Morphological analysis of the acute effects of overdistension on the extracellular matrix of the rat urinary bladder wall.

PURPOSE: To investigate the morphological effects of acute overdistension in the structure of the extracellular matrix of the bladder wall in rats. MATERIALS AND METHODS: The bladders of a group of 6 male Wistar rats were transurethrally overdistended for 3 hours. Another identical group (the control group) was only submitted to a sham operation. Specimens from the bladder dome were analyzed with light microscopy (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). RESULTS: LM--The control group bladders had a 4 to 5 layer urothelium, a lamina propria, and a smooth muscle layer with longitudinal and transversal fibers. The overdistended bladders presented an intense interstitial infiltrate in the lamina propria, and a less intense infiltrate among the smooth muscle fibers. TEM--The cells of the overdistended bladders had a significant amount of vacuoles, unlike the control bladders, where such vacuoles were scarce or absent. SEM--A delicate three-dimensional mesh of collagen fibrils was observed in the lamina propria of the bladder walls from the control group. Whilst for the control group this mesh consisted of distinct geometric structures, with mostly circular cellular spaces surrounded by the fibrils, the overdistended group showed evidence of distortion of the mesh, with flattened and elongated cellular spaces. CONCLUSIONS: Acute bladder overdistension induces structural modifications, altering the arrangement and interaction of collagen fibrils, as well as incipient tissue damage as edema in the lamina propria and smooth muscle layers.     

Stability of skeletal Class III malocclusion after combined maxillary and mandibular procedures: titanium versus resorbable plates and screws for maxillary fixation.

PURPOSE: The aim of this study was to evaluate skeletal stability after double jaw surgery for correction of skeletal Class III malocclusion to assess if there were any differences between resorbable plate and screws and titanium rigid fixation of the maxilla. PATIENTS AND METHODS: Twenty-two Class III patients had bilateral sagittal split osteotomy for mandibular setback stabilized with rigid internal fixation. Low level Le Fort I osteotomy for maxillary advancement was stabilized with conventional titanium plate and screws in 12 patients (group 1) and with resorbable plate and screws in 10 patients (group 2). Lateral cephalograms were taken before surgery, immediately postoperatively, 8 weeks after surgery, and 1 year postoperatively. RESULTS: Before surgery both groups were balanced with respect to linear and angular measurements of craniofacial morphology. One year after surgery, maxillary stability was excellent in both groups. In group 1 no significant correlations were found between maxillary advancement and relapse. In group 2, significant correlations were found between maxillary advancement and relapse at A point and posterior nasal spine. No significant differences in postoperative skeletal and dental stability between groups were observed. CONCLUSION: Surgical correction of Class III malocclusion after combined maxillary and mandibular procedures appears to be a fairly stable procedure for maxillary advancements up to 5 mm independently from the type of fixation used to stabilize the maxilla. Resorbable devices should be used with caution for bony movements of greater magnitude until their usefulness is evaluated in studies with large maxillary advancements.     

Gastro-oesophageal and bile reflux--simultaneous quantitative assessment with gastric and gallbladder emptying evaluation: clinical applicability of a new computerized gammagraphic method.

The aim of this study was to develop a new computerized gammagraphic method to evaluate gastrooesophageal (GER), bileo-oesophageal (BER) and bileogastric reflux (BGR) simultaneously with gastric and gallbladder emptying: a long duration (60 min) and a dual energy detection (113Inm-sulphur colloid and 99Tcm-HIDA) test of the different refluxes during slow gastric emptying of an enteric feeding liquid meal. Forty patients with oesophagitis and 18 normal volunteers were evaluated. Good reproducibility of all the quantified parameters was found with r Spearman between 0.75 (P < 0.05) and 1.0 (P < 0.001). Patients with oesophagitis have a tendency for slower gastric emptying patterns (gastric emptying T1/2, GT1/2 P < 0.05). The calculated specificity for gallbladder emptying parameters was 77.8% for the gallbladder T1/2 BT1/2) and 94.4% for gallbladder residue at 60 min (BR60). The calculated accuracy for the GER index was 90%. The predictability for positive values was 95%, owing to a 90% sensitivity and 89% specificity. The predictability for negative values was 80%. The mean GER index in oesophagitis was greater than in controls (P < 0.001). The calculated specificity for BGR was 94.4% and reflux was detected in 12 out of 40 patients. The calculated specificity for BER was 83.3% for a '+' index and 94.4% for a '++' BER index. In 14 patients a positive BER index has been determined ('+' in three and '++' in 11 cases).(ABSTRACT TRUNCATED AT 250 WORDS)     

The brain as a target for adrenocortical steroids: cognitive implications.

It is well established that a reciprocal control exists between the brain and glucocorticoid hormones. The brain regulates adrenocortical function via hypothalamic corticotrophin releasing hormone-41 (CRH-41), glucocorticoids act at specific receptors in the hippocampus, thus promoting negative feedback mechanisms. Because the hippocampus is a major site for memory processes, a role for excessive/long-lasting plasma glucocorticoid levels has been suggested in conditions of mental impairment. Major depression, Cushing's disease, and dementia of the Alzheimer type are disorders which share hyperactivity of the hypothalamo-pituitary-adrenal axis, as well as symptoms of cognitive decline. Although the mechanisms leading to hypercortisolemia appear to be different in each case, the neuropsychological features of these three disorders accord with the hypothesis of glucocorticoid-associated brain damage. It therefore is important to find pharmacological strategies that will avert or reduce these potential consequences on brain function.     

Skin cancers and precancerous lesions in Parkinson's disease patients.

Our objective was to evaluate the frequency of neoplastic and preneoplastic skin lesions in Parkinson's disease (PD) patients when compared with an aged-matched population. We performed a cross-sectional survey in PD patients and in an age-matched control group. Patients and controls were examined by a movement disorder specialist and a dermatologist. 150 PD patients and 146 controls were included. Thirty-five PD patients (23.3%) presented skin lesions that could be classified as neoplastic or preneoplastic vs. 20 subjects in the control group (13.7%) (OR 95%, CI 1.92 [1.05, 3.51]). However, this difference lost statistical significance when adjusted for gender (recruitment of controls was matched just for age with an over representation of males in the PD group). Twenty-nine PD patients (19%) presented actinic keratosis and basal cell carcinoma was diagnosed in 4 patients (3%). Although nonconclusive, our results are in agreement with previous studies suggesting an increased risk of skin cancer in PD patients. The frequency of actinic keratosis in PD patients and the associated risk to develop melanoma recommends its screening in future epidemiological studies.     

Levetiracetam monotherapy in Alzheimer patients with late-onset seizures: a prospective observational study

Levetiracetam (LEV) monotherapy was investigated in 25 patients with advanced Alzheimer's disease (AD) and new-onset epileptic seizures in a prospective open-label study. At a daily dose of 1000–1500 mg, 72% were seizure-free for at least one year; 16% discontinued for untolerability; 8% were unresponsive; 4% were lost to follow-up. These results suggest the need for controlled studies to confirm if LEV can be a first-choice drug in AD.     

Polyethylene wear in primary knee arthroplasty

Abstract Polyethylene (PE) wear is a focal issue in joint replacement, so it is essential to understand how it takes place in vivo. PE wear is a multifactorial process with a complex interaction of variables related to the materials used, the mechanical conditions, operative procedures for implantation, activity of the patient and use of prosthesis. We retrieved 65 PE inserts with the respective femoral and tibial components (50 inserts of total knee prostheses and 15 monocompartmental prostheses) from first revision surgeries. The average age of the patients was 68.3 years; the average time to revision was 41.5 months. Macroscopic observation considered the grade, topography and type of wear. Degradation was also studied with scanning electron microscopy. No direct relationship was found between the level of wear and the survival of total or monocompartmental knee prostheses. The duration of 11 (22%) total prosthetic inserts with grade 2 wear was 42.6 months vs. 51.5 months of 17 (34%) total inserts with grade 1 wear. However, study of the relationship between wear grade and wear topography in total inserts suggested that there was a significant connection. In fact, the 22 (44%) prostheses with central and symmetrical wear never showed wear greater than grade 1. Instead, of the remaining 28 prostheses (56%) without central and symmetric wear, only 3 had grade 0 wear. Finally, considering the relationship between wear grade and type of wear, all 18 inserts (27.7%) with grade 2 or 3 wear had 100% delamination. In conclusion, this study suggests that the correct positioning of the prosthetic components, besides its quality, is an important cause of polyethylene wear.     

LAPAROSCOPIC CHOLECYSTECTOMY: THE EXPERIENCE OF A COMMUNITY HOSPITAL

Background: The practice of laparoscopic cholecystectomy in a community hospital is presented. The morbidity of the procedure is analysed and recommendations for improvement are made. Laparoscopic cholecystectomy was introduced into this 200 bed community hospital in October 1990. All five general surgeons accredited to the hospital agreed to participate in a quality assurance programme to determine the incidence of complications and to make recommendations for improvement. Methods: The records of all 534 patients having laparoscopic cholecystectomy between October 1990 and September 1993 were reviewed, and all complications recorded. Results: Of the 534 cases reviewed in the study 470 were considered uncomplicated and 64 patients experienced a total of 85 postoperative complications. The death of one patient was caused by a pulmonary embolus and another patient experienced a myocardial infarction. Twenty patients has postoperative atelectasis or pneumonia and urinary infection or retention occurred in seven. Complications of laparoscopic cholecystectomy requiring a conversion to open cholecystectomy occurred in eight patients, biliary complications occurred in 18 and 11 patients required re-operation. Conclusions: Three areas of concern were identified. They were the incidence of major biliary injury (0.37% of all cases) and its management, the role of cholangiography. and the incidence and prophylaxis of deep venous thrombosis and pulmonary embolism. Recommendations for improvement in these areas were made.     

Permeability of pure lipid bilayers to melatonin

Abstract: Melatonin, the chief hormone of the pineal gland, has been reported to interact with a variety of different cells. This ubiquitously acting hormone has been found to interact with protein receptors both at the cell membrane and in the nucleus. Moreover, melatonin was recently shown to be a very potent hydroxyl radical scavenger. The present work focuses on the interaction of melatonin with pure lipid bilayers. It is shown that melatonin can cross multilamellar lipid vesicles, which are used here as model systems for the lipid phase of biological membranes. Thus, the data prove that melatonin can easily pass through the cell membrane and bath every part of the cell, as previously suggested in the literature. Melatonin lipid association constant was calculated based on the change of the hormone fluorescence intensity due to its penetration into the hydrophobic lipid phase. Though melatonin was recently shown to be highly soluble in aqueous media, its lipid association constant is rather high, indicating that the biological action of the hormone is likely to be at the membrane level, either via its interaction with membrane receptors, and/or as a lipoperoxidation radical scavenger.