Diagnosis and surgical treatment of a primary splenic torsion in a domestic ferret (Mustela putorius furo).

A 4-year-old female spayed domestic ferret (Mustela putorius furo) presented with a history of vomiting over 24 hours. On physical examination, a significantly enlarged, firm spleen was palpated. Abdominal radiographs and abdominal ultrasound were suggestive of a splenic torsion or splenic infarction. An exploratory laparotomy confirmed the initial diagnosis and splenectomy was performed using a vessel sealing device. Histologic evaluation and culture of the spleen were consistent with primary torsion without evidence of infection or neoplasia. The patient recovered from surgery without complications. Based on a literature search, this is the first report of the clinical diagnosis and successful surgical treatment of a primary splenic torsion in a ferret. Although it appears to be a rare and potentially life-threatening disease in ferrets, splenic torsion should be considered as a differential diagnosis in ferrets that present with non-specific signs and a palpably enlarged spleen.

Associations between biochemical parameters and referral centre in pet rabbits with urolithiasis.

OBJECTIVES: To determine the association between signalment, selected haematologic and biochemical parameters and referral centre in pet rabbits with imaging evidence of urolithiasis presented to two veterinary teaching hospitals in North America. MATERIALS AND METHODS: The medical record database of two veterinary teaching hospitals was searched from 2009 to 2019 for records of pet rabbits that received both imaging studies and plasma biochemistry profiles. Information regarding signalment, bodyweight, packed cell volume, total solids, and plasma biochemistry profiles was obtained. Univariable and multivariable logistic regression models were performed to identify statistically significant parameters associated with imaging evidence of urolithiasis. RESULTS: Of the 324 examined rabbits, 33 (10.2%) had confirmed evidence of urolithiasis on imaging. Increasing plasma calcium and sodium concentrations and referral centre were significantly associated with the presence of urolithiasis on the univariable logistic regression model. However, only plasma calcium concentration and the referral centre demonstrated significant associations on the multivariable logistic regression model. CLINICAL SIGNIFICANCE: Results indicate that urolithiasis in pet rabbits that receive imaging is associated with mildly increasing plasma calcium concentration and referral centre. The association with referral centre may indicate there are geographic influences on urolithiasis or on imaging. However, the identified associations have low predictive value for the diagnosis of urolithiasis, indicating the need for additional diagnostic modalities.

Enhanced East Pacific Rise hydrothermal activity during the last two glacial terminations.

Mid-ocean ridge magmatism is driven by seafloor spreading and decompression melting of the upper mantle. Melt production is apparently modulated by glacial-interglacial changes in sea level, raising the possibility that magmatic flux acts as a negative feedback on ice-sheet size. The timing of melt variability is poorly constrained, however, precluding a clear link between ridge magmatism and Pleistocene climate transitions. Here we present well-dated sedimentary records from the East Pacific Rise that show evidence of enhanced hydrothermal activity during the last two glacial terminations. We suggest that glacial maxima and lowering of sea level caused anomalous melting in the upper mantle and that the subsequent magmatic anomalies promoted deglaciation through the release of mantle heat and carbon at mid-ocean ridges.

Development and Impact of De Novo Anti-HLA Antibodies in Pediatric Heart Transplant Recipients.

There is increasing evidence that de novo anti-HLA antibodies, more specifically de novo donor-specific antibodies (DSA) following solid organ transplantation may be associated with negative outcomes including rejection in the first year and graft loss. Limited data are available in pediatric heart transplant recipients. We sought to prospectively determine the incidence, class and early impact of de novo anti-HLA antibodies in a cohort of pediatric heart transplant recipients. Serial panel reactive antibody testing posttransplant was performed in 25 patients (14 males) transplanted between January 2008 and June 2010. Five patients were sensitized pretransplant; all patients had negative direct crossmatch. Seventy-two percent developed de novo anti-HLA antibodies at a median of 2.6 weeks (IQR 1.2 weeks to 6.2 months) posttransplant; 67% of these were DSA. The majority of recipients in our cohort developed de novo anti-HLA antibodies within the first year posttransplant, with two-thirds being donor-specific. Acute cellular rejection, though frequent, was not different in patients with antibody development regardless of class or specificity, and there was no antibody-mediated rejection, graft loss or early cardiac allograft vasculopathy.

PKR downregulation prevents neurodegeneration and ß-amyloid production in a thiamine-deficient model.

Brain thiamine homeostasis has an important role in energy metabolism and displays reduced activity in Alzheimer's disease (AD). Thiamine deficiency (TD) induces regionally specific neuronal death in the animal and human brains associated with a mild chronic impairment of oxidative metabolism. These features make the TD model amenable to investigate the cellular mechanisms of neurodegeneration. Once activated by various cellular stresses, including oxidative stress, PKR acts as a pro-apoptotic kinase and negatively controls the protein translation leading to an increase of BACE1 translation. In this study, we used a mouse TD model to assess the involvement of PKR in neuronal death and the molecular mechanisms of AD. Our results showed that the TD model activates the PKR-eIF2α pathway, increases the BACE1 expression levels of Aß in specific thalamus nuclei and induces motor deficits and neurodegeneration. These effects are reversed by PKR downregulation (using a specific inhibitor or in PKR knockout mice).

Development of donor-specific isohemagglutinins following pediatric ABO-incompatible heart transplantation.

Graft acceptance following pediatric ABO-incompatible heart transplantation has been associated with a deficiency of donor-specific isohemagglutinins (DSI) due to B-cell elimination. Recent observations suggest that some of these patients do produce DSI. The purpose of this study was to examine the pattern of, risk factors for development and clinical impact of DSI. All children who underwent an ABO-incompatible heart transplant (1996-2009) were included. Serial postheart transplantation DSI titers and clinical outcomes were reviewed. DSI were produced in 27% of the patients (n = 11/41). Anti-A production was significantly greater in "at risk" patients than Anti-B (39% vs. 8%; p = 0.04). Risk factors associated with the development of DSI included: older age at transplantation (HR: 1.15/month, p = 0.04), pretransplant Anti-B level ≥ 1:8 (HR: 9.61, p = 0.004) and HLA sensitization (HR: 2.80, p = 0.11). The presence of DSI did increase the risk of cellular rejection but not antibody-mediated rejection, allograft vasculopathy, graft loss or death. Although these antibodies do not result in any significant clinical consequences, their presence suggests that B-cell tolerance is not the sole mechanism of graft acceptance.

Targeting the FANCJ-BRCA1 interaction promotes a switch from recombination to poleta-dependent bypass.

BRCA1 and the DNA helicase FANCJ (also known as BACH1 or BRIP1) have common functions in breast cancer suppression and DNA repair. However, the functional significance of the direct interaction between BRCA1 and FANCJ remains unclear. Here, we have discovered that BRCA1 binding to FANCJ regulates DNA damage repair choice. Thus, when FANCJ binding to BRCA1 is ablated, the molecular mechanism chosen for the repair of damaged DNA is dramatically altered. Specifically, a FANCJ protein that cannot be phosphorylated at serine 990 or bind BRCA1 inhibits DNA repair via homologous recombination and promotes poleta-dependent bypass. Furthermore, the poleta-dependent bypass promoted by FANCJ requires the direct binding to the mismatch repair (MMR) protein, MLH1. Together, our findings implicate that in human cells BRCA1 binding to FANCJ is critical to regulate DNA repair choice and promote genomic stability. Moreover, unregulated FANCJ function could be associated with cancer and/or chemoresistance.

An improved medical admissions risk system using multivariable fractional polynomial logistic regression modelling.

AIM: To develop and validate an in-hospital mortality risk prediction tool for unselected acutely ill medical patients using routinely collected physiological and laboratory data. DESIGN: Analysis of all emergency medical patients admitted to St James's Hospital (SJH), Dublin, between 1 January 2002 and 31 December 2007. Validation using a dataset of acute medical admissions from Nenagh Hospital 2000-04. METHODS: Using routinely collected vital signs and laboratory findings, a composite 5-day in-hospital mortality risk score, designated medical admissions risk system (MARS), was developed using an iterative approach involving logistic regression and multivariable fractional polynomials. Results are presented as area under receiver operating characteristics curves (AUROC) as well as Hosmer and Lemeshow goodness-of-fit statistics. RESULTS: A total of 10 712 and 3597 unique patients were admitted to SJH and Nenagh Hospital, respectively. The final score included nine variables [age, heart rate, mean arterial pressure, respiratory rate, temperature, urea, potassium (K), haematocrit and white cell count]. The AUROC for 5-day in-hospital mortality was 0.93 [95% confidence interval (CI) 0.92-0.94] for the SJH cohort (Hosmer and Lemeshow test, P = 0.32) and 0.92 (95% CI 0.90-0.94) for the external Nenagh hospital validation cohort (Hosmer and Lemeshow test, P = 0.28). CONCLUSION: In-hospital mortality estimation using only routinely collected emergency department admission data is possible in unselected acute medical patients using the MARS system. Such a score applied to acute medical patients at the time of admission, could assist senior clinical decision makers in promptly and accurately focusing limited clinical resources. Further studies validating the impact of this model on clinical outcomes are warranted.

Impact of an acute medical admission unit on hospital mortality: a 5-year prospective study.

AIM: To determine the impact of the introduction of an acute medical admission unit (AMAU) on all-cause hospital mortality in unselected patients undergoing acute medical admission to a teaching hospital. DESIGN: Analysis of data recorded in the hospital in-patient enquiry (HIPE) system relating to all emergency medical patients admitted to St James's Hospital (SJH), Dublin between 1 January 2002 and 31 December 2006. METHODS: The reference year was 2002, during which patients were admitted to a variety of wards under the care of a named consultant physician. In 2003, two centrally located wards were re-configured to function as an AMAU, and all emergency medical patients were admitted to this unit following emergency department evaluation. Hospital mortality was obtained from a database of deaths occurring during this period and linked to HIPE data. RESULTS: Following the introduction of the AMAU process, all-cause hospital mortality decreased from 12.6% in 2002 to 7.0% in 2006 (P < 0.0001), representing a 44.4% relative reduction during the course of the 5-year observation period (P < 0.0001). The Odds ratio (95% confidence interval) for all-cause mortality in 2006 compared with 2002 was 0.28 (0.23, 0.35). This effect was powerfully independent of other covariates, including Charlson co-morbidity and illness severity score (APACHE II), in binary logistic regression analysis and was observed across a wide cross-section of diagnostic groups. CONCLUSION: The introduction of an AMAU significantly improved all-cause hospital mortality in acute unselected medical patients. The delivery of Acute Medicine may be enhanced by structural reform with emphasis on focus and volume. Prospective studies validating similar models elsewhere should be explored.

Synovial tissue interleukin-18 expression and the response to treatment in patients with inflammatory arthritis.

OBJECTIVE: To measure synovial tissue interleukin-18 (IL-18) expression in patients with inflammatory arthritis, and to identify associations with serum levels, disease activity, and response to treatment. METHODS: Synovial tissue biopsies and serum samples were obtained from patients with early, active, rheumatoid arthritis (RA) (n = 12), undifferentiated seronegative arthritis (SnA) (n = 9), psoriatic arthritis (PsA) (n = 5), and reactive arthritis (ReA) (n = 2) before and one year after introduction of disease modifying antirheumatic drug (DMARD) treatment. Osteoarthritis (OA) tissues were compared. Tissue IL-18 expression was determined after immunohistochemical staining using a semiquantitative scale. Serum IL-18 was measured by enzyme linked immunosorbent assay. RESULTS: Before treatment was started, tissue IL-18 expression was increased in each diagnostic group compared with OA (p<0.05). Tissue IL-18 expression was correlated with serum C reactive protein levels (r = 0.53, p = 0.003) but not with serum IL-18. After DMARD treatment, 12 patients (five RA, four SnA, three PsA) were re-evaluated. Decreases in tissue IL-18 expression were observed in eight, although the trend did not reach significance (p = 0.068). Changes in tissue IL-18 expression were correlated with changes in serum IL-18 (r = 0.62, p = 0.041) and C reactive protein (r = 0.72, p = 0.009). CONCLUSIONS: Synovial tissue IL-18 expression was correlated with disease activity in inflammatory arthritis. After treatment, tissue levels changed in parallel with changes in serum IL-18 and with changes in the acute phase response. These observations support a role for IL-18 in the pathophysiology of inflammatory arthritis.

A Naval Academy midshipman with ehrlichiosis after summer field exercises in Quantico, Virginia.

A case of human ehrlichiosis (caused by infection with Ehrlichia chaffeensis) is presented. The patient was a female Naval Academy midshipman with a 26-day history of daily field training with the U.S. Marines near Quantico, Virginia. She presented with a several-day history of myalgias, fever, and frontal headache. During her clinical course, she developed fever to 104 degrees F, dry cough, dyspnea on exertion, arthralgias, and nephrotic syndrome. She did not develop a rash. Laboratory studies were significant for thrombocytopenia, equivocal Lyme enzyme immunosorbent assay with a negative confirmatory western immunoblot, equivocal Rocky Mountain spotted fever acute serology without a convalescent increase in immunoglobulin G, and immunoglobulin G/immunoglobulin M serology positive for human monocytic ehrlichiosis. She manifested known sequelae for this emerging disease, including dyspnea, pedal edema, increased transminases, and nephrotic syndrome.

Two cases of nonconvulsive status epilepticus in association with tiagabine therapy.

We report two patients with intractable partial seizures who developed generalized nonconvulsive status epilepticus (NCSE) after receiving tiagabine (TGB). Neither had a history of absence seizures or generalized epileptic discharges on prior EEG monitoring. Clinicians need to be aware of a possible association between TGB and NCSE.

Dose-loading with hydroxychloroquine improves the rate of response in early, active rheumatoid arthritis: a randomized, double-blind six-week trial with eighteen-week extension.

OBJECTIVE: To investigate the usefulness of hydroxychloroquine (HCQ) dose-loading to increase the percentage of responders or rate of response in treating rheumatoid arthritis (RA). METHODS: Two hundred twelve patients with early RA (mean duration 1.5 years) were enrolled in a 24-week trial. Patients were stabilized with 1,000 mg naproxen/day and then began a 6-week, double-blind trial comparing treatment with HCQ at 400 mg/day (n = 71), 800 mg/day (n = 71), and 1,200 mg/day (n = 66), followed by 18 weeks of open-label HCQ treatment at 400 mg/day. RESULTS: All patients had mild, active disease at the time of initiation of HCQ treatment (31-43% rheumatoid factor positive; no previous disease-modifying antirheumatic drugs; mean swollen joint count 8.6-10.4). Based on the Paulus criteria, response during the 6-week double-blind portion of the study was 47.97%, 57.7%, and 63.6% in the 400 mg/day, 800 mg/day, and 1,200 mg/day groups, respectively (P = 0.052). Discontinuations for adverse events were dose related (3 in the 400 mg/day group, 5 in the 800 mg/day group, 6 in the 1,200 mg/day group). Most involved the gastrointestinal (GI) system, with the background naproxen treatment possibly contributing. Ocular abnormalities occurred in 17 of 212 patients (8%) but were not dose related. CONCLUSION: Dose-loading with HCQ increased the degree of response at 6 weeks in this group of patients with early, predominantly seronegative RA. Adverse GI events were dose related, while adverse ocular events were not.

N-Methyl-D-aspartate inhibits apoptosis through activation of phosphatidylinositol 3-kinase in cerebellar granule neurons. A role for insulin receptor substrate-1 in the neurotrophic action of n-methyl-D-aspartate and its inhibition by ethanol.

Primary cultured rat cerebellar granule neurons underwent apoptosis when switched from medium containing 25 mM K+ to one containing 5 mM K+. N-methyl-D-aspartate (NMDA) protected granule neurons from apoptosis in medium containing 5 mM K+. Inhibition of apoptosis by NMDA was blocked by the phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor LY294002, but it was unaffected by the mitogen-activated protein kinase kinase inhibitor PD 98059. The antiapoptotic action of NMDA was associated with an increase in the tyrosine phosphorylation of insulin receptor substrate 1 (IRS-1), an increase in the binding of the regulatory subunit of PI 3-kinase to IRS-1, and a stimulation of PI 3-kinase activity. In the absence of extracellular Ca2+, NMDA was unable to prevent apoptosis or to phosphorylate IRS-1 and activate PI 3-kinase. Significant inhibition of NMDA-mediated neuronal survival by ethanol (10-15%) was observed at 1 mM, and inhibition was half-maximal at 45-50 mM. Inhibition of neuronal survival by ethanol corresponded with a marked reduction in the capacity of NMDA to increase the concentration of intracellular Ca2+, phosphorylate IRS-1, and activate PI 3-kinase. These data demonstrate that the neurotrophic action of NMDA and its inhibition by ethanol are mediated by alterations in the activity of a PI 3-kinase-dependent antiapoptotic signaling pathway.

Ethanol induces apoptosis in cerebellar granule neurons by inhibiting insulin-like growth factor 1 signaling.

The ability of ethanol to interfere with insulin-like growth factor 1 (IGF-1)-mediated cell survival was examined in primary cultured cerebellar granule neurons. Cells underwent apoptosis when switched from medium containing 25 mM K+ to one containing 5 mM K+. IGF-1 protected granule neurons from apoptosis in medium containing 5 mM K+. Ethanol inhibited IGF-1-mediated neuronal survival but did not inhibit IGF-1 receptor binding or the neurotrophic action of elevated K+, and failed to potentiate cell death in the presence of 5 mM K+. Inhibition of neuronal survival by ethanol was not reversed by increasing the concentration of IGF-1. Significant inhibition by ethanol (15-20%) was observed at 1 mM and was half-maximal at 45 mM. The inhibition of IGF-1 protection by ethanol corresponded to a marked reduction in the phosphorylation of insulin receptor substrate 1, the binding of phosphatidylinositol 3-kinase (PI 3-kinase), and a block of IGF-1-stimulated PI 3-kinase activity. The neurotrophic response of IGF-1 was also inhibited by the PI 3-kinase inhibitor LY294002, the protein kinase C inhibitor chelerythrine chloride, and the protein kinase A inhibitor KT5720, but unaffected by the mitogen-activated protein kinase kinase inhibitor PD 98059. These data demonstrate that ethanol promotes cell death in cerebellar granule neurons by inhibiting the antiapoptotic action of IGF-1.

Cyclic GMP induces oscillatory calcium signals in rat hepatocytes.

The ability of guanosine-3',5'-cyclic monophosphate (cGMP) to induce increases in the intracellular free calcium ion concentration ([Ca2+]i) was studied at the single cell level in fura-2-loaded rat hepatocytes. Both 8-bromo-cGMP (Br-cGMP) and dibutyryl cGMP (db-cGMP) produced oscillatory [Ca2+]i increases in hepatocytes. In addition, Br-cGMP increased the frequency of agonist-induced spiking or converted [Ca2+]i oscillations into sustained nonoscillatory [Ca2+]i responses. Addition of the nitric oxide donor sodium nitroprusside also produced oscillatory [Ca2+]i increases similar to those generated by cGMP analogues. In the absence of extracellular Ca2+, cGMP-induced [Ca2+]i responses were significantly reduced and mainly appeared as single transient [Ca2+]i increases. The effects of cGMP analogues do not appear to be mediated by a secondary increase in cAMP or activation of cAMP-dependent protein kinase (PKA), since [Ca2+]i responses to cGMP analogues were inhibited by the G-kinase inhibitor 8-bromoguanosine-3',5'-cyclic monophosphorothioate (Rp-Br-cGMP[S]). Both Br-cGMP and db-cGMP also increased [Ca2+]i in the presence of the PKA inhibitor 8-bromoadenosine-3',5'-cyclic monophosphorothioate (Rp-Br-cAMP[S]) and when the cGMP-inhibitable cAMP phosphodiesterase activity was inhibited by pretreatment with siguazodan. Br-cGMP stimulated the Mn2+-induced quench of compartmentalized fura-2 in intact hepatocytes, indicating a site of action at the level of the Ca2+ stores. This locus was further supported by the finding that pretreatment of hepatocytes with Br-cGMP potentiated submaximal inositol 1,4,5-trisphosphate (InsP3)-induced Mn2+ quench in subsequently permeabilized hepatocytes. db-cGMP also decreased PKA-mediated back phosphorylation of the hepatic type-1 InsP3 receptor, indicating that G-kinase phosphorylates the InsP3 receptor at sites targeted by PKA. These data indicate that phosphorylation of the hepatic InsP3 receptor by G-kinase increases the sensitivity to InsP3 for [Ca2+]i release and is associated with the production of [Ca2+]i oscillations in single rat hepatocytes.

Effects of metyrapone on expression of CYPs 2C11, 3A2, and other 3A genes in rat hepatocytes cultured on matrigel.

Hepatocytes cultured on matrigel express many liver-specific functions, but the levels and activities of the predominant male-specific rat hepatic CYPs, 3A2 and 2C11, decline rapidly in culture. Metyrapone maintains the level of total cytochrome P450 of rat hepatocytes in primary culture, but the mechanism underlying this effect has not been completely elucidated. The present study sought to determine whether metyrapone acts solely to stabilise CYP proteins in rat hepatocytes cultured on matrigel, or whether it also influences mRNA levels of the encoding genes. Metyrapone maintained the level of total cytochrome P450 in cultured hepatocytes so that values were > 200% of those found in untreated control cells 24 hr after isolation. At this time, CYP3A2-mediated testosterone 6 beta-hydroxylation was approximately 7-fold higher in hepatocytes cultured in the presence of metyrapone than in control cells, and CYP2C11-dependent testosterone 2 alpha- and 16 alpha-hydroxylation activities were between 2 and 3-fold greater. The results inferred from catalytic activities were supported by immunoquantitation of CYP3A and 2C11 proteins. The trend of increased CYP protein levels in metyrapone-treated cells continued throughout the 48-hr culture period. In control cells, CYP3A2 and 2C11 mRNA levels fell abruptly in culture to reach values at 24 hr that were < 30% of those in freshly isolated cells; addition of metyrapone failed to arrest this fall. However, treatment of cells with metyrapone considerably elevated levels of one or more CYP3A subfamily mRNA species, as detected by a riboprobe based on the cDNA for CYP3A1 ("CYP3A1-like mRNA') that were demonstrated, by another riboprobe, not to be CYP3A2 or RNCYP3AM. RT-PCR of mRNA prepared from cultured hepatocytes, followed by restriction mapping of the cloned cDNAs was used to characterise the CYP3A induced by metyrapone. This revealed that elevated levels of the CYP3A1-like mRNA were attributable to induction of RL33/cDEX mRNA; there were no CYP3A1 cDNAs isolated from these cells. These data are interpreted as indicating that metyrapone stabilises the expression of cytochrome P450 in culture by both pre- and posttranslational mechanisms. The particular mechanism employed is gene-specific, whereby even the highly homologous genes CYP3A2, RL33/cDEX and, possibly, RNCYP3AM are subject to different types of regulation in the presence of metyrapone.