RESUMO
Two new species of Oxyethira Eaton, 1873 are described: Oxyethira cascadanta sp. n. and Oxyethira quadrilobata sp. n. Description and illustrations of the new species are provided based on specimens collected in Parque Nacional da Serra da Canastra, Minas Gerais State, Southeast Brazil. Both species are assigned to the subgenus Loxotrichia but differ from other species mainly in morphology of the subgenital plate, subgenital processes and inferior appendages. Additionally, we provide an updated checklist of the Oxyethira species from Brazil.
Assuntos
Lista de Checagem/normas , Insetos/anatomia & histologia , Insetos/classificação , Fatores Etários , Distribuição Animal , Estruturas Animais , Animais , Brasil , Feminino , Masculino , Caracteres Sexuais , Fatores Sexuais , Especificidade da EspécieRESUMO
Spark-ignited internal combustion engines have evolved considerably in recent years in response to increasingly stringent regulations for emissions and fuel economy. One new advanced engine strategy ustilizes high levels of exhaust gas recirculation (EGR) to reduce combustion temperatures, thereby increasing thermodynamic efficiency and reducing nitrogen oxide emissions. While this strategy can be highly effective, it also poses major control and design challenges due to the large combustion oscillations that develop at sufficiently high EGR levels. Previous research has documented that combustion instabilities can propagate between successive engine cycles in individual cylinders via self-generated feedback of reactive species and thermal energy in the retained residual exhaust gases. In this work, we use symbolic analysis to characterize multi-cylinder combustion oscillations in an experimental engine operating with external EGR. At low levels of EGR, intra-cylinder oscillations are clearly visible and appear to be associated with brief, intermittent coupling among cylinders. As EGR is increased further, a point is reached where all four cylinders lock almost completely in phase and alternate simultaneously between two distinct bi-stable combustion states. From a practical perspective, it is important to understand the causes of this phenomenon and develop diagnostics that might be applied to ameliorate its effects. We demonstrate here that two approaches for symbolizing the engine combustion measurements can provide useful probes for characterizing these instabilities.
RESUMO
Optical spectra of comet Hale-Bopp (C/1995 O1) at a heliocentric distance of 6.45 astronomical units showed emission from cyanogen gas. The spatial distribution of cyanogen was considerably more diffuse and extended compared to the spatial profile of the dust or grains which were sharply peaked near the center. This behavior is consistent with comets at smaller heliocentric distances suggesting the same or a similar formation mechanism. A cyanogen gas production rate of (1.2 +/- 0.3) x10(26) molecules per second was derived. A model band profile derived from fluorescence equilibrium calculations for the comet's heliocentric velocity and distance agrees with the observed band profile.
Assuntos
Meteoroides , Nitrilas/análise , Poeira Cósmica , Gases , Análise EspectralRESUMO
The tarnished plant bug, Lygus hesperus Knight, is a pest that causes considerable economic losses to vegetables, cotton, canola, and alfalfa. Detailed knowledge of its digestive physiology will provide new opportunities for a sustainable pest management approach to control this insect. Little is known about the different protease class contributions to the overall digestion of a specific protein. To this end, the proteolytic activities in female adult L. hesperus salivary gland and midgut homogenates were quantified over a range of pH's and time points, and the contribution of different classes of proteases to the degradation of FITC-casein was determined. In the salivary gland, serine proteases were the predominant class responsible for caseinolytic activity, with the rate of activity increasing with increasing pH. In contrast, both aspartic and serine proteases contributed to caseinolytic activity in the midgut. Aspartic protease activity predominated at pH 5.0 and occurred immediately after incubation, whereas serine protease activity predominated at pH 7.5 after a 9h delay and was resistant to aprotinin. The salivary serine proteases were distinctly different from midgut serine proteases, based on the tissue-specific differential susceptibility to aprotinin and differing pH optima. Collectively, the caseinolytic activities complement one another, expanding the location and pH range over which digestion can occur.
Assuntos
Heterópteros/enzimologia , Peptídeo Hidrolases/metabolismo , Animais , Aprotinina , Caseínas/metabolismo , Feminino , Trato Gastrointestinal/enzimologia , Concentração de Íons de Hidrogênio , Glândulas Salivares/enzimologia , Serina Endopeptidases , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , beta-Endorfina/análogos & derivados , beta-Endorfina/metabolismoRESUMO
Clones of epithelial-like cells were established from urethan-induced mouse lung adenoma. Electron microscopy of one clone showed that the cells contained lamellar inclusion bodies similar in appearance to those seen in the adenoma precursor, the type II alveolar pneumocyte. The clones exhibited characteristics associated with both "transformed" and "normal" cells in culture; i.e., although aneuploid, the cells grew at a slower rate than most transformed cells, did not form colonies in soft agar and, after prolonged subculture, were not tumorigenic when transplanted s.c. into appropriate hosts. Hydrocortisone treatment of the cloned cells led to growth stimulation and the eventual acquisition of neoplastic potential. Epithelial tumors were produced more readily in athymic, nude mice than in antilymphocyte serum-treated A/He mice. The cells are producing a C-type RNA virus into the culture medium.
Assuntos
Adenoma/patologia , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/patologia , Adenoma/induzido quimicamente , Adenoma/imunologia , Aneuploidia , Animais , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Células Clonais , Hidrocortisona/farmacologia , Cariotipagem , Neoplasias Pulmonares/imunologia , Camundongos , Camundongos Endogâmicos A , Camundongos Nus/imunologia , Microscopia Eletrônica , Transplante de Neoplasias , Neoplasias Experimentais , Retroviridae , Estimulação Química , UretanaRESUMO
A pheromonotropic peptide was isolated from brain-suboesophageal ganglion complexes of the adult female gypsy moth, Lymantria dispar, using a 5-step HPLC purification protocol and an in vivo bioassay in Helicoverpa zea. The intact peptide was sequenced by automated Edman degradation. The L. dispar pheromone biosynthesis activating neuropeptide (Lyd-PBAN) is a C-terminally amidated 33-amino acid peptide with a molecular weight of 3881. The peptide was synthesized using Fmoc procedures. Lyd-PBAN has sequence homology with Hez-PBAN (81.8%) and Bom-PBAN-I (66.7%). All three PBANs share the C-terminal hexapeptide sequence, Tyr-Phe-Ser-Pro-Arg-Leu-NH2. In addition, the C-terminal pentapeptide sequences of Pseudaletia pheromonotropin (Pss-PT), Bombyx diapause hormone (Bom-DH), the locustamyotropins (Lom-MT) and leucopyrokinin (Lem-PK) are identical or have a high degree of homology to the C-terminus of PBANs.
Assuntos
Química Encefálica , Gânglios dos Invertebrados/química , Mariposas/química , Neuropeptídeos/isolamento & purificação , Atrativos Sexuais/isolamento & purificação , Sequência de Aminoácidos , Animais , Cromatografia Líquida de Alta Pressão , Esôfago/inervação , Feminino , Dados de Sequência Molecular , Neuropeptídeos/química , Homologia de Sequência de Aminoácidos , Atrativos Sexuais/químicaRESUMO
The sensitivity and specificity of maternal serum screening for Down syndrome with different biochemical markers were evaluated. Detection rates with different combinations of maternal serum alpha-fetoprotein (MSAFP), hCG, and unconjugated estriol (uE3) were established by retrieving and analyzing 54 serum specimens from women with confirmed Down syndrome pregnancies, compared with 657 specimens from women with normal outcomes. With a risk cutoff of 1:270 at the second trimester, the detection rate with MSAFP, hCG, and uE3 was two to three times higher than with MSAFP alone. With all three markers, the detection rate for Down syndrome increased from 50 to 77% as maternal age increased, and was 60% in a representative screened population. If uE3 was omitted, the detection rate decreased from 60 to 48%. One thousand women were screened prospectively, either with MSAFP or with all three markers prospectively, either with MSAFP or with all three markers and 4.1% with MSAFP. With the three markers, the positive predictive value for Down syndrome was 2.2% overall and as high as 5.9% in older women. Therefore, the addition of hCG and uE3 to the maternal serum screen increases the positive predictive value by 50-300%, depending on maternal age. These results confirm the efficacy of screening for Down syndrome using maternal age and three serum markers.
Assuntos
Síndrome de Down/diagnóstico , Estriol/sangue , Idade Materna , Gravidez de Alto Risco , Diagnóstico Pré-Natal , alfa-Fetoproteínas/análise , Biomarcadores/sangue , Doenças Fetais/diagnóstico , Humanos , Valor Preditivo dos Testes , Estudos Prospectivos , Fatores de Risco , Sensibilidade e EspecificidadeRESUMO
Neural membrane fractions, prepared from brain-subesophageal ganglion complexes of the adult lepidopteran Lymantria dispar, contain at least two peptidases capable of metabolizing locust adipokinetic hormone-I in vitro. The initial fragments, pGlu1-Leu2-Asn3 and Phe4-Thr5-Pro6-Asn7-Trp8-Gly9-Thr10, result from the action of an endopeptidase with properties similar to those reported for neutral metalloendopeptidase in Schistocerca gregaria and mammalian endopeptidase 24.11. The heptapeptide is further degraded by an aminopeptidase that exhibits kinetic properties similar to those described for aminopeptidase 3.4.11.2. These enzymes appear to be responsible for the first two steps in AKH catabolism in L. dispar.
Assuntos
Endopeptidases/metabolismo , Hormônios de Inseto/metabolismo , Lepidópteros/enzimologia , Peptídeos , Sequência de Aminoácidos , Aminopeptidases/metabolismo , Animais , Antibacterianos/farmacologia , Ácido Edético/farmacologia , Gânglios dos Invertebrados/metabolismo , Glicopeptídeos/farmacologia , Técnicas In Vitro , Lepidópteros/metabolismo , Leucina/análogos & derivados , Leucina/farmacologia , Dados de Sequência Molecular , Inibidores de Proteases/farmacologia , Tiorfano/farmacologiaRESUMO
Two new myoinhibitory peptides, Mas-MIP I and Mas-MIP II, were identified from the ventral nerve cord of the adult tobacco hornworm, Manduca sexta. Sequences obtained by a combination of automated Edman degradation and electrospray mass spectrometry were, respectively, AWQDLNSAW and GWQDLNSAW. The native peptides were found to co-elute with synthetic C-terminal amides on a reverse phase HPLC system. When applied to isolated ilea (anterior hindgut) of adult M. sexta, both peptides were found to significantly reduce the rate of peristalsis, or abolish peristalsis entirely, at concentrations of 1 x 10(-9) M. Both peptides share sequence similarities with Lom-MIP, a previously identified myoinhibitory peptide from Locusta migratoria, and with the N-terminal portion of vertebrate peptides in the galanin family.
Assuntos
Galanina/química , Hormônios de Inseto/química , Proteínas de Insetos , Manduca/química , Neuropeptídeos/análise , Neuropeptídeos/química , Abdome/inervação , Sequência de Aminoácidos , Animais , Dados de Sequência Molecular , Contração Muscular/fisiologia , Homologia de Sequência de AminoácidosRESUMO
OBJECTIVE: Withdrawal of autologous plasma and reinfusion after cardiopulmonary bypass (CPB) offers the opportunity of improving patients' haemostasis and reducing homologous blood consumption in cardiac surgery. The influence of acute, preoperative plasmapheresis (APP) on coagulation tests, fibrinolysis, blood loss and transfusion requirements was investigated in elective aortocoronary bypass patients. METHODS: Forty patients were randomized to a control or pheresis group. The pheresis group had platelet-rich plasmapheresis (PRP-group, n = 20) performed before incision and the platelet-rich plasma (PRP) was returned after CPB. The control group (n = 20) was managed without pheresis. All patients had serial coagulation studies, including prothrombin split products (F1/F2), fibrinopeptide A (FPA), protein C (PC), thrombomodulin (TM), tissue-plasminogen-activator (t-PA), plasminogen-activator-inhibitor (PAI 1), fibrinopeptide B beta 15-42 (FPB beta 15-42), haemoglobin and platelet counts determined intra- and postoperatively. Chest tube drainage and transfusion requirements were recorded. RESULTS: APP had no negative effects on the quality of PRP. The platelet count of the withdrawn autologous plasma was 239 +/- 33 x 10(9)/l. From the end of the operation (after retransfusion of autologous plasma) until the first postoperative day platelet counts were significant higher in the PRP-group (P > 0.05). Plasma concentrations of modified antithrombin III (ATM), F1/F2 and FPA increased (166-290% from baseline) and PC- and TM-antigen decreased (11-49% from baseline) to a different extent for both groups throughout CPB. t-PA-activity increased intraoperatively peaking at the end of CPB (PRP-group: 4.8 +/- 0.8 IU/ml, control-group: 8.1 +/- 2.3 IU/ml)(P > 0.05). With onset of CPB PAI-1 levels decreased and were further reduced after CPB in control patients in comparison to PRP-patients (P < 0.05). FPB beta 15-42 occurred in peak concentrations after neutralisation of heparin by protamine. Only PRP-patients showed baseline values of coagulation and fibrinolytic parameters on the next morning (P < 0.05). Total postoperative blood loss during the first 24 h was 503 +/- 251 ml (PRP-group) and 937 +/- 349 ml in the control-group (P < 0.05). None of the PRP-patients received allogeneic blood, whereas five control-patients received 11 units of packed red cells (P < 0.05). CONCLUSIONS: The findings suggest that in elective cardiac surgery heparin cannot prevent generation of both thrombin and fibrin, born throughout CPB and postoperatively. The use of PRP withdrawn immediately preoperatively is an attractive technique to reduce allogeneic blood usage and preoperative blood loss, especially in patients in whom withdrawal of autologous whole blood cannot be performed.
Assuntos
Testes de Coagulação Sanguínea , Transfusão de Componentes Sanguíneos , Perda Sanguínea Cirúrgica/fisiopatologia , Ponte de Artéria Coronária , Fibrinólise/fisiologia , Plasmaferese , Complicações Pós-Operatórias/sangue , Idoso , Idoso de 80 Anos ou mais , Transfusão de Sangue Autóloga , Ponte Cardiopulmonar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , Plaquetoferese , Cuidados Pré-Operatórios , Estudos Prospectivos , Proteína C/metabolismo , Trombomodulina/sangueRESUMO
Mechanisms for the transduction of photoperiodic and food signals to the corpus allatum (CA) are described. The focus of this paper is on the control of the CA by the brain in adult females of the firebug, Pyrrhocoris apterus. By using surgical interventions to the neuroendocrine complex of brain-subesophageal ganglion-corpora cardiaca-CA (BR-SG-CC-CA) in vivo and in vitro we were able to identify two regulatory pathways. (1) Slow regulation of the CA activity (stimulation or inhibition) needs a relatively long period of time to be accomplished (several d) in vivo and is associated with changes of the gland cell volume and ultrastructure. The stimulated or inhibited activity of the CA is maintained during short-term incubation of the isolated CA in vitro. (2) Fast inhibition of the CA activity is reversible during short-term incubation in vitro; the CA can be switched from lower to higher activity and vice versa, depending on the presence or absence of the BR-SG in the medium. Both slow and fast regulatory factors originate in the pars intercerebralis of the brain and in intact neuroendocrine complex they reach the CA via nerves. A slow inhibitor, induced by short d, causes reproductive diapause. A fast inhibitor prevents ovarian maturation in starved nondiapausing females. A slow stimulator, induced by feeding under long d, overcomes the fast inhibition of the CA, thereby stimulating vitellogenesis. Food signals are transmitted to the brain via humoral pathways.
Assuntos
Corpora Allata/fisiologia , Heterópteros/fisiologia , Animais , Encéfalo/fisiologia , Feminino , Técnicas In VitroRESUMO
Pilus proteins from Escherichia coli serotypes O1, O2, and O78 pathogenic to poultry were compared with regard to their antigenic relatedness and partial amino acid sequences. Agglutination, immunodiffusion, and immunoblot assays with polyclonal antibodies to these pili showed that these pili not only share some common antigens but also contain antigens unique to each pilus. The partial amino-terminal amino acid sequences support our earlier findings that the pili are different but contain some structural homologies.
Assuntos
Antígenos de Bactérias/análise , Proteínas de Bactérias/análise , Escherichia coli/classificação , Fímbrias Bacterianas/imunologia , Sequência de Aminoácidos , Escherichia coli/imunologia , Fímbrias Bacterianas/análise , Dados de Sequência Molecular , SorotipagemRESUMO
A case history of a patient with metastatic renal cell carcinoma who had been asymptomatic is presented. The report emphasizes the need for consideration of any lesion in the maxillofacial region, as it may be the first definitive sign of a primary cancer.
Assuntos
Carcinoma de Células Renais/secundário , Neoplasias Renais , Neoplasias Mandibulares/secundário , Idoso , Carcinoma de Células Renais/patologia , Humanos , Neoplasias Renais/patologia , Masculino , Neoplasias Mandibulares/patologiaRESUMO
Arterial hypertension and/or tachycardia may alter intracranial pressure in neurosurgical patients. We compared the effects of pancuronium 0.1 mg/kg and pipecuronium 0.1 mg/kg given as i.v. bolus on cerebrospinal fluid (CSF) pressure in 2 groups of 10 patients each scheduled for intracranial surgery in the supine position. Before surgery, no patient presented clinical symptoms of elevated intracranial pressure (ICP). Anesthesia was induced and maintained with fentanyl and midazolam. Ventilation with 50% nitrous oxide in oxygen was adjusted to maintain arterial pCO2 at 30-35 mmHg. After induction of anesthesia, CSF pressure was registered via a lumbar subarachnoid catheter before and 3, 5, 10, and 30 min after pipecuronium or pancuronium administration. Hemodynamics were monitored using radial and pulmonary artery catheters. All variables underwent analyses of variance for repeated measures with p < 0.05 considered significant. Mean CSF pressure decreased insignificantly from 15 +/- 5 mmHg (before injection) to 14 +/- 4 mmHg in patients given pipecuronium and from 13 +/- 4 mmHg to 10 +/- 3 mmHg in the pancuronium group without significant differences between the study groups. Heart rate and arterial pressure increased significantly (p < 0.001) in patients given pancuronium but remained stable after pipecuronium. Onset and duration of neuromuscular blockade were comparable between groups. Based on our results, pipecuronium is a safe alternative to pancuronium during neurosurgical procedures in patients without abnormally high intracranial pressure.
Assuntos
Líquido Cefalorraquidiano/fisiologia , Pressão Intracraniana/efeitos dos fármacos , Fármacos Neuromusculares não Despolarizantes/farmacologia , Pancurônio/farmacologia , Pipecurônio/farmacologia , Adulto , Pressão Sanguínea/efeitos dos fármacos , Encéfalo/cirurgia , Pressão Venosa Central/efeitos dos fármacos , Feminino , Hemodinâmica/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Junção Neuromuscular/efeitos dos fármacos , Pressão Propulsora Pulmonar/efeitos dos fármacosRESUMO
ABSTRACT Two new species of Oxyethira Eaton, 1873 are described: Oxyethira cascadanta sp. n. and Oxyethira quadrilobata sp. n. Description and illustrations of the new species are provided based on specimens collected in Parque Nacional da Serra da Canastra, Minas Gerais State, Southeast Brazil. Both species are assigned to the subgenus Loxotrichia but differ from other species mainly in morphology of the subgenital plate, subgenital processes and inferior appendages. Additionally, we provide an updated checklist of the Oxyethira species from Brazil.
Assuntos
Animais , Masculino , Feminino , Lista de Checagem/normas , Insetos/anatomia & histologia , Insetos/classificação , Especificidade da Espécie , Brasil , Fatores Sexuais , Fatores Etários , Caracteres Sexuais , Estruturas Animais , Distribuição AnimalAssuntos
Hidrolases/metabolismo , Fígado/metabolismo , Receptores de Superfície Celular/metabolismo , Receptores Citoplasmáticos e Nucleares , Animais , Bovinos , Membrana Celular/metabolismo , Radioisótopos do Iodo , Cinética , Receptor IGF Tipo 2 , Receptores de Superfície Celular/isolamento & purificaçãoRESUMO
1. Leucomyosuppressin (LMS) did not inhibit the spontaneous contractions of visceral muscles of the cockroach Leucophaea maderae uniformly as a group but rather showed a selective suppression of activity in the foregut and hindgut. The threshold of LMS inhibition for these organs was 10(-11) M for the foregut and 3 x 10(-11) M for the hindgut. The maximum response for each organ was generally recorded at 2.4 x 10(-8) M. 2. Both the heart and the oviduct were 100-1000 times less sensitive to LMS than either the foregut or the hindgut. Although the responses of the heart to LMS (10(-9) to 10(-8) M) were somewhat inconsistent, the myocardium showed a reduction in either the amplitude or frequency of contractions in 75% of the preparations tested. The oviduct showed the lowest level of responsiveness of all the muscles tested. Even at a concentration of 10(-7) M LMS, the amplitude and frequency of contractions showed no more than a 58% inhibition. 3. Desensitization to LMS was observed in three of the four muscle types tested. The phenomenon occurred in 37% of the foreguts, 34% of the hindguts and 54% of the heart preparations tested. The results of this study show that each visceral muscle type has its own unique response profile to LMS and support the idea that peptides may be multifunctional regulators.
Assuntos
Baratas/fisiologia , Contração Muscular/efeitos dos fármacos , Neuropeptídeos/farmacologia , Animais , Tolerância a Medicamentos , Intestinos/efeitos dos fármacos , Intestinos/fisiologia , Contração Miocárdica/efeitos dos fármacos , Oviductos/efeitos dos fármacos , Oviductos/fisiologiaRESUMO
beta-Lipotrophin (62-77) or Ac-gastrin releasing peptide was incubated with immobilized carboxypeptidase Y or aminopeptidase M. Subsequent aliquots of each incubation mixture were analysed by fast atom bombardment mass spectrometry using a dithiothreitol/dithioerythritol liquid matrix. The use of immobilized enzymes and volatile buffers for exopeptidase digestions enabled rapid and facile separation of enzyme from digestion products. This approach to mass spectral peptide analysis reduced spectral background arising from a glycerol matrix, buffer salts, or enzyme proteins and contaminants, enabling analysis of as little as 200 picomoles of a suitable peptide.