What is the margin of error of surgeons and radiological imaging in diagnosing acute appendicitis?

Background: Acute appendicitis is the most common emergency requiring surgical intervention in general surgery. Negative appendectomy is defined as the removal of a pathologically normal appendix. Aim: In this study, we aimed to show our negative appendectomy rate. Materials and Methods: This study was carried out among 2990 patients who were operated on for appendicitis between 2015-2020 at the Health Sciences University, Istanbul Kanuni Sultan Suleyman Training, and Research Hospital. Accrual and historical records of the patients were analyzed using NCSS (Number Cruncher Statistical System) 2007 Statistical Software (Utah, USA) package program. The results were evaluated at the significance level of P < 0.05. Results: The mean age of all patients was 33. Of the patients, 1011 were women and 1979 were men. 27 of the women patients were pregnant. We requested a blood test (WBC count) and an abdominal ultrasound for all our patients who came with the complaint of abdominal pain in the right lower quadrant. Negative appendectomy was performed with ultrasonography in 622 patients with pathological diagnoses of lymphoid hyperplasia and fibrous obliteration (20.8%). We had abdominal computerized tomography (CT) for 285 patients and abdominal magnetic resonance imaging (MRI) for 16 of 27 pregnant women (59.25%) due to unclear clinical picture. Diagnostic laparoscopy was performed in 36 of the patients who underwent CT and 4 of the patients who underwent MRI since the diagnosis could not be made. We performed unnecessary appendectomy in 21.2% of the patients. Conclusion: With the increasing clinical follow-up experience of surgeons and developing technology in radiology, our aim is to minimize the negative appendectomy rate as much as possible.

Biodegradation Studies of Polyhydroxybutyrate and Polyhydroxybutyrate-co-Polyhydroxyvalerate Films in Soil.

Due to increased environmental pressures, significant research has focused on finding suitable biodegradable plastics to replace ubiquitous petrochemical-derived polymers. Polyhydroxyalkanoates (PHAs) are a class of polymers that can be synthesized by microorganisms and are biodegradable, making them suitable candidates. The present study looks at the degradation properties of two PHA polymers: polyhydroxybutyrate (PHB) and polyhydroxybutyrate-co-polyhydroxyvalerate (PHBV; 8 wt.% valerate), in two different soil conditions: soil fully saturated with water (100% relative humidity, RH) and soil with 40% RH. The degradation was evaluated by observing the changes in appearance, chemical signatures, mechanical properties, and molecular weight of samples. Both PHB and PHBV were degraded completely after two weeks in 100% RH soil conditions and showed significant reductions in mechanical properties after just three days. The samples in 40% RH soil, however, showed minimal changes in mechanical properties, melting temperatures/crystallinity, and molecular weight over six weeks. By observing the degradation behavior for different soil conditions, these results can pave the way for identifying situations where the current use of plastics can be replaced with biodegradable alternatives.

A Mixed-Methods Examination of the Impact of the Partnerships to Improve Community Health Produce Prescription Initiative in Northeastern North Carolina.

OBJECTIVE: To conduct a mixed-methods examination of the impact of the Partnerships to Improve Community Health produce prescription initiative in northeastern North Carolina. DESIGN: Quantitative surveys were conducted among participants before and after the distribution of produce prescription vouchers. Univariate statistics were used to describe the participant population, and paired t tests were used to examine change in fruit and vegetable intake. Qualitative, in-depth telephone interviews were conducted among participants, health educators, and food retailers and coded for themes. SETTING: Eight health promotion programs, 2 food pantries, and 11 food retailers. PARTICIPANTS: In each health promotion program or food pantry, between 6 and 97 participants were enrolled. INTERVENTION: Produce prescription vouchers were distributed to participants and redeemed at local food retailers. MAIN OUTCOME MEASURE S: An increase in local fruit and vegetable purchasing and consumption. RESULTS: Of the produce prescription participants who completed the baseline survey (n = 93), 86% were female, 64% were African American, and 68% were food insecure. The voucher redemption rate was 18%. The majority of participants indicated that they visit farmers' markets more now than before the produce prescription initiative, that shopping at the farmers' market made it easy to include more fresh produce in their family's diet, and that they tried a new farmers' market because of the produce prescription initiative. All health educators and food retailers who participated felt that the initiative benefited their program or operation and were willing to partner with the program again. CONCLUSIONS: While redemption rates were lower than anticipated, the produce prescription initiative had positive impacts on participants' local fruit and vegetable purchasing and consumption. Because of COVID-19, the initiative was not implemented until late in the North Carolina produce season. Moving forward, the program will start earlier and work with local food retailers to connect with their communities to increase redemption rates.

Predicting the Mechanical Response of Polyhydroxyalkanoate Biopolymers Using Molecular Dynamics Simulations.

Polyhydroxyalkanoates (PHAs) have emerged as a promising class of biosynthesizable, biocompatible, and biodegradable polymers to replace petroleum-based plastics for addressing the global plastic pollution problem. Although PHAs offer a wide range of chemical diversity, the structure-property relationships in this class of polymers remain poorly established. In particular, the available experimental data on the mechanical properties is scarce. In this contribution, we have used molecular dynamics simulations employing a recently developed forcefield to predict chemical trends in mechanical properties of PHAs. Specifically, we make predictions for Young's modulus, and yield stress for a wide range of PHAs that exhibit varying lengths of backbone and side chains as well as different side chain functional groups. Deformation simulations were performed at six different strain rates and six different temperatures to elucidate their influence on the mechanical properties. Our results indicate that Young's modulus and yield stress decrease systematically with increase in the number of carbon atoms in the side chain as well as in the polymer backbone. In addition, we find that the mechanical properties were strongly correlated with the chemical nature of the functional group. The functional groups that enhance the interchain interactions lead to an enhancement in both the Young's modulus and yield stress. Finally, we applied the developed methodology to study composition-dependence of the mechanical properties for a selected set of binary and ternary copolymers. Overall, our work not only provides insights into rational design rules for tailoring mechanical properties in PHAs, but also opens up avenues for future high throughput atomistic simulation studies geared towards identifying functional PHA polymer candidates for targeted applications.

A meta-analysis of studies examining associations between resonance Raman spectroscopy-assessed skin carotenoids and plasma carotenoids among adults and children.

CONTEXT: No meta-analyses appeared to have been conducted to examine overall correlations between resonance Raman spectroscopy (RRS)-assessed skin carotenoids and plasma/serum carotenoids. OBJECTIVE: To review the available literature and quantify the association between RRS-assessed skin carotenoids and plasma/serum carotenoids via a meta-analysis of observational studies. DATA SOURCES: To identify relevant publications, we searched the PubMed, Embase, CINAHL, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, ProQuest, and Scopus databases in April 2020 for items combining 3 concepts: Raman spectroscopy, skin, and plasma or serum. DATA EXTRACTION: Criteria for inclusion were publication in a peer-reviewed journal between 1990 and 2020, available in English language, and results reported as a baseline Pearson correlation coefficient. In teams of 2, the researchers independently reviewed titles and abstracts of 2212 nonduplicate papers with initial screening yielding 62 papers for full-text review, of which 15 were deemed eligible for inclusion. DATA ANALYSIS: A random-effects model in R (version 4.0.0) "meta" package was used to analyze the correlation between RRS-assessed skin and plasma/serum carotenoids. A subgroup analysis was conducted for studies involving adults and children, respectively. CONCLUSIONS: The 15 studies included 1155 individuals: 963 adults and 192 children. One study included children and adults. The random-effects model yielded an overall correlation of 0.68 (95%CI, 0.61-0.74; I2 = 74%; P < 0.01). The results were similar when grouped by adults and children. Among 963 adults, the correlation in the random-effects model was 0.69 (95%CI, 0.61-0.75; I2 = 78%; P < 0.01). Among 192 children, the correlation in the random-effects model was 0.66 (95%CI, 0.52- 0.77; I2 = 55%; P = 0.06). Overall, there was a positive, statistically significant correlation between RRS-assessed skin carotenoids and plasma/serum carotenoids in a pooled meta-analysis of 15 studies. SYSTEMATIC REVIEW REGISTRATION: PROSPERO (record number 178835).

Characterization of Polyhydroxybutyrate-Based Composites Prepared by Injection Molding.

The waste generated by single-use plastics is often non-recyclable and non-biodegradable, inevitably ending up in our landfills, ecosystems, and food chain. Through the introduction of biodegradable polymers as substitutes for common plastics, we can decrease our impact on the planet. In this study, we evaluate the changes in mechanical and thermal properties of polyhydroxybutyrate-based composites with various additives: Microspheres, carbon fibers or polyethylene glycol (2000, 10,000, and 20,000 MW). The mixtures were injection molded using an in-house mold attached to a commercial extruder. The resulting samples were characterized using microscopy and a series of spectroscopic, thermal, and mechanical techniques. We have shown that the addition of carbon fibers and microspheres had minimal impact on thermal stability, whereas polyethylene glycol showed slight improvements at higher molecular weights. All of the composite samples showed a decrease in hardness and compressibility. The findings described in this study will improve our understanding of polyhydroxybutyrate-based composites prepared by injection molding, enabling advancements in integrating biodegradable plastics into everyday products.

Perceived barriers and facilitators to participating in the North Carolina Healthy Food Small Retailer Program: a mixed-methods examination considering investment effectiveness.

OBJECTIVE: The North Carolina Legislature appropriated funds in 2016-2019 for the Healthy Food Small Retailer Program (HFSRP), providing small retailers located in food deserts with equipment to stock nutrient-dense foods and beverages. The study aimed to: (1) examine factors facilitating and constraining implementation of, and participation in, the HFSRP from the perspective of storeowners and (2) measure and evaluate the impact and effectiveness of investment in the HFSRP. DESIGN: The current analysis uses both qualitative and quantitative assessments of storeowner perceptions and store outcomes, as well as two innovative measures of policy investment effectiveness. Qualitative semi-structured interviews and descriptive quantitative approaches, including monthly financial reports and activity forms, and end-of-programme evaluations were collected from participating HFSRP storeowners. SETTING: Eight corner stores in North Carolina that participated in the two cohorts (2016-2018; 2017-2019) of the HFSRP. PARTICIPANTS: Owners of corner stores participating in the HFSRP. RESULTS: All storeowners reported that the HFSRP benefitted their stores. In addition, the HFSRP had a positive impact on sales across each category of healthy food products. Storeowners reported that benefits would be enhanced with adjustments to programme administration and support. Specific suggestions included additional information regarding which healthy foods and beverages to stock; inventory management; handling of perishable produce; product display; modified reporting requirements and a more efficient process of delivering and maintaining equipment. CONCLUSIONS: All storeowners reported several benefits of the HFSRP and would recommend that other storeowners participate. The barriers and challenges they reported inform potential approaches to ensuring success and sustainability of the HFSRP and similar initiatives underway in other jurisdictions.

Rapid custom prototyping of soft poroelastic biosensor for simultaneous epicardial recording and imaging.

The growing need for the implementation of stretchable biosensors in the body has driven rapid prototyping schemes through the direct ink writing of multidimensional functional architectures. Recent approaches employ biocompatible inks that are dispensable through an automated nozzle injection system. However, their application in medical practices remains challenged in reliable recording due to their viscoelastic nature that yields mechanical and electrical hysteresis under periodic large strains. Herein, we report sponge-like poroelastic silicone composites adaptable for high-precision direct writing of custom-designed stretchable biosensors, which are soft and insensitive to strains. Their unique structural properties yield a robust coupling to living tissues, enabling high-fidelity recording of spatiotemporal electrophysiological activity and real-time ultrasound imaging for visual feedback. In vivo evaluations of custom-fit biosensors in a murine acute myocardial infarction model demonstrate a potential clinical utility in the simultaneous intraoperative recording and imaging on the epicardium, which may guide definitive surgical treatments.

Functional modulation of the human voltage-gated sodium channel NaV1.8 by auxiliary ß subunits.

The voltage-gated sodium channel Nav1.8 mediates the tetrodotoxin-resistant (TTX-R) Na+ current in nociceptive primary sensory neurons, which has an important role in the transmission of painful stimuli. Here, we describe the functional modulation of the human Nav1.8 α-subunit in Xenopus oocytes by auxiliary ß subunits. We found that the ß3 subunit down-regulated the maximal Na+ current amplitude and decelerated recovery from inactivation of hNav1.8, whereas the ß1 and ß2 subunits had no such effects. The specific regulation of Nav1.8 by the ß3 subunit constitutes a potential novel regulatory mechanism of the TTX-R Na+ current in primary sensory neurons with potential implications in chronic pain states. In particular, neuropathic pain states are characterized by a down-regulation of Nav1.8 accompanied by increased expression of the ß3 subunit. Our results suggest that these two phenomena may be correlated, and that increased levels of the ß3 subunit may directly contribute to the down-regulation of Nav1.8. To determine which domain of the ß3 subunit is responsible for the specific regulation of hNav1.8, we created chimeras of the ß1 and ß3 subunits and co-expressed them with the hNav1.8 α-subunit in Xenopus oocytes. The intracellular domain of the ß3 subunit was shown to be responsible for the down-regulation of maximal Nav1.8 current amplitudes. In contrast, the extracellular domain mediated the effect of the ß3 subunit on hNav1.8 recovery kinetics.

The development and evaluation of a nationwide training program for oncology health professionals in the provision of genetic testing for ovarian cancer patients.

BACKGROUND: BRCA1/2 mutation status has increasing relevance for ovarian cancer treatments, making traditional coordination of genetic testing by genetic services unsustainable. Consequently alternative models of genetic testing have been developed to improve testing at the initial diagnosis for all eligible women. METHODS: A training module to enable mainstreamed genetic testing by oncology healthcare professionals was developed by genetic health professionals. Oncology healthcare professionals completed questionnaires before and 12 months post-training to assess perceived skills, competence and barriers to their coordinating genetic testing for women with high-grade non-mucinous epithelial ovarian cancer. Genetic health professionals were surveyed 12 months post-training to assess perceived barriers to implementation of mainstreaming. RESULTS: 185 oncology healthcare professionals were trained in 42 workshops at 35 Australasian hospitals. Of the 273 tests ordered by oncology healthcare professionals post-training, 241 (93.1%) met national testing guidelines. The number of tests ordered by genetic health professionals reduced significantly (z = 45.0, p = 0.008). Oncology healthcare professionals' perceived barriers to mainstreamed testing decreased from baseline to follow-up (t = 2.39, p = 0.023), particularly perceived skills, knowledge and attitudes. However, only 58% reported either 'always' or 'nearly always' having ordered BRCA testing for eligible patients at 12 months, suggesting oncology healthcare professionals' perceived barriers were not systematically addressed through training. CONCLUSIONS: Oncology healthcare professionals have demonstrated a willingness to be involved in the provision of genetic testing in a mainstreaming model. If oncology services are to hold responsibility for coordinating genetic testing, their readiness will require understanding of barriers not addressed by training alone to inform future intervention design.

Management of radioactive waste gases from PET radiopharmaceutical synthesis using cost effective capture systems integrated with a cyclotron safety system.

The emphasis on the reduction of gaseous radioactive effluent associated with PET radiochemistry laboratories has increased. Various radioactive gas capture strategies have been employed historically including expensive automated compression systems. We have implemented a new cost-effective strategy employing gas capture bags with electronic feedback that are integrated with the cyclotron safety system. Our strategy is suitable for multiple automated 18F radiosynthesis modules and individual automated 11C radiosynthesis modules. We describe novel gas capture systems that minimize the risk of human error and are routinely used in our facility.

Dissipation of penconazole in peach, plum, apricot, and mango by HPLC-DAD.

Dissipation of penconazole was estimated in peach, plum, apricot, and mango fruits cultivated in different farms using QuEChERS method for sample preparation and High performance liquid chromatography with diode array detector. Following one application of normal dose 25 mL 100 L(-1) water, the average initial deposits of penconazole were observed to be 0.44, 0.35, 0.66 and 1.12 mg kg(-1) for peach, plum, apricot, and mango, respectively. The residues dissipated below the maximum residues limit of 0.1 mg kg(-1) after 15, 7, 10 and 21 days for peach, plum, apricot, and mango, respectively. The half-life value (T(1/2)) and pre-harvest interval of penconazole were 7.2 (12), 2.48 (12), 1.53 (7) and 4.54 (21) days for peach, plum, apricot, and mango, respectively. Thus, a waiting period of 21 days was suggested for the safe consumption of penconazole treated mango.

Dissipation of penconazole in tomatoes and soil.

Dissipation of penconazole was estimated in tomatoes fruits cultivated in field using QuEChERS method for sample preparation and high performance liquid chromatography with diode array detector. Following one application of normal dose 25 mL 100 L(-1) water, the average initial deposits of penconazole were observed to be 0.74 and 1.21 mg kg(-1) for tomatoes fruits and soil, respectively. The residues dissipated below the maximum residues limit of 0.2 mg kg(-1) after 15 days. The half-life value (T1/2) and preharvest interval of penconazole were 5.61 and 15 days, respectively. While (T1/2) of penconazole in soil was 15.51 days. Thus, a waiting period of 15 day was suggested for the safe consumption of penconazole treated Tomatoes.

Biophysical properties of Na(v) 1.8/Na(v) 1.2 chimeras and inhibition by µO-conotoxin MrVIB.

BACKGROUND AND PURPOSE: Voltage-gated sodium channels are expressed primarily in excitable cells and play a pivotal role in the initiation and propagation of action potentials. Nine subtypes of the pore-forming α-subunit have been identified, each with a distinct tissue distribution, biophysical properties and sensitivity to tetrodotoxin (TTX). Na(v) 1.8, a TTX-resistant (TTX-R) subtype, is selectively expressed in sensory neurons and plays a pathophysiological role in neuropathic pain. In comparison with TTX-sensitive (TTX-S) Na(v) α-subtypes in neurons, Na(v) 1.8 is most strongly inhibited by the µO-conotoxin MrVIB from Conus marmoreus. To determine which domain confers Na(v) 1.8 α-subunit its biophysical properties and MrVIB binding, we constructed various chimeric channels incorporating sequence from Na(v) 1.8 and the TTX-S Na(v) 1.2 using a domain exchange strategy. EXPERIMENTAL APPROACH: Wild-type and chimeric Na(v) channels were expressed in Xenopus oocytes, and depolarization-activated Na⁺ currents were recorded using the two-electrode voltage clamp technique. KEY RESULTS: MrVIB (1 µM) reduced Na(v) 1.2 current amplitude to 69 ± 12%, whereas Na(v) 1.8 current was reduced to 31 ± 3%, confirming that MrVIB has a binding preference for Na(v) 1.8. A similar reduction in Na⁺ current amplitude was observed when MrVIB was applied to chimeras containing the region extending from S6 segment of domain I through the S5-S6 linker of domain II of Na(v) 1.8. In contrast, MrVIB had only a small effect on Na⁺ current for chimeras containing the corresponding region of Na(v) 1.2. CONCLUSIONS AND IMPLICATIONS: Taken together, these results suggest that domain II of Na(v) 1.8 is an important determinant of MrVIB affinity, highlighting a region of the α-subunit that may allow further nociceptor-specific ligand targeting.

A novel mechanism of inhibition of high-voltage activated calcium channels by α-conotoxins contributes to relief of nerve injury-induced neuropathic pain.

α-Conotoxins that are thought to act as antagonists of nicotinic acetylcholine receptors (nAChRs) containing α3-subunits are efficacious in several preclinical models of chronic pain. Potent interactions of Vc1.1 with other targets have suggested that the pain-relieving actions of α-conotoxins might be mediated by either α9α10 nAChRs or a novel GABA(B) receptor-mediated inhibition of N-type calcium channels. Here we establish that three α-conotoxins, Vc1.1, AuIB and MII have distinct selectivity profiles for these three potential targets. Their potencies after intramuscular administration were then determined for reversal of allodynia produced by partial nerve ligation in rats. Vc1.1, which potently inhibits α9α10 nAChRs and GABA(B)/Ca(2+) channels but weakly blocks α3ß2 and α3ß4 nAChRs, produced potent, long-lasting reversal of allodynia that were prevented by pre-treatment with the GABA(B) receptor antagonist, SCH50911. α-Conotoxin AuIB, a weak α3ß4 nAChR antagonist, inhibited GABA(B)/Ca(2+) channels but did not act on α9α10 nAChRs. AuIB also produced reversal of allodynia. These findings suggest that GABA(B) receptor-dependent inhibition of N-type Ca(2+) channels can mediate the sustained anti-allodynic actions of some α-conotoxins. However, MII, a potent α3ß2 nAChR antagonist but inactive on α9α10 and α3ß4 nAChRs and GABA(B)/Ca(2+) channels, was demonstrated to have short-acting anti-allodynic action. This suggests that α3ß2 nAChRs may also contribute to reversal of allodynia. Together, these findings suggest that inhibition of α9α10 nAChR is neither necessary nor sufficient for relief of allodynia and establish that α-conotoxins selective for GABA(B) receptor-dependent inhibition of N-type Ca(2+) channels relieve allodynia, and could therefore be developed to manage chronic pain.

Effect of lysine supplementation on health and morbidity in subjects belonging to poor peri-urban households in Accra, Ghana.

BACKGROUND: Lysine affects diarrhea and anxiety via effects on serotonin receptors, enhanced intestinal repair, and sodium chloride-dependent opioid peptide transport. OBJECTIVE: The objective was to investigate the effects of lysine supplementation on morbidity, growth, and anxiety in children and adults of peri-urban areas of Accra, Ghana. DESIGN: In a double-blind randomized trial, the effect of lysine supplementation (1 g lysine/d) compared with that of placebo was examined in 2 groups of men, women, and children (n = 271). Primary outcomes included diarrheal and respiratory morbidity, growth, and anxiety and complement C3, C-reactive protein, serum cortisol, transferrin, and ferritin values. Independent-sample t tests, odds ratios, generalized estimating equations, 4-parameter sinusoid regression, and generalized linear models were used. RESULTS: Thirty percent of men, 50% of women, and 15% of children were at risk of lysine inadequacy. Supplementation in children reduced diarrheal episodes [19 lysine, 35 placebo; odds ratio (OR): 0.52; 95% CI: 0.29, 0.92; P = 0.046] and the total number of days ill (21 lysine, 47 placebo; OR: 0.44; 95% CI: 0.26, 0.74; P = 0.034). Mean days ill per child per week (0.058 ± 0.039 lysine, 0.132 ± 0.063 placebo; P = 0.017) were negatively associated with weight gain with control for baseline weight and study group (P = 0.04). Men had fewer coryza episodes (23 lysine, 39 placebo; OR: 0.60; 95% CI: 0.36, 1.01; P = 0.05), total number of days ill (lysine: 130; placebo: 266; OR: 0.51; 95% CI: 0.28, 0.93; P = 0.03), and mean days ill per person per week (lysine: 0.21 ± 0.23; placebo: 0.41 ± 0.35; P = 0.04). Serum ferritin (P = 0.045) and C-reactive protein (P = 0.018) decreased in lysine-supplemented women but increased in placebo-supplemented women. CONCLUSION: Lysine supplementation reduced diarrheal morbidity in children and respiratory morbidity in men in Ghana.

INCAP studies of kwashiorkor and marasmus.

This article summarizes thirty years of intensive clinical metabolic and therapeutic studies of the consequences of severe protein deficiency relative to calories, which results in kwashiorkor, and of a balanced deficiency of protein and calories that results in marasmus. Evidence is provided that these are two different metabolic diseases, but kwashiorkor is usually superimposed on some degree of chronic marasmus and hence most cases studied were marasmic kwashiorkor. The value of the creatinine/height index to indicate the degree of lean body cell mass with any disease is demonstrated.

INCAP studies of nutrition and infection.

As soon as the Institute of Nutrition of Central America and Panama (INCAP) began to study the poor nutritional status and stunting of children in the rural villages of Central America, it was apparent that infections, particularly diarrheas, were also a serious problem. Studies of kwashiorkor indicated that infections precipitated kwashiorkor and anemia in children who were already malnourished. In the 1940s there was almost no suggestion in the literature of a relation between nutrition and infection. INCAP gradually identified the mechanisms by which any infection worsens nutritional status and demonstrated that infections were more severe and more often fatal in malnourished children and adults. These studies ultimately led to the 1968 World Health Organization (WHO) monograph "Interactions of nutrition and infection" and widespread recognition by public health workers of the importance of this relationship for morbidity and mortality in poorly nourished populations.

INCAP studies of endemic goiter and its prevention.

The high prevalence of goiter among adults in its member countries of Central America and Panama was observed as soon as INCAP began field studies. This led to systematic studies of goiter in schoolchildren in all of the countries as described, beginning with Guatemala where the rate was 38% nationally. However, efforts to eliminate the consequences of iodine with iodized salt using the water soluble potassium iodate and a process that had proved successful in Switzerland and the United States could not be used with the crude moist salt of the region. INCAP identified potassium iodate that is insoluble in water, and in four schools (two each in El Salvador and Guatemala) proved that the iodine in this compound was as available as that in potassium iodate. It remained evenly distributed in moist salt. When added to salt in Guatemala, goiter rate dropped to 15% in four years and less than 5% in eight years. Compulsory iodation of salt in other developing countries followed with comparable results. This method is now used in worldwide campaigns against iodine deficiency in developing countries.