The diagnostic utility of hypophosphatemia for differentiating generalized tonic-clonic seizures from syncope in dogs: A case control study.

Transient hypophosphatemia is often detected in humans following generalized tonic-clonic seizures (GTCS), and serum phosphorus concentration (sPi) serves as a marker to differentiate GTCS from syncope. The objective of this retrospective study was to assess the usefulness of hypophosphatemia as a diagnostic marker for GTCS in dogs. Eighty-seven and 26 client-owned dogs with GTCS or syncope, respectively, were enrolled. Dogs were included if the episode occurred ≤ 3 h from presentation, and if sPi and serum creatinine (sCr) were measured. Dogs were excluded if aged < 1 year or if sCr exceeded 176.8 µmol/L. There were no group differences in sCr. Hypophosphatemia (sPi ≤ 0.97 mmol/L) occurred in 28 dogs (32%) in the seizure group, and in no dogs in the syncope group. Median sPi was significantly (P < 0.001) lower in the seizure group (1 mmol/L, [range, 0.31-2.87 mmol/L]) compared to the syncope group (1.35 mmol/L [range, 0.97-2.71 mmol/L]). Furthermore, in dogs presented while seizing (n = 24/87; 28%) median sPi was significantly lower compared to those that were not (0.9 mmol/L [range, 0.3-1.74 mmol/L] vs. 1 mmol/L [range, 0.33-2.18 mmol/L], P = 0.050). ROC analysis of sPi as a marker of GTCS yielded an AUC of 0.757 (95% confidence interval 0.667-0.847), with an optimum cutoff point of 0.97 mmol/L, corresponding to specificity and sensitivity levels of 100% and 44%, respectively. In conclusion, sPi may, in certain cases, serve as an additional diagnostic tool to differentiate GTCS from syncope in dogs. Hypophosphatemia, especially with sPi < 0.97 mmol/L, may be useful in clinical practice to rule in GTCS.

Prevalence, clinical manifestations, laboratory findings, treatment, and outcome of intermediate syndrome in anticholinesterase pesticide intoxication of dogs: A retrospective study.

Organophosphates and carbamates are important anticholinesterase intoxicants of humans and dogs. Intermediate syndrome (IMS) typically occurs 7-96 h following a toxicity-associated acute cholinergic crisis (ACC), and manifests clinically as weakness of the proximal limb, respiratory, and neck flexor muscles. The aim of this study was to describe the prevalence, clinical findings, and outcome of IMS in dogs. The medical records of a veterinary teaching hospital were searched for dogs diagnosed with ACC, IMS, or both, between 2017 and 2021. Case files were retrospectively reviewed. Six historical IMS cases were additionally reviewed. Thirty-two dogs were diagnosed with anticholinesterase intoxication during the search period, of which 23 (72 %) were only diagnosed with ACC, seven (22 %) progressed from ACC to IMS, and two (6 %) were only diagnosed with IMS. Duration of hospitalisation was longer in the IMS group compared to the ACC only group (P = 0.005). When all dogs with IMS (n = 15, including the six historical cases) were considered, survival was 100 %, including four (27 %) that required positive pressure mechanical ventilation following respiratory failure. Serum butyrylcholine esterase activity, a marker of cholinesterase activity, was below reference interval when first measured in 14 (93 %) of dogs; however, was not a useful as a recovery marker. IMS should be suspected in dogs demonstrating respiratory, neck, and proximal limb muscle paresis or paralysis, especially following clinical signs consistent with ACC. Absence of clinical signs consistent with ACC or butyrylcholine esterase activity within the reference interval does not exclude IMS as a differential.

MSX1 Drives Tooth Morphogenesis Through Controlling Wnt Signaling Activity.

Tooth agenesis is a common structural birth defect in humans that results from failure of morphogenesis during early tooth development. The homeobox transcription factor Msx1 and the canonical Wnt signaling pathway are essential for "bud to cap" morphogenesis and are causal factors for tooth agenesis. Our recent study suggested that Msx1 regulates Wnt signaling during early tooth development by suppressing the expression of Dkk2 and Sfrp2 in the tooth bud mesenchyme, and it demonstrated partial rescue of Msx1-deficient molar teeth by a combination of DKK inhibition and genetic inactivation of SFRPs. In this study, we found that Sostdc1/Wise, another secreted Wnt antagonist, is involved in regulating the odontogenic pathway downstream of Msx1. Whereas Sostdc1 expression in the developing tooth germ was not increased in Msx1-/- embryos, genetic inactivation of Sostdc1 rescued maxillary molar, but not mandibular molar, morphogenesis in Msx1-/- mice with full penetrance. Since the Msx1-/-;Sostdc1-/- embryos exhibited ectopic Dkk2 expression in the developing dental mesenchyme, similar to Msx1-/- embryos, we generated and analyzed tooth development in Msx1-/-;Dkk2-/- double and Msx1-/-;Dkk2-/-;Sostdc1-/- triple mutant mice. The Msx1-/-;Dkk2-/- double mutants showed rescued maxillary molar morphogenesis at high penetrance, with a small percentage also exhibiting mandibular molars that transitioned to the cap stage. Furthermore, tooth development was rescued in the maxillary and mandibular molars, with full penetrance, in the Msx1-/-;Dkk2-/-;Sostdc1-/- mice. Together, these data reveal 1) that a key role of Msx1 in driving tooth development through the bud-to-cap transition is to control the expression of Dkk2 and 2) that modulation of Wnt signaling activity by Dkk2 and Sostdc1 plays a crucial role in the Msx1-dependent odontogenic pathway during early tooth morphogenesis.

The prognostic value of the Koret CT score in dogs following traumatic brain injury.

Traumatic brain injury (TBI) is a common condition in veterinary medicine with relatively high mortality rate. Recently, a study that correlated abnormal computed tomography (CT) findings with outcome in dogs with head trauma established a prognostic scoring system termed Koret CT score (KCTS). The purpose of this study was to evaluate the accuracy of the KCTS in making short- and long-term prognosis in dogs presented within 72 h of TBI. Thirty-five dogs that were admitted to a hospital during 2010-2019 with TBI and were CT-scanned within 72 h of injury were included in the study. Retrospectively collected data included signalment, modified Glasgow Coma Scale score (MGCS), CT findings, and outcome, i.e. short-term (defined as 10 days) and long-term (6 months) survival. CT images were reviewed and the KCTS was calculated for all dogs. Association between KCTS and outcome was examined. A significant negative association was found between KCTS and both short- and long-term survival. The area under receiver operating characteristic curve for KCTS for short- and long-term survival was 0.9 and 0.87, respectively. Furthermore, the probability of survival in the short term was predicated by the KCTS in an almost linear fashion and a score of 3 points or less on the KCTS was associated with survival with 85% sensitivity and 100% specificity. These results validate the prognostic value of the KCTS in dogs with TBI and provide a complementary tool for serial clinical and neurological evaluation.

Serum Concentrations of Neuron-Specific Enolase in Dogs Following Traumatic Brain Injury.

The ability to make an accurate prognosis, which is a prerequisite for treatment decisions, is very limited in dogs with traumatic brain injury (TBI). To determine whether serum concentrations of neuron-specific enolase (NSE) have prognostic value in dogs following TBI, we conducted a prospective, observational, controlled clinical study in an intensive care unit of a university teaching hospital. The study population comprised 24 dogs admitted to the hospital within 72 h of a known event of TBI between January 2010 and January 2015, as well as 25 control healthy shelter dogs admitted for elective neutering. Seventeen injured dogs (70%) survived to discharge, four were euthanized and three died within 48 h. Serum samples were obtained from all dogs (in injured dogs, within 72 h of TBI) and NSE concentrations were measured using enzyme-linked immonosorbent assay. Associations between NSE levels and outcome, Modified Glasgow Coma Scale, time to sampling, age or haemolysis scale were determined. Mean serum NSE concentrations were decreased in dogs with TBI compared with healthy controls (19.4 ± 4.14 ng/ml vs. 24.9 ± 4.6 ng/ml, P <0.001). No association was found between serum NSE concentrations and either survival or severity of neurological impairment. A negative correlation was found between serum NSE concentrations and time from trauma to blood collection (r = -0.50, P = 0.022). These results indicate that serum NSE concentration in dogs following TBI is not an effective marker for severity or outcome. Further studies are warranted to standardize serum NSE measurements in dogs and to determine the peak and half-life levels of this potential biomarker.

Clinical manifestations, laboratory findings, treatment and outcome of acute organophosphate or carbamate intoxication in 102 dogs: A retrospective study.

Organophosphates (OP) and carbamates are commonly used insecticides and important intoxication sources of humans and animals. Nevertheless, large scale studies of these intoxications in dogs are unavailable. The medical records of dogs presented to a veterinary hospital were reviewed retrospectively. The study included 102 dogs definitely diagnosed with acute OP or carbamate intoxication. The most common presenting clinical signs included muscle tremor, hypersalivation, miosis, weakness, vomiting and diarrhea. Hypersalivation, muscle tremor and tachypnea were significantly (P < 0.05) associated with survival to discharge; while weakness, mental dullness, anorexia, pale mucous membranes and paddling were significantly associated with death. Common laboratory abnormalities included decreased butyrylcholine esterase activity, acidemia, increased total plasma protein, leukocytosis, hypochloridemia, hyperbilirubinemia, increased creatinine and alanine transaminase (ALT), aspartate transaminase (AST) and creatine kinase activities, and prolonged activated partial thromboplastin time (aPTT). Compared to the survivors, the non-survivors showed significantly: higher frequencies of thrombocytopenia, hypocarbemia, prolonged prothrombin time (PT), hypernatremia, hyperkalemia, hypocholesterolemia, hypoproteinemia, hypertriglyceridemia, increased ALT activity and increased urea concentration; lower median concentrations of venous blood bicarbonate, serum chloride and total CO2; and higher medians of PT, serum total bilirubin and urea concentrations, and ALT and AST activities. Intoxicated dogs were commonly treated with diphenhydramine, atropine-sulfate, antibiotics, diazepam and pralidoxime, while some (19.2%) required general anesthesia and mechanical ventilation. The survival rate of dogs treated by gastric lavage was higher (P = 0.041) compared to that of the remaining dogs. Development of respiratory failure and mechanical ventilation requirement were significantly associated (P < 0.001) with death. The mortality rate was 17%.

Detection of Intraspinal Spirocerca lupi in Canine Cerebrospinal Fluid by Polymerase Chain Reaction.

Aberrant migration of Spirocerca lupi into the spinal cord is an important cause of severe progressive neurological dysfunction in dogs. Although early diagnosis is essential to prevent deterioration, ante-mortem diagnosis of this condition remains challenging. The aim of this study was to evaluate the detection of the 18S ribosomal DNA (rDNA) S. lupi gene in the cerebrospinal fluid (CSF) of presumptively-affected dogs using polymerase chain reaction (PCR). Dogs with a non-compressive spinal cord lesion, pleocytosis with presence of eosinophils in the CSF and a characteristic clinical presentation were included. CSF samples from eight dogs were available for the study, of which seven were definitively diagnosed with intraspinal spirocercosis by PCR of either the CSF samples (6/7) or tissue samples obtained at necropsy examination (3/7), or both (2/7). Of these seven positive cases, only one dog had a negative CSF PCR, indicating a sensitivity of 86% for detecting nematode DNA in the CSF of infected dogs using this PCR protocol. The nematode DNA sequences obtained from the CSF of six dogs and the spinal cord tissue of three dogs were 98-100% identical to the publicly available sequences of S. lupi, confirming the diagnosis. These findings indicate that PCR targeting the 18S rDNA of S. lupi in CSF is useful for the ante-mortem diagnosis of canine intraspinal spirocercosis.

Observations of foetal heart veins draining directly into the left and right atria.

Evaluation of semiserial sections of 14 normal hearts from human foetuses of gestational age 25-33 weeks showed that all of these hearts contained thin veins draining directly into the atria (maximum, 10 veins per heart). Of the 75 veins in these 14 hearts, 55 emptied into the right atrium and 20 into the left atrium. These veins were not accompanied by nerves, in contrast to tributaries of the great cardiac vein, and were negative for both smooth muscle actin (SMA) and CD34. However, the epithelium and venous wall of the anterior cardiac vein, the thickest of the direct draining veins, were strongly positive for SMA and CD34, respectively. In general, developing fibres in the vascular wall were positive for CD34, while the endothelium of the arteries and veins was strongly positive for the present DAKO antibody of SMA. The small cardiac vein, a thin but permanent tributary of the terminal portion of the great cardiac vein, was also positive for SMA and CD34. A few S100 protein-positive nerves were observed along both the anterior and small cardiac veins, but no nerves accompanied the direct dra- inage veins. These findings suggested that the latter did not develop from the early epicardiac vascular plexus but from a gulfing of the intratrabecular space or sinus of the atria. However, the immunoreactivity of the anterior cardiac vein suggests that it originated from the vascular plexus, similar to tributaries of the great cardiac vein.

The prognostic value of cerebrospinal fluid characteristics in dogs without deep pain perception due to thoracolumbar disc herniation.

Providing a pre-operative prognosis for dogs presented with absent deep pain perception (DPP) is extremely challenging, as the overall recovery rates widely vary. This study assesses the possible correlation between the severity of spinal cord injury and CSF cytology in 31 paraplegic dogs presented with absent DPP due to acute thoracolumbar intervertebral disc herniation (TL-IVDH). All dogs underwent surgical decompression immediately following diagnosis. CSF TNCC, macrophage percentage and macrophage to monocyte (MΦ:M) ratio were significantly higher in dogs that failed to regain DPP within 10 days post-operatively and in dogs that failed to regain ambulation at the end of the study period (P< 0.05). MΦ:M of 0.73 and higher corresponded to a sensitivity of 54% and specificity of 100% for prediction of a negative long-term outcome. CSF TNCC, macrophage percentage and MΦ:M ratio effectively predicted regaining DPP and the long-term outcome in dogs that lost DPP due to acute TL-IVDH.

Tumor necrosis factor-α and interleukin-6 concentrations in cerebrospinal fluid of dogs after seizures.

BACKGROUND: Idiopathic and acquired epilepsy are common in dogs. Up to 30% of these dogs are refractory to pharmacological treatment. Accumulating experimental evidence indicates that brain immune response and presence of inflammatory mediators decrease the threshold for individual seizures and contribute to epileptogenesis. HYPOTHESIS: Dogs with seizures have higher cerebrospinal interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) concentrations compared to dogs with no seizures. METHODS: A prospective double blinded study; cerebrospinal fluid (CSF) and serum IL-6, TNF-α and total protein (TP) concentrations were measured by a blinded investigator for the study group and CSF IL-6 and TNF-α levels and TP concentrations were measured in the control group (CG). ANIMALS: Dogs presented with seizures that had enough CSF collected to allow analysis were included in the study group. Twelve apparently healthy, quarantined, stray dogs served as control (CG). RESULTS: Cerebrospinal fluid TNF-α and IL-6 concentrations were significantly higher (P = .011, P = .039) in dogs with seizures (0 ± 70.66, 0.65 ± 10.93 pg/mL) compared to the CG (0 ± 19, 0.73 ± 0.55 pg/mL). When assessing cytokine concentrations of specifically the idiopathic epilepsy (IE) dogs compared to the CG, only TNF-α concentrations (8.66 ± 62, 0 ± 19 pg/mL) were significantly higher (P = .01). CSF TP concentrations were not significantly higher in the study dogs compared to the CG. CONCLUSIONS AND CLINICAL IMPORTANCE: Higher TNF-α and IL-6 concentration in the CSF of dogs with naturally occurring seizures. The higher supports the hypothesis that inflammatory processes through certain mediators play a role in the pathogenesis of seizures in dogs.

Association of cerebrospinal fluid analysis findings with clinical signs and outcome in acute nonambulatory thoracolumbar disc disease in dogs.

BACKGROUND: Cerebrospinal fluid (CSF) pleocytosis recently was associated with the severity of neurologic signs in dogs with intervertebral disc disease (IVDD). HYPOTHESIS/OBJECTIVES: To look for an association among CSF cell counts, total protein concentration, and severity of neurologic signs at presentation with outcome in dogs with acute thoracolumbar IVDD. Our hypothesis was that CSF total nucleated cell count (TNCC) and percentage cell types would be associated with the severity of spinal cord damage and therefore with both the presenting clinical signs and the prognosis of affected dogs. ANIMALS: Fifty-four dogs with acute nonambulatory thoracolumbar IVDD were evaluated. METHODS: Retrospective study. Signalment, neurologic grade, CSF TNCC, protein concentration, red blood cells count and differential cell percentages, and short- and long-term outcomes were evaluated. RESULTS: CSF pleocytosis (>5 cells/µL) was present in 54% of dogs and was positively associated with neurologic grade at presentation and with postoperative time to regaining ambulation. Neutrophils were observed most frequently. The percentage of CSF macrophages and macrophage to monocyte ratio were higher (P = .001, for both) in dogs presented without deep pain sensation (DPS) that did not regain ambulation. Receiver operator characteristics curve analysis yielded a cut-off point of 13% macrophages with a sensitivity and specificity of 100 and 83%, respectively, for prediction of a negative outcome. CONCLUSIONS AND CLINICAL IMPORTANCE: CSF pleocytosis is positively associated with the severity of spinal cord damage in dogs with thoracolumbar IVDD. The percentage of CSF macrophages can be used as a prognostic indicator for regaining ambulation in dogs that have lost DPS.

Successful medical management of lumbar intervertebral disc prolapse in a ferret.

Thoracolumbar disc herniation was diagnosed in a two-year-old ferret using a myelogram followed by a computed tomography scan. The ferret was paraplegic with no control over urination and defecation. Conservative treatment that included cage rest and passive range of motion exercises for three weeks followed by extensive physiotherapy and hydrotherapy resulted in full recovery two months after the onset of treatment. Although intervertebral disc disease has been reported previously in four ferrets, this is the first report in which a postmyelogram computed tomography was used to demonstrate the herniated disc, and physiotherapy was used as principal treatment modality.

Histamine release induced by dendroaspis natriuretic peptide from rat mast cells.

Dendroaspis natriuretic peptide (DNP), recently isolated from the venom of the green Mamba snake Dendroaspis angusticeps, is a 38 amino acid peptide containing a 17 amino acid disulfide ring structure similar to that of the natriuretic peptide family. The natriuretic peptide family is known to induce histamine release from human and rat mast cells, but there are no published data concerning the effects of DNP on histamine release from mast cells. The purpose of this study is to investigate whether DNP induces the histamine release from rat peritoneal mast cells (RMPCs) and to determine the mechanism of DNP-induced histamine release from RPMCs. After treatment of RPMC with DNP, mast cell degranulation was observed, and calcium uptake and histamine release were measured. DNP released the histamine, induced the mast cell degranulation, and increased the calcium uptake of RPMCs, in a dose-dependent manner. The results indicate that DNP can increase Ca-uptake and induce histamine release.

Atrial natriuretic peptide induces rat peritoneal mast cell activation by cGMP-independent and calcium uptake-dependent mechanism.

Atrial natriuretic peptide (ANP), a 28 amino acid basic polypeptide, is known to induce histamine release from human and rat mast cells in vitro and cause a wheel formation in rat skin. However, cellular events associated with histamine release are not clearly understood. In this study, we have examined the calcium flux and cGMP formation associated with histamine release in the ANP-treated mast cells. ANP, in vitro, induced mast cell degranulation and histamine release in a dose-dependent manner. ANP also induced an enhanced calcium uptake into cells and increased the cellular level of cGMP in mast cells. A high level of calcium in the media caused an inhibition of ANP-dependent histamine release but enhanced the level of intracellular cGMP of mast cells. ANP inducing a dose-dependent increase in vascular permeability of rat skin was confirmed by the extravasation of the circulating Evans blue. The results indicate ANP induced the histamine release and an increase in vascular permeability through mast cell degranulation in cGMP-independent and calcium uptake-dependent manner.

Immunoglobulin E-dependent active fatal anaphylaxis in mast cell-deficient mice.

Mast cells have long been believed to be the central effector cells in the development of immunoglobulin (Ig)E-dependent anaphylaxis. In this study, we investigated the role of mast cells in IgE-dependent hapten-induced active fatal anaphylaxis using mast cell-deficient WBB6F1- W/Wv (W/Wv) and congenic normal (+/+) mice. Although a 5-min delay in shock signs and death were observed in W/Wv mice, 100% fatal reactions to penicillin V (Pen V) occurred in both +/+ and W/Wv mice. Administration of monoclonal anti-IL-4 antibody completely prevented the fatal reactions, and the effect of anti-IL-4 was associated with its suppressive activity on Pen V-specific serum levels of IgE, but not IgG. The platelet-activating factor (PAF) antagonist, BN 50739, completely prevented the fatal reactions in both strains of mice. Our kinetic study revealed, in contrast to no elevation of plasma histamine level in W/Wv mice, high levels of PAF in the circulation after challenge in both +/+ and W/Wv mice, albeit to a lesser degree in the latter case. These data indicate that cells other than mast cells are sufficient to induce an IgE-dependent active fatal anaphylaxis by elaborating PAF, which is the critical mediator for fatal murine anaphylaxis.

United Kingdom scheme for external quality assessment in virology. Part I. General method of operation.

Developments in the United Kingdom national external quality assessment scheme for virology are described. There are about 198 participants (170 in the UK) who are enrolled for examination of any or all of five categories of specimen (distribution types). These are detection of rubella antibody (128 UK participants), detection of hepatitis B surface antigen (130 UK participants), general virus serology (86 UK participants), virus identification (85 UK participants), and electron microscopy (56 UK participants). Specimens of a sixth category (rubella IgM antibody), not yet formally established, have also been distributed to 67 UK participants. Specimens in each distribution type are sent out once or twice a year, and, except for rubella IgM antibody, participants have been given a score of 2, 1, 0 or -1 marks for their reports on each specimen. Their cumulative scores and performance ratings are calculated retrospectively over a 12 month period for each distribution type separately and for combined distributions. The performance rating is defined by the number of standard errors by which the individual's cumulative score differs from the mean for all participants and carries a + or - sign depending on whether the cumulative score lies above or below the mean. Performance ratings have been found generally to be close to the mean in rubella serology and detection of hepatitis B surface antigen but are more variable in virus identification and electron microscopy. Ratings of less than -1.96 are considered to be significantly worse than average and to constitute poor performance.