bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of stationary plasma thrusters using two-dimensional fully kinetic simulations
Authors: Adam J. C. , Héron A. , Laval G.
Published: December 2003

Stationary plasma thrusters are devices that use crossed electric and magnetic fields to accelerate ions to high velocities. Ions are created by collisional ionization of a propellant gas with electrons injected from a hollow cathode external to the thruster. A major issue is the electron transport through the magnetic field. It is known to exceed considerably the values predicted by the classical theory. Various 2D models have shown that wall collisions, which have often been invoked as the origin of this anomalous transport, are in fact insufficient. Anomalous turbulent transport has to be added to the model to recover an adequate conductivity. In the present paper the first 2D kinetic model that shows that, indeed, plasma turbulence can explain the observed conductivity is presented. Without any free parameter the model is able to reproduce numerous experimental features. At the end of the paper a preliminary theoretical analysis of the observed instability is provided.
Fractional generalization of Liouville equations
Authors: Tarasov Vasily E.
Published: December 2003

In this paper fractional generalization of Liouville equation is considered. We derive fractional analog of normalization condition for distribution function. Fractional generalization of the Liouville equation for dissipative and Hamiltonian systems was derived from the fractional normalization condition. This condition is considered as a normalization condition for systems in fractional phase space. The interpretation of the fractional space is discussed.
Rarefaction effects on shear driven oscillatory gas flows: A direct simulation Monte Carlo study in the entire Knudsen regime
Authors: Park Jae Hyun , Bahukudumbi P. , Beskok Ali
Published: December 2003

A complete mathematical description of oscillatory Couette flows within the framework of kinetic theory is not available in the literature. Motivated by this and their vast engineering applications, we present a parametric study of time-periodic oscillatory Couette flows using the unsteady direct simulation Monte Carlo (DSMC) method. Computations are performed as a function of the Knudsen (Kn) and Stokes (β) numbers, in the entire Knudsen regime (Kn⩽100) and a wide range of Stokes numbers (β⩽7.5). The DSMC results are validated using a recently developed semianalytical/empirical model that is applicable for quasisteady flows (β⩽0.25) in the entire Knudsen regime, and for any Stokes number flow in the slip flow regime (Kn⩽0.1). In addition, we derived an analytical solution of the linearized collisionless Boltzmann equation for oscillatory Couette flows, and utilized this to validate the DSMC results in the free-molecular flow regime. Dynamic response of the flow, including the velocity profiles, phase angle, wave speed, shear stress, and the penetration depth for high Stokes number flows are presented. Increasing the Stokes number at fixed Kn, we observed formation of “bounded Stokes layers,” as expected. However, increasing the Knudsen number at fixed β results in “bounded rarefaction layers,” where the penetration depth continuously decreases with increasing the Kn. Interplay between the rarefaction and unsteadiness contributes to this interesting flow physics, and also introduces a new characteristic length scale to the problem.
Identifying parameter by identical synchronization between different systems
Authors: Huang Debin , Guo Rongwei
Published: December 2003

In this paper, parameters of a given (chaotic) dynamical system are estimated from time series by using identical synchronization between two different systems. This technique is based on the invariance principle of differential equations, i.e., a dynamical Lyapunov function involving synchronization error and the estimation error of parameters. The control used in this synchronization consists of feedback and adaptive control loop associated with the update law of estimation parameters. Our estimation process indicates that one may identify dynamically all unknown parameters of a given (chaotic) system as long as time series of the system are available. Lorenz and Rössler systems are used to illustrate the validity of this technique. The corresponding numerical results and analysis on the effect of noise are also given.
Tissue‐Engineered Human Nasal Septal Cartilage Using the Alginate‐Recovered‐Chondrocyte Method
Authors: Chia Stanley H. , Schumacher Barbara L. , Klein Travis J. , Thonar Eugene J.‐M.A. , Masuda Koichi , Sah Robert L. , Watson Deborah
Published: December 2003

Objectives Tissue engineering of nasal septal cartilage has numerous potential applications in craniofacial reconstruction. Chondrocytes suspended in alginate gel have been shown to produce a substantial cell‐associated matrix. The objective of this study was to determine whether cartilage tissue could be generated using the alginate‐recovered‐chondrocyte (ARC) method, in which chondrocytes are cultured in alginate as an intermediate step in tissue fabrication.

Methods Nasal septal chondrocytes from five patient donors were isolated by enzymatic digestion, then expanded in monolayer culture. At confluency, a portion of those cells were seeded at high density onto a semipermeable membrane and cultured for 14, 21, or 28 days (monolayer group). The remaining cells were suspended in alginate and cultured until a cell‐associated matrix was observed (10–17 days). Cells and their associated matrix were released from alginate (ARC group), seeded onto a semipermeable membrane, and cultured as already described. DNA (Hoechst 33258 Assay), glycosaminoglycan (GAG; dimethylmethylene blue assay), and collagen (hydroxyproline assay) were analyzed biochemically. Immunohistochemistry was performed to assess expression of collagens type I and type II. Histochemistry was performed to localize cells accumulating sulfated GAG (Alcian blue stain).

Results The ARC constructs, in contrast to the monolayer constructs, had substantial structural stability and the histologic and gross appearance of cartilaginous tissue. ARC constructs demonstrated significantly greater GAG and collagen accumulation than monolayer constructs (P < .05). Histologic analysis revealed substantial GAG and collagen type II production and only moderate collagen type I production. The composition of the matrix was thus similar to that of native human septal cartilage.

Conclusions Tissue‐engineered human nasal septal cartilage using the ARC method has the histologic and gross appearance of native cartilage and has biochemical composition more like that of native cartilage than monolayer constructs. This is the first report of human nasal septal neocartilage formation without the use of biodegradable scaffolds.
Internal Jugular Vein Thrombosis and Deep Neck Infection from Intravenous Drug Use: Management Strategy
Authors: Lin Doris , Reeck Jay B. , Murr Andrew H.
Published: December 2003

Objective Internal jugular vein thrombosis (IJVT) manifests in multiple clinical scenarios including traumatic, neoplastic, and infectious processes. No clear management algorithm exists for IJVT in the setting of deep neck infections. This study examines the cause, diagnosis, and treatment strategy for IJVT in the setting of deep neck infections caused by intravenous drug use (IVDU).

Study Design Retrospective chart review

Methods The clinical, radiographic, and laboratory data of 11 IVDU patients with deep neck infections and IJVT are reviewed in a retrospective fashion. The patients were seen in a university tertiary care facility.

Results Eleven patients with deep neck infections, recent history of IVDU, and concurrent IJVT were identified. All patients underwent computed tomography (CT) scanning. Antibiotic therapy was instituted in all cases, abscesses were treated invasively with aspiration or incision and drainage, and no veins were ligated or resected. Three patients received anticoagulation. One patient had bilateral IJVT with thrombus extension through the sigmoid sinus to the lateral sinus. This patient received anticoagulation and developed bacteremia. No further IJVT complications have been diagnosed at an average of 14 months postintervention.

Conclusion IJVT and deep neck infection caused by IVDU constitute a clinical entity present even in the modern day era of antibiotic therapy. Aggressive antibiotic therapy and surgical intervention for the deep neck infection is recommended. The indications for anticoagulation remain variable. Although anticoagulation is often recommended in the presence of thrombus progression or septic emboli, the very presence of IJVT does not mandate the need for anticoagulation. Ligation or resection of the thrombosed vein may be reserved for selected cases, but was not necessary in our series.
Prothrombotic Factors in Children with Otitis Media and Sinus Thrombosis
Authors: Oestreicher‐Kedem Yael , Raveh Eyal , Kornreich Liora , Yaniv Isaac , Tamary Hannah
Published: December 2003

Objective Venous sinus thrombosis (VST) is the second most common intracranial complication of acute otitis media (AOM). There is some evidence that hereditary and acquired prothrombotic disorders are risk factors for VST. The aim of the present study was to evaluate whether children with AOM complicated VST have a prothrombotic tendency, which might have important therapeutic and preventive implications.

Study Design Retrospective.

Methods The files of children hospitalized at Schneider Children's Medical Center of Israel, a tertiary referral center, from 1999 to 2002, because of AOM complicated by acute mastoiditis and VST were reviewed. All children underwent laboratory work‐up for hypercoagulability.

Results Seven children met the study criteria. Of these, five had prothrombotic disorders, namely elevated levels of lipoprotein apolipoprotein (Lp[a]) (n = 4), antibodies to beta 2‐glycoprotein and to cardiolipin (markers of antiphospholipid syndrome) (n = 4), and heterozygosity for factor V Leiden mutation (n = 1). One child had three abnormalities, two children had two abnormalities, and two children had one abnormality.

Conclusions A prothrombotic tendency may exist in children with AOM complicated by mastoiditis and VST. Further studies are needed to evaluate its extent.
Distribution of 3‐Nitrotyrosine in the Nasal Polyps Of Atopic Patients
Authors: Ruffoli R. , Ursino F. , Fattori B. , Scavuzzo M. C. , Paparelli A. , Gesi M. , Rocchi V. , Giambelluca M. A. , Giannessi F.
Published: December 2003

Objective To investigate whether formation of nitrotyrosine in the nasal polyps of atopic patients occurs.

Study Design A nonrandomized, retrospective, controlled qualitative and quantitative study.

Methods Nasal polyp tissue samples were acquired from 12 atopic patients. Control fragments of nasal mucosa were taken from 10 patients undergoing corrective surgery of the nasal septum. For routine histologic examinations, hematoxylin‐eosin staining was used. Low‐magnification microscopy was designed to yield pathologic characteristics and high magnification to quantify the number of eosinophils in the subepithelial connective tissue. Presence of nitrotyrosine was assessed by immunohistochemical method.

Results Hematoxylin‐eosin staining revealed presence of numerous eosinophils in the epithelium and in the subepithelial connective tissue. All polyps were characterized by epithelial damage. Nitrotyrosine was present in the eosinophils, in the ciliated cell, and in cells of the damaged epithelium. Goblet cells, glands, and vessels were found to be negative. No significant differences concerning the localization of nitrotyrosine were recognized among the examined nasal polyps.

Conclusions Nitrotyrosine immunohistochemical staining in nasal‐polyp tissues suggested the existence of progressive epithelium injury caused by peroxynitrite. Consequences of peroxynitrite formation in eosinophils remain to be precisely established. The lack of nitrotyrosine in glands and blood vessels indicated that peroxynitrite does not have a significant role in the vascular and glandular dysfunction of nasal polyps.
Microbiology of Recurrent Acute Rhinosinusitis
Authors: Brook Itzhak , Frazier Edith H.
Published: December 2003

Objective We undertook to evaluate the microbiology of recurrent acute rhinosinusitis.

Methods Repeated aspirations of maxillary sinus secretions by endoscopy were performed in eight patients over a period of 98 to 185 days.

Results Bacteria were recovered for all 25 aspirates. A total of 31 isolates—14 Streptococcus pneumoniae, 11 Haemophilus influenzae, 5 Moraxella catarrhalis, and 1 Staphylococcus aureus—were recovered. The organism persisted in consecutive cultures in 13 instances and were eliminated in 8, and new organisms emerged in 6 instances. An increase in antimicrobial resistance was noted in 5 instances (3 in S. pneumoniae and 2 H. influenzae).

Conclusions This study illustrates the microbial dynamics of recurrent acute rhinosinusitis, with the changes in microbial findings and increased bacterial resistance that occurs over time.
Orbitozygomatic Resection of Meningiomas of the Orbit
Authors: Ducic Yadranko
Published: December 2003

Objective To review our experience with the surgical treatment of orbital meningiomas.

Methods A retrospective review of all patients presenting to the author for treatment of orbital meningiomas over a 5 year period with a minimum of 1 year follow‐up were included in this review. Demographic data, surgical approaches, and recurrence rates were documented.

Results A total of seven patients were treated for this condition. Complete surgical resection was achieved with the outlined technique in 71% of the patients, and gross tumor removal was achieved in the remaining 29% of patients. This latter group received postoperative gamma‐knife treatment, and only a single patient has evidence of persistent disease that is nonprogressive at 3‐year follow‐up.

Conclusions Meningioma of the orbit, whether primary (ectopic) or secondary. should be treated as at other sites with complete surgical excision if possible. Gamma knife or intensity modulated radiotherapy may be useful for residual microscopic disease. Surgical clearance is facilitated with the broad field exposure afforded by the orbitozygomatic approach outlined in the article, with particular attention directed at positive identification of key landmarks particularly in retro‐orbital and cavernous sinus extension.
Feature Review Section
Authors: House John , Borchardt‐Hume Achim , Strupp Joachim
Published: December 2003

Neret, Gilles (ed.) Monet: Catalogue Raisonné

Beudert, Monique (ed.) The Froelich Foundation. German and American Art from Beuys and Warhol

Luchs, Alison Tullio Lombardo and Ideal Portrait Sculpture in Rennaissance Venice, 1490–1530
Feature Reviews
Authors: Pollock Griselda , Steer John , Hopkins Andrew , Lynton Norbert
Published: December 2003

Van Heughten, Sjraar Vincent Van Gogh Drawings. Volume 1: The Early Years 1880–1883

Rewald, John, in collaboration with Walter Feilchenfeldt and Jayne Warman The Paintings of Paul Cézanne: A Catalogue Raisonné

Rewald, John Cézanne: A Biography

Marder, T.A. Bernini&aposs Scala Regia at the Vatican Palace

Barral i Altet, Xavier and others Sculpture — From Antiquity to the Present
Furniture of the Century
Authors: Frumkin Allan
Published: December 2003

John Neuhart, Marilyn Neuhart, with Ray Eames Eames Design: The Work of the Office of Charles and Ray Eames

Pat Kirkham Charles and Ray Eames: Designers of the Twentieth Century

Donald Albrecht (ed.) The Work of Charles and Ray Eames: A Legacy of Invention
In the Name of Pollock
Authors: Harris Jonathan
Published: December 2003

Book reviewed in this article:

Kirk Varnedoe and Pepe Karmel Jackson Pollock
Masterpieces in Little: The Portrait Miniature
Authors: Binnie Margaret
Published: December 2003

Books reviewed in this article:

Katherine Coombs The Portrait Miniature in England

Edited by Jeffrey M Muller and Jim Murrell Edward Norgate: Miniatura or the Art of Limning

Graham Reynolds British Portrait Miniatures: Fitzwilliam Museum Handbooks

Richard Walker Miniatures: a selection of miniatures in the Ashmolean Museum

Richard Walker Miniatures: 300 Years of the English Miniature illistrated from the Collections of the National Portrait Gallery
Describing the Virgin
Authors: Winston Jessica
Published: December 2003

Descriptions of the Virgin began to emerge in Italian popular devotional literature in the fifteenth century and in theological texts in the sixteenth century. In such texts, worshippers and readers were no longer left to imagine the appearance of the Virgin in prayer. Rather, her image was given in a description. And this represents a complete shift away from the tradition in the West, a tradition that originated in St Augustine's De Trinitate. This tendency to describe the physical appearance of the Virgin for meditation via texts also existed, although inconsistently, in paintings of her. In the itinerant artist Antonello da Messina’s two images of the Annunziata (Munich and Palermo, c.1470) the painter appropriates the pictorial structure of portraiture to depict her. It is the portrait–like format and all its associations that confirm the reality of this sacred person. The images must be thought of as pictorial examples of what one might call the urgency of similitude that pervaded devotional literature of the period. Because of the pressures of the Reformation and the suspicion with which images were viewed, beginning in the sixteenth century, Catholic theologians seemed to have used the idea of likeness to defend the use of images in devotion. The more the image was a reflection of its archetype, the less it was like an idol, or false image, hence the importance of the descriptions of the Virgin Mary.
Comparison of computer‐controlled administration of propofol with two manually controlled infusion techniques
Authors: Struys M. , Versichelen L. , Thas O. , Herregods L. , Rolly G.
Published: December 2003

Ninety women were studied in order to compare dose requirements and quality of anaesthesia between target‐controlled infusion and two manually controlled infusion schemes for propofol administration: group I received target‐controlled infusion for induction (4 μg.ml−1 target blood concentration, increased by 2 μg.ml−1 after 3 min if consciousness not lost), groups II and III received an induction bolus of propofol at infusion rates of 1200 or 600 ml.h−1, respectively, until loss of consciousness. Anaesthesia was maintained with propofol target‐controlled infusion in group I or by constant rate infusion in the other two groups. Computer simulations were used to calculate blood and effect‐site propofol concentrations. Mean induction times (SD) were 78 (65) s in group I versus 51 (10) s and 62 (12) s in groups II and III, respectively (p < 0.05 between groups II and III). Mean induction doses were: 1.31 (0.44), 2.74 (0.56) and 1.77 (0.43) mg.kg−1 and mean maintenance doses were 13.4 (3.55), 9.32 (1.71) and 9.97 (1.53) mg.kg−1.h−1 in groups I, II and III, respectively (p < 0.05 between all groups). There was a lower incidence of apnoea in group I than in groups II and III. There were no significant differences between the groups in other objective parameters of anaesthetic quality studied. Computer simulations showed an ‘overshoot’ in propofol blood and effect‐site concentration with manual induction and significantly higher maintenance levels with target‐controlled infusion.
Music in theatre: not so harmonious
Authors: Hawksworth C. , Asbury A. J. , Millar K.
Published: December 2003

Music played to staff in the operating theatre is thought to improve surgeons’ concentration but its effects on other theatre staff are unknown. We surveyed 200 anaesthetists to determine the prevalence of music playing in the operating theatre and anaesthetists’ attitudes to it. The response rate was 72% and of these 72% (104) worked in a theatre where music was played regularly. Around 26% of the sample felt that music reduced their vigilance and impaired their communication with other staff while 11.5% felt that music might distract their attention from alarms. Fifty‐one per cent felt that music was distracting when a problem was encountered during the anaesthetic.
Tumour cell killing using chemically engineered antibody constructs specific for tumour cells and the complement inhibitor CD59
Authors: HARRIS C L , KAN K S , STEVENSON G T , MORGAN B P
Published: December 2003

Immunotherapy using MoAbs is inefficient due to limited activation of human effectors by mouse antibodies and multiple protective mechanisms available to host cells against autologous complement. We have used chemically engineered antibody constructs and human complement in vitro to specifically target and kill neoplastic B lymphoid cells (Raji). Fab′γFcγ2 chimaeric antibody (specific for human CD37) was used to activate the classical pathway of human complement on Raji cells, whilst CD59 was neutralized using one of two different bispecific F(ab′γ)2 antibody constructs which contained both cell-targeting (anti-CD19 or anti-CD38) and CD59-neutralizing moieties. When either bispecific construct was used to neutralize CD59, 15–25% of cells were lysed. If CD55 was also neutralized using specific antibody, Raji cells were efficiently killed (70% lysis). When added to a mixture of target (Raji) and bystander (K562) cells, one bispecific antibody (anti-CD38 × anti-CD59) could be specifically delivered to Raji, avoiding significant uptake on CD59-expressing bystander cells (K562). The second bispecific antibody (anti-CD19 × anti-CD59) bound equally well to either cell type. Cell-specific targeting was dependent upon combination of a low-affinity anti-CD59 Fab′γ with a high-affinity anti-tumour cell Fab′γ. When Raji and K562 cells were mixed and incubated with a combination of the engineered constructs and anti-CD55 antibodies, Raji cell lysis (30–40%) was observed in the absence of K562 killing. We propose that combinations of these constructs may be of use for treatments such as ex vivo purging of autologous bone marrow or in vivo targeting of tumour cells.
Role of γδ T lymphocytes in the development of Behc¸et's disease
Authors: YAMASHITA N , KANEOKA H , KANEKO S , TAKENO M , ONEDA K , KOIZUMI H , KOGURE M , INABA G , SAKANE T
Published: December 2003

Phenotypic and functional properties of γδ T cells, which play an important role in mucocutaneous immunity, were examined to elucidate whether immunological abnormality in Behc¸et's disease may be related to a specific T cell population. We found that CD45RA+Vγ9+Vδ2+γδ T cells, which constitute a minor population of γδ T cells in healthy individuals, were increased in number in Behc¸et's disease irrespective of disease activity. This CD45RA+ subset of γδ T cells in the active, but not inactive, phase of this disease expressed IL-2Rβ and HLA-DR, suggesting that they are activated in vivo in active Behc¸et's disease. In addition, the CD45RA+γδ T cells produced extreme amounts of tumour necrosis factor and contained perforin granules. These data indicate that a phenotypically distinct subset of γδ T cells, CD45RA+CD45RO−Vγ9+Vδ2+, may contribute to immunological abnormalities which may lead to complexity of pathophysiology in Behc¸et's disease.
Proliferation and production of interferon-gamma (IFN-γ) and IL-4 in response to Staphylococcus aureus and Staphylococcal superantigen in childhood atopic dermatitis
Authors: CAMPBELL D E , KEMP A S
Published: December 2003

We have examined the cell-mediated immunity (CMI) to Staphylococcus aureus (S. aureus) and Staphylococcal enterotoxin B (SEB) in peripheral blood mononuclear cells (PBMC) from children with atopic dermatitis (AD) and from non-atopic child controls by measurement of proliferative responses and production of the cytokines IFN-γ and IL-4. PBMC from children with AD showed significantly higher proliferative responses to both S. aureus (P <0.01) and SEB (P < 0.05). Despite this enhanced proliferation, production of IFN-γ in response to S. aureus (P <0.001) and SEB (P < 0.01) from these PBMC was significantly diminished. In contrast, PBMC from children with AD were significantly more likely to produce IL-4 in response to S. aureus (P < 0.01). These findings demonstrate in vitro heightened CMI to S. aureus in children with AD, and implicate S. aureus as a potent inflammatory stimulant. Impaired IFN-γ production to S. aureus in vivo may result in failure to eradicate S. aureus from skin. The organism's persistence on skin would contribute to inflammation by causing continued T cell activation and release of pro-inflammatory mediators.
Analysis of rearranged immunoglobulin heavy chain variable region genes obtained from a bone marrow transplant (BMT) recipient
Authors: GLAS A M , NOTTENBURG C , MILNER E C B
Published: December 2003

Haematopoietic stem cell transplantation has been used for the treatment of many different malignant and non-malignant diseases. The immune system of transplant recipients must be regenerated from the transplant inoculum, and it is not surprising that many transplant recipients are deficient in generating specific antibody responses to exogenous stimuli. This B cell immunodeficiency in these patients is associated with clinically significant infections, although the underlying mechanism remains unknown. We have previously shown that the pattern of usage of VH genes was similar between healthy subjects and BMT recipients, indicating that the immunodeficiency was not due to a dramatic imbalance in VH utilization. However, motif-specific hybridization analysis indicated that the accumulation of somatic mutations was much greater among rearrangements in controls than in BMT recipients. The failure of BMT recipients to accumulate somatic mutations in rearranged VH genes correlates with an absence of IgD− B cells, and is consistent with a defect in antigen-driven B cell responses. In the current study, which extends those findings, we have determined the nucleotide sequences of 68 heavy chain rearrangements from one patient as well as 39 rearrangements from a healthy control. Analysis of these sequences made possible a more precise definition of variable region configuration and of the status of somatic mutation in this BMT recipient. The results validate the hybridization data and support the conclusion that, although somatic hypermutation and, by inference, antigen-driven responses are detected in BMT recipients, they are deficient compared with healthy subjects as late as 1 year after transplant.
A bias in the αβ T cell receptor variable region gene usage in Takayasu's arteritis
Authors: NITYANAND S , GISCOMBE R , SRIVASTAVA S , HJELMSTRO¨M P , SANJEEVI C B , SINHA N , GRUNEWALD J , LEFVERT A K
Published: December 2003

Takayasu's arteritis (TA) is a chronic large vessel vasculitis with a predilection for the aortic arch and its branches. T lymphocytes may be important in the pathogenesis, as they have been found to infiltrate the vascular lesions. To elucidate further the role of T cells in the disease, we studied circulating CD4+ and CD8+ T cells, expression of the activation marker (HLA-DR), marker for naive (CD45RA) and primed (CD45RO) cells and the different variable α/β (AV/BV) gene segments on them. The TCR AV/BV repertoire was studied using a panel of 15 T cell receptor (TCR) V-specific MoAbs by flow cytometry in 18 patients and 23 age- and sex-matched controls. Patients had a higher percentage of AV12S1 (P < 0.05), BV6S7 (P < 0.05) and BV9 (P < 0.001)-bearing CD4+ cells. Patients also had a higher frequency of expansions, i.e. of T cell populations with an abnormally high TCR AV/BV gene usage. In patients' CD4+ subset of cells, there were 22 expansions out of 231 analyses (9.5%), whereas in controls, four were expanded out of 310 analyses (1%) (P < 0.001). For CD8+ cells, the frequency of expansions was 32 in 231 analyses (14%) in patients and nine out of 304 analyses in controls (3%) (P < 0.01). In addition, there was a correlation between CD4+ expansions and disease activity; nine out of 10 patients with active disease in comparison with two out of eight patients with inactive disease (P < 0.01) had an expansion. Some of the expanded populations in patients were phenotypically characterized and observed to be HLA-DR<, CD28<, CD45RA< and CD45RO+, with a greater proportion being CD45RO+. Patients had a higher percentage of expression of HLA-DR on both CD4+ and CD8+ T cells (P < 0.01). The percentages of naive and primed CD4+ and CD8+ T cells, γδ+ T cells and natural killer cells were comparable to those in the control group.
High intratumoural level of cytokines mediates efficient regression of a rat histiocytoma
Authors: KHAR A , MURALIKRISHNA K , VARALAKSHMI C H
Published: December 2003

We have studied the role of cytokines in the spontaneous regression of AK-5 histiocytoma in syngeneic rats. Animals in which the tumour regresses show high levels of cytokines in the serum compared with animals which succumb to the tumour, and levels of IL-2, IL-4, IL-12, interferon-gamma (IFN-γ) and tumour necrosis factor-alpha (TNF-α) are significantly higher in tumour tissue of the former. Thus there is an association between rejection of the tumour and the levels of cytokines present in the tumour mass. Our results also suggest a predominant Th1-type of response in those rats that display early tumour rejection.
Altered sialylation of alveolar macrophages in HIV-1-infected individuals
Authors: PERRIN C , GIORDANENGO V , BANNWARTH S , BLAIVE B , LEFEBVRE J-C
Published: December 2003

In previous studies, we have demonstrated that O-glycans at the surface of HIV-1-infected cell lines were hyposialylated. Moreover, we and others have shown that HIV+ individuals produced autoantibodies that react with hyposialylated CD43, on T cell lines. Since the autoantigen responsible for this abnormal immune response was not easily found in the peripheral blood cells of corresponding patients, we searched for its possible presence in other sites. Using fluorescence staining of alveolar macrophages with various lectins, we show that the binding of the PNA lectin specific for asialo O-glycans is much more efficient on cells from HIV-1-infected individuals. Moreover, the degree of reactivity of PNA is correlated with the clinical stage of the illness.
Smashing Icons
Authors: George Victoria
Published: December 2003

Book reviewed in this article:

Peter Weibel and Bruno Latour (eds), Iconoclash
Blood gases in pregnancy at sea level and at high altitude
Authors: McAuliffe Fionnuala , Kametas Nikos , Krampl Elisabeth , Ernsting John , Nicolaides Kypros
Published: December 2003

Objective
1. To measure blood gases and minute ventilation in healthy women with normal pregnancies, compare with non‐pregnant women both at sea level and at high altitude; 2. to relate the results at altitude with duration of residence there.

Design
Cross‐sectional study.

Setting
Antenatal clinics at sea level in Lima, Peru and at high altitude 4300m in Cerro de Pasco, Peru.

Population
A total of 304 normal pregnant women between 7 and 41 weeks of gestation were studied, including 112 who lived at sea level and 192 at high altitude (4300m). For comparison 38 non‐pregnant women (19 at sea level and 19 at high altitude) were also studied.

Methods
Arterialised blood gases, haemoglobin, pulse oximetry and minute ventilation were measured once in each woman.

Main
outcome measures
PO2, PCO2, pH, haemoglobin, oxygen saturation, arterial oxygen content and minute ventilation and their relationship to gestation.

Results
PO2, PCO2, bicarbonate, base excess and oxygen saturation were lower in pregnancies at high altitude compared with sea level; pH, haemoglobin, arterial oxygen content and minute ventilation were higher. At high altitude oxygen saturation and haemoglobin decreased towards term resulting in a fall in arterial oxygen content at the end of pregnancy. Women whose family had lived at high altitude for at least three generations maintained their oxygenation throughout pregnancy better than women whose family had lived there for less than three generations.

Conclusions
In pregnancy at high altitude maternal adaptation appeared adequate in the first trimester but declined towards term. However, maternal oxygenation was maintained in those whose family had lived longest at high altitude suggesting a beneficial adaptation to a hypoxic environment, occurring over generations.
Outcome for children born after in utero laser ablation therapy for severe twin‐to‐twin transfusion syndrome
Authors: Sutcliffe A.G. , Sebire N.J. , Pigott A.J. , Taylor B. , Edwards P.R. , Nicolaides K.H.
Published: December 2003

Objective
To examine the postnatal development of a group of children born after in utero laser ablation therapy for severe twin‐to‐twin transfusion syndrome.

Design
Retrospective cohort outcome study involving assessment of neurodevelopment and physical well being.

Setting
Harris Birthright Centre, King's College Hospital, London.

Participants
Twins and singleton survivors treated via laser ablation therapy for twin‐to‐twin transfusion syndrome over a four‐year period.

Methods
Of 54 families contacted to participate in the study, who had been treated for twin‐to‐twin transfusion syndrome during a four‐year period, 24 families attended for paediatric assessment; 12 pairs of twins and 12 singleton survivors were assessed for perinatal, neurological and neurodevelopmental outcome using the Griffiths scales of mental development. A further 20 families were assessed via a proforma after contact with their general practitioner. A comparison of these groups showed no significant differences in sociodemographic factors or severity of disease between responders (44 families, 81.5%) and non‐responders (10 families).

Results
The group of children assessed by a paediatrician had low birthweight (1619g donor, 1814g recipient, 1877g singleton) and had been born preterm (33 weeks twins, 31.2 weeks singleton) with attendant increased resuscitation, neonatal unit admission (mean 40 days) and instrumental delivery. Mean Griffiths scores were within the normal range of ability (91.2 donor vs 97.7 recipient and 101.6 singletons) with the only significant difference being in the locomotor subscale where donor (82.6) and recipient (85.3) were less than singletons: ‐99.1 (P<0.05). There was no cerebral palsy in the singleton survivors, but there were five cases in the twin group. All except one affected child (with quadriplegia) had mean Griffiths scores in the normal range. In the GP proforma group there was one case, in a twin, of cerebral palsy.

Conclusion
The overall cerebral palsy rate was 9%: 0% in the singleton survivors group and 13.3% in the twin survivors group. This pilot data highlights the need for careful long term follow up of children affected by twin‐to‐twin transfusion syndrome.
Clinical, provider and sociodemographic predictors of late initiation of antenatal care in England and Wales
Authors: Kupek Emil , Petrou Stavros , Vause Sarah , Maresh Michael
Published: December 2003

Objective
To identify factors that are predictive of late initiation of antenatal care in England and Wales.

Design
A multivariate binomial regression model was constructed to examine the association between clinical, provider and sociodemographic characteristics and late initiation of antenatal care.

Setting
Nine maternity units in Northern England and North Wales.

Population
A total of 20,771 women with a singleton pregnancy who delivered a liveborn or stillborn baby between 1 August 1994 and 31 July 1995. All analyses were based on the 17,765 (85.5%) women for whom information on gestational age at initial presentation for antenatal care and other variables incorporated into the regression model was retrievable from the case records

Results
Primiparous women of high obstetric risk were 13.4% more likely to initiate antenatal care after 10 weeks of gestation than a low risk reference group (adjusted OR 1.134, 95% CI 1.011, 1.272; P= 0.0312), and 34.3% more likely to initiate antenatal care after 18 weeks of gestation (adjusted OR 1.343, 95% CI 1.046, 1.724; P= 0.0208). This association between high obstetric risk status and late initiation of antenatal care was not replicated among multiparous women. When the effects of other independent variables on gestational age at booking were examined, the following characteristics were associated with failure to initiate antenatal care by 10 weeks of gestation (P≤ 0.05): maternal age at booking, smoking status, ethnicity, type of hospital at booking, the planned pattern of antenatal care and the planned place of delivery. Adopting a criterion of 18 weeks of gestation exacerbated the association between clinical and sociodemographic characteristics and late initiation of antenatal care, but appeared to dilute the association between provider characteristics and late initiation of antenatal care.

Conclusions
There is a pressing need for further research to identify the specific concerns of late bookers, to identify areas where new interventions might encourage the uptake of services and to gauge the likely impact of increased dissemination of information about the availability of antenatal care services.
Combined ultrasound and biochemical screening for Down's Syndrome in the first trimester: a Scottish multicentre study
Authors: Crossley Jennifer A. , Aitken David A. , Cameron Alan D. , McBride Elizabeth , Connor J. Michael
Published: December 2003

Objective
To evaluate the use of ultrasound measurements of fetal nuchal translucency (NT) obtained in a routine antenatal clinic setting in combination with appropriate biochemical markers as a first trimester screening test for Down's Syndrome.

Design
Multicentre observational study.

Setting
Fifteen Scottish maternity units.

Population
Pregnant women (n= 17,229) attending routine antenatal clinics at 10–14 weeks of gestation.

Methods
NT measurements were attempted in all women along with the measurement of maternal serum free beta human chorionic gonadotrophin (FβhCG) and pregnancy‐associated plasma protein‐A (PAPP‐A). All results were converted to multiples of the appropriate gestational median (MoM) and using a statistical model the risk of an affected pregnancy was derived. No results were given to participating women but all were offered routine second trimester biochemical screening. All cases of Down's Syndrome within the study group were ascertained and the detection rate for each marker was estimated.

Main outcome measures
Success rate of obtaining NT measurements and overall effectiveness of ultrasound and biochemical markers individually and in combination for the detection of Down's Syndrome pregnancies.

Results
NT measurements were obtained in 72.9% of women and blood samples in 98.4%. Forty‐five cases of Down's Syndrome were ascertained (2.6/1000). NT measurements were obtained in 37 cases (median NT 1.65 MoM), blood samples in 42 cases and both NT and blood in 34 cases. In combination with the a priori maternal age risk, observed detection rates at a 5% false positive rate were 20/37 (54%) for NT, 23/42 (55%) for FβhCG and PAPP‐A and 28/34 (82%) for a combination of NT, FβhCG and PAPP‐A using a cutoff risk of 1:250. The effect of failing to obtain NT measurements in all cases reduces the overall detection rate to 62% (i.e. 28/45) if the entire series of affected pregnancies within the study group is considered.

Conclusions
NT in combination with appropriate serum markers has the potential to detect over 80% of Down's Syndrome fetuses in early pregnancy. However, NT measurement is highly operator‐dependent. It requires training, external quality control and adequate time to allow accurate measurement, otherwise suboptimal performance will result.
Sterilisation during unplanned caesarean sections for women likely to have a completed family—should they be offered? Experience in a country with limited health resources
Authors: Verkuyl D.A.A.
Published: December 2003

Objective
To determine if it is proper to give a woman of higher parity who needs at short notice a caesarean section the option of a tubal ligation.

Design
Retrospective study.

Setting
Maternity unit of a tertiary hospital in Bulawayo, Zimbabwe.

Population
Women of higher parity who were delivered by an emergency caesarean section, by an elective caesarean section or vaginally and who had been asked or not asked whether they wanted a tubal ligation.

Methods
A postal questionnaire and visits to the participants.

Main outcome measures
Satisfaction with (in)fertility after having had, or not had, the option of a tubal ligation with the last delivery.

Results
In women who had an emergency caesarean section and who were successfully followed up, 301/418 (72.0%) had been offered a tubal ligation and 241/301 (80.1%) accepted. Of the 301 women, 269 (89.4%) were happy with the outcome. Thirty‐two women were unhappy (of whom 6 had tubal ligation, 24 had declined a sterilisation and in 2 cases the doctor forgot to do the sterilisation). Of the 117/418 women not offered a tubal ligation, 75/117 (64.1%) regretted not having had one. The relative risk of being unhappy with the consequences of not being offered tubal ligation compared with being given this option was 6.0 (95% CI 4.2–8.6, P < 0.001). Tubal ligations performed during emergency caesarean sections had no higher regret rate (2.5%) in this setting than those performed during elective caesarean sections (3.2%) and not much higher than postpartum sterilisations (0.5%). Women who did not have a tubal ligation during an emergency caesarean section regretted this (56.4%) significantly more often than women who did not have a tubal ligation with an elective caesarean section (34.6%) or after vaginal delivery (45.0%) (P < 0.01 and P < 0.02, respectively).

Conclusions
We found no evidence that the need to take an urgent decision resulted in more regret following tubal ligation. Women were far more likely to regret declining a tubal ligation (40%) than regret accepting one (2.5%). In this setting, some women are more likely to die of the next pregnancy than to regret an emergency tubal ligation.
The association between maternal HIV‐1 infection and pregnancy outcomes in Dar es Salaam, Tanzania
Authors: Coley Jenny L. , Msamanga Gernard I. , Fawzi Mary C. Smith , Kaaya Sylvia , Hertzmark Ellen , Kapiga Saidi , Spiegelman Donna , Hunter David , Fawzi Wafaie W.
Published: December 2003

Objective To examine the association between maternal HIV infection and pregnancy outcomes controlling for potential confounding factors among a cohort of HIV‐uninfected and HIV‐infected pregnant women in Dar es Salaam, Tanzania.

Design Prospective cohort study.

Methods A cohort of 1078 HIV‐infected and 502 HIV‐uninfected pregnant women between 12 and 27 weeks of gestation were enrolled and followed up until delivery. Multiple regression models were used to compare the risk of adverse pregnancy outcomes among HIV‐uninfected women with those among HIV‐infected women overall, and separately among asymptomatic or symptomatic HIV‐infected women.

Results No significant differences between HIV‐uninfected women and HIV‐infected women were observed in risks of fetal loss or low birthweight or in the weight, head circumference and gestational age of infants at birth. HIV‐infected women were more likely to have severe immature infants (<34 weeks) than HIV‐uninfected women (multivariate RR 1.54 [95% CI 0.90–2.48]; P=0.05). There was a significantly higher risk of low birthweight (RR 2.29, 95% CI 1.34–3.92; P=0.03) and prematurity (<37 weeks) (RR 1.93, 95% CI 1.35–2.77; P=0.0003) among symptomatic HIV‐infected women when compared with HIV‐uninfected women.

Conclusion HIV‐infected women, particularly those who are symptomatic, are at a higher risk of adverse pregnancy outcomes.
Morphological and morphometric age‐related changes of the upper thoracic aorta in Leontopithecus (Lesson, 1840) (Callitrichidae – Primates)
Authors: Pissinatti Alcides , Burity Carlos H. Freitas , Mandarim‐de‐Lacerda C.A.
Published: December 2003

Few morphologic aspects of Leontopithecus are listed in the literature, which does not provide sufficient knowledge of those simians. However, such results are important to evaluate the potential of those species as a model for studying comparative pathology. In this study, the material came from the collection of the Museu de Primatologia do Centro de Primatologia do Rio de Janeiro, fixed in 10% formalin pH 7.2. The samples were 33 individuals (five infant and five adult L. rosalia, L. chrysomelas, L. chrysopygus chrysopygus, and three adult L. chrysopygus caissara). The sections of the thoracic aorta were prepared for histological study and measurements were obtained. In the infant Leontopithecus, the aorta presents endothelial line and subendothelial space, the tunica media is not comparatively very thick. In the adults, the aorta showed enlarged tunica intima with consequent thick arterial wall, which increased with the aging process. The atheromatous plates were seen in the aortic wall of all adult L. chrysopygus chrysopygus, in two adult L. rosalia and only one adult L. chrysomelas. Differences in the aortic internal and external diameters were not significant in infants. In the adults, no significant difference was found among L. rosalia, L. chrysomelas and L. c. caissara, although the average of the aortic internal diameter in L. chrysomelas was larger than in L. c. caissara. In infant and adults L. c. chrysopygus, the thickness of the thoracic aorta is larger than in the other forms of Leontopithecus. These findings suggest a morphometric and morphologic aortic difference among the species of Leontopithecus, which could have biological significance that needs major investigation in the future.
Ultrasonographic findings of functioning renal allografts in the cynomolgus monkey (Macaca fascicularis)
Authors: Gaschen Lorrie , Audet Maxime , Menninger Klaus , Schuurman Henk‐Jan
Published: December 2003

Purpose: The purpose of this study was to describe the findings of serial ultrasound investigations of functioning and histologically normal renal allografts in the cynomolgus monkey. Methods: Ten cyclosporine (Neoral®) treated cynomolgus monkeys underwent renal allograft transplantation with bilateral nephrectomy, seven of which were examined serially with ultrasound. Ultrasound findings were compared to serum creatinine, and the results of histology from allograft biopsy on day 150 post‐transplantation.  Results: Allografts increased in volume up to one and a half to twice that of their original volume and appeared morphologically similar to native kidneys. Allograft ureters were dilated postoperatively but decreased in size with time. Other than in two cases of ureter complications, the resistive index (RI) was normal in functioning grafts.  Conclusions: Elevations in RI, as well as graft enlargement and increased cortical thickness, were related to graft pathology, but not necessarily to rejection histologically. The ultrasound findings of functioning grafts and of surgical complications after renal allograft transplantation in the cynomolgus monkey were similar to those in humans.