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951.
Thaissa Dantas Pessoa Luciene Cristina Gastalho Campos Luciene Carraro-Lacroix Adriana C.C. Girardi Gerhard Malnic 《Journal of the American Society of Nephrology : JASN》2014,25(9):2028-2039
Na+-glucose cotransporter 1 (SGLT1)-mediated glucose uptake leads to activation of Na+-H+ exchanger 3 (NHE3) in the intestine by a process that is not dependent on glucose metabolism. This coactivation may be important for postprandial nutrient uptake. However, it remains to be determined whether SGLT-mediated glucose uptake regulates NHE3-mediated NaHCO3 reabsorption in the renal proximal tubule. Considering that this nephron segment also expresses SGLT2 and that the kidneys and intestine show significant variations in daily glucose availability, the goal of this study was to determine the effect of SGLT-mediated glucose uptake on NHE3 activity in the renal proximal tubule. Stationary in vivo microperfusion experiments showed that luminal perfusion with 5 mM glucose stimulates NHE3-mediated bicarbonate reabsorption. This stimulatory effect was mediated by glycolytic metabolism but not through ATP production. Conversely, luminal perfusion with 40 mM glucose inhibited NHE3 because of cell swelling. Notably, pharmacologic inhibition of SGLT activity by Phlorizin produced a marked inhibition of NHE3, even in the absence of glucose. Furthermore, immunofluorescence experiments showed that NHE3 colocalizes with SGLT2 but not SGLT1 in the rat renal proximal tubule. Collectively, these findings show that glucose exerts a bimodal effect on NHE3. The physiologic metabolism of glucose stimulates NHE3 transport activity, whereas, supraphysiologic glucose concentrations inhibit this exchanger. Additionally, Phlorizin-sensitive SGLT transporters and NHE3 interact functionally in the proximal tubule.The kidney proximal tubule (PT) is the site where the reabsorption of approximately 70% of filtered sodium bicarbonate occurs. It is mainly performed by the Na+/H+ exchanger isoform 3 (NHE3).1 The physiologic importance of NHE3 became evident after the development of NHE3 knockout mice, which presented mild metabolic acidosis and volume depletion with reduced BP, underscoring the role of NHE3 in volume homeostasis.2It has been shown that NHE3 physically and functionally interacts with dipeptidyl-peptidase IV, an enzyme that degrades and inactivates the incretin hormone glucagon like peptide-1.3 The inhibition of dipeptidyl-peptidase IV and the action of glucagon like peptide-1 were shown to inhibit NHE3 and promote natriuresis.3–8 Additionally, various conditions and substances related to glucose metabolism, including diabetes, insulin, ATP, and glucose, modulate NHE3 in different tissues, showing a close relationship between carbohydrate homeostasis and NHE3 activity.9–12Plasma glucose concentration is maintained at a constant level by a complex system, in which the kidneys perform a pivotal role by reabsorbing all the filtered glucose in the PT.13 In addition, the kidneys and liver are the only organs that express the glucose-6-phosphatase enzyme, thus enabling them to perform gluconeogenesis.14,15 This enzyme is only expressed in the PT,16 highlighting the importance of this kidney segment in carbohydrate metabolism.It has been shown that the kidneys metabolize 20% of the glucose consumed in a meal.14 The PT has a low expression of hexokinase but the highest concentration and activity of glucose-6-phosphate dehydrogenase, indicating that this segment is able to metabolize glucose.16,17 However, it is currently believed that the PT uses noncarbohydrate compounds as energy sources.17With relation to glucose uptake, the majority of filtered glucose is reabsorbed by the low-affinity, high-capacity sodium-glucose cotransporter isoform 2 (SGLT2). Some glucose is also reabsorbed by the high-affinity, low-capacity sodium-glucose cotransporter isoform 1 (SGLT1).13 Recently, SGLT2 inhibitors have been approved for the treatment of hyperglycemia in diabetic patients. The use of these inhibitors has been shown to decrease blood glucose, glycated hemoglobin, postprandial glucose, insulinemia, and body weight.18–20The role of glucose uptake in the modulation of NHE3 activity in the small intestine has been extensively studied. Experiments have shown that glucose uptake through SGLT1 promotes intracellular NHE3-dependent alkalinization.21–26 However, functional differences between intestinal and renal NaHCO3 NHE3-mediated reabsorption have not been established. These two systems differ physiologically, because the gastrointestinal system is exposed to fluctuations in glucose concentration between the periods of fasting and after meals.13 The presence of large amounts of solutes within the intestinal cells after meals modulates membrane transporters, such as glucose transporter 2 (GLUT2) and NHE3,21,27 an important process for nutrient absorption.Although the synergistic activation between SGLT1 and NHE3 has been observed in the intestine,21 it is not known if this process also occurs in the kidneys. Considering that the kidneys also express SGLT2 and the particularities of glucose availability in this organ, the goal of the present work was to determine the effect of glucose and SGLT activity on NHE3 in the renal PT. 相似文献
952.
Tracy-Ann Moo MD Lydia Choi MD Candice Culpepper MD Cristina Olcese BS Alexandra Heerdt MD Lisa Sclafani MD Tari A. King MD Anne S. Reiner MPH Sujata Patil PhD Edi Brogi MD Monica Morrow MD Kimberly J. Van Zee MS MD 《Annals of surgical oncology》2014,21(1):86-92
Background
For breast-conserving surgery, the method of margin assessment that most frequently achieves negative margins without increasing the volume of tissue excised is uncertain. We examined our institutional experience with three different margin assessment methods used by six experienced breast surgeons.Methods
Patients undergoing breast-conserving surgery for invasive carcinoma during July to December of a representative year during which each method was performed (perpendicular, 2003; tangential, 2004; cavity shave, 2011) were included. The effect of margin method on the positive margin rate at first excision and the total volume excised to achieve negative margins were evaluated by multivariable analysis, by surgeon, and by tumor size and presence of extensive intraductal component (EIC).Results
A total of 555 patients were identified, as follows: perpendicular, 140; tangential, 124; and cavity shave, 291. The tangential method had a higher rate of positive margins at first excision than the perpendicular and cavity-shave methods (49, 15, 11 %, respectively; p < 0.0001). Median volumes to achieve negative margins were similar (55 ml perpendicular; 64 ml tangential; 62 ml cavity shave; p = 0.24). Four of six surgeons had the lowest rate of positive margins with the cavity-shave method, which was significant when compared to the tangential method (p < 0.0001) but not the perpendicular method (p = 0.37). The volume excised by the three methods varied by surgeon (p < 0.0001). The perpendicular method was optimal for T1 tumors without EIC; the cavity-shave method tended to be superior for T2–T3 tumors and/or EIC.Conclusions
Although the cavity-shave method may decrease the rates of positive margins, its effect on volume is variable among surgeons and may result in an increase in the total volume excised for some surgeons and for small tumors without EIC. 相似文献953.
Melissa Pilewskie MD Cristina Olcese BS Anne Eaton MS Sujata Patil PhD Elizabeth Morris MD Monica Morrow MD Kimberly J. Van Zee MS MD 《Annals of surgical oncology》2014,21(5):1552-1560
Introduction
For women with ductal carcinoma in situ (DCIS) undergoing breast-conserving surgery (BCS), the benefit of magnetic resonance imaging (MRI) remains unknown. Here we examine the relationship of MRI and locoregional recurrence (LRR) and contralateral breast cancer (CBC) for DCIS treated with BCS, with and without radiotherapy (RT).Methods
A total of 2,321 women underwent BCS for DCIS from 1997 to 2010. All underwent mammography, and 596 (26 %) also underwent perioperative MRI; 904 women (39 %) did not receive RT, and 1,391 (61 %) did. Median follow-up was 59 months, and 548 women were followed for ≥8 years. The relationship between MRI and LRR was examined using multivariable analysis.Results
There were 184 LRR events; 5- and 8-year LRR rates were 8.5 and 14.6 % (MRI), respectively, and 7.2 and 10.2 % (no-MRI), respectively (p = 0.52). LRR was significantly associated with age, menopausal status, margin status, RT, and endocrine therapy. After controlling for these variables and family history, presentation, number of excisions, and time period of surgery, there remained no trend toward association of MRI and lower LRR [hazard ratio (HR) 1.18, 95 % confidence interval (CI) 0.79–1.78, p = 0.42]. Restriction of analysis to the no-RT subgroup showed no association of MRI with lower LRR rates (HR 1.36, 95 % CI 0.78–2.39, p = 0.28). No difference in 5- or 8-year rates of CBC was seen between the MRI (3.5 and 3.5 %) and no-MRI (3.5 and 5.1 %) groups (p = 0.86).Conclusions
We observed no association between perioperative MRI and lower LRR or CBC rates in patients with DCIS, with or without RT. In the absence of evidence that MRI improves outcomes, the routine perioperative use of MRI for DCIS should be questioned. 相似文献954.
Andrew X. Zhu MD Darrell R. Borger MD Yuhree Kim MD David Cosgrove MD Aslam Ejaz MD Sorin Alexandrescu MD Ryan Thomas Groeschl MD Vikram Deshpande MD James M. Lindberg MD Cristina Ferrone MD Christine Sempoux MD Thomas Yau MD Ronnie Poon MD Irinel Popescu MD Todd W. Bauer MD T. Clark Gamblin MD Jean Francois Gigot MD Robert A. Anders MD Timothy M. Pawlik MD MPH PhD 《Annals of surgical oncology》2014,21(12):3827-3834
Background
The molecular alterations that drive tumorigenesis in intrahepatic cholangiocarcinoma (ICC) remain poorly defined. We sought to determine the incidence and prognostic significance of mutations associated with ICC among patients undergoing surgical resection.Methods
Multiplexed mutational profiling was performed using nucleic acids that were extracted from 200 resected ICC tumor specimens from 7 centers. The frequency of mutations was ascertained and the effect on outcome was determined.Results
The majority of patients (61.5 %) had no genetic mutation identified. Among the 77 patients (38.5 %) with a genetic mutation, only a small number of gene mutations were identified with a frequency of >5 %: IDH1 (15.5 %) and KRAS (8.6 %). Other genetic mutations were identified in very low frequency: BRAF (4.9 %), IDH2 (4.5 %), PIK3CA (4.3 %), NRAS (3.1 %), TP53 (2.5 %), MAP2K1 (1.9 %), CTNNB1 (0.6 %), and PTEN (0.6 %). Among patients with an IDH1-mutant tumor, approximately 7 % were associated with a concurrent PIK3CA gene mutation or a mutation in MAP2K1 (4 %). No concurrent mutations in IDH1 and KRAS were noted. Compared with ICC tumors that had no identified mutation, IDH1-mutant tumors were more often bilateral (odds ratio 2.75), while KRAS-mutant tumors were more likely to be associated with R1 margin (odds ratio 6.51) (both P < 0.05). Although clinicopathological features such as tumor number and nodal status were associated with survival, no specific mutation was associated with prognosis.Conclusions
Most somatic mutations in resected ICC tissue are found at low frequency, supporting a need for broad-based mutational profiling in these patients. IDH1 and KRAS were the most common mutations noted. Although certain mutations were associated with ICC clinicopathological features, mutational status did not seemingly affect long-term prognosis. 相似文献955.
Renato Salvador Mario Costantini Francesco Cavallin Lisa Zanatta Elena Finotti Cristina Longo Loredana Nicoletti Giovanni Capovilla Romeo Bardini Giovanni Zaninotto 《Journal of gastrointestinal surgery》2014,18(1):106-112
Introduction
Laparoscopic Heller-Dor surgery is the current treatment of choice for patients with esophageal achalasia, but elderly patients are generally referred for less invasive treatments (pneumatic dilations or botulinum toxin injections).Aim
To assess the effect of age on the surgical outcome of patients receiving laparoscopic Heller-Dor as primary treatment.Methods
Demographic and clinical findings were prospectively collected on patients undergoing laparoscopic Heller-Dor from 1992 to 2012. Patients were classified in three age brackets: group A (≤45 years), group B (45–70), and group C (≥70). Treatment was defined as a failure if the postoperative symptom score was >10th percentile of the preoperative score (i.e., >8). We consecutively performed the Heller-Dor in 571 achalasia patients, 305 (53.4 %) in group A, 226 (39.6 %) in group B, and 40 (7 %) in group C.Results
The mortality was nil; the conversion and morbidity rates were both 1.1 %. Group C patients had higher preoperative symptom scores (p?=?0.02), while the symptom duration was similar in all three groups. Mucosal tears occurred in 17 patients (3 %): 6 (2 %) in group A, 8 (3.5 %) in group B, and 3 (7.5 %) in group C (p?=?0.09). The postoperative hospital stay was slightly longer for group C (p?=?0.06).Discussion
The treatment failure rate was quite similar: 31 failures in group A (10.1 %), 19 in group B (8.4 %), and 3 in group C (7.5 %; p?=?0.80). These failures were seen more in manometric pattern III (22.2 %, p?=?0.002). Laparoscopic Heller-Dor can be used as the first therapeutic approach to achalasia even in elderly patients with an acceptable surgical risk. 相似文献956.
Manuel Mateo-March Eneko Fernández-Pe?a Cristina Blasco-Lafarga Jaime Morente-Sánchez Mikel Zabala 《Journal of Sports Science and Medicine》2014,13(1):97-104
Maximising power output during the initial acceleration phase of a bicycle motocross (BMX) race increases the chance to lead the group for the rest of the race. The purpose of this study was to investigate the effect of non-circular chainrings (Q-ring) on performance during the initial acceleration phase of a BMX race. Sixteen male cyclists (Spanish National BMX team) performed two counterbalanced and randomized initial sprints (3.95s), using Q- ring vs. circular chainring, on a BMX track. The sample was divided into two different groups according to their performance (Elite; n = 8 vs. Cadet; n = 8). Elite group covered a greater distance using Q-ring (+0.26 m, p = 0.02; D = 0.23), whilst the improvement for the Cadet (+0.04 m) was not significant (p = 0.87; D = -0.02). Also, there was no significant difference in power output for the Elite group, while the Cadet group revealed larger peak power with the circular chainring. Neither lactate level, nor heart rate showed significant differences due to the different chainring used. The non-circular chainring improved the initial acceleration capacity only in the Elite riders.
Key Points
- This work provides novel results demonstrating very significant improvements in the sprint performance of BMX cycling discipline using a non-circular chainring system.
- This study seeks a practical application from scientific analysis
- All data are obtained in a real context of high competition using a sample comprised by the National Spanish Team.
- Some variables influencing performance as subjects’ physical fitness are discussed.
- Technical equipment approved by International Cycling Union is studied to check its potentially beneficial influence on performance.
957.
958.
Emily Brede Tom G. Mayer Whitney E. Worzer Maile Shea Cristina Garcia Robert J. Gatchel 《The spine journal》2014,14(8):1686-1693
Background contextFor chronic pain patients, recovery may be slowed by indecisiveness over optional surgery. These patients may be delayed from participating in interdisciplinary functional restoration (FR), pending resolution of the surgical decision. Uncertainty about surgery or rehabilitation leads to delayed recovery. A surgical option process (SOP) was developed to permit patients with chronic disabling occupational musculoskeletal disorders to enter FR, make a final determination halfway through treatment, and return to complete rehabilitation after surgery, if surgery was elected.PurposeThis study assessed the frequency with which an FR program can resolve an uncertain surgical option. It also assessed program completion rate and 1-year post-program outcomes for subgroups that decline surgery, request and receive surgery, or request surgery but are denied by surgeon or insurance carrier.Study designRetrospective study of a consecutive cohort.Patient sampleA cohort of 44 consecutively treated chronic disabling occupational musculoskeletal disorder patients were admitted to an FR program and identified as candidates for a surgical procedure but were either ambivalent about undergoing surgery, had a difference of opinion by two or more surgeons, or were denied a surgical request by an insurance carrier. Patients attended half (10 full day visits) of an FR program before making their own final determination to pursue a request or decline surgery.Outcome measuresPatients were assessed on surgical requests and whether surgery was ultimately performed, program completion status after the surgical determination, demographic variables, and 1-year outcomes on work status, additional surgery, and other health utilization measures.MethodsPatients became part of the SOP on program entry and were included in the study if they participated in a surgical-decision interview halfway through the program. Those who elected to decline surgery (DS) completed the program without delay, but those requesting surgery were placed on hold from the program while consultation and preauthorization steps took place. Those requesting surgery, but denied (RSD), and those undergoing surgery (US) were given the opportunity to complete FR following postoperative physical therapy or resolution of the surgical re-evaluation process.ResultsThere were 32 DS patients (73%), indicating that a large majority of patients declined the surgery that was still being considered when offered participation in the SOP. Of the 12 patients wanting a surgery, there were four US patients who received surgery previously denied (9% of cohort), and eight RSD patients (18% of cohort). Patients from the DS group completed the FR program at an 88% rate, as did 75% of US patients. However, despite an opportunity to re-enter and complete rehab, only 50% of RSD patients completed the FR option. Overall, patients who persistently sought surgery, contrary to the recommendations of a surgeon, had poorer outcomes. These 1-year post-FR outcomes included lower return-to-work and work retention rates, with higher rates of treatment seeking from new providers (resulting in higher rates of post-discharge surgery) and higher rates of recurrent injury claims after work return.ConclusionsA SOP tied to participation in an interdisciplinary FR program resolves uncertainty regarding surgical options in a high proportion of cases, resulting in a large majority declining surgery and completing the FR program. Timely surgery is also promoted decisively when needed. Findings suggest that patients who persistently seek surgery, contrary to the recommendations of a surgeon, frequently fail to complete FR and have poorer outcomes overall. 相似文献
959.
Josep Antoni Ramos-Quiroga Margarida Corominas-Roso Gloria Palomar Nuria Gomez-Barros Marta Ribases Cristina Sanchez-Mora Rosa Bosch Mariana Nogueira Montserrat Corrales Sergi Valero Miguel Casas 《Psychopharmacology》2014,231(7):1389-1395
Rationale
Atomoxetine (ATX) is a non-stimulant drug approved for the treatment of attention deficit hyperactivity disorder (ADHD). Although animal models have provided evidence that brain-derived neurotrophic factor (BDNF) is involved in the effects of ATX in the brain, there are no studies of BDNF in ADHD patients undergoing treatment with ATX.Objectives
The aim of this study was to evaluate the possible changes in serum levels of BDNF in adults treated with ATX and its relationship with clinical improvement.Methods
A total of 54 adults with ADHD (age 33.43?±?8.99 years) without any medical or psychiatric comorbidities were treated with ATX for 3 months; 35 of them completed the protocol. The clinical data for ADHD diagnosis, including Conners’ ADHD Rating Scale and blood samples, were collected at baseline (V1) and at the end of the treatment (V2).Results
Adults with ADHD who completed ATX treatment for 3 months showed a significant improvement in their clinical symptoms. No significant differences were found in BDNF levels before and after treatment with ATX in the whole group of patients (p?=?0.15). The inattentive subgroup of ATX responders showed a decrease of serum BDNF after 3 months of ATX treatment (p?=?0.05) not present in the combined subtype (p?=?0.82).Conclusions
These results suggest that BDNF is not directly involved in the neurobiological mechanisms of ATX-induced improvement of clinical symptoms of ADHD. The differences between the combined and inattentive subtypes in serum BDNF changes suggest selective ATX-induced effects in the function of brain circuitry. 相似文献960.
Alexandru Mihai Grumezescu Cristina Daniela Ghitulica Georgeta Voicu Keng-Shiang Huang Chih-Hui Yang Anton Ficai Bogdan Stefan Vasile Valentina Grumezescu Coralia Bleotu Mariana Carmen Chifiriuc 《International journal of pharmaceutics》2014
In this paper, we report the synthesis, characterization (FT-IR, XRD, BET, HR-TEM) and bioevaluation of a novel γ-aminobutiric acid/silica (noted GABA-SiO2 or γ-SiO2) hybrid nanostructure, for the improved release of topical antibiotics, used in the treatment of Staphylococcus aureus infections. GABA-SiO2 showed IR bands which were assigned to Si–O–Si (stretch mode). The XRD pattern showed a broad peak in the range of 18–30° (2θ), indicating an amorphous structure. Based on the BET analysis, estimations about surface area (438.14 m2/g) and pore diameters (4.76 nm) were done. TEM observation reveals that the prepared structure presented homogeneity and an average size of particles not exceeding 10 nm. The prepared nanostructure has significantly improved the anti-staphylococcal activity of bacitracin and kanamycin sulfate, as demonstrated by the drastic decrease of the minimal inhibitory concentration of the respective antibiotics loaded in the GABA-SiO2 nanostructure. These results, correlated with the high biocompatibility of this porous structure, are highlighting the possibility of using this carrier for the local delivery of the antimicrobial substances in lower active doses, thus reducing their cytotoxicity and side-effects. 相似文献