Ki-67 distribution, α-methylacyl-CoA racemase (AMACR) expression and mucin phenotypes are associated with non-polypoid growth in ulcerative colitis-associated neoplasia.

AIMS: Ulcerative colitis-associated neoplasia (UCAN) is characterised by multifocal tumourigenesis. A wide range of metachronous lesions have been reported to occur after endoscopic treatment of UCAN, which suggests the development of sporadic tumours in lesions treated as UCAN. Therefore, we aimed to evaluate differences of immunohistochemistry (IHC) in features and clinicopathological characteristics of intramucosal lesions in patients with ulcerative colitis (UC). METHODS AND RESULTS: We examined 35 intramucosal lesions resected for carcinoma or dysplasia by total colectomy from patients with UC and 71 sporadic adenomas (SAs) endoscopically resected from patients without UC. UC lesions were divided into the conventional UCAN group, defined as p53 mutant pattern and normal expression of ß-catenin, and the non-conventional UCAN group, defined as the rest. Ki-67 distribution, α-methylacyl-CoA racemase (AMACR) expression and mucin phenotypes were compared using IHC, and clinicopathological characteristics were investigated. Conventional and non-conventional UCAN lesions were located in the left colon and rectum. Relative to the SA lesions, UCAN lesions occurred in much younger patients and exhibited more frequent basal distribution of Ki-67 in tumour crypts. Conventional UCAN lesions tended to be non-polyploid and exhibited a higher frequency of normal AMACR expression than SA lesions. UC lesions were heterogeneous-only two of the eight patients with multiple lesions had lesions (both non-conventional UCAN lesions) exhibiting concordant IHC staining features. CONCLUSIONS: The basal pattern of Ki-67 distribution, normal expression of AMACR and a non-intestinal mucin phenotype were determined as characteristic features suggestive of UCAN. Non-polypoid growth was another a key feature of UCAN.

Keratin 6A Is Expressed at the Invasive Front and Enhances the Progression of Colorectal Cancer.

Keratins (KRTs) are intermediate filament proteins in epithelial cells, and they are important for cytoskeletal organization. KRT6A, classified as a type II KRT, is normally expressed in stratified squamous epithelium and squamous cell carcinomas. Little is known about the expression and role of KRT6A in adenocarcinomas. We investigated the clinicopathologic and molecular biological significance of KRT6A in colorectal adenocarcinoma. Immunostaining of colorectal adenocarcinoma cases treated at our institution demonstrated that KRT6A showed significantly stronger expression at the invasive front than that at the tumor center (P < .0001). The high KRT6A-expression cases (n = 47) tended to have a high budding grade associated with significantly worse prognoses. A multivariate analysis revealed that the KRT6A expression status was an independent prognostic factor for overall survival (P = .0004), disease-specific survival (P = .0097), and progression-free survival (P = .0033). The correlation between KRT6A and patient prognoses was also validated in an external cohort from a published data set. To determine the function of KRT6A in vitro, KRT6A was overexpressed in 3 colon cancer cell lines: DLD-1, SW620, and HCT 116. KRT6A overexpression increased migration and invasion in DLD-1 but did not in SW620 and HCT116. In 3-dimensional sphere-forming culture, KRT6A expression enhanced the irregular protrusion around the spheroid in DLD-1. Our findings in this study indicated that KRT6A expression is a valuable prognostic marker of colorectal cancer and KRT6A may be involved the molecular mechanism in the progression of invasive areas of colorectal cancer.

Longitudinal and regional association between dietary factors and prevalence of Crohn's disease in Japan.

Although a Western diet has been identified as a risk factor for Crohn's disease (CD), there is still controversy surrounding the specific foods that may contribute to the development of the disease. In this study, we examined the association between food intake and the prevalence of CD in Japan, as Japanese patients with CD are known to have limited genetic involvement. We identified changes in food intake associated with an increase in the number of patients with CD by analyzing the per capita consumption of food types from 1981 to 2014. Additionally, we examined the association between CD prevalence and food intake in each prefecture. Finally, the relationship between food intake and estimated age at CD onset was also investigated. Between 1981 and 2014, we observed Increased consumption of meat, eggs, milk and dairy products, oil, and potatoes and decreased consumption of grains, beans, vegetables, fruit, fish, sugar, and seaweed. The annual incidence of CD increased by 1388% over the same period. We found that meat consumption was significantly associated with CD prevalence (ß = 0.503, p = 0.0003), while a significant negative correlation was observed between CD prevalence and fruit and vegetable consumption (fruit, ß = 0.464, p = 0.0012; vegetables, ß = 0.404, p = 0.0023). Furthermore, we estimated that the peak consumption of more meat and less fruit and vegetables and the peak age of CD onset occurred within the age range of 20-24 years. Our study identified a clear correlation between the consumption of meat, fruits, and vegetables and the prevalence of CD in Japan. Additionally, we found an association between meat, fruit, and vegetable consumption and the age at CD onset.

Unencapsulated thymoma: a case report.

Thymomas, the most common mediastinal tumors, form capsules. Only a few reports have presented small thymomas without capsule formation, so-called microthymomas. Here, we report a case of an unencapsulated thymoma measuring 18 mm. A 42-year-old female presented with an anterior mediastinal tumor. Computed tomography revealed an 18-mm nodule in the anterior mediastinum. Magnetic resonance imaging revealed a solid tumor that was iso-intense on T1-weighted images and hypo-intense on T2-weighted images. Thoracoscopic partial thymectomy was performed. The histopathological diagnosis was a type B1 thymoma. The tumor was localized within the thymic tissue lacked a fibrous capsule and partially invaded the surrounding fat tissue. To our knowledge, this is the first report of an unencapsulated thymoma, except for microthymomas.

Value of apparent diffusion coefficient on MRI for prediction of histopathological type in anal fistula cancer.

The main histopathological types of anal fistula cancers are mucinous adenocarcinoma and tubular adenocarcinoma. The purpose of this study was to investigate the utility of the apparent diffusion coefficient (ADC) value in magnetic resonance imaging (MRI) to determine the histopathological type of an anal fistula cancer, and to investigate the relationship between ADC values and histopathological type (mucinous type or tubular carcinoma), clinical information, and surgical findings. We retrospectively identified 69 patients diagnosed with anal fistula cancer at our hospital from January 2013 to December 2021. Among them, we selected the patients diagnosed using the same 1.5-T MRI machine, underwent surgery, and a pathological sample was obtained during the operation. Finally, these 25 patients were selected for the analysis since they underwent the imaging scan using the same MRI machine. The ADC value was compared between mucinous and tubular adenocarcinomas, and between tumors at the Tis-T1-T2 and T3-T4 stages. Finally, 25 patients were selected. The mean age of the 25 patients included in the analysis was 60.8 ± 13.3 years and all were males. The median ADC of anal fistula cancers was 1.97 × 10-3 mm2/s for mucinous adenocarcinomas and 1.36 × 10-3 mm2/s for tubular adenocarcinomas; this difference was statistically significant (P < .01). Furthermore, the median ADC was 1.62 × 10-3 mm2/s for tumors in Tis-T1-T2 stages and 2.01 × 10-3 mm2/s for T3-T4 tumors (P = .02). The ADC value in MR images may predict the histopathological type and depth of anal fistula cancers. Also, the different ADC values between Tis-T1-T2 and T3-T4 tumors could help predict the classification of progression.

Vitamin D Receptor Mediates Attenuating Effect of Lithocholic Acid on Dextran Sulfate Sodium Induced Colitis in Mice.

Bile acids are major components of bile; they emulsify dietary lipids for efficient digestion and absorption and act as signaling molecules that activate nuclear and membrane receptors. The vitamin D receptor (VDR) is a receptor for the active form of vitamin D and lithocholic acid (LCA), a secondary bile acid produced by the intestinal microflora. Unlike other bile acids that enter the enterohepatic circulation, LCA is poorly absorbed in the intestine. Although vitamin D signaling regulates various physiological functions, including calcium metabolism and inflammation/immunity, LCA signaling remains largely unknown. In this study, we investigated the effect of the oral administration of LCA on colitis in a mouse model using dextran sulfate sodium (DSS). Oral LCA decreased the disease activity of colitis in the early phase, which is a phenotype associated with the suppression of histological injury, such as inflammatory cell infiltration and goblet cell loss. These protective effects of LCA were abolished in VDR-deleted mice. LCA decreased the expression of inflammatory cytokine genes, but this effect was at least partly observed in VDR-deleted mice. The pharmacological effect of LCA on colitis was not associated with hypercalcemia, an adverse effect induced by vitamin D compounds. Therefore, LCA suppresses DSS-induced intestinal injury in its action as a VDR ligand.

Crohn's disease may promote inflammation in IgA nephropathy: a case-control study of patients undergoing kidney biopsy.

Intestinal immunity has been closely associated with the pathogenesis and progression of renal diseases, a relationship known as the "gut-kidney axis." To determine the association between immunoglobulin A nephropathy (IgAN) and Crohn's disease (CD), a clinico-pathological study was performed on patients who had IgAN with CD (CD-IgAN) and without CD (NOS-IgAN). We enrolled 29 patients diagnosed with IgAN via renal biopsy at the Tokyo Yamate Medical Center from 2009 to 2017. The patients were divided into CD-IgAN (n = 18) and NOS-IgAN (n = 11) and evaluated for clinical and pathological findings. IgA subclasses and galactose-deficient IgA1 (Gd-IgA1) were examined via immunohistochemistry using formalin-fixed paraffin-embedded sections from renal biopsy. Our results showed no significant difference in the extent of mesangial IgA subclasses or Gd-IgA1 deposition according to the presence or absence of CD. Pathologically, however, those with CD-IgAN had remarkably higher percentage of global glomerulosclerosis and extent of interstitial fibrosis and tubular atrophy (IF/TA) compared to those with NOS-IgAN. Moreover, the extent of macrophage infiltration in the glomerulus and interstitium was significantly higher in CD-IgAN than in NOS-IgAN. Clinically, the CD-IgAN group had significantly worse responsiveness to steroid treatment compared to the NOS-IgAN group. In conclusion, the similar immunological characteristics of deposited IgA molecules in the glomeruli between the CD-IgAN and NOS-IgAN groups might suggest their etiological similarity. However, a renal pathology showing advanced glomerular and tubulointerstitial sclerosis accompanying increased macrophage infiltration and highly resistant clinical features in patients with CD-IgAN suggests that some pathophysiological factors in CD, including abnormal intestinal immunity, may promote and activate the inflammatory process in IgAN via undetermined mechanisms.

Atypical Splenic Abscesses Due to Clostridioides difficile.

BACKGROUND Splenic abscess is a rare infectious disease that occurs after bloodstream infection and trauma. It has become more common due to an increase in the number of immunocompromised patients. They typically present with round cystic lesions demonstrated by ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI). Clostridioides difficile (formerly Clostridium difficile) is a well-known cause of pseudomembranous colitis, but extraintestinal manifestations are very rare. To the best of our knowledge, only 9 cases of splenic abscess due to C. difficile have been reported in the literature. CASE REPORT A 90-year-old man presented with weight loss, fever, and abdominal pain. Contrast-enhanced CT revealed splenomegaly with irregular hypodense nodules. Image-guided biopsy or drainage was not performed for a technical reason. MRI showed atypical nodules with mixed high and low signals on both T1- and T2-weighted images, which were inconclusive. A laparoscopic splenectomy was performed, which resulted in partial removal due to severe adhesion of the spleen to the surrounding tissues. Cultures of splenic pus yielded C. difficile, Enterococcus faecium, and Bacteroides fragilis. Pathological examination of the spleen showed widespread abscesses with hemorrhage and necrosis, leading to the diagnosis of splenic abscesses. Intravenous administration of vancomycin, clindamycin or metronidazole was ineffective. He died of fatal arrhythmia 5 months after the initial diagnosis of splenic abscess. CONCLUSIONS Splenic abscess can present with atypical imaging findings owing to chronic inflammation, bleeding, and necrosis. Although polymicrobial, this is the tenth reported case of splenic abscess caused by C. difficile.

Enhanced oxidative phosphorylation of IgG plasma cells can contribute to hypoxia in the mucosa of active ulcerative colitis.

Mucosal hypoxia is detected in the mucosa of ulcerative colitis (UC), however the mechanism and the cause of hypoxia is not fully understood, while a dense infiltration of plasma cells is observed in the inflamed mucosa of UC. When differentiating from a B cell to a plasma cell, the energy metabolism dramatically shifts from glycolysis to oxidative phosphorylation, which results in a large amount of oxygen consumption of the plasma cell. We hypothesized that the plasma cell infiltration into the inflamed mucosa contributes to the mucosal hypoxia in UC in part. We examined the association between mucosal hypoxia and plasma cell infiltration in UC. More IgG plasma cells (but not IgA plasma cells) were distributed, and the nuclear and cell sizes were enlarged in hypoxic mucosa compared to normoxic mucosa in UC. Oxidative phosphorylation signature genes of these IgG plasma cells were markedly upregulated compared to those of other lymphoid cells infiltrating the lamina propria of inflamed mucosa of UC. Enlarged IgG plasma cells, which increase in number in the inflamed mucosa of UC, can be related to the hypoxic state of the inflamed mucosa of UC.

Primary pulmonary epithelioid sarcoma: a case report.

BACKGROUND: Epithelioid sarcoma most frequently occurs in the dermal or subcutaneous area of the distal extremities. To date, there have been three cases of primary pulmonary epithelioid sarcoma reported. We report a case of epithelioid sarcoma that is considered a primary lung tumor. CASE PRESENTATION: A 65-year-old asymptomatic Asian male patient underwent chest radiography during a routine health examination, and an abnormal mass was detected. His past medical history was unremarkable. He smoked 40 cigarettes every day and had slightly obstructive impairment on spirometry. He worked as an employee of a company and had no history of asbestos exposure. He underwent partial resection of the right lung by thoracoscopy. A histological examination of the tumor revealed a cellular nodule of epithelioid and spindle-shaped cells. Some of the tumor cells displayed rhabdoid features and reticular arrangement in a myxomatous stroma. Immunohistochemically, the tumor cells were positive for vimentin, smooth muscle actin (SMA), CD34, and epithelial membrane antigen (EMA); loss of the BAF47/INI1 protein in the tumor cells was also confirmed. A diagnosis of epithelioid sarcoma was established. Careful screening by whole-body positron emission tomography for another primary lesion after surgery did not detect any possible lesion. He had no cutaneous disease. CONCLUSION: To our knowledge, this is the fourth case of a proximal-type epithelioid sarcoma considered as a primary lung tumor.

Oral granuloma in a pediatric patient with chronic graft-versus-host disease: A case report.

BACKGROUND: Oral mucositis is often observed with graft-versus-host disease (GVHD); however, the occurrence of oral granuloma is rare. The rapid increase in granulomatous lesions should be distinguished from malignant tumors in patients with GVHD because malignant diseases can develop in those patients. This case is the youngest pediatric patient with granuloma associated with GVHD. CASE SUMMARY: The patient was a 1-year and 5-mo-old girl who presented to our department for the management of oral nodules. At the age of 5 mo, she was diagnosed with primary immunodeficiency disease, cord blood transplant was performed at 11 mo and bone marrow transplant at 1 year of age. After transplantation, GVHD and oral mucositis developed, and tacrolimus was administered. Interestingly, nodules appeared on the lower lip and buccal mucosa, which spontaneously disappeared. Then, a new nodule appeared on the left lateral border of the tongue. Resection was performed and the histopathological diagnosis was granuloma. The origin of these nodules were considered to be the fibroblasts activated under inflammation caused by GVHD because the calcineurin inhibitor tacrolimus acted on their proliferation. CONCLUSION: It is very important to distinguish oral granulomatous lesions from malignancies if GVHD is present at the base and if immunosuppressive agents and steroids are being administered.

[Multiple Minute Pulmonary Meningothelial-like Nodules;Report of a Case].

A 57-year-old woman was referred to our hospital for investigation of multiple tiny nodules in the lung fields bilaterally on computed tomography (CT). Video-assisted thoracoscopic lung biopsy was performed to diagnose the pulmonary lesions. Histological analysis showed nodular lesions with interstitial proliferation of uniform, round to oval cells with variable widening of the alveolar septa. Immunohistochemically, the cells were positive for EMA, CD56 and the progesterone receptor, but negative for chromogranin and synaptophysin. The diagnosis was "diffuse pulmonary meningotheliomatosis", with multiple diffuse "minute pulmonary meningothelial-like nodules". Diffuse pulmonary meningotheliomatosis should be kept in mind when we encounter small nodular shadows on a CT scan.

Epithelioid Cell Granulomas in Crohn's Disease Are Differentially Associated With Blood Vessels and Lymphatic Vessels: A Sequential Double Immunostaining Study.

Crohn's disease (CD) is a gastrointestinal disorder of unknown etiology. CD-specific longitudinal ulcers show an association between disease pathogenesis and vasculature dysfunction. Granulomatous lymphangitis may also contribute to CD pathogenesis; meanwhile, vasculitis is the primary CD lesion. We investigated the association between granulomas and lymphatic and blood vessels to assess the role of vasculature in CD pathogenesis. Two small and large intestine specimens were obtained from four CD patients. From each specimen, 160 sequential sections were obtained and double immunohistochemical stained to label lymphatic and blood vessels in association with granulomas. We found that 289 of 342 granulomas (85%) were associated with a lymphatic vessel and 313 of 364 granulomas (86%) were associated with a blood vessel. Although intrablood vessel granulomas were not detected, intralymphatic vessel granulomas were. In the internal region of the granuloma, we found more blood vessels than lymphatic vessels. Hence, these results cumulatively demonstrate that CD epithelioid cell granulomas are differentially associated with lymphatic and blood vessels, suggesting both as essential for the formation and maintenance of these granulomas. Moreover, both lymphatic and blood vessels may participate in granulomatous inflammation in the primary CD lesions; however, additional studies with larger numbers of participants are required to validate our findings.

[Pancreatic Pleural Effusion;Report of a Case].

A 50-year-old man was admitted with respiratory failure. Chest X-ray and computed tomography revealed massive left pleural effusion and mediastinal shift. Pleural effusion showed abnormally high amylase levels of 42,600 IU/l and a high protein level of 3.2 g/dl. The serum amylase level was also 42,100 IU/l, and the proportion of pancreatic-type amylase was 88%. We diagnosed the patient with pancreatic effusion. Chest and abdominal enhanced computed tomography and magnetic resonance cholangiopancreatography revealed no pancreaticopleural fistula. He underwent a thoracoscopic examination that revealed brown pleural effusion as well as fibrin clots and thickness of the pleura. Histologically, there was no malignancy and the cause of pleural effusion was considered to be chronic pancreatitis.

A case of immunoglobulin G4-related inflammatory pseudotumor mimicking renal cell carcinoma.

In a 69-year-old woman with a history of Mikulicz's disease, a hypoechoic solitary renal mass was identified on routine ultrasound examination. Based on the findings of computed tomography (CT) and magnetic resonance imaging (MRI), renal cell carcinoma was a possible diagnosis. Subsequent partial nephrectomy revealed a mass characterized by an increased number of blood vessels, internal hemorrhage, and a thick fibrous capsule. Immunohistochemically, the mass comprised of tubulointerstitial nephritis with increased immunoglobulin (Ig)G4-positive plasma cells and fibrosis. Generally, diagnosis of IgG4-related kidney disease (IgG4-RKD) is not difficult when the kidney is involved together with other systemic involvements. However, diagnosis becomes harder when a solitary renal mass appears as a single-organ involvement. On precise review of our imaging findings, MRI signals were markedly affected by hemorrhage, so the mass showed hypointensity on both T1- and T2-weighted imaging, and the signal of in-phase images decreased. Dynamic MRI showed no apparent enhancement of the mass, while CT showed an apparent enhancement effect. Capsule formation was another key finding for IgG4-RKD and was recognized as a gradually enhancing boundary zone surrounding the mass on both CT and MRI. When a solitary renal mass is associated with hemorrhage and thick capsule formation, inflammatory pseudotumor should be considered as differential diagnosis.

Adenocarcinoma within anorectal fistulae: different clinicopathological characteristics between Crohn's disease-associated type and the usual type.

Adenocarcinoma within anorectal fistulae is rare and is sometimes associated with Crohn's disease. Crohn's disease-associated adenocarcinoma within anorectal fistulae has a poor prognosis; however, little is known about the clinicopathological differences between Crohn's disease-associated adenocarcinoma within anorectal fistulae and usual adenocarcinoma within anorectal fistulae. We retrospectively searched patients' charts and pathology archives at Tokyo Yamate Medical Center and Tokyo Medical and Dental University Hospital for adenocarcinoma within anorectal fistulae. Clinical and pathological data were collected and immunohistochemical examinations were conducted. Overall survival rate was estimated using the Kaplan-Meier method. Prognostic factors of overall survival were assessed using univariate and multivariate Cox regression analyses. We examined 82 cases of adenocarcinoma within anorectal fistulae. Fifty-nine of 82 cases (72%) had usual adenocarcinoma within anorectal fistulae, while the remaining 23 cases (28%) had Crohn's disease-associated adenocarcinoma within anorectal fistulae. Patients with Crohn's disease-associated adenocarcinoma within anorectal fistulae were diagnosed at a younger age and at a more advanced stage than those with usual adenocarcinoma within anorectal fistulae. Macroscopic and histological types were also different between usual adenocarcinoma within anorectal fistulae and Crohn's disease-associated adenocarcinoma within anorectal fistulae. Crohn's disease-associated adenocarcinoma within anorectal fistulae included more ulcerative types and high-grade adenocarcinomas. The rate of lymphovascular invasion was higher in Crohn's disease-associated adenocarcinoma within anorectal fistulae. Immunohistochemically, the expression of E-cadherin, p53, and MUC5AC differed between usual adenocarcinoma within anorectal fistulae and Crohn's disease-associated adenocarcinoma within anorectal fistulae. Patients with Crohn's disease-associated adenocarcinoma within anorectal fistulae exhibited worse overall survival than those with usual adenocarcinoma within anorectal fistulae, and vascular invasion was the strongest significant independent predictor of overall survival in patients with adenocarcinoma within anorectal fistulae. In conclusion, usual adenocarcinoma within anorectal fistulae and Crohn's disease-associated adenocarcinoma within anorectal fistulae have different clinicopathological characteristics and should be considered separate clinical entities.

Glutamic Acid Decarboxylase Autoantibody-negative Slowly Progressive Type 1 Diabetes Mellitus: A Case Report and Literature Review.

A 59-year-old non-obese Japanese woman developed diabetes mellitus with a negative glutamic acid decarboxylase autoantibody (GADA) test result. Her hyperglycemia was initially well controlled by oral hypoglycemic agents; however, despite continued treatment the hyperglycemia gradually worsened. As she had endogenous insulin deficiency and tested positive for insulin autoantibody (IAA), insulin therapy was initiated. Few studies have investigated GADA-negative patients with slowly progressive type 1 diabetes mellitus (SPT1D). Our IAA-positive SPT1D patient progressed from the clinical onset of diabetes mellitus to starting insulin therapy relatively quickly (1.5 years), similarly to other previously reported non-obese patients with GADA-positive SPT1D.

Macroscopic Localized Subicular Thinning as a Potential Indicator of Amyotrophic Lateral Sclerosis.

Subicular degeneration occurs in amyotrophic lateral sclerosis (ALS) patients. However, it was unknown whether microscopic subicular degeneration could be observed as macroscopic changes and whether these changes were associated with the transactive-response DNA binding protein 43 kDa (TDP-43) pathology. Topographic differences between subicular degeneration caused by ALS and Alzheimer disease (AD) had also not been characterized. Here we investigated the subiculum and related areas in autopsied brains from 3 ALS and 3 AD patients. Macroscopic subicular thinning and corresponding astrocytosis were pronounced in ALS compared to AD. This thinning was frequently accompanied by TDP-43 pathology in the transentorhinal cortex and nucleus accumbens. The preferential susceptibility of the perforant pathway to TDP-43 deposition may be an underlying cause of subicular thinning in ALS.

Therapeutic efficacy of peramivir against H5N1 highly pathogenic avian influenza viruses harboring the neuraminidase H275Y mutation.

High morbidity and mortality associated with human cases of highly pathogenic avian influenza (HPAI) viruses, including H5N1 influenza virus, have been reported. The purpose of the present study was to evaluate the antiviral effects of peramivir against HPAI viruses. In neuraminidase (NA) inhibition and virus replication inhibition assays, peramivir showed strong inhibitory activity against H5N1, H7N1 and H7N7 HPAI viruses with sub-nanomolar activity in enzyme assays. In H5N1 viruses containing the NA H275Y mutation, the antiviral activity of peramivir against the variant was lower than that against the wild-type. Evaluation of the in vivo antiviral activity showed that a single intravenous treatment of peramivir (10 mg/kg) prevented lethality in mice infected with wild-type H5N1 virus and also following infection with H5N1 virus with the H275Y mutation after a 5 day administration of peramivir (30 mg/kg). Furthermore, mice injected with peramivir showed low viral titers and low levels of proinflammatory cytokines in the lungs. These results suggest that peramivir has therapeutic activity against HPAI viruses even if the virus harbors the NA H275Y mutation.

Failing Left Ventricles Have an Enhanced Post-Stimulation Potentiation Despite Their Impaired Force Frequency Relationship.

The left ventricular contractile force (LV dP/dtmax) of patients with left ventricular systolic dysfunction does not increase effectively with an increase in heart rate. In other words, their force-frequency relationship (FFR) is impaired. However, it is unknown whether a longer coupling interval subsequent to tachycardia causes a stronger contraction (poststimulation potentiation, PSP) in a rate-dependent manner.In 16 patients with idiopathic dilated cardiomyopathy (DCM) (48 ± 2 years old, LVEF 30 ± 10%) and 6 control patients (58 ± 4 years old, LVEF 70 ± 7%), FFR was assessed by right atrial pacing using a micro-manometer-tipped catheter. At each pacing rate, the increase of LV dP/dtmax over basal LV dP/dt (ΔFFR) and the increase of LV dP/dtmax of the first beat after pacing cessation over LV dP/dtmax during pacing (ΔPSP) were evaluated.Patients with DCM had smaller LV dP/dtmax at baseline (872 ± 251 versus 1370 ± 123 mmHg/second, P = 0.0002) and developed smaller ΔFFR (eg, at 120/minute, 77 ± 143 versus 331 ± 131 mmHg/second, P = 0.0011). In contrast, they showed a rate-dependent increase of LV dP/dtmax of PSP and had greater ΔPSP (eg, at 120/minute, 294 ± 173 versus -152 ± 131 mmHg/second, P < 0.0001).Failing left ventricles develop little contractile force during tachycardia despite their rate-dependent enhancement in post-stimulation potentiation, suggesting that refractoriness of contractile force underlies impaired FFR.