Efficacy and safety of methylene blue in the treatment of malaria: a systematic review.

BACKGROUND: Methylene blue (MB) was the first synthetic antimalarial to be discovered and was used during the late 19th and early 20th centuries against all types of malaria. MB has been shown to be effective in inhibiting Plasmodium falciparum in culture, in the mouse model and in rhesus monkeys. MB was also shown to have a potent ex vivo activity against drug-resistant isolates of P. falciparum and P. vivax. In preclinical studies, MB acted synergistically with artemisinin derivates and demonstrated a strong effect on gametocyte reduction in P. falciparum. MB has, thus, been considered a potentially useful partner drug for artemisinin-based combination therapy (ACT), particularly when elimination is the final goal. The aim of this study was to review the scientific literature published until early 2017 to summarise existing knowledge on the efficacy and safety of MB in the treatment of malaria. METHODS: This systematic review followed PRISMA guidelines. Studies reporting on the efficacy and safety of MB were systematically searched for in relevant electronic databases according to a pre-designed search strategy. The search (without language restrictions) was limited to studies of humans published until February 2017. RESULTS: Out of 474 studies retrieved, a total of 22 articles reporting on 21 studies were eligible for analysis. The 21 included studies that reported data on 1504 malaria patients (2/3 were children). Older studies were case series and reports on MB monotherapy while recent studies were mainly controlled trials of combination regimens. MB was consistently shown to be highly effective in all endemic areas and demonstrated a strong effect on P. falciparum gametocyte reduction and synergy with ACT. MB treatment was associated with mild urogenital and gastrointestinal symptoms as well as blue coloration of urine. In G6PD-deficient African individuals, MB caused a slight but clinically non-significant haemoglobin reduction. CONCLUSIONS: More studies are needed to define the effects of MB in P. falciparum malaria in areas outside Africa and against P. vivax malaria. Adding MB to ACT could be a valuable approach for the prevention of resistance development and for transmission reduction in control and elimination programs. SYSTEMATIC REVIEW REGISTRATION: This study is registered at PROSPERO (registration number CRD42017062349 ).

Dynamics of dual-polarization VCSEL-based optical frequency combs under optical injection locking.

The present experimental work studies the dynamics of dual-polarization optical frequency combs (OFCs) based on gain switching (GS) vertical-cavity surface-emitting laser (VCSEL) diodes under optical injection locking (OIL). This study presents two main results. First, we have obtained an overall comb formed by two orthogonally polarized sub-combs with comparable span and power. The overall comb shows enhanced optical span and flatness and high coherence between its modes. The second result is that we have been able to control the polarization state of the overall comb by tuning the polarization state of the injected light by locking the same single teeth of the comb. This produces an overall comb with single polarization that is parallel or orthogonal. These are novel findings that provide for the development of efficient and compact OFCs based on GS VCSEL sources with versatile polarization dynamics.

Temperature characteristics of surface micromachined MEMS-VCSEL with large tuning range.

Several Applications for tunable laser diodes have strict constraints in terms of overall power consumption. Furthermore, the implementation in harsh environments with large temperature fluctuations is necessary. Due to the constraint in power consumption, the application of active cooling might not be an option. For this reason we investigate the temperature characteristics of an electrically pumped MEMS-VCSEL with wide continuous wavelength tuning. For the first time, a mode hop free single mode (side mode suppression ratio (SMSR) > 40dB) tuning range of 45nm at 70°C is demonstrated with a MEMS-VCSEL. An increase of the tuning range from 85nm at 20°C to 92nm at 40°C is measured and explained. In contrast to fixed wavelength VCSEL, the investigated device shows a negative temperature induced wavelength shift of -4.5nmK(-1), which is caused by the MEMS-mirror. At 1560nm, the fibre-coupled optical output power is above 0.6mW over the entire temperature range between 20°C to 70°C and shows a maximum of > 3mW at 20°C.

A R59W mutation in human protoporphyrinogen oxidase results in decreased enzyme activity and is prevalent in South Africans with variegate porphyria.

Variegate porphyria (VP), a low-penetrant autosomal dominant inherited disorder of haem metabolism, is characterised by photosensitivity (Fig. 1) and a propensity to develop acute neuropsychiatric attacks with abdominal pain, vomiting, constipation, tachycardia, hypertension, psychiatric symptoms and, in the worst cases, quadriplegia. Acute attacks, often precipitated by inappropriate drug therapy, are potentially fatal. While earlier workers thought the distal haem biosynthetic enzyme ferrochelatase may be involved in the genesis of VP, it was shown in the early 1980's, and is now accepted, that VP is associated with decreased protoporphyrinogen oxidase activity (PPO) (E.C.1.3.3.4). VP prevalence is much higher in South Africa than elsewhere; probably due to a founder effect with patients descending from a 17th century Dutch immigrant. PPO cDNAs from Bacillus subtilis, Myxococcus xanthus, human placenta and mouse liver have been cloned, sequenced and expressed. Human and mouse cDNAs consist of open reading frames 1431 nucleotides long, encoding a 477 amino acid protein. The human PPO gene contains thirteen exons, spanning approximately 4.5 kb. We have identified a C to T transition in codon 59 (in exon 3) resulting in an arginine to tryptophan substitution (R59W). A protein expressed from an in vitro-mutagenized PPO construct exhibits substantially less activity than the wild type. The R59W mutation was present in 43 of 45 patients with VP from 26 of 27 South African families investigated, but not in 34 unaffected relatives or 9 unrelated British patients with PPO deficiency. Since at least one of these families is descended from the founder of South African VP, this defect may represent the founder gene defect associated causally with VP in South Africa.

Determinants of the use of insecticide-treated mosquito nets in pregnant women: a mixed-methods study in Ghana.

BACKGROUND: Malaria in pregnancy remains a significant cause of morbidity and mortality, affecting the highly endemic countries of sub-Saharan Africa (SSA). Insecticide-treated nets (ITNs) are effective for malaria prevention. However, poor adherence in SSA remains a challenge. METHODS: We conducted a standard questionnaire survey among 710 pregnant women from 37 primary care clinics in the Upper West Region of Ghana from January through May 2019. Using a sequential explanatory design, we integrated the survey data from six focus group discussions with pregnant women. RESULTS: While 67% of women had some general knowledge about malaria prevention, only 19% knew the specific risks in pregnancy. Determinants of ITN use included ITN ownership (odds ratio [OR] 2.4 [95% confidence interval {CI} 1.3 to 4.4]), good maternal knowledge of the risks of malaria in pregnancy (OR 2.4 [95% CI 1.3 to 4.3]) and more antenatal care (ANC) contacts (OR 1.3 [95% CI 1.0 to 1.5)]. Focus group discussions showed that non-use of ITNs resulted from inappropriate hanging infrastructure, a preference for other malaria prevention alternatives, allergy and heat. CONCLUSIONS: Specific maternal knowledge of malaria risks in pregnancy was low and influenced the regular use of ITNs. Community and ANC-based malaria interventions should prioritize increasing knowledge of the specific risks of malaria.

Surface micromachined tunable 1.55 µm-VCSEL with 102 nm continuous single-mode tuning.

For the first time a vertical-cavity surface-emitting laser (VCSEL) with a single-mode wavelength-tuning over 102 nm in the range of 1550 nm is demonstrated. The fiber-coupled optical output power has a maximum of 3.5 mW and is > 2 mW over the entire tuning range. The sidemode suppression ratios are > 45 dB. The wavelength tuning is achieved with the micro-electro mechanical actuation of a mirror membrane fabricated with surface micro-machining for on-wafer mass production. The mirror membrane consists of low cost dielectric materials (SiOx/SiNy) deposited with low temperature (< 100°C) Plasma Enhanced Chemical Vapor Deposition (PECVD).

The expression of protoporphyrinogen oxidase in human tissues.

Protoporphyrinogen oxidase is the penultimate enzyme in the haem biosynthetic pathway. In this study, the expression of protoporphyrinogen oxidase in a variety of human organs has been documented by immunohistochemical means at the light microscopy level in order to shed light on its inter- and intra-organ distribution. The expression varied amongst organs and the various cell types within an organ. The pattern of staining generally reflected presumed metabolic functionality and haem demand. Strongest staining was noted in hepatocytes, proximal convoluted tubules of the kidney, serous cells of the peribronchial gland in the lung, parietal cells of the stomach, tips of the villi in the small intestine and interstitial cells of the testis. Our results suggest that there are some significant sites of haem synthesis in addition to the liver and bone marrow, and should be borne in mind in studies related to haem or porphyrin dynamics and flux.

Molecular characterization of erythropoietic protoporphyria in South Africa.

BACKGROUND: Erythropoietic protoporphyria (EPP) results from a partial deficiency of ferrochelatase (FECH). Clinical expression normally requires coinheritance of a common hypomorphic FECH allele (IVS3-48C) in trans to a deleterious (primary) FECH mutation. OBJECTIVES: To characterize South African subjects with EPP, by identification and assessment of FECH sequence variations, including the IVS3-48C polymorphism. METHODS: Polymerase chain reaction amplification, single-strand conformational polymorphism analysis and restriction endonuclease analysis were employed to identify and determine the frequencies of FECH sequence variations, including the IVS3-48C polymorphism, in a study cohort of symptomatic and asymptomatic South African EPP family members, and a matched control cohort. RESULTS: We identified 29 patients from 18 families. With the exception of one family, who may represent a phenocopy of EPP, the presentation of EPP was typical. All were of European immigrant stock, and we have not identified EPP in other ethnic groups. Ten sequence variations were identified, including four apparent disease-causing mutations, the IVS3-48T/C polymorphism and five further polymorphisms. The molecular basis of EPP was established for 15 of the 17 families. A 5-bp deletion in exon 7 (757_761delAGAAG) was present in 12 of these families and haplotype studies in these families suggested a single mutational event and thus a local founder effect for this deletion. The other mutations were family specific and included two previously described splice-site mutations (IVS3+2T>G and IVS7+1G>A) and a novel 7-bp deletion in exon 4 (356_362delTTCAAGA). CONCLUSIONS: The IVS3-48C allele appears to modulate the phenotypic expression of EPP in the South African EPP cohort as observed in other populations.

Allosteric inhibition of human lymphoblast and purified porphobilinogen deaminase by protoporphyrinogen and coproporphyrinogen. A possible mechanism for the acute attack of variegate porphyria.

Variegate porphyria (VP) is characterized by photocutaneous lesions and acute neuropsychiatric attacks. Decreased protoporphyrinogen oxidase activity results in accumulation of protoporphyrin (ogen) IX and coproporphyrin (ogen) III. During acute attacks delta-aminolevulinic acid and porphobilinogen also increase, suggesting that porphobilinogen deaminase (PBG-D) may be rate limiting. We have examined the effects of porphyrinogens accumulating in VP on PBG-D activity in Epstein-Barr virus-transformed lymphoblast sonicates from 12 VP and 12 control subjects. Protoporphyrinogen oxidase activity was decreased and protoporphyrin increased in VP lymphoblasts. PBG-D in control lymphoblasts obeyed Michaelis-Menten kinetics (Vmax 28.7 +/- 1.8 pmol/mg per h, Hill coefficient 0.83 +/- 0.07). VP sonicates yielded sigmoidal substrate-velocity curves that did not obey Michaelis-Menten kinetics. Vmax was decreased (21.2 +/- 2.0 pmol/mg per h) and the Hill coefficient was 1.78 +/- 0.17. Addition of protoporphyrinogen IX and coproporphyrinogen III to control sonicates yielded sigmoidal PBG-D substrate-velocity curves and decreased PBG-D Vmax. Addition of porphyrins or uroporphyrinogen III did not affect PBG-D activity. Removal of endogenous porphyrin (ogens) from VP sonicates restored normal PBG-D kinetics. Purified human erythrocyte PBG-D obeyed Michaelis-Menten kinetics (Vmax 249 +/- 36 nmol/mg per h, Km 8.9 +/- 1.5 microM, Hill coefficient 0.93 +/- 0.14). Addition of protoporphyrinogen yielded a sigmoidal curve with decreased Vmax. The Hill coefficient approached 4. These findings provide a rational explanation for the increased delta-aminolevulinic acid and porphobilinogen during acute attacks of VP.

Rapid proliferation of B cells from adenoids in response to Epstein-Barr virus infection.

EBV is a human tumor virus that is associated with different types of tumors. A unique feature of EBV is its capability to infect and immortalize human B cells both in vivo and in vitro. In cell culture, this progress is termed immortalization and infected B cells grow out to permanent, so-called lymphoblastoid cell lines. During our experiments, we observed that B lymphocytes derived from adenoids are infected efficiently by EBV and proliferate much more rapidly than any other known type of B cell. High concentrations of adhesion molecules and of CD21, the EBV receptor, present on these cells may account for this phenomenon. Adenoid B cells may therefore represent a particular subpopulation of preactivated B lymphocytes that can greatly simplify and enhance the production of lymphoblastoid cell lines for, e.g., antigen-presenting cells for gene therapeutic approaches and similar applications.

Constitutive and modulated cytokine expression in two permanent human bone marrow stromal cell lines.

We present a detailed analysis of cytokine expression patterns of the two permanent human bone marrow stromal cell lines, L87/4 and L88/5. These cell lines, previously established in our laboratory, are highly radiotolerant without cell detachment and support long-term cultures of CD(34+)-enriched human cord blood cells. RT-PCR analysis of 22 different cytokines or cytokine receptor mRNAs showed an almost identical expression pattern in the two stromal cell lines compared to primary human Dexter-type stroma. Since stromal feeder lines employed in long-term cultures usually are irradiated and grown in media containing corticosteroids, we analyzed the impact of irradiation and dexamethasone on cytokine production in the two cell lines by RT-PCR, Northern blot analysis, bioassays, and RIAs. By RT-PCR analysis, constitutive mRNA expression of c-kit, G-CSF, GM-CSF, IL-1 beta, IL-6, IL-7, IL-8, IL-11, Kit ligand (KL), LIF, M-CSF, MIP-1 alpha, TGF-beta, and TNF-alpha was demonstrated in both cell lines, with L87/4 a more potent cytokine producer than L88/5. Northern blot data showed an increase in mRNA levels for GM-CSF, IL-1 beta, and LIF by irradiation and IL-1 alpha treatment in both cell lines. IL-1 alpha-induced GM-CSF, IL-1 beta, IL-6, IL-11, and LIF mRNA levels were reduced by the addition of dexamethasone, whereas dexamethasone had no influence on the amounts of IL-1 alpha-induced G-CSF mRNA. L87/4 and, to a lower extent, L88/5 cells showed dexamethasone-dependent increases in KL mRNA, while KL mRNA levels were not stimulated by IL-1 alpha.

Identification of two new mutations in congenital erythropoietic porphyria.

Congenital erythropoietic porphyria (CEP) or Günther's disease is an inborn error of heme biosynthesis transmitted as an autosomal recessive trait and characterized by a profound deficiency of uroporphyrinogen III synthase (UROIIIS) activity. Six missense mutations in the UROIIIS gene, a deletion and an insertion have already been described in CEP. This work brings further evidence for the heterogeneity in the genetic defect found in CEP. Two new mutations are described, a point mutation (V99A) and a frame-shift mutation (633insA) in the same patient who had a mild to moderate form of Günther's disease. The mutation (V99A) had a detectable residual activity when expressed in Escherichia coli while the insertion (633insA), which introduced a premature stop, had no activity. In the patients studied in our laboratory, the mutation C73R, associated with a severe phenotype, remains the most frequently seen.

The value of urine testing for verifying adherence to anti-tuberculosis chemotherapy in children and adults in Uganda.

SETTING: Mulago Hospital, Kampala, Uganda. OBJECTIVE: To evaluate the usefulness of urine dipsticks for monitoring adherence to anti-tuberculosis chemotherapy. DESIGN: In-house urine dipsticks for detection of isoniazid (INH) metabolites were compared to commercial test strips. The value of n-butanol to detect rifampicin was compared to coloration of the urine. Non-adherence was assessed through a questionnaire and reviews of the Mulago Hospital TB register. RESULTS: Urine was obtained from 236 patients (127 adults and 109 children) on daily chemotherapy. Using commercial test strips as standard, the sensitivity of in-house urine dipsticks was 99.5% and specificity was 96.4%. The sensitivity and the specificity of n-butanol and of coloration of urine to detect rifampicin were low (64.0% and 54.9%, and 85.5% and 64.8%, respectively). Fifty patients (21.2%) admitted non-adherence to treatment during the previous month. An additional 15 (6.8%) were detected through urine testing. Of 911 patients in the TB register of Mulago Hospital who had started treatment in the first 3 months of 2000, 39.7% did not complete their treatment. Two-thirds of these had discontinued treatment in the first 2 months. CONCLUSION: In-house INH test strips are as effective as commercially available strips for detecting isoniazid in the urine. They are a simple tool for monitoring adherence. Adherence to anti-tuberculosis chemotherapy as determined by the use of isoniazid test strips and review of the TB register showed poor compliance. Tests for rifampicin are less sensitive and specific.

Validation of a pencil beam model-based treatment planning system for fast neutron therapy.

Treatment planning systems (TPSs) are used to compute dose delivered to the patient. In the case of fast neutron therapy, TPSs are mostly not of general purpose but are dedicated to one facility. This is due to the few fast neutron facilities worldwide and due to the high variation in the neutron energy distributions. Efforts have been undertaken to develop a new TPS that could be applied to all the existing fast neutron facilities. The University Hospital of Essen operates a d (14 MeV) + Be fast neutron beam and the TPS used is based on an empirical model. In a previous study, the empirical model has been evolved to a pencil beam model of 35 monoenergetic neutron beams. Monte Carlo techniques have been utilized to compute distributions of the energy deposition due to primary and scattered neutrons in a simple geometry water phantom. The experimental validation of the method is now presented. Depth dose curves in water of monoenergetic neutrons have been derived from the distributions of energy deposition. The resultant depth dose curves have been utilized in order to determine the depth dose curves of the fast neutron beam of the Essen facility for the 14 radiation field sizes available in this facility. This determination requires the initial neutron spectrum. As this spectrum could not be measured at the Essen facility, the initial neutron spectrum of the Physikalisch Technische Bundesanstalt, Braunschweig, Germany, which operates the same cyclotron, was used. The calculated depth dose curves were compared to experimental depth dose curves that have been obtained in water at the University Hospital of Essen. The comparison between calculated and experimental depth dose curves showed significant deviations in the case of large radiation fields and of depth less than 5 cm. In the case of radiation field areas less than 150 cm2 and depth more than 5 cm (usual clinical situation), the measured and calculated values are in a good agreement. In the case of clinical situation, the dependence on the radiation field size is relatively well taken into account by the model presented here.

Empirical description and Monte Carlo simulation of fast neutron pencil beams as basis of a treatment planning system.

The fast neutron beam, used for fast neutron therapy in Essen, is produced by the nuclear reaction of a 14 MeV cyclotron-based deuteron beam on a thick beryllium target. The resulting neutron beam has a continuous energy spectrum with a mean and a maximum energy equal to 5.5 and 18 MeV, respectively. The dose delivered to the patient is computed by a treatment planning system (TPS) based on an empirical model, in which the dose components (neutron and photon) are described by analytical functions. In order to improve the dose calculation, and thus to use the fast neutron beam for other applications (e.g., Boron Neutron Capture Enhancement of Fast Neutron Therapy), in this work we aim to develop a new TPS. For this purpose, a model based on pencil beams of mono-energetic neutrons has been created. The neutron energy ranged from 0.25 MeV up to 17.25 MeV by steps of 0.5 MeV in order to cover the energy range of the Essen facility. The Monte Carlo method was then used to simulate the transport of neutrons within such pencil beams in a homogeneous water phantom. By using Monte Carlo techniques, it is possible to distinguish the energy deposition due to a primary collision in water to that due to scattered neutrons. The energy deposition due to pencil beams of 2.224 MeV photons, coming from hydrogen neutron capture reaction in the phantom or in the collimator, was also determined. In order to complete this work, air filled cylinders have been introduced in the water phantom. It is shown that the resulting depth dose curves for primary neutrons can be easily derived using the homogeneous phantom, and that the description of the effect on scattered neutron dose distribution is more complex. In this work we demonstrate the relevance of Monte Carlo simulations of mono-energetic neutron pencil beams for purposes of neutron treatment planning. Some additional work is still required to describe a clinical situation (continuous energy neutron spectrum) as well as to experimentally validate the method described here.

Infrared and visible thermoluminescence signals of Tm-doped CaF2 measured by a semiconductor photodiode.

A silicon semiconductor photodiode was used to measure the TL-signal of TLD-300 (CaF2:Tm) detectors irradiated with 60Co gamma rays and 226Ra alpha particles. The applied dose values varied from 0.12 to 14.3 Gy for gamma rays and from about 50 to 300 Gy for alpha particles. Because of the infrared sensitivity of the photodiode the infrared emission of the planchet and the TLD-detector produced a high output signal above about 200 degrees C. In addition to this background signal an infrared emission from the TLD-300 detectors could be detected. This infrared TL-signal exhibited the same dose dependences as the visible signal, but the amplitude was higher than that of the visible TL-signal. For the applied photodiode the ratio of the infrared TL-signal to the visible TL-signal was about 24 for the 100 degrees C peak, about 15 for the 150 degrees C peak and 6 for the 240 degrees C peak.

Maximizing the functional status of geriatric patients in an acute community hospital setting.

Patients (n = 103) admitted to an inpatient geriatric care unit focusing on restoration of functional status were compared to similar patients (n = 75) admitted to a control-unit. Study unit patients showed significantly greater improvement in basic functional capabilities from admission to discharge than did control-unit patients. A mixed picture evolved when length of stay and total charges of study and control-unit patient were compared by diagnostic-related groups.

Alcoholic beverages in acute porphyria.

Alcohol consumption habits and the clinical consequences of intake of alcoholic beverages were examined in 254 individuals with a diagnosis of acute intermittent porphyria or variegate porphyria, using a questionnaire. The study failed to demonstrate a connection between the amount of ethanol consumed, or the frequency of ingestion, and the development of symptoms of acute porphyria, other than in extreme consumption patterns. It was concluded that agents in alcoholic beverages other than ethanol play important roles in precipitating the porphyric symptoms. A majority of the individuals were able to identify alcoholic beverages that were less well tolerated and those that were better tolerated. The results suggest that polyphenolic compounds and 3 to 5 carbon chain hydrophobic alcohols may be responsible for the induction of clinical symptoms in acute porphyria by some alcoholic beverages. On the basis of these findings advice is proposed on alcohol counseling in inducible porphyria.

Nebulized voriconazole in infections with Scedosporium apiospermum--case report and review of the literature.

Scedosporium infections are rare complications in immunocompromised patients or patients with chronic pulmonary disease. While Scedosporium prolificans is resistant to most antimycotics, Scedosporium apiospermum is usually sensitive to voriconazole and posaconazole. Pharmacokinetics and efficacy of nebulized voriconazole have been described in a murine model previously. We report for the first time the safe and effective use of nebulized voriconazole for the treatment of severe pulmonary infection with Scedosporium apiospermum in an adolescent with cystic fibrosis.

Acute intermittent porphyria presenting as progressive muscular atrophy in a young black man.

Acute intermittent porphyria, the most common porphyria affecting the nervous system, typically presents with neurovisceral crises followed by a motor neuropathy. We describe a 23-year-old black South African man presenting with a progressive stuttering, lower motor neuron syndrome developing over months. He had not experienced pain or neuropsychiatric symptoms. One year after symptom onset he was bed-bound with a flaccid quadriparesis. There was marked amyotrophy, but without fasciculations. Sensation was intact apart from a hypo-aesthetic patch over the thigh. Electrophysiological investigations showed an active motor axonopathy. Urinary porphyrins, delta-aminolaevulinic acid and porphobilinogen were elevated. Mutation analysis revealed the c445C>T (R149X) mutation in the porphobilinogen deaminase gene. The patient responded dramatically to haem arginate and could walk with assistance 2 weeks later. We identified the first molecularly confirmed acute intermittent porphyria in a black South African. The clinical presentation mimicked a progressive lower motor neuron syndrome.