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En el siguiente trabajo se revisa la evolución de los diferentes tratamientos invasivos de la litiasis que se ha producido en nuestro hospital en los últimos 15 años.

Eight ruminally cannulated ewes (four control and four bred; average BW = 85.7 kg), limit-fed alfalfa hay (1.86% BW), were used in two experiments to determine the effects of pregnancy and lactation on digestive function and serum metabolites. Seven-day sampling periods were used starting on d 102, 118 and 132 of gestation (Exp. 1) and d 14 and 32 of lactation (Exp. 2). Particulate (6.8 vs 4.9%/h; PPR) and fluid passage rates (13.9 vs 10.9%/ h) were greater (P< .05) and gastrointestinal mean retention time (28.9 vs 35.7 h) and fluid turnover time (FIT, 7.5 vs 9.5 h) were lesser (P< .05) in pregnant than in nonpregnant ewes, respectively. Isobutyrate concentration was lower (P< .05) in pregnant (1.7 mol/100 mol) than in nonpregnant (1.9 mol/100 mol) ewes. No differences (P> .10) were noted for any other ruminal fermentation measures between pregnant and nonpregnant ewes. In Exp. 2, no differences (P> .10) were noted in digesta kinetics or ruminal fermentation measures except for isobutyrate and isovalerate molar proportions and serum urea N (SUN) concentration. Isobutyrate, isovalerate and SUN concentrations (21.8 vs 26.1 mg/dl) were lower (P< .05) in lactating ewes than in nonlactating ewes. Gastrointestinal fill (5.7 vs 7.7 g/kg BW) and FIT (9.3 vs 12.7 h) were lesser and DM digestion (66.7 vs 57.4%) was greater (P< .05) in lactating than in nonlactating ewes. Data suggest that, during pregnancy, passage rate increases occur without affecting DM digestion and that, during lactation, PPR is not affected when ewes are limit-fed.

Prostaglandin F2α(PGF2α) is the physiological signal that triggers luteolysis in the non-pregnant ewe. This is associated with a decline in circulating levels of progesterone, beginning around day 14 of a 16–17 day estrous cycle. Recently, the receptor for PGF2α(FP) was cloned from an ovine day 10 large luteal cell cDNA library. The purpose of this study was to measure relative abundance of FP mRNA as it may change with luteolysis during the luteal phase. Corpora lutea (CL) were collected from ewes on day 10, 12, 14 or 16 (n≥4/day; day 0=synchronized estrus); 12 h after PGE2α-treatment on day 10, 12 or 14 (n≥3/day) of the estrous cycle; or on day 16 of pregnancy (n=6). Pregnancy was confirmed by visualization of the conceptus. Blood samples were collected 12 h prior to and at the time of tissue collection to determine levels of progesterone. Serum concentrations of progesterone declined with the onset of luteolysis in control animals (day 14, day 16;P<0.05) as well as 12 h following PGF2α-treatment (day 10, day 12;P<0.05). Genomic DNA from these tissues was prepared and visualized by agarose gel electrophoresis. Internucleosomal fragmentation (indicative of apoptosis) was seen in CL from animals in which luteolysis had been initiated (all PGE2α-treated and day 16 control ewes), but not in ewes with functional CL. Total RNA isolated from each CL was separated through a denaturing 1% agarose gel, transferred to nylon membranes and hybridized to a radioactive ovine FP cDNA probe. Hybridization to a radiolabeled 18S ribosomal cRNA probe was used to confirm equal loading of RNA in each lane. By northern analysis, a major transcript was seen at ∼6.1 kb. A relatively high level of FP mRNA was measured in CL collected from control non-pregnant ewes during the mid luteal phase (day 10, 2.73±0.17; day 12, 2.47±0.91; FP/18S ratio), but varied among animals (3.09±1.59) on day 14. Administration of PGF2αresulted in the lowest amounts of FP mRNA on days 10, 12, and 14 (P<0.05). Amounts of FP mRNA were higher (P<0.05) on day 16 of pregnancy as compared to day 10 (by 1.9-fold) or to day 16 (by 5.9-fold) of the estrous cycle. From these observations we conclude that PGF2αor some event associated with luteolysis appears to down regulate amounts of the FP mRNA. Furthermore, pregnancy, and/or the antiluteolytic signals associated with maternal recognition of pregnancy may prevent the decline in the amount of FP mRNA.

The brown planthopper, Nilaparvata lugens (Stal), is a major rice pest in Asia. Recently, a population of N. lugens was found thriving on Leersia hexandra Swartz, a weed grass common in ricefields. We studied orientational and settling responses, feeding behavior, metabolism of ingested food, growth, adult survival and egg production, oviposition, and hatchability of eggs of the two N. lugens populations on Taichung Native 1 (cv. TNl) rice (Oryza sativa L.) plants and on L. hexandra grass. TNl plants were best suited for the establishment of the rice-infesting population, and L. hexandra was a favorable host for the Leersia-infesting population. Individuals derived from one host did not thrive on the other host because of a significant reduction in feeding, assimilation of food, growth, longevity, and fecundity. Plant volatiles, extracted as steam distillates from TNl rice plants and L. hexandra grass, significantly affected the behavior and biology of rice- and grass-infesting N. lugens. The odor of TNl extract attracted rice-infesting N. lugens, whereas that of L. hexandra extract attracted grass-infesting N. lugens. The odor of TNl rice plants neither attracted nor repelled grass-infesting N. lugens individuals or vice versa. TNl extract was more toxic to the first instars and newly emerged females of grass-infesting N. lugens than the extract of L. hexandra. Similarly, L. hexandra extract was more toxic to the first instars and newly emerged females of rice-infesting N. lugens than TNl extract. Ingestion and assimilation of food by females of rice-infesting N. lugens were reduced on TNl plants treated with L. hexandra extract compared with those on plants treated with acetone or TNl extracts. Intake and assimilation of food by grass-infesting N. lugens were also significantly reduced on L. hexandra plants treated with TNl extract. However, feeding or assimilation by rice-infesting N. lugens on L. hexandra plants treated with TNl extract or grass-infesting N. lugens on TNl plants treated with L. hexandra extract remained unchanged. Gas chromatography analyses of steam distillates from TNl rice versus L. hexandra plants indicated several differences.

In a food preference chamber, fewer adults of red flour beetle (Tribolium Castaneum Herbst) settled in rice grain treated with 100, 500, or 1,000 ppm of the oil of turmeric Curcuma longa (L.), sweetflag Acarus calamus (L.), or neem Azadirachta indica A. Juss, or “Margosan-O” (a commercial neem-based insecticide). Repellency increased with increasing concentrations of the oils and Margosan. In another choice test, filter paper strips treated with turmeric oil or sweetflag oil at 200, 400, or 800 µg/cm2 repelled insects during the first 2 wk; thereafter, repellency decreased more rapidly than with neem oilor Margosan-O. Tribolium castaneum adults fed wheat flour, which had been treated with the test materials at 200 ppm, produced fewer and underweight larvae, pupae, and adults compared with the control.