ABSTRACT
Chronic intermittent hypoxia (CIH) is a feature of obstructive sleep apnea (OSA). Whereas clinical studies have demonstrated the association between OSA and insulin resistance, the molecular mechanisms behind it are still unknown. Herein we investigated the effect of mild CIH on insulin sensitivity and we evaluated the changes in insulin and HIF signaling pathways that occur in CIH-induced insulin resistance. We showed that mild CIH obtained by 5/6 hypoxic (5%O2) cycles/h, 10.5h/day during 28 and 35 days increased arterial blood pressure. Insulin resistance and insulinemia increased with CIH duration, being significantly different after 35 days of CIH. Thirty-five days of CIH decreased insulin receptor expression and phosphorylation in skeletal muscle and adipose tissue, but not in the liver. Conversely, Glut2 expression increased in the liver of CIH-animals. Thirty-five days of CIH up-regulated HIF-1α in the liver and down-regulated HIF-1α and HIF-2α in skeletal muscle. We concluded that the effect of CIH on insulin sensitivity and signaling is time-dependent and is associated with changes in HIF signaling in insulin-sensitive tissues.
Subject(s)
Basic Helix-Loop-Helix Transcription Factors/metabolism , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Hypoxia/metabolism , Insulin Resistance/physiology , Adipose Tissue/metabolism , Animals , Arterial Pressure/physiology , Body Weight , Disease Models, Animal , Glucose Transporter Type 2/metabolism , Glucose Transporter Type 4/metabolism , Insulin/blood , Lipids/blood , Liver/metabolism , Male , Muscle, Skeletal/metabolism , Phosphorylation , Rats, Wistar , Receptor, Insulin/metabolism , Sleep Apnea, Obstructive/metabolismABSTRACT
The carotid bodies (CBs) are peripheral chemoreceptors that respond to hypoxia increasing minute ventilation and activating the sympathetic nervous system. Besides its role in ventilation we recently described that CB regulate peripheral insulin sensitivity. Knowing that the CB is functionally blocked by hyperoxia and that hyperbaric oxygen therapy (HBOT) improves fasting blood glucose in diabetes patients, we have investigated the effect of HBOT on glucose tolerance in type 2 diabetes patients. Volunteers with indication for HBOT were recruited at the Subaquatic and Hyperbaric Medicine Center of Portuguese Navy and divided into two groups: type 2 diabetes patients and controls. Groups were submitted to 20 sessions of HBOT. OGTT were done before the first and after the last HBOT session. Sixteen diabetic patients and 16 control individual were included. Fasting glycemia was143.5 ± 12.62 mg/dl in diabetic patients and 92.06 ± 2.99 mg/dl in controls. In diabetic patients glycemia post-OGTT was 280.25 ± 22.29 mg/dl before the first HBOT session. After 20 sessions, fasting and 2 h post-OGTT glycemia decreased significantly. In control group HBOT did not modify fasting glycemia and post-OGTT glycemia. Our results showed that HBOT ameliorates glucose tolerance in diabetic patients and suggest that HBOT could be used as a therapeutic intervention for type 2 diabetes.
Subject(s)
Blood Glucose/metabolism , Carotid Body/physiology , Diabetes Mellitus, Type 2/therapy , Homeostasis , Hyperbaric Oxygenation , Aged , Female , Glucose Tolerance Test , Humans , Male , Middle AgedABSTRACT
Leptin is a hormone produced mostly in adipose tissue and playing a key role in the control of feeding and energy expenditure aiming to maintain a balance between food intake and metabolic activity. In recent years, it has been described that leptin might also contributes to control ventilation as the administration of the hormone reverses the hypoxia and hypercapnia commonly encountered in ob/ob mice which show absence of the functional hormone. In addition, it has been shown that the carotid body (CB) of the rat expresses leptin as well as the functional leptin-B receptor. Therefore, the possibility exists that the ventilatory effects of leptin are mediated by the CB chemoreceptors. In the experiments described below we confirm the stimulatory effect of leptin on ventilation, finding additionally that the CB does not mediate the instant to instant control of ventilation.
Subject(s)
Carotid Body/physiology , Leptin/pharmacology , Respiration/drug effects , Animals , Blood Glucose/analysis , Catecholamines/metabolism , Hypoxia/physiopathology , Leptin/blood , Rats , Rats, WistarABSTRACT
INTRODUCTION: Distress may affect a patient's ability to cope with and manage disease. AIM: To report distress prevalence in adult patients with bleeding disorders and determine whether specific clinical and health characteristics, including disease severity and employment status, are associated with distress. METHODS: Patients who visited a Haemophilia Treatment Centre (HTC) between January 1st, 2012 through February 28th, 2014 and who completed a distress screen, pain screen and questionnaire were evaluated cross sectionally. Distress was measured by the National Comprehensive Cancer Network Distress Management Tool, which allowed patients to rate recent distress on a 0-10 point scale. A rating of five or more was categorized as high distress. Pain was measured by the Brief Pain Inventory Short Form, which asked patients to rate pain types on 0-10 point scales. Patients reported employment and other demographic and behavioural information on the questionnaire. Primary diagnosis, age, HIV and HCV status were abstracted from medical records. Adjusted logistic regression was used to identify distress associations. RESULTS: High distress prevalence among 152 patients with bleeding disorders was 31.6%. Unemployment, disability, greater depressive symptoms and higher pain were associated with high distress in multivariable models. Bleeding disorder diagnosis, race/ethnicity, HIV/HCV status and on-demand treatment regimen were not associated with high distress. CONCLUSION: Distress among patients with congenital bleeding disorders followed at a comprehensive HTC was high and similar to that reported among patients with cancer. Future research should determine whether distress impacts clinical outcomes in patients with bleeding disorders as demonstrated in other chronic disorders.
Subject(s)
Depression/etiology , Hemorrhage/psychology , Adult , Cohort Studies , Cross-Sectional Studies , Depression/epidemiology , Female , Humans , Male , Quality of LifeABSTRACT
OBJECTIVE: Assess the radiation exposure of surgical staff during sentinel node surgery in gynecology using a radiotracer, the (99m)Tc-microalbumin. MATERIALS AND METHODS: A monocentric, prospective study was conducted during 3 months representing 40 sentinel node surgical procedures with different dosimetric measurements. Dosimeters were used to evaluate the whole body and the fingers radiation exposure for all exposed workers (surgeon, nurse and surgical assistant). Another dosimeter was used to estimate the atmospheric radiation level. The activity of (99m)Tc-microalbumin was 50.1±2.4MBq when the surgery was performed the same day and 90.4±3.2MBq when the surgery was performed the day after. RESULTS: Radioactive doses received during each procedure by the surgeon, surgical assistant and nurse are 5, 3.75 and 0µSv for whole body exposure and 17.5, 15.6 and 16.2µSv for extremities respectively. Atmosphere dosimeter does not detect any radiation over this period. On average, 200 procedures are performed each year in our hospital by 7 surgeons. Surgeon's radiation exposure remains below the threshold of 1mSv annual for whole body and 50mSv annual for fingers set for public by the International Commission on Radiological Protection. DISCUSSION AND CONCLUSIONS: During sentinel node surgery radiation exposure of surgical staff is weak. Everyone, including the surgeon, receives a dose below the limits of the public radiation exposure. There is no need for special dosimetric monitoring or use radiation protective devices during the sentinel node surgery using (99m)Tc-microalbumin injection.
Subject(s)
Health Personnel , Occupational Exposure , Radiopharmaceuticals/adverse effects , Sentinel Lymph Node Biopsy/methods , Surgeons , Technetium Tc 99m Aggregated Albumin/adverse effects , Breast Neoplasms/surgery , Female , Humans , Lymph Nodes , Prospective Studies , Radiometry , Risk FactorsABSTRACT
BACKGROUND/AIMS: Neuroinflammation plays a crucial role in the pathogenesis of Alzheimer's disease (AD). Its relationship with underlying ß amyloid deposition remains unclear. In vivo visualization of microglial activation has become possible with the development of molecular imaging ligands when used with positron emission tomography (PET). The translocator protein (TSPO) is upregulated during neuroinflammation. Consequently, targeting TSPO with radiolabeled ligands for PET is an attractive biomarker for neuroinflammation. METHODS: A review of the research literature on PET imaging which studied in vivo neuroinflammation in AD subjects and its relationship with amyloid load was performed, including papers published between 2001 and 2012. RESULTS: Six studies were included using either [(11)C]PK-11195 or another non-TSPO radioligand that binds to the monoaminooxidase B. All the studies evaluated amyloid load with [(11)C]PIB. Microglial activation and astrocytosis are potentially early phenomena in AD. However, the individual levels of amyloid deposition and microglial activation were not correlated. CONCLUSION: Noninvasive in vivo molecular imaging to visualize neuroinflammation in AD may contribute to our understanding of the kinetics of neuroinflammation and its relationship to the hallmarks of the disease. Both are important for the development of future therapeutic modalities and for quantifying the efficacy of future disease-modifying treatments.
Subject(s)
Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Amyloid beta-Peptides/metabolism , Brain/pathology , Inflammation/pathology , Molecular Imaging/methods , Aged , Aged, 80 and over , Alzheimer Disease/diagnostic imaging , Aniline Compounds , Benzothiazoles , Humans , Isoquinolines , Mitochondrial ADP, ATP Translocases/metabolism , Monoamine Oxidase/metabolism , Positron-Emission Tomography , Radiopharmaceuticals , Thiazoles , tau Proteins/metabolismABSTRACT
PURPOSE: Positron emission tomography (PET) imaging of brain amyloid load has been suggested as a core biomarker for Alzheimer's disease (AD). The aim of this study was to test the feasibility of using PET imaging with (18)F-AV-45 (florbetapir) in a routine clinical environment to differentiate between patients with mild to moderate AD and mild cognitive impairment (MCI) from normal healthy controls (HC). METHODS: In this study, 46 subjects (20 men and 26 women, mean age of 69.0 ± 7.6 years), including 13 with AD, 12 with MCI and 21 HC subjects, were enrolled from three academic memory clinics. PET images were acquired over a 10-min period 50 min after injection of florbetapir (mean ± SD of radioactivity injected, 259 ± 57 MBq). PET images were assessed visually by two individuals blinded to any clinical information and quantitatively via the standard uptake value ratio (SUVr) in the specific regions of interest, which were defined in relation to the cerebellum as the reference region. RESULTS: The mean values of SUVr were higher in AD patients (median 1.20, Q1-Q3 1.16-1.30) than in HC subjects (median 1.05, Q1-Q3 1.04-1.08; p = 0.0001) in the overall cortex and all cortical regions (precuneus, anterior and posterior cingulate, and frontal median, temporal, parietal and occipital cortex). The MCI subjects also showed a higher uptake of florbetapir in the posterior cingulate cortex (median 1.06, Q1-Q3 0.97-1.28) compared with HC subjects (median 0.95, Q1-Q3 0.82-1.02; p = 0.03). Qualitative visual assessment of the PET scans showed a sensitivity of 84.6% (95% CI 0.55-0.98) and a specificity of 38.1% (95% CI 0.18-0.62) for discriminating AD patients from HC subjects; however, the quantitative assessment of the global cortex SUVr showed a sensitivity of 92.3% and specificity of 90.5% with a cut-off value of 1.122 (area under the curve 0.894). CONCLUSION: These preliminary results suggest that PET with florbetapir is a safe and suitable biomarker for AD that can be used routinely in a clinical environment. However, the low specificity of the visual PET scan assessment could be improved by the use of specific training and automatic or semiautomatic quantification tools.
Subject(s)
Amyloid/metabolism , Aniline Compounds , Brain/diagnostic imaging , Brain/metabolism , Ethylene Glycols , Positron-Emission Tomography/methods , Aged , Alzheimer Disease/diagnostic imaging , Aniline Compounds/adverse effects , Cognitive Dysfunction/diagnostic imaging , Ethylene Glycols/adverse effects , Female , Follow-Up Studies , Humans , Male , Positron-Emission Tomography/adverse effectsABSTRACT
BACKGROUND: Congenital hyperinsulinism (CHI) is characterised by an over secretion of insulin by the pancreatic ß-cells. This condition is mostly caused by mutations in ABCC8 or KCNJ11 genes encoding the SUR1 and KIR6.2 subunits of the ATP-sensitive potassium (K(ATP)) channel. CHI patients are classified according to their responsiveness to diazoxide and to their histopathological diagnosis (either focal, diffuse or atypical forms). Here, we raise the benefits/limits of the genetic diagnosis in the clinical management of CHI patients. METHODS: ABCC8/KCNJ11 mutational spectrum was established in 109 diazoxide-unresponsive CHI patients for whom an appropriate clinical management is essential to prevent brain damage. Relationships between genotype and radiopathological diagnosis were analysed. RESULTS: ABCC8 or KCNJ11 defects were found in 82% of the CHI cases. All patients with a focal form were associated with a single K(ATP) channel molecular event. In contrast, patients with diffuse forms were genetically more heterogeneous: 47% were associated with recessively inherited mutations, 34% carried a single heterozygous mutation and 19% had no mutation. There appeared to be a predominance of paternally inherited mutations in patients diagnosed with a diffuse form and carrying a sole K(ATP) channel mutation. CONCLUSIONS: The identification of recessively inherited mutations related to severe and diffuse forms of CHI provides an informative genetic diagnosis and allows prenatal diagnosis. In contrast, in patients carrying a single K(ATP) channel mutation, genetic analysis should be confronted with the PET imaging to categorise patients as focal or diffuse forms in order to get the appropriate therapeutic management.
Subject(s)
ATP-Binding Cassette Transporters/genetics , Congenital Hyperinsulinism/genetics , Mutation , Potassium Channels, Inwardly Rectifying/genetics , Receptors, Drug/genetics , Congenital Hyperinsulinism/diagnosis , Congenital Hyperinsulinism/drug therapy , DNA Mutational Analysis , Diazoxide/therapeutic use , Drug Resistance , Female , Genotype , Humans , Infant , Infant, Newborn , Male , Sulfonylurea Receptors , Vasodilator Agents/therapeutic useABSTRACT
OBJECTIVE: To establish phenotype-genotype correlations in early-onset Parkinson disease (EOPD), we performed neurologic, neuropsychological, and psychiatric evaluations in a series of patients with and without parkin mutations. BACKGROUND: Parkin (PARK2) gene mutations are the major cause of autosomal recessive parkinsonism. The usual clinical features are early-onset typical PD with a slow clinical course, an excellent response to low doses of levodopa, frequent treatment-induced dyskinesias, and the absence of dementia. METHODS: A total of 44 patients with EOPD (21 with and 23 without parkin mutations) and 9 unaffected single heterozygous carriers of parkin mutations underwent extensive clinical, neuropsychological, and psychiatric examinations. RESULTS: The neurologic, neuropsychological, and psychiatric features were similar in all patients, except for significantly lower daily doses of dopaminergic treatment and greater delay in the development of levodopa-related fluctuations (p < 0.05) in parkin mutation carriers compared to noncarriers. There was no major difference between the two groups in terms of general cognitive efficiency. Psychiatric manifestations (depression) were more frequent in patients than in healthy single heterozygous parkin carriers but did not differ between the two groups of patients. CONCLUSION: Carriers of parkin mutations are clinically indistinguishable from other patients with young-onset Parkinson disease (PD) on an individual basis. Severe generalized loss of dopaminergic neurons in the substantia nigra pars compacta in these patients is associated with an excellent response to low doses of dopa-equivalent and delayed fluctuations, but cognitive impairment and special behavioral or psychiatric symptoms were not more severe than in other patients with early-onset PD.
Subject(s)
Cognition Disorders/genetics , Depressive Disorder/genetics , Genetic Predisposition to Disease/genetics , Parkinson Disease/genetics , Ubiquitin-Protein Ligases/genetics , Adult , Age of Onset , Aged , Antiparkinson Agents/administration & dosage , Antiparkinson Agents/adverse effects , Cognition Disorders/diagnosis , Cognition Disorders/epidemiology , Comorbidity , DNA Mutational Analysis , Depressive Disorder/diagnosis , Depressive Disorder/epidemiology , Disease Progression , Drug Resistance/genetics , Female , Genetic Testing , Genotype , Humans , Male , Middle Aged , Parkinson Disease/epidemiology , Parkinson Disease/psychology , Severity of Illness IndexABSTRACT
AIM: The aim of the present study was to analyse the effects of training performed on a rotating, motorised platform (the Huber/SpineForce device from LPG Systems, Valence, France) intended to improve, postural control and muscle function. SUBJECTS: Twelve healthy adults (divided into a sedentary group and an active group) took part in a two-month training programme (involving three sessions a week) on the SpineForce whole body rehabilitation device. METHOD: Instrumental assessment of postural control (on a Satel platform) and muscle function (on a Cybex Norm) was performed before and after training. Postural control in various conditions was measured using a position parameter (the mean anteroposterior position of the centre of foot pressure [CoP]) and two stability parameters (maximum CoP displacement and CoP sway area). Assessment of the muscle function was performed during knee and spine extension and featured maximum voluntary isometric contraction (MVIC), root mean square (RMS) and neuromuscular efficiency (MVIC/RMS) measurements. RESULTS: For static postural control, we observed a more forward CoP position in the maximum backward inclination condition (p<0.01) and a decrease in maximum CoP displacement in the "eyes closed on foam" and "maximum anterior inclination" conditions. In this latter condition, a lower CoP sway area was also noted (p<0.01). In terms of muscle function, a greater MVIC for knee extension was observed in the sedentary group only (p<0.05). These changes were not correlated with each another (p<0.05). However, the value of the pretraining maximum CoP displacement predicted its final value (p<0.05). CONCLUSION: Our results suggest that static postural control responds to training on a Huber((R))/SpineForce rehabilitation device. It seems probable that a population with a low initial level of physical activity would benefit most from training on this type of device. This training could notably be applied to elderly or disabled people and especially those with sensorimotor disabilities.
Subject(s)
Disabled Persons/rehabilitation , Exercise Therapy/instrumentation , Muscle Strength , Postural Balance , Rehabilitation/instrumentation , Adult , Electromyography , Female , Humans , Isometric Contraction , Kinesthesis , Male , Middle Aged , Occupations , Statistics, Nonparametric , Surveys and Questionnaires , Time FactorsABSTRACT
OBJECTIVES: A decrease of [(18)F]fluoro-l-dopa uptake in basal ganglia was recently reported in medically refractory epilepsy. The purpose of this study was to assess the involvement of dopaminergic neurotransmission in refractory temporal lobe epilepsy (TLE) and its relationship to glucose metabolism and morphologic changes. METHODS: Twelve TLE patients were studied using [(18)F]fluorodeoxyglucose PET, [(18)F]fluoro-l-dopa PET, and MRI and compared with healthy control volunteers. Morphologic cerebral changes were assessed using voxel-based morphometry. Student t test statistical maps of functional and morphologic differences between patients and controls were obtained using a general linear model. RESULTS: In TLE patients, [(18)F]fluoro-l-dopa uptake was reduced to the same extent in caudate and putamen in both cerebral hemispheres as well as in the substantia nigra (SN). These dopaminergic functional alterations occurred without any glucose metabolism changes in these areas. The only mild morphologic abnormality was found in striatal regions without any changes in the SN. CONCLUSION: The present study provides support for dopaminergic neurotransmission involvement in temporal lobe epilepsy. The discrepancies between gray matter volume atrophy and the pattern of [(18)F]fluoro-l-dopa suggest that basal ganglia involvement is not related to structural subcortical abnormalities. A functional decrease can be ruled out because there was no change of the glycolytic pathway metabolism in these areas.
Subject(s)
Basal Ganglia Diseases/diagnostic imaging , Basal Ganglia Diseases/etiology , Basal Ganglia/diagnostic imaging , Basal Ganglia/physiopathology , Epilepsy, Temporal Lobe/complications , Epilepsy, Temporal Lobe/diagnostic imaging , Adolescent , Adult , Basal Ganglia/metabolism , Basal Ganglia Diseases/physiopathology , Dihydroxyphenylalanine/analogs & derivatives , Dopamine/metabolism , Down-Regulation/physiology , Energy Metabolism/physiology , Epilepsy, Temporal Lobe/physiopathology , Female , Fluorodeoxyglucose F18 , Glucose/metabolism , Humans , Male , Middle Aged , Neostriatum/diagnostic imaging , Neostriatum/metabolism , Neostriatum/physiopathology , Neural Pathways/diagnostic imaging , Neural Pathways/metabolism , Neural Pathways/physiopathology , Positron-Emission Tomography , Predictive Value of Tests , Sensitivity and Specificity , Substantia Nigra/diagnostic imaging , Substantia Nigra/metabolism , Substantia Nigra/physiopathologyABSTRACT
Neonatal hyperinsulinism is a life-threatening disease that, when treated by total pancreatectomy, leads to diabetes and pancreatic insufficiency. A more conservative approach is now possible since the separation of the disease into a nonrecurring focal form, which is cured by partial surgery, and a diffuse form, which necessitates total pancreas removal only in cases of medical treatment failure. The pathogenesis of the disease is now divided into K-channel disease (hyperinsulinemic hypoglycemia, familial [HHF] 1 and 2), which can mandate surgery, and other metabolic causes, HHF 3 to 6, which are treated medically in most patients. The diffuse form is inherited as a recessive gene on chromosome 11, whereas most cases of the focal form are caused by a sulfonylurea receptor 1 defect inherited from the father, which is associated with a loss of heterozygosity on the corresponding part of the mother's chromosome 11. The rare bifocal forms result from a maternal loss of heterozygosity specific to each focus. Paternal disomy of chromosome 11 is a rare cause of a condition similar to Beckwith-Wiedemann syndrome. A preoperative PET scan with fluorodihydroxyphenylalanine and perioperative frozen-section confirmation are the types of studies done before surgery when needed. Adult variants of the disease are less well defined at the present time.
Subject(s)
Congenital Hyperinsulinism , ATP-Binding Cassette Transporters/genetics , Biopsy , Congenital Hyperinsulinism/genetics , Congenital Hyperinsulinism/pathology , Congenital Hyperinsulinism/physiopathology , Congenital Hyperinsulinism/therapy , Frozen Sections , Humans , Infant , Infant, Newborn , Insulin-Secreting Cells/pathology , Islets of Langerhans/pathology , Munchausen Syndrome/diagnosis , Nesidioblastosis/pathology , Pancreas/embryology , Potassium Channels/genetics , Potassium Channels, Inwardly Rectifying/genetics , Receptors, Drug/genetics , Sulfonylurea ReceptorsABSTRACT
We report an adult patient lacking endogenous synthesis of monoamines (dopamine, serotonin, and catecholamines) due to a severe dihydropteridine reductase (DHPR) deficiency. With levodopa and 5-hydroxytryptophan (5HTP) supplementation, the patient exhibited moderate mental retardation, acute episodes of parkinsonism, and episodes of depression. Despite the use of levodopa from age 3 months, he exhibited no dyskinesia or dopaminergic cell loss as suggested by normal PET imaging of the dopamine transporter.
Subject(s)
5-Hydroxytryptophan/therapeutic use , Dyskinesia, Drug-Induced/etiology , Levodopa/therapeutic use , Phenylketonurias/diagnosis , Phenylketonurias/drug therapy , Adult , Antidepressive Agents, Second-Generation/therapeutic use , Dopamine Agents/therapeutic use , Drug Combinations , Dyskinesias , Humans , Longitudinal Studies , Male , Treatment OutcomeABSTRACT
The striatum, a subcortical structure, is the principal target of the neurodegenerative process in Huntington's disease (HD). The measurement of striatal atrophy using the bicaudate ratio on CT scanner images has therefore been used for years to assess disease progression, but this measure only takes into account unidimensional changes in the head of the caudate nucleus. Recently, voxel-based morphometry (VBM), which permits automated statistical comparisons of whole-brain MRI images, has been proposed to quantify striatal atrophy. However, VBM was not originally designed to study subcortical structures, and severe deep brain deformations that occur in HD may hamper the automatic processing of VBM. Here, we validate the use of the optimised protocol of VBM to quantify subcortical atrophy in HD by comparing results obtained with this method to those provided by manual segmentation of subcortical structures. We studied 20 patients with early HD and 12 controls matched for age, sex and handedness using an improved T1-weighted sequence that eased grey matter segmentation. Both manual and automated methods evidenced the dorso-ventral gradient of striatal atrophy, a loss of grey matter in the globus pallidus and the thalamus, and similar correlations between clinical scores and subcortical atrophy. Furthermore, we were able to detect with VBM grey matter loss in the substantia nigra, the hypothalamus, the amygdala, the insular cortex and the premotor and sensorimotor cortices. Finally, VBM provided results consistent with previous post mortem results and proved to be a sensitive biomarker capable of correctly managing subcortical distortions throughout HD patients' brains.
Subject(s)
Brain/pathology , Huntington Disease/pathology , Adult , Atrophy , Basal Ganglia/pathology , Basal Ganglia/physiopathology , Brain/physiopathology , Female , Globus Pallidus/pathology , Globus Pallidus/physiopathology , Humans , Huntington Disease/physiopathology , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Middle Aged , Nonlinear DynamicsABSTRACT
Spatial and temporal density and biomass distribution of the planktonic copepods Pseudodiaptomus richardi and P. acutus along a salinity gradient were investigated in the Caeté River Estuary (North-Brazil) in June and December, 1998 (dry season) and in February and May, 1999 (rainy season). Copepod biomass was estimated using regression parameters based on the relation of dry weight and body length (prosome) of adult organisms. The Caeté River Estuary was characterized by high spatial and temporal variations in salinity (0.8-37.2). Exponential length-weight relationships were observed for both Pseudodiaptomus species. Density and biomass values oscillated between 0.28-46.18 ind. m-3 and 0.0022-0.3507 mg DW. m-3 for P. richardi; and between 0.01-17.02 ind. m-3 and 0.0005-0.7181 mg DW. m-3 for P. acutus. The results showed that the contribution of P. richardi for the secondary production in the Caeté River Estuary is more important in the limnetic zone than in other zones where euhaline-polyhaline regimes were predominant. However, it was not possible to observe a clear pattern of spatial and temporal distribution for P. acutus.
Subject(s)
Biomass , Copepoda/classification , Animals , Brazil , Population Density , Population Dynamics , Rivers , SeasonsABSTRACT
A distribuição espacial e temporal da densidade e biomassa dos copépodos planctônicos Pseudodiaptomus richardi e P. acutus, ao longo de um gradiente de salinidade, foi estudada no Estuário do Rio Caeté (Norte do Brasil) durante os meses de junho e dezembro de 1998 (estação seca) e fevereiro e maio de 1999 (estação chuvosa). A biomassa dos copépodos foi estimada a partir de parâmetros da regressão baseada na relação entre o peso seco e o comprimento do corpo (prossoma) de organismos adultos. O Estuário do Rio Caeté caracterizou-se por uma grande variação espacial e sazonal na salinidade (0,8-37,2). A relação peso-comprimento para ambas as espécies de Pseudodiaptomus foi do tipo exponencial. Os valores de densidade e biomassa oscilaram entre 0,28-46,18 ind. m-3 e 0,0022-0,3507 mg DW. m-3 para P. richardi; e entre 0,01-17,02 ind. m-3 e 0,0005-0,7181 mg DW. m-3 para P. acutus. Os resultados revelaram que a contribuição de P. richardi para a produção secundária no Estuário do Rio Caeté é mais importante na zona liminética que em outras zonas onde foram dominantes os regimes eurihalino-polihalino. Contudo, para P. acutus não foi possível observar de forma clara um padrão de distribuição espacial e temporal para a área estudada.
Subject(s)
Animals , Biomass , Copepoda/classification , Brazil , Population Density , Population Dynamics , Rivers , SeasonsABSTRACT
Congenital hyperinsulinism (HI) is the most important cause of hypoglycaemia in early infancy. The inappropriate oversecretion of insulin is responsible for profound hypoglycaemias requiring aggressive treatment to prevent severe and irreversible brain damage. Several classifications of HI can be attempted, based on: 1) the onset of hypoglycemia in the neonatal period or later in infancy; 2) the histological lesion: focal or diffuse; 3) the genetic transmission: sporadic, recessive, or less frequently dominant. The most common underlying mechanism of HI is dysfunction of the pancreatic ATP-sensitive potassium channel (K(+)(ATP)). The 2 subunits of the K(+)(ATP) channel are encoded by either the sulfonylurea receptor gene (SUR1 or ABCC8) or the inward-rectifying potassium channel gene (KIR6.2. or KCNJ11), both located in the 11p15.1 region. Focal CHI has been shown to result from a paternally inherited mutation on the SUR1 or KIR6.2 gene and loss of the maternal 11p15 allele restricted to the pancreatic lesion. Diffuse HI, frequently due to mutations of the SUR1 or KIR6.2 genes of autosomal recessive inheritance is genetically heterogeneous. The distinction between the focal and the diffuse HI is very important, because the treatments are different. To distinguish between focal and diffuse HI, transhepatic catheterisation with pancreatic venous sampling was the reference technique, but will likely be replaced by [(18)F] Fluoro-L-Dopa PET scan, which is easier to perform. In absence of response to the medical treatment (diazoxide) a limited pancreatectomy permits to cure focal HI, while a diffuse HI requires a subtotal pancreatectomy with high risk of subsequent diabetes mellitus.
Subject(s)
ATP-Binding Cassette Transporters/genetics , Congenital Hyperinsulinism/complications , Congenital Hyperinsulinism/genetics , Potassium Channels, Inwardly Rectifying/genetics , Potassium Channels/genetics , Receptors, Drug/genetics , ATP-Binding Cassette Transporters/physiology , Child , Child, Preschool , Congenital Hyperinsulinism/pathology , Congenital Hyperinsulinism/surgery , Diazoxide/therapeutic use , Female , Humans , Infant , Male , Mutation , Pancreatectomy , Potassium Channels/physiology , Potassium Channels, Inwardly Rectifying/physiology , Receptors, Drug/physiology , Sulfonylurea Receptors , Vasodilator Agents/therapeutic useABSTRACT
BACKGROUND: Studies in animal models and epileptic patients have suggested that circuits of the basal ganglia may control epileptic seizures and that striatal dopaminergic transmission plays a key role in seizure interruption. Ring chromosome 20 (r[20]) epilepsy is a very homogenous type of epilepsy and is clinically characterized by long-lasting seizures suggesting a dysfunction in the seizure control system. The hypothesis that these long-lasting seizures are associated with a reduction of striatal dopamine was addressed in the present study in drug-resistant patients with r(20) epilepsy using PET. METHOD: The authors performed [18F]fluoro-l-DOPA PET in 14 patients with r(20) epilepsy and compared uptake constants in the putamen and the caudate with those of 10 controls. In addition, the authors examined the correlation between these constants and the percentage of cells with r(20) mosaicism. RESULTS: [18F]fluoro-l-DOPA uptake was significantly decreased bilaterally in the putamen and in the caudate nucleus of patients. This reduction was equal for both nuclei and was not correlated to the percentage of cells with r(20). CONCLUSION: Striatal dopamine is modulated in r(20) epilepsy; dysfunction of this neurotransmission may impair the mechanisms that interrupt seizures.