Clinicopathology of pancreaticobiliary maljunction: relationship between alterations in background biliary epithelium and neoplastic development

Background/Purpose

Between 1988 and 2003, 38 patients underwent biliary resection for pancreaticobiliary maljunction (PBM). We reviewed the histopathologic findings for the surgically resected specimens to compare the clinical and pathologic features and assess the relationship between changes in the background biliary epithelium and the development of neoplasms.

Methods

Papillary hyperplasia (PHP) seen in the biliary epithelium of patients with PBM, was classified into grades 0–III in the gallbladder and grades 0–II in the extrahepatic bile duct, according to the extent, and was assessed for links with tumors in the same specimens.

Results

The incidence of gallbladder carcinoma was 13/21 in grades I–II, versus 0/16 in grade III, while the incidence of bile duct carcinoma was 4/20 in grade I versus 0/5 in grade II. Furthermore, these incidences for patients below age 50 years and age 50 or older were 1/18 versus 12/20, and 0/14 versus 6/17, respectively.

Conclusions

PHP of the biliary epithelium in PBM patients is an important precursor lesion, especially for gallbladder cancer, and the risk becomes greater with age, regardless of the type of pancreatobiliary junction (PBJ) and its location in the biliary tract.     

Autocrine regulation of cell proliferation by estradiol and hydroxytamoxifen of transformed mouse Leydig cells in serum-free culture

We have previously reported that the cloned cell line (B-1-A-2) derived from an estrogen-responsive mouse Leydig cell tumor shows an estrogen-dependent enhancement of cell proliferation in medium supplemented with charcoal-dextran-stripped fetal bovine serum. To avoid the involvement of unknown factors present in the serum in the pathway for estrogen-dependent cell growth, the present study was designed to establish a serum-free culture system to which growth factors could be added. To this end, we subcloned B-1 cells from the parental tumor cell line. The proliferation of B-1 cells was markedly stimulated by the addition of 10(-11)-10(-8) M estradiol into the serum-free medium [Eagle's Minimum Essential Medium-Ham's F-12 (1:1, vol/vol) containing 0.2% (wt/vol) BSA]. Epidermal growth factor (0.1-50 ng/ml) or insulin (0.1-50 micrograms/ml) alone or in combination with 10(-8) M estradiol did not affect the proliferation rate of B-1 cells. In contrast, a greater than 10-fold molar excess of 4-hydroxytamoxifen blocked estradiol-induced cell proliferation, while 4-hydroxytamoxifen alone failed to show a stimulatory effect on cell multiplication. Additionally, the conditioned medium collected from estradiol-stimulated cells was found to contain a growth-promoting factor(s) whose activity was not antagonized by 4-hydroxytamoxifen. Nonstimulated cells secreted a significant but low level of the growth-promoting factor. Finally, B-1 cells were found to be estrogen dependent for cell proliferation in BALB/c mice. Their growth was markedly inhibited by the administration of tamoxifen to the host mice. These results indicate that the serum-free culture system presented here is suitable for studying the autocrine mechanisms of cell growth regulated by estrogens as well as triphenylethylene compounds.     

Spontaneous improvement in a pediatric patient with peripheral T‐cell lymphoma

Peripheral T‐cell lymphoma (PTCL) is rare in children, and it has a poor prognosis compared with other types of lymphoma. We report the case of a 7‐year‐old boy with spontaneous improvement of PTCL complicated by hemophagocytic syndrome as the initial symptom. He complained of pain and swelling of the right neck and presented with high fever. Pancytopenia, liver dysfunction, elevated ferritin and soluble interleukin 2 receptor were noted on laboratory tests. Peripheral blood plasma and white blood cells were positive for Epstein–Barr virus (EBV) genome but, after several days, the fever abated and laboratory data improved. On histopathology of lymph node biopsy, he was diagnosed as having PTCL not otherwise specified (PTCL‐NOS) with EBV infection. He received no chemotherapy and was disease free at the last follow up, 6 years 8 months after onset. This is probably the first case of spontaneous improvement in PTCL‐NOS. Careful treatment planning is therefore necessary in PTCL‐NOS, given the possibility of spontaneous improvement of symptoms.     

Clinical evaluation of rounded atelectasis induced by exposure to asbestos]

We encountered 15 patients with rounded atelectasis induced by exposure to asbestos from 1992 to 1999. All patients were men whose ages ranged from 42 to 85 years, with a mean age of 64.2 +/- 11.5 years. Rounded atelectasis was present only in the right lung and two patients had 2 rounded atelectasis in the right lung. In eight cases, the rounded atelectasis was found in segment 10, while in the others, it was found in segments 4, 5, 6, 8, and 9. Although evidence of symptoms was absent, rounded atelectasis was detected in six patients through medical examinations. Others complained of chest pain and dyspnea. Thirteen patients displayed pleural plaques and only 2 patients revealed asbestosis. Malignant complications were discovered in 4 patients, of whom 3 showed primary lung cancer and 1 suffered acute myelocytic leukemia. In their occupational histories, 7 patients had been exposed to asbestos in the shipyards and 5 in the construction field. The mean period of the exposure was 25.1 +/- 12.7 years, and the latency period from the first asbestos exposure to the detection of atelectasis was 35.1 +/- 8.8 years. Five autopsied patients had more than 10,000 asbestos bodies in the lung, which indicated heavy exposure to asbestos. These results suggest that rounded atelectasis may appear after high-dose exposure to asbestos.     

Relative contributions of cardiorespiratory fitness and visceral fat to metabolic syndrome in patients with diabetes mellitus

The objective of this study was to examine the contribution of endurance fitness and visceral fat accumulation on the prevalence of metabolic syndrome in Japanese male patients with either an impaired glucose tolerance (IGT) or type 2 diabetes mellitus (DM). The subjects of this cross-sectional study consisted of 135 Japanese male patients with either IGT or type 2 DM who had not taken any medication or intervention. They were classified into three fitness categories (low, moderate, and high) based on the tertiles of their maximal oxygen uptake ( [Formula: see text] O(2)max) predicted by the Astrand nomogram using a cycle ergometer. Metabolic syndrome was defined based on the WHO criteria. The visceral fat area (VFA) was determined using a computed tomography scan. The age- and VFA-adjusted odds ratio was 3.49 (95% CI, 1.13-10.82) for subjects in the low fitness category in comparison to those in the high fitness category. We calculated the odds ratio for the prevalence of metabolic syndrome in the nine categories classified based on the three VFA and three [Formula: see text] (2)max levels. In Moderate- and Low- [Formula: see text] (2) max categories, the odds ratios increased in line with increases in the VFA level. The highest odds ratios were observed in the low fitness and high visceral fat group. In the High- [Formula: see text] O(2)max category, no significant odds ratios were observed in the Moderate- and High-VFA categories. These results indicate that a high degree of cardiorespiratory fitness positively contributed to the low prevalence of metabolic syndrome in Japanese male patients with IGT and type 2 DM.     

Severe exacerbation of hepatitis after short‐term corticosteroid therapy in a patient with “latent” chronic hepatitis B

Abstract: We present a case of severe exacerbation of hepatitis after short‐term corticosteroid therapy for chronic inflammatory demyelinating polyneuropathy (CIPD) with “latent” chronic hepatitis B showing no HBV‐related antigens and antibodies. After corticosteroid pulse therapy for CIPD, the patient had severe exacerbation of hepatitis twice. Although she did not show any hepatitis B virus (HBV)‐related antigens or antibodies, sequences of HBV were detected in serum and liver by a nested polymerase chain reaction. A sequence analysis of HBV at the second exacerbation showed that the G‐to‐A point mutation at nucleotide 1896 that converted codon 28 from tryptophan (TGG) to a stop codon (TAG) in the precore region resulted in amino acid change, which has been frequently observed in fulminant hepatitis and severe hepatitis in Japan.     

Bacterial genome reduction using the progressive clustering of deletions via yeast sexual cycling

The availability of genetically tractable organisms with simple genomes is critical for the rapid, systems-level understanding of basic biological processes. Mycoplasma bacteria, with the smallest known genomes among free-living cellular organisms, are ideal models for this purpose, but the natural versions of these cells have genome complexities still too great to offer a comprehensive view of a fundamental life form. Here we describe an efficient method for reducing genomes from these organisms by identifying individually deletable regions using transposon mutagenesis and progressively clustering deleted genomic segments using meiotic recombination between the bacterial genomes harbored in yeast. Mycoplasmal genomes subjected to this process and transplanted into recipient cells yielded two mycoplasma strains. The first simultaneously lacked eight singly deletable regions of the genome, representing a total of 91 genes and ∼10% of the original genome. The second strain lacked seven of the eight regions, representing 84 genes. Growth assay data revealed an absence of genetic interactions among the 91 genes under tested conditions. Despite predicted effects of the deletions on sugar metabolism and the proteome, growth rates were unaffected by the gene deletions in the seven-deletion strain. These results support the feasibility of using single-gene disruption data to design and construct viable genomes lacking multiple genes, paving the way toward genome minimization. The progressive clustering method is expected to be effective for the reorganization of any mega-sized DNA molecules cloned in yeast, facilitating the construction of designer genomes in microbes as well as genomic fragments for genetic engineering of higher eukaryotes.Complexities of natural biological systems make it difficult to understand and define precisely the roles of individual genes and their integrated functions. The use of model organisms with a relatively small number of genes enables the isolation of core biological processes from their complex regulatory networks for extensive characterization. However, even the simplest natural microbes contain many genes of unknown function, as well as genes that can be singly or simultaneously deleted without any noticeable effect on growth rate in a laboratory setting (Hutchison et al. 1999; Glass et al. 2006; Posfai et al. 2006). Ill-defined genes and those mediating functional redundancies both compound the challenge of understanding even the simplest life forms.Toward generating a minimal cell where every gene is essential for the axenic viability of the organism, we are pursuing strategies to reduce the 1-Mb genome of Mycoplasma mycoides JCVI-syn1.0 (Gibson et al. 2010). Because we can (1) introduce this genome into yeast and maintain it as a plasmid (Benders et al. 2010; Karas et al. 2013a); and (2) “transplant” the genome from yeast into mycoplasma recipient cells (Lartigue et al. 2009), genetic tools in yeast are available for reducing this bacterial genome. Several systems offer advanced tools for bacterial genome engineering. Here we further exploit distinctive features of yeast for this purpose.Methods for serially replacing genomic regions with selectable markers are limited by the number of available markers. One effective approach is to reuse the same marker after precise and scarless marker excision (Storici et al. 2001). We have previously used a self-excising marker (Noskov et al. 2010) six times in yeast to generate a JCVI-syn1.0 genome lacking all six restriction systems (JCVI-syn1.0 ∆1-6) (Karas et al. 2013a). Despite the advantages of scarless engineering, sequential procedures are time-consuming. When applied to poorly characterized genes with the potential to interact with other genes, some paths for multigene knockout may lead to dead ends that result from synergistic mutant phenotypes. When a dead end is reached, sequentially returning to a previous genome in an effort to find a detour to a viable higher-order multimutant may be prohibitively time-consuming.An alternative approach to multigene engineering, available in yeast, is to prepare a set of single mutants and combine the deletions into a single strain via cycles of mating and meiotic recombination (Fig. 1A; Pinel et al. 2011; Suzuki et al. 2011, 2012). With a green fluorescent protein (GFP) reporter gene inserted in each deletion locus, the enrichment of higher-order yeast deletion strains in the meiotic population can be accomplished using flow cytometry. Here we apply this method to the JCVI-syn1.0 ∆1-6 exogenous, bacterial genome harbored in yeast to nonsequentially assemble deletions for genes predicted to be individually deletable based on biological knowledge or transposon-mediated disruption data. The functional identification of simultaneously deletable regions is expected to accelerate the effort to construct a minimal genome.Open in a separate windowFigure 1.Progressive clustering of deleted genomic segments. (A) Scheme of the method. Light blue oval represents a bacterial cell. Black ring or horizontal line denotes a bacterial genome, with the orange box indicating the yeast vector used as a site for linearization and recircularization. Gray shape denotes a yeast cell. Green dot in the genome indicates a deletion replaced with a GFP marker. (B) Map of deleted regions. Orange box indicates the yeast vector sequence used for genome linearization and recircularization. Green boxes indicate regions deleted in multimutant mycoplasma strains. Blue boxes denote restriction modification (RM) systems that are also deleted in the strains. (C) Pulsed-gel electrophoresis result for deleted genomes. The starting strain was the JCVI-syn1.0 ∆1–6 strain (1062 kb). Two strains were analyzed for each design of simultaneous deletion (962 kb for eight-deletion or 974 kb for seven-deletion genome). Ladder is a set of yeast chromosomes (New England BioLabs). (D) GFP-RFP ratio sorting result. Standard sorting was compared with sorting based on a GFP-RFP ratio (Methods).