bluuebunny/crossref_metadata_2025 huggingface dataset:
Experience of application maxipimi at patients with a terminal stage chronic renal insufficiency at allotransplantation of a kidney
Authors: R.Z. Ismagilov , T.A. Bapiev , A.K. Zainalov , T.B. Shynybaev , T.I. Rahimbekov , A.N. Syzganov‘s
Published: January 2005

The analysis of infectious complications in patients after allotransplantation of a donor kidney. For the dynamic analysis of frequency of infection‐purulent complications, all patients were divided into 2 groups. The first, control group included 33 patients who were operated from 2000 to 2002 (men‐21, women‐12, adults‐28, children‐5). The second, basic group included 35 patients (men‐22 and women‐13, adult‐28, children‐7), after allotransplantations, which have transferred operation–transplantations of kidney with 2003 on 2004. In the first group purulent–septic complications were marked at 9 patients (27.2%), from them two (6%) have died of a sepsis on a background of antibacterial therapy (cephalosporini 3 generations). Duration of treatment made from 7 up to 15 days. In the second group in the postoperative period purulent – septic complications were marked at 5 of 35 patients (14,2%). All 35 patients in the second group after allotransplantation of a donor kidney carried out preventive antibacterial therapy maxipimi (cephalosporini IV generations) on dosage 1 gram 2 times per day in a combination with amykini intravenously during 7 days. Cases of development of sepsis in this group of patients were not observed. Thus, estimating the received results, it is possible to draw the conclusion, application of antibiotics of a wide spectrum (cephalosporini IV generations) the patient with a terminal stage chronic renal insufficiency after allotransplantation of a donor kidney were lowered with quantity of suppurations of postoperative wounds and occurrence of infectious complications on 13%.
Effective interventions with chlorhexidine gluconate (CHG) to decrease hemodialysis (HD) tunneled catheter‐related infections
Authors: Redman N. , Schweon S. , Tokars J. , Jahre J.
Published: January 2005

Purpose: 
Identify practices to reduce HD catheter access related bacteremias (ARB). Methods: Data was collected per the CDC Dialysis Surveillance Network protocol. ARB was defined as a patient with a positive blood culture with no apparent source other than the vascular access catheter. ARB's were calculated in events per 100 patient months with 3 cohorts. Cohort 1 was observed for 12 months, Cohort 2 for the subsequent 10 months, and Cohort 3 for the final 10 months. Cohort 1 had weekly transparent dressing changes, cleansing of the skin and 5 minute soaking of the connection lines with 10% povidone‐iodine (PI) solution, and HCW use of clean gloves and face shield without a mask. Cohort 2 changes consisted of thrice weekly gauze dressing changes, skin cleansing with ChloraPrep, a 2% CHG/70% isopropyl alcohol applicator, masks on the patients, adding a face mask to the shield, and application of 10% PI ointment to the exit site. Cohort 3 changes included weekly application of BioPatch (BioP), an antimicrobial dressing with CHG, sterile glove use, and replacing the PI line soaks with 4% CHG. Results: The catheter‐associated ARB rate per 100 patient months was 7.9 (17ARB/216 patient months) in Cohort 1, 8.6 (13/151) in Cohort 2, and 4.7 (5/107) in Cohort 3(p = 0.31 compared with Cohorts 1 and 2 combined). During the last 2 months, in Cohort 3, 9 catheter lumen cracks occurred, with one of the patients having a bacteremia. Conclusions: Addition of CHG line soaks and BioP reduced tunneled catheter infections, although this is not statistically significant. The increased number of catheter lumen cracks raises concern with the use of CHG line soaks. Further investigation with use of CHG line soaks and the BioP for decreasing ARB is needed.
Shunt surveillance and occlusion, an analysis of efficiency
Authors: Wijnen E
Published: January 2005

Introduction: 
Vascular access failure is one of the greatest sources of morbidity for chronic hemodialysis patients. Prophylactic and repeated measurement of access flow may be of importance in preventing clotting. The aim of the study was therefore to analyse the cost effectiveness of a shunt surveillance program, which reduces the appearance of occlusion of the vascular access. Methods: The number of vascular access interventions (surgery and radiology) in the period 2001 till 2003 (transonic measurement period, TMP; 63 patients) was compared with a reference period (RP, 1996 till 1998) during which no access flow was measured (58 patients). All measurements were done with Transonic® and interventions according to K/DOQI. Results: During the RP, 123 vascular access operations (0.71 per patient year) were performed because of occlusion, whereas in the TMP 58 vascular access operations (0.3 per patient year) were performed. During the TMP, 298 angiographic measurements were performed (1.6 per patient year) in the RP 177, (1.0 per patient year). In the TMP, 1652 access flow measurements were performed. In order to prevent one shunt occlusion, 21 access flow measurements had to be performed. Total costs in the TMP (summary of angiography, angiography and PTA, hospitalization days, and operation costs) are reduced with 31% compared to the RP; costs per patient year in RP: €2315. Costs per patient year in TMP: €1606. Conclusion: By means of a shunt surveillance program (based on access flow measurement), if necessary followed by angiography, it is possible to reduce the number of acute vascular access occlusions. Although a shunt surveillance program may take up a lot of time for the nursing staff, the beneficial effects, lower costs, and reduced morbidity for the patients outweigh this effort.
Retrospective analysis of adequacy of hemodialysis using the Cannon catheter (Arrow International)
Authors: DaVanzo W.J.
Published: January 2005

Currently there is no published data using the Cannon catheter. Our purpose was to confirm adequacy of hemodialysis using the Arrow Cannon catheter. This retrospective study used patients from one nephrology practice, utilizing two dialysis centers. All patients in a two year period meeting inclusion/exclusion criteria referred for tunneled catheter placement were included. All catheters were placed by interventional nephrologist using ultrasound for vein cannulation and fluoroscopy for placement confirmation. Pump speed (Qb), venous and arterial pressures, Kt/V, urea reduction ratio (URR), and dialysis prescriptions/adherence to the prescription were reviewed at baseline and monthly for six months. Catheter removal or six months were the study endpoints. Complications were evaluated from time of insertion throughout the study period. 38 patients were enrolled in the study. All patients were treated in the outpatient setting. Insertion outcome was successful in all 38 patients. The average dialysis prescription was approximately 400 ml/min, 3.7 hours, and 3 days a week. The mean average pump speed for all months evaluated exceeded the K/DOQI guideline of 300 ml/min. by 67.9–101.4 ml/min. The differences were significant with p < 0.01. The mean Kt/V and URR% data for each month evaluated exceeded the K/DOQI guideline values of 1.2 for Kt/V and 63% for URR% by between .34–.24 and 8%–10%, respectively; the differences were all at a significant level with p < 0.01. Mean arterial pressures for all months evaluated ranged from −218.6 to −238.1, and venous pressures averaged between 179.8 to 213.7. Only three patients experienced late complications (all of which were infections) and no patients required hospitalization post complication. Two were bacteremic; the other had tunnel infection without positive blood cultures. This is the first retrospective study to evaluate the adequacy of hemodialysis with the Cannon catheter. Our study showed that flow rates and adequacy of hemodialysis can be reached using the Cannon catheter, with minimal complications.
A case of plasma component exchange using membrane plasma separator EVACURE™
Authors: Sakaji I. , Kasahara M. , Ishida Y. , Yoshikawa M. , Nitta T. , Matsushima Y. , Iwatani Y. , Yoshimoto A. , Suzuki T.
Published: January 2005

Objective: 
We report a patient with urosepsis, Lleptospira syndrome, TTP‐HUS syndrome, fulminant hepatic failure, vasculitis syndrome and TSS treated with plasma component exchange. Methods: Conditions for plasma component exchange were membrane plasma separator (Evacure EC‐3A), substitute fluid (3 % albumin solution), blood flow rate (150 mL/min), filtration rate (30 mL/min), quantity of substitute fluid (4,600 mL) and anticoagulant (nafamostat mesilate 30 mg/hr). Result: Plasma component exchange in combination with hemodiafiltration induced a rapid remission of both hepatic toxicity and renal failure caused by streptococcal sepsis. Membrane plasma separator evacure EC‐3A allowed the use of 3% albumin solution as substitute fluid. Colloid osmotic pressure temporarily increased after the treatment, but within 24 hours, returned to the same level as before the treatment. Conclusion: Plasma component exchange using a membrane plasma separator may allow the use of albumin instead of fresh frozen plasma (FFP) as substitute fluid, which results in a lower risk of infection.
Factors affecting concentration of citrate in dialyzers when using citrate hemodialysate in vitro
Authors: Baosong G. , Ning N. , Ganglian Y. , Lin G. , Liangqi W. , Ruijun G.
Published: January 2005

Objective: 
To observe the factors that affect the citrate concentration in hollow fiber when using citrate hemodialysate. Methods: By modeling hemodialysis in vitro, we studied 6 types of hemodialyzers at different blood flow rates, different dialysate flow‐rate, and different fluids in vitro to detect the citrate concentration in hollow fiber. Results: The citrate concentrations in different hemodialyzers were F60 > FB‐130UGA > GA‐HP130 > F6 > FB‐130AGA > WS‐70 in turn. The concentrations at different blood flow‐rates were different 100 mL/min > 200 mL/min. Conclusions: The concentration of citrate in hollow fiber is affected by different types of hemodialyzers and different blood as well as dialysate flow‐rates. To achieve anticoagulation when using citrate hemodialysate, we must select suitable hemodialyzer such as FB‐130UGA.
Effect of dialyzer reprocessing on glucose homeostasis
Authors: Ibrahim M.A. , Labib B. , Sallam T. , Sarhan I. , El‐Damasy H.
Published: January 2005

This study was designed to investigate the possible effect of dialyzer re‐use on glucose hemostasis. Twenty patients with end stage renal failure (including ten non insulin dependent diabetes mellitus [NIDDM]) on thrice weekly hemodialysis (using glucose free dialysate), were studied by serial assessment of blood glucose, C‐peptide, interleukin 1‐B (IL‐IB), Ca, Na and K at zero, 1 and 4 hours (end of dialysis) during hemodialysis on new, and then on re‐used (first) cuprophane dialyzers. Our results showed significant rise of C‐peptide, IL‐1B with drop of blood glucose in first hour sample (and was symptomatic in some diabetics) in both groups when using new dialyzers but these changes were less marked and totally asymptomatic when using reprocessed dialyzers. In addition there was a significant positive correlation between IL‐1B level and C‐peptide at 1 and 4 hour samples and negative correlation between IL‐1B and blood glucose at 1 and 4 hour samples.

Conclusion:
Through the effect of IL‐1B on insulin release curophane dialyzers can affect glucose homeostasis especially in diabetics and hypoglycemia might be part of the first use syndrome. It may be recommended that measurement of glucose effect of dialysis membrane on glucose homeostasis might be an important parameter of membrane bioincompatibility.
High resolution magic angle spinning NMR spectroscopy used to investigate the ability of drugs to bind to synthetic melanin
Authors: Borel Michèle , Lafarge David , Moreau Marie France , Bayle Martine , Audin Laurent , Moins Nicole , Madelmont Jean‐Claude
Published: January 2005

Iodobenzamides are known to possess an affinity for melanoma tissue dependent on tumor pigmentation. In order to investigate the molecular interactions of drugs with melanin in vitro, a synthetic pigment swelled in deuterium buffer at physiological pH was used. The spectra of various mixtures of each Iodobenzamide (BZ) with melanin were studied at 25°C by NMR under MAS conditions. The drug which interacts with the pigment exhibits linewidths greater than those observed for the free drug in solution. Line‐broadening of the resonance occurred for the N‐methyl group of acetylcholine or N‐ethyl and aromatic groups of BZ. However, linewidths associated with methanol or hippuric acid were less altered by the presence of melanin. These observations indicate the specificity of the interaction between some drug moieties and the sites of melanin. From the concentration dependence of line‐broadening, the apparent equilibrium dissociation constant (Kd) of drug interaction with melanin was approached. It seems that the residual concentration‐dependent line‐broadening is caused by perturbations of ligand exchange between free and bound states and by differences in magnetic susceptibility present in the sample at the pigment‐interacting drug moiety interface. Taken together, these results demonstrate the utility of this technique for investigating binding drugs.
INJURY OF THE COLLATERAL LIGAMENTS OF THE DISTAL INTERPHALANGEAL JOINT DIAGNOSED BY MAGNETIC RESONANCE
Authors: Zubrod Chad J. , Farnsworth Kelly D. , Tucker Russell L. , Ragle Claude A.
Published: January 2005

We describe the clinical, imaging, and necropsy findings of two horses with severe injury of the collateral ligaments of the distal interphalangeal (DIP) joint diagnosed using magnetic resonance (MR) imaging. In MR images it was possible to examine the collateral ligaments of the DIP joint from the origin at the middle phalanx to the insertion on the distal phalanx. Both horses in this report had abnormal high signal intensity within the collateral ligaments of the DIP joint, and one horse had abnormal high signal intensity within the bone of the distal phalanx on short tau inversion recovery (STIR) and T2‐weighted imaging sequences. High signal intensity on STIR and T2‐weighted images represents abnormal fluid accumulation indicative of inflammation, within ligament, tendon, or bone on these imaging sequences. Abnormalities were confirmed on necropsy in both horses. Injury of the collateral ligaments of the DIP joint should be considered as a source of pain in horses with lameness localized to the foot.
RADIOGRAPHIC DIAGNOSIS–PARASPINAL ABSCESS IN A DOG
Authors: Naughton James F. , Tucker Russell L. , Bagley Rodney S.
Published: January 2005

A two‐year‐old intact male Brittany Spaniel was admitted for evaluation of progressive spinal pain. Previous treatment had been initiated for suspected lumbosacral intervertebral disk disease, however there was poor response to therapy. On presentation the dog was laterally recumbent and neurological examination revealed hyperesthesia over the lumbar vertebral segments.

On survey radiography there was loss of detail in the sublumbar fascial planes and inconclusive lumbar vertebra proliferation. Magnetic resonance (MR) imaging was performed to better evaluate the lumbar spine and surrounding tissues, which revealed extensive paralumbar cellulitis, abscessation and osteomyelitis with extradural compression of the spinal cord. MR imaging allowed delineation of the abscessed area, and distinct visualization of its extension into and involvement of the surrounding tissues including muscle, fat, and retroperitoneal structures.

In this case, MR imaging was instrumental in defining the extent of the infection and determining whether medical or surgical management of the diseased tissue was necessary. If available, MR may be the imaging method of choice for evaluation of paraspinal abscesses yielding a better insight to the spinal structures involved and facilitating medical or surgical intervention.
DYNAMIC COMPUTED TOMOGRAPHY OF THE NORMAL FELINE HYPOPHYSIS CEREBRI (GLANDULA PITUITARIA)
Authors: Tyson Reid , Graham John P. , Bermingham Eden , Randall Stacy , Berry Clifford R.
Published: January 2005

The purpose of this study was to describe normal feline hypophyseal mensuration and contrast enhancement characteristics using dynamic computed tomography (CT) imaging. An intravenous bolus of an ionic iodinated contrast medium was administered to eight cats using a pressure injector while dynamic CT images were obtained every 5 s for five cats and every 7 s for three cats for a total imaging time of 5 min. Each pituitary was measured at its maximum height and width on the peak contrast medium enhancement image. A hand‐drawn region of interest was placed around each hypophysis cerebri and time attenuation curves were generated. The specific enhancement pattern of the hypophysis cerebri for each cat was recorded. The mean width and height of the hypophysis cerebri was 5.2±0.4 (average±SD) mm and 3.1±0.3 mm, respectively. The mean time to maximum contrast enhancement was 28.6±14.8 s (range 14–50 s) from the onset of contrast medium injection. Four cats had initial dorsal and peripheral contrast enhancement patterns of the hypophysis cerebri, while four cats had an initial central contrast medium enhancement pattern. The hypophysis cerebri had a homogenous appearance in all cats, 28–50 s after contrast medium injection. The average (±SD) clearance half‐time was 292 (±87) s. Normal hypophysis cerebri mensuration and contrast medium enhancement characteristics will help in clinical evaluation of the feline hypophysis cerebri.
CONGENITAL ELBOW SUBLUXATION IN A CAT
Authors: Valastro Carmela , Di Bello Antonio , Crovace Antonio
Published: January 2005

Congenital elbow luxations are responsible for 17–20% of nontraumatic lameness of the elbow joint. They are not associated with a growth disorder or trauma. Congenital elbow luxation has been observed in dogs, but no data were found about this condition in cats. In this report, we describe congenital bilateral elbow subluxation in a cat.
ACANTHOMATOUS AMELOBLASTOMA OF THE MAXILLA OF AN ADULT ALPACA
Authors: Britt Lisa G. , Middleton John R. , Warhover Terri Tucker , Kreeger John M. , Branson Keith R.
Published: January 2005

An adult alpaca presented with a large maxillary swelling. Facial trauma or a tooth root abscess was suspected. Radiographically there was a large expansile lesion displacing the right maxillary teeth. An ameloblastoma was diagnosed histologically and palliative radiation therapy was attempted. Because of poor response to therapy and anorexia the animal was euthanized. Necropsy findings confirmed an ameloblastoma of acanthomatous type.
ULTRASONOGRAPHIC EVALUATION OF PRE‐ AND POSTNATAL DEVELOPMENT OF THE EYES IN BEAGLES
Authors: Boroffka Susanne A. E. B.
Published: January 2005

Transabdominal ultrasonography was performed to visualize the development of intraocular structures of both eyes of four different fetuses in each of two pregnant beagles. Postnatally the development of both eyes of 11 pups was visualized with ultrasonography. Furthermore, biometric measurements of the length of the eye, the depth of cornea, the anterior chamber, the lens (anteroposterior depth and equatorial diameter), and the vitreous body of the fetuses and pups were obtained when these structures could be identified with ultrasonography. In all fetuses the eyes with lens, vitreous body, hyaloid artery, and scleroretinal rim could be clearly identified from day 37 of pregnancy. Postnatally also the cornea, anterior chamber, iris, ciliary body, and optic disc were visible. Biometric measurements revealed, both pre‐ and postnatally, a continuous growth of the depth of the eye, anterior chamber, lens (anteroposterior depth and equatorial diameter), and vitreous body.
ULTRASONOGRAPHIC EVALUATION OF CRANIAL CRUCIATE LIGAMENT RUPTURE VIA DYNAMIC INTRA‐ARTICULAR SALINE INJECTION
Authors: Seong Yunsang , Eom Kidong , Lee Haeoon , Lee Jeongmin , Park Jinhee , Lee Keunwoo , Jang Kwangho , Oh Taeho , Yoon Junghee
Published: January 2005

Ultrasonographic examination of both stifle joints of five clinically and radiographically normal adult dogs was performed before and after surgical transection of the cranial cruciate ligament (CrCL). At pre‐ and postsurgery, the hyperechoic patellar ligament and the infrapatellar fat interfered with sonographic visualization of the CrCL. When the stifle joint, however, was imaged via dynamic intra‐articular saline injection, the hyperechoic ligament was visualized because of the separation of the infrapatellar fat and the CrCL and the contrasting effect of anechoic saline. When the stifle joint was imaged by real‐time scanning after the transection of the CrCL, flutter of the ligament and an anechoic area between the bone and the CrCL were identified. The increased diameter of the ligament and the increased thickness of the joint space were identified as well. Ultrasonographic examination via dynamic saline injection into the joint space has potential as a diagnostic tool for assessing CrCL rupture.
TOTAL ANOMALOUS PULMONARY VENOUS CONNECTION IN A FOAL
Authors: Diaz Olga Seco , Desrochers Anne , Hoffmann Vickie , Reef Virginia B.
Published: January 2005

An 8‐day‐old Arabian–Morgan cross colt underwent cardiac evaluation. The foal was tachycardic, tachypneic, exercise intolerant and had a loud right‐sided heart murmur and cyanotic mucous membranes. Total anomalous pulmonary venous connection was diagnosed with echocardiography and confirmed at postmortem examination. Total anomalous pulmonary venous connection is a very rare congenital cardiac abnormality that has not been reported before in the horse.
Data‐driven docking for the study of biomolecular complexes
Authors: van Dijk Aalt D. J. , Boelens Rolf , Bonvin Alexandre M. J. J.
Published: January 2005

With the amount of genetic information available, a lot of attention has focused on systems biology, in particular biomolecular interactions. Considering the huge number of such interactions, and their often weak and transient nature, conventional experimental methods such as X‐ray crystallography and NMR spectroscopy are not sufficient to gain structural insight into these. A wealth of biochemical and/or biophysical data can, however, readily be obtained for biomolecular complexes. Combining these data with docking (the process of modeling the 3D structure of a complex from its known constituents) should provide valuable structural information and complement the classical structural methods. In this review we discuss and illustrate the various sources of data that can be used to map interactions and their combination with docking methods to generate structural models of the complexes. Finally a perspective on the future of this kind of approach is given.
Probing the access of protons to the K pathway in the Paracoccus denitrificans cytochrome c oxidase
Authors: Richter Oliver‐M. H. , Dürr Katharina L. , Kannt Aimo , Ludwig Bernd , Scandurra Francesca M. , Giuffrè Alessandro , Sarti Paolo , Hellwig Petra
Published: January 2005

In recent studies on heme‐copper oxidases a particular glutamate residue in subunit II has been suggested to constitute the entry point of the so‐called K pathway. In contrast, mutations of this residue (E78II) in the Paracoccus denitrificans cytochrome c oxidase do not affect its catalytic activity at all (E78IIQ) or reduce it to about 50% (E78IIA); in the latter case, the mutation causes no drastic decrease in heme a3 reduction kinetics under anaerobic conditions, when compared to typical K pathway mutants. Moreover, both mutant enzymes retain full proton‐pumping competence. While oxidized‐minus‐reduced Fourier‐transform infrared difference spectroscopy demonstrates that E78II is indeed addressed by the redox state of the enzyme, absence of variations in the spectral range characteristic for protonated aspartic and glutamic acids at ≈ 1760 to 1710 cm−1 excludes the protonation of E78II in the course of the redox reaction in the studied pH range, although shifts of vibrational modes at 1570 and 1400 cm−1 reflect the reorganization of its deprotonated side chain at pH values greater than 4.8. We therefore conclude that protons do not enter the K channel via E78II in the Paracoccus enzyme.
An immunomodulator used to protect young in the pouch of the Tammar wallaby, Macropus eugenii
Authors: Baudinette Russell V. , Boontheung Pinmanee , Musgrave Ian F. , Wabnitz Paul A. , Maselli Vita M. , Skinner Jayne , Alewood Paul F. , Brinkworth Craig S. , Bowie John H.
Published: January 2005

Eugenin [pGluGlnAspTyr(SO3)ValPheMetHisProPhe‐NH2] has been isolated from the pouches of female Tammar wallabies (Macropus eugenii) carrying young in the early lactation period. The sequence of eugenin has been determined using a combination of positive and negative ion electrospray mass spectrometry. This compound bears some structural resemblance to the mammalian neuropeptide cholecystokinin 8 [AspTyr(SO3)MetGlyTrpMetAspPhe‐NH2] and to the amphibian caerulein peptides [caerulein: pGluGlnAspTyr(SO3)ThrGlyTrpMetAspPhe‐NH2]. Eugenin has been synthesized by a route which causes only minor hydrolysis of the sulfate group when the peptide is removed from the resin support. Biological activity tests with eugenin indicate that it contracts smooth muscle at a concentration of 10−9 m, and enhances the proliferation of splenocytes at 10−7 m, probably via activation of CCK2 receptors. The activity of eugenin on splenocytes suggests that it is an immunomodulator peptide which plays a role in the protection of pouch young.
Expression of an α‐1,3‐glucanase during mycoparasitic interaction of Trichoderma asperellum
Authors: Sanz Luis , Montero Manuel , Redondo José , Llobell Antonio , Monte Enrique
Published: January 2005

Trichoderma species have been investigated as biological control agents for over 70 years owing to their ability to antagonize plant pathogenic fungi. Mycoparasitism, one of the main mechanisms involved in the antagonistic activity of Trichoderma strains, depends on the secretion of complex mixtures of hydrolytic enzymes able to degrade the host cell wall. The antifungal activity of an α‐1,3‐glucanase (EC 3.2.1.59, enzymes able to degrade α‐1,3‐glucans and also named mutanases) has been described in T. harzianum and its role in mycoparasitic processes has been suggested. In this study, we report on the purification, characterization and cloning of an exo‐α‐1,3‐glucanase, namely AGN13.2, from the antagonistic fungus T. asperellum T32. Expression at the transcription level in confrontation assays against the strawberry pathogen Botrytis cinerea strongly supports the role of AGN13.2 during the antagonistic action of T. asperellum.
Functional expression of olfactory receptors in yeast and development of a bioassay for odorant screening
Authors: Minic Jasmina , Persuy Marie‐Annick , Godel Elodie , Aioun Josiane , Connerton Ian , Salesse Roland , Pajot‐Augy Edith
Published: January 2005

The functional expression of olfactory receptors (ORs) is a primary requirement to examine the molecular mechanisms of odorant perception and coding. Functional expression of the rat I7 OR and its trafficking to the plasma membrane was achieved under optimized experimental conditions in the budding yeast Saccharomyces cerevisiae. The membrane expression of the receptor was shown by Western blotting and immunolocalization methods. Moreover, we took advantage of the functional similarities between signal transduction cascades of G protein‐coupled receptor in mammalian cells and the pheromone response pathway in yeast to develop a novel biosensor for odorant screening using luciferase as a functional reporter. Yeasts were engineered to coexpress I7 OR and mammalian Gα subunit, to compensate for the lack of endogenous Gpa1 subunit, so that stimulation of the receptor by its ligands activates a MAP kinase signaling pathway and induces luciferase synthesis. The sensitivity of the bioassay was significantly enhanced using mammalian Golf compared to the Gα15 subunit, resulting in dose‐dependent responses of the system. The biosensor was probed with an array of odorants to demonstrate that the yeast‐borne I7 OR retains its specificity and selectivity towards ligands. The results are confirmed by functional expression and bioluminescence response of human OR17‐40 to its specific ligand, helional. Based on these findings, the bioassay using the luciferase reporter should be amenable to simple, rapid and inexpensive odorant screening of hundreds of ORs to provide insight into olfactory coding mechanisms.
Response to abscisic acid application and hormone profiles in spring Brassica napus seed in relation to secondary dormancy
Authors: Gulden Robert H , Chiwocha Sheila , Abrams Suzanne , McGregor Ian , Kermode Allison , Shirtliffe Steven
Published: January 2005

The plant hormone abscisic acid (ABA) has been implicated in the inception and maintenance of seed dormancy, while gibberellins promote dormancy breakage and germination in some species. We investigated whether osmotic stress induced secondary dormancy in Brassica napus L. is associated with changes in ABA sensitivity and metabolism, as well as changes in gibberellin levels. Seeds of two genotypes, one with low dormancy potential (LDP) and one with high dormancy potential (HDP) for secondary dormancy, were exposed to a dormancy-inducing osmotic treatment for up to 4 weeks and then germinated in the presence of increasing ABA concentrations. Even at relatively high concentrations of supplied ABA, germination of LDP seed was not inhibited, while relatively low ABA concentrations inhibited the germination of HDP seed after osmotic treatment. Fluridone was highly effective in suppressing secondary dormancy development in HDP seed, but had no effect on germinability in LDP seed. Despite the lack of differences in nonosmotically treated seed, ABA and ABA-glucose ester accumulated to higher levels, and gibberellin A1 accumulated to lower levels, in HDP relative to LDP seed by the end of the osmotic treatment. Our findings indicate an association among ABA sensitivity, biosynthesis and accumulation, and secondary dormancy potential in B. napus seed.Key words: abscisic acid (ABA), Brassica napus, fluridone, induced dormancy, osmotic stress, sensitivity.
Development of the unfertilized embryo sac and pollen tubes in the dwarf mistletoe Arceuthobium americanum (Viscaceae)
Authors: Ross Cynthia M , Sumner Michael J
Published: January 2005

Megasporogenesis, embryo sac development, and pollen tubes in Arceuthobium americanum Nutt. ex Engelm. were investigated with light, fluorescence, and electron microscopy. The orthotropous ovular structure of A. americanum lacked integuments and possessed a nucellus that was largely continuous with and indistinguishable from the placenta; we coined this structure the placental–nucellar complex (PNC). Two megasporocytes became evident in the tenuinucellate PNC by mid-April, and had undergone bisporic megasporogenesis by mid-May. The upper cell from each dyad (distal to the base of the PNC) became a functional megaspore, although only one would develop into a seven-celled embryo sac. Like typical angiosperm embryo sacs, that of A. americanum possessed an egg cell having the ultrastructure reflective of a quiescent cell, and lacked cellulosic and (or) hemicellulosic wall material between the egg apparatus and central cell. However, the egg apparatus arose at the lower embryo sac pole, not at the upper as expected for an orthotropous ovule. A hypothetical model for the development of Arceuthobium ovules is the ancestral fusion and subsequent reduction of two anatropous ovules to form two embryo sacs within the PNC, of which only one completes development. The synergids have no role in pollen tube guidance, as tubes could be seen below each functional megaspore prior to megagametogenesis.Key words: Arceuthobium, embryo sac, megasporogenesis, mistletoe, pollen tubes, ultrastructure.
Effect of seed mass on early seedling growth of five eastern white pine (Pinus strobusL.) families under contrasting light environments
Authors: Parker William C , Noland Thomas L , Morneault Andrée E
Published: January 2005

The strong influence of seed mass on early seedling growth of forest tree species is well established, but the ecological role of intraspecific variation in seed mass on natural regeneration is poorly understood. Wide variation in initial spatial patterns of natural regeneration of eastern white pine (Pinus strobus L.) between managed and undisturbed white pine forests of the Great Lakes region of North America has been attributed to differences in understory light levels and the frequency of substrates suitable for germination and seedling establishment. To explore the potential influence of seed mass on these observed patterns, the interaction of seed mass and light on early growth of white pine was investigated in a greenhouse study. Seedlings of five half-sib families differing in mean seed mass were grown for 8 and 14 weeks under moderate and low light conditions representing managed and undisturbed pine stands, respectively. Family differences in seedling biomass and root system development under each light environment were associated with positive, linear relationships with mean seed mass. Family and seed mass had a comparatively weak influence on biomass partitioning and relative growth rate. Moderate light improved seedling growth regardless of seed mass, but relative expression of seed mass effects on seedling traits was unaffected by light environment. These results suggest differential recruitment of white pine in managed and undisturbed stands is unrelated to variation in seed mass.Key words: biomass allocation, eastern white pine, greenhouse experiment, natural regeneration, relative growth rate, seed mass.
Leaf thickness ofSalixspp. (Salicaceae) from the Athabasca sand dunes of northern Saskatchewan, Canada
Authors: Cooper R L , Ware J V , Cass D D
Published: January 2005

Leaf thicknesses of Salix taxa (Salix brachycarpa Nutt. var. psammophila Raup, Salix planifolia Pursh subsp. tyrrellii (Raup) Argus, Salix silicicola Raup, and Salix turnorii Raup) from the Athabasca sand dunes in northern Saskatchewan, Canada, were evaluated and compared with those of their respective widespread progenitors (S. brachycarpa Nutt. var. brachycarpa, S. planifolia Pursh subsp. planifolia, Salix alaxensis (Anders.), and Salix eriocephala Michx. var. famelica (C. R. Ball) Dorn). Leaf thickness was measured using standard light microscopy, and results were compared with the occurrence of amphistomaty in these Salix species. Leaf thickness values varied among the species and differed significantly within each derivativeprogenitor Salix pair. The two amphistomatic taxa from Yakow Lake dunes, S. turnorii and S. planifolia subsp. tyrrellii, had significantly thicker leaves (337.65 ± 5.99 µm and 226.00 ± 5.22 µm, respectively) than their widespread progenitors, as well as the thickest leaves overall. The data comparison indicates a relationship between amphistomaty and leaf thickness among the Salix taxa, as thicker leaves tend to be amphistomatic.Key words: amphistomaty, Athabasca sand dunes, leaf thickness, Salix, willow.
Distance between pollen donor and recipient influences fruiting success in slickspot peppergrass, Lepidium papilliferum
Authors: Robertson Ian C , Ulappa Amy Colleen
Published: January 2005

Plant populations are often spatially structured owing to limited dispersal of pollen and seed. Mating between neighboring individuals in such populations often leads to reduced reproductive performance relative to matings between distant individuals. This response, which may be a result of inbreeding depression or prezygotic mating barriers, was investigated for slickspot peppergrass, Lepidium papilliferum L. (Brassicaceae), a rare insect-pollinated mustard endemic to sagebrushsteppe habitat in southwestern Idaho. Through hand pollination experiments we found that individual plants receiving pollen from distant sources (75100 m and 6.520 km away) had significantly higher percent fruit sets than those relying on pollen from neighboring plants (<1 m away). Self pollinated plants produced little or no fruit. These results suggest that L. papilliferum relies primarily, if not exclusively, on outcrossed pollination, and that its populations are spatially structured. Conservation efforts should therefore strive to protect sufficiently large areas of suitable habitat to ensure maintenance of genetic diversity and preserve or enhance connectivity between populations.Key words: Brassicaceae, inbreeding, outbreeding, population spatial structure, rare species.
Soil seed bank composition over desert microhabitats: patterns and plausible mechanisms
Authors: Marone Luis , Cueto Víctor R , Milesi Fernando A , Casenave Javier Lopez de
Published: January 2005

We assessed soil seed bank composition and size over several microhabitats of two habitats of the central Monte Desert of Argentina (open Prosopis woodland and Larrea shrubland) to analyse differences among them. Seed densities were similar to those already reported for other deserts, but we found consistent differences in seed composition among microhabitats. Whereas grass seeds (e.g., Aristida, Pappophorum, Neobouteloua, Trichloris, Digitaria) prevailed in natural depressions of open areas, forb seeds (e.g., Phacelia, Lappula, Descurainia, Plantago, Chenopodium) were more abundant under trees. The comparison of seed production during primary dispersal (i.e., seed rain) with seed density on the ground at the end of dispersal indicated that most forb seeds entered the habitat through the micro habitats located beneath the canopy of trees and tall shrubs, and remained there after redistribution. Most grass seeds, by contrast, entered it through bare-soil and under-grass microhabitats, and reached more even distributions after secondary dispersal, especially because of dramatic losses in bare soil. Patterns of plant recruitment and seed dynamics in specific microhabitats were better understood when differences of soil seed bank composition, but not of total seed density, were taken into account.Key words: Monte Desert, seed dispersal, seed predation, seed production, seeds.
Calcium oxalate crystal macropattern development during Prunus virginiana (Rosaceae) leaf growth
Authors: Lersten Nels R , Horner Harry T
Published: January 2005

In this first study of foliar crystal macropattern initiation and development, primordia to just-shed bud scales, stipules, and leaves were bleached, cleared, and viewed microscopically. Apical clusters of prismatics appear first in the 0.1-mm stipule; crystals proliferate basipetally as stipules elongate. Apical prismatics appear next in a 0.5-mm leaf; they remain isolated until tiny prismatics appear in scattered palisade cells throughout the lamina of a 1.0- to 1.5-cm leaf. Meanwhile, druses proliferate from stem through elongating petioles, reaching the base of 2- to 4-cm leaves. Lamina prismatics enlarge, and new ones appear. In the midvein, short files of tiny druses reach the apex of the 4- to 5-cm leaf, and files of druses extend into lower main lateral veins. In 9- to 11-cm (full-grown) mid-May leaves, lamina prismatics are numerous and conspicuous, but small druses have extended into smaller veins. Until leaf shedding, some lamina prismatics continue to enlarge, new ones form, and others become surrounded by tiny pris matics. Druses gradually occupy all vein orders, and many in the smallest veins become quite large with conspicuous cores. The mature crystal macropattern shows druses confined to stem, petiole, and leaf veins, whereas prismatics are localized in stipules, bud scales, and leaf lamina.Key words: calcium oxalate, crystal macropattern, druse, leaves, prismatics, Prunus, Rosaceae.
Late-glacial lakes in the Thompson Basin, British Columbia: paleogeography and evolution
Authors: Johnsen Timothy F , Brennand Tracy A
Published: January 2005

During the decay of the Cordilleran Ice Sheet 10 000  13 000 BP, glacial lakes developed within valleys that dissect the Interior Plateau of British Columbia. In this paper, we (1) illustrate a procedure for assessing paleo water planes that has general application, (2) document lake paleogeography and evolution in the Thompson Valley, (3) provide new data on the glacio-isostatic response of the central Cordillera, and (4) present new evidence of its late-glacial environment. We employ geomorphology and sedimentology, digital elevation models, and new technologies (differential global positioning systems, ground penetrating radar, and geographic information systems) to refine paleogeographic reconstructions of glacial lakes. Glacial Lake Thompson and Glacial Lake Deadman were ribbon-shaped (width to length ratio ≈ 3:100), deep (>>140 to ~50 m) lakes that contained significant water volumes (8424 km3). They lengthened to the west and their water level lowered as ice decayed. Final ice dam failure resulted in an ~20 km3jökulhlaup that eroded bedforms and deposited flood eddy bars within the lake basin, travelled ~250 km along the Fraser River system, and may have deposited exotic mud offshore between 10 190 and 11 940 BP. Glacio-isostatic tilts of water planes are among the highest in the world (1.71.8 m km1). Their orientations suggest that ice sheet loads were greater or longer- lived to the north-northwest of the study area, lending support to the notion of an ice divide centred on the Fraser Plateau.
Depositional and tectonic setting of the Miocene Wood Mountain Formation, southern Saskatchewan
Authors: Leckie Dale A , Bednarski Jan M , Young Harvey R
Published: January 2005

Coarse gravels of the Miocene Wood Mountain Formation that cap the Wood Mountain upland in southern Saskatchewan are an erosional remant of a much more expansive sheet of gravel and sand. The formation consists of gravel and sand deposited as a thin sheet on a regional planation surface that extends approximately along strike for at least 160 km. This sheet, with a maximum thickness of 31 m, is the deposit of low-sinuosity, braided-river channels that flowed to the north-northeast. The Wood Mountain Formation represents an initial episode of erosion followed by low-accommodation deposition, where the net aggradation rate was likely low. The sediments of the Wood Mountain Formation are associated with change in tectonic style in western North America from one of compression to one of extension. The gravels were deposited above a regional erosion surface associated with isostatic uplift of the central Montana Uplift.
Geochemistry and geodynamic implications of the Mesoproterozoic English Bay granite–rhyolite complex, northwestern Ontario
Authors: Hollings Pete , Fralick Philip , Kissin Stephen
Published: January 2005

The Mesoproterozoic English Bay Complex consists of a granite-rhyolite assemblage outcropping on the shores of Lake Nipigon in western Superior Province, Canada. It intrudes Neoarchean rocks and is disconformably overlain by a rift–infracratonic basin sedimentary succession recording subsidence following a heating event. The granites and rhyolites are characterized by light rare-earth element (LREE) enrichment (La/Smn = 2.8–5.1) and only weakly fractionated heavy REE (HREE; Gd/Ybn = 1.1–1.6). The felsic igneous rocks are high-K, enriched in Zr, Nb, Y, and REE satisfying all the criteria for an A-type suite. Trace element geochemistry, particularly the absence of any negative Nb anomalies, indicates this melt did not originate in a suprasubduction zone setting, unlike the St. Francois Mountain Complex to the south. The English Bay Complex may record the northern portion of a Mesoproterozoic plume track— a plume that possibly led to earlier igneous activity and infracratonic basin formation to the north and would later interact with a suprasubduction zone margin to the south.
Seasonal isotopic imprint in moonmilk from Caverne de l'Ours (Quebec, Canada): implications for climatic reconstruction
Authors: Lacelle Denis , Lauriol Bernard , Clark Ian D
Published: January 2005

Moonmilk, which is often seen coating walls in temperate caves, is a porous secondary calcite deposit composed of an aggregate of microcrystalline calcite and water. This study, based on moonmilk deposits found in Caverne de l'Ours, Ottawa Valley region, proposes a model for its formation based on the calcite and water isotope chemistry and evaluates its use as a climatic proxy. In Caverne de l'Ours, non-calcitic mineral inclusions protrude from the bedrock (Grenville marble) into the moonmilk, while others are entirely enclosed within the moonmilk. This observation suggests a mechanism of bedrock dissolution and reprecipitation for the formation of moonmilk, which is controlled by the changing seasonal climate in the cave. The δ18O of the moonmilk interstial water indicates that the condensation of water vapour occurs mostly in winter and spring. The condensation of water vapour on the surface of the walls allows for the dissolution of the Grenville marble and releases ions necessary for the precipitation of moonmilk. The δ18O and δ13C of calcite and δ18O of the moonmilk interstitial water indicate that precipitation of moonmilk occurs during summer and fall. During these seasons, the relative humidity in the cave decreases resulting in moonmilk growth through the slow evaporation of calcite-saturated water. A comparison of the δ18O record of moonmilk from caves in Gaspésie (Canada) and from Aven d'Orgnac (France) shows that this material retains temperature information valuable for paleoclimatic reconstructions.
Multinuclear magnetic resonance studies of the aqueous products of the complexes cis- and trans-Pt(amine)2(NO3)2
Authors: Rochon Fernande D , Buculei Viorel
Published: January 2005

The hydrolyis or the aquation reactions of the compounds cis- and trans-Pt(amine)2(NO3)2 were studied in D2O in different conditions of pH. The products were characterized by multinuclear (195Pt, 13C, and 1H) magnetic resonance spectroscopy. In acidic medium, the product was [Pt(amine)2(D2O2)]2+ and for a few amines, trans- [Pt(amine)2(D2O)(NO3)]+ was detected. The 195Pt NMR resonances of the diaqua complexes were observed at higher fields for the cis compounds (avg. 1727 ppm) than for the trans isomers (avg. 1560 ppm). At basic pH, Pt(amine)2(OD)2 was formed and for ethylamine, trans-Pt(EtNH2)2(OD)(NO3) was detected. The cis compounds were also observed at higher fields than the trans isomers (1706 ppm vs. 1574 ppm). The coupling constants with 195Pt were geometry dependent. The avg. 2J(195Pt-1H) values for the diaqua species were 66 (cis) and 57 (trans) Hz, while the avg. 3J(195Pt-1H) were 43 (cis) and 34 (trans) Hz for the diaqua compounds, and 43 and 37 Hz, respectively, for the dihydroxo species. The 2J(195Pt-13C) avg. values were 18 (cis) and 12 (trans) Hz and the avg. 3J(195Pt-13C) were 31 (cis) and 23 (trans) Hz for both the diaqua and dihydroxo compounds. For the cis isomers, at neutral pH, the monoaquamonohydroxo species (avg. 1721 ppm) and the dihydroxo-bridged dimer (avg. 1353 ppm) were observed. For a few amines, the monohydroxo-bridged dimer was observed (avg. 1684 ppm) and its concentration increased with time. For the trans compounds, the monoaquamonohydroxo species was observed at 1563 ppm (avg.). For a few amines, the hydroxo-bridged dimer was present. For methylamine, a third species assigned to a higher oligomer was observed after 6 months.Key words: platinum, amine, nitrato, hydrolysis, NMR, aquation.