Synthesis of Quantum Dot-Tagged Submicrometer Polystyrene Particles by Miniemulsion Polymerization

Nancy Joumaa,M. Lansalot,A. Theretz,A. Elaissan,A. Sukhanova,M. Artemyev,I. Nabiev,J.H.M. Cohen 한국고분자학회 2006 한국고분자학회 학술대회 연구논문 초록집 Vol.2006 No.10

A high-whey-protein diet does not enhance mechanical and structural remodeling of cardiac muscle in response to aerobic exercise in rats

Kevin Boldt,Venus Joumaa,Jeannine Turnbull,Paul W.M. Fedak,Walter Herzog 한국운동영양학회 2022 Physical Activity and Nutrition (Phys Act Nutr) Vol.26 No.1

[Purpose] Aerobic exercise training results in distinct structural and mechanical myocardial adaptations. In skeletal muscle, whey protein supplementation is effective in enhancing muscle adaptation following resistance exercise. However, it is unclear whether cardiac adaptation to aerobic exercise can be enhanced by systematic protein supplementation. [Methods] Twelve-week-old rats were assigned to 12 weeks of either sedentary or aerobic exercise with either a standard (Sed+Standard, Ex+Standard) or high-protein (Sed+Pro, Ex+Pro) diet. Echocardiography was used to measure cardiac structural remodeling and performance. Skinned cardiac fiber bundles were used to determine the active and passive stress properties, maximum shortening velocity, and calcium sensitivity. [Results] Aerobic training was characterized structurally by increases in ventricle volume (Ex+Standard, 19%; Ex+Pro, 29%) and myocardial thickness (Ex+Standard, 26%; Ex+Pro, 12%) compared to that of baseline. Skinned trabecular fiber bundles also had a greater unloaded shortening velocity (Sed+Standard, 1.04±0.05; Sed+Pro, 1.07±0.03; Ex+Standard, 1.16±0.04; Ex+Pro, 1.18±0.05 FL/s) and calcium sensitivity (pCa50: Sed+Standard, 6.04±0.17; Sed+Pro, 6.08±0.19; Ex+Standard, 6.30±0.09; Ex+Pro, 6.36±0.12) in trained hearts compared to that of hearts from sedentary animals. However, the addition of a high-protein diet did not provide additional benefits to either the structural or mechanical adaptations of the myocardium. [Conclusion] Therefore, it seems that a high-whey-protein diet does not significantly enhance adaptations of the heart to aerobic exercise in comparison to that of a standard diet.

Consumption of a high-fat-high-sucrose diet partly diminishes mechanical and structural adaptations of cardiac muscle following resistance training

Kevin Boldt,Stela Mattiello,Venus Joumaa,Jeannine Turnbull,Paul W.M. Fedak,Walter Herzog 한국운동영양학회 2021 Physical Activity and Nutrition (Phys Act Nutr) Vol.25 No.2

[Purpose] The purpose of this study was to investigate the effects of a high-fat high-sucrose (HFHS) diet on previously reported adaptations of cardiac morphological and contractile properties to resistance training. [Methods] Twelve-week-old rats participated in 12-weeks of resistance exercise training and consumed an HFHS diet. Echocardiography and skinned cardiac muscle fiber bundle testing were performed to determine the structural and mechanical adaptations. [Results] Compared to chow-fed sedentary animals, both HFHS- and chow-fed resistance-trained animals had thicker left ventricular walls. Isolated trabecular fiber bundles from chow-fed resistance-trained animals had greater force output, shortening velocities, and calcium sensitivities than those of chow-fed sedentary controls. However, trabeculae from the HFHS resistance-trained animals had greater force output but no change in unloaded shortening velocity or calcium sensitivity than those of the chow-fed sedentary group animals. [Conclusion] Resistance exercise training led to positive structural and mechanical adaptations of the heart, which were partly offset by the HFHS diet.

Surveillance Study of Acute Gastroenteritis Etiologies in Hospitalized Children in South Lebanon (SAGE study)

Ghassan Ghssein,Ali Salami,Lamis Salloum,Pia Chedid,Wissam H Joumaa,Hadi Fakih 대한소아소화기영양학회 2018 Pediatric gastroenterology, hepatology & nutrition Vol.21 No.3

Purpose: Acute gastroenteritis (AGE) is a major cause of morbidity and remains a major cause of hospitalization. Following the Syrian refugee crisis and insufficient clean water in the region, this study reviews the etiological and epidemiological data in Lebanon.Methods: We prospectively analyzed demographic, clinical and routine laboratory data of 198 children from the age of 1 month to 10 years old who were admitted with the diagnosis of AGE to a private tertiary care hospital located in the district of Nabatieh in south Lebanon.Results: Males had a higher incidence of AGE (57.1%). Pathogens were detected in 57.6% (n=114) of admitted pa-tients, among them single pathogens were found in 51.0% (n=101) of cases that consisted of: Entamoeba histolytica26.3% (n=52), rotavirus 18.7% (n=37), adenovirus 6.1% (n=12) and mixed co-pathogens found in 6.6% (n=13). Breast-fed children were significantly less prone to rotavirus (p=0.041). Moreover, children who had received the rota-virus vaccine were significantly less prone to rotavirus (p=0.032).Conclusion: Our findings highlight the high prevalence of E. histolytica infection as the major cause of pediatric gastro-enteritis in hospitalized children, during the summer period likely reflecting the insanitary water supplies and lack of hygiene. Moreover the 42.4% of unidentified causative pathogens should prompt us to widen our diagnostic laboratory arsenal by adopting new diagnostic technologies.

Prevalence, Laboratory Findings and Clinical Characteristics of Campylobacteriosis Agents among Hospitalized Children with Acute Gastroenteritis in Lebanon

Ghssein, Ghassan,Awada, Rana,Salami, Ali,Bahmad, Hisham F.,Awad, Ali,Joumaa, Wissam H.,Roz, Ali El The Korean Society of Pediatric Gastroenterology 2021 Pediatric gastroenterology, hepatology & nutrition Vol.24 No.4

Purpose: Campylobacter species are currently the most common cause of bacterial gastroenteritis. In Lebanon, Campylobacter infection occurrence is underdiagnosed owing to the lack of specific culture and rapid test kits, particularly among children. This study aimed to evaluate the prevalence, laboratory findings, and clinical characteristics of Campylobacter infection in hospitalized children with acute gastroenteritis in South Lebanon. Methods: We conducted a 6-month retrospective cohort study between January and June 2018, including 291 children aged between 1 month and 12 years, who were admitted to a tertiary healthcare center in South Lebanon. The medical files of the patients were reviewed to retrieve the required clinical information, including clinical and laboratory data. Results: The prevalence of campylobacteriosis agents in pediatric patients with acute gastroenteritis is 12.02%. Patients infected with Campylobacter had more severe acute gastroenteritis than Campylobacter-negative patients and often presented with high-grade fever, diarrhea episodes more than six times per day, diarrhea lasting for more than five days, and dehydration. Indeed, children with high-grade fever (≥38.5℃) were five times more likely to test positive for Campylobacter than those with low-grade fever. In addition, the results showed a higher Vesikari score for the majority of Campylobacter-positive patients with severe acute gastroenteritis compared to a moderate profile for Campylobacter-negative patients. Conclusion: The present study findings highlight that Campylobacter infection is frequent among children with acute gastroenteritis. Therefore, the detection of Campylobacter should be carried out for the diagnosis of human gastroenteritis in Lebanon, along with the detection of routine enteropathogens.

Surveillance Study of Acute Gastroenteritis Etiologies in Hospitalized Children in South Lebanon (SAGE study)

Ghssein, Ghassan,Salami, Ali,Salloum, Lamis,Chedid, Pia,Joumaa, Wissam H,Fakih, Hadi The Korean Society of Pediatric Gastroenterology 2018 Pediatric gastroenterology, hepatology & nutrition Vol.21 No.3

Purpose: Acute gastroenteritis (AGE) is a major cause of morbidity and remains a major cause of hospitalization. Following the Syrian refugee crisis and insufficient clean water in the region, this study reviews the etiological and epidemiological data in Lebanon. Methods: We prospectively analyzed demographic, clinical and routine laboratory data of 198 children from the age of 1 month to 10 years old who were admitted with the diagnosis of AGE to a private tertiary care hospital located in the district of Nabatieh in south Lebanon. Results: Males had a higher incidence of AGE (57.1%). Pathogens were detected in 57.6% (n=114) of admitted patients, among them single pathogens were found in 51.0% (n=101) of cases that consisted of: Entamoeba histolytica 26.3% (n=52), rotavirus 18.7% (n=37), adenovirus 6.1% (n=12) and mixed co-pathogens found in 6.6% (n=13). Breast-fed children were significantly less prone to rotavirus (p=0.041). Moreover, children who had received the rotavirus vaccine were significantly less prone to rotavirus (p=0.032). Conclusion: Our findings highlight the high prevalence of E. histolytica infection as the major cause of pediatric gastroenteritis in hospitalized children, during the summer period likely reflecting the insanitary water supplies and lack of hygiene. Moreover the 42.4% of unidentified causative pathogens should prompt us to widen our diagnostic laboratory arsenal by adopting new diagnostic technologies.

The Effect of Botox Injections on the Mechanical Properties of Skinned Fibres from Rabbit Paraspinal Muscles

S. K. Han(한상규),Kevin R Boldt,K. J. Chun(전경진),Walter Herzog,Venus Joumaa Korean Society for Precision Engineering 2021 한국정밀공학회 학술발표대회 논문집 Vol.2021 No.11월

Botulinum toxin type A (BTX-A) has been widely used for the treatment of muscle stiffness and hyperactivity, such as spasticity and dystonia in patients post-stroke or children with Cerebral Palsy. However, BTX-A injection has been shown to cause muscle atrophy, fat infiltration, fibrosis, and decreased force output in target muscles, but its potential effects on the contractile machinery and force production on the cellular level remain unknown. The aim of this study was to investigate the effects of BTX-A injections on the mechanical properties of skinned fibres from rabbit paraspinal muscles. Nineteen-month-old rabbits received either saline or BTX-A injections into the paraspinal muscles, equally distributed along the left and right sides of the spine at T12, L1, and L2 for five times during 24 weeks. Fibres were tested for their active and passive force-length relationships, unloaded shortening velocity and myosin heavy chain isoforms. BTX-A injections led to significant fat infiltration within the injected muscles and a greater proportion of IIa to IIx fibres. Single fast fibres from BTX-A injected animals had lower active force and unloaded shortening velocity compared to fibres from saline-injected control animals. Force and velocity properties were not affected by BTX-A injections for the slow fibres.