Usefulness of rectal biopsy for the diagnosis of Kufs disease: a controlled study and review of the literature.

BACKGROUND AND PURPOSE: Rectal biopsy is usually performed for in vivo diagnosis of Kufs disease (KD). We evaluated the usefulness of rectal biopsy in the diagnosis of such condition by comparing ultrastructural data of patients with suspicion of KD with those of control subjects. Furthermore, we reviewed literature data concerning the value of such a diagnostic procedure in the diagnosis of KD. METHODS: Sixty-five subjects were enrolled and underwent rectal biopsy. Of these, 13 had a clinical picture in keeping with KD, whereas 52, affected by Irritable Bowel Syndrome, constituted the control group. RESULTS: Ultrastructural analysis evidenced fingerprint (FP) inclusions in 12 subjects, 4/13 with suspicion of KD and 8/52 controls. In patients, FPs were mainly located in vascular smooth muscle cells (VSMC) while in controls they were mostly found in pericytes and VSMC. No FPs were found in one patient with genetically confirmed KD. In literature, we identified 14 KD patients who underwent rectal biopsy. In most reports, ultrastructural features were not systematically analyzed or described. CONCLUSIONS: Fingerprints are the most common ultrastructural finding in rectal biopsy in patients with suspicion of KD. However, their presence in pericytes and VSMC is not specific for KD because they may be found in controls subjects. Our literature review revealed that data on the value of rectal biopsy in the diagnosis of KD are scarce. In light of these findings, the relevance of rectal biopsy in such condition should be re-evaluated.

Pharmacodynamics of the long-duration response to levodopa in PD.

OBJECTIVE: To determine the latency, magnitude, and duration of the long-duration response (LDR) to levodopa in PD in relationship to the administration of levodopa at different interdose intervals. METHODS: In six patients with PD, two different 15-day treatment regimens were used in which the drug was administered with interdose intervals of 24 or 8 hours. RESULTS: The LDR built up within a few days with either regimen, but a faster rate of administering levodopa shortened the latency to the appearance of a sustained LDR. Once a sustained response had been reached, the magnitude of the LDR showed a stable ceiling effect that was independent of the levodopa schedule. After discontinuation of treatment, the decay of the LDR was similar for both regimens. CONCLUSIONS: The system underlying the LDR to levodopa may be completely saturated when a sustained response has been fully developed. The intervals between doses of levodopa shorter than the interval effective to reach a sustained LDR should not be used in the clinical management of patients with PD because the antiparkinsonian benefit deriving from the LDR is already maximal and briefer intervals do not provide a greater benefit.

The long-duration response to L-dopa in the treatment of early PD.

OBJECTIVE: To investigate the long-duration response (LDR) to L-dopa resulting from different regimens of L-dopa. BACKGROUND: In clinical practice, L-dopa is usually administered without considering the LDR due to the drug. Moreover, it has not been established whether in early PD a multiple daily intake of small doses of L-dopa may induce a sustained LDR. METHODS: Twenty-four patients with early PD underwent a double-blind, crossover trial, comparing three different 15-day treatment periods with L-dopa: treatment A (250 mg every 24 hours); treatment B (250 mg every 8 hours); and treatment C (125 mg every 8 hours). After completion, 20 patients underwent a subsequent open-label randomized trial with prolonged treatments (250 mg every 24 hours or 125 mg every 8 hours) up to 3 months. LDR was measured at the end of each treatment. RESULTS: All patients achieved a sustained LDR after treatments A and B, whereas only 17% of patients reached a sustained LDR after treatment C. Overall, the LDRs resulting from treatments A and B had similar magnitude and were larger than the LDR deriving from treatment C. After 3 months of prolonged treatments, only three of 10 patients treated with 125 mg every 8 hours increased their LDR, whereas all 10 patients treated with 250 mg every 24 hours had a maximal and stable LDR. CONCLUSIONS: Sustained LDR to L-dopa is dependent on the amount of the single doses of the drug. A regimen scheduling small, divided doses during the day, as done in clinical practice, is a questionable therapy for the achievement of a sustained LDR.

Dopamine D2 receptor gene polymorphism and the risk of levodopa-induced dyskinesias in PD.

OBJECTIVE: To investigate whether polymorphisms in the genes for dopamine receptors D1 and D2 are associated with the risk of developing peak-dose dyskinesias in PD. BACKGROUND: Peak-dose dyskinesias are the most common side effects of levodopa therapy for PD. The identified predictors may only partially account for the risk of developing peak-dose dyskinesias because a substantial proportion of patients never develop peak-dose dyskinesias. Genetic factors could play a role in determining the occurrence of peak-dose dyskinesias. METHODS: A case-control study of 136 subjects with sporadic PD and 224 population control subjects. We studied three polymorphisms involving the dopamine receptor D1 gene and one intronic short tandem repeat polymorphism of the dopamine receptor D2 gene. RESULTS: The polymorphisms of the dopamine receptor D1 gene were not associated with the risk of developing PD or peak-dose dyskinesias. The 15 allele of the polymorphism of the dopamine receptor D2 gene was more frequent in parkinsonian subjects than in control subjects. More important, the frequency of both the 13 allele and the 14 allele of the dopamine receptor D2 gene polymorphism was higher in nondyskinetic than in the dyskinetic PD subjects. The risk reduction of developing peak-dose dyskinesias for PD subjects carrying at least 1 of the 13 or 14 alleles was 72% with respect to the PD subjects who did not carry these alleles. CONCLUSIONS: Certain alleles of the short tandem repeat polymorphism of the dopamine receptor D2 gene reduce the risk of developing peak-dose dyskinesias and could contribute to varying susceptibility to develop peak-dose dyskinesias during levodopa therapy.

Influence of the anesthetic 2,6-diisopropylphenol on the oxidative phosphorylation of isolated rat liver mitochondria.

Isolated rat liver mitochondria have been incubated in the presence of the general anesthetic 2,6-diisopropylphenol (0-100 microM) and the efficiency of oxidative phosphorylation has been evaluated by measuring the respiratory rates, the rates of ATP synthesis or hydrolysis and the magnitude of the transmembrane electrical potential. The results obtained indicate that: (a) in mitochondria energized either by succinate or by ATP, 2,6-diisopropylphenol decreased the transmembrane electrical potential and increased the rates of either electron transfer or ATP hydrolysis; (b) in succinate-energized mitochondria 2,6-diisopropylphenol, at concentrations causing substantial depression of the transmembrane electrical potential, did not modify either the rate of phosphorylation of added ADP or the rate of ADP-stimulated respiration: (c) in succinate-energized mitochondria 2,6-diisopropylphenol caused a concentration-dependent inhibition of the uncoupler-stimulated rate of succinate oxidation. These findings suggest that under the experimental conditions reported 2,6-diisopropylphenol affected the generation and/or maintenance of the transmembrane electrical potential while leaving unchanged the coupling between the electron flow in the respiratory chain and the synthesis of ATP.

Energetic behaviour of mitochondria isolated from rat livers perfused with a perfluorodecalin + N,N-perfluorodiethylcyclohexylamine emulsion.

Rat livers have been perfused with a saline control medium or with a perfluorocarbon emulsion containing perfluorodecalin and N,N-perfluorodiethylcyclohexylamine, and the respiratory rates and transmembrane electrical potentials of mitochondria isolated following perfusion have been evaluated. The results indicate that the perfluorocarbon emulsion used, by providing a good oxygen supply to the perfused liver, allowed to preserve the efficiency of mitochondrial oxidative phosphorylation.

L-carnitine effect on halothane-treated mitochondria.

Addition of halothane to the incubation medium is shown to lower respiratory control and transmembrane potential and to increase ATPase activity in isolated rat liver mitochondria. Evidence is presented that L-carnitine is able to substantially decrease the negative effects of halothane on the energy-linked processes of mitochondria. The effects of halothane and the protective action of L-carnitine are discussed in the light of a possible involvement of long-chain acyl CoA in the unpairing of mitochondrial energy-linked functions.

Apolipoprotein E polymorphisms and Parkinson's disease.

The apolipoprotein E (APOE) gene polymorphism has been studied in Parkinson's disease (PD) with conflicting results. Recently, a newly described functional polymorphism in the regulatory region of the APOE gene, (-491 A/T), has been associated with late-onset Alzheimer's disease. We studied the association between these two polymorphisms of the APOE gene with PD in a sample of 126 PD patients and in 119 controls from the same geographic background. Allelic and genotypic frequencies were not different between PD cases and population controls for either the APOE or -491 A/T polymorphism. The age at onset of the disease was not different according to the specific genotypes of the two polymorphisms of the APOE gene.

Biochemical and morphological observations on rat liver and kidneys six months after intravenous injection of a perfluorocompound emulsion.

The histological appearance of liver and kidneys and the energy metabolism of isolated liver and kidney mitochondria were evaluated in rats 6 months after intravenous administration of 1 ml of a perfluorocompound emulsion. Both liver and kidney specimens showed neither significant histological alteration nor the presence of intracytoplasmic perfluorocompound particles. A substantial depression of the rate of ATP synthesis was observed both in liver and kidney isolated mitochondria (with respect to control mitochondria) although the magnitude of the transmembrane electrical potential was unaltered. The depression of ATP synthesis in mitochondria isolated from perfluorocompound-treated rats appeared then unrelated to the presence of perfluorocompound micelles within the cells, and might result from the interaction of either the perfluorocompound or the emulsifying agent with the mitochondrial ATP synthetase.

Influence of the anesthetic 2,6-diisopropylphenol (propofol) on isolated rat heart mitochondria.

The influence of the anesthetic 2,6-diisopropylphenol on isolated rat heart mitochondria has been investigated at a range of concentrations encompassing high and low clinical values. Low clinical concentrations of the anesthetic appeared unable to affect both oxidative phosphorylation and calcium homeostasis. 2,6-diisopropylphenol at high clinical levels decreased both the transmembrane electrical potential and the synthesis of ATP, while leaving mitochondrial calcium homeostasis unaffected. The results obtained suggest that isolated heart mitochondria are substantially insensitive to low clinical concentrations of 2,6-diisopropylphenol, thus largely excluding the possibility that mitochondrial alterations might be involved in the cardiac depression induced by this anesthetic.

Pantethine and pantothenate effect on the CoA content of rat liver.

The role of pantethine as a precursor of CoA in rat liver has been examined. It has been demonstrated that pantethine induces a significant increase in the total CoA content both in perfused liver and in liver homogenate, while it fails to affect the mitochondrial CoA content when added to isolated mitochondria. Pantethine is more efficient than pantothenate in inducing the synthesis of CoA in rat liver, even in the presence of added cysteine. The possible metabolic implications are discussed.

Carnitine effect on heart steatosis induced in rats by rapeseed oil.

Myocardial triglyceride levels in rats fed a high erucic acid rapeseed oil diet for three days were five times higher than in controls. The incorporation of erucic acid and, to a lower extent, some unsaturated fatty acids was increased, as well as total cholesterol content, compared to controls. The presence of 5% carnitine in the diet partially prevented these effects. It is assumed that carnitine may be a rate limiting factor in the myocardial catabolism of unsaturated fatty acids and particularly erucic acid, when these substance are ingested in supraoptimal amount.

Chorea induced by non-ketotic hyperglycaemia: a case report.

We describe an 81-year-old woman presenting with sudden onset of generalised chorea. She was unaware of suffering from diabetes. Laboratory screening revealed non-ketotic hyperglycaemia. Brain magnetic resonance imaging (MRI) failed to show basal ganglia abnormalities. Monotherapy with subcutaneous regular insulin induced a progressive normalisation of glycaemia as well as a parallel improvement of the abnormal involuntary movement scale on a nine-day sequential observation. This correlation strongly supports the hypothesis that non-ketotic hyperglycaemia itself might play a major pathogenetic role in chorea associated with non-ketotic hyperglycaemia. Diabetes mellitus should be suspected in patients who develop sudden onset of chorea even in the absence of putaminal abnormalities on MRI.

Diamide effect on the ouabain-insensitive APTase activity of red cell membrane.

Membranes from human erythrocytes exhibit a marked decrease of the ouabain-insensitive ATPase activity and of the total membrane thiol content after treatment with diazenedicarboxylic acid bis(N,N-dimethylamide) (diamide). These effects increase with diamide concentrations up to 2-2.5 mM and are persistent after removal of the reagent. Treatment with 2,3-dihydroxy-1,4-dithiolbutane (dithioerythritol or DTE) reduced glutathione or 2-mercaptoethanol partially but significantly restores at about the same extent the ouabain-insensitive ATPase activity. These results indicate that the perturbation of the ATPase microenvironment caused by membrane thiol oxidation is at good extent responsible for alterations of the divalent cation-dependent ATPase activity.

Diamide effect on the hypertonic calcium uptake by rat red blood cells.

Red blood cells of rat exhibit an enhanced hypertonic calcium uptake after incubation with diazenedicarboxylic acids bis (N,N-dimethylamide) (diamide). Over the ranges reported in this paper the amount of membrane alteration is strongly and linearly dependent on the diamide concentration and on the osmolarity of the incubation medium. Treatment with 2,3-dihydroxy-1,4-dithiolbutane (dithioerythritol or DTE), after diamide removal, restores red blood cells calcium intake to values similar to those of the control. The results indicate that the sinergic action of diamide and hypertonicity can oxidize some thiol groups essential for the cation barrier maintenance.

Effects of halothane, enflurane and isoflurane on some energy-converting functions of isolated rat liver mitochondria.

Enflurane and isoflurane appeared equally effective in decreasing the efficiency of oxidative phosphorylation in isolated mitochondria, while halothane was twice as effective as these two anesthetics. On the other hand enflurane and isoflurane exhibited different dose-response relationships when the uptake of calcium was measured (with a calcium-selective electrode) or the transmembrane electrical potential was monitored (with tetraphenylphosphonium-selective electrode) during ATP synthesis or calcium uptake in anesthetic treated mitochondria. The results indicate that the effects of isoflurane and enflurane on the mitochondrial energy converting processes are qualitatively, but not quantitatively, analogous to those previously described for halothane. Moreover the damaging action of isoflurane gradually increases as the anesthetic concentration increases, while that of enflurane suddenly increases above a threshold concentration. It appears that the effects of halothane, enflurane and isoflurane on isolated mitochondria involve both the ATP synthetase and the inner membrane permeability barrier, although the membrane-anesthetic interactions responsible for such effects are probably different for each anesthetic.