Development and evaluation of an HPLC urinalysis screening test for occupational exposure to 3,4- and 3,5-dichloroanilines.

OBJECTIVE: In order to develop a screening test to detect human occupational exposure to aromatic amines such as 3,4-dichloroaniline (3,4-DCA) and 3,5-dichloroaniline (3,5-DCA), we first investigated the urinary excretion of these highly toxic compounds in the rat. The study was performed after both oral and dermal application, even though contact with the skin is the major route of contamination in the workplace. The aim of this study was to develop a rapid screening test for risk assessment in the workplace. METHODS: An initial group of 3 rats was treated with 40 microl of 3,4-DCA solution (30% in methanol), applied topically to the shaved dorsal skin. A second group of 3 rats were administered the same dose of the amine orally by gavage before urine sampling. The same procedure was performed with 3,5-DCA (2 other groups of 3 rats). The urine samples were collected for a period of 24 hours after treatment and the excretion of 3,4-DCA, 3,5-DCA was studied using a GC-MS and an HPLC method after urine extraction. The urine of 2 workers potentially exposed to the amines for a period of 161 and 147 days, respectively, was analyzed by the same methods with urine collection before and at the end of the work shift. RESULTS: The study of excretion in the rat showed that unchanged dichloroanilines and some metabolites were excreted 24 hours after administration of the amines. Based on these results, we propose an HPLC method for the screening of risk assessment in the workplace. The presence of 3,4-DCA and 3,5-DCA in the urine of workers showed that they were absorbing amines during the workshift. CONCLUSIONS: These results successfully allowed us to detect contamination due to 3,4-DCA and 3,5-DCA in exposed workers. The HPLC method described provides a satisfactory and sensitive procedure for urine screening in the assessment and monitoring of the occupational exposure to dichloroanilines.

In vivo study of percutaneous absorption of 4-chloroaniline using microdialysis in the rat.

The present work was undertaken to study the percutaneous absorption of 4-chloroaniline (parachloroaniline, PCPA, CAS 106-47-8), a chemical intermediate in pesticide manufacture, using in vivo microdialysis in the rat. The results of the microdialysis study showed that PCPA was able to cross the skin (Tmax = 3 h and area under the curve (AUC) = 332.1 ng.h/ml) and rapidly enter the systemic circulation (Tmax = 3.3 +/- 0.6 h). It could be also shown that PCPA was partly metabolised during its percutaneous absorption. The analysis of cutaneous dialysate samples using gas chromatography/mass spectrometry (GC-MS) showed that the metabolite was 4-chloracetanilide. Taken together, the data obtained showed that contact with the skin is a danger for exposed persons.

In vitro study of the percutaneous absorption of four aromatic amines using hairless rat skin.

Using hairless rat skin maintained in a Franz diffusion cell, the percutaneous penetration of four aromatic amines: para-chloroaniline (PCPA), meta-trifluoromethylaniline (mTFMA), dichloro-3,4-aniline (3,4-DCA) and dichloro-3,5-aniline (3,5-DCA) were studied. The purpose of the studies was to determine the permeation parameters (rate of permeation, permeability rat constant) in order to compare the rate of absorption of the four amines. The results show that the four amines penetrate significantly across the skin, but with different rates. 10 h after in vitro application (2 mg/cm2), the extent of permeation was PCPA >> mTFMA > 3,4-DCA > 3,5-DCA.

Blood and cerebral concentrations of the new potential analgesic UP 26-91 measured in vivo by microdialysis after toxic doses.

The concept of proportionality between the pharmacological effects of drugs and their dosage has been questioned since the discovery of saturable phenomenon for some drug dispositions, either during their absorption or their elimination. Such saturation may also occur during the distribution phase in the tissues. This phenomenon, however, is often difficult to demonstrate and microdialysis is a powerful technique to assess precise changes in drug concentrations in tissue. This technique has been used to compare brain and blood concentrations of a potential analgesic, UP 26-91 (3-¿[2-[4-(2,4-difluorophenyl)piperazin-1-yl]ethyl]thio¿ -1,2,4-triazolo[4,3-a]pyrioline, citrate salt, CAS 115762-17-9 for the base), at different intravenous doses. Microdialysis probes were surgically implanted in the cerebral cortex and the jugular vein of male Sprague-Dawley rats (about 350 g). A single dose of radiolabelled 14(C) UP 26-91 mixed with unlabelled drug was injected into the animal's tail vein. Three doses of drug (2.5, 12.5 and 22.5 mg.kg-1) were tested, with three rats for each dose. All the doses consisted of the same amount of radiolabelled product, used as a tracer, supplemented by the amount of non-radiolabelled UP 26-91 necessary to reach the desired concentration. The rats were conscious, freely moving and had free access to food and water. Microdialysis samples were collected at the rate of 1 microliter.min-1, and sampled every 15 min for 16-17 h. The two highest doses were in the range of those used for toxicological studies. Blood UP 26-91 radioactivity concentrations were superimposable independent of the dose. Thus, it can be concluded that there was a linear relationship between blood concentrations and administered doses. By contrast, the brain concentration for the highest administered dose was statistically higher than the two others (p < 0.05), which demonstrated that UP 26-91 exhibited a non-linear pharmacokinetics in the brain. It is therefore likely that a saturable transport mechanism occurs across the blood-brain barrier. This study demonstrates that blood toxicokinetics may not correctly reflect tissue exposure to a drug.

[Oral administration effects, with different doses, of arginine aspartate and arginine chlorhydrate upon growth hormone and free fatty acids plasmatic rates in normal fasting children (author's transl)]. / Effets de l'administration "Per Os", à doses variables, d'aspartate d'arginine et de chlorhydrate d'arginine sur les taux d'hormone de croissance et d'acides gras libres du plasma chez l'enfant normal à jeun.

With an equivalent arginine base furniture, arginine chlorhydrate (CA) and arginine aspartate (AA) are orally administered, with variable doses, to normal fasting children, to study during 4 hours evolution of plasmatic growth hormone rates (stimulation of endogenous GH secretion) and plasmatic free fatty acids rates (secondary effects on effectors). With CA 5 g (half dose) opr 10 g (total dose, about 500 mg/kg) mean plasmatic GH rates increase is etale and non significant, when compared to normals. With AA 7,35 g (half dose) or 14,70 g (total dose), there is a 2 h GH peak, when compared to initial values and 2 h normal values (p less than 0,05 or p less than 0.01). Area increases with the two doses AA, when compared to normals (p less than 0,01). With the two products, mean 1 h plasmatic FFA rate does not vary or non significantly decreases. 4 h rate increases, when compared to normals, with CA and AA half dose (p less than 0,05) and CA and AA total dose (p less than 0,01).

[Fluorine uptake by calcified tissues in the guinea pig after 18 months exposure to an atmosphere containing 100 to 150 mcg hydrofluoric acid per cubic meter]. / Etude de la fixation du fluor au niveau des tissus calcifiés chez le Cobaye après 18 mois d'exposition à une atmosphère renfermant 100 à 150 microgram d'acide fluorhydrique par mètre cube.

In the conditions described, inhaled HF is uptaken progressively by bones and teeth. Metabolic processes involved in calcification are disturbed and serum alkaline phosphatase activity is increased. The transfer of fluoride ion through placenta is revealed by an increase of bone fluorine in newborne Guinea Pigs issued from intoxicated mothers.

[Arginine aspartate effects on acute human alcoholizing test (author's transl)]. / Effets de l'aspartate d'arginine sur l'épreuve d'alcoolisation aiguë sur l'homme.

One oral arginine aspartate administration (10g), 30 minutes after the beginning of acute human alcoholizing test (150 ml whisky 45 degrees, 67,5 g pure alcohol, mean load about 1 g/kg), provokes the following effects. Clinically, intensity and lasting alcohol manifestations are reduced. Alcoholemic absolute curve (g/l) does not vary: 1 h peak equal in the two treated and non treated groups, similar 6 h levels but a little lesser in the treated subjects, without significative difference. Alcohol space does not vary. Arginine aspartate provokes a significant increase between 1 h and 4 h of alcoholemic disparition slope, when rapported to body weight: mg/kg/h (p < 0,02), and ethyloxydation coefficient: mg/kg/h (p < 0,05).

[Arginine aspartate effects on rabbit acute and chronic alcoholization (author's transl)]. / Effets de l'aspartate d'arginine sur l'alcoolisation aiguë et chronique du lapin.

Oral arginine aspartate treatment effects (acute administration: 1 g 30 minutes after load, chronic administration: 0.33 g a day during 9 months) are researched on rabbit acute alcoholizing load (1 ml alcohol 40 degrees/100 g) and alcohol chronic intoxication (0,5 ml alcohol 40 degrees/100 g a day during 9 months). 1) Arginine aspartate acute administration decreases 6 h alcoholemic rates, when compared to normals T + t receiving an equal nutritional placebo at 30 minutes (p < 0.01), without 1 h peak modification, and increases ethyloxydation coefficient (p < 0,01). Aspartate, arginine or pyruvate isolated administration at 30 minutes, increases ethyloxydation coefficient in following order: arginine (no significant difference with T + t), pyruvate + arginine and pyruvate (limit p 0,10 or p < 0,05), aspartate (p < 0,05). It is maximum with arginine aspartate (p < 0.01). 2) Arginine aspartate chronic administration partially reduces hyperalcoholemy (p < 0,01) and hypertriglyceridemy (p < 0.10), strongly increased in non treated alcoholized (p < 0.01). Transaminases rates, which remained about normal in non treated alcoholized, decrease under same time alcoholized (p < 0,10) and 0 values (p < 0.05). Hepatic histology shows, after 9 months, in alcoholized group, inflammatory oedema with some cellular damage, without steatosis. Arginine aspartate seems to provoke some hepatic protection with cellular regeneration.

[Evoluation of biologic balance as a function of radiologic status in a population living in a endemic fluoride zone of southern Algeria]. / Evolution du bilan biologique en fonction du stade radiologique chez une population vivant dans une zone d'endémie fluorée du sud algérien

Chronic fluoride intoxication in subjects living in an endemic South Algerian zone: El Oued (drinking water fluor: 3 to 5 mg/l), provokes some blood and urinary levels modifications, when compared to normals living in Algiers (drinking water fluor: 0,6 mg/l). These modifications are the more often present in stade 0 (normal radiologic aspect) and do not increase with radiological evolution (stades I, II, III). Fluoremy and fluorury increase. Phosphocalcic metabolism is altered. Tubular reabsorption coefficient, particularly, decreases strongly. Using renal functional exploration, a pretty soon tubular failure is founded, which preceeds glomerular failure. Blood levels of certain products and enzymes are studied.

[Effects of arginine and growth hormone, administered in vivo and in vitro, on the oxygen consumption of rat liver hemogenates]. / Effets de l'arginine et de l'hormone croissance administrées "in vivo" et "in vitro" sur la consommation d'oxygène d'homogénats de foie de rat

Effects of arginine aspartate, arginine chlorhydrate, potassium aspartate, with equal arginine base and aspartate ion available for all there compounds, growth hormone, and association of these different substances, are studied on rat hepatic homogenates oxygen consumption during 7 to 12 h, after injection to rats 1 h before sacrifice (A.A.: 0.50 g, C.A.: 0.34 g, A.K.: 0.22 g, STH: 2 U.I.), or "in vitro" adjunction to the preparation (A.A.: 0.125 g, C.A.: 0.085 g. A.K.: 0.055 g. STH: 0.5 U.I./0.25 g of liver). 1) "In vivo", arginine (endogenous STH secretion stimulation) is active: A.A. (+23% to +96% from 1 h to 8 h, p is less than 0.01), C.A. (+49% from 5 h to 8 h, p is less than 0.01), whereas potassium aspartate is inactive. "In vitro", aspartate is active: A.K. (+24% to +147% from 4 h to 12 h, (p is less than 0.01), A.A. (+56% to +53% from 7 h to 12 h, p is less than 0.01), whereas arginine without aspartate: C.A. is inactive. 2) Exogenous STH is active "in vivo" (+111% from 5 h to 8 h, p is less than 0.01) and "in vitro" (+31% from 4 h to 7 h, p is less than 0.01). 3) Association A.A. + STH (endogenous STH + exogenous STH) when given "in vivo", dose not produce any additive effect the tissue Vo2 release (+91% from 5 h to 8 h, p is less than 0.01) does not differ from STH and A.A. Aspartate added to STH "in vitro" enhances STH effects: (A.A. + STH: + 44% to +114% from 4 h to 12 h, p is less than 0.01, A.K. + STH: 73% to + 152% from 4 h to 12 h, p is less than 0.01).

[Effect of subacute fluorine poisoning in the rabbit on fluorine and phosphorus-calcium metabolism and on radiography of the skeleton]. / Effets de l'intoxication fluorée subaiguë du lapin sur les métabolismes fluoré et phosphocalcique et sur la radiographie du squelette.

Rabbit subacute fluoride intoxication effects (21,4 mg a day for 10 months) are researched on fluor, calcium and phosphorus metabolism and on skeletal radiology. Fluoremy increase (p less than 0.05) and there is a strong fluor retention (p less than 0.01), due to fluor digestive utilization coefficient increase (p less than 0.05), in spite of relative hyperfluorury (p less than 0.05). Calcemy decreases (p less than 0.01), but phosphatemy and alkaline phosphatasemy do not vary but a little. Calcium and phosphorus balances become negative (p less than 0.05), due to calcium digestive utilization coefficient inversion (p less than 0.05) and phosphorus digestive utilization coefficient decrease (p less than 0.05) and hypercalciury (p less than 0.05) and hyperphosphatury (p less than 0.05) with phosphorus renal reabsorption coefficient decrease (p less than 0.05). Some skeletal radiological abnormalities appear on rachis and limbs.

[The effects of arginine and growth hormone on the nitrogen balance of rats]. / Effets de l'arginine et de l'hormone de croissance sur le bilan d'azote du rat

Intramuscular administration effects of arginine aspartate (AA : 0,50 g a day for 4 days), arginine chlorhydrate (CA : 0.34 g a day for 4 days), potassium aspartate (AK : 0.22 g a day for 4 days) with equal arginine base and aspartate ion supply for all products, bovine growth hormone (STH : 2 U.I. a day for 4 days), and the association of these substances, are studied on 6 rats, during a 74 days nitrogen balance period. Arginine (endogenous STH secretion stimulation) produces a greater nitrogen retention with AA (+ 184%, p less than 0.01) than CA (+ 71% p less than 0.10). A.K. had no effect. With exogenous STH, effect is important (+ 248%, p less than 0.01) but does not significantly differ from AA. STH + A.A. and STH + C.A. associations (exogenous and endogenous STH) produce a very marked nitrogen retention (+ 282% and + 252%, p less than 0.01) which, however, does not significantly differ from STH when given alone.