[Cardiovascular prevention in primary care in crisis situations: multicenter comparative study before, during and after the SARS-COVID-19 pandemic]. / Prevención cardiovascular en Atención Primaria en situación de crisis: estudio comparativo multicéntrico antes, durante y después de la pandemia por SARS-COVID-19.

OBJECTIVE: To assess whether the appearance of a crisis situation such as the one caused by the SARS-COV-2 pandemic, together with the organizational changes adopted in Primary Care, have influenced the implementation of cardiovascular preventive activities in patients aged 40 to 74 years. DESIGN: Retrospective multicenter descriptive study for three years (2019-2022) in Primary Care. SETTING: 35 health centers of the Primary Care of the Northern Assistance Directorate of Madrid. PARTICIPANTS: 1008 patients of both sexes between 40 and 74 years with diagnosed of hypertension, Diabetes Mellitus and/or dyslipidemia. METHOD: The variables analyzed from the computerized clinical history were lifestyle activities (consumption of tobacco, alcohol, consumption of Mediterranean diet and exercise) considering 3 of the 4 parameters optimal; examination data (blood pressure record) and analytical record (glycemia, hbA1c, total cholesterol, HDL, LDL)considering 4 of the 5 parameters optimal. Differences are analyzed between based pre-pandemic (03/15/2019-03/14/2020), pandemic (03/15/2020-03/14/2021), and transition (03/15/2022-03/14/2022). STATISTICAL ANALYSIS: MC Nemar's test to compare the main variables between the study periods. RESULTS: Data from 1008 patients are collected. The registration of preventive activities on lifestyle was 180 patients (17.9%) (IC95%: 0,155-0,204) in pre-pandemic, 29 patients (2.9%) (IC 95%: 0,019-0,041) in pandemic and 55 patients (5.5%) (IC 95%: 0,041-0,070) in the transition stage (p < 0.05). Exploration was registered in 393 patients (39%) (IC95%: 0,360-0,421) in the pre-pandemic, 133 patients 13,2% (IC 95%: 0,112-0,154) in the pandemic, and 218 patients (21,6%) (IC 95%: 0,191-0,243) in the transition (p < 0.05). The analytical record was 33 patients (3.3%) (IC955: 0,023-0,046), 10 patients (1%) (IC95%: 0,005-0,018) and 23 patients (2.3%) (IC95%: 0,015-0,034) respectively in each phase with one (P < 0.05). CONCLUSIONS: Activities on lifestyle, physical examination, and laboratory test as part of the cardiovascular prevention strategy are scarce in the prepandemic period and decrease drastically during the pandemic, at the first level of care.

Evaluation and selection of indicators for land degradation and desertification monitoring: methodological approach.

An approach to derive relationships for defining land degradation and desertification risk and developing appropriate tools for assessing the effectiveness of the various land management practices using indicators is presented in the present paper. In order to investigate which indicators are most effective in assessing the level of desertification risk, a total of 70 candidate indicators was selected providing information for the biophysical environment, socio-economic conditions, and land management characteristics. The indicators were defined in 1,672 field sites located in 17 study areas in the Mediterranean region, Eastern Europe, Latin America, Africa, and Asia. Based on an existing geo-referenced database, classes were designated for each indicator and a sensitivity score to desertification was assigned to each class based on existing research. The obtained data were analyzed for the various processes of land degradation at farm level. The derived methodology was assessed using independent indicators, such as the measured soil erosion rate, and the organic matter content of the soil. Based on regression analyses, the collected indicator set can be reduced to a number of effective indicators ranging from 8 to 17 in the various processes of land degradation. Among the most important indicators identified as affecting land degradation and desertification risk were rain seasonality, slope gradient, plant cover, rate of land abandonment, land-use intensity, and the level of policy implementation.

Evaluation and selection of indicators for land degradation and desertification monitoring: types of degradation, causes, and implications for management.

Indicator-based approaches are often used to monitor land degradation and desertification from the global to the very local scale. However, there is still little agreement on which indicators may best reflect both status and trends of these phenomena. In this study, various processes of land degradation and desertification have been analyzed in 17 study sites around the world using a wide set of biophysical and socioeconomic indicators. The database described earlier in this issue by Kosmas and others (Environ Manage, 2013) for defining desertification risk was further analyzed to define the most important indicators related to the following degradation processes: water erosion in various land uses, tillage erosion, soil salinization, water stress, forest fires, and overgrazing. A correlation analysis was applied to the selected indicators in order to identify the most important variables contributing to each land degradation process. The analysis indicates that the most important indicators are: (i) rain seasonality affecting water erosion, water stress, and forest fires, (ii) slope gradient affecting water erosion, tillage erosion and water stress, and (iii) water scarcity soil salinization, water stress, and forest fires. Implementation of existing regulations or policies concerned with resources development and environmental sustainability was identified as the most important indicator of land protection.

Andalusian Public Eye-Banks: a decade of continuous improvement.

OBJECTIVES: To show donation data, number of keratoplasties and the changes in transplant indications and techniques that occurred in Andalusia in the period from 2013 to 2022. MATERIALS AND METHODS: The present work is a retrospective and descriptive study that included all keratoplasties performed between January 2013 and December 2022 in Andalusia, as well as the evolution of the cornea donation and transplant activity of the public and private hospitals pertaining to the waiting list management system of the Public Health System of Andalusia. Transplants performed in private centers with corneas from outside Andalusia were excluded. RESULTS: Cornea donation activity in Andalusia in the decade 2013-2022 has experienced a growth of more than 126%, while overall transplant activity has increased by 157% in public hospitals. Penetrating keratoplasty has decreased from 83% in 2013 to 43% in 2022, while lamellar techniques have increased from 17% to 57% in this same period. Since 2018, more lamellar transplants are performed than penetrating transplants. Regarding indications, endothelial conditions already represent the first cause of transplantation. In 2022 alone, the public Andalusian Eye Banks evaluated 1,054 corneas and prepared 281 endothelial grafts. CONCLUSION: In the decade from 2013 to 2022 in Andalusia there has been an increase in donation activity and the number of keratoplasties. The public Eye Banks implementation in this period has played a key role in the widespread adoption of lamellar keratoplasty techniques and has enabled the transition to perform a greater number of lamellar keratoplasties compared to penetrating keratoplasty.

Finerenone protects against progression of kidney and cardiovascular damage in a model of type 1 diabetes through modulation of proinflammatory and osteogenic factors.

The non-steroidal mineralocorticoid receptor antagonist (MRA) finerenone (FIN) improves kidney and cardiovascular outcomes in patients with chronic kidney disease (CKD) in type 2 diabetes (T2D). We explored the effect of FIN in a novel model of type 1 diabetic Munich Wistar Frömter (MWF) rat (D) induced by injection of streptozotocin (15 mg/kg) and additional exposure to a high-fat/high-sucrose diet. Oral treatment with FIN (10 mg/kg/day in rat chow) in diabetic animals (D-FIN) was compared to a group of D rats receiving no treatment and a group of non-diabetic untreated MWF rats (C) (n = 7-10 animals per group). After 6 weeks, D and D-FIN exhibited significantly elevated blood glucose levels (271.7 ± 67.1 mg/dl and 266.3 ± 46.8 mg/dl) as compared to C (110.3 ± 4.4 mg/dl; p < 0.05). D showed a 10-fold increase of kidney damage markers Kim-1 and Ngal which was significantly suppressed in D-FIN. Blood pressure, pulse wave velocity (PWV) and arterial collagen deposition were lower in D-FIN, associated to an improvement in endothelial function due to a reduction in pro-contractile prostaglandins, as well as reactive oxygen species (ROS) and inflammatory cytokines (IL-1, IL-6, TNFα and TGFß) in perivascular and perirenal adipose tissue (PVAT and PRAT, respectively). In addition, FIN restored the imbalance observed in CKD between the procalcifying BMP-2 and the nephroprotective BMP-7 in plasma, kidney, PVAT, and PRAT. Our data show that treatment with FIN improves kidney and vascular damage in a new rat model of DKD with T1D associated with a reduction in inflammation, fibrosis and osteogenic factors independently from changes in glucose homeostasis.

Evidence of Covid-19 lockdown effects on riverine dissolved organic matter dynamics provides a proof-of-concept for needed regulations of anthropogenic emissions.

The fast spread of SARS-CoV-2 virus in Italy resulted in a 3-months lockdown of the entire country. During this period, the effect of the relieved anthropogenic activities on the environment was plainly clear all over the country. Herein, we provide the first evidence of the lockdown effects on riverine dissolved organic matter (DOM) dynamics. The strong reduction in anthropogenic activities resulted in a marked decrease in dissolved organic carbon (DOC) concentration in the Arno River (-44%) and the coastal area affected by its input (-15%), compared to previous conditions. The DOM optical properties (absorption and fluorescence) showed a change in its quality, with a shift toward smaller and less aromatic molecules during the lockdown. The reduced human activity and the consequent change in DOM dynamics affected the abundance and annual dynamics of heterotrophic prokaryotes. The results of this study highlight the extent to which DOM dynamics in small rivers is affected by secondary and tertiary human activities as well as the quite short time scales to return to the impacted conditions. Our work also supports the importance of long-term research to disentangle the effects of casual events from the natural variability.

[Attending COVID-19 patients during the first wave of the pandemic in a Medium Stay Hospital: Variables associated with mortality in hospitalized patients in an acute situation]. / Atención a pacientes COVID-19 durante la primera ola de la pandemia en un hospital de media estancia. Variables asociadas con mortalidad en ingresados en situación aguda.

BACKGROUND AND OBJECTIVE: Spain has been one of the countries most affected by the SARS-CoV-2 pandemic. The objective of this study is to describe the characteristics of the patients treated for COVID-19 at Guadarrama Hospital and to identify the associated mortality factors in those admitted in an acute situation. MATERIAL AND METHODS: Retrospective observational study of COVID-19 patients admitted from 3/15 to 5/15/2020. Sociodemographic, mental, functional, analytical, clinical, radiological and therapeutic variables were collected. Factors associated with mortality were analysed using a bivariate and multivariate study. RESULTS: Two hundred eleven patients were included: 102 (48.3%) in an acute situation and 109 (51.7%) in the convalescent phase, the median (interquartile range) age was 82 (72, 85) years. The most frequent symptoms were fever, cough and respiratory failure. The 89.9% had pneumonia. An acute mortality rate of 26.5% (27/102) was detected and the associated factors were: respiratory failure (P 0.002), Charlson index (ChI)≥3 (P<0.001), CURB≥2 (P 0.011), low SatO2/FiO2 ratio (<0.001), elevated urea (P<0.001) and creatinine (P 0.036), hypoproteinemia (P 0.037) and age (P<0.018). The deceased had a worse functional situation than the survivors (P 0.025). In the multivariate analysis, SatO2/FiO2 ratio (OR: 2.23; 95% CI: 1.07-4.63; P 0.031) and ChI≥3 (OR: 4.25; 95% CI: 1.06-17.04; P 0.041) were independent factors of mortality. CONCLUSIONS: The COVID-19 patients treated were mostly severe cases. The variables associated with mortality were age, respiratory failure, comorbidity, kidney failure, and malnutrition. Respiratory failure and comorbidity outweigh age as independent risk factors for mortality.

Perception of environmental signals by a marine diatom.

Diatoms are a key component of marine ecosystems and are extremely important for the biogeochemical cycling of silica and as contributors to global fixed carbon. However, the answers to fundamental questions such as what diatoms can sense in their environment, how they respond to external signals, and what factors control their life strategies are largely unknown. We generated transgenic diatom cells containing the calcium-sensitive photoprotein aequorin to determine whether changes in calcium homeostasis are used to respond to relevant environmental stimuli. Our results reveal sensing systems for detecting and responding to fluid motion (shear stress), osmotic stress, and iron, a key nutrient that controls diatom abundance in the ocean.

Numerical analysis of cumulative impact of phytoplankton photoresponses to light variation on carbon assimilation.

Light variation in temporal and spatial domains is a key constraint on the photosynthetic performance of phytoplankton. The most obvious responses are the modification of cell pigment content either to improve photocapture or to mitigate photo-damage. Very few studies have analyzed whether light variation significantly alters carbon assimilation, especially in a fluctuating light environment as in the mixed layer of the ocean. We addressed the question using a modeling approach, which allows the reproduction of most of the possible scenarios, obtained with great difficulty from laboratory or field experiments. The complete model is based on the dynamic coupling of a photoacclimation and photodamage-repair responses. In this combined model the virtual phytoplankton is exposed to different light regimes (steady, square wave, sinusoidal light-dark cycles and fluctuating regimes). The results reconcile controversial results on different photoacclimation states achieved during fluctuating light regimes. The model produces a depression of carbon assimilation in any light fluctuating scenario, as compared to steady light regimes, due to the temporal delay between light fluctuations and photoresponses. These results suggest the possibility of selective pressure during evolution, more effective on photoprotective mechanisms than on optimization of light harvesting.

Preparing calibration sets for use in pharmaceutical analysis by NIR spectroscopy.

A new methodology for constructing calibration sets based on the use of laboratory samples encompassing the same variability sources as production samples was developed. The proposed methodology requires the use of no reference method in order to obtain reference values for the analyte; also, it provides more simple and robust calibration models than does the conventional methodology while retaining its predictive capacity. The procedure involves subjecting a set of laboratory samples spanning the desired API concentration range to a granulation treatment similar to that of the industrial process in order to obtain samples with the same physical variability as the production samples. The laboratory samples thus obtained are used to develop partial least squares (PLS1) calibration models in order to quantify the API in a pharmaceutical granulate. Based on the results obtained in this work, NIR spectroscopy is an effective alternative to the reference methods currently used for calibration. The proposed methodology requires no reference values to construct models; therefore, it can be regarded as an absolute analytical method. Also, it confirms the advantages of NIR spectroscopy as part of the process analytical technology (PAT) used by the pharmaceutical industry. A second aim has been the use of the multiplicative curve resolution-alternating least squares (MCR-ALS) algorithm to examine potential polymorphic transformations of the API during granulation.

Pharmaceutical gel analysis by NIR spectroscopy. Determination of the active principle and low concentration of preservatives.

Near infrared spectroscopy has proved highly suitable for the analysis of pharmaceutical formulations. However, its limited sensitivity can severely restrict its scope of application. In this work, we determine the active principle and two preservatives in a pharmaceutical preparation available as a hydrogel. The matrix of the pharmaceutical preparation exhibits strong absorption in the NIR spectral region; also, the two preservatives (parabens) are very similar in chemical and spectral terms, and present at low concentrations in the pharmaceutical. These complications make it rather difficult to accurately quantify the active principle and the preservatives, which can only be accomplished by using an effective design in order to prepare the samples to be included in the calibration set and select the optimum spectral range for measuring each analyte. The evaporation of solvents during the measurement process produces increasing errors related with sample's air exposition; the introductions of new samples with a wider range of the volatile components correct this effect. An ANOVA of the predictions obtained with the new models shows that correct the error due to evaporation. The proposed method was validated for the analytical control of the studied preparation.

[Epidemiological study on chronic renal failure elderly patients on hemodialysis]. / Estudio epidemiológico de pacientes ancianos con insuficiencia renal crónica en hemodiálisis.

Hemodialysis shows an increased prevalence in elderly patients, a population which often presents poor nutrition, high prevalence of cardiovascular, neurological and osteoarticular diseases and psycho-social problems. The objective of this epidemiological, cross-sectional and multicenter study, in patients older than 65 years (n 625) and >75 years (n 558) from 29 Spanish medical institutions was to perform an epidemiological analysis It included demographic information, as well as data regarding chronic renal failure, functional and psychological abilities (Katz Index, Lawton and Karnofsky Scales), dialysis logistics and clinical parameters. The study analyzed data from 1,183 patients (678 female), mean age 75.4+/-5.5 years; mean duration of dialysis 4.3+/-5.1 years (57.7% were referred by the GP: general practitioner). The most frequent etiologies were diabetic nephropathy (21.2%) and vascular renal disease (20.9%). The main comorbilites were high blood pressure (75.6%), Diabetes Mellitus (32.9%) and vascular (29.0%) and osteoarticular (27.3%) diseases. The great majority of patients lived at their family home (85.0%), travelled to their dialysis units alone (80.8%) and by ambulance (56.7%), and it took them less than an hour to arrive (87.5%). Over 75% of patients were fully functional (79.4% under 75 years and 71.6% over 75); meanwhile 10.5% were partially impaired and 13,8% severely impaired. Karnofsky performance scale scored less than 70 in 59.4% of the patients. Analytical parameters rated Hb >or= 11 g/dL for 81.7% of patients; ferritin >or= 100 ng/dL for 98.5%; PTH 150-300 pg/mL for 31.9%; albumin >3.5 g/dL for 75.6%; and serum phosphor <5.5 mg/dL for 70.6%. For the dialysis Kt/V the mean value was 1.4+/-0.3 with a mean duration of dialysis session of 11.7+/-4.0 hours/week. High permeability membranes were used in 52.3% of patients and internal arteriovenous fistula in 74.0%. Around 75% of elderly patients on hemodialysis fulfill age-suitable daily living activities and display adequate dialysis quality parameters.

API determination by NIR spectroscopy across pharmaceutical production process.

The purpose of this research was to demonstrate the ability of reflectance near-infrared (NIR) spectroscopy for quantitative analysis of an active ingredient in different production steps of a solid formulation. The drug is quantified at two different steps of a pharmaceutical process: after granulation and after tablet coating. Calibration samples were prepared by mixing pure drug, excipients, and batch samples (75-120 mg/g active ingredient) using a simple methodology that can be easily carried out in a laboratory. Partial least squares calibration models were calculated in second-derivative mode using the wavelength range 1,134-1,798 nm. The error of prediction for granulated samples was 1.01% and 1.63% for tablets. The results prove that NIR spectroscopy is a good alternative to other, more time-consuming means of analysis for pharmaceutical process monitoring.

[Drug-drug interactions in patients from an internal medicine service]. / Interacciones medicamentosas en pacientes de un servicio de medicina interna.

OBJECTIVE: Drug interactions are the cause of serious adverse reactions, the incidence and morbi-mortality of which are not yet well established. The aim of this study is to carry out an initial estimate of drug interactions in an internal medicine service and to look at any factors associated with their appearance. METHOD: A prospective study was carried out with 120 patients randomly selected from a total of 376 patients admitted to an internal medicine service over a period of three months (February-April 2007). A protocol was designed on an ad-hoc basis to record the interactions. RESULTS: It was observed that 43% of the patients had at least one potential adverse drug interaction and 14% showed associated adverse interactions. The drug with the highest implications in pharmacokinetic interactions was omeprazole when prescribed with acenocoumarol, phenytoin and digoxin. The most significant pharmacodynamic interactions were with associations between NSAID and saluretic-diuretics, insulin and beta-blockers, and aspirin and prednisone. The number of interactions did relate to the number of prescriptions (p < .001), however this was not the case for gender, age and co-morbidity. CONCLUSIONS: Drug interaction is a serious clinical problem which requires the availability of more in depth information and medical attention.

Simultaneous quantitation of five active principles in a pharmaceutical preparation: development and validation of a near infrared spectroscopic method.

A near infrared spectroscopic method for the simultaneous determination of the active principles paracetamol, ascorbic acid, dextrometorphan hydrobromide, caffeine and chlorpheniramine maleate in a pharmaceutical preparation was developed. The five active principles are quantified using a partial least-squares regression method (PLS1). The proposed method is applicable over a wide analyte concentration range (0.04-6.50 wt.%), so it requires careful selection of the calibration set. Also, there is the difficulty of ensuring thorough homogenization of the product. The method was validated in accordance with the ICH standard and the EMEA validation guidelines for NIR spectroscopy by determining its selectivity, linearity, accuracy, precision and robustness. Based on the results, it is an effective alternative to existing choices (HPLC and redox titrimetry) for the same purpose.

[Evaluation of adherence to treatment with calcium and vitamin D in the elderly in a basic health area]. / Evaluación de la adherencia al tratamiento con calcio y vitaminaD en ancianos de una zona básica de salud.

BACKGROUND AND OBJECTIVE: The vitamin D deficiency is high in the elderly population. Calcium and vitamin D supplements is a frequently used measure in individuals at risk for falls and/or fractures. However, this practice has achieved a low level of compliance. The aim is to assess the adherence to treatment with calcium and vitamin D in elders with hypovitaminosis D in an urban area of Madrid. PATIENTS AND METHODS: Intervention study performed on 438 individuals ≥65years from the 'Peñagrande Cohort' with hypovitaminosis D that were treated with calcium and vitamin D. Adherence at 3 and 12 months was assessed using the Morisky-Green and counting of prescriptions written. RESULTS: A total of 413 of the 438 individuals with hypovitaminosis D were analysed (18 patients were not treated because of contraindications, and 7 were considered lost). At 3 and 12 months, 63.9% and 47.2%, respectively, were adherents. After a brief educational intervention, 19.3% of individuals without adherence at 3 months became good compliers when measured at one year. Comorbidity was associated with lower rates of adherence to treatment after one year (46.3% versus 35.2%, P=.027). The main cause of non-adherence to calcium was digestive intolerance, and due to oversights for vitamin D. Concordance between adherence assessed by the Morisky test and counting of prescriptions written was high (Kappa index=69.8%). CONCLUSIONS: Non-adherence to chronic treatment with calcium and vitamin D is a relevant problem in elderly. It is important to assess adherence and implement health education strategies in clinical practice.

Effects of (+/-)-huprine Y and (+/-)-huprine Z, two new anticholinesterasic drugs, on muscarinic receptors.

The cholinergic profile of (+/-)-huprine Y and (+/-)-huprine Z on muscarinic receptors has been determined. Displacement of [3H]-pirenzepine and [3H]-QNB plus pirenzepine was performed in rat hippocampus. Both compounds showed a higher degree of affinity to M1 muscarinic receptors (P < 0.01) than to M2 muscarinic receptors. To determine the M1 agonist or antagonist role of the two huprines, studies of inositol phosphates (IP) production were performed. Both huprines significantly stimulated IP accumulation in a concentration-dependent manner. The reversion of this effect by different antagonists showed that M1 muscarinic receptors were activated by (+/-)-huprine Y and (+/-)-huprine Z, but some other mechanisms, such as alpha1-adrenoceptors or nicotinic receptors, were involved.

Strategy for design NIR calibration sets based on process spectrum and model space: An innovative approach for process analytical technology.

The pharmaceutical industry is under stringent regulations on quality control of their products because is critical for both, productive process and consumer safety. According to the framework of "process analytical technology" (PAT), a complete understanding of the process and a stepwise monitoring of manufacturing are required. Near infrared spectroscopy (NIRS) combined with chemometrics have lately performed efficient, useful and robust for pharmaceutical analysis. One crucial step in developing effective NIRS-based methodologies is selecting an appropriate calibration set to construct models affording accurate predictions. In this work, we developed calibration models for a pharmaceutical formulation during its three manufacturing stages: blending, compaction and coating. A novel methodology is proposed for selecting the calibration set -"process spectrum"-, into which physical changes in the samples at each stage are algebraically incorporated. Also, we established a "model space" defined by Hotelling's T(2) and Q-residuals statistics for outlier identification - inside/outside the defined space - in order to select objectively the factors to be used in calibration set construction. The results obtained confirm the efficacy of the proposed methodology for stepwise pharmaceutical quality control, and the relevance of the study as a guideline for the implementation of this easy and fast methodology in the pharma industry.

A MSFD complementary approach for the assessment of pressures, knowledge and data gaps in Southern European Seas: The PERSEUS experience.

PERSEUS project aims to identify the most relevant pressures exerted on the ecosystems of the Southern European Seas (SES), highlighting knowledge and data gaps that endanger the achievement of SES Good Environmental Status (GES) as mandated by the Marine Strategy Framework Directive (MSFD). A complementary approach has been adopted, by a meta-analysis of existing literature on pressure/impact/knowledge gaps summarized in tables related to the MSFD descriptors, discriminating open waters from coastal areas. A comparative assessment of the Initial Assessments (IAs) for five SES countries has been also independently performed. The comparison between meta-analysis results and IAs shows similarities for coastal areas only. Major knowledge gaps have been detected for the biodiversity, marine food web, marine litter and underwater noise descriptors. The meta-analysis also allowed the identification of additional research themes targeting research topics that are requested to the achievement of GES.

Pemphigus foliaceus sera recognize an N-terminal fragment of bovine desmoglein 1.

It has previously been demonstrated that sera from endemic and nonendemic pemphigus foliaceus patients recognize three immunoreactive fragments of 80, 62, and 45 kilodaltons (kD) from extracts of the envelope fraction of human and bovine epidermis. These polypeptides are also immunoprecipitated by approximately 50% of pemphigus vulgaris sera, but are unreactive with sera from bullous pemphigoid patients or normal controls. The 80-kDa antigen has been shown to be a glycoprotein with N-linked oligosaccharides. Complete removal of the carbohydrate moieties produced a 76-kD polypeptide that continued to react with pemphigus foliaceus autoantibodies in a Ca(++)-dependent manner. To further characterize this antigen/antibody system, the 80-kD pemphigus foliaceus antigen solubilized from a bovine epidermal envelope extract was purified by affinity chromatography using a pemphigus foliaceus patient's immunoglobulin (Ig)G immobilized on agarose. After elution with 0.2 M glycine/HCl, pH 2.8, 5 mM ethylene diaminetetraacetic acid, the polypeptide was mixed with a small amount of 125I-labeled 80-kD antigen, added as a tracer, fractionated by sodium dodecylsulfate-polyacrylamide gel electrophoresis, and electrotransferred onto a polyvinylidene difluoride membrane. The 80-kD band detected by amido black staining and autoradiography was excised and characterized by amino acid sequence analysis. The resulting sequence, EXIKFAAAXREGEXNSKRNPIA, matched perfectly with the N-terminal 22 amino acids of the mature form of bovine desmoglein 1. These findings demonstrate that the 80-kD bovine autoantibody-reactive polypeptide is the glycosylated ectodomain of desmoglein 1, which may contain epitopes recognized by pathogenic autoantibodies.