bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maternal Genotype Influences Stress Reactivity of Vasopressin‐Deficient Brattleboro Rats
Authors: Zelena D. , Mergl Z. , Makara G. B. 
Published: November 2003

AbstractThe role of vasopressin, cosecreted with corticotropin‐releasing hormone (CRH), in stress is debated, because both normal as well as reduced adrenocorticotropin hormone (ACTH) rise to an acute challenge has been reported in Brattleboro rats genetically lacking vasopressin (di/di). Because di/di pups could be born either from di/+ (heterozygous) or from di/di mothers, and maternal influence is known to modify adult responsiveness, we investigated whether the influence of maternal genotype could explain the variability. Adult rats from mothers with different genotypes were stressed with 60 min restraint and trunk blood was collected for measuring hormone content by radioimmunoassay at the end of stress. All offspring of di/+ mothers had similar ACTH responses to restraint, while the di/di rats born to, and raised by di/di mothers showed reduced ACTH reactivity to restraint. The di/di rats showed elevated water turnover and required a daily cage cleaning every day, which meant frequent handling. To offset the role of handling, all rats had daily cage cleaning in the next series, but the results were the same as in the first series. To investigate whether lactation, the behaviour of the mother or some other factor during the pregnancy is responsible for the differences, pups from di/+ dams were raised by di/di foster mothers and vice versa. We found that the genotype of parental mother is more important than that of the foster mother. The corticosterone and prolactin elevation normally seen after acute stress was unchanged by family history, maternal or personal genotype. Furthermore, in studies with mutant animals, the rearing conditions should be controlled by the experimenter. In experiments with Brattleboro rats, the use of homozygous and heterozygous rats from the same litters of di/+ dams and di/di males is recommended. Our results suggest that vasopressin is not indispensable for ACTH release, and that the di/di genotype of the parental mother can decrease the stress reactivity of the di/di Brattleboro rats.
Adenosine A2A Receptor Gene Disruption Provokes Marked Changes in Melanocortin Content and Pro‐Opiomelanocortin Gene Expression
Authors: Jégou S. , Yacoubi M. El , Mounien L. , Ledent C. , Parmentier M. , Costentin J. , Vaugeois J. ‐M. , Vaudry H. 
Published: November 2003

AbstractA2A receptor knockout (A2AR−/−) mice are more anxious and aggressive, and exhibit reduced exploratory activity than their wild‐type littermates (A2AR+/+). Because α‐melanocyte‐stimulating hormone (α‐MSH) influences anxiety, aggressiveness and motor activity, we investigated the effect of A2AR gene disruption on α‐MSH content in discrete brain regions and pro‐opiomelanocortin (POMC) expression in the hypothalamus and pituitary. No modification in α‐MSH content was observed in the hypothalamus and medulla oblongata where POMC‐expressing perikarya are located. In the arcuate nucleus of the hypothalamus, POMC mRNA levels were not affected by A2AR disruption. Conversely, in A2AR−/− mice, a significant increase in α‐MSH content was observed in the amygdala and cerebral cortex, two regions that are innervated by POMC terminals. In the pars intermedia of the pituitary, A2AR disruption provoked a significant reduction of POMC mRNA expression associated with a decrease in α‐MSH content. By contrast, in the anterior lobe of the pituitary, a substantial increase in POMC mRNA and adrenocorticotropin hormone concentrations was observed, and plasma corticosterone concentration was significantly higher in A2AR−/− mice, revealing hyperactivity of their pituitary‐adrenocortical axis. Together, these results suggest that adenosine, acting through A2A receptors, may modulate the release of α‐MSH in the cerebral cortex and amygdala. The data also indicate that A2A receptors are involved in the control of POMC gene expression and biosynthesis of POMC‐derived peptides in pituitary melanotrophs and corticotrophs.
Involvement of Ca2+‐calmodulin in Cd2+ toxicity during the early phases of radish (Raphanus sativus L.) seed germination
Authors: RIVETTA A. , NEGRINI N. , COCUCCI M. 
Published: November 2003

ABSTRACTThe toxicity of Cd2+in vivo during the early phases of radish (Raphanus sativus L.) seed germination and the in vitro Cd2+ effect on radish calmodulin (CaM) were studied. Cd2+ was taken up in the embryo axes of radish seeds; the increase in fresh weight of embryo axes after 24 h of incubation was inhibited significantly in the presence of 10 mmol m−3 Cd2+ in the external medium, when the Cd2+ content in the embryo axes was c. 1.1 μmol g−1 FW. The reabsorption of K+, which characterizes germination, was inhibited by Cd2+, suggesting that Cd2+ affected metabolic reactivation. The slight effect of Cd2+ on the transmembrane electric potential of the cortical cells of the embryo axes excluded a generalized toxicity of Cd2+ at the plasma membrane level. After 24 h of incubation, Cd2+ induced no increase in total acid‐soluble thiols and Cd2+‐binding peptides able to reduce Cd2+ toxicity. Ca2+ added to the incubation medium partially reversed the Cd2+‐induced inhibition of the increase in fresh weight of embryo axes and concomitantly reduced Cd2+ uptake. Equilibrium dialysis experiments indicated that Cd2+ bound to CaM and competed with Ca2+ in this binding. Cd2+ inhibited the activation of Ca2+‐CaM‐dependent calf‐brain phosphodiesterase, inhibiting the Ca2+‐CaM active complex. Cd2+ reduced the binding of CaM to the Ca2+‐CaM binding enzymes present in the soluble fraction of the embryo axes of radish seeds. The possibility that Cd2+ toxicity in radish seed germination is mediated by the action of Cd2+ on Ca2+‐CaM is discussed in relation to the in vivo and in vitro effects of Cd2+.
Simple scaling of photosynthesis from leaves to canopies without the errors of big‐leaf models
Authors: DE PURY D. G. G. , FARQUHAR G. D. 
Published: November 2003

ABSTRACTIn big‐leaf models of canopy photosynthesis, the Rubisco activity per unit ground area is taken as the sum of activities per unit leaf area within the canopy, and electron transport capacity is similarly summed. Such models overestimate rates of photosynthesis and require empirical curvature factors in the response to irradiance. We show that, with any distribution of leaf nitrogen within the canopy (including optimal), the required curvature factors are not constant but vary with canopy leaf area index and leaf nitrogen content. We further show that the underlying reason is the difference between the time‐averaged and instantaneous distributions of absorbed irradiance, caused by penetration of sunflecks and the range of leaf angles in canopies.These errors are avoided in models that treat the canopy in terms of a number of layers – the multi‐layer models. We present an alternative to the multi‐layer model: by separately integrating the sunlit and shaded leaf fractions of the canopy, a single layered sun/shade model is obtained, which is as accurate and simpler. The model is a scaled version of a leaf model as distinct from an integrative approach.
The effect of temperature differences between porometer head and leaf surface on stomatal conductance measurements
Authors: VERHOEF A. 
Published: November 2003

ABSTRACTIt is generally known that instantaneous values of leaf conductance as measured with a dynamic porometer need to be corrected for the temperature difference, ΔT, between the porometer cup and the sampled leaf. Leaf conductances, obtained with a Delta‐T AP4 dynamic porometer, with and without correction for ΔT are compared for a bush species (Guiera senegalensis) and two forb species (Jacquemontia tamnifolia and Mitracarpus scaber). With temperature differences predominantly varying within the ±2.5 °C recommended by the manufacturer, it appears that the differences between uncorrected and corrected conductances are very large, up to 100% on average, especially for the two forbs. Furthermore, it is shown that, using the Mitracarpus data, a relatively small error of ±0.5 °C in ΔT can cause a difference of 25–50% in the final conductance value, in particular for the high conductance range. An error of ±0.5 °C may easily occur: the accuracy of ΔT as measured by the thermistors in the porometer is 0.2 °C and the temperature variation within a leaf can be much larger. This result will have implications for upscaling of leaf conductances to canopy values or may explain why upscaled values appear not to correspond with down‐scaled values, obtained from eddy correlation measurements and an inverted canopy transpiration model.
Salinity and drought tolerance of mannitol‐accumulating transgenic tobacco
Authors: KARAKAS B. , OZIAS‐AKINS P. , STUSHNOFF C. , SUEFFERHELD M. , RIEGER M. 
Published: November 2003

ABSTRACTTobacco plants (Nicotiana tabacumL.) were transformed with a mannitol‐1‐phosphate dehydrogenase gene resulting in mannitol accumulation. Experiments were conducted to determine whether mannitol provides salt and/or drought stress protection through osmotic adjustment. Non‐stressed transgenic plants were 20–25% smaller than non‐stressed, non‐transformed (wild‐type) plants in both salinity and drought experiments. However, salt stress reduced dry weight in wild‐type plants by 44%, but did not reduce the dry weight of transgenic plants. Transgenic plants adjusted osmotically by 0.57 MPa, whereas wild‐type plants did not adjust osmotically in response to salt stress. Calculations of solute contribution to osmotic adjustment showed that mannitol contributed only 0‐003‐0‐004 MPa to the 0.2 MPa difference in full turgor osmotic potential (πo) between salt‐stressed transgenic and wild‐type plants. Assuming a cytoplasmic location for mannitol and that the cytoplasm constituted 5% of the total water volume, mannitol accounted for only 30–40% of the change in πoof the cytoplasm. Inositol, a naturally occurring polyol in tobacco, accumulated in response to salt stress in both transgenic and wild‐type plants, and was 3‐fold more abundant than mannitol in transgenic plants.Drought stress reduced the leaf relative water content, leaf expansion, and dry weight of transgenic and wild‐type plants. However, πowas not significantly reduced by drought stress in transgenic or wild‐type plants, despite an increase in non‐structural carbohydrates and mannitol in droughted plants. We conclude that (1) mannitol was a relatively minor osmolyte in transgenic tobacco, but may have indirectly enhanced osmotic adjustment and salt tolerance; (2) inositol cannot substitute for mannitol in this role; (3) slower growth of the transgenic plants, and not the presence of mannitolper se, may have been the cause of greater salt tolerance, and (4) mannitol accumulation was enhanced by drought stress but did not affect πoor drought tolerance.
Prolegomenon for Chronic Lymphocytic Leukaemia
Authors: Vitale B. , Martinis M. , Antica M. , Kušić B. , Rabatić S. , Gagro A. , Kušec R. , Jakšić B. 
Published: November 2003

AbstractChronic lymphocytic leukaemia (CLL) is a unique lymphoproliferative disorder that scarcely occurs under the age of 40; thereafter the incidence of CLL increases exponentially with age. CLL is characterized by progressive expansion of malignant CD5+ME+ B‐cell clone accompanied by a myriad of cellular and humoral immune defects. Each of them might be linked to different clinically manifested complications such as increasing rate of infections, autoimmune disorders and disturbed immune surveillance against tumour cells. We assume that CLL occurs as a consequence of age‐dependent, genetically related functional restrictions of the thymic microenvironment in supporting common lymphoid progenitor cells (CD5+ME+CD4–CD8–) to differentiate into mature T‐cell and B‐cell descendants. In conjunction with genetic abnormalities developing in B‐cell progenitors, presumably expressing P glycoprotein (Pgp+), we postulate that developmentally altered T‐cell descendants, along with quantitative imbalance among CD4+, their subsets and CD8+ lymphocytes in the peripheral blood, play an important additional role in facilitating the malignant B‐cell clone emergence and in modulating the CLL clinical evolution. Namely, imbalance of any of T‐cell‐mediated cell interactive homeostatic mechanisms accompanied by imbalance in the production of various cytokines might in CLL influence leukaemic B‐cell growth by deregulating inducer (c‐myc and p53) and/or suppressor (bcl‐2 and mutant p53) oncogenes responsible for the promotion or suppression of B‐cell mitogenesis that may in turn further contribute to their impaired differentiation and/or differentiation arrest. In conclusion, CLL might be interpreted as a primary immunodeficiency syndrome developing in elderly population due to gradually evolving restriction of genetically controlled programs in the thymic microenvironment responsible for irregular maturation of common lymphoid progenitor cells that constitutively express CD5 antigen and ME receptor into T‐cell and B‐cell descendants.
Development of Immunoglobulin A in Infancy and Childhood
Authors: Weemaes C. , Klasen I. , Göertz J. , Beldhuis‐Valkis M. , Olafsson O. , Haraldsson A. 
Published: November 2003

AbstractSerum and salivary concentrations of immunoglobulin A1 (IgA1) and IgA2 were studied in 105 Icelandic children aged 0–12 years. Serum concentrations of both IgA1 and IgA2 increased slightly (P < 0.001) during childhood. The salivary IgA1/IgA2 ratio tended to decrease during the same period; this trend is less apparent when omitting the youngest children. The salivary IgA1 and IgA2 output could be high, even in children with low levels of serum IgA. Only polymeric IgA was found in whole saliva. Interestingly, in serum, most IgA1 and IgA2 were polymeric during infancy. The proportion of polymeric IgA decreased, when the concentration of IgA increased. The polymeric form of IgA might provide the infant with better protection against invading microorganisms by activation of the innate immune mechanisms.
Kinetics of Cytokine Gene Expression in Human CD4+ and CD8+ T‐Lymphocyte Subsets Using Quantitative Real‐Time PCR
Authors: Abdalla A. O. , Kiaii S. , Hansson L. , Rossmann E. D. , Jeddi‐Tehrani M. , Shokri F. , Österborg A. , Mellstedt H. , Rabbani H. 
Published: November 2003

AbstractThe time kinetics of five cytokines [interleukin‐2 (IL‐2), IL‐5, interferon‐γ (IFN‐γ), granulocyte macrophage‐colony stimulating factor (GM‐CSF) and tumour necrosis factor‐α (TNF‐α)] and one cytotoxic effector protein (granzyme B) was analysed by real‐time quantitative polymerase chain reaction (PCR) following in vitro stimulation of human CD4 and CD8 T lymphocytes. Two stimuli were used, a mitogen [phytohemagglutinin (PHA)] and a recall antigen [purified protein derivative (PPD)]. The pattern of cytokine mRNA expression was found to be dependent on the T‐cell subset and stimulus used. A wide interindividual variability in the cytokine gene expression pattern was demonstrated. Two expression patterns were observed. A bell‐shaped expression profile was seen for most cytokines upon PHA activation in both subsets and PPD‐activated CD4 T cells, whereas a biphasic/multiphasic expression pattern was noted in CD8 T cells upon PPD stimulation. For most cytokines, the time to induction was within 30 min of activation, and maximum accumulation seemed to be obtained after 4–8 h of activation. A sustained high level could, however, be noticed for up to 24 h. Granzyme B gene expression was also induced within 30 min of activation but showed a continuous gradual increase and late maximal accumulation (48–72 h). The findings of the present study are of importance when designing studies using the cytokine gene expression profile as a marker for antigen‐specific T lymphocytes. It might be recommended that cytokine gene expression (IL‐2, IL‐5 and IFN‐γ) should be measured after 4–8 h of specific activation but also up to 24 h of stimulation is acceptable. Granzyme B should preferentially be measured after 48–72 h of activation.
Extensive xanthelasma associated with anaplastic large cell lymphoma and hyperimmunoglobulin E syndrome
Authors: Lee Mi‐Woo , Choi Jee‐Ho , Sung Kyung‐Jeh , Moon Kee‐Chan , Koh Jai‐Kyoung 
Published: November 2003

A 57‐year‐old woman presented with a 6‐month history of an extensively spreading, yellowish patch on the periorbital areas and cheeks. A diagnosis of hyperimmunoglobulin E syndrome had been made at the age of 22 years on the basis of an eczematous eruption, recurrent furunculosis, and a persistently elevated immunoglobulin E (IgE) level. Her past medical history revealed that she had suffered from numerous recurrent bouts of chronic sinusitis, otitis media, oral candidiasis, orbital cellulitis, acne rosacea, and pneumonia caused by cytomegalovirus since her twenties. In addition, 1 year ago, anaplastic large cell lymphoma of the cervical lymph node (stage IIIb) developed, and she received six cycles of cyclophosphamide–doxorubicin–vincristine–prednisolone (CHOP) chemotherapy with partial remission. None of her family had any of these problems. Cutaneous examination showed extensive, symmetric, noninfiltrated macular areas of distinct yellow discoloration around the eyes and on both cheeks (Fig. 1). There were also erythematous papulonodular eruptions on the nose and both cheeks, which were thought to be acne rosacea. Laboratory findings were normal, except for an elevated IgE level (8157 IU/mL). Serum concentrations of IgG, IgA, and IgM were normal. Serum complement levels were normal, as evidenced by normal C3, C4, and CH50. Although she had a previous history of a decreased level (12%) of nitroblue tetrazolium (NBT) test (control, 53%), NBT test at our institute was normal. Neutrophil function tests, including neutrophil chemotaxis, neutrophil phagocytosis, neutrophil respiratory burst, and neutrophil microbial killing test, by flow cytometry, showed normal results. The serum lipid levels, including total cholesterol, triglyceride, low‐density lipoprotein‐cholesterol, and high‐density lipoprotein‐cholesterol, were normal. Serum lipoprotein electrophoresis was normal. A biopsy specimen revealed scattered foamy cells throughout the dermis. The larger clusters of foamy cells tended to group around the blood vessels of the dermis (Fig. 2).Extensively distributed, yellowish, flat xanthelasma on the faceimageClusters of foamy cells around the blood vessels of the dermis (hematoxylin and eosin, ×400)image
Treatment of pediculosis capitis with thiabendazole: a pilot study
Authors: Namazi Mohammad Reza 
Published: November 2003

AbstractBackground  Despite the improvement of health standards, head lice infestation remains a problem worldwide. In addition, there is increasing evidence that head lice are becoming resistant to common pediculocides.Aim  To test the potential effectiveness of thiabendazole, a potent and broad‐spectrum antiparasitic and scabicidal agent, for the treatment of pediculosis capitis.Methods  Twenty‐three female patients, aged 7–12 years, who had active head lice infestation, were treated with oral thiabendazole, 20 mg/kg twice daily for 1 day, with repeat treatment after 10 days.Results  On the 11th day, meticulous hair examination showed that 21 patients had responded to treatment [91%; 95% confidence interval (CI), 71–98%], with 14 showing complete responsiveness (61%; 95% CI, 40–78%). The only adverse reactions observed were nausea and mild dizziness, which occurred in four patients, three of whom took the drug on an empty stomach.Conclusions  Thiabendazole may be a promising treatment for head lice infestation. The primary action of this drug seems to be the inhibition of parasite microtubule polymerization by binding to β‐tubulin. In addition, thiabendazole may interfere with the synaptic transmission of lice through its probable cholinergic effect. As pediculosis capitis is a very communicable disease, the unresponsiveness to thiabendazole could largely be attributed to new infestations during the drug‐free interval. Therefore, massive and simultaneous rather than individual and isolated treatments should be used to achieve the epidemiologic control of this ectoparasitosis. As this is a preliminary study, the performance of double‐blind, randomized controlled trials on this subject is warranted. Thiabendazole, either alone or in combination with other agents, may prove to be of particular use in areas in which head lice show resistance to common pediculocides.
Safety and efficacy of 4% hydroquinone combined with 10% glycolic acid, antioxidants, and sunscreen in the treatment of melasma
Authors: Guevara Ian L. , Pandya Amit G. 
Published: November 2003

AbstractBackground   Melasma, also known as mask of pregnancy, is a common, acquired hypermelanosis seen in women with Fitzpatrick skin types II–V, and is often recalcitrant to treatment with depigmentation agents. Glycolic acid has been added to hydroquinone formulations in the past to enhance their depigmentation effects, but may cause irritation, leading to postinflammatory hyperpigmentation.Aim   To assess the safety and efficacy of a cream containing 4% hydroquinone, 10% buffered glycolic acid, vitamins C and E, and sunscreen (Glyquin, ICN Pharmaceuticals, Costa Mesa, USA) vs. a cream containing sunscreen alone in the depigmentation of epidermal melasma of the face.Methods   Thirty‐nine Hispanic women, Fitzpatrick skin types III–V, with bilateral epidermal melasma were enrolled in a randomized controlled trial lasting 12 weeks. Patients underwent twice‐daily full‐face application with the study cream or with the cream containing sunscreen only. Changes in pigmentation were measured using a mexameter, the melasma area and severity index (MASI), and a global evaluation by the patient and blind investigator. Safety evaluations were performed at each follow‐up visit.Results   Thirty‐five patients completed the trial. Irritation was more common with the study cream, but resolved with temporary cessation of cream application and the addition of moisturizers. Mexameter results demonstrated a significant decrease in the degree of pigmentation using the study cream compared with the cream containing sunscreen alone (P < 0.0001). Fifteen of 20 patients (75%) using the study cream improved, whereas only two of 15 patients (13%) improved using sunscreen alone.Conclusions   A cream containing 4% hydroquinone, 10% buffered glycolic acid, vitamins C and E, and sunscreen is safe and effective in the treatment of melasma.