Role of indigenous microbial communities in the mobilization of potentially toxic elements and rare-earth elements from alkaline mine waste.

This study aims to evaluate the role of indigenous microorganisms in the mobilization of potentially toxic elements (PTE) and rare-earth elements (REE), the influence of the bioavailability of carbon sources that might boost microbial leaching, and the generation of neutral/alkaline mine drainage from alkaline tailings. These tailings, with significant concentrations of total organic carbon (TOC), were mainly colonized by bacteria belonging to the genera Sphingomonas, Novosphingobium and Solirubrobacter, and fungi of the genera Alternaria, Sarocladium and Aspergillus. Functionality analysis suggests the capability of these microorganisms to leach PTE and REE. Bio-/leaching tests confirmed the generation of neutral mine drainage, the influence of organic substrate, and the leaching of higher concentrations of PTE and REE due to the production of organic acids and siderophores by indigenous microorganisms. In addition, this study offers some insights into a sustainable alternative for reprocessing PMC alkaline tailings to recover REE.

Bacterial communities shift and influence in an acid mine drainage treatment using barium carbonate disperse alkaline substrate system.

Chemical passive treatment systems used to remediate acid mine drainage has been evaluated based mainly on the reactivity of the chemical alkaline reagents, overlooking the activity of the microorganisms that proliferate in these artificial ecosystems. In this study, the bacterial communities of a unique passive treatment system known as BDAS (Barium carbonate Dispersed Alkaline Substrate) were investigated using 16S rRNA gene metagenomic sequencing combined with hydrochemical characterization of the AMD and phenotypic characterization of biogenic precipitates. According to the hydrochemical characterization, the water quality improved as the water progressed through the system, with a drastic increase in the pH (up to alkaline conditions) and total organic carbon, as well as the removal of main contaminants such as Ca2+, SO42-, Fe3+, Al3+, and Mn2+. These environmental changes resulted in an increase in bacterial diversity (richness) after the inlet and in the shift of the bacterial communities from chemoautotrophs (e.g., Ferrovum and Acidiphilum) to chemoheterotrophs (e.g., Brevundimonas and Geobacter). Some of these taxa harbour potential to immobilize metals, aiding in the treatment of the water. One of the mechanisms involved in the immobilization of metals is microbially induced calcium carbonate precipitation, which seems to occur spontaneously in BDAS. The production of biofilm was also observed in most parts of the system, except in the inlet, helping with the removal of metals. However, in the long run, the build-up of biofilm and precipitation of metals could clog (i.e., biofouling) the pores of the matrix, reducing the treatment efficiency. Potential human pathogens (e.g. Legionella) were also detected in BDAS indicating the need for a treatment step at the end of the system to remove pathogenic microorganisms. These findings present a new perspective of the bacterial communities and their effects (both positively and negatively) in a chemical passive treatment system.

Clinical Approach to Diagnosis of Pre-Dementia Alzheimer's Disease (CAD-PAD).

OBJECTIVE: Our aim was to evaluate clinical and neuropsychological features to identify pre-dementia Alzheimer's disease (PAD) among mild cognitive impairment (MCI) patients. METHODS: A longitudinal prospective study of 89 consecutive patients affected with MCI was conducted. Clinical evaluation consisted of a clinical interview protocol, neuropsychological evaluation, standard laboratory tests, and CT scan. A 6-month clinical check-up was made to determine whether patients remained in MCI, improved or progressed to AD or another dementia. RESULTS: At 3-year follow-up, 47% patients developed AD dementia. Seventeen variables were significant and were evaluated by logistic regression analysis to identify the remaining optimal diagnostic criteria: age, gender, repeating comments, difficulties in understanding explanations, time of symptom evolution, history of depression, and word fluency (with animals) were identified with a sensitivity of 100% and a specificity of 93%. A computer application was developed with all these variables which we have named Clinical Approach to Diagnosis of PAD (CAD-PAD). CONCLUSIONS: These results suggest that CAD-PAD can help in the clinical diagnosis of PAD.

[Proposal of criteria for clinical diagnosis of mild cognitive impairment, dementia and Alzheimer's disease]. / Propuesta de criterios para el diagnóstico clínico del deterioro cognitivo ligero, la demencia y la enfermedad de Alzheimer.

The most widely accepted criteria for Alzheimer's disease (AD) diagnosis (NINCDS-ADRDA and DSM-IV) do not allow to differentiate accurately between AD and other degenerative dementias which have recently formulated criteria for its clinical diagnosis. Therefore, it is necessary to bring AD diagnostic criteria up to date in order to optimise their specificity, by assessing its most specific clinical manifestations, its most representative markers and those features typical of other diseases which are usually taken into account for a differential diagnosis. According to the latest reports on the subject, the disturbances suffered by memory, behaviour and the rest of cognitive and executive functions must be equally considered when establishing the syndromic diagnosis of dementia; this will always require the coexistence of an evident functional impairment. Due to this, the concepts of "dementia" and "mild cognitive impairment" should be clearly distinguished. For the time being, AD can only be diagnosed when dementia has been proved and this shows a series of cognitive, behavioural and neurological features which are representative of it. Nevertheless, some diagnostic markers appear to be precocious and specific enough to try to identify those patients who suffer from mild cognitive impairment due to an incipient stage of AD. We are suggesting some criteria for the clinical diagnosis of dementia, mild cognitive impairment and AD that seem to be more detail

Propuesta de criterios para el diagnóstico clínico del deterioro cognitivo ligero, la demencia y la enfermedad de alzheimer / Proposal of criteria for clinical diagnosis of mild cognitive impairment, dementia and Alzheimer's disease

Los criterios diagnósticos de la enfermedad de Alzheimer (EA) más reconocidos (NINCDS-ADRDA y DSM-IV) no permiten diferenciar adecuadamente la EA de otras demencias degenerativas para las que, sin embargo, se han formulado recientemente criterios de diagnóstico clínico. Es, pues, necesario actualizar los criterios diagnósticos de la EA para optimizar su especificidad, valorando sus manifestaciones clínicas más características, sus marcadores más reconocidos y los rasgos propios de otras demencias que suelen considerarse en el diagnóstico diferencial.Según los conocimientos actuales, deben equipararse las alteraciones de la memoria, la conducta y las restantes funciones cognitivas y ejecutivas al establecer el diagnóstico sindrómico de demencia, que además requiere la coexistencia de un deterioro funcional relevante. Esto obliga a diferenciar con precisión los conceptos de "demencia" y "deterioro cognitivo leve". Por el momento, sólo puede diagnosticarse la EA cuando se ha establecido la existencia de demencia y ésta tiene unos rasgos cognitivos, conductuales y neurológicos característicos. Sin embargo, algunos marcadores diagnósticos parecen ser suficientemente precoces y específicos como para tratar de identificar los pacientes con deterioro cognitivo leve que sufren una fase incipiente de EA. Se proponen unos criterios de diagnóstico clínico de demencia, deterioro cognitivo leve y EA más detallados y presumiblemente más específicos que los actuales.Los criterios diagnósticos de la enfermedad de Alzheimer (EA) más reconocidos (NINCDS-ADRDA y DSM-IV) no permiten diferenciar adecuadamente la EA de otras demencias degenerativas para las que, sin embargo, se han formulado recientemente criterios de diagnóstico clínico. Es, pues, necesario actualizar los criterios diagnósticos de la EA para optimizar su especificidad, valorando sus manifestaciones clínicas más características, sus marcadores más reconocidos y los rasgos propios de otras demencias que suelen considerarse en el diagnóstico diferencial.Según los conocimientos actuales, deben equipararse las alteraciones de la memoria, la conducta y las restantes funciones cognitivas y ejecutivas al establecer el diagnóstico sindrómico de demencia, que además requiere la coexistencia de un deterioro funcional relevante. Esto obliga a diferenciar con precisión los conceptos de "demencia" y "deterioro cognitivo leve". Por el momento, sólo puede diagnosticarse la EA cuando se ha establecido la existencia de demencia y ésta tiene unos rasgos cognitivos, conductuales y neurológicos característicos. Sin embargo, algunos marcadores diagnósticos parecen ser suficientemente precoces y específicos como para tratar de identificar los pacientes con deterioro cognitivo leve que sufren una fase incipiente de EA. Se proponen unos criterios de diagnóstico clínico de demencia, deterioro cognitivo leve y EA más detallados y presumiblemente más específicos que los actuales. (AU)

[Multicenter register of index cases of dementia. A study by the Spanish Neurological Society's dementia group]. / Registro multicéntrico de casos incidentes de demencia. Un estudio del grupo de demencias de la Sociedad Española de Neurología.

We report the objectives and case registration methods used by neurologists belonging to the Spanish Neurological Society's dementia group (GERMICIDE). Forerunners of the present project are also described. The group's principal aim, which is to determine the distribution of dementia in the "neurological" environment is pursued by enrolling consecutive index cases (new presentations) arriving at 18 Spanish neurological units over a period of 2 years. A standard protocol was used to study the patients and final diagnoses were agreed upon in keeping with international criteria for dementia and the main neurological diseases (DSM-III-R, CDR and others). A second objective is to study risk factors for the main etiological groups of dementia (Alzheimer's disease and vascular dementia) and to follow each patient in the cohort until death in order to assess the course of disease and its biological markers. The series will be large, as there are already over 800 cases listed in the coordinating centre even though the period of enrollment has not ended.

[Study of neurological and cognitive changes in patients in stage III and initial phases of stage IV of infection by human immunodeficiency virus type 1]. / Estudio de las alteraciones neurológicas y cognitivas de pacientes en estadio III y fases iniciales de estadio IV de la infección por el virus de la inmunodeficiencia humana tipo 1.

BACKGROUND: To evaluate the prevalence of neurological and cognitive disorders in patients with the human immunodeficiency virus type 1 (HIV-1). METHODS: A transversal prospective study was carried out in 56 patients with HIV-1 and in 18 seronegative subjects by a protocolized neurological and cognitive examination. RESULTS: Twenty-seven patients were intravenous drug users (IVDU) and 29 were male homosexuals. Nineteen were in stage III of HIV-1 infection and 37 were in the initial phases of stage IV. No significant differences were found in the cognitive performance of patients in stage III when the control group was compared with seropositive patients. Significant differences were observed in stage IV in the Rey figure complex tests the B trace test and the number key. Three stage IV patients presented dementia criteria. No significant differences were seen in test performance upon comparing the ex-iVDU seropositive subgroup with the male homosexuals nor in the stage III or stage IV groups. CONCLUSIONS: Cognitive performance of stage III patients did not significantly differ from that of the seronegative control group; a global diminution in cognitive performance was observed in the stage IV group and there were no differences in the cognitive state between the two risk groups analyzed.

Subacute cerebellar syndrome as the first manifestation of AIDS dementia complex.

A patient presented with a subacute cerebellar syndrome in absence of cognitive impairment or other symptoms. He became demented several months after the onset of the disease. Necropsy demonstrated the typical features of the AIDS dementia complex and severe loss of Purkinje cells of the cerebellum. Patients with subacute cerebellar dysfunction should be evaluated for the presence of human immunodeficiency virus infection.

Cerebrospinal fluid neuropeptide Y in Alzheimer's disease.

The cerebrospinal fluid neuropeptide Y level was measured by radioimmunoassay in 20 patients with probable Alzheimer's disease and in 19 controls. The mean level was lower in patients (69.5 +/- 36.7 pg/ml) than in controls (103 +/- 21.8 pg/ml; p less than 0.001). Patients with a disease duration of greater than 2 years had cerebrospinal fluid neuropeptide Y levels lower than those with shorter disease duration (p less than 0.02). These results suggest that neuropeptide Y containing cells may be involved in Alzheimer's disease. No correlation was found between neuropeptide Y levels and degree of cognitive impairment or age at disease onset.

[Lumbosacral spinal cord infarction. Data from magnetic resonance imaging]. / Infarctus de la moelle lombosacrée. Données de l'imagerie par résonance magnétique.

A 77-year old woman and a 61-year old man with lumbosacral spinal cord ischaemic lesions and paraplegia presented with dissociated or partial forms of the lumbar enlargement artery (Adamkiewicz's artery) syndrom. Magnetic resonance imaging (MRI) was performed in both patient with an 0.15 Tesla resistive magnet. A hypersignal on T2-weighted images was present in both cases, which corresponded to the infarction affecting the lumbosacral part of the cord. MRI provided accurate delineation of the lesions and clinicoradiological correlations in both patients. The hypersignal occupied the lumbar cord in case 1 and the conus medullaris in case 2. The clinical signs and location of the lesions seemed to be determined by the different patterns of lumbosacral arterial supply. Since such images could be confused with tumoral images, surgical exploration was carried out in both patients; it failed to demonstrate any tumour or cyst and only showed a pale cord. Surgical cord biopsy in case 2 demonstrated ischaemic tissue. We conclude that ischaemia of the spinal cord can be demonstrated by MRI, but owing to the low specificity of this imaging method aedema cannot be distinguished from necrosis, gliosis or demyelination.

[AIDS dementia complex as the 1st manifestation of the acquired immunodeficiency syndrome]. / Complejo demencia del SIDA como primera manifestación del síndrome de immunodeficiencia adquirida.

In a prospective follow-up period from September 1987 to August 1988, the AIDS dementia complex (ADC) was the presenting clinical feature in six of 102 patients in whom AIDS was diagnosed in the Hospital Clínic i Provincial from Barcelona. The clinical picture was characterized by subcortical type deterioration and motor disturbances. Cerebrospinal fluid investigation and imaging techniques excluded other types of neurological involvement, and the diagnosis was confirmed at autopsy in two patients. The present study suggested that: 1) the ADC may be the presenting feature of AIDS in patients with unknown seropositive status; 2) in our area, ADC represents one of the most common causes of dementia in young patients, and 3) although a specific marker permitting a definitive clinical diagnosis is not available, at the time of diagnosis all patients had a severe degree of cellular immunosuppression induced by type 1 human immunodeficiency virus.

[AIDS dementia complex]. / Complejo demencia del SIDA.

The AIDS dementia complex (ADC) is the SNC complaint that appears most frequently in AIDS patients. ADC is characterized by a subacute onset of dementia accompanied by motor disturbance and changes in behaviour and is considered to be directly caused by HIV-1. Very frequent in advanced stages of AIDS, it can also be the way in which the illness appears. In 90% of the necropsies of these patients a diffuse demyelination of the white substance is observed with multinucleate cells appearing in 40% of the cases. Up to now, the factors triggering this disease are not well understood, nevertheless, the immunosuppression present in these individuals could act as a factor favouring the appearance of ADC. A specific marker does not exist and, therefore, the complementary studies can only help to eliminate other causes of neurological complaints. Successful tests of treatment with zidovudine have been made, although it would be necessary to carry out studies with a larger number of patients to be able to evaluate its long-term efficacity.

5-Hydroxytryptophan versus methysergide in the prophylaxis of migraine. Randomized clinical trial.

One hundred and twenty-four migraineurs were treated randomly with 5-hydroxytryptophan (5-HTP) or with methysergide (M). The two groups were homogeneous without significant statistical differences with respect to age, sex, pill use, type of migraine and frequency of attacks before entry. A significant improvement was observed in 75% of the patients treated with M and in 71% of the cases treated with 5-HTP. The most beneficial effect of 5-HTP appears to be felt with regard to the intensity and duration rather than the frequency of the attacks. Side effects were more frequent in the M group than in the 5-HTP group. These results suggest that 5-HTP could be a treatment of choice in the prophylaxis of migraine.