bluuebunny/crossref_metadata_2025 huggingface dataset:
Dissection of the dual function of the β‐subunit of protein kinase CK2 (‘casein kinase‐2’): a synthetic peptide reproducing the carboxyl‐terminal domain mimicks the positive but not the negative effects of the whole protein
Authors: Marin Oriano , Meggio Flavio , Boldyreff Brigitte , Issinger Olaf-G. , Pinna Lorenzo A.
Published: July 2002

The dual function of the regulatory β‐subunit of protein kinase CK2 is highlighted by its ability to abolish calmodulin phosphorylation in contrast to its stimulatory effect on the phosphorylation of peptide substrates. Here we show that a synthetic peptide reproducing the C‐terminal region of the β‐subunit (β[170–215]) stimulates to a similar extent the phosphorylation of either the peptide substrate or calmodulin and also protects the catalytic α‐subunit against thermal inactivation as efficiently as full‐length β‐subunit. These data show that the positive and negative functions of the β‐subunit reside in physically separated domains and that the elements responsible for positive regulation are located in the C‐terminal region.
Magnesium‐independent activation of inward‐rectifying K+ channels in Vicia faba guard cells
Authors: Schroeder Julian I.
Published: July 2002

The activation of inward‐rectifying K+ channels in guard cells at membrane potentials negative of the K+ equilibrium potential is important for their cellular function as proton pump‐driven K+ uptake pathways during stomatal opening. In animal cells the voltage‐dependence of inward‐rectifying K+ channels is produced to a large extent by intracellular magnesium block. In guard cells, when cytosolic Mg2+ was either 3 mM or < I μM, activation times, deactivation times and the steady‐state voltage‐dependence of K+ channels remained unchanged. It is discussed that the activation mechanism of inward‐rectifying K+ channels in guard cells is independent of intracellular Mg2+ block.
Sequence homologies between nucleotide binding regions of CFTR and G‐proteins suggest structural and functional similarities
Authors: Manavalan Parthasarathy , Dearborn Dorr G. , McPherson John M. , Smith Alan E.
Published: July 2002

Sequence homology between the α‐subunits of G‐proteins and other GTP‐binding proteins and certain regions within the nucleotide binding domains (NBDs) of cystic fibrosis transmembrane conductance regulator (CFTR) indicates that these protein structures may be similar. A sequence allignment of the NBDs of CFTR and NBDs from other membrane transporters, forms the basis of a structural model. This model predicts that one of the conserved sequences GGQR, within which a number of CF mutations occur, forms part of the nucleotide binding pocket and serves as an ON/OFF conformational switch as observed in GTP binding proteins. Furthermore, based on subtle sequence differences between the first and second NBDs of CFTR and from structure‐activity data, we suggest that the nucleotide binding site environments of the two NBDs are different.
Labetalol vs. methyldopa in the treatment of pregnancy‐induced hypertension
Authors: El‐Qarmalawi A.M. , Morsy A.H. , Al‐Fadly A. , Obeid A. , Hashem M.
Published: July 2002

Objective: To assess the efficacy and safety of labetalol compared with methyldopa in the management of mild and moderate cases of pregnancy‐induced hypertension (PIH). Methods: One hundred four primigravidas with PIH were randomly allocated to receive either labetalol (group A) or methyldopa (group B). The dose of the drugs was doubled every 48 h to maintain a mean arterial blood pressure ≤103.6 mmHg. Clinico‐biochemical effects and frequency of side effects were studied. The statistical level of significance was taken at P < 0.05. Results: Ten patients in group B (18.5%) developed significant proteinuria (>30 mg/dl) whereas none developed proteinuria in group A. Labetalol was quicker and more efficient at controlling blood pressure, having a beneficial effect on renal functions and causing fewer side effects compared with methyldopa. The rate of induction of labor and rate of cesarean section for uncontrolled PIH was less in group A (48% and 1%, respectively) compared with group B (63.0% and 5.6%, respectively). Moreover a higher Bishop score at induction of labor was noticed in group A. Conclusions: Labetalol is better tolerated than methyldopa, gives more efficient control of blood pressure and may have a ripening effect on the uterine cervix.
An Index of Portfolio Diversification
Authors: Woerheide Walt , Persson Don
Published: July 2002

A recurring question in the literature concerning diversification is what is the minimum number of securities required to achieve adequate diversification. The problem is that studies on this topic assume equally distributed holdings. In reality, portfolios are not evenly divided. The purpose of this paper is to evaluate the ability offive different measures of diversification to provide meaningful information about the degree of diversi’cation of an unevenly distributed stock portfolio. The complement of the Herjindahl index was found to be the best of the jive measures and its explanatory power was deemed to be adequate for general use.
The crystal structure of saporin SO6 from Saponaria officinalis and its interaction with the ribosome
Authors: Savino Carmelinda , Federici Luca , Ippoliti Rodolfo , Lendaro Eugenio , Tsernoglou Demetrius
Published: July 2002

The 2.0 Å resolution crystal structure of the ribosome inactivating protein saporin (isoform 6) from seeds of Saponaria officinalis is presented. The fold typical of other plant toxins is conserved, despite some differences in the loop regions. The loop between strands β7 and β8 in the C‐terminal region which spans over the active site cleft appears shorter in saporin, suggesting an easier access to the substrate. Furthermore we investigated the molecular interaction between saporin and the yeast ribosome by differential chemical modifications. A contact surface inside the C‐terminal region of saporin has been identified. Structural comparison between saporin and other ribosome inactivating proteins reveals that this region is conserved and represents a peculiar motif involved in ribosome recognition.
Transport mechanism and metabolism of olive oil hydroxytyrosol in Caco‐2 cells
Authors: Manna Caterina , Galletti Patrizia , Maisto Giovanna , Cucciolla Valeria , D'Angelo Stefania , Zappia Vincenzo
Published: July 2002

3,4‐Dihydroxyphenylethanol (hydroxytyrosol; DPE) is the major phenolic antioxidant present in extra virgin olive oil, either in a free or esterified form. Despite its relevant biological effects, no data are available on its bioavailability and metabolism. The aim of the present study is to examine the molecular mechanism of DPE intestinal transport, using differentiated Caco‐2 cell monolayers as the model system. The kinetic data demonstrate that [14C]DPE transport occurs via a passive diffusion mechanism and is bidirectional; the calculated apparent permeability coefficient indicates that the molecule is quantitatively absorbed at the intestinal level. The only labelled DPE metabolite detectable in the culture medium by HPLC (10% conversion) is 3‐hydroxy‐4‐methoxyphenylethanol, the product of catechol‐O‐methyltransferase; when DPE is assayed in vitro with the purified enzyme a K
m value of 40 μM has been calculated.
Heat Flux Measurements for the Fast Monitoring of Dynamic Responses to Glucose Additions by Yeasts that were Subjected to Different Feeding Regimes in Continuous Culture
Authors: van Kleeff Bastiaan H. A. , Kuenen J. Gijs , Heijnen Joseph J.
Published: July 2002

Heat measurements have been used successfully as an analytical tool for the study of the dynamics of energy metabolism of Saccharomyces cerevisiae and Candida utilis grown in continuous culture under fluctuating substrate supply. A low average dilution rate (D = 0.05 h−1) was maintained either by adding the medium as continuously (dropwise) as possible or (blockwise) by adding the medium at high speed during a short period (D = 0.5 h−1 for 40 s) and not at all during the following period (D = 0.00 h−1 for 360 s). The resulting biological activity was monitored on‐line with conventional (O2 and CO2) off‐gas analyses, DOT measurements, and heat flux measurements. In C. utilis cultures, the biomass‐specific maximum oxygen consumption rate (qO 2,max), the biomass yield (Ys,x), and the dynamic responses to a glucose pulse and to a change in feeding regime were not significantly affected by different preceding feeding regimes. In contrast, S. cerevisiae grown in continuous culture with blockwise feed showed a 50% increase in qO 2,max and a 25% drop in Ys,x compared to the culture grown with dropwise feed. The dynamic response to a glucose pulse (0.6 g L−1) was slower for the continuous (dropwise) than for the blockwise grown S. cerevisiae. With a second testing method for the dynamic response of the yeasts, the feeding regime was changed. The blockwise fed S. cerevisiae proved to be better “trained” to cope with sudden changes in glucose supply and, therefore, was more “shockproof” toward a change in feeding regime. This clearly points to major differences in the intracellular metabolic flux control between the yeasts. These findings are of relevance for industrial baker's yeast production, where reactor mixing times of one to several minutes are not uncommon. The observed heat production, together with the dissolved oxygen concentration, appeared to give the fastest response to actual changes in the culture. It is suggested that heat measurements can be a very useful tool to monitor and control the growth of S. cerevisiae in laboratory and industrial fermenter operations.
Enhancing Enzymatic Saccharification of Waste Newsprint by Surfactant Addition
Authors: Wu Jian , Ju Lu‐Kwang
Published: July 2002

Several nonionic surfactants, Pluronic F68 and F88 (BASF) as well as Tween 20 and 80, were found in this study to enhance the enzymatic hydrolysis of pretreated newsprint. Pluronic F68 was the most effective among the surfactants studied. With 2% (w/v) F68 the cellulose (10 g/L) conversion achieved with 2 g/L cellulase reached 52%, about the same as the 48% conversion achieved with 10 g/L cellulase in a surfactant‐free system. An empirical model, x = Kt0.5‐(t/τ)1/2, has been developed to describe the extended hydrolysis, where x is conversion, t is reaction time, and K and τ correspond to the initial saccharification rate and the characteristic time for its tendency to deviate from the initial power‐law (exponent = 0.5) behavior. The best‐fit K and τ in the extended hydrolysis experiments confirmed that F68 significantly enhanced both the initial rate and long‐term hydrolysis. A study was also made to evaluate the compatibility of these surfactants, at concentrations up to 2% (w/v), with cultures of Saccharomyces cerevisiae and Dekkera clausenii. While Tween 20 was found strongly inhibitory to D. clausenii, the culture growth in all other surfactant‐added systems was comparable to that in the surfactant‐free controls.
Microbial genome sequencing
Authors: Fraser Claire M. , Eisen Jonathan A. , Salzberg Steven L.
Published: July 2002

Complete genome sequences of 30 microbial species have been determined during the past five years, and work in progress indicates that the complete sequences of more than 100 further microbial species will be available in the next two to four years. These results have revealed a tremendous amount of information on the physiology and evolution of microbial species, and should provide novel approaches to the diagnosis and treatment of infectious disease.
Theoretical and experimental studies of the unprecedented spin-dependent structures of [Cp2Fe2(CO)2], the double-CO-loss product of [Cp2Fe2(CO)4]
Authors: Vitale Marcello , Archer Marsi E. , Bursten Bruce E.
Published: July 2002

Photochemically generated [(η-C5R5)2Fe2(CO)2], which is a triplet molecule with terminal CO ligands, undergoes thermal relaxation to the singlet ground state of the molecule, which has bridging CO ligands.
Fish otolith contains a unique structural protein, otolin‐1
Authors: Murayama Emi , Takagi Yasuaki , Ohira Tsuyoshi , Davis James G. , Greene Mark I. , Nagasawa Hiromichi
Published: July 2002

A collagen‐like protein was identified from the otoliths of the chum salmon, Oncorhynchus keta. The otolith, composed mainly of calcium carbonate with small amount of organic matrices, is formed in the inner ear and serves as a part of the hearing and balance systems. Although the organic matrices may play important roles in the growth of otolith, little is known about their chemical nature and physiological function. In this study, a major organic component of the otolith, designated otolin‐1, which may serve as a template for calcification, was purified. The sequences of two tryptic peptides from otolin‐1 revealed high homology with parts of a saccular collagen which had been described previously [Davis, J.G., Oberholtzer, J.C., Burns, F.R. & Greene, M.I. (1995) Science267, 1031–1034]. Cloning of a cDNA coding for otolin‐1 revealed that the deduced amino‐acid sequence contained a collagenous domain in the central part of the protein. Although collagen is the most abundant structural protein in the animal body, otolin‐1 mRNA was expressed specifically in the sacculus. Immunohistochemical studies showed that otolin‐1 is synthesized in the transitional epithelium and transferred to the otolith and otolithic membrane. This is the first report concerning characterization of a structural protein containing many tandem repeats of the sequence, Gly‐Xaa‐Yaa, typical for collagen from the biomineral composed of calcium carbonate.
Seasonal atopic dermatitis in dogs sensitive to a major allergen of Japanese cedar (Cryptomeria japonica) pollen
Authors: Masuda Kenichi , Sakaguchi Masahiro , Saito Saburo , Deboer Douglas J. , Yamashita Kohei , Hasegawa Atsuhiko , Ohno Koichi , Tsujimoto Hajime
Published: July 2002

Abstract Three dogs were examined because of episodes of recurrent pruritic dermatitis in the spring, the season of Japanese cedar (Cryptomeria japonica, CJ) pollination in Japan. The dogs were shown to be sensitive to CJ pollen allergen using intradermal testing and antigen‐specific IgE measurement. Fluorometric enzyme‐linked immunosorbant assay (ELISA) showed increased concentrations of IgE specific to Cry j 1 and a negative result for Cry j 2 in the three dogs. The concentrations of IgE specific to Cry j 1 during the season of CJ pollination were higher than the concentrations found during the off‐season in all the dogs, and the variation in the concentrations correlated with the variation in clinical signs. Peripheral blood mononuclear cells showed apparent proliferative responses to crude CJ pollen antigen and Cry j 1 during CJ pollination season. These findings indicated that Cry j 1 was the major allergen recognized by IgE and lymphocytes and resulted in the development of type I hypersensitivity to CJ pollen allergen in these atopic dogs.
Two cases of inv(8)(p11q13) in AML with erythrophagocytosis: a new cytogenetic variant
Authors: Coulthard Stephanie , Chase Andrew , Orchard Kim , Watmore Ann , Vora Ajay , Goldman John M. , Swirsky David M.
Published: July 2002

We describe two patients with acute myeloid leukaemia (AML) associated with erythrophagocytosis and a pericentric inversion of chromosome 8, inv(8)(p11q13). The haematological features were indistinguishable from those of patients with the t(8;16) syndrome and its variants. Our observations emphasize the importance of the breakpoint at 8p11 and the possible involvement of the MOZ gene in all these cases.
Amygdaloid Corticotropin‐Releasing Factor Targets Locus Coeruleus Dendrites: Substrate for the Co‐ordination of Emotional and Cognitive Limbs of the Stress Response
Authors: Van Bockstaele E. J. , Colago E. E. O. , Valentino R. J.
Published: July 2002

Corticotropin‐releasing factor (CRF), the neurohormone that initiates the endocrine limb of the stress response via its actions on the anterior pituitary, also acts as a neurotransmitter in the noradrenergic locus coeruleus (LC) to activate this system during stress. Because the central nucleus of the amygdala contains numerous CRF‐immunoreactive neurones, the present study examined whether CRF projections from the central nucleus of the amygdala target LC dendrites, thereby providing a mechanism for limbic‐CRF modulation of brain noradrenergic activity. Retrograde tracers injected into the rostrolateral pericoerulear region, where CRF‐immunoreactive fibres are dense, labelled numerous CRF‐immunoreactive neurones in the central nucleus of the amygdala. Consistent with this, ultrastructural analysis of the rostrolateral pericoerulear region in sections that were dually labelled for an anterograde tracer (biotinylated dextran amine, BDA) injected into the central nucleus of the amygdala and CRF immunoreactivity revealed that a substantial percentage (35%) of amygdaloid axon terminals were CRF‐immunoreactive. These terminals formed synaptic specializations with unlabelled dendrites that were more often of the asymmetric (excitatory) type. Additionally, ultrastructural analysis of sections that were dually labelled to visualize CRF‐and tyrosine hydroxlase‐immunoreactivity demonstrated synaptic specializations between CRF‐immunoreactive terminals and LC dendrites in the rostrolateral peri‐LC, which were also frequently asymmetric. Taken together with previous ultrastructural findings that LC dendrites in the rostrolateral pericoerulear region are targeted by anterogradely labelled terminals from the central nucleus of the amygdala, the present results implicate this nucleus as a source of CRF that can impact on LC activity via effects on dendrites in the rostrolateral pericoerulear region. This cellular substrate for amygdaloid‐CRF modulation of brain noradrenergic activity may serve as a mechanism for the integration of emotional and cognitive responses to stress.
Protein–Protein Interactions Between Native Ro52 and Immunoglobulin G Heavy Chain
Authors: YAN Y.‐S. , EVERSOLE T. , Lee D. J. , SONTHEIMER R. D. , CAPRA J. D
Published: July 2002

Using a yeast two‐hybrid system to search for proteins interacting with Ro52 autoantigen, we identified a novel protein–protein interaction. Two different cDNA clones, which interacted with Ro52 in the yeast twohybrid system, were identified and isolated from a human B‐cell library. Surprisingly, both clones encoded the heavy chain of human IgG1. The expression of both HIS3 and b‐galactosidase reporter genes in yeast suggested that the interaction between Ro52 and IgG occurred in vivo. In vitro studies utilizing recombinant Ro52 and purified immunoglobulins indicated that the interaction was immunoglobulin class and subclass specific. Ro52 interacted with IgG1 and IgG4, but not with IgG2, IgG3, IgA or IgM. Ro52 could also precipitate IgG directly from serum. The identified cDNA clones did not include the variable region of IgG, which suggested a non‐classical interaction independent of antibody specificity. We further mapped the domain of Ro52 responsible for this interaction to the C‐terminus rfp‐like region. In conclusion, our data support an unusual interaction between native Ro52 and IgG. The potential biological significance of this unusual protein–protein interaction is discussed.
Increased resistance to oxidative stress in transgenic tobacco plants overexpressing bacterial serine acetyltransferase
Authors: Blaszczyk Anna , Brodzik Robert , Sirko Agnieszka
Published: July 2002

Plant expression cassettes containing theEscherichia coli cysEgene alleles (encoding SAT) were constructed. After theAgrobacterium‐mediated transformation of tobacco, we identified stable transformed plants containing several‐fold higher SAT activity in comparison to the control plant. Determination of non‐protein thiol contents indicated two‐ to threefold higher cysteine and glutathione levels in some of these transgenic plants. The maximal elevation of the cysteine level was about fourfold while that of GSH was about twofold higher than in the controls. The most striking physiological consequence of the modification of sulfur metabolite levels in the transgenic plants, however, was their several‐fold increased resistance to oxidative stress generated by exogenous hydrogen peroxide.
Experimental diabetic nephropathy: Is it relevant to the human disease
Authors: Kelly Darren J , Allen Terri J , Cooper Mark E
Published: July 2002

SUMMARY Diabetic nephropathy is the commonest cause of end‐stage renal failure in the western world. It has been suggested that experimental models of diabetic nephropathy can be used to explore the natural history, pathogenesis and role of various treatments in this condition. Experimental diabetic nephropathy is associated with many but not all of the functional and structural abnormalities observed in human diabetic nephropathy, such as increased glomerular filtration rate, renal hypertrophy, albuminuria and glomerular and tubulointerstitial structural abnormalities. Diabetic nephropathy appears to occur as a result of an interplay of haemodynamic and metabolic factors. Haemodynamic factors include not only systemic and intraglomerular hypertension but also alterations in various vasoactive hormones and their receptors, which may act directly or via effects on blood pressure. Glucose dependent pathways have been implicated in diabetic nephropathy with recent studies focussing on advanced glycation end products and protein kinase C activation. Both glucose and haemodynamic dependent pathways activate a range of cytokines, including transforming growth factor‐β, which appear to play a pivotal role in mediating renal injury. Interventional studies in experimental models of diabetic nephropathy have emphasized the importance of tight glycaemic control and effective blood pressure reduction. In particular, agents that interrupt the renin–angiotensin system have been shown to be renoprotective but whether they are superior to other anti‐hypertensive agents has not been fully clarified. Experimental studies have provided the rationale for a number of clinical trials, which have confirmed the deleterious effects of hyperglycaemia and hypertension on the diabetic kidney. Experimental models of diabetic nephropathy are currently being used to explore more novel compounds which inhibit various pathogenic pathways implicated in the pathogenesis of diabetic nephropathy.
The role of platelet‐derived growth factor in a murine model of crescentic nephritis
Authors: Haseley La , Pippin Jw , Huang Xr , Lan Hy , Gordon Kl , Seifert Ra , Johnson Rj
Published: July 2002

SUMMARY Platelet‐derived growth factor (PDGF) is a major mesenchymal cell mitogen, with an established role in the pathogenesis of experimental mesangial proliferative nephritis. The role of PDGF in experimental models of crescentic glomerulonephritis is not well defined. To study the role of PDGF in glomerular crescent formation, we induced a model of crescentic glomerulonephritis in transgenic mice expressing high concentrations of the soluble external domain of the PDGFβ receptor (PDGF‐Rβ). Crescentic nephritis was induced by the intraperitoneal injection of antibody to whole rabbit glomeruli. At day 7 of disease, biopsies of transgenic and wild‐type mice were evaluated for crescent frequency, crescent area, and thickness of crescent cell layer. In situ hybridization was performed to evaluate the expression of both PDGF B‐chain and PDGFRβ mRNA within crescents. Delivery of soluble receptor to the urinary space was evaluated by Western blotting. Crescent frequency did not differ between wild type and transgenic mice. However, crescent area quantified by computer image analysis was significantly reduced in transgenic mice (P < 0.015). Transgenic biopsies displayed predominantly crescents composed of two cell layers (P = 0.03 compared with wild type), whereas wild‐type biopsies had significantly more crescents composed of four or more cell layers (P = 0.04). Both PDGF B‐chain and PDGF‐Rβ mRNA were detected within crescents in a heterogeneous fashion. Soluble receptor was detectable in the urine of all transgenic diseased mice. We conclude that PDGF plays a role in modulating crescent size and development in our murine model of crescentic nephritis.
EVALUATION OF ASYMPTOMATIC HAEMATURIA OR PROTEINURIA IN A HIGH RISK POPULATION: IS ULTRASOUND USEFUL?
Authors: G Singh , A White , J Spencer , W. Hoy
Published: July 2002

Background: Rates of renal failure in some Aboriginal communities in the Northern Territory are among the highest in the world. Haematuria and proteinuria is also very common but the frequency of structural and parenchymal abnormalities associated with these findings is unclear. Ultrasound examination is common practice for investigation of haematuria/proteinuria. This involves considerable logistic problems and costs for people from remote communities. We conducted a population survey using renal ultrasound in a remote coastal community with high rates of renal disease, to delineate the frequency of abnormal findings.

Methods: Urine dipstick analysis and albumin:creatinine ratio (ACR) were measured in people over 5 years old and a detailed renal ultrasound examination performed.

Results: Forty percent of the population (n = 664) were included, 286 children aged 5‐18 yr (males 152, females 134) and 377 adults aged 19‐70 yr (males 195 females 182) with a representative sample from all age groups. 11% of children and 10.9% of adults had haematuria ( ≥ 1 + ) and 9.8% of children and 43.8% of adults had proteinuria ( ≥ 1 + ) on urinalysis. Macroalbuminuria (ACR ≥ 34) was present in 21% of adults and 1.4% of children. Microalbuminuria (ACR ≥ 3.4) was present in 49% of adults and in 6.9% of children On ultrasound exam, no abnormal echotexture, medullary abnormalities, poor cortico‐medullary differentiation, marked L/R differ‐ences in size, or dilatation of the collecting system were found. Seven structural abnormalities were identified (2 simple cysts, 1 scar on an upper pole, 1 right dysplastic kidney and 3 people with polycystic kidneys, already recognised). None of these abnormal findings led to a change in management.

Conclusion: In view of the low yield of abnormal findings the use of routine ultrasounds for asymptomatic urinary abnormalities in such population might be re‐evaluated. Ultrasound might be reserved for people with special features, such as gross haematuria, rapid change in renal function, severe hypertension, elevated creatinine, clinical symptoms etc or in anticipation of a renal biopsy.
Randomized controlled trial of brain‐derived neurotrophic factor in Guillain–Barré syndrome: a pilot study
Authors: Bensa S. , Hadden R. D. M. , Hahn A. , Hughes R. A. C. , Willison H. J.
Published: July 2002

Brain‐derived neurotrophic factor (BDNF) has the theoretical potential to protect neurones from axonal degeneration. The objective of this study was to discover whether brain‐derived neurotrophic factor is safe in Guillain–Barré syndrome, and to make preliminary observations of its efficacy. This was a parallel group randomized controlled trial of subcutaneous brain‐derived neurotrophic factor 25 µg/kg daily compared with placebo for up to 24 weeks or until patients could walk without aid.

Six patients received brain‐derived neurotrophic factor, of whom three had serious adverse events including one death. Four patients received placebo, of whom two had serious adverse events including one death. The rate and extent of recovery were similar in the two groups.

This pilot study did not detect any serious adverse events attributed to brain‐derived neurotrophic factor treatment.
Effect of Experimental Selective Logging on Tropical Butterflies
Authors: Lewis Owen T.
Published: July 2002

Abstract: I investigated the effects of an experimental selective logging regime on the assemblage of fruit‐feeding butterflies in replicated experimental plots in the Chiquibul Forest, Belize. Over a 12‐month period, I caught 1187 individuals of 49 species using fruit‐baited traps. Selective logging at densities of six stems per ha 3 years before the study had little effect on butterfly species richness, the abundance of individual species, or the shape of species‐abundance distributions. There was no tendency for taxa with restricted geographical ranges to be particularly sensitive to selective logging. Mark‐release‐recapture results suggest that most butterflies move relatively short distances, but that some dispersal occurs between plots separated by distances of ≥1 km. The apparent similarity of the fruit‐feeding butterfly assemblage in selectively logged and unlogged forest contrasts with previous studies of butterfly assemblages but mirrors results for birds in the same plots. A possible explanation is the high frequency of natural disturbance—hurricanes and associated fires—in the Chiquibul Forest. The species present appear to be adapted to naturally disturbed habitats and may therefore be relatively unaffected by selective logging. Local studies of the effects of selective logging must take into account the history of natural and human disturbance in the study area. The results support the case for “ecological forestry,” in which sustainable management regimes work within the limits imposed by natural disturbance.
PERIPHERAL AND CENTRAL NERVOUS SYSTEM LYMPHOMA PRESENTING AS MULTIPLE CRANIAL AND PERIPHERAL RADICULONEUROPATHY
Authors: Di Troia A. , Carpo M. , Ghidoni P. , Scarlato G. , Nobile‐Orazio E.
Published: July 2002

A 58 y.o. man was admitted to our hospital because of severe progressive untreatable radicular pain, limb weakness, and cranial nerve palsies. The patient was well until 2 years before, when he developed progressive perineal sensory loss with impotence. Two months later, he complained of pain in the right foot only partially responding to NSAIDs. A lumbosacral MRI showed a spinal stenosis and multiple lumbar discopathy. During the following year he developed right foot and left arm burning paresthesia only responsive to oral opiates, left facial nerve palsy, right foot drop, arm weakness partially responding to oral steroids, and cyclophosphamide. CSF and electrophysiological studies were consistent with an inflammatory multiple radiculoneuropathy while blood tests, bone scintigraphy, and abdominal echography were normal. Four months before admission, he developed right wrist drop, painful dysesthesia in the left hemithorax, and diplopia. On admission, neurologic examination revealed left oculomotor and facial nerve palsies, distal>proximal weakness in the extensor muscles of the right arm, right foot drop, superficial and deep sensory loss on the right leg, and ubiquitary absent deep tendon reflexes. Four additional spinal taps revealed markedly increased proteins with slightly increased cells (always below 10/mm3) but no tumor cell. Nerve conduction studies were consistent with multiple radiculoneuropathy, while sural nerve biopsy showed an axonal neuropathy. Bone marrow biopsy, chest and abdominal CT, and endoscopy of the gastrointestinal tract were negative for neoplastic lesions. A brain and cervical MRI revealed multiple gadolinium enhancing hyperlucencies in the thalamus, caudate nucleus, and spinal cord. The patient was treated with intravenous steroids and IVIg with no response and with opiates for severe pain. One month later, the patient developed deep vein thrombosis treated with anticoagulants followed four days later by a fatal massive intracranial hemorrhage. Autoptic studies revealed a widespread non‐Hodgkin's type B lymphoblastic centrocitic lymphoma involving the stomach, liver, lung, thyroid, spleen, cauda equina, brain, and the spinal cord.

This report draws attention to the unusual presentation of a lymphoproliferative disease that escaped an extensive diagnostic evaluation during life.
SENSORY MANIFESTATIONS IN CHARCOT‐MARIE‐TOOTH DISEASE
Authors: Gemignani F. , Ferraris A. , Alfieri S. , Bellanova M.F. , Marbini A.
Published: July 2002

Although positive sensory symptoms are classically considered a hallmark of acquired neuropathies, sensory manifestations, in particular, pain, are not uncommon in Charcot‐Marie‐Tooth disease (CMT).

We investigated the occurrence of sensory manifestations in 35 CMT patients (15 with CMT1, 20 with CMT2).

Positive sensory manifestations were reported by 18 patients (51%), and were prominent in 7 patients (20%), representing an onset symptom and/or a main feature. Non‐neuropathic (musculo‐skeletal) pain was also frequent, occurring in 48% of patients. Comparison between CMT1 and CMT2 showed that positive sensory symptoms were significantly more frequent in CMT2 (70% versus 27%; p = 0.018), representing a prominent clinical feature in 25% of CMT2 patients. Non‐neuropathic pain was more frequent in CMT1 (60%) than in CMT2 patients (40%), and represented an onset symptom and/or a main feature in 33% and 25% of patients, respectively.

Sensory manifestations in CMT seem more frequent than previously thought, however their frequency may be different in the genetic subtypes of the disease. The occurrence of positive symptoms in CMT2 raises diagnostic problems with regard to acquired axonal neuropathies, and, in particular, chronic idiopathic axonal polyneuropathy (CIAP). Sensory symptoms, in particular, pain, may represent an important issue in the management of CMT patients, especially in a physical medicine approach.
TAXOL NEUROTOXICITY: CELLULAR MECHANISMS INVOLVED IN APOPTOSIS
Authors: Nicolini G. , Saccomanno D. , Scuteri A. , Rigamonti L. , Galbiati S. , Miloso M. , Cavaletti G. , Tredici G.
Published: July 2002

The antineoplastic drug paclitaxel (Taxol™) is neurotoxic on the peripheral nervous system. Both activity and neurotoxicity of paclitaxel are due to enhancement in tubulin polymerization. In addition, it has been demonstrated that paclitaxel induces gene expression. To elucidate the signal transduction pathways involved in paclitaxel neurotoxicity we studied in vitro the effect(s) of paclitaxel on the human neuroblastoma (HN) SH‐SY5Y cells, which express genes associated with neuronal differentiation and may be considered neuroblasts at various stages of maturation.

The exposure of SH‐SY5Y cells to paclitaxel produces apoptosis, as demonstrated with Annexin V assay and orange acridin staining. Electron microscopy showed typical condensation of nuclear chromatin with normal nuclear membrane. DNA electrophoresis confirmed the occurrence of apoptosis by demonstrating the typical laddering.

We studied regulator proteins as Bcl‐2 and c‐raf, and investigated the classes of caspases activated in this process by immunoblotting. We observed that 1μM paclitaxel induces a simultaneous phosphorylation of c‐raf and Bcl‐2, thus causing Bcl‐2 inactivation. Caspase 3, which is commonly present and activated in the nervous cells, was not activated, while paclitaxel‐induced apoptotic process in SH‐SY5Y cells is induced by activation of caspase 7. The involvement of caspase 7 is also confirmed by the same pattern of cleavage of PARP. Finally, we also studied MAPKs, a family of serine/threonine kinases that represent key signaling proteins known to be involved in many cellular events, including apoptosis.

Our results indicate that paclitaxel does not activate ERK cascade, whereas it induces JNK/SAPK and p38 phosphorylation, suggesting that these specific pathways are involved in the cell‐death induced by paclitaxel.
PERIPHERAL NEUROPATHY IN HEPATITIS C VIRUS INFECTED PATIENTS WITH AND WITHOUT MIXED CRYOGLOBULINEMIA
Authors: Sampaolo S. , Ambrosone L. , Franzese G. , De Martino L. , Panella G. , Migliaresi S. , Di Iorio G.
Published: July 2002

Objective: To evaluate immunohistochemical and ultrastructural changes in sural nerve biopsies from patients with peripheral neuropathy and hepatitis C virus (HCV) infection.

Methods: Frozen and plastic‐embedded nerve specimens were obtained from 19 HCV‐positive patients with (16) or without (3) mixed cryoglobulinemia (MC). Immunoperoxidase and immunofluorescence studies were performed on cryostat cross‐sections using antibodies recognising cellular subsets and humoral factors involved in the inflammation (CD68, CD11a‐b‐c, CD20, CD3, CD4, CD45, C1q, C3d, TCC, IgG, IgA, IgM). Semi and ultrathin sections were studied by standard protocols.

Results: Nerve biopsy showed an axonal degeneration with micro‐ angiopathy (perineurial > endoneurial). IgM and IgG were observed as a thin sub‐perineurial band and in the wall of endo and perineurial vessels in MC patients only. Immunoglobulin deposition colocalised in some nerves with complement factors. Macrophages and T memory/activated lymphocytes were seen perivascularly and in endoneurium while rare B‐cells were detected in perineurium. In the MC‐negative patients, the peripheral neuropathy was characterised by a prominent myelin degeneration. The pattern of distribution of immunoreactivity for humoral and cellular factors was similar but not identical to that of MC patients.

Conclusions: Axonal degeneration characterises the HCV‐related MC neuropathy and is likely secondary to ischaemia. The vascular damage is prevailing in perineurium and appears to be mediated by both T‐cells and immune complex. Myelin alterations mainly occur in MC‐negative patients. These last findings suggest a primary pathogenetic role for HCV in the induction of the nerve damage.
ACTIVES RELIEF MANEUVERS IN CARPAL TUNNEL SYNDROME
Authors: Manente G. , Staniscia T. , Ragno M. , Pineto F. , Romano F. , Uncini A.
Published: July 2002

In 1999 we described a maneuver, called Carpal Tunnel Syndrome Relief Maneuver (CTS‐RM), which eases or abolishes paresthesias or pain in carpal tunnel syndrome by gently squeezing the distal heads of the metacarpal bones (excluding the first) and stretching the third and fourth fingers. For the same purpose we recently developed two active counter‐resistance maneuvers which we called Carpal Tunnel Actives Relief Maneuvers (CTS‐ARMs).

In CTS‐ARM n. 1 the patient uses maximum effort to bring digit I closer to digits IV and V (which should touch), while the examiner offers maximum resistance. On the contrary in CTS‐ARM n. 2, the patient uses maximum effort to distance digit I from digit IV and V (which should touch), while the examiner offers maximum resistance.

To verify the efficacy of these maneuvers we enrolled 81 consecutive patients (120 hands) with CTS symptoms and signs and abnormal electrodiagnostic study. At clinical examination 38 patients (47%), 11 men and 27 women, complained of paresthesias in 54 hands (45%). In these patients we performed the three maneuvers: (1) the CTS‐RM; (2) the CTS‐ARM n.1 and (3) CTS‐ARM n. 2. The CTS‐ARMs 1 and 2, were successful in 51 hands (94%). In 40 hands (74%) there was complete abolition and in 11 (20%) improvement of paresthesias in a few seconds. In 3 hands (5.6 %) the CTS‐ARMs did not improve or worsen the paresthesias. The three maneuvers had almost the same results except in the three hands in which the CTS‐RM improved the paresthesias whereas CTS‐ARMs did not.

We believe that the CTS‐ARMs may reduce compression and ischemia of the median nerve by stretching and raising the transverse carpal ligament. The CTS‐ARMs may help in clinical diagnosis of CTS, can be useful to relieve symptoms and provide the rationale for therapeutic hand exercises in CTS.
PERCUTANEOUS THERMORHIZOTOMY IN A CLINICAL SERIES OF 80 PATIENTS WITH TRIGEMINAL NEURALGIA.
Authors: Rychlicki F. , Ricciuti R.A. , Dobran M. , Morabito L. , Mora A. , Pauri F. , Trignani R. , Veronesi V. , Firetto V. , Caputi C.A.
Published: July 2002

At the time of this report, 80 patients have been operated upon for typical trigeminal neuralgia by the percutaneous rhizotomy approach. Through follow‐up evaluation extending over a period of 1 to 20 years, it has been completed for 65 of these patients. The average age was 63 years and 60% of patients were female. In 60% of patients pain was located on the right, and the second and third division of the trigeminal nerve were commonly involved. Isolated pain in the first or third division was less frequent than the second division. The disease had been present for an average of 8 years and was characterized by increasingly severe episodes of paroxismal pain and shortening period of remission. Nearly all patients had been treated with either diphenylhydantoin or carbamazepine, as well as other forms of medical and physical remedies. Response to follow‐up was obtained for all 65 patients. All were contacted by questionnaire on phone and a family member was contacted if the patient had died. At the time of evaluation, 94% of patients reported excellent to good results from the procedure. The remaining patients obtained only fair results because of undesirable side‐effects or recurrence of pain. The authors emphasize the importance of surgical therapy in trigeminal neuralgia when medical therapy fails.
DISOPYRAMIDE‐INDUCED NEUROPATHY
Authors: Briani C. , Zara G. , Ruggero S. , Negrin P.
Published: July 2002

Neuropathies are well‐known complications of therapy with amiodarone, but other antiarrhythmic drugs are rarely associated with neurological side effects. We report a patient who developed a severe sensory‐motor neuropathy after treatment with disopyramide.

A 71 year‐old woman, who had been treated with disopyramide 500 mg/day for 4 years for cardiac arrythmias, presented with fatigue, paresthesias, and pain in her lower limbs. Morning stiffness and arthralgias were also present. On neurological examination, her gait was unsteady, and weakness was present in the 4 limbs; tendon reflexes were reduced in the upper limbs and lost in the lower limbs. C‐reactive protein was increased. Electrodiagnostic studies revealed a sensory‐motor polyneuropathy, with reduced motor conduction velocity (MCV) in peroneal nerves (38 m/sec) with normal compound muscle action potential (CMAP) amplitude. There was some evidence of muscle denervation, with fibrillation at rest and reduced patterns on maximal contraction; no sensitive potential was recorded from sural nerves.

Antibodies to peripheral nerve antigens (gangliosides, sulfatides, MAG, glycosaminoglycans) resulted negative. A diagnosis of polymyalgia rheumatica was made and steroid started with a prompt recovery of arthralgias and stiffness. Weakness and dysesthesias in the legs, however, worsened and an electrophysiological study, three months later, evidenced a more severe peripheral neuropathy, with a slower MCV (31 m/sec) and signs of denervation. After excluding other known causes of neuropathy, disopyramide was withdrawn. Four months later, the patient showed a significant improvement of the symptoms and of electrophysiological studies, with peroneal nerve MCVs of 40 m/sec and reappearance of the excitability of the sural nerves (43 m/sec). This is, to our knowledge, the second case of a disopyramide‐induced polyneuropathy so far reported. Although uncommon, it should be considered when polyneuropathy occurs and no other causes are found. If possible, the discontinuation of the therapy might help in clarifying the diagnosis and curing the neuropathy.
Musculoskeletal Pain and Risk for Falls in Older Disabled Women Living in the Community
Authors: Leveille Suzanne G. , Bean Jonathan , Bandeen‐Roche Karen , Jones Rich , Hochberg Marc , Guralnik Jack M.
Published: July 2002

OBJECTIVES:

To determine whether musculoskeletal pain increased risk for falls in older women with disabilities.

DESIGN:

Prospective population‐based cohort study.

SETTING:

The city and county of the eastern area of Baltimore.

PARTICIPANTS:

One thousand two women aged 65 and older, participants in the Women's Health and Aging Study, representing the one‐third of older women who were living at home with disabilities, followed semiannually for 3 years beginning in 1991.

MEASUREMENTS:

Pain was categorized into four groups according to severity and location. Widespread pain was defined as pain in the upper and lower extremities and in the axial skeletal region, with moderate to severe pain in at least one region (≥ 4 on a 10‐point numeric rating scale, 10 = excruciating pain). Moderate to severe lower extremity pain that did not meet criteria for widespread pain was the next category. The reference category was no pain or mild pain in one site. The additional category of “other pain” was pain that did not fit into the other three groups. The occurrence of falls and fall‐related injuries were assessed at each interview.

RESULTS:

Of the 940 women who participated in at least one follow‐up examination, 39% fell in first year; of the survivors, 36% fell in Year 2, and 39% in Year 3. After adjusting for several major risk factors for falls, women with widespread pain had an increased likelihood of falling during follow‐up (adjusted odds ratio (AOR) = 1.66, 95% confidence interval (CI) = 1.25–2.21) compared with those with no or mild pain in only one musculoskeletal site. Women who had other musculoskeletal pain but not widespread pain or lower extremity pain also had an increased risk of falls (AOR = 1.36, 95% CI = 1.02–1.82). Among women with musculoskeletal pain, risk for falls was lower in those who used daily analgesic medication. Risk for recurrent falls and self‐reported fractures due to falls was also elevated in women with musculoskeletal pain, most consistently in women with widespread pain.

CONCLUSIONS:

Musculoskeletal pain, particularly widespread pain, is a substantial risk factor for falls in older women with disabilities. These findings add an important dimension to our understanding of the multifactorial processes leading to falls in older persons. J Am Geriatr Soc 50:671–678, 2002.
High T
c superconductivity in Y-Ba-Cu-O screen-printed films
Authors: Sacchi Maurizio , Sirotti Fausto , Morten Bruno , Prudenziati Maria
Published: July 2002

We have prepared screen-printed films of the Y-Ba-Cu-O compound on BeO and Al2O3 ceramic substrates. Transition to full superconductive state was obtained for all the samples. The related parameters (Tonset, Tc, ΔT) and some structural properties are reported.
Dislocation density reduction by isoelectronic impurities in semiconductors
Authors: Walukiewicz W.
Published: July 2002

A new mechanism for dislocation density reduction by isoelectronic doping is proposed. It is shown that the strain introduced by randomly distributed dopants lowers the vacancy supersaturation impeding dislocation formation via vacancy condensation. Trends in dislocation reduction through codoping with isoelectronic and electrically active impurities are discussed for the case of GaAs doped with indium.
Power scaling of large-area transverse radio frequency discharge CO2 lasers
Authors: Abramski K. M. , Colley A. D. , Baker H. J. , Hall D. R.
Published: July 2002

We report experimental results on gain medium area scaling of laser output power for large-area, transverse rf discharge excited carbon dioxide lasers. Power extraction to 20 kW/m2 has been achieved, indicating the significant potential of this technique.
Large lateral photovoltaic effect in modulation-doped AlGaAs/GaAs heterostructures
Authors: Tabatabaie N. , Meynadier M.-H. , Nahory R. E. , Harbison J. P. , Florez L. T.
Published: July 2002

We describe a large lateral photovoltage that develops in AlGaAs/GaAs modulation-doped structures in response to excitation by spot illumination. The effect is observed in wafers where the equilibrium inversion channel electron density is negligibly small. This effect is sensitive to the position of the illuminated spot. The dependence of the induced photovoltage on the power and the spectral composition of the excitation as well as its temperature dependence has been carefully studied. A resistive two-channel transmission line model has been developed to explain the experimental results.
Independently contacted two-dimensional electron systems in double quantum wells
Authors: Eisenstein J. P. , Pfeiffer L. N. , West K. W.
Published: July 2002

A new technique for creating independent ohmic contacts to closely spaced two-dimensional electron systems in double quantum well (DQW) structures is described. Without use of shallow diffusion or precisely controlled etching methods, the present technique results in low-resistance contacts which can be electrostatically switched between the two-conducting layers. The method is demonstrated with a DQW consisting of two 200 Å GaAs quantum wells separated by a 175 Å AlGaAs barrier. A wide variety of experiments on Coulomb and tunnel-coupled 2D electron systems is now accessible.