Komparativna analiza tumora sjemenika pasa upotrebom histopatološke pretrage i metodom protočne citometrije

Tumori sjemenika pasa najčešći su tumori spolnog sustava te među najčešćim tumorima pasa uopće. Većinom se dijagnosticiraju u kasnijoj fazi, kada dođe do povećanja sjemenika, te se u svrhu liječenja obavlja kastracija nakon koje se postavlja dijagnoza na temelju histopatološke pretrage. U ovom je istraživanju provedena histopatološka analiza i klasifikacija arhiviranih uzoraka najčešćih tumora sjemenika pasa (9 uzoraka) i jednog uzorka nepromijenjenog sjemenika, te je provedena analiza DNK metodom protočne citometrije. Provedenom komparativnom analizom nastojala se utvrditi korelacija između tipova tumora i rezultata protočne citometrije, tj. jesu li promjene u genetičkim ili fizikalnim svojstvima tumorskih stanica povezane s histološkim tipom tumora. Utvrđeno je da je histopatološka pretraga objektivna dijagnostička metoda za razlikovanje pojedinih tipova tumora sjemenika u pasa. Dobiveni rezultati protočne citometrije, iako nisu bili dostatni i dovoljno precizni za donošenje definitivnog zaključka o karakteristikama istraživanih neoplastičnih promjena, pokazuju da je primjenom protočne citometrije na uzorcima sjemenika pasa moguće dobiti nove informacije o svojstvima stanica. Kako bi se protočna citometrija i njezini rezultati mogli objektivnije analizirati te koristiti u dijagnostici neoplazija testisa u pasa, potrebno je optimizirati i standardizirati metodu te postaviti detaljne dijagnostičke kriterije, za što je potrebno provesti istraživanje na znatno većem broju uzoraka tumorozno promijenjenih i patološki nepromijenjenih sjemenika. Metoda protočne citometrije može pomoći u dijagnostici tumora sjemenika pasa, osobito ako je kombinirana s do sada uhodanim metodama pretrage kao što je histopatološka analiza tumora sjemenika

Komparativna analiza tumora sjemenika pasa upotrebom histopatološke pretrage i metodom protočne citometrije

Tumori sjemenika pasa najčešći su tumori spolnog sustava te među najčešćim tumorima pasa uopće. Većinom se dijagnosticiraju u kasnijoj fazi, kada dođe do povećanja sjemenika, te se u svrhu liječenja obavlja kastracija nakon koje se postavlja dijagnoza na temelju histopatološke pretrage. U ovom je istraživanju provedena histopatološka analiza i klasifikacija arhiviranih uzoraka najčešćih tumora sjemenika pasa (9 uzoraka) i jednog uzorka nepromijenjenog sjemenika, te je provedena analiza DNK metodom protočne citometrije. Provedenom komparativnom analizom nastojala se utvrditi korelacija između tipova tumora i rezultata protočne citometrije, tj. jesu li promjene u genetičkim ili fizikalnim svojstvima tumorskih stanica povezane s histološkim tipom tumora. Utvrđeno je da je histopatološka pretraga objektivna dijagnostička metoda za razlikovanje pojedinih tipova tumora sjemenika u pasa. Dobiveni rezultati protočne citometrije, iako nisu bili dostatni i dovoljno precizni za donošenje definitivnog zaključka o karakteristikama istraživanih neoplastičnih promjena, pokazuju da je primjenom protočne citometrije na uzorcima sjemenika pasa moguće dobiti nove informacije o svojstvima stanica. Kako bi se protočna citometrija i njezini rezultati mogli objektivnije analizirati te koristiti u dijagnostici neoplazija testisa u pasa, potrebno je optimizirati i standardizirati metodu te postaviti detaljne dijagnostičke kriterije, za što je potrebno provesti istraživanje na znatno većem broju uzoraka tumorozno promijenjenih i patološki nepromijenjenih sjemenika. Metoda protočne citometrije može pomoći u dijagnostici tumora sjemenika pasa, osobito ako je kombinirana s do sada uhodanim metodama pretrage kao što je histopatološka analiza tumora sjemenika

Skin reaction and recovery: a repeated sodium lauryl sulphate patch test vs. a 24-h patch test and tape stripping

Background Little is known of the predictive value of methods to test an individual's susceptibility to acquiring occupational contact dermatitis. Recently, the recovery rate after induced irritation was suggested for this purpose. Although it is likely that repeated exposure to sodium lauryl sulphate (SLS) is preferable to a single application, there is little evidence to support this idea. Similarly, little is known about whether the outcome of a repeated SLS test can be predicted by a brief test. Objectives We studied the relationship between the skin reaction after a repeated SLS test and two brief tests, devoting special attention to the recovery rate. Methods In 29 healthy volunteers, we measured transepidermal water loss (TEWL) and erythema after applying 0.03, 0.1 and 0.3% SLS for 6 h, 3 days per week, over a course of 3 weeks. The data were compared with the effects after applying 0.1, 0.3 and 1.0% SLS for 24 h and with 10 and 15 repetitions of tape stripping. Results A poor correlation was found between the repeated test and the brief SLS test, or tape stripping, when using an increase in TEWL (r = 0.04 and 0.26, respectively) or its recovery rate (r = - 0.01 and 0.42, respectively). Conclusions We presume that in a repeated test of sufficient duration, additional mechanisms come into play that are absent in a brief test, e.g. an alteration in the thickness of the epidermis, with a resulting change in the permeability of SLS. When such an effect differs between subjects it could explain the lack of agreement between the acute and the repeated tests. At present, a brief irritation test will, in all likelihood, be unable to assess an individual's susceptibility to occupational contact dermatiti

137Cs in flowers, pollen and honey from the Republic of Croatia four years after the Chernobyl accident

137Cs concentration was measured in flowers, pollen and honey, samples of which were collected from the Republic of Croatia 4 years after the Chernobyl accident. Radioactivity of 137Cs was measured by gamma-spectrometry. Cesium in honey corresponds well with 137Cs contamination of territory in the Republic of Croatia. Activity of 137 Cs in pollen which is higher than in honey indicates that cesium behaves analogously to potassium. The results show that equal cesium concentration in the surface soil layer results in higher cesium activities in honey in the case of meadow flowers, ie honey bee pasture, than in cases when pasture is based on bush and tree flowers. Cesium activity average in honey, collected from the Republic of Croatia territory, is < 1 % of the permissible level of 600 Bq/kg

Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers.

OBJECTIVES: To estimate dermal absorption of vaporous and liquid 2-methoxyethanol (ME) and 2-ethoxyethanol (EE) in volunteers. METHODS: Five volunteers (two men and three women) were dermally exposed to vaporised and liquid ME and EE. Dermal exposure on an area of about 1000 cm2 (forearm and hand) to vapours of ME and EE (4000 mg/m3 ME and 3700 mg/m3 EE) lasted for 45 minutes. Duration of exposure to liquid ME and EE on an area of 27 cm2 (forearm) was 15 minutes. Dermal uptake was assessed by measurement of the main metabolites in urinary methoxyacetic acid (MAA) and ethoxyacetic acid (EAA). For each volunteer, excretion of metabolites was compared with a reference inhalatory exposure. RESULTS: Mean (SD) absorption rates of ME and EE vapour were 36 (11) and 19 (6) cm/h respectively. The mean (SD) absorption rates of the liquid ME and EE amounted to 2.9 (2.0) and 0.7 (0.3) mg/cm2.h. CONCLUSIONS: Vaporised and liquid ME and EE are readily absorbed through the skin. In the combined inhalatory and dermal exposure when whole body surface is exposed to vapour, the uptake through the skin is estimated to be 55% of the total uptake of ME and 42% of EE. Dermal uptake resulting from skin contact of both hands and forearms (about 2000 cm2) with liquid ME and EE for 60 minutes would exceed inhalatory uptake of the eight hour occupational exposure limit by 100 times at 16 mg/m3 of ME and 20 times at 19 mg/m3 of EE. The substantial skin uptake of ME and EE indicates that in assessing the health risks biological monitoring and use of biological exposure indices are preferable to environmental monitoring

Dermal absorption of vaporous and liquid 2-methoxyethanol and 2-ethoxyethanol in volunteers

To estimate dermal absorption of vaporous and liquid 2-methoxyethanol (ME) and 2-ethoxyethanol (EE) in volunteers. Five volunteers (two men and three women) were dermally exposed to vaporised and liquid ME and EE. Dermal exposure on an area of about 1000 cm2 (forearm and hand) to vapours of ME and EE (4000 mg/m3 ME and 3700 mg/m3 EE) lasted for 45 minutes. Duration of exposure to liquid ME and EE on an area of 27 cm2 (forearm) was 15 minutes. Dermal uptake was assessed by measurement of the main metabolites in urinary methoxyacetic acid (MAA) and ethoxyacetic acid (EAA). For each volunteer, excretion of metabolites was compared with a reference inhalatory exposure. Mean (SD) absorption rates of ME and EE vapour were 36 (11) and 19 (6) cm/h respectively. The mean (SD) absorption rates of the liquid ME and EE amounted to 2.9 (2.0) and 0.7 (0.3) mg/cm2.h. Vaporised and liquid ME and EE are readily absorbed through the skin. In the combined inhalatory and dermal exposure when whole body surface is exposed to vapour, the uptake through the skin is estimated to be 55% of the total uptake of ME and 42% of EE. Dermal uptake resulting from skin contact of both hands and forearms (about 2000 cm2) with liquid ME and EE for 60 minutes would exceed inhalatory uptake of the eight hour occupational exposure limit by 100 times at 16 mg/m3 of ME and 20 times at 19 mg/m3 of EE. The substantial skin uptake of ME and EE indicates that in assessing the health risks biological monitoring and use of biological exposure indices are preferable to environmental monitorin

Metabolism of styrene in the human liver in vitro: interindividual variation and enantioselectivity

1. The interindividual variation and enantioselectivity of the in vitro styrene oxidation by cytochrome P450 have been investigated in 20 human microsomal liver samples. Liver samples were genotyped for the CYP2E1*6 and CYP2E1*5B alleles. 2. Kinetic analysis indicated the presence of at least two forms of styrene-metabolizing cytochrome P450. The enzyme constants for the high-affinity component were subject to appreciable interindividual variation, i.e. Vmax1 ranged from 0.39 to 3.20 nmol mg protein(-1) min(-1) (0.96+/-0.63) and Km1 ranged from 0.005 to 0.03 mM (0.011+/-0.006). Inhibition studies with chemical inhibitors of CYP2E1, CYP1A2, CYP2C8/9 and CYP3A4 demonstrated that CYP2E1 was the primary enzyme involved in the high-affinity component of styrene oxidation. No relationship between the interindividual variation in Vmax1 and Km1 and the genetic polymorphisms of the CYP2E1 gene was found. 3. Cytochrome P450-mediated oxidation of styrene demonstrated a moderate enantioselectivity, with an enantiomeric excess (ee) of (S)-styrene oxide of 15% (range 4-27%) at low styrene concentration and an ee of (R)-styrene oxide of 7% (range -11 to +22%) at high styrene concentration. This points towards the involvement of at least two cytochrome P450, with different enantioselectivities. 4. The data indicate that cytochrome P450-mediated styrene oxidation is subject to considerable interindividual variation, but only to a moderate product enantioselectivit

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Specific activities of 40K, 134Cs and 137Cs in pollen, honey and in the first 25 cm of the surface soil layer were measured by gamma-spectrometry. Specific activity of 40K in pollen is about 1 order of magnitude higher than in honey. A 40K soil-to-pollen transfer coefficient (TC( 40K)) of 0.436 ± 0.054 and a soil-to-honey transfer coefficient TC(40K) of 0.052 ± 0.008 were calculated as the mean of their respective values in 26 different segments of soil profile. Both parameters have very stable values over time as well as through different segments of vertical soil profile. 134Cs and 137Cs specific activities in pollen and honey decrease with time, resulting in a decrease of 137Cs soil-to-honey transfer factors (Tf(137Cs)) over time. The increase of the soil-to-honey Tf(137Cs) with increasing soil depth is a consequence of vertical distribution of 137Cs in soil. Soil-to-honey T f(137Cs) values are highest in meadow and mixed honey types and lowest in bush/tree honey. Similar trends are found for both Tf(134Cs) and Tf(137Cs). The results presented here indicate the importance of the caesium inventory in soil segments where plant root systems are developed