Automatic detection of early gastric cancer in endoscopic images using a transferring convolutional neural network.

Endoscopic image diagnosis assisted by machine learning is useful for reducing misdetection and interobserver variability. Although many results have been reported, few effective methods are available to automatically detect early gastric cancer. Early gastric cancer have poor morphological features, which implies that automatic detection methods can be extremely difficult to construct. In this study, we proposed a convolutional neural network-based automatic detection scheme to assist the diagnosis of early gastric cancer in endoscopic images. We performed transfer learning using two classes (cancer and normal) of image datasets that have detailed texture information on lesions derived from a small number of annotated images. The accuracy of our trained network was 87.6%, and the sensitivity and specificity were well balanced, which is important for future practical use. We also succeeded in presenting a candidate region of early gastric cancer as a heat map of unknown images. The detection accuracy was 82.8%. This means that our proposed scheme may offer substantial assistance to endoscopists in decision making.

Radial incision and cutting method for refractory stricture after nonsurgical treatment of esophageal cancer.

Strictures remaining after nonsurgical treatment for esophageal cancer are generally more refractory to endoscopic balloon dilation (EBD) when compared with anastomotic strictures. The aim of the present study was to evaluate the efficacy and safety of a radial incision and cutting (RIC) method for the treatment of refractory strictures after nonsurgical treatment of esophageal cancer. All subjects complained of grade 2 or worse dysphagia, even after at least 10 sessions of EBD. Between August 2009 and May 2012, eight consecutive patients with refractory esophageal stricture after nonsurgical treatments, including chemoradiotherapy (CRT) alone (n = 3), CRT followed by salvage endoscopic treatment (n = 3), or endoscopic submucosal dissection (ESD; n = 2), underwent the RIC procedure. After the RIC procedure, dysphagia in all the patients dramatically improved to grade 1 or 0 without any major complications; however, the long-term efficacy was unfavorable as only 37.5 % (3 /8) demonstrated adequate lumen patency at 3 months, and re-intervention was necessary in six patients (75 %).

Narrow band imaging with magnifying colonoscopy as diagnostic tool for predicting histology of early colorectal neoplasia.

BACKGROUND: The presence of abnormal microcapillaries detected by narrow band imaging (NBI) with magnifying colonoscopy has been reported to be a marker of colorectal neoplasia. AIM: To investigate prospectively if NBI with magnification could help predict the histology of early colorectal neoplasia. METHODS: A series of 104 consecutive patients with 139 colorectal lesions were studied. All lesions were detected by conventional colonoscopy and subsequently evaluated by NBI with magnification. During NBI with magnification, the microvascular architecture observed on the surface of the detected lesions, capillary patterns (CP), was divided into non-neoplastic (CP I) and neoplastic (CP II and CP III) types. Only lesions endoscopically diagnosed as CP II or CP III were included in the study. All of the lesions were resected endoscopically or surgically and examined histologically for comparison. RESULTS: Ninety-seven per cent (n = 103) of colorectal neoplastic lesions with CP II were histologically diagnosed as low-grade dysplasia. Eighty-seven per cent (n = 31) of the colorectal neoplastic lesions with CP III were high-grade dysplasia or invasive cancer. CONCLUSION: Capillary patterns observed by NBI with magnification could be used to assess the degree of atypia in early colorectal neoplasia.

Age-related accumulation of Ig V(H) gene somatic mutations in peripheral B cells from aged humans.

To investigate age-related alterations in human humoral immunity, we analysed Ig heavy chain variable region genes expressed by peripheral B cells from young and aged individuals. Three hundred and twenty-seven cDNA sequences, 163 micro and 164 gamma transcripts with VH5 family genes, were analysed for somatic hypermutation and VHDJH recombinational features. Unmutated and mutated micro transcripts were interpreted as being from naive and memory IgM B cells, respectively. In young and aged individuals, the percentages of naive IgM among total micro transcripts were 39% and 42%, respectively. D and JH segment usage in naive IgM from aged individuals was similar to that from young individuals. The mutational frequencies of memory IgM were similar in young and aged individuals. gamma transcripts, which are regarded as being from memory IgG B cells, showed a significantly higher mutational frequency (7.6%) in aged than in young individuals (5.8%) (P < 0.01). These findings suggest that VHDJH recombinational diversity was preserved, but that the accumulation of somatic mutations in the IgG VH region was increased in aged humans. The accumulation of somatic mutations in IgG B cells during ageing may imply that an age-related alteration exists in the selection and/or maintenance of peripheral memory B cells.

The effectiveness of anti-retroviral drug therapy for HIV-1 is associated with HIV-1 proviral DNA levels and viral selection.

The effect of combination anti-retroviral therapy regimens on HIV-1 proviral DNA levels in peripheral blood mononuclear cells was examined in 12 HIV-1-positive patients, using endpoint dilution polymerase chain reaction and serial cloning, and sequencing of the gag region of HIV-1. The major clone was defined as the most numerous of 10 analysed clones, and observation periods ranged from 8 months to 32 months (mean 19.7 +/- 10.2 months). In five patients (one with primary-stage HIV-1 infection) receiving three anti-retroviral drugs, HIV-1 RNA reduced to undetectable levels (i.e. < or = 100 copies/ml). HIV-1 proviral DNA and the number of major clones reduced in four of these patients. HIV-1 RNA levels reduced, but remained detectable, in five other patients. In the two remaining patients (both receiving two rather than three anti-retroviral drugs), HIV-1 RNA levels increased. These results suggest that the population of major clones may be affected when HIV-1 RNA levels reduce following combination regimens of anti-retroviral therapy.

A reduction in the number of peripheral CD28+CD8+T cells in the acute phase of influenza.

Influenza patients show a high incidence of T lymphocytopenia in the acute phase of the illness. Since CD8+ T cells play an important role in influenza virus infection, we investigated which subset of CD8+ T cells was involved in this lymphocytopenia. CD8+ T cells from eight patients with influenza A were studied for lymphocyte count, surface marker, and intracellular IFN-gamma production in the acute (days 1-3) and recovery phases (days 9-12). Total and T lymphocyte counts in the acute phase were approximately three times less than in the recovery phase; however, the CD4/8 ratio was the same in both phases. The cell count reduction in the acute phase was attributed predominantly to the CD28+ CD8+ subset, compared with the CD28- CD8+ subset. The memory/activation marker CD45RO on the CD8+ T cells was assessed. The CD28+ CD45RO- subset, a naive phenotype, was reduced significantly in number in the acute phase compared with the recovery phase. The CD28+ CD45RO+ subset, a memory phenotype, was also reduced in the acute phase, but the reduction was not statistically significant. Intracellular IFN-gamma in the CD8+ subset after mitogenic stimulation was measured by flow cytometry; the percentage of CD28+ IFN-gamma-/CD8+ subset in the acute phase was significantly less than in the recovery phase. These results indicated that the predominant reduction of peripheral CD8+ T cells in the acute phase of influenza was from naive-type lymphocytes, suggesting that these quantitative and qualitative changes of CD8+ T cells in influenza are important for understanding the immunological pathogenesis.

Evidence of B cell clonal expansion in HIV type 1-infected patients.

HIV-1 infection results in a gradual decrease in CD4(+) T cell counts and progressive immune deficiency. Increased T cell turnover in HIV-1-infected patients, which can be interpreted as T cell clonal expansion, has been thought to be relevant to its pathogenesis. To investigate whether B cell clonal expansion also occurs in HIV-1-infected patients, we examined the expressed V(H)DJ(H) gene sequences of peripheral B cells in HIV-1-infected patients with hypergammaglobulinemia. Identical V(H)DJ(H) gene rearrangements with additional nucleotide differences in V(H) genes were analyzed as a marker of clonally related B cells. From healthy individuals and HIV-1-uninfected patients with hypergammaglobulinemia, clonally related B cells were detected in none of 10 (0%) and 2 of 10 (20%), respectively. No clonally related B cells were detected in any of the nine HIV-1-infected patients with detectable viral loads and normal Ig levels (0%). In contrast, from 9 of 14 HIV-1-infected patients with hypergammaglobulinemia (64%), clonally related B cells were detected. In addition, no HIV-1-infected patients who exhibited normal Ig levels after antiretroviral therapy had clonally related B cells. These findings suggest that B cell clonal expansion is present in HIV-1-infected patients with hypergammaglobulinemia.

Hepatitis B virus genomes of chronic hepatitis patients do not contain specific mutations related to acute exacerbation.

To determine the specific viral variants associated with acute exacerbation of chronic hepatitis from hepatitis B virus (HBV) infection, we analyzed the complete nucleotide sequences of the HBV genome in serial serum samples from two chronic active hepatitis patients who seroconverted from HBeAg to anti-HBe. HBV DNA was amplified by polymerase chain reaction (PCR) and sequenced. A 1896 precore stop codon mutant (G to A at nt 1896) coexisting with the wild sequence was found in both patients prior to seroconversion from HBeAg to anti-HBe. Core promoter mutations at nucleotide positions 1762 (A to T) and 1764 (G to A) were found in both patients throughout the observation period. Mutations were observed in the HBV genome of the two patients at different time points, and there was no correlation between the mutations and liver disease or DNA polymerase levels. The nucleotide divergence rate and the composition of quasispecies in the HBV sequence at the time of acute exacerbation were almost the same as were found at other time points. These results suggest that acute exacerbation does not appear to be caused by a characteristic HBV species. The multiple factors that cause generalized HBV replication activation may contribute to acute exacerbation.

[Effect of highly active antiretroviral therapy (HAART) on hypergammaglobulinemia in HIV infected patients].

To investigate the mechanism of hypergammaglobulinemia in HIV infected patients, the effect of highly active antiretroviral therapy (HAART) on the hypergammaglobulinemia was analyzed. Involved in this study were 34 untreated, 21 HAART-effective (complete response) and 14 HAART-non-effective (partial response) patients. Serum levels of HIV-RNA and gammaglobulin and immunoglobulin (Ig) isotypes were measured. Mean HIV-RNA levels of untreated and partial response patients were 1.6 x 10(4) copies/ml and 0.4 x 10(4) copies/ml, respectively. HIV-RNA levels of all complete response patients were below 4.0 x 10(2) copies/ml. Mean gammaglobulin percentages of untreated, partial response and complete response patients were 24.4%, 21.8% and 17.9%, respectively (p < 0.01 in untreated vs complete response patients). Mean IgG levels in the three groups were 2,489 mg/dl, 1,947 mg/dl and 1,618 mg/dl, respectively (p < 0.001 in untreated vs complete response patients). IgA levels were high in some untreated patients and lower in complete response patients. IgE levels were increased in some untreated and partial response patients, but there was no significant difference among the three groups. These results suggested that the hypergammaglobulinemia found in HIV infected patients was associated with HIV replication. The activation mechanism might differ by Ig isotypes.

[Reduction of medical resources utilization by influenza vaccination for hospitalized elderly patients].

In order to evaluate the economic efficacy of influenza vaccination for the elderly inpatients, we have investigated the health insurance fee of elderly inpatients in Japan. It was revealed that the health insurance fee varied by patients largely, ranging from 7,000 yen to 90,000 yen. Primary reason of this variation was due to the existence of the same effective drugs with variant prices and there were no rules concerning the period of drug medication. Thus, it was found that it would be improper to use the medication fee as a measure in evaluating the effects of influenza vaccinations. In this study, we used the length of days of testing and medication such as oral antibiotics, blood cell count, etc. as a measure to evaluate the effect of influenza vaccination. We compared these measures among elderly hospitalized patients with influenza vaccination or without influenza vaccination by ADL. Mean length of days of oral antibiotics was 2.64 (+/- 6.40) days for those with vaccination, and 3.92 (+/- 7.31) days for those without vaccination. Mean length of days of injection antibiotics was 2.52 (+/- 5.53) days for those with vaccination, and 8.82 (+/- 15.1) days for those without vaccination. Mean length of days of cells blood counter was 2.63 (+/- 2.22) days for those with vaccination, and 4.44 (+/- 3.20) days for those without vaccination. Mean length of days of chest X-ray was 1.30 (+/- 2.07) days for those with vaccination, and 2.56 (+/- 3.49) days for those without vaccination. These results suggest that influenza vaccination reduces medical utilization of resources. It was also revealed that influenza vaccination is most effective when elderly patients who are bed-bound are vaccinated.