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CD4+CD25+ regulatory T cells (Tregs) suppress immune responses to alloantigens. The in vivo circulation and tissue localization of Tregs during an adaptive immune response remain unclear. We noninvasively tracked luciferase-expressing Tregs over time in an allogeneic bone marrow transplant model and demonstrated colocalization with effector T cells and initial expansion in secondary lymphoid organs before migration into inflamed tissues. Inflammation induced by irradiation and the allogeneic setting provided crucial stimuli for early Treg expansion and migration, leading to parallel reduction of effector T-cell proliferation in lymphoid organs and peripheral tissues. Treg transplants conferred long-term protection from systemic inflammatory challenge consistent with Treg in vivo survival. Suppression occurred during multiple phases of inflammation, but is optimal in the initial phase, providing protection from graft-versus-host disease while maintaining the graft-versus-tumor effect even at physiologic doses of Tregs due to their in vivo expansion, hence overcoming a major barrier to potential clinical applications of Tregs given their rarity.

The objective was to compare a pre-synchronization protocol by induction of a dominant follicle using a progesterone intravaginal device before an Ovsynch protocol (Presynch) with Double-Ovsynch in lactating dairy cows. Lactating Bos indicus × Bos taurus crossbred cows (n = 440) were randomly allocated to 1 of 2 treatments (all IM injections): (1) Double-Ov (n = 228): GnRH (Day –17), prostaglandin F2α (PGF2α) 7 days later (Day –10) and gonadotropin-releasing hormone (GnRH) 3 days later (Day –7) followed by an Ovsynch protocol 7 days later (GnRH on Day 0, PGF2α on Day 7, GnRH on Day 9); (2) Presynch (n = 212): insertion of a sustained release progesterone intravaginal device (Day –10), 10 days later (Day 0), an Ovsynch protocol was initiated with progesterone device withdrawal on Day 7. All cows were artificially inseminated 15 to 20 h after the second GnRH injection of the Ovsynch protocol and were pregnancy checked by ultrasonography 30 and 60 days later. On a subsample (n = 102), ultrasonography was performed on Days 0, 7, 9, and 24 of the experimental period. On another subsample (n = 42), blood samples for progesterone analysis were taken on Days 0, 7, and 24. There were no differences between pre-synchronization methods on synchronization parameters [presence of a follicle >12 mm on D0, Double-Ov 94.2% (49/52) and Presynch 92.0% (46/50); P = 0.66], follicular diameter on the 1st GnRH (Double-Ov 17.2 ± 0.7 mm and Presynch 18.6 ± 0.9 mm; P = 0.28), ovulation rate to the 1st GnRH [Double-Ov 86.3% (44/51) and Presynch 81.2% (39/48); P = 0.50], synchronization rate [Double-Ov 84.6% (44/52) and Presynch 86.0% (43/50); P = 0.84], follicular diameter on the 2nd GnRH (Double-Ov 17.5 ± 0.6 mm and Presynch 18.0 ± 0.5 mm; P = 0.48), ovulation rate to the 2nd GnRH [Double-Ov 90.9% (40/44) and Presynch 86.0% (37/43); P = 0.48] and CL diameter on Day 24 (Double-Ov 27.9 ± 0.7 mm and Presynch 29.4 ± 0.9 mm; P = 0.19). Corpus luteum presence on Day 0 was different (P = 0.03) between treatments [Double-Ov 57.7% (30/52) and Presynch 36.0% (18/50)]. Moreover, there was no difference (P = 0.85) between pregnancy rates on Day 30 [Double-Ov 39.0% (89/228) and Presynch 40.1% (85/212)] or Day 60 after AI [Double-Ov 34.8% (79/227) and Presynch 38.7% (82/212); P = 0.41] and gestational loss between 30 and 60 days after AI [Double-Ov 7.9% (7/88) and Presynch 3.5% (3/85); P = 0.13]. Proportion of cows with P4 1 ng mL−1 on Day 7 [Double-Ov 77.3% (17/22) v. Presynch 95.0% (19/20); P = 0.14] and P4 concentration on Day 24 (Double-Ov 4.7 ± 0.6 v. P4-Ov 5.9 ± 0.9; P = 0.84) were similar between treatments. In conclusion, pre-synchronization by induction of follicular persistence using a sustained-release progesterone device before Ovsynch yielded similar results to the Double-Ovsynch protocol on follicular development and regression patterns and on the fertility of lactating dairy cows.

We studied the comparative feeding ecology of three species of colobus (Procolobus badius, Procolobus verus, and Colobus polykomos) on Tiwai Island, Sierra Leone. We collected dietary data on each species by scan-sampling habituated groups. Because these groups were observed in the same study area during overlapping time periods, the confounding effects of temporal and spatial variability in food availability were reduced. Our results show that the annual diets of the two larger species (Procolobus badius and Colobus polykomos) include roughly equal proportions of fruits (including seeds), young leaf parts, and mature leaf parts, although P. badius had a greater intake of floral parts. Procolobus verus consumed almost no mature leaf parts, few fruits and seeds, and many young leaf parts. Colobus polykomos commonly fed from lianas. Seeds were the dominant fruit item eaten by all three colobus, and the fruits they selected were generally dull and non-fleshy, in contrast to the brightly-colored, pulpy fruits eaten by guenons. Leguminous plants contributed substantially to the diets of both the larger species, but comparisons with other African forest sites indicate that colobine biomass is not closely correlated with the abundance of leguminous trees in the forest.

A group of Colobus polykomosat Tiwai, Sierra Leone, demonstrated seasonal flexibility in its diet, with seeds, young leaves, and mature leaves each dominating the diet at different times. Comparison of food consumption with phenological data indicates that seeds are eaten whenever available and are preferred to other foods, while young leaves are preferred to mature leaves. Colobus polykomosalso prefer liane to tree leaves, despite the relatively high quality of mature tree foliage at the Tiwai site. Analysis of protein, fiber, and energy values of foods selected and items available, but not eaten, suggests that preference is related to protein and energy maximization. Leguminous plants, especially Papilionaceae and Mimosaceae, are highlighted as important food sources for C. polykomos;seeds and leaves from these families have a high nitrogen content, and the protein content of leguminous seeds often equals or exceeds that found in leaves. It is predicted, therefore, that colobines living in habitats with a high density of legumes will feed heavily on seeds, subject to constraints such as seasonal availability. Where suitable leguminous species are less common, a mixture of fruits, seeds, and young or mature leaves or both is likely to be selected. The results of this and other recent studies of colobines do not support the notion that colobines are specialist folivores.

Summary Colobine monkeys are widely reported to spend considerable portions of their daily activity budgets resting. To test the hypothesis that resting and associated postures are related to energy conservation and thermoregulation, resting behaviours in Colobus polykomos are examined in relation to vegetation cover, weather conditions and diet. Seasonal differences in hunching are shown to be significantly correlated with cool, wet conditions and low energy intake, while postures associated with heat dissipation are more closely related to hot weather. These results support the hypothesis that C. polykomos are energy limited in wet seasons, and suggest their behaviourial thermoregulation is related not just to climatic conditions, but also to energy content and availability of food. Resume On a rapporte largement que les colobides passent une grande partie de leur temps a se reposer. Pour eprouver l'hypothese selon laquelle le repos et les attitudes qui s'y associent seraient lies a la conservation de l'energie et a la thermoregulation, on examine les comportements de repos chez Colobus polykomos en relation avec le couvert vegetal, les conditions atmospheriques et le regime alimentaire. On montre que les differences saisonnieres de la chasse sont significativement liees a des conditions fraiches et humides et a une faible absorption d'energie alors que les attitudes qui depensent de la chaleur sont plus etroitement liees au temps chaud. Ces resultats supportent l'hypothese que C. polykomos dispose d'une energie limitee en saison des pluies et suggerent que la thermoregulation active n'est pas liee uniquement aux conditions climatiques mais aussi au contenu energetique et a la disponibilite de la nourriture.

To explore sources of variation in tropical forest primate biomass, and, in particular, to test the hypothesis that soil conditions are a major ultimate determinant of the biomass of colobine monkeys and other primates, we compared data on the soils, vegetation, and primate community at a site in West Africa (Tiwai Island, Sierra Leone) with information from other sites, especially two other African sites (Douala-Edea in Cameroon, and Kibale Forest in Uganda). The biomass of eight anthropoid primate species in old secondary high forest on Tiwai was estimated from data on population densities assessed by transect samples combined with data on social group densities and individual body masses. Samples of soil and tree foliage were collected at the same site, and subjected to a variety of chemical and mechanical analyses. Our estimate of anthropoid biomass at Tiwai is 1229-1529 kg/kM2, including 682-889 kg/km2 of colobines. This is one of the highest primate biomasses recorded anywhere. The soils at Tiwai were found to be relatively high in sand content and low in pH, and to have low levels of mineral nutrients. Levels of condensed tannins in the mature foliage of the trees comprising a major part of the forest canopy were higher than at other sites, but the ratio of protein to fiber in this foliage was also higher than at any other site except Kibale. It is argued that a wide range of environmental factors affect primate population densities, and that nutrient-poor soils and high tannin levels in tree foliage do not necessarily produce a low primate (or colobine) biomass, as some earlier studies had suggested. Fur

Various methods are available for measuring the production of reactive oxygen species by phagocytes, but they are limited in their use by the need for their immediate application, cell isolation and of cell-activation by unphysiological stimuli. In addition, after measurement of reactive oxygen metabolites using oxidizing agents, the reduced compounds formed have to be determined during or immediately after their formation. In the present study, an improved cytochrome C assay was investigated which allowed measurements of superoxide anions in whole blood samples following activation of phagocytes by physiological stimuli such as the bacterial tripeptide N-formyl-methionyl-leucyl-phenylalanine (fMLP). The fMLP-stimulated production of superoxide anion (O(2)(-)) showed a sigmoidal-shaped fMLP dose-response curve, and constant O(2)(-) production rates (nmol.1(-1)x10(6) granulocytes) could be determined reliably up to a blood granulocyte concentration of 1 x 10(4) x microl(-1). To allow the determination of reduced cytochrome C later after its formation, the effect of long-term storage at -20 degrees C on the stability of reduced cytochrome C was tested up to 16 weeks. The results obtained show that the determination of reduced cytochrome C in whole blood represents a simple and reliable method. Most importantly, O(2)(-)-reduced cytochrome C can be frozen and stored without any alterations, at least up to 2 weeks. Thus the method seems to be superior to other methods of detection, especially when the experimental conditions do not allow immediate spectrophotometry (e.g. mountain medicine, space medicine). Under such conditions the present assay would allow reliable measurement of reduced cytochrome C, even after weeks of cryopreservation.

During the Last Glacial Maximum (LGM) ice flowed from the Cordillera Darwin Ice Cap through the study area (Fig. 1) to the Segunda Angostura in the Straits of Magellan [Caldenius,1932; Mercer, 1976; Porter, 1990; Porter, et. al., 1992; Clapperton,1993]. Recent work by Clapperton [1995] indicates that as many as five glacial advances occurred along the Strait of Magellan during the last glacial cycle, with the last advance tentatively occurring between 16,590 – 11,800 14C YBP.

1. Colobines are widely described as folivorous and a prediction of low basal metabolic rate appears to be supported by low activity levels, but energy budget estimates based on data from a field study of Colobus polykomos question these assumptions. 2. Annual diet and activity budgets are shown to change seasonally: unripe tree seeds are the preferred food type, with increased time spent feeding during the peak of seed production. Time spent resting is highest during wet seasons, when seeds are not available and only leaves are eaten. 3. The high energetic value of seeds compared to fruit flesh, young and mature leaves, is demonstrated. 4. Energy budgets are estimated for adult males and females (non-reproductive, pregnant and lactating), using daily energy expenditure (DEE) as maximum, and average daily metabolic needs (ADMN) as minimum values. 5. A simple model is employed to demonstrate that a diet of 100% seeds supplies sufficient calories for all estimates of energy intake and expenditure, whereas a diet of 100% leaves is unable to meet DEE and only the highest estimates of feeding rate (grams of leaves min-1) approach ADMN. 6. The advantages of detoxification, and the limitations of energy production for small-bodied fore-gut fermenters are outlined. 7. Evidence that C. polykomos is hypometabolic is considered, and it is concluded that the adaptations they show to periodic shortages of high energy foods are behavioural rather than physiological.

Equine infectious anemia virus (EIAV) contains a tat gene which is closely related to the trans-activator genes of the human and simian immunodeficiency viruses. Nucleotide sequence analysis of EIAV cDNA clones revealed that the tat mRNA is composed of three exons; the first two encode Tat and the third may encode a Rev protein. Interestingly, EIAV Tat translation is initiated at a non-AUG codon in exon 1 of the mRNA, perhaps allowing an additional level of gene regulation. The deduced amino acid sequence of EIAV tat, combined with functional analyses of tat cDNAs in transfected cells, has provided some unique insights into the domain structure of Tat. EIAV Tat has a C-terminal basic domain and a highly conserved 16-amino-acid core domain, but not the cysteine-rich region, that are present in the primate immunodeficiency virus Tat proteins. Thus, EIAV encodes a relatively simple version of this kind of trans activator.

SUMMARY Two-week-old turkey poults were necropsied 1, 2, 4, and 6 weeks after intravenous inoculation with Mycoplasma meleagridis. The organism was recovered, in decreasing order of frequency, from the lungs, bursa of Fabricius, air sacs, and hock joint. Gross lesions were confined to the air sacs and hock joints of 5 and 2 poults, respectively, of 16 examined. A mild synovitis was observed histologically in 8 of 16 poults. It was postulated that these lesions could be a predisposing factor in leg deformities in young poults.