bluuebunny/crossref_metadata_2025 huggingface dataset:
Cellular non‐linear networks for minimization of functionals. Part 1: Theoretical aspects
Authors: Storace Marco , Bizzarri Federico , Parodi Mauro
Published: August 2002

A method for the definition of cellular non‐linear networks able to find approximate minima of rather a large class of continuous functionals is proposed and discussed from a theoretical point of view. The method is based on the spatial discretization of continuous functionals and on the theory of potential functions for resistive circuits. The discretization of the continuous functionals is obtained by resorting to the finite difference method or to the finite element method. The spatial discretization converts a functional into a function of a finite set of variables. By exploiting the theory of potential functions for resistive circuits, from such a function one can derive a lumped circuit that makes it possible to find an approximate minimum of the given functional. Copyright © 2001 John Wiley & Sons, Ltd.
Probabilistic design of systems with general distributions of parameters
Authors: Ponnambalam K. , Seifi Abbas , Vlach Jiri
Published: August 2002

This paper presents a new method for finding optimal solutions of systems with design parameters which are random variables distributed with various general and possibly non‐symmetrical distributions. A double‐bounded density function is used to approximate the distributions. Specifications may require tracking constraints in time domain and stability conditions in frequency domain. Using sensitivity information, the proposed method first finds a linearized feasible region. Afterwards it attempts to place a tolerance box of the design parameters such that the region with higher yield lies in the feasible region. The yield is estimated by the joint cumulative density function over a portion of the tolerance box contained in the feasible region. Optimal designs are found for a fourth‐order servomechanism and actual yields are evaluated by Monte‐Carlo simulation. Copyright © 2001 John Wiley & Sons, Ltd.
Existence and uniqueness of solutions for DC networks containing non‐linear ideal op amps
Authors: Ciampa Maurizio
Published: August 2002

In this paper we are concerned with networks obtained by connecting independent sources, linear resistors and non‐linear ideal op amps. A necessary and sufficient condition for the existence and uniqueness of solutions for every positive output saturation voltage of the op amps and every value of the independent sources is found. Copyright © 2001 John Wiley & Sons, Ltd.
Transcriptional profiling develops molecular signatures for ovarian tumors
Authors: Smith David I.
Published: August 2002

Of the cancers unique to women, ovarian cancer has the highest mortality rate. Over 26,000 women are diagnosed with this disease in the U.S. annually, and 60% of those diagnosed will die of the disease. One of the greatest problems with this disease is the lack of strong early warning signs or symptoms resulting in advanced stage at presentation in most women, followed by the outgrowth of chemotherapy‐resistant disease in the majority of patients. The 5‐year survival for patients with early stage disease ranges from 50‐90%, but it is less than 25% for advanced‐stage disease. In collaboration with researchers at Millennium Predictive Medicine (Cambridge, MA), the Ovarian Cancer Program of the Mayo Clinic Cancer Center analyzed gene expression in over 50 primary ovarian tumors, as compared with normal ovarian epithelial cells. The technologies utilized included microarray analysis with nitrocellulose filters containing 25,000 arrayed human cDNAs, as well as the construction of subtraction suppression hybridization cDNA libraries and their subsequent sequencing. Our specific focus has been on genes that are underexpressed during the development of ovarian cancer, although this analysis has revealed a large number of consistently up‐ and down‐regulated genes. There were more down‐regulated genes in ovarian tumors than up‐regulated genes. In addition, the number of genes that had altered expression levels was quite large. For example, we found 409 genes down‐regulated at least 5‐fold, and 72 genes up‐regulated at least 5‐fold in 33% of the tumors analyzed. We also observed that most of the expression alterations observed in later stage (Stages III/IV) tumors were also observed in early‐stage tumors (Stages I/II). This was corroborated using comparative genomic hybridization analysis on the same tumors that were expression profiled. This analysis revealed that the late‐stage tumors had more gene amplification than early‐stage tumors, but most regions of change (either increases or decreases) were in common between different stage tumors. We also have verified the altered expression levels of several of these genes using several complementary strategies. Finally, we are taking top candidate genes that are consistently under‐expressed in ovarian tumors and attempting to determine their functional role in the development of ovarian cancer. Cytometry 47:60–62, 2002. © 2001 Wiley‐Liss, Inc.
Magnetic field design for selecting and aligning immunomagnetic labeled cells
Authors: Tibbe Arjan G.J. , de Grooth Bart G. , Greve Jan , Dolan Gerald J. , Rao Chandra , Terstappen Leon W.M.M.
Published: August 2002

Background

Recently we introduced the CellTracks cell analysis system, in which samples are prepared based on a combination of immunomagnetic selection, separation, and alignment of cells along ferromagnetic lines. Here we describe the underlying magnetic principles and considerations made in the magnetic field design to achieve the best possible cell selection and alignment of magnetically labeled cells.

Materials and Methods

Computer simulations, in combination with experimental data, were used to optimize the design of the magnets and Ni lines to obtain the optimal magnetic configuration.

Results

A homogeneous cell distribution on the upper surface of the sample chamber was obtained with a magnet where the pole faces were tilted towards each other. The spatial distribution of magnetically aligned objects in between the Ni lines was dependent on the ratio of the diameter of the aligned object and the line spacing, which was tested with magnetically and fluorescently labeled 6 μm polystyrene beads. The best result was obtained when the line spacing was equal to or smaller than the diameter of the aligned object.

Conclusions

The magnetic gradient of the designed permanent magnet extracts magnetically labeled cells from any cell suspension to a desired plane, providing a homogeneous cell distribution. In addition, it magnetizes ferro‐magnetic Ni lines in this plane whose additional local gradient adds to the gradient of the permanent magnet. The resultant gradient aligns the magnetically labeled cells first brought to this plane. This combination makes it possible, in a single step, to extract and align cells on a surface from any cell suspension. Cytometry 47:163–172, 2002. © 2002 Wiley‐Liss, Inc.
Capacity analysis for underlaying CDMA microcell/macrocell systems
Authors: Chung Jen‐Kung , Wu Jung‐Shyr
Published: August 2002

The CDMA system can provide more capacity than the conventional AMPS system and the hierarchical layer of cells is required for system design in the future. However, the problem is whether the same RF channels used in a CDMA underlaying macrocell/microcell structure also obtain high capacity as in the homogeneous structure. This paper investigates the interference of uplink and downlink from both the microcell and macrocell in a hierarchical structure. Downlink power control is also considered. The results show that the capacity of microcell in a hierarchical structure is 23 per cent less than in homogeneous cells. The capacity of macrocell in a hierarchical structure decreases dramatically in proportion to the number of microcells. The capacities of the microcell and macrocell are limited in downlink, and uplink, respectively. In addition, more efforts for microcell should be made, such as more power is transmitted by microcell basestation if the same RF channel is used in a hierarchical structure. The results suggest that different RF channels are used in a two‐tier cellular environment. Copyright © 2001 John Wiley & Sons, Ltd.
Fast ping‐pong arbitration for input–output queued packet switches
Authors: Chao H. Jonathan , Lam Cheuk H. , Guo Xiaolei
Published: August 2002

Input–output queued switches have been widely considered as the most feasible solution for large capacity packet switches and IP routers. In this paper, we propose a ping‐pong arbitration scheme (PPA) for output contention resolution in input–output queued switches. The challenge is to develop a high speed and cost‐effective arbitration scheme in order to maximize the switch throughput and delay performance for supporting multimedia services with various quality‐of‐service (QoS) requirements. The basic idea is to divide the inputs into groups and apply arbitration recursively. Our recursive arbiter is hierarchically structured, consisting of multiple small‐size arbiters at each layer. The arbitration time of an n‐input switch is proportional to log4⌈n/2⌉ when we group every two inputs or every two input groups at each layer. We present a 256×256 terabit crossbar multicast packet switch using the PPA. The design shows that our scheme can reduce the arbitration time of the 256×256 switch to 11 gates delay, demonstrating the arbitration is no longer the bottleneck limiting the switch capacity. The priority handling in arbitration is also addressed. Copyright © 2001 John Wiley & Sons, Ltd.
A comparison of congestion control and time slot algorithms in Internet transmission performance
Authors: Yang Chyan , Fu Chen‐Hua
Published: August 2002

The characteristics of TCP and UDP lead to different network transmission behaviours. TCP is responsive to network congestion whereas UDP is not. This paper proposes two mechanisms that operate at the source node to regulate TCP and UDP flows and provide a differential service for them. One is the congestion‐control mechanism, which uses congestion signal detected by TCP flows to regulate the flows at the source node. Another is the time‐slot mechanism, which assigns different number of time slots to flows to control their flow transmission. Based on the priority of each flow, different bandwidth proportions are allocated for each flow and differential services are provided. Simulation results show some insights of these two mechanisms. Moreover, we summarize the factors that may impact the performance of these two mechanisms. Copyright © 2001 John Wiley & Sons, Ltd.
Significance of the cytologic diagnosis of endocervical glandular involvement in high‐grade squamous intraepithelial lesions
Authors: Levine Pascale Hummel , Waisman Jerry , Mittal Khush
Published: August 2002

The cytologic criteria for the diagnosis of endocervical gland involvement (EGI) by high‐grade squamous intraepithelial lesions (HGSILs) have been described, and this diagnosis occasionally is made. This study evaluates the accuracy of a cytologic diagnosis compared with that of follow‐up cone biopsies. Twenty‐eight patients with Papanicolaou (Pap) smear diagnoses of HGSILs with EGI, with follow‐up cone biopsies, were identified from New York University computerized files. Results were compared with those of a control group of 28 patients showing cervical intra‐epithelial neoplasia grades II/III (CIN‐II/III), irrespective of previous Pap smear findings. On subsequent cone biopsy samples, 26 of the 28 study cases showed signs of HGSIL. Of these 26 patients, 17 (65%) showed evidence of HGSIL with EGI. Among the 28 control cases, 20 (71.4%) had EGI on the cone biopsies (P = NS). We also examined previous Pap smear findings in a control group of 42 cone biopsies with CIN‐II or CIN‐III, with or without EGI. EGI was diagnosed in previous Pap smears in 3 of the 31(10%) cases that showed signs of EGI on cone biopsies and in 2 of the 11 cases (18%) that did not evidence EGI on subsequent cone biopsies (P = NS). In our experience, the cytologic diagnosis of EGI on Pap smears did not identify a group of patients with increased frequency of EGI on subsequent cone biopsies. Diagn. Cytopathol. 2002;26:217–221. © 2002 Wiley‐Liss, Inc.
Radiologically guided percutaneous fine‐needle aspiration biopsy of the liver: Retrospective study of 119 cases evaluating diagnostic effectiveness and clinical complications
Authors: Guo Ziwen , Kurtycz Daniel F.I. , Salem Riad , De Las Casas Luis E. , Caya James G. , Hoerl H. Daniel
Published: August 2002

We reviewed 119 percutaneous, radiologically guided fine‐needle aspirations (FNA) from 114 patients with liver masses to evaluate diagnostic effectiveness and complications of this procedure. Satisfactory material was obtained in 118 cases (99%), of which 78 were diagnosed as positive (66%), three suspicious (2%), five atypical (4%), and 32 (27%) as negative for malignancy. Compared to surgical biopsy (48 cases) and clinical data, the sensitivity and specificity of FNA for malignancy was 95.1% and 100%, respectively, yielding a positive predictive value of 100% and a negative predictive value of 88.8%. Four cytology cases (3.4%) were false‐negatives (FN); all were interpretive errors. Four FN surgical biopsies (8.3%) were sampling errors. Minor complications occurred in three cases (2.5%). We conclude that FNA is safe and effective for determining the malignant potential of liver masses and should be the procedure of choice. Our experience suggests that having a pathologist present in the radiology suite provides optimal patient care. Diagn. Cytopathol. 2002;26:283–289. © 2002 Wiley‐Liss, Inc.
Changing clinical course of patients with malignant mesothelioma: Implications for FNA cytology and utility of immunocytochemical staining
Authors: Yu Gordon H. , Soma Lori , Hahn Stephen , Friedberg Joseph S.
Published: August 2002

The diagnosis of both local recurrences and distant metastases of mesothelioma can be accomplished by fine‐needle aspiration (FNA) biopsy. Although the previous history of mesothelioma provides strong support for recurrent/metastatic mesothelioma, other diagnostic possibilities (particularly adenocarcinoma) may require exclusion via special stains in some cases. In this study, we report on the morphologic findings in 13 cases of mesothelioma which underwent FNA (7 metastatic lesions, 6 local recurrences). In addition, immunohistochemical staining results for 7 cases with available material using antibodies directed against cytokeratin AE 1/3 and two antibodies reported to show consistently positive results in mesothelioma (calretinin and cytokeratin 5/6) are reported and compared to results seen for 10 cases of adenocarcinoma. All cases of mesothelioma and adenocarcinoma showed strong staining with cytokeratin AE 1/3. Three of 7 cases of mesothelioma showed strong staining with calretinin, while only focal staining was detected in 3 additional cases; only one case showed positive staining with cytokeratin 5/6. One of 10 cases of adenocarcinoma showed calretinin positivity; however, at least focal staining with cytokeratin 5/6 was seen in 4 cases. These results suggest that cytokeratin 5/6 is neither a sensitive nor specific stain for the diagnosis of mesothelioma in cytology material. Calretinin appears to be more specific for mesothelioma but showed disappointing sensitivity for this tumor, potentially limiting its diagnostic utility in FNA material. Diagn. Cytopathol. 24:322–327, 2001. © 2001 Wiley‐Liss, Inc.
Spindle‐cell lesions of the liver: Diagnosis by fine‐needle aspiration biopsy
Authors: Guy Cynthia D. , Yuan Shan , Ballo Michael S.
Published: August 2002

Rarely, spindle‐cell lesions in liver fine‐needle aspiration biopsies (FNABs) are encountered. A retrospective review of our experience with lesions that are mesenchymal in origin or appearance was undertaken to elucidate the frequency and spectrum of these lesions. Image‐guided liver FNABs performed over a 3‐year period (n = 585) at our institution (1996–1998) were retrospectively evaluated. Cytologic smears, cell block preparations, and clinical follow‐up of lesions with spindle‐cell morphology were reviewed. Twenty‐nine of 585 cases were of spindle‐cell morphology (5%). Hemangiomas (n = 12, 41%) and metastatic sarcomas (n = 6, 21%) comprised the largest categories, followed by granulomatous inflammation (n = 3, 10%). Other cases included primary angiosarcoma and fibrolamellar hepatocellular carcinoma. The most frequent spindle‐cell liver lesion encountered is hemangioma, followed by metastatic leiomyosarcoma and granulomatous hepatitis. Awareness of diagnostic possibilities, special attention to specimen adequacy, and use of ancillary procedures can maximize diagnostic yield. Diagn. Cytopathol. 2001;25:94–100. © 2001 Wiley‐Liss, Inc.
Primary malignant melanoma of the uterine cervix: Report of a case diagnosed by cervical scrape cytology and review of the literature
Authors: Deshpande Archana H. , Munshi Maitreyee M.
Published: August 2002

Cervical melanoma is a rare neoplasm and is seldom diagnosed by cervical scrape cytology. The possibility of metastatic melanoma should be excluded before making a diagnosis of primary cervical melanoma. We present a case of primary cervical melanoma diagnosed by cervical scrape cytology and a review of literature. The patient presented with vaginal bleeding of 3 mo duration and an ulcerated cervical growth. Cervical smear showed bizarre and abnormal cells containing pigment. Diagn. Cytopathol. 2001;25:108–111. © 2001 Wiley‐Liss, Inc.
Lymph node cytology in Wegener's granulomatosis
Authors: Banerjee Anindo K. , Tungekar Muhammad F. , Derias Nawal
Published: August 2002

We report on cytological findings on aspirates from the cervical lymph node from a case of Wegener's granulomatosis (WG). The diagnostic utility of technique in diagnosing a sizable minority of WG patients who present with cervical lymphadenopathy is discussed. We outline an approach to diagnosis of necrotising granulomatous lesions in aspirates from lymph nodes in a tabular form. Diagn. Cytopathol. 2001;25:112–114. © 2001 Wiley‐Liss, Inc.
Fine‐needle aspiration cytology of pancreatoblastoma
Authors: Henke Andrew C. , Kelley Carolyn M. , Jensen Chris S. , Timmerman Timothy G.
Published: August 2002

Pancreatoblastoma is a rare pancreatic neoplasm seen most commonly in the pediatric age group. We report on the aspiration cytology and immunohistochemical findings of a pancreatoblastoma in a 16‐yr‐old male. Diagn. Cytopathol. 2001;25:118–121. © 2001 Wiley‐Liss, Inc.
Cytologic features of disseminated bacillus Calmette‐Guérin (BCG) infection
Authors: Cohen Marta , Drut Ricardo
Published: August 2002

Disseminated bacillus Calmette‐Guérin (BCG) infection is an unusual complication of immunization against Mycobacterium tuberculosis with the bacillus Calmette‐Guérin. We report on 4 such cases in which the diagnosis was suspected at the fine‐needle aspiration biopsy (FNAB) procedure. Participants were 4 males (mean age, 21.5 mo; range, 8–36 mo) in good general condition, in whom epidemiology data favoring tuberculosis and presence of pulmonary tuberculosis were lacking. Cases 1 and 2 presented with a deep‐seated subcutaneous nodule located near the left mamilla and lower aspect of the left scapula, respectively, resulting from lymph node involvement by BCG. Cases 3 and 4 presented as an osteolytic lesion of the ninth right rib and right iliac bone, respectively. FNAB findings showed poorly to moderately cellular smears. Epithelioid histiocytes in a granuloma pattern with occasional multinucleated Langerhans‐type giant cells, lymphocytes, and polymorphonuclear leukocytes in a finely granular background with necrotic debris were found in all cases. The presence of isolated calcified spherules interspersed among the cells was found to be a useful finding for diagnosis. When dealing with disseminated BCG infections, clinical and cytological pictures must be evaluated as a whole in order to arrive at an accurate diagnosis. Diagn. Cytopathol. 2001;25:134–137. © 2001 Wiley‐Liss, Inc.
Pharmacodynamics and pharmacokinetics of YM128, a GPIIb/IIIa antagonist prodrug
Authors: Suzuki Ken‐ichi , Moritani Yumiko , Hisamichi Nami , Ichihara Masato , Akamatsu Seijiro , Arai Hiroshi , Matsushima Hiroshi , Nii Tomoko , Sato Kazuo , Taniuchi Yuta , Shigenaga Takeshi , Kaku Seiji , Kawasaki Tomihisa , Matsumoto Yuzo , Inagaki Osamu , Tomioka Kenichi , Yanagisawa Isao
Published: August 2002

We examined the biochemical properties of YM‐57029 ({4‐[4‐(4‐Carbamimidoylphenyl)‐3‐oxopiperazin‐1‐yl]piperidino}acetic acid monohydrochloride trihydrate) and the pharmacodynamics and pharmacokinetics of its prodrug, YM128 (Ethyl (Z)‐(4‐{4‐[4‐(N2‐hydroxycarbamimidoyl)phenyl]‐3‐oxopiperazin‐1‐yl}piperidino)acetate), an orally‐active glycoprotein IIb/IIIa (GPIIb/IIIa) antagonist. YM‐57029 strongly inhibited aggregation of human platelets induced by various agonists, with IC50 values ranging from 3.6 to 51 nM. YM‐57029 specifically inhibited fibrinogen binding to purified GPIIb/IIIa about 1,000‐fold more potently than Arg‐Gly‐Asp‐Ser (RGDS). Moreover, YM‐57029 effectively inhibited an Arg‐Gly‐Asp (RGD) peptide binding to platelets, suggesting that YM‐57029 competed with the RGD sequence of ligand. YM‐57029 or YM128 dose‐dependently inhibited ex vivo platelet aggregation after iv bolus injection or oral administration to beagle dogs and cynomolgus monkeys. However, YM128 exerted more potent and prolonged inhibitory effects on platelet aggregation than YM‐57029 after oral administration to cynomolgus monkeys. Furthermore, YM‐57029 prolonged template bleeding time at a dose that inhibited ex vivo platelet aggregation during cumulative iv infusion to cynomolgus monkeys. Metabolic and pharmacokinetic studies showed that YM128 effectively converted into YM‐57029 in liver microsomes from humans as well as dogs and monkeys, and that bioavailabilities of YM128 in dogs and monkeys were 32.3 and 22.2%, respectively. These results suggest that YM128, a prodrug of YM‐57029, may be a valuable GPIIb/IIIa antagonist with good bioavailability in humans. Drug Dev. Res. 55:149–161, 2002. © 2002 Wiley‐Liss, Inc.
Dipyrone inhibits ethanol withdrawal and pentylenetetrazol‐induced seizures in rats
Authors: Ergün Hakan , Uzbay İ Tayfun , Çelik Turgay , Kayir Hakan , Yeşilyurt Özgür , Tulunay F. Cankat
Published: August 2002

The effects of dipyrone, a nonnarcotic analgesic drug, on ethanol withdrawal and pentylenetetrazol (PTZ)‐induced seizures in male Wistar rats were investigated. Ethanol (7.2%) was given to rats by a liquid diet for 21 days. After 6 h of ethanol withdrawal, rats were exposed to an audiogenic stimulus (100 dB) for 60 sec for induction of seizures. Dipyrone (50, 100, and 200 mg/kg ip) and saline were administered to rats 30 min before audiogenic stimulus, and the effects of dipyrone on the seizures induced by audiogenic stimulus were evaluated. The effects of dipyrone on PTZ‐induced seizures were also evaluated in other individual groups of the rats. The same doses of dipyrone were injected in the rats ip 30 min before PTZ (50 mg/kg) injections. Immediately after PTZ injections, onset time and severity of the convulsions were recorded. Dipyrone significantly and dose‐dependently reduced both incidence and intensity of the ethanol withdrawal‐associated audiogenic seizures. It also inhibited significantly and dose‐dependently intensity but not onset time of the PTZ‐induced seizures. Dipyrone (50–200 mg/kg) did not produce any significant change in locomotor activity in naive rats. Our results suggest that dipyrone has some prominent anticonvulsant activities on both ethanol withdrawal and PTZ‐induced seizures in rats, and that using dipyrone may be a new and effective therapeutic approach in the treatment of seizures. Drug Dev. Res. 53:254–259, 2001. © 2001 Wiley‐Liss, Inc.
Role of COX‐1‐ and COX‐2‐synthesized prostaglandins in a rat model of arthritic pain
Authors: Martínez Rosa Ventura , Díaz M. Irene , Hernández G. Patricia , Ramírez Adriana M. Domínguez , Salazar Luis A. , Cabré Francesc , López‐Muñoz Francisco J.
Published: August 2002

An appropriate animal model for investigation of antiinflammatory analgesic effects of NSAIDs is the pain‐induced functional impairment model in the rat (PIFIR model). The PIFIR model provides a model of inflammatory and chronic pain similar to that of clinical gout. We investigated the possible role of peripheral prostaglandins synthesized by COX‐1 and COX‐2 in arthritic pain produced by uric acid in the rat PIFIR model. For this purpose, the antinociceptive effects of indomethacin, a nonselective COX‐1/COX‐2 inhibitor, and those of SC‐560 and MK‐966 (Vioxx), selective inhibitors of COX‐1 and COX‐2, respectively, on the functional impairment induced by intraarticular (i.a.) injection of uric acid into the knee joint of the right hindlimb were compared. The antinociceptive efficacy was determined from the area under the curve (AUC) values obtained from the time course of the antinociceptive effect. Animals received vehicle, 100 μg indomethacin, 100 μg SC‐560, or 50 μg of MK‐966 (these drug doses were selected from dose–response curves of each drug in previous experiments) 20 min before uric acid and the ability of the rat to use the injured hindlimb was recorded with a computerized system. The effect produced by each treatment was compared with that observed after the compounds were administered in the left hindlimb, i.e., contralateral administration. The results showed that all three compounds significantly inhibited uric acid‐induced dysfunction of the right hindlimb (control = 64 ± 8 au; indomethacin = 391 ± 30 au; MK‐966 = 368 ± 17 au; SC‐560 = 445 ± 25 au, ANOVA, Dunnett’s test, P < 0.01). In addition, the results using contralateral administration suggest that the analgesic effect was due to inhibition of locally produced COX‐1 and COX‐2 and, therefore, that no central mechanisms were involved. Taken together, the present data using the pain‐induced functional impairment model in rats support the idea that both COX isoforms (1 and 2) contribute to the local inflammatory response in the model and that they may have a role in the maintenance of physiological homeostasis. They might also suggest that the therapeutic benefits of NSAIDs are mainly due to inhibition of both COX isoforms. Drug Dev. Res. 51:253–259, 2000. © 2001 Wiley‐Liss, Inc.
The interaction of age and unconditioned stimulus intensity on long‐trace conditioned flavor aversion in rats
Authors: Misanin James R. , Goodhart Mark G. , Anderson Matthew J. , Hinderliter Charles F.
Published: August 2002

To see if the neural representation of the conditioned stimulus (CS) is available to old‐age rats beyond the time it is available to young adults, the intensity of the unconditioned stimulus (US) and the length of the CS–US interval were systematically varied in a trace conditioning experiment. Results indicated that increasing US intensity extends the interval over which trace conditioning is evident in old‐age rats but not in young adults, suggesting that trace decay occurs more rapidly in young rats. Results were interpreted in terms of age differences in the workings of hypothesized biochemical timing mechanisms that may directly influence the ability to associate stimuli over trace intervals in conditioned taste‐aversion procedures. © 2002 Wiley Periodicals, Inc. Dev Psychobiol 40: 131–137, 2002. DOI 10.1002/dev.10018
Effects of the uterine environment and neocortical ectopias upon behavior of BXSB‐Yaa+mice
Authors: Denenberg Victor H. , Hoplight Blair , Sherman Gordon F. , Mobraaten L. E.
Published: August 2002

Between 40–60% of BXSB‐Yaa+mice have neocortical ectopias, a genetically based brain anomaly. The presence of ectopias is known to affect several cognitive measures. A second way to affect cognition is by transferring embryos into foreign uteri. These variables were jointly investigated in three experiments. BXSB‐Yaa+mouse embryos were transferred into same‐strain uteri, or into uteri of hybrid mice. At birth, pups were cross‐fostered to hybrid mothers or were reared by their birth mothers. When adult, the mice were given a series of behavioral tests with primary emphasis upon cognitive competence. Across all three studies, mice transferred into hybrid uteri were superior in the Morris maze and the Lashley III maze, and performed more effectively in shuttlebox avoidance learning. They were less effective in the simple water escape task, and the uterus groups did not differ in discrimination learning. Thus, development within a foreign uterus enhanced spatial learning and fear‐based conditioning. Ectopic mice were superior to non‐ectopics in learning the Morris maze, a finding consistent with prior research using the congenic BXSB‐Yaa strain. There were Uterus × Ectopia interactions on a few measures, indicating that, under certain condition, whether the presence of ectopias is beneficial or detrimental is contingent upon the uterine environment within which the organism develops. © 2001 John Wiley & Sons, Inc. Dev Psychobiol 38: 154–163, 2001
Formation and maintenance of distinctive cell patterns by coexpression of membrane‐bound ligands and their receptors
Authors: Honda Hisao , Mochizuki Atsushi
Published: August 2002

We show that graded or checkerboard‐like cell patterns, and segmental domains along a body axis, can be generated by cell behaviors involving differences in intercellular repulsion. A membrane‐bound signal transduction system mediating contact‐dependent cell interactions includes membrane‐bound ligands (ephrins) and their receptors with tyrosine‐kinase activity (Eph proteins). These molecules mediate both repulsive and attractive interactions under bilateral threshold control, i.e., cells expressing the receptors adhere to a surface bearing a critical density of ligand reciprocal to the density of receptor but are repelled by a surface with other densities of ligand (Honda [1998] J. Theor. Biol. 192:235–246). We extend this model. General membrane‐bound ligands (not always ephrins) and their receptors are presumably coexpressed in a single cell under bilateral threshold control. Computer simulations of cell pattern formation showed that when coexpression of the ligand and receptor is reciprocal, the cells self‐organize into a pattern of segmental domains or a graded cell arrangement along the body axis. The latter process interprets positional information in terms of protein molecules. When coexpression of the two species of molecules is not always reciprocal, the cells generate various patterns including checkerboard and kagome (star) patterns. The case of separate expression of ligands and receptors in different cells is also examined. The mechanism of differences in cell repulsion is compared with the differential cell adhesion hypothesis, which has been used to explain cell sorting. © 2002 Wiley‐Liss, Inc.
Postnatal Msx1 expression pattern in craniofacial, axial, and appendicular skeleton of transgenic mice from the first week until the second year
Authors: Orestes‐Cardoso Silvana Maria , Nefussi Jean Raphael , Hotton Dominique , Mesbah Mohand , Orestes‐Cardoso Maria Do Socorro , Robert Benoît , Berdal Ariane
Published: August 2002

Phenotypes associated with Msx1 mutations have established the prominent role of this divergent homeogene in skeletal patterning. Previous studies have been achieved during antenatal development in relation with the early death of null mutant mice. Therefore, the present study is devoted to Msx1 homeogene in the postnatal craniofacial, axial, and appendicular skeleton. A knock‐in transgenic mouse line was studied from the first postnatal week until 15 months. Whole‐mount β‐galactosidase enzymology identified Msx1 protein expression pattern. Maintained expression of Msx1 was observed in growing and adult mice, specifically in the sites where Msx1 plays an early morphogenetic role during initial skeletal patterning. These included the craniofacial sutures, autopodium, mandible, and alveolar bone. Furthermore, active membranous and endochondral bone formation involved Msx1 in the entire skeleton. Histologic sections showed that progenitor as well as differentiating and differentiated cells of all the bone cell lineages could express the Msx1 protein (chondrocytes, osteoblasts, tartrate‐resistant acid phosphatase positive osteoclasts and chondroclasts). Recent developments in the genetic and developmental biology of skeletal morphogenesis demonstrate that genes critical for development are jointly expressed in discrete embryonic signalling and growth centers, the enamel knot in teeth, the cranial suture in skull morphogenesis, and the progress zone in the limb buds. The present study suggests that these signalling pathways are jointly important throughout the entire lifetime with an exquisite site‐specificity spatially related to early patterning. © 2001 Wiley‐Liss, Inc.
Investigation of Prx1 protein expression provides evidence for conservation of cardiac‐specific posttranscriptional regulation in vertebrates
Authors: Chesterman Elizabeth S. , Gainey Georgina D. , Varn Allyson C. , Peterson Richard E. , Kern Michael J.
Published: August 2002

Gene targeting experiments have defined that the homeobox gene Prx1 is essential for normal craniofacial, limb, and vascular development. Although its RNA expression pattern is well established, Prx1 protein expression in the developing embryo has not been examined. A novel Prx1 antibody was produced to define the normal Prx1 protein expression pattern in the developing mouse embryo. In craniofacial and limb mesenchyme, Prx1 protein expression is consistent with previously published data on RNA localization. However, a remarkable discrepancy was found in cardiac tissue. Prx1 protein is undetectable in the murine embryonic and adult heart, despite the presence of Prx1 transcripts. These data demonstrate that Prx1 expression is posttranscriptionally regulated. This discrepancy between the presence of Prx1 transcript and the absence of detectable protein was also observed in embryonic chick heart, suggesting conservation of the regulatory mechanism in vertebrates. This observation provides a new explanation of why the Prx null mice lack cardiac malformations. © 2001 Wiley‐Liss, Inc.
Identification, cloning, and developmental expression of hepatoma‐derived growth factor in the developing rat heart
Authors: Everett Allen D.
Published: August 2002

Hepatoma derived growth factor (HDGF) was identified as a developmentally regulated cardiac gene by mRNA differential display using 12‐day rat fetal conotruncus vs. newborn aorta. The full‐length rat HDGF cDNA was cloned from a rat fetal heart cDNA library and found to be 94 and 88% homologous to the mouse and human sequence, respectively. The rat sequence, like the human and mouse, contains a highly conserved amino portion and putative bipartite nuclear localization sequence. By Northern analysis, HDGF is highly expressed in the fetal conotruncus, heart, kidney, brain, and gut. By immunocytochemistry, HDGF was first detected only in atrial myocytes, hind gut epithelia, and notochord of the E10 rat with a nuclear expression pattern. By E12, expression had broadened to include the ventricular myocytes, endocardial cells, and cells of the ventricular outflow tract. HDGF is unique in that it is the first described nuclear targeted growth factor in the developing heart. The early expression of HDGF in embryonic heart and fetal gut suggests that HDGF may play a role in cardiovascular growth and differentiation. © 2001 Wiley‐Liss, Inc.
Neural induction takes a transcriptional twist
Authors: Bainter Jennifer J. , Boos Aline , Kroll Kristen L.
Published: August 2002

Over the past decade, several molecules have been identified that influence neural cell fate in vertebrate embryos during gastrulation. The first neural inducers studied were proteins produced by dorsal mesoderm (the Spemann organizer); most of these proteins act by directly binding to and antagonizing the function of bone morphogenetic proteins (BMPs). Recent experiments have suggested that other secreted signals, such as Wnt and FGF, may neuralize ectoderm before organizer function by a different mechanism. Neural effector genes that mediate the response of ectoderm to secreted neuralizing signals have also been discovered. Interestingly, most of these newly identified neuralizing pathways continue the theme of BMP antagonism, but rather than antagonizing BMP protein function, they may neuralize tissue by suppressing Bmp expression. Down‐regulation of Bmp expression in the prospective neural plate during gastrulation seems to be a shared feature of neural induction in vertebrate embryos. However, the signals used to accomplish this task seem to vary among vertebrates. Here, we will discuss the role of the recently identified secreted signals and neural effector genes in vertebrate neurogenesis. © 2001 Wiley‐Liss, Inc.
Vascular regression is required for mesenchymal condensation and chondrogenesis in the developing limb
Authors: Yin Melinda , Pacifici Maurizio
Published: August 2002

Vascular regression occurs during limb mesenchymal cell condensation and chondrogenesis, but it is unclear whether it is required for these processes or is a secondary phenomenon without major regulatory roles. To address this issue, beads presoaked with the potent angiogenic factor vascular endothelial growth factor (VEGF) were implanted in the vicinity of the prospective digit 2 in early chick embryo wing buds and the effects on angiogenesis and digit development were determined over time. We found that VEGF treatment caused a marked local increase in blood vessel number and density. Strikingly, this was accompanied by inhibition of digit 2 development as revealed by lack of expression of chondrogenic transcription factor Sox9 and absence of Alcian blue staining. Vascular distribution and skeletal development in adjacent areas remained largely unaffected. Inhibition of digit formation and excess vascularization were both reversible upon further embryonic growth and dissipation of VEGF activity. When supernumerary digits were induced at the anterior limb margin by retinoic acid treatment, their development was also preceded by vascular regression; interestingly, cotreatment with VEGF inhibited supernumerary digit development as well. Direct exposure of limb mesenchymal cells in micromass cultures to VEGF caused no obvious effects on condensation and chondrogenesis, indicating that VEGF effects are not due to direct action on skeletal cells. Our results are the first to provide evidence that vascular regression is required for mesenchymal condensation and chondrogenesis. A model of how patterning mechanisms and vascular regression may intersect and orchestrate limb skeletogenesis is proposed. © 2001 Wiley‐Liss, Inc.
Eating disorder symptomatology is not associated with pregnancy and perinatal complications in a cohort of adolescents who were born preterm
Authors: Feingold Ellen , Sheir‐Neiss Geraldine , Melnychuk Jennifer , Bachrach Steven , Paul David
Published: August 2002

Objective

We attempt to resolve the question of whether pregnancy complications and perinatal trauma, including brain insults, in premature infants increase the susceptibility to eating disorder symptomatology during the adolescent years.

Method

This study uses a historical, prospective methodology to investigate the 84 members of a cohort of infants born prematurely (<33 weeks gestation) at Thomas Jefferson University Hospital during a 25‐month period, from 1979 to 1981. We extracted the following information from their neonatal intensive care unit (NICU) records: ultrasound examination findings (graded on intraventricular hemorrhage [IVH] and periventricular leukomalacia [PVL]), records of pregnancy complications and perinatal trauma, and medical problems during the NICU stay. This method eliminated recall bias, a problem with previous studies. We followed up the members of this cohort, obtaining data on 53 (63%). We correlated the NICU data with the following outcome measures: physical measurements and psychosocial, psychological, and eating disorder symptomatology data obtained by self‐report questionnaires. Pregnancy and perinatal complications were combined into one composite variable. We used the method of multiple discriminant function analysis to determine statistical significance between groups.

Results

There were no statistically significant differences between the low (0–2) and high (3–7) composite variable of pregnancy/perinatal complications and outcome variables.

Conclusions

These results indicate that traumatic episodes early in life, including brain insults, do not appear to increase the susceptibility of developing eating disorder symptomatology, depression, deficiency of self‐esteem, or distortion of body shape during late adolescence. © 2002 by Wiley Periodicals, Inc. Int J Eat Disord 31: 202–209, 2002; DOI. 10.1002/eat.10021
Social anxiety as a barrier to treatment for eating disorders
Authors: Goodwin Renee D. , Fitzgibbon Marian L.
Published: August 2002

Background

The goal of this pilot investigation is to determine the relationship between social anxiety and treatment‐ seeking behavior for eating disorders in an outpatient psychiatric clinic.

Method

Twenty‐eight patients seeking treatment for anorexia or bulimia at an outpatient eating disorders clinic completed a battery of self‐report measures on eating pathology, attachment style and functioning, and social anxiety at initial intake appointment. Levels of eating pathology and social anxiety at consult were compared with service utilization records on entry into treatment.

Results

Individuals who did not engage in treatment had significantly higher levels of social anxiety (F = 8.29, df = 1, p < .05) compared with those who did engage in treatment. There were no differences in demographic characteristics, diagnoses, or level of eating pathology at intake.

Conclusions

Social anxiety may act as a barrier to effective helpseeking and utilization of mental health treatment among individuals with eating disorders. Replication of these findings in a larger sample and more in‐depth study of the mechanism of the observed association between use of services and social anxiety may be useful in planning more effective outreach in the community to underserved populations in need of treatment for eating disorders. © 2002 by Wiley Periodicals, Inc. Int J Eat Disord 32:103–106, 2002.
Binge eating and other psychopathology in patients with type II diabetes mellitus
Authors: Crow Scott , Kendall David , Praus Barbara , Thuras Paul
Published: August 2002

Objective

Type II diabetes mellitus (DM), a common disease with many potential complications, is strongly associated with obesity. Alterations in food consumption can dramatically alter glucose control in individuals with Type II DM. Binge eating disorder (BED) is also closely associated with obesity. The nature of the relationship, if any, between Type II DM and BED is unclear.

Methods

Forty‐three individuals (23 females, 20 males) with Type II DM were assessed using the Structured Clinical Interview for DSM‐IV (SCID‐I), the Three‐Factor Eating Questionnaire (TFEQ), and the Impact of Weight Scale. The most recent hemoglobin A1c level was recorded. Height and weight were also measured.

Results

Eleven subjects (25.6%) were diagnosed with BED. Individuals with BED had higher body mass index (BMI) scores, higher TFEQ Disinhibition and Hunger scores, and higher scores on all Impact of Weight subscales (except eating) compared with those without BED. Glycosylated hemoglobin levels did not differ between the two groups (8.1% vs. 8.4%; p = 0.553).

Discussion

Rates of BED in subjects with Type II DM were substantial. Other types of psychopathology were also common. Although glycosylated hemoglobin levels were similar in patients with and without BED, the presence of BED was associated with greater obesity. Assessment for BED is an important aspect of the management of patients with Type II DM. © 2001 by John Wiley & Sons, Inc. Int J Eat Disord 30: 222–226, 2001.
Is family‐based behavioral weight control appropriate for severe pediatric obesity?
Authors: Levine Michele D. , Ringham Rebecca M. , Kalarchian Melissa A. , Wisniewski Lucene , Marcus Marsha D.
Published: August 2002

Objective

Although the efficacy of family‐based behavioral treatment for moderate pediatric obesity has been well established, few studies have focused on the treatment of severe obesity. We sought to evaluate the acceptability and feasibility of a family‐based intervention for severely obese children.

Method

Twenty‐four families with children aged 8–12 years who were ≥160% of their ideal body weight participated in a 10–12‐session behavioral intervention. Participants were weighed and their heights measured at the start of each treatment session and during a follow‐up visit 4–13 (M = 7.8) months posttreatment. Children also completed measures of depressive symptoms and anxiety at pretreatment, posttreatment, and follow‐up, and eating attitudes were assessed at pretreatment and follow‐up.

Results

One third of the families did not complete treatment. However, children who completed the program lost a significant amount of weight and reported significant improvements in depression, anxiety, and eating attitudes that were maintained over time.

Discussion

A short‐term, family‐based behavioral intervention was successful in moderating weight gain for most children and had positive effects on children's mood and eating disorder symptoms. Future randomized, controlled trials of longer interventions are necessary to determine the success of this approach. © 2001 by John Wiley & Sons, Inc. Int J Eat Disord 30: 318–328, 2001.
A data channel reservation protocol for high‐speed processing in WDM single‐hop networks
Authors: Tamura Tomofumi , Takahara Mikio , Hanawa Masanori
Published: August 2002

In WDM single‐hop networks, a data channel reservation protocol to transmit variable‐sized messages efficiently has been proposed. Networks have some data channels and a control channel to assign a data channel in the protocol. A timeslot of the control channel consists of several minislots and a round‐trip propagation delay time between a node and the star coupler. Under the condition of long transmission distance or high bit rate, the round‐trip propagation delay time is longer than the minislot part in a timeslot and consequently the throughput characteristics are degraded. In this paper, we propose a protocol to transmit variable‐sized messages efficiently even under the above condition. In the proposed protocol, a permitted transmission timeslot (PTS) is set to transmit a control packet every (R + 1) timeslots, and a data channel is assigned to each transmitting node every (R + 1) timeslots where R is the propagation delay time normalized to the timeslot length. Then the performance of the proposed protocol is compared with that of the conventional one by computer simulation. The simulation results improved the throughput by about 30% at a message arrival rate of 0.4 message/timeslot/node and showed that the proposed protocol is useful under the above conditions. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 85(11): 13–19, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10013