Rectal cancer lateral lymph nodes: multicentre study of the impact of obturator and internal iliac nodes on oncological outcomes.

BACKGROUND: In patients with rectal cancer, enlarged lateral lymph nodes (LLNs) result in increased lateral local recurrence (LLR) and lower cancer-specific survival (CSS) rates, which can be improved with (chemo)radiotherapy ((C)RT) and LLN dissection (LLND). This study investigated whether different LLN locations affect oncological outcomes. METHODS: Patients with low cT3-4 rectal cancer without synchronous distant metastases were included in this multicentre retrospective cohort study. All MRI was re-evaluated, with special attention to LLN involvement and response. RESULTS: More advanced cT and cN category were associated with the occurrence of enlarged obturator nodes. Multivariable analyses showed that a node in the internal iliac compartment with a short-axis (SA) size of at least 7 mm on baseline MRI and over 4 mm after (C)RT was predictive of LLR, compared with a post-(C)RT SA of 4 mm or less (hazard ratio (HR) 5.74, 95 per cent c.i. 2.98 to 11.05 vs HR 1.40, 0.19 to 10.20; P < 0.001). Obturator LLNs with a SA larger than 6 mm after (C)RT were associated with a higher 5-year distant metastasis rate and lowered CSS in patients who did not undergo LLND. The survival difference was not present after LLND. Multivariable analyses found that only cT category (HR 2.22, 1.07 to 4.64; P = 0.033) and margin involvement (HR 2.95, 1.18 to 7.37; P = 0.021) independently predicted the development of metastatic disease. CONCLUSION: Internal iliac LLN enlargement is associated with an increased LLR rate, whereas obturator nodes are associated with more advanced disease with increased distant metastasis and reduced CSS rates. LLND improves local control in persistent internal iliac nodes, and might have a role in controlling systemic spread in persistent obturator nodes.Members of the Lateral Node Study Consortium are co-authors of this study and are listed under the heading Collaborators.

Genetic diversity of highly pathogenic H5N8 avian influenza viruses at a single overwintering site of migratory birds in Japan, 2014/15.

We isolated eight highly pathogenic H5N8 avian influenza viruses (H5N8 HPAIVs) in the 2014/15 winter season at an overwintering site of migratory birds in Japan. Genetic analyses revealed that these isolates were divided into three groups, indicating the co-circulation of three genetic groups of H5N8 HPAIV among these migratory birds. These results also imply the possibility of global redistribution of the H5N8 HPAIVs via the migration of these birds next winter.

Folliculocentric squamous cell carcinoma with tricholemmal differentiation: a reappraisal of tricholemmal carcinoma.

BACKGROUND: The diagnostic criteria for tricholemmal carcinoma remain controversial, and even the existence of tricholemmal carcinoma has been the subject of debate. Follicular (infundibular) squamous cell carcinoma (SCC) is a distinctive subset of SCC, which develops solely with folliculocentricity, and displays the features of conventional SCC without tricholemmal differentiation. AIM: To examine the existence of pure folliculocentric SCCs showing tricholemmal differentiation, that is, tricholemmal carcinoma. METHODS: In total, 812 SCCs were examined, and those meeting the following diagnostic criteria were selected: (i) pure folliculocentricity without any associated Bowen's disease or actinic keratosis; (ii) composition primarily of lightly eosinophilic cells or clear cells containing glycogen; (iii) columnar lightly eosinophilic or clear cells aligned in a palisade along a discernible basement membrane; (iv) tricholemmal keratinization; (v) glycogen contained within the pale/clear cells; and (vi) cytological atypia and or infiltrative growth. We also evaluated whether the immunohistochemical profile [cytokeratin (CK)1, CK10, CK17, CD34 and D2-40] seen in normal hair follicles was retained in the selected lesions. RESULTS: Only two lesions met the criteria. The immunohistochemical profile of the normal outer root sheath cells was generally retained in these lesions, except for CD34. CONCLUSIONS: Tricholemmal carcinoma is a rare occurrence, but it does exist, and at least one type of tricholemmal carcinoma is considered to be related to follicular (infundibular) SCC.

Histiocytoid and signet-ring cell carcinoma of the axilla: a type of cutaneous apocrine carcinoma equivalent to histiocytoid lobular carcinoma of the breast?

There is a histopathological similarity between cutaneous apocrine carcinoma (CAC) and breast carcinoma. Cutaneous histiocytoid or signet-ring cell (SRC) carcinoma is a rare neoplasm, which usually occurs on the eyelid, and less commonly on the axilla. The precise histogenesis of this carcinoma remains controversial. We report the case of a man with a cutaneous histiocytoid SRC carcinoma of the axilla having histopathological and immunohistochemical features that were quite similar to histiocytoid lobular carcinoma (histiocytoid LC) of the breast, which is a subtype of classic invasive lobular carcinoma of the breast with apocrine differentiation. We consider this case to be a type of CAC equivalent to histiocytoid LC of the breast, based on the features and the occurrence on the axilla. The patient was treated with adjuvant chemotherapy according to the general guidelines for the treatment of breast carcinoma.

An organotypic culture system of Merkel cells using isolated epidermal sheets.

BACKGROUND: Merkel cells (MCs) exist in the epidermal basal layer, in contact with keratinocytes. This direct contact seems critical for maintaining MCs in vitro. OBJECTIVES: To estimate the effects of nerve cells on the maintenance of MCs within epidermal sheets in a new organotypic culture system of MCs. METHODS: We developed a new organotypic culture system of MCs, using MC-containing epidermal sheets embedded in collagen gel. To estimate the effects of nerve cells on the maintenance of MCs within the epidermal sheets, we cocultured nerve cells and MC-containing epidermal sheets. In these culture assemblies, cellular behaviour was analysed by histochemistry, immunohistochemistry, electron microscopy and enzyme-linked immunosorbent assay. RESULTS: This culture, even in the absence of neurotrophin (NT)-3 and nerve growth factor (NGF) (which are crucial for MC biology), retained cytokeratin (CK)-20-positive and neuroendocrine granule-containing MCs within the sheets for over 2 weeks. Coculture of MCs with PC-12 nerve cells significantly increased the number of MCs within the epidermal sheets, and the keratinocytes had almost identical expression levels of CK1, CK10, CK14 and the progenitor marker p63 to those produced by keratinocytes in vivo. Uptake of the growth marker bromodeoxyuridine by MCs and levels of NT-3 and NGF in the culture supernatants were undetectable in this system, regardless of the presence or absence of PC-12. CONCLUSIONS: The data suggest, first, that direct contact between MCs and keratinocytes may be critical for retaining MCs in vitro; second, that nerve cell-affected maintenance of keratinocyte differentiation, but not NT-3 and NGF, may contribute to MC maintenance; and third, that MCs are not able to grow, at least in our system. Our method would be useful for studying MC biology.

Coulomb pre-stress and fault bends are ignored yet vital factors for earthquake triggering and hazard.

Successive locations of individual large earthquakes (Mw > 5.5) over years to centuries can be difficult to explain with simple Coulomb stress transfer (CST) because it is common for seismicity to circumvent nearest-neighbour along-strike faults where coseismic CST is greatest. We demonstrate that Coulomb pre-stress (the cumulative CST from multiple earthquakes and interseismic loading on non-planar faults) may explain this, evidenced by study of a 667-year historical record of earthquakes in central Italy. Heterogeneity in Coulomb pre-stresses across the fault system is >±50 bars, whereas coseismic CST is <±2 bars, so the latter will rarely overwhelm the former, explaining why historical earthquakes rarely rupture nearest neighbor faults. However, earthquakes do tend to occur where the cumulative coseismic and interseismic CST is positive, although there are notable examples where earthquake propagate across negatively stressed portions of faults. Hence Coulomb pre-stress calculated for non-planar faults is an ignored yet vital factor for earthquake triggering.

Prognostic impact of residual lateral lymph node metastasis after neoadjuvant (chemo)radiotherapy in patients with advanced low rectal cancer.

Background: There is a lack of large studies focusing on the prognostic significance of lateral lymph node (LLN) metastasis following LLN dissection (LLND) in rectal cancer. The aim of this study was to evaluate the prognostic impact of LLN metastases on survival of patients with advanced low rectal cancer. Methods: Consecutive patients with locally advanced, but not metastatic, extraperitoneal rectal cancer treated with neoadjuvant (chemo)radiotherapy plus total mesorectal excision between 2004 and 2015 were included in the study. LLND was performed when pretreatment imaging documented enlarged LLNs (7 mm or greater in size). Localization of nodal metastases and long-term outcomes were analysed. Kaplan-Meier analysis was used to compare the survival of patients with ypN0 disease with that of patients with mesorectal ypN+/LLN- status and patients with positive LLNs. The Cox proportional hazards model was used to evaluate predictors of disease-free survival (DFS) and local recurrence. Results: A total of 613 patients were included in the study; LLND was performed in 212 patients (34·6 per cent) and 57 (9·3 per cent) had LLN metastasis. Patients with LLN metastasis had improved DFS and local recurrence cumulative incidence rates compared with patients with mesorectal ypN2+/LLN- disease (DFS: P = 0·014; local recurrence: P = 0·006). Although the DFS rate of patients with LLN metastasis was worse than that of patients with ypN0 disease (P < 0·001), the cumulative incidence of local recurrence was similar (P = 0·491). In multivariable analysis, residual LLN metastasis was not an independent predictor of worse DFS or local recurrence. Conclusion: LLN metastasis is not an independent predictor of local recurrence or survival. Survival of patients presenting with LLN metastasis after (chemo)radiotherapy was intermediate between that of patients with ypN0 status and those with mesorectal ypN2 positivity.

Antecedentes: No existen en la literatura grandes estudios dirigidos a investigar la importancia pronóstica de las metástasis en los ganglios linfáticos laterales (lateral lymph nodes, LLN) después de la disección de los mismos (LLN dissection, LLND) en pacientes con cáncer de recto. El objetivo de este estudio fue evaluar el impacto pronóstico de las metástasis en los LLN sobre la supervivencia de los pacientes con cáncer de recto. Métodos: Se analizaron 613 pacientes consecutivos con cáncer de recto localmente avanzado extraperitoneal y no metastásico tratados con (quimio)radioterapia neoadyuvante seguida de resección total del mesorrecto (total mesorectal excision, TME) entre 2004 y 2015. Se realizó una LLND cuando el estudio mediante pruebas de imagen previo el tratamiento mostró LLN aumentados de tamaño ≥ 7 mm. Se analizó la localización de las metástasis ganglionares y los resultados a largo plazo. El análisis de supervivencia se realizó mediante el método de Kaplan­Meier para comparar las supervivencias de los pacientes ypN0 frente a los pacientes ypN con positividad mesorrectal/LLN negativos y frente a los pacientes LLN positivos. Se utilizó el modelo de riesgo proporcional de Cox para evaluar los factores predictivos de supervivencia libre de enfermedad y de recidiva local. Resultados: Se realizó una LLND en 212 (34,6%) pacientes, y 57 (9,3%) pacientes presentaban metástasis en los LLN. Los pacientes con metástasis en los LLN presentaron mejores curvas de incidencia acumulada de recidiva local y de supervivencia libre de enfermedad en comparación con los pacientes con ganglios mesorrectales ypN2 positivos/LLN negativos (respectivamente, P = 0,0135 y P = 0,0060). Aunque la curva de la supervivencia libre de enfermedad de los pacientes con metástasis en los LLN fue peor que la de los pacientes ypN0 (P < 0,0001), la incidencia acumulada de recidiva local fue similar (P = 0,4905). En el análisis multivariable, la metástasis residual en los LLN no fue un factor predictivo independiente de peor supervivencia libre de enfermedad ni de recidiva local. Conclusión: Las metástasis en los LLN no es un factor predictivo independiente de recidiva local o supervivencia. Los pacientes que presentaron metástasis en los LLN después de (quimio)radioterapia mostraron características de supervivencia intermedias entre ypN0 y pacientes con ganglios mesorrectales ypN2 positivos.

Effects of fluoride dentifrices on enamel lesion formation.

An in vitro pH cycling model was used to test the hypothesis that the effects of 3 different fluoride compounds on de/remineralization are a function of the free fluoride ion concentration. Groups of 10 human enamel specimens were treated with one of: (a) amine fluoride (AmF), 1250 ppm F; (b) sodium monofluorophosphate (NaMFP), 1000 ppm F; (c) sodium fluoride (NaF), 1100 ppm F; (d) NaF, 250 ppm F; (e) Placebo (< 1 ppm F) dentifrices; or with aqueous solutions (f) NaF 900 ppm F or (g) NaF 30 ppm F. Lesions were assessed by cross-sectional microhardness. Mean +/- SEM DeltaZ (vol.% x microm) values of 3 dentifrices were: (a) 344 +/- 155, (b) 4259 +/- 257, and (c) 591 +/- 83. The AmF (1250 ppm F) was not statistically significantly different from the NaF (1100 ppm F) dentifrice in this model. The NaMFP (1000 ppm F) dentifrice, without hydrolysis, had only the same efficacy as the NaF (30 ppm F) aqueous solution.

Subcutaneous adipocytes promote the differentiation of squamous cell carcinoma cell line (DJM-1) in collagen gel matrix culture.

Cancer cell-stromal cell interaction plays a crucial role in the malignant growth of cancer cells. In the skin, the main stromal cell types consist of dermal fibroblasts and subcutaneous adipocytes. Fibroblasts are shown to promote the invasive growth of various cancer cell types. The interaction between cancer cells and stromal adipocytes, however, has not been sufficiently studied even in cutaneous carcinoma. To address the effects of adipocytes on the biologic behavior of cancer cells, we examined the growth and differentiation of a squamous cell carcinoma cell line of the skin (DJM-1), using a three-dimensional collagen gel matrix culture with a cutaneous environmental factor, air exposure. The growth was estimated by the uptake of bromodeoxy-uridine (BrdU) for 24 h. The BrdU indices of DJM-1 cells in stromal-cell-free, fibroblast-containing, and adipocyte- containing conditions were 19.7 +/- 1.9%, 19.8 +/- 2.8%, and 4.7 +/- 1.4%, respectively, whereas the BrdU index on the gel containing both fibroblasts and adipocytes was 10.4 +/- 3.3%. In terms of differentiation, DJM-1 cells cocultured with adipocytes constructed the best-organized stratified layer with a cornified-like structure in all conditions above. The differentiation markers involucrin and cytokeratin 10 were immunohistochemically detected in this structure of DJM-1 cells. Adipocyte-induced phenomena were not affected distinctively by air exposure. These results indicate that adipocytes, but not fibroblasts, promote the differentiation of squamous cell carcinoma cells (DJM-1) and inhibit their growth. These adipocyte-induced phenomena were not completely inhibited by fibroblasts. In conclusion, we suggest that stromal adipocytes may be involved in the differentiating mechanisms of cutaneous carcinoma cells.

Reconstruction of thyroid follicles from isolated porcine follicle cells in three-dimensional collagen gel culture.

Thyroid follicles, an essential functional unit of the thyroid, are ball-like structures and exist in the extracellular matrix in vivo. Thus far, the follicles have not been reconstructed in any culture system. The presumed reason for that was that the in vitro environment for the follicle cells in monolayer culture markedly differed from their environment in vivo. We, therefore, considered that isolated follicle cells had to be localized in a three-dimensional environment of extracellular matrix, specifically collagen, to reconstruct thyroid follicles in vitro. At first, follicle cells were completely isolated. These cells were cultured in the three-dimensional collagen gel. An intracytoplasmic cavity first developed in individual cells. A single cell with the cavity then underwent cell division, and the follicle consisting of two cells was reconstructed. This gradually grew to be a large ball-like structure through proliferation of the component cells, and they exhibited morphological polarity specific for thyroid follicle cells. In addition, these cells clearly produced thyroid hormones. To the best of our knowledge, this report is the first instance of reconstruction of thyroid follicles in an in vitro culture system. This culture system is more useful than the monolayer culture system in that this system provides a more physiological environment for investigations of differentiation of follicle cells. Further experiments using this method will probably provide a new clue to the mechanism of thyroid folliculogenesis.

Plural cells organize thyroid follicles through aggregation and linkage in collagen gel culture of porcine follicle cells.

Some follicle cells organize thyroid follicles through proliferation of single cells in collagen gel culture. The aim of this study was to clarify whether two or more (plural) cells can form follicles through aggregation and linkage in this culture system. To address this question, we performed collagen gel culture of porcine follicle cells, using cell labeling with PKH 2 dye. A mixture of dye-labeled and nonlabeled cells was cultured in collagen gel. Organized follicles consisted of both dyed and nondyed cells. This suggested that plural cells reconstructed follicles through aggregation and linkage. To further confirm this finding, cells embedded in collagen gel were cultured in inhibition of cell proliferation with 2 micrograms/ml aphidicolin. Forty to 60 percent of the cells formed follicles, which did not grow larger. Electron microscopy showed that intracytoplasmic cavities appeared in the cells. In contrast, 20-30% of the embedded cells developed into cavity-embracing single cells, which remained signet rings. These results indicate that follicle cells organize follicles in collagen gel culture by two means: through cell division of cavity-embracing single cells and through aggregation and linkage of plural cells.

Transforming growth factor-beta1 induces a mesenchyme-like cell shape without epithelial polarization in thyrocytes and inhibits thyroid folliculogenesis in collagen gel culture.

Transforming growth factor-beta1 (TGFbeta1) induces a mesenchyme-like cell shape in some epithelial cell types. To clarify the role of TGFbeta1 in the morphological regulation of thyrocytes, we performed collagen gel culture of porcine thyrocytes with serum-free medium. TGFbeta1-nontreated cells organized follicles. In contrast, the cells treated with 10 ng/ml TGFbeta1 became spindle shaped, i.e. they resembled mesenchymal fibroblasts, and did not form follicles. To characterize the spindle-shaped cells, we examined the fine structures and expression of thyroglobulin (Tg) and cytoskeletal proteins using electron microscopy, immunohistochemistry, and immunoblotting. TGFbeta1-nontreated cells had microvilli at the apical side facing follicle lumen and had basal lamina at the basal side in contact with collagen gel. TGFbeta1-treated cells showed both microvilli and basal lamina at the basal side. TGFbeta1-nontreated cells expressed Tg, whereas TGFbeta1-treated cells showed no expression. TGFbeta1-nontreated cells barely expressed vimentin, but they expressed enough cytokeratin. TGFbeta1-treated cells extensively displayed vimentin along with the change in shape to become spindle-like and retained a decreased expression of cytokeratin. TSH (10 mU/ml) did not essentially influence any TGFbeta1 effects on the cells. These results indicate that TGFbeta1 induces a mesenchyme-like cell shape accompanied by cytoskeletal molecular change and the loss of both epithelial polarization and a function in thyrocytes, and that it results in inhibiting thyroid folliculogenesis with or without TSH.

Immunohistochemical analysis of Bcl-2, Bax, and Bak expression in thyroid glands from patients with subacute thyroiditis.

Bcl-2 family proteins are important regulators of apoptosis. To clarify a role of apoptosis and the expression of Bcl-2 family proteins in the pathogenesis of subacute thyroiditis (SAT), we evaluated the expression of Bcl-2, Bax, and Bak by immunohistochemistry and apoptosis by in situ end labeling of fragmented DNA in thyroid tissues from 11 patients with SAT. Apoptotic nuclei were found in granulomas, especially in macrophages/histiocytes and lymphocytes, and in the regenerating follicular cells, but were rarely found in the area of fibrosis. The mean (+/-SD) percentage of apoptotic follicular cells was significantly greater in SAT than that in controls (1.4 +/- 0.8% vs. 0.4 +/- 0.6%). Bcl-2, Bak, and Bax were strongly expressed in the granulomas and regenerating thyroid follicular cells from patients with SAT. Bcl-2 and Bak, but not Bax, were expressed in follicular cells from normal controls. The percentage of apoptotic cells and the expression of Bax in follicular cells did not correlate with age or serum levels of thyroid hormones, C-reactive protein, or thyroglobulin. These data suggest that apoptosis may be involved in the development of SAT and that Bax expression in regenerating thyrocytes may be important for the recovery of SAT.

Glycation decreases the stability of the triple-helical strands of fibrous collagen against proteolytic degradation by pepsin in a specific temperature range.

When fibrous collagen of rat tail tendons was glycated by incubation with ribose, it became highly insoluble in dilute acetic acid and resistant to pepsin digestion at 5 degrees C, since it was cross-linked by advanced glycation end products. Extensively glycated fibrous collagen was found to be much less stable than non-glycated control fibrous collagen against pepsin digestion at 30 degrees C. Under conditions where nearly all of the glycated fibrous collagen was degraded into small peptides by pepsin, approximately 45% of the control collagen was left as large polypeptides having nearly the whole length of its triple-helical region. A soluble collagen, which consisted primarily of the triple-helical region of monomeric collagen, was found to be glycated as efficiently as the fibrous collagen on incubation with ribose at 30 degrees C, while the rate of cross-linking of the soluble collagen was very low, suggesting that the triple-helical strands do not undergo intramolecular cross-linking and that most of the cross-links produced in the glycated fibrous collagen are intermolecular ones. The glycated soluble collagen was as stable as the control collagen against pepsin digestion at 30 degrees C. These results indicate that the triple-helical strands of glycated fibrous collagen are much less stable than those of the non-glycated form against proteolytic digestion by pepsin at a temperature close to but below their melting point. Sugar-derived intermolecular cross-links are supposed to underly the decreased stability of the triple-helical strands.

Crystallographic characterization of wild-type and mutant ribonuclease T1 complexes with several ribonucleotides.

Ribonuclease T1 and the mutant enzymes were cocrystallized with several ribonucleotides, including non-hydrolyzable substrate analogs of di- and triribonucleotides, which have a novel guanylate in which the 2'-hydroxyl group of the ribose is replaced by a fluorine atom. One of the mutant enzymes has a tryptophan residue, instead of Tyr45 of the wild-type enzyme, to enhance the binding of ribonucleotides to the enzyme and the other mutant enzyme has histidine and aspartate residues, instead of Asn43 and Asn44, respectively, to reproduce the natural substitutions found in ribonuclease Ms. Polymorphism of the crystals was observed for wild-type and mutant enzymes. However, orthorhombic crystals, which are virtually all isomorphous to each other, were successfully obtained from wild-type and mutant (Y45W) enzymes by the macroscopic seeding technique using mother crystals of the wild-type ribonuclease T1 complexed with 2'GMP or 3'GMP. The diffraction patterns of these crystals extend beyond 2.5 A resolution and the diffraction data were collected from some of the crystals on a diffractometer up to a range of 2.5 to 1.8 A resolution.

The mechanism of interaction of sodium dodecyl sulfate with elastic fibers.

Sodium dodecyl sulfate (SDS), an anionic hydrophobic ligand, is known to alter the mechanical properties of elastic fibers. In order to analyze the mechanism of the alteration, two forms of fibrous elastins, "solid" and "powder" elastins, which consisted of fascicular elastic fibers and single or oligomeric elastic fibers, respectively, were prepared from bovine aorta, and the interactions of SDS with these elastins in the presence and absence of 0.15 M NaCl were studied. The solid elastin was able to retain 1.2- to 1.4-fold larger amounts of SDS than the powder elastin under both conditions, and both elastins retained 1.2-fold or larger amounts of SDS in the presence of NaCl than in its absence. Whereas both elastins released the retained SDS gradually on repeated washing with an SDS-free buffer, the release rates from the solid elastin, especially the rate in the presence of NaCl, were much smaller than those from the powder elastin, and the solid elastin retained approximately 40% of the bound SDS under conditions where the powder elastin lost most of its SDS. The SDS-binding capacities of both elastins were significantly lower than those of soluble kappa-elastin and serum albumin, which bound SDS homogeneously on the polypeptide chains. When the washed SDS-bound solid elastin was incubated with methylene blue and examined under a microscope, most of the methylene blue-SDS complex was located at the interfiber spaces of the elastic fibers. These results suggest that SDS alters the mechanical properties of elastic fibers by binding to the interfiber spaces and surfaces of the fibers rather than by binding to the internal polypeptide chains.

Papillary carcinoma of the thyroid with exuberant nodular fasciitis-like stroma.

We describe a rare case of papillary carcinoma with extensive proliferation of stromal cells. The stromal cells were immunocytochemically positive for vimentin, alpha-smooth muscle actin and desmin, but negative for cytokeratin, epithelial membrane antigen, S-100, thyroglobulin and CD34. These results and the ultrastructure of the stromal cells, which exhibited the characteristics of both fibroblasts and smooth muscle cells, indicated an origin from myofibroblasts. We conclude that myofibroblastic proliferation may contribute to the stromal response in the slow growth of the papillary carcinoma.