Autophagy regulates the release of exercise factors and their beneficial effects on spatial memory recall.

Exercise promotes learning and memory recall as well as rescues cognitive decline associated with aging. The positive effects of exercise are mediated by circulatory factors that predominantly increase Brain Derived Neurotrophic Factor (BDNF) signaling in the hippocampus. Identifying the pathways that regulate the release of the circulatory factors by various tissues during exercise and that mediate hippocampal Mus musculus Bdnf expression will allow us to harness the therapeutic potential of exercise. Here, we report that two weeks of voluntary exercise in male mice activates autophagy in the hippocampus by increasing LC3B protein levels (p = 0.0425) and that autophagy is necessary for exercise-induced spatial learning and memory retention (p < 0.001; exercise + autophagy inhibitor chloroquine CQ versus exercise). We place autophagy downstream of hippocampal BDNF signaling and identify a positive feedback activation between the pathways. We also assess whether the modulation of autophagy outside the nervous system is involved in mediating exercise's effect on learning and memory recall. Indeed, plasma collected from young exercise mice promote spatial learning (p = 0.0446; exercise versus sedentary plasma) and memory retention in aged inactive mice (p = 0.0303; exercise versus sedentary plasma), whereas plasma collected from young exercise mice that received the autophagy inhibitor chloroquine diphosphate failed to do so. We show that the release of exercise factors that reverse the symptoms of aging into the circulation is dependent on the activation of autophagy in young animals. Indeed, we show that the release of the exercise factor, beta-hydroxybutyrate (DBHB), into the circulation, is autophagy-dependent and that DBHB promotes spatial learning and memory formation (p = 0.0005) by inducing hippocampal autophagy (p = 0.0479). These results implicate autophagy in peripheral tissues and in the hippocampus in mediating the effects of exercise on learning and memory recall and identify DBHB as a candidate endogenous exercise factor whose release and positive effects are autophagy-dependent.

Descriptive epidemiology of soft tissue and bone sarcomas in Lebanon.

OBJECTIVES: Most epidemiologic studies on soft tissue sarcomas (STS) and bone sarcomas (BS) are performed in western countries, with few in the Middle East and North Africa region. We describe the epidemiology of sarcomas in Lebanon using the medical records database at the American University of Beirut Medical Center (AUBMC). METHODS: This single-center retrospective cohort study included patients with sarcomas registered in the database between 2015 and 2019. Their charts were reviewed for baseline characteristics, tumor biology and location, treatment modalities, recurrence, metastasis, and death. RESULTS: The cohort included 234 patients with STS and 99 patients with BS. Most tumors were <10 cm in size. The most common subtypes were liposarcoma for STS and osteosarcoma for BS. The most common location of STS was the thigh. The most frequent sites of STS metastasis were the lungs. Histological subtype, smoking status, and tumor size and grade were significant for progression-free survival (PFS) in patients with STS. By multivariable analysis, smoking was significantly associated with poorer PFS in STS. For BS, only tumor grade was significant for PFS. CONCLUSION: The epidemiology of sarcomas at AUBMC is similar to that previously reported. Smoking history was associated with poorer survival in patients with STS.

Longitudinal and abattoir-based surveillance of MERS-CoV in camels in Jordan, 2018-2020.

To generate baseline information to help better understand the antibody kinetics and nasal shedding dynamics of MERS-CoV in camels in Jordan, a longitudinal surveillance study was conducted in two phases; phase 1 was between December, 2018 and January, 2019 and phase 2 between August and December 2020. In each phase, two camel herds were studied. These herds were located in Al-azraq and in Al-ramtha area and were named Al-azraq and Al-ramtha herds, respectively. The same camel herd of Al-zarqa area was sampled in both phases while two different camel herds, one in each phase, were sampled in Al-ramtha area. Blood and nasal swabs were collected from same selected animals in all visits to each herd in both phases. Additionally, nasal swabs and retropharyngeal lymph node tissue samples were collected from sixty-one camels slaughtered at Al-ramtha abattoir during phase 2 to enhance virus isolation opportunities and phylogenetic analysis. All sampled animals from Al-azraq camel herd were either borderline or seropositive on spike 1 based ELISA assay and negative on quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) in both phases. In Al-ramtha camel herds, an unsteady pattern prevailed in animals' seropositivity in both phases and viral RNA was detected in all animals in the end of phase 1 and in one animal during phase 2. For the seroconversion, anti-MERS-CoV spike 1 antibodies were detected in two animals in phase 1 in the first collection only. While, in phase 2, intermittent seroconversion pattern was observed in several samples over time of collections that ended with all animals became seropositive in the last collection (after nineteen days from viral RNA detection). In addition, viral RNA was detected in nasal swabs of 3 slaughtered camels. Phylogenetic analysis of a partial fragment of spike 1 gene sequences of all MERS-CoV isolates clustered together with clade B of MERS-CoV. This cluster contains all MERS-CoV sequences obtained either from camels or human sources in the Arabian Peninsula indicating the continuous circulation of this clade also in Jordan.

Methionine mediates resilience to chronic social defeat stress by epigenetic regulation of NMDA receptor subunit expression.

RATIONALE: Previous studies suggested that methionine (Met) levels are decreased in depressed patients. However, whether the decrease in this amino acid is important for phenotypic behaviors associated with depression has not been deciphered. OBJECTIVE: The response of individuals to chronic stress is variable, with some individuals developing depression and others becoming resilient to stress. In this study, our objective was to examine the effect of Met on susceptibility to stress. METHODS: Male C57BL/6J mice were subjected to daily defeat sessions by a CD1 aggressor, for 10 days. On day 11, the behavior of mice was assessed using social interaction and open-field tests. Mice received Met 4 h before each defeat session. Epigenetic targets were assessed either through real-rime RTPCR or through Western Blots. RESULTS: Met did not modulate anxiety-like behaviors, but rather promoted resilience to chronic stress, rescued social avoidance behaviors and reversed the increase in the cortical expression levels of N-methyl-D-aspartate receptor (NMDAR) subunits. Activating NMDAR activity abolished the ability of Met to promote resilience to stress and to rescue social avoidance behavior, whereas inhibiting NMDAR did not show any synergistic or additive protective effects. Indeed, Met increased the cortical levels of the histone methyltransferase SETDB1, and in turn, the levels of the repressive histone H3 lysine (K9) trimethylation (me3). CONCLUSIONS: Our data indicate that Met rescues susceptibility to stress by inactivating cortical NMDAR activity through an epigenetic mechanism involving histone methylation.

CYR61/CCN1 expression in resected pancreatic ductal adenocarcinoma: A retrospective pilot study of the interaction between the tumors and their surrounding microenvironment.

BACKGROUND: CCN1 is an extracellular matrix-associated protein thought to be implicated in tumor-stromal interaction in several solid tumors. The aim of our pilot study was to evaluate the correlation between CCN1 expression in stromal cells, pancreatic intraepithelial neoplasia (PanIN) and pancreatic ductal adenocarcinoma cells in resected pancreatic ductal adenocarcinoma (PDAC) specimens, and correlate that clinically. METHODS: A total of 42 paraffin-embedded PDAC tumor specimens were stained for CCN1 and evaluated via immunohistochemical (IHC) analysis. Statistical analysis was performed to correlate between CCN1 expression profiles in tumor tissues and clinicopathological parameters of patients. RESULTS: Our results showed CCN1 (CYR61) gene was highly expressed in PDAC tissues relative to other organ specific tumor tissues. Also, moderate and overexpression of CCN1 in PanIN was associated with PanIN grade 3 tissues. A statistically significant association was found between PanIN CCN1 scores on one hand and cancer stage, cancer grade, and CCN1 expression among ductal tumor cells and adjacent stromal cells on the other hand. DISCUSSION: The associations demonstrated suggest that CCN1 might be contributing to a substantial role in the interaction between the pancreatic tumors on one hand and their surrounding microenvironment and their precursors on the other hand; hence, it might serve as a potential therapeutic target for PDAC.

Nicotine induces resilience to chronic social defeat stress in a mouse model of water pipe tobacco exposure by activating BDNF signaling.

The purpose of this study was to investigate how nicotine in the context of water pipe tobacco smoking (WTS) affects depression and anxiety-like behaviors associated with chronic social defeat stress (CSDS). Male C57BL/6 J mice were exposed to WTS or received intraperitoneal injections of nicotine for thirty days then subjected to CSDS for ten days. During CSDS, mice were exposed to WTS or received nicotine injections. The social interaction and open-field tests were used to classify animals as resilient or susceptible to stress and to evaluate their anxiety-like behavior. After behavioral testing, mice continued to be exposed to WTS/nicotine for ten days and their behavior was reexamined. The involvement of brain derived neurotrophic factor signaling in the nicotine-mediated effects was assessed with the tropomyosin receptor kinase B (TRKB) inhibitor, ANA-12. We found that WTS promotes resilience to stress and rescues social avoidance. Even though WTS initially decreased anxiety-like behaviors, prolonged exposure after the completion of CSDS significantly induced anxiety-like behaviors. Finally, we showed that nicotine mediates the effects of WTS only on resilience to stress by increasing BDNF and TRKB levels and signaling. Our results suggest that the pathways mediating resilience to stress and anxiety are distinct and that nicotine mediates the effects of WTS on social behavior, but not anxiety, by activating BDNF signaling. Significance statement: This study reports the positive effect of WTS and nicotine on social behavior. Furthermore, it shows the negative effects of prolonged WTS on anxiety-like behaviors and suggests that these effects are not necessarily mediated by nicotine. Finally, it identifies BDNF/TRKB signaling pathway as a major mediator of the positive effects of nicotine on social interaction. As a result, this work emphasizes the importance of considering the activation status of this signaling pathway when developing smoking cessation strategies.

Branched-chain amino acids mediate resilience to chronic social defeat stress by activating BDNF/TRKB signaling.

How individuals respond to chronic stress varies. Susceptible individuals ultimately develop depression; whereas resilient individuals live normally. In this study, our objective was to examine the effect of branched-chain amino acids (BCAA), commonly used by athletes, on susceptibility to stress. Male C57BL/6 mice were subjected to daily defeat sessions by a CD1 aggressor, for 10 days. On day11, the behavior of mice was assessed using the social interaction test, elevated plus maze and open field. Mice received the BCAA leucine, isoleucine or valine before each defeat session. Furthermore, we examined whether BCAA regulate brain derived neurotrophic factor (BDNF) signaling by using a brain-permeable tropomyosin receptor kinase B (TRKB) inhibitor, ANA-12. We also tested the effect of voluntary exercise and high protein diets on susceptibility to stress. Mice exposed to chronic stress displayed increased susceptibility and social avoidance. BCAA promoted resilience to chronic stress, rescued social avoidance behaviors and increased hippocampal BDNF levels and TRKB activation. Inhibition of TRKB signaling abolished the ability of BCAA to promote resilience to stress and to rescue social avoidance. Interestingly, we found that BCAA activate the exercise-regulated PGC1a/FNDC5 pathway known to induce hippocampal BDNF signaling. Although both voluntary exercise and BCAA promoted resilience to stress, combining them did not yield synergistic effects confirming that they affect similar pathways. We also discovered that high protein diets mimic the effect of BCAA by rescuing social deficits induced by chronic stress and increase Bdnf expression in the hippocampus. Our data indicate that BCAA, exercise and high protein diets rescue susceptibility to stress by activating the hippocampal BDNF/TRKB signaling.

Lactate Mediates the Effects of Exercise on Learning and Memory through SIRT1-Dependent Activation of Hippocampal Brain-Derived Neurotrophic Factor (BDNF).

Exercise promotes learning and memory formation. These effects depend on increases in hippocampal BDNF, a growth factor associated with cognitive improvement and the alleviation of depression symptoms. Identifying molecules that are produced during exercise and that mediate hippocampal Bdnf expression will allow us to harness the therapeutic potential of exercise. Here, we report that an endogenous molecule produced during exercise in male mice induces the Mus musculus Bdnf gene and promotes learning and memory formation. The metabolite lactate, which is released during exercise by the muscles, crosses the blood-brain barrier and induces Bdnf expression and TRKB signaling in the hippocampus. Indeed, we find that lactate-dependent increases in BDNF are associated with improved spatial learning and memory retention. The action of lactate is dependent on the activation of the Sirtuin1 deacetylase. SIRT1 increases the levels of the transcriptional coactivator PGC1a and the secreted molecule FNDC5, known to mediate Bdnf expression. These results reveal an endogenous mechanism to explain how physical exercise leads to the induction of BDNF, and identify lactate as a potential endogenous molecule that may have therapeutic value for CNS diseases in which BDNF signaling is disrupted.SIGNIFICANCE STATEMENT It is established that exercise promotes learning and memory formation and alleviates the symptoms of depression. These effects are mediated through inducing Bdnf expression and signaling in the hippocampus. Understanding how exercise induces Bdnf and identifying the molecules that mediate this induction will allow us to design therapeutic strategies that can mimic the effects of exercise on the brain, especially for patients with CNS disorders characterized by a decrease in Bdnf expression and who cannot exercise because of their conditions. We identify lactate as an endogenous metabolite that is produced during exercise, crosses the blood-brain barrier and promotes hippocampal dependent learning and memory in a BDNF-dependent manner. Our work identifies lactate as a component of the "exercise pill."

Lactate is an antidepressant that mediates resilience to stress by modulating the hippocampal levels and activity of histone deacetylases.

Chronic stress promotes depression in some individuals, but has no effect in others. Susceptible individuals exhibit social avoidance and anxious behavior and ultimately develop depression, whereas resilient individuals live normally. Exercise counteracts the effects of stress. Our objective was to examine whether lactate, a metabolite produced during exercise and known to reproduce specific brain exercise-related changes, promotes resilience to stress and acts as an antidepressant. To determine whether lactate promotes resilience to stress, male C57BL/6 mice experienced daily defeat by a CD-1 aggressor, for 10 days. On the 11th day, mice were subjected to behavioral tests. Mice received lactate before each defeat session. When compared with control mice, mice exposed to stress displayed increased susceptibility, social avoidance and anxiety. Lactate promoted resilience to stress and rescued social avoidance and anxiety by restoring hippocampal class I histone deacetylase (HDAC) levels and activity, specifically HDAC2/3. To determine whether lactate is an antidepressant, mice only received lactate from days 12-25 and a second set of behavioral tests was conducted on day 26. In this paradigm, we examined whether lactate functions by regulating HDACs using co-treatment with CI-994, a brain-permeable class I HDAC inhibitor. When administered after the establishment of depression, lactate behaved as antidepressant. In this paradigm, lactate regulated HDAC5 and not HDAC2/3 levels. On the contrary, HDAC2/3 inhibition was antidepressant-like. This indicates that lactate mimics exercise's effects and rescues susceptibility to stress by modulating HDAC2/3 activity and suggests that HDAC2/3 play opposite roles before and after establishment of susceptibility to stress.

Median Arcuate Ligament Syndrome: A Single-Center Experience with 23 Patients.

BACKGROUND: Median arcuate ligament syndrome (MALS) is a rare entity that occurs when the median arcuate ligament of the diaphragm is low-lying, causing a compression to the underlying celiac trunk. We reviewed the vascular changes associated with MALS in an effort to emphasize the seriousness of this disease and the complications that may result. METHODS: This is a retrospective descriptive analysis of 23 consecutive patients diagnosed with MALS between January 1, 2012 and December 31, 2015 at a tertiary medical center. Computed tomographic (CT) scans, medical records, and patient follow-up were reviewed. RESULTS: The number of patients included herein was 23. The median age was 56 years (17-83). Sixteen patients (69.6%) had a significant arterial collateral circulation. Eleven patients (47.8%) were found to have visceral artery aneurysms; 4 patients (36.4%) bled secondary to aneurysm rupture. All ruptured aneurysms were treated with endovascular approach. The severity of the hemodynamic changes appears to be greater with complete occlusion, CONCLUSIONS: MALS causes pathological hemodynamic changes within the abdominal vasculature. Follow-up is advised for patients who develop a collateral circulation. Resulting aneurysms should preferably be treated when the size ratio approaches three. Treatment of these aneurysms can be done via an endovascular approach coupled with possible celiac artery decompression to restore physiologic blood flow.

Gastro-bronchial fistula after laparoscopic nissen fundoplication.

Gastro-bronchial fistula (GBF) is an unusual complication of Nissen fundoplication, particularly when performed via a transabdominal approach. The mechanism of such fistula is thought to be related to a previously untreated ulcer in the mucosa of the wall of the gastric wrap or to a subclinical injury to the gastric wall during the process of division of the short gastric vessels and gastric mobilization. This process is greatly aided by herniation of the wrap into the chest in the postoperative period, placing the stomach in intimate contact with the bronchial tree. The diagnosis of GBF is often difficult to establish and requires a high index of suspicion. Most investigative studies tend to be unrevealing. Historically, an upper gastrointestinal series was the recommended study of choice in the literature. Newer reports, however, highlight the value and importance of upper endoscopy as a diagnostic tool in this condition. The majority of GBF were reported in the era of transthoracic Nissen fundoplication. The incidence of this complication seems to have markedly decreased after the widespread adoption of the transabdominal approach to the treatment of GERD. We are reporting the second case in the literature of a GBF developing after a laparoscopic Nissen fundoplication in a 28-year-old male patient. This case report should serve to increase awareness of this uncommon complication that should be considered in the differential diagnosis of patients with recurrent pneumonia or refractory hemoptysis after major upper gastrointestinal surgical procedures.

A clinical phase II study of a non-anthracycline sequential combination of cisplatin-vinorelbine followed by docetaxel as first-line treatment in metastatic breast cancer.

BACKGROUND: We tested a sequential combination regimen using cisplatin and vinorelbine (PVn) followed by docetaxel as first-line chemotherapy in a phase II clinical trial in metastatic breast cancer (MBC). PATIENTS AND METHODS: Thirty-five patients were enrolled. Cisplatin 80 mg/m(2) was given on day 1 and vinorelbine 30 mg/m(2) on days 1 and 8 every 3 weeks for 4 cycles. Responding patients received docetaxel 75 mg/m(2) every 21 days for a maximum of 4 cycles. Three patients were excluded from analysis because of death unrelated to treatment. RESULTS: After a median follow-up of 14 months, 32 patients completed the study. The overall response rate was 53.1%. Complete remission was seen in 5 patients (15.6%), partial response in 12 (37.5%), stable disease in 6 (18.75%), and progressive disease in 9 patients (28.1%). Median time to disease progression was 8 months (range 1-24). At 24 months, 12 (37.5%) patients were alive. A total of 183 cycles were administered. Febrile neutropenia was observed in 4 patients (2.2%). Grade II nephrotoxicity occurred in 12 cycles (6.5%) and grade III vomiting in 31/183 cycles (16.9%). DISCUSSION: PVn is a feasible non-anthracycline option as first-line chemotherapy in patients with metastatic breast cancer and has acceptable toxicity. The sequential addition of 4 cycles of docetaxel following 4 cycles of PVn did not improve the overall response rate and results.

Hepatocellular carcinoma in Lebanon: Etiology and prognostic factors associated with short-term survival.

AIM: To study the epidemiology of HCC in Lebanon and prognostic factors predictive of early mortality. METHODS: An observational follow-up cohort study of HCC cases diagnosed over a five-year period was carried out. Multivariate analysis was conducted to identify prognostic factors in comparison to Cancer of the Liver Italian Program (CLIP) score. Multiple variables including the etiology of underlying liver disease, the demographic characteristics of patients, and the severity of liver disease evaluated by the Child-Pugh score were studied. Tumor parameters included the time of diagnosis of HCC, alpha-fetoprotein level, number and size of nodules, presence of portal vein thrombosis, and treatment modalities. Death or loss of follow-up was considered as an end-point event. RESULTS: Ninety-two patients (mean 60.5 +/- 22.3 years) were included. Etiology of underlying disease was hepatitis B, C, and alcohol in 67%, 20%, and 23.5% respectively. Child-Pugh class at diagnosis was A, B, and C in 34.8%, 39.3% and 25.8% respectively. Overall survival was 44.8%, 32.8% and 17.6% at 1, 2 and 3 years respectively (mean F/U 40.2 +/- 23.5 mo). Multivariate analysis identified three predictors of early mortality (< 6 mo): bilirubin > 3.2 mg/dL (P < 0.01), HCC as first presentation of liver disease (P = 0.035), and creatinine > 1 mg/dL (P = 0.017). A score based on these variables outperformed the CLIP score by Cox proportional hazard. ROC curve showed both models to be equivalent and moderately accurate. CONCLUSION: HBV is the leading cause of HCC in Lebanon. Independent predictors of early mortality are elevated bilirubin, creatinine and HCC as first manifestation of disease. Prospective validation of a score based on these clinical parameters in predicting short-term survival is needed.

Successful living-related liver transplantation for familial hypercholesterolemia in the Middle East.

Familial hypercholesterolemia (FH) is an autosomal dominant inherited metabolic disorder resulting in advanced vascular atherosclerosis and premature death, primarily from coronary artery disease. The primary defect is a mutation in the gene encoding for the plasma LDL receptor located on the short arm of chromosome 19. Liver transplantation is currently the most effective method of treating this disorder. Living-related liver transplantation (LRLT) has become an excellent modality for treating children, including those with inherited metabolic diseases. In this paper, we describe the first report of a LRLT for familial hypercholesterolemia and review FH and the role of liver transplantation.

The use and abuse of antibiotics in elective colorectal surgery: the saga continues....

BACKGROUND: The role of antibiotic prophylaxis in preventing post-operative complications in patients undergoing elective colorectal surgery is well established. Despite evidence that a single-dose prophylaxis is sufficient, the duration of antibiotic use in clinical practice is highly variable and surveys have identified persistent patterns of antibiotic abuse in elective colorectal surgery. MATERIALS AND METHODS: We conducted a retrospective review of all patients who underwent elective colorectal surgery between 1998 and 2002 at the American University of Beirut Medical Center. A survey among general surgeons in Lebanon was also performed to investigate the pattern of antibiotic prophylaxis used in such cases. The MEDLINE database (1966-2004) was searched for English-language articles and abstracts on antimicrobial use in elective colorectal surgery. Papers cited in relevant primary articles were also reviewed. Data were extracted and reviewed by all authors. RESULTS: Two hundred and eleven matching patient-records were identified. A triple regimen including metronidazole, ampicillin and an aminoglycoside was the most commonly used preoperative prophylactic method. Patients received post-operative antibiotics for a mean of 6.66+/-2.62 days. The mean duration of post-operative antibiotic prophylaxis used by the interviewed surgeons was 4.31+/-1.08 days. CONCLUSIONS: Our study confirms that even when strong evidence exists, surgeons fail to adhere to antibiotic prophylaxis guidelines. This pattern is not unique to Lebanon but is shared to a large extent by surgeons around the world. Adherence to published guidelines and improved education of surgeons are essential to the delivery of cost-effective medical practice.