Clinical features, intestinal histopathology, and outcome in protein-losing enteropathy in Yorkshire Terrier dogs.

BACKGROUND: A poorly understood protein-losing enteropathy (PLE) disorder has been reported in Yorkshire Terrier dogs. OBJECTIVES: To describe clinical features, intestinal histopathology, and outcome in Yorkshire Terrier dogs with PLE, and to identify variables predictive of outcome. ANIMALS: Thirty client-owned Yorkshire Terrier dogs with PLE. METHODS: Retrospective study. Records of dogs with a diagnosis of PLE were reviewed. Intestinal histopathology was interpreted using the World Small Animal Veterinary Association gastrointestinal histopathology classification system. Discriminate analysis techniques were used to identify variables predictive of outcome. RESULTS: Females outnumbered males (20/30). Median age was 7 years (range 1-12). Common clinical signs were diarrhea (20/30), vomiting (11), ascites and abdominal distension (11), and respiratory difficulty (8). Histopathologic abnormalities included villous lymphatic dilatation, crypt lesions, villous stunting, and variable increases in cellularity of the lamina propria. All dogs were treated with glucocorticoids. Of 23 dogs with long-term follow-up, 9 had complete, and 3 had partial, resolution of signs, and 11 failed to respond to treatment. Median survival of responders was 44 months and of nonresponders was 12 months, with 4 dogs experiencing peracute death. Vomiting, monocytosis, severity of hypoalbuminemia, low blood urea nitrogen concentration, and villous blunting were predictive of survival <4 months. CONCLUSIONS: In addition to classic GI signs, Yorkshire Terriers with PLE often show clinical signs associated with hypoalbuminemia and low oncotic pressure. Lymphatic dilatation, crypt lesions, and villous stunting are consistent histopathologic findings. Clinical outcomes are variable, but many dogs experience remission of clinical signs and prolonged survival.

Risk factors for coughing in dogs with naturally acquired myxomatous mitral valve disease.

BACKGROUND: Cough often is reported as the primary clinical sign of congestive heart failure (CHF) in dogs with chronic degenerative myxomatous mitral valve disease (MMVD). Concurrent airway disease and compression of the left mainstem bronchus by a large left atrium also have been proposed as potential causes of coughing in these patients. OBJECTIVES: To investigate the association between the presence of coughing and different potential causes of cough, including CHF, abnormal radiographic airway pattern, and cardiomegaly in dogs affected by naturally acquired MMVD. ANIMALS: Two hundred six client-owned dogs. METHODS: Retrospective analysis performed on medical records of dogs affected by MMVD that underwent full cardiac evaluation, including echocardiographic examination and thoracic radiography. RESULTS: Univariate analyses showed that CHF is not a predictor of coughing (OR = 1.369; 0.723, 2.594), whereas abnormal radiographic airway pattern (OR = 3.650; 2.051, 6.496) and increased left atrial size observed radiographically (OR = 3.637; 1.904, 6.950) or echocardiographically (OR = 2.553; 1.436, 4.539) were significantly associated with coughing in dogs with MMVD. The same risk factors were significant in multivariate analyses. CONCLUSIONS AND CLINICAL IMPORTANCE: This study indicates that CHF is not significantly associated with coughing in dogs with MMVD. Instead, abnormal radiographic airway pattern and left atrial enlargement are associated with coughing in these patients. This important finding should be taken into account when considering diagnosis and clinical management of CHF in these dogs.

Amelioration of the cerebrovascular amyloidosis in a transgenic model of Alzheimer's disease with the neurotrophic compound cerebrolysin.

Increased production and reduced clearance of amyloid beta (Abeta) plays a central role in the pathogenesis of Alzheimer's disease (AD). We have recently shown that the neurotrophic peptide mixture Cerebrolysin (Cbl) has the ability of improving synaptic functioning and reducing amyloid deposition in a transgenic (tg) animal model of Alzheimer's disease (AD). Since in AD, potentially toxic Abeta aggregates accumulate not only around neurons but also in the blood vessels, then it is important to investigate whether bioactive compounds such as Cbl might have the capacity to ameliorate the age-related cerebral amyloid angiopathy (CAA) in tg models. To this end, tg mice expressing mutant human amyloid precursor protein (APP) under the Thy1 promoter were treated with Cbl or saline alone starting at 7 or 12 months of age for a total of three months. Neuropathological analysis with an antibody against Abeta showed that Cbl decreased amyloid deposition around the blood vessels in a time dependent manner. These effects were accompanied by a reduction in perivascular microgliosis and astrogliosis and increased expression of markers of vascular fitness such as CD31 and ZO-1. No lymphocytic infiltration was observed associated with Abeta in the vessels. Consistent with these findings, ultrastructural analysis showed that while in tg mice treated with saline alone there was an abundant accumulation of amyloid fibers in the vascular wall accompanied by thickening of the basal membrane and endothelial cell damage, in Cbl-treated mice there was considerable reduction in the subcellular alterations of endothelial and smooth muscle cells with preservation of basal membranes and intercellular junctions. Taken together, these results suggest that Cbl treatment might have beneficial effects in patients with cognitive impairment due to cerebrovascular amyloidosis by reducing Abeta accumulation and promoting the preservation of the cerebrovasculature.

An antiaggregation gene therapy strategy for Lewy body disease utilizing beta-synuclein lentivirus in a transgenic model.

Current experimental gene therapy approaches for Parkinson's disease (PD) and dementia with Lewy bodies (DLB) include the use of viral vectors expressing antiapoptosis genes, neurotrophic factors and dopaminergic system enzymes. However, since increasing evidence favors a role for alpha-synuclein accumulation in the pathogenesis of these disorders, an alternative therapy might require the transfer of genes that might block alpha-synuclein accumulation. beta-Synuclein, the nonamyloidogenic homologue of alpha-synuclein, has recently been identified as a potential candidate. Thus, in vivo transfer of genes encoding beta-synuclein might provide a novel approach to the development of experimental treatments for PD and DLB. To assess this possibility and to better understand the mechanisms involved, a lentiviral vector expressing human (h) beta-synuclein (lenti-beta-synuclein) was tested in a transgenic (tg) mouse model of halpha-synuclein aggregation. This study showed that unilateral intracerebral injection of lenti-beta-synuclein reduced the formation of halpha-synuclein inclusions and the accumulation of halpha-synuclein in synapses and ameliorated the neurodegenerative alterations in the tg mice. Both in vivo and in vitro coimmunoprecipitation and immunoblot experiments show that the mechanisms of beta-synuclein neuroprotection involve binding of this molecule to halpha-synuclein and Akt, resulting in the decreased aggregation and accumulation of halpha-synuclein in the synaptic membrane. Together, these data further support a role for beta-synuclein in regulating the conformational state of alpha-synuclein and suggest that this gene transfer approach might have potential for the development of alternative therapies for PD and DLB.

Elevated ovarian expression and serum concentration of alpha inhibin in the luteal phase during follicular development in the squirrel monkey (Saimiri boliviensis) compared to the human.

The goal of the present investigation was to determine in the squirrel monkey the source and pattern of inhibin, a hormone known to effect reproductive steroid levels via pituitary and ovarian mechanisms. Since this seasonally polyestrous species is known to have elevated serum levels of reproductive steroids compared to other primates, the levels of ovarian alpha subunit mRNA expression and serum total alpha inhibin, estradiol, progesterone, and luteinizing hormone were measured and compared to human levels. Expression of the alpha subunit was robust in monkey luteal tissue compared to expression in human luteal tissue. Squirrel monkey serum inhibin peaked 4 days after the luteinizing hormone surge and correlated with progesterone changes. These luteal serum levels of inhibin were greater than 12 times higher than the human levels yet bio-LH activities were less than in the human during the luteal phase. Inhibin concentrations during the nonbreeding season were generally half the levels measured in the breeding season and undetectable in ovariectomized animals. However, exogenous FSH stimulation induced a marked rise in inhibin, which correlated with an estradiol rise. In conclusion, abundant alpha inhibin subunit expression in the luteal ovary of the squirrel monkey and loss of serum delectability in ovariectomized animals indicates that the principle source of inhibin in the squirrel monkey is the ovary. Elevated serum inhibin levels during the luteal phase concurrent with ovulatory-size follicular development is unique among species studied thus far. Possible simultaneous inhibin production from both follicular and luteal tissue may be responsible for the exceptionally high inhibin levels.

Molecular characterization of plastid pyruvate kinase from castor and tobacco.

Clones encoding two different forms of plastid pyruvate kinase (PKp; EC 2.7.1.40) have been isolated from both castor and tobacco seed cDNA libraries. One form, designated PKpA, from castor was described in a previous report, and the tobacco homologue of PKpA has now been isolated. In addition, a second cDNA, designated PKpG, has been identified and sequenced in both species. Western blot analysis, using antibodies raised against protein overexpressed from these clones, indicates that they encode the two predominant polypeptides of plastid pyruvate kinase from developing castor endosperm. In castor, both PKpA and PKpG are encoded by single genes. In the allotetraploid Nicotiana tabacum, there are two copies of each, one derived from each of the progenitors of this species. The expression of the genes for PKpA and PKpG was examined in various tissues from both castor and tobacco. In castor, both forms are expressed in developing and germinating endosperm and in the root but neither is expressed in the leaf. In tobacco, both forms are expressed in developing seeds but in mature tissues, PKpA is most abundant in roots and PKpG in leaves.

Expression of the Genes for the alpha- and beta-Subunits of Pyrophosphate-Dependent Phosphofructokinase in Germinating and Developing Seeds from Ricinus communis.

Various tissues from both germinating and developing castor seeds (Ricinus communis L.) have been analyzed for the level of expression of the genes for the alpha- and beta-subunits of pyrophosphate-dependent phosphofructokinase (PFP). In tissues in which PFP is expressed, there is a single mRNA species of approximately 2 kilobases for each of the subunits. In germinating endosperm, the gene for the alpha-subunit is expressed at an earlier time after imbibition than that for the beta-subunit, whereas in developing castor seed endosperm, both genes are highly and coordinately expressed. During seedling development, there is tissue-specific expression of the two genes. Tissues in which there is a high level of mRNA correspond with tissues in which both subunits of PFP can be detected. The differential expression of the two subunit genes in germinating endosperm does not result in the presence of the alpha-subunit polypeptide in the absence of the beta-subunit polypeptide. Southern analysis of castor genomic DNA indicates the presence of a single gene for both the alpha- and beta-subunits of PFP in contrast with potato, in which there are at least two genes for each subunit.

Purification of the alliin lyase of garlic, Allium sativum L.

1. Alliin lyase (EC 4.4.1.4) was purified up to sevenfold from garlic-bulb homogenates. The enzyme was unstable to storage at -10 degrees , particularly in dilute concentrations, but the addition of glycerol (final concentration 10%, v/v) stabilized the activity completely for at least 30 days. 2. The purified enzyme had an optimum pH for activity at 6.5. The addition of pyridoxal phosphate stimulated the reaction rate and the stimulation became more marked as the purification proceeded. 3. Hydroxylamine (10mum) and cysteine (0.5mm) inhibited the enzyme activity by more than 80%. Spectral studies indicated that cysteine reacted with pyridoxal phosphate bound to the protein. 4. The K(m) values for S-methyl-, S-ethyl-, S-propyl-, S-butyl- and S-allyl-l-cysteine sulphoxides were determined. With S-allyl-l-cysteine sulphoxide the K(m) was 6mm and the V(max.) was greater than those with the other substrates tested. 5. The thioether analogues of the substrates were competitive inhibitors for the lyase reaction. The K(i) decreased with increasing chain length of the alkyl substituent. With S-ethyl-l-cysteine sulphoxide as substrate the K(i) was 33, 8 and 5mm respectively for S-methyl-, S-ethyl- and S-propyl-l-cysteine. 6. The addition of EDTA or Mg(2+), Mn(2+), Co(2+) or Fe(2+) stimulated the reaction rate. Other bivalent cations either had no effect or gave a strong inhibition. In the presence of EDTA no further increase of activity was observed with added Mg(2+).