Role of PKC and AMPK in hypertonicity-stimulated water reabsorption in rat inner medullary collecting ducts.

Hypertonicity increases water permeability, independently of vasopressin, in the inner medullary collecting duct (IMCD) by increasing aquaporin-2 (AQP2) membrane accumulation. We investigated whether protein kinase C (PKC) and adenosine monophosphate kinase (AMPK) are involved in hypertonicity-regulated water permeability. Increasing perfusate osmolality from 150 to 290 mosmol/kgH2O and bath osmolality from 290 to 430 mosmol/kgH2O significantly stimulated osmotic water permeability. The PKC inhibitors chelerythrine (10 µM) and rottlerin (50 µM) significantly reversed the increase in osmotic water permeability stimulated by hypertonicity in perfused rat terminal IMCDs. Chelerythrine significantly increased phosphorylation of AQP2 at S261 but not at S256. Previous studies show that AMPK is stimulated by osmotic stress. We tested AMPK phosphorylation under hypertonic conditions. Hypertonicity significantly increased AMPK phosphorylation in inner medullary tissues. Blockade of AMPK with Compound C decreased hypertonicity-stimulated water permeability but did not alter phosphorylation of AQP2 at S256 and S261. AICAR, an AMPK stimulator, caused a transient increase in osmotic water permeability and increased phosphorylation of AQP2 at S256. When inner medullary tissue was treated with the PKC activator phorbol dibutyrate (PDBu), the AMPK activator metformin, or both, AQP2 phosphorylation at S261 was decreased with PDBu or metformin alone, but there was no additive effect on phosphorylation with PDBu and metformin together. In conclusion, hypertonicity regulates water reabsorption by activating PKC. Hypertonicity-stimulated water reabsorption by PKC may be related to the decrease in endocytosis of AQP2. AMPK activation promotes water reabsorption, but the mechanism remains to be determined. PKC and AMPK do not appear to act synergistically to regulate water reabsorption.

Phosphatase inhibition increases AQP2 accumulation in the rat IMCD apical plasma membrane.

Vasopressin triggers the phosphorylation and apical plasma membrane accumulation of aquaporin 2 (AQP2), and it plays an essential role in urine concentration. Vasopressin, acting through protein kinase A, phosphorylates AQP2. However, the phosphorylation state of AQP2 could also be affected by the action of protein phosphatases (PPs). Rat inner medullas (IM) were incubated with calyculin (PP1 and PP2A inhibitor, 50 nM) or tacrolimus (PP2B inhibitor, 100 nM). Calyculin did not affect total AQP2 protein abundance (by Western blot) but did significantly increase the abundances of pS256-AQP2 and pS264-AQP2. It did not change pS261-AQP2 or pS269-AQP2. Calyculin significantly enhanced the membrane accumulation (by biotinylation) of total AQP2, pS256-AQP2, and pS264-AQP2. Likewise, immunohistochemistry showed an increase in the apical plasma membrane association of pS256-AQP2 and pS264-AQP2 in calyculin-treated rat IM. Tacrolimus also did not change total AQP2 abundance but significantly increased the abundances of pS261-AQP2 and pS264-AQP2. In contrast to calyculin, tacrolimus did not change the amount of total AQP2 in the plasma membrane (by biotinylation and immunohistochemistry). Tacrolimus did increase the expression of pS264-AQP2 in the apical plasma membrane (by immunohistochemistry). In conclusion, PP1/PP2A regulates the phosphorylation and apical plasma membrane accumulation of AQP2 differently than PP2B. Serine-264 of AQP2 is a phosphorylation site that is regulated by both PP1/PP2A and PP2B. This dual regulatory pathway may suggest a previously unappreciated role for multiple phosphatases in the regulation of urine concentration.

Metformin, an AMPK activator, stimulates the phosphorylation of aquaporin 2 and urea transporter A1 in inner medullary collecting ducts.

Nephrogenic diabetes insipidus (NDI) is characterized by production of very large quantities of dilute urine due to an inability of the kidney to respond to vasopressin. Congenital NDI results from mutations in the type 2 vasopressin receptor (V2R) in ∼90% of families. These patients do not have mutations in aquaporin-2 (AQP2) or urea transporter UT-A1 (UT-A1). We tested adenosine monophosphate kinase (AMPK) since it is known to phosphorylate another vasopressin-sensitive transporter, NKCC2 (Na-K-2Cl cotransporter). We found AMPK expressed in rat inner medulla (IM). AMPK directly phosphorylated AQP2 and UT-A1 in vitro. Metformin, an AMPK activator, increased phosphorylation of both AQP2 and UT-A1 in rat inner medullary collecting ducts (IMCDs). Metformin increased the apical plasma membrane accumulation of AQP2, but not UT-A1, in rat IM. Metformin increased both osmotic water permeability and urea permeability in perfused rat terminal IMCDs. These findings suggest that metformin increases osmotic water permeability by increasing AQP2 accumulation in the apical plasma membrane but increases urea permeability by activating UT-A1 already present in the membrane. Lastly, metformin increased urine osmolality in mice lacking a V2R, a mouse model of congenital NDI. We conclude that AMPK activation by metformin mimics many of the mechanisms by which vasopressin increases urine-concentrating ability. These findings suggest that metformin may be a novel therapeutic option for congenital NDI due to V2R mutations.

Extracorporeal Shockwave Therapy for Greater Trochanteric Pain Syndrome: A Systematic Review with Meta-Analysis of Randomized Clinical Trials.

BACKGROUND: Greater trochanteric pain syndrome (GTPS) affects 17.6% of adults aged 50 to 79 years, particularly women. While exercise therapy and corticosteroid injections (CSIs) are common treatments, their limitations include inadequate pain control and potential tendon weakening. Extracorporeal shockwave therapy (ESWT) is an emerging alternative for GTPS. This systematic review assessed ESWT's efficacy in GTPS by evaluating pain and functional outcomes at different follow-up intervals. METHODS: A literature search of PubMed, Embase, and Web of Science for randomized clinical trials (RCTs) was conducted comparing ESWT with other GTPS treatments up to March 1, 2024. Two reviewers independently extracted data, assessing study quality using the Cochrane risk-of-bias tool. A random-effects pairwise meta-analysis compared ESWT with other treatments. RESULTS: Eight RCTs involving 754 patients (169 male, 585 female patients) were included. Seven RCTs were deemed high risk of bias, and 1 RCT had some concerns. Five RCTs investigated focused on focused ESWT, and 3 examined radial ESWT. ESWT provided significantly lower pain scores than other treatments at 2 to 4 months (standardized mean difference = -0.431; 95% confidence interval [CI], -0.82 to -0.039; I2 = 83%). Functional improvement (Lower Extremity Functional Scale) was significantly higher at 6 months (weighted mean difference = 6.68; 95% CI, 3.11-10.25; I2 = 0%) but did not exceed the minimal clinically important difference. Focused ESWT provided greater pain reduction than radial ESWT. CONCLUSION: Three weekly ESWT sessions offer short-term pain relief at 2 to 4 months for patients with GTPS, especially with focused ESWT. Functional improvements at 6 months were notable but not clinically significant. These findings suggest ESWT may complement or serve as an alternative to CSIs and exercise. However, caution is needed when interpreting these results due to high risk of bias with the included RCTs and heterogeneity across the studies. Further high-quality trials are needed to confirm ESWT's long-term benefits over other treatments. LEVEL OF EVIDENCE: Level II. See Instructions for Authors for a complete description of levels of evidence.

Epidemiology of injuries in united states high school track and field jumping events from 2008 - 2019.

OBJECTIVES: Reports of injury characteristics of high school track and field athletes participating in jumping events in the United States are limited. In this descriptive epidemiological study, we report injury rates and patterns in these athletes. METHODS: Injuries and athletic exposures (AE) from the National High School Sports Related Injury Surveillance System, and High School Reporting Information Online (RIO) from 2008-2019 were analyzed. Jumping events included high jump, long jump, triple jump, and pole vault. Injury rate ratios (IRR) and injury proportion ratios (IPR) were examined by sex. RESULTS: A total of 727 injuries related to jumping events during 5,486,279 AEs occurred with the highest frequency at the thigh (20.3%) followed by the ankle (18.2%), knee (16.1%), and lower leg (11.0%). The most common types of injuries were muscle strain (29.0%) and ligament sprain (21.2%). Most athletes returned to sport within 1 week (43.1%, n = 312) or 3 weeks (34.7%, n = 243). Few jumping-related injuries resulted in surgery (4.9%, n = 35) or medical disqualification (4.4%, n = 31). The jumping-related injury rate was 1.33 injuries/10,000 AEs from 2008 to 2019. The rate of jumping-related injuries was higher in competition than in practice (IRR = 2.63, 95% confidence interval [CI]: 2.25-3.06). Injury rates were significantly higher in practice for female athletes than for males (IRR = 1.51, 95% CI: 1.23-1.86). Compared to male athletes, female athletes sustained a higher proportion of ankle injuries (IPR = 1.63, 95% CI: 1.15-2.32) and ligament sprains (IPR = 1.55, 95% CI: 1.16-2.09). CONCLUSIONS: This study describes injury characteristics of high school track and field jumping athletes from 2008 to 2019. We found an overall injury rate of 1.33 injuries per 10,000 AEs. Higher overall rates of jumping-related injuries occurred during competitions than in practice, and female athletes displayed a significantly higher rate of injuries during practices compared to male athletes.

Nonsteroidal Anti-Inflammatory Drug Injections versus Steroid Injections in the Management of Upper and Lower Extremity Orthopedic Conditions: A Systematic Review with Meta-Analysis.

BACKGROUND: Although corticosteroid injections are an effective treatment for musculoskeletal pathologies, they may not be suitable for all patients. The purpose of this systematic review was to compare clinical outcomes between patients who received NSAID and corticosteroid injections for various orthopedic conditions. METHODS: Medline, Embase, Web of Science, and Cochrane Central Register of Controlled Trials were searched, and meta-analyses were performed using a random-effects model for outcomes presented in three or more studies. Other studies were qualitatively analyzed. RESULTS: A total of 28 articles with 2113 patients were included. A meta-analysis of five studies in patients with shoulder impingement syndrome demonstrated that there was no significant difference in the pain visual analogue scale (VAS) between subacromial NSAID injections and corticosteroid injections at 1 month [weighted mean difference (WMD) -0.244; 95% CI, -1.232 to 0.745; I2, 94.5%]. For patients with knee osteoarthritis, a meta-analysis of three studies demonstrated that there was no significant difference between intraarticular NSAID injections and corticosteroid injections in pain VAS at 1 month (WMD 0.754; 95% CI, -0.413 to 1.921; I2, 90.2%) and 3 months (WMD-0.089; 95% CI, -0.345 to 0.166; I2, 0%). A review of the studies assessing pain outcomes for hip osteoarthritis, adhesive capsulitis, and plantar fasciitis showed no significant differences between the NSAID and corticosteroid groups. CONCLUSION: NSAID injections may be safe and effective alternatives to steroid injections, especially in shoulder impingement syndrome and knee osteoarthritis.

Aldosterone Contributes to Vasopressin Escape through Changes in Water and Urea Transport.

Hyponatremia (hypo-osmolality) is a disorder of water homeostasis due to abnormal renal diluting capacity. The body limits the degree to which serum sodium concentration falls through a mechanism called "vasopressin escape". Vasopressin escape is a process that prevents the continuous decrease in serum sodium concentration even under conditions of sustained high plasma vasopressin levels. Previous reports suggest that aldosterone may be involved in the vasopressin escape mechanism. The abilities of aldosterone synthase (Cyp11b2) knockout and wild-type mice to escape from vasopressin were compared. Wild-type mice escaped while the aldosterone synthase knockout mice did not. Both the water channel aquaporin 2 (AQP2) and the urea transporter UT-A1 protein abundances were higher in aldosterone synthase knockout than in wild-type mice at the end of the escape period. Vasopressin escape was also blunted in rats given spironolactone, a mineralocorticoid receptor blocker. Next, the role of the phosphatase, calcineurin (protein phosphatase 2B, PP2B), in vasopressin escape was studied since aldosterone activates calcineurin in rat cortical collecting ducts. Tacrolimus, a calcineurin inhibitor, blunted vasopressin escape in rats compared with the control rats, increased UT-A1, AQP2, and pS256-AQP2, and decreased pS261-AQP2 protein abundances. Our results indicate that aldosterone regulates vasopressin escape through calcineurin-mediated protein changes in UT-A1 and AQP2.

Study Protocol STEREOLAB: Stereotactic Liver Ablation Assisted with Intra-Arterial CT Hepatic Arteriography and Ablation Confirmation Software Assessment.

PURPOSE: This study aims to evaluate the technical efficacy and local tumor progression-free survival (LTPFS) of a standardized workflow for thermal ablation of colorectal liver metastases (CRLM) consisting of CT during hepatic arteriography (CTHA)-based imaging analysis, stereotactic thermal ablation, and computer-based software assessment of ablation margins. MATERIALS AND METHODS: This investigator initiated, single-center, single-arm prospective trial will enroll up to 50 patients (≤ 5 CRLM, Measuring ≤ 5 cm). Procedures will be performed in an angio-CT suite under general anesthesia. The primary objective is to estimate LTPFS with a follow-up of up to 2 years and secondary objectives are analysis of the impact of minimal ablative margins on LTPFS, adverse events, contrast media utilization and radiation exposure, overall oncological outcomes, and anesthesia/procedural time. Adverse events (AE) will be recorded by CTCAE (Common Toxicity Criteria for Adverse Events), and Bayesian optimal phase-2 design will be applied for major intraprocedural AE stop boundaries. The institutional CRLM ablation registry will be used as benchmark for comparative analysis with the historical cohort. DISCUSSION: The STEREOLAB trial will introduce a high-precision and standardized thermal ablation workflow for CRLM consisting of CT during hepatic arteriography imaging, stereotactic guidance, and ablation confirmation. Trial Registration ClinicalTrials.gov identifier: (NCT05361551).

Who is at risk for postdischarge nausea and vomiting after ambulatory surgery?

BACKGROUND: About one in four patients suffers from postoperative nausea and vomiting. Fortunately, risk scores have been developed to better manage this outcome in hospitalized patients, but there is currently no risk score for postdischarge nausea and vomiting (PDNV) in ambulatory surgical patients. METHODS: We conducted a prospective multicenter study of 2,170 adults undergoing general anesthesia at ambulatory surgery centers in the United States from 2007 to 2008. PDNV was assessed from discharge until the end of the second postoperative day. Logistic regression analysis was applied to a development dataset and the area under the receiver operating characteristic curve was calculated in a validation dataset. RESULTS: The overall incidence of PDNV was 37%. Logistic regression analysis of the development dataset (n=1,913) identified five independent predictors (odds ratio; 95% CI): female gender (1.54; 1.22 to 1.94), age less than 50 yr (2.17; 1.75 to 2.69), history of nausea and/or vomiting after previous anesthesia (1.50; 1.19 to 1.88), opioid administration in the postanesthesia care unit (1.93; 1.53 to 2.43), and nausea in the postanesthesia care unit (3.14; 2.44-4.04). In the validation dataset (n=257), zero, one, two, three, four, and five of these factors were associated with a PDNV incidence of 7%, 20%, 28%, 53%, 60%, and 89%, respectively, and an area under the receiver operating characteristic curve of 0.72 (0.69 to 0.73). CONCLUSIONS: PDNV affects a substantial number of patients after ambulatory surgery. We developed and validated a simplified risk score to identify patients who would benefit from long-acting prophylactic antiemetics at discharge from the ambulatory care center.

Combined Angio-CT Systems: A Roadmap Tool for Precision Therapy in Interventional Oncology.

Combined angiography-CT (angio-CT) systems, which combine traditional angiographic imaging with cross-sectional imaging, are a valuable tool for interventional radiology. Although cone-beam CT (CBCT) technology from flat-panel angiography systems has been established as an adjunct cross-sectional imaging tool during interventional procedures, the intrinsic advantages of angio-CT systems concerning superior soft-tissue imaging and contrast resolution, along with operational ease, have sparked renewed interest in their use in interventional oncology procedures. Owing to increases in affordability and usability due to an improved workflow, angio-CT systems have become a viable alternative to stand-alone flat-panel angiographic systems equipped with CBCT. This review aims to provide a comprehensive technical and clinical guide for the use of angio-CT systems in interventional oncology. The basic concepts related to the use of angio-CT systems, including concepts related to workflow setup, imaging characteristics, and acquisition parameters, will be discussed. Additionally, an overview on the clinical applications and the benefits of angio-CT systems in routine therapeutic and palliative interventional oncology procedures will be reviewed. Keywords: Ablation Techniques, CT-Angiography, Interventional-Body, Interventional-MSK, Chemoembolization, Embolization, Radiation Therapy/Oncology, Abdomen/GI, Skeletal-Axial Supplemental material is available for this article. © RSNA, 2021.

Differentiated human adipose-derived stem cells exhibit hepatogenic capability in vitro and in vivo.

The availability of suitable human livers for transplantation falls short of the number of potential patients. In addition, the availability of primary human hepatocytes for cell-therapy and drug development applications is significantly limited; less than 700 livers per year are available for such studies. However, the majority of these organs cannot be utilized due to pathological infections (e.g., HepB, HepC, or HIV) or excessive levels of steatosis. Thus, the number of cells needed for cell therapy applications far exceeds the number of cells available from donated livers. The ability to implant progenitor cell populations that can form liver tissue in situ, or can be differentiated in vitro would be a major advance in current cell-based therapies. In addition, and importantly for this application, the ability to utilize a non-hepatic progenitor cell to mimic hepatocytes in vitro would enable the scale-up production of cells for bioartifical liver assist devices, cell-therapy and drug discovery applications. We demonstrate the feasibility of inducing adipose-derived stromal (ASC) cells to express several features of human hepatocytes such as glycogen storage and expression of liver specific genes. Importantly, we also show that undifferentiated ASCs and ASC-derived hepatic cells engraft robustly into the liver in a mouse model of toxic injury. These data indicate a significant potential for the use of undifferentiated ASCs and ASC-derived hepatic cells as novel and valuable products for cell therapy.

The effect of an anatomically classified procedure on antiemetic administration in the postanesthesia care unit.

BACKGROUND: The effect of the type of surgical procedure on postoperative nausea and vomiting (PONV) rate has been debated in the literature. Our goal in this retrospective database study was to investigate the effect the type of surgical procedure (categorized and compared anatomically) has on antiemetic therapy within 2 h of admission to the postanesthesia care unit (PACU). METHODS: We retrospectively analyzed data for oncology surgeries (n = 18,109), from our automated anesthesia information system database. We classified the types of surgical procedures anatomically into seven categories, with the integumentary musculoskeletal and the superficial surgeries chosen as the referent group. Our analysis included nine other risk factors for each patient, such as gender, smoking status, history of PONV or motion sickness, duration of anesthesia, number of prophylactic antiemetics administered, intraoperative opioids, ketorolac, epidural use, and postoperative opioids. Multivariate logistic regression was used to assess the effect of the type of surgery on antiemetic administration within the first 2 h of PACU admission, while adjusting for the other risk factors. RESULTS: Compared with integumentary musculoskeletal and superficial surgeries, patients undergoing neurological (P < 0.0001), head or neck (P < 0.0001), and abdominal (P < 0.0001) surgeries were administered PACU antiemetic significantly more often, whereas patients undergoing thoracic surgeries were administered PACU antiemetic significantly less often (P = 0.02). Breast or axilla (P = 0.74) and endoscopic (P = 0.28) procedures did not differ from the referent category. Female, nonsmoker, history of PONV or motion sickness, anesthesia duration, and intraoperative and postoperative opioid administration were significantly associated with antiemetic administration during early PACU admission. CONCLUSIONS: Using our automated anesthesia information system database, we found that the type of surgery, when categorized anatomically, was associated with an increased frequency of early PACU antiemetic administration in our population.

Ongoing provision of individual clinician performance data improves practice behavior.

BACKGROUND: Clinical practice guidelines summarize evidence from science and attempt to translate those findings into clinical practice. Pervasive and consistent adoption of these guidelines into daily provider practice has proven slow. METHODS: Using postoperative nausea and vomiting (PONV) prophylaxis guideline compliance as our metric, we compared the effects of continuing medical education (CME) alone (I), CME with a single snapshot of provider compliance (II), and ongoing reporting of provider compliance data without further CME (III). We retrospectively analyzed guideline compliance of 23,279 anesthetics at the University of Texas M.D. Anderson Cancer Center. Compliance was defined as a patient with 1 risk factor for PONV receiving at least 1 antiemetic, 2 risk factors receiving at least 2 antiemetics, and 3 risk factors receiving at least 3 antiemetics. Drugs of the same class were counted as single antiemetic administration. Propofol-based anesthetic techniques were counted as receiving 1 antiemetic. Patients with 0 risk factors for PONV were not included. We estimated the compliance rates for each of the 4 time periods of the study adjusting for multiple observations on the same clinician. Individual performance feedback was given once at 6 months after intervention I coincident with a refresher presentation on PONV (start of intervention II) and on an ongoing quarterly basis during intervention III. RESULTS: Compliance rates were not significantly influenced with CME (intervention I) compared with baseline behavior (54.5% vs 54.4%, P = 0.9140). Significant improvement occurred during the time period when CME was paired with performance data (intervention II) compared with intervention I (59.2% vs 54.4%, P = 0.0002). Further significant improvement occurred when data alone were presented (intervention III) compared with intervention II (65.1% vs 59.2%, P < 0.0001). For patients with 3 risk factors, we saw significant improvement in compliance rates during intervention III (P = 0.0002). In post hoc analysis of overtreatment, the percentage differences between the baseline and time period III decreased as the number of risk factors increased. CONCLUSIONS: We observed the greatest improvement in guideline compliance with ongoing personal performance feedback. Provider feedback can be an effective tool to modify clinical practice but can have unanticipated consequences.

The Cumulative Perioperative Model: Predicting 30-Day Mortality in Abdominal Surgery Cancer Patients.

OBJECTIVES: 1) To develop a cumulative perioperative model (CPM) using the hospital clinical course of abdominal surgery cancer patients that predicts 30 and 90-day mortality risk; 2) To compare the predictive ability of this model to ten existing other models. MATERIALS AND METHODS: We constructed a multivariate logistic regression model of 30 (90)-day mortality, which occurred in 106 (290) of the cases, using 13,877 major abdominal surgical cases performed at the University of Texas MD Anderson Cancer Center from January 2007 to March 2014. The model includes race, starting location (home, inpatient ward, intensive care unit or emergency center), Charlson Comorbidity Index, emergency status, ASA-PS classification, procedure, surgical Apgar score, destination after surgery (hospital ward location) and delayed intensive care unit admit within six days. We computed and compared the model mortality prediction ability (C-statistic) as we accumulated features over time. RESULTS: We were able to predict 30 (90)-day mortality with C-statistics from 0.70 (0.71) initially to 0.87 (0.84) within six days postoperatively. CONCLUSION: We achieved a high level of model discrimination. The CPM enables a continuous cumulative assessment of the patient's mortality risk, which could then be used as a decision support aid regarding patient care and treatment, potentially resulting in improved outcomes, decreased costs and more informed decisions.

Reduced genomic cytosine methylation and defective cellular differentiation in embryonic stem cells lacking CpG binding protein.

Cytosine methylation at CpG dinucleotides is a critical epigenetic modification of mammalian genomes. CpG binding protein (CGBP) exhibits a unique DNA-binding specificity for unmethylated CpG motifs and is essential for early murine development. Embryonic stem cell lines deficient for CGBP were generated to further examine CGBP function. CGBP(-)(/)(-) cells are viable but show an increased rate of apoptosis and are unable to achieve in vitro differentiation following removal of leukemia inhibitory factor from the growth media. Instead, CGBP(-)(/)(-) embryonic stem cells remain undifferentiated as revealed by persistent expression of the pluripotent markers Oct4 and alkaline phosphatase. CGBP(-)(/)(-) cells exhibit a 60 to 80% decrease in global cytosine methylation, including hypo-methylation of repetitive elements, single-copy genes, and imprinted genes. Total DNA methyltransferase activity is reduced by 30 to 60% in CGBP(-)(/)(-) cells, and expression of the maintenance DNA methyltransferase 1 protein is similarly reduced. However, de novo DNA methyltransferase activity is normal. Nearly all aspects of the pleiotropic CGBP(-)(/)(-) phenotype are rescued by introduction of a CGBP expression vector. Hence, CGBP is essential for normal epigenetic modification of the genome by cytosine methylation and for cellular differentiation, consistent with the requirement for CGBP during early mammalian development.

Alcohol exposure alters cell cycle and apoptotic events during early neurulation.

BACKGROUND: Fetal alcohol exposure causes growth deficits, microencephaly, and neurological abnormalities. Although the effects of alcohol on developmental delay and growth-related deficits have been hypothesized, little is understood about how alcohol alters, in particular, the cyclin pathway within the cell cycle, which is critical to proliferation and apoptotic control. In this study, we examined cell cycle proteins pertinent to the G1-S phase transition and apoptosis, to determine if cell cycle misregulation can be attributed to apoptotic induction and growth defects. METHODS: We examined cell cycle regulation during G1 and S-phase, and DNA fragmentation damage, using E14 dorsal root ganglia neural stem cells (DRG-NC), and cultured mouse embryos exposed to 200 and 400 mg/dl ethanol. RESULTS: Alcohol-exposed DRG-NC demonstrated a dose-dependent increase in cells expressing increased cyclin D1 protein, and increased DNA fragmentation. Western blot analysis, using embryos, demonstrated an overexpression of cyclin D1, D2, and E2F1, key G1 to S-phase cell cycle regulatory components, and increases in p53, linking the cell cycle and apoptotic pathways. Bromodeoxyuridine incorporation indicated reduced DNA synthesis and growth in several embryonic regions. Propidium iodide staining demonstrated decreases in DNA content and increases in DNA fragmentation in several embryonic tissues. CONCLUSIONS: This study indicated that retarded growth of DRG-NC and embryos, induced by alcohol, is associated with altered expression of cell cycle and apoptotic proteins and concurrent inhibition of proliferation and increased DNA fragmentation. We suggest that alcohol induces an increase in cyclin D1 expression, premature S-phase entry, and disjointed DNA synthesis with increased apoptosis.

CUL-4A is critical for early embryonic development.

Ubiquitin-mediated degradation targets cell cycle regulators for proteolysis. Much of the ubiquitin pathway's substrate specificity is conferred by E3 ubiquitin ligases, and cullins are core components of some E3s. CUL-4A encodes one of six mammalian cullins and is amplified and/or overexpressed in breast cancer, which suggests a role in regulating cell cycle progression. To examine CUL-4A's physiologic function, we generated a CUL-4A deletion mutation in mice. No viable CUL-4A(-/-) pups and no homozygous mutant embryos as early as 7.5 days postcoitum (dpc) were recovered. However, CUL-4A(-/-) blastocysts are viable, hatch, form an inner cell mass and trophectoderm, and implant (roughly 4.5 dpc), indicating that CUL-4A(-/-) embryos die between 4.5 and 7.5 dpc. Despite 87% similarity between the Cul-4A and Cul-4B cullins, the CUL-4A(-/-) lethal phenotype indicates that CUL-4A has one or more distinct function(s). Surprisingly, 44% fewer heterozygous pups were recovered than expected by Mendelian genetics, indicating that many heterozygous embryos also die during gestation due to haploinsufficiency. Taken together, our findings indicate that appropriate CUL-4A expression is critical for early embryonic development.

Beat to Beat: A Measured Look at the History of Pulse Oximetry.

It can be argued that pulse oximetry is the most important technological advancement ever made in monitoring the well-being and safety of patients undergoing anesthesia. Before its development, the physical appearance of the patient and blood gas analysis were the only methods of assessing hypoxemia in patients. The disadvantages of blood gas analysis are that it is not without pain, complications, and most importantly does not provide continuous, real-time data. Although it has become de rigueur to use pulse oximetry for every anesthetic, the road leading to pulse oximetry began long ago.

Does deep sedation with propofol affect adenoma detection rates in average risk screening colonoscopy exams?

AIM: To determine the effect of sedation with propofol on adenoma detection rate (ADR) and cecal intubation rates (CIR) in average risk screening colonoscopies compared to moderate sedation. METHODS: We conducted a retrospective chart review of 2604 first-time average risk screening colonoscopies performed at MD Anderson Cancer Center from 2010-2013. ADR and CIR were calculated in each sedation group. Multivariable regression analysis was performed to adjust for potential confounders of age and body mass index (BMI). RESULTS: One-third of the exams were done with propofol (n = 874). Overall ADR in the propofol group was significantly higher than moderate sedation (46.3% vs 41.2%, P = 0.01). After adjustment for age and BMI differences, ADR was similar between the groups. CIR was 99% for all exams. The mean cecal insertion time was shorter among propofol patients (6.9 min vs 8.2 min; P < 0.0001). CONCLUSION: Deep sedation with propofol for screening colonoscopy did not significantly improve ADR or CIR in our population of average risk patients. While propofol may allow for safer sedation in certain patients (e.g., with sleep apnea), the overall effect on colonoscopy quality metrics is not significant. Given its increased cost, propofol should be used judiciously and without the implicit expectation of a higher quality screening exam.