Foot callus thickness does not trade off protection for tactile sensitivity during walking.

Until relatively recently, humans, similar to other animals, were habitually barefoot. Therefore, the soles of our feet were the only direct contact between the body and the ground when walking. There is indirect evidence that footwear such as sandals and moccasins were first invented within the past 40 thousand years1, the oldest recovered footwear dates to eight thousand years ago2 and inexpensive shoes with cushioned heels were not developed until the Industrial Revolution3. Because calluses-thickened and hardened areas of the epidermal layer of the skin-are the evolutionary solution to protecting the foot, we wondered whether they differ from shoes in maintaining tactile sensitivity during walking, especially at initial foot contact, to improve safety on surfaces that can be slippery, abrasive or otherwise injurious or uncomfortable. Here we show that, as expected, people from Kenya and the United States who frequently walk barefoot have thicker and harder calluses than those who typically use footwear. However, in contrast to shoes, callus thickness does not trade-off protection, measured as hardness and stiffness, for the ability to perceive tactile stimuli at frequencies experienced during walking. Additionally, unlike cushioned footwear, callus thickness does not affect how hard the feet strike the ground during walking, as indicated by impact forces. Along with providing protection and comfort at the cost of tactile sensitivity, cushioned footwear also lowers rates of loading at impact but increases force impulses, with unknown effects on the skeleton that merit future study.

Corn-Based Fluorescent Light-Up Biosensors with Improved Signal-to-Background Ratio for Label-Free Detection of Long Noncoding RNAs.

Long noncoding RNAs (lncRNAs) play pivotal roles in multifarious physiological and pathological processes, and their aberrant expression may disturb the normal regulatory network of gene expression to induce diverse human diseases. Herein, we construct a fluorescent light-up biosensor with a low background for label-free detection of lncRNAs by coupling duplex-specific nuclease (DSN)-assisted target recycling amplification with transcription-driven synthesis of fluorogenic RNA aptamer-Corns. We design two linear probes, including a capture probe for initiating a cyclic cleavage reaction and a linear template for transcribing RNA aptamer-Corn. Target lncRNA is recognized by capture probes assembled on magnetic bead (MB) surfaces to trigger a DSN-assisted cyclic cleavage reaction, releasing abundant T7 promoter sequences. After magnetic separation, free T7 promoter hybridizes with a linear template to induce efficient transcription amplification with the assistance of T7 RNA polymerase, producing numerous fluorogenic RNA aptamer-Corns that can light up small-molecule fluorogens 3,5-difluoro-4-hydroxybenzylidene-imidazolinone-2-oxime (DFHO). Notably, the introduction of MBs facilitates both the separation of cleaved capture probes and the enrichment/isolation of target lncRNAs from the complex biological matrix. Benefiting from the high efficiency of DSN/T7 RNA polymerase-mediated cascade amplification and high signal-to-background ratio of the Corn-DFHO complex, this biosensor is capable of sensitively quantifying lncRNA with a detection limit of 31.98 aM. Moreover, it can precisely quantify lncRNA at the single-cell level and even in complex biological samples, and it can differentiate tumor cells from normal cells. Importantly, this Corn-based biosensor is readily extended to detect other lncRNAs by altering capture probe sequences, opening a new avenue for molecular diagnosis.

Mutation, food-grade expression, and characterization of a lactonase for zearalenone degradation.

Zearalenone (ZEN) is a mycotoxin that causes serious threats to human health. People are exposed to ZEN contamination externally and internally through many ways, while environmental-friendly strategies for efficient elimination of ZEN are urgently needed worldwide. Previous studies revealed that the lactonase Zhd101 from Clonostachys rosea can hydrolyze ZEN to low toxicity compounds. In this work, the enzyme Zhd101 was conducted with combinational mutations to enhance its application properties. The optimal mutant (V153H-V158F), named Zhd101.1, was selected and introduced into the food-grade recombinant yeast strain Kluyveromyces lactis GG799(pKLAC1-Zhd101.1), followed by induced expression and secretion into the supernatant. The enzymatic properties of this mutant were extensively examined, revealing a 1.1-fold increase in specific activity, as well as improved thermostability and pH stability, compared to the wild-type enzyme. The ZEN degradation tests and the reaction parameters optimization were carried out in both solutions and the ZEN-contaminated corns, using the fermentation supernatants of the food-grade yeast strain. Results showed that the degradation rates for ZEN by fermentation supernatants reached 96.9% under optimal reaction conditions and 74.6% in corn samples, respectively. These new results are a useful reference to zearalenone biodegradation technologies and indicated that the mutant enzyme Zhd101.1 has potential to be used in food and feed industries. KEY POINTS: • Mutated lactonase showed 1.1-fold activity, better pH stability than the wild type. • The strain K. lactis GG799(pKLAC1-Zhd101.1) and the mutant Zhd101.1 are food-grade. • ZEN degradation rates by supernatants reached 96.9% in solution and 74.6% in corns.

Utility of Thermographic Imaging for Callus Identification in Wound and Foot Care.

Calluses are thickened skin areas that develop due to repeated friction, pressure, or other types of irritation. While calluses are usually harmless and formed as a protective surface, they can lead to skin ulceration or infection if left untreated. As calluses are often not clearly visible to the patients, and some areas of dead skin can be missed during debridement, accessory tools can be useful in assessment and follow-up. The practical question addressed in this article is whether or not thermal imaging adds value to callus assessment. We have performed a theoretical analysis of the feasibility of thermographic imaging for callus identification. Our analytical calculations show that the temperature drop in the epidermis should be on the order of 0.1 °C for the normal epidermis in hairy skin, 0.9 °C for glabrous skin, and 1.5-2 °C or higher in calluses. We have validated our predictions on gelatin phantoms and demonstrated the feasibility of thermographic imaging for callus identification in two clinical case series. Our experimental results are in agreement with theoretical predictions and support the notion that local skin temperature variations can indicate epidermis thickness variations, which can be used for callus identification. In particular, a surface temperature drop on the order of 0.5 °C or more can be indicative of callus presence, particularly in callus-prone areas. In addition, our analytical calculations and phantom experiments show the importance of ambient temperature measurements during thermographic assessments.

Study on the phenolic composition and antioxidant properties of white-, yellow-, and black-corn (Zea mays L.) foodstuffs.

BACKGROUND: Black corn possesses potent antioxidants, but these are mostly lost during processing. In this study we evaluated the antioxidant content of two different black ('Millo Corvo') corn-based products (i.e. tortillas and cookies) subject to moderate processing. A parallel study on white and yellow corns was carried out for comparison. RESULTS: Raw 'Millo Corvo' flour exhibited higher contents of phenolic acids, flavonoids, and particularly anthocyanins than white and yellow flours did. Phenolic acids decreased in cookies but did not in tortillas; flavonoids did not exhibit a clear tendency, and anthocyanins were always preserved. Antioxidant activity (AA) obtained for 'Millo Corvo' samples was twice as high as the value measured in white and yellow corns in terms of 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. The difference in AA was even more remarkable in terms of photochemiluminiscence antiradical activity. The conditions used during the cookie-making process enabled the natural antioxidant characteristics of 'Millo Corvo' to be preserved. However, the conditions applied to prepare tortillas resulted in major losses. CONCLUSIONS: The initial phenolics, in particular anthocyanins, and AA of 'Millo Corvo' flour can be maintained during processing as long as the conditions applied are 183 °C for 20 min in the absence of a high water content. Millo corvo products possess improved antioxidant characteristics compared with those from white and yellow corns. Millo corvo is a promising black corn type to prepare health-promoting corn-based foodstuffs. © 2023 Society of Chemical Industry.

A two-year study on the occurrence and concentration of mycotoxins in corn varieties with different endosperm textures.

BACKGROUND: Mycotoxin monitoring in cereal grains has great importance in the food and feed industries. This study evaluated mycotoxin contamination in corns with different endosperm textures in 2 years of cultivation. Samples of dent, semi-dent, flint and semi-flint corns from field experiments were analyzed by high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). RESULTS: Occurrences of fumonisins B1 (FB1 ) and B2 (FB2 ) in 2020 were 45.72% (mean 270 µg kg-1 ) and 35.89% (94.97 µg kg-1 ), respectively, and 68.98% (446 µg kg-1 ) and 45.83% (152 µg kg-1 ) in 2021. Occurrence of aflatoxin B1 was 11.96% (0.16 µg kg-1 ) in 2020 and 11.11% (0.13 µg kg-1 ) in 2021. In 2020, deoxynivalenol (DON) and zearalenona (ZEA) presented occurrences of 1.28% and 1.70%, with means of 4.08 and 2.45 µg kg-1 , respectively. In 2021, results were 8.33% (31.00 µg kg-1 ) for DON and 8.79% (4.38 µg kg-1 ) for ZEA. Citrinin, diacetoxyscirpenol and fusarenon-X did not occur in 2020 but presented 1.66%, 0.83%, and 2.50% positive rates in 2021, respectively. In 2020, flint corn presented the lowest concentration of FB1 whereas dent corn presented the highest concentration of FB1 and FB2 (P < 0.05). In 2021, dent corn presented the highest means of FB1 , FB2 and diacetoxyscirpenol (P < 0.05). Dent and semi-dent presented the highest concentration of nivalenol (P < 0.05). CONCLUSION: The endosperm texture influenced mycotoxin contamination in corn grains, especially FB1 and FB2 , which had the highest concentration in dent corn in the 2 years of this study. © 2023 Society of Chemical Industry.

Radiographic factors associated with painful callosities after forefoot surgery in patients with rheumatoid arthritis.

OBJECTIVES: Operative procedures for rheumatoid forefoot deformities have gradually changed from arthrodesis or resection arthroplasty to joint-preserving surgery. Although joint-preserving arthroplasty has yielded good outcomes, painful plantar callosities may occur post-operatively. This study aimed to reveal the radiographic factors associated with painful callosities after joint-preserving surgery for forefoot deformities in patients with rheumatoid arthritis (RA). METHODS: We retrospectively evaluated 166 feet in 133 patients with RA who underwent forefoot joint-preserving arthroplasty, including proximal rotational closing-wedge osteotomies of the first metatarsal, between January 2012 and December 2015. Logistic regression analysis was performed with the objective variable set as the presence/absence of painful plantar callosities at the final observation and the explanatory variables set as several radiographic factors, including post-operative relative first metatarsal length (RML), amount of dorsal dislocation of the fifth metatarsal (5DD), and arc failure of the lesser toes. RESULTS: At the final follow-up, 42 of the 166 feet (25.3%) had painful callosities under the metatarsal heads post-operatively. Logistic regression analysis showed that the RML, 5DD, and lesser toes' arc failure were significantly associated with painful callosities. CONCLUSIONS: We identified that RML, 5DD, and arc failure of the lesser toes were associated with painful plantar callosities after the surgery.

Joint preserving procedures for painful plantar callosities in patients with flexible cavovarus foot.

BACKGROUND: The outcome of a constant joint preserving procedure for painful plantar callosities with cavovarus foot remains unclear. METHODS: Eleven patients (11 feet) who underwent lateral displacement calcaneal osteotomy (LDCO), dorsiflexion first metatarsal osteotomy (DFMO), and plantar fasciotomy (PF), simultaneously were included. The presence of painful callosities, heel alignment of standing (HA), and the Japanese Society for Surgery of the Foot ankle/hindfoot (JSSF) score were evaluated. Radiographically, the talonavicular coverage angle (TNCA), lateral talo-first metatarsal angle (LTMA), calcaneal pitch angle (CPA), and heel alignment angle (HAA) were measured. RESULTS: Postoperatively, painful plantar callosities disappeared in 10 patients and remained in one patient. The postoperative HA and JSSF score significantly improved. The postoperative TNCA, LTMA, CPA, and HAA significantly improved. CONCLUSIONS: In patients with flexible cavovarus foot, LDCO, DFMO, and PF yielded good outcomes at mid-term follow-up with preservation of the foot and ankle joints.

A prospective study on surgical management of foot deformities in Charcot Marie tooth disease.

Foot deformities are frequently observed in patients with Charcot Marie tooth disease (CMT) and orthopaedic surgery is often required. Currently there is no evidence-based guideline on surgical management and only a few studies which have evaluated long-term outcomes of surgical procedures. The aim of the study was to evaluate longitudinally the effect of foot surgery in a cohort of CMT patients. Twenty-five CMT adult patients were assessed using a comprehensive group of validated scales and questionnaires before and after surgery. A wide range of surgical procedures was performed by one team of dedicated foot ankle orthopaedic surgeons. Foot alignment as measured by the foot posture index, pain, quality of life and callosities significantly improved after one year and the improvement was maintained up to 4 years after surgery. There was a trend towards a reduction in the number of falls post-operatively. Surgery had no effect on fatigue, balance and CMT examination score. Our findings showed significant improvement of pain, foot alignment, callosities and quality of life after surgery and suggested that foot deformity correction in adults with CMT performed in a specialised foot and ankle unit is beneficial.

Relationship Between Plantar Callosity and Foot Deformity in Hallux Valgus Using Weightbearing Computed Tomography.

Plantar callosities under lesser metatarsals are often accompanied by the hallux valgus, and the cause of callosity is thought to be associated with the foot deformity, such as the metatarsal length discrepancy, the abnormal metatarsal head height, cavus, flat foot, and rheumatoid conditions. However, it is unclear which variable is most involved in the cause of callosity in hallux valgus deformity. To clarify the factors associated with the callosity with hallux valgus deformity, we conducted multiple image assessments based on weightbearing radiography and computed tomography. A retrospective review was performed based on the collection of clinical records from all patients with hallux valgus treated from 2010 to 2019 in our institution. We measured the hallux valgus angle, intermetatarsal angles, calcaneal pitch angles, talo-first metatarsal angles, metatarsal length, metatarsal head height, first metatarsal pronation angles, and sesamoid position with weightbearing radiography and computed tomography. We analyzed the relation between callosity formation and imaging assessments using univariate and multivariate logistic regression models. Fifty feet were retrospectively evaluated, and multiple logistic analyses by the stepwise method revealed that the first metatarsal-lateral-sesamoid distance was the only radiographical variable associated with callosity formation among all the tested variables (p < .001). As the grade of the callosity became more severe, the lateral shift of the lateral sesamoid increased. The position of the sesamoid bone appears to have a critical role in the assessment and choice of treatment protocols and further research needs to be conducted on the relationship with the position of sesamoid bone to elucidate the mechanism of callus formation.

Periwound skin care considerations for older adults.

This article discusses the effects of ageing on the skin, particularly the main structural and functional changes that occur in the epidermis and dermis that make the skin more vulnerable to damage. Specific alterations that occur with ageing include slower epidermal turnover, flattening of the epidermal-dermal junction, loss of moisture and hydration as well as reduced immunity placing the skin at increased risk of damage. The discussion will also examine common periwound complications associated with ageing including; maceration, excoriation, dry skin, hyperkeratosis, callus, contact dermatitis and eczema. Strategies to manage these problems and interventions to reduce the risk of these complications include moisturising the skin to make it more resilient, debriding keratinised and callus tissue in the periwound area, appropriate choice of dressings to manage excessive exudate, careful removal of dressings as well as treating inflammatory conditions of the periwound skin.

Association between teat-end hyperkeratosis and mastitis in dairy cows: A systematic review.

A systematic review was conducted to elucidate the role of teat-end hyperkeratosis (THK) as a risk factor for clinical mastitis (CM) or subclinical mastitis (SCM). Scientific papers on the subject were identified by means of a database search. All types of peer-reviewed analytical studies, observational or experimental and published in English, could be included in the review, regardless of publication year. Of 152 identified records, 18 articles were selected, of which 8 were prospective cohort studies, 9 were cross-sectional, and 1 was a hybrid case-control study. Internal validity of studies was assessed using a score system ranging from 0 to 6, based on design, risk of bias, and statistical methods. The most frequent study limitation was improper use of statistical methods to avoid confounding of associations between THK and CM or SCM. The 3 studies that used CM as outcome (all with high validity scores) showed positive associations with THK (especially severe), although the magnitude and statistical significance of the estimates differed among them. Most studies that used SCM as the primary outcome (based on microbiological examination of milk) reported that only severe THK was associated with SCM. Two studies with high validity scores reported moderate to strong associations between severe THK and incidence or prevalence of Staphylococcus aureus intramammary infection. Two studies with high validity scores reported that only severe THK was associated with the risk of somatic cell count (SCC) ≥200,000 cells/mL and increased mean SCC, respectively. Although 4 cross-sectional studies reported positive associations between THK and SCC, these associations were possibly spurious because confounding factors, such as parity, were not considered in the analyses. Results of the reviewed studies suggest that severe THK is a risk factor for both CM and SCM, as defined by microbiological examination of milk, SCC thresholds, or mean SCC. The effect of severe THK on both contagious (especially Staphylococcus aureus) and environmental CM or SCM emphasizes the importance of teat health for mastitis control. Four studies demonstrated that quarters with mild THK had lower prevalence of intramammary infection or lower mean SCC than quarters with no THK, suggesting that development of mild THK, as a physiological response to milking, can have a protective effect. Dairy consultants should focus on monitoring and minimizing occurrence of severe THK to prevent CM and SCM.

Relationship of callosities of the forefoot with foot deformity, Health Assessment Questionnaire Disability Index, and joint damage score in patients with rheumatoid arthritis.

Objectives: We aimed to investigate the relationship of callosities of the forefoot with foot deformity, the Health Assessment Questionnaire Disability Index (HAQ-DI) and modified total Sharp score (TSS) in patients with rheumatoid arthritis (RA).Methods: A total of 202 patients and 404 feet were enrolled. We examined the prevalence of callosities. Clinical data included the HAQ-DI, TSS, hallux valgus angle (HVA), and calcaneal pitch angle (CPA). The analysis of factors associated with callosities of the forefoot was performed by comparing patients with and without callosities of the forefoot.Results: The prevalence of callosities was 31.2% of all patients and 24.0% of all feet. The patients with callosities of the forefoot had significantly higher TSS of the foot. The presence of callosities affected the HAQ-DI walking score. HVA and CPA were identified as being associated with callosities of the forefoot. Analyzing from the cutoff values, the odds ratios of HVA, CPA, and HVA and (combined) CPA were 4.64, 1.73, and 2.99, respectively.Conclusion: Hallux valgus and flatfoot were related to callosities of the forefoot in RA. This study suggested that to prevent callosities of the forefoot, early diagnosis and foot care for hallux valgus and flatfoot are needed in daily practice.

Successful Treatment of Plantar Hyperkeratosis in the Form of Recurrent Corns With Split-Thickness Sole Skin Graft.

INTRODUCTION: Plantar hyperkeratosis, such as corns and calluses, is common in older people and associated with pain, mobility impairment, and functional limitations. It usually develops on the palms, knees, or soles of feet, especially under the heels or balls. There are several treatment methods for plantar hyperkeratosis, such as salicylic acid plaster and scalpel debridement, and conservative modalities, such as using a shoe insert and properly fitting shoes. METHODS: We present an effective method of reconstructing the wound after corn excision using a split-thickness sole skin graft (STSSG). We harvested the skin graft from the arch of the sole using the dermatome with a skin thickness of 14/1000th inches. RESULTS: Because the split-thickness skin graft, harvested from the sole arch near the distal sole, is much thicker than the split-thickness skin graft from the thigh, it is more resistant to weight and friction. The healed wound with STSSG coverage over the distal sole was intact, and the donor site over the sole arch had healed without complication during the outpatient follow-up, 3 months after surgery. CONCLUSIONS: The recovery time of STSSG for corn excision is shorter than that with traditional treatment. Therefore, STSSG can be a reliable alternative treatment for recurrent palmoplantar hyperkeratosis.

Examination of the Effect of Suitable Size of Shoes under the Second Metatarsal Head and Width of Shoes under the Fifth Metatarsal Head for the Prevention of Callus Formation in Healthy Young Women.

Excessive pressure and shear stress while walking cause a risk of callus formation, which eventually causes foot ulcers in patients with diabetes mellitus. Callus under the second metatarsal head (MTH) has been associated with increased shear stress/pressure ratios (SPR). Callus under the fifth MTH has been associated with increased peak shear stress (PSS). The purpose of this study is to examine whether the effect of the suitable size and width of shoes prevents diabetic foot ulcers under the second and fifth MTH. We measured the pressure and shear stress by testing three kinds of sizes and two types of width of shoes. Significant difference was not observed in the SPR under the second MTH among different sizes of shoes. However, the pressure and shear stress were significantly lower when putting on shoes of fit size compared with larger sizes. The PSS under the fifth MTH was significantly smaller when putting on shoes of fit width compared with those of narrow width. Wearing shoes of fit size and width has the potential to prevent callus formation by reducing the pressure and shear stress constituting SPR under the second MTH and PSS under the fifth MTH.

The management and treatment of hyperkeratosis.

Rebecca Elwell, Macmillan Lymphoedema Advanced Nurse Practitioner, Royal Stoke University Hospital, discusses recommendations on management of this skin problem, which may co-occur with chronic oedema.

Estimate of genetic gain in popcorn after cycles of phenotypic recurrent selection.

Popcorn is widely consumed in Brazil, yet there are few breeding programs for this crop. Recurrent selection (RS) is a viable breeding alternative for popcorn; however, the gains achieved must be frequently checked. The aim of this study was to assess the effect of selection for grain type (round and pointed) after four cycles of phenotypic RS on the main agronomic traits of popcorn, to estimate the genetic gain achieved for the trait of expansion volume (EV), and to obtain estimates of phenotypic correlations for the main traits of the crop in the UFLA E and UFLA R populations. The zero, one, two, and three cycles of the UFLA E and UFLA R populations, the fourth cycle, and the controls IAC-112 and IAC-125 were used. The experiments were conducted at the experimental farm of Universidade Federal de Lavras (UFLA; Environment 1) and at the experimental area of the Genetics and Plant Breeding Sector of the Department of Biology at UFLA (Environment 2) in the 2010/11 crop season. Nine agronomic traits were evaluated, including EV and grain yield (GY). The UFLA R and UFLA E populations showed similar behavior for all evaluated traits. The type of grain did not affect the genetic gain for EV, which was 5 and 3.7% in each cycle carried out in the UFLA E and UFLA R population, respectively. Phenotypic selection carried out during recombination for EV is an effective method for increasing expression of the trait. EV and GY did not show a linear association.