Effects of Varying Storage Time and Temperature on Stability
of Complete Blood Count Measures. Contemporary Topics 37 (6): 52.
It is generally accepted that most diagnostic specimens should be for
hematologic analysis. When collecting samples from a large number of animals
at a time, there is often a delay of one to several hours before specimens
can be managed. Blood samples were collected from mice, rats, rabbits,
and monkeys into tubes containing EDTA for complete blood counts. Several
samples were collected from each animal and the tubes were subjected to
varying time and temperature conditions before analysis. Specimens were
immediately refrigerated, maintained at ambient temperature for 6 hr and
then refrigerated, or maintained at ambient temperature until analyzed.
Complete blood counts were conducted 2, 6, 24, 30, and 48 h after specimens
were obtained and compared with counts conducted immediately after sample
collection. All specimens were suitable for analysis. Whether immediately
refrigerated, maintained at ambient temperature prior to refrigeration,
or maintained at ambient temperature for up to 48 h, samples had consistent
values for leukocyte counts, erythrocyte counts, hemoglobin concentration,
and hematocrit. These results indicated that immediate refrigeration is
not absolutely necessary when performing complete blood counts on EDTA-fixed
blood samples and that properly collected blood samples stored at ambient
temperature can provide adequate data for up to 48 h after collection.
QUESTIONS:
1) What are the correct units for reporting the hemaglobin concentration
(HGB) ?
a) g/l
b) g/dl
c) mg/dl
d) %
1) Which of the following anticoagulants does NOT work by complexing
calcium ions required in the clotting mechanism?
a) Sodium citrate
b) Heparin
c) EDTA
d) Sodium oxylate
ANSWERS:
1) b, g/dl
2) b, heparin. Heparin (from the Greek hepar, "liver) prevents blood
coagulation by complexing with antithrombin III and potentiating the ability
of antithrombin III to neutralize the action of thrombin and activated
coagulation factors XII, XI, IX, and X.
Schalm's Veterinary hematology, 4th ed, Pg. 22
Monoclonal Antibody Production in Gas-Permeable Flexible Flasks,
Using Serum-Free Media. Contemporary Topics 37 (6): 55.
The authors evaluate the feasibility of flexible, gas-permeable tissue
culture flasks (GPF) as an alternative in vitro technique for small-scale
monoclonal antibody (Mab) production. Various culture conditions were evaluated,
including type of culture media, seeding density, and addition of commercially
available media supplements designed to enhance Mab production. Cultures
grown in GPF were also compared with cultures grown in traditional rigid
tissue culture flasks seeded under identical conditions.
Traditional methods of Mab production involve in vivo cultivation of
hybridomas in the form of ascitic tumors in the peritoneal cavities of
mice. Inherent problems with the use of mice are: availability of laboratory
animal facilities, unpredictability of establishing ascitic tumors, contamination
of ascites with other murine proteins, solid tumor formation, premature
mortality, batch variation and ethical concerns regarding animal use. In
order to diminish need for mice in hybridoma production other methods have
been produced: culturing in rigid tissue culture flasks or roller bottles,
fermentors, hollow fiber units, oscillating bubble chambers and dialysis
tubing. Many of these in vitro methods of hybridoma culture for Mab production
require the use of serum supplements in the growth medium. Serum is a complex
mixture that contains growth factors necessary for long-term culture of
hybridoma as well as other cell lines. Growth medium supplemented with
serum may cause problems in Mab purification due to contaminating serum
proteins. In this study the use of GPF with serum -free media or media
supplements designed specifically for enhancement of Mab production was
explored.
Mab production and cell concentration were greatest for cultures grown
in GPF at seeding densities greater than 1 X 10^6 live cells/ml. In 3 of
the 4 hybridomas tested, cultures grown in GPF produced 1.3-5.1 times more
Mab per ml, compared with cultures grown in rigid flasks. All Mab were
functional, as determined by their respective immunoassays. The GPF produced
less antibody per milliliter of culture fluid than mice; however, total
antibody yield obtained after concentration of culture media are comparable.
When compared with traditional tissue culture flasks, GPF produced more
total antibody while using less incubator space and labor. All serum-free
media resulted in better monoclonal antibody production, compared with
the same cells grown in RPMI medium supplemented with fetal bovine serum.
The use of GPF is a reasonable alternative to the use of mice for small-scale
Mab production, with additional reductions in the use of animal products
through use of serum-free media.
Questions:
1. Which of the following can be inherent problems with in vivo cultivation
of hybridomas in the form of ascitic tumors in the peritoneal cavities
of mice?
a. availability of laboratory animal facilities
b. unpredictability of establishing ascitic tumors
c. contamination of ascites with other murine proteins
d. solid tumor formation
e. premature mortality
f. batch variation
g. ethical concerns regarding animal use
2. Name 3 in vitro methods of culturing for Mab production?
3. Growth medium supplemented with serum may cause problems in Mab
purification due to contaminating____________________.
Answers:
1. a,b,c,d,e,f,g
2. culturing in rigid tissue culture flasks or roller bottles, fermentors,
hollow fiber units, oscillating bubble chambers and dialysis tubing
3. Growth medium supplemented with serum may cause problems in Mab
purification due to contaminating serum proteins.
Evaluation of Post-Operative Analgesics in a Model of Neuropathic
Pain. Contemporary Topics 37 (6): 61.
Neuropathic pain is a type of moderate to sever chronic pain that,
unlike acute pain, serves no protective function. It typically occurs subsequent
to nerve injury. There are three validated animal models of neuropathic
pain, the Chung, the Bennett, and the Seltzer models. This study utilized
the Chung model. The surgical procedure involved a tight ligation of the
L5 spinal nerve, resulting in an allodynic response to a mechanical stimulus
within 12-24 hours. The present study was used to evaluate the use of post-operative
analgesics in this model and determine whether post-operative analgesics
delay development of mechanical allodynia in the rat. 76 8-week-old Sprague-Dawley
rats were utilized, each weighing 175-200 gm. After the Chung procedure
the rats were randomly assigned one of 5 treatment groups; oxymorphone,
buprenorphine, carprofen, EMLA, or saline (control). Mechanical allodynia
was assessed according to a method previously described by Chaplan et.
Al. On days 1, 3, 8, 10, and 14 post-operatively, rats were individually
placed in a Lucite testing chamber with wire mesh bottom. Von Frey hairs
having a force ranging between 0.41g and 15.1 g were applied to the mid-plantar
left hind paw, starting with the 2 g middle air. A response was deemed
positive if the paw was sharply withdrawn. If a positive response was observed,
the next finer hair in the series was a applied. If no response, the next
coarser hair. Testing continued until the last of the series of hairs was
used or a threshold was reached. Under normal conditions a rat can withstand
greater than 15 g of force to the mid-plantar region without withdrawing
it. After the nerve ligation, mechanical allodynia occurs in the ipsilateral
paw in 65-70% of the animals. The onset occurs as early as 24 hours after
surgery and peaks between 7-14 days, remaining an average of 2 months.
Study results showed that EMLA cream did not alter the onset or time course
of development of mechanical allodynia. However the majority of animals
treated systemically with either an opioid agonist, agonist/antagonis,
or nonsteroidal anti-inflammatory agent showed an insensitivity to mechanical
stimuli during treatment. This insensitivity was most consistently observed
at 3 days post-op. It was not known whether lack of response was a result
of delayed onset of the mechanical allodynia, or whether the drugs provided
more than adequate analgesia. Most of the previous insensitive animals
were demonstrating lower PWT on day 8 post-op, 4 days after drug treatment
ended. On day 14 post-op, the expected 65-70% of animals had a PWT below
4 g in all groups. Therefore, the conclusion was that the analgesics used
in the study can be administered post-op without interfering with the model
development. Choice of analgesics will be dependent on study design.
Questions:
1. List three validated models of neuropathic pain.
2. What is the maximum force, under normal conditions, to the mid-plantar
region of the hind paw that a rat can withstand?
3. True or False Neuropathic pain serves a protective function.
4. In the Chung model, what percent of rats will develop mechanical
allodynia?
Answers:
1. Chung, Bennett, and Seltzer
2. > 15 g
3. False Neuropathic pain serves no protective function and is usually
associated with resolution of a nerve injury.
4. 65-70%
Assessment of Occupational Exposure to Isoflurane Administered in
an Anesthetic Chamber Within a Horizontal Laminar Flow Clean Bench. Contemporary
Topics 37 (6): 64.
Exposure to isoflurane administered in serveral semi-open chambers
within a horizontal laminar flow clean bench without a gas-scavenging system
was studied. Five or six (one died when masked with isoflurane) Swiss Webster
Mice were anesthetized in three anesthetic chambers of different dimensions
with loose fitting or tightly fitting lids. Gas concentrations were determined
while pouring anesthetics and while anesthetizing these mice at the exhaust
port and at the operator level. There were no significant differences between
the chambers; however, peak concentrations of isoflurane did not exceed
0.7 ppm. The author concludes that use of the anesthetic via these chambers
should be administered through a properly exhausted biosafety cabinet or
fume hood to minimize exposure and that a gas scavenging system be used
with a laminar flow clean bench. Chamber size wtih the smallest possible
opening and pre-loading isoflurane in a fume hood was recommended.
QUESTIONS:
1. Name that Acronym:
a. OSHA
b. NIOSH
c. ACGIH
d. DEHS
e. STEL
f. ALARA
g. TWA
2. What is 1-chloro-2,2,2-trifluroroethyl difluoromethyl ether?
3. Name an inhalant anesthetic with higher solubility in blood than
isoflurane. Name two anesthetics with lower solubility in blood than isoflurane.
4. What type of instrument was used to measure the ppm of isoflurane?
5. True or False - Isoflurane has never produced fulminant hepatic
failure following anesthesia.
ANSWERS:
1. Name that Acronym:
a. OSHA - Occupational Health and Safety Administration
b. NIOSH - National Institute of Occupational Safety and Health
c. ACGIH - Ametican Conference of Governmental Health and Safety
d. DEHS - Department of Environmental Health and Safety
e. STEL - Short-Term Exposure Limit
f. ALARA - As Low As Reasonably Acceptable
g. TWA - Time Weighted Average - or Trans World Airlines
2. What is 1-chloro-2,2,2-trifluroroethyl difluoromethyl ether?
Isoflurane
3. Name an inhalant anesthetic with higher solubility in blood than
isoflurane. Methoxyflurane
Name two anesthetics with lower solubility in blood than isoflurane.
Desflurane and Sevoflurane
4. What type of instrument was used to measure the ppm of isoflurane?
Infrared Detectors (MIRAN model 1B2, Foxboro, East Bridgewater MA).
5. False - Isoflurane has produced one reported case of fulminant hepatic
failure following anesthesia.
Chronic Cecal Cannulation in Yucatan Miniature Swine. Contemporary
Topics 37 (6): 68.
This article describes at very interesting technique which will permit
microbiological sampling of cecal contents for organisms such as Campylobacter
or Salmonella in fully awake Miniature Yucatan Swine. The anesthesia consisted
of an Ace-Ketamine induction, masking with Isoflurane, intubation, and
maintenance with Isoflurane and a Nitrous Oxide:Oxygen (2:1)combination.
The cecum was approached through a ventral midline incision and the cannula
was placed through an incision at the avascular plane (to avoid the tenia)of
the cecum close to the ileo cecal junction. The intratulumenal tubular
end was secured in the cecum with 2 3-O PDS purse string sutures. A felt
cuff was sutured to the serosa of the cecum with 3-O nylon. The barrel
of the cannula was exteriorized through the lateral abdominal wall and
secured with 2-O PDS to the muscle. The ventral midline incision was closed
with 2-O PDS in the muscle and subcutis and 3-O PDS for subcuticular closure
of the skin. Buprenorphine was administered for post-operative analgesia.
QUESTIONS:
1. What was the cannula's composition?
2. What were the 3 layers of the cannula?
3. What was the failure time for flexible T-tubes for cecal cannulation?
4. What was the shortest failure time for the rigid epoxy-filled polyurethane
cannula? What was the longest survival time of the rigid epoxy-filled polyurethane
cannula?
5. What does PDS stand for?
6. What is the advantage for miniature swine use in cecal cannulation?
7. What are complications that are reported for flexible cecal cannulations?
ANSWERS:
1. What was the cannula's composition? Rigid Epoxy-Filled Polyurethane
Cannula
2. What were the 3 layers of the cannula?
a. intralumenal portion - secured in the cecum with a purse-string
suture
b. felt cuff - sutured to serosa of the cecum
c. outer end of the barrel - externalized through the lateral abdominal
wall
3. What was the failure time for flexible T-tubes for cecal cannulation?
< 13 weeks
4. What was the shortest failure time for the rigid epoxy-filled polyurethane
cannula? What was the longest survival time of the rigid epoxy-filled polyurethane
cannula?
206 days, > 1 year
5. What does PDS stand for?
polydiaxonone
6. What is the advantage for miniature swine use in cecal cannulation?
The miniature swine have a lower growth rate than do domestic breed
Thus, the growth of the thickness of the abdominal wall would result
in a lower cannula failure rate.
7. What are complications that are reported for flexible cecal cannulations?
a. growth in thickness of the abdominal wall
b. chronic inflammation of the skin
c. intestinal torsion
d. peritonitis
e. evisceration
Comparison of Two Sanitation Monitoring Methods in an Animal Research
Facility. Contemporary Topics 37 (6): 71.
RODAC plates and a bioluminescent ATP detection monitoring device (Charm
Luminator-K and PocketSwab by Charm Sciences Inc., Malden, MA) were compared
in side-by-side tests on an animal room floor and on cages (stainless steel).
RODAC plates detect the presence of live microorganisms after a 48-h incubation
period. ATP tests detect any organic matter in 10 min. A cost-analysis
resulted in significant cost savings of ATP tests due to the reduced time
necessary to perform the test. Also, ATP test is a test of cleanliness
instead of detecting only the presence or absence of live bacteria and
fungi as with the RODAC plates.
QUESTION
1- Give the meaning of the acronym RODAC, ATP, OPRR, and RLU.
ANSWER
Replicate Organism Detection And Counting plates
Adenosine TriPhosphate
Office for Protection from Research Risks
Relative Light Units
The Use of a Thermoplastic Cap to Protect Against Self-Induced Trauma
in a Nonhuman Primate. Contemporary Topics 37 (6): 75.
A rather ingenious techniqe to protect against self-induced trauma
of head lesions. A perforated thermoplastic (Orthoplast II) was heated
to 150-170 degrees F in a water bath (non-stick electric skillet) to make
it pliable. The material decreased in elasticity as it cooled but was still
malleable and confortable to the touch. With the monkey anesthetized, the
plastic cap was molded to the skull. The cap was attached to the skull
with a titaniumhead post and a single screw with a broad head. A space
of approximately 3-5 mm was left between the monkey's head adn the cap
for ventilation and multiple holes were drilled ~1.5-in apart. This cap
could be changed, removed, or modified in chaired awake (for cooperative
)or Ketamine anesthetized (for uncooperative) rhesus monkeys. Heat guns
were used to re-shape the cap. The cap was cleaned with warm water and
2% chlorhexidine.
QUESTIONS:
1. What is the genus and species of the rhesus monkey?
2. The cap was secured to the monkeys head by:
a. acrylic base and two layers of suture
b. two layers of suture with the last layer as a subcuticular pattern
c. methylmethacrylate application between the cap and the head
d. threaded titanium head post by using a single screw with a broad
head.
e. sutures and wound clips
3. (True or False) Thermoplastic rapidly decreases in elasticity as
the material cools, but it is still pliable when the surface of the material
is at a temperature that is comfortable to the touch.
4. The post-operative care included:
a. buprenorphine
b. actaminophen
c. trimethoprim
d. sulfamethoxazole
e. all of the above
f. none of the above
5. At what temperature should one heat the thermoplastic?
a. 100-120 degrees F
b. 120-150 degrees F
c. 150-170 degrees F
d. 170-180 degrees F
e. >180 degrees F
ANSWERS:
1. What is the genus and species of the rhesus monkey?
Macaca mulatta
2. The cap was secured to the monkeys head by:
d. threaded titanium head post by using a single screw with a broad
head.
3. True Thermoplastic rapidly decreases in elasticity as the material
cools, but it is still pliable when the surface of the material is at a
temperature that is comfortable to the touch.
4. The post-operative care included:
a. buprenorphine
b. actaminophen
c. trimethoprim
d. sulfamethoxazole
=>e. all of the above
5. At what temperature should one heat the thermoplastic?
c. 150-170 degrees F
A Method for Promoting Regular Exercise in Rabbits Involved in Orthopedics
Research. Contemporary Topics 37 (6): 77.
A method was developed to train rabbits to exercise regularly. Flemish
Giant rabbits were trained to run on a modified commercial treadmill. Oat
cereal (cheerios) was used as an incentive. Rabbits were eventually run
at 0.3mph for 10 min./day, five days/week for up to 2 years without injury.
An important part of the early training was acclimating the animals
to the noise of the running treadmill. Consistency of trainer and training
was stressed. The animals were first accustomed to the cereal in their
cage, then on a stationary treadmill, then on the treadmill running at
it's lowest speed. Training was immediately stopped if the rabbit became
frightened or agitated. It took approximately one week to train the rabbits
to run on the treadmill. The authors have trained more than 500 rabbits
with this technique. Their failure rate has been <1%. Animals are attended
constantly while on the treadmill. Rabbits are not exercised for 5 days
post surgical intervention or experimental traumatic injury. The customized
run design should be long and narrow to prevent the rabbit from turning
around. Exercise should be moderate - the authors point out the rabbit's
small heart and lung capacity ("rabbits are not aerobic athletes").
Questions:
1. Give the genus and specie of the Flemish Giant rabbit.
Answer:
The Flemish Giant is a domestic breed of the wild European rabbit,
Oryctolagus cuniculus.
Use of a Cardiac Access Port for Repeated Collection of Blood Samples
from Desert Tortioses (Gopherus agassizii). Contemporary Topics
37 (6): 81.
Use of a Cardiac Access Port for Repeated Collection of Blood Samples
from veins, brachial arteries and veins, scapular veins, occipital sinus,
tail vein, orbital sinus and toenails. Investigators have also done repeated
cardiocentesis by drilling holes in the plastron for access to the heart.
Tortoises were anaesthetized and prepared for sterile surgery. A sterile
stainless-steel bit drill bit and cordless drill were used to create a
hole perpendicularly through the plastron at a point on the midline at
the junction of the humeral and pectoral scutes or just caudal to that
point, toward the junction of the pectoral and abdominal scutes. A curved
No. 12 scalpel blade was used to excise the underlying periosteal and coelomic
membranes at the bottom of the hole. Once the access hole was created,
a sterile rubber stopper from a 3-ml evacuated glass tube was inserted.
Epoxy was used to seel the rubber stopper in place. Blood samples were
then collected with the animals in ventral recumbency with a 27 gauge 5/8
in needle. 13/14 tortoises tolerated the procedure well and were bleed
9-23 times over a period of 3-6 months. One tortoise died 2 days after
the repeated blood collection period possibly due to respiratory infection
with Mycoplasma agassizii. Two additional tortoises were euthanized after
port removal and repair due to respiratory disease. None of the other tortoises
suffered adverse effects during blood collection or for 8 months after
completion of the study. For 5 tortoises, removal of the port and repair
of the plastron as long as 8 months after insertion of the port did not
appear to cause adverse effects.
Questions
1. Common name for Gopherus agassizii is
a. Ground squirrel
b. Desert Tortoise
c. Brown backed Gopher
d. none of the above
2. T/F Use of a cardiac access port for repeated collection of blood
samples
from Desert Tortoises requires pericardial excision to prevent cardiac
tamponade.
3. The carapace is the covering on the ______ side of a turtle or tortoise
and the plastron is the covering on the _____ side of a turtle or tortoise.
Answers;
1. b, Desert Tortoise
2. F, pericardial excision was shown not to be necessary
3. dorsal, ventral
A New Feeder for Diet Optimization in Rats. Contemporary Topics 37
(6): 84.
A new commercially-available feeder for rats is described. This feeder
(from Lab Products) contains seven separate feed-containing wells, arranged
in a circular "carousel" array, covered by a stainless steel plate which
contains a single hole, which exposes only one well to the rat at a time.
The wells are intended to be rotated one position per day, so that an entire
week's food is contained in the feeder when filled. A modified cage door
is necessary to hold these feeders. The feeder is intended to feed singly-housed
rats a uniformly-measured amount of feed each day; this amount of feed
is reduced somewhat below the amount a rat of a similar genetic disposition,
sex, and age/weight would consume in a full ad libitum free-choice feeding
scheme where an excess of feed was always available.
Animals given a strategically reduced quantity of feed tend to live
longer and exhibit increased resistance to developing neoplasia at all
ages. Feeding this amount of diet is termed "diet optimization" or DO,
and results in a 15 to 20% savings in the total number of animals needed
to achieve statistically-significant results in aging, toxicologic or carcinogenicity
studies. An additional savings is achieved in reading tissue slides from
animals fed using DO, in that reduced body fat, and a reduction in lesions
associated with aging of these animals, makes detection of lesions due
to neoplasia or toxicologic processes easier, and less time-consuming.
An automated device for filling the feed cups with ground rodent diet
is described; typically, 20 feeders can be filled per minute using the
filler with feeders on a conveyor belt. Use of such a device for filling
feeders can reduce the potential for employees to develop repetitive motion
injuries from filling feeders manually. The feeders are stackable, for
ease in handling and storage.
QUESTIONS:
1. What term is used to describe feeding a reduced amount of feed so
as to maximize lifespan in rodents.
2. Name three characteristics and three benefits of feeding less diet
to rodents in long-term studies.
3. Describe a feeder designed to supply one week of rodent feed using
a diet optimization technique.
ANSWERS:
1. Diet Optimization or "DO".
2. Animals are less obese, live longer, and have fewer naturally-arising
tumors at any age. There is reduced feed purchase cost per animal, reduced
early animal death enables completing long-term studies with fewer total
animals required for statistically-significant results, overall caging
costs are reduced, and reading pathological slides for postmortem examination
of tissues for evidence of substance-related toxicological lesions or carcinogenesis
is facilitated due to less body fat and fewer age-related abnormalities
in tissues.
3. The feeder consists of seven wells in a circular pattern, covered
by a stainless steel circular plate possessing a single hole, intended
to expose only one well of food at a time. The feeder is rotated one well
per day, in carousel fashion, and fits into a modified cage door. Needless
to say, this optimization technique applies to singly-housed animals. The
feeders are stackable, and ground feed can be automatically dispensed into
these feeders on a conveyor belt, using a specialized filling device.
Apparent Psychogenic Polydipsia and Secondary Polyuria in Laboratory-Housed
New Zealand White Rabbits. Contemporary Topics 37 (6): 87.
(Note: This is the 1st report of APP in rabbits.)
Behavior is a homeostatic control mechanism that is subservient to
various biological functions. The artificial laboratory environment may
disrupt normal behavior and cause behavioral abnormalities. One abnormal
behavior is the excessive intake of water for no apparent physiological
reason.
Polyuria and polydipsia is usually caused by renal failure/disease,
hyperadrenocorticism, hypoadrenocorticism, liver disease, diabetes mellitus,
diabetes insipidus, hypothyroidism, hyperthyroidism, or pyometra. Once
these causes are ruled out, psychogenic causes must be considered.
In psychogenic PD, the urine become very dilute and urine output increases.
Because psychiatric analyses of animals is not possible, the term apparent
psychogenic polydipsia (APP) is preferred in animals. APP has been reported
in rats, dogs, cats, human, and NHPs. A 7-month old, 3.3kg female SPF NZW
rabbit was housed under normal laboratory conditions and was being used
for polyclonal antibody production. Increased urine output and water consumption
was noted. Urinalysis, CBC, and serum chemistries were normal, except for
a decreased urine specific gravity (1.005). An 8-hour water deprivation
test indicated normal urine concentrating ability (urine SpGr increased
to 1.023). A diagnosis of APP was made; the rabbit was euthanized. Gross
and histopathologic examination of the tissues were normal. Over the course
of a year, 3 more rabbits were identified to have APP. A variety of enrichment
devices were provided (toys, hay, bowls) which resulted in dramatic decrease
in the polydipsia and reduced urine output to the normal range. The underlying
cause of the behavioral disturbance was not determined, although it is
postulated that some animals may be particularly sensitive to environmental
stress. These animals may benefit from the provision of environmental enrichment.
Questions:
1) Name 3 common causes of polyuria/polydipsia in animals.
2) Name 3 animal species in which APP has been reported to occur.
3) T/F APP in rabbits was responsive to environmental enrichment.
Answers:
1) renal failure/disease, hyperadrenocorticism, hypoadrenocorticism,
liver disease, diabetes mellitus, diabetes insipidus, hypothyroidism, hyperthyroidism,
or pyometra.
2) rats, dogs, cats, human, and NHPs, and now rabbits
3) T
Aplasia of a Uterine Horm in Two Syrian Hamsters (Mesocricetus
auratus). Contemporary Topics 37 (6): 90.
Two of 1500 hamsters which were used for oviduct collection had aplasia
of the uterine horns. The hamsters were superovulated using hCG and PMSG
24 hours prior to collection. They were euthanized for tissue collection.
The two hamsters with aplasia had their reproductive tracts examined histologically.
The abnormal uterine horn consisted of smooth muscle bundles interspersed
with bands of fibrous connective tissue, covered by normal mucosa and submucosa.
No lumen was present. In both cases, it was the left horn which was involved.
Aplasia of left uterine horn has been previously documented in piebald
hamsters and this colony was established from two piebald male littermates.
25% of the piebald females had aplasia to some degree. The incidence is
under 1% for hamsters with the wild-type color.
Questions:
1) What mutation of hamster has a 25% incidence of left uterine horn
aplasia in the females?
2) What are possible implications of aplasia of the uterine horn?
Answers:
1) The piebald
2) Decreased fertility due to decreased possible implantation sites.
Possible heritable aspect. Because occurs to infrequently in normal Syrian
hamster population, significance to research and production is probably
minimal.
Anomalous Anatomy of the Coronary Artery in a Dog. Contemporary Topics
37 (6): 92.
The authors decribed a study in which myocardial efficiency was to
be examined in a healthy purpose bred hound using Doppler flow probes after
a cardiopulmonary bypass (CPB). The flow probes were to be placed around
the main branches of the left and right coronary arteries, baseline measurements
obtained and the dog was to be placed on CPB.
The dog was anesthetized with thiopental sodium, intubated, and mechanically
ventilated. After a left lateral thoractomy, the left cranial descending
and the left circumflex coronary arteries were dissected and the Doppler
flow probes were placed around the main branches of the left and right
coronary arteries. The dog was repositioned in dorsal recumbancy so a median
sternotomy could be done to facilitate dissection of the proximal end of
the right coronary artery. After repositioning, the dog developed ventricular
arrhythmia that was unresponsive to lidocaine. Ventricular fibrillation
was detected after the thoracotomy and could not be corrected, even with
repeated attempts of internal defribrillation. The dog was euthanized and
necropsied.
Gross inspection of the heart valves, septa and great arteries showed
no abnormalities. Dissection of the coronary arteries revealed that the
dog did not have a left common coronary artery. There instead, were 3 left
coronary arteries originating separately from the aortic root; the left
cranial descending artery (LCD), the left circumflex artery (LCX) and the
left septal artery (LSA). The orifices of these 3 arteries originated from
a common fossa inside the aorta. The right coronary artery had an accessory
right coronary artery. These vessels did not have a common fossa.
The authors postulated that the LSA was compromised by compression
when the flow probe was placed in the LCD. Repositioning the dog further
compressed the LSA and induced septal ischemia, which resulted in ventricular
fibrillation. Hypoxemia, electrolyte disturbances and anesthesia overdose
were all ruled out.
This was the first reported case of 5 coronary arteries in the dog.
"Description of the coronary anatomy of the dog is not uniform among investigators....however......
5 separate coronary arteries has not been reported".
Questions
1. List methods to determine coronary artery or myocardial blood flow.
2. What are the advantages of using Doppler flow probes to determine
coronary artery or myocardial blood flow?
3. What is the disadvantage of using the Doppler flow probe?
Answers
1. Thermodilution, gas clearance, electromagnetic flow probes, microspheres
and Doppler flow probes.
2. It is considered accurate, reliable and inexpensive
3. If one wants to measure total coronary blood flow, data acquisition
may be compromised due to accessory coronary arteries that can be overlooked.
Careful dissection of the coronary arteries after the study is necessary
to assess variation in the anatomy of the coronary arteries.
Eosinophilic Polymyositis in a Mouse. Contemporary Topics
37 (6): 94.
This is a case report on a mouse in which two siblings had died at
seven weeks of age. The litter of mice (4 males, 1 female) had been transferred
at six weeks of age to a cage with a running wheel. On days 5 and 6 after
transfer, two of the male siblings were found dead. The female mouse was
thin, ataxic, dehydrated, with ruffled hair, and difficulty righting. No
gross lesions were found on necropsy of the female mouse. A multifocal
eosinophilic inflammatory infiltrate was seen on histologic sections of
skeletal muscle and cardiac muscle. Some of the foci also contained lymphocytes
and histiocytes. Mild to moderate fibrosis was seen within the ventricular
myocardium. Skeletal muscle inflammatory foci contained degenerating, fragmented
muscle fibers. The diagnosis was idiopathic eosinophilic polymyositis.
Questions:
1) Look at photographs of histologic findings on page 94 and 95- be
able to name the condition or give a morphologic diagnosis if shown similar
pictures
2) What animal model has been described for this condition in humans
and how does this model vary from the human disease?
3) What supplements/drugs have been associated with eosinophilic polymyositis
in humans?
Answers:
1) be familiar with pictures on pg. 94 and 95
2) Canine model- generally only the muscles of mastication are involved
in the canine model whereas in humans both skeletal and cardiac muscle
are involved.
3) the asthma drug Tranilast, one lot of L-tryptophan supplement