VATS lobectomy and thoracotomy demonstrated similar 5-year survivals. However, VATS lobectomy was associated with fewer complications and shorter length of hospital stay.

DEAD/H-box NTPases remodel the spliceosome at multiple steps during the pre-mRNA splicing cycle. The RNA-dependent NTPase Prp43 catalyzes dissociation of excised lariat-intron from the spliceosome, but it is unclear how Prp43 couples the energy of ATP hydrolysis to intron release. Here, we report that activation of Prp43's inherently feeble helicase activity by the splicing factor Ntr1 is required for lariat-intron release. Lethal Prp43 mutants T384A and T384V, which are active for ATP hydrolysis and fail to dissociate lariat-intron from spliceosomes, are refractory to stimulation of RNA unwinding by Ntr1. An N-terminal 120-amino-acid segment of Ntr1 suffices for binding to Prp43 and for stimulating its helicase activity. We identify missense mutations in Prp43 and Ntr1 that disrupt protein-protein interaction and impair Ntr1 enhancement of Prp43 RNA unwinding. Our results demonstrate for the first time that regulating the motor activity of a DEAH-box protein by an accessory factor is critical for mRNA splicing.[Keywords: Pre-mRNA splicing; DEAH-box helicase; Prp43; Ntr1; spliceosome] Supplemental material is available at http:/www.genesdev.org. Nuclear pre-mRNA splicing proceeds via two successive transesterification reactions (Burge et al. 1999). In the first step, the 2Ј-OH of the branch site adenosine within the intron attacks the phosphodiester at the 5Ј exonintron boundary to form a lariat-intermediate. In the second step, the 3Ј-OH of the 5Ј exon attacks the phosphodiester at the intron-3Ј exon junction to form mature mRNA and lariat-intron. Pre-mRNA splicing requires five snRNAs and >80 proteins (Will and Lührmann 2006). The small nuclear RNAs (snRNAs), packaged as snRNPs, assemble together with non-snRNP proteins onto the precursor RNA to form the spliceosome. The snRNPs are involved in identifying the splice junctions and positioning the reactive nucleotides for catalysis (Valadkhan 2005). ATP-dependent remodeling of RNA-RNA and RNA-protein interactions is essential for faithful spliceosome assembly, for the catalytic activation of the splice sites, and for spliceosome disassembly (Staley and Guthrie 1998).The remodeling events in the spliceosome are catalyzed by DExD/H NTPases that act at discrete stages of the splicing pathway (Staley and Guthrie 1998). Splicing factors Prp2, Prp16, Prp22, and Prp43 are members of the DEAH family of RNA-dependent NTPases (Burgess et al. 1990;Chen and Lin 1990;Company et al. 1991;Arenas and Abelson 1997). They are composed of a central NTPase/helicase domain, characteristic of all DExH proteins, plus an ∼300-amino-acid C-terminal domain unique to the Prp2/Prp16/Prp22/Prp43 clade (Tanner and Linder 2001;Silverman et al. 2003). The N-terminal segments are distinctive in each DEAH-box splicing factor. Understanding how the DEAH proteins carry out their specific functions during the splicing cycle requires knowledge about how they are recruited to the splicing complex, what their biochemical activities are, and whether they are regulated.Prp43 catalyzes the final step of ...

Yeast and plant tRNA splicing entails discrete healing and sealing steps catalyzed by a tRNA ligase that converts the 29,39 cyclic phosphate and 59-OH termini of the broken tRNA exons to 39-OH/29-PO 4 and 59-PO 4 ends, respectively, then joins the ends to yield a 29-PO 4 , 39-59 phosphodiester splice junction. The junction 29-PO 4 is removed by a tRNA phosphotransferase, Tpt1. Animal cells have two potential tRNA repair pathways: a yeast-like system plus a distinctive mechanism, also present in archaea, in which the 29,39 cyclic phosphate and 59-OH termini are ligated directly. Here we report that a mammalian 29,39 cyclic nucleotide phosphodiesterase (CNP) can perform the essential 39 end-healing steps of tRNA splicing in yeast and thereby complement growth of strains bearing lethal or temperature-sensitive mutations in the tRNA ligase 39 end-healing domain. Although this is the first evidence of an RNA processing function in vivo for the mammalian CNP protein, it seems unlikely that the yeast-like pathway is responsible for animal tRNA splicing, insofar as neither CNP nor Tpt1 is essential in mice.

Hypertension causes significant morbidity and mortality worldwide, owing to its deleterious effects on the cardiovascular and renal systems. Primary hyperaldosteronism (PA) is the most common cause of reversible hypertension, affecting 5%-18% of adults with hypertension. PA is estimated to result from bilateral adrenal hyperplasia in two-thirds of patients, and from unilateral aldosterone-secreting adenoma in approximately one-third. Suspected cases are initially screened by measurement of the plasma aldosterone-renin-ratio, and may be confirmed by additional noninvasive tests. Localization of aldostosterone hypersecretion is then determined by computed tomography imaging, and in selective cases with adrenal vein sampling. Solitary adenomas are managed by laparoscopic or robotic resection, while bilateral hyperplasia is treated with mineralocorticoid antagonists. Biochemical cure following adrenalectomy occurs in 99% of patients, and hemodynamic improvement is seen in over 90%, prompting a reduction in quantity of anti-hypertensive medications in most patients. End-organ damage secondary to hypertension and excess aldosterone is significantly improved by both surgical and medical treatment, as manifested by decreased left ventricular hypertrophy, arterial stiffness, and proteinuria, highlighting the importance of proper diagnosis and treatment of primary hyperaldosteronism. Although numerous independent predictors of resolution of hypertension after adrenalectomy for unilateral adenomas have been described, the Aldosteronoma Resolution Score is a validated multifactorial model convenient for use in daily clinical practice.

After the second transesterification step of pre-mRNA splicing, the Prp22 helicase catalyzes release of spliced mRNA by disrupting contacts in the spliceosome that likely involve Prp8. Mutations at Arg1753 in Prp8, which suppress helicase-defective prp22 mutants, elicit temperature-sensitive growth phenotypes, indicating that interactions in the spliceosome involving Prp8-R1753 might be broken prematurely at 37°C. Here we report that mutations in loop I of the U5 snRNA or in Prp18 can suppress the temperature-sensitive prp8-R1753 mutants. The same gain-of-function PRP18 alleles can also alleviate the growth phenotypes of multiple slu7-ts mutants, indicating a functional link between Prp8 and the second step splicing factors Prp18 and Slu7. These findings, together with the demonstration that changes at Arg1753 in Prp8 impair step 2 of pre-mRNA splicing in vitro, are consistent with a model in which (1) Arg1753 plays a role in stabilizing U5/exon interactions prior to exon joining and (2) these contacts persist until they are broken by the helicase Prp22.

No abstract

Prostate-specific membrane antigen (PSMA), a type II transmembrane glycoprotein receptor, is highly expressed in prostate cancer and in the tumor neovasculature of colon, breast, and adrenocortical tumors. Here, we analyzed PSMA expression in the neovasculature of various thyroid cancer subtypes and assessed whether PSMA expression is correlated with aggressive behavior. From a prospectively maintained database, we evaluated 91 samples from 68 patients, including 37 primary differentiated thyroid cancers (DTCs) [11 classic papillary (cPTC), 9 follicular-variant (FvPTC), 11 follicular (FTC), 6 radioactive iodine-refractory (RAIR)], 5 anaplastic (ATC) carcinomas, 9 distant and 12 lymph node metastases, 21 benign thyroid nodules, and 7 normal thyroid specimens. Formalin-fixed paraffin-embedded tissue blocks were immunostained for vascular endothelial marker CD31 and PSMA with proper controls. PSMA expression was not detected in normal thyroid tissue. DTC tumors demonstrated a significantly higher PSMA expression, in regard to both intensity and percentage of vessels stained, than benign tumors (p < 0.001). Among the histologic subtypes, cPTC, FTC, and RAIR carcinomas demonstrated the highest percent of moderate to strong PSMA staining. PSMA expression was seen more frequently in specimens from distant metastases (100%) compared with specimens from only lymph node metastases (67%). PSMA is significantly overexpressed in the neovasculature of DTCs compared with normal and benign thyroid nodules specifically with increased expression in RAIR carcinomas and distant metastases. PSMA should be further explored as a novel therapeutic target for metastatic and RAIR carcinomas.

The conversion rate during laparoscopic appendectomy has not changed significantly over the past seven years and remains ~4%. Independent pre-operative predictors of conversion are advanced age, ASA score>2 points, attending surgeon inexperience, and extensive inflammation observed on pre-operative CT scan. Proceeding directly with open appendectomy under these circumstances may reduce operative time, expense, and morbidity.