bluuebunny/crossref_metadata_2025 huggingface dataset:
Urinary concentrations of physiological markers of intestinal barrier dysfunction do not increase with acute aspirin use (LB749)
Authors: Lambert G. Patrick , Novoa Madeline , Wulff Mary , Lanspa Stephen
Published: June 2021

Previous studies have shown that acute aspirin use causes increased intestinal permeability to ingested permeability probes. The purpose of the present studies was to determine whether acute aspirin use also increases concentrations of urinary physiological markers of intestinal barrier dysfunction. The urinary markers were: 1) D‐lactate (produced by intestinal bacteria; a marker of intestinal barrier dysfunction if increased in the plasma or urine), 2) intestinal fatty acid binding protein (I‐FABP; a marker of small intestinal enterocyte damage), and 3) claudin‐3 (an intestinal tight junction protein). Two studies were conducted and involved ingestion of aspirin (975 mg) or placebo the night before and the morning of an experiment. Eight healthy subjects participated in each study. Six hours after the morning dose of aspirin or placebo, subjects provided a urine sample. In the first study, the urine was assayed for D‐lactate. In the second study, the urine was assayed for I‐FABP and claudin‐3. No significant differences were found between aspirin and placebo experiments for D‐lactate in study 1, or for I‐FABP or claudin‐3 in study 2. These results indicate that urinary concentrations of D‐lactate, I‐FABP, and claudin‐3 do not increase with acute aspirin use.
Pinealectomy alters Cry 1 and Rev‐erbα gene expression in epididymal adipose tissue (LB758)
Authors: Farias Talita , Andreoti Sandra , Lima Fabio
Published: June 2021

Biological rhythms, besides being under melatonin control, are also controlled by genetic mechanisms, which inform to neuronal and peripheral structures about circadian rhythms. Circadian system are driven by a series of interacting clock genes resulting in 24 hour cycles of gene expression. Clock genes may interact with metabolic genes and regulate their transcription, promoting a proper homeostasis. Disturbances in the rhythm of these genes can promote overweight and increased abdominal fat deposition leading to obesity and metabolic syndrome. Thus, the present study aimed to investigate the circadian rhythm of gene expression of clock genes, and, metabolic genes in pinealectomized animals. One month after pinealectomy, pinealectomized (Pinx) and control (Ctl) animals were sacrificed in different zeitgeber times (Zts: 0,4,8,12,16,20,24). Epididymal fat pad was removed and processed for Pparγ, Bmal1, Clock, Cry1 and Rev‐erbα gene expression. These genes were analyzed by quantitative reverse‐transcriptase PCR. Daily curves for clock and metabolic genes were tested with Anova‐one way and Cosinor analysis. Results: a) Cry 1 circadian rhythm was lost in pinealectomized rats (p<0.05); b) Bmal 1 and Clock daily oscillation did not change in the absence of melatonin; c) the expression of Rev‐erbα increased in Pinx rats (p<0.05); e) Pparγ temporal pattern was lost in Pinx rats. Although it was not observed changes in body weight and in epididymal fat depots, it was found significant differences in the gene expression of clock genes Cry1 and Rev‐erbα. Also the Pparγ temporal pattern has been altered in Pinx animals. Since it is already known that changes in the expression of these clock genes are associated with obesity‐related traits, probably the long‐term changes in these genes could be crucial for the development of a disorder of energy metabolism.

Grant Funding Source: Supported by Fapesp
The cessation of regular exercise and dieting causes rapid adiposity rebound and glucose intolerance in young male rats, findings that are abolished by the glucocorticoid receptor antagonist Mifepristone (LB759)
Authors: Teich Trevor , Pivovarov Jacklyn , Beaudry Jacqueline , Hunt Hazel , Belanoff Joseph , Riddell Michael
Published: June 2021

A rapid deterioration of whole‐body insulin sensitivity and visceral fat mass rebound occurs following cessation of regular exercise in humans and rodents. Both dieting and daily exercise have been shown to increase intracellular visceral fat exposure to glucocorticoids (GCs) via up‐regulation of the pre‐receptor enzyme 11β‐hydroxysteroid dehydrogenase type 1 (11β‐HSD1), a phenomenon that may predispose animals to rapid fat rebound. We hypothesized that sustained elevations of GC exposure in visceral fat, upon removal of regular exercise and caloric restriction (CR), may influence this detrimental metabolic response. Thus, we tested the efficacy of Mifepristone, a potent but non‐selective GC receptor antagonist, on limiting adiposity rebound and preserving whole‐body insulin sensitivity following cessation of daily exercise and CR. Using young male Sprague‐Dawley rats, we provided 20g/day of standard rodent chow and access to voluntary running wheels for 3 weeks followed by locking of the wheels and reintroduction to ad libitum feeding either with or without Mifepristone (80 mg/kg/day) via oral gavage for 1 week. Additional Sedentary and Control Runner groups, who were also calorie restricted (20 g/day), were used as pre‐wheel lock comparisons (n= 8‐10 per group). Cessation of daily running and CR resulted in a 6.5‐fold increase in HOMA‐IR and a 2‐fold increase in glucose AUC during an oral glucose tolerance test in Placebo vs. Control Runners (p<0.05). Mifepristone treatment abolished both of these impairments. Mifepristone also attenuated visceral fat mass rebound in epididymal depots by 14% vs. Placebo and significantly reduced perirenal fat mass rebound by 55% vs. Placebo (p<0.05). Control Runners demonstrated a 5‐fold increase in 11β‐HSD1 protein content in epididymal fat vs. Sedentary and a similar increase remained in the Placebo group one week following cessation of exercise and CR vs. Sedentary (p<0.05). Daily Mifepristone significantly reduced 11β‐HSD1 vs. Control Runners and Placebo groups (p<0.05). These findings suggest that elevations in GC action following regular exercise and dieting promote rapid deterioration in metabolic control in healthy organisms and that this deterioration can be inhibited by a GC receptor antagonist.

Grant Funding Source: Supported by NSERC and Corcept Therapeutics
Deep Brain Stimulation of the ventral striatum impairs extinction of morphine place preference (LB76)
Authors: Miranda Janelle , Martinez Freddyson , Rodríguez José , Do Monte Fabricio , Muñiz Oscar , Quirk Gregory , Barreto Jennifer
Published: June 2021

Deep brain stimulation (DBS) is a neurosurgical procedure in which implanted electrodes deliver electrical pulses to specific brain areas to treat movement disorders. Recently, DBS has been used to treat neuropsychiatric conditions such as obsessive‐compulsive disorder, depression and addiction. Addiction, a worldwide relapsing brain disorder, has been suggested as a promising target for the use of DBS in humans. The ventral striatum (VS) a key component of the brain reward circuit has been suggested as a potential DBS target for the treatment of refractory addiction. We recently found in rats that high frequency DBS (HF‐DBS) of the dorsal portion of the ventral striatum (dorsal‐VS) impaired the extinction of morphine‐induced conditioned place preference (CPP). Here, we examined whether HF‐DBS of the ventral region of the VS (ventral‐VS) could reduce the expression of morphine‐CPP and enhance its extinction learning. Since the VS is subdivided into anatomical and functional regions, we expect that HF‐DBS to the ventral‐VS, as opposed to the dorsal‐VS, will facilitate the extinction of morphine‐CPP. Similar to the DBS of the dorsal‐VS, our preliminary data showed that DBS of the ventral‐VS caused a non‐significant trend to impair the extinction of morphine place preference. This was indicated by the high percent of time the rats spent in the morphine‐paired side throughout extinction of the DBS group. These results suggest that ventral striatum DBS may not be a promising target for the treatment of extinction of opioid seeking behaviors.

Grant Funding Source: This work was supported by RCMI Small Grants NIHNCRR (2G12‐RR003051) and NIMHD (8G12‐ MD007600) to JLBE, NIMH Conte Center (P50 MH086400‐Project 4) to GJQ and MBRS‐RISEMSC Fellowship (R25‐GM061838) to FJMR
The role of cytokine activated NFkB and STAT1 pathways in impairment of insulin secretion by cachectic solid Ehrlich carcinoma‐bearing mice. (LB762)
Authors: Violato Natalia , Bosqueiro José Roberto
Published: June 2021

The establishment of systemic inflammation seems to play a pivotal role in cancer cachexia progression, mainly by cytokine presence. However, there are no studies assessing the mechanisms responsible for the alterations in insulin secretion in cancer cachexia or correlating these alterations with inflammation in islet. Considering the importance of insulin secretion to metabolic homeostasis control, to identify mechanisms involved in this process in cachexia became important. Thus, in this study we propose to investigate the effects of the high cytokine levels present in cachectic syndrome in pancreatic islets function using solid Ehrlich carcinoma‐bearing mice and the participation of important inflammatory pathways, notably apoptotic pathways, searching for evidence that could indicate the involvement of islet inflammation in the diminished insulin secretion capacity exhibited by these animals. For that, pancreatic islets isolated from Swiss mice (CTL) and tumor‐bearing mice (SET) with 14 days of tumor inoculation were analyzed to evaluate the expression of proteins belonging to NFκB and STAT1 pathways. We analyzed proteins of IKK complex, JAK 1 and 2, STAT1, PUMA, FAS, c‐Myc, BAX, caspase 3 and 9, PDX‐1, and Bcl‐2. The results showed an increase in the expression of the pro‐apoptotic proteins BAX, c‐Myc, FAS, PUMA, caspase 3 and caspase 9. By the other hand, cachetic animals showed decreased expression of the anti‐apoptotic proteins Bcl‐2 and PDX‐1 indicating a possible increase of pancreatic islets apoptosis. These finds are very important in this scenario and will help us to clarify the mechanisms involved in diminished insulin secretion in cancer cachetic animals.

Grant Funding Source: FAPESP
PI3K signaling pathway in leptin receptor expressing cells is not required for endotoxemia‐induced hypophagia (LB764)
Authors: Borges Beatriz , Garcia‐Galiano David , Elias Lucila , Elias Carol
Published: June 2021

Hypophagia and increased energy expenditure under inflammatory conditions, such as that observed after bacterial lipopolysaccharide (LPS) administration, are associated with leptin secretion and stimulation of JAK2‐STAT3 signaling in the CNS. Anorexic effect of leptin also depends on the activation of PI3K signaling pathway. However, the role of PI3K in the endotoxemia‐induced anorexia remains an open question. To investigate if PI3K in leptin receptor expressing cells has a role in the hypophagia and body weight (BW) loss induced by acute endotoxin treatment, mice expressing Cre‐recombinase driven by Lepr promoter were crossed with mice with loxP‐modified p110α allele (Pi3kca gene) and were treated with LPS (100ug/Kg, ip) (1 LPS). Since long term exposure to endotoxin induces desensitization of hypophagia and an inability of leptin to phosphorylate STAT3, we also tested PI3K role in feeding and BW gain in mice submitted to repeated LPS injections (6 LPS). Single LPS, but not 6 LPS control mice (p110α fl/fl), showed reduced food intake (1 LPS: 1.67 ± 0.18g, 6 LPS: 3.07 ± 0.34g), compared with saline injection (3.83 ± 0.25g). Acute LPS also reduced BW (‐0.97 ± 0.19g), compared with 6 LPS (0.49 ± 0.16g) and saline groups (0.31 ± 0.12g). The hypophagia and BW loss induced by 1 LPS were similar in p110α fl/fl‐LepR cre/cre mice; (1.72 ± 0.28g; ‐0.91 ± 0.14g BW), with no changes in 6 LPS (3.47 ± 0.12g; 0.92 ± 0.09g BW) and saline groups (3.25 ± 0.22g; 0.47 ± 0.18g BW). The data suggest that PI3K in leptin receptor expressing cells is not required for acute LPS induced anorexia and has no effect on food intake and BW gain during long term endotoxemia.

Grant Funding Source: Supported by FAPESP and NIH: HD61539; HD 69702
Low salt intake during pregnancy alters glucose metabolism and DNA methylation in the offspring (LB765)
Authors: Siqueira Flavia , Oliveira Ivone , Furukawa Luzia , Heimann Joel
Published: June 2021

Maternal nutritional alterations during pregnancy are associated with metabolic disorders and the period of pregnancy in which these alterations influence adult offspring remains uncertain. Epigenetic changes are proposed to underlie these disorders. Methods: Twelve‐week‐old female Wistar rats were fed a low‐salt (LS) or normal‐salt (NS) diet during gestation or LS during the first (LS10) or second (LS20) half of gestation. Body weight, blood glucose, insulin (ITT) and glucose (GTT) tolerance tests, HOMA‐IR, gene expression and DNA methylation were mapped in the male offspring. Birth weight was lower in LS20 and LS rats compared with NS and LS10 rats. HOMA‐IR was higher in 12‐week‐old LS compared with NS rats and in 20‐week‐old LS10 compared with NS rats. Serum insulin was higher in 20‐week‐old LS10 rats compared with NS rats. The GTT indicated glucose intolerance only in 12‐ and 20‐week‐old LS rats. Methylation of the Insr, Igf1, Igf1r, Ins1 and Ins2 genes in liver of neonates and in liver, white adipose tissue and muscle in 20‐week‐old offspring were influenced by low‐salt intake during pregnancy. In conclusion low‐salt diet in the second half of pregnancy can result in low birth weights in the offspring. Glucose intolerance observed in adult offspring occurred only if low salt intake was given throughout pregnancy. However, insulin resistance in response to low salt intake during pregnancy is related to the time at which this insult occurs and to the age of the offspring. Alterations in the DNA methylation of Igf1 were observed to be correlated with low birth weight in response to low salt feeding during pregnancy.

Grant Funding Source: Supported by FAPESP and CAPES
Alterations in oral glucose‐stimulated insulin release in neuromedin B receptor knockout mice (LB768)
Authors: Paula Gabriela , Souza Luana , Magalhães Carolina , Bressane Nina , Maravalhas Rebecca , Oliveira Karen , Pazos‐Moura Carmen
Published: June 2021

Neuromedin B (NB) is a bombesin‐like peptide found in gastrointestinal tube and pancreas, among other tissues. It has been proposed that NB has a role in insulin secretion, either by a direct effect in pancreatic cells or acting as modulator of the release of gastrointestinal hormones that are incretins. However the relevance of NB and its receptor to insulin secretion and glucose homeostasis is still unclear. Glucose homeostasis in wild type (WT) and neuromedin B receptor knockout (NBR‐KO) mice was examined by measuring glucose and insulin levels at fasted and after oral glucose load states. Female NBR‐KO exhibited similar fasting basal glucose with a 48.4% lower insulinaemia (p<0.05) and lower HOMA (homeostasis model assessment of insulin resistance) index (50.5% lower, p<0.05). Additionally, they were more tolerant to oral glucose as demonstrated by the 18% lower area under the glucose curve (p<0.05). NBR‐KO mice also showed 45.6% less insulin serum levels than WT mice (p<0.05)15 minutes after an oral glucose load, even though blood glucose rose to similar levels in both groups. Male NBR‐KO mice exhibited a mild phenotype, but they also presented lower insulin serum levels 15 minutes after glucose gavage (26.8% lower, p<0.05). Single injection of NB, one hour previous to the oral glucose administration tended to induce higher serum insulin in WT mice, however the same did not occur in NBR‐KO mice. Collectively, data show that NBR‐KO mice have lower insulin response to oral glucose, together with a better glucose tolerance, suggesting that NB and its receptor are involved in insulin secretion by incretins and also, in insulin sensitivity.

Grant Funding Source: Supported by: FAPERJ, CAPES and CNPq
Rosiglitazone decreases cellular iron status in livers from zdf rats (LB774)
Authors: Johnson Jordan , Smith Drew , Wagner William , Bohman Brad , Wright David , Holloway Graham , Hancock Chad
Published: June 2021

Recent work has linked increased circulating iron and cellular iron status with insulin resistance and type 2 diabetes. An increase in cellular iron is also associated with chronic inflammation. To further explore this association we examined free iron, and proteins important for cellular iron management, in liver tissue from Zucker Diabetic Fatty (ZDF) rats and ZDF rats treated with Rosiglitazone (ZDF ROSI). Rosiglitazone (ROSI) is known to improve insulin sensitivity and has recently been shown to reduce certain inflammatory signals. We hypothesized that ROSI treatment of ZDF rats would cause a reduction in free iron and related changes in proteins involved in cellular iron regulation. Six week old ZDF rats were fed ad libitum a chow diet or a chow diet with 100 mg of ROSI/kg of diet for 6 weeks. The free iron concentration in liver tissue was reduced by 26% ± 4% (p=0.02) in response to ROSI treatment compared to ZDF controls. Ferritin protein levels in ZDF ROSI were significantly reduced by 37% ± 12% (p=.003) compared to ZDF. Iron regulatory protein (IRP) analysis showed a reduction in IRP by 21% ± 7% (p=.03) in ZDF ROSI compared to ZDF Chow. These results are consistent with a potential anti‐inflammatory effect of ROSI treatment on the iron status of liver tissue.
Acute hypoxia induces short term potentiation of mid‐cervical interneuron discharge (LB786)
Authors: Sandhu Milap , Baekey David , Guimond Lauren , Lee Kun‐Ze , Maling Nick , Sanchez Justin , Reier Paul , Fuller David
Published: June 2021

The distribution of respiratory neural drive to phrenic motoneurons appears to be primarily monosynaptic during quiet breathing. Anatomical studies, however, indicate a population of cervical interneurons which is synaptically coupled to the phrenic motor pool. We hypothesize that these cells may be part of the neural substrate which drives plasticity in the phrenic motor system. In this study we used a multi‐electrode array approach to characterize the bursting patterns of cervical interneurons (C3/4) during and following a 4 min period of respiratory stimulation with hypoxia (arterial partial pressure of oxygen ~ 40 mmHg). A total of 95 neurons were recorded from 15 anesthetized, paralyzed, vagotomized and mechanically ventilated adult rats. Interneurons were classified as either phasic (n=13) or tonic (n=82) based on bursting patterns relative to the inspiratory cycle. Based on the hypoxic response, tonic bursting interneurons were classified as 1) excited (n=38), 2) inhibited (n=36), 3) insensitive (n=6) or 4) recruited (n=2). Following hypoxia, 43% of interneurons showed short term potentiation of activity that was manifest by a progressive increase in discharge rate after the acute hypoxic response and a gradual decrease in discharge on termination of hypoxia. Non‐linear regression analyses showed a strong relationship between the baseline firing rate and magnitude of short term potentiation in both the hypoxia‐excited and hypoxia‐inhibited interneurons (P<0.001). In other words, interneurons with a low firing rate during baseline were more likely to show persistent changes in bursting following hypoxia. Our results indicate that hypoxia‐induced plasticity is not limited to phrenic motoneurons but can also be expressed in cervical interneurons.

Grant Funding Source: Supported by Craig H. Neilsen (MS) and NIH 1R01NS080180‐01A1 (DF)
A new method for instantaneous quantification of leg muscle fatigue during cycle ergometry (LB797)
Authors: Coelho Ana , Cannon Daniel , Cao Robert , Ferguson Carrie , Casaburi Richard , Porszasz Janos , Rossiter Harry
Published: June 2021

Quantifying skeletal muscle fatigue (MF) during whole‐body exercise is confounded by the power‐velocity relationship. We reasoned that the relationship between isokinetic power and electromyography (EMG) would be linear, allowing MF to be quantified by deviation from this line. Using a rapid switch from standard (hyperbolic) to isokinetic cycling, we hypothesized that the EMG‐power relationship is: 1) linear and velocity dependent; 2) reproducible; and 3) sufficiently precise to quantify leg MF during exercise. Ten subjects (4 healthy and 6 COPD, GOLD 2/3, 29‐86 yr) repeated 5 s of isokinetic cycling at 50, 70 and 100 rpm from low to maximum effort, to determine baseline right‐leg EMG (of 5 muscles) and power (from crank torque and velocity). The patients also completed incremental exercise to the limit of tolerance, terminated with a maximal 5 s isokinetic effort to quantify MF. The EMG‐power relationship was linear (r² = 0.96±0.03), velocity dependent (p < .01) and reproducible (p > .05; ANCOVA). Mean precision (SEE) was 14±6 W. In COPD, isokinetic power was reduced from 167±64 W to 93±52 W at the limit of tolerance (p < .05) with MF contributing between 8 W and 50 W of the total. Establishing an individual’s isokinetic EMG‐power relationship is a reliable addition to a cardiopulmonary exercise test. EMG, combined with instantaneous hyperbolic‐to‐isokinetic switching ergometry, can quantify leg MF during exercise.

Grant Funding Source: Supported by the Pulmonary Education and Research Foundation
A dismantabled, osseous head of regional presentation CLAY‐ADAMS, in the middle of the 20th century (LB8)
Authors: LE FLOCH‐PRIGENT Patrice , Gillot Jean‐Bernard
Published: June 2021

A dismantabled, osseous head presented the maxillary, mandibular, frontal and temporal regions artificially prepared to expone their different elements. The main vascular elements inside the cranial vault and basis were also represented. The set constituted a very unusual preparation. Several similarities with a dismantabled temporal bone and signed by an american manufacturer : CLAY‐ADAMS allowed to attribute the osseous model to this craftman with a quite certitude. The date of creation was estimated between 1930 and 1960. We acknowledge Mr Alain Piffault and Mrs Domenica Scalisi.
The ultrastructural study of suburothelial unmyelinated nerve profile in women with urinary stress incontinence. (LB80)
Authors: Abtahi Bahareh , Venner Kerrie , Groves Mike , Digesu Alex , Elneil Sohier
Published: June 2021

Objective: The ultrastructure of the nerve profile in women with urinary stress incontinence (USI), who are supposed to have a normal bladder function, is still unknown.

Methods: Bladder biopsy were obtained from 11 patients with USI (Age: 55±13 yrs ) and 4 patients ( Age : 58 ±17 yrs) diagnosed with detrusor overactivity /overactive bladder (DO/OAB). Axonal contents of unmyelinated nerve bundles and schwann cells within the suburothelium were studied using electron microscope.

Results: A total of 175 and 63 axons were counted in USI and OAB/DO groups. The mean number of axons/nerve bundle was higher in USI patients in comparison to OAB/DO patients (4.11 vs. 3.15). 4 out of 63 axons (6.35%) in OAB/DO and 3 out of 175 axons (1.71%) in the USI group did not contain small vesicles. The mean number of axons/ nerve bundle without large dense‐cored vesicles in OAB/DO and USI groups was similar (0.55).

Degenerated axons were interestingly observed in both groups of patients. However, the mean number of the degenerated axons/nerve bundle was nearly twice in OAB/DO group in comparison (figure 1) to the USI group (figure 2) (0.55 vs. 0.31).

Degenerated axons with empty appearance were observed in both groups. These changes were observed in 2 out of 63 axons in patients with OAB/DO and 4 out of 175 in USI patients. The regenerated axonal profile was higher in the USI group (7% vs. 3%). Activated schwann cells were observed in both groups of patients (OAB/DO: 30% vs.USI: 45%). The mean short diameter of the nerve bundle was higher in OAB/DO group in comparison to the USI group (3.41 µm vs 1.54 µm).

Conclusion: This study showed ultrastructural changes and nerve degeneration in patients with USI, which has hitherto not been reported.

The profile of axons

OAB/DO patients (n=4)
USI patients (n=11)

Number of biopsies
4
11

Total number of nerve bundle counted
20
53

Total number of axons counted
63
175

Mean number of axons in a nerve bundle
3.15
4.11

Mean number of vesicles per axon
21.03
15.98

Mean number of large dense‐cored vesicles per axon
1.29
1.24

Mean number of number of mitochondria per axon
0.6
0.7
Running wheel activity is reduced in rat pregnancy (LB801)
Authors: Welshhans Elizabeth , Clarizio Katharine , Murphy Robert , O'Hagan Kathleen
Published: June 2021

Rats provided with cage running wheels engage in daily spontaneous exercise, and this model is used to study the impact of exercise on maternal and fetal outcomes in normal and compromised pregnancies. We hypothesized that exercise volume would decrease during gestation. Cage running wheel revolutions were electronically recorded 24/7 in 5 rats before and through 21 days of gestation. Values are expressed as mean (SD). Pre‐gestation, rats completed 503(262) bouts at 17(3)s per bout at average velocity of 51(21) m/min, accumulating 6.5(2.9) km and 135(75) min per day of exercise, with >90% during lights off. Pregnancy decreased exercise distance [‐63(24)% P<0.02] the first day post breeding via a decrease in total bouts [‐69(15)% P<0.02]. Advancing gestation further suppressed exercise volume with distance and time decreased by 91(7)% at day 14 and 98(3)% by day 21, due to decreased number of bouts [‐93(5%)][all P<0.02]. After day 14 gestation, time and distance per bout also decreased (P<0.01) with a smaller contribution from reduced velocity. Spontaneous exercise volume abruptly decreases during the first week of gestation due to reduction in bout frequency and is minimal during the final week of gestation. The >50% reduction in exercise volume during early pregnancy suggests initiation of an energy conservation strategy.

Grant Funding Source: Supported by Midwestern University
Protein ingestion impairs insulin‐stimulated net muscle carnitine uptake in healthy young men (LB812)
Authors: Shannon Chris , Nixon Aline , Greenhaff Paul , Stephens Francis
Published: June 2021

Carbohydrate ingestion promotes insulin‐mediated muscle carnitine accretion, but the effect of protein ingestion is unknown. Six healthy males (age 24 ± 5 yrs, BMI 23 ± 3 kg/m²) ingested 80g carbohydrate (CHO), 40g whey protein + 40g CHO (PRO), or flavoured water (CON) beverages (500 ml) 1 hr following ingestion of 3g L‐carnitine (0.1% ²H3‐L‐carnitine) on 3 randomised 3‐hr visits. The rate of disposal (Rd) and arterio‐venous (AV) forearm carnitine balance (determined from arterialised‐venous and venous plasma ²H3‐carnitine and carnitine concentrations), and brachial artery blood flow (BAF; Doppler ultrasound) were measured, together with serum insulin concentrations, at baseline and 20 min intervals for 3 hrs. Carnitine Rd at 100 min was 4.4 fold greater in CHO compared to CON (0.3 ± 0.1 vs 0.1 ± 0.1 µmol/min; P<0.05), which coincided with peak serum insulin concentration in CHO (64 ± 10 mU/L). However, despite similar insulin responses in CHO and PRO (3‐hr area under curve [AUC] was 4.6 ± 0.8 and 3.9 ± 0.7 U/L•min, respectively) compared to CON (0.4 ± 0.04 U/L•min; P<0.001) and increases in BAF (15 ± 3 and 12 ± 5%) above CON (P<0.05), net carnitine balance AUC increased in CHO (P<0.01), but not PRO, compared to CON (9.3 ± 4.0 and ‐3.9 ± 5.7 vs ‐1.2 ± 1.5 µmol•min, respectively) over the 2 hrs following beverage ingestion. Carbohydrate stimulates insulin mediated muscle carnitine balance, but protein may antagonise this process.
Incidence of spontaneously occurring elevation of fasting blood glucose and its association with increased sarcopenia and exercise capacity deficit in aging C57BL/6J mice (LB818)
Authors: Harrington W Wallace , Milliken Naphtali , Clifton Lisa , Hagerty Laura , Becherer J. David , Russell Alan , Evans William , Stimpson Stephen
Published: June 2021

We have investigated the changes in skeletal muscle mass and exercise capacity with age, and the incidence and impact on muscle mass and exercise capacity of the spontaneous elevation of fasting blood glucose during old age, in male C57BL/6J mice. In mice ranging in age from 5 to 32 months, gastrocnemius muscle mass decreased significantly (↓27% at 32 months, ↓36% when normalized to body weight; ↓23% at 22 months normalized to body weight) compared to 5 months. In mice ranging in age from 7 to 31 months, exercise capacity (exercise to exhaustion on an incline treadmill protocol, expressed as total work) decreased significantly (↓65% at 31 months (↓23% at 22 months)) compared to 7 months. In 672 mice ranging in age from 18 to 26 months, peak incidence of elevated fasting blood glucose occurred at 21 months, at which age 53% of mice were below 110 mg glucose/dl blood, 33% of mice were between 110 and 140 mg/dl, and 14% were over 140 mg/dl. Comparing groups of 22 month‐old mice with high (>170 mg/dl, n=9) or low (<90 mg/dl, n=11) fasting blood glucose, the high group had significantly less body weight (↓4%), less gastrocnemius muscle weight (↓5%), and less exercise capacity (↓17%). We conclude that elevated fasting blood glucose is associated with increased sarcopenia and decreased exercise capacity in old age mice.
Dietary nitrate increases maximal knee extensor speed and power in healthy men and women (LB820)
Authors: Coggan Andrew , Leibowitz Joshua , Kadkhodayan Ana , Farmer Marsha , Anderson Spearie Catherine , Thomas Deepak , Ramamurthy Sujata , Peterson Linda
Published: June 2021

Nitric oxide (NO) has been demonstrated to enhance the maximal shortening velocity and maximal power of rodent muscle. Dietary nitrate (NO3‐) intake has been demonstrated to increase NO bioavailability in humans. We therefore hypothesized that acute dietary NO3‐ intake (in the form of a concentrated beetroot juice (BRJ) supplement) would improve muscle speed and power in humans. To test this hypothesis, healthy men and women (n=8; age=34±9 y) were studied using a randomized, double‐blind, placebo‐controlled crossover design. After an overnight fast, subjects ingested 140 mL of BRJ either containing or devoid of 11.2 mmol of NO3‐. After 2 h, knee extensor speed and power were assessed using a Biodex 4 isokinetic dynamometer. Breath NO levels were also measured periodically using a Niox Mino analyzer as a biomarker of whole‐body NO production. No significant changes in breath NO were observed in the placebo trial, whereas breath NO rose by 66±25% (P<0.05) after dietary NO3‐ intake. This was accompanied by a 5±2% (P<0.05) increase in muscle torque (force) production at the highest angular velocity tested (i.e., 6.28 rad/s). Calculated maximal knee extensor power therefore tended to be greater (i.e., 7.81±0.84 vs. 7.36±0.74 W/kg; P=0.08) and occurred at a higher angular velocity (i.e., 7.00±0.36 vs. 6.31±0.26 rad/s; P<0.05) after dietary NO3 intake. We conclude that acute dietary NO3‐ intake increases whole‐body NO production and muscle speed and power in healthy men and women. This improvement in muscle function may be of relevance in both athletic and clinical populations.

Grant Funding Source: Supported by Washington University Mentors in Medicine, Barnes‐Jewish Hospital Foundation, and ICTS UL1 TR000448
A simplified model of valveless pumping in avian lungs (LB824)
Authors: Harvey Emily , Ben‐Tal Alona
Published: June 2021

Birds have a remarkable respiratory system in which air flows unidirectionally through rigid lungs. This unique structure enables birds to utilize oxygen at a much higher rate than is possible in mammals, and allows them to cope with much lower atmospheric pressure and oxygen levels. However, the dynamics leading to this unidirectional flow are poorly understood. We construct a phenomenological one‐dimensional model of flow in a closed loop with a single pumping source. The complex anatomical structure of the avian respiratory system is represented in our model using varying compliances and resistances to flow. This leads to a simplified model of air flow in avian lungs. Using our model, we investigate conditions under which unidirectional flow is generated, and demonstrate that the anatomically determined parameters are important in determining the direction and magnitude of a net flow. We then incorporate the effect of a second pumping source, in order to represent both the caudal and cranial air sacs.

Grant Funding Source: NIH grant R01 NS069220
Association of myelin oligodendrocyte glycoprotein with vitamin D inhibited Experimental autoimmune encephalomyelitis development (LB826)
Authors: Chiuso‐Minicucci Fernanda , Ishikawa Larissa , Mimura Luiza , Silva Thais , Zorzella‐Pezavento Sofia , França Thais , Marques Camila , Ikoma Maura , Okoshi Marina , Sartori Alexandrina
Published: June 2021

Experimental autoimmune encephalomyelitis (EAE) is a murine model of multiple sclerosis (MS). Current MS treatment consists in general suppression of immune response which increases susceptibility to infections. Considering the immunomodulatory properties and tolerogenic effects of active vitamin D, this study aimed to evaluate the therapeutic effect of myelin oligodendrocyte glycoprotein (MOG) associated with vitamin D in EAE development. Female C57BL/6 mice were submitted to EAE induction by immunization with MOG emulsified with Complete Freund Adjuvant plus Mycobacterium tuberculosis. Two intraperitoneal doses of Bordetella pertussis toxin were also injected. One day after immunization, mice were treated with 0,1mug of vitamin D every other day during 15 days (on days 1, 3, 5, 7, 9, 11, 13 and 15). MOG (150mug) was co‐administered on days 3 and 11. The administration of vitamin D or MOG alone determined significant reduction in EAE incidence and in clinical scores. When MOG was associated with vitamin D the animals (n=12) did not develop clinical disease. In this group there was also a decreased production of IL‐17 and IL‐6 by spleen and CNS mononuclear inﬁltrating cells stimulated with MOG, in comparison to the EAE control. In addition, this treatment inhibited dendritic cells (CD11c+MHC‐II+CD86+) maturation in the spleen. In conclusion, the association of MOG with vitamin D was able to control EAE development.

Grant Funding Source: FAPESP
Assessment of Ethanol Induction of Breast Cancer Metastasis: the Involvement of ErbB2 and Endoplasmic Reticulum (ER) Stress (LB833)
Authors: Pan Daniel , Xu Mei , Luo Jia
Published: June 2021

Ethanol consumption is a risk factor for the development of breast cancer and a possible promoter of breast cancer metastasis. However, the mechanisms of oncogenic action are still unknown. Previous studies have shown that breast cancer cells over‐expressing ErbB2 have been more susceptible to ethanol‐induced invasion and migration and that ER stress also promotes tumor metastasis. The objective of this study is to determine whether ethanol exposure may activate ErbB2 and induce ER stress in breast cancer cells. In this study, we test this hypothesis by examining the effect of ethanol on the activation of ErbB2 and eIF2α/PKR. The enhanced phosphorylation of eIF2α and PKR are considered indicators of ER stress. MCF7 human breast cancer cells were treated with or without ethanol for 20 days. The results indicated that phosphorylated ErbB2 was increased by a factor of 1.4 in cells treated with 0.1% ethanol and by a factor of 1.2 for cells treated with 0.2% ethanol when compared to the untreated control. Also, phosphorylated eIF2α was shown to have a 1.3 and 1.2 fold increase in 0.1% and 0.2% ethanol, respectively, while phospho‐PKR was shown to have a 1.7 and 1.5 fold increase for 0.1% and 0.2% ethanol, respectively. These findings suggest that ethanol can activate ErbB2 and induce ER stress in breast cancer cells, which may result in increased metastasis. This study was supported by NIH grant (AA017226).

Grant Funding Source: Supported by NIH grant (AA017226)
Expression changes of histone deacetylases in dexamethasone‐induced neurotoxicity in human neuroblastoma SH‐SY5Y cells (LB849)
Authors: Lee Gyuhwi , Park Yoon Jung
Published: June 2021

Chronic stress induces an abnormal increase in glucocorticoids level, which is related with neurodegenerative conditions and mood disorders. Histone deacetylase(HDAC) inhibitors have been suggested to have a promising therapeutic potential for those conditions. However, it is not clear whether HDAC is directly involved in the reverse of glucocorticoid‐mediated stress. We investigated changes of HDAC expression in response to treatment of dexamethasone(Dex), a synthetic glucocorticoid in human neuroblastoma SH‐SY5Y cells. Dex treatment affects cell viability even with 1uM. The stress induction was confirmed with stress‐response genes in neurons such as norepinephrine transporter and monoamine oxidase‐A, which increased in 4.2 and 5.1 folds, respectively. Various HDAC mRNA levels were profiled upon Dex treatment. While expression of HDAC1, 6, and 8 were not changed, HDAC4 and HDAC9 were significantly overexpressed in 1.8 and 2.1 folds, respectively. The direct changes of specific HDACs in reponse to Dex‐induced stress might suggest a potential mechanism by which chronic stress leads to neurodegenerative conditions.

Grant Funding Source: supported by Korean NRF ( 22A20130012143)
Maltase Glucoamylase (MGAM): Putting Diabetes in its Place! (LB85)
Authors: Burwash Andrew , Eid‐Ricci Alessandro , Muradia Priya , Ero Adesuwa , Dolganow Alexandra , Liu Iris , Wall Susan , Sim Lyann
Published: June 2021

By 2050 1 in 3 Americans will have type 2 diabetes, a disease characterized by excessively high blood glucose levels. Typically, diabetes is treated with regular insulin injections and blood sugar monitoring. For centuries, Aryuvedic medicine has had a massive following, in part due to its natural remedies for diabetes deriving from an Indian herb, Salacia reticulata. These extracts were found to contain α‐glucosidase inhibitors, a class of anti‐diabetic drugs that competitively inhibit intestinal starch‐digesting enzymes such as human Maltase Glucoamylase (MGAM). As MGAM is responsible for catalyzing the final glucose‐releasing step of starch digestion, inhibiting MGAM would delay glucose absorption into the bloodstream. The Ashbury SMART (Students Modeling a Research Topic) Team modeled MGAM in complex with two inhibitors, salacinol and Acarbose, (PDBID 2QMJ & 3L4Z) using Jmol and 3D printing technology. The binding of ‐glucosidase inhibitor salacinol, derived from Salacia reticulata extracts and Acarbose, a currently prescribed α‐glucosidase inhibitor will be compared in the MGAM active site. Notably, both inhibitors interact with MGAM residues Asp327 and His600 through ring hydroxyl groups, however salacinol contributes additional electrostatic interaction between its sulfonium center and the catalytic nucleophile Asp443.

Grant Funding Source: Supported by grants from the NIH‐SEPA and NIH‐CTSA.
Assay Modifications to a Streptococcal Pharyngitis Rapid Lateral Flow Test for Mobile Health Applications (LB854)
Authors: Federico Niksha , Federico Francesca , Sternik Gabriel , Esmaeli‐Azad Babak
Published: June 2021

Streptococcal tonsillitis, streptococcal pharyngitis,or streptococcal sore throat (known commonly as strep throat) is a type of pharyngitis caused by a group A streptococcal infection. It affects the pharynx including the tonsils and possibly the larynx. Common symptoms include fever, sore throat, and enlarged lymph nodes. It is the cause of 37% of sore throats among children and 5‐15% in adults.

Strep throat is contagious, typically spread via close contact with an infected individual. A preliminary diagnosis is made based on the results of a rapid lateral flow test. A follow up definitive diagnosis is made based on the results of a throat culture. However, these tests are not always needed as diagnosis for administration of treatment may also be made by a physician based on the symptoms.

We have previously developed a wireless mobile health application for diagnosis of streptococcal pharyngitis using a smart phone enabled avatar system which uses medical algorithms for diagnosis of this disease, taking advantage of the standard questions and answers typically used by physicians in practice. To further provide confirmation testing of this analysis system, we here describe customization, refinements, and modifications to assay procedures and chemical components of an FDA approved lateral flow rapid diagnostic test for Streptococcal Pharyngitis with a focus on mobile health applications. Specifics of our findings can be applied to other lateral flow assays currently in use for confirmatory tests of other diseases.
Multiple United States Medical Licensing Examination Attempts and the Estimated Risk of Disciplinary Actions Among Graduates of U.S. and Canadian Medical Schools
Authors: Arnhart Katie L. , Cuddy Monica M. , Johnson David , Barone Michael A. , Young Aaron
Published: June 2021

Purpose

The United States Medical Licensing Examination (USMLE) recently announced 2 policy changes: shifting from numeric score reporting on the Step 1 examination to pass/fail reporting and limiting examinees to 4 attempts for each Step component. In light of these policies, exam measures other than scores, such as the number of examination attempts, are of interest. Attempt limit policies are intended to ensure minimum standards of physician competency, yet little research has explored how Step attempts relate to physician practice outcomes. This study examined the relationship between USMLE attempts and the likelihood of receiving disciplinary actions from state medical boards.

Method

The sample population was 219,018 graduates from U.S. and Canadian MD-granting medical schools who passed all USMLE Step examinations by 2011 and obtained a medical license in the United States, using data from the NBME and the Federation of State Medical Boards. Logistic regressions estimated how attempts on Steps 1, 2 Clinical Knowledge (CK), and 3 examinations influenced the likelihood of receiving disciplinary actions by 2018, while accounting for physician characteristics.

Results

A total of 3,399 physicians (2%) received at least 1 disciplinary action. Additional attempts needed to pass Steps 1, 2 CK, and 3 were associated with an increased likelihood of receiving disciplinary actions (odds ratio [OR]: 1.07, 95% confidence interval [CI]: 1.01, 1.13; OR: 1.09, 95% CI: 1.03, 1.16; OR: 1.11, 95% CI: 1.04, 1.17, respectively), after accounting for other factors.

Conclusions

Physicians who took multiple attempts to pass Steps 1, 2 CK, and 3 were associated with higher estimated likelihood of receiving disciplinary actions. This study offers support for licensure and practice standards to account for physicians’ USMLE attempts. The relatively small effect sizes, however, caution policy makers from placing sole emphasis on this relationship.
Not Frail and Elderly: How Invasive Can We Go in This Different Type of Adult Spinal Deformity Patient?
Authors: Passias Peter G. , Pierce Katherine E. , Passfall Lara , Adenwalla Ammar , Naessig Sara , Ahmad Waleed , Krol Oscar , Kummer Nicholas A. , O’Malley Nicholas , Maglaras Constance , O’Connell Brooke , Vira Shaleen , Schwab Frank J. , Errico Thomas J. , Diebo Bassel G. , Janjua Burhan , Raman Tina , Buckland Aaron J. , Lafage Renaud , Protopsaltis Themistocles , Lafage Virginie
Published: June 2021

Study Design.

Retrospective review of a single-center spine database.

Objective.

Investigate the intersections of chronological age and physiological age via frailty to determine the influence of surgical invasiveness on patient outcomes

Summary of Background Data.

Frailty is a well-established factor in preoperative risk stratification and prediction of postoperative outcomes. The surgical profile of operative patients with adult spinal deformity (ASD) who present as elderly and not frail (NF) has yet to be investigated. Our aim was to examine the surgical profile and outcomes of patients with ASD who were NF and elderly.

Methods.

Patients with ASD 18 years or older, four or greater levels fused, with baseline (BL) and follow-up data were included. Patients were categorized by ASD frailty index: NF, Frail (F), severely frail (SF]. An elderly patient was defined as 70 years or older. Patients were grouped into NF/elderly and F/elderly. SRS-Schwab modifiers were assessed at BL and 1 year (0, +, ++). Logistic regression analysis assessed the relationship between increasing invasiveness, no reoperations, or major complications, and improvement in SRS-Schwab modifiers [Good Outcome]. Decision tree analysis assessed thresholds for an invasiveness risk/benefit cutoff point.

Results.

A total of 598 patients with ASD included (55.3 yr, 59.7% F, 28.3 kg/m2). 29.8% of patients were older than 70 years. At BL, 51.3% of patients were NF, 37.5% F, and 11.2% SF. Sixty-sis (11%) patients were NF and elderly. About 24.2% of NF-elderly patients improved in SRS-Schwab by 1 year and had no reoperation or complication postoperatively. Binary regression analysis found a relationship between worsening SRS-Schwab, postop complication, and reoperation with invasiveness score (odds ratio: 1.056 [1.01–1.102], P = 0.011). Risk/benefit cut-off was 10 (P = 0.004). Patients below this threshold were 7.9 (2.2–28.4) times more likely to have a Good Outcome. 156 patients were elderly and F/SF with 16.7% having good outcome, with a risk/benefit cut-off point of less than 8 (4.4 [2.2–9.0], P < 0.001).

Conclusion.

Frailty status impacted the balance of surgical invasiveness relative to operative risk in an inverse manner, whereas the opposite was seen amongst elderly patients with a frailty status less than their chronologic age. Surgeons should perhaps consider incorporation of frailty status over age status when determining realignment plans in patients of advanced age.

Level of Evidence: 3
Conduction Disturbances and Permanent Pacemaker Implantation After Transcatheter Aortic Valve Replacement: Predictors and Prevention
Authors: Tsoi Melissa , Tandon Kanul , Zimetbaum Peter J. , Frishman William H.
Published: June 2021

Conduction disturbances and permanent pacemaker implantation (PPMI) remain a frequent and important consequence of transcatheter aortic valve replacement (TAVR). Understanding risk factors for TAVR-related conduction disturbances could improve patient selection, procedural techniques, and periprocedural efforts for monitoring and treatment of heart block. Several studies have identified patient-related and procedural factors associated with new-onset left bundle branch block, high-degree atrioventricular block, and the need for PPMI after TAVR. Notable patient-related predictors include preexisting right bundle branch block, membranous septal length, and calcification of the left ventricular outflow tract. Modifiable procedural predictors include device implantation depth, prosthesis oversizing, and valve type. This review aims to summarize the current literature examining predictors of conduction disturbances and PPMI after TAVR, particularly with regard to the newer-generation valve types. We also propose a management algorithm for the management of conduction disturbances postprocedure.