Antibiofilm Activity of Eugenol-Loaded Chitosan Coatings against Common Medical-Device-Contaminating Bacteria

The formation of pathogenic biofilms on medical devices is a major public health concern accounting for over 65% of healthcare-associated infections and causing high infection morbidity, mortality, and a great burden to patients and the healthcare system due to its resistance to treatment. In this study, we developed a chitosan-based antimicrobial coating with embedded mesoporous silica nanoparticles (MSNs) to load and deliver eugenol, an essential oil component, to inhibit the biofilm formation of common bacteria in medical-device-related infections. The eugenol-loaded MSNs were dispersed in a chitosan solution, which was then cross-linked with glutaraldehyde and drop-casted to obtain coatings. The MSNs and coatings were characterized by dynamic light scattering, Brunauer-Emmett-Teller analysis, attenuated-total-reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, 3D optical profilometry, and scanning electron microscopy. The release behavior of eugenol-loaded MSNs and coatings and the antibiofilm and antimicrobial activity of the coatings against adherent Staphylococcus aureus, methicillin-resistant S. aureus, and Pseudomonas aeruginosa were investigated. Eugenol was released from the MSNs and coatings in aqueous conditions in a controlled manner with an initial low release, followed by a peak release, a decrease, and a plateau. While the chitosan coatings alone or with unloaded MSNs demonstrated limited antimicrobial effects and still supported biofilm formation after 24 h, the coating containing eugenol not only reduced biofilm formation but also killed the majority of the attached bacteria. It also showed biocompatibility in indirect contact with NIH/3T3 fibroblasts and a high percentage of live cells in direct contact. However, further investigations into cell proliferation in direct contact are recommended. The findings indicated that the chitosan-based coating with eugenol-loaded MSNs could be developed into an effective strategy to inhibit biofilm formation on medical devices.

Waterborne disease outbreaks in treated recreational water facilities: a Socio-Ecological Model perspective

Treated recreational water facilities, including swimming pools and water play parks, have often been implicated in infectious disease outbreaks. Addressing this problem is complex due to the multiple and interrelated factors contributing to outbreaks in these settings. These factors may relate to inappropriate behaviours of users and operators, lack of and inconsistent regulation of these facilities, insufficient facility maintenance, and problems associated with the design of these facilities. Given the complexity of this issue, we argue that the Socio-Ecological Model (SEM) provides a useful framework to help identify the multi-level influences and factors that have implications for designing interventions to prevent this public health problem, whilst assisting in guiding future research in this area. We apply the SEM to the current literature to help identify the influences and factors contributing to infectious disease outbreaks in treated recreational water facilities to support this argument. We also identify several gaps in the existing research that would benefit from further examination to help prevent infectious disease outbreaks in treated recreational water facilities such as public swimming pools and water play parks.

Oxaliplatin-induced changes in microbiota, TLR4+ cells and enhanced HMGB1 expression in the murine colon

Oxaliplatin is a platinum-based chemotherapeutic used for cancer treatment. Its use associates with peripheral neuropathies and chronic gastrointestinal side-effects. Oxaliplatin induces immunogenic cell death by provoking the presentation of damage associated molecular patterns. The damage associated molecular patterns high-mobility group box 1 (HMGB1) protein exerts pro-inflammatory cytokine-like activity and binds to toll-like receptors (namely TLR4). Gastrointestinal microbiota may influence chemotherapeutic efficacy and contribute to local and systemic inflammation. We studied effects of oxaliplatin treatment on 1) TLR4 and high-mobility group box 1 expression within the colon; 2) gastrointestinal microbiota composition; 3) inflammation within the colon; 4) changes in Peyer's patches and mesenteric lymph nodes immune populations in mice. TLR4+ cells displayed pseudopodia-like extensions characteristic of antigen sampling co-localised with high-mobility group box 1 -overexpressing cells in the colonic lamina propria from oxaliplatin-treated animals. Oxaliplatin treatment caused significant reduction in Parabacteroides and Prevotella1, but increase in Prevotella2 and Odoribacter bacteria at the genus level. Downregulation of pro-inflammatory cytokines and chemokines in colon samples, a reduction in macrophages and dendritic cells in mesenteric lymph nodes were found after oxaliplatin treatment. In conclusion, oxaliplatin treatment caused morphological changes in TLR4+ cells, increase in gram-negative microbiota and enhanced HMGB1 expression associated with immunosuppression in the colon.

Role of the informed consent, from mesotherapy to opioid therapy

Informed consent is part of a process of communication useful to obtain an agreement (conscious, voluntary and free) between doctors and patients. Mesotherapy is based on the introduction of drugs by intradermal route in order to obtain a dose-sparing effect with respect to deeper administration. Opioids are the most appropriate therapy for patients who do not respond to other therapies. Proper communication between doctor and patient, including an explanation of the potential benefits, limitations and risks (even mild), is recommended both in clinical practice and research. Active participation of the patient has the advantage of better control of adverse events, both of mesotherapy and opioid-based therapy. This information-education process returns to the fundamental concept of "first do no harm" and set a "therapeutic partnership" with patients.

Reverse perfusion pattern in myocardial spect with 99mTc-sestaMIBI

RATIONALE

The aim of our study was to investigate the myocardial perfusion deficit in rest images as compared to stress images in myocardial scintigraphy (MS).

OBJECTIVES

The aim of this study is to investigate the reverse perfusion (RP) pattern in MS.

METHODS AND RESULTS

263 patients were enrolled in the study (72 females and 191 males; mean age 65.7 ± 9.5 years old). Mean body mass index (BMI) was of 27.6 ± 3.8 Kg/m2. 115 patients were positive for a previous history of myocardial infarction (MI). 142 patients reported a revascularization treatment (percutaneous transluminal coronary angioplasty, PTCA, cardiac stent placement, coronary artery bypass grafting, CABG). All the patients underwent MS following standard single day Stress/Rest protocol. In our series, 27 patients presented a RP pattern. We did not find statistically significant differences when considering age (p = 0.7988), sex (p = 0.0657), BMI (p = 0.8611), diabetes (p = 0.8259), dyslipidemia (p = 0.1464) or smoking status (p = 0.6829) in RP patients vs. non-RP patients. A history of MI is related to a RP pattern (p < 0.0001). A history of previous revascularization was not related with RP (p = 0.6868).

DISCUSSION

The result of our study suggested that RP is probably related to artifacts of various origins. Further studies are necessary especially in microvascular dysfunction or a long history of disease.

Astroviruses as causative agents of gastroenteritis

Astroviruses were first identified over 30 years ago and the virus was soon established as an important cause of gastroenteritis, particularly in young children. Human astrovirus disease was thought to result from infection by a limited number of serotypes. However, recent studies have indicated that the extent of genetic diversity is greater than previously assumed. In addition, the widespread occurrence among animals and reports of recombination and possible cross-species transmission suggest that astroviruses have zoonotic potential.

Measurement of the branching fractions of B-->D**(l) nu(l) decays in events tagged by a fully reconstructed B meson

We report a measurement of the branching fractions of B-->D**(l) nu(l), decays based on 417 fb(-1) of data collected at the Y(4S) resonance with the BABAR detector at the PEP-II e+e- storage rings. Events are selected by full reconstructing one of the B mesons in a hadronic decay mode. A fit to the invariant mass differences m(D(*) pi)- m(D(*)) is performed to extract the signal yields of the different D** states. We observe the B-->D**l(-1)nu(l) decay modes corresponding to the four D states predicted by heavy quark symmetry with a significance greater than 5 standard deviations including systematic uncertainties.

Genetic and antigenic characterization of rotavirus serotype G9 strains isolated in Australia between 1997 and 2001

Rotavirus serotype G9 is recognized as the most widespread of the emerging serotypes, emerging since 1996 as a frequent cause of severe acute gastroenteritis in children from many countries covering all continents of the world. This study characterized serotype G9 strains collected in three widely separated Australian centers from 1997 to 2001. All G9 strains possessed the VP4 P[8] and VP6 subgroup II genes. The overall prevalence of the G9 strains increased in Australia, from 0.6% of the strains found in 1997 to 29% of the strains found in 2001. The prevalence of G9 relative to all other serotypes varied from year to year and with geographic location. In Melbourne (representing east coast urban centers), G9 made up 11 to 26% of all of the strains found from 1999 to 2001. In Perth (representing west coast urban centers), G9 made up less than 2% of the strains found in 1997 to 2000 but increased to 18.6% of the strains found in 2001. In Alice Springs (representing widely dispersed settlements in northern arid regions), G9 made up 0 to 5% of the strains found from 1997 to 2000 and was the dominant strain in 2001, making up 68.9% of all of the strains found. Three distinct antigenic groups based on reaction with neutralizing monoclonal antibodies (N-MAbs) were identified, including a dominant group (63%) that cross-reacted with the serotype G4 N-MAb. Phylogenetic analysis of the VP7-encoding gene from Australian strains, compared with a worldwide collection of G9 strains, showed that the Australian G9 strains made up a genetic group distinct from other serotype G9 strains identified in the United States and Africa. Future epidemiological studies of the occurrence of G9 strains should combine reverse transcription-PCR and typing with G1 to G4 and G9 N-MAbs to determine the extent of G9 and G4 cross-reactions among rotavirus strains, in order to assess the need to incorporate G9 strains into new candidate vaccines.

Annual report of the Rotavirus Surveillance Programme, 1999/2000

The National Rotavirus Reference Centre has conducted rotavirus surveillance by means of a collaborative laboratory based initiative started in June 1999. The serotypes of rotaviruses that lead to the hospitalisation of children with acute diarrhoea were determined from June 1999 to May 2000. We examined 1126 rotavirus specimens using a combination of monoclonal antibody immunoassay, reverse transcription-polymerase chain reaction, and hybridisation. The four most common serotypes G1-G4 were represented. More than 50% of isolates tested were serotype G1, with serotype G1 being represented in most centres Australia-wide. Serotype G9 rotaviruses were identified for the first time in Australia, and were second in importance with 10% of samples tested. The significant presence of G9 viruses throughout Australia suggests the emergence of a new serotype and has implications for current rotavirus vaccine strategies that target serotypes G1-G4.

Extended excretion of rotavirus after severe diarrhoea in young children

BACKGROUND

Rotaviruses are the major cause of severe childhood diarrhoea. Knowledge of the natural history of infection, including duration of intestinal virus shedding, is important in the understanding of transmission, sources of infection, and immune responses.

METHODS

We carried out a study of rotavirus excretion in 37 children admitted to hospital with severe rotavirus diarrhoea. Sequential faecal specimens were collected from each child during 100 days of surveillance, and screened for rotavirus by EIA and by amplification of genome double-stranded RNA by reverse-transcription PCR. IgA coproantibody was estimated by EIA.

FINDINGS

Duration of rotavirus excretion ranged from 4 to 57 days after onset of diarrhoea. Excretion ceased within 10 days in 16 (43%) children, and within 20 days in 26 (70%) children. Extended excretion was detected for 25-57 days in the remaining 11 (30%) children owing mainly to continued excretion of the primary infecting strain. Extended excretion was significantly associated with antirotavirus IgA coproantibody boosts during 100 days of surveillance (p=0.001, log-rank test), and with recurrence of mild diarrhoea symptoms during convalescence (p=0.006, Fisher's exact test).

INTERPRETATION

Severe rotavirus disease in young children may be followed by extended excretion of rotavirus. The risk of transmission to others may be greater than previously believed. Extended excretion could also explain some cases of the postgastroenteritis syndrome.

Bone turnover and its relationship with bone mineral density in pre- and postmenopausal women with or without fractures

OBJECTIVE

This work was carried out in order to investigate possible relationships between bone turnover rate, as evaluated by bone biomarkers and skeletal mass, as evaluated by bone mineral density (BMD).

METHOD

Fifty-eight normal women and 30 female patients with osteoporotic fractures were enrolled. Three groups were defined: (1) fertile subjects (n = 24), mean age 33.7 +/- 8.1 years; (2) postmenopausal women (n = 32, including 11 patients with fractures) whose BMD values, in terms of T score, were less than -2.5 S.D. below the young adult mean obtained in our laboratory (mean age 61.7 +/- 7.9 years; and years since menopause (ysm), 12.6 +/- 8.3); (3) postmenopausal women (n = 32, including 19 patients with fractures) whose BMD values in terms of T score, were below -2.5 S.D. (mean age 62.9 +/- 8.6 years; and ysm 15.9 +/- 9.0). Groups II and III characterised, by inclusion criteria, by significant different mean BMD values, were similar as far as chronological and menopausal age were considered. Metabolic tests included a short urine collection to determine calcium, hydroxyproline, cross-linked N-telopeptides of type I collagen (NTx) and creatinine (Cr); half-way through this collection, a blood sample was taken for the measurement of total alkaline phosphatase activity (ALP) and tartrate-resistant acid phosphatase activity (TRAP). BMD at lumbar spine was evaluated.

RESULTS

There were significant differences amongst the three groups in mean ALP (P < 0.001, by analysis of variance) TRAP (P < 0.006) and NTx/Cr (P < 0.001) values, but not as far as mean values of calcium/Cr or hydroxyproline/Cr ratios were concerned. Considering the group as a whole, there were significant inverse correlations between NTx/Cr, ALP, TRAP and BMD controlling for both age (r = -0.392, P < 0.001; r = -0.447, P < 0.001 and r = -0.327, P < 0.002, respectively) and ysm (r = -0.374, P < 0.001; r = -0.474, P < 0.001 and r = -0.333, P < 0.002).

CONCLUSIONS

Our results indicate, that, even after controlling for both ageing and oestrogen status, there is an inverse relationship between bone mass (that at a given time represents the balance of all previous metabolic events) and a biochemical marker (which reflects bone turnover at the time of examination). These findings are in line with the belief that increased bone turnover should be regarded as a risk factor for osteoporosis. Furthermore, our results indicate that, unless there is no increase of hepatic isozyme, total ALP still maintains a possible role as a first analysis to evaluate bone turnover before requesting markers with greater specificity, sensitivity but also more expensive and whose analysis is sometimes time-consuming.

Analysis of sequence contexts flanking T.G mismatches leads to predictions about reactivity of the mismatched T to osmium tetroxide

Osmium tetroxide and hydroxylamine are used to detect mutations in DNA and RNA after hybridization of mutant and wild-type DNA. Mismatched T and C bases, respectively, are modified by these reagents and the DNA strand cleaved at the mismatched bases by subsequent treatment with piperidine. This allows detection and location of the mutation. Although most T.G mismatches have been reported to be reactive to osmium tetroxide, some have been reported to be unreactive. The aim of this study was to collect and analyze the reactive and unreactive T.G mismatches. We have collected sequence contexts of all reactive and unreactive T.G mismatches for analysis. This involves 10 unreactive T.G mismatches (plus one T.C) and 19 reactive T.G mismatches. Sequence effects of bases surrounding these mismatches must influence this reactivity. There must be many types of such sequence effects. We postulate that because of the dominance of 5' G bases near the T of unreactive T.G mismatches and the absence of 5' G bases in reactive T.G mismatches that the stacking of the 5' G on the mismatched T is the reason for this lack of reactivity in the majority of the cases studied here.

Cerebral metabolic effects of monoamine oxidase inhibition in normal and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine acutely treated monkeys

The neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induces dopaminergic cell death in the substantia nigra pars compacta (SNpc) and clinical parkinsonism in humans and experimental animals. Pretreatment with monoamine oxidase inhibitors prevents this cell death and associated parkinsonism by blocking the oxidation of MPTP to a toxic intermediate. The 2-deoxyglucose method was used to study the acute effects of MPTP in the monkey brain and the effects of monoamine oxidase inhibition on local cerebral glucose utilization in both normal and MPTP-treated monkeys. MPTP administration alone caused a major increase in glucose utilization in the SNpc and smaller increases in some subnuclei within the ventral tegmental area in which eventual dopaminergic cell loss also occurs. Pretreatment with pargyline abolished these metabolic increases, a finding suggesting both that the oxidized product of MPTP generates the metabolic increases and that the increased glucose consumption may contribute to cell toxicity. On the other hand, in most cortical, thalamic, striatal, brainstem, and cerebellar areas MPTP alone caused reductions in glucose utilization, and pargyline failed to prevent these effects. Pargyline alone depressed metabolism in the locus coeruleus and a few other monoaminergic structures.

Local cerebral glucose utilization in monkeys with hemiparkinsonism induced by intracarotid infusion of the neurotoxin MPTP

Quantitative 2-[14C]deoxyglucose autoradiography was used to map the pattern of alterations in local cerebral glucose utilization associated with unilateral lesions of the substantia nigra pars compacta produced by the infusion of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) into one internal carotid artery of rhesus monkeys. These monkeys become hemiparkinsonian, displaying rigidity, bradykinesia, and tremor of the limbs contralateral to the side of MPTP infusion; during spontaneous activity they turn toward the side of the lesion. Eighty-two brain areas were examined, and statistically significant metabolic changes were confined mainly to basal ganglia structures ipsilateral to the side of the lesion. Glucose utilization was reduced in the substantia nigra pars compacta and ventral tegmental area, i.e., in the areas of cell loss. Increases in glucose utilization in regions normally innervated by the lesioned area were observed in the post-commissural portions of the putamen and dorsolateral caudate. Other structures showing statistically significant metabolic changes were the external segment of the globus pallidus (+40%), subthalamic nucleus (-17%), and pedunculopontine nucleus (+15%). There were also smaller changes in portions of the thalamus (ventral anterior nucleus, parafascicular nucleus) and premotor cortex. All significant metabolic changes were confined to the side of the substantia nigra lesion and were essentially restricted to regions involved in the production of movement or maintenance of posture.

Optimal duration of experimental period in measurement of local cerebral glucose utilization with the deoxyglucose method

The time course and magnitude of the effects of product loss on the measurement of local cerebral glucose utilization (LCGU) by the 2-[14C]deoxyglucose (DG) method were studied by determination of LCGU in 38 rats with 25-120 min experimental periods after a [14C]DG pulse and in 45 rats with experimental periods of 2.5-120 min during which arterial plasma [14C]DG concentrations (C*P) were maintained constant. LCGU was calculated by the operational equation, which assumes no product loss, with the original set of rate constants and with a new set redetermined in the rats used in the present study; in each case the rate constants were those specific to the structure. Data on local tissue 14C concentrations and C*P were also plotted according to the multiple time/graphic evaluation technique ("Patlak Plot"). The results show that with both pulse and constant arterial inputs of [14C]DG the influence of the rate constants is critical early after onset of tracer administration but diminishes with time and becomes relatively minor by 30 min. After a [14C]DG pulse calculated LCGU remains constant between 25 and 45 min, indicating a negligible effect of product loss during that period; at 60 min it begins to fall and declines progressively with increasing time, indicating that product loss has become significant. When C*P is maintained constant, calculated LCGU does not change significantly over the full 120 min. The "Patlak Plots" reinforced the conclusions drawn from the time courses of calculated LCGU; evidence for loss of product was undetectable for at least 45 min after a pulse of [14C]DG and for at least 60 min after onset of a constant arterial input of [14C]DG.

Refinement of the kinetic model of the 2-[14C]deoxyglucose method to incorporate effects of intracellular compartmentation in brain

A translocase to transport hexose phosphate formed in the cytosol into the cisterns of the endoplasmic reticulum, where the phosphatase resides, is absent in brain (Fishman and Karnovsky, 1986). 2-Deoxyglucose-6-phosphate (DG-6-P) may therefore have limited access to glucose-6-phosphatase (G-6-Pase), and transport of the DG-6-P across the endoplasmic reticular membrane may be rate limiting to its dephosphorylation. To take this compartmentation into account, a five-rate constant (5K) model was developed to describe the kinetic behavior of 2-deoxyglucose (DG) and its phosphorylated product in brain. Loss of DG-6-P was modeled as a two-step process: (a) transfer of DG-6-P from the cytosol into the cisterns of the endoplasmic reticulum; (b) hydrolysis of DG-6-P by G-6-Pase and subsequent return of the free DG to the precursor pool. Local CMRglc (LCMRglc) was calculated in the rat on the basis of this model and compared with values calculated on the basis of the three-rate constant (3K) and the four-rate constant (4K) models of the DG method. The results show that under normal physiological conditions all three models yield values of LCMRglc that are essentially equivalent for experimental periods between 25 and 45 min. Therefore, the simplest model, the 3K model, is sufficient. For experimental periods from 60 to 120 min, the 4K and 5K models do not correct completely for loss of product, but the 5K model does yield estimates of LCMRglc that are closer to the values at 45 min than those obtained with the 3K and 4K models.

Local cerebral glucose utilization following unilateral and bilateral lesions of the nucleus basalis magnocellularis in the rat

To investigate to what extent the loss of cholinergic projections to the neocortex results in functional impairment in the target areas, local rates of cerebral glucose utilization were measured following excitotoxin lesions of the nucleus basalis magnocellularis (NBM) in the rat. Both unilateral and bilateral lesions of NBM resulted in reversible depression of cerebral metabolism. The effects of unilateral lesions were limited to the cortical areas which receive most of the cholinergic projections from NBM. The metabolic defect produced by bilateral lesions was spread to the whole brain. Within 4 months, however, normal metabolic values coexisted with marked changes of the presynaptic cholinergic markers and impairment of conditioned behavior.

Administration of MPTP acutely increases glucose utilization in the substantia nigra of primates

The quantitative 2-[14C]deoxyglucose autoradiographic method was used to map the regional distribution of the acute effects of administration of the neurotoxin, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), on local cerebral glucose utilization in rhesus monkeys. Metabolic activity was increased (+80%) in the substantia nigra pars compacta, which has been shown to be the main target site of MPTP toxicity. Metabolic activity was also increased in the nucleus paranigralis, nucleus parabrachialis pigmentosus, and ventral lamella of the inferior olive. In contrast, substantial decreases in glucose utilization were found diffusely distributed throughout many of the other structures examined, most prominently in portions of the cerebral cortex, thalamus, and cerebellum.

Local cerebral metabolic effects of L-dopa therapy in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced parkinsonism in monkeys

The quantitative 2-deoxy[14C]glucose autoradiographic method was used to map the distribution of alterations in local cerebral glucose utilization that accompanies clinically effective chronic L-dopa therapy of rhesus monkeys made parkinsonian by the administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). This pattern of changes was compared to the effects of a similar treatment regimen in normal monkeys. L-Dopa (100 mg with 10 mg carbidopa) was administered orally to normal and parkinsonian monkeys 3 times daily for 60-120 days prior to measurement of local cerebral glucose utilization. In parkinsonian monkeys treated with L-dopa, signs and symptoms of parkinsonism were controlled or suppressed, and widespread increases in glucose utilization were seen throughout the brain. Cerebral metabolic activity was increased both in areas rich in dopaminergic receptors, such as the caudate and putamen, and in nondopaminergic areas involved in motor functions. In many structures the rates of glucose utilization in L-dopa-treated parkinsonian monkeys were increased to levels that far exceeded rates measured in normal monkeys. In sharp contrast, similar treatment with L-dopa in normal monkeys had little if any effect on local cerebral glucose utilization. L-Dopa, then, appears to have an action in animals with selective lesions of the substantia nigra pars compacta produced by MPTP that is distinctly different from its effects in the normal monkey.

Changes in local cerebral glucose utilization associated with Parkinson's syndrome induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in the primate

The quantitative 2-[14C]deoxyglucose autoradiographic method was used to map the pattern of alterations in local cerebral glucose utilization associated with the Parkinsonian syndrome induced by the administration of the neurotoxin, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), to rhesus monkeys. Monkeys treated with the neurotoxin exhibited both behavioral symptoms (e.g. akinesia, rigidity, flexed posture, and eyelid closure) and neuropathological changes (degeneration of the cells of the substantia nigra pars compacta) that closely paralleled those in human Parkinson's disease. Glucose utilization was significantly reduced in the pars compacta of the substantia nigra and in the subthalamus, and increased in the external segment of the globus pallidus. Outside the basal ganglia reductions in glucose utilization were limited to the mediodorsal nucleus of the thalamus, frontal eye fields, and ventral tegmental area. The results of these studies indicate that the profound functional and behavioral deficits in MPTP-induced Parkinson's syndrome are the consequences of highly selective functional changes in a few cerebral structures, mainly within the basal ganglia.