The effects of feeding sows at onset of farrowing supplemental energy (blend of carbohydrates and glycerol) on farrowing kinetics and piglet vitality.

Delivering piglets is one of the most energy-demanding activities sows undergo in their lifetime. Sows can have myometrial contractions from 2 to 12 h before the first piglet is expelled as well as a nest-building behavior. Thus, when the first piglet is delivered, the female has already used part of her energy supply. When the sow gets exhausted due to lack of energy, the farrowing process can be interrupted, causing damage to the viability and vitality of the piglets. In the present study, we evaluated the effects of feeding sows an energy supplement at the onset of farrowing on farrowing kinetics and piglet vitality. The energy supplement consisted of a blend of carbohydrates and glycerol which provides 439 kJ of metabolizable energy per kg of metabolic weight. A total of 180 sows were used. At the onset of farrowing, sows were assigned to one of the following treatments: sows that were not supplied energy at the onset of farrowing, serving as controls (CON, n = 85); sows fed the energy supplement at the onset of farrowing (ESP, n = 95). Farrowing kinetics, blood glucose concentration, and piglet vitality were recorded for each sow. Blood glucose concentration was assessed by puncturing the auricular vein and using a portable glucometer at four different time points: after the birth of the 1st piglet (T0), and at 20 (T20), 40 (T40), 80 (T80), and 180 (T180) min after the birth of the 1st piglet. The vitality of the 1st, 6th, 12th, 17th, and 20th piglet born was evaluated using the Apgar score. Piglet birth weight and average colostrum intake were measured. The farrowing duration was 20 min shorter (P < 0.05) for ESP sows in comparison with CON sows. Sows from ESP treatment had higher (P ≤ 0.05) blood glucose concentration at T20 and T40 compared to the CON sows. The inter-piglet birth interval was shortened (P < 0.05) by 14 min between the 1st and 2nd piglet for the ESP treatment. The 17th and 20th piglets born from ESP sows had higher (P < 0.05) Apgar score compared to piglets of the same birth order from CON sows. Colostrum intake was higher (P < 0.01) for piglets born from ESP sows. Litter growth performance did not differ (P > 0.05). In conclusion, feeding a blend of carbohydrates and glycerol as an energy supplement for farrowing sows improved farrowing kinetics and piglet vitality score.

Systematic review of the results of fenestrated endovascular aortic repair in octogenarians.

INTRODUCTION: With the increasing life expectancy of Western populations, more octogenarians are presenting with large abdominal aortic aneurysm (AAA). Endovascular repair offers a less invasive alternative and older patients who may not have been offered open repair in the past are now being considered for elective repair with this approach. Age in isolation may not be the only consideration in recommending elective aneurysm repair. We aimed to review the literature on complex endovascular AAA repairs (mainly fenestrated endovascular aortic repair [FEVAR]) in octogenarians. METHODS: A literature search was conducted using the Ovid Medline®, Embase® and Cochrane Library databases for articles published up to January 2022. All English language publications from 1995 onwards were eligible for inclusion. Search terms included: "FEVAR", "F-EVAR", "fenestrated EVAR", "fenestrated endovascular aortic repair", "fenestrated endovascular aneurysm repair", "fenestrated AAA repair", "fenestrated endograft", "fenestrated stent graft", "fenestrated", "endograft", "EVAR", "octogenarian", "elderly", "above 80" and "over 80". METHODS: The literature search identified 134 potential articles. Following qualitative assessment by two independent appraisers, this was refined to 11 studies, in accordance with the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) statement. RESULTS: The primary outcome measure was 30-day mortality, which was highly variable, ranging from 0% to 9% in octogenarians and from 0% to 5% in non-octogenarians. However, these differences were only found to be statistically significant in two studies. The secondary outcome measures included technical success rates, major adverse events, reintervention rates, freedom from reintervention, target vessel patency, freedom from target branch instability, and length of hospital and intensive care unit stay. No statistically significant differences were found between octogenarians and non-octogenarians. Long-term survival was significantly lower for octogenarians in two studies. CONCLUSIONS: The perioperative outcomes of FEVAR in octogenarians are comparable with those of younger patients. FEVAR therefore appears to be an acceptable option for complex endovascular aneurysm repairs in carefully selected octogenarians. Nevertheless, this review highlights the paucity of published data on the outcomes of endovascular repair of complex aneurysms in octogenarians.

Supplying sows energy on the expected day of farrowing improves farrowing kinetics and newborn piglet performance in the first 24 h after birth.

The farrowing process is one of the most energy-demanding activities for the modern hyperprolific sow. This study evaluated the effects of supply of energy on the expected date of farrowing on the farrowing kinetics and piglets' performance during the first 24 h after birth. A total of 80 sows were used. The sows and their respective litters were considered as the experimental unit. On the expected day of farrowing, the sows were allocated to one of the following groups: sows that did not have access to feed from farrowing induction until the end of the farrowing process (CON, n = 40); sows fed 500 g of energetic supplement, which consisted of 250 g of the basal lactation diet plus 250 g of cane sugar, 18 h after farrowing induction (SUP, n = 40). The farrowing duration, farrowing assistance, birth interval, number of total born, stillborn and mummified piglets were recorded for each sow. Piglets were weighed individually at birth and 24 h later. The interval from birth to first suckle was evaluated individually for each piglet in 16 randomly selected litters (eight litters per treatment group). Blood glucose concentrations of six sows were measured shortly after expulsion of the first piglet. Farrowing duration, farrowing assistance and stillborn rate tended to be greater (P = 0.06, P = 0.09 and P = 0.07, respectively) in sows from the CON group compared to sows from the SUP group. However, there was no difference (P > 0.05) between the groups for birth interval. Colostrum intake was greater (P < 0.05) for piglets from the SUP group compared to piglets from the CON group. Additionally, BW gain of the piglets suckling the SUP group was greater (P < 0.05) than those suckling the CON group at 24 h after birth. The blood glucose concentrations during the expulsive stage of farrowing were greater (P < 0.05) in the SUP group than for sows from the CON group. In conclusion, supplying modern hyperprolific sows energy on the expected day of farrowing is a valuable nutritional intervention to improve the farrowing kinetics and piglets' performance in early life.

Supplemental progesterone during early pregnancy exerts divergent responses on embryonic characteristics in sows and gilts.

Progesterone (P4) plays a key role in pregnancy establishment and maintenance; during early pregnancy, P4 stimulates the production and release of uterine secretions necessary for conceptus growth prior to implantation; therefore, exogenous P4 supplementation may improve embryo development. This study evaluated the effects of supplementation during early pregnancy with long-acting injectable progesterone or altrenogest on embryonic characteristics of sows and gilts. Thus, a total of 32 sows and 16 gilts were used. On day 6 of pregnancy sows and gilts were allocated to one of the following groups: non-supplemented; supplemented with 20 mg of altrenogest, orally, from days 6 to 12 of pregnancy; supplemented with 2.15 mg/kg of long-acting injectable progesterone on day 6 of pregnancy. Animals were killed on day 28 of pregnancy, and ovulation rate, embryo survival, embryo weight, crown-to-rump length, uterine glandular epithelium and endometrial vascularization were assessed. Treatments had no effect on pregnancy rate, embryo survival or endometrial vascular density (P > 0.05). Non-supplemented gilts presented larger and heavier embryos compared to gilts from supplemented groups (P < 0.05). Sows in the altrenogest group presented larger and heavier embryos compared to non-supplemented sows and sows supplemented with long-acting injectable progesterone. In conclusion, supplementation of sows and gilts with progestagen from day 6 of pregnancy can be used as a means to improve embryo survival without deleterious effects.

Central nervous system lymphoma in 18 dogs (2001 to 2015).

OBJECTIVES: To investigate the outcome of dogs with central nervous system lymphoma. MATERIALS AND METHODS: A multi-center, retrospective, observational study was conducted by reviewing medical records of 18 cases of central nervous system lymphoma from seven institutions. RESULTS: Diagnosis of lymphoma was made through cerebrospinal fluid analysis, histopathology, flow cytometry of the cerebrospinal fluid, and cytology of cerebrospinal fluid, lymph node or spleen with correlated imaging. A total of 15 of 18 dogs received specific treatment other than prednisone. Three dogs underwent chemotherapy and radiation therapy after surgical decompression, five dogs underwent chemotherapy, two dogs underwent radiation therapy after surgical decompression, three dogs underwent chemotherapy after surgical decompression and two dogs underwent radiation therapy and chemotherapy. Only one dog received prednisone, and two dogs did not receive any treatment. Overall, the median survival time was 171 days (range 1 to 1942 days). CLINICAL SIGNIFICANCE: Dogs receiving any type of treatment for central nervous system lymphoma lived longer than cases described in previous historical reports. Further studies are needed to elucidate the importance of specific treatment modalities.

Persistence and Retention of Porcine Reproductive and Respiratory Syndrome Virus in Stable Flies (Diptera: Muscidae).

We investigated the acquisition of porcine reproductive and respiratory syndrome (PRRS) virus by the stable fly (Diptera: Muscidae; Stomoxys calcitrans (L.)) through a bloodmeal, and virus persistence in the digestive organs of the fly using virus isolation and quantitative reverse-transcription PCR (qRT-PCR). Stable flies were fed blood containing live virus, modified live vaccine virus, chemically inactivated virus, or no virus. Stable flies acquired PRRSV from the bloodmeal and the amount of virus in the flies declined with time, indicating virus did not replicate in fly digestive tissues. Virus RNA was recovered from the flies fed live virus up to 24 h postfeeding using virus isolation techniques and 96 h using qRT-PCR. We further examined the fate of PRRSV in the hemolymph of the flies following intrathoracic injection to bypass the midgut barrier. PRRSV was detected in intrathoracically inoculated adult stable flies for 10 d using qRT-PCR. In contrast to what we observed in the digestive tract, detectable virus quantities in the intrathoracically inoculated stable flies followed an exponential decay curve. The amount of virus decreased fourfold in the first 3 d and remained stable thereafter, up to 10 d.

Effects of stress associated with weaning on the adaptive immune system in pigs.

This study was designed to investigate the effects of weaning age on specific components of the adaptive immune system in pigs. Twenty-three crossbred pigs were randomly assigned to 1 of 3 treatments: weaning at 14 (14D, n = 8), 21 (21D, n = 7), or 28 (28D, n = 8) d of age. Peripheral blood samples, obtained when pigs were 13, 15, 20, 22, 27, 29, and 35 d of age, were analyzed for peripheral blood cell percentages and concentrations of neutrophils, lymphocytes, T cell subsets, mature B cells, and plasma cortisol concentrations. For each of the 3 groups, weaning increased plasma cortisol concentrations (P < 0.001) and reduced BW percentage change (P < 0.017). Lymphocyte concentrations displayed a treatment effect for the 14D (P = 0.074) and 28D (P = 0.014) groups. Albeit inconsistent, lymphocyte concentrations were less in weaned pigs on the day after weaning than in pigs remaining on the sow or weaned at a younger age. Specifically, mature B cells (CD21(+)) and CD4(+)CD8(+) cells decreased (P < 0.05) after weaning at 28 d of age. Other differences occurred among treatments; however, the differences apparently were not associated with weaning. Based upon the immunological measures used in the present study, there was not an explicit benefit to the adaptive immune system for any weaning age. Early weaning did not negatively affect the adaptive immunological competence of pigs as determined by changes in populations of immune cells.

Assessment of Stomoxys calcitrans (Diptera: Muscidae) as a vector of porcine reproductive and respiratory syndrome virus.

Porcine Reproductive and respiratory syndrome (PRRS) is a globally significant swine disease caused by an arterivirus. The virus replicates in alveolar macrophages of infected pigs, resulting in pneumonia in growing pigs and late-term abortions in sows. Outbreaks occur on disparate farms within an area despite biosecurity measures, suggesting mechanical transport by arthropods. We investigated the vector potential of stable flies, Stomoxys calcitrans (L.) (Diptera: Muscidae), in the transmission of porcine reproductive and respiratory syndrome virus (family Arteriviridae, genus Arterivirus, PRRSV) under laboratory conditions. Stable flies were collected around PRRS-negative boar stud barns in North Carolina and tested for presence of the virus. Stable flies were collected on alsynite traps placed near the exhaust fan of the close-sided tunnel-ventilated buildings, suggesting blood seeking flies are attracted by olfactory cues. No flies were positive for PRRSV. We assessed transmission of the virus through an infective bite by feeding laboratory reared stable flies on blood containing virus and transferring them to naive pigs for subsequent bloodmeals. Transmission of the virus to naive pigs by infective bites failed in all attempts. The volume of blood contained within the closed mouthparts of the stable fly seems to be insufficient to deliver an infective dose of the virus. Stable flies are unlikely to transmit PRRSV from one pig to another while blood feeding. The fate of the virus after a bloodmeal remains to be determined.

Pharmacology of tetracycline water medication in swine.

Medicating drinking water with tetracycline is commonly used in swine production systems to treat and prevent disease outbreaks. However, little information is known of the pharmacokinetics of this medication in water formulations. Twenty-four barrows, divided into 1 control group (of nontreated animals) and 3 equally sized treatments groups (n = 6/group), were treated with tetracycline water medication for 5 d at 125, 250, and 500 mg/L. Blood samples were collected at 0 (prestudy), 4, 8, 12, 24, 32, 48, 56, 72, 80, 96, and 104 h after exposure. Data analyses consisted of a noncompartmental pharmacokinetic analysis and statistical analysis of steady state concentrations with repeated measures ANOVA and multiple-comparison testing to determine whether plasma concentrations differed among groups. Derived pharmacokinetic parameters were consistent with previously published feed and intravenous data. Plasma tetracycline concentrations at steady state were 0, 0.33, 0.47, and 0.77 microg/mL for 0-, 125-, 250-, and 500-mg/L exposures, respectively. Treatment group steady-state plasma concentrations were significantly different from plasma concentrations in control animals (P < 0.0001); however, whereas the 125- and 250-mg/L groups were significantly different from the 500-mg/L group (P < 0.0001), their mean plasma tetracycline concentrations did not differ from one another. Furthermore, the study showed that tetracycline oral bioavailability is very small. The dose response curve also shows that concentrations of plasma tetracycline increase linearly, yet not in a 1 to 1 ratio, to the direct increase in water medication dose.

Expression and localization of vascular endothelial growth factor and its receptors in pig corpora lutea during the oestrous cycle.

Expression and localization of mRNAs for vascular endothelial growth factor (VEGF), VEGF receptor 1 (Flt) and VEGF receptor 2 (KDR) (VEGFR-1 and VEGFR-2, respectively) were investigated in pig corpora lutea. Northern blot analysis of total RNA indicated hybridization of pig VEGF, VEGFR-1 and VEGFR-2 cDNA probes to mRNA transcripts of approximately 3.9, 7.0 and 5.0 kb, respectively. The expression of mRNAs for VEGF and its receptors during the luteal phase (days 4, 7, 10, 13 and 15 after the onset of oestrus) were assessed by northern blot analysis, and hybridization signals were normalized to expression of pig 18S rRNA. Relative hybridization signals of expression of VEGF mRNA appeared to be constant; however, expression of VEGFR-1 mRNA was low on day 4, increased on day 7, and was higher on days 10, 13 and 15 (P<0.05, compared with day 4). In contrast, no changes in expression of mRNA for VEGFR-2 were evident on days 4-13, but a decrease was detected (P<0.05) at day 15. In situ hybridization revealed that VEGF mRNA was localized predominantly in large luteal cells, whereas both VEGFR-1 and VEGFR-2 were localized to small cells. These data indicate that the VEGF system may be involved in the regulation of luteal vasculature throughout the lifespan of the corpus luteum. Although the expression of VEGF mRNA was unchanged during the luteal phase, variations in the expression of VEGFR-1 and VEGFR-2 mRNAs indicate that differential regulation of expression of the VEGF receptors may play a role in the control of VEGF-mediated vascular growth at different phases of development and maturation of the pig corpus luteum.

Cloning of pig prostaglandin F2alphaFP receptor cDNA and expression of its mRNA in the corpora lutea.

Changes in the expression and localization of luteal mRNA for PGF(2alpha) (FP) receptors may be critical in determining the luteolytic action of PGF(2alpha) in pig corpora lutea. In this study, a full-length FP receptor (FPr) cDNA was isolated and cloned from pig corpora lutea. This isolate (GenBank accession no. U91520) contains an open reading frame of 1086 bases coding for a protein of 362 amino acids with seven potential transmembrane domains. The predicted amino acid sequence of this isolate was 83% identical to the FPr amino acid sequence of other species including sheep, cattle and humans. Northern blot analysis showed the presence of an FPr message of about 5 kb in mRNA from pig corpora lutea. Relatively weak FPr mRNA expression was detected on day 4 and day 7 of the oestrous cycle. The expression was greater (P < 0.05) on days 10, 13 and 15 than on days 4 and 7. In situ hybridization analysis revealed that mRNA for FPr was expressed predominantly in the steroidogenic large luteal subtype of cell, although there was some expression in small luteal cells, with histological appearance of steroidogenic small cells. Localization of hybridization signals of FPr was observed in luteal tissue at all stages examined. These data demonstrate that FPr is expressed in pig corpora lutea throughout the oestrous cycle and that upregulation of the FPr mRNA occurs when the corpora lutea becomes sensitive to PGF(2alpha). Direct luteal targets of PGF(2alpha) appear to be primarily large steroidogenic cells in this species.

Calcium and digoxin vs. calcium alone for severe verapamil toxicity.

UNLABELLED: Calcium chloride (CaCl(2)) is ineffective in severe calcium channel antagonist overdoses. Digoxin increases intracellular calcium by inhibiting the sodium-potassium adenosine triphosphatase enzymes. OBJECTIVE: To examine the effect of calcium and digoxin on the treatment of verapamil toxicity. METHODS: Sixteen dogs were instrumented to monitor hemodynamics. Verapamil toxicity (50% decrease in mean arterial pressure) was induced with verapamil (VER) at 6 mg/kg/hr and maintained for 30 minutes by titrating the VER rate. Following toxicity, the dogs received either digoxin (0.018 mg/kg) (DIG) (n = 8) or saline (No-DIG) (n = 8). Both groups received VER at three sequential rates (1 mg/kg/hr from 0 to 90 min, 6 mg/kg/hr from 90 to 130 min, and 18 mg/kg/hr from 130 to 170 min). Calcium boluses were given (500 mg at 0 and 15 min; 1 g at 140, 150, and 160 min). Data were analyzed using a repeated-measures analysis of covariance comparing DIG vs No-DIG across the infusion rates and time. Animal weight, does of VER administered during the toxicity phase, and baseline values were included as covariates. Mortality rates were compared at 230 minutes following a total dose of 500 mg of VER. RESULTS: The DIG group had a higher systolic blood pressure (SBP) than the No-DIG group during the 1-mg/kg/hr (early p = 0.028, late p = 0.01), 6-mg/kg/hr (p = 0.051), and 18-mg/kg/hr (p = 0.038) VER infusion rates. There were no deaths in the DIG group and four deaths in the No-DIG group (Fisher = 0.08). Neither ventricular tachycardia nor ventricular fibrillation developed in either group. Other hemodynamic parameters did not show significant changes. CONCLUSIONS: In a model of severe verapamil toxicity, digoxin plus calcium raised SBP and did not result in ventricular arrhythmias when compared with calcium alone.

The effect of hyperglycemia on cocaine neurotoxicity and death in mice.

OBJECTIVE: Cocaine toxicity frequently manifests as seizures and status epilepticus. Frequently, dextrose is administered to patients with cocaine-induced seizures. The objective of this study was to examine the effect of pre-existing hyperglycemia on cocaine neurotoxicity and death in mice. METHODS: Swiss albino mice received intraperitoneal dextrose at a dose of 1 g/kg (12.5%) (hyperglycemic group, n = 98). The euglycemic group (n = 98) received an equal volume of 0.9% saline. After 60 minutes, all the animals received intraperitoneal cocaine at a dose of 90 mg/kg. The times to onset of ataxia, seizure, and death were recorded in seconds. Times to events were compared using a Kaplan-Meier method and results were compared using the logrank test. The overall percentage outcomes were compared using chi-square. RESULTS: The ataxia rates (hyperglycemic 97%, euglycemic 97%, chi(2) = 0, p = 1), seizure rates (hyperglycemic 85%, euglycemic 82%, chi(2) = 0.292, p = 0.589), and survival rates (hyperglycemic 62%, euglycemic 51%, chi(2) = 0.2514, p = 0.113) were similar between the groups. The survival following a seizure was significantly higher in the hyperglycemic group (hyperglycemic 57%, euglycemic 41%, chi(2) = 4.439, p = 0.035). The median ataxia time was earlier in the hyperglycemic group (190 sec) than in the euglycemic group (166 sec) (p = 0.031). Seizures occurred no earlier in the hyperglycemic group (331 sec) than in the euglycemic group (342 sec) (p = 0.207). Survival times were not different for the hyperglycemic group (9,133 sec) and the euglycemic group (7,593 sec) (p = 0.394). Survival times following seizures were not different for the hyperglycemic group (8,095 sec) and the euglycemic group (5,816 sec) (p = 0.0752). CONCLUSIONS: In mice with pre-existing hyperglycemia, ataxia occurred earlier and survival following cocaine-induced seizures was longer than for euglycemic mice. No significant difference in the overall percentage of seizures and death was detected. Pre-existing hyperglycemia had minimal effect on worsening cocaine toxicity in mice.

Effects of feed physical form and buffering solutes on water disappearance and proximal stomach pH in swine.

The effects of the physical form of feed on water disappearance and the effects of buffered water on proximal stomach pH in swine were determined in two experiments. In Exp. 1, 32 barrows were used to evaluate the water disappearance in pigs fed a finely ground and pelleted diet vs those fed a coarsely ground and mashed diet for ad libitum consumption over a 2-wk interval. There were four replicates with eight pigs per replicate. Average daily water and feed disappearance did not differ (P = 0.06 and P = 0.10, respectively). However, average daily water to feed ratio was higher for pigs on the pelleted diet (4.21+/-0.31 L/kg vs 3.04+/-0.33 L/kg; P = 0.02). The higher ratio for the pelleted diet indicated that this may be the cause of a more fluid digesta allowing reflux of irritants from the distal stomach to damage the pars esophageal region of the proximal stomach. In Exp. 2, four barrows (25+/-2 kg) had gastric cannulas surgically implanted into the proximal region of the stomach. Pigs were given ad libitum access to a finely ground and pelleted diet. The experimental design was a Latin square. Water treatments included water (control), 200 mOsm NaHCO3, 250 mOsm NaHCO3, and 250 mOsm mono-dibasic sodium phosphate. Pigs were given a 4-d adjustment period, and pH measurements began on the morning of the 5th d and continued for 24 h under normal feeding conditions. Feed was removed and measurements were continued for 16 h. Buffered water raised the pH of the proximal region of the stomach compared to the control (P < 0.001). Average pH while consuming the water treatments was 3.65+/-0.11 (n = 4) for water control, 4.86+/-0.11 (n = 4) for the 200 mOsm NaHCO3, 4.63+/-0.11 (n = 4) for the 250 mOsm NaHCO3, and 4.59+/-0.14 (n = 3) for the 250 mOsm mono-dibasic sodium phosphate. Buffers also raised the pH of the proximal region of the stomach for the fed (P < 0.001) and the feed restriction (P < 0.01) phases of the trial. Water disappearance rates in pigs given NaHCO3 were higher than in the control (P < 0.01). Average daily water disappearance for the treatments was 9.13+/-0.74 L for the control, 13.56+/-0.74 L for 200 mOsm NaHCO3, 13.77+/-0.74 L for the 250 mOsm NaHCO3, and 10.33+/-0.95 L for the phosphate buffer. The proximal pH of the stomach was increased by adding buffers to the water supply. Addition of NaHCO3 buffers also caused increased water disappearance.

Experimental Salmonella typhi infection in the domestic pig, Sus scrofa domestica.

The domestic pig, Sus scrofa domestica, was examined as a model for typhoid fever, a severe and systemic disease of humans caused by Salmonella typhi. Six pigs were inoculated 1 week post-weaning with approximately 10(10)colony forming units (cfu) of wild type Salmonella typhi strain ISP1820 intranasally and observed for 3 weeks. S. typhi was cultured from the tonsils of 50% of the pigs at necropsy. Cultures from all other organs analysed (ileum, colon, spleen and liver) were negative. No clinical or histopathological signs of disease were observed. Pigs inoculated in parallel with swine-virulent S. choleraesuis all exhibited signs of systemic salmonellosis indicating that the parameters of the experimental infection with S. typhi (e.g. route) were appropriate. Whereas the pig has a gastrointestinal tract that is very similar to humans, our results indicated that the unique features of host and microbe interaction needed to produce typhoid fever were not mimicked in swine. Nevertheless, our observation of tonsillar involvement was consistent with former observations of S. choleraesuis and S. typhimurium infections in swine and supports a role for the tonsil in all porcine salmonella infections.

The hemodynamic effects of cocaine during acute controlled hemorrhage in conscious rats.

BACKGROUND: Cocaine is often associated with trauma; however, little is known about how its use alters the response to blood loss. The effect of cocaine on hemodynamics following acute hemorrhage was studied in a rat model. METHODS: Following baseline measurements, rats were administered either intravenous cocaine, or saline as a control. Both groups then underwent arterial catheter hemorrhage of 30% of total blood volume. Outcome variables include blood pressure, heart rate, hematocrit, pH, PCO2, PO2, and serum bicarbonate. RESULTS: Following hemorrhage, blood pressure decreased in both groups but the hypotension was significantly greater in the saline group than the intravenous cocaine group at 0 and 5 minutes posthemorrhage. Heart rate was increased significantly for the intravenous cocaine group compared to the saline group starting at 15 minutes postcocaine and lasting for the next 25 minutes. No difference was noted for hematocrit, pH, PO2, or serum bicarbonate. CONCLUSION: Although transient, cocaine blunted the hypotensive response to acute controlled hemorrhage and resulted in tachycardia.

Effects of immune challenge on concentrations of serum insulin-like growth factor-I and growth performance in pigs.

This study was designed to determine the long-term effects of repeated endotoxin treatment or immunization against human serum albumin on concentrations of serum insulin-like growth factor-I (IGF-I) and other indicators of growth performance in growing pigs. Thirty gilts (38.5 +/- 0.9 kg) were randomly assigned to 5 treatment groups (n = 6 animals/group): 1) lipopolysaccharide injections, 2) lipopolysaccharide pair-fed, 3) human serum albumin immunization, 4) human serum albumin pair-fed, and 5) control. Pigs in the lipopolysaccharide group were treated intramuscularly with lipopolysaccharide on Days 0-3. The pigs in the human serum albumin group were immunized with human serum albumin emulsified in Freund's adjuvant on Day 0 and administered a booster on Day 28. The lipopolysaccharide pair-fed pigs were matched by body weight and pair-wise fed with pigs treated with lipopolysaccharide. Similarly, human serum albumin pair-fed pigs were matched to human serum albumin immunized pigs. Serum IGF-I concentrations did not differ between or within groups. There was no difference in feed disappearance between groups prior to the initiation of treatments. The lipopolysaccharide group had a decrease (P = 0.013) in feed disappearance on Day 0 compared with control and human serum albumin groups. On Day 1, both lipopolysaccharide and human serum albumin groups differed (P < 0.05) from control. Average daily gain and total weight gain did not differ between groups; however, feed efficiency differed (P < 0.05) between lipopolysaccharide and control groups. Long-term effects of repeated endotoxin challenge or immunization on IGF-I concentrations and growth were not evident in the present study. This failure presumably was due to the development of endotoxin tolerance and a relatively innocuous vaccination against human serum albumin.

PGE receptor characteristics on porcine luteal cells during the estrous cycle and early pregnancy.

This study examined the affinities and concentrations of prostaglandin E (PGE) receptors on porcine luteal cells during the estrous cycle and early pregnancy. Corpora lutea (CL) were obtained from nonpregnant gilts at days 9 (n = 4), 12 (n = 3), and 14 (n = 6); three gilts possessed red, vascular CL and three gilts had white nonvascular CL) of the estrous cycle, and days 9 (n = 4), 12 (n = 3), 14 (n = 5), and 30 (n = 5) of pregnancy. The CL were dissociated enzymatically to disperse single cells and the red blood cells were removed by elutriation. The luteal cells were assayed for specific PGE binding by displacement analysis with use of [3H] PGE2 and varying concentrations of unlabeled PGE2. The specific binding of [3H] PGE2 to luteal cells decreased (p < 0.05) from days 9 to 14 of the estrous cycle, but only decreased (p < 0.05) from days 9 to 12 of pregnancy. Specific binding was higher (p < 0.05) on day 14 of pregnancy than the comparable stage of the estrous cycle. The affinities of PGE receptors decreased (p < 0.05) only on the luteal cells dissociated from red, vascular CL of day 14 nonpregnant gilts compared with those of other days of the estrous cycle and pregnancy. The number of PGE receptors on porcine luteal cells was similar (p > 0.05) in pregnant and nonpregnant gilts, but decreased (p < 0.05) on days 12-14 postestrus. During early pregnancy, it was evident that high affinity PGE receptors are sustained on porcine luteal cells; however, the role of the PGE receptors in maternal recognition of pregnancy remains speculative.

Shigella infection as observed in the experimentally inoculated domestic pig, Sus scrofa domestica.

The domestic pig, Sus scrofa domestica, was investigated as a potential animal model for shigellosis. We examined the effects of pig age, pig breed and antibiotic pretreatment upon Shigella infection. Shigella dysenteriae, and Shigella flexneri (both virulent and avirulent strains) were utilized. Our results indicated that young (4-week-old), conventionally re ared, domestic pigs were routinely, but briefly, colonized (average=3.5+/-2.5 days) following oral or gavage administration ofS. flexneri, as determined by direct rectal cultures. The duration of S. dysenteriae colonization was significantly shorter. Inoculation of younger (2 days) or older (9 weeks) pigs with S. flexneri had no significant effect on infection duration. Similarly, infection of 4-week-old pigs with virulent and avirulent strains of S. flexneri had no effect upon the duration of infection, nor did the use of a swine-passaged S. flexneri isolate. Marked clinical, histopathological (gross and microscopic) and immunoIhistopathological signs of disease were absent in all infections. However, in instances where microscopic histopathological evidence was used to correctly identify infected pigs, tonsillar lesions were the consistently noted criteria. The tonsils are believed to be an important portal of entry for Salmonella choleraesuis, another member of the Enterobacteriaceae and a prevalent pig pathogen. Taken altogether, our results indicate that the domestic pig is unsuitable as a model for shigellosis.

Effects of LH, prostaglandin E2, 8-bromo-cyclic AMP and forskolin on progesterone secretion by pig luteal cells.

The present study examined the effects of LH, prostaglandin E2 (PGE2), 8-bromo-cyclic AMP (cAMP) and forskolin on progesterone secretion by small and large pig luteal cells. Corpora lutea were isolated from gilts (n > or = 3 per day) on days 9, 12 and 14 of the oestrous cycle and days 9, 12, 14 and 30 of pregnancy. After enzymatic dissociation of the corpora lutea, small and large luteal cells were obtained by elutriation. Culture plates (24-well) were then seeded with 150,000 small luteal cells or 30,000 large luteal cells per well in 1 ml M199 medium in the absence or presence of LH, PGE2, LH plus PGE2, 8-bromo-cAMP or forskolin. After 12 h of incubation, culture plates were centrifuged, and the supernatant collected and frozen for subsequent assay of progesterone. Differences within day were not detected between cyclic and pregnant gilts, and thus, results were combined for days 9, 12 and 14. Basal progesterone secretion by small luteal cells was less (P < 0.05) on days 14 and 30 than days 9 and 12. Treatment with LH, PGE2, 8-bromo-cAMP or forskolin increased (P < 0.05) progesterone secretion by small luteal cells on days 9 and 12; however, treatments had no effect on days 14 and 30. Basal progesterone production by large luteal cells was less (P < 0.05) on day 30 compared with other days. PGE2 stimulated (P < 0.001) progesterone production by large luteal cells at all days. In contrast, 8-bromo-cAMP and forskolin inhibited progesterone production by large luteal cells on day 12 (P < 0.05), and day 14 (P < 0.001). These data show that pregnancy status does not alter luteal cell response to the aforementioned secretagogues. However, regulation of progesterone secretion differs between small and large luteal cells, and the age of the corpora lutea. Also, it is unlikely that the stimulatory actions of PGE2 involve increased cAMP production in pig large luteal cells.