bluuebunny/crossref_metadata_2025 huggingface dataset:
Affinity for MgADP and force of unbinding from actin of myosin purified from tonic and phasic smooth muscle
Authors: Léguillette Renaud , Zitouni Nedjma B. , Govindaraju Karuthapillai , Fong Laura M. , Lauzon Anne-Marie
Published: July 2008

Smooth muscle is unique in its ability to maintain force at low MgATP consumption. This property, called the latch state, is more prominent in tonic than phasic smooth muscle. Studies performed at the muscle strip level have suggested that myosin from tonic muscle has a greater affinity for MgADP and therefore remains attached to actin longer than myosin from phasic muscle, allowing for cross-bridge dephosphorylation and latch-bridge formation. An alternative hypothesis is that after dephosphorylation, myosin reattaches to actin and maintains force. We investigated these fundamental properties of smooth muscle at the molecular level. We used an in vitro motility assay to measure actin filament velocity (νmax) when propelled by myosin purified from phasic or tonic muscle at increasing [MgADP]. Myosin was 25% thiophosphorylated and 75% unphosphorylated to approximate in vivo conditions. The slope of νmax versus [MgADP] was significantly greater for tonic (−0.51 ± 0.04) than phasic muscle myosin (−0.15 ± 0.04), demonstrating the greater MgADP affinity of myosin from tonic muscle. We then used a laser trap assay to measure the unbinding force from actin of populations of unphosphorylated tonic and phasic muscle myosin. Both myosin types attached to actin, and their unbinding force (0.092 ± 0.022 pN for phasic muscle and 0.084 ± 0.017 pN for tonic muscle) was not statistically different. We conclude that the greater affinity for MgADP of tonic muscle myosin and the reattachment of dephosphorylated myosin to actin may both contribute to the latch state.
Dietary sodium manipulation during critical periods in development sensitize adult offspring to amphetamines
Authors: McBride Shawna M. , Culver Bruce , Flynn Francis W.
Published: July 2008

This study examined critical periods in development to determine when offspring were most susceptible to dietary sodium manipulation leading to amphetamine sensitization. Wistar dams ( n = 6–8/group) were fed chow containing low (0.12% NaCl; LN), normal (1% NaCl; NN), or high sodium (4% NaCl; HN) during the prenatal or early postnatal period (birth to 5 wk). Offspring were fed normal chow thereafter until testing at 6 mo. Body weight (BW), blood pressure (BP), fluid intake, salt preference, response to amphetamine, open field behavior, plasma adrenocorticotropin hormone (ACTH), plasma corticosterone (Cort), and adrenal gland weight were measured. BW was similar for all offspring. Offspring from the prenatal and postnatal HN group had increased BP, NaCl intake, and salt preference and decreased water intake relative to NN offspring. Prenatal HN offspring had greater BP than postnatal HN offspring. In response to amphetamine, both prenatal and postnatal LN and HN offspring had increased locomotor behavior compared with NN offspring. In a novel open field environment, locomotion was also increased in prenatal and postnatal LN and HN offspring compared with NN offspring. ACTH and Cort levels 30 min after restraint stress and adrenal gland weight measurement were greater in LN and HN offspring compared with NN offspring. These results indicate that early life experience with low- and high-sodium diets, during the prenatal or early postnatal period, is a stress that produces long-term changes in responsiveness to amphetamines and to subsequent stressors.
Connexin mimetic peptides fail to inhibit vascular conducted calcium responses in renal arterioles
Authors: Sorensen Charlotte Mehlin , Salomonsson Max , Braunstein Thomas Hartig , Nielsen Morten Schak , Holstein-Rathlou Niels-Henrik
Published: July 2008

Vascular conducted responses are believed to play a central role in controlling the microcirculatory blood flow. The responses most likely spread through gap junctions in the vascular wall. At present, four different connexins (Cx) have been detected in the renal vasculature, but their role in transmission of conducted vasoconstrictor signals in the preglomerular arterioles is unknown. Connexin mimetic peptides were previously reported to target and inhibit specific connexins. We, therefore, investigated whether conducted vasoconstriction in isolated renal arterioles could be blocked by the use of mimetic peptides directed against one or more connexins. Preglomerular resistance vessels were microdissected from kidneys of Sprague-Dawley rats and loaded with fura 2. The vessels were stimulated locally by applying electrical current through a micropipette, and the conducted calcium response was measured 500 μm from the site of stimulation. Application of connexin mimetic peptides directed against Cx40, 37/43, 45, or a cocktail with equimolar amounts of each, did not inhibit the propagated response, whereas the nonselective gap junction uncoupler carbenoxolone completely abolished the propagated response. However, the connexin mimetic peptides were able to reduce dye coupling between rat aorta endothelial cells shown to express primarily Cx40. In conclusion, we did not observe any attenuating effects on conducted calcium responses in isolated rat interlobular arteries when exposed to connexin mimetic peptides directed against Cx40, 37/43, or 45. Further studies are needed to determine whether conducted vasoconstriction is mediated via previously undescribed pathways.
G418-mediated ribosomal read-through of a nonsense mutation causing autosomal recessive proximal renal tubular acidosis
Authors: Azimov Rustam , Abuladze Natalia , Sassani Pakan , Newman Debra , Kao Liyo , Liu Weixin , Orozco Nicholas , Ruchala Piotr , Pushkin Alexander , Kurtz Ira
Published: July 2008

Autosomal recessive proximal renal tubular acidosis is caused by mutations in the SLC4A4 gene encoding the electrogenic sodium bicarbonate cotransporter NBCe1-A. The mutations that have been characterized thus far result in premature truncation, mistargeting, or decreased function of the cotransporter. Despite bicarbonate treatment to correct the metabolic acidosis, extrarenal manifestations persist, including glaucoma, cataracts, corneal opacification, and mental retardation. Currently, there are no known therapeutic approaches that can specifically target mutant NBCe1-A proteins. In the present study, we tested the hypothesis that the NBCe1-A-Q29X mutation can be rescued in vitro by treatment with aminoglycoside antibiotics, which are known for their ability to suppress premature stop codons. As a model system, we cloned the NBCe1-A-Q29X mutant into a vector lacking an aminoglycoside resistance gene and transfected the mutant cotransporter in HEK293-H cells. Cells transfected with the NBCe1-A-Q29X mutant failed to express the cotransporter because of the premature stop codon. Treatment of the cells with G418 significantly increased the expression of the full-length cotransporter, as assessed by immunoblot analysis. Furthermore, immunocytochemical studies demonstrated that G418 treatment induced cotransporter expression on the plasma membrane whereas in the absence of G418, NBCe1-A-Q29X was not expressed. In HEK293-H cells transfected with the NBCe1-A-Q29X mutant not treated with G418, NBCe1-A-mediated flux was not detectable. In contrast, in cells transfected with the NBCe1-A-Q29X mutant, G418 treatment induced Na+- and HCO3−-dependent transport that did not differ from wild-type NBCe1-A function. G418 treatment in mock-transfected cells was without effect. In conclusion, G418 induces ribosomal read-through of the NBCe1-A-Q29X mutation in HEK293-H cells. These findings represent the first evidence that in the presence of the NBCe1-A-Q29X mutation that causes proximal renal tubular acidosis, full-length functional NBCe1-A protein can be produced. Our results provide the first demonstration of a mutation in NBCe1-A that has been treated in a targeted and specific manner.
Expression profiling of hepatic genes associated with lipid metabolism in nephrotic rats
Authors: Zhou Yunfeng , Zhang Xiaoyan , Chen Lihong , Wu Jing , Dang Huaixin , Wei Mingfen , Fan Yanbo , Zhang Yahua , Zhu Yi , Wang Nanping , Breyer Matthew D. , Guan Youfei
Published: July 2008

Hyperlipidemia is one of the major features of nephrotic syndrome (NS). Although many factors have been implicated in the pathogenesis of NS-related dyslipidemia, the underlying mechanisms remain largely uncharacterized. The present study was designed to examine the gene profile associated with lipid metabolism in the livers of nephrotic rats. NS was created in male Sprague-Dawley rats ( n = 6) receiving sequential intraperitoneal injections of puromycin aminonucleoside. Analysis by Affymetrix assay, quantitative RT-PCR, and Northern and Western blotting revealed 21 genes associated with cholesterol and fatty acid metabolism. Eight genes involved in cholesterol metabolism, Apo A-I, Acly, Acat, Mpd, Fdps, Ss, Lss, and Nsdhl, were significantly upregulated under NS. Four genes involved in fatty acid biosynthesis, Acc, FAS, ELOVL 2, and ELOVL6, and three critical for triglyceride biosynthesis, Gpam, Agpat 3, and Dgat 1, were significantly upregulated, whereas two genes involved in fatty acid oxidation, Dci and MCAD, were downregulated. Expression of several genes in sterol-regulatory element-binding protein (SREBP)-1 activation was also aberrantly altered in nephrotic livers. The expression and transcriptional activity of SREBP-1 but not SREBP-2 were increased in nephrotic rats as assessed by real-time PCR, immunoblotting, and gel shift assays. The upregulation of hepatic genes involved in cholesterol biosynthesis may play an important role in the pathogenesis of hypercholesterolemia, whereas upregulation of genes participating in hepatic fatty acid and triglyceride biosynthesis and downregulation of genes involved in hepatic fatty acid oxidation may contribute to hypertriglyceridemia in nephrotic rats. Activation of SREBP-1 transcription factor may represent an underlying molecular mechanism of hyperlipidemia in NS.
Characterization of the Hoechst 33342 side population from normal and malignant human renal epithelial cells
Authors: Addla Sanjai K. , Brown Mick D. , Hart Claire A. , Ramani Vijay A. C. , Clarke Noel W.
Published: July 2008

The fundamental changes which predispose for renal cell carcinoma (RCC) are poorly characterized. It is hypothesized that “cancer stem cells” may be influential in carcinogenesis, and the epithelial side population (SP) is enriched for stemlike cells in other epithelial cancers. In this study, we have isolated and characterized the SP and non-SP (NSP) populations from normal (NK) and malignant (RCC) human kidney tissue. NK specimens were taken from patients undergoing non-renal cancer surgery and paired malignant and macroscopically normal tissue samples were taken from patients undergoing surgery for RCC. The Hoechst 33342 dye efflux technique was used to isolate epithelial SP and NSP from normal and malignant human renal tissue. Cellular subpopulations were phenotyped for lineage, cell cycle, and putative stem cell markers, and functionally characterized using in vitro colony-forming and proliferation assays. The SP constituted 3.8 ± 0.4 and 5.9 ± 0.9% of epithelial cells in NK and RCC, respectively, of which 14.1 ± 3.5 and 13.2 ± 3.6% were shown to be in G0. SP cells demonstrated greater proliferative potential in colony-forming efficiency, long-term culture, and spheroids assays and were shown to be maintained upon tissue culture passage. We have shown that the renal SP is enriched for quiescent cells, with a high proliferative capacity and stemlike properties. The population is, however, heterogeneous, confirming that the terms “SP cell” and “stem cell” cannot be used interchangeably.
Arterial-ventricular coupling: mechanistic insights into cardiovascular performance at rest and during exercise
Authors: Chantler Paul D. , Lakatta Edward G. , Najjar Samer S.
Published: July 2008

Understanding the performance of the left ventricle (LV) requires not only examining the properties of the LV itself, but also investigating the modulating effects of the arterial system on left ventricular performance. The interaction of the LV with the arterial system, termed arterial-ventricular coupling (EA/ELV), is a central determinant of cardiovascular performance and cardiac energetics. EA/ELV can be indexed by the ratio of effective arterial elastance (EA; a measure of the net arterial load exerted on the left ventricle) to left ventricular end-systolic elastance (ELV; a load-independent measure of left ventricular chamber performance). At rest, in healthy individuals, EA/ELV is maintained within a narrow range, which allows the cardiovascular system to optimize energetic efficiency at the expense of mechanical efficacy. During exercise, an acute mismatch between the arterial and ventricular systems occurs, due to a disproportionate increase in ELV (from an average of 4.3 to 13.2, and 4.7 to 15.5 mmHg·ml−1·m−2 in men and women, respectively) vs. EA (from an average of 2.3 to 3.2, and 2.3 to 2.9 mmHg·ml−1·m−2 in men and women, respectively), to ensure that sufficient cardiac performance is achieved to meet the increased energetic requirements of the body. As a result EA/ELV decreases from an average of 0.58 to 0.34, and 0.52 to 0.27 in men and women, respectively. In this review, we provide an overview of the concept of EA/ELV, and examine the effects of age, hypertension, and heart failure on EA/ELV and its components (EA and ELV) in men and women. We discuss these effects both at rest and during exercise and highlight the mechanistic insights that can be derived from studying EA/ELV.
Smooth Pursuit Eye Movements to Isoluminant Targets
Authors: Braun D. I. , Mennie N. , Rasche C. , Schütz A. C. , Hawken M. J. , Gegenfurtner K. R.
Published: July 2008

At slow speeds, chromatic isoluminant stimuli are perceived to move much slower than comparable luminance stimuli. We investigated whether smooth pursuit eye movements to isoluminant stimuli show an analogous slowing. Beside pursuit speed and latency, we studied speed judgments to the same stimuli during fixation and pursuit. Stimuli were either large sine wave gratings or small Gaussians blobs moving horizontally at speeds between 1 and 11°/s. Targets were defined by luminance contrast or color. Confirming prior studies, we found that speed judgments of isoluminant stimuli during fixation showed a substantial slowing when compared with luminance stimuli. A similarly strong and significant effect of isoluminance was found for pursuit initiation: compared with luminance targets of matched contrasts, latencies of pursuit initiation were delayed by 50 ms at all speeds and eye accelerations were reduced for isoluminant targets. A small difference was found between steady-state eye velocities of luminance and isoluminant targets. For comparison, we measured latencies of saccades to luminance and isoluminant stimuli under similar conditions, but the effect of isoluminance was only found for pursuit. Parallel psychophysical experiments revealed that different from speed judgments of moving isoluminant stimuli made during fixation, judgments during pursuit are veridical for the same stimuli at all speeds. Therefore information about target speed seems to be available for pursuit eye movements and speed judgments during pursuit but is degraded for perceptual speed judgments during fixation and for pursuit initiation.
Ethanol Effects on Dopaminergic Ventral Tegmental Area Neurons During Block ofIh: Involvement of Barium-Sensitive Potassium Currents
Authors: McDaid John , McElvain Maureen A. , Brodie Mark S.
Published: July 2008

The dopaminergic neurons of the ventral tegmental area (DA VTA neurons) are important for the rewarding and reinforcing properties of drugs of abuse, including ethanol. Ethanol increases the firing frequency of DA VTA neurons from rats and mice. Because of a recent report on block of ethanol excitation in mouse DA VTA neurons with ZD7288, a selective blocker of the hyperpolarization-activated cationic current Ih, we examined the effect of ZD7288 on ethanol excitation in DA VTA neurons from C57Bl/6J and DBA/2J mice and Fisher 344 rats. Ethanol (80 mM) caused only increases in firing rate in mouse DA VTA neurons in the absence of ZD7288, but in the presence of ZD7288 (30 μM), ethanol produced a more transient excitation followed by a decrease of firing. This same biphasic phenomenon was observed in DA VTA neurons from rats in the presence of ZD7288 only at very high ethanol concentrations (160–240 mM) but not at lower pharmacologically relevant concentrations. The longer latency ethanol-induced inhibition was not observed in DA VTA neurons from mice or rats in the presence of barium (100 μM), which blocks G protein–linked potassium channels (GIRKs) and other inwardly rectifying potassium channels. Ethanol may have a direct effect to increase an inhibitory potassium conductance, but this effect of ethanol can only decrease the firing rate if Ihis blocked.
Behavioral States, Network States, and Sensory Response Variability
Authors: Fontanini Alfredo , Katz Donald B.
Published: July 2008

We review data demonstrating that single-neuron sensory responses change with the states of the neural networks (indexed in terms of spectral properties of local field potentials) in which those neurons are embedded. We start with broad network changes—different levels of anesthesia and sleep—and then move to studies demonstrating that the sensory response plasticity associated with attention and experience can also be conceptualized as functions of network state changes. This leads naturally to the recent data that can be interpreted to suggest that even brief experience can change sensory responses via changes in network states and that trial-to-trial variability in sensory responses is a nonrandom function of network fluctuations, as well. We suggest that the CNS may have evolved specifically to deal with stimulus variability and that the coupling with network states may be central to sensory processing.
Zeolite Encapsulated Nanocrystalline CuO: A Redox Catalyst for the Oxidation of Secondary Alcohols
Authors: Vijaikumar Sakthivel , Subramanian Thirumeni , Pitchumani Kasi
Published: July 2008

Zeolite encapsulated nanocrystalline CuO is synthesized and characterized by powder XRD and HRTEM analyses which clearly show that the particles are less than 15 nm and the nanoparticles are highly dispersed. This nano CuO encapsulated CuY zeolite is used as catalyst in the oxidation of aromatic secondary alcohols. CuY zeolite acts as an efficient support for nano CuO, by stabilizing it and preventing its aggregation. Plausible mechanisms for the formation of the various products are also given.
Bilateral Morgagni Hernia: Primary Repair without a Mesh
Authors: Papanikolaou Vassilios , Giakoustidis Dimitrios , Margari Paraskevi , Ouzounidis Nikolaos , Antoniadis Nikolaos , Giakoustidis Alexander , Kardasis Dimitrios , Takoudas Dimitrios
Published: July 2008

We present a case of bilateral Morgagni hernia in a 68-year-old male with an intermittent history of progressive onset of breath shortness and occasional cardiac arrhythmias. Diagnosis was made by clinical examination and the findings in a plain chest radiograph and was confirmed by computed tomography scan. The patient was operated electively and subjected to a transabdominal approach. A bilateral subcostal incision revealed a large right side anterior diaphragmatic defect with a hernia containing the ascending colon, the majority of the transverse colon and a huge amount of omentum. Also a second smaller defect was found on the left side with no hernia inside. After large bowel and omentum had been taken down to the peritoneal cavity, both defects were primarily closed using interrupted nylon sutures without the use of a mesh. The patient recovered very well, had an uneventful postoperative course and was released on the 5th postoperative day. 15-month follow-up failed to reveal any signs of recurrence.
Conducting Labor in Women with Previous Caesarean Section in a Low Gestational Week
Authors: Binder Tomáš , Hájek Zdeněk , Zoban Petr , Plavka Richard
Published: July 2008

Aims: To assess whether vaginal labor after a previous caesarean section in a low gestational week performed by means of a high placed U-section technique could be recommended by obstetricians as a sufficiently safe method of choice for pregnant women. Methods: Of 309 pregnant women with a history of a high placed U-section, 166 (53.7%) met the criteria for the subsequent vaginal delivery and agreed with it. In 78%, vaginal labor started spontaneously and in 22% it was induced due to postterm pregnancy or preterm rupture of membranes. Results: Vaginallabor was successful in 72.3% of women. Deliveries after spontaneous onset of uterine contractions (80%) were considerably more successful. In the group of women with induced labor, the success rate was below 50%. Uterine rupture was not encountered in the study group. Conclusions: Vaginal labor after a previous high placed U-section is a sufficiently safe method of choice for selected groups of pregnant women, but it has to be mentioned that selecting criteria can only minimize and not entirely exclude the risk of uterine rupture.
Molecular Characterization of Inflammation and Staphylococcus aureus Colonization of Involved Skin of Atopic Dermatitis Patients
Authors: Casas C. , Ginisty H. , Alvarez-Georges S. , Viodé C. , Lejeune O. , Rouvrais C. , Schmitt A.M. , Redoulès D.
Published: July 2008

Atopic dermatitis (AD) is a multifactorial chronic inflammatory disease mainly stemming from a genetic predisposition that leads to hypersensitivity to environmental factors and a common involvement of Staphylococcus aureus (SA) colonization. The aim of this work was to propose a new non-invasive approach to enumerate the genes coding for the toxins of SA in atopic skin samples. In parallel, the study aimed to evaluate the change in AD through 3 markers of the inflammatory response: IL-8, IL-1RA/IL-1α and IL-18. These methods were tested on 31 patients with AD, and finally on a group of 19 subjects for whom clinical improvement had been reported after various treatments. The study revealed the presence of a large number of genes encoding toxins in atopic samples, indicating a high rate of SA colonization, and also an increase in the level of all cytokine markers in atopic skin compared to the skin of healthy subjects. Finally, we found a positive correlation between increases in the SCORAD (Scoring Atopic Dermatitis Index) value after treatment and the corresponding evolution of the SA density. These methods provide a means to clinically evaluate the course of AD, and may help in the development of potential treatments.
History of Neonatal Resuscitation – Part 1: Artificial Ventilation
Authors: Obladen Michael
Published: July 2008

The construction of manual ventilators by Hunter, Chaussier, and Gorcy seemed to set the stage for artificial ventilation of the neonate at the end of the 18th century. When Leroy d’Etiolles recognized pneumothorax as a complication of ventilation in 1828, the Paris Academy of Science advised against positive pressure ventilation. Indirect techniques like that of Silvester or the Schultze swingings gained widespread acceptance and prevailed until the First World War. Modern ventilators were developed following the poliomyelitis epidemics in the 20th century.
Power of Genetic Association Studies in the Presence of Linkage Disequilibrium and Allelic Heterogeneity
Authors: Fisher Sheila A. , Lewis Cathryn M.
Published: July 2008

Objectives: The calculation of the power and sample size required for association studies is essential, particularly for follow-up of genome-wide association studies, where much genotyping is required to replicate the original finding and identify the true disease susceptibility mutation. Methods: In this paper, we derive equations for estimation of sample sizes for the transmission disequilibrium test (TDT) and for case-control studies, in the presence of allelic heterogeneity and indirect association – where the genotyped tagging SNP is in linkage disequilibrium (LD) with the true mutation. Using data from NOD2 and PTPN22, we show that the true sample sizes required to detect association may be incorrect when calculated under the assumption of a single mutation and complete LD with the genotyped marker. Results: The true sample sizes may be lower when allelic heterogeneity acts in a recessive model across mutations, or increased when mutations lie on different alleles of a common tagging SNP. Conclusion: Calculating power and sample size under a range of realistic models of LD and allelic heterogeneity is essential to ensure that association studies have sufficient power to detect mutations.
Practical Considerations for Dividing Data into Subsets Prior to PPL Analysis
Authors: Govil M. , Vieland V.J.
Published: July 2008

Objective: The PPL, a class of statistics for complex trait genetic mapping in humans, utilizes Bayesian sequential updating to accumulate evidence for or against linkage across potentially heterogeneous data (sub)sets. Here, we systematically explore the relative efficacy of alternative subsetting approaches for purposes of PPL calculation. Methods: We simulated genotypes for three pedigree sets (sib pairs; 2–3 generations; ≧4 generations) based on families from an ongoing study. For each pedigree set, 100 replicates were generated under different levels of heterogeneity (1000 under ‘no linkage’). Within each replicate, updating was performed across subsets defined randomly (RAND2, RAND4), by true (TRUE) linkage status, with a realistic (REAL) classification, by individual pedigree (PED), or without any subsetting (NONE). Results: Under ‘linkage’, REAL yields larger PPLs compared to NONE, RAND2, RAND4, or PED. Under ‘no linkage’, RAND2, RAND4 and PED yield PPLs close to NONE. Conclusions: We have examined the impact of different subsetting strategies on the sampling behavior of the PPL. Our results underscore the utility of finding variables that can help delineate more homogeneous data subsets and demonstrate that, once such variables are found, sequential updating can be highly beneficial in the presence of appreciable heterogeneity at a linked locus, without inflation at an unlinked locus.
Estimating Disease Risk Associated with Mutated Genes in Family-Based Designs
Authors: Choi Yun-Hee , Kopciuk Karen A. , Briollais Laurent
Published: July 2008

Objective: Many clinical decisions require accurate estimates of disease risk associated with inherited gene mutations. While several family-based designs have been proposed, their relative advantages remain unclear. Methods: We considered four commonly-used family-based designs and evaluated their performance in terms of accuracy and efficiency under several genetic models via simulation studies. We also derived and assessed several ascertainment-corrected likelihood methods for analyzing the simulated data and real data from 12 HNPCC pedigrees from Newfoundland. Results: We found that the design efficiency depends on the question of interest: the clinic-based family design with random probands yields the most efficient estimate of genetic relative risks, whereas the population-based family design with mutation carrier probands provides the most efficient penetrance estimates. For a particular question, an ascertainment correction seems possible using regular likelihood methods but the presence of genetic heterogeneity due to a strong second gene effect can lead to some bias in the risk estimation. Conclusions: This work gives a general methodological framework for analyzing family-based designs in gene characterization studies and provides more rationale for the choice of an efficient design and an appropriate likelihood method to estimate the risk associated with an inherited gene mutation.
Inflammatory Gene Haplotype-Interaction Networks Involved in Coronary Collateral Formation
Authors: Zhang Jian , Regieli Jakub J. , Schipper Maria , Entius Mark M. , Liang Faming , Koerselman Jeroen , Ruven Hendrik J.T. , van der Graaf Yolanda , Grobbee Diederick E. , Doevendans Pieter A.
Published: July 2008

Objectives: Formation of collateral circulation is an endogenous response to atherosclerosis, and is a natural escape mechanism by re-routing blood. Inflammatory response- related genes underlie the formation of coronary collaterals. We explored the genetic basis of collateral formation in man postulating interaction networks between functional Single Nucleotide Polymorphisms (SNPs) in these inflammatory gene candidates. Methods: The contribution of 41 genes as well as the interactions among them was examined in a cohort of 226 coronary artery disease patients, genotyped for 54 candidate SNPs. Patients were classified to the extent of collateral circulation. Stepwise logistic regression analysis and a haplotype entropy procedure were applied to search for haplotype interactions among all 54 polymorphisms. Multiple testing was addressed by using the false discovery rate (FDR) method. Results: The population comprised 84 patients with and 142 without visible collaterals. Among the 41 genes, 16 pairs of SNPs were implicated in the development of collaterals with the FDR of 0.19. Nine SNPs were found to potentially have main effects on collateral formation. Two sets of coupling haplotypes that predispose to collateral formation were suggested. Conclusions: These findings suggest that collateral formation may arise from the interactions between several SNPs in inflammatory response related genes, which may represent targets in future studies of collateral formation. This may enhance developing strategies for risk stratification and therapeutic stimulation of arteriogenesis.
Vulnerabilität früher postnataler Differenzierungsvorgänge der Retina und teratogener Effekt des Zyklophosphamids (Endoxan)
Authors: Foerster H. , Lierse W.
Published: July 2008

During the postnatal period, cyclophosphamide produces in the retina of rats and mice rosettes containing malformed photoreceptor cells arranged in half-circle formations. The rosettes form only after injections given during the first 4 days post partum and only in the receptor layer which contains desmosomes. After this period, the retina becomes resistant to rosette formation. Cytological changes occur in the form of intense nuclear invaginations and membrane whorls, which may be regarded as compensatory processes.
Ultrastrukturelle Reaktion der multipotenten Glia im Kleinhirn der Ratte nach Behandlung mit 6-Aminonikotinamid
Authors: Schaarschmidt W. , Lierse W.
Published: July 2008

6-Aminonicotinamide (6-AN), an antimetabolite of nicotinamide, damages the astrocytes and oligodendrocytes through a blockade of the pentose phosphate pathway. Both types of glia cells become hydropic. A third type of glia cell, described by Vaughn and Peters, the multipotential glia, is affected to a lesser extent. These cells phagocytize and form pseudopodia after treatment with 6-AN. Thus the multipotential glia cells are ‘marked’ by the action of 6-AN, since they are obviously less dependent on the pentose phosphate pathway in the carbohydrate metabolism.
Effect of dose of estradiol and age of animals on intranuclear inclusions in mammotrophs of the Mongolian gerbil
Authors: Nickerson Peter A.
Published: July 2008

Intranuclear inclusions have been examined in mammotrophs of the Mongolian gerbil. No inclusions were identified in nuclei of newborm females, although inclusions were seen in the pituitary gland of young mature females. The number of inclusions in retired breeders was similar to that in young females. Estradiol benzoate increased the number of inclusions, although 10 μg/day for 5 or 14 days induced more inclusions than 5 or 100 μg for 14 days; significantly fewer inclusions were seen with the higher dose (2.81 ± 0.10 inclusions per field for 10 μg and 2.19 ± 0.01 inclusions for 100 μg). Significantly fewer inclusions were present at 3 and 4 weeks. The reduced number of inclusions may be attributable at least in part to cellular hypertrophy of mammotrophs which was especially prominent. Vacuolar inclusions predominated at 3 and 4 weeks and there were fewer membranous types than at previous times.
Dentate nucleus of Ateles ater
Authors: Fix James D.
Published: July 2008

A morphometric analysis of the dentate nucleus of A.ater was performed. Numerical cell densities, cell size, and gray cell coefficients were determined. The selection of this primate was predicated upon phylogenetic and cytoarchitectural criteria. This griseum is cytomorphologically identical to the human dentatum. Quantification was made with both phase contrast and bright-field optics. The gray cell coefficients were determined by Haug’s point-counting method. The dentate nucleus is characterized by the presence of large and small neurons and the typical three glial elements. The ratio between the numerical cell densities of the large and small cells was 1:1. The oligodendrocytes had the highest numerical cell density, followed by the astrocytes, and the Hortega cells. The total glia index was computed to be 13.14. In the corpus medullare, the oligodendrocytes presented the highest numerical cell density; the numerical cell densities of the Hortega cells and the astrocytes were not significantly different from each other. Linear measurements of the glial nuclei revealed that the astrocytes were the largest of the glial elements, showing no difference in size between gray and white matter. The size of the oligodendrocytes in the dentate nucleus corresponded to their size in the white matter. In the corpus medullare, the Hortega cell nuclei are shorter in length than those found in the gray substance. The gray cell coefficients were transformed into volume percentages. Only 9% of the dentate nucleus is composed of nerve cell perikarya and glial cell nuclei; the glial cell nuclei represent only 2% of the total white matter. The morphometric differences existing between the cellular elements in both gray and white substance is correlated with the functional roles ascribed to the neuroglia in relation to capillary and neuronal density. The glial ‘‘satellites’ are predominately oligodendrocytes.
Morphological aspect of the skin terminal corpuscles, previous corrosion with pancreatin
Authors: Alvarez-Morujo A. , Alvarez-Morujo A.J. , Cuervo S. , Cuervo H.
Published: July 2008

The capsulated corpuscles of the skin have been studied by pancreatin corrosion methods. With this corrosion, Meissner’s corpuscles disappear while those, whose fundamental structure is collagenous, remain intact. We have observed structural differences in these collagenous corpuscles, some being formed as a fine reticulum or with longitudinal or concentric sheaths. Within the corpuscle, there is a totally vascular compartment, the ‘vascular hill’, which is easily differentiated from the other laminar or reticular segment which is the ‘nerve hill’. We conclude that the connective tissue arrangement and the vascular content of the corpuscles contribute to the regulation of the different degrees of sensations perceived by these corpuscles. The tendency that these corpuscles show to unite may be caused because the places, where they are grouped, are the points of greatest sensory perception.
Embryonic development of the coronal suture in man and rat
Authors: Markens I.S.
Published: July 2008

Histological examination of skulls of 3- to 7-month-old human fetuses reveals in the fourth month of fetal life the development of a morphologically distinctive tissue in the area between the frontal and parietal bones. In this particular area, the pericranium tends to bulge outward while the dura mater shows the same in an inward direction. Consequently, a spindle-shaped blastema is enclosed. This spindle-like structure is only temporarily present; by about the sixth month of fetal life it has disappeared. Secondly, it was observed that prior to the development of this blastema mainly undifferentiated mesenchymal cells and only few fibroblasts are present in the area between the approaching ossification centres. In the full-grown blastema both types of cells are present in about equal numbers. However, once the blastema has been formed, fibroblasts predominate over mesenchymal cells. This tissue structure is also clearly distinguishable in the developing fetal rat skull. In this species, however, the spindle-shaped blastema appears at a later phase of fetal development, i.e. at about the 20th day. In both species, man and rat, the temporary presence of this blastema is not confined to the presumptive coronal suture only, but is demonstrable as well in other cranial sutures.
Sustained fertility in a non-scrotal mammal, the Indian hedgehog (Hemiechinus auritus Collaris), after CdCl2 administration
Authors: Lohiya N.K. , Dixit V.P.
Published: July 2008

The effects of a single subcutaneous injection of CdQ2 (0.04 mmol/kg body weight) were studied on the testes and caput epididymidis of a non-scrotal mammal, Hemiechinus auritus, and scrotal laboratory mouse. The histological structure of the testes and caput epididymidis of the hedgehog remains normal after 21 days of CdCl2 injection. Testes and sex accessory glands did not show any significant change in weight. The testes and sex accessory organs of mice under comparable condition showed weight loss and involution in tubule diameter. A temperature differential of 1°C was found to exist between the rectum and the cremaster sac of the hedgehog. This small temperature difference and the absence of a counter-current mechanism may be involved in conferring the CdCl2 resistance to the testes and epididymis of the hedgehog.
Electrostimulation and morphologic study of the nerves to the bone marrow of the albino rat
Authors: DePace Dennis M. , Webber Richard H.
Published: July 2008

The innervation of the bone marrow of the albino rat was investigated by electrostimulation and morphological methods. Stimulation of the lumbar sympathetic trunks resulted in the release of reticulocytes and neutrophils into the circulating blood. The effects of stimulation on other cell types in the bone marrow could not be definitely established. It was concluded that the nerve fibers to the bone marrow were distributed to the arteries. It is postulated that the transmitter substance released at the autonomic nerve endings may have an effect upon the permeability of the venous sinusoids and the mobility of the blood cells in the marrow parenchyma resulting in their release into the circulating blood.
Azetylcholinesteraseaktivität in den Spiralganglienzellen der Ratte
Authors: Firbas W. , Klausnitzer I. , Rameis H. , Sinzinger H. , Wicke W.
Published: July 2008

Acetylcholinesterase has been demonstrated in the spiral ganglion cells by the method of Karnovsky and Roots. After incubation for 24 h the content of AchE was measured with the help of a three-stage scale. 22% of the cells showed strong, 50% medium and 28% weak AchE activity. Within the spiral ganglion perikarya, the enzyme was equally distributed.
Hepatocytic ultrastructure in splenectomized rats treated with pregnenolone-16α-carbonitrile, a microsomal enzyme inducer
Authors: Cathala L. , Garg B.D.
Published: July 2008

Pregnenolone-16α-carbonitrile (PCN), given orally at the dose of 6.8 mg/l00 g body wt, twice daily for 3 or 6 days, increased liver weight in intact rats, and reduced zoxazolamine paralysis in both unoperated and splenectomized animals. The steroid induced smooth endoplasmic reticulum proliferation in the hepatocytes of intact and splenectomized rats, while splenectomy alone caused rough endoplasmic reticulum fragmentation and vesiculation. It appears that the spleen does not influence the hepatic action of PCN.
Meal timing dominates the lighting regimen as a synchronizer of the eosinophil rhythm in mice
Authors: Pauly J.E. , Burns E.R. , Halberg F. , Tsai S. , Betterton H.O. , Scheving L.E.
Published: July 2008

Mouse eosinophils undergo circadian fluctuation, and the phasing of the rhythm normally is synchronized to the environmental light-dark cycle if food always is available. This study was undertaken to determine whether or not the same rhythm could be synchronized to restricted feeding schedules. It was found that if food is available ad libitum for only short spans (in this case, 4 h during each 24 h period), the rhythm becomes synchronized to the feeding schedule. In addition, restricting food to certain 4 h spans causes the amplitude of the eosinophil rhythm to increase significantly over that of normal, light-dark synchronized animals. Not all rhythmic variables synchronize to restricted feeding schedules. Some remain synchronized to the light-dark cycle; the phasing of others seems to be the result of an interaction between both the light-dark cycle and the feeding schedule. These studies help dispel the popular misconception that all body functions react in the same manner to different synchronizers and emphasize that one must not generalize about the synchronizing effect of feeding or lighting.
The harp seal, Pagophilus groenlandicus (Erxleben, 1777)
Authors: George J.C. , Ronald K.
Published: July 2008

Three types of fibre, dark (type 1), light (type 2) and intermediate, were distinguished in the caval sphincter muscle of the diaphragm in the harp seal (Pagophilus groenlandicus) using histochemical and electron-microscopic techniques. The dark fibre contained large peripheral aggregations of mitochondria, numerous lipid droplets and dense aggregates of glycogen granules. The same features were observed in the dark fibre of the diaphragm muscle too. In the light of the low oxidative enzyme activity and high lipase activity observed in the diaphragm and other skeletal muscles of the harp seal in previous studies, it is postulated that these mitochondrial aggregations and lipid droplets represent an adaptation for the generation of heat through non-shivering thermogenesis comparable to that in the brown adipose tissue. Such ability to generate and maintain heat by uncoupling the oxidative phosphorylation process should enable the caval sphincter muscle to function efficiently in regulating the cardiac return of blood from the inferior vena cava during a dive when the body temperature as a whole drops. The lack of the regional differences in the fibre composition of the harp seal diaphragm, as were reported in the rat diaphragm, is attributed to the seal’s large body size, lower metabolic rate and diving habit.
Trigeminothalamic fibre connections in the donkey (Equus asinus)studied by means of the retrograde cell degeneration method
Authors: Karamanlidis A.N.
Published: July 2008

In this study the left thalamus of seven very young donkeys was transected and the trigeminothalamic fibre connections were investigated by means of the retrograde cell degeneration method. The animals were allowed to survive for a period of 15–45 days and the paraffin sections of the brain stem were stained according to the Klüver-Barrera and the thionine methods. It was found that the principal sensory trigeminal nucleus exhibited retrograde cell changes and cell losses, in its dorsal part, only at the side ipsi-lateral to the thalamic transection. As far as the nucleus of the spinal tract is concerned, slight changes were found, mainly contralaterally, in its oral subnucleus only. These findings suggest that in the donkey the main trigeminothalamic projection follows an ipsilateral course to the thalamus.
Human embryo (12 mm) with mesohydronephrosis and ureterohydronephrosis
Authors: Ruano-Gil D. , Tejedo-Mateu A.
Published: July 2008

This report describes a human embryo with a length of 12 mm (horizon XVII Streeter, 35 ± 1 day old), in which the following malformations appear: Dilatation on both sides of the Wolffian ducts, and the more caudal mesonephritic glomerules (mesohydronephrosis). Dilatation of both ureters and renal pelvis (ureterohydronephrosis). These malformations are the result of the accumulation of liquid secreted by the mesonephros in a cloaca which is dilated, unwalled and blocked by an epithelial plug which is continuous with the cloacal membrane.
Observations on the effects of 17-α-pregn-4-en-20-yno-(2,3-d) isoxazol-17-ol (Danazol) on the female reproductive tract and pituitary gonadotrophs of gerbil (Meriones hurrianae)
Authors: Dixit V.P. , Lohiya N.K. , Arya Manjuia
Published: July 2008

Danazol caused leukolysis in adult female gerbils. It brings about suppression of ovarian weight, presumably by inhibiting gonadotrophin secretion from the pituitary gland. Uterotrophic action of Danazol is confirmed in ovariectomized animals. Danazol counteracted the uterotrophic effect of an exogenous oestrogen. Vaginal smears of Danazol-treated animals retained a dioestrous leukocytic pattern indicating the absence of follicular activity. Decreased RNA synthesis in the uterus indicates the possibility that Danazol is anti-oestrogenic. Castration-like changes were noticed in the anterior lobe of the hypophysis after Danazol administration.
Seasonal studies on the adrenal homologue of female Puntius sophore(Ham.)
Authors: Dixit R.K. , Agrawala N.
Published: July 2008

In female P. sophore the adrenal homologue is located inside its head kidneys and comprises interrenal cells and chromaffin cells. The clumps of interrenal cells surround the postcardinal vein and its major branches; they also lie in the haemopoietic tissue. The chromaffin cells mostly lie in the endothelium of the post-cardinal vein, while a few of them also lie interspersed among the interrenal cells. The seasonal study of the adrenal homologue shows that the interrenal cells undergo changes in bulk and composition in different months, while the chromaffin cells do not show any significant variation.
Histopathology of the endocrine pancreas of a fresh-water fish, Clarias batrachus (L.)
Authors: Khanna S.S. , Bhatt S.D.
Published: July 2008

Intramuscular administration of epinephrine in 2 mg/kg and 5 mg/kg body weight doses to Clarias batrachus caused significant hyperglycemia between 12 and 18 h after treatment. The hormone produced a small decrease in the liver glycogen, but induced a notable fall in the glycogen of muscles and a transient increase in the brain glycogen. Light-microscopical examination of the pancreatic islets revealed degranulation and vacuolization of the β-cells accompanied by acute necrosis. Damage to the α-cells was also noticed in hyperglycemic fish. The changes in the cellular configuration of the islets, blood glucose and on the tissue glycogen contents were dose-dependent. It is suggested that epinephrine alters the carbohydrate metabolism through the α-cells of the islets.
Functional morphology of the interrenal and chromaffin cells in the teleosts, Rasbora daniconius (Hamilton), Barbus stigma (Cuv. et Val.) and Channa gachua (Hamilton)
Authors: Hooli M.A. , Nadkarni V.B.
Published: July 2008

The interrenal cells in Rasbora daniconius, Barbus stigma and Channa gachua are mainly found around the posteardinal vein and its major branches in the haemopoietic head-kidney. The chromaffin cells which are identified by the positive chromaffin reaction are found in the walls of the posteardinal vein or dispersed among the interrenal cells. Δ5–3β-HSDH and G-6-PDH activity was observed in the interrenal cells of all three teleosts. The present work indicates that the interrenal cells are capable of steroid biosynthesis and the chromaffin cells contain biologically active catecholamines.