Clostridium and Cryptosporidium outbreak linked to a splash pad.

BACKGROUND: . Splash pads for recreational purposes are widespread. Using these pads can pose a health risk if they lack installation regulation and water quality supervision. Our aim was to describe a waterborne disease outbreak caused by Clostridium perfringens and Cryptosporidium spp. in a Barcelona district and the measures taken for its control. METHODS: . On August 2018, 71 cases of acute gastroenteritis were detected, affecting people who used a splash pad or were in contact with a user. Microbiological and environmental investigations were carried out. A descriptive analysis of the sample and Poisson regression models adjusted for age and sex were performed, obtaining frequencies, median values, and adjusted prevalence ratios with their 95% confidence intervals. RESULTS: The median age of the cases was 6.7 years, 27 (38%) required medical care, and three (4.2%) were hospitalized. The greater the number of times a person entered the area, the greater the number of symptoms and their severity. Nineteen (76%) of the 25 stool samples collected from cases showed the presence of one or both pathogens. Environmental investigations showed deficiencies in the facilities and identified the presence of both species in the splash pad. Health education and hygiene measures were carried out, and 14 days after the closure of the facilities, no more cases related to the pad were recorded. CONCLUSIONS: . Specific regulations are needed on the use of splash pads for recreational purposes. Until these regulations are in place, these types of facility should comply with the regulations that apply to swimming pools and spas, including those related to the design of the tanks, water recirculation systems, and adequate disinfection systems.

Feasibility of using death certificates for studying place of death in Latin America.

OBJECTIVE: This paper assesses the availability and quality of death certificate data in Latin America and the feasibility of using these data to study place of death and associated factors. METHODS: In this comparative study, we collected examples of current official death certificates and digital data files containing information about all deaths that occurred during 1 year in 19 Latin American countries. Data were collected from June 2019 to May 2020. The records for place of death and associated variables were studied. The criteria for data quality were completeness, number of ill-defined causes of death and timeliness. RESULTS: All 19 countries provided copies of current official death certificates and 18 of these registered the place of death. Distinguishing among hospital or other health care institution, home and other was possible for all countries. Digital data files with death certificate data were available from 12 countries and 1 region. Three countries had data considered to be of high quality and seven had data considered to be of medium quality. Categories for place of death and most of the predetermined factors possibly associated with place of death were included in the data files. CONCLUSIONS: The quality of data sets was rated medium to high in 10 countries. Hence, death certificate data make it feasible to conduct an international comparative study on place of death and the associated factors in Latin America.

Environmentally-driven gene content convergence and the Bacillus phylogeny.

BACKGROUND: Members of the Bacillus genus have been isolated from a variety of environments. However, the relationship between potential metabolism and the niche from which bacteria of this genus have been isolated has not been extensively studied. The existence of a monophyletic aquatic Bacillus group, composed of members isolated from both marine and fresh water has been proposed. Here, we present a phylogenetic/phylogenomic analysis to investigate the potential relationship between the environment from which group members have been isolated and their evolutionary origin. We also carried out hierarchical clustering based on functional content to test for potential environmental effects on the genetic content of these bacteria. RESULTS: The phylogenetic reconstruction showed that Bacillus strains classified as aquatic have evolutionary origins in different lineages. Although we observed the presence of a clade consisting exclusively of aquatic Bacillus, it is not comprised of the same strains previously reported. In contrast to phylogeny, clustering based on the functional categories of the encoded proteomes resulted in groups more compatible with the environments from which the organisms were isolated. This evidence suggests a detectable environmental influence on bacterial genetic content, despite their different evolutionary origins. CONCLUSION: Our results suggest that aquatic Bacillus species have polyphyletic origins, but exhibit convergence at the gene content level.

How To Live with Phosphorus Scarcity in Soil and Sediment: Lessons from Bacteria.

UNLABELLED: Phosphorus (P) plays a fundamental role in the physiology and biochemistry of all living things. Recent evidence indicates that organisms in the oceans can break down and use P forms in different oxidation states (e.g., +5, +3, +1, and -3); however, information is lacking for organisms from soil and sediment. The Cuatro Ciénegas Basin (CCB), Mexico, is an oligotrophic ecosystem with acute P limitation, providing a great opportunity to assess the various strategies that bacteria from soil and sediment use to obtain P. We measured the activities in sediment and soil of different exoenzymes involved in P recycling and evaluated 1,163 bacterial isolates (mainly Bacillus spp.) for their ability to use six different P substrates. DNA turned out to be a preferred substrate, comparable to a more bioavailable P source, potassium phosphate. Phosphodiesterase activity, required for DNA degradation, was observed consistently in the sampled-soil and sediment communities. A capability to use phosphite (PO3 (3-)) and calcium phosphate was observed mainly in sediment isolates. Phosphonates were used at a lower frequency by both soil and sediment isolates, and phosphonatase activity was detected only in soil communities. Our results revealed that soil and sediment bacteria are able to break down and use P forms in different oxidation states and contribute to ecosystem P cycling. Different strategies for P utilization were distributed between and within the different taxonomic lineages analyzed, suggesting a dynamic movement of P utilization traits among bacteria in microbial communities. IMPORTANCE: Phosphorus (P) is an essential element for life found in molecules, such as DNA, cell walls, and in molecules for energy transfer, such as ATP. The Valley of Cuatro Ciénegas, Coahuila (Mexico), is a unique desert characterized by an extreme limitation of P and a great diversity of microbial life. How do bacteria in this valley manage to obtain P? We measured the availability of P and the enzymatic activity associated with P release in soil and sediment. Our results revealed that soil and sediment bacteria can break down and use P forms in different oxidation states and contribute to ecosystem P cycling. Even genetically related bacterial isolates exhibited different preferences for molecules, such as DNA, calcium phosphate, phosphite, and phosphonates, as substrates to obtain P, evidencing a distribution of roles for P utilization and suggesting a dynamic movement of P utilization traits among bacteria in microbial communities.

Volunteer Providers' Experience Referring Guatemalan Patients for Acupuncture Care in a Pilot, Integrated, Health Care Clinic.

Purpose: The aim of this qualitative study was to explore the experience of volunteer providers referring Guatemalan patients for acupuncture care during a 1-day, pilot, integrated, health care clinic. Methods: In a partnership among the University of Utah College of Nursing and Refuge International, the integrated, health care clinic occurred at hospital in San Raymundo. Before the clinic, nursing faculty offered providers an overview of acupuncture care. Providers referred 11 patients for acupuncture care. After the clinic, seven providers (one cardiologist, one certified nurse midwife, five student nurse midwives) were asked 10 questions in semi-structured interviews about their experience referring patients for acupuncture care. The interviews were audiotaped, transcribed, and analyzed to identify themes. Results: Five themes emerged from analysis of the semi-structured interviews. Providers accurately recognized primarily pain, among other reasons, to refer patients for acupuncture care. Providers stated they lacked a comprehensive understanding of acupuncture care and wanted a more thorough education. Providers did not encounter barriers to referring patients for acupuncture care, and referrals did not hinder clinic flow. Providers were enthusiastically receptive to acupuncture care and endorsed expansion of integrated, health care clinics. Providers felt acupuncture care offered an important and culturally acceptable alternative to biomedicine, particularly for Guatemalan patients who are frequently marginalized and lack consistent access to health care. Discussion: Results from this pilot study indicate promising potential for offering acupuncture care in an integrated, health care clinic, particularly for marginalized patients who lack consistent access to health care.

Control of inorganic and organic phosphorus molecules on microbial activity, and the stoichiometry of nutrient cycling in soils in an arid, agricultural ecosystem.

Background: The dynamics of carbon (C), nitrogen (N), and phosphorus (P) in soils determine their fertility and crop growth in agroecosystems. These dynamics depend on microbial metabolism, which in turn depends on nutrient availability. Farmers typically apply either mineral or organic fertilizers to increase the availability of nutrients in soils. Phosphorus, which usually limits plant growth, is one of the most applied nutrients. Our knowledge is limited regarding how different forms of P impact the ability of microbes in soils to produce the enzymes required to release nutrients, such as C, N and P from different substrates. Methods: In this study, we used the arable layer of a calcareous soil obtained from an alfalfa cropland in Cuatro Cienegas, México, to perform an incubation experiment, where five different phosphate molecules were added as treatments substrates: three organic molecules (RNA, adenine monophosphate (AMP) and phytate) and two inorganic molecules (calcium phosphate and ammonium phosphate). Controls did not receive added phosphorus. We measured nutrient dynamics and soil microbial activity after 19 days of incubation. Results: Different P molecules affected potential microbial C mineralization (CO2-C) and enzyme activities, specifically in the organic treatments. P remained immobilized in the microbial biomass (Pmic) regardless of the source of P, suggesting that soil microorganisms were limited by phosphorus. Higher mineralization rates in soil amended with organic P compounds depleted dissolved organic carbon and increased nitrification. The C:N:P stoichiometry of the microbial biomass implied a change in the microbial community which affected the carbon use efficiency (CUE), threshold elemental ratio (TER), and homeostasis. Conclusion: Different organic and inorganic sources of P affect soil microbial community structure and metabolism. This modifies the dynamics of soil C, N and P. These results highlight the importance of considering the composition of organic matter and phosphate compounds used in agriculture since their impact on the microbial activity of the soil can also affect plant productivity.

Higher-order interactions and emergent properties of microbial communities: The power of synthetic ecology.

Humans have long relied on microbial communities to create products, produce energy, and treat waste. The microbiota residing within our bodies directly impacts our health, while the soil and rhizosphere microbiomes influence the productivity of our crops. However, the complexity and diversity of microbial communities make them challenging to study and difficult to develop into applications, as they often exhibit the emergence of unpredictable higher-order phenomena. Synthetic ecology aims at simplifying complexity by constituting synthetic or semi-natural microbial communities with reduced diversity that become easier to study and analyze. This strategy combines methodologies that simplify existing complex systems (top-down approach) or build the system from its constituent components (bottom-up approach). Simplified communities are studied to understand how interactions among populations shape the behavior of the community and to model and predict their response to external stimuli. By harnessing the potential of synthetic microbial communities through a multidisciplinary approach, we can advance knowledge of ecological concepts and address critical public health, agricultural, and environmental issues more effectively.

Flavones isolated from Pseudognaphalium liebmannii with tracheal smooth muscle relaxant properties.

The inflorescences of Pseudognaphalium liebmannii are used as folk medicine to treat various respiratory diseases. In this work, we report the isolation of seven known flavones: 5-hydroxy-3,7-dimethoxyflavone 1, 5,8-dihydroxy-3,7-dimethoxyflavone 2, 5,7-dihydroxy-3,8-dimethoxyflavone 3 (gnaphaliin A), 3,5-dihydroxy-7,8-dimethoxyflavone 4 (gnaphaliin B), 3,5-dihydroxy-6,7,8-trimethoxyflavone 5, 3,5,7-trimethoxyflavone 6 and 3-O-methylquercetin 7. All these flavones except 1 and 6 showed a relaxant effect on guinea pig tracheal preparation with EC50 between 69.91 ± 15.32 and 118.72 ± 7.06 µM. Aminophylline (EC50 = 122.03 ± 7.05 µM) was used as a relaxant reference drug. The active flavones shifted the concentration-response curves of forskolin and nitroprusside leftward, and significantly reduced the EC50 values of these drugs. Furthermore, these flavones dose-dependently inhibited phosphodiesterase (PDE) in an in vitro assay. This reveals that the inflorescences of P. liebmannii contain several flavones with relaxant effect on airway smooth muscle and with PDEs inhibition that contribute to supporting the anti-asthmatic traditional use.

[Implementation of diabetic retinopathy screening using digital retinography in primary care]. / Implantación del cribado de retinopatía diabética mediante retinografía digital en atención primaria.

OBJECTIVE: To improve early detection and monitoring of diabetic retinopathy (DR) in two primary care centers (PCC) using a non-mydriatic retinal camera (NMRC). DESIGN: Prospective longitudinal descriptive study. LOCATION: Area 11 Primary Care, Madrid. PARTICIPANTS: Adult patients with diabetes (DM) without funduscopic examination in the last two years (FO). INTERVENTIONS: Implementation process of screening for DR by NMRC in PCC. Digital photography of the retina made by nursing staff. Interpretation of retinal images by an ophthalmologist. MEASUREMENTS: Number of DM with FO. Number of patients with DR. Metabolic control in the last two years (HbA1c). STUDY PERIOD: September 2009-September 2011. RESULTS: DM increased from 2850 to 3357. The proportion of patients with FO increased from 6.7% (95% CI: 5.7-7.6%) to 32.4% (95% CI: 30.8-34.0%) (P<.001). The prevalence of DR increased from 3.85% (95% CI: 3.14-4.58%) to 4.3% (95% CI: 3.59-4.99%). The percentage of patients with FO and DR decreased from 60% (95% CI: 52.77-67.23%) to 14% (95% CI: 11.87-16.09%) (P<.001). The proportion of DM with HbA1c increased from 21.9% (95% CI: 20.36-23.43%) to 52.4% (95% CI: 50.69-54.10%) (P<.001). The mean HbA1c in patients with DR and without DR was 7.8 (95% CI: 7.50-8.06) and 7.1 (IC95% CI: 7.08-7.22) (P<.001), respectively. CONCLUSIONS: NMRC in PCC is accompanied by an increase in the number of diabetics with FO examination. The implementing of DR screening is possible if an NMRC is available, along with available resources, the motivation of the professionals involved and management commitment. A longer follow-up is required to determine its impact on referral rates to ophthalmology service, and to only refer those with dubious images.

A three-species synthetic community model whose rapid response to antagonism allows the study of higher-order dynamics and emergent properties in minutes.

Microbial communities can be considered complex adaptive systems. Understanding how these systems arise from different components and how the dynamics of microbial interactions allow for species coexistence are fundamental questions in ecology. To address these questions, we built a three-species synthetic community, called BARS (Bacillota A + S + R). Each species in this community exhibits one of three ecological roles: Antagonistic, Sensitive, or Resistant, assigned in the context of a sediment community. We show that the BARS community reproduces features of complex communities and exhibits higher-order interaction (HOI) dynamics. In paired interactions, the majority of the S species (Sutcliffiella horikoshii 20a) population dies within 5 min when paired with the A species (Bacillus pumilus 145). However, an emergent property appears upon adding the third interactor, as antagonism of species A over S is not observed in the presence of the R species (Bacillus cereus 111). For the paired interaction, within the first 5 min, the surviving population of the S species acquires tolerance to species A, and species A ceases antagonism. This qualitative change reflects endogenous dynamics leading to the expression for tolerance to an antagonistic substance. The stability reached in the triple interaction exhibits a nonlinear response, highly sensitive to the density of the R species. In summary, our HOI model allows the study of the assembly dynamics of a three-species community and evaluating the immediate outcome within a 30 min frame. The BARS has features of a complex system where the paired interactions do not predict the community dynamics. The model is amenable to mechanistic dissection and to modeling how the parts integrate to achieve collective properties.

Delivering Acupuncture Therapy in an Interdisciplinary Global Health Setting in Guatemala: Pilot Study and Lessons Learned.

Objective: Pain, stress, and diabetes mellitus (DM) are common complaints for Guatemalans seeking health care. Because acupuncture therapy (AT) is a low-cost, effective treatment for these concerns, it was offered to Guatemalans during a health care mission as an adjunct to primary care. The purpose of this study was to gather feedback about providing AT in this context and to describe the lessons that were learned. Materials and Methods: A pretest single-arm exploratory study design was used, collecting demographic data and administering a pretest to patients referred for AT. Patients received AT according to presenting symptoms, except patients with DM, who were treated with a previously developed auricular AT protocol. After AT, all patients received adhesive seeds for self-administered auricular acupressure, along with a printed diagram, showing where and how to apply them, and a symptom-tracking form. Results: AT was given to 11 patients (1 had DM; 10 did not). Most were female (9; 82%), older (average 59.27 years; range: 40-81 years), and had little education (average 4 years; range: 0-12 years). Complaints were pain (11; 100%), insomnia (6; 55%), anxiety (4; 36%), depression (7; 64%), and stress (3; 27%). More than 50% had seen health care providers (6; 55%). One person had AT previously and 3 people requested more information about AT before receiving it. Conclusions: Reporting high symptom burdens, most patients were unfamiliar with AT. AT ceased when the licensed acupuncturist contracted COVID. Patients will be followed in 2023 and AT will be given to collect data on feasibility, satisfaction, and possible implementation.

Intermunicipal travel networks of Mexico during the COVID-19 pandemic.

Human mobility networks are widely used for diverse studies in geography, sociology, and economics. In these networks, nodes usually represent places or regions and links refer to movement between them. They become essential when studying the spread of a virus, the planning of transit, or society's local and global structures. Therefore, the construction and analysis of human mobility networks are crucial for a vast number of real-life applications. This work presents a collection of networks that describe the human travel patterns between municipalities in Mexico in the 2020-2021 period. Using anonymized mobile location data, we constructed directed, weighted networks representing the volume of travels between municipalities. We analysed changes in global, local, and mesoscale network features. We observe that changes in these features are associated with factors such as COVID-19 restrictions and population size. In general, the implementation of restrictions at the start of the COVID-19 pandemic in early 2020, induced more intense changes in network features than later events, which had a less notable impact in network features. These networks will result very useful for researchers and decision-makers in the areas of transportation, infrastructure planning, epidemic control and network science at large.

A Transiently Hypersaline Microbial Mat Harbors a Diverse and Stable Archaeal Community in the Cuatro Cienegas Basin, Mexico.

Microbial mats are biologically diverse communities that are analogs to some of the earliest ecosystems on Earth. In this study, we describe a unique transiently hypersaline microbial mat uncovered in a shallow pond within the Cuatro Cienegas Basin (CCB) in northern México. The CCB is an endemism-rich site that harbors living stromatolites that have been studied to understand the conditions of the Precambrian Earth. These microbial mats form elastic domes filled with biogenic gas, and the mats have a relatively large and stable subpopulation of archaea. For this reason, this site has been termed archaean domes (AD). The AD microbial community was analyzed by metagenomics over three seasons. The mat exhibited a highly diverse prokaryotic community dominated by bacteria. Bacterial sequences are represented in 37 phyla, mainly Proteobacteria, Firmicutes, and Actinobacteria, that together comprised >50% of the sequences from the mat. Archaea represented up to 5% of the retrieved sequences, with up to 230 different archaeal species that belong to 5 phyla (Euryarchaeota, Crenarchaeota, Thaumarchaeota, Korarchaeota, and Nanoarchaeota). The archaeal taxa showed low variation despite fluctuations in water and nutrient availability. In addition, predicted functions highlight stress responses to extreme conditions present in the AD, including salinity, pH, and water/drought fluctuation. The observed complexity of the AD mat thriving in high pH and fluctuating water and salt conditions within the CCB provides an extant model of great value for evolutionary studies, as well as a suitable analog to the early Earth and Mars.

Comparing the evolutionary dynamics of predominant SARS-CoV-2 virus lineages co-circulating in Mexico.

Over 200 different SARS-CoV-2 lineages have been observed in Mexico by November 2021. To investigate lineage replacement dynamics, we applied a phylodynamic approach and explored the evolutionary trajectories of five dominant lineages that circulated during the first year of local transmission. For most lineages, peaks in sampling frequencies coincided with different epidemiological waves of infection in Mexico. Lineages B.1.1.222 and B.1.1.519 exhibited similar dynamics, constituting clades that likely originated in Mexico and persisted for >12 months. Lineages B.1.1.7, P.1 and B.1.617.2 also displayed similar dynamics, characterized by multiple introduction events leading to a few successful extended local transmission chains that persisted for several months. For the largest B.1.617.2 clades, we further explored viral lineage movements across Mexico. Many clades were located within the south region of the country, suggesting that this area played a key role in the spread of SARS-CoV-2 in Mexico.

Implementing an action protocol on prostatic disease in primary care and impact on referrals to urology.

OBJECTIVES: To determine the impact of implementing a joint action protocol on prostatic disease on the referrals to Urology from Primary Care in a health care area. METHODS: We drafted a protocol for managing patients consulting for clinical signs and symptoms associated to benign prostatic hyperplasia (BPH) and to test PSA in asymptomatic males. At the same time, three e-mail addresses were opened for consultations generated from Primary Care, and joint sessions were carried out in the primary health care centers. We measured the impact of the protocol by assessing the adequacy of prostatic disease referrals to Urology, as well as by determining the course of the total number of referrals in three peripheral specialized health care centers (PSHCC). RESULTS: From January 2011, a better compliance to the referrals to Urology protocol for prostatic disease has been produced, going from 47% (assessment prior to implementing the protocol) to 64%. These results are especially good when we consider referrals associated to PSA, which went from a compliance of 33% to 84%. Regarding the course of the referrals to Urology, the referral rate (referrals per 1000 inhabitants) has decreased by 15% (from 13,8 to 11,7). CONCLUSIONS: The collaboration between Urology and Primary health care, by means of implementing joint protocols, and also by establishing new communication channels (e-mail, joint sessions), achieves a better adequacy of patients referred for prostatic disease, as well as a reduction in the total number of referrals.

Highlights from the 7th Oncological Pathology Conference 'Pathological Anatomy in the context of the National Cancer Law: An overview of the Latin American experience', 15, 22 and 23 July 2022, Trujillo, Peru.

The seventh session of the Oncological Pathology Conference (JoPaO) entitled 'Pathological Anatomy in the context of the National Cancer Law: An overview of the Latin American experience', was held virtually on July 15, 22 and 23. Peru was the headquarters for this event, where 17 national and international professors of high academic standing participated. They interacted in a multidisciplinary context through talks with national panellists and the general public. The recent promulgation of the 'National Cancer Law' fosters the development of discussion forums to analyse the national realities and uphold continuous learning about experiences in other Latin American countries with successful cancer programmes, in which pathology holds a principal role. The topics addressed during this JoPaO included the exchange of Latin American cancer management experiences, an emphasis on investments in and the development of strategic plans to improve care, the use of new technologies, laboratory quality control, and the need to advance scientific research.

Evaluating Pain Management Practices for Cancer Patients among Health Professionals: A Global Survey.

Background: Cancer incidence in the world is predicted to increase in the next decade. While progress has been in diagnosis and treatment, much still remains to be done to improve cancer pain therapy, mainly in underserved communities in low-income countries. Objective: To determine knowledge, beliefs, and barriers regarding pain management in both high- and low-income countries (according to the WHO classification); and to learn about ways to improve the current state of affairs. Design: Descriptive survey. Setting/Subjects: Fifty-six countries worldwide; convenience sample of 1639 consisted of 36.8% physicians; 45.1% nurses, and 4.5% pharmacists employed in varied settings. Results: Improved pain management services are key elements. Top barriers include religion factors, lack of appropriate education and training at all levels, nonadherence to guidelines, patients' reluctance to report on pains, over regulation associated with prescribing and access to opioid analgesics, fear of addiction to opioids, and lack of discussions around prognosis and treatment planning. Conclusion: The majority of patients with cancer in low-income countries are undertreated for their pain. Promoting cancer pain accredited program of training and education on pain management for physicians and nurses is crucial, as well as advocating policymakers and the public at large.

Phylogenetic distribution and evolutionary history of bacterial DEAD-Box proteins.

DEAD-box proteins are found in all domains of life and participate in almost all cellular processes that involve RNA. The presence of DEAD and Helicase_C conserved domains distinguish these proteins. DEAD-box proteins exhibit RNA-dependent ATPase activity in vitro, and several also show RNA helicase activity. In this study, we analyzed the distribution and architecture of DEAD-box proteins among bacterial genomes to gain insight into the evolutionary pathways that have shaped their history. We identified 1,848 unique DEAD-box proteins from 563 bacterial genomes. Bacterial genomes can possess a single copy DEAD-box gene, or up to 12 copies of the gene, such as in Shewanella. The alignment of 1,208 sequences allowed us to perform a robust analysis of the hallmark motifs of DEAD-box proteins and determine the residues that occur at high frequency, some of which were previously overlooked. Bacterial DEAD-box proteins do not generally contain a conserved C-terminal domain, with the exception of some members that possess a DbpA RNA-binding domain (RBD). Phylogenetic analysis showed a separation of DbpA-RBD-containing and DbpA-RBD-lacking sequences and revealed a group of DEAD-box protein genes that expanded mainly in the Proteobacteria. Analysis of DEAD-box proteins from Firmicutes and γ-Proteobacteria, was used to deduce orthologous relationships of the well-studied DEAD-box proteins from Escherichia coli and Bacillus subtilis. These analyses suggest that DbpA-RBD is an ancestral domain that most likely emerged as a specialized domain of the RNA-dependent ATPases. Moreover, these data revealed numerous events of gene family expansion and reduction following speciation.

Development and validation of a column high-performance liquid chromatography method for quantification of ganaphaliin A and B in inflorescences of Gnaphalium liebmannii Sch. Bp ex Klatt.

An HPLC method was developed for the simultaneous determination of gnaphaliin A and B, active compounds of Gnaphalium liebmannii Sch. Bp ex Klatt. The HPLC separation was performed on an Inertsil ODS-3 (150 x 4.6 mm id, 5 microm) RP C18 column operated at 40 degrees C; the isocratic mobile phase was 0.02% aqueous orthophosphoric acid-methanol-acetonitrile (50 + 30 + 20, v/v/v), with a run time of 20 min and flow rate of 1.5 mL/min. Detection with a photodiode array detector (PDAD) was at 270 nm. The method was validated for linearity, repeatability, LOD, and LOQ. The LOD and LOQ for gnaphaliin A and B were found to be in the range of 0.4-0.5 and 1.0-1.4 microg/mL, respectively. This is the first report of an analytical method developed for the quantitative analysis of flavones from Gnaphalium species by HPLC-PDAD with applications for raw material and commercial products.