RESUMEN
INTRODUCTION: Despite the growing use of temporary mechanical circulatory support (tMCS), little data exists to inform management and weaning of these devices. METHODS: We performed an online survey among cardiac intensive care unit directors in North America to examine current practices in the management of patients treated with intraaortic balloon pump and Impella. RESULTS: We received responses from 84% of surveyed centers (n=37). Our survey focused on three key aspects of daily management: 1. Hemodynamic monitoring; 2. Hemocompatibility; and 3. Weaning and removal. We found substantial variability surrounding all three areas of care. CONCLUSION: Our findings highlight the need for consensus around practices associated with improved outcomes in patients treated with tMCS.
Asunto(s)
Corazón Auxiliar , Contrapulsador Intraaórtico , Humanos , América del Norte , Encuestas y Cuestionarios , Contrapulsador Intraaórtico/métodos , Contrapulsador Intraaórtico/estadística & datos numéricos , Remoción de Dispositivos/métodos , Remoción de Dispositivos/estadística & datos numéricos , Monitorización Hemodinámica/métodos , Insuficiencia Cardíaca/terapiaRESUMEN
BACKGROUND: Cow's milk allergy (CMA) overdiagnosis in young children appears to be increasing and has not been well characterised. We used a clinical trial population to characterise CMA overdiagnosis and identify individual-level and primary care practice-level risk factors. METHODS: We analysed data from 1394 children born in England in 2014-2016 (BEEP trial, ISRCTN21528841). Participants underwent formal CMA diagnosis at ≤2 years. CMA overdiagnosis was defined in three separate ways: parent-reported milk reaction; primary care record of milk hypersensitivity symptoms; and primary care record of low-allergy formula prescription. RESULTS: CMA was formally diagnosed in 19 (1.4%) participants. CMA overdiagnosis was common: 16.1% had parent-reported cow's milk hypersensitivity, 11.3% primary care recorded milk hypersensitivity and 8.7% had low-allergy formula prescription. Symptoms attributed to cow's milk hypersensitivity in participants without CMA were commonly gastrointestinal and reported from a median age of 49 days. Low-allergy formula prescriptions in participants without CMA lasted a median of 10 months (interquartile range 1, 16); the estimated volume consumed was a median of 272 litres (26, 448). Risk factors for CMA overdiagnosis were high practice-based low-allergy formula prescribing in the previous year and maternal report of antibiotic prescription during pregnancy. Exclusive formula feeding from birth was associated with increased low-allergy formula prescription. There was no evidence that practice prescribing of paediatric adrenaline auto-injectors or anti-reflux medications, or maternal features such as anxiety, age, parity and socioeconomic status were associated with CMA overdiagnosis. CONCLUSION: CMA overdiagnosis is common in early infancy. Risk factors include high primary care practice-based low-allergy formula prescribing and maternal report of antibiotic prescription during pregnancy.
RESUMEN
Systems of the body develop in a modular manner. For example, neural development in primates is generally rapid, whereas dental development varies much more. In the present study, we examined development of the skull, teeth, and postcrania in a highly specialized leaping primate, Galago moholi. Eighteen specimens ranging from birth to adult were studied. Bones, teeth, and the cranial cavity (i.e., endocast) were reconstructed with Amira software based on microCT cross-referenced to histology. Amira was also used to compute endocast volume (as a proxy for brain size). Reconstructions of the wrist and ankle show that ossification is complete at 1 month postnatally, consistent with the onset of leaping locomotion in this species. Endocranial volume is less than 50% of adult volume at birth, ~80% by 1 month, and has reached adult volume by 2 months postnatal age. Full deciduous dentition eruption occurs by 2 weeks, and the young are known to begin capturing and consuming arthropods on their own by 4 weeks, contemporaneous with the timing of bone and ankle ossification that accompanies successful hunting. The modular pattern of development of body systems in Galago moholi provides an interesting view of a "race" to adult morphology for some joints that are critical for specialized leaping and clinging, rapid crown mineralization to begin a transitional diet, but perhaps more prolonged reliance on nursing to support brain growth.
RESUMEN
OBJECTIVES: We sought to study the association of renal impairment (RI) with mortality in ST-segment elevation myocardial infarction (STEMI) complicated by cardiogenic shock and/or cardiac arrest (CS/CA). METHODS: Patients with RI (estimated glomerular filtration rate <60 mL/min/1.73 m2 ) were identified from the Midwest STEMI consortium, a prospective registry of four large regional programs comprising consecutive patients over 17 years. Primary outcome was in-hospital and 1-year mortality stratified by RI status and presence of CS/CA among patients with STEMI referred for coronary angiography. RESULTS: In a cohort of 13,463 STEMI patients, 13% (n = 1754) had CS/CA, 30% (n = 4085) had RI. Overall, in-hospital mortality was 5% (12% RI vs. 2% no-RI, p < 0.001) and 1-year mortality 9% (21% RI vs. 4% no-RI, p < 0.001). Among uncomplicated STEMI, in-hospital mortality was 2% (4% RI vs. 1% no-RI, p < 0.001) and 1-year mortality 6% (13% RI vs. 3% no-RI, p < 0.001). In STEMI with CS/CA, in-hospital mortality was 29% (43% RI vs. 15% no-RI, p < 0.001) and 1-year mortality 33% (50% RI vs. 16% no-RI, p < 0.001). Using Cox proportional hazards, RI was an independent predictor of in-hospital mortality in STEMI with CS/CA (odds ratio [OR]: 3.86; confidence interval [CI]: 2.6, 5.8). CONCLUSIONS: The association of RI with in-hospital and 1-year mortality is disproportionately greater in those with CS/CA compared to uncomplicated STEMI presentations. Factors predisposing RI patients to higher risk STEMI presentations and pathways to promote earlier recognition in the chain of survival need further investigation.
Asunto(s)
Paro Cardíaco , Intervención Coronaria Percutánea , Infarto del Miocardio con Elevación del ST , Humanos , Choque Cardiogénico/diagnóstico , Choque Cardiogénico/etiología , Infarto del Miocardio con Elevación del ST/diagnóstico por imagen , Infarto del Miocardio con Elevación del ST/terapia , Factores de Riesgo , Resultado del Tratamiento , Paro Cardíaco/diagnóstico , Mortalidad Hospitalaria , Intervención Coronaria Percutánea/efectos adversosRESUMEN
Despite aggressive care, patients with cardiopulmonary failure and COVID-19 experience unacceptably high mortality rates. The use of mechanical circulatory support devices in this population offers potential benefits but confers significant morbidity and novel challenges for the clinician. Thoughtful application of this complex technology is of the utmost importance and should be done in a multidisciplinary fashion by teams familiar with mechanical support devices and aware of the particular challenges provided by this complex patient population.
Asunto(s)
Circulación Asistida , COVID-19 , Humanos , COVID-19/epidemiología , COVID-19/terapiaRESUMEN
Timing of craniofacial suture fusion is important for the determination of demographics and primate ontogeny. There has been much work concerning the timing of fusion of calvarial sutures over the last century, but little comprehensive work focusing on facial sutures. Here we assess the relationships of facial suture fusion across ontogeny among select catarrhines. Fusion timing patterns for 5 facial sutures were examined in 1,599 crania of Homo, Pan, Gorilla, Pongo, Hylobatidae, Papio, and Macaca. Calvarial volume (early ontogeny) and dental eruption (late ontogeny) were used as indicators of stage of development. General linear models, test for homogeneity of slopes, and ANOVA were used to determine differences in timing of fusion by taxon. For calvarial volume, taxonomic groups segregated by regression slopes, with models for Homo indicating sutural fusion throughout ontogeny, Pongo, Macaca, and Papio representing earlier and more complete suture fusion, and Pan, Gorilla, and Hylobatidae indicating very early facial suture fusion. Similar patterns are observed when dental eruption is used for developmental staging. Only Gorilla and Hylobatidae are observed to, generally, fuse all facial suture sites in adulthood. Finally, Homo appears to be unique in its delay and patency of sutures into late ontogeny. The taxonomic patterns of facial suture closure identified in this study likely reflect important evolutionary shifts in facial growth and development in catarrhines.
Asunto(s)
Suturas Craneales , Hominidae , Cráneo , Animales , Hominidae/anatomía & histología , Cráneo/anatomía & histologíaRESUMEN
BACKGROUND: Takotsubo syndrome (TS) is an acute cardiac condition with presentation indistinguishable from acute coronary syndrome (ACS), and mechanism independent of epicardial coronary obstruction. Acute coronary artery plaque rupture/occlusion is not expected in TS. Nonetheless, the physiologic stress of ACS might itself trigger TS, leading to coexistence of both conditions, and diagnostic uncertainty. METHODS: From 2011 to 2014, we encountered 137 consecutive patients with typical TS (without acute coronary plaque rupture/occlusion). During this time, among a population of 3,506 consecutive ACS patients, nine (0.3%) presented with features of both ACS and TS, that is, acute onset, troponin elevation, acute plaque rupture/occlusion, and reversible LV ballooning not corresponding to culprit coronary distribution. RESULTS: The nine patients (seven female) with TS-ACS coexistence, average age 70 ± 13 years, presented with chest pain (n = 6), nausea/vomiting (n = 2), or cardiac arrest (n = 1), ST-elevation (n = 5), all with troponin elevation (peak 1.3 ± 1.2 ng/ml). Each had single vessel coronary disease; right coronary (n = 3), circumflex (n = 3), mid-LAD (n = 2), ramus intermedius (n = 1), with percutaneous coronary intervention in seven patients (78%). Initial ejection fraction was 26 ± 7%, with apical ballooning in eight patients and mid-LV ballooning in one patient. Each patient had LV ballooning resolution and ejection fraction normalization to 57 ± 3%, hospital survival was 89%. CONCLUSIONS: Among patients with ACS, a subset have evidence of coexisting TS, findings which further expand the clinical profile of both conditions, raising the possibility that ACS itself may trigger TS.
Asunto(s)
Síndrome Coronario Agudo/complicaciones , Cardiomiopatía de Takotsubo/complicaciones , Síndrome Coronario Agudo/diagnóstico , Síndrome Coronario Agudo/mortalidad , Síndrome Coronario Agudo/fisiopatología , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Angiografía Coronaria , Diagnóstico Diferencial , Electrocardiografía , Femenino , Mortalidad Hospitalaria , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Pronóstico , Factores de Riesgo , Volumen Sistólico , Cardiomiopatía de Takotsubo/diagnóstico , Cardiomiopatía de Takotsubo/mortalidad , Cardiomiopatía de Takotsubo/fisiopatología , Troponina/sangre , Función Ventricular IzquierdaRESUMEN
'Macrosmatic' mammals have dedicated olfactory regions within their nasal cavity and segregated airstreams for olfaction and respiratory air-conditioning. Here, we examined the 3D distribution of olfactory surface area (SA) and nasal airflow patterns in the pygmy slow loris (Nycticebus pygmaeus), a primate with primitive nasal cavities, except for enlarged eyes that converge upon the posterodorsal nasal region. Using the head of an adult loris cadaver, we co-registered micro-computed tomography (CT) slices and histology sections to create a 3D reconstruction of the olfactory mucosa distribution. Histological sections were used to measure olfactory surface area and to annotate CT reconstructions. The loris has a complex olfactory recess (â¼19% of total nasal SA) with multiple olfactory turbinals. However, the first ethmoturbinal has a rostral projection that extends far anterior to the olfactory recess, lined by â¼90% non-olfactory epithelium. Only one (of three) frontoturbinals bears olfactory mucosa. Computational fluid dynamics simulations of nasal airflow and odorant deposition revealed that there is some segregation of respiratory and olfactory flow in the loris nose, but that it is not as distinct as in well-studied 'macrosmats' (e.g. the dog). In the loris, airflow is segregated medially and laterally to vertically elongated, plate-like first ethmoturbinals. Thus, lorises may be said to have certain macrosmatic anatomical characteristics (e.g. olfactory recess), but not segregated nasal airflow patterns that are optimized for olfaction, as in canids. These results imply that a binary 'microsmatic/macrosmatic' dichotomy does not exist. Rather, mammals appear to exhibit complex trends with respect to specialization of the turbinals and recesses.
Asunto(s)
Lorisidae/fisiología , Cavidad Nasal/fisiología , Mucosa Olfatoria/fisiología , Ventilación Pulmonar , Movimientos del Aire , Animales , Cadáver , Hidrodinámica , Masculino , Cavidad Nasal/diagnóstico por imagen , Microtomografía por Rayos X/veterinariaRESUMEN
Computed tomography X-ray imaging of the internal face in well-preserved primate fossil crania permits reconstruction of the nature of their nasal anatomy, including some soft-tissue features. These features are diagnostic of the primate suborder Haplorhini, and allow reevaluation of the phylogenetic status of several purported early members of the group. Here we examine the nasolacrimal morphology of a broad sample of extant primates, as well as a number of Paleogene fossils. The extant sample confirms the distinctiveness of the two suborders. Of the fossils studied, only Shoshonius cooperi from the late-early Eocene exhibits evidence of a haplorhine nose. This suggests that the haplorhine oronasal complex may have evolved before the postorbital septum, and strengthens the claim that Shoshonius is a close relative of tarsiers and anthropoids. These results indicate that Omomyiformes is not a monophyletic group, and that few of its members possessed the derived oronasal morphology that characterizes crown haplorhines.
Asunto(s)
Evolución Biológica , Fósiles/anatomía & histología , Haplorrinos/anatomía & histología , Animales , Haplorrinos/clasificación , FilogeniaRESUMEN
Filamentous fungi produce diverse secondary metabolites (SMs) essential to their ecology and adaptation. Although each SM is typically produced by only a handful of species, global SM production is governed by widely conserved transcriptional regulators in conjunction with other cellular processes, such as development. We examined the interplay between the taxonomic narrowness of SM distribution and the broad conservation of global regulation of SM and development in Aspergillus, a diverse fungal genus whose members produce well-known SMs such as penicillin and gliotoxin. Evolutionary analysis of the 2,124 genes comprising the 262 SM pathways in four Aspergillus species showed that most SM pathways were species-specific, that the number of SM gene orthologs was significantly lower than that of orthologs in primary metabolism, and that the few conserved SM orthologs typically belonged to non-homologous SM pathways. RNA sequencing of two master transcriptional regulators of SM and development, veA and mtfA, showed that the effects of deletion of each gene, especially veA, on SM pathway regulation were similar in A. fumigatus and A. nidulans, even though the underlying genes and pathways regulated in each species differed. In contrast, examination of the role of these two regulators in development, where 94% of the underlying genes are conserved in both species showed that whereas the role of veA is conserved, mtfA regulates development in the homothallic A. nidulans but not in the heterothallic A. fumigatus. Thus, the regulation of these highly conserved developmental genes is divergent, whereas-despite minimal conservation of target genes and pathways-the global regulation of SM production is largely conserved. We suggest that the evolution of the transcriptional regulation of secondary metabolism in Aspergillus represents a novel type of regulatory circuit rewiring and hypothesize that it has been largely driven by the dramatic turnover of the target genes involved in the process.
Asunto(s)
Aspergillus/genética , Aspergillus/metabolismo , Evolución Biológica , Redes y Vías Metabólicas , Aspergillus/clasificación , Evolución Molecular , Genoma FúngicoRESUMEN
OBJECTIVES: An overexpression of Tgf-ß2 leads to calvarial hyperostosis and suture fusion in individuals with craniosynostosis. Inhibition of Tgf-ß2 may help rescue fusing sutures and restore normal growth. The present study was designed to test this hypothesis. DESIGN: Twenty-eight New Zealand White rabbits with delayed-onset coronal synostosis had radiopaque markers placed on either side of the coronal sutures at 10 days of age. The rabbits were randomly assigned to: (1) sham control rabbits (n = 10), (2) rabbits with control IgG (100 µg/suture) delivered in a collagen vehicle (n = 9), and (3) rabbits with Tgf-ß2 neutralizing antibody (100 µg/suture) delivered in a collagen vehicle (n = 9). Longitudinal growth data were collected at 10, 25, 42, and 84 days of age. Sutures were harvested at 84 days of age for histomorphometry. RESULTS: Radiographic analysis showed significantly greater ( P < .05) coronal suture marker separation, craniofacial length, cranial vault length, height, shape indices, cranial base length, and more lordotic cranial base angles in rabbits treated with anti-Tgf-ß2 antibody than in controls at 42 and 84 days of age. Histologically, rabbits treated with anti-Tgf-ß2 antibody at 84 days of age had patent and significantly ( P < .05) wider coronal sutures and greater sutural area compared to controls. CONCLUSIONS: These data support our hypothesis that antagonism of Tgf-ß2 may rescue fusing coronal sutures and facilitate craniofacial growth in this rabbit model. These findings also suggest that cytokine therapy may have clinical significance in infants with progressive postgestational craniosynostosis.
Asunto(s)
Suturas Craneales , Craneosinostosis , Factor de Crecimiento Transformador beta2 , Animales , Conejos , Animales Recién Nacidos , Suturas Craneales/diagnóstico por imagen , Suturas Craneales/efectos de los fármacos , Suturas Craneales/crecimiento & desarrollo , Craneosinostosis/diagnóstico por imagen , Craneosinostosis/prevención & control , Modelos Animales de Enfermedad , Distribución Aleatoria , Factor de Crecimiento Transformador beta2/antagonistas & inhibidoresRESUMEN
Ig secretion by terminally differentiated B cells is an important component of the immune response to foreign pathogens. Its overproduction is a defining characteristic of several B cell malignancies, including Waldenström macroglobulinemia (WM), where elevated IgM is associated with significant morbidity and poor prognosis. Therefore, the identification and characterization of the mechanisms controlling Ig secretion are of great importance for the development of future therapeutic approaches for this disease. In this study, we define a novel pathway involving the oncogenic transcription factor GLI2 modulating IgM secretion by WM malignant cells. Pharmacological and genetic inhibition of GLI2 in WM malignant cells resulted in a reduction in IgM secretion. Screening for a mechanism identified the IL-6Rα (gp80) subunit as a downstream target of GLI2 mediating the regulation of IgM secretion. Using a combination of expression, luciferase, and chromatin immunoprecipitation assays we demonstrate that GLI2 binds to the IL-6Rα promoter and regulates its activity as well as the expression of this receptor. Additionally, we were able to rescue the reduction in IgM secretion in the GLI2 knockdown group by overexpressing IL-6Rα, thus defining the functional significance of this receptor in GLI2-mediated regulation of IgM secretion. Interestingly, this occurred independent of Hedgehog signaling, a known regulator of GLI2, as manipulation of Hedgehog had no effect on IgM secretion. Given the poor prognosis associated with elevated IgM in WM patients, components of this new signaling axis could be important therapeutic targets.
Asunto(s)
Linfocitos B/inmunología , Inmunoglobulina M/inmunología , Factores de Transcripción de Tipo Kruppel/inmunología , Receptores de Interleucina-6/inmunología , Macroglobulinemia de Waldenström/patología , Animales , Línea Celular , Inmunoprecipitación de Cromatina , Femenino , Proteínas Hedgehog/genética , Humanos , Receptores de Hialuranos/inmunología , Inmunoglobulina M/biosíntesis , Factores de Transcripción de Tipo Kruppel/antagonistas & inhibidores , Factores de Transcripción de Tipo Kruppel/genética , Activación de Linfocitos/inmunología , Ratones , Ratones Endogámicos BALB C , Regiones Promotoras Genéticas/genética , Unión Proteica/inmunología , Receptores de Interleucina-6/biosíntesis , Transducción de Señal/inmunología , Macroglobulinemia de Waldenström/metabolismo , Proteína Gli2 con Dedos de ZincRESUMEN
OBJECTIVES: Dental eruption schedules have been closely linked to life history variables. Here we examine a sample of 50 perinatal primates (28 species) to determine whether life history traits correlate with relative tooth size at birth. MATERIALS AND METHODS: Newborn primates were studied using serial histological sectioning. Volumes of deciduous premolars (dp2 -dp4 ), replacement teeth (if any), and permanent molars (M1-2/3 ) of the upper jaw were measured and residuals from cranial length were calculated with least squares regressions to obtain relative dental volumes (RDVs). RESULTS: Relative dental volumes of deciduous or permanent teeth have an unclear relationship with relative neonatal mass in all primates. Relative palatal length (RPL), used as a proxy for midfacial size, is significantly, positively correlated with larger deciduous and permanent postcanine teeth. However, when strepsirrhines alone are examined, larger RPL is correlated with smaller RDV of permanent teeth. In the full sample, RDVs of deciduous premolars are significantly negatively correlated with relative gestation length (RGL), but have no clear relationship with relative weaning age. RDVs of molars lack a clear relationship with RGL; later weaning is associated with larger molar RDV, although correlations are not significant. When strepsirrhines alone are analyzed, clearer trends are present: longer gestations or later weaning are associated with smaller deciduous and larger permanent postcanine teeth (only gestational length correlations are significant). DISCUSSION: Our results indicate a broad trend that primates with the shortest RGLs precociously develop deciduous teeth; in strepsirrhines, the opposite trend is seen for permanent molars. Anthropoids delay growth of permanent teeth, while strepsirrhines with short RGLs are growing replacement teeth concurrently. A comparison of neonatal volumes with existing information on extent of cusp mineralization indicates that growth of tooth germs and cusp mineralization may be selected for independently.
Asunto(s)
Animales Recién Nacidos/fisiología , Odontogénesis/fisiología , Primates/fisiología , Diente Primario/anatomía & histología , Animales , Antropología Física , Femenino , Maxilar/anatomía & histología , Diente Molar/anatomía & histologíaRESUMEN
PURPOSE: Evidence from studies mainly in children has shown that orally administered probiotics may prevent respiratory tract infections and associated antibiotic use. We evaluated whether advice to take daily probiotics can reduce antibiotic prescribing for winter respiratory tract infections in people with asthma. METHODS: We conducted a randomized controlled, parallel-group pragmatic study for participants aged 5 years and older with asthma in a UK primary care setting. The intervention was a postal leaflet with advice to take daily probiotics from October 2013 to March 2014, compared with a standard winter advice leaflet. Primary outcome was the proportion of participants prescribed antibiotics for respiratory tract infections. RESULTS: There were 1,302 participants randomly assigned to a control group (n = 650) or intervention group (n = 652). There was no significant difference in the primary outcome measure, with 27.7% receiving antibiotics in the intervention group and 26.9% receiving antibiotics in the control group (odds ratio = 1.04; 95% CI, 0.82-1.34). Uptake of probiotics was low, but outcomes were similar in those who accessed probiotics (adjusted odds ratio = 1.08; 95% CI, 0.69-1.69, compared with controls). We also found no evidence of an effect on respiratory tract infections or asthma exacerbations. CONCLUSIONS: In this pragmatic community-based trial in people with asthma, we found no evidence that advising use of winter probiotics reduces antibiotic prescribing.
Asunto(s)
Antibacterianos/uso terapéutico , Asma/complicaciones , Prescripciones de Medicamentos/estadística & datos numéricos , Probióticos/administración & dosificación , Infecciones del Sistema Respiratorio/prevención & control , Infecciones del Sistema Respiratorio/terapia , Adolescente , Adulto , Anciano , Niño , Preescolar , Progresión de la Enfermedad , Costos de los Medicamentos , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Pautas de la Práctica en Medicina , Atención Primaria de Salud , Estudios Prospectivos , Reino Unido , Adulto JovenRESUMEN
Aspergillus fumigatus is the leading causative agent of invasive aspergillosis (IA). The number of cases is on the rise, with mortality rates as high as 90% among immunocompromised patients. Molecular genetic studies in A. fumigatus could provide novel targets to potentially set the basis for antifungal therapies. In the current study, we investigated the role of the transcription factor gene mtfA in A. fumigatus. Our results revealed that mtfA plays a role in the growth and development of the fungus. Deletion or overexpression of mtfA leads to a slight reduction in colony growth, as well as a reduction in conidiation levels, in the overexpression strain compared to the wild-type strain. Furthermore, production of the secondary metabolite gliotoxin increased when mtfA was overexpressed, coinciding with an increase in the transcription levels of the gliotoxin genes gliZ and gliP with respect to the wild type. In addition, our study showed that mtfA is also necessary for normal protease activity in A. fumigatus; deletion of mtfA resulted in a reduction of protease activity compared to wild-type levels. Importantly, the absence of mtfA caused a decrease in virulence in the Galleria mellonella infection model, indicating that mtfA is necessary for A. fumigatus wild-type pathogenesis.
Asunto(s)
Aspergillus nidulans/metabolismo , Proteínas Fúngicas/metabolismo , Gliotoxina/biosíntesis , Factores de Transcripción/metabolismo , Aspergillus nidulans/genética , Aspergillus nidulans/crecimiento & desarrollo , Aspergillus nidulans/patogenicidad , Proteínas Fúngicas/genética , Péptido Hidrolasas/metabolismo , Esporas Fúngicas/crecimiento & desarrollo , Factores de Transcripción/genética , Virulencia/genética , Factores de Virulencia/genética , Factores de Virulencia/metabolismoRESUMEN
The vomeronasal organ (VNO), also known as the Jacobson's organ, is a bilateral chemosensory organ found at the base of the nasal cavity specialized for the detection of higher-molecular weight (non-volatile) chemostimuli. It has been linked to pheromone detection. The VNO has been well studied in nocturnal lemurs and lorises, but poorly studied in diurnal/cathemeral species despite the large repertoire of olfactory behaviors noted in species such as Lemur catta. Here, the VNO and associated structures were studied microanatomically in one adult female and one adult male L. catta. Traditional and immunohistochemical procedures demonstrate the VNO epithelium consists of multiple rows of sensory neurons. Immunoreactivity to Growth-associated protein 43 (GAP43) indicates the VNO is postnatally neurogenic. In volume, the VNO neuroepithelium scales similarly to palatal length compared to nocturnal strepsirrhines. Numerous taste buds present at the oral opening to the nasopalatine duct, with which the VNO communicates, provide an additional (or alternative) explanation for the flehmen behavior that has been observed in this species. The VNO of L. catta is shown to be microanatomically comparable to that of nocturnal strepsirrhines. Like nocturnal strepsirrhines, the VNO of L. catta may be functional in the reception of high-molecular weight secretions.
Asunto(s)
Lemur/anatomía & histología , Órgano Vomeronasal/anatomía & histología , Animales , Femenino , Proteína GAP-43 , Inmunohistoquímica , Lemur/fisiología , Masculino , Neuronas Receptoras Olfatorias/citología , Papilas Gustativas/anatomía & histología , Órgano Vomeronasal/fisiologíaRESUMEN
The olfactory recess - a blind pocket at the back of the nasal airway - is thought to play an important role in mammalian olfaction by sequestering air outside of the main airstream, thus giving odorants time to re-circulate. Several studies have shown that species with large olfactory recesses tend to have a well-developed sense of smell. However, no study has investigated how the size of the olfactory recess relates to air circulation near the olfactory epithelium. Here we used a computer model of the nasal cavity from a bat (Carollia perspicillata) to test the hypothesis that a larger olfactory recess improves olfactory airflow. We predicted that during inhalation, models with an enlarged olfactory recess would have slower rates of flow through the olfactory region (i.e. the olfactory recess plus airspace around the olfactory epithelium), while during exhalation these models would have little to no flow through the olfactory recess. To test these predictions, we experimentally modified the size of the olfactory recess while holding the rest of the morphology constant. During inhalation, we found that an enlarged olfactory recess resulted in lower rates of flow in the olfactory region. Upon exhalation, air flowed through the olfactory recess at a lower rate in the model with an enlarged olfactory recess. Taken together, these results indicate that an enlarged olfactory recess improves olfactory airflow during both inhalation and exhalation. These findings add to our growing understanding of how the morphology of the nasal cavity may relate to function in this understudied region of the skull.
Asunto(s)
Quirópteros/anatomía & histología , Quirópteros/fisiología , Simulación por Computador , Modelos Anatómicos , Modelos Biológicos , Olfato , Animales , Espiración , Cavidad Nasal/anatomía & histología , Cavidad Nasal/fisiología , Mucosa Olfatoria/anatomía & histología , Mucosa Olfatoria/fisiologíaRESUMEN
The aflatoxin-producer and opportunistic plant pathogenic, filamentous fungus Aspergillus flavus is responsible for the contamination of corn and other important agricultural commodities. In order to obtain nutrients from the host A. flavus produces a variety of extracellular hydrolytic enzymes. Interestingly, A. flavus amylase and protease activity are dependent on the global regulator veA, a gene known to regulate morphogenesis and secondary metabolism in numerous fungi. Analysis of starch degradation by fungal enzymes secreted into broths of starch- or corn kernel-based media showed a notable accumulation of glucose in samples of the A. flavus control strain while the deletion veA sample accumulated high levels of maltose and maltotriose and only a small amount of glucose. Furthermore, SDS-PAGE and proteomics analysis of culture broths from starch- or corn kernel-based media demonstrated differential production of a number of proteins that included a reduction in the amount of a glucoamylase protein in the veA mutant compared to the control strain, while an alpha-amylase was produced in greater quantities in the veA mutant. Quantitative real-time PCR and western blot analyses using anti-glucoamylase or alpha-amylase antisera supported the proteomics results. Additionally, an overall reduction in protease activity was observed in the veA mutant including production of the alkaline protease, oryzin, compared to the control strain. These findings contribute to our knowledge of mechanisms controlling production of hydrolases and other extracellular proteins during growth of A. flavus on natural starch-based substrates.
Asunto(s)
Aspergillus flavus/crecimiento & desarrollo , Aspergillus flavus/metabolismo , Regulación Fúngica de la Expresión Génica , Genes Reguladores , Hidrolasas/metabolismo , Almidón/metabolismo , Aspergillus flavus/genética , Western Blotting , Medios de Cultivo , Perfilación de la Expresión Génica , Genes Fúngicos , Reacción en Cadena en Tiempo Real de la Polimerasa , Eliminación de SecuenciaRESUMEN
Midfacial reduction in primates has been explained as a byproduct of other growth patterns, especially the convergent orbits. This is at once an evolutionary and developmental explanation for relatively short snouts in most modern primates. Here, we use histological sections of perinatal nonhuman primates (tamarin, tarsier, loris) to investigate how orbital morphology emerges during ontogeny in selected primates compared to another euarchontan (Tupaia glis). We annotated serial histological sections for location of osteoclasts or osteoblasts, and used these to create three-dimensional "modeling maps" showing perinatal growth patterns of the facial skeleton. In addition, in one specimen we transferred annotations from histological sections to CT slices, to create a rotatable 3D volume that shows orbital modeling. Our findings suggest that growth in the competing orbital and neurocranial functional matrices differs among species, influencing modeling patterns. Distinctions among species are observed in the frontal bone, at a shared interface between the endocranial fossa and the orbit. The medial orbital wall is extensively resorptive in primates, whereas the medial orbit is generally depositional in Tupaia. As hypothesized, the orbital soft tissues encroach on available interorbital space. However, eye size cannot, by itself, explain the extent of reduction of the olfactory recess. In Loris, the posterior portion of medial orbit differed from the other primates. It showed evidence of outward drift where the olfactory bulb increased in cross-sectional area. We suggest the olfactory bulbs are significant to orbit position in strepsirrhines, influencing an expanded interorbital breadth at early stages of development.