Contemporary Topics 40(5)

Multivariate regression analysis and other findings from the 1999 joint ASLAP/ACLAM economic survey of laboratory animal veterinarians. Contemporary Topics 40(5), 09.
Abstract: It has been recently shown that multiple regression methods can be applied to salary survey data to develop a highly predictive statistical
model of income. Data from the 1999 economic survey of laboratory animal veterinarians were used to develop a multivariable linear
regression model capable of predicting income. When considered simultaneously, the variables of experience, supervisory responsibility,
ACLAM board certification, geographic region, type of employer, size of animal facility, and job title provided the best model fit. Survey
findings indicate that during 1999 academic institutions employed approximately half of all laboratory animal veterinarians. Gender was not
an important predictor of professional income once other variables were considered. Secondary sources of professional income for
laboratory animal vets continue to represent a measurable supplement to base pay.
Questions: 1.What percentage of laboratory animal vets was employed by academic institutions during 1999?
2.According to the survey results, how many of the respondents have secondary sources of professional income?
3.Is gender an important predictor of professional income for laboratory animal veterinarians?
Answers: 1.Approximately 50%
2.42%
3.Gender is not an important predictor of income once other variables related to experience (years since DVM degree, years of practical lab animal experience, and years since ACLAM board certification) were considered.

A novel interactive electronic protocol review system. Contemporary Topics 40(5), 14.
Abstract: This report describes a new IACUC protocol review system that was designed as a Lotus Notes platform database. Unique features of the system are interactive dialog between IACUC members and the investigator and confidential protocol discussion among IACUC members. The advantages of the system are multiple: It allows for interactive protocol discussion online. It is an essentially paperless process (recycling). The inclusion of the outside IACUC member is easily accomplished by using an offsite personal computer and secure remote local-area network access. The time required for protocol generation, review, and approval is streamlined due to the automatic features of the database and the speed of e-mail. All documentation relating to the protocol and the approval process is archived online and viewing discussions. As you all know, the IACUC review process is arduous and labor intensive. The system described here appears to be an efficient streamlined electronic database with many advantages that includes all aspects of the review process. The three main stages of this programs online process are: Protocol Generation: The investigator completes the Animal Usage Application (AUA). There are help screens and a link to the AWA regulations. The attending veterinarian (AV) performs the pre-review. After the initial review the protocol is circulated to the full IACUC for a 5-day review period. IACUC Review: All members are notified of the protocol submission. (Outside members can access via a LAN remotely). They then access these AUA, protocol and other attachments. Each member has 5 business days to initiate confidential discussion with the investigator and/or other members and approve/disapprove the protocol. Once a clarification is requested the 5-day clock stops until the investigator responds. IACUC Protocol Approval: Protocols are approved under one of two conditions. Either approval, or approval with corrections (within 5 days after a clarification). After approval, the database notifies the investigator, animal purchasing, and the attending vet. Protocols not approved can be revised or a member can request a full-committee review at the next IACUC meeting.
Questions: 1) The advantage of an electronic IACUC review system is:
a. It is more efficient
b. The IACUC members can review them
c. The application can be archived and retrieved
d. All of the above
2) Confidential or anonymous questions can be asked of the investigator.
3) How can the outside IACUC member review online protocols?
a. Through America Online
b. Using a PC and a secure LAN
c. Asking questions by telephone
Answers: 1)d;
2)T;
3)b

Effects of caging type and animal source on the development of foot lesions in Sprague Dawley rats (Rattus norvegicus). Contemporary Topics 40(5), 17.
Abstract: This study summarized findings related to foot pad injury in rats on a carcinogenesis study as related to type of cage floor, age and sex of rats, and supplier of the rats. This was done to provide additional data pertaining to the Guide recommendation for the use of solid floors. This study differed from previous studies in that it included a large number of rats over a two year period and looked at gross lesions, not microscopic ones. There were 600 rats in groups of 50 from two suppliers. Rats were housed either in polycarbonate cages with hardwood chip bedding (Certified Sani-Chips) or wire bottom cages with a sq. inch grid. Rats were individually housed. Cleaning schedules were appropriate for the caging type and feed was standardized. Animals were checked twice daily throughout the study; weight recorded at four week intervals, and any foot lesions described as ulcer or crust, swelling, and callus. Results: Low number of foot lesions for animals housed in polycarbonate cages, lower number from one vendor than the other (heavier rats from one vendor in general correlated with more lesions) on wire bottom cages. Mean time to onset was >400 days. Ulcers and crusts were more common in one vendor (lighter rats) and calluses more for the other (heavier rats). Sex was not predictive except as related to weight. Based on these findings a suggestion is made to allow housing on wire for up to one year, but if longer times are desired to ask for justification. Justifications for wire bottoms include: reduction of coprophagia, animals with ventral abdominal incisions, diabetic animals with high urine production, burn studies, rectal prolapse, and need to prevent animals from eating bedding. Advantages of wire bottom cages include cost, ease of sanitization, lack of flooding, and reduction (not prevention) of coprophagia. Disadvantages include: gnawing on cage bars which may lead to tooth injury, and development of foot lesions. Chew toys and resting boards might reduce these problems. Foot lesion incidence can be increased by prolonged restraint (wetness in restraint device), long-term housing on wire floors, and heavy animals (obesity). Feed restriction to control weight would also be expected to reduce incidence of foot lesions.
Questions: 1. Which housing type is suggested for rodents as being preferred in The Guide for the Care and Use of Laboratory Animals?
A. Any type with acceptable floor space
B. Solid bottom with bedding
C. Wire bottom
D. No type specified
2. What factors were most important in predicting incidence of foot lesions in rats?
A. Vendor and sex
B. Sex and weight
C. Weight and floor type
D. Weight, floor type, and time
3. Which is NOT an advantage of wire bottom cages?
A. Less cost for bedding
B. Prevents coprophagy
C. Easy to sanitize cages
D. Prevents consumption of bedding
Answers: 1. B,
2. D,
3. B (reduces but does not prevent)

Serum corticosterone and blood glucose in rats after two jugular vein blood sampling methods: comparison of the stress response. Contemporary Topics 40(5), 22.
Abstract: Anesthetized noncannulated and nonanesthetized jugular-cannulated Sprague-Dawley rats had blood samples taken over a 2-hour period. Blood glucose and serum corticosterone levels were measured as an indication of stress from the procedure. Peak concentration and time to peak concentration were similar for both study groups. However, more variance was detected in the samples from the anesthetized, noncannulated rats than from the nonanesthetized jugular-cannulated animals. Therefore, stress was slightly greater in the rats that underwent repeated anesthesia.
Questions: 1. Which of the following species are considered corticosteroid-susceptible? Guinea pig, Hamster, Mouse, Ferret, Nonhuman primate, Rat, Rabbit
Answers: The corticosteroid-susceptible species are Hamster, Mouse, Rabbit, and Rat. All other species listed above are considered corticosteroid-resistant. Resistance and susceptibility are determined by the impact on the weight of the thymus.

Evaluation of reproductive indicies in rats (Rattus norvedicus) housed under an intracage ventilation system. Contemporary Topics 40(5), 25.
Abstract: This article describes the effect of intracage ventilation system on reproductive performance as an indirect measure of physiological well-being of rats. It is very important to have an appropriate ventilation system in order to remove the water vapor and pollutants produced by animal metabolism and excretion inside the cages and to control the temperature/humidity in the animal room. In conventional animal facilities, ventilation and environmental factors are typicallly controlled by using a general diluting ventilation (GDV). However, GDV system presents several limitations such as 1) it does not yield the same effect inside the cages, 2) its efficiency is decreased by the low thermal conductivity of the plastic material used in the manufacture of the animal cages, and 3) the microenvironment presents the challenges of high temperature, humidity and pollutant concentration due to decreased air speed inside the cages. Compared to GDV system, intracage ventilation system benefits the microenvironment of the animals by reducing ammonia concentration and the dryer environment inside the cage. Recently it has been reported that ICV system improve reproductive performance in mice as compared to mice housed in GDV system. In this study, ICV system was developed to determine the effect of ICV system on reproductive performance as an indirect measure of physiological well-being of rats. Rats were exposed to five air-speed levels (0.03-0.12 m/s, 0.13-0.18 m/s, 0.19-0.33 m/s, 0.34-0.51 m/s). Reproductive performance data recorded were interval between two successive parturitions, fertility and survival number, number of offspring born, number of offspring weaned, weight of neonatal and suckling rats and mortality of offspring. Results indicated rats housed under ICV conditions tolerate a continuous air flow into the cage without impairing the reproductive performance in any of the groups. Furthermore, air-speed levels ranging from 0.19-0.51 m/s resulted in greater number of and more uniform litters with decreased mortality rates compared to those of the control group.
Questions: 1. Limitations of GDV system includes:
A. does not yield the same effect inside the cages,
B. its efficiency decreases by the low thermal conductivity of the plastic material used in the manufacture of the animal cages,
C. the microenvironment presents the challenges of high temperature, humidity and pollutant concentration due to decreased air speed inside the cages.
D. All of the above
2. True/False: Compared to GDV system, intracage ventilation system benefits the microenvironment of the animals by reducing ammonia concentration and the dryer environment inside the cage.
3. True/False: Intracage ventilation system with air-speed levels ranging from 0.19-0.51 m/s produce greater number of and more uniform litters with decreased mortality rates in rats.
Answers: 1. D
2. True
3. True

Comparison of practical treatment methods to eradicate pinworm (Dentostomella translucida) infections from Mongolian gerbils (Meroines unguiculatus). Contemporary Topics 40(5), 31.
Abstract: Mongolian gerbils are the primary natural host of the gerbil pinworm Dentostomella translucida. This pinworm has a direct life cycle, and ingestion of contaminated feces and bedding is the typical mode of transmission. The prepatent period is 25-29 days, longer than other rodent pinworms. Golden hamsters (Mesocricetus auratus) and the Great gerbil (Rhombomys opimus) may also harbor this pinworm. Fecal flotations usually detect pinworm ova. However, the gerbil pinworm intermittently sheds ova. The location of adult D. translucida is unique in that adults usually reside in the proximal third of the small intestine and on occasion, within the stomach. Most infections are typically asymptomatic; however, the rationale for eliminating the gerbil pinworm is the same as it is for pinworm infections in other rodents.
This study evaluated the efficacy of five treatment methods to eradicate pinworms from Mongolian gerbils: 1) topical ivermectin misting; 2) ivermectin-medicated drinking water; 3) piperazine citrate-medicated drinking water; 4) fenbendazole-medicated feed, & 5) combination ivermectin-medicated water and fenbendazole-medicated feed. Success of treatment was evaluated via weekly fecal flotations and necropsies of fecal-negative animals at 5 weeks post-treatment. Results indicated that only treatments with fenbendazole alone or fenbendazole in combination with ivermectin successfully eradicated fenbendazole-medicated feed (150 ppm) in gerbil colonies. Ivermectin-medicated water caused most gerbils to be negative on fecal flotation; however, necropsy results revealed that all but one of these gerbils harbored adult pinworms. Fenbendazole-based treatment alone is a practical and effective treatment to eradicate pinworms from gerbils. Ivermectin and piperazine treatments were ineffective. Administration of ivermectin alone may yield results suggestive of false eradication.
Questions: 1. Q: What laboratory animal species can harbor Dentostomella translucida?
a. Mus musculus
b. Rattus norvegicus
c. Meriones unguiculatus
d. Mesocricetus auratus
e. c & d
2. Q: A recent study examined the efficacy of several treatment regimens for eradication of Dentostomella translucida from Meriones
unguiculatus. Which of the following treatments was considered to be most efficacious AND practical?
a. topical ivermectin misting
b. ivermectin-medicated drinking water
c. piperazine citrate-medicated drinking water
d. fenbendazole-medicated feed
e. combination ivermectin-medicated drinking water and fenbendazole-medicated feed
Answers: 1. e
2. d

Diet restriction in rat toxicity studies: automated gravimetric dispensing equipment for allocating daily rations of powdered rodent diet into pouches and 7-day feeders. Contemporary Topics 40(5), 37.
Abstract: Ad lib feeding of rats has resulted in decreased survival at the end of the 2-year carcinogenicity bioassay.
Food restriction results in increased survivial of rats at the conclusion of 2-year studies(previous studies).
The improved survivial of rodents at the end of the 2-year study is necessry for scientific and regulatory reasons. The Center for Food Safety and Nutrition (CFSAN) of the FDA currently requires 50% survival at the end of 2-year carcinogenicity studies. The FDA has recommended dietary restriction in 2-year carcinogenicity studies to meet this requirement. Dietary restriction is commonly used in other tox studies with nonrodent species.
The authors present an accurate, reproducible and efficient automated method of food dispensing that would increase survival of SD rats at the end of 2-year studies by restriction of food that could be used when test compound is administered in the diet.
Important points of this equipment are:
1. The dispenser is a gravimetric(as opposed to volumetric) dispenser. 10-22g quantities of diet are dispensed with a tolerance of +/- 3%.
2. The dispenser can be used for food pouch dispensing using the Urania Pouch Pro. The pouch material is a polyethylene/polypropylene bilaminate pouch(a plastic bag) which has been approved by the FDA. The pouches are useful for storing or transporting diet off-site.
3. The system can also be used to dispense in to carousel feeders also called seven-well feeders. These are useful because diet can be dispensed for a full week at a time. These feeders attach to the rats cage and the technician just has to rotate the feeder each day.
Dietary restriction in this study resulted in at least 70% survival at the end of the 2-year study.
In this study modest dietary restriction (75% of ad lib) resulted in survival of 70-82% at the end of a 2-year study. The diet restricted rats were leaner than ad lib rats. At week 90, the mean body weight of diet-restricted rats was 522g for males and 271 for females. Ad lib rats were 712g for males and 621g for females.
The authors also point out that food consumption patterns may have important toxicokinetic implications. Food consumption behavior differs between male and female rats. Male rats may eat all of their ration (and therefore test compound) in a short period of time and females tend to graze.

Note: There is a picture of the 7 well feeder included in the paper.
Questions: 1. What does the acronym CFSAN mean?
2. Why is the FDA suggesting food restriction on 2-year carcinogenicity studies?
3. What was the survival rate at the end of the 2-year study for food restricted animals?
4. The dispensing system dispenses diet into two delivery systems. What are they?
Answers: 1. The Center for Food Safety and Nutrition. This is a division of FDA and requires at least 50% survival at the end of 2-year carcinogenicity studies.
2. The FDA is recommending food restriction because of the 50% survival rate requirement imposed by CFSAN.
3. 70% (or greater).
4. Plastic pouches or 7-day feeders.

Induction of proteinuric chronic glomerular disease in the rat (Rattus norvegicus) by intracardiac injection of doxorubicin hydrochloride. Contemporary Topics 40(5), 44.
Abstract: Doxorubricin hydrochloride (DX) is a cytotoxic anthracycline antibiotic used to treat malignant cancer in humans. When given IV to rats, DX produces an Adriamycin nephropathy (AN) model that allows study of the pathophysiology of acute glomerular injury, the progression of chronic renal disease and the nephrotic syndrome. DX injections to produce the rat AN model have -in >50% of the published reports- been accomplished via the tail vein, but drawbacks to using the tail vein injection route include local skin necrosis, variable disease production and significant occupational hazard to the investigator. As an alternative to using the tail vein injection route, the authors administered DX to rats via a single substernal intracardiac (IC) injection, with reported findings of (1) minimal morbidity and mortality, (2) decreased occupational hazard and (3) improved efficacy of AN induction.
Twenty-eight young adult (6-8 wk old) male Wistar rats weighing ~238g anesthetized with IP ketamine:xylazine (90:10 mg/kg); under sterile conditions in a Class II biological safety hood, each received 1.7 mg DX (=70 mg/kg DX; Adriamycin, 2 mg/ml solution) in a single IC injection via a substernal approach using a 25 -gauge 'butterfly' mini-infusion set.
After cardiac penetration confirmed (pulsatile blood flow in infusion tubing and needle oscillation), DX was infused over a 20 second period, followed by a 1.5 ml flush of normal saline. All subjects were monitored for IC complications (cardiac tamponade, bleeding, embolization) as well as anthracycline-related cardiac toxicity (important because DX is known to cause acute, subacute and chronic cardiac toxicity in rats). Two subjects had complications: one rat died under anesthesia prior to IC injection, and one rat bled acutely from the injection site ('gentle pressure' achieved hemostasis and the animal recovered normally). Urinary protein, creatinine evaluated 24 hrs pre-sacrifice (day 7, 14 or 21) in all rats; blood for serum creatinine, urea, cholesterol collected from IVC at sacrifice, along with kidneys for histopathology; serum and urinary sodium also measured for day-21 subjects.
Rats receiving DX: decreased food intake and weight loss for 5 days following injection; urinary protein excretion 4-25X greater than controls by 7 days post-injection, with hypoalbuminemia and hypercholesterolemia paralleling increases in proteinuria. No post mortem pericardial effusion or cardiac tamponade, but punctate scar grossly visible on heart base, and kidneys (21 day group) appeared pale, edematous, with granular texture. Renal histology confirmed severe nephrotic syndrome with effacement of glomerular epithelial cell foot processes and diffuse cortical tubulointerstitial injury induced in all animals by day 21; cardiac histology not performed.
Study results suggest that a one-time IC injection of DX is faster, safer, and provides a more consistent method of inducing AN in the rat; dermal necrosis was avoided, minimal complications were noted, administration of DX was less time-consuming and researcher exposure was reduced, and severe nephrotic syndrome was produced in all subjects. Authors credit minimal morbidity and mortality to using larger animals (>200 g b.w.) plus limiting the IC sticks to no more than two attempts per animal.
Questions: 1. List four problems associated with administering DX to rats by the tail vein route:
2. List four potential complications of administering DX to rats by IC injection:
3. Thinking like the authors, the decision to justify the acute mortality risks associated with administering a compound IC in rats should be
most influenced by:
a. the experience/skill of the person performing the procedure
b. the value of the rat
c. the toxicity of the compound
d. the investigator's relationship with the IACUC
4. What two factors probably contributed most to the low mortality observed:
a. using an inbred strain
b. using larger animals
c. using an outbred stock
d. limiting IC sticks to no more than two attempts per animal
Answers: 1. local skin necrosis, variable disease production, occupational hazard, time-consuming
2. cardiac tamponade, bleeding, embolization, anthracycline-related cardiac toxicity
3. c. the toxicity of the compound (the authors specifically state "the administration of a drug without the hazards of anthracyclines do not justify the mortality risks associated with intracardiac injection")
4. b. using larger animals
d. limiting IC sticks to no more than two attempts per animal

Ultrasound measurements have been standardized in the dog and cat, which allow veterinarians to use hematologic testing, blood chemistries, urinalysis, and ultrasound to detect abnormalities in the kidneys. Normal renal measurements have not been established for the guinea pig and that is the purpose of this study. This will allow more effective treatment of renal disease in the guinea pig. This study examined 31 white, short-haired, healthy male and female guinea pigs ranging from 3-11 months of age and 391-975g. Each animal was anesthetized with isoflurane. Blood was taken from the jugular vein to measure creatinine, blood urea nitrogen, and alanine aminotransferase. a urinalysis was also performed. For ultrasound examination, the animals were manually restrained in dorsal recumbency. The ventral abdomen was shaved and the kidneys were visualized and measured using a real-time ultrasonographic system equipped with a 7.5-10.5Mhz mechanical transducer. Length and area measurements of the kidneys were recorded 3 times and averaged. Renal length and section were used to calculated renal volume. Area-length prolate ellipsoid geometric model was used for volume calculations. Linear regression analysis modeled the relationship between the body weight and the renal length or calculated renal volume. Significant correlation was found between: 1. body weight and length of left kidney 2. body weight and calculated volume of left kidney 3. body weight and length of right kidney 4. body weight and calculated volume of right kidney Parameters did not differ significantly between the left and right kidney. The use of ultrasonographic measurements in addition to hematologic testing, blood chemistries, urinalysis, and signs may help visualize changes in the kidneys earlier in renal disease and therefore provide earlier detection and more effective treatment. A preliminary study of the ultrasonographic determination of renal size in the guinea pig (Cavia procellus). Contemporary Topics 40(5), 50.
Abstract: Ultrasound measurements have been standardized in the dog and cat, which allow veterinarians to use hematologic testing, blood chemistries, urinalysis, and ultrasound to detect abnormalities in the kidneys. Normal renal measurements have not been established for the guinea pig and that is the purpose of this study. This will allow more effective treatment of renal disease in the guinea pig. This study examined 31 white, short-haired, healthy male and female guinea pigs ranging from 3-11 months of age and 391-975g. Each animal was anesthetized with isoflurane. Blood was taken from the jugular vein to measure creatinine, blood urea nitrogen, and alanine aminotransferase. a urinalysis was also performed. For ultrasound examination, the animals were manually restrained in dorsal recumbency. The ventral abdomen was shaved and the kidneys were visualized and measured using a real-time ultrasonographic system equipped with a 7.5-10.5Mhz mechanical transducer. Length and area measurements of the kidneys were recorded 3 times and averaged. Renal length and section were used to calculated renal volume. Area-length prolate ellipsoid geometric model was used for volume calculations. Linear regression analysis modeled the relationship between the body weight and the renal length or calculated renal volume. Significant correlation was found between: 1. body weight and length of left kidney 2. body weight and calculated volume of left kidney 3. body weight and length of right kidney 4. body weight and calculated volume of right kidney Parameters did not differ significantly between the left and right kidney. The use of ultrasonographic measurements in addition to hematologic testing, blood chemistries, urinalysis, and signs may help visualize changes in the kidneys earlier in renal disease and therefore provide earlier detection and more effective treatment.
Questions: 1. Name 2 conditions in guinea pigs which could lead to chronic renal disease.
2. What nutrient may deficient if not supplemented in the guinea pig diet?
3. What are the advantages of using ultrasound to detect changes in size in the kidneys (larger or smaller)?
4. What are possible problems with using ultrasound?
Answers: 1. A. chronic interstitial nephritis caused by diabetes mellitus B. chronic renal amyloidosis caused by Staphylococcus pododermitis
2. Vitamin C
3. A. noninvasive B. nonionizing imaging C. good visualization of internal pattern of kidneys
4. A. small size of kidney B. mobility of kidney in the abdomen C. different ultrasonographic images used D. large variation in size of animals F. intestines filled with gas

Cutaneous B cell lymphoma in a mongolian gerbil (Meriones unguiculatus). Contemporary Topics 40(5), 53.
Abstract: Among common laboratory rodents, Cutaneous B cell lymphoma has only been reported in hamsters prior to this report in a Mongolian gerbil. In humans, cutaneous B cell lymphoma is common and has been subtyped into several subtypes (marginal-zone B cell lymphoma, follicle center lymphoma, large B cell lymphoma of the leg, intravascular B cell lymphoma, T cell-rich B cell lymphoma and plasmacytoma). The mass was located in the subcutaneous tissue of the right mandible and histologically had large round, dense nuclei and little cytoplasm, suggestive of a lymphoid tumor. Immunocytochemistry and flow cytometry were used to classify this tumor. The neoplastic cells expressed CD19 and IgM but lacked CD3(a T cell marker) and CD11b in immunocytochemical analysis. Furthermore, the cells were positive for CD19, B220, IgM and CD40 but lacked CD3 and CD5 by flow cytometry. CD40 signaling promotes both differentiation and isotype switching of B cells, consequently loss of CD40 statement prevents maturation of B cells. The mid-dermal location, statement of B cell associated CD's and lack of T cell associated CD's and infiltration pattern with macrophages led to the classification of this tumor as a cutaneous B cell lymphoma. Neoplastic cells from this tumor grafted into scid/scid mice were able to proliferate and retain the same phenotype, suggesting that it may be used as an animal model for cutaneous B cell lymphoma.
Questions: 1. Cutaneous B cell lymphoma is common in humans and has also been reported in the following common laboratory rodent(s) (circle all correct answers):
A. Rat
B. Hamster
C. Mongolian gerbil
D. Mouse
2. Markers for B lymphocytes include (circle all correct answers):
A. CD40
B. IgM
C. CD3
D. CD8
3. Upon initial exposure to an antigen, what is the predominant immunoglobulin produced by a B lymphocyte and how does this differ from the secondary antibody response?
Answers: 1. B and C
2. A and B
3. Upon initial exposure to an antigen, the B lymphocyte produces IgM, whereas the dominant antibody produced early in the secondary and subsequent exposures is IgG (predominantly), IgA or IgE

Pituitary adenoma with galactorrhea in an adult male cynomolgus macaque (Macaca fascicularis). Contemporary Topics 40(5), 57.
Abstract: This case report describes the first documented antemortem diagnosis of a prolactin- secreting pituitary tumor in a cynomolgus
macaque. A wild caught adult male cynomolgus on a behavorial assessment study was found to have galactorrhea while anesthesized.
Other, but likely unrelated, abnormalities included hyperglycemia, glucosuria, and ketonuria. Further workup revealed elevated prolactin
and cortisol levels. The animal was euthanized as it decompensated during an ultrasound procedure and a full necropsy was performed.

Necropsy and histopathology revealed that the pituitary was expanded focally by a poorly circumscribed mass of cuboidal to polygonal
cells which were arranged in irregular sheets and nests and were separated by a fine fibrovascular stroma. Immunocytochemical staining
of sections showed strongly positive cytoplasmic staining by antibodies to prolactin and multifocal, faint cytoplasmic staining for
adrencorticotropic hormone (ACTH). Based on these characteristics, the tumor was classified as a prolactin-secreting pituitary adeoma
that derived from the adenohypophysis. On necropsy, this animal was also found to have bilateral mature cataracts, cardiomegaly with
nodular fibrosis on the valve leaflets, and amyloid deposition in the pancreas (consistent with Type II Diabetes Mellitus).

Cushing's syndrome was also a differential in this case, especially in light of the elevated cortisol level. Time did not allow further
diagnostics (ACTH levels, high and low dose dexamethasone suppression tests) but histopathology of the adrenal glands and the faintly
positive ACTH immunohistological staining of the pituitary do not support a diagnosis of Cushing's syndrome.

Treatment options discussed include both medical and surgical options. A transoral, transphenoidal microsurgical exposure of the
pituitary gland has been described in the rhesus monkey. And, medical treatment described in the human literature consists of
bromocriptine therapy which normalizes prolactin levels and allows for a regression of clinical signs.
Questions: 1.Specific diagnostic tests for pituitary adenoma include.
a.CT scan
b.ACTH levels
c.Dexamethasone suppression test
d.Complete blood count
2.Treatment options for prolactin secreting pituitary adeomas include….
a.surgical removal
b.steroid therapy
c.bromocriptine therapy
d.a and c
e.all of the above
Answers: 1.a
2.d

DNA microarray. Contemporary Topics 40(5), 60.
Abstract: DNA Microarray is a nucleic acid based technique used to identify and quantitate the simultaneous expression of thousands of genes. This allows for direct comparison of gene expression between control and experimental groups, and can also be used to identify gene mutations. Potential uses include genetic monitoring, and diagnosis of disease.
1. The genes to be evaluated are obtained by complimentary (cDNA) library, which originated from messenger RNA, or by synthesizing the oligonucleotides. Robotics are used to spot numerous copies of the cDNA or oligonucleotide onto a glass slide (solid phase support). Each spot can be as small as 100-200 microns wide so thousands of cDNA can be arrayed on a single slide with the location of each cDNA known.
2. cDNA probes are synthesized by reverse transcription of mRNA isolated from both control and experimental samples. The number of probe cDNA's made by reverse transcription is proportional to the number of mRNA copies present. Reverse transcriptase allows the incorporation of a fluorescent or radioactive labeled nucleotide into the cDNA probe. (In this example rhodamine is incorporated into the cDNA probe of the controls and a fluorescent-labeled nucleotide is incorporated into the cDNA probe of the experimental group.) Rhodamine will fluoresce red and the other fluorescent tag will fluoresce green.
3. The RNA template used to synthesize the oligonucleotides is removed from the RNA-DNA hybrid by treatment with RNAase. This leaves the labeled cDNA available for hybridization to the arrayed genes.
4. The fluorescent-labeled probes for control and experimental groups are allowed to hybridize to the arrayed cDNA. Any unhybridized probes are removed by a washing step. A fluorescent laser scanner is used to evaluate the arrays for gene expression between the control and experimental group. The fluorescent intensity is proportional to the number of mRNA present in the sample and allows for quantification of gene expression. Since we labeled the control group with rhodamine it will fluoresce red if expressed, and the experimental group will fluoresce green. If the gene is expressed by both the control group and the experimental group the array will fluoresce yellow. Black indicates the gene is not expressed in either group.
Advantages: identify and quantitate multiple genes simultaneously, compare gene expression between treatment group and control group simultaneously, the technique is adaptable to automation.
Disadvantages: Gene expression does not correlate to protein synthesis, Optimization can be labor intensive, requires a laser (specialized equipment) for data interpretation.
Alternative methods: Quantitative competitive RT-PCR, RNAse Protection assay, and Northern blot hybridization.
Questions: 1. An alternative laboratory method for Northern blot hybridization includes:
a. DNA Microarray
b. Quantitative competitive RT-PCR
c. RNAse protection assay
d. All of the above
2. In the technology update on DNA Microarray, gene expression was demonstrated to correlate to protein expression in the following way:
a. Positively correlated
b. Negatively correlated
c. no correlation
d. Exponentially correlated
Answers: D, C