The phenylpropanoid pathway inhibitor piperonylic acid induces broad-spectrum pest and disease resistance in plants

Although many phenylpropanoid pathway-derived molecules act as physical and chemical barriers to pests and pathogens, comparatively little is known about their role in regulating plant immunity. To explore this research field, we transiently perturbed the phenylpropanoid pathway through application of the CINNAMIC ACID-4-HYDROXYLASE (C4H) inhibitor piperonylic acid (PA). Using bioassays involving diverse pests and pathogens, we show that transient C4H inhibition triggers systemic, broad-spectrum resistance in higher plants without affecting growth. PA treatment enhances tomato (Solanum lycopersicum) resistance in field and laboratory conditions, thereby illustrating the potential of phenylpropanoid pathway perturbation in crop protection. At the molecular level, transcriptome and metabolome analyses reveal that transient C4H inhibition in tomato reprograms phenylpropanoid and flavonoid metabolism, systemically induces immune signalling and pathogenesis-related genes, and locally affects reactive oxygen species metabolism. Furthermore, C4H inhibition primes cell wall modification and phenolic compound accumulation in response to root-knot nematode infection. Although PA treatment induces local accumulation of the phytohormone salicylic acid, the PA resistance phenotype is preserved in tomato plants expressing the salicylic acid-degrading NahG construct. Together, our results demonstrate that transient phenylpropanoid pathway perturbation is a conserved inducer of plant resistance and thus highlight the crucial regulatory role of this pathway in plant immunity.

Discrepancies between actual weight, weight perception and weight loss intention amongst persons with NAFLD

BACKGROUND

Currently, weight loss remains the main management strategy for NAFLD, but the weight loss intention and methods remain poorly characterized.

METHODS

We analysed data about the perception of weight status, intention and methods to lose weight amongst 3,822 persons with NAFLD (United States Fatty Liver Index ≥ 30) from the National Health and Nutrition Examination Survey, 2001-2014.

RESULTS

Only 53.9% of people with NAFLD intended to lose weight, 91.8% with perception of overweight and 8.2% with normal weight perception. Persons with perception of overweight or overweight/obese status were four times more likely to try to lose weight (adjusted odds ratios 3.9 and 4.2, respectively, both P < 0.0001). Younger age, women, higher educational level, Hispanic and blacks (versus whites) were significant independent factors associated with weight loss intention. Notably, ≤10% attended weight loss programme. Metabolic equivalent of task hours per week was significantly higher in whites who exercised to lose weight (vs. no exercise, P = 0.003) but not in other racial/ethnic groups. Interestingly, calorie intake was similar between those who dieted versus not (2056 vs. 1970 kcal/day, P = 0.11). About 30% reported ≥ 10-lb weight loss, with 50% higher odds of success for men but there was no difference by race/ethnicity.

CONCLUSION

Overweight or obese perception was a key driver in weight loss activities but was inconsistent with actual weight status and varied by race/ethnicity and other sociodemographic factors. Weight loss programme is under-utilized and should take in account of weight perception training and culturally appropriate approach.

Molecular typing of conjunctivitis-causing adenoviruses in Hanoi, Vietnam from 2017 to 2019 and complete genome analysis of the most prevalent type (HAdV-8)

Adenoviral conjunctivitis is a common epidemic worldwide. In Vietnam, up to 80,000 patients are infected with adenoviral conjunctivitis annually. However, there are few investigations on the pathogenic adenoviruses that cause conjunctivitis. In total, 120 eye-swab samples were collected from patients with viral conjunctivitis symptoms in Hanoi, Vietnam from 2017 to 2019. Human adenoviruse (HAdV) was detected in 67 samples (55.83%) using polymerase chain reaction amplification of at least one of three HAdV-specific marker genes (hexon, penton, and fiber). Of the 67 HAdV samples, 46 samples could be analyzed by all three marker genes. DNA sequence analysis and phylogenetic tree building based on the three marker genes from the 46 HAdV samples revealed five different HAdV types associated with conjunctivitis in Hanoi, including HAdV-3 (4.3%), HAdV-4 (2.2%), HAdV-8 (89.1%), HAdV-37 (2.2%), and a potential recombinant type between types HAdV-8 and HAdV-3 (2.2%). This showed that HAdV-8 was the most common type identified in Hanoi. Complete genome analysis of HAdV-8 isolated from a Vietnamese patient (VN2017) using Sanger sequencing revealed 34 unique nucleotide changes, indicating that the adenovirus continuously accumulates new mutations. Hence, continuous surveillance of HAdV-8 changes in Vietnam is necessary in the future.

White hard clam (Meretrix lyrata) shells as novel filter media to augment the phosphorus removal from wastewater

It is well recognized that filter media play a crucial role in constructed wetlands (CWs) for decontamination of phosphorus (P)-rich wastewater. This study investigates the suitability of raw white hard clam shells (WHC) and white hard clam shells thermally modified at 800 °C (WHC-M800) as potential media to enhance P treatment performance in CWs. The results indicated that both WHC and WHC-M800 displayed appropriate physicochemical properties, such as high porosity, excellent hydraulic conductivity, and rich Ca content. WHC-M800 exhibited a superior P adsorption capacity (38.7 mg/g) to WHC (12.8 mg/g). However, the practical utilization of WHC-M800 as filter media in CWs may be compromised, due to certain limitations, for example: extremely high pH values in the post-adsorption solutions; high weight losses during calcination and adsorption processes; low mechanical strength; and intensive energy consumption. In contrast, the WHC demonstrated significant advantages of reasonably high P adsorption capacity, locally abundant availability, low cost, and marginal side effects. The fractionation of inorganic P of WHC and WHC-M800 revealed that Ca-bounded P was the most dominant binding form, followed by loosely bound P, Fe-P, occluded P, and Al-P. The present study demonstrates that recycling of WHC shells as a potential substrate in CWs provides a feasible method for upgrading P removal in CWs. Additionally, it helps to reduce waste WHC shells in a simple, cheap, and eco-friendly way, thus can double environmental benefits.

Globally altered epigenetic landscape and delayed osteogenic differentiation in H3.3-G34W-mutant giant cell tumor of bone

The neoplastic stromal cells of giant cell tumor of bone (GCTB) carry a mutation in H3F3A, leading to a mutant histone variant, H3.3-G34W, as a sole recurrent genetic alteration. We show that in patient-derived stromal cells H3.3-G34W is incorporated into the chromatin and associates with massive epigenetic alterations on the DNA methylation, chromatin accessibility and histone modification level, that can be partially recapitulated in an orthogonal cell line system by the introduction of H3.3-G34W. These epigenetic alterations affect mainly heterochromatic and bivalent regions and provide possible explanations for the genomic instability, as well as the osteolytic phenotype of GCTB. The mutation occurs in differentiating mesenchymal stem cells and associates with an impaired osteogenic differentiation. We propose that the observed epigenetic alterations reflect distinct differentiation stages of H3.3 WT and H3.3 MUT stromal cells and add to H3.3-G34W-associated changes.

The histone variant mutation H3.3-G34W occurs in the majority of giant cell tumor of bone (GCTB). By profiling patient-derived GCTB tumor cells, the authors show that this mutation associates with epigenetic alterations in heterochromatic and bivalent regions that contribute to an impaired osteogenic differentiation and the osteolytic phenotype of GCTB.

Prevalence, characteristics and mortality outcomes of obese, nonobese and lean NAFLD in the United States, 1999-2016

BACKGROUND

Updated prevalence and outcome data for nonobese NAFLD for the multi-ethnic US population is limited.

OBJECTIVES

We aimed to investigate the prevalence, clinical characteristics and mortality of obese and nonobese individuals with NAFLD in the United Sates.

METHODS

A retrospective study was conducted using the 1999-2016 NHANES databases. We determined hazard ratio stratified by obesity status in NAFLD individuals using Cox regression and log-rank test.

RESULTS

Overall NAFLD prevalence was 32.3%: 22.7% were obese and 9.6% were nonobese, with increasing trend over time for obese NAFLD, but not nonobese NAFLD. Amongst those with NAFLD, 29.7% (95% CI: 27.8%-31.7%) were nonobese, of which 13.6% had lean NAFLD. Nonobese NAFLD was more common in older (40.9% if ≥ 65 vs. 24.2% if < 65 years), male (34.0% vs. 24.2%) and foreign-born Asian people (39.8% vs. 11.4%) and uncommon in black (11.5% vs 30-35% in other ethnicities, P < 0.001). Metabolic comorbidities were common in nonobese NAFLD individuals who also had more advanced fibrosis. Nonobese NAFLD individuals had higher 15-year cumulative all-cause mortality (51.7%) than obese NAFLD (27.2%) and non-NAFLD (20.7%) (P < 0.001). However, DM and fibrosis, but neither obese nor nonobese NAFLD compared to non-NAFLD was independently associated with higher mortality.

CONCLUSION

Nonobese NAFLD makes up about one-third of the NAFLD in the United States (even higher in older, male and foreign-born individuals) and carries higher mortality than obese NAFLD. Screening for NAFLD should be considered in high-risk groups even in the absence of obesity.

Post-treatment Mortality Among Patients With Tuberculosis: A Prospective Cohort Study of 10 964 Patients in Vietnam

BACKGROUND

Tuberculosis is the leading infectious cause of death. Steep reductions in tuberculosis-related mortality are required to realize the World Health Organization's "End Tuberculosis Strategy." However, accurate mortality estimates are lacking in many countries, particularly following discharge from care. This study aimed to establish the mortality rate among patients with pulmonary tuberculosis in Vietnam and to quantify the excess mortality in this population.

METHODS

We conducted a prospective cohort study among adult patients treated for smear-positive pulmonary tuberculosis in 70 clinics across Vietnam. People living in the same households were recruited as controls. Participants were re-interviewed and their survival was established at least 2 years after their treatment with an 8-month standardized regimen. The presence of relapse was established by linking identifying data on patients and controls to clinic registries. Verbal autopsies were performed. The cumulative mortality among patients was compared to that among a control population, adjusting for age and gender.

RESULTS

We enrolled 10964 patients and 25707 household controls. Among enrolled tuberculosis patients, 9% of patients died within a median follow-up period of 2.9 years: 342 (3.1%) during treatment and 637 (5.8%) after discharge. The standardized mortality ratio was 4.0 (95% confidence interval 3.7-4.2) among patients with tuberculosis, compared to the control population. Tuberculosis was the likely cause of death for 44.7% of these deceased patients.

CONCLUSIONS

Patients treated for tuberculosis had a markedly elevated risk of death, particularly in the post-treatment period. Interventions to reduce tuberculosis mortality must enhance the early detection of drug-resistance, improve treatment effectiveness, and address non-communicable diseases.

New species and new genus of Pseudohaploporinae (Digenea): Pseudohaploporus pusitestis sp. n. and Parahaploporus elegantus n. g., sp. n. (Digenea: Pseudohaploporinae) from Vietnamese mullet fish

Two new species of Pseudohaploporinae, Pseudohaploporus pusitestis sp. n. and Parahaploporus elegantus n. g., sp. n., are described from intestines of the Vietnamese mullet fish Moolgarda seheli and Osteomugil cunnesius, respectively. Pseudohaploporus pusitestis sp. n. differs from two known Pseudohaploporus species, P. vietnamensis and P. planiliza, by the absence of a diverticulate hermaphroditic duct and muscular sphincters at the proximal end of the hermaphroditic sac. Metrically, P. pusitestis sp. n. is close to P. vietnamensis and differs from this species and from P. planilizum by lower maximum sizes of most parameters. Parahaploporus elegantus n. g., sp. differs from representatives of Pseudohaploporus by the presence of a single testis and the armament of hermaphroditic duct and is morphologically close to trematodes of the genus Haploporus. However, P. elegantus n. g differs from all known Haploporus species from mugilids of the Indo-West Pacific by the structure of the armament of the hermaphroditic duct and also by size of body, organs and eggs. The validity of designating two new species and a new genus of trematodes is supported by ITS and 28S rDNA sequence data. Phylogenetic reconstructions showed that the new trematodes belong to the Pseudohaploporinae, which formed a well-supported cluster within the monophyletic Haploporidae.

Al2O3, Al doped ZnO and SnO2 encapsulation of randomly oriented ZnO nanowire networks for high performance and stable electrical devices

Two-dimensional randomly oriented nanowire (NW) networks, also called nanonets (NNs), have remarkable advantages including low-cost integration, good reproducibility and high sensitivity, which make them a promising material for electronic devices. With this work, we focus on the study of ZnO NNs as channel materials in field effect transistors (FETs). In our process, ZnO NWs were assembled in NNs by the liquid filtration method and were integrated in transistors, with the bottom-gate configuration, using simple technological steps. Non-encapsulated devices exhibited state of the art performances but their stability toward air exposure was poor. Using a proper encapsulation of the nanonets, with cheap, abundant and non-toxic oxides, we demonstrate our ability not only to stabilize their electrical properties, but also to enhance performance to values never reach before for ZnO NW-based transistors. Our best FETs exhibit a low Off-current while maintaining a very good On-current, which results in a I _on/I _off ratio exceeding 10⁶ for a drain voltage of 5 V. The behavior of these ZnO NN-based FETs was studied for three different encapsulation materials, alumina (Al₂O₃), tin oxide (SnO₂) and Al-doped ZnO (AZO). These results prove that ZnO NNs are highly promising materials for an easy and low-cost integration into FETs.

Motivating HIV Providers in Vietnam to Learn: A Mixed-Methods Analysis of a Mobile Health Continuing Medical Education Intervention

BACKGROUND

The Mobile Continuing Medical Education Project (mCME V.2.0) was a randomized controlled trial designed to test the efficacy of a text messaging (short message service [SMS])-based distance learning program in Vietnam that included daily quiz questions, links to readings and online courses, and performance feedback. The trial resulted in significant increases in self-study behaviors and higher examination scores for intervention versus control participants.

OBJECTIVE

The objective of this mixed-methods study was to conduct qualitative and quantitative investigations to understand participants' views of the intervention. We also developed an explanatory framework for future trial replication.

METHODS

At the endline examination, all intervention participants completed a survey on their perspectives of mCME and self-study behaviors. We convened focus group discussions to assess their experiences with the intervention and attitudes toward continuing medical education.

RESULTS

A total of 48 HIV specialists in the intervention group completed the endline survey, and 30 participated in the focus group discussions. Survey and focus group data suggested that most clinicians liked the daily quizzes, citing them as convenient mechanisms to convey information in a relevant manner. A total of 43 of the 48 (90%) participants reported that the daily quizzes provided motivation to study for continuing medical education purposes. Additionally, 83% (40/48) of intervention participants expressed that they were better prepared to care for patients with HIV in their communities, compared with 67% (32/48) at baseline. Participation in the online coursework component was low (only 32/48, 67% of intervention participants ever accessed the courses), but most of those who did participate thought the lectures were engaging (26/32, 81%) and relevant (29/32, 91%). Focus group discussions revealed that various factors influenced the clinicians' decision to engage in higher learning, or "lateral learning," including the participant's availability to study, professional relevance of the topic area, and feedback. These variables serve as modifying factors that fit within an adapted version of the health belief model, which can explain behavior change in this context.

CONCLUSIONS

Qualitative and quantitative endline data suggested that mCME V.2.0 was highly acceptable. Participant behaviors during the trial fit within the health belief model and can explain the intervention's impact on improving self-study behaviors. The mCME platform is an evidence-based approach with the potential for adoption at a national scale as a method for promoting continuing medical education.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02381743; https://clinicaltrials.gov/ct2/show/NCT02381743.

Tailoring grating strip widths for optimizing infrared absorption signals of an adsorbed molecular monolayer

Metal structures with resonances in the mid-infrared spectral range enable an increased sensitivity for detecting molecular vibrational signals. 1D gold strip gratings have already proven potential in surface-enhanced infrared absorption (SEIRA) experiments, as grating resonances and local electric field enhancement can be spectrally tuned by changing the grating period. Here, we identify the grating strip width as another important design parameter, which is investigated for further optimization of molecular absorption signal enhancement in SEIRA experiments. Previous literature used gratings to increase light absorption in relatively thick polymer layers. Here, we demonstrate the capability of gold strip gratings fabricated on a CaF₂ substrate to enhance the CH₂ vibrational modes of a thiol-based monolayer of MHDA. An optimal choice of the strip width w = 1.33 μm enables a maximum vibrational signal enhancement factor of around 84, when normalized to microscopic GIR measurements of an MHDA monolayer on an extended gold surface. Numerical simulations demonstrate the broadband local field enhancement of gold strip gratings, which are suitable for enhancing multiple vibrational modes in a large hot-spot volume.

Implementing the mobile continuing medical education (mCME) project in Vietnam: making it work and sharing lessons learned

BACKGROUND

Mobile technology is a novel approach for delivering continuing medical education (CME), with numerous advantages including lower costs and the ability to reach larger numbers than traditional in-person CME workshops.

METHODS

From May 2015 to May 2017, we conducted two randomized controlled trials in a phased approach to evaluate the effectiveness of a mobile CME (mCME) approach for two cadres of health professionals in Vietnam. The first randomized controlled trial (RCT) tested the use of an SMS-based educational intervention among Community-Based Physician's Assistants; while feasible and acceptable, this intervention failed to improve medical knowledge among participants. Given the failure of the first RCT, and drawing on qualitative work conducted with participants at the conclusion of the trial, various modifications were employed in the second RCT conducted among HIV specialist physicians in Vietnam. Version 2.0 of the mCME intervention did lead to significant improvement in medical knowledge among intervention participants. Here, we discuss in detail the development of an mCME platform and the experiential "lessons learned" during two phases of implementation.

RESULTS

Numerous lessons were learned during implementation, including the importance of: (I) mixed methods approaches; (II) an underlying theoretical framework for behavior change projects; (III) expertise in software programming; (IV) aligning educational content to a well-defined participant population; and (V) engaging and motivating adult learners. We also discuss the critical importance of projects with local ownership and investment that are relevant to local problems.

CONCLUSIONS

mHealth approaches for continued healthcare training and education is increasingly relevant in many low-resource settings, the lessons learned here will be valuable to other organizations looking to scale-up similar mHealth-type educational programmes.

Interferometric analysis of sub-nanosecond laser-induced optical breakdown dynamics in the bulk of fused-silica glass

Dynamics of laser-induced optical breakdown in the bulk of fused-silica glass irradiated by a sub-nanosecond laser pulse at a wavelength of 790 nm with a fluence of 522 J/cm² was studied by the femtosecond time-resolved complex interferometry in Nomarski arrangement utilising a Fresnel bi-prism. Evolution of the plasma channel and the development of the free electron density were in focus of the investigation. The measured ultimate length of the plasma channel was equal to 30 μm and almost doubled the length estimated within the moving breakdown model. The history of the transient electron density distribution in the plasma was reconstructed from the phase shift maps using the inverse Abel transform and it revealed further deviation from this model. The core of the plasma channel exhibited at the last stages of the development a considerable level of the electron density up to 2.4×10²⁰ cm^-3. The signature of the pre-breakdown phase has been identified as radiation caused by ionization-released electrons interacting with ions and has been demonstrated in solids for the first time in this way. Origin of the discrepancy between the theoretical prediction of the moving breakdown model and the measured values of the channel length is discussed as well.

mCME project V.2.0: randomised controlled trial of a revised SMS-based continuing medical education intervention among HIV clinicians in Vietnam

BACKGROUND

Continuing medical education (CME) is indispensable, but costs are a barrier. We tested the effectiveness of a novel mHealth intervention (mCME V.2.0) promoting CME among Vietnamese HIV clinicians.

METHODS

We enrolled HIV clinicians from three provinces near Hanoi. The 6-month intervention consisted of (1) daily short message service multiple-choice quiz questions, (2) daily linked readings, (3) links to online CME courses and (4) feedback messages describing the performance of the participant relative to the group. Control participants had equal access to the online CME courses. Our primary endpoint was utilisation of the online CME courses; secondary endpoints were self-study behaviour, performance on a standardised medical exam and job satisfaction.

RESULTS

From 121 total HIV clinicians in the three provinces, 106 (87.6%) enrolled, and 48/53 intervention (90%) and 47/53 control (89%) participants completed the endline evaluations. Compared with controls, intervention participants were more likely to use the CME courses (risk ratio (RR) 2.3, 95% CI 1.4 to 3.8, accounting for 83% of course use (P<0.001)). Intervention participants increased self-study behaviours over controls in terms of use of medical textbooks (P<0.01), consulting with colleagues (P<0.01), searching on the internet (P<0.001), using specialist websites (P=0.02), consulting the Vietnam HIV/AIDS treatment guidelines (P=0.02) and searching the scientific literature (P=0.09). Intervention participants outperformed controls on the exam (+23% vs +12% score gains, P=0.05) and had higher job satisfaction.

CONCLUSION

The mCME V.2.0 intervention improved self-study behaviour, medical knowledge and job satisfaction. This approach has potential for expansion in Vietnam and similar settings.

TRIAL REGISTRATION NUMBER

NCT02381743.

Effect of cell membrane permeability protein on porcine oocyte vitrification

BACKGROUND

The discovery of proteins with inherent cell membrane-translocating activity will expand our ability to study and manipulate various intracellular processes in living systems.

OBJECTIVE

We investigated the effect of TAT-EGFP (trans-activator of transcription-enhanced green fluorescent protein) intra-cellular delivery on the survival and development of mature porcine oocytes after cryopreservasion.

MATERIALS AND METHODS

Cumulus-oocyte complexes (COCs) collected from follicles 3 to 6 mm in diameter in abattoir-derived oocytesries of prepubertal gilts were on vitro matured (IVM). After IVM, the oocytes were used for TAT-EGFP delivery test and cryopreservation with and without TAT-EGFP supplementation. Oocyte viability was assayed by staining with fluorescein diacetate. Live oocytes were parthened and cultured in vitro, to assess their ability to be activated and to therefore develop.

RESULTS

The results show that the TAT-EGFP was well delivered into the nuclear of the Hela cell and oocytes also. In the medium toxic test, the proportion of viable oocytes in seven groups showed no significance. In vitrification experiments, the viability of oocytes in group supplemented with TAT-EGFP was significantly higher than that in the without TAT-EGFP group and the control groups (27.7%, 90.4%, and 100%, respectively). Among the three groups, the developmental abilities of oocytes in the supplement TAT-EGFP, EGFP and Control groups revealed that the vitrified group had a significantly reduced ability to undergo first cleavage (34.4%, 63.3%, and 69.0%, respectively).

CONCLUSION

the supplement of TAT-EGFP protein into vitrification medium does not affect the viability of the oocytes whereas it improved the viability and developmental potential of oocytes after it was vitrified.

First isolation and genomic characterization of enterovirus A71 and coxsackievirus A16 from hand foot and mouth disease patients in the Lao PDR

Enterovirus A71 (EV-A71) and coxsackievirus A16 (CV-A16) are major aetiological agents of hand, foot and mouth disease in Asia. We established the first genomic characterization of strains isolated in 2011 from Lao patients. Isolates were related to EV-A71 genotype C4 and CV-A16 genotype B1a that circulated in neighbouring countries during the same period. This confirms the regional character of hand, foot and mouth disease epidemiology and makes plausible the occurrence of severe disease in the Lao population.

Outbreak of norovirus infection in a hotel in Oslo, Norway, January 2011

A total of 56 people were affected with gastroenteritis after attending a one-day meeting in a high-quality hotel in the centre of Oslo, Norway, at the end of January 2011. A complete outbreak investigation was carried out. The microbiological investigation confirmed that the outbreak was caused by norovirus. All participants at the meeting were invited by email to complete an online questionnaire asking for information on demographic data, symptoms and food consumption. The results of the epidemiological investigation of the food items served were inconclusive and the source and transmission route of this outbreak remains unclear. However, the environmental investigation highlighted several irregularities in the kitchen that may have enabled the spread of the virus. Specific cleaning procedures and rules were set up for the kitchen staff. As a consequence of this outbreak investigation, the hotel is planning to change its internal routine protocols, for example, samples of food items served at every meal during an event will be stored.

Congenital mid-line cervical cleft: case report and review of literature

Congenital Mid-line Cervical Cleft (CMCC) is a rare but interesting congenital anomaly of the neck that is frequently misdiagnosed. Much controversy exist regarding its aetiology. Embryologically, the occurrence of CMCC is thought to be due to many hypotheses that include impaired mid-line fusion of the first or second branchial arches, exteriorisation of a thyroglossal duct remnant, and or increased pressure in the cervical area from the pericardial roof in the developing embryo. Histologically, the cleft usually consists of a stratified keratinized squamous epithelium with hyperkeratosis, dermal fibrosis and little or no skin appendages. Associated clinical features could include thyroglossal duct cysts, cleft lip/mandible/sternum, cervical contractures, mandibular spurs, microgenia and or bronchogenic cysts. In this article we present a patient with CMCC. An extensive review of the literature is also included.

Prostatic androgen repressed message-1 (PARM-1) may play a role in prostatic cell immortalisation

BACKGROUND

Prostatic androgen-repressed message-1 (PARM-1) has been cloned from the prostate. The transcript of the PARM-1 gene is overexpressed during regression of the prostate after androgen withdrawal. The regulation of PARM-1 by androgens is limited to this organ. We have studied the effects of PARM-1 overexpression in malignant prostate cells.

METHODS

The PARM-1 cDNA was introduced into the rat cancer cell line MAT LyLu along with a doxycycline-dependent regulator.

RESULTS

Maximal expression of PARM-1 (fivefold induction) was achieved by incubating the cells with 2 microM doxycycline for 48 hr. A study investigating the effect of PARM-1 overexpression on the transcription of 588 genes has shown that the TLP1 gene (encoding rat telomerase protein component 1) was the most up-regulated (fourfold). In addition, a dose-dependent increase in telomerase activity was observed in cells overexpressing PARM-1. In vivo, the androgen-deprived prostate showed an increased TLP1 level and increased telomerase activity.

CONCLUSIONS

Increased telomerase activity is often associated with the immortalisation of cancer cell lines, particularly prostatic ones. This could mean that PARM-1 is involved, via increased telomerase activity, in a survival program enabling certain prostatic cells to resist apoptosis, thus conferring a selective advantage to pre-cancerous or cancerous cells.

Gastrointestinal duplications

BACKGROUND/PURPOSE

The aim of this study was to review the presentations of gastrointestinal duplication (GID) and to assess the influence of prenatal diagnosis on treatment.

METHODS

Retrospective review of all GID at 2 pediatric hospitals from 1980-2002 was conducted.

RESULTS

Seventy-three patients (M43:F30) were identified: 21 neonates, 28 infants (1 to 24 months), 15 children (1 to 10 years), 9 adolescents (>/=11 years). GID location by frequency was ileum (31.5%), ileocaecal valve (30.2%), duodenum (9.6%), stomach (8.2%), jejunum (8.2%), colon (6.8%), and rectum (5.5%). In neonates and infants, vomiting and distension were the most common presentations. Volvulus, caused by a duplication, occurred in 23.8% of neonates and caused the death of one neonate. Intussusception was identified in 10.9% of patients. In older children and adolescents, pain and vomiting were the most common associations. Six of these patients were being treated for Crohn's disease, with the diagnosis of duplication made at laparotomy. Eighteen patients had a prenatal diagnosis by ultrasound scan, with 77.2% of these asymptomatic after birth. Most prenatal diagnoses occurred after 1991 (77.8%). When comparing an earlier period (1980 to 1991; 29 patients) with the current (1992 to 2002; 44 patients), a greater proportion of the latter patients were asymptomatic (36.4 v 13.8%) and had a lower incidence of complications (volvulus/intussusception).

CONCLUSIONS

GID can lead to life-threatening complications. Prenatal diagnosis should lead to expeditious postnatal investigation and treatment before the onset of symptoms or complications. GID in older children can mimic Crohn's disease. Laparoscopy/laparotomy should be considered in patients with atypical Crohn's disease or when the diagnosis of an intraabdominal mass is unclear.

A large conductance [Ca(2+)](i)-independent K(+) channel expressed in HaCaT keratinocytes

Patch-clamp recordings were carried out in the inside-out configuration in human keratinocytes of the cell line HaCaT. Patch pipettes were filled with 150 mM KCl, 1 mM CaCl(2) and 10 mM HEPES. In symmetrical KCl solutions, single channel currents from a large conductance channel (about 170 pS) were measured. Replacement of 120 mM KCl by K-aspartate had only a minor influence on the single channel conductance and on the reversal potential. In intracellular solution in which K(+) has been replaced by Na(+) or NMDG(+), the reversal potential shifted to > + 40 mV indicating K(+) as the main charge carrier. The channels were neither dependent on intracellular Ca(2+) (between 0.8 nM and 10 micro M), ATP (at 0 and 1 mM) nor Mg(2+) (at 0 and 0.5 mM). The mean current showed an outward rectification that can be mainly attributed to the voltage dependence of the open probability. The channels displayed bursting kinetics with a mean open time of about 2 ms and closed times of about 0.2, 2 and 20 ms. The mean open probability was usually low (0.05) but increased occasionally (0.6) mainly due to a lower probability of long closings. We conclude that these K(+) channels contribute to the resting potential of human keratinocytes which may control the Ca(2+) influx and thereby their proliferation and differentiation.

Cost-effectiveness of influenza vaccination in high-risk children in Argentina

OBJECTIVES

our study aimed to evaluate the cost-effectiveness of influenza vaccination in high-risk children in Argentina.

METHODS

a decision analysis model was performed, using data from published and unpublished sources, to compare two strategies--to vaccinate or not to vaccinate. We simulated the expected consequences of vaccination on direct medical costs, related to disease management and indirect costs, related to lost parental working days (absenteeism).

RESULTS

Using base-case assumptions vaccination of high-risk children aged 6 months to 15 years old, in Argentina (estimated cohort of 1184748) would prevent 207331 cases of influenza, resulting in a reduction of 58052 days of hospitalization and 207331 outpatient visits. Vaccination would lead to net savings of US$ 11894870 per vaccinated cohort (US$ 10.04 per vaccinated child).

CONCLUSION

our economic analysis shows that in Argentina, routine vaccination of high-risk children against influenza would be cost saving for society.

Antimalarial compounds from Rhaphidophora decursiva

Bioassay-directed fractionation led to the isolation of 14 compounds, six of which possess antimalarial activity, from the dried leaves and stems of Rhaphidophora decursiva. Polysyphorin (1) and rhaphidecurperoxin (6) showed strong activities against Plasmodium falciparum. Rhaphidecursinol A (2), rhaphidecursinol B (3), grandisin (4), and epigrandisin (5) were less active against the same organism. Among the isolates, rhaphidecursinol A (2) and rhaphidecursinol B (3) were determined to be new neolignans, and rhaphidecurperoxin (6) is a new benzoperoxide. Known compounds isolated include polysyphorin (1), grandisin (4), epigrandisin (5), (+)-medioresinol, (-)-pinoresinol, (-)-syringaresinol, (+)-glaberide I, (+)-dehydrovomifoliol, (-)-liliolide, (-)-hydroxydihydrobovolide, and N-butylbenzamide, of which compound 1 appears worthy of further evaluation as an antimalarial agent. Structure elucidation and identification were accomplished by spectroscopic means including 1D and 2D NMR analyses.

A pregnane steroid from Aglaia lawii and structure confirmation of cabraleadiol monoacetate by X-ray crystallography

The pregnane steroid, (E)-aglawone, along with four known triterpenes, and a known sterol mixture were isolated from the bark of Aglaia lawii (Wight) Saldanha ex Ramamoorty (Meliaceae). The structural determination/identification was accomplished by a combination of 1D- and 2D-NMR spectroscopic techniques. The relative stereochemistry of the known triterpene, 20S,24S-epoxydammarane-3alpha,25-diol acetate, was also unequivocally determined for the first time by X-ray crystallography. The isolates were not active against various human cancer cell lines.

Economic evaluations of influenza vaccination in healthy working-age adults. Employer and society perspective

OBJECTIVE

To determine what benefits to the employer and to society are associated with influenza (flu) vaccination in healthy adults.

DESIGN AND METHODS

We performed a literature review concerning cost-benefit and cost-effectiveness evaluations of influenza vaccination in healthy, working-age adults. Up to the end of 1999, we found 6 published economic evaluations on the use of influenza vaccine in healthy, working-age adults: 3 prospective studies, 1 retrospective evaluation and 2 model-based simulations. Evaluations were performed from the perspective of an employer or society. Costs were reported in the local currency used in the published evaluation, with conversions into US dollars (when not provided in the article), for comparative purposes only, according to the exchange rates of June 8 1998.

MAIN OUTCOME MEASURES AND RESULTS

Estimations of the cost-benefit of vaccination, compared with a no vaccination strategy, varied widely from a net loss of $US106.59 per infection averted in one study to savings of varying sizes in the 5 others (savings ranged from $US2.58 per dollar invested to $US46.85 per vaccinee). Studies differed in the definition of illness and the measurement of costs associated with vaccination or illness.

CONCLUSIONS

Decision makers have not yet extended existing vaccine recommendations to cover healthy, working-age adults, partly because of the disparity among economic studies in their methods of estimating costs and measuring effects. However, the published studies seem to suggest that influenza vaccination in the healthy, working adult would be a cost-effective health intervention, at least from the perspective of an employer.

Dorsal and intermediate neuronal cell types of the spinal cord are established by a BMP signaling pathway

We have studied the role of Bmp signaling in patterning neural tissue through the use of mutants in the zebrafish that disrupt three different components of a Bmp signaling pathway: swirl/bmp2b, snailhouse/bmp7 and somitabun/smad5. We demonstrate that Bmp signaling is essential for the establishment of the prospective neural crest and dorsal sensory Rohon-Beard neurons of the spinal cord. Moreover, Bmp signaling is necessary to limit the number of intermediate-positioned lim1+ interneurons of the spinal cord, as observed by the dramatic expansion of these prospective interneurons in many mutant embryos. Our analysis also suggests a positive role for Bmp signaling in the specification of these interneurons, which is independent of Bmp2b/Swirl activity. We found that a presumptive ventral signal, Hh signaling, acts to restrict the amount of dorsal sensory neurons and trunk neural crest. This restriction appears to occur very early in neural tissue development, likely prior to notochord or floor plate formation. A similar early role for Bmp signaling is suggested in the specification of dorsal neural cell types, since the bmp2b/swirl and bmp7/snailhouse genes are only coexpressed during gastrulation and within the tail bud, and are not found in the dorsal neural tube or overlying epidermal ectoderm. Thus, a gastrula Bmp2b/Swirl and Bmp7/Snailhouse-dependent activity gradient may not only act in the specification of the embryonic dorsoventral axis, but may also function in establishing dorsal and intermediate neuronal cell types of the spinal cord.

Combined measurements of hippocampal N-acetyl-aspartate and T2 relaxation time in the evaluation of mesial temporal lobe epilepsy: correlation with clinical severity and memory performances

PURPOSE

In this study we tried to find a correlation between the clinical severity and memory performances, by comparing proton magnetic resonance (MR) spectroscopy and T2 relaxation time measurements in the hippocampi, in a homogeneous group of 27 patients with unilateral mesial temporal lobe epilepsy with ipsilateral hippocampal sclerosis on MR imaging, with a view to answer the following questions: (a) how sensitive is this approach for the assessment of the apparently normal contralateral hippocampus, (b) do the results relate to the clinical severity, and (c) does it allow evaluation of the degree of hippocampal dysfunction.

METHODS

Volume-selective proton MR spectroscopy of the head of both hippocampi was performed at 3 T, by using the PRESS sequence, with an echo time of 135 ms, to estimate NAA/(Cho + Cr) ratios. The relaxation times were measured at 0.28 T, by using a conventional Carr-Purcell-Meiboom-Gill sequence, with a repetition time of 2,000 ms, an echo time of 15 ms, and 48 echoes.

RESULTS

The combination of NAA/(Cho + Cr) ratio and T2 relaxation time values was allowed to classify contralateral hippocampus abnormalities in two groups: first, decreased NAA/(Cho + Cr) ratio with strongly increased T2 relaxation time values corresponding to abnormalities observed in sclerotic ipsilateral hippocampi; and second, decreased NAA/(Cho + Cr) ratio with normal or slightly increased T2 relaxation time values. Whereas the NAA/(Cho + Cr) ratio or T2 relaxation time value alone was not correlated with memory performances, their association shows that left hippocampal injury evaluated both by NAA and T2 relaxation time measurements was clearly correlated with verbal memory scores, and right hippocampal injury, with visual memory scores. On the other hand, the maximal seizure frequency reported by the patients was correlated with ipsilateral NAA/(Cho + Cr) ratio and T2 relaxation time values but not with contralateral results.

CONCLUSIONS

We showed that the combination of NAA and T2 relaxation time measurements can be used to examine the degree of ipsi- and contralateral hippocampal dysfunction or injuries and their relations with memory performances in the presurgical evaluation of patients.

In vitro and in vivo characterisation of [3H]ANSTO-14 binding to the sigma 1 binding sites

N-(4-phenylbutyl)-3-hydroxy-4-azahexacyclo[5.4.1.0(2,6).0(3, 10).0(5,9) .0(8,11)]dodecane (ANSTO-14) showed the highest activity for the sigma 1 site (Ki = 9.4 nM) and 19-fold sigma 1/sigma 2 selectivity. The present study showed that [3H]ANSTO-14 binds to a single high-affinity site in guinea pig brain membranes with an equilibrium Ki of 8.0 +/- 0.3 nM, in good agreement with the kinetic studies (Kd = 13.3 +/- 5.4 nM, n = 4), and a Bmax of 3.199 +/- 105 fmol/mg protein (n = 4). The in vivo biodistribution of [3H]ANSTO-14 showed a high uptake in the diencephalon. Pretreatment of rats with sigma ligands including (+)-pentazocine (sigma 1), ANSTO-14 (sigma 1), and DTG (sigma 1 and sigma 2) did not significantly reduce radiotracer uptake in the brain, but did in the spleen. A labelled metabolite was found in the liver and brain. Due to its insensitivity to sigma ligands, the accumulation of [3H]ANSTO-14 in the brain indicates high nonspecific binding. Therefore, [3H]ANSTO-14 is a suitable ligand for labelling sigma 1 sites in vitro but is not suitable for brain imaging of sigma binding sites in vivo.

[Classification of left thoracolumbar scoliosis according to its radiologic morphology and its postural geometry]

Idiopathic scoliosis is a tridimensional (3D) deformation of the spine associated with postural geometry (PG) disorganisation. Conventional classification of scoliosis is primarily based on the analysis of PA X-rays. This is a descriptive classification that forms heterogeneous groups. Diagnosis, prognosis and treatments are then developed around partial information. The goal of this project was to divide the left thoracolumbar (TLG) class in two subgroups using exhaustive analysis of the PA and lateral X-rays, and the evaluation of postural deformations. The quantification of the PG of 14 control subjects and 20 scoliotic patients (TLG) was realised using a stereovideographic approach. For each patient, PA and lateral X-rays were done using a digital X-ray apparatus. The TLG group shows common pathological characteristics but is forming a relatively heterogeneous group. When this class is divided in two subgroups, 9 postural parameters appeared to be different from the control group, each subgroup showing specific postural characteristics. The 3D quantification of pertinent radiological parameters and the PG evaluation should allow the classification of idiopathic scoliosis patients. Furthermore, these groups of patients could be characterised, in order to improve the diagnosis, the prognosis and the treatment, with a brace or surgically.

Sigma-binding site ligands inhibit K+ currents in rat locus coeruleus neurons in vitro

Biological actions of novel sigma1- and sigma2-selective binding site ligands (trishomocubanes: 4-azahexacyclo [5.4.1.0.(2,6).0(3,10).0(5,).0(8,11)]dodecanes), and the reference ligands, 1,3-di(2-tolyl)-guanidine (DTG), haloperidol, (+)-pentazocine and dextromethorphan, were studied in rat locus coeruleus neurons using intracellular and whole-cell patch clamp recordings. High concentrations of trishomocubanes produced small inward currents and affected some parameters of action potential waveforms suggesting modest potency to inhibit ionic conductances underlying action potentials. Sigma-ligands produced large inward currents in the presence of mu-opioid, alpha2-adrenoceptor and ORL1 receptor agonists. These reversed polarity near the K+ equilibrium potential, suggesting that sigma-ligands act as ligand activated K+-channel blockers or interfere with the coupling between these receptors and K+-channels. However, no correlation was found between binding affinities at sigma1- or sigma2-binding sites and potency to inhibit K+-currents, suggesting that these effects on K+-channels are not directly related to occupancy of sigma binding sites.

Carbamazepine intoxication with negative myoclonus after the addition of clobazam

We report a case a carbamazepine (CBZ) intoxication with negative myoclonus that occurred 4 weeks after clobazam (CLB) had been added to a stable regimen of CBZ and topiramate (TPM). Both CBZ and CBZ-epoxide (CBZ-E) blood levels were elevated, and the symptoms resolved quickly when CBZ dosage was reduced and CLB discontinued. CLB was reintroduced a year later with the patient's consent, and the time course of the interaction was studied: CBZ and CBZ-E levels increased slowly over 12 days. The interaction is thus probably related to the progressive increase in Nor-CLB.

Artemisinin induces omeprazole metabolism in human beings

OBJECTIVE

This study investigated whether time-dependent artemisinin pharmacokinetics correlated to CYP3A4 or CYP2C19 activity in vivo.

METHODS

Artemisinin (two oral doses per day of 250 mg) was given to nine healthy Vietnamese subjects for 7 days (day 1 to day 7). Single 20 mg doses of omeprazole were given orally on day -7, day 1, and day 7. Single doses of artemisinin and omeprazole were given in combination on day 14 after a 6-day washout period. The pharmacokinetics of artemisinin, omeprazole, hydroxyomeprazole, and omeprazole sulfone were evaluated on days -7, 1, 7, and 14. On the same days urine was collected for the determination of 6beta-hydroxycortisol and cortisol excretion.

RESULTS

Areas under plasma concentration-time curves (AUC) for artemisinin and omeprazole decreased on day 7 to 20% (95% confidence intervals, 13%, 28%) and 35% (25%, 46%), respectively, compared with values on day 1. AUC ratios for hydroxyomeprazole/omeprazole increased 2.2-fold (1.7, 2.7) on day 7 compared with values on day 1. All values were normalized at day 14. There were no significant changes in the omeprazole sulfone/omeprazole ratio or in the 6beta-hydroxycortisol/cortisol ratio between the study days. In one subject found to have poor CYP2C19 metabolization, the elimination of omeprazole increased after artemisinin exposure, with no change in the hydroxyomeprazole/omeprazole AUC ratio.

CONCLUSION

Artemisinin did not alter CYP3A4 activity, whereas an increase in CYP2C19 activity was observed. The increased elimination of omeprazole in both poor and extensive CYP2C19 metabolizers suggests artemisinin induces both CYP2C19 and another enzyme.

Ventral and lateral regions of the zebrafish gastrula, including the neural crest progenitors, are established by a bmp2b/swirl pathway of genes

A bone morphogenetic protein (BMP) signaling pathway is implicated in dorsoventral patterning in Xenopus. Here we show that three genes in the zebrafish, swirl, snailhouse, and somitabun, function as critical components within a BMP pathway to pattern ventral regions of the embryo. The dorsalized mutant phenotypes of these genes can be rescued by overexpression of bmp4, bmp2b, an activated BMP type I receptor, and the downstream functioning Smad1 gene. Consistent with a function as a BMP ligand, swirl functions cell nonautonomously to specify ventral cell fates. Chromosomal mapping of swirl and cDNA sequence analysis demonstrate that swirl is a mutation in the zebrafish bmp2b gene. Interestingly, our analysis suggests that the previously described nonneural/neural ectodermal interaction specifying the neural crest occurs through a patterning function of swirl/bmp2b during gastrulation. We observe a loss in neural crest progenitors in swirl/bmp2b mutant embryos, while somitabun mutants display an opposite, dramatic expansion of the prospective neural crest. Examination of dorsally and ventrally restricted markers during gastrulation reveals a successive reduction and reciprocal expansion in nonneural and neural ectoderm, respectively, in snailhouse, somitabun, and swirl mutant embryos, with swirl/bmp2b mutants exhibiting almost no nonneural ectoderm. Based on the alterations in tissue-specific gene expression, we propose a model whereby swirl/bmp2b acts as a morphogen to specify different cell types along the dorsoventral axis.

Artemisinin pharmacokinetics in healthy adults after 250, 500 and 1000 mg single oral doses

Eight healthy male, Vietnamese subjects were administered 1 x 250, 2 x 250, and 4 x 250 mg artemisinin capsules in a cross-over design with randomized sequence with a 7-day washout period between administrations. The inter-individual variability in artemisinin pharmacokinetics was large with parameter coefficient of variation (CV) typically between 50-70%. The parameter with the smallest variability was the elimination half-life (CV approximately equal to 30-40%). Analysis of variance indicated also a large intra-subject variability. (CV, or = 24%) for the dose-normalized area under the plasma concentration-time curve (AUC/dose). The pharmacokinetic results suggested artemisinin to be subject to high pre-systemic extraction. Artemisinin half-life could not predict the extent of in vivo exposure to the drug, there being no correlation between half-life and oral clearance. Artemisinin oral plasma clearance was about 400 L h-1 exhibiting a slight decrease with dose, although the effect was weak. Thus results from studies using different artemisinin doses may, within the studied dose range, be compared without the complication of disproportionate changes in drug exposure with varying dose levels. Half-lives appeared to increase with dose. An observed period effect in the analysis of variance was tentatively associated with time-dependency in artemisinin pharmacokinetics. There was a high correlation between artemisinin plasma concentrations determined at various time-points after drug administration and the AUCs after the 500 and 1000 mg doses, but less so after the 250 mg dose. This may show a tentative approach to assess the systemic exposure of the patients to artemisinin from the determination of artemisinin plasma concentrations in one or two plasma samples only. Artemisinin was well tolerated with no apparent dose or time dependent effects on blood pressure, heart rate or body temperature.

Artemisinin kinetics and dynamics during oral and rectal treatment of uncomplicated malaria

OBJECTIVE

To compare parasite clearance times after oral and rectal administration of artemisinin in adults with uncomplicated malaria and to relate pharmacodynamics with artemisinin kinetics and to disclose any pharmacokinetic changes during treatment.

METHODS

Thirty male Vietnamese patients with falciparum malaria were randomized to treatment with 500 mg artemisinin daily by either the oral or rectal route of administration. Parasite densities in capillary blood were determined by microscopy every 4 to 6 hours. Artemisinin plasma concentrations on the first and last day of treatment were determined by HPLC and unbound fractions in plasma were determined by ultrafiltration.

RESULTS

Mean parasite clearance times and 95% confidence intervals (95% CI) were 25 (95% CI, 16 to 33) and 29 (95% CI, 23 to 35) hours during oral and rectal treatment, respectively. The bioavailability after rectal relative to oral artemisinin was 30%. Artemisinin areas under the plasma concentration-time curve (AUC) on the fifth (last) day of oral or rectal treatment were 30% (95% CI, 4% to 56%) and 40% (95% CI, -6% to 91%), respectively, of those after the first dose. The fraction unbound in plasma was 15% (95% CI, 12% to 19%), increasing marginally during treatment. No relationship was found between main clinical end points and drug exposure, although indices for the rapidity of response onset were lower after oral treatment and correlated to unbound AUC values (rS = -0.7; p < 0.001).

CONCLUSIONS

The similarity in parasite clearance times despite lower drug levels during rectal treatment suggests that initial oral doses may be unnecessarily high. The singular time dependency of artemisinin pharmacokinetics, attributed to autoinduction of drug elimination, has possible implications for combination chemotherapy. Decreasing artemisinin concentrations during treatment may partly explain recrudescences and increase the risk for resistance development.

Occupational exposure and chronic respiratory symptoms--a population based study in Vietnam

In order to investigate the relationship between occupational exposure to dust/chemicals (toxic gases/fumes) and chronic respiratory symptoms in Vietnam, the questionnaire standardized by the American Thoracic Society was applied to 368 subjects living in Ha Thai district of Vietnam. According to the results of multiple logistic regression analyses, the odds ratios of chronic respiratory symptoms by occupational exposure are over unity, except for the relationship between chronic cough and occupational exposure to chemicals. Especially for chronic breathlessness, significantly higher odds ratios are observed among people with a history of occupational exposure to dust or chemicals: 2.925 (95% CI: 1.130-7.574) for dust, and 3.721 (95% CI: 1.412-9.803) for chemicals. As for the interaction between occupational exposure to dust and cigarette smoking, it is considered that occupational exposure leads to an increase in chronic respiratory symptoms independent of the effects of cigarette smoking.

Comparison of binding parameters of sigma 1 and sigma 2 binding sites in rat and guinea pig brain membranes: novel subtype-selective trishomocubanes

Comparisons of binding parameters of [3H](+)-pentazocine and [3H]1,3-di-o-tolylguanidine (DTG) at sigma binding sites in guinea pig and rat brain membranes demonstrated that [3H](+)-pentazocine binds to a single high-affinity site, whereas [3H]DTG binds to two high-affinity sites in both species. The Kd values of the radioligands were similar in both types of membranes. However, the density of sigma 1 sites in guinea pig was significantly higher than that of rat. Novel trishomocubanes were tested for their affinities at sigma 1 and sigma 2 binding sites in guinea pig brain membranes using [3H](+)-pentazocine and [3H]DTG as the radioligands. N-(4-Phenylbutyl)-3-hydroxy-4- azahexacyclo[5.4.1.0(2,6).0(3,10).0(5,9).0(8,11)]dodecane (ANSTO-14) showed the highest affinity for the sigma 1 site (Ki = 9.4 nM) and 19-fold sigma 1/sigma 2 selectivity, as a result of increasing the alkyl chain between the cubane moiety and the aromatic ring. N-(3'-Fluorophenyl)methyl- 3-hydroxy-4-azahexacyclo[5.4.1.0(2,6).0(3,10).0(5,9).0(8,11]dodeca ne (ANSTO-19), displayed the highest affinity for sigma 2 sites (Ki = 19.6 nM) and 8-fold sigma 2/sigma 1 selectivity due to a fluoro substitution in the meta position of the aromatic ring. These represent structurally novel lead compounds, especially for the development of selective sigma 2 receptor ligands.

Treatment of malaria in Vietnam with oral artemisinin

In this study, 638 patients with either Plasmodium falciparum or P. vivax malaria were treated with artemisinin (qinghaosu) that was isolated and formulated into tablets and capsules in Vietnam. In all cases, artemisinin treatment resulted in a rapid clearance of parasitemia and fever. Recrudescence rates were highest in those groups receiving treatment for five or less days (50%), but were between 10% and 23% for those groups receiving the drug for 5-10 days. A low recrudescent rate (9.5%) was also found when patients were treated with a combination of artemisinin for three days and tetracycline for five days. Thus, artemisinin represents a useful and economically feasible component of the malaria control program in Vietnam.

Isolation, amino acid sequence, and synthesis of dermaseptin, a novel antimicrobial peptide of amphibian skin

A 34-residue antimicrobial peptide named dermaseptin was purified to homogeneity from amphibian skin by a 3-step protocol involving molecular sieve filtration, ion-exchange chromatography, and reversed-phase high-performance liquid chromatography. The complete amino acid sequence of dermaseptin, ALWKTMLKKLGTMALHAGKAALGAAADTISQGTQ, was determined by automated Edman degradation of the peptide and of fragments generated by trypsin. Fast atom bombardment mass spectra of dermaseptin gave a protonated molecular ion m/z 3455.4 which matched the theoretical molecular weight predicted from the amino acid sequence. Dermaseptin was synthesized by the solid-phase method. The synthetic replicate was shown to be indistinguishable from natural dermaseptin with respect to chromatographic properties, amino acid sequence determination, and mass spectrometry analysis. Dermaseptin is a water-soluble, thermostable, and nonhemolytic peptide endowed with highly potent antimicrobial activity against pathogenic fungi at micromolar concentration. Circular dichroism spectra of dermaseptin in hydrophobic media indicated 80% alpha-helical conformation, and predictions of secondary structure suggested that dermaseptin can be configured as an amphiphatic alpha-helix spanning over residues 1-27, a structure that perturbs membrane functions regulating water flux.

Polymorphism in mitochondrial DNA of several Trichophyton rubrum isolates from clinical specimens

Mitochondrial DNA from six isolates of Trichophyton rubrum (a fungal pathogen of humans) was isolated, purified and digested by restriction endonucleases HindIII, HaeIII, AluI and EcoR1. The isolates could be classified into two groups according to their characteristic fragment patterns. Electron microscopy indicated that T. rubrum mitochondrial DNA are circular molecules of different lengths, 26.85 microns and 21.60 microns respectively, according to the group.