Regeneration of the caudal fin of the evolutionary ancient tropical gar Atractosteus tropicus.

BACKGROUND: The tropical gar (Atractosteus tropicus), a member of the Lepisosteidae family, is native to regions extending from southeastern Mexico to southern Costa Rica. This species serves as a unique bridge between tetrapods and teleosts due to its phylogenetic position, slow evolutionary rate, dense genetic map, gene similarities with humans, and ease of laboratory cultivation. As a taxonomic sister group to teleosts like the zebrafish (Danio rerio), known for its high regenerative capacity, it remains unclear whether the tropical gar shares a similar ability for regeneration. RESULTS: This study aims to elucidate the caudal fin regeneration process in tropical gar through skeletal and histological staining methods. Juvenile specimens were observed over a two-month period, during which they were fed brine shrimp, and anesthetized with 1% eugenol for caudal fin amputation. Samples were collected at various days post-amputation (dpa). Alcian blue and alizarin red staining were used to highlight skeletal regeneration, particularly the formation of new cartilage, while histological staining with hematoxylin and eosin was performed to observe tissue regeneration at the amputation site. CONCLUSIONS: The findings reveal a remarkable ability for caudal fin regeneration in juvenile tropical gar. Given the Garfish evolutionary relationship with teleosts, this opens new avenues for research into tissue regeneration across different groups of Actinopterygii.

REDESCRIPTION OF HASSALSTRONGYLUS ADUNCUS CHANDLER, 1932 (NEMATODA: HELIGMONELLIDAE), WITH THE DESCRIPTION OF A NEW SPECIES OF THE GENUS AND THEIR PHYLOGENETIC POSITION WITH OTHER HELIGMOSOMOIDEA TRAVASSOS, 1914.

ABSTRACT: Hassalstrongylus Durette-Desset, 1971 (Nematoda: Heligmonellidae), includes 19 species that are distributed from the southwestern United States to central-western Argentina. Hassalstrongylus aduncus is a parasitic nematode of rodents from the subfamilies Arvicolinae, Murinae, and Sigmodontinae, and has been recorded from southern Virginia and Oklahoma to Costa Rica. This species was described by Chandler in 1932; the morphology of the synlophe was not included. Subsequently, in 1972, Durette-Desset described only the synlophe of the middle region of the body in both sexes. Despite its wide geographical distribution, to date, there has been no redescription that includes information complementary to the morphology of the synlophe, such as a study of the body surface or a molecular phylogenetic analysis. We reevaluated the morphology of some specimens that were presumably similar to H. aduncus parasite of Sigmodon sp. from Jalisco, Mexico, and it was determined that these corresponded to an undescribed species of the genus. Herein, we present a redescription of H. aduncus parasite of Sigmodon toltecus from Hidalgo, Mexico, with morphological traits such as the excretory pore, deirids, and ovijector, and provide a description of the synlophe in the anterior and posterior regions of both sexes and include scanning electron microscopy images. Hassalstrongylus geolayarum n. sp. is differentiated from H. aduncus by the number of ridges in the middle region of the body (23 vs. 21), as well as proportions between some traits of males and females such as total length/spicule length, total length/gubernaculum length, total length/length of the esophagus and total length/distance of the vulva and the size of the eggs (42 vs. 58 µm). Phylogenetic analysis is based on partial sequences of the nuclear ribosomal internal transcribed spacer region (ITS1 + 5.8S + ITS2) of the rDNA, using the maximum-parsimony, maximum-likelihood, and Bayesian inference methods revealed the close relationship of H. aduncus + H. geolayarum n. sp. within the Heligmosomoidea and confirmed the placement of the Hassalstrongylus monophyletic clade well-supported within Heligmonellidae. The new species presented a genetic divergence of 3.4-3.8% relative to H. aduncus. This is the first species of the genus described in Mexico. Presumably, there are more species not yet described throughout the geographic range of H. aduncus. A taxonomic review and molecular phylogenetic analysis are required in which more species and genes are analyzed in Heligmosomoidea to confirm the status of the nonmonophyletic groups recovered here.

County-Level Structural Vulnerabilities in Maternal Health and Geographic Variation in Infant Mortality.

OBJECTIVE: To evaluate whether community factors that differentially affect the health of pregnant people contribute to geographic differences in infant mortality across the US. STUDY DESIGN: This retrospective cohort study sought to characterize the association of a novel composite measure of county-level maternal structural vulnerabilities, the Maternal Vulnerability Index (MVI), with risk of infant death. We evaluated 11 456 232 singleton infants born at 22 0 of 7 through 44 6 of 7 weeks' gestation from 2012 to 2014. Using county-level MVI, which ranges from 0 to 100, multivariable mixed effects logistic regression models quantified associations per 20-point increment in MVI, with odds of death clustered at the county level and adjusted for state, maternal, and infant covariates. Secondary analyses stratified by the social, physical, and health exposures that comprise the overall MVI score. Outcome was also stratified by cause of death. RESULTS: Rates of death were higher among infants from counties with the greatest maternal vulnerability (0.62% in highest quintile vs 0.32% in lowest quintile, [P < .001]). Odds of death increased 6% per 20-point increment in MVI (aOR: 1.06, 95% CI 1.04, 1.07). The effect estimate was highest with theme of Mental Health and Substance Abse (aOR 1.08; 95% CI 1.06, 1.09). Increasing vulnerability was associated with 6 of 7 causes of death. CONCLUSIONS: Community-level social, physical, and healthcare determinants indicative of maternal vulnerability may explain some of the geographic variation in infant death, regardless of cause of death. Interventions targeted to county-specific maternal vulnerabilities may reduce infant mortality.

A NEW SPECIES OF CHIGGER MITE AND THE RECORD OF A GASTROINTESTINAL NEMATODE IN SCELOPORUS CAUTUS (SQUAMATA: PHRYNOSOMATIDAE) FROM THE CHIHUAHUAN DESERT PROVINCE IN COAHUILA, MEXICO.

The chigger species Acomatacarus coahuilensis n. sp. (Acariformes: Trombidiformes: Leeuwenhoekiidae) inhabiting the neck scales of the wary spiny lizard Sceloporus cautus Smith, 1938 (Squamata: Iguania: Phrynosomatidae), from Chihuahuan Desert Province, Coahuila, Mexico, is described herein. The new mite species is assigned to the genus AcomatacarusEwing, 1942, based on a palptarsus with 6 branched setae plus the tarsala (ω). This new species can be separated from the other species in this genus mainly based on the combination of the following characters: presence of mastisetae (MTa) on tarsus III and tibiala (φ) on tibia III, subterminala (ζ1), parasubterminala (z), and pretarsala (ζ2) on tarsus I, 2 genualae (σ1-2) on genu I, onychotriches and claw-like empodium of legs I-III, and absence of mastisetae on tibia III. In addition to the new species, the gastrointestinal nematode Skrjabinoptera phrynosoma (Ortlepp, 1922) Schulz, 1927 (Physalopteridae), was also found, which represents a new host record in the wary spiny lizard. This study reports the third species of the genus Acomatacarus recorded from Mexico and the first record of chigger mites and helminth parasites associated with Sc. cautus.

Gait speed as a predictor of mortality in older men with cancer: A longitudinal study in Peru.

BACKGROUND: Given the increase in incidence and mortality from cancer in recent years in Latin America and Peru, it is necessary to identify frailty older adults at higher risk of disability, hospitalizations and mortality. However, its measure is complex and requires time. For this reason, it has been proposed that frailty can be evaluated by a single measure, as gait speed. We aimed to evaluate the role of gait speed as a predictor of mortality in older men with cancer in Peru. METHODS: A prospective cohort study was carried out that included military veterans (aged 60 years and older) with an oncological diagnosis evaluated at the Centro Médico Naval in Peru during the period 2013-2015. Slow gait speed was defined as <0.8 m/s. All-cause mortality was recorded during a 2-year follow-up. Sociodemographic characteristics, medical and personal history, and functional assessment measures were collected. We performed Cox regression analysis to calculate hazard ratios with their respective 95% confidence intervals. RESULTS: 922 older men were analyzed from 2013 to 2015, 56.9% (n = 525) of whom were >70 years of age. 41.3% (n = 381) had slow gait speed with a mortality incidence of 22.9% (n = 211) at the end of follow-up. The most frequent types of cancer in the participants who died were of the lung and airways (26.1%), liver and bile ducts (23.2%), and lymphomas and leukemias (16.6%). In the adjusted Cox regression analysis, we found that slow gait speed was a risk factor for mortality in older men with cancer (adjusted hazard ratio = 1.55; 95% confidence interval: 1.21-2.23). CONCLUSIONS: Slow gait speed was associated with an increased risk of mortality in older men with cancer. Gait speed could represent a simple, useful, inexpensive, rapidly applicable marker of frailty for the identification of older men at higher risk of mortality. Gait speed could be useful in low- and middle-income countries, and in rural areas with limited access to health services.

A Resident-driven Initiative to Increase Bedside Teaching on Interdisciplinary Rounds.

Inpatient rounding serves numerous roles. The American Academy of Pediatrics recommends a family-centered bedside model. Residents identified physical examination teaching during and satisfaction with rounds as areas for improvement. A resident group developed a project utilizing quality improvement (QI) methodology to address these concerns. We aimed to increase the frequency of bedside physical examination teaching most or every day on a single inpatient unit by 20% over 1 year, with secondary goals to increase the percentage of interns spending one hour or more at bedside per day by 10% and intern satisfaction by 15%, without impacting rounding duration. METHODS: We developed an organizational structure to complete a long-term resident-led project. Interventions included daily bedside examination teaching on rounds, afternoon examinations, goal communication, topic recording, and a teaching "tip sheet." Using an institutional QI framework, we utilized iterative plan-do-study-act cycles to implement interventions and surveys to assess outcomes, with rounding efficiency as a balancing measure. RESULTS: The survey response rate was 57%. Bedside teaching frequency increased from a mean of 10% to 61%, perceived time at the bedside increased from 37% to 59%, and rounding satisfaction improved from a rating of 6.7/10 to 7.4/10. Efficiency was not impacted. CONCLUSIONS: We improved inpatient rounds bedside physical examination teaching and satisfaction without sacrificing efficiency. This project demonstrates the feasibility and success of a resident-driven education initiative to successfully motivate fellow residents and colleagues across disciplines to enact change. The organizational structure may serve as a model for resident-led QI projects across institutions.

Antibiotic resistance of Salmonella strains from layer poultry farms in central Ecuador.

AIMS: This study evaluated the antimicrobial resistance of Salmonella enterica strains from layer poultry farms in central Ecuador isolated during 2017. This geographical area is responsible for around 60% of total domestic egg production, yet, as of 2019, no reports had been published on the phenotypic and genotypic antibiotic resistance patterns of Salmonella in the layer poultry farms of this area. METHODS AND RESULTS: Thirty-one isolates from layer poultry farms in central Ecuador obtained during 2017 were evaluated. The resistance profiles exhibited considerable differences in serovar and sample origin, grouping into nine clades by phenotype. S. Infantis strains were of the MDR phenotype in 94·4% of isolates. S. Typhimurium strains were of a reduced antimicrobial resistance phenotype and 50% showed resistance to one antimicrobial compound. One of the S. enterica nontyped strains had an MDR profile to 11 of the 20 antibiotics evaluated (eight groups). And the two remaining S. enterica nontyped strains showed resistance to two and three antibiotics respectively. The ESBL phenotype, which is resistant to clinically notable antibiotics such as ceftriaxone, ampicillin and cefepime, was observed only in S. Infantis (15/18). These strains harbour the emerging blaCTX-M-65 gene, and co-harbour tetA and sul1 resistance genes in four strains. Additional ß-lactamase genes, carbapenemase-producing genes (blaIMP, blaVIM , blaOXA48 , blaKPC , blaNDM ) and colistin-mobile resistance gene mcr-1 were not detected. CONCLUSIONS: The findings highlight the potential role of layer poultry farm environments in central Ecuador as reservoirs of MDR Salmonella strains. SIGNIFICANCE AND IMPACT OF THE STUDY: These results suggest the necessity of reinforcing biosecurity practices to reduce the probability of transmission of MDR Salmonella across the food chain.

Identification of leopard frogs (Anura: Ranidae: Lithobates) distributed in some localities of the Southern Mexican Plateau using mitochondrial DNA sequences.

Species of the genus Lithobates are difficult to identify, especially on the 'Rana pipiens' complex, because the morphological differences among the species are often subtle. In this study, we used 12S ribosomal RNA gene partial sequences to identify specimens of leopard frogs from some new localities (not sampled on previous studies) of the Southern Mexican Plateau, to carry out a phylogenetic analysis, and also a morphometric analysis of some morphological features were analyzed to evaluate their morphological variation. A phylogenetic analysis using partial sequences of 12S rDNA mitochondrial gene for 31 samples was carried out using Bayesian Inference, Maximum Parsimony, and Maximum Likelihood. In addition, 20 morphological lineal measurements from 97 specimens were analyzed by principal component analysis (PCA) to evaluate if the frogs studied are conspecific. Partial sequences of the 12S rDNA obtained from frogs distributed in the Southern Mexican Plateau show two haplotypes with a divergence of 0.4%. Phylogenetic hypothesis shows an exclusive group with a previous sequence of Lithobates montezumae. The PCA indicates that variables are not linearly correlated and specimens belong to a single group. Evidence found, let us consider that specimens studied belong to one species of the Lithobates montezumae subgroup, distributed principally in the Southern Mexican Plateau.

A New Species of Morelacarus (Acariformes: Prostigmata: Leeuwenhoekiidae) Associated With Sceloporus grammicus (Squamata: Phrynosomatidae) From the Mexican Plateau, Zacatecas, Mexico.

A new species of chigger mites, Morelacarus uazi n. sp., parasitizing lizards of the species Sceloporus grammicus from Mazapil, Zacatecas, Mexico, is described and illustrated. This new taxon differs from other species of the genus by having a palpal claw with 4 subequal paired prongs, and it can be further distinguished by the combination of the following characters: presence of onychotriches and mastitarsala III, absence of mastitibiala III, subterminala I, and parasubterminala I, and the palpal setal formula B/B/BBb. Additionally, an identification key for the species of the genus Morelacarus is presented. The new species represents the seventh species assigned to the genus and the first species described from a Mexican lizard.

Mexican Propolis: A Source of Antioxidants and Anti-Inflammatory Compounds, and Isolation of a Novel Chalcone and ε-Caprolactone Derivative.

The propolis produced by bees are used in alternative medicine for treating inflammation, and infections, presumably due to its antioxidant properties. In this context, five propolis from México were investigated to determine their inhibitory lipid peroxidation properties. The ethyl acetate extract from a red propolis from Chiapas State (4-EAEP) was the most potent (IC50 = 1.42 ± 0.07 µg/mL) in the TBARS assay, and selected for further studies. This extract afforded two new compounds, epoxypinocembrin chalcone (6), and an ε-caprolactone derivative (10), as well as pinostrobin (1), izalpinin (2), cinnamic acid (3), pinocembrin (4), kaempherol (5), 3,3-dimethylallyl caffeate in mixture with isopent-3-enyl caffeate (7a + 7b), 3,4-dimethoxycinnamic acid (8), rhamnetin (9) and caffeic acid (11). The HPLC profile, anti-mycobacterial, and antioxidant properties of this extract was also determined. Most of the isolated compounds were also tested by inhibition of reactive oxygen species (ROS) in challenged mouse bone marrow-derived mast cells (BMMCs), and DPPH. Their anti-inflammatory activity was evaluated by TPA, and MPO (myeloperoxidase) activity by ear edema test in mice. The most potent compounds were 7a + 7b in the TBARS assay (IC50 = 0.49 ± 0.06 µM), and 2 which restored the ROS baseline (3.5 µM). Our results indicate that 4-EAEP has anti-oxidant, and anti-inflammatory properties due to its active compounds, suggesting it has anti-allergy and anti-asthma potential.

Cholinergic signaling plasticity maintains viscerosensory responses during Aspiculuris tetraptera infection in mice small intestine.

Intestinal parasites alter gastrointestinal (GI) functions like the cholinergic function. Aspiculuris tetraptera is a pinworm frequently observed in laboratory facilities, which infests the mice cecum and proximal colon. However, little is known about the impact of this infection on the GI sensitivity. Here, we investigated possible changes in spontaneous mesenteric nerve activity and on the mechanosensitivity function of worm-free regions of naturally infected mice with A. tetraptera. Infection increased the basal firing of mesenteric afferent nerves in jejunum. Our findings indicate that nicotinic but not muscarinic receptors, similarly affect spontaneous nerve firing in control and infected animals; these axons are mainly vagal. No difference between groups was observed on spontaneous activity after nicotinic receptor inhibition. However, and contrary to the control group, during infection, the muscarinic signaling was shown to be elevated during mechanosensory experiments. In conclusion, we showed for the first time that alterations induced by infection of the basal afferent activity were independent of the cholinergic function but changes in mechanosensitivity were mediated by muscarinic, but not nicotinic, receptors and specifically by high threshold nerve fibers (activated above 20mmHg), known to play a role in nociception. These plastic changes within the muscarinic signaling would function as a compensatory mechanism to maintain a full mechanosensory response and the excitability of nociceptors during infection. These changes indicate that pinworm colonic infection can target other tissues away from the colon.

Molecular Phylogenetic Analysis of Infidum similis, Including Morphological Data and Estimation of its Genome Size.

: Infidum similis Travassos, 1916 (Dicrocoeliidae: Leipertrematinae) was found in the gall bladder of Leptophis diplotropis Günther, 1872 from El Podrido, Acapulco, Guerrero, Mexico. A phylogenetic analysis based on partial sequences of the 28S ribosomal RNA using maximum likelihood (ML) and Bayesian inference (BI) analyses was carried out to assess its phylogenetic position within suborder Xiphidiata, alongside members of the superfamilies Gorgoderoidea and Plagiorchoidea. The phylogenetic trees showed that the genus is most-closely related to the Plagiorchoidea rather than to the Gorgoderoidea, in keeping with previous taxonomic designations. Phylogenies obtained from ML and BI analysis of the 28S rDNA gene revealed a well supported clade in which Choledocystus hepaticus (Lutz, 1928) Sullivan, 1977 is sister to I. similis. On the other hand, a tree obtained using a partial sequence of the cytochrome c oxidase subunit 1 (cox1) mtDNA gene (ML and BI analysis), with species supposed to be closely related to I. similis according to 28S, does not support this relatedness. Based on the independence of Infidum from the subfamily Leipertrematinae Yamaguti, 1958 , our results clearly demonstrated that the genus corresponds to a different family and with species closely related to C. hepaticus within Plagiorchoidea. New data are presented about the tegumental surface of I. similis by scanning electron microscopy as well as the estimation of its haploid genome size using Feulgen Image Analysis Densitometry of sperm nuclei as part of the characterization of this species. This is the first genome size estimated for a member of Plagiorchiida, and these data will provide a new source of knowledge on helminth diversity and evolutionary studies. This constitutes the first host record, and new geographical distribution, for this species in Mexico.

Helminth parasites of Pseudacris hypochondriaca (Anura: Hylidae) from Baja California, Mexico, with the description of two new species of nematodes.

The helminth parasite fauna of the hylid frog Pseudacris hypochondriaca in several localities along the Baja California Peninsula in northwestern Mexico is presented. The helminth fauna consists of 4 species of nematodes (Oswaldocruzia pipiens, a larval form of an Ascaridid, 2 new species belonging to the genera Rhabdias and Cosmocercoides), and 1 species of digenean ( Gorgoderina sp.). The new species of Rhabdias represents the 88th species assigned to the genus and the third species described from Mexican anurans. Also, the species of Cosmocercoides represents the 20th species assigned to the genus and the first representative of this genus described from Mexico.

Molecular evidence that Langeronia macrocirra and Langeronia cf. parva (Trematoda: Pleurogenidae) parasites of anurans from Mexico are conspecific.

The genus Langeronia parasitizing the intestine of several species of anurans is distributed from North to Central America. We identified Langeronia macrocirra and Langeronia cf. parva from the same host and localities, and present here new data not applicable about their tegumental surface by scanning electron microscopy. We compared sequences of the rDNA ITS2 region and mtDNA cox1 gene for the two morphotypes. ITS2 exhibited a high degree of conservation. Phylogenetic reconstruction using cox1 revealed three clades (I, II, and III), which did not correspond to a previous identification or host. Little divergence was found within clades: sequences were identical in clade I, whereas clade II had 0.27% and clade III had 1.08%. Inter-clade divergence reached 8.69% (I vs. III). This pattern of genetic divergence indicated that both taxa probably belong to the same species, so we posit that the morphological changes could be correlated with development. Increasing sample size and geographical coverage will contribute to the taxonomy of the genus based on morphological and molecular evidence, and will open tracks toward the use of DNA barcodes to the genus in Mexico.

Molecular identification of the advanced third-stage larvae (ADV L(3)) of Gnathostoma lamothei in Tabasco, Mexico.

Advanced third-stage larvae (ADV L(3)) of Gnathostoma spp. were collected from the muscle tissue of three species of freshwater fish (i.e., Gobiomorus dormitor, Petenia splendida, and Parachromis managuensis) in Swamps of Centla, Tabasco, Mexico. Nine sequences of the ITS2 of the ribosomal DNA of Gnathostoma spp. were compared with sequences obtained from GenBank for G. binucleatum, G. lamothei, G. miyazakii, G. spinigerum, and G. turgidum. Sequences of the ADV L(3) from P. splendida (Isla Chinal), P. managuensis (Isla Chinal), and of two of the six larvae collected from G. dormitor (Tres Brazos), were identical to that of G. binucleatum (GenBank). Sequences from the other four larvae from G. dormitor (Tres Brazos) are identical to the sequence of G. lamothei (GenBank). This is the first record of the intermediate host of G. lamothei. The only species documented to cause human gnathostomiasis in the Americas is G. binucleatum. Our finding of G. binucleatum, and G. lamothei parasitizing the commercially important fish species, G. dormitor in Centla swamps, indicates the possibility of G. lamothei causing human gnathostomiasis in Mexico as well.

Efectividad del uso de alcohol glicerinado para la descontaminación de manos en una población sin acceso al agua potable posterremoto en Pisco, Perú / Effectiveness of glycerinated alcohol use for decontaminating hands in a population without access to safe water post earthquake in Pisco, Perú

Se evaluó la efectividad del uso de alcohol glicerinado en la desinfección de manos, de personas que preparaban los alimentos en ollas comunes para damnificados de albergues y comités vecinales sin acceso al agua potable, en los primeros días posteriores al terremoto de Pisco. Se realizó un preexperimento con 20 mujeres adultas que no se habían lavado las manos, se cuantificó la carga bacterianade aerobios mesófilos, enterobacterias y Staphylococcus aureus en sus manos antes y después de la aplicación de alcohol glicerinado, usando la prueba de Wilcoxon se encontró una reducción significativa (p menor que 0,001) de la carga bacteriana. En conclusión, la aplicación de alcohol glicerinado es efectiva para la desinfección de manos en manipuladores de alimentos en una población sin acceso al agua yposterremoto.

We assessed the effectiveness of the use of glycerinated alcohol for disinfecting the hands of persons fixing foods in communal kitchens in refugee and neighborhood camps with no access to potable water during the first days alter the earthquake that hit Pisco, Peru in August 2007. A previous assessment was performed in 20 adult women with no prior handwashing. Bacterial load in their hands, including mesophilic microorganisms, Enterobacteriaceae, and Staphylococcus aureus was measured before and after the use of glycerinated alcohol. A significant reduction in bacterial load (p minor that 0.001) was found according to the Wilcoxon test. We conclude that the use of glycerinated alcohol is effective for hand disinfection in people manipulating food in an area with no access to potable water alter a naturaldisaster, in this case, the earthquake that hit Pisco in August 2007.

New species of Rhabdias (Nematoda: Rhabdiasidae) from Bufo occidentalis (Anura: Bufonidae) from Sierra Madre del Sur, Mexico.

Rhabdias kuzmini n. sp., a parasite of the lungs of Bufo occidentalis, is described and illustrated. This Mexican taxon differs from the related species in the genus by the possession of 4 lips (2 subdorsal and 2 subventral) and 2 lateral pseudolabia, corpus not inflated, a larger barrel-shaped buccal capsule, equatorial vulva, and the presence of a slightly swollen cuticle in the anterior and posterior ends of the body. This is the 16th species described in the Neotropical Realm and the first species of Rhabdias described from endemic anurans in México.

A new rhabdiasid species from Norops megapholidotus (Sauria: Polychrotidae) from Mexico.

Rhabdias leonae n. sp., a parasite of the lungs of Norops megapholidotus, is described and illustrated. The Mexican taxon differs from the other species in the genus by a combination of characters: possession of 4 lips, corpus slightly inflated, slightly postequatorial vulva, and presence of swollen cuticle of anterior and posterior ends. This is the 12th species described in the Neotropical realm and the first species of Rhabdias described from an endemic Mexican lizard.

Confirmation of Gnathostoma binucleatum Almeyda-Artigas, 1991, advanced third-stage larvae in Tres Palos Lagoon, Mexico, by morphological and molecular data.

Advanced third-stage larvae of Gnathostoma sp. corresponding to 6 morphotypes, distinguished on the basis of the shape of the cephalic hooklets, were collected from the muscle tissue of 5 species of freshwater fish (i.e., Dormitator latifrons, Eleotris picta, Gobiomorus maculatus, Ariopsis guatemalensis, and Cichlasoma trimaculatum) in Tres Palos Lagoon, Guerrero, Mexico. Principal components analysis of 4 morphological characters cluster all samples in a single taxonomic group. A minimum amount of variation was observed among ITS2 sequences of 3 morphotypes and Gnathostoma binucleatum obtained from GenBank (0-0.84%). The observed variation among morphotypes 1, 2, and 3 is the result of intraspecific variability of G. binucleatum supported by morphology and DNA. Morphotypes 4, 5, and 6 belong to the same taxon on the basis of morphology of the hooklets only. For an accurate morphological diagnosis of the causative agent of gnathostomiasis, it is necessary to develop similar studies with other species of the genus.

Morbilidad y mortalidad en el servicio de hospitalización del Departamento de enfermedades infecciosas, tropicales y dermatológicas del Hospital Nacional Cayetano Heredia entre 1990-2000 / Morbidity and mortality at the inpatient unit of the Tropical Medicine, infectious diseases and dermatology Department at the Hospital Nacional Cayetano Heredia between 1990-2000

Objetivo: Describir la demografía, e identificar la morbilidad más frecuente y las tasas de mortalidad de la unidad de enfermedades infecciosas en un hospital de referencia, público y docente, localizado en el norte de Lima-Perú. Material y métodos: Se realizó un estudio retrospectivo donde se incluyeron todas las hospitalizaciones del Departamento de Enfermedades Infecciosas, Tropicales y Dermatológicas del Hospital Nacional Cayetano Heredia, entre enero de 1990 y diciembre del 2000. Se registraron los datos demográficos, las fechas de ingreso y de alta, todos los diagnósticos, y la condición al alta. Los diagnósticos fueron codificados según la Novena Revisión de la Clasificación Internacional de Enfermedades (CIE-9). Resultados: De 7192 hospitalizaciones registradas, 4603 (64 por ciento) fueron de pacientes varones, la edad media fue 39.2 más menos 19 años. Las hospitalizaciones prácticamente se duplicaron (de 440 a 817) durante el periodo en estudio. La edad media aumentó de 36.6 más menos 16.1 años a 41 más menos 19.9 años, las hospitalizaciones de pacientes geriátricos aumentó de 11.8 por ciento a 21.3 por ciento, y la relación VIH/ no VIH aumentó de 0.07 a 0.25. El índice de rotación de cama aumentó de 12.2 a 22.7. Los diagnósticos más frecuentes fueron: VIH 1209 (10.2 por ciento), tuberculosis 1201 (10.1 por ciento), celulitis 653 (5.5 por ciento). La mortalidad hospitalaria durante el estudio fue de 8.1 por ciento, manteniéndose en promedio constante. Conclusiones: Se observó un aumento en el número de hospitalizaciones, especialmente debido a pacientes geriátricos, sin encontrarse cambios en las tasas de mortalidad. Tuberculosis y VIH fueron los diagnósticos más frecuentes en este estudio.