Identification of a novel aquaporin, AQP12, expressed in pancreatic acinar cells

Members of the aquaporin (AQP) water channel family are widely distributed in various tissues and contribute to the water permeability of epithelial and endothelial cells. Currently 11 members of the AQP family (AQP0-10) have been reported in mammals. Here we report the identification of AQP12, which we found by performing a BLAST program search. Northern blot analysis revealed that AQP12 was specifically expressed in the pancreas. Further analysis by in situ hybridization and RT-PCR studies showed that AQP12 was selectively localized in the acinar cells of the pancreas. To analyze the cellular localization and function of AQP12, we expressed AQP12 in Xenopus oocytes and cultured mammalian cells. Immunocytochemistry revealed that AQP12 was not targeted to the plasma membrane. The selective localization of AQP12 in pancreatic acinar cells and possibly in the intracellular organelles suggests a role of AQP12 in digestive enzyme secretion such as maturation and exocytosis of secretory granules.     

Cytologic diagnosis of small cell anaplastic hepatoblastoma: a case report

BACKGROUND: Small cell anaplastic hepatoblastoma (HB) is the least common subtype of HB. There are few articles in the literature describing the cytologic characteristics of this rare subtype. CASE: A 5-year-old girl present with a progressively enlarging abdominal mass. Ultrasound examination revealed the mass to be arising within the right lobe of the liver. Fine needle aspiration (FNA) of the mass revealed primitive cells with a high nuclear/cytoplasmic ratio and hyperchromatic, ovoid nuclei in poorly cohesive clusters as well as dispersed singly. These cells closely resembled those of small round cell tumors of childhood. CONCLUSION: The cytologic differential diagnosis of undifferentiated HB must include small round cell tumors of childhood. With knowledge of the typical cytomorphologic appearance of HB in association with clinical and radiologic information, one can offer a reliable preoperative diagnosis on FNA.     

Impedance of goat lens as a function of frequency at DC voltages 0, 50, 100, 200 mV

Impedance characteristics of lens tissue has been studied using the AC impedance system (EG&G PARC, model 318) at different low voltage excitations using a Cole-Cole Plot. The extracellular resistance (Re), intracellular resistance (Ri), depressed angle (theta), total impedance (/Z/), and phase angle (phi) of the tissue were measured. The impedance locus between the real part (Z') and imaginary part (Z') of the complex impedance of lens was examined at discrete frequencies ranging from 10 mHz to 10 Hz. A decrease in extra-cellular resistance (Re) and increase in distribution of the factor (alpha) of 56.8 KOmega, 48.1 KOmega, 32.8 KOmega, 13.4 KOmega, and 0.40, 0.43, 0.46, 0.53 were found at 0 mV, 50 mV, 100 mV, and 200 mV, respectively. The total impedance (/Z/) and phase angle (phi) were also evaluated and the observed frequency dependent for the frequency range was tested as a function of excitation voltage. An attempt has been made to explain the effect of voltage stress on lens impedance.     

Broad-spectrum Blast Resistance Gene Pi-k h Cloned from Rice Line Tetep Designated as Pi54

Blast disease caused by Magnaporthe oryzae is one of the important biotic stresses of rice. So far more than 85 blast resistance genes have been identified of these more than 14 have already been cloned. A broad spectrum rice blast resistance gene Pi-k ^h was cloned from the rice line Tetep. The gene was named Pi-k ^h based on the earlier reports on its genetic analysis in various rice lines. However, with the advances in molecular genetics and genomics of rice, the Pik locus has now been mapped more precisely. Since there are two reports on the mapping of Pi-k ^h gene from different rice lines, there is some confusion in the naming of this gene. In this report the name of Pi-k ^h gene cloned from the rice line Tetep has been designated as per the standard guidelines of Committee on Gene Symbolization, Nomenclature and Linkage (CGSNL) and its physical location on rice chromosome 11, which is ～2.5 Mbp away from the Pik locus mapped recently. Hence Pi-k ^h gene cloned from Tetep is now designated as Pi54.     

Direct rhizogenesis and establishment of fast growing normal root organ culture of Withania somnifera Dunal

Direct rooting from leaf explants of Withania somnifera was achieved on half strength Murashige and Skoog’s medium supplemented with 15 g l⁻¹ sucrose, and different concentrations of growth regulators. Basal medium supplemented with 2.85 μM indoleacetic acid and 9.85 μM indolebutyric acid achieved maximum number of roots with 100% response. The roots were cultured on MS liquid medium for the establishment of root-organ culture with the same plant growth regulators and incubated on an orbital shaker at 80 rpm at 25 ± 2 °C. A root biomass of 6.15 ± 0.17 g was obtained after 5 weeks. When 1 g roots were inoculated to 2.5 l bubble column reactor, 47 g roots were obtained after 6 weeks. The concentration of alkaloids was increased as compared to field grown roots. The maximum concentration of withanolides (10 mg g⁻¹ dry weight) was obtained in the bioreactor.     

Zebra fish Dnmt1 and Suv39h1 regulate organ-specific terminal differentiation during development

DNA methylation and histone methylation are two key epigenetic modifications that help govern heterochromatin dynamics. The roles for these chromatin-modifying activities in directing tissue-specific development remain largely unknown. To address this issue, we examined the roles of DNA methyltransferase 1 (Dnmt1) and the H3K9 histone methyltransferase Suv39h1 in zebra fish development. Knockdown of Dnmt1 in zebra fish embryos caused defects in terminal differentiation of the intestine, exocrine pancreas, and retina. Interestingly, not all tissues required Dnmt1, as differentiation of the liver and endocrine pancreas appeared normal. Proper differentiation depended on Dnmt1 catalytic activity, as Dnmt1 morphants could be rescued by active zebra fish or human DNMT1 but not by catalytically inactive derivatives. Dnmt1 morphants exhibited dramatic reductions of both genomic cytosine methylation and genome-wide H3K9 trimethyl levels, leading us to investigate the overlap of in vivo functions of Dnmt1 and Suv39h1. Embryos lacking Suv39h1 had organ-specific terminal differentiation defects that produced largely phenocopies of Dnmt1 morphants but retained wild-type levels of DNA methylation. Remarkably, suv39h1 overexpression rescued markers of terminal differentiation in Dnmt1 morphants. Our results suggest that Dnmt1 activity helps direct histone methylation by Suv39h1 and that, together, Dnmt1 and Suv39h1 help guide the terminal differentiation of particular tissues.     

Phosphate Metabolism in the Cyanobacterium Anabaena doliolum Under Salt Stress

In the present study, we have investigated the effects of NaCl concentrations on the growth and phosphate metabolism of an Anabaena doliolum strain isolated from a paddy field, in order to determine the possible effects of salinization. Growth rate, chlorophyll content, and protein content decreased with increasing salt concentration in the growth medium, while carbohydrate concentration increased. Phosphate content and phosphate uptake rate decreased. There was an increase in total alkaline phosphatase activity, with an approximately 7-fold increase in extracellular activity compensating for an approximately 3-fold decrease in cell-bound activity. NaCl effects on protein and chlorophyll concentrations were greater in P-deficient medium, while presence or absence of P in the medium had little effect on cellular carbohydrate concentrations. It is concluded that growth in high salt likely leads to reduced phosphate uptake in A. doliolum.