RESUMO
To evaluate the potential role of phenolic compounds in Al and Cd stress tolerance mechanisms, Vaccinium corymbosum cv. Legacy plantlets were exposed to different metal concentrations. The present study used an in vitro plant model to test the effects of the following treatments: 100µM Al; 100µMAl + 50µMCd; and 100µMAl + 100µMCd during periods of 7, 14, 21 and 30 days. The oxidative damage was determined by the accumulation of malondialdehyde (MDA) and hydrogen peroxide (H2O2). The antioxidant activity values were determined using 1,1-diphenyl-2-picrylhydrazine (DPPH) and the ferric reducing antioxidant power test (FRAP). Additionally, the phenolic compound concentrations were determined using HPLC-DAD. The exposure to Al and Cd increased the MDA and H2O2 contents differentially, while the antioxidant capacity values showed differences between DPPH and FRAP with the largest changes in FRAP relative to Cd. SOD had the highest activity in the first 7 days, leading to a significant increase in phenolic compounds observed after 14 days, and chlorogenic acid was the major compound identified. Our results revealed that phenolic compounds seem to play an important role in the response to ROS. Therefore, the mechanisms of tolerance to Al and Cd in V. corymbosum will be determined by the type of metal and time of exposure.
Assuntos
Alumínio/toxicidade , Antioxidantes/metabolismo , Mirtilos Azuis (Planta)/efeitos dos fármacos , Cádmio/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Fenóis/metabolismo , Poluentes do Solo/toxicidade , Mirtilos Azuis (Planta)/enzimologia , Mirtilos Azuis (Planta)/crescimento & desenvolvimento , Modelos Teóricos , OxirreduçãoRESUMO
The distribution range of the western pine beetle Dendroctonus brevicomis LeConte (Coleoptera: Curculionidae) is supported only by scattered records in the northern parts of Mexico, suggesting that its populations may be marginal and rare in this region. In this study, we review the geographical distribution of D. brevicomis in northern Mexico and perform a geometric morphometric analysis of seminal rod shape to evaluate its reliability for identifying this species with respect to other members of the Dendroctonus frontalis Zimmermann (Coleoptera: Curculionidae) complex. Our results provide 30 new records, with 26 distributed in the Sierra Madre Occidental and 4 in the Sierra Madre Oriental. These records extend the known distribution range of D. brevicomis to Durango and Tamaulipas states in northern Mexico. Furthermore, we find high geographic variation in size and shape of the seminal rod, with conspicous differences among individuals from different geographical regions, namely west and east of the Great Basin and between mountain systems in Mexico.
Assuntos
Distribuição Animal , Gorgulhos/classificação , Gorgulhos/fisiologia , Animais , Masculino , México , Pinus , Gorgulhos/anatomia & histologiaRESUMO
Cadmium (Cd(2+)) can affect plant growth due to its mobility and toxicity. We evaluated the effects of Cd(2+) on the production of phenolic compounds and antioxidant response of Vaccinium corymbosum L. Plantlets were exposed to Cd(2+) at 50 and 100µM for 7, 14 and 21 days. Accumulation of malondialdehyde (MDA), hydrogen peroxide (H2O2) and the antioxidant enzyme SOD was determined. The profile of phenolic compounds was evaluated using LC-MS. The antioxidant activity was measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the ferric reducing antioxidant power test (FRAP). Cd(2+) increased the content of MDA, with the highest increase at 14 days. The presence of Cd(2+) resulted in changes in phenolic compounds. The main phenolic compound found in blueberry plantlets was chlorogenic acid, whose abundance increased with the addition of Cd(2+) to the medium. The changes in the composition of phenolic compounds showed a positive correlation with the antioxidant activity measured using FRAP. Our results suggest that blueberry plantlets produced phenolic compounds with reducing capacity as a selective mechanism triggered by the highest activity of Cd(2+).
Assuntos
Mirtilos Azuis (Planta)/efeitos dos fármacos , Cádmio/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Fenóis/metabolismo , Antioxidantes/farmacologia , Compostos de Bifenilo , Esquema de Medicação , Peróxido de Hidrogênio/farmacologia , Malondialdeído/metabolismo , Oxirredução , Picratos , Poluentes do Solo/química , Poluentes do Solo/toxicidadeRESUMO
Bark beetles of the genus Dendroctonus are important components of coniferous forests. During host colonization, they must overcome the chemical defences of their host trees, which are metabolized by cytochrome P450 (CYP or P450) enzymes to compounds that are readily excreted. In this study, we report the relative expression (quantitative real-time PCR) of four orthologous cytochrome P450 genes (CYP6BW5, CYP6DG1, CYP6DJ2 and CYP9Z20) in Dendroctonus rhizophagus and Dendroctonus valens forced to attack host trees at 8 and 24 h following forced attack and in four stages during natural colonization [solitary females boring the bark (T1); both male and female members of couples before oviposition (T2); both male and female members of couples during oviposition (T3), and solitary females inside the gallery containing eggs (T4)]. For both species gene expression was different compared with that observed in insects exposed to single monoterpenes in the laboratory, and the expression patterns were significantly different amongst species, sex, gut region and exposure time or natural colonization stage. The induction of genes (CYP6BW5v1, CYP6DJ2v1 and CYP9Z20v1 from D. rhizophagus, as well as CYP6DG1v3 from D. valens) correlated with colonization stage as well as with the increase in oxygenated monoterpenes in the gut of both species throughout the colonization of the host. Our results point to different functions of these orthologous genes in both species.
Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Pinus/parasitologia , Gorgulhos/enzimologia , Animais , Sistema Enzimático do Citocromo P-450/química , Sistema Enzimático do Citocromo P-450/genética , Feminino , Trato Gastrointestinal/enzimologia , Regulação da Expressão Gênica , Masculino , México , Monoterpenos/metabolismo , Oviposição , Pinus/metabolismo , Fatores de Tempo , Gorgulhos/genéticaRESUMO
Orbital emphysema is a rare complication of orbital and facial trauma, involving the sinuses and occasionally the nasal cavity. Most cases occur as a result of trauma but spontaneous orbital emphysema has been reported. Clinical manifestations are often delayed until the upper airway pressure increases as when blowing or coughing. Along with the fracture, the rupture of the underlying mucosa is essential for emphysema to manifest. We report a 29-years-old male who consulted in the emergency room due to eyelid swelling after a Valsalva maneuver, a couple of hours after suffering a facial injury secondary to a fall. In the presence of eyelid emphysema, the patient underwent craniofacial imaging studies, confirming an ethmoidal lamina papyracea fracture.
Assuntos
Acidentes por Quedas , Osso Etmoide/lesões , Fraturas Orbitárias/etiologia , Fraturas Cranianas/diagnóstico por imagem , Enfisema Subcutâneo/etiologia , Manobra de Valsalva , Adulto , Epistaxe/complicações , Osso Etmoide/diagnóstico por imagem , Humanos , Masculino , Fraturas Orbitárias/diagnóstico por imagem , Radiografia , Remissão Espontânea , Enfisema Subcutâneo/diagnóstico por imagemRESUMO
The livelihood of inhabitants from rural agricultural valleys in the arid Arica and Parinacota Region, northernmost Chile, strongly depends on water from high altitude rainfall and runoff to lower elevation areas. However, elevated arsenic, boron, and other potentially harmful elements compromise water quality, especially in rural areas. Samples (n = 90) of surface, underground, cold, geothermal springs, and treated and raw tap water were studied to assess water quality and to determine the main geochemical controls on water composition, origin, and geochemical evolution along dominant flowpaths. Water from major river basins across the region (Lluta, San Jose, Codpa-Chaca, Camarones and Altiplanicas) were collected for hydrogeochemical analysis of a suite of major and trace elements, δD and δ18O. Our new dataset was supplemented by hydrochemical data (n > 1500 data points) from secondary sources. Results show that 72% of the collected samples had As >10 µg/L (WHO drinking water provisional guideline) and affected 44% of the studied waters used for drinking (n = 32). Based on Chilean irrigation guidelines, elevated salinity (EC > 0.75 mS/cm) affected 80% of sampled waters, which were also impacted by high B (89% > 0.75 mg/L), and As (31% > 50 µg/L). Water composition was strongly controlled by geothermal water and freshwater mixing in high altitude areas. Magnitude and fate of As and B concentration was determined by the geothermal input type. Highest As (~21 mg/L) was associated with circum-neutral Na-Cl waters in Camarones basin, while lower As (~5 mg/L) with acid SO4 waters in Lluta basin. Additionally, evaporative concentration and sediment-water interactions were shown to control the level of As in surface and groundwaters downstream. This works provides a comprehensive analysis and a conceptual model of geochemical controls on regional water compositions, contributing to better understanding the geochemical processes underpinning the water quality challenges in northern Chile.
Assuntos
Arsênio , Água Subterrânea , Poluentes Químicos da Água , Arsênio/análise , Boro , Chile , Monitoramento Ambiental , Poluentes Químicos da Água/análiseRESUMO
Central chemoreception is essential for adjusting breathing to physiological demands, and for maintaining CO2 and pH homeostasis in the brain. CO2-induced ATP release from brainstem astrocytes stimulates breathing. NMDA receptor (NMDAR) antagonism reduces the CO2-induced hyperventilation by unknown mechanisms. Here we show that astrocytes in the mouse caudal medullary brainstem can synthesize, store, and release D-serine, an agonist for the glycine-binding site of the NMDAR, in response to elevated CO2 levels. We show that systemic and raphe nucleus D-serine administration to awake, unrestrained mice increases the respiratory frequency. Application of D-serine to brainstem slices also increases respiratory frequency, which was prevented by NMDAR blockade. Inhibition of D-serine synthesis, enzymatic degradation of D-serine, or the sodium fluoroacetate-induced impairment of astrocyte functions decrease the basal respiratory frequency and the CO2-induced respiratory response in vivo and in vitro. Our findings suggest that astrocytic release of D-serine may account for the glutamatergic contribution to central chemoreception.Astrocytes are involved in chemoreception in brainstem areas that regulate breathing rhythm, and astrocytes are known to release D-serine. Here the authors show that astrocyte release of D-serine contributes to CO2 sensing and breathing in brainstem slices, and in vivo in awake unrestrained mice.
Assuntos
Astrócitos/metabolismo , Tronco Encefálico/metabolismo , Dióxido de Carbono/metabolismo , Serina/metabolismo , Animais , Astrócitos/efeitos dos fármacos , Tronco Encefálico/citologia , Células Cultivadas , Feminino , Fluoracetatos/farmacologia , Hipercapnia/metabolismo , Hipercapnia/fisiopatologia , Masculino , Camundongos Endogâmicos , Receptores de N-Metil-D-Aspartato/metabolismo , RespiraçãoRESUMO
OBJETIVO: Evaluar concordancia de sitios de hallazgos de endometriosis profunda encontrados por RM y laparoscopia. MATERIALES Y MÉTODOS: Estudio retrospectivo, no experimental, concordancia intertécnica. Se recolectaron datos en nuestra institución de todos los informes de RM de pelvis que incluyeran la palabra "endometriosis", entre mayo de 2015 y abril de 2018 (36 meses), identificando 339 registros. Se establecieron criterios de inclusión. De los 339 registros, 62 pacientes fueron excluidas por cirugía antes de la RM. Otras 243 pacientes fueron excluidas porque no presentaban registro de protocolo quirúrgico posterior a la RM. 34 pacientes cumplieron los criterios de inclusión del estudio, lo que equivale al 10% de las RM estudiadas. Se revisaron las ubicaciones de los implantes endometriósicos informados en RM y se correlacionaron con los hallazgos encontrados en la cirugía. Se confecciono tabla para identificar la presencia/ausencia de implantes en las ubicaciones descritas en la literatura. Análisis estadístico mediante software Stata, aplicando kappa ponderada con intervalo de confianza de 95%. RESULTADOS: El promedio de edad de las pacientes llevadas a cirugía fue de 38 años. Los lugares con correlación moderada-importante (0.41-0.80) correspondieron a útero, recto-sigmoides, ovario, vagina y fondos de saco. CONCLUSIÓN: La RM de Pelvis es fundamental en la evaluación de pacientes con endometriosis en las que se plantea un manejo quirúrgico, con el objetivo de caracterizar la ubicación, forma y número de lesiones, y así lograr un satisfactorio tratamiento laparoscópico.
OBJECTIVE: To assess inter-observer reliability of sites of deep endometriosis findings found by MRI and laparoscopy. MATERIALS AND METHODS: Retrospective, non-experimental study, inter-observer reliability. Data were collected at our institution from all pelvic MRI reports that included the word "endometriosis", between May 2015 and April 2018 (36 months), identifying 339 records. The following were established as inclusion criteria. Of the 339 records, 62 patients were excluded for surgery prior to MRI. Another 243 patients were excluded because they had no record of the surgical protocol after the MRI. 34 patients met the study inclusion criteria, equivalent to 10% of the MRIs studied. The locations of the endometrial implants reported on MRI were reviewed and correlated with the findings found in the surgery. A table was prepared to identify the presence / absence of implants in the locations described in the literature. Statistical analysis using Stata software, applying weighted kappa with a 95% confidence interval. RESULTS: The average age of the patients undergoing surgery was 38 years. The places with a moderate-important correlation (0.41-0.80) corresponded to the uterus, recto-sigmoid, ovary, vagina, and recto-uterine pouch. CONCLUSION: Pelvic MRI is essential in the evaluation of patients with endometriosis in whom surgical management is proposed, in order to characterize the location, shape and number of lesions, and thus achieve satisfactory laparoscopic treatment.
Assuntos
Humanos , Feminino , Adulto , Imageamento por Ressonância Magnética , Laparoscopia , Endometriose/cirurgia , Endometriose/diagnóstico por imagem , Intervalos de Confiança , Estudos RetrospectivosRESUMO
The study of phenotypic and genetic variation of obligate parthenogenetic organisms contributes to an understanding of evolution in the absence of genetic variation produced by sexual reproduction. Eriosoma lanigerum Hausmann undergoes obligate parthenogenesis in Mexico City, Mexico, due to the unavailability of the host plants required for sexual reproduction. We analysed the phenotypic and genetic variation of E. lanigerum in relation to the dry and wet season and plant phenology. Aphids were collected on two occasions per season on a secondary host plant, Pyracantha koidzumii, at five different sites in the southern area of Mexico City, Mexico. Thirteen morphological characteristics were measured from 147 to 276 individuals per site and per season. A multivariate analysis of variance was performed to test the effect of the season, site and their interaction on morphological traits. Morphological variation was summarised using a principal component analysis. Genetic variation was described using six enzymatic loci, four of which were polymorphic. Our study showed that the site and season has a significant effect on morphological trait variation. The largest aphids were recorded during cold temperatures with low relative humidity and when the plant was at the end of the fruiting period. The mean genetic diversity was low (mean H e = .161), and populations were genetically structured by season and site. Morphological and genetic variations appear to be associated with environmental factors that directly affect aphid development and/or indirectly by host plant phenology.
Assuntos
Afídeos/genética , Variação Genética , Estações do Ano , Animais , Afídeos/anatomia & histologia , México , Fenótipo , PyracanthaRESUMO
Genotypic differences in Helicobacter pylori play an important role in infection. We characterized the diversity of the cagA, cagE, babA2, and vacA genes in H. pylori strains isolated from pediatric patients and the relationship between these genes and clinical disease. Additionally, we employed the Neighbor-net algorithm to predict the behavior of the genotypes of the strains isolated from patients. Of 93 patients analyzed, 32 were positive for infection. A total of 160 H. pylori strains (five isolates per positive patient) were analyzed. A total of 91% and 83% of strains possessed the cagA and cagE genes, respectively. For the vacA gene, 84% of strains possessed the s1 allele, 15% the s2 allele, 81% the m1 allele and 13.8% the m2 allele. The babA2 gene was present in 79% of strains. Infection with H. pylori strains with the vacA (s1m1) genotype was associated with risk of esophagitis and gastritis (p=0.0001). The combination of cagA and vacA (s1m1) was significantly associated with abdominal pain (p=0.002); however, EPIYA type was not significantly associated with abdominal pain. A total of 16 different genotypes were identified; the most common genotype was vacAs1m1cagA+cagE+babA2+ (47.5%). A total of 84% of pediatric patients were infected by at least two and up to five different genotypes. The network recovered two genotype groups (A: strains with vacAs1 and B: strains with vacAs2). The presence of multiple paths in the network suggests that reticulate events, such as recombination or reinfection, have contributed to the observed genotypic diversity.
Assuntos
Proteínas de Bactérias/genética , Infecções por Helicobacter/microbiologia , Helicobacter pylori/genética , Helicobacter pylori/isolamento & purificação , Fatores de Virulência/genética , Adolescente , Algoritmos , Criança , Pré-Escolar , Biologia Computacional/métodos , Variação Genética , Genótipo , Infecções por Helicobacter/patologia , Helicobacter pylori/classificação , Humanos , Lactente , México , Análise de Sequência de DNARESUMO
We studied the effects of acute intracranial lesions on the respiratory sinus arrhythmia (RSA) with the use of computerized measurements of the ratio of expiratory to inspiratory R-R intervals. The RSA was reduced below the 95th percentile for age in 20 of 27 patients, an average of 2 days after an acute event. Only four patients, without neurological deficits, had a normal RSA. Two patients, with signs of secondary brain-stem compression from a mass, had an increased RSA, without the bradycardia that is usually associated with Cushing's response. Twenty-three patients had their respiratory rate controlled by positive pressure ventilation during testing, and our preliminary findings suggested that this was not responsible for reducing the RSA. Acute intracranial lesions caused a diminished RSA, perhaps by reducing supratentorial influences on vagal cardioinhibitory activity. In contrast, once signs of secondary brain-stem compression occur, the RSA is greatly increased while the heart rate remains unchanged, offering a possible method of noninvasive monitoring for this complication.
Assuntos
Arritmia Sinusal/complicações , Encefalopatias/complicações , Respiração , Doença Aguda , Adolescente , Adulto , Idoso , Arritmia Sinusal/fisiopatologia , Encefalopatias/fisiopatologia , Hemorragia Cerebral/complicações , Hemorragia Cerebral/fisiopatologia , Feminino , Humanos , Pressão Intracraniana , Masculino , Pessoa de Meia-IdadeRESUMO
We studied 10 patients with sarcoidosis and peripheral neuropathy. Six had a subacute or chronic axonal sensorimotor neuropathy without cranial neuropathy, beginning months to years after established systemic sarcoidosis. One patient had severe enough diaphragmatic weakness to require mechanical ventilation. Four patients had atypical neuropathies: acute Guillain-Barré syndrome, mononeuritis multiplex, unilateral lumbosacral plexopathy, and a purely sensory neuropathy, all before systemic sarcoidosis became evident, and all except one had cranial nerve abnormalities. Autopsy in one patient with sensorimotor neuropathy showed only scattered foci of lymphocytes in spinal roots and ganglia with nerve fiber loss.
Assuntos
Doenças do Sistema Nervoso Periférico/complicações , Sarcoidose/etiologia , Adulto , Idoso , Eletrofisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças do Sistema Nervoso Periférico/fisiopatologia , Sarcoidose/fisiopatologiaRESUMO
We present the hemodynamic and autonomic features of recurrent purely vasodepressor syncope episodes in a patient with left-sided malignant cervical adenopathy involving the carotid sinus. Extreme hypotension lasting 10 to 30 minutes, without change in heart rate, occurred spontaneously and 20 seconds after head-turning. The baseline respiratory sinus arrhythmia, heart rate response to standing and Valsalva's maneuver, and cold-induced blood pressure elevation were normal, indicating normal baroreceptor function between episodes. The episodes abated after 1 week of bedrest but reappeared within 1 day of discharge from the hospital. Syncope no longer occurred after intracranial section of the left glossopharyngeal nerve and upper rootlets of the left vagus. Autonomic testing remained normal postoperatively. A review of the literature indicates that purely vasodepressor syncope has been more common with left carotid sinus lesions.
Assuntos
Carcinoma de Células Escamosas/complicações , Seio Carotídeo/fisiopatologia , Neoplasias de Cabeça e Pescoço/complicações , Frequência Cardíaca , Hipotensão/complicações , Síncope/etiologia , Pressão Sanguínea , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/fisiopatologia , Neoplasias de Cabeça e Pescoço/diagnóstico , Neoplasias de Cabeça e Pescoço/fisiopatologia , Humanos , Hipotensão/fisiopatologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-IdadeRESUMO
The purpose of the present study was to investigate the range of micronucleated erythrocytes (MNE) in peripheral blood from splenectomized patients with and without genotoxic chemotherapy. The erythrocytes were stained with Wright and Giemsa for microscopic observation. To estimate the number of MNE, two series of 10000 erythrocytes per sample were analyzed and averaged. The results expressed as mean +/- standard deviation were as follows: control patients with genotoxic chemotherapy (n = 6) 2.5 +/- 1.5 (range 1 to 5 MNE); splenectomized patients with genotoxic chemotherapy (n = 7) 65.2 +/- 17.7 (range: 47-108) MNE and splenectomized patients without genotoxic chemotherapy (n = 13) 29.5 +/- 5.8 MNE; (range: 18.5-35.6). The MNE number in the patients treated with genotoxic chemotherapy depended on the type of drugs utilized: cyclophosphamide, mitoxantrone, vincristine, busulphan, cytosine arabinoside and hydroxyurea. Upon these results, it is suggested that splenectomized people could be useful in monitoring exposures, and the baseline MNE level would serve as each person's pre-exposure control when either chronic or acute exposure to environmental mutagens is investigated.
Assuntos
Antineoplásicos/efeitos adversos , Eritrócitos/ultraestrutura , Doenças Hematológicas/sangue , Micronúcleos com Defeito Cromossômico , Neoplasias/sangue , Adulto , Antineoplásicos/uso terapêutico , Feminino , Doenças Hematológicas/tratamento farmacológico , Doenças Hematológicas/cirurgia , Humanos , Masculino , Neoplasias/tratamento farmacológico , Neoplasias/cirurgia , EsplenectomiaRESUMO
The ability of melatonin to influence paraquat-induced genotoxicity was tested using micronucleated polychromatic erythrocytes as an index of damage in both bone marrow and peripheral blood cells of mice. Melatonin (10 mg/kg) or an equal volume of saline were administered intraperitoneally (ip) to mice 30 min prior to an ip injection of paraquat (20 mg/kgx2), and thereafter at 6-h intervals until the conclusion of the study (72 h). The number of the micronucleated polychromatic erythrocytes increased after paraquat administration both in peripheral blood and bone marrow cells. Melatonin administration to paraquat-treated mice significantly reduced micronuclei formation in both peripheral blood and bone marrow cells; these differences were apparent at 24, 48 and 72 h after paraquat administration. The induction of micronuclei was time-dependent with peak values occurring at 24 and 48 h. The reduction in paraquat-related genotoxicity by melatonin is likely due in part to the antioxidant activity of the indole. We did not observe effects of melatonin over paraquat in paraquat+melatonin groups incubated at 0, 60 and 120 min. Mitomycin C, which was used as a positive control, also caused the expected large rises in micronuclei in both bone marrow and peripheral blood cells at 24, 48 and 72 h after its administration.
Assuntos
Medula Óssea/efeitos dos fármacos , Herbicidas/toxicidade , Melatonina/farmacologia , Micronúcleos com Defeito Cromossômico/efeitos dos fármacos , Paraquat/toxicidade , Animais , Medula Óssea/patologia , Quebra Cromossômica , DNA/efeitos dos fármacos , Eritroblastos/efeitos dos fármacos , Eritroblastos/patologia , Injeções Intraperitoneais , Masculino , Melatonina/metabolismo , Camundongos , Micronúcleos com Defeito Cromossômico/patologia , Testes para Micronúcleos , Mitomicina/farmacologia , Testes de Mutagenicidade , Inibidores da Síntese de Ácido Nucleico/farmacologiaRESUMO
Diesel or its derivatives could have aneuploidogenic and/or clastogenic activity. Hence, the genotoxicity of diesel gases has been studied, considering exposure to them as potentially carcinogenic. The results obtained by different authors suggest the need to know the effects of direct and chronic exposure to diesel in humans, as in the case of the street workers called 'firebreathers' who fill their buccal cavity with diesel and then spread it to a burning torch many times during the day in order to give a 'dragon show' for 5 h a day and 6 days a week. The buccal samples of eight firebreathers were collected, processed and scored according to the criterion established by Tolbert et al., 1992 and then compared with positive and negative control groups. The results revealed that diesel was not micronucleogenic although it induces some nuclear abnormalities.
Assuntos
Gasolina/efeitos adversos , Mucosa Bucal/efeitos dos fármacos , Mutagênicos/efeitos adversos , Exposição Ocupacional/efeitos adversos , Adulto , Aberrações Cromossômicas , Feminino , Humanos , Masculino , Testes para Micronúcleos , Pessoa de Meia-Idade , Mucosa Bucal/ultraestruturaRESUMO
In this paper we report the results of a study to determine the frequencies of spontaneous micronucleated erythrocytes (MNE) in peripheral blood of 35 mammalian species. The main goal was to find mammals with a high spontaneous frequency of MNE that could, therefore, be good candidates for biomonitoring genotoxic agents in their natural habitat. We obtained 187 peripheral blood samples, but in 13 of the species we could only sample one individual. A wide range in the number of MNE (1/434 to 0/40,000 erythrocytes) was observed. Since the number of individuals per species is not high enough, this results should be cautiously considered. The cat, mouse, giraffe, pig, opossum and capuchin monkey seem to be suitable species for biomonitoring for genotoxic events.
Assuntos
Poluentes Ambientais/toxicidade , Eritrócitos/efeitos dos fármacos , Mamíferos/genética , Mutagênicos/toxicidade , Animais , Eritrócitos/metabolismo , Mamíferos/sangue , Testes para Micronúcleos , Especificidade da EspécieRESUMO
Magnetic resonance imaging (MRI), pathologic examinations, and biochemical analyses were performed on 2 different canine mutants with GM1 gangliosidosis (i.e., English Springer Spaniel and Portuguese Water Dog) and on age- and sex-matched controls. Serial MRI studies were also performed on a child with infantile-onset GM1 gangliosidosis. The affected dogs had abnormalities on MRI, including a relative increase in gray matter and an abnormal signal intensity of cerebral and cerebellar white matter observed on T2-weighted MRI. White matter changes on MRI were similar to white matter abnormalities observed in a 15-month-old boy with GM1 gangliosidosis. The weight ratio of white to gray matter from the frontal lobe was markedly reduced. Microscopic examination revealed characteristic ballooned neurons which stained lightly with Luxol-fast blue. The central cerebral and cerebellar folia white matter exhibited pallor and gliosis, while the corpus callosum and fornix stained normally with Luxol-fast blue. Axons appeared intact on Bodian staining. Ultrastructural studies revealed fewer myelinated axons in affected puppies. Total gangliosides in gray matter were elevated. Thin-layer chromatography demonstrated GM1 ganglioside as the predominant ganglioside. The amount of cerebrosides and sulfatides was reduced in the gray and white matter when compared to controls but the ratio in gray and white matter remained unchanged. Immunostaining of neutral glycolipids disclosed increased amounts of stage-specific embryonic antigen-1 glycolipid in gray matter. These findings suggest that canine models for GM1 gangliosidosis are associated with abnormal myelin development which may be similar to the human disease.
Assuntos
Encefalopatias Metabólicas/patologia , Encéfalo/patologia , Doenças Desmielinizantes/patologia , Modelos Animais de Doenças , Gangliosidose GM1/patologia , Doenças por Armazenamento dos Lisossomos/patologia , Bainha de Mielina/patologia , Animais , Córtex Cerebral/patologia , Cães , Feminino , Glicoesfingolipídeos/análise , Imageamento por Ressonância Magnética , Masculino , Microscopia EletrônicaRESUMO
This article describes the culture of epithelial cells from anterior and posterior midgut regions of adult Dendroctonus valens. Culture conditions were established, and cell adherence was improved by means of a new technique that allowed the cells to grow between two glass coverslips. Cytoplasmic projections occur as anterior midgut cells grow to confluence; these projections were not observed in cells of the posterior midgut. The optimal culture medium for the maintenance of these epithelial cells was Roswell Park Memorial Institute 1640 medium at 25 degrees C. Cells in Grace's medium died in 24 h. Cultures did not require CO(2) atmosphere, but culture development was favored by the microaerophilic environment and the dark conditions in which the cells were grown, between the coverslips.
Assuntos
Técnicas de Cultura de Células/métodos , Besouros/citologia , Células Epiteliais , Animais , Extensões da Superfície Celular/metabolismo , Células Cultivadas , Meios de Cultura/química , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Trato Gastrointestinal/citologiaRESUMO
Peroxidase enzymes have been found in soluble, ionically bound, and covalently bound forms and have been implicated in several physiological processes in plants. This paper investigates the effect of aphid infestation on soluble and bound-cell wall peroxidase activity and bound-cell wall isoform changes of barley plants. Peroxidase activity was measured in control plants and plants infested with the aphid Schizaphis graminum (Rondani). The activity of soluble peroxidases increased with time of infestation, older plants being more affected than younger ones. The increase in bound-cell wall peroxidase activity as a function of age was higher in infested than in control plants, being higher in ionically bound than in covalently bound peroxidases. When the aphids were removed from plants, the activities of both types of peroxidases decreased to control levels. Isoelectrofocusing analyses of the ionically bound peroxidases showed changes in the isoform pattern. A new isoform was induced by infestation. The activities of all covalently bound isoforms increased after infestation. The physiological implications of these changes are discussed.