Effects of low-intensity laser therapy on the orthodontic movement velocity of human teeth: a preliminary study

BACKGROUND AND OBJECTIVES: Low-intensity laser therapy (LILT) has been studied in many fields of dentistry, but to our knowledge, this is the first time that its effects on orthodontic movement velocity in humans are investigated. STUDY DESIGN/PATIENTS AND METHODS: Eleven patients were recruited for this 2-month study. One half of the upper arcade was considered control group (CG) and received mechanical activation of the canine teeth every 30 days. The opposite half received the same mechanical activation and was also irradiated with a diode laser emitting light at 780 nm, during 10 seconds at 20 mW, 5 J/cm2, on 4 days of each month. Data of the biometrical progress of both groups were statistically compared. RESULTS: All patients showed significant higher acceleration of the retraction of canines on the side treated with LILT when compared to the control. CONCLUSIONS: Our findings suggest that LILT does accelerate human teeth movement and could therefore considerably shorten the whole treatment duration.     

Oncogene HER-2 in Canine Mammary Gland Carcinomas

Immunohistochemical (IHC) HER-2/neu protein overexpression was found in 17.6% of canine mammary gland carcinomas, a percentage similar to that observed in human breast carcinoma, but there was no gene amplification by chromogenic in situ hybridization (CISH). Canine mammary carcinoma would be a suitable natural model of that subset of human breast carcinomas with HER-2 protein overexpression without gene amplification.     

Role of canine basal cells in postnatal prostatic development, induction of hyperplasia, and sex hormone-stimulated growth; and the ductal origin of carcinoma

BACKGROUND: The canine prostate has often been proposed as a model for abnormal growth of the human gland. Hyperplasia of the prostate is common in aging men and has been estimated to be present in 100% of old intact dogs. While prostatic carcinoma is common in older men, it appears to be rare in dogs and unlike the disease in humans, it occurs with relatively high frequency in castrated animals. Since basal cells are thought to be key participants in normal and abnormal growth of the human gland, we used immunohistochemistry to investigate the role that they may play in canine prostatic development, the evolution of hyperplasia and carcinoma, and the effects of sex hormones on these cells. METHODS: Prostate specimens were obtained at autopsy from seven sexually immature dogs, autopsy and biopsy samples from 14 sexually mature intact animals, from four castrates, and from19 dogs with prostatic carcinoma. In addition, we also studied the prostates from two intact dogs treated with 5alpha-dihydrotestosterone (DHT) for 6 months and two castrated dogs that were subsequently treated with 5alpha-androstane-3alpha diol and estradiol-17alpha, as well as specimens from two sexually ablated animals given DHT for 2 weeks. All specimens were immunostained for high molecular weight cytokeratin (HMC), pancytokeratin, androgen receptor (AR), and the proliferative marker KI-67. RESULTS: We find that basal cells are the major proliferative cell type in the neonatal and adult canine prostate and that the expression of HMC staining, which defines these cells, may be regulated by androgens. In the adult gland, ductal basal cells formed a contiguous layer, whereas those lining acini were discontinuous. Populations of both basal cell types were variably AR positive, but while HMC immunostaining was abolished in acinar cells following long-term castration, staining remained in ductal cell counterparts. Paralleling the histological development of hyperplasia, the acinar basal cell population increased with age and were the major cell type that expressed KI-67. In contrast, ductal basal cell populations did not expand in the prostates of older dogs and were seldom positively stained for KI-67. The numbers of HMC and KI-67-stained acinar basal cells were dramatically increased in the prostates of intact dogs treated with DHT when compared with glands of untreated controls. This was not the case with ductal basal cells. Androgens given alone or together with estrogen to castrated dogs induced widespread HMC and KI-67 immunostaining in both populations of basal cells. In addition, our results indicate that the majority of canine prostatic carcinomas likely arise exclusively from ductal epithelium. Only one of the 19 cases of carcinoma contained cells that expressed AR, which suggests that androgens may not be required for the initiation or progression of these cancers. CONCLUSIONS: Our findings indicate that two biologically distinct populations of basal cells may exist in the canine prostate. In this regard, the age-related expansion of proliferating acinar basal cell populations, probably mediated by sex steroids, is a key factor in the pathogenesis of canine prostatic hyperplasia. Additionally, we find that prostatic carcinoma in the dog likely arises from ductal cells. Taken together, these findings may indicate that canine acinar basal cells and ductal epithelium have separate susceptibilities to factors that promote hyperplastic or neoplastic development.     

Role of canine basal cells in prostatic post natal development, induction of hyperplasia, sex hormone-stimulated growth; and the ductal origin of carcinoma

BACKGROUND: The canine prostate has often been proposed as a model for abnormal growth of the human gland. Hyperplasia of the prostate is common in aging men and has been estimated to be present in 100% of old intact dogs. While prostatic carcinoma is common in older men it appears to be rare in dogs and unlike the disease in humans it occurs with relatively high frequency in castrated animals. Since basal cells are thought to be key participants in normal and abnormal growth of the human gland, we used immunohistochemistry to investigate the role that they may play in canine prostatic development, the evolution of hyperplasia and carcinoma, and the effects of sex hormones on these cells. METHODS: Prostate specimens were obtained at autopsy from seven sexually immature dogs, autopsy and biopsy samples from 14 sexually mature intact animals, from four castrates, and from 19 dogs with prostatic carcinoma. In addition, we also studied the prostates from two intact dogs treated with 5 alpha-dihydrotestosterone (DHT) for 6 months and two castrated dogs that were subsequently treated with 5 alpha-androstane-3 alpha diol and estradiol-17 alpha as well as specimens from two sexually ablated animals given DHT for 2 weeks. All specimens were immunostained for high molecular weight cytokeratin (HMC), Pancytokeratin, androgen receptor (AR), and the proliferative marker KI-67. RESULTS: We find that basal cells are the major proliferative cell type in the neonatal and adult canine prostate and that the expression of HMC staining, which defines these cells, may be regulated by androgens. In the adult gland, ductal basal cells formed a contiguous layer whereas those lining acini were discontinuous. Populations of both basal cell types were variably AR positive but while HMC immunostaining was abolished in acinar cells following long-term castration, staining remained in ductal cell counterparts. Paralleling the histological development of hyperplasia, the acinar basal cell population increased with age and were the major cell type that expressed KI-67. In contrast, ductal basal cell populations did not expand in the prostates of older dogs and were seldom positively stained for KI-67. The numbers of HMC and KI-67-stained acinar basal cells were dramatically increased in the prostates of intact dogs treated with DHT when compared with glands of untreated controls. This was not the case with ductal basal cells. Androgens given alone or together with estrogen to castrated dogs induced widespread HMC and KI-67 immunostaining in both populations of basal cells. In addition, our results indicate that the majority of canine prostatic carcinomas likely arise exclusively from ductal epithelium. Only one of the 19 cases of carcinoma contained cells that expressed AR which suggests that androgens may not be required for the initiation or progression of these cancers. CONCLUSIONS: Our findings indicate that two biologically distinct populations of basal cells may exist in the canine prostate. In this regard the age-related expansion of proliferating acinar basal cell populations, probably mediated by sex steroids, is a key factor in the pathogenesis of canine prostatic hyperplasia. Additionally we find that prostatic carcinoma in the dog likely arises from ductal cells. Taken together these findings may indicate that canine acinar basal cells and ductal epithelium have separate susceptibilities to factors that promote hyperplastic or neoplastic development. Prostate 47:149-163, 2001.     

The comparative effects of drive and test stimulus intensity on myocardial excitability and vulnerability

The number and intensity of stimuli that set basic cycle length in cardiac electrophysiological studies can influence the electrical properties assessed by extrastimuli. The relative contribution of drive (S1) and test (S2) stimulus intensity in defining myocardial excitability and vulnerability has not been reported. The purpose of this investigation was to assess this interaction and to determine whether atrial and ventricular findings differed. The effects of S1 and S2 intensity on atrial and ventricular stimulus-intensity-refractory-period curves were determined in open-chest dogs: comparisons were made between curves with S1 intensity varied between diastolic threshold (DT) and 10 mA and S2 intensity maintained at DT and those with S1 intensity maintained at DT and S2 intensity varied between DT and 10 mA. S1-S1 was held constant and S1-S2 varied. The effects of different stimulation sites, cycle length, number of stimulations, and neural blockade were assessed. S1 intensity amplification shifted atrial stimulus-intensity-refractory period curves in the direction of increased excitability and vulnerability; the changes were more pronounced than those obtained by modulating S2 intensity. The changes produced by increasing S1 intensity were evident at different cycle lengths and were enhanced by an increased number of stimulations, but were not evident when S1 and S2 were delivered at different atrial sites. Although beta-blockade attenuated the effects of increasing S1 intensity somewhat, the addition of cholinergic blockade virtually abolished it. Ventricular refractoriness was also changed by modulation of S1 intensity, but the changes were less striking. In the atrium, modulation of S1 intensity has greater effects of stimulus-intensity-refractory-period relations than modulation of S2 intensity; in the ventricule, the converse is true.     

螺旋弹簧和橡皮链拉尖牙向远中的临床效果研究

目的研究Ni-Ti螺旋弹簧和橡皮链施力后,尖牙远中移动速率、龈沟液(gingival crevicular fluid,GCF)中碱性磷酸酶(alkaline phosphatase,ALP)活性,探讨不同持续张力的正畸效果和生物学效应。方法用OPAK直丝弓矫治技术托槽,排齐整平后,采用0.018×0.025″SS的Ni-Ti方丝进行尖牙远中移动。然后,用初始力150g的Ni-Ti螺旋弹簧和橡皮链牵引尖牙向远中,21d后,采用游标卡尺测定牙齿移动距离,Beckman全自动生化分析仪检测龈沟液中碱性磷酸酶(GCF-ALP)的活性。结果螺旋弹簧和橡皮链施力21d后,尖牙向远中移动距离差异有显著性(P<0.05)。在螺旋弹簧和橡皮链持续牵引力作用下,GCF-ALP活性随时间推移逐渐增加,6个月时达到最高水平,与加力前比较,差异有显著性(P<0.05);6个月后,GCF-ALP开始下降,12个月时,橡皮链加力侧GCF-ALP活性基本恢复到加力前的水平。但在6和12个月时,GCF-ALP活性在螺旋弹簧施力侧显著高于橡皮链施力侧,差异有显著性(P<0.01)。结论螺旋弹簧拉尖牙向远中移动速率较快,产生的生物学效应较强而持久。     

Recording of electroencephalograms and electrocardiograms during daytime sleep in trained canines: Preparation of the sleeping dogs

Abstract  Although respiration in trained canines is well investigated, the process of preparing dogs has not been described in any great detail. Moreover, their daytime patterns of sleep and wakefulness during 1 or 2 h of electroencephalogram (EEG) and electrocardiogram (ECG) recordings are not clear. Therefore, we describe the process of selecting and training dogs, in which we recorded EEG and ECG in the laboratory. First, 14 of 1242 dogs dealt with over a 1 year period were chosen. They were trained for 2 h to lie quietly and to sleep in the laboratory; this training procedure was repeated 152 times. Three dogs were then selected and a permanent tracheostomy was performed in one. Finally, EEG and ECG were recorded with the bipolar fine needle electrodes; respiration was recorded simultaneously through a tube inserted to a tracheostomy in one dog. Wakefulness, slow wave sleep (SWS) and rapid eye movement (REM) sleep (REMS) were identified according to the EEG pattern and on the basis of the behavioral criteria. Recordings were performed 12 or 13 times in each dog. Complete sleep cycles, including wakefulness, SWS and REMS in this sequence, were observed 3.9–4.1 times. The mean duration of SWS was 2.2–4.4 min and that of REMS was 3.5–4.6 min. The REMS latency was 33.9–41.8 min. Fluctuation of heart rate with respiration, termed respiratory sinus arrhythmia, was noted in the ECG. Heart beat increased with inspiration and decreased with expiration. The present study demonstrates how to select and train sleeping dogs and shows their undisturbed daytime sleep and wakefulness patterns.     

消旋聚乳酸输尿管支架管在家犬体内的降解变化及输尿管病理学表现

目的观察消旋聚乳酸输尿管支架管在家犬输尿管内的降解变化以及输尿管组织病理学表现。方法经手术将消旋聚乳酸输尿管支架管置于19只家犬输尿管内,每2周取出支架管在电镜下观察支架管材料结构的降解变化,并经凝胶渗透色谱仪测量支架管相对分子质量变化。同时切取输尿管组织在光镜下观察其病理改变。结果支架管降解前相对分子质量为68900,第7周相对分子质量降解为8033,降解率达到88.3%。电镜下支架管表面的孔隙逐渐增多增大,材料不断被浸析降解。输尿管组织病理学变化主要表现为无菌性炎症。结论消旋聚乳酸输尿管支架管具有良好的动物体内降解性能和组织相容性。     

Serological Evidence of Canine Herpesvirus‐1 in Dogs of Kerman City,South‐east of Iran

Canine herpes virus‐1 (CHV‐1) is an alphaherpesvirus, which causes foetal and neonatal death as well as fertility problems in dogs. The virus is presumed to be enzootic in dogs all over the world, but no information was found about the seroprevalence of CHV‐1 from middle‐east countries. Therefore, this study was aimed to determine the seroprevalence of CHV‐1 among dogs in Kerman (south‐east of Iran). Blood samples were taken from 47 privately owned and 35 kennelled dogs, respectively. The entire sampled dogs were apparently healthy. Indirect immunofluorescence antibody (IFA) assay was used to detect antibodies against CHV‐1 in all sera. The overall CHV‐1 seroprevalence was estimated 20.7%, which was 22.9% and 19.1% for kennelled and owned dogs, respectively. Sex, parity and raising status (owned or kennels) did not differ significantly between seropositive and seronegative dogs. However, the infection rate was significantly higher in dogs older than 3 in comparison with younger groups (15.9% vs. 4.8%, P ≤ 0.05). In conclusion, this study revealed that CHV‐1 could be considered endemic in Iran, and more epidemiological researches are needed to identify the geographical distribution of diseases in Iran.