Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Bison”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 559 records · Page 31Linked to original sources
PubMed1996

The toxic and abortifacient effects of ponderosa pine.

Ponderosa pine needles cause abortion and a poorly described toxicosis when eaten by cattle. In previous trials, the abortifacient compound of pine needles was identified as isocupressic acid. At abortifacient doses, isocupressic acid caused no other toxicosis. However, other pine needle fractions, similar in composition to several commercially available rosin products, caused no abortion but were very toxic. The purpose of this study was to describe the toxicoses of ponderosa pine, compare its toxicity with other rosin and related pine products, and identify the toxin. Four groups of three pregnant beef cows each were treated with either ponderosa pine tips, rosin gum, dehydroabietic acid, or ground alfalfa. The cows treated with pine tips aborted, had retained placentas with endometritis, and developed both renal and neurologic lesions. The cattle treated with rosin gum or dehydroabietic acid did not abort but developed similar signs and lesions of intoxication. Clinical signs of intoxication included anorexia, mild rumen acidosis, dyspnea, paresis progressing to paralysis, and death. Clinical biochemical results, suggestive of renal, hepatic, and muscular disease, included azotemia, hypercreatinemia, hyperphosphatemia, proteinuria, and marked elevations of various serum enzymes. Histologically, all poisoned animals had nephrosis, vacuolation of basal ganglia neuropil with patchy perivascular and myelinic edema, and skeletal myonecrosis. The alfalfa-treated controls were normal. These findings suggest that ponderosa pine needles and tips are both abortifacient and toxic. Because the lesions caused by pine tips, rosin gum, and dehydroabietic acid are similar, toxicosis is most likely due to the diterpene abietane acids, common in all three.

Abietanes↗
PubMed2006

Spatial and temporal variability modify density dependence in populations of large herbivores.

A central challenge in ecology is to understand the interplay of internal and external controls on the growth of populations. We examined the effects of temporal variation in weather and spatial variation in vegetation on the strength of density dependence in populations of large herbivores. We fit three subsets of the model ln(Nt) = a + (1 + b) x ln(N(t-1)) + c x ln(N(t-2)) to five time series of estimates (Nt) of abundance of ungulates in the Rocky Mountains, USA. The strength of density dependence was estimated by the magnitude of the coefficient b. We regressed the estimates of b on indices of temporal heterogeneity in weather and spatial heterogeneity in resources. The 95% posterior intervals of the slopes of these regressions showed that temporal heterogeneity strengthened density-dependent feedbacks to population growth, whereas spatial heterogeneity weakened them. This finding offers the first empirical evidence that density dependence responds in different ways to spatial heterogeneity and temporal heterogeneity.

Animals↗
PubMed1999

[Dentascan computed tomography of the mandibular incisive canal. Its radiologic anatomy and the therapeutic implications].

PURPOSE: To stress the importance of CT depiction of the mandibular incisive canal. This anatomical structure contains a major neurovascular bundle and is thus very important in the planning of mandibular implants in the canine-incisive area. MATERIALS AND METHODS: January through December 1998, sixty patients unselected by age and gender were submitted to mandibular CT. Axial slices were acquired with 1-1.5 mm thickness and 1 mm table feed, and the images were then reformatted with a dedicated dental software. Both the conventional and the Helical techniques were used. RESULTS: The incisive canal appears on Dentascan transverse reconstructions as a round low-density area within mandibular trabecular bone, which is surrounded by a higher-density rim representing the canal walls. This anatomical structure originates from the mental foramen and continues mesially to the mental symphysis. The mandibular canal was visualized in 95% of cases bilaterally (57/60); the incisive canal was depicted on the left side in 41.6% of cases (25/60) and on the right side in 51.6% (31/60). CONCLUSIONS: The importance of careful assessment of the mandibular canal course before implantology is now widely recognized. The same holds true for the canine-incisive region in the jaw, to detect the incisive canal if present and prevent any complications from its accidental damage. CT with a dedicated software showed the incisive canal in a large number of patients, which calls for precise reporting of its presence, course, and relationships with teeth.

Female↗
PubMed2002

A new technique for hard tissues.

Fossil tissues generally require specialized processing. Most thin sectioning techniques yield unstained sections or require unwieldy methods to produce stained sections. I outline here two simple techniques for producing stained, ground, thin sections using readily available Romanowsky-type cytology stains and a urine sediment stain. Results are comparable to hematoxylin and eosin stained specimens.

Animals↗
PubMedDate not supplied

Abdominal recurrence of ovarian cancer: value of abdominal MR in patients with positive CA125 and negative CT.

PURPOSE: To evaluate the role of abdominal MR in the diagnosis of ovarian cancer recurrence in patients with increasing serum Ca-125 levels and negative abdomino-pelvic CT scan. MATERIALS AND METHODS: In a period of about 30 months, 22 patients in follow-up for ovarian carcinoma (stages II, III-IV) with increasing levels of Ca-125 and negative abdomino-pelvic CT scan were studied with abdomino-pelvic MR. All patients had a disease-free interval of at least 6 months after cytoreductive surgery and chemotherapy. MR examinations were performed with T1- and T2-weighted SE and FSE sequences in the axial and coronal planes, before and after Gadolinium administration. Tumour recurrence was confirmed at surgery, percutaneous biopsy and by monitoring progression or remission of the disease with clinical examination, Ca-125 serum levels and integrated imaging (CT and MR) during and after medical therapy. RESULTS: MR imaging demonstrated recurrence of the disease in 16 of the 22 patients, 3 of the remaining 6 patients were true negatives, whereas 3 patients were false negatives (in one case the CT and MR studies missed the peritoneal seeding found at surgery performed 1 month after the MR; in 2 cases both the CT and MR scans became positive for abdominal recurrence after 3 and 4 months respectively). The sensitivity and diagnostic accuracy of MRI were 84% (16/19) whereas specificity was 100% (3/3). The positive predictive value was 100% (16/16) whereas the negative predictive value was 50% (3/6). CONCLUSIONS: In a selected population of women with increasing serum Ca-125 levels and negative abdominal CT, MR imaging could supply earlier information about the presence and location of recurrences with a high impact on further decisions regarding the choice of therapeutic options (surgical or medical). The limited number of patients requires additional studies to confirm these resuts.

Abdominal Neoplasms↗
PubMedDate not supplied

Inhibitory effect of different enterocins against fecal bacterial isolates.

Anti-microbial activity of five different enterocins produced by ruminal and environmental enterococci against fecal bacterial isolates was tested. The majority of all 61 strains (80.4%) were inhibited by all enterocins used. The remaining strains were inhibited at least by one enterocin. The highest activity, 51,200 arbitrary units per ml-1 (AU ml-1) was measured when crude extracts of enterocin V24 (CE V24) were used against enterococci. CE AL41 and EK13 showed an activity of 25,600 AU ml-1. The lowest activity was obtained with Enterocin CE EC24 (100-400 AU ml-1). Crude extract of enterocin CCM4231 inhibited the indicator strains with an activity ranging from 100 up to 6400 AU ml-1, which is in accordance with our previous results. It further indicates the probable use of enterocins or its producers in environmental biotechnology with the aim to increase the effectiveness of sanitation of animal excrements after standard treatment.

Animals↗