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  1. Surgical Drill Bit Design and Thermomechanical Damage in Bone Drilling: A Review
    Akhbar MFA, Sulong AW
    Ann Biomed Eng, 2021 Jan;49(1):29-56.
    PMID: 32860111 DOI: 10.1007/s10439-020-02600-2
    As drilling generates substantial bone thermomechanical damage due to inappropriate cutting tool selection, researchers have proposed various approaches to mitigate this problem. Among these, improving the drill bit design is one of the most feasible and economical solutions. The theory and applications in drill design have been progressing, and research has been published in various fields. However, pieces of information on drill design are dispersed, and no comprehensive review paper focusing on this topic. Systemizing this information is crucial and, therefore, the impetus of this review. Here, we review not only the state-of-the-art in drill bit designs-advances in surgical drill bit design-but also the influences of each drill bit geometries on bone damage. Also, this work provides future directions for this topic and guidelines for designing an improved surgical drill bit. The information in this paper would be useful as a one-stop document for clinicians, engineers, and researchers who require information related to the tool design in bone drilling surgery.
    Matched MeSH terms: Hot Temperature/adverse effects*
  2. Fulltext An Evidence-Based Review of Impacts, Strategies and Tools to Mitigate Urban Heat Islands
    Leal Filho W, Echevarria Icaza L, Emanche VO, Quasem Al-Amin A
    Int J Environ Res Public Health, 2017 12 19;14(12).
    PMID: 29257100 DOI: 10.3390/ijerph14121600
    The impacts of climate changes on cities, which are home to over half of the world's population, are already being felt. In many cases, the intensive speed with which urban centres have been growing means that little attention has been paid to the role played by climatic factors in maintaining quality of life. Among the negative consequences of rapid city growth is the expansion of the problems posed by urban heat islands (UHIs), defined as areas in a city that are much warmer than other sites, especially in comparison with rural areas. This paper analyses the consistency of the UHI-related literature in three stages: first it outlines its characteristics and impacts in a wide variety of cities around the world, which poses pressures to public health in many different countries. Then it introduces strategies which may be employed in order to reduce its effects, and finally it analyses available tools to systematize the initial high level assessment of the phenomenon for multidisciplinary teams involved in the urban planning process. The analysis of literature on the characteristics, impacts, strategies and digital tools to assess on the UHI, reveals the wide variety of parameters, methods, tools and strategies analysed and suggested in the different studies, which does not always allow to compare or standardize the diagnosis or solutions.
    Matched MeSH terms: Hot Temperature/adverse effects*
  3. Effect of microwave heating on the quality characteristics of canola oil in presence of palm olein
    Ali MA, Nouruddeen ZB, Muhamad II, Latip RA, Othman NH
    Acta Sci Pol Technol Aliment, 2013 Jul-Sep;12(3):241-52.
    PMID: 24584953
    Microwave heating is one of the most attractive cooking methods for food preparation, commonly employed in households and especially in restaurants for its high speed and convenience. The chemical constituents of oils that degrade during microwave heating do so at rates that vary with heating temperature and time in a similar manner to other type of processing methods. The rate of quality characteristics of the oil depends on the fatty acid composition and the minor components during heating. Addition of oxidative-stable palm olein (PO) to heat sensitive canola oil (CO), may affect the quality characteristics of CO during microwave heating. The aim of this study was to evaluate how heat treatments by microwave oven affect the quality of CO in presence of PO.
    Matched MeSH terms: Hot Temperature/adverse effects*
  4. Use of palm mid-fraction in dark chocolate as base filling centre at different storage temperatures
    Jinap S, Ali AA, Man YB, Suria AM
    Int J Food Sci Nutr, 2000 Nov;51(6):489-99.
    PMID: 11271851
    Dark chocolates filled with palm mid-fraction (PMF) were stored at different temperatures to evaluate the physical and chemical changes. Storage at low temperature (18 degrees C) reduces the PMF migration to negligible extent. Higher storage temperatures (30 and 35 degrees C) increased the PMF migration from the filling centre into the chocolate coating. As a consequence of fat migration, fatty acid composition, triglyceride composition, hardness, solid fat content, melting point and polymorphic structure changed, leading to bloom formation, which started by fat migration and was influenced by recrystallization tendency within the chocolate coating.
    Matched MeSH terms: Hot Temperature/adverse effects*
  5. The effect of early-age food restriction on heat shock protein 70 response in heat-stressed female broiler chickens
    Zulkifli I, Che Norma MT, Israf DA, Omar AR
    Br Poult Sci, 2002 Mar;43(1):141-5.
    PMID: 12003331
    1. This study was conducted to determine the effect of early-age food restriction on heat shock protein (hsp) 70 synthesis in the brains of female broiler chickens exposed to high ambient temperatures. 2. Chicks were brooded for 3 weeks and then maintained at 24+/-1 degrees C. 3. On d 0, chicks were assigned to one of 4 feeding regimens; each regimen was applied to 4 cages of chicks. The regimens were: (1) ad libitum feeding (AL); (2) 80% food restriction at 4, 5 and 6 d of age (F80); (3) 60% food restriction at 4, 5, and 6 d of age (F60); and (4) 40% food restriction at 4, 5 and 6 d of age (F40). From d 35 to d 41, all chicks were subjected to 38+/-1 degrees C for 2 h/d. 4. One day following food restriction (d 7), hsp 70 expression in the brain samples of F60 and F40 chicks was augmented but not those fed AL and F80. 5. Prior to the heat challenge (d 35), all chicks had similar hsp 70 response. Irrespective of feeding regimen, there was a marked increase in hsp 70 expression after 4 d of heat treatment (d 38). Following 7 d of heat exposure (d 41), except for the F60 chicks, the augmented hsp 70 expression in the brains of AL, F80 and F40 birds was not maintained. 6. Enhancement of hsp 70 expression was noted in birds subjected to F60, but not AL, F80 or F40, throughout the period of heat exposure.
    Matched MeSH terms: Hot Temperature/adverse effects
  6. Effects of simulated warming on bacterial diversity and abundance in tropical soils from East Malaysia using open top chambers
    Chua CY, Wong CMVL
    Can J Microbiol, 2021 Jan;67(1):64-74.
    PMID: 33084348 DOI: 10.1139/cjm-2019-0461
    The effects of global warming are increasingly evident, where global surface temperatures and atmospheric concentration of carbon dioxide have increased in past decades. Given the role of terrestrial bacteria in various ecological functions, it is important to understand how terrestrial bacteria would respond towards higher environmental temperatures. This study aims to determine soil bacterial diversity in the tropics and their response towards in situ warming using an open-top chamber (OTC). OTCs were set up in areas exposed to sunlight throughout the year in the tropical region in Malaysia. Soil samples were collected every 3 months to monitor changes in bacterial diversity using V3-V4 16S rDNA amplicon sequencing inside the OTCs (treatment plots) and outside the OTCs (control plots). After 12 months of simulated warming, an average increase of 0.81 to 1.15 °C was recorded in treatment plots. Significant changes in the relative abundance of bacterial phyla such as Bacteroidetes and Chloroflexi were reported. Increases in the relative abundance of Actinobacteria were also observed in treatment plots after 12 months. Substantial changes were observed at the genus level, where most bacterial genera decreased in relative abundance after 12 months. This study demonstrated that warming can alter soil bacteria in tropical soils from Kota Kinabalu.
    Matched MeSH terms: Hot Temperature/adverse effects
  7. Comparison of thermoregulatory responses to heat between Malaysian and Japanese males during leg immersion
    Wijayanto T, Wakabayashi H, Lee JY, Hashiguchi N, Saat M, Tochihara Y
    Int J Biometeorol, 2011 Jul;55(4):491-500.
    PMID: 20824480 DOI: 10.1007/s00484-010-0358-5
    The objective of this study was to investigate thermoregulatory responses to heat in tropical (Malaysian) and temperate (Japanese) natives, during 60 min of passive heating. Ten Japanese (mean ages: 20.8 ± 0.9 years) and ten Malaysian males (mean ages: 22.3 ± 1.6 years) with matched morphological characteristics and physical fitness participated in this study. Passive heating was induced through leg immersion in hot water (42°C) for 60 min under conditions of 28°C air temperature and 50% RH. Local sweat rate on the forehead and thigh were significantly lower in Malaysians during leg immersion, but no significant differences in total sweat rate were observed between Malaysians (86.3 ± 11.8 g m(-2) h(-1)) and Japanese (83.2 ± 6.4 g m(-2) h(-1)) after leg immersion. In addition, Malaysians displayed a smaller rise in rectal temperature (0.3 ± 0.1°C) than Japanese (0.7 ± 0.1°C) during leg immersion, with a greater increase in hand skin temperature. Skin blood flow was significantly lower on the forehead and forearm in Malaysians during leg immersion. No significant different in mean skin temperature during leg immersion was observed between the two groups. These findings indicated that regional differences in body sweating distribution might exist between Malaysians and Japanese during heat exposure, with more uniform distribution of local sweat rate over the whole body among tropical Malaysians. Altogether, Malaysians appear to display enhanced efficiency of thermal sweating and thermoregulatory responses in dissipating heat loss during heat loading. Thermoregulatory differences between tropical and temperate natives in this study can be interpreted as a result of heat adaptations to physiological function.
    Matched MeSH terms: Hot Temperature/adverse effects
  8. Comparative toxicity of nine metals to two Malaysian aquatic dipterian larvae with reference to temperature variation
    Vedamanikam VJ, Shazilli NA
    Bull Environ Contam Toxicol, 2008 Jun;80(6):516-20.
    PMID: 18414763 DOI: 10.1007/s00128-008-9413-x
    A study was conducted to determine the suitability of using selected aquatic dipterian larvae for biomonitoring bioassays. The organisms included a member of the biting midge family that was identified as Culicoides furens and a member of the non-biting midge family, identified as Chironomus plumosus. Median lethal toxicity tests were conducted to observe the variation between metal sensitivities between the two larval forms and how variations in temperature could affect the experimental setup. Nine heavy metals were used in the study. It was observed that the 96 h LC(50) (in mg/L) for the different metals was found to be Zn-16.21 (18.55 +/- 13.87); Cr-0.96 (1.08 +/- 0.84); Ag-4.22 (6.87 +/- 1.57); Ni-0.42 (0.59 +/- 0.25); Hg-0.42 (0.59 +/- 0.25); Pb-16.21 (18.31 +/- 14.11); Cu-42.24 (45.18 +/- 39.30); Mn-4.22 (7.19 +/- 1.25); Cd-0.42 (0.59 +/- 0.25) for the Chironomus plumosus and Zn-4.22 (6.56 +/- 1.88); Cr-0.42 (0.54 +/- 0.30); Ag-0.42 (0.54 +/- 0.30); Ni-0.42 (0.54 +/- 0.30); Hg-0.04 (0.07 +/- 0.01); Pb-0.42 (0.54 +/- 0.30); Cu-42.24 (45.18 +/- 39.30); Mn-4.22 (6.56 +/- 1.88); Cd-0.42 (0.54 +/- 0.30) in the case of the Culicoides furens. With temperature as a variable the LC(50) values were observed to increase from 2.51 mg/L at 10 degrees C to 4.22 ppm at 30 degrees C and to reduce slightly to 3.72 mg/L at 35 degrees C as seen in the case of Zn. It was also observed that at 40 degrees C thermal toxicity and chemical toxicity overlapped as 100% mortality was observed in the controls. This trend was observed in all metals for both C. plumosus and C. furens. Thus indicating temperature played an important role in determining LC(50) values of toxicants.
    Matched MeSH terms: Hot Temperature/adverse effects*
  9. Nasopharyngeal carcinoma in Malaysian Chinese: occupational exposures to particles, formaldehyde and heat
    Armstrong RW, Imrey PB, Lye MS, Armstrong MJ, Yu MC, Sani S
    Int J Epidemiol, 2000 Dec;29(6):991-8.
    PMID: 11101539 DOI: 10.1093/ije/29.6.991
    BACKGROUND: During 1990-1992, 282 Chinese residents of Selangor and the Federal Territory, Malaysia with histologically confirmed nasopharyngeal carcinoma (NPC) were interviewed about occupational history, diet, alcohol consumption, and tobacco use, as were an equal number of Malaysian Chinese population controls, pair-matched to cases by age and sex.

    METHODS: Exposures to 20 kinds of workplace substances, solar and industrial heat, and cigarette smoke, were analysed by univariate and multivariate methods.

    RESULTS: Nasopharyngeal carcinoma was associated with occupational exposures to construction, metal and wood dusts; motor fuel and oil; paints and varnishes; certain other chemicals; industrial heat; solar heat from outdoor occupations; certain smokes; cigarette smoking; and childhood exposure to parental smoking. After adjustment for risk from diet and cigarette smoke, only wood dust (OR = 2.36; 95% CI : 1.33- 4.19), and industrial heat (OR = 2.21; 95% CI : 1.12-4.33) remained clearly associated. Wood dust remained statistically significant after further adjustment for social class. No significant crude or adjusted association was found between NPC and formaldehyde (adjusted OR = 0.71; 95% CI : 0.34-1.43).

    CONCLUSIONS: This study supports previous findings that some occupational inhalants are risk factors for NPC. The statistical effect of wood dust remained substantial after adjustment for diet, cigarette smoke, and social class. Intense industrial heat emerged as a previously unreported risk factor, statistically significant even after adjustment for diet and cigarette smoke. No association was found between NPC and formaldehyde.
    Matched MeSH terms: Hot Temperature/adverse effects*
  10. Fulltext The Impact of Heat on Health and Productivity among Maize Farmers in a Tropical Climate Area
    Sadiq LS, Hashim Z, Osman M
    J Environ Public Health, 2019;2019:9896410.
    PMID: 31061664 DOI: 10.1155/2019/9896410
    Background: Heat stress disorders may cause negative health outcome and subsequent productivity reduction especially in those who work under direct sunlight for an extended number of hours.

    Objective: This study assessed the impact of heat on the health and productivity among maize farmers in a hot tropical country.

    Methods: A cross-sectional study was conducted among 396 maize farmers, randomly selected across Gombe province, Nigeria. The wet bulb globe temperature monitor (WBGT) Model QuesTemp036 was used in determining the heat index. Health was determined using a validated questionnaire, while productivity was determined by recording work output based on the number of ridges cultivated during the working hours.

    Results: The farms recorded mean heat index with standard deviation (SD) of 31.56 (2.19) and 34.08 (1.54) in the hours of 9 am to 12 pm and 12-3 pm respectively, which exceeded the threshold level set by the ACGIH. Heavy sweating (93.2%), tiredness (48.5%), dizziness (34.1%), and headache (40.4%) were experienced by the respondents almost on daily basis. The finding further showed a significant difference in the farmers' productivity during the three time duration of the work day (p < 0.001). The productivity was significantly higher between the hours of 6-9 am (p < 0.001) and 12-3 pm (p < 0.001), compared to the hours of 9 am to 12 pm (p < 0.001). The factors that significantly predict the productivity outcome include temperature (p < 0.001), gender (p < 0.001), age (p=0.033), and BMI (p=0.008).

    Conclusion: The farmers were frequently experiencing heat exhaustion which decreased their productivity.

    Matched MeSH terms: Hot Temperature/adverse effects*
  11. Effects of zinc oxide nanoparticles on growth performance and concentrations of malondialdehyde, zinc in tissues, and corticosterone in broiler chickens under heat stress conditions
    Ramiah SK, Awad EA, Mookiah S, Idrus Z
    Poult Sci, 2019 Sep 01;98(9):3828-3838.
    PMID: 30839088 DOI: 10.3382/ps/pez093
    The use of nanominerals, such as nano-zinc, represents a promising and emerging technology in the animal farming industry. Due to the small particle size and bioavailability of nano-zinc, it can be easily assimilated in the digestive system, thereby reducing excretion and environmental pollution. The present study was conducted to assess the effects of zinc oxide nanoparticles (ZnONPs) on the growth performance, zinc (Zn) concentration in edible tissues, thiobarbituric acid reactive substance, and corticosterone concentrations in broilers reared under normal or heat stress environmental conditions. The experiment was performed with a completely randomized design based on a 4 × 2 factorial arrangement consisting of 4 diets (basal diet + 60 mg/kg conventional zinc oxide as control diet; basal diet + 40 mg/kg of ZnONPs; basal diet + 60 mg/kg of ZnONPs; and basal diet + 100 mg/kg of ZnONPs) and 2 environmental conditions (normal and heat stress). On day 22, birds from each dietary group were divided equally to normal temperature (23 ± 1°C throughout) or heat stress conditions (34 ± 1°C daily for 6 h from 10:00 am until 4:00 pm). From 1 to 42 D of age, the broiler chickens fed 100 mg/kg ZnONPs exhibited lower feed intake and feed conversion ratio than the control. The accumulation of Zn in the liver of broilers was significantly higher among all treatment groups compared to breast and thigh muscle tissues regardless of the temperature conditions. At 40 and 60 mg/kg ZnONPs, the malondialdehyde content increased in thigh muscle of broilers at 7 D postmortem, indicating that ZnONPs potentially inhibited the antioxidant system in muscle tissues. The control and ZnONPs at 40 mg/kg and 60 mg/kg led to low serum corticosterone levels that may be attributed to the antioxidant and antistress properties of Zn. Taken together, although supplementation with ZnONPs at 40 mg/kg and 60 mg/kg alleviated the negative results of heat stress, further research is needed to determine the optimal level of dietary ZnONPs supplementation.
    Matched MeSH terms: Hot Temperature/adverse effects*
  12. Fulltext Reheating of soy oil is detrimental to bone metabolism in oestrogen deficient rats
    Ima-Nirwana S, Ahmad SN, Yee LJ, Loh HC, Yew SF, Norazlina M, et al.
    Singapore Med J, 2007 Mar;48(3):200-6.
    PMID: 17342287
    The short-term and long- term effects of heated soy oil on bone metabolism in ovariectomised Sprague-Dawley rats were studied.
    Matched MeSH terms: Hot Temperature/adverse effects*
  13. Dietary supplementation of Zingiber officinale and Zingiber zerumbet to heat-stressed broiler chickens and its effect on heat shock protein 70 expression, blood parameters and body temperature
    Hasheimi SR, Zulkifli I, Somchit MN, Zunita Z, Loh TC, Soleimani AF, et al.
    J Anim Physiol Anim Nutr (Berl), 2013 Aug;97(4):632-8.
    PMID: 22533311 DOI: 10.1111/j.1439-0396.2012.01302.x
    The present study was conducted to assess the effects of dietary supplementation of Zingiber officinale and Zingiber zerumbet and to heat-stressed broiler chickens on heat shock protein (HSP) 70 density, plasma corticosterone concentration (CORT), heterophil to lymphocyte ratio (HLR) and body temperature. Beginning from day 28, chicks were divided into five dietary groups: (i) basal diet (control), (ii) basal diet +1%Z. zerumbet powder (ZZ1%), (iii) basal diet +2%Z. zerumbet powder (ZZ2%), (iv) basal diet +1%Z. officinale powder (ZO1%) and (v) basal diet +2%Z. officinale powder (ZO2%). From day 35-42, heat stress was induced by exposing birds to 38±1°C and 80% RH for 2 h/day. Irrespective of diet, heat challenge elevated HSP70 expression, CORT and HLR on day 42. On day 42, following heat challenge, the ZZ1% birds showed lower body temperatures than those of control, ZO1% and ZO2%. Neither CORT nor HLR was significantly affected by diet. The ZO2% and ZZ2% diets enhanced HSP70 expression when compared to the control groups. We concluded that dietary supplementation of Z. officinale and Z. zerumbet powder may induce HSP70 reaction in broiler chickens exposed to heat stress.
    Matched MeSH terms: Hot Temperature/adverse effects*
  14. Fulltext The role of heat shock protein 70 in resistance to Salmonella enteritidis in broiler chickens subjected to neonatal feed restriction and thermal stress
    Soleimani AF, Zulkifli I, Hair-Bejo M, Omar AR, Raha AR
    Poult Sci, 2012 Feb;91(2):340-5.
    PMID: 22252346 DOI: 10.3382/ps.2011-01703
    Environmental stressors may influence chicken performance and susceptibility to pathogens, such as Salmonella enteritidis. This study was conducted to determine the effects of heat shock protein (Hsp)70 expression on resistance to Salmonella enteritidis infection in broiler chickens subjected to heat exposure. Chicks were divided into 3 feeding regimens: ad libitum feeding (control); 60% feed restriction on d 4, 5, and 6 (FR60); and 60% feed restriction on d 4, 5, and 6 plus 1,500 mg/kg of quercetin (FR60Q). On d 35, all of the chickens were individually inoculated with 1 mL of Salmonella enteritidis (1.5 × 10(8) cfu/bird) and exposed to an ambient temperature of 37 ± 1°C and 70% RH for 3 h/d. The FR60 and FR60Q chickens had significantly lower Salmonella enteritidis colonization and lower Hsp70 expression than that of the control chickens following the heat exposure period. The least colonization was observed in the FR60Q group (1.38 log(10) cfu/g in the spleen and 1.96 log(10) cfu/g in the cecal content) and the highest was in the control group (2.1 log(10) cfu/g in the spleen and 4.42 log(10) cfu/g in the cecal content). It appears that neonatal feed restriction can enhance resistance to Salmonella enteritidis colonization in heat-stressed broiler chicks, and the underlying mechanism could be associated with the lower expression of Hsp70.
    Matched MeSH terms: Hot Temperature/adverse effects
  15. Comparison of heat dissipation response between Malaysian and Japanese males during exercise in humid heat stress
    Wakabayashi H, Wijayanto T, Lee JY, Hashiguchi N, Saat M, Tochihara Y
    Int J Biometeorol, 2011 Jul;55(4):509-17.
    PMID: 20949285 DOI: 10.1007/s00484-010-0374-5
    This study investigated the differences in heat dissipation response to intense heat stress during exercise in hot and humid environments between tropical and temperate indigenes with matched physical characteristics. Ten Japanese (JP) and ten Malaysian (MY) males participated in this study. Subjects performed exercise for 60 min at 55% peak oxygen uptake in 32°C air with 70% relative humidity, followed by 30 min recovery. The increase in rectal temperature (T(re)) was smaller in MY during exercise compared to JP. The local sweat rate and total body mass loss were similar in both groups. Both skin blood flow and mean skin temperature was lower in MY compared to JP. A significantly greater increase in hand skin temperature was observed in MY during exercise, which is attributable to heat loss due to the greater surface area to mass ratio and large number of arteriovenous anastomoses. Also, the smaller increase in T(re) in MY may be explained by the presence of a significantly greater core-skin temperature gradient in MY than JP. The thermal gradient is also a major factor in increasing the convective heat transfer from core to skin as well as skin blood flow. It is concluded that the greater core-skin temperature gradient observed in MY is responsible for the smaller increase in T(re).
    Matched MeSH terms: Hot Temperature/adverse effects
  16. Effect of ionizing radiation on some quality attributes of nutraceutically valued lotus seeds
    Bhat R, Karim AA
    Int J Food Sci Nutr, 2009;60 Suppl 4:9-20.
    PMID: 19462319 DOI: 10.1080/09637480802241626
    Radiation processing has been employed successfully for value addition of food and agricultural products. Preliminary studies were undertaken to evaluate the changes induced by ionizing radiation (up to 30 kGy), in the form of gamma irradiation and electron beam irradiation, on some quality attributes and nutritive values of nutraceutically valued lotus seeds. Significant loss in seed firmness was recorded between control and irradiated seeds, irrespective of radiation source. Similarly, the specific viscosity of irradiated lotus seeds decreased significantly up to a dose of 7.5 kGy. Starch increased after exposure to gamma or electron beam irradiation, whereas the total phenolic contents were decreased. Gamma irradiation revealed an enhancement in protein, while the electron beam showed a decrease. Partial oxidation of the seeds during radiation treatments might have occurred as evidenced from the decomposition profiles (thermogravimetry) during heating. It is evident that ionizing radiation brought about significant and variable changes in the quality and nutritive values of lotus seed. Further exploration of this technology for safety and quality is warranted.
    Matched MeSH terms: Hot Temperature/adverse effects
  17. Recycled palm oil is better than soy oil in maintaining bone properties in a menopausal syndrome model of ovariectomized rat
    Shuid AN, Chuan LH, Mohamed N, Jaarin K, Fong YS, Soelaiman IN
    Asia Pac J Clin Nutr, 2007;16(3):393-402.
    PMID: 17704019
    Palm oil is shown to have antioxidant, anticancer and cholesterol lowering effects. It is resistant to oxidation when heated compared to other frying oils such as soy oil. When a frying oil is heated repeatedly, it forms toxic degradation products, such as aldehydes which when consumed, may be absorbed into the systemic circulation. We have studied the effects of taking soy or palm oil that were mixed with rat chow on the bone histomorphometric parameters of ovariectomised rats. Female Sprague-Dawley rats were divided into eight groups: (1) normal control group; (2) ovariectomised-control group; (3) ovariectomised and fresh soy oil; (4) ovariectomised and soy oil heated once; (5) ovariectomised and soy oil heated five times; (6) ovariectomised and fresh palm oil; (7) ovariectomised and palm oil heated once; (8) ovariectomised and palm oil heated five times. These oils were mixed with rat chow at weight ratio of 15:100 and were given to the rats daily for six months. Ovariectomy had caused negative effects on the bone histomorphometric parameters. Ingestion of both fresh and once-heated oils, were able to offer protections against the negative effects of ovariectomy, but these protections were lost when the oils were heated five times. Soy oil that was heated five times actually worsens the histomorphometric parameters of ovariectomised rats. Therefore, it may be better for postmenopausal who are at risk of osteoporosis to use palm oil as frying oil especially if they practice recycling of frying oils.
    Matched MeSH terms: Hot Temperature/adverse effects*
  18. Effects of hydration practices on the severity of heat-related illness among municipal workers during a heat wave phenomenon
    Mansor Z, Rosnah I, Ismail NH, Hashim JH
    Med J Malaysia, 2019 08;74(4):275-280.
    PMID: 31424033
    INTRODUCTION: The continue rise in temperatures due to climate change increases the risk of heat-related illness (HRI) among outdoor workers. This study aims to evaluate the effects of hydration practices on the severity of HRI during a heat wave episode among municipal workers in Negeri Sembilan.

    METHOD: A cross-sectional study was performed in March and April 2016. The outdoor temperatures were measured using the wet-bulb globe temperature (WBGT) tool. The participants completed a self-administered questionnaire containing sociodemographic factors prior to work shift; while working profile, hydration practices, and HRI symptoms at the end of work shift. The hydration status of the respondents was assessed by direct observation of their urine colour. Multiple logistic regression was performed to ascertain the effects of age, working profile, hydration practice, history of previous HRI, and hydration status on the likelihood that outdoor workers having moderate to severe HRI.

    RESULTS: A total of 320 respondents completed the questionnaire. The mean (standard deviation) outdoor workplace temperature was 30.5°C (SD 0.53°C). The percentage of respondents who experienced moderate to severe HRI was 44.1%. The likelihood that outdoor workers experienced moderate to severe HRI symptoms was associated with irregular fluid intake [odds ratio (OR): 16.11, 95% confidence interval (95%CI): 4.11; 63.20]; consumption of non-plain water (OR: 5.92, 95%CI: 2.79; 12.56); dehydration (OR: 3.32, 95%CI: 1.92; 5.74); and increasing outdoor workplace temperature (OR: 1.85, 95%CI: 1.09; 3.11).

    CONCLUSION: Irregular drinking pattern and non-plain fluid intake was found to have a large effect on HRI severity among outdoor workers exposed high temperatures during a heat wave phenomenon.

    Matched MeSH terms: Hot Temperature/adverse effects*
  19. Fulltext Investigations concerning the impact of consumption of hot beverages on acute cytotoxic and genotoxic effects in oral mucosa cells
    Ernst B, Setayesh T, Nersesyan A, Kundi M, Fenech M, Bolognesi C, et al.
    Sci Rep, 2021 11 26;11(1):23014.
    PMID: 34836993 DOI: 10.1038/s41598-021-01995-9
    Consumption of very hot beverages and foods increases the incidence of oral and esophageal cancer but the mechanisms are not known and the critical temperature is not well defined. We realized a study with exfoliated cells from the oral cavity of individuals (n = 73) that live in an area in Iran which has the highest incidence of EC worldwide. Consumption of beverages at very high temperatures is a characteristic feature of this population. We analyzed biomarkers which are (i) indicative for genetic instability (micronuclei that are formed as a consequence of chromosomal damage, nuclear buds which are a consequence of gene amplifications and binucleated cells which reflect mitotic disturbances), (ii) markers that reflect cytotoxic effects (condensed chromatin, karyorrhectic, karyolitic and pyknotic cells), (iii) furthermore, we determined the number of basal cells which is indicative for the regenerative capacity of the buccal mucosa. The impact of the drinking temperature on the frequencies of these parameters was monitored with thermometers. We found no evidence for induction of genetic damage but an increase of the cytotoxic effects with the temperature was evident. This effect was paralleled by an increase of the cell division rate of the mucosa which was observed when the temperature exceeded 60 °C. Our findings indicate that cancer in the upper digestive tract in drinkers of very hot beverages is not caused by damage of the genetic material but by an increase of the cell division rate as a consequence of cytotoxic effects which take place at temperatures over 60 °C. It is known from earlier experiments with rodents that increased cell divisions lead to tumor promotion in the esophagus. Our findings provide a mechanistic explanation and indicate that increased cancer risks can be expected when the drinking temperature of beverages exceeds 60 °C.
    Matched MeSH terms: Hot Temperature/adverse effects*
  20. Fulltext Association of elevated blood pressure and impaired vasorelaxation in experimental Sprague-Dawley rats fed with heated vegetable oil
    Leong XF, Mustafa MR, Das S, Jaarin K
    Lipids Health Dis, 2010;9:66.
    PMID: 20573259 DOI: 10.1186/1476-511X-9-66
    Poor control of blood pressure leads to hypertension which is a major risk factor for development of cardiovascular disease. The present study aimed to explore possible mechanisms of elevation in blood pressure following consumption of heated vegetable oil.
    Matched MeSH terms: Hot Temperature/adverse effects*
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