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1.
Braz. j. biol ; 842024.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1469287

RESUMO

Abstract This study aimed to evaluate whether skeletal development of the Pantanal Caiman (Caiman yacare) is similarly influenced by temperature variation and controlled increases in embryo motility. All eggs were incubated at 90% humidity and 29 °C for the first 45 days. Thereafter, the incubation temperature was either maintained at 29 °C and embryos were treated with 4-aminopyridine (4-AP) on days 46, 47, 48, and 49 (Group I, 29 °C 4-AP, n = 15); maintained at 29 °C (n = 14; Group II); or at 33 °C (n = 14, Group III). Embryonic movement was measured using an Egg Buddy® digital monitor on days 30, 35, 42, 49, 56, and 60, at which point embryos were euthanized and samples were collected for analysis. No differences were observed between groups with varying incubation temperatures. In contrast, embryonic motility was greater in embryos treated with 4-AP (P 0.001) on day 49, and this was associated with higher proportions of snout-vent and hand lengths. This study demonstrates for the first time that pharmacologically induced increases in embryo motility result in phenotypic changes to the proportion of elements during prenatal ontogeny, thereby effectively altering the adaptation of the species to specific environments.


Resumo Este estudo objetivou avaliar os efeitos da temperatura e motilidade embrionária sobre o desenvolvimento esquelético de jacaré-do-pantanal (Caiman yacare). Os ovos foram incubados com 90% de umidade e empregou-se a temperatura de 29°C por 45 dias. Após, para a incubação do Grupo I a temperatura continuou em 29°C, mas associou-se à injeção de 4-aminopiridina (29°C-4AP, n = 15) aplicada nos dias 46, 47, 48 e 49, do Grupo II permaneceu em 29°C (n = 14) e do Grupo III elevou-se para 33°C (n = 14). A movimentação foi mensurada através do monitor digital Egg Buddy® nos dias 30, 35, 42, 49, 56 e 60 dias. Aos 60 dias, os embriões foram eutanasiados e coletadas amostras embrionárias. Na análise estatística não foram observadas diferenças entre os grupos para o fator temperatura sobre a motilidade embrionária no desenvolvimento esquelético. Em contraste, a motilidade evidenciou diferença estatística no dia 49 para o Grupo I (P 0,001) e apresentou maiores proporções de nariz e mão. Esses dados demonstraram pela primeira vez que o aumento na motilidade, induzidos farmacologicamente resultam em divergências fenotípicas na proporção de segmentos anatômicos durante a ontogenia pré-natal, podendo alterar efetivamente a adaptação dos animais em ambientes específicos.

2.
Braz. j. biol ; 84: e252845, 2024. graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1355877

RESUMO

Abstract This study aimed to evaluate whether skeletal development of the Pantanal Caiman (Caiman yacare) is similarly influenced by temperature variation and controlled increases in embryo motility. All eggs were incubated at 90% humidity and 29 °C for the first 45 days. Thereafter, the incubation temperature was either maintained at 29 °C and embryos were treated with 4-aminopyridine (4-AP) on days 46, 47, 48, and 49 (Group I, 29 °C 4-AP, n = 15); maintained at 29 °C (n = 14; Group II); or at 33 °C (n = 14, Group III). Embryonic movement was measured using an Egg Buddy® digital monitor on days 30, 35, 42, 49, 56, and 60, at which point embryos were euthanized and samples were collected for analysis. No differences were observed between groups with varying incubation temperatures. In contrast, embryonic motility was greater in embryos treated with 4-AP (P < 0.001) on day 49, and this was associated with higher proportions of snout-vent and hand lengths. This study demonstrates for the first time that pharmacologically induced increases in embryo motility result in phenotypic changes to the proportion of elements during prenatal ontogeny, thereby effectively altering the adaptation of the species to specific environments.


Resumo Este estudo objetivou avaliar os efeitos da temperatura e motilidade embrionária sobre o desenvolvimento esquelético de jacaré-do-pantanal (Caiman yacare). Os ovos foram incubados com 90% de umidade e empregou-se a temperatura de 29°C por 45 dias. Após, para a incubação do Grupo I a temperatura continuou em 29°C, mas associou-se à injeção de 4-aminopiridina (29°C-4AP, n = 15) aplicada nos dias 46, 47, 48 e 49, do Grupo II permaneceu em 29°C (n = 14) e do Grupo III elevou-se para 33°C (n = 14). A movimentação foi mensurada através do monitor digital Egg Buddy® nos dias 30, 35, 42, 49, 56 e 60 dias. Aos 60 dias, os embriões foram eutanasiados e coletadas amostras embrionárias. Na análise estatística não foram observadas diferenças entre os grupos para o fator temperatura sobre a motilidade embrionária no desenvolvimento esquelético. Em contraste, a motilidade evidenciou diferença estatística no dia 49 para o Grupo I (P < 0,001) e apresentou maiores proporções de nariz e mão. Esses dados demonstraram pela primeira vez que o aumento na motilidade, induzidos farmacologicamente resultam em divergências fenotípicas na proporção de segmentos anatômicos durante a ontogenia pré-natal, podendo alterar efetivamente a adaptação dos animais em ambientes específicos.


Assuntos
Animais , Jacarés e Crocodilos , Temperatura
3.
Braz J Biol ; 84: e252845, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34932637

RESUMO

This study aimed to evaluate whether skeletal development of the Pantanal Caiman (Caiman yacare) is similarly influenced by temperature variation and controlled increases in embryo motility. All eggs were incubated at 90% humidity and 29 °C for the first 45 days. Thereafter, the incubation temperature was either maintained at 29 °C and embryos were treated with 4-aminopyridine (4-AP) on days 46, 47, 48, and 49 (Group I, 29 °C 4-AP, n = 15); maintained at 29 °C (n = 14; Group II); or at 33 °C (n = 14, Group III). Embryonic movement was measured using an Egg Buddy® digital monitor on days 30, 35, 42, 49, 56, and 60, at which point embryos were euthanized and samples were collected for analysis. No differences were observed between groups with varying incubation temperatures. In contrast, embryonic motility was greater in embryos treated with 4-AP (P < 0.001) on day 49, and this was associated with higher proportions of snout-vent and hand lengths. This study demonstrates for the first time that pharmacologically induced increases in embryo motility result in phenotypic changes to the proportion of elements during prenatal ontogeny, thereby effectively altering the adaptation of the species to specific environments.


Assuntos
Jacarés e Crocodilos , Animais , Temperatura
4.
Int J Pediatr Otorhinolaryngol ; 131: 109897, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31981915

RESUMO

Duplication of the pituitary gland (DPG) is a phenomenon with no clear syndromic association. This case adds to the literature as a DPG-plus syndrome patient with multiple fusion defects of unknown etiology, fetal risk factors of first trimester tobacco usage and intrauterine drug exposure. An 8-month old female presented with noisy breathing, poor feeding, cleft palate, seizures and failure to thrive. MRI scan revealed duplicate pituitary gland, tubomammillary fusion, absent cleavage of brainstem and superior cerebellar peduncles, and cervical spinal malformations. We performed an airway evaluation, with a glossomandibulopexy for glossoptosis, and a primary palate repair.


Assuntos
Artéria Basilar/anormalidades , Fissura Palatina/complicações , Anormalidades Craniofaciais/complicações , Hipófise/anormalidades , Fissura Palatina/diagnóstico , Anormalidades Craniofaciais/diagnóstico , Feminino , Humanos , Lactente , Imageamento por Ressonância Magnética , Síndrome
5.
Arq. bras. med. vet. zootec. (Online) ; 71(6): 1829-1834, Nov.-Dec. 2019. tab, graf
Artigo em Português | LILACS, VETINDEX | ID: biblio-1055116

RESUMO

Avaliou-se a recuperação anestésica e a analgesia residual da infusão contínua (IC) de fentanil (F), lidocaína (L), cetamina (K) e fentanil-lidocaína-cetamina (FLK), associados à anestesia total intravenosa com o propofol, em cadelas submetidas à ovariossalpingo-histerectomia. Foram utilizados 32 animais pré-medicados com acepromazina, distribuídos em quatro grupos de acordo com o tratamento analgésico: F: bolus de 0,0036mg/kg de fentanil e IC de 0,0036mg mg/kg/h; L: bolus de 3mg/kg de lidocaína e IC de 3mg/kg/h; K: bolus de 0,6mg/kg de cetamina e IC de 0,6mg/kg/h; e FLK: bolus e IC dos três fármacos nas doses supracitadas. Após o bolus do tratamento analgésico, foi realizada a indução e o início da IC do tratamento analgésico e do propofol. Para avaliação da recuperação anestésica, foram considerados os tempos de extubação, decúbito esternal, posição quadrupedal e os efeitos adversos. A avaliação da analgesia foi realizada por meio da escala visual analógica e modificada de Glasgow, durante seis horas. Os efeitos adversos observados foram vômito, sialorreia e tremor muscular. Receberam analgesia de resgate 100% dos animais do grupo F, 87,5% do K, 50% do L e 12,5% do FLK. O FLK demonstrou maior analgesia, e a recuperação anestésica foi semelhante em todos os grupos.(AU)


The anesthetic recovery and residual analgesia of continuous rate infusion (CRI) of fentanyl (F), lidocaine (L), ketamine (K) and fentanyl-lidocaine-ketamine (FLK) associated with total intravenous anesthesia with propofol in bitches submitted to ovariohysterectomy were evaluated. 32 animals were used, pre-medicated with acepromazine and distributed into four groups according to analgesic treatment: F loading dose (LD) of 0.0036mg/kg fentanyl, and CRI of 0.0036mg/kg/h, L: LD of 3mg/kg lidocaine, and CRI of 3mg/kg/h; K: LD of 0.6mg/kg ketamine, and CRI of 0.6mg/kg/h and FLK: LD and CRI of the three drugs in the above mentioned doses. After the LD of analgesic treatment, the induction was performed and the CRI of the analgesic treatment and propofol started. To evaluate the anesthetic recovery, the time of extubation, sternal decubitus, quadrupedal position and adverse effects were considered. The analgesia evaluation was performed using the visual scale and modified Glasgow for six hours. The adverse effects observed were vomiting, sialorrhea and muscle tremor. 100% of the animals in group F, 87.5% of K, 50% of L and 12.5% of FLK received rescue analgesia. FLK demonstrated greater analgesia, and anesthesia recovery was similar in all groups.(AU)


Assuntos
Animais , Feminino , Cães , Período de Recuperação da Anestesia , Propofol/administração & dosagem , Fentanila/administração & dosagem , Anestésicos Combinados/administração & dosagem , Ketamina/administração & dosagem , Lidocaína/administração & dosagem , Salpingostomia/veterinária , Ovariectomia/veterinária , Histerectomia/veterinária
6.
Arq. bras. med. vet. zootec ; 68(2): 307-312, mar.-abr. 2016. graf
Artigo em Português | LILACS | ID: lil-779780

RESUMO

O presente trabalho reporta as características clínicas e cirúrgicas de oito casos de cadelas portadoras de leiomioma vaginal, com histórico de aumento de volume na região perineal, aparecimento de massa pela vulva, disquezia, tenesmo e disúria. As pacientes foram submetidas à cirurgia de episiotomia para ressecção da massa neoplásica, e em quatro casos foi necessária a ovariossalpingo-histerectomia. Porém, uma delas apresentou recidiva, e, no segundo procedimento cirúrgico de exérese de neoformação, o histopatológico diagnosticou leiomiossarcoma. A paciente ainda apresentou mais duas recidivas, até o proprietário optar pela eutanásia. Decorridos quatro meses, as sete cadelas diagnosticadas com leiomioma não apresentaram recidiva, e os proprietários relataram ausência de sinais relacionados com a doença descrita. Conclui-se que a episiotomia para ressecção da massa vaginal e a ovariossalpingo-histerectomia nas cadelas inteiras nos casos de tumores vaginais benignos são tratamentos satisfatórios, com bom prognóstico, ao contrário do leiomiossarcoma.


This study reports the clinical and surgical procedures of eight cases of bitches with vaginal leiomyoma. All animals presented increased volume in the perineal region, and exteriorization of the vulva, dyschezia, tenesmus and dysuria. The patients underwent episiotomy surgery for resection of the neoplastic mass, and ovariosalpingohisterectomy in four cases. However, one had recurrence on the second surgical procedure for removal of neoformation, histopathological diagnosed leiomyosarcoma, the patient also had two more relapses, until the owner chose euthanasia. After four months, the seven dogs diagnosed with leiomyoma showed no recurrence and the owners reported no signs of the disease described. We concluded that episiotomy for vaginal mass resection combined with ovariohysterectomy in cases of benign vaginal tumors have shown satisfactory treatment with good prognostic.


Assuntos
Animais , Feminino , Cães , Episiotomia/veterinária , Leiomioma/cirurgia , Leiomioma/diagnóstico , Leiomioma/reabilitação , Leiomioma/veterinária , Neoplasias Vaginais/veterinária , Eutanásia Animal , Leiomiossarcoma/veterinária , Períneo/anormalidades
7.
Phys Rev Lett ; 95(3): 035001, 2005 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-16090748

RESUMO

The subject of high-energy-density (HED) states in matter is of considerable importance to numerous branches of basic as well as applied physics. Intense heavy-ion beams are an excellent tool to create large samples of HED matter in the laboratory with fairly uniform physical conditions. Gesellschaft für Schwerionenforschung, Darmstadt, is a unique worldwide laboratory that has a heavy-ion synchrotron, SIS18, that delivers intense beams of energetic heavy ions. Construction of a much more powerful synchrotron, SIS100, at the future international facility for antiprotons and ion research (FAIR) at Darmstadt will lead to an increase in beam intensity by 3 orders of magnitude compared to what is currently available. The purpose of this Letter is to investigate with the help of two-dimensional numerical simulations, the potential of the FAIR to carry out research in the field of HED states in matter.

8.
Z Kardiol ; 91(9): 715-8, 2002 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-12448071

RESUMO

We report on a 53-year-old patient in whom the aortic and mitral valves had been replaced. This patient developed Candida albicans sepsis with mycotic aneurysms of the tibial arteries as well as cerebral emboli under immunosuppression. Dispensing with a valve replacement operation, a sustained freedom from recurrence (period of observation currently 24 months) could be attained with antimycotic therapy with amphotericin B and flucytosine i.v. and subsequent long-term therapy with fluconazole p.o. as well as surgical and interventional clearance of the mycotic aneurysms.


Assuntos
Aneurisma Infectado/etiologia , Insuficiência da Valva Aórtica/cirurgia , Candidíase/etiologia , Endocardite/etiologia , Implante de Prótese de Valva Cardíaca , Insuficiência da Valva Mitral/cirurgia , Complicações Pós-Operatórias/etiologia , Artérias da Tíbia , Adulto , Aneurisma Infectado/diagnóstico , Aneurisma Infectado/tratamento farmacológico , Angiografia , Antifúngicos/administração & dosagem , Candidíase/diagnóstico , Candidíase/tratamento farmacológico , Endocardite/diagnóstico , Endocardite/tratamento farmacológico , Humanos , Embolia Intracraniana/diagnóstico , Embolia Intracraniana/tratamento farmacológico , Embolia Intracraniana/etiologia , Assistência de Longa Duração , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/tratamento farmacológico
9.
Phys Rev E Stat Nonlin Soft Matter Phys ; 63(3 Pt 2): 036407, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11308775

RESUMO

This paper presents two-dimensional numerical simulations of hydrodynamic response of a solid lead cylindrical target that is irradiated by an intense uranium beam having a particle energy of 1 GeV/u and that consists of 10(12) particles. Different time profiles have been considered for the beam power that include a case where the beam consists of five identical parabolic bunches with equal separation between neighboring bunches as well as a beam that consists of a single bunch. For the single bunch case we consider two different values for pulse length, namely, 1000 and 50 ns, respectively. Moreover we allow for two different values for the beam radius that is 0.5 and 1.0 mm, respectively. These calculations show that in order to achieve a high degree of beam-target coupling, it is absolutely essential to use a single bunched beam that has a reasonably short pulse length, which is 50 ns in this case. Such a large beam-target coupling efficiency is highly desirable for creating high-density strongly coupled plasmas as well as for studies that involve fragmentation of the projectile ions as the beam passes through solid matter. If the pulse length is assumed to be too long, substantial hydrodynamic expansion of the target material occurs during the early stages of irradiation that leads to significant reduction in the energy deposition by the ions that are delivered in the later part of the pulse. In case of the five-bunch configuration, heating caused by the first bunch is so strong that the target is completely distorted. As a result, the ions that are delivered in the later four bunches pass through the target without any interaction.

10.
Phys Rev E Stat Nonlin Soft Matter Phys ; 63(1 Pt 2): 016402, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11304360

RESUMO

Employing a two-dimensional simulation model, this paper presents a suitable design for an experiment to study metallization of hydrogen in a heavy-ion beam imploded multilayered cylindrical target that contains a layer of frozen hydrogen. Such an experiment will be carried out at the upgraded heavy-ion synchrotron facility (SIS-18) at the Gesellschaft für Schwerionenforschung, Darmstadt by the end of the year 2001. In these calculations we consider a uranium beam that will be available at the upgraded SIS-18. Our calculations show that it may be possible to achieve theoretically predicted physical conditions necessary to create metallic hydrogen in such experiments. These include a density of about 1 g/cm(3), a pressure of 3-5 Mbar, and a temperature of a few 0.1 eV.

11.
Artigo em Inglês | MEDLINE | ID: mdl-11088581

RESUMO

This paper presents two-dimensional numerical simulations of the hydrodynamic response of solid as well as hollow cylindrical targets made of lead that are irradiated by an intense beam of uranium ions which has an annular focal spot. Using a particle tracking computer code, it has been shown that a plasma lens can generate such a beam with parameters used in the calculations presented in this paper. The total number of particles in the beam is 2x10(11) and the particle energy is about 200 MeV/u that means a total energy of approximately 1.5 kJ. This energy is delivered in a pulse that is 50 ns long. These beam parameters lead to a specific energy deposition of 50-100 kJ/g and a specific power deposition of 1-2 TW/g in solid matter. These calculations show that in case of the solid lead cylinder, it may be possible to achieve more than 4 times solid lead density along the cylinder axis at the time of maximum compression. The pressure in the compressed region is about 20 Mbar and the temperature is a few eV. In the case of a hollow cylinder, one also achieves the same degree of compression but now the temperature in the compressed region is much higher (over 10 eV). Such samples of highly compressed matter can be used to study the equation-of-state properties of high-energy-density matter. It is expected that by the end of the year 2001, after completion of the upgrade of the existing facilities, the above beam parameters will be available at the Gesellschaft fur Schwerionenforschung (GSI), Darmstadt. This will open up the possibility to carry out very interesting experiments on a number of important problems including the investigation of the EOS of high-energy-density matter.

12.
Phys Rev Lett ; 85(21): 4518-21, 2000 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-11082585

RESUMO

A specifically tailored plasma lens could shape a high-energy, heavy-ion beam into the form of a hollow cylinder without loss of beam intensity. It has been experimentally confirmed that both a positive as well as a negative radial gradient of the current density in the active plasma lens can be the underlying principle. Calculations were performed that yield the ideal current density distribution for both cases. A numerical simulation of an experiment with an intense ion beam highlights that the shaping of the beam increases the achievable compression in a lead sample.

13.
Artigo em Inglês | MEDLINE | ID: mdl-11046484

RESUMO

In this paper is presented, with the help of sophisticated two-dimensional hydrodynamic simulations, a suitable design with optimized parameters for a heavy-ion beam-matter interaction experiment that will be carried out at the Gesellschaft fur Schwerionenforschung (GSI) Darmstadt by the end of the year 2001 when the upgrade of the existing accelerator facility will be completed. Our simulations show that this upgraded heavy-ion beam is capable of generating strong shocks in solid targets that compress the target material to supersolid densities and generate multi-mbar pressures. This will open up, at the GSI, the possibility of investigation of the equation-of-state properties of matter under such extreme conditions. Numerical simulations can predict the experimental results with reasonable accuracy, which is helpful in designing the diagnostic tools for the experiment.

14.
Basic Res Cardiol ; 95(3): 261-70, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10879628

RESUMO

The evaluation of regional myocardial blood flow (RMBF) during cardiac catheterization is of particular diagnostic interest. The purpose of this investigation was to validate x-ray densitometric parameters for the evaluation of RMBF. In five anesthetized dogs, arterial flow in the circumflex coronary artery was measured continuously with an electromagnetic flowmeter, and RMBF was determined by colored microspheres. Five different perfusion levels were created by mechanical obstruction of the coronary artery or by intravenous infusion of adenosine. At each steady-state perfusion level, digital subtraction coronary angiograms were obtained for densitometric analysis. Results documented a close correlation between the related time parameters 1/Mean Transit Time (1/MTT, r2 = 0.969), and 1/Rise Time (1/RT, r2 = 0.965) and RMBF over a wide range between 0.36 ml/(min x g) and 11.16 ml/(min x g). Maximum myocardial contrast density (Imax) also showed a good, but inverse correlation (r2 = 0.889) with RMBF and, therefore, did not reflect vascular volume. Contrast medium Appearance Time (AT) showed no correlation to RMBF (r2 = 0.017). Repeat densitometric measurements for different perfusion levels revealed a good reproducibility for MTT (accuracy: 0.001 s; precision: 0.447 s or 6.7 %) and RT (accuracy: 0.014 s; precision: 0.202 s or 10.4 %), while AT (accuracy: 0.072 s; precision: 0.420 s or 68.5%) and Imax (accuracy: 0.022 GL; precision: 1.197 GL or 44.5%) showed substantial variation. Myocardial perfusion reserve (MPR) calculated from RT (r2 = 0.90) or MTT (r2 = 0.94) showed better correlations to RMBF reserve than MPR calculated from AT (r2 = 0.04). In conclusion, only 1/MTT and 1/RT showed a good reproducibility and a close correlation to RMBF. Therefore, only these parameters can be recommended for calculations of RMBF and its reserve under clinical conditions.


Assuntos
Absorciometria de Fóton , Circulação Coronária , Animais , Velocidade do Fluxo Sanguíneo , Cães , Microesferas , Reprodutibilidade dos Testes
15.
Artigo em Inglês | MEDLINE | ID: mdl-11970337

RESUMO

It is expected that after the completion of a new high current injector, the heavy-ion synchrotron (SIS) at the Gesellschaft für Schwerionforschung (GSI) Darmstadt will accelerate U(+28) ions to energies of the order of 200 MeV/u. The use of a powerful rf buncher will reduce the pulse length to about 50 ns, and employment of a multiturn injection scheme will provide 2 x 10(11) particles in the beam that correspond to a total energy of the order of 1 kJ. This upgrade of the SIS, hopefully, will be completed by the end of the year 2001. These beam parameters lead to a specific power deposition of the order of 1-2 TW/g in solid matter that will provide temperatures of about 10 eV. Such low specific power deposition will induce hydrodynamic effects in solid materials, and one may design appropriate beam-target interaction experiments that could be used to investigate the equation of state of matter under extreme conditions. The purpose of this paper is to propose suitable target designs with optimized parameters for the future GSI experiments with the help of one and two-dimensional hydrodynamic simulations. Cylindrical geometry is the natural geometry for highly focused ion beams, and therefore cylindrical targets are the most appropriate for this type of interaction experiments. The numerical simulations presented in this paper show that one can experimentally measure the characteristic sound speed in beam heated targets which is an important physical parameter. Moreover, one can study the propagation of ion-beam-induced shock waves in the solid materials. Different values for the specific power deposition, namely, 10, 25, 50, and 100 kJ/g, have been used. In some cases the pulse length is assumed to be 40 ns while in others it is considered to be 50 ns. Various materials including lead, aluminum, and solid neon have been used.

16.
Herz ; 22(2): 72-86, 1997 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-9206707

RESUMO

X-ray densitometric evaluation of digital subtraction coronary arteriograms allows a qualitative and quantitative detection of contrast medium propagation through the epicardial coronary arteries, the capillary system and the coronary venous system. So-called "time-density-curves" (TDCs) can be generated following Lambert-Beer's law similar to indicator dilution curves by using contrast medium as the indicator. Several time and density parameters can be derived from these TDCs, which are related to local myocardial perfusion. Different animal validation studies have shown the applicability of this concept for in-vivo evaluation of coronary blood flow and myocardial perfusion. Nevertheless, absolute measurement of volumetric coronary blood flow or myocardial perfusion failed. Therefore, relative changes in coronary blood flow or myocardial perfusion in response to pharmacologically induced maximum hyperemia were measured and coronary or myocardial perfusion reserve was calculated as the ratio of hyperemic flow or perfusion divided by baseline values. Despite theoretical attractions for an application during routine cardiac catheterization, this densitometric approach did not get a wide acceptance. Primary reason for this limited use in specialized centers was the time consuming process of densitometric evaluation of the subtraction coronary arteriograms, which require digital cine angiography and necessitates enormous computer hard ware. This main limitation has been overcome since more powerful computer hard ware (processor speed, hard disk space, digitization boards) has become rapidly available during the last years at more moderate pricing and digital techniques today are state of the art in cardiac catheterization laboratories. In addition, soft ware program packages allowed an automatization of the digitization and densitometric evaluation process. These programs include ECG triggered cine image digitization with improved temporal resolution, semiautomatic definition of regions-of-interest including definition of reference regions-of-interest for the detection of background density changes and quality-controlled densitometric parameter analysis. This progress made an application during routine cardiac catheterization feasible. In animal validation studies this improved X-ray densitometric approach for evaluation of local myocardial perfusion was validated versus colour-coded microsphere techniques. The time parameter "rise time", defined as the time from the start of local contrast medium induced density change to its maximum revealed a close correlation (r2 = 0.965) to the results of the microsphere technique over a wide range of perfusion. We have applied this technique before and after coronary interventions such as balloon angioplasty and stenting. Results documented an improvement of poststenotic myocardial perfusion reserve immediately after coronary balloon angioplasty and an additional improvement after adjunct coronary stenting. Only after stenting but usually not after coronary balloon angioplasty alone poststenotic myocardial perfusion reserve gained the intraindividual reference level, measured in a perfusion bed supplied by an epicardial coronary artery without stenoses. These results documented the functional benefit of coronary stenting on poststenotic myocardial perfusion in addition to the well known morphologic benefit with the creation of a larger and more circular conduit.


Assuntos
Absorciometria de Fóton/instrumentação , Angiografia Digital/instrumentação , Cateterismo Cardíaco/instrumentação , Angiografia Coronária/instrumentação , Circulação Coronária/fisiologia , Doença das Coronárias/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/instrumentação , Angioplastia Coronária com Balão/instrumentação , Animais , Sistemas Computacionais , Doença das Coronárias/fisiopatologia , Doença das Coronárias/terapia , Eletrocardiografia/instrumentação , Humanos , Software , Stents , Resultado do Tratamento
17.
Thorax ; 52(3): 298-9, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9093354

RESUMO

Pain in hypertrophic pulmonary osteoarthropathy (HPOA) due to periostitis and arthropathy can be a particularly disabling symptom, and resistant to a wide variety of treatments. The effectiveness of subcutaneous octreotide in relieving this pain in a patient with HPOA is reported.


Assuntos
Hormônios/uso terapêutico , Octreotida/administração & dosagem , Osteoartropatia Hipertrófica Secundária/tratamento farmacológico , Neoplasias Brônquicas/complicações , Carcinoma de Células Escamosas/complicações , Humanos , Injeções Subcutâneas , Masculino , Pessoa de Meia-Idade , Octreotida/uso terapêutico , Osteoartropatia Hipertrófica Secundária/etiologia , Dor/tratamento farmacológico , Dor/etiologia
20.
Rofo ; 153(3): 252-9, 1990 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-2171056

RESUMO

Digital subtraction angiography allows to record the passage of contrast material through the myocardium as a time-intensity curve, the so-called densogram. Temporal changes of contrast material in a region of interest are described by a differential equation. The free parameters of this model equation are determined by a curve-fitting procedure. Four parameters of the model equation are expected to be connected with myocardial perfusion. We intended to verify this assumption by comparing changes in coronary blood flow (CBF) with changes of the different parameters. The angiograms of 9 patients without coronary artery disease were studied before and after intravenous application of dipyridamole. Changes in CBF were assessed by a videodensitometric method. Linear regressions between changes of CBF and the parameters of the differential equation show the following results: one parameter of the model equation--the ratio of regional blood flow and regional volume--remarkably underestimated CBF changes. This can be explained by an increase of regional blood volume after increased CBF due to dipyridamole. However, a close correlation was found between CBF changes and the remaining parameters. This study suggests that digital measurements from coronary angiograms using the presented model equation provide a means of assessing myocardial perfusion.


Assuntos
Meios de Contraste/farmacocinética , Angiografia Coronária , Circulação Coronária , Miocárdio/metabolismo , Adulto , Idoso , Angiografia Digital , Diatrizoato de Meglumina , Dipiridamol , Humanos , Pessoa de Meia-Idade
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