bluuebunny/crossref_metadata_2025 huggingface dataset:
Lack of effect of repeated suberythemal ultraviolet‐B exposures on human blood dendritic subtypes
Authors: Narbutt Joanna , Lesiak Aleksandra , Skibinska Malgorzta , Wozniacka Anna , Sysa‐Jedrzejowska Anna , Zalewska Anna , Robak Tadeusz , Norval Mary , Smolewski Piotr
Published: September 2005

Background/purpose: Dendritic cells (DC) play a major role in the afferent immune response. They are found as a minor cell population in the blood as three main subtypes that can be distinguished phenotypically: plasmacytoid DC (PDC), and myeloid DC1 and 2 (MDC1 and 2). The aim of the study was to examine the effect of repeated whole‐body suberythemal ultraviolet (UV) B irradiation on the percentages of DC subsets in the blood and skin, and to test for photoadaptation by the subsequent administration of a local erythemal UV dose.

Methods: Thirty subjects in each group were irradiated with either 0.7 personal minimal erythema dose (MED) UVB daily for 10 days (whole body), or for the 10 days followed by a single three MED UVB exposure of a local body site, or with the single three MED UVB exposure of a local body site only. Blood was collected before and after the exposures and the percentage of DC and DC subtypes assessed by flow cytometry. Skin biopsies were collected at the same times, and the number and position of the DC subsets examined by immunofluorescent microscopy.

Results: The whole‐body repeated UVB irradiations did not result in a change in the blood DC (BDC) or the subsets percentages in the blood, except that there was a small but significant rise in the percentage of the MDC2 subset. No alteration occurred following the local erythemal UVB exposure. The total number of BDC in the skin was small, with the PDC being located mainly in the dermis and the myeloid subtypes mainly in the epidermis. No change in cutaneous numbers or distribution was revealed following the irradiation protocols.

Conclusions: Repeated whole‐body suberythemal UVB irradiation does not cause a change in BDC or BDC subsets in the blood or skin, except for a small increase in the percentage of MDC2 in the blood. Local erythemal UVB irradiation does not alter the BDC subsets in blood or skin.
Solar angioedema: an uncommonly recognized condition?
Authors: Rose R. F. , Bhushan M. , King C. M. , Rhodes L. E.
Published: September 2005

Solar urticaria is a well defined although uncommon photosensitivity disorder, and is said to be the underlying cause of chronic urticaria in approximately 0.5% cases. In contrast, solar angioedema is seldom reported. We describe two patients with postulated solar angioedema, associated with clinical and/or phototest features of solar urticaria. Recognition of solar provocation of angioedema has important consequences for patient management.
Ultraviolet tanning equipment: six questions
Authors: Van Der Leun Jan C. , Forbes Paul Donald
Published: September 2005

Recreational tanning, particularly as promoted by commercial salons with ‘sunbeds’ or booths, has generated increasing attention from the regulatory and the biomedical communities. Several agencies have weighed in with opinions on recommended modifications in guidelines, training procedures, regulatory controls, and consumer awareness. Currently there is little uniformity in the guidance provided by trade groups, in recommendations supplied by health agencies and medical associations, or in regulatory approaches taken or proposed by the many countries involved.

In an effort to provide a clearer focus for its concerns in this area, the EU Directorate General Health and Consumer Affairs formulated six questions on ultraviolet (UV) tanning, all of a technical or biomedical nature. The questions were stimulated in part by the fact that the European Commission no longer regards the European standard EN 60335‐2‐27:1997 (‘Particular requirements for appliances for skin exposure to ultraviolet and infrared radiation’) as giving presumption of conformity to the Low Voltage Directive 73/23/EEC. (The latter Directive governs marketing of electrical devices in EC countries.) Initially, the questions were posed to an EU Scientific Committee. Subsequently, industry representatives and the European Commission jointly requested that the scientific community provide answers to the questions.

We received the questions with a request for our technical responses and opinions. Our response was in the form of the following essay, submitted earlier this year to the European Commission. We offer it here in the hope of stimulating constructive discussion and comment.
Selective CCK‐A but not CCK‐B receptor antagonists inhibit HT‐29 cell proliferation: synergism with pharmacological levels of melatonin
Authors: González‐Puga Cristina , García‐Navarro Ana , Escames Germaine , León Josefa , López‐Cantarero Manuel , Ros Eduardo , Acuña‐Castroviejo Darío
Published: September 2005

Abstract:  Some data suggest that cholecystokinin (CCK) receptor agonists stimulate the growth of colon cancer. Melatonin, an endogenous indoleamine with strong antioxidant properties, displays antiproliferative and proapoptotic properties both in vivo or in vitro in several types of tumors. We used HT‐29 human colon cancer cells, expressing CCK receptors, to test the antiproliferative effects of several antagonists of CCK‐A and/or CCK‐B and their possible synergism with melatonin. HT‐29 cells were cultured in RPMI 1640 medium supplemented with fetal bovine serum at 37°C. Cell proliferation was assessed by the incorporation of [3H]‐thymidine into DNA. Annexin V‐FITC plus propidium iodine were used for flow cytometry apoptosis/necrosis evaluation. The following drugs were tested: gastrin (CCK‐B agonist); CCK‐8s (CCK‐A agonist); proglumide (CCK‐A plus CCK‐B antagonist); lorglumide (CCK‐A antagonist); PD 135,158 (CCK‐B antagonist and weak CCK‐A agonist); devazepide or L 364,718 (CCK‐A antagonist); L 365,260 (CCK‐B antagonist), and melatonin. The results shown a lack of effects of gastrin on HT‐29 cell proliferation, whereas CCK‐8s induced proliferation at high doses. The order of the antiproliferative effect of the other drugs was devazepide > lorglumide > proglumide. These drugs produce cell death mainly inducing apoptosis. Melatonin showed strong antiproliferative effect at millimolar concentrations, and it induced apoptotic cell death. Melatonin generally enhanced the antiproliferative effects of devazepide, lorglumide and proglumide and increased the proglumide‐induced apoptosis. These results suggest that melatonin and CCK‐A antagonists are useful for controlling human colon cancer cell growth in culture and in combined therapy significantly increases their efficiency.
Melatonin as a local regulator of human placental function
Authors: Iwasaki Shinya , Nakazawa Kazumi , Sakai Jun , Kometani Kunio , Iwashita Mitsutoshi , Yoshimura Yasunori , Maruyama Tetsuo
Published: September 2005

Abstract:  Melatonin plays a critical role in a variety of mammalian reproductive processes not only acting on the central nervous system but also behaving as a peripheral physiologic regulator. To address the relevance of melatonin to the maintenance of pregnancy at the feto‐maternal interface, we investigated the expression of two types of membrane melatonin receptors, MT1 and MT2, as well as arylalkylamine N‐acetyltransferase (AA‐NAT) and hydroxyindole‐O‐methyltransferase (HIOMT), the two enzymes required for the conversion of serotonin to melatonin, in the human placenta and the effect of melatonin on the release of human chorionic gonadotropin (hCG) from cultured human trophoblast cells. RT‐PCR analysis and DNA sequencing revealed that transcripts of MT1, MT2, AA‐NAT, and HIOMT were present in the first‐trimester human placenta. We also found that melatonin significantly potentiated hCG secretion at optimal concentrations. These results suggest that melatonin may regulate human placental function in a paracrine/autocrine manner, providing evidence for a novel role in human reproduction.
Expression of N‐methyl‐D‐aspartate (NMDA) and α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionate (AMPA) GluR2/3 receptors in the developing rat pineal gland
Authors: Kaur C. , Sivakumar V. , Ling E. A.
Published: September 2005

Abstract:  The expression of α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionate (AMPA) type glutamate (GluR2/3) receptors and N‐methyl‐d‐aspartate receptor subtype 1 (NMDAR1) was carried out by immunohistochemistry, double immunofluorescence and real‐time RT‐PCR analysis in the pineal glands of 1‐day to 6‐wk‐old rats in the present study. GluR2/3 immunopositive cells were distributed throughout the pineal gland and showed branching processes in all age groups. The NMDAR1 immunoreactivity, however, was observed in fewer branched cells. A constitutive mRNA expression of NMDAR1, GluR2 and GluR3 was detected in the pineal glands of various ages and showed no significant difference between the age groups studied. Immunohistochemical and double immunofluorescence results showed that the GluR2/3 were mainly expressed and co‐localized with OX‐42‐positive microglia/macrophages and the glial fibrillary acidic protein (GFAP)‐positive astrocytes. Co‐localization of NMDAR1 with OX‐42‐ and GFAP‐positive cells was much less. The expression of these receptors on the glial cells suggests that they may be involved in the development and growth of the pineal gland in the early postnatal period (1 day to 3 wk) and subsequently in the regulation of melatonin synthesis.
Biotransformation of melatonin in human breast cancer cell lines: role of sulfotransferase 1A1
Authors: Aust Sylvia , Jaeger Walter , Klimpfinger Martin , Mayer Klaus , Baravalle Günther , Ekmekcioglu Cem , Thalhammer Theresia
Published: September 2005

Abstract:  The biologically active melatonin metabolite, 6‐hydroxymelatonin (6‐OHMel), is conjugated to form 6‐hydroxymelatonin sulfate (6‐OHMelS). To elucidate the role of the sulfotransferase (SULT) enzyme 1A1, considerably expressed in normal and malignant human breast cells, we measured the formation of 6‐OHMelS by ELISA in hormone‐dependent MCF‐7 and hormone‐independent MDA‐MB231 (MDA) breast cancer cell lines after stable transfection with SULT1A1. In parent MDA cells, low SULT1A1 mRNA expression was associated with moderate 6‐OHMelS formation as determined after application (24 hr) of 0.1 μm 6‐OHMel. As expected, overexpression of SULT1A1 in MDA cells resulted in a 2.9‐ and 110‐fold increase in 6‐OHMelS in the cytosol and cellular supernatant respectively. Furthermore, 6.3‐ and 115‐fold increases were observed after 0.5 μm, and 12.6‐ and 101‐fold increases after 1 μm 6‐OHMel respectively. In MCF‐7 cells, because of high basal SULT1A1 expression, only two‐ to threefold increases in 6‐OHMelS were observed after transfection with the enzyme. In total, 866 and 539 pmol/mg protein 6‐OHMelS were formed from 1 μm 6‐OHMel in SULT1A1 overexpressing MDA and MCF‐7 cells, respectively, whereas application of 1 μm melatonin produced only <1% of 6‐OHMelS. Possible interactions with the SULT1A1 substrate tamoxifen (tam), an anti‐estrogen applied in the therapy of breast cancer, were also studied. A concentration of 1 μm tam increased 6‐OHMelS formation by approximately threefold in the presence of 1 μm melatonin or 1 μm 6‐OHMel respectively. However, no alterations were detected after application of 1 μm 4‐hydroxy‐tamoxifen. In summary, we demonstrate the importance of SULT1A1 for the biotransformation of 6‐OHMel in human breast cancer cells. Our data further suggest that tam can modulate melatonin biotransformation.
High concentrations of the melatonin metabolite, N1‐acetyl‐N 2‐formyl‐5‐methoxykynuramine, in cerebrospinal fluid of patients with meningitis: a possible immunomodulatory mechanism
Authors: De Oliveira Silva Sueli , Ximenes Valdecir F. , Livramento José A. , Catalani Luiz H. , Campa Ana
Published: September 2005

Abstract:  We evaluated the presence of the melatonin metabolite N1‐acetyl‐N2‐formyl‐5‐methoxykynuramine (AFMK), in cerebrospinal fluid (CSF) of patients with viral meningitis (n = 20) and control samples (n = 8) and correlate AFMK levels with inflammatory markers such as cellularity, protein, tumor necrosis factor (TNF)‐α, interleukin (IL)‐8 and IL‐1β levels. A portion of the CSF was extracted with dichloromethane (1:5) and analyzed by high‐performance liquid chromatography (HPLC) under standardized conditions for AFMK. AFMK was detected in 16 of 20 CSF samples of patients with viral meningitis; the concentration of AFMK was found to be above the quantification limit (50 nmol/L) in six of these samples. AFMK was not detected in any of the eight control samples. The samples were classified into groups according to AFMK levels: undetectable (<10 nmol/L, group I), detectable but below the quantification limit (< 50 nmol/L, group II), and quantified (>50 nmol/L, group III). Group II presented the highest levels of proteins and IL‐8, whereas group III showed the lowest levels of the inflammatory parameters. This study supports our hypothesis that inflammation favors the formation of AFMK and that this compound has immunomodulatory activity in vivo.
Correlation among cytokines, bronchopulmonary dysplasia and modality of ventilation in preterm newborns: improvement with melatonin treatment
Authors: Gitto Eloisa , Reiter Russel J. , Sabatino Giuseppe , Buonocore Giuseppe , Romeo Carmelo , Gitto Placido , Buggé Concetta , Trimarchi Giuseppe , Barberi Ignazio
Published: September 2005

Abstract:  Improved survival because of advances in neonatal care has resulted in an increased number of infants at risk for chronic lung disease. Even though the etiology of lung injury is multifactorial, recent animal and clinical data indicate that pulmonary damage depends in large part on the ventilatory strategies used. Ventilator‐associated lung injury was believed to result from the use of high pressure, thus, the term barotraumas. This trauma is believed to involve free‐radical damage. Oxidant injury is a serious cause of lung injury. In the present study, 110 newborns with respiratory distress syndrome were studied; 55 were treated with melatonin and the other 55 with placebo. All the subjects were mechanically ventilated with or without guaranteed volume. Proinflammatory cytokines [interleukin (IL)‐6, IL‐8 and tumor necrosis factor (TNF)‐α] were measured in tracheobronchial aspirate and the clinical outcome was evaluated. Melatonin treatment reduced the proinflammatory cytokines and improved the clinical outcome. The beneficial action of melatonin presumably related to its antioxidative actions.
Alleviation of maternal hyperthermia‐induced early embryonic death by administration of melatonin to mice
Authors: Matsuzuka Takaya , Sakamoto Natsumi , Ozawa Manabu , Ushitani Atsuko , Hirabayashi Miho , Kanai Yukio
Published: September 2005

Abstract:  Maternal hyperthermia induces early embryonic death via increased oxidative stress to the embryo. In this study, we examined whether melatonin administered to heat‐stressed pregnant mice would reduce hyperthermia‐induced embryonic death. Mice were heat stressed (12 hr at 35°C, 60% relative humidity) on the day of mating and melatonin (3 mg/kg body weight) was injected subcutaneously every 2 hr during heat exposure. Thereafter, zygotes were collected, and in vitro developmental ability and intracellular glutathione (GSH) content were assessed. In addition, reactive oxygen species (ROS) levels and free radical scavenging activity (FRSA) in the oviduct as well as lipid peroxidation in the liver were measured. Melatonin administration was associated with a tendency for higher intracellular GSH content in zygotes (1.67 pmol/zygote) and a significantly higher percentage of embryos that developed to the morula or blastocyst stage (47.91%; P < 0.01) compared with the parameters in heat‐stressed mice that were administered a placebo (1.48 pmol GSH/zygote and 14.78% development). Lipid peroxidation levels in the liver and ROS levels in the oviduct were the same in melatonin‐treated stressed mice and the controls, while these parameters were significantly higher in heat‐stressed mice that were not treated with melatonin. Furthermore, FRSA in the oviduct was significantly (P < 0.05) higher in the melatonin‐treated mice than in the controls. These results suggest that administration of melatonin to heat‐stressed mice alleviates hyperthermia‐induced early embryonic death and that this is accomplished in part by maintaining a neutral redox status within the mother.
Physical activity, body composition and physical self‐esteem: a 3‐year follow‐up study among adolescents in Sweden
Authors: Raustorp A. , Mattsson E. , Svensson K. , Ståhle A.
Published: September 2005

Aims: To measure physical activity by means of daily pedometer steps, body composition, expressed as body mass index (BMI) and bioelectrical impedance as percent body fat, and perceived physical self‐esteem and additionally, to evaluate eventual predictors for a healthy lifestyle i.e., highly physically active, normal weighted and a high physical self‐esteem in a follow‐up group.

Methods: During autumn 2000 physical activity level was assessed and BMI was calculated in 871 children aged 7–14 in south eastern Sweden and in 501 of these, physical self‐esteem were also assessed. During autumn 2003 a total of 375 adolescents aged 15–18 were assessed using the same methodology and additionally percent body fat was measured. Ninety‐three of these adolescents (46 girls), were also measured in 2000 and they formed the follow‐up group.

Results: In the follow‐up group a significant increase in BMI and stability in physical self‐esteem in boys and girls, and in boys a significant decrease in daily steps was found 3 years later. Strongest predictor to be highly physically active, maintain normal BMI and high self‐esteem 3 years later, i.e., to have a healthy lifestyle, was for girls increased self‐esteem and for boys a decreased BMI.

Conclusion: Consequently, for a healthy lifestyle, promoting physical self‐esteem in girls and weight control in boys is of great importance in early adolescence.
Views of breastfeeding difficulties among drop‐in‐clinic attendees
Authors: Berridge Kirstin , McFadden K. , Abayomi J. , Topping J.
Published: September 2005

Breast‐milk is the optimum form of nutrition for the first 6 months of life. However, breastfeeding rates in the UK are low and static compared to other European countries and those in the North‐west of England in the UK are even lower. Of the women who initiate breastfeeding, many cease in the first month following the birth for reasons that might be avoided. To try and prevent this, UNICEF Baby Friendly Hospital Initiative (BFHI) ‘Ten Steps to Successful Breastfeeding’ state that maternity facilities should foster the development of support groups for breastfeeding women. The aim of the present study was to describe breastfeeding difficulties reported by women who attended the infant feeding clinic at a Women's Hospital in the North‐west of England. During the study period, the clinic was attended mainly by primiparous mothers who were educated beyond 18 years of age and of higher socio‐economic status. They presented with a variety of problems including baby not latching on, concerns about baby's weight gain/loss, sore nipples and advice about expressing milk in preparation for return to work. The women highlighted the importance of meeting other mothers and having someone to talk to who understood what they were going through. Inconsistent information/lack of detailed knowledge from health professionals was cited as contributing to breastfeeding difficulties. A number of women reported that expert hands‐on, one‐to‐one support, was invaluable and many felt they were able to continue breastfeeding but without the support, they may have given up.
Kinetic mechanism for p38 MAP kinase α
Authors: Szafranska Anna E. , Dalby Kevin N.
Published: September 2005

p38 Mitogen‐activated protein kinase alpha (p38 MAPKα) is a member of the MAPK family. It is activated by cellular stresses and has a number of cellular substrates whose coordinated regulation mediates inflammatory responses. In addition, it is a useful anti‐inflammatory drug target that has a high specificity for Ser‐Pro or Thr‐Pro motifs in proteins and contains a number of transcription factors as well as protein kinases in its catalog of known substrates. Fundamental to signal transduction research is the understanding of the kinetic mechanisms of protein kinases and other protein modifying enzymes. To achieve this end, because peptides often make only a subset of the full range of interactions made by proteins, protein substrates must be utilized to fully elucidate kinetic mechanisms. We show using an untagged highly active form of p38 MAPKα, expressed and purified from Escherichia coli[Szafranska AE, Luo X & Dalby KN (2005) Anal Biochem336, 1–10) that at pH 7.5, 10 mm Mg2+ and 27 °C p38 MAPKα phosphorylates ATF2Δ115 through a partial rapid‐equilibrium random‐order ternary‐complex mechanism. This mechanism is supported by a combination of steady‐state substrate and inhibition kinetics, as well as microcalorimetry and published structural studies. The steady‐state kinetic experiments suggest that magnesium adenosine triphosphate (MgATP), adenylyl (β,γ‐methylene) diphosphonic acid (MgAMP‐PCP) and magnesium adenosine diphosphate (MgADP) bind p38 MAPKα with dissociation constants of KA = 360 µm, KI = 240 µm, and KI > 2000 µm, respectively. Calorimetry experiments suggest that MgAMP‐PCP and MgADP bind the p38 MAPKα–ATF2Δ115 binary complex slightly more tightly than they do the free enzyme, with a dissociation constant of Kd ≈ 70 µm. Interestingly, MgAMP‐PCP exhibits a mixed inhibition pattern with respect to ATF2Δ115, whereas MgADP exhibits an uncompetitive‐like pattern. This discrepancy occurs because MgADP, unlike MgAMP‐PCP, binds the free enzyme weakly. Intriguingly, no inhibition by 2 mm adenine or 2 mm MgAMP was detected, suggesting that the presence of a β‐phosphate is essential for significant binding of an ATP analog to the enzyme. Surprisingly, we found that inhibition by the well‐known p38 MAPKα inhibitor SB 203580 does not follow classical linear inhibition kinetics at concentrations > 100 nm, as previously suggested, demonstrating that caution must be used when interpreting kinetic experiments using this inhibitor.
Interpopulation variation in the prevalence and intensity of parasitic mite infection in the land snailArianta arbustorum
Authors: Baur Anette , Baur Bruno
Published: September 2005

Abstract.The parasitic miteRiccardoella limacumsucks blood in the lung of its host, the land snailArianta arbustorum. The infection of various host populations was examined in Switzerland. In a lowland snail population, prevalence of infection did not vary among seasons. However, intensity of mite infection in dissected individuals ofA. arbustorumwas high in autumn, but low in winter and spring when ≤100 mite eggs were found attached to the lung epithelium. A novel, non‐invasive parasite screening method was used to estimate the number of mites on living host snails. An analysis of repeatability revealed that 92.9% of the snails were correctly classified as infected or non‐infected with this non‐invasive method. Prevalence of mite infection was examined in 997 adults ofA. arbustorumfrom 11 natural populations distributed over an altitudinal gradient ranging 335–2360 m. No infected snails were found in 7 populations, while in the remaining 4 populations the prevalence of mite infection ranged 45.8–77.8%. Intensity of infection also differed among the 4 host populations. No geographic pattern in prevalence of infection was found. However, parasitic mites did not occur in snail populations situated at elevations of 1290 m or higher. A possible explanation for this finding could be that the host's hibernation period may be too long at high elevations for mites and their eggs to survive. At low elevations, other factors may affect the presence ofR. limacumin the lung ofA. arbustorum.
Biology and functional morphology of a new species of endolithic Bryopa (Bivalvia: Anomalodesmata: Clavagelloidea) from Japan and a comparison with fossil species of Stirpulina and other Clavagellidae
Authors: Morton Brian
Published: September 2005

Abstract. A new species of Clavagellidae, Bryopa aligamenta, from Okinawa, Japan, is described. The species is endolithic in living corals, with the left valve cemented to the crypt wall, as in all clavagellids. The free right valve exhibits an unusual growth pattern, with commarginal lines seemingly arising from the posterior valve margin and extending towards the anterior. This results from: (i) progressive anterior erosion of the umbones, probably as a consequence of the boring process; (ii) the apparent migration posteriorly, as the umbones are eroded, of the dorso‐ventral growth axis of the shell; and (iii) enhanced posterior inter‐commarginal growth. Unlike other clavagellid genera and species, however, there is no discernible primary ligament, at least in the adult. It is possible, however, that if a juvenile ligament were present (as in B. lata), it too would be lost as a consequence of antero‐dorsal erosion during boring. To retain valve alignment in the absence of a primary ligament, and possibly upon reaching an adult size, the mantle lays down alternating layers of calcium carbonate and proteinaceous periostracum onto the interior surface of the shell to thicken it, most noticeably marginally and, especially, posteriorly. The two valves are united dorsally, therefore, by thin layers of periostracum that probably exert a minimal opening force. B. aligamenta is, however, further characterised by large adductor, pallial, and siphonal retractor muscles so that the entire animal is encased tightly within an internally strengthened shell within a crypt. Movement must be minimal, blood being pumped into pallial haemocoels to push open the valves and extend the siphons. Despite a suggestion to the contrary, Bryopa is retained in the Clavagellidae, its unusual growth processes resulting from an endolithic life style within living corals.

The fossil clavagellid Stirpulina bacillus, from the Pliocene/Pleistocene of Palermo, Sicily, Italy, was, unlike Bryopa aligamenta and other clavagellids, endobenthic, with a long adventitious tube and anterior watering pot superficially similar to species of Penicillidae, another family of the Clavagelloidea. Furthermore, as in all clavagellids only the left valve is fused into the fabric of the tube, the right being free within it. In all penicillids, both valves are fused into the fabric of their tubes. The watering pots of the fossil S. coronata, S. vicentina, and S. bacillus, moreover, are formed in a different manner to that of penicillids, by progressive encasement of the right valve inside the tube. In penicillids, the tube is secreted in a single event from the general mantle surface and the incorporation of both valves into its fabric. The constituent genera of the Clavagellidae thus constitute an example of parallel evolution with members of the Penicillidae.
Desiccation resistance in megalopae of the terrestrial hermit crabCoenobita compressus:water loss and the role of the shell
Authors: Brodie Renae J.
Published: September 2005

Abstract.The terrestrial hermit crabCoenobita compressusH. MilneEdwardsundergoes larval development in the sea and then moves to land as a megalopa, where it metamorphoses and remains for the rest of its life. As a small organism (generally <3 mg), in a body adapted for pelagic life, the megalopa must avoid desiccating in air to make a successful sea‐to‐land transition. In this study, I measured rates of water loss in 1 to 26‐day‐old megalopae without mollusk shells to determine if there is an improvement in desiccation resistance with age. I also exposed 26‐day‐old megalopae with or without shells to different relative‐humidity conditions for 1 h to determine if shells worn by megalopae allow them to function in air that is not fully saturated. Megalopae without shells did not survive exposure to a relative humidity (RH) of less than 99%, while those with shells survived 52% RH. Older megalopae lost water more slowly than younger ones. However, the amount of body water explained more of the variation in water‐loss rate than age; individuals with smaller body‐water masses showed lower rates of absolute water loss. Though megalopae ofC. compressusbecome less water permeable as they approach metamorphosis on land, most of their ability to avoid desiccation comes from the shell. Shell‐wearing can be considered a pre‐adaptation to a terrestrial life‐style because shell‐wearing behavior predates land invasion in hermit crabs, and desiccation‐proofing in air is a novel function for shells.
ANALYSIS OF BUTYLATED HYDROXYANISOLE (BHA) IN RBD PALM OIL AND RBD PALM OLEIN USING PARTIAL LEAST SQUARES BASED ON FTIR SPECTROSCOPY
Authors: AMMAWATH W. , CHE MAN Y.B. , BAHARIN B.S. , ABDUL RAHMAN R.B.
Published: September 2005

A rapid method to determine butylated hydroxyanisole (BHA) in refined bleached and deodorized (RBD) palm oil and RBD palm olein was developed. The two sets of 50 stripped oils of RBD palm olein and RBD palm oil were spiked with known amounts of BHA concentrations up to 300 mg/kg (ppm) for calibration samples. The “leave‐one‐out” cross‐validation procedure was used to verify the calibration model. Partial least squares (PLS) calibration models for predicting BHA were developed by using the Fourier transform infrared (FTIR) spectroscopy spectral regions from 3486 to 3140 cm

−1

and 1140 to 898 cm

−1

. The accuracy of the method was comparable to that of the high‐performance liquid chromatography (HPLC) , with coefficients of determination (R2) of 0.9939 from calibration samples of RBD palm olein and an R2of 0.9884 for RBD palm oil samples. The results indicate that FTIR in conjunction with PLS is a useful analytical tool for simple and rapid quantitation of BHA in RBD palm oil and RBD palm olein for routine analysis.
QUANTIFICATION OF FREE FATTY ACIDS AND FLAVOR CHARACTERISTICS OF KASAR CHEESES
Authors: GÜLER ZEHRA
Published: September 2005

Thirty commercial Kasar cheeses were analyzed for their free fatty acids (FFAs) and gross composition as well as flavor profiles. The flavor notes and chemical parameters were grouped by factor analyses and correlated. The predominant free fatty acids in Kasar cheeses were palmitic (C

16:0

) , oleic (C18:1 ), myristic (C14:0 ) and stearic (C18:0 ) acids. Factor analysis showed that the last group of FFA consisted of butyric, caprylic, capric and palmitic acids. The Kasar cheeses were mainly described by panelists as pungent, sour and rancid as well as having an animal‐like flavor. Butyric, caproic, caprylic, capric and lauric acids exhibited these flavors notes and were also statistically correlated with flavor (taste‐odor) (P < 0.05). The desirable‐flavored Kasar cheeses had intermediate concentrations (mg/kg cheese) of individual FFA: 665 for butyric acid, 398 for caproic acid, 254 for caprylic acid, 476 for capric acid, 688 for lauric acid, 2153 for myristic acid, 5559 for palmitic acid, 1703 for stearic acid, 3701 for oleic acid and 15,597 for total FFA.
PHYSICOCHEMICAL CHARACTERISTICS OF BINARY MIXTURES OF HYDROGENATED PALM KERNEL OIL AND GOAT MILK FAT
Authors: RAMLI NAZARUDDIN , SAID MAMOT , LOON NEOH TZE
Published: September 2005

The changes in physicochemical characteristics of fat blends containing hydrogenated palm kernel oil (HPKO) and goat milk fat (GMF), before and after chemical interesterification using sodium methoxide as catalyst, was evaluated. HPKO : GMF blends were prepared in six ratios: 100:0, 80:20, 60:40, 40:60, 20:80 and 0:100 (w/w). Melting characteristics were studied by differential scanning calorimetry. Peak melting temperatures (Tp) of noninteresterified blends decreased as the percentage of GMF increased. Generally, the interesterified blends showed lower Tpvalues compared to the noninteresterified blends at their respective blending ratios. Decrease in melting enthalpy (Ep) occurred with the increase in percentage GMF in the blends for both the noninteresterified and interesterified blends. Interesterified blends had greater Epvalues than those of the noninteresterified blends at respective ratios. Results from X‐ray diffraction analysis showed that all blends possessed a β′ polymorph. HPKO : GMF (0:100) was the only blend in which the presence of both β′ and β polymorphs was detected. Chemical interesterification had no effect on polymorphic crystal behavior. Based on solid fat content (SFC) results, eutectic effect did not occur in all HPKO : GMF blends studied. It was shown that the percentage of SFC decreased as percentage of GMF increased. Decrease in percentage SFC of blends was brought about by interesterification. The HPKO : GMF (100:0) blend had the highest percentage of free fatty acid followed by HPKO : GMF (0:100). Interesterification caused a 2‐ to 3‐fold increase in the percentage of free fatty acids compared to noninteresterified blends. Iodine values of the blends increased with an increase in GMF proportion. A rapid increase in iodine was observed in blends containing 0–20% GMF. Interesterification did not have any effect on the iodine value of fat blends.
THE EFFECT OF INTESTINAL MICROFLORA ON ANTIOXIDANT ACTIVITY OF APPLE JUICE
Authors: BIEDRZYCKA E. , BIELECKA M. , AMAROWICZ R.
Published: September 2005

The influence of intestinal microflora on the antioxidant activity of apple juice was assessed using the scavenging of DPPH radical. The culture medium contained 20% of laboratory‐made apple juice of Idaret cultivar and 0.2% of sodium citrate neutralizing solution. Thirty‐hour anaerobic cultures were characterized by comparable acidity and bacterial profiles of the genera determined, regardless of pure strain coculture or fresh fecal inoculum used. Apple juice showed the highest DPPH scavenging capacity of 59.9%, which was significantly reduced upon fermentation of fecal bacteria to 37.4%, or pure strain coculture to 33.4%. In the 24‐h anaerobic monocultures, the degree of DPPH scavenging was differentiated: Lactobacillus 21.4–30.2%, Bifidobacterium 28.4–51.4%, Escherichia 50.9% and Enterococcus 35.9–37.9%. The degree of DPPH scavenging was highly positively correlated (0.824) with pH, and highly/moderately negatively correlated (−0.660) with bacterial count. The results indicate reduction of antioxidant activity of apple juice as influenced by intensive bacterial growth, irrespective of species or strain used.
Intestinal effects of long‐lasting spermine ingestion by suckling rats
Authors: Deloyer Patricia , Peulen Olivier , Dandrifosse Guy
Published: September 2005

Spermine ingestion induces the precocious maturation of the small intestine in suckling rats. Previous observations suggest that spermine‐induced intestinal maturation is a two‐step phenomenon. The first step is the elimination of immature enterocytes (4–10 h post spermine ingestion) and the second step is the replacement of previous immature cells by adult‐type enterocytes (2–3 days post initial spermine administration). The spermine‐induced maturation is reversible when spermine administration is stopped. This work was undertaken in order to check whether the extension of polyamine administration (for 3–7 days) after the appearance of spermine‐induced maturation can retain the mature state of the small intestine. Our results indicate that extension of spermine administration does not prevent some parameters (sucrase and maltase specific activities) reverting to a typical ‘immature’ value while others remain at a typical ‘mature’ level (mucosal weight and lactase specific activity). Our results show that there are at least two different mechanisms in required for the control of spermine‐induced maturation of the small intestine.
Mode of Action of the
Bordetella
BvgA Protein: Transcriptional Activation and Repression of the
Bordetella bronchiseptica bipA
Promoter
Authors: Mishra Meenu , Deora Rajendar
Published: September 2005

The
Bordetella
BvgAS signal transduction system controls the transition among at least three known phenotypic phases (Bvg
+
, Bvg
i
, and Bvg
−
) and the expression of a number of genes which have distinct phase-specific expression profiles. This complex regulation of gene expression along the Bvg signaling continuum is best exemplified by the gene
bipA
, which is expressed at a low level in the Bvg
+
phase, at a maximal level in the Bvg
i
phase, and at undetectable levels in the Bvg
−
phase. The
bipA
promoter has multiple BvgA binding sites which play distinct regulatory roles. We had previously speculated that the expression profile of
bipA
is a consequence of the differential occupancy of the various BvgA binding sites as a result of variation in the levels of phosphorylated BvgA (BvgA-P) inside the cell. In this report, we provide in vitro evidence for this model and show that
bipA
expression is activated at low concentrations of BvgA-P and is repressed at high concentrations. By using independent DNA binding assays, we demonstrate that under activating conditions there is a synergistic effect on the binding of BvgA and RNA polymerase (RNAP), leading to the formation of open complexes at the promoter. We further show that, under in vitro conditions, when
bipA
transcription is minimal, there is competition between the binding of RNAP and BvgA-P to the
bipA
promoter. Our results show that the BvgA binding site IR2 plays a central role in mediating this repression.
Adenylate Cyclase Mutations Rescue the
degP
Temperature-Sensitive Phenotype and Induce the Sigma E and Cpx Extracytoplasmic Stress Regulons in
Escherichia coli
Authors: Strozen Timothy G. , Langen Geoffrey R. , Howard S. Peter
Published: September 2005

Inactivation of the gene encoding the periplasmic protease DegP confers a high-temperature-sensitive phenotype in
Escherichia coli
. We have previously demonstrated that a
degP
mutant of
E. coli
strain CBM (W3110
pldA1
) is not temperature sensitive and showed that this was most likely due to constitutive activation of the sigma E and Cpx extracytoplasmic stress regulons in the parent strain. In this study, further characterization of this strain revealed a previously unknown cryptic mutation that rescued the
degP
temperature-sensitive phenotype by inducing the extracytoplasmic stress regulons. We identified the cryptic mutation as an 11-bp deletion of nucleotides 1884 to 1894 of the adenylate cyclase-encoding
cyaA
gene (
cyaA
Δ
11
). The mechanism in which
cyaA
Δ
11
induces the sigma E and Cpx regulons involves decreased activity of the mutant adenylate cyclase. Addition of exogenous cyclic AMP (cAMP) to the growth medium of a
cyaA
Δ
11
mutant strain that contains a Cpx- and sigma E-inducible
degP
-
lacZ
reporter fusion decreased β-galactosidase expression to levels observed in a
cyaA
+
strain. We also found that a
cyaA
null mutant displayed even higher levels of extracytoplasmic stress regulon activation compared to a
cyaA
Δ
11
mutant. Thus, we conclude that the lowered concentration of cAMP in
cyaA
mutants induces both sigma E and Cpx extracytoplasmic stress regulons and thereby rescues the
degP
temperature-sensitive phenotype.
Complex Transcriptional Control Links NikABCDE-Dependent Nickel Transport with Hydrogenase Expression in
Escherichia coli
Authors: Rowe Jessica L. , Starnes G. Lucas , Chivers Peter T.
Published: September 2005

Escherichia coli
requires nickel under anaerobic growth conditions for the synthesis of catalytically active NiFe hydrogenases. Transcription of the NikABCDE nickel transporter, which is required for NiFe hydrogenase synthesis, was previously shown to be upregulated by FNR (fumarate-nit rate regulator) in the absence of oxygen and repressed by the NikR repressor in the presence of high extracellular nickel levels. We present here a detailed analysis of
nikABCDE
transcriptional regulation and show that it closely correlates with hydrogenase expression levels. We identify a nitrate-dependent mechanism for
nikABCDE
repression that is linked to the NarLX two-component system. NikR is functional under all nickel conditions tested, but its activity is modulated by the total nickel concentration present as well as by one or more components of the hydrogenase assembly pathway. Unexpectedly, NikR function is independent of NikABCDE function, suggesting that NikABCDE is a hydrogenase-specific nickel transporter, consistent with its original identification as a hydrogenase (
hyd
) mutant. Further, the results suggest that the hydrogenase assembly pathway is sequestered within the cell. A second nickel import pathway in
E. coli
is implicated in NikR function.
Purification and Characterization of the N-Terminal Domain of ExeA: a Novel ATPase Involved in the Type II Secretion Pathway of
Aeromonas hydrophila
Authors: Schoenhofen Ian C. , Li Gang , Strozen Timothy G. , Howard S. Peter
Published: September 2005

Aeromonas hydrophila
secretes a number of degradative enzymes and toxins into the external milieu via the type II secretory pathway or secreton. ExeA is an essential component of this system and is necessary for the localization and/or multimerization of the secretin ExeD. ExeA contains two sequence motifs characteristic of the Walker superfamily of ATPases. Previous examination of substitution derivatives altered in these motifs suggested that ATP binding or hydrolysis is required for ExeAB complex formation and subsequent secretion function. To directly examine ExeA function, the N-terminal cytoplasmic domain of ExeA with the addition of a C-terminal hexahistidine tag (cytExeA) was overproduced in
Escherichia coli
and purified by metal chelate affinity and anion-exchange chromatographic techniques. Purified preparations of cytExeA exhibited ATPase activity in the presence of several divalent cations, Mg
2+
being the preferred cation, with an optimum reaction temperature of ∼37 to 42°C and an optimum pH of 7 to 8. cytExeA exhibited an apparent

K
m

for Mg-ATP of 0.22 mM and a
V
max
of 0.72 nmol min
−1
mg
−1
of protein. cytExeA displayed low specificity for nucleoside triphosphate substrates and was significantly inhibited by F-type ATPase inhibitors. Gel filtration analyses of cytExeA, ExeA, and ExeAB indicated that ExeA dimerizes and forms a very large complex with ExeB. These findings support a model whereby ExeAB utilizes energy derived from ATP hydrolysis to facilitate the correct localization and multimerization of the ExeD secretin.
Partial Restoration of Antibacterial Activity of the Protein Encoded by a Cryptic Open Reading Frame (
cyt1Ca
) from
Bacillus thuringiensis
subsp.
israelensis
by Site-Directed Mutagenesis
Authors: Itsko Mark , Manasherob Robert , Zaritsky Arieh
Published: September 2005

Insecticidal crystal proteins of
Bacillus thuringiensis
belong to two unrelated toxin families: receptor-specific Cry toxins against insects and Cyt toxins that lyse a broad range of cells, including bacteria, via direct binding to phospholipids. A new
cyt
-like open reading frame (
cyt1Ca
) encoding a 60-kDa protein, has recently been discovered (C. Berry et al., Appl. Environ. Microbiol.
68:
5082-5095, 2002). Cyt1Ca displays the structure of a two-domain fusion protein: the N-terminal moiety resembles the full-length Cyt toxins, and the C-terminal moiety is similar to the receptor-binding domains of several ricin-like toxins, such as Mtx1. Neither the larvicidal activity of
cyt1Ca
expressed in
Escherichia coli
nor the hemolytic effect of His-tagged purified Cyt1Ca has been observed (R. Manasherob et al., unpublished). This was attributed to five amino acid differences between the sequences of its N-terminal moiety and Cyt1Aa. The 3′ end of
cyt1Ca
was truncated (removing the ricin-binding domain of Cyt1Ca), and six single bases were appropriately changed by site-directed mutagenesis, sequentially replacing the noncharged amino acids by charged ones, according to Cyt1Aa, to form several versions. Expression of these mutated
cyt1Ca
versions caused loss of the colony-forming ability of the corresponding
E. coli
cells to different extents compared with the original gene. In some mutants this antibacterial effect was associated by significant distortion of cell morphology and in others by generation of multiple inclusion bodies spread along the cell envelope. The described deleterious effects of mutated
cyt1Ca
versions against
E. coli
may reflect an evolutionary relationship between Cyt1Aa and Cyt1Ca.
Revisiting the Evolution of
Mycobacterium bovis
Authors: Mostowy Serge , Inwald Jackie , Gordon Steve , Martin Carlos , Warren Rob , Kremer Kristin , Cousins Debby , Behr Marcel A.
Published: September 2005

Though careful consideration has been placed towards genetic characterization of tubercle bacillus isolates causing disease in humans, those causing disease predominantly among wild and domesticated mammals have received less attention. In contrast to
Mycobacterium tuberculosis
, whose host range is largely specific to humans,
M. bovis
and “
M bovis
-like” organisms infect a broad range of animal species beyond their most prominent host in cattle. To determine whether strains of variable genomic content are associated with distinct distributions of disease, the DNA contents of
M. bovis
or
M. bovis
-like isolates from a variety of hosts were investigated via Affymetrix GeneChip. Consistent with previous genomic analysis of the
M. tuberculosis
complex (MTC), large sequence polymorphisms of putative diagnostic and biological consequence were able to unambiguously distinguish interrogated isolates. The distribution of deleted regions indicates organisms genomically removed from
M. bovis
and also points to structured genomic variability within
M. bovis
. Certain genomic profiles spanned a variety of hosts but were clustered by geography, while others associated primarily with host type. In contrast to the prevailing assumption that
M. bovis
has broad host capacity, genomic profiles suggest that distinct MTC lineages differentially infect a variety of mammals. From this, a phylogenetic stratification of genotypes offers a predictive framework upon which to base future genetic and phenotypic studies of the MTC.
Homologies and Divergences in the Transcription Regulatory System of Two RelatedBacillus subtilisPhages
Authors: Pérez-Lago Laura , Salas Margarita , Camacho Ana
Published: September 2005

Transcription regulation relies on the molecular interplay between the RNA polymerase and regulatory factors. Phages of the φ29-like genus encode two regulatory proteins, p4 and p6. In φ29, the switch from early to late transcription is based on the synergistic binding of proteins p4 and p6 to the promoter sequence, resulting in a nucleosome-like structure able to synergize or antagonize the binding of RNAP. We show that a nucleosome-like structure of p4 and p6 is also formed in the related phage Nf and that this structure is responsible for the coordinated control of the early and late promoters. However, in spite of their homologies, the transcriptional regulators are not interchangeable, and only when all of the components of the Nf regulatory system are present is fully active transcriptional regulation of the Nf promoters achieved.