[Two Cases of Portal Vein Stent Placement for Portal Vein Stenosis Due to Recurrence of Pancreatic Cancer].

We report 2 cases of portal vein stent placement for malignant portal stenosis due to recurrence of pancreatic cancer with symptoms of portal hypertension. Case 1: The patient was a 68-year-old female. Five years ago, a mass was found around the aorta on a computerized tomography(CT)scan taken after a residual pancreatectomy for pancreatic cancer. It was diagnosed as lymph node recurrence and S-1 therapy was started. As further tumor enlargement led to portal vein compression, venostasis around the ascending jejunum, anemia, and black stools, a portal vein stent was placed. The portal vein blood flow was improved, the collateral vessels disappeared, and the patient no longer experienced anemia or black stool. Case 2: A 75-year-old female patient underwent a subtotal gastric-sparing pancreaticoduodenectomy and combined resection of the portal vein for pancreas head cancer. On a postoperative CT scan taken 6 months later, a mass compressing the portal vein appeared, which was diagnosed as a local recurrence. As thrombocytopenia was observed, a portal vein stent was placed before starting chemotherapy. The portal vein blood flow and the platelet count improved. Portal vein stenting is an effective procedure for malignant portal stenosis, improving portal blood flow and clinical symptoms.

Distribution of cervical intraepithelial neoplasia is closely associated with HPV status and uterine position.

Although cervical intraepithelial neoplasia (CIN) lesions are considered to be not randomly distributed across the cervix, but predominantly in the anterior wall, the clinicopathological etiology remains unknown. Herein, we aimed to elucidate the relationship between quantitatively measured area of CIN2/3 and cervical cancer associated factors by retrospective cohort study. We analyzed 235 consecutive therapeutic conization specimens dissected as a single intact section to determine CIN2/3 area and its correlation with both clinical risk factors including human papillomavirus (HPV) status (single or multiple infection) and uterine position defined by transvaginal ultrasound. Cervical wall was classified into three groups: anterior: (11, 12, 1, and 2 o'clock), posterior (5, 6, 7, and 8 o'clock) and lateral (3, 4, 9, and 10 o'clock). Multiple regression revealed that younger age and HPV16 status were significantly correlated with CIN2/3 area (p = 0.0224 and p = 0.0075, respectively). The Jonckheere-Terpstra test showed a significant trend: CIN2/3 area was highest in the single HPV16 group, followed by the multiple HPV16 group and the non-HPV16 group (p < 0.0001). CIN2/3 area in the anterior wall was statistically significantly larger than the posterior and lateral wall (p = 0.0059 and p = 0.0107, respectively). CIN2/3 area in the anterior wall was significantly greater with anteversion-anteflexion than retroversion-retroflexion (p = 0.0485), whereas CIN2/3 area in the posterior wall was significantly larger with retroversion-retroflexion than anteversion-anteflexion (p = 0.0394). In conclusion, the topographical distribution of CIN2/3 area is closely associated with patient age, high-risk HPV status, especially single HPV16 infection and uterine position.

Comparison of complete resection rates in cold snare polypectomy using two different wire diameter snares: A randomized controlled study.

BACKGROUND AND AIM: Cold snare polypectomy (CSP) is a standard treatment for small colorectal polyps. This study examined the effect of different snare wire diameters on complete histological resection rate, resection depth, and CSP safety. METHODS: This randomized controlled trial was conducted at two institutions between June 2019 and March 2021. Eligible colorectal polyps (≤10 mm) were randomly assigned in a 1:1 ratio to receive either CSP with a conventional snare made of normal-diameter wire (0.40 mm) or CSP with a dedicated snare made of thin wire (0.23 mm). The primary endpoint was the complete resection rate determined on histological assessment of the resected specimen. RESULTS: In total, 254 lesions in 152 patients were included, with 128 and 126 lesions assigned to the normal-diameter wire snare group and the thin-wire snare group, respectively. No significant differences were observed in patient characteristics between the two groups. The histological complete resection rate was significantly higher in the thin-wire snare group than in the normal-diameter wire snare group (70.0% vs 81.0%, P = 0.04). The normal-diameter wire snare group had significantly more cases of unclear horizontal margin evaluation than the thin-wire snare group (28.1% vs 15.9%, P = 0.02). No significant differences were observed between the two groups in the muscularis mucosa and submucosa of the resected specimens or the thickness of the submucosa in the resected specimens. CONCLUSIONS: CSP with a dedicated thin-wire snare provides more specimens that can be evaluated at the horizontal end and increases the histological complete resection rate.

Width and depth of resection for small colorectal polyps: hot versus cold snare polypectomy.

BACKGROUND AND AIMS: Curability is associated with resection width and depth in polypectomy. We evaluated the resection width and depth achieved with hot snare polypectomy (HSP) and cold snare polypectomy (CSP) for small colorectal polyps. METHODS: In this single-center, prospective, randomized controlled study, patients with rectal or rectosigmoid polyps ≤10 mm in diameter were treated with HSP or CSP. Resection width was evaluated as mucosal defect size, measured immediately postprocedure and 1 day later. Resection depth was histologically evaluated using obtained specimens. RESULTS: Fifty-two patients were enrolled. Mean lesion size was 5.6 mm with HSP (n = 27) and 5.8 mm with CSP (n = 25). Mean mucosal defect diameter immediately after HSP and CSP was 5.1 mm and 7.5 mm, respectively (P < .001). The diameter 1 day after the procedure increased by 29% (95% confidence interval [CI], 17%-41%) with HSP and decreased by 25% (95% CI, 18%-32%) with CSP (P < .001). Muscularis mucosa was obtained similarly with HSP and CSP (96% [95% CI, 82%-99%] vs 92% [95% CI, 75%-98%]; P = .603). Submucosal tissue was obtained significantly more frequently with HSP than with CSP (81% [95% CI, 63%-92%] vs 24% [95% CI, 11%-43%]; P < .001). CONCLUSIONS: The resection width immediately after CSP was larger than that after HSP but was significantly smaller at day 1 after resection. Although the resection depth after CSP was more superficial, muscularis mucosa was obtained in most specimens. Thus, CSP has sufficient resection width and depth to enable complete polyp resection and potentially has a superior safety profile than HSP.

[A Case of Giant Prostate Carcinoma Effectively Treated with External-Beam Radiation Therapy].

We present a case of gigantic prostate tumor in a patient with castration-resistant prostate cancer with successful local control by external-beam radiation therapy. A 71-year-old man was shown to have a prostate specific antigen (PSA)level of 24.5 ng/ml, Gleason 9, cT2N1M1a, prostate adenocarcinoma with an estimated prostate volume of 26.9 g. He achieved a PSA nadir at 4 months after the initial androgen deprivation therapy and was diagnosed with castration-resistant prostate cancer three years later. Eight months after the diagnosis of castration-resistant prostate cancer, he visited our hospital due to urinary retention. Abdominal computed tomography scan showed a gigantic prostatic mass occupying the whole pelvic cavity along with multiple lymph node, bone and liver metastases. The estimated volume of the prostate was 878 g. A tumor needle biopsy revealed a histological finding similar to the initial prostate biopsy which was adenocarcinoma with Gleason 9. He underwent external beam radiation therapy (60 Gy) to the prostate, which brought about excellent local control with a 96.7% shrinkage of tumor at 2 months after radiation therapy. He had no complaints of urinary symptoms and no need for urethral catheterization until he died of prostate cancer metastases.

Cloning and characterization of a gene coding for a major extracellular chitosanase from the koji mold Aspergillus oryzae.

A gene coding for a major extracellular chitosanase was isolated from Aspergillus oryzae IAM2660. It had a multi-domain structure composed of a signal peptide, a catalytic domain, Thr- and Pro-rich linkers, and repeated peptides (the R3 domain) from the N-terminus. The R3 domain bound to insoluble powder chitosan, but it did not promote the hydrolysis rate of the chitosanase to any extent.

Perinatal Management in a Pregnant Woman with Ureteropelvic Junction Obstruction: Case Report and Literature Review.

Although giant hydronephrosis (GH) associated with ureteropelvic junction obstruction (UPJO) is extremely rarely detected in pregnant women, diagnostic methods, therapeutic approaches, and perinatal management have not been established. A 31-year-old Japanese primipara had a 15 cm × 12 cm multi-cystic mass in the right abdomen detected by transabdominal ultrasound at gestational week 26. Magnetic resonance imaging revealed that the mass was right renal GH. She underwent serial ultrasound-guided transretroperitoneal drainage as conservative treatment. She delivered vaginally at gestational week 36. Since she had flank pain and a documented non-functional right kidney, laparoscopic nephrectomy was conducted 22 months after delivery. UPJO with fewer smooth muscle cells and fibrosis was histologically diagnosed in the surgical specimen. Her postpartum and postoperative courses were uneventful for 10 months. We performed a literature review of diagnostic methods, clinical characteristics, and perinatal management in pregnant women with GH due to UPJO.

Weaving hypothesis of cardiomyocyte sarcomeres: discovery of periodic broadening and narrowing of intercalated disk during volume-load change.

To investigate how cardiomyocytes change their length, echocardiographic and morphological studies were performed on rabbit hearts that were subjected to volume overload, overload removal, and repeated cycles of overload and overload removal. These conditions were created by arterio-venous fistula between the carotid artery and jugular vein, closure of the fistula, and cycles of repeatedly forming and closing fistula, respectively. After overload, hearts dilated and myocytes elongated. Intercalated disks repeatedly broadened and narrowed with a 2-day cycle, which continued for 8 weeks in many animals. The cycle consisted of shifts between five modes characterized by two interdigitation elongation-and-shortenings as follows: (I) flat with short ( approximately 1/4 to approximately 1/3 sarcomere long) interdigitations; (II) flat with long (one sarcomere long) interdigitations; (III) grooved with short interdigitations; (IV) grooved with long interdigitations; (V) flat with short interdigitations intermingled by sporadic long interdigitations; and return to (I). After overload removal, hearts contracted and myocytes shortened with similar 2-day broadening and narrowing cycle of intercalated disks, in which the five modes were reversed. Repeated overload and overload removal resulted in the repetition of myocyte elongation and shortening. We hypothesize that a single elongation-and-shortening event creates or disposes one sarcomere layer, and the two consecutive elongation-and-shortenings occur complementarily to each other so that the disks return to their original state after each cycle. Our hypothesis predicts that intercalated disks weave and unravel one sarcomere per myocyte per day.

[In vitro susceptibilities to levofloxacin and various antibacterial agents of 12,919 clinical isolates obtained from 72 centers in 2007].

We have reported in this journal in vitro susceptibilities of clinical isolates to antibiotics every year since 1992. In this paper, we report the results of an analysis of in vitro susceptibilities of 12,919 clinical isolates from 72 centers in Japan to selected antibiotics in 2007 compared with the results from previous years. The common respiratory pathogens, Streptococcus pyogenes, Streptococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenzae maintained a high susceptibility to fluoroquinolones (FQs). The resistance of S. pyogenes to macrolides has been increasing every year and this was especially clear this year. Most strains of Enterobacteriaceae except for Escherichia coli showed a high susceptibility to FQs. Almost 30% of E. coli strains were resistant to FQs and the resistance increased further this year. FQs resistance of methicillin-resistant Staphylococcus aureus (MRSA) was approximately 95% with the exception of 45% for sitafloxacin (STFX). FQs resistance of methicillin-susceptible S. aureus (MSSA) was low at about 10%. FQs resistance of methicillin-resistant coagulase negative Staphylococci (MRCNS) was higher than that of methicillin-susceptible coagulase negative Staphylococci (MSCNS), but it was lower than that of MRSA. However, FQs resistance of MSCNS was higher than that of MSSA. FQs resistance of Enterococcus faecalis was 22.5% to 29.6%, while that of Enterococcusfaecium was more than 85% except for STFX (58.3%). In clinical isolates of Pseudomonas aeruginosa derived from urinary tract infections, FQs resistance was 21-27%, which was higher than that of P. aeruginosa from respiratory tract infections at 13-21%, which was the same trend as in past years. Multidrug resistant strains accounted for 5.6% in the urinary tract and 1.8% in the respiratory tract. Acinetobacter spp. showed high susceptibility to FQs. The carbapenem resistant strains, which present a problem at present, accounted for 2.7%. Neisseria gonorrhoeae showed high resistance of 86-88% to FQs. The results of the present survey indicated that although methicillin-resistant Staphylococci, Enterococci, E. coli, P. aeruginosa, and N. gonorrhoeae showed resistance tendencies, and other species maintained high susceptibility rates more than 90% against FQs, which have been used clinically for over 15 years.

Hepatobiliary cystadenocarcinoma with rapid growth: report of a case.

We describe a case of histologically proven hepatobiliary cystadenocarcinoma with an emphasis on the longterm clinical course. The patient was a 75-year-old man who had been diagnosed as having a simple hepatic cyst at our hospital and had been followed up by abdominal sonography (US) for about 10 years. However, the lesion subsequently showed a sudden increase in size and a marked change in US findings, i.e., from a benign hepatic cyst to a complete solid lesion. Contrast-enhanced US revealed the lesion to be filled with fine vessels. This rapid change led us to strongly suspect a hepatobiliary cystadenocarcinoma and, thus, left lateral segmentectomy was performed. The patient is doing well 6 months after the surgical treatment.

[In-vitro susceptibilites to levofloxacin and various antibacterial agents of 18,639 clinical isolates obtained from 77 centers in 2004].

A total of 18,639 clinical isolates in 19 species collected from 77 centers during 2004 in Japan were tested for their susceptibility to fluoroquinolones (FQs) and other selected antibiotics. The common respiratory pathogens, Streptococcus pyogenes, Streptococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenzae showed a high susceptible rate against FQs. The isolation rate of beta lactamase non-producing ampicillin-resistant H. influenzae was approximately three times as large as those of western countries. Most strains of Enterobacteriaceae were also susceptible to FQs. The resistance rate of Escherichia coli against FQs has however been rapidly increasing so far as we surveyed since 1994. The FQs-resistant rate in methicillin-resistant Staphylococcus aureus (MRSA) showed approximately 90% except for 36%. of sitafloxacin while FQs-resistant rate in methicillin-susceptible S. aureus (MSSA) was around 5%. The FQs-resistant rate of methicillin-resistant coagulase negative Staphylococci (MRCNS) was also higher than that of methicillin-susceptible coagulase negative Staphylococci (MSCNS), however, it was lower than that of MRSA. In Pseudomonas aeruginosa clinical isolates, 32-34% from UTI and 15-19% of from RTI was resistant to FQs. Acinetobacter spp. showed a high susceptibility to FQs. Although FQs-resistant Neisseria gonorrhoeae have not been increased in western countries, it is remarkably high in Japan. In this survey, isolates of approximately 85% was resistant to FQs.

Ultrastructure of endothelial cells under flow alteration.

Endothelial cells are stable and quiet in normal animals. They arrange regularly and have a smooth lumen surface and thin endothelial wall. According to Thoma's principle (1893) and Kamiya and Togawa's principle (1980) on the relationship of the vascular diameter to flow alteration, blood flow is in equilibrium to the diameter and in a physiological state. That is to say, there is no fast flow or slow flow. To understand the nature of the endothelial cells, we should investigate endothelial cells under flow alteration to break the equilibrium state. Endothelial cells under increased flow were studied in arteries with an arteriovenous fistula or in the capillaries of myocardium with volume-overloaded hearts or of the skeletal muscle by electrical stimulation. Those under decreased flow were studied by the closure of the fistula or by ceasing the stimulation. Endothelial cells in the coarctation of the arteries were also observed. Endothelial cells were activated by increased flow in the arteries and capillaries, while they were inactivated by decreased flow. Endothelial activation is characterized as lumen protrusions, increase of cytoplasmic organelles, abluminal protrusions, basement membrane degradation, internal elastic lamina degradation in the arteries, and sproutings in the capillaries. These are ultrastructurally comparable to angiogenesis. Endothelial inactivation is characterized by the decrease of endothelial cell number with apoptosis, which is ultrastructurally comparable to angioregression. We assume that endothelial cells respond to increased flow by angiogenesis and to decreased flow by angioregression.

Side-to-side linking of myocardial cells in hypertrophic cardiomyopathy: whole heart microscopic observation with tangential sections.

By cross-section or longitudinal section, it is difficult to investigate longitudinal features of myocardial cells in the whole heart. Here, introducing the use of tangential sections to obtain longitudinal aspect of myocardial cells in any part of myocardium, the authors evaluated myocardium in the left ventricle in 10 normal hearts and four hearts with hypertrophic cardiomyopathy (HCM). Tangential sections were obtained by peeling the superficial layer of myocardium. After peeling the whole surface, secondary deep layer was peeled. These procedures were repeated more than five times through the wall. Intercalated discs (ICD) were observed immunohistochemically with anti-N-cadherin and antidesmoplakin. In normal hearts, myocardial cells were cut longitudinally and ran parallel in tangential sections. They linked end-to-end with simple and regular ICD with average lengths of 120-130 microm and average sarcomere numbers of 56-65. In HCM hearts, many myocardial cells were cut almost longitudinally running approximately parallel in tangential sections. Myocardial cells frequently showed side-to-side linking characterized by skewed ICD, indistinct ICD counterparts, and longitudinally arranged ICD. Two young HCM hearts had circle-shaped ICD and vacuole-like structures highlighted by immunostaining for N-cadherin, which were actually extracellular structures comparable with irregular side-to-side linking. It is considered that side-to-side linking of myocardial cells is a characteristic microscopic feature in HCM rather than myocardial disarray.

Physiological angiogenesis in electrically stimulated skeletal muscle in rabbits: characterization of capillary sprouting by ultrastructural 3-D reconstruction study.

Physiological angiogenesis occurs in electrically stimulated skeletal muscles. It is known to start as capillary sproutings, but has not yet been well characterized as ordinary angiogenesis. To characterize the sprouting process during physiological angiogenesis, we carried out an ultrastructural 3-D reconstruction study for the extensor digitorum longus of three adult rabbits under electrical stimulation for 7 days. In addition, hemodynamic and morphological studies were carried out after stimulation for 3, 7, and 14 days. The electrical stimulation induced a twofold increase in femoral artery blood flow and tissue blood flow. This was associated with an increase in capillary density of the muscle by more than twofold at 7 and 14 days. Sproutings frequently appeared at 7 days (4.3 +/- 1.4 x 10(3) sproutings per mm3, 13.3 +/- 6.9 microm in length). All sprouting tips consisted of endothelial cytoplasmic protrusions (ECP). Besides sproutings, there were communicating networks consisting segmentally of ECP (11.6 +/- 5.6 x 10(3) networks per mm3). Endothelial cytoplasmic protrusions began to appear at 3 days, were frequent at 7 days, and disappeared at 14 days, which corresponded well to the changes in blood flow and capillary density. We consider that in physiological angiogenesis, sproutings start as ECP, which contact other capillaries to form networks and become hollowed to form new capillary networks.

Subnormal shear stress-induced intimal thickening requires medial smooth muscle cell proliferation and migration.

Arterial intimal thickening is consisted of predominately smooth muscle cells (SMC). The source of these SMCs and mechanisms response for their changes have not been well cleared. Using a model of rabbit common carotid artery (CCA) shear induced intimal thickening, we sought to identify and describe the source of SMCs in intima. The enlarged CCA 28 days after arteriovenous fistula (AVF) creation was subjected to subnormal wall shear stress (WSS) for 1, 3, and 7 days by closure of the AVF. To determine SMC proliferation, BrdU pulse labeling of SMCs was performed. BrdU-labeled SMCs were tracked over time to further confirm SMC migration. In response to subnormal WSS intimal thickening developed progressively. BrdU-labeled SMCs localized in the subendothelial area. When the BrdU-labeled medial SMCs were tracked 1 day after AVF closure, progenies of these BrdU-incorporated SMCs increased by 4.8-fold with 75% of them in the intima. They were 12-fold increased with 83% in the intima 7 days after. En face examination showed an accumulation of SMCs in internal elastic lamina gap after AVF closure, which later migrated into subendothelial area. In situ hybridization revealed increased TGF-beta1 mRNA expression in intimal SMCs. This study demonstrates that the medial SMCs are the predominant cells in subnormal WSS-induced intimal thickening. Early expression of TGF-beta1 may play an important role in the process of intimal thickening.