bluuebunny/crossref_metadata_2025 huggingface dataset:
Contact laser‐assisted neuroendoscopy can be performed safely by using pretreated ‘black’ fibre tips: Experimental data
Authors: Willems Peter W.A. , Vandertop W. Peter , Verdaasdonk Rudolf M. , van Swol Christiaan F.P. , Jansen Gerard H.
Published: August 2002

Background and Objective

Laser‐assisted endoscopic neurosurgery by using conventional fibres requires the use of high‐power laser light. Because this is potentially hazardous, we developed a pretreated fibre tip and evaluated tissue effects in vitro and in vivo.

Study Design/Materials and Methods

By applying a highly absorbing coating to the front of the ball tip, almost all laser light is transformed into thermal energy, instantly producing ablative temperatures at the tip itself. The temperature distribution was examined by using an in vitro thermal imaging technique. The in vivo effect on rabbit cerebral tissue was examined macroscopically and histologically.

Results

By using a conventional fibre tip, ablation was not observed, despite the use of high energy and power (20 W for 10 seconds), whereas histology and thermal imaging demonstrated deleterious effects deeply into the cerebral tissue. By using the coated fibre tip, ablation was observed at low energy and power (1 W for 1 second) with thermal effects restricted to superficial structures.

Conclusions

We show that laser‐assisted neuroendoscopy can only be considered to be safe when pretreated “black” fibre tips are used, as laser light damages deep structures. Lasers Surg. Med. 28:324–329, 2001. © 2001 Wiley‐Liss, Inc.
Permeabilization and recovery of the stratum corneum in vivo: The synergy of photomechanical waves and sodium lauryl sulfate
Authors: Lee Shun , McAuliffe Daniel J. , Kollias Nikiforos , Flotte Thomas J. , Doukas Apostolos G.
Published: August 2002

Background and Objective:

Photomechanical waves render the stratum corneum permeable and allow macromolecules to diffuse into the epidermis and dermis. The aim of this study was to investigate the combined action of photomechanical waves and sodium lauryl sulfate, an anionic surfactant, for transdermal delivery.

Study Design/Materials and Methods:

A single photomechanical wave was applied to the skin of rats in the presence of sodium lauryl sulfate. The sodium lauryl sulfate solution was removed and aqueous solutions of rhodamine‐B dextran (40 kDa molecular weight) were applied to the skin at time points 2, 30, and 60 minutes post‐exposure. The presence of rhodamine‐B dextran in the skin was measured by fluorescence emission spectroscopy in vivo and fluorescence microscopy of frozen biopsies.

Results:

The use of sodium lauryl sulfate delayed the recovery of the stratum corneum barrier and extended the time available for the diffusion of dextran through it.

Conclusion:

The combination of photomechanical waves and surfactants can enhance transdermal drug delivery. Lasers Surg. Med. 29:145–150, 2001. © 2001 Wiley‐Liss, Inc.
In vivo laser‐induced interstitial thermotherapy of pig liver with a temperature‐controlled diode laser and MRI correlation
Authors: Wohlgemuth Walter A. , Wamser Günther , Reiss Thomas , Wagner Theodor , Bohndorf Klaus
Published: August 2002

Background and Objective

To evaluate the efficacy of a new temperature‐controlled Diode laser to generate in vivo tissue coagulations with laser‐induced interstitial thermotherapy (LITT) in pig liver and MRI‐correlation of these necroses.

Study Design/Materials and Methods

Each of four animal subjects received eight treatments at four different constant temperatures (70, 80, 90, and 100°C) and at two out of three different intervals (3, 6, 9 minutes), resulting in a total of 32 lesions. After sacrificing, the liver was examined in an open MRI (0.35T). Tissue necrosis was measured macroscopically and compared with the size measured by MRI.

Results

The size of the necrosis was energy dependent with the largest extent at 100°C at 9 minutes (2.1 cm). The correlation between macroscopic lesion size and MRI findings was significant (P > 0.036). Histological workup excluded carbonization in every case.

Conclusions

LITT carried out with the Diode laser provides reproducible necroses of pig liver in vivo. MR‐imaging results compared favorably with those obtained by pathologic specimens. Lasers Surg. Med. 29:374–378, 2001. © 2001 Wiley‐Liss, Inc.
Children's relationships with brands: “True love” or “one‐night” stand?
Authors: Ji Mindy F.
Published: August 2002

Group and individual interviews were conducted to examine relationships developed between children and brands in the family setting. Children's stories about brands suggest that they develop relationships with a wide range of brands and these relationships are imbedded in the social environment where children live and grow. Interpersonal relationship metaphors were utilized to describe different forms of child–brand relationships. The article concludes that children's relationships with brands serve important functions in their lives and have significant implications for marketers. © 2002 Wiley Periodicals, Inc.
Gene expression analysis of prostate cancers
Authors: Luo Jian‐Hua , Yu Yan Ping , Cieply Kathleen , Lin Fan , Deflavia Petrina , Dhir Rajiv , Finkelstein Sydney , Michalopoulos George , Becich Michael
Published: August 2002

Prostate cancer is a biologically heterogeneous disease with considerable variation in clinical aggressiveness. The behavior of prostate cancer can be considered a direct or indirect result of aberrant alterations of gene expression in prostate epithelial cells. Identification of the patterns of gene‐expression alterations that are related to the aggressiveness of prostate cancers will greatly assist the development of tools for early detection of prostate cancers with poor clinical outcome and identification of targets for future therapeutic intervention. To detect the patterns of gene‐expression alterations of prostate cancers, we performed a comprehensive gene‐expression analysis on 30 prostate tissues of various levels of invasiveness (ranging from those confined to the organ to distant metastases) and Gleason grades (combined scores 4–9), using the Affymetrix chip set Hu35k (A–D) and U95a. Following three sequential selection screens, we identified 84 largely novel genes and expressed sequence tag (EST) sequences whose expression levels were altered significantly in prostate cancer samples compared with control normal tissues. In addition, the expression levels of a group of 12 genes and EST sequences was found to be altered significantly in aggressive type of prostate cancers but not in organ‐confined prostate cancers. Cluster analysis using the 84‐gene list showed that the highly aggressive prostate cancers contained gene‐expression patterns that were distinct from organ‐confined prostate cancers. © 2002 Wiley‐Liss, Inc.
Suppression of cell transformation and induction of apoptosis by caffeic acid phenethyl ester
Authors: Nomura Masaaki , Kaji Akira , Ma Wei‐ya , Miyamoto Ken‐ichi , Dong Zigang
Published: August 2002

Caffeic acid phenethyl ester (CAPE), which is derived from the propolis of honeybee hives, has been shown to block tumor promotion and to have toxic effects on several cancer cells. The mechanism of the anti–tumor promotion activity of CAPE is unclear, however. In this study, we found that CAPE suppressed 12‐O‐tetradecanoylphorbol‐13‐acetate–induced cell transformation and induced apoptosis in mouse epidermal JB6 Cl 41 cells. No difference in induction of apoptosis was observed between normal lymphoblasts and sphingomyelinase‐deficient cell lines. Although CAPE treatment of two p53 mutant tumor cell lines, NCI‐H358 and SK‐OV‐3, and p53‐deficient (p53−/−) cells caused the cleavage of caspase‐3 as well as DNA fragmentation, caspase‐3 cleavage was seen early (at 6 h) only in cells expressing wild‐type p53 (p53+/+) and Cl 41 cells. These results suggested that p53 may be involved in the early stage of CAPE‐induced apoptosis. The p53‐dependent transcription activation occurred 2 h after treatment with CAPE and reached a maximum at 6 h in Cl 41 p53 DNA‐binding sequence stable transfectant cells. In addition, phosphorylation of p53 at serine 15 and serine 392 was induced in Cl 41 cells within 6 h after treatment with CAPE. Therefore, CAPE may induce apoptosis through p53‐dependent and p53‐independent pathways and its anti–tumor promotion activity may have occurred through the induction of apoptosis. © 2001 Wiley‐Liss, Inc.
The effect of ESOP adoptions on corporate performance: are there really performance changes?
Authors: Pugh William N. , Oswald Sharon L. , Jahera Jr. John S.
Published: August 2002

Employee Stock Ownership Programs (ESOPs) have long been promoted as a motivational tool: employees become profit‐minded owners. Latterly, however, more ESOPs are being used as part of a takeover defense: here the ESOPs main purpose is to put more company stock in friendly hands—the employees—who, like existing management, could suffer layoffs, etc. in a hostile takeover. We find that, as a group, only the takeover‐related ESOPs are associated with increased leverage (itself a takeover defense). Non‐target firms show no long‐term increase in debt‐to‐assets. We find little evidence to support the motivation hypothesis: while actual labor costs are lower for ESOP firms, after industry‐adjusting they tend to be unaffected or higher. We find that a few measures of firm financial performance [return‐on‐equity (ROE), return‐on‐assets (ROA), net profit margin (NPM)] do improve significantly, but this appears to be largely a short‐term effect. Industry‐adjusted holding period returns appear to be unaffected by the ESOP; however, ESOP firms that leverage show evidence of long‐term market underperformance. We conclude that ESOPs provide, at best, only a short‐term boost to corporate performance. Copyright © 2000 John Wiley & Sons, Ltd.
Exacerbated physical fatigue and mental fatigue in Parkinson's disease
Authors: Lou Jau‐Shin , Kearns Greg , Oken Barry , Sexton Gary , Nutt John
Published: August 2002

OBJECTIVE:

To characterize fatigue in Parkinson's disease (PD).

BACKGROUND:

Fatigue is a recognized problem in PD. Fatigue can be in the physical realm or in the mental realm. Fatigue has not been characterized in PD.

METHODS:

We characterized fatigue in 39 PD patients and 32 age‐matched normal controls using five questionnaires: A. The Multidimensional Fatigue Inventory (MFI), which measures five dimensions of fatigue independently including general fatigue, physical fatigue, reduced motivation, reduced activity, and mental fatigue. B. The Fatigue Severity Inventory (FSI), which quantifies fatigue in general. C. The Profile of Mood States (POMS), which assesses six subjective subscales: tension‐anxiety, depression‐dejection, anger‐hostility, fatigue‐inertia, vigor‐activity, and confusion‐bewilderment. D. Center for Epidemiological Studies‐Depression Scale (CES‐D). E. Visual Analog linear scale of energy (VA‐E).

RESULTS:

PD patients scored higher in all of the five dimensions of fatigue in the MFI including general fatigue, physical fatigue, reduced motivation, reduced activity, and mental fatigue (P < 0.001 except for mental fatigue P = 0.005). The severity of physical fatigue did not correlate with that of mental fatigue. PD patients scored higher on the FSI, POMS, CES‐D, and scored lower on the VA‐E. The scores in the FSI correlated with general fatigue, physical fatigue, reduced activity, and reduced motivation but not with mental fatigue in the MFI. Depression correlated with all dimensions of fatigue except physical fatigue in the MFI. Disease severity, as measured by Modified Hoehn and Yahr staging, did not correlate with any of the measures.

CONCLUSIONS:

PD patients have increased physical fatigue and mental fatigue compared to normals. Physical fatigue and mental fatigue are independent symptoms in PD that need to be assessed and treated separately. © 2001 Movement Disorder Society.
Open interconnected model of basal ganglia‐thalamocortical circuitry and its relevance to the clinical syndrome of Huntington's disease
Authors: Joel D.
Published: August 2002

The early stages of Huntington's disease (HD) present with motor, cognitive, and emotional symptoms. Correspondingly, current models implicate dysfunction of the motor, associative, and limbic basal ganglia‐thalamocortical circuits. Available data, however, indicate that in the early stages of the disease, striatal damage is mainly restricted to the associative striatum. Based on an open interconnected model of basal ganglia‐thalamocortical organization, we provide a detailed account of the mechanisms by which associative striatal pathology may lead to the complex pattern of motor, cognitive, and emotional symptoms of early HD. According to this account, the degeneration of a direct and several indirect pathways arising from the associative striatum leads to impaired functioning of: (1) the motor circuit, resulting in chorea and bradykinesia, (2) the associative circuit, resulting in abnormal eye movements, “frontal‐like” cognitive deficits and “cognitive disinhibition,” and (3) the limbic circuit, resulting in affective and psychiatric symptoms. When relevant, this analysis is aided by comparing the symptomatology of HD patients to that of patients with mild to moderate Parkinson's disease, since in the latter there is similar dysfunction of direct pathways but opposite dysfunction of indirect pathways. Finally, we suggest a potential novel treatment of HD and provide supportive evidence from a rat model of the disease. © 2001 Movement Disorder Society.
Effects of follicular size of cytoplast donor on the efficiency of cloning in cattle
Authors: Piedrahita Jorge A. , Wells D.N. , Miller A.L. , Oliver J.E. , Berg M.C. , Peterson A.J. , Tervit H.R.
Published: August 2002

In cattle, oocytes obtained from follicles smaller than 3 mm in diameter can undergo maturation in vitro, progressing to MII and undergoing fertilization, but are developmentally incompetent. Cytoplasts were prepared from in vitro matured oocytes aspirated from small (1–3 mm) or large (6–12 mm) follicles and fused to serum starved mural granulosa cells. Following activation, reconstructed embryos were cultured for 7 days and classified G1 to G4, before being processed for nuclei counting or transferred to synchronized recipients. Oocytes from small follicles had lower rates of polar body extrusion (59.6 vs. 69%; 731/1230 vs. 608/857) and fusion (71.4 vs. 78.8%; 360/497 vs. 364/465; P < 0.06). There were no differences in total rate of blastocysts development (60 vs. 59.8%; small vs. large), or any grade classification. A significant interaction was detected between follicle size and embryo grade with G3 embryos from small follicles having a greater cell number. Developmental competence of G1 and G2 embryos did not differ at day 27 (48 vs. 46%; 16/33 vs. 17/37; small vs. large). Although there were no differences in fetal size between the two groups, differences in allantois length (53 vs. 86 mm; small vs. large; P < 0.002) and allantois width (9.5 vs. 13 mm; small vs. large; P < 0.06) were seen. No differences in survival to term (2/13 in each group) were observed. These results indicate that cytoplasts from follicles of 1–3 and 6–12 mm in diameter are equally developmentally competent when used in a nuclear transfer procedure. Mol. Reprod. Dev. 61: 317–326, 2002. © 2002 Wiley‐Liss, Inc.
Germ cell specific promoter drives ectopic transgene expression during embryogenesis
Authors: Bhullar Bhupinder , Schmidt Jennifer V. , Truong Tony , Rancourt Derrick , van der Hoorn Frans A.
Published: August 2002

In this study, we used the male germ cell‐specific phosphoglycerate kinase 2 (Pgk2) promoter to generate Pgk2Cre transgenic mice to allow investigation of genes critically involved in meiosis. The Pgk2 promoter had been used previously to target transgene expression to spermatocytes and spermatids in several laboratories including ours. In several Cre targeting experiments using other promoters, ectopic Cre expression had been observed, but the timing and extent of this expression was not analyzed. We demonstrate that in adult mice the Pgk2Cre transgene is expressed specifically in spermatocytes and spermatids, as expected. However, in offspring from matings of Pgk2Cre mice and an H19loxP indicator strain, we discovered that recombination events had occurred in several, but not all, tissues to varying extents. The lacZ‐loxP transgenic indicator strain was next used to uncover ectopic Cre expression even in single cells, which indicated that the Pgk2Cre transgene is expressed between days 11 and 15 during embryogenesis in several tissues and organs. Using an RT PCR assay we were unable to detect endogenous Pgk2 mRNA during embryogenesis or in adult tissues other than testis. In conclusion, the Pgk2 promoter is a valid choice for targeting gene expression to meiotic male germ cells, since transient ectopic expression is unlikely to have a discernable effect in most studies, but it may be inappropriate for utilization with Cre recombinase. Mol. Reprod. Dev. 59:25–32, 2001. © 2001 Wiley‐Liss, Inc.
Exzzpression and localization of angiogenin in placenta: Enhanced levels at term over first trimester villi
Authors: Rajashekhar G. , Loganath A. , Roy A.C. , Wong Y.C.
Published: August 2002

Human angiogenin, a 14‐kDa non‐glycosylated polypeptide with both angiogenic and ribonucleolytic activities, is implicated in angiogenesis, a complex process of proliferation and formation of new capillary blood vessels from existing blood vessels. Placental growth requires extensive angiogenesis, which develops its vascular structure in both fetal chorionic villi and maternal deciduas. In this study, we investigated the expression profiles of angiogenin in placental villi from early and late gestation at both mRNA and protein levels using explant cultures in vitro followed by RT‐PCR, immunoblot, and immunohistochemical analyses. From functionally active placental explants, angiogenin was detected in conditioned media of all the samples from first trimester and term group. The mean levels of angiogenin produced by term villi were found to be 2.6‐, 2.1‐, and 2.2‐fold higher (P < 0.01) than first trimester villi at 24, 48, and 72 hr of culture, respectively. Expression profiles of angiogenin from term and first trimester villi seem to agree with its mRNA levels and immunoblot analysis; the expression in term villi was twice that in first trimester villi. The presence of angiogenin in placental villi and upregulation of its production towards term indicate that angiogenin production by the placenta is specific to the developmental stage. In conclusion, the observed changes in the localization and mRNA expression of angiogenin during placental development raise the possibility that it is involved in morphological and angiogenic changes in this endocrine organ vital to the successful fetal outcome during pregnancy. Mol. Reprod. Dev. 62: 159–166, 2002. © 2002 Wiley‐Liss, Inc.
Induced thermotolerance in bovine two‐cell embryos and the role of heat shock protein 70 in embryonic development
Authors: Al‐Katanani Y.M. , Hansen P.J.
Published: August 2002

Induced thermotolerance is a phenomenon whereby exposure to a mild heat shock can induce heat shock proteins (HSP) and other cellular changes to make cells more resistant to a subsequent, more severe heat shock. Given that the 2‐cell bovine embryo is very sensitive to heat shock, but can also produce HSP70 in response to elevated temperature, experiments were conducted to test whether 2‐cell embryos could be made to undergo induced thermotolerance. Another objective was to test the role of the heat‐inducible form of heat shock protein 70 (HSP70i) in development and sensitivity of bovine embryos to heat shock. To test for induced thermotolerance, 2‐cell bovine embryos were first exposed to a mild heat shock (40°C for 1 hr, or 41°C or 42°C for 80 min), allowed to recover at 38.5°C and 5% (v/v) CO2 for 2 hr, and then exposed to a severe heat shock (41°C for 4.5, 6, or 12 hr). Regardless of the conditions, previous exposure to mild heat shock did not reduce the deleterious effect of heat shock on development of embryos to the blastocyst stage. The role of HSP70i in embryonic development was tested in two experiments by culturing embryos with a monoclonal antibody to the inducible form of HSP70. At both 38.5°C and 41°C, the proportion of 2‐cell embryos that developed to blastocyst was reduced (P < 0.05) by addition of anti‐HSP70i to the culture medium. In contrast, sensitivity to heat shock was not generally increased by addition of antibody. In conclusion, bovine 2‐cell embryos appear incapable of induced thermotolerance. Lack of capacity for induced thermotolerance could explain in part the increased sensitivity of 2‐cell embryos to heat shock as compared to embryos at later stages of development. Results also implicate a role for HSP70i in normal development of bovine embryos. Mol. Reprod. Dev. 62: 174–180, 2002. © 2002 Wiley‐Liss, Inc.
Nuclear maturation of canine oocytes cultured in protein‐free media
Authors: Songsasen N. , Yu I. , Leibo S.P.
Published: August 2002

The objective of this study was to determine the ability of canine oocytes to complete nuclear maturation in a protein‐free medium. Oocytes obtained from ovaries of bitches aged 6 months to 2 years were cultured either in TCM199 or CMRL1066 medium without protein supplementation in 5% or 20% O2. Sixteen of 121 (13%) oocytes cultured in TCM199 reached metaphase II, but only 1 of 135 oocytes cultured in CMRL1066 did so (P < 0.05). Oxygen concentration did not affect nuclear maturation. An additional 103 oocytes were cultured in TCM199 for 48 hr, inseminated with chilled ejaculated spermatozoa, fixed in 1:3 acetic acid–ethanol and then stained with aceto‐orcein; 34% of these oocytes were penetrated by spermatozoa. To determine developmental competence of oocytes cultured in a protein‐free medium, 85 oocytes were cultured in TCM 199 for 48 hr, inseminated and then cultured; 7 early stage embryos were produced. The effects of growth hormone, β‐mercaptoethanol (βME), luteinizing hormone (LH) and energy substrates, alone or in combination, on nuclear maturation of oocytes cultured in a protein‐free medium were also determined. Growth hormone enhanced cumulus expansion, but did not improve nuclear maturation. β‐mercaptoethanol had no effect on nuclear maturation. However, percentages of MII oocytes significantly decreased when the oocytes were cultured for 48 hr in the medium containing LH or a high concentration of glucose (P < 0.05). In conclusion, canine oocytes are able to complete nuclear maturation in a protein‐free medium. The specific type of medium and other supplements significantly influence the meiotic maturation of canine oocytes. Mol. Reprod. Dev. 62: 407–415, 2002. © 2002 Wiley‐Liss, Inc.
Developmental, qualitative, and ultrastructural differences between ovine and bovine embryos produced in vivo or in vitro
Authors: Rizos Dimitrios , Fair Trudee , Papadopoulos Serafeim , Boland Maurice P. , Lonergan Patrick
Published: August 2002

The objective of this study was to compare bovine and ovine oocytes in terms of (1) developmental rates following maturation, fertilization, and culture in vitro, (2) the quality of blastocysts produced in vitro, assessed in terms of their ability to undergo cryopreservation, and (3) the ultrastructural morphology of these blastocysts. In vitro blastocysts were produced following oocyte maturation/fertilization and culture of presumptive zygotes in synthetic oviduct fluid. In vivo blastocysts were used as a control from both species. In Experiment 1, the cleavage rate of bovine oocytes was significantly higher than that of ovine oocytes (78.3% vs. 58.0%, respectively, P < 0.001). The overall blastocyst yield was similar for both species (28.7% vs. 29.0%). However, when corrected for cleavage rate, significantly more ovine oocytes reached the blastocyst stage at all time‐points (36.6% vs. 50.0% on day 8, for bovine and ovine, respectively, P < 0.001). Following vitrification, there was no difference in survival between in vivo produced bovine and ovine blastocysts (72 hr: 85.7% vs. 75.0%). However, IVP ovine blastocysts survived at significantly higher rates than IVP bovine blastocysts at all time points (72 hr: 47.4% vs. 18.1%, P < 0.001). At the ultrastructural level, compared with their in vivo counterparts, IVP blastocysts were characterized by a lack of desmosomal junctions, a reduction in the microvilli population, an increase in the average number of lipid droplets and increased debris in the perivitelline space and intercellular cavities. These differences were more marked in bovine IVP blastocysts, which also displayed electron‐lucent mitochondria and large intercellular cavities. These observations may in part explain the species differences observed in terms of cryotolerance. In conclusion, the quality of ovine blastocysts was significantly higher than their bovine counterparts produced under identical in vitro conditions suggesting inherent species differences between these two groups affecting embryo quality. Mol. Reprod. Dev. 62: 320–327, 2002. © 2002 Wiley‐Liss, Inc.
Hyperglycemia‐induced apoptotic cell death in the mouse blastocyst is dependent on expression of p53
Authors: Keim April L. , Chi Maggie M.‐Y. , Moley Kelle H.
Published: August 2002

Murine preimplantation embryos exposed to hyperglycemia experience decreased glucose transport, and overexpression of the proapoptotic protein BAX, leading to increased apoptosis. These changes may account for the increased rates of miscarriages and malformations seen in women with diabetes mellitus. To test whether p53 expression is necessary for hyperglycemia‐induced apoptosis, p53+/+, +/−, −/− embryos were obtained by superovulation. Two‐cell embryos were cultured to a blastocyst stage in 52 mM d‐ or l‐glucose. Apoptosis was detected using terminal dUTP nick end labeling (TUNEL) assays. In vivo studies were performed in the same manner using blastocysts recovered from streptozotocin‐induced diabetic mothers. Both in vitro and in vivo studies showed that wildtype embryos had a significantly higher percentage of TUNEL‐positive nuclei than p53+/− and −/− embryos. To test whether p53 is upstream of BAX, immunofluorescent confocal microscopy and immunoprecipitation/ immunoblotting were performed on blastocysts cultured in high vs. control glucose conditions. Blastocysts from p53+/+ mice exhibited increased BAX staining vs. p53+/− and −/− embryos. Next, to determine whether a decrease in glucose transport was upstream or downstream of p53, deoxyglucose transport was measured in individual blastocysts from p53+/+ and +/− diabetic vs. nondiabetic mice. Embryos from diabetic p53+/− mice exhibit a 44% decrease in glucose transport, similar to the 38% decrease seen in embryos from diabetic p53+/+ mice. Taken together, these results strongly indicate that p53 plays a role in hyperglycemia‐induced apoptosis, upstream of BAX overexpression and downstream of the decrease in glucose transport experienced by the mouse preimplantation embryo. Mol. Reprod. Dev. 60: 214–224, 2001. © 2001 Wiley‐Liss, Inc.
Control and expression of cystatin C by mouse decidual cultures
Authors: Afonso Suzanne , Tovar Chris , Romagnano Linda , Babiarz Bruce
Published: August 2002

During mouse embryo implantation, trophoblast invasion is controlled in part by a balance of trophoblast‐derived proteinases and uterine decidual proteinase inhibitors. Our work has focused on cystatin C, the secreted inhibitor of cathepsins B and L. We have previously shown that cystatin C is synthesized by the uterine decidua and localized to the cells in close contact with the trophoblast during implantation in vivo. In the work reported here we have established that decidualizing cultures show a similar upregulation of cystatin C. Using Northern and Western blotting and immunolocalization techniques both cystatin C mRNA and secreted protein increased with the morphological differentiation of stromal or decidual capsule cultures. In an effort to understand the regulation of cystatin C expression, decidual cells were analyzed under various culture conditions. Cystatin C expression was upregulated by increased cell density and by the presence of serum in the media. The growth factors TGF‐β1 and EGF were found to induce cystatin C to levels comparable to serum stimulation. Co‐culture with ectoplacental cones (EPCs) likewise induced expression and resulted in the localization of cystatin at the decidua:trophoblast interface. This work shows that decidualizing cultures are a good system to study cystatin C expression and that the expression is controlled in part by TGF‐β1 and EGF signaling. Mol. Reprod. Dev. 61: 155–163, 2002. © 2002 Wiley‐Liss, Inc.
Disorders of glutamate metabolism
Authors: Kelly Andrea , Stanley Charles A.
Published: August 2002

The significant role the amino acid glutamate assumes in a number of fundamental metabolic pathways is becoming better understood. As a central junction for interchange of amino nitrogen, glutamate facilitates both amino acid synthesis and degradation. In the liver, glutamate is the terminus for release of ammonia from amino acids, and the intrahepatic concentration of glutamate modulates the rate of ammonia detoxification into urea. In pancreatic β‐cells, oxidation of glutamate mediates amino acid‐stimulated insulin secretion. In the central nervous system, glutamate serves as an excitatory neurotransmittor. Glutamate is also the precursor of the inhibitory neurotransmittor GABA, as well as glutamine, a potential mediator of hyperammonemic neurotoxicity. The recent identification of a novel form of congenital hyperinsulinism associated with asymptomatic hyperammonemia assigns glutamate oxidation by glutamate dehydrogenase a more important role than previously recognized in β‐cell insulin secretion and hepatic and CNS ammonia detoxification. Disruptions of glutamate metabolism have been implicated in other clinical disorders, such as pyridoxine‐dependent seizures, confirming the importance of intact glutamate metabolism. This article will review glutamate metabolism and clinical disorders associated with disrupted glutamate metabolism. MRDD Research Reviews 2001;7:287–295. © 2001 Wiley‐Liss, Inc.
Multifunctional interventional devices for MRI: A combined electrophysiology/MRI catheter
Authors: Susil Robert C. , Yeung Christopher J. , Halperin Henry R. , Lardo Albert C. , Atalar Ergin
Published: August 2002

The design and application of a two‐wire electrophysiology (EP) catheter that simultaneously records the intracardiac electrogram and receives the MR signal for active catheter tracking is described. The catheter acts as a long loop receiver, allowing for visualization of the entire catheter length while simultaneously behaving as a traditional two‐wire EP catheter, allowing for intracardiac electrogram recording and ablation. The application of the device is demonstrated by simultaneously tracking the catheter and recording the intracardiac electrogram in canine models using 7 and 10 frame/sec real‐time imaging sequences. Using solely MR imaging, the entire catheter was visualized and guided from the jugular vein into the cardiac chambers, where the intracardiac electrogram was recorded. By combining several functions in a single, simple structure, the excellent tissue contrast and functional imaging capabilities of MR can be used to improve the efficacy of EP interventions. This catheter will facilitate MR‐guided interventions and demonstrates the design of multifunctional interventional devices for use in MRI. Magn Reson Med 47:594–600, 2002. © 2002 Wiley‐Liss, Inc.
Rapid T1 mapping using multislice echo planar imaging
Authors: Clare Stuart , Jezzard Peter
Published: August 2002

Determination of neurological pathology in white matter disease can be made in a semiquantitative way from T1‐ or T2‐weighted images. A higher level of quantification based on measured T1 or T2 values has been either limited to specific regions of interest or to low‐resolution maps. Higher‐resolution T1 maps have proved difficult to obtain due to the excessively long scan times required using conventional techniques. In this study, clinically acceptable images are obtained by using single‐shot echo planar imaging (EPI) with an acquisition scheme that maximizes signal‐to‐noise while minimizing the scan time. Magn Reson Med 45:630–634, 2001. © 2001 Wiley‐Liss, Inc.
Parahydrogen‐induced polarization in imaging: Subsecond 13C angiography
Authors: Golman K. , Axelsson O. , Jóhannesson H. , Månsson S. , Olofsson C. , Petersson J.S.
Published: August 2002

High nuclear spin polarization of 13C was reached in organic molecules. Enhancements of up to 104, compared to thermal polarization at 1.5 T, were achieved using the parahydrogen‐induced polarization technique in combination with a field cycling method. While parahydrogen has no net polarization, it has a high spin order, which is retained when hydrogen is incorporated into another molecule by a chemical reaction. By subjecting this molecule to a sudden change of the external magnetic field, the spin order is transferred into net polarization. A 13C angiogram of an animal was generated in less than a second. Magn Reson Med 46:1–5, 2001. © 2001 Wiley‐Liss, Inc.
A serial MR study of cerebral blood flow changes and lesion development following endothelin‐1‐induced ischemia in rats
Authors: Biernaskie Jeff , Corbett Dale , Peeling James , Wells Jennifer , Lei Hao
Published: August 2002

The vasoconstrictive peptide endothelin‐1 (ET‐1) has been used previously to transiently occlude the middle cerebral artery (MCA) in rats. However, the duration of the resulting reduction in cerebral blood flow (CBF) and the reperfusion characteristics are poorly understood. In this study perfusion and T2‐weighted MRI were used together with histology to characterize the cerebral perfusion dynamics and lesion development following ET‐1 injection. Twenty‐two rats received an intracerebral injection of ET‐1 adjacent to the MCA. CBF was reduced to 30–50% of control levels, and a significant reduction persisted for 16 h in the cortex and 7 h in the striatum. The lesion size measured by T2‐weighted imaging at 48 h correlated with the final infarct size measured by histology at 7 d. The sustained reduction in CBF and the gradual development of the ischemic lesion resemble human stroke evolution, suggesting that this model may be useful for evaluating therapeutic agents, particularly when treatment is delayed. Magn Reson Med 46:827–830, 2001. © 2001 Wiley‐Liss, Inc.
Dualband spectral‐spatial RF pulses for prostate MR spectroscopic imaging
Authors: Schricker Amir A. , Pauly John M. , Kurhanewicz John , Swanson Mark G. , Vigneron Daniel B.
Published: August 2002

Although MR spectroscopic imaging (MRSI) of the prostate has demonstrated clinical utility for the staging and monitoring of cancer extent, current acquisition methods are often inadequate in several aspects. Conventional 180° pulses can suffer from chemical shift misregistration, and have high peak‐power requirements that can exceed hardware limits in many prostate MRSI studies. Optimal water and lipid suppression are also critical to obtain interpretable spectra. While complete suppression of the periprostatic lipid resonance is desired, controlled partial suppression of water can provide a valuable phase and frequency reference for data analysis and an assessment of experimental success in cases in which all other resonances are undetectable following treatment. In this study, new spectral‐spatial RF pulses were developed to negate chemical shift misregistration errors and to provide dualband excitation with partial excitation of the water resonance and full excitation of the metabolites of interest. Optimal phase modulation was also included in the pulse design to provide 40% reduction in peak RF power. Patient studies using the new pulses demonstrated both feasibility and clear benefits in the reliability and applicability of prostate cancer MRSI. Magn Reson Med 46:1079–1087, 2001. © 2001 Wiley‐Liss, Inc.
Noninvasive quantification of total sodium concentrations in acute reperfused myocardial infarction using 23Na MRI
Authors: Constantinides Chris D. , Kraitchman D.L. , O'Brien K.O. , Boada F.E. , Gillen J. , Bottomley Paul A.
Published: August 2002

The transport of sodium and potassium between the intra‐ and extracellular pools and the maintenance of the transmembrane concentration gradients are important to cell function and integrity. The early disruption of the sodium pump in myocardial infarction in response to the exhaustion of energy reserves following ischemia and reperfusion results in increased intracellular (and thus total) sodium levels. In this study a method for noninvasively quantifying myocardial sodium levels directly from sodium (23Na) MRI is presented. It was used to measure total myocardial sodium on a clinical 1.5T system in six normal dogs and five dogs with experimentally‐induced myocardial infarction (MI). The technique was validated by comparing total sodium content measured by 23Na MRI with that measured by atomic absorption spectrophotometry (AAS) in biopsied tissue. Total sodium measured by 23Na MRI was significantly elevated in regions of infarction (81.3 ± 14.3 mmol/kg wet wt, mean ± SD) compared to noninfarcted myocardial tissue from both infarcted dogs (36.2 ± 1.1, P < 0.001) and from normal controls (34.4 ± 2.8, P < 0.0001). Myocardial tissue sodium content as measured by 23Na MRI did not vary regionally in the lateral, anterior, or inferior regions in normal hearts (ANOVA, P = NS). Sodium content measured by 23Na MRI agreed with the mean AAS estimates of 31.3 ± 5.6 mmol/kg wet wt (P = NS) in normal hearts, and did not differ significantly from AAS measurements in MI (P = NS). Thus, local tissue sodium levels can be accurately quantified noninvasively using 23Na MRI in normal and acutely reperfused MI. The detection of regional myocardial sodium elevations may help differentiate viable from nonviable, infarcted tissue. Magn Reson Med 46:1144–1151, 2001. © 2001 Wiley‐Liss, Inc.
Delay in initiation and termination of muscle contraction, motor impairment, and physical disability in upper limb hemiparesis
Authors: Chae John , Yang Guang , Park Byung Kyu , Labatia Ihab
Published: August 2002

The purpose of this study was to describe the relationship between the delay in initiation and termination of muscle contraction and clinical measures of motor impairment and physical disability in the affected upper limb of patients with hemiparesis. Electromyographic (EMG) activity of 26 long‐term survivors of stroke was recorded during isometric wrist flexion and extension. Upper limb motor impairment and disability were assessed with the Fugl‐Meyer motor assessment (FMA) and arm motor ability test (AMAT), respectively. Delay in initiation and termination of muscle contraction was significantly prolonged in the paretic arm. However, the delay was not significantly affected by stroke type, stroke level, side of hemiparesis, or presence of aphasia. Delay in initiation and termination of muscle contraction correlated significantly with FMA and AMAT. Abnormally delayed initiation and termination of muscle contraction may contribute to hemiparetic upper limb motor impairment and physical disability in hemiparetic patients. © 2002 Wiley Periodicals, Inc. 25: 000–000, 2002
Treatment experience in patients with anti–myelin‐associated glycoprotein neuropathy
Authors: Gorson Kenneth C. , Ropper Allan H. , Weinberg David H. , Weinstein Robert
Published: August 2002

We report our experience with 24 consecutively treated patients (15 men and 9 women, median age 64 years) with anti–myelin‐associated glycoprotein (anti‐MAG) neuropathy. The rates of response to plasma exchange (40%), immune globulin (16%), and cyclophosphamide‐based therapy (36%) were similar. Five (24%) responded to the first treatment modality, 32% to a second, alternative modality, and 31% to a third. Only 4 of 12 responders had sustained improvement; the others relapsed after a median of 7 months. In those 4 patients, the median immunoglobulin M (IgM) level dropped by 25% compared to an increase of 24% in the nonresponders (P = 0.04). Thus, most patients with anti‐MAG neuropathy failed to have sustained improvement after treatment, and none of the therapies emerged as superior. Disability improved transiently after therapy in approximately 50% of cases. A 25% reduction of the IgM level predicted sustained improvement, but was difficult to achieve. There were no clinical or electrodiagnostic features associated with a treatment response, nor did a reduction of the anti‐MAG antibody titer correlate with clinical improvement. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 778–786, 2001
Brachial plexus involvement as the only expression of hereditary neuropathy with liability to pressure palsies
Authors: Ørstavik Kristin , Skard Heier Mona , Young Peter , Stögbauer Florian
Published: August 2002

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal‐dominant focal neuropathy characterized by recurrent entrapment neuropathies. Single members of families with HNPP and brachial plexus involvement have been reported previously. We describe a family with three affected members and in which the only symptom of entrapment was recurrent brachial plexopathy. The diagnosis of HNPP in this family was confirmed by both neurophysiological methods and DNA analysis. The distinction between HNPP and hereditary neuralgic amyotrophy is discussed. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1093–1096, 2001
Changes in glycolytic network and mitochondrial design in creatine kinase–deficient muscles
Authors: de Groof Ad J. C. , Oerlemans Frank T. J. J. , Jost Carolina R. , Wieringa Bé
Published: August 2002

Skeletal muscles respond with high plasticity to pathobiological conditions or changes in physiological demand by remodeling cytoarchitectural and metabolic characteristics of individual myocytes. We have previously shown that muscles of mice without mitochondrial and/or cytosolic creatine kinases (ScCKmit−/− and/or M‐CK−/−) partly compensate for the defect(s) by redirecting metabolic pathways and ultrastructural characteristics. Here, we show by semiquantitative Western blot analysis that the compensatory changes involve mutation‐ and fiber‐type–specific coordinated regulation of divergent but functionally coupled groups of proteins. Fast‐twitch gastrocnemius muscle of CK−−/−− mice display a two‐ to fourfold upregulation of mitochondrial cytochrome c oxidase, inorganic phosphate carrier, adenine nucleotide translocator, and voltage‐dependent anion channel proteins. In parallel, cytosolic myoglobin is upregulated. Slow‐twitch soleus muscle responds with changes in the glycolytic enzyme pattern, including a shift in lactate dehydrogenase isoenzyme composition. Adaptations in the network for oxidative adenosine triphosphate (ATP) production are already apparent at 17 days of age. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1188–1196, 2001
Magnetic resonance imaging of denervation‐induced muscle atrophy: Effects of clenbuterol in the rat
Authors: Cockman Michael D. , Jones Melissa B. , Prenger Marla C. , Sheldon Russell J.
Published: August 2002

We show that magnetic resonance imaging (MRI) can be used to quantify the amount of muscle in the lower legs of adult rats and to noninvasively monitor the onset and progression of denervation‐induced atrophy. Muscle cross‐sectional areas determined from 2D gradient‐echo MR images allow longitudinal quantification of the protective effects of a β2‐adrenergic agonist clenbuterol. We also show that the estimation of clenbuterol's efficacy is improved by computation of the muscle volume. Rapid animal throughput and the ability to accurately estimate efficacy make MRI an attractive technology for studying skeletal muscle atrophy and hypertrophy, allowing the evaluation of potential therapies in longitudinal studies. © 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 1647–1658, 2001
Load transfer approach for laterally loaded piles
Authors: Guo Wei Dong , Lee F. H.
Published: August 2002

A two‐parameter model has been proposed previously for predicting the response of laterally loaded single piles in homogenous soil. A disadvantage of the model is that at high Poisson's ratio, unreliable results may be obtained. In this paper, a new load transfer approach is developed to simulate the response of laterally loaded single piles embedded in a homogeneous medium, by introducing a rational stress field. The approach can overcome the inherent disadvantage of the two‐parameter model, although developed in a similar way. Generalized solutions for a single pile and the surrounding soil under various pile‐head and base conditions were established and presented in compact forms. With the solutions, a load transfer factor, correlating the displacements of the pile and the soil, was estimated and expressed as a simple equation. Expressions were developed for the modulus of subgrade reaction for a Winkler model as a unique function of the load transfer factor. Simple expressions were developed for estimating critical pile length, maximum bending moment, and the depth at which the maximum moment occurs. All the newly established solutions and/or expressions, using the load transfer factor, offer satisfactory predictions in comparison with the available, more rigorous numerical approaches. The current solutions are applicable to various boundary conditions, and any pile–soil relative stiffness. Copyright © 2001 John Wiley & Sons, Ltd.
Experimental analysis of compaction of concrete and mortar
Authors: Burlion Nicolas , Pijaudier‐Cabot Gilles , Dahan Noël
Published: August 2002

Compaction of concrete is physically a collapse of the material porous microstructure. It produces plastic strains in the material and, at the same time, an increase of its bulk modulus. This paper presents two experimental techniques aimed at obtaining the hydrostatic response of concrete and mortar. The first one is a uniaxial confined compression test which is quite simple to implement and allows to reach hydrostatic pressures of about 600 MPa. The specimen size is large enough so that concrete with aggregate sizes up to 16 mm can be tested. The second one is a true hydrostatic test performed on smaller (mortar) specimens. Test results show that the hydrostatic response of the material is elasto‐plastic with a stiffening effect on both the tangent and unloading bulk moduli. The magnitude of the irreversible volumetric strains depends on the initial porosity of the material. This porosity can be related in a first approximation to the water/cement ratio. A comparison of the hydrostatic responses obtained from the two testing techniques on the same material show that the hydrostatic response of cementitious materials cannot be uncoupled from the deviatoric response, as opposed to the standard assumption in constitutive relations for metal alloys. This feature should be taken into account in the development of constitutive relations for concrete subjected to high confinement pressures which are needed in the modelling of impact problems. Copyright © 2001 John Wiley & Sons, Ltd.
Dynamic interaction between the soil and an anchored sheet pile during seismic excitation
Authors: Degrande G. , Praet E. , Van Zegbroeck B. , Van Marcke P.
Published: August 2002

A subdomain approach for dynamic soil–structure interaction is proposed for the linear elastic seismic analysis of an anchored sheet pile, retaining a horizontally layered soil on rigid bedrock. A hybrid solution technique is used, employing a finite element formulation for the generalized sheet pile, a thin layer formulation for the soil and a direct stiffness formulation for the tieback; the displacement vectors of the sheet pile and the soil are decomposed, using the eigenmodes of the sheet pile and the propagating or decaying modes in the soil. The discretization can be limited to the interface(s), where pointwise continuity of the displacements is enforced, whereas a weak variational formulation is used for the stress equilibrium. The solution technique is illustrated by means of a numerical example, where the harmonic response of a flexible anchored sheet pile is considered and compared to the case where no tieback is present. Copyright © 2002 John Wiley & Sons, Ltd.