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Nathan Goodyear

Intravenous Fluid Use in Athletes - 0 views

  • Treatment of exercise-associated hyponatremia with hypertonic IV infusion to correct plasma sodium levels is also a standard and accepted use of IV fluid infusions
  • athletes who present for medical care with hypernatremia who cannot tolerate oral fluids can benefit from IV fluids
  • Vaporization of sweat accounts for 80% of heat loss in hot, dry atmospheric conditions. This mechanism of water loss is the major contributor for exercise-associated dehydration
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  • The rate of water loss can be quantified through measurement of sweat rate
  • Pre- and postexercise body weight measurements are the most common means to estimate overall water loss but are condition specific
  • It appears that 1% to 2% body weight loss is well tolerated by the exercising athlete
  • Dehydration, defined as greater than 2% loss of body weight, can negatively affect performance
  • In highly trained endurance athletes, plasma volume and sodium serum concentration were preserved despite a 5% body weight loss
  • In Ironman triathletes, dehydration to 5% body weight loss did not correlate with occurrence of medical complications
  • hydration should begin hours prior to exercise, especially if known deficits are present, and fluids should be consumed at a slow, steady rate, with 5 to 7 mL/kg taken 4 hours prior to exercise
  • Sodium concentration did not produce significant changes in the rate of absorption but was primarily dependent on carbohydrate concentration
  • Replacing 150% of body weight loss over 60 minutes has been tolerated without complications
  • IV treatment of severe dehydration (>7% body weight loss), exertional heat illness, nausea, emesis, or diarrhea, and in those who cannot ingest oral fluids for other reasons, is clinically indicated
  • A recent survey of the National Football League teams revealed that 75% (24 of 32) of the teams utilized IV infusion of fluids for prehydration in at least some otherwise healthy individuals
  • In the National Football League, an average of 1.5 L of normal saline was administered approximately 2.5 hours prior to competition
  • after 2 hours of exercise, the rectal temperature was 0.6° higher in the group not receiving IV infusion. Also, stroke volume and cardiac output were 11% to 16% lower in the control group versus the IV infusion group.
  • Recent evidence suggests the etiology of EAMC is related to muscle fatigue and neuronal excitability
  • no correlation between hydration status or electrolyte concentrations with EAMC
  • there may be a subset of muscle cramping that is associated with a loss of both body fluid and sodium
  • Glycerol is the primary agent for oral hyperhydration
  • elevation of plasma volume by 200 to 300 mL via dextran infusion resulted in 15% increase in stroke volume, 4% increase in VO2 max, and an increase in the exercise time to fatigue
  • Neither the tonicity nor mode of hydration resulted in improved speed of rehydration, greater fluid retention, or improved performance
  • There are beneficial anecdotal reports of EAMC treatment in elite and professional-level athletes with IV hydration during the course of an event
  • Plasma volume was better restored during rehydration with IV fluids at preexercise and 5 minutes of exercise. At 15 minutes, there was no difference between IV and oral rehydration
  • More rapid restoration of plasma volume was accomplished in the IV treatment group with no advantages over oral rehydration in physiological strain, heat tolerance, ratings of perceived effort, or thermal sensations
  • No difference was found in exercise time to exhaustion. IV and oral rehydration methods were equally effective. Heart rates were statistically higher in the oral rehydration group through 75 minutes of exercise, and there were higher increases in norepinephrine plasma concentrations
  • No significant differences between the groups were found for time to recovery, number of days with pain, number of days with stiffness, sleep disturbance, fatigue, rectal temperature, and loss of appetite
  • The current data suggest that IV rehydration is faster than oral
  • There may be physiological benefits of decreased heart rate and norepinephrine in athletes rehydrated via IV route
  • Postexercise blood 1 hour and 24 hours showed no differences in circulating myoglobin or creatine kinase
  • The use of IV fluid may be beneficial for a subset of fluid sensitive athletes
  • this should be reserved for high-level athletes with strong histories of symptoms in well-monitored settings.
  • Volume expanders may also be beneficial for some athletes
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    to be read
Nathan Goodyear

Risk factors for progression of brain atrophy in aging - 0 views

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    increasing HgbA1c associated decreasing brain volume in the elderly population.  This decrease in brain volume was found in asymptomatic individuals.  Take home:  poor blood glucose control and increasing glycation of hemoglobin results in brain loss.
Nathan Goodyear

Testosterone and benign prostatic hyperplasia Jarvis TR, Chughtai B, Kaplan SA, - Asian... - 0 views

  • The prevalence of hypogonadism (often defined as serum testosterone < 300 ng dl−1 ) ranges from 6% [10] to as high as 38%
  • The process of BPH, however, continues as men age and despite the fact their serum testosterone decreases
  • Liu et al. [12] demonstrated that in a group of older males (mean age 59.8 years) that there was not a significant correlation of serum testosterone levels (total, free or bioavailable) with either prostate volume or International Prostate Symptom Score (IPSS)
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  • in eugonadal men, studies have demonstrated that the prostate can increase in volume by approximately 12%
  • There seems to be little doubt that the treatment with testosterone of a young hypogonadal male leads to significant growth of the prostate
  • Behre et al. [22] demonstrated increased prostate volume and prostate-specific antigen (PSA) levels in hypogonadal men
  • Most studies, however, have shown no effect of exogenous androgens on PSA or prostate volume for older hypogonadal males
  • They argue that the prostate is relatively insensitive to changes in androgen concentration at normal levels or in mild hypogonadism because the AR is saturated by androgens and therefore maximal androgen-AR binding is achieved. Conversely, the prostate is very sensitive to changes in androgen levels when testosterone is low
  • saturation model
  • visceral obesity (one of the most significant components of metabolic syndrome) is associated with prostate volume and influences prostate growth during TRT.
  • This hypothesis of inflammation induced LUTS is also argued to be a mechanism for improvement of LUTS with PDE5I
  • The concept, therefore, that treatment with TRT of hypogonadal males with metabolic syndrome might lead to improvement/stabilization of their LUTS, appears to be confirmed in recent work by Francomano et al.
  • There was also an improvement in components of the patient's metabolic syndrome (such as BMI, waist circumference, hemoglobin A1c [HbA1c], insulin sensitivity, and lipid profile) as well as inflammatory markers and C-reactive protein.
  • They concluded that TRT was safe in this group of men, and hypothesize that TRT mitigates the pro-inflammatory factors associated with metabolic syndrome.
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    Authors review the literature behind Testosterone and BPH.  The authors highlight the 4 proposed theories behind BPH: Testosterone, Estrogen, inflammation, and metabolic.   The conclusion is mixed: pointing out that no high level of evidence exists on either side of the debate of Testosterone and BPH.
Nathan Goodyear

Central obesity and the aging brain - 0 views

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    This study showed that abdominal obesity was associated with a smaller brain volume. Specifically, a high waist to hip ratio was associated with a 27% reduction in hippocampal volume.
Nathan Goodyear

Association of Mean Platelet Volume With Androgens and Insulin Resistance in Nonobese P... - 0 views

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    Mean Platelet Volume (MPV) is associated with increased cardiovascular disease in some studies.  Hyperandrogenism is associated with increased CVD in women with PCOS. This study found that elevated androgen levels in non obese women with/without PCOS was associated with lower MPV values.  This stands in contrast to other studies. 
Willow O'Donnell

Have The Optimal Precision In Administering Medication - 0 views

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    If you think that you should purchase IV pumps, you should carefully examine the types and specifications of the infusion pumps offered to. Essentially, you could easily differentiate between a large volume and the small volume infusion pump.
Nathan Goodyear

International Journal of Obesity - Late-life obesity is associated with smaller global ... - 0 views

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    Need your brain at its peak performance?  Better lose weight if you are overweight.  Studies show a reduced brain volume and decreased cognitive function in those that are overweight.
Nathan Goodyear

Effects of progesterone administration on infarct volume and functional deficits follow... - 0 views

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    progesterone shown to provide substantial reduction in volume of infarct in rat stroke model.  This is very promising, and with with other studies revealing the same benefit in the human brain, progesterone should become a part of initial treatment in those with acute brain injuries and should be evaluated for those with aging diseases of the brain.
Nathan Goodyear

Long-term treatment with paroxetine increases verbal declarative memory and hippocampal... - 0 views

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    increasing serotonin, in those with PTSD, increases hippocampal volume and memory. In this study, they used Paxil.  Why not just give 5-HTP to raise serotonin?
Nathan Goodyear

Androgens and prostate disease Cooper LA, Page ST - Asian J Androl - 0 views

  • intraprostatic androgens are not concomitantly increased when serum androgen levels are raised.
  • The "saturation model" proposes that the prostate is sensitive to very low concentrations of circulating androgens, but that once maximal AR binding is achieved, which occurs at relatively low concentrations of circulating T, further increases in serum T have little impact
  • men with metastatic prostate cancer given T who had been previously treated with castration had worsening of disease, whereas those without prior castration did not
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  • There is little data to support the withholding of T therapy on the basis of concern for precipitating prostate cancer.
  • Both intervention data and physiology studies point to minimal effects on the prostate gland when serum T levels are increased to the mid-normal range with T therapy
  • an individualized care plan to assess the possible risks and benefits of T therapy for each patient is critical to optimizing the use of androgens in male health.
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    Nice review of the mixed data on Testosterone and Prostate disease. It is clear that Testosterone does not precipitate prostate cancer.  The intraprostatic hormone milieu likely is different than that present in the serum.  No surprise there.  5alpha reductase decreases prostate volume, PSA, and low-grade prostate cancer, but actually increases aggressive prostate cancer. Supraphysiologic doping in young men associated with no increase in prostate disease. PSA no longer to be followed in men < 55.  Mortality rate not changed.  PSA change of 1.4 ng/ml is appropriate for additional prostate evaluation.  Testosterone therapy on average increased 0.5 ng/ml. Still, no mention of aromatase activity in this article.  Why is it that hormone sensitive disease in men is only with regards to androgens and women estrogen.
Nathan Goodyear

The impact of male overweight on semen quality and outcome of assisted reproduction Tho... - 0 views

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    Abstract only. Study in men seeking reproductive assistance found that increasing BMI had no negative impact on sperm concentration, sperm count, motility and seminal volume. 
Nathan Goodyear

Elderly men over 65 years of age with late-onset hypogonadism benefit as much from test... - 0 views

  • The benefits of restoring serum testosterone in men with LOH were not significantly different between men older than 65 years of age and younger men. There were no indications that side effects were more severe in elderly men. The effects on prostate and urinary function and hematocrit were within safe margins.
  • obesity, but also impaired general health, are the more common causes of low testosterone in aging men
  • Severe LOH is associated with substantially higher risks of all-cause and cardiovascular mortality,
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  • advanced age, obesity, a diagnosis of metabolic syndrome, and poor general health status were predictors of LOH
  • Diabetes mellitus was correlated with hypogonadism in most studies
  • coronary heart disease, hypertension, stroke, and peripheral arterial disease did not predict hypogonadism, they did correlate with the incidence of low testosterone
  • LOH can be defined by the presence of at least three sexual symptoms associated with a total testosterone level of less than 11 nmol/L (3.2 ng/mL) and a free testosterone level of less than 220 pmol/L (64 pg/mL)
    • Nathan Goodyear
       
      the European Male Aging study defined low T as total < 320 ng/dl and free < 64 pg/ml.  
  • Mean weight decreased
  • Waist circumference decreased
  • Total cholesterol decreased
  • Low-density lipoprotein decreased
  • Triglycerides decreased
  • High-density lipoprotein (HDL) increased
  • ratio of total cholesterol to HDL improved
  • Prostate volume increased
  • PSA increased
  • The benefits for men older than 65 years of age were compared with those of younger men, and the improvements in body weight, metabolic factors, psychological functioning, and sexual functioning were of the same magnitude in both age groups
  • weight loss was progressive over the 6-year period, effects of testosterone on lipids and on psychological and sexual functioning reached a plateau after approximately 3 years and these effects were sustained
  • Effects of testosterone on hematopoiesis, on the prostate, and on bladder function were not more severe in older men than in younger men
  • observe a mild increase in prostate volume and serum PSA over time, which is a normal finding in aging men. Maybe somewhat surprising, postvoiding residue and the IPSS did not deteriorate with aging but showed a degree of improvement
  • the severity of the metabolic syndrome is associated with the severity of lower urinary tract symptoms
  • The symptoms of the metabolic syndrome improve upon testosterone treatment and testosterone may thus have a favorable effect on lower urinary tract symptoms
  • it seems reasonable to conclude that the risks of testosterone administration to elderly men are not disproportionately higher in elderly men than in younger men.
  • Despite evidence to the contrary, physicians still harbor a wrongful association between testosterone and the development of prostate pathology (prostate cancer and benign prostate hyperplasia)
  • Not surprisingly, the incidence of prostate cancer was higher in older men; however, it was lower than expected in both groups
  • These observations suggest that the incidence of prostate cancer in patients receiving testosterone therapy, both in the younger and in the older group, was not greater than in the general population not receiving testosterone treatment
  • The historical fear that raising testosterone levels will result in more prostate cancer has been dispelled, particularly by the work of Abraham Morgentaler
  • Higher serum testosterone levels fail to show an increased risk of prostate cancer, and supraphysiological testosterone does not increase prostate volume or PSA in healthy men
  • This apparent paradox is explained by the "saturation model,"
  • Recent studies indicate no increased risk of prostate cancer among men with serum testosterone in the therapeutic range
  • In the present observational study, no cases of major adverse cardiovascular events occurred.
  • the benefits of testosterone therapy are fully achieved only by long-term treatment
  • To achieve maximal benefits, good patient adherence is a prerequisite
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    Study finds new difference in Testosterone benefits and/or side effects between men < 65 with low T and men > 65 with low T.
Nathan Goodyear

Intravenous Fluid Use in Athletes - 0 views

  • The current data suggest that IV rehydration is faster than oral
  • There may be physiological benefits of decreased heart rate and norepinephrine in athletes rehydrated via IV route
  • Muscle damage during exercise in the heat was assessed by myoglobin and creatine kinase
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  • Postexercise blood 1 hour and 24 hours showed no differences in circulating myoglobin or creatine kinase
  • IV administration of fluids can rapidly replace plasma volume
  • The rapid increase in plasma volume is transient, and no measureable difference between IV and oral prehydration exists after 15 minutes of exercise
  • The use of IV fluid may be beneficial for a subset of fluid sensitive athletes
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    IV nutrition pre-event, intra-event, and post-event for recovery.
Nathan Goodyear

Exercise-Associated Muscle Cramps - 0 views

  • athletes who develop EAMC often ingest similar amounts of fluid during exercise as do their noncramping counterparts
  • Oral fluid ingestion may be ineffective, and intravenous fluid may provide a faster delivery for athletes suffering from acute EAMC
  • It is interesting that stretching the affected muscle almost immediately relieves EAMC
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  • Stretching, the primary treatment for acute EAMC
  • National Athletic Trainers’ Association recommends that athletes prone to muscle cramping add 0.3 to 0.7 g/L of salt to their drinks to stave off muscle cramps
  • Others have recommended adding higher amounts of sodium (about 3.0 to 6.0 g/L) to sports drinks based on the frequency of EAMC
  • intravenous infusion of fluids removes this delay, and it has been used to aid athletes who develop acute EAMC
  • maintaining hydration and adequate electrolyte levels is a good prevention strategy for individuals susceptible to EAMC
  • Fluid volumes of 1.8 L per hour have been well tolerated by tennis athletes who are susceptible to EAMC
  • Monitoring an athlete’s body weight is an easy method of ensuring adequate fluid replacement and individualizes each athlete’s fluid needs
  • the National Athletic Trainers’ Association and the American College of Sports Medicine recommend a volume of fluid that allows for less than a 2% body weight reduction
  • Endurance training may also serve as an effective means of preventing EAMC by expanding plasma volume and the extracellular fluid compartment15 and delaying neuromuscular fatigue
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    Exercise associated muscle cramps or EAMC is not worked out.  The theories include dehydration, mineral/electrolyte deficiencies, and neuromuscular activity.
Nathan Goodyear

Effects of Transdermal Testosterone Gel or an Aromatase Inhibitor on Prostate Volume in... - 0 views

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    study finds both Testosterone therapy and aromatase inhibition in men > 65 both increase Testosterone levels.  Increase in prostate size was only seen in the Testosterone only group; not in the AI group.  This implicates aromatase activity in the increase in prostate volume.  
Nathan Goodyear

How We Read Oncologic FDG PET/CT | Cancer Imaging | Full Text - 0 views

  • In early PET literature focusing on analysis of solitary pulmonary nodules, some researchers defined malignancy based on a SUVmax threshold of greater than 2.5
  • We contend that SUV analysis has virtually no role in this setting.
  • tumours grow as spheres, whereas inflammatory processes are typically linear
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  • Far more important than the SUVmax is the pattern rather than intensity of metabolic abnormality and the correlative CT findings
  • Descriptively, we define SUV &lt; 5 as “low intensity”, 5–10 as “moderate”, 10–15 as “intense” and &gt;15 as “very intense”
  • Evolving literature suggests that intensity of uptake is an independent prognostic factor and in some tumour subtypes superior to histopathologic characterisation.
  • aerobic glycolysis
  • Our practice of thresholding the grey and colour scale to liver as detailed above results in similar image intensity to a fixed upper SUV threshold of 8 to 10
  • The advantage of using the liver as a reference tissue is also aided by this organ having rather low variability in metabolic activity
  • When the liver is abnormal and cannot be used as a reference organ, we use the default SUV setting of an upper SUV threshold of 8
  • One of the most challenging aspects of oncologic FDG PET/CT review, however, is to recognise all the patterns of metabolic activity that are not malignant and which consequently confound interpretation
  • Many benign and inflammatory processes are also associated with high glycolytic activity
  • Future articles in the “How I Read” series will address the specific details of reading PET/CT in various cancers
  • The intensity of uptake in metastases usually parallels that in the primary site of disease
  • For example, discordant low-grade activity in an enlarged lymph node in the setting of intense uptake in the primary tumour suggests it is unlikely malignant and more likely inflammatory or reactive
  • By CT criteria the enlarged node is ‘pathologic’ but the discordantly low metabolic signature further characterises this is as non-malignant since such a node is not subject to partial volume effects and therefore the intensity of uptake should be similar to the primary site
  • The exception is when the lymph node is centrally necrotic as a small rim of viable tumour is subject to partial volume effects with expectant lower intensity of uptake; integrating the CT morphology is therefore critical to reaching an accurate interpretation
  • Small nodes that are visualised on PET are conversely much more likely to be metastatic as such nodes are subject to partial volume effects.
  • The exception to this rule is tumours with a propensity for tumour heterogeneity at different sites
  • The combination of FDG and a more specific tracer, which visualises the well-differentiated disease can be very useful to characterise this phenomenon
  • “metabolic signature”
  • For the majority of malignant processes, the intensity of metabolic abnormality correlates with degree of aggressiveness or proliferative rate.
  • a negative PET/CT study in a patient with biopsy proven malignancy would be considered false-negative
  • Warburg effect
  • There, however, are a significant minority of tumours that utilise substrates other glucose such as glutamine or fatty acids as a source of the carbon atoms required for growth and proliferation
  • This includes a subset of diffuse gastric adenocarcinomas, signet cell colonic adenocarcinomas and some sarcomas, particularly liposarcoma
  • There may be a role for other radiotracers such as fluorothymidine (FLT) or amino acid substrates in this setting.
  • Some tumours harbour mutations that result in defective aerobic mitochondrial energy metabolism, effectively simulating the Warburg effect
  • patients with hereditary paraganglioma and pheochromocytoma highlight this phenomenon
  • These have intense uptake on FDG PET/CT despite often having low proliferative rate.
  • Uterine fibroids, hepatic adenomas, fibroadenomas of the breast and desmoid tumours are benign or relatively benign lesions that can have quite high FDG-avidity.
  • Metabolic activity switches off rapidly following initiation of therapy
  • Common examples where patients have commenced active therapy but the referrer is requesting “staging” includes hormonal therapy (eg. tamoxifen) in breast cancer, oral capecitabine in colorectal cancer or high dose steroids in Hodgkin’s lymphoma
  • It is therefore critical to perform PET staging before commencement of anti-tumour therapy
  • The potential advantage of routine diagnostic CT is improved anatomic localisation and definition
  • Without intravenous contrast, additional identification of typical oncologic complications such as pulmonary embolism or venous thrombosis cannot be identified
  • If the study is performed as an “interim” restaging study after commencement of therapy but before completion, in order to reach a valid or clinically useful conclusion findings must be interpreted in the context of known changes that occur at a specific timing and type of therapy
  • The most well studied use of interim PET is in Hodgkin’s lymphoma where repeat PET after two cycles of ABVD-chemotherapy provides powerful prognostic information and may improve outcomes by enabling early change of management
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    good read on the PET/CT scan reading.  They mention that tumors are spheres and inflammation is linear, yet inflammation coexists with cancer; hard to simply delineate these on simple terms. I do agree aon the metabolic signature of the PET/CT scan
market reports

North America the leading Gluten Free Products Market - 0 views

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    The global Gluten Free Products Market is projected to reach $6,206.2 million at a CAGR of 10.2% by 2018. North America is the largest market for gluten-free products that held a volume share of 57% in 2012,
market reports

What is Driving the Gluten-Free Products Market - 0 views

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    The global Gluten-Free Products Market is projected to reach $6,206.2 million at a CAGR of 10.2% by 2018. North America is the largest market for gluten-free products that held a volume share of 57% in 2012
Nathan Goodyear

Reliability of hypothalamic-pituitary-adrena... [Eur J Epidemiol. 2011] - PubMed - NCBI - 0 views

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    Study finds salivary cortisol testing is "reliable" measure of chronic cortisol production.  This study found similarity between diurnal cortisol and dexamethasone suppressed cortisol and adrenal gland volume based on literature review.
Nathan Goodyear

Greater Lifetime Pesticide Use Causes Telomere Shortening - 0 views

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    Hard to show causation here, but volume of environmental toxicants associated with shortening of Telomeres.  Mechanism?  Increased free radical induced mitochondrial disruption resulting in relocation of the Telomerase enzyme from the mitochondria to the nuclei.   This has been shown to occur in cancer pathogenesis.
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