bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence of oral mucosal lesions in alcohol misusers in south London
Authors: Harris C. K. , Warnakulasuriya K. A. A. S. , Cooper D. J. , Peters T. J. , Gelbier S.
Published: April 2004

Background:  Information on alcohol‐associated oral mucosal lesions (OMLs) and conditions is meagre. A prevalence survey among alcohol misusers in south London was therefore undertaken.

Methods:  Six hundred and ninety‐three subjects (388 alcohol misusers and 305 alcohol + substance abuse) attending several clinical care facilities in south London between 1994 and 1999 were interviewed on their alcohol and drug habits. A comprehensive oral mucosal examination was performed, and soft tissue lesions found were classified by the clinical criteria of Axéll.

Results:  Mean age of the sample was 40.5 years. The majority was white (92.6%); of the whites, 29.9% were Celts (i.e. Irish, Scots resident in London). Many subjects reported misusing more than one type of beverage. Two hundred and twenty‐seven OMLs were found in 195 subjects (28.1%). The highest prevalences were found for frictional keratosis (8.8%), scar tissue of the lips (4.8%) and candidiasis (3.8%). Angular cheilitis was present in 21 subjects (3.0%). The alcohol‐related OMLs detected were three white patches compatible with a diagnosis of leukoplakia and one treated oral carcinoma. No erythroplakias were detected. The differences in prevalence of mucosal lesions in the two groups were not significant (χ2 = 2.18; P = 0.14). The prevalence of tobacco smoking was high in both study groups. OMLs were found with all four types of beverages consumed, and there was little variation by the units per week consumed. Concurrent use of substances and alcohol did not make a significant difference to the prevalence of OML. In the logistic regression analysis, minority ethnic groups (Black or Asian), smokers, those with a body mass index (BMI) under 20 and beer drinkers had an increased risk of an OML in this group of alcohol misusers.

Conclusions:  In comparison with previous oral mucosal screening programmes undertaken in several settings in the UK, the present study has yielded a higher prevalence of oral mucosal diseases and conditions in this risk population. There are several ways in which alcohol could contribute to these detected oral lesions, either directly or indirectly.
Human papillomavirus frequency in oral epithelial lesions
Authors: Lazzari Carmen Maria , Krug Luciano Percival , Quadros Onofre Francisco , Baldi Cristiano Bozzetti , Bozzetti Mary Clarisse
Published: April 2004

Background:  Oral human papillomavirus (HPV) prevalence varies according to geographical occurrence, the type of lesion, and the method of diagnosis. The polymerase chain reaction method (PCR) appears to be more sensitive and can be easily applicable to epidemiologic studies.

Objectives:  To determine the frequency of HPV and its genotypes in oral lesions among patients attending a reference clinic of a university hospital.

Methods:  PCR was performed to identify HPV DNA from samples of oral epithelial lesions in 80 patients. For HPV DNA amplification, MY09/MY11 consensus primers were used and specific genotypes were identified through restriction fragment of length polymorphism (RFLP) pattern.

Results:  HPV DNA was present in 11.3% of patients, and the identified genotypes were 6b, MM4 (W13B), and MM9 (PAP238A).

Conclusions:  HPV DNA frequency in patients with oral epithelial lesions was 11.3%. The genotypes MM4 and MM9 are uncommon in oral lesions, and they are characterized as high‐risk HPV types in those types of lesions.
Delayed cutaneous reactions to heparin in antiphospholipid syndrome during pregnancy
Authors: Kim Jessica , Smith Kathleen J. , Toner Charles , Skelton Henry
Published: April 2004

Background  Clinical symptoms related to antiphospholipid antibodies often first occur during pregnancy with the diagnosis of antiphospholipid syndrome (APS). Unfractionated heparin (UFH) and low‐dose aspirin are considered as first‐line treatments for pregnant women with APS and recurrent fetal loss. However, in addition to an increased incidence of hemorrhagic side‐effects and thrombocytopenia there are a number of drug eruptions with cutaneous components secondary to the use of UFH. One of these eruptions has been classified as a delayed type I.V. hypersensitivity reactions at the sites of UFH injections. The majority of these reactions occur in pregnant women.

Method  We present three pregnant patients who developed delayed hypersensitivity reactions at the sites of UFH injections. Two patients had documented APS and the other patient had two previous spontaneous abortions.

Results  The histopathologic and immunohistochemical findings in the biopsy specimens from the sites of the delayed reactions were distinctive. The inflammatory infiltrate contained CD3+ and CD4+ lymphoid cells with plasma cells, and eosinophils. There was a marked increased in mast cells with increased stromal cells within the dermis and increased vascular proliferation.

Conclusions  The distinctive histopathologic and immunohistochemical features seen in the delayed hypersensitivity reactions at the sites of UFH injections may be modulated by the immunomodulatory effects of UFH as well as the hormonal levels and cytokine patterns during pregnancy. Alternative therapies may not always be successful in resolving the reactions.
Prevalence of dermatological disorders in Thai HIV‐infected patients correlated with different CD4 lymphocyte count statuses: a note on 120 cases
Authors: Wiwanitkit Viroj
Published: April 2004

Background  Skin disease is one health problem among human immunodeficiency virus (HIV)‐seropositive patients. Several dermatological findings in HIV‐infected patients have been investigated. In this study, the skin lesions of 120 HIV‐infected patients with different CD4 count statuses in Bangkok, Thailand, are studied.

Methods  This study was performed as a cross‐sectional descriptive study. All subjects had a complete physical examination to detect their dermatological disorders and carried out the necessary diagnostic procedures by consultation with the dermatologist.

Results  Eighty percent of all patients were observed to have one or more skin disorders. Xerosis (73.33%) and oral candidiasis (54.17%) were the most common skin disorders, followed by seborrheic dermatitis (46.67%), pruritic papular eruption (36.67%), oral hairy leucoplakia (12.50%), folliculitis (11.67%), herpes zoster (9.17%), and alopecia (6.67%).

Conclusion  Although the pattern of cutaneous lesions was comparable with previous reports, the strikingly lower prevalence of skin tumor and drug eruption was reviewed. Patients with advanced HIV infection were found to have significantly more skin disorders than those with early stage HIV.
Prostatic‐specific antigen and idiopathic hirsutism in females
Authors: Galadari I. , Al‐Mazroei M. , Alkaabi J.
Published: April 2004

Serum prostatic‐specific antigens (PSA) were found recently to be present in several female tissues and fluids. High concentrations of PSA were found in hirsute women in comparison with nonhirsute, as was found in other studies.

In our study we measured the level of PSA in 20 hirsute and 10 control subjects by using an IMx machine from Abbot Laboratories (Diagnostic division, Abbot Park, Illinois 60064, USA). The age, BMI, F‐G score, duration and family history of hirsutism were recorded for both groups. The results were analyzed by using SPSS.

We conclude that there is no significant association between the level of PSA and the presence of hirsutism. Usage of this test as a marker of idiopathic hirsutism needs further evaluation.
A new patient education approach in contact allergic dermatitis: the Contact Allergen Replacement Database (CARD)*
Authors: El‐Azhary Rokea A. , Yiannias James A.
Published: April 2004

Background  When a patient is identified by patch testing as being sensitive to a specific contact allergen, he or she is generally advised to read the product labels and avoid products that contain the specific allergen. Patients are often confronted with difficult chemical names, synonyms, and cross‐reactants for individual allergens. At the same time, dermatologists may spend a considerable amount of time trying to educate their patients about the avoidance of these allergens and explaining which products may contain them.

Methods  We applied a new educational approach to inform patients about products that are free of their allergens.

Results  We present a patient with multiple contact allergens in whom the Contact Allergen Replacement Database was used to educate about specific allergens. This approach has proved to be an invaluable tool for both physicians and their patients in contact allergy counseling.
Ocular albinism with sensorineural deafness
Authors: Tak Woo‐Jung , Kim Myeung‐Nam , Hong Chang‐Kwan , Ro Byung‐In , Song Kye‐Yong , Seo Seong‐Jun
Published: April 2004

Ocular albinism (OA) is an inherited disorder characterized by partial or complete absence of pigment in the eyes. Ocular albinism is inherited in two patterns, X‐linked and autosomal pattern. X‐linked OA includes type I OA (Nettership‐Falls type), type II OA (Forsius‐Eriksson type), and OA with late‐onset sensorineural deafness. The other includes type III OA (autosomal recessive OA) and OA with sensorineural deafness.1 Among the subtypes of ocular albinism, OA with sensorineural deafness has characteristic clinical features: blue eyes, multiple lentigines, and congenital sensorineural deafness.2 This type of ocular albinism is an inherited autosomal dominant trait2 and is considered to be very rare. We report a 28‐year‐old female who was diagnosed with OA with sensorineural deafness.
Subcutaneous granuloma annulare following herpes zoster
Authors: Chang Sung Eun , Bae Gee Young , Moon Kee Chan , Do Sang Hwan , Lim Young Jin
Published: April 2004

A 57‐year‐old Korean man developed a papulovesicular eruption on the right chest with unilateral T2 dermatomal distribution; acute herpes zoster (HZ) was diagnosed. The past medical history revealed diabetes mellitus, but was otherwise noncontributory. His pain gradually subsided with treatment in the Pain Clinic of the Anesthesiology Department. Five months later, however, new skin lesions composed of several papules were detected at the site of the HZ scar. There were several discrete, nontender, firm, erythematous papules of about 0.8 cm in diameter on the right chest (Fig. 1). Histologic examination revealed foci of necrobiotic collagen surrounded by a vague palisade of histiocytes in the deep dermis and subcutis (Fig. 2). Mucin deposits were seen within the center of the palisaded granuloma and there were scattered multinucleated giant cells. Gram, Gomeri‐methenamine silver, and acid‐fast stains were negative. Polarizing microscopy did not reveal any material. Subcutaneous granuloma annulare at the HZ scar was diagnosed, and intralesional injections of triamcinolone caused flattening of the papules after 4 weeks of follow‐up.

Skin examination revealed several discrete, nontender, firm, erythematous papules of about 0.8 cm in diameter on the right upper chest (T2 dermatome)

image

Histologic examination revealed foci of necrobiotic collagen surrounded by a vague palisade of histiocytes in the deep dermis and subcutis. Scattered multinucleated giant cells were seen (hematoxylin and eosin; original magnification, ×100)

image
Infliximab monotherapy in psoriasis: A case of rapid clinical and histological response
Authors: Vincek V. , Jacob S. E. , Nassiri M. , Herbert L. M. , Nadji M. , Kerdel F. A.
Published: April 2004

Background  Psoriasis is a common chronic relapsing, inflammatory, hyperproliferative skin disorder with genetic predisposition. There is currently no experimental model for psoriasis and the pathogenesis is not fully understood. Psoriatic plaques have been shown to contain increased levels of cytokines, including tumor necrosis factor alpha (TNF‐α). Anti‐tumor necrosis factor therapy with infliximab has been shown to be highly effective in recalcitrant psoriasis.

Methods  We evaluated the efficacy and timeline of histological changes in a psoriatic plaque following infliximab infusion. A patient with severe recalcitrant plaque psoriasis was clinically and histologically assessed for improvement.

Results  We found rapid clinical improvement with infliximab accompanied by histopathological changes. The earliest effects were seen on neutrophils and lymphocytes whereas keratinocyte normalization was not evident at the early stages.

Conclusion  Infliximab is not only an effective agent in the treatment of psoriasis but appears to have a very rapid onset of action.
Granulomatous meningitis as a late complication of iodized oil myelography
Authors: Ruberu Nyoka N. , Saito Yuko , Honma Naoko , Sawabe Motoji , Yamanouchi Hiroshi , Murayama Shigeo
Published: April 2004

The present report is an autopsy case of an 83‐year‐old man with severe kyphoscoliosis and granulomatous meningitis as a late complication of iodized oil myelography. He suffered from mild cognitive impairment and died of pneumonia. At autopsy, the brain showed yellow‐brown granular material on its surface, mainly in the Sylvian fissure. Microscopically, granulation tissue was seen around areas of ossification encasing the foreign material. Iodized oil apparently changed into two types of foreign bodies: eosinophilic membranous lipodystrophy‐like features and homogenous yellow crystals of various sizes. The pathology was identical to foreign‐body granulomatous meningitis, caused by iodized oil myelography, and caused cognitive impairment in this patient.
Expression of glial fibrillary acidic protein in developing rat brain after intrauterine infection
Authors: Yu Hui‐Min , Yuan Tian‐Ming , Gu Wei‐Zhong , Li Jian‐Ping
Published: April 2004

In order to investigate the neuropathological effects on the developing rat brain after intrauterine infection, identification of GFAP was observed. Escherichia coli (E. coli) was inoculated into uterine horn of pregnant rats when gestation was 70% complete (15 days) and the control group was inoculated with normal saline. Immunohistochemistry was used for evaluation of GFAP expression in pup brains at postnatal day 1 (P1), P3, P7, P14 and P21, and RT‐PCR was used to analyze GFAP mRNA, interleukin‐1β mRNA (IL‐1β mRNA) and tumor necrosis factor‐α mRNA (TNF‐α mRNA) expression in pup brains at P1, P3 and P7. At P1 and P3. GFAP was expressed very scarcely in periventricular white matter but not in other brain regions between the two groups. Compared with the control group, at P7 GFAP expression of the E. coli‐treated pups was remarkably increased in periventricular white matter and hippocampus. The E. coli‐treated pups at P14 showed a marked increase of GFAP expression in periventricular white matter, corpus callosum and cortex. However, no significant difference in levels of GFAP expression in any brain regions were found at P21 between the two groups. GFAP mRNA expression of the E. coli‐treated pups was higher than the control at P1 and P3, but there was no significant difference between the two groups at P7. IL‐1β mRNA and TNF‐α mRNA expressions of the E. coli‐treated pups were higher than the control at P1 but there was no significant difference between the two groups at P3 and P7. These present results suggest that intrauterine infection could increase GFAP expression in the pup brain and indicate that intrauterine infection might damage the developing white matter and IL‐1β, TNF‐α might be a mechanism mediating between the two events.
Expression of macrophage inflammatory protein‐1α in Schwann cell tumors
Authors: Mori Kanji , Chano Tokuhiro , Yamamoto Kazuo , Matsusue Yoshitaka , Okabe Hidetoshi
Published: April 2004

It is well known that tumors originating from Schwann cells often demonstrate degeneration, such as myxoid areas in Schwannoma (Antoni B) and granular cell tumors. However, the mechanism has never been understood in detail. Recruitment of circulating macrophages plays a role in degeneration, however, the factors leading to that process are not well known. Macrophage inflammatory protein‐1α (MIP‐1α), which belongs to the C‐C family of chemokines, is thought to be involved in the recruitment of inflammatory cells and might play a role in the degenerative change of Schwann cell tumors. To elucidate the role of MIP‐1α in such conditions, we employed immunohistochemistry and in situ hybridization analyses. Strongly positive staining of MIP‐1α was revealed in the myxoid areas of tested tumors and in situ hybridization detected the existence of MIP‐1α mRNA in some of the tumor cells. These results suggest that MIP‐1α produced from tumorigenic cells plays a role in the auto‐degenerative process of Schwann cell tumors. Furthermore, various levels of MIP‐1α expression in these tumors were implicated to be correlated with histological variations.
Intestinal microflora in patients with liver cirrhosis
Authors: Zhao Hai Ying , Wang Hui Ji , Lu Zhi , Xu Shu Zhen
Published: April 2004

OBJECTIVE:  Patients with liver cirrhosis have varying degrees of imbalance of the intestinal flora and probiotics can improve some of the symptoms of gastrointestinal dysfunction in these patients. In the present study, blood ammonia, fecal pH, fecal ammonia, and plasma endotoxin were measured after administration of two kinds of probiotics in order to detect the changes in intestinal flora.

METHODS:  Six bacteria and yeast were cultured and the colony forming units were counted. Fifty cirrhotic patients were randomized to receive probiotic capsules containing Bifidobacterium, Lactobacillus acidophilus and Enterococcus, or probiotic capsules containing Bacillus subtilis and Enterococcus faecium for 14 days. Fecal flora, pH and ammonia, blood ammonia (detected by test paper) and plasma endotoxin (detected by LAL test kits) were measured before and after the treatment.

RESULTS:  Patients with liver cirrhosis had varying degrees of imbalance of the intestinal flora as shown by a decrease in the Bifidobacterium count (10.04 ± 0.78 vs 9.48 ± 1.13, P < 0.05). The severity of the imbalance was matched by that of liver dysfunction, with the most serious imbalance observed in Child‐Pugh C patients. Both types of probiotic increased the Bifidobacterium count (9.46 ± 1.09 vs 10.30 ± 1.11, 9.81 ± 0.62 vs 10.44 ± 1.08, respectively, P < 0.05) and reduced the levels of fecal pH and fecal and blood ammonia (P < 0.05). Probiotics containing B. subtilis and E. faecium reduced the level of endotoxin in cirrhotic patients with endotoxemia (0.0876 ± 0.0117 Eu/mL vs 0.0685 ± 0.0246 Eu/mL, P < 0.05).

CONCLUSIONS:  Patients with liver cirrhosis have an imbalance of intestinal bacteria flora. Probiotics effectively increased the Bifidobacterium count and reduced the level of fecal pH and fecal and blood ammonia.
Therapeutic vaccination against Helicobacter pylori infection with attenuated recombinant Salmonella typhimurium urease B subunit and catalase in mice
Authors: Li Guo Qing , Chen Min Hu , Zhu Sen Lin , Chen Jie , Jiao Zhi Yong , Chen Wei , Hu Pin Jin
Published: April 2004

OBJECTIVE:  To investigate the effects of oral immunization with attenuated recombinant Salmonella typhimurium urease B subunit and catalase vaccines in the treatment of Helicobacter pylori infection in a H. pylori infected mouse model.

METHODS:  Thirty C57BL/6 mice were randomized into three groups and challenged twice with oral administration of H. pylori within 3 days. Four weeks after the second challenge, the mice were immunized by oral administration of attenuated recombinant S. typhimurium urease B subunit (group A), attenuated recombinant S. typhimurium catalase (group B) or saline (group C), and all mice were killed 4 weeks later. The stomachs were collected for a rapid urease test, modified Giemsa staining and quantitative culture to observe the density of H. pylori, hematoxylin–eosin staining was performed to assess the presence of inflammation and lymphocytes from the spleen were used for the lymphoproliferation assay.

RESULTS:  The gastric H. pylori density of groups A, B and C was 1.58 × 105 c.f.u./g, 4.88 × 105 c.f.u./g and 1.92 × 106 c.f.u./g, respectively. The H. pylori density was significantly decreased in the therapeutic groups (P < 0.05). No significant inflammation was found in any group of mice. The lymphoproliferation assays of groups A and B were positive.

CONCLUSION:  Immunization with oral attenuated recombinant S. typhimurium urease B subunit and catalase vaccines is effective in reducing the density of H. pylori colonization.
An Eye Gaze Model for Dyadic Interaction in an Immersive Virtual Environment: Practice and Experience
Authors: Vinayagamoorthy V. , Garau M. , Steed A. , Slater M.
Published: April 2004

This paper describes a behavioural model used to simulate realistic eye‐gaze behaviour and body animations for avatars representing participants in a shared immersive virtual environment (IVE). The model was used in a study designed to explore the impact of avatar realism on the perceived quality of communication within a negotiation scenario. Our eye‐gaze model was based on data and studies carried out on the behaviour of eye‐gaze during face‐to‐face communication. The technical features of the model are reported here. Information about the motivation behind the study, experimental procedures and a full analysis of the results obtained are given in [17].
Approximation of Optimal Voxel Size for Collision Detection in Maintainability Simulations within Massive Virtual Environments
Authors: Borro D. , García‐Alonso A. , Matey L.
Published: April 2004

This paper describes a Collision Method for massive virtual environments composed of millions of triangles. It has been applied in the aeronautics industry for maintainability simulations using virtual aircraft engine mock‐ups. The method performs well and has a good interactive frame rate even when it is used for computing force feedback with haptic devices. Space sorting problems chiefly related to voxel techniques, such as memory requirements and optimal voxel size, have been solved. We use advanced memory structures and hashing techniques. To find the optimal voxel size, several analytical solutions have been proposed and compared. These solutions are based on the performance cost function of the algorithm used. Experiments have been undertaken to verify these analytical solutions.
Cultural Heritage Preservation Using Constructive Shape Modeling
Authors: Vilbrandt C. , Pasko G. , Pasko A. , Fayolle P.‐A. , Vilbrandt T. , Goodwin J. R. , Goodwin J. M. , Kunii T. L.
Published: April 2004

Issues of digital preservation of shapes and internal structures of historical cultural objects are discussed. An overview of existing approaches to digital preservation related to shape modeling is presented and corresponding problems are considered. We propose a new digital preservation paradigm based on both constructive modeling reflecting the logical structure of the objects and open standards and procedures. Constructive Solid Geometry (CSG) and Function Representation (FRep) are examined and practically applied as mathematical representations producing compressed yet precise data structures, thus providing inter‐operability between current and future computer platforms crucial to archiving. Examples of CSG reconstruction of historical temples and FRep modeling of traditional lacquer ware are given. We examine the application of fitting of a parameterized FRep model to a cloud of data points as a step towards automation of the modeling process. Virtual venues for public access to cultural heritage objects including real time interactive simulation of cultural heritage sites over the Web are discussed and illustrated.
Implicit Fitting Using Radial Basis Functions with Ellipsoid Constraint
Authors: Li Q. , Wills D. , Phillips R. , Viant W. J. , Griffiths J. G. , Ward J.
Published: April 2004

Implicit planar curve and surface fitting to a set of scattered points plays an important role in solving a wide variety of problems occurring in computer graphics modelling, computer graphics animation, and computer assisted surgery. The fitted implicit surfaces can be either algebraic or non‐algebraic. The main problem with most algebraic surface fitting algorithms is that the surface fitted to a given data set is often unbounded, multiple sheeted, and disconnected when a high degree polynomial is used, whereas a low degree polynomial is too simple to represent general shapes. Recently, there has been increasing interest in non‐algebraic implicit surface fitting. In these techniques, one popular way of representing an implicit surface has been the use of radial basis functions. This type of implicit surface can represent various shapes to a high level of accuracy. In this paper, we present an implicit surface fitting algorithm using radial basis functions with an ellipsoid constraint. This method does not need to build interior and exterior layers for the given data set or to use information on surface normal but still can fit the data accurately. Furthermore, the fitted shape can still capture the main features of the object when the data sets are extremely sparse. The algorithm involves solving a simple general eigen‐system and a computation of the inverse or psedo‐inverse of a matrix, which is straightforward to implement.
Hardware Lighting and Shading: a Survey
Authors: Kautz Jan
Published: April 2004

Traditionally, hardware rasterizers only support the Phong lighting model in combination with Gouraud shading using point light sources. However, the Phong lighting model is strictly empirical and physically implausible. Gouraud shading also tends to undersample the highlight unless a highly tesselated surface is used. Hence, higher‐quality hardware accelerated lighting and shading has gained much interest in the recent five years. The research on hardware lighting and shading is two‐fold. On the one hand, better lighting models for local illumination (assuming point light sources but evaluated per pixel) were demonstrated to be amenable to hardware implementation. On the other hand, recent research has demonstrated that even area lights, represented as environment maps, can be combined with complex lighting models. In both areas, many articles have been published, making it hard to decide which algorithm is well‐suited for which application. This state‐of‐the‐art report will review all relevent articles in both areas, and list advantages and disadvantages of each algorithm.
Accounting Reform in Greek Universities: A Slow Moving Process
Authors: Venieris George , Cohen Sandra
Published: April 2004

Reforms in the public sector have traditionally been faced by resistance and problems. Pettigrew justifies this attitude on theoretical grounds as the exercise of power from individuals and groups threatened by a change in strategy. The paper analyses this case by referring to the attempts of introducing accrual and management accounting practices in Greek Public Universities. Via a detailed examination of the context within which this reform took place and the phases it went through, we endeavour to explain, by using Pettigrew's theory regarding strategy and decision‐making, why it has not yet seriously progressed even though it was initiated in 1996.
Benchmarking University Activities: An Italian Case Study
Authors: Arnaboldi Michela , Azzone Giovanni
Published: April 2004

This paper is a study of the use of benchmarking as a management accounting device aimed at facilitating and influencing decisions within an Italian university, which is undergoing significant change. The transformation of this organisation originates from a new legislative rationale of the Italian government where all universities have gained an increased autonomy in managing and allocating resources, and the university studied here has installed a new management team. Action research was used to benchmark resources across university departments, identifying critical areas, and informing budgeting and planning, drawing on activity based approaches. The paper discusses the behavioural resistance faced in introducing cost measurement systems in this organisation, which have been used to receiving a continuous flow of resources from central government.
Differentiation Pattern of Vero Cells Cultured on Poly(L‐Lactic Acid)/Poly(Hydroxybutyrate‐co‐Hydroxyvalerate) Blends
Authors: Santos Arnaldo R. , Ferreira Betina M.P. , Duek Eliana A.R. , Dolder Heidi , Wada Ronaldo S. , Wada Maria Lucia F.
Published: April 2004

Abstract:  This study evaluates the effect of poly(L‐lactic acid) (PLLA) and poly(hydroxybutyrate‐cohydroxyvalerate) (PHBV) bioabsorbable polymers and their blends on the induction of alteration of cell growth pattern in vitro. Vero cells were cultured on PLLA, PHBV, and different blends (100/0, 60/40, 50/50, 40/60, and 0/100). The cell adhesion assay showed that the best results were obtained with the (60/40, 50/50) blends. Scanning electron microscopy showed that the cells on (100/0) and (60/40) samples grew with a round morphology preferentially in the porous areas. The (50/50) blends had cells in the porous and smooth areas in a similar way. The (40/60) blends showed spreading cells on the smooth areas. The (0/100) sample, which had no pores, had spreading cells interconnected by filaments. Histological sections showed a confluent cell monolayer and the immunocytochemistry showed that the cells produced collagen IV and fibronectin on all substrates. Thus, we conclude that PLLA/PHBV blends were efficient in maintaining cell growth and producing an extracellular  matrix on them.
Diabetes‐induced Alterations in Latissimus Dorsi Muscle Properties Impair Effectiveness of Dynamic Cardiomyoplasty in Rats
Authors: De Angelis Kátia , Senna Sueli , Irigoyen Maria Cláudia , Cestari Idágene A.
Published: April 2004

Abstract:  Short‐term diabetes was induced in male Wistar rats with streptozotocin injection. The effects of diabetes on latissimus dorsi (LD) muscle contractile and biochemical properties and acute cardiomyoplasty (CDM) were assessed and compared with data from 16 control rats. Isometric force, contractile properties, and fatigue were measured in electrically stimulated muscles (0.3 ms, 1–256 Hz), and Na+K+ and Ca2+ATPase activities were quantified in muscle membrane preparations. Systolic arterial pressure and aortic blood flow were recorded at rest and during LD muscle stimulation. Compared with control muscle, diabetic muscle showed smaller maximum specific tetanic tension and lower rates of rise and fall in force. Diabetic LD muscle also showed lower muscle enzyme activities. Twitch tension and fatigue did not differ between groups. Smaller increases in aortic flow and systolic pressure after CDM were found in diabetic rats compared to controls. The marked decrease in CDM effectiveness in diabetic rats likely reflected the alterations in muscle properties associated with diabetes.
Cardiac Output Determination During Experimental Hemorrhage and Resuscitation Using a Transesophageal Doppler Monitor
Authors: De Figueiredo Luiz Francisco Poli , Cruz Ruy Jorge , Silva Eliezer , Rocha e Silva Maurício
Published: April 2004

Abstract:  Transesophageal Doppler (TED) monitoring has been considered a noninvasive and accurate alternative to pulmonary artery catheterization for volume replacement and cardiac output measurement in patients undergoing major surgery. This study tested the hypothesis that TED can accurately predict cardiac output during hemorrhage, shock, and resuscitation, by comparing it to total pulmonary artery blood flow (PABF) and to standard intermittent bolus cardiac output (ICO). In eight anesthetized dogs (18 ± 1.0 kg), PABF was measured with an ultrasonic flowprobe while ICO and mixed venous O2 saturation (SvO2) were measured through a Swan‐Ganz catheter. A TED probe (CardioQ, Deltex Medical Inc., Irving, TX, U.S.A.), designed for adult use (minimum 30 kg, 16 years), was placed in midesophageous to evaluate stroke volume. A graded hemorrhage (20 mL/min) was produced (H5–H35) to a mean arterial pressure (MAP) of 40 mm Hg and maintained by additional blood removal for 30 min (S1–S30). Total shed blood volume was retransfused (541 ± 54.2 mL) over 30 min (T5–T30), after which a massive hemorrhage, 100 mL/min rate, was produced over 10 min (MH5–MH10). In general, TED overestimated PABF (r2 = 0.3472), but changes in TED paralleled PABF throughout the experimental protocol, particularly during massive hemorrhage (r2 = 0.9001). We concluded that TED accurately reflected the direction and magnitude of the changes of cardiac output over time during abrupt hemodynamic changes. Probes designed for lower weights and smaller aortas may improve its accuracy in medium size animal models under less dramatic alterations induced by hemorrhage, shock, and resuscitation.
Comparison of pH‐Stat Versus Alpha‐Stat During Hypothermic Cardiopulmonary Bypass in the Prevention and Control of Acidosis in Cardiac Surgery
Authors: Piccioni Marilde A. , Leirner Adolfo A. , Auler José O.
Published: April 2004

Abstract:  Objectives: To compare the effects of blood‐gas management using either alpha‐stat (temperature‐uncorrected blood‐gas management) or pH‐stat (temperature‐corrected blood‐gas management) strategies, 30 patients undergoing coronary artery bypass surgery allocated randomly to either one of the approaches were studied. Acid–base balance, tissue oxygenation, and biochemical parameters were measured at distinct times: before bypass, after 15 min of hypothermia at 32°C, after 45 min of hypothermia at 32°C, after 15 min of rewarming at 37°C, and 45 min after the end of bypass in normothermic conditions. Results: The groups were similar with regard to physical characteristics, physiological parameters, and bypass time. In the pH‐stat group, CO2 administered with the aim of correcting pH for the patients hypothermic temperature caused a significant increase in temperature‐uncorrected PaCO2 and a decrease in arterial temperature‐uncorrected pH at 45 min. During the rewarming period and following bypass, the pH was lower and PaCO2 higher in the pH‐stat group (P < 0.001). Conclusion: It was found that during the rewarming period and following bypass, the resulting acidosis caused by the procedure was less in the alpha‐stat group. It was found that there were no difference between the two groups, with regard to tissue perfusion, as is seen by the tissue oxygenation parameters and  lactic  acid  concentration.
Breast Reconstruction with Expanders and Implants: A Numerical Analysis
Authors: Pamplona Djenane Cordeiro , De Abreu Alvim Cristina
Published: April 2004

Abstract:  In the last few decades, breast reconstruction has evolved significantly due to improvement in surgical techniques and development of new materials. Although most authors consider that breast reconstruction using autologous tissue offers the best aesthetic results, excellent outcomes have been obtained employing silicone implants. However there is a lack of good understanding of the implications of using each type of adjustable implant on tissue dynamics and the influence on final breast shape. The aim of this research is to analyze the stresses and strains that occur in skin immediately after breast reconstruction. This simulation is performed using the finite element package  ABAQUS/Explicit.
Experimental Comparison of Electrodes for Intracavitary Cardioversion of Atrial Fibrillation: Effectiveness and Safety of a New Electrode
Authors: Milioli Duane J. , Leirner Adolfo A.
Published: April 2004

Abstract:  The right atrium (RA)‐external thorax (ET) arrangement has several advantages when used for intracavitary cardioversion of atrial fibrillation (AF): it utilizes a single catheter, the procedure does not need radioscopic follow‐up, little endovascular contact results, and there is flexibility in the positioning of the ET electrode. However it is not commonly used and only scantly studied. Objectives: To evaluate experimentally in animals the efficacy and safety of a new loop electrode placed in the RA in the RA‐ET arrangement and to compare it with the RA‐pulmonary artery (PA) configuration. Method: Ten mongrel dogs with acute induced AF are to be cardioverted with the two arrangements, using increasing levels of energy and its efficacy compared. If lesions show up in the anatomic pathology, a complementary study with three animals will be carried out to assess its origin. Results: The average energy needed for cardioversion was similar in the two arrangements (P = 0.86). Myocardial lesions found were not attributable to the new electrode but supposedly to the AF induction catheter. Conclusion: The new electrode model is effective and safe, besides being easy to use and  of  low  cost.
In vitro organogenesis of gut‐like structures from mouse embryonic stem cells
Authors: Kuwahara M. , Ogaeri T. , Matsuura R. , Kogo H. , Fujimoto T. , Torihashi S.
Published: April 2004

Embryonic stem (ES) cells have pluripotency and give rise to many cell types and tissues, including representatives of all three germ layers in the embryo. We have reported previously that mouse ES cells formed contracting gut‐like organs from embryoid bodies (EBs). These gut‐like structures contracted spontaneously, and had large lumens surrounded by three layers, i.e. epithelium, lamina propria and muscularis. Ganglia were scattered along the periphery, and interstitial cells of Cajal (ICC) were distributed among the smooth muscle cells. In the present study, to determine whether they can be a model of gut organogenesis, we investigated the formation process of the gut‐like structures in comparison with embryonic gut development. As a result, we found that the fundamental process of formation in vitro was similar to embryonic gut development in vivo. The result indicates that the gut‐like structure is a useful tool not only for developmental study to determine the factors that induce gut organogenesis, but also for studies of enteric neurone and ICC development.
Intrinsic primary afferent neurones of the digestive tract
Authors: Clerc N. , Furness J. B.
Published: April 2004

Intrinsic primary afferent neurones of the intestine are specialized neurones that encode information about the state of the intestine by transducing mechanical and chemical stimuli that reflect tension in the gut wall and the chemical nature of its contents. They connect with interneurones and motor neurones in the gut to form the circuits of intrinsic muscle motor, secretomotor and vasomotor reflexes. A large range of ionic currents occur in these neurones. The neurones have voltage‐activated inward sodium currents (both tetrodotoxin‐sensitive and tetrodotoxin‐insensitive) and inward calcium currents. Calcium entering during the action potential activates a slow afterhyperpolarizing potassium current that has a profound influence on subsequent action potential firing. They also exhibit a prominent hyperpolarization‐activated nonspecific cation current. The excitability of these neurones and sensory transduction are altered when the gut is inflamed. Changed excitability can persist after the inflammatory state has subsided. Intrinsic primary afferent neurones are thus important, both to the normal physiology and to pathophysiology of the small and large intestines.
Neuroanatomy of extrinsic afferents supplying the gastrointestinal tract
Authors: Berthoud H. R. , Blackshaw L. A. , Brookes S. J. H. , Grundy D.
Published: April 2004

Here we discuss the neuroanatomy of extrinsic gastrointestinal (GI) afferent neurones, the relationship between structure and function and the role of afferents in disease. Three pathways connect the gut to the central nervous system: vagal afferents signal mainly from upper GI regions, pelvic afferents mainly from the colorectal region and splanchnic afferents from throughout. Vagal afferents mediate reflex regulation of gut function and behaviour, operating mainly at physiological levels. There are two major functional classes − tension receptors, responding to muscular contraction and distension, and mucosal receptors. The function of vagal endings correlates well with their anatomy: tracing studies show intramuscular arrays (IMAs) and intraganglionic laminar endings (IGLEs); IGLEs are now known to respond to tension. Functional mucosal receptors correlate with endings traced to the lamina propria. Pelvic afferents serve similar functions to vagal afferents, and additionally mediate both innocuous and noxious sensations. Splanchnic afferents comprise mucosal and stretch‐sensitive afferents with low thresholds in addition to high‐threshold serosal/mesenteric afferents suggesting diverse roles. IGLEs, probably of pelvic origin, have been identified recently in the rectum and respond similarly to gastric vagal IGLEs. Gastrointestinal afferents may be sensitized or inhibited by chemical mediators released from several cell types. Whether functional changes have anatomical correlates is not known, but it is likely that they underlie diseases involving visceral hypersensitivity.
Enteric motor and interneuronal circuits controlling motility
Authors: Bornstein J. C. , Costa M. , Grider J. R.
Published: April 2004

The enteric nervous system regulates intestinal motility. It contains intrinsic sensory neurones, several types of interneurones and excitatory and inhibitory motor neurones. This review summarizes our knowledge of motor neurones and interneurones in simple motility reflex pathways (ascending and descending excitation, descending inhibition) and it focuses on guinea‐pig ileum. Excitatory circular muscle motor neurones contain choline acetyltransferase (ChAT) and tachykinins and project orally 0.5–10 mm. They transmit via muscarinic acetylcholine receptors and tachykinins acting at NK1 and NK2 receptors. Inhibitory circular muscle motor neurones contain nitric oxide synthase (NOS), vasoactive intestinal peptide (VIP) and pituitary adenylyl cyclase activating peptide (PACAP), project anally up to 25 mm and transmit via ATP, nitric oxide and/or VIP. Ascending interneurones project up to 10 mm orally and contain ChAT and tachykinins. They transmit to each other via ACh at nicotinic receptors (nAChR), but to excitatory motor neurones via both nAChR and NK3 receptors. There are at least three types of descending interneurones and one transmits to inhibitory motor neurones via ATP acting at P2X receptors. NOS‐containing descending interneurones receive input via P2Y receptors from other interneurones. Transmission to and from the other descending interneurones (ChAT/5‐HT, ChAT/somatostatin) is yet to be characterized.
Submucosal secretomotor and vasodilator reflexes
Authors: Vanner S. , Macnaughton W. K.
Published: April 2004

The presence of neuronal reflexes within the intestine that modulate mucosal ion secretion and blood flow have been recognized for many years, but the organization of these reflexes was unclear. This review highlights important findings from recent in vitro guinea‐pig studies which have shown that both intrinsic primary afferent neurones (IPANs) and extrinsic primary afferent neurones (EPANs) can respond to chemical and/or mechanical stimuli to activate pathways, the afferent and efferent elements of which are confined to the walls of the intestine. Enteric neuronal pathways involve both myenteric and submucosal plexus neurones whereas capsaicin‐sensitive afferent nerves evoke secretion by stimulating submucosal secretomotor neurones and vasodilation by direct actions on the submucosal arterioles. In this review, the cellular mechanisms involved in these pathways are described and the implications of these findings are discussed.
Lessons from the porcine enteric nervous system
Authors: Brown D. R. , Timmermans J.‐P.
Published: April 2004

The porcine intestinal tract possesses functional and pathological similarities to the human digestive tract and the organization of the porcine enteric nervous system, like that of the human, appears to be more complex than that of commonly investigated guinea‐pig intestine. Intrinsic primary afferent neurones appear to differ in the intestines of large and small animals in terms of their chemical coding, distribution over enteric neural networks, electrophysiological behaviour and synaptic properties. Opioid receptors on afferent and motor neurones in the porcine small intestine are predominately of the delta type, whereas those in guinea‐pig ileum are mu. Moreover, delta‐opioid receptors associated with the myenteric and submucosal plexuses of porcine ileum that, respectively, modulate neurogenic smooth muscle contractions and mucosal ion transport appear to differ in their pharmacological characteristics. These profound interspecies and interregional differences underscore the complexity of the enteric nervous system, and the development of new drugs designed to treat human neurogastrointestinal disorders should be based on the results of investigations in homologous animal models, such as the pig.
Role of interstitial cells of Cajal in neural control of gastrointestinal smooth muscles
Authors: Ward S. M. , Sanders K. M. , Hirst* G. D. S.
Published: April 2004

Specialized cells known as interstitial cells of Cajal (ICC) are distributed in specific locations within the tunica muscularis of the gastrointestinal tract and serve as electrical pacemakers, active propagation pathways for slow waves, and mediators of enteric motor neurotransmission. Recent morphological studies have provided evidence that motor neurotransmission in the gut does not occur through loosely defined synaptic structures between nerves and smooth muscle, but rather via synaptic‐like contacts that exist between varicose nerve terminals and intramuscular ICC (ICC‐IM). ICC‐IM are coupled to smooth muscle cells via gap junctions and electrical responses elicited in ICC are conducted to muscle cells. Electrophysiological studies of the stomach of wild‐type and mutant animals that lack ICC‐IM have provided functional evidence for the importance of ICC in cholinergic and nitrergic motor neurotransmission. The synaptic‐like contacts between nerve terminals and ICC‐IM facilitate rapid diffusion of transmitters to specific receptors on ICC. ICC‐IM also play a role in generating unitary potentials in the stomach that contribute to the excitability of the gastric fundus and antrum.
Communication between interstitial cells of Cajal and gastrointestinal muscle
Authors: Daniel E. E.
Published: April 2004

Interstitial cells of Cajal (ICC) pace gastrointestinal muscle by initiating slow waves in both muscle layers and appear to be preferred sites for reception of neurotransmitters. ICC of the myenteric plexus (ICC‐MP) pace stomach and small intestine, while intramuscular ICC (ICC‐IM) receive nerve messages. Recently, ICC‐IM have been found to provide regenerative responses to and amplification of pacing messages from ICC‐MP, at least in some systems. This review will examine the assumption that gap junctions provide low‐resistance contacts for pacing. Structural and functional evidence will be evaluated. Structural, theoretical and experimental difficulties with the gap junctions hypothesis for pacing will be considered. So far little direct evidence about the role of gap junctions in neurotransmission exists, although a structural basis exists. Alternate possibilities for transmission of ICC pacing and neural messages will be examined and suggestions for future research made.