Follicular cystitis in girls with untreated asymptomatic or covert bacteriuria.

Nodular changes of the bladder mucosa, that is cystitis follicularis or cystitis cystica, are found in 2 to 9% of all children with urinary tract infections. The nodules are composed of lymphoid aggregates, resembling Peyer's patches in the intestine. Children with this finding are considered to have a poor short-term prognosis with a marked tendency for recurrent infections. Screening programs for bacteriuria have revealed that a few per cent of the female population are bacteriuric without symptoms of overt disease. Of 59 girls followed with untreated asymptomatic bacteriuria 52 had nodular changes of the bladder mucosa at cystoscopy. Biopsy was performed in 22 girls, and revealed lymphocytic infiltration in 19 and follicular formation in 11. The nodular changes persisted when bacteriuria continued but disappeared in patients who became abacteriuric. This finding demonstrates the reversibility of the changes, and supports the assumption that they are secondary to the presence of bacteria and not a primary lesion.

A filter method for the active and passive monitoring of sulfur dioxide in workplace air.

A method where sulfur dioxide is collected on impregnated filters (glycerol/potassium hydroxide solution) is described. Sampling can be done either with a pump or by the use of two different passive monitors available on the market. Analysis is made by ion chromatography. The methods have been evaluated and compared with a colorimetric air monitoring badge system (ProTek). Laboratory tests show that the accuracy of the filter methods is acceptable and that samples can be stored. Water vapor does not interfere, but hydrogen sulfide causes a minor decrease in recovery. ProTek has high accuracy but storage tends to decrease the recovery. Field tests in a steel rolling mill and a sulfate pulp mill showed a fairly good correspondence between the methods.

Development and evaluation of field methods for ammonia in air.

Three methods for measuring ammonia in air have been evaluated. Filters impregnated with 10% (volume/volume) phosphoric acid in methanol were used for two methods. Sampling was done either with a filter cassette connected to a pump or with the filters placed in a passive monitor (Gasbadge). The filters were leached with distilled water after the sampling and analyzed with ion chromatography or colorimetry (Nessler). The third method tested was a colorimetric air-monitoring badge system (ProTek). The tests showed that the accuracy of the filter methods is good and that the results are not affected by humidity. If ion chromatography is used for the analysis, amines do not interfere. The Gasbadge monitors increased their uptake when the air velocity over the sampler was raised from 0.2 to 1.0 m/s. The accuracy of the ProTek method was poor, the method was biased, and blank samples showed high values. In field tests carried out in a foundry and at a fertilizer plant, the agreement between the filter methods was good, whereas the results of the ProTek method deviated drastically from those of the other methods.

Exposure to xylene and ethylbenzene. III. Effects on central nervous functions.

The effect of exposure to the solvent xylene on performance of tests of numerical ability, reaction time (simple and choice), short-term memory, and critical flicker fusion was studied in two separate laboratory series. In the first series fifteen healthy male subjects were studied individually on three separate occasions with exposure to 435 and 1,300 mg/m3 xylene in inspired air and under control conditions. In a second series eight of the subjects were exposed to 1,300 mg/m3 xylene in inspired air. This exposure period began with 30 min of work on a bicycle ergometer (100 W) and continued during the behavioral tests. The procedure was the same under control conditions. Each exposure period lasted 70 min. At certain times during exposure, samples of the subjects alveolar air were collected. Exposure to xylene did not cause any noticeable change in performance during the first laboratory series, when the subjects' total uptake of xylene was estimated to be on an average 180 and 540 mg, respectively. In the second series the physical work induced an increase in the total uptake up to an average of 1,200 mg. In this series clear evidence of performance decrement was observed in three of the performance tests.

Exposure to butyl alcohol: uptake and distribution in man.

Twelve subjects were exposed to 300 or 600 mg/m3 of butyl alcohol in inspired air during rest and during exercise on a bicycle ergometer. Exposure lasted 2 h. The results were puzzling in view of the high blood/air partition coefficient for butyl alcohol. The arterial blood concentration was low. The concentration in the last part of the expired air, i.e., the ""alveolar'' concentration, was low. The quotient of ""alveolar'' concentration X 100/inspired concentration was low in relation to the low percentage uptake. However the high solubility of butyl alcohol in water may explain the results. Butyl alcohol was probably partially taken up in the water of the dead space mucous membranes during inspiration. It was then partially released from the membranes. Therefore the concentration of butyl alcohol in the last part of expiration was probably not the same as the concentration in the alveolar air.

Exposure to methylene chloride. III. Metabolism of 14C-labelled methylene chloride in rat.

The accumulation of methylene chloride and its metabolites in different organs and tissues was studied in an experimental series comprising 10 rats. Each rat was exposed for 1 h to radioactive methylene chloride (14C) in a concentration amounting to 1,935 mg/m3 in inspiratory air. Radioactive carbon atoms were found in the isolated carbon monoxide after exposure. There was also a close correlation between the activity of carbon monoxide extracted from the blood sample and the amount of carboxyhemoglobin (COHb) in the specimen. The largest concentration of methylene chloride and its metabolites per gram of tissue was found in white adipose tissue. This concentration had declined by more than 90% 2 h after exposure, whereas the concentration in the liver declined by about 25% during the same period. The amount accumulated in the brain displayed a decline of about 75% 2 h after exposure. Thus the examination showed that the increased concentration of COHb in the blood during exposure to methylene chloride is due to the metabolism of methylene chloride into carbon monoxide.

Exposure to methylene chloride. II. Psychological functions.

The effect of the solvent methylene chloride on psychological functions such as reaction time, short-term memory, and numerical ability was studied in 14 healthy male subjects. Each subject was tested repeatedly during exposure to 870, 1,740, 2,600, and 3,470 mg/m3 of methylene choride in inspiratory air and during control conditions. Samples of sub ject alveolar air were taken every third minute during the experiments. No statistically significant impairement in the performance of examined functions could be observed during exposure to methylene choride as compared to control conditions. Inexposure to the highest concentration a greater irregularity of response was obtained for subject reaction time than under control conditions.

Exposure to white spirit. II. Psychological functions.

The effect of the solvent white spirit on psychological functions, such as perceptual speed, reaction time, short-term memory, numerical ability, and manual dexterity, was studied in two separate series of experiments employing 14 and 8 healthy male students, respectively. Each subject was tested repeatedly in each series in exposure to 625, 1,250, 1,875 and 2,500 mg/m3 of white spirit in inspiratory air and under control conditions with exposure to pure air. In another experimental series each subject was tested during exposure to 4,000 mg/m3 of white spirit and under control conditions. Alveolar air samples were taken every fifth minute. No effect on examined functions was observed in the first experimental series. However, a prolonged reaction time and a probably impaired short-term memory was observed in subjects exposed to 4,000 mg/m3. At this concentration of white spirit in inspiratory air an alveolar air concentration was obtaine which corresponded to values obtained in exposure to 2,500 mg/m3 during light exercise.