The effects of a 0.12% chlorhexidine-digluconate-containing mouthrinse versus a placebo on plaque and gingival inflammation over a 3-month period

Abstract Several previous studies have evaluated the effects of 0.12% chlorhexidine digluconate (ChD) mouthrinses on plaque and gingival inflammation. However, previously, none have been based in general dental practices. The aim of this study was to evaluate the potential to conduct controlled periodontal clinical trials in co-operation with general dental practitioners (gdps). The project took place in 5 general dental practices in the South of England. 121 healthy subjects (24 at 4 sites and 25 at the 5th). aged 18-65 years, mean 35 ± 12) years participated in a double-blind, randomised study during which they received full mouth assessments for plaque and gingival bleeding at baseline, 6 and 12 weeks. 60 subjects were randomly asigned to use the 0.12% ChD mouth wash and 6i the placebo. The assessments were carried out by 5 gpds, who had previously achieved inter-examiner κ scores of 0.78–0.85 (mean 0.81) for the plaque index (PlI), and of 0.73–0.94 (mean 0.87) for a modified gingival index (mGI), and who maintained κ scores of 0.51–0.90 for PII and of 0.73–1.00 for mGI during the 12 months required to complete the study. 98 subjects (48 ChD and 50 placebo) completed the study. Even though the baseline levels of plaque and gingivitis were low, by week 12, mean whole mouth piaque score of the ChD mouthwash users had fallen from 1.33 at baseline to 0.96 and was significantly lower (p < 0.001) than for the placebo users, 1.31 at baseline to 1.13. Whole-mouth gingival bleeding score fell from 0.56 to 0.42 in the ChD mouthwash group but was unchanged (0.54–0.55) in the placebo group. A subsidiary data analysis which considered the effects at sites indicated that within these overall differences, the ChD users experienced almost 2× the reduction from plaque score 2 at baseline at proximal molar sites over a 12-week period (50.6% ChD versus 27.6% placebo). It was concluded that 0.12% ChD mouthwash reduced plaque accumulation fay 28% and gingival inflammation by 25% over a 12–week period, that it is feasible for a group of gdps to maintain high levels of inter–examiner consistency in the use of PlI and mGI, that it is also feasible to carry out such a multicentre study in general dental practice, and that the use of mean mouth scores per subject to analyse the effects of mouthrinses may well mask variations in response throughout the mouth.     

A study of mixing conditions during nitric oxide administration using simultaneous fast response chemiluminescence and capnography

We have evaluated the mixing properties of nitric oxide in inspired gases for five different administration techniques. Nitric oxide and carbon dioxide were delivered to the ventilator system before the ventilator or after the ventilator as a continuous flow, either directly into the inspiratory limb or into a mixing chamber positioned in the inspiratory limb. Both gases were delivered as above but synchronized with inspiration. Mixing conditions were evaluated using fast response chemiluminescence for nitric oxide and capnography for carbon dioxide analysis. Administration of nitric oxide and carbon dioxide directly into the inspiratory limb as a continuous flow or with a magnetic valve-controlled synchronized flow resulted in peak concentrations of 236% and 220%, respectively, of expected values. The use of a mixing chamber reduced these values to 104% and 102%, respectively. Administration of nitric oxide as a continuous flow into the tubing of an intermittent flow ventilator resulted in highly fluctuating inspiratory peak concentrations, which could be avoided with a mixing chamber.      

Content and contractile effect of arginine vasopressin in rat urinary bladder

The contractile response of normal male rat urinary bladders to exogenous arginine vasopressin (AVP) and the AVP content of normal and denervated bladders were investigated. In isolated detrusor strips, the maximal response to AVP was about 12% of the contraction elicited by KCl (124 mM), and the EC50 value was 1.03 +/- 0.13 x 10(-8) M. The response to transmural nerve stimulation was not affected by the presence of AVP. Addition of an AVP receptor antagonist strongly reduced the response to exogenous AVP, but did not affect contractions in response to nerve stimulation. In normal bladders, the concentration of immunoreactive (ir) AVP was 29 +/- 6.0 x 10(-15) mol/g. Three days after denervation the bladders had increased 2.4-fold in weight. At this time, the concentration of irAVP was not different from the control value, but the total content had increased significantly. Characterization of bladder irAVP by reverse-phase HPLC revealed that 66.5% of the total immunoreactivity eluted in the position of synthetic AVP. The results suggest a non-neuronal localization of bladder irAVP.     

Enhanced Intestinal Absorption of Oxytocin Peptide Analogues in the Absence of Pancreatic Juice in Pigs

Purpose. The present investigation was done to study the intestinal absorption of three oxytocin peptide analogues and to elucidate the role of pancreatic juice on their absorption. Methods. In conscious chronically catheterized pigs (6–8 weeks of age) plasma concentration of the peptides, [Mpa¹, D-Tyr(Ethyl)², Thr⁴, Orn⁸]-oxytocin (F314), [Mpa¹, D-Tyr(Ethyl)², Val⁴, D-Arg⁸]-oxytocin (CAT), and [Mpa¹, D-Tyr(Ethyl)², Thr⁴, Orn⁸, desGly⁹, carba⁶]-oxytocin (F327) after intraduodenal administration, during presence or diversion of the pancreatic juice via a pancreatic duct catheter, were determined by radioimmunoassay. The stability of the peptides to degradation was determined in vitro by incubation with activated pancreatic juice, chymotrypsin or trypsin, followed by reversed phase HPLC analyses. Results. All peptides were absorbed with a bioavailability of about 0.5% in the presence of pancreatic juice, but increased to 1.0%, 2.1%, and 13.5% for F314, CAT, and F327, respectively, when the pancreatic juice was diverted from the intestine. After incubation with pancreatic juice 95% of F314, 98% of F327, and 100% of CAT was found intact. When incubated with trypsin CAT remained intact while F314 and F327 were degraded by 54% and 46%, respectively. Incubation with purified chymotrypsin did not degrade the test peptides. Conclusions. The results indicate that the increased absorption of peptides observed under conditions of diverted pancreatic juice cannot only be explained by the absence of pancreatic enzymes, but also by changed absorptive properties in the gastrointestinal tract.     

Diffuse intermyocardiocytic fibrosis in uraemic patients

At post-mortem we examined heart tissue of (i) 31 patients with uraemia not on dialysis, (ii) 42 patients on haemodialysis for less than 6 months, (iii) 60 patients on haemodialysis for more than 6 months, (iv) 16 patients after renal transplantation, and (v) 11 patients on CAPD. Patients with stenosing coronary lesions were excluded. Diffuse non-coronary intermyocardiocytic fibrosis, assessed by a score system in trichrome-stained sections, was found in 91% of chronically uraemic patients, but not in non-hypertensive, non-diabetic controls. The lesion was present even in non-dialysed uraemic patients; in dialysed patients its severity was related to the duration of dialysis; it was demonstrable even years after renal transplantation. On electron-microscopy, collagen fibres were seen, while beta 2-M amyloid was consistently absent. Logistic regression analysis showed that uraemia was a determinant of intermyocardiocytic fibrosis independent of hypertension, diabetes mellitus, anaemia, heart weight, and presence or absence of dialysis procedure.     

Synergistic action of immunostimulatory DNA and fcgamma receptor IIB-crosslinking on B-cell phenotype and function

CpG DNA functions via the toll-like receptor-9 (TLR-9) receptor, inducing B cell proliferation and promoting immunoglobulin production. B cell responses to CpG DNA-containing immune complexes could be important in chronic autoimmunity and immune responses to bacterial components. Therefore, we investigated the potential synergy of CpG DNA-stimulation with FcgammaR clustering (CFR) on splenic B cell activity. CFR-induced splenocyte proliferation was significantly increased compared to treatment with CpG DNA alone. While the levels of interleukin-10 (IL-10) were increased in CpG DNA-treated splenocyte cultures, particularly following FcgammaRII/III-clustering, CFR treatment reduced IL-6 levels. B-cell maturation in culture was enhanced by CFR. Indeed, the frequency of IgG expressing cells after stimulation with CpG DNA was increased and was even higher after CFR stimulation. Furthermore, the frequency of plasma cell precursors was markedly increased by stimulation with CFR. Late splenic B cell subsets, transitional type 2 (T2) and mature (M) B cells, responded strongly to CpG DNA with proliferation and the response was enhanced by FcgammaR-clustering. Immature transitional type 1 (T1) B cells showed distinctly lower proliferative response to CpG DNA and very small effects of FcgammaR-clustering, despite similar expression of Fcgamma-receptors by all B cell subsets. In conclusion, these data show synergistic impact of CpG DNA and simultaneous FcgammaR-clustering on B cell proliferation and differentiation.