Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Analysis of Variance”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,297 records · Page 72Linked to original sources
PubMed2003

Depolarization-induced long-term depression at hippocampal mossy fiber-CA3 pyramidal neuron synapses.

Hippocampal CA3 pyramidal neurons receive two types of excitatory afferent innervation: mossy fibers (MFs) from granule cells of the dentate gyrus and recurrent collateral fibers (CFs) from other CA3 pyramidal neurons. At CF-CA3 pyramidal neuron synapses, membrane depolarization paired with low (0.33 Hz) presynaptic stimulation generated a heterogeneous response that ranged from long-term potentiation (LTP), long-term depression (LTD), to no alteration of synaptic strength. However, the same induction paradigm applied at MF-CA3 pyramidal neuron synapses consistently induced LTD. This novel form of LTD was independent of NMDARs, mGluRs, cannabinoid receptors, opioid receptors, or coincident synaptic activity, but was dependent on postsynaptic Ca2+ elevation through L-type Ca2+ channels and release from inositol 1,4,5-trisphosphate receptor-sensitive intracellular stores. Ca2+ imaging of both proximal and distal CA3 pyramidal neuron dendrites demonstrated that the depolarizing induction paradigm differentially elevated intracellular Ca2+ levels. L-type Ca2+ channel activation was observed only at the most proximal locations where mossy fibers make synapses. Depolarization-induced LTD did not occlude the conventional 1 Hz-induced LTD or vice versa, suggesting independent mechanisms underlie each form of plasticity. The paired-pulse ratio and coefficient of variation of synaptic transmission were unchanged after LTD induction, suggesting that the expression locus of LTD is postsynaptic. Moreover, peak-scaled nonstationary variance analysis indicated that depolarization-induced LTD correlated with a reduction in postsynaptic AMPA receptor numbers without a change in AMPA receptor conductance. Our results suggest that this novel form of LTD is selectively expressed at proximal dendritic locations closely associated with L-type Ca2+ channels.

Animals↗
PubMed2003

[A study on the role of vascular endothelial growth factor in emphysema of rat caused by smog exposure].

OBJECTIVE: To explore the role of vascular endothelial growth factor (VEGF) in emphysema of rat caused by smog exposure. METHODS: Thirty-six 12-week male rats were randomly divided into 2 groups: a smog exposure group (S group), and a normal control group (N group). S group rats were randomly subdivided into 3 groups: S(1) group, S(2) group, S(3) group, which were exposed to smog for 2 weeks, 4 weeks, 8 weeks, respectively; N group rats were randomly subdivided into 3 groups: N(1) group, N(2) group, N(3) group, which were raised in normal oxygen condition for 0 week, 4 weeks, 8 weeks, respectively. The expressions of VEGF mRNA and VEGF protein and kinase-insert domain containing receptor (KDR) protein were determined by reverse transcription-polymerase chain reaction (RT-PCR) and modified SABC immunohistochemistry assay separately. The pathological change in smog exposure rat lung was determined by HE staining. MLI and MAN were determined as an index of emphysema. Variance analysis, nonparametric analysis and correlate analysis were conducted in SPSS 10.0. RESULTS: (1) There were airway inflammation in S group rat lungs, and an early-emphysema-like change in S(3) group rat lungs: MAN in S(3) group was significantly decreased compared with N(3) group, MLI in S(3) group was significantly increased compared with N(3) group (P < 0.05). (2) VEGF189 mRNA in lung and VEGF protein in alveolar and bronchial epithelium of rats in S(1) group were significantly lower than those in N(1) group (P < 0.01); VEGF189 mRNA, VEGF165 mRNA and VEGF121 mRNA of lung tissue and VEGF protein in alveolar and bronchial epithelium of rats in S(2) group were significantly lower than those in N(2) group (P < 0.01), too; VEGF protein in alveolar and bronchial epithelium and KDR expression in pulmonary vascular endothelium of rats in S(3) group was lower than that in N(3) group (P < 0.01, P < 0.01, P < 0.05), but VEGF mRNA have no difference (P > 0.05). (3) VEGF protein expression in alveolar epithelium and bronchial epithelium had a positive correlation with MAN (r = 0.43, r = 0.37, P < 0.05) and an inverse correlation with MLI (r = -0.42, r = -0.37, P < 0.05). CONCLUSIONS: Smog exposure decrease the expression of VEGF and KDR in rat lung. VEGF might involve in the pathology of emphysema caused by smog exposure.

Animals↗
PubMed2003

[A factors study of root resorption after orthodontic treatment].

OBJECTIVE: To investigate the factors relating to root resorption after orthodontic treatment. METHODS: 96 cases treated with fixed appliances were selected. The panoramic radiographs before and after treatment were examined. The relationship between root resorption after treatment (RRAT) and the variables including sex, age, extraction or nonextraction approach, tooth location, treatment duration and the root resorption before treatment (RRBT) were analyzed by multiple variance analysis and stepwise multivariate linear regression analyses. RESULTS: (1) There were statistically significant differences in root resorption in relation to gender (estimate of RRAT for female: 0.41, that for male: 0.34), extraction (estimate of RRAT for the extraction group: 0.43, that for non-extraction: 0.31), anterior or posterior teeth (estimate of RRAT for the anterior teeth: 0.59, that for the posterior teeth: 0.12). (2) The estimate of RRAT for the upper teeth was 0.40, and that for the lower teeth was 0.37. There were no statistically significant differences. (3) Using multiple regression analysis, age, duration and RRBT were associated with RRAT (R = 0.59, R(2) = 0.35). CONCLUSIONS: (1) Factors including gender, extraction or not and anterior or posterior teeth have influences on the RRAT. More root resorption was found in female or extraction cases. Anterior teeth were more susceptible to root resorption relative to posterior teeth. (2) Age, treatment duration and RRBT can explain approximately 35% of the RRAT. Root resorption aggregated when it was present before treatment. The age and treatment duration were lightly related to the root resorption.

Adolescent↗
PubMed2004

Joint laxity and the benign joint hypermobility syndrome in student and professional ballet dancers.

OBJECTIVE: To ascertain the prevalence of hypermobility and the benign joint hypermobility syndrome (BJHS) in male and female student and professional ballet dancers, and explore whether BJHS has any effect on a dance career. METHODS: Students from the Royal Ballet School and professional dancers from the Royal Ballet Company, London, were compared with a control group of teenagers and adults from a local secondary school and The Royal Opera House, respectively. The data, examined by variance analysis, included anthropometric variables, the Beighton score, and clinical features constituting BJHS. Odds ratios for hypermobility and BJHS in dancers were calculated, and the prevalence and distribution of BJHS was examined. RESULTS: Hypermobility and BJHS were common in male and female dancers compared with controls. An OR of 11.0 (95% CI 3.3-31.8) was found for hypermobility in dancers for both the ballet school and the professional company. The prevalence of BJHS was found to decline both from student to professional and within the ballet company from corps de ballet to Principal. Odds ratios for BJHS in student dancers were significant, OR = 3.9 (95% CI 1.3-11.3), but not so in professional dancers: OR = 1.7 (95% CI 0.6-4.7). Arthralgia was common in dancers and was reported more often in males than females. In females, pain was reported most by dancers with other features of BJHS, in particular stretchy skin. CONCLUSION: Hypermobility and BJHS are common in both male and female student and professional ballet dancers. The fall in prevalence, and the greater reporting of arthralgia with other features of BJHS in young female dancers, suggests that BJHS may have an important negative influence, and this may have implications for training. The same pattern was not observed in males, suggesting that their pain-reporting and injury are related to factors other than BJHS.

Arthralgia↗
PubMed2003

Release of hydroxyl ions from calcium hydroxide preparations used in endodontic treatment.

PURPOSE: The purpose of our study was to compare the in vitro release of hydroxyl ions from several calcium hydroxide preparations used in endodontic treatment. MATERIAL AND METHODS: Equal quantities of the materials--nonsetting (pure calcium hydroxide, Biopulp, Calcicure), setting--canal sealers (Sealapex, Apexit) and points were placed in dialysis tubes which were then immersed in deionized water. The release of hydroxyl ions from the preparations was measured by the median pH of the deionized water used for dialysis, by means of a pH-meter. The results of our study were analyzed by means of Tukey's reasonable correlation. Significance difference (one-way variance analysis ANOVA) and Pearson's linear correlation coefficient (r2). RESULTS: Nonsetting preparations of calcium hydroxide have a significantly higher capability of hydroxyl ions release in comparison with sealers and points, irrespective of time (p < 0.05). Sealapex and "plus" points released hydroxyl ions to a much greater extent than both Apexit and "regular" points at most periods of the experiment (p < 0.05). Apexit released significantly more of hydroxyl ions than "regular" points, and Sealapex more than "plus" points in the later periods of the experiment (p < 0.05). The pH values of dialysis samples of all materials correlated positively with time and the pH. Almost all materials reached a maximum on the 8-th day of the experiment. CONCLUSIONS: To achieve maximum concentration of hydroxyl ions in tissues: for temporary root fillings nonsetting preparations of calcium hydroxide should be chosen rather than points and they should be placed for at least one week, for permanent root fillings it is more recommended to use Sealapex than Apexit as a sealer.

Calcium Hydroxide↗
PubMed1992

[Nuclear size and character of the nucleolar organizer in benign and malignant follicular tumors of the thyroid gland].

Histologic sections of 11 benign and 11 malignant follicular tumours of the thyroid were compared from the point of view of subsequent practising cytologic diagnosis. Following features were analysed in 100 randomly chosen thyreocytic nuclei: maximal nuclear diameter, nucleolar organizer rates (AgNOR) inside and outside the nucleoli, total AgNOR according to a modified Crocker s et al. method, total nucleolar rate and maximal nucleolar diameter, proportion of maximal nucleolar diameter and maximal nuclear diameter, AgNOR in vicinal nontumorous thyreocytes. All of them except total AgNOR did not show any significant differences according to modified t-test. But the increase of total AgNOR in follicular carcinomas lost its significance in Duncan's test of variance analysis because of a high maximal nucleolar diameter regarding big figures in 4 carcinomas (2 of them oxyphilic celled). In most tumours AgNOR inside nucleoli could not be reliably distinguished and quantified even after shortening of silver impregnation. Mean maximal nuclear diameter bigger than 7 nm, indicating malignant follicular lesion according to literature, could not be verified in 8 tumours- it was smaller in 5 carcinomas and bigger in 3 benign tumours. Proportion of maximal nucleolar diameter and maximal nuclear diameter was stable in benign and malignant tumours as well as the AgNOR in peritumorous thyreocytes. All the analysed nuclear features are lacking in sufficient prediction value for distinction of benign and malignant follicular tumours of the thyroid.

Cell Nucleus↗
PubMedDate not supplied

Bacterial infections associated with hepatic encephalopathy: prevalence and outcome.

Hepatic encephalopathy (HE) is a major sign of severe liver disease and the impact of associated bacterial infections should be better evaluated. A retrospective cohort of 333 patients with cirrhosis and HE was analyzed in three periods of time, from 1984 to 1998. Variance analysis, Wilcoxon, Chi-square and Fisher's exact tests were used for statistical comparisons. Prevalence of bacterial infections decreased along the time (p = 0.0029). Spontaneous Bacterial Peritonitis -SBP- (37%) and urinary tract infection (30%) were the more frequent types of bacterial infections. Early death was significantly higher in HE with infection (46,47%) and the calculated RR was 2.047. Prognosis was worse in septicemia (79%) and respiratory tract infection (50%) and better in urinary tract infection (27%). SBP lethality was reduced from 70% to 38% (p = 0.062). In conclusion, lower prevalence of bacterial infections, in severe liver disease, was achieved in the last decade, but short-term prognosis remains bad, varying according to the type of bacterial infection.

Adolescent↗
PubMed2004

[Comparison of body-image self-perception and BMI of dieting adolescents with those of non-dieters].

INTRODUCTION: Our main objective was to determine the relationship between body image, self-perception and body mass index in dieting adolescents and non-dieters. METHOD: 531 high-school students 15-17 years old were selected randomly and evaluated by Self-Perception Profile for Adolescents, Body Image Satisfaction Questionnaire, (BISQ) Dieting Status Measure (DiSM) and ideal body weight. Multivariate variance analysis for the effect of gender, age and dieting status on SPPA and BISQ subscales and multiple regression analysis for determining the predictors of dieting were used. RESULTS: 33% of girls of normal weight reported that they were dieting. The percentage of dieters among female adolescents was significantly higher than that among male adolescents. While female adolescents were dieting for a thinner body ideal, boys were dieting for a thinner or fatter body ideal. In the dieting groups, lower body image satisfaction and self-worth were determined the physical appearance and general self-worth domains of the SPPA were the predicting factors of body image satisfaction in both female and male groups. CONCLUSION: The percentage of girls who have a thinner body ideal and are dissatisfied with their actual body weight is considerable and is close to those in developed countries. The relationship between body image, self-perception and body mass index in dieting groups may help us to understand the psychopathology of eating disorders.

Adolescent↗
PubMedDate not supplied

[Epidemiological profile of epilepsy in a hospital population in Lima, Peru].

INTRODUCTION: Epilepsy is a chronic disorder with important personal and collective consequences. Its epidemiology has received widespread attention in numerous studies concerning the general population, but not in hospitals, where the population differs in the way it must be handled and followed up. AIMS: The main purpose of this study was to determine the characteristics of patients with a discharge diagnosis of epilepsy and the prevalence of the different types of epilepsy according to age groups. PATIENTS AND METHODS: We conducted a descriptive, retrospective study based on the discharge registry of 121 patients with a discharge diagnosis of epilepsy who were attended in the Neurology Unit at the Hospital Nacional Guillermo Almenara between January 2000 and December 2001. The variables obtained were age, sex, age of onset of seizures and the kind of seizures. The mean, standard deviation and variance analysis were employed, according to the type of variable used. RESULTS: The patients were between 3 and 90 years old (mean: 40.79 years), the male/female ratio was 65/56 (1.16:1). Age at onset of the seizures varied from 1 90 years (mean: 36.6). Predominance of partial seizures (52.07%), followed by generalised clonic tonic seizures (47.11%). Of the partial seizures, 33.33% were simple partial, 14.29% were complex partial and 52.38% were secondarily generalised; no significant differences were found according to age groups. CONCLUSIONS: The epidemiological profile of hospitalised patients diagnosed as suffering from epilepsy is similar to that observed in the population outside the hospital, and there are no variations from one age bracket to another. There is a need for further complementary studies to help in the development of a correct classification.

Adolescent↗
PubMed2004

[Pharmacokinetics and bioequivalence of trimebutine dispersive tablet in healthy subjects].

AIM: To develop an HPLC-ESI-MS assay for determination of trimebutine in human plasma and to investigate the pharmacokinetics and bioequivalence of two trimebutine tablets in human. METHODS: After being made alkaline with saturated sodium bicarbonate, plasma was extracted by cyclohexane and separated by HPLC on a reversed-phase C18 column with a mobile phase of 10 mmol x L(-1) ammonium acetate buffer solution (pH 3.5)-methanol (18:82). HPLC-ESI-MS was performed in the selected ion monitoring (SIM) mode using target ions at m/z 388 for trimebutine and m/z 280 for the internal standard (sibutramine, IS). The fragmentor voltage was 50 V. A randomized cross-over design was performed in 20 healthy volunteers. In the two study periods, a single 100 mg dose of each tablet was administered to each volunteer. RESULTS: Calibration curve was linear over the range of 0.3 - 150 microg x L(-1). The main pharmacokinetic parameters of T1/2, Tmax and Cmax were (9.2 +/- 2.8) h, (1.0 +/- 0.3) h and (40 +/- 20) microg x L(-1) for the reference tablet; (9.2 +/- 2.3) h, (0.9 +/- 0.4) h and (41 +/- 20) microg x L(-1) for the test tablet. The relative bioavalability of the test tablet was (97 +/- 13)%. The results of variance analysis and two one-sided t-test showed that there was no significant difference between the two formulations in the AUC and Cmax. CONCLUSION: The assay was proved to be sensitive, accurate and convenient. The two formulations were bioequivalent.

Adult↗
PubMed2004

[Statins in dyslipidemia associated with acute myocardial infarct].

Long time ago lipids increased in blood have been known as risk factor for atherosclerosis that causes coronary heart disease among which myocardial infarction is the most complicated. Aim were to present the lipids status structure in patients with acute myocardial infarction and on the basis of that to suggest corresponding statin in treatment. Our research involved 202 patients with acute myocardial infarction, patients were both gender and from 37 to 89 year. Out of total number of patients, 100 of them were with anterior myocardial infarction (group I) and 102 with inferior myocardial infarction (group II). Whole cholesterol, low density lipoproteins, high density lipoproteins and triglycerides were followed. Hi square test and variance analysis were used to prove statistically significant difference. In the sample of group I increased LDL was found in 92 patients and increased TGL in 46 patients while decreased HDL was found in 61 patients. In the sample of group II increased LDL was found in 64 patients, increased TGL in 44 patients, while decreased HDL was found in 51 patients. We analysed the next combinations in both groups: LDL > with HDL <; LDL > with TGL >; HDL < with TGL >; LDL >, TGL > with HDL <. Combination decreased HDL with increased TGL was found in group I in 5 patients, and in group II in 12 patients. Other combinations in both groups were similarly values. On the basis of the obtained results we found statistically significant difference between the two groups of patients. Patients in group I have more frequently increased values of LDL in comparison to patients in group II (p < 0.00005). In patients in group II who had decreased HDL and increased TGL statistically significant difference was found in comparison to the patients in group I (p < 0.02). On the basis of the obtained results and up to now studies on statins effects we suggest Atorvastatin for treatment the patients with anterior myocardial infarction, increased LDL with normal values of HDL and Simvastatin for treatment the patients with inferior myocardial infarction, decreased HDL.

Adult↗
PubMedDate not supplied

[Comparison between a diet with mainly vegetal protein content and a diet with mainly animal protein content in hepatic cirrhosis].

Eight cirrhotic patients were studied in a randomized crossover single blind study in order to compare the effects of two isocaloric, and with equal amount of protein diets on nitrogen balance and on the portal systemic index. One diet was 2:3 vegetable protein to total protein content (diet V) and the other 2:3 animal protein to total protein content (diet A). Each diet was changed every three weeks. Five patients followed the VAV scheme and three the AVA scheme. The mean values of the porto systemic index were almost the same with the two diets while the value of the nitrogen balance was less negative with the diet A than with the diet V, showing an increasing trend, more marked with the diet A, at every consecutive time of observation. The variance analysis was not significant for any of the two diets. Diet V was well tolerated.

Aged↗
PubMedDate not supplied

[Effect of phloroglucinol on rectosigmoid motility stimulated by a test meal. Study in patients with irritable bowel syndrome].

Twenty patients (15 women, 5 men, mean age: 46.3 +/- 11.82 years, mean weight: 70.9 +/- 8.83 kg) presenting with a 8.5 +/- 4.7 years' history of irritable bowel syndrome associated predominantly with postprandial abdominal pain were recruited into the study. They underwent, after an enema, a rectosigmoid manometry (4 channels, low compliant infusion pump and catheters) before and after a 1000 kcal standardized meal. At the end of the meal they were administered intravenously phloroglucinol (two 40 mg ampoules) or placebo (two ampoules). Both treatments were strictly similar and the order of administration was randomly assigned Motor activity at the rectum, rectosigmoid, lower sigmoid and sigmoid level was determined using a motor index calculated for each 15 min period. Three preprandial and four postprandial indices were calculated. Both groups were statistically similar for sex ratio, age and history of disease. A slight difference was noted for mean weight: the caloric instake per kg of weight was a little higher in the phloroglucinol group. Mean preprandial indices were comparable in both groups. Variance analysis showed that the increase in postprandial motor indices was statistically less pronounced in the phloroglucinol group than in the placebo group. In the placebo group a clear cut increase in motor activity was assessed, which was not observed in the phloroglucinol group. This variation of motricity, which was observed at every level, was more pronounced for the first two postprandial indices than for the last two ones. These results suggest that phloroglucinol is able to reduce rectosigmoid motor response after a test meal. This could explain its activity in abdominal pain associated with irritable bowel syndrome.

Adult↗
PubMed2004

[Apoptosis of peripheral blood cells of children with viral pneumonia].

BACKGROUND: To study apoptosis of peripheral blood cells of children with viral pneumonia, explore immunopathogenesis and the possibility of immunotherapy of patients with viral pneumonia. METHODS: Fresh peripheral blood samples were collected from 28 patients with viral pneumonia and 24 healthy children were treated and run through the flow cytometry. The data were acquired using Cell Quest software and the percentage of live cells, viable apoptotic cells, non-viable apoptotic cells and dead cells of neutrophils and lymphocytes were counted. The patients with viral pneumonia were hospitalized at our hospital. The average age of patients was 1.3 years; 24 healthy children were served as control group (age 1.8 years, on average). T-test and variance analysis by SPSS FOR WINDOWS 10.0 software was used for statistical analysis. RESULTS: The percentage of live neutrophils and lymphocytes in the acute stage and recovery stage in patients were significantly lower than that in control group (P < 0.01). The percentage of viable apoptotic neutrophils and lymphocytes in two stages in patients were significantly higher than that in control group (P < 0.05). Except for the percentage of live cells, non-viable apoptotic cells and dead lymphocytes, others had no difference between the patients and control groups. CONCLUSION: Apoptosis of neutrophils and lymphocytes of peripheral blood cells of children with viral pneumonia increased. Whereas the percentage of live cells decreased. Drugs that can accelerate apoptosis may be helpful in treatment of viral pneumonia.

Apoptosis↗
PubMedDate not supplied

[Hydro-cellular dressing and silver sulfadiazine. Evaluation of its combination in the treatment of infected skin ulcers].

The authors carried out an observational, descriptive, prospective and multi-centric study on 49 infected lesions which had clinical signs of local infection as well as infection from a positive sprinkler method culture. These lesions were treated over a three week period with argentic sulfadiazine and a semi-permeable dressing; afterward, treatment continued for seven weeks more based on cures in a humid environment by means of a semi-permeable dressing. After three weeks of treatment, two-thirds of these lesions showed a negative exudative culture, the number of strains present in the rest of the cultures diminished to at least half of those present at the start of this study. 15 of these lesions completely closed over during the period of study (mean = 46.73 +/- 22.74 days) and the absolute cicatrisation surface area varied, on average, from 23.46 square cm at the start to 12.39 square cm at the end of this study. In relation to the relative cicatrisation an average reduction of 76.5% (IC 95= (66.85% - 86.2%)) occurred. Variance analysis (ANOVA) over repeated measurements established significant differences (p = 0.001) having a tendency toward a lineal decrease. The authors also found statistically significant differences regarding the mean relative cicatrisation in the subgroup having lesions which stopped being infected during the third week of treatment when compared to those lesions which continued being infected. In conclusion, the authors state the topical treatment using argentic sulfadiazine in combination with a semi-permeable dressing has been favorable in treating two of every three lesions which stopped being infected in the third week of treatment, furthermore, this treatment produced a reduction in the size of these lesions, both in terms of the absolute mean cicatrisation area as in the relative mean cicatrisation area cicatrisation area for the lesion group in this study.

Adult↗
PubMedDate not supplied

The learning curve in minimally invasive pituitary surgery.

BACKGROUND: Minimally invasive pituitary surgery (MIPS) is performed via an endoscopic transnasal transsphenoidal approach. This provides excellent illumination, visualization, and magnification of the operative field, in addition to avoiding complications associated with other approaches. In this study we examined the first 45 cases of MIPS to determine if a learning curve exists for this technique. METHODS: A retrospective chart review was performed of the first 45 cases of MIPS at a major academic medical center. Cases were divided into three groups of 15 patients each. Group characteristics including age, sex, and revision surgery were compared. Complication rates investigated included death, intracerebral hemorrhage, intraoperative cerebrospinal fluid leak, postoperative cerebrospinal fluid leak, use of lumbar drain, meningitis, postoperative epistaxis, ophthalmoplegia, visual impairment, and diabetes insipidus. Other factors examined included intraoperative blood loss, length of stay, and tumor histology. One way analysis of variance statistical analysis was used to determine the significance of differences between groups. RESULTS: Groups were comparable in respect to characteristics studied. Statistically significant (p < 0.05) differences in complication rates and other factors between groups were not shown. Complication rates are low. CONCLUSION: This study does not establish a learning curve for our first 45 cases of MIPS. This finding supports the concept that an otolaryngology/neurosurgery team skilled in endoscopic techniques and pituitary surgery can safely transition from open approaches to an endoscopic approach in pituitary surgery.

Adult↗
PubMed2004

Evaluation of apically extruded debris in conventional and rotary instrumentation techniques.

OBJECTIVE: The purpose of this in vitro study was to compare two common techniques, conventional and rotary instrumentation, in debris extrusion. METHODS AND MATERIALS: Two hundred mature human teeth with mature apices and less than 15 degrees of root curvature as determined by Schneider's method were selected for use. Teeth were randomly divided into four groups of 50 teeth each and prepared using step-back instrumentation and profile 4 percent Taper Series 29 rotary system at three different speeds: 1,000 rpm, 8,000 rpm and 24,000 rpm. All of the speeds were reduced by contra angle to 1/6 rpm. Extruded debris were collected on pre-weighed vials containing distilled water through the apical foramen during instrumentation. The vials were then dried in a microwave oven at 150 degrees Celsius and weighed again. The difference was recorded as "the weight of the extruded debris." Eight control vials, two for each group, were weighed and filled with distilled water, dried, and reweighed. The mean weight of extruded debris for each group was statistically analyzed. T-student, unilateral variance analysis and Pearson tests were used in this study. RESULTS: Step-back instrumentation (Group 1) produced significantly more debris than other groups. The difference in the amount of debris produced among rotary groups was not significant. CONCLUSION: Rotary technique could reduce the amount of debris extrusion.

Dental Cavity Preparation↗
PubMed2004

[Study on the compatibility of composite herbal medicines of the Zishen pill].

OBJECTIVE: To study the compatibility of composite herbal medicines of the Zishen pill. METHOD: 50% ethanol extract test solution of the different combinations of composite herbal medicines of the Zishen pill were prepared. Pharmacologic experiments, such as anti-inflammatory, carbon particle clearance of RES were carried out with the solutions, and the corresponding pharmacological data were obtained. Variance analysis, canonical correlation and stepwise regression analysis were applied to interrelate the amount of each drug and the pharmacological data. RESULT: The results confirmed that Huangbo and Zhimu were the basis, while Rougui was the corrigent, which was conformed to the theory of TCM. CONCLUSION: This study provides a significant try for studying the compatibility of composite herbal medicines.

Anemarrhena↗