bluuebunny/crossref_metadata_2025 huggingface dataset:
Thrombopoietin serum levels do not correlate with thrombocytopenia in hepatic schistosomiasis
Authors: Souza MRa , Aguiar LAK , Goto JM , Carvente CT , Toledo CF , Borges DR. , Souza Mo^ônica R. A. , Aguiar Luciane A. K. , Goto Janaina M. , Carvente Cla´áudia T. , Toledo Carlos F. , Borges Durval R.
Published: July 2002

Abstract:  Background:  In severe forms of cirrhosis reduced liver synthesis of thrombopoietin (Tpo) can contribute to thrombocytopenia. In the hepatosplenic form of schistosomiasis, portal hypertension is the most evident clinical complication, although a deficiency of protein synthesis may be detected early. Our aim was to determine, for the first time in schistosomiasis, Tpo serum concentrations in patients with chronic forms of the disease.

Method:  Twenty‐four patients with the pure form of schistosomiasis were studied; 13 had the hepatosplenic form (HE, with portal hypertension) and 11 had the hepatointestinal form (HI, without portal hypertension). Patients were HBsAg, anti‐HBc and anti‐HCV negative, and reported alcohol ingestion below 160 g/week.

Results:  The Tpo serum concentration, determined in 10 healthy volunteers, varied from undetectable (< 15 pg/mL) to 489 pg/mL (median 208 pg/mL). The HE and HI groups differed (p = 0.004) in regard to the prothrombin index, thrombocytemia and γ‐glutamyltransferase but not in regard to Tpo (p = 0.622). No significant correlation was found between Tpo and the other parameters (p > 0.05).

Conclusions: The results suggest that Tpo serum concentration does not mirror and/or has no significant participation in the mechanisms responsible for the thrombocytopenia observed in schistosomiasis patients with splenomegaly and portal hypertension.
Viral dynamics in chronic hepatitis B patients during lamivudine therapy
Authors: Wolters LMM , Hansen BE , Niesters HGM , Zeuzem S , Schalm SW , RA de Man. , Wolters Lonieke M. M. , Hansen Bettina E. , Niesters Hubert G. M. , Zeuzem Stefan , Schalm Solko W. , De Man Robert A.
Published: July 2002

Abstract:  Rationale and aim: Recently, we described a first‐order decay model for the description of a decrease in viral load during treatment with lamivudine for a chronic hepatitis B virus infection (HBV). However, more frequent sampling of viral load during the first month of treatment shows a bi‐phasic viral decline. We therefore compared several mathematical models which are currently in use to describe the dynamics of various viruses and treatments.

Methods: HBV DNA positive chronic hepatitis B patients were treated with lamivudine 150–600 mg daily for four weeks. During the first two days, blood samples were drawn every 6 h, then daily during the first week and weekly during the following three weeks. HBV DNA was measured with the Digene Hybrid Capture II HBV DNA test and the sensitive Roche PCR assay, both calibrated on the Eurohep standard.

Results: Our HBV DNA data are most accurately described if we use the bi‐phasic model previously described by Neumann et al. while introducing all consecutive data of all patients simultaneously (mixed effects model). This results in an effectiveness of blocking of viral replication of 93%, a half‐life of free virus of 17 h and a half‐life of infected hepatocytes of 7 day in patients treated with 150 mg of lamivudine.

Conclusion: HBV dynamics during treatment with lamivudine can be explained by blocking of virion production with or without blocking of de novo infection. The bi‐phasic model as described by Neumann et al. in combination with frequent blood sampling provides the most accurate fit and can be used to compare new nucleoside analogue profiles to lamivudine therapy.
Protective effects of M40403, a selective superoxide dismutase mimetic, in myocardial ischaemia and reperfusion injury in vivo
Authors: Masini Emanuela , Cuzzocrea Salvatore , Mazzon Emanuela , Marzocca Cosimo , Mannaioni Pier Francesco , Salvemini Daniela
Published: July 2002

Myocardial injury caused by ischaemia and reperfusion comes from multiple pathogenic events, including endothelial damage, neutrophil extravasation into tissue, mast cell activation, and peroxidation of cell membrane lipids. These events are followed by myocardial cell alterations resulting eventually in cell necrosis. An enhanced formation of reactive oxygen species is widely accepted as a stimulus for tissue destruction and cardiac failure.

In this study, we have investigated the cardioprotective effects of M40403 in myocardial ischaemia‐reperfusion injury. M40403 is a low molecular weight, synthetic manganese containing superoxide dismutase mimetic (SODm) that selectively removes superoxide anion. Ischaemia was induced in rat hearts in vivo by ligating the left anterior descending coronary artery. Thirty minutes after the induction of ischaemia, the ligature was removed and reperfusion allowed to occur for at least 60 min. M40403 (0.1–1 mg kg−1) was given intravenously 15 min before ischaemia.

The results obtained in this study showed that M40403 significantly reduced the extent of myocardial damage, mast cell degranulation and the incidence of ventricular arrhythmias. Furthermore, M40403 significantly attenuated, in a dose‐dependent manner, neutrophil infiltration in the myocardium as well as the associated induction of lipid peroxidation. Calcium overload seen post‐reperfusion of the ischaemic myocardium was also reduced by M40403.

Immunohistochemical analysis for nitrotyrosine revealed a positive staining in cardiac tissue taken after reperfusion: this was attenuated by M40403. Moreover reperfused cardiac tissue sections showed positive staining for P‐selectin and for anti‐intercellular adhesion molecule (ICAM‐1) in the vascular endothelial cells. M40403 treatment markedly reduced the intensity and degree of P‐selectin and ICAM‐1 in these tissues. No staining for nitrotyrosine, P‐selectin or ICAM‐1 was found in cardiac tissue taken at the end of the ischaemic period.

Overall, M40403 treatment reduced the morphological signs of myocardial cell injury and significantly improved survival.

Taken together, these results clearly indicate that M40403 treatment exerts a protective effect against ischaemia‐reperfusion‐induced myocardial injury, supporting a key role for superoxide anion in reperfusion injuries. This suggests that synthetic enzymes of SOD such as M40403, offer a novel therapeutic approach for the treatment of ischaemic heart disease where superoxide anion plays a dominant role.

British Journal of Pharmacology (2002) 136, 905–917. doi:10.1038/sj.bjp.0704774
Mechanism of negative regulation of rat glutathione S-transferase A2 by the cytokine interleukin 6
Authors: VOSS Susan H. , WHALEN Richard , BOYER Thomas D.
Published: July 2002

A decrease in concentration of some liver proteins, including the detoxification enzyme glutathione S-transferase A2 (rGSTA2), occurs during the acute-phase response. Interleukin 6 (IL-6) with dexamethasone (DEX) decreases transcription of rGSTA2 in rat hepatocytes. The promoter region that mediates suppression of rGSTA2 was localized to 150bp. These 150bp were divided and used for electrophoretic mobility-shift assays. Induction of a protein that specifically bound to an oligonucleotide from this region required new protein synthesis and IL-6 with DEX in the culture media. The protein bound to part of the hepatocyte nuclear factor 1 (HNF1) site but was different from and did not displace HNF1. A core sequence, TGATT, was required for binding. The protein also bound to an HNF1 site in the albumin promoter. We hypothesize that IL-6 along with DEX induced a novel protein that decreased transcription of rGSTA2 and possibly albumin by interfering with the transactivating function of HNF1. The protein may be an important negative regulator of transcription during the acute-phase response.
Total direct chemical synthesis and biological activities of human group IIA secretory phospholipase A2
Authors: DONG Chang-Zhi , ROMIEU Anthony , MOUNIER Carine M. , HEYMANS Françoise , ROQUES Bernard P. , GODFROID Jean-Jacques
Published: July 2002

Human group IIA secretory phospholipase A2 (hGIIA sPLA2) is reported to be involved in inflammation, since its expression level is enhanced under various inflammatory conditions. In this work, we report the total chemical synthesis of this enzyme (124 amino acids) by solid-phase method. The identity of the protein, in denatured or folded (7 disulphide bonds) forms, was confirmed by electrospray MS. Synthetic sPLA2 possesses the same circular dichroism spectrum, enzymic activity in hydrolysing different phospholipid substrates, and inhibitory effect in thrombin formation from prothrombinase complex as the recombinant sPLA2. Furthermore, LY311727, a reported specific hGIIA sPLA2 inhibitor, is able to inhibit the synthetic and the recombinant enzymes with the same efficiency. This study demonstrates that chemically continuous solid phase synthesis is an alternative and less time-consuming approach to producing small, structurally folded and fully active proteins of up to 124 amino acids, such as hGIIA sPLA2. Moreover, this technique provides more flexibility in analogue synthesis to elucidate their physiological functions and pathological effects.
Multiple regions within the promoter of the murine Ifnar-2 gene confer basal and inducible expression
Authors: HARDY Matthew P. , HERTZOG Paul J. , OWCZAREK Catherine M.
Published: July 2002

The (murine) type I interferon (IFN) receptor, muIfnar-2, is expressed ubiquitously, and exists as both transmembrane and soluble forms. In the present study we show that the gene encoding muIfnar-2 spans approx. 33kb on mouse chromosome 16, and consists of nine exons and eight introns. The three mRNA splice variants resulting in one transmembrane (muIfnar-2c) and two soluble (muIfnar-2a/2a′) mRNA isoforms are generated by alternative RNA processing of the muIfnar-2 gene. Treatment of a range of murine cell lines with a combination of type I and II IFN showed that the muIfnar-2a and −2c mRNA isoforms were up-regulated independently of each other in L929 fibroblasts and hepa-1c1c7 hepatoma cells, but not in M1 myeloid leukaemia cells. Analysis of the 5′ flanking region of muIfnar-2 using promoter—luciferase reporter constructs defined three regulatory regions: a region proximal to exon 1, conferring high basal expression, a distal region conferring inducible expression, and a negative regulatory region between the two. These data represent the first promoter analysis of a type I IFN receptor and, taken together with our previous data demonstrating high expression levels and dual biological functions for muIfnar-2a protein, suggests that the regulation of muIfnar-2 isoform expression may be an important way of modulating type I IFN responses.
Biochemical identification of a neutral sphingomyelinase 1 (NSM1)-like enzyme as the major NSM activity in the DT40 B-cell line: absence of a role in the apoptotic response to endoplasmic reticulum stress
Authors: FENSOME Amanda C. , JOSEPHS Michelle , KATAN Matilda , RODRIGUES-LIMA Fernando
Published: July 2002

DT40 cells have approx. 10-fold higher Mg2+-dependent neutral sphingomyelinase (NSM) activity in comparison with other B-cell lines and contain very low acidic sphingomyelinase activity. Purification of this activity from DT40 cell membranes suggested the presence of one major NSM isoform. Although complete purification of this isoform could not be achieved, partially purified fractions were examined further with regard to the known characteristics of previously partially purified NSMs and the two cloned enzymes exhibiting in vitro NSM activity (NSM1 and NSM2). For a direct comparative study, highly purified brain preparations, purified NSM1 protein and Bacillus cereus enzyme were used. Analysis of the enzymic properties of the partially purified DT40 NSM, such as cation dependence, substrate specificity, redox regulation and stimulation by phosphatidylserine, together with the localization of this enzyme to the endoplasmic reticulum (ER), suggested that this NSM from DT40 cells corresponds to NSM1. Further studies aimed to correlate presence of the high levels of this NSM1-like activity in DT40 cells with the ability of these cells to accumulate ceramide and undergo apoptosis. When DT40 cells were stimulated to apoptose by a variety of agents, including the ER stress, an increase in endogenous ceramide levels was observed. However, these responses were not enhanced compared with another B-cell line (Nalm-6), characterized by low sphingomyelinase activity. In addition, DT40 cells were not more susceptible to ceramide accumulation and apoptosis when exposed to the ER stress compared with other apoptotic agents. Inhibition of de novo synthesis of ceramide partially inhibited its accumulation, indicating that the ceramide production in DT40 cells could be complex and, under some conditions, could involve both sphingomyelin hydrolysis and ceramide synthesis.
d-Lactate transport and metabolism in rat liver mitochondria
Authors: de BARI Lidia , ATLANTE Anna , GUARAGNELLA Nicoletta , PRINCIPATO Giovanni , PASSARELLA Salvatore
Published: July 2002

In the present study we investigated whether isolated rat liver mitochondria can take up and metabolize d-lactate. We found the following: (1) externally added d-lactate causes oxygen uptake by mitochondria [P/O ratio (the ratio of mol of ATP synthesized to mol of oxygen atoms reduced to water during oxidative phosphorylation) = 2] and membrane potential (Δψ) generation in processes that are rotenone-insensitive, but inhibited by antimycin A and cyanide, and proton release from coupled mitochondria inhibited by α-cyanocinnamate, but not by phenylsuccinate; (2) the activity of the putative flavoprotein (d-lactate dehydrogenase) was detected in inside-out submitochondrial particles, but not in mitochondria and mitoplasts, as it is localized in the matrix phase of the mitochondrial inner membrane; (3) three novel separate translocators exist to mediate d-lactate traffic across the mitochondrial inner membrane: the d-lactate/H+ symporter, which was investigated by measuring fluorimetrically the rate of endogenous flavin reduction, the d-lactate/oxoacid antiporter (which mediates both the d-lactate/pyruvate and d-lactate/oxaloacetate exchanges) and d-lactate/malate antiporter studied by monitoring photometrically the appearance of the d-lactate counteranions outside mitochondria. The d-lactate translocators, in the light of their different inhibition profiles separate from the monocarboxylate carrier, were found to differ from each other in the Vmax values and in the inhibition and pH profiles and were shown to regulate mitochondrial d-lactate metabolism in vitro. The d-lactate translocators and the d-lactate dehydrogenase could account for the removal of the toxic methylglyoxal from cytosol, as well as for d-lactate-dependent gluconeogenesis.
Homo- and hetero-oligomeric interactions between G-protein-coupled receptors in living cells monitored by two variants of bioluminescence resonance energy transfer (BRET): hetero-oligomers between receptor subtypes form more efficiently than between less closely related sequences
Authors: RAMSAY Douglas , KELLETT Elaine , McVEY Mary , REES Stephen , MILLIGAN Graeme
Published: July 2002

Homo- and hetero-oligomerization of G-protein-coupled receptors (GPCRs) were examined in HEK-293 cells using two variants of bioluminescence resonance energy transfer (BRET). BRET2 (a variant of BRET) offers greatly improved separation of the emission spectra of the donor and acceptor moieties compared with traditional BRET. Previously recorded homo-oligomerization of the human δ-opioid receptor was confirmed using BRET2. Homo-oligomerization of the κ-opioid receptor was observed using both BRET techniques. Both homo- and hetero-oligomers, containing both δ- and κ-opioid receptors, were unaffected by the presence of receptor ligands. BRET detection of opioid receptor homo- and hetero-oligomers required expression of 50000–100000 copies of the receptor energy acceptor construct per cell. The effectiveness of δ—κ-opioid receptor hetero-oligomer formation was as great as for homomeric interactions. The capacity of the two opioid receptors to form oligomeric complexes with the β2-adrenoceptor was also assessed. Although such interactions were detected, at least 250000 copies per cell of the energy acceptor were required. Requirement for high levels of receptor expression was equally pronounced in attempts to measure hetero-oligomer formation between the κ-opioid receptor and the thyrotropin-releasing hormone receptor-1. These studies indicate that constitutively formed homo- and hetero-oligomers of opioid receptor subtypes can be detected in living cells containing less than 100000 copies of the receptors. However, although hetero-oligomeric interactions between certain less closely related GPCRs can be detected, they appear to be of lower affinity than homo- or hetero-oligomers containing closely related sequences. Interactions recorded between certain GPCR family members in heterologous expression systems are likely to be artefacts of extreme levels of overexpression.
Embryonic extracts derived from the nematode Caenorhabditis elegans remove uracil from DNA by the sequential action of uracil-DNA glycosylase and AP (apurinic/apyrimidinic) endonuclease
Authors: SHATILLA Andrea , RAMOTAR Dindial
Published: July 2002

DNA bases continuously undergo modifications in response to endogenous reactions such as oxidation, alkylation or deamination. The modified bases are primarily removed by DNA glycosylases, which cleave the N-glycosylic bond linking the base to the sugar, to generate an apurinic/apyrimidinic (AP) site, and this latter lesion is highly mutagenic. Previously, no study has demonstrated the processing of these lesions in the nematode Caenorhabditis elegans. Herein, we report the existence of uracil-DNA glycosylase and AP endonuclease activities in extracts derived from embryos of C. elegans. These enzyme activities were monitored using a defined 5′-end 32P-labelled 42-bp synthetic oligonucleotide substrate bearing a single uracil residue opposite guanine at position 21. The embryonic extract rapidly cleaved the substrate in a time-dependent manner to produce a 20-mer product. The extract did not excise adenine or thymine opposite guanine, although uracil opposite either adenine or thymine was processed. Addition of the highly specific inhibitor of uracil-DNA glycosylase produced by Bacillus subtilis to the extract prevented the formation of the 20-mer product, indicating that removal of uracil is catalysed by uracil-DNA glycosylase. The data suggest that the 20-mer product was generated by a sequential reaction, i.e., removal of the uracil base followed by 5′-cleavage of the AP site. Further analysis revealed that product formation was dependent upon the presence of Mg2+, suggesting that cleavage of the AP site, following uracil excision, is carried out by a Mg2+-dependent AP endonuclease. It would appear that these activities correspond to the first two steps of a putative base-excision-repair pathway in C. elegans.
A 13C-NMR study of the inhibition of papain by a dipeptide-glyoxal inhibitor
Authors: LOWTHER Jonathan , DJURDJEVIC-PAHL Aleksandra , HEWAGE Chandralal , MALTHOUSE J. Paul G.
Published: July 2002

Z-Phe-Ala-glyoxal (where Z is benzyloxycarbonyl) has been synthesized and shown to be a competitive inhibitor of papain with a Ki = 3.30±0.25nM. 13C-NMR has been used to show that in aqueous media, Z-Phe-[2-13C]Ala-glyoxal gives signals at 207.7p.p.m. and 96.3p.p.m. showing that both the α-keto carbon and its hydrate are present. When this inhibitor is bound to papain a single signal at 209.7p.p.m. is observed due to the 13C-enriched carbon. This demonstrates that the glyoxal α-keto carbon is not hydrated when it is bound to papain and that it does not form a thiohemiketal with the thiol group of Cys-25. Z-Phe-[1-13C]Ala-glyoxal has also been synthesized and its aldehyde carbon is fully hydrated in aqueous solution giving signals at 88.7p.p.m. and 90.2p.p.m. when the α-keto carbon and its hydrate are present respectively. When this inhibitor is bound to papain a single signal at 71.04p.p.m. was observed due to the 13C-enriched carbon showing that the 13C-enriched aldehyde carbon forms a thiohemiacetal with Cys-25.
A novel, kinetically stable, catalytically active, all-ferric, nitrite-bound complex of Paracoccus pantotrophus cytochrome cd1
Authors: ALLEN James W.A. , HIGHAM Christopher W. , ZAJICEK Richard S. , WATMOUGH Nicholas J. , FERGUSON Stuart J.
Published: July 2002

The oxidized form of Paracoccus pantotrophus cytochrome cd1 nitrite reductase, as isolated, has bis-histidinyl co-ordination of the c haem and His/Tyr co-ordination of the d1 haem. On reduction, the haem co-ordinations change to His/Met and His/vacant respectively. If the latter form of the enzyme is reoxidized, a conformer is generated in which the ferric c haem is His/Met co-ordinated; this can revert to the ‘as isolated’ state of the enzyme over approx. 20min at room temperature. However, addition of nitrite to the enzyme after a cycle of reduction and reoxidation produces a kinetically stable, all-ferric complex with nitrite bound to the d1 haem and His/Met co-ordination of the c haem. This complex is catalytically active with the physiological electron donor protein pseudoazurin. The effective dissociation constant for nitrite is 2mM. Evidence is presented that d1 haem is optimized to bind nitrite, as opposed to other anions that are commonly good ligands to ferric haem. The all-ferric nitrite bound state of the enzyme could not be generated stoichiometrically by mixing nitrite with the ‘as isolated’ conformer of cytochrome cd1 without redox cycling.
The quality of alcohol treatment research: an examination of influential controlled trials and development of a quality rating system
Authors: Moncrieff Joanna , Drummond D. Colin
Published: July 2002

Background. The importance of evidence‐based practice has stimulated interest in the methodology of clinical trials. Various weaknesses of evaluation research in the alcohol field have been indicated previously. This study set out to develop a comprehensive system for the assessment of the methodological quality of outcome research for treatment of alcohol misuse and to apply the system to well‐known trials in the area. Methodology. A sample of the most highly cited controlled trials of interventions for alcohol misuse was selected using the Science Citation Index. Thirty methodological criteria were formulated and a scoring system devised. Two raters applied this system to the sample of trials. Reliability testing was performed and used to refine the criteria. Results. Inter‐rater reliability of the overall quality score was initially 0.85 and 0.92 after review and re‐rating. Internal consistency was also high (0.87). Quality score correlated with year of publication. Certain areas of methodology were poorly addressed in the sample, including specification of main outcomes, documentation of recruitment and selection procedures, testing of blinding, analysis of withdrawals and reporting of results. Discussion. The methodology of this sample of trials was frequently deficient in ways which might bias results or compromise generalizability. It is recommended that the system of quality assessment described here is used to evaluate existing research and to inform the design of future studies.
Exploring the nature of the relationship between child sexual abuse and substance use among women
Authors: Jarvis Tracey J. , Copeland Jan , Walton Layton
Published: July 2002

Aims. This study investigated whether child sexual abuse (CSA) was associated with earlier substance use and greater severity of substance dependence and what aspects of CSA might predict substance abuse. Design. The study compared (a) drug and alcohol treatment clients with and without a history of CSA and (b) CSA survivors outside drug and alcohol treatment who did or did not have current substance abuse. Settings. Semi‐structured interviews took place at participants' homes, treatment agencies or the research centre. Participants. Volunteer participants included 100 women recruited from drug and alcohol treatment programmes and 80 CSA survivors recruited through CSA counselling services and media advertising. Measurements. The results focus on data from the Opiate Treatment Index, Severity of Alcohol Dependence Questionnaire, Substance Dependence Scale, Self‐Esteem Inventory and self‐reported histories of CSA. Findings. There were no differences between CSA survivors and other drug and alcohol treatment clients in their severity of dependence. Women with a history of CSA more frequently identified stimulants as their main problem drug and reported an earlier age of first intoxication and earlier use of inhalants. Among CSA survivors outside drug and alcohol treatment, women with current substance abuse had typically been abused during adolescence by someone outside the family, whereas those without current substance abuse were typically abused by family members before adolescence. Conclusions. The results suggest that adolescence is a crucial time for the influence of CSA experiences on substance abuse.
Society for Research on Nicotine and Tobacco
Authors: Heishman Stephen J. , Henningfield Jack E. , Kendler Kenneth S. , Houezec Jacques Le , Malin David H. , Pomerleau Ovide F. , Schneider Nina G.
Published: July 2002

The goal of the third annual scientific conference of the Society for Research on Nicotine and Tobacco was to provide a forum for the exchange of information across the spectrum of nicotine and tobacco research. Five symposia covered the following topics: animal and human models of nicotine dependence, use of nicotine as a therapeutic agent in disorders associated with ageing and psychopathology, public health strategies to reduce morbidity and mortality caused by smoking by reducing exposure to tobacco smoke, new pharmacological treatments and treatment combinations that are being tested for smoking cessation and the integration of behavioral and molecular genetic approaches to explain nicotine dependence. The genetic epidemiology of smoking initiation and nicotine dependence was the topic of an invited address. The findings presented at the conference clearly demonstrated the wide range of nicotine and tobacco research programs.
Energy, macro‐ and micronutrient intake of 5‐year‐old urban black South African children in 1984 and 1995
Authors: MacKeown  , Cleaton‐Jones  , Edwards  , Turgeon‐O’Brien
Published: July 2002

Food habits change over time. This paper reports results of nutritional studies among 5‐year‐old urban black children in 1984 and 1995 in the Johannesburg/Soweto area. The objective was to compare energy, macro‐ and micronutrient intake of 5‐year‐old urban black South African children. Dietary intake was assessed by detailed dietary histories in 1984 and food frequency questionnaires in 1995, conducted by trained interviewers. The intake of energy, macro‐ and most micronutrients was higher in 1995 than in 1984, except for vitamin A, ascorbic acid, copper and iron. Fat intake increased from 52 g/day in 1984 to 95 g/day in 1995. Only biotin and vitamin D fell below 67% of the recommended dietary allowances (RDA) for 4‐ to 6‐year‐olds, but mean intakes concealed the high percentage of children that had intakes below the RDA in 1984 and 1995. Urban black 5‐year‐old South African children consumed a low‐fat (30% of total energy), high‐carbohydrate (61% of total energy) diet in 1984, but a typical westernised diet by 1995 (fat 41% and carbohydrate 52% of total energy). With these changes, current reliable nutrition information is needed to assess the existing and future health needs of all South Africans.
Expression of endogenous transforming growth factor‐β and its type I and type II receptors in rat burn wounds
Authors: Wei Duo , Ge Shengde , Chen Yulin , Dai Fangping , Su Bo
Published: July 2002

Transforming growth factor‐β is a potent regulator of numerous processes in wound healing. These biological activities require the interaction of the growth factor with two classes of cell surface receptors, namely the type I and type II receptors. To understand the role of transforming growth factor‐β in burn wound healing, we undertook a study to localize this growth factor and its cell surface receptors within dermal burn wounds. Partial‐thickness burn injuries were made on the backs of Wistar rats. At 1, 3, 5, 7, 10, 15, and 20 days after burning, samples of wounded and control skin were removed for the isolation of total RNA and immunohistochemistry. Thermal injury induced the expression of mRNA for transforming growth factor‐β and both type I and type II receptors. The expression of transforming growth factor‐β peaked 5 to 7 days after injury, then gradually declined. Of note, the expression of the transforming growth factor‐β receptors returned to normal before the expression of the growth factor. Immunohistochemical analysis showed that transforming growth factor‐β protein levels paralleled mRNA expression, and the protein was primarily localized to the migrating epidermal cells and dermal fibroblasts. The differences between the expression of transforming growth factor‐β and its receptors in the later stages of healing thermal injuries suggests the presence of a well‐controlled mechanism to limit the effect of the growth factor on repair cells.
Epidermal lipid metabolism of cultured skin substitutes during healing of full‐thickness wounds in athymic mice
Authors: Vičanová Jana , Ponec Maria , Weerheim Arij , Swope Viki , Westbrook Melissa , Harriger Dana , Boyce Steven
Published: July 2002

Cultured epidermal keratinocytes provide an abundant supply of biologic material for wound treatment. Because restoration of barrier function is a definitive criterion for efficacy of wound closure and depends on the lipids present in the epidermis, we analyzed lipid composition of the epidermis in cultured skin substitutes in vitro and after grafting to athymic mice. The cultured skin substitutes were prepared from human keratinocytes and fibroblasts attached to collagen‐glycosaminoglycan substrates. After 14 days of incubation, cultured skin substitutes were grafted orthotopically onto full‐thickness wounds in athymic mice. Samples for lipid analysis were collected after 14 and 34 days of in vitro incubation, and 3 weeks and 4 months after grafting. Both in vitro samples show disproportions in epidermal lipid profile as compared with the native human epidermis, i.e., a low amount of phospholipids (indicating imbalance in proliferation and differentiation); a large excess of triglycerides (storage lipids); and low levels of free fatty acids, glucosphingolipids, cholesterol sulfate, and ceramides—suggesting abnormal composition of stratum corneum barrier lipids. Fatty acid analysis of cultured skin substitutes in vitro revealed insufficient uptake of linoleic acid, which resulted in increased synthesis of and substitution with monounsaturated fatty acids, mainly oleic acid. These abnormalities were partially corrected by 3 weeks after grafting; and 4 months after grafting, all epidermal lipids, with some minor exceptions, were synthesized in proportions very similar to human epidermis. Results of this study show that grafting of cultured skin substitutes to a physiologic host permits the recovery of lipid in proportion to that required for barrier formation in normal human epidermis.
Expression of Wnt genes in early wound healing
Authors: Labus Marie B. , Stirk Christina M. , Thompson W. Douglas , Melvin William T.
Published: July 2002

The Wnt family of developmental genes has previously been shown to be involved in proliferation, differentiation, and cell to cell signaling during embryogenesis. In addition, several Wnt genes have been shown to be expressed during carcinogenesis. We have investigated these genes during the wound‐healing process. Wnt‐4 gene expression is found in mouse wounds from 2 hours to 30 hours postwounding. The expression of Wnt‐4 is also stimulated by direct trauma to murine fibroblasts in culture, and the expression is greatly enhanced by the addition of a short plasmin digest of fibrin. Therefore the regulation of Wnt‐4, appears to be complex, with expression being stimulated both by direct trauma and by the influence of clotting and fibrinolysis products. We propose that the expression of Wnt‐4 in the early wound, in response to the provisional fibrin matrix, regulates cell movement and proliferation in the creation of new tissue by mechanisms related to those of embryogenesis.
Effect of a collagen matrix containing epidermal growth factor on wound contraction
Authors: Inoue Masayuki , Ono Ichiro , Tateshita Tohru , Kuroyanagi Yoshimitsu , Shioya Nobuyuki
Published: July 2002

Excessive wound contraction is known to lead to pathological wound contracture. Using a rabbit model, we applied a bovine type I collagen matrix sponge as a dermal substitute and human epidermal growth factor to full‐thickness excisional wounds. Wound contraction was assessed 14 and 28 days after wounding. It was found that both collagen matrix and epidermal growth factor significantly inhibited wound contraction (p < 0.001) in all wounds treated with collagen matrix alone or treated with 0.1 and 1 µg of epidermal growth factor 28 days after wounding. Interestingly, the combination of collagen matrix with epidermal growth factor strongly inhibited wound contraction over matrix alone (p < 0.01 on day 28). Histological analyses showed a regular horizontal arrangement of collagen fibers in the dermis under wounds treated with these substances but not under untreated wounds. Furthermore, using a fibroblast‐populated collagen gel, the direct inhibitory effect of epidermal growth factor on gel contraction by fibroblasts was also observed. Collagen gels without stimulation contracted to 29.5 ± 0.6% of their original size, as determined 6 days after culturing. At 3 days or more, epidermal growth factor inhibited collagen gel contraction by fibroblasts (after 6 days: 34.2 ± 1.8%, p > 0.05; 36.5 ± 2.8%, p < 0.05; and 39.8 ± 2.1%, p < 0.001 at 1, 10, and 100 ng/ml of epidermal growth factor, respectively). In conclusion, collagen matrix and epidermal growth factor, particularly in combination, may be useful in the prevention of wound contracture.
Dermal regeneration in full‐thickness wounds in Yucatan miniature pigs using a biodegradable copolymer
Authors: Van Dorp Annette G.M. , Verhoeven Mary C.H. , Koerten Henk K. , Van Der Nat‐Van Der Meij Tineke H. , Van Blitterswijk Clemens A. , Ponec Maria
Published: July 2002

The aim of this study was to assess the performance of a biodegradable dermal substrate in deep dermal skin defects. The substrate consisted of a synthetic biodegradable matrix called Polyactive, which is an elastomeric poly (ether)/poly (ester) block copolymer. This matrix was manufactured either as a porous substrate, with gradually changing pore size (BISKIN‐M), or as a bilayer consisting of a porous underlayer with a fully dense surface layer (BISKIN). Cell‐free matrices and matrices seeded with autologous or allogeneic porcine fibroblasts were applied to full‐thickness skin wounds in Yucatan miniature pigs. Biopsies were taken at different time intervals up to 24‐months post‐transplantation. Although all BISKIN substrates showed little or no adherence to the wound bed, the adherence of the BISKIN‐M substrates to the underlying wound was achieved within minutes after application. Therefore, only BISKIN‐M Polyactive substrates were further evaluated. Wound contraction was inhibited by both cell‐free and fibroblast‐populated substrates. All substrates showed extensive neovascular and fibrous tissue ingrowth within 2‐weeks post‐transplantation. Furthermore, during this time period, matrix degradation was observed, starting with the fragmentation of the polymers into particles, which were phagocytized by macrophages. These processes occurred actively up to 3 months and ceased thereafter. Cell‐free substrates degraded faster, and also, the collagen deposition was lower as compared with cell‐seeded substrates. The tissue surrounding the remnants of the Polyactive substrates after 24‐months post‐transplantation consisted of a mature connective tissue. The newly formed collagen had the same distribution pattern as observed in normal native dermis. We conclude therefore that treatment of full‐thickness skin defects with fibroblast‐populated BISKIN‐M Polyactive substrates leads to satisfactory dermal regeneration.
Reduction of Yersinia enterocolitica load in deliberately inoculated blood: the effects of blood prestorage temperature and WBC filtration
Authors: Siblini Loubna , Lafeuillade Bruno , Ros Alain , Le Petit Jean‐Claude , Pozzetto Bruno
Published: July 2002

BACKGROUND: Yersinia enterocolitica is known to cause severe infections in patients who receive transfusions.

STUDY DESIGN AND METHODS: The aim of the study was to define the best strategy for reducing the bacterial load in blood that was deliberately contaminated with Y. enterocolitica by combining prestorage temperature and WBC filtration with conditions of blood processing close to those applied in blood banks.

RESULTS: The effects of three prestorage temperatures (4°C, 20°C, 37°C) were evaluated at various times after infection. The best reduction of bacterial load was achieved after 3 hours at 20°C. In further experiments, conducted according to the former specifications, filtration of whole blood from eight and six donors with an inoculum of 100 and 500 to 1000 CFUs per mL, respectively, resulted in a total inhibition of bacterial growth up to 42 days after infection. After fractionation of blood components, in contrast to plasma and RBCs, filtration was shown to reduce dramatically the bacterial growth in buffy coats, demonstrating that the antibacterial effect of filtration was supported by the removal of infected WBCs from blood samples.

CONCLUSION: These results provide support for the systematic use of blood filtration in the preparation of blood components to prevent Y. enterocolitica infection of patients receiving transfusions.
The transfusion trigger and number of units transfused in patients with HIV: associations with disease stage and functional status
Authors: Kennedy Melanie S. , Kalish Leslie A. , Mohandas Kala , Gernsheimer Terry , Townsend‐McCall Dee , For The Viral Activation Transfusion Study Group
Published: July 2002

BACKGROUND: The influence of quality of life (QOL), physical functioning, and HIV disease stage on the transfusion trigger and the number of units transfused was investigated.

STUDY DESIGN AND METHODS: The Viral Activation Transfusion Study, a randomized, double‐blind study at 11 participating sites, enrolled HIV‐positive patients with anemia who required RBC transfusion; 428 patients were included in the analysis of the first transfusion. The QOL scores, Perceived Health Index, Karnofsky score, CD4+ cell count, HIV viral load, and site were analyzed for relationships with the Hb level and the number of units transfused.

RESULTS: The transfusion trigger was lower in patients with higher levels of Karnofsky score, Perceived Health Index, CD4+ cell count, and a number of QOL scales. Both the Hb trigger and the number of units transfused had a significant site variation. Males were transfused at a significantly lower Hb level than females. In multivariate analysis, the CD4+ cell count remained significant, but the Karnofsky score or the Perceived Health Index did not. The number of RBC units transfused was associated with the Hb level, CD4+ cell counts, and Karnofsky scores in unadjusted analysis but with only Hb in adjusted analysis.

CONCLUSIONS: In this group of HIV+ patients, lower CD4+ cell counts prompted transfusion at higher Hb levels. However, after controlling for the Hb level, the number of units transfused was associated with only the Hb level. The HIV stage appears to influence the decision to transfuse at a particular Hb level but not to influence the number of RBC units transfused. The functional status does not appear to influence the decision to transfuse.
The Efficacy of an Educational Treatment Program for Patients with Epilepsy (MOSES): Results of a Controlled, Randomized Study
Authors: May Theodor W. , Pfäfflin Margarete
Published: July 2002

Summary:  Purpose: To evaluate the efficacy of the educational program MOSES (Modular Service Package Epilepsy). It was developed to improve patients' knowledge and understanding about their epilepsy, its treatment, and psychosocial consequences. The program intends to improve patients' coping with the disease, to strengthen self‐esteem, and to support patients to become experts in managing their epilepsy.

Methods: A controlled, randomized study design was used to examine the efficacy of MOSES. Patients from 22 epilepsy centers in Germany, Austria, and Switzerland were randomly allocated to either MOSES group (treatment group) or waiting‐list group (control group). The 242 patients were aged from 16 to 80 years. The MOSES group (n = 113) completed the questionnaires immediately before the educational course (T1) and 6 months later (T2), and the control group (n = 129), 6 months before (T1) and immediately before (T2) the course. The questionnaires included generic instruments (SF‐36, Rosenberg self‐esteem Scale, von Zerssen Depression Scale), and epilepsy‐specific scales (Restrictions in Daily Life, Epilepsy‐Related Fears, Coping with Epilepsy and Adaptation). Depression was used as a moderator variable. Seizure frequency and satisfaction with therapy also were assessed. Multivariate analysis of variance (MANOVA) with repeated measurements and univariate analyses of variance were performed.

Results: The MANOVA showed that participants of the educational program improved significantly. Univariate analyses revealed improvements in knowledge (p < 0.001) and coping with epilepsy (p = 0.004), whereas important effects of MOSES on other epilepsy‐specific measures and on generic questionnaires (SF‐36, self‐esteem) were not found. Participants of the MOSES program also improved in seizure outcome (p = 0.041) and became more satisfied with the therapy [better tolerability of antiepileptic drug (AED) therapy, fewer side effects; p = 0.014]. In addition, participants expressed being highly satisfied with the program.

Conclusions: The study clearly indicates the need for patient education. Even patients with a long history of epilepsy and with additional handicaps or diseases benefitted from the MOSES program.
Electronic structure of solid nitromethane: Effects of high pressure and molecular vacancies
Authors: Margetis Dionisios , Kaxiras Efthimios , Elstner Marcus , Frauenheim Th. , Manaa M. Riad
Published: July 2002

The combined effect of pressure and molecular vacancies on the atomic structure and electronic properties of solid nitromethane, a prototypical energetic material, is studied at zero temperature. The self-consistent charge density-functional tight-binding method is applied in order to investigate changes induced in the band gap of this system by uniform and uniaxial strain of up to 70%, corresponding to static pressure in the range of up to 200 GPa. The effects of molecular vacancies with densities ranging from 3% to 25% have also been considered. A surprising finding is that uniaxial compression of about 25–40 GPa along the b lattice vector causes the C–H bond to be highly stretched and leads to proton dissociation. This event also occurs under isotropic compression but at much higher pressure, being indicative of a detonation chemistry which is preferential to the pressure anisotropy. We also find that the band gap, although evidently dependent on the applied strain, crystal anisotropy and vacancy density, is not reduced considerably for electronic excitations to be dominant, in agreement with other recent first-principles studies.
Raman scattering as a probe of morphology in conjugated polymer thin films
Authors: Liem H. , Etchegoin P. , Whitehead K. S. , Bradley D. D. C.
Published: July 2002

Polarized confocal Raman mapping is used to characterize the degree of molecular alignment in spin coated conjugated polymer thin films. To this end, the polarization selection rules of a specific Raman active mode are employed to infer indirectly the local molecular alignment. The film can be monitored and characterized with a diffraction limited spatial resolution fixed by the microscope optics. In addition, we demonstrate examples of characterization of molecular alignment in highly oriented samples by monitoring the angular dependence of the polarized Raman signal. Finally, we show the use of temperature dependent Raman scattering to monitor thermal phase transitions in bulk conjugated polymer samples. These procedures can be used as in situ characterization methods in a wide variety of experimental situations and offer a sensitive probe of processing protocols used in the fabrication of polymer optoelectronic devices.
Leakage current conduction of pulsed excimer laser ablated BaBi2Nb2O9 thin films
Authors: Laha Apurba , Krupanidhi S. B.
Published: July 2002

The leakage current behavior of the BaBi2Nb2O9 (BBN) thin films was investigated over a wide range of temperatures. The current density, calculated from current–voltage (I–V) characteristics at room temperature, was 4.02×10−9 A/cm2 at an electric field of 3×105 V/m. The I–V characteristics of the films showed ohmic behavior for electric field strength lower than 1 MV/m. Nonlinearity in the current density–voltage (J–V) behavior was observed at an electric field above 1 MV/m. Different conduction mechanisms were brought into picture to explain the I–V characteristics of BBN thin films. The J–V behavior of BBN thin films was found to follow the Lampert’s theory of space charge limited conduction in an insulator with traps. Three different regions, i.e., ohmic, trap filled limited, Child’s law were explicitly observed in J–V characteristics. The activation energies in the ohmic region calculated from the Arrhenius plot were 0.46, 0.48, and 0.51 eV, respectively. These energies were attributed to the shallow traps, distributed near the conduction band edge in the forbidden gap of the materials.
Dynamic wall modeling for large-eddy simulation of complex turbulent flows
Authors: Wang Meng , Moin Parviz
Published: July 2002

The efficacy of large-eddy simulation (LES) with wall modeling for complex turbulent flows is assessed by considering turbulent boundary-layer flows past an asymmetric trailing-edge. Wall models based on turbulent boundary-layer equations and their simpler variants are employed to compute the instantaneous wall shear stress, which is used as approximate boundary conditions for the LES. It is demonstrated that, as first noted by Cabot and Moin [Flow Turb. Combust. 63, 269 (2000)], when a Reynolds-averaged Navier–Stokes type eddy viscosity is used in the wall-layer equations with nonlinear convective terms, its value must be reduced to account for only the unresolved part of the Reynolds stress. A dynamically adjusted mixing-length eddy viscosity is used in the turbulent boundary-layer equation model, which is shown to be considerably more accurate than the simpler wall models based on the instantaneous log law. This method predicts low-order velocity statistics in good agreement with those from the full LES with resolved wall-layers, at a small fraction of the original computational cost. In particular, the unsteady separation near the trailing-edge is captured correctly, and the prediction of surface pressure fluctuations also shows promise.