25G pars plana vitrectomy combined with Dexamethasone intravitreal implants for the treatment of vitreous hemorrhage and diabetic macular edema secondary to proliferative diabetic retinopathy / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To evaluate the clinical effect of 25G pars plana vitrectomy(PPV)combined with dexamethasone intravitreal implant(DEX)on the treatment of vitreous hemorrhage and diabetic macular edema(DME)secondary to proliferative diabetic retinopathy(PDR).METHODS: Prospective clinical case study. A total of 40 patients(40 eyes)with vitreous hemorrhage and DME secondary to PDR who treated in Tianjin Eye Hospital from July 2020 to January 2022 were included in the study. All eyes underwent 25G PPV and cataract phacoemulsification. The patients were randomly divided into PPV group(20 eyes)and PPV+DEX group(20 eyes). Best corrected visual acuity(BCVA), intraocular pressure, and central macular thickness(CMT)of the patients before and 1, 3, 6mo after the operation were compared.RESULTS: All patients were followed up for 6mo. The BCVA of the patients in the PPV+DEX group improved better than that of the PPV group at 1, 3 and 6mo after surgery(P<0.05). CMT of the PPV+DEX group was lower than that of the PPV group at 1mo after operation(P<0.05). Retinal neovascularization or CMT regression with less than 5% was found in 8 eyes in the PPV group, who were supplemented with anti-vascular endothelial growth factor, while it was found in only 1 eye in the PPV+DEX group(P<0.05).CONCLUSION: PPV combined with DEX could yield synergies, which provide better therapeutic effect for the patients with vitreous hemorrhage and DME secondary to PDR.

Estimation on organ absorbed dose conversion coefficient for patients during coronary intervention procedure with Monte Carlo method / 中华放射医学与防护杂志

Objective:To calculate the conversion coefficient from dose area product (DAP) to organ absorbed dose by Monte Carlo method in order to conveniently estimate doses to patient organ during coronary intervention procedure.Methods:The Geant4 Monte Carlo simulation kit was used to calculate the organ absorbed dose conversion coefficients by simulating exposure scene.Results:The conversion coefficients used in coronary angiography (CAG) for lung, bone marrow, liver and heart were (0.283±0.068), (0.169±0.049), (0.110±0.077) and (0.080±0.032) mGy/(Gy·cm 2) for male, and (0.376±0.121), (0.192±0.056), (0.153±0.105), and (0.102±0.033) mGy/(Gy·cm 2) for female, respectively. These were similar to those in the case of percutaneous coronary intervention (PCI). The DAPs for different interventional procedures were statistically significant ( t=-6.012, P<0.05). The DAPs for difference gender groups had no statistically significant ( P>0.05). Conclusions:Conversion coefficient for organ absorbed dose has little correlation with CAG and PCI in the same sex group. Dose conversion coefficients for female group are greater than those for male group in the same procedure. Conversion coefficients from DAP to organ absorbed dose calculated with Monte Carlo method can provide convenience for rapidly estimating the organ absorbed dose to clinical patients.

Research progress in measurement methods for210Po and 210Pb in environmental samples / 中国辐射卫生

210Po and 210Pb exist widely in nature, and they have strong toxicity and strong ionization ability, which can cause continuous harm to human health. Therefore, it is of great significance to determine the activity concentrations of 210Po and 210Pb in environmental samples and to evaluate their harmful effects on human health. This article reviews the research progress in analytical methods and measurement techniques of 210Po and 210Pb in environmental samples.

Investigation and analysis of the needs of young students for popularizing science about nuclear and radiation / 中华放射医学与防护杂志

Objective:To be aware of the needs of the young students for nuclear and radiation science popularization, and to provide scientific basis for accurate science popularization.Methods:A simple random sampling method was used to select 1 primary school, 5 middle schools and 2 universities in the Beijing-Tianjin-Hebei region in December 2020. Questionnaires were distributed through teachers. In addition, convenience sampling method was used to distribute questionnaires in friend circle and other areas to expand the survey scope, with a total of 1 345 respondents. SPSS was used to conduct statistical analysis on the basic information of the respondents, the understanding and concern of nuclear and radiation science popularization and the demand for nuclear and radiation science popularization.Results:A total of 1 120 valid questionnaires were collected, of which 52.4% mainly remained at the conceptual level for the cognition of radiation, 52.2% occasionally paid attention to nuclear and radiation science popularization, 65.3% and 41.3% paid attention to life reference and hobbies, respectively. Radiation protection and its sources and effects received high concern, accounting for 72.6% and 68.3% respectively. Illustration and short video were popular science forms of young students, making up 45.7% and 44.3%, respectively. The students of different genders differed in radiation cognition, degree of concern, purpose of concern and content demand for radiation protection science popularization, and the differences are statistically significant( χ2=10.017, 26.859, 56.237, 17.305, P<0.05). Conclusions:Nuclear and radiation science popularization should consistent with the law of public demand, accurately locate the demand characteristics of young students, and consider the characteristics of different genders, concerns over radiation protection, treatment and damage knowledge from the point of life and fun, so as to improve the public′s attention, enhance the national nuclear science culture, and create a good nuclear safety culture atmosphere.

Guilingji Capsules reduce 900 MHz collphone electromagnetic radiation-induced testicular oxidative damage and downregulate Prdx2 protein expression in the rat testis / 中华男科学杂志

Objective@#To investigate the relationship of electromagnetic radiation (EMR) from 900 MHz cellphone frequency with testicular oxidative damage and its influence on the Prdx2 protein expression in the rat testis, and to explore the mechanism of Guilingji Capsules (GC) alleviating oxidative damage to the testis tissue.@*METHODS@#Fifty healthy SD male rats were randomly divided into five groups of equal number, sham-EMR, 4-h EMR, 8-h EMR, 4-h EMR+GC and 8-h EMR+GC and exposed to 900 MHz EMR (370 μW/cm2) for 0, 4 or 8 hours daily for 15 successive days. The rats of the latter two groups were treated intragastrically with GC suspension and those of the first three groups with pure water after exposure to EMR each day. After 15 days of exposure and treatment, all the rats were sacrificed and their testis tissue collected for observation of the histomorphological and ultrastructural changes by HE staining and transmission electron microscopy, measurement of the levels of serum glutathione (GSH), superoxide dismutase (SOD) and malondialdehyde (MDA) with thiobarbiuric acid and determination of the Prdx2 protein expression by immunohistochemistry and Western blot.@*RESULTS@#Compared with the rats in the sham-EMR group, those in the 4-h and 8-h EMR groups showed different degrees of histomorphological and ultrastructural changes in the testis tissue, significantly decreased levels of GSH (［80.62 ± 10.99］ vs ［69.58 ± 4.18］ and ［66.17 ± 8.45］ mg/L, P < 0.05) and SOD (［172.29 ± 10.98］ vs ［158.92 ± 6.46］ and ［148.91 ± 8.60］ U/ml, P < 0.05) and increased level of MDA (［7.51 ± 1.73］ vs ［9.84 ± 1.03］ and ［11.22 ± 2.13］ umol/ml, P < 0.05), even more significantly in the 8-h than in the 4-h EMR group (P < 0.05). In comparison with the sham-EMR group, the expression of the Prdx2 protein was markedly downregulated in the 4-h and 8-h EMR groups (0.56 ± 0.03 vs 0.49 ± 0.03, 0.21 ± 0.01, P < 0.05), but again upregulated in the 4-h and 8-h EMR+GC groups (0.55±0.03 and 0.37±0.04) (P < 0.05).@*CONCLUSIONS@#Electromagnetic radiation from cellphones can cause ultrastructural damage to the testis tissue of male rats, while Guilingji Capsules can alleviate it, presumably by upregulating the Prdx2 protein expression in the testis tissue and reducing testicular oxidative damage.

Positron emission computed tomography/single photon emission computed tomography in Parkinson disease / 中华医学杂志(英文版)

Parkinson disease (PD) is the second-most common neurodegenerative disorder. Its main pathological mechanism is the selective degeneration and deletion of dopaminergic neurons in the dense part of the substantia nigra and the damage of dopaminergic neurons caused by the abnormal deposition of a Lewy body, leading to a decreased dopamine level. Positron emission computed tomography (PET)/single photon emission computed tomography (SPECT) is a molecular imaging technology that can directly or indirectly reflect changes in molecular levels by using a specific tracer. With the research and development on the tracers of related enzymes for labeling dopamine transporter and dopamine receptor and for being involved in dopamine formation, this imaging technology has been applied to all aspects of PD research. It not only contributes to clinical work but also provides an important theoretical basis for exploring the pathological mechanism of PD at a molecular level. Therefore, this review discusses the application value of PET/SPECT in PD in terms of early diagnosis, disease severity evaluation, clinical manifestations, differential diagnosis, and pathological mechanism.

Effect of high dose irradiation on thermoluminescence detector / 国际生物医学工程杂志

Objective To investigate effect of high dose irradiation on the performances of thermolumines-cence detectors (LiF:Mg, Cu, P). Methods The high-dose irradiated thermoluminescence detector was annealed by a thermoluminescence annealing furnace until the annealing was completed, and then the annealed thermoluminescent detector was irradiated 0.5Gy by 137Cs irradiator to verify the accuracy of the thermoluminescentdetector. Results The thermoluminescence detector after high-dose irradiation could not be completely annealed under the temperature condition of 240 ℃, and it could be completely annealed at a high temperature as 400℃. After 0.5 Gy irradiation by 137Cs irradiator, the measurement results of the annealed thermoluminescence detector were significantly smaller, and the dose response and dispersion of the detector were also changed significantly. Conclusions After a more than 5 Gy irradiation, the crystal structure of the thermoluminescence detector has changed, and a high temperature peak above 240 ℃ has appeared, which leads to the failure to completely anneal at normal temperature. Therefore, the thermoluminescence detector can no longer be used for dosimetry after high-dose irradiation.

1H-MRS detection of metabolites in posterior cingulate gyrus of Parkinson disease with cognitive impairment patients / 中国医学影像技术

Objective To investigate the value of 1H-MRS technology combined with linear combination model (LCmodel) software in diagnosis of Parkinson disease (PD) cognitive impairment.Methods Thirty-five PD patients (PD group) and 22 matched healthy subjects (control group) were collected.Patients in PD group were divided into PDN and PDMCI subgroups according to whether having cognitive impairment or not.The concentration of metabolites of posterior cingulate gyrus (PCG)was applied with 1H-MRS technology combined with LCmodel software.The differences of metabolites were compared between the two groups,and the correlations between metabolites level and cognitive status were analyzed.Results The absolute concentrations of metabolites in PDN subgroup were not significantly different from those in control group (all P＞0.05).The absolute concentrations of total creatine (tCr),N-acetyl aspartate (NAA),myo-inositol (mI) and glycerophosphocholine+ phosphocholine (tCho) in PDMCI subgroup were lower than those in control group (all P＜0.05).The absolute concentration of tCr in PDMCI subgroup was lower than that in PDN subgroup (P＜0.05).There was positive correlation among the absolute concentration of tCr (r=0.444,P=0.01),glutathione (GSH;r=0.393,P=0.024) and MMSE scores,as well as among the absolute concentration of tCr (r=0.367,P=0.035),GSH (r=0.376,P=0.031),tCho (r=0.375,P=0.031) and MoCA scores.Conclusion 1 H-MRS technology combined with LCmodel software can quantitatively analyze the changes of metabolites in PCG,therefore being helpful to evaluating PD cognitive impairment.

Surveillance of Creutzfeldt-Jakob diseases cases in Guizhou Province,China, 2010-2015 / 中国人兽共患病学报

We analyze the epidemiology,clinical features,and outcome of the patients with Creutzfeldt-Jakob diseases (CJD) in Guizhou Province from 2010 to 2015.The epidemiology,clinical characteristics and follow-up data of CJD suspected patients obtained from Guizhou CJD surveillance network were analyzed.The testing results of cerebrospinal fluid (CFS) and blood from the patients were also collected and analyzed.Results showed that a total of 11 CJD cases was found from 23 reported CJD suspected patients in Guizhou from 2010 to 2015,including 8 probable sporadic CJD(sCJD) cases,2 possible sCJD cases and 1 genetic CJD(gCJD) case.In 11 cases,rapidly progressive dementia was the major initial symptom,following by mental symptoms,extrapyramidal symptoms,signs and cerebellum cortical blindness.Clinical symptoms of progressive dementia were the main symptoms,following by visual or cerebellar dysfunction,myoclonus,cone system/extrapyramidal dysfunction,and akinetic mutism.Most of cases were abnormal in MRI (45.45％) and 14-3-3 protein detection in CSF(70％).The 14-3-3 blood samples of prion gene 129 amino acids (PRNP)polymorphisms were M/M type,excepting for 1 case gCJD confirmed diagnosis cases with D178N mutation in PRNP gene.Eleven CJD cases did not show season and regional clusterings and vocational tendency.The majority of the cases were male,the median age was 65,and mainly were the Han nationality.For all cases of CJD reported during that year for follow-up,the lost-tofollow-up rate was 27％,and the majority of cases died within one year.The sCJD cases were the majority in CJD cases of Guizhou Province,2010-2015.The epidemiological characteristics were similar to the national monitoring cases in the same period.

Radiological protection assessment of a hospital Clinac 23EX medical electron accelerator construction project / 国际生物医学工程杂志

Objective To evaluate the radiation protection of occupational hazards in a hospital Clinac 23EX medical electronic accelerator construction project so as to ensure the health and safety of the relevant people involved.Methods According to the relevant laws,regulations and standards of China,combined with the relevant materials provided by the construction unit,the radiation protection tests and comprehensive assessment of this project were carried out.Results The performance test results of the medical electron accelerator met the requinements of GB/T 19046-2013 The ambient dose equivalent rate in the workplace was between the background dose rate (0.10 μ,Sv/h) and 11.5 μSv/h,which suggested the computer room shielding met the requirements of radiation protection.The total body effective dose,the for 7 radiation workers were 0.85,1.19,1.64 mSv,respectively,which were lower than the dose management control values of the construction unit and the national standards.Radiation protection supplies and the management system of the construction unit met the national requirements.Conclusions The construction project can effectively control the radioactive occupational hazard factors in normal operation,and the radiation protection facilities have reached the completion requirements.

Clinical observation of ropivacaine compuled with sufentanil for painless childbirth

This study aimed to explore the effect of ropivacaine combined with sufentanil on maternal lactation and infant, which were used by different anesthesia method for painless childbirth. 284 cases of voluntary acceptance of painless childbirth pregnant were involved in this study and divided into control group and observation group. Ropivacaine combined with sufentanil epidural anesthesia [CEA] was used in the control group, and ropivacaine combined with sufentanil epidural block [CSEA] anesthesia was used in the observation group. Meanwhile, maternal colostrum time, postpartum lactation and neonatal Apgar score were analyzed. The colostrum time of the observation group was significantly shorter than that in the control group and the lactation quantity of 24h was significantly higher than that in the control group. There were significant differences between the control and the observation groups [P<0.05]. However, there was no significant difference in neonatal Apgar score [p>0.05]. Combined spinal epidural anesthesia of ropivacaine combined with sufentanil is more conducive to the early postpartum lactation compared with epidural anesthesia. And both of the two ways of anesthesia had no effect on the neonatal Apgar score

Implementation of prevention and control measures to reduce the incidence of healthcare-associated infection caused by multidrug-resistant organisms / 中国感染控制杂志

Objective To explore the effect of implementation of prevention and control measures on reducing the incidence of multidrug-resistant organisms(MDROs)healthcare-associated infection(HAI)rate.Methods Imple-mentation of prevention and control measures on MDROs were strengthened in a hospital in 2012,the relationship between implementation status and change in MDROs infection in the whole hospital were analyzed statistically. Results Through continuous monitoring and tracking,the implementation of prevention and control measures on MDROs continued to be improved,MDRO HAI rate of the second half year was significantly lower than the first half year ([0.29%,119/41 579]vs[0.49%,186/38 252])(χ2 =20.95,P <0.01).Conclusion Continuous monito-ring and tracking of MDROs is helpful for implementing the prevention and control measures on MDROs infection, as well as reducing the incidence of HAI caused by MDROs .

Clinical application of combined anesthesia in cesarean section

This study chose 60 cases of cesarean section for patients with epidural anesthesia [EA] combined spinal epidural anesthesia [CSEA] surgery for clinical application research. Compared with EA, the CSEA could work well in subarachnoid anesthesia and epidural anesthesia. Although it was with less dosage, it had a faster and better effect, good muscle relaxant condition. It not only improved the quality of the surgery, but also reduced the burden of the anesthesiologist

Measurement of gross β activity in urine of normal adults / 中华放射医学与防护杂志

Objective To measure the total β radioactive background level in the urine of normal adults,and to establish the method which can be universally used and satisfy the needs of rapid screening of samples in large batch.Methods A total of 83 urine samples from healthy adults were prepared by evaporation.And the gross β activity in urine was detected by using low background measuring instrument.Results The optimal experimental conditions were in place.The sampled volume was 200 ml,and the samples were turned to nitric acid salinization,ashed at 300℃ for 2 h,and the measured time was 1000 min.To get a more stable result,the urine residues were put aside for 24 h before measurement.The radioactivity in urine of healthy adults was between 9.40-55.92 Bq/L,and showed no correlation with age and sex.Conclusions When the radioactivity in urine is detected under the conditions mentioned above,the sample preparation process is simple and quickly,which can satisfy the needs of large batch sample screening.

Histology study on the dorsal root ganglia of rats with 125I seed brachytherapy at intervertebral foramen / 中华放射医学与防护杂志

Objective To investigate the effect of the histological changes on rat dorsal root ganglia (DRG) after 125I seed brachytherapy.Methods Twelve adult male Sprague-Dawley rats ( 150-180g each) were randomly divided into 6 groups,125I seeds with different activities of 0 (Titanium shell),14.8,18.5,22.2,25.9 and 29.6 MBq were implanted to 6 groups of rats respectively and the behavioral changes of rats were observed.The rats were killed in different periods after implantation,the morphological changes in DRG and surrounding muscle tissue were observed with an Olympus BX51 optical microscope and then the irradiation doses were estimated.Results After 125I seed implantation,the movement function of rats was not affected and the weight of rats gained after 7 days.After the titanium shell implantation,very few mild swelling was induced in neuroganglion cells that still had clear nucleolus and normal cytoplasm.At 14 days after 18.5 MBq seed implantation,cell swelling was more serious and cell dehydrating,nuclear condensation and nuclear fragmentation appeared after 30 days.At 60 days after 29.6 MBq of seed implantation,nuclear dissolution and cytoplasmic shrinkage were induced in a large number of cells.In general,the severity of fibrosis was aggravated with the time post-irradiation and the dose in the muscles around the ganglion.Conclusions After 125I seed implantation,the injury degree of DRG tissue is dose-dependent,and the 125I seed irradiation would have analgesic effect on releasing intractable pain.

Inhibition of Bcl-2 enhances the efficacy of epirubicin chemotherapy in PC-3 prostate cancer cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Overexpression of Bcl-2 protein in cancer cells can inhibit programmed cell death and engender chemoresistance. Bcl-2 antisense oligonucleotide (G3139) has shown its antitumor effects enhanced in preclinical models when combined with taxol-based chemotherapy. This study aimed to investigate the efficacy of G3139 combined with epirubicin in the androgen-independent prostate cancer.</p><p><b>METHODS</b>PC3 prostate cancer cell line was cultured and treated with epirubicin and Bcl-2 antisense oligonucleotide alone or in combination. The effects of therapeutic agents on cells were determined by the MTT assay. Expression of Bcl-2 mRNA and protein was documented by RT-PCR and Western blotting. Apoptosis induction was confirmed by flow cytometric analysis.</p><p><b>RESULTS</b>Bcl-2 antisense oligonucleotide alone produced no cytotoxic effects and the combination of Bcl-2 antisense oligonucleotide with epirubicin sensitized PC-3 cells to the killing effects of chemotherapy. A marked down-regulation of Bcl-2 mRNA and protein was observed after antisense and epirubicin cotreatment. A statistically significantly higher fraction of apoptotic cells was detected by flow-cytometric analysis after epirubicin treatment with prior antisense Bcl-2 transfenction, as compared with mono antisense Bcl-2 or epirubicin treatment.</p><p><b>CONCLUSION</b>These data suggested that inhibition of Bcl-2 expression combined with epirubicin may be an attractive therapeutic strategy in hormone-refractory prostate cancer.</p>

Properties of goat tooth enamel electron spin resonance dosimetry / 中华放射医学与防护杂志

Objectlve To study the properties of goat tooth enamel electron spin resonance (ESR)dosimetry.Methods Tootll enamel samples of goats were achieved by combined mechanical and chemical treatment at the ages of l,2,3,5,and 6 years.respectively and 9 enamel samples of adult molar were obtained.These enamel samples were exposed to 137Cs γ-rays at the cumulative doses of 0,0.5,1.0,2.0,and 5.0 Gy,respectively.ESR spectra Was measured before and after exposure.Results The background signal of goat tooth samples W88 21.5,significantly lower than that of the adult molar samples(39.5).The dusimetric signal intensity of the goat enamel increased with the radiation dose in a linear manner just as that of the human molars.The average radiation sensitivity of the goat tooth samples was(34.3±1.9)/Gy,close to that of the human tooth samples.Conclusions Goat teeth can be used for retrospective radiation dose reconstruction when human teeth are unavailable,in order to previde scientific data for dose reconstruction accurately.

Radiation dose to patients in cardiovascular disease interventional procedures / 中华放射医学与防护杂志

Objective To collect and analyze the radiation dose to patients in cardiovascular interventional procedures and the radiation dose-related indicators,in order to provide a basis for improving radiation protection of patients.MethodsThe clinical data of 26 cases of complete cardiovascular interventional procedures was collected in the municipal Grade A Class Three hospitals,including coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA),and the patient-received radiation doses and other related factors was studied.TLD personal dosimeter radiation field matrix method was used to measure fluorescence time,the entrance skin dose (ESD),the peak skin dose (PSD),dosearea product (DAP) and other indicators.TLD was used to measure the organ dose of the phantom under the cardiovascular interventional procedure condition.ResultsThe fluoroscopy time was (17.7 ±15.6) min during the range of 0.80-42.4 min.The average entrance skin dose (ESD) was (159 ± 138)mGy during the range of 4.40-459 mGy.The peak skin dose (PSD) was (769 ± 705) mGy during the range of 22.6 - 2.43 × 103mGy.The fluorescence time,entrance skin dose (ESD) ,peak skin dose (PSD) of the group CA + PTCA are greater than the group CA and the difference has statistical significan.The peak skin dose and the fluoroscopy time have good linear correlation (r = 0.84,P ＜ 0.01 ).Conclusion The peak skin dose the patient received in cardiovascular interventional radiological operation can be estimated through the fluoroscopy time.

Downregulation of endothelin-1 by somatostatin improves liver function of recipients undergoing adult-to-adult living donor liver transplantation / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The aim of this study was to investigate the possible effect of somatostatin on the liver function of recipients undergoing living donor liver transplantation.</p><p><b>METHODS</b>Forty recipients were randomized into group A (n = 20) and group B (n = 20). Recipients in group A received no somatostatin whereas somatostatin was administrated for recipients in group B perioperatively. Liver function, the plasma concentration of endothelin-1 and nitric oxide, the intragraft expressions of endothelin-1 and inducible nitric oxide syntheses at 2 hours after declamping of the portal vein were compared between the two groups.</p><p><b>RESULTS</b>Compared to group A, alanine transaminase values in group B were significantly reduced at 2 hours after portal vein declamping, at the end of the operation and postoperation day 1 (P < 0.05), whereas aspartate aminotransferase values in group B decreased at 30 minutes after portal vein clamping, at 2 hours after portal vein declamping and at the end of the operation (P < 0.05). Total bilirubin values in group B were reduced significantly at 2 hours after portal vein declamping and at the end of the operation when compared to group A (P < 0.05). Intragraft expression of endothelin-1 was significantly downregulated at 2 hours after declamping of the portal vein accompanied with a reduction of plasma concentration of endothelin-1 in the peripheral blood (P < 0.05).</p><p><b>CONCLUSIONS</b>Somatostatin had a protective effect on liver function during the early phase after declamping of portal vein for recipients undergoing living donor liver transplantation, and the possible mechanism might be partially attributed to the downregulation of endothelin-1.</p>

Tooth enamel electron spin resonance dosimetry of people living in the area with lime tobacco custom / 中华放射医学与防护杂志

Objective To study the effect of the custom of long term chewing lime tobacco on human tooth enamel electron spin resonance (ESR) dosimetry. Methods A total of 20 enamel samples from lingual parts of adults teeth collected in Bombay, India were obtained by mechanical method. Some enamel samples from Japanese adults were extracted and 10 mixed samples were prepared. Enamel samples were exposed to different doses of 60Co γ-rays several times, and ESR spectra were measured after exposure. Results ESR background signals of 9 Bombay samples were found 1.5-3.3 times higher than those of Japanese mixed samples. The γ-ray dose responses of dosimetric signal with higher background level were a little lower, and the average sensitivity was (0.42 ± 0.03 )mGy, which was close to that of Japanese mixed samples. Conclusions The average level of background signals of Bombay samples was much higher than that of other non-chewing tobacco area, which was possibly caused by tobacco lime, the main component in chewing tobacco productions, and it would help to explore its special influences on ESR, and improve dose reconstruction in accuracy.