Recurrent malignant chondroid syringoma of the foot: a case report and review of the literature.

Malignant chondroid syringoma, or mixed tumor of the skin, salivary gland type, is an uncommon neoplasm believed to originate in sweat glands. This neoplasm occurs mostly in women and is typically seen in the extremities and torso. A case of recurrent malignant chondroid syringoma of the right foot in a man aged 34 years is described with a review of pertinent literature. The surgically excised neoplasm was evaluated by routine histology, immunohistochemistry, and transmission electron microscopy. The malignant chondroid syringoma showed microscopic dermal satellite tumor nodules. Immunohistochemical staining was positive for keratin and S100 and negative for actin and p53. Ki-67 showed <10% positive staining. Ultrastructurally, the neoplasm was composed of epithelial cells with tonofilaments, cell junctions, and electron-dense amorphous keratin-like substance in the intercellular spaces. No evidence of myoepithelial differentiation was noted. Given the tumoral size, acral location, and histologic findings, the neoplasm was classified as a malignant chondroid syringoma. After reviewing the literature, it became apparent that wide surgical excision, adjuvant radiation therapy as well as patient education are critical in facilitating long-term survival.

Effect of energy and protein density of prepartum diets on fat and protein metabolism of dairy cattle in the periparturient period.

To determine if increased nutrient density in prepartum diets improves nutrient balance of peripartum cows, we blocked 40 Holstein cows and 40 heifers by expected date of parturition and assigned them randomly within blocks to one of four treatment diets varying in density of net energy for lactation (NEL) and crude protein (CP). Diets were 1.30 Mcal of NEL/kg and 12.2% CP, 1.49 Mcal of NEL/kg and 14.2% CP, 1.61 Mcal of NEL/kg and 15.9% CP, and 1.48 Mcal of NEL/kg and 16.2% CP. These diets were fed ad libitum from 25 d prepartum until parturition, and all cows were fed the same diet after calving. Increased nutrient-density of prepartum diets did not decrease feed intake. Compared to animals fed the lowest density, those fed the highest density consumed more NEL (20 vs. 14 Mcal/d) and gained more body condition, backfat, and body weight. They also had less nonesterified fatty acids in plasma (176 vs. 233 microM) and more insulin-like growth factor-I in plasma (472 vs. 390 ng/ml) during the last 2 wk prepartum and less triglyceride in liver at parturition (0.9 vs. 1.5%, wet tissue basis). Quadratic effects of energy density were not observed, and the addition of protein in the medium energy diet had no effect. Prepartum diets did not alter any variables during lactation. In conclusion, increasing the energy and protein density up to 1.6 Mcal of NEL/kg and 16% CP in diets during the last month before parturition improves nutrient balance of cattle prepartum and decreases hepatic lipid content at parturition.

Seed localization in eye plaque brachytherapy.

We describe a simple method for localizing seeds in eye plaques used for brachytherapy treatment of intraocular tumors and age-related macular degeneration. The method is based on obtaining magnified photocopy images of plaques with seeds in place and then using simple geometrical considerations to reconstruct seed coordinates with about 2% accuracy. A spreadsheet program is used for reconstruction and dosimetric calculations.

Dry cow diet, management, and energy balance as risk factors for displaced abomasum in high producing dairy herds.

The objective of this study was to determine prepartum risk factors for displaced abomasum. The design was a prospective study of 1170 multiparous Holstein cows from 67 high producing dairy herds in Michigan. Each farm was visited four times within a 6-wk period. At each visit, data on nutrition and management were collected. All multiparous cows within 35 d of projected calving were assigned a body condition score, and blood was sampled to determine the concentration of nonesterified fatty acids in plasma. A multivariable linear regression model was used to determine risk factors associated with the incidence of displaced abomasum during lactation on a herd basis. A multivariable logistic regression model with random effect was used to determine risk factors for displaced abomasum on an individual cow basis. Significant risk factors for displaced abomasum included a negative energy balance prepartum (as estimated from plasma nonesterified fatty acids), a high body condition score, suboptimal feed bunk management prepartum, prepartum diets containing > 1.65 Mcal of net energy for lactation/kg of dry matter, winter and summer seasons, high genetic merit, and low parity.

Comparison of growth hormone-releasing factor and somatotropin: lipid and glucose metabolism in dairy cows.

Lactating, primiparous Holstein cows were continuously infused for 63 d with either recombinant growth hormone-releasing factor or recombinant bST or were not infused (control). The releasing factor and bST treatments reduced fat synthesis from acetate and lipoprotein lipase activity in omental adipose tissue. Also, both treatments increased hormone-sensitive lipase activity per gram of adipose tissue and reduced fatty acid esterification per milligram of protein in adipose tissue. Protein concentration in adipose tissue with both treatments was greater than that of the control, although the protein concentration was less in adipose tissue from cows treated with the releasing factor than from those treated with bST. In mammary tissue, releasing factor increased fat synthesis from acetate more than did bST treatment, but percentages of fat or short-chain fatty acids in milk were not different between treatments, nor were differences significant between treatments and control for fatty acid esterification or lipoprotein lipase activity in mammary tissue or gluconeogenesis and fatty acid esterification in liver. We conclude that protein concentration was lower in omental adipose tissue of cows treated with releasing factor than that in tissue of cows treated with bST, although both treatments similarly suppressed synthesis of fat from acetate and activity of lipoprotein lipase.

Reduction of bovine plasma cholesterol concentration by partial interruption of enterohepatic circulation of bile salts: a novel hypocholesterolemic model.

Interruption of enterohepatic circulation (EHC) of bile salts in several species is known to cause a significant decrease in plasma concentrations of low density lipoprotein (LDL) cholesterol, but to have little effect on high density lipoprotein (HDL) cholesterol. The present study, for the first time, demonstrates that partial interruption of EHC dramatically reduces both plasma LDL and HDL cholesterol concentrations in cattle. Five adult Holstein cows were surgically altered to allow controlled portions of bile flow to be diverted from the body. The animals were fed a low-fat, cholesterol-free diet. In two experiments, bile was diverted at 50% and 22% of total flow rates. By day 8 of diversion, both rates reduced mean plasma cholesterol from baseline (85 mg/dl) to about 8 and 18 mg/dl, respectively. Cholesterol was reduced in equal proportions in all lipoprotein fractions. In addition, plasma concentrations of triglycerides and phospholipids were also dramatically reduced. All of these plasma lipids returned to baseline within 1 week after restoration of bile flow. To determine the hepatic response to bile diversion, liver cholesterol concentrations, cholesterol synthesis rates, and LDL receptor-binding activities were determined in biopsy samples. In response to bile diversion, hepatic cholesteryl esters were markedly depleted while hepatic cholesterol synthesis rates were increased by more than 10-fold. Nevertheless, because the basal cholesterol synthesis rate was so low, it was estimated that the increase in synthesis would have supplied no more than 5% of the sterols depleted during bile diversion (1.2 vs. 25 mmol/day). LDL receptor-binding activity was significantly elevated, suggesting an increased uptake of plasma lipoprotein cholesterol by the liver. These results suggest that the unique sensitivity of bovine plasma cholesterol to enterohepatic circulation interruption might occur as a result of the inherently low rate of hepatic cholesterol synthesis in cattle. This hypocholesterolemic model might serve as an interesting tool for the study of factors regulating plasma HDL cholesterol.

Metabolic relationships in the supply of nutrients for milk protein synthesis: integrative modeling.

The objective of research under the NC-185 regional project is to identify the critical chemical transformations in the rumen, digestive tract, gastrointestinal and splanchnic tissues, and adipose and mammary tissues that define patterns of nutrient utilization in lactating dairy cows. This objective includes research on differences in fermentation, digestion, absorption, and tissue utilization of nutrients in sufficiently different situations to permit estimation of parameters defining various nutrient interconversions. The regional project is utilizing dynamic, mechanistic models of metabolism as tools for integrative analyses of experimental data generated by the group. During the early phases of the project emphasized herein, primary emphasis was on development of models of adipose tissue, mammary gland, liver, rumen, and whole animal metabolism. Serious inadequacies exist in the detail and scope of knowledge of rates of chemical transformations across the wide range of milk yields and nutrient intakes found in production situations. Current knowledge, as described in the various equations and parameters in the models, is presented and discussed. Some characteristics of the current models are illustrated, and methods to utilize the models to identify important experiments are discussed. More cooperative efforts are necessary, including experimental designs that focus on quantification of relationships between input and output, physiological mechanisms that alter patterns of nutrient utilization in lactating dairy cows, and yield estimates of the parameters describing the pre- and postabsorptive uses of feed nutrients.

Metabolism of long chain fatty acids by ruminant liver.

The primary source of fatty acids processed by ruminant liver is nonesterified fatty acids (NEFA) from blood. Uptake is regulated by concentration of NEFA and blood flow. Blood NEFA concentration increases with negative energy balance. Blood flow increases with energy intake. Uptake and secretion of triacylglycerol between blood and the liver is limited. The reason for limited hepatic secretion of triacylglycerol-rich lipoprotein is unclear but probably involves the secretory process, not synthesis of triacylglycerol or apolipoprotein. Oxidation of fatty acids and ketogenesis are inhibited by malonyl-CoA and propionic acid. The stress of late gestation and early lactation increases NEFA supply to the liver, where they cause deposition of fat. Ketogenesis and oxidation in the liver increase but not sufficiently to prevent an accumulation of fat, which may contribute to decreased feed intake in the peripartum period.

Therapy of diseases of ruminant intermediary metabolism.

Diseases of intermediary metabolism include ketosis and fatty liver of dairy cattle and pregnancy toxemia of ewes. These conditions occur when there is a failure of the homeostatic mechanisms regulating the mobilization of fats and the conservation of carbohydrates. The therapeutic approach is to reestablish the normal homeostatic patterns of fuel utilization. Suppression of excessive ketogenesis is the most important factor in reestablishing homeostasis. Ketogenesis can be suppressed by a number of therapeutic agents that act either by suppressing the mobilization of fatty acids or by inhibiting the transport of fatty acids into the hepatic mitochondria, the site at which fatty acids are converted to ketone bodies. Useful therapies include bolus glucose infusions, glucose precursors, and glucocorticoids.

Food intake and serum insulin responses to intraventricular infusions of insulin and IGF-I.

Previous studies reported that intracerebroventricular (ICV) infusion of insulin decreased food intake in rats and baboons. Insulin can bind to insulin-like growth factor I (IGF-I) receptors and mimic the response of IGF-I. Our objective was to determine the effects of ICV infused-insulin or IGF-I on food intake in sheep. In the present study, a 6-day ICV infusion of insulin (123 ng/kg of body weight/day) but not of IGF-I (123 ng/kg of body weight/day) decreased food intake by 40% (p less than 0.003) and body weight (p less than 0.015) compared with control sheep. In addition, sheep that received ICV insulin or IGF-I had only half the concentration of insulin in serum as compared with controls. Our results support the hypothesis that ICV insulin does not decrease food intake through IGF-I receptors. Nevertheless, apparently both insulin and IGF-I in the brain can influence the concentration of insulin in blood.

Lipid nutrition.

Cows in early lactation or producing more than 80 lb of milk per day need supplemental fat and can benefit from it. Fat should be added to the diet over a period of several weeks to allow the cows to become accustomed to it. Feed intake should be monitored because additional fat may decrease feed intake and offset the benefit of the fat. Supplemental fat should not exceed 4 to 5% of the dry matter intake. The first 2% of added fat should be supplied by oilseeds under most circumstances. The next 1 or 2% can come from commodity fat if availability and handling ability permits its use. If the last increment of fat is needed, it should be supplied by specialty fats that have been processed to improve ruminal inertness. Extra calcium, magnesium, and ruminally undegraded protein should be added to the diet when fat is added. Fat is a more expensive source of energy than feed grains in most of the world and should not be used beyond needs.

Effect of somidobove sustained release administration on the lactation performance of dairy cows.

Lactation performance was determined on 190 multiparous Holsteins from five herds supplemented with 0, 320, 640, or 960 mg of somidobove every 28 d. The experiment consisted of 21 d of pretreatment and treatment periods of various lengths, depending upon stage of lactation of animals at first administration. Somidobove beginning in early (28 to 45 d in milk), mid (111 to 166 d in milk), or late (166 to 334 d in milk) stages of lactation consisted of 9, 6, or 3 administrations. Milk and 3.5% FCM yields were increased by each dose of somidobove in all stages. Milk composition and dry matter and energy intakes were similar among treatments within stage. Milk to DMI ratio and milk energy to net energy intake ratio were improved by somidobove. Gain was positive for all treatments, but less in somidobove-supplemented cows. Lower body weight and condition score at the completion of somidobove treatment resulted. For early cows, days to first estrus and days to first breeding were similar; however, total number of inseminations for cows receiving somidobove was twofold greater than control, resulting in a longer calving interval. Results demonstrated efficacy of somidobove administered every 28 d to lactating dairy cattle for increased milk yield.

Influence of energy balance and body condition on estrus and estrous cycles in Holstein heifers.

The objective was to determine effects of energy balance and body condition on estrous behavior and estrous cycles in Holstein heifers. Before the experiment heifers were fed so body condition remained moderate or they became fat. During the 2 x 2 factorial experiment, moderate and fat heifers were in positive or negative energy balance. Heifers were fed individually twice daily, and energy balance was calculated daily. Heifers were observed for 30 min every 3 h, and all standing and mounting events were recorded for three consecutive estrous cycles. When progesterone in serum was less than 1 ng/ml, standing and mounting activity were profiled. Area, peak, and duration of activity profiles were examined among groups of heifers. Negative energy balance or fat body condition did not reduce peak or duration of estrous behavior and thus did not reduce detectability of estrus. Onset of diestrus was delayed in heifers that were fat and in negative energy balance relative to other heifers. We suggest that fat body condition, coincident with negative energy balance, may reduce accuracy of timing artificial insemination relative to ovulation and may consequently reduce fertility in cattle.

A species comparison of liver slice synthesis and secretion of triacylglycerol from nonesterified fatty acids in media.

The ability of liver slices from eight species to synthesize and secrete triacylglycerol from nonesterified fatty acids contained in media was investigated. Species were grouped according to the relative proportion of lipogenesis occurring in the liver. The rate of liver triacylglycerol synthesis from nonesterified fatty acids in media was similar among species studied. Liver slices from species in which the liver contribution to lipogenesis is minor (sheep, cattle, pig and guinea pig) secreted less triacylglycerol synthesized from nonesterified fatty acids than did liver slices from species in which lipogenesis occurs predominantly in the liver (chicken and fish) or in liver and adipose tissue (rat and rabbit). The results suggest that the ability of liver to secrete triacylglycerol in very low density lipoproteins is proportional to the liver's lipogenic capacity.

Energy balance and body condition influence luteal function in Holstein heifers.

A factorial experiment was conducted to determine influence of energy balance (EB) and body condition (BC) on luteal function in heifers. Heifers with moderate (MBC) or fat (FBC) BC were fed individually to sustain positive EB (PEB) or to cause negative EB (NEB). Intake of feed was measured daily and body weight weekly. Progesterone was quantified daily in serum for 3.5 estrous cycles. On days 9, 10, or 11 after fourth estrus, blood was sampled every 15 min for 12 hr to quantify luteinizing hormone (LH), growth hormone (GH), insulin and non-esterified fatty acids (NEFA). The next day, luteal cells were incubated and proportions of small to large cells were determined. After fourth estrus, area of progesterone profiles in serum for 10 days postestrus was reduced in all heifers relative to MBC-PEB heifers. But, luteal weight from FBC-PEB and MBC-NEB heifers was less than MBC-PEB heifers and FBC-NEB heifers were intermediate. Secretion of progesterone in vitro was increased by LH for PEB but not NEB heifers. MBC-NEB heifers had increased ratios of small to large luteal cells. Independent of BC, NEB decreased concentrations of insulin and increased GH and NEFA. Secretion of progesterone was not associated with LH, GH or insulin, but was correlated negatively with NEFA. We conclude that reduced concentrations of progesterone in serum of FBC-PEB and MBC-NEB heifers is due to impaired luteal development. But, reduced concentrations of progesterone in serum of NEB heifers is due also to reduced basal (MBC) and LH-induced (MBC and FBC) secretion of progesterone by luteal cells. Body condition at onset of NEB may determine when effects of NEB on progesterone are detected.

Effects of Rumen-Mate on lactational performance of Holsteins fed a high grain diet.

Three Latin-square trials were conducted to determine the effects of supplementing Rumen-Mate, a commercial buffer containing KCl, NaCl, and Mg and Na carbonates, on lactation performance of Holsteins. Cows were fed a basal ration of 40% corn silage and 60% concentrate in Trials 1 and 2, and 40% corn silage, 55% concentrate, and 5% alfalfa hay in Trial 3 (DM basis). In Trial 1, treatments were: basal diet, or basal diet supplemented with either 1% NaHCO3, or 1, 3, or 4.4% Rumen-Mate. Increasing dietary Rumen-Mate resulted in a linear increase in milk fat production and concentration with no difference between 1% Rumen-Mate and 1% bicarbonate. There was a significant linear decrease in milk protein concentration, but not production, with increasing concentrations of Rumen-Mate. In Trial 2 treatments were: basal diet, or basal diet supplemented with either .8% NaHCO3, 2.6% Rumen-Mate, .5% MgO, .8% NaHCO3 plus .5% MgO, or 1.8% Rumen-Mate plus .8% NaHCO3. Organic matter and CP intakes and milk protein yield and concentration were decreased by Rumen-Mate with a nonsignificant increase in milk fat concentration. Data from Trials 1 and 2 were combined with data from Trial 3, which compared basal diet, 1% bicarbonate, and 3% Rumen-Mate. The combined data showed a larger increase over basal diet in milk fat yield and concentration for 2.6 to 3% Rumen-Mate vs. .8 to 1% bicarbonate. Rumen-Mate did not decrease DM intake or protein yield relative to basal diet but did decrease protein yield 34 g/d compared with that of bicarbonate.

Effect on days of lactation and methionine hydroxy analog on incorporation of plasma fatty acids into plasma triglycerides.

Methionine hydroxy analog has been proposed to stimulate hepatic lipoprotein synthesis and incorporation of plasma fatty acids into plasma triglyceride. Seven cows were fed diets containing 0 or 30 g analog/d starting 14 d prepartum. At approximately 30 and 60 d postpartum, cows were continuously infused intravenously with 1-[14C] palmitic acid for 160 min to achieve steady-state labeling of plasma fatty acid and triglyceride. Turnover of fatty acid and transfer quotients for triglyceride and CO2 were 3.3 and 2.7 mmol min-1; 13.0 and 10.0%; and 8.0 and 5.0%, for control and analog, respectively. Proportion of fatty acid turnover incorporated into triglyceride and CO2 were 14.0 and 15.0%; and 21.0 and 18.0, respectively, for control and analog. Analog increased 14C recovered in milk fat (52 vs. 36%). Plasma concentration of fatty acids, percent oxidized to CO2, and percent of CO2 from fatty acids decreased with increasing lactation days. Milk fat percent and yield, fatty acid turnover, and oxidation were positively correlated with concentration of plasma fatty acids, whereas fatty acid incorporated into plasma triglyceride was negatively correlated with fatty acid concentration. The data suggest that hepatic triglyceride secretion is not increased in early lactation; further, no effects of analog on lipid metabolism were detected.

Milk fat depression and the influence of diet on milk composition.

Milk composition depends on inheritance, stage of lactation, age, infection, and diet. Fat is the most variable component of milk, and its concentration depends on the supply of acetate, butyrate, and performed fatty acids to the mammary gland. This supply depends on diet and competition among organs. Adequate, effective fiber is the critical dietary consideration.

Turnover of hepatic and plasma triacylglycerol in sheep.

Contributions of the intestine and liver to triacylglycerol (TG) formation from endogenous fatty acids were investigated in sheep. Cannulation and sampling of the intestinal lymph ducts and portal veins of two mature, nonpregnant ewes followed by an i.v. dose of 100 microCi of [14C]palmitate into a mesenteric cannula suggested intestinal contribution to endogenous TG production to be of no consequence. Turnover rates of TG within the plasma, hepatic microsomal and hepatic fat droplet compartments of four wethers averaged 20 +/- 8, 7.8 +/- 1.5 and 2.3 +/- .8 mg.h-1.kg body weight-1, respectively. A large, relatively inert pool of fat droplets with a slow turnover contained between 80 and 90% of the total hepatic TG. Hepatic TG concentration and turnover rates within the hepatic microsomal and fat droplet pools were inversely (r = -.86) and positively (r = .99) correlated, respectively, indicating that hepatic secretion of TG as lipoprotein was decreased as hepatic TG concentration increased. The model developed from these figures suggest that 40% of the plasma TG turnover is of endogenous origin and that this percentage value decreases when hepatic TG content is increased.

Mammary lipoprotein lipase in plasma of cows after parturition or prolactin infusion.

Plasma lipase activity from the mammary vein and a tail blood vessel was measured in periparturient Holstein cows treated in one of three ways: control, CB154 (2-Br-alpha-ergocryptin) or CB154 plus prolactin. CB154 administration decreased basal serum prolactin concentration by 80% and blocked the normal parturient increase of serum prolactin. In CB154 plus prolactin-treated cows, prolactin was infused continuously for six days starting five and eight days prepartum. Plasma lipase activity was not detectable up to 26 hr prepartum in control and CB154-treated cows or before the start of prolactin infusion in CB154 plus prolactin-treated cows. After two hr prepartum, plasma lipase activity was detected in all treatments. In CB154 plus prolactin-treated cows, plasma lipase activity was detected in the presence of high concentrations of serum progesterone four days after the start of prolactin infusion and at least two days before parturition. Plasma lipase activity was four times greater in the mammary vein than in the tail vessel at sampling times at which activity was detected in both vessels. We propose the difference between plasma lipase activity from the mammary vein and tail vessel is due to release of lipoprotein lipase from the mammary gland into blood, and this activity can be induced prepartum by prolactin or at parturition even if the parturient increase in prolactin is suppressed.