Quality and quantity of bone following alveolar distraction osteogenesis in the human mandible

PURPOSE: The purpose of this prospective study on humans were to evaluate (a) the clinical outcome of alveolar distraction osteogenesis for the correction of vertically deficient edentulous mandibular ridges, (b) the clinical outcome of dental implants placed in the distracted areas, and (c) the quality and quantity of the bone that had formed in the distraction gap. MATERIAL AND METHODS: Seven patients presenting vertically deficient edentulous ridges were treated by means of distraction osteogenesis with an intraoral alveolar distractor. Approximately 3 months after consolidation of the distracted segments, 20 ITI solid screw SLA implants were placed in the distracted areas. Three to 4 months later, abutments were connected and prosthetic loading of the implants started. During implant site preparation, bone biopsies were taken at the implant sites with trephine burrs for histologic and histometric analyses. RESULTS: The mean follow-up after the initial prosthetic loading was 18 months (range 12-24 months). The mean bone gain obtained at the end of distraction was 7 mm (range 5-9 mm). The cumulative success rate of implants 2 years after the onset of prosthetic loading was 95%, whereas the survival rate of implants was 100%. The newly formed bone consisted of woven bone reinforced by parallel-fibered bone with bone marrow spaces between the bone trabeculae. The bone area fraction in the distraction region ranged from 21.6% to 57.8% (38.5+/-11.7%). DISCUSSION AND CONCLUSIONS: Results from this study showed that (a) distraction osteogenesis is a reliable technique for the correction of vertically deficient edentulous ridges, (b) the regenerated bone withstood the functional demands of implant loading, (c) survival and success rates of implants placed in the distracted areas were consistent with those of implants placed in native bone, and (d) there is sufficient bone volume and maturity in the distracted region for primary stability of the implant.     

Evaluation of a surgical procedure to measure drug biliary excretion of rats in regulatory safety studies

A surgical procedure was evaluated to allow bile collection from the freely moving male Sprague-Dawley rats for the assessment of drug biliary excretion during regulatory safety studies. A catheter was implanted into the bile duct to divert the bile flow via an exteriorized loop. Following recovery from the surgery and verification of normal hepatic function, the exteriorized catheter was sectioned to allow collection of the bile and replacement with a commercial bile salt solution. Approximately 80% of the catheterized animals (10 females and 10 males) had normal serum liver enzyme levels 2 days after surgery. Then, the effect of acute or repeated administrations of the immunosuppressant tacrolimus on the biliary excretion of 14C diazepam was studied to validate the technique. A first group of 12 rats received an intravenous injection of 10 mg/kg 14C-diazepam and the total and sequential amounts of diazepam excreted in the bile were measured over 72 h. Biliary excretion accounted for 80% of diazepam elimination. These rats were then given an oral administration of 3 mg/kg tacrolimus on days 7 and 8 followed by the same intravenous dose of 14C-diazepam. Another group of 10 catheterized rats was given 21 daily oral doses of 3 mg/kg tacrolimus followed by a single intravenous administration of 14C-diazepam. No significant changes in diazepam biliary excretion were observed following either acute or repeated administration of tacrolimus. This study demonstrates the feasibility of drug biliary excretion investigations under Good Laboratory Practices conditions as a complement to regulatory acute or repeated dose safety studies.     

Validity of radiographic evaluations of bone formation in a rat calvaria osteotomy defect model

OBJECTIVE: The objective of this study was to evaluate the validity of radiographic evaluations of bone formation in a critical-size rat calvaria osteotomy defect model. METHODS: Bilateral, critical-size ( [symbol in text] 6 mm) calvaria osteotomy defects in 30 adult Sprague-Dawley rats treated with a rat platelet-rich plasma preparation or control treatments were evaluated by radiographic and histometric measures following a 4- or 8-week healing interval. Standardized radiographic images of the rat calvaria gross specimens were used to assess bone formation within the defect sites by visual evaluation of the grey scale by three masked examiners. The most central portion of each defect site was subject to histometric analysis using a PC-based image analysis system. Kappa statistics and percentage agreement between the radiographic and histometric analysis were estimated. RESULTS: Radiographic evaluations of bone formation are associated with significant weaknesses poorly representing actual healing events; kappa statistics (0.17) denoting slight agreement beyond chance. Perfect agreement between the histologic and radiographic analysis for defect sites showing complete and partial histologic bone fill was achieved 63% and 50% of the time, respectively. Agreement reached only 20% for sites with no/limited bone fill. When no/limited and partial bone fill occurred, the radiographic analysis tended to overestimate bone fill and underestimate bone fill when complete closure of the defect sites was observed in the histologic analysis. CONCLUSION: Low accuracy was observed when radiographic evaluations were employed in identifying and characterizing bone fill in the rat calvaria osteotomy defects. Assessment of bone healing in animal models aiming at treatment recommendations for clinical application must not solely be based on radiographic analysis, but should be confirmed using histologic observations.     

Effect of chemo- or radiotherapy on sperm parameters of testicular cancer patients

BACKGROUND: The aims of our study were to investigate the short- and long-term effects of chemo- or radiotherapy on spermatogenesis in patients with testicular cancer and to establish any correlation between pre-therapy sperm parameters, histotype and treatment type/intensity and the progress of spermatogenesis during the post-therapy period. METHODS: We evaluated 166 patients affected by testicular cancer, who cryobanked about 1 month after the removal of the cancerous testis and before beginning chemo- (CH group; n = 71) or radiotherapy (RT group; n = 95). RESULTS: For the CH group, there was a statistically significant decrease in sperm parameters, which was most significant 3 months after the end of chemotherapy. For the RT group, this decrease was most relevant 6 months after the end of radiotherapy. Two years after therapy, 3% of the CH group and 6% of the RT group remained azoospermic. To evaluate whether spermatogenesis recovery is a function of baseline semen quality, we divided each group into two subgroups by pre-therapy total sperm count (A, <40 x 10(6)/ejaculate; B, >or=40 x 10(6)/ejaculate). At t(24), subgroup A of both the CH and RT groups showed improved sperm parameters over the baseline, whereas subgroup B for both CH and RT groups showed a return of sperm parameters to those of baseline values. CONCLUSIONS: In conclusion, the recovery of spermatogenesis after chemo- or radiotherapy in our group of testicular cancer patients was not a function of pre-therapy sperm parameter quality. Cryopreservation of sperm before performing such therapy is therefore imperative.     

Clinical symptoms in celiac patients on a gluten-free diet

Objective. Persistent villous atrophy in patients with celiac disease (CD) on a gluten-free diet (GFD) is reported with increasing frequency. The aim of this study was to evaluate a possible association between persistent damage of the villi and “atypical” gastrointestinal symptoms in CD patients on a GFD. Material and methods. Sixty-nine CD patients on a GFD were divided into two groups: Group A included 42 patients (6 M, 36 F, age range 17–62 years) undergoing esophagogastroduodenoscopies (EGDs) due to the presence of symptoms; Group B included 27 control patients (6 M, 21 F, age range 24–71 years) who were asymptomatic at the time of the study. Both groups underwent EGDs and a duodenal histologic study. Results. Persistent endoscopic lesions were more frequent in Group A (30/42) than in Group B (12/27; p=0.01). Villous atrophy was significantly more frequent in Group A than in Group B: 85% versus 33% (p<0.0001; odds ratio (OR)=12; 95% CI 3.7–38.9). Gastrointestinal symptoms in the Group A patients were different from those present at CD diagnosis: anemia/diarrhea/weight loss in 6 cases; gastroesophageal reflux disease (GERD)-like symptoms in 12 cases; abdominal pain/constipation in 24 cases. In Group A there was no difference in gender distribution, age and duration of GFD between subjects with normal villi and those with persistent partial villous atrophy. Patients with persistent symptoms showed a higher intraepithelial eosinophil count (p=0.005) than the asymptomatic patients (p=0.01). Conclusions. Persistent intestinal villous atrophy in CD patients on a GFD is associated with gastrointestinal symptoms considered “atypical” for CD and not present at CD diagnosis.     

应用DWI早期发现SD大鼠单侧睾丸扭转后对侧睾丸损伤的研究

目的证明单侧睾丸扭转后对侧睾丸存在损伤,寻找有效、无创的影像学方法了解对侧损伤情况。方法40只SD大鼠随机分为假手术组和扭转组,每组20只。二组于术后1h、4h、24h、1周各取5只行磁共振扩散加权成像（DWI）并记录表现扩散系数值,其后处死大鼠,取对侧睾丸行病理评分。结果与假手术组比较,扭转组对侧ADC值、病理评分等指标均有不同程度升高,且两者经Pearson法证实存在正相关。结论单侧睾丸扭转后,对侧睾丸早期即可出现损伤。DWI能有效、连续、无创地评估对侧损伤程度,可协助临床诊治。     

冠状动脉靶病变钙化相关因素分析

目的探讨冠状动脉靶病变钙化与相关凶素的关系。方法50例确诊为冠心病患者,其中男30例,女20例,采用血管内超声虚拟组织学成像（IVUS—VH）测量冠脉靶病变钙化负荷,结合相关因素,采用多元回归分析寻找相关性。结果冠状动脉靶病变钙化与尿酸（P〈0．01）、碱性磷酸酶（P〈0．01）、骨结合蛋白（P=0．027）呈正相关性,与骨保护素（r=-1．1229,P=0．0242）呈负相关。结论尿酸、碱性磷酸酶等因素可能影响冠脉钙化。     

Impact of boric acid exposure at different concentrations on testicular DNA and male rats fertility

Abstract

The aim of this study was to investigate the consequences of exposure to three levels of boric acid (BA) on male rats reproduction, fertility and progeny outcome, with emphasis on testicular DNA level and quality. Adult male rats (12 weeks old) were treated orally with 125, 250 and 500?mg/kg?bwt/d of BA for 60?d. The results indicated that BA administration at 125?mg/kg?bwt had no adverse effects on fertility, sperm characteristics or prenatal development of the impregnated females. However, at dose 250?mg, BA treatment significantly increased serum nitric oxide, testosterone, estradiol levels and testicular boron and calcium levels and also significantly reduced serum arginase activity, sperm quality and testicular DNA content with minor DNA fragmentation. The impact of BA exposure at dose 250?mg on male rats fertility was translated into increases in pre-implantation loss with a resulting decrease in the number of live fetuses/litter. In addition to the significant alteration of biochemical measurements, observed at dose 250?mg, administration of BA at 500?mg caused testicular atrophy, severe damage of spermatogenesis, spermiation failure and significant reduction of Mg and Zn testicular levels. None of the male rats, treated with 500?mg/kg?bwt, could impregnate untreated females, suggesting the occurrence of definitive loss of fertility. In conclusion, BA impaired fertility, in a dose-dependant manner, by targeting the highly proliferative cells, the germ cells, through decreasing DNA synthetic rate rather than the induction of DNA damage.     

Mucosal delivery of cytotoxic therapeutic agents: Response of rat nasal mucosa to microencapsulated ethopropazine HCl enantiomer

Use of microencapsulation technology in combination with absorption enhancers eliminated epithelium irritation and necrosis commonly associated with nasal delivery of cytotoxic therapeutic agents. Phenothiazines, such as ethopropazine (ETZ), promethazine, trimeprazine and propiomazine have been used for the treatment of allergenic conditions, motion sickness, nausea, Parkinson's disease, Prion disease and as a sedative for psychiatric disorders. The enantiomers of commercially available racemic phenothiazines were isolated and purified using classical diastereomeric salt techniques. The racemate and the enantiomers of ETZ were tested in vitro for their cellular toxicity using lung fibroblast cells. Each enantiomer was shown to be cytotoxic at concentrations greater than 10^?5 molar. The ETZ enantiomers were encapsulated using spinning disk atomization to prepare a nasal delivery dosage form that does not produce an irritation response. Release rates for the ETZ microcapsules were determined in vitro and an animal study was conducted to determine the irritation response of rat nasal mucosa when dosed with encapsulated vs. non-encapsulated ETZ.