Regulation of fibroblast-induced collagen gel contraction by interleukin-1β

Fibroblasts incorporated within collagen gels induce a cell-mediated contraction of the gel to form a three-dimensional, tissue-like structure by a mechanism thought to mimic wound contraction in vivo . In this study a gel contraction model was used to investigate the ability of fibroblasts derived from adult gingiva, adult skin and fetal skin to organise a collagen matrix. In addition the effects of interleukin-1β (IL-1β) on the contraction process was also investigated. Over the concentration range 5-50 U/ml, IL-1β induced a statistically significant inhibition of gel contraction in all fibroblast cell types ( P <0.05), although fetal fibroblasts appeared least responsive and gingival fibroblasts most responsive to the inhibitory effects of this cytokine. Comparison of gel contraction by the different fibroblast strains indicated that fetal and gingival fibroblasts shared similar contraction kinetics. For the adult skin fibroblasts, three of five strains studied showed significantly diminished levels of gel contraction compared to fetal and gingival cells. This apparent difference in fibroblast phenotype may, at least in part, explain the fetal-like wound healing pattern seen in the oral mucosa.     

The effect of etching on bacterial microleakage of an adhesive composite restoration.

OBJECTIVES: The incidence of bacterial microleakage, pulp inflammation and necrosis associated with dentine etching treatments prior to restoration are not known. Consequently, to resolve some of the controversy surrounding the effects and importance of vital dentine etching, the authors investigated these factors. METHODS: 110 standardised class V cavities were cut into buccal dentine, without exposing the pulp of teeth scheduled for extraction for orthodontic reasons. Cavities were either left unetched, or etched with the non-equivalent treatments of phosphoric acid gel for 60s or Ethylenediaminetetraacetic acid (EDTA) for 30s, prior to placement of composite resin. Teeth were collected and pulp responses were evaluated according to ISO guidelines, using pathohistomorphometric analysis and ANOVA statistics. RESULTS: Etching was found to be correlated to bacterial microleakage (p=0.0001) and tertiary dentine formation (p=0.0023). Bacterial microleakage was correlated to inflammatory activity (p=0.0001). The frequency of bacterial microleakage was: no etching (65%), EDTA (51%) and phosphoric acid (PA) (20%). SIGNIFICANCE: Vital dentine etching treatment is of extreme importance for the placement of RC to minimise bacterial microleakage. PA etching proved to be more effective at preventing bacterial microleakage than non-etching, and etching with EDTA.     

Operations on the saccus endolymphaticus and vestibular nerve: have they fulfilled their promise?

The rationale for operations on the saccus and vestibular nerve in patients incapacitated by Meniere's disease as a replacement for total labyrinthectomy, has been the expectancy that less radical procedures will protect these patients from total auditory incapacity. Aware of postoperative hearing losses in some patients after 3 years, we have studied the results in 21 Shambaugh saccus decompression (SD) and 29 middle fossa vestibular nerve section (VNS) operations, in order to assess the claims made for these procedures. We found that while control of vertigo was similar to that reported elsewhere, worse hearing (AAOO criteria) developed in many cases. With SD this increased from 14% at 1 year to 58% at 10 years, and with VNS it increased from 17% at 1 year to 48% at 10 years, when the worse preoperative audiogram was used. Only 17% of SD and 11% VNS ears with serviceable best preoperative hearing had retained this at 10 years. Nineteen percent developed audiometric evidence of contralateral disease during the first 10 postoperative years. It is concluded that although, regrettably, neither of these surgical therapies appears to have the capability of preventing the progress of hearing loss, the reality of bilateral disease justifies the continued use of SD or VNS by adequately trained surgeons.     

Gesture development: a review for clinical and research practices.

The aim of this article is to provide clinicians and researchers a comprehensive overview of the development and functions of gesture in childhood and in select populations with developmental language impairments. Of significance is the growing body of evidence that gesture enhances, not hinders, language development. In both normal and impaired populations, gesture and language development parallel each other and share underlying symbolic abilities. Gesture serves several functions, including those of communication, compensation, and transition to spoken language. In clinical practice, gesture may play a valuable role in diagnosis, prognosis, goal selection, and intervention for children with language impairments. Where available, supporting evidence is presented. Needs for additional research on gesture are also highlighted.     

A path-analytical approach to differentiate between direct and indirect drug effects on negative symptoms in schizophrenic patients

The hypothesis that differences in drug effects of risperidone and haloperidol on negative symptoms in schizophrenia are secondary to effects on positive, extrapyramidal, and depressive symptoms was investigated by means of an analysis of the data from the USA-Canada risperidone double-blind randomized clinical trial of 523 chronic schizophrenic patients. Regression analyses in the total sample and within treatment groups confirmed a strong relationship between changes in negative symptoms and the other variables studied (R²=0.50–0.51,p<0.001). Only depressive symptoms did not contribute significantly to these results (p>0.10). Path analysis showed that the greater mean change (p<0.05) of negative symptoms with risperidone compared to haloperidol could not be fully explained by correlations with favourable effects on positive and extrapyramidal symptoms. The relationship between shift in extrapyramidal symptoms and shift in negative symptoms failed to reach statistical significance; however, there was a clear tendency in the expected direction in both treatment groups.     

Neuropharmacology and Drug Interactions in Clinical Practice

Summary: Absorption, distribution, and clearance are key pharmacokinetic principles. These parameters can be highly variable among patients and among compounds, and are factors that must be considered in the wide variability in response to medications. Current antiepileptic drugs (AEDs) present many challenges in their administration. However, understanding and utilizing pharmacokinetic principles can assist the clinician in the appropriate optimization of AEds.     

Prevalence of hypocitraturia and hypopyrophosphaturia in recurrent calcium stone formers: as isolated defects or associated with other metabolic abnormalities

Several underlying metabolic abnormalities may be present in patients with recurrent calcium calculus disease (RCCD). The aim of this study was to determine the prevalence of deficiencies of 2 well-known potent inhibitors of crystal formation and growth, citrate and pyrophosphate, in the various metabolic subgroups and as single defects. In 107 patients with RCCD, urinary citrate was significantly decreased in all metabolic subgroups with 49% of patients having hypocitraturia (2.53 +/- 1.19 mmol/24 h) versus controls (3.44 +/- 0.96 mmol/24 h; p less than 0.001). Reduced pyrophosphate:creatinine ratios were present in all the patient subgroups, and 48% of all patients had reduced ratios (1.68 +/- 1.68 vs. 3.10 +/- 2.66 in controls; p less than 0.01). There was no correlation between citrate and pyrophosphate concentration. Isolated hypocitraturia was found in 11.2%, reduced pyrophosphate:creatinine ratios as the single defect in 11.2% and a combination of both in 12.1% of patients. Thus inhibitor defects play an important role in patients with RCCD and frequently occur as isolated biochemical defects.     

Bacteraemia in diabetics

During a period of 22 months one or more episodes of bacteraemia were detected in 168 patients in hospital. Of these, 29% also had diabetes compared with 10% of the total number of patients admitted to hospital during this time (P less than 0.001). The diabetics with bacteraemia were elderly and diabetes had usually been present for many years. Most of them were not receiving insulin at the time bacteraemia was diagnosed. Escherichia coli was the commonest pathogen (33%) in the diabetics, the main source of infection being the urinary tract. This finding may be due to diabetic autonomic neuropathy, which leads to a poorly emptying, chronically infected bladder. Urinary tract infections with bacteraemia in elderly diabetics are often accompanied by vague non-specific symptoms and poor diabetic control. Fever is infrequent. Prompt antibiotic therapy and insulin injections to control the diabetes usually cure these serious infections.