Treatment time analysis for extensive amalgam restorations

The treatment times for the fabrication of Extensive Amalgam Restorations (EAR) as recorded in a longitudinal clinical trial at the Dental School in Nijmegen were analyzed. 269 EAR's with different retention methods were made on molars by three operators. A mean total treatment time of 60 min was found. The factor operator had a significant influence on all treatment phases resulting in a 26% difference in total treatment time between operators. Also significant influences were found in some treatment phases for the factor retention, side location of the tooth and extension of the restoration. The results of this study with regard to treatment times must be considered from the perspective of the quality of the care provided.     

Response of lower esophageal contractility to changing concentrations of halothane or isoflurane: A multicenter study

A multiple-center study was performed to determine the relationship between lower esophageal contractility, clinical signs, and anesthetic concentration as expressed by minimum alveolar concentration (MAC). One hundred four American Society of Anesthesiologists Class I through III patients were exposed to isoflurane (with and without nitrous oxide) or halothane in concentrations of 0.5, 1.0, and 1.5 MAC. Heart rate and systolic blood pressure were continuously monitored. Both the amplitude and frequency of spontaneous and provoked lower esophageal contractions were measured in situ by using a 24-F probe equipped with provoking and measuring balloons. Combined results demonstrated statistically significant correlations (P<0.001) between lower esophageal contractility and MAC. Spontaneous lower esophageal contractions decreased from 1.10±0.12 (SEM) contractions per minute (0.5 MAC) to 0.42±0.05 (1 MAC) to 0.18±0.05 (1.5 MAC). Provoked lower esophageal contractility values decreased from 45±4 mm Hg (0.5 MAC) to 29±3 (1 MAC) to 19±2 (1.5 MAC). Heart rate changes did not correlate with MAC, and systolic blood pressure correlated in only one of three centers. Intracenter and intercenter analyses failed to demonstrate a significant relationship between lower esophageal contractility and heart rate or systolic blood pressure. No intracenter differences in either amplitude or frequency of lower esophageal contractions were observed, despite differences in volatile agents, induction techniques and agents, patient populations, and duration of anesthesia. Our studies indicate that lower esophageal contractility may be an indicator of anesthetic depth as reflected by MAC, but further studies are needed to quantify the effects of surgical stimulus, intravenous anesthetics, vasodilators, anticholinergics, calcium channel blockers, beta-adrenergic agonists, and the presence of a nasogastric tube.     

一种切除部分齿状线和肛管全层的超低位保肛手术

目的介绍一种切除部分齿状线和肛管全层的直肠恶性肿瘤的超低位保肛手术。方法对8例瘤灶下缘距离齿状线小于或等于2cm的直肠超低位恶性肿瘤进行术前评估,对6例患者首先进行术前放疗化疗使肿瘤明显缩小。手术在完成全直肠系膜和(或)盆腔淋巴清扫的基础上,向下切断骶骨直肠韧带,达到肛管直肠肌环上缘,相当于齿状线(直肠肛管交界处)水平。如果癌下缘远侧正常肠管长度仍小于2cm,可沿外括约肌环和肠壁之间再向下分离1～2cm。肛门手术组充分显露肿瘤部位,在直肠癌向下侵犯最低侧所在的1/2象限,于癌灶下缘2cm处垂直于肛管长轴切开肛管全层,然后沿外括约肌环向上游离,切除癌侧部分齿状线,与腹部手术组会师,在没有癌灶或癌侵犯较高的一侧,则沿齿状线上缘切断直肠。游离横结肠脾区并在降结肠远切端作长5cm的“J”形结肠储袋,将结肠储袋向下脱出至肛管断端,与癌灶侧肛管、癌灶对侧的齿状线用3-0可吸收线间断手工缝合。结果在遵守根治原则的基础上,采用本方法成功地为8例直肠超低位恶性肿瘤患者进行了保肛手术,部分切除齿状线的患者术后肛门功能与Dixon手术患者近似。结论在直肠全系膜切除和盆腔淋巴清扫的基础上,尤其在术前放疗化疗的基础上,切除部分齿状线和肛管全层的保留肛门的手术方法可达到根治要求并保留功能     

Threshold for occluded formaldehyde patch test in formaldehyde-sensitive patients

Our purpose was to investigate the eliciting threshold concentration of formaldehyde in formaldehyde-sensitive individuals in the occluded and non-occluded patch teat and to evaluate the relationship in repeated open application test (ROAT) with a product containing a formaldehyde releaser. 20 formaldehyde-sensitive patients and a control group of 20 healthy volunteer were included in the study. Occluded and non-occluded patch tests with formaldehyde solutions form 25 to 10,000 ppm. and ROAT for I week with a leave-on cosmetic product containing on average 300 ppm formaldehyde. Were carried out simultaneously on each subject. In the occluded patch test. 1/2 of the 20 patients only reacted to 10,000 ppm formaldehyde. 9 reacted to 5,000 ppm. 3 reacted to 1.000 ppm. 2 reacted to 500 ppm and I reacted to 25 ppm. No definite positive reactions were observed in the non-occluded patch test or in the ROAT No positive reactions were observed in the control group to any of the test procedures. We concluded that the threshold concentration for occluded patch test to formaldehyde in formaldehyde-sensitive patients was 250 ppm. The threshold in occluded patch test corresponded to the degree of sensitivity Definite positive reactions in the ROAT were not seen, either indicating that they are unlikely to happen with the type of product used or that the exposure time was too short.     

Chemical synovectomy vs. radioactive synovectomy for the treatment of chronic haemophilic synovitis: a prospective short-term study

Between January 1992 and December 1994, a prospective study was performed in two centres comparing chemical synovectomy using repeated weekly injections (range, 1–17) of Rifampicin (Group R) vs. radioactive synovectomy using 1–2 injections of Yttrium-90 (Group Y). The study was performed on 38 joints in a total of 35 haemophilic patients suffering from chronic haemophilic synovitis unresponsive to 3 months of conservative treatment (substitution therapy with the deficient coagulation factor plus a rehabilitation protocol). Group R included 18 patients with an average age of 9 years, with an average follow-up time of 25 months. In Group R, 19 joints were treated: nine knees, four elbows and six ankles. Group Y included 17 patients with an average age of 18 years, with an average follow-up time of 23 months. In Group Y, 19 joints were treated: 14 knees, two elbows and three ankles. The joints were evaluated according to the frequency of bleeding episodes and the Pettersson radiographic score. On the basis of the radiographic scale at the time of the synoviortheses, the joints were categorized as stage I (0 points), stage II (1–2 points), stage III (3–7 points), stage IV (8–10 points) and stage V (11–13 points). The overall results showed that in Group R, bleeding decreased in 12 joints, remained the same in six and worsened in one. In Group Y, bleeding decreased in 11 joints, remained the same in seven and worsened in one. In both Groups, bleeding was controlled best if joints were in stages I and II. In stages III, IV and V, synoviorthesis should not be carried out in haemophilia because it is not effective. Use of radioactive substances in persons under the age of 9 years has been discouraged in the past and therefore only Rifampicin was used in this age group. However, in patients over 9 years of age, this study showed similar decrease of bleeding in both treatment groups. Taking into account the advantages and disadvantages of both agents, we suggest the use of Rifampicin in elbows and ankles but prefer Yttrium-90 for the knees.     

Pathophysiology of idiopathic dystonia: findings from genetic animal models

Dystonia is a common movement disorder which is thought to represent a disease of the basal ganglia. However, the pathogenesis of the idiopathic dystonias, i.e. the neuroanatomic and neurochemical basis, is still a mystery. Research in dystonia is complicated by the existence of various phenotypic and genotypic subtypes of idiopathic dystonia, probably related to heterogeneous dysfunctions.In neurological diseases in which no obvious neuronal degeneration can be found, such as in idiopathic dystonia, the identification of a primary defect is difficult, because of the large number of chemically distinct, but functionally interrelated, neurotransmitter systems in the brain.The variable response to pharmacological agents in patients with idiopathic dystonia supports the notion that the underlying biochemical dysfunctions vary in the subtypes of idiopathic dystonia. Hence, in basic research it is important to clearly define the involved type of dystonia.Animal models of dystonias were described as limited. However, over the last years, there has been considerable progress in the evaluation of animal models for different types of dystonia.Apart from animal models of symptomatic dystonia, genetic animal models with inherited dystonia which occurs in the absence of pathomorphological alterations in brain and spinal cord are described.This review will focus mainly on genetic animal models of different idiopathic dystonias and pathophysiological findings. In particular, in the case of the mutant dystonic (dt) rat, a model of generalized dystonia, and in the case of the genetically dystonic hamster (dt^sz), a model of paroxysmal dystonic choreoathetosis has been used, as these show great promise in contributing to the identification of underlying mechanisms in idiopathic dystonias, although even a proper animal model will probably never be equivalent to a human disease.Several pathophysiological findings from animal models are in line with clinical observations in dystonic patients, indicating abnormalities not only in the basal ganglia and thalamic nuclei, but also in the cerebellum and brainstem. Through clinical studies and neurochemical data several similarities were found in the genetic animal models, although the current data indicates different defects in dystonic animals which is consistent with the notion that dystonia is a heterogenous disorder.Different supraspinal dysfunctions appear to lead to manifestation of dystonic movements and postures. In addition to increasing our understanding of the pathophysiology of idiopathic dystonia, animal models may help to improve therapeutic strategies for this movement disorder.     

Interviewing skills: self-evaluation by medical students

In an independent learning project, 52 third-year medical students carried out a structured self-assessment of two videotaped psycho-social interviews they had conducted with volunteer clients 1 year earlier, as part of a previous course. The interviews had been conducted in small tutorials with feedback from their clients, fellow students and tutors, facilitated by videotape playback. During the sequence of 16 tutorials each student had carried out an early and a late interview and had observed and participated in the discussion of the interviews of 14 peers. Students were asked to tally the frequencies of various interview behaviours, to evaluate the quality of their behaviours, and to establish priorities for future learning. The videotapes were also reliably rated by an independent observer. Students' overall self-assessments correlated 0.46 with those of the independent observer. This correlation was higher than is typically reported in studies of the validity of self-assessment. In absolute terms, the students' mean rating of interviewing performance was 3.2 (adequate plus) which was significantly lower than the observer's mean of 3.6 (adequate to good). Results are discussed in terms of Gordon's (1992) two recommendations for improving the validity of self-assessments and two further suggestions, for paired comparisons and low-threat learning environments, are added.     

显微外科技术治疗周围神经陈旧性损伤

目的探讨应用显微外科技术治疗需再次手术的周围神经损伤的方法和疗效。方法对33例周围神经损伤第一次手术效果差的患者,应用显微外科技术进行再次手术治疗。结果本组获得随访30例,共41条神经,随访时间为9个月～6年,平均为27个月,优良率为73.2%。结论对周围神经损伤初次手术效果差的患者,应尽早再次手术探查,应用显微外科技术,选择合适的手术方式,可取得较满意的手术疗效。     

支撑捆扎法在腹腔镜下全直肠系膜切除超低位结肠-直肠/肛管吻合术中的应用

目的 介绍支撑捆扎法在腹腔镜下对低位直肠癌进行全直肠系膜切除(TME)超低位结肠．直肠／肛管吻合的手术方法。方法 应用超声刀在腹腔镜下对11例低位直肠癌患实施TME原则的根治性切除，用支撑捆扎法完成超低位结肠．直肠／肛管吻合术。结果 11例患术中直肠系膜切除完整。超低位结肠-直肠／肛管吻合成功，吻合时间15—30min；吻合口距齿状线小于2cm8例。结肠与齿状线处肛管吻合的3例。术后恢复顺利。肛门括约肌功能、排尿功能良好，未发生吻合口瘘与吻合口狭窄。结论 腹腔镜结合支撑捆扎法可以对低位直肠癌行TME切除后进行超低位结肠-直肠／肛管吻合术。