Serum Cobalamin (Vitamin B12) Concentrations in Rhesus Macaques (Macaca mulatta) and Pigtailed Macaques (Macaca nemestrina) with Chronic Idiopathic Diarrhea.

Chronic diarrhea poses a significant threat to the health of NHP research colonies, and its primary etiology remains unclear. In macaques, the clinical presentation of intractable diarrhea and weight loss that are accompanied by inflammatory infiltrates within the gastrointestinal tract closely resembles inflammatory bowel disease of humans, dogs, and cats, in which low serum and tissue cobalamin (vitamin B12) levels are due to intestinal malabsorption. We therefore hypothesized that macaques with chronic idiopathic diarrhea (CID) have lower serum cobalamin concentrations than do healthy macaques. Here we measured serum cobalamin concentrations in both rhesus and pigtailed macaques with CID and compared them with those of healthy controls. Serum cobalamin levels were 2.5-fold lower in pigtailed macaques with CID than control animals but did not differ between rhesus macaques with CID and their controls. This finding supports the use of serum cobalamin concentration as an adjunct diagnostic tool in pigtailed macaques that present with clinical symptoms of chronic gastrointestinal disease. This use of serum vitamin B12 levels has implications for the future use of parenteral cobalamin supplementation to improve clinical outcomes in this species.

Parameters of the center of pressure displacement on the saddle during hippotherapy on different surfaces

Background: Hippotherapy uses horseback riding movements for therapeutic purposes. In addition to the horse's movement, the choice of equipment and types of floor are also useful in the intervention. The quantification of dynamic parameters that define the interaction of the surface of contact between horse and rider provides insight into how the type of floor surface variations act upon the subject's postural control. Objective: To test whether different types of surfaces promote changes in the amplitude (ACOP) and velocity (VCOP) of the center of pressure (COP) displacement during the rider's contact with the saddle on the horse's back. Method: Twenty two healthy adult male subjects with experience in riding were evaluated. The penetration resistances of asphalt, sand and grass surfaces were measured. The COP data were collected on the three surfaces using a pressure measurement mat. Results: ACOP values were higher in sand, followed by grass and asphalt, with significant differences between sand and asphalt (anteroposterior, p=0.042; mediolateral, p=0.019). The ACOP and VCOP values were higher in the anteroposterior than in the mediolateral direction on all surfaces (ACOP, p=0.001; VCOP, p=0.006). The VCOP did not differ between the surfaces. Conclusion: Postural control, measured by the COP displacement, undergoes variations in its amplitude as a result of the type of floor surface. Therefore, these results reinforce the importance of the choice of floor surface when defining the strategy to be used during hippotherapy intervention. .

Transmission of Chagas disease via blood transfusions in 2 immunosuppressed pigtailed macaques (Macaca nemestrina).

A 2.25-y-old male pigtailed macaque (Macaca nemestrina) was experimentally irradiated and received a bone marrow transplant. After transplantation and engraftment, the macaque had unexpected recurring pancytopenia and dependent edema of the prepuce, scrotum, and legs. The diagnostic work-up included a blood smear, which revealed a trypomastigote consistent with Trypanosoma cruzi, the causative agent of Chagas disease (CD). We initially hypothesized that the macaque had acquired the infection when it lived in Georgia. However, because the animal had received multiple blood transfusions, all blood donors were screened for CD. One male pigtailed macaque blood donor, which was previously housed in Louisiana, was positive for T. cruzi antibodies via serology. Due to the low prevalence of infection in Georgia, the blood transfusion was hypothesized to be the source of T. cruzi infection. The transfusion was confirmed as the mechanism of transmission when screening of archived serum revealed seroconversion after blood transfusion from the seropositive blood donor. The macaque made a full clinical recovery, and further follow-up including thoracic radiography, echocardiography, and gross necropsy did not show any abnormalities associated with CD. Other animals that received blood transfusions from the positive blood donor were tested, and one additional pigtailed macaque on the same research protocol was positive for T. cruzi. Although CD has been reported to occur in many nonhuman primate species, especially pigtailed macaques, the transmission of CD via blood transfusion in nonhuman primates has not been reported previously.

[Measurement and analysis of hematology and blood chemistry parameters in northern pig-tailed macaques (Macaca leonina)].

The pig-tailed macaque is an important non-human primate experimental animal model that has been widely used in the research of AIDS and other diseases. Pig-tailed macaques include Mentawai macaques (Macaca pagensis), Sunda pig-tailed macaques (M. nemestrina) and northern pig-tailed macaques (M. leonina). Northern pig-tailed macaques inhabit China and surrounding Southeast Asia countries. To our knowledge, no reports have been published regarding the hematology and blood chemistry parameters of northern pig-tailed macaques, which are important for the objective evaluation of experimental results. We measured and analyzed 18 hematology parameters and 13 blood chemistry parameters in juvenile (aged 2-4 years) and adult (aged 5-10 years) northern pig-tailed macaques. We found that red blood cells, hemoglobin and alkaline phosphatase values were lower in female macaques than male macaques in both juvenile and adult groups. White blood cells, lymphocyte, monocytes, platelet distribution width, cholesterol, aspartate aminotransferase and alkaline phosphatase values were higher in juvenile macaques than adult macaques, while creatinine and triglycerides values were lower in juvenile macaques. Mean corpuscular hemoglobin and creatinine values were positively correlated with weight in juvenile groups. In adult groups, mean corpuscular hemoglobin, percentage of granulocyte, hemoglobin and creatinine were also positively correlated with weight, and lymphocyte, percentage of lymphocyte, red cell distribution width, aspartate aminotransferase and cholesterol values were negatively correlated with weight. The results suggest that age, gender and weight of northern pig-tailed macaques affected their hematology and blood chemistry parameters. This hematological and blood chemistry study has great significance in biomedical research and animal models using northern pig-tailed macaque as an experimental animal.

Hormonal synchronization of the menstrual cycles of pigtail macaques to facilitate biomedical research including modeling HIV susceptibility.

BACKGROUND: Menstrual cycle synchronization of female pigtail macaques could prove an invaluable resource in studies of the reproductive tract, associated infections, and other potential research fields. We tested whether use of an oral progesterone and estradiol combination tablet could synchronize menstrual cycles following treatment discontinuation. METHODS: Daily desogestrel 0.075 mg and ethinyl estradiol 0.01 mg were administered orally to three pigtail macaques at visual onset of perineal sex swelling and were continued until all animals had received it for at least 45 days. The hormones were discontinued, and these three macaques and three controls were observed for menstruation and had blood progesterone and estrogen measured over an additional 2-month period. RESULTS: All treatment animals showed spontaneous menstrual cycle synchronization for 2 months after menstrual cycling resumed. CONCLUSION: Progesterone and estradiol combination therapy can be used in pigtail macaques to induce synchronized cycling that persists in the absence of on-going hormone treatments.

Pregnancy does not increase CYP3A or P-glycoprotein activity in the non-human primate, Macaca nemestrina.

Plasma concentrations of protease inhibitors are lower in pregnant women than in nonpregnant women or men. Using nelfinavir as a model protease inhibitor, we have shown that this phenomenon can be reproduced in a representative non-human primate model, Macaca nemestrina (J Pharmacol Exp Ther 329:1016-1022, 2009). Nelfinavir is cleared from the body predominantly by CYP3A metabolism and P-glycoprotein (P-gp) efflux. Therefore, using midazolam (MDZ) as a CYP3A probe and digoxin (DIG) as a P-gp probe, we determined the antepartum (73-118 days) and postpartum (61-130 days) in vivo intestinal and hepatic CYP3A or P-gp activity in the macaque. Although the systemic clearance of MDZ was significantly increased ( approximately 70%) during pregnancy after intra-arterial (IA) administration of the drug ((15)N-labeled MDZ; 40 microg/kg), pregnancy did not affect the oral clearance of the drug administered simultaneously (1 mg/kg p.o.) with the IA dose. In vitro studies in hepatic and intestinal S-9 fractions indicated no effect of pregnancy on CYP3A activity or protein expression in the small intestine or liver. In contrast, neither the oral (100 microg/kg) nor the IA (10 microg/kg) clearance of DIG was significantly altered by pregnancy, indicating no effect of pregnancy on P-gp activity. Assuming that MDZ and DIG are selective substrates of the macaque CYP3A enzymes and P-gp, respectively, these results suggest that factors other than increased CYP3A or P-gp activity contribute to the increased clearance of protease inhibitors during M. nemestrina pregnancy.

Phenotypic and cytolytic activity of Macaca nemestrina natural killer cells isolated from blood and expanded in vitro.

Natural killer (NK) cells from nonhuman primates have not been completely characterized, and methods for expanding nonhuman primates NK cells in vitro have been described only in rhesus species. The purpose of this report was to characterize NK cells in pigtail macaques (Macaca nemestrina), a species that is frequently used in studies of transplantation biology/immunology, virology, vaccine development, and reproductive biology. NK cells from Macaca nemestrina peripheral blood were best defined by the expression of CD16 and CD8alpha, and the absence of CD3. Subsets of these cells express CD56, NKp30, and NKp46. An enhanced ability to kill K562 cells was not present in fluorescence activated cell sorted (FACS)-purified CD16-/CD3+ and CD16-/CD56+ cells isolated from fresh peripheral blood. However, FACS-purified CD16+/CD3- and CD16+/CD56- cells were highly efficient killers of K562 cells. Macaca nemestrina NK cells can be expanded by in vitro culturing of FACS-purified CD16+/CD2-/CD3-/CD56- cells, or from peripheral blood cells depleted of cells expressing CD3, CD4, and HLA-DR. Cells in these cultures expand 70-fold after 21 days of culturing. After culturing, these cells express high levels of natural cytotoxicity receptors (NCRs) NKp30 and NKp46. NK cell populations obtained from FACS-purified CD16+/CD3-, CD16+/CD56- cells and CD3/CD4/HLA-DR-depleted cells were highly efficient killers of K562 cells. These data suggest that a population of highly enriched cytolytic NK cells can be obtained from purified CD16+/CD3- and CD16+/CD56- cells obtained from peripheral blood, as well as from cells that have been cultured and expanded from peripheral blood that is depleted of CD3/CD4/HLA-DR-expressing cells.

Dehydroepiandrosterone-sulfate as a biomarker of senescence in male non-human primates.

Numerous studies have suggested important and varying roles for dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulfate (DHEA-S) in primate physiological functions. Despite these numerous claims, specific actions and significance of DHEA and DHEA-S are still equivocal. A decline of these hormones in adult humans may have functional significance, yet there is no clear relationship between functional impairments of aging and the decline in DHEA or DHEA-S levels. This current study attempts to address the natural history of adrenal hormones by presenting non-human primate evidence of the endocrinology of aging; the age-related patterns of adrenal hormone decline in three species of the subfamily Cercopithecinae, Macaca mulatta, Macaca nemestrina, and Papio cynocephalus are compared. It is concluded that DHEA-S and cortisol represent lineage specific markers of senescence among primates and that parallel age-related patterns of DHEA-S and cortisol likely reflect lineage specific effects, or rather, phylogenetic similarities of endocrine senescence. The use of relative adrenal hormone levels to approximate species' life expectancies is discussed.

Severe combined immunodeficient mice engrafted with macaque peripheral blood leukocytes support replication of SIVsmm.

Peripheral blood leukocytes (PBLs) from normal pigtail macaques were engrafted into severe combined immunodeficient C.B-17 scid/scid (SCID) mice to develop a small animal model in which to study and identify genetic determinants responsible for the acutely lethal disease syndrome induced by SIVsmmPBj14 (SIV-PBj14) in pigtail macaques. In vivo infection of macaques with SIV-PBj14 results in acute disease in all animals and death of most animals, depending on the route of infection, due to immune activation and production of inflammatory cytokines. A small animal model in which a similar acute disease syndrome was induced would facilitate screening of virus variants to identify regions of the SIV-PBj14 genome responsible for the unique phenotype. Although intraperitoneal inoculation of SCID mice with SIV-PBj14-infected PBLs or uninfected PBLs followed by cell-free SIV-PBj14 produced chimeric mac-PBL-SCID mice that supported SIV replication, obvious clinical signs of disease were not observed. SIV-infected macaque PBLs were recovered from spleen, bone marrow, peripheral blood, and the peritoneal cavity; cell-free SIV was recovered from peritoneal lavage fluid and serum or plasma. PBLs that were mitogen stimulated and SIV-PBj14 infected in vitro migrated rapidly and were recovered from the spleen and bone marrow as early as 1 day after inoculation of mice. The mac-PBL-SCID model may be useful for screening potential drug or immunomodulatory therapies before testing in macaques.

Circulating antioxidants as determinants of the rate of biological aging in pigtailed macaques (Macaca nemestrina).

The effect of antioxidant activity on the rate of biological aging was studied in 39 pigtailed macaques (Macaca nemestrina) 7-30 years of age. Scores of seven antioxidant compounds (vitamins C and E, carotenoids, urate, bilirubin, ceruloplasmin, and albumin) were combined to produce an antioxidant variable (AOx) that was tested for correlation with a second composite variable, rate of biological aging (RBA). RBA was formed from seven physiological variables that met a stringent set of criteria as biomarkers of aging. Potential effects of disease on RBA and AOx were excluded by experimental design and by statistical control using a composite index of disease (Dis) that was based on four measures of clinical history and pathology. The study produced three salient findings: (1) there was a significant inverse relation between AOx and RBA (i.e., animals that had high AOx scores had low RBA scores and vice versa); (2) the relation was independent of Dis effects, and (3) there was no significant relation between AOx and Dis independent of RBA (i.e., the correlation between AOx and Dis was dependent on the correlation of AOx with RBA). These results further validated the RBA variable as a measure of the rate of biological aging and supported the concept that antioxidant activity influences both the rate of biological aging and vulnerability to disease.

Anti-human red cell monoclonal antibodies produced by macaque-mouse heterohybridomas.

Eight monoclonal antibodies (Mabs) against human red cells were produced by macaque-mouse heterohybridomas. All Mabs uniformly reacted with all human red blood cells tested, but only some agglutinated the red cells of anthropoid apes occasionally detecting intraspecies polymorphisms. None was reactive with blood of Old and New World monkeys. One of the Mabs recognized the Vc antigen of the chimpanzee V-A-B-D system, the homologue of the human M-N blood group system.

Constructing an instrument to measure the rate of aging in female pigtailed macaques (Macaca nemestrina).

To develop a battery of innocuous tests measuring individual differences in the rate of biological aging, longitudinal data were gathered on 28 biochemical, physiological, and morphological characteristics of 40 adult female pigtailed macaques. The change in each variable over time, i.e., the beta coefficient of linear regression, was calculated for each animal, and a matrix of correlations among the variables was constructed. Eight variables correlated well with the first principal component of the matrix. These variables (rate of fingernail growth, blood lymphocytes, mean corpuscular hemoglobin, immunoglobulin A, and serum sodium, chloride, total protein, and creatinine) represented the best subset of the potential biomarkers analyzed to produce an index covering a range of morphologic and functional systems that change with age. A similar set representing a wider range of systems and measured over a larger fraction of the life span should provide a valid index of an individual's rate of biological aging.

[The information value of clinico-hematologic criteria for the early diagnosis of acute radiation sickness in pig-tailed macaques]. / Informativnost' kliniko-gematologicheskikh kriteriev rannei diagnostiki ostroi luchevoi bolezni u obez'ian makakov-lapunderov.

Ten pig-tailed monkeys (Macaca nemestrina) were subjected to 60Co radiation at a dose of 6.0-6.5 Gy and a dose rate of 1.2 Gy/min. Acute radiation sickness has developed in the monkeys causing their death on the 16-20 day. In spite of this, the initial reaction was weakly expressed and according to its manifestation it was impossible to evaluate severity and possible outcome of the lesion. At an early stage of the disease (6-24 hours) insufficient was uranin fluorescence in blood plasma, but more informative were the changes in adhesive properties of leukocytes the dynamics of lymphocytes (lymphopenia), reticulocytes (reticulocytopenia) and shifts in reticulograms (increased per cent of juvenile forms).

4-[18F]fluoro-L-m-tyrosine: an L-3,4-dihydroxyphenylalanine analog for probing presynaptic dopaminergic function with positron emission tomography.

4-[18F]Fluoro-L-m-tyrosine (FMT), a biochemical probe of striatal dopaminergic function, has been synthesized as an L-3,4-dihydroxyphenylalanine analog for positron emission tomography. Biochemical characterization of this compound in the rat 30 min after intrajugular administration indicated that in the brain, selective decarboxylation occurred in the striatum, with the formation of 4-fluoro-3-hydroxyphenylethylamine and its metabolites. Positron emission tomography analysis of brain tissue in monkeys (Macaca nemestrina) after intravenous injection of FMT revealed a true time-dependent, specific accumulation of radioactivity in striatum, with a striatum/cerebellum (nonspecific) ratio of 4 at 180 min. Peripheral metabolism accounted for less than 40% of the total radioactivity in arterial blood samples after 120 min. The amino acid remained as the major component throughout the period of investigation (n = 3; 5 min, 95%; 10 min, 85%; 30 min, 67%; 60 min, 62%; 120 min, 60%), with a plasma clearance t 1/2 of 112 min. 3-O-Methylated metabolites were not observed. The substrate specificity of FMT, coupled with its limited in vivo peripheral metabolism, makes it a useful, new biochemical probe for in vivo, noninvasive evaluation of central dopaminergic mechanisms.

An inverse relationship between plasma carnitine and triglycerides in selected Macaca arctoides and Macaca nemistrina fed a low-fat chow diet.

Plasma carnitine and triglycerides were measured in five male Macaca arctoides and one female Macaca nemistrina during the course of feeding a low-fat (5.2% w/w), high carbohydrate diet and a high-fat (15.9% w/w), low carbohydrate diet. For each individual monkey, an inverse relationship was observed between plasma carnitine and triglyceride levels when the low-fat diet was fed but not when the high-fat diet was fed. The mechanism of the different responses to diet was not investigated but may be related to the primary source of the plasma triglycerides (i.e. endogenous origin or exogenous origin) or to differing hormonal effects. A close coupling between carnitine and triglyceride metabolism may be part of a sensitive homeostatic control mechanism that responds to endogenously-synthesized triglyceride.

Purification and characterization of the sex steroid binding protein from macaque serum. Comparison with the human protein.

The sex steroid binding protein (SBP) of Macaca mulatta and Macaca nemestrina sera has been purified to homogeneity and chemically characterized. The native protein is a glycoprotein having a molecular weight of approximately 88 000 and is composed of two similar subunits of molecular weight 47 000 as estimated by sodium dodecyl sulfate gel electrophoresis. One molecule of 5 alpha-dihydrotestosterone is bound per dimer with a KD equal to 1.6 nM at 11 degrees C. Isoelectric focusing patterns reveal the presence of at least 12 different forms of dimeric SBP molecules probably resulting from the presence of different amounts or types of carbohydrate side chains. The data indicate a very close similarity in molecular and steroid-binding properties to human SBP and establish the macaque monkey as a valuable animal model to study the physiological role of SBP in humans.

Pregnancy effects on nonhuman primate high density lipoprotein.

The concentration of cholesterol in high density lipoproteins (HDL) has been showed to be dramatically decreased during pregnancy in Macaca nemestrina. HDL were isolated from females of this species at various stages of pregnancy to determine if pregnancy also alters their composition and size. The chemical compositions of the HDL were determined nad found different in pregnant animals; the mass ratio of surface (coat) to center (core) constituents was higher, suggesting that the average size of HDL decreased during pregnancy. When measured chromatographically, the average size of HDL was found to decrease during pregnancy. This change in HDL size was accompanied by a minor alteration in apolipoprotein distribution.