bluuebunny/crossref_metadata_2025 huggingface dataset:
Serum cystatin C advantageous compared with serum creatinine in the detection of mild but not severe diabetic nephropathy
Authors: Christensson A. G. , Grubb A. O. , Nilsson J.‐Å. , Norrgren K. , Sterner G. , Sundkvist G.
Published: November 2004

Objective.  To determine whether serum cystatin C is more accurate than serum creatinine in the detection of diabetic nephropathy, also after adjustment for age.

Methods.  Forty‐one patients with type 1 and 82 patients with type 2 diabetes were evaluated with serum creatinine, serum cystatin C, and 51Cr‐EDTA clearance (reference method). Cystatin C was measured by a particle‐enhanced turbidimetric method and creatinine by an enzymatic method. Statistical estimations were performed both without and with age adjustment created by z‐scores for 51Cr‐EDTA clearance, creatinine, and cystatin C. The cut‐off levels for glomerular filtration rate (GFR) (51Cr‐EDTA clearance) were 60 and 80 mL min−1 1.73 m−2, respectively, in absolute values and 80, 90 and 95% CIs, respectively, in age‐adjusted values (z‐scores).

Results.  Estimations without age adjustment showed significantly (P = 0.0132) closer correlation for cystatin C (r = 0.817) versus 51Cr‐EDTA clearance as compared with creatinine (r = 0.678). However, when using age‐adjusted values, the correlation for cystatin C and creatinine, respectively, versus 51Cr‐EDTA clearance did not differ. When comparing the diagnostic utilities for serum cystatin C versus serum creatinine in manifest renal impairment (GFR < 60 mL min−1 1.73 m−2 or z‐scores <−1.28 SD), there were no significant differences between the two markers whether age adjusted or not. However, for diagnosing mild nephropathy (GFR < 80 mL min−1 1.73 m−2 or z‐score −0.84 SD), serum cystatin C is significantly more useful.

Conclusions.  Serum cystatin C performed better compared with serum creatinine even when measured enzymatically, to detect mild diabetic nephropathy. However, serum creatinine was as efficient as serum cystatin C to detect advanced diabetic nephropathy.
Elevated plasma homocysteine: cause or consequence of myocardial infarction?
Authors: Hultdin J. , Thøgersen A. M. , Jansson J.‐H. , Nilsson T. K. , Weinehall L. , Hallmans G.
Published: November 2004

Objectives.  To determine whether a first myocardial infarction leads to increased plasma homocysteine concentrations and whether the association between homocysteine and myocardial infarction was greater at follow‐up compared with baseline.

Design.  A population‐based, prospective, nested case‐referent study.

Setting.  Screening took place at the nearest health survey centre in northern Sweden.

Subjects.  Of more than 36 000 persons screened, 78 developed a first myocardial infarction (average 18 months after sampling). Fifty of these had participated in a follow‐up health survey (average 8½ years between surveys) and were sex‐ and age‐matched with 56 referents.

Main outcome measures.  Comparison of plasma homocysteine levels in case and referent subjects before and after development of a first myocardial infarction.

Results.  No statistically significant difference was found between cases and referents regarding homocysteine at baseline or follow‐up. Plasma homocysteine and plasma creatinine increased significantly, and plasma albumin decreased significantly over time. Conditional univariate logistic regression indicated that high homocysteine at follow‐up but not baseline was associated with first myocardial infarction (OR 2.49; 95% CI: 1.03–6.02), but the relation disappeared in multivariate analyses including plasma creatinine and plasma albumin. High plasma creatinine remained associated with first myocardial infarction at both baseline (OR 2.94; 95% CI: 1.05–8.21) and follow‐up (OR 3.38; 95% CI: 1.21–9.48).

Conclusion.  In this study, first myocardial infarction did not cause increased plasma homocysteine concentration.
Two minimal Tat translocases in Bacillus
Authors: Jongbloed Jan D. H. , Grieger Ulrike , Antelmann Haike , Hecker Michael , Nijland Reindert , Bron Sierd , Van Dijl Jan Maarten
Published: November 2004

Activity of the Tat machinery for protein transport across the inner membrane of Escherichia coli and the chloroplast thylakoidal membrane requires the presence of three membrane proteins: TatA, TatB and TatC. Here, we show that the Tat machinery of the Gram‐positive bacterium Bacillus subtilis is very different because it contains at least two minimal Tat translocases, each composed of one specific TatA and one specific TatC component. A third, TatB‐like component is apparently not required. This implies that TatA proteins of B. subtilis perform the functions of both TatA and TatB of E. coli and thylakoids. Notably, the two B. subtilis translocases named TatAdCd and TatAyCy both function as individual, substrate‐specific translocases for the twin‐arginine preproteins PhoD and YwbN, respectively. Importantly, these minimal TatAC translocases of B. subtilis are representative for the Tat machinery of the vast majority of Gram‐positive bacteria, Streptomycetes being the only known exception with TatABC translocases.
Positive control of tylosin biosynthesis: pivotal role of TylR
Authors: Stratigopoulos George , Bate Neil , Cundliffe Eric
Published: November 2004

Control of tylosin production in Streptomyces fradiae features interplay between a repressor, TylQ, and an activator, TylS, during regulation of tylR. The latter encodes a pathway‐specific activator that controls most of the tylosin‐biosynthetic (tyl) genes that are subject to regulation. This was established by targeted gene disruption applied separately to tylR and tylS together with transcript analysis involving reverse transcription polymerase chain reaction (RT‐PCR). TylR controls multiple genes that encode the synthesis or addition of all three tylosin sugars, plus polyketide  ring  oxidation,  and  at  least  one  of the polyketide synthase (PKS) megagenes, tylGI. (Expression of a few tyl genes, plus the resistance determinants tlrB and tlrD, together with some ancillary or unassigned genes, is not apparently regulated during fermentation, consistent with constitutive expression.) In contrast, the only gene known for sure to be directly controlled by TylS is tylR, and there are very few additional candidates. These include the mycinose‐biosynthetic gene, tylJ, and two previously unassigned genes, ORF12* (tylU) plus ORF11* (tylV). TylS also controls the PKS genes [tylGIII‐tylGIV‐tylGV] although not in obligatory fashion. These genes can be transcribed (i.e. tylosin can be produced) in a tylS‐KO strain by forcing overexpression of tylR using a foreign promoter. We therefore suspect that TylS might control the PKS genes indirectly, although this remains to be established unequivocally. Conceivably, the direct effects of TylS are exerted exclusively on other regulators. Tylosin production levels were elevated when tylS or (especially) tylR was overexpressed in S. fradiae wild‐type and yield increments of industrial significance were generated by similar manipulation of an enhanced production strain.
Physical and functional interactions among RNase E, polynucleotide phosphorylase and the cold‐shock protein, CsdA: evidence for a ‘cold shock degradosome’
Authors: Prud’homme‐Généreux Annie , Beran Rudolf K. , Iost Isabelle , Ramey C. Shane , Mackie George A. , Simons Robert W.
Published: November 2004

Escherichia coli contains at least five ATP‐dependent DEAD‐box RNA helicases which may play important roles in macromolecular metabolism, especially in translation and mRNA decay. Here we demonstrate that one member of this family, CsdA, whose expression is induced by cold shock, interacts physically and functionally with RNase E. Three independent approaches show that after a shift of cultures to 15°C, CsdA co‐purifies with RNase E and other components of the RNA degradosome. Moreover, functional assays using reconstituted minimal degradosomes prepared from purified components in vitro show that CsdA can fully replace the resident RNA helicase of the RNA degradosome, RhlB. In addition, under these conditions, CsdA displays RNA‐dependent ATPase activity. Taken together, our data are consistent with a model in which CsdA accumulates during the early stages of cold acclimatization and subsequently assembles into degradosomes with RNase E synthesized in cold‐adapted cultures. These findings show that the RNA degradosome is a flexible macromolecular machine capable of adapting to altered environmental conditions.
CovS/CovR of group B streptococcus: a two‐component global regulatory system involved in virulence
Authors: Lamy Marie‐Cécile , Zouine Mohammed , Fert Juliette , Vergassola Massimo , Couve Elisabeth , Pellegrini Elisabeth , Glaser Philippe , Kunst Frank , Msadek Tarek , Trieu‐Cuot Patrick , Poyart Claire
Published: November 2004

In this study, we carried out a detailed structural and functional analysis of a Streptococcus agalactiae (GBS) two‐component system which is orthologous to the CovS/CovR (CsrS/CsrR) regulatory system of Streptococcus pyogenes. In GBS, covR and covS are part of a seven gene operon transcribed from two promoters that are not regulated by CovR. A ΔcovSR mutant was found to display dramatic phenotypic changes such as increased haemolytic activity and reduced CAMP activity on blood agar. Adherence of the ΔcovSR mutant to epithelial cells was greatly increased and analysis by transmission electron microscopy revealed the presence at its surface of a fibrous extracellular matrix that might be involved in these intercellular interactions. However, the ΔcovSR mutant was unable to initiate growth in RPMI and its viability in human normal serum was greatly impaired. A major finding of this phenotypic analysis was that the CovS/CovR system is important for GBS virulence, as a 3 log increase of the LD50 of the mutant strain was observed in the neonate rat sepsis model. The pleiotropic phenotype of the ΔcovSR mutant is in full agreement with the large number of genes controlled by CovS/CovR as seen by expression profiling analysis, many of which encode potentially secreted or cell surface‐associated proteins: 76 genes are repressed whereas 63 were positively regulated. CovR was shown to bind directly to the regulatory regions of several of these genes and a consensus CovR recognition sequence was proposed using both DNase I footprinting and computational analyses.
Mutations in ribosomal protein L3 and 23S ribosomal RNA at the peptidyl transferase centre are associated with reduced susceptibility to tiamulin in Brachyspira spp. isolates
Authors: Pringle Märit , Poehlsgaard Jacob , Vester Birte , Long Katherine S.
Published: November 2004

The pleuromutilin antibiotic tiamulin binds to the ribosomal peptidyl transferase centre. Three groups of Brachyspira spp. isolates with reduced tiamulin susceptibility were analysed to define resistance mechanisms to the drug. Mutations were identified in genes encoding ribosomal protein L3 and 23S rRNA at positions proximal to the peptidyl transferase centre. In two groups of laboratory‐selected mutants, mutations were found at nucleotide positions 2032, 2055, 2447, 2499, 2504 and 2572 of 23S rRNA (Escherichia coli numbering) and at amino acid positions 148 and 149 of ribosomal protein L3 (Brachyspira pilosicoli numbering). In a third group of clinical B. hyodysenteriae isolates, only a single mutation at amino acid 148 of ribosomal protein L3 was detected. Chemical footprinting experiments show a reduced binding of tiamulin to ribosomal subunits from mutants with decreased susceptibility to the drug. This reduction in drug binding is likely the resistance mechanism for these strains. Hence, the identified mutations located near the tiamulin binding site are predicted to be responsible for the resistance phenotype. The positions of the mutated residues relative to the bound drug advocate a model where the mutations affect tiamulin binding indirectly through perturbation of nucleotide U2504.
Natural‐abundance isotope ratio mass spectrometry as a means of evaluating carbon redistribution during glucose–citrate cofermentation by Lactococcus lactis
Authors: Mahmoud Mohamed , Gentil Emmanuel , Robins Richard J.
Published: November 2004

The cometabolism of citrate and glucose by growing Lactococcus lactis ssp. lactis bv. diacetylactis was studied using a natural‐abundance stable isotope technique. By a judicious choice of substrates differing slightly in their 13C/12C ratios, the simultaneous metabolism of citrate and glucose to a range of compounds was analysed. These end‐products include lactate, acetate, formate, diacetyl and acetoin. All these products have pyruvate as a common intermediate. With the objective of estimating the degree to which glucose and citrate metabolism through pyruvate may be differentially regulated, the δ13C values of the products accumulated over a wide range of concentrations of citrate and glucose were compared. It was found that, whereas the relative accumulation of different products responds to both the substrate concentration and the ratio between the substrates, the δ13C values of the products primarily reflect the availability of the two substrates over the entire range examined. It can be concluded that in actively growing L. lactis the maintenance of pyruvate homeostasis takes precedence over the redox status of the cells as a regulatory factor.
Functional analysis of the basic helix‐loop‐helix transcription factor DEC1 in circadian regulation
Authors: Sato Fuyuki , Kawamoto Takeshi , Fujimoto Katsumi , Noshiro Mitsuhide , Honda Kiyomasa K. , Honma Sato , Honma Ken‐ichi , Kato Yukio
Published: November 2004

The basic helix‐loop‐helix transcription factor DEC1 is expressed in a circadian manner in the suprachiasmatic nucleus where it seems to play a role in regulating the mammalian circadian rhythm by suppressing the CLOCK/BMAL1‐activated promoter. The interaction of DEC1 with BMAL1 has been suggested as one of the molecular mechanisms of the suppression [Honma, S., Kawamoto, T., Takagi, Y., Fujimoto, K., Sato, F., Noshiro, M., Kato, Y. & Honma, K. (2002) Nature419, 841–844]. Deletion analysis of DEC1 demonstrated that its N‐terminal region, which includes the basic helix‐loop‐helix domain, was essential for both the suppressive activity and the interaction with BMAL1, as DEC1 lacking the basic region did not show any suppression or interaction. Furthermore, we found that Arg65 in the basic region, which is conserved among group B basic helix‐loop‐helix proteins, was responsible for the suppression, for the interaction with BMAL1 and for its binding to CACGTG E‐boxes. However, substitution of His57 for Ala significantly reduced the E‐box binding activity of DEC1, although it did not affect the interaction with BMAL1 or suppression of CLOCK/BMAL1‐induced transcription. On the other hand, the basic region‐deleted DEC1 acted in a dominant‐negative manner for DEC1 activity, indicating that the basic region was not required for homodimer formation of DEC1. Moreover, mutant DEC1 also counteracted DEC2‐mediated suppressive activity in a dominant‐negative manner. The heterodimer formation of DEC1 and DEC2 was confirmed by pull‐down assay. These findings suggest that the basic region of DEC1 participates in the transcriptional regulation through a protein–protein interaction with BMAL1 and DNA binding to the E‐box.
Modulation of cyclin D1 and early growth response factor‐1 gene expression in interleukin‐1β‐treated rat smooth muscle cells by n‐6 and n‐3 polyunsaturated fatty acids
Authors: Bousserouel Souad , Raymondjean Michel , Brouillet Arthur , Béréziat Gilbert , Andréani Marise
Published: November 2004

The proliferation of smooth muscle cells (SMC) is a key event in the development of atherosclerosis. In addition to growth factors or cytokines, we have shown previously that n‐3 polyunsaturated fatty acids (PUFAs) act in opposition to n‐6 PUFAs by modulating various steps of the inflammatory process. We have investigated the molecular mechanisms by which the incorporation of the n‐6 PUFA, arachidonic acid, increases the proliferation of rat SMC treated with interleukin‐1β, while the n‐3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), elicit no mitogenic response. Incorporation of EPA or DHA into SMC, which are then activated by interleukin‐1β to mimic inflammation, decreases promoter activity of the cyclin D1 gene and phosphorylation of the retinoblastoma protein. Together, our data demonstrate that n‐3 effects are dependent on the Ras/Raf‐1/extracellular signal regulated kinase (ERK)/mitogen‐activated protein kinase pathway, and that down‐regulation of the cyclin D1 promoter activity is mediated by the specific binding of the early growth response factor‐1. Finally, we have shown that the incorporation of EPA and DHA also increased the concentration of caveolin‐1 and caveolin‐3 in caveolae, which correlated with n‐3 PUFA inhibition of SMC proliferation through the mitogen‐activated protein kinase pathway. We provide evidence indicating that, in contrast to n‐6 PUFAs, n‐3 PUFAs exert antiproliferative effects on SMC through the mitogen‐activated protein kinase/ERK pathway.
Functional dissection of a small anaerobically induced bZIP transcription factor from tomato
Authors: Sell Simone , Hehl Reinhard
Published: November 2004

A small anaerobically induced tomato transcription factor was isolated from a subtractive library. This factor, designated ABZ1 (anaerobic basic leucine zipper), is anaerobically induced in fruits, leaves and roots and encodes a nuclear localized protein. ABZ1 shares close structural and sequence homology with the S‐family of small basic leucine zipper (bZIP) transcription factors that are implicated in stress response. Nuclear localization of ABZ1 is mediated by the basic region and occurs under normoxic conditions. ABZ1 binds to G‐box‐like target sites as a dimer. Binding can be abolished by heterodimerization with a truncated protein retaining the leucine zipper but lacking the DNA binding domain. The protein binds in a sequence specific manner to the CaMV 35S promoter which is down regulated when ABZ1 is coexpressed. This correlates with the anaerobic down regulation of the 35S promoter in tomato and tobacco. These results may suggest that small bZIP proteins are involved in the negative regulation of gene expression under anaerobic conditions.
The mechanism of α‐proton isotope exchange in amino acids catalysed by tyrosine phenol‐lyase
Authors: Faleev Nicolai G. , Demidkina Tatyana V. , Tsvetikova Marina A. , Phillips Robert S. , Yamskov Igor A.
Published: November 2004

To shed light on the mechanism of isotopic exchange of α‐protons in amino acids catalyzed by pyridoxal phosphate (PLP)‐dependent enzymes, we studied the kinetics of quinonoid intermediate formation for the reactions of tyrosine phenol‐lyase with l‐phenylalanine, l‐methionine, and their α‐deuterated analogues in D2O, and we compared the results with the rates of the isotopic exchange under the same conditions. We have found that, in the l‐phenylalanine reaction, the internal return of the α‐proton is operative, and allowing for its effect, the exchange rate is accounted for satisfactorily. Surprisingly, for the reaction with l‐methionine, the enzymatic isotope exchange went much faster than might be predicted from the kinetic data for quinonoid intermediate formation. This result allows us to suggest the existence of an alternative, possibly concerted, mechanism of α‐proton exchange.
Alternative initiation of transcription of the human presenilin 1 gene in SH‐SY5Y and SK‐N‐SH cells
Authors: Pastorcic Martine , Das Hriday K.
Published: November 2004

We have identified DNA sequences required for the expression of the presenilin 1 (PS1) gene. A promoter region has been mapped in SK‐N‐SH cells and includes sequences between −118 and +178 flanking the major initiation site (+1). The PS1 gene is also efficiently transcribed in the SH‐SY5Y subclone of SK‐N‐SH cells. However the promoter appears to be utilized in alternative ways in both cell types. Sequences both upstream as well as downstream from the initiation site mapped in SK‐N‐SH cells were shown by 5′‐ and 3′‐deletion analysis to play a crucial role in both cell lines. However, in SH‐SY5Y cells either upstream or downstream sequences are sufficient to direct transcription, whereas in SK‐N‐SH cells 5′‐deletions past the +1 site eliminate over0 95% of transcription. Several Ets motifs (GGAA) as well as Sp1 motifs [(G/T)GGCGGRRY] are juxtaposed both upstream and downstream from +1. To understand how the promoter may be utilized alternatively in different cell types we have examined the effect of point mutations in these elements. Altering an Ets motif at −10 eliminates 80% of transcription in SK‐N‐SH cells whereas the same mutation has only a minor effect in SH‐SY5Y cells. Conversely, mutation of the Ets element at +90, which eliminates 70% of transcription in SH‐SY5Y cells, has a lesser effect in SK‐N‐SH cells. In both cell types a promoter including mutations at both −10 and +90 sites loses over 90% transcription activity indicating the crucial importance of these two Ets motifs. The effect of Sp1 mutations appears to be similar in both cell types. Hence the differential expression in each cell type may be at least partially determined by Ets factors and the −10/+90 sites. We have identified several Ets factors that recognize specifically the −10 Ets motif by the yeast one‐hybrid selection including avian erythroblastosis virus E26 oncogene homologue 2, Ets‐like gene 1, Ets translocation variant 1 and Ets related molecule (ERM). We show here that ERM specifically recognizes Ets motifs on the PS1 promoter located at −10 as well as downstream at +90, +129 and +165 and activates PS1 transcription with promoter fragments containing or not the −10 Ets site.
Effect of calmidazolium on Ca2+ movement and proliferation in human osteosarcoma cells
Authors: Tseng Li‐Lin , Huang Chun‐Jen , Hsu Shu‐Shong , Chen Jin‐Shyr , Cheng He‐Hsiung , Chang Hong‐Tai , Jiann Bang‐Ping , Jan Chung‐Ren
Published: November 2004

1. In human MG63 osteosarcoma cells, the effect of calmidazolium on [Ca2+]i and proliferation was explored using fura‐2 and ELISA, respectively.

2. Calmidazolium, at concentrations greater than 0.1 µmol/L, caused a rapid increase in [Ca2+]i in a concentration‐dependent manner (EC50 = 0.5 µmol/L). The calmidazolium‐induced [Ca2+]i increase was reduced by 66% by removal of extracellular Ca2+. In Ca2+‐free medium, thapsigargin, an inhibitor of the endoplasmic reticulum Ca2+‐ATPase, caused a monophasic increase in [Ca2+]i, after which the effect of calmidazolium to increase [Ca2+]i was completely inhibited. U73122, an inhibitor of phospholipase C (PLC), abolished histamine (but not calmidazolium)‐induced increases in [Ca2+]i. Pretreatment with phorbol 12‐myristate 13‐acetate to activate protein kinase C inhibited the calmidazolium‐induced increase in [Ca2+]i in Ca2+‐containing medium by 47%.

3. Separately, it was found that overnight treatment with 2–10 µmol/L calmidazolium inhibited cell proliferation in a concentration‐dependent manner.

4. These results suggest that calmidazolium increases [Ca2+]i by stimulating extracellular Ca2+ influx and also by causing release of intracellular Ca2+ from the endoplasmic reticulum in a PLC‐independent manner. Calmidazolium may be cytotoxic to osteosarcoma cells.
Biofilm susceptibility to metal toxicity
Authors: Harrison Joe J. , Ceri Howard , Stremick Carol A. , Turner Raymond J.
Published: November 2004

This study compared bacterial biofilm and planktonic cell susceptibility to metal toxicity by evaluating the minimum inhibitory concentration (MIC), the planktonic minimum bactericidal concentration (MBC), and minimum biofilm eradication concentration (MBEC) using the MBEC™ device. In total, 17 metal cations and oxyanions, chosen to represent groups VIB to VIA of the periodic table, were each tested on biofilm and planktonic cultures of Escherichia coli JM109, Staphylococcus aureus ATCC 29213, and Pseudomonas aeruginosa ATCC 27853. In contrast to control antibiotic assays, where biofilm cultures were 2 to 64 times less susceptible to killing than logarithmically growing planktonic bacteria, metal compounds killed planktonic and biofilm cultures at the same concentration in the vast majority of combinations. Our data indicate that, under the conditions reported, growth in a biofilm does not provide resistance to bacteria against killing by metal cations or oxyanions.
Isolation and characterization of soybean‐associated bacteria and their potential for plant growth promotion
Authors: Kuklinsky‐Sobral Júlia , Araújo Welington Luiz , Mendes Rodrigo , Geraldi Isaias Olívio , Pizzirani‐Kleiner Aline Aparecida , Azevedo João Lúcio
Published: November 2004

Endophytic and epiphytic bacteria were isolated from two soybean cultivars (Foscarin and Cristalina). Significant differences were observed in bacterial population densities in relation to season of isolation, soybean growth phase and the tissues from which the isolates  were  obtained.  The  isolates  were  identified by partial 16S rDNA sequence analysis, with most of the isolates belonging to the Pseudomonaceae, Burkholderiacea and Enterobacteriaceae groups. The potential of the isolates for plant growth promotion was evaluated by screening for indoleacetic acid (IAA) production and mineral phosphate solubilization; 34% of endophytic bacteria produced IAA and 49% were able to solubilize mineral phosphate whereas only 21% of epiphytic bacteria produced IAA although 52% were able to solubilize mineral phosphate. A high frequency of IAA producing isolates occurred in the early ripening Foscarin cultivar whereas a high percentage of phosphate solubilizing isolates were obtained from plants in the initial development stage (V6). We also found that 60% of endophytic and 69% of epiphytic isolates that produced IAA and solubilized mineral phosphate were also able to fix nitrogen in vitro. The soybean‐associated bacteria showing characteristics related to plant growth promotion were identified as belonging to the genera Pseudomonas, Ralstonia, Enterobacter, Pantoea and Acinetobacter.
Pili bigemini complicating diode laser hair removal
Authors: Kaniowska E
Published: November 2004

After two diode laser treatments for hair removal, a 39‐year‐old woman was noted to have pili bigemini within the treated areas. It resolved after a third treatment.

 Pili bigemini, the appearance of two hairs coming from the same follicular opening, can be induced by intermediate doses of laser energy. It follows sublethal damage to the hair follicule apparatus.
Sunscreen application at the beach
Authors: Lademann J , Schanzer S , Richter H , Pelchrzim R V , Zastrow L , Golz K , Sterry W
Published: November 2004

Background  The sun protection factor (SPF) of sunscreens is determined after application of a standard amount. The European Cosmetic Toiletry and Perfumery Association (COLIPA) standard amount is 2 mg/cm2. Real‐life application of sunscreen is probably less than this.

Aim  To determine the amount of sunscreen present on the skin of people at the beach.

Methods  Volunteers at the beach were selected randomly and were not aware of being tested for the adequacy of their sunscreen application. All volunteers had applied sunscreen. Application had been more than 30 min before testing (sometimes up to 4 h earlier). The amounts of sunscreen applied to different body sites were determined quantitatively by tape stripping. Actual amounts of sunscreen applied were compared with the COLIPA standard. Also, sunscreen containing a fluorescent dye was applied to the skin of volunteers in a laboratory setting. The distribution of sunscreen application was visualized by UVA photography in a darkened room.

Results  Sixty volunteers, 33 males and 27 females, aged 17–68 years (median 32 years), were recruited at the beach. Sunscreen coverage was inadequate at all body sites. Coverage at various body sites differed greatly. Most volunteers had applied 10% or less of the COLIPA standard amount to all body sites assessed. The best protected areas were the upper arm and décolleté but, even in these areas, most volunteers had only applied 10% of the COLIPA standard amount. The worst protected areas were the ears and top of the feet. The back was typically badly protected if treated by the volunteers themselves. The back was better protected if another person had applied the sunscreen. In the laboratory, the fluorescent dye‐containing sunscreen showed the same pattern of sunscreen application as at the beach.

Conclusions  In real life, at the beach, very little sunscreen remains present on the skin.
Application of sunscreen preparations among young Polish people
Authors: Szepietowski Jacek C , Nowicka Danuta , Reich Adam , Melon Monika
Published: November 2004

Background  The efficacy of sunscreens is assessed on the basis that 15–20 g/m2 (1.5–2 mg/cm2) is applied. However, expecting people to apply such large amounts is perhaps unrealistic.

Aim  To evaluate the application of sunscreen usage by young people.

Materials and methods  Forty‐nine subjects (24 females and 25 males) in the age range 18–32 years (mean 23.1 years) were included in the study. They were asked to apply sun protection factor (SPF) to the whole of their own skin surface in just the same way that they would customarily do it during/prior to sun exposure. Two agents were applied: emulsion with SPF30 and a fatty cream with SPF > 60. The amount of preparation used/m2 was calculated. Statistical analysis was performed using the Student's t‐test.

Results  The average amount of both preparations used was about half that expected to achieve correct sun protection (p < 0.00001). The mean applied amount of the fatty cream was 9.6 ± 5.3 g/m2 (50.7% of the ideal value) and the emulsion 9.2 ± 5.5 g/m2 (48.6% of the ideal value). Neither gender (male/female) nor type of agent (emulsion/fatty cream) affected the amount used.

Conclusions  Young people customarily apply less than 10 g of SPF/m2. It is therefore unrealistic and possibly even misleading of manufacturers to assess SPF ratings as if people applied 15–20 g of SPF/m2. Perhaps it is for manufacture's to increase the efficacy of their products rather than for consumers to be asked to apply twice as much?
Plant phenology‐mediated indirect effects: The gall midge opens the phenological window wider for a leaf beetle
Authors: MIYAMOTO Yasushi , NAKAMURA Masahiro
Published: November 2004

We examined whether larvae of the gall midge Rabdophaga rigidae (Diptera: Cecidomyiidae) can modify the seasonal dynamics of the density of a leaf beetle, Plagiodera versicolora (Coleoptera: Chrysomelidae), by modifying the leaf flushing phenology of its host willow species, Salix serissaefolia and Salix eriocarpa (Salicaceae). To test this, we conducted field observations and a laboratory experiment. The field observations demonstrated that the leaf flushing phenology of the willows and the seasonal dynamics of the beetle density differed between shoots with stem galls and shoots without them. On galled shoots of both willow species, secondary shoot growth and secondary leaf production were promoted; consequently, leaf production showed a bimodal pattern and leaf production periods were 1 to 2 months longer than on non‐galled shoots. The adult beetle density on galled shoots was thus enhanced late in the season, and was found to change seasonally, synchronizing with the production of new leaves on the host willow species. From the results of our laboratory experiment, we attributed this synchrony between adult beetle density and willow leaf flush to beetles’ preference to eat new leaves rather than old. Indeed, beetles consumed five times more of the young leaves when they were fed both young and old leaves. These results indicate that stem galls indirectly enhance the adult beetle density by enhancing food quality and quantity late in the beetle‐feeding season. We therefore conclude that midge galls widen the phenological window for leaf beetles by extending the willows’ leaf flush periods.
Distribution of the oceanic insects Halobates (Hemiptera: Gerridae) off the south coast of Japan
Authors: IKAWA Terumi , OKABE Hidehiko , HOSHIZAKI Sugihiko , KAMIKADO Takahiro , CHENG Lanna
Published: November 2004

Specimens of ocean skaters Halobates were collected off the south coast of Japan in the East China Sea in 1995, and from the Kumano‐nada Sea to the East China Sea in 1998 and 1999. Three species were identified: H. micans, H. germanus and H. sericeus. We found two species co‐occurring in comparable densities in different years, a phenomenon not hitherto reported in other regions of the ocean. We discuss distributions of the three Halobates species with special reference to the influence of the Kuroshio Current, temporal variations of sea‐surface temperature, and monsoonal winds.
Biosystematic study of Issikiocrania japonicella Moriuti (Lepidoptera: Eriocraniidae), with description of immature stages
Authors: MIZUKAWA Hitomi , HIROWATARI Toshiya , HASHIMOTO Satoshi
Published: November 2004

The larval and pupal morphology of the eriocraniid species Issikiocrania japonicella Moriuti, 1982 is examined and described for the first time. Unique characters on the thorax and the ninth abdominal segment were recognized in the larval chaetotaxy, but evaluation of the characters remains unresolved. Redescription of the adult morphology, including mouth parts, wing markings and venation, and male and female genitalia, is also given. Four new localities are recorded from Aomori, Nagano, Aichi and Osaka prefectures. Fagus crenata Blume (Fagaceae) was determined as the larval host plant from rearings. The morphology of adult and immature stages suggests that Issikiocrania is a unique genus that retains many primitive features.
Bone level change at implant‐supported fixed partial dentures with and without cantilever extension after 5 years in function
Authors: Wennström Jan , Zurdo Jose , Karlsson Stig , Ekestubbe Annika , Gröndahl Kerstin , Lindhe Jan
Published: November 2004

Objective: The aim of this study was to retrospectively analyze whether the inclusion of cantilever extensions increased the amount of marginal bone loss at free‐standing, implant‐supported, fixed partial dentures (FPDs) over a 5‐year period of functional loading.

Material and Methods: The patient material comprised 45 periodontally treated, partially dentate patients with a total of 50 free‐standing FPDs supported by implants of the Astra Tech® System. Following FPD placement (baseline) the patients were enrolled in an individually designed supportive care program. A set of criteria was collected at baseline to characterize the FPDs. The primary outcome variable was change in peri‐implant bone level from the time of FPD placement to the 5‐year follow‐up examination. The comparison between FPDs with and without cantilevers was performed at three levels: FPD level, implant level, and surface level. Bivariate analysis was performed by the use of the Mann–Whitney U‐test and stepwise regression analysis was utilized to evaluate the potential influence of confounding factors on the change in peri‐implant bone level.

Results: The overall mean marginal bone loss for the implant‐supported FPDs after 5 years in function was 0.4 mm (SD, 0.76). The bone level change at FPDs placed in the maxilla was significantly greater than that for FPDs in the mandible (0.6 versus 0.2 mm; p<0.05). No statistically significant differences were found with regard to peri‐implant bone level change over the 5 years between FPDs with and without cantilevers at any of the levels of comparisons. The multivariate analysis revealed that the variables jaw of treatment and smoking had a significant influence on peri‐implant bone level change on the FPD level, but not on the implant or surface levels. The model explained only 10% of the observed variance in the bone level change.

Conclusion: The study failed to demonstrate that the presence of cantilever extensions in an FPD had an effect on peri‐implant bone loss.
Functional diversity of electrogenic Na+–HCO3− cotransport in ventricular myocytes from rat, rabbit and guinea pig
Authors: Yamamoto Taku , Swietach Pawel , Rossini Alessandra , Loh Shih‐Hurng , Vaughan‐Jones Richard D. , Spitzer Kenneth W.
Published: November 2004

The Na+–HCO3− cotransporter (NBC) is an important sarcolemmal acid extruder in cardiac muscle. The characteristics of NBC expressed functionally in heart are controversial, with reports suggesting electroneutral (NBCn; 1HCO3− : 1Na+; coupling coefficient N= 1) or electrogenic forms of the transporter (NBCe; equivalent to 2HCO3− : 1Na+; N= 2). We have used voltage‐clamp and epifluorescence techniques to compare NBC activity in isolated ventricular myocytes from rabbit, rat and guinea pig. Depolarization (by voltage clamp or hyperkalaemia) reversibly increased steady‐state pHi while hyperpolarization decreased it, effects seen only in CO2/HCO3−‐buffered solutions, and blocked by S0859 (cardiac NBC inhibitor). Species differences in amplitude of these pHi changes were rat > guinea pig ≈ rabbit. Tonic depolarization (−140 mV to −0 mV) accelerated NBC‐mediated pHi recovery from an intracellular acid load. At 0 mV, NBC‐mediated outward current at resting pHi was +0.52 ± 0.05 pA pF−1 (rat, n= 5), +0.26 ± 0.05 pA pF−1 (guinea pig, n= 5) and +0.10 ± 0.03 pA pF−1 (rabbit, n= 9), with reversal potentials near −100 mV, consistent with N= 2. The above results indicate a functionally active voltage‐sensitive NBCe in these species. Voltage‐clamp hyperpolarization negative to the reversal potential for NBCe failed, however, to terminate or reverse NBC‐mediated pHi‐recovery from an acid load although it was slowed significantly, suggesting electroneutral NBC may also be operational. NBC‐mediated pHi recovery was associated with a rise of [Na+]i at a rate ∼25% of that mediated via NHE, and consistent with an apparent NBC stoichiometry between N= 1 and N= 2. In conclusion, NBCe in the ventricular myocyte displays considerable functional variation among the three species tested (greatest in rat, least in rabbit) and may coexist with some NBCn activity.
Directional analysis of coherent oscillatory field potentials in the cerebral cortex and basal ganglia of the rat
Authors: Sharott Andrew , Magill Peter J. , Bolam J. Paul , Brown Peter
Published: November 2004

Population activity in cortico‐basal ganglia circuits is synchronized at different frequencies according to brain state. However, the structures that are likely to drive the synchronization of activity in these circuits remain unclear. Furthermore, it is not known whether the direction of transmission of activity is fixed or dependent on brain state. We have used the directed transfer function (DTF) to investigate the direction in which coherent activity is effectively driven in cortico‐basal ganglia circuits. Local field potentials (LFPs) were simultaneously recorded in the subthalamic nucleus (STN), globus pallidus (GP) and substantia nigra pars reticulata (SNr), together with the ipsilateral frontal electrocorticogram (ECoG) of anaesthetized rats. Directional analysis was performed on recordings made during robust cortical slow‐wave activity (SWA) and ‘global activation’. During SWA, there was coherence at ∼1 Hz between ECoG and basal ganglia LFPs, with much of the coherent activity directed from cortex to basal ganglia. There were similar coherent activities at ∼1 Hz within the basal ganglia, with more activity directed from SNr to GP and STN, and from STN to GP rather than vice versa. During global activation, peaks in coherent activity were seen at higher frequencies (15–60 Hz), with most coherence also directed from cortex to basal ganglia. Within the basal ganglia, however, coherence was predominantly directed from GP to STN and SNr. Together, these results highlight a lead role for the cortex in activity relationships with the basal ganglia, and further suggest that the effective direction of coupling between basal ganglia nuclei is dynamically organized according to brain state, with activity relationships involving the GP displaying the greatest capacity to change.
Alterations in insulin receptor signalling in the rat epitrochlearis muscle upon cessation of voluntary exercise
Authors: Kump David S. , Booth Frank W.
Published: November 2004

The major purpose of this study was to elucidate mechanisms by which decreasing enhanced physical activity induces decreased insulin sensitivity in skeletal muscle. Rats with access to voluntary running wheels for 3 weeks had their wheels locked for 5 h (WL5), 29 h (WL29), or 53 h (WL53); a separate group of rats never had wheel access (sedentary, SED). Relative to WL5, submaximal insulin‐stimulated 2‐deoxyglucose uptake into the epitrochlearis muscle was lower in WL53 and SED. Insulin binding, insulin receptor β‐subunit (IRβ) protein level, submaximal insulin‐stimulated IRβ tyrosine phosphorylation, and glucose transporter‐4 protein level were each lower in both WL53 and SED than in WL5 and WL29. Akt/protein kinase B Ser473 phosphorylation was lower in WL53 and SED than in WL5. Protein levels of protein tyrosine phosphatase‐1B, Src homology phosphatase‐2, and protein kinase C‐θ did not vary among groups. The amount of protein tyrosine phosphatase‐1B, Src homology phosphatase‐2, and protein kinase C‐θ associated with IRβ in insulin‐stimulated muscle also did not differ among the four groups. The mean of SED and WL53 had a significantly higher IRβ‐associated protein tyrosine phosphatase‐1B than the mean of WL5 and WL29. The enclosure of multiple changes (decreases in insulin binding, IRβ protein, IRβ tyrosine phosphorylation, and glucose transporter‐4 protein) in the epitrochlearis muscle within the 29th to 53rd hour after cessation of voluntary wheel running raises the possibility that a single regulatory event could be responsible for the coordinated decrease.
Intracellular calcium store filling by an L‐type calcium current in the basolateral amygdala at subthreshold membrane potentials
Authors: Power John M. , Sah Pankaj
Published: November 2004

The long‐term changes that underlie learning and memory are activated by rises in intracellular Ca2+ that activate a number of signalling pathways and trigger changes in gene transcription. Ca2+ rises due to influx via L‐type voltage‐dependent Ca2+ channels (L‐VDCCs) and release from intracellular Ca2+ stores have been consistently implicated in the biochemical cascades that underlie the final changes in memory formation. Here, we show that pyramidal neurones in the basolateral amygdala express an L‐VDCC that is active at resting membrane potentials. Subthreshold depolarization of neurones either by current injection or summating synaptic potentials led to a sustained rise in cytosolic Ca2+ that was blocked by the dihydropyridine nicardipine. Activation of metabotropic receptors released Ca2+ from intracellular Ca2+ stores. At hyperpolarized potentials, metabotropic‐evoked store release ran down with repeated stimulation. Depolarization of cells to −50 mV, or maintaining them at the resting membrane potential, restored release from intracellular Ca2+ stores, an effect that was blocked by nicardipine. These results show that Ca2+ influx via a low‐voltage‐activated L‐type Ca2+ current refills inositol 1,4,5‐trisphosphate (IP3)‐sensitive intracellular Ca2+ stores, and maintains Ca2+ release and wave generation by metabotropic receptor activation.
Cellular sources, targets and actions of constitutive nitric oxide in the magnocellular neurosecretory system of the rat
Authors: Stern Javier E. , Zhang Wenfeng
Published: November 2004

Nitric oxide (NO) is a key activity‐dependent modulator of the magnocellular neurosecretory system (MNS) during conditions of high hormonal demand. In addition, recent studies support the presence of a functional consitutive NO tone. The aim of this study was to identify the cellular sources, targets, signalling mechanisms and functional relevance of constitutive NO production within the supraoptic nucleus (SON). Direct visualization of intracellular NO, along with neuronal nitric oxide synthase (nNOS) and cGMP immunohistochemisty, was used to study the cellular sources and targets of NO within the SON, respectively. Our results support the presence of a strong NO basal tone within the SON, and indicate that vasopressin (VP) neurones constitute the major neuronal source and target of basal NO. NO induced‐fluorescence and cGMP immunoreactivity (cGMPir) were also found in the glia and microvasculature of the SON, suggesting that they contribute as sources/targets of NO within the SON. cGMPir was also found in association with glutamic acid decarboxylase 67 (GAD67)‐  and vesicular glutamate transporter 2 (VGLUT2)‐positive terminals. Glutamate, acting on NMDA and possibly AMPA receptors, was found to be an important neurotransmitter driving basal NO production within the SON. Finally, electrophysiological recordings obtained from SON neurones in a slice preparation indicated that constitutive NO efficiently restrains ongoing firing activity of these neurones. Furthermore, phasically active (putative VP) and continuously firing neurones appeared to be influenced by NO originating from different sources. The potential roles for basal NO as an autocrine signalling molecule, and one that bridges neuronal–glial–vascular interactions within the MNS are discussed.
Lactate and force production in skeletal muscle
Authors: Kristensen Michael , Albertsen Janni , Rentsch Maria , Juel Carsten
Published: November 2004

Lactic acid accumulation is generally believed to be involved in muscle fatigue. However, one study reported that in rat soleus muscle (in vitro), with force depressed by high external K+ concentrations a subsequent incubation with lactic acid restores force and thereby protects against fatigue. However, incubation with 20 mm lactic acid reduces the pH gradient across the sarcolemma, whereas the gradient is increased during muscle activity. Furthermore, unlike active muscle the Na+–K+ pump is not activated. We therefore hypothesized that lactic acid does not protect against fatigue in active muscle. Three incubation solutions were used: 20 mm Na‐lactate (which acidifies internal pH), 12 mm Na‐lactate +8 mm lactic acid (which mimics the pH changes during muscle activity), and 20 mm lactic acid (which acidifies external pH more than internal pH). All three solutions improved force in K+‐depressed rat soleus muscle. The pH regulation associated with lactate incubation accelerated the Na+–K+ pump. To study whether the protective effect of lactate/lactic acid is a general mechanism, we stimulated muscles to fatigue with and without pre‐incubation. None of the incubation solutions improved force development in repetitively stimulated muscle (Na‐lactate had a negative effect). It is concluded that although lactate/lactic acid incubation regains force in K+‐depressed resting muscle, a similar incubation has no or a negative effect on force development in active muscle. It is suggested that the difference between the two situations is that lactate/lactic acid removes the negative consequences of an unusual large depolarization in the K+‐treated passive muscle, whereas the depolarization is less pronounced in active muscle.
ITERATIVE DEVICES GENERATING INFINITE WORDS
Authors: CULIK II KAREL , KARHUMÄKI JUHANI
Published: November 2004

We consider various TAG-like devices that generate one-way infinite words in real time. The simplest types of these devices are equivalent to iterative morphisms (also called substitutions), automatic sequences and iterative DGSM’s. We consider also a few new types. Mainly we study the comparative power of these mechanisms and develop some techniques for proving that certain devices cannot produce a particular infinite word.