Use of adipose tissue-derived stromal cells for prevention of esophageal stricture after circumferential EMR in a canine model

BACKGROUND

EMR is an accepted treatment for early esophageal carcinoma. However, resection of a large mucosal area often causes postoperative esophageal stricture.

OBJECTIVE

To investigate the efficacy of autologous adipose tissue-derived stromal cells (ADSCs) for prevention of stricture formation after EMR in dogs.

DESIGN

Animal study.

SETTING

University research center.

INTERVENTION

Ten beagle dogs were randomized into a control group and an ADSCs-injected (ADSC) group. The ADSCs were isolated from autologous adipose tissue. Immediately after circumferential esophageal EMR, about 5 × 10(6) ADSCs suspended in 8 mL of phosphate-buffered saline solution were injected endoscopically into the residual submucosa of the ADSC group, whereas the control group received only 8 mL of phosphate-buffered saline solution.

MAIN OUTCOME MEASUREMENTS

Dysphagia score, weight loss, rate of mucosal constriction, and histologic assessments.

RESULTS

In the control and ADSC groups, the median dysphagia scores were 4 and 1 (P < .043), the mean degrees of mucosal constriction were 75.7% and 45.3% (P < .008), and the numbers of nascent microvessels in the submucosal layer were 7.4 and 16.2 per unit area (P = .007), respectively. Atrophy and fibrosis of the muscularis propria layer were observed in the control group.

LIMITATIONS

Animal study, small sample size.

CONCLUSION

Injection therapy with autologous ADSCs suppresses constriction of the esophageal mucosa and improves clinical symptoms after circumferential EMR in this canine model.

Reduction of whole PTH/intact PTH ratio as a predictor of bone metabolism in cinacalcet treatment of hemodialysis patients with secondary hyperparathyroidism

In cinacalcet treatment of hemodialysis (HD) patients with secondary hyperparathyroidism (SHPT), not only intact parathyroid hormone (I-PTH), whole PTH (W-PTH), and bone markers, but also W-PTH/I-PTH ratio as proportion of active PTH(1-84) molecules were decreased. Changes in W-PTH/I-PTH ratio significantly correlated and predicted changes in bone marker.

INTRODUCTION

Cinacalcet partly suppresses the secretion of PTH by enhancing PTH(1-84) degradation into N-truncated fragments. The objectives of this study is to investigate the significance of the N-truncated PTH/PTH(1-84) ratio for the prediction of the effect of cinacalcet in HD patients.

METHODS

Serum parameters were measured during 12 weeks of oral cinacalcet administration at 25 mg daily in 39 HD patients with SHPT.

RESULTS

Serum Ca, Pi, W-PTH, I-PTH, and W-PTH/I-PTH ratio all decreased significantly in a time-dependent manner during cinacalcet administration. Serum tartrate-resistant acid phosphatase (TRAP) 5b reflected these changes more precisely than serum N-telopeptide of type-I collagen. At 1 week, changes in I-PTH and W-PTH correlated significantly with those in serum Pi, but not Ca. Changes in serum Pi (but not Ca) and serum W-PTH also correlated significantly with changes in serum TRAP5b at both 4 and 12 weeks, while changes in serum I-PTH correlated significantly with those in serum TRAP5b only at 12 weeks. Changes in the serum W-PTH/I-PTH ratio correlated significantly with those in serum TRAP5b at both 4 and 12 weeks, and changes in serum W-PTH/I-PTH ratio at 4 weeks showed a tendency for a correlation with changes in serum TRAP5b at 12 weeks. HD patients with a reduced W-PTH/I-PTH ratio after 4 weeks had a significantly greater reduction of TRAP5b over 12 weeks.

CONCLUSION

W-PTH and the W-PTH/I-PTH ratio allow estimation of the potency of cinacalcet in enhancement of PTH degradation, and thus no less reliable markers than I-PTH for reflecting cinacalcet-induced bone resorption.

Poor muscle quality rather than reduced lean body mass is responsible for the lower serum creatinine level in hemodialysis patients with diabetes mellitus

BACKGROUND

The serum creatinine level is significantly lower in well-nourished hemodialysis patients with diabetes mellitus (DM) than in their non-DM counterparts, despite the presence of anuria in these patients. The factors associated with this finding have not been determined.

PATIENTS AND METHODS

We evaluated the association of serum creatinine with handgrip strength (HGS) and lean body mass index (LMI) in a cross-sectional study of 102 DM and 208 non-DM hemodialysis patients to determine if poorer muscle quality in DM patients could explain the reduced level of serum creatinine. All the DM patients were well-nourished. Grip dynamometry and dual-energy X-ray absorptiometry (DXA) were used to measure HGS and LMI, respectively.

RESULTS

The DM patients had a significantly lower serum creatinine level and HGS compared to the non-DM patients, but whole-body LMI and LMI of the upper limbs did not differ between the two groups of patients. The DM patients had significantly lower serum creatinine/whole-body LMI, serum creatinine/arm LMI, HGS/whole-body LMI, and HGS/arm LMI ratios. The serum creatinine level was significantly correlated with HGS and with whole-body and upper limb LMI in both groups of patients. However, regression analyses of LMI with serum creatinine and HGS gave significantly shallower slopes for the DM patients compared to the non-DM patients.

CONCLUSION

This suggests that the muscle strength generated per unit of muscle mass, which is reflected well by the serum creatinine level, is significantly reduced in DM hemodialysis patients. Therefore, our results show that the significantly lower serum creatinine levels in DM hemodialysis patients compared to non-DM hemodialysis patients may be explained by poor muscle quality rather than by reduced muscle mass or malnutrition.

CD133 expression in rectal cancer after preoperative chemoradiotherapy

CD133-positive cells have been reported to possess a cancer-initiating-cell phenotype and the property of resistance to chemoradiation therapy in colorectal cancer. The aim of the present study was to evaluate quantitative and locational changes in CD133-positive cells in rectal cancer patients who received preoperative chemoradiation therapy. The prognostic significance of CD133 expression in patients with preoperative chemoradiation therapy was also analyzed. Immunohistochemical staining for CD133 and cancer-initiating-cell marker CD44 were performed in 92 surgically resected rectal cancers. Of the 92 cases, 43 patients received preoperative chemoradiation therapy and 49 patients underwent surgery alone. Forty pretherapic biopsy specimens from 43 patients in preoperative chemoradiation therapy group were also analyzed. CD133-positive cases were more common in the preoperative chemoradiation therapy group than in the surgery-alone group (P = 0.03). Further, CD133-positive cases were more common in the preoperative chemoradiation therapy group than in pretherapic biopsy specimens (P = 0.02). In the preoperative chemoradiation therapy group, the CD133-positive cases showed poorer prognosis than the CD133-negative cases. On the other hand, the frequency of CD44-positive case within cancer tissue was similar between the preoperative chemoradiation therapy group and the surgery-alone group. CD44 expression in the preoperative chemoradiation therapy group was not associated with prognosis. CD44- and CD133-positive cells were distributed evenly within the tumor both in the preoperative chemoradiation therapy group and surgery-alone group, and locational alteration was not observed. The therapy-resistant ability of CD133-positive cells can be associated with poor outcome in the patients with preoperative chemoradiation therapy.

Oncologic outcome of intersphincteric resection for very low rectal cancer

BACKGROUND

In 2000 we launched a prospective program of intersphincteric resection (ISR) for very low rectal cancer. In this study we compared the oncologic outcome of patients who underwent ISR with the outcome of patients who underwent abdominoperineal resection (APR).

METHODS

The data of 202 patients with very low rectal cancer who underwent curative ISR (n = 132) or curative APR (n = 70) between 1995 and 2006 were analyzed. Patients were divided into ISR and APR groups. Survival and local recurrence were investigated in both groups.

RESULTS

The median follow-up was 40 months in the ISR group and 57 months in the APR group. The 5-year local relapse-free survival rate was 83% in the ISR group and 80% in the APR group (p = 0.364), and the 5-year disease-free survival rate was 69% in the ISR group and 63% in the APR group (p = 0.714).

CONCLUSIONS

For very low rectal cancers, ISR appears to be oncologically acceptable and can reduce the number of APRs.

Rac is involved in the interkinetic nuclear migration of cortical progenitor cells

The small GTPase Rac regulates neuronal behavior, but whether it also functions in neural progenitor cells has not yet been explored. Here we report that Rac contributes to the regulation of nuclear migration in neocortical progenitor cells. Rac1 is expressed by progenitor cells in a unique spatiotemporal pattern. Cross-sectional immunohistochemical examination revealed intense Rac1 immunoreactivity at the ventricular surface. Similar staining patterns were obtained by immunofluorescence for a Rac-activator, Tiam1, and by reactions to detect the GTP-bound (active) form of Rac. En face inspection of the ventricular surface revealed that apical Rac1 localization was most frequent in M-phase cells, and the endfeet of cells in other cell cycle phases also showed apical Rac1 distribution at lower frequencies. To ask whether progenitor cell behavior prior to and during M phase is Rac-dependent, we monitored individual DiI-labeled progenitor cells live in the presence of a Rac inhibitor, NSC23766. We observed significantly retarded adventricular nuclear migration, as well as cytokinesis failures. Similar inhibitory effects were obtained by forced expression of a dominant-negative Rac1. These results suggest that Rac may play a role in interkinetic nuclear migration in the developing mouse brain.

The unfolded protein response is activated in differentiating epidermal keratinocytes

The unfolded protein response (UPR), which is induced by stress to the endoplasmic reticulum (ER), is involved in the functional alteration of certain cells, such as the differentiation of B cells to plasma cells. The aim of this study is to determine whether the UPR is activated during epidermal keratinocyte (KC) differentiation. Here, we show that the expression of the UPR-induced proteins Bip/GRP78 and HRD1 was increased in cells in the supra-basal layers of normal human epidermis that contain KCs undergoing differentiation as well as in skin-equivalent cultured KCs. However, Bip/GRP78 and HRD1 were poorly expressed in proliferating KCs in squamous cell carcinoma and psoriasis vulgaris tissues. The epidermal growth factor receptor tyrosine kinase inhibitor, PD153035, which induces KC differentiation, upregulated UPR-induced marker mRNAs and proteins. Furthermore, microarray analyses and quantitative PCR revealed that ER stress-inducing reagents, tunicamycin (TU), thapsigargin, and brefeldin A, altered the expression of genes essential for human epidermal KC differentiation, including C/EBPbeta, KLF4, and ABCA12 in vitro. However, ABCA12 and KLF4 mRNA did not increase with TU treatment after siRNA-mediated knockdown of XBP-1. Taken together, our findings strongly suggest that the UPR is activated during normal epidermal KC differentiation and induces C/EBPbeta, KLF4, and ABCA12 mRNAs.

Glycemic control and survival of diabetic hemodialysis patients--importance of lower hemoglobin A1C levels

AIMS

The significance of hemoglobin A1C (HbA1C) on the survival of diabetic hemodialysis patients still remains controversial. We investigated the impact of HbA1C on the survival.

METHODS

A total of 122 diabetic patients on maintenance hemodialysis (age, 59.9+/-11.9 years [mean+/-SD]; hemodialysis duration: 53+/-38 months) were surveyed (survey period: 46+/-19 months).

RESULTS

The cumulative survival of the poor glycemic control group (mean HbA1C of 3-month period > or =6.3%, n=62) was significantly lower than that of the good group (HbA1C<6.3%, n=60), as determined by Kaplan-Meier estimation (P=0.0084, log-rank test). Kaplan-Meier analysis also demonstrated that both cardiovascular and non-cardiovascular mortalities were higher in the poor group than in the good group (P=0.0545 and P=0.0453, respectively). In a multivariate Cox proportional hazard model, the mean HbA1C was a significant predictor of survival (OR 1.260 per 1.0%, 95% CI 1.020-0.579, P=0.0325).

CONCLUSIONS

Poor glycemic control is an independent predictor of poor prognosis in diabetic hemodialysis patients. HbA1C is a clinically useful parameter for identifying the risk for mortality, both for cardiovascular and non-cardiovascular mortality, and that careful management of glycemic control by use of HbA1C is important.

Generation of a transgenic rabbit model of retinal degeneration

PURPOSE

To generate a transgenic (Tg) rabbit model of retinal degeneration and to characterize the pattern of degeneration by using histology and electrophysiology.

METHODS

Rhodopsin Pro347Leu Tg rabbits were generated by BAC transgenesis. Tg rabbits were identified by Southern blot analysis, and the expression levels were measured by quantitative RT-PCR. Retinal histology was examined by light and electron microscopy and immunohistochemistry. Retinal function was assessed by full-field electroretinograms (ERGs).

RESULTS

Six lines of Tg rabbits were generated, and two lines with higher levels of expression showed rod-dominant progressive retinal degeneration. Retinal histology indicated a marked regional variation in the loss of photoreceptors with the central retina more severely affected than the peripheral retina. The characteristics of the ERGs of transgenic rabbits indicated that the rod components of the ERGs were reduced to only 5% by 48 weeks, whereas the cone components remained at 35% in the wild-type at the same time point. The retinal ultrastructure of Tg rabbits showed a large number of small vesicles that accumulated in the extracellular space of the photoreceptors.

CONCLUSIONS

To the best of the authors' knowledge, this is the first rabbit model of progressive retinal degeneration. Because rabbits have large eyes and are easy to handle and breed, they will provide a useful animal model for the study of the pathophysiology of and new treatments for retinal degeneration.

Non-oxidative glucose disposal is reduced in type 2 diabetes, but can be restored by aerobic exercise

Whole-body glucose utilization consists of mitochondrial glucose oxidation and non-oxidative glycogen synthesis. We examined whether reduction of both non-oxidative glucose disposal and glucose oxidation contributes to insulin resistance in type 2 diabetes. We also examined the effects of exercise on these two components. Whole-body glucose disposal rate (GDR, mg/kg/min) was evaluated in 37 type 2 diabetic (T2DM) and 17 non-diabetic (non-DM) subjects as the mean of glucose infusion rate during steady state in the euglycaemic-hyperinsulinaemic clamp study. Glucose oxidation rates were assessed by indirect calorimetry, and non-oxidative GDR was calculated by subtracting glucose oxidation rate from GDR. Intramyocellular lipid (IMCL) content of the soleus muscle was measured using (1)H-magnetic resonance spectroscopy. In 10 T2DM subjects, the changes in oxidative and non-oxidative glucose disposal during clamp were examined after 3-month exercise intervention. GDR (2.93 +/- 1.55 vs. 4.55 +/- 1.83, p = 0.001) and non-oxidative GDR (1.45 +/- 1.52 vs. 3.01 +/- 1.87, p = 0.002) were significantly lower in T2DM than in non-DM subjects. Glucose oxidation rate was comparable in the two groups, and inversely correlated with IMCL (n = 15, r =-0.565, p = 0.028). GDR (2.28 +/- 1.67 to 4.63 +/- 2.42, p = 0.021) and non-oxidative GDR (0.72 +/- 1.27 to 2.26 +/- 1.91, p = 0.047) were increased after exercise intervention, although the change in glucose oxidation rate was not significant. In summary, reduction of non-oxidative glucose disposal may contribute to decreased whole-body glucose utilization. In addition, exercise improves insulin resistance mainly by increasing non-oxidative glucose disposal in type 2 diabetes.

Association of increased active PTH(1-84) fraction with decreased GFR and serum Ca in predialysis CRF patients: modulation by serum 25-OH-D

As the serum calcium and glomerular filtration rate decreased, the proportion of active PTH(1-84) molecules in PTH immunoreactivity increased in serum from predialysis uremic patients, particularly those with vitamin D insufficiency.

INTRODUCTION

The PTH(1-84) fraction was altered in predialysis patients with chronic renal failure (CRF).

METHODS

Serum PTH in predialysis CRF patients without any medication was measured by PTH(1-84)-specific whole PTH assay and intact PTH assay cross-reacting with N-truncated PTH.

RESULTS

In CRF patients, the glomerular filtration rate (GFR) correlated positively with serum Ca and 1,25-dihydroxyvitamin D (1,25(OH)(2)D), and inversely with serum Pi, log intact PTH, and log whole PTH. In multiple regression analysis, including age, gender, body mass index, GFR, Ca, and Pi and 1,25(OH)(2)D as independent variables, serum Ca and GFR associated significantly with serum log whole PTH and intact PTH. Serum log whole PTH/intact PTH ratio, which increased as serum Ca and GFR decreased, retained a negative correlation in those with serum 25-hydroxyvitamin D levels below 20 ng/ml, but not in those above 20 ng/ml. The ratio also correlated positively with serum log tartrate-resistant acid-phosphatase-5b, log cross-linked N-telopeptide of type-I collagen, and log bone alkaline-phosphatase.

CONCLUSION

As GFR declined with suppression of serum Ca, the proportion of active PTH molecules increased in predialysis CRF patients, particularly those with vitamin D insufficiency.

Photopic electroretinograms of mGluR6-deficient mice

PURPOSE

To study the properties of the photopic electroretinograms (ERGs) of the metabotropic glutamate receptor subtype 6 (mGluR6)-deficient mice and to investigate the contribution of cone ON-and OFF-pathways to the mouse photopic ERGs.

METHODS

Photopic ERGs were recorded from mGluR6-deficient and wild-type mice. Photopic ERGs were also recorded after an intravitreous injection of cis-2,3 piperidine dicarboxylic acid (PDA) to block the transmission of signals from the photoreceptors to the OFF-bipolar cells, horizontal cells, and other inner retinal neurons.

RESULTS

The amplitude of the b-wave of the photopic ERG was severely reduced in mGluR6-deficient mice, but a small, slow, positive component was seen after the a-wave. Intravitreous injection of PDA eliminated this positive component.

CONCLUSIONS

The mGluR6-deficient mouse is a useful animal model to study the contribution of the ON-and OFF-pathways to the mouse ERG.

Survey of the morphogenetic dynamics of the ventricular surface of the developing mouse neocortex

To understand the morphogenetic dynamics of the inner surface of the embryonic pallial (neocortical) wall, we immunohistochemically surveyed the cellular endfeet facing the lateral ventricle and found that the average endfoot area was minimal at embryonic day (E)12 in mice. This endfoot narrowing at E12 may represent a change in the mode of cell production at the surface from a purely proliferative mode that retains all daughter cells to a more differentiation-directed mode that allows some daughter cells to leave the surface. The apices of cells undergoing mitosis were 1.5-3.9 times larger than the overall cell apices and 6.7-8.7 times smaller than the cross-sectional area of mitotic somata. En face time-lapse monitoring of each endfoot permitted observation of its cell cycle-dependent size changes, division, and relationships with neighboring endfeet. Planar divisions oriented along the lateral-medial axis were less abundant than those oriented along the rostral-caudal axis at E10 and E11, but basal body distribution in each endfoot was random.