Brownstein, DG Genetically Engineered Mice: The Holes in the Sum
of the Parts. Laboratory Animal Science 48 (2): 121.
This is an editorial which describes some of the issues which laboratory
animal veterinarians should be concerned about when dealing with transgenic
mice. Suggests research needed into the peripheral effects of genetic
engineering. The author reflects on the less-emphasized aspects of
transgenic mice, namely the reproductive biology, embryology and genetics.
With the onset of transgenics 18 years ago in a report by J.W. Gordon et
al, an unprecedented share of biomedical research has relied on genetically
engineered mice. However, there is a scarcity of publications that
deal directly with the mice, due to lack of familiarity of the model
and the technology (according to the author).
Areas that need further investigation include: methodology to increase
fecundity, assessing lineage to understand the consequences of mixing
inbred mouse genomes, and assessing the consequences of allogeneic foster
pregnancies
Questions:
1. When and where was the first paper published on transgenic
mice?
Answer:
1. Gordon, J.W., G.A. Scangos, D.J. Plotkin, et al. 1980.
Genetic transformation of mouse embyros by microinjection of purified DNA.
Proc. Natl. Acaed. Sci. USA 77:7380-7384.
Primary and Opportunistic Infections in Retroviral Induced Immunosuppression
in Nonhuman Primates (Meeting Report) (B). Laboratory Animal Science 48
(2): 123.
The 29th Annual Primate Pathology Seminar and Workshop in Boston, Mass.
was hosted by the Registry of Comparative Pathology and the New England
Regional Primate Research Center (Feb. 28-March 1).
The majority of the presentations centered
on the manifestations ofSIV (Simian immunodeficiency virus) infection but
also included Simian retrovirus (SRV), Simian-human immunodeficiency virus
(SHIV), and human immunodeficiency virus (HIV). One speaker described
"inflammatory conditions associated with SIV infection, including arteropathy/arteritis,
multi-nucleate giant cell disease, and data associating chemokine and chemokine
receptor expression wtih the genesis of encephalitic lesions."
Data was presented on AIDs in an HIV infected chimpanzee.
Opportunistic infection of immunosuppressed
macaques were described. These included Pneumocystis carinii infection,
mycobacteriosis, cryptosporidiosis, rhesus cytomegalovirus infection, adenovirus
infection, and candidiasis. Enterocytozoon bieneusi in immunocompromised
macaques was discussed as related to the same pathogen which causes morbidity
and mortality in human AIDs patients.
"Potential nonhuman primate models of
AIDs-associated neoplasia were described." A herpesvirus of macaques
may be related to human herpesvirus 8 (HHV-8) which may cause Kaposi's
sarcoma, Castleman's diesease, and body cavity lymphoma. An Epstein-Barr
virus (EBV)-like virus related lymphosarcomas in SIV infected macaques
as a potential model of
HIV-associated lymphomas in humans.
Next year's meeting will precede the
United States-Canadian Academy of Pathology in San Francisco. For
details call Dr. O'Neill at the Registry of Comparative Pathology, Armed
Forces Institute of Pathology, Washington, D.C. 20306-0001.
For more information on covered subjects,
the following publications can be consulted:
"Development of AIDS in a Chimpanzee Infected
with Human
Immunodeficiency Virus Type I", Journal of Virology 71(5): 4086-4091,1997.
"Identification of an Enterocytozoon bieneusi-Like
Microsporidian Parasite in Simian-Immunodeficiency-Virus-Inoculated Macaques
with Hepatobiliary Disease", American Journal of Pathology 150(4): 1395-1405,
1997.
"A Herpesvirus of Rhesus Monkeys Related to
the Human Kaposi's Sarcoma-Associated Herpesvirus", Journal of Virology
71(12): 9764-9769, 1997.
No Questions.
Casebolt, DB, DJ Speare, and DG Brownstein Care and Use of Fish as
Laboratory Animals: Current State of Knowledge. Laboratory Animal Science
48 (2): 124.
This is an excellent article which is an overview of the use of fish
in the laboratory setting. Water quality, which must be defined based
on the individual species, stage of life, and research, is the most important
element of fish husbandry. Effective environmental control is essential
for effective disease control. Stocking density and rate of water
changes need to be considered together. When evaluating health records
of fish, keep in mind that certification for international trade does not
imply that the fish are healthy - only states they are free from diseases
important in international trade. Excellent chart of differential
diagnoses, but authors leave descriptions of diagnosis and treatment to
the available textbooks.
Questions:
1) Which of the following may have an effect on the physiological
aspects of growth?
a. Lighting intensity
b. Noise levels
c. Stocking density
d. Feed delivery systems and timing of delivery
e. All of the above.
2) Water is important to fish because it:
a. Provides their oxygen
b. Provides their food
c. Is thermoregulatory.
d. All of the above.
3) True of False: The adequacy of flow rates (liters/minute)
of water in a tank is generally viewed in the context of the upper concnetration
of metabolic oxygen (mgo2/kg fish/min) demand of the tank inhabitants.
4) List three factors which can cause stress to fish in laboratory
settings.
5) List three ways to decrease stress in fish in laboratory settings.
Answers:
1) E
2) D
3) True.
4) Handling, experimental manipulation, temperature fluctuations,
water-quality alternations, food availability, environmental noise, human
activity, stocking density, social pressure, viral infection, bacterial
infection, or parasitic infection.
5) Use anesthetics (like tricaine methanesulfonate), lower water
temps during transport and handling, add NaCl to freshwater fish tanks
(slow acclimation needed).
Use of polymerase chain reaction to diagnose a natural outbreak of
mouse hepatitis virus infection in nude mice (B). Laboratory Animal
Science 48 (2): 137.
MHV is a mouse-specific corona virus with
many strains. Natural infection with MHV in mature, immunocompetent
animals is often subclinical but in nude mice it could be a cause of a
fatal wasting disease. MHV has the potential to interfere with in
vitro and in vivo research.
This study describes a natural outbreak
of disease due to MHV infection in a colony of nude mice in which confirmation
of the diagnosis was pursued via serologic testing, histologic examination,
EM, and reverse transcriptase -PCR (RT-PCR). In this outbreak, nude
mice obtained from a commercial SPF source were maintained in a barrier
facility. Mice were used in tumor implantation study (prostate carcinoma).
The tumor cells had previously been passaged in other nude mice in Texas.
Nude mice implanted with the tumor cells developed wasting and diarrhea.
All sera tested were negative for antibodies to MHV and other agents.
Immunocompetent sentinels introduced into the room also tested negative.
Histopathologic findings provided a presumptive diagnosis with focal hepatic
necrosis and a few syncitia, also large multinucleate cells were seen in
colonic an nasal epithelium. EM results of hepatic tissues
were equivocal. The etiology was eventually confirmed by RT-PCR.
Virus was detected in one nude and one sentinel mouse. No virus was
detected in cell lines that had been injected into the mice, hence the
source of outbreak was unknown.
By detecting viral genome, PCR offers
an advantage over serologic testing in situations in which an antibody
response is unlikely, e.g infection in immunodeficient animals, in young
animals, and infection of cell cultures. It is also a rapid and highly
sensitive technique. Limitations of PCR include its inability to
provide retrospective evidence of infection because it requires the virus
to still be present in the specimen. Thus the need for complementary
conventional techniques still remains.
Questions:
1) Which of the following clinical signs can be seen grossly
in the livers of mice infected with MHV?
a. Multiple pale spots
b. Pitting of capsular surface
c. Fibrinous adhesions to surrounding structures.
d. A and C.
e. All of the above.
2) How does one eradicate MHV from a colony?
3) True or false: The BALB/c mouse would be the appropriate
sentinel for a nude mouse colony given their similar genetic backgrounds
and their susceptibility to diseases like MHV.
Answers:
1) E
2) Depopulation
3) True
Maggio-Price, L and others Diminished Reproduction, Failure to Thrive
and Altered Immunologic Function in a Colony of T-cell Receptor Transgenic
Mice: Possible Role of Citrobacter rodentium. Laboratory Animal Science
48 (2): 145.
A transgenic colony with known MHV infection experienced a significant
increase in mortality. Citrobacter rodentium and several Helicobacter
spp. were identified. The Helicobacter spp remained constant, even
after normal mortality rates had been re-established, therefore the authors
concluded that C. rodentium was the inciting agent. The authors were
able to use enrofloxacin to eliminate C. rodentium from affected animals
while rederiving via Ceasarian section. They saw decreased ascites
production during the interval where C. rodentium was present in the colony.
Questions:
1) Citrobacter rodentium is a _______ and is transmitted via
________.
Answers:
1) Gram negative rod; fecal-oral
Spontaneous Cholangiofibrosis in Long-Evans Cinnamon Rats:
a Rodent Model of Wilson's Disease (B). Laboratory Animal Science 48 (2):
156.
The Long-Evans Cinnamon (LEC) rat is a rodent model of Wilson's disease.
Wilson's disease in humans is caused by a deletion of the ATP7B gene which
is thought to affect copper transport. LEC rats lack the rat homolog of
the gene and subsequently develop ceruloplasmin deficiency, hepatic copper
accumulation, and hepatocellular injury. Cholangiofibrosis occurs
after cell injury.
Fifty-four LEC rats were studied at various ages
(5-113 weeks). Liver lesions were graded by the extent of involvement
of cholangiofibrosis. Metal analysis for copper and iron content
were made on liver samples. A positive correlation was
found between the grade of cholangiofibrosis and age of the rats.
Jaundice was observed earlier in females although cholangiofibrosis develops
at the same age in both sexes. Cholangiofibrosis was evident in all rats
by 27 weeks of age and the condition progressed with age. No statistically
significant correlations could be made between concentrations of copper
or iron and histologic grades. Hepatic accumulation of copper is
thought to be critical to the proper differentiation of cell along a biliary
lineage. Treatment with copper-chelating agents such as penicillamine
or trientine prevents the development of cholangiofibrosis.
Questions:
1. What are the pathologic changes in the liver of LEC rats?
2. A. What 3 substances can be administered to rats to
experimentally
induce cholangiofibrosis?
B. Where is the preferential localization
of furan?
3. What is the only inbred strain of rats that spontaneously develops
cholangiofibrosis?
Questions:
1) What compounds can be used to induce cholangiofibrosis is
rats on a choline-free diet?
a. Furan
b. Butter yellow
c. Ethionine
d. Alcohol
e. A, B, and C
f. All of the above
Answers:
1. Fatty change, aneuploidy, proliferation of sinusoidal and
mononuclear
cells, inflammatory infiltration of hepatic parenchyma,
hepatocellular
dropout, regeneration, and fibrosis
2. A. 1. furan
2. butter yellow
3. ethionine with a choline-free
diet
B. right caudate lobe of the liver
3. Long-Evans Cinnamon rat
Herbst, LH and others Turmorigenicity of Green Turtle Fibropapilloma-Derived
Fibroblast Lines in Immunodeficient Mice. Laboratory Animal Science 48
(2): 162.
This study found that GTFP-derived fibroblast could not be distinguished
from normal skin derived fibroblasts by morphology and growth characteristics
in vitro. This makes it possible to investigate the molecular basis
of cellular proliferation characterization of green turtle fibropapilloma.
Questions:
1. What is the genus and species of the green turtle?
2. What is the proposed reason why tumors grew on the footpads
and the pinna, but not on the flank?
3. What current models exist for assaying tumorigenicity of lower
vertebrate cells?
Answers:
1. Chelonia mydas
2. The decreased temperature of the extremities are more accommodating
for supporting growth of cells from poikilothermic species.
3. The anterior chamber of the eye of Rana pipiens has been used
to culture Lucke renal adenocarcinoma cells and irradiated Anolis carolinensis
have been used for tumorigenicity studies of cell lines from several lower
vertebrate species.
Lyme Borreliosis in Laboratory Mice (B). Laboratory Animal
Science 48 (2): 168.
Lyme disease in humans and other species is caused by infection with
Borrelia burgdorferi, a tick-borne spirochete. The disease course is usually
characterized by acute symptoms, followed by spontaneous remission and
episodic bouts of recurrence, although some patients may develop chronic
unremitting disease. B. burgdorferi has a broad natural host range.
It readily infects rhesus macaques, dogs, rabbits, guinea pigs, gerbils,
hamsters, rats and mice. Mice are the best characterized model system because
they are economical, genetically and microbiologically defined, susceptible
to disease at all ages, consistently develop heart and joint disease when
inoculated by syringe or tick-borne infection, and disease induction does
not require immunomodulation. There is a strong genetically determined
susceptibility to disease: C3H/He mice develop relatively severe heart
and joint disease; BALB/c mice develop mild heart and mild joint disease;
and C57BL/6 mice develop mild heart and joint disease. Genetically based
susceptibility to disease is apparently not immune mediated, since it is
also expressed in mice with severe combined immunodeficiency (SCID). The
tick Ixodes scapularis (a.k.a. I. dammini) is the vector of most North
American B. burgdorferi infections. Following inoculation of the spirochete
arthritis begins to evolve as early as 4 days and carditis by 7-10 days.
Disease-susceptible C3H mice develop grossly visible tibiotarsal periarticular
edema by 2 wks. Spirochetes are present in relatively small numbers but
can be readily visualized in target tissues, such as joints and heart,
during the acute phase of infection with a variety of methods, including
silver stains, immunohistochemistry, or in situ DNA hybridization. The
disease-resolution phase, which occurs after 30 days, requires functional
immunity, as SCID mice, lacking T and B cells, develop persistent active
carditis and progressively severe arthritis , with intense synovial proliferation
and pannus of joints.
The host immune response is primarily humoral.
Studies of cellular immune responses are hampered by a nonspecific B-cell
mitogenic effect of B. burgdorferi and its outer surface lipoproteins.
The normally disease-resistant C57BL/6 mice can be converted to full disease
susceptibility with the single beige (Chediak-Higashi) mutation. Beige
mice lack functional NK cells and granulocytes. Lyme borreliosis has many
clinicopathologic features in common with the human disease. One of the
differences is that the mouse model does not seem to exhibit neurologic,
dermatologic, or chronic unremitting arthritic lesion.
Questions:
1) What causes Lyme disease?
2) Which strain develops severe heart and joint disease?
3) Which strain develops severe heart, but mild joint disease?
4) Which strain develops mild heart and joint disease?
Answers:
1) Borrelia burgdorferi, a tick-borne spirochete
2) The C3H/He strain
3) The BALB/c strain
4) The C57BL/6 strain
Questions:
1. List three reasons why mice are the best characterized model system
of
Lyme disease.
2. What is the most common tick species, which is the vector of most
North
American B. burgdorferi infections.
3. Name three methods which can be used to visualize the spirochete
in
target tissues?
4. The normally disease-resistant C57BL/6 mice can be converted to
full
Lyme disease susceptibility with what mutation?
Answers:
1. Mice are the best characterized model system because they are
economical, genetically and microbiologically defined, susceptible
to
disease at all ages, consistently develop heart and joint disease when
inoculated by syringe or tick-borne infection, and disease induction
does
not require immunomodulation.
2. The tick Ixodes scapularis (a.k.a. I. dammini) is the vector of
most
North American B. burgdorferi infections.
3. Silver stains, immunohistochemistry, or in situ DNA hybridization.
4. The single beige (Chediak-Higashi) mutation. Beige mice lack functional
NK cells and granulocytes.
Litwak, KN, WT Cefalu, and JD Wagner Strptozotocin-Induced Diabetes
Mellitus in Cynomolgus Monkeys: Changes in Carbohydrate Metabolism,
Skin Glycation, and Pancreatic Islets. Laboratory Animal Science 48 (2):
172.
Spontaneous adult-onset diabetes mellitus in NHP is an excellent model
of human disease (both associated with increased age and obesity, changes
in carbohydrate metabolism, variable changes in plasma lipids and lipoprotein
concentrations), but the slow development and low frequency of occurrence
limits its usefulness. Streptozotocin was used to induce diabetes.
Streptozotocin induces a state of chronic hyperglycemia due to its toxic
effect on pancreatic beta cells. Chronic hyperglycemia leads to glycation
of numerous proteins. Glycation products result in advanced glycated end
products (AGE). These events may contribute to the chronic diseases associated
with diabetes. The authors wanted to determine if this model could be used
to study mechanisms of diabetes associated cardiovascular disease.
Parameters followed included
blood glucose, glucose tolerance, glycated hemoglobin levels, skin AGE
levels, plasma total cholesterol, HDL-C, VLDL, LDL-C, and TG, and tissue
histopathology. Two months following STZ, monkeys were glucose intolerant,
had increased glucose, glycated hemoglobin, and skin AGE levels. Glycation
of hemoglobin equilibrates with ambient glucose concentrations, whereas
skin AGE content increases over time in both diabetic and non-diabetic
subjects and is considered an index of aging. No change in any cholesterol
levels was seen as long as glycemia was controlled, similar to humans with
well controlled type-1 diabetes. No visible changes in islet structure
were seen but insulin immunostaining decreased. This is expected in light
of the fact that STZ causes dose-dependent damage and not autoimmune insulitis.
By using a lower dosage of STZ the authors were able to induce a model
of chronic hyperclycemia, void of negative hepatic and renal effects, with
minimal changes in lipid or lipoprotein concentrations, and concluded that
this would be a useful model for studying its relationship with cardiovascular
disease.
Questions:
1. What other disease has STZ been used to study in NHP?
2. List 4 conditions induced by vascular changes associated with diabetes
mellitus and chronic hyperglycemia.
3. True or false: The percentage of islet insulin staining and physiologic
responses to the IV glucose tolerance tests showed a high level
of
correlation in all monkeys tested.
4. True or false: Insulin deficiency causes an increase in lipoprotein
lipase activation.
Answers:
1. Atherosclerosis
2. Nephropathy, retinopathy, neuropathy, and vasculopathy.
3. True
4. False
Hypoxanthine Phosphoribosyltransferase cDNA in Gerbils (Meriones
unguiculatus). Laboratory Animal Science 48 (2): 179.
Hypoxanthine Phosphoribosyltransferase (HPRT) is a purine salvage enzyme
that catalyzes conversion of hypoxanthine and guanine to their respective
mononucleotides. Biosynthesis of purine and pyrimadine nucleotides is a
crucial process in all growing cells because these molecules are the direct
precursors of DNA and RNA. Constitutive expression of the mRNA for HPRT
has been exploited for the use as an internal control in reverse transcriptase-polymerase
chain reaction (RT-PCR) quantification of cytokine roduction because of
its ubiquitous nature. Mammalian HPRT genes have been cloned and sequenced
for the molecular analysis of Lesch-Nyhan and gouty arthritis caused by
a deficiency of this enzyme. This paper describes the cloning and sequencing
of gerbil HPRT cDNA and the discovery of two unique forms of the cDNA.
Having these cloned genes available for the gerbil can be used to determine
the pattern of cytokine gene expression in the gerbil (jird). Gerbils are
used as models for a variety of diseases, including infection with Helicobacter
pylori, Schistosoma mansoni,
Acanthocheilonema vitae and Brugia pahangi.
Questions:
1. Deficiency of the mammalian HPRT enzyme causes what two diseases?
2. List three diseases in which gerbils are used as models.
Answers:
1. Lesch-Nyhan and gouty arthritis are caused by a deficiency of this
enzyme.
2. Helicobacter pylori, Schistosoma mansoni, Acanthocheilonema vitae
and
Brugia pahangi
"Absence of a Significant Mixed Lymphocyte Reaction in
a Marsupial (Monodelphis domestica)". Laboratory Animal Science 48 (2):
184.
In a previous study it was suggested that the marsupial Monodelphis
domestica failed to exhibit a mixed lymphocyte reaction (MLR) with allogeneic
lymphocytes. This study was to see if this was a matter of a response
too weak to detect but capable of being augmented by immunization.
The results of this study plus other studies with other marsupials, strongly
indicate that the failure to have a significant MLC response is a
general feature of marsupials. This suggestion seems to fit with
the accepted view that marsupials tend to have a more primitive immune
response than do eutherian mammals. It is generally accepted that
the MLC response is a measure of T-cell function in concert with genetic
polymorphism at the major histocompatibility (MHC) class-II loci.
Some studies suggest that a lack of polymorphism at the class-II MHC locus
accounts for the lack of MLC response. This study provides information
that this is not the case in M. domestica. It was shown that there
is polymorphism at the class-II locus in M. domestica. Further molecular
studies are being conducted.
"It seems likely that the failure of this species to exhibit a significant
mixed lymphocyte response is due to T cells whose ontogeny differs from
that of the T cells of eutherian mammals".
Questions:
1. Define "kinship coefficients"
2. The immune responses of M. domestica are very similar to what
type of mouse?
3. What is the genus a species of a. koala
b. tammar wallaby
Answers:
1. A measure of the genetic relatedness between two animals
2. a mouse lacking alpha/beta T cells due to a targeted mutation
in the T-cell receptor at the beta locus
3. a. Phascolarctos cinereus
b. Macropus eugenni
Diagnostic Exercise: Lethal Pneumonia in Neonatal Kittens.
Laboratory Animal Science 48 (2): 190.
Approximately 2 weeks after birth, a litter of two kittens born
to a primipara queen used in a fetal alcohol syndrome study developed acute
respiratory distress and died within 24 - 48 hours. Gross necropsy
findings were congested and consolidated cranial lung lobes. Histopathology
of this tissue revealed that the bronchial and bronchiolar epithelium was
necrotic, the lumens contained variable amounts of cellular debris, fibrin
and neutrophils. There was multifocal patchy necrosis of alveoli,
with flooding of lumens with fibrin and cellular debris. Nuclei of
airway epithelial cells contained eosinophilic inclusions surrounded by
a rim of marginated chromatin.
The diagnosis was infection with feline herpes virus, which can
rarely cause severe fatal pulmonary disease characterized by necrotizing
bronchitis, bronchiolitis, and pneumonia, with serofibrinous flooding of
alveoli and airways in young kittens. In this case the mother was
likely a carrier that had a recrudescence and viral shedding because of
the stress of pregnancy and in turn infected her young kittens.
Questions:
1. List 6 differential diagnosis for feline pneumonia.
2. What are 2 metazoan parasites that can infect the feline
lung?
Answers:
1. viral, bacterial (including Chlamydia) , fungal,
protozoan parasites, metazoan parasites, foreign body/aspiration.
2. Aelurostrongylus obstrusus and Paragonimus kellicotti
Further Evaluation of a Diagnostic Polymerase Chain Reaction Assay
for Pasteurella pneumotropica. Laboratory Animal Science 48 (2): 193.
This article summarizes the evaluation of PCR for Pasteurella
pneumotropica by using primers PPN-1 and PPN-2. Test DNA had been
extracted from bacterial suspensions via boiling, precipitation of lysoszyme
and proteinase K digests, via CTAB/NaCl purification methods followed by
RNAse I digestion and reprecipitation. All P. pneumotropica reference
strains and field isolates were identified by PCR; however, Actinobacillus
muris also had positive results. A. muris disappeared when
the annealing step was increased from 55 deg. C to 57 deg. C. A.
muris has been isolated from conjunctiva, oropharynx, and lower respiratory
tracts of mice, with or without evidence of inflammation. The use
of PCR may definitively identify Pasteurella pneumotropica and differentiate
it from Actinobacillus muris.
QUESTIONS:
1. Pasteurella pneumotropica is a gram-negative coccobacillus
harbored
by:
a. laboratory rats
b. mice
c. hamsters
d. guinea pigs
e. other rodents
f. a., b., & c.
g. a. thru e.
2. PCR assays have higher specificity than do traditional diagnostic
methods and save technician time and large amounts of biochemical reagents
required to distinguish it from related bacteria of which complex:
a. Haemophilus-Pasteurella-Streptococcus
b. Haemophilus-Pasteurella-Bordatella
c. Haemophilus-Pasteurella-Actinobacillus
d. Streptococcus-Pasteurella-Actinobacillus
d. Streptococcus-Pasteurella-Bordatella
3. Define the Acronyms:
a. PCR
b. RAPD-PCR
c. CTAB
d. NIEHS
e. ATCC
4. By varying components of the PCR assay and keeping other factors
constant, cross-reactivity with Actinobacillus muris disappeared
when the
a. Annealing step was increased
from 55 deg. C to 60 deg. C.
b. Denaturation step was
decreased from 94 deg. C. to 90 deg C.
c. Extension step was increased
from 72 deg C. to 75 deg C.
d. Denaturation step was
increased from 94 deg. C. to 98 deg. C.
e. Annealing step was increased
from 55 deg. C. to 57 deg. C.
ANSWERS:
1. Pasteurella pneumotropica is a gram-negative coccobacillus
harbored by:
g. laboratory rats, mice,
hamsters, guinea pigs, and other rodents.
2. PCR assays have higher specificity than do traditional diagnostic
methods and save technician time and large amounts of biochemical reagents
required to distinguish it from related bacteria of which complex:
c. Haemophilus-Pasteurella-Actinobacillus
3. Define the Acronyms:
a. PCR
Polymerase Chain Reaction
b. RAPD-PCR
Randomly Amplified Polymorphic DNA - Polymerase Chain
c. CTAB
Cetyltrimethylammonium Bromide
d. NIEHS
National Institute of Environmental Health Sciences
e. ATCC
American Type Culture Collection
4. By varying components of the PCR assay and keeping other factors
constant, cross-reactivity with Actinobacillus muris disappeared
when the
e. Annealing step was increased
from 55 deg. C. to 57 deg. C.
Comparison of Bile Chemistry Between Humans, Baboons, and Pigs: Implications
for Clinical and Experimental Liver Xenotransplantation. Laboratory Animal
Science 48 (2): 197.
Despite the immunologically encouraging results of two baboon-to-human
liver transplants, both of the grafted baboon livers
developed cholestasis (sludging) in the common bile duct. Pig liver
is rejected rapidly in non-human primates with a maximal survival of only
3 days. With the emphasis on developing a successful porcine xenotransplant
model, the etiology of ôsludgingö from baboon-human model
must be elucidated. This paper examines gallbladder and hepatic bile
of humans, baboons, and pigs to determine viscosity, pH, bilirubin, cholesterol,
and electrolyte concentrations.
No significant differences
in gallbladder viscosity, pH, cholesterol, Na, Cl, HCO3, and P concentrations
in the pig, baboon, and human.
QUESTIONS:
1. How was viscosity measured?
2. In gallbladder bile mean K, Ca, and bilirubin concentrations
were (higher, lower) (chose one) than in baboons, and mean Ca, Mg, and
total and indirect bilirubin were (higher, lower) (chose one) in humans
than in pigs. Cholyglycine values varied widely within each species
but were highest in (humans, baboons, pigs) (chose one).
3. In liver bile, viscosity, cholesterol, Na, K, Ca, Mg, and total
bilirubin were significantly (higher, lower) (chose one) in humans than
in (baboons, pigs) (chose one).
4. In liver bile, cholyglycine values were (lower, higher) (chose one)
in baboons compared to humans and pigs.
5. Both grafted baboon livers in clinical xenotransplantation contained
inspissated bile ("sludge") in the (gallbadder, bile duct, extrahepatic
tissues) (chose one).
6. If you received a liver transplant from a baboon, would you also
receive the baboon's gallbladder?
7. Were there any differences found in gallbladder or hepatic bile
which would account for the sludging of bile produced by baboon or pig
livers in humans or by pig livers in baboon? What might account for
the sludging?
ANSWERS:
1. How was viscosity measured?
Capillary Flow viscometer
2. In gallbladder bile mean K, Ca, and bilirubin concentrations
were higher than in baboons, and mean Ca, Mg, and total and indirect bilirubin
were higher in humans than in pigs. Cholyglycine values varied widely
within each species but were highest in baboons.
3. In liver bile, viscosity, cholesterol, Na, K, Ca, Mg, and total
bilirubin were significantly higher in humans than in baboons.
4. In liver bile, cholyglycine values were higher in baboons compared
to humans and pigs.
5. Both grafted baboon livers in clinical xenotransplantation contained
inspissated bile ("sludge") in the bile duct.
6. If you received a liver transplant from a baboon, would you also
receive the baboon's gallbladder? No, because a cholecystotomy is
performed during the transplantation.
7. Were there any differences found in gallbladder or hepatic bile
which would account for the sludging of bile produced by baboon or pig
livers in humans or by pig livers in baboon? No What might
account for the sludging? Human environment alter the character of bile
after xenotransplantation, or immunologic factors may play a role.
Modified Technique for Abdominal Heterotopic Cardiac Transplantation
in the Rabbit. Laboratory Animal Science 48 (2): 201.
Heterotopic cardiac transplantation has been used to evaluate complications
of transplant procedures, evaluate new drugs, and study the pathogenesis
of graft survival. Techniques for abdominal heterotopic cardiac transplant
have been described including end-end anastomosis (donor aorta and pulmonary
artery to recipient abdominal aorta and CVC at the level of the renal vessels)
which resulted in paraplegia and paralysis and an improved end-side anastomosis.
The end-side anastomosis resulted in 100% incidence of paralysis in rabbits
weighing > 1 kg. This article describes a modified cross clamp technique
that resulted in no signs of spinal cord ischemia in the 41 rabbits used
during this study. The improved cross clamp technique makes the abdominal
heterotopic cardiac transplant a valuable and reliable tool for further
studies in transplantation.
No questions
Doppler Echocardiographic Analysis of Effects of Tribromoethanol
Anesthesia on Cardiac Function in the Mouse Embryo: A Comparison
with Pentobarbital. Laboratory Animal Science 48 (2): 206.
This article compared doppler echocardiography in pregnant female mice
anesthetized with either tribromoethanol (TBE) or pentobarbital sodium
(PB). TBE induced transient arrhythmia in mouse embryo hearts mainly
between days 11 and 13 of gestation. This suggests that the mouse
embryo heart is especially vulnerable to the anesthetic during this period.
There was no arrhythmia in the PB group of embryos. The heart rate
in the TBE group was slower than in the PB group. (TBE) has been an extensively
used anesthetic in research involving mice because of its rapid onset of
effect, wide range of tolerance, and low mortality. They concluded that
TBE can induce arrhythmias and/or can inhibit the conduction at these developmental
stages.
Questions:
1. What anesthetic induced arryhthmias
in mouse embryo hearts?
2. TBE induced transient arrhythmias
in mouse embryo hearts between days
a.1-3
b. 4-6
c. 7-9
d. 11-13
Answers not provided.
Detection of Mycoplasma pulmonis from Rats and Mice of Sao Paulo/SP,
Brazil. Laboratory Animal Science 48 (2): 210.
Mycoplasma infection of the respiratory tract is a major disease entitiy
in laboratory rats and mice. As well, Mycoplasma can cause joint
and vaginal infections. Mycoplasma infection can cause significant
interference with experimental data and lead to potential misinterpretation
of the data.
One barrier-maintained facility was found to have
no mycoplasma (by culture of tracheobronchial lavage or ear flushing samples);
however all of the conventional facilites were found to have a high positive
culture rate. Tracheobronchial lavage was a more reliable technique.
Facility refurbishment and hygiene controls failed to eliminate M. pulmonis
infection in 3 facilties.
No Questions