bluuebunny/crossref_metadata_2025 huggingface dataset:
Fcγ receptors in the initiation and progression of systemic lupus erythematosus
Authors: Reefman Esther , Dijstelbloem Hilde M , Limburg Pieter C , Kallenberg Cees GM , Bijl Marc
Published: September 2003

Systemic lupus erythematosus, a systemic autoimmune disorder, is characterized by the production of autoantibodies to nuclear constituents and inflammatory lesions in multiple organ systems. Although the pathogenesis of the disease is largely unknown, recent studies have suggested that disturbances in apoptosis and/or clearance of apoptotic cells may play an important role in the induction and perpetuation of autoantibody production. When autoantibodies subsequently complex to autoantigens present on apoptotic cells, ligation of Fcγ receptor will result in inflammation and disease development. Indeed, mice deficient in activating Fcγ receptors were protected against inflammation in models of immune complex‐mediated autoimmune disease, whereas deletion of the inhibitory Fcγ receptors increased autoantibody production and susceptibility to immune complex‐induced inflammation. Additionally, functional polymorphisms in Fcγ receptors were shown to be associated with development of human systemic lupus erythematosus. This review focuses on the role of Fcγ receptors in the initiation of autoantibody production, inflammatory handling of immune complexes, and disease development in systemic lupus erythematosus.
Identification of mature plasma cells in early rat yolk sac. A possible origin from the endodermal cell layer: Immunohistochemistry and immunoelectron microscopic study
Authors: El‐Nefiawy Nagwa , Abdel‐Hakim Khaled , Kanayama Naohiro , Suganuma Nobuhiko , Terao Toshihiko
Published: September 2003

Plasma cells play a pivotal role in the immune system and are responsible for the synthesis and release of immunoglobulins. Numerous in vitro culture experiments on the yolk sac demonstrated the generation of mature cells of the myeloid and lymphoid lineages under appropriate culture conditions. However, there are no reports describing the development of mature lymphoid cells in the yolk sac so far. For this reason, we undertook this study to investigate the development of antibody‐containing plasma cells during early yolk sac haematopoiesis. Immunohistochemistry and immunoelectron microscopy were employed in the study. Results of this work demonstrated very weak immune staining for the intracytoplasmic IgA, IgG, and IgM at days 10 and 11 of embryonic life, while dark staining was obtained at 12 days. Positive staining was localized to the endodermal cell layer. Electron microscopic examinations revealed the existence of cells with the typical characteristics of plasma cells inside the endodermal cell layer, which may suggest their endodermal origin. To further verify the nature of these cells, intracytoplasmic immunoglobulins were demonstrated by immunoelectron microscopy. The present study demonstrated emergence of mature functioning plasma cells in early rat yolk sac. In a previous work we hypothesized the possibility of endodermal origin of yolk sac macrophages. This study adds additional evidence to support that hypothesis. The possible role of plasma cells in the yolk sac is discussed.
Bacillus circulans endophthalmitis
Authors: Tandon Anita , Tay‐Kearney Mei‐Ling , Metcalf Cecily , McAllister Ian
Published: September 2003

An 80‐year‐old woman presented with right endophthalmitis, characterized by chalky white deposits covering her posterior capsule. This occurred 17 months after uncomplicated right cataract surgery. A three‐port pars plana vitrectomy and partial posterior capsulectomy isolated Bacillus circulans, and the patient made a rapid and full recovery on topical cephalothin and prednisolone acetate 1%. The case demonstrates that, unlike endophthalmitis due to other Bacillus spp., B. circulans endophthalmitis does not necessarily follow a fulminant course. It is the first report describing a subacute presentation, and response to posterior capsulectomy and simple antibiotic therapy. It is also the first description of B. circulans causing white plaques in the posterior capsule, a finding characteristic of chronic endophthalmitis and previously considered pathognomonic of Proprionibacterium acnes endophthalmitis.
Is the corneal degradation in keratoconus caused by matrix‐metalloproteinases?
Authors: Collier Simon A
Published: September 2003

The thinning of the cornea that occurs in keratoconus has been well described; however, the mechanism of tissue degradation remains unknown. Elevated proteinase activity is one possibility and approximately 20 publications over the last 20 years have addressed this hypothesis. Early studies reported increased collagenase and gelatinase activities in the medium of keratoconus corneal cultures. After the characterization of the matrix metalloproteinase (MMP) enzymes, studies focused on the expression of specific MMPs, in particular the gelatinases, MMP‐2 and MMP‐9. Matrix metalloproteinase‐2 was found to be the major MMP of the cornea and was constitutively produced in normal tissue, whereas MMP‐9 expression was induced by various stimuli, including phorbol esters and even tissue culturing. These studies suggested that there were no differences in the amounts or states of activation of MMP between normal and keratoconus corneas, although the amounts of some proteinase inhibitors, including tissue inhibitors of metalloproteinases, α‐1‐proteinase inhibitor and α‐2‐macroglobulin, were decreased in keratoconus. Most recently, the lysosomal proteinases, cathepsin B and cathepsin G were reported to be elevated in keratoconus corneas, and it is possible that it was cathepsin activity, not MMP activity, that was measured in some early studies. Nevertheless, there are now about 20 human MMPs identified and it is possible that some of these, other than the well known collagenase (MMP‐1) and gelatinases (MMP‐2 and MMP‐9), could be implicated in the pathology of keratoconus. Studies have begun to address more recently described MMPs and it has been reported that the membrane‐bound MT1‐MMP (MMP‐14), which activates latent MMP‐2, was found to have increased expression in keratoconus corneas, whereas the stromelysins, MMP‐3 and MMP‐10, were not.
Uveitis: what do we know and how does it help?
Authors: Lightman Susan
Published: September 2003

Uveitis essentially means intraocular inflammation and encompasses a wide variety of different disorders. This includes both mild and severe types of inflammation affecting different parts of the eye. Histologically, all uveitis is characterized by an influx of lymphocytes into the affected tissue. In all types these lymphocytes are predominantly of the CD4 type, whether the disorder is mild or blinding, giving no clue as to why. New studies comparing cells in ocular fluids taken from inflamed eyes with different types of inflammation have, for the first time, shown a difference in the cytokine profile, so that in visually benign disease interleukin 10 levels are higher than in those which are blinding. The potential for this in terms of therapy is discussed.
Endophthalmitis in the western Sydney region: a case‐control study
Authors: Lertsumitkul Somsak , Myers Phillip C , O'Rourke Michael T , Chandra Jay
Published: September 2003

Background: A retrospective case‐control study was conducted to investigate risk factors for endophthalmitis following routine intraocular surgery.

Methods: A review was performed of consecutive cases of endophthalmitis from three teaching hospitals in the western Sydney region and matched controls from the same institutions between 1996 and 1998.

Results: There were 31 cases and 66 controls. Eighty procedures were phacoemulsification, 15 conventional extracapsular cataract extraction, and two were penetrating keratoplasties. Of the 80 patients who had phacoemulsification surgery, 50 had a clear corneal incision, and 26 had a scleral incision (four were unknown). Logistic regression showed an increased risk of endophthalmitis with surgical complications (P = 0.002) and clear cornea temporal incisions (P = 0.007). Risk of endophthalmitis was reduced with use of subconjunctival injections (P = 0.008). The yield for the Gram stain was 47% and for culture was 67%. Anterior chamber tap in addition to vitreous biopsy alone did not increase the yield for microorganism (P = 0.78). Mean visual acuity on presentation was hand movement with 13 patients (50%) showing visual improvement following intravitreal injections of antibiotics (P = 0.003). Visual prognosis did not correlate with presenting visual acuity but appeared to be better in those who grew Staphylococcus epidermidis or were culture negative.

Conclusions: Although this study is unable to draw definite conclusions regarding risk of endophthalmitis in clear corneal temporal cataract surgery, sufficient data suggest the importance of incision type and location. Surgical complication is an important risk factor for endophthalmitis. Use of subconjunctival antibiotic injections at the conclusion of the procedure is recommended.
The waiting game: natural history of a cataract waiting list in New Zealand
Authors: Riley Andrew F , Grupcheva Christina N , Malik Tahira Y , Craig Jennifer P , McGhee Charles NJ
Published: September 2003

Aims: To identify the demographic and visual function of patients on the reserve waiting list for cataract surgery at a large public hospital within New Zealand and to determine the ultimate outcome of those on a priority‐based, rationed, health‐care waiting list.

Methods: Patients from a defined geographical population, placed on a reserve waiting list for possible cataract surgery, during the period January 1997 to March 2000, were invited to attend for further clinical assessment and asked to complete a visual assessment questionnaire.

Results: Of 193 patients in the pilot study group who had been on the reserve waiting list for a mean of 18.2 ± 11.6 months (range 0.1–62.7 months), only 94 (49%) were deemed suitable for, and subsequently underwent, surgery in the public sector. Forty‐nine (25%) had undergone surgery earlier, the majority of these (84%) in the private sector. A further 23 (12%) patients were deceased, four (2%) declined surgery and in six (3%) cataract surgery was no longer indicated. The remaining 11 (6%) patients could not be traced. Patients still awaiting surgery had a mean age of 77.2 years (range 48–95 years). Fifty‐four were women. Vision had deteriorated by a mean of 0.05 LogMAR units, from Snellen equivalent 6/30 at listing to 6/36, over this time.

Conclusions: Current methods of prioritization for cataract surgery are imperfect, as are the resources for performing adequate levels of cataract surgery. Analysis of a residual waiting list for cataract surgery highlights that the majority (51%) do not ultimately progress to cataract surgery in the public sector for a variety of reasons. During a mean waiting time of 1.5 years vision further deteriorates in this predominantly older population.
Diabetic retinopathy: effects of national guidelines on the referral, examination and treatment practices of ophthalmologists and optometrists
Authors: McCarty Catherine A , Taylor Kathryn I , McKay Robert , Keeffe Jill E
Published: September 2003

Objective: To investigate the changes in referral, examination and treatment practices for diabetic retinopathy by ophthalmologists and optometrists following the release of national guidelines.

Methods: A two‐page self‐administered questionnaire was mailed to all Australian ophthalmologists and a random sample of 500 Australian optometrists prior to and 1 year after release of the National Health and Medical Research Council of Australia (NHMRC) clinical practice guidelines for the management of diabetic retinopathy. The questionnaires elicited information about current practice related to the management of patients with diabetic retinopathy.

Results: Of the 464 contactable ophthalmologists who responded to the baseline survey, 374 (80.6% response) completed the follow‐up survey. The response rate for the contactable optometrists was 80.1% (310 of 384). There were almost no significant changes in management practices from baseline to follow up. For example, the percentage of ophthalmologists who reported that they were often or almost always confident in detecting moderate retinal thickening near the macula remained nearly identical from baseline to follow up (80.2% vs 79.1%). The rate was also similar from baseline to follow up for optometrists (31.1% vs 28.8%). The one area in which ophthalmologists reported significant changes in management towards agreement with the NHMRC guidelines was use of angiography; they were less likely to manage their patients this way (20.4% vs 14.2% with laser and 48.9% vs 38.4% without laser for increasing level of severity in clinical signs; both P < 0.05).

Conclusions: The NHMRC guidelines for diabetic retinopathy have been successfully distributed to ophthalmologists and optometrists in Australia. However, the mere provision of the guidelines has had little impact on management practices. It will be important to determine if ongoing dissemination and implementation strategies not only increase awareness of health‐care practitioners to the guidelines, but also change behaviours.
Ophthalmologists in teaching hospitals: do we make a difference to patient outcome?
Authors: Bala Chandra , Poon Alexander C , Joblin Paul , McCluskey Peter J
Published: September 2003

Purpose: To determine the type and frequency of consultations with the eye department of a major tertiary care teaching hospital.

Methods: A retrospective review was undertaken of the medical records of inpatient consultations within the Ophthalmology Department of Royal Prince Alfred Hospital over the period from 1 July 1995 to 30 June 1997. The consults were divided into six types of consultation. A determination was made of the outcome and effect on patient management of each consultation.

Results: There were 506 consultations over the 2‐year period. For 389 patients a full ophthalmic assessment was requested and 175 of them (45%) had an ophthalmological diagnosis made or had change in management as a result of the consultation.

Conclusion: Ophthalmological consultation is a valuable inpatient consultation service that makes a significant difference in the management of patients from other medical and surgical units within the hospital.
Transcaruncular medial orbitotomy for stabilization of the posterior limb of the medial canthal tendon
Authors: Francis Ian C , Wilcsek Geoffrey A , Sharma Shanel , Coroneo Minas T
Published: September 2003

Purpose: A method to stabilize the posterior limb of the medial canthal tendon (MCT), using a transcaruncular medial orbitotomy (TMO) approach, is described in a stepwise fashion. The technique described is a modified version of procedures published by Ritleng, Crawford and Collin, and Fante and Elner.

Methods: A prospective clinical evaluation of MCT stabilization via the TMO approach was undertaken in 11 consecutive patients who presented with MCT laxity as one of the features of their ectropion. These cases are initially described in detail in two representative case reports, and summarized in 11 cases. The stepwise surgical approach is outlined.

Results: All patients had improved symptomatology in terms of epiphora and comfort. Furthermore, in all cases the lid position was improved or normalized. In four of the 11 cases (36%) the lower punctum did not ultimately reside in the lacrimal lake, but the punctal position was nevertheless improved and the MCT was stabilized.

Conclusion: The TMO procedure provides both excellent MCT stabilization and adequate placement of the lower lacrimal punctum onto the globe. It does not require canalicular resection, and avoids continued anterior displacement of the medial lower lid which may occur when only the anterior limb of the MCT is addressed surgically.
Evaluation of the quality of generic polymethylmethacrylate intraocular lenses marketed in India
Authors: Combe Richard , Watkins Rod , Brian Garry
Published: September 2003

Purpose: To determine the quality of single‐piece, all‐ polymethylmethacrylate (PMMA) intraocular lenses (IOLs) from eight generic manufacturers marketing their product in India. This assessment of quality was made with respect to compliance with international standards for the manufacture of IOLs, specifically those parameters most likely to affect patient postoperative visual acuity and the long‐term biocompatibility of the implanted lens.

Methods: Ten IOLs from each of eight manufacturers were purchased randomly from commercial retail outlets in India. Each IOL, in a masked fashion, had its physical dimensions, optical performance and cosmetic appearance assessed, using the methods prescribed in ISO 11979‐2 and 11979‐3. Validation of manufacturing process controls were determined by statistical process control techniques. Four IOLs from each manufacturer were also tested for the presence of unpolymerized PMMA using gas chromatography.

Results: Only lenses from two IOL manufacturers complied with the optical and mechanical standards. All other manufacturers’ lenses failed one or more of these tests. Intra‐ocular lenses from only two producers met with surface quality and bulk homogeneity standards. All others exhibited defects such as surface contamination and scratches, poor polishing, and chipped or rough positioning holes. Lenses from two producers exhibited high levels of methylmethacrylate monomer (MMA).

Conclusions: Non‐clinical grade PMMA starting material may have been used in the manufacture of IOLs by some producers. Critical manufacturing defects occurred in the IOLs from five of the eight producers tested. Only one manufacturer's IOLs met all specifications, and on statistical analysis demonstrated good manufacturing process control with respect to the properties tested. With the widespread acceptance of IOL implantation in developing countries, such as India, it is essential that in the rush to make this the norm, the quality of implants used not be overlooked.
Childhood cataracts
Authors: Chia Wei‐Lin A , Martin Frank
Published: September 2003

Objective: The aim of this study was to determine the surgical outcome of childhood cataracts.

Method: Between 1990 and 1997, 137 patients less than 10 years of age (181 eyes) underwent cataract surgery at the Royal Alexandra Hospital for Children/New Children's Hospital. Data were collected retrospectively from medical records and supplemented with data from referring ophthalmologists.

Results: In the majority of patients (53.0%), the cause of cataract was unknown. Sixty‐two patients (45.3%) had bilateral and 75 patients (54.7%) had unilateral cataracts. In 84 patients (107 eyes; 59.1%), the onset of visually significant cataract was estimated to be before the age of 2 years. Reliable postoperative visual acuity (VA) was obtained in 150 eyes from 116 patients. The mean LogMAR VA was 0.71 ± 0.55 in bilateral cataracts and 1.17 ± 0.68 in unilateral cataracts. Visual acuity was poor (LogMAR VA > 1.0) in 71.8% of unilateral cataracts (compared to 27.9% in bilateral cataracts, P < 0.0001), and in 64.9% when onset was less than 2 years (compared to 22.4% in later onset cataract, P < 0.0001). Posterior capsular opacity requiring laser or surgical removal was noted in 40 patients (44 eyes; 24.4%). Other complications included raised intraocular pressure in six patients (seven eyes; 3.7%), displaced intraocular lens or iris capture in 11 patients (12 eyes; 6.6%), ectopic pupil in five patients (five eyes; 2.7%), and severe inflammation in eight patients (12 eyes; 6.6%). There was cosmetically significant esotropia or exotropia in 24 patients (23 eyes; 12.7%).

Conclusion: The prognosis for vision was significantly poorer in unilateral and earlier onset cataract. The importance of early diagnosis, prompt treatment and vigilant postoperative follow up in this subgroup cannot be over‐emphasized.
Fatigue crack nucleation and growth in filled natural rubber
Authors: MARS W. V. , FATEMI A.
Published: September 2003

Rubber components subjected to fluctuating loads often fail due to nucleation and the growth of defects or cracks. The prevention of such failures depends upon an understanding of the mechanics underlying the failure process. This investigation explores the nucleation and growth of cracks in filled natural rubber. Both fatigue macro‐crack nucleation as well as fatigue crack growth experiments were conducted using simple tension and planar tension specimens, respectively. Crack nucleation as well as crack growth life prediction analysis approaches were used to correlate the experimental data. Several aspects of the fatigue process, such as failure mode and the effects of R ratio (minimum strain) on fatigue life, are also discussed. It is shown that a small positive R ratio can have a significant beneficial effect on fatigue life and crack growth rate, particularly at low strain range.
Axial fatigue of a gas‐nitrided quenched and tempered AISI 4140 steel: effect of nitriding depth
Authors: LIMODIN N. , VERREMAN Y. , TARFA T. N.
Published: September 2003

Fatigue testing under fully reversed axial loading (R=−1) and zero‐to‐tension axial loading (R= 0) was carried out on AISI 4140 gas‐nitrided smooth specimens. Three different treatment durations were investigated in order to assess the effect of nitriding depth on fatigue strength in high cycle fatigue. Complete specimens characterization, i.e., hardness and residual stresses profiles (including measurement of stabilized residual stresses) as well as metallographic and fractographic observations, was achieved to analyse fatigue behaviour. Fatigue of the nitrided steel is a competition between a surface crack growing in a compressive residual stress field and an internal crack or ‘fish‐eye’ crack growing in vacuum. Fatigue life increases with nitriding depth until surface cracking is slow enough for failure to occur from an internal crack. Unlike bending, in axial fatigue ‘fish‐eye’ cracks can initiate anywhere in the core volume under uniform stress. In these conditions, axial fatigue performance is lower than that obtained under bending and nitriding depth may have no more influence. In order to interpret the results, special attention was given to the effects of compressive residual stresses on the surface short crack growth (closure effect) as well as the effects of internal defect size on internal fatigue lives. A superimposed tensile mean stress reduces the internal fatigue strength of nitrided steel more than the surface fatigue strength of the base metal. Both cracking mechanisms are not equally sensitive to mean stress.
Dialogue and decision in a moral context
Authors: Ipperciel Donald
Published: September 2003

One of the most widely accepted tenets in postmetaphysical normative ethics is the principle of dialogue as a foundational authority. Conceptually, the dialogical model is valuable, in that it allows a binding yet mutable underpinning of moral discourse. However, dialogue has its limits. The main drawback lies in the fact that deliberations can be very lengthy, perhaps even infinite. In other words, deliberation does not always lend itself to action. From the vantage point of applied ethics, in this case, bioethics and forensic ethics, this is not a minor shortcoming since these disciplines are concerned with situations involving some sort of urgency. Aporia is not an option in most cases. It is thus pressing to consider the moment of decision inherent to moral judgement and action that puts an end to dialogue. From the realm of abstract norm justification, one must move on to the contextualist discourse of application. To be rational, however, decision must avoid authoritativeness or any type of arbitrariness. What, then, could serve as a reasonable criteria for the rational application of norms? What aspects should be envisaged for a sound reflective decision? This paper will attempt to sketch some answers that could contribute to the question of the necessary contextual application of accepted norms by paying heed to, systemizing and sometimes finding fault in the arguments given by judges who had to settle cases touching sensitive moral issues.
Researching nursing practice: does person‐centredness matter?1
Authors: McCormack Brendan
Published: September 2003

Person‐centredness is common speak in nursing and health care literature. Increasingly there is an expectation that practitioners adopt person‐centred principles in their practice and organizations are expected to respect the values of the service user. However, in the research methodology literature, there is little explicit attention paid to the concept of person‐centredness in research practice. Instead, there continues to be a reliance on traditional ‘ethical principles’ to guide effectiveness in research work. This paper argues that the principles of person‐centredness that are espoused in nursing practice should also underpin nursing and health care research. A framework for person‐centred research is proposed and issues concerning its implementation in practice are discussed.
Language deterioration in four Japanese–Portuguese bilingual patients with Alzheimer's disease: a trans‐cultural study of Japanese elderly immigrants in Brazil
Authors: MEGURO Kenichi , SENAHA Mirna LH , CARAMELLI Paulo , ISHIZAKI Junichi , CHUBACCI Rosa YS , MEGURO Mitsue , AMBO Hideo , NITRINI Ricardo , YAMADORI Atsushi
Published: September 2003

Background:  Bilingualism is an area of linguistics that has been investigated in aphasic patients. However, bilingualism and Alzheimer's disease (AD) have not been fully investigated despite the fact that language impairment is a frequent symptom of AD. Brazil has the greatest number of Japanese immigrants and, consequently, there are many bilingual people who are fluent in both Japanese and Portuguese in Brazil.

Methods:  Using the results from a previous epidemiological survey, we found four AD patients who were fluent in both Japanese and Portuguese before developing AD, and performed the following evaluations in both languages: confrontation naming, oral reading ability, vocabulary comprehension (matching words and drawings), written lexical decision and the Western Aphasia Battery (WAB).

Results:  All patients demonstrated impaired naming ability in both languages. Oral reading ability was most impaired in the case of Kanji, followed by irregular words in Portuguese. The patients could recognize and pronounce Kana perfectly, and regular Portuguese words almost perfectly. In the severest case, the patient showed disturbed lexical comprehension and lexical decision, especially when faced with Kanji. The WAB classified three patients as having anomic aphasia in both languages, whereas in the severest case the patient was classified as having anomic aphasia in Portuguese and Wernicke aphasia in Japanese.

Conclusion:  These results may reflect different patterns in language deterioration as AD progresses, with Kanji being more readily affected by the disease than Kana and Portuguese. This is the first study to focus on Japanese–Portuguese bilingualism in AD patients.
Clinical experience of quetiapine in 24 elderly patients with delirium
Authors: OMURA Keiko , AMANO Naoji
Published: September 2003

Background:  A recent study reported that patients with delirium responded well to the administration of atypical antipsychotic agents. In the present study we administered quetiapine to patients with delirium and obtained good results.

Methods:  This study included 24 patients (10 men, 14 women), referred to the psychiatry department during admission to other hospital departments, who were diagnosed as having delirium according to the diagnostic and statistical manual of mental disorders (4th edition) (DSM‐IV) between April 2001 and September 2002. The mean age of the patients was 76.5 years (men 71.0 years; women 80.5 years). An initial dose of quetiapine was established at 25–50 mg/day. Depending on the symptoms, the dose and frequency were increased as required. According to Trzepacz's delirium rating scale (DRS), the treatment response was evaluated prior to the administration of quetiapine and 1, 3, 5 and 7 days after administration began.

Results:  Prior to the administration of quetiapine, the mean DRS score was 18.1. The mean scores were 12.2, 10.8, 9.7 and 8.9 after 1, 3, 5 and 7 days of quetiapine administration, respectively. These values were significantly lower than the value before administration (P < 0.001). Seven days after the administration of quetiapine commenced, the total DRS score was lower than the cutoff point (12) in 20 patients (83.3%). In 18 patients (75.0%), delirium was clinically relieved. Doses ranged from 25 mg/day to 125 mg/day, with a mean dose of 54.7 mg/day. With respect to the administration method, the majority of patients (i.e. 13 patients) received quetiapine once per day (after dinner). Somnolence was observed in three patients as a side‐effect of quetiapine administration. However, this side‐effect improved after 1–2 days, without decreasing the dose.

Conclusions:  Quetiapine may be useful for controlling delirium and concerning side‐effects and extrapyramidal symptoms were not recorded in the present study. Thus, it is appropriate to trial quetiapine in the treatment of delirium.
Visual motor gestalt task indicates that ‘deficit schizophrenics’ become severely disturbed with age
Authors: TATEYAMA Masato , TAKEDA Ryutaro , TOKUNO Motoharu , HASHIMOTO Motohide , FUKUKAWA Yasuyuki , OSADA Hisao , UEMATSU Yoshinobu
Published: September 2003

Background:  ‘Deficit syndrome’ in people with schizophrenia is one of the primary negative symptoms that might be linked to organic brain changes. In the present study the visual motor gestalt functions of schizophrenics using the Bender–Gestalt test (BGT) were assessed.

Methods:  Fifty‐eight chronic schizophrenics (DSM‐IV) were the subjects who took part in this study (26 men and 32 women with an average age of 53.5 years and a mean duration of illness of 31.4 years). We performed BGT and used the scoring system of Pascal–Suttell. At the same time patients’ symptoms were also rated using the brief psychiatric rating scale and the Simpson and Angus extrapyramidal symptom scale from Keio University. The subjects were also divided into ‘deficit’ and ‘non‐deficit’ groups according to the criteria of Carpenters et al. 1988.

Results:  The mean total BGT score for all subjects was 48.2, which was midway between the scores for normal subjects and patients with organic brain diseases. The BGT score for subjects correlated significantly with age (rs = 0.44, P < 0.01). Although no significant difference in the total BGT scores existed between the ‘deficit’ and ‘non‐deficit’ groups, the correlation with age was more marked in the deficit subjects than in the non‐deficit subjects (rs = 0.725, P < 0.01 vs rs = 0.2705, P < 0.1). There also existed significant correlations between the BGT scores and the total scores of parkinsonism (rs = 0.265, P < 0.05). The multiple regression analysis of the BGT scores, nevertheless, revealed a higher correlation with age rather than parkinsonism scores of patients with schizophrenia, especially in the deficit group (β = 0.559, contribution = 31.8% vs β = 0.295, contribution = 9.1%).

Conclusion:  Performance of the visual motor gestalt task revealed that deficit subjects become severely disturbed with age, suggesting that these individuals are more vulnerable to the brain aging process.
Modelling cartilage mechanobiology
Authors: Carter Dennis R. , Wong Marcy
Published: September 2003

The growth, maintenance and ossification of cartilage are fundamental to skeletal development and are regulated throughout life by the mechanical cues that are imposed by physical activities. Finite element computer analyses have been used to study the role of local tissue mechanics on endochondral ossification patterns, skeletal morphology and articular cartilage thickness distributions. Using single–phase continuum material representations of cartilage, the results have indicated that local intermittent hydrostatic pressure promotes cartilage maintenance. Cyclic tensile strains (or shear), however, promote cartilage growth and ossification. Because single–phase material models cannot capture fluid exudation in articular cartilage, poroelastic (or biphasic) solid/fluid models are often implemented to study joint mechanics. In the middle and deep layers of articular cartilage where poroelastic analyses predict little fluid exudation, the cartilage phenotype is maintained by cyclic fluid pressure (consistent with the single–phase theory). In superficial articular layers the chondrocytes are exposed to tangential tensile strain in addition to the high fluid pressure. Furthermore, there is fluid exudation and matrix consolidation, leading to cell ‘flattening’. As a result, the superficial layer assumes an altered, more fibrous phenotype. These computer model predictions of cartilage mechanobiology are consistent with results ofin vitrocell and tissue and molecular biology experiments.
Vaporware as a Means of Entry Deterrence
Authors: Haan Marco A.
Published: September 2003

Firms in the computer industry are often accused of vaporware, the untruthful pre‐announcement of a new version of their product. By claiming they have a new product, critics argue, these firms try to deter potential entrants. The paper analyzes this phenomenon. It shows that vaporware is an equilibrium strategy in a signaling game in which the possibility to market a new product is private information. In this model, the possibility of vaporware can hurt consumers, also in the case the incumbent does have a new version of its product. The welfare effects of vaporware are ambiguous.
The Usefulness of the Supervisory Board Report in China
Authors: Dahya Jay , Karbhari Yusuf , Xiao Jason Zezong , Yang Mei
Published: September 2003

Chinese listed companies adopt a two‐tier board structure, a Board of Directors (BoD) and a Supervisory Board. They are also required to provide in their annual reports a supervisory board report (SBR). However, Congquin, a listed company, failed to issue a SBR in its 1998 annual report. This study specifically investigates the usefulness of the SBR by examining the stock market reaction to Congquin's SBR omission. The study also examines the Supervisory Board's reporting process and users’ perceived usefulness of the SBR through interviews with directors, supervisory board members and senior executives of 16 listed companies. Discussions were also held with financial analysts, regulatory officials and academics. Our event study suggests that the absence of the SBR in Congquin's 1998 annual report caused a negative market reaction suggesting that investors had considered the SBR and the Supervisory Board important and were discouraged by the problems manifested by the absence of the SBR. Our interviews reveal that the usefulness of the SBR depends on the role that the Supervisory Board plays in corporate governance. If the Supervisory Board is an honoured guest, a friendly advisor, or a censored watchdog, it is unlikely that the SBR will convey much useful information. By contrast, if the Supervisory Board acts as an independent watchdog, then the SBR would be useful. Given the fact that the Supervisory Board in most of the companies that participated in the interviews fell into the first three categories, there remains a strong need to improve the usefulness of the SBR and strengthen the functioning of the Supervisory Board.
Stock Valuation and Learning about Profitability
Authors: Pástor Ľuboš , Pietro Veronesi
Published: September 2003

We develop a simple approach to valuing stocks in the presence of learning about average profitability. The market‐to‐book ratio (M/B) increases with uncertainty about average profitability, especially for firms that pay no dividends. M/B is predicted to decline over a firm's lifetime due to learning, with steeper decline when the firm is young. These predictions are confirmed empirically. Data also support the predictions that younger stocks and stocks that pay no dividends have more volatile returns. Firm profitability has become more volatile recently, helping explain the puzzling increase in average idiosyncratic return volatility observed over the past few decades.
Currency Orders and Exchange Rate Dynamics: An Explanation for the Predictive Success of Technical Analysis
Authors: Osler Carol L.
Published: September 2003

This paper documents clustering in currency stop‐loss and take‐profit orders, and uses that clustering to provide an explanation for two familiar predictions from technical analysis: (1) trends tend to reverse course at predictable support and resistance levels, and (2) trends tend to be unusually rapid after rates cross such levels. The data are the first available on individual currency stop‐loss and take‐profit orders. Take‐profit orders cluster particularly strongly at round numbers, which could explain the first prediction. Stop‐loss orders cluster strongly just beyond round numbers, which could explain the second prediction.
The Presidential Puzzle: Political Cycles and the Stock Market
Authors: Santa‐Clara Pedro , Valkanov Rossen
Published: September 2003

The excess return in the stock market is higher under Democratic than Republican presidencies: 9 percent for the value‐weighted and 16 percent for the equal‐weighted portfolio. The difference comes from higher real stock returns and lower real interest rates, is statistically significant, and is robust in subsamples. The difference in returns is not explained by business‐cycle variables related to expected returns, and is not concentrated around election dates. There is no difference in the riskiness of the stock market across presidencies that could justify a risk premium. The difference in returns through the political cycle is therefore a puzzle.
Empirical Tests for Stochastic Dominance Efficiency
Authors: Post Thierry
Published: September 2003

We derive empirical tests for the stochastic dominance efficiency of a given portfolio with respect to all possible portfolios constructed from a set of assets. The tests can be computed using straightforward linear programming. Bootstrapping techniques and asymptotic distribution theory can approximate the sampling properties of the test results and allow for statistical inference. Our results could provide a stimulus to the further proliferation of stochastic dominance for the problem of portfolio selection and evaluation. Using our tests, the Fama and French market portfolio is significantly inefficient relative to benchmark portfolios formed on market capitalization and book‐to‐market equity ratio.
Do Spin‐offs Expropriate Wealth from Bondholders?
Authors: Maxwell William F. , Rao Ramesh P.
Published: September 2003

A wealth transfer from bondholders to stockholders is one of several hypotheses used to explain stockholder gains on the announcement of a spin‐off. However, previous empirical research has not found systematic evidence supporting the wealth expropriation hypothesis. Using a larger sample with comprehensive bond data, we find evidence consistent with wealth expropriation. Bondholders, on average, suffer a significant negative abnormal return during the month of the spin‐off announcement. However, even accounting for the loss to the bondholders, the aggregate value of the publicly traded debt and equity increases on a spin‐off announcement, suggesting that the wealth expropriation hypothesis is not a complete explanation of the stockholder gains. In explaining the magnitude of the losses to bondholders, we find they are a function of the loss in collateral in the spun‐off subsidiary and the level of financial risk of the parent firm. Consistent with a loss to bondholders, firms are more likely to have their credit rating downgraded than upgraded after a spin‐off. Additionally, consistent with the wealth transfer hypothesis, losses to bondholders tend to be more severe, the larger the gains to shareholders.
Family Firms
Authors: Burkart Mike , Panunzi Fausto , Shleifer Andrei
Published: September 2003

We present a model of succession in a firm owned and managed by its founder. The founder decides between hiring a professional manager or leaving management to his heir, as well as on what fraction of the company to float on the stock exchange. We assume that a professional is a better manager than the heir, and describe how the founder's decision is shaped by the legal environment. This theory of separation of ownership from management includes the Anglo‐Saxon and the Continental European patterns of corporate governance as special cases, and generates additional empirical predictions consistent with cross‐country evidence.
Organization of Human Papillomavirus Productive Cycle during Neoplastic Progression Provides a Basis for Selection of Diagnostic Markers
Authors: Middleton Kate , Peh Woei , Southern Shirley , Griffin Heather , Sotlar Karl , Nakahara Tomomi , El-Sherif Amira , Morris Lesley , Seth Rashmi , Hibma Merilyn , Jenkins David , Lambert Paul , Coleman Nicholas , Doorbar John
Published: September 2003

The productive cycle of human papillomaviruses (HPVs) can be divided into discrete phases. Cell proliferation and episomal maintenance in the lower epithelial layers are followed by genome amplification and the expression of capsid proteins. These events, which occur in all productive infections, can be distinguished by using antibodies to viral gene products or to surrogate markers of their expression. Here we have compared precancerous lesions caused by HPV type 16 (HPV16) with lesions caused by HPV types that are not generally associated with human cancer. These include HPV2 and HPV11, which are related to HPV16 (supergroup A), as well as HPV1 and HPV65, which are evolutionarily divergent (supergroups E and B). HPV16-induced low-grade squamous intraepithelial lesions (CIN1) are productive infections which resemble those caused by other HPV types. During progression to cancer, however, the activation of late events is delayed, and the thickness of the proliferative compartment is progressively increased. In many HPV16-induced high-grade squamous intraepithelial lesions (CIN3), late events are restricted to small areas close to the epithelial surface. Such heterogeneity in the organization of the productive cycle was seen only in lesions caused by HPV16 and was not apparent when lesions caused by other HPV types were compared. By contrast, the order in which events in the productive cycle were initiated was invariant and did not depend on the infecting HPV type or the severity of disease. The distribution of viral gene products in the infected cervix depends on the extent to which the virus can complete its productive cycle, which in turn reflects the severity of cervical neoplasia. It appears from our work that the presence of such proteins in cells at the epithelial surface allows the severity of the underlying disease to be predicted and that markers of viral gene expression may improve cervical screening.
N-Linked Glycans with Similar Location in the Fusion Protein Head Modulate Paramyxovirus Fusion
Authors: von Messling Veronika , Cattaneo Roberto
Published: September 2003

N-linked glycans not only orchestrate the folding and intracellular transport of viral glycoproteins but also modulate their function. We have characterized the three glycans attached to fusion (F) proteins of the morbilliviruses canine distemper virus and measles virus. The individual
Morbillivirus
glycans have similar functional properties: the glycan at position 68 is essential for protein transport, and those at positions 36 and 75 modulate fusion (numbering according to the Newcastle disease virus [NDV] F protein sequence). Based on the crystal structure of the NDV F protein, we then predicted the locations of the
Morbillivirus
glycans: the glycan at position 36 is located in the F protein head, and those at positions 68 and 75 are located near the neck-stalk interface. NDV position 36 is not occupied by a glycan; the only glycan in that F protein head also has a fusion control function and grows from residue 366, located only 6 Å from residue 36. We then exchanged the glycan at position 36 with the glycan at position 366 and showed functional complementation. Thus, structural information about the F proteins of
Paramyxoviridae
coupled with functional analysis disclosed a location in the protein head into which fusion-modulating glycans independently evolved.
Yeast-Derived Human Immunodeficiency Virus Type 1 p55gagVirus-Like Particles Activate Dendritic Cells (DCs) and Induce Perforin Expression in Gag-Specific CD8+T Cells by Cross-Presentation of DCs
Authors: Tsunetsugu-Yokota Yasuko , Morikawa Yuko , Isogai Maya , Kawana-Tachikawa Ai , Odawara Takashi , Nakamura Tetsuya , Grassi Fernanda , Autran Brigitte , Iwamoto Aikichi
Published: September 2003

To evaluate the immunogenicity of human immunodeficiency virus (HIV) type 1 p55gagvirus-like particles (VLPs) released by budding from yeast spheroplasts, we have analyzed the effects of yeast VLPs on monocyte-derived dendritic cells (DCs). Yeast VLPs were efficiently incorporated into DCs via both macropinocytosis and endocytosis mediated by mannose-recognizing receptors, but not the mannose receptor. The uptake of yeast VLPs induced DC maturation and enhanced cytokine production, notably, interleukin-12 p70. We showed that yeast membrane components may contribute to DC maturation partly through Toll-like receptor 2 signaling. Thus, Gag particles encapsulated by yeast membrane may have an advantage in stimulating Gag-specific immune responses. We found that yeast VLPs, but not the control yeast membrane fraction, were able to activate both CD4+and CD8+T cells of HIV-infected individuals. We tested the effect of cross-presentation of VLP by DCs in two subjects recruited into a long-term nonprogressor-slow progressor cohort. When yeast VLP-loaded DCs of these patients were cocultured with peripheral blood mononuclear cells for 7 days, approximately one-third of the Gag-specific CD8+T cells were activated and became perforin positive. However, some of the Gag-specific CD8+T cells appeared to be lost during in vitro culture, especially in a patient with a high virus load. Our results suggest that DCs loaded with yeast VLPs can activate Gag-specific memory CD8+T cells to become effector cells in chronically HIV-infected individuals, but there still remain unresponsive Gag-specific T-cell populations in these patients.