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2.
J Vet Intern Med ; 31(3): 922-927, 2017 May.
Article in English | MEDLINE | ID: mdl-28303655

ABSTRACT

BACKGROUND: The signalment, clinicopathologic, bacteriological, histopathological, ultrasonographic characteristics, and the treatment and outcomes of adult cattle with cholangiohepatitis are poorly defined. ANIMALS: Thirteen Holstein cows with cholangiohepatitis. METHODS: Retrospective study of medical records of cattle admitted to the CHUV and the AVC between 1992 and 2012 and 2000 and 2012, respectively, for cattle older than 3 months of age with a histopathological diagnosis of cholangiohepatitis. Cholangiohepatitis was defined as the presence of portal inflammation surrounding or infiltrating bile ducts, with or without epithelial damage, and extending into the adjacent lobules. RESULTS: At the time of diagnosis of cholangiohepatitis, cows had decreased appetite (n = 7) or were anorectic (n = 6), had fever (n = 5), and had tachycardia (n = 8). Icterus was detected in 5 cows. Yellow discoloration was identified on the skin of the udder (n = 3), conjunctiva (n = 2), and vulva (n = 1). There was leukocytosis (n = 6), neutrophilia (n = 9), and hyperfibrinogenemia (n = 8). Alteration in the serum biochemistry profile included hyperglobulinemia (n = 8), hypoalbuminemia (n = 10), increased activity of GGT (n = 12), AST (n = 8), and ALP (n = 10), and hyperbilirubinemia (n = 10). Histopathological diagnosis included mild, subacute, nonsuppurative cholangiohepatitis (n = 4), mild suppurative cholangiohepatitis (n = 4), mild mixed (neutrophilic and lymphocytic) cholangiohepatitis (n = 3), and moderate, chronic, nonsuppurative cholangiohepatitis (n = 1). Six cows were discharged from the hospital, and 7 were euthanized. CONCLUSIONS AND CLINICAL IMPORTANCE: Cholangiohepatitis is a rare condition in adult cattle. Antemortem diagnosis can be challenging because clinical signs are unspecific.


Subject(s)
Cattle Diseases/pathology , Cholangitis/veterinary , Animals , Bile Ducts/pathology , Biopsy/veterinary , Cattle , Cattle Diseases/diagnosis , Cattle Diseases/diagnostic imaging , Cattle Diseases/therapy , Cholangitis/diagnosis , Cholangitis/pathology , Cholangitis/therapy , Female , Liver/pathology , Retrospective Studies , Ultrasonography/veterinary
3.
Appetite ; 84: 316-21, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25450892

ABSTRACT

BACKGROUND: Acute exercise has been shown to induce nutritional adaptations in obese and lean inactive youth but it remains unclear whether youth with a high level of physical activity experience such exercise-induced energy intake and appetite modifications. METHODS: 14 (15- to 16-year-old) male elite rugby players completed sessions on three separate occasions: (1) a control session (CON); (2) an exercise session (EX) and; (3) a rugby session (RUGBY). The energy induced by the rugby and exercise sessions was matched (Polar Team2 pro technology), and participants' energy intake, food preferences (ad libitum buffet meals) and appetite feelings (Visual Analogue Scales) were assessed throughout the experimental days. RESULTS: The energy intake during lunch and snack time was not different between conditions. Dinner time energy intake was significantly increased after RUBGY compared to CON with respectively 969 ± 145 kcal and 777 ± 183 kcal (p < 0.05). The energy intake at dinner time was significantly increased during EX (1185 ± 199 kcal) compared to both CON (p < 0.001) and RUGBY (p < 0.01). None of the appetite feelings investigated were modified between sessions. CONCLUSION: Adolescent elite rugby players regulate their energy intake differently depending on the nature of their training; independently of the energy expended. This demonstrates the need for energetic and nutritional education to optimize their physical fitness and performance.


Subject(s)
Appetite/physiology , Energy Intake/physiology , Energy Metabolism/physiology , Exercise/physiology , Feeding Behavior , Football/physiology , Adolescent , Humans , Male , Meals , Oxygen Consumption , Physical Fitness , Sports Nutritional Physiological Phenomena
4.
J Dairy Sci ; 97(1): 212-21, 2014.
Article in English | MEDLINE | ID: mdl-24183688

ABSTRACT

The objectives of the current study were (1) to determine the gain in prognostic accuracy of preoperative l-lactate concentration (LAC) measured on farm on cows with right displaced abomasum (RDA) or abomasal volvulus (AV) for predicting negative outcome; and (2) to suggest clinically relevant thresholds for such use. A cohort of 102 cows with on-farm surgical diagnostic of RDA or AV was obtained from June 2009 through December 2011. Blood was drawn from coccygeal vessels before surgery and plasma LAC was immediately measured by using a portable clinical analyzer. Dairy producers were interviewed by phone 30 d following surgery and the outcome was determined: a positive outcome if the owner was satisfied of the overall evolution 30 d postoperatively, and a negative outcome if the cow was culled, died, or if the owner reported being unsatisfied 30 d postoperatively. The area under the curve of the receiver operating characteristic curve for LAC was 0.92 and was significantly greater than the area under the curve of the receiver operating characteristic curve of heart rate (HR; 0.77), indicating that LAC, in general, performed better than HR to predict a negative outcome. Furthermore, the ability to predict a negative outcome was significantly improved when LAC measurement was considered in addition to the already available HR data (area under the curve: 0.93 and 95% confidence interval: 0.87, 0.99). Important inflection points of the misclassification cost term function were noted at thresholds of 2 and 6 mmol/L, suggesting the potential utility of these cut-points. The 2 and 6 mmol/L thresholds had a sensitivity, specificity, positive predictive value, and negative predictive value for predicting a negative outcome of 76.2, 82.7, 53.3, and 93.1%, and of 28.6, 97.5, 75, and 84%, respectively. In terms of clinical interpretation, LAC ≤2 mmol/L appeared to be a good indicator of positive outcome and could be used to support a surgical treatment decision. The treatment decision for cows with LAC between 2 and 6 mmol/L, however, would depend on the economic context and the owner's attitude to risk in regard to potential return on its investment. Finally, performing a surgical correction on commercial cows with RDA or AV and a LAC ≥6 mmol/L appeared to be unjustified and these animals should be culled based on their high probability of negative outcome.


Subject(s)
Abomasum/pathology , Cattle Diseases/diagnosis , Lactates/blood , Stomach Diseases/diagnosis , Stomach Diseases/veterinary , Animals , Cattle , Cattle Diseases/blood , Cattle Diseases/pathology , Female , Prognosis , Sensitivity and Specificity , Stomach Diseases/pathology
5.
Bone Marrow Transplant ; 48(11): 1401-8, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23749103

ABSTRACT

We report French prospective experience with reduced-intensity conditioning-allo-SCT in 46 patients (median age: 15.5 years, 4.8-20.2) presenting high-risk AL (n=11), Hodgkin's lymphoma (n=15) or solid tumors (n=20). Graft sources were BM (n=21), PBSC (n=20) and cord blood (CB; n=5) from related (n=20) or unrelated (n=26) donors. For CB grafts, only one patient out of five achieved sustained engraftment. For PBSC/BM grafts, engraftment rate was 95%, hematopoietic recovery times were not significantly different between BM, PBSC, sibling or unrelated grafts, day+100. Full donor chimerism was achieved in 94% of patients, and incidences of primary acute GVHD and chronic GVHD were 49% and 14%, respectively. Underlying disease was fatal in 39% of patients. TRM was 6.9%. Three-year OS was 49.15%. OS and EFS were not significantly different between patients transplanted with different grafts and with or without primary GVHD. Patients with solid tumor or measurable disease at transplant had poorer outcomes. Three-year EFS: 33.3% for ALL, 75.0% for AML, 51.8% for Hodgkin's lymphoma, 28.6% for neuroblastoma and 22.2% for sarcoma patients. This multicentre study concluded that Bu/fludarabine/anti-thymocyte globulin conditioning with PB or BM, related or unrelated grafts in patients with various malignancies at high-risk for transplantation toxicity results in high engraftment rates, low TRM and acceptable survival.


Subject(s)
Hematopoietic Stem Cell Transplantation/methods , Neoplasms/therapy , Transplantation Conditioning/methods , Adolescent , Adult , Child , Child, Preschool , Female , France , Humans , Male , Neoplasms/surgery , Prospective Studies , Tissue Donors , Transplantation, Homologous , Treatment Outcome , Young Adult
6.
Arch Pediatr ; 19(11): 1212-6, 2012 Nov.
Article in French | MEDLINE | ID: mdl-23037584

ABSTRACT

Acute megakaryoblastic leukemia accounts for approximately 3-10% of acute myeloid leukemia in children. Its diagnosis may be difficult because of associated myelofibrosis. We report the case of a 7-month-old child who presented hepatomegaly with bicytopenia. She also developed bone and joint pain with recurrent aseptic arthritis. We suggested the diagnosis of megakaryoblastic leukemia early but multiple bone marrow investigations had been processed without positive results because of sampling problems and lack of abnormal cells in the morphological, phenotypic, and cytogenetic examinations. We had a variety of indirect evidence for our assumption: the x-ray showing periosteal new bone, lytic lesions and metaphyseal bands, bone marrow aspirate smears with micromegakaryocytes, and bone marrow biopsy suggesting myelofibrosis. This was very suggestive of leukemia but we could not prove it and we finally found megakaryoblasts on bone marrow aspirate smears after more than 2 months of investigation and initiated a course of corticosteroids.


Subject(s)
Arthritis, Infectious/diagnosis , Bone Marrow Examination , Bone and Bones/pathology , Leukemia, Megakaryoblastic, Acute/diagnosis , Osteolysis/pathology , Periosteum/pathology , Primary Myelofibrosis/diagnosis , Anemia/etiology , Arthritis, Infectious/pathology , Biopsy , Bone Marrow/pathology , Child, Preschool , Diagnosis, Differential , Hepatomegaly/etiology , Humans , Infant , Leukemia, Megakaryoblastic, Acute/pathology , Liver/pathology , Megakaryocyte Progenitor Cells/pathology , Pancytopenia/etiology , Primary Myelofibrosis/pathology
7.
J Vet Intern Med ; 26(1): 32-45, 2012.
Article in English | MEDLINE | ID: mdl-22211394

ABSTRACT

BACKGROUND: Paratuberculosis has a worldwide distribution and many countries have implemented control programs to prevent transmission among and within herds. For these programs to be efficient, knowledge of the risk factors involved in transmission is essential. OBJECTIVES: Systematically review the scientific literature concerning risk factors associated with Mycobacterium avium subsp. paratuberculosis (MAP) transmission to dairy calves. STUDY DESIGN: Systematic review. METHODS: An electronic search was done in PubMed and CAB to retrieve references relevant to answer at least 1 of the 5 questions concerning neonatal environment, colostrum, milk, housing of calves, and contact of calves with adult cow feces as risk factors in MAP transmission. A 1st screening was done using titles only, then abstracts, and finally full-length articles were reviewed for relevance. From the articles selected, risk factors and presence of a significant association between these risk factors and MAP transmission were recorded. RESULTS: Twenty-three articles from 11 different countries and published in 12 different journals were reviewed. The most common study design was cross-sectional (n = 16). The case definition and diagnostic tests used were very variable among studies, but serum ELISA was used in most studies (n = 14). The study unit was the herd in 18 studies. CONCLUSIONS AND CLINICAL IMPORTANCE: The contact of calves with adult cow feces is the most important risk factor in MAP transmission. The 5 categories of risk factors are linked to one another.


Subject(s)
Cattle Diseases/microbiology , Cattle Diseases/transmission , Mycobacterium avium subsp. paratuberculosis/isolation & purification , Paratuberculosis/microbiology , Paratuberculosis/transmission , Animals , Animals, Newborn , Cattle , Risk Factors
8.
Child Care Health Dev ; 36(6): 835-42, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20645994

ABSTRACT

BACKGROUND: Obesity is increasing worldwide, reaching alarming proportions. Eating habits have changed over time and nowadays children and adolescents' environment favours the adoption of unhealthy eating behaviours leading to metabolic impairment. OBJECTIVE: To explore the impact of eating risk factors and their cumulative effect on anthropometric characteristics in French primary school children. METHODS: A total of 278 healthy French children (7.50 ± 0.67 years old) and their legal representatives agreed to take part in this study. Parents were asked to fill in an eating habits clinical questionnaire with questions about skipping breakfast, snacking between meals, eating in front of the TV and sugar-sweetened beverage consumption. On the basis of the answers, children were classified into four categories as a function of the number of eating risk factors they presented. Body mass index (BMI), the sum of four skinfolds (Σ4 skinfolds: tricipital, bicipital, sub-scapular and supra-iliac) and waist circumference (WC) were measured. BMI was transformed into z-BMI for each child. RESULTS: ANOVA and unpaired t-test provided significantly higher z-BMI, Σ4 skinfolds and WC in children who were used to skipping breakfast, snacking, watching TV while eating and consuming sugar-sweetened beverages. The more children accumulated eating risk factors, the higher were their z-BMI, Σ4 skinfolds and WC (MANOVA: P < 0.001). CONCLUSIONS: Eating habits appear to be associated with anthropometric characteristics in French primary school children. Anthropometric values (z-BMI, Σ4 skinfolds and WC) increased with the number of eating risk factors they presented.


Subject(s)
Energy Intake/physiology , Feeding Behavior/psychology , Obesity/etiology , Anthropometry , Body Mass Index , Body Weight , Child , Female , France , Humans , Male , Nutrition Surveys , Risk Factors , Schools , Surveys and Questionnaires , Time Factors
10.
Pediatr Transplant ; 14(1): 109-14, 2010 Feb.
Article in English | MEDLINE | ID: mdl-19490483

ABSTRACT

We report results of RIC AHSCT in four adolescents with aggressive refractory HL. They all received three or four lines of therapy prior to RIC-AHSCT including autografts. At the time of RIC, they were in partial response except for one patient who had progressive chemoresistant disease. The conditioning regimen consisted of fludarabin, busulfan and ATG. They all had a matched related donor. The median follow-up was 12-16-month post-allograft. All patient transplants engrafted rapidly. The median time of hospitalization was 35 days. The median time to neutrophil recovery (>or=500/muL) was 19 days. All the patients were in complete donor chimerism at day 60. Four patients developed skin (grade

Subject(s)
Busulfan/therapeutic use , Hematopoietic Stem Cell Transplantation/methods , Hodgkin Disease/surgery , Myeloablative Agonists/therapeutic use , Vidarabine/analogs & derivatives , Adolescent , Antineoplastic Agents/therapeutic use , Drug Therapy, Combination , Female , Follow-Up Studies , Hodgkin Disease/diagnosis , Hodgkin Disease/drug therapy , Humans , Male , Positron-Emission Tomography , Severity of Illness Index , Time Factors , Transplantation, Homologous , Treatment Outcome , Vidarabine/therapeutic use
11.
Arch Pediatr ; 13(12): 1521-4, 2006 Dec.
Article in French | MEDLINE | ID: mdl-17010579

ABSTRACT

UNLABELLED: Thrombotic thrombocytopenic purpura (TTP), when accompanied by regenerative anaemia with schizocytosis, thrombopenia and neurological manifestations, is a disease whose main characteristic is the absence of the von Willebrand factor (vWF) cleaving protease. The two types of TTP are distinguishable by the presence or absence of antiprotease inhibitors, which are, respectively, either acquired or constitutional. The acquired autoimmune form is most frequently observed in adults. OBSERVATION: An adolescent with a previous history of moderate, isolated thrombopenia first showed symptoms of TTP at the age of 14. Positive antiprotease inhibitors in combination with a degeneration of protease activity confirmed the diagnosis of acquired autoimmune TTP. A treatment consisting of daily plasma exchange led to rapid improvement; however, a failed attempt to space out plasma exchanges necessitated the introduction of 4 weekly injections of Rituximab beginning on day 40, which was successful. Indeed, since the second injection of Rituximab on day 51, the number of platelets stabilized at a normal level, thereby allowing for the complete cessation of plasma exchange. At this writing - day 89 - the patient remains in persistent remission. CONCLUSION: Given the different therapeutic and prognostic implications of the 2 types of TTP in child patients, it is mandatory to end at an accurate biological diagnosis: whereas the constitutional form is effectively treated with plasma injections, the acquired form, while initially requiring plasma exchange, often necessitates the use of immunosuppressors during acute or relapse phase. The present study concerns a paediatric case of acquired TTP treated successfully with Rituximab during an acute dependant phase.


Subject(s)
Purpura, Thrombocytopenic, Idiopathic , Purpura, Thrombotic Thrombocytopenic , Remission Induction , Adolescent , Age Factors , Antibodies, Monoclonal/administration & dosage , Antibodies, Monoclonal/therapeutic use , Antibodies, Monoclonal, Murine-Derived , Humans , Immunologic Factors/administration & dosage , Immunologic Factors/therapeutic use , Male , Plasma Exchange , Purpura, Thrombocytopenic, Idiopathic/diagnosis , Purpura, Thrombocytopenic, Idiopathic/drug therapy , Purpura, Thrombocytopenic, Idiopathic/therapy , Purpura, Thrombotic Thrombocytopenic/diagnosis , Purpura, Thrombotic Thrombocytopenic/drug therapy , Purpura, Thrombotic Thrombocytopenic/therapy , Rituximab , Time Factors , Treatment Outcome
12.
Int J Sports Med ; 26(4): 274-80, 2005 May.
Article in English | MEDLINE | ID: mdl-15795811

ABSTRACT

Gender-related differences in maximal leg muscle power were examined in 496 females and 426 males aged 8 to 20 years. Cycling peak power (CPP, including the force required to accelerate the flywheel of the cycle ergometer) was measured during three sprints. Optimal velocity (Vopt, velocity at CPP) was also determined. No gender-differences were observed in anthropometric characteristics and cycling performance between 8- and 14-year-old. From age 14, however, males showed a higher CPP than females, but also a higher lean leg volume (LLV, assessed by anthropometry). Allometric relationship between CPP and LLV (CPP = a . LLV ( b)) showed a clear gender-differentiation between 14- and 16-year-old: LLV exponent (b) was 1.05 in males vs. 0.74 in females. From 16 years onwards, analysis of covariance (ANCOVA) showed that the slopes of the CPP-LLV relationship were similar in both genders, but the intercepts differed. In other words, for a similar LLV, males showed greater CPP than females. It was suggested that this sex-related difference was due to total body fat increase, and more specifically lower-limb fat increase during puberty in girls, whilst the boys experienced increased lean body mass. Considering that the same gender-related difference was observed for optimal velocity adjusted for leg length, other factors such as fibre type variability or (and) neuromuscular activation might also be partly responsible for the higher peak muscle performance observed in males.


Subject(s)
Exercise/physiology , Growth/physiology , Muscle, Skeletal/physiology , Task Performance and Analysis , Adolescent , Adult , Age Factors , Body Size , Child , Exercise Test , Female , Humans , Male , Motor Activity/physiology , Regression Analysis , Sex Factors
13.
Arch Pediatr ; 11(11): 1326-32, 2004 Nov.
Article in French | MEDLINE | ID: mdl-15519830

ABSTRACT

UNLABELLED: To evaluate the percentage and risk factors of thyroid dysfunction in 79 children who underwent bone marrow transplantation in a single centre. PATIENTS AND METHODS: The mean age of the cohort was 6.8 and mean follow-up 5.5 years. The 79 patients were divided in two groups according to the pretransplant conditioning regimen: fractionated total body irradiation (TBI)(N=54), chemotherapy with Busulphan (N=25). Thyroid function was evaluated by thyroid-stimulating hormone (TSH) and free thyroxine (fT4) tests. Overt hypothyroidism was defined by low fT4 blood levels and TSH > 4 mU/l, and compensated hypothyroidism by normal fT4 index and TSH >4 mU/L. RESULTS: The six-year probability of hypothyroidism was 36 +/-6% for the whole group of 79 patients, 49 +/-8% after TBI and 9 +/-6% in the Busulphan group (P <0.001). Neither gender, nor primary disease, nor presence of graft versus host disease were found to be statistically significant for occurrence of hypothyroidism in the TBI group. However, a younger age seemed to influence statistically the 6-year probability of hypothyroidism in the TBI group: 59 +/-9% if age <7.7 years versus 34 +/-13% if age >7.7 years (P =0.02). CONCLUSION: A careful follow-up of thyroid function is recommended even without TBI conditioning regimen. Young age as a potential risk factor of hypothyroidism has never been described and needs to be studied in a larger cohort.


Subject(s)
Bone Marrow Transplantation/adverse effects , Hypothyroidism/etiology , Adolescent , Age Factors , Child , Child, Preschool , Cohort Studies , Female , Humans , Infant , Male , Neoplasms/therapy , Risk Factors , Whole-Body Irradiation/adverse effects
14.
Int J Artif Organs ; 27(4): 284-93, 2004 Apr.
Article in English | MEDLINE | ID: mdl-15163062

ABSTRACT

Fluidized bed bioreactor with alginate beads may be an alternative to hollow fiber cartridge to host hepatocytes for bioartificial liver purposes. After the bioreactor design and the characterization of fluid mechanics, the present study was aimed at analyzing bi-directional mass transfers of calibrated species between external fluid and empty beads. Static (batch) and dynamic (fluidized bed bioreactor) experimental conditions were analyzed. A simple modelling approach permitted the definition of mass transfer coefficients. The motion of beads within the bioreactor clearly enhanced mass transfer kinetics, but did not alter the amount exchanged. The shear enhanced diffusion coefficient for VitB12 was 20 times higher in the fluidized bed bioreactor than under batch conditions, proving the efficiency of such a device.


Subject(s)
Alginates/pharmacology , Bioreactors , Glucuronic Acid/pharmacology , Hexuronic Acids/pharmacology , Liver Failure/surgery , Liver, Artificial , Animals , Biocompatible Materials , Biotechnology , Cattle , Cells, Immobilized , Humans , Liver Failure/diagnosis , Liver Transplantation/methods , Microfluidics , Quality Control , Sensitivity and Specificity
15.
J Sports Med Phys Fitness ; 44(3): 272-80, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15756166

ABSTRACT

In comparison to continuous aerobic type activity, little is known about high-intensity intermittent physical activity in children. Repeated short-term high-intensity activities (> maximal aerobic speed and <10 s) are more characteristic of the spontaneous physical activity of children. Recent studies have shown during repetitive bouts of sprints separated by short recovery intervals, that prepubescent children compared with adults are more able to maintain their performance without substantial fatigue. Moreover, repetitive runs at high velocities (near and higher than the maximal aerobic speed) separated by short recovery periods may elicit a high oxygen consumption in children. Several studies using interval training programmes for 7 weeks, twice a week for 30 min in physical education lessons showed that children's aerobic performance (maximal O2 uptake, maximal aerobic speed) could be enhanced. Training based on these repeated short-term high-intensity exercises could also improve children's anaerobic performance (short-term muscle power, strength and speed). Current evidence suggests that recovery from high-intensity exercises is faster in children than in adults and that repeated runs at high velocities separated by short recovery intervals can improve both aerobic and anaerobic performance. Although continuous aerobic type activity is more scientifically established as a training mode, repeated short-term high-intensity exercises in physical education programmes should be considered to enhance aerobic, as well as, anaerobic fitness in children.


Subject(s)
Exercise/physiology , Physical Endurance/physiology , Child , Humans , Muscle, Skeletal/physiology , Oxygen Consumption/physiology , Physical Fitness/physiology
16.
Tissue Antigens ; 61(2): 146-53, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12694582

ABSTRACT

Insulin dependent diabetes mellitus (type I DM) is caused by an autoimmune process which culminates in destruction of pancreatic beta cells with resultant loss of insulin production. Preceding the clinical diagnosis of type I DM is a preclinical stage characterized by autoantibodies to insulin, glutamic acid decarboxylase (GAD) and a tyrosine phosphatase-like molecule (IA-2). We have studied both HLA class I and class 2 allele distributions in diabetic probands and autoantibody positive individuals in members of 452 families recruited for the Australian type I diabetes DNA repository. The results demonstrate that progression to autoimmunity as measured by the appearance of autoantibodies is strongly associated with the class 2 alleles DRB1*03 and DRB*04 and with DRB1*03/04 heterozygosity. In contrast, the progression to clinical disease appears associated with class I alleles A24, A30 and B18 while A1, A28, B14 and B56 appear negatively associated. The class 2 alleles appear to have a minimal role in the progression from autoantibody positivity to clinical disease. These results are consistent with the view that CD4+ T cells responding to peptides in the context of class 2 molecules are responsible for initiating autoantibody production, while the destruction of islet cells leading to clinical expression of the disease is the function of CD8+ T cells recognizing relevant peptides in the context of class I molecules.


Subject(s)
Autoimmunity/genetics , Diabetes Mellitus, Type 1/genetics , Diabetes Mellitus, Type 1/immunology , HLA Antigens/genetics , Alleles , Autoantibodies/blood , Case-Control Studies , Diabetes Mellitus, Type 1/etiology , Female , Gene Frequency , Genes, MHC Class I , Genes, MHC Class II , Haplotypes , Humans , Male , Prediabetic State/genetics , Prediabetic State/immunology
17.
Int J Sports Med ; 23(6): 397-402, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12215957

ABSTRACT

The aim of the present study was to investigate the effects of age and recovery duration on the time course of cycling peak power and blood lactate concentration ([La]) during repeated bouts of short-term high-intensity exercise. Eleven prepubescent boys (9.6 +/- 0.7 yr), nine pubescent boys (15.0 +/- 0.7 yr) and ten men (20.4 +/- 0.8 yr) performed ten consecutive 10 s cycling sprints separated by either 30 s (R30), 1 min (R1), or 5 min (R5) passive recovery intervals against a friction load corresponding to 50 % of their optimal force (50 % Ffopt). Peak power produced at 50 % Ffopt (PP50) was calculated at each sprint including the flywheel inertia of the bicycle. Arterialized capillary blood samples were collected at rest and during the sprint exercises to measure the time course of [La]. In the prepubescent boys, whatever recovery intervals, PP50 remained unchanged during the ten 10 s sprint exercises. In the pubescent boys, PP50 decreased significantly by 18.5 % (p < 0.001) with R30 and by 15.3 % (p < 0.01) with R1 from the first to the tenth sprint but remained unchanged with R5. In the men, PP50 decreased respectively by 28.5 % (p < 0.001) and 11.3 % (p < 0.01) with R30 and R1 and slightly diminished with R5. For each recovery interval, the increase in blood [La] over the ten sprints was significantly lower in the prepubescent boys compared with the pubescent boys and the men. To conclude, the prepubescent boys sustained their PP50 during the ten 10 s sprint exercises with only 30 s recovery intervals. In contrast, the pubescent boys and the men needed 5 min recovery intervals. It was suggested that the faster recovery of PP50 in the prepubescent boys was due to their lower muscle glycolytic activity and their higher muscle oxidative capacity allowing a faster resynthesis in phosphocreatine.


Subject(s)
Aging/metabolism , Bicycling , Physical Exertion/physiology , Adolescent , Adult , Aging/blood , Child , Fatigue , Humans , Lactic Acid/blood , Male , Oxygen Consumption
18.
J Sports Med Phys Fitness ; 41(3): 342-8, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11533565

ABSTRACT

BACKGROUND: In adult population, stretch-shortening cycle exercise (plyometric exercise) is often used to improve leg muscle power and vertical jump performance. In children, limited information regarding this type of exercise is available. The purpose of this study was to examine the effectiveness of plyometric training and maintenance training on physical performances in prepubescent soccer players. METHODS: Twenty boys aged 12-13 years was divided in two groups (10 in each): jump group (JG) and control group (CG). JG trained 3 days/week during 10 weeks, and performed various plyometric exercises including jumping, hurdling and skipping. The subsequent reduced training period lasted 8 weeks. However, all subjects continued their soccer training. Maximal cycling power (Pmax) was calculated using a force-velocity cycling test. Jumping power was assessed by using the following tests: countermovement jump (CMJ), squat jump (SJ), drop jump (DJ), multiple 5 bounds (MB5) and repeated rebound jump for 15 seconds (RRJ15). Running velocities included: 20, 30 and 40 m (V20, V30, V40 m). Body fat percentage (BF percent) and lean leg volume were estimated by anthropometry. RESULTS: Before training, except for BF percent, all baseline anthropometric characteristics were similar between JG and CG. After the training programme, Pmax (p<0.01), CMJ (p<0.01), SJ (p<0.05), MB5 (p<0.01), RRJ15 (p<0.01) and V20 m (p<0.05), performances increased in the JG. During this period no significant performance increase was obtained in the CG. After the 8-week of reduced training, except Pmax (p<0.05) for CG, any increase was observed in both groups. CONCLUSIONS: These results demonstrate that short-term plyometric training programmes increase athletic performances in prepubescent boys. These improvements were maintained after a period of reduced training.


Subject(s)
Physical Education and Training , Soccer/physiology , Adolescent , Anthropometry , Bicycling/physiology , Child , Humans , Male , Physical Fitness , Running/physiology , Statistics, Nonparametric
19.
Eur J Appl Physiol ; 84(5): 476-81, 2001 May.
Article in English | MEDLINE | ID: mdl-11417438

ABSTRACT

The purpose of this study was to determine whether the relationships between short-term power and body dimensions in young females were similar whatever the age of the individuals. A cohort of 189 prepubescent (mean age 9.5 years), adolescent (mean age 14.4 years) and young adult (mean age 18.2 years) females performed three all-out sprints on a friction-loaded cycle ergometer against three braking forces corresponding to applied loads of 25, 50 and 75 g.kg-1 body mass (BM). For each sprint, peak power including flywheel inertia was calculated. Results showed that a braking load of 75 g.kg-1 BM was too high for prepubescent and adolescent girls. Therefore, when measuring short-term cycling performance in heterogeneous female populations, a braking load of 50 g.kg-1 BM (0.495 N.kg-1 BM) is recommended. During growth, cycling peak power (CPP; defined as the highest peak power obtained during the three sprints) increased, as did total BM, fat-free mass (FFM) and lean leg volume (LLV) (P < 0.001). Analysis of covariance revealed that the slopes of the linear relationships between CPP and biometric characteristics were similar in the three groups (P > 0.7 for the CPP/BM and CPP/FFM relationships, and P > 0.2 for the CPP/LLV relationship). However, the adjusted means were always significantly higher in young women (P < 0.001) compared with both of the other groups. Although differences in performance during anaerobic cycling in growing females are primarily dependent upon body dimensions, other as yet undetermined factors may be involved during late adolescence.


Subject(s)
Aging/physiology , Bicycling/physiology , Puberty , Adolescent , Anaerobiosis , Body Constitution , Body Weight , Child , Female , Humans , Leg/anatomy & histology , Organ Size , Thinness
20.
Int J Sports Med ; 21(5): 360-5, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10950446

ABSTRACT

The purpose of this study was to determine to what extent anthropometric characteristics account for cycling peak power during growth. Five hundred and six male subjects aged 7.5-18 years performed three brief maximal sprints on a friction-loaded cycle ergometer. Cycling peak power (CPP) was calculated including the flywheel inertia of the device. Fat-free mass (FFM) and lean leg volume (LLV) were assessed by anthropometry. Anthropometric characteristics increased significantly during growth (p<0.001) but plateaued from about 16 years of age (p > 0.3). The same pattern was observed for CPP, while the time to reach CPP decreased during growth. CPP correlated as highly with LLV as with FFM and both parameters may therefore be interchanged. However, in non weight-bearing exercises, such as cycling, it seems more relevant to "normalise" leg power for LLV. Multiple stepwise regression, using an allometric model, showed that a large part of the variance of CPP was explained by LLV (88.2%, p<0.001). However, age and time to reach peak power also contributed significantly (approximately 3 %, p < 0.001). The prediction of CPP revealed that FFM and age contributed to 92.2% of the total variance of CPP. Because of its practicability, fat-free mass is particularly useful in prospective studies. Although the effects of dimensional changes in CPP during growth are obvious, undetermined qualitative changes of muscle function during maturation must be considered.


Subject(s)
Body Composition , Child Development , Exercise/physiology , Adolescent , Anthropometry , Child , Exercise Test/methods , Humans , Male , Weight-Bearing
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