Special feeding and care of senescent spontaneously hypertensive rats. Contemporary Topics 38 (4): 7.
This study shows that as the female spontaneously hypertensive rats (SHR) mature, special care and handling is key to maintaining body weights and good health. They investigated the impact of feeding methods on body weight of senescent (aged) SHRs and showed that supplementing powdered feed was useful as they approached heart failure. SHRs are genetically predisposed to systemic hypertension and will progress into complete heart failure resulting in death. Close to the time of heart failure (22 to 23 months of age), some rats experienced a loss of appetite and weakness, resulting in malnutrition and weight loss. Animals were fed commercially available rat chow pellets until they showed persistent signs of weight loss or a lack of interest in their food. At that time, the rats were also given powdered rat chow in shallow bowls to facilitate the eating and the digestion of their food. After starting the powdered chow, the rats either maintained or gained weight and prevented malnutrition. Therefore, by supplementing powdered food, it is possible to maintain the health of senescent SHRs until the termination of a study or onset of heart failure.
QUESTIONS:
1) What condition can contribute to weight loss and mortality in senescentSHR rats?
2) What feeding practice can increase viability of debilitated senescent rats?
ANSWERS:
1) Malnutrition due to inappetence or weakness.
2) Supplementing powdered rodent chow to the diet.

The use of a percutaneous endoscopic gastrotomy (PEG) tube to reverse fatal fasting syndrome in a cynomolgus macaque (Macaca fascicularis). Contemporary Topics 38 (4): 12.
An aged, overweight, female cyno had an history of chronic anorexia, weight loss, elevated serum ALP and bilirubinemia. A percutaneous endoscopic gastrostomy (PEG) tube was inserted after one month of oral gavage. Animal began to eat voluntarily within 2 weeks. PEG tube was removed. The animal's weight gradually increased and stabilized at 88% of original body weigt. One year after initial examination, liver biopsy showed the pathology was unchanged. Almost 2 years after initial examination, the animal was found to be SRV positive and was euthanised.
At necropsy, liver was enlarged, pale and friable. Mild hepatic lipidosis was confirmed using Oil Red O stain.
Technique for PEG tube placement:
1. Place anesthetized animal on right lateral recumbency.
2. Pass the gastroscope into the stomach. Distend with air.
3. Insert a 18 ga needle percutaneously into the stomach (where the endoscope light is).
4. 1-0 Silk is fed through the trochar into the stomach, grabbed by the endoscope and pulled out through the mouth.
5. The PEG tube is tied to the suture and pulled in using the "stomach" end of the suture.
6. A small cutaneous incision is made to allow the free end of the PEG tube through, wedging the internal flange and mushroom tip against the gastic wall. An external flange secured the apposition of the gastric and abdominal walls.
7. The PEG tube was capped and protected by a primate jacket.
8. To remove the tube: exert a firm traction on the tube while applying counter pressure on the abodomen.
Question:
1. How long did it take for clinical signs to resume, after placement of the PEG tube ?
2. How long di it take to recover normal liver fonction ?
Answer:
1. Approx. 2 weeks to eat voluntarily.
2. Still after 2 years, liver pathology was present.

A modified cage to minimize catheter contamination in the chronically catheterized baboon. Contemporary Topics 38 (4): 16.
The title says it all. Jacket and tether systems have been in use for over 20 years to allow freedom of movement for nonhuman primates with chronic instrumentation. The tether either feeds the catheters to a hole in the side of the cage (these systems are prone to twisting with animal movement) or to a fixed swivel which allows animals to spin without twisting the lines. In either case, removing the animals more than 1-2 feet from the cage requires disconnecting the catheters.
In this situation, the baboons were going to be severely immunosuppressed for bone marrow transplantation, so catheter contamination during disconnection/reconnection could lead to sepsis. Also, the baboons were to be frequently moved to a remote location for irradiation. This article describes modifications to a baboon cage that allowed frequent removal from the cage without disconnecting the catheter. The pictures are excellent supplements to the descriptions. In all, 10 baboons were removed an average of 30 times each and none of them showed signs of sepsis during the course of the study. Removal was completed by two people in an average of 2-3 minutes by two people, but could be accomplished by a single individual when necessary.
Questions
1) What are three methods of protecting chronic instrumentation in nonhuman primates?
2) What are two means of exiting instrumentation from a nonhuman primate cage and the advantages/disadvantages of each?
Answers
1) chairs, jacket and tether systems, jacket and telemetry systems
2) hole in cage wall - simple to use and maintain, increased flexibility in the number of catheters that can be used, subject to twisting
swivel - more expensive, fixed number of connectors, allow more activity without twisting catheters

Progressive anemia in a Pig-tail Macaque with AIDS. Contemporary Topics 38 (4): 20.
The article is a diagnostic report of progressive anemia in a pig-tailed macaque.
A female 3.5-year of pig tail macque (Maccaca nemestrina) was used a s part of a cohort of animals to study the pathogenesis of inmunodeficiency caused by and HIV like virus. The animal had normal complete blood counts, serum chemistries, and was free of any retroviruses. They only parasites found were Balantidium coli, which was treated and resolved.
The animal was then inoculated with KUSHIV-1B. This microorganism is a pathogenic chimeric immunodeficiency virus composed of the env, tat, rev, and vpu of HIV-HXB2 on a background of SIVmac239. It causes severe immunodeficiency by elimination of CD4 lymphocytes. The animal^Òs progress of infection was monitored by examination of the attack rate of the virus in CD4+T cells in blood. The animal became immunocompromised beginning at week 12. At week 14 of the infection the body weight began to decline. At week 6-post inoculation the animal began to develop anemia. The hematocrit fell from 37% to 27% and progressively fell over the next 16 weeks to a naidir of 14.1%. The animal was euthanized at week 22 post ­inoculation.
Anemias are generally described ad consumptive disorders or production defects. Consumptive disorders include autoimmune hemolytic anemia, parasitic infection and acute and chronic hemorrhage. Frequent blood sampling required for doing retroviral studies can cause anemia when monthly blood volumes exceed 20%. Production defects of ineffective hematopoiesis can be due to iron or B12 deficiency, bone marrow intoxicants, myelophthisis or various viral infections. The presence of giant pronormblast and inclusion bodies in erythroid precursors on both cytology and histology preparations gave the presumptive diagnosis of infection with a simian parvovirus. Simian parvovirus viremia in the macaque was confirmed by dot-blot hybridization. Human B19 and the simian parvovirus are single ­stranded non-enveloped DNA viruses with tropism for erythroid precursors. Transmission of the virus may be by aerosol of fomites, although neither rout is proven. B19 parvovirus infection in humans in a healthy person is termed "erythyema infectiosum or fifth disease. The virus my cause inutero development of hydrops fetalis of congenital anemia. Due to their small DNA content and lack of a lipid envelope, parvoviruses are heat-stable and resistant to solvent detergents. This allows them to persist in the environment and become an opportunistic infection of animals. In summary simian parvovirus should be considered in the differential diagnosis of anemia in the macaques typically used in research.
[Author's note: One comment on the review below. The outcome of the parvovirus infection is dependent on the immune status of the host (human or non-human). The infection in the immune competent individual is transient and resolves in several weeks. An immune deficient individual is unable to mount an immune response and the virus replicates freely causing the progressive anemia.]
No questions

Indirect fluorescent antibody (IFA) assay. Contemporary Topics 38 (4): 23.
This is a technology update about the Indirect Fluorescent Antibody assay. The purpose of IFA assays is to detect antibodies to specific pathogens indicating exposure of a host to an organism.
Briefly, the method for the assay is to adhere viral infected tissue culture cells (or tissue sections) to a microscope slide. Diluted serum sample (containing primary antibody) can then be incubated on the slide and anti-viral antibodies, if present, will bind to viral proteins on the adhered sample.
The slide is then washed to remove non-specific and unbound antibodies. Infected cells are then incubated with a fluorescent-labeled secondary antibody that binds specifically to the anti-viral antibodies of the infected animal. Again unbound secondary antibodies are washed off, and the specific fluorescence of the secondary antibody is viewed with a fluorescent microscope. Those cells incubated with serum from infected animals will fluoresce. Controls for this assay might include using uninfected cells adhered to a slide and tested similarly with antibody.
Other techniques that can be used to detect specific antibodies include Enzyme-Linked Immunosorbent Assays (ELISAs), Hemmagglutination Inhibition Assays (HIAs), immunohistochemistry and Western blots.
The IFA tends to have a high sensitivity and a moderate to high specificity. In addition, IFAs tend to be relatively inexpensive to perform.
However, interpretation may be subjective and depend upon the experience of the researcher; also non-specific background fluorescence may confound interpretation.
No questions