This article is classified "Real"
Humans, the dominant species of the planet Sol III, Orion Arm, are
remarkably less intelligent than their apparently ascendent status might
lead one to believe. Take, for example the common human phrase "Dog is
man's best friend." First, this phrase is quite misleading in its choice
of words, as any rational reader would come to the conclusion that this
"dog" (canis domesticus L.) is somehow preferentially attracted to adult
males of the human species. Nothing could be further from the truth, as
"Man" in this case is meant to mean all members of the species homo
sapiens regardless of their gender or age. The fact that humans seem not
to be in the least bit perturbed by this linguistic blunder only
underscores the species's general lack of good sense.
However, this is not the only way in which the human mind is capable of
enshrining lack of intelligence. The fact that this particular statement
is repeated so often and is so often believed is proof positive that
something behind the scenes, as it were, must be going on to place humans
in their role on their home planet.
For dispassionate examination of the situations of humans and other
creatures would lead one to believe that dogs, while individually often
on friendly terms with humans, are as a collective not as friendly as
might be supposed. For example, it is well known, even among humans, that
a common source of the dangerous disease "rabies" is a bite from an
infected dog. Dogs are also common carriers of parasites dangerous to
humans. While many might dismiss these facts as "coincidences," an
observer might come to the conclusion that what appears to be "friendship"
on the part of "dog" towards "man" may, in fact, be a cunning species-wide
ingratiation program.
What species, then, would better qualify as the "best friend" of humanity?
Recent discoveries made by the humans leads one to believe that the "cat"
(felis catus, L.) may better deserve this title. The reason for this
conclusion is that humanity found itself confronted with a very perplexing
and fatal medical disorder, which they named "AIDS" (although it only
"aids" humans in their progress towards the grave). This syndrome was
characterized in the early-to-middle 1980s ("AD" Terran annuation system)
and was ultimately assigned to be an eventual result of a virus that was
given the name "human immunodeficiency virus" or HIV.
Feline immunodeficiency virus (FIV) is the causative agent of a feline
acquired immune deficiency syndrome (FAIDS) that was discovered in 1986 in
southern California (Pedersen et al, 1987; Yamamoto et al, 1988). The
associated infection tends to have a long asymptomatic seropositive stage
followed by clinical illness. Clinical signs include fever,
lymphadenopathy, diarrhea, wasting, opportunistic infection, neurological
disorder, and neoplasia, especially lymphoma, myoproliferative disease, and
various cytopenias including anemia, lymphopenia, and leukopenia (which may
not be due to the activity of FIV alone) neoplasia, especially lymphoma and
myoproliferative disease, (Hutson et al, 1991; Moraillon et al, 1992;
Pedersen et al, 1989a, b; Shelton et al 1991). Neoplastic effects of HIV
infection seem to be enhanced with concurrent FeLV infection (Hutson et al,
1991; Shelton et al 1991).
Clinical immunological effects include inversion of neutrophil to
lymphocyte cell ratio (Moraillon et al, 1992), probably due to preferential
infection of CD4 cells over CD8 cells, as clinical studies demonstrated a
reduction in CD4 but not CD8 lymphocytes (Tompkins, et al, 1991; Ackley et
al, 1990; Barlough, et al, 1991, Hoffmann-Fezer et al, 1992).
Interestingly, unspayed seropositive female cats showed significantly higher
CD4 counts and CD4/CD8 ratios than did males or spayed females (Hoffmann-
Fezer et al, 1992). In vitro studies have demonstrated that FIV infected
CD4 and CD8 T-lymphocytes and macrophages. However, different isolates
showed different relative affinities for each type of cell (Brown et al,
1991, Tokunaga et al, 1992). Macrophage function is also altered in vitro
in FIV infection (Lin and Bowman 1992). Isolates of FIV have shown
differences in vitro for adaptability to various cell lines and cell-type
tropisms (Kawaguchi, et al, 1991).
FIV has been found on five continents (Bandecchi et al, 1992; O'Connor
et al, 1991; Olmstead et al, 1992; Sukura et al, 1992; Yamamoto et al,
1989). Percentages of infection range from 7.4%-8% in indoor pets and 25%
in free-roaming cats in the United States (O'Conner et al, 1991; Yamamoto
et al, 1989), 24% in free-roaming cats in Italy (Bandecchi et al, 1992),
and 6.8% in Finland for free-roaming cats (Sukura et al, 1992). Feline
leukemia virus (FeLV) infection appears to accompany FIV infection in a
large percentage of these cases (Bandecchi et al, 1992; O'Connor et al,
1991; Olmstead et al, 1992; Sukura et al, 1992; Yamamoto et al, 1989).
In wild feline species, seropositivity to FIV or FIV-related viruses is
as high as 80%. However, these free-ranging large cats appear to be free
of pathologic signs (Olmstead et al, 1992).
Protein studies (Steinman et al, 1990, Kiyomasu et al, 1991) sequence
analysis (Olmstead et al, 1989), and deletion mutant analysis (Morikawa and
Bishop, 1992) demonstrate that FIV is a lentivirus (the same viral sub-
family which contains HIV) in that it possesses the classical lentivirus
genome arrangement of a 5' long terminal repeat, rev, gag, pol, and env
genes with small open reading frames (vif, etc.) between the pol and env
genes (Clements and Wong-Stall, 1992, Coffin, 1990; Narayan and Clements,
1990). However, genome arrangement and phylogenetic analysis of various
gene products indicate a closer genetic relationship to the ungulate
lentiviruses than to currently identified hominoid (human and simian)
immunodeficiency viruses (Olmstead et al, 1989, 1992).
Nevertheless, clinical signs of FIV infection are closer to those of
the hominoid viruses in their native hosts than to the ungulate viruses in
their native hosts (Fenner et al, 1987).
While work is going on to elucidate the disease mechanisms for HIV, the
information to be derived from this work, however valuable, will be limited
by the fact that an adequate animal model that manifests clinical signs
similar to human AIDS has yet to be discovered or engineered for HIV.
FIV, on the other hand, produces a clinical syndrome much like human AIDS
(CDC, 1987; Hirsch and Curran, 1990). Elucidation of the pathways of FIV
pathogenesis could permit design of drugs to block these pathways that could
then be more readily tested upon animals manifesting clinical disease than
could drugs derived from work directly upon HIV. Furthermore, domestic cats
are cheaper and easier to care for than are chimpanzees and maqacques
currently used for HIV and HIV-related research (not to mention the fact
that felis catus is hardly an endangered or threatened species). It is true
that the somewhat distant relationship between FIV and HIV might pose some
difficulties in directly transporting data back and forth. However, using
FIV as a model for the human disease will better permit workers to gauge
problems such as relative host toxicity of treatments derived from
information on assembly and packaging, collateral non-toxic host effects of
such treatments, etc. with more confidence than permitted by the limited
trials in animals that do not manifest immune deficiency signs.
Now, one would think that the "best friend" of "man" would have leapt into
the breach and developed a disease that could have been used to model such
a feared human malady. However, it seems that the much-maligned cat has
instead taken this role. Perhaps humanity might prove some vestige of
intelligence if they are able to take notice of this noble self-sacrifice
on the part of this small animal.
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