scholarly journals Transmittance measurement of the in vivo human eye with a double-pass system

2021 ◽  
Vol 51 (1) ◽  
Author(s):  
Roberto Sánchez ◽  
Aníbal De Paul ◽  
Francisco Burgos-Fernández ◽  
Meritxell Vilaseca ◽  
Jaume Pujol ◽  
...  
Keyword(s):  
Artificial Eye ◽  
Double Pass ◽  
Pass System ◽  
Iris Color ◽  
Linear Behavior ◽  
Group A ◽  
The Media ◽  
Ocular Media ◽  
Group B

Purpose: To develop a methodology based on a double-pass system to obtain information about the transmittance of ocular media. Methods: The procedure consists of recording double-pass images at different powers of a laser diode of 780 nm and determining the scattering in an area between 25–35 arcmin of each image. The scattering showed linear behavior in respect to the irradiance of the laser, and the slope of the linear fit was proportional to the transmittance squared of the media evaluated. An artificial eye with different filters was tested first. Then, fifteen subjects with clear ocular media were divided into two groups: ten subjects classified by the iris color were recruited for the measurements of an ocular transmittance index and the estimation of the transmittance (group A), and another five subjects were selected for measurements with neutral filters (group B). Results: The measurements performed in group A presented a mean transmittance of 42.95%. No differences in the transmittance were found between subjects with different iris color (p = 0.154). Measurements in group B showed a good correlation (r = 0.959, p < 0.001) between the expected and the measured value for the transmittance. Conclusion: We proposed and evaluated a method to determine the transmittance of the eye in vivo using the double-pass system.

Measurement of ocular transmission in living human eyes with a double-pass system

2019 ◽  
Author(s):  
Roberto F. Sánchez ◽  
Aníbal G. de Paul ◽  
Francisco J. Burgos-Fernández ◽  
Meritxell Vilaseca ◽  
Jaume Pujol ◽  
...  
Keyword(s):  
Optical Quality ◽  
Artificial Eye ◽  
Double Pass ◽  
Pass System ◽  
Linear Behavior ◽  
The Media ◽  
Linear Fit ◽  
Human Eyes

AbstractPurposeTo develop a methodology based on a double-pass system to obtain useful information about the transmission of ocular media, performing noninvasive measures in vivo.MethodsThis noninvasive procedure consists of recording double-pass images at different voltages of a laser diode of 780 nm and the determination of the scattering in an area between 25 and 35 arc minutes of each image.ResultsOcular scattering showed a linear behavior respect to the voltage of the laser and the slope of the linear fit was proportional to the transmittance squared of the media evaluated. The relationship between the ocular light scattering of the images and the transmittance values of several filters located into an artificial eye was used as a calibration function. The measurements performed in a group of ten subjects with ages between 25 and 45 years old presented a mean direct transmittance of the whole eye including retina of 42.7 %, which agrees with the bibliography. No differences between dark eyes and light eyes were found.ConclusionWe have developed a method to determine the transmittance of the human eye in vivo for a wavelength of 780 nm using the double-pass method, commonly used for the determination of the optical quality of an eye.

Training-induced alterations of the in vivo force-velocity relationship of human muscle

1981 ◽  
Vol 51 (3) ◽  
pp. 750-754 ◽  
Author(s):  
V. J. Caiozzo ◽  
J. J. Perrine ◽  
V. R. Edgerton
Keyword(s):  
Training Group ◽  
Knee Extension ◽  
Knee Extensors ◽  
Velocity Relationship ◽  
Slow Velocity ◽  
Group A ◽  
Force Velocity ◽  
Group B ◽  
Relationship Of

Seventeen male and female subjects (ages 20–38 yr) were tested pre- and posttraining for maximal knee extension torque at seven specific velocities (0, 0.84, 1.68, 2.51, 3.35, 4.19, and 5.03 rad . s-1) with an isokinetic dynamometer. Maximal knee extension torques were recorded at a specific joint angle (0.52 rad below the horizontal plane) for all test speeds. Subjects were randomly assigned to one of three experimental groups: group A, control, n = 7; group B, training at 1.68 rad . s-1, n = 5; or group C, training at 4.19 rad . s-1, n = 5. Subjects trained the knee extensors by performing two sets of 10 single maximal voluntary efforts three times a week for 4 wk. Before training, each training group exhibited a leveling-off of muscular tension in the slow velocity-high force region of the in vivo force-velocity relationship. Training at 1.68 rad . s-1 resulted in significant (P less than 0.05) improvements at all velocities except for 5.03 rad . s-1 and markedly affected the leveling-off in the slow velocity-high force region. Training at 4.19 rad . s-1 did not affect the leveling-off phenomenon but brought about significant improvements (P less than 0.05) at velocities of 2.51, 3.35, and 4.19 rad . s-1. The changes seen in the leveling-off phenomenon suggest that training at 1.68 rad . s-1 might have brought about an enhancement of motoneuron activation.

scholarly journals Photopolymerizable Injectable Cartilage Mimetic Hydrogel for the Treatment of Focal Chondral Lesions: A Proof of Concept Study in a Rabbit Animal Model

2018 ◽  
Vol 47 (1) ◽  
pp. 212-221 ◽  
Author(s):  
Cecilia Pascual-Garrido ◽  
Elizabeth A. Aisenbrey ◽  
Francisco Rodriguez-Fontan ◽  
Karin A. Payne ◽  
Stephanie J. Bryant ◽  
...  
Keyword(s):  
Animal Model ◽  
Chondrogenic Differentiation ◽  
Osteochondral Lesions ◽  
Chondral Defect ◽  
Group A ◽  
Group B ◽  
Safranin O

Background: In this study, we investigate the in vitro and in vivo chondrogenic capacity of a novel photopolymerizable cartilage mimetic hydrogel, enhanced with extracellular matrix analogs, for cartilage regeneration. Purpose: To (1) determine whether mesenchymal stem cells (MSCs) embedded in a novel cartilage mimetic hydrogel support in vitro chondrogenesis, (2) demonstrate that the proposed hydrogel can be delivered in situ in a critical chondral defect in a rabbit model, and (3) determine whether the hydrogel with or without MSCs supports in vivo chondrogenesis in a critical chondral defect. Study Design: Controlled laboratory study. Methods: Rabbit bone marrow–derived MSCs were isolated, expanded, encapsulated in the hydrogel, and cultured in chondrogenic differentiation medium for 9 weeks. Compressive modulus was evaluated at day 1 and at weeks 3, 6, and 9. Chondrogenic differentiation was investigated via quantitative polymerase reaction, safranin-O staining, and immunofluorescence. In vivo, a 3 mm–wide × 2-mm-deep chondral defect was created bilaterally on the knee trochlea of 10 rabbits. Each animal had 1 defect randomly assigned to be treated with hydrogel with or without MSCs, and the contralateral knee was left untreated. Hence, each rabbit served as its own matched control. Three groups were established: group A, hydrogel (n = 5); group B, hydrogel with MSCs (n = 5); and group C, control (n = 10). Repair tissue was evaluated at 6 months after intervention. Results: In vitro, chondrogenesis and the degradable behavior of the hydrogel by MSCs were confirmed. In vivo, the hydrogel could be delivered intraoperatively in a sterile manner. Overall, the hydrogel group had the highest scores on the modified O’Driscoll scoring system (group A, 17.4 ± 4.7; group B, 13 ± 3; group C, 16.7 ± 2.9) ( P = .11) and showed higher safranin-O staining (group A, 49.4% ± 20%; group B, 25.8% ± 16.4%; group C, 36.9% ± 25.2%) ( P = .27), although significance was not detected for either parameter. Conclusion: This study provides the first evidence of the ability to photopolymerize this novel hydrogel in situ and assess its ability to provide chondrogenic cues for cartilage repair in a small animal model. In vitro chondrogenesis was evident when MSCs were encapsulated in the hydrogel. Clinical Relevance: Cartilage mimetic hydrogel may offer a tissue engineering approach for the treatment of osteochondral lesions.

scholarly journals RADIOLOGICAL STUDY OF MEGACOLON IN TRYPANOSOMA CRUZI INFECTED RATS

2018 ◽  
Vol 31 (1) ◽  
Author(s):  
Carlos Edmundo Rodrigues FONTES ◽  
Ana Paula de ABREU ◽  
Aretuza Zaupa GASPARIM
Keyword(s):  
Trypanosoma Cruzi ◽  
Wistar Rats ◽  
In Vivo Studies ◽  
Proposed Model ◽  
Male Wistar Rats ◽  
Group A ◽  
Time Of Infection ◽  
Group B ◽  
Digital Caliper

ABSTRACT Background: Researches on Chagas disease still use several animals and rats, due to size and susceptibility were preferred by many authors. Aim: To develop an experimental model of megacolon in rats inoculated with the strain Y of Trypanosoma cruzi. Methods: Thirty male Wistar rats were distributed in three groups inoculated with different inoculants: Group A: 600000, Group B: 1000000 and Group C: 1500000 blood trypomastigotes of T. cruzi. Animals were sedated intramuscularly at zero inoculation time (T0) and 60 days after inoculation (T60), to perform the barium enema in order to evaluate the dilatation of the different segments of colon in a comparative study of the measurements obtained, using a digital caliper. Evidence of infection was performed by blood smear collected from the animal’s tail 18 days after inoculation with observation of blood forms. Results: Comparing the intestinal diameter of the inoculated animals with 60,0000 trypomastigotes in the T0 of infection with T60 days after the inoculation, significant dilatation was observed between the proximal, medial and distal segments (p<0.01), indicating the establishment of the megacolon model. In addition, comparing intestinal diameter between the different segments, with in the T0 of infection and the T60 after inoculation, significant alterations were observed (p<0.05). Conclusion: The proposed model was possible for in vivo studies of alterations due to infection by T. cruzi and functional alterations of the colon. In addition, the changes manifested in the colon are not directly proportional to the size of the inoculum, but to the time of infection that the animals were submitted, since the animals inoculated with 60,0000 blood forms were the ones which presented the most significant alterations.

Treatment of bone metastases with dichloromethylene bisphosphonate.

1992 ◽  
Vol 10 (4) ◽  
pp. 591-598 ◽  
Author(s):  
G Francini ◽  
S Gonnelli ◽  
R Petrioli ◽  
F Conti ◽  
P Paffetti ◽  
...  
Keyword(s):  
Bone Metastases ◽  
Serum Alkaline Phosphatase ◽  
Urinary Calcium ◽  
Bone Lesions ◽  
Osteolytic Lesions ◽  
Concurrent Use ◽  
Pathologic Fractures ◽  
Group A ◽  
Group B

PURPOSE The study was undertaken to evaluate the effects of dichloromethylene bisphosphonate (Cl2MDP) on osteolytic and osteoblastic bone lesions from a variety of tumoral primary sites and to investigate the in vivo mechanism underlying the action of this drug. PATIENTS AND METHODS Seventy-six patients participated in the current study: 59 had predominantly osteolytic lesions and 17 osteoblastic metastases. Sixteen patients had hypercalcemia. All of the patients received 300 mg of Cl2MDP intravenously (IV) for 7 days and then 200 mg of Cl2MDP intramuscularly (IM) for 14 days. Biochemical parameters were measured in the patients before the start of treatment and 3, 7, 14, and 21 days after beginning treatment. After the withdrawal of parenteral Cl2MDP, 59 patients with predominantly osteolytic lesions were then randomized to receive chemotherapy alone (group A, 29 cases) or chemotherapy plus Cl2MDP given at an oral dose of 1,200 mg/d (group B, 30 cases). RESULTS Serum calcium (Ca), urinary calcium (UCa) phosphate (UPO4), and hydroxyproline (HOP) excretion levels significantly decreased in all patients, whereas no significant changes occurred in serum alkaline phosphatase (AlkPh) and bone Gla-protein (BGP) levels. In 56 patients with painful bone lesions, a progressive analgesic effect was observed mainly between day 7 and day 14. In patients with predominantly osteoblastic metastases, the Cl2MDP treatment led to a more evident hypocalcemia and an increase in both AlkPh and BGP. However, in the majority of these patients the hypocalcemia was corrected by the concurrent use of effective cytotoxic treatments capable of reducing osteoblast stimulation. During 6 months of follow-up, two pathologic fractures occurred in patients of group A, and none occurred in patients of group B. CONCLUSIONS We conclude that Cl2MDP was effective in patients presenting bone metastases with and without hypercalcemia. Care should be taken particularly in those patients with mixed metastases when the sclerotic component is predominant, as the drug may enhance the possibility of hypocalcemia, which is generally corrected by effective cytotoxic drugs. Therefore, Cl2MDP can be considered a valuable support in the treatment of bone metastases.

scholarly journals Magnetic resonance imaging and computed tomography of equine cheek teeth and adjacent structures: comparative study of image quality in horses in vivo, post-mortem and frozen-thawed

2019 ◽  
Vol 61 (1) ◽  
Author(s):  
Christin Röttiger ◽  
Maren Hellige ◽  
Bernhard Ohnesorge ◽  
Astrid Bienert-Zeit
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Post Mortem ◽  
Mr Images ◽  
Adjacent Structures ◽  
Group A ◽  
Group B ◽  
The Impact ◽  
Ct And Mri

Abstract Background The use of cadavers for radiology research methodologies involving subjective image quality evaluation of anatomical criteria is well-documented. The purpose of this method comparison study was to evaluate the image quality of dental and adjacent structures in computed tomography (CT) and high-field (3 T) magnetic resonance (MR) images in cadaveric heads, based on an objective four-point rating scale. Whilst CT is a well-established technique, MR imaging (MRI) is rarely used for equine dental diagnostics. The use of a grading system in this study allowed an objective assessment of CT and MRI advantages in portraying equine cheek teeth. As imaging is commonly performed with cadaveric or frozen and thawed heads for dental research investigations, the second objective was to quantify the impact of the specimens’ conditions (in vivo, post-mortem, frozen-thawed) on the image quality in CT and MRI. Results The CT and MR images of nine horses, focused on the maxillary premolar 08s and molar 09s, were acquired post-mortem (Group A). Three observers scored the dental and adjacent tissues. Results showed that MR sequences gave an excellent depiction of endo- and periodontal structures, whereas CT produced high-quality images of the hard tooth and bony tissues. Additional CT and MRI was performed in vivo (Group B) and frozen-thawed (Group C) in three of these nine horses to specify the condition of the best specimens for further research. Assessing the impact of the specimens’ conditions on image quality, specific soft tissues of the maxillary 08s and 09s including adjacent structures (pulps, mucosa of the maxillary sinuses, periodontal ligament, soft tissue inside the infraorbital canal) were graded in group B and C and analysed for significant differences within CT and MR modalities in comparison to group A. Results showed that MRI scores in vivo were superior to the post-mortem and frozen-thawed condition. Conclusions On comparing the imaging performance of CT and MRI, both techniques show a huge potential for application in equine dentistry. Further studies are needed to assess the clinical suitability of MRI. For further research investigations it must be considered, that the best MR image quality is provided in live horses.

Effects of Removal of the Statoacoustic Ganglion Complex upon the Growing Otocyst

1976 ◽  
Vol 85 (6_suppl) ◽  
pp. 2-32 ◽  
Author(s):  
Thomas R. Van De Water
Keyword(s):  
Organ Culture ◽  
Inner Ear ◽  
Nerve Fibers ◽  
Trophic Effect ◽  
Group A ◽  
Sensory Structures ◽  
Statoacoustic Ganglion ◽  
Group B

An experiment was designed to answer the question as to whether or not the neural elements of the statoacoustic ganglion complex have a trophic effect upon the histodifferentiation of the sensory structures of the embryonic mouse inner ear anlage as it develops in vitro. The embryonic inner ear anlage with associated otic mesenchyme and statoacoustic ganglion complex was excised from 11, 12, and 13-day CBA/C57 mouse embryos. The inner ear explants of each gestational age group were further divided into two groups: the first group “A” (with) statoacoustic ganglion was explanted to the organ culture system without further surgical intervention; the second group “B” (without) statoacoustic ganglion underwent further surgical manipulation during which their statoacoustic ganglion complexes were dissected away prior to explantation to in vitro. The explanted embryonic inner ears were allowed to develop in organ culture until the equivalent of gestation day 21 in vivo was reached for each group; then all cultures were fixed and histologically processed and stained by a nerve fiber stain, in combination with a stain for glucoprotein membranes. Each specimen was code labeled and scored for histodifferentiation of sensory structures. Light microscopic observations confirmed that in group “A” cultures, statoacoustic ganglion neurons and their nerve fibers were present in association with the developed sensory structures; neither ganglion cell neurons nor their nerve fibers were found to be present in the sensory structures that developed in the group “B” organ culture specimens. Quantification revealed no consistent trend of greater occurrence of any sensory structure in the groups of explants analyzed. The presence of such a trend would have signified the probable existence of a trophic effect of the statoacoustic ganglion neural elements upon development of inner ear sensory structures in the group “A” explants of the 11, 12, and 13-day embryo inner ear organ culture specimens when compared to the aganglionic group “B” cultures. Microscopic comparison of the sensory structures and their sensory hair cells that developed in the organ cultures revealed no differences in the quality of the histodifferentiation of either group “A” or group “B” explants. A base to apex pattern of histodifferentiation of the organ of Corti sensory structures, which has been described to occur in vivo, was noted to occur in the in vitro developed cochlear ducts of all of the explanted inner ears without respect to whether neural elements were present (“A”) or absent (“B”) during development. It was concluded from the quantification of histodifferentiation data and the above observation on the pattern of differentiation of Corti's organ that no trophic effect of neural elements of the statoacoustic ganglion complex influencing the histodifferentiation of sensory structures of 11, 12, and 13-gestation day mouse embryo inner ear explants as they differentiate in vitro could be demonstrated.

scholarly journals A Comparative in vivo Study of Semi-constrained and Unconstrained Cervical Artificial Disc Prostheses

2019 ◽  
Vol 184 (Supplement_1) ◽  
pp. 637-643 ◽  
Author(s):  
Hoon Choi ◽  
Jamie L Baisden ◽  
Narayan Yoganandan
Keyword(s):  
In Vivo Model ◽  
Artificial Disc ◽  
Disc Space ◽  
Cervical Arthroplasty ◽  
Healthy Female ◽  
Different Types ◽  
Group A ◽  
Group B ◽  
Anterior Migration

Abstract Purpose The objective of this study is to directly compare different types of cervical artificial disc implants using an in vivo model capable of simulating the axial load on a neck that is similar to the human neck. Methods Cervical arthroplasty was performed at C3-4 in 14 healthy female adult Alpine goats. The goats were divided into three groups. Group A received Bryan (unconstrained one-piece design); Group B received ProDisc-C (semi-constrained two-piece design); and Group C received Mobi-C (unconstrained three-piece design) artificial discs. The goats were monitored in a veterinary unit for 6 months with radiography at regular intervals. Results Each goat tolerated cervical arthroplasty well and had satisfactory placement of their implant per intra-operative radiography. Implants monitored in Group A demonstrated no migration. One out of five implants in Group B experienced anterior migration at 3 months. In Group C, anterior migration and disintegration occurred in all four implants, with migration occurring during the first postoperative week in three implants and after 5 weeks in the fourth. Conclusions Unconstrained multi-piece artificial cervical discs may be prone to anterior migration and extrusion out of the disc space. This outcome deserves attention in individuals with a hypermobile neck and/or an occupation involving the use of a head-supported mass, such as helmets.

Chemopreventive Effect of a Novel Nutrient Mixture on Lung Tumorigenesis Induced by Urethane in Male A/J Mice

2009 ◽  
Vol 95 (4) ◽  
pp. 508-513 ◽  
Author(s):  
M Waheed Roomi ◽  
Nusrath W Roomi ◽  
Tatiana Kalinovsky ◽  
Matthias Rath ◽  
Aleksandra Niedzwiecki
Keyword(s):  
Body Weight ◽  
Control Diet ◽  
Test Group ◽  
Lung Tumors ◽  
Mouse Lung ◽  
Lung Tumorigenesis ◽  
Group A ◽  
The Mean ◽  
Group B

Aims and background Lung cancer, a leading cause of cancer death, is associated with exposure to inhalation carcinogens, most commonly those found in tobacco smoke. We investigated the in vivo effect of dietary supplementation with a nutrient mixture containing lysine, proline, arginine, ascorbic acid, green tea extract, N-acetyl cysteine, selenium, copper and manganese on the development of urethane-induced lung tumors in male A/J mice. Methods After one week of isolation, seven-week-old male A/J mice (n = 25) weighing 17–19 g were randomly divided into three groups: group A (n = 5), group B (n = 10), and group C (n = 10). Mice in groups B and C were each given a single intraperitoneal injection of urethane (1 mg/g body weight) in saline, whereas group A mice received an injection of saline alone. Groups A and B were fed a regular diet, whereas group C was fed the same diet supplemented with 0.5% nutrient mixture. After 20 weeks, mice were sacrificed, lungs were excised and weighed, and tumors were counted and processed for histology. Results Urethane-challenged mice developed tumors. However, the mean number of tumors and the mean lung weights in the mice on the supplemented diet were significantly reduced, by 49% (P <0.0001) and 18% (P = 0.0025), respectively, compared to mice on the control diet. We observed neither significant differences in body weight gains nor in diet consumption among the mice. Pulmonary lesions were morphologically similar for both the groups (adenomas), but lesions were smaller in the test group. Conclusions The results suggest that nutrient mixture has inhibitory potential on the development of mouse lung tumors induced by urethane

scholarly journals Effects of Light Activation, Agent Concentration, and Tooth Thickness on Dental Sensitivity After Bleaching

2013 ◽  
Vol 38 (5) ◽  
pp. 467-476 ◽  
Author(s):  
G Moncada ◽  
D Sepúlveda ◽  
K Elphick ◽  
M Contente ◽  
J Estay ◽  
...  
Keyword(s):  
Analysis Of Covariance ◽  
Light Activation ◽  
Cervical Lesions ◽  
Tooth Sensitivity ◽  
Dental Bleaching ◽  
Anterior Teeth ◽  
Group A ◽  
Group B ◽  
The Relationship

SUMMARY Examining three bleaching systems, this in vivo clinical trial evaluated the relationship among tooth sensitivity, light activation, and agent concentration, and it correlated dental sensitivity with tooth thickness. Materials and Methods: Eighty-seven volunteer patients were included. Inclusion criteria were the presence of anterior teeth without restorations as well as the absence of a previous bleaching experience and absence of noncarious cervical lesions or dental pain. Exclusion criteria included pregnancy or breastfeeding, a maximum of TF3 hypoplasia, tetracycline-fluorosis stains, malpositioned teeth, orthodontic treatment, periodontal disease, and/or analgesic/anti-inflammatory intake. Patients were randomly assigned to three bleaching groups: Group A (n=25) was treated with 15% H2O2 and nitrogenous-titanium-dioxide and was light activated (Lase Peroxide Lite, DMC, SaoCarlos, Sao Paulo, Brazil); Group B (n=27) was treated with 35% H2O2 and was light activated (Lase Peroxide Sensy, DMC); and Group C (n=35) was treated with 35% H2O2 (White Gold Office, Dentsply, 38West Clark Ave., Milford, USA) without light activation. Tooth sensitivity (TS) was self-reported by the patients using the visual analog scale (VAS) at baseline (TS0), immediately after treatment (TSI), and at seven days after treatment (TS7). In 46 patients, tooth thickness was determined by computed tomography. TS0, TSI, and TS7 were compared between the A and B groups to determine the effect of concentration and between the B and C groups to determine the effect of light using analysis of covariance. The correlation between tooth thickness and TSI was determined by Spearman Rho test (SPSS 15). Results: Eighty-seven patients were evaluated at baseline, and 61 were evaluated at seven days. Separated by groups, tooth sensitivity, expressed as VAS value at the time points TS0, TSI, and TS7, respectively, were as follows: Group A: 13.76 ± 13.53, 24.40 ± 25.24, and 5.94 ± 5.5; Group B: 15.07 ± 18.14, 42.4 ± 31.78, and 8.68 ± 17.99; and Group C: 10.80 ± 14.83, 31.51 ± 29.34, and 7.24 ± 9.2. Group A showed significantly lower tooth sensitivity than group B at TSI (p=0.032). No differences were observed in the tooth sensitivities between groups B and C. No correlation was encountered between tooth thickness and tooth sensitivity immediately after treatment (Rho=−0.088, p=0.563). The median tooth thickness was 2.78 ± 0.21 mm. Conclusions: Increases in the concentration of bleaching agents directly affect tooth sensitivity, and LED/laser activation and tooth thickness are not correlated with tooth sensitivity after dental bleaching.

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