Five year survival of posterior adhesive bridges. Influence of bonding systems and tooth preparation

The present study reports the final analysis of a randomized controlled clinical trial in which different designs of posterior resin-bonded bridges were evaluated for a period of at least 5 years. The operational hypothesis was that the bonding system and the preparation design used in posterior resin-bonded bridges have an influence on the survival and clinical functioning of these restorations. Survival in this study was defined at two levels: (1) 'primary' survival (survival without any debonding), and (2) 'functional' survival (survival including loss of retention on one occasion and successful rebonding of the original resin-bonded bridge without further debonding). Preparation of grooves in abutment teeth for posterior resin-bonded bridges appeared to be beneficial to their chance of survival. Resin-bonded bridges placed in the maxilla have a better prognosis than those made in the mandible. The bonding systems used in this study (etching/Clearfil F2, sand blasting/Panavia EX and silica-coating/Microfill Pontic C) appear to have no influence on the chance of failure with regards to the 'primary' survival. In rebonded posterior resin-bonded bridges, the bonding system silica coating/Microfill Pontic C was more retentive than the other systems tested.     

Relationship between memory strategies and motor symptoms in Parkinson's disease

Patients with Parkinson's disease(PD) show a serious decrease in performance on tasks which lack explicit guidelines and which necessitate the subject to develop his or her own strategy. Using the California Verbal Learning Task(CVLT) we have found evidence that this phenomenon becomes also manifest in learning and memory. The goal of the present study on PD was to investigate whether or not there is an intrinsic relationship between PD-specific deviant learning characteristics and the severity of motor symptomatology. The results show, as expected, a significant correlation between the severity of bradykinetic/hypokinetic symptoms and the serial clustering gradient of the CVLT: the more bradykinetic PD patients (n = 48) were, the more they were dependent on the externally guided serial learning strategy. The findings are discussed in the context of our hypothesis that the actual deficit in patients with PD is a deficient processing of ambiguous internal cues.     

Surgical management of severe secondary peritonitis

BACKGROUND: Despite advances in diagnosis, surgery, antimicrobial therapy and intensive care support, the mortality rate associated with severe secondary peritonitis remains unacceptably high. This article presents various surgical treatment strategies for severe secondary peritonitis, emphasizing the role of open management of the abdomen and planned relaparotomies. METHODS: Material was identified from previous review articles, references cited in original papers and a Medline search of the literature. RESULTS AND CONCLUSION: Surgical treatment of severe secondary peritonitis is highly demanding and very complex. The combination of improved surgical techniques, antimicrobial therapy and intensive care support has improved the outcome of such peritonitis following perforation or anastomotic disruption of the digestive tract, or infected necrotizing pancreatitis. However, aggressive surgical treatment strategies, such as open management of the abdomen and planned relaparotomies, may have reached their limits.     

MR contribution in surgery of epilepsy

The contribution of MR imaging in patients with drug-resistant epilepsy considered for surgical therapy is discussed. In this review we focus on: (a) focal abnormalities (mesial temporal sclerosis, focal migration disorders, hamartomatous lesions and low-grade tumours, phakomatosis and vascular malformations) associated with therapy-resistant partial epilepsy, requiring resective surgery; (b) abnormalities leading to generalized seizures that require more drastic surgical procedures, such as callosotomy and functional hemispherectomy; and (c) localisation of implanted depth-electrodes. Received: 6 April 1998; Revision received: 2 June 1998; Accepted: 3 June 1998     

Anästhesie bei geriatrischen Patienten Die Bedeutung physiologischer Variablen für die kognitive Leistungsfähigkeit geriatrischer Patienten nach Regional- oder Allgemeinanästhesie

Objective: The aim of the present study was to show the influence of the parameters of gas exchange (arterial oxygen pressure paO₂, arterial oxygen saturation SatO₂) and haemodynamics (arterial systolic and mean blood pressure RRs and MAP) on the restitution of cognitive functions in geriatric patients scheduled for elective hip arthroplasty. Methods: A total of 30 patients (70 years, ASA II) were randomized to be operated either in regional anaesthesia (n=15) or general anaesthesia (n=15). PaO₂ (by capillary blood gas analysis), RRs and MAP (by oscillometry) were measured 15 and 90 minutes after arrival in the recovery unit (t1 and t2), 24 and 72 hours postoperatively (t3 and t4), and cognitive functions were tested. Intraoperatively, throughout the day and the first night after surgery we measured satO₂ by continous pulse oximetry. We recorded MAP and RRs by oscillometry every 3 minutes during the operation and every15 minutes for the rest of that day and night. Results: The parameters of gas exchange and haemodynamics did not differ among the groups. PaO₂ was significantly reduced in both groups compared to baseline 24 hours postoperatively (t3) and remained low until 72 hours postoperatively (t4). Nearly all cognitive functions were significantly reduced in both groups compared to baseline 15 and 90 minutes after arrival in the recovery unit (t1 and t2), but recovered on the first postoperative day (t3). Both groups kept deficits in verbal memory and reading capacity up to the third postoperative day (t4). There was no correlation between the physiological parameters and the restitution of the tested cognitive functions. Conclusion: The restitution of cognitive functions during the first three postoperative days in geriatric patients scheduled for elective hip surgery does not depend on the anaesthetic technique. According to our results regional anaesthesia does not show any advantage for geriatric patients undergoing elective hip arthroplasty.     

Three-dimensional dynamic external fixation of distal radial fractures. A prospective study

This prospective study describes the experience with a new dynamic external fixator which provides three degrees of freedom, while the centre of rotation of all these movements is located in the wrist. 44 patients with unstable fractures of the distal radius were included. During the period of dynamisation, with a median flexion of 30 degrees, extension of 18 degrees, radial deviation of 0 degree and ulnar deviation of 20 degrees the range of motion needed to perform activities of daily living was approached. In spite of early mobilisation reduction was maintained. The radiological result was excellent or good in 82% of the patients and the functional result was excellent or good in 92% of the cases. Pin track infections were noted rather frequently, possibly related to the interaction between the soft tissues and the fixator pins. Based on the experiences of the study the device needs further improvement.     

A brainstem stereotactic atlas in a three-dimensional magnetic resonance imaging navigation system: first experiences with atlas-to-patient registration

OBJECT: The authors describe a computer-resident digital representation of a stereotactic atlas of the human brainstem, its semiautomated registration to sagittal fast low-angle shot three-dimensional (3-D) magnetic resonance (MR) imaging data sets in 27 healthy volunteers and 24 neurosurgical patients, and an analysis of the subsequent transforms needed to refine the initial registration. METHODS: Contour drawings from the atlas, which offer the 70th percentile of variation of anatomical structures, were interpolated into an isotropic 3-D representation. Initial atlas-to-patient registration was based on the fastigium/ventricular floor plane reference system. The quality of the fit was evaluated using superimposition of the atlas and MR images. If necessary, the atlas was tailored to the individual anatomy by using additional transforms. On average, the atlas had to be stretched by 2 to 6% in the three directions of space. Scale factors varied over a broad range from -8 to +19% and the benefit of visual interactive control of the atlas-to-patient registration was evident. Analysis of distances within the pons measured in the midsagittal MR imaging slices and the required scale factors revealed significant correlations that may be used to reduce the amount of user interaction in the coregistration substantially. In 70.6% of the cases, the atlas had to be shifted in a cranial direction along the brainstem axis (in 25.5% of cases 3-4 mm, in 45.1% of cases 1-2 mm). This was due to a more caudal position of the fastigium cerebelli on the MR images compared with the atlas. CONCLUSIONS: This observation, in conjunction with the variability of the height of the fourth ventricle in our MR imaging data (range 6.1-15.2 mm, mean 10.1 mm, standard deviation 1.8 mm) calls into question the role of the fastigium cerebelli as an anatomical landmark for localization within the brainstem.     

Tubular epithelial cells: A critical cell type in the regulation of renal inflammatory processes

Most chronic human kidney diseases are characterized by a final common pathway consisting of interstitial inflammation and ultimately leading to interstitial fibrosis. Within this process, tubular epithelial cells (TECs) play a critical role. Both in vitro and in vivo it has been demonstrated that TECs are an important source of various cytokines, chemokines, growth factors, adhesion molecules and extracellular matrix components. In the present review we will outline the capacity of TECs to produce inflammatory mediators and discuss the different mechanisms involved in the regulation of production of these mediators.