Pathogenicity characteristics of an Iranian variant-2 (IS-1494) like infectious bronchitis virus in experimentally infected SPF chickens.

Avian infectious bronchitis (IB) is a major cause of economic loss to the poultry industry. IB virus primarily affects respiratory tract, but strains differ in their tropism for such other target organs as kidneys and alimentary tract. The objective of this study was to estimate the pathogenicity of an Iranian IB virus (IBV) variant (variant-2) which is one of the most prevalent isolates circulating in Iranian poultry farms. SPF chickens were intranasally inoculated with 104 EID50/0.1 ml of the virus. Sera, fecal swabs, and different tissue samples were collected on different days post infection. Clinical signs, gross pathology, and histological changes were recorded. The amount of virus genome was quantified in different tissues and feces using quantitative real-time PCR assay. The highest viral loads were detected in the feces and cecal tonsils. Real-time PCR results demonstrated variant-2 tropism for respiratory tract, digestive system and renal tissue that is due to its epitheliotropic nature. This is the first pathogenicity study of Iranian variant-2 virus. Based on histology observations and clinical signs this isolate was classified as a nephropathogenic IBV. Further knowledge of IBV pathogenesis permits to perform more effective prevention practice.

Effect of enamel surface treatment on the bond strength of metallic brackets in rebonding process.

Bond failure after rebonding for newly placed brackets can be reduced by appropriate enamel surface treatment. This in vitro study investigated the effect of two enamel surface treatments on the bond strength of metallic brackets in the rebonding process. After debonding the brackets and removing the residual adhesive on the enamel surface of 50 upper premolar teeth, the teeth were divided into two equal groups. In the first group, the enamel surface was etched with phosphoric acid 37 per cent, and in the second group, the teeth were sandblasted prior to acid etching. After bonding of the new brackets, the shear bond strength (SBS), probability of bond failures, and adhesive remnant index (ARI) were determined and compared with the t-test, Weibull analysis, and chi-square test. Mean SBS in both groups did not differ significantly (P = 0.081). Most bond failures occurred with ARI scores of 2 and 3, and the difference between the two groups was statistically significant (P < 0.001). Weibull analysis showed that for a given stress, the probability of failure differed between groups. Enamel surface preparation with sandblasting prior to acid etching did not significantly improve SBS in bracket rebonding and left more residual adhesive remnants on the enamel surface.

Diagnosis of poult enteritis complex (PEC) and molecular detection of avian coronaviruses in some commercial turkey flocks in Iran.

BACKGROUND: Enteritis syndromes, also known as poult enteritis complex (PEC) with diverse etiologies, can affect turkey production. An avian coronavirus (AvCoV), turkey coronavirus (TCoV), is one of the most important viral causes of PEC in turkeys. AIMS: In the present study, the occurrence of PEC and the presence of AvCoV in some commercial turkey flocks were investigated. METHODS: PEC was diagnosed based on the history, clinical, and necropsy findings. A reverse transcriptase-polymerase chain reaction (RT-PCR) targeting the AvCoV nucleoprotein (N) gene was applied to detect the virus in the tissue samples. Cloacal swabs were collected from 11 flocks without a known history of PEC. RESULTS: PEC was diagnosed in six (16.2%) out of 37 investigated turkey flocks. The daily mortality rate in affected flocks ranged from 0.2 to 1.2%. Samples from 8 flocks out of 18 (44.4%) were positive for AvCoV. Four PEC affected flocks were positive for AvCoV. Seven positive samples were sequenced and phylogenetic analysis revealed the close relationship with previously characterized avian infectious bronchitis viruses (IBV). CONCLUSION: The results suggested that PEC should be considered as a significant syndrome in the Iranian turkey industry. According to this preliminary study, it was shown that avian coronavirus infection is prevalent in commercial turkey farms of Iran. However, no causative association could be concluded between PEC occurrence and AvCoV infection in turkey flocks.

Molecular detection of fowl adenovirus 7 from slaughtered broiler chickens in Iran: the first report.

BACKGROUND: Fowl adenoviruses (FAdVs) are responsible for a variety of clinical symptoms, with an increasing significance in the poultry industry throughout the world. Typical diseases caused by FAdVs include inclusion body hepatitis (IBH), hepatitis-hydropericardium syndrome (HHS), gizzard erosion (GE), respiratory disease, and hemorrhage in muscles and organs. AIMS: During 2020, broiler chickens from the north of Iran showed ecchymotic and petechial hemorrhages in thigh and breast muscles at the slaughterhouse. Hemorrhages were observed in 10% to 60% (with an average of 20-30%) of chicks per flock. To find out the etiology of these lesions, the present study was conducted. METHODS: Different environmental factors were investigated, and FAdV, infectious bursal disease virus (IBDV), and chicken infectious anemia virus (CIAV) were detected using molecular assays. RESULTS: Among the viruses tested, FAdV was detected by polymerase chain reaction (PCR), and sequence analysis clustered the virus into species E, serotype 7. CONCLUSION: This is the first report on FAdV-7 existence among poultry in Iran. Effective screening of the chicks at slaughtering age should be performed from the whole country.

The emergence of Q1 genotype of avian infectious bronchitis virus in Iran, 2019: the first report.

BACKGROUND: Avian infectious bronchitis (IB) is an infectious viral disease of chickens. The effective protection of chickens against many different infectious bronchitis virus (IBV) variants is not achieved unless the circulating genotypes in the region are identified and the cross-protection of the potential of vaccines in use is assessed. AIMS: In a monitoring program of IBVs, a new genotype was identified in the north of Iran, 2019. This work was conducted to isolate and characterize this new IBV genotype. METHODS: Tracheal tissues were collected from chickens showing signs of respiratory involvement. Specimens were homogenized and inoculated to the allantoic fluid of embryonated specific pathogen-free (SPF) eggs. Infectious bronchitis virus was detected using real time-polymerase chain reaction (RT-PCR). The hypervariable region of the IBV S1 gene was amplified for sequencing. RESULTS: Positive samples were phylogenetically analyzed, and both positive isolates were clustered with Q1 IBV strains. CONCLUSION: This is the first report of the Q1 outbreak in Iran. More investigations are needed to find the role of Q1 IBV in the respiratory disease complex of chickens.

Molecular Detection of Gamma Coronaviruses in Bird Parks of Iran.

Gamma Coronaviruses (GCoVs) are distributed worldwide, affecting a wide range of bird species, the beluga whale, and bottlenose dolphins. Because of the limited proofreading capability in the viral encoded polymerase, they emerge genetically diverse. There has been no molecular surveillance data to describe the epidemiology of GCOVs in avian species. The present study was conducted to detect GCOVs in Tehran birds&rsquo; parks, 2015. Cloacal swabs (267 samples) from eight different bird species ((Chickens (Gallus gallus), Pheasant (Phasianus colchicus), Turkey (Meleagris gallopavo), Partridge (Perdix perdix), Quail (Coturnix coturnix), Duck (Anas platyrhynchos), Goose (Anserini),and Guinea fowl (Numididae)) were collected, the viral RNA was extracted, the RT-PCR was performed using QIAGEN one step RT-PCR kit and the primers targeting &ldquo;3&#39;-UTR&rdquo; and &ldquo;Nucleocapsid&rdquo; genes. The detection rate was approximately 8.99%. GCOVs were detected in the chicken, quail, pheasant, turkey, and the partridge with different prevalence rates. Phylogenetic tree based on partial nucleotide sequences of the N gene clustered the samples into two groups. It is the first report of GCOVs in non-commercial birds in Iran. According to our results, GCOVs are circulating in different avian species, and further studies are needed to isolate these viruses and evaluate their pathogenesis.

Lung function reference values in Iranian adolescents.

There is insufficient information about reference values for pulmonary volumes for Iranian populations. A study of lung function parameters was made on 302 non-smoking healthy Iranian students (152 male and 150 female). Lung function measures correlated strongly with height but not with body mass index. There were significant differences between some of the measured parameters and American Thoracic Society reference values for Caucasians (P < 0.05). Of note is the high functional residual capacity (110% higher) and low inspirational capacity (86% lower) in males compared with the reference values.

Physalis alkekengi and Alhagi maurorum ameliorate the side effect of cisplatin-induced nephrotoxicity.

Cisplatin is frequently being used for the treatment of different tumors, although the application of this agent is associated with nephrotoxicity. Here, we explored the antioxidant and anti-inflammatory activities of Physalis alkekengi and Alhagi maurorum; 400 mg kg(-1) per day P. alkekengi and 100 mg kg(-1) per day A. maurorum were administered in rats, orally for 10 days after a single dose of 7 mg kg(-1) intraperitoneal cisplatin. The concentrations of creatinine, urea-nitrogen, and relative and absolute excretion of sodium/potassium were evaluated before/after therapy. Levels of malondialdehyde (MDA) and ferric-reducing antioxidant power (FRAP) were measured to assess the oxidative stress induced by cisplatin. Moreover, tissues sections were used for histological analyses and evaluation of the degree of tissue damage. Cisplatin increased serum levels of creatinine and urea-nitrogen, relative/absolute excretion of sodium/potassium, and MDA, whereas decreased FRAP level. Interestingly, P. alkekengi or A. maurorum were able to reduce the level of the renal function markers as well as the levels of sodium/potassium. This effect was more pronounced by P. alkekengi. Moreover, cisplatin induced pathological damage in kidney, whereas treatment with these agents improved this condition. Our findings demonstrate the potential therapeutic impact of P. alkekengi and A. maurorum for improving cisplatin-induced nephrotoxicity, supporting further investigations on the novel potential clinical application of these agents for patients being treated with cisplatin to ameliorate cisplatin-induced nephrotoxicity.

Selective activation of Ca2+ influx by extracellular ATP in a pancreatic beta-cell line (HIT).

The action of exogenous ATP on cytoplasmic free Ca2+ ([Ca2+]i) was studied in insulin secreting cells using fura-2. Stimulation of clonal pancreatic beta-cells (HIT) with ATP (range 2-20 microM) evoked a sustained elevation in [Ca2+]i. ATP selectively promoted Ca2+ influx and not Ca2+ mobilization since (1) the effect required external Ca1+ and (2) was observed in cells in which internal stores were depleted with ionomycin (3) the rate of Mn2+ influx, measured as the quenching of the fura-2 signal, was accelerated by ATP. The action of ATP was unaffected by the voltage-sensitive Ca2+ channel blockers nifedipine and verapamil as well as by a depolarizing concentration of K+. The effect on [Ca2+]i was highly specific for ATP since AMP, ADP, adenosine 5'-[gamma-thio]triphosphate, adenosine 5'-[beta, gamma-methylene]triphosphate, GTP and adenosine were ineffective. In normal pancreatic islet cells, both exogenous ATP (range 0.2-2 microM) and ADP induced a transient Ca2+ elevation that did not require external Ca2+. The nucleotide specificity of the effect on [Ca2+]i suggests that ATP activates P2 gamma purinergic receptors in normal beta-cells. Thus, ATP evokes a Ca2+ signal in clonal HIT cells and normal islet cells by different transducing systems involving distinct purinoreceptors. A novel mechanism for increasing [Ca2+]i by extracellular ATP is reported in HIT cells, since the nucleotide specificity and the selective activation of Ca2+ influx without mobilization of internal Ca2+ stores cannot be explained by mechanisms already described in other cell systems.

Glucose transport by radiation-induced insulinoma and clonal pancreatic beta-cells.

Sugar uptake was measured in dispersed cells prepared from radiation-induced insulinomas transplantable in NEDH rats and in three clonal beta-cell lines maintained in continuous culture (RIN m5F, RIN 1046, HIT). Uptake of D-glucose and 3-O-methyl-D-glucose by insulinoma cells was rapid so that the intracellular concentration of D-hexoses approximated the concentration in the incubation medium by 15-30 s. L-Glucose was taken up only slowly. 3-O-methyl-D-glucose uptake by RIN m5F, RIN 1046, and HIT cells was slow; with 1 mM 3-O-methylglucose in the medium, equilibrium was attained at 20 min, but with 10 mM 3-O-methylglucose, equilibrium was not attained even at 20 min. In HIT cells incubated with D-glucose for 30 min, the intracellular concentration of glucose was less than the medium glucose concentration, indicating glucose transport is a nonequilibrium reaction in this cell line. These data indicate that radiation-induced insulinoma cells retain the capacity of normal beta-cells to transport sugar at high rates. RIN m5F, RIN 1046, and HIT cells transport sugar slowly, however, and thus differ from normal beta-cells. In RIN m5F, RIN 1046, and HIT cells, unlike in normal beta-cells, glucose transport may be the site regulating glucose metabolism.

Control of glucose metabolism in pancreatic beta-cells by glucokinase, hexokinase, and phosphofructokinase. Model study with cell lines derived from beta-cells.

Glucose usage by soluble fractions of cell extracts from two insulin-producing cell lines, RINm5F and HIT, was investigated. Analysis of enzyme activities indicated that glucose phosphorylation and phosphofructokinase are likely to be the rate-limiting steps of glycolysis in both RINm5F and HIT cell extracts. RINm5F extracts, which lack glucokinase, exhibited relatively flat concentration-dependency curves of glucose usage and showed substantial inhibition of hexokinase. HIT cell extracts, which contain glucokinase but lack hexokinase, exhibited sigmoidal concentration-dependency curves of glucose usage, reflecting almost fully expressed glucokinase activity. A reconstituted system prepared from RINm5F and HIT cell extracts exhibited a composite concentration-dependency curve of glucose usage and showed substantial inhibition of hexokinase and almost fully expressed glucokinase. However, conditions that activate phosphofructokinase, such as addition of ammonium sulfate or fructose 2,6-bisphosphate or alkalization, removed the inhibition of hexokinase without noticeably affecting the glucokinase component of usage. Results obtained with a reconstituted system containing RINm5F cell extract and purified glucokinase were consistent with these findings. The data presented here indicate that this reconstituted cell-free system serves as a valid model for the study of aspects of glycolytic control in the islet. This model illustrates the preeminent role of glucokinase in the control of glycolysis, consistent with its glucose-sensor function in the islet. In addition, these studies help to define the contribution of phosphofructokinase to the control of glycolysis and the mechanism whereby changes in phosphofructokinase activity could modulate, via changes in the glucose 6-phosphate concentration, the activity of hexokinase and hence the net glycolytic flux.

Fuel-stimulated insulin secretion by clonal hamster beta-cell line HIT T-15.

Insulin secretion by monolayer cultures of HIT T-15 cells was measured in response to various fuel molecules (glucose, dihydroxyacetone, lactate, glutamine, alpha-ketoisocaproic acid, alpha-ketoisovaleric acid) and a nonmetabolized glucose analogue (3-O-methylglucose). HIT cells secreted insulin in response to fuel molecules, but 3-O-methylglucose was ineffective. Stimulation of insulin release by fuels was increased by isobutylmethylxanthine and blocked by antimycin A. Iodoacetate selectively inhibited glucose-stimulated insulin release but had little effect on alpha-ketoisocaproic acid-stimulated insulin secretion. These results indicate that HIT cells retain the capacity of normal beta-cells to act as fuel sensors. Thus, HIT cells may provide a well-defined and relatively abundant tissue source in studies of stimulus-secretion coupling in beta-cells stimulated by fuels.

Regulatory role of fructose-2,6-bisphosphate in pancreatic islet glucose metabolism remains unsettled.

Fructose-2,6-P2 was measured in perifused, isolated rat pancreatic islets. Fructose-2,6-P2 was present in pancreatic islets at low levels approximately equal to fructose-2,6-P2 content of liver from fasted rats. In islets perifused with glucose at physiologic concentrations, fructose-2,6-P2 was increased from 0.8 microM in the presence of 5.5 mM glucose to 1.0 microM at 10 mM glucose and 1.3 microM at 16.7 mM glucose, but did not increase further at higher glucose concentration. Therefore, only modest increases in the phosphofructokinase-1 activator, fructose-2,6-P2, occur at glucose concentrations stimulating insulin secretion.

Identification of glucokinase as an alloxan-sensitive glucose sensor of the pancreatic beta-cell.

Alloxan inactivated glucokinase in intact, isolated pancreatic islets incubated in vitro. Inactivation of glucokinase was antagonized by 30 mM glucose present during incubation of islets with alloxan. Glucokinase partially purified from transplantable insulinomas or rat liver was inactivated by alloxan with a half-maximal effect at 2-4 microM alloxan. Inactivation of purified glucokinase was antagonized by glucose, mannose, and 2-deoxyglucose in order of decreasing potency but not by 3-O-methylglucose. Glucose anomers at 6 and 14 mM were discriminated as protecting agents, with the alpha-anomer more effective than the beta-anomer. Glucokinase was not protected from alloxan inactivation by N-acetylglucosamine, indicating that the reactive site for alloxan is not the active site; therefore, glucose may protect glucokinase by inducing a conformational change. Glucokinase is thought to be the glucose sensor of the pancreatic beta-cell. The finding that glucokinase is inactivated by alloxan and protected by glucose with discrimination of its anomers similar to inhibition of glucose-stimulated insulin secretion by alloxan supports this hypothesis and appears to explain the mechanism for inhibition of hexose-stimulated insulin secretion by this agent and the unique role of glucose and mannose as protecting agents.

Glucose regulation of glutaminolysis and its role in insulin secretion.

Leucine or the nonmetabolized leucine analog +/- 2-amino-2-norbornane-carboxylic acid (BCH) (both at 10 mmol/l) induced biphasic insulin secretion in the presence of 2 mmol/l glutamine (Q2) in cultured mouse islets pretreated for 40 min without glucose but with Q2 present. The beta-cell response consisted of an initial peak of 20- to 25-fold above basal and a less marked secondary phase. However, BCH produced only a delayed response, while leucine was totally ineffective when islets were pretreated with 25 mmol/l glucose plus Q2. With Q2, 10 mmol/l BCH or leucine caused a nearly threefold increase, a twofold increase, or had no effect on cytosolic Ca2+ levels in islets pretreated for 40 min with 0, 5, or 15 mmol/l glucose, respectively. Thus, pretreatment of islets with high glucose inhibited BCH- and leucine-induced cytosolic Ca2+ changes and insulin release. Glucose decreased glutamine oxidation in cultured rat islets when BCH was present at 10 mmol/l, but not in its absence, with a lowest effective level of approximately 0.1 mmol/l, a maximum of 18-30 mmol/l, and an inhibitory concentration, 50%, of approximately 3 mmol/l. The data are consistent with the hypothesis that glucose inhibits glutaminolysis in pancreatic beta-cells in a concentration-dependent manner and hence blocks leucine-stimulated insulin secretion. We postulate that in the basal interprandial state, glutaminolysis of beta-cells is partly turned on because glutamate dehydrogenase (GDH) is activated by a decreased P-potential due to partial fuel depletion and sensitization to endogenous activators such as leucine. Additionally, it may contribute significantly to basal insulin release, which is known to be responsible for about half of the insulin released daily. The data explain "leucine-hypersensitivity" of beta-cells during hypoglycemia and contribute to the elucidation of the GDH-linked syndrome of hyperinsulinism associated with elevated serum ammonia levels. Thus, understanding the precise regulation and role of beta-cell glutaminolysis is probably central to our concept of normal blood glucose control.

Effects of glucose on insulin secretion, glucokinase activity, and transgene expression in transgenic mouse islets containing an upstream glucokinase promoter-human growth hormone fusion gene.

We have analyzed in organ culture the effects of glucose on glucose-induced insulin secretion, glucokinase (GK) activity, and human growth hormone (hGH) expression in pancreatic islets from transgenic mice containing an upstream GK promoter-hGH fusion gene. Freshly isolated islets from these mice had a normal insulin secretory response to glucose but showed subtle defects after culture in low or high glucose for 4 days that may have been due to the accumulation of hGH in the culture media. Islets cultured from both normal and transgenic mice had approximately a fourfold induction of GK activity in response to an increased concentration of glucose in the culture media, whereas no such change in total islet hGH production was observed. Immunocytochemical localization of hGH in islets cultured in 3 mM glucose showed a pattern similar to that in freshly isolated islets. However, after culture in 30 mM glucose, hGH immunostaining became strikingly more heterogeneous. We conclude 1) that GK-hGH transgene expression does not appear to adversely affect glucose-stimulated insulin secretion in vivo or in freshly isolated islets, 2) that glucose does not induce transgene expression, thus providing additional evidence against an effect of glucose on GK gene transcription in the islet, and 3) that glucose stimulates the co-release of hGH with insulin, thereby enhancing the heterogeneous staining pattern seen among pancreatic beta-cells.

Concordant glucose induction of glucokinase, glucose usage, and glucose-stimulated insulin release in pancreatic islets maintained in organ culture.

Using cultured islets as the experimental system, this study established dosage-response and time-dependency curves of the inductive glucose effect on glucose-stimulated insulin release, glucose usage, and glucokinase activity. Glucose-stimulated insulin release in islets cultured for 1, 2, or 7 days was increased as a function of glucose concentration in the culture medium and as a function of time. Glucose usage in the cultured islets showed a close relationship with glucose concentration in the culture medium at both 2 and 7 days of culture. Glucokinase activity increased in islets cultured for 1, 2, or 7 days as a function of increasing glucose concentrations in the culture medium and as a function of time. The V(max) of glucokinase in islets cultured for 7 days in medium containing 30 mM glucose was twice the value of freshly isolated islets and was almost fivefold higher than that in islets cultured for 7 days in 3 mM glucose. The glucose induction of glucose-stimulated insulin release, of glucose usage, and of glucokinase activity were tightly correlated. The biochemical mechanisms of glucose induction of islet glucokinase were further studied. Immunoblotting with an antibody against C-terminal peptide of glucokinase showed that densities of a 52,000-kD protein band from tissue extracts of islets cultured for 7 days in 3, 12, and 30 mM glucose were 25, 44, and 270% compared with that of extract from freshly isolated islets (100%). RNA blot analysis of glucokinase mRNA demonstrated virtually the same levels in fresh islets and islets after 7 days of culture in 3 or 30 mM glucose. The adaptive response of glucokinase to glucose appears therefore to be occurring at a translational or posttranslational site in cultured islets. These data greatly strengthen the concept that glucose is the regulator that induces the activity of glucokinase, which in turn determines the rate change of glucose usage as well as glucose-stimulated insulin release from beta-cells. Thus, the hypothesis that glucokinase is the glucose sensor of beta-cells is strengthened further.

Diaphragmatic left ventricular aneurysm. Clinical features, surgical treatment, and long-term follow-up in 22 patients.

Although the formation of a left ventricular aneurysm (LVA) is a common and well-recognized complication of myocardial infarction (MI), diaphragmatic LVA is a rare clinical entity. Of 354 consecutive patients who underwent LVA resection, we describe the clinical features and surgical results of 22 patients (6%) with diaphragmatic LVA. All patients had a history of MI. The principal clinical indication for surgery was heart failure in nine patients, angina pectoris in ten patients, and recurrent ventricular tachycardia unresponsive to medical therapy in three patients. A ventricular septal defect was present in two patients, and moderate to severe mitral regurgitation was present in four patients. Three of the four surgical deaths (operative mortality, 18%) occurred in patients with mitral regurgitation or with ventricular septal defect. Eleven patients are alive at a mean follow-up of 40 months. Six of them are asymptomatic and two have angina at a higher level of physical activity than before surgery. Notable differences exist in the clinical presentation and surgical findings between patients with diaphragmatic and anterior LVA.

Mitral valve replacement through the aortic root.

This report discusses the case histories of two patients who had had previous cardiac operations and required extensive reoperations including mitral valve replacement. In both patients the replacement of the mitral valve was performed through the aortic root. This rare approach to the mitral valve, conducted with remarkable facility in these patients, encourages more liberal use of transaortic mitral valve operations in selected patients.

Coronary artery bypass surgery in patients less than 40 years of age.

Coronary bypass patients less than 40 years of age were identified and compared with a control group previously studied at our hospital. In patients less than 40 years, the average age was 35 years. Men comprised 90.1 percent of group 1, and 83.4 percent of group 2. Operative mortality was 2.89 percent for group 1 and 2.1 percent for group 2. Patients less than 40 years were more likely to have positive family history (46.3 percent vs 21.94 percent), elevated cholesterol levels (25.62 vs 11.36 percent), and be smokers (59.09 vs 39.9 percent). Group 1 patients were less likely to have diabetes (4.54 vs 13.37 percent) or hypertension (18.18 vs 31.43 percent). The percentage of late deaths was much higher for younger patients. Postoperative angina and the need for reoperation was higher in group 1.