Characterization of Giardia lamblia genotypes in dogs from Tucson, Arizona using SSU-rRNA and β-giardin sequences

The objective of this study was to determine if human genotypes of Giardia lamblia could be found in canine companion animals from urban and peri-urban environments in Tucson, Arizona. Canine fecal samples collected from the Humane Society of Southern Arizona between July 2006 and April 2009 were screened for G. lamblia infection using immunofluorescent microscopy and confirmed by polymerase chain reaction (PCR). Of the 672 samples screened, 196 were found positive by IFA and 185 of those positive were successfully amplified through PCR. Sequencing analysis showed samples were primarily of the C or D genotypes (n?=?154), or showing a mix of the C and D genotypes (n?=?10). One sample showed a mixed infection of a human genotype (A) and a dog-specific genotype (C). These data are consistent with previous studies showing dog specific genotypes to be dominant in environments where dog-to-dog transmission is likely to occur, and provides further evidence that multiple genes should be targeted for more accurate genotype characterization.     

Characterization of a proteasome α-chain from Giardia lamblia

To begin to characterize the components of the 20S proteasome of Giardia lamblia, we have cloned a genomic sequence encoding an α-chain (type α3/C9, predicted size 244 amino acid residues). Southern analysis indicated that a single gene codes for this protein, and a Northern blot exhibited a single signal at 850 nt. An antiserum against a C-terminal fragment of the α-chain expressed in Escherichia coli reacted with a single protein band of M _r 27,000 that was present at constant levels in trophozoites and encysting cells. On a 2D blot of the purified 20S proteasome, we identified the crossreacting component as a single protein of IEP 6.0, in agreement with the IEP predicted by the coding sequence. Our data confirm that the G. lamblia 20S proteasome is typically eukaryotic in containing a set of diverged α-subunits. Received: 3 June 2000 / Accepted: 13 September 2000     

Intercellular Contact Protein β-Catenin in Neurons of the Habenula of the Rat Brain

Neuroscience and Behavioral Physiology - Studies were performed on frontal brain sections (n = 5) from Wistar rats using immunocytochemical methods. This is the first report on the detection of the...     

Receptor-mediated endocytosis and trafficking between endosomal–lysosomal vacuoles in Giardia lamblia

The early branching Giardia lamblia has highly polarized vacuoles, located underneath the plasma membrane, which have at least some of the characteristics of endosomes and of lysosomes. These peripheral vacuoles (PVs) are necessary for nutrient uptake and the maintenance of plasma membrane composition, but whether they carry out sorting and segregation of receptors and ligands is a matter of debate. Here, we showed that the internalization of low-density lipoprotein (LDL) to the PVs is highly dynamic in trophozoites with a rate similar to the internalization of the low-density lipoprotein receptor-related protein 1. Moreover, by analyzing receptor-mediated and fluid-phase endocytosis in living cells, we showed that after endocytosis LDL but not dextran moved laterally between the PVs. We speculate on PV functional heterogeneity and maturation in this parasite.     

Interaction of protein phosphatase 1δ with nucleophosmin in human osteoblastic cells

Protein phosphorylation and dephosphorylation has been recognized as an essential mechanism in the regulation of cellular metabolism and function in various tissues. Serine and threonine protein phosphatases (PP) are divided into four categories: PP1, PP2A, PP2B, and PP2C. At least four isoforms of PP1 catalytic subunit in rat, PP1α, PP1γ1, PP1γ2, and PP1δ, were isolated. In the present study, we examined the localization and expression of PP1δ in human osteoblastic Saos-2 cells. Anti-PP1δ antibody recognized a protein present in the nucleolar regions in Saos-2 cells. Cellular fractionation revealed that PP1δ is a 37 kDa protein localized in the nucleolus. Nucleophosmin is a nucleolar phosphoprotein and located mainly in the nucleolus. Staining pattern of nucleophosmin in Saos-2 cells was similar to that of PP1δ. PP1δ and nucleophosmin were specifically stained as dots in the nucleus. Dual fluorescence images revealed that PP1δ and nucleophosmin were localized in the same regions in the nucleolus. Similar distribution patterns of PP1δ and nucleophosmin were observed in osteoblastic MG63 cells. The interaction of PP1δ and nucleophosmin was also shown by immunoprecipitation and Western analysis. These results indicated that PP1δ associate with nucleophosmin directly in the nucleolus and suggested that nucleophosmin is one of the candidate substrate for PP1δ.     

α14-Giardin (annexin E1) is associated with tubulin in trophozoites of <Emphasis Type="Italic">Giardia lamblia</Emphasis> and forms local slubs in the flagella

In a previous study, we reported that the novel annexin XX1 (annexin E1), identical to α14-giardin, is specifically localized to the flagella and to the median body of the trophozoites. However, the mode of interaction and the direct partners involved remained unclear. In the present study, we show that α4-giardin obviously does not evenly distribute over the full length of the axonemes, but rather, resides at local slubs near the proximal part and the ends of the flagella. In immunocytochemical co-localization studies, the anti-giardin primary antibody exclusively reacted with distinct regions of the flagella in permeabilized cells, whereas the anti-tubulin antibody bound to all areas of the axonemes in the cells and to isolated cytoskeletons. Isolated cytoskeletons did not react with anti-giardin antibodies. α14-Giardin itself is able to assemble to multimeric structures. Taken together, our findings suggest that α14-giardin adheres to microtubules of the flagella via self-assembly that may regulated by Ser/Thr-phosphorylation. An erratum to this article can be found at     

Regulation of β-amyloid level in the brain of rats with cerebrovascular hypoperfusion

Cerebrovascular hypoperfusion occurs prior to clinical symptoms of Alzheimer's disease (AD) and represents the most accurate indicator predicting whether an individual develops AD in a future time. In order to explore the contribution of cerebrovascular hypoperfusion to AD, cerebrovascular hypoperfusion induced by bilateral carotid occlusion surgery in adult rats was used to investigate its impacts on spatial memory, amyloid-β protein (Aβ) production and clearance in the brain. The progressive spatial memory deficits were observed through Morris water maze test of the rats with cerebrovascular hypoperfusion induced by occlusion surgery. The memory deficits were accompanied with the increase of brain Aβ associated with Aβ overproduction due to the increased expression of β-amyloid precursor protein (APP) and enhanced activities of amyloid precursor protein cleavage enzymes such as β- and γ-secretases. Western blot and immunohistochemisty studies further revealed that cerebrovascular hypoperfusion could induce abnormal expression of β-amyloid receptor proteins including the receptor for advanced glycation end products (RAGE) and low-density lipoprotein receptor-related protein-1 (LRP-1), and result in a shift of immunoreactivity between neurons and vasculatures. Taken together, our results suggested that chronic cerebrovascular hypoperfusion could cause memory impairment and Aβ accumulation in brain associated with increased generation and impaired clearance of Aβ. Cerebrovascular hypoperfusion plays an important role in the pathogenesis and development of AD.     

Interaction of taurine and β-alanyl-L-histidine (carnosine) with the hypochlorite anion (ClO−)

Research Institute of Physicochemical Medicine, Ministry of Health of the Russian Federation, Moscow. (Presented by Academician of the Russian Academy of Medical Sciences Yu. M. Lopukhin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 114, No. 11, pp. 475–477, November, 1992.     

Changes in the Rhythmoinotropic Dependence of the Myocardium in Rats with Postinfarction Cardiosclerosis after β1-Adrenoreceptor Blocking

The rhythmoinotropic dependence of the papillary muscles was studied in rats with postinfarction cardiosclerosis after blocking of β₁-adrenoreceptors by concor (7 mg/kg daily). The development of postinfarction cardiosclerosis led to a reduction of the postextrasystolic potentiation and of potentiation induced by periods of rest. Preliminary blocking of β₁-adrenoreceptors stimulated the postextrasystolic contractions and contractions after periods of rest in the myocardium of rats with postinfarction cardiosclerosis. These results suggest that blocking of β₁-adrenoreceptors promotes an improvement of calcium-accumulating function of the cardiomyocyte sarcoplasmatic reticulum in the myocardium of rats with postinfarction cardiosclerosis. Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 147, No. 3, pp. 346–350, March, 2009     

Interleukin-18 Binding Protein in the Sera of Patients with Wegener’s Granulomatosis

Introduction  In the present study, we examined the levels of the pro-inflammatory cytokine IL-18 and its natural inhibitor, the IL-18 binding protein (IL-18BP), in sera of Wegener’s granulomatosis (WG) patients at various stages of the disease. Patients and Methods  Sera from eight consecutive biopsy-proven systemic WG patients (four men and four women; age at diagnosis 58.4 ± 13.8 years) were obtained longitudinally with a follow-up period of 55.2 ± 30 months. Sera obtained from 50 healthy subjects were used as controls. Results and Discussion  Serum levels of IL-18, IL-18BP, and free IL-18 obtained during an active phase of the disease (Birmingham Vasculitis Activity Score, BVAS > 10) were more than twofold higher than levels in the same patients during inactive disease stages (BVAS < 5; P < 0.002; P < 0.006, and P < 0.03 for IL-18, IL-18BP, and free IL-18, respectively). During inactive stages, the levels of these markers were comparable to those of healthy controls. The elevated levels of IL-18 and IL-18BP in sera during active stages of disease suggest a possible role in the pathogenesis and course of the WG. Conclusion  Despite the elevated IL-18BP levels during active disease, free IL-18 remained higher than in the inactive disease stages, suggesting a potential benefit of administration of exogenous IL-18BP as a novel therapeutic approach for active WG.     

The Role of β1,2-Adrenoceptors in the Amygdala in the Behavior of Rats with Different Levels of Freezing in Conditioned Reflex Fear

Neuroscience and Behavioral Physiology - Individual sensitivity to blockade of β1,2-adrenoceptors was studied by dividing rats into groups depending on the manifestation of conditioned reflex...     

Increased Expressions of Integrin Subunit β1, β2 and β3 in Patients with Acute Infection

Objective: Our previous studies have shown that integrin subunits β1, β2 and β3 were the core proteins of venous thrombi and potential useful biomarker of venous thromboembolism (VTE). Patients with acute infection have a high risk of VTE. In this study we explored that is there any relevance between core proteins and acute infection.Methods: A total of 230 patients (112 females) with clinically proven acute infection in the emergency unit were recruited into this study, meanwhile 230 patients without acute infection matched in sex and age were recruited as control group. Flow cytometry was done to measure the expressions of blood integrin β1, β2, β3 and cellular immunity (CD3, CD4, CD8, CD4/CD8, CD16CD56 and CD19). The association degree between increased core proteins and acute infection was analyzed by calculating the relative risk (RR).Results: The expression of integrin β1, β2 and β3 was markedly increased in patients with acute infection (P=0.000, 0.000 and 0.015, respectively). The relative risk ratio (RR) of increased integrin β1, β2 and β3 in acute infection patients was 1.424 (95%CI: 1.156-1.755, P=0.001), 1.535 (95%CI: 1.263-1.865, P=0.000) and 1.20 (95%CI: 0.947-1.521, P=0.148), respectively. Combined integrin β1, β2 and β3 analysis showed that the relative risk ratio (RR) of increased in patients with acute infection was 2.962 (95%CI: 1.621-5.410, P=0.001), and this relative risk (RR) rise to 3.176 (95%CI: 1.730-5.829, P=0.000) in patients with respiratory tract infection (RTI).Conclusion: As the core proteins of venous thrombi, integrinβ1, β2 and β3 were markedly increased expression in patients with acute infection, which maybe explain the increased risk of VTE in acute infection patients. A weakened immune system could be the basic condition of VTE occurrence.     

Immunolocalization of β- and δ-giardin within the ventral disk in trophozoites of Giardia duodenalis using multiplex laser scanning confocal microscopy

Immunolocalization of β- and δ-giardin in Giardia duodenalis trophozoites revealed that both giardins are strictly associated with the ventral disk (VD). Optical sectioning of the immunolabeled VD, together with quantitative colocalization of δ- and β-giardin immunoreactivity, demonstrated that δ-giardin is primarily localized to the ventral side, and β-giardin is localized to the dorsal side of the VD.     

Age-related differences in the response of blood stroke volume to stimulation of the sympathetic ganglion in rats with β-adrenoceptor blockade

Blood stroke volume in rats aging 21 and 56 days decreased during -adrenoceptor blockade with propranolol, but increased again by the 15th minute after treatment. Suprathreshold stimulation of the stellate ganglion decreased the stroke volume and increased the heart rate in control animals. Electrical stimulation after -adrenoceptor blockade was followed by a further decrease in stroke volume in young rats. In 100-day-old animals this parameter remained unchanged, while the cardiac output improved.Translated from Byulleten Eksperimentalnoi Biologii i Meditsiny, Vol. 138, No. 10, pp. 393–396, October, 2004     

Age-related differences in the response of blood stroke volume to stimulation of the sympathetic ganglion in rats with β-adrenoceptor blockade

Blood stroke volume in rats aging 21 and 56 days decreased during -adrenoceptor blockade with propranolol, but increased again by the 15th minute after treatment. Suprathreshold stimulation of the stellate ganglion decreased the stroke volume and increased the heart rate in control animals. Electrical stimulation after -adrenoceptor blockade was followed by a further decrease in stroke volume in young rats. In 100-day-old animals this parameter remained unchanged, while the cardiac output improved.Translated from Byulleten Eksperimentalnoi Biologii i Meditsiny, Vol. 138, No. 10, pp. 393–396, October, 2004