Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 16 de 16
Filter
Add more filters










Publication year range
1.
PLoS One ; 15(8): e0237616, 2020.
Article in English | MEDLINE | ID: mdl-32790803

ABSTRACT

Patients with large iris defects not only suffer from functional disadvantages but also from aesthetic limitations. The aim of this study was to evaluate the aesthetic outcome of iris reconstruction using an artificial iris (AI). In this study, 82 eyes of 79 consecutive patients with mostly traumatic partial or total aniridia that underwent iris reconstruction surgery using a custom-made silicone AI (HumanOptics, Erlangen, Germany). Pre- and postoperative photographs of 66 patients were analysed subjectively and objectively. Subjective evaluation was based questionnaires. Objective evaluation included measurement of pupil centration and iris colour analysis. Averaged hues from iris areas were transferred to numerical values using the LAB-colour-system. Single parameters and overall difference value (ΔE) were compared between AI and remaining iris (RI), as well as AI and fellow eye iris (FI). Patients, eye doctors and laymen rated the overall aesthetic outcome with 8.9 ±1.4, 7.7 ±1.1 and 7.3 ±1.1 out of 10 points, respectively. Mean AI decentration was 0.35 ±0.24 mm. Better pupil centration correlated with a higher overall score for aesthetic outcome (p<0.05). The AI was on average 4.65 ±10 points brighter than RI and FI. Aniridia treatment using a custom-made artificial iris prosthesis offers a good aesthetic outcome. Pupil centration was a key factor that correlated with the amount of aesthetic satisfaction. The AI was on average slightly brighter than the RI and FI.


Subject(s)
Aniridia/therapy , Artificial Organs/statistics & numerical data , Iris/surgery , Plastic Surgery Procedures/methods , Prosthesis Implantation , Adolescent , Adult , Aged , Aged, 80 and over , Esthetics , Female , Humans , Male , Middle Aged , Young Adult
2.
J Feline Med Surg ; 22(12): 1155-1159, 2020 12.
Article in English | MEDLINE | ID: mdl-32228276

ABSTRACT

OBJECTIVES: Owing to the lack of literature on training cats to use an artificial vagina (AV), we performed a retrospective study on the success of training tom cats for semen collection using an AV. METHODS: Records from training 20 cats (2009 until 2019) for semen collection using AVs were analyzed. Sexual preferences, behavior towards humans, queens and other tom cats, as well as libido, number of training sessions and rate of success were observed. Data are presented as percentages and the results are described subjectively. RESULTS: In 85% of tom cats, collection using an AV was performed successfully. Training was unsuccessful when libido was low or absent. Behavior towards humans did not interfere with the success rate, while libido did. CONCLUSIONS AND RELEVANCE: Most tom cats can be successfully trained to have semen collected using an AV; the number of training sessions required depends on the male's libido and the technician's experience.


Subject(s)
Artificial Organs/veterinary , Semen , Specimen Handling/veterinary , Vagina , Animals , Artificial Organs/statistics & numerical data , Cats , Female , Male , Retrospective Studies
3.
Pesqui. vet. bras ; 36(10): 986-992, out. 2016. ilus
Article in English | LILACS, VETINDEX | ID: biblio-841990

ABSTRACT

In order to test the performance of bacterial cellulose/polycaprolactone composite (BC/PCL) and pure bacterial cellulose (BC) as tissue substitutes in rabbits' cornea, a superficial ulcer containing 5mm in diameter and 0.2mm deep was made in the right cornea of 36 rabbits, then a interlayer pocket was created from the basis of this ulcer. Twelve rabbits received BC/PCL membrane and 12 were treated with BC membranes, both membranes with 8mm in diameter. The remaining rabbits received no membrane constituting the control group. The animals were clinically followed up for 45 days. Three animals of each group were euthanized at three, seven, 21, and 45 days after implantation for histological examination of the cornea along with the implant. Clinical observation revealed signs of moderate inflammatory process, decreasing from day 20th in the implanted groups. Histology showed absence of epithelium on the membranes, fibroplasia close to the implants, lymph inflammatory infiltrate with giant cells, collagen disorganization, with a predominance of immature collagen fibers in both groups with implants. Although inflammatory response is acceptable, the membranes used does not satisfactorily played the role of tissue substitute for the cornea during the study period.(AU)


Com objetivo de testar o desempenho do compósito celulose bacteriana/policaprolactona (CB/PCL) e da celulose bacteriana pura (CB) como substitutos teciduais em córnea de coelhos, foi realizada uma úlcera superficial de 5 mm de diâmetro e 0,2 mm de profundidade na córnea direita de 36 coelhos, criando-se um bolso interlamelar a partir da base dessa úlcera. Doze animais receberam a membrana do compósito CB/PCL e 12 foram tratados com membranas de CB, ambas com 8 mm de diâmetro, os coelhos restantes não receberam nenhuma membrana, constituindo o grupo controle. Os animais foram acompanhados clinicamente até 45 dias. Três animais de cada grupo sofreram eutanásia aos três, sete, 21 e 45 dias após o implante das membranas para análise histológica da córnea juntamente com o implante. À observação clínica, houve sinais de processo inflamatório moderado, diminuindo a partir do 20º dia nos grupos implantados. A histologia demonstrou ausência de epitélio sobre as membranas, fibroplasia próxima aos implantes, infiltrado inflamatório linfo-histiocitário com células gigantes, desorganização do colágeno, com predominância de fibras imaturas de colágeno em ambos os grupos com implantes. Embora a resposta inflamatória seja aceitável, as membranas utilizadas não desempenharam satisfatoriamente o papel de substituto tecidual para a córnea, no período estudado.(AU)


Subject(s)
Animals , Rabbits , Artificial Organs/statistics & numerical data , Artificial Organs/veterinary , Biopolymers/analysis , Cellulose/analysis , Cornea/surgery , Gluconacetobacter xylinus , Allografts , Cell- and Tissue-Based Therapy/methods , Cell- and Tissue-Based Therapy/veterinary
4.
Comput Math Methods Med ; 2013: 570878, 2013.
Article in English | MEDLINE | ID: mdl-24319495

ABSTRACT

The construction of artificial muscles is one of the most challenging developments in today's biomedical science. The application of artificial muscles is focused both on the construction of orthotics and prosthetics for rehabilitation and prevention purposes and on building humanoid walking machines for robotics research. Research in biomechanics tries to explain the functioning and design of real biological muscles and therefore lays the fundament for the development of functional artificial muscles. Recently, the hyperbolic Hill-type force-velocity relation was derived from simple mechanical components. In this contribution, this theoretical yet biomechanical model is transferred to a numerical model and applied for presenting a proof-of-concept of a functional artificial muscle. Additionally, this validated theoretical model is used to determine force-velocity relations of different animal species that are based on the literature data from biological experiments. Moreover, it is shown that an antagonistic muscle actuator can help in stabilising a single inverted pendulum model in favour of a control approach using a linear torque generator.


Subject(s)
Models, Biological , Muscles/physiology , Animals , Artificial Organs/statistics & numerical data , Biomechanical Phenomena , Computer Simulation , Humans , Muscle Contraction/physiology
5.
Transplantation ; 90(6): 604-11, 2010 Sep 27.
Article in English | MEDLINE | ID: mdl-20048693

ABSTRACT

BACKGROUND: Fibrous tissue outgrowth and hypoxia are the major restrictions for the application of bioartificial pancreas (BAP). Accordingly, the intramedullary cavity is proposed as an implant site, and a BAP constructed of calcium phosphate cement chamber was implanted. METHODS: Mouse insulinoma cells were encapsulated in agarose gel and then enclosed in a calcium phosphate cement chamber to fabricate a BAP. BAPs were implanted in the femoral intramedullary cavity of diabetic dogs. Pre- and postprandial blood glucose levels were monitored perioperatively. Blood samples were collected for the analysis of C-peptide level, and physiological conditions were observed at predetermined intervals. BAPs were retrieved at 12 weeks postoperatively for histologic examination. RESULTS: Preprandial blood glucose level of diabetic dogs decreased from 420 ± 25 to 223 ± 47 mg/dL at 1 day postoperatively and was maintained in the range of 259 ± 36 mg/dL for 12 weeks. As serum C-peptide level increased from 5.3 ± 2.8 to 105.7 ± 19.4 pmol/L, the rate of decrease of postprandial blood glucose was accelerated. Histologic examination revealed that recipient bone tissues were binding to the surfaces of BAPs directly; there was no development of fibrous tissue. Immunohistochemical stain was positive for insulin in the enclosed insulinoma cells. CONCLUSIONS: This study demonstrated that BAPs implanted into the intramedullary cavity functioned well during the experimental period. Thus, the intramedullary cavity can serve as an implant site for BAPs.


Subject(s)
Artificial Organs/statistics & numerical data , Blood Glucose/metabolism , Diabetes Mellitus, Experimental/surgery , Pancreas Transplantation/methods , Animals , C-Peptide/metabolism , Diabetes Mellitus, Experimental/blood , Dogs , Female , Humans , Insulinoma , Islets of Langerhans/pathology , Male , Mice , Pancreas Transplantation/pathology , Tissue Donors/supply & distribution
6.
Invest Ophthalmol Vis Sci ; 49(9): 3887-94, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18515574

ABSTRACT

PURPOSE: To compare the efficacies of recombinant human collagens types I and III as corneal substitutes for implantation. METHODS: Recombinant human collagen (13.7%) type I or III was thoroughly mixed with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide. The final homogenous solution was either molded into sheets for in vitro studies or into implants with the appropriate corneal dimensions for transplantation into minipigs. Animals with implants were observed for up to 12 months after surgery. Clinical examinations of the cornea included detailed slit lamp biomicroscopy, in vivo confocal microscopy, and fundus examination. Histopathologic examinations were also performed on corneas harvested after 12 months. RESULTS: Both cross-linked recombinant collagens had refractive indices of 1.35, with optical clarity similar to that in human corneas. Their chemical and mechanical properties were similar, although RHC-III implants showed superior optical clarity. Implants into pig corneas over 12 months show comparably stable integration, with regeneration of corneal cells, tear film, and nerves. Optical clarity was also maintained in both implants, as evidenced by fundus examination. CONCLUSIONS: Both RHC-I and -III implants can be safely and stably integrated into host corneas. The simple cross-linking methodology and recombinant source of materials makes them potentially safe and effective future corneal matrix substitutes.


Subject(s)
Artificial Organs/statistics & numerical data , Biocompatible Materials/chemistry , Collagen Type III/genetics , Collagen Type I/genetics , Collagen/physiology , Cornea/physiology , Corneal Transplantation/methods , Biomechanical Phenomena , Humans , Recombinant Proteins , Refractometry , Tensile Strength , Tissue Engineering/methods
7.
Prenat Diagn ; 24(7): 570-2, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15300751
8.
J Pediatr Surg ; 38(6): 971-4, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12778405

ABSTRACT

BACKGROUND: The authors noticed a relatively large number of patients with congenital diaphragmatic hernia (CDH) repair after extracorporeal membrane oxygenation (ECMO) who had a chylothorax (CT). The data are reviewed. METHODS: The charts of patients from 1990 until 2000 with CDH, treated with or without ECMO, together with the charts of patients treated with ECMO for other reasons and patients with esophageal atresia (EA) repair were reviewed. The diagnosis of CT was made if aspirated fluid appeared chylous and contained more than 90% lymphocytes or if the triglyceride level was more than 1.50 mmol/L. RESULTS: Eighty-nine patients with CDH were analyzed. Postoperatively, 10% had a CT-21% in CDH patients with ECMO treatment and 6% in CDH patients without ECMO treatment. This difference appeared to be significant (P <.05). The presence of a patch as independent variable for the development of CT also showed significance (P <.05). CONCLUSIONS: Chylothorax presented in almost all cases as a left-sided fluid accumulation, and a patch was present in the majority of patients with CDH. Therefore, CT should be considered the result of the severity of the defect rather than the consequence of ECMO as a therapeutic modality.


Subject(s)
Chylothorax/epidemiology , Extracorporeal Membrane Oxygenation/adverse effects , Extracorporeal Membrane Oxygenation/methods , Hernia, Diaphragmatic/surgery , Hernias, Diaphragmatic, Congenital , Artificial Organs/adverse effects , Artificial Organs/statistics & numerical data , Birth Weight , Chylothorax/diagnosis , Esophageal Atresia/complications , Esophageal Atresia/surgery , Extracorporeal Membrane Oxygenation/statistics & numerical data , Female , Gestational Age , Humans , Infant, Newborn , Likelihood Functions , Male , Postoperative Complications/diagnosis , Postoperative Complications/etiology , Umbilical Arteries/metabolism , Umbilical Veins/metabolism
9.
Article in English | MEDLINE | ID: mdl-12751825

ABSTRACT

Nowadays artificial devices are not able to totally and undefinitely replace the loss of function of all vital organs and artificial organs can be used only to bridge the time to transplantation, which must be considered the first choice in the therapeutical approach for many chronic diseases. Since general population aging process is leading to an increase of organ demand, the gap between performed and requested transplantation is hard to fill. Xenotransplantation is nowadays only an experimental alternative solution and we have to do our best using available artificial organs to increase and improve the survival of patients waiting for transplantation. In this meeting we particularly dealt about organ function replacing therapy, especially regarding the kidney, heart, liver, pancreas and ear.


Subject(s)
Artificial Organs/statistics & numerical data , Organ Transplantation/statistics & numerical data , Animals , Artificial Organs/history , Artificial Organs/trends , History, 20th Century , History, 21st Century , Humans , Organ Transplantation/history , Organ Transplantation/trends , Transplantation, Heterologous , Transplantation, Homologous
10.
Tissue Eng ; 7(5): 485-93, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11694183

ABSTRACT

This report draws upon data from a variety of sources to estimate the size, scope, and growth rate of the contemporary tissue engineering enterprise. At the beginning of 2001, tissue engineering research and development was being pursued by 3,300 scientists and support staff in more than 70 startup companies or business units with a combined annual expenditure of over $600 million. Spending by tissue engineering firms has been growing at a compound annual rate of 16%, and the aggregate investment since 1990 now exceeds $3.5 billion. At the beginning of 2001, the net capital value of the 16 publicly traded tissue engineering startups had reached $2.6 billion. Firms focusing on structural applications (skin, cartilage, bone, cardiac prosthesis, and the like) comprise the fastest growing segment. In contrast, efforts in biohybrid organs and other metabolic applications have contracted over the past few years. The number of companies involved in stem cells and regenerative medicine is rapidly increasing, and this area represents the most likely nidus of future growth for tissue engineering. A notable recent trend has been the emergence of a strong commercial activity in tissue engineering outside the United States, with at least 16 European or Australian companies (22% of total) now active.


Subject(s)
Tissue Engineering/trends , Artificial Organs/economics , Artificial Organs/statistics & numerical data , Artificial Organs/trends , Australia , Cell Transplantation/economics , Cell Transplantation/statistics & numerical data , Europe , Industry/economics , Industry/statistics & numerical data , Industry/trends , Tissue Engineering/economics , Tissue Engineering/statistics & numerical data , Tissue Transplantation/economics , Tissue Transplantation/statistics & numerical data , Tissue Transplantation/trends , United States
11.
J Heart Lung Transplant ; 18(10): 1014-7, 1999 Oct.
Article in English | MEDLINE | ID: mdl-10561112

ABSTRACT

BACKGROUND: Our study evaluated the efficacy and feasibility of a pumpless respiratory assist device and determined its capacity for carbon dioxide removal. METHODS: In five adult pigs the left femoral vein and artery were cannulated with a 20F cannula and connected to a low-pressure hollow-fiber artificial lung. After we had obtained baseline values of mean arterial pressure, cardiac output, and blood flow across the artificial lung, the mean arterial pressure was reduced 20% and 40% relative to baseline; in a second phase, it was raised 20% and 40. Cardiac output and artificial lung flow were simultaneously recorded. We determined the carbon dioxide removal capacity of the artificial lung by gradually increasing the arterial partial carbon dioxide tension of the animal. RESULTS: An increase of 10 mm Hg in mean arterial pressure resulted in an increase of flow of 0.14 L/min. The mean pressure drop across the artificial lung was measured at 17 +/- 9 mm Hg. The shunt flow over the artificial lung varied between 14 and 25% of the cardiac output of the animal. Depending on inlet conditions, carbon dioxide removal by the artificial lung was between 62 +/- 22 mL/L/min and 104 +/- 25 mL/L/min. CONCLUSIONS: A pumpless respiratory assist device can remove a significant proportion of the metabolic carbon dioxide production. However, adequate mean arterial pressure is mandatory to maintain sufficient flow across the device. The technique seems attractive because of its simplicity and can be used in acute lung injury in conjunction of apneic oxygenation for prolonged respiratory support.


Subject(s)
Artificial Organs , Lung , Oxygenators , Respiration, Artificial/instrumentation , Airway Resistance , Animals , Artificial Organs/statistics & numerical data , Feasibility Studies , Female , Hemodynamics , Lung/physiology , Male , Oxygenators/statistics & numerical data , Respiration, Artificial/statistics & numerical data , Swine
12.
Intensive Care Med ; 25(9): 997-1002, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10501758

ABSTRACT

OBJECTIVE: Thus far only few data are available on airway humidification during high-frequency oscillatory ventilation (HFOV). Therefore, we studied the performance and efficiency of a heated humidifier (HH) and a heat and moisture exchanger (HME) in HFOV using an artificial lung model. METHODS: Experiments were performed with a pediatric high-frequency oscillatory ventilator. The artificial lung contained a sponge saturated with water to simulate evaporation and was placed in an incubator heated to 37 degrees C to prevent condensation. The airway humidity was measured using a capacitive humidity sensor. The water loss of the lung model was determined gravimetrically. RESULTS: The water loss of the lung model varied between 2.14 and 3.1 g/h during active humidification; it was 2.85 g/h with passive humidification and 7.56 g/h without humidification. The humidity at the tube connector varied between 34. 2 and 42.5 mg/l, depending on the temperature of the HH and the ventilator setting during active humidification, and between 37 and 39.9 mg/l with passive humidification. CONCLUSION: In general, HH and HME are suitable devices for airway humidification in HFOV. The performance of the ventilator was not significantly influenced by the mode of humidification. However, the adequacy of humidification and safety of the HME remains to be demonstrated in clinical practice.


Subject(s)
Artificial Organs , High-Frequency Ventilation/instrumentation , Lung , Artificial Organs/statistics & numerical data , Equipment Design/statistics & numerical data , High-Frequency Ventilation/methods , High-Frequency Ventilation/statistics & numerical data , Hot Temperature , Humans , Humidity , Infant, Newborn , Pressure , Temperature , Transducers, Pressure
14.
Med Eng Phys ; 20(7): 534-42, 1998 Oct.
Article in English | MEDLINE | ID: mdl-9832029

ABSTRACT

This study reports on a ventilator system that consists of several intelligent modules for controlling ventilator operation. These modules are software programs in two controllers. One controller is a personal computer used for diagnoses, determining settings and checking the effects of settings. The other controller is a single-chip microprocessor in a ventilator that controls the ventilator's settings in accordance with the computer settings. After setting up the system, an artificial lung model simulating a patient's lung is used to test the system. The result of test run indicated that it always responds to a patient's lung condition in a stable manner. Thus, the proposed system with its intelligent modules may assist clinicians in caring for patients and managing ventilator operation.


Subject(s)
Artificial Intelligence , Ventilators, Mechanical , Algorithms , Artificial Organs/statistics & numerical data , Compliance , Equipment Design/statistics & numerical data , Humans , Lung , Microcomputers , Ventilators, Mechanical/statistics & numerical data
SELECTION OF CITATIONS
SEARCH DETAIL
...