S. M. Rezaul Hasan / J. Biomedical Science and Engineering 3 (2010) 470-475 475
Copyright © 2010 SciRes. JBiSE
causes the immune response pathway to activate. This
results in the presence of either chemo-tectile (D-FF_2)
or photo-tectile (D-FF_3) micro-creatures during the
circadian interval <2,9>. Also, opsonized microcreatures
are present during the interval <3,10>, microcreatures
are ingested during the interval <4,11>, digestive vesi-
cles are formed near the phagocyte membrane during the
interval <5,12>, vesicles are detached and moves into
the cytoplasm during the interval <6,13>, phagolyso-
some is formed and the microcreature is hydrolyzed
(state in D-FF_8) and microcreature cell-wall is hydro-
lyzed (state in D-FF_9) during the interval <7,14>. The
breakdown of lipids (state in D-FF_10), proteins (state in
D-FF_11), ribonucleic acid (state in D-FF-12) and de-
oxyribonucleic acid (state in D-FF_13) take place simul-
taneously in the interval <8,15>. The undigested mi-
cro-creature artifacts (state in D-FF_14) are removed
during the interval <9,16>. As the micro-creatures are is
not present during the interval <9,12>, there is a short
pause in the digestive bio-chemical process which is
evident from the diagonal zero states in Figure 3(b).
Also, beginning the interval <13,16> the presence of a
short burst of microcreatures results in a short pipeline
of digestive pathway activities (reactions and interac-
tions) that is evident through the diagonal array of “1” as
shown in Figure 3(b).
5. CONCLUSIONS
A digital circuit based model for the phagocytic bio-
chemical digestive pathway in living systems has been
developed and discussed in detail. The model corre-
sponds quite well with the immune response phenome-
non depicting striking resemblance of CMOS logic cir-
cuit (with states in D flip-flops) to states in bio-cellular
phenomenon. Compared to mathematical modeling,
model derived from analogies with integrated circuit
allows VLSI CAD circuit and logic simulators to be con-
veniently used as a biological simulation program.
Hence this work provides an alternative route for further
systems biological investigation into more comprehen-
sive integrated circuit models for more extensive bio-
chemical pathways in living systems. This investigation
will thus contribute to the desired manipulation of bio-
logical processes at the cellular level leading to electrical
circuit modeling of diseases and “nano-medicine”.
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