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1.
J Chem Phys ; 158(2): 024305, 2023 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-36641418

RESUMO

Bands of the g 6Φ-X 4Δ, g 6Φ-A 4Π, g 6Φ-a 6Δ, and g 6Φ-b 6Π electronic transitions of iron monodeuteride (FeD) have been measured in laser excitation and in dispersed fluorescence. The molecules were produced both in a cold supersonic molecular jet source and in a chemical reaction between iron pentacarbonyl [Fe(CO5)] and a microwave discharge of argon and hydrogen gases. Dispersed fluorescence from the latter source was detected at high resolution with a Fourier transform spectrometer, yielding a large number of the transitions observed. The data reveal that FeD experiences strong interstate couplings that compromise fitting of the data with traditional Hamiltonians but that the problem is less severe than in corresponding spectra of FeH. This work greatly expands the available data on FeD, which were previously characterized only through the F 4Δ-X 4Δ spectrum and pure rotational data in the ground state.


Assuntos
Eletrônica , Gases , Argônio , Hidrogênio , Análise Espectral
2.
Eur J Obstet Gynecol Reprod Biol ; 234: 117-119, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30684876

RESUMO

OBJECTIVE: To determine whether post-pregnancy human chorionic gonadotrophin screening after previous hydatidiform mole identifies patients with recurrent gestational trophoblastic disease. STUDY DESIGN: A retrospective evaluation of 9315 patients who underwent post-pregnancy screening from 2000 to 2009, as part of the National Gestational Trophoblastic Disease Service in the UK. RESULTS: Patients with previous hydatidiform mole, who had human chorionic gonadotrophin screening after one or more subsequent pregnancies, were identified (n = 9315). Of these, 8630 patients had an initial hydatidiform mole that did not require chemotherapy. In 12,329 subsequent pregnancy events, screening with human chorionic gonadotrophin identified 3 cases of gestational trophoblastic neoplasm. The remaining 685 patients developed gestational trophoblastic neoplasm, following their initial hydatidiform mole and required chemotherapy. In this group there were 1012 further pregnancy events, human chorionic gonadotrophin screening identified 3 patients with gestational trophoblastic neoplasm. The overall recurrence rate was 6 in 13,341 events (risk 1: 2227). The rate was 3 in 12,329 (risk 1:4110) for HM that did not require chemotherapy and 3 in 1012 (1:337) for previously treated gestational trophoblastic neoplasm. All 6 patients with recurrent disease were successfully treated with chemotherapy. CONCLUSION: Routine post-pregnancy human chorionic gonadotrophin screening may be safely discontinued in patients with one previous uncomplicated hydatidiform mole.


Assuntos
Gonadotropina Coriônica/sangue , Doença Trofoblástica Gestacional/diagnóstico , Mola Hidatiforme/sangue , Recidiva Local de Neoplasia/diagnóstico , Neoplasias Uterinas/sangue , Adulto , Feminino , Doença Trofoblástica Gestacional/etiologia , Humanos , Mola Hidatiforme/complicações , Recidiva Local de Neoplasia/etiologia , Período Pós-Parto/sangue , Gravidez , Estudos Retrospectivos , Fatores de Risco , Neoplasias Uterinas/complicações
3.
Artigo em Inglês | MEDLINE | ID: mdl-28960795

RESUMO

BACKGROUND: Nausea is a common prodromal symptom of neurally mediated syncope, but the biological factors linking nausea with syncope have not been studied. We aimed to characterize nausea during tilt-induced syncope by exploring related changes in gastric myoelectrical activity and plasma epinephrine, norepinephrine, and vasopressin concentrations across study phases of recumbency, tilt, syncope, and recovery. METHODS: Electrogastrographic and plasma hormone changes were compared between patients with tilt-induced syncope and nausea (n = 18) and control subjects (n = 6) without symptoms or hemodynamic changes during tilt-table testing. KEY RESULTS: Over a 4-minute period preceding syncope, sequential electrogastrography epochs demonstrated an increase over time in bradygastria (P = .003) and tachygastria (P = .014) power ratios, while the dominant frequency (P < .001) and the percent normogastria (P = .004) decreased. Syncope led to significant differences between cases and controls in electrogastrographic power ratios in each frequency range: bradygastria (P = .001), tachygastria (P = .005), and normogastria (P = .03). Nausea always followed electrogastrographic changes, and nausea resolution always preceded electrogastrographic normalization. Plasma vasopressin (676.5 ± 122.8 vs 91.2 ± 15.3 pg/mL, P = .012) and epinephrine (434 ± 91.3 vs 48.7 ± 2.5 pg/mL, P = .03), but not norepinephrine (P > .05), also differed with syncope between cases and controls. CONCLUSIONS AND INFERENCES: The nausea related to tilt-induced syncope is temporally associated with changes in gastric myoelectrical activity and increases in plasma vasopressin and epinephrine. The biological mechanisms that induce syncope are physiologically distinct from other experimental models of nausea such as illusory self-motion, yet nausea with syncope appears to have similarly associated electrogastrographic and hormone changes. Thus, tilt-induced syncope could serve as an informative experimental model for nausea research.


Assuntos
Náusea/metabolismo , Náusea/fisiopatologia , Estômago/fisiopatologia , Síncope/metabolismo , Síncope/fisiopatologia , Adolescente , Eletromiografia , Epinefrina/sangue , Feminino , Humanos , Náusea/complicações , Norepinefrina/sangue , Síncope/complicações , Teste da Mesa Inclinada , Vasopressinas/sangue
4.
J Clin Endocrinol Metab ; 99(12): E2652-60, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25127195

RESUMO

CONTEXT: Kisspeptin is a recently identified hormone encoded by the KISS1 gene, playing a critical role in human reproduction. Plasma kisspeptin levels rise dramatically during normal pregnancy due to placental synthesis, which implicates it as a potential tool for assessing risks of pregnancy complications. No previous prospective study has investigated the association between plasma kisspeptin and risk of miscarriage. OBJECTIVE: The objective of the study was to determine whether a single plasma kisspeptin or serum human chorionic gonadotropin (hCG) measurement in asymptomatic women attending their booking antenatal visit is associated with miscarriage. DESIGN: This was a prospective cohort study. SETTING: The study was conducted at a tertiary obstetric center. PARTICIPANTS: A total of 993 asymptomatic pregnant women with a gestation of 6 weeks or longer attending routine antenatal booking visit were recruited between January 2010 and December 2012. MAIN OUTCOME MEASURES: Plasma kisspeptin and serum hCG were measured during the antenatal booking visit. Pregnancy outcome was recorded prospectively. RESULTS: Plasma kisspeptin correlated with gestation (r(2) = 0.57; P < .0001). Gestational age-corrected (multiples of median) plasma kisspeptin was 60.4% lower (P < .001), and multiples of median-hCG was 36.1% lower (P < .001) in women later diagnosed with miscarriage compared with women without miscarriage. Increased plasma kisspeptin was associated with reduced miscarriage risk, even after adjusting for age, body mass index, gestational age, smoking, and blood pressure [odds ratio 0.13 (95% confidence interval 0.08-0.22), P = .0001]. Kisspeptin had a higher diagnostic performance for miscarriage than hCG (receiver-operator characteristic-area under the curve 0.899 ± 0.025 plasma kisspeptin; 0.775 ± 0.040, serum hCG, P < .01 vs plasma kisspeptin). CONCLUSION: Our data suggest for the first time that a single plasma kisspeptin measurement taken during the antenatal booking visit provides a potential novel marker for identifying asymptomatic pregnant women at a gestation of 6 weeks or greater at increased risk of miscarriage.


Assuntos
Aborto Espontâneo/sangue , Kisspeptinas/sangue , Cuidado Pré-Natal , Aborto Espontâneo/epidemiologia , Adulto , Gonadotropina Coriônica/sangue , Estudos de Coortes , Feminino , Idade Gestacional , Humanos , Gravidez , Primeiro Trimestre da Gravidez , Estudos Prospectivos , Risco
5.
IET Syst Biol ; 5(1): 50, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21261402

RESUMO

Classical sensitivity analysis is routinely used to identify points of fragility or robustness in biochemical networks. However, intracellular systems often contain components that number in the thousands to tens or less and consequently motivate a stochastic treatment. Although methodologies exist to quantify sensitivities in stochastic models, they differ substantially from those used in deterministic regimes. Therefore it is not possible to tell whether observed differences in sensitivity measured in deterministic and stochastic elaborations of the same network are the result of methodology or model form. The authors introduce here a distribution-based methodology to measure sensitivity that is equally applicable in both regimes, and demonstrate its use and applicability on a sophisticated mathematical model of the mouse circadian clock that is available in both deterministic and stochastic variants. The authors use the method to produce sensitivity measurements on both variants. They note that the rank-order sensitivity of the clock to parametric perturbations is extremely well conserved across several orders of magnitude. The data show that the clock is fragile to perturbations in parameters common to the cellular machinery ('global' parameters) and robust to perturbations in parameters that are clock-specific ('local' parameters). The sensitivity measure can be used to reduce the model from its original 73 ordinary differential equations (ODEs) to 18 ODEs and to predict the degree to which parametric perturbation can distort the phase response curve of the clock. Finally, the method is employed to evaluate the effect of transcriptional and translational noise on clock function. [Includes supplementary material].


Assuntos
Modelos Biológicos , Processos Estocásticos , Animais , Modelos Teóricos
6.
Knee ; 14(5): 375-8, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17662607

RESUMO

The two most common skin incisions in total knee arthroplasty (TKA) are the medial parapatellar and midline. As the medial parapatellar incision is predominantly parallel to the Langer's lines of the knee, this may give a better cosmetic appearance. The aim of this study was to assess patient satisfaction of the surgical scar and resulting hypoaesthesia following TKA. Two groups of patients who underwent primary TKA were reviewed. Group 1 consisted of 91 patients who underwent primary TKA using a medial parapatellar incision and trivector arthrotomy with a mean follow up of 2.8 years. Group 2 consisted of 76 patients who underwent primary TKA using a midline incision and medial parapatellar arthrotomy with a mean follow up of 2.7 years. The scars were assessed using the validated Manchester Scar Proforma (MSP) and Visual Analogue Scales (VAS). The resulting hypoaesthesia was assessed using VAS. The mean MSP for Group 1 and Group 2 was 11.7 and 11.9 respectively. The mean area of hypoaesthesia for Group 1 and Group 2 was 28.9 cm(2) and 23.8 cm(2) respectively. There was no statistical significance in any of the parameters measured. The mean length of the incision scar was 19.5 cm for Group 1 and 19.4 cm for Group 2. Both produced equal and excellent cosmetic results. Patients in both groups had hypoaesthesia around the knee at 7 years following their TKA. Hypoaesthesia was not found to be of significant concern to patients. This information may be useful when consenting patients for TKA.


Assuntos
Artroplastia do Joelho/métodos , Cicatriz/complicações , Hipestesia/etiologia , Idoso , Cicatriz/patologia , Estética , Seguimentos , Humanos , Medição da Dor , Satisfação do Paciente
7.
J Urol ; 168(3): 1235-9, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12187274

RESUMO

PURPOSE: We compared the potency of adenosine triphosphate (ATP) and its nonhydrolyzable analogue alpha,beta-methylene ATP for generating contractions in human detrusor smooth muscle from patients with a stable, unstable and obstructed bladders. The different ATP potencies were compared with the ecto-adenosine triphosphatase (ATPase) of these samples. MATERIALS AND METHODS: Contractile experiments were done in vitro by superfusing samples with purines and dose-response curves were generated. Ecto-ATPase activity was measured from the rate of ATP hydrolysis sensitive to the ecto-ATPase inhibitor ARL 67156 with a luciferin-luciferase assay. RESULTS: ATP generated contractions with a mean EC50 of 933 microM. in tissue from stable bladders and was significantly more potent in tissue from unstable and obstructed bladders (EC50 141 and 172 microM., respectively). alpha,beta-methylene ATP was more potent in tissue from stable and unstable bladders (mean combined EC50 3 microM.). In guinea pig detrusor the mean EC50 for ATP and alpha,beta-methylene ATP was 138 and 5.5 microM., respectively. Mean total ATPase activity in unstable bladder biopsies plus or minus standard deviation was about 50% of that in stable bladder biopsies (2.54 +/- 1.50 versus 1.37 +/- 0.46 nmol. per second per mg. protein ). The ARL 67156 sensitive fraction was also significantly less in samples from unstable compared with stable bladders (mean 0.94 +/- 0.41 versus 0.36 +/- 0.26 nmol. per second mg. protein ). CONCLUSIONS: The greater potency of ATP for generating contractions in detrusor from unstable bladders may be due to reduced extracellular hydrolysis, allowing purine greater access to detrusor smooth muscle. This finding may explain atropine resistant purine based contractions in detrusor from unstable bladders.


Assuntos
Adenosina Trifosfatases/metabolismo , Trifosfato de Adenosina/farmacologia , Contração Muscular/efeitos dos fármacos , Obstrução do Colo da Bexiga Urinária/fisiopatologia , Bexiga Urinaria Neurogênica/fisiopatologia , Bexiga Urinária/efeitos dos fármacos , Trifosfato de Adenosina/análogos & derivados , Animais , Relação Dose-Resposta a Droga , Feminino , Cobaias , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Músculo Liso/efeitos dos fármacos , Músculo Liso/enzimologia , Músculo Liso/fisiologia , Bexiga Urinária/enzimologia , Bexiga Urinária/fisiologia , Obstrução do Colo da Bexiga Urinária/enzimologia , Bexiga Urinaria Neurogênica/enzimologia
9.
Eur J Endocrinol ; 138(6): 659-66, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9678533

RESUMO

OBJECTIVE: Elderly women with proximal femur fracture show a prolonged increase in plasma cortisol, which could have undesirable catabolic effects. Suppression of cortisol by dexamethasone is impaired, suggesting resistance to glucocorticoid effects at feedback inhibitory sites. We therefore wished to find out whether peripheral glucocorticoid sensitivity is normal. DESIGN: Peripheral blood mononuclear leucocytes were used as a model tissue. Blood samples were taken from elderly women about 2 weeks after hip fracture and from elderly control women. Each patient was then given 1 mg dexamethasone at 2300 h followed by further sampling at 0800 and 1600 h the next day. METHODS: Glucocorticoid-receptor binding parameters were measured by incubating whole cells with [3H]dexamethasone for 2 h at 37 degrees C. Inhibition of cell proliferation by dexamethasone was assessed by addition of [3H]thymidine to cells cultured for 65 h with concanavalin A. Cortisol and dexamethasone concentrations were measured in the dexamethasone suppression test. RESULTS: As expected, the hip-fracture patients had raised morning cortisol concentrations and impaired suppression by dexamethasone. The cells of the patients had similar numbers of glucocorticoid receptors to those of the control subjects but higher values for Kd (i.e. a lower binding affinity). The cells of the patients incorporated less [3H]thymidine than the control cells in the absence of dexamethasone. The percentage inhibition by a saturating concentration of dexamethasone was unchanged but the concentration giving half-maximal inhibition was decreased (sensitivity was increased) at the higher of the two concanavalin A concentrations used. CONCLUSIONS: These experiments in mononuclear leucocytes give no evidence of peripheral resistance to glucocorticoids in hip-fracture patients with impaired suppression of cortisol by dexamethasone.


Assuntos
Dexametasona , Glucocorticoides , Fraturas do Quadril/tratamento farmacológico , Hidrocortisona/sangue , Leucócitos Mononucleares/efeitos dos fármacos , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Células Cultivadas , Concanavalina A/antagonistas & inibidores , Depressão Química , Retroalimentação , Feminino , Fraturas do Quadril/sangue , Humanos , Pessoa de Meia-Idade , Mitógenos/antagonistas & inibidores , Estatísticas não Paramétricas
10.
Prehosp Disaster Med ; 12(4): 313-7, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-10179213

RESUMO

Obtaining a prehospital 12-lead electrocardiogram (ECG) diagnostic of acute myocardial injury has been demonstrated to hasten the administration of thrombolytic agents in the emergency department. This case demonstrates that a prehospital electrocardiogram diagnostic of acute anterior wall infarction can become non-diagnostic following routine administration of oxygen, nitroglycerin, and morphine by paramedics. Although this phenomenon has been observed in the in-hospital setting, it has not been reported in patients with a prehospital ECG.


Assuntos
Eletrocardiografia , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/fisiopatologia , Adulto , Diagnóstico Diferencial , Serviços Médicos de Emergência , Feminino , Humanos , Sensibilidade e Especificidade , Washington
11.
Ann Vasc Surg ; 9(2): 140-5, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7540408

RESUMO

To test the thrombosis resistance of a vascular prosthesis coated with antithrombogenic agents, we evaluated a small vessel prosthesis of expanded polytetrafluoroethylene (ePTFE) implanted in the rat aorta and removed 1 week following surgery. Control grafts consisted of 1 mm internal diameter ePTFE. Experimental grafts consisted of 1 mm internal diameter ePTFE noncovalently bonded to tissue plasminogen activator (tPA) and iloprost using the surfactant tridodecylmethylammonium chloride. After 1 week the grafts were harvested, patency was determined, and histologic specimens were prepared for electron microscopy. Six of 10 control grafts were thrombosed, whereas 9 of 10 tPA-iloprost-bonded grafts were patent (p < 0.03). Of concern, there was an unexpectedly high mortality rate in the tPA-iloprost group compared to the control group among animals that died before completion of the study. Evaluation of the safety of these drugs must, therefore, be an early component of future experiments. Nevertheless, these studies indicate that a small vessel prosthesis bonded to tPA and iloprost may ameliorate some of the complications associated with early graft failure.


Assuntos
Prótese Vascular , Iloprosta/farmacologia , Ativador de Plasminogênio Tecidual/farmacologia , Grau de Desobstrução Vascular , Animais , Aorta Abdominal/patologia , Aorta Abdominal/cirurgia , Oclusão de Enxerto Vascular/prevenção & controle , Masculino , Microscopia Eletrônica de Transmissão e Varredura , Politetrafluoretileno , Falha de Prótese , Compostos de Amônio Quaternário/farmacologia , Ratos , Ratos Sprague-Dawley , Tensoativos/farmacologia , Trombose/prevenção & controle
12.
Am J Emerg Med ; 10(6): 593-4, 1992 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1388392

RESUMO

The year 1987 witnessed the "velvet revolution" of Vaclav Havel and the beginning of democratic reform in Czechoslovakia. As the country struggles to build a market-based economy, it maintains a well-developed socialist system of health care that is patterned after the former Soviet system and is free to all (Am J Emerg Med 1984; 2:455-456). Formal private medical practice does not exist. Non-emergency care is provided by multispecialty, primary-care oriented clinics (polyklinka) where after-hours visits are possible due to the presence of on-call physicians. In small towns such an on-call doctor would be a general practitioner, but in large cities an internist, pediatrician, and surgeon might all be available.


Assuntos
Serviços Médicos de Emergência , Tchecoslováquia , Educação Médica/organização & administração , Serviços Médicos de Emergência/organização & administração , Serviços Médicos de Emergência/tendências , Medicina de Emergência/tendências , Humanos , Transporte de Pacientes
13.
J Hand Surg Br ; 17(3): 321-31, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1624867

RESUMO

The "S" Quattro has shown its value in the management of displaced comminuted intra-articular phalangeal fracture dislocations. Since then the system has been used as a dynamic flexible external fixator in the treatment of five maluniting phalangeal fractures, five comminuted condylar and four severe compound fractures. These challenging fractures have been dealt with by easy operations, taking full advantage of the versatility of the "S" Quattro to achieve good results.


Assuntos
Fixadores Externos , Traumatismos dos Dedos/cirurgia , Fraturas Ósseas/cirurgia , Adulto , Feminino , Traumatismos dos Dedos/diagnóstico por imagem , Articulações dos Dedos/diagnóstico por imagem , Fraturas Ósseas/diagnóstico por imagem , Humanos , Masculino , Radiografia
16.
J Assoc Off Anal Chem ; 74(6): 929-32, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1757416

RESUMO

Percentage ingredient labeling has been proposed for baby foods. We determined whether or not the potassium content of baby foods could be used to verify the quantity of fruit when the characterizing ingredients were apricots or bananas, fruits rich in potassium. Official values for potassium in fruit (USDA Handbook No. 8-9) did not agree well with actual analyses. The potassium levels of products of known composition were accurately predicted from analyses of the actual ingredients used to make the foods. For banana-containing monofruit products of variable or unknown composition, potassium analysis led to fruit level estimates consistent with either the known composition or the label declaration. For products of unknown composition made with apricot concentrate, however, potassium analysis led to fruit level estimates lower than the probable fruit content. The quantity of fruit in baby foods made with potassium-rich fruits can be estimated from the potassium content if the potassium value for the fruit is representative of the actual ingredients used to make the product. If potassium analysis is to be used to verify compliance with percentage ingredient labeling, there must be statutory specification of the single-strength fruit level for fruit reconstituted from concentrate.


Assuntos
Frutas/química , Alimentos Infantis/análise , Potássio/análise , Rotulagem de Alimentos/normas , Humanos , Lactente , Controle de Qualidade
17.
Am J Emerg Med ; 9(1): 52-3, 1991 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1985652

RESUMO

Acute encephalitis is an unusual manifestation of cat-scratch disease. The authors present the case of a 27-year-old man who exhibited the acute onset of encephalitis manifested by violent behavior and confusion. The diagnosis of drug abuse was presumed initially, but a careful examination revealed the true cause to be cat-scratch disease. Emergency physicians are frequently faced with the challenging task of evaluating confused and combative patients. This case demonstrates the importance of a complete physical examination and a thorough laboratory evaluation.


Assuntos
Agressão , Doença da Arranhadura de Gato/diagnóstico , Adulto , Doença da Arranhadura de Gato/complicações , Confusão , Diagnóstico Diferencial , Encefalite/diagnóstico , Encefalite/etiologia , Humanos , Masculino , Transtornos Relacionados ao Uso de Substâncias/diagnóstico
18.
Cardiovasc Intervent Radiol ; 13(2): 102-6, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2117488

RESUMO

A prospective controlled trial of the effectiveness of a cefoxitin-bonded nephrostomy catheter was undertaken to determine the effectiveness of an antibiotic bonded catheter in decreasing the infectious complications of percutaneous nephrostomy. The study concludes that bonding of the antibiotic cefoxitin to percutaneous nephrostomy catheters did not influence the incidence of bacteriuria or urinary tract infection. In addition, observations on the overall incidence of complications from percutaneous nephrostomy are made.


Assuntos
Cefoxitina/uso terapêutico , Nefrostomia Percutânea/efeitos adversos , Cateterismo Urinário/efeitos adversos , Infecções Urinárias/prevenção & controle , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Radioisótopos de Carbono , Criança , Ensaios Clínicos como Assunto , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Infecções Urinárias/etiologia , Infecções Urinárias/microbiologia
19.
Perit Dial Int ; 10(1): 57-9, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2085584

RESUMO

Previous in vitro, in vivo, and a preliminary clinical report have demonstrated efficacy of noncovalently bonding antibiotics to the surface of continuous ambulatory peritoneal dialysis (CAPD) catheters in decreasing infectious complications. A larger prospective randomized clinical trial was completed. Eighty-six patients with chronic renal failure were enrolled in the study and randomized to receive either a surfactant treated or untreated control catheter. All catheters were soaked in cefoxitin at the time of insertion. Groups were comparable in terms of pre-existing illnesses, age, and gender. No differences were shown in the incidence of catheter-tract infections, peritonitis or mechanical complications. There was also no differences in microbiologic culture results. Therefore, it is concluded that this clinical trial did not demonstrate a reduction in catheter-related infectious complications by antibiotic bonding.


Assuntos
Infecções Bacterianas/prevenção & controle , Cateteres de Demora , Cefoxitina , Diálise Peritoneal Ambulatorial Contínua/instrumentação , Peritonite/prevenção & controle , Compostos de Amônio Quaternário , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Diálise Peritoneal Ambulatorial Contínua/efeitos adversos , Estudos Prospectivos , Tensoativos
20.
Thromb Haemost ; 61(1): 131-6, 1989 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-2501890

RESUMO

Tissue plasminogen activator labeled with radioactive iodine (125I-tPA) was immobilized on vascular prostheses chemically modified with a thin coating of water-insoluble surfactant, tridodecylmethylammonium chloride (TDMAC). Surfactant-treated Dacron, polytetrafluoroethylene (PTFE), silastic, polyethylene and polyurethane bound appreciable amounts of 125I-tPA (5-30 micrograms 125I-tPA/cm2). Upon exposure to human plasma, the amount of 125I-tPA bound to the surface shows an initial drop during the first hour of incubation, followed by a slower, roughly exponential release with a t 1/2 of approximately 75 hours. Prostheses containing bound tPA show fibrinolytic activity as measured both by lysis of clots formed in vitro, and by hydrolysis of a synthetic polypeptide substrate. Prior to incubation in plasma, tPA bound to a polymer surface has an enzymic activity similar, if not identical to that of the native enzyme in buffered solution. However, exposure to plasma causes a decrease in the fibrinolytic activity of both bound tPA and enzyme released from the surface of the polymer. These data demonstrate that surfactant-treated prostheses can bind tPA, and that these chemically modified devices can act as a slow-release drug delivery system with the potential for reducing prosthesis-induced thromboembolism.


Assuntos
Prótese Vascular , Ativador de Plasminogênio Tecidual/metabolismo , Antígenos/análise , Compostos Cromogênicos , Humanos , Oligopeptídeos , Polímeros , Compostos de Amônio Quaternário/farmacologia , Propriedades de Superfície , Tensoativos/farmacologia , Tromboelastografia , Ativador de Plasminogênio Tecidual/imunologia
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