No abstract

Ga-DOTATOC, a somatostatin receptor-targeted ligand, has been used clinically in Europe over the past decade for imaging neuroendocrine tumors (NETs). It appears to be quite sensitive and effective for clinical management decision making. This metaanalysis summarizes the efficacy of Ga-DOTATOC for several distinct indications and is intended to support approval of this agent by the U.S. Food and Drug Administration. The major electronic medical databases were searched for relevant papers over the period from January 2001 to November 2015. Papers were selected for review in 3 categories: clinical trials that reported sensitivity and specificity, comparison studies with In-octreotide, and change of management studies. All the eligible papers underwent Quality Assessment of Diagnostic Accuracy Studies (QUADAS) assessment, which was useful in the final selection of papers for review. The initial search yielded 468 papers. After detailed evaluation, 17 papers were finally selected. Five types of studies emerged: workup of patients with symptoms and biomarker findings suggestive of NET, but with negative conventional imaging (3 papers, yield was only 13%); sensitivity (12 papers; sensitivity, 92%) and specificity (7 papers; specificity, 82%); identification of site of unknown primary in patients with metastatic NET (4 papers, yield was 44%); impact on subsequent NET patient management (4 papers, change in management in 51%); and comparison with In-octreotide (2 papers, sensitivity of DOTATOC on a per-lesion basis was 100%, forIn-octreotide it was 78.2%; specificity was not available). Safety was not explicitly addressed in any study, but there were no reports of adverse events. Ga-DOTATOC is useful for evaluating the presence and extent in disease for staging and restaging and for assisting in treatment decision making for patients with NET. It is also effective in locating the site of an unknown primary in NET patients who present with metastatic NET, but no known primary tumor. It also appears to be more accurate thanIn-octreotide. Although Ga-DOTATOC would seem to be useful in evaluating patients with suggestive symptoms and biomarker findings, it does not perform well in this setting and has low yield. Overall, it appears to be an excellent imaging agent to assess patients with known NET and frequently leads to a change in management.

BackgroundTotal knee arthroplasty is an effective treatment when nonsurgical treatments fail, but it is associated with risk of complications which may be increased in advanced age. The purpose of this study was to quantify age-related differences in perioperative morbidity and mortality after total knee arthroplasty through systematic review of existing literature.MethodsPubMed, the Cochrane database of systematic reviews, Scopus, and clinicaltrials.gov, were queried for relevant studies that compared primary total knee arthroplasty outcomes of mortality, myocardial infarction (MI), deep vein thrombosis (DVT), pulmonary embolism (PE) and functional status, of geriatric patients (>75 years old) with a younger control group (<65 years old). Pertinent journals and reference lists were hand searched. Eligibility criteria included all articles except case reports, meta-analyses, and systematic reviews. Two authors independently extracted data from each paper. Article quality was assessed using the Newcastle-Ottawa Scale.ResultsTwenty-two studies were included. Geriatric patients had higher rates of mortality, MI, DVT, and length of stay in older compared to younger patients, however the absolute magnitude of these increases were small. The increase in mortality may have reflected decreased life expectancy in the geriatric populations as opposed to mortality specifically due perioperative risk. There were no differences in PE incidence and improvement in pain and functional status was equal in older and younger patients. Existing studies were limited by non-randomized patient selection, as well as variation in definitions and methodology.ConclusionsExisting data supports offering primary total knee arthroplasty to select geriatric patients, although the risk of complications may be increased. Much of the data was of poor quality. Future prospective studies are needed to better identify risks and benefits of total knee arthroplasty so that patients and surgeons can make informed decisions.Electronic supplementary materialThe online version of this article (doi:10.1186/s12877-016-0215-4) contains supplementary material, which is available to authorized users.

Perturbation of organic anion transporter (OAT) 1- and OAT3-mediated transport can alter the exposure, efficacy, and safety of drugs. Although there have been reports of the endogenous biomarkers for OAT1/3, none of these have all of the characteristics required for a clinical useful biomarker. Cynomolgus monkeys were treated with intravenous probenecid (PROB) at a dose of 40 mg/kg in this study. As expected, PROB increased the area under the plasma concentration-time curve (AUC) of coadministered furosemide, a known substrate of OAT1 and OAT3, by 4.1-fold, consistent with the values reported in humans (3.1- to 3.7-fold). Of the 233 plasma metabolites analyzed using a liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based metabolomics method, 29 metabolites, including pyridoxic acid (PDA) and homovanillic acid (HVA), were significantly increased after either 1 or 3 hours in plasma from the monkeys pretreated with PROB compared with the treated animals. The plasma of animals was then subjected to targeted LC-MS/MS analysis, which confirmed that the PDA and HVA AUCs increased by approximately 2- to 3-fold by PROB pretreatments. PROB also increased the plasma concentrations of hexadecanedioic acid (HDA) and tetradecanedioic acid (TDA), although the increases were not statistically significant. Moreover, transporter profiling assessed using stable cell lines constitutively expressing transporters demonstrated that PDA and HVA are substrates for human OAT1, OAT3, OAT2 (HVA), and OAT4 (PDA), but not OCT2, MATE1, MATE2K, OATP1B1, OATP1B3, and sodium taurocholate cotransporting polypeptide. Collectively, these findings suggest that PDA and HVA might serve as blood-based endogenous probes of cynomolgus monkey OAT1 and OAT3, and investigation of PDA and HVA as circulating endogenous biomarkers of human OAT1 and OAT3 function is warranted.

Odontogenic keratocysts are relatively common lesions that may occur in isolation or in association with nevoid basal cell carcinoma syndrome (or Gorlin syndrome). The PTCH gene has been reported to be associated with Gorlin syndrome. We investigated 10 cases of non-syndromic keratocysts and two other cases associated with Gorlin syndrome, looking for PTCH mutations. Four novel and 1 known PTCH mutations were identified in five individual patients. Of the 5 mutations identified, 2 were germ-line mutations (2619C>A; 1338_1339insGCG) in 2 cysts associated with Gorlin syndrome, and 3 were somatic mutations (3124_3129dupGTGTGC; 1361_1364delGTCT; 3913G>T) in 3 non-syndromic cysts. This report describes PTCH mutations in both non-syndromic and Gorlin-syndrome-related odontogenic keratocysts in Chinese patients, and suggests that defects of PTCH are associated with the pathogenesis of syndromic as well as a subset of non-syndromic keratocysts.

As the central hub of the metabolism machinery, the mammalian target of rapamycin complex 2 (mTORC2) has been well studied in lymphocytes. As an obligatory component of mTORC2, the role of Rictor in T cells is well established. However, the role of Rictor in B cells still remains elusive. Rictor is involved in B cell development, especially the peripheral development. However, the role of Rictor on B cell receptor (BCR) signaling as well as the underlying cellular and molecular mechanism is still unknown. This study used B cell–specfic Rictor knockout (KO) mice to investigate how Rictor regulates BCR signaling. We found that the key positive and negative BCR signaling molecules, phosphorylated Brutons tyrosine kinase (pBtk) and phosphorylated SH2-containing inositol phosphatase (pSHIP), are reduced and enhanced, respectively, in Rictor KO B cells. This suggests that Rictor positively regulates the early events of BCR signaling. We found that the cellular filamentous actin (F-actin) is drastically increased in Rictor KO B cells after BCR stimulation through dysregulating the dephosphorylation of ezrin. The high actin-ezrin intensity area restricts the lateral movement of BCRs upon stimulation, consequently reducing BCR clustering and BCR signaling. The reduction in the initiation of BCR signaling caused by actin alteration is associated with a decreased humoral immune response in Rictor KO mice. The inhibition of actin polymerization with latrunculin in Rictor KO B cells rescues the defects of BCR signaling and B cell differentiation. Overall, our study provides a new pathway linking cell metablism to BCR activation, in which Rictor regulates BCR signaling via actin reorganization.

The covalent conjugation of polyethylene glycol (PEG, typical MW > 10k) to therapeutic peptides and proteins is a well-established approach to improve their pharmacokinetic properties and diminish the potential for immunogenicity. Even though PEG is generally considered biologically inert and safe in animals and humans, the slow clearance of large PEGs raises concerns about potential adverse effects resulting from PEG accumulation in tissues following chronic administration, particularly in the central nervous system. The key information relevant to the issue is the disposition and fate of the PEG moiety after repeated dosing with PEGylated proteins. Here, we report a novel quantitative method utilizing LC-MS/MS coupled with in-source CID that is highly selective and sensitive to PEG-related materials. Both (40K)PEG and a tool PEGylated protein (ATI-1072) underwent dissociation in the ionization source of mass spectrometer to generate a series of PEG-specific ions, which were subjected to further dissociation through conventional CID. To demonstrate the potential application of the method to assess PEG biodistribution following PEGylated protein administration, a single dose study of ATI-1072 was conducted in rats. Plasma and various tissues were collected, and the concentrations of both (40K)PEG and ATI-1072 were determined using the LC-MS/MS method. The presence of (40k)PEG in plasma and tissue homogenates suggests the degradation of PEGylated proteins after dose administration to rats, given that free PEG was absent in the dosing solution. The method enables further studies for a thorough characterization of disposition and fate of PEGylated proteins.

1Prior case reports and observational studies indicate that intravenous immune globulin (IVIg) products may cause thromboembolic events (TEEs), leading the FDA to require a boxed warning in 2013. The effect of IVIg treatment on the risk of serious TEEs (acute myocardial infarction, ischemic stroke, or venous thromboembolism) was assessed using adverse event data reported in randomized controlled trials (RCTs) of IVIg. RCTs of IVIg in adult patients from 1995 to 2015 were identified from Pubmed, Embase, ClinicalTrials.Gov, and two large prior reviews of IVIg's therapeutic applications. Trials at high risk of detection or reporting bias for serious adverse events were excluded. 31 RCTs with a total of 4,129 participants (2,318 IVIg-treated, 1,811 control) were eligible for quantitative synthesis. No evidence was found of increased TEE risk among IVIg-treated patients compared with control patients (odds ratio 5 1.10, 95% CI: 0.44, 2.88; risk difference 5 0.0%, 95% CI: 20.7%, 0.7%, I2 5 0%). No significant increase in risk was found when arterial and venous TEEs were analyzed as separate endpoints. Trial publications provided little specific information concerning the methods used to ascertain potential adverse events. Care should be taken in extrapolating the results to patients with higher baseline risks of TEE.