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Dental caries reduction was studied in 414 children 1 year following F-year primary caries prevention with the use of sodium fluoride solution, fluorine lacquer, and Ca phosphate-containing gels. Essential reduction of the intensity of carious involvement of the teeth was seen in the examinees as against children not administered specific prophylactic treatment.
A simple and rapid method for permanently marking autoradiographs is described. This procedure is based on the phosphorescence of light-activated zinc sulfide and the subsequent exposure of x-ray films by this light emission. A lacquer-based carrier allows the zinc sulfide to remain in suspension and permits permanent marking onto diverse laboratory substrates such as x-ray films, paper, plastic wraps and nitrocellulose- and nylon-based membranes. An analogous wax-based carrier allows marking onto paper and dried acrylamide gels, which is useful for processing large numbers of radioactive DNA sequencing gels on a high-throughput scale. These inexpensive and nonhazardous markers will be useful in protocols that use x-ray films, regardless of whether radioactive or nonradioactive detection systems are used.
The recognition of bronchial asthma as occupational disease is essentially a matter of legislation and not of medical definitions. Swiss law accepts an occupational nature of asthma when its causes derive to more than 50% from the work place. Causes are extremely diverse, whereby in Europe flour (bakers) and isocyanates (spray lacquers) dominate. Together, these causative agents contribute close to 50% of all cases of occupational asthma. The clinical picture is that of classic bronchial asthma. Peculiarities are seen only regarding the temporal dependence between exposition and beginning of airway obstruction. Regarding diagnosis of occupational asthma the following questions should be answered. 1. Is the dyspnea described by the patient real bronchial asthma? 2. Is there a documented temporal connection between exposition and complaints? 3. Is there a causative agent at the work place? Peak-flow measurements are particularly useful for documentation of connection of symptoms with occupation. They demand, however, a certain degree of cooperation by the patient. The prime therapeutic measure is avoidance of further contacts with the responsible agent. The Swiss health authorities (SUVA) have the power to issue decisions of unsuitability for certain workplaces or exposures. Such a measure is however severe and requires therefore a careful diagnosis and an evaluation of risk and benefit for the patient.
A total of 297 children aged 5-7 whose first permanent molars appeared in various periods were followed up. Local prevention of caries was carried out in these children with Soviet fluorine lacquer and sealing of fissures and anatomic hollows in molar masticatory surface. The efficacies of these two prevention methods proved to be different. In children whose first permanent molars appeared early or late fissure closing with vitacryl proved to be effective whereas in those whose molars appeared in time both methods were effective.
Barium chloride, which is an important industrial chemical used in pigments, lacquers, dyes, glass and pesticide production, leather tanning and cloth dying, was tested on Salmonella typhimurium (TA 1535, TA 1537, TA 1538, TA 97, TA 98, TA 100) with the reverse mutation test, with and without metabolic activation, to assess its possible genotoxic effects and any possible action with respect to standard mutagens (sodium azide, 9-aminoacridine, 2-nitrofluorene, mitomycine-C, 2 aminoacridine). Using the platelet incorporation technique, barium chloride at various progressive concentrations gave negative results under the experimental conditions of the study.
Trichloroethylene, an organic solvent from the group of chlorinated hydrocarbons, has been employed throughout the greater part of this century particularly for degreasing of metals, dry cleaning and as a content in glue and lacquer. Biological monitoring of workers exposed to trichloroethylene as current health supervision has been employed in Danish factories since 1947 as the metabolite trichloroacetic acid in the urine provides an indication of the degree of exposure during the preceding week. In the present investigation, a review was undertaken of all measurements of trichloroacetic acid notified to the Danish Labour Inspection Service during the period 1947-1987 in order to obtain an impression of the historical development in the level of exposure. A total of 2,272 biological measurements distributed among 330 factories, reveal exposure of about the same level from the middle of the fifties to the middle of the seventies but with a distinct fall during the period, as the average value during the first five-year period was 82 mg/l as compared with 18 mg/l at the end of this 40-years period. These data are supplemented by case-histories from the earliest part of the period described by doctors from the Danish Labour Inspection Service.
Stomatologic examinations of 1370 children aged 7, 12, and 15, determination of hygienic indexes in them, and anonymous questionnaires distributed among 154 parents and 64 pupils, as well as study of the efficacies of fluorine lacquer and gel have lead the authors to a conclusion that the level of dental caries intensity is low in children, but shows a tendency to growth. This necessitates introduction of a program of measures for the prevention of dental diseases and local administration of fluoride drugs, fluoride gel being the most effective of them.
Enamel blocks of 16mm2 from pre-molars buccal surface, extracted by orthodontics reasons, were prepared for scanning electron microscope study. No treated surfaces displayed the characteristics of normal surface--young, with no defects, presence of perikemata and their pits and depressions. The effects of etching and polishing with abrasive paste were evidenced. Treated samples were enamel blocks demineralized and previously polished; they were given topical application of NaF (pH 4.6); APF (pH 3.2) and NH4F (pH 4.6) by 5 minutes. The control site was protected with nail lacquer to avoid the solution test contact. After treatment the blocks were submitted to KOH extraction, to remove calcium fluoride accumulated on the surfaces. Similar degrees of demineralization were observed, whereas the NH4F treatment have shown a more significant pattern.
The highest rate of inactivation of Staphylococcus aureus (ATCC 6538), Streptococcus faecium (ATCC 6057) and spores of Bacillus subtilis var. niger (DSM 675) was observed at a relative humidity (RH) of 90-95%. At a RH of 60% D 0.75 mg HCHO l-1 air at 45 degrees C-values of 35 min and over 65 min were determined for S. aureus and for B. subtilis spores which decreased to D = 2.9 min and D = 20 min respectively at a RH of 90%. At 45 degrees C, an optimal formaldehyde (HCHO) concentration for the inactivation of S. aureus was within the range of 0.75 to 1.5 mg HCHO l-1 air, with D-values of 2.9 to 1.8 min respectively and for Bacillus subtilis spores from 1.5 to 3.2 mg HCHO l-1 air with D-values of 10.9 to 4.0 min respectively. The most effective bactericidal and sporicidal activity of HCHO was observed at temperatures ranging from 40 to 45 degrees C. The higher the exposure temperature the lower were the HCHO residues on 100 cm2 aluminium plates with a structured lacquer. Exposure to formaldehyde concentrations of 0.4 mg l-1 air for 60 minutes resulted in lower residual formaldehyde of 5.9, 5.6, 4.7 and 4.5 micrograms HCHO 100 cm-2 sample surface at 30, 35, 40 and 45 degrees C, respectively. In contrast, after exposures to 3.2 mg HCHO l-1 air residues of 48.5, 43.4, 35.6 and 30.6 micrograms HCHO 100 cm-2 were found at the same temperatures.
A study is performed on workers from some productions of a Chemical Plant--H-acid, phthalic anhydride, ferrum-oxidate dyes and lacquers, in view of estimating the occupational risk of skin diseases. It is established that the highest occupational risk of skin diseases to which workers are exposed is in the production "H-acid"--25.8%, followed by "Phthalic anhydride"--13.2% and "Ferrum-oxidate dyes"--13%. The epicutaneous test shows positivation of the samples with phthalic-anhydride in 20% of the examined. In those engaged in the production of ferrum-oxidate dyes positive tests are observed in 23.2% of the examined; the highest relative part is taken by the potassium--56.2% and the sodium-bichromate--37.5%. The study of immunoglobulin A, M and G in workers from the lacqueur shop proved the irritating effect of the noxae, and established statistical significant higher values of immunoglobulin "A". The study of some functional investigations--pH and alkaline resistance of the skin give no significant deviations, save single cases. The authors consider the necessity of technological improvement of the production processes in the production "H-acid" where the workers are exposed to the highest occupational risk of skin diseases.
Lacquered aluminium drink cans were filled with deionised water and buffers (pH 1-13) and stored at 20 + 2 degrees C for 60 days. The aluminium content of the solutions contained therein was assayed by atomic absorption spectroscopy at time intervals and the leaching of aluminium from the cans examined. The possible toxicological hazard of the addition of aluminium to the diet from this source is discussed. It is concluded that drinks packaged in aluminium cans do not present a significant risk to people with healthy kidneys.
Twenty-six patients with previous heavy exposure to organic solvents were admitted to a neurological department during a 1 1/2 year period. They were studied with a battery of tests, including general medical and neurological examinations, neuropsychological tests, electroencephalography (EEG) and neurography with electromyography (EMG), and cerebral computerized tomography (CT). The presenting complaints were compatible with encephalopathy and/or polyneuropathy. When patients with alternative diagnosis were excluded, 17 patients (65%) of the initial group were diagnosed as belonging to the organic solvent syndrome. These patients had a mean time of solvent exposure of 23.9 years, ranging from one to 45 years. EEG and cerebral CT showed minor deviations only as did the neurological examination. These methods proved nevertheless of importance in excluding alternative etiologies. Neuropsychological test performances were markedly reduced, especially short-term memory. All patients were injured by occupational exposure to organic solvents, most often from painting and lacquering. Encephalopathy was a more frequent finding than polyneuropathy, and most often classified as slight or marked, whereas severe encephalopathy was not found in the present group.
After a formaldehyde exposition of 100 cm2 aluminium plates covered with a structured lacquer during 60 min at 40 degrees C and relative humidity of about 90% in a model chamber formaldehyde residues of 9.5, 21.9 and 57 micrograms HCHO 100 cm-2 were recorded for plates exposed respectively to 0.75, 1.5 and 3.2 mg HCHO l-1 air. In the model chamber tempered at 40 degrees C the reduction of the HCHO residues after an additional 60 min ventilation with an internal air circulation was 63%. After a passive aeration for 60 min in a room at ambient temperature (24 +/- 3 degrees C) without ventilation the formaldehyde residues decreased by 70-74%. In a heating cabinet tempered at 40 degrees C after an internal active aeration of 60 minutes the residual formaldehyde diminished by 76-82%.
The Fourier-Transform-Infrared spectrometry (FTIR) is a very valuable technique for identifying organic substances. FTIR is more versatile in comparison to disperse infrared spectrometry, as it combines speed and sensitivity. FTIR is even superior to GC/MS: 1. Easy differentiation between isomers is possible. 2. Functional group information can be achieved instead of mass fragments. 3. GC fractions can be saved for further analysis. The FTIR instrument has no prisma or grating. It is equipped with a Michelson interferometer, which gives much more beam energy on the examination object. Most beneficial is the use of a broadband beam source, which impinges simultaneously all frequencies on the sample and on the detector. All these qualities allow the registration of fast chemical and biological processes or the observation of all reactions by volatizing and evaporation at high temperatures. IR spectrometer can run high quality infrared spectra in short time (almost 100/second) with high sensitivity. This is the basic requirement for the "on line" coupling of the IR-system with a GC. The GC peaks are analysed by IR beams with the help of a "light pipe". It is possible to examine all kinds of substances with diffuse and attenuated total reflectance methods. In special cases the change for binding of proteins and kinetic and structural processes in the flowing blood can be measured in vivo. Another use of FTIR-techniques is possible in combination with a microscope. Samples with a square aera of 8 microns can be examined. In criminalistics and forensic toxicology little particles as hairs, fibers, foams, adherents of powder in clothes, splinters of lacquer and paints etc. can be detected and identified by transmission or reflection. In conclusion, the FTIR spectrometry offers a versatility to some measurement problems that is often superior, faster and easier than other techniques such as NMR and MS.
The aim of this paper is to present difficulties in establishing the causal relationship between many years' combined exposure to benzene and other aromatic hydrocarbons and the occurrence of a rare form of leukemia (hairy cell leukemia) in a worker of patients and lacquers factory. Usefulness of experimental and points epidemiologic studies is critically discussed in order to show the consequences of the etiology of combined occupational exposure.
Because the skin is easily available, the combination of frequent periods of critical observation, the dermatologist's clinical experience, and carefully controlled documentation of these observations allow for self-experimentation in dermatologic disorders on the part of clinicians. The practical value of such self-experimentation has been shown over many years, especially by the use of skin surface microscopy at moderate magnification to examine various lesions; to document sensitization experiments with nickel, Japanese lacquer, and nitrogen mustard; to examine prolonged use of topical fungicides for the treatment of onychomycoses; and to contribute to extensive and continuing experiments in laser medicine.
In two caries model experiments on Wistar rats, a significant reduction in caries was observed following local application of Fluorprotektor and Duraphat. There appears to be no difference between the caries-protective properties of these two agents. The accumulation of fluoride in the superficial enamel was tenfold to elevenfold for the two lacquers. Residual Fluorprotektor was found on teeth even after twenty-four days from the application thereto.
A case-reference study was conducted to estimate the association between neuropsychiatric diseases leading to early retirement pensioning and exposure to organic solvents in the Danish wood industry. Cases were defined as all members of the Carpenter/Cabinet Makers' Trade Union who were diagnosed with a neuropsychiatric disease and received disability or early old-age pensions during the period January 1, 1971 to December 31, 1975. The case group comprised 171 disability pensioners and 35 early old-age pensioners. A reference group of equal size was selected among union members with other diseases who were pensioned over the same time-period. Controls were matched to cases according to age and type of pension. Among a total of 412 eligible study subjects, 342 (i.e., 287 disability pensioners and 55 early old-age pensioners) could be located in 1978. Of these, 9.8% of the disability pensioners and 12.7% of the early old-age pensioners did not respond to the questionnaire. Information regarding occupational exposure and vocational training was obtained both directly from study subjects and from the files of the trade union. Medical diagnoses were obtained through registry linkage and by manual search of hospital records. Former employees with high levels of exposure to organic solvents were more likely to receive disability pensions for neuropsychiatric reasons compared to more modestly-exposed individuals. Cabinet-makers and especially cabinet-makers with high exposure to lacquers and glues had a higher risk of receiving a disability pension for a neuropsychiatric disease than carpenters. Possible sources of bias are discussed in the article.