An immediate peri-implantitis induction model to study regenerative peri-implantitis treatments

OBJECTIVES

The aim of this study was to evaluate the validity of the immediate peri-implantitis model to test regenerative therapies in peri-implantitis defects.

MATERIAL AND METHODS

In an immediate peri-implantitis model in beagles, the mandibular third premolars were extracted, and dental implants were immediately placed in the distal extraction sockets. Without a healing period, experimental peri-implantitis was induced by ligature placement for 3 months. In the conventional peri-implantitis model, dental implants were placed in the healed mandibular fourth premolar region and were submerged for osseointegration. After 3 months of healing, peri-implantitis induction was performed for another 3 months. After peri-implantitis defects were formed in both models, regenerative therapy was performed in both models.

RESULTS

After 3 months in the immediate model and 9 months in the conventional model, similarly shaped horizontal bone defects (wide and craterlike) were observed. However, buccal bone defects were deeply formed in the immediate model compared with the conventional model (6.02 ± 1.20 and 4.34 ± 0.86 mm, respectively; P = 0.009), but the amounts of bone regeneration were not significantly different between the models (P = 0.107). On the lingual side, re-osseointegration was significantly greater in the conventional model than in the immediate model (0.72 ± 0.50 and 1.77 ± 0.87 mm, respectively; P = 0.009), although lingual bone defects were not significantly different between the models (P = 0.248).

CONCLUSIONS

Although the immediate peri-implantitis model is challenging for regeneration, it may be able to replace the conventional model to study regenerative peri-implantitis treatment due to its short experimental time and similar defect configuration.

Targeting the peritoneum with novel drug delivery systems in peritoneal carcinomatosis: a review of the literature

The Peritoneal cavity is a well-known metastatic site for several intra-abdominal malignancies, such as stomach, colon, pancreas and rectal cancer. For long, it was thought that treatment with curative intent was impossible but that was challenged by the introduction of cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC). Although their effectiveness has been proven both experimentally and clinically, there is need for improvement. Firstly, a significant proportion of patients develop recurrent disease. Secondly, HIPEC demands presence of dedicated perfusion devices not readily available in most hospitals. Since intraperitoneal administration of chemotherapy is thought to play a crucial role, new modalities to deliver effective chemotherapeutics to the peritoneum are developed. The current review aims to present an overview of the experimental data on new drug delivery systems (DDS) in peritoneal cancer.

The serum glucan level and pathological changes of antifungal treatment for lower respiratory tract infection of Candida albicans

Due to the fact that Candida albicans colonizes in the upper respiratory tracts of healthy people, whether or not its isolation from airway secretions is sufficient to warrant treatment remains controversial. The animal models of immunosuppressive rats with pulmonary candidiasis were established by the intratracheal inoculating suspensions of C. albicans, and the animals were divided into the following three groups: (1) antifungal treatment group, (2) saline control group, and (3) blank control group. We noted the following in our studies: (1) The fungal load of the saline control group gradually increased such that it was higher than those of the antifungal treated group and was significant from the fourth day of treatment (P < 0.01). (2) The serum (1,3)-β-D-glucan (BG) in the saline control group also gradually increased so that it was significantly higher than found with the treated group by the sixth day of treatment (P < 0.05), and in fact, the rank of pulmonary colony count and BG in the two groups at different time points showed an almost perfect linear correlation. (3) The median survival period of the rats in the antifungal treated group and saline control group was 15 and 8 days respectively, no rats died in the blank control group. (4) The lung lesions from the saline control group gradually became more aggravated than those in the antifungal treated group; no significant pathological changes were found in the blank control group. Antifungal treatment (micafungin) is capable of efficaciously decreasing the lung fungal burden, and continuous monitoring of BG is useful for the evaluation of therapeutic effect of antifungals. Infection of C. albicans with associated pathological damage implies the need for antifungal therapy.

Hints for cyclical recruitment of atelectasis during ongoing mechanical ventilation in lavage and oleic acid lung injury detected by SpO₂ oscillations and electrical impedance tomography

PURPOSE OF THE STUDY

Detection of cyclical recruitment of atelectasis after induction of lavage (LAV) or oleic acid injury (OAI) in mechanically ventilated pigs. Primary hypothesis is that oxygen oscillations within the respiratory cycle can be detected by SpO₂ recordings (direct hint). SpO₂ oscillations reflect shunt oscillations that can only be explained by cyclical recruitment of atelectasis. Secondary hypothesis is that electrical impedance tomography (EIT) depicts specific regional changes of lung aeration and of pulmonary mechanical properties (indirect hint).

MATERIALS AND METHODS

Three groups (each n = 7) of mechanically ventilated pigs were investigated applying above mentioned methods before and repeatedly after induction of lung injury: (1) sham treated animals (SHAM), (2) LAV, and (3) OAI.

RESULTS

Early oxygen oscillations occurred in the LAV group (mean calculated amplitude: 73.8 mmHg reflecting shunt oscillation of 11.2% in mean). In the OAI group oxygen oscillations occurred hours after induction of lung injury (mean calculated amplitude: 57.1 mmHg reflecting shunt oscillations of 8.4% in mean). The SHAM group had no relevant oxygen oscillations (<30 mmHg, shunt oscillations < 1.5%). Synchronously to oxygen oscillations, EIT depicted (1) a decrease of ventilation in dorsal areas, (2) an increase in ventral areas, (3) a decrease of especially dependent expiratory impedance, 3) an increase in late inspiratory flow especially in the dependant areas, (4) an increase in the speed of peak expiratory flow (PEF), and (5) a decrease of dorsal late expiratory flow.

CONCLUSIONS

SpO2 and EIT recordings detect events that are interpreted as cyclical recruitment of atelectasis.

Rapidly constructed scaffold-free embryonic stem cell sheets for ocular surface reconstruction

This study is an extension of our previously published work demonstrating the generation of corneal epithelial sheets using optimal centrifugation procedure. In this study, we investigated the therapeutic potential of embryonic stem cells (ESCs) for ocular surface reconstruction in rabbits with limbal stem cell deficiency (LSCD) using the centrifugation method. Rabbits with LSCD were assigned to two groups: 30 LSCD rabbits were treated with scaffold-free embryonic stem cells sheets (SESCS) and six LSCD rabbits received no treatment (control group). The two groups were followed up for 15 days using slit lamp observation. Cytokeratin K3, mucin 5AC, and OCT-4 were used to evaluate the re-epithelialization of the cornea. Fluorescent DiIC18(3)-DS dye was used to trace the transplanted cells. Atomic force microscopy (AFM) was used to investigate the cultured epithelial cells of the SESCS-treated group. The SESCS transplant facilitated the reconstruction of the ocular surface in 75% of the treated animals. Conjunctivalization and neovascularization were observed in the control group. The SESCS group was K3 positive and MUC5AC negative, and OCT-4 was observed on the re-epithelialized corneal epithelium. Labeled SESCS cells were detected in vivo at 15 days post-transplant. Using AFM, three different types of cultured cells were identified in the rabbit corneal epithelium of the SESCS treatment group. The SESCS were demonstrated to reconstruct the ocular surface in rabbits with LSCD. ES cells differentiated into corneal epithelial cells when in direct contact with the stroma and thus can serve as a cell source in corneal tissue engineering.

In vivo monitoring of implant osseointegration in a rabbit model using acoustic sound analysis

Implant osseointegration can currently only be assessed reliably post mortem. A novel method that relies on the principle of acoustic sound analysis was developed to enable examination of the longitudinal progress of osseointegration. The method is based on a magnetic sphere inside a hollow cylinder of the implant. By excitation using an external magnetic field, collision of the sphere inside the implant produces a sound signal. Custom-made titanium implants equipped thusly were inserted in each lateral femoral epicondyle of 20 New Zealand White Rabbits. Two groups were investigated: Uncoated, machined surface versus antiadhesive surface; and calcium phosphate-coated surface versus antiadhesive surface. The sound analysis was performed postoperatively and weekly. After 4 weeks, the animals were euthanized, and the axial pull-out strengths of the implants were determined. A significant increase in the central frequency was observed for the loose implants (mean pull-out strength 21.1 ± 16.9 N), up to 6.4 kHz over 4 weeks. In comparison, the central frequency of the osseointegrated implants (105.2 ± 25.3 N) dropped to its initial value. The presented method shows potential for monitoring the osseointegration of different implant surfaces and could considerably reduce the number of animals needed for experiments.

Survival of rabid rabbits after intrathecal immunization

Rabies is a fatal zoonotic disease for which no effective treatment measures are currently available. Rabies virus (RABV) has anti-apoptotic and anti-inflammatory properties that suppress nerve cell damage and inflammation in the CNS. These features imply that the elimination of RABV from the CNS by appropriate treatment could lead to complete recovery from rabies. Ten rabbits showing neuromuscular symptoms of rabies after subcutaneous (SC) immunization using commercially available vaccine containing inactivated whole RABV particles and subsequent fixed RABV (CVS strain) inoculation into hind limb muscles were allocated into three groups. Three rabbits received no further treatment (the SC group), three rabbits received three additional SC immunizations using the same vaccine, and four rabbits received three intrathecal (IT) immunizations, in which the vaccine was inoculated directly into the cerebrospinal fluid (the SC/IT group). An additional three naïve rabbits were inoculated intramuscularly with RABV and not vaccinated. The rabbits exhibited neuromuscular symptoms of rabies within 4-8 days post-inoculation (dpi) of RABV. All of the rabbits died within 8-12 dpi with the exception of one rabbit in the SC group and all four rabbits in SC/IT group, which recovered and started to respond to external stimuli at 11-18 dpi and survived until the end of the experimental period. RABV was eliminated from the CNS of the surviving rabbits. We report here a possible, although still incomplete, therapy for rabies using IT immunization. Our protocol may rescue the life of rabid patients and prompt the future development of novel therapies against rabies.

Quantification of viral infection dynamics in animal experiments

Analyzing the time-course of several viral infections using mathematical models based on experimental data can provide important quantitative insights regarding infection dynamics. Over the past decade, the importance and significance of mathematical modeling has been gaining recognition among virologists. In the near future, many animal models of human-specific infections and experimental data from high-throughput techniques will become available. This will provide us with the opportunity to develop new quantitative approaches, combining experimental and mathematical analyses. In this paper, we review the various quantitative analyses of viral infections and discuss their possible applications.

Alteration of masticatory function by diet change induces stress responses in Wistar rats

The occlusion-mastication system has extradigestive functions; however, whether liquid feeding evokes stress responses remains unclear. In this study, reactions to low masticatory performance were analyzed using a diet-alteration model in Wistar rats. Seven days after the diet of the rats was changed from solid to liquid, serum epinephrine and norepinephrine concentrations were found to be elevated by 205% and 158% compared to baseline values, respectively. Superoxide production by peritoneal neutrophils was higher in rats fed with a liquid diet than in those fed with a solid diet. Serum superoxide dismutase activity (i.e. the potential to eradicate serum superoxide) was lower in rats fed with liquid than in those fed with a solid diet, indicating that the former experienced oxidative stress. Conversely, the oxidative stress was removed following reversion of the liquid diet to solid diet. These results suggest that liquid diet mastication can cause mental stress, including an oxidative stress response.

Technique for the safe placement of a biodegradable stent into the common bile duct of rabbits

Biodegradable common bile duct (CBD) stents are in high clinical demand. Animal experiments concerning the surgical placement of biliary stents made of new materials are being performed more frequently than ever before. However, these animal experiments only use large animals. In this study, a central venous catheterization set was used as a modified stent introducer system in rabbits. A biodegradable Mg-6Zn alloy CBD stent was passed through the duodenal papilla using this stent introducer system. Computed tomography (CT) scanning of the CBD stent in vivo and levels of serum lipase (LPS) were investigated. Twelve rabbits underwent CBD stent insertion and one animal died due to an anesthetic accident. After 3 weeks, when the remaining 11 rabbits were sacrificed, no jaundice or bile leakage was observed. CT scanning of the 11 rabbits suggested that the biodegradable Mg-6Zn stent was successfully placed into the CBD. When the preoperative and postoperative levels of LPS were compared, no statistically significant differences were observed. This new method appears to be feasible and safe for the placement of stents into the CBDs of small animals. This new method can increase the animal number of CBD stent experiment, and improve the quality of experiments.

Adoptive infusion of tolerance dendritic cells prolongs survival of small intestine allografts in rats: systematic review and meta-analysis

BACKGROUND

Postoperative infections and rejection are the main limiting factors of small intestine allograft survival. In this study, we performed a systematic review and meta-analysis to review rat small intestine allograft survival following infusion of tolerance dendritic cells (Tol-DCs) induced by different methods.

METHODS

Relevant publications were searched from PubMed database and EMbase database. Meta-analysis was performed using RevMan 5.0 software. We chose allograft survival, mixed leukocyte reaction, Th1/Th2 differentiation, Treg induction, and cytotoxic T lymphocyte activity as the outcomes by which to examine possible mechanisms that promote survival.

RESULTS

Eleven suitable articles were identified and assessed. Tol-DCs induced by four methods all prolonged allograft survival. The difference in survival time between the Tol-DC group and the control group was indicated by SMD as follows: drug intervention (SMD = 3.02, 95% CI 1.16 to 4.88, P = 0.001), gene modification (SMD = 2.43, 95% CI 1.77 to 3.10, P < 0.00001), imDC (SMD = 1.76, 95% CI 0.90 to 2.62, P < 0.0001), cytokine induction (SMD = 1.68, 95% CI 0.40 to 2.96, P = 0.01). Tol-DCs were also synergistic with immunosuppressive drugs or costimulation inhibitors, but no immune tolerance was observed. A single-dose intravenous injection of 5×10(6) to 6×10(6) Tol-DCs showed the highest allograft survival. Possible mechanisms included donor-specific T-cell hyporesponsiveness and Th2 differentiation.

CONCLUSIONS

Our results demonstrated that Tol-DCs induced by four methods prolong rat small intestine allograft survival. Intravenous infusion of 5×10(6) to 6×10(6) Tol-DCs was the optimum dose in rat small intestine transplantation. Immunosuppressive or costimulatory blockade was synergistic with Tol-DC on graft survival. Additional high-quality studies with larger sample sizes are needed to better investigate small intestinal graft longer term survival.

Numerical simulation of fluid field and in vitro three-dimensional fabrication of tissue-engineered bones in a rotating bioreactor and in vivo implantation for repairing segmental bone defects

In this paper, two-dimensional flow field simulation was conducted to determine shear stresses and velocity profiles for bone tissue engineering in a rotating wall vessel bioreactor (RWVB). In addition, in vitro three-dimensional fabrication of tissue-engineered bones was carried out in optimized bioreactor conditions, and in vivo implantation using fabricated bones was performed for segmental bone defects of Zelanian rabbits. The distribution of dynamic pressure, total pressure, shear stress, and velocity within the culture chamber was calculated for different scaffold locations. According to the simulation results, the dynamic pressure, velocity, and shear stress around the surface of cell-scaffold construction periodically changed at different locations of the RWVB, which could result in periodical stress stimulation for fabricated tissue constructs. However, overall shear stresses were relatively low, and the fluid velocities were uniform in the bioreactor. Our in vitro experiments showed that the number of cells cultured in the RWVB was five times higher than those cultured in a T-flask. The tissue-engineered bones grew very well in the RWVB. This study demonstrates that stress stimulation in an RWVB can be beneficial for cell/bio-derived bone constructs fabricated in an RWVB, with an application for repairing segmental bone defects.

An empirical study of modified frontolateral partial laryngectomy without tracheotomy

The aim of this study was to validate the feasibility of modified frontolateral partial laryngectomy without tracheotomy using animal experiments. The glottic area before and after surgery of 6 excised canine larynges and 10 canine larynges in vivo were compared to observe whether the glottic area following modified frontolateral partial laryngectomy without tracheotomy is adequate for breathing. Significant differences were observed between the glottic areas of the excised larynges in the initial state and following modified frontolateral partial laryngectomy with the cartilage closed. However, no significant differences were observed between the glottic areas of the excised larynx in the initial state and following modified frontolateral partial laryngectomy with the cartilage open. The glottic area of the larynges in vivo in the initial state and following right chordectomy via laryngofissure were not observed to be significantly different. Furthermore, no significant differences were observed between the glottic areas of the larynges in vivo in the initial state and following modified frontolateral partial laryngectomy without tracheotomy. In conclusion, modified frontolateral partial laryngectomy without tracheotomy is a feasible and efficacious means of eradicating early and selected invasive carcinomas of the larynx, which is supported by animal experiments.

Peri-implant bone formation of non-thermal atmospheric pressure plasma-treated zirconia implants with different surface roughness in rabbit tibiae

OBJECTIVES

The aim of this study was to evaluate and compare the osseointegration of powder-injection molded (PIM) zirconia implants in rabbit tibiae with or without He plasma treatment.

MATERIAL AND METHODS

Twenty-five rabbits received 4 types of external hex implants with identical geometry in the tibiae: PIM zirconia implants, roughened PIM zirconia implants, plasma-treated PIM zirconia implants, and plasma-treated roughened PIM zirconia implants. The contact angles of the four types of implants were evaluated. Removal torque tests and histomorphometric analyses were performed.

RESULTS

The plasma treatment markedly enhanced the hydrophilicity, but did not seem to change the surface topography of the PIM zirconia implants. There were statistically significant differences in the bone-to-implant contact (BIC) ratios, bone volume (BV/TV), and removal torque values (RTQ) among the tested implant types (P < 0.001). The plasma-treated implants exhibited significantly higher BIC and BV/TV values than the untreated implants. However, the removal torque values favored the rough surface.

CONCLUSIONS

The He plasma treatments on PIM zirconia implants made the surface more hydrophilic and enhanced the osseointegration of the implants without changing the micro-topography.

Continuous monitoring of glucose in subcutaneous tissue using microfabricated differential affinity sensors

OBJECTIVE

We describe miniaturized differential glucose sensors based on affinity binding between glucose and a synthetic polymer. The sensors possess excellent resistance to environmental disturbances and can potentially allow wireless measurements of glucose concentrations within interstitial fluid in subcutaneous tissue for long-term, stable continuous glucose monitoring (CGM).

METHODS

The sensors are constructed using microelectromechanical systems (MEMS) technology and exploit poly(N-hydroxy-ethyl acrylamide-ran-3-acrylamidophenylboronic acid) (PHEAA-ran-PAAPBA), a glucose-binding polymer with excellent specificity, reversibility, and stability. Two sensing approaches have been investigated, which respectively, use a pair of magnetically actuated diaphragms and perforated electrodes to differentially measure the glucose-binding-induced changes in the viscosity and permittivity of the PHEAA-ran-PAAPBA solution with respect to a reference, glucose-unresponsive polymer solution.

RESULTS

In vivo characterization of the MEMS affinity sensors were performed by controlling blood glucose concentrations of laboratory mice by exogenous glucose and insulin administration. The sensors experienced an 8-30 min initialization period after implantation and then closely tracked commercial capillary glucose meter readings with time lags ranging from 0-15 min during rapid glucose concentration changes. Clarke error grid plots obtained from sensor calibration suggest that, for the viscometric and dielectric sensors, respectively, approximately 95% (in the hyperglycemic range) and 84% (ranging from hypoglycemic to hyperglycemic glucose concentrations) of measurement points were clinically accurate, while 5% and 16% of the points were clinically acceptable.

CONCLUSIONS

The miniaturized MEMS sensors explore differential measurements of affinity glucose recognition. In vivo testing demonstrated excellent accuracy and stability, suggesting that the devices hold the potential to enable long-term and reliable CGM in clinical applications.

Comparison of Celsior and Perfadex lung preservation solutions in rat lungs subjected to 6 and 12 hours of ischemia using an ex-vivo lung perfusion system

OBJECTIVE

This study evaluated the performance of lungs that were preserved with different solutions (Celsior, Perfadex or saline) in an ex vivo rat lung perfusion system.

METHODS

Sixty Wistar rats were anesthetized, anticoagulated and randomized into three groups (n = 20). The rats were subjected to antegrade perfusion via the pulmonary artery with Perfadex, Celsior, or saline, followed by 6 or 12 hours of ischemia (4ºC, n = 10 in each group). Respiratory mechanics, gas exchange and hemodynamics were measured at 10-minute intervals during the reperfusion of heart-lung blocks in an ex vivo system (IL2-Isolated Perfused Rat or Guinea Pig Lung System, Harvard Apparatus, Holliston, Massachusetts, USA; Hugo Sachs Elektronik, Germany) for 60 minutes. The lungs were prepared for histopathology and evaluated for edema following reperfusion. Group comparisons were performed using ANOVA and the Kruskal-Wallis test with a 5% level of significance.

RESULTS

Gas exchange was not significantly different between lungs perfused with either Perfadex or Celsior at the same ischemic times, but it was very low in lungs that were preserved with saline. Airway resistance was greater in the lungs that were preserved for 12 hours. Celsior lungs that were preserved for 6 and 12 hours exhibited lower airway resistance (p = 0.01) compared to Perfadex lungs. Pulmonary artery pressure was not different between the groups, and no significant differences in histopathology and apoptosis were observed between the groups.

CONCLUSIONS

Lungs that were preserved with Celsior or Perfadex exhibited similar gas exchange and histopathological findings. Airway resistance was slightly lower in the Celsior-preserved lungs compared with the Perfadex-preserved lungs.

Influence of a collagen membrane and recombinant platelet-derived growth factor on vertical bone augmentation in implant-fixed deproteinized bovine bone--animal pilot study

OBJECTIVES

Combinations of bone substitute block materials with membrane techniques as well as with growth factors are possible options to enhance the prognosis of vertical bone augmentation. Therefore, the aim of the pilot study was to compare the influence of a collagen membrane and a signal protein (rhPDGF-BB) on vertical bone augmentation with a stable fixed block material (deproteinized bovine bone [DBB]).

MATERIALS AND METHODS

In 12 rabbits, a DBB-block was implant-fixed on the tibia in a split-leg-design. Included were: DBB only (control), DBB + collagen membrane (test), DBB + rhPDGF-BB (test) and DBB + rhPDGF-BB + collagen membrane (test). 24 samples were examined after 3 (n = 12) and 6 weeks (n = 12). Calculated parameters were new bone area (NBA;%), new vertical bone height (VBH; mm). Due to the pilot character of this study, single values are shown descriptively only.

RESULTS

After 3 weeks, there were constant higher NBA values in the rhPDGF-BB-group without membrane (NBA (%) DBB: 30/16/4; DBB + membrane: 25/17/7, DBB + rhPDGF-BB: 40/33/34, DBB + rhPDGF-BB + membrane: 0/30/16; VBH (mm) DBB: 1.2/1.2/1, DBB + membrane: 0.7/0.9/1, DBB + rhPDGF-BB: 0.7/0.9/1, DBB + rhPDGF-BB + membrane: 0/1.1/1). After 6 weeks, both membrane groups showed a constant higher NBA and VBH independent to the use of rhPDGF-BB (NBA DBB: 3/0/5, DBB + membrane: 20/35/31, DBB + rhPDGF-BB: 5/8/4, DBB + rhPDGF-BB + membrane: 31/35/40; VBH DBB: 0.3/0.3/0.6, DBB + membrane: 1.6/2.4/2.1, DBB + rhPDGF-BB: 0.4/0.7/0.8, DBB + rhPDGF-BB + membrane: 1.8/2/1.8).

CONCLUSIONS

For vertical augmentation, the addition of rhPDGF-BB to DBB-blocks may increase early bone growth. In the later phase, the use of a collagen membrane enhances new bone volume and height to a significant greater extend. Even if the results are higher than those in the non-membrane groups, the low gain of bone after the short time periods still needs improvement.

Bias During the Evaluation of Animal Studies?

My recent book entitled The Costs and Benefits of Animal Experiments seeks to answer a key question within animal ethics, namely: is animal experimentation ethically justifiable? Or, more precisely, is it justifiable within the utilitarian cost:benefit framework that fundamentally underpins most regulations governing animal experimentation? To answer this question I reviewed more than 500 scientific publications describing animal studies, animal welfare impacts, and alternative research, toxicity testing and educational methodologies. To minimise bias I focused primarily on large-scale systematic reviews that had examined the human clinical and toxicological utility of animal studies. Despite this, Dr. Susanne Prankel recently reviewed my book in this journal, essentially accusing me of bias. However, she failed to provide any substantive evidence to refute my conclusions, let alone evidence of similar weight to that on which they are based. Those conclusions are, in fact, firmly based on utilitarian ethical reasoning, informed by scientific evidence of considerable strength, and I believe they are robust.

Effect of garlic on cardiovascular disorders: a review

Garlic and its preparations have been widely recognized as agents for prevention and treatment of cardiovascular and other metabolic diseases, atherosclerosis, hyperlipidemia, thrombosis, hypertension and diabetes. Effectiveness of garlic in cardiovascular diseases was more encouraging in experimental studies, which prompted several clinical trials. Though many clinical trials showed a positive effect of garlic on almost all cardiovascular conditions mentioned above, however a number of negative studies have recently cast doubt on the efficacy of garlic specially its cholesterol lowering effect of garlic. It is a great challenge for scientists all over the world to make a proper use of garlic and enjoy its maximum beneficial effect as it is the cheapest way to prevent cardiovascular disease. This review has attempted to make a bridge the gap between experimental and clinical study and to discuss the possible mechanisms of such therapeutic actions of garlic.

Saline-enhanced radiofrequency thermal ablation of the lung: a feasibility study in rabbits

OBJECTIVE

To assess the feasibility and safety of CT-guided percutaneous transthoracic radiofrequency ablation (RFA) with saline infusion of pulmonary tissue in rabbits.

MATERIALS AND METHODS

Twenty-eight New Zealand White rabbits were divided into two groups: an RFA group (n=10) and a saline-enhanced RFA (SRFA) group (n=18). In the RFA group, percutaneous RFA of the lung was performed under CT guidance and using a 17-gauge internally cooled electrode. In the SRFA group, 1.5 ml of 0.9% saline was infused slowly through a 21-gauge, polyteflon- coated Chiba needle prior to and during RFA. Lesion size and the healing process were studied in rabbits sacrificed at times from the day following treatment to three weeks after, and any complications were noted.

RESULTS

In the SRFA group, the mean diameter (12.5+/-1.6 mm) of acute RF lesions was greater than that of RFA lesions (8.5+/-1.4 mm) (p < .05). The complications arising in 12 cases were pneumothorax (n=8), thermal injury to the chest wall (n=2), hemothorax (n=1), and lung abscess (n=1). Although procedure-related complications tended to occur more frequently in the SRFA group (55.6%) than in the RFA group (20%), the difference was not statistically significant (p = .11).

CONCLUSION

Saline-enhanced RFA of pulmonary tissue in rabbits produces more extensive coagulation necrosis than conventional RFA procedures, without adding substantial risk of serious complications.

Improved method of porcine renal allografting for transplantation research

This study presents a refined, reproducible, and clinically appropriate animal model of renal transplantation. A pair of kidneys are harvested from a donor pig and preserved in Euro-Collins' solution (4 degrees C). After a set period of preservation, the allografts are transplanted to two recipient pigs. The abdomen is entered through a midline incision. The right common iliac artery and vein are dissected and bilateral native nephrectomy is performed. Each allograft is then randomly assigned and transplanted to the recipients. Three minutes before unclamping, 100 mg of furosemide and 10 g of mannitol are given IV. Immediately after reperfusion, urine output is measured for 1 h. The allograft is biopsied and ureteroneocystostomy is created. Cystostomy is then placed using a 16F Foley catheter. The bladder neck is ligated to secure complete diversion of urine, and the abdomen is closed in layers. This kidney transplant model allows an absolutely paired study of the kidney allograft function from the same donor and also collection of pure urine at any time postoperatively, obviating the need for metabolic cages or sedation for urinary collection. This model and its unique modifications allow various transplant studies, including organ preservation, immunosuppressive protocol, and the prevention of reperfusion injury from oxygen free radicals.