Feeding ecology of the black howler monkey (Alouatta pigra) in northern Belize.

We studied the feeding ecology of the black howler monkey (Alouatta pigra) from March 1994 to April 1995 in the Community Baboon Sanctuary in northern Belize, Central America. Activity and diet composition were recorded using continuous focal animal sampling. Diet composition was compared with the relative abundance of plant parts eaten by the howlers within the study site. The study animals spent an average of 24.4% of their time feeding, 61.9% resting, and approximately 9.8% traveling. In contrast to previously published reports on A. pigra, we found the diet composition to be similar to that of other Alouatta species (conforming to the folivore/frugivore profile), with 41% of feeding time spent eating fruit, 45% foliage, and 11% flowers. This contrast may indicate a wide degree of dietary flexibility that allows A. pigra to inhabit a variety of habitat types. We suggest that a high level of resource abundance throughout the year makes the Community Baboon Sanctuary excellent habitat for Alouatta pigra.

Mineral and phytochemical influences on foliage selection by the proboscis monkey (Nasalis larvatus).

Primate diets may be influenced by the phytochemical composition of potential food resources. This study examined the protein, fiber, and mineral content of leaves from plant species used as food resources by the proboscis monkey (Nasalis larvatus) in Tanjung Puting National Park, Kalimantan Tengah, Indonesia. In addition, leaf samples were collected from nonfood resources based upon relative density in previously established vegetation plots. Higher concentrations of crude protein, phosphorus, potassium, and zinc were found in young leaves. Mature leaves had higher levels of magnesium, manganese and calcium compared to young leaves. Leaves from species used as food resources were significantly higher in protein (9.9% vs. 8.5%) and lower in fiber (30.5% vs. 40.0% acid detergent fiber) than the leaves from species not used as food sources. Food resources also contained higher concentrations of phosphorus and potassium; nonfood resources contained higher concentrations of calcium and manganese. Proboscis monkeys appear to follow the typical colobine trend: a diet relatively high in protein and low in digestion inhibitors (fiber). Little previous work has examined mineral content as a selection factor in primate food choices. Leaves from species used as food resources contained less calcium (0.35%), iron (34 mg/kg) and phosphorus (0.15%) than dietary standards established for captive nonhuman primates, but values were similar to those established for ruminant herbivores. Other mineral concentrations (potassium, magnesium, manganese, sodium, and zinc) met or exceeded recommended levels for both primates and ruminants. Comparison of diverse nutrients in native diets may provide insight into suitability of domestic animals models for providing adequate diets in captive feeding situations, as well as help define resource limitations in natural environments.

Techniques for cloning cDNAs encoding interactive transcriptional regulatory proteins.

Several approaches aimed at detecting and cloning interactive transcriptional regulatory proteins have been presented. All of the techniques can effectively identify specific interactions between two transcription proteins. However, interaction cloning and the two hybrid system have the added advantage of yielding a cDNA expression clone directly. The other methods, EMSA-mediated cloning, co-immunoprecipitation, oligonucleotide/PCR-facilitated cloning, Southwestern, and Farwestern, require additional manipulations to obtain a cDNA clone. Clearly, the interactive cloning system of choice will depend on the proteins under investigation.

Streptococcus bovis endocarditis and its association with colonic carcinoma.

Two cases of colonic carcinoma detected in patients with Streptococcus bovis endocarditis are presented. Neither patient had any complaints referable to the gastrointestinal tract; gastrointestinal evaluations were undertaken and colonic lesions were identified purely on the basis of the patients' underlying endocarditis. Both patients underwent successful surgery after completion of appropriate antibiotic treatment for S. bovis endocarditis. Results of a literature search for similar cases are presented. It is emphasized that all patients with S. bovis endocarditis should be evaluated for concomitant colonic carcinoma, even if they are totally asymptomatic.

Biogenic amines in cephalopod retina.

Biochemical and ultrastructural studies by previous workers have suggested dopamine as a candidate neurotransmitter for the centrifugal neurons present in the cephalopod retina. We have examined the retina in 3 species of cephalopod mollusc and find strong green bands of glyoxylic acid-induced fluorescence in the synaptic plexus region. These results, together with data obtained from our Golgi impregnations, help to confirm previous speculations that the centrifugal neurons are dopaminergic.

Injury to the portal vein: a hazard during common bile duct exploration.

Portal vein injury is an unusual but dramatic complication of biliary surgery. Unlike major arterial injury, this complication may, in carefully selected cases, be managed successfully without primary repair.