A phylogeny for North American Mallocybe (Inocybaceae) and taxonomic revision of eastern North American taxa.

A multigene phylogenetic assessment of North American species of Mallocybe is presented based on analyses of rpb1, rpb2, ITS, and 28S rDNA nucleotide data. This framework enables a systematic revision of the genus for 16 eastern North American species and captures taxonomic and phylogenetic diversity in a global context. A grade of two unusual and poorly known North American species stems from the most recent common ancestor of the genus that gives rise to three core subgroups named here as clades Unicolores, Nothosperma, and Mallocybe. The grade of taxa includes the poorly known Lepista praevillosa from Florida and a new species from the southern Appalachians, M. montana, both of which appear to be narrow-range endemics. Clade Nothosperma is characterized by Australian and New Zealand species, whereas clade Unicolores is composed of six species from eastern North America and East Asia. Clade Mallocybe is dominated by numerous north temperate taxa and constitutes the sister group to clade Nothosperma. These major clades are distinguished by a combination of phylogeny, morphology, geographic distribution, and ecology. In addition, four North American species are described as new: M. leucothrix, M. luteobasis, M. montana, and M. tomentella. Several names originating in North America, long ignored or misunderstood in the literature, are revitalized and established by type comparisons and modern reference material collected from or near type localities. In addition, 11 species were subjected to mass spectrometry muscarine assays, none of which contained detectable amounts of muscarine except for two: M. sabulosa and M. praevillosa. This confirms a diffuse phylogenetic distribution of muscarine within the genus. Taxonomic descriptions are presented for 16 species, several synonymies proposed, and four new combinations made. A key to species of eastern North American Mallocybe is presented, along with illustrations of important diagnostic features. Citation: Matheny PB, Kudzma LV, Graddy MG, Mardini SM, Noffsinger CR, Swenie RA, Walker NC, Campagna SR, Halling R, Lebeuf R, Kuo M, Lewis DP, Smith ME, Tabassum M, Trudell SA, Vauras J (2023). A phylogeny for North American Mallocybe (Inocybaceae) and taxonomic revision of eastern North American taxa. Fungal Systematics and Evolution 12: 153-201. doi: 10.3114/fuse.2023.12.09.

Genes controlling polyunsaturated fatty acid synthesis are developmentally regulated in broiler chicks.

1. The objective of this study was to characterise the regulation of the pathways that synthesise long-chain polyunsaturated fatty acids (PUFA) on developing adipose deposits in broiler embryos and chicks. Subcutaneous adipose depots were harvested from embryos and embryonic d E13, E15 and E17. Subcutaneous, abdominal and crop (neck) adipose, as well as liver, were collected at 7 and 14 d post-hatch. 2. Targeted RNA sequencing was used to quantify expression of 6 elongation of very long-chain fatty acid (ELOVL) genes, two isoforms of stearoyl-CoA desaturase (SCD and SCD5), and three fatty acid desaturases (FADS1, FADS2, and FADS6) in each depot and in the liver. Expression levels of marker genes for fatty acid oxidation and adipogenesis (peroxisome proliferator-activated receptor gamma (PPARG)) were quantified. Fatty acid composition of subcutaneous adipose was analysed using gas chromatograph-mass spectrometry (GC/MS). 3. Genes in the PUFA synthetic pathway were differentially expressed across developmental ages and between depots. These include elongase and desaturase genes, that have not previously been characterised in chicken. Correlation analyses identified subsets of co-regulated genes and fatty acids and highlighted relationships that may influence adipose metabolism and development. 4. It was concluded that PUFA synthesis is an active and dynamically regulated pathway in developing adipose deposits in the broiler chick. These data highlighted potential novel roles for specific elongase and desaturase genes in adipose deposition and metabolism.

Feeding increasing amounts of ruminally protected choline decreased fatty liver in nonlactating, pregnant Holstein cows in negative energy status.

The objectives were to determine the optimal feeding amount of choline in a ruminally protected form to reduce the triacylglycerol (TAG) concentration in liver and to increase TAG in blood plasma of dairy cows. Pregnant, nonlactating multiparous Holstein cows (n = 77) were blocked by body condition score (3.59 ± 0.33) and assigned to treatment at 64 ± 10 d before calculated calving date. Dietary treatments were top-dressing of 0, 30, 60, 90, or 120 g/d of ruminally protected choline (RPC; Balchem Corp., New Hampton, NY) ions to supply the equivalent of 0, 6.5, 12.9, 19.4, and 25.8 g/d of choline ions. Diets were formulated to exceed nutrient requirements for maintenance and pregnancy and fed in ad libitum amounts for the first 5 d. From d 6 to 15, cows were restricted to consume approximately 31% of their net energy requirements to simulate early lactating cows in negative energy balance. Methionine intake was maintained throughout each 15-d period. Liver was biopsied at 5 and 14 d and analyzed for TAG and glycogen. Blood was sampled on d 5 and 14 and plasma analyzed for glucose, insulin, cholesterol, ß-hydroxybutyrate, long-chain fatty acids, and haptoglobin. On d 14, a mixture of saturated long-chain fatty acids, ground corn, and dried molasses (50:37:13) was offered (908 g, as-is basis) 10 h after the single daily feeding. Blood samples were collected for 19 h and plasma analyzed for TAG and cholesterol to assess apparent absorption of dietary fat. Mean dry matter intake and energy balance decreased from means of 9.5 to 3.3 kg/d and from 0.6 to -9.2 Mcal of net energy for lactation/d during the ad libitum and restricted feeding periods, respectively. Plasma concentrations of the lipid-soluble choline biomolecules, namely total phosphatidylcholines, total lysophosphatidylcholines, and sphingomyelin, increased with choline supplementation. Feed restriction increased plasma concentrations of ß-hydroxybutyrate and free long-chain fatty acids, whereas those of glucose, insulin, and total cholesterol decreased. During feed restriction, concentration of hepatic TAG and plasma haptoglobin decreased linearly, whereas concentration of hepatic glycogen tended to increase quadratically with increasing intake of RPC. After fat supplementation, mean plasma concentration of TAG increased by an average of 21% with intake of RPC ions, peaking at intakes of ≥6.5 g/d of RPC ion. In summary, feeding RPC ions to cows in negative energy balance had increasing lipotropic effects on the liver when consumed up to 25.8 g/d, whereas feeding only 6.5 g/d increased concentrations of hepatic glycogen and TAG in the blood.

Synthesis and photophysical properties of a bichromophoric system hosting a disaccharide spacer.

The synthesis of an efficient energy donor-acceptor system is reported, together with its photophysical properties. The bichromophoric species has been conceived to show potentialities for biological applications since a biocompatible disaccharide spacer, constituted of d-galactose and d-glucose derivatives, was used in compound 12 to connect two BODIPY units with different absorption/emission properties. The luminescence spectrum in acetonitrile of 12 shows an intense fluorescence band with a maximum at about 770 nm that is almost identical to that of the lowest-energy BODIPY, regardless of the excitation wavelength used. The quantum yield is 0.2 with an excited state lifetime of 2.5 ns. Excitation and ultrafast transient absorption spectroscopy demonstrates that a very efficient energy transfer takes place in 12 from the highest-energy lying BODIPY subunit to the lowest-energy emissive BODIPY moiety, with a time constant of about 31 ps. Noteworthily, the emission of 12 falls in the near infrared window, suitable for potential biological applications.

Choline absorption and evaluation of bioavailability markers when supplementing choline to lactating dairy cows.

The metabolites of choline have a central role in many mammalian biological processes, and choline supplementation to the periparturient dairy cow improves hepatic lipid metabolism. However, variability in responses to choline supplementation has highlighted a lack of understanding of choline absorption in the lactating dairy cow. Our objective was to determine net choline absorption by measuring net portal fluxes of choline and choline metabolites in cows receiving either dietary supplements of rumen-protected choline (RPC) or abomasal delivery of choline (ADC). We also evaluated markers for choline bioavailability by examining relationships between net portal absorption of choline and choline metabolites in plasma and milk. Five late-lactation Holstein cows were used in a 5×5 Latin square design, with 5-d treatment periods and a 2-d interval between periods. Treatments were (1) control (0g/d of choline), (2) 12.5g/d of choline fed as RPC, (3) 25g/d of choline fed as RPC, (4) 12.5g/d of choline provided as ADC, and (5) 25g/d of choline provided as ADC. At the end of each 5-d period, milk was sampled and 9 blood samples were collected simultaneously from an artery and portal vein at 30-min intervals. Plasma, milk, and feed ingredient concentrations of acetylcholine, betaine, free choline, glycerophosphocholine, lysophosphatidylcholine, phosphatidylcholine, phosphocholine, and sphingomyelin were quantified by hydrophilic interaction liquid chromatography-tandem mass spectrometry. With an increasing dose of ADC, the net portal flux of free choline increased and regression analysis indicated 61% net absorption of the infused dose. Among the choline metabolites, only concentrations of betaine, free choline, and phosphocholine increased in both arterial plasma (3.9, 1.9, and 0.4 times, respectively) and milk (2.5, 1.4, and 1.0 times, respectively) with 25g/d of ADC relative to the control. For RPC, the net portal flux of free choline was low relative to ADC (13%), which was similar to the relative difference observed in the concentrations and yields of milk free choline and betaine (averaged 21%). When evaluating markers for choline bioavailability, betaine was the leading candidate. Betaine in plasma and milk (alone or in combination with phosphocholine) was strongly associated with net free choline portal flux (coefficient of determination ranging from 0.64 to 0.79). In summary, free choline supply to the lactating dairy cow increases only specific choline metabolites in plasma and milk, which can be potential markers for choline bioavailability.

A Bodipy as a luminescent probe for detection of the G protein estrogen receptor (GPER).

We report the rational design, based on docking simulations, and synthesis of the first fluorescent and selective probe of GPER for bioimaging purposes and functional dissecting studies. It has been conceived as a Bodipy derivative and obtained by accessible and direct synthesis. Its optical properties have been measured in different solvents, showing insensitivity to their polarity. Its binding to GPER was achieved by competition assays with [3H]E2 and [5,6-3H] nicotinic acid in ER-negative and GPER-positive SkBr3 breast cancer cells. SkBr3 cells, transfected with a GPER expression vector containing a FLAG tag, were used to confirm that the fluorophore binds to GPER in a specific manner.

The association of low-molecular-weight hydrophobic compounds with native casein micelles in bovine milk.

The agreed biological function of the casein micelles in milk is to carry minerals (calcium, magnesium, and phosphorus) from mother to young along with amino acids for growth and development. Recently, native and modified casein micelles were used as encapsulating and delivery agents for various hydrophobic low-molecular-weight probes. The ability of modified casein micelles to bind certain probes may derive from the binding affinity of native casein micelles. Hence, a study with milk from single cows was conducted to further elucidate the association of hydrophobic molecules into native casein micelles and further understand their biological function. Hydrophobic and hydrophilic extraction followed by ultraperformance liquid chromatography-high resolution mass spectrometry analysis were performed over protein fractions obtained from size exclusion fractionation of raw skim milk. Hydrophobic compounds, including phosphatidylcholine, lyso-phosphatidylcholine, phosphatidylethanolamine, and sphingomyelin, showed strong association exclusively to casein micelles as compared with whey proteins, whereas hydrophilic compounds did not display any preference for their association among milk proteins. Further analysis using liquid chromatography-tandem mass spectrometry detected 42 compounds associated solely with the casein-micelles fraction. Mass fragments in tandem mass spectrometry identified 4 of these compounds as phosphatidylcholine with fatty acid composition of 16:0/18:1, 14:0/16:0, 16:0/16:0, and 18:1/18:0. These results support that transporting low-molecular-weight hydrophobic molecules is also a biological function of the casein micelles in milk.

Alberta Breakthrough Pain Assessment Tool: A validation multicentre study in cancer patients with breakthrough pain.

BACKGROUND: Cancer-related breakthrough pain (BTP) is a common and quite challenging pain syndrome, with significant impact on quality of life. To date, no widely recognized and validated tool for the diagnosis and evaluation of BTP exists. The Alberta Breakthrough Pain Assessment Tool (ABPAT) underwent a validation process during its development, but no experience of its implementation in clinical practice has been reported. METHODS: ABPAT was tested in a cohort of cancer patients suffering from chronic severe cancer-related pain in order to assess its acceptability and efficacy as a tool for the characterization of BTP. RESULTS: A total of consecutive 249 patients from seven different centres were included in a 2-month study period and all completed the questionnaire; 231 out of the 249 (92.8%) stated that questions were easily understandable and 217 out of the 249 (87.1%) stated that the tool allowed to explain extensively the BTP problem. Physician-patient correlation tests about baseline BTP intensity and BTP relief by medication showed statistical significance at the level of p = 0.001 and p = 0.0001, respectively. Evaluation of the efficacy of BPT medication revealed a 78.2% of patients declaring a good relief from BTP, with a significant reduction of mean BTP numeric rating scale score (p = 0.0001), but only 55.9% of patients responded to be satisfied about time for onset of the relief. CONCLUSIONS: In this study, ABPAT resulted to be a well-accepted tool for BTP assessment and characterization in a relatively large cohort of cancer patients. It is effective in discovering the unmet needs of cancer patients and in exploring the outcomes of BTP treatment.

Circadian variation of breakthrough pain in cancer patients.

BACKGROUND: Breakthrough cancer pain (BTP) can place physical, psychological and economic burdens on patients and their productive life. By preventing instead of treating BTP after it occurs, the efficacy of analgesic treatment in cancer patients could be maximized. With this study, we investigated circadian variations in the occurrence of BTP events in cancer patients. METHODS: The circadian variation of BTP was assessed in two different series (group 1, n = 47; group 2, n = 76) of advanced cancer patients suffering from severe chronic pain and undergoing analgesic treatment with major opioids. RESULTS: BTP episodes showed a circadian pattern, with an acrophase occurring at 10:00 a.m. (p < 0.001) in all patients. When the two series of patients were considered separately, an acrophase was similarly observed, with 60% of BTP episodes recorded between 10:00 a.m. and 6:00 p.m. The circadian rhythm of BTP was maintained after stratifying the patients according to whether they had bone metastases or visceral metastases. BTP episodes negatively correlated with quality of life. CONCLUSIONS: BTP onset follows a circadian rhythm, with an acrophase occurring in the late morning.

Throwing velocity and kinematics in elite male water polo players.

AIM: Fifty-three members of the Italian Men Water Polo Team were filmed using two synchronized cameras, while they were shooting a goal. Considering the differences in body mass, height, training strategies and the technical-tactical features of the players, the aims of this study were to employ video-analysis techniques in order to investigate selected kinematic parameters in water polo throwing, and to provide comprehensive quantitative information on the throwing movement in relation to the different team player positions. METHODS: Video analysis was used to estimate the elbow angle at release, the shoulder angle at follow through, the back and head height at ball release, trunk rotation angle and ball velocity at release. RESULTS: Ball release velocities ranged from 21.0 to 29.8 m/s (average value 25.3±1.4 m/s), for field players. Goal keepers show the lowest team values (average 21.7±0.3 m/s). Similar to previous study results, ball release was typically reached just prior to the elbow approaching full extension (151.6±3.6°), and the follow through shoulder angle was 143±5.9°. CONCLUSION: No significant statistical difference was recorded between injured and non-injured athletes. No positive association was demonstrated between physical characteristics (body mass and height) and ball velocity.

Autoinducer-2 is produced in saliva-fed flow conditions relevant to natural oral biofilms.

AIMS: We evaluated the ability of a dual-species community of oral bacteria to produce the universal signalling molecule, autoinducer-2 (AI-2), in saliva-fed biofilms. METHODS AND RESULTS: Streptococcus oralis 34, S. oralis 34 luxS mutant and Actinomyces naeslundii T14V were grown as single- and dual-species biofilms within sorbarods fed with 25% human saliva. AI-2 concentration in biofilm effluents was determined by the Vibrio harveyi BB170 bioluminescence assay. After homogenizing the sorbarods to release biofilm cells, cell numbers were determined by fluorometric analysis of fluorescent antibody-labelled cells. After 48 h, dual-species biofilm communities of interdigitated S. oralis 34 and A. naeslundii T14V contained 3.2 x 10(9) cells: fivefold more than single-species biofilms. However, these 48-h dual-species biofilms exhibited the lowest concentration ratio of AI-2 to cell density. CONCLUSIONS: Oral bacteria produce AI-2 in saliva-fed biofilms. The decrease of more than 10-fold in concentration ratio seen between 1 and 48 h in S. oralis 34-A. naeslundii T14V biofilms suggests that peak production of AI-2 occurs early and is followed by a very low steady-state level. SIGNIFICANCE AND IMPACT OF THE STUDY: High oral bacterial biofilm densities may be achieved by inter-species AI-2 signalling. We propose that low concentrations of AI-2 contribute to the establishment of oral commensal biofilm communities.

Circulating gastrin and ghrelin levels in patients with colorectal cancer: correlation with tumour stage, Helicobacter pylori infection and BMI.

Many studies have pointed out a possible role of gut peptides, including gastrin and ghrelin, in the pathogenesis and natural history of gastrointestinal malignancies, one of the most common death cause in the Western world. The objective of this work is to check gastrin and ghrelin serum levels in patients with colorectal cancer according to tumour's location, stage, Helicobacter pylori infection and BMI, in order to understand the two peptides' behaviour through the tumour's natural history and evaluate their assay's use in research and clinical practice. Twenty-nine subjects affected by colorectal cancer and 50 healthy controls were studied. Circulating gastrin and ghrelin levels and H. pylori serum antibodies were assessed by radioimmunologic assay and ELISA method. Gastrin and ghrelin serum levels were respectively slightly higher and significantly lower in colon cancer patients than in controls. Gastrin levels were higher in patients carrying left colon cancer and H. pylori infection while ghrelin levels were lower in both these groups. Both hormones' serum levels decreased from tumour earlier to later stages. Significant differences persisted in the correlation between BMI and ghrelin levels in controls but not in patients. Additional studies are necessary to ascertain the significance of gastrin and ghrelin opposite behaviour in colon cancer probably linked with interferences in endocrine pathways involving other gut peptides in this compromised condition.

Serum OPG and RANKL levels before and after intravenous bisphosphonate treatment in Paget's disease of bone.

Paget's disease of bone (PDB) is a focal disorder of bone remodeling characterized by increased osteoclast-mediated bone resorption. Even though increasing evidence indicates enhanced nuclear factor-kB (NF-kB) signaling as a common mechanism involved in PDB and other related disorders, few studies investigated circulating osteoprotegerin (OPG) and receptor of activator of NF-kB-ligand (RANKL) levels in PDB patients. In this study we explored the relationships between OPG or RANKL levels and bone turnover markers in a group of patients with PDB, before and after intravenous bisphosphonate treatment (pamidronate 60 mg). Both OPG and RANKL were markedly elevated in PDB patients with respect to control groups (healthy or osteoporotic postmenopausal women and elderly men) and were positively associated with bone turnover markers. Higher levels of these cytokines were observed in polyostotic than monostotic PDB cases. The ratio between RANKL and OPG was more than 3-fold higher in PDB patients than in controls. Interestingly, in the group of patients treated with pamidronate, we found an increase in OPG levels that become statistically significant after 3 and 6 months from treatment. A trend toward a decrease in RANKL levels after treatment was also observed. The RANKL/OPG ratio was significantly reduced after 3 and 6 months of therapy. In contrast, in patients classified as non-responders, OPG and RANKL levels after pamidronate infusion did not significantly differ with respect to pre-treatment values. Thus, the positive effect of amino bisphosphonates in the treatment of PDB may be due to either direct or indirect suppression of RANKL-induced bone resorption through decreased RANKL and increased OPG production.

Exemestane after tamoxifen as adjuvant hormonal therapy in postmenopausal women with breast cancer: effects on body composition and lipids.

Recent studies have shown that administering the aromatase inhibitor exemestane after 2-3 years of tamoxifen therapy significantly improves disease-free survival in postmenopausal women with primary breast cancer in comparison with standard 5-year tamoxifen treatment. Although many of the adverse effects associated with exemestane and tamoxifen have been analysed, there are no comparative data concerning body weight and body composition. The aim of this randomised study was to evaluate the longitudinal changes in body composition and lipid profiles in postmenopausal women switched from tamoxifen to exemestane. In total, 60 overweight or obese postmenopausal patients were enrolled. Their anthropometric data, body composition, including fat mass (FM) and fat-free mass (FFM), and lipid profiles, caloric intake and physical activity were assessed 1 week before randomisation, and 6 and 12 months later. In all, 55 patients (27 on tamoxifen and 28 on exemestane) completed the 1-year study period. Fat mass had significantly decreased by month 12 in the exemestane, but not in the tamoxifen group; the between-group difference was statistically significant (P<0.01). The FFM/FM ratio had significantly increased in the exemestane group, but not the tamoxifen group; the between-group difference was statistically significant (P<0.05). Triglycerides and high-density lipoprotein cholesterol significantly decreased (P<0.01; P<0.05), and low-density lipoprotein cholesterol significantly increased (P<0.01) in the exemestane group at the end of the 1-year study period. Our findings suggest that switching patients to adjuvant exemestane treatment after at least 2 years of tamoxifen therapy may be associated with an advantage over continuing adjuvant tamoxifen treatment in terms of body composition.

Prevalence of Helicobacter pylori infection in male patients with osteoporosis and controls.

Cytokines that regulate bone turnover (tumor necrosis factor-alpha, interleukin-6, etc.) may influence the pathogenesis of skeleton disorders, such as osteoporosis. Since Helicobacter pylori infection increases the systemic levels of inflammatory cytokines, we investigated the possibility that this infection increases the risk of developing osteoporosis and affects the bone metabolism in a group of male patients with osteoporosis. We examined 80 osteoporotic male patients and 160 controls for serum antibodies to H. pylori and the CagA protein and determined, in patients alone, the most important biochemical and instrumental parameters of the disease. Fifty-one patients (63.7%) and 107 controls (66.8%) were seropositive for H. pylori infection (nonsignificant); 30 infected patients (58.8%) and 43 infected controls (40.1%) were positive for anti-CagA antibodies (P = 0.028; OR = 2.13). Levels of estradiol in infected CagA-positive patients were significantly lower than in infected CagA-negative patients (28.5 [SD = 10.18] vs. 39.5 [SD = 14.50] pg/ml; P = 0.002) and uninfected patients (35.2 [SD = 12.7] pg/ml; P = 0.028). Levels of urinary cross-laps(a marker of bone resorption) were increased in patients infected by CagA-positive strains compared to patients infected by CagA-negative strains (282.9 [SD = 103.8] vs. 210.5 [SD = 150.1]microg/mmol; P = 0.048) and uninfected patients (204.3 [SD = 130.1] microg/mmol; P = 0.016). Differences among uninfected and infected patients, independent of CagA status, were observed for other markers of bone turnover, but they did not reach statistical significance. Infection by CagA-positive H. pylori strains is more prevalent in men with osteoporosis, who show reduced systemic levels of estrogens and increased bone turnover. H. pylori infection by strains expressing CagA may therefore be considered a risk factor for osteoporisis in men.

Isolation and characterization of copolymers of beta-lactoglobulin, alpha-lactalbumin, kappa-casein, and alphas1-casein generated by pressurization and thermal treatment of raw milk.

Raw skim milk was submitted to high pressure (300 to 600 MPa) and temperature (4 to 70 degrees C) treatments for 2 or 5 min. The combined effects of pressure and temperature on milk proteins induced structural changes and polymer and copolymer formation characterized by anion-exchange and size-exclusion fast protein liquid chromatography and electrophoretic techniques. Approximately half of the beta-lactoglobulin formed polymers, and the other half formed large copolymers, mainly with kappa-casein, alpha-lactalbumin via intermolecular disulfide bond exchange, and alpha(s1)-casein via physicochemical interactions, in proportions of 1.0:0.7:0.3:0.1, respectively. Minor whey proteins (serum albumin, immunoglobulins, and lactoferrin) also participated in the formation of the copolymers but to a lesser extent. Two populations of the copolymers were found with apparent molecular masses ranging from 440 to 2000 kDa for the first and more than 2000 kDa for the second. On the contrary, for heated milks the aggregation kinetics obtained by combination of high pressure and thermal treatment were very fast, as no intermediates such as dimers and small size oligomers were observed after pressurization, whatever the temperature studied. Lactosylation of proteins as well as proteolysis were very limited. A beta-casein amino-terminal peptide of 22 kDa was specifically recovered in milk samples treated under the more drastic conditions (500 MPa/55 degrees C per 5 min and 600 MPa/70 degrees C per 5 min) and might have been generated by neutral proteases such as elastase released from somatic cells present in milk. No casein was released from the micelle whatever the combination of high pressure and temperature studied.

Antibacterial activity of lactophoricin, a synthetic 23-residues peptide derived from the sequence of bovine milk component-3 of proteose peptone.

A synthetic peptide of 23 residues corresponding to the carboxyterminal 113 to 135 region of component-3 of proteose peptone (PP3) has been investigated with regard to its antibacterial properties. This cationic amphipathic peptide that we refer to as lactophoricin, displayed a growth-inhibitory activity against both gram-positive and gram-negative bacteria. For most of the strains tested, bacterial growth was observed in the presence of lactophoricin except for Streptococcus thermophilus. In that case, lactophoricin exhibited a minimum inhibitory concentration of 10 microM and a minimum lethal concentration of 20 microM. No hemolysis of human red blood cells was detected for peptide concentrations between 2 to 200 microM, indicating that lactophoricin would be noncytotoxic when used in this concentration range.

Solvent switching of intramolecular energy transfer in bichromophoric systems: photophysics of (2,2'-bipyridine)tetracyanoruthenate(II)/pyrenyl complexes.

The supramolecular systems [Ru(Pyr(n)bpy)(CN)(4)](2-) (n = 1, 2), where one and two pyrenyl units are linked via two-methylene bridges to the [Ru(bpy)(CN)(4)](2-) chromophore, have been synthesized. The photophysical properties of these systems, which contain a highly solvatochromic metal complex moiety, have been investigated in water, methanol, and acetonitrile. In all solvents, prompt and efficient singlet-singlet energy transfer takes places from the pyrene to the inorganic moiety. Energy transfer at the triplet level, on the other hand, is dramatically solvent dependent. In water, the metal-to-ligand charge transfer (MLCT) emission of the Ru-based chromophore is completely quenched, and rapid (200 ps for n = 1) irreversible triplet energy transfer to the pyrene units is detected in ultrafast spectroscopy. In acetonitrile, the MLCT emission is practically unaffected by the presence of the pyrenyl chromophore, implying the absence of any intercomponent triplet energy transfer. In methanol, triplet energy transfer leads to an equilibrium between the excited chromophores, with considerable elongation of the MLCT lifetime. The investigation of the [Ru(Pyr(n)bpy)(CN)(4)](2-) systems in methanol provided a very detailed and self-consistent picture: (i) The initially formed MLCT state relaxes toward equilibrium in 0.5-1.3 ns (n = 1, 2), as monitored both by ultrafast transient absorption and by time-correlated single photon counting. (ii) The two excited chromophores decay with a common lifetime of 260-450 ns (n = 1, 2), as determined from the decay of MLCT emission (slow component) and of the pyrene triplet absorption. (iii) These equilibrium lifetimes are fully consistent with the excited-state partition of 12-6% MLCT (n = 1-2), independently measured from preexponential factors of the emission decay. Altogether, the results demonstrate how site-specific solvent effects can be used to control the direction of intercomponent energy flow in bichromophoric systems.

Leptin and body composition in healthy postmenopausal women.

BACKGROUND: Leptin has been proposed to be involved in central control of adiposity and fat distribution but the role of this peptide is controversial. The aim of our study was to test the relationship between serum leptin and body composition, fat distribution, and some biochemical markers such as fasting insulinemia and lipoproteins in a population of healthy Italian postmenopausal women. METHODS: One hundred and twenty-three postmenopausal women (62.1+/-8.7 years) were evaluated. Body composition (fat and lean mass) was assessed by dual-energy X-ray absorptiometry (DXA). Two regions of interest were determined for regional fat analysis. Serum leptin and insulinemia were measured by radioimmunoassay, lipoproteins with colorimetric methods and apolipoproteins nephelometrically. RESULTS: Plasma leptin levels are strongly related to total fat mass, in grams (r=0.73, p<0.001) or as a percentage of soft tissue (r=0.75, p<0.001), and to adiposity, calculated as ratio between lean and fat mass (r=0.76, p<0.001). A significant correlation was also found between serum leptin and central fat distribution (r=0.29, p<0.01). As concerns biochemical markers, serum leptin was significantly related to fasting insulin (r=0.38, p<0.001), total cholesterol (r=0.29, p<0.01), Apolipoprotein-B (r=0.35, p<0.001), and triglycerides (r=0.22, p<0.05). When corrected for total fat mass, the partial correlation coefficients remain significant for percentage of total body fat (r=0.27, p<0.01), adiposity (r=0.23, p<0.01), and fat proportion in android region (r=0.18, p<0.05). CONCLUSIONS: These data indicate that leptin levels are related to adiposity and fasting insulin levels; indeed fast insulin mantains significant correlation with leptin (r=0.23, p<0.01) after controlling for fat mass. Android distribution of fat mass in elderly women is associated with leptin concentration.

Evidence for membrane affinity of the C-terminal domain of bovine milk PP3 component.

Component PP3 is a phosphoglycoprotein isolated from bovine milk with unknown biological function, which displays in its C-terminal region a basic amphipathic alpha-helix, a feature often involved in membrane association. According to that, the behaviour of PP3 and of a synthetic peptide from the C-terminal domain (residues 113-135) was investigated in lipid environment. Conductance measurements indicated that the peptide was able to associate and form channels in planar lipid bilayers composed of neutral or charged phospholipids. Electrostatic interactions seemed to promote voltage-dependent channel formation but this was not absolutely required since the pore-forming ability of the 113-135 C-terminal peptide was also detected with the zwitterionic lipid bilayer. Additionally, a spectroscopic study using circular dichroism argues that the peptide adopts an alpha-helical conformation in interaction with neutral or charged micelles. Thus, the conducting aggregates in bilayers might be composed of a bundle of peptides in helical conformation. Besides, similar conductance measurements performed with the whole PP3 protein did not induce any channel fluctuations. However, with the latter, an early breakdown of the bilayers occurred, a finding that can be tentatively explained by a massive incorporation of PP3. In the light of the present results, it could be inferred that PP3 membrane attachment may be achieved by oligomerization of the C-terminal amphipathic helical region.