Dopaminergic denervation and associated MRI microstructural changes in the nigrostriatal projection in early Parkinson's disease patients.

Loss of dopaminergic neurons in the substantia nigra pars compacta (SNc) and a profound reduction of striatal dopamine are two hallmarks of Parkinson's disease (PD). However, it's unclear whether degeneration starts at the neuronal soma or the striatal presynaptic terminals, and how microstructural degeneration is linked to dopaminergic loss is also uncertain. In this study, thirty de novo PD patients and twenty healthy subjects (HS) underwent 6-[18F]-fluoro-L-dopa (FDOPA) PET and MRI studies no later than 12 months from clinical diagnosis. FDOPA uptake rate (Ki), fractional volume of free-water (FW), and iron-sensitive R2* relaxometry were quantified within nigrostriatal regions. Inter-group differences (PD vs HS) were studied using non-parametric statistics and complemented with Cohen's d effect sizes and Bayesian statistics. Correlation analyses were performed exploring biomarker dependencies and their association with bradykinesia scores. PD patients exhibited a significant decline in nigrostriatal dopaminergic activity, being post-commissural putamen (-67%) and posterolateral SNc (-11.7%) the most affected subregions within striatum and SNc respectively. Microstructural alterations (FW) were restricted to the hemisphere corresponding to the most affected side and followed similar spatial gradients as FDOPA Ki (+20% in posterior putamen and +11% in posterolateral SNc). R2* revealed no relevant significant changes. FDOPA and FW were correlated within the posterolateral SNc, and clinical severity was associated with FDOPA Ki loss. The asymmetry between striatal and SNc changes for both dopaminergic depletion and microstructural degeneration biomarkers is consistent with a neurodegenerative process that begins in the striatal terminals before progressing toward the cell bodies in the SNc.

EZH2 mutations at diagnosis in follicular lymphoma: a promising biomarker to guide frontline treatment.

EZH2 is mutated in nearly 25% of follicular lymphoma (FL) cases. Little is known about how EZH2 affects patients' response to therapy. In this context, the aim of this study was to retrospectively analyze the frequency of mutations in EZH2 at diagnosis in tissue and ctDNA in patients with FL and to assess the patients' outcomes after receiving immunochemotherapy, depending on the EZH2 mutation status. Among the 154 patients included in the study, 27% had mutated EZH2 (46% with high-grade and 26% with low-grade FL). Of the mutated tissue samples, the mutation in ctDNA was identified in 44% of cases. EZH2 mutation in ctDNA was not identified in any patient unmutated in the tissue.Unmutated patients who received R-CHOP had significantly more relapses than patients who received R-Bendamustine (16/49 vs. 2/23, p = 0.040). Furthermore, our results show that patients with mutated EZH2 treated with R-CHOP vs. those treated with R-Bendamustine present a lower incidence of relapse (10% vs. 42% p = 0.09 at 4 years), a higher PFS (92% vs. 40% p = 0.039 at 4 years), and higher OS (100% vs. 78% p = 0.039 at 4 years). Based on these data, RCHOP could be a more suitable regimen for mutated patients, and R-bendamustine for unmutated patients. These findings could mean the first-time identification of a useful biomarker to guide upfront therapy in FL.

Long-term experience and Visual Acuity outcomes in Peters Anomaly cases.

PURPOSE: To report the results in a series of Peters Anomaly cases, and propose management and treatment approaches according to the alterations associated with each case. MATERIAL AND METHODS: A retrospective analysis was performed on the records of 27 patients (32 eyes) clinically diagnosed with Peters Anomaly. Each patient was subjected to different treatment modalities according to the type of Peters Anomaly, anywhere from medical follow-up clinics to a Penetrating Keratoplasty procedure (PKP). RESULTS: Of the 27 patients (32 eyes), 74% were male and 26% female, with 18.5% (5) being bilateral and 81.5% (22) unilateral. The mean number of years of follow-up was 10.2 years (Range: 3.5 to 18 years). The results of long-term VA correlate directly with the type of Peters Anomaly. For the total number of patients, the VA results were LogMAR 1.71 ±â€¯1.04. The results by groups were: Type I with only medical monitoring LogMAR 0.3 ±â€¯0, Type I with only Optical Iridectomy (OI) LogMAR 0.97 ±â€¯0.78, Type I with PKP LogMAR 1.22 ±â€¯0.97, Type II without a compromised posterior pole with PKP LogMAR 2.41 ±â€¯0.80, and Type II with a compromised posterior pole with PKP LogMAR 2.56 ±â€¯0.48. CONCLUSIONS: The result of VA and long-term corneal failure is directly related to the type of Peters Anomaly. Patients with Type I who only required medical follow-ups had the most favourable prognosis. Patients who underwent Peripheral Iridectomy followed and patients in which PKP was performed had an inferior prognosis.

Experiencia a largo plazo de pacientes con anomalía de Peters / Long-term experience and Visual Acuity outcomes in Peters Anomaly cases

ObjetivoComunicar los resultados de una serie de casos con anomalía de Peters, y proponer el manejo y sugerencias terapéuticas según alteraciones asociadas.Material y métodosSe analizaron las historias clínicas de 27 pacientes (32 ojos) con diagnóstico clínico de anomalía de Peters, los cuales fueron sometidos a diferentes tratamientos. Distintos parámetros y condiciones asociadas fueron evaluadas: presión intraocular (PIO), agudeza visual (AV), técnica quirúrgica y complicaciones postoperatorias.ResultadosDe los 27 pacientes (32 ojos), 74% sexo masculino y 26% femenino. El promedio de años de seguimiento fue de 10,2 años. La PIO preoperatoria fue de 23 ± 9,21 mmHg y al último control fue de 18,81 ± 7,45 mmHg. El resultado de AV a largo plazo se correlaciona directamente con el tipo de anomalía de Peters. Para el total los resultados de AV fueron LogMAR 1,71 ± 1,04 y por grupos: Tipo I sólo con seguimiento médico LogMAR 0,3 ± 0, Tipo I sólo con iridectomía periférica LogMAR 0,97 ± 0,78, Tipo I con queratoplastia penetrante (QPP) LogMAR 1,22 ± 0,97, Tipo II sin compromiso de polo posterior LogMAR 2,41 ± 0,80 y Tipo II con compromiso de polo posterior LogMAR 2,56 ± 0,48.ConclusionesEl resultado de AV y fracaso del injerto corneal a largo plazo se correlaciona directamente al tipo de anomalía de Peters, con mejor pronóstico la Tipo I en que se realizó sólo seguimiento médico, luego en los que se practicó iridectomía periférica, en los que se realizó QPP los que presentan peor pronóstico visual son con anomalía de Peters Tipo II con compromiso de polo posterior (p = 0.0087).

PurposeTo report the results in a series of Peters Anomaly cases, and propose management and treatment approaches according to the alterations associated with each case.Material and methodsA retrospective analysis was performed on the records of 27 patients (32 eyes) clinically diagnosed with Peters Anomaly. Each patient was subjected to different treatment modalities according to the type of Peters Anomaly, anywhere from medical follow-up clinics to a Penetrating Keratoplasty procedure (PKP).ResultsOf the 27 patients (32 eyes), 74% were male and 26% female, with 18.5% (5) being bilateral and 81.5% (22) unilateral. The mean number of years of follow-up was 10.2 years (Range: 3.5 to 18 years). The results of long-term VA correlate directly with the type of Peters Anomaly. For the total number of patients, the VA results were LogMAR 1.71 ± 1.04. The results by groups were: Type I with only medical monitoring LogMAR 0.3 ± 0, Type I with only Optical Iridectomy (OI) LogMAR 0.97 ± 0.78, Type I with PKP LogMAR 1.22 ± 0.97, Type II without a compromised posterior pole with PKP LogMAR 2.41 ± 0.80, and Type II with a compromised posterior pole with PKP LogMAR 2.56 ± 0.48.ConclusionsThe result of VA and long-term corneal failure is directly related to the type of Peters Anomaly. Patients with Type I who only required medical follow-ups had the most favourable prognosis. Patients who underwent Peripheral Iridectomy followed and patients in which PKP was performed had an inferior prognosis.

Probing the explanation of the muon (g-2) anomaly and thermal light dark matter with the semi-visible dark photon channel.

We report the results of a search for a new vector boson ( A ' ) decaying into two dark matter particles χ 1 χ 2 of different mass. The heavier χ 2 particle subsequently decays to χ 1 and an off-shell Dark Photon A ' ∗ → e + e - . For a sufficiently large mass splitting, this model can explain in terms of new physics the recently confirmed discrepancy observed in the muon anomalous magnetic moment at Fermilab. Remarkably, it also predicts the observed yield of thermal dark matter relic abundance. A detailed Monte-Carlo simulation was used to determine the signal yield and detection efficiency for this channel in the NA64 setup. The results were obtained re-analyzing the previous NA64 searches for an invisible decay A ' → χ χ ¯ and axion-like or pseudo-scalar particles a → γ γ . With this method, we exclude a significant portion of the parameter space justifying the muon g-2 anomaly and being compatible with the observed dark matter relic density for A ' masses from 2 m e up to 390 MeV and mixing parameter ε between 3 × 10 - 5 and 2 × 10 - 2 .

Visibilizando a las cirujanas en Chile / Making female surgeons visible in Chile

Resumen Introducción: La cirugía ha sido tradicionalmente considerada una especialidad masculina. Se desconoce si el aumento en el número de médicas en las últimas décadas ha producido un aumento significativo en el número de cirujanas. Objetivo: Analizar y visibilizar la participación actual e histórica de las mujeres en Medicina y en Cirugía General en Chile. Materiales y Método: Estudio retrospectivo de la cohorte de médicas/os y cirujanas/os egresados de escuelas de medicina chilenas desde el año 1970, complementado con estudio de corte transversal para conocer la información actual de las cirujanas y residentes. Las fuentes de datos fueron los Registros de la Superintendencia de Salud, CONACEM y el Catastro de la Asociación de Cirujanas. Resultados: Ha existido un aumento sostenido de médicas egresadas sobrepasando a sus pares masculinos a partir de 2018. Las cirujanas representan el 15% del total de cirujanas y cirujanos, y este número se ha duplicado por década a partir de los años 70. Actualmente, 33% de los residentes en formación son de género femenino. Las áreas más comunes de desarrollo son cirugía general (35%), y dentro de las subespecialidades: mama, plástica y cabeza y cuello. Conclusión: Las mujeres siguen siendo minoría en cirugía; sin embargo, se ha producido un aumento progresivo y se espera siga la misma tendencia. Es necesario visibilizar la importancia de las cirujanas para que sirvan como modelo a nuevas generaciones de estudiantes y así poder aumentar la representación femenina en la especialidad.

Introduction: Surgery traditionally has been considered a male discipline. It is unknown if the increase in the number of female doctors in the last decades has increased the number of female surgeons. Aim: Is to analyze and make visible the historical and current participation of women in Medicine and Surgery in Chile. Materials and Method: Retrospective cohort study of all medical doctors and surgeons graduated from chilean Universities since 1970 to date, and cross-sectional study to know current information of female surgeons and residents. Source of data were the Registries of Health Superintendence, CONACEM and the Registry of the Female Surgeon Association. Results: There has been a steady increase in the number of graduated female doctors in Chile, surpassing male doctors since 2018. Female surgeons are 15% of all surgeons, and the number has duplicated every decade since 1970s. Currently, 33% of the residents are female. Main area of developing is general surgery (35%), and within subspecialties: Breast, Plastics, and Head and Neck. Conclusions: Women are still underrepresented in Surgery: however, there has been a steady increase and that trend is expected to continue. It is necessary to make visible the importance of female surgeons to be able to increase female representation.

Constraints on New Physics in Electron g-2 from a Search for Invisible Decays of a Scalar, Pseudoscalar, Vector, and Axial Vector.

We performed a search for a new generic X boson, which could be a scalar (S), pseudoscalar (P), vector (V), or an axial vector (A) particle produced in the 100 GeV electron scattering off nuclei, e^{-}Z→e^{-}ZX, followed by its invisible decay in the NA64 experiment at CERN. No evidence for such a process was found in the full NA64 dataset of 2.84×10^{11} electrons on target. We place new bounds on the S, P, V, A coupling strengths to electrons, and set constraints on their contributions to the electron anomalous magnetic moment a_{e}, |Δa_{X}|≲10^{-15}-10^{-13} for the X mass region 1 MeV≲m_{X}≲1 GeV. These results are an order of magnitude more sensitive compared to the current accuracy on a_{e} from the electron g-2 experiments and recent high-precision determination of the fine structure constant.

Primeras cirujanas de Chile / First female surgeons of Chile

Resumen En el año 2020 las cirujanas chilenas se reunieron en torno a la necesidad de trabajar para solucionar varios problemas que aquejan a la labor quirúrgica de la mujer en nuestro país, desde la formación de pregrado en adelante. Algunos de estos problemas son la poca visibilidad de la mujer en cirugía y la falta de reconocimiento de las cirujanas líderes y referentes del pasado y actuales. El objetivo de esta investigación fue indagar quienes habían sido las primeras cirujanas de Chile. La búsqueda fue difícil, ya que la información en la internet es escasa, por lo que se recurrió a entrevistas a discípulos y a algunas de las primeras cirujanas tanto en su especialidad o región del país. La cronología muestra lo reciente que ha sido la llegada de cirujanas a algunas regiones o la escasa representatividad de cirujanas en algunas subespecialidades. Esto se puede entender por barreras legales y culturales que han tenido que enfrentar las mujeres desde el ingreso a la carrera de medicina hasta el poder desarrollar la especialidad en cirugía a lo largo de la historia de este país.

In 2020, Chilean women surgeons gathered to discuss different problems affecting the development of a career in surgery. Through the history of the medicine and surgery in Chile, there have been several legal and cultural barriers that have kept women out of this specialty. One of this problem is the lack of knowledge of who were the first female surgeons and the lack of awareness of that there are women that can be leaders as well as male surgeons. So, generations of medical students and residents continue thinking that surgery might be a man's job. The purpose of this investigation is to reveal who went and are the first women surgeon in this country, not only in their time but also in their specialty, so we all know that there were and there still are pioneers among us.

Nonreciprocal Coupling Induced Self-Assembled Localized Structures.

Chains of coupled oscillators exhibit energy propagation by means of waves, pulses, and fronts. Nonreciprocal coupling radically modifies the wave dynamics of chains. Based on a prototype model of nonlinear chains with nonreciprocal coupling to nearest neighbors, we study nonlinear wave dynamics. Nonreciprocal coupling induces a convective instability between unstable and stable equilibrium. Increasing the coupling level, the chain presents a propagative pattern, a traveling wave. This emergent phenomenon corresponds to the self-assembly of localized structures. The pattern wavelength is characterized as a function of the coupling. Analytically, the phase diagram is determined and agrees with numerical simulations.

Rathke's cleft cyst infections and pituitary abscesses: case series and review of the literature.

PURPOSE: Pituitary abscesses (PAs) are a rare clinical entity which may arise from normal pituitary tissue or underlying lesions within the gland. Rathke's cleft cysts (RCCs) are not commonly associated with the development of PA. METHODS: Retrospective chart review of three patients with PAs within RCCs at a single university center and review of the literature. RESULTS: Three cases are reported. The first case presented with fever and headache and a history of prior surgery due to RCC and a recent respiratory tract infection. The second case had a history of recent skin infections and presented with sudden onset headache and hypopituitarism. In the third case, chronic visual field impairment prompted an ophthalmologic evaluation resulting in a diagnosis of an adenoma and an infected RCC. In all three cases, an endoscopic endonasal approach was performed to drain infected tissue and allowed microbiological identification of gram-positive cocci, followed by treatment with antibiotics for at least three weeks. Cases in the literature are scarce and the diagnosis is usually made intraoperatively due to non-specific manifestations and imaging. PAs arising from underlying pituitary lesions are less common than primary PAs. Differential diagnosis should include pituitary apoplexy, hypophysitis and other cystic lesions. CONCLUSION: PAs occurring in RCCs are infrequent. Clinical manifestations are commonly subacute, without septic symptoms. Imaging is usually non-specific. Preoperative diagnosis is infrequent and a broad differential diagnosis should be considered. Empirical antimicrobial therapy should be initiated and adjusted after obtaining cultures to reduce the rate of recurrence and improve clinical outcomes.

Family function and eating behaviours among Hispanic/Latino youth: results from the Hispanic Community Children's Health Study/Study of Latino Youth (SOL Youth).

OBJECTIVE: To elucidate mechanisms across family function, home environment and eating behaviours within sociocultural context among Hispanic youth. DESIGN: Two models tested via path analysis (youth fruit and vegetable (FV) consumption; empty energy consumption) using data from the Study of Latino Youth (2011-2013). SETTING: Chicago, IL; Miami, FL; Bronx, NY; San Diego, CA. PARTICIPANTS: Youth (8-16-year-olds), n 1466. RESULTS: Youth ate 2·4 servings of FV per d and received 27 % of total energy from empty energies. Perceiving higher acculturative stress was indirectly associated with lower FV consumption via a pathway of low family function and family support for FV (ß = -0·013, P < 0·001) and via lower family closeness and family support (ß = -0·004, P = 0·004). Being >12-year-olds was indirectly associated with lower FV consumption via lower family closeness and family support (ß = -0·006, P < 0·001). Household food security was indirectly associated with greater FV consumption via family closeness and family support (ß = 0·005, P = 0·003). In contrast, perceiving higher acculturative stress was indirectly associated with higher empty energy consumption (via family closeness and family support: ß = 0·003, P = 0·028 and via low family function and low family support: ß = 0·008, P = 0·05). Being older was associated with higher consumption of empty energies via family closeness (related to family support: ß = 0·04, P = 0·016; parenting strategies for eating: ß = 0·002, P = 0·049). CONCLUSIONS: Findings suggest pathways of influence across demographic and sociocultural context, family dynamics and home environment. The directionality of these associations needs confirmation using longitudinal data.

Position statement: asthma in Latin America. IS short-acting beta-2 agonist helping or compromising asthma management?

In Latin-America, with 603 million inhabitants, the average prevalence of asthma is estimated at 17%, but with wide fluctuations, ranging from 5% in some cities (Mexico) to 30% in Costa Rica. The risk of severe exacerbations seems to be higher in Latin America compared with other regions. A majority of patients uses daily quick-relief medication, with the belief that it is the most important treatment because of its rapid onset of action; without treating the underlying inflammation. Overuse of short-acting beta2 agonists (SABAs) is associated with increased risk of asthma deaths in a dose-response manner. Beta2 agonists increase the severity of asthma through enhanced bronchial hyperresponsiveness and reduced lung function. Also, it has been shown that overreliance on SABA delays recognition of a potentially life-threatening asthma attack. We believe that overreliance on SABA in asthma is also an important public health issue. The fact that SABA use in GINA is not supported by a randomized trial but by an anonymous paper; makes us guess that we use SABA just because we are used to do so. In 2019 GINA strategy introduces one of the most important changes in the management of Asthma in the past 30 years, highlighting anti-inflammatory reliever therapy. A combination of low dose ICS/fast action bronchodilator will not only treat symptoms, but more importantly the underlying inflammation, protecting patients from preventable asthma attacks. After 50 years of a SABA centric approach in asthma management, it is time to leave behind a treatment based just on the bronchodilation and tackle the inflammation.

Utilidad de la Determinación de CD25 Soluble en Pacientes con sospecha de Síndrome de Activación Macrofágica / Usefulness of the determination of soluble CD25 in patients with suspected macrophage activation syndrome

El síndrome de activación macrofágica (SAM) presenta criterios clínicos y de laboratorio establecidos. Presentamos el caso de un adolescente varón con debut de Lupus eritematoso generalizado pediátrico grave, donde su manifestación principal fue un SAM y el receptor de interleucina 2 soluble en suero (IL-2rs) o CD25 soluble (CD25s) aumentado resultó clave en la confirmación diagnóstica, en el tratamiento y pronóstico de su enfermedad. Sin embargo, este receptor de citocinas no se mide habitualmente en la práctica clínica.

Macrophage activation syndrome (MAS) presents established clinical and laboratory criteria. We present the case of a male adolescent with the onset of severe pediatric systemic Lupus erythematosus, manifested mainly by MAS and how a laboratory marker, serum soluble interleukin-2 receptor (IL-2rs) or altered soluble CD25(CD25s), played a key role in treatment and prognosis of the disease. However, this cytokine receptor is rarely measured in clinical practice.

Hunting down the X17 boson at the CERN SPS.

Recently, the ATOMKI experiment has reported new evidence for the excess of e + e - events with a mass ∼ 17 MeV in the nuclear transitions of 4 He, that they previously observed in measurements with 8 Be. These observations could be explained by the existence of a new vector X 17 boson. So far, the search for the decay X 17 → e + e - with the NA64 experiment at the CERN SPS gave negative results. Here, we present a new technique that could be implemented in NA64 aiming to improve the sensitivity and to cover the remaining X 17 parameter space. If a signal-like event is detected, an unambiguous observation is achieved by reconstructing the invariant mass of the X 17 decay with the proposed method. To reach this goal an optimization of the X 17 production target, as well as an efficient and accurate reconstruction of two close decay tracks, is required. A dedicated analysis of the available experimental data making use of the trackers information is presented. This method provides independent confirmation of the NA64 published results [1], validating the tracking procedure. The detailed Monte Carlo study of the proposed setup and the background estimate show that the goal of the proposed search is feasible.

Evaluación de carga física en los procesos de empacado de fruta en empresas de la provincia de río negro en la patagonia, argentina

Introducción. Este estudio observacional de corte transversal describió el análisis realizado con una población de ocho operarios, para valorar la exposición a carga física de los trabajadores de la actividad de empaque de fruta en la provincia de Río Negro, Argentina. Métodos. El análisis que se efectuó con los métodos manuales RULA y Check List OCRA, favoreció la evaluación de la exposición a factores de riesgo que pueden ocasionar trastornos en miembros superiores. Resultados. La carga física en las actividades de selección y empaque de fruta alcanzan niveles críticos en movimientos y esfuerzos, están relacionados con más de 15 enfermedades de acuerdo con la OIT y la legislación argentina. Para disminuir el nivel de riesgo, se recomendaron tiempos de descanso, rotación de personal, apoyos corporales adecuados, entre otros. Conclusión. Se recomienda evaluar el proceso de manera sistémica para proponer una intervención integral que mejore el bienestar de los operarios.

Introduction. This cross-sectional observational study described the analysis carried out with a population of eight operators to assess the exposure of fruit packing workers to a physical load in the Rio Negro province, Argentina. Materials and methods. The analysis carried out with the RULA and OCRA Checklist manual methods favored assessing exposure to risk factors that can cause upper limb disorders. Results. According to the ILO and Argentine legislation, the physical load in the fruit selection and packing activities reaches critical levels in movements and efforts; they are related to more than 15 diseases. Breaks, staff rotation, adequate body support, among others, are recommended to reduce the level of risk. Conclusion. It is advisable to assess the process systemically to propose a comprehensive intervention that improves the operators' well-being.

Search for Axionlike and Scalar Particles with the NA64 Experiment.

We carried out a model-independent search for light scalar (s) and pseudoscalar axionlike (a) particles that couple to two photons by using the high-energy CERN SPS H4 electron beam. The new particles, if they exist, could be produced through the Primakoff effect in interactions of hard bremsstrahlung photons generated by 100 GeV electrons in the NA64 active dump with virtual photons provided by the nuclei of the dump. The a(s) would penetrate the downstream HCAL module, serving as a shield, and would be observed either through their a(s)→γγ decay in the rest of the HCAL detector, or as events with a large missing energy if the a(s) decays downstream of the HCAL. This method allows for the probing of the a(s) parameter space, including those from generic axion models, inaccessible to previous experiments. No evidence of such processes has been found from the analysis of the data corresponding to 2.84×10^{11} electrons on target, allowing us to set new limits on the a(s)γγ-coupling strength for a(s) masses below 55 MeV.

Front propagation steered by a high-wavenumber modulation: Theory and experiments.

Homogeneously driven dynamical systems exhibit multistability. Depending on the initial conditions, fronts present a rich dynamical behavior between equilibria. Qualitatively, this phenomenology is persistent under spatially modulated forcing. However, the understanding of equilibria and front dynamics organization is not fully established. Here, we investigate these phenomena in the high-wavenumber limit. Based on a model that describes the reorientation transition of a liquid crystal light valve with spatially modulated optical forcing and the homogenization method, equilibria and fronts as a function of forcing parameters are studied. The forcing induces patterns coexisting with the uniform state in regions where the system without forcing is monostable. The front dynamics is characterized theoretically and numerically. Experimental results verify these phenomena and the law describing bistability, showing quite good agreement.

Diagnosis of Taeniosis in rural Venezuelan communities: Preliminary characterization of a Taenia solium specific monoclonal (VP-1) Coproantigen ELISA.

The objective of this study was to identify and treat carriers of adult Taenia solium present in two rural Venezuelan communities through examination of faecal samples by coproscopical analysis, and by the application of a polyclonal and a monoclonal (VP-1) coproantigen ELISA. Both the polyclonal and monoclonal ELISA's were negative when tested with soluble extracts of adults of Ascaris lumbricoides, Hymenolepis nana and Trichuris trichura. The polyclonal ELISA was positive for soluble extracts adults of T. solium and T. saginata, whereas the monoclonal ELISA, which recognizes a glycoprotein, was restricted to T. solium, and was also negative with faecal samples from five cases of T. saginata adult infections. In the first community studied, Potrero Largo (Total population: 300), of 248 faecal samples examined, 2 individuals were positive for Taenia spp eggs by coproscopical analysis and the VP-1 ELISA, and yielded T. solium adults upon purging. In contrast, when the polyclonal coproAg ELISA was applied to the same 248 faecal samples, there were a considerable number of positives. Indeed, seven patients highly positive in the polyclonal ELISA did not yield a Taenia spp upon purging and were negative in the VP-1 ELISA. In the second community studied La Yuca (Total population 560), none of the 333 individuals who donated faeces was positive for Taenia spp eggs. Many, however, were infected with a range of intestinal helminth and protozoan parasites. A total of 76 faecal samples with representative intestinal parasite were then tested in the polyclonal and VP-1 assays. Of these, many gave an unacceptable number of significant optical densities in the polyclonal coproAg ELISA. In contrast, all were negative in the VP-1 ELISA, thus providing evidence for the species specificity of the VP-1 ELISA in faecal samples. These results with the VP-1 coproAg ELISA, although preliminary, justify further validation through the testing of more faecal samples from T. solium and T. saginata adult infected individuals.