The consequences of the COVID-19 pandemic on the refugee population: a rapid review.

AIMS: This is a rapid review examining the available evidence about the repercussions of the COVID-19 pandemic on the refugee population. METHODS: A search in the databases such as PubMed, Scopus, CINAHL, PsycINFO, and Web of Science was conducted and all relevant original articles, letters, and editorial and policy papers were included. RESULTS: From 208 publications matching the search criteria, 36 were included. These publications were categorized into three distinct domains: Public Health, Policies and Financing, and Technology. Our findings revealed that the situation of the refugee population has worsened during the pandemic. Difficulty accessing healthcare, violation of human rights, lack of access to technology devices, unfavorable government policies, and economic crisis were the most important aspects impacted by COVID-19. CONCLUSION: Governments, health managers, health professionals, and policy makers should be aware of refugees' problems during the pandemic to provide immediate solutions.

Very-high-frequency oscillations in the main peak of a magnetar giant flare.

Magnetars are strongly magnetized, isolated neutron stars1-3 with magnetic fields up to around 1015 gauss, luminosities of approximately 1031-1036 ergs per second and rotation periods of about 0.3-12.0 s. Very energetic giant flares from galactic magnetars (peak luminosities of 1044-1047 ergs per second, lasting approximately 0.1 s) have been detected in hard X-rays and soft γ-rays4, and only one has been detected from outside our galaxy5. During such giant flares, quasi-periodic oscillations (QPOs) with low (less than 150 hertz) and high (greater than 500 hertz) frequencies have been observed6-9, but their statistical significance has been questioned10. High-frequency QPOs have been seen only during the tail phase of the flare9. Here we report the observation of two broad QPOs at approximately 2,132 hertz and 4,250 hertz in the main peak of a giant γ-ray flare11 in the direction of the NGC 253 galaxy12-17, disappearing after 3.5 milliseconds. The flare was detected on 15 April 2020 by the Atmosphere-Space Interactions Monitor instrument18,19 aboard the International Space Station, which was the only instrument that recorded the main burst phase (0.8-3.2 milliseconds) in the full energy range (50 × 103 to 40 × 106 electronvolts) without suffering from saturation effects such as deadtime and pile-up. Along with sudden spectral variations, these extremely high-frequency oscillations in the burst peak are a crucial component that will aid our understanding of magnetar giant flares.

Novel antimicrobial phosphate-free glass-ceramic scaffolds for bone tissue regeneration.

In this study a phosphate-free glass-ceramic porous scaffold was synthesized by a three-step methodology involving slurry preparation, induction of porosity by surfactant-assisted foaming following by freeze-drying and sintering. This inorganic scaffold was characterized by X-ray diffraction, scanning electron microscope (SEM), degradation and bioactivity. Thermal treatment at 750 °C showed two new crystalline phases, combeite and nepheline, into the glassy matrix responsible for its properties. The cell response of the scaffold was also evaluated for using as a bone graft substitute. A commercial Biphasic Calcium Phosphate, BCP, scaffold was assessed in parallel as reference material. Microstructures obtained by SEM showed the presence of macro, meso and microporosity. The glass-ceramic scaffold possesses an interconnected porosity around 31% with a crack-pore system that promote the protein adsorption and cell attachment. Glass-ceramic scaffold with high concentration of calcium ions shows an antimicrobial behavior against Escherichia coli after 24 h of contact. Nepheline phase present in the glass-ceramic structure is responsible for its high mechanical properties being around 87 MPa. Glass-ceramic scaffold promotes greater protein adsorption and therefore the attachment, spreading and osteodifferentiation of Adipose Derived Stem Cells than BCP scaffold. A higher calcification was induced by glass-ceramic scaffold compared to reference BCP material.

Antimicrobial activity of submicron glass fibres incorporated as a filler to a dental sealer.

Two types of antimicrobial glass fibers containing ZnO and CaO, with diameters ranging from tens of nanometers to 1 µm, were successfully fabricated by a laser spinning technique. The antimicrobial performance was corroborated according to ISO 20743:2013, by using gram-negative (Escherichia coli) and gram-positive (Streptococcus oralis, Streptococcus mutans and Staphylococcus aureus) bacteria, and yeast (Candida krusei) (more than 3 logs of reduction). The metabolic activity and endosomal system of eukaryotic cells were not altered by using eluents of CaO glass submicrometric fibers and ZnO fibers at 1 : 10 dilution as cellular media (viability rates over 70%). A dental material was functionalized by embedding ZnO nanofibers above the percolation threshold (20% wt), creating a three-dimensional (3D) fiber network that added an antimicrobial profile. This new ZnO glass fiber composite is proved non-cytotoxic and preserved the antimicrobial effect after immersion in human saliva. This is the first time that a fiber-reinforced liner with strong antimicrobial-activity has been created to prevent secondary caries. The potential of developing new fiber-reinforced composites (FRCs) with antimicrobial properties opens up an extensive field of dental applications where most important diseases have an infectious origin.

Tuning of glyconanomaterial shape and size for selective bacterial cell agglutination.

Multivalent glycosystems are potential candidates for anti-adhesive therapy, a non-lethal approach against the ever increasing antibiotic resistance of pathogenic bacteria. In order to fine-tune the glyconanomaterial size and shape for selective bacterial cell agglutination, herein we report the synthesis of sugar-coated dynamic and polymeric 3D-micelles and 1D-carbon nanotubes. The reported shot-gun like synthetic approach is based on the ability of diacetylenic-based neoglycolipids to self-assemble into micelles in water and hierarchically self-assemble into hemimicelles on a single-walled carbon nanotube surface. The affinity of the nanosystems was preliminarily assessed by enzyme-linked lectin assay (ELLA) using the mannose-specific Concanavalin A lectin as a model receptor. Relative binding potency enhancements, compared to methyl α-d-mannopyranoside used as control, from 10- to 25- to 2340-folds in sugar molar basis were observed when passing from 3D dynamic micelles to static micelles, to 1D-mannose coated carbon nanotubes, respectively, indicative of a significant cluster glycoside effect. Importantly, these results were confirmed in vivo showing that the 1D-glyconanoring-coated carbon nanotubes efficiently and selectively regulate the agglutination and proliferation of the enterobacteria Escherichia coli type 1 fimbriae. These findings highlight the potential of sugar coated nano-materials as novel and effective tools in the control of bacterial pathogenesis.

Immunotherapy in prostate cancer: review of the current evidence.

Prostate cancer is the most common male malignancy in the Western world. Once it metastasizes, it is incurable. The current gold standard for metastatic disease is the combined docetaxel/prednisone regimen. Prostate cancer shows several characteristics that make it a suitable candidate for immunotherapy, as recently exemplified by the approval of sipuleucel-T, the first vaccine to treat any malignancy. Here, we review different tumor-associated antigen immunotherapy strategies currently being investigated, from a humanized radiolabeled monoclonal antibody (J-591) that targets radiation into tumor cells, moving on to vaccines and through to immunomodulator agents such as anti-CPLA-4 and anti-PD-1 monoclonal antibodies that activate T-cell responses via immune checkpoint inhibition. We explore different opinions on the best approach to integrate immunotherapy into existing standard therapies, such as androgen-deprivation therapy, radiotherapy or chemotherapy, and review different combination sequences, patient types and time points during the course of the disease to achieve a lasting immune response. We present data from recent phase III clinical trials that call for a change in trial endpoint design with immunotherapy agents, from the traditional tumor progression to overall survival and how such trials should include immune response measurements as secondary or intermediate endpoints to help identify patient clinical benefit in the earlier phases of treatment. Finally, we join in the recent questioning on the validity of RECIST criteria to measure response to immunotherapeutic agents, as initial increases in the size of tumors/lymph nodes, which are part of a normal immune response, could be categorized as disease progression under RECIST.

Epidemiología y pronóstico tardío de la sepsis en ancianos / Epidemiology and long-term outcome of sepsis in elderly patients

OBJETIVOS: Examinar los datos epidemiológicos de pacientes sépticos mayores de 65 años con ingreso en UCI e identificar predictores de supervivencia a 2 años. DISEÑO: Estudio de cohortes prospectivo. PACIENTES: Criterios de sepsis al ingreso a UCI. Ámbito: UCI de 40 camas en un hospital terciario. RESULTADOS: El estudio incluyó a 237 pacientes ancianos (≥ 65 años de edad) y 281 controles (< 65 años), n = 518. Al menos una enfermedad subyacente estaba presente en el 70% de los pacientes ancianos en comparación con solo el 56,1% en controles (p < 0,01). Entre los mayores de 65 años se registró mayor prevalencia de enfermedades crónicas (diabetes, enfermedad obstructiva pulmonar crónica e insuficiencia cardíaca crónica), presentación más frecuente como shock séptico (52,3 vs. 42%; p < 0,05) y abdomen como foco (52 vs. 36%; p < 0,01). El 9% de los pacientes dados de alta hospitalaria falleció en el seguimiento posterior de 2 años, aumentando hasta el 20% en los ancianos. Los predictores independientes de mortalidad a 2 años en los pacientes ancianos fueron: insuficiencia cardíaca crónica (hazard ratio ajustada [aHR] 2,24; intervalo de confianza del 95% [IC 95%] 1,28-3,94; p < 0,01), insuficiencia renal aguda (aHR 3,64; IC 95% 2,10-6,23; p < 0,01), insuficiencia respiratoria aguda (aHR 3,67; IC 95%: 2,31-5,86; p < 0,01) y antibioterapia empírica inadecuada (aHR 2,19; IC 95% 1,32-3,62; p < 0,01).Conclusiones La sepsis en mayores de 65 años presenta diferencias relevantes en sus características demográficas y presentación clínica. Tras ajustar por potenciales factores de confusión, la terapia antimicrobiana empírica inadecuada se asoció con una reducción del doble en la supervivencia a los 2 años

OBJECTIVES: A study was made of the epidemiological data of sepsis requiring admission to the ICU in patients over 65 years of age, with an evaluation of independent predictors of survival at 2 years. DESIGN: A prospective cohort study was made. PATIENTS: Patients meeting criteria for sepsis upon admission to the ICU. SETTING: A 40-bed ICU in a tertiary hospital. RESULTS: The study group included 237 elderly patients (≥ 65 years of age) and 281 controls (< 65 years of age) (n = 518). At least one chronic comorbid condition was present in 70% of the elderly patients as compared to only 56.1% of patients under age 65 (P < .01). There were several epidemiological differences between the groups: the prevalence of chronic diseases (diabetes, chronic obstructive pulmonary disease, and chronic heart failure), presentation as septic shock (52.3% vs 42%; P < .05), and the abdomen as the source of sepsis (52% vs 36%; P < .01) were all more frequent in elderly patients. Nine percent of the global patients discharged from hospital died in the 2-year follow-up period, but this rate reached 20% among the elderly. Independent predictors of 2-year mortality in the elderly were: chronic heart failure (adjusted hazard ratio [aHR] 2.24, 95% confidence interval [CI 95%] 1.28-3.94; P < .01), acute renal failure (aHR 3.64, 95%CI 2.10-6.23; P < .01), acute respiratory failure (aHR 3.67, 95%CI 2.31-5.86; P < .01), and inappropriate empirical antimicrobial therapy (aHR 2.19, 95%CI 1.32-3.62; P < .01). CONCLUSIONS: Sepsis showed different demographic characteristics and clinical presentations in the elderly. In the aging cohort, after adjusting for potential confounders, inadequate empirical antimicrobial therapy was associated to a 2-fold decrease in survival at two years

[Epidemiology and long-term outcome of sepsis in elderly patients]. / Epidemiología y pronóstico tardío de la sepsis en ancianos.

OBJECTIVES: A study was made of the epidemiological data of sepsis requiring admission to the ICU in patients over 65 years of age, with an evaluation of independent predictors of survival at 2 years. DESIGN: A prospective cohort study was made. PATIENTS: Patients meeting criteria for sepsis upon admission to the ICU. SETTING: A 40-bed ICU in a tertiary hospital. RESULTS: The study group included 237 elderly patients (≥ 65 years of age) and 281 controls (<65 years of age) (n=518). At least one chronic comorbid condition was present in 70% of the elderly patients as compared to only 56.1% of patients under age 65 (P<.01). There were several epidemiological differences between the groups: the prevalence of chronic diseases (diabetes, chronic obstructive pulmonary disease, and chronic heart failure), presentation as septic shock (52.3% vs 42%; P<.05), and the abdomen as the source of sepsis (52% vs 36%; P<.01) were all more frequent in elderly patients. Nine percent of the global patients discharged from hospital died in the 2-year follow-up period, but this rate reached 20% among the elderly. Independent predictors of 2-year mortality in the elderly were: chronic heart failure (adjusted hazard ratio [aHR] 2.24, 95% confidence interval [CI 95%] 1.28-3.94; P<.01), acute renal failure (aHR 3.64, 95%CI 2.10-6.23; P<.01), acute respiratory failure (aHR 3.67, 95%CI 2.31-5.86; P<.01), and inappropriate empirical antimicrobial therapy (aHR 2.19, 95%CI 1.32-3.62; P<.01). CONCLUSIONS: Sepsis showed different demographic characteristics and clinical presentations in the elderly. In the aging cohort, after adjusting for potential confounders, inadequate empirical antimicrobial therapy was associated to a 2-fold decrease in survival at two years.

Effect of high-pressure treatment of ewe raw milk curd at 200 and 300 MPa on characteristics of Hispánico cheese.

Hispánico cheese is a semihard variety made from a mixture of cow and ewe milks. Production of ewe milk declines in summer and autumn. To surmount the seasonal shortage of ewe milk and prevent the inactivation of milk enzymes by pasteurization, curd made in spring from ewe raw milk was pressurized at 200 and 300 MPa and stored frozen for 4 mo. Thawed ewe milk curds were added to fresh curd made from pasteurized cow milk for the manufacture of experimental Hispánico cheeses. Control cheese was made from a mixture of pasteurized cow and ewe milk in the same proportions as those used for experimental cheeses. Experimental cheeses exhibited lower dry matter content, higher aminopeptidase activity and total free amino acid concentration, and higher levels of acetic and propionic acids, aldehydes, alcohols, and esters compared with control cheese. In contrast, the concentration of total free fatty acids and ketones and the levels of textural parameters were significantly higher in control cheese. The use of ewe raw milk curd pressurized at 200 and 300 MPa, stored frozen and thawed for Hispánico cheese manufacture, was generally beneficial for cheese characteristics and increased cheese yield because of the lower dry matter content of experimental cheeses.

Phase I dose-escalating study of ES-285 given as a three-hour intravenous infusion every three weeks in patients with advanced malignant solid tumors.

BACKGROUND: ES-285 (spisulosine) is a novel compound derived from the marine mollusk Spisula polynoma with evidence of preclinical antitumor activity. This phase I clinical trial was designed to identify the maximum tolerated dose (MTD) and the recommended dose for phase II trials (RD), as well as to evaluate the safety profile, pharmacokinetics and preliminary efficacy data of ES-285 in patients with advanced solid tumors. PATIENTS AND METHODS: Sixty-one patients at two medical institutions were treated with a 3-h ES-285 intravenous infusion every 3 weeks. Nine dose levels were evaluated. RESULTS: No dose-limiting toxicities (DLTs) were observed during dose escalation from 4 to 128 mg/m(2). Six patients had seven DLTs at the three highest dose levels tested: 256 mg/m(2) (n = 2), 200 mg/m(2) (n = 3) and 160 mg/m(2) (n = 1). Grade 3/4 transaminase increases (n = 3), grade 3/4 central nervous system disorders [confusion (n = 2) and ataxia (n = 1)], and grade 3 pyrexia (n = 1) were the dose-limiting toxicities found with this ES-285 administration schedule. Pharmacokinetic analysis showed ES-285 dose linearity, wide distribution and a long half-life. One non-confirmed partial response was observed in a patient with metastatic melanoma treated with ES-285 128 mg/m(2), and 18 patients showed stable disease at different dose levels, lasting longer than 3 months in six patients. CONCLUSION: Dose level VIII (200 mg/m(2)) was considered the MTD, and dose level IX (160 mg/m(2)) was defined as the RD. Limited antitumor activity was observed.

Randomized comparison of metabolic and renal effects of saquinavir/r or atazanavir/r plus tenofovir/emtricitabine in treatment-naïve HIV-1-infected patients.

OBJECTIVES: The aim of the study was to compare the effects on lipids, body composition and renal function of once-daily ritonavir-boosted saquinavir (SQV/r) or atazanavir (ATV/r) in combination with tenofovir/emtricitabine (TDF/FTC) over 48 weeks. METHODS: An investigator-initiated, randomized, open-label, multinational trial comparing SQV/r 2000/100 mg and ATV/r 300/100 mg once daily, both in combination with TDF/FTC, in 123 treatment-naïve HIV-1-infected adults was carried out. The primary endpoint was to demonstrate noninferiority of SQV/r compared with ATV/r with respect to the change in fasting cholesterol after 24 weeks. Secondary outcome measures were changes in metabolic abnormalities, body composition, renal function, and virological and immunological efficacy over 48 weeks. Patients who had used at least one dose of trial drug were included in the analysis. RESULTS: Data for 118 patients were analysed (57 patients on SQV/r and 61 on ATV/r). At week 24, changes in lipids were modest, without increases in triglycerides, including a significant rise in high-density lipoprotein (HDL) cholesterol and a nonsignificant decrease in the total:HDL cholesterol ratio in both arms with no significant difference between arms. Lipid changes at week 48 were similar to the changes observed up to week 24, with no significant change in the homeostasis model assessment (HOMA) index. Adipose tissue increased regardless of the regimen, particularly in the peripheral compartment and to a lesser extent in the central abdominal compartment, with an increase in adipose tissue reaching statistical significance in the ATV/r arm. A slight decline in the estimated glomerular filtration rate (eGFR) was observed in both arms during the first 24 weeks, with no progression thereafter. The immunological and virological responses were similar over the 48 weeks. CONCLUSIONS: Combined with TDF/FTC, both SQV/r 2000/100 mg and ATV/r 300/100 mg had comparable modest effects on lipids, had little effect on glucose metabolism, conserved adipose tissue, and similarly reduced eGFR. The virological efficacy was similar.

Proteolysis, lipolysis, volatile compounds, texture, and flavor of Hispánico cheese made using frozen ewe milk curds pressed for different times.

Hispánico cheese is manufactured in Spain from a mixture of cow and ewe milk. Production of ewe milk varies throughout the year, with a peak in spring and a valley in summer and autumn. To overcome this seasonal shortage, curd from spring ewe milk may be frozen and used for cheese manufacture some months later. In the present work, ewe milk curds pressed for 15, 60, or 120 min were held at -24 degrees C for 4 mo, thawed, cut to 1-mm pieces, and mixed with fresh cow milk curd for the manufacture of experimental Hispánico cheeses. Control cheese was made from a mixture of pasteurized cow and ewe milk in the same (80:20) proportion. Cheeses, made in duplicate experiments, were analyzed throughout a 60-d ripening period. No significant differences between cheeses were found for lactic acid bacteria counts, dry matter content, hydrophilic peptides, 47 out of 68 vol.tile compounds, texture, and flavor characteristics. On the other hand, differences of minor practical significance between experimental and control cheeses, unrelated to the use of frozen ewe milk curd or the pressing time of ewe milk curd, were found for pH value, aminopeptidase activity, proteolysis, hydrophobic peptides, free amino acids, free fatty acids, and the remaining 21 vol.tile compounds. It may be concluded that the use of frozen ewe milk curd in the manufacture of Hispánico cheese does not alter its main characteristics.

Volatile compounds, odor, and aroma of La Serena cheese high-pressure treated at two different stages of ripening.

La Serena cheeses made from raw Merino ewe's milk were high-pressure (HP) treated at 300 or 400 MPa for 10 min on d 2 or 50 after manufacture. Ripening of HP-treated and control cheeses proceeded until d 60 at 8 degrees C. Volatile compounds were determined throughout ripening, and analysis of related sensory characteristics was carried out on ripe cheeses. High-pressure treatments on d 2 enhanced the formation of branched-chain aldehydes and of 2-alcohols except 2-butanol, but retarded that of n-aldehydes, 2-methyl ketones, dihydroxy-ketones, n-alcohols, unsaturated alcohols, ethyl esters, propyl esters, and branched-chain esters. Differences between HP-treated and control cheeses in the levels of some volatile compounds tended to disappear during ripening. The odor of ripe cheeses was scarcely affected by HP treatments on d 2, but aroma quality and intensity scores were lowered in comparison with control cheese of the same age. On the other hand, HP treatments on d 50 did not influence either the volatile compound profile or the sensory characteristics of 60-d-old cheese.

Oncogenic human papillomavirus (HPV) type distribution and HPV type 16 E6 variants in two Spanish population groups with different levels of HPV infection risk.

The aim of this study is to determine oncogenic human papillomavirus (HPV) types and HPV type 16 (HPV16) variant distribution in two Spanish population groups, commercial sex workers and imprisoned women (CSW/IPW) and the general population. A multicenter cross-sectional study of 1,889 women from five clinical settings in two Spanish cities was conducted from May to November 2004. Oncogenic HPV infection was tested by an Hybrid Capture II (HC2) test, and positive samples were genotyped by direct sequencing using three different primer sets in L1 (MY09/11 and GP5+/GP6+) and E6/E7. HPV16 variants were identified by sequencing the E6, E2, and L1 regions. Four hundred twenty-five samples were positive for the HC2 test, 31.5% from CSW/IPW and 10.7% from the general population. HPV16 was the most frequent type. Distinct profiles of oncogenic HPV type prevalence were observed across the two populations. In order of decreasing frequency, HPV types 16, 31, 58, 66, 56, and 18 were most frequent in CSW/IPW women, and types 16, 31, 52, 68, 51, and 53 were most frequent in the general population. We analyzed HPV16 intratype variants, and a large majority (78.7%) belonged to the European lineage. AA variants were detected in 16.0% of cases. African variants belonging to classes Af1 (4.0%) and Af2 (1.3%) were detected. Different HPV types and HPV16 intratype variants are involved in oncogenic HPV infections in our population. These results suggest that HPV type distribution differs in CSW/IPW women and in the general population, although further analysis is necessary.

Caseinolysis in cheese by Enterobacteriaceae strains of dairy origin.

AIMS: To study the effect of Enterobacteriaceae strains of dairy origin on caseins under cheese manufacture and ripening conditions. METHODS AND RESULTS: Strains belonging to the genera Enterobacter, Escherichia, Hafnia and Serratia were isolated from fresh raw milk cheeses. Residual caseins in cheeses made from milk individually inoculated with 10 strains of Enterobacteriaceae were determined by capillary electrophoresis. Hierarchical cluster analysis of strains based on data of residual caseins grouped together strains from the same genus, excepting Hafnia strains, which were separated into two groups. Serratia was the most proteolytic genus in our study. Preferences for degradation of casein fractions differed among the four genera studied. CONCLUSIONS: Enterobacteriaceae strains posses proteolytic systems active on all casein fractions under cheese manufacture and ripening conditions. The effects on caseins were similar for strains belonging to the same genus. SIGNIFICANCE AND IMPACT OF THE STUDY: The presence of Enterobacteriaceae in cheeses may affect proteolysis during ripening. Assays of Enterobacteriaceae proteolytic activity on milk agar plates may underestimate their caseinolytic activity in cheese.

Proteolysis, volatile compounds, and sensory evaluation in Hispánico cheese manufactured with the addition of a thermophilic adjunct culture, nisin, and calcium alginate-nisin microparticles.

Nisin, free or incorporated in calcium alginate microparticles, was added to pasteurized milk (80% cows' and 20% ewes' milk) used for the manufacture of Hispánico cheese with a mesophilic starter and a thermophilic adjunct culture of high aminopeptidase activity. Addition of nisin incorporated in microparticles promoted early lysis of thermophilic adjunct culture bacteria. Extracellular aminopeptidase activity in 1-d-old cheese made with both thermophilic adjunct culture and nisin incorporated in microparticles was 1.8-fold higher than in cheese made with thermophilic adjunct culture and free nisin and 2.0-fold higher than in cheese made only with thermophilic adjunct culture without any addition of nisin. Addition of nisin, free or incorporated in microparticles, did not influence cheese proteolysis measured using hydrophilic or hydrophobic peptides, o-phthaldialdehyde ripening index, or free amino acids. Moreover, a total of 37 volatile compounds were identified in the volatile fraction of Hispánico cheese, using a dynamic headspace technique with a purge and trap system followed by a gas chromatography mass spectrometry analysis. The volatile compound profile was not influenced by nisin addition, either free or incorporated in microparticles, but addition of thermophilic adjunct culture enhanced the formation of 2-butanone, diacetyl, 2,3-pentanedione and acetoin and improved the flavor quality (sensory panel) of cheese.

Effect of wild strains of Lactococcus lactis on the volatile profile and the sensory characteristics of ewes' raw milk cheese.

The production of volatile compounds by wild strains of Lactococcus lactis used as starter cultures and their effect on the sensory characteristics of ewes' raw milk cheese were investigated. Sixteen vats of cheese were manufactured and ripened for 120 d in two experiments, each of them duplicated. In the first experiment, milk was inoculated with different ratios of four wild Lactococcus lactis strains, two producing and two not producing branched-chain volatile compounds, and in the second experiment with different ratios of a commercial starter culture and the two strains producing branched-chain volatile compounds. Cheese pH, proteolysis, and aminopeptidase activity increased when the strains producing branched-chain volatile compounds were inoculated at a higher rate. Fifty volatile compounds were identified in cheeses using a purge and trap system coupled to a gas chromatography-mass spectrometry apparatus. The relative abundances of 30 volatile compounds (8 alcohols, 5 aldehydes, 3 ketones, 12 esters, 1 sulfur compound, and 1 benzenic compound) were influenced by starter culture composition. 2-Methylpropanol, 3-methylbutanol, isobutyl acetate, isoamyl acetate, ethyl butyrate, isobutyl butyrate, and isoamyl butyrate were always more abundant in the cheeses made with a higher level of L. lactis strains producing branched-chain volatile compounds. Flavor intensity was enhanced by a high level of L. lactis strains producing branched-chain volatile compounds in the first experiment, in which four wild L. lactis strains were used as starter culture, but not in the second experiment, in which a combination of two wild L. lactis strains and the commercial starter culture were used. Flavor quality, as judged by trained panelists, was impaired in both experiments by a high level of L. lactis strains producing branched-chain volatile compounds.

An in vivo binding assay to determine central alpha(1)-adrenoceptor occupancy using [(3)H]prazosin.

An alpha(1) adrenoceptor (alpha(1)-AdR) assay using [(3)H]prazosin binding in mouse brain is described which allows in vivo determination of central alpha(1)-AdR occupancy for ligands with alpha(1)-AdR affinity. Binding of [3H]prazosin in rat and mouse brain membranes in vitro was used to characterise the pharmacological profile of alpha(1)-AdRs in order to determine any potential species variations. Saturation and displacement studies yielded comparable affinity and pharmacological profile for [(3)H]prazosin binding in mouse and rat brain homogenates. These studies confirmed the absence of species variation for ligands in central alpha(1)-AdR pharmacology which is in good agreement with previous studies in rat brain. Subsequently, in vivo binding of [(3)H]prazosin in mouse whole brain was used to measure the occupancy of a number of AdR ligands. Timecourse studies revealed that a [3H]prazosin (5 mu Ci/mouse) pretreatment time of at least 20 min following intravenous (i.v.) administration was required for optimal specific binding. Ligands were administered systemically 40 min prior to i.v. administration of radiolabel. The alpha(1)-adrenoceptor ligands prazosin (ED(50)=0.15 mg/kg i.p.), benoxathian (0.52 mg/kg i.p.) and phentolamine (51 mg/kg i.p.) were all able to block in vivo [(3)H]prazosin binding from mouse brain. In addition, receptor occupancy values for a number of compounds including haloperidol (ED(50)=0.83 mg/kg s.c.), clozapine (2.2 mg/kg s.c.) and MDL-100907 [R(+)-alpha-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenylethyl)]-4-piperidine-methanol], (10 mg/kg s.c.)], which possess high to moderate affinity at alpha(1)-adrenoceptors, were also determined. These results suggest that in the mouse, [(3)H]prazosin binding can be used to measure in vivo receptor occupancy of ligands with affinity at central alpha(1)-adrenoceptors.

Hydrolysis of caseins and formation of hydrophilic and hydrophobic peptides by wild Lactococcus lactis strains isolated from raw ewes' milk cheese.

AIMS: To investigate the hydrolysis of alphaS1-, alphaS0-, betaB-, betaA1- and betaA2-caseins by 32 wild lactococci of different randomly amplified polymorphic DNA (RAPD) patterns, isolated from raw ewes' milk cheese, and the production of hydrophilic and hydrophobic peptides from whole casein by those strains. METHODS AND RESULTS: Most strains hydrolysed all caseins, and degraded beta-caseins to a larger extent than alphaS-caseins, when the proteolytic activity of whole cells was determined by capillary electrophoresis. Higher levels of hydrophilic than of hydrophobic peptides were produced from whole casein by all strains, according to reverse-phase high performance liquid chromatography analyses. CONCLUSIONS: Cell envelope proteinases of most lactococci isolated from raw ewes' milk cheese were CEPII, CEPII/III or CEPIII (classification of Exterkate et al. 1993). A negative correlation was found between degraded alphaS- and beta-caseins and a highly positive correlation between hydrophilic and hydrophobic peptides. SIGNIFICANCE AND IMPACT OF THE STUDY: Fast acid-producing lactococci from raw ewes' milk cheese have considerable and diverse caseinolytic activities. Their peptide production patterns do not reveal serious risks of bitter-flavour defect in cheeses if used as components of dairy starters.