Efficacy of Coronary Sinus Pacing for Cardiogenic Shock Due to Percutaneous Coronary Intervention-induced Sick Sinus Syndrome: Two Case Reports

We herein report two cases of atrial pacing with coronary sinus (CS) pacing performed to improve hemodynamic instability in cardiogenic shock due to percutaneous coronary intervention (PCI)-induced sick sinus syndrome (SSS). Ventricular pacing alone made it difficult to stabilize hemodynamics due to SSS, which had been caused by the lack of reflow and slow flow of the sinus node artery (SNA) jailed with a stent. Adding atrial pacing with CS pacing may be useful, as in our two cases, where ventricular pacing alone was unable to stabilize hemodynamics.

A novel extracorporeal cardiopulmonary resuscitation strategy using a hybrid emergency room for patients with pulseless electrical activity

BACKGROUND

Whether extracorporeal cardiopulmonary resuscitation (ECPR) is indicated for patients with pulseless electrical activity (PEA) remains unclear. Pulmonary embolism with PEA is a good candidate for ECPR; however, PEA can sometimes include an aortic disease and intracranial haemorrhage, with extremely poor neurological outcomes, and can thus not be used as a suitable candidate. We began employing an ECPR strategy that utilised a hybrid emergency room (ER) to perform computed tomography (CT) before extracorporeal membrane oxygenation (ECMO) induction from January 2020. Therefore, the present study aimed to evaluate the effectiveness of this ECPR strategy.

METHODS

Medical records of patients who transferred to our hybrid ER and required ECPR for PEA between January 2020 and November 2021 were reviewed.

RESULTS

Twelve consecutive patients (median age, 67 [range, 57-73] years) with PEA requiring ECPR were identified in our hybrid ER. Among these patients, nine were diagnosed using an initial CT scan (intracranial haemorrhage (3); cardiac tamponade due to aortic dissection (3); aortic rupture (2); and cardiac rupture (1)), and unnecessary ECMO was avoided. The remaining three patients underwent ECPR, and two of them survived with favourable neurological outcomes. Patients not indicated for ECPR were excluded before ECMO induction.

CONCLUSION

Our ECPR strategy that involved the utilisation of a hybrid ER may be useful for the exclusion of patients with PEA not indicated for ECPR and decision making.

Successful interhospital transfer for extracorporeal cardiopulmonary resuscitation of a patient who had a cardiac arrest after cesarean section

Background

Studies describing the effectiveness of extracorporeal cardiopulmonary resuscitation (ECPR) for peripartum cardiopulmonary arrest are lacking.

Case Presentation

A 39‐year‐old woman underwent elective cesarean section. Right after surgery, she fell into a cardiac arrest and was promptly transferred to our institute by ambulance. On arrival, we immediately initiated ECPR, within 63 min of the cardiac arrest. Return of spontaneous circulation was achieved 80 min after induction of extracorporeal membrane oxygenation. As the hemodynamics of the patient stabilized, extracorporeal membrane oxygenation was discontinued on day 3 of hospitalization. The patient’s cerebral performance category score was 3 at discharge, which improved to 2 after 3 months.

Conclusion

This case suggests that prompt interhospital transfer and ECPR might be effective for peripartum cardiac arrest due to nonhemorrhagic events.

Impact of the Antithrombotic Effects of Prasugrel on Mid-Term Vascular Healing in Acute Coronary Syndrome vs. Stable Coronary Artery Disease

BACKGROUND

The impact of antiplatelet drug effects on mid-term local arterial responses following percutaneous coronary intervention (PCI) remains uncertain. We evaluated the impact of the platelet reactivity of prasugrel on mid-term vascular healing between acute coronary syndrome (ACS) and stable coronary artery disease (CAD).Methods and Results:We conducted a prospective, 12-center study in 125 patients with ACS and 126 patients with stable CAD who underwent PCI with an everolimus-eluting stent (EES) and received dual antiplatelet therapy (DAPT) with prasugrel and aspirin. Serial optical coherence tomography (OCT) was performed immediately after PCI and at the 9-month follow-up to assess the association of P2Y₁₂reaction units (PRU) with the frequency of malapposed or uncovered struts and intrastent thrombi (IST). The incidence of abnormal mid-term OCT findings did not different between the ACS and CAD arms, regardless of clinical presentation, except that uncovered struts were more frequent in the ACS than CAD arm. PRU at PCI was significantly associated with the frequency of IST at follow-up, but not with uncovered and malapposed struts. PRU at PCI was the only independent predictor of IST detected at follow-up (odds ratio 1.009).

CONCLUSIONS

In patients undergoing EES implantation and receiving prasugrel, achieving an adequate antiplatelet effect at the time of stent implantation may regulate thrombus formation throughout the follow-up period.

Rescue Pericardial Drainage and Return Connected to ECMO for Aortic Rupture into the Pericardial Sac with Acute Type A Aortic Dissection

We present the first documented case of emergent pericardial drainage and return (PD-R) under extracorporeal membrane oxygenation (ECMO) for the management of aortic rupture into the pericardial sac caused by acute type A aortic dissection (AADA). An 83-year-old woman collapsed during an elective coronary intervention. ECMO was eventually required. Acute accumulation of pericardial effusion with aortic dissection was revealed by echocardiography. Percutaneous pericardial drainage was performed using a drainage line connected to the venous line of the ECMO system to maintain blood flow and blood pressure. After stabilization of the patient’s hemodynamics, immediate aortic repair was successfully performed and the patient was discharged with no neurological deficit. In cases of massive amounts of pericardial drainage and persistent hemorrhagic shock due to aortic rupture with AADA, PD-R connected to ECMO is useful while waiting for aortic repair.

Impact of dual antiplatelet therapy with adjusted-dose prasugrel on mid-term vascular response in patients undergoing elective percutaneous coronary intervention with everolimus-eluting stents

The impact of dual antiplatelet therapy (DAPT) with adjusted-dose (3.75 mg/day) prasugrel for Japanese patients has not been fully investigated in terms of local arterial healing following the elective percutaneous coronary intervention (PCI). The ROUTE-01 elective study was a prospective, 12-center and single-arm registry that enrolled 123 patients who underwent elective PCI with everolimus-eluting stents (EESs) under DAPT with a combination of adjusted-dose prasugrel and aspirin. Serial optical coherence tomography (OCT) was performed at the index PCI and 9-month follow-up to assess the relationship between in-stent thorombus (IST) and residual platelet reactivity measuring platelet reactivity unit (PRU). The patients were classified as extensive, intermediate, and poor metabolizers by cytochrome P450 2C19 (CYP2C19) loss-of-function polymorphisms. The prevalence of IST was 9.0% by 9-month OCT, with no difference amongst the three groups (p = 0.886). The incidences of malapposed and uncovered struts were not different among the groups. PRU was not statistically different among the groups. In multivariate logistic regression analysis, the independent predictor for IST on 9-month OCT was irregular protrusion (odds ratio = 8.952, p = 0.037) on post-PCI OCT, not CYP2C19 loss-of-function polymorphisms. An adequate anti-thrombotic effect with an acceptable incidence of IST was observed irrespective of CYP2C19 loss-of-function polymorphisms. Our data suggests that adjusted-dose prasugrel and aspirin is a feasible treatment option in Japanese patients treated with EESs in elective PCI.

Beamline AR-NW12A: high-throughput beamline for macromolecular crystallography at the Photon Factory

AR-NW12A is an in-vacuum undulator beamline optimized for high-throughput macromolecular crystallography experiments as one of the five macromolecular crystallography (MX) beamlines at the Photon Factory. This report provides details of the beamline design, covering its optical specifications, hardware set-up, control software, and the latest developments for MX experiments. The experimental environment presents state-of-the-art instrumentation for high-throughput projects with a high-precision goniometer with an adaptable goniometer head, and a UV-light sample visualization system. Combined with an efficient automounting robot modified from the SSRL SAM system, a remote control system enables fully automated and remote-access X-ray diffraction experiments.

Simulation Study on Geometric and Electronic Structure of Photovoltaic Molecules

We investigate the geometric and electronic structure of porphyrin-fullerene based supramolecular system in which have an extremely long-lived charge-separated state have been achieved, using first principle calculations. The results suggest that the LUMO state of this supramolecule is localized on the fullerene and HOMO state is localized on the porphyrin moiety.

X-ray phase imaging of biological soft tissue using a direct-sensing x-ray HARP tube camera

A HDTV camera having a direct-sensing x-ray high-gain avalanche rushing amorphous photoconductor (HARP) tube was used, for the first time, to acquire x-ray phase maps. The tube can achieve a high sensitivity as a result of the avalanche multiplication process in the HARP target. A beryllium plate, rather than a glass plate, was used as the face plate of the tube to minimize the loss of x-rays due to absorption, and a 15 microm thick HARP target was directly formed on it. In the experiment, the x-ray phase shifts produced by a rat liver were measured using synchrotron x-rays (lambda = 0.0766 nm) and a triple Laue-case (LLL) x-ray interferometer. Interference patterns produced by the sample were observed with the direct-sensing x-ray HARP tube camera. A voltage of 1300 V was applied to the HARP target to give an output signal gain of two. The camera was operated in 1125 scanning-line mode, and real-time images were stored on a workstation at a rate of 30 images/s with an image format of 960 (H) x 1100 (V) pixels. A phase-map image of the sample was successfully obtained using the fringe scanning method and phase unwrapping. The observed phase shifts ranged from 50 degrees to 200 degrees . Trees of blood vessels in the rat liver were clearly depicted without using a contrast agent. The spatial resolution of the x-ray camera was estimated to be better than 35 microm in the vertical direction and 100 microm in the horizontal direction.

Sphingosine kinase 2 is a nuclear protein and inhibits DNA synthesis

Sphingosine kinase-1 (SPHK1) is a key enzyme catalyzing the formation of an important bioactive lipid messenger, sphingosine 1-phosphate, and is implicated in the regulation of cell proliferation and antiapoptotic processes. Biological features of another isozyme SPHK2, however, remain unclear. The present studies were undertaken to characterize SPHK2 by comparison with SPHK1. When SPHK2 was transiently expressed in various cell lines, it was localized in the nuclei as well as in the cytosol, whereas SPHK1 was distributed in the cytosol but not in the nucleus. We have mapped a functional nuclear localization signal (NLS) to the N-terminal region of SPHK2. We have observed that the expression of SPHK2 in various cell types causes inhibition of DNA synthesis, resulting in the cell cycle arrest at G1/S phase. We have also demonstrated that an NLS mutant of SPHK2, SPHK2R93E/R94E, failed to enter the nucleus and to inhibit DNA synthesis. Moreover, a fusion protein, NLS-SPHK1, where SPHK1 was fused to the NLS sequence of SPHK2 acquired the ability to enter nuclei and inhibited DNA synthesis. These results indicate that SPHK2 localizes in the nuclei and causes inhibition of DNA synthesis, and this may affect subsequent cellular events.

Clinical pilot studies on pre-operative hyperthermic tumour ablation for advanced breast carcinoma using an 8 MHz radiofrequency heating device

The multimodality treatment approach for advanced breast cancer provides survival advantages with decreased locoregional and distant recurrences, but these intensive anti-tumour treatments cause severe myelosuppression. Thus, in this study, the usefulness of pre-operative anti-tumour treatment without myelosuppression was investigated. Nine patients with advanced breast carcinoma underwent pre-operative hyperthermic tumour ablation (HTA) using an 8 MHz radiofrequency (RF) heating device (Thermotron RF-8) combined with a grounded needle electrode. The patients had a mean age of 58.3+/-13.9 years and included four patients with stage IIIA, two with stage IIIB and three with stage IV cancer. The target temperature was over 50 degrees C. They tolerated pre-operative HTA therapy well with no early or late complications. The initial mean tumour size was 122.1+/-71.5 cm3 and the post-HTA tumour size was 82.2+/-63.4 cm3; the reduction rate was significant (p = 0.000 293). After the pre-operative HTA, all patients underwent surgery with Level III nodal extirpation. Post-operatively, no locoregional recurrence was observed. Microscopic examination of the primary focus showed complete coagulation necrosis expanding for a diameter of 3.5-5.0 cm. Taken together, the pre-operative HTA was a safe, well-tolerated and effective treatment, achieving tumour reduction as well as complete coagulation necrosis that resulted in a large volume of destruction in breast cancer tissue.

Identification and characterization of RPK118, a novel sphingosine kinase-1-binding protein

Sphingosine kinase (SPHK) is a key enzyme catalyzing the formation of sphingosine 1 phosphate (SPP), a lipid messenger that is implicated in the regulation of a wide variety of important cellular events through intracellular as well as extracellular mechanisms. However, the molecular mechanism of the intracellular actions of SPP remains unclear. Here we have cloned a novel sphingosine kinase-1 (SPHK1)-binding protein, RPK118, by yeast two-hybrid screening. RPK118 contains several functional domains whose sequences are homologous to other known proteins including the phox homology domain and pseudokinase 1 and 2 domains and is shown to be a member of an evolutionarily highly conserved gene family. The pseudokinase 2 domain of RPK118 is responsible for SPHK1 binding as judged by yeast two-hybrid screening and immunoprecipitation studies. RPK118 is also shown to co-localize with SPHK1 on early endosomes in COS7 cells expressing both recombinant proteins. Furthermore, RPK118 specifically binds to phosphatidylinositol 3-phosphate. These results strongly suggest that RPK118 is a novel SPHK1-binding protein that may be involved in transmitting SPP-mediated signaling into the cell.

Systematic analysis of supersaturation and lysozyme crystal quality

A systematic study of the correlation between supersaturation and protein crystal quality was carried out employing atomic force microscopy (AFM) and X-ray crystallography with synchrotron radiation (SR). The surface morphology and growth rates of hen egg-white (HEW) lysozyme crystals soaked in various supersaturated solutions were first investigated by AFM. The results showed that the formation of two-dimensional islands increased as a function of supersaturation. The growth rate (molecule intake speed) also increased as a function of supersaturation. In order to examine the correlation between the surface morphology, growth rate and the crystal quality, X-ray diffraction experiments were performed. It was confirmed that crystals grown at lower supersaturations diffracted better with higher signal-to-noise ratios, including better agreement between symmetry-related reflections. The results strongly suggested that the molecular misorientation at high supersaturation affected the crystal quality.

Regulation of mammalian phospholipase D2: interaction with and stimulation by G(M2) activator

We have previously reported that a heat-stable activator for ganglioside metabolism, G(M2) activator, potently stimulates ADP-ribosylation factor (ARF)-dependent phospholipase D (PLD) activity (presumably PLD1) in an in vitro system [Nakamura, Akisue, Jinnai, Hitomi, Sarkar, Miwa, Okada, Yoshida, Kuroda, Kikkawa and Nishizuka (1998) Proc. Natl. Acad. Sci. U.S.A. 95, 12249-12253]. However, little is known about the regulation of PLD2. In the present studies we have investigated the regulation of PLD2 by G(M2) activator and various other regulators including ARF. PLD2 was potently stimulated in vitro by G(M2) activator in a time- and dose-dependent manner. Neither ARF nor protein kinase C caused any significant changes in PLD2 activity. Importantly, PLD2 responsiveness to ARF was greatly enhanced by G(M2) activator, suggesting a possible role for G(M2) activator as a coupling factor. G(M2) activator was also demonstrated to physically associate with PLD2 in a stoichiometric manner. Further, PMA stimulation of COS-7 cells overexpressing both G(M2) activator and PLD2 resulted in a marked increase in the association of the two molecules. Interestingly, ARF association with PLD2 was greatly increased by G(M2) activator. Moreover, G(M2) activator enhanced PMA-induced PLD activity in a synergistic manner with ARF in streptolysin-O-permeabilized, cytosol-depleted HL-60 cells, suggesting that G(M2) activator may regulate PLD in a concerted manner with other factors, including ARF, inside the cells.

Differential cellular targets of Epstein-Barr virus (EBV) infection between acute EBV-associated hemophagocytic lymphohistiocytosis and chronic active EBV infection

Unusual Epstein-Barr virus (EBV) infection into T or natural killer cells plays a pivotal role in the pathogenesis of acute EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH) and chronic active EBV infection (CAEBV). The precise frequency and localization of EBV genome in lymphocyte subpopulations especially within T-cell subpopulations are unclear in these EBV-related disorders. This study analyzed the frequency of EBV-infected cells in circulating lymphocyte subpopulations from 4 patients with acute EBV-HLH and 4 with CAEBV. EBV- encoded small RNA-1 in situ hybridization examination of peripheral blood lymphocytes showed a significantly higher frequency of EBV-infected cells of 1.0% to 13.4% in EBV-HLH and 1.6% to 25.6% in CAEBV, respectively. The patterns of EBV infection in lymphocyte subpopulations were quite different between acute EBV-HLH and CAEBV. EBV infection was predominant in CD8(+) T cells in all EBV-HLH patients, whereas the dominant EBV-infected cell populations were non-CD8(+) lymphocyte subpopulations in CAEBV patients. Phenotypical analysis revealed that EBV-infected cell populations from both EBV-HLH and CAEBV were activated. There was no predominance of any EBV substrain of latent membrane protein-1, EBV-associated nuclear antigen (EBNA)-1, and EBNA-2 genes between the 2 abnormal EBV-associated disorders, and self-limited acute infectious mononucleosis. These results showing differential virus-cell interactions between acute EBV-HLH and CAEBV indicated different pathogenic mechanisms against EBV infection between the 2 EBV-associated diseases, which accounts for the difference in clinical manifestations between the 2 diseases.

Crystallization and preliminary X-ray analysis of catalase-peroxidase from the halophilic archaeon Haloarcula marismortui

Catalase-peroxidases are bifunctional enzymes found in many microorganisms. Crystals of catalase-peroxidase from the halophilic archaeon Haloarcula marismortui were obtained using the hanging-drop vapour-diffusion method. The rhombic plate-shaped crystals were grown from purified protein solution using (NH(4))(2)SO(4) as precipitant at 293 K. The crystal belongs to the monoclinic system, space group C2, and diffracted beyond 2.0 A resolution.

Follicle-stimulating hormone promotes the growth of human epithelial ovarian cancer cells through the protein kinase C-mediated system

We have previously described that follicle-stimulating hormone (FSH) stimulated the growth of human epithelial ovarian cancer tissues and cells. In order to determine the signaling pathway on FSH action in ovarian cancer, we used an epithelial ovarian cancer cell line (HRA line) which constitutively FSH receptors (FSHRs). FSH significantly increased cell proliferation (230.1 +/- 20.5%, P < 0.05) and (3)H-thymidine uptake (443.5 +/- 35.1%, P < 0.01). 1-(5-Isoquinolinesulfonyl)-2-methyipiperazine (H7, 1 5 nM), staurosponine (STR, 5 nM) and calphostin C (5 nM), specific protein kinase C (PKC) inhibitors, significantly suppressed the FSH-stimulated cell growth (120.2-140.2%, P < 0.05) and (3)H-thymidine uptake (140.5-173.9%, P < 0.05), whereas N-(2-guanidinoethyl)-5-isoquinoline-sulfon-amide (HA1004, l5 nM), which is a derivant of H7 and inhibits most of protein kinases except PKC, showed no effect on the FSH-stimulated cell growth and (3)H-thymidine uptake. A pretreatment with 12-0-tetradecanoylphorbol-13 acetate (TPA, 100 ng/ml) or STR (20 nM) significantly suppressed the subsequent FSH-stimulated cell growth (TPA; 152.3 +/-10.3%, STR; 160.4 +/- 15.9%, P < 0.05) and (3)H-thymidine uptake (TPA; 250.4 +/-18.3%, STR; 208.7 +/- 15.9%, P < 0.05). STR abolished the suppression of TPA preincubation on the subsequent FSH-stimulated cell growth and (3)H-thymidine uptake. HRA cells constitutively expressed PKCalpha but not PKCbeta nor PKCgamma. The levels of either expression of PKCalpha protein and mRNA were significantly amplified by FSH. These data suggest that stimulation of PKCalpha transcription is involved in the FSH-stimulated cell growth and DNA synthesis in epithelial ovarian cancer cells.

Horizontal transfer of the photosynthesis gene cluster and operon rearrangement in purple bacteria

A 37-kb photosynthesis gene cluster was sequenced in a photosynthetic bacterium belonging to the beta subclass of purple bacteria (Proteobacteria), Rubrivivax gelatinosus. The cluster contained 12 bacteriochlorophyll biosynthesis genes (bch), 7 carotenoid biosynthesis genes (crt), structural genes for photosynthetic apparatuses (puf and puh), and some other related genes. The gene arrangement was markedly different from those of other purple photosynthetic bacteria, while two superoperonal structures, crtEF-bchCXYZ-puf and bchFNBHLM-lhaA-puhA, were conserved. Molecular phylogenetic analyses of these photosynthesis genes showed that the photosynthesis gene cluster of Rvi. gelatinosus was originated from those of the species belonging to the alpha subclass of purple bacteria. It was concluded that a horizontal transfer of the photosynthesis gene cluster from an ancestral species belonging to the alpha subclass to that of the beta subclass of purple bacteria had occurred and was followed by rearrangements of the operons in this cluster.

Laparoscopic wedge resection of gastric submucosal tumors

Minimally invasive surgery has revolutionized the treatment of gastrointestinal tumors. Submucosal tumors (SMTs) of the stomach can be resected using laparoscopic techniques. Between 1993 and 1997, laparoscopic wedge resection was performed in 34 patients with an SMT of the stomach. The tumors ranged from 8 to 60 mm in diameter. All surgical margins were clear. The average operative time was 131 minutes. Most of the patients began eating on the first postoperative day and were discharged within 5 to 7 days. Histopathologic examination of the tumors showed gastrointestinal stromal tumor (n = 14), ectopic pancreas (n = 7), leiomyosarcoma (n = 4), schwannoma (n = 3), carcinoid (n = 2), leiomyoma (n = 2), an inflammatory lesion caused by parasites (n = 1), and cyst (n = 1). No recurrences were observed over the 5-year follow-up period. A solid SMT of the stomach larger than 20 mm in diameter can be treated using laparoscopic wedge resection.

Enhancement in the perfection of orthorhombic lysozyme crystals grown in a high magnetic field (10 T)

Orthorhombic crystals of hen egg-white (HEW) lysozyme were grown in a homogeneous and static magnetic field of 10 T. All crystals grown at 10 T were oriented such that their crystallographic c axes were parallel to the magnetic field direction and showed a narrower average full-width at half-maximum (FWHM) of the rocking curve than those grown at 0 T. Rocking-width measurements were made at the BL-10A station at the Photon Factory, Tsukuba, Japan, using a high-resolution vertical-type four-circle diffractometer. Crystal perfection was evaluated using the FWHM of the rocking curve; the effects of the magnetic field on the quality of the crystals were examined by comparison of the FWHM of seven crystals grown at 10 and 0 T. The FWHMs of the reflections along the a, b and c axes decreased by 23.5, 35.3 and 27.8%, respectively, and those of other general reflections decreased by 17.4-42.2% in the crystals grown at high magnetic field. These results clearly showed that a magnetic field of 10 T improved the crystal perfection of the orthorhombic lysozyme crystals. As a result, the maximum resolution of X-ray diffraction increased from 1.3 A at 0 T to 1.13 A at 10 T. The magnetic field also affected the dimensions of the unit cell, increments being 0.2% for the a and c axes and 0.1% for the b axis, respectively. These facts suggest that the application of a high magnetic field during crystallization might result in remarkable enhancements in the diffraction power of protein crystals having magnetic anisotropy.

Head movements and neck muscle activities associated with the jaw movement during mastication in the rabbit authors

Rhythmical head movements and neck muscle activities associated with the masticatory jaw movement were investigated in rabbits. In natural mastication, head movements and neck muscle activities showed a rhythmical feature synchronized with jaw movement. During cortically induced rhythmical jaw movements, some neck muscle showed rhythmical activity induced by biting a wooden stick. Neck muscles may contribute to the rhythmical head movement after loading the tooth with food.

Matrix metalloproteinase expression in cultured human gastric wall fibroblasts--interactions with Helicobacter pylori isolated from patients with ulcers

BACKGROUND

Matrix metalloproteinases (MMPs), enzymes capable of degrading collagens and other extracellular matrix components, have been implicated in gastric ulcer formation. However, the effect on MMP expression of Helicobacter pylori, also implicated in these lesions, has not been studied to our knowledge.

AIM

To seek links between H. pylori and MMP expression likely to affect gastric ulcer formation. After fibroblasts from human gastric wall were cocultured with H. pylori. concentrations of MMP-1 and -2 in the medium were determined by enzyme-linked immunosorbent assays.

RESULTS

Whereas MMP-1 was not detected in media from fibroblasts or H. pylori culture alone, MMP-1 was detected in cocultures (P<0.01). Similar amounts of MMP-2 were detected in medium from fibroblasts cultured alone and with H. pylori. No MMP-2 production by H. pylori cultured alone was detected.

CONCLUSIONS

MMP-1 appears to be important in gastric ulcer pathogenesis, and MMP-1 induction by H. pylori may impede gastric ulcer healing.

Activation of matrix metalloproteinase-2 in head and neck squamous cell carcinoma: studies of clinical samples and in vitro cell lines co-cultured with fibroblasts

We undertook this present study to investigate the activation of matrix metalloproteinase-2 (MMP-2) in human head and neck squamous cell carcinomas (HNSCC) tissues and cell lines. Gelatinolytic activities of active MMP-2 were significantly higher in carcinoma samples than in normal portions. Furthermore, the activation ratio of proMMP-2 significantly correlated with cervical lymph node metastasis. In vitro studies revealed an HNSCC cell line, HEp-2, to produce neither the pro form nor the active form of MMP-2, but human fibroblasts were found to produce proMMP-2. However, coculture of HEp-2 cells with fibroblasts resulted in the production of not only proMMP-2 but also activeMMP-2 in the culture medium. Northern blot analysis revealed a stronger expression of membrane-type 1 matrix metalloproteinase (MT1-MMP),which is a specific activator of MMP-2, mRNA in HEp-2 cells than in fibroblasts. These results suggest the activation of proMMP-2 as an important event in the process of HNSCC metastasis. They also suggest MMP-2 is secreted in its pro form by stromal fibroblasts surrounding the cancer cells and activated by MT1-MMP localized on the cancer cells.

Laparoscopic wedge resection of gastric submucosal tumors

Minimally invasive surgery has revolutionized the treatment of gastrointestinal tumors. Submucosal tumors (SMTs) of the stomach can be resected using laparoscopic techniques. Between 1993 and 1997, laparoscopic wedge resection was performed in 34 patients with an SMT of the stomach. The tumors ranged from 8 to 60 mm in diameter. All surgical margins were clear. The average operative time was 131 minutes. Most of the patients began eating on the first postoperative day and were discharged within 5 to 7 days. Histopathologic examination of the tumors showed gastrointestinal stromal tumor (n = 14), ectopic pancreas (n = 7), leiomyosarcoma (n = 4), schwannoma (n = 3), carcinoid (n = 2), leiomyoma (n = 2), an inflammatory lesion caused by parasites (n = 1), and cyst (n = 1). No recurrences were observed over the 5-year follow-up period. A solid SMT of the stomach larger than 20 mm in diameter can be treated using laparoscopic wedge resection.