Plackett-Burman design in the biosynthesis of silver nanoparticles with Mutisia acuminatta (Chinchircoma) and preliminary evaluation of its antibacterial activity.

Background: The aim of this study was to synthesize silver nanoparticles (AgNPs) using the methanolic fraction of Mutisia acuminatta leaves using Plackett-Burman design to optimize process parameters and to evaluate its antibacterial effect. Methods: For the separation of Mutisia acuminatta phytoconstituents, chromatographic techniques were used. For characterization and identification, UV - VIS spectrophotometry, FTIR spectrophotometry, Dynamic Light Scattering (DLS) and transmission electron microscopy (TEM) were used. The Plackett-Burman design used polynomial regression statistical analysis to determine the most influential variables. Results: UV-VIS spectroscopy reported an absorbance concerning surface plasmon resonance between 410-420 nm wavelength for the AgNPs. FTIR spectrophotometry reported characteristic peaks in the biosynthesized AgNPs, observing the disappearance of spectral peaks between 1000-1500 cm -1. By UHPLC-MS, caffeic acid derivatives, coumarins, flavonoids, lignans, disaccharide and a complex formed between silver and the solvent (AgCH3CN+) were identified. Using DLS, the AgNPs presented an average hydrodynamic size of 45.91 nm. TEM determined the spherical shape of the AgNPs, presenting diameters in the range of 30 to 60 nm. The biosynthesized AgNPs showed higher antibacterial activity against Escherichia coli and Staphylococcus aureus than the total extract, the methanolic fraction and pure methanol. The polynomial model in the biosynthesis was validated with an adequate fitting representing the experimental data of the process. The most significant variables for the model obtained were the reaction pH (X 2) and the concentration of the precursor salt AgNO 3 (X 6). Conclusions: The synthesized AgNPs offer a viable option for further development due to the presence of bioactive compounds, adequate characterization and antibacterial activity.

Evaluation of the Heart Rhythm Coherence Ratio During Sleep: A Pilot Study With Polysomnography.

The psychophysiological coherence model proposes that a heart rhythm pattern, known as heart rhythm coherence (HRC), is associated with dominant parasympathetic activity and the entrainment of respiratory function, blood pressure, and heart rhythms. Although the HRC pattern has primarily been assessed during wakefulness, changes in cardiac and autonomic activity that occur during sleep stages can also be associated with the HRC pattern. The objective of this study was to examine whether any differences in the HRC pattern could be detected among various sleep stages. Eighteen healthy young individuals participated in this study. Two consecutive polysomnographic (PSG) recordings were obtained from each participant, several segments of cardiac activity were obtained from the second PSG. The HRC pattern was quantitatively evaluated by calculating the HRC ratio (HRCR). The highest peaks in the coherence band (Coher-Peak), 0.1-Hz index, respiratory sinus arrhythmia (RSA), and heart rate (HR) were evaluated. A Friedman test showed significant differences among sleep stages in the Coher-Peak, 0.1-Hz index, RSA, and HR; the Coher-Peak and RSA values were lower in rapid eye movement (REM) sleep, while the 0.1-Hz and HR values were higher in REM sleep. Post hoc analyses identified significant differences between the N2 and REM sleep stages. Among the various sleep stages, HR and RSA measurements behaved independently of the HRC pattern, and the HRC pattern did not appear to be associated with the 0.1 Hz frequency. Further studies are required to identify the characteristics of the HRC pattern during sleep.

Research on aging during the Venezuelan humanitarian crisis: the experience of the Maracaibo aging study.

BACKGROUND: Venezuela is in the throes of a complex humanitarian crisis that is one of the worst in decades to impact any country outside of wartime. This case analysis describes the challenges faced by the ongoing Maracaibo Aging Study (MAS) during the deteriorating conditions in Venezuela. When the MAS began in 1997, it focused on memory-related disorders. Since then, strategic planning and proactive community participation allowed us to anticipate and address logistical, funding, and ethical challenges, and facilitated the enrollment and retention of more than 2500 subjects over 55 years of age. All participants, who are residents of the city of Maracaibo, Venezuela, underwent various assessments on several occasions. Here, we discuss how our approach to implementing a longitudinal, population-based study of age-related conditions has allowed our research program to continue throughout this period of political, economic, and social upheaval. DISCUSSION: As the social context in Venezuela became more complicated, new challenges emerged, and strategies to sustain the study and participation were refined. We identified five main mechanisms through which the evolving humanitarian crisis has affected implementation of the MAS: 1) community dynamics; 2) morale of researchers, staff, and participants; 3) financial feasibility; 4) components of the research process; and 5) impact on the health of staff, participants, and their families. Strategies to compensate for the impact on these components were implemented, based on inputs from community members and staff. Improved communication, greater involvement of stakeholders, broadening the scope of the project, and strengthening international collaboration have been the most useful strategies. Particular demands emerged, related to the increased mortality and comorbidities of participants and staff, and deterioration of basic services and safety. CONCLUSION: Although the MAS has faced numerous obstacles, it has been possible to continue a longitudinal research project throughout the humanitarian crisis, because our research team has engaged the community deeply and developed a sense of mutual commitment, and also because our project has provided funding to help keep researchers employed, somewhat attenuating the brain drain.

Total Plasma Homocysteine and Depressive Symptoms in Older Hispanics.

BACKGROUND: Very few studies have investigated the association between total plasma homocysteine (tHcy) and depressive symptoms in older Hispanics. OBJECTIVE: To test the hypothesis that high tHcy associates with depressive symptoms in older Hispanics. METHODS: A total of 1,418 participants .55 years old from the Maracaibo Aging Study (MAS) underwent standardized neurological, neuropsychiatric, and cardiovascular assessments. The Neuropsychiatric Inventory Depression Subscale (NPId) was used to assess the burden of depressive symptoms. The tHcy levels and other biochemical parameters in blood samples were measured. Univariate and multivariate logistic regression models were applied. RESULTS: Participants with depressive symptoms had higher levels of tHcy than those without (15.1 versus 13.9 µmol/L; p = 0.009). Elevated tHcy levels were associated with depressive symptoms after adjusting for age, sex, education, smoking, diabetes, hypertension, alcohol intake, stroke, and dementia (OR = 1.58; 95% CI, 1.18-2.12). CONCLUSION: Elevated levels of tHcy were associated with depressive symptoms in older Hispanics living under the nutritional and environmental conditions of a developing country.

Neuropsychiatric Symptoms Among Hispanics: Results of the Maracaibo Aging Study.

BACKGROUND: Neuropsychiatric symptoms play an important role in diagnosing and clinical follow-up of cognitive impairment and dementia. OBJECTIVE: We investigated the relationship between neuropsychiatric symptoms, cognitive impairment, and dementia in Hispanics. METHODS: We included 529 participants (age ≥40 years) from the Maracaibo Aging Study with standardized neuropsychiatric assessments, including the Neuropsychiatric Inventory (NPI). Based on the Clinical Dementia Rating and the Mini-Mental State Examination scores, participants' cognitive status was categorized into normal cognition, mild/moderate, and severe cognitive impairment. Diagnosis of dementia was established in a consensus conference. Statistical analyses included multivariable logistic regression models and area under the curve (AUC). RESULTS: The mean age of participants was 59.3 years, and 71.8%were women. The proportion of dementia was 6.8%. Disturbed sleep, anxiety, and depression were the most common neuropsychiatric symptoms in the study sample. In crude analyses, the proportions of hallucinations, aberrant motor behavior, agitation/aggression, apathy, delusions, irritability, eating disturbance, depression, and euphoria were differently distributed among cognitive status groups (p < 0.05). After accounting for confounders, aberrant motor behavior and agitation/aggression remained significantly associated with cognitive impairment and dementia (p < 0.05). The inclusion of the NPI domains significantly improved the AUC to discriminate severe cognitive impairment and dementia compared to a basic model that included sex, age, education, alcohol, obesity, serum glucose, total cholesterol, hypertension, and stroke. CONCLUSION: Neuropsychiatric symptoms are associated with severe cognitive impairment and dementia. The addition of NPI items to the global cognitive assessment might help early detection of dementia in primary care settings.

Nighttime Blood Pressure Interacts with APOE Genotype to Increase the Risk of Incident Dementia of the Alzheimer's Type in Hispanics.

BACKGROUND: Dementia of the Alzheimer's type (DAT) impacts Hispanics disproportionately, with almost a twofold elevated risk of developing DAT, as well as earlier onset of the disease, than in non-Hispanic Whites. However, the role of main risk factors for DAT, such as APOE-ɛ4 and blood pressure (BP) levels, remains uncertain among Hispanics. OBJECTIVE: To investigate the association of APOE-ɛ4 and BP levels, measures with 24-h ambulatory BP monitoring, with incidence of DAT in an elderly cohort of Hispanics. METHODS: 1,320 participants from the Maracaibo Aging Study, free of dementia at the baseline, and with ambulatory BP measurements and APOE genotype available were included. Adjusted Cox proportional models were performed to examine 1) the incidence of DAT and 2) the relationship between BP levels and DAT according to APOE genotypes. Models were adjusted by competing risk of death before the onset of DAT. Model performance was assessed by likelihood test. RESULTS: The average follow-up time was 5.3 years. DAT incidence was 5.8 per 1000 person-year. APOE-ɛ4 carriers had a higher risk of DAT. In unadjusted analyses, conventional, 24-h, and nighttime systolic BP levels were significantly higher in participants who developed DAT and of APOE-ɛ4 carriers (p < 0.05). After adjustment for competing risks, only higher nighttime systolic BP was associated with DAT incidence, but only among subjects carrying APOE-ɛ4. CONCLUSION: In this Hispanic population, both APOE-ɛ4 genotype and assessment of nocturnal systolic BP (rather than diurnal or office BP) were necessary to estimate DAT risk.

Risk Factors for Orthostatic Hypotension: Differences Between Elderly Men and Women.

BACKGROUND: Orthostatic hypotension (OH) occurs when mechanisms regulating blood pressure (BP) levels after standing-up are altered. It is unclear how prevalence and risk factors for OH are different between sexes. We aimed to investigate sex differences in prevalence and risk factors for OH elderly individuals. METHODS: We included 882 participants from Maracaibo Aging Study. OH was a sustained reduction of ≥20 mm Hg in systolic BP, ≥10 mm Hg in diastolic BP, or both, after 3 minutes of changing positions from supine to standing. Multivariable logistic regression models were used to examine the relationships among risk factors for OH in men and women considering interaction sex-term and stratified by sex. RESULTS: The mean age was 66.7 ± 8.5 years, being similar by sex. Women and men 55-74 years had similar prevalence of OH+ (18.5% vs. 20.9%, respectively). After 75 years, the proportion of women with OH+ was lower than men (11% vs. 30%, respectively). Hypertension, specifically systolic BP ≥140 mm Hg, and high pulse pressure (PP) were related with OH+ accounted by interaction sex-term, while diastolic BP ≥90 mm Hg, antihypertensive treatment, body mass index (BMI), diabetes mellitus and age were not. Systolic BP ≥140 mm Hg increases the risk of OH only among women, while BMI showed an inverse association in both sexes. CONCLUSIONS: Although the prevalence of OH is similar in both sexes, there are different risk factors associated by sex. Systolic BP ≥140 mm Hg was associated with increased risk of OH only with women while BMI was a protective factor for OH in men and women.

Glaucomatous Optic Neuropathy Associated with Nocturnal Dip in Blood Pressure: Findings from the Maracaibo Aging Study.

PURPOSE: To determine which nocturnal blood pressure (BP) parameters (low levels or extreme dipper status) are associated with an increased risk of glaucomatous damage in Hispanics. DESIGN: Observational cross-sectional study. PARTICIPANTS: A subset (n = 93) of the participants from the Maracaibo Aging Study (MAS) who met the study eligibility criteria were included. These participants, who were at least 40 years of age, had measurements for optical tomography coherence, visual field (VF) tests, 24-hour BP, office BP, and intraocular pressure <22 mmHg. METHODS: Univariate and multivariate logistic regression analyses under the generalized estimating equations (GEE) framework were used to examine the relationships between glaucomatous damage and BP parameters, with particular attention to decreases in nocturnal BP. MAIN OUTCOME MEASURES: Glaucomatous optic neuropathy (GON) based on the presence of optic nerve damage and VF defects. RESULTS: The mean age was 61.9 years, and 87.1% were women. Of 185 eyes evaluated, 19 (26.5%) had signs of GON. Individuals with GON had significantly lower 24-hour and nighttime diastolic BP levels than those without. However, results of the multivariate GEE models indicated that the glaucomatous damage was not related to the average systolic or diastolic BP levels measured over 24 hours, daytime, or nighttime. In contrast, extreme decreases in nighttime systolic and diastolic BP (>20% compared with daytime BP) were significant risk factors for glaucomatous damage (odds ratio, 19.78 and 5.55, respectively). CONCLUSIONS: In this population, the link between nocturnal BP and GON is determined by extreme dipping effects rather than low nocturnal BP levels alone. Further studies considering extreme decreases in nocturnal BP in individuals at high risk of glaucoma are warranted.

Building capacity for dementia care inLatin America and the Caribbean / Construção de capacidade para atendimento de pacientes com demência em América Latina E no Caribe

Latin America and the Caribbean (LAC) have limited facilities and professionals trained to diagnose, treat, and support people with dementia and other forms of cognitive impairment. The situation for people with dementia is poor, and worsening as the proportion of elderly in the general population is rapidly expanding. We reviewed existing initiatives and provided examples of actions taken to build capacity and improve the effectiveness of individuals, organizations, and national systems that provide treatment and support for people with dementia and their caregivers. Regional barriers to capacity building and the importance of public engagement are highlighted. Existing programs need to disseminate their objectives, accomplishments, limitations, and overall lessons learned in order to gain greater recognition of the need for capacity-building programs.

América Latina e Caribe (ALC) têm instalações e profissionais treinados para diagnosticar, tratar e apoiar as pessoas com demência e outras formas de comprometimento cognitivo limitado. A situação para as pessoas com demência é pobre, e piora quando a proporção de idosos na população em geral está se expandindo rapidamente. Revisamos as iniciativas já existentes, com exemplos de medidas tomadas para fortalecer a capacidade e melhorar a eficácia dos indivíduos, organizações e sistemas nacionais que fornecem tratamento e apoio às pessoas com demência e seus cuidadores. As barreiras regionais ao reforço das capacidades e a importância do engajamento público são realçados. Os programas existentes precisam divulgar seus objetivos, realizações, limitações e lições globais aprendidas a fim de obter maior reconhecimento da necessidade de programas de capacitação.

Building capacity for dementia care in Latin America and the Caribbean.

Latin America and the Caribbean (LAC) have limited facilities and professionals trained to diagnose, treat, and support people with dementia and other forms of cognitive impairment. The situation for people with dementia is poor, and worsening as the proportion of elderly in the general population is rapidly expanding. We reviewed existing initiatives and provided examples of actions taken to build capacity and improve the effectiveness of individuals, organizations, and national systems that provide treatment and support for people with dementia and their caregivers. Regional barriers to capacity building and the importance of public engagement are highlighted. Existing programs need to disseminate their objectives, accomplishments, limitations, and overall lessons learned in order to gain greater recognition of the need for capacity-building programs.

Controlling urban air pollution caused by households: uncertainty, prices, and income.

We examine the control of air pollution caused by households burning wood for heating and cooking in the developing world. Since the problem is one of controlling emissions from nonpoint sources, regulations are likely to be directed at household choices of wood consumption and combustion technologies. Moreover, these choices are subtractions from, or contributions to, the pure public good of air quality. Consequently, the efficient policy design is not independent of the distribution of household income. Since it is unrealistic to assume that environmental authorities can make lump sum income transfers part of control policies, efficient control of air pollution caused by wood consumption entails a higher tax on wood consumption and a higher subsidy for more efficient combustion technologies for higher income households. Among other difficulties, implementing a policy to promote the adoption of cleaner combustion technologies must overcome the seemingly paradoxical result that efficient control calls for higher technology subsidies for higher income households.

autismo a la resurrección : propuesta de reforma de la Central Obrera Boliviana

Contiene: 1. Marco histórico general. 2. La C.O.B. y el retorno a la democracia. 3. Tensionamiento entre democracia y movimiento sindical. 4. Efectos del ajsute estructural. 5. Nuevos actores sociales. 6. Democracia y neoliberalismo. 7. Etapas de la vida política contemporánea. 8. Una breve reseña de los congresos de la C.O.B.

Trabajadores zafreros

Contiene: 1. La agroindustria en Bolivia. 2. Las organizaciones sindicales de los zafreros. 3. ¿Que es la zafra de la caña de azúcar?. 4. Las precarias condiciones de trabajo. 5. La discriminación empezó con ley del trabajo. 6. Contratos que burlan los derechos laborales. 7. El enganche: una máquina moderna de explotación. 8. Accidentes de trabajo fatales y frecuentes. 9. La mujer en la zafra: trabajo duro sin renumeración. 10. Niños también explotados.

Meningioma espinal extradural que nace de una raíz nerviosa torácica / Extradural spinal meningioma arising from a thoracic nervous root

Los meningiomas dentro de los tumores raquídeos (espinales) ocupan el segundo lugar en frecuencia, no obstante, se ven superados por los schwanomas. Los meningiomas extradurales son raros y aquellos originados de la meninge de una raíz nerviosa lo son aun más. Se presenta el caso de una paciente del sexo femenino con un tumor extradural dependía de la raíz nerviosa de T5; clínica y radiológicamente se comportó como un schwanoma, no fue hasta el hallazgo transoperatorio y el reporte histopatológico cuando se aclaro que se trataba de un meningioma. Se hace una revisión de la literatura.

Schwanoma intramedular cervical / Cervical intramedullary schwannoma

Los schwanomas o neurilemomas espinales representan aproximadamente el 30 por ciento de todas las neoplasias intraespinales primarias. La localización intramedular de estos es muy rara. Se presenta el caso de un paciente del sexo masculino a quien se le diagnosticó y trató un schwanoma intramedular a nivel cervical. Se hace énfasis en la importancia de la biopsia transoperatoria.

Construyendo el futuro

Contiene: 1. Los contructores en la historia. 2. Aporte al país. 3. Aporte al empleo. 4. La migración rural. 5. Normas y medidas de seguridad. 6. Ley de accidentes de trabajo y ley general de trabajo. 7. Surgimiento de la ley general de higiene, seguridad ocupacional y bienestar. 8. Accidentes de trabajo. 9. Condiciones de trabajo. 10. El trabajo de la mujer.

Imprimiendo la historia

Contiene: 1. Reivindicaciones revolucionarias y caracter fundamentalmente conservador de las organizaciones sindicales. 2. El transfondo ético y ecológico de la temática. 3. La visión campesina de la problemática. 4. La visión de los dirigentes sindicales y de los miembros de UMOPAR.