Tubular Growth Research Articles

Tubular perfusion system for chondrocyte culture and superficial zone protein expression.

Tissue engineering is an alternative method for articular cartilage repair. Mechanical stimulus has been found to be an important element to the healthy development of chondrocytes and maintenance of their native phenotype. To enhance nutrient transport and apply mechanical stress, we have developed a novel bioreactor, the tubular perfusion system (TPS), to culture chondrocytes in three-dimensional scaffolds. In our design, chondrocytes are encapsulated in alginate scaffolds and placed into a tubular growth chamber, which is perfused with media to enhance nutrient transfer and expose cells to fluid flow. Results demonstrate that TPS culture promotes the proliferation of chondrocytes compared to static culture as shown by DNA content and histochemical staining. After 14 days of culture, low messenger RNA expression of proinflammatory and apoptotic markers in TPS bioreactor culture confirmed that a flow rate of 3 mL/min does not damage the chondrocytes embedded in alginate scaffolds. Additionally, cells cultured in the TPS bioreactor showed increased gene expression levels of aggrecan, type II collagen, and superficial zone protein compared to the static group, indicative of the emergence of the superficial zone specific phenotype. Therefore, the TPS bioreactor is an effective means to enhance the proliferation and phenotype maintenance of chondrocytes in vitro.

Overexpression of the tomato pollen receptor kinase LePRK1 rewires pollen tube growth to a blebbing mode.

The tubular growth of a pollen tube cell is crucial for the sexual reproduction of flowering plants. LePRK1 is a pollen-specific and plasma membrane-localized receptor-like kinase from tomato (Solanum lycopersicum). LePRK1 interacts with another receptor, LePRK2, and with KINASE PARTNER PROTEIN (KPP), a Rop guanine nucleotide exchange factor. Here, we show that pollen tubes overexpressing LePRK1 or a truncated LePRK1 lacking its extracellular domain (LePRK1ΔECD) have enlarged tips but also extend their leading edges by producing "blebs." Coexpression of LePRK1 and tomato PLIM2a, an actin bundling protein that interacts with KPP in a Ca(2+)-responsive manner, suppressed these LePRK1 overexpression phenotypes, whereas pollen tubes coexpressing KPP, LePRK1, and PLIM2a resumed the blebbing growth mode. We conclude that overexpression of LePRK1 or LePRK1ΔECD rewires pollen tube growth to a blebbing mode, through KPP- and PLIM2a-mediated bundling of actin filaments from tip plasma membranes. Arabidopsis thaliana pollen tubes expressing LePRK1ΔECD also grew by blebbing. Our results exposed a hidden capability of the pollen tube cell: upon overexpression of a single membrane-localized molecule, LePRK1 or LePRK1ΔECD, it can switch to an alternative mechanism for extension of the leading edge that is analogous to the blebbing growth mode reported for Dictyostelium and for Drosophila melanogaster stem cells.

Intestinal regulation of urinary sodium excretion and the pathophysiology of diabetic kidney disease: a focus on glucagon-like peptide1 and dipeptidyl peptidase4.

The tubular hypothesis of glomerular filtration and nephropathy in diabetes is a pathophysiological concept that assigns a critical role to the tubular system, including proximal tubular hyper-reabsorption and growth, which is relevant for early glomerular hyperfiltration and later chronic kidney disease. Here we focus on how harnessing the bioactivity of hormones released from the gut may ameliorate the early effects of diabetes on the kidney in part by attenuating proximal tubular hyper-reabsorption and growth. The endogenous tone of the glucagon-like peptide1 (GLP-1)/GLP-1 receptor (GLP-1R) system and its pharmacological activation are nephroprotective in diabetes independent of changes in blood glucose. This is associated with suppression of increases in kidney weight and glomerular hyperfiltration, which may reflect, at least in part, its inhibitory effects on tubular hyper-reabsorption and growth. Inhibition of dipeptidyl peptidase4 (DPP-4) is also nephroprotective independent of changes in blood glucose and involves GLP-1/GLP-1R-dependent and -independent mechanisms. The GLP-1R agonist exendin-4 induces natriuresis via activation of the GLP-1R. In contrast, DPP4 inhibition increases circulating GLP-1, but drives a GLP-1R-independent natriuretic response, implying a role for other DPP-4 substrates. The extent to which the intrarenal DPP-4/GLP-1 receptor system contributes to all these changes remains to be established, as does the direct impact of the system on renal inflammation.

Benign multicystic peritoneal mesothelioma associated with partial spontaneous regression in an aged cow

This article describes a benign multicystic peritoneal mesothelioma presenting partial spontaneous regression in a 16-year-old Japanese Shorthorn cow, which exhibited innumerable fluid-filled cysts (<20 cm diameter) distributing throughout the serosal surface of the peritoneal cavity on postmortem examination. Each cyst was further subdivided into several daughter cysts. On histopathology, these cystic structures consisted of multiloculated irregular spaces that contained serous fluid positive for Alcian blue stain and periodic acid-Schiff (PAS) reaction and were lined by neoplastic mesothelial cells arranged in a single to multicell layers. In some places, neoplastic cells exhibited a tubular, papillary, villous-like, or peninsular growth pattern. Neoplastic cells exhibited mild anisocytosis and anisokaryosis with very low mitotic rate. Immunohistochemically, all or some of neoplastic cells were positive for cytokeratin or vimentin, respectively. Some smaller cysts represented abundant sclerotic stroma in association with fewer shrunken neoplastic cell-lined tubules enclosed by dense fibrocollagenous stroma, collagen fiber collapse, infiltrates of lymphocytes and macrophages disposing of collagen fiber debris, and many capillaries. These findings raised the likelihood that a specific process operating partial spontaneous regression might have been implicated in this tumor. The precise mechanism underlying this phenomenon remains uncertain, although the role of abundant sclerotic stroma was highlighted.

HCC prevalence and histopathological findings in liver explants of patients with hereditary tyrosinemia type 1.

Untreated tyrosinemia type 1 (HT1) is manifested by liver failure associated with renal tubular dysfunction, growth failure, and rickets. The indication for liver transplantation (LT) is restricted to non-responders to 2-(2-nitro-4-trifluoromethylbenzoyl)-1, 3-cyclohexanedione (NTBC) treatment, patients not treated with NTBC or for patients with HCC. The aim of this study is to report on a series of NTBC naive HT1 patients submitted to LT along with the prevalence of HCC in their liver explants. This is a retrospective study of 16 children with HT1 who underwent liver transplantation between January 1993 and December 2012. liver failure in 12 (75%), growth failure in 4 (25%), rickets in 5 (31.2%), hypertrophic cardiomyopathy in three (18.7%), and renal tubulopathy in seven patients (43.7%). Median AFP level was 64,335 ng/ml. Abdominal CT scans showed multiple nodules in most patients. Histopathology of the explants showed cirrhosis in all patients and HCC in 12 (75%), 3 with microvascular invasion. The majority of the tumors were well differentiated. Patient survival rate was 86% at a median follow-up of 6.6 years. All survivors were tumor-free with no adjuvant chemotherapy. In countries where neonatal screening programs are not effective and NTBC treatment is not widely available, LT still plays an important role in the treatment of children with HT1. An early indication in patients who present with multinodular livers can also serve to treat an otherwise underdiagnosed HCC condition.

Sodium/Glucose Cotransporter 2 Inhibitors and Prevention of Diabetic Nephropathy: Targeting the Renal Tubule in Diabetes

Optimal prevention and treatment of chronic kidney disease in diabetes requires implementing therapies that specifically interfere with the pathogenesis of diabetic nephropathy. In this regard, significant attention has been given to alterations of the proximal tubule and resulting changes in glomerular filtration rate. At the onset of diabetes mellitus, hyperglycemia causes increases in proximal tubular reabsorption secondary to induction of tubular growth with associated increases in sodium/glucose cotransport. The increase in proximal reabsorption leads to a decrease in solute load to the macula densa, deactivation of the tubuloglomerular feedback, and increases in glomerular filtration rate. Because glomerular hyperfiltration currently is recognized as a risk factor for progression of kidney disease in diabetic patients, limiting proximal tubular reabsorption constitutes a potential target to reduce hyperfiltration. The recent introduction of sodium/glucose cotransporter 2 (SGLT2) inhibitors opens new therapeutic perspectives for this high-risk patient population. Experimental studies have shown that these new agents attenuate the progressive nature of diabetic nephropathy by blood glucose-dependent and -independent mechanisms. SGLT2 inhibition may prevent glomerular hyperfiltration independent of the effect of lowering blood glucose levels while limiting kidney growth, inflammation, and albuminuria through reductions in blood glucose levels. Clinical data for the potential role of the proximal tubule in the pathophysiology of diabetic nephropathy and the nephroprotective effects of SGLT2 inhibitors currently are limited compared to the more extensive experimental literature. We review the evidence supporting this working hypothesis by integrating the experimental findings with the available clinical data.

Intracholecystic papillary-tubular neoplasm of the gallbladder

The pathologic description for neoplastic polyps of the gallbladder (GB) was controversial. Although current WHO suggest adenoma and papillary neoplasm for precursor lesions, the distinction is not clear. In recent study for 123 GB cases, we found tumoral preinvasive neoplasms (≥ 1 cm) were analogous to their pancreatic and biliary counterparts. They show variable cellular lineages, a spectrum of dysplasia, and a mixture of papillary or tubular growth patterns, often with significant overlap, warranting their classification under one unified parallel category, intracholecystic papillary-tubular neoplasm (ICPN). We found that ICPN have similarity with intraductal papillary-mucinous neoplasm of pancreas (IPMN) and intraductal papillary neoplasm of bile duct (IPNB). ICPN of GB showed similar cell lineage and mucin core protein expression pattern with IPMN and IPNB. It is suspected that ICPN might be a GB counterpart with IPMN and IPNB. We think these polypoid precursor lesions of pancreatobiliary tract and GB may correspond to tumoral intraepithelial neoplasia, whereas the pancreatic intraepithelial neoplasia and biliary intraepithelial neoplasia correspond to the flat intraepithelial neoplasia. We also found there is a geographic difference of ICPN incidence between East and West. ICPN was more common in East whereas conventional flat dysplasia was more frequently found in West.

Tumor Necrosis on Magnetic Resonance Imaging Correlates With Aggressive Histology and Disease Progression in Clear Cell Renal Cell Carcinoma

ObjectiveThe study objective was to correlate the magnetic resonance imaging (MRI) features of clear cell renal cell carcinoma (ccRCC) with the histopathologic features and disease progression. MethodsInstitutional review board approval for this retrospective study was obtained; patient consent was not required. The initial staging MRI scans of 75 patients with histologically confirmed ccRCC were retrospectively reviewed. The imaging was assessed by 2 radiologists for the presence of tumor necrosis, cystic degeneration, intracellular fat, hemorrhage, retroperitoneal collaterals, and renal vein thrombosis. Quantitative analysis for the MRI presence of intracellular lipid within tumors was performed. MRI findings were correlated with histopathologic findings of clear cell percentage, alveolar and tubular growth pattern, and disease progression. Statistical associations were evaluated with nonparametric univariable analyses and multivariable logistic regression models. ResultsCorrelation between MRI and histopathologic features was performed in 75 patients, whereas follow-up data were available for progression analysis in 68 patients. The presence of tumor necrosis, retroperitoneal collaterals, and renal vein thrombosis on MRI was significantly associated with a low percentage of tumor cells with clear cytoplasm (P < .01) and metastatic disease at presentation or disease progression (P < .01). At multivariable analysis, necrosis remained the only feature statistically associated with disease progression (P = .03; adjusted odds ratio, 27.7; 95% confidence interval, 1.4-554.7 for reader 1 and P = .02; adjusted odds ratio, 29.3; 95% confidence interval, 1.7-520.8 for reader 2). ConclusionsNecrosis in ccRCC on MRI correlates with the histopathologic finding of lower percentage of tumor cells with clear cytoplasm and is a poor prognostic indicator irrespective of tumor size.

Characteristic tumor growth patterns as novel histomorphologic predictors for lymph node metastasis in papillary thyroid carcinoma

The aim of this study was to investigate the efficaciousness of histological tumor growth patterns in the prediction of lymph node metastasis (LNM) in papillary thyroid carcinoma (PTC). All combinations of infiltrative tumor border, lateral tubular growth, and intraglandular dissemination were assessed for their ability to predict LNM in 229 patients. In addition, we analyzed their predictive value within subgroups based on the tumor size and number of tumor nodules. Each tumor growth pattern was significantly associated with LNM, as 11 of the 12 combinations of these 3 patterns were found to be independently predictive of LNM (P < .05). Similar results were observed in both univariate and multivariate logistic regression analyses of PTCs, grouped according to the tumor size and number of tumor nodules. This study has shown that histological features suggestive of invasive tumor growth, including infiltrative tumor border and lateral tubular growth, may be used as independent predictive factors of LNM in PTC, and can improve treatment and follow-up strategies for PTC.

Bryoliths constructed by bryozoans in symbiotic associations with hermit crabs in a tropical heterozoan carbonate system, Golfe d’Arguin, Mauritania

The Golfe d’Arguin offshore of northern Mauritania hosts a rare modern analogue for heterozoan carbonate production in a tropical marine setting. Dominated by ocean upwelling and with additional fertilisation by iron-rich aeolian dust, this naturally eutrophic marine environment lacks typical photozoan communities. A highly productive, tropical cosmopolitan biota dominated by molluscs and suspension-feeders such as bryozoans and balanids characterises the carbonate-rich surface sediments. Overall biodiversity is relatively low and the species present are tolerant against the eutrophic and low-light conditions, the strong hydrodynamic regime governed by ocean upwelling, and the unstable, soft-bottom seafloor with few hard substrata. Here, we describe an ectosymbiosis between the hermit crab Pseudopagurus granulimanus (Miers, 1881) and monospecific assemblages of the encrusting cheilostome bryozoan Acanthodesia commensale (Kirkpatrick and Metzelaar, 1922) that cohabits vacant gastropod shells. Nucleating on an empty gastropod shell, the bryozoan colonies form multilamellar skeletal crusts that produce spherical encrustations and extend the living chamber of the hermit crab through helicospiral tubular growth. This non-obligate mutualistic symbiosis illustrates the adaptive capabilities and benefits from a close partnership in a complex marine environment, driven by trophic conditions, high water energies and instable substratum. Sectioned bryoliths show that between 49 and 97 % of the solid volume of the specimens consists of bryozoan skeleton.

Neuroendocrine Carcinoma of the Stomach

Neuroendocrine carcinoma (NEC) of the stomach has been recognized as a highly malignant tumor; however, because of its rarity, limited information is available regarding its clinicopathologic characteristics. Here, we investigated the morphologic and immunohistochemical features and prognosis of 51 cases of gastric NEC. Histologically, 40 lesions were large cell type, and 11 were small cell type. The large majority of the tumors exhibited a solid growth pattern (94%), with subsets of tumors showing trabecular (18%), scirrhous (10%), or tubular growth patterns (6%). Thirty-six cases (71%) had adenocarcinoma components and/or dysplasia. Among them, 26 cases (51%) were associated with intramucosal adenocarcinoma or dysplasia. Immunohistochemically, synaptophysin, chromogranin A, and CD56 were diffusely expressed in 48 (94%), 44 (86%), and 24 cases (47%), respectively. Two recently reported neuroendocrine markers, ASH1 and NKX2.2, were diffusely positive in 12 (24%) and 17 cases (33%), respectively. The diffuse or focal expression of TTF-1 was observed in 19 cases (37%). Among the 41 patients who underwent a curative resection, 16 patients (39%) developed radiologic recurrences, and the liver was the most frequent site of recurrence (11 patients, 27%). The 3- and 5-year overall survival rates were 57.8% and 44.7%, respectively. Regarding patient outcome, none of the histologic subclassifications, including small cell versus large cell types and the presence versus the absence of adenocarcinoma components and/or dysplasia, were significant. In a multivariate analysis, curative surgery was identified as the sole independent prognostic factor (P=0.03). Although gastric NECs exhibit significant morphologic diversity, their histologic subclassification is unlikely to be of immediate clinical relevance.

Missense mutation T485S alters NBCe1-A electrogenicity causing proximal renal tubular acidosis

Mutations in SLC4A4, the gene encoding the electrogenic Na(+)-HCO3(-) cotransporter NBCe1, cause severe proximal renal tubular acidosis (pRTA), growth retardation, decreased IQ, and eye and teeth abnormalities. Among the known NBCe1 mutations, the disease-causing mechanism of the T485S (NBCe1-A numbering) mutation is intriguing because the substituted amino acid, serine, is structurally and chemically similar to threonine. In this study, we performed intracellular pH and whole cell patch-clamp measurements to investigate the base transport and electrogenic properties of NBCe1-A-T485S in mammalian HEK 293 cells. Our results demonstrated that Ser substitution of Thr485 decreased base transport by ~50%, and importantly, converted NBCe1-A from an electrogenic to an electroneutral transporter. Aqueous accessibility analysis using sulfhydryl reactive reagents indicated that Thr485 likely resides in an NBCe1-A ion interaction site. This critical location is also supported by the finding that G486R (a pRTA causing mutation) alters the position of Thr485 in NBCe1-A thereby impairing its transport function. By using NO3(-) as a surrogate ion for CO3(2-), our result indicated that NBCe1-A mediates electrogenic Na(+)-CO3(2-) cotransport when functioning with a 1:2 charge transport stoichiometry. In contrast, electroneutral NBCe1-T485S is unable to transport NO3(-), compatible with the hypothesis that it mediates Na(+)-HCO3(-) cotransport. In patients, NBCe1-A-T485S is predicted to transport Na(+)-HCO3(-) in the reverse direction from blood into proximal tubule cells thereby impairing transepithelial HCO3(-) absorption, possibly representing a new pathogenic mechanism for generating human pRTA.

Polyphenols of Hibiscus sabdariffa improved diabetic nephropathy via regulating the pathogenic markers and kidney functions of type 2 diabetic rats

We recently demonstrated the chemical composition of Hibiscus sabdariffa polyphenol extracts (HPE), and its anti-insulin resistance property using a type 2 diabetic rat model. In the present study, we examined whether HPE prevents diabetic nephropathy, and its putative regulations of the pathogenic markers. HPE significantly inhibited albuminuria and the elevation of clearance of creatinine (CCr) caused by early diabetic nephropathy. Histological findings revealed that HPE inhibited fat deposition and advanced glycation end-products (AGE) expression in kidneys of type 2 diabetic rats. The increase of tubular connective tissue growth factors (CTGFs) and glomerular cluster of differentiation 31 (CD31) were also ameliorated by HPE. HPE reversed collagen accumulation, decreased angiotensin II type 1 receptor (AT-1) elevation, and improved oxidative stress. In conclusion, using the type 2 diabetic model, we have successfully shown that HPE not only has a benefit in reducing hyperglycaemia and hyperinsulinaemia, but can also prevent diabetic nephropathy. HPE has the potential to act as an adjuvant for diabetic therapy, and deserves further investigation.

Adenoid Cystic Carcinoma: Clinical and Molecular Features

The clinical features and common molecular alterations of adenoid cystic carcinoma (ACC) are reviewed in this paper. ACC is an uncommon neoplasm that most frequently arises in salivary glands and related tissue in the head and neck region. ACC has distinct histologic features, with cribriform and tubular growth patterns of basaloid cells displaying a predominantly myoepithelial cellular phenotype. This neoplasm also has uncommon clinical features of rare regional lymph node metastasis and a prolonged but relentlessly progressive clinical course. Clinical outcome in ACC is correlated to histologic grade, which is correlated to the degree of aneuploidy and genetic alterations present in the tumor genomes. Recent studies have identified that the majority of ACC contain alterations of the MYB gene, usually resulting in a fusion gene product with the NFIB gene by a t(6;9) translocation event. The molecular consequences of this alteration are incompletely understood, as are secondary molecular alterations that contribute to the neoplastic phenotype of ACC.

Regulation of G-protein signaling via Gnas is required to regulate proximal tubular growth in the Xenopus pronephros

In the kidney, proximal tubules are very important for the reabsorption of water, ions and organic solutes from the primary urine. They are composed of highly specialized epithelial cells that are characterized by an elaborate apical brush border to increase transport efficiency. Using the pronephric kidney of Xenopus laevis we discovered that the G-protein modulator cholera toxin resulted in a dramatic reduction of the proximal tubular size. This phenotype was accompanied by changes in the cytoarchitecture characterized by ectopic expression of the distal tubular marker 4A6 and an impairment of yolk platelet degradation. In addition, cholera toxin caused edema formation. However, this phenotype was not due to kidney defects, but rather due to impaired vasculature development. Based on experiments with antisense morpholino oligomers as well as pharmacological agonists and antagonists, we could show that the complex phenotype of cholera toxin in the pronephric kidney was caused by the hyperactivation of a single G-protein alpha subunit, Gnas. This—in turn—caused elevated cAMP levels, triggered a Rapgef4-dependent signaling cassette and perturbed exo- and endocytosis. This perturbation of the secretory pathway by Ctx was not only observed in Xenopus embryos. Also, in a human proximal tubular cell line, cholera toxin or a Rapgef4-specific agonist increased uptake and decreased secretion of FITC-labeled Albumin. Based on these data we propose that the Gnas/cAMP/Rapgef4 pathway regulates the signals inducing the proliferation of proximal tubules to acquire their final organ size.

20. A case report of adenoid cystic carcinoma (ACC) of the breast

Case summary A 60-year-old woman with a painful breast lump was diagnosed with adenoid cystic carcinoma (ACC). The tumour had solid cribriform and tubular growth patterns with true and pseudo-lumens. The epithelial component was positive for cyto-keratin 5/6 and the myoepithelial component was positive for cal-ponin. The oestrogen and progesterone stains were negative, and the Ki-67 was approximately 3–5%. Discussion ACC of the breast is a rare neoplasm accounting for 0.1% of all breast cancers. 1 It is of special interest because of its more favourable prognosis compared to ACC of the salivary glands and other types of breast cancers. It also presents difficulties with the differential diagnoses. The growth patterns seen in ACC may resemble collagenous sperulosis, cribriform carcinoma, small cell carcinoma, solid papillary carcinoma and even lymphoma. Immu-nohistochemistry to identify the dual epithelial-myoepithelial cell populations, and the typically negative estrogen and progesterone receptors help lead to the correct diagnosis of ACC. 2 Conclusion ACC of the breast is rare but has an excellent prognosis when it is accurately diagnosed.

Vesicle‐Mediated Growth of Tubular Branches and Centimeter‐Long Microtubes from a Single Molecule

The mechanism by which small molecules assemble into microscale tubular structures in aqueous solution remains poorly understood, particularly when the initial building blocks are non-amphiphilic molecules and no surfactant is used. It is here shown how a subnanometric molecule, namely p-aminothiophenol (p-ATP), prepared in normal water with a small amount of ethanol, spontaneously assembles into a new class of nanovesicle. Due to Brownian motion, these nanostructures rapidly grow into micrometric vesicles and start budding to yield macroscale tubular branches with a remarkable growth rate of ∼20 μm s⁻¹. A real-time visualization by optical microscopy reveals that tubular growth proceeds by vesicle walk and fusion on the apex (growth cone) and sides of the branches and ultimately leads to the generation of centimeter-long microtubes. This unprecedented growth mechanism is triggered by a pH-activated proton switch and maintained by hydrogen bonding. The vesicle fusion-mediated synthesis suggests that functional microtubes with biological properties can be efficiently prepared with a mixture of appropriate diaminophenyl blocks and the desired macromolecule. The reversibility, timescale, and very high yield (90%) of this synthetic approach make it a valuable model for the investigation of hierarchical and structural transition between organized assemblies with different size scales and morphologies.

Intraductal Tubular Neoplasms of the Bile Ducts

Although most tumors of the bile ducts are predominantly invasive, some have an exophytic pattern within the bile ducts; these intraductal papillary neoplasms usually have well-formed papillae at the microscopic level. In this study, however, we describe a novel type of intraductal neoplasm of the bile ducts with a predominantly tubular growth pattern and other distinctive features. Ten cases of biliary intraductal neoplasms with a predominantly tubular architecture were identified in the files of the Pathology Department at Memorial Sloan-Kettering Cancer Center from 1983 to 2006. For each of these cases we studied the clinical presentation, histologic and immunohistochemical features (9 cases only), and the clinical follow-up of the patients. Three male and 7 female patients (38 to 78 y) presented with obstructive jaundice or abdominal pain. Eight of the patients underwent a partial hepatectomy; 2 underwent a laparoscopic bile duct excision, followed by a pancreatoduodenectomy in one of them. The tumors range in size from 0.6 to 8.0 cm. The intraductal portions of the tumors (8 intrahepatic, 1 extrahepatic hilar, 1 common bile duct) were densely cellular and composed of back-to-back tubular glands and solid sheets with minimal papillary architecture. The cells were cuboidal to columnar with mild to moderate cytologic atypia. Foci of necrosis were present in the intraductal component in 6 cases. An extraductal invasive carcinoma component was present in 7 cases, composing <25% of the tumor in 4 cases, and >75% in 1 case. It was observed by immunohistochemical analysis that the tumor cells expressed CK19, CA19-9, MUC1, and MUC6 in most cases and that SMAD4 expression was retained. MUC2, MUC5AC, HepPar1, synaptophysin, chromogranin, p53, and CA125 were negative in all cases and most were negative for CEA-M and B72.3. Four patients were free of tumor recurrence after 7 to 85 months (average, 27 mo). Four patients with an invasive carcinoma component suffered metastases, 1 after local intraductal recurrence. However, the occurrence of metastasis in 3 of these patients was quite late (average, 52 mo). Intraductal tubular neoplasm of the bile ducts is a biliary intraductal neoplasm with a distinctive histologic pattern resembling the recently described intraductal tubulopapillary neoplasm of the pancreas. Immunohistochemical features are similar to those of other pancreatobiliary-type carcinomas. However, this tumor may be hard to recognize as intraductal because of its complex architecture. When the tumor is entirely intraductal, the outcome appears to be favorable, but metastases can occur when invasive carcinoma is present, even after many years.

Blunted fetal growth by tenofovir in late pregnancy

Tenofovir disoproxil fumarate (TDF) is recommended for pregnant women coinfected with HIV and hepatitis B virus to prevent mother-to-infant transmission of both viruses [1]. However, the safety of TDF in pregnancy is still controversial, especially with regard to its effects on fetal growth and bone mineralization. Here, we describe a 32-year-old HIV-1-infected Asian pregnant woman, who showed blunted fetal growth during TDF treatment. She had been treated during the first 33 weeks of pregnancy with abacavir, lopinavir/ritonavir and raltegravir based on multiple viral mutations. As plasma concentrations of raltegravir were persistently low, treatment was switched to TDF at 35 weeks of gestation, until delivery at 38 weeks. The fetal growth curves of biparietal diameters and femur length were within the normal ranges before starting TDF; however, the growth of both parameters was significantly blunted after starting TDF (Fig. 1). Furthermore, tubular reabsorption rates for phosphate, urinary β2-microglobulin and alkaline phosphatase were 88%, 2776 μg/L and 435 U/L, respectively, during the TDF-treatment period, compared with 97%, 140 μg/L and 182 U/L, respectively, during the non-TDF-treatment period. Plasma TDF concentration in the mother was 3536 ng/mL at 4 h after dosing and 776 ng/mL in cord blood. The infant was delivered by cesarean section without HIV-1 infection, and weighed 2218 g (−2 SDs for Japanese infants), with a height of 45.0 cm (−1.5 SD), and a head circumference of 29.5 cm (−2 SD). Furthermore, moderate tubular dysfunction was observed at birth (serum calcium: 7.4 mg/dL, serum phosphate: 4.6 mg/dL, alkaline phosphatase: 560 U/L, urine β2-microglobulin: 1780 μg/L), together with a high plasma TDF concentration [102 ng/mL at 24 h after delivery (28 h after mother's dosing)]. Although the body length was persistently short throughout the first 3 months (less than −2 SD), the hand X-ray at 1 and 3 months showed no signs of osteopenia or rickets.Fig. 1: Serial changes in fetal biparietal diameters, femur length and proximal tubular function during pregnancy.Between 20 and 33 weeks of gestation [non-tenofovir disoproxil fumarate (TDF)-treatment period], the growth curves of biparietal distance, femur length and proximal tubular function were within the normal ranges. However, the increases in biparietal distance and femur length were blunted after 35 weeks of gestation (TDF-treatment period), with a worsening of all markers of proximal tubular function. U-BMG, urine β2-microglobulin; %TRP, tubular reabsorption rate for phosphates; ALP, serum alkaline phosphatase.The present case raises two concerns with regard to the safety of TDF in pregnancy. TDF can reduce bone mineral density [2]. Van Rompay et al.[3] reported that treatment of infant macaque with high-dose TDF caused proximal tubular dysfunction, growth retardation and osteomalacia. Our findings suggest that administration of TDF during pregnancy caused fetal disordered bone growth through modest proximal tubular dysfunction. However, it is not clear whether maternal TDF-associated tubular dysfunction will cause future bone growth retardation in infants. A large cohort study reported that significantly shorter height was observed at age 1 year in TDF-exposed infants [4], which is generally considered as one of the symptoms of mild rickets. However, in our case, despite the persistently shorter height of the infant (less than −2 SD) throughout the first 3 months of life, hand X-ray at 3 months showed no findings of osteopenia or rickets. Second, plasma TDF concentrations in our case were 10-fold higher than the previously reported values [5], probably reflecting the mother's small body size (weight: 47 kg), and consequently higher placental transfer of TDF to the fetus. Asian pregnant women, who have smaller body size, may impose a more severe effect on fetal growth retardation than that reported previously. The effect of TDF in pregnancy and its impact on fetal growth needs to be evaluated in more detail. Acknowledgements Conflicts of interest There are no conflicts of interest.

Intracholecystic Papillary-Tubular Neoplasms (ICPN) of the Gallbladder (Neoplastic Polyps, Adenomas, and Papillary Neoplasms That Are ≥1.0 cm)

The literature on the clinicopathologic characteristics of tumoral intraepithelial neoplasms (neoplastic polyps) of the gallbladder (GB) is fairly limited, due in part to the variability in definition and terminology. Most reported adenomas (pyloric gland type and others) were microscopic and thus regarded as clinically inconsequential, whereas papillary in situ carcinomas have been largely considered a type of invasive adenocarcinoma under the heading of "papillary adenocarcinomas." In this study, 123 GB cases that have a well-defined exophytic preinvasive neoplasm measuring ≥1 cm were analyzed. The patients were predominantly female (F/M=2:1) with a mean age of 61 y and a median tumor size of 2.2 cm. Half of the patients presented with pain, and in the other half the neoplasm was detected incidentally. Other neoplasms, most being gastrointestinal tract malignancies, were present in 22% of cases. Gallstones were identified in only 20% of cases. Radiologically, almost half were diagnosed as "cancer," roughly half with polypoid tumor, and in 10% the lesion was missed. Pathologic findings: (1) The predominant configuration was papillary in 43%, tubulopapillary in 31%, tubular in 26%. (2) Each case was assigned a final lineage type on the basis of the predominant pattern (>75% of the lesion) on morphology, and supported with specific immunohistochemical cell lineage markers. The predominant cell lineage could be identified as biliary in 50% (66% of which were MUC1), gastric foveolar in 16% (all were MUC5AC), gastric pyloric in 20% (92% MUC6), intestinal in 8% (100% CK20; 75% CDX2; 50%, MUC2), and oncocytic in 6% (17% HepPar and 17% MUC6); however, 90% of cases had some amount of secondary or unclassifiable pattern and hybrid immunophenotypes. (3) Of the cases that would have qualified as "pyloric gland adenoma," 21/24 (88%) had at least focal high-grade dysplasia and 18% had associated invasive carcinoma. Conversely, 8 of 47 "papillary adenocarcinoma"-type cases displayed some foci of low-grade dysplasia, and 15/47 (32%) had no identifiable invasion. (4) Overall, 55% of the cases had an associated invasive carcinoma (pancreatobiliary type, 58; others, 10). Factors associated significantly with invasion were the extent of high-grade dysplasia, cell type (biliary or foveolar), and papilla formation. Among systematically analyzed invasive carcinomas, tumoral intraepithelial neoplasia was detected in 6.4% (39/606). (5) The 3-year actuarial survival was 90% for cases without invasion and 60% for those associated with invasion. In contrast, those associated with invasion had a far better clinical outcome compared with pancreatobiliary-type GB carcinomas (3-yr survival, 27%), and this survival advantage persisted even with stage-matched comparison. Death occurred in long-term follow-up even in a few noninvasive cases (4/55; median 73.5 mo) emphasizing the importance of long-term follow-up. In conclusion, tumoral preinvasive neoplasms (≥1 cm) in the GB are analogous to their pancreatic and biliary counterparts (biliary intraductal papillary neoplasms, pancreatic intraductal papillary mucinous neoplasms, and intraductal tubulopapillary neoplasms). They show variable cellular lineages, a spectrum of dysplasia, and a mixture of papillary or tubular growth patterns, often with significant overlap, warranting their classification under 1 unified parallel category, intracholecystic papillary-tubular neoplasm. Intracholecystic papillary-tubular neoplasms are relatively indolent neoplasia with significantly better prognosis compared with pancreatobiliary-type GB carcinomas. In contrast, even seemingly innocuous examples such as those referred to as "pyloric gland adenomas" can progress to carcinoma and be associated with invasion and fatal outcome.