The distribution of cadmium in soil and cacao beans in Peru.

Peru is the eighth largest producer of cacao beans globally, but high cadmium contents are constraining access to international markets which have set upper thresholds for permitted concentrations in chocolate and derivatives. Preliminary data have suggested that high cadmium concentrations in cacao beans are restricted to specific regions in the country, but to date no reliable maps exist of expected cadmium concentrations in soils and cacao beans. Drawing on >2000 representative samples of cacao beans and soils we developed multiple national and regional random forest models to develop predictive maps of cadmium in soil and cacao beans across the area suitable for cacao cultivation. Our model projections show that elevated concentrations of cadmium in cacao soils and beans are largely restricted to the northern parts of the country in the departments of Tumbes, Piura, Amazonas and Loreto, as well as some very localized pockets in the central departments of Huánuco and San Martin. Unsurprisingly, soil cadmium was the by far most important predictor of bean cadmium. Aside from the south-eastern to north-western spatial trend of increasing cadmium values in soils and beans, the most important predictors of both variables in nation-wide models were geology, rainfall seasonality, soil pH and rainfall. At regional level, alluvial deposits and mining operations were also associated with higher cadmium levels in cacao beans. Based on our predictive map of cadmium in cacao beans we estimate that while at a national level <20 % of cacao farming households might be impacted by the cadmium regulations, in the most affected department of Piura this could be as high as 89 %.

Randomized Trial of Dexamethasone Versus Prednisone for Children with Acute Asthma Exacerbations.

OBJECTIVE: To determine whether 2 doses of dexamethasone is as effective as 5 days of prednisolone/prednisone therapy in improving symptoms and quality of life of children with asthma exacerbations admitted to the emergency department (ED). STUDY DESIGN: We conducted a randomized, noninferiority trial including patients aged 1-14 years who presented to the ED with acute asthma to compare the efficacy of 2 doses of dexamethasone (0.6 mg/kg/dose, experimental treatment) vs a 5-day course of prednisolone/prednisone (1.5 mg/kg/d, followed by 1 mg/kg/d on days 2-5, conventional treatment). Two follow-up telephone interviews were completed at 7 and 15 days. The primary outcome measures were the percentage of patients with asthma symptoms and quality of life at day 7. Secondary outcomes were unscheduled returns, admissions, adherence, and vomiting. RESULTS: During the study period, 710 children who met the inclusion criteria were invited to participate and 590 agreed. Primary outcome data were available in 557 patients. At day 7, experimental and conventional groups did not show differences related to persistence of symptoms (56.6%, 95% CI 50.6-62.6 vs 58.3%, 95% CI 52.3-64.2, respectively), quality of life score (80.0 vs 77.7, not significant [ns]), admission rate (23.9% vs 21.7%, ns), unscheduled ED return visits (4.6% vs 3.3%, ns), and vomiting (2.1% vs 4.4%, ns). Adherence was greater in the dexamethasone group (99.3% vs 96.0%, P < .05). CONCLUSION: Two doses of dexamethasone may be an effective alternative to a 5-day course of prednisone/prednisolone for asthma exacerbations, as measured by persistence of symptoms and quality of life at day 7. CLINICAL TRIAL REGISTRATION: clinicaltrialsregister.eu: 2013-003145-42.

Intermediate Charcot-Marie-Tooth disease: an electrophysiological reappraisal and systematic review.

Charcot-Marie-Tooth disease (CMT) is the most frequent form of inherited neuropathy with great variety of phenotypes, inheritance patterns, and causative genes. According to median motor nerve conduction velocity (MNCV), CMT is divided into demyelinating (CMT1) with MNCV below 38 m/s, axonal (CMT2) with MNCV above 38 m/s, and intermediate CMT with MNCV between 25 and 45 m/s. In each category, transmission may be autosomal dominant, autosomal recessive, or X-linked. The nosology of intermediate CMT is controversial because of concerns about electrophysiological delimitation. A systematic computer-based literature search was conducted on PubMed, using the following MeSH: (1) intermediate Charcot-Marie-Tooth; (2) X-linked intermediate Charcot-Marie-Tooth; and (3) X-linked Charcot-Marie-Tooth and electrophysiology. We retrieved 225 articles reporting X-linked CMT or intermediate CMT with electrophysiological information. After eligibility, 156 papers were used for this review. In assessing median MNCV, compound muscle action potential (CMAP) amplitudes were taken into account. In cases with attenuated CMAP and wherever possible, proximal median MNCV was used for accurate definition of conduction slowing in the intermediate range. In the vast majority of males with X-linked CMT associated with GJB1 mutation (CMTX1), median MNCV was intermediate. CMT associated with DRP2 mutation is another well-documented X-linked intermediate disorder. Autosomal dominant intermediate CMT (DI-CMT) encompasses 11 different types; six of them with assigned phenotype MIM number and the remaining five being unnumbered. Based on available electrophysiological information, we wonder if DI-CMTA should be reclassified within CMT2. Autosomal recessive intermediate CMT (RI-CMT) covers four numbered MIM phenotypes though, in accordance with reported electrophysiology, two of them (RI-CMTB and RI-CMTD) should probably be reclassified within AR-CMT2. We conclude that intermediate CMT is a complex inherited syndrome, whose characterization requires a specific electrophysiological protocol comprising evaluation of upper limb proximal nerve trunks when distal CMAP amplitudes are reduced, and that an updated version of MIM phenotype numbering is needed.