الفهرس 
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Abstract
In the last few years, human fascioliasia was repor¬ted more frequently from different parts of the world. The problem of human fasciollasls has received little attention in Egypt, although the disease is widespread in domestic herbivorous animals, as reviewed by Halawani and Gindy. ’ Infection results from eating contaminated green veget¬ables or drinking water with encysted metacercariae.
The present work aimed to studying the ability of fascioliasis to metabolize the amino acid tryptophan through tryptophan niacin pathway, before and after tryptophan loading, the liver and kideny function tests and complete blood picture were taken in consideration*
In addition, the study included the determination of B-glucuronidase activity in serum of fascioliasis and exploring the relation between fascioliasis and this hydrolytic lysosomal enzyme.
The study was carried on 50 patients coming from Abis II village and 30 control subjects selected from the staff members and workers sons of the Medical Be search Institute. Children were more frequently infected than adolescents and adult, probably due to the lack of sanitary habits among them.
Tryptophan is an essential amino acid which has been shown to have a -variety of interesting and unique biological properties and functions, tryptophan also is a precursor of a vitamin (niacin) and a precursor of several biogenic amines (serotonin, melatonin, etc •••) with a variety of psyconeuroendocrine properties still not completly defined*
The major metabolic pathway of tryptophan in mammales is the kynurenine pathway. Since some trypto¬phan metabolites through this pathway have been suspec¬ted to be carcinogenic i.e, kynurenine, acetyl kynure-
nine, 3-hydroxy kynurenine, 3-hydroxy anthranilic acid,
(15)
and xanthurenic acid thus, it may be of a value to
determine the level of these metabolites In urine of fascioliasis.
After thorough clinical examination and routine laboratory investigations the following studies were performed:
1. Determination of the urinary levels of tryptophan metabolites. The metabolites determined were ISA, AAG, O-AH, AA, ACK, 3-OHK, KN, 3-OHAA, KA, IA, l^MCT and in addition, 4-PA which is the major metabolite of vitamin Bg. The urine sample included:
a) Basal 24-hours urine.
b) 24-hours urine after giving a loading dose of 2 g L-tryptophan,
. Determination of serum B-glucuronidase activity.
In the light of the results, which were fully iscussed the following conclusions seemed to be of articular outstanding interest:
Fascioliasis showed altered abnormal pattern of tryptophan metabolism since the spontaneous urinary excretion level of tryptophan metabolites (without any loading of the amino acid) i.e. basal values showed a statistically significant increases in the levels of (KH, 3-QHK, ACK, XA, KA and ff-jMHT) and a sta¬tistically significant decrease in ISA and 4-PA levels as compared to the corresponding values in control. After tryptophan loading the excretion of AA and 3-OHAA which were normally excreted before the loading dose were found to be statistically increased together with other metabolites which were already increased in basal urine• AAG and 4-pyridoxic acid were the only metabolites which were significantly less excreted when compared to the corresponding control values.
In order to explain the ability of fasciola infected patients to metabolize the loading dose of tryptophan, patients were compared with controls with respect to their ability to metabolize the loading dose of tryptophan i.e., their response to this load¬ing dose. This response was evaluated by the quantity of the urinary tryptophan metabolites excreted in ex¬cess of the basal level (Yield).
The pattern of tryptophan metabolites in fas-cioliasis suggested that these patients were suffer¬ing from moderate Bg-deficiency since the excretion of kynurenine, 3-hydroxy kynurenine and xanthurenic acid were elevated. ’-” Prom these results it could be suggested that kynurenine aminotransferase, responsible for the convertion of kynurenine to kynurenic acid, is the only Bg-dependent enzyme which was inhibited in fascioliasis. This suggested B,--deficiency is confirmed by the low excretion level of 4-pyridoxic acid encountered in the basal and post tryptophan urine of fasciola infected patients as compared to controls.
z Serum B-glucuronidase activity in fasciola infected pat¬ients were significantly higher than in control. This increase in enzyme activity points to the underlying liver
damage. The ability of B-glucuronid»ae to split car¬cinogenic substances in the body^143, 198’ 156^ reises the possibility of carcinogenesis*
The haematological parameters showed that the majority of fasciola cases were suffering from anaemia since the majority of cases were found to have Hb level and erythrocytic count below normal range* This anaemia
was suggested to be caused by the toxic substances
(7 186)
emanating from thePluke.v’ » ’ Induction of anaemia
by chemical is also suggested by Isseroff et al* ’ who suggested that infussion of prolin, an amino acid released by ffasciola hepatica in large quantities was the cause of anaemia encountered in faacioliasis. Also fascioliasis showed clearly that some oases had leucopenia and other had leucocytoais as the by-pro¬ducts of parasites introduced into the human body usually stimulate a host reaction which is both local and general in type.
Blood urea and serum creatinine level were within normal range denoting absence of any disturbance in kidney functions.
Concerning liver function tests this study revealed that the mean values of SGPT were within the normal
rang, while the *ean values of both SGOT and A* „„ slightly exceed the Mlaua Taluea of ^ ^ ^ controls A^ fladlaB waa
authors. (195.182,199) .„ ^
They explained it by hyper¬plasia of the biliary epitfceliun, „i* oede^toue and cystic dilatation due to the ^ohanical and toxic action of parasites.(196,197)