Sleep Problems Are Related to a Worse Quality of Life and a Greater Non-Motor Symptoms Burden in Parkinson's Disease.

INTRODUCTION: The aim of the present study was to examine the frequency of self-reported sleep problems and their associated factors in a large cohort of PD patients. METHODS: PD patients and controls, recruited from 35 centers of Spain from the COPPADIS cohort were included in this cross-sectional study. Sleep problems were assessed by the Spanish version of the Parkinson's disease Sleep Scale version 1 (PDSS-1). An overall score below 82 or a score below 5 on at least 1 item was defined as sleep problems. RESULTS: The frequency of sleep problems was nearly double in PD patients compared to controls: 65.8% (448/681) vs 33.5% (65/206) (p < 0.0001). Mean total PDSS score was lower in PD patients than controls: 114.9 ± 28.8 vs 132.8 ± 16.3 (p < 0.0001). Quality of life (QoL) was worse in PD patients with sleep problems compared to those without: PDQ-39SI, 19.3 ± 14 vs 13 ± 11.6 (p < 0.0001); EUROHIS-QoL8, 3.7 ± 0.5 vs 3.9 ± 0.5 (p < 0.0001). Non-motor symptoms burden (NMSS; OR = 1.029; 95%CI 1.015-1.043; p < 0.0001) and impulse control behaviors (QUIP-RS; OR = 1.054; 95%CI 1.009-1.101; p = 0.018) were associated with sleep problems after adjustment for age, gender, disease duration, daily equivalent levodopa dose, H&Y, UPDRS-III, UPDRS-IV, PD-CRS, BDI-II, NPI, VAS-Pain, VAFS, FOGQ, and total number of non-antiparkinsonian treatments. CONCLUSION: Sleep problems were frequent in PD patients and were related to both a worse QoL and a greater non-motor symptoms burden in PD. These findings call for increased awareness of sleep problems in PD patients.

Non-motor symptom burden is strongly correlated to motor complications in patients with Parkinson's disease.

BACKGROUND AND PURPOSE: The objective of this study was to analyze the relationship between motor complications and non-motor symptom (NMS) burden in a population of patients with Parkinson's disease (PD) and also in a subgroup of patients with early PD. METHODS: Patients with PD from the COPPADIS cohort were included in this cross-sectional study. NMS burden was defined according to the Non-Motor Symptoms Scale (NMSS) total score. Unified Parkinson's Disease Rating Scale (UPDRS) part IV was used to establish motor complication types and their severity. Patients with ≤5 years of symptoms from onset were included as patients with early PD. RESULTS: Of 690 patients with PD (62.6 ± 8.9 years old, 60.1% males), 33.9% and 18.1% presented motor fluctuations and dyskinesia, respectively. The NMS total score was higher in patients with motor fluctuations (59.2 ± 43.1 vs. 38.3 ± 33.1; P < 0.0001) and dyskinesia (63.5 ± 40.7 vs. 41.4 ± 36.3; P < 0.0001). In a multiple linear regression model and after adjustment for age, sex, disease duration, Hoehn & Yahr stage, UPDRS-III score and levodopa equivalent daily dose, UPDRS-IV score was significantly related to a higher NMSS total score (ß = 0.27; 95% confidence intervals, 2.81-5.61; P < 0.0001), as it was in a logistic regression model on dichotomous NMSS total score (≤40, mild or moderate vs. >40, severe or very severe) (odds ratio, 1.31; 95% confidence intervals, 1.17-1.47; P < 0.0001). In the subgroup of patients with early PD (n = 396; mean disease duration 2.7 ± 1.5 years), motor fluctuations were frequent (18.1%) and similar results were obtained. CONCLUSIONS: Motor complications were frequent and were associated with a greater NMS burden in patients with PD even during the first 5 years of disease duration.

COPPADIS-2015 (COhort of Patients with PArkinson's DIsease in Spain, 2015): an ongoing global Parkinson's disease project about disease progression with more than 1000 subjects included. Results from the baseline evaluation.

BACKGROUND AND PURPOSE: In Parkinson's disease (PD), the course of the disorder is highly variable between patients. Well-designed, prospective studies for identifying PD progression biomarkers are necessary. Our aim was to show the results of baseline evaluations of an ongoing global PD project, COPPADIS-2015 (Cohort of Patients with PArkinson's DIsease in Spain, 2015). METHODS: This was an observational, descriptive, nationwide study (Spain). The recruitment period ended in October 2017. Baseline evaluation included more than 15 validated scales and complementary studies in a subgroup of participants. RESULTS: In total, 1174 subjects from 35 centres were considered valid for baseline analysis: 694 patients (62.6 ± 8.9 years old, 60.3% males), 273 caregivers (58.5 ± 11.9 years old, 31.8% males) and 207 controls (61 ± 8.3 years old, 49.5% males). The mean disease duration was 5.5 ± 4.4 years. Hoehn and Yahr stage was 1 or 2 in 90.7% of the patients whilst 33.9% and 18.1% of them presented motor fluctuations and dyskinesias, respectively. The mean Non-Motor Symptoms Scale total score was 45.4 ± 38.1, and 30.4% of the patients presented cognitive impairment, 16.1% major depression, 12.7% impulse control disorder, 7.2% compulsive behaviour, 57.2% pain and 13.2% falls. Compared to the control group, PD patients presented a significantly higher burden of non-motor symptoms and a worse quality of life. More than 300 subjects conducted complementary studies (serum biomarkers, genetic and neuroimaging). CONCLUSIONS: Parkinson's disease is a complex disorder and different non-motor symptoms are frequently present and are more prevalent than in controls. In real clinical practice it is important to ask for them.

Cerebrospinal fluid immunological biomarkers associated with axonal damage in multiple sclerosis.

BACKGROUND AND PURPOSE: Cerebrospinal fluid (CSF) neurofilament light protein (NFL) is a promising biomarker of axonal injury and neurodegeneration. Here CSF lymphocyte subpopulations and antibodies, potential players of neurodegeneration, are examined in relation to CSF NFL shedding in MS. METHODS: Cerebrospinal fluid NFL from 127 consecutive untreated MS patients was analysed. Samples from 37 age-matched patients with other central nervous system non-inflammatory neurological diseases (NIND) were also assessed. CD4+, CD8+, CD56+ and CD19+ cell subsets were studied by flow cytometry. Oligoclonal IgG and IgM bands (OCMB) against lipids were studied by isoelectric focusing and immunoblotting. These data were analysed in relation to clinical and magnetic resonance imaging features. RESULTS: A CSF NFL cut-off value of 900 ng/l (mean + 3 SD of NIND values) was calculated. MS patients with increased NFL values showed significantly higher Multiple Sclerosis Severity Score and magnetic resonance imaging lesion number. The presence of OCMB (P < 0.0001) and elevated T and B lymphocyte counts was associated with increased levels of CSF NFL. CONCLUSIONS: High CSF NFL levels are associated with elevated CSF lymphocyte cell counts and intrathecal synthesis of IgM against lipids. These findings support a role for OCMB in the axonal damage of MS offering a rationale for the association of these antibodies with disability and brain atrophy progression in MS.

Exome sequencing is a useful diagnostic tool for complicated forms of hereditary spastic paraplegia.

Hereditary spastic paraplegias constitute a heterogeneous group of neurodegenerative diseases encompassing pure and complicated forms, for which at least 52 loci and 31 causative genes have been identified. Although mutations in the SPAST gene explain approximately 40% of the pure autosomal dominant forms, molecular diagnosis can be challenging for the sporadic and recessive forms, which are often complicated and clinically overlap with a broad number of movement disorders. The validity of exome sequencing as a routine diagnostic approach in the movement disorder clinic needs to be assessed. The main goal of this study was to explore the usefulness of an exome analysis for the diagnosis of a complicated form of spastic paraplegia. Whole-exome sequencing was performed in two Spanish siblings with a neurodegenerative syndrome including upper and lower motor neuron, ocular and cerebellar signs. Exome sequencing revealed that both patients carry a novel homozygous nonsense mutation in exon 15 of the SPG11 gene (c.2678G>A; p.W893X), which was not found in 584 Spanish control chromosomes. After many years of follow-up and multiple time-consuming genetic testing, we were able to diagnose these patients by making use of whole-exome sequencing, showing that this is a cost-efficient diagnostic tool for the movement disorder specialist.

Off-label intravenous thrombolysis in acute stroke.

BACKGROUND AND PURPOSE: Therapy for stroke with intravenous tissue plasminogen activator (IV-tPA) is hampered by tight licensing restrictions; some of them have been discussed in recent literature. We assessed the safety and effectiveness of off-label IV-tPA in the clinical settings. METHODS: Retrospective analysis of all the patients treated with IV-tPA at our Stroke Unit. Patients were divided into two groups by licence criteria [on-label group (OnLG), off-label group (OffLG)]. Primary outcome measures were symptomatic intracranial haemorrhages (sICH), major systemic haemorrhages, modified Rankin scale (mRS) and mortality rate at 3months. RESULTS: Five hundred and five patients were registered, 269 (53.2%) were assigned to OnLG and 236 (46.9%) to OffLG. Inclusion criteria for the OffLG were aged >80 years (129 patients), time from onset of symptoms to treatment over 3h (111), prior oral anticoagulant treatment with International Normalised Ratio≤1.7 (41), combination of previous stroke and diabetes mellitus (14), surgery or severe trauma within 3months of stroke (13), National Institutes of Health Stroke Scale score over 25 (11), intracranial tumours (5), systemic diseases with risk of bleeding (7) and seizure at the onset of stroke (2). No significant differences were identified between both groups regarding the proportion of sICH (OnLG 2.2% vs. OffLG 1.6%, P=0.78) or the 3-month mortality rate (11.1% vs. 19%: odds ratio (OR), 1.49; 95% CI, 0.86-2.55; P=0.14). Multivariate analysis showed no significant differences in functional independence at 3months between both groups (mRS <3 64.3% vs. 50.4%: OR mRS >2 1.7; 95% CI, 0.96-2.5; P=0.07). CONCLUSION: Intravenous thrombolysis may be safe and efficacious beyond its current label restrictions.

Depression is Associated with Impulse-compulsive Behaviors in Parkinson's disease.

BACKGROUND: Depression and impulse control disorders (ICDs) are both common in Parkinson's disease (PD) patients and their coexistence is frequent. Our aim was to determine the relationship between depression and impulsive-compulsive behaviors (ICBs) in a large cohort of PD patients. METHODS: PD patients recruited from 35 centers of Spain from the COPPADIS cohort from January 2016 to November 2017 were included in the study. The QUIP-RS (Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale) was used for screening ICDs (cutoff points: gambling ≥6, buying ≥8, sex≥8, eating≥7) and compulsive behaviors (CBs) (cutoff points: hobbyism-punding ≥7). Mood was assessed with the BDI-II (Beck Depression Inventory - II) and major, minor, and subthreshold depression were defined. RESULTS: Depression was more frequent in PD patients with ICBs than in those without: 66.3% (69/104) vs 47.5% (242/509); p<0.0001. Major depression was more frequent in this group as well: 22.1% [23/104] vs 14.5% [74/509]; p=0.041. Considering types of ICBs individually, depression was more frequent in patients with pathological gambling (88.9% [8/9] vs 50.2% [303/603]; p=0.021), compulsive eating behavior (65.9% [27/41] vs 49.7% [284/572]; p=0.032), and hobbyism-punding (69% [29/42] vs 49.4% [282/571]; p=0.010) than in those without, respectively. The presence of ICBs was also associated with depression (OR=1.831; 95%CI 1.048-3.201; p=0.034) after adjusting for age, sex, civil status, disease duration, equivalent daily levodopa dose, antidepressant treatment, Hoehn&Yahr stage, non-motor symptoms burden, autonomy for activities of daily living, and global perception of QoL. LIMITATIONS: Cross-sectional design. CONCLUSIONS: Depression is associated with ICBs in PD. Specifically, with pathological gambling, compulsive eating behavior, and hobbyism-punding.

[Opicapone for the treatment of Parkinson's disease: real-life data in Spain]. / Opicapona para el tratamiento de la enfermedad de Parkinson: datos de vida real en España.

Opicapone is a catechol-O-methyl-transferase (iCOMT) inhibitor authorized in Europe in 2016 and indicated as adjunctive therapy to preparations of levodopa/ DOPA decarboxylase inhibitors in adult patients with Parkinson's disease and end-of-dose motor fluctuations who cannot be stabilised on those combinations. The efficacy of opicapone in these patients has been demonstrated in two pivotal randomized clinical trials, BIPARK I and BIPARK II, in which it has demonstrated its superiority versus placebo and non-inferiority versus entacapone. Although they constitute the gold standard for the evaluation of interventions, randomized clinical trials present limitations of external validity due to the use of strict eligibility criteria. Therefore, it is considered necessary to have a more comprehensive evaluation of the efficacy of the drug, complementing the information obtained from randomized clinical trials with that of "real world or real clinical practice" studies. The objective of this review has been to collect and put into perspective the information available on opicapone coming from real clinical practice studies in Spain. The data from Spain with opicapone in 18 series with more than 1,000 patients in total, confirm the safety and efficacy previously reported with this iCOMT. Furthermore, they show that opicapone is especially useful in patients with a less advanced stage of the disease and mild motor fluctuations, which would suggest that the earlier its introduction in the therapeutic scheme for the management of motor fluctuations, the better is the benefit-risk ratio for the drug.

TITLE: Opicapona para el tratamiento de la enfermedad de Parkinson: datos de vida real en España.Resumen. La opicapona es un inhibidor de la catecol-O-metiltransferasa (iCOMT) autorizado en Europa en 2016 como terapia adyuvante a las preparaciones de levodopa/inhibidores de la dopa descarboxilasa en pacientes adultos con enfermedad de Parkinson y fluctuaciones motoras de final de dosis que no puedan ser estabilizados con esas combinaciones. La eficacia de la opicapona en estos pacientes ha sido demostrada en dos ensayos clínicos pivotales, BIPARK I y BIPARK II, en los que se ha demostrado la superioridad frente al placebo y la no inferioridad frente a la entacapona. A pesar de que constituyen el estándar para la evaluación de intervenciones, los ensayos clínicos aleatorizados presentan limitaciones de validez externa debidas a la utilización de criterios estrictos de elegibilidad. Por tanto, se considera necesario disponer de una evaluación más amplia de la eficacia general del fármaco, complementando la información de los ensayos clínicos aleatorizados con estudios de 'vida real o práctica clínica real'. El objetivo de esta revisión ha sido recopilar y poner en perspectiva la información disponible sobre los resultados de la opicapona en estudios de práctica clínica real en España. Los datos acumulados en España con opicapona en 18 series con más de 1.000 pacientes confirman la seguridad y la eficacia de este iCOMT comunicadas previamente. Además, muestran que la opicapona es especialmente útil en pacientes en un estadio de la enfermedad menos avanzado y fluctuaciones motores leves, lo que sugeriría una mejor relación beneficio-riesgo cuanto más temprana sea su introducción en el esquema terapéutico para el tratamiento de las fluctuaciones motoras.

Staging Parkinson's Disease Combining Motor and Nonmotor Symptoms Correlates with Disability and Quality of Life.

INTRODUCTION: In a degenerative disorder such as Parkinson's disease (PD), it is important to establish clinical stages that allow to know the course of the disease. Our aim was to analyze whether a scale combining Hoehn and Yahr's motor stage (H&Y) and the nonmotor symptoms burden (NMSB) (assessed by the nonmotor symptoms scale (NMSS)) provides information about the disability and the patient's quality of life (QoL) with regard to a defined clinical stage. MATERIALS AND METHODS: Cross-sectional study in which 603 PD patients from the COPPADIS cohort were classified according to H&Y (1, stage I; 2, stage II; 3, stage III; 4, stage IV/V) and NMSB (A: NMSS = 0-20; B: NMSS = 21-40; C: NMSS = 41-70; D: NMSS ≥ 71) in 16 stages (HY.NMSB, from 1A to 4D). QoL was assessed with the PDQ-39SI, PQ-10, and EUROHIS-QOL8 and disability with the Schwab&England ADL (Activities of Daily Living) scale. RESULTS: A worse QoL and greater disability were observed at a higher stage of H&Y and NMSB (p < 0.0001). Combining both (HY.NMSB), patients in stages 1C and 1D and 2C and 2D had significantly worse QoL and/or less autonomy for ADL than those in stages 2A and 2B and 3A and 3B, respectively (p < 0.005; e.g., PDQ-39SI in 1D [n = 15] vs 2A [n = 101]: 28.6 ± 17.1 vs 7.9 ± 5.8; p < 0.0001). CONCLUSION: The HY.NMSB scale is simple and reflects the degree of patient involvement more accurately than the H&Y. Patients with a lower H&Y stage may be more affected if they have a greater NMS burden.

Quality of life and non-motor symptoms in Parkinson's disease patients with subthreshold depression.

BACKGROUND: The role of subthreshold depression (subD) in Parkinson's Disease (PD) is not clear. The present study aimed to compare the quality of life (QoL) in PD patients with subD vs patients with no depressive disorder (nonD). Factors related to subD were identified. MATERIAL AND METHODS: PD patients and controls recruited from the COPPADIS cohort were included. SubD was defined as Judd criteria. The 39-item Parkinson's disease Questionnaire (PDQ-39) and the EUROHIS-QOL 8-item index (EUROHIS-QOL8) were used to assess QoL. RESULTS: The frequency of depressive symptoms was higher in PD patients (n = 694) than in controls (n = 207) (p < 0.0001): major depression, 16.1% vs 7.8%; minor depression, 16.7% vs 7.3%; subD, 17.4% vs 5.8%. Both health-related QoL (PDQ-39; 18.1 ±â€¯12.8 vs 11.6 ±â€¯10; p < 0.0001) and global QoL (EUROHIS-QOL8; 3.7 ±â€¯0.5 vs 4 ±â€¯0.5; p < 0.0001) were significantly worse in subD (n = 120) than nonD (n = 348) PD patients. Non-motor Symptoms Scale (NMSS) total score was higher in subD patients (45.9 ±â€¯32 vs 29.1 ±â€¯25.8;p < 0.0001). Non-motor symptoms burden (NMSS;OR = 1.019;95%CI 1.011-1.028; p < 0.0001), neuropsychiatric symptoms (NPI; OR = 1.091; 95%CI 1.045-1.139; p < 0.0001), impulse control behaviors (QUIP-RS; OR = 1.035; 95%CI 1.007-1063; p = 0.013), quality of sleep (PDSS; OR = 0.991; 95%CI 0.983-0.999; p = 0.042), and fatigue (VAFS-physical; OR = 1.185; 95%CI 1.086-1.293; p < 0.0001; VAFS-mental; OR = 1.164; 95%CI 1.058-1.280; p = 0.0001) were related to subD after adjustment to age, disease duration, daily equivalent levodopa dose, motor status (UPDRS-III), and living alone. CONCLUSIONS: SubD is a frequent problem in patients with PD and is more prevalent in these patients than in controls. QoL is worse and non-motor symptoms burden is greater in subD PD patients.

[Myths and evidence on the use of botulinum toxin: neuropharmacology and dystonia]. / Mitos y evidencias en el empleo de la toxina botulinica: neurofarmacologia y distonias.

INTRODUCTION: Botulinum toxin type A (BTA) is a bacterial endotoxin, whose therapeutic use has had a dramatic impact on different neurological disorders, such as dystonia and spasticity. AIM: To analyze and summarize different questions about the use of BTA in our clinical practice. DEVELOPMENT: A group of experts in neurology developed a list of topics related with the use of BTA. Two groups were considered: neuropharmacology and dystonia. A literature search at PubMed, mainly for English language articles published up to June 2016 was performed. The manuscript was structured as a questionnaire that includes those questions that, according to the panel opinion, could generate more controversy or doubt. The initial draft was reviewed by the expert panel members to allow modifications, and after subsequent revisions for achieving the highest degree of consensus, the final text was then validated. Different questions about diverse aspects of neuropharmacology, such as mechanism of action, bioequivalence of the different preparations, immunogenicity, etc. were included. Regarding dystonia, the document included questions about methods of evaluation, cervical dystonia, blepharospasm, etc. CONCLUSION: This review does not pretend to be a guide, but rather a tool for continuous training of residents and specialists in neurology, about different specific areas of the management of BTA.

TITLE: Mitos y evidencias en el empleo de la toxina botulinica: neurofarmacologia y distonias.Introduccion. La toxina botulinica de tipo A (TBA) ha supuesto una verdadera revolucion terapeutica en neurologia, y en la actualidad es el tratamiento rutinario en las distonias focales y la espasticidad. Objetivo. Plantear, revisar y responder cuestiones controvertidas en relacion con la neurofarmacologia de la TBA y su uso en las distonias en la practica clinica habitual. Desarrollo. Un grupo de expertos en trastornos del movimiento reviso una lista de temas controvertidos relacionados con la farmacologia de la TBA y su uso en las distonias. Revisamos la bibliografia e incluimos articulos relevantes especialmente en ingles, pero tambien, si su importancia lo merece, en castellano y en frances, hasta junio de 2016. El documento se estructuro como un cuestionario que incluyo las preguntas que podrian generar mayor controversia o duda. El borrador inicial del documento fue revisado por los miembros del panel y se realizaron las modificaciones necesarias hasta alcanzar el mayor grado de consenso. Incluimos preguntas sobre diferentes aspectos de la neurofarmacologia, especialmente el mecanismo de accion, la bioequivalencia de los diferentes preparados y la inmunogenicidad. En relacion con el subapartado de las distonias, se incluyeron aspectos sobre la evaluacion y el tratamiento de las distonias focales. Conclusiones. Esta revision no pretende ser una guia, sino una herramienta practica destinada a neurologos y medicos internos residentes interesados en esta area, dentro de diferentes ambitos especificos del manejo de la TBA.

Reaction time and rhythm of movement in Huntington's disease.

Huntington disease (HD) is characterized by several hyperkinesias though motor slowness is also another cardinal in this disease. In addition, self-paced timing movements are also disturbed in HD, which may also affect several rhythmic voluntary movements such as gait. Motor slowness can be measured with clinical scales such as the Unified Huntington's Disease Rating Scale (UHDRS) and timed tests, but also with the reaction time (RT) paradigm. We evaluated RT as a measure of motor slowness in 30 patients with genetically confirmed Huntington's disease and 24 control subjects. We also evaluated self-paced timing precision (SPTP) by applying a simple software program devised by our group. Clinical assessment was performed according to the UHDRS, including motor section, total functional capacity (TFC) and cognitive section (verbal fluency test, symbol digit, and Stroop test) The mean values obtained for RT and SPTP were statistically different in HD as compared with those from controls (p<0.0005). We observed a statistically significant correlation between RT and TFC scores (rs=-0.57, p<0.005 Spearman's correlation) and also between SPTP values and TFC scores (rs=-0.40, p<0.05 Spearman's correlation). In addition, RT and SPTP significantly correlated with cognitive scores (including digit symbol, verbal fluency and Stroop tests). Simple tests such as RT and SPTP provide an objective evaluation of motor impairment in HD yielding measures that correlate with clinical assessment and functional disability.

The lytic enzyme of the Pseudomonas phage phi 6. Purification and biochemical characterization.

The lytic enzyme of the lipid-containing bacteriophage phi 6, protein P5, has been purified to apparent homogeneity from disrupted viral particles. The enzyme is a monomer with a molecular mass of approx. 24 kDa. The optimal pH for P5 activity is 8.5 and the protein is readily inactivated at temperatures above 20 degrees C. Protein P5 is active against several Gram-negative bacteria, but no activity against Gram-positive species was detected. Analysis of cell wall digests indicates that P5 is not a glycosidase, but an endopeptidase splitting the peptide bridge formed by meso-diaminopimelic acid and D-alanine.

Assembly and disassembly of bacteriophage T4 polyheads.

The assembly of the product of bacteriophage T4 gene 23 (gp23), the uncleaved form of the main shell protein, has been studied. Assembly and disassembly follow the predictions for entropy-driven processes; assembly is strongly favored by conditions of high salt concentrations and high temperatures, whereas low salt and low temperatures promote disassembly. In the absence of the scaffolding core proteins in vitro, only polyheads, the tubular variant of the prohead, are produced. Kinetic studies show that the rate of polyhead dissociation depends on the concentration of associated protein, not on the number and length of the particles. Comparable to crystal formation, assembly of gp23 occurs above a critical concentration, which is dependent on salt concentration, pH and temperature. These characteristics are common to most self-assembling systems. The oligomeric states of gp23 have been investigated by analytical ultracentrifugation, which indicated the existence, at very low salt concentration and low temperature, of an equilibrium between monomers and higher oligomers, culminating in the hexamer. At pH 9.0 polyheads are completely dissociated into their monomeric gp23 subunits. Our data suggest that the hexamer is a true intermediate of polyhead assembly.

Isolation and reassembly of bacteriophage T4 core proteins.

The products of genes 22, 67 and 68, and the internal proteins IPI, IPII and IPIII, as components of the scaffolding core of the bacteriophage T4 prohead, have been isolated and purified by hydroxylapatite column chromatography. Under conditions promoting reassembly in vitro, the proteins associated into elongated particles of practically constant width but variable length that we have called polycores. Preliminary optical diffraction experiments indicate that polycores may have an ordered structure, possibly helical, as has been suggested for the polyhead core. The coassembly of core proteins and the purified shell protein gp23 results in the formation of core-containing polyheads. Occasionally, prolate core-like particles have been observed but their reproducible formation has not been attained. Attempts to investigate the role of the minor prohead component gp20 in core assembly have been made through the cloning of the corresponding gene in an expression vector and subsequent purification of the protein.

Gene 20 product of bacteriophage T4. II. Its structural organization in prehead and bacteriophage.

The location of gene 20 product of bacteriophage T4 in phage and phage percursors has been determined by immunochemical analysis of polyacrylamide gels, immunoturbidimetry and immunoelectron microscopy. The protein is present at the membrane attachment site of the prehead, a head precursor, and is accessible to the antibodies in the solution. It is present at the tail attachment site of the capsid, partially buried in the structure. In complete phage particles it is totally buried in the structure. It is in contact with the major shell proteins, gp23 and gp23*, respectively, in preheads and capsids, as revealed by partial crosslinking experiments. It forms the upper collar of the neck in necked tails. The lower collar is constructed from other gene products. On the basis of these data a structural model of the neck region of the phage has been derived. This model is consistent with a number of events in phage assembly, such as the role of gp20 in head assembly and DNA packaging, prehead detachment from the bacterial membrane and head-tail attachment. The symmetry mismatch known to occur between head and tail has been localized at the gp20-gp23* contact area.

Bacteriophage PRD1 contains a labile receptor-binding structure at each vertex.

Bacteriophage PRD1 is a membrane-containing virus with an unexpected similarity to adenovirus. We mutagenized unassigned PRD1 genes to identify minor capsid proteins that could be structural or functional analogs to adenovirus proteins. We report here the identification of an amber mutant, sus525, in an essential PRD1 gene XXXI. The gene was cloned and the gene product was overexpressed and purified to near homogeneity. Analytical ultracentrifugation and gel filtration showed that P31 is a homopentamer of about 70 kDa. The protein was shown to be accessible on the virion surface and its absence in the sus525 particles led to the deficiency of two other viral coat proteins, protein P5 and the adsorption protein P2. Cryo-electron microscopy and image reconstruction of the sus525 particles indicate that these proteins are located on the capsid vertices, because in these particles the entire vertex structure was missing along with the peripentonal major capsid protein P3 trimers. Sus525 particles package DNA effectively but loose it upon purification. All of the PRD1 vertex structures are labile and potentially capable of mediating DNA delivery; this is in contrast to other dsDNA phages which employ a single vertex for packaging and delivery. We propose that this arises from a symmetry mismatch between protein P2 and the pentameric P31 in analogy to that between the adenovirus penton base and the receptor-binding spike.

Bacteriophage PRD1 terminal protein: expression of gene VIII in Escherichia coli and purification of the functional P8 product.

The gene VIII coding for the bacteriophage PRD1 terminal protein P8 has been cloned under the control of the lambda pL promoter. The recombinant plasmid thus obtained (pUSH20) was able to complement a mutation in the phage terminal-protein gene VIII. High expression of the cloned gene from this plasmid could be obtained by raising the growth temperature from 28 to 42 degrees C. This heat induction resulted in an increased synthesis of a protein of 30 kDa, the size expected for the P8 protein. When complemented with an extract of cells carrying the PRD1 DNA polymerase gene, the extract from the cells harboring the plasmid pUSH20 was able to form the P8-dGMP replication initiation complex. The PRD1 replication initiation reaction was optimized and used to detect the biological activity of the expressed terminal protein. Subsequently, P8 protein was purified to almost homogeneity and shown to be biologically functional after the various purification steps.

Overproduction, purification, and characterization of DNA-binding protein P19 of bacteriophage PRD1.

The early protein, P19, of bacteriophage PRD1 was purified after overexpression of the cloned gene, XIX, in Escherichia coli DH5 alpha cells. The purified protein binds as multimers to single-stranded DNA (ssDNA), and with a lower affinity to double-stranded DNA (dsDNA), without sequence-specificity. Two distinct P19-ssDNA complexes were discovered in gel- mobility-shift assays at different protein:DNA ratios. P19 was capable of fully protecting ssDNA against nuclease P1. Electron microscopy of protein P19-ssDNA complexes showed DNA molecules which were extensively coated with protein and whose contour length was clearly reduced by P19 binding. The results suggest that P19 binds to ssDNA with moderate cooperativity and are consistent with the DNA being wrapped around the P19 multimers.

[Biomarkers in Alzheimer's disease]. / Biomarcadores en la enfermedad de Alzheimer.

The new diagnostic criteria for Alzheimer's disease (AD) include brain imaging and cerebrospinal fluid (CSF) biomarkers, with the aim of increasing the certainty of whether a patient has an ongoing AD neuropathologic process or not. Three CSF biomarkers, Aß42, total tau, and phosphorylated tau, reflect the core pathological features of AD. It is already known that these pathological processes of AD starts decades before the first symptoms, so these biomarkers may provide means of early disease detection. At least three stages of AD could be identified: preclinical AD, mild cognitive impairment due to AD, and dementia due to AD. In this review, we aim to summarize the CSF biomarker data available for each of these stages. We also review the actual research on blood-based biomarkers. Recent studies on healthy elderly subjects and on carriers of dominantly inherited AD mutations have also found biomarker changes that allow separate groups in these preclinical stages. These studies may aid for segregate populations in clinical trials and objectively evaluate if there are changes over the pathological processes of AD. Limits to widespread use of CSF biomarkers, apart from the invasive nature of the process itself, is the higher coefficient of variation for the analyses between centres. It requires strict pre-analytical and analytical procedures that may make feasible multi-centre studies and global cut-off points for the different stages of AD.

TITLE: Biomarcadores en la enfermedad de Alzheimer.Los nuevos criterios diagnosticos para la enfermedad de Alzheimer (EA) incluyen la posibilidad de practicar tecnicas de neuroimagen o analisis del liquido cefalorraquideo con el objeto de aumentar la certeza de que un paciente presenta un proceso neuropatologico relacionado con la EA. Tres biomarcadores del liquido cefalorraquideo (Aß42, tau total y tau fosforilada) reflejan las caracteristicas patologicas centrales de la EA. Estos procesos neuropatologicos se inician decadas antes de que sean detectables sintomas, por lo que se esta determinando si estos biomarcadores pueden ser utiles en la deteccion precoz y prevencion de la demencia. Podemos definir tres estadios de la EA: estadio preclinico, deterioro cognitivo leve debido a EA y demencia por EA. En esta revision, se resumen las evidencias de biomarcadores en cada uno de estos estadios. Tambien se revisan los estudios que investigan biomarcadores para la EA en sangre. Los estudios en ancianos asintomaticos y en portadores de mutaciones autosomicas dominantes de EA han mostrado alteraciones en los biomarcadores que permiten la segregacion en estos estadios preclinicos. Estos estudios permitiran identificar las poblaciones diana de los ensayos clinicos futuros y evaluar de manera objetiva si se producen modificaciones sobre el proceso patologico de la EA. El desarrollo de los biomarcadores del liquido cefalorraquideo requiere unos procedimientos normalizados preanaliticos y analiticos estrictos que hagan fiables los estudios multicentricos y universalicen los puntos de corte de la tecnica en los distintos estadios de la EA.