الفهرس 
Skin microanatomy and physiologyOnly 14 pages are availabe for public view
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Abstract
The widespread existence of unhealed wounds, ulcers,
and burns has a great impact on public health and economy.
Many interventions, including new medications and
technologies, are being used to help achieve significant wound
healing and to eliminate infections. Therefore, to find an
intervention that has both therapeutic effect on the healing
process and the ability to kill microbes is of great value.
Human amniotic membrane is an abundant, inexpensive
and easily obtained tissue that is discarded post-partum. It
represents a valuable material to be used as a biological
dressing in developing countries.
The minimal ethical and legal issues associated with
amniotic membrane use, with non-invasive and safe
procedures and the low immunogenicity of amnion-derived
cells, make them an alternative source of MSCs.
Amnion contains two different cell types, hAECs and
hAMSCs, which display characteristic properties of stem cells.
Both amnion-derived populations are easily isolated from
HAM and have the capacity to differentiate in vitro into all
three germ layers: endoderm, mesoderm and ectoderm,
suggesting their great interest in the fields of cell therapy and
regenerative medicine.
The goal of this research was to study the benfit of
amniotic membrane as a dressing in skin wound healing in
adult and senile rats.
Sixty male albino rats were used in the study (thirty
adult and thirty senile) and were divided into six groups.
In group I skin specimens were obtained from the mid
back used as adult control rat skin.
In group II adult rats and group V senile rats: a
standardized 1 cm2 full-thickness wound was done on the mid
back. The wound was covered by bandage only. Rats of group
II and V were subdivided into 2 subgroups. In subgroup IIa
and Va the skin wound specimens were examined on day 3
and those of subgroup IIb and Vb were examined on day 7.
In group III adult rats and group VI senile rats: a
standardized 1 cm2 full-thickness wound was done on the mid
back. The wound was covered by amniotic membrane and
bandage. Rats of group III and VI were subdivided into 2
subgroups.In subgroup IIIa and VIa the skin wound specimens
were examined on day 3 and those of subgroup IIIb and VIb
were examined on day 7.
In group IV skin specimens were obtained from the mid
back used as senile control rat skin.
The skin specimens in each group were examined
histologically using Hx&E, Mallory’s Trichrome stain,
Aldhyde Fuchsin stain and semithin sections. Immunohistochemical
staining was performed for detection of positive
CD44 cells. Morphometric study was done and confirmed with
statistical analysis.
Untreated wounds examined on day 3 and 7 showed
discontinuity between the two ends of the wound which was
occupied by granulation tissue. The dermis appeared densely
cellular with mononuclear cellular infiltration and was highly
vascular. The collagen were arranged in irregular pattern.In
immuno-histochemical examination by CD44 antibodies, there
were negative reaction at the wound site.
The wounds treated by amniotic membranes were
examined on day 3 and 7 and showed healing of the wound
edges. The wound site showed regeneration of the epidermis.
The granulation tissue below showed apparent increase in the
collagen and elasic fibers.A significant decrease in
mononuclear cellular infiltration and increased
neovascularization in contrast to untreated wounds was also
noted. In immuno-histochemical examination by CD44
antibodies, there was positive reaction at the wound site.
It is concluded that, the use of amniotic membrane as a
dressing is effective in promoting wound healing. The findings
of the current study indicate that amniotic membrane dressings
may provide a powerful technique to augment healing of
clinically problematic wounds.