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1.
Iran J Vet Res ; 22(3): 244-247, 2021.
Article in English | MEDLINE | ID: mdl-34777527

ABSTRACT

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.

2.
Iran J Vet Res ; 22(4): 342-346, 2021.
Article in English | MEDLINE | ID: mdl-35126543

ABSTRACT

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.

3.
Iran J Vet Res ; 21(3): 230-233, 2020.
Article in English | MEDLINE | ID: mdl-33178303

ABSTRACT

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.

4.
Arch Razi Inst ; 74(4): 349-355, 2019 12.
Article in English | MEDLINE | ID: mdl-31939251

ABSTRACT

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’ 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 “3'-UTR” and “Nucleocapsid” 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.


Subject(s)
Anseriformes , Bird Diseases/epidemiology , Coronavirus Infections/veterinary , Galliformes , Gammacoronavirus/isolation & purification , Animals , Animals, Zoo , Bird Diseases/virology , Coronavirus Infections/epidemiology , Coronavirus Infections/virology , Iran/epidemiology , Phylogeny , Prevalence
5.
Acta Virol ; 60(4): 393-399, 2016.
Article in English | MEDLINE | ID: mdl-27928919

ABSTRACT

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.


Subject(s)
Coronavirus Infections/veterinary , Infectious bronchitis virus/pathogenicity , Poultry Diseases/virology , Animals , Chickens , Coronavirus Infections/pathology , Coronavirus Infections/virology , Female , Infectious bronchitis virus/genetics , Infectious bronchitis virus/physiology , Iran , Male , Poultry Diseases/pathology , Specific Pathogen-Free Organisms , Virulence
6.
Cancer Gene Ther ; 23(7): 235-40, 2016 07.
Article in English | MEDLINE | ID: mdl-27255563

ABSTRACT

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.


Subject(s)
Antineoplastic Agents/toxicity , Antioxidants/administration & dosage , Cisplatin/toxicity , Plant Extracts/administration & dosage , Renal Insufficiency/chemically induced , Administration, Oral , Animals , Drug Evaluation, Preclinical , Fabaceae/chemistry , Kidney Tubules, Proximal/drug effects , Kidney Tubules, Proximal/pathology , Male , Oxidative Stress/drug effects , Physalis/chemistry , Rats, Sprague-Dawley , Renal Insufficiency/prevention & control
7.
Photomed Laser Surg ; 31(8): 360-4, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23865860

ABSTRACT

OBJECTIVE: The purpose of this study was to compare the bond strength of orthodontic brackets using laser versus acid etching. BACKGROUND DATA: Debonding of brackets is a common problem in orthodontic treatments. MATERIALS AND METHODS: Eighty extracted premolar teeth were divided into two groups. The enamel of the teeth in group A and B were etched using CO2 laser and phosphoric acid, respectively. The brackets were bonded to the teeth using Transbond XT and then debonded from the teeth by Instron machine. The remaining composite on the tooth surface was removed by a tungsten carbide polishing bur. Both groups were divided into two subgroups (A1, A2 and B1, B2). The teeth were prepared again with laser in A1, B1 subgroups and with acid in A2, B2 subgroups. At each stage, the shear bond strength and residual adhesive index were measured. One way ANOVA and χ(2) tests were used to analyze data. RESULTS: The mean shear bond strength was significantly lower in group A and higher in group B compared with all other groups (p < 0.05). Most of the bond failures were degree 0 and 1 in groups A, A1, and B1, and degree 2 and 3 in groups B, A2, and B2. CONCLUSIONS: Primary preparation with acid has a higher bond strength value than does CO2 laser. Less adhesive residue remained on enamel after tooth preparation with laser following debonding. Secondary preparation of the enamel using laser has higher bond strength value than does primary preparation with laser, which can rationalize use of laser in rebonding of brackets.


Subject(s)
Dental Bonding/methods , Dental Etching , Lasers, Gas , Orthodontic Brackets , Shear Strength , Acid Etching, Dental , Humans , Resin Cements/therapeutic use
8.
Eur J Orthod ; 34(6): 773-7, 2012 Dec.
Article in English | MEDLINE | ID: mdl-21911841

ABSTRACT

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.


Subject(s)
Acid Etching, Dental/methods , Dental Bonding/methods , Dental Enamel , Orthodontic Brackets , Shear Strength , Adhesiveness/drug effects , Adolescent , Adult , Bicuspid , Chi-Square Distribution , Dental Bonding/standards , Dental Enamel/drug effects , Dental Stress Analysis/methods , Hardness Tests , Humans , Phosphoric Acids/chemistry , Resin Cements/chemistry , Retreatment/methods , Young Adult
9.
Eur J Esthet Dent ; 5(4): 370-80, 2010.
Article in English | MEDLINE | ID: mdl-21069108

ABSTRACT

INTRODUCTION: an attractive smile helps people feel more self-confident and look younger. One of the more controversial aspects of smile attractiveness pertains to buccal corridor size. There is no previous study by those with artistic knowledge that has assessed the asthetic considerations of buccal corridor size. The purpose of this study was to observe whether the size of buccal corridors has an impact on smile attractiveness evaluated by lay people, dental students, and art students. MATERIALS AND METHODS: colored post-treatment photograph with posed smiles of two subjects (one male, one female) were selected. The maxillary posterior dentitions were digitally altered to produce different buccal corridor sizes: narrow (28% buccal corridor), medium-narrow (22% buccal corridor), medium-broad (10% buccal corridor), and broad (2% buccal corridor). The 5 images of each subject were paired into 11 possible combinations and presented to three group: art students, dental students, and lay people, who compared the two images in each pair of smile attractiveness. The statistical test used were Wilcoxon signed rank and Mann-Whitney test. RESULTS: minimal and excessive buccal corridors were the least attractive when judged by three groups. All groups preferred smaller buccal corridors for the male subject and larger buccal corridors for the female subject. No significant judging differences were found between male and female judges from among art and dental students. CONCLUSIONS: minimal or excessive buccal corridor should be included in the problem list during orthodontic diagnosis and treatment planning.


Subject(s)
Cheek/anatomy & histology , Esthetics, Dental , Lip/anatomy & histology , Smiling/physiology , Adolescent , Adult , Art , Attitude to Health , Cross-Sectional Studies , Dental Arch/anatomy & histology , Female , Humans , Male , Mandible/anatomy & histology , Maxilla/anatomy & histology , Photography, Dental , Sex Factors , Students , Students, Dental , Young Adult
11.
East Mediterr Health J ; 12(6): 834-9, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17333830

ABSTRACT

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.


Subject(s)
Adolescent/physiology , Lung Volume Measurements , Anthropometry , Arabs/ethnology , Arabs/genetics , Arabs/statistics & numerical data , Body Height , Body Mass Index , Female , Forced Expiratory Flow Rates/physiology , Functional Residual Capacity/physiology , Humans , Inspiratory Reserve Volume/physiology , Iran , Linear Models , Lung Volume Measurements/instrumentation , Male , Plethysmography/instrumentation , Reference Values , Residual Volume/physiology , Sex Characteristics , Thorax/anatomy & histology , Tidal Volume/physiology , Urban Population/statistics & numerical data , Vital Capacity/physiology , White People/ethnology , White People/genetics , White People/statistics & numerical data
12.
(East. Mediterr. health j).
in English | WHO IRIS | ID: who-117160

ABSTRACT

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


Subject(s)
Respiratory Function Tests , Adolescent , Body Height , Reference Values , Observer Variation
13.
Biochem Soc Trans ; 33(Pt 1): 306-10, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15667334

ABSTRACT

The enzyme GK (glucokinase), which phosphorylates glucose to form glucose 6-phosphate, serves as the glucose sensor of insulin-producing beta-cells. GK has thermodynamic, kinetic, regulatory and molecular genetic characteristics that are ideal for its glucose sensor function and allow it to control glycolytic flux of the beta-cells as indicated by control-, elasticity- and response-coefficients close to or larger than 1.0. GK operates in tandem with the K(+) and Ca(2+) channels of the beta-cell membrane, resulting in a threshold for glucose-stimulated insulin release of approx. 5 mM, which is the set point of glucose homoeostasis for most laboratory animals and humans. Point mutations of GK cause 'glucokinase disease' in humans, which includes hypo- and hyper-glycaemia syndromes resulting from activating or inactivating mutations respectively. GK is allosterically activated by pharmacological agents (called GK activators), which lower blood glucose in normal animals and animal models of T2DM. On the basis of crystallographic studies that identified a ligand-free 'super-open' and a liganded closed structure of GK, on thermostability studies using glucose or mannoheptulose as ligands and studies showing that mannoheptulose alone or combined with GK activators induces expression of GK in pancreatic islets and partially preserves insulin secretory competency, a new hypothesis was developed that GK may function as a metabolic switch per se without involvement of enhanced glucose metabolism. Current research has the goal to find molecular targets of this putative 'GK-switch'. The case of GK research illustrates how basic science may culminate in therapeutic advances of human medicine.


Subject(s)
Glucokinase/metabolism , Glucose/metabolism , Homeostasis , Crystallography, X-Ray , Glucokinase/antagonists & inhibitors , Glucokinase/chemistry , Glucokinase/genetics , Humans , Hypoglycemic Agents/pharmacology , Kinetics , Point Mutation , Protein Conformation
15.
Diabetes ; 48(8): 1535-42, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10426370

ABSTRACT

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.


Subject(s)
Amino Acids, Cyclic , Glucose/pharmacology , Glutamine/metabolism , Insulin/metabolism , Islets of Langerhans/drug effects , Islets of Langerhans/metabolism , Amino Acids/pharmacology , Animals , Calcium/metabolism , Culture Techniques , Cytosol/metabolism , Dose-Response Relationship, Drug , Glycolysis/physiology , Insulin Secretion , Leucine/pharmacology , Mice , Oxidation-Reduction , Rats
16.
Ann Thorac Surg ; 67(1): 241-4, 1999 Jan.
Article in English | MEDLINE | ID: mdl-10086563

ABSTRACT

A 53-year-year-old man presented with aortic regurgitation, subvalvular and supravalvular aortic stenoses, and aneurysms involving the ascending aorta, the arch, and the innominate, right subclavian, and left common carotid arteries. Surgery consisted of resection of the obstructive lesions, replacement of the aortic valve, graft replacement of the ascending aorta, and the arch resection of innominate and subclavian artery aneurysms and reconstruction with a side limb to which the right carotid artery was anastomosed. The patient has remained asymptomatic with full employment.


Subject(s)
Heart Diseases/surgery , Aneurysm/complications , Aneurysm/surgery , Aortic Aneurysm/complications , Aortic Aneurysm/surgery , Aortic Valve Insufficiency/complications , Aortic Valve Insufficiency/surgery , Aortic Valve Stenosis/complications , Aortic Valve Stenosis/surgery , Carotid Arteries , Humans , Male , Middle Aged , Subclavian Artery
17.
Ann Thorac Surg ; 66(2): 493-9, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9725391

ABSTRACT

BACKGROUND: Various techniques have been used for cerebral protection in aortic arch operations. Antegrade cerebral perfusion has lost its popularity to hypothermic circulatory arrest to overcome the so-called cluttered operative field. Hypothermic circulatory arrest has its own problems of coagulopathy, time constraints, and prolongation of cardiopulmonary bypass time. METHODS: Since June 1986 we have used antegrade bihemispheric cerebral perfusion with moderate hypothermia in 20 patients with aortic arch disease. Twelve patients had aneurysm, 7 had dissection, and 1 had traumatic tear. Five patients had had previous sternotomy for ascending aortic replacement. In addition to arch reconstruction, 7 patients had aortic valve replacement or repair, 2 patients had Bentall procedure, and 3 had selective innominate reconstruction. The mean cerebral perfusion time was 51+/-29 minutes. In 7 patients the cerebral perfusion time was between 60 and 120 minutes. RESULTS: There was no in-hospital or 30-day mortality. The blood product requirements were significantly less with moderate hypothermia. One patient suffered cerebrovascular accident (5%). None of the 7 patients with cerebral perfusion times of 60 to 120 minutes had any neurologic deficits. These results are superior to those reported for hypothermic circulatory arrest with or without retrograde cerebral perfusion. CONCLUSIONS: Antegrade bihemispheric cerebral perfusion is an optimal adjunct for cerebral protection during aortic arch operations.


Subject(s)
Aorta, Thoracic/surgery , Cerebrovascular Circulation/physiology , Perfusion/methods , Adolescent , Adult , Aged , Aged, 80 and over , Aortic Dissection/surgery , Aortic Aneurysm, Thoracic/surgery , Cerebrovascular Disorders/etiology , Female , Humans , Hypothermia, Induced , Male , Middle Aged , Postoperative Complications , Time Factors
18.
Swiss Surg ; 4(3): 118-20, 1998.
Article in English | MEDLINE | ID: mdl-9655005

ABSTRACT

Combined replacement of the aortic and mitral values is a relatively common operation. Occasionally it is feasible to replace the mitral value through the aortic root. This remarkable approach eliminates the need for a second atrial incision, and in reoperation it avoids extensive dissection and release of adhesions. Injury to the heart is minimized and the incidence of perioperative bleeding is reduced. The exposure is excellent and the operation is performed safely and expeditiously.


Subject(s)
Aorta/surgery , Aortic Valve/surgery , Heart Valve Prosthesis Implantation/methods , Mitral Valve/surgery , Aged , Aortic Aneurysm, Thoracic/surgery , Heart Valve Prosthesis , Humans , Male , Prosthesis Failure , Reoperation , Treatment Outcome
19.
Ann Thorac Surg ; 64(2): 565-7, 1997 Aug.
Article in English | MEDLINE | ID: mdl-9262624

ABSTRACT

On three occasions during operations for aortic aneurysm involving the ascending aorta it was noted that upon the release of the aortic clamp the grafted segment remained collapsed, indicating very little or no flow reaching the lumen of the reconstructed aorta. This was promptly and successfully remedied in 2 patients by perfusing the graft directly with a pediatric arterial catheter attached to a pump head while the femoral arterial line maintained systemic arterial inflow. This simple, safe, and highly effective technique adds to the surgeon's repertoire to manage yet another intriguing intraoperative development during thoracic aortic operations.


Subject(s)
Aorta, Thoracic/surgery , Aortic Aneurysm, Thoracic/surgery , Cardiopulmonary Bypass , Aged , Blood Flow Velocity , Blood Vessel Prosthesis , Constriction , Female , Humans , Intraoperative Complications/therapy , Male , Middle Aged
20.
Am J Physiol ; 272(4 Pt 1): E696-711, 1997 Apr.
Article in English | MEDLINE | ID: mdl-9142893

ABSTRACT

In the beta-cells of the pancreas, glucose phosphorylation carried out by glucokinase is the rate-controlling step in glycolysis, and the kinetic characteristics of glucokinase govern to a high degree the dose-response relationship between glucose and insulin release. Because glucose-6-phosphatase (G-6-Pase) opposes the action of glucokinase, it may have a regulatory role in the release of insulin in response to glucose if the enzyme is present in the beta-cells. A number of researchers have reported finding high levels of G-6-Pase in islets, but quantitation of its activity remains controversial, mainly because of difficulties in solubilizing a particulate enzyme. Therefore a method developed to measure functional glucose phosphorylation activity in intact brain was applied (Chi, M. M.-Y., M. E. Pusateri, J. G. Carter, B. J. Norris, D. B. McDougal, Jr., and O. H. Lowry. Anal. Biochem. 161: 508-513, 1987), and the rates of accumulation and disappearance of 2-deoxyglucose 6-phosphate (DG-6-P) in freshly harvested islets were determined as a measure of glucose cycling. Islets were incubated in the presence of 30 mM 2-deoxyglucose (DG) for 60 min, and subsequently the incubation medium was replaced with medium containing no DG, but instead high levels of mannoheptulose as a blocker of phosphorylation. The content of DG-6-P in the islets was measured at strategic times during the protocol. As predicted by a mathematical model, DG-6-P accumulated in the presence of DG and decayed after its washout. Both of these results are consistent with islets containing dephosphorylation activity for this substrate. The kinetic curves were fit using a mathematical model, and the maximal G-6-Pase activity was estimated to be 0.13 +/- 0.005 micromol x g(-1) x min(-1). However, when the physiological effect of this amount of G-6-Pase activity was assessed by use of a model of glycolysis, it was found that the impact on glucose cycling and usage was insignificant. It was concluded that normal islets do contain measurable activity for dephosphorylating glucose 6-phosphate but that this enzymatic reaction does not play a role in glucose metabolism and sensing by the normal beta-cell.


Subject(s)
Glucose-6-Phosphatase/metabolism , Islets of Langerhans/enzymology , Models, Biological , Saccharomyces cerevisiae Proteins , Animals , Computer Simulation , Deoxyglucose/pharmacology , Dose-Response Relationship, Drug , Glucose/pharmacology , Glucose-6-Phosphate/analogs & derivatives , Glucose-6-Phosphate/metabolism , Homeostasis , In Vitro Techniques , Male , Perfusion , Phosphoric Monoester Hydrolases/metabolism , Rats , Rats, Wistar
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