Serologic survey of domestic felids in the Petén region of Guatemala.

Blood samples were analyzed from 30 domestic cats (Felis domesticus) from the Petén region of Guatemala to determine the seroprevalence of common pathogens that may pose a potential risk to native wild felids. Eight of the cats had been vaccinated previously; however, owners were unable to fully describe the type of vaccine and date of administration. In addition, blood samples were obtained from two captive margays (Leopardus wiedii). Samples were tested for antibodies to feline immunodeficiency virus, Dirofilaria immitis, feline panleukopenia virus, feline herpesvirus, feline coronavirus, canine distemper virus, and Toxoplasma gondii and for feline leukemia virus (FeLV) antigen. Fifty percent or more of the cats sampled were seropositive for feline herpesvirus (22 of 30), feline panleukopenia (15 of 30), and T. gondii (16 of 30). Five cats were positive for FeLV antigen. Both margays were seropositive for feline coronavirus and one was strongly seropositive to T. gondii. All animals were seronegative for D. immitis. This survey provides preliminary information about feline diseases endemic to the Petén region.     

Renal adenocarcinoma, hepatocellular carcinoma, and pancreatic islet cell carcinoma in a binturong (Arctictis binturong).

A 19-yr-old binturong (Arctictis binturong) with acute upper respiratory disease was euthanized. Postmortem findings included hepatocellular carcinoma, pancreatic islet cell carcinoma, and renal adenocarcinoma with metastasis to the spleen, pleura, and pericardium. A link between primary hepatic and renal neoplasms has been noted in older humans.     

Porcine leptin inhibits lipogenesis in porcine adipocytes

The present study examined whether recombinant porcine leptin alters lipid synthesis in porcine adipocytes. The stromal-vascular cell fraction of neonatal pig subcutaneous adipose tissue was isolated by collagenase digestion, filtration, and subsequent centrifugation. These cells were seeded on 25-cm2 tissue culture flasks and proliferated to confluency in 10% (vol/vol) fetal bovine serum in Dulbecco's modified Eagle medium/F12 (DMEM/F12, 50:50). Cultures were differentiated using 2.5% pig serum (vol/vol), 10 nM insulin, 100 nM hydrocortisone. After 7 d of lipid filling, cultures were washed free of this medium, incubated overnight in DMEM/F12 containing 2% pig serum (vol/vol), and then used for experiments. Acute experiments assessed U-(14)C-glucose or 1-(14)C-palmitate metabolism in cultures exposed to porcine leptin (0 to 1,000 ng/mL medium) for 4 h. Chronic experiments used cultures incubated with 0 to 1,000 ng porcine leptin/mL medium for 44 h before measurements of U-(14)C-glucose and 1-(14)C-palmitate oxidation and incorporation into lipid. Another experiment examined whether chronic leptin treatment alters insulin responsiveness by including insulin (10 nM) with incubations containing leptin. Leptin had no acute effects on glucose oxidation or conversion to lipid (P > 0.05). Acute leptin treatment decreased palmitate incorporation into lipids up to 45% (P < 0.05). Chronic leptin exposure decreased glucose oxidation (21%), total lipid synthesis (18%), and fatty acid synthesis (23%) at 100 ng/mL medium (P < 0.05). Insulin increased rates of glucose oxidation, total lipid, and fatty acid synthesis (P < 0.05); however, chronic exposure to 10 ng leptin/mL medium decreased the effectiveness of 10 nM insulin to affect these measures of glucose metabolism by approximately 18 to 46% (P < 0.05). Higher concentrations of leptin inhibited all effects of insulin on glucose metabolism (P < 0.05). Chronic exposure to leptin increased palmitate oxidation by 36% (P < 0.05). Chronic leptin exposure decreased palmitate incorporation into total lipids by 40% at 100 ng/mL medium (P < 0.05). Lipoprotein lipase activity was not affected (P > 0.05) by leptin. These data indicate that leptin functions to promote partitioning of energy away from lipid accretion within porcine adipose tissue by inhibiting glucose oxidation and lipogenesis indirectly, by decreasing insulin-mediated stimulation of lipogenesis, and by stimulating fatty acid oxidation while inhibiting fatty acid esterification.     

Somatotropin and adipose tissue metabolism: substrate and temporal effects

The purpose of these studies was to determine the time course for changes in feed intake, blood metabolites, and lipogenic activity in adipose tissue in response to the initiation of porcine somatotropin (pST) treatment and following withdrawal from treatment in barrows. An initial study was conducted to determine the impact of chronic pST treatment (4 wk of daily injection; 0 vs 4 mg/d) on adipose tissue lipid metabolism in barrows (initial weight 67 kg). Feed efficiency was improved 27%, backfat thickness was decreased 43%, and glucose and lactate oxidation and incorporation into lipid in adipose tissue was reduced 70 to 86% in pST-treated pigs. Palmitate esterification was decreased 44%, whereas palmitate oxidation was unaffected. In vitro metabolism of lactate, glucose, and palmitate in liver slices was not affected by pST treatment. The time-course for changes in intake and adipose tissue metabolism in response to 7 d of pST (0 vs 4 mg/d) treatment and 7 d of withdrawal was examined in subsequent studies in barrows (initial weight 75 kg). Feed intake during pST treatment was significantly (P < .05) less than in control pigs within 24 h of the initiation of treatment and remained low through 3 d after withdrawal. Adipose tissue biopsies were obtained on d 0, 1, 2, 4, and 7 of the treatment phase and on d 2, 4, and 7 after withdrawal from 7 d of treatment. Maximal inhibition of lipogenesis by pST treatment in adipose tissue in vitro was observed on d 4 (-68%) and d 7 (-69%). Similarly, fatty acid synthase activity declined during the treatment period, with the greatest change noted on d 7 (-26%). After withdrawal from treatment, lipogenesis gradually increased, returning to control values 7 d after withdrawal. Levels of IGF-I began to increase from d 1 to d 7 of treatment, continually decreased during withdrawal, and were normalized by the end of the withdrawal period. Plasma urea nitrogen concentrations decreased during treatment, increased during the withdrawal phase, and were normalized 4 d after the last pST treatment. Overall results indicate that most of the metabolic changes in response to pST occur within 1 wk of treatment and return to pretreatment values after 7 d of withdrawal from treatment.     

GEOPHYSICS: Enhanced: A Strained Earth, Past and Present

Plate tectonics leads to deformation within converging or transforming plates, but the rates at which this happens are difficult to evaluate. In this Perspective, Ramsay highlights a new technique reported by Müller et al. for overcoming this problem in past and present mountain-building regions, which have particularly complex deformation patterns.     

Oral eosinophilic granulomas in tigers (Panthera tigris)--a collection of 16 cases.

Oral eosinophilic granulomas were diagnosed in 16 tigers (Panthera tigris). All lesions were located on the hard or soft palate and typically consisted of flat or slightly raised circular ulcers. Histologic features of these lesions were essentially identical to those seen in oral eosinophilic granulomas of domestic cats and dogs. No clinical signs were noted in eight cases, though various degrees of inappetence, excessive salivation, and dysphagia were noted in the other eight tigers. Six cases were not treated. Treatment for the remaining 10 cases centered on corticosteroids and additional treatments included surgical removal, cryotherapy, antibiotics, and chlorpheniramine. Treatment with corticosteroids did appear to be effective in some cases, though lesions would worsen after cessation of therapy and no cases were cured. In addition, three cases developed complications possibly related to this corticosteroid therapy. The etiology of these lesions remains unknown, though an underlying allergic condition is likely.