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1.
J Imaging Inform Med ; 37(2): 601-610, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38343226

ABSTRACT

Patella alta (PA) and patella baja (PB) affect 1-2% of the world population, but are often underreported, leading to potential complications like osteoarthritis. The Insall-Salvati ratio (ISR) is commonly used to diagnose patellar height abnormalities. Artificial intelligence (AI) keypoint models show promising accuracy in measuring and detecting these abnormalities.An AI keypoint model is developed and validated to study the Insall-Salvati ratio on a random population sample of lateral knee radiographs. A keypoint model was trained and internally validated with 689 lateral knee radiographs from five sites in a multi-hospital urban healthcare system after IRB approval. A total of 116 lateral knee radiographs from a sixth site were used for external validation. Distance error (mm), Pearson correlation, and Bland-Altman plots were used to evaluate model performance. On a random sample of 2647 different lateral knee radiographs, mean and standard deviation were used to calculate the normal distribution of ISR. A keypoint detection model had mean distance error of 2.57 ± 2.44 mm on internal validation data and 2.73 ± 2.86 mm on external validation data. Pearson correlation between labeled and predicted Insall-Salvati ratios was 0.82 [95% CI 0.76-0.86] on internal validation and 0.75 [0.66-0.82] on external validation. For the population sample of 2647 patients, there was mean ISR of 1.11 ± 0.21. Patellar height abnormalities were underreported in radiology reports from the population sample. AI keypoint models consistently measure ISR on knee radiographs. Future models can enable radiologists to study musculoskeletal measurements on larger population samples and enhance our understanding of normal and abnormal ranges.

2.
Vet J ; 249: 24-32, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31239161

ABSTRACT

This meta-analysis evaluated the use of potential dietary feed additives (pDFA) with antibacterial effects and their impact on the perfomance of weaned piglets. Twenty-three peer-reviewed in vivo studies, comprising 50 trials, were identified between January 2010 and January 2017. The pDFA in these studies could be grouped in 5 classes: antimicrobial peptides, chitosan, lysozyme, medium chain fatty acids/ triglycerides and plant extracts. Mixed-effect meta-analyses with type of pDFA as fixed effect were performed for the growth parameters 'average daily gain' (ADG) and 'feed conversion ratio' (FCR), which are the two most important and used economic performance parameters for farmers. For each class of pDFA, results of the meta-analysis showed significantly higher average daily gain in the group with pDFA compared to the negative control group, while no significant difference with the positive control group was observed. Furthermore, a positive effect on FCR was found, i.e. significantly less feed was needed to gain 1 kg of body weight in the group with pDFA compared to the negative control group. No significant differences with positive control groups were observed for each class of pDFA, except for plant extracts, where the FCR was also significantly reduced in the treatment group. These results suggest that pDFA could reduce the use of antimicrobials without significant negative effects on performance indicators.


Subject(s)
Animal Feed , Anti-Bacterial Agents/pharmacology , Food Additives/pharmacology , Swine/growth & development , Animals , Anti-Bacterial Agents/administration & dosage , Weaning , Weight Gain
3.
Animal ; 13(10): 2125-2132, 2019 Oct.
Article in English | MEDLINE | ID: mdl-30846009

ABSTRACT

Genetic evaluation of Piétrain sires in Flanders occurs under standardized conditions, on test stations with fixed dam breeds, standardized diets and uniform management practices. As environmental conditions vary on commercial farms and differ from the test stations, this study aimed at understanding to what extent the sire, the dam breed and the interaction between both affects the translation of breeding values to practice. Dams of two commercial breeds were inseminated with semen from one of five different sires selected for contrasting breeding values (daily gain, feed conversion ratio and carcass quality). For each sire by dam breed combination, six pen replicates (with three gilts and three barrows per pen) were evaluated for growth performance from 9 weeks of age (20 kg) to slaughter (110 kg), and for carcass and meat quality. In our experimental setup, both sire and dam breed affected growth, carcass and meat quality traits. No significant sire×dam breed interactions on performance could be detected. Though a tendency for interaction on average daily feed intake between 20 and 110 kg (P=0.087), and on pork colour (lightness) (P=0.093) was present. In general, offspring of all tested sires behaved similarly in both dam breeds, indicating that estimated breeding values for Piétrain sires determined in one dam breed are representative in other dam breeds as well.


Subject(s)
Red Meat/standards , Swine/physiology , Animals , Breeding , Diet/veterinary , Female , Male , Phenotype , Swine/genetics , Swine/growth & development
4.
Animal ; 13(1): 64-73, 2019 Jan.
Article in English | MEDLINE | ID: mdl-29745350

ABSTRACT

Dietary resistant starch (RS) may have prebiotic properties but its effects on fermentation and the microbial population are inconsistent. This meta-analysis aimed to quantify the relationship between RS type 2 (RS2) and intestinal short-chain fatty acids (SCFA) and pH as well as certain key bacterial taxa for intestinal health in pigs. From the 24 included articles with sufficient information about the animal, and dietary and physiological measurements published between 2000 and 2017, individual sub-data sets for fermentation metabolites, pH, bacterial abundances and apparent total tract digestibility were built and used to parameterize prediction models on the effect of RS2, accounting for inter- and intra-study variability. In addition, the effect of pig's BW at the start of the experiment and duration of the experimental period on response variables were also evaluated using backward elimination analysis. Dietary RS levels ranged from 0% to 78.0% RS, with median and mean RS levels of 28.8% and 23.0%, respectively. Negative relationships could be established between dietary RS and pH in the large intestine (P<0.05), with a stronger effect in the mid and distal colon, and feces (R 2=0.64 to 0.81; P<0.001). A dietary level of 15% RS would lower the pH in the proximal, mid-, distal colon and feces by 0.2, 0.6, 0.4 and 0.6 units, respectively. Increasing RS levels, however, did not affect SCFA concentrations in the hindgut, but enhanced the molar proportion of propionate in mid-colon and reduced those of acetate in mid-colon and of butyrate in mid- and distal colon (R 2=0.46 to 0.52; P<0.05). Backward elimination indicated an age-related decrease in mid-colonic propionate proportion and increase in mid- and distal colonic butyrate proportion (P<0.05), thereby modulating RS2 effects. In feces, increasing RS levels promoted fecal lactobacilli (R 2=0.46; P<0.01) and bifidobacteria (R 2=0.57; P<0.01), whereby the slope showed the need for a minimal RS level of 10% for a 0.5 log unit-increase in their abundance. Best-fit equations further supported that a longer experimental period increased fecal lactobacilli but decreased fecal bifidobacteria (P<0.05). In conclusion, dietary RS2 seems to effectively decrease digesta pH throughout the large intestine and increase lactic acid-producing bacteria in feces of pigs which may limit the growth of opportunistic pathogens in the hindgut. To achieve these physiologically relevant changes, dietary RS should surpass 10% to 15%.


Subject(s)
Bifidobacterium/physiology , Lactobacillus/physiology , Starch/chemistry , Starch/metabolism , Swine/physiology , Animal Feed/analysis , Animal Nutritional Physiological Phenomena , Animals , Bacteria/metabolism , Butyrates/metabolism , Colon/microbiology , Diet/veterinary , Dietary Carbohydrates/metabolism , Fatty Acids, Volatile/metabolism , Feces/chemistry , Feces/microbiology , Female , Fermentation , Intestine, Large , Male , Prebiotics , Propionates/metabolism
5.
Science ; 355(6332): 1416-1420, 2017 03 31.
Article in English | MEDLINE | ID: mdl-28360328

ABSTRACT

The parasitic protists of the Trypanosoma genus infect humans and domestic mammals, causing severe mortality and huge economic losses. The most threatening trypanosomiasis is Chagas disease, affecting up to 12 million people in the Americas. We report a way to selectively kill Trypanosoma by blocking glycosomal/peroxisomal import that depends on the PEX14-PEX5 protein-protein interaction. We developed small molecules that efficiently disrupt the PEX14-PEX5 interaction. This results in mislocalization of glycosomal enzymes, causing metabolic catastrophe, and it kills the parasite. High-resolution x-ray structures and nuclear magnetic resonance data enabled the efficient design of inhibitors with trypanocidal activities comparable to approved medications. These results identify PEX14 as an "Achilles' heel" of the Trypanosoma suitable for the development of new therapies against trypanosomiases and provide the structural basis for their development.


Subject(s)
Membrane Proteins/antagonists & inhibitors , Protozoan Proteins/antagonists & inhibitors , Small Molecule Libraries/pharmacology , Trypanocidal Agents/pharmacology , Trypanosoma brucei brucei/drug effects , Animals , Chagas Disease/drug therapy , Drug Design , Humans , Membrane Proteins/chemistry , Microbodies/drug effects , Microbodies/metabolism , Nuclear Magnetic Resonance, Biomolecular , Peroxisome-Targeting Signal 1 Receptor , Peroxisomes/drug effects , Peroxisomes/metabolism , Protein Domains , Protein Transport/drug effects , Protozoan Proteins/chemistry , Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors , Receptors, Cytoplasmic and Nuclear/chemistry , Receptors, Cytoplasmic and Nuclear/metabolism , Small Molecule Libraries/chemistry , Small Molecule Libraries/therapeutic use , Trypanocidal Agents/chemistry , Trypanocidal Agents/therapeutic use , Trypanosomiasis, African/drug therapy
6.
J Anim Physiol Anim Nutr (Berl) ; 99(5): 938-49, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25142040

ABSTRACT

N-3 polyunsaturated fatty acids (PUFA) are essential for foetal development. Hence, including n-3 PUFA in the sow diet can be beneficial for reproduction. Both the amount and form (precursor fatty acids vs. long chain PUFA) of supplementation are important in this respect. Furthermore, including n-3 PUFA in the diet can have negative effects, such as decreased arachidonic acid (ARA) concentration and increased oxidative stress. This study aimed to compare the efficacy to increase eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) concentrations in the piglet, when different concentrations of linseed oil (LO, source of precursor α-linolenic acid) or fish oil (FO, source of EPA and DHA) were included in the maternal diet. Sows were fed a palm oil diet or a diet including 0.5% or 2% LO or FO from day 45 of gestation until weaning. Linoleic acid (LA) was kept constant in the diets to prevent a decrease in ARA, and all diets were supplemented with α-tocopherol acetate (150 mg/kg) and organic selenium (0.4 mg/kg) to prevent oxidative stress. Feeding 0.5% LO or 0.5% FO to the sows resulted in comparable EPA concentrations in the 5-day old piglet liver, but both diets resulted in lower EPA concentrations than when 2% LO was fed. The highest EPA concentration was obtained when 2% FO was fed. The DHA level in the piglet liver could only be increased when FO, but not LO, was fed to the sows. The 2% FO diet had no advantage over the 0.5% FO diet to increase DHA in the piglet. Despite the constant LA concentration in the sow diet, a decrease in ARA could not be avoided when LO or FO were included in the diet. Feeding 2% FO to the sows increased the malondialdehyde concentration (marker for lipid peroxidation) in sow plasma, but not in piglets.


Subject(s)
Animal Feed/analysis , Diet/veterinary , Fatty Acids/metabolism , Fish Oils/pharmacology , Linseed Oil/pharmacology , Swine/physiology , Animals , Dietary Supplements , Dose-Response Relationship, Drug , Fatty Acids/chemistry , Female , Fish Oils/chemistry , Linseed Oil/chemistry , Oxidative Stress
7.
Animal ; 8(11): 1857-66, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25322791

ABSTRACT

This study aimed to investigate the effects and possible interactions of birth weight and n-3 polyunsaturated fatty acid (PUFA) supplementation of the maternal diet on the fatty acid status of different tissues of newborn piglets. These effects are of interest as both parameters have been associated with pre-weaning mortality. Sows were fed a palm oil diet or a diet containing 1% linseed, echium or fish oil from day 73 of gestation. As fish oil becomes a scarce resource, linseed and echium oil were supplemented as sustainable alternatives, adding precursor fatty acids for DHA to the diet. At birth, the lightest and heaviest male piglet per litter were killed and samples from liver, brain and muscle were taken for fatty acid analysis. Piglets that died pre-weaning had lower birth weights than piglets surviving lactation (1.27±0.04 v. 1.55±0.02 kg; P<0.001), but no effect of diet on mortality was found. Lower DHA concentrations were observed in the brain of the lighter piglets compared with their heavier littermates (9.46±0.05 v. 9.63±0.04 g DHA/100 g fatty acids; P=0.008), suggesting that the higher incidence of pre-weaning mortality in low birth weight piglets may be related to their lower brain DHA status. Adding n-3 PUFA to the sow diet could not significantly reduce this difference in DHA status, although numerically the difference in the brain DHA concentration between the piglet weight groups was smaller when fish oil was included in the sow diet. Independent of birth weight, echium or linseed oil in the sow diet increased the DHA concentration of the piglet tissues to the same extent, but the concentrations were not as high as when fish oil was fed.


Subject(s)
Birth Weight , Fatty Acids, Omega-3/metabolism , Plant Oils/metabolism , Sus scrofa/growth & development , Sus scrofa/metabolism , Animals , Brain Chemistry , Dietary Fats/metabolism , Dietary Supplements/analysis , Echium/chemistry , Linseed Oil/metabolism , Liver/chemistry , Male , Muscles/chemistry , Palm Oil
8.
J Anim Sci ; 91(7): 3253-64, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23658328

ABSTRACT

Echium oil (source of stearidonic acid) and linseed oil (source of α-linolenic acid) were evaluated as alternatives for fish oil in the diet of sows to increase the docosahexaenoic acid (DHA) status of the offspring. The hypothesis was that echium oil would be more efficient than linseed oil to increase the DHA concentration, as it bypasses the enzyme Δ6-desaturase. In addition, it was determined whether adding PUFA to the diet affected the plasma oxidative status. Sows were fed either a palm oil diet or a diet containing 1% linseed oil, echium oil, or fish oil from d 73 of gestation and during lactation (n = 16 per dietary treatment). Total oil concentrations in the diets were similar among dietary treatments. Blood samples were taken for fatty acid analysis and oxidative status of sows on d 73 and 93 of gestation and at parturition and the lightest and heaviest piglet per litter at birth and weaning. Colostrum was also sampled. No effect of diet was observed on total number of piglets born (13.7 ± 0.4), number of weaned piglets (10.8 ± 0.4), and gestation length (114.8 ± 0.2 d). Piglets from sows fed fish oil had lighter birth weights (1.41 ± 0.03 kg) than piglets from the linseed oil diet (1.54 ± 0.03 kg; P = 0.006), with no difference between the palm oil (1.45 ± 0.03 kg) and echium oil diet (1.49 ± 0.03 kg). Daily BW gain until weaning was less for piglets from sows fed the fish oil diet (214 ± 5 g) compared with piglets from sows fed the echium oil (240 ± 5 g; P < 0.001) or linseed oil diet (234 ± 5 g; P = 0.02). Compared with the palm oil diet, echium and linseed oil in the maternal diet increased the DHA concentration in the colostrum and the sow and piglet plasma to the same extent (1.1 to 1.4-fold; P < 0.001). On the fish oil diet, 20.7-fold, 10-fold, and 2.4-fold increases in DHA in colostrum, sow, and piglet plasma, respectively, were observed (P < 0.001). At 1% in the maternal diet, echium oil had, thus, no benefit over linseed oil and resulted in a twofold less DHA concentration in the plasma of piglets compared with fish oil. Including n-3 PUFA in the maternal diet did not affect oxidative status of the mother or the offspring.


Subject(s)
Echium/chemistry , Fatty Acids, Unsaturated/metabolism , Oxidative Stress/drug effects , Plant Oils/metabolism , Sus scrofa/physiology , Animal Nutritional Physiological Phenomena/drug effects , Animals , Blood Chemical Analysis/veterinary , Dietary Supplements/analysis , Docosahexaenoic Acids/metabolism , Fatty Acids, Unsaturated/administration & dosage , Fatty Acids, Unsaturated/blood , Female , Linseed Oil/administration & dosage , Linseed Oil/metabolism , Male , Maternal Nutritional Physiological Phenomena/drug effects , Plant Oils/administration & dosage , Sus scrofa/growth & development , alpha-Tocopherol/administration & dosage , alpha-Tocopherol/metabolism
9.
Reproduction ; 130(2): 251-9, 2005 Aug.
Article in English | MEDLINE | ID: mdl-16049163

ABSTRACT

The purpose of the present study was to identify a potential interference of bovine herpesvirus-1 (BoHV-1) with sperm-oocyte interactions during bovine in vitro fertilization. An inhibition of almost 70% of sperm-zona binding was observed when bovine cumulus-denuded oocytes were inseminated in the presence of 10(7) 50% tissue culture infective dose/ml BoHV-1. The inhibitory effect of BoHV-1 on sperm-zona binding was mediated by an interaction of the virus with spermatozoa, but not with oocytes. Treatment of spermatozoa with BoHV-1, however, did not affect sperm motility and acrosomal status. Antiserum against BoHV-1 prevented the virus-induced inhibition of sperm-zona binding, indicating that BoHV-1 itself affects the fertilization process. In order to investigate which BoHV-1 glycoprotein(s) are responsible for the virus-sperm interaction, BoHV-1 was treated with monoclonal antibodies against the viral glycoproteins gB, gC, gD and gH prior to insemination. Anti-gC completely prevented the inhibitory effect of BoHV-1 on sperm-zona binding, while anti-gD caused a reduction of this inhibition. Further evidence for the involvement of gC and gD in the virus-sperm interaction was provided by the fact that purified gC and gD decreased sperm-zona binding in a dose-dependent way with gC being more effective than gD. These results indicated that BoHV-1 inhibits bovine sperm-zona binding by interacting with spermatozoa. The binding of BoHV-1 to a spermatozoon is mediated by the viral glycoproteins gC and gD, and therefore seems to be comparable with the mechanisms of BoHV-1 attachment to its natural host cell.


Subject(s)
Herpesvirus 1, Bovine/physiology , Sperm-Ovum Interactions , Spermatozoa/virology , Acrosome Reaction , Animals , Antibodies, Monoclonal/pharmacology , Antigen-Antibody Reactions , Antigens, Viral/metabolism , Cattle , Female , Fertilization in Vitro , Male , Sperm Motility , Sperm-Ovum Interactions/drug effects , Staining and Labeling , Viral Envelope Proteins/immunology , Viral Proteins/immunology
10.
Theriogenology ; 64(3): 706-19, 2005 Aug.
Article in English | MEDLINE | ID: mdl-15946733

ABSTRACT

Until recently, canine semen assessment was routinely performed by conventional light microscopic techniques. The limitations of these methods include subjectivity, variability, the small number of spermatozoa analyzed, and poor correlation with fertilizing potential. The last decade, several new in vitro techniques have been introduced for canine semen assessment that enable a more detailed evaluation of several sperm characteristics. Numerous fluorescent staining techniques have been developed for the evaluation of specific sperm characteristics and functions, including plasma membrane integrity, capacitation status and the acrosome reaction. By combining fluorescent stains, several functional sperm characteristics can be assessed simultaneously. Moreover, by means of flow cytometry, large numbers of fluorescently labelled spermatozoa can be analysed in a short interval. Following thorough standardization and validation, computer-assisted sperm analysis systems provide objective and detailed information on various motility characteristics and morphometric dimensions that cannot be identified by conventional light microscopic semen analysis. In vitro assays, evaluating the capacity of canine spermatozoa to bind to the zona pellucida or oviductal explants, or to penetrate the oocyte, provide additional information on canine gamete interaction that may be useful in predicting the fertilizing potential of spermatozoa. Although substantial improvements have been made in canine semen assessment, surprisingly few parameters were correlated with in vivo fertility. Therefore, further research is required to determine which sperm characteristics are of clinical value for predicting the in vivo fertility in dogs.


Subject(s)
Dogs , Fertility , Semen/physiology , Spermatozoa/physiology , Acrosome Reaction , Animals , Autoanalysis/veterinary , Computers , Female , Fluorescent Dyes , Male , Sperm Capacitation , Sperm Motility , Sperm-Ovum Interactions , Spermatozoa/ultrastructure
11.
Mol Reprod Dev ; 68(4): 492-9, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15236335

ABSTRACT

In the present study, efforts were made towards identifying carbohydrates and glycoproteins involved in bovine in vitro fertilization (IVF). In vitro matured cumulus-oocyte complexes (COCs) were inseminated in the presence of a variety of carbohydrates and glycoproteins to determine which glycoconjugates act as competitive inhibitors of oocyte penetration. Among the carbohydrates and glycoproteins tested, D-mannose, fucoidan, dextran sulfate, and fibronectin were the most potent inhibitors of oocyte penetration (90% or more inhibition), while L-fucose and vitronectin inhibited the penetration rate to a lesser extent (around 50% inhibition). Other carbohydrates caused less than 40% inhibition (i.e., D-galactose, N-acetyl-D-galactosamine, D-fucose, and sialic acid) or were not effective as inhibitors of oocyte penetration (i.e., mannan, N-acetyl-D-glucosamine, dextran, and heparan sulfate). Heparin was the only carbohydrate that significantly increased the penetration rate. To exclude a possible toxic effect on spermatozoa, sperm motility was evaluated over time by means of computer-assisted sperm analysis in the presence of carbohydrates and/or glycoproteins that inhibited the penetration rate with 40% or more. L-fucose, dextran sulfate, and vitronectin did not significantly influence total and progressive sperm motility, whereas D-mannose, fucoidan, and fibronectin caused a significant, but slight reduction in both motility parameters. These results are indicative for the involvement of D-mannose, L-fucose, fucoidan, dextran sulfate, fibronectin, and vitronectin in bovine IVF.


Subject(s)
Carbohydrate Metabolism , Fertilization in Vitro/veterinary , Proteins/metabolism , Animals , Cattle , Cell Adhesion/drug effects , Cell Adhesion/physiology , Female , Fertilization in Vitro/methods , Fibronectins/pharmacology , Glycoproteins/pharmacology , Humans , Male , Mice , Monosaccharides/pharmacology , Sperm Motility/drug effects , Sperm-Ovum Interactions/drug effects , Sperm-Ovum Interactions/physiology , Spermatozoa/physiology
12.
Reprod Domest Anim ; 37(3): 144-51, 2002 Jun.
Article in English | MEDLINE | ID: mdl-12071888

ABSTRACT

CONTENTS: Fertilization encompasses a series of different steps which have to be performed in a well-orchestrated way to create a new individual. They include sperm capacitation, sperm binding and penetration of the zona pellucida, traversing the perivitelline space, binding and fusion with the oolemma, activation of the oocyte and decondensation of the sperm head to form the male pronucleus. In most mammalian species, cumulus cells surround the oocyte at the time of fertilization. Removal of the cumulus oophorus at this point of time often leads to a drop in fertilization rates. It is not yet known how cumulus cells interact with the oocyte or with spermatozoa to promote fertilization. There are different possibilities: 1 cumulus cells cause mechanical entrapment of spermatozoa and guide hyperactivated spermatozoa towards the oocyte, while preventing abnormal spermatozoa to enter the cumulus matrix; 2 cumulus cells create a micro-environment for the spermatozoa which favours their capacitation and penetration into the oocyte; 3 cumulus cells prevent changes in the oocyte which are unfavourable for normal fertilization; these changes can be located in the zona pellucida or in the cytoplasm. In this review, studies in several species are listed to prove the importance of these three cumulus cell functions and the current lines of research are highlighted. Moreover, different ways to improve in vitro fertilization of bovine cumulus-denuded oocytes are discussed.


Subject(s)
Fertilization in Vitro/veterinary , Fertilization/physiology , Granulosa Cells/physiology , Oocytes/cytology , Spermatozoa/physiology , Animals , Female , Male , Mammals , Oocytes/physiology , Sperm Capacitation , Sperm-Ovum Interactions/physiology
13.
IEEE Trans Biomed Eng ; 36(7): 693-704, 1989 Jul.
Article in English | MEDLINE | ID: mdl-2744793

ABSTRACT

Silicon micromachining and thin-film technology have been employed to fabricate iridium stimulating arrays which can be used to excite discrete volumes of the central nervous system. Silicon multichannel probes with thicknesses ranging from 1 to 40 microns and arbitrary two-dimensional shapes can be fabricated using a high-yield, circuit-compatible process. Iridium stimulating sites are shown to have similar characteristics to iridium wire electrodes. Accelerated pulse testing with over 8 million 100 microA biphasic current pulses on 8000 microns 2 sites has demonstrated the long-term stability of iridium and activated iridium sites. In vivo tests have been performed in the central auditory pathways to demonstrate neural activation using the devices. These tests show a selective activation both as a function of site separation and site size.


Subject(s)
Auditory Pathways/physiology , Electric Stimulation/instrumentation , Microelectrodes , Animals , Equipment Design , Guinea Pigs , Iridium , Materials Testing , Silicon
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