bluuebunny/crossref_metadata_2025 huggingface dataset:
Individual, household, programme and community effects on childhood malnutrition in rural India
Authors: Rajaram S. , Zottarelli Lisa K. , Sunil T.S.
Published: March 2007

The children living in rural areas of India disproportionately suffer from malnutrition compared with their urban counterparts. The present article analyses the individual, household, community and programme factors on nutritional status of children in rural India. Additionally, we consider the random variances at village and state levels after introducing various observed individual‐, household‐ and programme‐level characteristics in the model. A multilevel model is conducted using data from the National Family and Health Survey 2. The results show that maternal characteristics, such as socio‐economic and behavioural factors, are more influential in determining childhood nutritional status than the prevalence of programme factors. Also, it was found that individual factors show evidence of state‐ and village‐level clustering of malnutrition.
Distribution of CCR2 polymorphism in HIV‐1‐infected and healthy subjects in North India
Authors: Kaur G. , Singh P. , Kumar N. , Rapthap C. C. , Sharma G. , Vajpayee M. , Wig N. , Sharma S. K. , Mehra N. K.
Published: March 2007

Substitution of V64I in CCR2 relates to delayed progression to AIDS and protects against HIV‐1 infection. We examined the distribution of V64I in HIV‐infected and healthy North Indian subjects. No significant difference in the allele or genotype distribution of CCR2 V64I polymorphism was observed, indicating that there is no association between CCR2 V64I polymorphism and susceptibility to HIV infection in North Indian population.
Bioassay and Identification of Root Exudates of Three Fruit Tree Species
Authors: Zhang Jiang‐Hong , Mao Zhi‐Quan , Wang Li‐Qin , Shu Huai‐Rui
Published: March 2007

A laboratory bioassay was designed to determine the allelopathic potential of root exudates of three fruit tree species on apple germination. The results showed that root exudates of apple (Malus pumila L.) and peach (Prunus persica L.), each at concentrations of 0.02 and 0.2 mg/L, inhibited germination and radicle growth of apple seeds by 56.7%, 60.7%, 51.5%, and 59.3%, respectively. The corresponding shoot growth inhibition rate was 49.5%, 46.7%, 36.4%, and 44%, respectively. Root exudates of jujube (Ziziphus jujuba Mill.) had no significant effect on apple seeds. Qualitative determination of root exudates of apple, peach, and jujube tree was developed with gas chromatography‐mass spectrometry. The root exudates of apple seedlings mainly contain organic acids, glycol, esters, and benzenphenol derivatives. Peach root exudates contained phenolic acids and benzenphenol derivatives in addition to two unidentified compounds. The root exudates of jujube did not contain any phenolic acids.
Genetic Diversity: Geographical Distribution and Toxin Profiles ofMicrocystisStrains (Cyanobacteria) in China
Authors: Wu Zhong‐Xing , Gan Nan‐Qin , Song Li‐Rong
Published: March 2007

Twenty strains ofMicrocystisKütz were isolated from different freshwater bodies in China to analyze the diversity, geographical distribution and toxin profiles. Based on whole‐cell polymerase chain reaction ofcpcBA‐IGS nucleotide sequence, the derived neighbor‐joining (NJ) and maximum parsimony (MP) trees indicate that these strains ofMicrocystiscan be divided into four clusters. The strains from south, middle and north region of China formed distinct lineages, suggesting high diversity and a geographical distribution from south to north locations. Moreover, the results being indicating high variable genotypes of the strains of theMicrocystisstrains from the same lake show that there is high diversity ofMicrocystiswithin a water bloom population. Comparing the results of the present study with those reported for compared with 43 strains ofMicrocystisfrom other locations, also reveals Chinese strains have high similarity with those from regions in the North Hemispherical. This suggests that theMicrocystisstrains in the world might have a geographical distribution. Analysis of 30 strains using the primers MCF/TER and TOX2P/TOX2M showed that there was no correlation between the gene ofcpcBA‐IGS and the presence ofmcy.Toxic strains were founded to be predominant in different water bodies throughout China.
Purification and Characterization of a New Heme‐Binding Protein (HBP59) from the Mutant Strain DJ35 of Azotobacter vinelandii
Authors: Bian Shao‐Min , Wang Huang‐Ping , Zhou Hui‐Na , Zhao Ying , Zhao Jian‐Feng , Huang Ju‐Fu
Published: March 2007

A new protein, an approximately 59‐kDa monomer containing iron atoms, was first isolated from the mutant strain DJ35 of Azotobacter vinelandii Lipmann. After analysis by matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry, the protein was identified as the product of a predicted gene. Thus, the protein was tentatively called HBP59. Its absorption spectra (ABS) in the reduced state exhibited three peaks at 421, 517, and 556 nm and the maximal peak was shifted from 421 to 413 nm after exposure of HBP59 to air. The Soret circular dichroism (CD) spectrum of HBP59 in the reduced state displayed four positive peaks at 364, 382, 406, and 418 nm and two negative peaks at 398 and 433 nm; the Δε (CD extinction coefficient) values of these peaks were found to be 0.92, 0.58, 0.87, 0.72, −0.65 and −1.12 L/mol per cm, respectively. Titration with heme showed that the protein has 0.1 heme molecules/protein molecule. After HBP59 had fully interacted with heme, its maximal ABS value and Soret CD intensity were increased by approximately 10‐fold compared with values before interaction. Therefore, it seems that one molecule of HBP59 can be interacted with only one heme. These results indicate that HBP59 contains heme with low spin and may be involved in heme utilization or adhesion.
Genetic Mapping of Laminaria japonica and L. longissima Using Amplified Fragment Length Polymorphism Markers in a “Two‐Way Pseudo‐Testcross” Strategy
Authors: Li Yuhui , Yang Yingxia , Liu Jidong , Wang Xiuliang , Gao Tianxiang , Duan Delin
Published: March 2007

With a “two‐way pseudo‐testcross” mapping strategy, we applied the amplified fragment length polymorphism (AFLP) markers to construct two moderate density genetic linkage maps for Laminaria. The linkage maps were generated from the 60 progenies of the F1 cross family (Laminaria longissima Aresch. ×L. japonica Miyabe) with twenty pairs of primer combinations. Of the 333 polymorphic loci scored in 60 progenies, 173 segregated in a 1:1 ratio, corresponding to DNA polymorphisms heterozygous in a single parent, and the other 58 loci existing in both parents followed a 3:1 Mendelian segregation ratio. Among the loci with 1:1 segregating ratios, 79 loci were ordered in 14 linkage groups (648.6 cM) of the paternal map, and 72 loci were ordered in 14 linkage groups (601.9 cM) of the maternal map. The average density of loci was approximately 1 per 8 cM. To investigate the homologies between two parental maps, we used 58 loci segregated 3:1 for further analysis, and deduced one homologous linkage group. The linkage data developed in these maps will be useful for detecting loci‐controlling commercially important traits for Laminaria.
Assessment of Genetic Stability Among In Vitro Plants of Arachis retusa Using RAPD and AFLP Markers for Germplasm Preservation
Authors: Gagliardi Rachel Fatima , Hanai Luiz Ricardo , Pacheco Georgia , Oliveira Carlos Alberto , Carneiro Leonardo Alves , Montenegro Valls José Francisco , Mansur Elisabeth , Vieira Maria Lucia Carneiro
Published: March 2007

Arachis retusa Krapov. et W. C. Gregory et Valls is endemic in the West‐central region of Brazil, occurring in areas endangered by human actions. The establishment of in vitro preservation methods for wild species of Arachis is an alternative to seed banks for germplasm storage, multiplication and distribution. The risk of genetic changes induced by tissue culture and the monitoring of the genetic stability of the biological material before, during and after storage must be considered in the context of conservation. Random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) fingerprinting were used to evaluate the genetic stability of in vitro plants originated from cotyledons and embryo axes of A. retusa. Cotyledons originated shoots through direct organogenesis and embryo axes displayed multishoot formation induced by 110 mmol/L and 8.8 mmol/L BAP, respectively. Ninety genomic regions (loci) generated from RAPD and 372 from AFLP analyses were evaluated. All amplified fragments detected by both techniques in plants derived from the two explant types were monomorphic. The results indicate that the recovered shoots are genetically stable at the assessed genomic regions.
Changes of 5′ Terminal Nucleotides of PCR Primers Causing Variable T‐A Cloning Efficiency
Authors: Liu Mei‐Qin , Shen Xin , Yin Wei‐Lun , Lu Cun‐Fu
Published: March 2007

T‐A cloning takes advantage of the unpaired adenosyl residue added to the 3′ terminus of amplified DNAs by Taq and other thermostable DNA polymerase and uses a linearized plasmid vector with a protruding 3′ thymidylate residue at each of its 3′ termini to clone polymerase chain reaction (PCR)‐derived DNA fragments. It is a simple, reliable, and efficient ligation‐dependent cloning method for PCR products, but the drawback of variable cloning efficiency occurs during application. In the present work, the relationship between variable T‐A cloning efficiency and the different 5′ end nucleotide base of primers used in PCR amplification was studied. The results showed that different cloning efficiency was obtained with different primer pairs containing A, T, C and G at the 5′ terminus respectively. The data shows that when the 5′ end base of primer pair was adenosyl, more white colonies could be obtained in cloning the corresponding PCR product in comparison with other bases. And the least white colonies were formed when using the primer pair with 5′ cytidylate end. The gluanylate end primers resulted in almost the same cloning efficiency in the white colonies amount as the thymidylate end primer did, and this efficiency was much lower than that of adenosyl end primers. This presumably is a consequence of variability in 3′dA addition to PCR products mediated by Taq polymerase. Our results offer instructions for primer design for researchers who choose T‐A cloning to clone PCR products.
Fluctuation of Vegetative Storage Proteins in the Seedlings of Swietenia macrophylla, Analogous to the Seasonal Changes of Those in the Shoot of the Adult Tree
Authors: Han Ya‐Qin , Yan Xing‐Fu , Zhang Hua , Hu Zheng‐Hai , Hao Bing‐Zhong , Tian Wei‐Min
Published: March 2007

In order to identify appropriate plant materials for studying the gene expression and biological function of vegetative storage proteins (VSPs) in woody plants, the VSPs in the seedlings of Swietenia macrophylla King were investigated by using light microscopy, sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) and Western‐blotting. The seed of S. macrophylla was rich in storage proteins that accumulated in the vacuoles of cotyledon parenchyma cells in appearance of compact spherical grains. The growth and development of S. macrophylla seedlings were characterized by an obvious growth rhythm. The storage proteins in seeds disappeared during seedling growth while VSPs appeared in the stem 2 weeks after seedling leaves matured. Thereafter, the VSPs in the seedling stem almost exhausted during new shoot growth, and when the leaves of new shoot just matured, both the stem beneath the new shoot of seedlings and the stem of new shoot started to accumulate VSPs. Nitrogen application dramatically increased the level of VSPs, but had little influence on the dynamics of VSP consumption and accumulation in seedling stem. Together with these data, the fluctuation of VSPs in seedlings was very similar to that in the branches of the adult trees. In addition, seedlings are easy to be treated due to their small size. Our results suggested that S. macrophylla seedlings were suitable for investigating the biological roles of VSPs and the mechanism of nitrogen storage in trees.
Diffuse waves in solids: Can you hear the texture of a crystal?
Authors: Norris Andrew
Published: March 2007

Diffuse waves are a steady state reverberation that partitions energy equally among modes of a system. In an isotropic solid of infinite extent the equipartition defines a well known equation for the spectral density d, which is proportional to the square of the frequency. The proportionality factor depends on the material properties through an average of the inverse third power of the wave speeds. This talk describes the analogous equation for diffuse wave density in a crystal. The first result is that the density d is a matrix or tensor quantity, which possesses the material symmetry of the solid. The properties of the matrix are discussed both for the forward problem of determining d for a given anisotropic material, and the inverse question of what information can be derived from d about the local material texture. The general form of the spectral density presented is related to the admittance matrix for a point force, as will be explained.
Methods for studying seismic communication in elephants and other large mammals: Arrays, census techniques and more
Authors: Wood Jason D. , O’Connell-Rodwell Caitlin E. , Puria Sunil , Klemperer Simon L.
Published: March 2007

Studying seismic communication poses unique methodological challenges. Methods for producing and monitoring seismic signals will be presented in the context of elephant seismic playback studies as well as large mammal footfall recordings for the purpose of censusing populations remotely. The use of multiple sensors in an array allows for a number of analyses to be conducted to determine the propagation of the signal. Specifically, arrays allow for the measurement of wave velocity and attenuation as well as determination of the mode of propagation. In addition, time of arrival differences can also be used to estimate the source of the signal which has important implications for measuring signal attenuation and in using seismic cues to estimate the number of animals in a group. One challenge in seismic playback studies is to ensure that there is no acoustic coupling of the seismic signal playback, the presence of which would make it impossible to rule out that any behavioral reactions of the study species are due to the acoustic signal that has leaked from the substrate. Matched filtering techniques have been used to detect any playback signal in the acoustic recording of the playback.
Movement discrimination after intra-articular local anaesthetic of the ankle joint
Authors: Down Stuart , Waddington Gordon , Adams Roger , Thomson Malcolm
Published: March 2007

Background:The effect on clinical safety of dampening articular mechanoreceptor feedback at the ankle is unknown. Injection of the ankle joint for pain control may result in such dampening. Athletes receiving intra-articular local anaesthetic may therefore be at increased risk of sustaining ankle injuries, which are a common reason for missed sporting participation.

Objective:To determine the effect of intra-articular local anaesthetic on movement discrimination at the ankle joint.

Design:Prospective, randomised, double-blinded, placebo-controlled, cross-over trial.

Setting:Australian Institute of Sport Medical Centre, Canberra, Australia.

Patients:Twenty two healthy subjects (44 ankles) aged 18–26 were recruited for the three visits of the study.

Interventions:Subjects were tested for their initial movement discrimination scores using the active movement extent discrimination apparatus (AMEDA). They then received ultrasound-guided intra-articular injections of local anaesthetic (2% lignocaine hydrochloride) or normal saline, on two separate later occasions, before further AMEDA assessment.

Main outcome measures:Change in movement discrimination scores after intra-articular injection of local anaesthetic or saline.

Results:Movement discrimination scores were not significantly different from control ankles after injection of either local anaesthetic or saline into the ankle joint.

Conclusions:The intra-articular injection of neither 2 ml lignocaine nor an equivalent amount of normal saline resulted in significant effects on movement discrimination at the ankle joint. These results suggest that injections of local anaesthetic into the ankle joint are unlikely to significantly affect proprioception and thereby increase injury risk.
Comparison of nine theoretical models for estimating the mechanical power output in cycling
Authors: González-Haro Carlos , Galilea Ballarini P A , Soria M , Drobnic F , Escanero J F
Published: March 2007

Objective:To assess which of the equations used to estimate mechanical power output for a wide aerobic range of exercise intensities gives the closest value to that measured with the SRM training system.

Methods:Thirty four triathletes and endurance cyclists of both sexes (mean (SD) age 24 (5) years, height 176.3 (6.6) cm, weight 69.4 (7.6) kg and Vo2max61.5 (5.9) ml/kg/min) performed three incremental tests, one in the laboratory and two in the velodrome. The mean mechanical power output measured with the SRM training system in the velodrome tests corresponding to each stage of the tests was compared with the values theoretically estimated using the nine most referenced equations in literature (Whitt (Ergonomics1971;14:419–24); Di Pramperoet al(J Appl Physiol1979;47:201–6); Whitt and Wilson (Bicycling science. Cambridge: MIT Press, 1982); Kyle (Racing with the sun. Philadelphia: Society of Automotive Engineers, 1991:43–50); Menard (First International Congress on Science and Cycling Skills, Malaga, 1992); Oldset al(J Appl Physiol1995;78:1596–611;J Appl Physiol1993;75:730–7); Broker (USOC Sport Science and Technology Report1–24, 1994); Candauet al(Med Sci Sports Exerc1999;31:1441–7)). This comparison was made using the mean squared error of prediction, the systematic error and the random error.

Results:The equations of Candauet al, Di Pramperoet al, Oldset al(J Appl Physiol1993;75:730–7) and Whitt gave a moderate mean squared error of prediction (12.7%, 21.6%, 13.2% and 16.5%, respectively) and a low random error (0.5%, 0.6%, 0.7% and 0.8%, respectively).

Conclusions:The equations of Candauet aland Di Pramperoet algive the best estimate of mechanical power output when compared with measurements obtained with the SRM training system.
Hepatocyte nuclear factor-4α regulates the human organic anion transporter 1 gene in the kidney
Authors: Ogasawara Ken , Terada Tomohiro , Asaka Jun-ichi , Katsura Toshiya , Inui Ken-ichi
Published: March 2007

Human organic anion transporter 1 (OAT1, SLC22A6), which is localized to the basolateral membranes of renal tubular epithelial cells, plays a critical role in the excretion of anionic compounds. OAT1 is regulated by various pathophysiological conditions, but little is known about the molecular mechanisms regulating the expression of OAT1. In the present study, we investigated the transcriptional regulation of OAT1 and found that hepatocyte nuclear factor (HNF)-4α markedly transactivated the OAT1 promoter. A deletion analysis of the OAT1 promoter suggested that the regions spanning −1191 to −700 base pairs (bp) and −140 to −79 bp were essential for the transactivation by HNF-4α. These regions contained a direct repeat separated by two nucleotides (DR-2), which is one of the consensus sequences binding to HNF-4α, and an inverted repeat separated by eight nucleotides (IR-8), which was recently identified as a novel element for HNF-4α, respectively. An electrophoretic mobility shift assay showed that HNF-4α bound to DR-2 and IR-8 under the conditions of HNF-4α overexpression. Furthermore, under normal conditions, HNF-4α bound to IR-8, and a mutation in IR-8 markedly reduced the OAT1 promoter activity, indicating that HNF-4α regulates the basal transcription of OAT1 via IR-8. This paper reports the first characterization of the human OAT1 promoter and the first gene in the kidney whose promoter activity is regulated by HNF-4α.
Renal vascular and tubulointerstitial inflammation and proliferation in Cyp1a1-Ren2 transgenic rats with inducible ANG II-dependent malignant hypertension
Authors: Graciano Miguel L. , Mouton Cynthia R. , Patterson Matthew E. , Seth Dale M. , Mullins John J. , Mitchell Kenneth D.
Published: March 2007

Transgenic rats with inducible ANG II-dependent malignant hypertension [TGR(Cyp1a1Ren2)] were generated by inserting the mouse Ren2 renin gene into the genome of the rat. The present study was performed to assess renal morphological changes occurring during the development of ANG II-dependent malignant hypertension in these rats. Male Cyp1a1-Ren2 rats ( n = 10) were fed normal rat food containing indole-3-carbinol (I3C; 0.3%) for 10 days to induce malignant hypertension. Rats induced with I3C had higher mean arterial pressures (173 ± 9 vs. 112 ± 11 mmHg, P < 0.01) than noninduced normotensive rats ( n = 9). Glomerular damage was evaluated by determination of the glomerulosclerosis index (GSI) in tissue sections stained with periodic acid-Schiff. Kidneys of hypertensive rats had a higher GSI than normotensive rats (21.3 ± 5.6 vs. 3.5 ± 1.31 units). Quantitative analysis of macrophage ED-1-positive cells and proliferating cell nuclear antigen using immunohistochemistry demonstrated increased macrophage numbers in the renal interstitium (106.4 ± 11.4 vs. 58.7 ± 5.0 cells/mm2) and increased proliferating cell number in cortical tubules (37.8 ± 5.7 vs. 24.2 ± 2.1 cells/mm2), renal cortical vessels (2.2 ± 0.5 vs. 0.13 ± 0.07 cells/vessel), and the cortical interstitium (33.6 ± 5.7 vs. 4.2 ± 1.4 cells/mm2) of hypertensive rat kidneys. These findings demonstrate that the renal pathological changes that occur during the development of malignant hypertension in Cyp1a1-Ren2 rats are characterized by inflammation and cellular proliferation in cortical vessels and tubulointerstitium.
Cortical Involvement in the Generation of Essential Tremor
Authors: Raethjen Jan , Govindan R. B. , Kopper Florian , Muthuraman M. , Deuschl Günther
Published: March 2007

Conflicting results on the existence of tremor-related cortical activity in essential tremor (ET) have raised questions on the role of the cortex in tremor generation. Here we attempt to address these issues. We recorded 64 channel surface EEGs and EMGs from forearm muscles in 15 patients with definite ET. EEG and EMG power spectra, relative power of the rhythmic EMG activity, relative EEG power at the tremor frequency, and EEG–EMG and EEG–EEG coherence were calculated and their dynamics over time explored. Corticomuscular delay was studied using a new method for narrow-band coherent signals. Corticomuscular coherence in the contralateral central region at the tremor frequency was present in all patients in recordings with a relative tremor EMG power exceeding a certain level. However, the coherence was lost intermittently even with tremors far above this level. Physiological 15- to 30-Hz coherence was found consistently in 11 patients with significantly weaker EMG activity in this frequency range. A more frontal (mesial) hot spot was also intermittently coupled with the tremor and the central hot spot in five patients. Corticomuscular delays were compatible with transmission in fast corticospinal pathways and feedback of the tremor signal. Thus the tremor rhythm is intermittently relayed only in different cortical motor areas. We hypothesize that tremor oscillations build up in different subcortical and subcortico-cortical circuits only temporarily entraining each other.
Eye Position Compensation Improves Estimates of Response Magnitude and Receptive Field Geometry in Alert Monkeys
Authors: Tang Yamei , Saul Alan , Gur Moshe , Goei Stephanie , Wong Elsie , Ersoy Bilgin , Snodderly D. Max
Published: March 2007

Studies of visual function in behaving subjects require that stimuli be positioned reliably on the retina in the presence of eye movements. Fixational eye movements scatter stimuli about the retina, inflating estimates of receptive field dimensions, reducing estimates of peak responses, and blurring maps of receptive field subregions. Scleral search coils are frequently used to measure eye position, but their utility for correcting the effects of fixational eye movements on receptive field maps has been questioned. Using eye coils sutured to the sclera and preamplifiers configured to minimize cable artifacts, we reexamined this issue in two rhesus monkeys. During repeated fixation trials, the eye position signal was used to adjust the stimulus position, compensating for eye movements and correcting the stimulus position to place it at the desired location on the retina. Estimates of response magnitudes and receptive field characteristics in V1 and in LGN were obtained in both compensated and uncompensated conditions. Receptive fields were narrower, with steeper borders, and response amplitudes were higher when eye movement compensation was used. In sum, compensating for eye movements facilitated more precise definition of the receptive field. We also monitored horizontal vergence over long sequences of fixation trials and found the variability to be low, as expected for this precise behavior. Our results imply that eye coil signals can be highly accurate and useful for optimizing visual physiology when rigorous precautions are observed.
Electroacupuncture suppresses myostatin gene expression: cell proliferative reaction in mouse skeletal muscle
Authors: Takaoka Yutaka , Ohta Mika , Ito Akihiko , Takamatsu Kunihiko , Sugano Aki , Funakoshi Kotaro , Takaoka Nobuo , Sato Nobuko , Yokozaki Hiroshi , Arizono Naoki , Goto Shuji , Maeda Eiichi
Published: March 2007

Complementary and alternative medicine (CAM) may provide patients with an alternative to traditional medicine, but an assessment of its efficacy is required. One CAM method, electroacupuncture (EA) treatment, is a maneuver that utilizes stimulation of acupuncture needles with a low-frequency microcurrent. To study the effect of short-term EA, we evaluated the differential expression of genes induced by EA in mouse skeletal muscle for up to 24 h. We then used RT-PCR to confirm the expression patterns of six differentially expressed genes. Bioinformatics analysis of their transcription control regions showed that EA-inducible genes have numerous common binding motifs that are related to cell differentiation, cell proliferation, muscle repair, and hyperplasia. These results suggested that EA treatment may induce cell proliferation in skeletal muscle. To verify this possibility, we used EA to stimulate mouse skeletal muscle daily for up to 1 mo and examined the long-term effects. Immunohistochemical analysis showed that nuclei of muscle cells treated with EA for 1 mo, especially nuclei of satellite cells, reacted with anti-human PCNA. Also, expression of the gene encoding myostatin, which is a growth repressor in muscle satellite cells, was suppressed by daily EA treatment for 1 wk; EA treatment for 1 mo resulted in more marked suppression of the gene. These molecular findings constitute strong evidence that EA treatment suppresses myostatin expression, which leads to a satellite cell-related proliferative reaction and repair in skeletal muscle.
Feeding a Protective Hydrolysed Casein Diet to Young Diabetes‐prone BB Rats Affects Oxidationof L[U − C14]glutamine in Islets and Peyer′sPatches, Reduces Abnormally High Mitotic Activityin Mesenteric Lymph Nodes, Enhances Islet Insulinand Tends to Normalize NO Production
Authors: Malaisse Willy J. , Olivares Elizabeth , Laghmich Aouatif , Ladrière Laurence , Sener Abdullah , Scott Fraser W.
Published: March 2007

The present studies were undertaken to examine
concomitant diet‐induced changes in pancreatic
islets and cells of the gut immune system of
diabetes‐prone BB rats in the period before classic
insulitis. Diabetes‐prone (BBdp) and control non‐diabetes
prone (BBc) BB rats were fed for ~ 17 days
either a mainly plant‐based standard laboratory
rodent diet associated with high diabetes frequency,
NIH‐07 (NIH) or a protective semipurified diet with
hydrolyzed casein (HC) as the amino acid source. By
about 7 weeks of age, NIH‐fed BBdp rats had lower
plasma insulin and insulin/glucose ratio, lower
insulin content of isolated islets, lower basal levels
of NO but higher responsiveness of NO production
to IL‐1β in cultured islets, and higher Con A
response and biosynthetic activities in mesenteric
lymphocytes than control rats fed the same diet. In
control rats, the HC diet caused only minor changes
in most variables, except for a decrease in oxidation
of L‐[U − C14]glutamine in Peyer′s patch (PP) cells and
an increase in protein biosynthesis in mesenteric
lymphocytes. In BBdp rats, however, the HC diet increased plasma insulin concentration, islet insulin/
protein ratio, and tended to normalize the basal
and IL‐1β‐stimulated NO production by cultured
islets. The HC diet decreased oxidation of L‐[U − C14]glutamine in BBdp pancreatic islets, whereas
oxidation of L‐[U − C14]glutamine in PP cells was
increased, and the basal [Methyl‐H3] thymidine
incorporation in mesenteric lymphocytes was decreased.
These findings are compatible with the
view that alteration of nutrient catabolism in islet
cells as well as key cells of the gut immune system,
particularly changes in mitotic and biosynthetic
activities in mesenteric lymphocytes, as well as
basal and IL‐1β stimulated NO production, participate
in the sequence of events leading to autoimmune
diabetes in BB rats. Thus, the protection afforded by feeding a hydrolysed casein‐based diet
derives from alterations in both the target islet tissue
and key cells of the gut immune system in this
animal model of type 1 diabetes.
Slowing of Motor Nerve Conduction Velocity in Streptozotocin‐induced Diabetic Rats is Preceded by Impaired Vasodilation in Arterioles that Overlie the Sciatic Nerve
Authors: Coppey Lawrence J. , Davidson Eric P. , Dunlap Joyce A. , Lund Donald D. , Yorek Mark A.
Published: March 2007

Diabetes mellitus produces marked abnormalities in motor nerve conduction, but the mechanism is not clear. In the present study we hypothesized that in the streptozotocin (STZ)‐induced diabetic rat impaired vasodilator function in arterioles that provide circulation to the region of the sciatic nerve is associated with reduced endoneural blood flow (EBF) and that these defects precede slowing of
motor nerve conduction velocity, and thereby may contribute to nerve dysfunction. As early as three days after the induction of diabetes endoneural blood flow was reduced in the STZ‐induced diabetic
rat. Furthermore, after 1 week of diabetes acetylcholine‐induced vasodilation was found to be impaired. This was accompanied by an increase in the superoxide level in arterioles that provide circulation to
the region of the sciatic nerve as well as changes in the level of other markers of oxidative stress including an increase in serum levels of thiobarbituric acid reactive substances and a decrease in lens
glutathione level. In contrast to the vascular related changes that occur within 1 week of diabetes, motor nerve conduction velocity and sciatic nerve Na+/k+ ATPase activity were significantly reduced following 2 and 4 weeks of diabetes, respectively. These studies demonstrate that changes in vascular function in the STZ‐induced diabetic rat precede the slowing of motor nerve conduction velocity (MNCV) and are accompanied by an increase in superoxide levels in arterioles that provide circulation to the region of the sciatic nerve.
Characterization of Obesity Phenotypesin Psammomys Obesus (Israeli Sand Rats)
Authors: Walder Ken R. , Fahey Richard P. , Morton Greg J. , Zimmet Paul Z. , Collier Greg R.
Published: March 2007

Psammomys obesus (the Israeli sand rat) has been
well studied as an animal model of Type 2 diabetes.
However, obesity phenotypes in these animals have
not been fully characterized. We analyzed phenotypic
data including body weight, percentage body
fat, blood glucose and plasma insulin concentration
for over 600 animals from the Psammomys obesus
colony at Deakin University to investigate the
relationships between body fat, body weight and
Type 2 diabetes using regression analysis and
general linear modelling. The body weight distribution
in Psammomys obesus approximates a normal
distribution and closely resembles that observed in
human populations. Animals above the 75th percentile
for body weight had increased body fat
content and a greater risk of developing diabetes.
Increased visceral fat content .was also associated
with elevated blood glucose and plasma insulin
concentrations in these animals. A familial effect
was also demonstrated in Psammomys obesus, and
accounted for 51% of the variation in body weight,
and 23–26% of the variation in blood glucose and
plasma insulin concentrations in these animals.
Psammomys obesus represents an excellent animal
model of.obesity and Type 2 diabetes that exhibits a
phenotypic pattern closely resembling that observed
in human population studies. The obesity described
in these animals was familial in nature and was
significantly associated with Type 2 diabetes.
Correlation Between Pancreatic Islet Uncoupling Protein‐2 (UCP2) mRNA Concentration And Insulin Status in Rats
Authors: Kassis Nadim , Bernard Catherine , Pusterla Aristide , Casteilla Louis , Pétnicaud Luc , Richard Denis , Ricquier Daniel , Ktorza Alain
Published: March 2007

Hypothesizing that UCP2 may influence insulin
secretion by modifying the ATP/ADP ratio within
pancreatic islets, we have investigated the expression
of intraislet UCP2 gene in rats showing insulin
oversecretion (non‐diabetic Zucker fa/fa obese rats,
glucose‐infused Wistar rats) or insulin undersecretion
(fasting and mildly diabetic rats). We found that
in Zucker fa/fa obese rats, hyperinsulinemia
(1222 ± 98 pmol/1 vs. 128 ± 22 pmol/1 in lean Zucker
rats) was accompanied by a significant increase in
UCP2 mRNA levels. In rat submitted to a 5 day
infusion with glucose, hyperinsulinemia (1126 ± 101
pmol/l vs. 215 ± 25 pmol/1 in Wistar control rats),
coincided with an enhanced intraislet UCP2 gene
expression, whereas a 8h or a 2 day‐infusion did not
induce significant changes in UCP2 mRNA expression.
In rats made hypoinsulinemic and mildly
diabetic by the injection of a low dose of streptozotocin,
and in 4‐day‐fasting rats (plasma insulin
28 ± 5 pmol/1) UCP2 gene expression was sharply
decreased. A 3‐day‐fast was ineffective. The data
show the existence of a time‐dependent correlation
between islet mRNA UCP2 and insulin that may be
interpreted as an adaptative response to prolonged
insulin excess.
Glomerular Basement Membrane Selective Permeability in Short‐term Streptozotocin‐induced Diabetic Rats
Authors: Doucet Michele , Londoño Irene , Gómez-Pascual Amparo , Bendayan Moise
Published: March 2007

In diabetes, the glomerular basement membrane
undergoes thickening and structural alterations with
loss of glomerular permselectivity properties. However,
the onset of the alterations at early phases of
diabetes is unclear. Aiming to determine the functional
and structural alterations of the glomerular
wall in the early stages of diabetes, we have studied
the distribution of endogenous circulating albumin
and type IV collagen in the glomerular basement
membrane, using the immunocytochemical approach.
The streptozotocin‐injected hyperglycemic
rat was our animal model. Renal tissues were
examined after 10 days, 2, 4 and 6 months of hyperglycemia.
Upon immunogold labelings, changes in
the glomerular permeability to endogenous albumin
were found altered as early as upon ten days of
hyperglycemia. In contrast, no structural modifications
were detected at this time point. Indeed,
glomerular basement membrane thickening and an
altered type IV collagen labeling distribution were
only observed after four months of hyperglycemia,
suggesting that functional alterations take place
early in diabetes prior to any structural modification.
In order to evaluate the reversibility of the
glomerular alterations, two‐month‐old diabetic animals
were treated with insulin. These animals
showed a significant restoring of their glomerular
permselectivity. Our results suggest a link between
glycemic levels and alteration of glomerular permeability
in early stages of diabetes, probably through
high levels of glycated serum proteins.
A Thiazolidinedione Improves In Vivo Insulin Action on Skeletal Muscle Glycogen Synthase in Insulin‐Resistant Monkeys
Authors: Ortmeyer Heidi K. , Bodkin Noni L. , Haney Joseph , Yoshioka Shinji , Horikoshi Hiroyoshi , Hansen Barbara C.
Published: March 2007

Thiazolidinediones (TZD) have been shown to have
anti‐diabetic effects including the ability to decrease
fasting hyperglycemia and hyperinsulinemia, increase
insulin‐mediated glucose disposal rate (M)
and decrease hepatic glucose production, but the
mechanisms of action are not well established. To
determine whether a TZD (R‐102380, Sankyo Company
Ltd., Tokyo, Japan) could improve insulin
action on skeletal muscle glycogen synthase (GS),
the rate‐limiting enzyme in glycogen synthesis, 4
insulin‐resistant obese monkeys were given I mg/kg/
day R‐102380 p.o. for a 6‐week period. Skeletal
muscle GS activity and glucose 6‐phosphate (G6P)
content were compared between pre‐dosing and
dosing periods before and during the maximal
insulin‐stimulation of a euglycemic hyperinsulinemic
clamp.Compared to pre‐dosing, insulin‐stimulated GS
activity and G6P content were increased by this
TZD: GS independent activity (p = 0.02), GS total
activity (p = 0.005), GS fractional activity (p = 0.06)
and G6P content (p = 0.02). The change in GS
activity induced by in vivo insulin (insulin‐stimulated
minus basal) was also increased by this TZD:
GS independent activity (p = 0.03) and GS fractional
activity (p = 0.04).We conclude that the TZD R‐102380 improves
insulin action at the skeletal muscle in part by
increasing the activity of glycogen synthase. This
improvement in insulin sensitivity may be a key
factor in the anti‐diabetic effect of the thiazolidinedione
class of agents.
Therapeutic Differentiation of Tumor‐derived Insulin‐producing Cells Selected for Resistance to Diabetogenic Drugs
Authors: Bloch Konstantin , Vardi Pnina
Published: March 2007

Differentiation therapy has been proposed as a new approach to selectively engage the process of tumor cell differentiation during chemotherapy of cancer. Our recent in vitro study suggests that such an approach can be extended and utilized for the selection of tumor‐derived insulin‐producing cells for transplantation. Repeated treatment with streptozotocin selected toxin resistant subpopulation of insulin producing tumor RINmS cells, characterized increased level of insulin content and secretion. In the present study RINmS cells were found to have higher glucose sensitivity and insulin response compared with parental RINm cells. In addition, compounds known to induce elevated level of cAMP beta‐cells, such as isobutyl methyl xanthine, and forskolin, potentiated glucose‐induced insulin secretion of RINmS, but had no effect on the naive parental RINm cells. These experiments suggest that differentiation therapy can be utilized for engineering insulin producing cells with improved defense and secretory mechanisms.
Lack of Expression of Gp‐130 Makes Pancreatic Beta Cell Lines Unresponsive to the IL‐6 Family of Cytokines
Authors: Naselli Gaetano , Deaizpurua Henry J. , Thomas Helen E. , Johnston Anne M. , Kay Thomas W. H.
Published: March 2007

Cytokine receptors from the IL‐6 receptor family are comprised of ligand specific α chains and a common signalling chain, gp‐130, which is also required for high affinity binding. A cDNA library generated from the β‐TC3 SV40 T‐antigen transformed insulinoma cell line was screened for members of this receptor family potentially relevant to both beta cell development and autoimmunity. Degenerate oligonucleotide primers to a consensus region of these receptors were used and the IL‐11 receptor (α chain was identified. Despite confirmation of IL‐11 receptor mRNA expression, iodinated bioactive IL‐11 did not bind specifically to β‐TC3 cells and gp‐130‐dependent cytokines did not elicit signalling events in beta cell lines. This was explained by absence of gp‐130 protein or mRNA in the beta cell lines tested and in primary islets. We conclude from these resuits that the previously recognised effects of IL‐6 family member cytokines on pancreatic islets must be indirect via other non‐beta cells within the islet, rather than due to direct effects on beta cells themselves.
Genetic Mapping and Functional Studies of a Natural Inhibitor of the Insulin Receptor Tyrosine Kinase: The Mouse Ortholog of Human α2‐HS Glycoprotein
Authors: Cintrón Vivian J. , Ko Minoru S. H. , Chi Kenneth D. , Gross Jason P. , Srinivas Pothur R. , Goustin Anton Scott , Grunberger George
Published: March 2007

Fetuin/α2‐HS glycoprotein (α2‐HSG) homologs have been identified in several species including rat, sheep, pig, rabbit, guinea pig, cattle, mouse and human. Multiple physiological roles for these homologs have been suggested, including ability to bind to hydroxyapatite crystals and to specifically inhibit the tyrosine kinase (TK) activity of the insulin receptor (IR). In this study we report the identification, cloning, and characterization of the mouse Ahsg gene and its function as an IR‐TK inhibitor. Genomic clones derived from a mouse Svj 129 genomic library were sequenced in order to characterize the intron–exon organization of the mouse Ahsg gene, including an 875 bp subclone containing 154 bp upstream from the transcription start site, the first exon, and part of the first intron. A second genomic subclone harboring a 3.45 kb Bgl II fragment contained exons 2, 3 and 4 in addition to two adjacent elements within the first intron‐a repetitive element of the B1 family (92 bp) and a 271 bp tract of (T,C)n * (A,G)n. We have mapped mouse Ahsg at 16 cM adjacent to the Diacylglycerol kinase 3 (Dagk3) gene on chromosome 16 by genotyping interspecific backcross panels between C57BL/6J and Mus spretus. The position is syntenic with human chromosome 3q27, where the human AHSG gene resides. Using recombinant mouse α2‐HSG expressed from a recombinant baculovirus,
we demonstrate that mouse α2‐HSG inhibits insulin–stimulated IR autophosphorylation and
IR‐TKA in vitro. In addition, mouse α2‐HSG (25μg/ml) completely abolishes insulin‐induced
DNA synthesis in H‐35 rat hepatoma cells. Based on
the sequence data and functional analysis, we conclude
that the mouse Ahsg gene is the true ortholog
of the human AHSG gene.
Modulation of β‐Cell Ouabain‐Sensitive  86Rb+ Influx(Na+/k+ Pump) by D‐Glucose, Glibenclamideor Diazoxide
Authors: Elmi Adrian , Idahl Lars-ÅKe , Sehlin Janove
Published: March 2007

The activity of the β‐cell Na+/k+ pump was studied
by using ouabain‐sensitive (lmM ouabain)  86Rb+
influx in β‐cell‐rich islets of Umeå‐ob/ob mice as an
indicator of the pump function. The present results
show that the stimulatory effect of glucose on
ouabain‐sensitive  86Rb+ influx reached its approximate
maximum at 5mM glucose. Pre‐treatment of
the islets with 20mM glucose for 60 min strongly
reduced the glucose‐induced stimulation of the Na+/k+ pump. Pre‐treatment (60 or 180 min) of islets at
0mM glucose, on the other hand, did not affect the
magnitude of the glucose‐induced stimulation of  86Rb+ influx dunng the subsequent 5‐min incubation.
Glibenclamide stimulated the ouabain‐sensitive
 86Rb+ uptake in the same manner as glucose.
The stimulatory effect, showed its apparent maximum
at 0.5μM. Pre‐treatment (60 min) of islets with
1μM glibenclamide did not reduce the subsequent
stimulation of the ouabain‐sensitive  86Rb+ influx.
The stimulatory effect of glibenclamide and D‐glucose
were not .additive, suggesting that they
may have the same mechanism of action. No direct
effect of glibenclamide (0.01‐1μM) was observed
on the Na+/k+ ATPase activity in homogenates of
islets. Diazoxide (0.4mM) inhibited the Na+/k+
pump. This effect was sustained even after 60 min of
pre‐treatment of islets with 0.4mM diazoxide. The
stimulatory effect of glibenclamide and D‐glucose
were abolished by diazoxide. It is concluded
that nutrient as well as non‐nutrient insulin secretagogues activate the Na+/k+ pump, probably
as part of the membrane repolarisation process.
Evidence for Mechanistic Alterations of Ca2+Homeostasis in Type 2 Diabetes Mellitus
Authors: Balasubramanyam Muthuswamy , Balaji Ramalingham A. , Subashini Balakrishnan , Mohan Viswanathan
Published: March 2007

Altered cytosolic Ca2+ is implicated in the aetiology
of many diseases including diabetes but there are
few studies on the mechanism(s) of the altered Ca2+
regulation. Using human lymphocytes, we studied
cytosolic calcium (Cai) and various Ca2+ transport
mechanisms in subjects with Type 2 diabetes
mellitus and control subjects. Ca2+‐specific fluorescent
probes (Fura‐2 and Fluo‐3) were used to
monitor the Ca2+ signals. Thapsigargin, a potent and
specific inhibitor of the sarco(endo)plasmic reticulum
Ca2+‐ATPase (SERCA), was used to study Ca2+‐
store dependent Ca2+ fluxes. Significant (P < 0.05)
elevation of basal Cai levels was observed in
lymphocytes from diabetic subjects. Cai levels were
positively correlated with fasting, plasma glucose
and HbAlc. There was also a significant (P < 0.05)
reduction in plasma membrane calcium (PMCA)
ATPase activity in diabetic subjects compared to
controls. Cells from Type 2 diabetics exhibited an
increased Ca2+ influx (as measured both by Fluo‐3
fliorescence and  45Ca assays) as a consequence of
of thapsigargin‐mediated Ca2+ store depletion. Upon
addition of Mn2+ (a surrogate of Ca2+), the fura‐2
fluorescence decayed in an exponential fashion and
the rate and extent of this decline was steeper and
greater in cells from type 2 diabetic patients. There
was also a significant (P < 0.05) difference in the
Na+/Ca2+ exchange activity in Type 2 diabetic
patients, both under resting conditions and after challenging the cells with thapsigargin, when the
internal store Ca2+ sequestration was circumvented.
Pharmacological activation of protein kinase C
(PKC) in cells from patients resulted in only partial
inhibition of Ca2+ entry. We conclude that cellular
Ca2+ accumulation in cells from Type 2 diabetes
results from (a) reduction in PMCA ATPase activity,
(b) modulation of Na+/Ca2+ exchange and (3)
increased Ca2+ influx across the plasma membrane.
Defective Morphogenesis and Functional Maturation in Fetal Islet‐Like Cell Clusters From OLETF Rat, A Model of NIDDM
Authors: Zhu Min , Mizuno Akira , Noma Yoshihiko , Murakami Takashi , Kuwajima Masamichi , Shima Kenji , Lan Michael S.
Published: March 2007

A failure in the compensate proliferation of pancreatic β‐cells, as the primary pathogenic event, has been reported in OLETF rat, a model of NIDDM. The aim of the present study is to define whether the β‐cell defect is attributed to the fetal stage islet development, if so, whether the defect involves down regulation of PDX‐1 protein expression. Morphological changes, β‐cell function, and the expression of PDX‐1 protein were examined in the cultured fetal islet‐like cell clusters (ICCs) from OLETF rats along with their diabetes‐resistant control counterpart LETO rats in the presence of 5.5 or 11.1mM glucose for 48, 72, 96, and 120‐hr, respectively. We have observed four abnormalities in the ICCs of OLETF rats. First, a defective morphogenesis was noted during the 72 to 120‐hr ICC culture, a period characterized by a dramatic increase in both β‐cell and non‐β‐cell (α,σ, and PP) populations in control rats. This defective morphogenesis was demonstrated by a growth retardation of epithelial stratification and poor development of both β‐cell and non‐β‐cell masses along with a parallel decline in relevant islet hormone contents. Second, a functional defect was characterized by failure to response to glucose during the 96 to 120‐ hr‐cultured ICCs. Third, the ultrastructural analysis revealed a significant reduction in the number of secretory granules. Four, Western blot analysis showed a significant decrease of PDX‐1 protein expression in the OLETF ICCs cultured in 11.1mM glucose for 48 to 72‐hr and in 5.5mM glucose for 120‐hr. Therefore, we concluded that during the fetal stage of islet development, OLETF rats exhibit both morphological and functional defects.