Coronary artery spasm in the genesis of myocardial ischemia

Angina pectoris that is mainly caused by coronary artery spasm (coronary spastic angina) has 1 or more of the following characteristics: (1) the attack occurs at rest, (2) the attack is associated with ST-segment elevation on the electrocardiogram (not necessarily so in case of old myocardial infarction), (3) the attack has a variable exercise threshold, and (4) the attack is suppressed by calcium antagonists but not by beta-adrenergic blocking agents. By this criteria, coronary artery spasm is involved in the development of most angina pectoris in patients with 1-vessel disease. The role of coronary artery spasm in the development of acute myocardial infarction is still controversial. However, in this study, injection of nitroglycerin, 0.2 mg, into the totally or subtotally occluded coronary artery either released the occlusion or improved the patency in 13 of the 69 patients (18.8%) with acute transmural myocardial infarction in whom coronary arteriography was performed within 4.0 +/- 1.9 hours of the onset of symptoms. Thus, coronary artery spasm appears to play a role in the production of acute myocardial infarction in these patients.     

beta-lapachone,a novel plant product,overcomes drug resistance in human multiple myeloma cells

OBJECTIVE: To evaluate the anti-tumor potential of beta-lapachone in multiple myeloma (MM) cell lines (U266, RPMI8226, and MM.1S); MM cell lines resistant to dexamethasone (MM.1R), melphalan (RPMI8226/LR5), doxorubicin (RPMI8226/DOX40), and mitoxantrone (RPMI8226/ MR20); and MM cells from patients (MM1-MM4). MATERIALS AND METHODS: Cytotoxicity of beta-lapachone was assessed by MTT and [3H]-thymidine uptake assays. Apoptosis was analyzed using propidium iodide staining, DNA fragmentation, TUNEL assay, caspase-9 colorimetric assay, and immunoblotting for caspase-3, poly (ADP-ribose) polymerase (PARP), and caspase-8 cleavage products. Paracrine growth of MM cells was assessed by [3H]-thymidine uptake in cultures of bone marrow stromal cells (BMSCs) and MM cells. Interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) secretion in the culture supernatants was measured by specific enzyme-linked immunosorbent assays (ELISAs). RESULTS: beta-lapachone showed significant cytotoxicity in MM cells (IC(50): 4-8 microM). In contrast, normal peripheral blood mononuclear cells (PBMCs) and BMSCs from MM patients were relatively resistant (IC(50): 8-16 microM). IL-6 did not protect against beta-lapachone-induced apoptosis in MM.1S cells, and dexamethasone showed additive cytotoxicity. beta-lapachone also decreased binding of MM.1S cells to BMSCs; abrogated IL-6 and VEGF secretion triggered by adhesion of BMSCs to MM.1S cells; reduced proliferation of MM.1S cells adherent to BMSCs; and decreased intracellular adhesion molecule-1 (ICAM-1) expression on MM.1S cells. Furthermore, beta-lapachone induced typical PARP cleavage, increased caspase-9 proteolytic activity, and activation of caspase-3, without activation of caspase-8 in U266 cells. CONCLUSION: These studies provide a framework for clinical evaluation of beta-lapachone to improve the outcome for patients with MM.     

Attenuated Apoptosis in H. pylori-Colonized Gastric Mucosa of Mongolian Gerbils in Comparison with Mice

Although gastric cancer formation with H. pylori in Mongolian gerbils was recently reported, the same inoculation procedure did not result in cancer formation in other animals such as mice. Disturbed regulation of apoptosis and cell proliferation are known to link the multistep process of carcinogenesis. The present study is designed to examine the level of gastric epithelial cell apoptosis in Mongolian gerbils colonized with the H. pylori (Sydney strain: SS1) in comparison with that in mice. Mice (C57BL/6) and Mongolian gerbils were orally inoculated with SS1 and the stomachs were examined 9 and 18 months later. MPO activity increased persistently in gerbils, but increased transiently in mice. While the levels of DNA fragmentation, caspase-3 activity, and the number of TUNEL-positive cells increased significantly in mice, such parameters were attenuated in gerbils. On the other hand, the number of PCNA-positive cells increased after SS1 inoculation only in Mongolian gerbils, suggesting the enhancement of cell turnover in H. pylori-colonized gerbils. In conclusion, the SS1-induced increase in gastric mucosal apoptosis observed in mice was attenuated significantly in Mongolian gerbils, suggesting the causative role for the higher incidence of gastric carcinogenesis in this animal.     

Cardiac glands hyperplastic polyp of the stomach

Reported herein is a very rare polyp in the gastric cardia of a 49-year-old man. He was referred because of a polyp detected by upper gastrointestinal examination in an affiliated hospital. Endoscopic examination revealed a polyp-like submucosal tumor. Endoscopic ultrasonography revealed minute cystic dilatations and thickening of the submucosal layer. Accordingly, a preliminary diagnosis of cardiac gland hyperplasia was made. The lesion was removed successfully by snare polypectomy. Observed macroscopically, the polyp was 30 mm in diameter and covered with normal gastric mucosa. Examined histologically, the polyp comprised a hyperplastic submucosal cardiac gland.     

Nodular gastritis in adults is caused by Helicobacter pylori infection

A close relationship exists between nodular gastritis and Helicobacter pylori infection in children. The pathogenesis and optimal management of nodular gastritis in adults, however, are unclear. This study describes the clinicopathologic features of nodular gastritis in adults and correlates treatment with outcome. Of 97,262 adult patients who underwent endoscopy, 187 (0.19%) were diagnosed with nodular gastritis, 151 (81%) of whom had dyspepsia. Nodular gastritis predominantly affects young women (49 men and 138 women, mean age, 32.6 years). All 134 patients tested for Helicobacter pylori infection were infected, and 65/66 (98%) had inflammation of both the antrum and the corpus. Twenty-five (13%) had associated lesions (peptic ulcers or cancer). Dyspepsia improved after eradication of Helicobacter pylori infection, but did not improve spontaneously. Nodular gastritis in adults is caused by Helicobacter pylori infection and shows a predilection for females and young adults. Helicobacter pylori eradication decreases symptoms and reduces the risk of peptic ulcers and possibly gastric cancer.     

Involvement of Krüppel-like factor 6 (KLF6) mutation in the development of nonpolypoid colorectal carcinoma

AIM: To examine Krüppel-like factor 6 (KLF6) mutations in nonpolypoid-type tumors and alterations of K-ras, p53,and B-raf in relation between mutation and morphologic type, particularly nonpolypoid-type colorectal carcinomas.METHODS: Fifty-five early nonpolypoid colorectal carcinomas were analyzed. Loss of heterozygosity (LOH) of KLF6 and p53 was determined by microsatellite assay.Mutations of KLF6, K-ras, and B-raf were examined by polymerase chain reaction-single-strand conformation polymorphism followed by direct sequencing. In LOH-positive and/or mutation-positive tumors, multiple (4-7) samples in each tumor were microdissected and examined for genetic alterations, p53 expression was evaluated by immunohistochemistry.RESULTS: LOH of KLF6 and p53 was found in 14 of 29 (48.3%) and 14 of 31 (45.2%) tumors, respectively. In 10 of the 14 (71.4%) KLF6 LOH-positive tumors and 9 of the 14 (64.3%) p53 LOH-positive tumors, LOH was found in all of the microdissected samples. In 1 of the 10 (10.0%) KLF6 LOH-positive tumors, a single missense mutation was identified. K-ras and B-raf mutations were found in 5 of 55 (9.1%) and 6 of 55 (10.9%) tumors,respectively. However, these mutations were detected only in subsets of microdissected tumor samples.CONCLUSION: These data suggest that KLF6 and p53 mutations are involved in the development of nonpolypoid colorectal carcinoma, whereas K-ras and B-raf mutations are not.     

The upper turnover site in the reentry circuit of common atrial flutter

The upper turnover site of the reentry circuit of common AF is anterior to the orifice of the superior vena cava. The reentrant excitation wavefront seems to circulate along the entire tricuspid annulus around anatomic (i.e., orifices of superior and inferior vena cava) and functional obstacles between the orifices as proposed previously.¹⁸     

Frequent detection and characterization of hepatitis E virus variants in wild rats (Rattus rattus) in Indonesia

One hundred sixteen rats (Rattus rattus) captured in Indonesia from 2011 to 2012 were investigated for the prevalence of hepatitis E virus (HEV)-specific antibodies and HEV RNA. Using an ELISA based on HEV genotype 4 with an ad hoc cutoff value of 0.500, 18.1 % of the rats tested positive for anti-HEV IgG. By nested RT-PCR, 14.7 % of the rats had rat HEV RNA, and none were positive for HEV genotype 1-4. A high HEV prevalence among rats was associated with lower sanitary conditions in areas with a high population density. Sixteen of the 17 HEV isolates obtained from infected rats showed >93.0 % nucleotide sequence identity within the 840-nucleotide ORF1-ORF2 sequence and were most closely related to a Vietnamese strain (85.9-87.9 % identity), while the remaining isolate differed from known rat HEV strains by 18.8-23.3 % and may belong to a novel lineage of rat HEV. These results suggest a wide distribution of rat HEV with divergent genomes.     

A collision tumor of solitary fibrous tumor/hemangiopericytoma and meningioma: A case report with literature review

An intracranial collision tumor is a rare lesion composed of two histologically different neoplasms in the same anatomic location. Even more rare is the collision tumor of a solitary fibrous tumor/hemangiopericytoma (SFT/HPC) and meningioma. The patient was a 46-year-old woman who had a 40 × 35 × 30-mm mass in the vermis of the cerebellum. Histologically, the mass consisted of two different components. One component showed the morphology of meningioma (World Health Organization (WHO) grade I), and the other component exhibited small round cell proliferation with hypercellular density, which was revealed to be SFT/HPC (WHO grade III) based on STAT6 immunohistochemistry. STAT6 showed completely different immunohistochemistry results in these two components (nuclear-negative in meningioma and nuclear-positive in SFT/HPC). Since these two neoplasms are associated with different prognoses, they should be distinguished from each other. When meningioma and an SFT/HPC-like lesion are identified morphologically, it is important to recognize the presence of such a collision tumor composed of meningioma and SFT/HPC, and identify the SFT/HPC component by employing STAT6 immunohistochemistry.