Experimental animal study of docetaxel combined with carboplatin in the treatment of retinoblastoma

The synergistic effects of docetaxel (DTX) combined with carboplatin in the treatment of retinoblastoma (RB) was explored in mouse RB xenografts compared with carboplatin alone and DTX alone groups. Retinoblastoma Y-79 cells (4.0×10⁷/ml) were injected into the vitreous body of the right eye of mice to establish the mouse model of RB xenografts. Then the mice were randomly divided into 4 groups (n=30): DTX combined with carboplatin group (group A), carboplatin group (group B), DTX group (group C) and blank control group (group D). The changes in tumors, the survival time of mice, and the synergistic effects of DTX combined with carboplatin were observed and analyzed. The diameters and weight of the right eyeballs of the Institute for Cancer Research (ICR) mice were significantly larger and higher than those of the left eyeballs in each group, respectively (P<0.05). The diameters and weight in group A were significantly shorter and lighter than those in the other three groups, respectively (P<0.05), and there was no significant difference compared with that of normal eyeballs (P>0.05). There was no difference in diameter and weight between group B and group C (P>0.05), but the diameters and weight were shorter and lighter than those in group D, respectively (P<0.05). The survival time of ICR mice in groups A, B and C was significantly longer than that in group D (P<0.05). The survival time in group A was significantly longer than that in groups B and C (P<0.05). There was no significant difference in the survival time between the group B and group C (P>0.05). DTX, carboplatin and the combination of the two have significant inhibitory effects on RB; however, DTX combined with carboplatin has a better therapeutic effect on RB.

Effect of Halofuginone on the Pathogenesis of Autoimmune Thyroid Disease in Different Mice Models

OBJECTIVE

Our objectives were to investigate the therapeutic effect of halofuginone (HF) in the treatment of autoimmune thyroid diseases (AITDs) and explore its underlying mechanism of action.

METHODS

The Graves' disease (GD) model was generated by immunizing female BALB/c mice with adenovirus expressing the TSH receptor A subunit (Ad-TSHR289). The Ad-TSHRA+HF and Ad- TSHRA+DMSO groups were injected intraperitoneally with HF or the vehicle control (DMSO), respectively. The autoimmune thyroiditis (AIT) group consisted of female NOD.H-2h4 mice that were administered NaI in the drinking water and intraperitoneally injected daily with the vehicle control (DMSO) during the study period. The AIT/HF group consisted of female NOD.H-2h4 mice that were administered NaI in the drinking water and intraperitoneally injected daily with HF. The frequencies of splenic Th17 cells, Tregs and Bregs were determined by flow cytometry. The mRNA levels of IL-17, forkhead box P3 (Foxp3), RORγt and IL-10 were determined by real-time PCR.

RESULTS

In both Ad-TSHRA+DMSO and Ad-TSHRA+HF groups, 10 out of 15 mice displayed serum T4 and TSAb levels above 3 SD beyond the mean control levels. The number of CD4+CD25+Foxp3+ T lymphocytes in the GD model was significantly increased in the HF group compared with the DMSO group (P < 0.05). The mRNA level of Foxp3 was significantly increased in the Ad-TSHRA+HF group compared with the Ad-TSHRA+DMSO group (P < 0.05). However, neither the abundance of CD4+IL-17+ T cell subpopulation nor the mRNA expression level of RORγt differed significantly between the Ad-TSHRA+HF and Ad-TSHRA+DMSO groups (P > 0.05). The serum TgAb titer was significantly reduced in the AIT/HF group compared with the AIT group (P < 0.01). The differences in the number of CD4+CD25+Foxp3+ T lymphocytes and the mRNA levels of Foxp3 between the AIT/HF and AITgroups were not significant (P > 0.05). However, the number of CD4+IL-17+ T cells and the mRNA levels of IL-17 and RORγt were significantly increased in HF-treated mice compared with the non-treated AIT-induced mice (P < 0.05).

CONCLUSION

Treatment with HF significantly decreased the incidence of AIT by decreasing the number of CD4+IL-17+ T cells.

Anti-resorptive effect of pamidronate on extraction socket wall in dogs

AIM

The aim of this experimental in vivo investigation was to assess the anti-resorptive effect of low concentration pamidronate on the buccal plate in fresh extraction sockets.

MATERIALS AND METHODS

The distal roots of the third premolars were extracted bilaterally in six dogs. A collagen matrix loaded with either pamidronate (test group) or saline (control group) was positioned on the outer surface of buccal bone immediately after tooth extraction and subsequently covered with a coronally advanced flap. Histological and histomorphometric outcomes were evaluated 12 weeks later.

RESULTS

The mean vertical distance between the buccal and lingual bone crest differed significantly between the test and control groups (0.52 ± 0.43 and 2.21 ± 1.15 mm, respectively; p = .037). The width of the buccal bone 1 mm below the crest was significantly wider in the test group than the control group (4.68 ± 0.68 vs. 3.44 ± 0.60 mm, p < .001).

CONCLUSIONS

Local application of pamidronate onto a collagen matrix may reduce the dimensional changes of the buccal bone plate both vertically and horizontally.

[Effects of maternal exposure to bisphenol A during pregnancy on puberty in advance and hypothalamo-pituitary gonadal axis hormones level in female offspring]

OBJECTIVE

To investigate the effect of maternal exposure to bisphenol A on puberty in advance and hypothalamus-pituitary-gonad axis( HPG axis) hormones level in female offspring.

METHODS

A total of 105 pregnant CD-1 mice aged 8 weeks were daily administered with BPA at four different doses( 0, 8, 40 and 200 mg/kg) by gavage from gestational day( GD) 0 to 18. Offspring were weighed and determined sex by anal reproductive distance after birth. From postnatal day( PND) 21-34, the vaginal opening of female offspring and distinguished the estrous stage through vaginal smears wereobserved. The level of GnRH, FSH, LH and E2 hormone in serum were detected.

RESULTS

The mean initial time of vaginal opening in 8 mg/kg group [( 28. 0 ± 0. 36)days], 40 mg/kg group [( 28. 0 ± 0. 33) days] and 200 mg/kg group [( 28. 0 ± 0. 61)days]was earlier than that in the control group [( 30. 0 ± 0. 27) days]. The vaginal opening in advance rate of BPA exposure group was higher than that of the control group and the first estrus occurrence was earlier than controls( P < 0. 05). The levels of GnRH[8 mg/kg:( 9. 78 ± 1. 07) pg/mL, 40 mg/kg:( 11. 55 ± 1. 38) pg/mL, 200 mg/kg:( 10. 09 ± 1. 51) pg/mL]with increased expressions compared with the controls [( 5. 18± 4. 63) pg/mL]. LH level in low dose group [( 1. 86 ± 0. 79) pg/mL] was significantly lower than that in control group [( 2. 37 ± 1. 56) pg/mL]. The above differences were statistically significant( P < 0. 05).

CONCLUSION

These findings suggested that maternal exposure to BPA result in advancing puberty and increase the GnRH hormone level to affect the function of HPG axis in female offspring.

Experimental infection of dogs with highly pathogenic avian influenza virus (H5N8)

During the highly pathogenic avian influenza (HPAI) H5N8 virus outbreak in Korea, a dog in layer farm contaminated by H5N8 was reported seropositive for HPAI H5N8. To investigate the possibility of adaptation and transmission of HPAI H5N8 to dogs, we experimentally inoculated dogs with H5N8. Viral genes were weakly detected in nasal swabs and seroconversions in inoculated and contact dogs. Although the H5N8 virus did not induced severe clinical signs to dogs, the results suggest that surveillance of farm dogs should continue as a species in which the avian influenza virus may acquire infectivity to mammals through frequent contact with the virus.

Upregulation of calprotectin in mild IgE-mediated ovalbumin hypersensitivity

Calprotectin, also known as S100A8/A9, has been linked to gut inflammation caused by IgE-mediated food hypersensitivities, but the pathophysiologic abnormalities it causes remain to be determined. We created a mild food hypersensitivity model through oral gavage of ovalbumin in Norway brown rats without using immune adjuvant. Changes in the levels of calprotectin and inflammation-associated cytokines were then observed over time. We found that fecal calprotectin as well as jejunal and liver TLR4, TNF-α, NF-κB, IL-1β, and IL-6 were upregulated in hypersensitive rats. Additionally, the influence of calprotectin on CD4⁺ T and dendritic cells was observed by co-culturing CD4⁺ T cells with dendritic cells, which revealed a shift toward increased Th2 T cells in calprotectin-treated cultures. These results suggest that calprotectin, along with other inflammatory factors, promotes the inflammation seen in mild food allergy.

Stem cells: a promising candidate to treat neurological disorders

Neurologic impairments are usually irreversible as a result of limited regeneration in the central nervous system. Therefore, based on the regenerative capacity of stem cells, transplantation therapies of various stem cells have been tested in basic research and preclinical trials, and some have shown great prospects. This manuscript overviews the cellular and molecular characteristics of embryonic stem cells, induced pluripotent stem cells, neural stem cells, retinal stem/progenitor cells, mesenchymal stem/stromal cells, and their derivatives in vivo and in vitro as sources for regenerative therapy. These cells have all been considered as candidates to treat several major neurological disorders and diseases, owing to their self-renewal capacity, multi-directional differentiation, neurotrophic properties, and immune modulation effects. We also review representative basic research and recent clinical trials using stem cells for neurodegenerative diseases, including Parkinson’s disease, Alzheimer’s disease, and age-related macular degeneration, as well as traumatic brain injury and glioblastoma. In spite of a few unsuccessful cases, risks of tumorigenicity, and ethical concerns, most results of animal experiments and clinical trials demonstrate efficacious therapeutic effects of stem cells in the treatment of nervous system disease. In summary, these emerging findings in regenerative medicine are likely to contribute to breakthroughs in the treatment of neurological disorders. Thus, stem cells are a promising candidate for the treatment of nervous system diseases.

Is it necessary to use the entire root as a donor when transferring contralateral C7 nerve to repair median nerve?

If a partial contralateral C₇ nerve is transferred to a recipient injured nerve, results are not satisfactory. However, if an entire contralateral C₇ nerve is used to repair two nerves, both recipient nerves show good recovery. These findings seem contradictory, as the above two methods use the same donor nerve, only the cutting method of the contralateral C₇ nerve is different. To verify whether this can actually result in different repair effects, we divided rats with right total brachial plexus injury into three groups. In the entire root group, the entire contralateral C₇ root was transected and transferred to the median nerve of the affected limb. In the posterior division group, only the posterior division of the contralateral C₇ root was transected and transferred to the median nerve. In the entire root + posterior division group, the entire contralateral C₇ root was transected but only the posterior division was transferred to the median nerve. After neurectomy, the median nerve was repaired on the affected side in the three groups. At 8, 12, and 16 weeks postoperatively, electrophysiological examination showed that maximum amplitude, latency, muscle tetanic contraction force, and muscle fiber cross-sectional area of the flexor digitorum superficialis muscle were significantly better in the entire root and entire root + posterior division groups than in the posterior division group. No significant difference was found between the entire root and entire root + posterior division groups. Counts of myelinated axons in the median nerve were greater in the entire root group than in the entire root + posterior division group, which were greater than the posterior division group. We conclude that for the same recipient nerve, harvesting of the entire contralateral C₇ root achieved significantly better recovery than partial harvesting, even if only part of the entire root was used for transfer. This result indicates that the entire root should be used as a donor when transferring contralateral C₇ nerve.

Real-time Monitoring of Contrast-enhanced Ultrasound for Radio Frequency Ablation

Background

This study compared the realtime monitoring effects of conventional ultrasound and contrast-enhanced ultrasound (CEUS) on evaluating radio frequency ablation (RFA) in a living swine liver model.

Methodology

Liver RFA was performed on 10 young swine. Conventional ultrasound and CEUS were performed immediately. After the animals were sacrificed, ablation lesions were removed to histopathologically examine the range of the lesions. Ablation completeness based on three methods were compared using histopathology as the gold standard.

Results

Forty-three ablation lesions were produced in the animals. The horizontal diameter, vertical diameter and ablation lesion area based on conventional ultrasound were all significantly smaller than those based on the gross sample, but no significant differences existed between the results of the CEUS and the gross sample. Histopathology showed that 30 lesions were incompletely ablated and 13 were completely ablated, while CEUS showed that 28 lesions were incompletely ablated and 15 were completely ablated. Compared with histopathology, CEUS had an accuracy of 81.4%, a sensitivity of 83.3%, and a specificity of 76.9%. No significant difference in ablation completeness judgment between CEUS and histopathology was observed.

Conclusion

CEUS provides a real-time radiological foundation for evaluating RFA lesion ranges and completeness in a living swine liver model.

[Effect of different time windows and interventions on skin pressure ulcers and ischemia-reperfusion injury in rats]

OBJECTIVE

To observe the effect of different time windows and interventions on skin pressure ulcers and ischemia-reperfusion (I/R) injury in rats.

METHODS

Sixty?eight SD rats were randomly divided into blank control group (n=4) and model group (n=64). The rats in the model group were randomly divided into group A (n=32) without intervention and group B (n=32) with post?conditioning. The degree of skin compression, neutrophil infiltration and serum levels of free radicals were observed in the rats after compression for 2, 4, 6, and 8 h (8 rats at each time point).

RESULTS

A significant difference was found in the severity of skin damage among the control group, group A, and group B (P=0.001), and the injury was milder in group B than in group A. Severe skin lesions occurred in 2 rats after skin compression for 6 h, as compared with 6 after compression for 8 h (P=0.043), but in none of the rats after compression for 2 or 4. Seventeen rats in group B and 15 in group A showed grade 1 neutrophil infiltration in the skin lesions, and 8 rats in group B and 10 in group A showed grade II neutrophil infiltration (P=0.002). Neutrophil infiltration was the mildest in rats with a 2?h compression, and exacerbated progressively and significantly as the compression time extended (P=0.027). With the prolongation of the intervention time, the rats in both groups A and B showed decreased SOD and increased MDA and NO levels, and overall the I/R injury was milder in 2? and 4?h compression groups than in 6? and 8?h compression groups. The level of serum SOD was significantly higher and MDA and NO levels were significantly higher in group B than in group A (P<0.05).

CONCLUSION

Ischemic post?conditioning can relieve I/R injury in acute pressure ulcer in rats. The effective time window for intervention is within 6 h of ischemia, and the effect of ischemic post-conditioning is optimal within 2 h. Ischemic post?conditioning can alleviate free radical injury and inflammation caused by I/R injury.

[Effect of different time windows and interventions on skin pressure ulcers and ischemia-reperfusion injury in rats]

OBJECTIVE

To observe the effect of different time windows and interventions on skin pressure ulcers and ischemia-reperfusion (I/R) injury in rats.

METHODS

Sixty?eight SD rats were randomly divided into blank control group (n=4) and model group (n=64). The rats in the model group were randomly divided into group A (n=32) without intervention and group B (n=32) with post?conditioning. The degree of skin compression, neutrophil infiltration and serum levels of free radicals were observed in the rats after compression for 2, 4, 6, and 8 h (8 rats at each time point).

RESULTS

A significant difference was found in the severity of skin damage among the control group, group A, and group B (P=0.001), and the injury was milder in group B than in group A. Severe skin lesions occurred in 2 rats after skin compression for 6 h, as compared with 6 after compression for 8 h (P=0.043), but in none of the rats after compression for 2 or 4. Seventeen rats in group B and 15 in group A showed grade 1 neutrophil infiltration in the skin lesions, and 8 rats in group B and 10 in group A showed grade II neutrophil infiltration (P=0.002). Neutrophil infiltration was the mildest in rats with a 2?h compression, and exacerbated progressively and significantly as the compression time extended (P=0.027). With the prolongation of the intervention time, the rats in both groups A and B showed decreased SOD and increased MDA and NO levels, and overall the I/R injury was milder in 2? and 4?h compression groups than in 6? and 8?h compression groups. The level of serum SOD was significantly higher and MDA and NO levels were significantly higher in group B than in group A (P<0.05).

CONCLUSION

Ischemic post?conditioning can relieve I/R injury in acute pressure ulcer in rats. The effective time window for intervention is within 6 h of ischemia, and the effect of ischemic post-conditioning is optimal within 2 h. Ischemic post?conditioning can alleviate free radical injury and inflammation caused by I/R injury.

Polydopamine deposition with anodic oxidation for better connective tissue attachment to transmucosal implants

BACKGROUND AND OBJECTIVE

Nowadays, most designs for the transmucosal surface of implants are machined-smooth. However, connective tissue adhered to the smooth surface of an implant has poor mechanical resistance, which can render separation of tissue from the implant interface and induce epithelial downgrowth. Modification of the transmucosal surface of implants, which can help form a good seal of connective tissue, is therefore desired. We hypothesized that anodic oxidation (AO) and polydopamine (PD) deposition could be used to enhance the attachment between an implant and peri-implant connective tissue. We tested this hypothesis in the mandibles of Beagle dogs.

MATERIAL AND METHODS

AO and PD were used to modify the transmucosal region of transmucosal implants (implant neck). The surface microstructure, surface roughness and elemental composition were investigated in vitro. L929 mouse fibroblasts were cultured to test the effect of PD on cell adhesion. Six Beagle dogs were used for the in vivo experiment (n = 6 dogs per group). Three months after building the edentulous animal model, four groups of implants (control, AO, PD and AO + PD) were inserted. After 4 months of healing, samples were harvested for histometric analyses.

RESULTS

The surfaces of anodized implant necks were overlaid with densely distributed pores, 2-7 μm in size. On the PD-modified surfaces, N1s, the chemical bond of nitrogen in PD, was detected using X-ray photoelectron spectroscopy. L929 developed pseudopods more quickly on the PD-modified surfaces than on the surfaces of the control group. The in vivo experiment showed a longer connective tissue seal and a more coronally located peri-implant soft-tissue attachment in the AO + PD group than in the control group (P < .05).

CONCLUSION

The modification of AO + PD on the implant neck yielded better attachment between the implant and peri-implant connective tissue.

Anti-adhesive effects of a newly developed two-layered gelatin sheet in dogs

Aim

Adhesion after pelvic surgery causes infertility, ectopic pregnancy, and ileus or abdominal pain. The materials currently available for clinical use are insufficient. The purpose of this study was to develop an anti‐adhesive material that overcomes the limitations of conventional anti‐adhesive agents.

Methods

The adhesion prevention effects of three methods – a two‐layered sheet composed of gelatin film and gelatin sponge, Seprafilm and INTERCEED – were evaluated in 37 dogs. Anti‐adhesive effects were investigated macroscopically and microscopically in a cauterized uterus adhesion model. Cell growth on the materials in vitro using human peritoneal mesothelial cells, fibroblasts and uterine smooth muscle cells were also evaluated.

Results

The two‐layered gelatin sheet had significantly superior anti‐adhesive effects compared to the conventional materials (Seprafilm and INTERCEED). A single‐cell layer of mature mesothelium formed three weeks after surgery in the gelatin group. Peritoneum regeneration in the Seprafilm and INTERCEED groups was delayed and incomplete in the early phase. Little inflammation around the materials occurred and cell growth was significantly proliferated with the gelatin sheet.

Conclusion

The anti‐adhesive effects of a two‐layered gelatin sheet were superior to conventional agents in a cauterized canine uterus model, demonstrating early regeneration of the peritoneum, little inflammation and material endurance. The newly developed two‐layered gelatin sheet is a useful option as an anti‐adhesive agent for deeply injured and hemorrhagic sites.

Preparation and properties of calcium citrate nanosheets for bone graft substitute

A convenient and effective soft chemical method is presented for the synthesis of nano-scaled calcium citrate sheets. The preparation involved the precipitation of nano-calcium citrate by adding ethanol to reach the super saturation state of a solution containing calcium and citrate salts. The obtained nano-calcium citrate formed nanosheets, with the following dimensions: width of about 50∼500 nm and thickness of about 8∼30 nm. The results of the XRD analysis confirmed that the obtained sample is calcium citrate tetrahydrate, and the crystal degree decreased with an increase quantity of ethanol added. Animal experiments showed that the calcium citrate can promote the formation of new bone.

Construction of an in vivo carotid siphon model for testing endovascular devices for neuro-interventions

Objective The aim of this study was to construct an in vivo carotid siphon model for testing neurovascular devices for endovascular interventions. Methods A model of a human carotid siphon was pre-shaped using a glass tube from a human cadaver and used to confine a segment of one side of the common carotid artery (CCA) in canines. This segment of CCA with the glass carotid siphon on was interposed end-to-end onto the contralateral CCA so as to simulate a human carotid artery siphon in vivo. Two weeks later, the siphon model was evaluated using computed tomography angiography and digital subtraction angiography, and the covered stent specially designed for intracranial vasculature was navigated through the siphon model for a longitudinal flexibility test. Results All dogs tolerated the procedures well, and the artificial siphon model in vivo provided realistic conditions for device testing. Two weeks later, the in vivo carotid siphon model remained patent with no thrombosis. Five covered stents were navigated to pass through five siphon models successfully, with vasospasm occurring in two siphons. Conclusion Construction of an in vivo siphon model in dogs with a glass tube is feasible and useful for the test of endovascular devices for treating neurovascular diseases.

Difference of auditory brainstem responses by stimulating to round and oval window in animal experiments

ABSTACT To ensure the safety and efficacy of implantable hearing aids, animal experiments are an essential developmental procedure, in particular, auditory brainstem responses (ABRs) can be used to verify the objective effectiveness of implantable hearing aids. This study measured and compared the ABRs generated when applying the same vibration stimuli to an oval window and round window. The ABRs were measured using a TDT system 3 (TDT, USA), while the vibration stimuli were applied to a round window and oval window in 4 guinea pigs using a piezo-electric transducer with a proper contact tip. A paired t-test was used to determine any differences between the ABR amplitudes when applying the stimulation to an oval window and round window. The paired t-test revealed a significant difference between the ABR amplitudes generated by the round and oval window stimulation (t = 10.079, α < .0001). Therefore, the results confirmed that the biological response to round window stimulation was not the same as that to oval window stimulation.

Early implant-associated osteomyelitis results in a peri-implanted bacterial reservoir

Implant-associated osteomyelitis (IAO) is a common complication in orthopedic surgery. The aim of this study was to elucidate how deep IAO can go into the peri-implanted bone tissue within a week. The study was performed in a porcine model of IAO. A small steel implant and either 10⁴ CFU/kg body weight of Staphylococcus aureus or saline was inserted into the right tibial bone of 12 pigs. The animals were consecutively killed on day 2, 4 and 6 following implantation. Bone tissue around the implant was histologically evaluated. Identification of S. aureus was performed immunohistochemically on tissue section and with scanning electron microscopy and peptide nucleic acid in situ hybridization on implants. The distance of the peri-implanted pathological bone area (PIBA), measured perpendicular to the implant, was significantly larger in infected animals compared to controls (p = 0.0014). The largest differences were seen after 4 and 6 days of inoculation, where PIBA measurements of up to 6 mm were observed. Positive S. aureus bacteria were identified on implants and from 25 μm to 6 mm into PIBA. This is important knowledge for optimizing outcomes of surgical debridement in osteomyelitis.

Refinement of Tissue-Engineering Chamber Implantation in the Rat

PURPOSE

Rodent in vivo models that successfully generate new adipose, muscle, or vascular tissue in a tissue-engineering chamber (TEC) has advanced in the last decade. In this article, technical refinements in these operative foreign body implantations have been described to improve the execution of animal models in a way so that they can reduce wastage of time and resources.

MATERIALS & METHODS

Male Sprague-Dawley rats were studied and randomly divided into two equal sized groups. In each group, a different operative procedure was used for implanting the TEC. Twenty animals were operated with diagonal incisions in the groin region, followed by staples for wound closure after TEC implantation. The remaining 20 animals received longitudinal incisions in the abdominal region followed by wound closure with ongoing intradermal nonresorbable sutures and skin glue. The outcome of both procedures with regard to complications, animal growth, and experimental failure was compared. Statistical analysis was performed using the nonparametric chi-squared (χ²) test.

RESULTS

Significant difference in wound dehiscence was recorded in Group I as compared to Group II (p = 0.0001). Consequently, 55% of the experiments had to be aborted in Group I and the animals were removed from the experiment. On the contrary, in Group II, all the animals could be kept.

CONCLUSION

Median longitudinal incisions and thorough wound closure with ongoing intradermal nonresorbable sutures, followed by application of skin glue, are strongly recommended to prevent surgical site complications, such as wound dehiscence, animal harm, and failure of the individual experiment.

Experimental observation of human bone marrow mesenchymal stem cell transplantation into rabbit intervertebral discs

Allogeneic bone marrow mesenchymal stem cell (BMSC) transplantation has been investigated worldwide. However, few reports have addressed the survival status of human BMSCs in the intervertebral discs (IVDs) in vivo following transplantation. The current study aimed to observe the survival status of human BMSCs in rabbit IVDs. The IVDs of 15 New Zealand white rabbits were divided into three groups: Punctured blank control group (L1-2); punctured physiological saline control group (L2-3); and punctured human BMSCs transfected with green fluorescent protein (GFP) group (L3-4, L4-5 and L5-6). One, 2, 4, 6 and 8 weeks after transplantation the IVDs were removed and a fluorescence microscope was used to observe the density of GFP-positive human BMSCs. The results indicated that in the sections of specimens removed at 1, 2, 4, 6 and 8 weeks post-transplantation, no GFP-positive cells were observed in the control groups, whereas GFP-positive cells were apparent in the nucleus pulposus at all periods in the GFP-labeled human BMSCs group, and the cell density at 6 and 8 weeks was significantly less than that at 1, 2 and 4 weeks post-transplantation (P<0.001). Thus, it was identified that human BMSCs were able to survive in the rabbit IVDs for 8 weeks.

Lymphosome concept: Anatomical study of the lymphatic system

The gross anatomical study of the lymphatic system in humans and animals has been suspended for almost 100 years. This article introduces the author's technique for investigating the lymphatic system using the concept of the lymphosome. In revisiting the anatomical study of the lymphatic system, our updated knowledge can potentially be utilized either to reassure surgeons about their current procedures in the surgical management of cancers and lymphedema or assist them to refine them. J. Surg. Oncol. 2017;115:13-17. © 2016 Wiley Periodicals, Inc.

Current concepts of Harm-Benefit Analysis of Animal Experiments - Report from the AALAS-FELASA Working Group on Harm-Benefit Analysis - Part 1

International regulations and guidelines strongly suggest that the use of animal models in scientific research should be initiated only after the authority responsible for the review of animal studies has concluded a well-thought-out harm-benefit analysis (HBA) and deemed the project to be appropriate. Although the process for conducting HBAs may not be new, the relevant factors and algorithms used in conducting them during the review process are deemed to be poorly defined or lacking by committees in many institutions. This paper presents the current concept of HBAs based on a literature review. References on cost or risk benefit from clinical trials and other industries are also included. Several approaches to HBA have been discovered including algorithms, graphic presentations and generic processes. The aim of this study is to better aid and harmonize understanding of the concepts of 'harm', 'benefit' and 'harm-benefit analysis'.

Biomechanical, micro-computed tomographic and immunohistochemical analysis of early osseous integration at titanium implants placed following lateral ridge augmentation using extracted tooth roots

OBJECTIVES

To assess biomechanical, micro-computed tomographic (micro CT) and immunohistochemical characteristics of early osseous integration at titanium implants placed following lateral ridge augmentation using autogenous extracted tooth roots.

MATERIAL & METHODS

The roots of healthy maxillary premolars (PM) and retromolar cortical autogenous bone (AB) blocks were used for lateral ridge augmentation at chronic-type defects in the lower quadrants of n = 16 foxhounds. At 12 weeks, titanium implants were inserted and left to heal for another 3 weeks. Osteocalcin (OC) antigen reactivity, removal torque values (RT) and the bone volume per tissue volume (micro CT- BV/TV) along the implants were assessed.

RESULTS

Median OC (PM: 6.71 vs. AB: 2.73%), RT (PM: 61.97 vs. AB: 44.8 Ncm) and BV/TV (PM: 0.34 vs. AB: 0.21) values were comparable in both PM and AB groups.

CONCLUSIONS

PM and AB grafted sites equally supported the early stages of osseointegration.

Extracted tooth roots used for lateral alveolar ridge augmentation: a proof-of-concept study

OBJECTIVES

To assess the efficacy of tooth roots used as autografts for lateral ridge augmentation and two-stage early osseointegration of titanium implants.

MATERIAL & METHODS

The maxillary premolars were randomly assigned to either endodontic therapy (PM-E) or were left untreated (PM-C). Retromolar cortical autogenous bone (AB) blocks served as controls. PM-E/PM-C and AB were used for ridge augmentation at chronic-type defects in both lower quadrants (n = 8 foxhounds). At 12 weeks, titanium implants were inserted and left to heal for another 3 weeks. Histological analyses considered crestal ridge width (CW); augmented area (AA) and bone-to-implant contact (BIC).

RESULTS

Both PM and AB grafts (exposures: AB = 3; PM-C = 4; PM-E = 7) were gradually involved in the bone remodelling process and associated with a replacement resorption. Median CW (PM-C: 2.70 versus AB: 3.30 mm; PM-E: 2.96 versus AB: 3.35 mm), AA (PM-C: 7.55 versus AB: 8.56 mm(2) ; PM-E: 11.20 versus AB: 6.60 mm(2) ) and BIC (PM-C: 36.96 mm versus AB: 64.10%; PM-E: 50.79 versus AB: 32.53%) values were comparable in both PM and AB groups (p > 0.05, respectively).

CONCLUSIONS

Extracted tooth roots revealed a structural and biological potential to serve as an alternative autograft to autogenous bone. A higher exposure rate may be expected when using endodontically treated teeth.

Signal Increase on Unenhanced T1-Weighted Images in the Rat Brain After Repeated, Extended Doses of Gadolinium-Based Contrast Agents: Comparison of Linear and Macrocyclic Agents

OBJECTIVES

In this prospective preclinical study, we evaluated T1-weighted signal intensity in the deep cerebellar nuclei (CN) and globus pallidus (GP) up to 24 days after repeated administration of linear and macrocyclic gadolinium-based contrast agents (GBCAs) using homologous imaging and evaluation methods as in the recently published retrospective clinical studies. In a second part of the study, cerebrospinal fluid (CSF) spaces were evaluated for contrast enhancement by fluid-attenuated magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Sixty adult male Wistar-Han rats were randomly divided into a control and 5 GBCA groups (n = 10 per group). The administered GBCAs were gadodiamide, gadopentetate dimeglumine, and gadobenate dimeglumine (linear GBCAs) as well as gadobutrol and gadoterate meglumine (macrocyclic GBCAs) and saline (control). Over a period of 2 weeks, the animals received 10 intravenous injections at a dose of 2.5 mmol Gd/kg body weight, each on 5 consecutive days per week. Before GBCA administration, as well as 3 and 24 days after the last injection, a whole-brain MRI was performed using a standard T1-weighted 3-dimensional turbo spin echo sequence on a clinical 1.5 T scanner. The ratios of signal intensities in deep CN to pons (CN/Po) and GP to thalamus (GP/Th) were determined. For the evaluation of the CSF spaces, 18 additional rats were randomly divided into 6 groups (n = 3 per group) that received the same GBCAs as in the first part of the study. After MR cisternography for anatomical reference, a fluid-attenuated inversion recovery sequence was performed before and 1 minute after intravenous injection of a dose of 1 mmol Gd/kg body weight GBCA or saline.

RESULTS

A significantly increased signal intensity ratio of CN/Po was observed 3 and 24 days after the last injection of gadodiamide and gadobenate dimeglumine. No significant changes were observed between the 2 time points. Gadopentetate dimeglumine injection led to a moderately elevated but statistically not significant CN/Po signal intensity ratio. No increased CN/Po signal intensity ratios were determined in the MRI scans of rats that received macrocyclic GBCAs gadobutrol and gadoterate meglumine or saline. The ratio of signal intensity in GP/Th was not elevated in any group injected with GBCAs or saline. Enhanced signal intensities of CSF spaces were observed in the postcontrast fluid-attenuated inversion recovery images of all animals receiving GBCAs but not for saline.

CONCLUSIONS

In this animal study in rats, increased signal intensity in the CN was found up to 24 days after multiple, extended doses of linear GBCAs. However, in contrast to clinical reports, the signal enhancement in the GP was not reproduced, demonstrating the limitations of this animal experiment. The elevated signal intensities remained persistent over the entire observation period. In contrast, no changes of signal intensities in either the CN or the GP were observed for macrocyclic GBCAs. However, all GBCAs investigated were able to pass the blood-CSF barrier in rats to a certain, not yet quantified extent.

Bone formation in mono cortical mandibular critical size defects after augmentation with two synthetic nanostructured and one xenogenous hydroxyapatite bone substitute - in vivo animal study

OBJECTIVES

Healing characteristics as well as level of tissue integration and degradation of two different nanostructured hydroxyapatite bone substitute materials (BSM) in comparison with a deproteinized hydroxyapatite bovine BSM were evaluated in an in vivo animal experiment.

MATERIAL AND METHODS

In the posterior mandible of 18 minipigs, bilateral mono cortical critical size bone defects were created. Randomized augmentation procedures with NanoBone(®) (NHA1), Ostim(®) (NHA2) or Bio-Oss(®) (DBBM) were conducted (each material n = 12). Samples were analyzed after five (each material n = 6) and 8 months (each material n = 6). Defect healing, formation of soft tissue and bone as well as the amount of remaining respective BSM were quantified both macro- and microscopically.

RESULTS

For NHA2, the residual bone defect after 5 weeks was significantly less compared to NHA1 or DBBM. There was no difference in residual BSM between NHA1 and DBBM, but the amount in NHA2 was significantly lower. NHA2 also showed the least amount of soft tissue and the highest amount of new bone after 5 weeks. Eight months after implantation, no significant differences in the amount of residual bone defects, in soft tissue or in bone formation were detected between the groups. Again, NHA2 showed significant less residual material than NHA1 and DBBM.

DISCUSSION

We observed non-significant differences in the biological hard tissue response of NHA1 and DBBM. The water-soluble NHA2 initially induced an increased amount of new bone but was highly compressed which may have a negative effect in less stable augmentations of the jaw.