6.79 (2.09) MPa using IMP with primer. There was a significant difference (p<0.01) between PAN and IMP cements for C samples. Additionally, samples were pre-oxidized at 100 degrees C in air for 10 min. Bond strengths of PAN with the primer were 5.69 (2.25), 9.14 (1.28), and 5.60 (3.13) MPa for R, C, and M sample groups. If the cement with the primer was applied immediately after the polishing (instead of pre-oxidized surfaces), bond strengths were improved to 9.14 (1.78) for R, 9.29 (1.85) for C, and 9.36 (1.81) MPa for M sample group. At p<0.05 level, there was a significant difference between surface pre-condition of R and M, but no significance with C.     

Senescence marker protein-30 knockout mouse liver is highly susceptible to tumor necrosis factor-alpha- and Fas-mediated apoptosis

Senescence marker protein-30 (SMP30) is a calcium-binding protein that decreases in an androgen-independent manner with aging. To elucidate the physiological role of this protein, we introduced a null mutation of the SMP30 gene into the germ line of mice. Despite the complete lack of SMP30 (SMP30-/-), these mutant mice were indistinguishable from their wild-type (SMP30+/+) littermates in terms of development and fertilization capability. We then investigated the tissue susceptibility for apoptosis induced by cytokine using primary cultured hepatocytes, because SMP30 could rescue cells from cell death caused by calcium influx, using a calcium ionophore as previously described. SMP30-/- hepatocytes were found to be more susceptible to apoptosis induced by tumor necrosis factor-alpha (TNF-alpha) plus actinomycin D (ActD) than SMP30+/+ hepatocytes. In addition, the TNF-alpha/ActD-induced caspase-8 activity in SMP30-/- hepatocytes was twofold greater than that in SMP30+/+ hepatocytes. In contrast, no significant difference was observed in the TNF-alpha/ActD-induced nuclear factor-kappa B activation of SMP30+/+ versus SMP30-/- hepatocytes, indicating that SMP30 is not related to TNF-alpha/ActD-induced nuclear factor-kappa B activation itself. Moreover, deletion of the SMP30 gene enhanced liver injury after treatment in vivo with anti-Fas antibody and the SMP30+/- mice showed intermediate susceptibility to Fas-induced apoptosis. Collectively, these results demonstrate that SMP30 acts to protect cells from apoptosis.     

Variations in the expression of platelet-derived endothelial cell growth factor in human colorectal polyps

Platelet-derived endothelial cell growth factor (PD-ECGF) has been identified to be an angiogenic factor, and a close relationship between the expression of PD-ECGF and tumor development has been postulated. This study was designed to assess both the role of PD-ECGF in human colorectal polyps as well as its relationship to the expression of other oncogenes during colorectal carcinogenesis. One hundred twenty patients with colon polyps who had undergone a polypectomy were studied. The polyps were classified based on the pathological findings as nonneoplastic or sporadic adenoma. The polyps were immunostained for PD-ECGF and vascular endothelial cell growth factor (VEGF), as well as for Ki-67 antigen and p53. The correlations between expression of PD-ECGF and clinicopathologic factors were examined. PD-ECGF was expressed at significant levels only in adenomas: in 4 of the 20 polyps with severe dysplasia (20%), and in 5 of the 20 cases of carcinoma in adenoma (25%). PD-ECGF was not detected in the nonneoplastic polyps and in adenomas with low-grade dysplasia. The intensity of immunostaining for PD-ECGF in adenomas correlated with the expression of Ki-67 antigen (P < 0.001) but not with that of p53. VEGF was not detected in any types of polyps. Angiogenic factors in colorectal adenomas might play an important role in carcinogenesis. The correlated expression of PD-ECGF and Ki-67 antigen suggests that PD-ECGF might not only act as an angiogenic factor, but also as a tumor growth factor. Received: October 6, 1999 / Accepted: March 24, 2000     

Efficacy and safety of standard of care with/without bevacizumab for platinum‐resistant ovarian/fallopian tube/peritoneal cancer previously treated with bevacizumab: The Japanese Gynecologic Oncology Group study JGOG3023

We investigated the efficacy and safety of further bevacizumab therapy in patients with platinum‐resistant ovarian cancer whose disease had progressed after bevacizumab plus chemotherapy. In this multicenter, open‐label, phase II trial (JGOG3023), patients were randomized 1:1 to a single‐agent chemotherapy alone (either pegylated liposomal doxorubicin [40 or 50 mg/m² administered intravenously], topotecan [1.25 mg/m² intravenously], paclitaxel [80 mg/m² intravenously], or gemcitabine [1000 mg/m² intravenously]) or single‐agent chemotherapy + bevacizumab (15 mg/m² intravenously). The primary endpoint was investigator‐assessed progression‐free survival (PFS) according to RECIST version 1.1. Secondary endpoints were overall survival (OS), objective response rate (ORR), and response rate according to Gynecological Cancer Intergroup cancer antigen 125 criteria. In total, 103 patients were allocated to chemotherapy (n = 51) or chemotherapy + bevacizumab (n = 52). Median investigator‐assessed PFS was 3.1 and 4.0 mo in each group, respectively (hazard ratio [HR] = 0.54, 95% confidence interval [CI]: 0.32‐0.90, P = .0082). Median OS was 11.3 and 15.3 mo in each group, respectively (HR = 0.67, 95% CI: 0.38‐1.17, P = .1556). Respective ORRs were 13.7% and 25.0% (P = .0599) and response rates were 16.7% and 21.4% (P = .8273). The incidence of grade ≥3 treatment‐related AEs was 42.0% in the chemotherapy group and 54.9% in the chemotherapy + bevacizumab group; AEs were well tolerated, with only 2 and 12 events leading to discontinuation of therapy, respectively. Bevacizumab was effective beyond progressive disease and AEs were manageable. The observed improvement in PFS requires further verification.     

Glycine improves survival after hemorrhagic shock in the rat.

This study investigated the effect of glycine on hemorrhagic shock in the rat. Rats were bled to maintain mean arterial pressure at 30-35 mm Hg for 1 h and subsequently resuscitated with 60% shed blood and lactated Ringer's solution. Only 20% of rats receiving saline just prior to resuscitation survived 72 h after shock. Survival was increased by glycine (11.2-90.0 mg/kg, i.v.) in a dose-dependent manner (half-maximal effect = 25 mg/kg) and reached maximal values of 78% at 45 mg/kg. Eighteen hours after resuscitation, creatinine phosphokinase increased 23-fold, transaminases increased 33-fold, and creatinine was elevated 2.4-fold, indicating injury to the heart, liver, and kidney, respectively. Pulmonary edema, leukocyte infiltration, and hemorrhage were also observed. In the kidney, proximal tubular necrosis, leukocyte infiltration, and severe hemorrhage in the outer medullary area occurred in rats receiving saline. Glycine reduced these pathological alterations significantly. It has been reported that oxidative stress and tumor necrosis factor(TNF)-alpha-production are involved in the pathophysiology of multiple-organ injury after shock. In this study, free radical production was increased 4-fold during shock, an effect blocked largely by glycine. Increases in intracellular calcium and production of TNF-alpha by isolated Kupffer cells stimulated by endotoxin were elevated significantly by hemorrhagic shock, alterations which were totally prevented by glycine. Taken together, it is concluded that glycine reduces organ injury and mortality caused by hemorrhagic shock by preventing free radical production and TNF-alpha formation.     

Scoring systems for differentiating gastrointestinal stromal tumors and schwannomas from leiomyomas in the stomach

There is no practical predictive model for the diagnosis of gastrointestinal stromal tumors (GISTs). To establish a practical predictive model for the diagnosis of subepithelial lesions in the stomach, we reviewed patients with GISTs (n = 89), schwannomas (n = 7), and leiomyomas (n = 28).The tumor was more frequently found along the gastric cardia in the leiomyoma group (57.1%) than in the GIST/schwannoma group (2.1%, P < .01). Contrast enhancement (57.3% vs 0%, P < .01) and intra-tumoral necrosis (34.4% vs 0.0%, P < .01) were more frequently observed in the GIST/schwannoma group than in the leiomyoma group. On endoscopic ultrasonography, 58.3% of GISTs/schwannomas showed uneven echogenicity, whereas the echogenicity was uneven in 21.4% of leiomyomas (P < .01). There were no differences between the tumor color and the presence or absence of ulcer formation, tumor bleeding, irregularity of the tumor margin, cystic spaces, and hyperechoic spots between the 2 groups. Based on these results, we developed a 2-step diagnostic algorithm for GISTs/schwannomas. The first step comprises 1 endoscopic feature: a cardiac or non-cardiac location. Tumors with a cardiac location were judged as leiomyomas and those with a non-cardiac location were judged as GISTs/schwannomas, with 96.9% sensitivity and 57.1% specificity for GIST/schwannoma diagnosis. The second step comprises a combination of endoscopic (non-cardiac location), radiologic (positive contrast enhancement and intra-tumoral necrosis), and endosonographic (uneven echogenicity) features for a total of 4 points. We assigned 1 point to each feature. Tumors with scores of 2 to 4 were judged as GISTs/schwannomas, with 81.3% sensitivity and 92.9% specificity for GIST/schwannoma diagnosis.Our predictive model will be a practical guide for the management of gastric subepithelial lesions.     

A congenital ciliated epithelial cyst on the stomach of a B6C3F1 mouse.

Congenital anomalies of the alimentary tract are rare lesions in laboratory animals. We describe a congenital cyst attached to the greater curvature of the forestomach in a B6C3F1 mouse. The inner surface of the cyst was mostly covered with cuboidal or pseudostratified ciliated epithelium and was focally covered with the flat cuboidal epithelium. The base of the cyst appeared to be inserted between the layers of the outer longitudinal muscle layer of the forestomach, although no smooth muscle layer was evident in the free surface of the cyst wall. The cyst resembled duplication of the alimentary tract, as it was lined with ciliated epithelium and had developed at the greater curvature of the forestomach. Since the smooth muscle layer did not completely cover the whole wall and the cyst did not communicate with the gastric lumen, the cyst was not thought to be a standard duplication but rather a simple congenital cyst.     

Dietary intake of yacon roots (Smallanthus sonchifolius) affects gut microbiota and fecal mucin and prevents intestinal inflammation in mice

Consumption of yacon (Smallanthus sonchifolius) is associated with beneficial effects such as prevention of metabolic diseases. Yacon root is known to contain various bioactive components including indigestible carbohydrates, but the alteration of intestinal environment after treatment with yacon has not been fully investigated. This study investigated yacon-containing diet effects on the intestinal environment in mice, including microbial composition, short-chain fatty acid levels, and mucus content. After mice were administered yacon-containing diet for 4 weeks, 16S rRNA gene sequencing analyses revealed their fecal microbiota profiles. Organic acid concentrations in cecal contents were measured using an HPLC system. Compared to the control group, yacon-containing diet-received mice had significantly higher the concentrations of succinic acid, lactic acid, acetic acid, and propionic acid. The fecal mucin content was also higher in yacon-containing diet-received mice. Results of 16S rRNA gene sequencing analyses showed that the relative abundances of 27 taxa differed significantly in yacon-containing diet-received mice. Furthermore, results show effects of yacon administration on intestinal inflammation using 2,4,6-trinitrobenzene sulfonic acid induced colitis model in mice. Increased colonic damage and myeloperoxidase activity after 2,4,6-trinitrobenzene sulfonic acid treatment were suppressed in yacon-containing diet-received mice. Results suggest that oral intake of yacon root modulates the intestinal environment, thereby inhibiting intestinal inflammation.