Characterization of Porcine Epidemic Diarrhea Virus Isolate US/Iowa/18984/2013 Infection in 1-Day-Old Cesarean-Derived Colostrum-Deprived Piglets.

Porcine epidemic diarrhea virus (PEDV) was first recognized in North America in April 2013 and has since caused devastating disease. The objective of this study was to characterize disease and viral detection associated with an original North American PEDV isolate inoculated in neonatal piglets. Thirty-six 1-day-old cesarean-derived and colostrum-deprived piglets were randomly assigned to the control (n = 16) or challenged group (n = 20); the latter were orogastrically inoculated with 1 ml of US/Iowa/18984/2013 PEDV isolate titered at 1 × 10(3) plaque-forming units per milliliter. Rectal swabs were collected from all piglets prior to inoculation and every 12 hours postinoculation (hpi) thereafter, with 4 control and 5 challenged piglets euthanized at 12, 24, 48, and 72 hpi. One piglet had a positive real-time quantitative polymerase chain reaction test on rectal swab at 12 hpi, and all remaining piglets were positive thereafter, with highest viral quantities detected at 24 and 36 hpi. Diarrhea was evident in 30% and 100% of challenged piglets at 18 and 24 hpi, respectively. Viral antigen was detected in enterocytes by immunohistochemistry in the duodenum and ileum of piglets euthanized at 12 hpi and was apparent throughout the small intestine of all piglets thereafter, with villus height:crypt depth ratios consistently below 4:1. Viremia was confirmed in 18 of 20 pigs at euthanasia. Clinical disease was severe and developed rapidly following infection with an original North American PEDV isolate, with lesions, viremia, and antigen detection possible by 12 hpi.

Pathogenesis of porcine epidemic diarrhea virus isolate (US/Iowa/18984/2013) in 3-week-old weaned pigs.

Porcine epidemic diarrhea virus (PEDV) is associated with clinical diarrhea in naïve swine of all ages. This report describes timing of antibody generation and disease progression following infection with a US PEDV isolate by assessing fecal viral shedding, morphometric analysis of intestinal lesions, and magnitude of immunohistochemical staining. Sixty-three, 3-week-old pigs were randomly allocated into control (n=27) and challenged (n=36) groups. Challenged pigs were administered 1 mL of 1 × 10(3) PFU/mL of US/Iowa/18984/2013 PEDV isolate by oro-gastric gavage. Three control and four challenged pigs were necropsied on days post-inoculation (dpi) 1, 2, 3, 4, 7, and weekly thereafter, until study termination on dpi 35. Clinical disease, fecal shedding, body weight, and temperature were monitored during the study period. Diarrhea was observed in challenged pigs beginning for some on dpi 2, affecting a majority of pigs by dpi 6 and subsiding by dpi 10. Average daily gain was significantly lower (P<0.001) for one week post-infection in challenged pigs. PEDV was detected in feces by PCR on dpi 1 and continued in a subset of pigs until dpi 24. PEDV-specific antigen was detected in villous enterocytes of challenged pigs by immunohistochemistry (IHC) on dpi 1, 2, 3, 4, 7, and 14. Microscopic lesions included severe diffuse atrophic enteritis with significantly reduced (P<0.001) villous length observed on dpi 3, 4, and 7. Under the conditions of this study, fecal shedding of PEDV and IHC staining can precede and continue beyond the observation of clinical signs, thus increasing the risk of viral transmission.

Vascular lesions in pigs experimentally infected with porcine circovirus type 2 serogroup B.

Vasculitis is a hallmark lesion of the severe form of systemic porcine circovirus-associated disease (PCVAD). In 2 experimental studies with porcine circovirus type 2 serogroup b (PCV2b), 2 pigs developed fatal PCVAD with acute vasculitis, and 5 related pigs developed chronic lymphohistiocytic and plasmacytic peri- and endarteritis. Five of these pigs (1 with acute vasculitis and 4 with chronic vasculitis) had also been inoculated with bovine viral diarrhea virus type 1 (BVDV1) or BVDV1-like virus. Vascular lesions were similar, independent of whether pigs had been inoculated singly with PCV2b or dually with PCV2b and BVDV1 or BVDV1-like virus. The acute vasculitis was accompanied by marked pulmonary and mesenteric edema and pleural effusion. In situ hybridization demonstrated abundant intracytoplasmic porcine circovirus type 2 (PCV2) nucleic acid in endothelial, smooth muscle-like, and inflammatory cells within and around affected arteries. The pigs with lymphohistiocytic and plasmacytic vasculitis had lesions of systemic PCVAD, including multisystemic lymphoplasmacytic and histiocytic or granulomatous inflammation. PCV2 nucleic acid was detected in renal tubule epithelial cells, mononuclear inflammatory cells, and rare endothelial cells in noninflamed vessels in multiple tissues of these animals. The 2 pigs with acute vasculitis had no PCV2-specific antibodies (or a low titer of), whereas the pigs with lymphohistiocytic and plasmacytic vasculitis developed high antibody titers against this virus. These observations suggest that (1) acute vasculitis observed in the current studies is directly caused by PCV2b, (2) chronic vasculitis may in part be mediated by the subsequent immune response, and (3) host factors and viral strain may both contribute to vasculitis in animals infected with PCV2b.

Cutaneous and systemic poxviral disease in red (Tamiasciurus hudsonicus) and gray (Sciurus carolinensis) squirrels.

From September 2005 through October 2006, fibromatosis was diagnosed in 2 red squirrels (Tamiasciurus hudsonicus) and 1 gray squirrel (Sciurus carolinensis). All 3 squirrels had multifocal to coalescing, tan, firm alopecic cutaneous nodules. Two squirrels also had pulmonary nodules. Histologically, the cutaneous nodules had marked epidermal hyperplasia, with ballooning degeneration of keratinocytes, spongiosis, and eosinophilic cytoplasmic inclusions. The dermis was expanded by proliferation of atypical mesenchymal cells with cytoplasmic inclusions. Additional findings included pulmonary adenomatous hyperplasia with cytoplasmic inclusions, renal tubular epithelial hyperplasia with cytoplasmic inclusions, atypical mesenchymal proliferation in the liver, and atypical mesenchymal proliferation with cytoplasmic inclusions in the seminal vesicles. Ultrastructurally, poxviral particles were observed in skin scrapings and sections of cutaneous and pulmonary nodules. Polymerase chain reaction targeting the highly conserved Leporipoxvirus DNA polymerase gene was positive using DNA extracted from the cutaneous lesions of all 3 squirrels. Nucleotide sequence of the 390 base PCR amplicons was closely related to that of other members of the genus Leporipoxvirus. To the authors' knowledge, this is the first report of cutaneous and systemic poxviral disease in American red squirrels with molecular characterization of the squirrel fibroma virus.

Vascular lesions in nine Göttingen minipigs with thrombocytopenic purpura syndrome.

Tissues from 9 Göttingen minipigs, aged 7 weeks to 1 year, with clinically diagnosed thrombocytopenic purpura syndrome were examined microscopically. All pigs had a history of spontaneous cutaneous purpura that was generally accompanied by disseminated visceral hemorrhages. Hematologic abnormalities included anemia (8 out of 9 pigs) and thrombocytopenia (7 out of 9 pigs), with platelet counts consistently below 20,000/microl. Microscopically, degenerative vascular lesions with morphologic features of arteriosclerosis were present in all 9 pigs. Vascular lesions affected small- to medium-sized muscular arteries and arterioles in various organs and extraparenchymal tissues; vessels of the renal pelvis and coronary arteries were consistently involved. Microscopic lesions in small- to medium-sized muscular arteries consisted of neointimal proliferation, medial thickening, luminal stenosis, thrombosis, disruption and fragmentation of the internal elastic lamina, necrosis of the tunica media, and medial deposits of myxoid matrix material. Microscopic lesions in arterioles included concentric laminar thickening of vessel walls (onion-skin pattern), endothelial cell hypertrophy, smooth muscle cell vacuolation, necrosis of the tunica media, thrombosis, and partial to complete luminal stenosis. Arteritis and/or periarteritis were also noted in 4 out of 9 pigs. Additional microscopic lesions included membranoproliferative glomerulonephritis (3 out of 9), myocardial microinfarcts (4 out of 7), renal interstitial fibrosis (2 out of 9), extramedullary hematopoiesis (6 out of 9), and intracapillary hyaline thrombi (2 out of 9). Degenerative vascular lesions have not been previously described in Göttingen minipigs with thrombocytopenic purpura syndrome. The etiopathogenesis of both the vascular lesions and thrombocytopenic purpura syndrome is currently unknown.

Mask fear in children presenting for anesthesia: aversion, phobia, or both?

BACKGROUND: Anesthesia induction in children is commonly accomplished by introducing volatile agents by mask. Occasionally a child describes an excessive fear of the anesthesia facemask. Little is known of the cause of the fear or of the quality or magnitude of the feelings the child is experiencing. The purpose of this study was to allow children who have established mask fear as demonstrated by volunteering the presence of fear and requesting no mask be placed on the face during the induction of anesthesia and their parents to describe and compare the distress from the mask to the alternative intravenous anesthesia induction. METHODS: Eight children describing mask fear on the preanesthetic examination were studied. An Anesthesia Mask Fear questionnaire developed by the investigators was answered by the children and their parents. RESULTS: Six children and their parents completed the study. The age at presentation of mask fear ranged from 1.4 to 14 years. There were one to 16 anesthetic exposures prior to reporting mask fear. One child described an aversion to the odor of the mask. Another boy developed mask fear after a single anesthetic exposure. He was subsequently diagnosed with a generalized anxiety disorder. Four female children developed mask fear after repeated anesthetic exposures. These children rated mask fear with the greatest discomfort possible while venous cannulation was scored at half or less that of the mask discomfort. CONCLUSIONS: Care must be taken when developing a plan for anesthesia induction in children requiring multiple procedures. Children may develop an aversion to the odor or feel of the mask, or have a true phobia (irrational fear) of the mask. Those children with a phobia might also have other underlying anxieties.

Extensive lesions of monkeypox in a prairie dog (Cynomys sp).

Monkeypox with extensive lesions was diagnosed in a prairie dog that was involved in a recent human outbreak of monkeypox in the Midwestern United States. Gross lesions included oral ulcers, pulmonary consolidation, enlarged cervical and thoracic lymph nodes, and multifocal, small, white umbilicated plaques in the gastrointestinal wall. Microscopic lesions were extensive in the lungs and consisted of fibrinonecrotic bronchopneumonia with vasculitis and poorly defined eosinophilic intracytoplasmic inclusion bodies in cells thought to be alveolar epithelial cells, histiocytes, and fibroblasts. Multifocal necrotizing lesions, often accompanied by myxedema, were also present in most of the other examined organs. Aggregates of pox viral particles were observed within lesions by transmission electron microscopy. Monkeypox virus infection was confirmed by real-time polymerase chain reaction and virus culture at the Centers for Disease Control and Prevention. This report highlights the difficulties of rapid diagnosis of exotic or emerging diseases and further substantiates the prairie dog as an animal model of monkeypox.

[Three cases of postweaning multisystemic wasting syndrome (PMWS) due to porcine circovirus type 2 (PCV 2) in Switzerland]. / Drei Fälle von "Postweaning Multisystemic Wasting Syndrome" (PMWS) hervorgerufen durch das porcine Circovirus Typ 2 (PCV 2) in der Schweiz.

Porcine circovirus type 2 (PCV 2) was found in three five- and nine-week-old pigs from two feeder pig producer farms. Clinical signs were persistent diarrhea and wasting. The animals showed histomorphologic changes characteristic for "Postweaning Multisystemic Syndrome" (PMWS). One animal had the typical basophilic intracytoplasmatic circoviral inclusion bodies in the Peyer's patches of the ileum. Circoviral DNA was detected in the lymphatic organs as well as in the liver. This case report is the first description of PCV 2 in Switzerland.

Value of double-contrast barium enema performed immediately after incomplete colonoscopy.

OBJECTIVE: The purpose of this study was to evaluate the ease, completeness, and clinical utility of double-contrast barium enema (DCBE) performed immediately after incomplete colonoscopy. SUBJECTS AND METHODS: During a 30-month period, a prospective study was performed in 103 patients (79 women, 24 men) to determine the ease and completeness of DCBE immediately after failed colonoscopy and any additional useful information provided by the enema. The ease with which DCBE was performed was graded from 1 (easy) to 10 (difficult). RESULTS: DCBE revealed the entire colon in 97 patients (94%). Incomplete DCBE was a result of obstruction and incontinence in three patients each. The mean score for ease of performing DCBE was 5.0. In 14 patients (14%), significant additional diagnostic information was provided by the immediate DCBE. In eight patients, abnormalities were identified on DCBE that had not been seen at colonoscopy (five malignant neoplasms, one diverticular mass, two extrinsic masses, and multiple strictures). In four patients, a suspected colonoscopic abnormality was excluded with DCBE findings; and in two patients, a colonoscopic abnormality was further characterized with DCBE. CONCLUSION: Immediate DCBE after incomplete colonoscopy allows complete colonic evaluation in most cases, often adds vital diagnostic information, and eliminates repeated bowel preparation and unnecessary delay in diagnosis.

Tissue distribution and genetic typing of porcine circoviruses in pigs with naturally occurring congenital tremors.

Congenital tremors (CT) type A2 is associated with porcine circovirus (PCV) and deficient and abnormal myelin. The aim of this study was to determine the tissue distribution and genetic type of PCV in 1-2-day-old pigs with naturally occurring CT type A2 using in situ hybridization, polymerase chain reaction (PCR), and indirect fluorescent antibody tests on frozen tissue sections. CT-affected and clinically normal pigs were selected from 4 farms in the midwestern USA that were undergoing outbreaks of CT type A2. All CT and most normal pigs were infected with PCV. PCV was widely distributed in tissues of infected pigs and was most common in tissues of the central nervous system and liver. In all infected pigs, there were more PCV-infected cells in brain and spinal cord than in nonneural tissues. CT pigs had many more PCV-infected cells in the brain and spinal cord than did clinically normal pigs because of a more diffuse distribution and a larger proportion of infected cells. The cells most commonly infected with PCV in brain and spinal cord were large neurons. In nonneural tissues, macrophages were the most frequent cell type infected. PCR analysis demonstrated only PCV type 2 and not PCV type 1 in all PCV-infected pigs on all 4 farms.

Viral replication and lesions in BALB/c mice experimentally inoculated with porcine circovirus isolated from a pig with postweaning multisystemic wasting disease.

Eight-week-old BALB/c mice were either sham inoculated (control mice) or were inoculated intraperitoneally (IP) and intranasally (IN) with a single (sPCV mice) or multiple (mPCV mice) doses of porcine circovirus 2 (PCV2). Four control mice and 4 sPCV mice were sacrificed 7, 14, 28, and 42 days postinoculation (PI). All 4 mPCV mice were sacrificed 42 days PI. In addition, 7-day and 14-day pregnant BALB/c mice were either sham inoculated (control mice) or were inoculated IP and IN with a single dose of PCV2. Newborn mice were euthanatized 1, 8, and 15 days after birth. Necropsies were performed on all euthanatized mice and tissues were collected for histopathology, electron microscopy, in situ hybridization, and polymerase chain reaction (PCR). PCV2 replicated in 8-week-old BALB/c mice that were inoculated with PCV2 and caused fetal infection when inoculated into pregnant BALB/c mice at 7 days and 14 days of gestation. PCV was detected by in situ hybridization and PCR in sPCV mice on days 7, 14, 28, and 42 PI; in mPCV mice on day 42 PI; and in newborn mice from mothers inoculated with PCV at 7 days and 14 days of gestation at 1, 8, and 15 days after birth, but not in control mice. No clinical signs or gross lesions were found in sPCV or mPCV mice during the study. Microscopic lesions in sPCV mice and mPCV mice were characterized by expansion of germinal centers in lymphoid organs with large numbers of histiocytic cells and lymphoblasts, apoptosis of histiocytic cells in germinal centers, and mild lymphoid depletion of the paracortex. PCV nucleic acid was detected in the nuclei and cytoplasm of histiocytes and apoptotic cells in germinal centers in lymphoid tissues as well as in the nuclei of hepatocytes in the liver, in the nuclei of renal tubular epithelial cells, and in the cytoplasm of single lymphocytes in the thymus. Congenitally infected mice only had PCV nucleic acid detected in putative Kupffer cells in livers.

Morphine discriminative control is mediated by the mu opioid receptor: assessment of delta opioid substitution and antagonism.

Morphine is an effective training drug in drug discrimination procedures. In subsequent generalization tests in which other opioids are administered, mu opioid agonists selectively substitute for the training drug. Given the relative selectivity of morphine for the mu receptor, such substitution patterns suggest that the mu opioid receptor is mediating the discriminative control of this compound. The present study assessed this selective mediation by examining the ability of the delta opioid agonist SNC80 to substitute for (and the delta opioid antagonist naltrindole to antagonize) morphine stimulus effects in rats trained to discriminate morphine from its vehicle in the conditioned taste aversion baseline of drug discrimination learning. Although morphine and methadone produced dose-related substitution for morphine (10 mg/kg), there was no evidence of substitution for morphine by SNC80 at any dose tested. Further, although naloxone (3.2 mg/kg) completely blocked the discriminative effects of morphine, naltrindole (3.2-10 mg/kg) did not significantly affect the morphine stimulus. These data suggest that the discriminative control established to morphine is mediated by its activity at the mu, but not the delta, receptor.

Sedation and analgesia in adult patients: evaluation of a staged-dose system based on body weight for use in abdominal interventional radiology.

PURPOSE: To evaluate the safety and effectiveness of a systematic protocol for sedation and analgesia in interventional radiology. MATERIALS AND METHODS: Ninety-one adult patients underwent 113 abdominal interventional procedures. Fentanyl citrate and midazolam hydrochloride were administered in one to five steps (A, B, C, D, E) until the patient was drowsy and tranquil at the effective loading dose (ELD). Doses per step were as follows: A, fentanyl 1 microg per kilogram of body weight; B, midazolam 0.010-0.035 mg/kg; C, repeat dose in A; D, repeat half the dose in B; and E, midazolam 1-2-mg boluses (maximum, 0.15 mg/kg). RESULTS: The ELD was reached in no procedure after step A, in 70 after B, in 23 after C, and in 18 after D. Step E was needed in two procedures. The mean maximum pain score (scale of 0 to 10) was 3.4; pain scores in 85 (75%) procedures were 4 or less (discomforting). Severe pain occurred in seven (6%) procedures. Hypoxia (oxygen saturation < 90%) occurred in 11 (22%) procedures performed in patients breathing room air and four (6%) performed in those breathing supplemental oxygen (P: =.04). All patients responded to supplemental oxygen. CONCLUSION: This stepwise "ABCDE protocol" allows safe and effective sedation of patients. It is easy to use and may be useful in training radiology residents, staff, and nurses in the techniques of sedation and analgesia. Supplemental oxygen should be used routinely.

Low-dose nonenhanced helical CT of renal colic: assessment of ureteric stone detection and measurement of effective dose equivalent.

PURPOSE: To evaluate a low-dose, nonenhanced helical computed tomographic (CT) protocol in the detection of ureteric stones and measure the associated effective dose equivalent (H(E)) of radiation. MATERIALS AND METHODS: Sixty patients suspected of having renal colic and referred by emergency department physicians underwent nonenhanced helical CT with 7-mm collimation and a 2:1 pitch and then conventional intravenous urography (IVU). The two studies were prospectively and independently interpreted. The diagnostic accuracy of CT for ureteric stone detection was determined by comparing the scans with the IVU images and with a combination of clinical, surgical, and other imaging findings. The radiation risk from typical CT and IVU examinations (five images) was measured in terms of H(E) and compared with the estimated risk from two previously reported CT protocols. RESULTS: CT correctly depicted 36 of 37 ureteric stones, and one false-positive case was recorded, for a sensitivity of 97%, specificity of 96%, and accuracy of 97%. The H(E) for our CT protocol was determined to be 2.8 mSv, which is about double that for IVU and about 75% and 50% of that for two previously reported CT protocols. CONCLUSION: Our low-dose CT protocol is superior to IVU and clinically adequate for diagnosis of renal colic.

Ultrastructure of porcine circovirus in persistently infected PK-15 cells.

The ultrastructure of porcine circovirus was examined in persistently infected porcine kidney (PK)-15 cells. Virus-infected PK-15 cells had large numbers of intracytoplasmic inclusions, and a few cells had intranuclear inclusions. Intracytoplasmic inclusions were dispersed throughout the cytoplasm but were most numerous in the perinuclear cytoplasm. Inclusion were of various sizes, round to oval, and electron dense and were of two general types. Inclusions of the first type were small (0.1-0.5 microm diameter), not surrounded by trilaminar membranes, and granular with indistinct margins that blended with surrounding cytoplasm. Some contained 12+/-2-nm-diameter icosahedral virions in loose aggregates or rarely forming paracrystalline arrays. Small inclusions could be sites of viral assembly or maturation. Intracytoplasmic inclusions of the second type were larger (0.5-5.0 microm diameter) and more numerous and had abrupt margins surrounded by trilaminar membranes. They were more electron dense than small inclusions and were heterogeneous, containing various proportions of aggregated virions, electron-dense crystalline lamellae of 5 nm periodicity, and/or whorls of myelinoid membranes. Virions usually formed paracrystalline arrays and occasionally were loosely aggregated. Larger inclusions were typical of autophagolysosomes. Intranuclear inclusions were not membrane bound and were often associated with reticulated nucleoli or aggregates of heterochromatin. Some inclusions were irregularly shaped aggregates of indistinct, circular 10-12-nm-diameter viruslike particles. Others were 0.1-1.0 microm in diameter, round or ring shaped, dense, and finely granular, with sharply demarcated margins.

Pressure-limited ventilation of infants with low-compliance lungs: the efficacy of an adult circle system versus two free-standing intensive care unit ventilator systems using an in vitro model.

UNLABELLED: We compared the efficacy of a Drager Narkomed GS (North American Drager, Telford, PA) equipped with an adult circle system with two free-standing infant ventilator systems (Servo 300; Siemens Medical Systems, Danvers, MA and Babylog 8000; North American Drager) to deliver minute ventilation (VE) using pressure-limited ventilation to a test lung set to low compliance. To simulate a wide variety of potential patterns of ventilation, VE was measured at peak inspiratory pressures (PIP) of 20, 30, 40, and 50 cm H2O and at respiratory rates (RR) of 20, 30, 40, and 50 breaths/min. Each measurement was made three times; the average was used for data analysis using the multiple regression technique. Delivered V(E) was positively correlated with both PIP (P = 0.001) and RR (P = 0.001). Only minimal differences in VE were observed between the circle and the two free-standing systems. At lower RR and PIP, the Babylog 8000 system delivered slightly higher VE than the circle system, whereas at higher RR and PIP, the Babylog 8000 delivered slightly lower VE than the circle system; these differences in VE were not statistically significant (P = 0.45). The Servo 300 delivered slightly higher VE than the circle system in all test conditions, but these differences were not statistically significant (P = 0.09). None of the differences in delivered VE between the Servo 300 and the circle system are of clinical importance. IMPLICATIONS: Our laboratory investigation suggests that pressure-limited ventilation delivered by a standard adult circle system compares favorably with that of freestanding infant ventilators used in pressure-limited mode. Changing from an adult circle system to a free-standing pressure-limited ventilator may not substantially improve ventilation of a low-compliance infant lung; the efficacy of such a practice should be investigated.