promSEMBLE: Hard Pattern Mining and Ensemble Learning for Detecting DNA Promoter Sequences

Accurate identification of DNA promoter sequences is of crucial importance in unraveling the underlying mechanisms that regulate gene transcription. Initiation of transcription is controlled through regulatory transcription factors binding to promoter core regions in the DNA sequence. Detection of promoter regions is necessary if we are to build genetic regulatory networks for biomedical and clinical applications, and for identification of rarely expressed genes. We propose a novel ensemble learning technique using deep recurrent neural networks with convolutional feature extraction and hard negative pattern mining to detect several types of promoter sequences, including promoter sequences with the TATA-box and without the TATA-box, within DNA sequences of four different species. Using extensive independent tests and previously published results, we demonstrate that our method sets a new state-of-the-art of over 98% Matthews correlation coefficient in all eight organism categories for recognizing the stretch of base pairs that code for the promoter region within DNA sequences.

Erratum: Cleft Lip/Nasal Deformities After Plastic Surgery for Unilateral Cleft Lip/Palate: A Prospective Study at a Large Hospital in Vietnam [Corrigendum]

[This corrects the article DOI: 10.2147/CCIDE.S320636.].

Erratum: Use of Septal Cartilage in Rhinoplasty to Correct Nasal Deformity After Unilateral Cleft Lip and Palate Surgery [Corrigendum]

[This corrects the article DOI: 10.2147/CCIDE.S364332.].

PCMW2D and 2D Raman correlation spectroscopy evidence for presence of spin-phonon coupling in hexagonal LuMnO3

Two-dimensional correlation spectroscopy (2D-COS) and perturbation-correlation moving window two-dimensional correlation spectroscopy (PCMW2D) analysis are performed on the temperature-dependent Raman spectra of hexagonal LuMnO₃ single crystal. Under the resonance with the on-site Mn d-d transitions, the correlation between the phonons which are relate to the vibration of Mn ions' bonds and spin-excitation peaks suggest a strong spin-phonon coupling in LuMnO₃. The PCMW2D results clearly show that the significant change in phonons and spin-excitation peaks occurs around the Néel temperature and the spin reorientation transition. The multiple components in the broad spin-excitation peaks also suggest variations in spin symmetries in the ground state. Furthermore, we propose that the 2D-COS and PCMW2D Raman correlation spectroscopies provide a simple and powerful method for investigating the couplings and the transitions, which would be very important for understanding systematically the magnetoelectric properties of multiferroic materials.

Development and Characterization of a Hydrogel Containing Curcumin-Loaded Nanoemulsion for Enhanced In Vitro Antibacteria and In Vivo Wound Healing

Curcumin (CUR) is a natural compound extracted from turmeric (Curcuma longa L.) used to cure acne, wound healing, etc. Its disadvantages, such as poor solubility and permeability, limit its efficacy. Nanoemulsion (NE)-based drug delivery systems have gained popularity due to their advantages. This study aimed to optimize a CUR-NE-based gel and evaluate its physicochemical and biological properties. A NE was prepared using the catastrophic phase inversion method and optimized using the Design Expert 12.0 software. The CUR-NE gel was characterized in terms of visual appearance, pH, drug release, antibacterial and wound healing effects. The optimal formulation contained CUR, Capryol 90 (oil), Labrasol:Cremophor RH40 (1:1) (surfactants), propylene glycol (co-surfactant), and water. The NE had a droplet size of 22.87 nm and a polydispersity index of 0.348. The obtained CUR-NE gel had a soft, smooth texture and a pH of 5.34 ± 0.05. The in vitro release of CUR from the NE-based gel was higher than that from a commercial gel with nanosized CUR (21.68 ± 1.25 µg/cm2, 13.62 ± 1.63 µg/cm2 after 10 h, respectively). The CUR-NE gel accelerated in vitro antibacterial and in vivo wound healing activities as compared to other CUR-loaded gels. The CUR-NE gel has potential for transdermal applications.

Desmodinosides A-E: New Flavonoid C-glycosides from Desmodium heterocarpon var. stigosum with hepatoprotective and antifungal activity

Five new flavonoid C-glycosides named desmodinosides A-E (1-5) and one known compound, apigenin 6-C-β-d-xylopyranosyl-2''-O-β-D-glucopyranoside (6) have been isolated from the methanol extract of the aerial parts of Desmodium heterocarpon var. stigosum. These compounds were determined by 1D and 2D-NMR and HR-MS spectroscopies. The methanol extract of this plant, in particular, demonstrated hepatoprotection and antifungal inhibition. This extract has a remarkable hepatoprotection and activity-dose response with an EC50 of 43.07 μg/mL. The hepatoprotective effect on human liver hepatoma cells (HepG2) of the isolated flavonoid C-glycosides 1-6 was observed. Desmodinosides A-C (1-3) were found to exhibit moderate hepatoprotective activity on HepG2 cells. Of these, compound 2 showed the best hepatoprotective activity with an EC50 value of 74.12 μg/mL. While compounds 1 and 3 displayed EC50 values of 271.21 and 211.99 μg/mL, respectively. Quercetin, a positive control, also caused an EC50 value of 36.42 μg/mL. In addition to having hepatoprotective effect, the methanol extract had an inhibitory effect on the growth of oomycete; it inhibited Phytophthora infestans with IC50 of 13.3 μg/mL and IC90 of 78.7 μg/mL. The oomycete inhibition was directly attributed to compounds 5 and 6, which significantly inhibited P. infestans with IC50 values of 27.4 and 24.7 μg/mL, respectively. Both 5 and 6 and methanol extract were active against P. infestanse in a dose-dependent manner. Our study demonstrated for the first time the new flavonoid C-glycosides from D. heterocarpon var. stigosum and their novel pharmacological properties. The study findings also suggest the plant extract and its metabolites could be used as a new botanical source of bioactive compounds.

Durian Shell-Mediated Simple Green Synthesis of Nanocopper against Plant Pathogenic Fungi

The synthesis of fungicides in eco-friendly and cost-effective ways is significantly essential for agriculture. Plant pathogenic fungi cause many ecological and economic issues worldwide, which must be treated with effective fungicides. Here, this study proposes the biosynthesis of fungicides, which combines copper and Cu₂O nanoparticles (Cu/Cu₂O) synthesized using durian shell (DS) extract as a reducing agent in aqueous media. Sugar and polyphenol compounds contained in DS, as the main phytochemicals acting in the reduction procedure, were extracted under different temperatures and duration conditions to obtain the highest yields. We confirmed the extraction process performed at 70 °C for 60 min to be the most effective in extracting sugar (6.1 g/L) and polyphenols (22.7 mg/L). We determined the suitable conditions for Cu/Cu₂O synthesis using a DS extract as a reducing agent for a synthesis time of 90 min, a volume ratio of DR extract/Cu²⁺ of 15:35, an initial pH solution of 10, a synthesis temperature of 70 °C, and a CuSO₄ concentration of 10 mM. The characterization results of as-prepared Cu/Cu₂O NP showed a highly crystalline structure of Cu₂O and Cu with sizes estimated in the range of 40-25 nm and 25-30 nm, respectively. Through in vitro experiments, the antifungal efficacy of Cu/Cu₂O against Corynespora cassiicola and Neoscytalidium dimidiatum was investigated by the inhibition zone. The green-synthesized Cu/Cu₂O nanocomposites, which are potential antifungals against plant pathogens, exhibited excellent antifungal efficacy against both Corynespora cassiicola (MIC = 0.25 g/L, the diameter of the inhibition zone was 22.00 ± 0.52 mm) and Neoscytalidium dimidiatum (MIC = 0.0625 g/L, the diameter of the inhibition zone was 18.00 ± 0.58 mm). Cu/Cu₂O nanocomosites prepared in this study could be a valuable suggestion for the control of plant pathogenic fungi affecting crop species globally.

Regulation of Off-track bidirectional signaling by Semaphorin-1a and Wnt signaling in the Drosophila motor axon guidance

Off-track receptor tyrosine kinase (OTK) has been shown to play an important role in the Drosophila motor axon pathfinding. The results of biochemical and genetic interactions previously suggested that OTK acts as a component of Semaphorin-1a/Plexin A (Sema-1a/PlexA) signaling during embryonic motor axon guidance and further showed that OTK binds to Wnt family members Wnt2 and Wnt4 and their common receptor Frizzled (Fz). However, the molecular mechanisms underlying the motor axon guidance function of OTK remain elusive. Here, we conclude that OTK mediates the forward and reverse signaling required for intersegmental nerve b (ISNb) motor axon pathfinding and we also demonstrate that the loss of two copies of Sema-1a synergistically enhances the bypass phenotype observed in otk mutants. Furthermore, the amorphic wnt2 mutation resulted in increased premature branching phenotypes, and the loss of fz function caused a frequent inability of ISNb motor axons to defasciculate at specific choice points. Consistent with a previous study, wnt4 mutant axons were often defective in recognizing target muscles. Interestingly, the bypass phenotype of otk mutants was robustly suppressed by loss of function mutations in wnt2, wnt4, or fz. In contrast, total ISNb defects of otk were increased by the loss-of-function alleles in wnt2 and wnt4, but not fz. These findings indicate that OTK may participate in the crosstalk between the Sema-1a/PlexA and Wnt signaling pathways, thereby contributing to ISNb motor axon pathfinding and target recognition.

Use of Septal Cartilage in Rhinoplasty to Correct Nasal Deformity After Unilateral Cleft Lip and Palate Surgery

Background

The most common facial defect is the congenital cleft lip (CL), which can occur with or without a cleft palate (CP). Patients need primary plastic surgery for rehabilitation and esthetics; nevertheless, secondary abnormalities of the lip and nose may develop after primary surgery. These deformities are complex and involve all tissue layers, including the skeletal platform, inner lining, osseocartilaginous structure, and overlying skin. This study evaluated the results of nasal deformity rhinoplasty using septal cartilage in patients with nasal deformities after plastic surgery for unilateral CL and CP.

Methods

This retrospective study was conducted on 21 patients with secondary unilateral CL nasal deformity between June 2015 and August 2016. All patients underwent rhinoplasty with the use of septal cartilage grafts. Pre- and post-operative nasal forms were measured.

Results

The patients had cosmetic problems and impaired nasal airflow due to distorted anatomy. The postoperative nasal forms were improved in all patients. Rhinoplasty using septal cartilage effectively increased the height of the columella and nose and improved the balance of the base width and the length of both sides of the nose. Excellent results were achieved in 18 patients. Three patients showed good results. No patient showed a fair result.

Conclusion

This study demonstrated an effective correction of esthetic deformities and significant improvement in airway patency. A long-term longitudinal study is still required to evaluate the influence of septal cartilage harvesting on face and nasal development until children reach their late teens.

Availability, prices and affordability of essential medicines: A cross-sectional survey in Hanam province, Vietnam

OBJECTIVE

To measure medicines' prices, availability, and affordability in Hanam, Vietnam.

METHODS

The standardized methodology developed by the World Health Organization (WHO) and Health Action International was used to survey 30 essential medicines (EMs) in 30 public health facilities and 35 private medicine outlets in 2020. The availability of medicine was computed as the percentage of health facilities in which this medicine was found on the data-collection day. International reference prices (IRPs) from Management Sciences for Health (2015) were used to compute Median Price Ratio (MPR). The affordability of treatments for common diseases was computed as the number of days' wages of the lowest-paid unskilled government worker needed to purchase medicines prescribed at a standard dose. Statistic analysis was done using R software version 4.1.1.

RESULTS

The mean availability of originator brands (OBs) and lowest-priced generics (LPGs) was 0.7%, 63.2% in the public sector, and 13.7%, 47.9% in the private sector, respectively. In private medicine outlets, the mean availability of both OBs and LPGs in urban areas was significantly higher than that in rural areas (p = 0.0013 and 0.0306, respectively). In the public sector, LPGs' prices were nearly equal to their IRPs (median MPRs = 0.95). In the private medicine outlets, OBs were generally sold at 6.24 times their IRPs while this figure for LPGs was 1.65. The affordability of LPGs in both sectors was good for all conditions, with standard treatments costing a day's wage or less.

CONCLUSION

In both sectors, generic medicines were the predominant product type available. The availability of EMs was fairly high but still lower than WHO's benchmark. A national-scale study should be conducted to provide a comprehensive picture of the availability, prices, and affordability of EMs, thereby helping the government to identify the urgent priorities and improving access to EMs in Vietnam.

Access to essential medicines for children: a cross-sectional survey measuring medicine prices, availability and affordability in Hanam province, Vietnam

OBJECTIVE

To identify the availability, prices and affordability of essential medicines for children (cEMs) in Hanam province, Vietnam.

DESIGN

Cross-sectional study.

SETTING

One city and five districts of Hanam province.

PARTICIPANTS

66 public health facilities and 66 private drugstores.

PRIMARY AND SECONDARY OUTCOME MEASURES

The standardised methodology of the WHO and Health Action International was used to investigate 30 paediatric essential medicines. For each medicine, data were collected for two products: the lowest-priced medicine (LPM) and the highest-priced medicine (HPM). The availability of medicine was computed as the percentage of facilities in which this medicine was found on the day of data collection. Median prices of individual medicines were reported in local currency. Affordability was calculated as the number of days' wages required for the lowest-paid unskilled government worker to purchase standard treatments for common diseases. Data were analysed using R software V.4.1.0.

RESULTS

The mean availability of LPMs in the private sector (33.2%, SD=38.0%) was higher than that in the public sector (24.9%, SD=39.4%) (p<0.05). The mean availability of HPMs was extremely low in both sectors (11.3% and 5.8%, respectively). The mean availability of cEMs in urban areas was significantly higher than that in rural areas (36.5% and 31.6%, respectively, p<0.05). In the public sector, the prices of LPMs were nearly equal to the international reference prices (IRPs). In the private sector, LPMs were generally sold at 4.06 times their IRPs. However, in both sectors, the affordability of LPMs was reasonable for most conditions as standard treatments only cost a day's wage or less.

CONCLUSION

The low availability was the main reason hindering access to cEMs in Hanam, especially in the countryside. A national study on cEMs should be conducted, and some practical policies should be promulgated to enhance access to cEMs.

New triterpene sulfates from Vietnamese red alga Tricleocarpa fragilis and their α-glucosidase inhibitory activity

Three new compounds (methyl-3β,25-dihydroxycycloart-23-en-29-oate 3-sulfate (1), methyl-3β-hydroxy-25-methoxycycloart-23-en-29-oate 3-sulfate (2) and 3β-hydroxy-25-methoxycycloart-23-ene 3-sulfate (3)) and a known one (3β-hydroxycycloart-24-en-23-one 3-sulfate (4)) were isolated from Vietnamese red alga Tricleocarpa fragilis. All isolated compounds 1-4 showed potent inhibitory activity against yeast α-glucosidase with IC₅₀ values of 16.62 ± 2.80, 36.34 ± 4.04, 30.19 ± 5.01 and 6.52 ± 0.17 µM, respectively. The docking data showed that the substitutions at C-3 and the differences in the side chain of cycloartane-skeleton could influence the interaction of molecule with enzyme, which was consistent with the experimental findings.[Formula: see text].

COVID-19 restrictions and recreational fisheries in Ontario, Canada: Preliminary insights from an online angler survey

The COVID-19 pandemic and corresponding public health mitigation strategies have altered many facets of human life. And yet, little is known about how public health measures have impacted complex socio-ecological systems such as recreational fisheries. Using an online snowball survey, we targeted resident anglers in Ontario, Canada, to obtain preliminary insights on how the pandemic has impacted recreational fishing and related activity. We also explored angler perspectives on pandemic-related restrictions and other aspects of fisheries management. Our results point to the value of recreational fisheries for the mental and physical well-being of participants, as well as the value and popularity of outdoor recreation during a pandemic. Although angling effort and fish consumption appeared to decline during the early phases of the pandemic, approximately 21 % of the anglers who responded to our survey self-identified as new entrants who had begun or resumed fishing in that time. Self-reported motivations to fish during the pandemic suggest that free time, importance to mental and physical health, and desires for self-sufficiency caused some anglers to fish more, whereas a lack of free time, poor or uncertain accessibility, and perceived risks caused some anglers to fish less. Respondents also expressed their desires for more clear and consistent communication about COVID-19 fishing restrictions from governments, and viewed angling as a safe pandemic activity. Information on recreational angler behaviours, motivations, and perspectives during the pandemic may prove valuable to fisheries managers and policy makers looking to optimize their strategies for confronting this and other similar crises.

Cleft Lip/Nasal Deformities After Plastic Surgery for Unilateral Cleft Lip/Palate: A Prospective Study at a Large Hospital in Vietnam

INTRODUCTION

Congenital cleft lip, with or without cleft palate, is the most common deformity of the face. Primary plastic surgery for rehabilitation and esthetics is important for patients and their parents; however, secondary deformities of the lip and nose can occur after the primary surgery. Therefore, we performed assessment of secondary cleft lip/nasal deformities to aid in planning of surgical repair of these deformities.

MATERIALS AND METHODS

Forty-six patients with unilateral cleft lip, with or without cleft palate, were operated with different techniques and examined post-surgery at the Department of Maxillofacial Surgery, University of Medicine and Pharmacy Hospital and Center of Odonto-Stomatology, Hue Central Hospital. They were assessed according to Motier's post-operative evaluation scale (1997), including the red lip, white lip, scars, and nose.

RESULTS

V notch and defect on the shift line were the most common deformities on the red lip (52.2%). About 34.8% of the patients had a short white lip on the cleft side. Straight and prominent scars were observed in 52.2% of the patients. The most common deformities of the nose were septal deviation (78.3%), followed by defects in the upper part of the nostril contour (78.3%), narrow sill (52.2%), and low position of the ala (47.8%).

CONCLUSION

Secondary cleft lip/nasal deformities are unavoidable. It is necessary to develop a plan for surgical repair of these deformities. There is no single method of cleft lip surgery that gives perfect results. Therefore, clinicians choose a combination of methods to bring optimal results for each patient.

Experimental and numerical simulation on dynamics of a moored semi-submersible in various wave directions

A moored floating platform has great potential in ocean engineering applications because the mooring system is necessary to keep a floating platform in the station. It relates directly to operational efficiency and safety of a floating platform. This study presents a comprehensive assessment of the dynamics of a moored semi-submersible in waves by performing model test and numerical simulation. First, a three-dimensional panel method was used to estimate the motion of a moored semi-submersible in waves. A semi-submersible is modelled as a rigid body with six degrees-of-freedom (6DOF) motion. Dynamic response analysis of a semi-submersible is performed in regular wave and irregular wave. Second, the model test is performed in various wave directions. An Optical-based system is used to measure 6DOF motion of a semi-submersible. Numerical results are compared with the experimental results in various wave directions. Wavelength and wave direction showed significant effects on the motion response of a semi-submersible in regular wave. Third, to obtain a better understanding of response frequencies, the time histories of motion responses in irregular wave are converted from the time domain to the frequency domain. Effects of the wave frequency component on motion responses and mooring dynamics are analyzed. Motion spectrum in irregular wave has a strong response to the natural frequency of a moored semi-submersible and the peak of wave frequency. Finally, exceedance probability is estimated to predict probable extreme values of motion responses of a moored semi-submersible as well as mooring dynamics.

Temporalis Muscle Flap for the Immediate Reconstruction of Oral Defects after Oncologic Resection

An oral defect after oncologic resection, especially in the upper jaw, is an extremely complex problem in terms of reconstructive surgery. Herein, we report 2 patients who were diagnosed with oral mucosal squamous cell carcinoma. In one patient, the lesion was present on the right side of the hard palate, invading the maxillary bone. In the other patient, the lesion was present in the left retromolar trigone region. Reconstruction of the postsurgical defects was successfully done using a temporalis muscle flap. Both patients were discharged after ensuring the absence of any postsurgical complications. Furthermore, the postoperative functional and esthetic outcomes were adequate. These case reports highlight the usefulness and reliability of a temporalis muscle flap for the immediate reconstruction of oral and maxillary defects after oncologic resection.

Alone Together

In this article, based on my ethnographic experience of Ho Chi Minh City’s lockdown, I argue that COVID-19 acted as an accelerator of intimacies, allowing people to negotiate alternative forms of sociality both within and outside the domestic space. On the one hand, by confining people at home it brought to light social and housing inequalities in urban Vietnam. On the other, it forced people to find imaginative ways to cope with social-distancing protocols. Since mobility during lockdown was limited, the normatively private space of the house became an incubator for social life, affording people – even those outside the circle of close friends and relatives – the opportunity to be alone together, sharing their temporary stuckness to challenge normative patterns of intimacy and sexuality.

Enhancement of Rhodamine B Degradation by Ag Nanoclusters-Loaded g-C₃N₄ Nanosheets

In this paper, silver (Ag) nanoclusters-loaded graphitic carbon nitride (g-C₃N₄) nanosheets are synthesized and their physical properties as well as photocatalytic activities are systematically investigated by different techniques. The existence of Ag atoms in the form of nanoclusters (NCs) rather than well-crystallized nanoparticles are evidenced by X-ray diffraction patterns, SEM images, and XPS spectra. The deposition of Ag nanoclusters on the surface of g-C₃N₄ nanosheets affect the crystal structure and slightly reduce the band gap energy of g-C₃N₄. The sharp decrease of photoluminescence intensity indicates that g-C₃N₄/Ag heterojunctions successfully prevent the recombination of photo-generated electrons and holes. The photocatalytic activities of as-synthesized photocatalysts are demonstrated through the degradation of rhodamine B (RhB) solutions under Xenon lamp irradiation. It is demonstrated that the photocatalytic activity depends strongly on the molar concentration of Ag⁺ in the starting solution. The g-C₃N₄/Ag heterojunctions prepared from 0.01 M of Ag⁺ starting solution exhibit the highest photocatalytic efficiency and allow 100% degradation of RhB after being exposed for 60 min under a Xenon lamp irradiation, which is four times faster than that of pure g-C₃N₄ nanosheets.

Immunocytochemical characterization of viruses and antigenic macromolecules in viral vaccines

Gold immunolabeling combined with negative staining (GINS) provides a valuable immunocytochemical approach that allows a direct ultrastructural definition of all viral vaccine constituents that share common antigenic features with pathogenic viral particles. These results have implications for the development of viral vaccines since it has been demonstrated that incomplete viral particles such as natural empty capsides and Rotavirus-like particles lacking the infective genome are potential candidates for the production of neutralizing antibodies. Furthermore comparative results of the application of GINS to either inactivated vaccines or unfixed samples provide direct evidence that even after inactivation specific antigenic sites are still available for gold immunolabeling.

The epidemiology and disease burden of rotavirus in Vietnam: sentinel surveillance at 6 hospitals

The disease burden of rotavirus diarrhea in Vietnam was assessed by surveillance of children <5 years old who were hospitalized for diarrhea at 3 centers in the north and 3 centers in the south. Rotavirus was identified in 56% (range, 47%-60%) of the 5768 patients surveyed between July 1998 and June 2000. G-typing of the first 224 strains indicated that only 2% were non-typeable, 9% were in mixed infections, and the remainder were of the common serotypes G1, G2, G3, G4, and G9. In Vietnam, diarrhea accounts for 9880 deaths per year, which is approximately 15% of all deaths among children <5 years old, or 6.5 deaths per 1000 children. If even 50% of these diarrhea-related deaths in Vietnam were due to rotavirus, the number would represent 4%-8% of all deaths among children <5 years old, 2700-5400 rotavirus-related deaths per year, and 1 death per 280-560 children during the first 5 years of life. Thus, the disease burden of rotavirus in Vietnam is substantial, and programs to encourage the use of oral rehydration should be encouraged while efforts to develop vaccines continue.

Acute management of dengue shock syndrome: a randomized double-blind comparison of 4 intravenous fluid regimens in the first hour

Dengue hemorrhagic fever is an important cause of morbidity among Asian children, and the more severe dengue shock syndrome (DSS) causes a significant number of childhood deaths. DSS is characterized by a massive increase in systemic capillary permeability with consequent hypovolemia. Fluid resuscitation is critical, but as yet there have been no large trials to determine the optimal fluid regimen. We undertook a randomized blinded comparison of 4 fluids (dextran, gelatin, lactated Ringer's, and "normal" saline) for initial resuscitation of 230 Vietnamese children with DSS. All the children survived, and there was no clear advantage to using any of the 4 fluids, but the longest recovery times occurred in the lactated Ringer's group. The most significant factor determining clinical response was the pulse pressure at presentation. A comparison of the colloid and crystalloid groups suggested benefits in children presenting with lower pulse pressures who received one of the colloids. Further large-scale studies, stratified for admission pulse pressure, are indicated.

A pharmacokinetic and pharmacodynamic study of artesunate for vivax malaria

To investigate the pharmacokinetic and pharmacodynamic properties of artesunate (ARTS) and its active metabolite dihydroartemisinin (DHA) in Plasmodium vivax infections, 12 male Vietnamese adults with slide-positive vivax malaria received either intravenous ARTS (120 mg; group 1) or oral ARTS (100 mg; group 2) with the alternative preparation given 8 hr later in a randomized, open, cross-over study. Following intravenous injection, ARTS had a peak plasma drug concentration (Cmax) of 35.6 microM (13.7 mg/L), an elimination half-life (t1/2) of 2.2 min, a clearance (CL) of 3.0 L/hr/kg, and a volume of distribution (V) of 0.16 L/kg. Dihydroartemisinin had a Cmax of 7.7 microM (2.2 mg/L), a tmax of 8 min, a t1/2 of 37 min, an apparent CL of 1.1 L/hr/kg, and an apparent V of 0.9 L/kg. Following oral ARTS, the mean relative bioavailability of DHA was 85%, the Cmax was 3.0 microM (0.85 mg/L), the tmax was 75 min, and t1/2 was 40 min. The mean time to 50% reduction in the parasite count (PCT50) and median fever clearance time were 3 hr and 16 hr, respectively. Following intravenous ARTS (group 1), the PCT50 for total parasites, rings, trophozoites, and gametocytes was 3.3 hr, 3.2 hr, 4.0 hr, and 3.6 hr, respectively. This study confirms that ARTS is effective against P. vivax, with rapid clearance of sexual and asexual forms of the parasite. Artesunate is a suitable initial treatment for vivax malaria, or when the plasmodial species cannot be reliably identified.

Single dose artemisinin-mefloquine versus mefloquine alone for uncomplicated falciparum malaria

The efficacy of the combination of a single oral dose of 500 mg artemisinin with a single 500 mg oral dose of mefloquine (AM) in the treatment of uncomplicated falciparum malaria was compared to mefloquine therapy alone (M) in a double-'blind' randomized study in an endemic area in the south of Viet Nam where single low dose treatment was employed and where mefloquine had been recently introduced. 231 patients, 117 AM and 114 M, were studied. Failure of therapy occurred in 1 AM patient and in 3 M patients. The radical cure rate was 84% for the AM regimen and 65% for the M regimen (P = 0.002). Recrudescence (including an unknown percentage of reinfections) occurred in 15% of AM patients and in 30% of M patients (P = 0.01). The mean parasite clearance time was 40 h (SD = 16) for AM and 60 h (SD = 27) for the M regimen (P = 0.0001). No effect of artemisinin was noted on gametocytes present on admission, but new gametocytes developed less frequently in the AM group. The addition of a single dose of 500 mg artemisinin to 500 mg mefloquine increased the efficacy and reduced the rate of recrudescence, but this regimen was not adequate and, for short course regimens, more doses of artemisinin as well as higher, doses of mefloquine should be studied.

Freeze-etching and freeze-fracture structural features of cell envelopes in mycobacteria and leprosy derived corynebacteria

The structural properties of the cell wall and cell membrane of several mycobacteria and of Leprosy Derived Corynebacteria are investigated by freeze-etching and freeze-fracture. In all cases the freeze-fracture split the cell wall in two asymmetric halves. The cell wall fracture faces of the mycobacteria are characterized by a filamentous network which vary with respect to the amount and complexity among microorganism of the same species and even more of different species. In LDC the structure organization of the cell wall and cell membrane differs from that of mycobacteria. The most stricking difference is the presence on the fracture faces of the LDC cell wall of different classes of particulated entities of yet unknown nature. In the mycobacteria and LDC the periseptal annuli likely provide a potential frame for cell envelope and cell membrane assembly.