The secretory ability of newly formed secretory granules is regulated by pro-cathepsin B and amylase in parotid glands.

Parotid glands are exocrine glands that release saliva into the oral cavity. Acinar cells of parotid glands produce many secretory granules (SGs) that contain the digestion enzyme amylase. After the generation of SGs in the Golgi apparatus, they mature by enlarging and membrane remodeling. VAMP2, which is involved in exocytosis, accumulates in the membrane of mature SGs. The remodeling of SG membranes is regarded as a preparation process for exocytosis but its detailed mechanism remains unknown. To address that subject, we investigated the secretory ability of newly formed SGs. Although amylase is a useful indicator of secretion, the cell leakage of amylase might affect the measurement of secretion. Thus, in this study, we focused on cathepsin B (CTSB), a lysosomal protease, as an indicator of secretion. It has been reported that some procathepsin B (pro-CTSB), which is a precursor of CTSB, is initially sorted to SGs after which it is transported to lysosomes by clathrin-coated vesicles. Because pro-CTSB is processed to mature CTSB after its arrival in lysosomes, we can distinguish between the secretion of SGs and cell leakage by measuring the secretion of pro-CTSB and mature CTSB, respectively. When acinar cells isolated from parotid glands were stimulated with isoproterenol (Iso), a ß-adrenergic agonist, the secretion of pro-CTSB was increased. In contrast, mature CTSB was not detected in the medium although it was abundant in the cell lysates. To prepare parotid glands rich in newly formed SGs, the depletion of per-existing SGs was induced by an intraperitoneal injection of Iso into rats. At 5 h after that injection, newly formed SGs were observed in parotid acinar cells and the secretion of pro-CTSB was also detected. We confirmed that the purified newly formed SGs contained pro-CTSB, but not mature CTSB. At 2 h after Iso injection, few SGs were observed in the parotid glands and the secretion of pro-CTSB was not detected, which proved that the Iso injection depleted pre-existing SGs and the SGs observed at 5 h were newly formed after the Iso injection. These results suggest that newly formed SGs have a secretory ability prior to membrane remodeling.

Switching of cargo sorting from the constitutive to regulated secretory pathway by the addition of cystatin D sequence in salivary acinar cells.

The mechanism for segregation of cargo proteins into the regulated and constitutive secretory pathways in exocrine cells remains to be elucidated. We examined the transport of HaloTag proteins fused with full-length cystatin D (fCst5-Halo) or only its signal peptide (ssCst5-Halo) in parotid acinar cells. Although both fusion proteins were observed to be colocalized with amylase in the secretory granules, the coefficients for overlapping and correlation of fCst5-Halo with amylase were higher than those of ssCst5-Halo. The secretion of both the proteins was enhanced by the addition of the ß-adrenergic receptor agonist isoproterenol as well as endogenous amylase. In contrast, unstimulated secretion of ssCst5-Halo without isoproterenol was significantly higher than that of fCst5-Halo and amylase. Simulation analysis using a mathematical model revealed that a large proportion of ssCst5-Halo was secreted through the constitutive pathway, whereas fCst5-Halo was transported into the secretory granules more efficiently. Precipitation of fCst5-Halo from cell lysates was increased at a low pH, which may mimic the milieu of the trans-Golgi networks. These data suggest that the addition of a full-length sequence of cystatin D facilitates efficient selective transport into the regulated pathway by aggregation at low pH in the trans-Golgi network.NEW & NOTEWORTHY The mechanism underlying the segregation of cargo proteins to the regulated and constitutive secretory pathways in exocrine cells remains to be solved. We analyzed unstimulated secretion in salivary acinar cells by performing double-labeling experiments using HaloTag technology and computer simulation. It revealed that the majority of HaloTag with only signal peptide sequence was secreted through the constitutive pathway and that the addition of a full-length cystatin D sequence changed its sorting to the regulated pathway.

Involvement of myristoylated alanine-rich C kinase substrate phosphorylation and translocation in cholecystokinin-induced amylase release in rat pancreatic acini.

Cholecystokinin (CCK) is a gastrointestinal hormone that induces exocytotic amylase release in pancreatic acinar cells. The activation of protein kinase C (PKC) is involved in the CCK-induced pancreatic amylase release. Myristoylated alanine-rich C kinase substrate (MARCKS) is a ubiquitously expressed substrate of PKC. MARCKS has been implicated in membrane trafficking in several cell types. The phosphorylation of MARCKS by PKC results in the translocation of MARCKS from the membrane to the cytosol. Here, we studied the involvement of MARCKS in the CCK-induced amylase release in rat pancreatic acini. Employing Western blotting, we detected MARCKS protein in the rat pancreatic acini. CCK induced MARCKS phosphorylation. A PKC-δ inhibitor, rottlerin, inhibited the CCK-induced MARCKS phosphorylation and amylase release. In the translocation assay, we also observed CCK-induced PKC-δ activation. An immunohistochemistry study showed that CCK induced MARCKS translocation from the membrane to the cytosol. When acini were lysed by a detergent, Triton X-100, CCK partially induced displacement of the MARCKS from the GM1a-rich detergent-resistant membrane fractions (DRMs) in which Syntaxin2 is distributed. A MARCKS-related peptide inhibited the CCK-induced amylase release. These findings suggest that MARCKS phosphorylation by PKC-δ and then MARCKS translocation from the GM1a-rich DRMs to the cytosol are involved in the CCK-induced amylase release in pancreatic acinar cells.

Impending rupture of saphenous vein graft aneurysm with floating fractured bare metal stent treated by coil embolization and covered stent implantation.

Aneurysmal degeneration of a saphenous vein graft (SVG) is a rare, but potentially fatal complication of coronary artery bypass graft (CABG) surgery. In this case report, a patient that had undergone prior CABG surgery and bare metal stent (BMS) implantation at the site of a stenotic SVG lesion presented at our hospital with chest pain, and an SVG aneurysm was detected at the previous BMS implantation site. In addition, the implanted BMS was fractured and floating in the SVG aneurysm. The SVG aneurysm was successfully occluded by percutaneous intervention, using a combination of distal covered stent deployment at the site of the anastomosis between the native coronary artery and the SVG and proximal coil embolization of the aneurysm.

Prevention of mitochondrial disease inheritance by assisted reproductive technologies: prospects and challenges.

BACKGROUND: Mitochondrial diseases are caused by the mutations in both nuclear and mitochondrial DNA (mtDNA) and the treatment options for patients who have mitochondrial disease are rather limited. Mitochondrial DNA is transmitted maternally and does not follow a Mendelian pattern of inheritance. Since reliable and predictable detection of mitochondrial disorders in embryos and oocytes is unattainable at present, an alternative approach to this problem has emerged as partial or complete replacement of mutated mtDNA with the wild-type mtDNA through embryo manipulations. Currently available methods to achieve this goal are germinal vesicle transfer (GVT), metaphase chromosome transfer (CT), pronuclear transfer (PNT) and ooplasmic transfer (OT). SCOPE OF REVIEW: We summarize the state of the art regarding these technologies and discuss the implications of recent advances in the field for clinical practice. MAJOR CONCLUSIONS: CT, PNT and GVT techniques hold promise to prevent transmission of mutant mtDNA through ARTs. However, it is clear that mtDNA heteroplasmy in oocytes, embryos and offspring produced by these methods remains as a legitimate concern. GENERAL SIGNIFICANCE: New approaches to eliminate transmission of mutant mtDNA certainly need to be explored in order to bring the promise of clinical application for the treatment of mitochondrial disorders. This article is part of a Special Issue entitled Biochemistry of Mitochondria, Life and Intervention 2010.

The restorative effects of adipose-derived mesenchymal stem cells on damaged ovarian function.

The clinical application of human adipose-derived mesenchymal stem cells (MSCs) as treatment for intractable diseases or traumatic tissue damage has attracted attention. To address the ability of reactivating injured ovaries, we prepared a rat model with damaged ovaries by using an anticancer agent, cyclophosphamide (CTX). We then investigated the restorative effects on ovarian function and the safety of adipose-derived MSCs (A-MSCs). MSCs were shown to be capable of inducing angiogenesis and restoring the number of ovarian follicles and corpus lutea in ovaries. No deformities, tumor formation or deaths were observed in F1 and F2 rats, indicating that the local injection of MSCs into the ovary did not have any obvious side effects. In addition, the localization of the Y chromosome was investigated using the fluorescent in situ hybridization method by injecting male A-MSCs into the ovaries; as a result, the Y chromosomes were localized not in the follicles, but in the thecal layers. ELISA revealed that A-MSCs secreted higher levels of vascular endothelial cell growth factor (VEGF), insulin-like growth factor-1 (IGF-1) and hepatocyte growth factor (HGF) than tail fibroblast cells. Quantitative real-time PCR and immunohistochemistry showed that higher expression levels of VEGF, IGF-1 and HGF were observed in CTX-treated ovaries after A-MSC transplantation. These findings suggest that MSCs may have a role in restoring damaged ovarian function and could be useful for regenerative medicine.

Sorting of a HaloTag protein that has only a signal peptide sequence into exocrine secretory granules without protein aggregation.

The mechanism involved in the sorting and accumulation of secretory cargo proteins, such as amylase, into secretory granules of exocrine cells remains to be solved. To clarify that sorting mechanism, we expressed a reporter protein HaloTag fused with partial sequences of salivary amylase protein in primary cultured parotid acinar cells. We found that a HaloTag protein fused with only the signal peptide sequence (Met(1)-Ala(25)) of amylase, termed SS25H, colocalized well with endogenous amylase, which was confirmed by immunofluorescence microscopy. Percoll-density gradient centrifugation of secretory granule fractions shows that the distributions of amylase and SS25H were similar. These results suggest that SS25H is transported to secretory granules and is not discriminated from endogenous amylase by the machinery that functions to remove proteins other than granule cargo from immature granules. Another reporter protein, DsRed2, that has the same signal peptide sequence also colocalized with amylase, suggesting that the sorting to secretory granules is not dependent on a characteristic of the HaloTag protein. Whereas Blue Native PAGE demonstrates that endogenous amylase forms a high-molecular-weight complex, SS25H does not participate in the complex and does not form self-aggregates. Nevertheless, SS25H was released from cells by the addition of a ß-adrenergic agonist, isoproterenol, which also induces amylase secretion. These results indicate that addition of the signal peptide sequence, which is necessary for the translocation in the endoplasmic reticulum, is sufficient for the transportation and storage of cargo proteins in secretory granules of exocrine cells.

Involvement of AQP6 in the Mercury-sensitive osmotic lysis of rat parotid secretory granules.

In secretory granules and vesicles, membrane transporters have been predicted to permeate water molecules, ions and/or small solutes to swell the granules and promote membrane fusion. We have previously demonstrated that aquaporin-6 (AQP6), a water channel protein, which permeates anions, is localized in rat parotid secretory granules (Matsuki-Fukushima et al., Cell Tissue Res 332:73-80, 2008). Because the localization of AQP6 in other organs is restricted to cytosolic vesicles, the native function or functions of AQP6 in vivo has not been well determined. To characterize the channel property in granule membranes, the solute permeation-induced lysis of purified secretory granules is a useful marker. To analyze the role of AQP6 in secretory granule membranes, we used Hg²âº, which is known to activate AQP6, and investigated the characteristics of solute permeability in rat parotid secretory granule lysis induced by Hg²âº (Hg lysis). The kinetics of osmotic secretory granule lysis in an iso-osmotic KCl solution was monitored by the decay of optical density at 540 nm using a spectrophotometer. Osmotic secretory granule lysis was markedly facilitated in the presence of 0.5-2.0 µM Hg²âº, concentrations that activate AQP6. The Hg lysis was completely blocked by ß-mercaptoethanol which disrupts Hg²âº-binding, or by removal of chloride ions from the reaction medium. An anion channel blocker, DIDS, which does not affect AQP6, discriminated between DIDS-insensitive and sensitive components in Hg lysis. These results suggest that Hg lysis is required for anion permeability through the protein transporter. Hg lysis depended on anion conductance with a sequence of NO(3) (-) > Br⁻ > I⁻ > Cl⁻ and was facilitated by acidic pH. The anion selectivity for NO(3) (-) and the acidic pH sensitivity were similar to the channel properties of AQP6. Taken together, it is likely that AQP6 permeates halide group anions as a Hg²âº-sensitive anion channel in rat parotid secretory granules.

Oophorectomy for fertility preservation via reduced-port laparoscopic surgery.

BACKGROUND: For fertility preservation of women patients scheduled to undergo chemotherapy or radiotherapy, unilateral oophorectomy was performed, and the ovary was cryopreserved. METHODS: Two-port surgery was conducted in 3 patients, and single-port surgery using a single-incision laparoscopic surgery port in 3. An 18-G Cathelin needle equipped with a syringe was directly inserted transabdominally to reach the small follicle on the ovarian surface; then, follicular fluid was recovered by aspiration through the syringe as with in vitro fertilization procedures, and immature oocytes were collected from the resulting culture medium under microscopy and cryopreserved. Vitrification of the ovarian tissue was performed using the cryotissue method. RESULTS: The operative time and estimated blood loss were 39.7 minutes (17-57) and 8.6 mL (2-20), and the numbers of ovarian cortical tissues and immature oocytes collected were 10.1 (5.5-15) and 16.3 (0-36), respectively. CONCLUSIONS: It is suggested that fertility preservation operations before chemotherapy or radiotherapy can be safely done using reduced-port surgery.

[Outbreak of extensively drug-resistant pulmonary tuberculosis in a hemodialysis facility].

We experienced an outbreak of extensively drug-resistant pulmonary tuberculosis (XDR-TB) in a hemodialysis facility. The primary case involved a 51-year-old male hemodialysis patient, with a history of treatment for Mycobacterium tuberculosis infection seven years previously. There was no drug resistance, and the patient completely recovered after undergoing treatment with isoniazid (INH), rifampicin (RFP) and ethambutol (EB). He was admitted to another hospital due to a recurrence of pulmonary tuberculosis in June 2006. At first, he was treated with HRS [INH, RFP and streptomycin (SM)]; however, the drug regimen was changed to INH, EB, levofloxacin (LVFX) and kanamycin (KM) in August following the results of a drug susceptibility test. Although the patient was receiving outpatient tuberculous therapy, he was readmitted in June 2007 due to relapse and conversion of a sputum culture to positive status. Additionally, the XDR-TB organism was identified. Following these events, five staff members of the hemodialysis facility and a member of the patient's family were diagnosed with XDR-TB infection. The staffs who were infected with XDR-TB had worked in the same dialysis room, drug resistance was found in all cases and drug resistant gene mutations were found in three cases; therefore, we considered this to be an outbreak. As XDR-TB infection was suspected in all cases, no patients took drugs to treat latent tuberculosis infection (LTBI). Regarding the causes of the outbreak, the first is the delay of four months in making a diagnosis of re-exacerbation of tuberculosis. Second, in Case 2, the patient developed laryngeal and tracheobronchial tuberculosis after first being diagnosed with asthma, and the tuberculosis diagnosis was delayed. Third, the sputum smear of Case 2 was strongly positive. There is only one previously reported outbreak of XDR-TB in Japan; therefore, we consider this outbreak to be educational.

Characteristics of iodine-bearing silver-impregnated alumina sorbents and their direct solidification via hot isostatic pressing.

Waste management for radioiodine is a key issue for the sustainable nuclear fuel cycle. The iodine adsorption behavior on a bed column of a silver-impregnated alumina sorbent (AgA) under conditions designed to match those of the Rokkasho reprocessing facility dissolver off-gas (DOG) system was investigated using different volatilized iodine concentrations. Cross-sectional observations of iodine-bearing AgA grains revealed that iodine was adsorbed as silver iodide and silver iodate, and gradually distributed from the surface to the inside of the AgA. The iodine distribution throughout the AgA beds allowed us to estimate the length of the mass-transfer zone. This suggests that the iodine load fraction in AgA (adsorbed iodine/total impregnated silver) will be averaged to 50% in the expected facility equipment design. This study also describes the waste form durability after disposal. To reproduce the average iodine loading in the waste form, 100%-loaded AgA grains were mixed with an equal amount of commercially available alumina reagents and consolidated through hot isostatic pressing at 175 MPa and 1,325°C for 3 h. The resultant 50%-loaded solid was used for the static leaching test over 4.5 years, where the leached iodine was less than 0.2% under simple reducing conditions. This suggested that the HIPed solid of AgA from Rokkasho DOG showed preferable water resistance for after disposal safety.

Acinar Cell Proliferation Promoted by BMP2 in Injured Mouse Parotid Gland: BMP2 Promotes Cell Proliferation in Parotid Gland.

Objective: To identify factors that affect salivary gland recovery, we investigated the expression and function of bone morphogenetic protein 2 (BMP2) in mice. Materials and Methods: Using a micro clip, mice parotid glands were removed 7 days after the ligation of the unilateral parotid excretory duct. Thereafter, they were weighed and stained with hematoxylin and eosin, and BMP2 expression was examined via real-time reverse transcription-polymerase chain reaction. Primary cultures of parotid glands were prepared, and BMP2 protein was added to the culture medium for 48 hr to examine its effect on cell proliferation. E-cadherin and vimentin expression was examined using western blotting. Finally, immunohistochemical staining using an anti-Ki67 antibody was performed. Results: Duct-ligated parotid glands weighed less than those that were collected after sham surgery and showed acinar cell atrophy. They also showed higher BMP2 expression than control glands. Primary-cultured parotid acinar cells supplemented with BMP2 showed higher proliferative potential than control cells. Furthermore, they showed E-cadherin, but not vimentin, expression, and their percentage of Ki67-positive cells were higher than that corresponding to the controls. Conclusions: Injury to salivary glands by excretory duct ligation increased BMP2 expression, which may be involved in maintaining salivary gland function by inducing acinar cell proliferation.

Uterine autotransplantation in cynomolgus macaques: the first case of pregnancy and delivery.

BACKGROUND: For women with congenital uterine infertility, or for those who have undergone hysterectomy, uterine transplantation is one of the potential treatments to regain fertility. In this study, we utilized a primate model of uterine transplantation, and evaluated the patency of our microsurgical anastomoses, and the perfusion of the transplanted uterus. METHODS: Two female cynomolgus monkeys underwent surgery. We anastomosed two arteries and one vein in Case 1 and two arteries and two veins in Case 2. The arteries used were the uterine arteries and the anastomosis was done to the external iliac artery. We used one of the ovarian veins in both animals, but resected the ovary from the Fallopian tube. Uterine arterial blood flow and uterine size were determined by intraoperative indocyanine green (ICG) angiography and ultrasonography. The biopsy of the uterine cervix was performed after surgery. RESULTS: ICG angiography showed that the unilateral uterine artery perfused the bilateral uterine bodies and cervix. In Case 1, ICG angiography showed the occlusion of one of the anastomosed arteries during the operation and the uterus appeared atrophied 2 months after operation. In Case 2, the transplanted uterus survived and normal menstruation occurred. The animal achieved a natural pregnancy and was delivered by the Caeserean section due to early separation of the placenta. The newborn suffered fetal distress. CONCLUSIONS: These results show the anastomosis of at least the bilateral uterine arteries and the unilateral ovarian vein is required for uterus transplantation. This is the first report of a natural pregnancy in a primate following uterine autotransplantation.

Minimal ovarian stimulation combined with elective single embryo transfer policy: age-specific results of a large, single-centre, Japanese cohort.

BACKGROUND: The two main complications associated with the use of assisted reproduction techniques, ovarian hyperstimulation syndrome and multiple pregnancies, could be eliminated by milder ovarian stimulation protocols and the increased use of a single embryo transfer (SET) policy. A retrospective, cohort study was performed in private infertility centre to evaluate the embryological and clinical results of a large exclusively SET program according to patient age (lower or equal 29, 30-34, 35-39, 40-44 and equal or higher 45 years). MATERIALS: A total of 7,244 infertile patients have undergone 20,244 cycles with a clomiphene-based minimal stimulation or natural cycle IVF protocol during 2008. Following oocyte retrieval, fertilization and embryo culture a total of 10,401 fresh or frozen single embryo transfer procedures were performed involving cleavage-stage embryos or blastocysts. RESULTS: Successful oocyte retrieval rate (78.0 %) showed no age-dependent decrease until 45 years. Fertilization (80.3 %) and cleavage (91.1 %) rates were not significantly different between age groups. Blastocyst formation (70.1 % to 22.8 %) and overall live birth rates (35.9 % to 2 %) showed an age-dependent decrease. Frozen-thawed blastocyst transfer cycles gave the highest chance of live birth per embryo transfer (41.3 % to 6.1 %). CONCLUSIONS: High fertilization and cleavage rates were obtained regardless of age whereas blastocyst formation and live birth rates showed an age-dependent decrease. An elective single embryo transfer program based on a minimal ovarian stimulation protocol yields acceptable live birth rates per embryo transfer in infertile patients up until their mid-forties. However in very advanced age patients (equal or higher 45 years old) success rates fall below 1 %.

Short-term, low-dose, non-steroidal anti-inflammatory drug application diminishes premature ovulation in natural-cycle IVF.

A retrospective cohort study was conducted in a private infertility centre to evaluate the use of non-steroidal antiinflammatory drugs (NSAID) in natural-cycle IVF (nIVF) treatment. A total of 1865 first-rank nIVF cycles performed during 2009­2010 were evaluated. Low-dose, post-trigger NSAID was administered in a non-randomized way in cycles at higher ovulation risk where an imminent LH surge was detected on triggering day. Main outcome measures were premature ovulation rate, embryo transfer rate per scheduled cycle and clinical pregnancy and live birth rates per embryo transfer. NSAID use was associated with a significantly lower risk of premature ovulation (3.6% versus 6.8%, adjusted OR 0.24, 95% CI 0.15­0.39, P < 0.0001) and higher embryo transfer rate (46.8% versus 39.5%, adjusted OR 1.38, 95% CI 1.06­1.61, P = 0.012) per scheduled cycle. Clinical pregnancy (39.1% versus 35.9%) and live birth rates per embryo transfer (31.3% versus 31.4%) were comparable. In this retrospective series, short-term low-dose NSAID application positively influenced nIVF cycles by diminishing the rate of unwanted premature ovulations and increasing the proportion of cycles reaching embryo transfer.

Surgical procedure to conserve the uterus for future pregnancy in patients suffering from massive adenomyosis.

The treatment for severe adenomyosis has usually been hysterectomy, because there is no line of demarcation between diseased and normal tissue. Yet many such women wish to retain their uterus and some even wish to bear children. This report evaluates the efficacy of a new method of adenomyomectomy, where adenomyotic tissues are radically excised and the uterine wall is reconstructed by a triple-flap method, without overlapping suture lines, to prevent uterine rupture in subsequent pregnancies. This is a prospective case series followed for 10 years from June 1998 to August 2008 of 104 women with severe adenomyosis verified histologically and with magnetic resonance imaging. There was a dramatic reduction in both dysmenorrhoea and hypermenorrhoea and all patients returned to having normal menstrual cycles. Of 26 women who wished to conceive, 16 became pregnant, 14 (53.8%)went to term and delivered a healthy baby and there were no cases of uterine rupture. Adenomyosis symptoms recurred in only four out of 104 cases. The procedure thus resulted in a dramatic reduction in symptoms and allowed over half of women who wished to conceive to go to term without uterine rupture.

Quinone-dependent D-lactate dehydrogenase Dld (Cg1027) is essential for growth of Corynebacterium glutamicum on D-lactate.

BACKGROUND: Corynebacterium glutamicum is able to grow with lactate as sole or combined carbon and energy source. Quinone-dependent L-lactate dehydrogenase LldD is known to be essential for utilization of L-lactate by C. glutamicum. D-lactate also serves as sole carbon source for C. glutamicum ATCC 13032. RESULTS: Here, the gene cg1027 was shown to encode the quinone-dependent D-lactate dehydrogenase (Dld) by enzymatic analysis of the protein purified from recombinant E. coli. The absorption spectrum of purified Dld indicated the presence of FAD as bound cofactor. Inactivation of dld resulted in the loss of the ability to grow with D-lactate, which could be restored by plasmid-borne expression of dld. Heterologous expression of dld from C. glutamicum ATCC 13032 in C. efficiens enabled this species to grow with D-lactate as sole carbon source. Homologs of dld of C. glutamicum ATCC 13032 are not encoded in the sequenced genomes of other corynebacteria and mycobacteria. However, the dld locus of C. glutamicum ATCC 13032 shares 2367 bp of 2372 bp identical nucleotides with the dld locus of Propionibacterium freudenreichii subsp. shermanii, a bacterium used in Swiss-type cheese making. Both loci are flanked by insertion sequences of the same family suggesting a possible event of horizontal gene transfer. CONCLUSIONS: Cg1067 encodes quinone-dependent D-lactate dehydrogenase Dld of Corynebacterium glutamicum. Dld is essential for growth with D-lactate as sole carbon source. The genomic region of dld likely has been acquired by horizontal gene transfer.

[A case of hard metal lung disease in a man who worked as an iron grinder].

The patient was a man who had suffered from repeated pneumothoraces since August 2003, when he was 16 years old. A right pneumothorax was observed at age 21 years, in April 2008. At the same time, a dry cough began to appear and diffuse small nodular shadows in both lung fields were found on a chest X-ray film. Due to worsening symptoms and the chest X-ray findings, a transbronchial lung biopsy was performed in September 2008. Pathological examination showed mural type organization, and large numbers of multinucleated giant cells that were engulfing nucleated cells and had black pigment in their cytoplasm. Giant cell interstitial pneumonia and hard metal lung disease (HMLD) were suspected because of the patient's occupational history as a metal grinder, which included the use of a hard metal tool for three years since August 2005. In an elementary analysis using an electron probe microanalyzer, tungsten was detected in resected lung tissue obtained in April 2008 which confirmed the diagnosis. His symptoms improved after the initiation of corticosteroid therapy, which continued but with a gradual decrease in the dose. In this case, HMLD developed over a relatively short period despite the low level of dust dispersal of a hard-metal tool, perhaps because of a hypersensitivity of the patient to hard metal.

Suppression of parotid acinar cell dysfunction by the free radical scavenger 3-methyl-1-phenyl-2-pyrazolin-5-one.

Salivary gland atrophy and consequent hyposalivation are serious problems in clinical dentistry, as saliva regulates the environment of the oral cavity. To clarify the mechanisms underlying salivary gland dysfunction, a system for primary culture of parotid acinar cells has been established. It has been reported previously that the process of cell isolation from parotid glands triggers stress signaling mediated by Src and p38 mitogen-activated protein (MAP) kinase (p38), leading to dedifferentiation of acinar cells, and that an nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor suppresses this activation of Src and p38, suggesting that reactive oxygen species initiate the dedifferentiation signal. The present study examined the effect of a free radical scavenger, 3-methyl-1-phenyl-2-pyrazolin-5-one (also termed MCI-186 or edaravone), on activation of the stress signal and the secretory function of parotid acinar cells. Activation of p38 during cell isolation was suppressed by addition of MCI-186. The retention of the activity of amylase, a major salivary protein, and the number of amylase-containing secretory granules were improved by isolation and culture in the presence of MCI-186. In addition, calcium elevation upon stimulation with a muscarinic agonist was higher in MCI-186-treated cells than in untreated cells. These results suggest that MCI-186 (edaravone) is a promising agent for prevention of salivary gland dysfunction.

Bone marrow derived cells are involved in the pathogenesis of cardiac hypertrophy in response to pressure overload.

BACKGROUND: Bone marrow (BM) cells possess broad differentiation potential and can form various cell lineages in response to pathophysiological cues. The present study investigated whether BM-derived cells contribute to the pathogenesis of cardiac hypertrophy, as well as the possible cellular mechanisms involved in such a role. METHODS AND RESULTS: Lethally irradiated wild-type mice were transplanted with BM cells from enhanced green fluorescent protein-transgenic mice. The chimeric mice were subjected to either prolonged hypoxia or transverse aortic constriction. BM-derived enhanced green fluorescent protein-expressing cardiomyocytes increased in number over time, emerging predominantly in the pressure-overloaded ventricular myocardium, although they constituted <0.01% of recipient cardiomyocytes. To determine whether BM-derived cardiomyocytes were derived from cell fusion or transdifferentiation at the single-cell level, lethally irradiated Cre mice were transplanted with BM cells from the double-conditional Cre reporter mouse line Z/EG. BM-derived cardiomyocytes were shown to arise from both cell fusion and transdifferentiation. Interestingly, BM-derived myofibroblasts expressing both vimentin and alpha-smooth muscle actin were concentrated in the perivascular fibrotic area. These cells initially expressed MAC-1/CD14 but lost expression of these markers during the chronic phase, which suggests that they were derived from monocytes. A similar phenomenon occurred in cultured human monocytes, most of which ultimately expressed vimentin and alpha-smooth muscle actin. CONCLUSIONS: We found that BM-derived cells were involved in the pathogenesis of cardiac hypertrophy via the dual mechanisms of cell fusion and transdifferentiation. Moreover, the present results suggest that BM-derived monocytes accumulating in the perivascular space might play an important role in the formation of perivascular fibrosis via direct differentiation into myofibroblasts.