Liver tissue engineering at extrahepatic sites in mice as a potential new therapy for genetic liver diseases

Liver tissue engineering using hepatocyte transplantation has been proposed as an alternative to whole-organ transplantation or liver-directed gene therapy to correct various types of hepatic insufficiency. Hepatocytes are not sustained when transplanted under the kidney capsule of syngeneic mice. However, when we transplanted hepatocytes with the extracellular matrix components extracted from Engelbreth-Holm-Swarm cells, hepatocytes survived for at least 140 days and formed small liver tissues. Liver engineering in hemophilia A mice reconstituted 5% to 10% of normal clotting activity, enough to reduce the bleeding time and have a therapeutic benefit. Conversely, the subcutaneous space did not support the persistent survival of hepatocytes with Engelbreth-Holm-Swarm gel matrix. We hypothesized that establishing a local vascular network at the transplantation site would reduce graft loss. To test this idea, we provided a potent angiogenic agent before hepatocyte transplantation into the subcutaneous space. With this procedure, persistent survival was achieved for the length of the experiment (120 days). To establish that these engineered liver tissues also retained their native regeneration potential in vivo, we induced two different modes of proliferative stimulus to the naive liver and confirmed that hepatocytes within the extrahepatic tissues regenerated with activity similar to that of naive liver. In conclusion, our studies indicate that liver tissues can be engineered and maintained at extrahepatic sites, retain their capacity for regeneration in vivo, and used to successfully treat genetic disorders.     

Laparoscopy-assisted and open distal gastrectomies for early gastric cancer at a general hospital in Japan

BACKGROUND/AIMS: At general hospitals in Japan, laparoscopic surgery for early gastric cancer is not yet popular. The benefits and feasibility of this procedure remain to be established. The aim of this study was to evaluate the surgical outcome of laparoscopy-assisted distal gastrectomy (LADG) in comparison with open distal gastrectomy (ODG) in a general hospital. METHODOLOGY: We performed LADG in 20 patients with early gastric cancer between 2000 and 2001. Clinicopathologic data, blood analyses, clinical course and financial cost of treating patients with LADG were compared with 22 patients treated with ODG between 1998 and 1999. RESULTS: All patients were treated successfully by LADG. Neither reduced operative curability nor increased complications were found with this procedure. Although LADG required a significantly longer operation time than ODG, blood loss was lower in LADG than in ODG. The leukocyte count on day 1 and day 3, and serum C-reactive protein levels on day 1 were significantly lower after LADG than after ODG. There was no significant difference between LADG and ODG in the period and volume of analgesics required. High body temperature continued longer after ODG than after LADG. The first walking, passage of flatus and oral diet initiation were significantly earlier in patients with LADG than in those with ODG. LADG required a significantly shorter hospital stay and less total hospital charge than ODG. CONCLUSIONS: Laparoscopy-assisted distal gastrectomy offered faster recovery of gastrointestinal function, a shorter hospital stay, and consequently less financial cost when compared with open surgery. Therefore, LADG may be a safe and recommendable procedure for patients with early gastric cancer at general hospitals in Japan.     

Short‐ and long‐term effect of sitagliptin after near normalization of glycemic control with insulin in poorly controlled Japanese type 2 diabetic patients

Aims/Introduction

The aim of the present study was to examine the short‐ and long‐term effect of sitagliptin on glucose tolerance after near normalization of glycemic control with insulin in poorly controlled type 2 diabetic patients.

Materials and Methods

We consecutively enrolled a total of 30 type 2 diabetic patients whose glycated hemoglobin levels (National Glycohemoglobin Standardization Program) were ≥7.4%, stopped all oral antidiabetic drugs and started insulin therapy. When fasting plasma glucose levels became <140 mg/dL, we carried out the first oral glucose tolerance test (OGTT). After 1‐week sitagliptin treatment (50 mg/day), the second OGTT was carried out. Furthermore, we evaluated the long‐term efficacy of sitagliptin on glucose tolerance after near normalization of glycemic control with insulin.

Results

After 1‐week sitagliptin treatment, the area under the curve of insulin was markedly increased, and the area under the curve of glucagon and glucose was markedly decreased. Duration of diabetes and insulin secretory capacity were correlated with the effect of sitagliptin. Furthermore, interestingly, near normalization of glycemic control with insulin therapy for 1–2 weeks brought out the long‐term effectiveness of sitagliptin on glucose tolerance for 24 weeks, which was not observed with other antidiabetic drugs.

Conclusions

These findings suggest that near normalization of glycemic control with insulin improves the clinical response to sitagliptin in poorly controlled type 2 diabetic patients.     

Usefulness of two-dimensional echocardiographic parameters of the left side of the heart to predict right ventricular failure after left ventricular assist device implantation

Right ventricular failure (RVF) after left ventricular assist device (LVAD) placement is associated with increased morbidity and mortality. Echocardiography is a primary imaging method in the assessment of cardiac function; however, visualization of the right-sided heart is often technically difficult in patients with heart failure. We aimed to create a simple and generally applicable scoring system based on "left-sided echocardiographic parameters" to provide complementary information for predicting RVF after LVAD surgery. We reviewed 111 consecutive patients undergoing LVAD surgery from 2007 through 2010. Echocardiograms within 5 days before surgery were analyzed. RVF was defined as an unexpected RV assist devices requirement, nitric oxide inhalation >48 hours, and/or inotropic support >14 days. Thirty-five patients (32%) developed RVF. LV end-diastolic dimension (LVEDD) was smaller, LV ejection fraction was greater, and the left atrial diameter/LVEDD ratio was greater (p < 0.05 for all comparisons) in patients with RVF than in those without RVF. An RVF score (LV echocardiographic RVF score) was determined as a sum of points based on receiver operator characteristics analysis: LVEDD >78, 79 to 70, and <70 mm; LV ejection fraction ≤19%, 19% to 33%, and >33%; and left atrial diameter/LVEDD <0.63, 0.63 to 0.68, and >0.68; each variable was associated with 0 and 1 point and 2 points, respectively. LV echocardiographic RVF score ≥3 was associated with RVF with a sensitivity of 88.6% and score ≥5 with a specificity of 80.3%. In conclusion, patients with relatively small LV size, preserved LV contraction, and dilated left atrium were at higher risk for RVF after LVAD surgery. In conclusion, LV echocardiographic RVF score provides a novel tool to predict RVF after LVAD surgery, which does not involve invasive or technically complicated procedures.     

Potential high virulence for infective endocarditis in Streptococcus mutans strains with collagen-binding proteins but lacking PA expression

Objective

Streptococcus mutans, an aetiologic agent of dental caries, is a pathogen for infective endocarditis (IE). We investigated strains that express collagen-binding proteins (CBPs) with further classification based on expression of the 190-kDa protein antigen (PA).

Method

Zeta-potential values of strains TW871 (CBP+/PA+) and MT8148 (CBP−/PA+), and their respective PA-defective mutant strains TW871PD (CBP+/PA−) and MT8148PD (CBP−/PA−), were analysed, as were their adhesion to and invasion of human umbilical vein endothelial cells (HUVECs). The distribution of strains from the oral cavities of 200 healthy individuals was analysed for CBP and/or PA expression and the strains were characterised for their adhesion and invasion properties.

Results

TW871PD and MT8148PD showed significantly lower zeta-potential values than TW871 and MT8148, respectively. Collagen-binding rates were significantly higher for TW871PD than for TW871 but nearly negligible for MT8148 and MT8148PD. The adhesion and invasion rates of HUVECs were significantly higher for TW871PD than for TW871 and significantly higher for TW871 than for MT8148 and MT8148PD. The prevalence of CBP+ strains was ∼10% and ∼3% in the case of CBP+/PA− strains. Analyses of 200 clinical strains showed the CBP+/PA− group to have higher adhesion and invasion rates than other groups.

Conclusions

CBP+/PA− S. mutans strains, despite their low distribution frequency, may be highly virulent for infective endocarditis.     

Horizontal impaction of primary mandibular bilateral central incisors identified in 2-year-8-month-old girl

A girl aged 2 years and 8 months came to our clinic for consultation with regard to unerupted primary mandibular bilateral central incisors. An intraoral examination revealed that the teeth had not emerged into the oral cavity and showed a tooth crown morphology similar to that of the primary mandibular incisors, which appeared in the lingual submucosal area outside of the mandibular dental arch. Periapical radiographs demonstrated that the tooth crowns of both affected teeth were severely displaced to the lingual side. Computed tomography examinations were performed to clarify the three-dimensional positions of the affected teeth and their permanent successors, which revealed that the affected teeth were located in their estimated positions and had a standard root morphology. In addition, the permanent successors, which had not initiated root formation, were located close to the affected teeth. We decided to postpone extraction of the affected teeth and perform periodical examinations until the roots of the permanent successors are sufficiently formed. At the age of 2 years and 10 months, the edge of the tooth crown of the primary mandibular left central incisor was found emerged into the oral cavity. According to her parents, the patient did not complain of the emerging edge and no abnormal conditions were observed around the tooth.     

Rathke’s cleft cysts with significant squamous metaplasia—high risk of postoperative deterioration and close origins to craniopharyngioma

Background

Rathke’s cleft cyst (RCC) with significant squamous and/or stratified epithelium including smooth transition from single cuboidal to squamous epithelium (tRCC) is rare and possibly represents an intermediate form to craniopharyngioma.

Methods

Twelve patients with histologically confirmed tRCC were retrospectively investigated from a series of 167 cases of RCC and 96 cases of craniopharyngiomas. Clinical data were reviewed, and immunohistochemistry findings for cytokeratins and β-catenin were examined.

Results

All lesions were located in the sella turcica with marked extension to suprasellar cistern. Six of the 12 patients had suffered postoperative re-enlargement, and three of these six patients required more than two additional operations and irradiation. CAM5.2 was positive in the glandular epithelium in all tRCCs and focally positive in the squamous epithelium of all these tRCCs. 34βE12 was positive in the squamous epithelium in all tRCCs and focally positive in the glandular epithelium in all but one tRCC. The findings of cytokeratin expression of tRCCs were very similar to those of craniopharyngioma. β-Catenin showed nuclear translocation in five cases. All patients with nuclear translocation of β-catenin suffered postoperative re-enlargement.

Conclusions

tRCC carries an extremely high risk of re-enlargement. Cytokeratin expression resembles that in craniopharyngioma, which might indicate a very close origin of these pathologies. Nuclear translocation of β-catenin may be related to the aggressive clinical course.