Salivary Urease and ADS Enzymatic Activity as Endogenous Protection against Dental Caries in Children.

UNLABELLED: The aim of this cross sectional study was to evaluate the ureolytic and arginolytic activities of saliva in children and associate them with their caries status. STUDY DESIGN: 65, 8 year old children, were randomly selected. The ureolytic and arginolytic activity of non stimulated saliva was studied and associated with DMFT and dmft index. Saliva of children were sampled under fasting conditions; Children refrained from any oral hygiene procedures during the 12 hours that preceded the sample collection. Caries activity was scored and divided in 3 groups: Group A: Index zero: without lesions; Group B: Moderate Index: 1 to 3 enamel caries lesions; and Group C: High Index: more than 4 dentin caries lesions. RESULTS: DMFT scores were moderate: 0.4(±0.79) and dmft: 2.78(±2.45). Results expressed in µmol/min/mg/protein, for urease activity were statistically significant (p=0.048): Group A= 0.69 (±0.7); Group B= 0.45 (±0.43); and Group C= 0.39 (±0.55). The arginine deiminase activity was not statistically significant (p=0.16): Group A= 2.53 (±1.42), Group B= 2.31 (±1.57) and Group C= 1.97 (±2.0). CONCLUSION: Higher levels of ureolytic (statistically significant) and arginolytic activity (trend) in saliva were associated with lower DMFT/dmft scores in 8 year old children. There was a higher production of ammonia from the arginine deiminase system than the urease enzyme in saliva (p>0.05).

Increased susceptibility to kainic acid-induced seizures in Engrailed-2 knockout mice.

The En2 gene, coding for the homeobox-containing transcription factor Engrailed-2 (EN2), has been associated to autism spectrum disorder (ASD). Due to neuroanatomical and behavioral abnormalities, which partly resemble those observed in ASD patients, En2 knockout (En2(-/-)) mice have been proposed as a model for ASD. In the mouse embryo, En2 is involved in the specification of midbrain/hindbrain regions, being predominantly expressed in the developing cerebellum and ventral midbrain, and its expression is maintained in these structures until adulthood. Here we show that in the adult mouse brain, En2 mRNA is expressed also in the hippocampus and cerebral cortex. Hippocampal En2 mRNA content decreased after seizures induced by kainic acid (KA). This suggests that En2 might also influence the functioning of forebrain areas during adulthood and in response to seizures. Indeed, a reduced expression of parvalbumin and somatostatin was detected in the hippocampus of En2(-/-) mice as compared to wild-type (WT) mice, indicating an altered GABAergic innervation of limbic circuits in En2(-/-) mice. In keeping with these results, En2(-/-) mice displayed an increased susceptibility to KA-induced seizures. KA (20 mg/kg) determined more severe and prolonged generalized seizures in En2(-/-) mice, when compared to WT animals. Seizures were accompanied by a widespread c-fos and c-jun mRNA induction in the brain of En2(-/-) but not WT mice. Long-term histopathological changes (CA1 cell loss, upregulation of neuropeptide Y) also occurred in the hippocampus of KA-treated En2(-/-) but not WT mice. These findings suggest that En2(-/-) mice might be used as a novel tool to study the link between epilepsy and ASD.

Shall we operate? Preoperative assessment in elderly cancer patients (PACE) can help. A SIOG surgical task force prospective study.

BACKGROUND: A number of elderly cancer patients do not receive standard surgery for solid tumors because they are considered unfit for treatment as a consequence of inaccurate estimation of the operative risk. To tailor treatment to onco-geriatric series, oncologists are now beginning to use a comprehensive geriatric assessment (CGA). This study investigates the value of an extended CGA in assessing the suitability of elderly patients for surgical intervention. PATIENTS AND METHODS: Preoperative assessment of cancer in the elderly (PACE) incorporates validated instruments including the CGA, an assessment of fatigue and performance status and an anaesthesiologist's evaluation of operative risk. An international prospective study was conducted using 460 consecutively recruited elderly cancer patients who received PACE prior to elective surgery. Mortality, post-operative complications (morbidity) and length of hospital stay were recorded up to 30 days after surgery. RESULTS: Poor health in relation to disability (assessed using the instrumental activities of daily living (IADL)), fatigue and performance status (PS) were associated with a 50% increase in the relative risk of post-operative complications. Multivariate analysis identified moderate/severe fatigue, a dependent IADL and an abnormal PS as the most important independent predictors of post-surgical complications. Disability assessed by activities of daily living (ADL), IADL and PS were associated with an extended hospital stay. CONCLUSION: PACE represents a valuable tool in enhancing the decision process concerning the candidacy of elderly cancer patients for surgical intervention and can reduce inappropriate age-related inequity in access to surgical intervention. It is recommended that PACE be used routinely in surgical practice.

CYP 2E1 mutant mice are resistant to DDC-induced enhancement of MPTP toxicity.

In order to reach a deeper insight into the mechanism of diethyldithiocarbamate (DDC)-induced enhancement of MPTP toxicity in mice, we showed that CYP450 (2E1) inhibitors, such as diallyl sulfide (DAS) or phenylethylisothiocyanate (PIC), also potentiate the selective DA neuron degeneration in C57/bl mice. Furthermore we showed that CYP 2E1 is present in the brain and in the basal ganglia of mice (Vaglini et al., 2004). However, because DAS and PIC are not selective CYP 2E1 inhibitors and in order to provide direct evidence for CYP 2E1 involvement in the enhancement of MPTP toxicity, CYP 2E1 knockout mice (GONZ) and wild type animals (SVI) of the same genetic background were treated with MPTP or the combined DDC + MPTP treatment. In CYP 2E1 knockout mice, DDC pretreatment completely fails to enhance MPTP toxicity, although enhancement of MPTP toxicity was regularly present in the SVI control animals. The immunohistochemical study confirms our results and suggests that CYP 2E1 may have a detoxifying role.

Pre-operative assessment of cancer in the elderly (PACE): a comprehensive assessment of underlying characteristics of elderly cancer patients prior to elective surgery.

BACKGROUND: Cancer is a disease that particularly affects the elderly and, although surgery is the first treatment choice, many elderly cancer patients do not receive standard surgery because they are considered unfit for treatment due to an inaccurate estimation of operative risk. Pre-operative Assessment of Cancer in the Elderly (PACE) was developed in order to address the need to provide detailed information about the functional reserve of the elderly cancer patient to aid individualised management. METHODS: PACE incorporates a battery of validated instruments including the Comprehensive Geriatric Assessment (CGA), Brief Fatigue Inventory (BFI), Eastern Cooperative Oncology Group Performance Status (ECOG-PS), and American Society Anesthesiologists (ASA) grade. An international prospective study was conducted with 460 consecutive elderly cancer patients (216 breast, 146 GIT, 71 GUT, 27 other) receiving PACE prior to receiving elective surgery. RESULTS: Three hundred and eighty four patients (83.4%) were observed to have at least one co-morbidity; the most common being hypertension (n=246, 53.5%). More than two thirds of the patients had good functional and mental status according to PACE. After adjusting for age, sex and type of cancer, six of the seven items of PACE were found to be significantly associated with co-morbidities (according to the Satariano's Index of Co-morbidities (SIC)). A multivariate analysis identified IADL, BFI and ASA to be the most important instruments in explaining SIC. DISCUSSION: PACE has been effectively used to describe the functional capacity and health status in an international cohort of elderly cancer patients. The majority of PACE instruments have been found to be significantly associated with co-morbidities (SIC) and can distinguish between type and severity of cancer. PACE represents a useful tool in evaluating onco-geriatric fitness for surgery.

Assessing neuroprotection in Parkinson's disease: from the animal models to molecular neuroimaging in vivo.

An important goal in Parkinson's Disease research is to identify neuroprotective therapy, and the interaction between basic science and clinical research is needed to discover drugs that can slow or halt the disorder progression. At present there is not a perfect animal model of PD to test neuroprotective strategies, however the models that portray the basic characteristics needed are toxin-induced and gene-based models. The first group comprehends 6-OHDA e MPTP and recently rotenone, paraquat and epoxomicin treated animals that shows some of human disease characteristics. Gene-based models are various and, even if with limits, they seem suitable models to test neuroprotection in PD since they present replicable lesions, a predictable pattern of neurodegeneration and a well-characterized behavior, biochemistry and morphology to assist in the understanding of induced changes. In clinical trials researchers have first used as marker of disease progression clinical scores and motor tasks which are limited by the potential symptomatic effect of tested drugs and are not useful in the pre-clinical phases of PD. Recently has emerged the important role of neuroimaging (Dopamine Transporter SPECT, 18FDopa-PET) as surrogate biomarker of PD progression. Even if there are still concerns about the influence of regulatory effects of tested drugs, neuroimaging features could represent a good outcome measure to evaluate PD progression and putative neuroprotective effect of pharmacological and non-pharmacological manipulations.

Cytochrome P450 and Parkinson's disease: protective role of neuronal CYP 2E1 from MPTP toxicity.

Elucidation of the biochemical steps leading to the 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine (MPTP)-induced degeneration of the nigro-striatal dopamine (DA) pathway has provided new clues to the pathophysiology of Parkinson's Disease (PD). In line with the enhancement of MPTP toxicity by diethyldithiocarbamate (DDC), here we demonstrate how other CYP450 (2E1) inhibitors, such as diallyl sulfide (DAS) or phenylethylisothiocyanate (PIC), also potentiate the selective DA neuron degeneration in C57/bl mice. In order to provide direct evidence for this isozyme involvement, CYP 2E1 knockout mice were challenged with MPTP or the combined treatment. Here we show that these transgenic mice have a low sensitivity to MPTP alone, similarly to the wild type SVI, suggesting that it is likely that transgenic mice compensate for the missing enzyme. However, in these CYP 2E1 knockout mice, DDC pretreatment completely fails to enhance MPTP toxicity; this enhancement is instead regularly present in the SVI control animals. This study indicates that the occurrence of CYP 2E1 in C57/bl mouse brain is relevant for MPTP toxicity, and suggests that this isozyme may have a detoxificant role related to the efflux transporter of the toxin.

Structure and expression of a laccase gene from the ligninolytic basidiomycete Ceriporiopsis subvermispora.

A gene encoding laccase has been isolated from a genomic library of the white-rot basidiomycete Ceriporiopsis subvermispora constructed in Lambda GEM-11. This gene (Cs-lcs1) contains an open reading frame of 2215 bp, encoding a mature protein of 499 amino acids with a 21-residue signal peptide. The protein sequence exhibits between 63 and 68% identity with laccases from other basidiomycetes and shares with all of them 10 conserved histidines and one cysteine involved in the coordination of copper atoms at the active site of the enzyme. The gene possesses 11 introns, with splicing junctions and internal lariat formation sites adhering to the GT-AG and CTRAY rules, respectively. The upstream region of Cs-lcs1 contains a TATA box, two CAAT sites, five putative metal response elements and a ACE1 element. In agreement with the presence of the latter element, transcription of Cs-lcs1 is activated by copper and silver, as shown by Northern blot and reverse transcription followed by DNA amplification analyses. Based on Southern blot analysis, Cs-lcs1 appears to be the only gene encoding laccase in C. subvermispora.

Characterization of three new manganese peroxidase genes from the ligninolytic basidiomycete Ceriporiopsis subvermispora.

Three new genes (Cs-mnp2A, Cs-mnp2B and Cs-mnp3) coding for manganese-dependent peroxidase (MnP) have been identified in the white-rot basidiomycete Ceriporiopsis subvermispora. The mature proteins contain 366 (MnP2A and MnP2B) and 364 (MnP3) amino acids, which are preceded by leader sequences of 21 and 24 amino acids, respectively. Cs-mnp2A and Cs-mnp2B appear to be alleles, since the corresponding protein sequences differ in only five residues. The upstream region of Cs-mnp2B contains a TATA box, AP-1 and AP-2 sites, as well as sites for transcription regulation by metals (two), cAMP (two) and xenobiotics (one). Some of these elements are also found in the regulatory region of Cs-MnP3. Transcription of Cs-mnp2A and Cs-mnp2B, but not that of Cs-mnp3, is activated by manganese.

Species differences in the role of excitatory amino acids in experimental parkinsonism.

The present review discusses species differences in relation to the effects produced by the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP); in particular, it focuses on recent evidence regarding the role of excitatory amino acids in experimental parkinsonism. The main aim of the review is to provide a phylogenetic perspective which may serve as a useful tool to study Parkinson's disease in rodents. Excitotoxicity might represent the final common pathway on which the actions of different neurotoxins, selectively directed towards nigrostriatal dompaminergic neurons, converge. This is clearly demonstrated in methamphetamine- and 6-dihydroxy-dopamine-induced parkinsonism. The role of excitotoxicity in the mechanism of action of MPTP is less clear. Although there are several species differences for MPTP it is possible to obtain in mice the same effects induced in MPTP-treated primates by combining acetaldehyde or diethyldithiocarbamate with MPTP administration. When mice are administered these combined treatments, the onset of experimental parkinsonism can be prevented using the same pharmacological agents (i.e. glutamate N-methyl-D-aspartate antagonists) that are effective in primates.

Gamma-amino-beta-hydroxy butyric acid stimulates prolactin and growth hormone release in normal women.

The influence of gamma-amino-beta-hydroxy butyric acid (GABOB) treatment on pituitary function has been investigated in this study. Different doses (50 x 100 mg) of GABOB were iv injected into three and six normal women, respectively. PRL and GH plasma levels were measured before and after the injection. The treatment with 150 mg GABOB, performed in another two normal women, was interrupted because of side-effects (loss of consciousness etc.) due to the treatment. The treatment with 50 mg GABOB did not induce significant variations of the two hormones; however, significant increases of PRL (P less than 0.05) and GH (P less than 0.01) plasma levels were observed after injection with 100 mg GABOB. The present data suggest that gamma-amino butyric acid (GABA) itself of GABAergic drugs might play an important role in the control of hypothalamic-pituitary function.

Apomorphine hydrochloride-induced improvement in Huntington's chorea: stimulation of dopamine receptor.

Four patients affected by Huntington's chorea (HC) with a well defined family history of the disease were injected intramuscularly with apomorphine hydrochloride in nonemetic doses, ranging from 1 to 4 mg. Soon after treatment, all patients showed a marked decrease in abnormal involuntary movements. Pretreatment with haloperidol (2 mg intramuscularly) or sulpiride (100 mg intramuscularly) 30 minutes prior to apomorphine treatment, prevented the therapeutic effect of this compound. It is suggested that apomorphine-induced improvement in Huntington's Chorea is mediated by the stimulation of a special kind of dopamine receptor, leading to inhibition of the activity of dopaminergic neurons.

Therapeutic experience with transdihydrolisuride in Huntington's disease.

Transdihydrolisuride is an ergot derivative with mixed agonist and antagonist effects on central dopamine receptors. We gave the drug orally (1 mg daily) to 10 patients with Huntington's disease. In seven patients, the chorea improved with no adverse effects during the study.

Dopaminergic mechanisms in hemiparkinsonian monkeys.

The motor effects of direct agonists which act selectively on certain dopamine receptors were studied in monkeys rendered hemiparkinsonian by unilateral intracarotid injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The D-2 dopamine agonist, LY 171555, but not the D-1 agonist, SKF 38393, reduced parkinsonian signs and induced rotation away from the side of the nigral lesion. When administered together, SKF 38393 diminished the LY 171555-induced turning in a dose-dependent manner. A selective D-1 antagonist, SCH 23390, induced mild and brief rotation when administered alone. These results suggest that D-2 receptor stimulation is necessary to ameliorate parkinsonism, but that pharmacologic manipulation of both D-1 and D-2 receptors may be required for an optimal therapeutic response.

Localization of a glutathione-dependent dehydroascorbate reductase within the central nervous system of the rat.

In this study, we describe for the first time the occurrence, within the central nervous system of the rat, of a dehydroascorbate reductase analogous to the one we recently described in the liver. Dehydroascorbate reductase plays a pivotal role in regenerating ascorbic acid from its oxidation product, dehydroascorbate. In a first set of experiments, we showed that a dehydroascorbate reductase activity is present in brain cytosol; immunoblotting analysis confirmed the presence of an immunoreactive cytosolic protein in selected brain areas. Immunotitration showed that approximately 65% of dehydroascorbate reductase activity of brain cytosol which was recovered in the ammonium sulphate fraction can be attributed to this enzyme. Using immunohistochemistry, we found that a variety of brain areas expresses the enzyme. Immunoreactivity was confined to the gray matter. Amongst the several brain regions, the cerebellum appears to be the most densely stained. The enzyme was also abundant in the hippocampus and the olfactory cortex. The lesion of norepinephrine terminals following systemic administration of DSP-4 markedly decreased immunoreactivity in the cerebellum. Apart from the possible co-localization of the enzyme with norepinephrine, the relative content of dehydroascorbate reductase in different brain regions might be crucial in conditioning regional sensitivity to free radical-induced brain damage. Given the scarcity of protective mechanisms demonstrated in the brain, the discovery of a new enzyme with antioxidant properties might represent a starting-point to increase our knowledge about the antioxidant mechanisms operating in several central nervous system disorders.

Effects of thrombolysis and atenolol or metoprolol on the signal-averaged electrocardiogram after acute myocardial infarction. Late Potentials Italian Study (LAPIS).

Late potentials (LPs) detected on the signal-averaged (SA) electrocardiogram (ECG) predict arrhythmic events after acute myocardial infarction (AMI). The effect of thrombolysis on the incidence of LPs after AMI is controversial and its impact on subsequent arrhythmic events is not known. Moreover, the effects of beta blockers on the SAECG have not been studied. Six hundred eighteen patients with AMI were studied; thrombolysis was given to 228 (37%). In comparison with patients treated conventionally, those receiving thrombolysis were significantly younger and more frequently male, had higher peak values of creatine kinase, a lower prevalence of non-Q-wave AMI, and a higher incidence of ventricular fibrillation in the acute phase, and more frequently received beta blockers. An SAECG obtained 6 to 8 days after AMI showed LPs in 24% of patients receiving and in 25% not receiving thrombolysis (p = NS). On admission, intravenous beta blockers were administered to 110 patients (18%); those receiving beta blockers were younger, had lower peak values of creatine kinase and more frequently received thrombolysis. LPs were less frequently found in patients treated than in those not treated with beta blockers (15 vs 27%; p = 0.007); however, this effect was found only in those with an ejection fraction > or = 40%. Independent predictors of LPs by multivariate analysis were an ejection fraction < 40% (p = 0.007), ventricular fibrillation in the acute phase (p = 0.02), and absence of beta-blocking therapy (p = 0.03). During a mean follow-up of 12 +/- 7 months, there were 39 cardiac deaths (6%), 13 of which were sudden (2%), and 9 sustained ventricular tachycardias.(ABSTRACT TRUNCATED AT 250 WORDS)

Covalent protein binding of a metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine to mouse and monkey brain in vitro and in vivo.

We have recently reported that a reactive metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is formed in rat brain in vitro by type B monoamine oxidase (MAO). In the present study, we further characterize the irreversible binding in vitro using tissues from mice and monkeys, two species more sensitive than rats to MPTP neurotoxicity. We also report the occurrence of irreversible binding of radioactivity after administration of tritiated MPTP in the same species in vivo. Tissue homogenates were incubated at 37 degrees with 1-[methyl-3H]MPTP in in vitro experiments. Animals were injected with labeled MPTP and sacrificed at different times in in vivo experiments. The perchloric acid precipitates of tissue homogenates from either procedure were washed exhaustively with organic solvents and counted for radioactivity. The amount of recovered radioactivity in in vitro experiments was similar using brain homogenates from mice and monkeys, whereas a considerably lower amount was found in mouse liver. MAO-B inhibitors decreased the covalent binding. However, the combined MAO-B/MAO-A inhibitor pargyline had no effect if added after 2 hr of incubation. Sulfhydryl-containing compounds decreased the covalent binding in a concentration-related manner. GSH reduced the rate of the reaction throughout the incubation. The covalent binding slowly increased in time in vivo in mouse brain, not in liver. There was a two-fold variation of covalently bound radioactivity in different brain areas of 3H2-MPTP-treated monkey. This reactive metabolite may play a role in MPTP neurotoxicity.

MPTP fails to induce lipid peroxidation in vivo.

It has been speculated that the conversion of MPTP to MPP+ destroys dopaminergic neurons by promoting the generation of hydroxyl radicals and causes lipid peroxidation. The results obtained in the present work indicate that the primary products of lipid peroxidation are not detectable in MPTP treated animals and thus other mechanisms besides lipid peroxidation should be considered to explain the cytotoxicity of this neurotoxin.

Increased paroxysmal activity of partial seizures in man by apomorphine.

In order to study the role of dopamine (DA) in the regulation of seizure mechanisms in man, a non-emetic dose of apomorphine, a direct stimulant of DA receptors, was administered to eight patients effected by different types of epilepsy. The EEG changes induced by apomorphine administration in comparison to those elicited by promazine or placebo were evaluated in a double blind cross-over study. Similarly to promazine treatment, apomorphine worsened the EEG recordings of some patients. The apomorphine-induced increase in paroxysmal activity was observed in patients affected by partial epilepsy and was not related to the sleep-inducing properties of the drug. This effect is interpreted as being the result of a stimulation of DA autoreceptors, mediating a decrease of dopaminergic activity in the central nervous system. The use of apomorphine as an EEG activating agent is suggested.

Parkinsonism by haloperidol and piribedil.

Three groups of schizophrenic patients were treated with haloperidol, with a low dose of piribedil (a dopamine agonist), and with a combination of the two treatments, respectively. After a few days, all 7 patients treated with the drug combination showed marked rigidity and akinesia, while patients treated with haloperidol alone (4) and piribedil alone (4) showed either mild or no symptoms of parkinsonism. The drug combination induced mainly an akinetic-hypertonic syndrome, while tremors were absent or mild. The results suggest that low doses of the DA-agonist potentiate the extrapyramidal side effects of haloperidol by acting on self-inhibitory DA receptors, thereby blocking the compensatory increase in dopaminergic firing elicited by the neuroleptic agent.