Ureteroscopy and lasertripsy for lower pole stones <2 cm, in situ vs displacement? A systematic review and meta-analysis.

Objective: To investigate the outcomes of ureteroscopy and lasertripsy in lower pole renal stones <2 cm when treated in situ compared to displacement to the upper pole.

Patients And Methods: Using the Medical Literature Analysis and Retrieval System Online (MEDLINE)/PubMed, the Excerpta Medica dataBASE (EMBASE), Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Cochrane Library, and Clinicaltrials.gov we identified adult population, English language, studies published until March 2023 comparing surgical outcomes and stone-free rates (SFRs) in relation to lower pole stones <2 cm managed in situ vs those displaced (International Prospective Register of Systematic Reviews [PROSPERO] identifier: CRD42023432750).

Effect of infundibulopelvic angle on outcomes of ureteroscopy: a systematic review and meta-analysis.

Purpose: The infundibulo-pelvic angle (IPA) is reportedly a predictor of successful ureteroscopy for lower pole renal stones, however there is uncertainty at which IPA success is likely. We therefore aimed to perform a meta-analysis and determine at which the angle of likely success and failure.

Methods: We performed a systematic review and meta-analysis as per Cochrane guidelines in accordance to the PRISMA statement.

A scoring system for predicting malignancy in intraductal papillary mucinous neoplasms of the pancreas: a multicenter EUROPEAN validation.

Purpose: A preoperative estimate of the risk of malignancy for intraductal papillary mucinous neoplasms (IPMN) is important. The present study carries out an external validation of the Shin score in a European multicenter cohort.

Methods: An observational multicenter European study from 2010 to 2015.

Acute Kidney Injury After Esophageal Cancer Surgery: Incidence, Risk Factors, and Impact on Oncologic Outcomes.

Objective: To determine the incidence, risk factors, and consequences of AKI in patients undergoing surgery for esophageal cancer.

Summary Of Background Data: Esophageal cancer surgery is an exemplar of major operative trauma, with well-defined risks of respiratory, cardiac, anastomotic, and septic complications. However, there is a paucity of literature regarding AKI.

Design and 22-step synthesis of highly potent D-ring modified and linker-equipped analogs of spongistatin 1.

Spongistatin 1 is among the most potent anti-proliferative agents ever discovered rendering it an attractive candidate for development as a payload for antibody-drug conjugates and other targeted delivery approaches. Unfortunately, it is unavailable from natural sources and its size and complex stereostructure render chemical synthesis highly time- and resource-intensive. As a result, the design and synthesis of more acid-stable and linker functional group-equipped analogs that retain the low picomolar potency of the parent natural product requires more efficient and step-economical synthetic access.

Direct, Mild, and General n-BuNBr-Catalyzed Aldehyde Allylsilylation with Allyl Chlorides.

A direct, mild, and general method for the enantioselective allylsilylation of aldehydes with allyl chlorides is reported. The reactions are effectively catalyzed by 5 mol % of n-BuNBr, and this rate acceleration allows the use of complex allyl donors in fragment-coupling reactions and of electron-deficient allyl donors. The results are (1) significant progress toward a "universal" asymmetric aldehyde allylation reaction that can reliably and highly stereoselectively couple any allyl chloride_aldehyde combination and (2) the discovery of a novel mode of nucleophilic catalysis for aldehyde allylsilylation reactions.

Synthesis and Evaluation of a Linkable Functional Group-Equipped Analogue of the Epothilones.

An approach to the validation of a linker strategy for the epothilone family of microtubule-stabilizing agents is reported. An analogue of epothilone B in which the C(6) methyl group has been replaced with a 4-azidobutyl group has been prepared by total chemical synthesis, and amides derived from the azido group have been shown to retain the activity of the parent compound. These results set the stage for an evaluation of the potential of the epothilones to serve as the drug component of antibody-drug conjugates and other selective tumor cell-targeting conjugates.

Silane and Germane Molecular Electronics.

This Account provides an overview of our recent efforts to uncover the fundamental charge transport properties of Si-Si and Ge-Ge single bonds and introduce useful functions into group 14 molecular wires. We utilize the tools of chemical synthesis and a scanning tunneling microscopy-based break-junction technique to study the mechanism of charge transport in these molecular systems. We evaluated the fundamental ability of silicon, germanium, and carbon molecular wires to transport charge by comparing conductances within families of well-defined structures, the members of which differ only in the number of Si (or Ge or C) atoms in the wire.

Evolution of an Efficient and Scalable Nine-Step (Longest Linear Sequence) Synthesis of Zincophorin Methyl Ester.

Because of both their synthetically challenging and stereochemically complex structures and their wide range of often clinically relevant biological activities, nonaromatic polyketide natural products have for decades attracted an enormous amount of attention from synthetic chemists and played an important role in the development of modern asymmetric synthesis. Often, such compounds are not available in quantity from natural sources, rendering analogue synthesis and drug development efforts extremely resource-intensive and time-consuming. In this arena, the quest for ever more step-economical and efficient methods and strategies, useful and important goals in their own right, takes on added importance, and the most useful syntheses will combine high levels of step-economy with efficiency and scalability.

Mechanism for Si-Si Bond Rupture in Single Molecule Junctions.

The stability of chemical bonds can be studied experimentally by rupturing single molecule junctions under applied voltage. Here, we compare voltage-induced bond rupture in two Si-Si backbones: one has no alternate conductive pathway whereas the other contains an additional naphthyl pathway in parallel to the Si-Si bond. We show that in contrast to the first system, the second can conduct through the naphthyl group when the Si-Si bond is ruptured using an applied voltage.

Influence of Different Levels of Lipoic Acid Synthase Gene Expression on Diabetic Nephropathy.

Oxidative stress is implicated in the pathogenesis of diabetic nephropathy (DN) but outcomes of many clinical trials are controversial. To define the role of antioxidants in kidney protection during the development of diabetic nephropathy, we have generated a novel genetic antioxidant mouse model with over- or under-expression of lipoic acid synthase gene (Lias). These models have been mated with Ins2Akita/+ mice, a type I diabetic mouse model.

High-Conductance Pathways in Ring-Strained Disilanes by Way of Direct σ-Si-Si to Au Coordination.

A highly conducting electronic contact between a strained disilane and Au is demonstrated through scanning tunneling microscope-based single-molecule measurements. Conformationally locked cis diastereomers of bis(sulfide)-anchor-equipped 1,2-disilaacenaphthenes readily form high-conducting junctions in which the two sulfide anchors bind in a bipodal fashion to one gold electrode, providing enough stability for a stable electrical contact between the Si-Si σ bond and the other electrode.

Tuberous Sclerosis and Bilateral Renal Angiomyolipomas: A Case Report and Literature Review of Emerging Treatment Strategies.

Tuberous sclerosis complex is a rare multisystemic genetic disorder associated with the development of benign hamartomas. Angiomyolipomas are one such characteristic finding that may be seen in 55-80% of tuberous sclerosis complex patients. While being normally asymptomatic, they can also cause significant morbidity and mortality.

A Highly Stereoselective, Efficient, and Scalable Synthesis of the C(1)-C(9) Fragment of the Epothilones.

A second-generation synthesis of the C(1)-C(9) fragment of the epothilones is reported. The key tandem intramolecular silylformylation/crotylsilylation/"aprotic" Tamao oxidation sequence has been redeveloped as a stepwise intermolecular variant, allowing excellent levels of diastereoselectivity in the crotylation step and proceeds in 50% overall yield on gram scale. An improved synthesis of the homopropargyl alcohol starting material is also described, which proceeds in four steps and >99% ee from inexpensive starting materials and is amenable to multigram scales.

A "methyl extension" strategy for polyketide natural product linker site validation and its application to dictyostatin.

An approach to the validation of linker strategies for polyketide natural products with few or no obvious handles for linker attachment, and its application to dictyostatin, are described. Analogues in which the C(6)- and C(12)-methyl groups were replaced by 4-azidobutyl groups were prepared and shown to retain the low nanomolar potency of dictyostatin. Further, conjugation of the C(6) analogue with a cyclooctyne resulted in only minor attenuations in potency.

Effects of MS-153 on chronic ethanol consumption and GLT1 modulation of glutamate levels in male alcohol-preferring rats.

We have recently shown that upregulation of glutamate transporter 1 (GLT1) in the brain is associated in part with reduction in ethanol intake in alcohol-preferring (P) male rats. In this study, we investigated the effects of a synthetic compound, (R)-(-)-5-methyl-1-nicotinoyl-2-pyrazoline (MS-153), known to activate GLT1 on ethanol consumption as well as GLT1 expression and certain signaling pathways in P rats. P rats were given 24-h concurrent access to 15 and 30% ethanol, water and food for 5 weeks.

Acute tubular necrosis (ATN) presenting with an unusually prolonged period of marked polyuria heralded by an abrupt oliguric phase.

A 50-year-old African-American man presented with acute tubular necrosis (ATN) secondary to hypotension from non-typhoid Salmonella gastroenteritis and bacteraemia. The oliguric phase lasted only 24 h followed by prolonged polyuria for 20 days, with urine output in excess of 16 L/day at maximum. As indexed in PubMed this is only the second published case of this nature since 1974, in which an abrupt oliguric phase of 24 h or less heralded prolonged polyuria in ATN.

Design, development, mechanistic elucidation, and rational optimization of a tandem Ireland Claisen/Cope rearrangement reaction for rapid access to the (iso)cyclocitrinol core.

An approach to the synthesis of the (iso)cyclocitrinol core structure is described. The key step is a tandem Ireland Claisen/Cope rearrangement sequence, wherein the Ireland Claisen rearrangement effects ring contraction to a strained 10-membered ring, and that strain in turn drives the Cope rearrangement under unusually mild thermal conditions. A major side product was identified as resulting from an unexpected and remarkably facile [1,3]-sigmatropic rearrangement, and a tactic to disfavor the [1,3] pathway and increase the efficiency of the tandem reaction was rationally devised.

Beyond the Roche ester: a new approach to polypropionate stereotriad synthesis.

An efficient, step-economical, and scalable approach to the synthesis of polypropionate stereotriads has been developed. Either 2-butyne or propyne is subjected to rhodium-catalyzed silylformylation and in situ crotylation of the resulting aldehydes. Tamao oxidation under either "standard" conditions or "aprotic" conditions then delivers the completed stereotriads in a three-step, two-pot sequence.

Silicon ring strain creates high-conductance pathways in single-molecule circuits.

Here we demonstrate for the first time that strained silanes couple directly to gold electrodes in break-junction conductance measurements. We find that strained silicon molecular wires terminated by alkyl sulfide aurophiles behave effectively as single-molecule parallel circuits with competing sulfur-to-sulfur (low G) and sulfur-to-silacycle (high G) pathways. We can switch off the high conducting sulfur-to-silacycle pathway by altering the environment of the electrode surface to disable the Au-silacycle coupling.