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PubMed2000

Comparison of nuclear scintigraphy and acetaminophen absorption as a means of studying gastric emptying in horses.

OBJECTIVE: To evaluate the correlation between halftime of liquid-phase gastric emptying (T50), determined with nuclear scintigraphy using technetium Tc 99m pentetate, and absorption variables of orally administered acetaminophen. ANIMALS: 6 mature horses. PROCEDURE: Technetium Tc 99m pentetate (10 mCi) and acetaminophen (20 mg/kg of body weight) were administered simultaneously in 200 ml of water. Serial left and right lateral images of the stomach region were obtained with a gamma camera, and T50 determined separately for counts obtained from the left side, the right side and the geometric mean. Power exponential curves were used for estimation of T50 and modified R2 values for estimation of goodness of fit of the data. Serial serum samples were taken, and acetaminophen concentration was determined, using fluorescence polarization immunoassay. Maximum serum concentration (Cmax), time to reach maximum serum concentration (Tmax), area under the curve for 240 minutes and the absorption constant (Ka) were determined, using a parameter estimation program. Correlations were calculated, using the Spearman rank correlation coefficient. RESULTS: Correlations between T50 and Tmax and between T50 and Ka were significant. CONCLUSIONS AND CLINICAL RELEVANCE: Tmax and Ka are valuable variables in the assessment of liquid-phase gastric emptying using acetaminophen absorption. Acetaminophen absorption may be a valuable alternative to nuclear scintigraphy in the determination of gastric emptying rates in equine patients with normally functioning small intestine.

Acetaminophen↗

PubMed1988

Ventricular preload alters intravascular and extravascular resistances of coronary collaterals.

Coronary collateral blood flow is determined by both the collateral vessel resistance and a waterfall mechanism. The aim of this study was to determine which of these two mechanisms predominates during alteration of ventricular preload. The left anterior descending coronary artery of 12 anesthetized dogs was cannulated, and the distal vasculature was completely embolized with 25-micron diameter microspheres. Retrograde blood flow (RBF) was collected when the cannula was opened to the atmosphere, and the outflow tubing height was adjusted to provide a variable back pressure. RBF is back pressure-dependent at higher back pressures, and the slope in this region of the constructed pressure-flow relationship determines the collateral conductance. The transition point between the back pressure-dependent and a back pressure-independent region indicates a waterfall pressure impinging on the collateral vessels. At a left ventricular diastolic pressure of 9.3 mmHg, mean RBF, collateral conductance, and the collateral waterfall pressure were 7.3 ml/min, 0.175 ml.min-1.mmHg-1, and 30.1 mmHg, respectively. Corresponding values when preload was reduced to 3.5 mmHg were 9.3 ml/min, 0.186 ml.min-1.mmHg-1, and 23.7 mmHg, all changes being significant. Mean contribution to the overall increase in RBF was 0.5 ml/min for the conductance and 1.2 ml/min for the waterfall mechanism (P less than 0.05), or 29 and 71%, respectively. The results indicate that the extravascular resistance mechanism mediates the collateral flow response to a greater degree than the intravascular resistance during variations in preload. The increase in slope of the conductance portion of the relationship was not accompanied by a concomitant increase in slope of the back pressure-independent region. These data further support a collateral waterfall, and not collateral vessel compliance, as the basis for the back pressure-independent portion of the pressure-flow relationship.

Animals↗

PubMed1984

Ejection fraction and regional wall motion at rest and during stress in the diagnosis of coronary artery disease.

Stress radio nuclide ventriculography is used to determine ejection fraction and changes in regional wall motion for the detection of ischemia-induced left ventricular dysfunction in patients with coronary artery disease. We have evaluated the relative sensitivity of regional wall motion and of ejection fraction during hand-grip and cold pressor test, in 21 patients with angina pectoris and documented coronary artery disease at angiography. Regional wall motion appeared a more sensitive index than global ejection fraction producing only two false negative cases. Ejection fraction showed great variability among the patients during both hand-grip and cold pressor test. This might be explained by the fact that both tests do not produce a sufficient degree of ischemic stress on the left ventricle. Hand-grip and cold pressor tests appear useful alternative to dynamic exercise in the diagnosis of coronary artery disease being also safe and simple to perform.

Adult↗

PubMed2004

Distinct striatal regions support movement selection, preparation and execution.

The aim of this study was to determine whether distinct striatal territories are specifically involved during the selection, preparation and execution of a movement. Nine volunteers were studied using fMRI at 3 T. Subjects were presented with visual stimuli instructing them to prepare during a variable delay and then execute a button press with either the left or the right hand. The side of the movement was either freely selected by the subject (free selection) or specified by the instruction cue (preparation). Movement selection, preparation and execution were associated with activation in the caudate nucleus, the anterior and the posterior parts of the putamen, respectively. These results suggest that these three aspects of movement are represented within distinct basal ganglia regions.

Adult↗

PubMed1993

Alterations of heart rate and of heart rate variability after radiofrequency catheter ablation of supraventricular tachycardia. Delineation of parasympathetic pathways in the human heart.

BACKGROUND: Persistent inappropriate sinus tachycardia has been reported as a complication after radiofrequency (RF) ablation of the fast atrioventricular (AV) nodal pathway. The purpose of this study was to evaluate the prevalence of this complication and its mechanism using heart rate variability analysis. METHODS AND RESULTS: Time and frequency domain analysis of heart rate was performed in the electrophysiology laboratory immediately before and immediately after RF ablation in 64 patients with supraventricular tachycardia. Ablation targets in these 64 patients included the fast AV nodal pathway (n = 3), the slow AV nodal pathway (n = 14), a posteroseptal accessory pathway (n = 23), and a left lateral accessory pathway (n = 24). A control group of 21 patients undergoing diagnostic study but not ablation underwent identical analysis immediately before and at the conclusion of their procedure. Patients undergoing ablation also had time and frequency domain analysis performed on ambulatory 24-hour Holter tapes recorded before ablation and at 1 day, 1 month, and 6 months after ablation. Compared with preablation values, time domain analysis immediately after ablation revealed a significant increase in mean heart rate and significant reductions in heart rate variability expressed as SD, MSSD, and PNN50 in patients undergoing AV nodal modification or posteroseptal accessory pathway ablation. Frequency domain analysis revealed marked attenuation of high frequency (0.15 to 0.40 Hz) components, indicating parasympathetic denervation. These acute changes were not seen after ablation of left lateral accessory pathways or after diagnostic study without ablation. Time and frequency domain analysis of 24-hour ambulatory Holter monitors performed serially after ablation revealed resolution of abnormalities of heart rate and of heart rate variability 1 to 6 months after ablation, with reappearance of the high frequency parasympathetic component suggestive of reinnervation. CONCLUSIONS: RF ablation in the anterior, mid, and posterior regions of the low interatrial septum may disrupt preganglionic or postganglionic parasympathetic fibers located in these regions that are destined to innervate the sinus node. Such fibers become more scarce along the left AV groove with increasing distance from the posteroseptal space. Parasympathetic denervation may be one mechanism for persistent inappropriate sinus tachycardia after RF ablation.

Adult↗

PubMed1994

Variable region gene analysis of B cell subsets derived from a 4-year-old child: somatically mutated memory B cells accumulate in the peripheral blood already at young age.

Tonsillar germinal center and immunoglobulin M+ (IgM+)IgD+ B cells as well as peripheral blood (PB) CD5+ and CD5- (conventional) B cells from a 4-yr-old child were isolated and nucleotide sequences of expressed Ig heavy chain variable regions encoded by VH4 gene family members were determined from amplified cDNA. Whereas both tonsillar IgM+IgD+ cells and the majority of IgM-expressing CD5+ and CD5- PB B cells showed no or little somatic mutation, tonsillar germinal center (GC) B cells and IgG-expressing PB B cells carried a high load of somatic mutations in their V region genes. This suggests that somatically mutated memory B cells which have switched isotype accumulate in the PB already at young age. Their frequency seems to increase with age. On the other hand, the antibody repertoire of tonsillar IgM+IgD+ B cells and the majority of IgM-expressing PB B cells is determined by germline-encoded specificities and by generation of variability in the complementary determining region III through VH-DH-JH recombination. A fraction of IgM-bearing PB B cells carries somatically mutated V region genes and probably represents GC-derived B cells which have left the GC at an early stage of the GC reaction without undergoing isotype switching. 10 VH4 germline genes were found to be expressed. Three gene segments were overrepresented in the sequence collection (35 of 50 clones): VH4.21 (30%), V71-4 (20%), and 3D279D (20%). It appears that most potentially functional VH4 germline genes are expressed in peripheral B cells. Some members of this VH gene family are clearly overrepresented over others.

Amino Acid Sequence↗

PubMed1985

Effect of global vs regional ischaemia upon myocardial contractility and oxygen balance.

The possible role of catecholamines upon the nature of myocardial response to regional and global left ventricular ischaemia was investigated. Global ischaemia was accomplished by temporary occlusion of the left main coronary artery and regional ischaemia by temporary ligation of the left anterior descending coronary artery. Isometric force of contraction was measured with strain gauge arches, regional blood flow by a thermistor technique and intracellular NADH redox level by a fluorometric technique. These measurements were made simultaneously in two areas on the left ventricular myocardium: one immediately below the bifurcation of the LAD and the other immediately below the circumflex coronary artery. Following LAD occlusion a variable inotropic response was observed in the ischaemic area. A decrease in contractile tension was found in 19 of the dogs (44%), no change in 23% and an increase was found in 33%. Global ischaemia invariably resulted in a decrease in contractile tension. NADH redox state was markedly higher during global than during regional ischaemia. Propranolol administration blocked the positive inotropic response to regional ischaemia. It is concluded that endogenous catecholamine release may be responsible for increased contractile force during regional ischaemia. This response is apparently limited by the oxygen availability to the tissue.

Animals↗

PubMed1997

Regional HmPAO SPECT and CT measurements in the diagnosis of Alzheimer's disease.

BACKGROUND: This study investigated the hypothesis that the combination of regional CT brain atrophy measurements and semiquantitative SPECT regional blood flow ratios could produce a diagnostic test for Alzheimer's disease (AD) with an accuracy comparable to that achieved with the present clinical gold standard of the NINCDS-ADRDA criteria. METHODS: Single proton emission computed tomography (SPECT) and CT head scans were performed on 122 subjects referred an UBC Alzheimer clinic and diagnosed as either 'not demented' (ND-37) or 'possible/probable AD' (AD-85) by the NINCDS-ADRDA criteria. Stepwise discriminant analysis (SDA) was performed on the bilateral SPECT regions of interest and compared to bilateral CT qualitative/quantitative assessment in the frontal, parietal and temporal lobes to determine which were most accurate at ND/AD distinction. Receiver operating curves (ROC) were then constructed for these variables individually and for their combined discriminant function. RESULTS: The left temporal qualitative cortical atrophy score (CT) and left temporal perfusion ratio (SPECT) were selected in the SDA. The combined discriminant function was more specific at AD/ND distinction than either of CT or SPECT alone. The accuracy of AD/ND distinction with the combined discriminant function was below that achieved by clinical diagnosis according to the NINCDS-ADRDA criteria and was not significantly different from that achieved with SPECT or CT alone as defined by ROC curve analysis. CONCLUSION: The measurements of left temporal cortical atrophy and regional cerebral blood flow were most indicative of AD; however they lacked the sensitivity and specificity to recommend their use as a diagnostic test for AD.

Aged↗

PubMed1998

Brain activation during silent word generation evaluated with functional MRI.

This is a study of word generation during functional MRI (fMRI). Eleven normal healthy subjects were instructed to generate words covertly, (i.e., silently) that began with particular letters. Images were acquired on a conventional 1.5T scanner at three contiguous axial planes encompassing language-related areas of the temporal and frontal lobe. The data were analyzed at the level of a Talairach box, after individually fitting the proportional Talairach grid system to each slice. The main variable of interest was the number of activated pixels within a Talairach box. Boxes with a significant increase in the proportion of activated pixels were located in three regions of the left neocortex: (1) Brodmann areas 44 and 45 in the dorsolateral frontal cortex (Broca's area), (2) areas 21 and 37 in the temporal cortex, (3) and the striate/extrastriate cortex (areas 17 & 18). The results are discussed in terms of a cognitive model of word generation and are compared, in detail, with the results of prior relevant imaging studies.

Adolescent↗

PubMed1998

Functional anatomy of dominance for speech comprehension in left handers vs right handers.

In order to study the functional anatomy of hemispheric dominance for language comprehension we compared the patterns of activations and deactivations with PET and H(2)15O during a story-listening task in two groups of normal volunteers selected on the basis of their handedness. The reference task was a silent rest. The results showed asymmetrical temporal activations favoring the left hemisphere in right handers (RH) together with Broca's area and medial frontal activations. A rightward lateralization of deactivations located in the parietal and inferior temporal gyrus was also observed. In left handers (LH) the temporal activations were more symmetrical as were the parietal and inferior frontal deactivations. Broca's area and medial frontal gyrus activations were present in LH. The direct comparison of RH and LH activations revealed larger activations in the left superior temporal, in particular in the left planum temporale and temporal pole of RH, while LH activated an additional right middle temporal region. Individual analysis of LH differences images superimposed on individual MRI planes demonstrated an important variability of functional dominance, with two LH leftward lateralized, two symmetrical, and one showing a rightward lateralization of temporal activations. There was no relationship between functional dominance and handedness scores. These results are in accordance with data from aphasiology that suggest a greater participation of the right hemisphere in language processing in LH. In addition, the presence of bilateral deactivations of the dorsal route could support the assumption that LH ambilaterality concerns, in addition to language, other cognitive functions such as visuospatial processing.

Attention↗

PubMed2003

MRI study of white matter diffusion anisotropy in schizophrenia.

Diffusion tensor imaging (DTI) can provide information about brain white matter integrity. The results of DTI studies in schizophrenia are somewhat variable and could benefit from standardized image processing methods. Fourteen patients with schizophrenia or schizoaffective disorder and 14 healthy volunteers underwent DTI. Scans were analyzed using a rigorous voxelwise approach. The key dependent variable, fractional anisotropy, was lower for patients in the corpus callosum, left superior temporal gyrus, parahippocampal gyri, middle temporal gyri, inferior parietal gyri, medial occipital lobe, and the deep frontal perigenual region. Regions showing reduced white matter fractional anisotropy are known to be abnormal in schizophrenia. The voxelwise method used in the current study can provide the basis for hypothesis-driven research.

Adult↗

PubMed1993

In vivo quantification of myocardial echo intensity from logarithmically amplified, demodulated radiofrequency signals.

Clinical application of echocardiographic tissue characterization necessitates measurements through the chest wall. Different distances between transducer and myocardial region of interest result in variable attenuation effects. Therefore, meaningful comparisons of myocardial echo intensity measurements are difficult with current equipment. The present study aims at the quantification and compensation of depth-dependent attenuation effects. Ten normals, 14 patients with mild (n = 7) or moderate (n = 7) hypertensive left ventricular hypertrophy and 10 transplant candidates were examined. Gain-independent logarithmically amplified, demodulated radiofrequency signals of parasternal long axis cross-sections were digitized. Mean myocardial echo intensities were determined in septal and posterior wall regions of interest. The slope of attenuation was determined from these clinically obtained data by plotting the distances between transducer and regions of interest against myocardial echo intensities. An attenuation coefficient derived from this slope was used for compensation of the depth-dependent losses of myocardial echo intensity. Compared with normals, compensated mean myocardial echo intensities were significantly lower in mild or moderate hypertensive left ventricular hypertrophy, but showed no significant difference in transplant candidates. Despite several limitations, the method employed in this study appears to be a possible approach to in vivo quantification and compensation of attenuation.

Adult↗

PubMed1994

Cardiac myocyte function and left ventricular strains after brief ischemia and reperfusion in rabbits.

BACKGROUND: After a brief episode of ischemia, myocardial function may be depressed for prolonged periods despite reperfusion. The mechanisms of postischemic dysfunction differ depending on the experimental model. Regional ischemia and reperfusion in the intact animal provide a clinically relevant model, but experimental variables are difficult to control. Experimental conditions can be well controlled in isolated cardiac muscle and myocyte preparations, but these models are limited by the assumptions used to mimic ischemia and reperfusion. This study combines the unique advantages of both preparations. We characterized in vivo alterations in regional two-dimensional finite strains with ischemia and reperfusion produced in the intact animal, then isolated cardiac myocytes from the region with postischemic dysfunction to characterize in vitro function of postischemic myocytes. METHODS AND RESULTS: In seven anesthetized rabbits, three piezoelectric crystals were inserted in a triangular array to measure two-dimensional finite strains around the large coronary artery in the left ventricular anterior free wall. After 15 minutes of ischemia and reperfusion, strains were depressed at a stable level approximately 30% to 40% below control values between 1 and 6 hours after reperfusion. The direction of maximal shortening deformations was midway between circumferential and longitudinal directions during control and did not shift after reperfusion. In a second group of five rabbits, cardiac myocytes were isolated from the region with postischemic dysfunction after 15 minutes of ischemia and 45 minutes of reperfusion. We compared in vitro function in 45 postischemic myocytes with 48 cardiac myocytes isolated from five normal rabbits. Each rabbit (postischemic and control) contributed 9 +/- 1 (SD) myocytes to the study. All myocytes were studied within 1 hour after myocyte isolation (approximately 3 to 5 hours after reperfusion for postischemic myocytes). Myocytes were stimulated at 0.5 Hz and perfused with 2 mmol/L [Ca2+] Tyrode's solution to measure unloaded cell shortening. There was significantly less shortening in postischemic myocytes (12.4 +/- 2.1%) than control myocytes (16.2 +/- 1.2%). Maximal cell length (Lmax) was significantly longer in postischemic (134 +/- 7 microns) than control myocytes (122 +/- 7 microns), as was minimum cell length (Lmin) (118 +/- 8 versus 103 +/- 9 microns, respectively). The duration of shortening (time from stimulation to Lmin) was significantly shorter in postischemic (279 +/- 56 milliseconds) than control myocytes (405 +/- 44 milliseconds). Peak rates of cell shortening (-dL/dt) and lengthening (+dL/dt) did not differ. CONCLUSIONS: In rabbits, 15 minutes of ischemia produced a stable depression in finite strains for 1 to 6 hours after reperfusion, with shortening deformations reduced by approximately 30% to 40% without a shift in direction. Cardiac myocytes isolated from postischemic myocardium display functional impairments in vitro similar to those measured in vivo, with an approximately 25% reduction in unloaded myocyte shortening and decreased contraction duration. This indicates that ischemia and reperfusion induce intrinsic impairments in contractility independently of external loading conditions. This model may be useful for examining cellular mechanisms of postischemic myocardial dysfunction.

Animals↗

PubMed1987

Sex differences in exercise induced left ventricular dysfunction in patients with syndrome X.

Clinical, electrocardiographic, and scintigraphic data were reviewed from 32 patients (18 men and 14 women) who had syndrome X (chest pain, evidence of ischaemia, and normal coronary arteries without coronary vasospasm). The mean (SD) resting left ventricular ejection fraction, determined by first pass radionuclide angiography was 62.6 (9.2)% and was greater than 50% in all subjects. There was no significant difference between men and women. On exercise, left ventricular ejection fraction decreased significantly to 57.4 (13.0)%. In 17 of 32 subjects there was a fall in left ventricular ejection fraction of greater than 5%, and regional wall motion abnormalities developed in 12 subjects. The fall in left ventricular ejection fraction on exercise was significant in women (from 61.9 (8.5)% at rest to 54.0 (9.8)% on exercise) but not in men (from 63.2 (9.8)% at rest to 60.0 (14.8)% on exercise). Exercise left ventricular ejection fraction fell by greater than 5% in 10 (71%) of 14 women and in seven (39%) of 18 men. Dyskinetic segments developed in eight (57%) of 14 women and only four (22%) of men. Exercise duration in women was significantly shorter than in men (4.1 (1.5) vs 6.6 (2.1) minutes) and was the only one of several clinical and scintigraphic variables that correlated with the change in left ventricular ejection fraction on exercise. In this selected group of subjects with chest pain and angiographically normal coronary arteries, exercise induced left ventricular dysfunction, as shown by a fall in ejection fraction or the development of regional abnormalities, is a common finding. These are more likely to occur in women than men and are associated with a lower exercise capacity. The data suggest that the sex of the patient is important in the interpretation of the non-invasive evaluation of subjects suspected of having syndrome X.

Adult↗

PubMed1997

Prognostic value of slow resolution of ST-segment elevation following successful direct percutaneous transluminal coronary angioplasty for recovery of left ventricular function.

Our objective was to investigate the significance of the slow resolution of ST-segment elevation following a successful direct percutaneous transluminal coronary angioplasty (PTCA). ST-segment elevations were calculated from electrocardiograms recorded before PTCA and 1 hour after reperfusion. Forty-nine patients experiencing their first anterior acute myocardial infarction and who had undergone direct PTCA were classified into 3 groups: 17 patients with rapid ST resolution (group I), 23 patients with persistent ST elevation (group II), and 9 patients with ST reelevation (group III). Left ventricular function was evaluated by using single-plane cineventriculography performed in the acute stage, at discharge, and 4 months later. Peak creatine kinase activity was significantly increased: group III (4,046 +/- 634 IU), group II (3,336 +/- 772 IU), and group I (2,410 +/- 994 IU); p <0.05. Ejection fraction and regional wall motion in the acute stage were identical in each group. However, they were significantly higher in group I (67 +/- 6%, -1.01 +/- 0.30), followed by group II (56 +/- 6%, -1.90 +/- 0.41) and group III (38 +/- 7%, -2.79 +/- 0.46); p <0.01 4 months later. Multiple regression analysis revealed that the ST resolution was the only significant variable that indicated the recovery of regional wall motion. A good linear correlation was documented between the ST resolution and the recovery of regional wall motion. We concluded that a slow ST resolution after successful direct PTCA is a negative predictor of recovery of left ventricular function, especially when ST reelevation is evident.

Aged↗

PubMedDate not supplied

Intramuscular absorption and regional lymphatic uptake of liposome-entrapped inulin.

An investigation of the effects of the liposome variables (size, surface area, and amount of injected lipid) on the intramuscular absorption and subsequent lymphatic uptake of drug from the injection site (left muscle) and in the opposite (right) muscle and lymph node was done in mice. Two size ranges were studied (0.3-2.0 mu and 0.15-0.7 mu). Large multilamellar vesicles were studied at lipid doses of 20.7 and 9.0 mg/kg, whereas small multilamellar vesicles were investigated at a dose of 9.5 mg/kg. Liposomes were composed of phosphatidylcholine/cholesterol/phosphatidylserine/alpha-tocopherol/14C-dipalmitoylphosphatidylcholine (as a marker for the lipid phase), 4:5:1:0.01:0.01 (molar ratio). 3H-inulin was used to monitor the aqueous phase. At 24 hr after administration, large liposomes tended to result in the largest fraction of drug at the injection site, with the 3H/14C ratio indicating stability of the remaining vesicles. Small liposomes showed a greater uptake of inulin via the lymphatics. Decreasing the total amount of injected lipid resulted in a slower absorption of large liposomes and a greater uptake via the lymphatics.

Absorption↗

PubMed1990

Alterations in the regional beta adrenergic system in experimental left ventricular hypertrophy.

STUDY OBJECTIVE - The aim of the study was to determine the changes in the beta adrenergic system induced by cardiac hypertrophy due to valvular aortic stenosis. DESIGN - Density of beta adrenoceptors, cardiac tissue noradrenalime concentrations, coronary blood flow (using radioactive microspheres), and haemodynamic variables were compared in a model of experimental aortic valve stenosis of 6 month's duration and in sham operated controls. SUBJECTS - 14 mongrel dogs with aortic stenosis and eight sham operated litter mates were used in the studies. MEASUREMENTS and RESULTS - Heart weight to body weight ratio was 33% greater in dogs with aortic valve stenosis than in controls. There were no haemodynamic differences except for a left ventricular to aortic systolic pressure gradient of 38 (SD 22) mm Hg in the aortic stenosis group. Response of left ventricular dP/dtmax to dopamine was similar in the two groups, as was coronary flow. Density of beta adrenoceptors (Bmax) as measured by (125I)-iodopindolol binding was reduced in ventricles from the aortic stenosis group compared to control: 41.2(13.3) v 59.1(8.1) fmol.mg-1 protein, p less than 0.005. Affinity of receptor for ligand (Kd) was not affected by cardiac hypertrophy. Tissue noradrenaline concentration was reduced in the hypertrophy group: 1108(402) (control) v 438(13) ng.g-1 initial wet weight (aortic stenosis), p less than 0.05. There were no significant subepicardial v subendocardial differences in any variable. CONCLUSIONS - Cardiac hypertrophy induced by aortic valve stenosis over a 6 month period is accompanied by a decrease in the density of ventricular beta adrenoceptors per gram and a decrease in ventricular noradrenaline concentration, though responsiveness of the whole heart is maintained.

Animals↗

PubMed2005

Morphology of the anterior cingulate gyrus in patients with schizophrenia: relationship to typical neuroleptic exposure.

OBJECTIVE: The anterior cingulate gyrus is a pivotal component of brain networks directing affective and cognitive functions, and abnormalities of the anterior cingulate gyrus may be involved in the pathophysiology of schizophrenia. However, magnetic resonance imaging studies of the morphology of this region have been few and the results inconsistent. Many of the studies have not accounted for confounding factors such as gender, handedness, or clinical variables such as neuroleptic exposure. METHOD: The morphology and clinical correlates of the anterior cingulate gyrus were evaluated in a group of 30 right-handed male subjects with schizophrenia and a comparison group matched for age, sex, and handedness. The patient group was specifically designed to provide measures of multiple phenomenological differences such as severity of illness, duration of illness, and exposure to typical neuroleptics. RESULTS: The patient group had a significantly larger left anterior cingulate gyrus volume relative to comparison subjects, whereas right anterior cingulate gyrus volume did not differ between groups. Depth of the left anterior cingulate gyrus was significantly correlated with neuroleptic exposure, indicating that greater exposure to neuroleptics was associated with greater cortical depth of this region. There was no significant relationship between anterior cingulate gyrus morphology and duration of illness or severity of symptoms. CONCLUSIONS: Anterior cingulate gyrus depth in subjects with schizophrenia is directly related to typical medication exposure (the greater the exposure, the thicker the anterior cingulate gyrus) but not to other clinical variables such as length of illness or symptom severity. Future research is needed to determine the functional consequences of these changes and relationship to atypical neuroleptic use.

Adult↗