Analysis In Rabbits Research Articles

Fabrication of β-cyclodextrin-based microgels for enhancing solubility of Terbinafine: An in-vitro and in-vivo toxicological evaluation

Abstract Solubility enhancement of poorly aqueous-soluble drugs, like Terbinafine (TBN), is a critical challenge in formulating effective dosage forms. This study focused on developing β-cyclodextrin (β-CD) and polyacrylamide (PAM)-based microgels to address the solubility issue of TBN, classified as a biopharmaceutics classification system class II drug. The microgels were crafted through free radical polymerization, employing methylene bisacylamide as a cross-linker and methacrylic acid as a monomer, initiated by ammonium persulfate. Comprehensive characterizations, including Fourier transform infrared, thermo-gravimetric analysis, differential scanning calorimetry, scanning electron microscopy, powder X-ray diffractometry analysis, Zeta size, and Zeta potential, were conducted. In vitro studies, such as drug release and swelling, were performed at pH 1.2. Toxicity analysis in rabbits revealed zero toxicity. These β-CD/PAM microgels successfully enhanced the solubility of TBN.

CHANGES IN MORPHOLOGICAL PARAMETERS OF BLOOD IN RABBITS DURING GASTRIC SURGERY

The study of the reaction of the inflammatory process and its nature, depending on the use of drug treatment and without it, was carried out using a study of general blood analysis in rabbits after gastric surgery. In this study, we determined changes in the leukocyte formula of rabbits after surgery. The research material was a general blood test, namely the leukocyte formula of two groups of rabbits, each of which consisted of 5 heads. A general blood analysis study was performed on a Mindrai BC-5000 device, but white blood cells were counted manually, using a Goryaev chamber and Türk's solution, as well as a Sigeta Biogenic LED microscope (China). The leukocyte formula was calculated manually according to the Schilling formula and preliminary staining of blood smears according to the Romanovsky-Giemz method. In the study, the course of the inflammatory process in the postoperative period of rabbits was determined, which was characterized by general leukocytosis on the 3.7th day, due to an increase in neutrophils, and a left-sided followed by a right-sided shift in the leukocyte formula. According to the results of the study, it was found that the course of the inflammatory process was less pronounced in the group that received treatment.Leukocytosis with changes in the leukocyte formula of the first group of rabbits stabilized on the 10th day, in contrast to the second group that did not receive treatment. The course of the leukocytosis process was due to lymphocytopenia and an increase in the level of neutrophils, which alternated due to a previous increase in rod-shaped neutrophils, followed by a period of their decrease and an increase in the number of segmented neutrophils, which indicated the physiological course of the inflammatory process and the absence of the development of a septic process in the bodies of experimental animals.

Vaccination of Rabbits with a Cholera Conjugate Vaccine Comprising O-Specific Polysaccharide and a Recombinant Fragment of Tetanus Toxin Heavy Chain Induces Protective Immune Responses against Vibrio cholerae O1.

There is a need for next-generation cholera vaccines that provide high-level and durable protection in young children in cholera-endemic areas. A cholera conjugate vaccine (CCV) is in development to address this need. This vaccine contains the O-specific polysaccharide (OSP) of Vibrio cholerae O1 conjugated via squaric acid chemistry to a recombinant fragment of the tetanus toxin heavy chain (OSP:rTTHc). This vaccine has been shown previously to be immunogenic and protective in mice and found to be safe in a recent preclinical toxicological analysis in rabbits. We took advantage of excess serum samples collected as part of the toxicological study and assessed the immunogenicity of CCV OSP:rTTHc in rabbits. We found that vaccination with CCV induced OSP-, lipopolysaccharide (LPS)-, and rTTHc-specific immune responses in rabbits, that immune responses were functional as assessed by vibriocidal activity, and that immune responses were protective against death in an established virulent challenge assay. CCV OSP:rTTHc immunogenicity in two animal model systems (mice and rabbits) is encouraging and supports further development of this vaccine for evaluation in humans.

The Interplay of Raloxifene and Sonochemical Bio-Oss in Early Maxillary Sinus Bone Regeneration: A Histological and Immunohistochemical Analysis in Rabbits.

The study aimed to assess the efficacy of using Raloxifene with ultrasonic processing to enhance Bio-Oss®, a bone graft substitute, for maxillary sinus bone height reconstruction. A total of 24 rabbit maxillary sinuses were distributed into three groups, each receiving different treatments: Bio-Oss® only, sonicated Bio-Oss, and sonicated Bio-Oss® with Raloxifene. Surgical procedures and subsequent histomorphometric and immunohistochemistry analyses were conducted to evaluate the bone formation, connective tissue, and remaining biomaterial, as well as the osteoblastic differentiation and maturation of collagen fibers. Results indicated that the sonicated Bio-Oss® and Bio-Oss® groups showed similar histological behavior and bone formation, but the Raloxifene group displayed inflammatory infiltrate, low bone formation, and disorganized connective tissue. The statistical analysis confirmed significant differences between the groups in terms of bone formation, connective tissue, and remaining biomaterial. In conclusion, the study found that while sonicated Bio-Oss® performed comparably to Bio-Oss® alone, the addition of Raloxifene led to an unexpected delay in bone repair. The findings stress the importance of histological evaluation for accurate bone repair assessment and the necessity for further investigation into the local application of Raloxifene. Future research may focus on optimizing bone substitutes with growth factors to improve bone repair.

The impact of Lidocaine gel on TNF-α expression in surgically induced oral mucosal ulcers: an immunohistochemical analysis in rabbits

Background: Besides being a local anesthetic agent lidocaine is a promising anti-inflammatory agent with limited studies on its effect on the mucosa. Aim: Assess the anti-inflammatory effect of lidocaine following surgical induction wound in the oral mucosa as assessed by tumor necrosis factor-α (TNF-α) expression. Materials and methods: The study was conducted on 32 albino rabbits that were categorized into 2 equal groups of 16 rabbits: In the control group an oral wound was surgically induced and left without treatment and in the treatment group an oral wound was surgically induced and received topical Lidocaine gel. Euthanasia of animals was carried out on days 1, 3, 7, and 10, and sample sites were processed for histopathological and immunohistochemical staining for TNF-α. Results: In the histological observations, it was noticed that the healing process was more rapid and convenient in the test group compared to the control group. For Immunohistochemical assessment, the TNF-α started to express clearly at 1 day and gradually decreased and disappeared at 10 days with a superior effect of the lidocaine group over the control group. Conclusion: Lidocaine seems to have anti-inflammatory reactions by lowering TNF-α levels and preventing the production of pro-inflammatory cytokines.

Sinus Mucosal Damage Triggered by Synthetic or Xenogeneic Bone Substitutes: A Histological Analysis in Rabbits.

Background: It has been shown in rabbit models that the sinus mucosa in contact with graft particles might experience a progressive thinning and perforations. The phenomenon depends on the graft used. Hence, the aim of the present study was to compare the damaging effects of a synthetic of a xenogeneic graft. Methods: Forty New Zealand rabbits received a bilateral sinus elevation. Both sinuses of twenty rabbits were grafted with a biphasic 60% hydroxyapatite and 40% β-tricalcium phosphate while the other twenty received a deproteinized bovine bone mineral graft. Thinned sites (<40 µm) and perforations on the mucosa in contact with graft particles were evaluated after 2 and 10 weeks (ten animals each period). The width of the pseudostratified epithelium was also measured as control. Results: After 2 weeks of healing, 61 thinned sites were detected in the Synthetic group and 49 in the Xenogeneic group. After 10 weeks, the number of thinned mucosae increased to 79 sites in the Synthetic group (p = 0.222 between periods), and to 114 sites in the Xenogeneic group (p = 0.030 between groups; p = 0.001 between periods). Perforations were few in the 2-week period, two in two sinuses out of 20 in the Synthetic group, and four in two sinuses out of 20 in the Xenogeneic group (p = 0.721). In the 10-week period, the perforations increased to eight in the Synthetic group, distributed in six sinuses out of 20, and to sixteen in the Xenogeneic group, distributed in 11 sinuses out of 20 (p = 0.082). The pseudostratified epithelium presented a reduced width at the thinned sites. Conclusions: The contact with synthetic or xenogeneic grafts will induce thinning and possible perforations of the sinus mucosa. This effect will increase over time, and it is stronger at the xenogeneic than the synthetic graft.

Sinus Mucosa Thinning and Perforations after Sinus Lifting Performed with Different Xenografts: A Histological Analysis in Rabbits

Background: Experimental studies have shown a progressive thinning and perforations of the sinus mucosa associated with sharpened edges and the cutting projections of graft particles used simultaneously for maxillary sinus augmentation. Hence, the aim of the present study was to evaluate the damaging effects of two different bovine grafts on the sinus mucosa after sinus augmentation. Methods: Twenty New Zealand rabbits received a bilateral sinus lifting using, as fillers, two different types of deproteinized bovine bone in granules, one processed at low temperature (low-T group), and the other at high temperature (high-T group). Thinned mucosa sites (<40 µm) and perforations were evaluated in the sinus mucosa that were in contact with graft granules after 2 and 10 weeks, in ten animals per period. Results: After 2 weeks of healing, the number of thinned mucosa sites was 118 in the low-T group, and 149 in the high-T group (p = 0.191). At the 10-week assessment, the thinned sites increased to 237 and 195 sites, respectively. The numbers of sinus mucosa perforations after 2 weeks were eight and three in the low-T and high-T group, respectively. At the 10-week evaluation, the perforations increased to 19 in the low-T group, and to 14 in the high-T group. Conclusions: The contact with bovine xenografts yielded thinning and perforations of the sinus mucosa. Despite the differences in characteristics and dimensions, no differences were found between the two xenografts in the numbers of thinning mucosa sites and perforations. However, a trend of more events was found in the low-T compared to the high-T group.

A Fully Human Monoclonal Antibody Targeting cKIT Is a Potent Inhibitor of Pathological Choroidal Neovascularization in Mice.

Stem cell factor (SCF) and its receptor, cKIT, are novel regulators of pathological neovascularization in the eye, which suggests that inhibition of SCF/cKIT signaling may be a novel pharmacological strategy for treating neovascular age-related macular degeneration (AMD). This study evaluated the therapeutic potential of a newly developed fully human monoclonal antibody targeting cKIT, NN2101, in a murine model of neovascular AMD. In hypoxic human endothelial cells, NN2101 substantially inhibited the SCF-induced increase in angiogenesis and activation of the cKIT signaling pathway. In a murine model of neovascular AMD, intravitreal injection of NN2101 substantially inhibited the SCF/cKIT-mediated choroidal neovascularization (CNV), with efficacy comparable to aflibercept, a vascular endothelial growth factor inhibitor. A combined intravitreal injection of NN2101 and aflibercept resulted in an additive therapeutic effect on CNV. NN2101 neither caused ocular toxicity nor interfered with the early retinal vascular development in mice. Ocular pharmacokinetic analysis in rabbits indicated that NN2101 demonstrated a pharmacokinetic profile suitable for intravitreal injection. These findings provide the first evidence of the potential use of the anti-cKIT blocking antibody, NN2101, as an alternative or additive therapeutic for the treatment of neovascular AMD.

Osseointegration of a novel 3D porous Ti-6Al-4V implant material - Histomorphometric analysis in rabbits.

Porous structure properties are known to conduct initial and long-term stability of titanium alloy implants. This study aims to assess the histomorphometric effect of a 3-D porosity in Ti-6Al-4V implants (PI) on osseointegration in comparison to solid Ti-6Al-4V implants (SI). The PI was produced in a spaceholder method and sintering and has a pore size of mean 400 µm (50 µm to 500 µm) and mimics human trabecular bone. Pairs of PI and equal sized SI as reference were bilaterally implanted at random in the lateral femoral condyle of 16 Chinchilla-Bastard rabbits. The animals were sacrificed after 4 and 12 weeks for histomorphometric analysis. The histomorphometric evaluation confirmed a successful short-term osseohealing (4 weeks) and mid-term osseoremodeling (12 weeks) for both types of implants. The total newly formed bone area was larger for PI than for SI after 4 and 12 weeks, with the intraporous bone area being accountable for the significant difference (p<0.05). A more detailed observation of bone area distribution revealed a bony accumulation in a radius of +/- 500 µm around the implant surface after remodeling. The bone-to-implant contact (BIC) increased significantly (p<0.05) from 4 to 12 weeks (PI 26.23 % to 42.68 %; SI 28.44 % to 47.47 %) for both types of implants. Due to different surface properties, however, PI had a significant (p<0.05) larger absolute osseous contact (mm) to the implant circumference compared to the SI (4 weeks: 7.46 mm vs 5.72 mm; 12 weeks: 11.57 mm vs 9.52 mm [PI vs. SI]). The regional influences (trabecular vs. cortical) on bone formation and the intraporous distribution were also presented. Conclusively, the porous structure and surface properties of PI enable a successful and regular osseointegration and enhance the bony fixation compared to solid implants under experimental conditions.

Can platelet-rich plasma coating improve polypropylene mesh integration? An immunohistochemical analysis in rabbits.

ABSTRACTPurpose:Despite high success rates in the treatment of urinary incontinence, complications related to the use of polypropylene (PP) meshes are still a concern, especially in vaginal prolapses surgeries. The objective of this study was to assess the effect of autologous platelet-rich plasma (PRP) coating on the integration of PP meshes implanted in the vaginal submucosa of rabbits.Materials and Methods:Thirty adult New Zealand rabbits were randomly divided into two groups (n=15): PP, implanted with conventional PP meshes; and PRP, implanted with autologous PRP coated PP meshes. Animals in both groups (n=5) were euthanized at 7, 30 and 90 days postoperatively, the vaginas extracted and sent to immunohistochemical analysis for the assessment of the pro-inflammatory agent TNF-α, anti-inflammatory agents TGF-β and IL-13, collagen metabolism marker MMP-2, and angiogenesis marker CD-31. AxioVision™ image analysis was used for the calculation of the immunoreactive area and density. Statistical analysis was performed with ANOVA followed by Tukey test (p <0.05).Results:Animals in the PRP group showed significantly increased expression of the angiogenesis agent CD-31 at all experimental times when compared to the PP group (p <0.0001). However, no differences concerning the expression of the other markers were observed between the groups.Conclusion:The addition of autologous PRP gel to PP meshes can be simply and safely achieved and seems to have a positive effect on implantation site angiogenesis. Further investigations are required to ascertain PPR coated meshes clinical efficacy in prolapses and stress urinary incontinence surgeries.

Enhancing the Low Oral Bioavailability of Sulpiride via Fast Orally Disintegrating Tablets: Formulation, Optimization and In Vivo Characterization.

Sulpiride (SUL) is a dopamine D2-receptor antagonist used for management of GIT disturbance and it has anti-psychotic activities based on the administered dose. SUL undergoes P-glycoprotein efflux, which lead to poor bioavailability and erratic absorption. Therefore, the objective of this research was an attempt to enhance the oral bioavailability of SUL via formulation of fast disintegrating tablets (SUL-FDTs) with a rapid onset of action. A 32 full-factorial design was performed for optimization of SUL-FDTs using desirability function. The concentration of superdisintegrant (X1) and Prosolv® (X2) were selected as independent formulation variables for the preparation and optimization of SUL-FDTs using direct compression technique. The prepared SUL-FDTs were investigated regarding their mechanical strength, disintegration time, drug release and in vivo pharmacokinetic analysis in rabbits. The optimized formulation has hardness of 4.58 ± 0.52 KP, friability of 0.73 ± 0.158%, disintegration time of 37.5 ± 1.87 s and drug release of 100.51 ± 1.34% after 30 min. In addition, the optimized SUL-FDTs showed a significant (p < 0.01) increase in Cmax and AUC(0–∞) and a relative bioavailability of about 9.3 fold compared to the commercial product. It could be concluded that SUL-FDTs are a promising formulation for enhancing the oral bioavailability of SUL concomitant with a fast action.

HPLC methods of fexofenadine quantitative analysis in rabbits’ liver

The investigation of pharmacokinetics of marker substrates of carrier protein P-glycoprotein (Pgp, ABCB1-protein) including fexofenadine, is one of the methods of its functional activity evaluation.The aim of the study was to work out the HPLC methods of the quantitative determination of fexofenadine in rabbits’ liver.Materials and methods. The quantitative determination of fexofenadine was performed using Stayer chromatographic system (Akvilon, Russia) with UVV 104 ultraviolet detector. Reverse-phased chromatographic column Luna C18 100Å (250*4.6) was used with 5 µm granulation at 45°С. The сoncentration of fexofenadine was determined by methods of absolute peak area calibration.Results. The work was conducted in the isocratic mode. The composition of the mobile phase consisted of deionized water, acetonitrile and glacial acetic acid at the ratio of 267.4:120:4.33 brought to pH=6.7 with triethylamine. The sample processing was in the form of homogenization of 500 mg of ground liver in 500 µl of purified water with the subsequent centrifugation (1750 g) and selection of the supernatant. The proteins were precipitated by acetonitrile (2.5 ml) acidified with 375 µl of hydrochloric acid by shaking at 500 rev/min. The supernatant was transported into a separate test tube, where methylene chloride, diethyl ether and ethyl acetate were added (2 ml each). Then the solution was again shaken for 10 minutes (500 rev/min). After that, the solution was centrifuged (1750 g) and the supernatant was evaporated on a rotor-vacuum evaporator at 50°С. 300 µl of the mobile phase was added to the dry residue, and 100 µl was injected into the chromatograph. The method was validated in the linear range from 3 to 60 µg/g of fexofenadine with the acceptable intra- and intercycle accuracy, precision and stability. The method was tested on rabbits after the intravenous administration of fexofenadine at the dose of 11 mg/kg.Conclusion. The HPLC methods of fexofenadine quantitative determination in the hepatic tissue of rabbits has been worked out. It can be used for the evaluation of the functional activity of Pgp in preclinical studies.Abbreviations: Pgp – P-glycoprotein, HPLC – high performance liquid chromatography, rev/min – revolutions per minute

Acid-base-balance status and blood gas analysis in rabbits with gastric stasis and gastric dilation

ABSTRACT Background: The aim of this study was to analyse the acid-base-balance status and blood gas values in rabbits with gastric stasis and gastric dilation syndrome. Methods: Thirty rabbits with corresponding symptoms and radiographs were sampled before, during, and after treatment and an arterial acid-base-balance status and blood gas analysis was performed. Results: pCO2, HCO3, and base excess were significantly lower in animals that were presented 12 hours after the owner had registered signs of illness than animals presented within 6 hours. Of the examined rabbits, 57% had acidosis, 83% of which were of metabolic origin. The pH returned to normal after treatment in 94% of surviving animals (24/30). Conclusions: Gastric stasis and dilation syndrome has a considerable impact on the acid-base-balance status and blood gas analysis in rabbits and its measurement is therefore valuable for assessing the patient's status and adjusting the therapy accordingly to each animal's needs. Clinical relevance: Our findings underline the importance of a swift introduction of rabbits with gastric stasis and dilation syndrome into veterinary care to prevent further impairment of secondary findings such as metabolic acidosis.

Effect of feeding rabbits on fungal treated corn stalks on carcass characteristics and meat composition

BackgroundCorn stalk as low quality roughage is high in lignocellulytic materials and low in readily available carbohydrates and nitrogen as well as several minerals. Intake and utilization of it can be increase by applying some treatments; physical, chemical, and biological methods, biological method shows the most effective method. This study aimed to evaluate the effect of replacing clover hay (it is high quality roughage in Egypt and high price) by fungal treated corn stalks with Trichoderma ressei on carcass characteristics and meat analysis of rabbits. Forty-two weaned New Zealand white rabbits were divided to two groups. The first group (24 rabbits) was divided into 4 subgroups (6 each), and were fed diets contained 0% corn stalks (control), 33, 66, and 100% treated corn stalks with media only (without Trichoderma ressei). The second group (18 rabbits) was divided into 3 subgroups (6 each), and were fed diets contained 33, 66, and 100% fungal treated corn stalks with Trichoderma ressei as replaced of clover hay (11, 22, and 33% of whole), each group was divided into 3 replicates (2 each). At the end of the trial, 3 rabbits from each group were slaughtered to derermine carcass characteristics and chemical composition of meat.ResultsThere were no significant differences in values of dressing percentages either between treatments or levels. Also, the interaction between treatments and levels were no significant. Feeding fungal treated corn stalks did not significant effect on dry matter (DM), crude protein (CP), and ether extract (EE), while significant(P < 0.05) increased ash content compared with without Trichoderma reesei. And feeding 100% corn stalks recorded (P < 0.05) the highest value compared with levels 33 and 66%. The interaction between treatments and levels on CP, EE, and ash was significant, the results pointed that fed level of 66% treated corn stalks was significant (P < 0.05) increased CP content compared with 66% without Trichoderma reesei. Also fed level of 100% treated corn stalks was recorded (P < 0.05) the highest value of ash content compared with level of 66% treated CS and with levels of 33, 66, and 100% without Trichoderma reesei, respectively. While fed treated corn stalks at 66% significant (P < 0.05) decreased EE content compared with feeding level of 66% without Trichoderma reesei. But, there were no significant difference in DM content. It could be concluded that treated corn stalks with fungi could be used without any adverse effects and enhance carcass characteristics and chemical composition of rabbits meat.

Formulation of Gastro-retentive Floating Tablets of Valsartan by 2 power 2 Factorial Designs: In vitro and In vivo Evaluations

An oral dosage form containing gastro-retentive floating tablets forms a stomach-specific drug delivery system for the treatment of hypertension. Valsartan belongs to the BCS class II (poo Classification System). It is desirable to improve the extent of bioavailability (23%). The objective of the present study was to apply design of experiment to optimize floating drug delivery of valsartan by employing 22 factorial design. Improvement of the aqueous solubility of valsartan was done by solid dispersions using hot melt extrusion technique. Plasdone S630 copovidone is a variable carrier and drug to carrier ratio of 1:2 was optimized. Valsartan floating tablets were prepared by employing factorial design (22), where HPMC K15M (X1) and pregelatinized starch (X2) were independent variables and drug dissolution was the dependent parameter (Y1) to prepare matrix tablets. The factorial analysis, steepest ascent method was utilized for obtaining optimized formulation. In vitro evaluation, In vivo radiographic study and biopharmaceutical analysis in rabbits for valsartan optimized formulation (FT-5). Floating lag time (FLT) for valsartan optimized formulation (FT-5) was 15 s and total floating time (TFT) of the tablets was about 33 h, which was satisfactory. A four-point (1 h, 4 h, 8 h and 16 h) dissolution analysis gave satisfactory dissolution profile up to 24 h. The release kinetics of valsartan optimized formulation (FT-5) followed zero order and the release mechanism was found to be Korsemeyer Peppas model, i.e. swelling type. The dissolution efficiency for valsartan floating tablets was 1190.89% against the marketed formulation of 39.77%. The accelerated stability profile of valsartan optimized formulation (FT-5) was evaluated in terms of drug content and percent cumulative dissolution of valsartan in 24 h, in a 6 months study. In vivo X-ray image study for valsartan optimized formulation (FT-5) indicated the presence of intact tablet up to 12 h in gastric region of rabbit. The biopharmaceutical analysis in rabbits was conducted for valsartan optimized formulation (FT-5). The HPLC method was established and validated for the in vivo analysis. The Cmax was 453.2 ng/mL compared to that of the marketed tablets (522.4 ng/mL). The mean residence time (MRT) for the valsartan optimized formulation (FT-5) was 14.82 h as against 4 h for marketed tablet. The relative bioavailability of valsartan optimized formulation (FT-5) was 650% higher than the marketed tablet. To overcome the poor bioavailability of valsartan, it was suitably modified using hot-melt extrusion for improving therapeutic outcome. In conclusion, gastro-retentive drug delivery system is an excellent approach for improving the bioavailability of valsartan. &#x0D;

High-resolution mapping of fluoroquinolones in TB rabbit lesions reveals specific distribution in immune cell types.

Understanding the distribution patterns of antibiotics at the site of infection is paramount to selecting adequate drug regimens and developing new antibiotics. Tuberculosis (TB) lung lesions are made of various immune cell types, some of which harbor persistent forms of the pathogen, Mycobacterium tuberculosis. By combining high resolution MALDI MSI with histology staining and quantitative image analysis in rabbits with active TB, we have mapped the distribution of a fluoroquinolone at high resolution, and identified the immune-pathological factors driving its heterogeneous penetration within TB lesions, in relation to where bacteria reside. We find that macrophage content, distance from lesion border and extent of necrosis drive the uneven fluoroquinolone penetration. Preferential uptake in macrophages and foamy macrophages, where persistent bacilli reside, compared to other immune cells present in TB granulomas, was recapitulated in vitro using primary human cells. A nonlinear modeling approach was developed to help predict the observed drug behavior in TB lesions. This work constitutes a methodological advance for the co-localization of drugs and infectious agents at high spatial resolution in diseased tissues, which can be applied to other diseases with complex immunopathology.

Evaluation of the effect of self‐cutting and non self‐cutting thread designed implant with different thread depth on variable insertion torques – an histomorphometric analysis in rabbits.

Evaluation of the effect of self‐cutting and non self‐cutting thread designed implant with different thread depth on variable insertion torques – an histomorphometric analysis in rabbits.

Evaluation of the effect of self-cutting and nonself-cutting thread designed implant with different thread depth on variable insertion torques: An histomorphometric analysis in rabbits.

To evaluate of the effect of self-cutting and nonself-cutting thread designed implant with different thread depth on variable insertion torques. To evaluate the bone volume (BV) and bone to implant contact (BIC) in these variables MATERIALS AND METHODS: Mainly two thread design, V-shaped thread which is self-cutting and power thread design, which is nonself-cutting implants were considered for this study with a variation in thread depth of 0.4 and 0.6 mm for both the designs, respectively. A total of 32 CAD designed machined surface implant prototypes were manufactured of 4 mm in diameter and 8 mm in length were made, which were machined surfaced, which was placed in the femur of 16 New Zealand white rabbits. These were categorized under 2 groups; Group 1 and Group 2 with insertion torques of <30 and >50 Ncm, respectively. After 4 weeks of healing, rabbits were sacrificed and histomophometric and histologic analyses were done to evaluate the bone response. Significantly, more BIC was recorded for high torque implants compared with low torque in power-shaped thread design (P value = .01*). BV for new bone formation was statistically significant for V-shaped thread design in high torque when compared with low torque (P value = .02*). The effect of the depth of the thread design was significant for the power-shaped design in enhancing BIC when compared with V-shaped thread design. With high torque V-shaped thread design had more new bone formation as compared with power-shaped thread design.

In vivo evaluation of cp Ti implants with modified surfaces by laser beam with and without hydroxyapatite chemical deposition and without and with thermal treatment: topographic characterization and histomorphometric analysis in rabbits.

We aimed to assess the surfaces of commercially pure titanium implants (cp Ti) with modified surfaces by laser beam (LS) with and without hydroxyapatite (HA) deposition, without (HAB) and with (HABT) thermal treatment. Furthermore, we have compared them with implants with surfaces modified by acid treatment (AS) and with machined surfaces (MS) utilizing histomorphometric and descriptive histologic analyses. Surface topography characterization was analyzed by scanning electron microscopy (SEM), X-ray energy-dispersive spectroscopy (EDX), and surface roughness (Ra) before implant installation. Forty-five rabbits received seventy-five implants in their left and right tibias and were randomly divided into five groups (n=5 implants per group): (1) cp Ti implant modified by LS, (2) cp Ti implant modified by laser beam associated with HA deposition without heat treatment (HAB), (3) cp Ti implant modified by laser beam associated with HA deposition with heat treatment (HABT), (4) cp Ti implant with modified surface by means of acid treatment (Master Porous) commercially available (AS), and (5) cp Ti implant with MS commercially available. After 30, 60, and 90days, the animals were euthanized and the implants and surrounding bone were removed and prepared by a non-decalcified histological process. The percentage of bone-to-implant contact (BIC) and the bone area fraction occupancy (BAFO) between the first three threads was evaluated to the higher cortical region. BIC (%) was statistically superior (p<0.001) on the LS (69.36±7.91, 71.67±8.79, and 79.69±3.3), HAB (73.22±3.75, 69.48±1.89, and 75.7±4.62), and HABT (65.41±5.51, 71.3±2.5, and 79.68±5.01) compared with AS (49.15±5.76, 41.94±2.85, and 57.18±7.81) and MS (36.69±7.24, 52.52±2.75, and 51.31±6.96) in the 30, 60, and 90-day periods, respectively. BAFO (%) of HAB at 30days (90.17±6.24) was statistically superior (p<0.01) to all the other groups. At 60 and 90days, BAFO of LS (87.17±5.9 and 87.99±2.52), HAB (85.95±3.93 and 82.17±3.65), and HABT (83.27±1.44 and 88.67±2.67) was higher than the AS (77.49±5.83 and 76.42±5.98) and MS (74.01±4.68 and 73.81±4.91). Collectively, our data indicate that the modified surfaces LS, HAB, and HABT favored the interaction between bone and implant and increased bone formation. In addition, HAB showed higher biological behavior favoring the osseointegration. Our study provides evidence that LS, HAB, and HABT-modified surfaces improved bone-to-implant contact and increased bone formation around osseointegrated implants compared to conventional machined implants favoring the osseointegration process.

Signal quality of endovascular electroencephalography

Objective, Approach. A growing number of prototypes for diagnosing and treating neurological and psychiatric diseases are predicated on access to high-quality brain signals, which typically requires surgically opening the skull. Where endovascular navigation previously transformed the treatment of cerebral vascular malformations, we now show that it can provide access to brain signals with substantially higher signal quality than scalp recordings. Main results. While endovascular signals were known to be larger in amplitude than scalp signals, our analysis in rabbits borrows a standard technique from communication theory to show endovascular signals also have up to 100× better signal-to-noise ratio. Significance. With a viable minimally-invasive path to high-quality brain signals, patients with brain diseases could one day receive potent electroceuticals through the bloodstream, in the course of a brief outpatient procedure.