Rheological aspects of mucin-containing solutions and saliva substitutes.

In this study rheological properties of aqueous solutions of mucin, albumin and mucin-albumin have been investigated in search for saliva substitutes. They were compared with commercially available saliva substitutes on the one hand and natural human saliva on the other hand. For the latter a few measurements on saliva are reported here in addition to previously reported measurements done in our laboratory. Proteins absorb at the interface and saliva proteins do so strongly and rapidly. Therefore rheological measurements were carried out on the interface and on the bulk underneath the layer. In both cases the flow curve and the complex viscosity was determined. The results show that specific mucin-albumin solutions were rheologically similar to human whole saliva with respect to both bulk liquid and surface properties. The rheological properties of commercial saliva substitutes were essentially different from those of human saliva. It is concluded that mucin-albumin solutions have good perspectives as saliva substitutes.


Adsorption of bovine serum albumin onto glassy carbon in a Couette flow. Effect of shear rate on the adsorption kinetics and on the structure of the adsorbed proteic layer.

Adsorption of bovine serum albumin onto glassy carbon is investigated by analysing the time-variation of the double-layer capacitance recorded during the adsorption process. The effect of shear rate is investigated under laminar conditions in a Couette flow. Stationary and sinusoidally modulated values of the shear rate are imposed over the (0-200 s-1) range. The flow conditions are shown to play an essential role by markedly modifying the rate of all the steps (three at most) involved in the adsorption mechanism. Moreover, the structure of the adsorbed layers in the intermediate and final states are also strongly modified, an increase of the shear rate increasing the interaction between the protein and the electrode. Piezoelectric properties of albumin are invoked to account for the experimental results.


The mechanism of erythrocyte sedimentation in Westergren's examination.

The authors deduced the equation that describes the sedimentation of erythrocytes as the function of time, hematocrit, hemoglobin and some plasma protein concentrations and the citrate viscosity and density. This values served to describe plasma and erythrocyte density, plasma viscosity, erythrocyte aggregation and the influence of suspension concentration on the erythrocyte sedimentation rate. The influence of citrate on blood dilution (the reduction of hematocrit and plasma protein concentrations) was also considered. A good agreement between the observed and predicted values was obtained.


A new rheometer with special features designed for bronchial mucus analysis in clinical practice.

Changes in production and in physico-chemical properties of bronchial mucus is a common denominator of many pulmonary diseases. A rheometer with innovative features aimed at bronchial mucus routine investigation in clinical practice at the bedside of the patient has been designed. Searle-type configuration with a coaxial cylinder sensor system and the Mooney-Ewart geometry has been adopted. Another new feature is that bob and cup are disposable. Dynamic viscoelasticity is calculated through a microprocessor with specific software and by means of a magnetic torque--motor electronically driven by the microprocessor. The self-zeroing procedure and the autorange greatly simplify the measuring-cycle which is driven by only one switch. Data (eta and G') are automatically printed on paper. The whole measuring-cycle at the bedside of the patient takes 3-5 min, so that in 1h about 12 samples can be investigated.


Changes in mechanical properties with DMSO-induced differentiation of HL-60 cells.

We measured changes in the deformability of human promyelocytic leukemic (HL-60) cells induced to differentiate for 5-6 days along the granulocyte pathway by 1.25% dimethylsulfoxide (DMSO). Differentiation resulted in an approximately 90% reduction in the transit times of the cells through capillary-sized pores over a range of aspiration pressures. Cell volume, as measured by two methods, decreased by an average of 35%. To account for the contribution of the volume decrease to the decrease in transit time, the liquid drop model, developed to describe neutrophil deformability, was used to calculate an apparent viscosity of the cells during this deformation. The apparent viscosity of both uninduced and induced HL-60 cells was a function of aspiration pressure, and an approximately 80% reduction in viscosity occurred with induction, as determined by regression analysis. The deformation rate-dependent viscosities of the induced cells were between 65 and 240 Pa-sec, values similar to those measured for circulating neutrophils. To assess the role of polymerized actin in these viscosity changes, intracellular F-actin content was measured, and the effect of dihydrocytochalasin B (DHB), an agent that disrupts actin polymerization, was determined. Despite the significant decrease in cellular viscosity, F-actin content per cell volume did not change significantly after induced differentiation. Treatment with 3 and 30 microM DHB lowered cellular F-actin content in a dose-dependent manner in both uninduced and induced cells. Cellular viscosity of both uninduced and induced cells decreased sharply with 3 microM DHB treatment (85% and 76% respectively). 30 microM DHB treatment caused a further significant reduction in the viscosity of uninduced cells, but for induced cells the additional decrease in viscosity was not significant. These data indicate that reductions in both cell volume and intrinsic viscosity contribute to the increased deformability of HL-60 cells with DMSO-induced differentiation. However, changes in the concentration of F-actin cannot account for the decrease in cellular viscosity that occurs.


Unsteady flow of Casson fluids through the eccentric circular tube.

As a model of the flow through the false lumen of the dissecting aortic aneurysm, the starting and stopping flows of the Casson fluid through the eccentric circular tube are studied numerically. The calculations are performed by using the one-direction fully developed unsteady flow model. The calculation results show that the non-Newtonian property of the Casson fluid has the following two effects. One is the decrease in the flow rate through the false lumen, the other is the effect to strengthen the non-uniformity of the velocity distribution in the false lumen. Moreover, the calculations based on a triphasic waveform measured by McDonald are performed and the development of the dissecting aortic aneurysm is discussed on the basis of the calculated wall shear stress.


Improved diagnosis with digital radiography.

In radiodiagnosis, much effort is spent in reducing the radiation dose and simultaneously improving the information obtained with radiographs. Computer technology has the potential to significantly impact radiography in medicine and in dentistry to achieve these goals. Advanced digital imaging techniques will be available for the general practitioner within the next decade. Storage and retrieval of images, contrast enhancement, and noise reduction are some examples of basic image manipulation tools. Subtraction radiography and image reconstruction will improve diagnosis and treatment planning. The clinical knowledge of dentists and radiologists will be incorporated into computer programs to perform more sophisticated tasks in the form of automated image analysis and computer-aided image interpretation.


Application of diffractometry and a linear image sensor to measurement of erythrocyte deformability.

We applied laser diffractometry and a linear image sensor to measurement of erythrocyte deformability to detect the light intensity pattern of the diffraction image. Deformability was evaluated as the deformability index (DI), calculated from the width and length of the diffraction pattern ellipse, estimated by the linear image sensor. With the erythrocytes under various shear stresses, the DI was linearly related to results by the geometric method (r = 0.996, p < 0.01). The coefficient of variance of DI at a shear stress of 236 dynes/cm2 was 0.2% (seven human blood samples), which was satisfactory for practical use. The DI was independent of the erythrocyte concentration in the range of 1.5 x 10(7)-5.0 x 10(7) cells/ml of suspension. Correlation between the DI and the logarithm of shear stress was linear in the range of 5 to 350 dynes/cm2 of shear stress in suspension media of different viscosities. Heat-treatment, which decreased membrane flexibility, caused parallel reduction of the DI plotted against the logarithm of shear stress. The method was sensitive and gave reproducible results. It may be useful for clinical applications.


Orthodontic treatment in the mixed dentition for the general dentist.

Mixed dentition treatment is an important subject because early treatment could not only correct the occlusion but also may ensure normal development of the teeth. Proper arch form and dental relationships in the mixed dentition lessen the need for additional orthodontic treatment. The objectives in mixed dentition orthodontic therapy are to correct dental arch irregularities, occlusal and jaw relation abnormalities, and to eliminate functional interferences.


A numerical simulation of intimal thickening under shear in arteries.

A model of intima thickening proposed by Friedman and his coworkers (1,2) is incorporated in our computer code to simulate the growth of intima under shear. The computer code is based on a finite volume method in a boundary-fitted coordinate system. It is found that the model yields an evenly-distributed thickening over a straight, smooth vessel wall. However, in a stenosed or a curved artery, thicker intima can be formed in preferential regions due to unevenly-distributed wall shear stresses. The results clearly demonstrate the correlations among the geometry, wall shear rate and the plaque localization in arteries. The model is applied to a straight artery with a stenosis or sinus, a smooth curved artery and a stenosed curved artery. The effects of stenosis/sinus and lumen curvature on the flows and the intimal thickening are studied. The simulation provides a numerical visualization of the intimal thickening in a dynamic way.


Growth and development in orthodontics.

The recent literature on growth and development of the face and dentition includes important articles about assessment of growth, maturation, growth in the vertical dimension, treatment effects, experimental growth, and craniofacial anomalies. An underlying theme can be detected in these reports--the individuality of the child and his or her response to treatment. Central trends can be determined from growth data, but these generalizations should be applied with caution. When formulating treatment goals and planning mechanics, great variability can exist among growing children.


On transport of suspended particulates in tube flow.

Blood cells suspended in shear flows exhibit much larger dispersive motions than those predicted by the Stokes-Einstein formula for Brownian diffusion. The lateral migration and the erratic motions of the 8 microns red blood cells (RBC) is thought to be analogous to a diffusive process. It is shown that the often cited convective-diffusion theory may not be an adequate model for describing the transverse migration of suspended cells in blood flow. A comprehensive review of both the classical theory and of contemporary work in particle transport is presented, with particular emphasis on low Reynolds number tube flows. The mechanisms of Taylor dispersion, the effects of Brownian perturbations on translational and rotational motions of the suspended particles in shear fields, and the influence of integratable and chaotic advections, are individually examined. The classical experiment by Segre and Silberberg (1962) lead us to believe that particle hydrodynamics may play an important role in transverse migrations. In this light, we have further examined the hydrodynamic aspects of the so-called "tubular pinch" effect, the lateral migration of rigid spheres. We have also discussed the transverse motions of liquid drops, and the reversibility of the organization of suspensions in transport. The convective accelerations in the entrance region of a tube can produce relative velocities between fluid medium and various type of particulates if there is a difference in density. The deformable RBC, an "active-type" particle, can provide feedback to the flow from both mass and momentum considerations; the more rigid platelet, a "passive-type" particle, will experience a much smaller relative velocity as compared to the RBC. We may expect that particles of different densities are transported to different equilibrium annular positions before entering the fully developed flow region. The erratic, lateral movement of suspended particulates in steady laminar tube flow can be described by the usual Lagrangian coordinates.


Complications of orthodontic treatment.

Orthodontic treatment may in some cases initiate damage to teeth and supporting tissues (decalcification and gingivitis) or root resorption, pulp damage, allergic reactions, or craniomandibular dysfunction. This review updates some interesting findings regarding these problems.


Current concepts in education and research in orthodontics.

The science of dentistry is quickly advancing toward the 21st century. The constant innovations in dental material development, along with the ever-new concepts that are emerging in basic science and clinical research, are helping dentists to design methods of practice that have a more biologic and preventive substrate and a less restorative aim. As a result, all specialties of dentistry are undergoing constant changes in an effort to conform and manage the need of an educated, modern society. This report highlights some current concepts in orthodontic education and clinical research that are shaping the way that the specialty of orthodontics is taught and practiced.


Dentin bonding agents.

Dentin bonding is discussed both in terms of the substrate and in terms of newer bonding systems that have recently been marketed. The most popular bonding systems are presented along with several new systems from Germany and Japan. Etching of dentin is discussed in terms of both its advantages and its disadvantages. Bonding systems can be used to repair fractured teeth as well as to restore carious teeth. This area of knowledge is rapidly expanding. Most of the new products are improvements over their predecessors.


The need for long-term multicenter treatment assessment of craniofacial developmental disorders including cleft lip and palate.

There has been an increase of interest in recent years in comparing treatment outcome in patients with craniofacial anomalies, including cleft lip and palate. When a treatment result is to be evaluated, it is important that it is multifaceted, taking all aspects into account. A comparison between treatment outcome in six centers showed that those with simple procedures and few surgeons involved in the primary operations had as good treatment results as those with more complicated treatment procedures. The center that used presurgical orthopedics with extraoral strapping in its treatment program ranked low as did the center employing primary bone grafting as part of the treatment program when compared with the other centers.


The child as a dental patient.

The management of children's anxiety continues to be at the focal point of research into the child as a dental patient. This review is concerned first with different psychological concepts of anxiety, including psychoanalytic approaches, infant attachments, and behavioral and cognitive approaches. Incidents contributing to fear of dentistry and strategies used to manage anxiety and behavioral problems are then considered. The next section deals with coping mechanisms children devise to deal with anxiety-provoking situations. Finally, some comments are made on groups of children with special needs. The decline in caries and an increase in the awareness by dentists of the psychological needs of children should enable the next generation to be less fearful and more positive about the benefits of good dental health.


Advances in the treatment of acquired and developmental defects of hard dental tissues.

With the decline in dental caries, the dental profession and the general public have become sensitized to the "new" specialty of cosmetic dentistry. As a consequence, research in the field of dental materials for the ideal, most natural restorative materials and techniques has become a primary focus and has had a profound influence on dental education and practice. This brief article will highlight some of these newer concepts.


Diagnosis and treatment planning in orthodontics.

Orthodontic diagnosis and treatment planning topics either reflect the new technology available in the health fields or reiterate the older material that reemerges from generation to generation. Issues that are presented still display the dissatisfaction of their examiners in terms of frustration and equivocal results. Well-controlled prospective and retrospective studies require documented long-term evaluations to be clinically useful as an aid in diagnosis or formulation of treatment planning principles.


[Relation among syndrome of spleen deficiency and stagnation of liver-qi and electrogastrogram, gastric mucosal pathology and pulse-cardiovascular function in chronic gastric diseases].

In this research, Syndrome of Deficiency of Spleen (DS) and Stagnation of Liver-Qi (SLQ) as well as observations of electrogastrogram (EGG), gastric mucosal pathology and pulse cardiovascular examination were investigated in 56 cases of chronic gastric diseases (CGD). The results showed: (1) In SLQ with DS the amplitude of EGG was significantly higher than that of the control group (P < 0.01), it often indicated the active period of pathologic change, but in DS with SLQ, the amplitude of EGG was significantly lower than that of the control group (P < 0.01), it frequently denoted the static period. In case that DS equalled to SLQ, the amplitude of EGG was significantly higher than that of the control group (P < 0.01). It revealed that there were no significant difference between the patient's number of static and active periods (P > 0.05). It is valuable in Syndrome Differentiation of Deficiency and Excess and analysis of Superficiality and Origin in CGD. (2) Cardiovascular function was also affected in Syndrome differentiation of DS and SLQ. DS with SLQ manifested itself as reduction of left ventricle pump and declination for metabolism of microcirculation, they had significant difference as compared with the control group (P < 0.05), while SLQ with DS or equality between DS and SLQ had the normal function of left ventricle pump and metabolism of microcirculation, even though cardiac output were higher than that of control group (P < 0.05). It showed that the traditional Chinese medicine theory of interrelation among Heart and Spleen, Liver had their own hemodynamic bases.


[Relation between Helicobacter pylori and pathogenesis of chronic atrophic gastritis and the research of its prevention and treatment].

The total detectable rate of Helicobacter pylori (HP) of 485 patients suffering from gastric diseases was 59.6%. The HP in gastric mucosa of chronic atrophic gastritis (CAG) patients was separated from the cell culture in vitro and transferred successively. The mice were perfused with exciccate alum, and the rabbits with aspirin to injure their gastric mucosa, then HP was perfused. Result showed that the change of experimental animals was identical with that of CAG patients by means of bacteriological and pathological examination. It revealed that HP was in agreement with Robert Koch's three principles about pathogenic bacteria. According to the bacterial infectious hypothesis of CAG, 53 Chinese medicinal herbs and prescriptions were investigated with bacteriostatic test. Panax notogenseng and Magnolia officinalis were discovered to be sensitive, Prunus mume and Corydalis yanhusuo were moderate sensitive, and Coptis chinensis and Rheum palmatum highly sensitive to HP. Decoction of Clearing up the Heat and Relieving the Blood Stasis and No.2 recipe of Huowei were used to treat 70 CAG patients with Stomach Heat Syndrome. The effective rate of gastroscopic examination was 85.7%, that of pathological study was 80%. In comparing with the group of Shanjiu Weitai, there was significant difference between the traditional Chinese medicine treated group and Shanjiu Weitai control group, the former being markedly better.


[Combined traditional Chinese and Western medicine in the treatment of intractable ulcer].

The curative effects of combined traditional Chinese and Western medicine in 508 patients of intractable peptic ulcer with gastroscopy confirmation were evaluated. The patients were divided into Chuanjia Weidan group (Group I, 260 patients) and cimetidine group (Group II, 248 patients). Debridement, injection and drug covering of ulcer surfaces were followed by oral Chinese medicine Chuanjia Weidan (50 g daily) or cimetidine (800 mg every night) for 4 weeks. In group I, 95.6% of patients with gastric ulcer were cured, while in group II, 87.2% with the same disease were cured. For the patients with duodenal ulcer in group I and group II, 88.2% and 85.2% were cured respectively (P > 0.05). 70% of the main symptoms were remitted in the first and 97% in the second week in group I, whereas in group II, the remission occurred in 33% and 64.5% respectively (P < 0.05). The clearance rate of Helicobacter pylori for gastric ulcer and duodenal ulcer in group I was 71.2% and 78.3% respectively, but 5.3% and 7.2% in group II (P < 0.01). Eighteen months after the treatment, 13% of the patients with gastric ulcer and 14.2% with duodenal ulcer in group I relapsed, while that of group II was 63% and 71.3% respectively (P < 0.01). The authors concluded that debridement, injection and drug covering of ulcer surface under the endoscopy associated with oral administration of Chinese medicine Chuanjia Weidan is efficacious in treating intractable peptic ulcer.


[Effects of various qigong breathing pattern on variability of heart rate].

The effects of four various Qigong breathing pattern on variability of heart rate have been observed by R-R interval spectral analysis in 26 healthy volunteers. The differences in the shape of peaks in spectra were found to be correlated with the Qigong breathing pattern. The amplitude of peak in high-frequency area increased with a reduction of the low-frequency 2/high-frequency (LF2/HF) ratio during the Qigong breathing pattern A, B, and C, indicating the vagal activity increased during above-mentioned three Qigong breathing pattern. However, the amplitude of peak decreased and LF2/HF ratio increased during the Qigong breathing pattern D, it reflected the increase of sympathetic activities. Thus, the results suggested that the Qigong could indirectly regulate the function of viscera after controlling the direct breathing pattern.


[Efficacy of danggui funing pill in treating 162 cases of abdominal pain].

Therapeutic effect of Danggui Funing (DGFN) pill in treating 207 patients with abdominal pain were studied with control. Among 207 patients with abdominal pain, 162 of DGFN pill group and 45 of control groups (35 atropine group and 10 placebo group). The effective rate of abdominal pain in the three groups were 93.27%, 97.14% and 0% respectively. There was no significant difference (P > 0.05) between the DGFN pill group and the atropine group, but the difference were statistically significant (P < 0.01) between the above-mentioned two groups and the placebo group. These results revealed that the therapeutic effect of DGFN pill was reliable. There were three pharmacological effects of DGFN pill: The blocking on M, alpha and H1 receptors, the analgesic effect and the antiseptic effect. The DGFN pill was the drug of rapid-efficacy and low toxicity.


[Clinical study of rapid bladder filling agent].

The Rapid Bladder Filling Agent (RBFA) was prepared with Polyporus umbellatus, Poria cocos and Furosemidum. The urinary volume and the best filling time of urinary bladder were observed with ultrasonography in 211 cases. The result showed that in experimental group the largest urinary volume in unit time was more than that in control group and shortest filling time was shorter (30.35 +/- 7.9 min) in comparing with control group (145.6 +/- 50.1 min). Clinical observation for 1180 cases proved that the RBFA had the effects of raising the quality of ultrasonographic examination and escalating work efficiency, shortening the waiting time of patients and relieving patients' suffering from excessive filling of urinary bladder. The effective time of the RBFA was fast but the duration was short. The RBFA had no adverse effect.


[Blood and urine prostaglandin E2 and prostaglandin F2 alpha in patients with chronic gastritis and peptic ulcer].

The blood and urine prostaglandin E2 (PGE2), Prostaglandin F2 alpha (PGF2 alpha) in 106 cases of chronic gastritis and peptic ulcer were investigated by RIA. Meanwhile, the relationship among PGE2, PGF2 alpha and the Syndromes of TCM were approached. The result showed: In comparing with the normal control, the blood and urine PGE2 of 106 cases were obviously higher (P < 0.01), but PGF2 alpha was not (P > 0.05). The urine PGE2 and PGF2 alpha of moderate gastritis were markedly higher than those of mild gastritis (P < 0.05), but there were no significant difference between blood PGE2, PGF2 alpha of moderate gastritis and those of mild gastritis (P > 0.05). The blood PGE2, PGE2/PGF2 alpha ratio of Dampness-Heat in Spleen-Stomach Syndrome and the blood PGE2/PGF2 alpha ratio of incoordination between Liver and Stomach Syndrome were higher than those of Spleen Stomach Deficiency Syndrome in all the cases (P < 0.05). Compared with the normal control, both the decreased amplitude of blood PGE2/urine PGE2 and increased amplitude of blood PGF2 alpha/urine PGF2 alpha ratio showed as following: Spleen-Stomach Deficiency Syndrome > incoordination between Liver and stomach Syndrome > Dampness-Heat in Spleen-Stomach Syndrome. This study suggested: (1) There was a close relation between PGE2 and chronic gastritis and peptic ulcer; (2) There was no correlation between blood PGE2, PGF2 alpha and urine PGE2, PGF2 alpha; (3) PG was possibly a useful objective parameter to the Syndrome Differentiation in TCM.


[Effects of buyang huanwu decoction on changes of oxygen free radical and cell ultrastructure in rats with experimental brain edema].

Effects of Buyang Huanwu decoction (BYHWD) on the change of oxygen free radical and cell ultrastructure were observed in rats with acute brain edema induced by pertussis vaccine (PV). The results showed that BYHWD could decrease significantly the contents of brain tissue protein and malondialdehyde, and raise the declining of superoxide dismutase and glutathione peroxidase activities. Also, BYHWD could reduce markedly the transport of pinosome in the left cerebral capillary endothelial cell, and lessen slightly the swelling of cerebral perivascular astrocyte processes and mitochondria in neuron. There was no significant reduction of water content in the left hemisphere on intravenous administration of BYHWD before and after injecting PV; while that in the right hemisphere, it was less remarkable in BYHWD group than that in control (P < 0.05). Hence, it suggests that BYHWD had the evident effects in antagonizing the damage of blood brain barrier and encephalic cell caused by free radical in brain edema.


[Experimental and clinical research of dachengqi decoction in treating post-traumatic respiratory distress syndrome].

12 cases of post-traumatic RDS treated with Dachengqi Decoction were reported. 10 patients survived, which showed a bright prospect for the treatment of post-traumatic RDS. In the experimental study, model of RDS was set up in rabbits. The pressure of PaO2 was determined and the morphologic changes of their lung tissues was observed after the rabbits were perfused with Dachengqi Decoction. The results showed that their PaO2 were markedly increased and lung conditions greatly improved, which provided an experimental basis for RDS with Dachengqi Decoction. Among 12 cases; nine were moderate cases and three serious ones. During the course of treatment with Dachengqi Decoction, two patients died, covering only 16.6% of the total number of patients. This fact confirms the efficacy of Dachengqi Decoction in treating the post-traumatic RDS.


Health hazards in the semiconductor industry. A review.

The development of semiconductor production has been accompanied by an increased use of toxic production materials and an increased release of potential toxic wastes, which are harmful to health and environment. This paper gives an overview of occupational health hazards resulting from production materials in the microelectronics industry and from waste products originating as gases from plasma etching processes in photolithography during semiconductor production. The paper proposes methods for using experimental toxicology to investigate the occupational risks from complex mixtures of chemicals in the semiconductor industry.


An ergonomic system for assessing postural stress in workplaces.

A new method has been developed to enable the ergonomic assessment of stress associated with posture at the workplace. It enables evaluations of the load resulting from working postures at workplaces where standing and walking postures dominate. The method also offers the possibility of estimating the preexisting load already at the stage of workplace designing. This may prove useful in evaluating both the global load and giving the designer an idea about the effect of individual design decisions on changes of the postural load. The method has been used to compare the postural stress at several workplaces in the textile industry and it seems to perform satisfactorily.


The influence of occupational and non-occupational factors on chronic fatigue in women.

The aim of the present study was to assess the significance of different types of loads to which working women are subjected in relation to reported chronic fatigue. The investigation involved 255 women workers from two different occupational groups. The first group was employed at knitting and the second at assembly lines. Their level of chronic fatigue was assessed. We also analysed the influence of 30 variables on fatigue level. These variables concerned: a) physical and psychological workload, b) organizational (social) climate of work, and c) demographic and family factors. It was found that the most important factor influencing chronic fatigue was "experiencing emotional tension" resulting from family problems. Other factors, having substantial significance for the development of increased fatigue level were also associated with emotional tension and resulted from the social climate in the workplace.


Occupational and environmental exposure to nickel in Poland.

Exposure to nickel was evaluated on the base of nickel in urine concentration (Ni-U) in 649 persons both adults and pre-school and school children; 241 persons were occupationally exposed in steel-mill and rolling-mill. Environmentally exposed groups consisted of inhabitants of industrial and rural towns. The occupationally exposed groups showed Ni-U mean concentrations amounted to 25.7, 18.1, 15.9, and 15.7 micrograms/m3. In environmentally exposed groups of adults, Ni-U concentrations were almost equal to those in persons inhabiting industrial and rural areas-7.8 and 7.7.micrograms/dm3, respectively. Ni-U concentrations in children groups were more differentiated 8.5 and 9.2 micrograms/dm3 in rural area and 9.9 and 10.6 micrograms/dm3 in industrial area. The recommended mean group allowable Ni-U concentrations for occupational exposure amounts to 12 micrograms/dm3 and for environmental exposure 2.7 micrograms/dm3. In view of the above mentioned Ni-U allowable values it is evident that there exist significant occupational exposure and elevated environmental exposure in the defined percent of the investigated population.


The study of exposure to cadmium in the general population. II. Morbidity studies.

An epidemiological study was performed to assess whether environmental pollution by cadmium as found in cadmium polluted areas of CSFR (Pribram and Frýdek-Mistek) is associated with changes in biological indicators of renal dysfunction in non-occupationally exposed population groups. Polluted areas were chosen on the basis of existing sources of Cd emission. The city of Prague was selected as a control area. Environmental monitoring (Cd in air, dust fall and soil) did not confirm significant contamination of selected areas. It was found that Cd levels in urine (Cd-U) of inhabitants living in areas chosen as Cd-contaminated were significantly higher than in the control area. Differences in concentrations of Cd in blood (Cd-B) levels between individual areas were not significant. No significant differences between the study populations were noted in the urinary excretion of low molecular weight proteins (beta 2-microglobulin, retinol binding protein) and albuminuria. However, total proteinuria and aminoaciduria in persons living in Pribram area was significantly higher. This area suffers from combined contamination by cadmium and lead. In smokers of both sexes the Cd-B levels were significantly higher in all areas, no significant differences were found in Cd-U levels. However, it was found that in smokers there is higher percentage of persons excreting more than 0.9 micrograms Cd.g-1 creatinine in urine. Consumption of home-grown vegetable and fruit in Cd-polluted areas led to significantly higher levels of Cd-B and Cd-U and total proteinuria. The results of the study show that smoking and food seem to be the most important sources of Cd intake in non-occupationally exposed populations. In spite of the fact that environmental monitoring does not reveal a significant contamination of selected areas by Cd, Cd-U levels confirmed that population living in these areas is really exposed to Cd.


Correlation between polycyclic aromatic hydrocarbons concentration and airborne particle mutagenicity in the rubber factory.

The study was undertaken to evaluate the correlation between benzo[a]pyrene and coal tar pitch volatiles concentrations and mutagenic activity of airborne particles sampled at different workplaces of the factory producing various types of tires. The solid phase of aerosols was collected on Whatman glass-fibers filters using Staplex pumps. Coal tar pitch volatiles (CTPVs) were extracted from sample filters using ultrasonic-benzene extraction and determined by the gravimetric method. Benzo[a]pyrene (BaP) analysis was performed using high performance liquid chromatography with a spectrofluorimetric detector. The mutagenic substances were extracted from collected material with acetone. The mutagenic properties were estimated with the Ames' test using S. typhimurium strain TA98 without and with S9 fraction. At nearly all workplaces the concentrations of BaP and CTPVs were within the range of 4-61 ng/m3 and 0.11-1.26 mg/m3, respectively. Only at weighing were they much higher and amounted to 172-2261 ng/m3 for BaP and 3.05-4.07 mg/m3 for CTPVs. The highest exposure to mutagenic airborne particulate matter was found at weighing (1500 rev/m3), the mixers loading level (> 500 rev/m3) and the carbon black station (> 150 rev/m3). The air mutagenic activity at other workplaces, especially at the extruder mill of the mixer (> 90 rev/m3), the two-roll mill of mixers (> 70 rev/m3), mixer I loading (> 70 rev/m3), calendering (> 70 rev/m3) and fender vulcanizing (> 80 rev/m3) was even much more higher than that found in the urban indoor and outdoor air (2-9 rev/m3).(ABSTRACT TRUNCATED AT 250 WORDS)


Urine mutagenicity in workers directly employed in coke production.

Mutagenicity and toxicity of urine samples of 30 coke oven workers (group I) and 26 individuals composing a control group (group II) was estimated using Ames test with Salmonella typhimurium strains TA 98 and TA 100. Urine mutagenicity and toxicity, tested with strain TA 98 and metabolic activation, was significantly higher in group I than in group II. Using the strain TA 100, urine samples of coke oven workers showed only direct toxicity. Mutagenic and toxic activity was observed mostly in workers exposed to the highest BaP concentrations. No correlation was found between obtained results and tobacco smoking. Increased urinary mutagenic activity in group I resulted from exposure to very high BaP concentrations. It is concluded that urine samples of exposed coke oven workers should be periodically tested for mutagenic activity. Workers with mutagenic urine ought to be shifted to work posts with lower exposure to mutagens.


Duration of anesthesia using the periodontal ligament injection: a comparison of bupivacaine to lidocaine.

The purpose of this study was to compare the duration of pulpal anesthesia obtained with 0.5% bupivacaine HCl with 1:200,000 epinephrine to 2% lidocaine HCl with 1:100,000 epinephrine, using the periodontal ligament (PDL) injection. Twenty-four subjects received bilateral PDL injections using mandibular premolar teeth and a double-blind research design. Anesthesia was defined as no response to maximum output of an electric pulp tester. An overall success rate of 35.4% was achieved. Duration of anesthesia obtained with bupivacaine HCl ranged from 4 minutes 59 seconds to 16 minutes 37 seconds with a mean duration of 10 minutes 24 seconds. Excluding one instance in which the duration was three orders of magnitude beyond the norm, duration of anesthesia obtained with lidocaine HCl ranged from 1 minute 43 seconds to 16 minutes 16 seconds with a mean duration of 7 minutes 10 seconds. Postoperatively, all experimental teeth tested vital with no clinically apparent pulpal or periodontal damage. Some postoperative discomfort was experienced at 16.6% of the injection sites.


A case of coronary artery spasm during oral surgery under general anesthesia.

A case of coronary artery spasm during oral surgery under general anesthesia is reported. The patient, aged 44 years, 160 cm in height, and 55 kg in weight, was scheduled for radical surgery for right maxillary sinusitis and was healthy except for the disease requiring surgery. Just before the start of the surgery, severe and persistent hypotension with tachycardia after local injection of 3% propitocaine with 0.03 IU/mL felypressin (Citanest-Octapressin) was followed by sudden ST elevations in the ECG. Immediate continuous intravenous injection of nitroglycerin was thought to be effective. The patient recovered without any sequelae.


Protocol for studying depth of anesthesia using the spectral edge frequency.

The preliminary results of a multicenter study designed to determine the utility of the processed EEG in combination with heart rate and blood pressure for estimating anesthetic depth are reported. The study is planned to include 1,000 ASA I, II, and III patients undergoing surgery with at least a 60-minute duration of anesthesia. The preliminary results indicate that the use of EEG and clinical signs may provide better control of anesthetic depth. The study design provides ideal conditions for determining whether spectral edge frequency is a useful criterion for management of routine general anesthesia in a typical clinical environment.


Vertex potentials evoked by nociceptive laser stimulation of oral mucosa: a comparison of four stimulation paradigms.

A new method for quantitative assessment of oral mucosal nociception and analgesia has been introduced using vertex potentials elicited by nociceptive argon laser stimuli. Four different stimulation paradigms (long, random, warning, and self-triggered) were compared to determine which technique elicited the most reproducible vertex potentials. A warning stimulation paradigm applied on the tongue and hand elicited vertical potentials with smaller amplitudes, lowest intraindividual coefficient of variation (16.5% and 7.9%, respectively), and highest reproducibility. The latency of the major negative peak was not affected significantly by different stimulation paradigms. The high reproducibility of vertical potentials elicited by the warning stimulation may be ascribed to a standardized psychological state of the subjects.


Tenoxicam for pain relief following third molar surgery.

Tenoxicam is a long-acting nonsteroidal anti-inflammatory agent that appears to have the ability to control pain of musculoskeletal origin. A double-blind randomized crossover study was designed to determine the efficacy of tenoxicam for pain relief following third molar surgery by comparing it with paracetamol. Immediately before surgery, 30 Chinese patients with bilateral symmetrically impacted mandibular third molars were given 40 mg of tenoxicam for surgery on one side and 1,000 mg of paracetamol for surgery on the other. Both paracetamol and tenoxicam were efficient as pain relievers after third molar surgery. Tenoxicam had comparable efficacy to paracetamol, but did not provide any advantage in terms of duration of action. The discrepancy between the clinical observation and pharmacokinetic prediction may be related to the strong serum binding property of tenoxicam.


Analysis of abnormal electrocardiogram observed during surgery: Part 1. Lead placement methods and artifacts.

The fundamentals of electrocardiographic diagnosis and the types of abnormal ECGs frequently found during surgery are described in this two-part article. Part 1 discusses lead placement and artifact recognition. Part 2 will describe arrhythmia and atrial fibrillation and flutter. Clinical situations of each are analyzed.


Education in dental anesthesia in the United Kingdom.

This paper describes the present system of education and training for doctors and dentists providing general anesthesia or conscious sedation for dental treatment in the United Kingdom. The changing pattern of practice in these areas is outlined in the context of a changing medicolegal climate, together with the possibilities for future development.


Spark erosion implant-supported overdentures: clinical and laboratory techniques.

Overdentures can be utilized effectively in treatment plans involving implants. Usually soft tissue support is necessary, which requires a conventional denture base. Implant-supported overdentures do not require conventional denture base extension unless necessitated by functional or esthetic considerations. With fixed-detachable hybrid dentures, flanges can often interfere with home care procedures. Spark erosion overdentures meet the requirements for esthetics, phonetics, retention, and support and also allow accessibility for proper patient oral hygiene. This article reviews the advantages and disadvantages of the spark erosion overdenture and provides guidelines for the fabrication of this type of prosthesis.


Hydroxyapatite coatings in implant dentistry.

Hydroxyapatite coatings have shown promise due to the enhanced integration of osseous tissues to coated implant surfaces. When compared with healing around commercially pure or titanium alloy implant surfaces, hydroxyapatite-coated implants appear to be superior in sites which are compromised in either quantity or quality of bone. In spite of these encouraging findings, the long-term stability of the hydroxyapatite/bone interface has been challenged. Microbiologically, the hydroxyapatite-coated implant surface may be at an increased risk to bacterial plaque. However, after 8 years of clinical utilization, the hydroxyapatite-coated implant surface has not been shown to be predisposed to increased long-term failure. Available research as it pertains to this controversial area of implant dentistry is reviewed.


Externally hexed implants, abutments, and transfer devices: a comprehensive overview.

An extensive overview of dental implant abutments for coronally hexed implants is presented. Abutment technology, indications, and contraindications for abutments are discussed. Various implant designs from 16 commercial manufacturers with over 64 abutment variations and transfer concepts are illustrated.


Evaluation of the interprobe electronic periodontal probe.

The Interprobe is designed to provide measurements of pocket depths and attachment loss. Investigators involved in a clinical study on dental implants being conducted by the Dental Implant Clinical Research Group participated in an in vitro evaluation of the variability of repeated measurements made with the Interprobe. Measurements were made on holes drilled to predetermined depths in metal blocks. Three readings by investigators for each of nine test holes were in agreement 75.2 percent of the time. At least two of three readings were in agreement in 98.1 percent of the attempts. Either two of three or three of three readings were within 0.5 mm of the actual depth of the holes over 99 percent of the time. No correlation was noted for accuracy of measurements with hole depth or present clinical duties of the investigators. Although slight initial improvement in measurement accuracy was observed, it was not statistically significant in time over the three measurement sequence.


Issues in bone mechanics related to oral implants.

The development and maintenance of the dental implant-to-tissue interface is clearly of paramount importance in the determination of clinical success. Yet, the precise mechanism with which bone responds to mechanical load remains unknown. A review of current thought on the performance of cortical and cancellous bone as structural foundations for dental implants is provided, with particular emphasis on the influence of its three-dimensional architecture at the macroscopic level. The mechanical response of bone is reported to depend upon the direction, magnitude, rate, and duration of loading. Quantitative relationships have been established to correlate cancellous bone strength and stiffness to its apparent density. Such data provide useful insights into the modeling/remodeling response of bone tissue, which is arguably the ultimate predictor of implant longevity.


The transmandibular implant: implant reconstruction and rehabilitation for the atrophic mandible.

The transmandibular implant is specifically designed for the reconstruction and rehabilitation of the severely atrophic mandible utilizing an extraoral approach. The unique design and surgical protocol of the transmandibular system have proven to be predictable and successful. The indications, implant design and materials, surgical technique, advantages, and disadvantages of the transmandibular system are presented in this article.


[Double-circle-incision for reduction mammaplasty].

The authors have used the double-circle incision for reduction mammoplasty on 55 breasts in 28 patients. The main features of the technique are: 1. Complicated and rigid preoperative markings are substituted by a simple and flexible double-circle incision; 2. Proper dissection between the skin and glandular tissue instead of non-dissection; 3. A conic stump of residual glandular tissue is formed instead of a cylindrical stump; 4. Glandular remodelling is substituted by skin "brassiere" retailoring; 5. The nipple-areola site is determined at the end instead of being the first step of the operation. The clinical results revealed that this new method is suitable for medium or large hypertrophy, especially for young women with good, thick and elastic skin, but it is not suitable for macromastia or severe breast ptosis.


[A preliminary study of the fibrous capsules around silicone mammary implants in Chinese women].

Specimens obtained from 17 fibrous capsules around the silicone implants were examined with naked eye, and light and electron microscopy. Immunohistochemical staining with various monoclone antibodies was used. It was demonstrated that the main infiltrating cells in the fibrous capsules were mononuclear cells, denoting a rejection reaction. Fibrous tissue was formed to separate the prosthesis from the normal tissue.


[The pH value of granulating wound and skin graft in burn patients].

The relationship between pH of granulation of burn wound and take rate of skin graft was presented. The bacteria in the granulation tissue were also quantified. The results showed: (1) The optimal pH of granulation wound for the take of skin graft is 7.2-7.5; (2) pH of granulation of burn wound is related to quantity and species of bacteria in the granulation tissue. The wound pH is 6.7 or lower when the number of Escherichia coli or Staphylococcus aureus is over 10(7)/gm of granulation tissue. The wound pH is 8.0 when the number of Pseudomonas aeruginosa is 10(8)/gm of granulation tissue. Because the measurement of wound pH is rapid, simple and noninvasive, it might be useful in predicting the take rate of skin graft.


[Clinical observation of face peeling treatment for ephelides and phenol excretion in urine].

Since 1986, 710 patients with freckles were hospitalized, and the effects of face peeling were studied. Before treatment, blood and urine routines and hepatic and renal function tests were performed in every patient. Comparisons have been made between the hepatic and renal functions before and after treatment in 100 patients. ECG was performed in all the patients before treatment, and 20 of them have been monitored continuously with ECG after treatment. Comparison of 24h urinary phenol excretion before and after treatment were made in 27 patients. In 5 patients it was showed that the amount of urine phenol declined rapidly with the time. The treatment was effective in 100% of the patients. The cure rate was 84.2%. We concluded that the treatment is an effective and safe method for ephelides in healthy persons.


[Changes in expression of interleukin-2 and interleukin-2 receptor in lymphocytes in patients with burns].

IL-2 mainly combines with the IL-2R on the membrane of the lymphocyte, both to promote activation and proliferation. The expression of IL-2 and IL-2R on the lymphocyte was found to be significantly depressed after burn injury. IL-2 was decreased by 40%-60%, and the expression of IL-2R was decreased by 25%-55%, especially on the 7th day after burn. The results demonstrated that burn injury not only influenced the production of IL-2 from T helper cell, but also depressed the expression of IL-2R.


[Plastic surgery of pseudo-hermaphroditism].

The paper introduced the method of plastic surgery for pseudo-hermaphroditism in 8 patients. Which sex would the patient be finally in should only be determined by the desire of the patient and the patient's family. The results were satisfactory. The technique and problems involved in the operative procedure are discussed.


[Implantation of sensory nerve into flap: an experimental study and clinical application].

Experimental implantation of sensory nerve into flaps was done, with the purpose of restoration of sensation of the flaps. A scanty amount of nerve endings were found in the vicinity of the implantation after 2 months, obvious regeneration was observed after 3 months, and never endings similar to normal after 4 months. Sensory nerve was implanted into flaps in the hands and feet of 25 patients. 1-2 year follow-up showed that pain, temperature and tactile sensations recovered to normal, and two-point discrimination was 11-22 mm in the hands and 35-40 mm in the feet. In 3 patients, the implanted nerves were blocked with procaine, and anesthesia of the flaps ensued, thus it was proved that the flaps were innervated by the implanted sensory nerves.


[Changes in plasma immunologic reactive beta-endorphin and their effect on lymphocyte response to phytohemagglutinin after thermal injury].

The study of immunosuppression after thermal injury has aroused great interest. The present study is an investigation of changes of plasma ir-beta EP in patients and their effect on lymphocyte responses to PHA following thermal injury, in order to establish a relationship between the immune and neuroendocrine system. Plasma ir-beta EP in eighteen burn patients was determined using the radioimmunoassay. At the same time, autoplasma and the autoplasma treated with anti-beta EP serum had been both tested for their effect on lymphocyte responses to PHA. The levels of plasma ir-beta EP were found to be elevated significantly in every phases during the first three days postburn (P < 0.0005-P < 0.001), and then declined to the normal level on the fourth or fifth day postburn. The lymphocytes cultured with autoplasma showed their inhibited responses to PHA during the first three days postburn and returned to normal on the fourth or fifth day postburn, while the autoplasma treated with anti-beta EP serum had an effect to improve the lymphocyte responses to PHA. The findings suggest that burn stress is a strong stimulation which may elevate plasma ir-beta EP and which in turn decrease the lymphocyte response to PHA. We assume that increased plasma ir-beta EP may be one of the main causes of immunosuppression after thermal injury.


[Profuse hemorrhage from the axillary artery in electric burn: prevention and treatment].

A total of 53 cases of electric burns were admitted to our unit during the 1977-1985 period. In 19 cases an upper limb was involved, accounting 35.8 percent of the total. In 15 cases disarticulation of the shoulder was done, and in 3 of them a profuse hemorrhage from the axillary artery occurred as a result of infection of the amputation stumps. The second segment of the axillary artery was ligated during the amputations in the other 4 cases, no hemorrhage occurred in them.


[Experimental study on the reconstruction of vascular links between a pedicle skin flap with preserved subcutaneous vascular network and its implanting bed].

A comparative study of skin flap with a preserved subcutaneous vascular network and conventional skin flap was undertaken in rats with determination of skin temperature, laser Doppler, ink perfusion, microangiography and transparent specimen technics. It was found that all the skin flaps with a preserved subcutaneous vascular network survived after transplantation. Three hours postoperation, the flap microcirculation was poorest (LDF, 28% of the preoperative value). Six hours postoperation, it began to augment, and microvessels containing ink could be seen under microscope at 24 hours, as compared to 3 days postoperation in the controls. On the fifth day, LDF returned to the preoperative level, and the diameter and density of reformed microvessels were similar to the vessels of the adjacent skin. This phenomenon only occurred on the 7th day in the controls. After division of the pedicle on the fifth day, all the flaps survived, while the controls showed partial necrosis. The results indicate that skin flaps with a preserved subcutaneous vascular network can survive on the blood flow of pedicle in the early stage, at 24 hours postoperation flap microvessels begin to reform, and on the fifth day flaps can survive on the reformed microcirculation in spite of the severance of the pedicle.


[Prevention of reperfusion injury of an ischemic flap: an experimental study].

Oxygen-derived free radicals are important mediators of tissue injury in experimental island skin flaps that have been subjected to prolonged ischemia (vascular occlusion) followed by reperfusion. In this study, the role of oxygen free radical scavenger, SOD, and a herb, salvia miltiorrhiza, in the protection of cellular damages during total ischemia and reperfusion was study in the epigastric island skin flaps in experimental rats with electron microscopy and the assessment of survival of the flaps. Control flaps subjected to 10 hours of total vascular occlusion showed a high incidence of necrosis when followed for 7 days following release of the vascular occlusion. Treatment with superoxide dismutase and salvia miltiorrhiza prior to the onset of reperfusion significantly enhanced island flap survival to 72.5% (P < 0.001) and to 64.2% (P < 0.05), respectively. The conclusions are: 1. Reperfusion for 10 hours following ischemia for 8 hours in the epigastric island flaps of the rats greatly exaggerated the original injury. 2. SOD and salvia miltiorrhiza may protect the flaps from such injury considerably and enhanced flap survival.


[Quantitative assay of p-nitrophenol-N-acetyl-beta-D-glucosaminide in human keratinocyte culture].

Attachment and growth of human epidermal keratinocyte culture can be assayed by counting cells or measuring incorporation of radioactive nucleotides (3H-TdR) during cell proliferation. In this study a rapid colorimetric assay for human epidermal keratinocyte growth and viability has been developed based on the colour reaction of NAG (p-nitrophenol-N-acetyl-beta-D-glucosaminide). The results can be read on a scanning multiwell spectrophotometer and show a high degree of precision. The data of experiments show that the absorbance (OD) is directly proportional to the number of cells. 10(3)-10(6) cells per well (1.5 cm2) can be assayed by controlling the time of colour reaction. This method was used to measure keratinocyte proliferation in different culture systems of different culture conditions, growth factor and keratinocyte growth-promoting activity stimulations. The results were supported by counting cells, measuring of 3H-TdR incorporation, or analysing the area of keratinocyte confluents stained with Rhodanile blue. The main advantages of the colorimetric assay are its rapidity and precision, the avoidance of any radioisotope, and it is capable of handling large numbers of culture.


[Glucocorticoid receptor (GCR) in canine peripheral lymphocyte during early postburn period].

In this report, using the radio-ligand binding assay with [3H]-dexamethasone (Dex) as the ligand, we studied the changes in glucocorticoid receptor (GCR) in canine peripheral lymphocyte under unstressed condition and during the early postburn period (within 48 hours after burn). The results showed that the apparent binding capacity (Ro) and the apparent dissociation constant (Kd) of GCR were 8468 +/- 993 sites per cell and 10.2 +/- 0.6 nM (n = 6), respectively, under unstressed condition. The number of [3H]-Dex specific binding sites measured by the single saturated analysis (Rs) from 16 healthy mongrel dogs under unstressed condition was 4531 +/- 396 sites per cell. The Rs was decreased sharply at the second post-burn hour, reaching the lowest level of 2501 +/- 460 sites per cell. But it recovered to 78.9% of the level measured in unstressed condition. There was significant negative relationship between the plasma cortisol concentration and GCR levels of lymphocyte. The results suggest that the changes in GCR in postburn period may be related to the down-regulation of GCR by Gc; that GCR may be of very important significance in the pathophysiologic changes after burn injury.


[Modification of the sympatho-vagal interaction in mitral valve prolapse syndrome. Evaluation of heart rate variability by spectrum analysis].

To determine whether clinical manifestations in patients with mitral valve prolapse (MVP) are associated with altered sympatho-vagal tone, 46 patients (mean age 27 +/- 6, range 20-45 years; 18 males and 28 females) were studied by power spectrum analysis of RR variability. Patients were divided in 2 groups, according to echocardiographic criteria: Group A: 11 patients with classical MVP; Group B: 35 patients with non classical MVP. These patients were compared with 30 healthy subjects (Group C) well matched for age, body surface area and heart rate. Our findings indicate that at rest there is a significant difference in the high-frequency component between Group A and Group C. Similarly, during the increase in sympathetic activity induced by 70 degrees head-up tilt all groups showed an increase in the low-frequency component, that was more evident in Group A. The data generated from our laboratory suggest that mitral regurgitation (Group A) is a probable cause of vagal tone increase and that there is an adaptive long-term mechanism towards sympathetic conditions. In addition, probably the normalization, demonstrable by the effect of sympathetic activity in tilt, can mask a dysfunction that may be differently evoked.


[Evaluation of the therapeutic efficacy of pravastatin in monothereapy and in association with gemfibrozil in hypercholesterolemia associated with moderate hyperglyceridemia].

Pravastatin is a new drug that inhibits 3-hydroxy-3-methylglutaryl-coenzyme A reductase, the key enzyme in cholesterol synthesis. It prevents mevalonate synthesis, thus reducing cholesterol. Pravastatin also stimulates the expression of LDL receptors, leading to an activation of this specific pathway of LDL catabolism. Gemfibrozil is a fibrate drug. Although the mechanism of hypolipidemic action of fibrates is not conclusively elucidated, it seems to involve reduction of LDL cholesterol secondary to decreased VLDL production and increased VLDL catabolism. Therefore, it might be hypothesized that combination therapy with both agents could afford greater reduction of cholesterol levels as compared to pravastatin alone. This study compared the efficacy and safety of pravastatin in monotherapy or in combination with gemfibrozil in the treatment of primary hypercholesterolemia with moderate hypertriglyceridemia. Thirty-eight subjects (aged 57 +/- 15 years, 25 M and 13 F) with baseline cholesterol levels > 220 mg/dl, were included in the study. Serum triglyceride levels were greater than 170 mg/dl and lower than 250 mg/dl. All patients initially followed 4 weeks of hypolipidemic diet. The patients were there assigned to receive either 20 mg once a day of pravastatin alone (n 13) or 20 mg of pravastatin in association with 600 mg of gemfibrozil daily (n 11). Fourteen additional patient, treated with diet only, served as a control group. The treatment plan provided 18 months of active treatment with clinical and laboratory controls every month. Both groups of treated patients showed a reduction of total and LDL-cholesterol levels. The HDL-cholesterol levels increased significantly both with pravastatin and with gemfibrozil.(ABSTRACT TRUNCATED AT 250 WORDS)


[Slow and fast AV nodal pathways in tachycardia complicating Wolff-Parkinson-White syndrome: report of a case].

Electrophysiologic studies in a patient with intermittent ventricular pre-excitation revealed several types of paroxysmal narrow-QRS tachycardia (PSVT). One type of PSVT was characterized by normal retrograde atrial sequences with P waves occurring simultaneously with QRS. This type of PSVT reflected AV nodal reentry with anterograde slow pathway and retrograde fast pathway conduction. A second PSVT reflected alternation of anterograde fast and slow AV nodal pathway conduction and retrograde anomalous pathway conduction. A third PSVT reflected anterograde slow AV nodal pathway and retrograde anomalous pathway conduction. Moreover, discontinuous AV nodal conduction curves (A1A2/H1H2), characteristic of dual AV nodal pathway conduction, were obtained with programmed atrial extra stimulation. These observations suggest that dual AV nodal pathway conduction can coexist with abnormal bypass tract and can be the cause of PSVT in patients with Wolff-Parkinson-White syndrome.


[The role of mitral regurgitation in the neurovegetative regulation of mitral valve prolapse].

To define the role of mitral regurgitation (MR) on sympatho-vagal balance in mitral valve prolapse (MVP) patients, we analyzed 41 ambulatory MVP symptomatic patients. Twenty-seven patients (4 males, 23 females, aged 34 +/- 3 years) had significative MR assessed color Doppler, while 14 patients (5 males, 9 females, aged 29 +/- 3 years) had no MR; 36 age- and sex-matched subjects were studied as controls (C). Spectral analysis of heart rate variability (HRV) was performed at rest and during sympathetic activation (tilt). In the whole group of MVP patients spectral components did not differ significantly from C at rest and during tilt. When patients were subdivided in relation to the presence (+) or absence (-) of MR, HRV revealed in MR+ patients at rest an increased high frequency (HF) and a diminished low frequency (LF) component (47 +/- 5 and 41 +/- 5 normalized units, nu) with respect to C (34 +/- 3 and 54 +/- 3 nu, p < 0.05, respectively). Viceversa during tilt, in MR+ patients it was possible to observe a LF increase greater than in C (delta LF: 36 +/- 4 versus 25 +/- 3 nu, p < 0.05). As HF component is currently interpreted as a marker of vagal modulation of HRV, our results suggest an increased vagal tone associated with MR possibly due to stimulation of atrial vagal receptors; moreover, an increased sympathetic responsiveness to tilt seems to characterize MR+ patients.


[Analysis of regional kinetics of the left ventricle by integration of morphologic data].

Regional left ventricular (LV) curvature analysis is a useful tool to assess the pathomorphological changes in LV shape which occur in different heart diseases. As LV shape changes follow regular trajectories, we used the curvature extrema and the normalized curvature variations as the features for identifying the movement of the borders during the cardiac cycle (curvature-motion method: CM). The regional curvature was calculated using a windowed Fourier series approximation of contours, in which the number of harmonics and filter-window were locally chosen in order to minimize the reconstruction errors and to maximize the smoothness of the curve. Analysis programs were tested on a series of ventricle-shaped contours, software generated. Left ventricular diastolic and systolic outlines obtained from RAO 30 degrees LV angiography in 24 patients with aortic insufficiency and in 16 subjects without heart disease were analyzed. Left ventricular curvature and regional wall motion were calculated in each subject. In respect to normal subjects, LV shape in aortic regurgitation definitely appears asymmetric because of the elongation of the anterior hemiperimeter and the prevailing expansion of the apical and anterolateral regions. These alterations in cavity geometry correlate to the decrease in pump function. According to these results wall motion analysis using the CM showed a greater extension of LV asynergy, while usual methods as the centerline or the radial one indicate a greater damage of the apical regions. Thus, the CM method seems to be a promising tool for wall motion analysis.


Evaluation of regression of left ventricular hypertrophy in hypertensive patients treated with captopril as assessed by magnetic resonance imaging.

Magnetic resonance imaging (MRI) was used to assess left ventricular mass (LVM) in 20 mild to moderate essential hypertensive patients with left ventricular hypertrophy (LVH) (LVM > 120 g/m2), treated with captopril alone or combined with hydrochlorothiazide. MRI examination was performed at the beginning (T0) and after 3 months (T3) of active treatment, by using a Philips Gyroscan S15 superconducting system, operating at 1.5 Tesla. We used a multislice-multiphase spin-echo sequence on the short-axis and transverse plane (TE = 30 ms; TR = 80-90% RR). End-diastolic thickness of interventricular septum (IVST) and lateral wall (LWT) were measured. LVM was calculated according to Simpson's rule. The results were: IVST 12.2 mm +/- 0.7 vs 10.9 mm +/- 0.5 (p < 0.001); LWT 11.5 mm +/- 0.9 vs 10.5 mm +/- 0.9 (p < 0.001); LVM 160 (g/m2) +/- 5.5 vs 138.4 g/m2 +/- 6 (p < 0.001), at T0 and T3, respectively. Our study demonstrates a significant regression of LVH in hypertensive patients after 3 months of treatment with captopril and a high accuracy of MRI as a noninvasive technique of measuring the LVM reduction.


[Regional coronary blood flow in patients with acute myocardial infarct treated by systemic fibrinolysis].

Thrombolysis has been reported to restore coronary blood flow in patients with acute myocardial infarction (AMI). However, the relationship between fibrinolytic treatment and evidence of myocardial reperfusion has not been adequately assessed. Accordingly, we measured great cardiac vein blood flow (GCVF:thermodilution) in 12 patients (Group 1) presenting with AMI (chest pain < 4 hours and ST elevation in the anterior leads) before and following i.v. urokinase (UK:2 million U/90 min). Ten patients receiving conventional treatment served as controls (Group 2). UK induced a significant increase of GCVF (from 101 +/- 24 to 164 +/- 42 ml/min, p < 0.001). Maximal increase occurred after 50 +/- 54 min from drug infusion. Conversely, changes in GCVF were not significant in Group 2 (from 103 +/- 35 to 106 +/- 31 ml/min, NS). Following 24 hours changes in GCVF were still consistent only in Group 1 patients. Individual analysis during 24 hours showed marked fluctuations of GCVF peak values in Group 1 patients (62 +/- 43%), but not in Group 2 (29 +/- 21%). Thus, UK induces a marked increase of GCVF in most patients with anterior AMI; such increase suggests that reperfusion occurs early (i.e. within 1 hour) from UK administration. Fluctuations of GCVF during monitoring are magnified by thrombolysis, suggesting intermittent coronary reocclusion in the early hours of AMI.


[Assessment of perioperative myocardial damage based on circulating heavy chain myosin fragments].

To evaluate myocardial damage induced by coronary bypass surgery, to construct a reference data set in postoperative patients and to ascertain the impact of perioperative myocardial infarction on myosin release from sarcolemmal membrane we serially measured levels of serum fragments of myosin heavy chains by means of monoclonal antibody immunoradiometric assay (MYOSIN IRMA ERIA Pasteur). After surgery serum levels of myosin increased from third postoperative day and peaked on seventh day. Peak myosin levels did correlate with enzymatic activities of CPK (r = 0.69; p < 0.001) and of CPK-MB (r = 0.75; p < 0.001). Six patients suffered postoperative myocardial infarction: in these patients myosin levels were significantly different from those without infarctions (3651 +/- 1569 versus 699 +/- 206 ng/ml; p < 0.01). No correlation could be demonstrated between cardiopulmonary bypass time or aortic cross clamp duration. The rise of myosin levels observed in nearly all patients suggests a minor intraoperative damage to the contractile apparatus that sometimes is diagnosed as myocardial infarction and often does not meet clinical diagnostic criteria.


[Calcium channel blockers inhibit human low-density lipoprotein peroxidation induced by oxygen free radicals in vitro].

Previous studies have shown that calcium-antagonists may reduce the development of experimental atherosclerosis, and that nifedipine may slow progression of coronary atherosclerosis in man. The mechanisms responsible for this effect are still unclear. It has been recently proposed that oxygen-free radicals can induce peroxidation of human low-density lipoproteins (LDL), and that peroxidized LDL may be an atherogenic stimulus. Chemical modified LDL are internalized by macrophages via specific cell surface receptor that was termed the scavenger receptor, and could induce foam cells transformation in vivo. Previous studies on other systems have shown that calcium-antagonists may effectively inhibit oxygen radical-induced lipid peroxidation. These drugs, though differing widely in their chemical structure, are lipophilic to various degrees and presumably would concentrate in the lipid domain of the phospholipid-rich membranes. Therefore, the aim of the present study was to investigate whether calcium-channel blockers may reduce human LDL peroxidation. Purified human LDL were exposed to oxygen radicals generated by xanthine-xanthine oxidase (18 hours) after a pre-incubation (30 min) in presence of different concentrations of nifedipine, diltiazem and verapamil. Peroxidation was measured from malonyldialdehyde production. The results show that calcium-antagonists prevent LDL peroxidation. Thus, calcium-antagonists may reduce peroxidation of human LDL in vitro, at clinically relevant concentrations. These data suggest that reduced formation of atherogenic peroxidized LDL may be an additional mechanism for the anti-atherosclerotic effects of calcium-antagonists in vivo.


[Variations in neuropeptide Y plasma levels in acute myocardial infarction].

The aim of the study was to measure plasma neuropeptide Y (NPY) in patients with acute myocardial infarction (AMI). Eighteen patients (13 females and 5 males; range 55 to 75 years) admitted both early (n 12; mean preadmission time 3 +/- 2 hours) and late (n 6; mean preadmission time 25 +/- 16 hours) to Coronary Care Unit were studied. Plasma NPY values significantly above normal range (15-25 pg/ml) and early admitted patients (26 +/- 10 pg/ml) have been found in late admitted patients (72 +/- 28 pg/ml; p < 0.05) both on the admission and during the stay in the Coronary Care Unit (96 hours). In early admitted patients no significant correlation was found between both AMI localization and the thrombolytic treatment. A significant increase in plasma NPY levels has been observed in all patients with complicated myocardial infarction (both in subclinic and clinic heart failure or extension of infarct size). According with the literature data our results have shown a significant correlation between increase of plasma NPY levels and failure of myocardial pump. Moreover, the plasma NPY increase which has been observed in preclinic heart failure when plasma catecholamine levels is usually not significantly different from normal values, may be a useful and reliable prognostic marker.


[Neuropeptide Y and heart failure].

A time course (48 hours) of plasma neuropeptide Y (NPY) levels has been carried out in a male, 66 years old, admitted to Coronary Care Unit with inferior acute myocardial infarction within 1 hour from the onset of chest pain. On admission an increase of plasma NPY levels (38 pg/ml) has been observed. The plasma NPY value decreased to normal range (15-25 pg/ml) within 12 hours and increased again (53 pg/ml) within 12 and 24 hours. A decrease in plasma NPY values to normal range has been observed within the second day in the Coronary Care Unit. A clearcut diuresis decrease, without pulmonary signs of heart failure, was present from 12 to 24 hours followed by marked polyuria within the second day. These data point out a relative importance of NPY in the diuresis adjustments. Thus, plasma NPY measurement might be a more reliable prognostic indicator of heart failure than plasma catecholamine levels. However, further investigations have to be performed.


Serum fructosamine: a parameter for monitoring metabolic control in diabetes.

The aim of this study was to determine serum fructosamine in a non-diabetic population and to evaluate the usefulness of fructosamine in the routine management of diabetic patients. The range of serum fructosamine in the non-diabetic population was 2.00-3.08 mmol/l (n = 300, mean 2.54 +/- 0.27). The mean level of fructosamine in the diabetic patients was 5.4 +/- 1.1 mmol/l at the beginning of the study and 3.5 +/- 0.4 mmol on the 12th week visit of the study. Significant differences in serum fructosamine levels were observed during the first visit and the 12th week visit p < 0.002. Serum fructosamine concentrations were significantly correlated with glycosylated haemoglobin at each subsequent visit (p < 0.001). No significant correlation between plasma glucose and fructosamine was found, suggesting the two parameters are markets for different time metabolic control. Routine use of serum fructosamine in management of diabetes is recommend.


Aplastic anaemia: a review of cases at the University College Hospital, Ibadan, Nigeria.

Thirty male and 27 female patients were treated at the University College Hospital, Ibadan, over a 20 year period (January, 1971 to December, 1990) for aplastic anaemia. Age range was three months to 52 years with a median of 19 years. In 26 patients the aplasia could not be linked with a particular cause. Most patients in this category were students in secondary and tertiary institutions, office workers and casual labourers. Nineteen patients were automobile and factory workers who are exposed to lead while two were dealers in petroleum products. In two patients aplasia was linked to chloramphenicol ingestion while in three, the aplasia linked to the use of hair dye. Another three linked the aplasia to a past history of viral hepatitis. One patient had congenital aplasia of the marrow and one was a radiographer. Treatment included oxymethalone 100 mg given three times daily (tds) or intramuscular (i.m.) Durabolin 500 mg weekly. When these drugs were unavailable prednisolone 60 mg daily was administered. No patient had the benefit of bone marrow transplantation (BMT) or the superior drugs, e.g. anti-thymocyte globulin and cyclosporin A. This might have contributed to the poor prognosis as revealed by the survival pattern in which 24 patients died within six months of diagnosis while 19 survived 12 months. Seven patients died within 18 months and four others died within three years. Three patients were alive five years after presentation. Death generally resulted from complications of the aplastic anaemia with gastro-intestinal bleeding, cerebro-vascular accidents and overwhelming infections.


The challenges of ambiguous genitalia.

In this paper, we assessed 71 patients between January 1985 and December 1990. Patients with ambiguous genitalia who were seen in the out-patient clinics of both the Paediatric and Urology Departments in the Harare Group of Hospitals. The majority of patients were seen by both the paediatricians and the urologists as children with anomalous genitalia, and a good number were referred to the Urological out-patients as cases of severe perineal, penoscrotal hypospadias, or cryptorchidism. Generally, there were three categories of patients who were seen. The first group were patients referred with severe hypospadias, perineal or penoscrotal and who only, after chromosomal studies, were then categorised into the ambiguous genitalia group. These patients were sent for chromosomal studies because of the concomitant cryptorchidism or, as they were suspected of having ambiguous genitalia because of the well developed labial folds without palpable testes. The second group of patients were patients seen at birth with incongruities which typify ambiguous genitalia. The third group was those who attended the urology clinics with a wish of having surgery performed to render their "phallic organ" long or good enough to help achieve rigidity for sexual intercourse. In the 71 patients seen, the classification had been made and surgery performed on a great majority of them at an early stage, to avoid later catastrophes and the possibility of the development of gonadoblastoma.


Reproductive knowledge, and contraceptive awareness and practice among secondary school pupils in Bagamoyo and Dar-es-Salaam, Tanzania.

Reproductive knowledge, and contraceptive awareness and practice were assessed among secondary school pupils in Bagamoyo and Dar-es-Salaam, Tanzania. Four classes from four government secondary schools were randomly selected within strata of year of schooling, and students were interviewed using a structured questionnaire. All 490 pupils in selected classes participated in the study. Of 481 respondents with complete data, 315 (65.5 pc) were males and 166 (34.5 pc) were females; 256 (53.2 pc) were from Dar-es-Salaam while 225 (46.8 pc) were from Bagamoyo. Two hundred and ninety three (60.9 pc) respondents reported they were sexually active. However, only 77 (17.0 pc) pupils knew the "safe period" within the menstrual cycle and 329 (68.4 pc) pupils were able to spontaneously mention at least one method of contraception. Less contraceptive awareness was noted among respondents below 18 years of age particularly among females in both study areas. Only 45 (15.4 pc) pupils had ever used a contraceptive method. Despite a reasonable level of awareness and a positive attitude towards contraception, only a small proportion of sexually active pupils had ever used contraceptives. More research is required to identify the barriers to contraceptive use in the presence of knowledge.


A clinical assessment of the consequences of alcohol consumption in 'communal' drinkers in the Zimbabwean Midlands.

The study was undertaken to clinically assess the consequences of alcohol consumption in 'communal' drinking patients whose levels of alcohol consumption could not be determined accurately in grams of alcohol. The level of alcohol consumed by 100 adult 'communal' drinking medical patients per drinking session was scored on a scale 0-10. The score was based on a qualitative impression of how much alcohol was drunk, level of consciousness, behaviour and gait. The frequency of drinking days in a week was scored on a 0-7 scale. The duration of drinking in years prior to registration at the clinic was also recorded. The pattern of diseases among the drinkers was compared to that of 70 adult non-drinkers. The individual diseases were ranked to association with alcohol consumption by the Kruskal-Wallis Test. The drinkers attained a mean level score of 5.75 +/- 2.16, a frequency of 4.75 +/- 2.4 days but the duration of prior drinking varied greatly. Gout, dilated cardiomyopathy, epilepsy and hypertension ranked highest in that order to alcohol usage. Rheumatic heart disease and Diabetes mellitus ranked low. The probability significance were, for level score p = 0.005, frequency p = 0.016 and duration p = 0.001. This method was able to identify the morbid chronic medical diseases associated with alcohol usage in 'communal' drinkers. There is a need to evaluate it against a known screening instrument like the Alcohol Use Disorders Identification Test (AUDIT).


Ethnicity, haemostasis and cardiovascular disease: the evidence from Africa.

Disorders of both coagulation and fibrinolysis contribute to the development of cardiovascular diseases such as coronary artery disease, essential hypertension, ischaemic stroke and deep vein thrombosis. Different ethnic groups, in particular Blacks, Whites and Asians have different prevalences for the above diseases. Comparisons of these haemostatic processes in different ethnic groups have contributed greatly to the understanding of the pathogenesis of many of these diseases. Such studies, in particular those conducted in Africa, are reviewed below.


Major hepatic resection for secondary malignant tumours of the liver--case studies from eastern Nigeria.

Major hepatic resection (MHR) was performed in three patients with secondary malignant liver tumour (SMLT). MHR and extirpation of the primary cancer were done synchronously. There were two males and one female age 49, 52 and 65 years respectively. All were in liver functional Class B (Child's). Right hepatectomy and right hemicolectomy were done in one patient; while the others required: (1) left hepatectomy and middle colectomy in one patient; (2) left hepatectomy, middle colectomy total gastrectomy, splenectomy and middle colectomy in continuity in the last patient. They all tolerated the surgery and were discharged 16 to 24 days after surgery. Histology was adenocarcinoma in two patients and carcinoid tumour in one patient. One patient died 14 months after resection from recurrent tumour and liver failure. The other two patients have been followed up for 21 months and nine months. They are well and show no evidence of tumour recurrence. It is concluded that MHR is indicated in selected patients with SMLT. The short term and medium term results are better than the usual palliative management but case selection should be on criteria enunciated below.


Comparing shower-based oral hygiene with traditional and electric toothbrushing.

Despite the importance of self-care for disease prevention, dentists and hygienists have been largely unsuccessful as oral hygiene motivators. Because of competing values, patients commonly fail to comply with prescribed oral hygiene regimens. In this investigation, attitudes of 84 adult dental patients were evaluated following a 30-day trial in which a shower-based oral hygiene system (SBOHS) was compared with manual and electric toothbrushing regimens performed in traditional settings. While attitudinal differences between manual and electric toothbrushing groups were insignificant, the SBOHS was perceived as substantially more enjoyable, convenient and reinforcing than either conventional or electric toothbrushing performed outside the shower. Significantly more SBOHS users reported spending more time on oral self-care, taking better care of their teeth and gums, feeling better about plaque control, appreciating oral hygiene practices more and perceiving cleaner teeth and a fresher mouth after oral hygiene than either the conventional or electric toothbrush users.


Variability of two methods of measuring absorbed dose in dental radiography.

Thermoluminescence dosimetry (TLD) has been widely used in the monitoring of radiation exposure in healthcare workers operating radiation devices. This study compared the reliability of TLD to an electronic dosimeter. The absorbed dose registered by the TLD chips was found to be higher than that by the electronic dosimeter. Variability was found to be significantly higher and the variance component attributed to the variability of the method of measurement was more than twice as much in TLD when compared to the electronic dosimeter. It is concluded that TLD is a more variable method of measuring absorbed dose than the electronic dosimeter.


Indirect pulp capping: a survey.

This study addresses the acceptance of the clinical practice of indirect pulp capping. State and regional dental boards and postgraduate dental education programs throughout the United States were surveyed. Results indicate that no clear consensus exists for the acceptance of this clinical procedure.


In vitro demineralization inhibition of enamel caries utilizing an unfilled resin.

Smooth surface caries remain a concern in children, particularly those that are diagnosed with "baby bottle caries." The purpose of this study was to evaluate the caries inhibition of an unfilled resin placed on smooth enamel surfaces. Incisors were obtained and painted with an acid-protective varnish, excluding 2 mm x 6 mm windows on the labial surface. Each tooth had an unfilled resin placed over half the area of the window; the remaining area was not treated. One hundred microns longitudinal sections were obtained from the treated and non-treated sites. Polarized photomicrographs were taken of each section, in imbibition media of air, water and Thoulet's (R.I.: 1.41, 1.47), representing a minimum of 1%, 5%, 10%, and 25% pore volume respectively. The sections were then painted with an acid-protective varnish so that only the external surface was exposed and placed in separate closed environments of a non-fluoridated artificial saliva. One section from each tooth had unfilled resin on the external surface, one section had only natural enamel exposed, and a third section had the external surface varnished to act as a control. The teeth were thermocycled at 10 degrees C and 50 degrees C, 20 cycles per day for three months; they were also cycled through artificial caries challenge (pH 4.4) for 35 minutes, three times per day. Sections were then photographed under polarized light, as before, and areas of lesions were digitized. Results demonstrated caries to be present on all non-treated enamel surfaces exposed to the artificial caries challenge. Significantly less enamel demineralization occurred when an unfilled resin was placed on it (p < 0.001).


The pH volume changes of human red cells in vitro due to the exchange of chloride and hydroxyl anions.

In glucose exit experiments measured photoelectrically, the excursions on the chart recorder were found to be larger for exits in media of alkaline pH. This was shown to be due to the addition of a pH volume effect to that of the osmotic shrinkage resulting from the glucose efflux. The pH-dependent volume change also occurred in glucose-free cells and was a linear function of the pH of the medium between pH 6.8 and 9.0. The effect is consistent with the loss (or gain) of chloride in exchange for hydroxyl anions on the band 3 anion transporter and with the buffering of the hydroxyl anions by haemoglobin. The implications for the working of the anion exchanger and for respiratory physiology are discussed.


Specific insulin binding by, and imprintability of, the nuclear membrane of Tetrahymena.

Cellular nuclei isolated from Tetrahymena were able to bind FITC-labelled insulin, and pretreatment with different concentrations of unlabelled insulin accounted for a decrease in FITC-insulin binding of the nuclear membrane. This strongly suggests an association of specific insulin receptors with the nuclear envelope of Tetrahymena. Nuclei isolated 1 week after primary exposure of Tetrahymena cells to insulin showed a 50% binding increase over the controls. This supports the implication that hormonal (insulin) imprinting also involves the receptors of the nuclear membrane of the imprinted cells.


Enhancing flossing compliance in college freshmen.

This study examined the relationship between dental compliance and health locus of control in 41 college freshmen. Subjects were randomly assigned to either a control (N = 13) or experimental (N = 28) group. Dental flossing compliance was assessed in all subjects using a brief dental exam that assessed pocket depth and plaque as indexes of flossing behavior. The Multidimensional Health Locus of Control Scale was used to measure health locus of control. An educational, low-fear intervention, consisting of the presentation of a pictorial diagram of the progression of periodontal disease and discussion of the importance of flossing was presented to the experimental subjects before monitoring began. Control subjects underwent a brief dental examination and flossing instruction only. Self-reported flossing compliance was monitored for 24 days following the dental examination and intervention. Significant decreases in the dental exam variables associated with plaque were found for both the experimental and control conditions. The low-fear, educational intervention had no significant impact on compliance. Instead, a dental exam and self-monitoring were as effective at increasing flossing compliance as the more time-consuming educational approach. A significant increase in internality of health locus of control across all subjects was also found. No significant interaction was found between health locus of control and group, but a trend was apparent. Control subjects who were externally oriented had the lowest flossing compliance scores while internal subjects in both conditions had higher flossing compliance scores.


Clinical effect of a triclosan-containing dentifrice on plaque and gingivitis: a six-month study.

A total of 294 adult male and female subjects completed a 6-month, double-blind clinical trial designed to evaluate the effects of a dentifrice which contained 0.3% triclosan in conjunction with 2% of a methoxyethylene/maleic acid copolymer in a 0.243% sodium fluoride/silica base, relative to a control dentifrice, on supragingival plaque accumulation and gingivitis. Plaque and gingivitis were scored after 3 and 6-month use of the assigned dentifrice. At the end of the study, the triclosan group showed an average reduction, relative to the control group, of 12% in plaque accumulation and 20% in gingivitis. Both were statistically significant at p < or = 0.0001. The effect of the triclosan dentifrice was most pronounced on the more severe manifestations of plaque and gingivitis. The improvement in the gingival parameters at 6-months relative to the control dentifrice was statistically significant at p < or = 0.0001. It was concluded that the twice-daily use of the triclosan-containing dentifrice resulted in significant reduction in supragingival plaque formation and a significant improvement in gingival health without the presence of any extrinsic staining or objectionable taste.


Evaluation of the genotoxicity of 4-N-butylamino-1,2,3,4-tetrahydroacridine hydrochloride (centbucridine): a new local anaesthetic.

Centbucridine, a new local anaesthetic, was tested in in vivo genotoxicity assays. Three different endpoints were selected for this purpose. Chromosome aberrations (CA) and sister chromatid exchange (SCE) were analysed in bone marrow cells and DNA-strand breaks (SB) were measured in liver cells of mice following a single acute exposure. No significant differences were observed in the CA, SCE and SB studies, when compared with respective controls. An increase in the mitotic indices (MI) was observed only with the lowest dose tested in the CA study. No significant differences in the MI were observed with the two higher doses tested when compared with solvent controls. Trend tests for linear dose response were negative in all the parameters examined including MI. The overall results of the three endpoints tested indicated that centbucridine was not genotoxic in the mouse.


Survey on AIDS, fear and infection control: attitudes affecting management decisions.

As a result of increased public concern about AIDS and dental treatment, dental professionals need to cope with legislative reactions, increased infection control costs, patient anxiety and vigilance on the part of law enforcement agencies regarding compliance with "universal precautions." Recommendations abound for educating patients about dental office infection control to allay irrational fears and market dental office asepsis, but few studies quantitatively measure these needs or address the behavioral concerns patients have about AIDS infection related to dental care. In this investigation, dental patients were surveyed to determine their beliefs, attitudes and behaviors regarding AIDS and dental office infection control. Several important educational caveats were identified. This paper considers these challenges and provides patient education and practice management recommendations consistent with a preventive focus on allaying dental patients' fears while building more successful dental practices.


Effect of pretreatments (imprinting) with different concentrations of insulin on insulin binding of nuclear envelope and plasma membrane in Tetrahymena.

About 4 h following treatment with 10(-6) - 10(-10) M insulin (imprinting) there was a down-regulation both in the plasma membrane and in the nuclear envelope of Tetrahymena, i.e. there was a decrease in the binding value related to the control. In each concentration tested the imprinting resulted in increased FITC-insulin binding after 24 and 48 h of treatment; the imprinting was independent of the concentrations. In the case of the plasma membrane the power of binding was directly proportional to the increase of the hormone concentration participating in the imprinting. For the nuclear envelope the optimal concentration was 10(-8) M. At very low concentrations (10(-10) M) the binding resulting in imprinting was insignificant in the plasma membrane but it was still present in the nucleus.


Changes in proteolytic susceptibility of human erythrocyte membrane proteins during red blood cell aging.

The method employed facilitated analysis of the digestion of denatured proteins, depleted in their natural membrane environment. The susceptibility of human erythrocyte membrane proteins to digestion with trypsin was studied by the two-dimensional electrophoretic method. Ghosts were isolated from erythrocytes fractionated according to density (age). Spectrin and band 3 protein from membranes isolated from the youngest cells were significantly more slowly degraded than proteins from middle-age cell membranes and from the oldest cells.


[Monitoring of maternal-fetal hepatitis B virus transmission by molecular hybridization technique].

Maternal venous blood (MB), umbilical blood (UB) and placental tissue (PT) were collected from 40 HBsAg positive mothers and their neonates, and also blood from 17 babies aged 3-6 months old of this group (BB). All samples were determined for hepatitis B virus (HBV) DNA by molecular hybridization technique using Bio-HBV DNA probe. The results showed: HBV DNA positive rate of MB was 35.0%, 47.5% for UB, 75.0% for PT and 29.4% for BB. 32 P-HBV DNA probe was also used to examine MB and PT. The positive rates of HBV DNA were 30.0% and 70.0% respectively. There was no significant difference between the results of the 2 probes. We considered: (1) With the rapid development of HBV detection technique, the detectable rate of intrauterine infection increases accordingly. (2) Besides transplacental infection, other transmission routes might be existed. (3) The detection of HBV DNA in UB, PT and in the blood of babies born by HBV DNA positive mother within 6 months old provides the reliable diagnosis. (4) HBV DNA molecular hybridization is an accurate and sensitive method for the diagnosis of HBV intrauterine infection.


[Hemodynamic effects of antihypertensive drugs on pregnancy-induced hypertension].

Aiming to select a proper kind of antihypertensive drug for mild and moderate pregnancy-induced hypertension (PIH), 30 patients with PIH were examined by using noninvasive cardiovascular detector TP-CBS. The basic hemodynamic parameters included mean artery pressure (MAP) Kpa, heart rate (HR) bpm, cardiac index (CI) L min-1/m2 and total peripheral resistance (TPR) PRU. The 30 cases were divided into 6 groups with 5 each to take a single dose of prazoxin, phentolamine, methyldopa, captopril, nifedipine and aminophylline respectively. Hemodynamic parameters were examined consecutively every 30 minutes for 4 hours after ingesting the above drugs. The results showed that all the 6 medicines had effects of lowering MAP and TPR without change of cardiac output. Nevertheless, viewing from the effect of lowering blood pressure, change of pulse rate, time of action and incidence of side effects, we considered that nifedipine is superior to the other 5 and can be preferably recommended at outpatient clinic.