bluuebunny/crossref_metadata_2025 huggingface dataset:
Heat shock proteins of chicken lens
Authors: Bagchi M. , Ireland M. , Katar M. , Maisel H.
Published: August 2002

The presence of heat shock proteins HSP‐40, HSP‐70, and HSc‐70 in adult and embryonic chicken lenses were determined. The epithelium, cortex, and nucleus of adult chicken lens were separated and tested for the presence of heat shock proteins (hsps) by western blot, using specific antibodies for HSP‐40, HSP‐70, and HSc‐70. Water soluble (WSF) and water insoluble fractions (WIF) of embryonic chicken lenses were isolated and tested for the presence of HSP‐40, HSP‐70, and HSc‐70 by immunoblot. Embryonic chicken lens sections were also analyzed for the presence of heat shock proteins by immunoflorescence technique. Data obtained from these experiments revealed that HSP‐40, HSP‐70, and HSc‐70 are present in all areas of both adult and embryonic chicken lens. Presence of hsps protein in the deep cortex and nucleus is intriguing as no detectable metabolic activities are reported in this area. However it can be proposed that hsps HSP‐40, HSP‐70, and HSc‐70 can interact with protein of these areas and protect them from stress induced denaturation. J. Cell. Biochem. 82:409–414, 2001. © 2001 Wiley‐Liss, Inc.
Multiple role of reactive oxygen species in the arterial wall
Authors: Napoli Claudio , de Nigris Filomena , Palinski Wulf
Published: August 2002

Increased oxidative stress plays an important role in vascular dysfunction and atherogenesis. Both systemic factors, such as hypercholesterolemia and hyperglycemia, and local factors, such as activation of macrophages and T cells, may contribute to oxidative stress. Oxidation of lipids in lipoproteins and cell membranes leads to functionally important modifications of proteins that affect their recognition by cell surface receptors and protein–protein interactions within the cell, including DNA binding. Oxidized LDL and extracellular oxidation modulate oxidation‐sensitive signaling pathways, but it is not clear to what extent this results from receptor‐mediated activation or from direct effects on the intracellular redox‐balance. Extensive evidence indicates that reactive oxygen species (ROS) regulate gene expression by modulating a large number of transcription factors, including the nuclear transcription factor kappa B (NFκB), the peroxisome proliferator activated receptorγ (PPARγ), and pathways linked to apoptosis. It is also increasingly recognized that cell differentiation and proliferation, cytokine expression, and programmed cell death are determined by the interactions between oxidation‐sensitive regulatory pathways previously thought to lead to distinct outcomes. Because hypercholesterolemia exerts pro‐oxidant effects both intra‐ and extracellularly and because increased ROS formation affects vascular reactivity and atherogenesis by modulating multiple signaling pathways and transcriptional events, future investigations of its atherogenic mechanisms should place greater emphasis on the net effect of such modulation on the expression of a large spectrum of genes. One way of doing this will be by defining clusters of genes responding to hypercholesterolemic stimuli—or interventions with structurally unrelated antioxidants—in analogous ways, irrespective of what regulatory pathway they are controlled by. Microarray technologies that allow simultaneous assessment of large numbers of genes may provide a tool for this approach. J. Cell. Biochem. 82: 674–682, 2001. © 2001 Wiley‐Liss, Inc.
Theoretical calculation of the coiled‐coil stability in water in the context of its possible use as a molecular rack
Authors: Orzechowski Marek , Cieplak Piotr , Piela Lucjan
Published: August 2002

The coiled‐coil stability and rigidity may be of importance for molecular electronics (electronically bistable molecules). The coiled‐coil binding free energy has been calculated using molecular dynamics (MD). The energy has been computed as a difference of the appropriate free energies; derived for the coiled‐coil and isolated α‐helices separately. All MD simulations have been performed using an explicit model of the solvent, whereas the continuum solvent approach has been applied to analyze the MD trajectories. The computed stability of the coiled‐coil is of the order of −87 kcal/mol, i.e., about −1.2 kcal/mol per amino acid residue, and arises mainly from the electrostatic interactions and hydrophobic effect. The entropy term has been roughly estimated to be of the order of −22 kcal/mol. This assures that coiled‐coil polypeptides may be used as a stable molecular scaffolding. © 2002 Wiley Periodicals, Inc. J Comput Chem 23: 106–110, 2002
Molecular detection and identification of an enterovirus during an outbreak of aseptic meningitis
Authors: Siafakas Nikolaos , Georgopoulou Amalia , Markoulatos Panayotis , Spyrou Niki , Stanway Glyn
Published: August 2002

Stool samples from sixteen cases of children with meningitis originating from four different and geographically isolated parts of Greece were investigated for enteroviruses. The conventional method of cell culture in four different cell lines was initially used for the isolation of enteroviruses. The results showed a cytopathic effect (CPE) in all cases after two, or even more successive passages in only one cell line (RD), although a less‐than‐satisfactory CPE was obtained in many cases. Seroneutralization with RIVM mixed hyperimmune antisera followed and the isolates were typed as Coxsackie B viruses. The method of RT‐PCR with enterovirus‐specific primers targeted to the highly conserved 5′‐UTR of the genome was initially used for the detection of enteroviruses from the inoculated cell cultures. A positive RT‐PCR result was obtained for all of the clinical samples rapidly and accurately and the isolates were further characterized with the aid of Restriction Fragment Length Polymorphism (RFLP) analysis and Single Strand Conformation Polymorphism analysis (SSCP) of the amplicons. The RFLP analysis showed first of all that the isolates had an identical restriction pattern with Coxsackie B5 Faulkner reference strain with 4 out of 5 restriction enzymes and secondly, both RFLP and SSCP analysis indicated the epidemiological association of the isolates. The speed of the molecular methodology that was used in comparison with the conventional methods and its possible significance for the description of virus evolution and circulation in the populations is discussed. J. Clin. Lab. Anal. 15:87–95, 2001. © 2001 Wiley‐Liss, Inc.
Incidental recall on WAIS‐R digit symbol discriminates Alzheimer's and Parkinson's diseases
Authors: Demakis George J. , Sawyer Thomas P. , Fritz Dawn , Sweet Jerry J.
Published: August 2002

The purpose of this study was to examine how Alzheimer's (n = 37) and Parkinson's (n = 21) patients perform on the incidental recall adaptation to the Digit Symbol of the Wechsler Adult Intelligence Scale—Revised (WAIS‐R) and how such performance is related to established cognitive efficiency and memory measures. This adaptation requires the examinee to complete the entire subtest and then, without warning, to immediately recall the symbols associated with each number. Groups did not differ significantly on standard Digit Symbol administration (90 seconds), but on recall Parkinson's patients recalled significantly more symbols and symbol‐number pairs than Alzheimer's patients. Using only the number of symbols recalled, discriminate function analysis correctly classified 76% of these patients. Correlations between age‐corrected scaled score, symbols incidentally recalled, and established measures of cognitive efficiency and memory provided evidence of convergent and divergent validity. Age‐corrected scaled scores were more consistently and strongly related to cognitive efficiency, whereas symbols recalled were more consistently and strongly related to memory measures. These findings suggest that the Digit Symbol recall adaptation is actually assessing memory and that it can be another useful way to detect memory impairment. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 387–394, 2001.
The impact of Thought Field Therapy on heart rate variability
Authors: Callahan Roger J.
Published: August 2002

Thought Field Therapy (TFT) is a rapid treatment for psychological problems typically taking only minutes. HRV has been shown to be a strong predictor of mortality and is adversely affected by such problems as anxiety, depression, and trauma. Interventions presented in the current literature show modest improvements in HRV. Twenty cases, treated by the author and other therapists with TFT, are presented. The cases include some with diagnosed heart problems and very low HRV, which is ordinarily more resistant to change. The degree of improvements that are registered on HRV as a result of TFT treatment exceeds reports found in the current literature. There is a close correspondence between improved HRV and client report of reduced degree of upset. HRV may prove to be an appropriate objective measure of psychotherapy efficacy given the correspondence between client report and HRV outcome. Further research in TFT and HRV is encouraged by these results. © 2001 John Wiley & Sons, Inc. J Clin Psychol 57: 1153–1170, 2001.
Development of the reasons for living inventory for young adults
Authors: Gutierrez Peter M. , Osman Augustine , Barrios Francisco X. , Kopper Beverly A. , Baker Monty T. , Haraburda Cheryl M.
Published: August 2002

Assessment of the reliability, validity, and predictive power of a new measure, the Reasons for Living Inventory for Young Adults (RFL‐YA) is described. A series of three studies was conducted at two Midwestern universities to develop initial items for this new measure, refine item selection, and demonstrate the psychometric properties of the RFL‐YA. The theoretical differences between the RFL‐YA and the College Student Reasons for Living Inventory (CS‐RFL) are discussed. Although the two measures were not directly compared, it appears that the RFL‐YA has greater specificity for exploring aspects of the protective construct and may be more parsimonious than the CS‐RFL. Principal‐axis factor analysis yielded a five‐factor solution for the RFL‐YA accounting for 61.5% of the variance. This five‐factor oblique model was confirmed in the final phase of investigation. Alpha estimates for the five subscales ranged from .89 to .94. Concurrent, convergent‐discriminant, and criterion validity also were demonstrated. The importance of assessing protective factors in addition to negative risk factors for suicidality is discussed. Directions for future research with the RFL‐YA also are discussed. © 2002 Wiley Periodicals, Inc. J Clin Psychol 58: 339–357, 2002.
Cultural and spiritual coping in sobriety: Informing substance abuse prevention for Alaska Native communities
Authors: Hazel Kelly L. , Mohatt Gerald V.
Published: August 2002

Culture and spirituality have been conceptualized as both protecting people from addiction and assisting in the recovery process. A collaborative study, utilizing focus group and survey methods, defined and examined cultural and spiritual coping in sobriety among a select sample of Alaska Natives. Results suggest that the Alaska Native worldview incorporates a circular synthesis and balance of physical, cognitive, emotional, and spiritual processes within a protective layer of family and communal/cultural beliefs and practices embedded within the larger environment. Cultural‐spiritual coping in sobriety is a process of appraisal, change, and connection that leads the person toward achieving an overarching construct: a sense of coherence. Cultural and spiritual processes provide important areas for understanding the sobriety process as well as keys to the prevention of alcohol abuse and addiction. © 2001 John Wiley & Sons, Inc.
Structured after‐school activities as a moderator of depressed mood for adolescents with detached relations to their parents
Authors: Mahoney Joseph L. , Schweder Amanda E. , Stattin Håkan
Published: August 2002

This study investigated whether participation in structured after‐school activities moderates the association between detached parent–adolescent relationships and adolescent depressed mood. A representative sample of 539 14‐year‐olds and their parents were assessed concerning adolescent participation in after‐school activities, the parent–adolescent relationship, and adolescent depressed mood. Results showed that adolescents with detached relations to their parents reported high levels of depressed mood. Adolescents who participated in after‐school activities reported low levels of depressed mood compared to adolescents not participating in such activities; however, this was primarily true of participants who perceived high support from their activity leader. Support from after‐school activity leaders was particularly important for a subgroup of youth characterized by highly detached relations to their parents. Although girls reported higher levels of depressed mood than did boys, the associated benefits of perceived support from an activity leader were consistent across gender. © 2002 John Wiley & Sons, Inc.
Renal fungal ball: An unusual sonographic finding
Authors: Kale Hrishikesh , Narlawar Ranjeet S. , Rathod Krantikumar
Published: August 2002

Fungal infections of the urinary tract tend to occur in the drainage structures instead of the renal parenchyma. In patients with systemic candidiasis, the kidney is vulnerable to the formation of cortical abscesses or obstructive intrarenal masses (“fungal balls”), usually at the ureteropelvic junction. We describe the case of a boy who presented with dysuria, fever, and chills. Sonographic examination showed mild enlargement of both kidneys and moderate dilatation of the pelvicaliceal system bilaterally. A well‐defined, echogenic, oval, mobile mass measuring 2.5 × 2.0 cm, without posterior acoustic shadowing, was visualized in the pelvis of the left kidney. The upper and middle ureters were dilated bilaterally. A urine culture revealed hyphae of Candida albicans. The child received systemic antifungal therapy with fluconazole for 3 weeks. Follow‐up sonography showed complete resolution of the mass (a fungal ball) with residual hydronephrosis. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:178–180, 2002; DOI 10.1002/jcu.10049
Sonographic measurement of the volume of the left lateral segment of the liver
Authors: Hatsuno Tsuyoshi , Kaneko Tetsuya , Ito Shigeki , Nakao Akimasa
Published: August 2002

Purpose

The aim of this study was to evaluate the accuracy of sonography for measuring the volume of the left lateral segment of the liver.

Methods

The volume of the left lateral segment of the liver was measured with sonography in 101 consecutive patients who were hospitalized between December 1998 and January 2000 for hepatic, biliary, or pancreatic disease or who were donors for a living related liver transplantation. The results were compared with those obtained using CT.

Results

The mean calculated volume of the left lateral segment of the liver ± standard deviation was 261 ± 118 cm3 by sonography compared with 274 ± 123 cm3 by CT. The relationship between the results of both imaging modalities was linear and statistically significant (r = 0.93; p < 0.0001).

Conclusions

Our study demonstrated that sonography has an acceptable level of accuracy and reliability for routine measurement of the volume of the left lateral segment of the liver. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:117–122, 2002; DOI 10.1002/jcu.10050
Gender‐related changes in the avian vasotocin system during ontogeny
Authors: Jurkevich Aleksandr , Grossmann Roland , Balthazart Jacques , Viglietti‐Panzica Carla
Published: August 2002

The arginine vasotocin (AVT) system of the avian brain includes a sexually dimorphic part that extends from the caudal part of preoptic region through the medial part of the bed nucleus of stria terminalis (BSTm) to the lateral septum. It is composed of the parvocellular neurons located in the BSTm and the dense innervation of the medial preoptic region and lateral septum. In this part of the brain, AVT expression is stronger in males than in females in a few bird species investigated to date. This review focuses on the ontogeny of sexual differences in the vasotocinergic system of two gallinaceous species, domestic chicken and Japanese quail, and on the role of gonadal hormones in organizing during development and maintaining in adulthood these differences. Parvocellular AVT neurons become discernible in the BSTm of males and females during the second half of embryonic development. These cells undergo a profound and irreversible sexual differentiation during ontogenetic development. Recent findings demonstrate a dual role of estrogens in the organization and activation of sex differences in the AVT system. During the embryonic period of ontogeny, estrogens differentiate the AVT system in a sexually dimorphic manner in parallel with the differentiation of sexual behavior, while in adulthood estrogens, locally produced from testosterone in the male brain, activate AVT synthesis in the BSTm. The sexually dimorphic part of the AVT system is sensitive to a number of abiotic factors such as light, temperature, and water availability. It is suggested that sex dimorphic vasotocinergic systems could be implicated in processes of social recognition in various behavioral contexts. Microsc. Res. Tech. 55:27–36, 2001. © 2001 Wiley‐Liss, Inc.
Antennal multiporous sensilla: Their gustatory features for host recognition in female parasitic wasps (insecta, Hymenoptera: Platygastroidea)
Authors: Isidoro Nunzio , Romani Roberto , Bin Ferdinando
Published: August 2002

In parasitic wasps, various kinds of antennal plates have been interpreted as olfactory organs due to the presence of numerous pores. However, on the basis of ultrastructural investigations, some of these multiporous plates were revealed as being release sites of exocrine glands while others were postulated to have a gustatory function. Such sensilla, present only on female antennae, show unique features, found exclusively in Platygastroidea, with some differences between Scelionidae and Platygastridae. The cuticular apparatus consists of a short basiconic shaft with an apical multiporous area, the pores of which are covered by movable structures. The cellular components are made up of a remarkable number of sensory neurons, from 200 to 220, and an undefined number of sheath cells. These multiporous sensilla have tubular accessory glands that release their secretion through the socket sensillum only in scelionids. These morphological characters, combined with behavioral observations, strongly suggest a gustatory function, although electrophysiological studies are still needed to confirm this. A new terminology for antennal multiporous plates is discussed in relation to their different functions. Microsc. Res. Tech. 55:350–358, 2001. © 2001 Wiley‐Liss, Inc.
Modulation of goldfish testicular testosterone production in vitro by tumor necrosis factor α, interleukin‐1β, and macrophage conditioned media
Authors: Lister Andrea , Van Der Kraak Glen
Published: August 2002

The relevance of immune‐endocrine interactions to the regulation of testicular steroidogenesis in teleosts is virtually unexplored. The objectives of the present study were: 1) to investigate the effects of murine cytokines, tumor necrosis factor‐α (TNFα) and interleukin‐1β (IL‐1β), and trout (Oncorhynchus mykiss) macrophage conditioned media (MCM) on testosterone (T) production by goldfish (Carassius auratus) testis pieces in vitro; and 2) to identify the site(s) of the inhibitory action of TNFα on hCG‐stimulated T formation. TNFα (0–100 ng/ml) affected basal T production differentially depending on the gonadosomatic index (GSI) value of the fish. TNFα stimulated basal T of fish with a relatively low GSI (average 1.99), but inhibited T production by testis of fish with a higher GSI (average 5.14). The remaining studies used fish with only high GSI values. IL‐1β (0–10 ng/ml) inhibited basal T production, while MCM (0–25% v/v) had no effect. The cytokines significantly inhibited hCG‐stimulated T production at all doses tested, whereas MCM was inhibitory only at the lower doses of 2.5–5% v/v. TNFα did not affect basal or hCG‐stimulated cAMP levels, but did inhibit forskolin (0.5 μM; adenylate cyclase activator) and 8‐bromo‐cAMP (0.15 mM; cAMP analog) stimulated T levels. The inhibitory actions of TNFα on T production were greatly reduced by treatment of testis with 25‐hydroxycholesterol (1 and 10 μg/ml), pregnenolone (50 and 100 ng/ml), and 17α‐hydroxypregesterone (50 ng/ml). TNFα caused a moderate decrease in pregnenolone (100 ng/ml)‐stimulated T production. Together, these data demonstrate that regulatory actions of TNFα may occur at multiple sites within the steroid biosynthetic pathway, but the major effect appears to be related to cholesterol availability in the mitochondria. In conclusion, the results of this study implicate macrophage‐derived factors in the regulation of teleost testicular androgen biosynthesis. J. Exp. Zool. 292:477–486, 2002. © 2002 Wiley‐Liss, Inc.
Compaction in preimplantation mouse embryos is regulated by a cytoplasmic regulatory factor that alters between 1‐ and 2‐cell stages in a concentration‐dependent manner
Authors: Lee Dong Ryul , Lee Jeoung Eun , Yoon Hyun Soo , Roh Sung Il , Kim Moon Kyoo
Published: August 2002

Present studies were performed to investigate what factors affect the morphogenesis of preimplantation mouse embryos, and to find the action mechanism of that factor by using cytoplasm removal and its reconstitution from a different developmental stage embryo. Half (HP group) or one‐third of cytoplasm (TP group) was removed from 1‐cell mouse embryos by micromanipulation, and their morphogenesis and genome expression were compared with sham‐operated embryos (SP group). The compaction and blastocoel formation of embryos in both the HP and TP groups were accelerated in time and cell stage when compared with those of the SP group. However, the total activity and time of RNA synthesis, and gene expression of ZO‐1α+ isoform were not different. To change the cytoplasm composition without altering the nucleus/cytoplasmic ratio, half a 1‐cell embryo with both pronuclei was reconstituted with the half enucleated cytoplasm of 1‐cell embryo (P + P group), 2‐cell (P + 2 group) or 4‐cell (P + 4 group) by electrofusion. Embryonic compaction, timing of RNA synthesis, and stage‐specific gene expression of the ZO‐1α+ isoform in the P + 2 and P + 4 groups were accelerated in time and cell stage than that in the P + P group, but not different between the P + 2 and P + 4 groups. In addition, a blastomere of 2‐cell embryo was reconstituted with the enucleated cytoplasm of 1‐cell embryo (2 + P group) or 2‐cell (2 + 2 group) in equal volume by electrofusion. Also, the karyoplast of 2‐cell was fused with the enucleated 1‐cell embryo (2 + PP group). Embryonic development, total activity of RNA synthesis, and gene expression of the ZO‐1α+ isoform of embryos in the 2 + P and 2 + PP groups were delayed when compared with those of the 2 + 2 group. Also, the phenomena of compaction and blastocoel formation were delayed in the development time and cell stage. From these results, the nucleus/cytoplasm ratio was found to have no direct effect on the regulation of embryonic morphogenesis, although it accelerated compaction and blastocoel formation. However, cytoplasmic factors that altered between 1‐ and 2‐cell stages regulate embryonic morphogenesis, especially compaction, of preimplantation mouse embryos in concentration‐dependent manner. J. Exp. Zool. 290:61–71, 2001. © 2001 Wiley‐Liss, Inc.
Limb and tail lengths in relation to substrate usage inTropiduruslizards
Authors: Kohlsdorf Tiana , Garland Jr. Theodore , Navas Carlos A.
Published: August 2002

A close relationship between morphology and habitat is well documented for anoline lizards. To test the generality of this relationship in lizards, snout‐vent, tail, and limb lengths of 18 species ofTropidurus(Tropiduridae) were measured and comparisons made between body proportions and substrate usage. Phylogenetic analysis of covariance by computer simulation suggests that the three species inhabiting sandy soils have relatively longer feet than do other species. Phylogenetic ANCOVA also demonstrates that the three species inhabiting tree canopies and locomoting on small branches have short tails and hind limbs. These three species constitute a single subclade within the overallTropidurusphylogeny and analyses with independent contrasts indicate that divergence in relative tail and hind limb length has been rapid since they split from their sister clade. Being restricted to a single subclade, the difference in body proportions could logically be interpreted as either an adaptation to the clade's lifestyle or simply a nonadaptive synapomorphy for this lineage. Nevertheless, previous comparative studies of another clade of lizards (Anolis) as well as experimental studies ofSceloporuslizards sprinting on rods of different diameters support the adaptive interpretation. J. Morphol. 248:151–164, 2001. © 2001 Wiley‐Liss, Inc.
Development of segments and appendages in embryos of the desert scorpion Paruroctonus mesaensis (Scorpiones: Vaejovidae)
Authors: Farley Roger D.
Published: August 2002

The scanning electron microscope was used to study the changing features of scorpion embryos from the blastula through early stages in the development of appendages. The earliest scorpion fossils (Silurian period) have structures more advanced than the embryos herein, so the possibility is considered that these embryos still retain and display some features indicative of evolutionary patterns in adult pre‐Silurian ancestors. The blastodisc stage is followed by a knob‐like germinal center that gives rise to most of the embryo body. The germinal center elongates on the ventral surface of the spherical yolk mass. The broad cephalic lobe is first delineated from the following pedipalpal segment. The limbbuds for the pedipalps and anterior walking legs appear, as additional segments are added at a growth zone at the rear of the embryo body. Initially, in the cephalic lobe there are no limbbuds; then the cheliceral buds emerge from the posterior part of the lobe. The stomodeum appears first in the anterior half of the cephalic lobe, but an oral groove forms and the mouth is displaced posteriorly within the groove. This repositioning allows space anteriorly for invagination (semilunar grooves) of epithelium for the brain and medial eyes. The mouth is directed ventrally in all stages of this study. The widespread chelicerae are initially posterior to the mouth, but later move anterior and dorsal to it. Small limbbud bulges on mesosomal segments disappear later and never become protruding appendages. Metasomal segments are produced free from the yolk surface in a ventral flexure beneath the embryo body. The telson starts as two spherical lobes, but later elongates and tapers distally, not yet developing the sharp sting (aculeus) seen in Silurian and all subsequent scorpions. The walking legs are digitigrade, as in most fossil aquatic scorpions. Segments are delineated in the appendages; the chelicerae and pedipalps are divided distally for chela (claw) formation. Bilateral swellings (limbbuds) on the third abdominal segment become larger than the others, indicating the site of pectine formation. The early fin‐like pectines are somewhat posterior in the mesosoma, suggesting ancestral swimming, maneuvering, and balancing for the elongate abdomen. The pectinal surface is initially smooth but later transverse striations increase the surface area as a possible respiratory adaptation. Pectinal teeth (present in Silurian and all subsequent scorpions) and foward movement and merging of anterior abdominal segments are not yet evident in embryos of this study. J. Morphol. 250:70–88, 2001. © 2001 Wiley‐Liss, Inc.
New vascular system in reptiles: Anatomy and postural hemodynamics of the vertebral venous plexus in snakes
Authors: Zippel Kevin C. , Lillywhite Harvey B. , Mladinich Christopher R.J.
Published: August 2002

Using corrosion casting, we demonstrate and describe a new vascular system—the vertebral venous plexus—in eight snake species representing three families. The plexus consists of a network of spinal veins coursing within and around the vertebral column and was previously documented only in mammals. The spinal veins of snakes originate anteriorly from the posterior cerebral veins and form a lozenge‐shaped plexus that extends to the tip of the tail. Numerous anastomoses connect the plexus with the caval and portal veins along the length of the vertebral column. We also reveal a posture‐induced differential flow between the plexus and the jugular veins in two snake species with arboreal proclivities. When these snakes are horizontal, the jugulars are observed fluoroscopically to be the primary route for cephalic drainage and the plexus is inactive. However, head‐up tilting induces partial jugular collapse and shunting of cephalic efflux into the plexus. This postural discrepancy is caused by structural differences in the two venous systems. The compliant jugular veins are incapable of sustaining the negative intraluminal pressures induced by upright posture. The plexus, however, with the structural support of the surrounding bone, remains patent and provides a lowhyphen;pressure route for venous return. Interactions with the cerebrospinal fluid both allow and enhance the role of the plexus, driving perfusion and compensating for a posture‐induced drop in arterial pressure. The vertebral venous plexus is thus an important and overlooked element in the maintenance of cerebral blood supply in climbing snakes and other upright animals. J. Morphol. 250:173–184, 2001. © 2001 Wiley‐Liss, Inc.
Dental homologies in lamniform sharks (Chondrichthyes: Elasmobranchii)
Authors: Shimada Kenshu
Published: August 2002

The dentitions of lamniform sharks are said to exhibit a unique heterodonty called the “lamnoid tooth pattern.” The presence of an inflated hollow “dental bulla” on each jaw cartilage allows the recognition of homologous teeth across most modern macrophagous lamniforms based on topographic correspondence through the “similarity test.” In most macrophagous lamniforms, three tooth rows are supported by the upper dental bulla: two rows of large anterior teeth followed by a row of small intermediate teeth. The lower tooth row occluding between the two rows of upper anterior teeth is the first lower anterior tooth row. Like the first and second lower anterior tooth rows, the third lower tooth row is supported by the dental bulla and may be called the first lower intermediate tooth row. The lower intermediate tooth row occludes between the first and second upper lateral tooth rows situated distal to the upper dental bulla, and the rest of the upper and lower tooth rows, all called lateral tooth rows, occlude alternately. Tooth symmetry cannot be used to identify their dental homology. The presence of dental bullae can be regarded as a synapomorphy of Lamniformes and this character is more definable than the “lamnoid tooth pattern.” The formation of the tooth pattern appears to be related to the evolution of dental bullae. This study constitutes the first demonstration of supraspecific tooth‐to‐tooth dental homologies in nonmammalian vertebrates. J. Morphol. 251:38–72, 2002. © 2002 Wiley‐Liss, Inc.
Towards a rational development of anti‐endotoxin agents: novel approaches to sequestration of bacterial endotoxins with small molecules
Authors: David Sunil A.
Published: August 2002

Endotoxins, or lipopolysaccharides (LPS), present on the surface of Gram‐negative bacteria, play a key role in the pathogenesis of septic shock, a common clinical problem and a leading cause of mortality in critically ill patients, for which no specific therapeutic modalities are available at the present time. The toxic moiety of LPS is a glycolipid called ‘lipid A’, which is composed of a bisphosphorylated diglucosamine backbone bearing up to seven acyl chains in ester and amide linkages. Lipid A is structurally highly conserved in Gram‐negative bacteria, and is therefore an attractive target for developing anti‐endotoxin molecules designed to sequester, and thereby neutralize, the deleterious effects of endotoxins.  The anionic and amphipathic nature of lipid A enables the interaction of a wide variety of cationic amphiphiles with the toxin. This review describes the systematic evaluation of several structural classes of cationic amphiphiles, both peptides and non‐peptidic small molecules, in the broader context of recent efforts aimed at developing novel anti‐endotoxin strategies. The derivation of a pharmacophore for LPS recognition has led to the identification of novel, nontoxic, structurally simple small molecules, the lipopolyamines. The lipopolyamines bind and neutralize LPS inin vitroexperiments as well as in animal models of endotoxicity, and thus present novel and exciting leads for rational, structure‐based development of LPS‐sequestering agents of potential clinical value. Copyright © 2001 John Wiley & Sons, Ltd.
Contrast‐enhanced high resolution MRI for atherosclerotic carotid artery tissue characterization
Authors: Yuan Chun , Kerwin William S. , Ferguson Marina S. , Polissar Nayak , Zhang Shaoxiong , Cai Jianming , Hatsukami Thomas S.
Published: August 2002

Purpose

To determine if a gadolinium‐based contrast agent provides additional information for characterization of human plaque tissues, particularly neovasculature. Although high‐resolution magnetic resonance imaging (MRI) has been used to identify plaque constituents in advanced atherosclerosis, some constituents, such as neovascularized tissue, defy detection.

Materials and Methods

Non‐contrast‐enhanced carotid artery images from 18 patients scheduled for carotid endarterectomy and two normal volunteers were used to identify regions of fibrous tissue, necrotic core, or calcification, using established criteria. Then, the percent change in T1‐weighted images after contrast enhancement was calculated for each region.

Results

There were statistically significant differences in mean intensity change between tissues, with the largest increase for fibrous tissue (79.5%) and the smallest for necrotic core (28.6%). Additionally, histological analysis showed that a subset of fibrous regions rich in plaque neovascularization could be identified using a threshold of 80% enhancement (sensitivity = 76%, specificity = 79%).

Conclusion: The ability of contrast‐enhanced MRI to identify neovascularization and potentially improve differentiation of necrotic core from fibrous tissue further establishes MRI as a viable tool for in vivo study of atherosclerotic plaque. J. Magn. Reson. Imaging 2002;15:62–67. Published 2002 Wiley‐Liss, Inc.
Functional cardiac MR imaging with steady‐state free precession (SSFP) significantly improves endocardial border delineation without contrast agents
Authors: Thiele Holger , Nagel Eike , Paetsch Ingo , Schnackenburg Bernhard , Bornstedt Axel , Kouwenhoven Marc , Wahl Andreas , Schuler Gerhard , Fleck Eckart
Published: August 2002

Contrast between blood and myocardium in standard turbo gradient echo MR techniques (TFE) used routinely in clinical practice is mainly caused by unsaturated inflowing blood. Steady‐state free precession (SSFP) has excellent contrast even in the absence of inflow effects. In 45 subjects cardiac cine loops in two long axis projections were acquired using TFE and compared with SSFP. A visual score (range 0 worst – 3 best) was assigned for endocardial border delineation for six myocardial segments in two long axis views. Endocardial border delineation score for TFE was 1.3 ± 0.3 per segment and 2.4 ± 0.3 for SSFP (P < 0.0001). Signal intensity blood/signal intensity myocardium was 1.5 ± 0.4 at enddiastole and 1.4 ± 0.3 at systole for TFE and 3.5 ± 1.1 and 3.2 ± 1.3 for SSFP, respectively (P < 0.0001). SSFP increases contrast between blood and myocardium more than twofold, resulting in an improved endocardial border definition. This may reduce variability for the determination of cardiac volumes and ejection fraction. J. Magn. Reson. Imaging 2001;14:362–367. ©2001 Wiley‐Liss, Inc.
Functional assessment of pancreatic parenchyma after secretin administration using serial T2‐weighted echo‐planar magnetic resonance imaging
Authors: Masui Takayuki , Katayama Motoyuki , Kobayashi Shigeru , Ito Tatsuhiko , Kabasawa Hiroyuki , Nozaki Atsushi , Sakahara Harumi
Published: August 2002

Signal intensity (SI) changes of pancreatic parenchyma were evaluated after intravenous administration of secretin using T2‐weighted single‐shot spin‐echo echo‐planar imaging (EPI) to assess this method as a magnetic resonance (MR) test of pancreatic exocrine function. Nine volunteers were studied with serial single‐shot EPI of the pancreas for 15 minutes after the injection of secretin or saline. The normal pattern of pancreatic SI change was demonstrated after intravenous injection of secretin, a single peak at 3–4 minutes in the head, body, and tail, followed by a gradual decrease in SI. Saline injection did not induce a significant SI change. There was no statistical difference in the peak contrast ratios (first mean, 1.21–1.25, vs. second mean, 1.18–1.22) and peak times (first mean, 3.2–3.7 minutes, vs. second mean, 3.1–3.6) in a repeat study. By evaluating the pattern of time‐response curves obtained from serial T2‐weighted EPI after secretin injection, pancreatic exocrine function may be directly assessed at the level of the head, body, and tail. J. Magn. Reson. Imaging 2001;14:450–456. © 2001 Wiley‐Liss, Inc.
Reproducibility of T2* blood volume and vascular tortuosity maps in cerebral gliomas
Authors: Jackson A. , Kassner A. , Zhu X.P. , Li K.L.
Published: August 2002

The development of anti‐angiogenic therapies for tumors has led to a demand for imaging‐based surrogate markers of the angiogenic process. The utility of such markers is highly dependent on their test‐retest reproducibility. This paper presents a formal assessment of the reproducibility of measurements of relative blood volume (rBV), normalized rBV (rBVnorm), and vascular tortuosity as estimated by measurement of relative recirculation (rR). The study was conducted in 11 patients with glioma who were scanned on two occasions 36–56 hours apart. The observed reliability estimates were used to calculate 95% confidence limits for detection of differences between groups and for changes in individual cases. The results show that measurement of rBV or rBVnorm in consecutive studies is statistically capable of reliably detecting changes in excess of 15% in between group studies and 25% in individual patients. Measurement of vascular tortuosity using is less reproducible but is able to confidently identify changes in excess of 30% in group studies and 35% in individuals. J. Magn. Reson. Imaging 2001;14:510–516. © 2001 Wiley‐Liss, Inc.
Improved high resolution MR imaging for surface coils using automated intensity non‐uniformity correction: Feasibility study in the orbit
Authors: Vokurka Elizabeth A. , Watson Nick A. , Watson Yvon , Thacker Neil A. , Jackson Alan
Published: August 2002

This study examined the effects of a recently developed automated intensity non‐uniformity correction on surface coil images using the orbit as an exemplar. Images were obtained using a standard head coil and a range of surface coils. Slices through the optic nerve head and cavernous sinus were subjected to the correction algorithm. Blind forced‐choice rankings of the subjective image quality were performed. Quantitative measurements were taken of the similarity between vitreous humor at two depths from the coil, and of the conspicuity between orbital fat and temporalis muscle intensities. The combined qualitative ranks for corrected surface coil images were higher than for the equivalent uncorrected images in all cases. Intensity non‐uniformity correction produced statistically significant improvements in orbital surface coil images, bringing their intensity uniformity in homogeneous tissue to the level of head coil images. The subjective quality of the corrected surface coil images was superior to head coil images, due to increased spatial resolution combined with improved signal to noise ratio across the image. J. Magn. Reson. Imaging 2001;14:540–546. © 2001 Wiley‐Liss, Inc.
A method for fast 3D tracking using tuned fiducial markers and a limited projection reconstruction FISP (LPR‐FISP) sequence
Authors: Flask Chris , Elgort Daniel , Wong Eddy , Shankaranarayanan Ajit , Lewin Jonathan , Wendt Michael , Duerk Jeffrey L.
Published: August 2002

This work demonstrates the feasibility of using wireless, tuned fiducial markers with a limited projection reconstruction–fast imaging with steady‐state free precession sequence (LPR‐FISP) to accurately obtain tracking information necessary for interactive scan plane selection in magnetic resonance imaging (MRI). The position and orientation of a rigid interventional device can be uniquely determined from the 3D coordinates of three fiducial markers mounted in a known configuration on the device. Three fiducial markers were tuned to the proton resonant frequency in a 0.2T open MR scanner and mounted to the surface of a cylindrical water phantom. An LPR‐FISP sequence was developed to suppress the water phantom signal while preserving that of the fiducial markers through a nonselective low‐tip‐angle excitation and a dephaser gradient applied prior to data acquisition. A localization algorithm was developed to accurately calculate the 3D coordinates of the fiducial markers using four LPR‐FISP projections in two orthogonal scan planes. The sequence repetition time (TR = 21 msec) and the limited projection set resulted in fast LPR‐FISP coordinate acquisition times of approximately 170 msec with an accuracy (max error) of 3 mm on a 0.2T MR system. This fast, accurate tracking method provides the fundamental technology for interactive MRI scan plane definition for rigid interventional devices without the need for stereotactic cameras or reference frames. J. Magn. Reson. Imaging 2001;14:617–627. © 2001 Wiley‐Liss, Inc.
Analysis of ethoxylated nonionic surfactants and their metabolites by liquid chromatography/atmospheric pressure ionization mass spectrometry
Authors: Petrovic M. , Barceló D.
Published: August 2002

The widespread use and questionable environmental acceptability of nonionic surfactants make the alkylphenol ethoxylates (APEOs) and their neutral and acidic degradation products a focus of interest in environmental analytical chemistry. The characterization and especially quantification of polyethoxylate mixtures in environmental matrices is a challenge, because of the complexity of the mixtures. A review on trace analysis of APEOs using atmospheric pressure ionization mass spectrometry, including sample preparation and liquid chromatographic separation, is presented. In this Special Feature, the performances of two ionization methods, atmospheric pressure chemical ionization and electrospray ionization, is discussed in terms of selectivity and sensitivity toward oligomeric mixtures of APEOs. Capabilities and limitations associated with the liquid chromatographic/mass spectrometric detection of APEOs, their main degradation products and their halogenated metabolites, and also specific issues related to the sample preparation, formation of fragments, adducts and cluster ions, quantification of oligomeric mixtures and signal suppression effects in complex matrices, are discussed. Conclusions and future perspectives are outlined. Copyright © 2001 John Wiley & Sons, Ltd.
Theoretical analysis of the effect of amplified luminescence on the modulation response of laser diodes
Authors: Burov L. I. , Gribkovskii V. P. , Grigelevich P. S. , Kramar M. I. , Ryabtsev G. I. , Shore K. A. , Voitikov S. V. , Kragler R.
Published: August 2002

A theoretical framework is established for the investigation of the effect of amplified luminescence, non‐radiative recombination, photon losses, and gain non‐linearity on the threshold current characteristics and small‐signal modulation responses of bulk and quantum‐well (QW) 1.3 and 1.55 µm InxGa1−xAsyP1−y/InP laser diodes. It is shown that the rate of recombination induced by amplified luminescence exhibits a highly non‐linear dependence on both carrier concentration and temperature. Amplified luminescence and Auger recombination increase the laser threshold and contribute strongly to the device threshold current temperature sensitivity. Amplified luminescence and Auger recombination are shown to have a significant detrimental effect on the modulation properties of long‐wavelength laser diodes. Copyright © 2001 John Wiley & Sons, Ltd.
Effect of glutamine and GABA on [U‐13C]glutamate metabolism in cerebellar astrocytes and granule neurons
Authors: Qu Hong , Konradsen Jon R. , van Hengel Marike , Wolt Saskia , Sonnewald Ursula
Published: August 2002

To probe the effect of glutamine and GABA on metabolism of [U‐13C]glutamate, cerebellar astrocytes were incubated with [U‐13C]glutamate (0.5 mM) in the presence and absence of glutamine (2.5 mM) or GABA (0.2 mM). It could be shown that consumption of [U‐13C]glutamate was decreased in the presence of glutamine and release of labeled aspartate and [1,2,3‐13C]glutamate decreased as well, whereas the concentrations of these metabolites increased inside the cells. Glutamine decreased energy production from [U‐13C]glutamate presumably by substituting for glutamate as an energy substrate. No additional effect was seen in the presence of both glutamine and GABA. When cerebellar granule neurons were incubated with [U‐13C]glutamate (0.25 mM) and GABA (0.05 mM), less [U‐13C]glutamate was used for energy production than in controls. Because the barbiturate thiopental did not elicit such response (Qu et al., 2000, Neurochem Int 37:207–215) it appears that GABA also has a metabolic function in the glutamatergic cerebellar granule neurons in contrast to the astrocytes. © 2001 Wiley‐Liss, Inc.
Lectin‐induced apoptosis of mature olfactory receptor cells
Authors: Moon Young Wha , Baker Harriet
Published: August 2002

Previous studies showed that uptake of the lectin conjugate, wheat germ agglutinin‐horseradish peroxidase (WGA‐HRP) by olfactory receptor cells results in a thinning of the olfactory epithelium (OE) and increased turnover of globose basal cells. To ascertain the cell‐type lost as well as the time course and mechanism of the loss, the current study measured changes in the number of dendritic knobs, olfactory marker protein (OMP) expression and assessed TUNEL labeling as an indicator of apoptosis. Electron microscopic analysis of the number of dendritic knobs showed that the largest reduction occurred at 1 week after intranasal irrigation with WGA‐HRP. This data in conjunction with decreased OMP staining provided evidence for a loss of mature receptor neurons. TUNEL labeling, especially in more superficial aspects of the OE, peaked at 18 hr after WGA‐HRP application suggesting that the lectin‐conjugate produced a rapid induction of apoptotic cell death that was complete by 3 days. Measurement of tyrosine hydroxylase (TH) activity in the olfactory bulb, a sensitive measure of deafferentation, showed that innervation reached a nadir at about 1 week and that reinnervation was complete by 4 weeks. These findings demonstrate that internalization of WGA‐HRP by some receptor cells results in their death by apoptosis and a subsequent deafferentation of the olfactory bulb. © 2002 Wiley‐Liss, Inc.