bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of 2-Oxoglutarate Concentrations on Canine Slice Ammoniagenesis
Authors: Risquez Alvaro , Gaydos DiAnna Slemmer , Preuss Harry G.
Published: November 2008

The concentration of renal 2-oxoglutarate has been proposed as an important regulator of ammoniagenesis in dog kidneys. In the present study, canine kidney slices produced less ammonia from glutamine and glutamate when 2-oxoglutarate was present in the incubation medium. However, the addition of arsenite, a metabolic blocker known to block 2-oxoglutarate metabolism and lead to its accumulation, overcame 2-oxoglutarate inhibition of ammoniagenesis when glutamine and glutamate were the ammonia precursors. Therefore, metabolism of 2-oxoglutarate, rather than its concentration, governed ammonia production from glutamine and glutamate in incubating dog renal tissue. In contrast to the results with 2-oxoglutarate, inhibition of glutamine ammoniagenesis by glutamate was not overcome by arsenite. The results suggest that renal ammonia adaptation in acidotic dogs cannot be ascribed to a theory based upon 2-oxoglutarate concentrations controlling the direction of the glutamate dehydrogenase pathway (GDH), decreasing glutamine transport, or directly inhibiting GDH enzyme activity.
Kidney Function during Decreased Perfusion Pressure Due to Aortic Clamping and Hemorrhagic Hypotension: A Single Nephron Study in Dog Kidney
Authors: Heller Jiří , Horáček Vladislav
Published: November 2008

Whole kidney and single nephron function was compared in dogs during a stepwise lowering of renal perfusion pressure (PP) induced by aortic clamping (C) or hemorrhagic hypotension (HH). In C, renal vascular resistance (RVR) decreased with decreasing PP, the decrease being due to a drop in afferent resistance (RA) only. HH was associated with a rise in RVR due in the first phase mainly to an increase in RE, later to both RA and RE. There was a decrease in total kidney blood flow (RBF), glomerular filtration rate (GFR), glomerular and peritubular capillary pressure, and proximal tubular pressure. In C, RBF and GFR showed no significant difference at PPs 17 and 13 kPa. However, single nephron pressures were slightly but significantly lowered. In both groups, glomerular capillary hydraulic pressure (GCP) was significantly higher when calculated as SFP + πA (stop flow pressure + systemic arterial plasma oncotic pressure) than when measured directly by puncturing glomerular capillaries after ablation of a small layer of superficial cortex. This difference disappeared at PP 8 kPa. Ultrafiltration coefficient (Kf) seemed to increase with decreasing PP.
Morphological and Statistical Investigation of the Occurrence of ‘Tubule-Like Cells’ in the Renal Corpuscle of the Mouse Kidney Induced by Sex Hormones
Authors: Barberini F. , Familiari G. , Vittori I. , Carpino F. , Metis M.
Published: November 2008

In this report the authors describe the structural and ultrastructural characteristics of some cells constituting the parietal layer of Bowman’s capsule of the mouse kidney, which are very similar to the epithelial cells of the proximal convoluted tubule (tubule-like cells). These elements are noted in mature and immature mice of both sexes, but their fine morphology and statistical incidence seem related to the sex and the age of the mice, as revealed by the different responsiveness of the same animals to sex hormones experimentally administered. Such substances, directly and/or through an influence on gonadotropins (especially luteinizing hormone), are able to modify (mainly increasing) the percentage of renal corpuscles possessing tubule-like cells.
Expression of Plasma Renin Activity in Terms of Urinary Sodium Excretion and Posture in Normal Subjects on Free Sodium Intake
Authors: Wolf J.P. , Henriet M.T. , Nguyen N.U. , Dumoulin G. , Laroze M. , Berthelay S.
Published: November 2008

Supine and upright plasma renin activities (PRA) were measured in 151 normal subjects on free sodium intake. Supine and upright plasma renin activities were then related to the 24-hour urinary sodium or the 2-hour urinary sodium excretion, measured in the morning after overnight fasting. Urinary sodium excretion was expressed as the urinary rate per hour or as the urinary Na/creatinine ratio. Correlations were found between both supine and upright PRA and 2 h urinary sodium excretion expressed as the Na/creatinine ratio. Supine and upright PRA values are expressed in terms of these correlations with confidence intervals.
The Movement of Solutes and Water Across the Vertebrate Distal Nephron
Authors: Stoner Larry C.
Published: November 2008

The similarity (or lack of) of mechanisms for ion and water transport across segments of the distal nephron of the various vertebrate classes is considered. Except for the reptilian distal nephron, the early distal nephrons from vertebrates of different classes appear to share certain morphological and functional characteristics. Among these are a relative impermeability of the tubule to water and the ability to preferentially reabsorb solute. This osmodilution of the luminal contents seems to be attributed to the presence of a sodium-chloride cotransport system located in the lumen membrane. The characteristics of solute and water transport of the late distal tubule are also considered. The available data suggest that there are striking similarities for the solute transport characteristics of the various vertebrate classes which have been studied. On the other hand, not all vertebrates appear to have developed the hydroosmotic response to antidiuretic hormone that has been observed in the mammals.
Renal Excretion of Nitrogenous Compounds in Vertebrates
Authors: King Patricia A. , Goldstein Leon
Published: November 2008

The renal excretion of nitrogenous compounds plays an important role not only in the elimination of nitrogen end-products but also in regulating the acid-base and osmotic balance of body fluids. The major nitrogenous compounds excreted by the vertebrate kidney are ammonia, urea and uric acid. The present review addresses the renal excretion of these compounds and, in addition, the amino acid taurine. The functions of excretion; the mechanisms of excretion including renal metabolism, renal handling (secretion, reabsorption, and filtration), and transepithelial transport processes; and the factors regulating these mechanisms are discussed. Renal nitrogen excretion among the vertebrate classes from fish to mammals is compared.
Isoenzymes of N-Acetyl-β-D-Glucosaminidase in Kidney Cortex and Urine of Normal and Nephritic Rats
Authors: Haga Hans-Jacob , Andersen Knut-Jan
Published: November 2008

Induction of acute Heyman nephritis in rats gave a significant increase in the urinary excretion of protein (p < 0.001) and N-acetyl-β-D-glucosaminidase (NAG; p < O.01) 14 days after injection of antibody. The isoelectric points (IP) of NAG were studied by chromatofocusing of the urine, serum and various lysosomal populations purified from kidney cortex homogenates of normal and nephritic rats. The chromatofocusing profiles for serum NAG (IP = 5.8) were totally different from the patterns found in normal and nephritic urines. The acidic IPs of NAG in normal urine (IP = 5.0) were changed into slightly more basic values in nephritic urine (IP =5.15). Similar changes were also demonstrated in normal urine after acidification and prolonged incubation. The chromatofocusing profile obtained for NAG in the large, dense lysosomes was almost identical to the pattern observed in nephritic urine and demonstrated IPs for NAG in a slightly more basic pH area than observed for small and medium-sized lysosomes. The difference in IP in normal and nephritic urines may therefore be due to an increased autolytic degradation of NAG or excretion of the enzyme from different populations of lysosomes.
Renal Autoregulatory Efficiency during Angiotensin-Converting Enzyme Inhibition in Dogs on a Low Sodium Diet
Authors: Rosivall László , Youngblood Phil , Navar Gabriel
Published: November 2008

Autoregulatory efficiency of renal blood flow (RBF) and glomerular filtration rate (GFR) was evaluated in 12 anesthetized dogs that had been maintained on low-sodium diet during control conditions and following infusion of an angiotensin-converting enzyme inhibitor (captopril). Converting enzyme inhibition (CEI) decreased systemic blood pressure by 15.5 ± 3.5%, increased RBF by 36.3 ± 6.5%, and increased GFR by 25.9 ± 10.7%. In response to reductions in renal arterial pressure, RBF was efficiently autoregulated and did not change significantly until the 89- to 75-mm Hg range during the control period and the 74- to 54-mm Hg range during CEI. Overall GFR autoregulatory efficiency was generally well maintained during CEI; however, evaluation of the coupled autoregulatory efficiency of RBF and GFR indicated that during angiotensin blockade, there was a greater incidence of a dissociation between RBF and GFR autoregulatory efficiency. Six of the 12 dogs showed reduced GFR autoregulatory efficiency at renal arterial pressures where RBF was still well maintained. Thus, while the data indicate that blockade of the renin-angiotensin system does not abolish the basic capability of the kidney to autoregulate either RBF or GFR efficiently, more subtle influences on the coupling of RBF and GFR autoregulatory efficiency were observed at the lower level of the autoregulatory range.
Evidence that Alpha-1-Adrenergic Stimuli Specifically Increase Gluconeogenesis of the Isolated Proximal Convoluted Tubule in the Rat
Authors: Nakada Jojiro , Yamada Hideo , Endou Hitoshi
Published: November 2008

Isolated kidney-cortical tubule suspensions and microdissected nephron segments from fed rats were used to study the action of catecholamines on gluconeogenesis. Gluconeogenesis from rat tubule suspension incubated with 5 mM pyruvate was stimulated maximally by 10-5M methoxamine, an αi-selective agonist, and 10-6M noradrenaline by 29.2 ± 5.2% (mean ± SEM) and 32.6 ± 2.9%, respectively. These effects were completely inhibited by 10-7 M prazosin, a β1-selective antagonist. Yohimbine, an α 2-antagonist, also inhibited the effect, but only at a higher concentration (5 × 10-5M). Gluconeogenesis was not stimulated by isoproterenol, a α-agonist, at any concentrations between 10 -5 and 10 -7M. With microdissected nephron segments, only the proximal tubule possessed gluconeogenic activity. Within the proximal tubule, the proximal convoluted tubule (PCT) revealed higher gluconeogenic activity than the proximal straight tubule (PST). Methoxamine at 10-5M stimulated gluconeogenesis in PCT, whereas in PST no increase of gluconeogenesis was observed. From these results, it can be concluded that an α1-adrenergic agonist specifically stimulates renal gluconeogenesis in PCT, but not in PST.
Nonanticoagulant Protective Effect of Heparin in Chronic Aminonucleoside Nephrosis
Authors: Diamond Jonathan R. , Karnovsky Morris J.
Published: November 2008

Aminonucleoside nephrosis progresses over an 18-week period to focal and segmental glomerulosclerosis (FSGS). Whole heparin has been shown to blunt the extent of renal injury in another model of FSGS, renal ablation; however, the precise mechanism of protection has remained uncertain. Since heparin has a variety of physiologie actions unrelated to anticoagulation, we administered three different heparin compounds, each with a distinct profile of biological properties, to groups of rats given a single intravenous dose of puromycin aminonucleoside (PA). In the absence of a prolongation of the activated partial thromboplastin time (aPTT), both whole heparin (WH) and a 7,000- to 11,000-dalton-molecular-weight nonanticoagulant heparin (NAH) ameliorated the functional and histologic abnormalities of chronic aminonucleoside nephrosis as evidenced by significant reductions in 24-hour urine protein excretion while preserving the glomerular filtration rate and blunting the rise in serum creatinine as compared to untreated PA control animals at the conclusion of the study. In addition, the NAH and WH groups exhibited significantly fewer glomeruli with either segmental mesangial proliferative areas or glomerulosclerosis/hyalinosis lesions 18 weeks after PA administration. A fragment of heparin (HF) was ineffective. We conclude that heparin may exert its beneficial effect in chronic aminonucleoside nephrosis through a biologic action, other than anticoagulation, perhaps by inhibition of mesangial cell proliferation.
The Lysosomal Distribution of Cathepsin B in the Rat Kidney Cortex
Authors: Andersen Knut-Jan , Dobrota Miloslav
Published: November 2008

Subcellular distribution of cathepsin B following subfractionation of the kidney cortex mitochondrial/lysosomal fraction by rate sedimentation indicates that this enzyme is mainly associated with the large, fast sedimenting lysosomes (protein droplets). A small proportion of cathepsin B is also present in the small lysosomes which cosediment with mitochondria, peroxisomes, and brush border and other large membrane vesicles. Amongst this broad spectrum of small lysosomes the distribution of cathepsin B, together with other acid hydrolases is associated with the more rapidly sedimenting lysosomes whilst cathepsin D differs in being associated with the slowest sedimenting lysosomes. Equilibrium banding in sucrose gradients shows the large lysosomes band at a density of 1.235 g/ml and that the small lysosomes have two distinct populations at densities 1.20 and 1.235 g/ml. Cathepsin B (and also cathepsin D and acid ribonuclease) appears to be associated only with lysosomes of high density. The various other acid hydrolases assayed are found in all the lysosomal populations. Small and large lysosomes of high density are very rich in a number of proteinases and therefore most probably represent lysosomal populations involved in the catabolism of proteins taken up from the glomerular filtrate.
Effect of Phenylisopropyladenosine on Vasopressin-Dependent Cyclic AMP Generation in Defined Nephron Segments from Rat
Authors: Torikai Shozo
Published: November 2008

To test the possibility that adenosine may be involved in a urine concentrating mechanism, effects of 1-phenylisopropyladenosine (PIA) on cyclic AMP levels have been examined in medullary thick ascending limb (mTAL) and medullary collecting duct (MCD) isolated from the rat. Low and high doses of PIA did not alter basal cyclic AMP levels in both segments. However, PIA depressed vasopressin-dependent cyclic AMP production in MCD in a dose-dependent manner: this effect of PIA was maximum at 10-6M. 8-Phenyltheophylline, a competitive inhibitor for adenosine receptor, completely abolished this inhibitory effect of PIA. This finding may suggest an existence of adenosine receptor on the MCD. In mTAL, PIA also suppressed vasopressin-mediated cyclic AMP generation. The present study shows an interaction between PIA and vasopressin in both MCD and mTAL. This interaction may contribute in part to urinary-concentrating disturbance in renal ischemia.
Loop Diuretics
Authors: Greger R. , Wangemann P.
Published: November 2008

Loop diuretics such as furosemide, piretanide, and bumetanide bind reversibly to the Na+2Cl-K+ carrier. This transporter is responsible for the uptake of Cl- into the thick ascending limb segment. As a consequence, these compounds reduce or abolish NaCl reab-sorption in this nephron segment and lead to a decreased interstitial hypertonicity and thus to a reduced water absorption. Apart from these profound effects, loop diuretics also inhibit Ca2+ and Mg2+ reabsorption in the thick ascending limb in a manner which is still not clear. They also increase urinary K+ excretion by an increase in distal tubule NaCl and water delivery and probably also by the reduction of K+ reabsorption which goes on under in vivo conditions in the thick ascending limb segment. Finally, by the reduction of the transport work in the thick ascending limb, these compounds reduce dramatically the substrate and oxygen dependence of this nephron segment.
Thiazide Diuretics
Authors: Velázquez Heino
Published: November 2008

Thiazide diuretics increase salt and water excretion primarily by inhibiting mechanisms for electroneutral sodium and chloride transport by distal convoluted tubule cells. This might be termed the ‘specific’ effect of this class of diuretics and accounts for the ‘chlorouretic’ effectiveness of the drug. Secondary to this inhibition of sodium and chloride absorption, potassium secretion is stimulated most likely because of the resultant increase in distal tubule fluid flow rate, and calcium absorption is stimulated possibly via a decrease in distal convoluted tubule cell sodium activity and an increase in basolateral sodium/calcium exchange. To a varying degree, thiazides also inhibit carbonic anhydrase. This effect can contribute to the diuresis, but is largely buffered by the reserve transport capacity of the loop of Henle. To the extent that the effects of transport inhibition in the proximal tubule are transmitted to the distal tubule, tubuloglomerular feedback may be activated and effect a reduction in the glomerular filtration rate.
Epithelial Cells in Tissue Culture
Authors: Gstraunthaler Gerhard J.A.
Published: November 2008

In this review the characteristics of established renal and intestinal epithelial cell lines are described by summarizing the accumulated literature about specific properties retained by the cells in tissue culture. Furthermore, brief examples are given for the use of cultured epithelia as model systems to study epithelial transport and metabolic functions, epithelial cell polarity, and aspects of the differentiation and maturation of epithelia by physiological, biochemical and genetic, or cell and molecular biological approaches.
Glomerular Hyperfiltration in Hypertensive Fawn-Hooded Rats
Authors: de Keijzer M.H. , Provoost A.P. , Molenaar J.C.
Published: November 2008

The glomerular filtration rate (GFR), effective renal plasma flow (ERPF), systolic blood pressure (SBP) and urinary protein excretion (UPV) were determined in 12-week-old male rats of the spontaneously hypertensive Fawn-Hooded (FH) strain. These data were compared with those of either age-matched or weight-matched male, normotensive Wistar Albino Glaxo (WAG) rats. The GFR was significantly higher in FH rats than in both WAG control groups. In contrast, the ERPF did not differ between the FH and WAG rats. Thus, a higher filtration fraction was present in the FH rats. As no differences were found in the total number of glomeruli per kidney comparing FH and WAG rats, the high GFR was not due to an increase in the number of glomeruli. The SBP and the UPV were significantly higher in FH rats than in WAG rats. To our opinion, the arterial hypertension associated with glomerular hyperfiltration proteinuria suggests the presence of glomerular hypertension in FH rats.
Comparative Aspects of Cell Osmoregulation and Volume Control
Authors: Gilles R.
Published: November 2008

This brief overview considers the mechanisms of adaptation of animal cells to anisosmotic media in the framework of a comparative approach. Successful adaptation of animal cells to abrupt changes in the NaCl content of their environment depends on (1) mechanisms of osmolality and volume control and (2) the use of different organic molecules acting as ‘compensatory osmolytes’. Up to now, the importance of this last process has been largely underestimated. It concerns the use of different organic osmolytes, aminocompounds and carbohydrates which can oppose or ‘compensate for’ the disrupting effects that changes in the intracellular level of inorganic ions can have on the organization and activity of different macromolecular structures. Contrarily to the cells of euryhaline invertebrates, most mammalian cells seem to lack the possibility to regulate effectively their content of organic compensatory solutes. Despite the presence of effective mechanisms of cell volume and osmolality control, they thus adapt only with difficulty to abrupt changes in the NaCl level of their environment. An interesting exception is the kidney medulla in which papillary cells seem to control easily the level of some selected amino compounds and carbohydrates. The use of these compensatory osmolytes enables them to cope with the rapid and sometimes important modifications in the NaCl level they are normally withstanding.
When Sound Meets Movement: Performance in Electronic Dance Music
Authors: Ferreira Pedro Peixoto
Published: November 2008

This article discusses the problem of performance in electronic dance music (EDM), considering its specificity in the use of technically reproduced sound to promote a non-stop dancing experience. Instead of a schizophonic rupture between performer and audience, EDM is seen to perform a transducive mediation between machine sound and human movement.
The cytoplasm of mouse germinal vesicle stage oocytes can enhance somatic cell nuclear reprogramming
Authors: Bui Hong-Thuy , Wakayama Sayaka , Kishigami Satoshi , Kim Jin-Hoi , Van Thuan Nguyen , Wakayama Teruhiko
Published: November 2008

In mammalian cloning, evidence suggests that genomic reprogramming factors are located in the nucleus rather than the cytoplasm of oocytes or zygotes. However, little is known about the mechanisms of reprogramming, and new methods using nuclear factors have not succeeded in producing cloned mice from differentiated somatic cell nuclei. We aimed to determine whether there are functional reprogramming factors present in the cytoplasm of germinal vesicle stage (GV) oocytes. We found that the GV oocyte cytoplasm could remodel somatic cell nuclei, completely demethylate histone H3 at lysine 9 and partially deacetylate histone H3 at lysines 9 and 14. Moreover, cytoplasmic lysates of GV oocytes promoted somatic cell reprogramming and cloned embryo development, when assessed by measuring histone H3-K9 hypomethylation, Oct4 and Cdx2 expression in blastocysts, and the production of cloned offspring. Thus, genomic reprogramming factors are present in the cytoplasm of the GV oocyte and could facilitate cloning technology. This finding is also useful for research on the mechanisms involved in histone deacetylation and demethylation, even though histone methylation is thought to be epigenetically stable.
Mechanisms and variation in plant development: sorting the wood from the trees in Vermont
Authors: Coupland George
Published: November 2008

The biannual FASEB summer research conference `Mechanisms in Plant Development' was recently held in Saxtons River, Vermont and was organised by Neelima Sinha and Cris Kuhlemeier. Although most of the work discussed at the meeting concentrated on developmental mechanisms and on studies in Arabidopsis and maize, the meeting also emphasised the importance of variation between species and the elaboration of a broader range of model systems.
Lipid Analysis by near Infrared Spectroscopy to Evaluate Inhibitory Effects of Swine Waste Compost on Plant Growth
Authors: Fujiwara Takayuki , Murakami Keiichi
Published: November 2008

The lipid content of swine manure decreases during the process of composting, and inhibitory effects of compost on root growth in germination tests are strongly correlated to lipid content. Therefore, we tested whether the determination of the lipid content of swine waste compost by near infrared (NIR) spectroscopy provided a measure by which the degree of inhibition of plant growth by immature compost could be predicted. Reflectance spectra of untreated compost samples, as well as freeze-dried and milled samples, were taken using a scanning monochromator. Second derivative spectra from 700 nm to 2500 nm and multiple regression analysis were used to develop calibration equations for lipid content and moisture. A pronounced absorption peak of lipid was found at 2310 nm, attributable to the absorption bands of the CH2 stretching–bending combination. However, calibration equations containing this absorption band were inappropriate for lipid determination, because sawdust and rice husk, which were added to the compost, influenced the spectra in this band. The standard error of prediction ( SEP) of the best calibrations for lipids in dry and untreated samples was 6.0 g kg−1 and 3.2 g kg−1, while the ratios of the standard deviation and the range in the prediction set to SEP (RPD and RER) were 5.5 and 2.8, and 13.5 and 5.0, respectively. The main wavelengths of these calibration equations were 1700 nm for dry samples and 1764 nm for untreated samples, which were attributed to the absorption bands of the CH2 stretching first overtone. In conclusion, the determination of lipid content in dry compost samples by NIR spectroscopy provided an indirect estimate of the maturity of swine waste compost. Moreover, NIR spectroscopy was found useful for the rough assessment of the maturity of untreated swine waste compost.
A Recursive Perspective on Discursive Legitimation and Organizational Action in Mergers and Acquisitions
Authors: Vaara Eero , Monin Philippe
Published: November 2008

This paper challenges the predominant view that legitimation is merely a specific phase in merger or acquisition processes. We argue that a better understanding of postmerger organizational dynamics calls for conceptualization of discursive legitimation as an inherent part of unfolding merger processes. In particular, we focus on the recursive relationship between legitimation and organizational action. We have two objectives: to outline a theoretical model that helps one to understand the dynamics of discursive legitimation and organizational action in postmerger organizations, and to examine a revealing case to distinguish the inherent risks and problems in discursive legitimation. Our case analysis focuses on the merger between the French pharmaceutical companies BioMérieux and Pierre Fabre. We adopt a critical multimethod approach and distinguish specific discursive dynamics and pathological tendencies in this case. The analysis highlights the unintended consequences of discursive legitimation, the central role of sensegiving and sensehiding in discursive legitimation, the inherently political nature of legitimation and the risks associated with politicization, the special problems associated with fashionable discourses and the role of the media, the use of specific discursive strategies for legitimation and delegitimation, and the crucial role of actual integration results. This analysis adds to the existing research on mergers and acquisitions by treating discursive legitimation as part of the merger dynamics. In particular, our case analysis provides a new explanation for merger failure. We also believe that the recursive model connecting discursive legitimation and delegitimation strategies to concrete organizational action makes a more general contribution to our understanding of organizational legitimation.
Bernhard Paumgartner und Felix Petyrek: Zwei Mitarbeiter der Musikhistorischen Zentrale beim k. u. k. Kriegsministerium (1916–1918)
Authors: Hois Eva
Published: November 2008

A special chapter of research into the history of folk music in the time of the Austrian-Hungarian Monarchy was the Musikhistorische Zentrale (Music History Department) at the imperial royal Ministry of War. It was established during World War I, modelled on the Austrian Volksliedunternehmen (today Volksliedwerk). The Musikhistorische Zentrale wanted to collect all the soldiers’ songs, fanfares, military music, soldiers’ sayings, customs, jokes, letters and their expressions which are of historical and cultural significance. Bernhard Paumgartner (1887–1971), a musician and lawyer, had the idea of collecting this material. After the war, he became well known as the director of the Mozarteum in Salzburg, as conductor, music researcher and member of the Salzburger Festspiele. Under Paumgartner’s direction, notable individuals were involved in the compilation of Musikhistorische Zentrale. One of these men was the student of composition and musicology Felix Petyrek (1892–1951), who was dedicated to folk music all over his life as composer as well as researcher and music teacher. Other important collaborators for the Hungarian part on the collection were Zoltán Kodály and Béla Bartók.
Bonding Durability of Single-Step Adhesives to Previously Acid-Etched Dentin
Authors: Ikeda M. , Tsubota K. , Takamizawa T. , Yoshida T. , Miyazaki M. , Platt J. A.
Published: November 2008

Clinical Relevance

To achieve optimum bond strengths, acid etching of dentin prior to the application of single-step self-etch adhesive systems should be avoided.
Schistosomiasis: An Unexpected Finding in an Inguinal Hernia Sac
Authors: Pawel Bruce R. , Osman Jailan , Nance Michael L. , McGowan Karin L.
Published: November 2008

We report an 11-year-old boy who was diagnosed with schistosomiasis based on histopathologic examination of an inguinal hernia sac specimen. The child was an immigrant from Liberia and presented to our institution with inguinal and scrotal swelling. His past medical history was remarkable for previous ipsilateral hernia sac repair in West Africa, and at the time of his recurrent hernia repair, he was noted to have a peculiar loculated fluid-filled hernia sac, which was sent for pathologic examination because of its unusual appearance. Histologic examination revealed an intense infiltrate of eosinophils and numerous granulomas with ova of Schistosoma mansoni, and this speciation was confirmed with a stool wet prep examination for ova and parasites. Review of the English-language literature uncovered no prior cases of schistosomiasis presenting as an inguinal hernia. This unusual finding in a “routine” specimen, otherwise destined for the incinerator without pathologic evaluation, reinforces the importance of surgical vigilance in recognizing unusual or atypical features in these specimens.
Idiopathic Infantile Arterial Calcification: The Spectrum of Clinical Presentations
Authors: Chong Curtis R. , Hutchins Grover M.
Published: November 2008

Idiopathic infantile arterial calcification (IIAC) is a rare disorder characterized by extensive calcification of medium and large arteries. We report the case of a 32-week-old infant with hydrops fetalis and heart failure who died at 4 days of age. At autopsy the infant was found to have cardiomegaly, myocardial infarctions and multifocal calcifications of the aorta and arteries in the lungs, heart, thyroid, spleen, and testis. Calcification extended from the internal elastic lamina into the intima and media and was associated with a giant-cell reaction and smooth muscle proliferation. A search of the English language medical literature identified 161 IIAC case reports. Of these, 48% of cases presented in utero or at birth with hydrops fetalis, maternal hydramnios, heart failure, or respiratory distress and 52% present later, at a median age of 3 months, with sudden onset of fever, vomiting, irritability, or respiratory distress in a previously healthy infant. Significantly, 19 of 22 IIAC survivors presented at less than 2 weeks of age, and 15 survivors were treated with diphosphonates.
Telomerase Activity of Chorionic Trophoblasts in Preterm Premature Rupture of Membranes
Authors: Ozer Erdener
Published: November 2008

Premature rupture of membranes (PROM) is a complication associated with preterm birth. Because most neonatal death, morbidity, and cost are linked to preterm birth, understanding the mechanisms for developing preterm PROM (pPROM) is critical. The aim of this study is to investigate whether telomerase activity of the chorionic trophoblasts may play a role in the pathogenesis of PROM. Placental membranes were collected from 56 patients with pPROM and 45 patients with preterm labor (PTL). Telomerase activity was assessed by immunohistochemistry, and telomerase activity index (TAI) was calculated for both groups. Results are expressed as the mean + standard deviation. Differences between groups were analyzed using an independent-samples t-test. To evaluate other suggested mechanisms, such as apoptosis and extracellular matrix degradation, immunohistochemistry for matrix metalloproteinase (MMP)-9, tissue inhibitor of metalloproteinase (TIMP)-3, and M30 CytoDEATH antibodies were also performed. The TAI was found to be 6.8 + 3.2 for PTL, while it was 2.5 + 1.5 for pPROM. Decreased TAI was statistically significant in pPROM membranes in comparison with PTL ( P < 0.001). Number of apoptotic trophoblasts was significantly increased for the membranes of pPROM ( P < 0.001), whereas strong staining of MMP-9 and TIMP-3 was found for chorionic trophoblasts as well as for other cells in both groups. Although study of the pPROM has focused on activation of matrix metalloproteinases and apoptosis that result in the consequence of a programmed membrane weakening process, decreased telomerase activity of chorionic trophoblasts is likely to have a contributing role in the pathogenesis of pPROM as well.
Catatonia: The Ultimate Response to Fear??
Authors: Perkins Richard J.
Published: November 2008

A brief review of the literature on catatonia is followed by a description of four cases of acute catatonia occurring in a medical ward setting. A biopsychosocial model is suggested for understanding the aetiology of catatonia.
The Music of Psychiatry
Authors: Ellard John
Published: November 2008

The author argues that the practice of psychiatry is impeded by a central paradox. On the one hand, psychiatry cannot develop unless the methods of science are used to unravel its problems. On the other, a significant part of what has been advanced as science is of little value and has done no more than divert attention from the important non-scientific aspects of psychiatric practice. Empathetic and perceptive practice is central for good psychiatry; there is no reason to believe that scientific method alone—good or bad—will lead to its achievement.
Current Perspectives on Immunology and Psychiatry
Authors: O'donnell Maryanne , Silove Derrick , Wakefield Denis
Published: November 2008

We selectively review recent research findings in the field of psychoimmunology which test the hypotheses that immunological dysfunction may be aetiologically related to mental illnesses such as schizophrenia, and that certain morbid affective states such as depression and other forms of psychosocial distress may be the cause of immunosuppression and through this mechanism affect the outcome of illnesses such as cancer. Our examination of research implicating immunological or infective mechanisms in the aetiology of schizophrenia indicates that most studies have been unable to control for major methodological difficulties but the compatibility of these theories with the dopamine hypothesis suggests that further research attention is warranted. More clearly, there is growing evidence demonstrating a link between depression, other states of psychological distress and immunosuppression, but the clinical significance of these findings remains uncertain. The complex relationship between stress and the outcome of illnesses such as cancer is discussed and the possible implications of these findings for clinical psychiatry are suggested.
Psychiatry in Vietnam
Authors: Minas Harry
Published: November 2008

In November 1996 a collaborative workshop organised by the Vietnam National Institute of Mental Health and the Section of Social and Cultural Psychiatry of the Royal Australian and New Zealand College of Psychiatrists was held in Hanoi. Approximately 45 participants from Australia and New Zealand and 90 psychiatrists and psychiatric trainees from throughout Vietnam attended the workshop. This was the first major psychiatric scientific meeting held in Vietnam and was a valuable opportunity for colleagues from the three countries to meet and get to know each other, and to discuss recent developments in mental health and opportunities for collaboration. The meeting was very successful. It was certainly a most enjoyable experience. A number of collaborative possibilities that were discussed are now being actively pursued.
Mothering Children with Disabilities and Chronic Conditions: Long-Term Implications for Self-Reported Health
Authors: Burton Peter , Lethbridge Lynn , Phipps Shelley
Published: November 2008

Dans cet article, à partir des données de l’Enquête longitudinale nationale sur les enfants et les jeunes, nous tentons de répondre à trois questions. a) Élever un enfant ayant un handicap ou une maladie chronique a-t-il un effet négatif sur la santé maternelle ? b) Si oui, cet effet croît-il à long terme ? c) Cet effet est-il plus marqué chez les mères célibataires que chez celles qui sont mariées ? Nos observations nous permettent de tirer les conclusions suivantes. Les mères – mariées ou célibataires – qui élèvent un enfant ayant un handicap ou une maladie chronique affirment être en moins bonne santé. Ce phénomène s’amplifie avec le temps. Quand on tient compte des variables que sont les déterminants de la santé, on n’observe pas de différence significative entre l’état de santé des mères célibataires et celui des mères mariées, et le lien entre l’état de santé et le fait d’avoir un enfant handicapé n’est pas plus important chez les mères célibataires que chez celles qui sont mariées.
Residual nonfunctioning pituitary adenomas: prognostic value of MIB-1 labeling index for tumor progression
Authors: Widhalm Georg , Wolfsberger Stefan , Preusser Matthias , Fischer Ingeborg , Woehrer Adelheid , Wunderer Joerg , Hainfellner Johannes A. , Knosp Engelbert
Published: November 2008

Object

In residual nonfunctioning pituitary adenomas, reliable prognostic parameters indicating probability of tumor progression are needed. The Ki 67 expression/MIB-1 labeling index (LI) is considered to be a promising candidate factor. The aim in the present study was to analyze the clinical usefulness of MIB-1 LI for prognosis of tumor progression.

Methods

The authors studied a cohort of 92 patients with nonfunctioning pituitary adenomas. Based on sequential postoperative MR images, patients were classified as tumor free (51 patients) or as harboring residual tumor (41 individuals). The residual tumor group was further subdivided in groups with stable residual tumors (14 patients) or progressive residual tumors (27 patients). The MIB-1 LI was assessed in tumor specimens obtained in all patients, and statistical comparisons of MIB-1 LI of the various subgroups were performed.

Results

. The authors found no significant difference of MIB-1 LI in the residual tumor group compared with the tumor-free group. However, MIB-1 LI was significantly higher in the progressive residual tumor group, compared with the stable residual tumor group. Additionally, the time period to second surgery was significantly shorter in residual adenomas showing an MIB-1 LI > 3%.

Conclusions

The data indicate that MIB-1 LI in nonfunctioning pituitary adenomas is a clinically useful prognostic parameter indicating probability of progression of postoperative tumor remnants. The MIB-1 LI may be helpful in decisions of postoperative disease management (for example, frequency of radiographic intervals, planning for reoperation, radiotherapy, and/or radiosurgery).
Paradoxical dysregulation of the neural stem cell pathway sonic hedgehog‐gli1 in autoimmune encephalomyelitis and multiple sclerosis
Authors: Wang Yue , Imitola Jaime , Rasmussen Stine , O'Connor Kevin C. , Khoury Samia J.
Published: November 2008

Objective

Neurovascular niches have been proposed as critical components of the neural stem cell (NSC) response to acute central nervous system injury; however, it is unclear whether these potential reparative niches remain functional during chronic injury. Here, we asked how central nervous system inflammatory injury regulates the intrinsic properties of NSCs and their niches.

Methods

We investigated the sonic hedgehog (Shh)‐Gli1 pathway, an important signaling pathway for NSCs, in experimental autoimmune encephalomyelitis (EAE) and multiple sclerosis (MS), and its regulation by inflammatory cytokines.

Results

We show that Shh is markedly upregulated by reactive and perivascular astroglia in areas of injury in MS lesions and during EAE. Astroglia outside the subventricular zone niche can support NSC differentiation toward neurons and oligodendrocytes, and Shh is a critical mediator of this effect. Shh induces differential upregulation of the transcription factor Gli1, which mediates Shh‐induced NSC differentiation. However, despite the increase in Shh and the fact that Gli1 was initially increased during early inflammation of EAE and active lesions of MS, Gli1 was significantly decreased in spinal cord oligodendrocyte precursor cells after onset of EAE, and in chronic active and inactive lesions from MS brain. The Th1 cytokine interferon‐γ was unique in inducing Shh expression in astroglia and NSCs, while paradoxically suppressing Gli1 expression in NSCs and inhibiting Shh‐mediated NSC differentiation.

Interpretation

Our data suggest that endogenous repair potential during chronic injury appears to be limited by inflammation‐induced alterations in intrinsic NSC molecular pathways such as Gli1. Ann Neurol 2008;64:417–427
A novel thermolysis method of colloidal protein precursors to prepare hydroxyapatite nanocrystals
Authors: Han Yingchao , Li Shipu , Wang Xinyu
Published: November 2008

A novel thermolysis method of colloidal protein precursors is introduced to prepare hydroxyapatite (HAP) nanocrystals. The colloidal protein precursors are sonochemically synthesized from saturated Ca(OH)2 aqueous solution, Ca(H2PO4)2 aqueous solution and bovine serum albumin (BSA) molecules. The colloidal protein precursors are amorphous and composed of 15‐90 nm near spherical calcium phosphate nanoparticles and BSA molecules. The particle size analysis shows the volume particle size distribution is from 9.0 nm to 222.6 nm and the volume‐averaged particle size is 45.8 nm. During the calcination procedure BSA molecules are burningly removed and the HAP nanocrystals can be obtained at 500 °C. The effects of BSA concentration on the properties of samples are discussed. Results show that BSA combustion can promote the transformation of crystalline HAP from amorphous material. Moreover, the increase of BSA concentration reduces the crystalline sizes of HAP crystals and the crystallinity of product. With BSA concentration of 5 g/L, the obtained HAP nanocrystals are mainly 25∼100 nm similar spherical nanoparticles besides some 40∼70 nm×75∼150 nm short rod‐like crystals. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On slow protein crystal nucleation: cluster‐cluster aggregation on diffusional encounters
Authors: Nanev C. N.
Published: November 2008

With a view to experimental results on protein crystal nucleation the effects of cluster coalescence are probed semi‐quantitatively. The steric association restriction, which stems from the patchy surface of the protein molecules, explains both experimentally measured low crystal nucleation rate and coalescence limitations for crystalline clusters of protein molecules. The conclusion is that due to its action, and the impact of rotational diffusion, the coalescence of critical (and/or supercritical) clusters should be rejected as a conceivable alternative for explaining the slow nucleation of protein crystals. Besides, the analysis of cluster‐cluster aggregation on diffusional encounters may be of more general interest; it may be helpful by considering the coalescence of structured bio‐nano‐particles. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A study of deploying smooth‐ and responsive‐TCPs with different queue management schemes
Authors: Zhang Chi , Mamatas Lefteris , Tsaoussidis Vassilis
Published: November 2008

While there exist extensive research works on congestion control and active queue management, or the joint dynamics of a congestion control strategy with the random early detection (RED) algorithm, little has been done on the interactions between different window adjustment strategies and different queue management schemes such as DropTail and RED. In this paper, we consider a spectrum of TCP‐friendly additive increase and multiplicative decrease (AIMD) parameters. At the one end of this spectrum, smooth‐TCP enhances smoothness for multimedia applications by reducing the window decrease ratio upon congestion, at the cost of the additive increase speed and the responsiveness to available bandwidth. At the other end, responsive‐TCP enhances the responsiveness by increasing the additive increase speed, at the cost of smoothness. We investigate the network dynamics with various combinations of AIMD parameters and queue management schemes, under different metrics. The investigation is conducted from the deployment (especially incremental deployment) point of view. We discussed the impact of the interactions on the goodput, fairness, end‐to‐end delay, and its implications to energy consumption on mobile hosts. Copyright © 2008 John Wiley & Sons, Ltd.
The role of the PI3K‐AKT kinase pathway in T‐cell development beyond the β checkpoint
Authors: Xue Ling , Chiang Leslie , Kang Chulho , Winoto Astar
Published: November 2008

The PI3K‐AKT pathway can mediate diverse biological responses and is crucial for optimal immune responses and lymphocyte development. Deletion of PI3K subunits or AKT leads to blockage of T‐cell development at the TCR‐β checkpoint. Studies with over‐expression of constitutively activated AKT have implicated this pathway in anti‐apoptosis of developing thymocytes and in development of regulatory T cells. However, the role of endogenous PI3K‐AKT in T‐cell development beyond the TCR‐β checkpoint remains unclear. Here, we inhibited the endogenous PI3K‐AKT pathway in thymocytes after double negative stages by expressing the negative regulator, PTEN. These mice exhibit normal early T‐cell development, but the transition from intermediate single positive to double positive (DP) thymocytes is inhibited, leading to a significantly decreased number of DP, single positive thymocytes and peripheral T cells. Proliferation of peripheral T cells is reduced but apoptosis of DP cells and subsequent T‐cell maturation, including regulatory T cells, are normal. AKT phosphorylation can be readily observed in most WT T‐cell compartments but not DP thymocytes in response to TCR activation. Thus, the PI3K‐AKT pathway is crucial for the transition of intermediate single positive to DP thymocytes but is dispensable for apoptosis and maturation of developing thymocytes.
Ischemia‐reperfusion injury is attenuated in VAP‐1‐deficient mice and by VAP‐1 inhibitors
Authors: Kiss Jan , Jalkanen Sirpa , Fülöp Ferenc , Savunen Timo , Salmi Marko
Published: November 2008

Neutrophils mediate the damage caused by ischemia‐reperfusion both at the site of primary injury and in remote organs. Vascular adhesion protein‐1 (VAP‐1) is an ectoenzyme expressed on endothelial cells and it has been shown to regulate leukocyte extravasation. Here we show for the first time using VAP‐1‐deficient mice that VAP‐1 plays a significant role in the intestinal damage and acute lung injury after ischemia‐reperfusion. Separate inhibition of VAP‐1 by small molecule enzyme inhibitors and a function‐blocking monoclonal antibody in WT mice revealed that the catalytic activity of VAP‐1 is responsible for its pro‐inflammatory action. The use of transgenic humanized VAP‐1 mice also showed that the enzyme inhibitors alleviate both the ischemia‐reperfusion injury in the gut and neutrophil accumulation in the lungs. These data thus indicate that VAP‐1 regulates the inflammatory response in ischemia‐reperfusion injury and suggest that blockade of VAP‐1 may have therapeutic value.
A two‐step model for Langerhans cell migration to skin‐draining LN
Authors: Villablanca Eduardo J. , Mora Jorge R.
Published: November 2008

Although the role of Langerhans cells (LC) in skin immune responses is still a matter of debate, it is known that LC require the chemokine receptor CCR7 for migrating to skin‐draining LN. A report in the current issue of the European Journal of Immunology unfolds some of the intricacies of LC migration, showing that LC need CXCR4, but not CCR7, for their migration from the epidermis to the dermis. Thus, LC migration to skin‐draining LN occurs in two distinct phases: a first step from the epidermis to the dermis regulated by CXCR4 and a second CCR7‐dependent step from the dermis to LN. Here we discuss the potential implications of this new two‐step LC migration paradigm.