The 3D scanner for measuring body surface area: a simplified calculation in the Chinese adult

Metformin administration in prevention of colorectal polyps in type 2 diabetes mellitus patients

BACKGROUND

Colorectal polyps are frequently observed in patients with type 2 diabetes mellitus (DM), posing a significant risk for colorectal cancer. Metformin, a widely prescribed biguanidine drug for type 2 DM, has been suggested to have potential chemoprophylactic effects against various cancers.

AIM

To explore the correlation between colorectal polyps and metformin use in type 2 DM patients.

METHODS

Type 2 DM patients were categorized into polyp and non-polyp groups. Following this, all patients were categorized into the type 2 DM-metformin, type 2 DM-non-metformin, and non-type 2 DM groups. Based on the baseline colonoscopy results, we performed pairwise comparisons of the incidence of colorectal polyps among the three groups. Additionally, we analyzed the relationship between colorectal polyps and the duration of metformin use and between the size and number of polyps and metformin use. Simultaneously, we focused on the specific pathological types of polyps and analyzed their relationship with metformin use. Finally, we compared the incidence of polyps between metformin and non-metformin groups according to the interval colonoscopy results.

RESULTS

The rate of metformin use in patients with colorectal polyps was 0.502 times that of patients without colorectal polyps [odds ratio (OR) = 0.502, 95% confidence interval (CI): 0.365-0.689; P < 0.001]. The incidence of colorectal polyps did not differ significantly between the type 2 DM-metformin and non-type 2 DM groups (P > 0.05). Furthermore, the correlations between the duration of metformin use and the incidence of colorectal polyps and between the size and number of polyps and metformin use were not statistically significant (P > 0.05). Metformin use did not affect the incidence of colorectal polyps during interval colonoscopy (P > 0.05).

CONCLUSION

Metformin use and colorectal polyp incidence in type 2 DM patients showed a negative correlation, independent of the hypoglycemic effect of metformin.

Effect of laparoscopic handle size on surgical performance: A randomized crossover trial

Laparoscopic instrument handles design and dimensions are crucial to determine the configuration of surgeons' hand grip and, therefore, can have a deleterious effect on overall surgical efficiency and surgeons' comfort. The aim of this study is to investigate the impact of laparoscopic handle size and hand surface area on surgical task performance. A single-blind, randomized crossover trial was carried out with 29 novice medical students. Participants performed three simulated tasks in "black box" simulators using two scissor-type handles of different sizes. Surgical performance was assessed by the number of errors and time required to complete each task. Hand anthropometric data were measured using a 3D scanner. Execution time was significantly higher when cutting and suturing tasks were performed with the smaller handle. In addition, hand surface area was positively correlated with peg transfer task time when performed with the standard handle and was correlated with cutting task time in small and standard handle groups. We also found positive correlations between execution time and the number of errors executed by larger-handed participants. Our findings indicate that laparoscopic handle size and hand area influence surgical performance, highlighting the importance of considering hand anthropometry variances in surgical instrument design.

Accreditation of the handheld 3-dimensional scanner and conventional photo images for area measurement

Accurate assessment of wound areas is crucial in making therapeutic decisions, as the prognosis and changes in the size of the wound over time play a significant role. An ideal assessment method should possess qualities such as speed, affordability, accuracy, user-friendliness for both patients and healthcare professionals, and suitability for daily clinical practice. This study aims to introduce a handheld 3-dimensional (3D) scanner and evaluate its accuracy in measuring wound areas. Engineers from the Industrial Technology Research Institute in Taiwan developed a handheld 3D scanner with the intention of extending its application to the medical field. A project was conducted to validate the accuracy of this 3D scanner. We utilized a smartphone (Asus ZenFone 2 with a 13-million-pixel rear camera), a digital single-lens reflex digital camera (Nikon, D5000, Tokyo, Japan), and the 3D scanner to repeatedly measure square papers of known size that were affixed to the curved surface of life-size facial mask or medical teaching breast models. The "Image J" software was employed for 2-dimensional image measurements, while the "3D Edit" software was used to assess the "area of interest" on 3D objects. By using square papers with predetermined dimensions, the measurement-associated error rate (ER) could be calculated for each image. Three repeated measurements were performed using the "Image J" software for each square paper. The ERs of the 3D scan images were all below 3%, with an average ER of 1.64% in this study. The close-up mode of the smartphone exhibited the highest ER. It was observed that as the area increased, the ER also increased in the digital single-lens reflex camera group. The extension distortion effect caused by the wide-angle lens on the smartphone may increase the ER. However, the definition of a healthy skin edge may vary, and different algorithms for calculating the measurement area are employed in various 3D measurement software. Therefore, further validation of their accuracy for medical purposes is necessary. Effective communication with software engineers and discussions on meeting clinical requirements are crucial steps in enhancing the functionality of the 3D scanner.

Associations of Three-Dimensional Anthropometric Body Surface Scanning Measurements and Coronary Artery Disease

Background and Objectives: The relationship between three-dimensional (3D) scanning-derived body surface measurements and biomarkers in patients with coronary artery disease (CAD) were assessed. Methods and Methods: The recruitment of 98 patients with CAD confirmed by cardiac catheterization and 98 non-CAD patients were performed between March 2016 and December 2017. A health questionnaire on basic information, life style variables, and past medical and family history was completed. 3D body surface measurements and biomarkers were obtained. Differences between the two groups were assessed and multivariable analysis performed. Results: It was found that chest width (odds ratio [OR] 0.761, 95% confidence interval [CI] = 0.586–0.987, p = 0.0399), right arm length (OR 0.743, 95% CI = 0.632–0.875, p = 0.0004), waist circumference (OR 1.119, 95% CI = 1.035–1.21, p = 0.0048), leptin (OR 1.443, 95% CI = 1.184–1.76, p = 0.0003), adiponectin (OR 0.978, 95% CI = 0.963–0.994, p = 0.006), and interleukin 6 (OR 1.181, 95% CI = 1.021–1.366, p = 0.0254) were significantly associated with CAD. The combination of biomarker scores and body measurement scores had the greatest area under the curve and best association with CAD (area under the curve of 0.8049 and 95% CI = 0.7440–0.8657). Conclusions: Our study suggests that 3D derived body surface measurements in combination with leptin, adiponectin, and interleukin 6 levels may direct us to those at risk of CAD, allowing a non-invasive approach to identifying high-risk patients.

Chemotherapy and Anticancer Drugs Adjustment in Obesity: A Narrative Review

BACKGROUND

Obese individuals have higher rates of cancer incidence and cancer- related mortality. The worse chemotherapy outcomes observed in this subset of patients are multifactorial, including the altered physiology in obesity and its impact on pharmacokinetics, the possible increased risk of underdosing, and treatment-related toxicity.

AIMS

The present review aimed to discuss recent data on physiology, providing just an overall perspective and pharmacokinetic alterations in obesity concerning chemotherapy. We also reviewed the controversies of dosing adjustment strategies in adult and pediatric patients, mainly addressing the use of actual total body weight and ideal body weight.

METHODS

This narrative review tried to provide the best evidence to support antineoplastic drug dosing strategies in children, adolescents, and adults.

RESULTS

Cardiovascular, hepatic, and renal alterations of obesity can affect the distribution, metabolism, and clearance of drugs. Anticancer drugs have a narrow therapeutic range, and variations in dosing may result in either toxicity or underdosing. Obese patients are underrepresented in clinical trials that focus on determining recommendations for chemotherapy dosing and administration in clinical practice. After considering associated comorbidities, the guidelines recommend that chemotherapy should be dosed according to body surface area (BSA) calculated with actual total body weight, not an estimate or ideal weight, especially when the intention of therapy is the cure.

CONCLUSION

The actual total body weight dosing appears to be a better approach to dosing anticancer drugs in both adults and children when aiming for curative results, showing no difference in toxicity and no limitation in treatment outcomes compared to adjusted doses.

Regular Tennis Exercise May Improve the Vascular Endothelial Function in Postmenopausal Women: The Influence of Hemodynamics

Physical inactivity plays a role in the incidence of cardiovascular disease (CVD). Although the current guidelines for physical activity, such as the prescription of exercise, seek to combat CVD, attaining the recommended targets remains challenging. Tennis exercise has been proven to have a unique advantage in reducing the mortality of CVD, but little is known about the influence of playing tennis on impaired vascular endothelial function (VEF), which initiates CVD. Thus, this study aimed to investigate whether regular tennis participation could protect the VEF better than merely meeting the physical activity recommended by the current guidelines. A cross-sectional design was performed based on a sample of 38 healthy postmenopausal women who were matched for physical activity, of which 17 subjects had long-term tennis experience and 21 age-matched subjects regularly exercised but did not play tennis. The cardiovascular function and the body composition of all subjects were measured. We used cluster analysis to assess the overall health status. The modeling results showed that the tennis players performed better in terms of VEF than the nonplayers (10.55 ± 0.58 vs. 8.69 ± 0.52, p < 0.01, R²_ad = 0.367), while the wall shear stress positively correlated with VEF (r = 0.505, p < 0.05), after controlling for age and physical activity levels. Regular tennis exercise may be a protective factor for VEF, and further study should be performed to research the role of hemodynamics in tennis exercise.

Exposed Body Surface Area-A Determinate for UV Radiant Energy in Human UV Exposure Studies

Solar ultraviolet (UV) exposure of people and related health risk is mainly examined by estimating the received UV radiant exposure. However, for several effects such as DNA damage, vitamin D photosynthesis or the probability of developing skin cancer, UV radiant energy is important and with that the size of exposed skin area. There is also a complex interaction between body shape and behavior like sun exposure habits, so that careful analysis is necessary when estimating health effects from UV exposure. In this paper, knowledge on body shape and methods of calculating the total body surface area (BSA) are summarized. BSA depends mainly on the height and weight of a person as well as on gender, ethnicity and body shape. BSA and body shape differ significantly between different populations and both change during life. This paper proposes formulas for BSA that consider height, weight, gender, ethnicity and body shape. As the exposed BSA depends on clothing, finally an approach is presented which aims to calculate the size of body parts released by real garments. In summary, this paper will enable future researchers to quantify the exposed BSA by best matching their study population and consequently investigate risks caused by solar UV exposure.

Age- and sex-specific dermal exposure of polycyclic aromatic hydrocarbons in the general population of a city in south China

This study assessed the dermal exposure of population to polycyclic aromatic hydrocarbons (PAHs) in a South China city. Skin wipe samples of the face, hand, forearm, and shank were collected from 120 volunteers (50% male and 50% female) belonging to different age groups (preschooler, thresholder, middle-aged, and elderly). Concentrations of PAHs in the skin wipe samples varied from 18 to 27000 ng/m² in the order of face > hand > forearm > shank, regardless of age and gender. The PAH concentrations of bare skin locations were significantly higher in females than in males, while no significant differences were observed for clothing-covered skin locations between genders. The PAH concentrations for faces were significantly higher in the elderly compared to the other groups. The PAH composition was distinct between the four age groups. The dermal exposure levels of total PAHs and total BaP equivalent concentration (BaP_eq) varied from 25.6 to 620 and 0.093-37.4 ng/kg body weight/d, respectively. The dermal exposure levels of total PAHs were significantly higher in females than in males in all age groups except for the middle-aged group. The hand-mouth exposure doses were significantly higher in the preschoolers than in the other age groups. The values of the carcinogenic risk caused by dermal PAH exposure were between 3.5 × 10^-6 and 1.4 × 10^-3 with 29% of the population (35/120) having risk values exceeding significant levels (1 × 10^-4). The thresholder group exhibited the highest risk for PAH dermal exposure among all groups of the population. This study provides a comprehensive evaluation of the age- and gender-related risk of PAH through dermal exposure.

Cardiopulmonary parameters and organ blood flows for workers expressed in terms of VO2 for use in physiologically based toxicokinetic modeling

Minute ventilation rates (VE), alveolar ventilation rates (VA), cardiac outputs (Q), liver blood flow (LBF) and kidneys blood flows (KBF) for physiologically based toxicokinetic modeling and occupational health risk assessment in active workers have apparently not been determined. Minute energy expenditure rates (E) and oxygen consumption rates (VO₂) in workers during exertions and their aggregate daytime activities are obtained by using open-circuit wearable devices for indirect calorimetry measurements and the doubly labeled water method respectively. Hundreds of E (in kcal/min) and VO₂ (in L of O₂/min) were previously reported for workers. The oxygen uptake factors of 0.2059 ± 0.0019 and 0.2057 ± 0.0018 L of O₂/kcal during postprandial and fasting phases respectively enabled conversion of E into VO₂. Equations determined in this study based upon more than 25 000 published measurements enable the calculation of 15 parameters in the same worker only by using the VO₂ reflecting workload. These parameters, notably VE, VA, VE/VO₂ VA/Q, Q, LBF and KBF were found to be interrelated. Altering one of these changes the order of magnitude of the others. Q, LBF and KBF decrease when supine adults at rest switch to an upright position. This effect of gravity diminished when VO₂ increased. The fall in LBF and KBF during exertion might enhance muscle blood flow as reported previously. Taken together these equations and data may improve the accuracy of physiologically based toxicokinetic modeling as well as occupational health assessment studies in active workers exposed to xenobiotics.List of main abbreviations: AVOD: arterioveinous oxygen content difference.BMI: body mass index (in kg/m²).BSA: body surface area (in m²).BTPS: body temperature and saturated with water vapor.Bw: body weight (in kg).E: minute energy expenditure rate (in kcal/min).F_GE: organ blood flow factor for the gravitational effect on blood circulation.H: oxygen uptake factor, volume of oxygen (at STPD) consumed to produce 1 kcal of energy expended.KBF: kidneys blood flow (in ml/min).LBF: liver blood flow (in ml/min).P_BF: liver or kidneys blood flows expressed in terms of percentages (in %) of Q_{sup C} values: namely P_BF = (LBF or KBF/Q_{sup C}) x 100.Q: cardiac output (in L/min or ml/min).Q_{sup C:} cardiac output for the cohort of males or females in supination (in ml/min).STPD: standard temperature and pressure, dry air.sup: values measured when adults are in the supine position.up: values measured when adults are in the upright position.VDphys: physiological dead space at BTPS (in L).VT: tidal volume at BTPS (in L).VA: alveolar ventilation rate at BTPS (in L/min).VA/Q: ventilation-perfusion ratio (unitless).VE: minute ventilation rate at BTPS (in L/min).VO₂: oxygen consumption rate (i.e. the oxygen uptake) at STPD (in L/min).VQ: ventilatory equivalent for VO₂ (VE at BTPS /VO₂ at STPD).

Body mapping chart for estimation of percentage of body surface area in mesocephalic dogs

OBJECTIVE

To create a chart for estimating body surface area (BSA) for use in canine burn victims, similar to the human Rule of Nines.

DESIGN

Prospective study, from 2016 to 2017.

SETTING

University teaching hospital.

ANIMALS

Nine adult, medium-sized, mesocephalic dogs (5 females, 4 males).

INTERVENTIONS

Sedated dogs and fresh cadavers underwent full-body computed tomography (CT) scans. A 3-dimensional technique was used to calculate the surface area of specific body parts, as well as the surface area of the whole body. With the obtained measurements, a BSA chart was created.

MEASUREMENTS AND MAIN RESULTS

Estimates for percent of total BSA obtained with CT images were as follows: head and abdomen 14%, respectively, neck and each of the thoracic limbs 9%, thorax 18%, pelvic limbs 11% each, and pelvis including the tail 5%. The most considerable differences between dogs and people in respect to the Rule of Nines chart were noticed in the head, the pelvic limbs, as well as in the groin region in people as compared with the pelvic/tail area in dogs. The surface areas of the front legs and thorax were the only body parts that corresponded with that of human body surfaces.

CONCLUSIONS

A chart for estimating canine body surface was created. Given the diversity of dog breeds, sizes, and body conformation, our results cannot be generalized to all dogs. Studies of more diverse populations are warranted.

Combination of Thigh Circumference and Indices of Central Obesity Helps Predict Incident Chronic Kidney Disease: A 14-Year Prospective Cohort Study Using a Three-Dimensional Body Laser Scanner

OBJECTIVE

Obesity, high body mass index, and visceral fat accumulation are associated with renal diseases. However, the association between body measurements and chronic kidney disease (CKD) is still unclear.

METHODS

A cohort of 7,825 participants scheduled for follow-up of CKD was recruited from 2000 to 2008 in Taiwan. A questionnaire was developed to collect the basic demographics, lifestyle variables, personal disease history, and family disease history of the participants. A 3-dimensional body surface scanning system was used to take their body measurements. The participants underwent an average follow-up of 14.3 years for evaluation of the incidence of CKD. A multiple Cox regression model was built.

RESULTS

Three body measurements, namely chest width (hazard ratio [HR] 1.059, 95% confidence interval [CI] 1.011-1.110), waist circumference (HR 1.017, 95% CI 1.006-1.029), and thigh circumference (HR 0.941, 95% CI 0.922-0.961), were significantly associated with CKD. Two combinations of body measurements, namely the waist-to-thigh ratio and chest-to-thigh ratio, were derived to predict the occurrence of CKD. Participants with the highest quartile of waist-to-thigh ratio and chest-to-thigh ratio had a 2.175-fold and 2.182-fold risk of developing CKD, respectively.

CONCLUSIONS

This study suggests that along with central obesity, body limb measurements can be used as an indicator to predict the occurrence of CKD. The effects of limb measurements on CKD could help provide an innovative perspective regarding the intervention to be developed for the treatment of CKD and a preventive medicine for high-risk individuals. The association of thigh circumference with CKD warrants further investigation.

The evolution of long-term pediatric ventricular assistance devices: a critical review

Introduction: The gap between the number of heart failure patients and the number of potential heart donors has never been larger than today, especially among the pediatric population. The use of mechanical circulatory support is seen as a potential alternative for clinicians to treat more patients. This treatment has proven its efficiency on short-term use. However, in order to replace heart transplant, the techniques should be used over longer periods of time.Areas covered: This review aims at furnishing an engineering vision of the evolution of ventricular assistance devices used in pediatrics. A critical analysis of the clinical complications related to devices generation is made to give an overview of the design improvements made since their inception.Expert opinion: The long-term use of a foreign device in the body is not without consequences, especially among fragile pediatric patients. Moreover, the size of their body parts increases the technical difficulties of such procedure. The balance between the living cells of the body is disturbed by the devices, mostly by the shear stress generated. To provide a safe mechanical circulatory support for long-term use, the devices should be more hemocompatible, preserving blood cells, adapted to the patient's systemic grid and miniaturized for pediatric use.

Cardiopulmonary values and organ blood flows before and during heat stress: data in nine subjects at rest in the upright position

Physiological changes associated with thermoregulation can influence the kinetics of chemicals in the human body, such as alveolar ventilation (VA) and redistribution of blood flow to organs. In this study, the influence of heat stress on various physiological parameters was evaluated in nine male volunteers during sessions of exposure to wet blub globe temperatures (WBGT) of 21, 25 and 30°C for four hours. Skin and core temperatures and more than twenty cardiopulmonary parameters were measured. Liver, kidneys, brain, skin and muscles blood flows were also determined based on published measurements. Results show that most subjects (8 out of 9) have been affected by the inhalation of hot and dry air at the WBGT of 30°C. High respiratory rates, superficial tidal volumes and low VA values were notably observed. The skin blood flow has increased by 2.16-fold, whereas the renal blood flow and liver blood flow have decreased by about by 11 and 18% respectively. A complete set of key cardiopulmonary parameters in healthy male adults before and during heat stress was generated for use in PBPK modeling. A toxicokinetic studies are ongoing to evaluate the impact of heat stress on the absorption, biotransformation and excretion rates of volatile xenobiotics.

Exercise Thermal Sensation: Physiological Response to Dynamic-Static Steps at Moderate Exercise

The study of exercise thermal sensation is more difficult than that of static thermal sensation in the human body. This work's main purpose was to examine specific changes in human physiological parameters and subjective perceptions during the exercise process, especially around dynamic-static steps, and to assess exercise thermal sensation. Experiments were conducted in a climate chamber. A total of 16 subjects participated in two activities of different intensities on a treadmill, namely at 4.5 km/h and 6 km/h. The experimental procedure was set to static-dynamic-static. Skin temperature (Tsk), oral temperature (Tor), heart rate (HR), heart rate variability (HRV) parameters, and electrodermal activity (EDA) were measured at fixed time points, and thermal sensation values, thermal comfort values, and sweat feeling index were collected. The results showed complex changes in physiological indicators around the dynamic-static steps. Some important physio-logical indicators can be used as valid parameters for exercise thermal sensation models, such as Tsk, Tor, and EDA. This study highlighted that prediction models using average change and rate of change of measurements were better than using the original measurements. Our findings suggest that the exercise thermal sensation prediction models should be constructed according to the dynamic-static state and that psychological factors cannot be ignored.

Intraperitoneal chemotherapy in the treatment of gastric cancer peritoneal metastases: an overview of common therapeutic regimens

Peritoneal metastasis (PM) have an incidence of 10-20% in patients with gastric cancer (GC), and even up to 40% in patients with UICC Stage III GC. Due to the aggressive characteristic of adenocarcinoma of the stomach, GC is the third leading cause of cancer deaths worldwide. For GC with PM, the treatment of choice is according to national and international guidelines systemic chemotherapy, combined with biologic therapy against specific receptor antigen in with overexpression, such as HER-2. Multimodal treatment regimens including intraperitoneal application of chemotherapy and cytoreductive surgery (CRS) have been investigated and established all over the world. Driven by pharmacological studies and thoughts considering the increased benefits of cytotoxic agents used in the abdominal cavity, several drugs and drug combinations are widely used. In order to standardize treatment protocols, it is crucial to differentiate between normothermic and hyperthermic intraperitoneal chemotherapy (NIPEC, HIPEC). The requirements of an ideal cytotoxic drug different obviously dependent on its application method. Because of their high molecular weight and lipophilic structure, taxanes, such as paclitaxel or docetaxel have a long intraperitoneal retention time and are commonly used in NIPEC, while platin derivates, such as carboplatin or oxaliplatin are known for their synergistic effect to heat and are chosen in HIPEC. This review aims to explore and summarize different intraperitoneal treatment regimens strictly evaluated by supporting evidence in an effort to consolidate many regimens to a few evidence-based treatment protocols that deserve further investigation and distribution. This analysis included all studies focusing on intraperitoneal chemotherapy: Phase II, Phase III trials and non-randomized retrospective trials of larger cohorts of patients with GC and established PM or risk of PM. Interestingly, the protocols for NIPEC are quite uniform, with less variation between the therapeutic components in contrast to the different HIPEC protocols. This difference might be explained by the divergent evolution of NIPEC and HIPEC, as the former exclusively originated in Japan, while HIPEC experienced a more multicentric evolution and distribution in the United States, Asia, Europe, and worldwide utilization today.

Technical and Medical Aspects of Burn Size Assessment and Documentation

In burn medicine, the percentage of the burned body surface area (TBSA-B) to the total body surface area (TBSA) is a crucial parameter to ensure adequate treatment and therapy. Inaccurate estimations of the burn extent can lead to wrong medical decisions resulting in considerable consequences for patients. These include, for instance, over-resuscitation, complications due to fluid aggregation from burn edema, or non-optimal distribution of patients. Due to the frequent inaccurate TBSA-B estimation in practice, objective methods allowing for precise assessments are required. Over time, various methods have been established whose development has been influenced by contemporary technical standards. This article provides an overview of the history of burn size estimation and describes existing methods with a critical view of their benefits and limitations. Traditional methods that are still of great practical relevance were developed from the middle of the 20th century. These include the "Lund Browder Chart", the "Rule of Nines", and the "Rule of Palms". These methods have in common that they assume specific values for different body parts' surface as a proportion of the TBSA. Due to the missing consideration of differences regarding sex, age, weight, height, and body shape, these methods have practical limitations. Due to intensive medical research, it has been possible to develop three-dimensional computer-based systems that consider patients' body characteristics and allow a very realistic burn size assessment. To ensure high-quality burn treatment, comprehensive documentation of the treatment process, and wound healing is essential. Although traditional paper-based documentation is still used in practice, it no longer meets modern requirements. Instead, adequate documentation is ensured by electronic documentation systems. An illustrative software already being used worldwide is "BurnCase 3D". It allows for an accurate burn size assessment and a complete medical documentation.

Bioaccumulation of potentially toxic elements in three mangrove species and human health risk due to their ethnobotanical uses

The aim of this study was to assess probabilistic human health risk due to ethnobotanical usage of Avicennia officinalis, Porteresia coarctata and Acanthus ilicifolius. The study was conducted at the tannery outfall near Sundarban (Ramsar wetland, India) mangrove ecosystem  affected by potentially toxic elements (Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn). Total metal concentrations (mg kg-1) were considerably higher in the polluted rhizosphere namely, Cd (1.05-1.97), Cu (36.3-38.6), Cr (144-184), Hg (0.04-0.19), Mn (163-184), Ni (37.7-46.4), Pb (20-36.6), and Zn (97-104). Ecological risk index indicated low to moderate ecological risk in this site, whereas the ecological risk factor showed high potential ecological risk due to Cd pollution. BCR Sequential extraction of metals showed more exchangeable fraction of Cd (47-55%), Cr (9-13%), Hg (11-13%), and Pb (11-15%), at the polluted site. Mercury, though present in trace amount in sediment, showed the highest bioaccumulation in all the three plants. Among the toxic trio, Hg showed the highest bioaccumulation in A. officinalis, Cd in P. coarctata but Pb has the lowest bioaccumulation potential in all the three species. Occasional fruit consumption of A. officinalis and dermal application of leaf, bark of A. officinalis (antimicrobial), A. ilicifolius (anti-inflammatory, pain reliever when applied on wounds) indicated negligible human health risk. However, long-term consumption of P. coarctata (wild rice variety) seeds posed health risk (THQ>1) both in adults and children age groups. This study concludes that nature of ethnobotanical use and metal contamination levels of the mangrove rhizosphere can impact human health. The transfer process of potentially toxic elements from rhizosphere to plants to human body should be considered while planing pollution mitigation measures. Graphical Abstract.

Body surface area capping may not improve cytotoxic drugs tolerance

Capping body surface area (BSA) at 2 m² is a routine clinical practice. It aims at reducing toxicities in over 2 m² BSA patients. 455,502 computerized chemotherapy prescriptions made between 2011 and 2017 were taken from BPC software. Chemotherapy computerized order entry is created by a senior physician prescribers before patient consultation. Only prescriptions with dose calculation involving BSA were selected. 51,179 chemotherapy prescriptions were analyzed; corresponding to 7206 patients who received intravenous chemotherapy. The number of chemotherapy prescriptions in over 2 m² BSA patients was nearly the same in the hematology as in the oncology departments. But, 79.1% of prescriptions were capped at 2 m² in the oncology department contrary to 21.9% in the hematology department. Practices analysis showed more dose limitation in palliative situations in both departments. Unexpectedly, 6.53% of capped prescriptions were performed in patients with normal BMI. The patients who received capped doses of chemotherapy had neither fewer dose reductions due to toxicity nor deterioration of their general condition. Capping did not induce fewer dose reductions in patients with BSA greater than 2 m². Prospective studies in this population are needed to standardize chemotherapy administration in population with BSA > 2 m².

Does the estimation of burn extent at admission differ from the assessment at discharge?

INTRODUCTION

Estimation of total body surface area (TBSA) burnt and burn depth are among the most central parts of acute burn assessment/treatment as they determine the level and type of care needed. Traditional methods for determining burn extent on admission often lead to inaccurate estimations, especially in paediatric or overweight patients.

AIM

To compare %TBSA at admission with validated %TBSA at discharge in different patient populations to investigate if significant over- or underestimation occurs.

METHOD

This retrospective observational study is based on a patient registry of all the patients (n = 863) treated at the Uppsala University Hospital's Burn Centre between 2010 and 2018. The patients were divided into subgroups based on age, gender, body mass index (BMI) and validated burn extent. The %TBSA estimated at admission was compared to the validated %TBSA in all groups separately.

RESULTS

As has been published before, we also found that the %TBSA in paediatric patients was more often overestimated as were the smaller injuries, whereas larger injuries were often underestimated. BMI did not clearly affect the estimations and there was no clear difference between the genders in estimated %TBSA.

CONCLUSION

Inaccurate estimations of %TBSA are common, particularly for paediatric patients and small or large injuries. We recommend a careful accurate approach when calculating %TBSA in the paediatric population to avoid over- and under-resuscitation. Increased education and training are recommended to improve accurate estimation in the future.

LAY SUMMARY

The correct estimation of both extent and depth of burn is very important. This assessment guides the lever of care needed, the necessary amount of fluid resuscitation, the predicted outcome and more. It has been proven notably difficult to correct assess, especially the extent of a burn. Despite different tools as the "Rule of Nine" (body area divided into multiples of 9% body surfaces), the "Rule of Palm" (Patient's palm, fingers included, approximates 1% of body surfaces), the Lund & Browder chart (detailed, age-specific body areas) and different more technical solutions. Often inaccurate estimations are done which thus affect the treatment. This depth and extent estimation is usually performed when the patient is admitted. However, it is known that burns change appearance during the first few days of care. In our Burn Center we have also performed this estimation when the patient is discharged. At this point it is known the true extent and depth of the initial burn. In this retrospective observational study, we compared the burn extent estimated on admission with the one on discharge to investigate whether the initial assessment is accurate. This study highlights the issue of frequent inaccurate burn extent estimations, especially in subgroups as overweight patient or pediatric patients.

Establishment of normal reference ranges for total and separate glomerular filtration rates in living kidney donors by Gates' method after renal depth measured using single-photon emission computed tomography/computed tomography

Background

The underestimation of renal depth by Tønnesen formula in Gates' method, which has been confirmed by many scholars, leads to the underestimation of both separate glomerular filtration rate (gSGFR) and total glomerular filtration rate (gTGFR). This study aimed to establish the normal reference ranges of renal depth-calibrated gTGFR and gSGFR in Chinese healthy adults, and to analyze the influencing factors.

Methods

Renal depth was measured by CT scan followed by technetium 99m-diethylene triamine pentaacetic acid (^99mTc-DTPA) renal dynamic imaging by single-photon emission computed tomography/computed tomography (SPECT/CT) in 329 living kidney donors. The renal depth-calibrated gTGFR and gSGFR were calculated by Gates' method with renal depth measured by CT instead of being calculated by the Tønnesen formula. A general linear model based on age, gender, body height, body weight, and BMI was used to analyze factors influencing gSGFR (L), gSGFR (R) and gTGFR.

Results

The average gSGFR (L), gSGFR (R), and gTGFR for patients aged 23-64 years old were 49.3±10.1, 49.9±10.4, and 99.1±18.7 mL/min/1.73 m², respectively. The gSGFR (L), gSGFR (R) and gTGFR for patients aged 41-50 years old were 26.9-69.3, 27.7-68.8, and 57.5-135.3 mL/min/1.73 m², respectively, and those for patients aged 51-60 years old were 31.0-61.5, 29.5-63.3, and 64.6-120.7 mL/min/1.73 m², respectively. gSGFR (L), gSGFR (R) and gTGFR had statistical significance with body height and age (P<0.05); however, there was no significant difference with gender, body weight, and BMI (P>0.05). For each 1 year increase in age, the gSGFR (L), gSGFR (R), and gTGFR decreased by 0.17, 0.28, and 0.44 mL/min/1.73 m², respectively, while for every 1 cm increase in body height, the gSGFR (L), gSGFR (R), and gTGFR decreased by 0.37, 0.36, and 0.74 mL/min/1.73 m², respectively.

Conclusions

Normal reference ranges for renal depth-calibrated gSGFR (L), gSGFR (R), and gTGFR were established in healthy Chinese adults aged 23-64 years, and gSGFR (L), gSGFR (R), and gTGFR decreased with age and body height.

Estimation of body surface area in neonates, infants, and children using body weight alone

Background

The aim of this study was to use Body Surface Area (BSA) data calculated with the Mosteller equation to test potential new equations that estimate BSA using Body Weight (BW) alone in children aged 0–18 years.

Mosteller’s equation, the golden standard at our hospital, was used to calculate the BSA in infants and children aged 0–18 years using BW and height data from 27,440 hospital visits by 20,635 patients over one year.

Methods

The best fit of three nonlinear regression equations (third-order polynomial, Meeh-type, and modified Boyd self-adjusting-type) to a plot of the calculated Mosteller BSA values versus BW was then investigated. The correlation between the BSA values estimated by these equations and the Mosteller BSA values was established by the Spearman rank correlation test. Bias and precision were evaluated as outlined by Sheiner and Beal. Measured and estimated BSA values were compared using the Eksborg plot.

Results

The estimated BSA values from all three equations and the BSA values from the Mosteller equation were closely correlated (P < .0001). The third-order polynomial and Meeh-type equations overestimated BSA by 0.13% and 0.40%, respectively, while the Boyd self-adjusted-type equation underestimated BSA by 0.060%. For the entire pediatric population, the best fit was obtained with the Meeh-type equation: 99.2% of the Meeh/Mosteller BSA ratios were within the range of 0.9–1.1 when compared with 98.3% and 97.2% for the polynomial and Boyd-type equations, respectively.

Conclusion

A single Meeh-type equation can be used to predict the results of Mosteller equation when H is not available with high precision and accuracy in children aged 0–18 years, including term neonates. We now plan to include the results of this study in CPOE systems in Sweden to improve drug dosage in all children.

Artifact-free CT images for electron beam therapy using a patient-specific non metallic shield

Patient's CT images taken with metallic shields for radiotherapy suffer from artifacts. Furthermore, the treatment planning system (TPS) has a limitation on accurate dose calculations for high density materials. In this study, a Monte Carlo (MC)-based method was developed to accurately evaluate the dosimetric effect of the metallic shield. Two patients with a commercial tungsten shield of lens and two patients with a custom-made lead shield of lip were chosen to produce their non-metallic dummy shields using 3D scanner and printer. With these dummy shields, we generated artifact-free CT images. The maximum CT number allowed in TPS was assigned to metallic shields. MC simulations with real material information were carried out. In addition, clinically relevant dose-volumetric parameters were calculated for the comparison between MC and TPS. Relative dosimetry was performed using radiochromic films. The dose reductions below metallic structures were shown on MC dose distributions, but not evident on TPS dose distributions. The differences in dose-volumetric parameters of PTV between TPS and MC for eye shield cases were not clearly shown. However, the mean dose of lens from TPS and MC was different. The MC results were in superior agreement with measured data in relative dosimetry. The lens dose could be overestimated by TPS. The differences in dose-volumetric parameters of PTV between TPS and MC were generally larger in lip cases than in eye cases. The developed method is useful in predicting the realistic dose distributions around the organs blocked by the metallic shields.

Parametric human modelling to determine body surface area covered by sun-protective clothing

Solar ultraviolet radiation (UVR) is the main environmental risk-factor for cancer of the skin. Sun-protective clothing provides a physical barrier that reduces the UVR dose reaching the skin and European and Australian standards for sun-protective clothing set minimum clothing coverage requirements. Body Surface Area Coverage by clothing (BSAC) is calculated by means of indirect or direct methods, which are laborious and do not support computer-based apparel design. To support the sun-safe specification and design of garments, parametric digital human models and protective clothing mesh covering the minimum Body Surface Area specified in AS/NZS 4399:2017, were created making use of MakeHuman v1.1.1 and Blender software. The Whole Body Surface Area (WBSA) and the BSAC were calculated employing code developed in Blender. Thus, different groups of subjects were analysed to explore BSAC. The method assists in the evaluation of exposed body areas in a wider spectrum of different occupations. Practitioner summary: Sun-protective clothing provides a physical barrier that reduces the UVR dose reaching the skin's surface. Body Surface Area Coverage (BSAC) by clothing is an important determinant of the sun protective capabilities of a garment. In this study, BSAC is calculated using parametric digital human modelling. Abbreviation: UVR: (Solar) ultraviolet radiation; DHM: digital human modeling; BSA: body surface area; BSAC: body surface area coverage (by clothing); BSANC: body surface area not covered (by clothing); WBSA: whole body surface area; BCC: basal cell carcinoma; SCC: squamous cell carcinoma; UPF: ultraviolet protection factor; GPF: garment protection factor.

Obesity and chemotherapy administration: between empiric and mathematic method review

Introduction: Obesity is a major risk factor for chronic disease and cancer development. Therapeutic management of obese patients with cancer is a real challenge for physician because of the alteration of antineoplastic pharmacokinetics parameters in this population. In routine clinical practices, chemotherapy doses in obese patients are arbitrarily capped or adjusted to an ideal weight to minimize excessive toxicities. Material and methods: The main goal of this review is to describe the current state of knowledge concerning the correlation between the adjustment of BSA (capping or ideal weight) and the rates of global toxicities and survival outcomes in obese patients under chemotherapy in different types of cancer. We searched in the Medline database (via PubMed) in order to identify all publications of literature reviews whose subject chemotherapy dosing in obese population. Results: Only a single study was pointing toward increased of global toxicities of full weight dosing. Furthermore, some studies suggests that the practice of limiting doses in overweight and obese patients may negatively influence the quality of care and outcomes in a constantly increasing population. Conclusion: This review highlights the lack of prospective studies focusing on chemotherapy methods of administration in obese patients. At this time, there is no prospective study comparing capping and full weight dose chemotherapy administration in obese patient population.

A comparison of manual anthropometric measurements with Kinect-based scanned measurements in terms of precision and reliability

BACKGROUND

Collecting anthropometric data for real-life applications demands a high degree of precision and reliability. It is important to test new equipment that will be used for data collectionOBJECTIVE:Compare two anthropometric data gathering techniques - manual methods and a Kinect-based 3D body scanner - to understand which of them gives more precise and reliable results.

METHODS

The data was collected using a measuring tape and a Kinect-based 3D body scanner. It was evaluated in terms of precision by considering the regular and relative Technical Error of Measurement and in terms of reliability by using the Intraclass Correlation Coefficient, Reliability Coefficient, Standard Error of Measurement and Coefficient of Variation.

RESULTS

The results obtained showed that both methods presented better results for reliability than for precision. Both methods showed relatively good results for these two variables, however, manual methods had better results for some body measurements.

CONCLUSION

Despite being considered sufficiently precise and reliable for certain applications (e.g. apparel industry), the 3D scanner tested showed, for almost every anthropometric measurement, a different result than the manual technique. Many companies design their products based on data obtained from 3D scanners, hence, understanding the precision and reliability of the equipment used is essential to obtain feasible results.

Predicting Type 2 Diabetes Mellitus Occurrence Using Three-Dimensional Anthropometric Body Surface Scanning Measurements: A Prospective Cohort Study

BACKGROUND

An accurate and comprehensive anthropometric measure for predicting type 2 diabetes mellitus (T2DM) has not yet been depicted.

METHODS

A total of 8450 nondiabetic participants were recruited during 2000-2010 in Taiwan. The cohort was followed up to the end of 2013, over an average of 8.87 years. At recruitment, participants completed a questionnaire related to basic demographics, lifestyle variables, personal disease history, and family disease history. 3D body surface scanning was used to obtain 35 anatomical measurements. A Cox proportional hazard model was used to conduct multivariable analyses.

RESULTS

A total of 2068 T2DM cases at an incidence rate of 27.59 × 10-3 (year-1) were identified during the follow-up period. Multivariable-adjusted hazard ratios (HRs) demonstrated that neck circumference (NC) (HR = 1.048; 95% CI = 1.033-1.064), waist width (WW) (HR = 1.061; 95% CI = 1.040-1.081), and left thigh circumference (TC) (HR = 0.984; 95% CI = 0.972-0.995) were significant predictors of the occurrence of T2DM. While dividing body measurement into median high/low groups, an increased risk of T2DM was observed among participants with a larger NC and smaller TC (HR = 1.375; 95% CI = 1.180-1.601) and a larger WW and smaller TC (HR = 1.278; 95% CI = 1.085-1.505) relative to other participants.

CONCLUSIONS

This study suggests that as well as using traditional waist and TC measurements, NC can be used as an indicator to provide an early prediction of developing T2DM, while providing clues for future mechanistic investigations of T2DM.

Application of physiologically based pharmacokinetic modeling to the prediction of drug-drug and drug-disease interactions for rivaroxaban

PURPOSE

Rivaroxaban is a direct oral anticoagulant with a large inter-individual variability. The present study is to develop a physiologically based pharmacokinetic (PBPK) model to predict several scenarios in clinical practice.

METHODS

A whole-body PBPK model for rivaroxaban, which is metabolized by the cytochrome P450 (CYP) 3A4/5, 2J2 pathways and excreted via kidneys, was developed to predict the pharmacokinetics at different doses in healthy subjects and patients with hepatic or renal dysfunction. Hepatic clearance and drug-drug interactions (DDI) were estimated by in vitro in vivo extrapolation (IVIVE) based on parameters obtained from in vitro experiments. To validate the model, observed concentrations were compared with predicted concentrations, and the impact of special scenarios was investigated.

RESULTS

The PBPK model successfully predicted the pharmacokinetics for healthy subjects and patients as well as DDIs. Sensitivity analysis shows that age, renal, and hepatic clearance are important factors affecting rivaroxaban pharmacokinetics. The predicted fold increase of rivaroxaban AUC values when combined administered with the inhibitors such as ketoconazole, ritonavir, and clarithromycin were 2.3, 2.2, and 1.3, respectively. When DDIs and hepatic dysfunction coexist, the fold increase of rivaroxaban exposure would increase significantly compared with one factor alone.

CONCLUSIONS

Our study using PBPK modeling provided a reasonable approach to evaluate exposure levels in special patients under special scenarios. Although further clinical study or real-life experience would certainly merit the current work, the modeling work so far would at least suggest caution of using rivaroxaban in complicated clinical settings.

Computer tomography-based body surface area evaluation for drug dosage: Quantitative radiology versus anthropomorphic evaluation

OBJECTIVE

The measure of body surface area (BSA) is a standard for planning optimal dosing in oncology. This index is derived from a model having questionable performances. In this study, we proposed measurement of BSA from whole body CT images (iBSA). We tested the reliability of iBSA assessments and simulated the impact of our approach on patient chemotherapy dosage planning.

METHODS

We first evaluated accuracy and precision of iBSA in measuring 14 phantom and 11 CT test-retest images.Secondly, we retrospectively analyzed 26 whole body PET-CT scans to evaluate inter-method variability between iBSA and the most used anthropomorphic models, notably the "Du Bois and Du Bois" model. Finally, we simulated the impact on chemotherapy dose planning of capecitabine based on iBSA.

RESULTS

Precision and accuracy of iBSA measurement featured a standard deviation of 1.11% and a mean error of 1.53%. Inter-method variability between iBSA and "Du Bois and Du Bois" assessment featured a standard deviation of 4.11% leading to a reclassification rate of capecitabine of 32.5%.

CONCLUSIONS

iBSA could help the oncologist in standardizing assessments for chemotherapy planning. iBSA could also be relevant for applications such as comprehensive body composition and provide a sensitive measurement for changes related to nutritional intake or other metabolism.

Technical Report on the Modification of 3-Dimensional Non-contact Human Body Laser Scanner for the Measurement of Anthropometric Dimensions: Verification of its Accuracy and Precision

Introduction: Three-dimensional (3D) scanners are widely used in medicine. One of the applications of 3D scanners is the acquisition of anthropometric dimensions for ergonomics and the creation of an anthropometry data bank. The aim of this study was to evaluate the precision and accuracy of a modified 3D scanner fabricated in this study. Methods: In this work, a 3D scan of the human body was obtained using DAVID Laser Scanner software and its calibration background, a linear low-power laser, and one advanced webcam. After the 3D scans were imported to the Geomagic software, 10 anthropometric dimensions of 10 subjects were obtained. The measurements of the 3D scanner were compared to the measurements of the same dimensions by a direct anthropometric method. The precision and accuracy of the measurements of the 3D scanner were then evaluated. The obtained data were analyzed using an independent sample t test with the SPSS software. Results: The minimum and maximum measurement differences from three consecutive scans by the 3D scanner were 0.03 mm and 18 mm, respectively. The differences between the measurements by the direct anthropometry method and the 3D scanner were not statistically significant. Therefore, the accuracy of the 3D scanner is acceptable. Conclusion: Future studies will need to focus on the improvement of the scanning speed and the quality of the scanned image.

A Framework for Analyzing the Whole Body Surface Area from a Single View

We present a virtual reality (VR) framework for the analysis of whole human body surface area. Usual methods for determining the whole body surface area (WBSA) are based on well known formulae, characterized by large errors when the subject is obese, or belongs to certain subgroups. For these situations, we believe that a computer vision approach can overcome these problems and provide a better estimate of this important body indicator. Unfortunately, using machine learning techniques to design a computer vision system able to provide a new body indicator that goes beyond the use of only body weight and height, entails a long and expensive data acquisition process. A more viable solution is to use a dataset composed of virtual subjects. Generating a virtual dataset allowed us to build a population with different characteristics (obese, underweight, age, gender). However, synthetic data might differ from a real scenario, typical of the physician's clinic. For this reason we develop a new virtual environment to facilitate the analysis of human subjects in 3D. This framework can simulate the acquisition process of a real camera, making it easy to analyze and to create training data for machine learning algorithms. With this virtual environment, we can easily simulate the real setup of a clinic, where a subject is standing in front of a camera, or may assume a different pose with respect to the camera. We use this newly designated environment to analyze the whole body surface area (WBSA). In particular, we show that we can obtain accurate WBSA estimations with just one view, virtually enabling the possibility to use inexpensive depth sensors (e.g., the Kinect) for large scale quantification of the WBSA from a single view 3D map.

Seasonal Epidemiology of Serum 25-Hydroxyvitamin D Concentrations among Healthy Adults Living in Rural and Urban Areas in Mongolia

Many factors put Mongolians at risk of vitamin D deficiency. Despite low levels observed in Mongolian children and pregnant women, there are few data published on the vitamin D status of non-pregnant adults. Between summer 2011 and winter 2013, paired summer and winter blood samples were collected from 320 healthy men and women (20–58 years) living in eight Mongolian provinces. Mean serum 25(OH)D concentrations were 22.5 ng/mL (95% CI: 14.5, 32.5) in summer and 7.7 ng/mL (95% CI: 4.6, 10.8) in winter, with a distribution (<10/10–20/20–30/≥30 ng/mL) of 3.1%/39.3%/39.6%/17.9% in summer and 80.1%/19.5%/0.3%/0.0% in winter. Residents of the capital, Ulaanbaatar, had lower levels in both seasons than any other region, whereas residents of the Gobi desert had the highest. In summer, indoor workers had significantly lower levels than outdoor workers (−2.3 ng/mL; 95% CI: −4.1, −5.7) while levels in males exceeded those in females (4.0 ng/mL; 95% CI: 2.3, 5.7). Effects of region, occupation, and sex were also significant in multivariable regression. In conclusion, Mongolian adults had extremely low serum 25(OH)D, particularly in winter, when 80.1% had concentrations below 10 ng/mL. These results indicate a need for effective vitamin D interventions for the Mongolian adult population, particularly among women and residents of Ulaanbaatar.

Regression equations of Z score and echocardiographic nomograms for coronary sinus in healthy children

As the number of implanted biventricular pacemakers increases, the coronary sinus (CS) has evoked much interest amongst cardiologists. A dilated CS could prompt the existence of many diseases. The normal CS diameter is uncertain, especially in children. A total of 446 Chinese healthy children were prospectively enrolled in this study. The superior and inferior diameter of the CS was measured from the CS ostium 1 cm from the end of ventricular systole in the modified apical 4-chamber view. Seven models were tested to determine the relationships between parameters of body size and CS diameter. Heteroscedasticity was tested by the White and Breusch-Pagan tests. A multiple linear regression model should be gender as a covariate along with BSA_Stevenson, in order to evaluate the influence of gender on the measurements. The formula of Stevenson was best-fit. The predicted values and Z-score boundaries for measurement of the CS diameter were calculated. Bland-Altman plot regression showed that the 95 % limits of agreement for inter- and intra-observer measurements were not significantly different. We report new, reliable echocardiographic Z scores for the CS diameter derived from a large population of healthy Chinese children. The Z scores can be used in echocardiographic examinations.

The Mystery of the Z-Score

Reliable methods for measuring the thoracic aorta are critical for determining treatment strategies in aneurysmal disease. Z-scores are a pragmatic alternative to raw diameter sizes commonly used in adult medicine. They are particularly valuable in the pediatric population, who undergo rapid changes in physical development. The advantage of the Z-score is its inclusion of body surface area (BSA) in determining whether an aorta is within normal size limits. Therefore, Z-scores allow us to determine whether true pathology exists, which can be challenging in growing children. In addition, Z-scores allow for thoughtful interpretation of aortic size in different genders, ethnicities, and geographical regions. Despite the advantages of using Z-scores, there are limitations. These include intra- and inter-observer bias, measurement error, and variations between alternative Z-score nomograms and BSA equations. Furthermore, it is unclear how Z-scores change in the normal population over time, which is essential when interpreting serial values. Guidelines for measuring aortic parameters have been developed by the American Society of Echocardiography Pediatric and Congenital Heart Disease Council, which may reduce measurement bias when calculating Z-scores for the aortic root. In addition, web-based Z-score calculators have been developed to aid in efficient Z-score calculations. Despite these advances, clinicians must be mindful of the limitations of Z-scores, especially when used to demonstrate beneficial treatment effect. This review looks to unravel the mystery of the Z-score, with a focus on the thoracic aorta. Here, we will discuss how Z-scores are calculated and the limitations of their use.

Body surface area formulae: an alarming ambiguity

Body surface area (BSA) plays a key role in several medical fields, including cancer chemotherapy, transplantology, burn treatment and toxicology. BSA is often a major factor in the determination of the course of treatment and drug dosage. A series of formulae to simplify the process have been developed. Because easy-to-identify, yet general, body coefficient results of those formulae vary considerably, the question arises as to whether the choice of a particular formula is valid and safe for patients. Here we show that discrepancies between most of the known BSA formulae can reach 0.5 m² for the standard adult physique. Although many previous studies have demonstrated that certain BSA formulae provide an almost exact fit with the patients examined, all of these studies have been performed on a limited and isolated group of people. Our analysis presents a broader perspective, considering 25 BSA formulae. The analysis revealed that the choice of a particular formula is a difficult task. Differences among calculations made by the formulae are so great that, in certain cases, they may considerably affect patients’ mortality, especially for people with an abnormal physique or for children.

Annual Average Changes in Adult Obesity as a Risk Factor for Papillary Thyroid Cancer: A Large-Scale Case-Control Study

We evaluated the association between weight change in middle-aged adults and papillary thyroid cancer (PTC) based on a large-scale case-control study. Our study included data from 1551 PTC patients (19.3% men and 80.7% women) who underwent thyroidectomy at the 3 general hospitals in Korea and 15,510 individually matched control subjects. The subjects' weight history, epidemiologic information, and tumor characteristics confirmed after thyroidectomy were analyzed. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were determined for the annual average changes in weight and obesity indicators (body mass index (BMI), body surface area, and body fat percentage (BF%) in subjects since the age of 35 years. Subjects with a total weight gain ≥10 kg after age 35 years were more likely to have PTC (men, OR, 5.39, 95% CI, 3.88-7.49; women, OR, 3.36, 95% CI, 2.87-3.93) compared with subjects with a stable weight (loss or gain <5 kg). A marked increase in BMI since age 35 years (annual average change of BMI ≥0.3 kg/m/yr) was related to an elevated PTC risk, and the association was more pronounced for large-sized PTC risks (<1 cm, OR, 2.34, 95% CI, 1.92-2.85; ≥1 cm, OR, 4.00, 95% CI, 2.91-5.49, P heterogeneity = 0.005) compared with low PTC risks. Weight gain and annual increases in obesity indicators in middle-aged adults may increase the risk of developing PTC.

Is palmar surface area a reliable tool to estimate burn surface areas in obese patients?

Estimating TBSA burned is critical to the initial management and fluid resuscitation of patients who have sustained burn injuries. TBSA of scattered burn injuries are frequently estimated using the patient's percentage palmar surface area (%PSA), which is taught as being 1% of the TBSA. This study investigates the relationship of %PSA to TBSA as the body mass index (BMI) increases. Age, sex, race, weight, height, and PSA was collected from obese and nonobese volunteers. TBSA was calculated using the Mosteller, DuBois-DuBois, Livingston and Scott, and Yu formulas. The %PSA relative to TBSA was calculated in obese and nonobese volunteers. Data from 100 subjects were collected. Fifty subjects had a BMI >30 and 50 had a BMI <30. The average age was 41 years (22-77 years old). There were 68 women and 32 men. The %PSA ranged from 0.49% of TBSA with a BMI of 58.7 to 1.15% of TBSA with a BMI of 22.6. This correlation of %PSA to BMI was statistically significant with all of the formulas. We should not assume that the %PSA is always 1% of TBSA, especially in obese patients.

Evaluation of five formulae for estimating body surface area of nigerian children

BACKGROUND

Physiological functions are often assessed by standardizing for body surface area (BSA) to avoid excessive variation in calculations in pediatric practice.

AIM

To explore the suitability of existing formulae for estimating the BSA of Nigerian children.

SUBJECTS AND METHODS

This cross-sectional study involved healthy children in a Local Government Area, Oyo State, Nigeria. The BSAs of 2745 children were calculated using the formulae by Boyd, Mosteller, Gehan and George, Haycock, and Dubois-DuBois, and the sixth arithmetic mean of these five formulae (mean-BSA) was performed. The outcome of interest was agreement between estimated BSA and mean-BSA for each method. The performance of each BSA estimation method was compared using bias, root mean square error and Bland-Altman plots of agreement.

RESULTS

The study participants comprised of 1229 males and 1246 females with mean (standard deviation) ages of 6.3 (3.0) years and 6.6 (3.1) years respectively (P = 0.01). Reference values for BSA estimates by gender were proposed each age group. Furthermore, BSA estimates from Boyd's and Mosteller's formulae were most similar to the mean-BSA with mathematically perfect correlations. The degree of deviation of BSA estimates from DuBois was largest with a remarkable increase at ages <6 years.

CONCLUSION

Formulae by Boyd and Mosteller are the best BSA estimate for Nigerian children among the existing formulae.

BurnCalc assessment study of computer-aided individual three-dimensional burn area calculation

BACKGROUND

Accurate estimation of a burned area is crucial to decisions about fluid resuscitation, surgical options, nutritional support, and prognosis. Widely used clinical methods to estimate a burn area are two-dimensional. They do not consider age, sex, body mass, physical deformities, or other relevant factors. Computer-aided methods have improved the accuracy of estimating burned areas by including data analysis and reducing subjective differences. Three-dimensional (3D) scanning allows us to determine body dimensions rapidly and reproducibly. We describe an individualized, cost-efficient, portable 3D scanning system, BurnCalc, that can create an individual 3D model and then calculate body surface area (BSA) and the burn area accurately and quickly.

METHODS

The BurnCalc system was validated by verifying the accuracy and stability of BSA calculation. We measured 10 regular objects in experiment 1, using Student's t-test and the intraclass correlation coefficient (ICC) in the analysis. In experiment 2, artificial paper patches of known dimensions were attached to various parts of the body of 40 volunteers. Their sizes were then calculated using BurnCalc. The BurnCalc data were compared to actually measured values to verify accuracy and stability. Total BSAs of these 40 volunteers were also calculated by BurnCalc and compared to those derived from an accepted formula. In experiment 3, four experts using Chinese Rule-of-Nines or Rule-of-Palms methods calculated the percentages of the total BSA in 17 volunteers. Student's t-test and ICC, respectively, were used to compare the results obtained with the BurnCalc technique.

RESULTS

Statistically, in experiment 1, p = 0.834 and ICC = 0.999, demonstrating that there was no difference between the BurnCalc and real measurements. Also, the hypothesis of null difference among measures (experiment 2) was true because p > 0.05 and ICC = 0.999, indicating that calculations of the total BSA and the burn area were more accurate using the BurnCalc technology. The reliability of the BurnCalc program was 99.9%. In experiment 3, only the BurnCalc method exhibited values of p > 0.05 (p = 0.774) and ICC = 0.999.

CONCLUSIONS

BurnCalc technology produced stable, accurate readings, suggesting that BurnCalc could be regarded as a new standard clinical method.

Physiological daily inhalation rates for health risk assessment in overweight/obese children, adults, and elderly

Physiological daily inhalation rates reported in our previous study for normal-weight subjects 2.6-96 years old were compared to inhalation data determined in free-living overweight/obese individuals (n = 661) aged 5-96 years. Inhalation rates were also calculated in normal-weight (n = 408), overweight (n = 225), and obese classes 1, 2, and 3 adults (n = 134) aged 20-96 years. These inhalation values were based on published indirect calorimetry measurements (n = 1,069) and disappearance rates of oral doses of water isotopes (i.e., (2)H2 O and H2 (18)O) monitored by gas isotope ratio mass spectrometry usually in urine samples for an aggregate period of over 16,000 days. Ventilatory equivalents for overweight/obese subjects at rest and during their aggregate daytime activities (28.99 ± 6.03 L to 34.82 ± 8.22 L of air inhaled/L of oxygen consumed; mean ± SD) were determined and used for calculations of inhalation rates. The interindividual variability factor calculated as the ratio of the highest 99th percentile to the lowest 1st percentile of daily inhalation rates is higher for absolute data expressed in m3 /day (26.7) compared to those of data in m3/kg-day (12.2) and m3/m2-day (5.9). Higher absolute rates generally found in overweight/obese individuals compared to their normal-weight counterparts suggest higher intakes of air pollutants (in μg/day) for the former compared to the latter during identical exposure concentrations and conditions. Highest absolute mean (24.57 m3/day) and 99th percentile (55.55 m3 /day) values were found in obese class 2 adults. They inhale on average 8.21 m3 more air per day than normal-weight adults.

Prediction of warfarin maintenance dose in Han Chinese patients using a mechanistic model based on genetic and non-genetic factors

BACKGROUND AND OBJECTIVES

Many attempts have been made to predict the warfarin maintenance dose in patients beginning warfarin therapy using a descriptive model based on multiple linear regression. Here we report the first attempt to develop a comprehensive mechanistic model integrating in vitro-in vivo extrapolation (IVIVE) with a pharmacokinetic-pharmacodynamic model to predict the warfarin maintenance dose in Han Chinese patients. The model incorporates demographic factors [sex, age, body weight (BW)] and the genetic polymorphisms of cytochrome P450 (CYP) 2C9 (CYP2C9) and vitamin K epoxide reductase complex subunit 1 (VKORC1).

METHODS

Information on the various factors, mean warfarin daily dose and International Normalized Ratio (INR) was available for a cohort of 197 Han Chinese patients. Based on in vitro enzyme kinetic parameters for S-warfarin metabolism, demographic data for Han Chinese and some scaling factors, the S-warfarin clearance (CL) was predicted for patients in the cohort with different CYP2C9 genotypes using IVIVE. The plasma concentration of S-warfarin after a single oral dose was simulated using a one-compartment pharmacokinetic model with first-order absorption and a lag time and was combined with a mechanistic coagulation model to simulate the INR response. The warfarin maintenance dose was then predicted based on the demographic data and genotypes of CYP2C9 and VKORC1 for each patient and using the observed steady-state INR (INRss) as a target value. Finally, sensitivity analysis was carried out to determine which factor(s) affect the warfarin maintenance dose most strongly.

RESULTS

The predictive performance of this mechanistic model is not inferior to that of our previous descriptive model. There were significant differences in the mean warfarin daily dose in patients with different CYP2C9 and VKORC1 genotypes. Using IVIVE, the predicted mean CL of S-warfarin for patients with CYP2C9*1/*3 (0.092 l/h, n = 11) was 57 % less than for those with wild-type *1/*1 (0.215 l/h, n = 186). In addition, *1/*1 patients needed about 1 week to reach steady state, whereas *1/*3 patients needed about 2 weeks. In terms of the predicted INRss values, only ten patients had INRss values outside the expected therapeutic range (1.5-2.8). To evaluate our mechanistic model, we predicted the warfarin maintenance dose for 183 patients and explained 42 % of its variation, which is comparable to our previous prediction using a descriptive model based on multiple linear regression. The mean predicted/observed warfarin doses (mg/day) for different combinations of CYP2C9 and VKORC1 genotypes were 1.54/3.75 (n = 1) for *1/*1 and GG, 3.33/3.66 (n = 36) for *1/*1 and AG, 2.31/2.41 (n = 136) for *1/*1 and AA, and 1.56/1.69 (n = 10) for *1/*3 and AA, respectively. Sensitivity analysis indicated BW and genetic polymorphisms of CYP2C9 and VKORC1 were important factors affecting the warfarin maintenance dose in the study population.

CONCLUSION

The mechanistic model reported is the first to integrate IVIVE with a pharmacokinetic-pharmacodynamic model to describe the association of the warfarin maintenance dose with sex, age, BW and the genotypes of CYP2C9 and VKORC1. The model was effective in predicting S-warfarin clearance and in simulating its plasma concentration-time curve in a cohort of Han Chinese patients. In addition, the model accurately predicted the INR response and warfarin maintenance dose in a cohort of Han Chinese patients.

Indexing glomerular filtration rate to body surface area: clinical consequences

BACKGROUND

Kidney function is mostly expressed in terms of glomerular filtration rate (GFR). A common feature is the expression as ml/min per 1.73 m(2) , which represents the adjustment of the individual kidney function to a standard body surface area (BSA) to allow comparison between individuals. We investigated the impact of indexing GFR to BSA in cancer patients, as this BSA indexation might affect the reported individual kidney function.

METHODS

Cross-sectional study of 895 adults who had their kidney function measured with (51) chrome ethylene diamine tetraacetic acid. Mean values of BSA-indexed GFR vs. mean absolute GFR were analyzed with a t-test for paired data. Bland-Altman plot was used to analyze agreement between the indexed and absolute GFR values.

RESULTS AND CONCLUSION

BSA-GFR in patients with a BSA <1.60 m(2) overestimated GFR with a bias of 10.08 ml/min (11.46%) and underestimated GFR in those with a BSA >2 m(2) with a bias up to -20.76 ml/min (-23.59%). BSA is not a good normalization index (NI) in patients with extreme body sizes. Therefore, until a better NI is found, we recommend clinicians to use the absolute GFR to calculate individual drug chemotherapy dosage as well as express individual kidney function.

Facial plastic surgery area acquisition method based on point cloud mathematical model solution

It is one of the hot research problems nowadays to find a quick and accurate method of acquiring the facial plastic surgery area to provide sufficient but irredundant autologous or in vitro skin source for covering extensive wound, trauma, and burnt area. At present, the acquisition of facial plastic surgery area mainly includes model laser scanning, point cloud data acquisition, pretreatment of point cloud data, three-dimensional model reconstruction, and computation of area. By using this method, the area can be computed accurately, but it is hard to control the random error, and it requires a comparatively longer computation period. In this article, a facial plastic surgery area acquisition method based on point cloud mathematical model solution is proposed. This method applies symmetric treatment to the point cloud based on the pretreatment of point cloud data, through which the comparison diagram color difference map of point cloud error before and after symmetry is obtained. The slicing mathematical model of facial plastic area is got through color difference map diagram. By solving the point cloud data in this area directly, the facial plastic area is acquired. The point cloud data are directly operated in this method, which can accurately and efficiently complete the surgery area computation. The result of the comparative analysis shows the method is effective in facial plastic surgery area.

2D and 3D anatomical analyses of hand dimensions for custom-made gloves

Measuring hand anthropometric data for the development of good-fitting gloves is crucial. In pursuing higher accuracy in hand anthropometric measurements, scanning of hand surfaces with the aids of image analysis system to acquire measurements is an alternative to the manual methods. This study proposes a new hand measuring approach by using 2D and 3D scanning which are evaluated through comparisons of manual measurements. Thirty-three dimensions are measured by using (1) tape and calliper measurement; (2) 2D image analysis; (3) 3D image analysis based on ten captures; and (4) 3D image analysis based on three captures, respectively. Repeated-measures ANOVA, correlation analysis and RMSE are used to examine the results. The hand dimensions obtained from the four methods are highly linearly correlated. Hand data taken from 3D image analysis has no significant difference compared with manual measurements on hand and wrist circumferences, length and breadth dimension, regardless of the number of captures.

Estimation of body surface area in various childhood ages--validation of the Mosteller formula

AIM

The aim of the present study was to validate the Mosteller formula for the estimation of body surface area (BSA) in various childhood ages. Many physiological processes including drug metabolism correlate with values for BSA. In addition, dosing of many drugs, especially drugs with low therapeutic index, for example, anti-neoplastics, are based on estimated values of BSA.

METHODS

Published data from measured BSA in 268 children and infants (median age: 8 month; range: 0-18 years) were compared with BSA values estimated by the Mosteller formula. Correlation between estimated and measured BSA values was performed by the Spearman rank correlation. Bias and precision were evaluated as outlined by Sheiner and Beal. Measured and estimated BSA values were compared by the Eksborg's plot.

RESULTS

Measured values of BSA and BSA values estimated by the Mosteller formula were closely correlated (r(s) = 0.973; p < 0.0001). The formula of Mosteller had with a precision of 9.38% and underestimated BSA by 4.06%. The quotients Estimated/Measured BSA were within the range 0.9-1.1 in 71.3% of the observations, but deviation up to 35% occurred.

CONCLUSION

The Mosteller formula underestimates BSA in the paediatric population and must be used with precautions because of low precision, most pronounced in neonates and infants.

Technical note: Criterion validity of whole body surface area equations: a comparison using 3D laser scanning

Measurements of whole body surface area (WBSA) have important applications in numerous fields including biological anthropology, clinical medicine, biomechanics, and sports science. Currently, WBSA is most often estimated using predictive equations due to the complex and time consuming methods required for direct measurement. The main aim of this study was to identify whether there were significant and meaningful differences between WBSA measurements taken using a whole body three-dimensional (3D) scanner (criterion measure) and the estimates derived from each WBSA equation identified from a systematic review. The study also aimed to determine whether differences varied according to body mass index (BMI), sex, or athletic status. Fifteen WBSA equations were compared with direct measurements taken on 1,714 young adult subjects, aged 18-30 years, using the Vitus Smart 3D whole body scanner, including 1,452 subjects (753 males, 699 females) from the general Australian population and 262 rowers (148 males, 114 females). Mixed-design analysis of variances determined significant differences and accuracy was quantified using Bland-Altman analysis and effect sizes. Thirteen of the 15 equations overestimated WBSA. With a few exceptions, equations were accurate with a low-systematic error (bias ≤2%) and low-random error (standard deviation of the differences 1.5-3.0%). However, BMI did have a substantial impact with the accuracy of some WBSA equations varying between the four BMI categories. The Shuter and Aslani: Eur J Appl Physiol 82 (2000) 250-254 equation was identified as the most accurate equation and should be used for Western populations 18-30 years of age. Care must be taken when deciding which equation to use when estimating WBSA.