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1.
J Chem Phys ; 156(5): 054301, 2022 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-35135286

RESUMO

The ion-induced fragmentation of CH4 2+ into H+ and CH3 + is studied using a cold target recoil ion momentum spectroscopy in coincidence with the charge state of the post-collision projectile. Using constant velocity Ar9+ and N3+, results from four different datasets are presented, with a selection on the final charge state of the projectile (Ar8+ or Ar7+ and N2+ or N+). Three distinct dissociation pathways (I, II, and III) are observed for each dataset, with the mean kinetic energy release values of around 4.7, 5.8, and 7.9 eV, respectively. The electronic states that are populated correspond to electronic configurations (1t2)-2 and (2a1)-1(1t2)-1 of the methane dication, CH4 2+. The relative branching ratios between the three pathways are discussed as a function of the charge state of the post-collision projectile, and a strong correlation with the specific nature of the ion-molecule interaction is found. The existing ab initio calculations have provided an explanation only for pathway II. In this article, we propose an explanation for pathway III, but pathway I still remains unexplained and requires further theoretical efforts. A discussion of the dependence of dissociation on the mode of excitation is presented.

2.
Insect Mol Biol ; 30(2): 123-137, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33263941

RESUMO

Glycosyltransferases (GTs) catalyse the reaction of glyco-conjugation of various biomolecules by transferring the saccharide moieties from an activated nucleotide sugar to nucleophilic glycosyl acceptor. In insects, GTs show diverse temporal and site-specific expression patterns and thus play significant roles in forming the complex biomolecular structures that are necessary for insect survival, growth and development. Several insects exhibit GT-mediated detoxification as a key defence strategy against plant allelochemicals and xenobiotic compounds, as well as a mechanism for pesticide cross-resistance. Also, these enzymes act as crucial effectors and modulators in various developmental processes of insects such as eye development, UV shielding, cuticle formation, epithelial development and other specialized functions. Furthermore, many of the known insect GTs have been shown to play a fundamental role in other physiological processes like body pigmentation, cuticular tanning, chemosensation and stress response. This review provides a detailed overview of the multifaceted functionality of insect GTs and summarizes numerous case studies associated with it.


Assuntos
Glicosiltransferases , Insetos/enzimologia , Insetos/crescimento & desenvolvimento , Animais , Inativação Metabólica , Insetos/metabolismo
3.
J Phys Chem A ; 123(37): 8001-8008, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31436998

RESUMO

Water ice exists on many objects in space. The most abundant icy species, among them water, are present in the icy satellites of the outer Solar System giant planets. The nuclei of comets, which are mainly composed of water ice, give another example of its abundance. In the interstellar medium (ISM), ice mantles, formed by molecular species sticking on dust grains, consist mainly of water ice. All these objects are exposed to ionizing radiation like ions, UV photons, and electrons. Sputtering of atoms, molecules, ions, and radicals from icy surfaces may populate and maintain exospheres of icy objects in the Solar System. In other respects, ionized hydrides such as OH+, H2O+, and H3O+ have been detected in the gas phase in star-forming regions. Interactions with cosmic rays could be an additional explanation to the current models for the formation of those species. In fact, laboratory simulations showed that the main components of the sputtered ionic species from water ice are oxygen hydrides. In this work, water ice targets were irradiated at several temperatures (10-200 K) by 90 keV O6+ ions, yielding an electronic stopping power of about 12 eV/Å, when the nuclear stopping power is comparable to the electronic stopping power. Sputtering of secondary ions after bombardment of the ice target was analyzed by time-of-flight mass spectrometry (TOF-SIMS). Besides hydrogen ions (H+, H2+, H3+), also O+, O2+, OH+, (H2O)+, and clusters of (H2O)nH+ with n = 1-8 are emitted. Our results show a progressive yield decrease with increasing temperature of all of the detected species. This is related to the structure of the ice: the ionic sputtering yield for crystalline ice is much lower than for an amorphous ice. For instance, amorphous ice at 10 K exhibits a yield of the order of 2 × 10-6 secondary (H2O)nH+ hydride ions/projectile (with n = 1-8). As the temperature is increasing toward the phase transition to crystalline ice, the yields decrease by about one order of magnitude.

4.
Phys Rev Lett ; 118(23): 233402, 2017 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-28644649

RESUMO

Fragmentation of molecular nitrogen dimers (N_{2})_{2} induced by collision with low energy 90 keV Ar^{9+} ions is studied to evidence the influence of a molecular environment on the fragmentation dynamics of N_{2} cations. Following the capture of three or four electrons from the dimer, the three-body N_{2}^{+}+N^{m+}+N^{n+} [with (m,n)=(1,1) or (1, 2)] fragmentation channels provide clean experimental cases where molecular fragmentation may occur in the presence of a neighbor molecular cation. The effect of the environment on the fragmentation dynamics within the dimer is investigated through the comparison of the kinetic energy release (KER) spectra for these three-body channels and for isolated N_{2}^{(m+n)+} monomer cations. The corresponding KER spectra exhibit energy shifts of the order of 10 eV, attributed to the deformation of the N^{m+}+N^{n+} potential energy curves in the presence of the neighboring N_{2}^{+} cation. The KER structures remain unchanged, indicating that the primary collision process is not significantly affected by the presence of a neighbor molecule.

5.
Dis Esophagus ; 30(8): 1-8, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28575249

RESUMO

Luminal distensibility measurement has demonstrated relevance to various disease processes, though its effects on clinical decision-making have been less well understood. This study aims to characterize the clinical impact of impedance planimetry measurement as well as the learning curve associated with its use in the esophagus. A single provider performed distensibility measurement in conjunction with upper endoscopy for a variety of clinical indications with the functional lumen imaging probe (FLIP) over a period of 21 months. Procedural data were prospectively collected and, along with medical records, retrospectively reviewed. Seventy-three procedures (70 patients) underwent esophageal distensibility measurement over the timeline of this study. The most common procedural indications were known or suspected achalasia (32.9%), dysphagia with connective tissue disease (13.7%), eosinophilic esophagitis (12.3%), and dysphagia with prior fundoplication (9.6%). FLIP results independently led to a change in management in 29 (39.7%) cases and supported a change in management in an additional 15 (20.5%) cases. The most common change in management was a new or amended therapeutic procedure (79.5%). Procedural time added by distensibility measurement was greater among earlier cases than among later cases. The median time added overall was 5 minutes and 46 seconds. Procedural time added varied significantly by procedural indication, but changes in management did not. Distensibility measurement added meaningful diagnostic information that impacted therapeutic decision-making in the majority of cases in which it was performed. Procedural time added by this modality is typically modest and decreases with experience.


Assuntos
Doenças do Esôfago/diagnóstico , Esofagoscopia/métodos , Esôfago/patologia , Duração da Cirurgia , Índice de Gravidade de Doença , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Impedância Elétrica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pressão , Estudos Prospectivos , Estudos Retrospectivos , Fatores de Tempo , Adulto Jovem
6.
Waste Manag Res ; 35(6): 563-580, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28566030

RESUMO

In the Bayer process of extraction of alumina from bauxite, the insoluble product generated after bauxite digestion with sodium hydroxide at elevated temperature and pressure is known as 'red mud' or 'bauxite residue'. This alumina refinery waste is highly alkaline in nature with a pH of 10.5-12.5 and is conventionally disposed of in mostly clay-lined land-based impoundments. The alkaline constituents in the red mud impose severe and alarming environmental problems, such as soil and air pollution. Keeping in view sustainable re-vegetation and residue management, neutralization/treatment of red mud using different techniques is the only alternative to make the bauxite residue environmentally benign. Hence, neutralization techniques, such as using mineral acids, acidic waste (pickling liquor waste), coal dust, superphosphate and gypsum as amenders, CO2, sintering with silicate material and seawater for treatment of red mud have been studied in detail. This paper is based upon and emphasizes the experimental work carried out for all the neutralization techniques along with a comprehensive review of each of the processes. The scope, applicability, limitations and feasibility of these processes have been compared exhaustively. Merits and demerits have been discussed using flow diagrams. All the techniques described are technically feasible, wherein findings obtained with seawater neutralization can be set as a benchmark for future work. Further studies should be focused on exploring the economical viability of these processes for better waste management and disposal of red mud.


Assuntos
Óxido de Alumínio , Resíduos Industriais , Solo
7.
Insect Mol Biol ; 25(5): 519-29, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27228010

RESUMO

Lepidoptera is one of the most widespread insect orders and includes several agriculturally important insect species. Ecological success of the lepidopteran insects partly depends on their adaptive chemoreception tactics, which play an important role in the selection of hosts, egg-laying sites and mates. Members of the G-protein coupled receptor family, gustatory receptors (GRs), are an integral part of the Lepidoptera chemosensory machinery. They are expressed in chemosensory neurones and are known to detect different environmental stimuli. Here, we discuss various aspects of the lepidopteran GRs with an emphasis on their roles in different processes such as chemosensation, host selection and adaptation. Phylogenetic analyses have shown that the large diversity of GR genes may have been generated through gene duplication and positive selection events, which also show lineage- and tissue-specific expression. Moreover, lepidopteran GR proteins are diverse and demonstrate broad ligand selectivity for several molecules including sugars, deterrents, salts and CO2 . Binding of ligands to GRs generates multiple downstream changes at the cellular level, which are followed by changes in behaviour. GRs play a critical role in chemosensation and influence the insect's behaviour. Overall, insect GRs are potential targets in the design of effective insect control strategies.


Assuntos
Proteínas de Insetos/genética , Lepidópteros/fisiologia , Receptores Acoplados a Proteínas G/genética , Percepção Gustatória , Adaptação Fisiológica , Animais , Evolução Molecular , Herbivoria , Proteínas de Insetos/metabolismo , Lepidópteros/genética , Receptores Acoplados a Proteínas G/metabolismo
8.
Acta Virol ; 60(3): 217-23, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27640431

RESUMO

A disease of lentil with symptoms of distortion, mottling and chlorosis in the leaves, shortening of internodes and excessive branching was noticed in lentil at Kanpur, India, during 2012-2014. Results of polymerase chain reaction and reverse transcriptase polymerase chain reaction employed to detect suspected RNA and DNA viruses indicated involvement of a geminivirus, which was further characterized by sequencing of full genome amplified by rolling circle amplification. Analysis of full length DNA-A revealed 96.4-96.7% nucleotide similarity with bitter gourd yellow vein virus (BGYVV) isolates and tomato leaf curl New Delhi virus (ToLCNDV) isolate. As per the recent revision of begomovirus species demarcation criteria, if a new virus isolate shares ≥91% nt sequence identity with any other isolate of an existing species, it should be treated as an isolate of that species, even if it is <91% identical to all other isolates from that species. This made BGYVV an isolate of ToLCNDV and resulted in the de-recognizing of the BGGYV. Hence, the present virus has been named as a strain of ToLCNDV and designated as Tomato leaf curl New Delhi virus-Lentil-[India:Kanpur:Lentil:2014] with the acronym as ToLCNDV-Lentil-[IN:Knp:Len:14]. This is the first report of a begomovirus found associated with a disease in lentil from India.


Assuntos
Begomovirus/classificação , Begomovirus/genética , Lens (Planta)/virologia , Doenças das Plantas/virologia , Sequência de Bases , DNA Viral , Índia , Filogenia
9.
Folia Morphol (Warsz) ; 73(4): 527-30, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25448916

RESUMO

Entrapment neuropathy of the supraclavicular nerve is rare and, when it occurs, is usually attributable to branching of the nerve into narrow bony clavicular canals. We describe another mechanism for entrapment of this nerve with the aberrant muscle; supraclavicularis being found during the routine dissection of an embalmed 82-year-old cadaver. Our report details a unique location for this rare muscular variation whereby the muscle fibres originated posteriorly on the medial aspect of the clavicle before forming a muscular arch over the supraclavicular nerve and passing laterally towards the trapezius and acromion. We recommend that in clinical instances of otherwise unexplained unilateral clavicular pain or tenderness, nerve compression from the supraclavicularis muscle must be borne in mind.

10.
Phys Rev Lett ; 111(24): 243201, 2013 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-24483657

RESUMO

We present an experimental determination of the 2p3d(1Po)→1s3d(1De) x-ray line emitted from He-like Si, S, and Cl projectile ions, excited in collisions with thin carbon foils, using a high-resolution bent-crystal spectrometer. A good agreement between the observation and state-of-the-art relativistic calculations using the multiconfiguration Dirac-Fock formalism including the Breit interaction and QED effects implies the dominance of fluorescent decay over the autoionization process for the 2p3d(^{1}P^{o}) state of He-like heavy ions. This is the first observation of the fluorescence-active doubly excited states in He-like Si, S, and Cl ions.

11.
Iran J Vet Res ; 24(4): 345-350, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38799289

RESUMO

Background: Infectious bursal disease (IBD) caused substantial economic loss in central and western India during 2020 and 2021. Aims: The study was conducted to characterize IBD virus (IBDV) from field outbreaks. Methods: The study was conducted on 360 samples from 42 poultry flocks. The samples were subjected to histopathology and molecular detection, followed by phylogenetic typing of the partial VP2 gene. Results: The mortality ranged from 15.25 to 60.18%. The necropsy showed hemorrhages on thigh muscles, mottled spleen, swelling of kidneys and bursae with hemorrhages, and cheesy exudate. Histopathology revealed extensive necrosis and depletion of follicular lymphoid cells within the cortex and medulla, along with widespread hemorrhages, edema, and cystic cavities in the bursa. The field isolates showed cytopathic effects in the seventh passage. The cytopathic effects included swelling, rounding, granulation of cytoplasm around the nucleus, fragmentation of the infected cells, and detachment. The reverse transcription-polymerase chain reaction amplified 664 bp partial VP2 gene. The phylogenetic analysis identified 19 field isolates as very virulent IBDVs (vvIBDVs) and three as classical strains. Conclusion: The results indicated that different vvIBDV strains are involved in disease outbreaks in central and western India.

12.
J Indian Soc Pedod Prev Dent ; 26(4): 168-70, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19008626

RESUMO

Dentigerous cyst is a developmental odontogenic cyst, which apparently develops by accumulation of fluid between the reduced enamel epithelium and the tooth crown of an unerupted tooth. There is usually no pain or discomfort associated with the cyst unless there is acute inflammatory exacerbation. Management of dentigerous cyst in primary dentition needs special consideration regarding the preservation of the developing permanent tooth buds. Here, we report a case of dentigerous cyst in primary dentition in a 10-year-old male patient and its management.


Assuntos
Cisto Dentígero/diagnóstico , Doenças Mandibulares/diagnóstico , Dente Molar/patologia , Dente Decíduo/patologia , Biópsia por Agulha , Criança , Humanos , Masculino , Radiografia Panorâmica , Retalhos Cirúrgicos
13.
J Child Orthop ; 12(6): 566-574, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30607203

RESUMO

PURPOSE: We assessed the pattern of relapse as well as the correlation between the number of casts required for correction and Pirani and Dimeglio scores at presentation, and age at presentation. We hypothesized that the Ponseti method would be effective in treatment of relapsed clubfoot as well. METHODS: We evaluated 115 idiopathic clubfeet in 79 children presenting with relapse following treatment by the Ponseti method. The mean age was 33.8 months with mean follow-up of 24 months. All patients were assessed for various patterns of relapsed deformities. Quantification of deformities was done using the Pirani and Dimeglio scores. All relapsed feet were treated by a repeat Ponseti protocol. RESULTS: Non-compliance to a foot abduction brace was observed to be the main contributing factor in relapse, in 99 clubfeet (86%). Combination of three static deformities (equinus, varus and adduction) together was observed most commonly (38.3% feet). Overall, relapse of equinus deformity was noted most commonly followed by adduction. A painless plantigrade foot was obtained in all 115 feet with a mean of five casts. In all, 71 feet (61.7%) underwent percutaneous tenotomy. A total of 15 feet (13%) required tibialis anterior tendon transfer. Re-relapse rate in group 1 was 21% compared with 12.6% in group 2 and overall 16.5%. CONCLUSION: We conclude that the Ponseti method is effective and the preferred initial treatment modality for relapsed clubfeet. Surgical intervention should be reserved for residual deformity only after a fair trial of Ponseti cast treatment. Regular follow-up and strict adherence to brace protocol may reduce future relapse rates. Further research is required to identify high-risk feet and develop individualized bracing protocol. LEVEL OF EVIDENCE: IV.

14.
Artigo em Inglês | MEDLINE | ID: mdl-29521026

RESUMO

BACKGROUND: Despite potential differences in patient perception of chronic constipation (CC) in geographically and culturally distinct regions, head-to-head studies comparing the clinical profile, constipation severity, impact on quality of life (QOL) and economic impact are lacking. METHODS: We conducted a cross-sectional cohort study of patients presenting with CC to tertiary care centers in the USA and India. Standardized instruments were used to assess constipation subtype, disease severity, disease-specific QOL, somatization, and psychiatric comorbidities. We used multivariable linear regression to determine the predictors of QOL and number of healthcare visits. KEY RESULTS: Sixty-six and 98 patients with CC were enrolled in the USA and India, respectively. Indian patients with CC had significantly more frequent bowel movements/week compared to their USA counterparts (Median 5 vs 3, P < .0001). The proportion of patients with Bristol stool form scale type 1 and 2 was significantly higher in the USA compared to India (65.5% vs 48%, P = .04). Higher depression score (P = .001), more severe constipation symptoms (P = .001) and site of the study being USA (P = .008) independently predicted worse QOL. Indian patients (P < .001) and worse QOL (P = .02) were independent predictors of number of healthcare visits in the last 12 months. CONCLUSIONS AND INFERENCES: Indian patients with CC have more frequent and softer bowel movements compared to those in the USA suggesting significant differences in perception of CC in different geographic and cultural settings. QOL and economic impact related to constipation varies with geographic/cultural setting irrespective of other clinical and psychosomatic features.

15.
Nat Prod Res ; 31(14): 1713-1716, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28278673

RESUMO

Determination of endogenous levels of jasmonic acid (JA) is essential, as it plays a pivotal role in the physiological processes during a plant's life cycle. A high performance thin layer chromatography (HPTLC) method was developed for the detection and quantification of JA in leaf extracts of medicinal plant, Stevia rebaudiana (Bertoni) Bertoni. The separation was achieved using the solvents ethyl acetate-benzene (1:1, v/v) as the mobile phase, followed by scanning and quantification at 295 nm. Densitometric analysis of leaf extract resulted in compact spots for JA at Rf = 0.45 ± 0.02. The linear regression analysis showed good relationship with r value. The recovery rate of JA indicated good reproducibility and repeatability of the assay. The statistical analysis proved the reproducibility of the method; therefore, it can be employed for routine quantification of JA in different tissue samples of S. rebaudiana and may also be extrapolated to other biological samples.


Assuntos
Ciclopentanos/análise , Oxilipinas/análise , Stevia/química , Acetatos , Benzeno , Cromatografia em Camada Fina/métodos , Ciclopentanos/normas , Oxilipinas/normas , Extratos Vegetais/análise , Folhas de Planta/química , Reprodutibilidade dos Testes
16.
Int J Inj Contr Saf Promot ; 13(2): 128-30, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16707352

RESUMO

Road traffic injuries and deaths caused by motor vehicles is a growing public health problem all over the world. Inter-country or regional differences in the pattern of injury by road users have significant implications in determining prevention policies. The present study was conducted to evaluate the pattern of injuries in 217 hospitalized trauma patients admitted during 1 year, 2003. The majority of the injuries (54%) involved motorcycles. The highest incidence amongst the male population was in the age group of 16 - 30 years. Head and face injuries and injuries to the lower limbs comprised 58.1% and 50.7% of all injuries respectively. The bones of the lower limbs were most commonly fractured. To conclude, the traffic casualties of motorcyclists and pedestrians are considered a major problem and the preventive measures to reduce these transport-related injuries are discussed in this study.


Assuntos
Acidentes de Trânsito/estatística & dados numéricos , Ferimentos e Lesões/epidemiologia , Acidentes de Trânsito/prevenção & controle , Adolescente , Adulto , Distribuição por Idade , Criança , Pré-Escolar , Serviço Hospitalar de Emergência , Feminino , Hospitais de Ensino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Nepal/epidemiologia , Distribuição por Sexo , Índices de Gravidade do Trauma , Ferimentos e Lesões/prevenção & controle
17.
J Indian Soc Pedod Prev Dent ; 24(3): 152-4, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17065784

RESUMO

Dilaceration of permanent successors is one of the most common complications of trauma to the deciduous teeth. It is advisable to keep these patients under observation post-trauma and to consult an orthodontist at an early stage to prevent unfavorable sequelae. Presented here is a typical case of dilaceration.


Assuntos
Incisivo/anormalidades , Dente não Erupcionado/cirurgia , Criança , Feminino , Humanos , Maxila , Anormalidades Dentárias/etiologia , Anormalidades Dentárias/cirurgia , Extração Dentária , Traumatismos Dentários/complicações , Raiz Dentária/anormalidades , Dente Decíduo/lesões , Dente não Erupcionado/etiologia
18.
J Med Chem ; 31(6): 1261-4, 1988 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-3373496

RESUMO

The synthesis of C-nor-9,11-secoestradiol (4) has been achieved from 17 beta-acetoxy-11-chloro-3-methoxy-C-nor-9,11-secoestra-1,3,5(10)-tr ien-9-one (1) through a sequence of reactions without affecting the stereochemistry of estradiol-17 beta. Removal of the 9-keto function of 1 by hydrogenolysis and its subsequent treatment with Na/NH3 gives C-nor-9,11-secoestradiol 3-(methyl ether) (3), which has been demethylated under alkaline conditions to furnish C-nor-9,11-secoestradiol (4). Pyridinium chlorochromate oxidation of 3 gives the corresponding 17-ketone 6. Jones' oxidation of 4 to the ketone 5 and reaction of 5 and 6 with lithium acetylide gives corresponding 17 alpha-ethynyl derivatives 7 and 8. Relative binding affinity to estradiol-17 beta receptors and uterotropic, antiuterotrophic, and antiimplantation activities of compounds 3-8 have been studied. The effect of conformational flexibility on ligand-receptor interaction of these compounds is discussed.


Assuntos
Estranos/síntese química , Estrogênios/síntese química , Fertilidade/efeitos dos fármacos , Secoesteroides/síntese química , Animais , Estranos/farmacologia , Estrogênios/farmacologia , Feminino , Conformação Molecular , Ratos , Secoesteroides/farmacologia , Relação Estrutura-Atividade , Útero/efeitos dos fármacos
19.
J Med Chem ; 32(10): 2297-300, 1989 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2795601

RESUMO

A number of 2,6-dimethyl-3,5-bis(methoxycarbonyl)-4-substituted-1,4- dihydropyridines were synthesized and evaluated for pregnancy-interceptive activity in mated hamsters. Out of 24 compounds, 12, 15, 21, 22, 28, and 34 caused a marked reduction in the number of implantations when administered on days 3-8 postcoitum. In an in vitro competition assay, none of the compounds exhibited noticeable binding affinity for uterine progesterone receptors. The results reported here have helped to identify new leads for developing pregnancy-interceptive agents and the active compounds do not seem to elicit their interceptive effect through receptor-mediated inhibition of progesterone action in hamster uterus.


Assuntos
Abortivos/síntese química , Di-Hidropiridinas/síntese química , Receptores de Progesterona/efeitos dos fármacos , Útero/metabolismo , Animais , Cricetinae , Citosol/metabolismo , Di-Hidropiridinas/farmacologia , Feminino , Mesocricetus , Estrutura Molecular , Gravidez , Progesterona/metabolismo , Coelhos , Receptores de Progesterona/metabolismo , Valores de Referência , Relação Estrutura-Atividade
20.
J Thorac Cardiovasc Surg ; 110(6): 1708-20; discussion 1720-4, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8523884

RESUMO

Replacement valve endocarditis occurred in 3.7% of 2443 patients who underwent primary or redo aortic valve replacements at The Prince Charles Hospital between December 31, 1969 and January 1, 1992, based on a cross-sectional follow-up in 1992 which was 98.8% complete. Because some patients had re-replacements during the study period, a total of 2686 operations were considered for analysis. A variety of replacement devices were used, including 571 allografts (21%), 1152 xenografts (43%), and 880 mechanical valves (36%). Insertion of an allograft valve resulted in a constant risk of endocarditis which, by multivariable hazard function analysis, negated the effect of any early-phase factors (p < 0.0001). With other replacement devices, the risk of infection peaked early after operation (9 weeks) and then gave way to a constant risk. Compared with the risk associated with allograft valves, constant risk was higher when the replacement device was a Carpentier-Edwards xenograft (n = 1021, p = 0.02) and lower when a St. Jude Medical mechanical valve was used (n = 505, p = 0.05). In nonallograft recipients, the presence of active preoperative endocarditis (p < 0.0001) or a concomitant synthetic synthetic aortic root replacement (p = 0.0006) increased the magnitude of the early peaking risk. Regardless of replacement device, constant risk was increased in patients with renal dysfunction (p = 0.01), in younger patients 0.04). When preoperative endocarditis was caused by Staphylococcus aureus, culture-positive postoperative wound infection was associated with increased risk of replacement valve infection (p < 0.001) and when it occurred, the same organism was usually responsible (86%). Identification of patients at increased risk for replacement valve infection may lead to reduced morbidity through strategies such as selective use of replacement devices and antimicrobial prophylaxis.


Assuntos
Endocardite Bacteriana/epidemiologia , Próteses Valvulares Cardíacas , Infecções Relacionadas à Prótese/epidemiologia , Valva Aórtica , Estudos Transversais , Endocardite Bacteriana/etiologia , Endocardite Bacteriana/microbiologia , Feminino , Seguimentos , Próteses Valvulares Cardíacas/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Morbidade , Prevalência , Desenho de Prótese , Infecções Relacionadas à Prótese/microbiologia , Reoperação , Fatores de Risco , Infecções Estafilocócicas/epidemiologia , Infecções Estreptocócicas/epidemiologia , Infecção da Ferida Cirúrgica/epidemiologia , Infecção da Ferida Cirúrgica/microbiologia , Fatores de Tempo
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