Comparison of the effects of antimicrobial agents from three different classes on metabolism of isoflavonoids by colonic microflora using Etest strips.

Daidzein (4',7-dihydroxyisoflavone), a phytoestrogen found in soybeans mainly in the form of its glycoside daidzin, is metabolized by colonic bacteria to compounds with altered estrogenic activities, which may affect human health. Antibacterial agents used for the treatment of infections can alter the composition of bacterial populations in the colon and therefore can affect daidzein metabolism. To rapidly detect the effects of different concentrations of antibiotics on daidzein metabolism by colonic bacteria of monkeys and identify the subpopulation involved in daidzein metabolism, Etest strips containing antibacterial agents from three classes (tetracyclines, fluoroquinolones, and ß-lactams) were used to eliminate the colonic bacteria that were susceptible to 0-32 µg/ml of each antibacterial agent and test the surviving bacteria for their ability to metabolize daidzein. The metabolism of daidzein by the colonic microflora was measured before and after the colonic bacterial population was exposed to antibacterial agents. The metabolites were detected by high performance liquid chromatography and mass spectrometry after incubation of the cultures for various times. Exposure of colonic microflora to antibiotics had various effects on daidzein metabolism. Tetracycline completely removed the bacteria metabolizing daidzein, metabolism of daidzein was not changed in cultures of bacteria after ceftriaxone treatment, and ciprofloxacin enriched for the bacteria metabolizing daidzein. In liquid cultures treated with various concentrations of ciprofloxacin, 4 µg/ml of ciprofloxacin favored the growth of bacteria that metabolized daidzein. This is the first time in which the Etest has been used to show that, whereas some antibiotics eliminate phytoestrogen-metabolizing bacteria in colonic microflora, others enrich them by eliminating the non-metabolizing strains in the population.

Passive neutralizing antibody controls SHIV viremia and enhances B cell responses in infant macaques.

Maternal HIV-1-specific antibodies are efficiently transferred to newborns, but their role in disease control is unknown. We administered neutralizing IgG, including the human neutralizing monoclonal IgG1b12, at levels insufficient to block infection, to six newborn macaques before oral challenge with simian-HIV strain SF162P3 (SHIV(SF162P3)). All of the macaques rapidly developed neutralizing antibodies and had significantly reduced plasma viremia for six months. These studies support the use of neutralizing antibodies in enhancing B cell responses and viral control in perinatal settings.

Successful introduction of Macaca nemestrina infants to their mothers after cesarean delivery.

Four Macaca nemestrina infants delivered via cesarean section were introduced to their mothers after surgery. All 4 introductions were successful, although methods differed slightly between dam-infant pairs. Pairs were considered successful when the mother displayed affiliative behavior towards the infant (including grooming), cradled it ventrally, and nursed it sufficiently to maintain infant health. The dams were sedated lightly with ketamine prior to introduction to reduce the possibility of aggression to caregivers and infants. The dams were checked for lactation, and each infant was swabbed with its placenta and with its mother's vaginal secretions prior to placement in the dam's cage. During the initial exposure, all 4 mothers picked up their infants within 1.5 h after introduction. Three of the 4 dam-infant pairs were fully successful during the initial exposure (24 h postdelivery), that is, the infants began to nurse within 2.5 h of affiliative contact. The 4th dam-infant pair required 3 d of successive exposures before the infant was nursed adequately. Infant health and maternal behavior determined the length of exposure. The optimal duration of these introductory encounters appeared to be between 2 and 3.5 h, to allow sufficient time for the dam's recovery from sedation while avoiding adverse effects on infant health. These observations demonstrate that cesarean-delivered M. nemestrina infants can be successfully united with their mothers, although it sometimes may require prolonged exposures on successive days.

The use of CD 34(+) mobilized peripheral blood as a donor cell source does not improve chimerism after in utero hematopoietic stem cell transplantation in non-human primates.

In utero hematopoietic stem cell transplantation is a therapeutic procedure that could potentially cure many developmental diseases affecting the immune and hematopoietic systems. In most clinical and experimental settings of fetal hematopoietic transplantation the level of donor cell engraftment has been low, suggesting that even in the fetus there are significant barriers to donor cell engraftment. In postnatal hematopoietic transplantation donor cells obtained from mobilized peripheral blood engraft more rapidly than cells derived from marrow. We tested the hypothesis that use of donor hematopoietic/stem cells obtained from mobilized peripheral blood would improve engraftment and the level of chimerism after in utero transplantation in non-human primates. Despite the potential competitive advantage from the use of CD 34(+) from mobilized peripheral blood, the level of chimerism was not appreciably different from a group of animals receiving marrow-derived CD 34(+) donor cells. Based on these results, it is unlikely that this single change in cell source will influence the clinical outcome of fetal hematopoietic transplantation.

Fetal immune suppression as adjunctive therapy for in utero hematopoietic stem cell transplantation in nonhuman primates.

In utero hematopoietic stem cell transplantation could potentially be used to treat many genetic diseases but rarely has been successful except in severe immunodeficiency syndromes. We explored two ways to potentially increase chimerism in a nonhuman primate model: (a) fetal immune suppression at the time of transplantation and (b) postnatal donor stem cell infusion. Fetal Macaca nemestrina treated with a combination of the corticosteroid betamethasone (0.9 mg/kg) and rabbit thymoglobulin (ATG; 50 mg/kg) were given haploidentical, marrow-derived, CD34+ -enriched donor cells. Animals treated postnatally received either donor-derived T cell-depleted or CD34+ -enriched marrow cells. Chimerism was determined by traditional and real-time polymerase chain reaction from marrow, marrow progenitors, peripheral blood, and mature peripheral blood progeny. After birth, the level of chimerism in the progenitor population was higher in the immune-suppressed animals relative to controls (11.3% +/- 2.7% and 5.1% +/- 1.5%, respectively; p = .057). Chimerism remained significantly elevated in both marrow (p = .02) and fluorescence-activated cell sorted and purified CD34+ cells (p = .01) relative to control animals at > or = 14 months of age. Peripheral blood chimerism, both at birth and long term, was similar in immune-suppressed and control animals. In the animals receiving postnatal donor cell infusions, there was an initial increase in progenitor chimerism; however, at 6-month follow-up, the level of chimerism was unchanged from the preinfusion values. Although fetal immune suppression was associated with an increase in the level of progenitor and marrow chimerism, the total contribution to marrow and the levels of mature donor progeny in the peripheral blood remained low. The level of long-term chimerism also was not improved with postnatal donor cell infusion.

Trisomy 16 in a pigtailed macaque (M. nemestrina) with multiple anomalies and developmental delays.

A female pigtailed macaque (Macaca nemestrina) with unusual physical characteristics, deficits in learning and cognitive tasks, abnormal social behavior, and abnormal reflexes and motor control was followed from birth until 3 years of age and found to have trisomy 16, which is homologous to trisomy 13 in humans. The animal described here showed similar features to cases of trisomy 16 and 18 (human trisomy 13 and 18, respectively) reported previously in nonhuman primates. However, both significant differences and similarities were found when compared with the homologous human trisomy. Evaluation of the genetic components of these disorders as well as systematic developmental evaluation can lead to new insights into the genetic basis of speciation, development, and the underlying differences between humans and their closest living relatives.