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Kidney iron deposition measured by R2* (magnetic resonance imaging) MRI is posited to result from tubular reabsorption of filtered haemoglobin due to intravascular haemolysis. In chronically transfused sickle cell disease (SCD), R2* is elevated and positively correlated with lactate dehydrogenase (LDH). To account for contributions to renal iron from systemic iron overload, we evaluated kidney R2*, urinary iron and haemolysis markers in 62 non-transfused SCD patients. On multivariate analysis, kidney R2* was associated with urinary iron and LDH (R2 = 0·55, P

Alpha thalassemia is a hemoglobinopathy due to decreased production of the α-globin protein from loss of up to four α-globin genes, with one or two missing in the trait phenotype. Individuals with sickle cell disease who co-inherit the loss of one or two α-globin genes have been known to have reduced risk of morbid outcomes, but the underlying mechanism is unknown. While α-globin gene deletions affect sickle red cell deformability, the α-globin genes and protein are also present in the endothelial wall of human arterioles and participate in nitric oxide scavenging during vasoconstriction. Decreased production of α-globin due to α-thalassemia trait may thereby limit nitric oxide scavenging and promote vasodilation. To evaluate this potential mechanism, we performed flow-mediated dilation and microvascular post-occlusive reactive hyperemia in 27 human subjects (15 missing one or two α-globin genes and 12 healthy controls). Flow-mediated dilation was significantly higher in subjects with α-trait after controlling for age (P = .0357), but microvascular perfusion was not different between groups. As none of the subjects had anemia or hemolysis, the improvement in vascular function could be attributed to the difference in α-globin gene status. This may explain the beneficial effect of α-globin gene loss in sickle cell disease and suggests that α-globin gene status may play a role in other vascular diseases.

Introduction Absence of alpha globin genes has long been known to influence the physiology of sickle cell disease (SCD). Individuals with SCD who are missing one or two alpha globin genes have decreased rates of cerebral vasculopathy, stroke, acute chest syndrome, and leg ulcers (Bernaudin, Blood 2008; Flanagan, Blood 2011; Nolan, Br J Haematol 2006). Although there is laboratory evidence of decreased hemolytic rate in these patients (Higgs, N Engl J Med 1982), the mechanism for their improved clinical outcomes has not been identified. Recently, the alpha globin protein has been shown to be present in the endothelial wall of human arterioles, where it modulates nitric oxide (NO) scavenging during vasoconstriction (Straub, Nature 2012). In mice, pharmacological inhibition of alpha globin leads to increased endothelial NO activity, independently of NO production, and results in increased blood perfusion, reduced systemic hypertension, and increased pulmonary artery vasodilation (Keller, Hypertension 2016; Alvarez, Am J Respir Cell Mol Biol 2017). The relationship between absence of alpha globin and arterial vasodilation, and the role of alpha globin in NO-mediated vascular signaling are potential mechanisms that could explain the beneficial effect of missing alpha globin genes in SCD. Using alpha thalassemia as a naturally occurring human model of alpha globin gene knockout, we hypothesized that loss of alpha globin genes leads to improvement in microvascular blood flow in thalassemia trait subjects without hemolysis. Methods Alpha thalassemia trait subjects missing one or two alpha globin genes, and healthy controls were recruited to the study, which was approved by the Children's Hospital Los Angeles Institutional Review Board. Blood samples were obtained from all subjects to test for hemoglobin, mean corpuscular volume (MCV), reticulocyte count, plasma hemoglobin, lactate dehydrogenase, and alpha globin genotype. We assessed flow-mediated dilation (FMD) of the brachial artery following distal forearm occlusion (Detterich, Blood 2015) simultaneously with laser Doppler flowmetry (LDF) and photoplethysmography (PPG) in the fingertip. We also measured the increase in microvascular perfusion with a thermal stimulus. The maximal change in vascular perfusion after provocation indicates vasodilatory capacity. Statistical analysis was performed in JMP® version 14 (SAS Institute Inc., USA). Results Twenty-seven subjects were enrolled, including 12 controls (4 alpha globin genes), 10 patients with 3 alpha globin genes and 5 with 2. The mean MCV was lower in subjects missing alpha globin genes than in controls (p=0.0099). Importantly, hemoglobin levels and markers of hemolysis were normal in both groups. There was no detectable difference in FMD between individuals missing one and two alpha globin genes; thus, these groups were combined and labeled as alpha trait for further analyses. FMD was significantly higher in alpha trait subjects after adjusting for age (Figure 1, p=0.0357). Missing alpha globin genes had no effect on microvascular flow by LDF or PPG (data not shown). Discussion FMD is an established and specific predictor of NO bioavailability (Thijssen, Am J Physiol Heart Circ Physiol 2011), and, in addition to shear-mediated NO circulation in conduit vessels, it reflects the sum of flow in multiple arteriolar networks downstream of the conduit artery. Using this method, a difference in endothelial function between control and alpha thalassemia trait was easily detected (Figure 1). Because endothelial alpha globin is present in arterioles rather than conduit vessels (Butcher, Free Radic Biol Med 2014), we measured microvascular flow in a 1-mm3 volume in the skin using a laser Doppler sensor, and in the fingertip by PPG, but were unable to detect an effect of alpha trait. As none of the subjects had anemia or evidence of hemolysis, the significantly increased FMD associated with loss of alpha globin genes is most likely due to increased NO as a result of decreased scavenging by alpha globin. The finding reported here that lower alpha globin gene number is associated with increased NO-related perfusion in humans may explain the beneficial effect of alpha thalassemia trait in SCD and suggests that the presence of alpha thalassemia trait may also play a role in other types of vascular disease. Disclosures Wood: BiomedInformatics: Consultancy; Imago Biosciences: Consultancy; BluebirdBio: Consultancy; Celgene: Consultancy; WorldcareClinical: Consultancy; Philips Medical Systems: Research Funding. Coates:apo pharma (Chiesi Pharma): Consultancy, Honoraria; Sangamo: Honoraria, Membership on an entity's Board of Directors or advisory committees; Agios pharma: Consultancy, Honoraria; Vifor Pharma: Consultancy, Honoraria; Celgene, BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Bluebird Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Konzo is an irreversible paralysis of the legs that occurs mainly in children and young women associated with large cyanide intake from bitter cassava coupled with malnutrition. In East Africa outbreaks occur during drought, when cassava plants produce much more cyanogens than normal. A wetting method that removes cyanogens from cassava flour was taught to the women of three konzo villages in Mozambique, to prevent sporadic konzo and konzo outbreaks in the next drought. The intervention was in three villages with 72 konzo cases and mean konzo prevalence of 1.2%. The percentage of children with high (>350 μmol/L) urinary thiocyanate content and at risk of contracting konzo in Cava, Acordos de Lusaka, and Mujocojo reduced from 52, 10, and 6 at baseline to 17, 0, and 4 at conclusion of the intervention. Cassava flour showed large reductions in total cyanide over the intervention. The percentage of households using the wetting method was 30–40% in Acordos de Lusaka and Mujocojo and less in Cava. If the wetting method is used extensively by households during drought it should prevent konzo outbreaks and chronic cyanide intoxication. We recommend that the wetting method be taught in all konzo areas in East Africa.

Highlights • In 6 villages we measured konzo prevalence, urinary thiocyanate and FC scores. • % konzo prevalence (%K), % high urine thiocyanate (%T), % malnutrition (%M) relate. • The results fitted an equation %K = 0.06%T + 0.035%M. • The wetting method was used by women over a 9-month intervention to prevent konzo. • The methodology has now been used with nearly 10,000 people in 13 villages., Six villages in Boko Health Zone, Bandundu Province, DRC, were studied with 4588 people, 144 konzo cases and konzo prevalences of 2.0–5.2%. Konzo incidence is increasing rapidly in this area. Food consumption scores were obtained from the households with konzo and the mean % malnutrition calculated for each village. Urine samples were obtained from 50 school children from each village and % high urinary thiocyanate content (>350 μmol/L) determined. The experimental data relating % konzo prevalence (%K) to % children with high urinary thiocyanate content (%T) and % malnutrition (%M) for the six villages were fitted to an equation %K = 0.06%T + 0.035%M. This confirms that konzo is due to a combination of high cyanide intake and malnutrition. The village women used the wetting method to remove cyanogens from cassava flour. During the 9-month intervention there were no new cases of konzo; cyanide in flour had reduced to WHO safe levels and mean urinary thiocyanate levels were greatly reduced. To prevent konzo at least 60–70% of women should use the wetting method regularly. The wetting method is now accepted by the World Bank, FAO and WHO as a sensitive intervention. Four successful konzo interventions have involved nearly 10,000 people in 13 villages, the cost is now $16 per person and the methodology is well established.

To evaluate ferritin and zinc protoporphyrin-to-heme (ZnPP/H) ratios as biomarkers of iron status in neonates, determine how specific clinical events affected these measures, and assess how iron status changed during hospitalization.We performed a retrospective study of all infants with paired ferritin and ZnPP/H measurements between October 2014 and May 2016. Concordance of these measurements, effects of sepsis, red blood cell transfusion, erythropoietin treatment, and iron supplementation were assessed. Iron status was measured over time.A total of 228 patients (mean birth weight 1.3 kg, median gestational age 29 weeks) were evaluated. Mean log ZnPP/H values in infants with and without sepsis were not significantly different (4.98 µmol/mol vs 4.97 µmol/mol, adjusted P = .103), whereas log-transformed ferritin values increased significantly during infection (5.23 ng/mL vs 4.04 ng/mL, adjusted P .001). Ferritin also increased more significantly than ZnPP/H following red blood cell transfusion (ferritin: mean 5.03 ng/mL vs 4.0 ng/mL, P .001; ZnPP/H: mean 4.85 µmol/mol vs 4.98 µmol/mol, P .001). The mean iron supplementations at 30, 60, and 90 days were 5.4, 6.9, and 7.4 mg/kg/day, respectively. Ferritin values decreased with advancing postnatal age (adjusted P .001), with 66% of ferritin values less than 76 ng/mL. Treatment with erythropoietin increased ZnPP/H, but not ferritin levels.Ferritin is more significantly affected by inflammatory events such as sepsis and transfusion than ZnPP/H, thus, ZnPP/H may be a more reliable marker of iron status in this population. Infants showed worsening iron sufficiency over time despite supplementation above American Academy of Pediatrics guidelines.

There were 68 konzo cases in three villages in Boko Health Zone, Bandundu Province, Democratic Republic of Congo (DRC), where yearly incidence had increased greatly since 2009. The nine months long intervention to prevent konzo started in the wet season. Village women were taught the wetting method, after which there were no new konzo cases and urinary thiocyanate levels were low. Using data from four different interventions in March 2010, July 2011, September 2013 and the present intervention in October-November 2012, a correlation was found between the monthly cyanide intake (measured by percentage of children with high urinary thiocyanate level) and the monthly konzo incidence. This dose response relationship between cyanide intake and konzo incidence, together with the prevention of konzo in many villages using the wetting method to reduce cyanogen intake, shows that konzo is very likely to be due to high cyanide/low sulfur amino acid intake in a diet of bitter cassava.

Introduction Kidney iron deposition has been described in hemolytic disorders including mechanical valves, paroxysmal nocturnal hematuria, and sickle cell disease (Roberts & Morrow, Circulation 1966; Leonardi & Ruol, Blood 1960). Circulating plasma hemoglobin is filtered at the glomerulus and reabsorbed via the megalin cubulin system in the proximal and distal tubules (Gburek et al, J Am Soc Nephrol 2002). On MRI, this manifests as signal loss on gradient and spin echo sequences in the cortex of the kidney with complete sparing of the medulla (Jeong et al, Radiographics 2002). The signal darkening is quantified by the parameter R2*, which has been shown to be directly proportional to tissue iron in the liver and heart. Kidney R2* has previously been demonstrated to rise proportionally to lactate dehydrogenase (LDH) in chronically transfused sickle cell disease (SCD) patients (Wood et al, Br J Haematol 2016; Schein et al, J Magn Reson Imaging 2008), but LDH is not a specific marker of hemolysis, and chronically transfused patients could potentially deposit iron in the kidney through other mechanisms. Therefore, we characterized the relationship between kidney R2*, urinary iron and markers of hemolysis in non-transfused SCD patients. Methods Sixty-five non-transfused SCD patients were recruited to the study, which was approved by the Institutional Review Board of Children's Hospital Los Angeles. Following medical history and physical exam, subjects completed blood and urine testing, and then abdominal MRI for assessment of somatic iron stores. R2* measurements were collected using multiple gradient echo pulse sequences on 1.5 Tesla magnets. Statistical analysis was performed using JMP® Pro, Version 14.0.0 (SAS Institute Inc., Cary, NC, 2018). Results Subjects were generally adults with a mean age of 32 years. Nearly three quarters of subjects had homozygous sickle cell disease, while a quarter had SC disease or S-Beta thalassemia, and one subject had sickle cell trait. Most subjects were anemic, and all subjects had elevated markers of hemolysis. Fifty-four percent of subjects had an elevated kidney R2* level (≥34 Hz). On univariate analysis, kidney R2* was associated with urinary iron (R2=0.52, p Discussion Our study supports previous findings that kidney R2* is associated with intravascular hemolysis, as measured by plasma hemoglobin and LDH, and inversely by hemoglobin (Kato et al, Blood 2006). The stronger association with urinary iron reinforces the concept that kidney R2* reflects filtered iron, which is insufficiently reabsorbed due to proximal and distal tubular injury in iron overload (van Raaij et al, Am J Physiol Renal Physiol 2019). Urinary iron is also elevated in diabetic nephropathy (Van et al, J Am Soc Nephrol 2017) and nephrotic syndrome (Niel et al, Blood 2011). These data raise important questions regarding the possible role of iron in sickle related renal disease. Disclosures Coates: apo pharma: Consultancy, Honoraria, Speakers Bureau; vifor: Consultancy, Honoraria; agios pharma: Consultancy, Honoraria; celgene: Consultancy, Honoraria, Other: steering committee of clinical study. Wood:National Institutes of Health: Research Funding; Philips Healthcare: Research Funding; BluebirdBio: Consultancy; Celgene: Consultancy; Apopharma: Consultancy; WorldcareClinical: Consultancy; BiomedInformatics: Consultancy; Imago Biosciences: Consultancy.

Current methods for processing cassava leaves to remove cyanogens involve pounding followed by boiling in water or boiling intact leaves for 30 min or longer. Boiling in water rapidly removes cyanogens but also breaks down vitamins, proteins and S-containing amino acids, which are necessary to detoxify ingested cyanide. Two methods have been developed to remove cyanogens whilst conserving these key nutrients present in cassava leaves. The first method involves pounding leaves in a pestle and mortar for a minimum of 10 min until the leaves are well macerated, followed by washing the pounded leaves twice in twice their weight of water at ambient temperature, which reduces the total cyanide remaining to 8%. Two further washes reduce the total cyanide to 3%. The second method is to immerse cassava leaves in ten times their weight of water at 50 ± 3 °C for 2 h followed by one change of water and further immersion for 2 h at 50 °C which reduces the total cyanide remaining to 7%.

The lactic acid content of gari, was determined by pH titration to be about 10 g lactic acid/kg gari. As the size of the gari particles increased from 400 to >1000 μm their total cyanide content increased from 5 to 21 ppm. The acetone cyanohydrin content of gari samples exposed to ambient laboratory conditions of temperature and relative humidity gradually decreased by 58% in 38 weeks whereas linamarin in cassava flour is 100% stable for 6 months. Cyanogens could not be removed from wet gari samples at 30 or 50 °C and were only slowly removed by repeated heating at 100 °C and rewetting. By mixing equal weights of gari (pH 4.1) and low cyanide cassava flour (pH 6.5), wetting and heating at 50 °C for 5 h, the cyanide content was reduced by about one half. Wetting a gari/flour (1:1) sample with 1.5 times its weight of water and standing in a 1 cm thick layer in the sun for 4 h reduced the cyanide content by about one half. This treated mixture may be cooked to prepare stiff porridge with lowered cyanide content, and may help reduce tropical ataxic neuropathy in West Africa.

In 2005 a simple wetting method was developed that reduced total cyanide content of cassava flour 3–6-fold. The method involved spreading wet flour in a thin layer and standing in the shade for five hours to allow evolution of HCN gas. We found that breakdown of linamarin catalysed by linamarase to acetone cyanohydrin, followed by its spontaneous decomposition to HCN and acetone was greatly increased by standing the wet flour in the sun. Treatment for two hours in the sun gave the same amount of total cyanide remaining as five hours in the shade. This rapid treatment in the sun may be more acceptable to rural women in Democratic Republic of Congo, than five hours in the shade. The two methods are offered as alternatives for use in rural Africa. With adequate linamarase present the residual cyanogen remaining after the wetting treatment was acetone cyanohydrin.

The constructal solution for cooling of electronics requires solution of a fundamental heat conduction problem in a composite slab composed of a heat generating slab and a thin strip of high conductivity material that is responsible for discharging the generated heat to a heat sink located at one end of the strip. The fundamental 2D heat conduction problem is solved analytically by applying an integral transform method. The analytical solution is then employed in a constructal solution, following Bejan, for cooling of electronics. The temperature and heat flux distributions of the elemental heat generating slabs are assumed to be the same as those of the analytical solution in all the elemental volumes and the high conductivity strips distributed in the different constructs. Although the analytical solution of the fundamental 2D heat conduction problem improves the accuracy of the distributions in the elemental slabs, the results following Bejan’s strategy do not affirm the accuracy of Bejan’s constructal solution itself as applied to this problem of cooling of electronics. Several different strategies are possible for developing a constructal solution to this problem as is indicated.

There appear to be some fundamental disagreements between those scientists and engineers who adhere to the principles of macroscopic classical thermodynamics and those who adhere to the principles of finite time thermodynamics. In many instances, the disagreements can be traced to differing assumptions concerning fundamental principles, definitions, etc., as well as differing interpretations of fundamental principles, definitions, etc. This paper is an attempt to clarify the issues by consideration, in somewhat laborious detail, of the basic definitions and their interpretations, considering the fundamental principles of classical thermodynamics and nonequilibrium thermodynamics. It appears to the author that nonequilibrium thermodynamics might offer a reconciliation of the disagreements and provide an approach acceptable to both sides. The work is purposely limited to considerations of importance in thermal cycles, mostly isothermal heat addition and rejection, and no attempt is made to treat even this broad field comprehensively. It is hoped that such discussions will lead to resolution of the disagreements, at least in part. Given the tendency of thermodynamicists to argue, in all probability, the discussions will lead to additional disagreements.

Background Konzo is an irreversible paralysis of the legs that occurs mainly among children and young women in remote villages in tropical Africa and is associated with a monotonous diet of bitter cassava. Konzo was discovered in 1938 by Dr. G. Trolli in the Democratic Republic of Congo (DRC). It also occurs in Mozambique, Tanzania, Cameroon, Central African Republic, and Angola. It was first controlled in Kay Kalenge village, DRC, in 2011 with the use of a wetting method to remove cyanogens from cassava flour. Fourteen months later, another visit was made to Kay Kalenge. Objective To determine whether Kay Kalenge women were still using the wetting method, whether there were new cases of konzo, and whether the wetting method had spread to other villages. Methods Meetings were held with chiefs, leaders, and heads of mothers' groups, women from 30 households were interviewed, and three nearby villages were visited. Total cyanide and thiocyanate were analyzed in cassava flour and urine samples, respectively. Results The women in Kay Kalenge village still used the wetting method. There were no new cases of konzo. The mean cyanide content of the flour samples was 9 ppm, and no child had a mean urinary thiocyanate content greater than 350 μmol/L. The use of the wetting method had spread naturally to three adjacent villages. Conclusions The wetting method has been readily accepted by rural women as a simple and useful method to control konzo by removing cyanide from cassava flour, and its use has spread to nearby villages. The wetting method should be promoted by health authorities to control konzo and reduce cyanide poisoning from high-cyanide cassava flour.

A mild method was developed to remove cyanogens from cassava leaves that involved three consecutive steps (1) pounding, (2) standing for 2 h in the sun or 5 h in the shade in the tropics and (3) washing three times in water. Four cassava cultivars were used and the mean residual total cyanide content after steps 1, 2 and 3 was 28%, 12% and 1%, respectively. The pounded cassava leaves retained their bright green colour and texture. The traditional method for removing cyanogens from pounded cassava leaves is by boiling in water which removed all cyanogens in 10 min. However this method caused the pounded leaves to become dull green in colour and would cause considerable losses of vitamins, protein and methionine, which are already in short supply in the diet of poor village people in tropical Africa.

Cassava contains cyanogenic glucosides which are hydrolysed by an enzyme linamarase to produce cyanohydrins which breakdown to toxic cyanide. Cyanide ingestion from bitter cassava can cause cyanide poisoning sometimes leading to death and also konzo, an irreversible paralysis of the legs which occurs mainly in children and young women. In 2005 we developed a simple wetting method that reduces the total cyanide content of cassava flour 3–6-fold. It involves wetting the flour, spreading it in a thin layer in the shade for 5 h and using it the same day to make traditional thick porridge (ugali). The method was readily accepted by rural women and requires no additional equipment or water. Laminated, illustrated posters describing the method are available for free in ten languages, see http://online.anu.edu.au/BoZo/CCDN/ . An equally effective treatment method is to expose wet flour in a thin layer in the sun for 2 h. Projects for rehabilitation and prevention of konzo occurred in Mozambique in 2007 and in 2008–2009 in Tanzania, funded by AusAID. The Ministry of Health in Mozambique is now using our posters in Macua. In Uvira DRC, the wetting method has been taught in many villages and over 1200 posters distributed.

Room‐temperature measurements of linear and nonlinear photoconductivity in CaF2 containing trace amounts of yttrium, lanthanum, and several rare earths are reported and discussed. Linear spectral photoconductivity scans taken over the 1.55‐ to 6.20‐eV range of photon energies produced significant photocurrents above 3 eV. The results are explained in terms of a combination of 4f‐5d absorption in Ce+3 and Pr+3 and photoionization of interstitial F− in both nearest‐neighbor charge‐compensating defects and anion‐Frenkel defects. Peak photocurrents induced by focused 950‐ns‐wide pulses from a 496.5‐nm wavelength dye laser increased nonlinearly with increasing laser pulse energy. These results are interpreted as a transition from two‐photon conductivity to electron avalanche and the asymptotic approach to the material’s laser damage threshold at approximately 27 GW/cm2.

The effects of prostaglandin F2α (PGF2α), serotonin (5-HT) and norepinephrine (NE) on cerebrovascular tone, external carotid pressure, and femoral arterial pressure were compared in the monkey. Cerebrovascular tone was assessed by means of a perfusion technique in which a constant flow of blood was delivered into one internal carotid artery and the perfusion pressure recorded. The drugs were administered into the perfusion system. Prostaglandin F2α (10 μg/kg/min) selectively increased cerebrovascular tone. In most animals it caused the perfusion pressure to rise sooner and far higher than the other pressures. In some, only the perfusion pressure rose. Serotonin (5 μg/kg/min) also selectively increased cerebrovascular tone. However, NE (2 μg/kg/min) failed to have a selective effect, all arterial pressures being similarly elevated. Apparently the receptor responsible for the action of PGF2α on cerebral vessels is different from those for 5-HT and NE since the latter drugs were blocked by methysergide and phenoxybenzamine without preventing the characteristic effect of PGF2α. The possibility that PGF2α may play a role in cerebrovascular autoregulation or in the pathogenesis of vasospasm was proposed.

✓ Alterations in cerebrovascular tone caused by the intracarotid administration of prostaglandin E1, A1, and F2a were evaluated by means of a standard perfusion technique in dogs and monkeys. Only PGF2a evoked a selective increase in cerebrovascular tone. This effect was observed in both species and resembled the action of serotonin. On the other hand, prostaglandin E1 selectively reduced cerebrovascular tone in dogs, but had no such specific action in the monkey. Prostaglandin A1 lacked a specific influence on the cerebral circulation of either species. Since different prostaglandins produced specific and diametrically opposite effects on cerebral circulation, these substances may be useful in experimental studies of vasospasm, and may normally influence cerebrovascular tone.