Light-Induced Subnanometric Modulation of a Single-Molecule Electron Source

Single-molecule electron sources of fullerenes driven via constant electric fields, approximately 1 nm in size, produce peculiar emission patterns, such as a cross or a two-leaf pattern. By illuminating the electron sources with femtosecond light pulses, we discovered that largely modulated emission patterns appeared from single molecules. Our simulations revealed that emission patterns, which have been an intractable question for over seven decades, represent single-molecule molecular orbitals. Furthermore, the observed modulations originated from variations of single-molecule molecular orbitals, practically achieving the subnanometric optical modulation of an electron source.

Structural insight into SARS-CoV-2 neutralizing antibodies and modulation of syncytia

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is initiated by binding of the viral Spike protein to host receptor angiotensin-converting enzyme 2 (ACE2), followed by fusion of viral and host membranes. Although antibodies that block this interaction are in emergency use as early coronavirus disease 2019 (COVID-19) therapies, the precise determinants of neutralization potency remain unknown. We discovered a series of antibodies that potently block ACE2 binding but exhibit divergent neutralization efficacy against the live virus. Strikingly, these neutralizing antibodies can inhibit or enhance Spike-mediated membrane fusion and formation of syncytia, which are associated with chronic tissue damage in individuals with COVID-19. As revealed by cryoelectron microscopy, multiple structures of Spike-antibody complexes have distinct binding modes that not only block ACE2 binding but also alter the Spike protein conformational cycle triggered by ACE2 binding. We show that stabilization of different Spike conformations leads to modulation of Spike-mediated membrane fusion with profound implications for COVID-19 pathology and immunity.

Bivalent binding of a fully human IgG to the SARS-CoV-2 spike proteins reveals mechanisms of potent neutralization

In vitro antibody selection against pathogens from naïve combinatorial libraries can yield various classes of antigen-specific binders that are distinct from those evolved from natural infection1-4. Also, rapid neutralizing antibody discovery can be made possible by a strategy that selects for those interfering with pathogen and host interaction5. Here we report the discovery of antibodies that neutralize SARS-CoV-2, the virus responsible for the COVID-19 pandemic, from a highly diverse naïve human Fab library. Lead antibody 5A6 blocks the receptor binding domain (RBD) of the viral spike from binding to the host receptor angiotensin converting enzyme 2 (ACE2), neutralizes SARS-CoV-2 infection of Vero E6 cells, and reduces viral replication in reconstituted human nasal and bronchial epithelium models. 5A6 has a high occupancy on the viral surface and exerts its neutralization activity via a bivalent binding mode to the tip of two neighbouring RBDs at the ACE2 interaction interface, one in the "up" and the other in the "down" position, explaining its superior neutralization capacity. Furthermore, 5A6 is insensitive to several spike mutations identified in clinical isolates, including the D614G mutant that has become dominant worldwide. Our results suggest that 5A6 could be an effective prophylactic and therapeutic treatment of COVID-19.

A SARS-CoV-2 protein interaction map reveals targets for drug repurposing

A newly described coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the causative agent of coronavirus disease 2019 (COVID-19), has infected over 2.3 million people, led to the death of more than 160,000 individuals and caused worldwide social and economic disruption1,2. There are no antiviral drugs with proven clinical efficacy for the treatment of COVID-19, nor are there any vaccines that prevent infection with SARS-CoV-2, and efforts to develop drugs and vaccines are hampered by the limited knowledge of the molecular details of how SARS-CoV-2 infects cells. Here we cloned, tagged and expressed 26 of the 29 SARS-CoV-2 proteins in human cells and identified the human proteins that physically associated with each of the SARS-CoV-2 proteins using affinity-purification mass spectrometry, identifying 332 high-confidence protein-protein interactions between SARS-CoV-2 and human proteins. Among these, we identify 66 druggable human proteins or host factors targeted by 69 compounds (of which, 29 drugs are approved by the US Food and Drug Administration, 12 are in clinical trials and 28 are preclinical compounds). We screened a subset of these in multiple viral assays and found two sets of pharmacological agents that displayed antiviral activity: inhibitors of mRNA translation and predicted regulators of the sigma-1 and sigma-2 receptors. Further studies of these host-factor-targeting agents, including their combination with drugs that directly target viral enzymes, could lead to a therapeutic regimen to treat COVID-19.

A SARS-CoV-2 protein interaction map reveals targets for drug repurposing

A newly described coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the causative agent of coronavirus disease 2019 (COVID-19), has infected over 2.3 million people, led to the death of more than 160,000 individuals and caused worldwide social and economic disruption^1,2. There are no antiviral drugs with proven clinical efficacy for the treatment of COVID-19, nor are there any vaccines that prevent infection with SARS-CoV-2, and efforts to develop drugs and vaccines are hampered by the limited knowledge of the molecular details of how SARS-CoV-2 infects cells. Here we cloned, tagged and expressed 26 of the 29 SARS-CoV-2 proteins in human cells and identified the human proteins that physically associated with each of the SARS-CoV-2 proteins using affinity-purification mass spectrometry, identifying 332 high-confidence protein-protein interactions between SARS-CoV-2 and human proteins. Among these, we identify 66 druggable human proteins or host factors targeted by 69 compounds (of which, 29 drugs are approved by the US Food and Drug Administration, 12 are in clinical trials and 28 are preclinical compounds). We screened a subset of these in multiple viral assays and found two sets of pharmacological agents that displayed antiviral activity: inhibitors of mRNA translation and predicted regulators of the sigma-1 and sigma-2 receptors. Further studies of these host-factor-targeting agents, including their combination with drugs that directly target viral enzymes, could lead to a therapeutic regimen to treat COVID-19.

A SARS-CoV-2-Human Protein-Protein Interaction Map Reveals Drug Targets and Potential Drug-Repurposing

An outbreak of the novel coronavirus SARS-CoV-2, the causative agent of COVID-19 respiratory disease, has infected over 290,000 people since the end of 2019, killed over 12,000, and caused worldwide social and economic disruption 1,2 . There are currently no antiviral drugs with proven efficacy nor are there vaccines for its prevention. Unfortunately, the scientific community has little knowledge of the molecular details of SARS-CoV-2 infection. To illuminate this, we cloned, tagged and expressed 26 of the 29 viral proteins in human cells and identified the human proteins physically associated with each using affinity-purification mass spectrometry (AP-MS), which identified 332 high confidence SARS-CoV-2-human protein-protein interactions (PPIs). Among these, we identify 66 druggable human proteins or host factors targeted by 69 existing FDA-approved drugs, drugs in clinical trials and/or preclinical compounds, that we are currently evaluating for efficacy in live SARS-CoV-2 infection assays. The identification of host dependency factors mediating virus infection may provide key insights into effective molecular targets for developing broadly acting antiviral therapeutics against SARS-CoV-2 and other deadly coronavirus strains.

Response of Maize Hybrids With and Without Rootworm- and Drought-Tolerance to Rootworm Infestation Under Well-Watered and Drought Conditions

Anecdotal data in the past have suggested that the effect of the western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), on maize yield is greater under drought and the effect of drought is greater under rootworm infestations, but no field experiments have controlled both moisture and rootworm levels. Field studies were conducted in 2012, 2013, and 2014 with treatments in a factorial arrangement of western corn rootworm infestation levels, and maize hybrids (with and without tolerance to drought and rootworm feeding). The experiment was repeated under well-watered and drought conditions in adjacent plots. Leaf water potential and stomatal conductance data suggested significant plant stress was achieved in the drought plots toward the end of the season each year and maize hybrids only played a minor role. In particular, in 2012 and 2013 yield was dramatically lower for the drought experiment than for the well-watered experiment. However, the impacts of rootworm infestation level and maize hybrids on water potential, stomatal conductance, and yield were variable across years and between experiments. In fact, the only year that the main effect of rootworm infestation levels significantly impacted yield was in 2014, when an extremely high infestation level was added and this was only for the well-watered portion of the experiment. Overall, rootworm infestation level played a relatively minor role in maize productivity and it did not appear that soil moisture level influenced that to a large degree.

Improvement of cognitive functions in chronic schizophrenic patients by recombinant human erythropoietin

Schizophrenia is increasingly recognized as a neurodevelopmental disease with an additional degenerative component, comprising cognitive decline and loss of cortical gray matter. We hypothesized that a neuroprotective/neurotrophic add-on strategy, recombinant human erythropoietin (rhEPO) in addition to stable antipsychotic medication, may be able to improve cognitive function even in chronic schizophrenic patients. Therefore, we designed a double-blind, placebo-controlled, randomized, multicenter, proof-of-principle (phase II) study. This study had a total duration of 2 years and an individual duration of 12 weeks with an additional safety visit at 16 weeks. Chronic schizophrenic men (N=39) with defined cognitive deficit (>or=1 s.d. below normal in the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS)), stable medication and disease state, were treated for 3 months with a weekly short (15 min) intravenous infusion of 40,000 IU rhEPO (N=20) or placebo (N=19). Main outcome measure was schizophrenia-relevant cognitive function at week 12. The neuropsychological test set (RBANS subtests delayed memory, language-semantic fluency, attention and Wisconsin Card Sorting Test (WCST-64) - perseverative errors) was applied over 2 days at baseline, 2 weeks, 4 weeks and 12 weeks of study participation. Both placebo and rhEPO patients improved in all evaluated categories. Patients receiving rhEPO showed a significant improvement over placebo patients in schizophrenia-related cognitive performance (RBANS subtests, WCST-64), but no effects on psychopathology or social functioning. Also, a significant decline in serum levels of S100B, a glial damage marker, occurred upon rhEPO. The fact that rhEPO is the first compound to exert a selective and lasting beneficial effect on cognition should encourage new treatment strategies for schizophrenia.

Grouping of accessions of Mexican races of maize revisited with SSR markers

Mexican races of maize (Zea mays L.) represent a valuable genetic resource for breeding and genetic surveys. We applied simple sequence repeat (SSR) markers to characterize 25 accessions of races of maize from Mexico. Our objectives were to (1) study the molecular genetic diversity within and among these accessions and (2) examine their relationships as assumed previously on the basis of morphological data. A total of 497 individuals were fingerprinted with 25 SSR markers. We observed a high total number of alleles (7.84 alleles per locus) and total gene diversity (0.61), confirming the broad genetic base of the maize races from Mexico. In addition, the accessions were grouped into distinct racial complexes on the basis of a model-based clustering approach. The principal coordinate analyses of the four Modern Incipient hybrids corroborated the proposed parental races of Chalqueño, Cónico Norteño, Celaya, and Bolita on the basis of the morphological data. Consequently, for some of the accessions, hybridizations provide a clue that can further be used to explain the associations among the Mexican races of maize.

Identification of essentially derived varieties with molecular markers: an approach based on statistical test theory and computer simulations

Genetic similarities (GS) based on molecular markers have been proposed as a tool for identification of essentially derived varieties (EDVs). Nevertheless, scientifically reliable criteria for discrimination of EDVs and independently derived varieties with GS estimates are scanty, and implementation into practical breeding has not yet taken place. Our objectives were to (1) assess the influence of chromosome number and length, marker density, and distribution, as well as the degree of polymorphism between the parental inbreds on the distribution of GS between parental inbreds and their progenies [GS(P1,O)] derived from F2 and different backcross populations and (2) evaluate these factors with regard to the power for distinguishing F2- versus BC1- and BC1- versus BC2-derived lines with molecular markers. We developed an approach based on statistical test theory for the identification of EDVs with molecular markers. Standard deviations and overlaps of distributions of GS(P1,O) of F2-, BC1-, and BC2-derived lines were smaller with (1) increasing chromosome number and length, (2) increasing marker density, and (3) uniformly instead of randomly distributed markers, approaching a lower boundary determined by the genetic parameters. The degree of polymorphism between the parental inbreds influenced the power only if the remaining number of polymorphic markers was low. Furthermore, suggestions are made for (1) determining the number of markers required to ascertain a given power and (2) EDV identification procedures.

Wheat genetic diversity trends during domestication and breeding

It has been claimed that plant breeding reduces genetic diversity in elite germplasm which could seriously jeopardize the continued ability to improve crops. The main objective of this study was to examine the loss of genetic diversity in spring bread wheat during (1) its domestication, (2) the change from traditional landrace cultivars (LCs) to modern breeding varieties, and (3) 50 years of international breeding. We studied 253 CIMMYT or CIMMYT-related modern wheat cultivars, LCs, and Triticum tauschii accessions, the D-genome donor of wheat, with 90 simple sequence repeat (SSR) markers dispersed across the wheat genome. A loss of genetic diversity was observed from T. tauschii to the LCs, and from the LCs to the elite breeding germplasm. Wheat's genetic diversity was narrowed from 1950 to 1989, but was enhanced from 1990 to 1997. Our results indicate that breeders averted the narrowing of the wheat germplasm base and subsequently increased the genetic diversity through the introgression of novel materials. The LCs and T. tauschii contain numerous unique alleles that were absent in modern spring bread wheat cultivars. Consequently, both the LCs and T. tauschii represent useful sources for broadening the genetic base of elite wheat breeding germplasm.

QTL mapping for European corn borer resistance ( Ostrinia nubilalis Hb.), agronomic and forage quality traits of testcross progenies in early-maturing European maize ( Zea mays L.) germplasm

In hybrid breeding the performance of lines in hybrid combinations is more important than their performance per se. Little information is available on the correlation between individual line and testcross (TC) performances for the resistance to European corn borer (ECB, Ostrinia nubilalis Hb.) in maize ( Zea mays L.). Marker assisted selection (MAS) will be successful only if quantitative trait loci (QTL) found in F(2) derived lines for ECB resistance are still expressed in hybrid combinations. The objectives of our study were: (1) to identify and characterize QTL for ECB resistance as well as agronomic and forage quality traits in a population of testcrossed F(2:3) families; (2) to evaluate the consistency of QTL for per se and TC performances; and (3) to determine the association between per se and TC performances of F(2:3) lines for these traits. Two hundred and four F(2:3) lines were derived from the cross between maize lines D06 (resistant) and D408 (susceptible). These lines were crossed to D171 and the TC progenies were evaluated for ECB resistance and agronomic performance in two locations in 2000 and 2001. Using these TC progenies, six QTL for stalk damage rating (SDR) were found. These QTL explained 27.4% of the genotypic variance in a simultaneous fit. Three QTL for SDR were detected consistently for per se and TC performance. Phenotypic and genotypic correlations were low for per se and TC performance for SDR. Correlations between SDR and quality traits were not significant. Based on these results, we conclude that MAS will not be an efficient method for improving SDR. However, new molecular tools might provide the opportunity to use QTL data as a first step to identify genes involved in ECB resistance. Efficient MAS procedures might then be based on markers designed to trace and to combine specific genes and their alleles in elite maize breeding germplasm.

Use of SSRs for establishing heterotic groups in subtropical maize

Heterotic groups and patterns are of fundamental importance in hybrid breeding. The objectives of our research were to: (1) investigate the relationship of simple sequence repeats (SSR) based genetic distances between populations and panmictic midparent heterosis (PMPH) in a broad range of CIMMYT maize germplasm, (2) evaluate the usefulness of SSR markers for defining heterotic groups and patterns in subtropical germplasm, and (3) examine applications of SSR markers for broadening heterotic groups by systematic introgression of other germplasm. Published data of two diallels and one factorial evaluated for grain yield were re-analyzed to calculate the PMPH in population hybrids. Additionally, 20 pools and populations widely used in CIMMYT's breeding program were assayed with 83 SSR markers covering the entire maize genome. Correlations of squared modified Roger's distance (MRD(2)) and PMPH were mostly positive and significant, but adaption problems caused deviations in some cases. For intermediate- and early-maturity subtropical germplasm, two heterotic groups could be suggested consisting of a flint and dent composite. We concluded that the relationships between the populations obtained by SSR analyses are in excellent agreement with pedigree information. SSR markers are a valuable complementation to field trials for identifying heterotic groups and can be used to introgress exotic germplasm systematically.

Plasma total homocysteine levels and prognosis in patients with previous premature myocardial infarction: a 10-year follow-up study

OBJECTIVES

To explore plasma total homocysteine (tHcy) as a predictor of long-term prognosis after premature myocardial infarction (MI).

DESIGN

Prospective cohort study.

SETTINGS

Akershus University Hospital.

SUBJECTS

A total of 247 patients (193 men and 54 women) in stable clinical phase after premature MI (males: first MI at age < or =55; females < or =60).

MAIN OUTCOME MEASURES

The primary end-point was total mortality and the secondary end-point was cardiac death. The third end-point was major cardiac events: a combination of cardiac death, MI and cardiac arrest.

RESULTS

After 10 years, 44 patients had died, 36 from cardiac causes. Major cardiac event occurred in 70 patients. The relative risk for death of all causes increased 1.43 (95% CI, 1.08-1.88) per tHcy quartile (P for trend = 0.01), and was only modestly reduced after adjustment for age, ejection fraction, total cholesterol, C-reactive protein, fibrinogen, smoking and hypertension to 1.37 (95% CI, 1.04-1.80) (P for trend = 0.03). Similar results were observed when cardiac death was used as the end-point, but we observed no association between tHcy and the end-point major cardiac event.

CONCLUSIONS

Total homocysteine was an independent predictor of total and cardiac mortality in stable patients following premature MI. tHcy had no effect on major cardiac event in contrast to most other risk factors in this study. Thus, the mechanism(s) underlying the effects of homocysteine on coronary heart disease may differ from other risk factors.

Plasma N-terminal pro-atrial natriuretic peptide predicts death after premature myocardial infarction, but not as well as radionuclide ejection fraction. A ten-year follow-up study

OBJECTIVE

To assess N-terminal pro-atrial peptide (N-ANP) as a predictor of total and cardiac death in patients with previous premature myocardial infarction (MI).

DESIGN

In this prospective cohort study, we measured plasma N-ANP by ELIZA assays and ejection fraction (EF) by radionuclide ventriculography in a cohort of 247 patients (193 men and 54 women) who had had MI at a relatively young age (males: first MI at age < or =55; females <60).

RESULTS

After 10 years 44 patients had died, 36 from cardiac causes. After using a stepwise procedure to adjust for other prognostic factors (i.e. plasma total homocysteine (tHcy), C-reactive protein and age), the relative risk (RR) was 2.00 (95% confidence interval (CI) 1.05-3.80) (p = 0.03) for death of all causes and 2.32 (95% CI 1.19-4.55) (p=0.01) for cardiac death when the top quartile was compared to the three lower quartiles of N-ANP. When radionuclide EF entered the Cox model, N-ANP became insignificant as a predictor of mortality.

CONCLUSION

N-ANP was a significant predictor of total death and cardiac death in young survivors of MI, but radionuclide EF was a more independent prognostic variable.

Plasma fibrinogen level and long-term prognosis in Norwegian middle-aged patients with previous myocardial infarction. A 10 year follow-up study

OBJECTIVES

To investigate the prognostic value of plasma fibrinogen level amongst middle-aged survivors of myocardial infarction (MI).

DESIGN

Prospective cohort study.

SETTINGS

Determination of fibrinogen and other prognostic variables in MI patients recruited in a presumably stable phase of coronary heart disease (CHD).

SUBJECTS

A total of 247 middle-aged CHD patients (54 women and 193 men) who had their first MI at age < or = 60 (women) or < or = 55 (men) were recruited at least 3 months after (mean 2.1 years) the most recent MI.

MAIN OUTCOME MEASURES

The primary endpoint was total mortality, and the secondary endpoint was cardiac deaths. The tertiary endpoint was major cardiac events (cardiac death, MI and cardiac arrest).

RESULTS

During a follow-up period of 10 years a total of 44 patients had died, 36 from cardiac causes. Major cardiac event occurred in 70 patients. After adjusting for age, ejection fraction (EF), total serum cholesterol (TC), smoking and hypertension, patients in the top quartile of fibrinogen (> or = 4.0 g L-1) had a relative risk (RR) of 1.8 (95% CI 1.0-3.6) (P = 0.07) for death of all causes. The top quartile of fibrinogen was a stronger predictor of cardiac death; RR = 2.2 (95% CI 1.1-4.4) (P = 0.03), whilst the effect on the endpoint major cardiac event was not significant; RR=1.1 (95% CI 0.6-1.9) (P = 0.69).

CONCLUSIONS

A plasma fibrinogen level in the top quartile predicted cardiac death in middle-aged patients who had suffered MI.

Lipid Composition and Fluidity of Plasma Membranes Isolated from Corn (Zea mays L.) Roots

Although the results of lipid analyses from several plant species have been available for many years a complete characterization of the corn root plasma membrane is still lacking. The present study provides a detailed analysis of individual lipids and a characterization of the membrane fluidity of corn (Zea mays L.) root plasma membranes isolated by phase-partitioning. Phospholipids (43.9 mol%), sterols (40.8 mol%), and sphingolipids in the form of glucocerebroside (6.8 mol%) constitute the major lipid classes. Stigmasterol (19.8 mol%), campesterol (13.0 mol%), phosphatidylcholine 15.8 mol%), and phosphatidylethanolamine (14.2 mol%) represent the most ubiquitous individual lipids. Hydroxy fatty acids make up 80.9 mol% and very long chain fatty acids are almost 78% of fatty acids in glucocerebroside. Hydroxy arachidic acid (20:0 h) and hydroxy lignoceric acid (24:0 h) are most prominent and glucocerebroside from corn root plasma membranes contains virtually no unsaturated fatty acids. Among the phospholipids only phosphatidylserine displayed a high proportion of very long chain fatty acids (e.g., behenic and lignoceric acid). Membrane fluidity was estimated by fluorescence anisotropy. Due to the high sterol content the plasma membrane of corn roots is relatively rigid.

The dermatopharmacologic profile of ciclopirox 8% nail lacquer

Ciclopirox 8% nail lacquer is a recently introduced topical formulation of the hydroxypyridone antimycotic ciclopirox. In vitro data indicate that ciclopirox has activity against the important pathogenic dermatophytes responsible for onychomycosis. The lacquer delivery system provides a high concentration gradient for the transfer of the antifungal agent through the nail plate. Daily application to the toenail surface of healthy subjects resulted in good penetration and distribution within all nail layers. Systemic absorption of ciclopirox in five patients with onychomycosis was minimal.

Dermatopharmacology of ciclopirox nail lacquer topical solution 8% in the treatment of onychomycosis

Ciclopirox is a synthetic hydroxypyridone antifungal agent. In contrast to the azoles, glucuronidation is the main metabolic pathway of ciclopirox; therefore interactions with drugs metabolized via the cytochrome P450 system are unlikely Ciclopirox is also distinct from the common systemic agents, which interfere with sterol biosynthesis. In fact, ciclopirox chelates trivalent cations (such as Fe3+), inhibits metal-dependent enzymes that are responsible for degradation of toxic metabolites in the fungal cells, and targets diverse metabolic (eg, respiratory) and energy producing processes in microbial cells. Ciclopirox is a broad spectrum antimicrobial with activity against all the usual dermatophytes as well as yeast and nondermatophyte molds. It has demonstrated activity against gram positive and negative bacteria, including resistant strains of Staphlococcus aureus. Ciclopirox exhibits fungal inhibitory activity (minimum inhibitory concentration < 4 microg/mL for dermatophytes) as well as fungicidal activity; to date resistance to the drug has not been identified. Ciclopirox has been formulated in a nail lacquer delivery system. After evaporation of volatile solvents in the lacquer, the concentration of ciclopirox in the remaining lacquer film reaches approximately 35%, providing a high concentration gradient for penetration into the nail. Radiolabel data demonstrate penetration into infected nails after only 1 application of the lacquer. Ciclopirox nail lacquer is a topical product that provides an active fungicidal agent in a delivery system capable of promoting nail penetration. With repeated applications, the antifungal agent is homogeneously distributed through all layers of the toenail achieving concentrations of ciclopirox in excess of inhibitory and fungicidal concentrations for most pathogens. Although ciclopirox readily penetrates nails, very low levels of ciclopirox are recoverable systemically, even after chronic use. Ciclopirox nail lacquer 8% is a topical product that provides an active fungicidal agent in a delivery system capable of penetrating nails.

Experimental evidences for a role of subinhibitory concentrations of rilopirox, nystatin and fluconazole on adherence of Candida spp. to vaginal epithelial cells

Candidiasis is frequently localized in the mucosal epithelium which covers the vaginal and oral cavity. The pathogenicity of Candida is correlated with its ability to adhere to epithelial cells and this is the resultant of both fungal and host cell properties and their physicochemical interactions. This study was performed to investigate the ability of subinhibitory concentrations (sub-MICs) of rilopirox, a new antimycotic drug, to interfere with the adhesion of Candida albicans, Candida tropicalis and Candida glabrata to human vaginal cells, in comparison with sub-MICs of nystatin and fluconazole. The three drugs are more active on C. albicans, followed by C. tropicalis and, last, C. glabrata, on which fluconazole was inactive (MIC > 24 micrograms/ml). Rilopirox, nystatin and fluconazole have different mechanisms of action, and different molecular weights, so a comparative analysis of data was performed by means of their sub-MICs. On this basis the order of activity was nystatin [symbol: see text] rilopirox > fluconazole. These findings can be of use for optimizing also the posologic design by regarding sub-MICs which are still active in reducing the adhesiveness of Candida to cells of the vaginal mucosa.

QTL for insect resistance and drought tolerance in tropical maize: prospects for marker assisted selection

Insects and drought cause severe losses in the production of maize in many developing countries. Conventional breeding efforts to enhance the level of resistance to a number of insect pests and tolerance to drought have been successful, although only through large efforts of many breeders and over a large period of time. Continued improvements will only be possible through substantial investment of resources. Recently, success in identifying quantitative trait loci (QTL) in several plant species using various molecular marker systems offers alternative methods for accelerating conventional breeding programs. As the first step towards using molecular markers in CIMMYT's maize breeding program, restriction fragment length polymorphisms (RFLPs) have been used to understand the genetic basis of resistance to two corn borer species, southwestern corn borer and sugarcane borer, and to one major component of drought tolerance, anthesis-silking interval. A number of QTL with effects large enough to be regarded as significant in breeding were detected for each of these traits and many of them presented stable effects over environments. While variability in the number and location of QTL has been found when compared across populations, several loci were found to be quite consistent. Simple calculations can be made which estimate that the total genetic potential in maize for these traits is high. It is argued that to ultimately access and manipulate this potential, the use of linked molecular markers as indirect selectable markers is both feasible and necessary.

Alterations in surface morphology of Candida albicans produced by rilopirox: a scanning electron microscopy study

The topological changes produced in Candida albicans cells by incubation in vitro with rilopirox have been investigated by scanning electron microscopy. Rilopirox is a new hydroxypyridone compound with fungicidal activity and the effects of 1x MIC (2.9 micrograms/ml) and 4 x MIC (11.6 micrograms/ml) after 1, 12, 24 hours of incubation were evaluated. The morphological alterations produced by rilopirox are round shapes, collapsed cells, surface folds, clusters, holes and thorn-like extrusion. The effects of rilopirox are already evident at 1 x MIC and after 1 h but their frequency and severity are correlated with the time of incubation and the MIC.

Inhibition of Candida albicans adhesiveness to human buccal and vaginal cells by sub-inhibitory concentrations of rilopirox

Candida albicans is an opportunistic dimorphic pathogenic yeast which is present on the human mucosal epithelial cell surface. Its adhesion is considered to be an important first step in colonization and in the subsequent symptomatic or asymptomatic infection of buccal or vaginal mucosa. Because the ability to adhere is an important element of the pathogenicity of Candida we investigated in this study the compared effects of sub-inhibitory concentrations (sub-MICs) of rilopirox (CAS 104153-37-9) with those of ciclopirox olamine (CAS 41621-49-2) in inhibiting Candida adhesion to human buccal (BEC) and vaginal cells (VEC). Rilopirox is a new hydroxypyridone antimycotic agent with strong activity, especially against Candida albicans. There was a significant reduction in the mean number of Candida adhering to both buccal and vaginal cells with up to 1/8 MIC rilopirox for buccal and 1/16 MIC for vaginal cells, while for ciclopirox olamine reduction was significant up to 1/16 MIC for buccal and 1/8 MIC for vaginal cells. There were no significant differences in the dose-effect curves for BEC and VEC with either rilopirox and ciclopirox olamine, but on a molar basis, rilopirox was more active than ciclopirox olamine. The present in-vitro results support the developmental concept of an oropharyngeal and vaginal preparation of rilopirox. It can be expected that even sub-inhibitory concentrations of rilopirox exert an important additional effect in the treatment of oral and vaginal candidosis by impairing the pathogenic adhesion process of the fungus.

XbaI polymorphism in DNA at the apolipoprotein B locus is associated with myocardial infarction (MI)

High levels of low density lipoprotein (LDL) and its apolipoprotein B (apoB) are risk factors for atherosclerosis and myocardial infarction (MI). There is rich genetic polymorphism in apoB, first detected as the Ag allotypes of LDL, but today mostly examined at the DNA level. Genes contribute to the population variation in LDL and apoB levels and alleles in polymorphisms at the apoB locus are candidate genes with respect to control of lipid levels and susceptibility to atherosclerosis and MI. The XbaI polymorphism at the apoB locus, which involves the third base of threonin codon 2488 (ACC-->ACT) without changing the amino acid sequence was examined in a case-control study comprising 238 survivors of myocardial infarction (MI) and 621 controls. In univariate analysis, frequencies of genotypes in this polymorphism were not statistically different between patients and controls of either sex. However, in multivariate logistic regression analysis, the odds ratio X-X- homozygotes (homozygotes for absence of restriction site) for having MI compared to the pooled group of heterozygotes and X+X+homozygotes (homozygotes for presence of restriction site) was 2.16 (p = 0.007), after adjustments for age, sex, and levels of apoB, high density lipoprotein (HDL) cholesterol (HDLC) and Lp(a) lipoprotein. It appeared that heterozygotes do not have increased risk, compared to the X+X+ homozygotes. Stratification according to low or high levels of apoB, HDLC and Lp(a) lipoprotein, showed that the X-X- genotype was more common in patients than controls, in all subgroups.(ABSTRACT TRUNCATED AT 250 WORDS)

The Effect of Practical Dietary Counseling on Food Variety and Regurgitation Frequency after Gastroplasty for Obesity

After obesity surgery, the primary measurement of success is the amount of weight lost. There has, however, been little assessment of how patients cope with the dietary constraints imposed by gastroplasty. Similarly, dietary patterns adopted to cope with these constraints have not been studied fully. These factors are of great importance in terms of nutritional adequacy, patient acceptability and long-term success. A study involving 32 patients was conducted to ascertain whether practical nutritional intervention and extensive follow-up would improve the overall outcome of the gastroplasty operation with respect to the type of foods tolerated and the incidence of regurgitation or vomiting experienced. To quantify success in terms of frequency of regurgitation and variety of food intake a vomiting/eating (V/E) score was devised. The results showed that the group of patients with more intensive practical education and counseling had a more varied intake of food and coped better with a wider variety of solid foods in the long term. Despite a more solid diet they did not regurgitate food as frequently as patients with less education, and over half the study group of patients reported no regurgitation at all. From this study, it is proposed that patients can be assessed and categorized postoperatively using a V/E scale. This scale numerically scores success with diet after gastroplasty, which, when recorded in conjunction with subsequent weight loss, can give a better quantification of success after obesity surgery.

Synthesis markers in illegally manufactured 3,4-methylenedioxyamphetamine and 3,4-methylenedioxymethamphetamine

In this paper the isolation and identification of 12 compounds as impurities in illicit 3,4-methylenedioxyamphetamine (MDA) and 3,4-methylenedioxymethamphetamine (MDMA) is reported. Isolation of these substances is performed by preparative TLC, while identification is performed by using mass spectrometry and 1H-NMR spectroscopy. A simple and rapid method for detection of these impurities in seized MDA and MDMA samples is described. The identification of the impurities can provide numerous points on which to base comparative analysis of different exhibits.

[Biofeedback without a technical team--simple and cost effective]

An important psychotherapeutic process is that of autogenous training, whose effectiveness can be improved by the use of biofeedback. Biofeedback procedures have hitherto called for considerable expenditure on apparatus and frequent therapy sessions. Despite this, it has not been possible to extend the relaxation effect to more general situations. This paper describes an inexpensive and practical method of utilising all the advantages afforded by the underlying therapeutic concept, on the basis of experience gained with cutaneous thermography. Further information, notably on the preparation of the laminae, can be had on request from the authors.

Different actions of 2 antidiarrheal agents, lidamidine and loperamide, on motility of the isolated cat colon muscle

Besides their action on intestinal absorption and secretion antidiarrheal agents may affect gastrointestinal motility. Little is known about motor actions in the large intestine. Therefore, the effects of loperamide and lidamidine on contractile and myoelectrical activity were studied in strips of the circular muscle of the cat colon in vitro. Both drugs caused a concentration dependent increase in spontaneous contractions, but the potency of loperamide was greater than that of lidamidine and the efficacy of lidamidine greater than that of loperamide. The corresponding EC50 were 2.9 X 10(-9) M and 1.4 X 10(-5) M, respectively, and the EC100 2.7 X 10(-7) M and 10(-4) M, respectively. In the myoelectrical tracings loperamide stimulated predominantly spike activity, lidamidine oscillatory potentials. The effect of loperamide was antagonized by naloxone, thus indicating an action on opiate receptors. The effect of lidamidine was not inhibited by a variety of drugs. Tetrodotoxin and alpha-adrenergic inhibitors even exaggerated the lidamidine effect, probably by a suppression of tonic nervous inhibition. The receptor for the lidamidine action has yet to be determined. In conclusion, the motor effects may play an important role in the antidiarrheal action of loperamide, but probably not in that of lidamidine, at least not within the range of clinically used doses.

A stretch of "late" SV40 viral DNA about 400 bp long which includes the origin of replication is specifically exposed in SV40 minichromosomes

Examination of DNA fragments produced from either formaldehyde-fixed or unfixed SV40 minichromosomes by multiple-cut restriction endonucleases has led to the following major results: Exhaustive digestion of unfixed minichromosomes with Hae III generated all ten major limit-digest DNA fragments as well as partial cleavage products. In striking contrast to this result, Hae III acted on formaldehyde-fixed minichromosomes to yield only one of the limit-digest fragments, F, which is located in the immediate vicinity of the origin of replication, spanning nucleotides 5169 and 250 on the DNA sequence map of Reddy et al. (1978). This 300 base pair (bp) fragment was released as naked DNA from formaldehyde-fixed, Hae III-digested minichromosomes following treatment either by pronase-SDS or by SDS alone. In the latter case, the remainder of the minichromosome retained its compact configuration as assayed by both sedimentational and electrophoretic methods. In minichromosomes, the F fragment is therefore not only accessible to Hae III at its ends, but is also neither formaldehyde cross-linked into any SDS-resistant nucleoprotein structure nor topologically "locked" within the compact minichromosomal particle. This same fragment was preferentially produced during the early stages of digestion of unfixed minichromosomes with Hae III, and its final yield in the exhaustive Hae III digest was significantly higher than that of other limit-digest fragments. Similar results were obtained upon digestion of either unfixed or formaldehyde-fixed minichromosomes with Alu I. In particular, of approximately twenty major limit-digest DNA fragments, only two fragments (F and P, encompassing nucleotides 5146 to 190, and 190 to 325, respectively) were produced by Alu I from the formaldehyde-fixed minichromosomes. All other restriction endonucleases tested (Mbo I, Mbo II, Hind III, Hin II+III and Hinf I), for which there are no closely spaced recognition sequences in the above mentioned regions of the SV40 genome, did not produce any significant amount of limit-digest DNA fragments from formaldehyde-fixed minichromosomes. These findings, taken together with our earlier data on the preferential exposure of the origin of replication in SV40 minichromosomes (Varshavsky, Sundin and Bohn, 1978), strongly suggest that a specific region of the "late" SV40 DNA approximately 400 bp long is uniquely exposed in the compact minichromosome. It is of interest that, in addition to the origin of replication, this region contains binding sites for T antigen (Tjian, 1977), specific tandem repeated sequences and apparently also the promoters for synthesis of late SV40 mRNAs (Fiers et al., 1978; Reddy et al., 1978).