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Biomedical subjects

L Florence

Publications and source records attributed to L Florence.

8 recordsLinked to original sources
PubMed2006

Hoof growth and wear of semi-feral ponies during an annual summer 'self-trimming' period.

REASONS FOR PERFORMING STUDY: Despite growing interest in application natural models of hoof-maintenance in domestic horses, little data is available to describe natural conformation and proposed mechanisms of self-maintenance. OBJECTIVES: Quantitatively describe hoof growth and wear during a period of 'self-trimming' within a herd of semi-feral ponies. METHODS: Hoof length, growth and wear were measured for a sample of 40 animals during a period of 'self-trimming' from June through September, 2005. RESULTS: For front hooves, mean toe lengths in July, August and September were significantly less than in June. For the hind, mean toe length in August was significantly less than in June, July and September. Increased rate of wear, as opposed to decreased growth rate, was the major contributor to overall shorter hoof lengths. Cumulative wear expressed as a percentage of the June baseline toe length ranged from 21-57% (mean 38%) for the front and 12-46% (mean 32%) for the hind. CONCLUSIONS: Significant cracking, tearing and increased wear, known as 'self-trimming' is a measurable herd-wise phenomenon in horses maintained under natural social and environmental conditions. POTENTIAL RELEVANCE: Although just one example herd, these data provide quantitative support of anecdotal reports of 'self-trimming' as a mechanism contributing to natural self-maintenance of the equine hoof.

Animals↗
PubMed1997

Asialoglycoprotein/asialoglycoprotein receptor (AGP-AGPr) interaction is an important mechanism for the uptake of FK506 by hepatocytes.

Hepatic tissue concentrations of FK506 have been correlated with early acute rejection following liver transplantation. Asialoglycoproteins (AGP) reputedly bind FK506 in blood. AGP are removed from the circulation by the liver via the AGP receptor (AGPr), which resides on hepatocytes. This study was undertaken to determine if the AGP-AGPr mechanism enhances the delivery of FK506 to hepatocytes. Human orosomucoid (OM) was used as a representative AGP. asialoOM (aOM) was prepared by desialation of OM. Fresh rat hepatocytes were isolated by collagenase digestion. Tritium labeled FK506 (FK) was used to identify and quantitate FK506. Quantitation of FK in serum and culture media was by direct counting. FK in animal tissues used a method developed in our laboratory for the purpose. AGPr on resting hepatocytes was demonstrated by flow cytometry using FITC-orosomucoid and FITC-BSA controls. AGPr were enhanced by 2 g glucose/L. Two serum FK-binding fractions, 44 kD and 15 kD, were identified by gel filtration. Exogenous OM avidly bound FK and displaced FK activity from the 15 kD fraction. Serum (1%) and the 44 kD fraction enhanced the uptake of FK by hepatocytes, while serum depleted of OM-aOM by affinity chromatography was only 72.5% as effective as control serum; aOM enhanced the uptake of FK by hepatocytes to a degree similar to that of control serum but OM did not significantly affect the uptake of FK. Cold FK506 blocked the uptake and was dose dependent; cold CsA had no effect. Affinity extraction of OM from serum to which FK had previously been added removed 28.4% of FK activity. Following i.v. infusion, the kidney had the highest and liver the lowest tissue concentration of FK at 1 hr and 3 hr. In contrast, after oral administration the liver had the highest concentrations of the other tissues tested. The AGP-AGPr mechanism plays a significant role in the delivery of FK506 to hepatocytes and is likely responsible for the differences in bioavailability observed after oral and i.v. administration. Factors governing the AGP-AGPr mechanism are germane to understanding both the efficacy and toxicity of FK506 and the development optimal therapeutic strategies.

Administration, Oral↗
PubMed1996

Successfully treated invasive pulmonary aspergillosis associated with smoking marijuana in a renal transplant recipient.

Invasive pulmonary aspergillosis (IPA) is often a lethal entity in transplant recipients (up to 90%). We report the successful treatment of a case of IPA in a renal transplant recipient whose only risk for exposure was habitual marijuana smoking. Although marijuana smoking has been linked to the development of IPA in patients immunosuppressed for a variety of reasons, this case is the first report involving a solid organ transplant recipient. The patient's clinical course and treatment are described and the literature is reviewed with respect to environmental and patient risk factors. In this case, IPA was associated with the patient's heavy usage of marijuana during the immediate posttransplant period. Treatment was successful and included the experimental amphotericin product amphotericin B colloidal dispersion. Contemporaneous exposure to a large amount of inocula of Aspergillus within 30 days of receiving high doses of steroids appeared to be the most important factor that predisposed this patient to IPA. Transplant recipients should be specifically proscribed from marijuana use during periods of high steroid administration.

Antifungal Agents↗
PubMed1987

Regulatory mechanisms in endoluminal release of serotonin and substance P from feline jejunum.

The mechanisms controlling vagally induced 5-HT and SP release into the jejunal lumen were studied in the cat. In control animals, electrical vagal nerve stimulation doubled the rate of endoluminal secretion of 5-HT and SP. Propranolol pretreatment did not alter luminal secretion of these hormones. Atropine suppressed motor function and induced dose-related inhibition of vagal release of endoluminal 5-HT, but not of SP; the response to hexamethonium pretreatment was similar to that of atropine. In contrast, superior cervical ganglionectomy did not alter stimulated endoluminal 5-HT release but it completely abolished release into the portal vein. The portal 5-HT release was not affected by ganglionic blockade. The data suggest that vagally mediated 5-HT release into the lumen and the portal circulation are mediated by different neural mechanisms, the former cholinergic, the latter presumably adrenergic; and release of feline 5-HT and SP are independent, suggesting two intestinal sources, the EC cell for 5-HT and peptidergic neurons for SP.

Animals↗
PubMed1985

The influence of cholinergic and adrenergic blockade on the portal release of substance P in the cat.

The effect of efferent electrical stimulation of the divided thoracic vagus nerves on the release of substance P-like immunoreactivity (SPLI) into the portal vein was studied in anesthetized cats. Under basal conditions portal SPLI levels were fairly constant. During the first 5 min of vagal stimulation there was a significant increase of the portal plasma levels of SPLI. Since we have demonstrated that infracardiac vagal stimulation causes only minor changes in small intestinal bloodflow, a true vagal neurogenic release of SPLI seems likely. We have shown that SPLI is exclusively localized within feline gut neurons (not the enterochromaffin (EC) cells). Thus, SPLI released into the portal circulation probably represents overflow of transmitter into the circulation. Neither blockade of cholino- or adrenoceptors nor ganglionic blockade influenced the enhanced release of SPLI induced by vagal stimulation, suggesting activation of SP neurons via nonclassical receptors.

Animals↗
PubMed1985

Hepatocellular carcinoma. A 5 year institutional experience.

Liver cancer is the most common of all malignancies worldwide, its incidence reaching almost epidemic proportions in some countries. However, its significance in North America has generally been underemphasized. In a 5 year period, hepatocellular carcinoma was diagnosed in 35 adult patients in our institution. Preexisting liver inflammation was present in 27 of the patients (77 percent). Although most patients had symptoms, they included only poorly defined pain or cachexia in most cases, and 10 patients (29 percent) were totally asymptomatic at the time of diagnosis. Five patients presented with hemoperitoneum due to intraabdominal tumor rupture. Examinations useful in confirming the diagnosis included alpha-fetoprotein determination, liver scan, and computerized tomographic scanning. Eight patients (23 percent) had associated visceral or other malignancies. The outlook was poor, with a mean survival of 5 months, and only two patients survived more than 1 year. Hepatocellular carcinoma is uncommon but not at all rare in the Pacific Northwest. It arises from chronic liver inflammation, is diagnosed late, and has a grim prognosis. Prevention of various forms of chronic liver inflammation, and mass serial screening of populations at high risk for the development of hepatocellular malignancy will probably have the greatest role in reducing the lethality of this disease.

Adult↗
PubMed1980

The Tensilon test. A safe office procedure.

Myasthenia gravis in now known to be an autoimmune disorder in which damage of acetylcholine receptors takes place at the post-synaptic membrane. This new knowledge has improved therapy and placed a premium on early diagnosis. To overcome ophthalmologic reluctance to perform Tensilon testing, side effects of Tensilon are reviewed and a survey of the frequency of these side effects is reported.

Cardiovascular Diseases↗