[The team is like a living being].
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Adaptation, Psychological↗
Biomedical subjects
C Marin
Publications and source records attributed to C Marin.
[The structural experience of a team].
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Communication↗
Dietary fat clearance is modulated by genetic variation in apolipoprotein A-IV gene locus.
Previous studies have shown that the A-IV-347Ser polymorphism is associated with the variability in low density lipoprotein (LDL)-cholesterol response to dietary therapy. The present study was designed to evaluate the association of this polymorphism with the individual variability observed in postprandial lipemic response. This polymorphism was characterized in 50 healthy male subjects homozygous for the apolipoprotein (apo)E3 allele. All subjects were subjected to a vitamin A-fat load test. Blood was drawn at time 0 and every hour over a period of 11 hours. Cholesterol and triglycerides (TG) in plasma and lipoprotein fractions of CH, TG, and retinyl palmitate (RP) were determined. Data from the postprandial lipemia revealed that subjects with the A-IV-347Ser allele (n = 14) have a lower postprandial response in total TG (P < 0.025), large triglyceride rich lipoproteins (TRL) TG (P < 0.02), and small-TRL TG levels (P < 0.007), and a higher postprandial response in large-TRL apoA-IV (P < 0.006) and apoB-100 (P < 0.041) levels than subjects homozygous for the A-IV-347Thr subjects (n = 36). In conclusion, the modifications observed in postprandial lipoprotein metabolism associated with this polymorphism within the apoA-IV gene locus may be involved in the variability in LDL-CH response observed in subjects consuming high saturated fat diets.
Adolescent↗
Juxtacortical chondromyxoid fibroma: imaging findings in three cases and a review of the literature.
Chondromyxoid fibroma is a rare bone neoplasm characterized by chondral, myxoid and fibrous differentiation. Uncommon locations include the bone surface. Roentgenography, MRI and ultrasound can suggest the diagnosis. However, diagnosis of chondromyxoid fibroma is rarely made prior to biopsy. We present the radiologic and pathologic findings in three patients with this tumor and a review of the literature.
Adult↗
Striatal synaptophysin levels are not indicative of dopaminergic supersensitivity.
Recent evidence suggests that behavioral supersensitivity to dopamine (DA) agonists observed in chronic neuroleptic-treated animals might be related to changes in synaptic morphology and density. The aim of this study was to test this hypothesis using Western blotting to determine the striatal synaptophysin levels in rats chronically treated with haloperidol followed by sub-acute administration of a DA agonist. Chronic haloperidol treatment (1 mg/kg/day for 21 days) produced an 88% increase in striatal synaptophysin levels and a 73% increase in apomorphine-induced stereotypes. Sub-acute administration of the DA D-1 receptor agonist SKF38393 (10 mg/kg/day for 5 days) or the DA D-2 receptor agonist quinpirole (1 mg/kg/day for 5 days) did not modify the haloperidol-induced increase in striatal synaptophysin levels. However, sub-acute administration of SKF38393 attenuated (62%) haloperidol-induced stereotypies. We conclude that there is no direct relationship between stereotyped behavior and synaptophysin levels indicating that striatal synaptophysin levels are not a good marker of dopaminergic supersensitivity.
2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
Immunological characterization of a neuronal antibody (anti-Tr) associated with paraneoplastic cerebellar degeneration and Hodgkin's disease.
We studied an autoantibody (called anti-Tr), found in the serum and CSF of five patients with paraneoplastic cerebellar degeneration (PCD) and Hodgkin's disease (HD). Anti-Tr antibodies labelled the cytoplasm of Purkinje cells of human and rat cerebellum. The molecular layer of rat cerebellum showed a characteristic dotted pattern suggestive of immunoreactivity of dendritic spines of Purkinje cells. Patients with cerebellar disorders without HD (159) or HD without PCD (30) did not harbor anti-Tr antibodies. Immunoblots of human Purkinje cells or rat and mouse cerebellum were negative. Anti-Tr antibodies, as defined in this study, appear specific for HD-associated PCD. The immunohistochemical pattern described in the rat cerebellum coupled with the absence of reactivity in the immunoblot may be used to identify anti-Tr antibodies.
Adolescent↗
Effect of 347-serine mutation in apoprotein A-IV on plasma LDL cholesterol response to dietary fat.
Lipid response to dietary fat and cholesterol is, to a large extent, genetically controlled. Apoprotein (apo) A-IV has been related to fat absorption and to the activation of some of the enzymes involved in lipid metabolism. One mutation has been described in the apo A-IV gene that causes substitution of Ser for Thr at position 347. To study the influence of this mutation on the plasma LDL cholesterol (LDL-C) response in diets of various fat content and fatty acid saturation, 41 healthy male subjects were studied, 25 of whom were homozygous for the Thr allele (347Thr) and the rest who were either homozygous (n = 2) or heterozygous carriers of the Ser allele (347Ser). They consumed three consecutive diets, each of 4 weeks' duration: one rich in saturated fat (SFA diet: 38% fat, 20% saturated), a National Cholesterol Education Program (NCEP) type 1 diet (28% fat, 10% saturated), and a third rich in monounsaturated fat (MUFA diet; 38% fat, 22% monounsaturated). Carriers of the 347Ser allele presented a greater decrease in total cholesterol (-0.7 vs -0.44 mmol/L, P < .034), LDL-C (-0.62 vs -0.31 mmol/L, P < .012), and apo B (-14 vs -8 mg/dL, P < .01) levels when they were switched from the SFA to the NCEP type 1 diet than homozygous carriers of the 347Thr allele. The change from the NCEP type 1 to the MUFA diet resulted in a greater increase in total cholesterol (0.18 vs -0.05 mmol/L, P < .028) and apo B (5 vs -1 mg/dL, P < .006) levels in the 347Ser than in the 347Thr individuals. In a previous study, we demonstrated that the G-->A polymorphism at position -76 of the gene promoter of apo A-I affects the LDL-C response to dietary fat. We therefore decided to study the effect of the interaction between these mutations on this response. We found that both mutations have an additive effect on total cholesterol, LDL-C, and apo B dietary-induced changes. Our results suggest that total cholesterol and LDL-C response to dietary fat is influenced by the 347Ser mutation of apo A-IV.
Adult↗
Dietary fat clearance in normal subjects is modulated by genetic variation at the apolipoprotein B gene locus.
Apolipoprotein B (apo B) plays a dominant role in cholesterol homeostasis. Several polymorphic sites within or adjacent to the gene locus for apo B have been detected. The X+ allele (XbaI restriction site present) of the XbaI restriction fragment polymorphism on the apo B gene has been found in some studies to be associated with higher serum cholesterol and/or triglyceride levels and with greater dietary response. The present study was designed to evaluate whether the apo B XbaI polymorphism was associated with the interindividual variability observed during postprandial lipemia. Fifty-one healthy young male volunteers [20 X-/X- (X-), and 31 X+/X- or X+/X+ (X+)], homozygotes for the apo E3 allele, were subjected to a vitamin A-fat load test. Subjects with the X- genotype had significantly greater retinyl palmitate (RP) and apo B-48 postprandial responses on both the large and the small TRL lipoprotein fractions compared with X+ subjects. In summary, subjects with the X-/X- genotype at the apo B locus have a greater postprandial response than X+ subjects. These differences observed in postprandial lipoprotein metabolism could explain some of the reported associations of this polymorphism to coronary heart disease risk.
Adolescent↗
Effect of 360His mutation in apolipoprotein A-IV on plasma HDL-cholesterol response to dietary fat.
In order to determine whether genetic variability of apolipoprotein (apo) A-IV is responsible for the improvement in lipid profile when dietary saturated fats are replaced by carbohydrates or monounsaturated fats, 41 healthy male subjects were studied: 33 were homozygous for the 360Gln allele and 8 were heterozygote carriers of the 360His allele. These were administered three consecutive 4-week diets. The first was a diet rich in saturated fat (SAT diet, with 38% fat, 20% saturated. This was followed by a low fat diet (NCEP-I, with < 30% fat, < 10% saturated). The final diet was rich in monounsaturated fat (MUFA diet, with 38% fat, 22% monounsaturated). There was no difference in plasma lipid and apolipoprotein levels of both groups of individuals after consuming the SAT diet. Switching from this diet to the NCEP-I diet, carriers of the 360His allele presented a greater decrease in high density lipoprotein-cholesterol (HDL-C) (-10 vs. -1 mg/dL, P < 0.004) and apoA-I levels (-19 vs. -8 mg/dL, P < 0.037). Similarly, replacement of carbohydrates by monounsaturated fats produced a greater increase in HDL-C (9 vs. 1 mg/dL, P < 0.003) and apoA-I levels (9 vs. 2 mg/dL, P < 0.036) in carriers of the 360His mutation. Lecithin:cholesterol acyltransferase (LCAT) and cholesteryl ester transfer protein (CETP) activities and apoA-IV levels were also measured. However, no genotype-related differences were observed for these parameters. Our results suggest that variability in HDL-C and apoA-I response to diet is, at least partially, determined by the 360His mutation of apoA-IV.
Adult↗
MK-801 prevents levodopa-induced motor response alterations in parkinsonian rats.
The systemic administration of the N-methyl-D-aspartate (NMDA) receptor antagonist, MK801 ((+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine) , has previously been found to reverse the motor response alterations that develop during long-term levodopa treatment of parkinsonian rats. To determine whether co-administration of MK801 with levodopa might prevent the initial appearance of these response changes, rats, rendered parkinsonian by a 6-hydroxydopamine lesion of the medial forebrain bundle, received either levodopa alone or levodopa with the NMDA receptor antagonist. After four weeks of treatment with levodopa alone, the duration of the turning response declined by 37% (P < 0.05) and the number of ineffectual levodopa injections had more than doubled (P < 0.05). MK801 co-treatment completely blocked the shortening in response duration and prevented the frequency of ineffectual levodopa injection from exceeding baseline levels in animals receiving levodopa alone. The total magnitude of the turning response to levodopa was not affected. These results suggest that NMDA receptor blockade may act prophylactically to prevent the appearance of motor response alterations in levodopa-treated parkinsonian rodents that resemble those occurring in levodopa-treated patients with Parkinson's disease.
Animals↗
Effect of long-term haloperidol treatment on striatal neuropeptides: relation to stereotyped behavior.
Behavioral and biochemical responses to D1 and D2 dopamine (DA) agonists were used to evaluate the participation of striatal peptidergic mechanisms in the motor function alterations that attend chronic neuroleptic treatment. Rats, given haloperidol (1 mg/kg, i.c.) for 21 consecutive days, were randomly allocated to one of the following treatments: the D1 agonist SKF 38393, the D2 agonist quinpirole, their combination or saline. Stereotyped behavior and neuropeptide levels were evaluated after 5 days treatment and 4 days washout. Haloperidol increased most oral behaviors including licking, chewing and biting as well as striatal enkephalin and somatostatin levels. Subsequent treatment with SKF 38393 diminished the haloperidol-induced increase in licking and chewing; quinpirole reduced chewing behavior. The administration of both agonists together decreased chewing and biting. Neither DA agonist alone, nor their combination, reduced the haloperidol-induced increase in enkephalin levels. Both SKF 38393 and quinpirole, when given alone, tended to decrease the haloperidol-induced increase in somatostatin levels; when both D1 and D2 agonists were administered together, somatostatin levels declined significantly. These results suggest that somatostatin- but not enkephalin-containing striatal neurons contribute to the expression of haloperidol-induced stereotypies.
Animals↗
Striatal c-fos levels do not correlate with haloperidol-induced behavioral supersensitivity.
Striatal c-fos levels and stereotyped behavior have been evaluated in chronically haloperidol-treated rats which received subsequent subacute dopamine (DA) agonist treatment to investigate the possible relationship between striatal c-fos and behavioral supersensitivity. Haloperidol treatment (1 mg/kg/day for 21 days) increased apomorphine-induced stereotypies but did not modify striatal c-fos levels. The subacute administration of the DA D-1 agonist SKF38393 (10 mg/kg/day for 5 days) and the combination of the D-1 agonist with the D-2 agonist quinpirole (1 mg/kg/day for 5 days) attenuated apomorphine-induced stereotypies after haloperidol pretreatment. The administration of quinpirole alone, however, did not modify the response to haloperidol. All DA agonists significantly increased c-fos levels after apomorphine injection. The dissociation between haloperidol-induced behavioral supersensitivity and striatal c-fos levels observed in this study suggests that mechanisms different from striatal c-fos induction might be involved, and that striatal c-fos levels are not a good marker of behavioral supersensitivity expression.
Animals↗
Effects of kappa receptor agonists on D1 and D2 dopamine agonist and antagonist-induced behaviors.
Striatal dynorphin-containing neurons receive dopaminergic inputs from the substantia nigra pars compacta and project primarily to the substantia nigra pars reticulata and entopeduncular nucleus. These neurons mainly express dopamine (DA) D1 receptors and thus dynorphin system stimulation might be expected largely to influence D1 receptor agonist or antagonist effects on motor function. It is well known the interaction existing between DA D1 and D2 drugs in the induction of behavioral effects. However, the effects of dynorphin on selective D1 and D2 DA agonist and antagonist-induced behaviors have not yet been investigated. Administration of the kappa agonists spiradoline (0.5, 1 and 5 mg/kg) or U50,488H (1, 10 and 25 mg/kg) decreased non-stereotyped grooming induced by the selective D1 agonist SKF38393. This effect was inhibited by the non-selective opioid receptor antagonist naloxone (20 mg/kg) and by the selective kappa antagonist nor-binaltorphimine (nor-BNI, 20 mg/kg). Stereotypies induced by the selective D2 agonist quinpirole were decreased by spiradoline (1 and 5 mg/kg) and by U50,488H (1, 10 and 25 mg/kg), while jerking movements of a type associated with increased D2 receptor and decreased D1 receptor stimulation emerged. Kappa agonist effects were inhibited by the prior administration of SKF38393 (10 mg/kg); these inhibitory effects were blocked by prior administration of the D1 antagonist SCH23390 (5 mg/kg). Naloxone reversed the effects of both kappa agonists on quinpirole-induced stereotypies. Kappa agonists increased D1 antagonist-induced catalepsy, but had no effect on D2 antagonist-induced catalepsy. Naloxone and nor-BNI inhibited this effect. These results suggest that the motoric effects of D1 receptor antagonists in part reflect stimulation of striatal dynorphin containing efferents.
2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
Effects of SCH 32615, an enkephalinase inhibitor, on D-1 and D-2 dopamine receptor-mediated behaviors.
Striatal enkephalin-containing neurons receive dopaminergic inputs from the substantia nigra and project to the external segment of globus pallidus. These neurons express primarily dopamine (DA) D-2 receptors. Accordingly, stimulation of enkephalinergic transmission might be expected to influence mainly D-2 receptor agonist or antagonist effects on motor function. To test this hypothesis, the effects of SCH 32615, an enkephalinase inhibitor, on DA antagonist-induced catalepsy, DA D-1 agonist-induced non-stereotyped grooming, and DA D-2 agonist-induced stereotyped behavior were studied. The administration of SCH 32615 (3 mg/kg) decreased both D-1 and D-2 antagonist-induced catalepsy. In contrast, SCH 32615 (0.3 mg/kg) increased D-1 agonist-induced non-stereotyped grooming and D-2 agonist-induced stereotypies. These results suggest that a DA agonist-like, mostly D-2 activity may be involved in enkephalinergic-mediated functions.
Animals↗
Glutathione-S-transferase as a marker of acute graft rejection in orthotopic liver transplantation.
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Alanine Transaminase↗
Influence of mutation in human apolipoprotein A-1 gene promoter on plasma LDL cholesterol response to dietary fat.
The plasma lipid response to changes in dietary fat and cholesterol can vary between individuals. At present, responders cannot be identified in advance. An adenine to guanine (A-->G) mutation in the promoter of the apolipoprotein A1 gene (apoA-1) has been suggested as affecting plasma high-density lipoprotein cholesterol. In 50 young men we examined the effect of the same mutation on the responses of both high and low density lipoprotein cholesterol to low-fat diet. The frequency for the A allele was 0.14. Subjects were fed a low-fat diet for 25 days, followed by a diet rich in monounsaturated fatty acid (MUFA, 22% out of 40% fat) for 28 days and lipoproteins were measured at the end of each diet. There were no differences in initial total cholesterol between subjects with the G/G mutation (170 mg/dL: 100 mg/dL = 2.59 mmol/L) and the G/A mutation (169 mg/dL) genotypes. After consumption of the high monounsaturated fat diet, significant increases were noted in plasma LDL cholesterol (10 mg/dL, p = 0.035) in the G/A subjects but not in the G/G subjects (1 mg/dL, p = 0.996). These differences showed that a significant diet-gene interaction (p = 0.015) existed. No differences were observed on HDL cholesterol between groups. Plasma low-density lipoprotein cholesterol responsiveness to diet may be explained by variation at the apoA-I gene locus.
Adult↗
Hepatitis C in liver transplant patients.
The aim of this study was to determine whether infection by the hepatitis C virus (HCV) recurs after orthotopic liver transplantation (OLT) and to define the natural history of post-transplantation chronic hepatitis due to HCV. Of 70 patients, 10 (14.3%) were found to have antibodies to HCV before transplantation. After OLT 14 of the 70 patients (20%) had positive anti-HCV antibodies: 8 of 10 positive pre-OLT (80%) and 6 of 60 negative pre-OLT (10%). Of 14 patients anti-HCV+ post-OLT (57%), developed 8 chronic hepatitis: chronic persistent hepatitis in three patients, chronic lobular hepatitis in three patients and chronic, active hepatitis in two patients. We treated four patients with interferon obtaining normalization of transaminases in three of them after 6 months, but with a severe relapse in two. These results suggest that hepatitis C recurs in a majority, of liver transplant recipients and that morbidity is an important consideration. Interferon treatment of these patients requires further study to obtain conclusive results.
Adolescent↗
Differential effects of chronic dopamine D1 and D2 receptor agonists on rotational behavior and dopamine receptor binding.
The effects of chronic continuous and intermittent administration of the dopamine D1 receptor agonist SKF 38393 or the D2 receptor agonist quinpirole on rotational behavior and dopamine receptor binding were examined in rats with a unilateral 6-hydroxydopamine lesion of the nigrostriatal pathway. Continuous and intermittent SKF 38393 both decreased the rotational response to subsequent challenge with SKF 38393. Intermittent SKF 38393 increased quinpirole rotation, while continuous SKF 38393 had no effect. Continuous administration of quinpirole did not affect rotation elicited by either SKF 38393 or quinpirole. Intermittent quinpirole, however, increased both SKF 38393- and quinpirole-induced rotation. Autoradiographic techniques were used to measure D1 receptor binding in striatum and substantia nigra pars reticulata and D2 receptor binding in striatum and nucleus accumbens. Intermittent SKF 38393 reduced D1 receptor Bmax and increased D1 Kd in the striatum, while both continuous and intermittent treatment with the D1 agonist decreased D1 binding in the substantia nigra pars reticulata. Intermittent quinpirole decreased D1 receptor Kd in striatum, and continuous quinpirole reduced D1 binding slightly in substantia nigra pars reticulata. Striatal D2 receptor binding was unaffected by treatment with either SKF 38393 or quinpirole. Intermittent SKF 38393 and continuous quinpirole both reversed the lesioned-induced elevation in D2 binding in the nucleus accumbens, while intermittent quinpirole decreased D2 binding in the accumbens on both the intact and denervated sides. Thus, the effects of chronic treatment with D1 and D2 agonists on behavioral responses to D1 and D2 receptor stimulation differed considerably and were dependent on the treatment regimen employed.(ABSTRACT TRUNCATED AT 250 WORDS)
2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗