The Major Hypotheses of Alzheimer's Disease: Related Nanotechnology-Based Approaches for Its Diagnosis and Treatment

Alzheimer's disease (AD) is a well-known chronic neurodegenerative disorder that leads to the progressive death of brain cells, resulting in memory loss and the loss of other critical body functions. In March 2019, one of the major pharmaceutical companies and its partners announced that currently, there is no drug to cure AD, and all clinical trials of the new ones have been cancelled, leaving many people without hope. However, despite the clear message and startling reality, the research continued. Finally, in the last two years, the Food and Drug Administration (FDA) approved the first-ever medications to treat Alzheimer's, aducanumab and lecanemab. Despite researchers' support of this decision, there are serious concerns about their effectiveness and safety. The validation of aducanumab by the Centers for Medicare and Medicaid Services is still pending, and lecanemab was authorized without considering data from the phase III trials. Furthermore, numerous reports suggest that patients have died when undergoing extended treatment. While there is evidence that aducanumab and lecanemab may provide some relief to those suffering from AD, their impact remains a topic of ongoing research and debate within the medical community. The fact is that even though there are considerable efforts regarding pharmacological treatment, no definitive cure for AD has been found yet. Nevertheless, it is strongly believed that modern nanotechnology holds promising solutions and effective clinical strategies for the development of diagnostic tools and treatments for AD. This review summarizes the major hallmarks of AD, its etiological mechanisms, and challenges. It explores existing diagnostic and therapeutic methods and the potential of nanotechnology-based approaches for recognizing and monitoring patients at risk of irreversible neuronal degeneration. Overall, it provides a broad overview for those interested in the evolving areas of clinical neuroscience, AD, and related nanotechnology. With further research and development, nanotechnology-based approaches may offer new solutions and hope for millions of people affected by this devastating disease.

Rapid Selective Detection and Quantification of β-Blockers Used in Doping Based on Molecularly Imprinted Nanoparticles (NanoMIPs)

Human performance enhancing drugs (PEDs), frequently used in sport competitions, are strictly prohibited by the World Anti-Doping Agency (WADA). Biological samples collected from athletes and regular patients are continuously tested regarding the identification and/or quantification of the banned substances. Current work is focused on the application of a new analytical method, molecularly imprinted nanoparticles (nanoMIPs), to detect and determine concentrations of certain prohibited drugs, such as β-blockers, in water and human urine samples. These medications are used in the treatment of cardiovascular conditions, negative effects of adrenaline (helping to relief stress), and hypertension (slowing down the pulse and softening the arteries). They can also significantly increase muscle relaxation and improve heart efficiency. The new method of the detection and quantification of β-blockers is based on synthesis, characterization, and implementation of nanoMIPs (so-called plastic antibodies). It offers numerous advantages over the traditional methods, including high binding capacity, affinity, and selectivity for target molecules. Additionally, the whole process is less complicated, cheaper, and better controlled. The size and shape of the nanoMIPs is evaluated by dynamic light scattering (DLS) and transmission electron microscope (TEM). The affinity and selectivity of the nanoparticles are investigated by competitive pseudo enzyme-linked immunosorbent assay (pseudo-ELISA) similar to common immunoassays employing natural antibodies. To provide reliable results towards either doping detection or therapeutic monitoring using the minimal invasive method, the qualitative and quantitative analysis of these drugs is performed in water and human urine samples. It is demonstrated that the assay can detect β-blockers in water within the linear range 1 nmol·L^-1-1 mmol·L^-1 for atenolol with the detection limit 50.6 ng mL^-1, and the linear range 1 mmol·L^-1-10 mmol·L^-1 for labetalol with the detection limit of 90.5 ng·mL^-1. In human urine samples, the linear range is recorded in the concentration range 0.1 mmol·L^-1-10 nmol·L^-1 for atenolol and 1 mmol·L^-1-10 nmol·L^-1 for labetalol with a detection limit of 61.0 ng·mL-1 for atenolol and 99.4 ng·mL^-1 for labetalol.

Rehabilitation in adult post-COVID-19 patients in post-acute care with Therapeutic Exercise

COVID-19 patients may experience disability related to Intensive Care Unit (ICU) admission or due to immobilization. We assessed pre-post impact on physical performance of multi-component therapeutic exercise for post-COVID-19 rehabilitation in a post-acute care facility. A 30-minute daily multicomponent therapeutic exercise intervention combined resistance, endurance and balance training. Outcomes: Short Physical Performance Battery; Barthel Index, ability to walk unassisted and single leg stance. Clinical, functional and cognitive variables were collected. We included 33 patients (66.2±12.8 years). All outcomes improved significantly in the global sample (p<0.01). Post-ICU patients, who were younger than No ICU ones, experienced greater improvement in SPPB (4.4±2.1 vs 2.5±1.7, p<0.01) and gait speed (0.4±0.2 vs 0.2±0.1 m/sec, p<0.01). In conclusion, adults surviving COVID-19 improved their functional status, including those who required ICU stay. Our results emphasize the need to establish innovative rehabilitative strategies to reduce the negative functional outcomes of COVID-19.

EmERGE mHealth Platform: Implementation and Technical Evaluation of a Digital Supported Pathway of Care for Medically Stable HIV

In this article, we described a new mobile-Health (mHealth) supported clinical pathway of care for people living with medically stable HIV in terms of platform acceptability, usability and technical feasibility. The EmERGE mHealth platform was codesigned with clinicians and the community, developed using Scrum agile methodology, integrated with hospital information systems and validated in a large prospective cohort study of 2251 participants. The evaluation of this new paradigm of care was conducted using a tailored Health Technology Assessment: the Model for Assessment of Telemedicine Applications. Usability and acceptability were assessed through the System Usability Score and a Patient Reported Experience Measure. The EmERGE platform was successfully deployed across diverse care settings in five European countries and used by 2251 patients and more than 20 clinicians for up to 30 months. Results from the formal evaluation demonstrated that the EmERGE platform is feasible and acceptable, with a high level of usability (median System Usability Score (SUS) 85.0%) and very positive patient-reported experiences (94.2% would recommend to a friend). The EmERGE platform is a secure and General Data Protection Regulation (GDPR)-compliant system with a complete set of functionalities that could be easily adapted to other clinical conditions, clinical sites and health systems thanks to its modular technical architecture.

Molecularly Imprinted Nanoparticles (NanoMIPs) Selective for Proteins: Optimization of a Protocol for Solid-Phase Synthesis Using Automatic Chemical Reactor

Molecularly imprinted polymer nanoparticles (nanoMIPs) are receiving broad interest as robust and highly selective synthetic receptors for a variety of molecules. Due to their stability, inexpensive synthesis and easy implementation, they are considered a promising alternative to antibodies in sensors, diagnostics and separation applications. The most challenging targets for the production of synthetic receptors are proteins due to their fragile nature and the multitude of possible binding sites in their structure. Herein, we describe the modification and optimization of the protocol for synthesis of nanoMIPs with specificity for proteins using the prototype of an automated solid-phase synthesizer. Using an automated system gives an advantage for the simple, fast and fully controlled, reproducible production of nanoMIPs. The molecular imprinting in the reactor is performed using a template covalently immobilized on a solid support, in mild conditions suitable for preserving protein native structure. The validation of the protocol was made by assessing the ability to regenerate a solid-phase, and by measuring affinity and specificity of nanoparticles. As a model protein, we have chosen trypsin since its enzymatic activity can be easily monitored by using a commercial colorimetric assay. Different protocols were tested for their ability to improve the yield of high affinity nanoparticles in the final elution.

The Barcelona-Asymptomatic Intracranial Atherosclerosis (AsIA) study: Subclinical cervico-cerebral stenosis and middle cerebral artery pulsatility index as predictors of long-term incident cognitive impairment

BACKGROUND AND AIMS

We aimed to study subclinical non-invasive vascular markers as predictors of incident long-term cognitive impairment in a longitudinal population-based study.

METHODS

The Barcelona-Asymptomatic Intracranial Atherosclerosis (AsIA) study is a population-based study that included a random sample of 933 Caucasian subjects (mean age 66 years, 64% male) with a moderate-high vascular risk and without history of stroke or dementia. Subclinical carotid and intracranial stenosis was assessed at baseline visit by cervical and transcranial color-coded duplex (TCCD) and confirmed by magnetic resonance angiography. Cervico-cerebral stenosis (CCS) was defined as the presence of extra and/or intracranial stenosis >50%. Baseline middle cerebral artery pulsatility index (MCA-PI) was measured bilaterally by TCCD, and mean PI of both sides was considered for analyses. Subjects were followed-up to determine incident long-term cognitive impairment (mild cognitive impairment or dementia).

RESULTS

After a median of 7.16 [6.91-7.75] years of follow-up, 91 subjects (9.7%) developed cognitive impairment, 27 of them mild cognitive impairment, and 64 dementia. Incidence of cognitive impairment was significantly higher among subjects with subclinical CCS (21.4% versus 9% in those without CCS) and among those with mean MCA-PI>1 (13.5% versus 7.4% in those with MCA-PI<1). In multivariate Cox regression analyses, both CCS and MCA-PI>1 were independently associated with incident cognitive impairment with HR of 2.07 [1.11-3.88] and 1.58 [1.02-2.46], respectively.

CONCLUSIONS

Subclinical cervico-cerebral stenosis and higher MCA-PI are non-invasive neurosonological markers of incident long-term cognitive impairment in our population.

Association between second mesiobuccal missed canals and apical periodontitis in maxillary molars of a Chilean subpopulation

Background

To determine the frequency of missed second mesiobuccal canals (MB2) and apical periodontitis in maxillary molars of a Chilean subpopulation using cone beam computed tomography (CBCT).

Material and Methods

Two previously calibrated operators evaluated CBCTs with a total of 588 upper molars, of which 179 endodontically treated molars were selected. Axial tomographic slices were used to study the frequency and association between the presence of apical periodontitis and untreated MB2 canals.

Results

Of the 179 endodontically treated molars, 45.78% (84) presented MB2 missed canals. Of the upper molars that presented MB2 missed canals, 70% were associated with apical periodontitis, which was statistically significant (p< 0.0001). Sixty-two corresponded to first molars (74%) and 22 to second molars (26%). Of the first molars, 34 (54.8%) presented with apical periodontitis and MB2 missed canals (p< 0.0001), while 12 (54.4%) of the second molars presented this association (p = 0.081).

Conclusions

MB2 missed canals are associated with a high degree of apical periodontitis and may be an important predictor of endodontic prognosis of upper molars. Key words:Endodontics, apical periodontitis, cone beam computed tomography, missed canals, maxillary molars.

Technologies for Monitoring Lifestyle Habits Related to Brain Health: A Systematic Review

Brain health refers to the preservation of brain integrity and function optimized for an individual’s biological age. Several studies have demonstrated that our lifestyles habits impact our brain health and our cognitive and mental wellbeing. Monitoring such lifestyles is thus critical and mobile technologies are essential to enable such a goal. Three databases were selected to carry out the search. Then, a PRISMA and PICOTS based criteria for a more detailed review on the basis of monitoring lifestyle aspects were used to filter the publications. We identified 133 publications after removing duplicates. Fifteen were finally selected from our criteria. Many studies still use questionnaires as the only tool for monitoring and do not apply advanced analytic or AI approaches to fine-tune results. We anticipate a transformative boom in the near future developing and implementing solutions that are able to integrate, in a flexible and adaptable way, data from technologies and devices that users might already use. This will enable continuous monitoring of objective data to guide the personalized definition of lifestyle goals and data-driven coaching to offer the necessary support to ensure adherence and satisfaction.

Pheromone emission patterns and courtship sequences across distinct populations within Anastrepha fraterculus (Diptera-Tephritidae) cryptic species complex

Sexual behavioural isolation can result from sexual selection and represents a relevant factor associated with the speciation process. We analysed the pheromone emission pattern and the courtship of males of five different populations of the Anastrepha fraterculus cryptic complex: Brazil (Vacaria, Tucumán and Piracicaba), Colombia and Peru. The time of pheromone emission was recorded in each population every 30 min during the day. The behavioural sequences of courting were video recorded and analysed using EthoSeq software. Males from different populations have showed different period of pheromone emission - Vacaria, Piracicaba and Tucumán executed calling only during the morning, Colombia only in the afternoon and Peru during both periods. The general frequencies of the courtship units of the males were distinct among the populations. Three groups were formed in the classification from the function of 14 behavioural routines: Vacaria, Piracicaba and Tucumán formed a single group (Brazil-1), while Colombia and Peru formed two distinct groups. In the probabilistic trees generated, the behavioural units that most contributed to the occurrence of copulation were distinct among the three groups formed: Brazil-1 (Contact, Alignment and Arrowhead-1); Colombia (Flying, Mobile, Contact and Alignment); Peru (Flying, Arrowhead-1 and Calling). Our results indicated differences in sexual behaviour that may explain the behavioural isolation found between the distinct groups in addition with the temporal isolation found between the Brazil-1 and Colombia populations. The evolutionary implications for the A. fraterculus cryptic species complex are discussed.

Sinopsis del género Malesherbia (Passifloraceae) en el Perú

Se presentan 15 taxones de Malesherbia que ocurren en el Perú, incluyendo un nuevo registro, Malesherbia auristipulata. Se proporcionan datos actualizados de distribución departamental, rango altitudinal, además de una clave dicotómica para la determinación de las especies.

Molecularly Imprinted Polymers for the Selective Extraction of Bisphenol A and Progesterone from Aqueous Media

This paper describes the development of a novel sorbent for selective extraction of endocrine disruptors (EDs) from aqueous media. The main goal was to obtain sufficient molecularly imprinted polymers (MIPs) for selective detection, preconcentration, and extraction of EDs such as bisphenol A (BPA) and progesterone (PG). Series of MIPs and their analogues, non-molecularly imprinted polymers (NIPs), were synthesised following a non-covalent imprinting strategy based on radical polymerisation. Sets of synthesis were performed in order to optimise variables of the polymerisation including solvent, cross-linker, and template ratio. The retention capacity of MIPs was determined using HPLC in the range of 33.3% to 96.6% and 32.5% to 96% for BPA and PG, respectively. The adsorption mechanism was studied by isothermal and kinetic assays. The kinetic analysis showed a high retention capacity within 15 min of contact. The polymer yield was obtained in the range of 30% to 100%. Additionally, there was no significant cross-reactivity observed upon testing MIPs with structural analogues and other endocrine disruptors instead of target molecules. The results also revealed the high importance of different concentrations of cross-linker and solvent during the polymerisation. Firstly, the pre-organisation of complementary functional groups, which were present in the polymerisation mixture, and secondly, selective cavity formation for target molecules.

Does size matter? Study of performance of pseudo-ELISAs based on molecularly imprinted polymer nanoparticles prepared for analytes of different sizes

Here we evaluate whether the size of the template used to produce molecularly imprinted nanoparticles can affect their performance in pseudo-ELISAs.

Intelligent Therapy Assistant (ITA) for cognitive rehabilitation in patients with acquired brain injury

Background

This paper presents the design, development and first evaluation of an algorithm, named Intelligent Therapy Assistant (ITA), which automatically selects, configures and schedules rehabilitation tasks for patients with cognitive impairments after an episode of Acquired Brain Injury. The ITA is integrated in “Guttmann, Neuro Personal Trainer” (GNPT), a cognitive tele-rehabilitation platform that provides neuropsychological services.

Methods

The ITA selects those tasks that are more suitable for the specific needs of each patient, considering previous experiences, and improving the personalization of the treatment. The system applies data mining techniques to cluster the patients according their cognitive impairment profile. Then, the algorithm rates every rehabilitation task, based on its cognitive structure and the clinical impact of executions done by similar patients. Finally, it configures the most suitable degree of difficulty, depending on the impairment of the patient and his/her evolution during the treatment.

Results

The ITA has been evaluated during 18 months by 582 patients. In order to evaluate the effectiveness of the ITA, a comparison between the traditional manual planning procedure and the one presented in this paper has been done, taking into account: a) the selected tasks assigned to rehabilitation sessions; b) the difficulty level configured for the sessions; c) and the improvement of their cognitive capacities after completing treatment.

Conclusions

The obtained results reveal that the rehabilitation treatment proposed by the ITA is as effective as the one performed manually by therapists, arising as a new powerful support tool for therapists. The obtained results make us conclude that the proposal done by the ITA is very close to the one done by therapists, so it is suitable for real treatments.

Mating compatibility between Bactrocera invadens and Bactrocera dorsalis (Diptera: Tephritidae)

The invasive fruit fly, Bactrocera invadens Drew, Tsuruta & White, is a highly polyphagous fruit pest that occurs predominantly in Africa yet has its origins in the Indian subcontinent. It is extremely morphologically and genetically similar to the Oriental fruit fly, Bactrocera dorsalis (Hendel); as such the specific relationship between these two species is unresolved. We assessed prezygotic compatibility between B. dorsalis and B. invadens using standardized field cage mating tests, which have proven effectiveness in tephritid cryptic species studies. These tests were followed by an assessment of postzygotic compatibility by examining egg viability, larval and pupal survival, and sex ratios of offspring produced from parental and subsequent F1 crosses to examine for hybrid breakdown as predicted under a two-species hypothesis. B. dorsalis was sourced from two countries (Pakistan and China), and each population was compared with B. invadens from its type locality of Kenya. B. invadens mated randomly with B. dorsalis from both localities, and there were generally high levels of hybrid viability and survival resulting from parental and F1 crosses. Furthermore, all but one hybrid cross resulted in equal sex ratios, with the single deviation in favor of males and contrary to expectations under Haldane's rule. These data support the hypothesis that B. dorsalis and B. invadens represent the same biological species, an outcome that poses significant implications for pest management and international trade for sub-Saharan Africa.

Prognostic value of changes in resting-state functional connectivity patterns in cognitive recovery after stroke: A 3T fMRI pilot study

Resting‐state studies conducted with stroke patients are scarce. First objective was to explore whether patients with good cognitive recovery showed differences in resting‐state functional patterns of brain activity when compared to patients with poor cognitive recovery. Second objective was to determine whether such patterns were correlated with cognitive performance. Third objective was to assess the existence of prognostic factors for cognitive recovery. Eighteen right‐handed stroke patients and eighteen healthy controls were included in the study. Stroke patients were divided into two groups according to their cognitive improvement observed at three months after stroke. Probabilistic independent component analysis was used to identify resting‐state brain activity patterns. The analysis identified six networks: frontal, fronto‐temporal, default mode network, secondary visual, parietal, and basal ganglia. Stroke patients showed significant decrease in brain activity in parietal and basal ganglia networks and a widespread increase in brain activity in the remaining ones when compared with healthy controls. When analyzed separately, patients with poor cognitive recovery (n = 10) showed the same pattern as the whole stroke patient group, while patients with good cognitive recovery (n = 8) showed increased activity only in the default mode network and fronto‐temporal network, and decreased activity in the basal ganglia. We observe negative correlations between basal ganglia network activity and performance in Semantic Fluency test and Part A of the Trail Making Test for patients with poor cognitive recovery. A reverse pattern was observed between frontal network activity and the abovementioned tests for the same group. Hum Brain Mapp 35:3819–3831, 2014. © 2014 The Authors. Human Brain Mapping published by Wiley Periodicals, Inc.

Cognitive neurorehabilitation based on interactive video technology

Cognitive impairment is the main cause of disability in developed societies. New interactive technologies help therapists in neurorehabilitation in order to increase patients' autonomy and quality of life. This work proposes Interactive Video (IV) as a technology to develop cognitive rehabilitation tasks based on Activities of Daily Living (ADL). ADL cognitive task has been developed and integrated with eye-tracking technology for task interaction and patients' performance monitoring.

Acceptability of pre-exposure prophylaxis as an HIV prevention strategy: barriers and facilitators to pre-exposure prophylaxis uptake among at-risk Peruvian populations

This study examined pre-exposure prophylaxis (PrEP) acceptability among female sex workers, male-to-female transgendered persons and men who have sex with men in Lima, Peru. Focus groups explored social issues associated with PrEP acceptability and conjoint analysis assessed preferences among eight hypothetical PrEP scenarios with varying attribute profiles and their relative impact on acceptability. Conjoint analysis revealed that PrEP acceptability ranged from 19.8 to 82.5 out of a possible score of 100 across the eight hypothetical PrEP scenarios. Out-of-pocket cost had the greatest impact on PrEP acceptability (25.2, P < 0.001), followed by efficacy (21.4, P < 0.001) and potential side-effects (14.7, P < 0.001). Focus group data supported these findings, and also revealed that potential sexual risk disinhibition, stigma and discrimination associated with PrEP use, and mistrust of health-care professionals were also concerns. These issues will require careful attention when planning for PrEP roll-out.

Upper limb portable motion analysis system based on inertial technology for neurorehabilitation purposes

Here an inertial sensor-based monitoring system for measuring and analyzing upper limb movements is presented. The final goal is the integration of this motion-tracking device within a portable rehabilitation system for brain injury patients. A set of four inertial sensors mounted on a special garment worn by the patient provides the quaternions representing the patient upper limb’s orientation in space. A kinematic model is built to estimate 3D upper limb motion for accurate therapeutic evaluation. The human upper limb is represented as a kinematic chain of rigid bodies with three joints and six degrees of freedom. Validation of the system has been performed by co-registration of movements with a commercial optoelectronic tracking system. Successful results are shown that exhibit a high correlation among signals provided by both devices and obtained at the Institut Guttmann Neurorehabilitation Hospital.

[Vascular risk factors and cognitive performance in patients 50 to 65 years-old]

INTRODUCTION

Vascular risk factors (VRF) have been related to cognitive deficits and an increased risk of dementia. Cognitive impairment is considered to be one of the earliest manifestations of cerebrovascular disease. In Spain there is a high prevalence of VRF, but also one of the lowest incidences of cerebrovascular disease in Europe. This is the first study that investigates the relationship between VRF and cognition in a Spanish sample.

METHODS

A total of 90 people aged between 50-65 years with a low-to-moderate cardiovascular risk underwent a neuropsychological evaluation. None of them had a history of cardiovascular disease. The battery included tests assessing executive, attentional, mnesic, visuospatial and motor-speed/coordination functions. We used correlation and inter-groups comparison to relate VRF to multiple cognitive domains0120.

RESULTS

Higher stroke risk was significantly related to a lowered profile in visuo-constructive functions and motor-speed/coordination. Moreover, the group with moderate cardiovascular risk showed a lower performance in visuoconstructive functions compared to the low-risk group. After statistical adjustment for age, sex and years of scholarship VRF were only related to motor-speed/coordination.

CONCLUSIONS

In healthy, middle-aged adults, VRF are related with impairment in two cognitive domains. This effect is slight and tends to appear in people with moderate cardiovascular risk.

Is there progressive cognitive dysfunction in Sjögren Syndrome? A preliminary study

OBJECTIVE

The aim of this study was to determine the progression of cognitive dysfunction in primary Sjögren Syndrome (SS).

METHODS

Twelve subjects with SS were compared with ten subjects with migraine and ten healthy controls on neuropsychological, mood and fatigue tests at baseline and 8 years later.

RESULTS

At follow-up, SS subjects performed below subjects with migraine on the Continuous Performance Test (CPT) but did not differ on other tasks. Compared with controls, both clinical groups obtained lower scores on simple reaction time, patients with SS obtained lower scores on the Wisconsin Card Sorting Test (WCST) and patients with migraine performed below controls on the Benton's Judgment of Line Orientation Test (JOLO). Clinical groups did not differ on cognitive changes over time, except that migraine subjects improved on verbal fluency. Compared with baseline, both SS and migraine patients were more impaired on simple reaction time, Trail Making Test part B, Stroop and JOLO. However, they showed higher scores on verbal and visual memory, WCST and CPT reaction time. SS also showed higher levels of depression and fatigue than migraine and controls, with no significant changes over time.

DISCUSSION

Preliminary evidence indicates some cognitive deficits in both SS and migraine following a pattern of fronto-subcortical dysfunction without a significant cognitive decline over time.

Policies around sexual and reproductive health and rights in Peru: conflict, biases and silence

This study is aimed at examining how subsequent Peruvian governments, since 1990, have addressed reproductive rights, HIV/AIDS prevention and treatment, and sexual diversity rights, as well as the drastic policy shifts and its many contradictions. Abortion and contraception consistently generated the deepest public controversies and debates, which made progress in reproductive rights difficult. HIV/AIDS was often portrayed as having the potential to affect everyone, which allowed advocates and activists to achieve some success in advancing HIV/AIDS-related rights. Sexual diversity rights, perceived as a demand made by "others", were generally trivialised and disdained by politicians, officials, and the general population. Positive changes occurred as long as the issue was given a low political and institutional profile. The analysis of policy-making and programme implementation in these three areas reveals that: (1) Weaknesses in national institutional frameworks concerning reproductive health made it possible for governments to adopt two very different (even contradictory) approaches to the issue within the past 15 years; (2) Policies were presented as rights-based in order to garner political legitimacy when, in fact, they evidenced a clear disregard for the rights of individual citizens; and (3) By favouring low-profile "public health" discourses, and marginalising "the sexual" in official policies related to sexuality, advocacy groups sometimes created opportunities for legal changes but failed to challenge conservative powers opposing the recognition of sexual and reproductive rights and the full citizenship of women and sexual minorities.

Complete nucleotide sequence analysis of a Dengue-1 virus isolated on Easter Island, Chile

Dengue-1 viruses responsible for the dengue fever outbreak in Easter Island in 2002 were isolated from acute-phase sera of dengue fever patients. In order to analyze the complete genome sequence, we designed primers to amplify contiguous segments across the entire sequence of the viral genome. RT-PCR products obtained were cloned, and complete nucleotide and deduced amino acid sequences were determined. This report constitutes the first complete genetic characterization of a DENV-1 isolate from Chile. Phylogenetic analysis shows that an Easter Island isolate is most closely related to Pacific DENV-1 genotype IV viruses.

Estimating the number of men who have sex with men in low and middle income countries

OBJECTIVES

To collect and analyse published and unpublished surveillance and research data on the prevalence of same sex sexual activity among male adults (including male-to-female transgenders and sex workers) in low and middle income countries.

METHODS

Key indicators were operationalised (ever sex with a man, sex with a man last year, high risk sex last year (as defined by unprotected anal sex or commercial sex)) and a database was designed for data collection. Searches were conducted (PubMed, databases (US Census Bureau, World Bank, conferences)) and regional informants helped. Reference reports were used to assess the methodology and quality of information in each record. The best data available per region were identified and indicator estimates were used to propose regional range estimates.

RESULTS

Of 561 studies on male sexual behaviour and/or MSM population characteristics, 67 addressed prevalence of sex between men, with diverse numbers per region and virtual unavailability in sub-Saharan Africa, Middle East/North Africa, and the English speaking Caribbean. Overall, data on lifetime prevalence of sex with men (among males) yielded figures of 3-5% for East Asia, 6-12% for South and South East Asia, 6-15% for Eastern Europe, and 6-20% for Latin America. Last year figures were approximately half of lifetime figures, and prevalence of high risk sex among MSM last year was approximately 40-60% in all regions except South Asia, where it is 70-90%.

CONCLUSIONS

Data available on the prevalence of male same sex sexual activity across regions are scarce (non-existent in some areas), with validity and comparability problems. In South and South East Asia, Eastern Europe, and Latin America, a lifetime prevalence of 6-20% was estimated, with smaller figures in East Asia. A cross cultural analysis of terminology and practices is needed, as is continued work on epidemiological and social analysis of male-male sexual practices in societies across regions.

A web-based self-monitoring system for people living with HIV/AIDS

Available evidence indicates that the internet is becoming the main source for delivering information on the prevention, control and treatment of HIV/AIDS. This paper presents a further step in the use of the internet to meet the new challenge of managing HIV as a chronic illness. It describes a work carried out under the SEAHORSE EU project to build and test a Web-based self-monitoring system for HIV/AIDS patient care. The user interface has been carefully designed to provide a high-level of interaction and therefore improve some of the current limitations of Web applications. The system comprises three modules: (1) a patient self-monitoring personal diary, to create a follow-up patient record; (2) a data analysis and visualisation tool; and (3) a section to allow patients to ask for advising and remote doctor support. One of the crucial system design issues has been the system security and users anonymity features required in this clinical domain. A feasibility pilot has been carried out to test the system in three organisations involved in the research project: the Immune Development Trust (London), the Lambeth, Southwark and Lewisham Health Authority (London) and Apoyo Positivo in Madrid. The preliminary results of the system evaluation show the potential validity and usefulness of the tool for helping people living with HIV/AIDS to promote and manage their health and for providing health professionals with new means for tele-monitoring and tele-caring patients.

DNA-interacting proteins in the spermiogenesis of the mollusc Murex brandaris

Sperm chromatin of Murex brandaris (a neogastropod mollusc) undergoes a series of structural transitions during spermiogenesis. The DNA-interacting proteins responsible for these changes as well as the mature protamines present in the ripe sperm nucleus have been characterized. The results reveal that spermiogenic nuclear proteins are protamine precursors that are subjected to a substantial number of small N-terminal deletions that gradually modify their overall charge. The composition of mature protamines is remarkably simple in turn, promoting an efficient and extremely tight packaging of DNA. The pattern of spermiogenic chromatin condensation in M. brandaris clearly departs from that corresponding to vertebrate chromatin.

Molybdophosphoric Acid Adsorption on Titania from Ethanol-Water Solutions

The equilibrium adsorption at 20 degreesC of molybdophosphoric acid solutions, using ethanol-water as solvent, on titania was studied. The molybdenum adsorption isotherm showed a sigmoidal shape; low values of molybdenum adsorbed were observed for final equilibrium concentrations lower than 50 mg Mo/ml, and for higher concentrations, the adsorbed molybdenum amount almost reached a plateau. From this isotherm it could be concluded that the solute-support interaction was not strong. UV-visible and NMR spectra of the solutions before and after the adsorption on titania showed that the species PMo12O3-<INF POS="STACK">40 was present. This species also was observed by DRS in the wet samples and by NMR, FT-IR, and DRS, in the solid samples dried at room temperature and calcined at 255, 310, 365, and 425 degreesC, showing that the thermal stability of molybdophosphoric acid adsorbed on titania is similar to that of the bulk acid. The impregnating solutions and the impregnated solid changed with the time to a bluish color as a consequence of the formation of heteropoly blues which presented Mo6+ partially reduced to Mo5+. The XRD patterns indicated that the species adsorbed onto the support surface are highly dispersed like a noncrystalline form. Copyright 1998 Academic Press.