bluuebunny/crossref_metadata_2025 huggingface dataset:
Major difference in the expression of δ‐ and μ‐opioid receptors between turtle and rat brain
Authors: Xia Ying , Haddad Gabriel G.
Published: October 2004

The reptilian turtle brain has a remarkably higher endurance for anoxia than mammalian brains. Since the response to O2 deprivation is dependent in a major way on the expression and regulation of membrane proteins, differences in such proteins may play a role in the species‐related differences in hypoxic responses. Because opioid system is involved in the regulation of hypoxic responses, we asked whether there are differences between rat and turtle brains in terms of opioid receptor expression. In this work, we compared the expression and distribution of δ‐and μ‐opioid receptors in the turtle and rat brains. Our results show that (1) the dissociation constant (Kd) for δ‐receptor binding was approximately four times lower and Bmax was more than double in the turtle brain homogenates than in rat ones; (2) the δ‐receptor binding density was heterogeneously distributed in the turtle brain, with a higher density in the rostral regions than in the brainstem and spinal cord, and was generally much higher than in rat brains from the cortex to spinal cord; (3) the δ‐opioid receptors in the rat brains were mostly located in the cortex, caudate putamen, and amygdala with an extremely low density in most subcortical (e.g., hippocampus and thalamus) and almost all brainstem regions; and (4) in sharp contrast to δ‐opioid receptors, μ‐opioid receptor density was much lower in all turtle brain regions compared with the rat ones. Our results demonstrate that the turtle brain is actually an organ of δ‐opioid receptors, whereas the rat brain has predominantly μ‐opioid receptors. Because we have recently found that δ‐opioid receptors protect neurons against glutamate and hypoxic stress, we speculate that the unique pattern of δ‐receptor receptor expression and distribution plays a critical role in the tolerance of turtle brain to stressful situations characterized by glutamate excitotoxicity. J. Comp. Neurol. 436:202–210, 2001. © 2001 Wiley‐Liss, Inc.
Lack of the protein tyrosine phosphatase SHP‐1 results in decreased numbers of glia within the motheaten (me/me) mouse brain
Authors: Wishcamper Celine A. , Coffin J. Douglas , Lurie Diana I.
Published: October 2004

Mice that are homozygous for the autosomal recessive motheaten allele (me/me) lack the protein tyrosine phosphatase SHP‐1. Loss of SHP‐1 leads to many hematopoietic abnormalities, as well as defects such as infertility and low body weight. However, little is known regarding the role SHP‐1 plays in the development of the central nervous system (CNS). To define the role of SHP‐1 in CNS development and differentiation, we examined the brains of me/me mice at various times after birth for neuronal and glial abnormalities. Although the brains of me/me mice are slightly smaller than age‐matched wild‐type littermates, both me/me and wild‐type brains are similar in weight, possess an intact blood‐brain barrier, and have largely normal neuronal architecture. Significantly, the current study reveals that me/me brain shows decreases in the number of glial fibriallary acidic protein (GFAP)+ astrocytes and F480+ microglia compared with wild‐type mice. In addition, decreased immunostaining for the myelin‐synthesizing enzyme CNPase was observed in me/me mice, confirming the loss of myelin in these animals, as reported (Massa et al. [2000] Glia 29:376–385). It is particularly significant that there is a decreased number of immunolabeled glia of all subtypes and that this deficit in glial number is not restricted to a particular class of glia. This suggests that SHP‐1 is necessary for the normal differentiation and distribution of astrocytes, microglia, and oligendrocytes within the murine CNS. J. Comp. Neurol. 441:118–133, 2001. © 2001 Wiley‐Liss, Inc.
Nerve injury proximal or distal to the DRG induces similar spinal glial activation and selective cytokine expression but differential behavioral responses to pharmacologic treatment
Authors: Winkelstein Beth A. , Rutkowski Maria D. , Sweitzer Sarah M. , Pahl Janice L. , DeLeo Joyce A.
Published: October 2004

The specific mechanisms by which nervous system injury becomes a chronic pain state remain undetermined. Historically, it has been believed that injuries proximal or distal to the dorsal root ganglion (DRG) produce distinct pathologies that manifest in different severity of symptoms. This study investigated the role of injury site relative to the DRG in (1) eliciting behavioral responses, (2) inducing spinal neuroimmune activation, and (3) responding to pharmacologic interventions. Rats received either an L5 spinal nerve transection distal to the DRG or an L5 nerve root injury proximal to the DRG. Comparative studies assessed behavioral nociceptive responses, spinal cytokine mRNA and protein expression, and glial activation after injury. In separate studies, intrathecal pharmacologic interventions by using selective cytokine antagonists (interleukin‐1 [IL‐1] receptor antagonist and soluble tumor necrosis factor [TNF] receptor) and a global immunosuppressant (leflunomide) were performed to determine their relative effectiveness in these injury paradigms. Behavioral responses assessed by mechanical allodynia and thermal hyperalgesia were almost identical in the two models of persistent pain, suggesting that behavioral testing may not be a sensitive measure of injury. Spinal IL‐1β, IL‐6, IL‐10, and TNF mRNA and IL‐6 protein were significantly elevated in both injuries. The overall magnitude of expression and temporal patterns were similar in both models of injury. The degree of microglial and astrocytic activation in the L5 spinal cord was also similar for both injuries. In contrast, the pharmacologic treatments were more effective in alleviating mechanical allodynia for peripheral nerve injury than nerve root injury, suggesting that nerve root injury elicits a more robust, centrally mediated response than peripheral nerve injury. Overall, these data implicate alternate nociceptive mechanisms in these anatomically different injuries that are not distinguished by behavioral testing or the neuroimmune markers used in this study. J. Comp. Neurol. 439:127–139, 2001. © 2001 Wiley‐Liss, Inc.
Primary epithelial malignant mesothelioma of the pericardium with deciduoid features: Cytohistologic and immunohistochemical study
Authors: Reis‐Filho Jorge S. , Pope Leonora Z.B. , Milanezi Fernanda , Balderrama Cynthia M.S.R. , Serapião Maria José , Schmitt Fernando C.
Published: October 2004

Malignant mesothelioma with deciduoid features (MMWDF) is a recently characterized morphologic variant of epithelioid malignant mesothelioma, which frequently is misdiagnosed as peritoneal deciduosis or florid mesothelial hyperplasia. We report on the cytological, histological, immunohistochemical, and autopsy findings of a case of MMWDF arising in the pericardium of a 71‐yr‐old female patient. Cytology showed large, polygonal to round cells with pale to bright, eosinophilic cytoplasm, occasionally showing xantomatous pattern, containing a pleomorphic and vesicular nucleus with a single prominent nucleolus. Autopsy examination showed a neoplasm encasing the heart and great vessels. No other primary neoplasm was found. The histological analysis disclosed the typical features of MMWDF. Immunohistochemistry showed diffuse immunoreactivity for cytokeratin MNF116, HBME‐1, and calretinin in the neoplastic cells, as well as focal positivity for epithelial membrane antigen positivity in a brush border‐like pattern. All other markers were negative. We would like to stress that pathologists must be aware of the cytological and histological features of this rare variant of epithelioid malignant mesothelioma in order to avoid a misdiagnosis of a benign process or a metastatic malignancy. Diagn. Cytopathol. 2002;26:117–122; DOI 10.1002/dc.10068 © 2002 Wiley‐Liss, Inc.
Multitarget tracking using geographically separated radars
Authors: Kameda Hiroshi , Tsujimichi Shingo , Kosuge Yoshio
Published: October 2004

Joint search data technology by geographically separated radars has drawn attention. In this technique, the observation data of several radars placed in a geographically wide area are collected for tracking processing. A characteristic of this technique is the reduction of the cross range error that is a problem in single radar. Hence, improved tracking capability is expected. However, for realization it is necessary to take into account the deviations of the coordinate axes between the state variable vector of the target and the observation vector for the observation model of the tracking filter. In this paper, the difference in the coordinate axes is studied. JPDA (Joint Probabilistic Data Association), a multitarget tracking algorithm making use of the observation information of radars placed at several locations, is studied. In order to evaluate the effectiveness of the present technique, computer simulation is carried out. It is found that the tracking performance is improved over the conventional method of using only one radar. © 2002 Scripta Technica, Electron Comm Jpn Pt 1, 85(5): 34–47, 2002
Proposal and evaluation of a method of remote access to FA controllers via the internet
Authors: Kusunoki Kazuhiro , Imai Isao , Negi Tomonori , Matsuda Nori , Ushijima Kazuo
Published: October 2004

In this paper, we propose a method of implementation of a remote access system to controllers in a manufacturing line via the Internet. In order to reduce development cost, we adopt the method of not modifying user interface‐related programs in existing controller access software, but modifying communication processing programs in it. We designed three types of implementation methods according to the communication protocol translation between the controller access communication protocols and TCP/IP. From the qualitative analysis of these three methods, we determined that the TCP/IP data wrapping method is the best among the three implementations. This paper also describes our prototype implementation of a remote access system based on TCP/IP data wrapping method and evaluates the results of our proposed method. © 2002 Scripta Technica, Electron Comm Jpn Pt 1, 85(6): 23–32, 2002
Re‐ignition surge and high‐frequency arc extinction phenomena at 550‐kV shunt reactor current interruption
Authors: Okabe Shigemitsu , Koto Masanori , Koshizuka Tadashi , Shinkai Takeshi , Nishiwaki Susumu , Miyake Nobuyuki , Nakamoto Tetsuya , Saida Toshiyuki
Published: October 2004

At substations connected with transmission lines and cables, shunt reactors are sometimes installed to compensate the capacitive current of these lines and cables. It is known that re‐ignitions occur and high‐frequency currents flow during interruption of the shunt reactor currents by switches. When the high‐frequency currents are interrupted immediately after the re‐ignitions (which is called high‐frequency arc extinction), the result is often repetitive re‐ignitions or voltage escalations that produce dangerous overvoltages.

The authors investigated the occurrence of high‐frequency arc extinctions in a 550‐kV one‐break SF6 gas circuit breaker during interruption of a 550‐kV shunt reactor current. Computations for a real 550‐kV substation gave a minimum frequency of 290 kHz for the high‐frequency current. However, 550‐kV reactor current interruption tests showed that high‐frequency arc extinctions did not occur even when this frequency was lowered to 26 kHz. Since high‐frequency arc extinction is generally likely to occur at lower frequencies, it was concluded that high‐frequency arc extinction will not occur in a 550‐kV one‐break SF6 gas circuit breaker during interruption of shunt reactor current in real substations. © 2001 Scripta Technica, Electr Eng Jpn, 136(2): 18–25, 2001
Wavelet matrix transform approach for electromagnetic scattering by a dielectric cylinder
Authors: Kigoshi Katsunori , Guan Ning , Yashiro Ichiro , Ohkawa Sumio
Published: October 2004

The wavelet matrix transform approach, in combination with the conventional method of moments, is used to solve the problem of electromagnetic scattering by a dielectric cylinder. First, the problem is formulated in terms of the integral equation for the field of a harmonic source in the presence of the cylinder. Then the equation is discretized to obtain a dense system of linear equations by dividing the cylinder into square cells which are small enough so that the field intensity is nearly uniform in each cell. Finally, the wavelet matrix transform is applied to produce a sparse system of linear equations which is treated effectively by a sparse linear system solver. © 2001 Scripta Technica, Electr Eng Jpn, 137(3): 1–9, 2001
A power factor correction with two‐input current mode using voltage doubler rectifier
Authors: Yamamoto Isamu , Matsui Keiju
Published: October 2004

For rectifier circuits with a small capacity, such as those for consumer electronics and appliances, capacitor input‐type rectifier circuits are generally used. Consequently, various harmonics generated within the power system become a serious problem. Various studies of this effect have been reported. However, most of these employ switching devices, such as FETs and the like. The absence of switching devices makes systems more tolerant to overload, and brings low radio noise benefits. We propose a power factor correction scheme using a voltage doubler rectifier without switching devices. In this method, the input current is divided into two periods, where one period charges the small input capacitor and the other charges the large output capacitor. By dividing the input current into two different modes, the current conduction period can be widened and harmonics can largely be canceled between the two modes. Hence, the harmonic characteristics can be significantly improved, whereby the lower‐order harmonics, such as the fifth and seventh orders, are much reduced. The results are confirmed by theoretical and experimental implementations. © 2001 Scripta Technica, Electr Eng Jpn, 137(3): 52–58, 2001
Cover Picture: Complex Formation of ICL670 and Related Ligands with FeIII and FeII (Eur. J. Inorg. Chem. 20/2004)
Authors: Steinhauser Stefan , Heinz Uwe , Bartholomä Mark , Weyhermüller Thomas , Nick Hanspeter , Hegetschweiler Kaspar
Published: October 2004

The cover picture shows the structure of the FeIII‐selective chelating agent ICL670 (R = COOH). ICL670 has a high potential for the oral treatment of iron overload, a condition that originates from regular blood transfusions, as are necessary in the treatment of β‐Thalassaemia. However, a possible problem arising from this treatment is the production of OH· radicals, which can be catalysed by redox‐cycling of labile FeII/FeIII species. For a conclusive consideration of potential oxidative stress, a careful elucidation of the stability and redox properties of the various FeII/FeIII species, which are present at physiological conditions, has been performed. Details are discussed in the article by K. Hegetschweiler et al. on p. 4177 ff.
Functional expression of V‐ATPases in the plasma membrane of glial cells
Authors: Philippe Jean‐Marc , Dubois Jean‐Marc , Rouzaire‐Dubois Beatrice , Cartron Pierre‐François , Vallette François , Morel Nicolas
Published: October 2004

Vacuolar H+ ATPase (V‐ATPase) activity is essential for many cellular processes, including intracellular membrane traffic, protein processing and degradation, and receptor‐mediated endocytosis. Proton transport by V‐ATPases could also play a role during cell transformation, tumorigenesis, and cell metastasis, and V‐ATPase c‐subunit overexpression was reported to be correlated with invasiveness of pancreatic tumors (Ohta et al., 1996). In the present work, we found that mRNAs encoding V‐ATPase subunits are not overexpressed in C6 tumoral glioma cells when compared with immortalized astrocytes DI TNC1 and astrocytes in primary cultures. Accordingly, V‐ATPase subunit mRNA levels are similar in human gliomas (grade II or IV) and in peritumoral tissues. A significant proportion (25%) of V‐ATPase is present in the plasma membrane of both the C6 and the DI TNC1 astrocytic cells in culture. A bafilomycin‐sensitive hyperpolarizing pump current through the plasma membrane was detected and measured after ionic channel inhibition, which corresponds most probably to an electrogenic transport of protons. This suggests that the plasma membrane V‐ATPase is active. It could contribute to cytoplasmic pH regulation in astrocytic cells. GLIA 37:365–373, 2002. © 2002 Wiley‐Liss, Inc.
Identification of growth factors that promote long‐term proliferation of olfactory ensheathing cells and modulate their antigenic phenotype
Authors: Alexander Claire L. , Fitzgerald Una F. , Barnett Susan C.
Published: October 2004

Olfactory ensheathing cells can develop into distinct subtypes in culture after incubation in serum‐free medium conditioned by astrocytes, which have Schwann cell–like and astrocyte‐like properties. It has not been possible so far to modulate and grow large numbers of these olfactory ensheathing cell subtypes. In this study, we have shown that astrocyte‐conditioned medium, although promoting differentiation of the two olfactory ensheathing cell types, is growth‐restrictive after 14 days, probably due to the upregulation of p16 and p27. Growth arrest can be overridden and cells maintained for a further 11 weeks, by a mitogen mix of fibroblast growth factor 2, forskolin, and heregulin (olfactory mitogen medium) combined with astrocyte‐conditioned medium. In the absence of astrocyte‐conditioned medium, combinations of the same factors can also override growth arrest but to a lesser extent. Olfactory mitogen medium combined with astrocyte‐conditioned medium upregulates O4 and low‐affinity nerve growth factor receptor expression on olfactory ensheathing cells, leading to a 100% Schwann cell–like phenotype. If cells are maintained in olfactory mitogen medium alone, or if they are treated with forskolin or fibroblast growth factor 2 diluted in serum‐free medium, O4 and low‐affinity nerve growth factor receptor expression remains at 100%, but there is also an increase in expression of E‐NCAM, the astrocyte‐like marker. Medium containing serum also overrides growth arrest, but for only 4 weeks, during which time most differentiation‐specific markers disappear. These studies have allowed us to define conditions to modulate the olfactory ensheathing cell phenotype. GLIA 37:349–364, 2002. © 2002 Wiley‐Liss, Inc.
Mts1 protein expression in the central nervous system after injury
Authors: Kozlova Elena N. , Lukanidin Eugene
Published: October 2004

We recently showed that Mts1 is expressed in white matter astrocytes in the rat brain and spinal cord from the first postnatal day. Its expression level declined in the adult CNS, but its topographical localization was maintained. Only white matter astrocytes in the cerebellum did not express Mts1. After dorsal root or sciatic nerve injury, we observed a marked upregulation of Mts1 in the area of the dorsal funiculus undergoing Wallerian degeneration. Here we show that upregulation of Mts1 is a consistent feature of astrocytes in white matter undergoing Wallerian degeneration. In addition, Mts1 is upregulated in astrocytes outlining the lesion site of a penetrating injury to the forebrain, or cerebellum. Gray matter astrocytes did not express Mts1, even after direct injury. In injured brain, we consistently noted a close relationship between Mts1‐expressing astrocytes and ED1‐positive microglia/macrophages, which are known to be highly motile cells. Mts1 was expressed in the periventricular area and the rostral migratory stream, i.e., sites of ongoing neuroplasticity in adulthood, and was upregulated in these areas after injury. These data suggest that Mts1‐expressing astrocytes play a significant role in degenerative events in the mature white matter, interact with phagocytic microglia/macrophages and regulate cell migration and differentiation in areas of the adult brain with a high degree of plasticity. GLIA 37:337–348, 2002. © 2002 Wiley‐Liss, Inc.
CNTF and CNTF receptor alpha are constitutively expressed by astrocytes in the mouse brain
Authors: Dallner Christine , Woods Alisa G. , Deller Thomas , Kirsch Matthias , Hofmann Hans‐Dieter
Published: October 2004

Ciliary neurotrophic factor (CNTF) is regarded as one of the signals that lead to astrocyte activation following central nervous system lesion. However, it is not clear if CNTF can directly initiate astrocytic responses to injury because CNTF levels are very low in most areas of the unlesioned brain and CNTF receptor (CNTFRα) expression by astrocytes has not yet been demonstrated in the intact brain. In the present study, the expression patterns of CNTF protein and CNTFRα mRNA were studied in the intact mouse brain using immunocytochemistry and in situ hybridization, respectively. These procedures were combined with immunocytochemistry for glial fibrillary acidic protein in order to identify CNTF‐ and CNTFRα‐expressing astrocytes. CNTF‐immunoreactive astrocytes were exclusively found in white matter structures such as the optical tract, the corticospinal tract, and the fimbria‐fornix. Gray matter astrocytes did not exhibit CNTF immunoreactivity. In contrast, CNTFRα mRNA‐expressing astrocytes were found in gray matter areas, preferentially in the molecular layers of the cortex and hippocampus. White matter astrocytes did not show a detectable CNTFRα mRNA signal. These data demonstrate that both CNTF and its receptor are constitutively expressed by astrocytes in mouse brain. The nonoverlapping locations of astrocytes expressing detectable levels of CNTF and CNTFRα, respectively, may be related to distinct postlesional functions of these two glial cell populations. GLIA 37:374–378, 2002. © 2002 Wiley‐Liss, Inc.
Astrocyte‐derived factors modulate the inhibitory effect of ethanol on dendritic development
Authors: Yanni Penelope A. , Rising Lisa J. , Ingraham Christine A. , Lindsley Tara A.
Published: October 2004

Numerous studies in vivo and in vitro have demonstrated that ethanol disrupts neuromorphogenesis. However, it has not been determined what role, if any, is played by non‐neuronal cells in mediating this effect. We recently reported that ethanol inhibits dendritic development in low‐density cultures of fetal rat hippocampal pyramidal neurons (Yanni and Lindsley, 2000: Dev Brain Res 120:233–243). In this culture system, cortical astrocytes precondition neuronal culture media for 2 days before the addition of neurons, which then develop on a separate substrate in coculture with the astrocytes. To determine whether astrocyte response to ethanol mediates the effects of ethanol on neurons, the present study compared dendritic development of neurons after 6 days in medium containing 400 mg/dl ethanol in coculture with live astrocytes and in conditioned medium from astrocytes that were never exposed to ethanol. The same experiment was also performed with and without ethanol present during astrocyte preconditioning of the medium. The effects of ethanol differed depending on when it was added to the cultures relative to addition of newly dissociated neurons. However, the effects of ethanol were not related to whether neurons were cocultured with live astrocytes. When astrocytes preconditioned the medium normally, ethanol added at plating inhibited dendritic development of neurons regardless of whether they were maintained in coculture with live astrocytes or in conditioned medium. In surprising contrast, the presence of ethanol during astrocyte preconditioning of the media had a growth promoting effect on subsequent dendrite development despite the continued presence of ethanol in the medium. Thus, astrocytes release soluble factors in response to ethanol that can protect neurons from the inhibitory effects of ethanol on dendritic growth, but the timing of neuronal exposure to these factors, or their concentration, may influence their activity. GLIA 38:292–302, 2002. © 2002 Wiley‐Liss, Inc.
Areas of brain activation in males and females during viewing of erotic film excerpts
Authors: Karama Sherif , Lecours André Roch , Leroux Jean‐Maxime , Bourgouin Pierre , Beaudoin Gilles , Joubert Sven , Beauregard Mario
Published: October 2004

Various lines of evidence indicate that men generally experience greater sexual arousal (SA) to erotic stimuli than women. Yet, little is known regarding the neurobiological processes underlying such a gender difference. To investigate this issue, functional magnetic resonance imaging was used to compare the neural correlates of SA in 20 male and 20 female subjects. Brain activity was measured while male and female subjects were viewing erotic film excerpts. Results showed that the level of perceived SA was significantly higher in male than in female subjects. When compared to viewing emotionally neutral film excerpts, viewing erotic film excerpts was associated, for both genders, with bilateral blood oxygen level dependant (BOLD) signal increases in the anterior cingulate, medial prefrontal, orbitofrontal, insular, and occipitotemporal cortices, as well as in the amygdala and the ventral striatum. Only for the group of male subjects was there evidence of a significant activation of the thalamus and hypothalamus, a sexually dimorphic area of the brain known to play a pivotal role in physiological arousal and sexual behavior. When directly compared between genders, hypothalamic activation was found to be significantly greater in male subjects. Furthermore, for male subjects only, the magnitude of hypothalamic activation was positively correlated with reported levels of SA. These findings reveal the existence of similarities and dissimilarities in the way the brain of both genders responds to erotic stimuli. They further suggest that the greater SA generally experienced by men, when viewing erotica, may be related to the functional gender difference found here with respect to the hypothalamus. Hum. Brain Mapping 16:1–13, 2002. © 2002 Wiley‐Liss, Inc.
Monte Carlo simulation studies of EEG and MEG localization accuracy
Authors: Liu Arthur K. , Dale Anders M. , Belliveau John W.
Published: October 2004

Both electroencephalography (EEG) and magnetoencephalography (MEG) are currently used to localize brain activity. The accuracy of source localization depends on numerous factors, including the specific inverse approach and source model, fundamental differences in EEG and MEG data, and the accuracy of the volume conductor model of the head (i.e., the forward model). Using Monte Carlo simulations, this study removes the effect of forward model errors and theoretically compares the use of EEG alone, MEG alone, and combined EEG/MEG data sets for source localization. Here, we use a linear estimation inverse approach with a distributed source model and a realistic forward head model. We evaluated its accuracy using the crosstalk and point spread metrics. The crosstalk metric for a specified location on the cortex describes the amount of activity incorrectly localized onto that location from other locations. The point spread metric provides the complementary measure: for that same location, the point spread describes the mis‐localization of activity from that specified location to other locations in the brain. We also propose and examine the utility of a “noise sensitivity normalized” inverse operator. Given our particular forward and inverse models, our results show that 1) surprisingly, EEG localization is more accurate than MEG localization for the same number of sensors averaged over many source locations and orientations; 2) as expected, combining EEG with MEG produces the best accuracy for the same total number of sensors; 3) the noise sensitivity normalized inverse operator improves the spatial resolution relative to the standard linear estimation operator; and 4) use of an a priori fMRI constraint universally reduces both crosstalk and point spread. Hum. Brain Mapping 16:47–62, 2002. © 2002 Wiley‐Liss, Inc.
Necrotizing fasciitis of the head and neck: A report of two patients and review
Authors: Chattar‐Cora Deowall , Tulsyan Nirman , Cudjoe Ernest A. , Onime Godfrey D. , Pyo Daniel J. , Weinstein Larry
Published: October 2004

Background

Necrotizing fasciitis is a disfiguring condition that can be fatal. The head and neck region is rarely affected. However, when involved, the functional and cosmetic sequelae can be considerable.

Materials and Methods

We present two case histories, discuss salient diagnostic points, treatment, and review published data on this topic.

Results

With a timely diagnosis we were able to diagnose and appropriately treat these patients.

Conclusions

Necrotizing fasciitis is a disfiguring condition that can be fatal if not diagnosed in a timely fashion. Diagnosis and treatment require a high index of suspicion, immediate operative intervention, broad‐spectrum antibiotics, and appropriate supportive care. © 2002 Wiley Periodicals, Inc.
Role of Epstein‐Barr virus and cytomegalovirus in the etiology of benign parotid tumors
Authors: Laane Christina J. , Murr Andrew H. , Mhatre Anand N. , Jones Kirk D. , Lalwani Anil K.
Published: October 2004

Background

Pleomorphic adenomas and Warthin's tumors are the two most common benign parotid tumors. Previous studies investigating the role of viruses in tumorigenesis of these neoplasms have been conflicting. The aim of this study was to determine whether Epstein‐Barr virus (EBV) or cytomegalovirus (CMV) might play a role in the pathogenesis of pleomorphic adenomas and Warthin's tumors.

Methods

Paraffin‐embedded surgical specimens of 24 pleomorphic adenomas, 10 Warthin's tumors, and 13 normal parotid tissues were obtained from the University of California–San Francisco Pathology Department. Genomic DNA was extracted from the specimens, and primers for connexin 26, a gap junction protein, were used to confirm the integrity of this DNA. The presence or absence of EBV and CMV DNA within the samples was determined with PCR‐based assays, in which radiolabeled primers were used for maximal sensitivity of detection.

Results

PCR analysis of serially diluted control DNA revealed that using radiolabeled primers, five copies of viral DNA could be detected. By use of this method, we showed that none of the 24 pleomorphic adenomas, 10 Warthin's tumors, or 13 normal parotid samples contained EBV DNA or CMV DNA.Conclusions. These results do not support CMV or EBV as etiologic factors in pleomorphic adenomas or Warthin's tumors. In addition, normal parotid seems not to harbor either of these viruses. Future studies with larger numbers of specimens are needed to confirm these findings. © 2002 Wiley Periodicals, Inc.
Functional assessment using Constant's Shoulder Scale after modified radical and selective neck dissection
Authors: Chepeha Douglas B. , Taylor Rodney J. , Chepeha Judith C. , Teknos Theodoros N. , Bradford Carol R. , Sharma Pramod K. , Terrell Jeffrey E. , Wolf Gregory T.
Published: October 2004

Background

Constant's Shoulder Scale is a validated and widely applied instrument for assessment of shoulder function. We used this instrument to assess which treatment and demographic variables contribute to shoulder dysfunction after neck dissection in head and neck cancer patients.

Methods

A convenience sample of 54 patients with 64 neck dissections and minimum follow‐up of 11 months were evaluated. Thirty‐two accessory nerve–sparing modified radical (MRND) and 32 selective neck (SND) dissections were performed. Multivariable regression analysis was used to determine the variables that were predictive for shoulder dysfunction. Clinical variables included age, time from surgery, handedness, weight, radiation therapy, neck dissection type, tumor stage, and site.

Results

Patients receiving MRND had significantly worse shoulder function than patients with SND (p = .0007). Radiation therapy contributed negatively, whereas weight contributed positively (p = .0001).

Conclusions

The critical factors contributing to shoulder dysfunction after neck dissection were weight, radiation therapy, and neck dissection type. © 2002 Wiley Periodicals, Inc.
Prognostic factors in head and neck rhabdomyosarcoma
Authors: Simon James H. , Paulino Arnold C. , Smith Russell B. , Buatti John M
Published: October 2004

Background

Rhabdomyosarcoma comprises less than 1% of all head and neck cancer. The purpose of our study is to review our institutional experience in this disease and to identify possible prognostic factors for patients with head and neck rhabdomyosarcoma.

Methods

One hundred forty patients with rhabdomyosarcoma were identified from 1955–1999 within the tumor registry. Of these cases, 49 (35%) were noted to be primary head and neck rhabdomyosarcomas. Retrospective chart reviews were completed to obtain the following data: age, gender, site, tumor size, histologic findings, Intergroup Rhabdomyosarcoma Study Group, treatment, local control, and survival.

Results

The 5‐year overall survival and local control rates were 60% ± 14% and 70% ± 14%, respectively. Tumor size ≤5 cm (p = .014) and age ≤11 years (p = .036) were predictive of improved survival, whereas age ≤11 years was predictive of improved local control (p = .006). Children ≤11 years with a≤5‐cm tumor have the best overall survival, whereas patients >11 years with a tumor >5 cm have the worst survival. The 5‐year survival was intermediate for children ≤11 years with a >5‐cm tumor and patients >11 years with a ≤5‐cm tumor. Radiotherapy treatment duration ≤45 days in group III disease was associated with improved overall survival but not local control. For the six patients with group I or II disease, who did not receive initial chemotherapy, five had relapses at the primary and/or distant sites.

Conclusions

Improvement in outcome was obtained with multimodality treatment regimens for head and neck rhabdomyosarcoma. Both tumor size and age of patient were found to influence survival. © 2002 Wiley Periodicals, Inc.
Fetal operations in the head and neck area: current state
Authors: Wagner Wolfgang , Harrison Michael R.
Published: October 2004

Background

Fetal surgery is defined as prenatal surgical intervention. Such intervention is currently considered in selected cases of fetal malformations that endanger the child’s life prenatally or postnatally, such as death or severe impairment.

Methods

Current indications are reviewed, with special emphasis on success rates and complications, including concomitant ethical problems. Data sources are based on personal experience and medical information systems (especially MEDLINE).

Results and Conclusions

In the head and neck areas, especially the upper respiratory tract, such procedures can be indicated in selected cases. They include exposure and temporary obstruction of the fetal trachea to reduce the viscera and to prevent pulmonary hypoplasia in congenital diaphragmatic hernia, prenatal tracheotomy in laryngeal atresia, and intranatal establishment of an airway in airway‐obstructing embryonic tumors. The latter surgery can be performed after delivery of the fetal head and neck and before umbilical cord severance. This method ensures oxygenation of the fetus by the maternofetal circulation until completion of the surgical intervention (so called EXIT procedure = Ex‐Utero Intrapartum Treatment). The relatively high surgical risk of fetal surgery, in particular postoperative preterm labor, may be reduced by the use of minimally invasive endoscopic techniques. By reducing operative risks even further, prenatal surgical interventions may even be used in nonlethal conditions. Consequently, more diseases of the head and neck area could thus be included in the spectrum of indications, such as prenatal correction of the cleft lip palate. Because fetal wound healing incurs no scarring up to a certain stage in pregnancy, such fetal surgical correction could be a perspective. © 2002 Wiley Periodicals, Inc. Head Neck 24: 482–490, 2002
Performance obstacles in cellular manufacturing implementation— empirical investigation
Authors: Park K. S. , Han S. W.
Published: October 2004

Performance obstacles are factors in the work environment that restrict productivity by inhibiting workers in the execution of task responsibilities. It is thus crucial to identify and reduce those obstacles for more effective cellular manufacturing implementation. This article describes research carried out in 4 Korean manufacturing plants to investigate performance obstacles in cellular manufacturing implementation. The results of the research reveal several important factors in cellular manufacturing implementation: training and education, information, teamwork skill, supervision, and scheduling. This research discusses human and organizational factors in new manufacturing system implementation and reveals that those factors play a central role in the implementation. © 2002 John Wiley & Sons, Inc.
Dentin proteoglycans: An immunocytochemical FEISEM study
Authors: Breschi L. , Lopes M. , Gobbi P. , Mazzotti G. , Falconi M. , Perdigão J.
Published: October 2004

Dentin proteoglycans are fundamental constituents of the dentin matrix and are distributed ubiquitously both in dentin and cement. They have several important functional properties; in particular, they have a fundamental role in the maintenance and the correct stabilization of collagen fibers. The use of phosphoric acid on dentin, as proposed in most common dental adhesive systems to establish a reliable bond, may affect the molecular structure of proteoglycans. The aim of this study was to evaluate, after the application of EDTA or phosphoric acid on dentin, the dentin proteoglycans with an immunocytochemical approach with high resolution SEM. For this purpose, dentin disks obtained from recently extracted human molars were etched with a 35% water solution of phosphoric acid for 15 s, 30 s, and 60 s. Control specimens were conditioned with EDTA. Specimens were immunolabeled with a monoclonal antibody antichondroitin sulfate and visualized with a gold‐conjugated secondary antibody. Conditioning dentin with EDTA resulted in a distinct labeling of the proteoglycans, as visualized on branching fibrillar structures in the order of 10–20 nm. The use of 35% phosphoric acid on dentin revealed a coagulation of proteoglycans after etching for 15 s while a very low labeling signal was detectable after 30 s. No labeling was obtained after etching dentin with phosphoric acid for 60 s. These results suggest that the use of 35% phosphoric acid on dentin is able to produce significant structural modifications of the dentin proteoglycans even after short application times. Additionally, when applied on the dentin surface for more than 30 s, phosphoric acid produces a dramatic decrease in proteoglycans’ antigenicity, probably due to structural modifications of the three‐dimensional conformation of these molecules. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 40–46, 2002.
Self‐curing acrylic formulations containing PMMA/PCL composites: Properties and antibiotic release behavior
Authors: Méndez José A. , Abraham Gustavo A. , Fernández María del Mar , Vázquez Blanca , Román Julio San
Published: October 2004

Partially biodegradable acrylic composites containing poly(methyl methacrylate)–poly(ϵ‐caprolactone) (PMMA/PCL) systems were prepared by mixing the corresponding PMMA/PCL beads (89:11, 86:14, 83:17, and 77:23 weight ratio) used as solid phase with methyl methacrylate (MMA) (liquid phase) in a solid/liquid ratio of 1.5:1. The physical and chemical microheterogeneity of these beads influenced significantly the curing parameters, because several aspects involved in the polymerization reaction are closely related to both morphology and size distribution of the particles. In vitro behavior was studied by immersion in simulated body fluid at pH = 7.4 and 37°C for more than 8 weeks and the composition was followed by 1H‐nuclear magnetic resonance spectroscopy. Approximately 2% wt/wt weight loss was observed after a period of 8 weeks for the composites richest in PCL. Mechanical properties of the dry and wet specimens were evaluated by compressive and tensile tests. In all cases, the presence of PCL in the composites provided a significant decrease in both compressive strength and elastic modulus compared with plain PMMA. Tensile and compressive strength also decreased significantly after 2 weeks of immersion in simulated body fluid compared with dry specimens. The self‐curing composites based on PMMA/PCL beads and loaded with 3% wt/wt vancomycin were evaluated as carriers for local release of antibiotics. The composite prepared with beads of PMMA/PCL ratio 86:14 was the most effective. It eluted 64% of the initial drug within the first 5 h, allowing progressive release of nearly the total amount of the initial drug (90%) in approximately 2 months. The results obtained suggest that the described composites can be suitable for antibiotic release in non‐load bearing graft applications. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 66–74, 2002
Chondroinduction of mouse mesenchymal stem cells in three‐dimensional highly porous matrix scaffolds
Authors: Aung Tun , Miyoshi Hirotoshi , Tun Thein , Ohshima Norio
Published: October 2004

Porous polyvinyl formal (PVF) resin and poly(lactide‐caprolactone) [P(LA/CL)] sponges were examined as three‐dimensional matrices for chondroinduction of cultured bone marrow mesenchymal stem cells (MSCs). Approximately 5 × 105 mouse MSCs were seeded in porous PVF resin or P(LA/CL) sponges and were cultured for up to 1 month in serum‐free high‐glucose Dulbecco's modified Eagle's medium containing 10 ng/mL transforming growth factor‐β3 and 100 nM dexamethasone for chondroinduction. After the 1‐month culture period, the PVF resin and P(LA/CL) sponges contained approximately twice the amount of glycosaminoglycans compared with the control pellet. Safranin‐O staining of PVF and P(LA/CL) after 1 month of culture revealed a cartilage‐like extracellular matrix containing glycosaminoglycans and collagen. When implanted into nude mice, PVF and P(LA/CL) seeded with MSCs were found to be both biocompatible and chondroinductive. These highly porous scaffolds can maintain a large number of cells in a three‐dimensional structure. Both are potentially promising for the chondroinduction of bone marrow MSCs for research and clinical applications. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 75–82, 2002
Cytotoxicity of glutaraldehyde crosslinked collagen/poly(vinyl alcohol) films is by the mechanism of apoptosis
Authors: Gough Julie E. , Scotchford Colin A. , Downes Sandra
Published: October 2004

Collagen has been investigated as a potential natural biomaterial, because of its occurrence in the extracellular matrix. Collagen requires crosslinking in this context, by reagents that are often cytotoxic. Glutaraldehyde is one such agent that is potentially cytotoxic. The aim of this study was to determine the cause of poor cell attachment and growth on collagen/poly(vinyl alcohol) bioartificial composite films, when crosslinked with glutaraldehyde. Dehydrothermal crosslinking was used as a comparison. Human osteoblasts were observed to undergo apoptosis on glutaraldehyde crosslinked films dependent on concentration of collagen present. Higher collagen content resulted in higher levels of apoptosis with poor cell attachment and spreading of remaining cells. Post‐treatment of films with 8% L‐glutamic acid prevented the apoptotic response of osteoblasts and allowed attachment and spreading. The addition of 100 nM insulin‐like growth factor‐1 to the culture medium also prevented apoptosis. Glutaraldehyde toxicity of crosslinked collagen has been demonstrated in this study, the mechanism of which is apoptosis. This study indicates that poor biocompatibility and induction of apoptosis on collagen/poly(vinyl alcohol) films crosslinked by glutaraldehyde are attributed to glutaraldehyde components on the surface of the films (not residual glutaraldehyde), whose effects can be quenched by glutamic acid, and prevented by insulin‐like growth factor‐1. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 121–130, 2002
Synthesis of pH‐sensitive inulin hydrogels and characterization of their swelling properties
Authors: Chiu Hsin‐Cheng , Hsu Yuan‐Hung , Lin Pei‐Jung
Published: October 2004

In this study, pH‐responsive inulin hydrogels were prepared by radical copolymerization of methacrylated inulin (MA‐inulin) with acrylic acid (AAc) in aqueous solution using ammonium peroxydisulfate (APS) and N,N,N′,N′‐tetramethylethylenediamine (TMEDA) as an initiation system. The AAc content in hydrogels was evaluated by FTIR spectroscopy. The covalent bridging of AAc among MA moieties of MA‐inulins was observed by a significant increase in the effective network density of hydrogels and further confirmed by TGA studies. While, at a low content of AAc, the hydration of hydrogels at pH 7.4 decreased owing to the increased crosslinking density, the swelling subsequently increased with further increasing AAc as a consequence of the increased ionic osmotic pressure within hydrogels. The change in swelling of hydrogels in response to pH change between 7.4 and 2.2 was therefore enlarged when the AAc content increased. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61:146–152, 2002
In vitro mineralization of a glass‐ceramic of the MgO‐3CaO · P2O5‐SiO2 system: Wettability studies
Authors: Serro A. P. , Fernandes A. C. , Saramago B. , Fernandes M. H. V.
Published: October 2004

The calcium phosphate deposition on the surface of a bioactive glass‐ceramic of the MgO‐3CaO · P2O5‐SiO2 system during a 1‐week immersion in biological model fluids, was investigated through wettability studies. Two model fluids with chemical composition similar to the human blood plasma were tested: Hanks’ balanced salt solution (HBSS) and a simulated body fluid (SBF) with a higher calcium content. The effect of the presence of albumin, both in solution or previously adsorbed to the surface, was assessed. The behavior observed using two SBF solutions prepared with and without TRIS buffer was compared. The surface free energy of the glass‐ceramic samples was determined, before and after immersion, and dynamic contact angle analysis was performed using the biological model fluids as scanning liquids. Scanning electron microscope observations and x‐ray photoelectron spectroscopy (XPS) analysis were performed to complement the wettability studies. The experimental results led to the conclusion that the precipitation of a calcium phosphate film in HBSS occurred mainly when the immersion solution was renewed daily or in the presence of adsorbed albumin. In SBF, the addition of TRIS buffer seemed to inhibit the formation of the calcium phosphate film. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 99–108, 2002
Selective induction of mitogen‐activated protein kinases in human lens epithelial cells by ultraviolet radiation
Authors: Bomser Joshua A.
Published: October 2004

The present study investigates the effects of ultraviolet radiation (UVR) on mitogen‐activated protein kinase (MAPK) activity in human lens epithelial (HLE) cells. Irradiation of HLE cells with ultraviolet B and ultraviolet C radiation activates the stress‐response MAPK proteins, p38 and c‐Jun NH2‐terminal kinase (JNK), in a dose‐ and time‐dependent manner, while the extracellular‐regulated signal kinase (ERK 44/42) cascade was not altered by UVR exposure. Ultraviolet A radiation failed to elicit a MAPK response. UVR‐induced MAPK activation does not require protein kinase C or phosphatidylinositol 3‐kinase activity, suggesting that this is not a receptor‐mediated event. Inhibition of ribosomal translation completely abolished UVR‐induced MAPK activation, while treatment with the antioxidant, N‐acetyl cysteine, and mild heat shock had no effect on this activation. These data demonstrate for the first time the selective activation of MAPK cascades in a lens epithelial cell line. © 2002 Wiley Periodicals, Inc. J Biochem Mol Toxicol 16:33–40, 2002; DOI 10.1002/jbt.10016