Validity and reliability of laser-induced fluorescence measurements on carious root surfaces in vitro

The aim was to assess the validity of laser fluorescence (LF), visual inspection and surface texture on root caries lesions in vitro, related to histological lesion depths. Agreement on interdevice, interexaminer and intra-examiner levels as well as the influence of discolouration and surface texture on LF readings were investigated. Calibrated examiners assessed lesion colour and surface texture and performed measurements with 2 LF devices in 3 separate series at intervals of 1 week. Sections (300 mum thick) of 64 out of 93 teeth were obtained and examined under the microscope. Lesion depth was assessed with 2 references: from the delineated borderline of the original exposed root surface (ref. I), or if loss of surface continuity, the absolute lesion depth (ref. II). The correlation (Spearman rho) between LF readings and histological depth was low with values ranging from 0.22 (p > 0.05) to 0.31 (p < 0.05). LF 1 and LF 2 were significantly correlated with discolouration (rho = 0.52 and 0.46, respectively) and with surface texture denoted as hard (rho = 0.34 and 0.33, respectively). A significant correlation between colour and histological depth ref. I (rho = 0.51) and ref. II (rho = 0.56) was found. No significant correlation between surface texture and histological depth was found. The reliability, evaluated as intraclass correlation coefficient was for intra-examiner 0.99, interexaminer 0.97 and interdevice level 0.98. Large differences were found between 2 consecutive measurements, and high measurement errors indicated considerable deviation of individual measurements. Based on these findings, the LF device is not suitable as a diagnostic tool for root caries.

Streptokinase treatment of deep venous thrombosis of the lower extremity. Clinical, phlebographic and plethysmographic evaluation of early and late results

The investigation comprises 19 patients with acute deep vein thrombosis of the leg treated with streptokinase. The acute clinical symptoms rapidly subsided in 15 patients. Phlebography, performed immediately after treatment, revealed complete thrombus regression in 7 cases, restoration of venous flow but remnants of thrombi in 4 and no effect in 7. One woman was not evaluated radiologically due to pregnancy. The phlebographic restoration seemed to be correlated to the duration of the thrombotic symptoms. Follow-up examinations 6-50 months after the thrombotic incident demonstrated normal phlebograms in 8 patients, all of whom were also free from post-thrombotic symptoms. Venous occlusion plethysmography confirmed that these patients had a normal venous outflow capacity and valvular function in the relevant limbs. By contrast, the remaining 11 patients, with more or less extensive remnants of thrombi at the follow-up phlebography, were found to have plethysmographic signs of venous obstruction and sometimes also valvular insufficiency. The results indicate that thrombolytic treatment is able to give a complete and lasting anatomical and functional restitution of the deep veins after an acute thrombosis in the leg, provided that treatment is induced early enough.

Effects of sulfonylurea on the secretion and disposition of insulin and C-peptide

In an attempt to examine the influence of sulfonylurea on the secretion, disposition and effect of insulin, 9 diabetic patients were studied during three one-month medications with (a) chlorpropamide (t1/2 greater than 24 h) once daily, (b) glipizide (t1/2 2-4 h) once daily, and (c) glipizide in divided dosage. The food intake of each patient was identical during each examination period. Blood concentrations of C-peptide, insulin, glucose, and drugs were determined before and after breakfast and lunch on the 4th day of each examination period. As expected, once-daily administration of glipizide led to higher after-breakfast concentrations of the drug than when the dose was divided. However, the C-peptide changes following breakfast were similar both during these two treatments and also during chlorpropamide, indicating that the amounts of insulin released from the pancreas were equivalent. In spite of this, glipizide once daily yielded 60-70% more insulin in systemic blood following breakfast than did the two other treatments. Reasonably, this signifies that the hepatic extraction of insulin was reduced during once-daily glipizide, allowing more insulin to reach systemic circulation. In addition, this was found to promote a more effective utilization of glucose following breakfast. Following lunch, the C-peptide release, the plasma insulin increase and the blood glucose reduction were greater when glipizide was given in divided dosage than when once-daily glipizide or chlorpropamide was employed. This occurred even though the after-lunch concentration of glipizide in systemic blood was lower rather than higher during divided than during once-daily administration. This supports the notion that the effect of orally administered sulfonylurea is determined not only by its concentration in systemic blood but also by its gastroenterohepatic appearance. Glipizide may offer greater therapeutic flexibility than chlorpropamide, but further studies are required to define the optimum choice and use of sulfonylureas.

Polymorphic acetylator phenotype and systemic lupus erythematosus

Out of 69 patients with spontaneous systemic lupus erythematosus (SLE), phenotyped for polymorphic acetylation with sulphadimidine, 52 (75%) were slow acetylators. In the subgroup of SLE patients with chronic biologically false positive seroreactions for syphilis the percentage of slow acetylators was even higher, 88%. In the majority of the slow acetylators the disease had started later and had followed a milder course than in rapid acetylators. Cutaneous reactions suspected to be drug-induced were seen in 19 (17 slow acetylators) during an observation period of 3--7 years. The reactions were mostly of exanthematous or urticarial type but also fixed type of eruption was seen. Provocation tests with the suspected drug were performed in 14 patients. In 5 cases it could be demonstrated that the eruption was caused by the drug. The predominance of slow acetylators among our patients with spontaneous SLE was the same as has been observed in drug-induced SLE. This suggests a similar genetic background.

Antibacterial effect of ozone on cariogenic bacterial species

OBJECTIVE

The aim was to evaluate the antibacterial effect of ozone on cariogenic bacterial species with and without the presence of saliva and a possible effect on the salivary proteins.

METHODS

Suspensions of Actinomyces naeslundii (ACTCC 12104(T)), Lactobacilli casei (N CTC 151) and Streptococcus mutans (NCTC 10449), in salt buffer or in saliva, were exposed to ozone gas delivered by the ozone generator Healozone 2130C. Aliquots of the suspensions were taken after 10, 30 and 60s ozone exposures and cultivated on agar plates. Initial number of bacteria per ml was 8.0 x 10(7) (SD 2.2 x 10(7)) (A. naeslundii), 1.0 x 10(8) (SD 3.1 x 10(6)) (L. casei) and 1.0 x 10(8) (SD 7.0 x 10(5)) (S. mutans), respectively. The proteins were separated by SDS electrophoresis and visualized by silver staining.

RESULTS

In salt buffer 92%, 73% and 64% of the initial numbers of A. naeslundii, S. mutans and L. casei, respectively, were killed already after 10s ozone exposure, while approximately 99.9% of the bacteria were dead after a 60s exposure. After 10 and 30s, but not after 60s exposure to ozone, S. mutans and L. casei were less efficiently killed in saliva compared to the salt buffer. Various saliva proteins were degraded by ozone after a 60s exposure.

CONCLUSIONS

The cariogenic species S. mutans, L. casei and A. naeslundii were almost eliminated following 60s of ozone treatment. This killing was reduced in the presence of saliva although increasing the ozone application time to 60s overcame these reductants in saliva. Detection of altered salivary proteins indicates that saliva components constitute additional targets for ozone.

Procedure-related pain among adult patients with hematologic malignancies

BACKGROUND

Cancer patients undergo numerous invasive diagnostic procedures. However, there are only sparse data on the characteristics and determinants for procedure-related pain among adult cancer patients.

METHODS

In this prospective study, we evaluated the characteristics and determinants of procedure-related pain in 235 consecutive hematologic patients (M/F:126/109; median age 62 years, range 20-89 years) undergoing a bone marrow aspiration/biopsy (BMA) under local anesthesia. Questionnaires were used to assess patients before-, 10 min and 1-7 days post BMA. Using logistic regression models, we calculated odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

165/235 (70%) patients reported pain during BMA; 92 (56%), 53 (32%) and 5 (3%) of these indicated moderate [visual analogue scale (VAS)>or=30 mm], severe (VAS>54 mm) and worst possible pain (VAS=100 mm), respectively. On multivariate analyses, pre-existing pain (OR=2.60 95% CI 1.26-5.36), anxiety about the diagnostic outcome of BMA (OR=3.17 95% CI 1.54-6.52), anxiety about needle-insertion (OR=2.49 95% CI 1.22-5.10) and low employment status (sick-leave/unemployed) (OR=3.14 95% CI 1.31-7.55) were independently associated with an increased risk of pain during BMA. At follow-up 10 min after BMA, 40/235 (17%) patients reported pain. At 1, 3, 6 and 7 days post BMA, pain was present in 137 (64%), 90 (42%), 43 (20%) and 25 (12%) patients, respectively.

CONCLUSIONS

We found that 3/4 of hematologic patients who underwent BMA reported procedural pain; one third of these patients indicated severe pain. Pre-existing pain, anxiety about the diagnostic outcome of BMA or needle-insertion, and low employment status were independent risk factors.

Female-male differences at various clinical steps of tuberculosis management in rural Bangladesh

A registry data-based study of 3,600 patients systematically drawn from out-patient clinic, laboratory and tuberculosis (TB) treatment registers (1200 from each) examined female-male differences at various clinical steps of TB management and compared selective indicators with published results. Female-to-male ratios (FMR) declined at the following clinical steps: respiratory patients seeking out-patient care (0.81), TB suspects submitting sputum for testing (0.52) and smear-positive test results (0.38), but the decline ceased at treatment initiation (0.41). Compared to 1997, the FMR in 2000 had decreased for out-patient clinics and sputum submission for testing, but had increased for smear-positive test results and treatment initiation. More female than male patients who underwent treatment achieved cure (93% vs. 89%). Lower female representation at the different clinical steps of TB management persists.

Water absorption in polyethylene under external electric fields

Monte Carlo simulations of the solubility and structure of water in polyethylene in thermodynamic equilibrium with liquid water were performed in external fields ranging from 2 x 10(5) to 4 x 10(9) V/m. For a given equilibrium temperature and pressure, the water solubility decreases at higher fields. This occurs since it is energetically favorable for water molecules to be in the pure water phase than in the polyethylene matrix at high field strengths, and results in an increased density in the water phase. However, fields relevant to high voltage conduction (in the absence of defects that can lead to large local field strengths) do not change the solubility. In addition, at large fields the number of water clusters decreases for all cluster sizes. The rate of decrease is highest for large clusters, and a larger fraction of water molecules exist as monomers in the polyethylene matrix at high fields. Large fields also cause alignment of the water molecules, which leads to more clusters with linear topologies and hence an increase in the cluster radius of gyration.

Monte Carlo simulations of equilibrium solubilities and structure of water in n-alkanes and polyethylene

Gibbs ensemble Monte Carlo methods based on a force field that combines the simple point charge [Berendsen et al., in Intermolecular Forces, edited by Pullman (Reidel, Dordrecht, 1981), p. 331] and transferable potentials for phase equilibria [Martin and Siepmann, J. Phys. Chem. B 102, 2659 (1998)] models were used to study the equilibrium properties of binary systems consisting of water and n-alkanes with chain lengths from hexane to hexadecane. In addition, systems where extended linear alkane chains (up to 300 carbon units long) were used to represent amorphous polyethylene were simulated in the presence of water using a connectivity altering osmotic Gibbs ensemble. In these simulations the equilibrium between a liquid water phase and a polymer phase into which water was inserted was studied. The predicted solubilities, which were determined between 350 and 550 K, are in good agreement with experiment, where experimental results are available, and the density of water molecules in the hydrocarbons is approximately 63% as high as in saturated water vapor under the same conditions. At the lower temperatures most of the water exists as monomers; increasing the temperature leads to an increase in the density of water in the alkane phase and hence in the fraction of molecules that participate in clusters. Dimers are the most prevalent clusters in all hydrocarbons and at all temperatures studied, and the fraction of clusters of given size decrease with increasing cluster size. A large fraction of trimers, tetramers, and pentamers, which are the cluster sizes for which topologies have been studied, are cyclic at low temperatures, but at higher temperatures linear structures predominate. The same properties are observed for pure water vapor clusters in equilibrium with the liquid phase, showing that the cluster topologies are not significantly affected by the surrounding hydrocarbon.