Arterial blood gas analysis in dogs with bronchomalacia

Canine bronchomalacia (CBM) is a structural airway disease leading to chronic cough and intermittent respiratory distress, primarily affecting elderly dogs of small breeds. Results of blood gas analysis have been reported in dogs with several diseases, but not yet in those with CBM. Eleven dogs with CBM were recruited in this study. Most dogs presented with mild hypoxemia and normocapnia, and all with increased alveolar-arterial difference for O₂ (A-aDO₂). In computed tomography, abnormal lung patterns, such as atelectasis and parenchymal band, were detected in all dogs, consistent with the regions affected by CBM. We conclude that CBM causes abnormal lung patterns and results in impaired oxygenation. Blood gas analysis is a useful tool for detecting mild pulmonary lesions and concurrent CBM.

Pharyngeal contraction secondary to its collapse in dogs with brachycephalic airway syndrome

Brachycephalic airway syndrome (BAS) is a common disease in certain "flat-faced" dog breeds. This syndrome includes stenotic nares, elongated and thickened soft palate, laryngeal collapse, and tracheal hypoplasia. Pharyngeal collapse is also commonly observed, but it is unclear if laryngopharynx motions are merely sequelae or actually contribute to BAS respiratory symptoms. Laryngopharynx motion was imaged using dynamic four-dimensional computed tomography (4D-CT) during spontaneous respiration in four dogs with different BAS types. Dynamic 4D-CT showed laryngopharynx motion in the following order during inspiration: pharyngeal collapse, contraction, and laryngospasm. We concluded that dynamic 4D-CT is a highly-detailed diagnostic approach for detecting laryngopharynx motion. Pharyngeal contraction during inspiration appears to contribute toward the worsening of clinical respiratory signs of BAS.

Impact of intracranial hypertension on the short-term prognosis in dogs undergoing brain tumor surgery

The present study used data from anesthetic records to analyze variables of intracranial pressure (ICP) during brain tumor surgery or in the early postoperative period as prognostic indicators in dogs. Data from 17 dogs which were scheduled to undergo elective craniotomy for brain tumor surgery from 2009 to 2012 were included. Of these, five (29.4%) died during 14 days after the surgery because of respiratory failure following pneumonia (n=2), euthanasia due to difficulty in treatment of status epilepticus (n=1), tumor-bed hematoma (n=1), and unknown reason (n=1). In the 12 surviving dogs, neurological signs were improved or resolved at discharge. All dogs were administered midazolam and droperidol-fentanyl as premedication. General anesthesia was induced using propofol maintained on isoflurane and oxygen. Direct ICP was obtained via a Codman Microsensor strain gauge transducer. ICP hypertension (>13 mmHg) measured after 15 min of recovery from the moment after discontinuation of anesthesia by turning off the vaporizer dial was associated with poor prognosis (odds ratio, 20.00; 95% confidence interval, 1.39-287.60, P=0.028). This suggests that intracranial pressure influences the postoperative mortality rate in dogs undergoing brain tumor surgery.

The first case of feline sinonasal aspergillosis due to Aspergillus fischeri in Japan

Feline upper respiratory tract infection due to Aspergillus spp. is considered an emerging disease, with the number of reported cases continuing to rise. In this study, we report the first case of feline sinonasal aspergillosis caused by Aspergillus fischeri in Japan. The patient presented after 2 months of progressive facial deformity around the nose and nasal discharge. The isolate from this case was susceptible to itraconazole (ITZ), voriconazole and micafungin, but was resistant to amphotericine B. However, the infected cat died approximately 1 month after referral, despite treatment for 12 days ITZ administered orally at 10 mg/kg.

Methylation of free-floating deoxyribonucleic acid fragments in the bronchoalveolar lavage fluid of dogs with chronic bronchitis exposed to environmental tobacco smoke

Background

The etiology of canine chronic bronchitis (CB) is not completely understood, although exposure to environmental tobacco smoke (ETS) affects the airway inflammatory responses in some dogs with CB. The mechanism by which this occurs is unknown.

Findings

We investigated the concentrations and methylation rates of free-floating DNA fragments in bronchoalveolar lavage fluid (BALF) from dogs with chronic bronchitis. Based on serum cotinine levels, dogs with CB were divided into 2 groups: dogs that either had or had not been exposed to ETS. Our results demonstrated that the total nucleated cell and macrophage numbers increased in BALF of ETS-exposed dogs with CB. There were no significant differences in DNA concentrations and methylation rates in BALF between the 2 groups. However, 3 out of 8 dogs exposed to ETS had high DNA methylation rates in their BALF samples.

Conclusion

Our results suggest that ETS exposure leads to epigenetic modifications of cellular components in BALF in dogs diagnosed with CB.

Increased proportions of CCR4(+) cells among peripheral blood CD4(+) cells and serum levels of allergen-specific IgE antibody in canine chronic rhinitis and bronchitis

Canine chronic rhinitis (CR) and bronchitis (CB) are suspected to be allergic diseases. The present study tested whether dogs diagnosed with CR or CB present an atopic predisposition based on the ratio of CC chemokine receptor 4 (CCR4)-positive cells among peripheral blood CD4-positive cells (CCR4/CD4) and the serum levels of allergen-specific IgE antibodies. We found that most dogs with CR and CB have a possibility of atopic predisposition, and macrolide therapy constitutes an alternative to corticosteroid therapy in controlling the clinical signs.

Evaluation of a disintegrin-like and metalloprotease with thrombospondin type 1 repeat motifs 13 (ADAMTS13) activity enzyme-linked immunosorbent assay for measuring plasma ADAMTS13 activity in dogs

A disintegrin-like and metalloprotease with thrombospondin type 1 repeat motifs 13 (ADAMTS13) is a von Willebrand factor (vWF)-cleaving protease. Deficiencies in ADAMTS13 activity are known to cause thrombotic diseases in human beings. The present study evaluated whether the human ADAMTS13 activity enzyme-linked immunosorbent assay (ELISA) kit containing human vWF73 (a minimal substrate) and anti-N10 antibody (which specifically recognizes the decapeptide of the C-terminal edge of cleaved vWF by human ADAMTS13) is applicable to the measurement of canine plasma ADAMTS13 activity. Human vWF73 fused with a GST-tag and a His-tag (GST-hvWF73-His) was reacted with recombinant canine (rc)ADAMTS13, canine plasma, and human plasma, and then used in Western blotting using anti-N10 antibody. Linearity and intra- and interassay reproducibility of the human ADAMTS13 activity ELISA kit in canine plasma were further evaluated. Finally, plasma ADAMTS13 activity was measured in 13 healthy dogs and 6 dogs with bacteremia using the human ADAMTS13 activity ELISA kit. Cleaved products with a 28-kDa GST-hvWF73-His were detected specifically in rcADAMTS13 as well as in human ADAMTS13, and also in canine plasma by anti-N10 antibody, showing excellent linearity. Intra-assay coefficient of variation (CV) was 3.0-12.4%, and interassay CV was 11.5-12.5%. The ADAMTS13 activity was significantly lower in dogs with bacteremia than in healthy dogs (P = 0.0025). The current study revealed that the human ADAMTS13 activity ELISA kit is applicable for measurement of canine plasma ADAMTS13 activity to elucidate the pathology of thrombotic diseases in dogs.

Case report: First confirmed case of canine peritoneal larval cestodiasis caused by Mesocestoides vogae (syn. M. corti) in Japan

Canine peritoneal larval cestodiasis (CPLC) is an unusual parasitic disease in dogs that is caused by asexual proliferation of larval Mesocestoides. A 12 year-old spayed Shetland sheepdog with abdominal distension was referred to the Animal Medical Center at Nihon University, Japan. The presence of ascites was confirmed by abdominal ultrasonography and X-ray imaging. In addition, a number of parasites were observed in the ascitic fluid collected by abdominal paracentesis. Each of the whitish colored parasites was less than 1mm in size. The parasites were morphologically identified as Mesocestoides sp. tetrathyridia. The parasites had four suckers and calcareous corpuscles, but no hooks or rostellum. Mitochondrial (mt) 12S rDNA and mt cytochrome c oxidase subunit 1 DNA amplified from the tetrathyridia were used for molecular identification to species level. DNA sequence analysis showed that the tetrathyridia shared more than 99% identity with M. vogae (syn. M. corti) for each gene. The patient was treated with a standard dose (5mg/kg) of praziquantel, which was administered subcutaneously twice at an interval of 14 days. This resulted in successful deworming. This is the first case that CPLC was diagnosed in a dog that had never been taken outside of Japan, indicating that M. vogae is distributed in this country.

Bronchoalveolar lavage fluid and serum canine surfactant protein A concentrations in dogs with chronic cough by bronchial and interstitial lung diseases

We measured bronchoalveolar lavage fluid (BALF) and serum canine surfactant protein (cSP)-A concentrations in dogs with chronic cough. There were no significant differences between bronchial and interstitial lung diseases in BALF cSP-A concentrations. However, serum cSP-A concentrations in dogs with the interstitial lung disease as diffuse panbronchiolitis and idiopathic pulmonary fibrosis were significantly higher than those in dogs with the bronchial disease as chronic bronchitis. These results suggest that serum cSP-A concentrations may be a useful and noninvasive biomarker to understand the existence of interstitial lung damage in dogs with chronic cough.

The characteristics of short- and long-term surviving Shiba dogs with chronic enteropathies and the risk factors for poor outcome

Background

The objectives of this study were to investigate the differences in the characteristics of short- and long-term surviving dogs, and the factors that predict poor outcome in Shiba dogs with chronic enteropathies (CE).

Methods

A total of 25 Shiba dogs were included in this study, and classified as either short-term (≤6 months) survivors (Ss; n=16) or long-term (>6 months) survivors (Ls; n=9). The clinical and clinicopathological variables, histopathology, response to therapy, and outcomes were investigated between groups. Furthermore, these factors were tested for their ability to predict poor outcome.

Results

All CE dogs were diagnosed as having inflammatory bowel disease (IBD) with lymphocytic-plasmacytic enteritis (LPE). Age and canine inflammatory bowel disease activity index (CIBDAI) were significantly higher in the Ss group than in the Ls group (age: p = 0.035, CIBDAI: p = 0.018), as determined via univariate logistic regression analysis. According to receiver operator characteristic (ROC) curve analysis, the best predictors of poor outcome were age and CIBDAI, with the cutoffs determined as 7 years and 9 points, respectively. The majority of the cases (84%) responded to initial treatment; in particular, 75% of dogs in Ss group responded to therapy. The time to response (days) to the initial treatment in the Ss group (median 42.5 days, range: 20-91 days) was significantly shorter than that of the Ls group (median 285 days, range: 196-1026 days). Approximately half (55.5%) of the dogs in the Ls group died due to relapse of CE.

Conclusions

This study suggested that there is a high risk of early mortality in Shiba dogs with CE, particularly if the dogs are older (>7 years) and have a high CIBDAI score (>9 points). There appears to be a possibility of early mortality even if the initial treatment was efficacious. Furthermore, Shiba dogs with CE that become less responsive to initial therapy in the short-term (approximately 3 months) are more likely to have an early mortality. Thus, it is necessary to follow-up Shiba dogs with CE in the long-term, as approximately half of the long-term survivors eventually died due to a relapse of the signs.

Trace and major elements status in bronchoalveolar lavage fluid in dogs with or without bronchopneumonia

The aim of this study was to investigate the relationships between the bronchopneumonia and mean concentrations of those trace elements in bronchoalveolar lavage fluid (BALF). Twenty-nine dogs were included this study (17 healthy dogs and 12 dogs with respiratory disease). Each BALF sample had been obtained during bronchoscope examination by use of a standardized method. The concentrations of Al, Br, Ca, Cu, Fe, K, Ni, P, Si, Sr and Zn in BALF were measured by the particle-induced X-ray emission method. We found no relationship between the bronchopneumonia and the levels of elements in the BALF, except Ca, P and Zn. The dogs with respiratory disease were found to have a large amount of Ca and Zn, and a high Ca/P and Zn/Cu ratios in BALF compared to those without respiratory disease.

Malignant transformation of T-cell large granular lymphocyte leukemia in a dog

An 8-year-old spayed female Golden Retriever was referred to us for evaluation of mild lymphocytosis. The peripheral lymphocytes were comprised of mostly large granular lymphocytes (LGLs), and flow cytometry showed that they were mostly CD3+8+ T lymphocytes. Clonal rearrangement of the T-cell receptor gene was identified in the peripheral blood, and the dog was therefore diagnosed with LGL chronic leukemia. The dog was subclinical without treatment until hospitalization on day 154, at which point the lymphocytes looked like lymphoblasts and the surface markers changed to CD3-8-. This was regarded as malignant transformation from LGL chronic leukemia to the acute type. Sequential chemotherapy was started, but the dog died on day 190. Necropsy revealed tumor cell infiltration into the heart, skin, and brain.

Relationship between hair elements and severity of atrioventricular block in horses

The aim of this study was to investigate the relationships between the mean concentrations of trace elements and the severity of the second-degree atrioventricular (AV) block in the mane hair of horses. Electrocardiographs of horses were continually recorded for 6 h using a holter cardiac monitor to determine dropped ventricular beats (DVBs) which can be used as an indicator of the severity of the AV block. Mane hair Ca, Cu, Mg, and Zn concentrations were measured by the particle-induced X-ray emission method. The Zn/Cu ratio and Ca concentration in mane hair were significantly and positively correlated with the hourly DVBs in horse with a second-degree AV block (p<0.01, r2=0.485; p<0.05, r2=0.351, respectively). Proposed diagnostic cutoff points for hair Ca concentration and Zn/Cu ratio based on receiver operating characteristics curves analysis in detecting second-degree AV block were set at 1536 microg/g and 26.0, respectively. Those results with horse hair suggest that the evaluation of the Ca, Cu, Mg, and Zn status in mane hair by this method is strongly related to the severity of second-degree AV block and might predict the susceptibility of an individual much before the development of the symptom.

A case of feline pancreatitis

A 14-year-old, spayed female, domestic shorthair cat was referred to us with anorexia, pyrexia, and jaundice. Total bilirubin (TBIL) and feline trypsin-like immunoreactivity (fTLI) levels were remarkably high. Based on laparoscopic biopsy of the pancreas, the cat was diagnosed as having pancreatitis. As a result of treatment with a synthetic protease inhibitor and corticosteroid, the TBIL and fTLI values returned to normal and the clinical course was good.

Isoflurane anaesthesia in four sea lions (Otaria byronia and Zalophus californianus)

OBJECTIVE

To (1) evaluate a purpose-built chamber for inducing isoflurane anaesthesia in sea lions and (2) assess isoflurane as an anaesthetic for dental surgery in these species.

STUDY DESIGN

Prospective case study.

ANIMALS

Four sea lions, aged between 5 and 12 years and weighing 74-110 kg, with dental disease.

METHODS

Sea lions were restrained in a custom-built acrylic chamber into which 5% isoflurane (vapourizer setting) was delivered in O(2) (30 L minute(-1)) from three anaesthetic machines. When the animals were recumbent, the chamber was opened and induction completed using a face mask. Anaesthesia was maintained with 1.5-3.0% isoflurane (vapourizer setting) for 10-15 minutes and after tracheal intubation, was maintained with 1.0-3.0% isoflurane (end-tidal) for 41-255 minutes, using a partial rebreathing system with CO(2) absorption.

RESULTS

During induction, the sea lions attempted to support their weight on their thoracic limbs before slipping into sternal or lateral recumbency. Sea lions underwent either root canal surgery, 'crowning' or canine tooth extraction. The animals were completely unresponsive during these operations and apnoea was never encountered at any point during anaesthesia. After surgery, the sea lions were placed into transport cages and their tracheae extubated once they began to move their heads. Thereafter, recovery from anaesthesia was smooth and no signs of distress were observed. Animals were able to raise their forequarters using their flippers within 1 hour of the operation and were returned to the aquarium about 2 hours after surgery.

CONCLUSIONS AND CLINICAL RELEVANCE

The purpose-built induction chamber is safe for inducing isoflurane anaesthesia in spontaneously breathing sea lions and isoflurane is an effective anaesthetic in this species.

Diabetes mellitus after resection of hepatocellular carcinoma with hypoglycemia in a dog

A 10-year-old male beagle was referred to us with seizure related to hypoglycemia and a large intraabdominal mass. Based on various types of imaging and a laparoscopic biopsy, the intraabdominal mass was diagnosed as a hepatocellular carcinoma (HCC) of the quadrate lobe. The hypoglycemia was suspected to be associated with the HCC. After lobectomy of the quadrate lobe was performed, blood glucose levels continued to increase to higher than normal values and sugar was detected in the urine. The dog was diagnosed as diabetes mellitus (DM) and was treated with insulin for over two years after the surgery.

Molecular cloning of canine mucosal addressin cell adhesion molecule-1 cDNA and its expression in normal tissues

A cDNA encoding canine mucosal addressin cell adhesion molecule-1 (MAdCAM-1) was cloned. The entire open reading frame of canine MAdCAM-1 cDNA comprises 1137 bp, corresponding to 378 amino acid residues. The deduced amino acid sequence of canine MAdCAM-1 was 55.2%, 53.7%, and 52.4% identical to rat, mouse, and human MAdCAM-1, respectively. Canine MAdCAM-1 appeared to contain two immunoglobulin-like domains at the N-terminus, followed by a mucin-like domain and a third immunoglobulin-like domain. The structures of the dog, rat, and mouse proteins are likely similar because all of the cysteine residues in the immunoglobulin-like domains were conserved. Canine MAdCAM-1 mRNA was confirmed to express extremely in the mesenteric lymph node by RT-PCR.

Phenotypic Analysis of Hepatic T Lymphocytes in a Dog with Chronic Hepatitis

We evaluated hepatic T lymphocyte phenotypes in a dog with chronic hepatitis. Before treatment, numerous CD3+ lymphocytes were demonstrated in the liver, and the ratio of CD4+/CD8+ was remarkably high (2.96; reference range, 0.33+/-0.12). After treatment, CD3+ lymphocyte infiltration in the liver was reduced, and the ratio of CD4+/CD8+ decreased to 0.31. Therefore, hepatic T lymphocytes, especially CD4+ lymphocytes, might play a central role in the pathogenesis of this dog with chronic hepatitis.

Anaphylactoid response to Optison(R) and its effects on pulmonary function in two dogs

Two of 26 anesthetized dogs given the cardiac echo-enhancing agent Optison showed anaphylactoid responses (AR) related to the human albumin component of this agent. The episodes of AR were self-limited, and could be reproduced by human albumin injection alone. Gas exchange was maintained by mechanical ventilation and 5 cm H(2)O PEEP, and dispersion of ventilation remained normal during AR despite severe hypotension. We suggest that: (1) pre-screening by measuring blood pressure response to intravenous injection of small doses of Optison, and (2) availability of access to the airway in addition to emergency agents may be prudent preventive measures when Optison is used in animals to enhance echocardiographic imaging.

A case of shaker dog disease in a miniature dachshund

A male miniature Dachshund, twenty-two months of age, was referred with paroxysmal generalized tremors as a main clinical sign. There were no abnormalities in the neurological examination except the lack of bilateral menace responses, and in the magnetic resonance imaging of its brain. Analysis of cerebro-spinal fluid revealed a slight rise in protein concentration and an increase in the number of cells. This case with brown hair was diagnosed as the shaker dog disease, which has also been well known as "little white shakers" syndrome due to being found in small dogs with white hair, because the clinical signs were exactly analogous to the shaker dog disease, and the generalized tremors disappeared on the first day after the administration of prednisolone and diazepam.

Endoscopic Findings on Alimentary Lymphoma in 7 Dogs

Alimentary lymphoma was evaluated endoscopically in 7 dogs and a histopathological examination was made to detect the origin of neoplastic lymphocytes in 5 dogs. A solitary mass in the rectum (1 case), irregular cobblestone appearance in the duodenum (4 cases) and a moderate irregular appearance resembling lymphocytic-plasmacytic enteritis (2 cases) were endoscopically detected. Endoscopic ultrasonography demonstrated increased thickness of the duodenal wall in 2 cases examined. Neoplastic lymphocytes of alimentary lymphoma proved to originate in T cells in all 5 cases examined by immunohistochemical analysis.

Magnetic Resonance Imaging of Neuronal Ceroid Lipofuscinosis in a Border Collie

A castrated male border collie 23 months of age weighing 19.4 kg was referred to the Animal Medical Center of Nihon University with complaints of visual disturbance and behavioral abnormality, hyperacusis and morbid fear. The MRI examination revealed the slight dilated cerebral sulci and cerebellar fissures and left ventricular enlargement. This is the first report of MRI findings of canine neuronal ceroid lipofuscinosis.

The Incidence of Disseminated Intravascular Coagulation in Dogs with Malignant Tumor

The incidence of DIC in 208 dogs with a malignant tumor was evaluated. The incidence of DIC was 9.6% in dogs with a malignant tumor which was a solid tumor in all. In 164 dogs with a malignant solid tumor, the incidence of DIC was 12.2%. The incidence of DIC in dogs with hemangiosarcoma, mammary gland carcinoma and adenocarcinoma of the lung was significantly higher than that in dogs with other malignant tumors. These results suggested that special care in looking for DIC should be taken in dogs with a malignant solid tumor.

Beta-adrenergic or parasympathetic inhibition, heart rate and cardiac output during normoxic and acute hypoxic exercise in humans

Acute hypoxia increases heart rate (HR) and cardiac output (Qt) at a given oxygen consumption (VO2) during submaximal exercise. It is widely believed that the underlying mechanism involves increased sympathetic activation and circulating catecholamines acting on cardiac beta receptors. Recent evidence indicating a continued role for parasympathetic modulation of HR during moderate exercise suggests that increased parasympathetic withdrawal plays a part in the increase in HR and Qt during hypoxic exercise. To test this, we separately blocked the beta-sympathetic and parasympathetic arms of the autonomic nervous system (ANS) in six healthy subjects (five male, one female; mean +/- S.E.M. age = 31.7+/-1.6 years, normoxic maximal VO2 (VO2,max)=3.1+/-0.3 l min(-1)) during exercise in conditions of normoxia and acute hypoxia (inspired oxygen fraction=0.125) to VO2,max. Data were collected on different days under the following conditions: (1)control, (2) after 8.0 mg propranolol i.v. and (3) after 0.8 mg glycopyrrolate i.v. Qt was measured using open-circuit acetylene uptake. Hypoxia increased venous [adrenaline] and [noradrenaline] but not [dopamine] at a given VO2 (P<0.05, P<0.01 and P=0.2, respectively). HR/VO2 and Qt/VO2 increased during hypoxia in all three conditions (P<0.05). Unexpectedly, the effects of hypoxia on HR and Qt were not significantly different from control with either beta-sympathetic or parasympathetic inhibition. These data suggest that although acute exposure to hypoxia increases circulating [catecholamines], the effects of hypoxia on HR and Qt do not necessarily require intact cardiac muscarinic and beta receptors. It may be that cardiac alpha receptors play a primary role in elevating HR and Qt during hypoxic exercise, or perhaps offer an alternative mechanism when other ANS pathways are blocked.

Rostral lateral pontine infarction: neurological/topographical correlations

The authors correlated neurologic features of rostral lateral pontine infarct (rLPI) with lesion location on MRI. rLPI is a motor-sensory stroke presenting as crural monoparesis or crural dominant hemiparesis and segmental superficial or deep sensory disturbances. The dorsolateral pontine base causes crural paresis without supranuclear facial palsy.

Effects of DDAVP administrated subcutaneously in dogs with aspirin-induced platelet dysfunction and hemostatic impairment due to chronic liver diseases

To evaluate the hemostatic effects of desmopressin (DDAVP) in dogs with aspirin-induced platelet dysfunction and hemostatic impairment in chronic liver diseases, 3 microg/kg DDAVP was administrated subcutaneously. In aspirin-induced platelet dysfunction dogs (n=5), prolonged BMBT (buccal mucosal bleeding time) was shortened significantly after DDAVP injection (2.2 +/- 1.2 min, P<0.05). In dogs with chronic liver diseases (n=4), activated partial thromboplastin time (APTT) tended to shorten by 0.9 to 3.0 sec, and prolonged BMBT was shortened in two cases for 4.2 and 1.7 min after DDAVP injection. Therefore, the present results indicated that DDAVP shortened the prolonged BMBT in dogs with aspirin-induced platelet dysfunction and chronic liver disease. DDAVP might be helpful in hemostasis under invasive procedures such as biopsy or surgery for dogs with hemostatic impairment.

Effects of Optison on pulmonary gas exchange and hemodynamics

Optison is a contrast-enhancing agent used in myocardial contrast echocardiography. It consists of small albumin spherules (approximately 4-microm diameter) containing a fluorocarbon gas, octafluoropropane. It is injected IV and, thus, may cause pulmonary manifestations of microembolism. To determine if any such effects do occur, we injected sequential doses of 1, then 3 and then 5 mL Optison IV into 25 kg anesthetized dogs, and measured pulmonary hemodynamic and gas exchange variables frequently for 30 min after each dose. This was done in both 6 healthy and 6 pulmonary hypertensive animals, the latter produced by acute IV injection of 676-microm diameter polystyrene beads, raising pulmonary artery pressure from normal (15 mmHg) to 33 mmHg. Optison-injected animals were compared with albumin-injected controls. Two animals developed severe hypotension in response to albumin and could not be used. Lung compliance and wet/dry weight ratio were unaffected by Optison and no effects on gas exchange were seen at any dose or time in either group of dogs. In the healthy group, there was slight (1 mmHg per mL Optison, transient and delayed pulmonary hypertension without change in cardiac output, suggesting a vasoconstrictor rather than mechanical basis for these small effects. No such changes occurred in the pulmonary hypertensive group. These results imply that usual human doses of Optison (0.5 mL) will produce no significant hemodynamic or gas exchange effects in either healthy or pulmonary hypertensive dogs.

Role of the autonomic nervous system in the reduced maximal cardiac output at altitude

After acclimatization to high altitude, maximal exercise cardiac output (QT) is reduced. Possible contributing factors include 1) blood volume depletion, 2) increased blood viscosity, 3) myocardial hypoxia, 4) altered autonomic nervous system (ANS) function affecting maximal heart rate (HR), and 5) reduced flow demand from reduced muscle work capability. We tested the role of the ANS reduction of HR in this phenomenon in five normal subjects by separately blocking the sympathetic and parasympathetic arms of the ANS during maximal exercise after 2-wk acclimatization at 3,800 m to alter maximal HR. We used intravenous doses of 8.0 mg of propranolol and 0.8 mg of glycopyrrolate, respectively. At altitude, peak HR was 170 +/- 6 beats/min, reduced from 186 +/- 3 beats/min (P = 0.012) at sea level. Propranolol further reduced peak HR to 139 +/- 2 beats/min (P = 0.001), whereas glycopyrrolate increased peak HR to sea level values, 184 +/- 3 beats/min, confirming adequate dosing with each drug. In contrast, peak O(2) consumption, work rate, and QT were similar at altitude under all drug treatments [peak QT = 16.2 +/- 1.2 (control), 15.5 +/- 1.3 (propranolol), and 16.2 +/- 1.1 l/min (glycopyrrolate)]. All QT results at altitude were lower than those at sea level (20.0 +/- 1.8 l/min in air). Therefore, this study suggests that, whereas the ANS may affect HR at altitude, peak QT is unaffected by ANS blockade. We conclude that the effect of altered ANS function on HR is not the cause of the reduced maximal QT at altitude.

Validity of pulse oximetry during maximal exercise in normoxia, hypoxia, and hyperoxia

During exercise, pulse oximetry is problematic due to motion artifact and altered digital perfusion. New pulse oximeter technology addresses these issues and may offer improved performance. We simultaneously compared Nellcor N-395 (Oxismart XLTM) pulse oximeters with an RS-10 forehead sensor (RS-10), a D-25 digit sensor (D-25), and the Ivy 2000 (Masimo SETTM)/LNOP-Adt digit sensor (Ivy) to arterial blood oxygen saturation (Sa(O(2))) by cooximetry. Nine normal subjects, six athletes, and four patients with chronic disease exercised to maximum oxygen consumption (VO(2 max)) under various conditions [normoxia, hypoxia inspired oxygen fraction (FI(O(2))) = 0.125; hyperoxia, FI(O(2)) = 1.0]. Regression analysis for normoxia and hypoxic data was performed (n = 161 observations, Sa(O(2)) = 73-99.9%), and bias (B) and precision (P) were calculated. RS10 offered greater validity than the other two devices tested (y = 1.009x - 0.52, R(2) = 0.90, B+/-P = 0.3 +/- 2.5). Finger sensors had low precision and a significant negative bias (D-25: y = 1.004x - 2.327, R(2) = 0.52, B+/-P = -2.0 +/- 7.3; Ivy: y = 1.237x - 24.2, R(2) = 0.78, B+/-P = -2.0 +/- 5.2). Eliminating measurements in which heart rate differed by >10 beats/min from the electrocardiogram value improved precision minimally and did not affect bias substantially (B+/-P = 0.5 +/- 2.0, -1.8 +/- 8.4, and -1.25+/-4.33 for RS-10, D-25, and Ivy, respectively). Signal detection algorithms and pulse oximeter were identical between RS-10 and D-25; thus the improved performance of the forehead sensor is likely because of sensor location. RS-10 should be considered for exercise testing in which pulse oximetry is desirable.

A case of familial amyloid polyneuropathy homozygous for the transthyretin Val30Met gene with motor-dominant sensorimotor polyneuropathy and unusual sural nerve pathological findings

OBJECTIVE

To report a case of familial amyloid polyneuropathy homozygous for the amyloidogenic transthyretin (ATTR) Val30Met gene with motor-dominant sensorimotor polyneuropathy and unusual sural nerve pathological findings.

METHODS

Mass spectrometry analysis and polymerase chain reaction-restricting fragment length polymorphism were performed. A right sural nerve biopsy specimen was obtained for histological investigation.

SETTING

Academic medical center.

RESULTS

A 56-year-old Japanese man living in a local town (Nakajima, Japan) in Ishikawa Prefecture, a nonendemic area of type I familial amyloidotic polyneuropathy, had vitreous amyloidosis, motor-dominant sensorimotor polyneuropathy, erectile dysfunction, and urinary incontinence. He had neither orthostatic hypotension nor indolent diarrhea. Restriction enzyme analysis with EcoT22 I of amplified DNA and mass spectrometry analysis revealed homozygosity for ATTR Val30Met. Of 8 family members, 5 were evaluated and found to be heterozygous for ATTR Val30Met; a family history found no relative with the similar neurologic disorders. The sural nerve biopsy specimen showed focal edema and an amyloid deposit in the subperineural tissue, associated with moderate loss of myelinated and unmyelinated fibers.

CONCLUSIONS

In addition to the findings characteristic of homozygosity for ATTR Val30Met such as vitreous amyloidosis and relatively less autonomic involvements, this case had the unique findings of motor-dominant sensorimotor polyneuropathy and unusual sural nerve biopsy specimen results.

Amyotrophic lateral sclerosis associated with sarcoidosis

We report a rare association of amyotrophic lateral sclerosis (ALS) with incidental pulmonary and muscle sarcoidosis. A 63-year-old woman presented with slowly progressive weakness and atrophy of the extremities starting from the left leg. The biopsy of a small mass in the left gastrocnemius revealed a typical sarcoid nodule. She was treated with corticosteroid for possible sarcoid neuromyopathy. In spite of the treatment, her clinical course was relentlessly progressive and she died of bulbar palsy. Autopsy revealed a loss of motor neurons in the anterior horn, vacuolar degeneration of the lateral funiculus, and noncaseating granulomas in paratracheal lymph nodes and lungs. No granulomatous lesion or cellular infiltration was found in the spinal cord.

Carpal bone movements in gripping action of the giant panda (Ailuropoda melanoleuca)

The movement of the carpal bones in gripping was clarified in the giant panda (Ailuropoda melanoleuca) by means of macroscopic anatomy, computed tomography (CT) and related 3-dimensional (3-D) volume rendering techniques. In the gripping action, 3-D CT images demonstrated that the radial and 4th carpal bones largely rotate or flex to the radial and ulnar sides respectively. This indicates that these carpal bones on both sides enable the panda to flex the palm from the forearm and to grasp objects by the manipulation mechanism that includes the radial sesamoid. In the macroscopic observations, we found that the smooth articulation surfaces are enlarged between the radial carpal and the radius on the radial side, and between the 4th and ulnar carpals on the ulnar side. The panda skilfully grasps using a double pincer-like apparatus with the huge radial sesamoid and accessory carpal.

Four cases of lowered urethral pressure in canine ectopic ureter

To evaluate the function of the constrictor urethrae of dogs that had urinary incontinence and were diagnosed as having ectopic ureter, the urethral pressure profile (UPP) was measured by means of a microchip catheter transducer. The UPPs (14.5 +/- 3.3 mmHg) of the four dogs suffering from ectopic ureter were much lower (p<0.001) than the UPPs of clinically healthy female dogs (35.3 +/- 5.7 mmHg). In the cases of ectopic ureter, it was shown that the UPP was lowered, and it was suggested that this would lead to the expression of urinary incontinence.

Safe and efficacious dosage of flecainide acetate for treating equine atrial fibrillation

To determine a safe and efficacious dose of flecainide acetate for treating equine atrial fibrillation (Af), the safe dosage level was determined by injecting 1, 2, or 3 mg/kg i.v. of 1% flecainide acetate solution at a rate of 0.2 mg/kg/min to five clinically healthy horses. Clinical signs and the ECG were monitored (HR, PR, QRS, and QT intervals) and blood was taken to measure the plasma flecainide concentration pre- and post-administration. No abnormal signs were observed in the 1- or 2-mg/kg groups, while agitation was observed in three of five horses in the 3-mg/kg group. The QRS, and QT intervals for the 3-mg/kg group increased significantly. The peak plasma flecainide concentrations were 1.316 +/- 358 (SD) ng/ml, 1,904 +/- 314 ng/ml, and 2,251 +/- 387 ng/ml for the 1-, 2-, and 3-mg/kg groups, respectively. To evaluate the efficacy of flecainide, Af was induced by right atrial pacing in six clinically healthy horses, and 1% flecainide acetate solution was then administered until they converted to sinus rhythm. All horses with induced Af converted. For the conversion, a total dose of 1.40 +/- 0.63 mg/kg flecainide was required, the duration of administration was 7.00 +/- 3.15 min and plasma flecainide concentration at conversion was 1,303 +/- 566 ng/ml. In conclusion, flecainide acetate is a safe and effective antiarrhythmic agent for equine Af, and the clinically effective dosage is 1 to 2 mg/kg.

[Two cases of thalamic infarction presenting with "thalamic astasia"]

We report two cases of so-called 'thalamic astasia', associated with thalamic infarction. A 76-year-old-man suddenly noted to fall down to the left side without severe hemiparesis. An MRI showed an infarction in the superolateral portion of the right thalamus. Over eight weeks, his astasia gradually disappeared. A 69-year-old-man suddenly noted inability to stand with loss of balance. He showed mild hemiparesis, hypesthesia and cerebellar signs on the right side. Although right hemiparesis was slight, he was unable to stand by himself. An MRI demonstrated an infarction in the ventrolateral to ventroposterior portion of the left thalamus. Three weeks later, his symptoms except for cerebellar ataxia remarkably disappeared. The overlapped MRI lesions of these two cases were localized in the ventrolateral thalamus, such as Vimi (nucleus ventrointermedii internus), Vci (nucleus ventrocaudalis internus), Cemc (nucleus centralis thalami magnocellularis). These lesions are so-called 'vestibular thalamic nuclei', in which fibers from vestibulocerebellum are terminated. Involvement of the thalamic connectivity explains that two patients noted inability to stand. Thus we concluded that these two patients had thalamic astasia, described by Masdeu and Gorelick.

Cyclic GMP/cyclic GMP-dependent protein kinase system prevents excitotoxicity in an immortalized oligodendroglial cell line

Previously, we have demonstrated that excitotoxicity of oligodendrocyte-like cells (OLC), differentiated from immortalized rat O-2A progenitor cells (CG-4 cells), is prevented by cyclic AMP-elevating agents. We now report that some agents that elevate cyclic GMP prevent OLC excitotoxicity. Kainate-induced injury was prevented by cyclic GMP analogues (8-bromo-cyclic GMP and dibutyryl cyclic GMP), a guanylate cyclase activator [atrial natriuretic peptide (ANP)], and phosphodiesterase inhibitors [3-isobutyl-1-methylxanthine (IBMX), ibudilast, propentofylline, and rolipram]. When both forskolin and 8-bromo-cyclic GMP were added, kainate-induced injury was additively prevented. There was a strong positive correlation between suppression of kainate-induced Ca2+ influx and prevention of injury by these chemicals. The measurement of intracellular cyclic AMP and cyclic GMP by radioimmunoassay demonstrated the following: an increase of cyclic GMP with treatment with 8-bromo-cyclic GMP, dibutyryl cyclic GMP, and ANP; an increase of cyclic AMP with treatment with ibudilast and rolipram; and an increase of both cyclic AMP and cyclic GMP with treatment with IBMX and propentofylline. Kainate-induced Ca2+ influx was decreased by 8-(4-chlorophenylthiol)-guanosine-3',5'-monophosphate, an activator of cyclic GMP-dependent protein kinase (PKG), or okadaic acid, an inhibitor of protein phosphatases 1 and 2A. RT-PCR and westem blotting of OLC demonstrated transcription of PKG II gene and translation of PKG Ibeta mRNA, but no translation of PKG Ialpha mRNA. Therefore, we concluded that the cyclic GMP/PKG system prevents OLC excitotoxicity.

Non-N-methyl-D-aspartate glutamate receptors mediate oxygen--glucose deprivation-induced oligodendroglial injury

Cells of oligodendroglial lineage are susceptible to oxygen and glucose deprivation. When oligodendrocyte-like cells differentiated from CG-4-immortalized rat O-2A progenitor cells were exposed to hypoxia alone or glucose deprivation alone for 48 h, release of lactate dehydrogenase (LDH) into the culture medium did not increase. However, when cells were deprived of both oxygen and glucose for 6 or 12 h preceding reoxygenation for 2 h, LDH release increased. Adding glucose to the medium protected against cell death and increased lactate production in a concentration-dependent manner. Cell damage induced by deprivation of oxygen and glucose was prevented by calcium-free medium or by non-N-methyl-D-aspartate glutamate receptor (GluR) antagonists, such as 6-cyano-7-nitroquinoxaline-2,3-dione or LY293558, but not by the voltage-dependent calcium channel blocker, nimodipine, or by the N-methyl-D-aspartate GluR antagonist, MK-801. The glutamate concentration in the medium from cells exposed to oxygen-glucose deprivation for 12 h was 49.70+/-3.04 microM/l, which is sufficient to activate GluRs during deprivation of oxygen and glucose. Apoptotic cells detected by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end-labeling (TUNEL) or Hoechst 33258 staining did not increase in cells exposed to oxygen-glucose deprivation for 12 h and subsequent reoxygenation for 2 h. No DNA laddering was detected by agarose gel electrophoresis from cells exposed to deprivation of oxygen and glucose. Neither acetyl-YVAD-CHO, an inhibitor of caspase-1-like proteases, nor acetyl-DEVD-CHO, an inhibitor of caspase-3-like proteases, prevented oxygen-glucose deprivation-induced injury. Thus, oxygen and glucose deprivation causes calcium-influx-induced necrotic cell damage in cells of oligodendroglial lineage via non-N-methyl-D-aspartate GluR channels.

[A 54-year-old man with action myoclonus, parkinsonism and epilepsy]

We describe 3-year clinical course of a 54-year-old Japanese man who presented with action myoclonus, parkinsonism and epilepsy. There was no family history or consanguinity. The patient was well until the age of 51 years (in 1986), when he noted slow movements, memory disturbance and left hand tremor. He was treated with anti-Parkinson drugs without any improvements. Soon thereafter, he developed a gait disturbance and generalized tonic clonic seizures. He was admitted to our service at the age of 53 years. General physical examination revealed no hepatosplenomegaly. Neurological examination showed mild dementia. Neither retinal pigmentation nor cherry red spot was noted. He was unable to walk due to marked frozen gait. His upward gaze was limited and saccadic eye movement was slow. He had action myoclonus in both upper extremities and resting tremor on the left side. He showed mild left hemiparesis. Deep tendon reflex was hyperactive in both side with extensor plantar responses. MRI demonstrated cortical atrophy, especially marked at the bilateral temporal lobes with a right side predominance. Leukocyte lysosomal enzyme activities of beta-hexosaminidase, beta-galactosidase and sialidase were within normal limits. The patient died of pneumonia on April 25, 1989. At the time of a neurological CPC, neurologists reached the clinical diagnosis of adult-type neuronal ceroid-lipofuscinosis. Postmortem examination revealed bilateral bronchopneumonia. The brain weighed 1,219 g and showed atrophy of the temporal lobes. Histological examination showed neuronal cells with swollen cytoplasm and lipofuscin-like granules throughout the CNS, including the cerebral cortex, thalamus, substantia nigra, motor nuclei of the brain stem, dentate nuclei, inferior olivary nuclei. Clarke's nuclei and anterior horn cells. Marked neuronal loss was noted in the right temporal lobe and substantia nigra. Electron micrographs of the frontal cortex revealed "fingerprint profiles" in the cytoplasm of neuronal and glial cells. Pathological findings were consistent with the diagnosis of adult-type neuronal ceroid-lipofuscinosis (Kufs' disease).

[Apraxia of eyelid closure in a patient with progressive supranuclear palsy]

We reported a 68-year-old man with progressive supranuclear palsy who present with apraxia of eyelid closure. He showed horizontal and vertical supranuclear ophthalmoplegia, neck dystonic posture, pseudobulbar palsy and subcortical dementia. He opened his eyes almost all day long except for sleeping. His spontaneous blinking was noted at less than 1 per a minute. Although he closed his eyes reflexively, he could not close his eyes by verbal command. He occasionally closed his eyelids by using both hands. The surface electromyographic (EMG) findings revealed that the frequency of frontal muscle contraction did not decrease, and rather increased during verbal command to close his eyes. The contraction frequency of orbicularis oculi muscle did not increase by the command of voluntary eyelid closure. It is suggested that abnormal contractions of frontalis and orbicularis oculi muscles which are correlated in eyelid closing and opening might contribute to the apraxia of eyelid closure.

CT examination of the guttural pouch (auditory tube diverticulum) in Przewalski's Horse (Equus przewalskii)

The domestic horse (Equus caballus) have the large symmetrical guttural pouches (the auditory tube diverticulum) formed by saccate bulge of the auditory tube. In this study, CT examination was carried out in the head of Przewalski's horse (Equus przewalskii), the only true wild horse living at present. As results of the examination, Przewalski's horse possessed the large symmetrical guttural pouches divided into medial and lateral compartments by the stylohyoid bone. Moreover, the right and left guttural pouches meet each other at the median part to form a thin septum. As CT sections get close to the part of the occipital condyle, the lateral compartment disappeared, and the medial compartment gradually became small toward the base of the skull. These results indicate that the nuchal-basal part of the medial compartment is not well-developed as compared with the domestic horse.

CT examination of the manipulation system in the giant panda (Ailuropoda melanoleuca)

The manipulation mechanism of the giant panda (Ailuropida melanoleuca) was examined by means of CT (computed tomography) and 3-dimensional (3-D) Volume Rendering techniques. In the 3-D images of the giant panda hand, not only the bones but also the muscular system was visualised. Sections of the articulated skeleton were obtained. It was demonstrated that the hand of the panda is equipped with separately moulded manipulation units as follows: (1) the radial sesamoid (RS), the radial carpal, and the first metacarpal (R-R-M) complex; and (2) the accessory carpal (AC) and the ulnar (A-U) complex. When the giant panda grasps anything, the R-R-M complex strongly flexes at the wrist joint, the RS becomes parallel with the AC, and the phalanges bend and hold the object. It is shown that the well-developed opponens pollicis and abductor pollicis brevis muscles envelop and fix the objects between the R-R-M complex and the phalanges during grasping.

MRI examination of the masticatory muscles in the gray wolf (Canis lupus), with special reference to the M. temporalis

We examined the head of the gray wolf (Canis lupus) using MRI methods. Although the arising surface of the M. temporalis was not so enlarged in the frontal bone, the small frontal bone did not disturb the M. temporalis from occupying the lateral space of the frontal area in the gray wolf as in the domesticated dog. In the gray wolf, it is suggested that the M. temporalis may not be well-developed in terms of size of arising area, but in the thickness of running bundles. We suggest that the dog has changed the three-dimensional plan of the M. temporalis during the domestication and that the M. temporalis has developed a large arising surface in the frontal bone and lost the thickness of belly in the frontal area in accordance with the enlargement of the frontal bone and the increase in brain size.

[Ibudilast prevents oxygen-glucose deprivation-induced oligodendroglial injury]

Previously we have demonstrated that ibudilast, which is used clinically for treating patients with asthma and cerebrovascular diseases, prevents excitotoxicity of oligodendroglial lineage mediated by Ca2+ influx via non-N-methyl-D-aspartate (NMDA) glutamate receptor (GluR) channels. We here present a finding that ibudilast prevents oxygen-glucose deprivation (OGD)-induced oligodendroglial injury. The oligodendrocyte-like cells (OLC), differentiated from the CG-4 cell line established from rat oligodendrocyte-type-2 astrocyte (O-2A) progenitor cells, were exposed to hypoxia in the absence of glucose for 12 h and subsequent reoxygenation for 2 h. Cell damage was evaluated by measuring activity of lactate dehydrogenase (LDH) released into the culture medium. OGD for 12 h induced 30 to 50% LDH release into the medium. OLC damage induced by deprivation of oxygen and glucose was prevented by ibudilast at concentrations of > or = 50 microM. The protection given by ibudilast against OGD-induced injury was enhanced by prostacyclin (PGI2). OGD-induced OLC injury was prevented by 6-cyano-7-nitroquinoxaline-2, 3-dione (CNQX), an inhibitor of non-NMDA GluR or deprivation of Ca2+ from culture medium. While ibudilast increased intracellular cAMP at concentrations of > or = 10 microM, at least 100 microM concentrations were needed to increase intracellular cGMP. Therefore, we concluded that ibudilast prevented OGD-induced oligodendroglial injury possibly by increasing intracellular cAMP which modulates Ca2+ influx via non-NMDA GluR channels.

Intrinsic atrioventricular conductive function in horses with a second degree atrioventricular block

The atrioventricular (AV) conductive functions were investigated before and after the pharmacological autonomic nervous blockade (PAB) through the electrophysiological study on six horses (AV block group) in which the dropped beats occurred more frequently (over 200 beats/24 hr) and on five horses (control group) in which the dropped beats occurred sporadically (under 200 beats/24 hr) or in which the arrhythmias were not recognized at all on the long-term electrocardiogram. As a result, AV conductivity, conduction time and refractoriness in the AV block group were lower, longer and higher, respectively, than those in the control group even after PAB. These results indicate the intrinsic AV conductive functions in the AV block group were withdrawing than in the control group.

Effects of altered FIO2 on maximum VO2 in the horse

Although the horse is considered an elite athlete with a specific VO2max some 2-4 times higher than man, maximal O2 transport is compromised both by moderately severe arterial desaturation and by failure to extract all O2 from blood perfusing exercising muscle. This prompted the present study to ascertain whether correction of arterial desaturation would proportionally augment VO2max and, if so, would O2 extraction behave in a manner predicted by diffusional transport limitation. Six two year old thoroughbreds were exercised to VO2max on a treadmill each on three separate occasions breathing gases of FIO2 = 0.15, 0.21 and 0.35, each used once in balanced order. VO2, ventilation, arterial and pulmonary arterial blood gases, pressures and lactate levels were measured both submaximally and maximally at each FIO2 and cardiac output was computed by mass balance for O2. At FIO2 = 0.21, VO2max = 143.9 +/- 4.8 ml kg-1 min-1, arterial saturation (SaO2) was 81.6 +/- 3.3% while venous PO2 (PvO2) was 15.3 +/- 1.4 Torr. At FIO2 = 0.35, VO2max was 172.6 +/- 8.2 ml kg-1 min-1, SaO2 reached 97.4 +/- 0.4% and PvO2 was 23.4 +/- 0.7 Torr. VO2max at FIO2 = 0.15 was 109.8 +/- 4.1 ml kg-1 min-1, SaO2 fell to 68.1 +/- 2.5% and PvO2 was 10.6 +/- 1.0 Torr, all changes being significant, p < 0.01. As FIO2 was varied, VO2max changed proportionally to calculated mean capillary Po2 as well as to total O2 delivery. These data confirm substantial O2 supply dependence of VO2max in the horse, and in such a manner as to be consistent with the hypothesis of combined diffusive and convective transport limitation within muscle.