Presence of store-operated Ca2+ entry in C57BL/6J mouse ventricular myocytes and its suppression by sevoflurane.

BACKGROUND: Store-operated Ca(2+) entry (SOCE) has been implicated in various pathological conditions of the heart including ischaemia/reperfusion and ventricular hypertrophy. This study investigated the effects of sevoflurane on SOCE. METHODS: Fluorescence imaging was performed on fluo-3- and mag-fluo-4-loaded mouse ventricular myocytes to measure the cytosolic and intraluminal sarcoplasmic reticulum (SR) Ca(2+) levels, respectively, using a confocal laser scanning microscope. Whole-cell membrane currents were recorded using the patch-clamp technique. Ventricular myocytes were exposed to thapsigargin and angiotensin II to deplete SR Ca(2+) stores and thereby activate SOCE. RESULTS: The combined application of thapsigargin and angiotensin II to the Ca(2+)-free medium evoked a significant decrease in the SR Ca(2+) levels, which was followed by the elevation of cytosolic Ca(2+) and the development of cellular hypercontracture upon subsequent addition of extracellular Ca(2+). This cytosolic Ca(2+) elevation was inhibited by 2-aminoethoxydiphenyl borate but not by verapamil and KB-R7943, which indicates that SOCE was present in mouse ventricular myocytes. Sevoflurane concentration-dependently inhibited the SOCE-mediated Ca(2+) overload (IC(50) of 137 µM, which corresponds to 0.96%) with a significant reduction occurring at concentrations of ≥2%. Patch-clamp experiments revealed that the SOCE current was also concentration-dependently blocked by sevoflurane (IC(50) of 144 µM, which corresponds to 1.0%). CONCLUSIONS: Sevoflurane at concentrations of ≥2% significantly inhibits the SOCE activity and prevents the resultant cellular Ca(2+) overload that leads to hypercontracture in ventricular myocytes. This inhibitory action may be involved in the cardioprotective effect of sevoflurane against Ca(2+) overload-mediated injury.

A phase II study of amrubicin combined with carboplatin for elderly patients with small-cell lung cancer: North Japan Lung Cancer Study Group Trial 0405.

BACKGROUND: Amrubicin, a new anthracycline agent, has shown high activity for small-cell lung cancer (SCLC) in previous studies. However, a combination regimen with amrubicin and platinum has been investigated little. On the basis of previous phase I study, we conducted this study to evaluate the efficacy and the safety of amrubicin and carboplatin for elderly patients with SCLC. METHODS: Chemotherapy-naive elderly patients with SCLC received amrubicin (35 mg/m(2), days 1-3) and carboplatin [area under the curve (AUC) 4.0, day1] every 3 weeks. The primary end point was overall response rate (ORR), and secondary end points were progression-free survival (PFS), overall survival and toxicity profile. RESULTS: From January 2005 to November 2007, 36 patients were enrolled [median age 76 (range 70-83); ECOG performance status of zero and one in 17 and 19 patients, respectively]. One complete response and 31 partial responses were observed (ORR 89%). Median PFS was 5.8 months and median survival time was 18.6 months. Grade 3-4 neutropenia was observed in 97% of the patients and six patients (17%) suffered from grade 3-4 febrile neutropenia. Other toxic effects were moderate and treatment-related death was not observed. CONCLUSIONS: Amrubicin combined with carboplatin is quite effective for SCLC with acceptable toxic effects even for the elderly population. Further evaluation of this regimen is warranted.

Randomized phase II trial of weekly paclitaxel combined with carboplatin versus standard paclitaxel combined with carboplatin for elderly patients with advanced non-small-cell lung cancer.

BACKGROUND: The optimal platinum doublet regimen in elderly patients with non-small-cell lung cancer (NSCLC) is still uncertain. We conducted a randomized phase II study to compare the efficacy and safety of weekly paclitaxel combined with carboplatin with those of the standard schedule. PATIENTS AND METHODS: Elderly patients (age > or =70 years) with advanced NSCLC were randomly assigned to either the weekly arm {70 mg/m(2) paclitaxel on days 1, 8, and 15 and carboplatin [area under the curve (AUC) = 6] on day 1} or the standard arm [200 mg/m(2) paclitaxel and carboplatin (AUC = 6) on day 1]. The primary end point was the overall response rate (ORR). RESULTS: Eighty-two patients were enrolled. The ORR and median progression-free survival were 55% and 6.0 months for the weekly arm and 53% and 5.6 months for the standard arm. Grade 3/4 neutropenia and peripheral neuropathy were observed in 41% and 0% of the patients in the weekly arm and in 88% and 25% in the standard arm, respectively. CONCLUSIONS: This is the first randomized study that compares the platinum doublet designed specifically for the elderly. Regarding the safety, the weekly regimen was less toxic than the standard regimen and seems to be preferable for elderly patients with advanced NSCLC.

Effects of dietary uridine 5'-monophosphate on immune responses in newborn calves.

When compared with normal milk, bovine colostrum contains a large amount of uridine 5'-monophosphate (UMP) and its derivatives. In the present study, we carried out 2 experiments to determine the effects of dietary UMP (2 g/d) on the immune status of newborn calves. In Exp. 1, newborn Holstein bull calves were fed milk replacer alone (control group) or milk replacer supplemented with UMP (UMP group) from d 4 to 10 after birth. The increase in interferon-gamma concentration by peripheral blood mononuclear cells (PBMC) on d 24 tended to be greater in the UMP group than in the control group (P = 0.06). The IgA concentration of the ileal mucosa was greater in the UMP group than in the control group (P < 0.05), although there was no difference between groups in the jejunal mucosa. In Exp. 2, newborn Holstein bull calves were fed milk replacer alone (control group) or milk replacer supplemented with UMP (UMP group) from d 4 to 56 after birth. The proliferation of PBMC was greater in the UMP group than in the control group on d 14, 28, and 42 (P < 0.01). The increase in interferon-gamma concentration by PBMC was greater in the UMP group than in the control group on d 28 and 42 (P < 0.05). From these results, we concluded that dietary UMP affected the immune responses of newborn calves.

Exotic radiation from a photonic crystal excited by an ultrarelativistic electron beam.

We report the observation of an exotic radiation (unconventional Smith-Purcell radiation) from a one-dimensional photonic crystal. The physical origin of the exotic radiation is direct excitation of the photonic bands by an ultrarelativistic electron beam. The spectrum of the exotic radiation follows photonic bands of a certain parity, in striking contrast to the conventional Smith-Purcell radiation, which shows solely a linear dispersion. Key ingredients for the observation are the facts that the electron beam is in an ultrarelativistic region and that the photonic crystal is finite. The origin of the radiation was identified by comparison of experimental and theoretical results.

Protease susceptibility of the Caulobacter crescentus flagellar hook-basal body: a possible mechanism of flagellar ejection during cell differentiation.

When motile swarmer cells of Caulobacter crescentus differentiate into sessile stalked cells, the flagellum is ejected. To elucidate the molecular mechanism of the flagellar ejection, flagellar hook-basal body (HBB) complexes from C. crescentus were purified and characterized. The purified HBBs were less stable against acidic pH or protease treatment than HBBs of Salmonella typhimurium, supporting the view that flagellar ejection from C. crescentus is initiated by destruction of the fragile basal structures. In addition, protease treatment of the purified flagella resulted in the specific digestion of the MS ring complex, revealing for the first time the intact structure of the whole rod.

Detection of Japanese yam mosaic virus by RT-LAMP.

Arapid and simple procedure is described to detect the genomic RNA molecule of Japanese yam mosaic potyvirus (JYMV). This method, named RT-LAMP, allows direct detection of RNA from infected plants without careful RNA extraction, rapid thermal cycling and gel electrophoresis. RT-LAMP was successfully applied to leaves, propagules and roots of Japanese yam infected with JYMV. One of the characteristics of the RT-LAMP method is its ability to synthesize an extremely large amount of DNA. Accordingly, a large amount of by-product, pyrophospate ion, is produced yielding a white precipitate of magnesium pyrophosphate in the reaction mixture. The presence or absence of this white precipitate allows easy detection of the amplification of JYMV genomic RNA without gel electrophoresis.

Increase in intracellular Ca(2+) and calcitonin gene-related peptide release through metabotropic P2Y receptors in rat dorsal root ganglion neurons.

We examined the effects of the activation of metabotropic P2Y receptors on the intracellular Ca(2+) concentration and the release of neuropeptide calcitonin gene-related peptide (CGRP) in isolated adult rat dorsal root ganglion neurons. In small-sized dorsal root ganglion neurons (soma diameter<30 microm) loaded with fura-2, a bath application of ATP (100 microM) evoked an increase in intracellular Ca(2+) concentration, while the removal of extracellular Ca(2+) partly depressed the response to ATP, thus suggesting that the ATP-induced increase in intracellular Ca(2+) concentration is due to both the release of Ca(2+) from intracellular stores and the influx of extracellular Ca(2+). Bath application of uridine 5'-triphosphate (UTP; 100 microM) also caused an increase in intracellular Ca(2+) concentration in small-sized dorsal root ganglion neurons and the P2 receptor antagonists suramin (100 microM) and pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS; 10 microM) virtually abolished the response, indicating that the intracellular Ca(2+) elevation in response to UTP is mediated through metabotropic P2Y receptors. This intracellular Ca(2+) increase was abolished by pretreating the neurons with thapsigargin (100 nM), suggesting that the UTP-induced increase in intracellular Ca(2+) is primarily due to the release of Ca(2+) from endoplasmic reticulum Ca(2+) stores. An enzyme-linked immunosorbent assay showed that an application of UTP (100 microM) significantly stimulated the release of CGRP and that suramin (100 microM) totally abolished the response, suggesting that P2Y receptor-mediated increase in intracellular Ca(2+) is accompanied by CGRP release from dorsal root ganglion neurons. These results suggest that metabotropic P2Y receptors contribute to extracellular ATP-induced increase in intracellular Ca(2+) concentration and subsequent release of neuropeptide CGRP in rat dorsal root ganglion neurons.

Laparoscopic ultrasonography for resection of insulinomas.

BACKGROUND: There have been few reports on the use of laparoscopic ultrasonography as an aid for the resection of insulinomas. In this study, we review our experience with laparoscopic ultrasonography for the intraoperative localization and resection of insulinomas. METHODS: We attempted laparoscopic resection of insulinomas in 7 patients (median age, 50 years) during a 4-year period. Preoperative imaging showed that 1 of the insulinomas was located in the head of the pancreas, 2 were located in the body, and 4 were located in the tail. RESULTS: We identified the insulinomas in all 7 patients with laparoscopic ultrasonography. In 6 of the patients, the insulinomas were laparoscopically resectable, either by enucleation (4 patients) or by resection of the pancreatic tail (2 patients). Conversion to laparotomy was necessary for the insulinomas in the head of the pancreas because they were close to the portal vein and the major pancreatic duct. All patients showed improvement in their hypoglycemia after the operations. Minor leakage of pancreatic juice occurred in 4 patients, and this was resolved with conservative treatment. CONCLUSIONS: Laparoscopic ultrasonography is useful for the intraoperative localization of insulinomas. Laparoscopy is a safe and feasible technique for resecting insulinomas located in the body or tail of the pancreas.

Somatic mutations of the MEN1 gene and microsatellite instability in a case of tertiary hyperparathyroidism occurring during high phosphate therapy for acquired, hypophosphatemic osteomalacia.

Somatic mutations of the MEN type 1 (MEN1) gene were recently shown to be responsible for tumorigenesis in 13-26% of sporadic, nonfamilial primary hyperparathyroidism. However, it is unknown whether these mutations are also involved in tumorigenesis of parathyroid glands occurring during high phosphate therapy for hypophosphatemic rickets or osteomalacia. A male patient with adult-onset, hypophosphatemic osteomalacia had been treated with 1alpha-OHD3 and oral phosphate for 13 yr when tertiary hyperparathyroidism developed. After total resection of four enlarged parathyroid glands and autotransplantation of a hyperplastic gland, the patient has continued to do well for the last 2 yr. Sequence analysis of the coding exons of MEN1 gene revealed a 36-bp deletion with a 2-bp insertion (exon 2) in the right upper parathyroid gland accompanied with loss of heterozygosity at 11q13 locus and a heterozygous mutation of 2-bp deletion (AG) in exon 10 in the right lower gland, in which microsatellite instability was also found. No MEN1 gene mutation was detected in the other two hyperplastic parathyroid glands or in the peripheral blood. These findings indicate that MEN1 gene mutations contributed to tumorigenesis of the right upper parathyroid gland in this case of phosphate-induced tertiary hyperparathyroidism. Very recently a bone tumor was found in the right femoral neck, and the tumor (chondroblastoma) was resected.

Nerve growth factor prevents apoptosis of cord blood-derived human cultured mast cells synergistically with stem cell factor.

BACKGROUND: Stem cell factor (SCF) has been identified as a critical survival factor of human mast cells. Other cytokines which possess survival promotion activity on human mast cells are less known. OBJECTIVE: We examined the survival promotion activity of nerve growth factor (NGF) on cord blood-derived human cultured mast cells. METHODS: Expression and function of NGF receptors on the mast cells were examined by RT PCR, flowcytometric analysis, immunoprecipitaion and western blotting. The survival promotion activity of NGF to the mast cells was examined. To evaluate the proliferating activity of NGF on the human cultured mast cells, flow cytometric analysis with propidium iodide staining was applied. To confirm whether the human mast cell growth activity of NGF was caused by a suppression of apoptosis, the proportion of the cells containing in situ DNA fragmentation was counted. RESULTS: The human cultured mast cells expressed the high affinity receptor p140trk but not the low affinity receptor p75LNGFR. NGF induced the phosphorylation of p140trk. NGF alone could not support the survival of the mast cells, however, the addition of NGF to the culture medium containing recombinant SCF led to a significant increase of the number of survival mast cells. No significant changes of the cell cycle from G0/G1 phase to the S/G2 + M phases were observed by NGF. In contrast, the addition of NGF to the medium with SCF showed a significant inhibitory effect on the apoptosis of the mast cells. CONCLUSION: NGF may act as a key factor to promote the survival of human mast cells synergistically with SCF through the prevention of apoptosis.

Somatic mutations of the multiple endocrine neoplasia type 1 (MEN1) gene in patients with sporadic, nonfamilial primary hyperparathyroidism.

BACKGROUND: Multiple endocrine neoplasia type 1 (MEN 1) is a syndrome with tumors of many endocrine tissues. Germline MEN1 gene mutations were found in most patients with familial or sporadic MEN 1. Recently, somatic MEN1 gene mutations were also detected in sporadic non-MEN 1 endocrine tumors. METHODS: We used direct sequence analysis to investigate MEN1 gene mutations in 30 parathyroid tumors obtained from 30 patients with sporadic, nonfamilial primary hyperparathyroidism. RESULTS: Four patients had somatic mutations of the MEN1 gene, comprising 1 small insertion (1091insAGC), one missense mutation (G42S), and 2 non-sense mutations (E388X, R460X). Identical missense and non-sense mutations were found in patients with familial and non-familial MEN 1. There were no differences between clinical features of patients with and without MEN1 gene mutations. CONCLUSIONS: The incidence of somatic MEN1 gene mutations (13.3%) in Japanese patients with sporadic, nonfamilial primary hyperparathyroidism is almost equal to those of such patients in the United States and Sweden. Occasionally, the MEN1 gene mutation sites in sporadic parathyroid tumors are identical to those reported in tumors from patients with familial or sporadic MEN 1.

Inhibition of store-operated Ca2+ entry by extracellular ATP in rat brown adipocytes.

1. Modulation of intracellular free Ca2+ concentration ([Ca2+]i) by extracellular ATP was investigated in cultured adult rat brown adipocytes using the fluorescent Ca2+ indicator fura-2. 2. Bath application of ATP in micromolar concentrations caused a large increase in [Ca2+]i in cells previously stimulated with noradrenaline. This ATP-induced [Ca2+]i increase exhibited a monotonic decline to near the resting levels within approximately 2 min, even in the continued presence of the agonist. 3. The magnitude and time course of the [Ca2+]i increase in response to ATP were not significantly affected by removal of extracellular Ca2+, suggesting that a mobilization of intracellular Ca2+ primarily contributes to the increase. 4. The [Ca2+]i increase in response to ATP was sensitive to inhibition by suramin, suggesting the involvement of P2 purinoceptors in the response. 5. Thapsigargin (100 nM) evoked a gradual and irreversible increase in [Ca2+]i which was entirely dependent upon extracellular Ca2+, providing functional evidence for the expression of store-operated Ca2+ entry in these brown adipocytes. 6. Extracellular ATP at a concentration of 10 microM depressed this thapsigargin (100 nM)-induced [Ca2+]i increase by 92 +/- 3 % (n = 8 cells), strongly suggesting that ATP inhibits an influx of Ca2+ across the plasma membrane through the store-operated pathway. Bath application of phorbol 12-myristate 13-acetate (PMA, 5 microM) did not affect the thapsigargin-induced [Ca2+]i increase, indicating that the inhibitory action of ATP is not mediated by activation of protein kinase C (PKC). 7. These results indicate that extracellular ATP not only mobilizes Ca2+ from the intracellular stores but also exerts a potent inhibitory effect on the store-operated Ca2+ entry process in adult rat brown adipocytes.

Human mast cells produce matrix metalloproteinase 9.

Extracellular matrix-destructive enzymes, like matrix metalloproteinases (MMP), have been recognized in the process of inflammation and tissue remodeling and repair. The affected tissues often contain markedly increased numbers of mast cells. Although mast cells are capable of activating latent collagenase and proMMP, it has so far been unknown whether human mast cells themselves produce and secrete MMP9. In this study, MMP9 production by cord blood-derived cultured human mast cells and HMC-1 human mast cells was examined by reverse-transcriptase PCR, gelatin zymography and Western blot analysis using an antibody against MMP9. Cultured mast cells and HMC-1 cells treated with phorbol 12-myristate 13-acetate were shown to express MMP9 mRNA, and the cultured conditioned media from these cells showed gelatinolytic activity, identical with MMP9. Immunohistochemical examination was performed to detect MMP9 in tissue mast cells; mast cells localized in the skin, lung and synovial tissue showed strongly positive reactions for MMP9. Thus, these findings indicate that human mast cells can produce MMP9, which might contribute to extracellular matrix degradation and absorption in the process of allergic and nonallergic responses.

A novel splicing mutation (894-9 G --> A) of the MEN1 gene responsible for multiple endocrine neoplasia type 1.

Germline MEN1 gene mutations are responsible for multiple endocrine neoplasia type 1 (MEN1), a dominantly inherited cancer syndrome. We identified a MEN1 germline mutation 894-9 G --> A in three MEN1 patients from two unrelated families. This mutation was not present in any of the 100 blood samples from normal volunteers. The wild type MEN1 sequence was lost in the patient's pancreatic tumor. Abnormal mRNA was identified in the tumor, which retained an intronic sequence indicating aberrant mRNA splicing at a newly created splicing acceptor site. These findings indicate that this nucleotide substitution is, though previously reported to be a polymorphism, a causative splicing mutation.

Tetrodotoxin-resistant sodium channels of dorsal root ganglion neurons are readily activated in diabetic rats.

To clarify the mechanism of hyperalgesia in diabetic neuropathy, we investigated the effects of streptozocin-induced hyperglycemia on tetrodotoxin-resistant Na+ channel activity of dorsal root ganglion neurons. Experiments were performed on enzymatically isolated neurons of dorsal root ganglia dissected from streptozocin-induced diabetic and their age-matched control rats. Membrane currents were recorded using the whole-cell patch-clamp technique. Mean current density of tetrodotoxin-resistant Na+ channels was significantly larger in neurons prepared from diabetic rats than in control neurons. Tetrodotoxin-resistant Na+ channels were activated at more negative potentials in diabetic than in control neurons. Curves representing the steady-state inactivation and the peak Na+ conductance as a function of membrane potential shifted to the negative side. The changes in gating property of the Na+ channel were observed six weeks after the injection of streptozocin, and still after eight months, indicating that tetrodotoxin-resistant Na+ channel abnormality starts to develop early and persists during the whole period of diabetes. These results suggest that neurons participating in nociception are highly excitable in diabetic animals. The present results may provide an important clue to the elucidation of hyperalgesia in diabetes.

Genotype-phenotype correlation of patients with multiple endocrine neoplasia type 2 in Japan.

BACKGROUND: Multiple endocrine neoplasia type 2 (MEN 2) is a hereditary syndrome characterized by medullary thyroid carcinoma (MTC), pheochromocytoma and hyperparathyroidism. MEN 2 is caused predominantly by germ-line mutations of the RET proto-oncogene. This study aimed to clarify the genotype-phenotype correlation in MEN 2 patients in Japan in order to modify the clinical management according to the genotype. METHODS: Constitutive DNA of 64 MEN 2 patients (48 kindreds) were searched for mutations at exons 10, 11, 13, 14 and 16 of the RET proto-oncogene using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), direct sequencing and restriction enzyme digestion. The clinical characteristics of the patients were obtained from a previous nationwide questionnaire survey. RESULTS: Overall, 62 (96.9%) out of 64 patients had a germ-line point mutation at the hot spots. MTC and pheochromocytoma occurred equally in every genotype except C630S. Specific genotype had a correlation between tumor size and age at the operation for MTC or extent of MTC, i.e. C618S developed late onset type of MTC as compared with that of C634R, C634Y and M918T. Small MTC in C634R may be less aggressive than those in C634Y and M918T. CONCLUSIONS: DNA testing has good clinical implications for the management of patients with MEN 2 and the timing and operative procedures of thyroidectomy can be modified according to the genotype.

Carnoy's fixative reduces the number of chymase-positive cells in immunocytochemical staining of cord-blood-derived human cultured mast cells.

KleinJan et al. (Allergy 1996;51:614-20) reported that Carnoy's fixative reduced the number of chymase-positive mast cells in the nasal mucosa. Therefore, in the present study, we investigated whether Carnoy's fixative reduces the number of chymase-positive cells from cord-blood-derived human cultured mast cells when compared with other types of fixatives. Human mast cells were obtained by culturing cord-blood-derived CD34-positive cells in the presence of stem cell factor and interleukin-6. Staining procedures of the cells in fixation with Carnoy's fixative and with other fixatives gave no differences among the number of tryptase-positive cells, whereas fixation with Carnoy's fixative for 15 min gave a significant decrease in the number of chymase-positive cells compared with acetone for 10 min. The number of chymase-positive cells decreased in a time-dependent manner under fixation with Carnoy's fixative, indicating that Carnoy's fixative had a negative effect on the number of chymase-positive cells from cord-blood-derived human cultured mast cells.

Examination of serum amyloid A protein in kidney transplant patients--comparison of serum amyloid A and C-reactive protein for monitoring the occurrence of renal-allograft-related complications.

Serum amyloid A (SAA) is an inflammation-reactive protein, like C-reactive protein (CRP). In this study, we examined SAA levels in the sera of kidney transplant patients with acute rejection (N = 12), chronic rejection (N = 60) and cytomegalovirus (CMV) infection complications and compared them with serum CRP levels in terms of sensitivity and reactivity. The SAA and CRP showed almost similar kinetics in 10 patients within 2 months of kidney transplantation. However, in 2 patients SAA responded more sensitively to CMV infection and acute rejection. SAA increased significantly 10-fold relative to its baseline levels. The SAA levels also increased along with those of serum creatinine levels. Our experiments clearly showed that SAA and CRP responded sensitively to several stimuli with elevated serum levels including surgical trauma, acute allograft rejection and infection. However, the reactivity and sensitivity of SAA was clearly higher than those of CRP in patients with viral infections, on steroid therapy and undergoing chronic allograft rejection, suggesting that monitoring SAA levels provides more useful information than monitoring CRP.