Regional differences in thermoregulation between two European butterfly communities.

Understanding how different organisms cope with changing temperatures is vital for predicting future species' distributions and highlighting those at risk from climate change. As ectotherms, butterflies are sensitive to temperature changes, but the factors affecting butterfly thermoregulation are not fully understood. We investigated which factors influence thermoregulatory ability in a subset of the Mediterranean butterfly community. We measured adult thoracic temperature and environmental temperature (787 butterflies; 23 species) and compared buffering ability (defined as the ability to maintain a consistent body temperature across a range of air temperatures) and buffering mechanisms to previously published results from Great Britain. Finally, we tested whether thermoregulatory ability could explain species' demographic trends in Catalonia. The sampled sites in each region differ climatically, with higher temperatures and solar radiation but lower wind speeds in the Catalan sites. Both butterfly communities show nonlinear responses to temperature, suggesting a change in behaviour from heat-seeking to heat avoidance at approximately 22°C. However, the communities differ in the use of buffering mechanisms, with British populations depending more on microclimates for thermoregulation compared to Catalan populations. Contrary to the results from British populations, we did not find a relationship between region-wide demographic trends and butterfly thermoregulation, which may be due to the interplay between thermoregulation and the habitat changes occurring in each region. Thus, although Catalan butterfly populations seem to be able to thermoregulate successfully at present, evidence of heat avoidance suggests this situation may change in the future.

High-density linkage maps and chromosome level genome assemblies unveil direction and frequency of extensive structural rearrangements in wood white butterflies (Leptidea spp.).

Karyotypes are generally conserved between closely related species and large chromosome rearrangements typically have negative fitness consequences in heterozygotes, potentially driving speciation. In the order Lepidoptera, most investigated species have the ancestral karyotype and gene synteny is often conserved across deep divergence, although examples of extensive genome reshuffling have recently been demonstrated. The genus Leptidea has an unusual level of chromosome variation and rearranged sex chromosomes, but the extent of restructuring across the rest of the genome is so far unknown. To explore the genomes of the wood white (Leptidea) species complex, we generated eight genome assemblies using a combination of 10X linked reads and HiC data, and improved them using linkage maps for two populations of the common wood white (L. sinapis) with distinct karyotypes. Synteny analysis revealed an extensive amount of rearrangements, both compared to the ancestral karyotype and between the Leptidea species, where only one of the three Z chromosomes was conserved across all comparisons. Most restructuring was explained by fissions and fusions, while translocations appear relatively rare. We further detected several examples of segregating rearrangement polymorphisms supporting a highly dynamic genome evolution in this clade. Fusion breakpoints were enriched for LINEs and LTR elements, which suggests that ectopic recombination might be an important driver in the formation of new chromosomes. Our results show that chromosome count alone may conceal the extent of genome restructuring and we propose that the amount of genome evolution in Lepidoptera might still be underestimated due to lack of taxonomic sampling.

General Purpose Transistor Characterized as Dosimetry Sensor of Proton Beams.

A commercial pMOS transistor (MOSFET), 3N163 from Vishay (USA), has been characterized as a low-energy proton beam dosimeter. The top of the samples' housing has been removed to guarantee that protons reached the sensitive area, that is, the silicon die. Irradiations took place at the National Accelerator Centre (Seville, Spain). During irradiations, the transistors were biased to improve the sensitivity, and the silicon temperature was monitored activating the parasitic diode of the MOSFET. Bias voltages of 0, 1, 5, and 10 V were applied to four sets of three transistors, obtaining an averaged sensitivity that was linearly dependent on this voltage. In addition, the short-fading effect was studied, and the uncertainty of this effect was obtained. The bias voltage that provided an acceptable sensitivity, (11.4 ± 0.9) mV/Gy, minimizing the uncertainty due to the fading effect (-0.09 ± 0.11) Gy was 1 V for a total absorbed dose of 40 Gy. Therefore, this off-the-shelf electronic device presents promising characteristics as a dosimeter sensor for proton beams.

Cosmetic benefits of a novel biomimetic lamellar formulation containing niacinamide in healthy females with oily, blemish-prone skin in a randomized proof-of-concept study.

OBJECTIVE: A randomized study was designed to evaluate the potential cosmetic benefit of a biomimetic, niacinamide-containing moisturizing cream in oily, blemish-prone skin. METHODS: Healthy adult women with oily, blemish-prone skin were randomized to one of three treatment groups: test, control, or positive control. In the test group, subjects used the test product (containing 4% niacinamide), plus the standard cleanser (Simple® Kind to Skin Moisturizing Facial Wash). In the control group, subjects received no moisturizer but used the standard cleanser. In the positive control group, subjects used Vivatinell Acnecinamide® Gel Cream (containing 4% niacinamide) as a moisturizer and Neutrogena Visibly Clear® Spot Clearing Facial Wash (containing 2% salicylic acid) as a cleanser. The positive control regimen was included to provide a comparison for estimates of effect size. The primary objective was to evaluate skin moisturization as a change from baseline in corneometer values at 8 h for the test regimen vs. the control regimen. Analysis of covariance was applied for the primary efficacy analysis. RESULTS: A total of 132 subjects were randomized with 44 included in each treatment group. A significant difference was observed in the primary endpoint for the test regimen compared with the control regimen (least-squares mean difference [95% CI]: 3.12 [0.68, 5.56], P = 0.0128). A trend was observed in favour of the positive control regimen compared with the control regimen. Secondary measurements of moisturization supported the primary efficacy outcome. Assessment of blemishes showed a significant difference between the test regimen vs. the control regimen for change from baseline in mean total blemish count at Week 8 (least-squares mean difference [95% CI]: -1.80 [-3.41, -0.19], P = 0.0290). No statistical comparisons between the positive control group and the test group were performed. CONCLUSION: This study provides proof-of-concept evidence that a novel lamellar lipid moisturizer containing niacinamide, in combination with a standard cleanser, can help moisturize the skin and provide an overall improvement in the complexion appearance of people with blemish-prone skin. STUDY REGISTRATION: NCT03093181.

OBJECTIF: Une étude randomisée a été conçue pour évaluer le bénéfice cosmétique potentiel d'une crème hydratante biomimétique contenant du niacinamide sur une peau grasse sujette aux imperfections. MÉTHODES: Des femmes adultes en bonne santé, à peau grasse sujette aux imperfections, ont été randomisées dans l'un des trois groupes de traitement : test, témoin ou témoin positif. Dans le groupe test, les sujets ont utilisé le produit testé (contenant 4 % de niacinamide), plus le nettoyant standard (Nettoyant visage Simple® doux pour la peau). Dans le groupe témoin, les sujets n'ont reçu aucune crème hydratante mais ont utilisé le nettoyant standard. Dans le groupe témoin positif, les sujets ont utilisé le gel crème Vivatinell Acnecinamide® (contenant 4 % de niacinamide) comme crème hydratante et le nettoyant visage pour réduire les imperfections Neutrogena Visibly Clear® (contenant 2 % d'acide salicylique) comme nettoyant. Le schéma de traitement du groupe témoin positif était inclus pour fournir une comparaison des estimations de la taille de l'effet. L'objectif principal était d'évaluer l'hydratation de la peau par le changement par rapport à la référence des valeurs du cornéomètre à 8 h pour le schéma de traitement testé par rapport au schéma de traitement témoin. Une analyse de covariance a été appliquée pour l'analyse de l'efficacité primaire. RÉSULTATS: Un total de 132 sujets ont été randomisés, dont 44 inclus dans chaque groupe de traitement. Une différence significative a été observée dans le critère d'évaluation principal en faveur du schéma de traitement testé par rapport au schéma de traitement témoin (différence moyenne des moindres carrés [IC à 95 %] : 3,12 [0,68, 5,56], P = 0,0128). Une tendance a été observée en faveur du schéma de traitement témoin positif par rapport au schéma de traitement témoin. Les mesures secondaires de l'hydratation ont appuyé le résultat principal d'efficacité. L'évaluation des imperfections a montré une différence significative entre le schéma de traitement testé par rapport au schéma de traitement témoin en ce qui concerne le changement par rapport à la référence dans le nombre moyen total d'imperfections à la semaine 8 (différence moyenne des moindres carrés [IC à 95 %] : _1,80 [_3,41, _0,19], P = 0,0290). Aucune comparaison statistique entre le groupe témoin positif et le groupe test n'a été réalisée. CONCLUSION: Cette étude fournit des éléments de preuve de concept qu'une nouvelle crème hydratante lipidique lamellaire à base de niacinamide, en association avec un nettoyant standard, peut permettre d'hydrater la peau et fournir une amélioration globale de l'aspect du teint chez des personnes dont la peau est sujette aux imperfections. Numéro d'enregistrement de l'étude : NCT03093181.

Protection of chickens vaccinated with combinations of commercial live infectious bronchitis vaccines containing Massachusetts, Dutch and QX-like serotypes against challenge with virulent infectious bronchitis viruses 793B and IS/1494/06 Israel variant 2.

Infectious bronchitis virus (IBV) is a coronavirus which affects chickens of all ages. IBV mainly causes respiratory disease but can also result in reduced weight gain, reduced egg production, increased frequency of abnormal eggs and increased rates of mortality. Vaccination is the most important way to control the disease. Nevertheless, novel strains of infectious bronchitis (IB) continue to emerge in the field. In order to respond promptly, combinations of existing IB vaccines are frequently tested to see whether they can provide cross-protection. The efficacy of a combination of vaccines based on Massachusetts, Dutch and QX-like IB strains against emerging IB Israel variant 2 and IB 793B strains was assessed by means of four challenge studies. At least 80% of the birds vaccinated with IB H120 (Mass type) combined with IB D274 (Dutch type) followed by a QX-like IB vaccine booster or vaccinated with a combination of IB H120, IB D274 and QX-like IB were protected against a challenge with IB 793B. In addition, IB 1263 (Mass type) boosted by QX-like IB showed an 85% protection following challenge with IB 793B. A combination of IB H120 and IB D274 boosted by QX-like IB vaccine conferred 70% protection whilst H120 and IB D274 combination on its own showed 61.1% protection against Israel variant 2 challenge. IB 1263 boosted by a QX-like IB vaccine showed 50% protection against IB Israel variant 2. Therefore, it can be concluded that a combination of the IB H120, IB D274 and QX-like IB confers broad protection against different non-related virulent IB strains.

SPF and UVA-PF sunscreen evaluation: are there good correlations among results obtained in vivo, in vitro and in a theoretical Sunscreen Simulator? A real-life exercise.

OBJECTIVE: Strategies to optimize the development of sunscreens include the use of theoretical sunscreen simulators to predict sun protection factor (SPF) and UVA protection factor (UVA-PF) and in vitro measurements of UVA-PF. The aims of this study were to assess the correlations between (1) SPF and UVA-PF results obtained in a theoretical sunscreen simulator with those observed in vivo (SPF and UVA-PF) and in vitro (UVA-PF) and (2) the results of UVA-PF observed in vitro and in vivo for products in different galenic forms containing or not pigments. METHODS: BASF Sunscreen Simulator software was used to evaluate the theoretical performance of formulations regarding SPF and UVA protection. In vitroUVA-PF and in vivoSPF were determined for all formulations. UVA-PFin vivo measurements were carried out only on products for which the galenic forms (compact foundations and lip balms) or the presence of dye or pigments could make the results of UVA-PFin vitro less reliable (due to a possible uneven film formation). RESULTS: The results of the SPF calculated by the BASF Sunscreen Simulator presented a very good correlation with SPF observed in vivo in the absence of pigments (r = 0.91; P < 0.05) and a good correlation in the presence of pigments (r = 0.70; P < 0.05). The UVA-PF calculated by the BASF Sunscreen Simulator also exhibited a very good correlation with UVA-PF measured in vitro (r = 0.88; P < 0.05) for the formulations not containing pigment and a good correlation (r = 0.75; P < 0.05) for the formulations containing pigment. The correlation of same UVA-PF calculated by BASF Sunscreen Simulator with UVA-PF measured in vivo for the formulations containing pigment was r = 0.74 (P < 0.05), which is considered good. In addition, the measurements of UVA-PFin vivo presented a good correlation with the values obtained in vitro (r = 0.74; P < 0.05). CONCLUSION: In the present study, the use of BASF Sunscreen Simulator and in vitroUVA tests showed good correlations with in vivo results and could be considered as valuable resources in the development of sunscreens.

Drug eruptions induced by telaprevir in patients with chronic hepatitis C virus genotype 1 infection: a prospective study.

INTRODUCTION: When co-administered with interferon and ribavirin, the prescription drug telaprevir significantly improves treatment response in patients with chronic hepatitis C virus (HCV) infection. Its use, however, also increases the likelihood of adverse effects that may lead to discontinuation of treatment. Cutaneous adverse effects are particularly common. OBJECTIVE: To determine the frequency and clinical characteristics of drug eruptions induced by telaprevir in patients receiving HCV treatment and to analyze the clinical course of lesions and response to treatment. MATERIAL AND METHODS: We performed a prospective observational study of all patients who started a treatment regimen that included telaprevir between May 2012 and July 2013. We recorded the demographic characteristics of the patients who developed telaprevir-induced eruptions, and analyzed the clinical characteristics of the lesions and their clinical course following the application of guideline-based treatment recommendations. RESULTS: Twenty (46%) of the 43 patients who received triple therapy with interferon, ribavirin, and telaprevir during the study period developed drug reactions attributable to telaprevir. The reaction was classified as mild or moderate (grades 1 or 2) in 90% of cases and consisted of an exanthem with erythematous-edematous scaling plaques and papules. The rash worsened, mainly by spreading, in about one-third of cases. The skin lesions led to discontinuation of treatment in 2 patients (4.6%). Sustained viral response was achieved in 34 patients (79%). CONCLUSIONS: Telaprevir-induced eruptions are common and often progress, but they rarely require patients to discontinue treatment.

Differential expression of the MHM region and of sex-determining-related genes during gonadal development in chicken embryos.

The chicken (Gallus gallus) embryo has been used as a classic model system for developmental studies because of its easy accessibility for surgical manipulation during embryonic development. Sex determination in birds is chromosomally based (ZZ for males and ZW for females); however, the basic mechanism of sex determination is still unknown. Here, the dynamics of expression of candidate genes implicated in vertebrate sex determination and differentiation were studied during embryonic chicken gonadal development. Gene expression profiles were obtained before, during, and after gonadal sex differentiation in females and males for DMRT1, SOX3, SOX9, DAX1, SCII, HINTZ, HINTW, and the male hypermethylated (MHM) region. Transcripts for the HINTZ, DMRT1, DAX1, SCII, and SOX9 genes were observed in both sexes, but expression was higher in male gonads and may be correlated with testicular differentiation. The expression patterns of HINTW, SOX3, and MHM suggest that they may act in ovary development and may be involved in meiosis entry. MHM was upregulated and DMRT1 was downregulated in females at the same developmental stage. This may indicate a regulation of DMRT1 by MHM ncRNA. Similar dynamics were observed between HINTW and HINTZ. This study reports on the MHM expression profile during gonadal development and its correlation with the expression of genes involved in vertebrate sex determination.

A new flexible regression model with application to recovery probability Covid-19 patients.

The aim of this study is to propose a generalized odd log-logistic Maxwell mixture model to analyze the effect of gender and age groups on lifetimes and on the recovery probabilities of Chinese individuals with COVID-19. We add new properties of the generalized Maxwell model. The coefficients of the regression and the recovered fraction are estimated by maximum likelihood and Bayesian methods. Further, some simulation studies are done to compare the regressions for different scenarios. Model-checking techniques based on the quantile residuals are addressed. The estimated survival functions for the patients are reported by age range and sex. The simulation study showed that mean squared errors decay toward zero and the average estimates converge to the true parameters when sample size increases. According to the fitted model, there is a significant difference only in the age group on the lifetime of individuals with COVID-19. Women have higher probability of recovering than men and individuals aged ≥60 years have lower recovered probabilities than those who aged <60 years. The findings suggest that the proposed model could be a good alternative to analyze censored lifetime of individuals with COVID-19.

Reproductive isolation and patterns of genetic differentiation in a cryptic butterfly species complex.

Molecular studies of natural populations are often designed to detect and categorize hidden layers of cryptic diversity, and an emerging pattern suggests that cryptic species are more common and more widely distributed than previously thought. However, these studies are often decoupled from ecological and behavioural studies of species divergence. Thus, the mechanisms by which the cryptic diversity is distributed and maintained across large spatial scales are often unknown. In 1988, it was discovered that the common Eurasian Wood White butterfly consisted of two species (Leptidea sinapis and Leptidea reali), and the pair became an emerging model for the study of speciation and chromosomal evolution. In 2011, the existence of a third cryptic species (Leptidea juvernica) was proposed. This unexpected discovery raises questions about the mechanisms preventing gene flow and about the potential existence of additional species hidden in the complex. Here, we compare patterns of genetic divergence across western Eurasia in an extensive data set of mitochondrial and nuclear DNA sequences with behavioural data on inter- and intraspecific reproductive isolation in courtship experiments. We show that three species exist in accordance with both the phylogenetic and biological species concepts and that additional hidden diversity is unlikely to occur in Europe. The Leptidea species are now the best studied cryptic complex of butterflies in Europe and a promising model system for understanding the formation of cryptic species and the roles of local processes, colonization patterns and heterospecific interactions for ecological and evolutionary divergence.

A phylogenetic revision of the Glaucopsyche section (Lepidoptera: Lycaenidae), with special focus on the Phengaris-Maculinea clade.

Despite much research on the socially parasitic large blue butterflies (genus Maculinea) in the past 40 years, their relationship to their closest relatives, Phengaris, is controversial and the relationships among the remaining genera in the Glaucopsyche section are largely unresolved. The evolutionary history of this butterfly section is particularly important to understand the evolution of life history diversity connected to food-plant and host-ant associations in the larval stage. In the present study, we use a combination of four nuclear and two mitochondrial genes to reconstruct the phylogeny of the Glaucopsyche section, and in particular, to study the relationships among and within the Phengaris-Maculinea species. We find a clear pattern between the clades recovered in the Glaucopsyche section phylogeny and their food-plant associations, with only the Phengaris-Maculinea clade utilising more than one plant family. Maculinea is, for the first time, recovered with strong support as a monophyletic group nested within Phengaris, with the closest relative being the rare genus Caerulea. The genus Glaucopsyche is polyphyletic, including the genera Sinia and Iolana. Interestingly, we find evidence for additional potential cryptic species within the highly endangered Maculinea, which has long been suspected from morphological, ecological and molecular studies.

Efficacy and safety of an attenuated live QX-like infectious bronchitis virus strain as a vaccine for chickens.

The attenuation of infectious bronchitis (IB) QX-like virus strain L1148 is described. The virus was passaged multiple times in embryonated specific pathogen free (SPF) chicken eggs, and at different passage levels samples were tested for safety for the respiratory tract and kidneys in 1-day-old SPF chickens. There was a clear decrease in pathogenicity for the respiratory tract and kidneys when the virus had undergone a large number of passages. Passage level 80 was investigated for safety for the reproductive tract in 1-day-old and 7-day-old SPF chickens. In 1-day-old chickens, 12.5% of the vaccinated birds had macroscopic lesions. No lesions were observed if the chickens had been vaccinated at 7 days of age. Passage level 80 was investigated for its ability to spread from vaccinated to non-vaccinated chickens and for dissemination in the body. The virus was able to spread from vaccinated chickens to groups of non-vaccinated chickens, and in the vaccinated birds the virus was found frequently in oro-pharyngeal and cloacal swabs. A fragment of the hypervariable region of the S1 protein of passage level 80 was sequenced and revealed nucleotide changes resulting in two amino acid substitutions. Passage level 80 was given additional passages to levels 82 and 85. Both passage levels were tested for efficacy in SPF chickens and passage level 85 was tested for efficacy in commercial chickens with maternally derived antibodies (MDA) against a challenge with QX-like strain IB D388. In both SPF chickens and chickens with MDA, the vaccines based on strain IB L1148 were efficacious against challenge.

Identification of a DNA methylation point in the promoter region of the bovine CYP21 gene.

The CYP21 (steroid 21-hydroxylase) gene is involved in the synthesis of steroid hormones. Bov-A2 is a retroposon that is common in ruminant genomes. The promoter region of bovine CYP21 contains a short interspersed nucleotide element of Bov-A2, which overlaps a putative Sp1 binding site. We looked for RFLP/HpaII polymorphism in the Bov-A2 element in bovine Zebu breeds by PCR-RFLP, and examined whether polymorphism in this element is associated with methylation. Among DNA samples from 135 Brazilian Zebu breed cattle, we identified an RFLP/HpaII polymorphism (T/C), which, based on a restriction methylation-sensitive assay employing HpaII and isoschizomer MspI enzymes (methylation-sensitive and -non-sensitive enzymes, respectively), appears to be a DNA methylation point. This is the first report of this polymorphism and on DNA methylation in the bovine CYP21 promoter region in Brazilian Zebu cattle.

Sexing single bovine blastomeres using TSPY gene amplification.

The testis-specific protein Y-encoded gene (TSPY) is a Y-specific gene present in variable copy number in many mammalian species, including cattle. We tested the applicability of the TSPY gene as a Y-specific marker to predict preimplantation embryo sex in Nelore (Bos indicus) cattle. Two blastomeres were removed from each embryo. A total of 36 single blastomeres and the remaining cells of their 18 matched in vitro conceived embryos were screened for TSPY amplification by nested-PCR. The results obtained from a single blastomere and the remaining cells of the same embryo were concordant in all cases. All blastomeres (16/16) from eight embryos produced with sexed sperm (specific for production of male embryos) were TSPY-positive. We conclude that TSPY is a good male-specific marker, the usefulness of which is probably enhanced by the high copy number. Other methods that are less time-consuming, such as real-time PCR, could be improved with the use of the TSPY gene sequences to generate primers and/or probes. This is the first report to demonstrate the applicability of the TSPY gene for sexing single cells in cattle.

DNA Barcoding of an Assembly of Montane Andean Butterflies (Satyrinae): Geographical Scale and Identification Performance.

DNA barcoding is a technique used primarily for the documentation and identification of biological diversity based on mitochondrial DNA sequences. Butterflies have received particular attention in DNA barcoding studies, although varied performance may be obtained due to different scales of geographic sampling and speciation processes in various groups. The montane Andean Satyrinae constitutes a challenging study group for taxonomy. The group displays high richness, with more of 550 species, and remarkable morphological similarity among taxa, which renders their identification difficult. In the present study, we evaluated the effectiveness of DNA barcodes in the identification of montane Andean satyrines and the effect of increased geographical scale of sampling on identification performance. Mitochondrial sequences were obtained from 104 specimens of 39 species and 16 genera, collected in a forest remnant in the northwest Andes. DNA barcoding has proved to be a useful tool for the identification of the specimens, with a well-defined gap and producing clusters with unambiguous identifications for all the morphospecies in the study area. The expansion of the geographical scale with published data increased genetic distances within species and reduced those among species, but did not generally reduce the success of specimen identification. Only in Forsterinaria rustica (Butler, 1868), a taxon with high intraspecific variation, the barcode gap was lost and low support for monophyly was obtained. Likewise, expanded sampling resulted in a substantial increase in the intraspecific distance in Morpho sulkowskyi (Kollar, 1850); Panyapedaliodes drymaea (Hewitson, 1858); Lymanopoda obsoleta (Westwood, 1851); and Lymanopoda labda Hewitson, 1861; but for these species, the barcode gap was maintained. These divergent lineages are nonetheless worth a detailed study of external and genitalic morphology variation, as well as ecological features, in order to determine the potential existence of cryptic species. Even including these cases, DNA barcoding performance in specimen identification was 100% successful based on monophyly, an unexpected result in such a taxonomically complicated group.

Effects of goat milk or milk replacer diet on meat quality and fat composition of suckling goat kids.

The effects of a diet with goat milk "GM" or milk replacer "MR" on the meat quality and fat composition of suckling Murciano-Granadina kids were studied. MR consisted of powdered skimmed milk, coconut oil and fat, and cereal products and by-products. Raw meat quality (moisture, protein, lipids, ash, collagen, cholesterol, haem pigments, CIELab colour, pH and water retention capacity), fatty acid "FA" composition and eating quality of cooked meat (odour, flavour and texture) were determined. Diet had only a slight effect on raw meat quality but had a pronounced effect on fatty acid composition and eating quality of cooked meat. MR diet increased the water/protein proportion in the muscle. The saturated/unsaturated FA ratio in GM and MR fat was 0.94 and 2.27, respectively. The major FA in GM and MR fat were C16:0 and C18:1, respectively. Short-chain C4-C12 hardly accumulated in the adipose tissue of suckling kid, increasing the relative percentages of C14-C20. This effect was more pronounced in MR fat, due to the fact that MR contained more short-chain fatty acids than GM. MR diet gave cooked meat a more intense characteristic goat meat odour and flavour, more tenderness and more juiciness than the natural suckling diet. This fact could be related to differences in meat and fat composition.

A helix-turn motif in the C-terminal domain of histone H1.

The structural study of peptides belonging to the terminal domains of histone H1 can be considered as a step toward the understanding of the function of H1 in chromatin. The conformational properties of the peptide Ac-EPKRSVAFKKTKKEVKKVATPKK (CH-1), which belongs to the C-terminal domain of histone H1(o) (residues 99-121) and is adjacent to the central globular domain of the protein, were examined by means of 1H-NMR and circular dichroism. In aqueous solution, CH-1 behaved as a mainly unstructured peptide, although turn-like conformations in rapid equilibrium with the unfolded state could be present. Addition of trifluoroethanol resulted in a substantial increase of the helical content. The helical limits, as indicated by (i,i + 3) nuclear Overhauser effect (NOE) cross correlations and significant up-field conformational shifts of the C(alpha) protons, span from Pro100 to Val116, with Glu99 and Ala117 as N- and C-caps. A structure calculation performed on the basis of distance constraints derived from NOE cross peaks in 90% trifluoroethanol confirmed the helical structure of this region. The helical region has a marked amphipathic character, due to the location of all positively charged residues on one face of the helix and all the hydrophobic residues on the opposite face. The peptide has a TPKK motif at the C-terminus, following the alpha-helical region. The observed NOE connectivities suggest that the TPKK sequence adopts a type (I) beta-turn conformation, a sigma-turn conformation or a combination of both, in fast equilibrium with unfolded states. Sequences of the kind (S/T)P(K/R)(K/R) have been proposed as DNA binding motifs. The CH-1 peptide, thus, combines a positively charged amphipathic helix and a turn as potential DNA-binding motifs.

Plasma leptin turnover rates in lean and obese Zucker rats.

Conscious female adult lean and obese Zucker rats were injected through the jugular vein with radioactive iodine-labeled murine leptin; in the ensuing 8 min, four blood samples were sequentially extracted from the carotid artery. The samples were used in a modified RIA for leptin, in which paired tubes received the same amount of either labeled or unlabeled leptin, thus allowing us to estimate both leptin levels and specific radioactivity. The data were used to determine the decay curve parameters from which the half-life of leptin (5.46 +/- 0.23 min for lean rats and 6.99 +/- 0.75 min for obese rats) as well as the size of its circulating pool (32 pmol/kg for lean rats and 267 pmol/kg for obese rats) and the overall degradation rate (96 fkat/kg for lean rats and 645 fkat/kg for obese rats) were estimated. These values are consistent with the hormonal role of leptin and the need for speedy changes in its levels in response to metabolic challenge.

Immunocytochemical investigation of normal and chronic lymphocytic leukaemia lymphocytes reveals unexpectedly frequent reactivity with some myelomonocytic associated antibodies.

Information about the expression of some myelomonocytic markers in lymphocytes of patients with B-CLL is scarce. We studied the CD13, CD14, CD11c and CD68 surface antigens in 42 controls and in 38 patients with B-CLL to detect their possible reactivity. Eighty-nine percent of B-CLL expressed very strongly the CD14 antigen; on the contrary, the other myelomonocytic antigens tested were very weakly expressed. Forty-one of 42 controls showed a few CD14-positive lymphocytes with a statistical difference between normal and CLL lymphocytes. No statistical difference was recorded either between CD14 expression and Rai's staging system or Binet's stages, nor between CD14 and bone marrow involvement and doubling time or between CD14 and heavy or light chain expression. A minor B lymphocytic subset in humans coexpresses the CD14 and CD5 antigens, it being increasingly speculated that B chronic lymphocyte leukaemias originate precisely from this B CD5- and CD14-positive cells. Just as the CD5 antigen is regarded as an excellent B-CLL marker, it seems to us that a strong expression of the CD14 antigen might have the same diagnostic relevance.

Trisomy 12 is a rare cytogenetic finding in typical chronic lymphocytic leukemia.

We have studied 61 cases of B-chronic lymphocytic leukemia (CLL), combining cytological features, conventional cytogenetics and in situ hybridization (ISH). The comparison of these results constitutes the main subject of this study. The patients were cytologically classified according to the FAB criteria as: chronic lymphocytic leukemia (CLL) typical type (48 cases) and CLL atypical types (13 cases). Chromosome analysis was carried out on lymphoid cells from peripheral blood. The following mitogens were used: phytohemagglutinin (PHA) 5%, pokeweed (PWM) and lipopolysaccharide from E. coli. The ISH was performed with a biotin-labeled, chromosome 12-specific alpha satellite DNA probe, pSP12-1. Trisomy 12 was not found in any of the 48 patients with the typical type of CLL and in contradistinction it was present in some patients with atypical types. This study emphasizes the great importance of a closer link between hematological morphology and the cytogenetic approach.