Dentists' variability in restorative decisions, microscopic and radiographic caries depth

Restorative and dental caries depth decisions were recorded for 5168 un restored approximal tooth surfaces by 17 dentists who worked in the school dental clinics of the North York (Ontario) Public Health Department. Each dentist examined 15 pairs of experimental bitewing radiographs for which true caries depth had previously been determined by microscopy of the sectioned teeth following production of the radiographs. The dentists independently recorded their restorative decisions and radiographic caries depth perceptions. The relationship between the variation in the dentists' restorative decisions and their perceptions of caries depth based on a re-reading of the bitewings on the one hand, and true caries depth on the other was also examined. The percentages of total variability in each dentist's restorative decisions attributable to radiographic and to microscopic caries depth were estimated using regression analyses. Large variations were found among the 17 dentists' distributions of overall restorative and depth decisions. The relationship between microscopic caries depth and the dentists' restorative decisions was, understandably, less strong than that of the dentists radiographic perceptions of caries depth and restorative decisions. Relative to true caries depth, high numbers of false positive and false negative restorative decisions were made. Overall, 50% of the variability in the dentists' restorative decisions was explained by the perceptions of radiographic caries depth; however, among individual dentists, the range was from 29% for one dentist to 69% for another. A much lower percentage of the overall restorative variation was explained by microscopic depth, 18%. Like the finding of the only two previous European studies that quantified the role of radiographs on clinical decisions, this study demonstrated that dentists' perceptions of dental caries depth using bitewing radiographs play a major but variable role in their restorative decisions for approximal tooth surfaces.     

Molecular lipophilicity potential (MLP) in drug design. Complementing theoretical tools with experimental results

The Molecular Lipophilicity Potential (MLP) is a versatile tool in drug design whose present state and potential developments are reviewed here. The MLP offers a three-dimensional representation of lipophilicity as calculated from partition coefficients. The intermolecular recognition forces and intramolecular effects encoded in lipophilicity are presented, followed by the theoretical foundations and validation of the MLP. It is then demonstrated that the MLP allows for the first time to investigate the dependence of lipophilicity on conformation. As a matter of fact, the MLP combined with an exploration of the conformational space of a solute reveals its "chameleonic" behaviour, i.e. its capacity to adapt to the molecular environment. Other applications of the MLP are presented and illustrated, namely its integration into 3D-QSAR (Comparative Molecular Field Analysis, CoMFA) and its interest as a docking tool.     

The effect of the ingestion of ethanol on obstruction of the left ventricular outflow tract in hypertrophic cardiomyopathy

BACKGROUND: Ethanol causes vasodilation, which might have an adverse effect, due to increased obstruction of the left ventricular outflow tract, in patients with hypertrophic obstructive cardiomyopathy. We assessed the hemodynamic effects of the ingestion of ethanol, in an amount commonly consumed socially, in patients with hypertrophic cardiomyopathy. METHODS: We performed echocardiography in 36 patients before and several times after the ingestion of either 50 ml of 40 percent ethanol or an isocaloric placebo with the aroma of rum. Each patient received both ethanol and placebo, on different days. The patients, but not the physicians, were blinded to the content of the drink. We measured the sizes of the left atrium and left ventricle, the left-ventricular-wall thickness, blood pressure, heart rate, the degree of systolic anterior motion of the mitral valve, and the pressure gradient across the left ventricular outflow tract. RESULTS: The ingestion of ethanol regulated in a significant drop in the mean (+/- SD) systolic blood pressure (from 130.5 +/- 18.6 to 122.5 +/- 20.3 mm Hg, P<0.001), a significant increase in systolic anterior motion of the mitral valve (from a grade of 2.1 to a grade of 2.5, P<0.001), and a 63 percent increase in the mean gradient across the left ventricular outflow tract (from 38.1 +/- 26.5 to 62.2 +/- 42.4 mm Hg, P<0.001). These changes, which were not associated with symptoms, did not occur after the ingestion of placebo. CONCLUSION: The ingestion of a small amount of ethanol caused an increase in the gradient across the left ventricular outflow tract in patients with hypertrophic obstructive cardiomyopathy, which could have and adverse clinical effect.     

Questionnaire study and audit of use of angiotensin converting enzyme inhibitor and monitoring in general practice: the need for guidelines to prevent renal failure

OBJECTIVES: To determine the current pattern of use of angiotensin converting enzyme inhibitor and monitoring of renal function in general practice and to audit all admissions to a regional renal unit for uraemia related to use of these drugs. DESIGN: Postal questionnaire sent to 400 general practitioners; audit of clinical notes of all patients receiving these drugs in one large general practice; audit of all cases of uraemia (creatinine concentration >500 micromol/l) related to treatment presenting to hospital renal services over 12 months. SETTING: General practices in the North Wales health authority and one in central Manchester. Regional renal unit in Salford. MAIN OUTCOME MEASURES: Proportion of general practitioners who regularly monitored renal function before and after initiation of angiotensin converting enzyme inhibitors. Indications for treatment and details of monitoring of renal function in patients receiving these drugs. Incidence of related uraemia and evidence of comorbid disease, other aetiological factors, delayed detection, and patient outcome. RESULTS: 277 (69%) general practitioners replied; 235 (85%) checked renal function before but only 93 (34%) after the start of treatment, and 42 (15%) never checked renal function. Angiotensin converting enzyme inhibitors were prescribed for 162 patients from a total of 3625 aged >35 years (mean age 66.4 (SD 15.9) years). Monitoring of renal function occurred before treatment in 55 (45%) and after start of treatment in 35 (29%) of the 122 patients treated in general practice. Angiotensin converting enzyme inhibitors could be causally implicated in 9 (7%) of 135 admissions for uraemia (mean age 74.2 (7. 2) v 62.1 (2.1) years; P<0.01). 3 patients had renovascular disease and 6 had congestive cardiac failure with another intercurrent illness. Renal function had not been checked in any patient after the start of treatment; mean duration of illness before admission was 10.5 (3.2) days. Mean length of hospital stay was 20.9 (10.4) days; there were 8 survivors. CONCLUSION: Cases of uraemia related to treatment with angiotensin converting enzyme inhibitors are still encountered and are often detected late because of lack of judicious monitoring of renal function in vulnerable, often elderly, patients, especially at times of intercurrent illness. Guidelines for appropriate monitoring of renal function may help to minimise the problem.     

Morphology profiles obtained by reaction‐induced phase separation in epoxy/polysulfone/poly(ether imide) systems

The reaction‐induced phase separation in epoxy/aromatic diamine formulations simultaneously modified with two immiscible thermoplastics (TPs), poly(ether imide) (PEI) and polysulfone (PSF), has been studied. The epoxy monomer was based on the diglycidyl ether of bisphenol A (DGEBA) and the aromatic diamine was 4,4′‐methylenebis(3‐chloro 2,6‐diethylaniline) (MCDEA). Phase‐separation conversions are reported for various PSF/PEI proportions for blends containing 10 wt% total TP. On the basis of phase‐separation results, a conversion–composition phase diagram at 200 °C was compiled. This diagram was used to design particular cure cycles in order to generate different morphologies during the phase‐separation process. It was found that, depending on the PSF/PEI ratio employed, a particulate or a morphology characterized by a distribution of irregular PEI‐rich domains dispersed in an epoxy‐rich phase was obtained for initially miscible blends. Scanning electron microscopy (SEM) characterization revealed that the PEI‐rich phase exhibits a phase‐inverted structure and the epoxy‐rich matrix presents a bimodal size distribution of TP‐rich particles. For PSF/PEI ratios near the miscibility limit, slight temperature change result in morphology profiles. Copyright © 2005 Society of Chemical Industry     

Regulation of S-like ribonuclease levels in Arabidopsis. Antisense inhibition of RNS1 or RNS2 elevates anthocyanin accumulation

The S-like ribonucleases (RNases) RNS1 and RNS2 of Arabidopsis are members of the widespread T2 ribonuclease family, whose members also include the S-RNases, involved in gametophytic self-incompatibility in plants. Both RNS1 and RNS2 mRNAs have been shown previously to be induced by inorganic phosphate (Pi) starvation. In our study we examined this regulation at the protein level and determined the effects of diminishing RNS1 and RNS2 expression using antisense techniques. The Pi-starvation control of RNS1 and RNS2 was confirmed using antibodies specific for each protein. These specific antibodies also demonstrated that RNS1 is secreted, whereas RNS2 is intracellular. By introducing antisense constructs, mRNA accumulation was inhibited by up to 90% for RNS1 and up to 65% for RNS2. These plants contained abnormally high levels of anthocyanins, the production of which is often associated with several forms of stress, including Pi starvation. This effect demonstrates that diminishing the amounts of either RNS1 or RNS2 leads to effects that cannot be compensated for by the actions of other RNases, even though Arabidopsis contains a large number of different RNase activities. These results, together with the differential localization of the proteins, imply that RNS1 and RNS2 have distinct functions in the plant.     

The dermatologist in military operations

The military dermatologist has a specific and significant role in military operations--in time of war as well as in peace. Many dermatologists are unfamiliar with the impact that our specialty and cutaneous disease has upon the ability of the military to fulfill the missions, duties, and responsibilities assigned by our government. This article highlights a few of the recent or ongoing types of military operations in which our specialty plays a prominent part.     

A broad-spectrum microbicide with virucidal activity against sexually transmitted viruses

Sodium dodecyl sulfate (SDS), an alkyl sulfate surfactant derived from an organic alcohol, possesses surfactant properties but also denatures and unfolds both monomeric and subunit proteins. In preliminary experiments, we demonstrated that SDS is a potent inactivator of herpes simplex virus type 2 and human immunodeficiency virus type 1 at concentrations comparable to those used for the surfactant nonoxynol-9. We hypothesized that SDS might be capable of denaturing the capsid proteins of nonenveloped viruses. In this report, we demonstrate inactivation of rabbit, bovine, and human papillomaviruses after brief treatment with dilute solutions of SDS. Effective concentrations were nontoxic to rabbit skin and to split-thickness grafts of human foreskin epithelium. This is the first report of a microbicidal surfactant that will inactivate papillomaviruses. We propose that SDS is now a candidate microbicide for formulation and testing with humans.     

Development of housing programs to aid in the treatment of tuberculosis in homeless individuals: a pilot study

A long forehead disrupts the harmony among the facial components and may contribute to the semblance of facial aging. Slight forehead length disharmony on a senescent face can be corrected by placing the incision at the hairline, elevating the eyebrows through subcutaneous or subgaleal dissection, and removing excess skin without posterior scalp immobilization. For moderate to major reduction of the forehead length, the scalp is elevated back to the occipital region through a pretrichial incision, and relaxation incisions are made at a right angle to the vector of advancement. The entire scalp is then repositioned anteriorly, advancing the hairline caudally and shortening the forehead. Retraction of the scalp or excessive elevation of the eyebrows is prevented by anchoring the galeal fascia to the cranial bone using a bone-tunneling technique in one to three rows. The number of fixation rows is commensurate to the amount of advancement and rigidity of the scalp. The more immobile the scalp preoperatively, the more relaxation incisions and fixation tunnels are necessary. Following caudal repositioning of the scalp, the non-hair-bearing skin is excised, and a meticulous repair is done. These procedures have been performed in 180 patients with a high degree of satisfaction. Temporary hair loss was experienced in one smoker who underwent the most advancement through posterior scalp elevation and continued to smoke postoperatively. Also, on three patients in the subcutaneous forehead rhytidectomy group, two of whom were smokers, delayed healing was observed in the temple area because of compromised circulation requiring secondary revision.     

Ischio-vertebral dysplasia: a distinct entity

A total of 20 isolates of Blastocystis were characterized using a single set of polymerase chain reaction (PCR) primers. The amplification product revealed five types of pattern. All four isolates from Singapore yielded PCR products quite different from those of the local isolates. However, most of the local isolates showed a major product at either 280 or 500 bp, or both. We also suspected that the amplification product detected at 280 bp might be an indicator of the pathogenicity of this parasite. One isolate (M12) obtained from a monkey showed patterns similar to those of human isolates (10203 and KP1) and probably belongs to the same strain. The results indicate that the intraspecific or interstrain variations in these 20 Blastocystis isolates belong to 5 different patterns. The differences among isolates of the same strain revealed by the presence or absence of certain amplification products showed further intrastrain variations in this parasite.