الفهرس 
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Abstract
Summary
Cryptosporidiosis which is caused by the protozoan
parasites of the genus Cryptosporidium is a major health problem
for humans and livestock. Cryptosporidium infection can cause
severe consequences in immune deficient hosts. No effective
drug therapy has been approved till now. Thus, it is increasingly
necessary for evaluating new potential drugs against
Cryptosporidium in immunocompromised patients.
In the present study, the efficacy of miltefosine, a
phospholipid drug which has been introduced as antileishmanial
effective agent and water extract of Phoenix dactylifera fruits
were evaluated in mice infected with Cryptosporidium.
The study was conducted on seventy laboratory CD1mice
with a weight range of 20-25 gm. The animals were provided by
the Schistosome biological supply program (SBSP) at Theodor
Bilharz Research Institute (TBRI) and were divided into three
main groups.
Control group (A) comprising 10 animals (uninfected and
untreated) .Group (B) immunocompetent infected group
comprising 30 mice which were infected by oral-gastric gavage.
Each mouse was inoculated with 200µl of PBS containing
10P
3
Psporulated C. parvum oocysts. Group (C) immunosuppressed
Summary
182
infected group comprising 30 mice received (Dexamethasone)
drug in a dose of 20 mg/kg/day intramuscularly for 20 days three
times per week, then each mouse was inoculated with 200µl of
PBS containing 10P
2
P sporulated C. parvum oocysts.
Both groups (B and C) were subdivided into three equal
infected subgroups. Subgroup (B1) immunocompetent infected
while subgroup (B2) infected and treated with miltefosine and
subgroup B3 infected and treated with water extract of P.
dactylifera fruits. Moreover, subgroup (C1) immunosuppressed
infected while subgroup (C2) immunosuppressed infected and
treated with miltefosine and subgroup (C3) immunosuppressed
infected and treated with water extract of P. dactylifera fruits.
Faecal analysis was performed and the number of
Cryptosporidium oocysts/gm of faeces was counted for
parasitological study ten days and three weeks after treatment.
Molecular study and histopathological examination of
intestinal, liver sections and spleen were held. Phagocytic index
and several serological studies including interferon (IFN)-γ and
interleukin (IL)-4, (IL)-10 and (IL) - 17 were assessed in mice
serum.
Molecular study by nested PCR (targeting COWP gene)
was carried out to determine Cryptosporidium genotypes and
revealed Cryptosporidium parvum.
Summary
183
The percentage of reduction in the number of C. parvum
oocysts after 10 days of treatment with miltefosine, in both
immunocompetent infected and immunosuppressed infected
groups was non -significant (p>0.05). While the percentage of
reduction in the number of C. parvum oocysts after ten days of
treatment with P. dactylifera was highly statistically significant
(p<0.001).The percentage of reduction in the number of C.
parvum oocysts after three weeks of treatment with miltefosine
and P. dactylifera extract in both immunocompetent and
immunosuppressed were highly statistically significant
(p<0.001).
Several degrees of inflammatory changes were seen in all
infected groups. Major histological changes were observed in
intestine of immunosuppressed infected group associated with
complete, severe villous atrophy changes. Low-grade dysplasia
was investigated. Also in this study, the use of Modified Ziehl -Neelsen staining technique in tissue was attempt for the first
time. Sections of small intestine, C. parvum oocysts, were
visualized in the intestinal glandular epithelium as oval and
round shaped.
Treated mice with miltefosine showed improvement of the
lining epithelium of the intestine, while complete healing of
intestinal mucosa was seen after treatment by aqueous extract of
P. dactylifera fruits.
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184
Liver sections of immunosuppressed infected mice
revealed some moderate pathological changes such as
inflammatory cellular infiltrations and hepatocytic vacuolations.
Treatment by miltefosine and aqueous extract of P. dactylifera
fruits revealed remarkable healing of liver tissue.
Spleen sections of mice from immunosuppressed infected
group revealed disorganization of the splenic tissue including
atrophic white pulp and distended red pulp with sheets of
megakaryocytes representing the extra medullary hematopoiesis.
Three weeks after treatment by miltefosine and aqueous extract
of P. dactylifera fruits revealed normal architecture of spleen
tissue.
By the end of the experiment ultrastructural examination of
the small intestine reported remarkable destruction of the
intestinal cell projection by C. parvum infection with
degeneration of intestinal submucosa. With miltefosine treatment
partial healing of the destructed intestinal cell projections was
observed. Meanwhile, P. dactylifera treatment showed complete
repair of the intestinal cell projections as well as healing of the
mucosa and the submucosa.
Primary and secondary immune responses were noticed
before and after treatment. Three weeks after administration of
miltefosine the means of phagocytic cells decreased in infected
Summary
185
treated with miltefosine drug while slightly increased in
immunosuppressed infected treated with miltefosine. Three
weeks treatment with aqueous extract of P. dactylifera fruits
significant differences (p < 0.05) were seen between all groups
infected and treated.
Serum circulating cytokines (IFN-γ, IL-4, IL-10 and IL-17) were increased during the infection and treatment period in
mice groups when compared to the control normal group. Only
IFN-γ and IL-17 levels increased in infected and
immunosuppressed infected groups after treatment with
miltefosine. In treated mice by P. dactylifera all cytokines level
decreased reaching nearly to control normal mice levels.