bluuebunny/crossref_metadata_2025 huggingface dataset:
Cellular Adenosine Triphosphate Production and Consumption in the Descending Thin Limb of Henle’s Loop in the Rat
Authors: Jung Kyu Yong , Endou Hitoshi
Published: November 2008

To characterize the properties of cellular adenosine triphosphate (ATP) production and consumption in the descending thin limb of Henle’s loop (DTL) in rats, we measured the cellular ATP content by applying the microchemiluminescence method. For ATP production, isolated DTL from the short- and long-loop nephron (SDL and LDL, respectively) was incubated with several substrates such as alanine, glucose, glutamine, β-hydroxybutyrate (β-HBA), lactate, and pyruvate; for ATP consumption, DTL was incubated in the presence or absence of either ouabain or monensin. ATP production from each substrate indicated that glucose and pyruvate were the preferred substrates to maintain cellular ATP in both SDL and LDL. ATP production from glutamine, β-HBA, and lactate was substantial in LDL. In SDL, glutamine was the preferred substrate, and β-HBA and lactate were minimal. The utilization of alanine was minimal in both LDL and SDL. The cellular ATP was significantly restored by ouabain at concentrations of 1.5 ×ICl-5 and 1.5×10–3M in LDL, but in SDL only at 1.5×10–3M. In both segments, the cellular ATP level was significantly decreased by monensin above the concentrations of 1 µg/ml in LDL and 5 µg/ml in SDL. From these observations, we conclude that there exist clear differences between LDL and SDL in ATP-supplying substrate specificities and ATP-consuming properties.
Renal Norepinephrine Content Decreases after Chronic Flow Probe Implantation
Authors: Kaczmarczyk Gabriele , Langer M. , Schulze G.
Published: November 2008

Electromagnetic flow probes were chronically implanted around the left renal artery in 6 female beagle dogs. 3–10 months after implantation, renal cortex norepinephrine contents of right and left kidneys were compared (liquid chromatography). In 4 out of the 6 dogs investigated 3–6 months after implantation, the norepinephrine content of the left kidney was reduced by 27–72%. In 2 dogs investigated 7 and 10 months after implantation, the difference between left and right kidney was not significant. These findings should be taken into consideration when interpreting results from chronically instrumented kidneys.
Metabolism of Lactate by a Suspension of Dog Thick Ascending Limbs: Relations with Transport
Authors: Tejedor A. , Noël J. , Sénécal J. , Vinay P. , Berteloot A. , Boulanger Y. , Gougoux A.
Published: November 2008

The addition of substrate in the form of lactate (L), but not glucose (G), increases the respiration of canine thick ascending limb (TAL) segments in a saturable (above 2 mM) fashion. More than 60% of this stimulation is ouabain-sensitive (1 mM ouabain) even if L and G transport are both sodium-insensitive processes in TAL. Thus L, but not G, specifically stimulates Na+ entry in TAL cells and its subsequent transport by the Na+, K+-ATPase. If chloride is substituted for by gluconate, no significant substrate-induced stimulation of ouabain-sensitive respiration is observed. SITS (4-acetamino-4’-isothiocyanostilbene-2,2’-disulfonic acid) also interferes with the L-induced stimulation of respiration. Thus L entry in TAL appears to be directly or indirectly coupled to the transepithelial flux of Cl-. Furosemide (F) but not amiloride, also inhibits this stimulation suggesting that the accelerated Na+ entry triggered by the application of L occurs through the F-sensitive carrier or that lactate transport is F-sensitive in TAL cells. In accord, F specifically impairs the metabolism of L (as compared to G). These data suggest that in intact TAL tubules both lactate uptake and oxidation are directly or indirectly influenced by the transcellular flux of NaCl. This organization may participate to maintain a stoichiometry between the transport of NaCl and the availability of L to support the energetic needs of TAL cells.
Kinetics of Glucose Decarboxylation in the Substrate-Limited Isolated Perfused Kidney
Authors: Anaizi Nasr H. , Cohen† Julius J.
Published: November 2008

Rat kidneys were perfused with a cell-free perfusate containing substrate-free albumin, different glucose concentrations (0.20–5.0 mmol/l), and uniformly labeled 14C-glucose. The rate of glucose decarboxylation (Qox), as a function of [glucose]p, displayed saturation kinetics [Vmax = 0.35 µmol/(g · min); Km = 0.87mmol/l]; saturation occurred at [glucose]p = 1.0–2.0mmol/l. Although the presence of as low as 0.2mmol/l of glucose significantly increased fractional sodium reabsorption (%TNa), there was no correlation between [glucose]p or Qox and %TNa. However, free water clearance (CH2O or CH2O/GFR) was directly proportional to [glucose]p and independent of Qox. We conclude that (1) in the absence of other substrates, renal glucose Qox saturates at hypoglycemic levels of glucose and (2) glucose plays an important role in the generation of solute-free water, a role that is unrelated to glucose Qox.
Influence of Intrarenally Generated Angiotensin II on Renal Hemodynamics and Tubular Reabsorption
Authors: Mitchell Kenneth D. , Navar Gabriel
Published: November 2008

There is growing recognition that angiotensin II (ANG II) formed intrarenally exerts direct effects on renal hemodynamics and tubular reabsorption. In vivo micropuncture experiments performed in anesthetized rats have shown that peritubular capillary infusion of either ANG II or angiotensin I (ANG I), at rates that do not markedly influence baseline vascular resistance, can increase proximal tubular reabsorption rate and enhance the responsiveness of the tubuloglomerular feedback mechanism. With higher ANG II or ANG I infusion rates, pronounced preglomerular vasoconstriction occurs, resulting in reduced glomerular capillary pressure and single nephron glomerular filtration rate. The effects of peritubular capillary infusion of ANG I on glomerular function have been shown to be inhibited by the ANG II receptor antagonist, saralasin, indicating that the observed effects of ANG I on proximal tubular reabsorption and glomerular function are not due to direct effects of the decapeptide but are mediated by increases in the interstitial ANG II concentrations resulting from intrarenally generated ANG II. Interestingly, neither peritubular capillary infusion nor systemic administration of large doses of the angiotensin-converting enzyme (ACE) inhibitor, enalaprilat, elicited significant blockade of the single nephron hemodynamic responses to peritubular infusion of ANG I. These findings indicate that intrarenal conversion of ANG I to ANG II occurs, at least in part, at a site which is inaccessible to acutely administered ACE inhibitors, or that there is an alternative pathway for the intrarenal conversion of ANG I to ANG II that is not blocked by ACE inhibitors.
Role of Ionic Currents in the Physiological Response to Angiotensin II
Authors: Palant Carlos E. , Ross Margery J.
Published: November 2008

Studies using conventional and patch-clamp microelectrode techniques demonstrate that in a number of cell types angiotensin II (All) causes reversible changes in transmembrane ionic currents, and that these effects can be mimicked by various membrane-associated and cytosolic messengers. All modulates the current amplitude of ion channels, as well as their activation threshold and their open/closed time probability. Stimulatory and inhibitory effects on ion channel activity are a fundamental feature of the development of All actions on target organs.
Renal Argininosuccinate Synthetase: Purification, Immunohistochemical Localization, and Elastin-Binding Property
Authors: Wakui Hideki , Komatsuda Atsushi , Itoh Hideaki , Kobayashi Ryoji , Nakamoto Yasushi , Miura Akira B.
Published: November 2008

Several proteins interact with elastin, an essential extracellular matrix element. We describe here an additional elastin-binding protein from the porcine kidney. This protein was extractable with an isotonic buffer, and was purified by a rapid and simple procedure employing its characteristic properties: high affinity for red A-agarose and spontaneous formation of cryoprecipitate. Immunohistochemical studies using antibody against the purified protein demonstrated its localization in the cytoplasm of proximal tubules of the normal rat kidney. On Western blotting using the antibody, an immunoreactive protein was detected in the liver as well as in the kidney. On the basis of the partial amino acid sequences of the purified protein, it was identified as argininosuccinate synthetase. Some biochemical properties of the protein were different from the data reporting a hepatic form of argininosuccinate synthetase, a key enzyme in the urea cycle in the liver. These results suggest that the elastin-binding property of a renal form of the enzyme may be related to a tissue-specific function in the kidney.
Specific Binding Site for Pro Atrial Natriuretic Factors 1-30, 31-67, and 99-126 on Distal Nephrons, Proximal Tubules, Renal Cortical and Medullary Membranes
Authors: Vesely David L. , Sallman Alan L. , Bayliss John M.
Published: November 2008

Two peptides with natriuretic and diuretic properties consisting of amino acids(a.a.)1-30and31-67ofthe98a.a.N-terminalendoftheprohormone of atrial natriuretic factor (proANF), which normally circulates in humans and animals, were investigated to determine if they have specific binding sites on distal nephrons, proximal tubules, renal cortical and medullary membranes. Competitive binding experiments revealed that proANFs 1-30, 31-67, and 99-126 (i.e., C-terminus; ANF) each had specific and separate binding sites. The dissociation constants (Kd) for proANFs 1-30, 31-67, and 99-126 binding to renal cortical membranes were similar at 9.8, 5.1, and 4.7 nM, respectively. In renal medullary membranes on the other hand, proANF 1-30 (Kd = 3.7 nM) and proANF 31-67 (Kd = 2.9 nM) had a 10-fold higher binding affinity than ANF (Kd = 56 nM). All three peptides had very weak binding to proximal tubules with the respective Kds for proANF 1-30, proANF31-67, and ANF of 892,789, and550 nM indicating a 50- to 100-fold less affinity for their binding sites in proximal tubules than in distal nephrons (Kds of 4.9,5.3, and 11 nM, respectively). Each peptide bound to the respective kidney membranes or tubules between 10-8 and 10-7M but could only bind to the other peptides’ receptors at concentrations of 10-6 and 10-7M. Neither insulin, growth hormone, nor adrenocorticotrophic hormone competitively inhibited the binding of proANF 1-30, proANF 31-67 or ANF. These results suggest that proANF 1-30 and proANF 31-67 do not work through the ANF receptor but rather have their own separate and distinct receptors to mediate their diuretic and natriuretic effects in the kidney.
Antigenic Changes of the Glomerular Basement Membrane after Incorporation of Hydroxyproline Isomers
Authors: Lubec B. , Vycudilik W. , Mallinger R. , Häusler J. , Popow C. , Lubec G.
Published: November 2008

We investigated antigenic changes of murine glomerular basement membrane (GBM) collagen type IV after oral feedings of 3-cis- or 4- cis -hydroxyproline. As shown by thin layer chromatography and gas chromatographic-mass spectrometric studies, 3-cis- and 4- cis -hydroxyproline were incorporated into the GBM collagen instead of the normal trans isomer and led to a considerable reduction of the collagen antibody reactivity on indirect immunofluorescence, passive hemagglutination and radioimmunoassay when compared to GBM collagen of control animals. We speculate that antigen modification due to the incorporation of stereoisomers could serve as a model for basement membrane immunopathology.
Renal Handling of Sodium after an Oral Protein Load in Adult Humans
Authors: DeSanto Natale G. , Capasso Giovambattista , Anastasio Pietro , Coppola Salvatore , DeTommaso Giannantonio , Coscarella Giulia , Bellini Luigi , Spagnuolo Giuliano , Barba Gianvincenzo , Lombardi Attilio , Alfieri Raffaele , lacone Roberto , Strazzullo Pasquale
Published: November 2008

This investigation was designed to study (1) renal sodium handling after an oral protein load and (2) its relationship to some known determinants of the hemodynamic response (glucagon, insulin, growth hormone, renin, aldosterone, and plasma amino acid concentration). To this end of group of 8 adult subjects was studied before (three 30-min clearances) and after a meat meal (MM; five 30-min clearances at 30, 60, 90,120 and 180 min). The MM provided 2 g/kg BW of protein. Within 30 min from the MM an hyperfiltration response was seen, which was paralleled by a 2-fold increase in plasma alanine concentration while total plasma amino acid concentration was not different from the baseline values. The hemodynamic response was associated with a normally operating tubuloglomerular feedback mechanism independent of renin-aldosterone activity, but possibly associated with an early increase in plasma glucagon concentration and later on with a modest increase in postmeal plasma insuling concentration.
Intranephron Distribution of Glycine-Amidinotransferase Activity in Rats
Authors: Takeda Michio , Koide Hikaru , Jung Kyu Yong , Endou Hitoshi
Published: November 2008

Guanidinoacetic acid (GAA), a precursor of creatine, is an essential substrate for muscle energy metabolism, and synthesized by glycine-amidinotransferase (transamidinase) mainly in the kidney. Since the intranephron distribution of transamidinase activity has never been quantified yet, the purpose of this study is to provide evidence about the localization of transamidinase activity using microdissected individual nephron segments. Synthesized GAA was separated by HPLC and detected fluorometrically after reacting with 9,10-phenanthrenequinone. Results obtained were as follows. (1) Transamidinase activity was distributed only in the first (S1) and the second (S2) portion of the proximal tubule Si being significantly higher than S2. (2) In S2, arginine and glycine were better substrates for GAA synthesis than canavanine and glycine. These results clearly indicate that GAA is synthesized in definite portions of the proximal tubule, and would be transported to the liver for further creatine production.
In vitro Autoradiography Reveals Predominantly AT1 Angiotensin II Receptors in Rat Kidney
Authors: Zhuo Jialong , Song Keifu , Harris Peter J. , Mendelsohn Frederick A.O.
Published: November 2008

Angiotensin II (Ang II) receptor subtypes in the rat kidney were investigated by using type 1 (AT1) and type 2 (AT2) Ang II receptor antagonists to discriminate specific 125I-[Sar1, Ile8] Ang II binding sites with in vitro autoradiography. DuP 753, a nonpeptide Ang II antagonist specific for the AT1 sites, potently displaced binding in glomeruli (Ki = 23.9 ± 3.3 nM) and proximal tubules (Ki = 43.4 ± 17 nM). By contrast, the AT2 antagonists, PD 123177 and CGP 42112A, were very weak in competing for specific 125I-[Sar1, Ile8] Ang II binding sites. AT1 receptors, as determined in the presence of an excess concentration (10 µM) of the AT2 antagonist, PD 123177, account for 95% of total renal Ang II receptors, whereas AT2 receptors, as determined in the presence of an excess concentration (10 µM) of the AT1 antagonist, DuP 753, represent approximately 5% of total 0renal Ang II receptors. In addition, the reducing agent, dithiothreitol, produces a dose-dependent inhibition of Ang II receptor binding with an IC50 of 2 mM, a characteristic of the AT1 receptors. These findings indicate that the AT1 receptor is the predominant subtype at multiple anatomical sites in the rat kidney.
On the Glomerular Mechanism of the Renal Protein Excretion
Authors: Pagel Horst , Stolte Hilmar
Published: November 2008

The glomerular permeability of the isolated perfused kidney is manifold higher than in vivo, although structural changes at the glomerular filtration barrier are not described. It has been proposed that in vivo high molecular weight plasma proteins are concentrated at the glomerular endothelium forming an additional filtration barrier (‘concentration polarization’). To test this hypothesis, isolated rat kidneys were perfused with substrate-enriched Krebs-Henseleit solutions containing albumin (50 g/l) or albumin/globulin (40/10 g/l), or with plasma. The pO2 was 675 mm Hg. Furthermore experiments were carried out with the addition of erythrocytes with and without a reduced 02 supply (pO2 35 mmHg). Independent of the composition of the perfusate a continuously increasing glomerular permeability was observed immediately after perfusion was started. After about 10 min, a steady state value for the glomerular permeability was reached. The addition of globulin to the perfusate or perfusion with plasma did not prevent the initial increase of the permeability. However, after addition of 5% erythrocytes to the perfusate the increase of permeability was much less pronounced. Neither the reduction of the O2 supply nor the addition of erythrocytes to a higher concentration than 5% had any further effect on the glomerular permeability. These data show that concentration polarization of high molecular weight proteins does not take place at the endothelium of the glomerulus. Independent of their ability to carry O2 erythrocytes play an important role in the glomerular filtration process.
Tumor Necrosis Factor-α- and lnterleukin-1-Stimulated Intercellular Adhesion Molecule-1 Expression by Murine Renal Tubular Epithelial Cells Is Transcriptionally Regulated and Involves Protein Kinase C
Authors: Wuthrich Rudolf P.
Published: November 2008

The regulation of intercellular adhesion molecule-1 (ICAM-1) expression by renal tubular epithelial cells (TEC) has been studied in vitro. ICAM-1 expression in TEC is stimulated with phorbol 12-myristate 13-acetate (PMA), but not with forskolin, suggesting a role for protein kinase C (PKC) but not for protein kinase A (PKA). The tumor necrosis factor-Α- (TNF-Α) and interleukin-1 (IL-1)-stimulated ICAM-1 expression in TEC is blocked with the PKC/PKA inhibitor staurosporine, and also with the PKC-selective inhibitor calphostin C. The TNF-Α-stimulated ICAM-1 expression is resistant however to downregulation of PKC with PMA. The TNF-Α- and IL-1-stimulated ICAM-1 expression is also inhibited with the transcriptional inhibitor actinomycin D and with the protein synthesis inhibitor cycloheximide. Thus, ICAM-1 expression by TEC may involve a downregulation-resistant PKC which induces ICAM-1 expression at a transcriptional level.
Evolving Applications for Patient-Centered Health Status Measures
Authors: Spertus John A.
Published: November 2008

Patient-centered health status measures—assessments of patients’ symptoms, function, and quality of life—have matured substantially over the past 2 decades. Currently, valid, reliable, and sensitive disease-specific measures are available for quantifying the health status of patients with cardiovascular disease. This article briefly reviews the concept of health status measures, with a focus on their interpretation. It then discusses both the rationale and potential applications of health status measures in clinical care. Health status measures are not surrogate measures of outcome but rather highly meaningful outcomes of care. As such, they have important emerging roles as outcomes in clinical trials, as tools for monitoring patients in routine clinical care, as a mechanism for operationalizing and evaluating disease management programs, and as tools for quality assessment/improvement. Over time, it is expected that health status measures will also have an increasingly important role in patient-centered medical decision making. By becoming aware of the evolving roles of health status measures, clinicians can help to accelerate the realization of the Institute of Medicine’s vision for a more transparent, evidence-based, patient-centered healthcare system.
Study of a Group of Extremely Preterm Infants (25—27 Weeks)
Authors: Samsom Janny F. , de Groot Laila
Published: November 2008

The functional outcome of 49 extremely preterm infants (gestational age: 25—27 weeks) was studied at the corrected age of 12 months. Apart from pediatric follow-up, a full neurologic assessment and the Bayley Motor and Mental Scales of Infant Development was done. Emphasis was placed on postural control, spontaneous motility, hand function, and elicited infantile reactions. Special attention was given to symmetric development. The infants were then categorized as having optimal or nonoptimal or asymmetric outcome. Overall, an optimal outcome was found in 19 infants (39%) and nonoptimal outcome in 30 infants (61%), 7 of whom failed on all domains of function. Postural control had a significant influence on the different domains of development such as motility ( P ≤ .001) and persistent infantile reactions ( P ≤ .001) and slightly less on hand function ( P = .08) and asymmetry ( P = .06). The outcome on spontaneous motility was significantly related to the results on infantile reactions ( P ≤ .005) and hand function ( P = .05). Also, the score on the motor scale of the Bayley Developmental test was clearly related to outcome on spontaneous motility ( P ≤ .001) and reactions ( P ≤ .02). Abnormal brain ultrasonograms were related to the asymmetry of the infantile reactions ( P ≤ .05). Poor coordination of gross motor function will have consequences for appropriate visuomotor and sensorimotor integration, thereby hampering motor learning and later cognitive function, as is often described in preterm infants. It is suggested that the poor postural control found in many infants born preterm is the result of both myogenic and neurogenic deviations caused by the preterm birth and its nursing consequences. ( J Child Neurol 2001;16:832—837).
Prenatal Intracranial Hemorrhage and Neurologic Complications in Alloimmune Thrombocytopenia
Authors: Sharif Uzma , Kuban Karl
Published: November 2008

Neonatal alloimmune thrombocytopenia results from platelet-antigen incompatibility between mother and fetus, leading to antibody-mediated destruction of fetal platelets. With a prevalence of 1 in 1000 births, approximately 4000 infants born in the United States each year develop neonatal alloimmune thrombocytopenia. Ten to 20% of affected neonates develop intracranial hemorrhage, with 25 to 50% occurring prenatally. We report three infants who developed prenatal hemorrhage. One died in utero, and the other two had cerebral porencephaly and neurologic deficits. Infants with neonatal alloimmune thrombocytopenia have elevated risks of perinatal death and neurologic complications, including cerebral palsy, hypotonia, cortical blindness, developmental delay, seizures, and psychomotor retardation. We also report our retrospective review of the New England Medical Center neonatal intensive care unit between 1990 and 1999. Using current management guidelines, including treatment of the mother with a weekly infusion of high-dose (1—2 g/kg) intravenous immunoglobulin and/or corticosteroids, all eight infants with neonatal alloimmune thrombocytopenia did well. ( J Child Neurol 2001;16:838—842).
NeuroD Homologue Expression During Cortical Development in the Human Brain
Authors: Franklin Allyn , Kao Anna , Tapscott Stephen , Unis Alan
Published: November 2008

Neurogenesis and neuronal differentiation are determined by the NeuroD homologues, transcription factors belonging to a family of basic helix-loop-helix proteins. The authors used in situ hybridization with full-length riboprobes for NeuroD1, NeuroD2, and NeuroD3 to describe the expression of the NeuroD homologues in a gestational sequence of human fetal brains. Acridine orange histofluorescence was used to differentiate neuronal from non-neuronal cell precursors. At the earliest gestational age examined (gestational week 16), signals for all three homologues could be identified but that for NeuroD3 was most intense. Peak expression of NeuroD1 and NeuroD2 followed at gestational weeks 19 and 20, respectively. Although similar to the expression of these homologues in the mouse cerebrum, notable differences were observed. Specifically, signals for all three homologues were detected in the marginal zone and the ventricular zone, including the ganglionic eminence. The temporal order of expression in the human is similar to that in the mouse, in spite of these anatomic differences. These data are consistent with NeuroD3 serving as a determination factor, which commits the postmitotic progenitor cell to a neuronal fate, whereas NeuroD1 and NeuroD2 appear more likely to play a role in neuronal differentiation. ( J Child Neurol 2001;16:849—853).
Activated Protein C Resistance and False Type 2 Protein C Deficiency Detected After Multiple Shunt Failures in a Patient With Hydrocephalus
Authors: Kayiran Sinan Mahir , Özbek Namik , Tokel Kürsat , Mercan Sükrü , Alehan Fusun
Published: November 2008

A 2-year-old hydrocephalic boy who had suffered multiple shunt failures was evaluated for hypercoagulability after a thrombus was removed from his right atrium. The work-up revealed that the patient had the heterozygous form of activated protein C resistance and false type 2 protein C deficiency by the clotting method. His protein C activity was normal by the chromogenic method. We suggest that patients having hydrocephalus, shunt-associated thrombus formation, or both should be evaluated for thrombophilic disorders, and protein C activity should be measured by chromogenic assay in patients with documented activated protein C resistance. ( J Child Neurol 2001; 16:862-863).
Enteroviral Encephalitis Leading to a Locked-in State
Authors: Acharya Victoria Z. , Talwar Dinesh , Elliott Sean P.
Published: November 2008

Millions of children are infected by enteroviruses each year, usually exhibiting only mild symptoms. Although enteroviruses are a common cause of community-acquired aseptic meningitis, enteroviral meningitis usually has a benign course. We describe a 14-year-old patient with enteroviral meningoencephalitis diagnosed by polymerase chain reaction. Her level of consciousness declined rapidly after hospital admission and resulted in a locked-in state. Although she experienced slow neurologic improvement, residual neurologic deficits remain. Although there is a general awareness of the characteristics of enteroviral encephalitis, this case report is significant in presenting a case of unusual severity and sequelae. To our knowledge, this is the first published report of an enterovirus encephalitis leading to a locked-in-state. ( J Child Neurol 2001;16:864—866).
The South African Experience: Beyond the CIDA Model
Authors: Bruton John M.
Published: November 2008

The Community and Individual Development Association (CIDA) City Campus is presented by Heaton as an innovative African alternative to traditional business education. However, he considers the model in isolation from the unique educational and economic circumstances of postapartheid South Africa. As a response, this article goes beyond the CIDA model to consider the effect of the unique circumstances in South Africa on the formation and success of the CIDA City Campus. It then considers the elements of the CIDA model to examine whether they are radical innovations, as Heaton claims, or extensions of accepted theory and practice. The purpose of this is not to discredit the CIDA model. Rather, this article supports the model by showing that it is well grounded in accepted pedagogy. It concludes by considering whether CIDA provides a model for business education in developing countries or whether it is uniquely suited to the unique conditions in South Africa.
Mesenteric Venous Thrombosis With Bowel Infarction and Hyperhomocysteinemia Due to Homozygous Methylenetetrahydrofolate Reductase C677T Genotype
Authors: Hotoleanu Cristina , Andercou Octavian , Andercou Aurel
Published: November 2008

The case of a 30-year-old man with bowel infarction due to mesenteric venous thrombosis and multiple risk factors, including mild hyperhomocysteinemia due to methylenetetrahydrofolate reductase C677T polymorphism and recent abdominal surgery, is reported. His clinical manifestation consisted of persistent abdominal pain; complementary examinations showed nonspecific findings such as leukocytosis and dilated loops of the bowel. The diagnosis of mesenteric venous thrombosis with bowel infarction was made during laparotomy and confirmed by anatomopathologic examination. He underwent segmental resection associated with lifelong anticoagulant therapy and vitamin B supplementation with a favorable course.
Mobile Thrombus of the Thoracic Aorta: Management and Treatment Review
Authors: Piffaretti Gabriele , Tozzi Matteo , Mariscalco Giovanni , Bacuzzi Alessandro , Lomazzi Chiara , Rivolta Nicola , Carrafiello Gianpaolo , Castelli Patrizio
Published: November 2008

Detection of mobile thrombus of the thoracic aorta has become increasingly higher after any embolic event. Although the indication for treatment remains controversial, there is a growing interest about the ethiopathogenesis of this rare entity, and to define proper diagnostic and therapeutic approaches. The purpose of this article was to review the current management strategies and follow-up results of this rare pathology.
New Synthesis of 1,2-Thiazetidines of anti- and syn-9,9′-Bibenzonorbornenylidenes
Authors: Sugihara Yoshiaki , Takeda Ken-ichi , Zhao Jin , Aoyama Yui , Okuda Harunori , Nakayama Juzo
Published: November 2008

1,2-Thiazetidines 2 and 3 were synthesized by the reactions of anti- and syn-9,9′-bibenzonorbornenylidenes with TsNSO, followed by deimination with SmI2. Heating 2 and 3 neat produced a mixture containing aziridines, thiiranes, and alkenes.
In-cell Viscosity Measurement Using a Fluorescence Up-conversion Microscope
Authors: Fujino Tatsuya , Hirota Kouji , Ohta Kunihiro , Tahara Tahei
Published: November 2008

Using a femtosecond fluorescence up-conversion microscope, viscosity values in yeast cells (budding, wine, and fission) were estimated based on ultrafast fluorescence dynamics of a fluorescent probe dye, Malachite Green. The decay time of the S1 state of Malachite Green in cytoplasm was determined to be 2.2–2.4 ps at room temperature, which corresponded to the viscosity value of 5–6 cP. Nondestructive estimation of viscosity value in cells (in-cell viscosity) was carried out.
Silylcarbene-to-Silene Rearrangement: Stable 1,2-Dihydrosilenes in Solution via the Silylcarbene Route
Authors: Tanaka Hiroaki , Ichinohe Masaaki , Sekiguchi Akira
Published: November 2008

1,2-Dihydrosilenes were synthesized by the photolysis of silyldiazomethane derivatives bearing one bulky trialkylsilyl group SiR[CH(SiMe3)2]2 (R=Me and i-Pr) and two hydrogen atoms on the silicon atom. The selective migration of the hydrogen atom to the carbene center occurred, leading to stable trans-1,2-dihydrosilenes, which were characterized by their spectroscopic data. An X-ray analysis of the Diels–Alder adduct demonstrated the trans geometry of the 1,2-dihydrosilene.
Organic thin-film transistors of phthalocyanines
Authors: Li Liqiang , Tang Qingxin , Li Hongxiang , Hu Wenping , Yang Xiaodi , Shuai Zhigang , Liu Yunqi , Zhu Daoben
Published: November 2008

Organic thin-film field-effect transistors (OTFTs) are emerging as attractive candidates for low-price, large-area, and flexible circuit applications. A variety of organic compounds have been utilized as active semiconductor materials for OTFTs, among which phthalocyanine compounds have attracted considerable attention owing to their remarkable chemical and thermal stability as well as good field-effect performance. Here, we review recent results on the phthalocyanine-based OTFTs. The correlation between the crystal packing structure and the charge transport property is discussed, and we conclude with a description of the future prospects for phthalocyanine-based OTFTs.
Development of biodegradable nanosheets as nanoadhesive plaster
Authors: Takeoka Shinji , Okamura Yosuke , Fujie Toshinori , Fukui Yoshihito
Published: November 2008

Sheet-shaped carriers having both obverse and reverse surfaces (thus, a large contact area for targeting a site and adhesive properties without any chemical cross-linker onto tissue surface) have several advantages as surgical dressings. These advantages include active targeting over spherically shaped carriers, which thus have an extremely small contact area for targeting sites. Here, we propose a novel methodology for preparation of a free-standing, ultra-thin, and biocompatible polymer nanosheet having heterosurfaces, fabricated through macromolecular assembly. In the context of biomedical applications, the targeted properties include injectable sheet-shaped drug carriers having precisely controlled size by exploiting micropatterned substrate, and giant polymer nanosheets composed of biocompatible polysaccharides. A huge aspect ratio, in excess of 106, is particularly applicable for novel surgical dressings. These biocompatible polymer nanosheets having heterosurfaces can thus be regarded as new biomaterials for minimally invasive treatment.
Single-chain magnets constructed with a twisting arrangement of the easy-plane of iron(II) ions
Authors: Kajiwara Takashi , Tanaka Hiroki , Yamashita Masahiro
Published: November 2008

A novel class of single-chain magnets (SCMs), catena-[FeII(ClO4)2{FeIII(bpca)2}]ClO4 and its derivative, were synthesized using the spin-carrier components possessing hard-axis anisotropy (or easy-plane anisotropy, D > 0). The easy-axis-type anisotropy of whole molecules of these compounds, which is essential for the formation of SCMs, arises from the twisted arrangement of easy-planes of Fe(II) along the chain axis. Alternating high-spin Fe(II) and low-spin Fe(III) chain complexes behave as an SCM with a typical frequency-dependent ac susceptibility which obeys Arrhenius law. Below 7 K, catena-[FeII(ClO4)2{FeIII(bpca)2}]ClO4 showed a short-range spin-ordering even in zero external field in a time range of Mössbauer spectroscopy as well as the muon-spin-relaxation (μSR) spectroscopy. Since the easy-axis-type magnetic anisotropy originated from the structural motif of the twisting arrangement of Fe(II) ions, the overall magnetic property was very sensitive to the small structural changes arising from adsorption/desorption of the crystal solvents, and catena-[FeII(ClO4)2{FeIII(bpca)2}]ClO4 showed a reversible change in magnetism that has been referred to as "a magnetic sponge". In its derivative, controls of the molecular structure, the arrangement of chains in the crystal, and magnetic properties both in dc and ac susceptibility have been achieved by the introduction of methyl group on a bpca- ligand, which bridges and mediates the magnetic interaction of the adjoining Fe(II)/Fe(III) ions.
Organic field-effect transistors based on tetrathiafulvalene derivatives
Authors: Gao Xike , Qiu Wenfeng , Liu Yunqi , Yu Gui , Zhu Daoben
Published: November 2008

In recent years, tetrathiafulvalene (TTF) and its derivatives have been used as semiconducting materials for organic field-effect transistors (OFETs). In this review, we summarize the recent progress in the field of TTF-based OFETs. We introduce the structure and operation of OFETs, and focus on TTF derivatives used in OFETs. TTF derivatives used in OFETs can be divided into three parts by the semiconductor's morphology and the device fabrication technique: (1) TTF derivatives used for single-crystal OFETs, (2) TTF derivatives used for vacuum-deposited thin-film OFETs, and (3) TTF derivatives used for solution-processed thin-film OFETs. The single-crystal OFETs based on TTF derivatives were fabricated by drop-casting method and showed high performance, with the mobility up to 1.4 cm2/Vs. The vacuum-deposited thin-film OFETs based on TTF derivatives were well developed, some of which have shown high performance comparable to that of amorphous silicon, with good air-stability. Although the mobilities of most solution-processed OFETs based on TTF derivatives are limited at 10-2 cm2/Vs, the study on solution-processable TTF derivatives and their devices are promising, because of their low-cost, large-area-coverage virtues. The use of organic charge-transfer (OCT) compounds containing TTF or its derivatives in OFETs is also included in this review.
Novel strategies for preparation and characterization of functional polymer-metal nanocomposites for electrochemical applications
Authors: Muraviev Dmitri N. , Ruiz Patricia , Muñoz Maria , Macanás Jorge
Published: November 2008

Stabilization of metal nanoparticles (MNPs) in polymeric matrices of different types has proven to be one of the most promising strategies to prevent their aggregation and to retain their properties. Polymer-stabilized MNPs (PSMNPs) and those based on polymer-metal nanocomposite materials are starting to find wide application in various fields of science and technology. In this paper, we demonstrate that metal-polymer nanocomposite membranes (MPNCMs) containing MNPs can easily be prepared in an ion-exchange such as, for example, sulfonated polyetherether ketone (SPEEK) matrix by using the polymeric membranes as nanoreactors for synthesis and to characterize the composition and structure of the formed MNPs. Metal ions (or metal ion complexes) are first incorporated into the polymeric matrix where they undergo reduction, leading to formation of corresponding MPNCMs. Since this technique allows successive metal loading-reduction cycles to be carried out, it enables synthesis of both monometallic and bimetallic (e.g., core-shell) MNPs. The proposed approach is illustrated by synthesis and characterization of MPNCMs containing both monometallic and bimetallic core-shell MNPs, formed by combinations of Pd, Pt, Co, Ni, and Cu, along with their application in electrochemical sensor and biosensor constructions.
In situ transient study of polymer film growth via simultaneous correlation of charge, mass, and ellipsometric measurements
Authors: Svoboda Vojtech , Liaw Bor Yann
Published: November 2008

Using three synchronized, in situ, nonintrusive, real-time characterization techniques to conduct transient observations, we revealed mechanistic details of a polymer film growth. A thin methylene green (MG) polymer coating (of the order of 35 nm) was used as a model system in this electrochemical microgravimetric imaging ellipsometry (EmIE) investigation. The direct correlation of changes in mass (via quartz crystal microbalance, QCM), ellipsometric angles (via imaging ellipsometry) with electrochemical conditions (in cyclic voltammetry, CV) provides discrete temporal and spatial information to help us decipher the underlying steps, from which we were able to separate adsorption, reduction, oxidation, desorption, and polymerization regimes involved in the deposition process. The evidence revealed in this study could have broad impact on the general understanding regarding how a film is deposited onto a metal surface.
The Structure of Survey-Based Brand Metrics
Authors: Lehmann Donald R. , Keller Kevin Lane , Farley John U.
Published: November 2008

To better understand how a brand is performing in the marketplace, firms employ a wide variety of measures, with consumer-based surveys often playing a central role. The authors identify some core dimensions of survey-based measures of brand performance, explore how they link to one another, and examine how they vary across both countries and categories. Studies in the United States and China of soft drinks, toothpaste, and fast food suggest that survey-based brand metrics can be categorized into six main dimensions that reflect a four-stage, hierarchy-of-effects awareness–interest–desire–action–type ordering: (1) comprehension; (2) comparative advantage, interpersonal relations, and history; (3) preference; and (4) attachment. Despite differences in culture and their history, these dimensions usefully portray different brands and products across the different countries.
Interrupted Consumption: Disrupting Adaptation to Hedonic Experiences
Authors: Nelson Leif D. , Meyvis Tom
Published: November 2008

Six studies demonstrate that interrupting a consumption experience can make pleasant experiences more enjoyable and unpleasant experiences more irritating, even though consumers avoid breaks in pleasant experiences and choose breaks in unpleasant experiences. Across a variety of hedonic experiences (e.g., listening to noises or songs, sitting in a massage chair), the authors observe that breaks disrupt hedonic adaptation and, as a result, intensify the subsequent experience.
Who's Got the Coupon? Estimating Consumer Preferences and Coupon Usage from Aggregate Information
Authors: Musalem Andrés , Bradlow Eric T. , Raju Jagmohan S.
Published: November 2008

Most researchers in marketing have typically relied on disaggregate data (e.g., consumer panels) to estimate the behavioral and managerial implications of coupon promotions. In this article, the authors propose the use of individual-level Bayesian methods for studying this problem when only aggregate data on consumer choices (market share) and coupon usage (number of distributed coupons and/or number of redeemed coupons) are available. The methodology is based on augmenting the aggregate data with unobserved (simulated) sequences of choices and coupon usage consistent with the aggregate data. The authors analyze various marketing scenarios that differ in terms of their assumptions about consumer choices, coupon availability, and coupon redemption. They illustrate the proposed methods using both simulated data and a real data set for which an extensive set of posterior predictive checks helps validate the aggregate-level estimation. In addition, the authors relate the empirical results to some of the findings in the literature about the coordination of coupon promotions and pricing and show how the methodology can be used to evaluate alternative coupon targeting policies.
Ultrastructural development of the softwood cell wall during pyrolysis
Authors: Zollfrank Cordt , Fromm Jörg
Published: November 2008

The pyrolytic conversion of pine wood at mild temperatures between 200°C and 300°C was investigated by transmission electron microscopy (TEM). Based on TEM imaging and image analysis, a novel method was developed for determining the local orientation of the cellulose microfibrils in the secondary wall S2 which gives a measure for the progression of pyrolytic conversion of the cell wall. Elemental composition of pyrolysed specimens was determined up to 600°C. TEM imaging together with the evaluation of the elemental composition shows that first the polyoses are degraded, while the cellulose microfibril orientation is still visible up to 225°C. The cellulose microfibrils could not be observed at temperatures higher than 250°C, while lignin containing compound middle lamella (CML) was still visible. After a gradual decrease of the CML up to 275°C, the cell wall became entirely isotropic beginning at 300°C. Based on the presented results, we propose an early degradation of the supramolecular structure of the cell wall.
Parasitic and Phoretic Mites Associated with Neotropical Harvestmen from Trinidad, West Indies
Authors: Townsend Victor R , Proud Daniel N , Moore Michael K , Tibbetts Jessica A , Burns Jessica A , Hunter Rebecca K , Lazarowitz Suzanne R , Felgenhauer Bruce E
Published: November 2008

Larval erythraeid mites are common ectoparasites of harvestmen (Opiliones). However, interactions between these mites and hosts in tropical environments have received little attention. In this study, we examined the prevalence and intensity of mite infestations for Neotropical harvestmen from the Caribbean island of Trinidad. Overall, the prevalence of infestation was 9.9%, with significant interspecific variation in the intensity of mite infestation and significant differences in parasitism of hosts between habitats. Harvestmen collected from lowland, crappo-cocorite forest exhibited the highest infestation rates. In our samples, the intensity of infestation varied from 1 to 17 mites per host. Examination by scanning electron microscopy revealed that harvestmen were infested by two taxa of mites, a species of Leptus and another unidentified erythraeid species. Our observations represent the first host records for erythraeid mites parasitizing harvestmen from the families Cranaidae and Manaosbiidae. Mites were found to attach preferentially to the tibia and femur of the leg (175 of 178 observations). In general, the harvestmen of Trinidad exhibited mite parasitism in a fashion similar to temperate species with respect to site of attachment and prevalence and intensity of mite infestation. In the field, we also collected an adult Cynortula sp. (Cosmetidae) that was transporting 30 gravid adults of an oribatid mite (Acariformes, Oribatida, Mixonomata). Cases of mite phoresy upon harvestmen are rare, with our observation representing the first report of phoresy by an oribatid mite upon a harvestman and the first documentation of mite phoresy upon harvestmen in the Caribbean.
Behavioral Responses ofAedes albopictusto a Predator Are Correlated with Size-Dependent Risk of Predation
Authors: Kesavaraju Banugopan , Juliano Steven A
Published: November 2008

The invasive container-dwelling mosquito Aedes albopictus (Skuse) shows modest behavioral responses to water-borne cues from predatory Corethrella appendiculata Grabham in North America. We investigate whether Ae. albopictus adjust their antipredatory responses to be proportional to size-dependent risk of predation. Fourth-instar Ae. albopictus attain a size refuge from C. appendiculata predation, and we compared the responses of second- and fourth-instar Ae. albopictus to cues from C. appendiculata predation. More vulnerable second-instar larvae showed a larger change in behavior in response to predation cues than did less vulnerable fourth-instar larvae, indicating threat-sensitive behavioral responses by Ae. albopictus.
Mitochondrial Phylogeny of Cryptic Species of the Lacewing Chrysoperla nipponensis (Neuroptera: Chrysopidae) in Japan
Authors: Haruyama Naoto , Naka Hideshi , Mochizuki Atsushi , Nomura Masashi
Published: November 2008

We surveyed a 1,033-bp fragment of the cytochrome oxidase subunit I (COI) sequence to look for a useful diagnostic marker for discrimination between the Japanese cryptic species Chrysoperla nipponensis (Okamoto) (Neuroptera: Chrysopidae) (types A and B) and the commercially introduced Chrysoperla carnea s. str. from Germany. Phylogenetic analysis showed four distinct haplotype groups: one group corresponded to C. nipponensis type B and one group to C. carnea s. str., and the remaining two distinct groups, A1 and A2, corresponded to the same song phenotype, C. nipponensis type A. A2 was linked with the group of C. carnea s. str. and A1 was linked with the group of C. nipponensis type B. Cross-testing between A1 and A2 revealed their reproductive compatibility. Mitochondrial polyphyly within C. nipponensis type A may, therefore, originate from introgression or incomplete lineage sorting. Within the mitochondrial COI region presented here, there were 17 variable nucleotide sites useful for discriminating the four haplotype groups from each other.