Resistividad del agua de formación (R w )

A second dose response study was conducted in which the amount of CHT

used was reduced. 20 guinea pigs were sensitised with DNCB on the ear and

maintained on normal drink water for 2 weeks. The animals were then divided into

4 groups of 5 and challenged with DNCB on the flank.

Protocol:

Control: 2 weeks water

1/4 CHT: 2 weeks water

1/2 CHT: 2 weeks water

CHT : 2 weeks water

2 weeks water 2 weeks water

2 weeks 1/4 CHT 2 weeks 1/4 CHT 2 weeks 1/2 CHT 2 weeks 1/2 CHT 2 weeks CHT 2 weeks CHT I I I _{1 1} challenge challenge sensitisation measurement

All animals showed positive skin test measured at 24 and 48 hours (Fig

5.3.9). One group of animals was maintained on normal drink water for a further 4

weeks. The other 3 groups were given 150mg/guinea pig/day, 75mg/guinea pig/day

and 38mg/guinea pig/day respectively. All animals were rechallenged after a further

2 weeks and again at 4 weeks.

All guinea pigs produced significant skin reactions when they were

treatment, all animals showed reduced skin reactivity when they were re-challenged

with DNCB. The guinea pigs receiving standard CHT (150mg/guinea pig/day)

showed significant reduction in skin reaction when compared to controls (CHT 2

weeks 24h: 0.21±0.10mm, 48h: 0.14+0.09mm, 4 weeks CHT 24h:0.40±0.17mm,

48h: 0.24+0.07mm; controls 2 weeks 24h 0.55+0.14mm, 48h 0.34+0.12mm, 4

weeks 24h 0.79±0.47, 48h 0.47+0.13 mm p < 0 .0 5 in each case when compared to

relevant controls). The other two groups of guinea pigs receiving lower dosages (75

and 37.5 mg/guinea pig/day respectively) of CHT showed a degree of reduction in

skin reaction to DNCB challenge but the reduction were not significant compared to

the controls in both cases. It was also noticed that all animals gave increased skin

reactions when they were re-challenged in the later weeks and the control group

showed a greater degree of progressive increase than all other CHT treated

1 = 1 Control 1/4 CHT 1^ ^ :^ CHT m m 1/2 CHT 1.00-1

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24 h 48 h Before CHT 24 h 48 h After 2 weeks 24 h 48 h After 4 weeks T i m e a f t e r c h a l l e n g e w i t h D N C B

Fig 5.3.10Guinea pigs were sensitised with DNCB and

challenged 2 weeks later, the skin thickness was recorded. They were given CHT afterwards for 4 weeks. Guinea pigs were challenged with DNCB after CHT had been given for 2 and 4 weeks, skin thickness were then recorded at 24 and 48 hours after challenge.

5.3.11 Com parison of the effects of CHT using different adm inistration

methods

Most medicines that include Chinese herbs, are administrated orally to

patients. In this case, Chinese herbs are taken by AD patients orally as a decoction

twice daily. To investigate whether the effect of CHT taken by guinea pigs in

drinking water is different from the effect of CHT given by gavage (an equivalent

practical method used in animals), a direct comparison was made of CHT given to

two groups of animals in these two different ways.

Protocol: (G = gavage; D=drinking)

Control: 2 weeks water 2 weeks water 2 weeks water

2 weeks CHT(G) 2 weeks CHT(G) 2 weeks CHT(D) 2 weeks CHT(D) CHT(G): 2 weeks water CHT(D): 2 weeks water J_LL 111 11 challenge challenge sensitisation measurement measurement

15 guinea pigs were divided into 3 groups of 5. They were all sensitised

with 5mg of DNCB on the ear and were given normal drink water for 2 weeks.

After 2 weeks of sensitisation, all animals were challenged with 0.15% DNCB and

the skin thickness were recorded. After challenge, the control group were given

normal drinking water for the following 4 weeks; one treated group received CHT

(150mg/guinea pig/day) for 4 weeks. All guinea pigs were re-challenged with

0.15% DNCB after 2 and 4 weeks of the first challenge. The skin reactions were

recorded at 24 and 48 hours after challenge.

There were clear increases in skin thickness when guinea pigs were

challenged with DNCB in each group before CHT therapy(24h control: 0.36+0.12,

CHT(D): 0.3910.20, CHT(G): 0.4410.19; 48h control: 0.3410.17, CHT(D):

0.3410.16, CHT(G): 0.4010.16). No significance difference in the increase of skin

thickness among the three groups was found (p > 0 .0 5 in each case). A significant

reduction in the increase of skin thickness was observed in the guineas after they

were treated for 2 weeks, both in the group which were given the CHT in drinking

water and in the group treated by gavage (24h control: 0.4110.09,

CHT(D):0.1810.13, CHT(G): 0.2610.17; 48h control: 0.3610.19, CHT(D):

0.1510.12, CHT(G): 0.2610.17 mm). Guinea pigs treated with CHT in drinking

water showed a clearly greater but insignificant reduction in the skin thickness

compared to that of guinea pigs treated by gavage. After 4 weeks treatment of

CHT, guinea pigs treated with CHT, either taken by gavage or in drinking water

Control

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0.6- ESSS3 CHT(D) " CHT(G) i

1

24h 48h Before therapy 24h 48h After 2 weeks 24h 48h After 4 weeks

Fig 5.3.11. CHT was given to guinea pigs by adding to drinking water (CHT(D)) or gavage (CHT(G))for a period of 4 weeks. Challenges were made at before therapy and 2 and 4 weeks after therapy. Measurements were made at 24 and 48 hours after challenge. CHT was given for 4 weeks.

In document Desarrollo de un simulador para análisis e interpretación de registros eléctricos de pozos petroleros (página 94-99)