Empagliflozin attenuates arrhythmogenesis via inhibition of O-GlcNAcylation in diastolic phase of diabetic cardiomyopathy

Background

Diabetic cardiomyopathy is an important complication of diabetes mellitus (DM) and reported to increase the risk of fatal ventricular arrhythmias. Recent clinical trials showed that empagliflozin (EMPA), a selective sodium-glucose co-transporter 2 (SGLT2) inhibitor, improved cardiovascular outcomes regardless of the presence of diabetes and the traditional cardiovascular risk factors. Despite the promising benefit of EMPA on heart failure treatment, its beneficial effect in the context of anti-arrhythmic therapy has not been fully examined. We therefore aimed to examine anti-arrhythmic effect of acute EMPA treatment especially onto calcium (Ca2+) handling in diabetic cardiomyocytes.

Methods

We assessed echocardiography, hemodynamic study, electrophysiology, Ca2+ handling and protein expression in C57BLKS/J-leprdb/db mice (db/db mice), a leptin receptor-deficient model of obesity and Type 2 diabetes, and their non-diabetic lean heterozygous Leprdb/+ littermates (db/+ mice).

Results

The 16-week-old db/db mice had preserved systolic function but exhibited diastolic dysfunction. In arrhythmia induction using ex-vivo Langendorff-perfused hearts, db/db mice showed a significantly increased premature ventricular complex (PVC) by 2x Ca2+ and 1μM isoproterenol load than control, which was attenuated by EMPA perfusion (1 μM). Diabetic cardiomyocytes showed an increased frequency of spontaneous Ca2+ sparks and waves, and decreased Ca2+ transient amplitude and sarcoplasmic reticulum (SR) Ca2+ content. Ca2+ transient decay tau and time to 50% decay were significantly prolonged in diabetic cardiomyocytes. These data indicating the impaired Ca2+ handling in diabetic cardiomyocytes were normalized by acute administration of EMPA (1 μM), while the administration of NHE inhibitor (Cariporide 10 μM) did not show significant differences. In the protein expression analysis, CaMKII Thr287 autophosphorylation and CaMKII-dependent RyR2 S2814 phosphorylation were significantly increased in diabetic hearts, which were inhibited by short-term (30 min) perfusion of EMPA (1 μM). The expressions of SERCA2a and phospholamban were not significantly different among three groups. Lastly, whole hearts O-GlcNAcylation, one of the important post translational modifications, was significantly reduced by EMPA treatment.

Conclusion

EMPA improved intracellular Ca2+ handling and attenuated arrhythmogenesis in mice with diabetic cardiomyopathy at the diastolic dysfunction phase, suggesting that EMPA may exhibit this anti-arrhythmic effect by normalization of intracellular calcium handling via inhibiting O-GlcNAcylation.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Boehringer Ingelheim

Comparison of contrast-enhanced transabdominal ultrasonography following endoscopic ultrasonography with GD-EOB-DTPA-enhanced MRI for the sequential diagnosis of liver metastasis in patients with pancreatic cancer

PURPOSE

To compare contrast-enhanced transabdominal ultrasonography (CE-US) following contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) with enhanced magnetic resonance imaging using gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (EOB-MRI) in the diagnosis of liver metastases in patients with pancreatic cancer.

METHODS

Patients who underwent contrast-enhanced computed tomography for possible pancreatic cancer and required further evaluation with CH-EUS were enrolled in this study, and the diagnostic performance of CE-US following CH-EUS for liver metastasis was compared with that of EOB-MRI.

RESULTS

A total of 228 patients were included in the final analysis. Two hundred thirty-four hepatic lesions were found in 81 patients, and 178 lesions were finally diagnosed as metastases. EOB-MRI had a higher sensitivity (0.837 vs 0.949), while CE-US had a higher specificity and positive predictive value (PPV) (0.982 and 0.993 vs 0.911 and 0.971, respectively) in the diagnosis of liver metastasis. CE-US with defect reperfusion imaging had a higher diagnostic performance than EOB-MRI (0.866 vs 0.667) in the differentiation between liver metastasis and abscess.

CONCLUSION

EOB-MRI had a higher sensitivity than CE-US for diagnosing liver metastasis in patients with pancreatic cancer, but CE-US following CH-EUS demonstrated a higher specificity and PPV than EOB-MRI and was especially useful in the differentiation between liver metastasis and abscess.

Neuronal nitric oxide synthase inhibition exacerbates atrial electrical remodeling via small-conductance Ca2+-activated K+ channel activation

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): The Japan Society for the Promotion of Science KAKENHI

Background

The presence of atrial fibrillation (AF) is associated with electrical remodeling processes that promote a substrate for the maintenance of AF itself. Small conductance Ca2+-activated K+ (SK) channels; K+-selective and voltage-independent ion channels are key factors in the atrial electrical remodeling (2, 3). However, the mechanism of its activation remains unclear. A recent study showed that neuronal nitric oxide synthase (nNOS) expression and activity are reduced in AF patients and that nNOS depletion causes the abbreviation of action potential duration (APD), leading to increased AF inducibility in animal experiments (4). Decreased NO production, especially driven by nNOS inhibition, might play a key role in the atrial electrical remodeling, and the downstream alteration of SK channels might result from this process.

Purpose

We aimed to evaluate the potential of SK channel blocking to mitigate abnormal electrophysiological properties and the inducibility of atrial tachyarrhythmia (ATA) which was induced by nNOS depletion, and to describe the related mechanism.

Methods

Atrial tachyarrhythmia induction and optical mapping were performed in perfused rat hearts. nNOS was pharmacologically inhibited by S-methylthiocitrulline (SMTC, 100 nM). The influence of the SK channel was examined by a specific channel inhibitor, apamin (100 nM). APD, conduction velocity, and calcium transient (CaT) parameters (CaTD, rise time, time to 50% decay, and tau) were evaluated by voltage and calcium dual optical mapping. Dominant frequency was evaluated to analyze the wave dynamics of AF.

Results

SMTC increased the inducibility of ATA and apamin mitigated the nNOS inhibition-induced arrhythmogenicity (0% [0/7] vs 62% [8/13] vs 15% [2/13] in control, SMTC and SMTC + apamin). SMTC caused the abbreviation and enhanced spatial dispersion of APD, which were reversed by apamin. In contrast, conduction velocity was not affected by SMTC or apamin. Moreover, apamin reduced the dominant frequency of SMTC-induced ATA. In voltage and calcium optical mapping, STMC and apamin did not alter the parameters associated with CaT, however, SMTC caused the abbreviation of APD, which was reversed by apamin (APD80: 48.4 ± 2.7 msec in control group, 30.8 ± 1.5 msec in SMTC group, p <0.0001 vs. control, 41.8 ± 1.5 msec in SMTC + apamin, p = 0.01 vs. SMTC by One-way ANOVA and Tukey’s multiple-comparison test) (Figure A-C).

Conclusion

Acute nNOS inhibition abbreviated APD via activating SK channels. A specific SK channel blocker mitigated APD abbreviation without the alteration of CaT, implying an underlying mechanism of post translational modification of SK channels.

Collision Tumors of Gastric Adenocarcinoma and Mucosa-associated Lymphoid Tissue Lymphoma

A 65-year-old woman with a history of treatment for splenic marginal zone B-cell lymphoma and gastric mucosa-associated lymphoid tissue (MALT) lymphoma underwent esophagogastroduodenoscopy. A reddish elevated lesion was found in the fundus of the stomach. On image-enhanced endoscopy, several findings, such as glandular structures of varying sizes suggesting well-differentiated adenocarcinoma, pruned blood vessels, and dilated blood vessels in deeper mucosa suggesting MALT lymphoma, were observed. The final pathological diagnosis after surgical resection was collision tumors of well-differentiated adenocarcinoma and MALT lymphoma. The features of both tumors could be observed simultaneously with image-enhanced endoscopy.

Suppression of ventricular arrhythmia by mitochondrial calcium uptake via mitochondrial calcium uniporter in the ischemic heart failure mice

Background

In heart failure (HF), diastolic calcium (Ca) leak from sarcoplasmic reticulum (SR) via ryanodine receptor (RyR) causes delayed after depolarization (DAD), leading ventricular arrhythmias (VAs). Recent study reported that Ca uptake into mitochondria via mitochondrial calcium uniporter (MCU) suppress Ca waves (CaWs) and DAD in catecholaminergic polymorphic ventricular tachycardia, in which diastolic Ca leak is thought to be a major cause of VAs as in HF. However, such anti-arrhythmic effect of mitochondrial Ca uptake via MCU remains unclear in HF.

Purpose

We sought to investigate whether mitochondrial Ca uptake via MCU decreases CAWs and VAs incidence in ischemic HF mice.

Methods

Ten-week-old male C57BL/6J mice were divided into 2 groups; sham operation mice (Sham) or HF mice (HF) in which myocardial infarction was induced by left coronary artery ligation. After 4–6 weeks, cardiomyocyte or mitochondria was isolated respectively from the myocardium of Sham and the non-infarct myocardium of HF. Influence of MCU activation on Ca dynamics, VA inducibility and left ventricular hemodynamics were evaluated using Kaemenpferol, a MCU activator. Intracellular Ca dynamics and mitochondrial Ca uptake were measured in isolated cardiomyocytes loaded with Fluo-4 AM on an epifluorescence microscopy and by estimating the extra-mitochondrial Ca reduction with Fluo-5N on a spectrofluoro-photometer, respectively. VAs was induced by programmed stimulation in the Langendorff perfused hearts. Left ventricular (LV) pressure was measured using a microtip transducer catheter. Finally, the effect of intravenous administration of Kaempferol (5mg/kg) on hemodynamic parameters was examined 30 minutes after administration in Sham and HF.

Results

HF mice showed left ventricular dysfunction, as well as the increased heart and lung weights compared to Sham. MCU protein expression in cardiomyocytes did not differ between Sham and HF. Kaempferol increased mitochondrial Ca uptake in the isolated mitochondria both in Sham and HF. The number of the diastolic CaWs was higher in HF compared to Sham. Such increased number of CaWs in HF was attenuated by 10 μM Kaempferol, which was, however, abolished by a MCU blocker Ruthenium Red. The incidence of induced VA was significantly higher in HF than Sham, which was suppressed by Kaempferol. In vivo measurements, intravenous administration of Kaempferol did not show significant changes in hemodynamic parameters in Sham and HF mice.

Conclusions

Mitochondrial Ca uptake via MCU suppresses CaWs and VAs, but did not change LV hemodynamics in HF. Whereas traditional antiarrhythmic drugs have limited use in heart failure patients, a novel strategy that promotes Ca uptake into mitochondria might be a new and safer option for treating VAs in HF.

Funding Acknowledgement

Type of funding source: None

The Propagation Display Method Improves the Reproducibility of Pancreatic Shear Wave Elastography

Evaluation of the pancreatic elastic modulus (PEM) using shear wave elastography (SWE) requires at least 5 measurements to ensure reproducibility. The aim of this study was to evaluate improvement in reproducibility of SWE, using the propagation display method in normal pancreas ([NP] phase 1) and to examine the differences in PEM between NP and chronic pancreatitis (CP), intraductal papillary mucinous neoplasm (IPMN) and autoimmune pancreatitis ([AIP] phase 2). In phase 1, the measurement success rate, median PEM in repeated measurements and appropriate number of SWE measurements were determined in 109 cases with NP. In phase 2, PEM was measured in CP (n = 10), IPMN (n = 31) and AIP (n = 5), using the required number of SWE measurements determined in phase 1. In phase 1, the measurement success rate was 93.9% (92/109 cases). The median PEM for NP was 14.6 kPa and the appropriate number of SWE measurements was at least 3. In phase 2, the median PEMs in CP, IPMN and AIP were 19.6, 18.1 and 17.2 kPa, respectively, with significant differences between NP and CP (p = 0.0133) and between NP and IPMN (p = 0.0436). Use of the propagation display method in SWE improves the reproducibility of measurement of PEM.

Increased hardness of the underlying pancreas correlates with the presence of intraductal papillary-mucinous neoplasm in a limited number of cases

PURPOSE

Pancreatic fibrosis or fibrosing reactions have been reported in intraductal papillary-mucinous neoplasm (IPMN) patients. We assessed whether a higher elastic modulus (EM) measured using shear wave elastography (SW-EG) correlated with the existence of branch-duct (BD) IPMN.

METHODS

In total, 183 normal pancreas (NP) and 123 BD-IPMN cases were enrolled. First, we assessed the difference in pancreatic EM (PEM) at different sites (head or tail side of the cyst). Second, a comparison was done between the median PEM of the NP and the BD-IPMN cases. Receiver-operating characteristic analysis was performed to determine the BD-IPMN diagnostic capabilities. Finally, in patients whose cyst was not visualized, the test-positive rate was determined.

RESULTS

No significant difference was seen between the cyst head side PEM (4.61 kPa) and the tail side PEM (5.35 kPa) (P = 0.471). Among these cases matched by age, 73 were selected each from NP and BD-IPMN cases (median age 65 years). The median PEM of the BD-IPMN cases (5.18 kPa) was significantly higher than that of the NP cases (3.17 kPa) (P < 0.001). When the cut-off value was set at 4.75 kPa, the sensitivity, specificity, PPV, NPV, and accuracy were 75.3%, 64.4%, 72.3%, 67.9%, and 69.9%, respectively. The cut-off value of 4.75 kPa helped for the indirect selection of BD-IPMN patients (10/17, 58.8%) whose cyst was not detected on B-mode ultrasonography.

CONCLUSION

SW-EG measurement of the underlying pancreatic parenchyma may correlate with the presence of BD-IPMN.

Increase in breath hydrogen concentration was correlated with the main pancreatic duct stenosis

BACKGROUND

Hydrogen is produced from unabsorbed carbohydrates in the intestine through degradation and metabolism by hydrogenase of intestinal bacteria. The hydrogen is then partially diffused into blood flow and released and detected in exhaled breath. Pancreatic juice production is decreased in patients with reduced pancreatic exocrine function, including those with pancreatic cancer, thus decreasing digestion and absorption of nutrients including carbohydrates, which may increase undigested carbohydrates in the intestine and increase breath hydrogen concentration (BHC). The aim of this study was to investigate the association between BHC and pancreatic diseases.

METHODS

A retrospective study was designed and 68 patients underwent morning fasting breath hydrogen test. Since there is no clear standard, normal BHC, the median of the measured values from the subjects (9 ppm) was adopted as the standard. The subjects were classified into those with a value exceeding the median (BHC high group: 32 patients) and a value equal to or below the median (BHC low group: 36 patients). Patients characteristics, blood test results and imaging findings characteristic of pancreatic diseases were compared between the groups.

RESULTS

The age was significantly higher (P = 0.010) and the incidences of pancreatic ductal adenocarcinoma and autoimmune pancreatitis were significantly higher (P = 0.018 and P = 0.004, respectively) in the BHC high group. With respect to the blood test items, the Alb level was significantly lower in the BHC high group (P = 0.005). With respect to the characteristic imaging findings of pancreatic diseases, the proportions of patients with pancreatic enlargement, the main pancreatic duct (MPD) stenosis, and the MPD dilatation were significantly higher in the BHC high group (P = 0.022, P < 0.001, and P = 0.002, respectively). On univariate analysis, only the MPD stenosis was extracted as an independent factor (P = 0.014).

CONCLUSION

It was suggested that the fasting BHC is associated with pancreatic diseases causing stenosis of the MPD, including pancreatic cancer (UMIN000020777).

Quantitative diagnosis of chronic pancreatitis using EUS elastography

BACKGROUND

It is difficult to diagnose chronic pancreatitis (CP) objectively because of a lack of standard diagnostic criteria. Endoscopic ultrasonography (EUS) has been used to assess the severity of CP, but the diagnosis of CP using EUS depends on an endosnonographer. The aim of this study was to establish an objective diagnostic method for CP using EUS elastography (EUS-EG).

METHODS

A retrospective study was designed and 96 patients underwent EUS-EG for follow-up of known CP, or who were clinically suspected as having CP. CP patients were categorized CP patients as 4 stages using the Rosemont classification (RC). EUS-EG was performed and the "Mean value", which was negatively correlated with pancreatic fibrosis, was calculated using histogram analysis.

RESULTS

The "Mean value" of each RC stage (normal, indeterminate for CP, suggestive of CP, and consistent with CP) was 90.1 ± 19.3, 73.2 ± 10.6, 63.7 ± 14.2, and 56.1 ± 13.6, respectively, and showed significant differences for each stage (p < 0.001). There was a significant negative correlation between the "Mean value" and the number of EUS features (r _s = -0.59, p < 0.001). Multiple linear regression analysis was used to assess the diagnostic finding of the "Mean value" and showed that hyperechoic foci with shadowing and lobularity with honeycombing maintained their independent diagnostic findings.

CONCLUSIONS

EUS-EG was an objective diagnostic apparatus for CP and provided objective information to support EUS features.

IL-17 eliminates therapeutic effects of oral tolerance in murine airway allergic inflammation

BACKGROUND

Oral tolerance is a classically used strategy for antigen-specific systemic immunotherapy. However, the roles of IL-17 in modification of oral tolerance are not yet understood.

OBJECTIVE

To define the effects of IL-17 on the modification of oral tolerance, the effects of transfer of Th17 cells, administration of IL-17 or anti-IL-17 antibody (αIL-17Ab) to a murine allergic airway inflammation model were investigated.

METHODS

Mice sensitized to and challenged with OVA, received OVA feeding, followed by OVA challenges. Transfer of Th17 cells, administration of IL-17 or αIL-17Ab were executed during OVA feeding. Airway hyperresponsiveness (AHR), airway inflammation, Th2 cytokine response and lung pathology were assessed.

RESULTS

Administration of IL-17 as well as transfer of Th17 cells aggravated AHR and airway allergic inflammation as compared with the findings in mice subjected to OVA feeding alone, whereas administration of αIL-17Ab ameliorated AHR and airway eosinophilia. The effects of Th17 transfer were presumably attributable to augmentation of endogenous IL-6 production in gut. The number of Foxp3-positive regulatory T (Treg) cells in lungs and Payer's patches was increased in the OVA fed mice, whereas the number of these cells was decreased in the mice subjected to OVA feeding + Th17 cell transfer. Neutralization of IL-6 by monoclonal antibody in the mice subjected to OVA feeding + transfer of Th17 cells restored the effects of oral tolerance.

CONCLUSIONS AND CLINICAL RELEVANCE

These data suggest that IL-17 may inhibit the induction of tolerance to antigen through, at least in part augmenting IL-6 production, thereby suppressing the expansion of Treg cells.

[A case of ischemic colitis induced by hypereosinophilic syndrome]

A 58-year-old man came to our hospital, complaining of diarrhea and bloody stool of about 2 weeks' duration. Colonoscopic examination showed mucosal edema and bleeding, and irregular ulcer in the transverse colon and sigmoid colon. Laboratory data indicated elevated WBC (22300/mm(3)) and CRP (11.93mg/dl), and hypereosinophilia (30%). We diagnosed ischemic colitis with thrombosis due to hypereosinophilic syndrome. He started medication with prednisolone and heparin. However, after 15 days, he underwent emergency surgery because of perforation of the sigmoid colon. Thrombosis is associated with a high incidence of hypereosinophilia. It is important to consider the possibility of ischemic colitis associated with hypereosinophilic syndrome.

A prostacyclin agonist with thromboxane inhibitory activity for airway allergic inflammation in mice

BACKGROUND

ONO-1301 is a novel drug that acts as a prostacyclin agonist with thromboxane A(2) (TxA(2)) synthase inhibitory activity. We investigated the effect of ONO-1301 on development of airway allergic inflammation.

METHODS

Mice sensitized and challenged to ovalbumin (OVA) received ONO-1301, OKY-046 (TxA(2) synthase inhibitor), beraprost, a prostacyclin receptor (IP) agonist, ONO-1301 plus CAY10449 (selective IP antagonist) or vehicle during the challenge period. Twenty-four hours after the OVA challenge, airway hyperresponsiveness (AHR) to methacholine was assessed and bronchoalveolar lavage was performed. Lung specimens were excised for goblet cell staining and analysis of lung dendritic cells (DCs). Bone marrow-derived dendritic cells (BMDCs) were generated, in the presence or absence of drugs, for analysis of DC function.

RESULTS

Mice that received ONO-1301 showed significantly lower AHR, airway eosinophilia, T-helper type 2 cytokine levels, mucus production and lung DCs numbers than vehicle-treated mice. These effects of ONO-1301 were mostly reversed by CAY10449. BMDCs treated with ONO-1301 alone showed lower DC functions, such as expression of costimulatory factors or stimulation to spleen T cells.

CONCLUSIONS

These data suggest that ONO-1301 may suppress AHR and airway allergic inflammation through modulation of DCs, mainly mediated through the IP receptor. This agent may be effective as an anti-inflammatory drug in the treatment of asthma.

Inhibitory role of eosinophils on cell surface plasmin generation by bronchial epithelial cells: inhibitory effects of transforming growth factor beta

Eosinophilic bronchitis is an essential component of bronchial asthma, and eosinophils play an important role. We studied the effect of eosinophils on cell surface plasmin generation by bronchial epithelial cells, because plasmin is thought to be involved in bronchial tissue repair/remodeling by means of fibrinolysis and the activation of proteases such as matrix metalloproteases. Plasmin was generated from exogenous plasminogen on the cell surface of cultured bronchial epithelial cells, NCI-H292. Transforming growth factor beta (TGF-beta) treatment resulted in reduced cell surface plasmin generation and a large increase in plasminogen activator inhibitor-type 1 (PAI-1) antigen production in NCI-H292 cells, whereas no conspicuous effects were observed with IL-1 beta and TNF alpha treatment (regulators in pulmonary epithelial cells). On the other hand, this cell surface plasmin generation was reduced by co-incubation with Eol-1, an eosinophil cell line. The addition of TGF-beta antisense and anti-TGF-beta antibodies attenuated this adverse effect of Eol-1 cell co-incubation. These data suggest that eosinophils play an inhibitory role on cell surface plasmin generation by bronchial epithelial cells by means of the up-regulation of PAI-1 expression induced by TGF-beta. Therefore, the accumulation of eosinophils in bronchial walls is thought to be involved in bronchial tissue repair/remodeling in asthma through this protease network.

Erythropoietin induces the expansion of c-kit+ progenitors for myeloid and erythroid cells, but not for lymphoid cells, in the bone marrow and liver

In humans, the numbers of erythrocytes and granulocytes, but not that of lymphocytes, tend to increase in parallel. To determine the mechanism, we investigated how the administration of erythropoietin induces the expansion of erythroid cells and other lineage cells in the bone marrow, liver, and other organs of mice. When mice were injected twice (days 1 and 2) with erythropoietin at a dose of 20 or 200 IU/day/ mouse, a prominent expansion of TER 19+ (erythroid cells) and Gr-1high cells (granulocytes) occurred in the liver, spleen, and bone marrow day 3 after the initial injection. On the other hand, lymphoid cells, including NK cells, extrathymic T cells, and conventional T cells, did not expand. In parallel with the expansion of erythroid cells and granulocytes, the levels of c-kit(+)Lin- cells increased in the liver and bone marrow. Despite the increase in the proportion of c-kit(+) Lin(-) cells, the generation of lymphocytes (e.g., T cells) decreased when such bone marrow cells were injected to scid mice. These results suggest that erythropoietin has the ability to induce the expansion of not only erythroid cells but also granulocytes in the liver, spleen, and bone marrow. Furthermore, c-kit+ progenitors which may commit themselves to erythroid and myeloid cells, but not to lymphoid cells, were also activated in the liver and bone marrow of mice treated with erythropoietin.

Mice with early onset of death (EOD) due to lupus glomerulonephritis

Both MRL-lpr/lpr (lpr) and BXSB mice fall victim to autoimmune disease as a function of age. To combine their properties, brother-sister mating of (female lpr x male BXSB)F1 mice was done. Mice for mating were selected according to indicators of early onset of glomerulonephritis and subsequent early death (i.e., EOD). This mating was continued for more than 16 generations. The EOD mice thus established had homozygous H-2k/k, lpr/lpr, and possible yaa/- (in the case of males). The average life span of males was 83 days while that of females was 126 days. After 12 weeks of age, the majority (> 80%) of male EOD mice were characterized by the abnormality of urine due to glomerulonephritis. We then characterized how glomerulonephritis was evoked, especially in terms of expanding lymphocyte subsets in various immune organs. Similar to the case of parental lpr mice, the major expanding cells were CD4-8-B220+ TCRint cells in the immune organs and kidney. In addition, myeloid cells were found to infiltrate the kidney. This massive infiltration of both TCRint cells and myeloid cells might be responsible for the onset of acute glomerulonephritis. Even after more than 50 generations, these EOD mice still carry both lpr and yaa genes. These results suggest that EOD mice might be a very useful tool for the study of acute lupus glomerulonephritis which is evoked by the genetic abnormalities.

Abundance of NKT cells in the salivary glands but absence thereof in the liver and thymus of aly/aly mice with Sjögren syndrome

It is known that ALY/Nsc Jcl-aly/aly (aly/aly) mice that congenitally lack lymph nodes fall victim to Sjögren syndrome as a function of age. We investigated how TCRint cells of extrathymic origin and TCRhigh cells of thymic origin are distributed in various organs of these mice. Although the distribution of T-cell subsets was not different between control aly/+ and aly/aly mice in youth in any of the tested organs, the proportion of TCRint cells in the liver and spleen of aly/aly mice increased with aging. Usually, TCRint cells in the liver comprise a half-and-half mixture of a NK1. 1(+) subset (i.e., NKT cells) and a NK1.1(-) subset. In constrast, almost all expanding TCRint cells in various immune organs of aly/aly mice were found to be NK1.1(-). A large proportion of lymphocytes, including NK cells and TCRint cells, were also present in the salivary glands of aly/aly mice. Interestingly, these TCRint cells in the salivary glands contained an NK1.1(+) subset (i.e., NKT cells) that used an invariant chain of Valpha14Jalpha281 for TCRalphabeta (>50%). Moreover, gammadeltaT cells that used Vgamma 1, 2, 4/Vdelta 1, 4, 6 mRNAs, different from those of gammadeltaT cells in the liver and intestine, were abundant. Possibly reflecting the in situ generation of these T cells in the salivary glands, the expression of RAG-2 mRNA was evident by the RT-RCR method. These results suggest that (i) inflammatory lymphocytes that evoke Sjögren syndrome in aly/aly mice are NK cells or TCRint cells (both NK1.1(+) and NK1.1(-) subsets) and (ii) TCRint cells in the salivary glands might be generated in situ.

Enrichment of c-kit+ Lin- haemopoietic progenitor cells that commit themselves to extrathymic T cells in in vitro culture of appendix mononuclear cells

The appendix as well as the small intestine have recently been found to carry c-kit+ stem cells which give rise to extrathymic T cells. In this study, the properties of c-kit+ stem cells in the appendix of mice were further characterized. When appendix mononuclear cells (MNC) were cultured in the presence of stem cell factor, interleukin-3, interleukin-6 and erythropoietin on a methylcellulose culture plate, the population of c-kitdull Lin- and that of c-kithi Lin- cells expanded. Morphological study revealed that these c-kithi Lin- cells were basophilic granular cells (possibly mast cells). Both populations of cultured appendix MNC were then injected into severe combined immunodeficient mice or cultured with Tst-4 thymic stroma cells. These in vivo and in vitro studies demonstrated that c-kitdull Lin- cells were oligopotent haemopoietic progenitor cells which gave rise to extrathymic T cells, while c-kithi Lin- cells lacked haemopoietic progenitor cell activity. In contrast to c-kit+ stem cells in the bone marrow, those in the appendix did not give rise to myeloid cells and conventional thymic T cells under any of the conditions tested. The present results suggest that the appendix primarily comprises c-kit+ cells which give rise to basophilic granular cells and extrathymic T cells and that such c-kit+ cells have the ability to replicate themselves in culture in vitro.

Expansion of CD56+ NK T and gamma delta T cells from cord blood of human neonates

A particular T cell population expressing NK cell markers, CD56 and CD57, exists in humans. Many CD56+ T and CD57+ T cells (i.e. NK T cells) exist in the liver and increase in number in the blood with ageing. They may be a human counterpart of extrathymic T cells, similar to NK1.1+ CD3int cells seen in mice. We investigate here the existence of such NK T cells in human cord blood and the in vitro expansion of these cells by the stimulation of human recombinant IL-2 (rIL-2). There were very small populations (< 1.0%) of CD56+ T cells, CD57+ T cells, and gamma delta T cells in cord blood. However, all of these populations increased in number after birth and with ageing. When lymphocytes in cord blood were cultured with rIL-2 (100 U/ml) for 14 days, CD56+ T cells expanded up to 25% of T cells. CD57+ T cells were never expanded by these in vitro cultures. The expansion of gamma delta T cells (mainly V gamma9- nonadult type) also occurred in the in vitro culture. A considerable proportion of CD56+ T cells was found to use V alpha24 (i.e. equivalent to invariant V alpha14 chain used by murine NK T cells) for TCR alpha beta. These results suggest that neonatal blood contains only a few NK T cells but CD56+ NK T cells and gamma delta T cells are able to expand in vitro.

Differentiation of forbidden T cell clones and granulocytes in the parenchymal space of the liver in mice treated with estrogen

Estrogen was administered to B6 (NK1.1+ strain), BALB/c (Mls-1b2a, V beta 3+ cells being forbidden clone), or (B6 x BALB/c) F1 mice (1 mg/mouse). On days 3 and 10, the number of cells yielded by the liver doubled, whereas that yielded by the thymus decreased prominently. The numbers of cells in the spleen, bone marrow, and blood were unchanged. c-kit+ stem cells, which give rise to multilineage cells, were present in the liver and bone marrow. The proportion of such c-kit+ cells in the liver increased while that in the bone marrow decreased on day 3. Therefore, the absolute number of c-kit+ stem cells increased severalfold in the liver and clusters of lymphoid cells became visible in the parenchymal space. At that time, the expression of recombination activating gene-1 and -2 mRNAs became prominent. Reflecting these phenomena, the number and proportion of IL-2R beta+ CD3int cells (i.e., primordial T cells) increased in the liver on days 3 and 10. An increase in the number of proportion of such CD3int cells was seen even in the thymus and uterus. In parallel with the increase of CD3int cells, the proportion of granulocytes also increased in various organs on day 3. Forbidden clones were present in either the NK1.1+ or the NK1.1- subset of CD3int cells in (B6 x BALB/c) F1 mice treated with estrogen and liver mononuclear cells in such mice acquired potent cytotoxicity against syngeneic thymocytes. These results reveal that estrogen has the ability to potentiate the generation of self-reactive T cells and granulocytes in the liver and other organs.

Expansion of an unusual population of Gr-1+CD3int cells in the lymph nodes and other peripheral organs of mice carrying the lpr gene

Granulocytes and extrathymic T cells are often activated simultaneously, but they are absolutely separate populations in normal mice. However, some abnormal extrathymic T cells (i.e., CD3int cells) seen in mice carrying the lpr gene were found to express a granulocyte marker, Gr-1. Such mice include MRL-lpr/lpr mice and SCG mice. In parallel with an age-associated increase of IL-2Rbeta(low)CD3int cells which contained double-negative CD4-8- and B220+CD2- cells, Gr-1+CD3int cells increased in number in the lymph nodes and other peripheral organs. In addition to a major population of IL-2Rbeta(low)CD3int cells, there is a small population of IL-2Rbeta(high)CD3int cells which produce normal Fas mRNA and Fas molecule from the lpr gene. It was found that both IL-2Rbeta(low)CD3int and IL-2Rbeta(high)CD3int cell populations contained Gr-1+ cells. IL-2Rbeta(high)CD3int cells tended to contain a higher proportion of Gr-1+ cells than did IL-2Rbeta(low)CD3int cells. More interestingly, Gr-1+CD3int cells expressed a considerable level of mRNA of the mG-CSF receptor, similar to granulocytes. The present study thus yielded further information on an unusual property of abnormally expanding CD3int cells in mice carrying the lpr gene.

[Experimental study on interdigestive migrating contractions with intestinal transection and injection of Ringer solution into intestine]

The occurrence and mechanism of IMC are still not completely elucidated. Base on the conjecture of that the region of intestine and its ingredients may be concerning with the conduction mechanism of IMC, following experiment was performed by author. Small intestine was cut into two parts. Anal side was closed as blind end, and the end of oral side was sutured to colon or anal part of intestine by end to side anastomosis. Gastric fistula and intestinal fistula of the blind ending intestine were also made, and six pieces of force transducers were sutured to the serosa of the intestine in order to observe the movement of intestine. Under non-anesthesia and non-restricted condition for whole day long, Ringer solution was injected into gastric or intestinal fistula by 50 ml one shot or continuous dripped infusion of 250 ml per hour. The result is: In upper part of intestine, the appearance of IMC in oral and anal side of intestine is continuously observed. However, in lower part of intestine, the IMC of oral and anal part of intestine appeared completely independent without any continuity. And, as one shot of 50 ml of Ringer solution was injected, the conduction of IMC was suppressed but still observable, while continuously infused of 250 ml/hr, the IMC was completely disappeared.

New additional operation for the prevention of the gastric stasis after selective gastric vagotomy with antrectomy

In order to prevent postoperative gastric stasis, we devised and tested the following improvements in the selective gastric vagotomy with antrectomy. (1) The gastroduodenostomy was made so as to have an acute angle to the longitudinal axis of the remnant stomach, and (2) the downward traction being exerted on the remnant stomach by the transverse colon was eliminated by dissecting the greater omentum, and then (3) the posterior wall of the corpus on the lesser curvature side was fixed to the stump of the hepatogastric ligament, and the posterior wall of the corpus on the greater curvature side was fixed to the retroperitoneum inferior to the pancreas. By these procedures, the corpus was maintained in a position superior to the anastomosis. These operative procedures resulted in preventing the gastric stasis after the start of oral feeding. The two patients on whom this operation was performed have been followed up for 3 to 4 months since the operation, and neither of them has had any complaint of gastric stasis, such as anorexia or a feeling of heaviness of the stomach.

Alterations in myocardial perfusion during painless ST-segment depression in patients with angina pectoris

In order to determine whether painless ST changes represent myocardial ischemia, we studied regional myocardial perfusion in patients with angina pectoris who showed painless ST-segment depression during a treadmill exercise test. Twenty-one patients were evaluated by myocardial imaging using thallium-201 injected intravenously during exercise when painless ST-segment depression was evident. The same examination was repeated in 5 of the above patients when they showed ST-segment depression with chest pain. Myocardial images obtained during painless ST-segment depression revealed perfusion defects in 15 of 21 patients (71%). Images obtained during ST-segment depression with chest pain showed perfusion defects in all 5 patients (100%) including 3 patients who demonstrated no defects during painless ST-segment depression. In these 5 patients, the ST-segment depression associated with pain was significantly greater than that without pain (3.4 +/- 1.1 vs 2.1 +/- 1.1 mm, p less than 0.01). These results suggest that the majority of episodes of painless ST-segment depression occurring during exercise are accompanied by regional myocardial perfusion abnormalities and that transient painless ST-segment depression in patients with angina pectoris might represent less severe myocardial ischemia.