Primary Malignant Melanoma of Vagina: A Clinicopathologic Analysis of 6 Cases

Introduction/Objective

Primary malignant melanoma of vagina (PMMV) has a very high rate of recurrence and poor long-term survival. Less than 250 cases are reported in English literature to date, optimal treatments, risk factors, and prognostic predictors for PMMV are still subjects of debate. This study sought to evaluate the clinicopathologic features, initial management, and survival of 6 patients over 7 years follow-up in one institution.

Methods/Case Report

In this study, the clinical and pathologic features of 6 PMMV occurring in patients age 49 to 83 years were evaluated retrospectively. The mean age of the patients was 68.2 years, and all patients were postmenopausal women. At the time of diagnosis, all tumors were limited to the vagina.

Results (if a Case Study enter NA)

Vaginal bleeding, discharge and a tumor mass were the chief complaints. These patients were treated by pelvic exenteration, radical surgery and postoperative chemotherapy and/or radiotherapy. Follow-up was available in all patients ranging from 1 to 7 years. Two patients had metastases in other organs died at 16 and 34 months respectively. Two patients had distant recurrence at 1 to 2 years and are still alive. The other 2 patients have no evidence of disease over 2 years follow-up. Grossly, the tumors were mostly polypoid and ranged from 0.25 to 9.5 cm (mean, 5 cm) in maximum dimension. The depth of invasion ranged from 2.2 to 11 mm. A vertical growth phase was present in all tumors. S-100, HMB-45 and Melan-A were positive in 100% of cases tested. Depth of invasion, mitotic index of tumor cells, tumor size, age, menopausal status, pelvic lymph node metastasis and lymphocytic infiltration show no tendency towards progression-free survival. Patients with positive or indeterminate margin status demonstrated a higher risk of recurrence than did patients with negative margins. And adjuvant therapy was associated with progression-free survival.

Conclusion

In conclusion, PMMV is a rare disease, predominantly seen in women of postmenopausal age, and is associated with a poor prognosis. This study confirms S-100, HMB-45and Melan-A remains the most sensitive marker. Conventional predictors were of no prognostic value. Positive margin and adjuvant therapy were associated with progression-free survival. This report can facilitate the expansion of the phenotypic spectrum of gynecologic melanomas, and contribute to the prevention of misdiagnosis and inadequate treatment of PMMV.

[Follow-up analysis on change of serum total cholesterol concentration in rural residents in Shanxi province]

Objective: To analyze the longitudinal change of serum total cholesterol concentration in 733 rural residents in Shanxi province. Methods: Based on the residents of five rural areas in Shanxi province who participated in China nutrition and health survey in 2002, a follow-up survey was conducted in 2015. Fasting venous blood of the participants was collected and serum TC concentration was tested by cholesterol oxidase method. Results: Of 733 participants, 332 were male and 401 were female. In 2002 baseline survey, the age of the participants was (42.6±9.5) years old, 76.2% of male and 83.8% of female had junior middle school education or below. Proportion of smoking were 65.7% and 1.2%, drinking were 26.8% and 4.0%, obesity were 6.3% and 12.0%, and central obesity were 27.1% and 31.9%, respectively in male and female. The follow-up age of participants in 2015 was (55.8±9.5) years old, proportion of smoking changed to 48.2% and 1.5%, drinking were 49.7% and 3.0%, obesity increased to 11.8% and 18.2% and central obesity increased to 41.6% and 53.6%, respectively in male and female. The overall serum TC level increased from (3.82±0.89) mmol/L to (4.72±0.97) mmol/L with an average increase of 27.2%, which increased from (3.84±0.94) mmol/L to (4.54±0.93) mmol/L in male with an average increase of 22.7%, and increased from (3.81±0.84) mmol/L to (4.86±0.98) mmol/L in female with an average increase of 30.9%. The serum TC levels in 18-, 30-, 40-, and 50-59 years old group increased from (3.42±0.83), (3.72±0.77), (3.90±0.83) and (4.00±1.03) mmol/L to (4.38±1.01), (4.79±0.92), (4.73±0.99) and (4.76±0.96) mmol/L, with average increase range of 31.4%, 32.1%, 25.2% and 22.6%, respectively. The mean serum TC levels between two years all had statistically significant difference among groups of gender, age, education, marital status, family history of cardiovascular disease, smoking, drinking, BMI and waist circumference after paired t-test and ANOVA analysis (P<0.01). Conclusion: The longitudinal serum TC level of rural residents in Shanxi province increased rapidly.

Arotinoid trometamol inhibits arsenic trioxide-stimulated keratinocyte proliferation via the Wnt, Shh, and bone morphogenetic protein signaling pathways

Arsenic acts as a human carcinogen and contributes to skin cancer via mechanisms that remain largely unknown. Recent evidence implicates the perturbation of Wnt, Shh and BMP signals as a potential mechanism. We initiated studies to examine gene expression changes in these signaling pathways. Meanwhile, the antagonistic effect of retinoic acid was explored. In this study, HaCaT and NHEK cells were treated with arsenic trioxide (As2O3) alone or in combination with arotinoid trometamol (retinoic acid receptor agonist). Flow cytometric analysis, PCR array and Western blot were used to determine the potential mechanism and signaling pathways associated with arsenic carcinogenesis. The results showed that low concentration As2O3 could stimulate keratinocyte proliferation, and arotinoid trometamol inhibited the process via regulating the expression of about 20 genes. These genes included components of Wnt signaling (CSNK1A1L, CTNNB1, SFRP1, Wnt10B, Wnt11, Wnt16, Wnt5A, Wnt8A), Shh signaling (C6orf138, HHIP, PTCHD1) and BMP signaling pathway (BMP2, BMP7). The changes of some differentially expressed genes of these signaling pathways in As2O3 treatment group were counteracted by the subsequent arotinoid trometamol treatment. Our data suggest that dysregulation and cross-talk of Wnt, Shh and BMP signals play great roles in the process of arsenic-induced carcinogenesis, which could be antagonized by arotinoid trometamol.

[Characterization analysis of gM, gL genes of varicella zoster virus in six provinces of China]

Objective: To analyze the genetic characterization of glycoprotein M(gM.),glycoprotein L(gL) of varicella zoster virus. Methods: According to the program of "Ministry of Science and Technology of China" , Based on the 12 suspected VZV patients monitored in Beijing (1 case), Shanghai (5 cases), Jilin (2 cases), Qinghai (1 case), Guangdong (2 case) and Sichuan (case) in 2007-2015. A total of 12 Vesicle fluid and throat swab samples were collected. Positive samples were identified by Agarose gel electrophoresis and two glycoprotein genes were amplified by polymerase chain reaction (PCR). Nucleotide sequences were determined and analyzed by PCR amplification of VZV positive specimens V-OKA-BK of the domestic varicella attenuated live vaccine and the Varilrix-1 of the imported attenuated live vaccine. Nucleotide sequences of VZV positive specimens, vaccine strains (V-OKA-BK, varilrix-1) and GenBank foreign wild strains (41 strains), parent strains (P-oka), vaccine strains (V-oka, Varilrix, Varivax) were compared using BioEdit and MEGA 5.0. Results: 12 specimens were VZV positive. Compared with the vaccine strains and the parent strains, the GM gene of 1 positive specimen had radical mutation at 86686 sites, which resulted in amino acid mutation, 5 positive specimens had base mutation at 87844 sites, and 30 strains of foreign wild strains had the same variation at 87 844 sites. 1 positive specimens of gL gene in 101245 sites had base mutation, and led to amino acid mutation, 6 positive specimens at 101624, 101625, 101626 sites had base of loss and the foreign wild strains in these 3 sites had the same variation. Compared with the vaccine strains, the nucleotide and amino acid homology of gM of 12 VZV positive specimens were 99.2%-100% and 98.2%-100%, respectively, and gL of those were 99.3%-100% and 98.6%-100%, respectively. Compared with 41 strains of foreign wild strains, homology of gM's nucleotides and amino acid were 99.3%-100% and 98.5%-100%, respectively; 99.1%-100% and 98.6%-100% for gL. The results of phylogenetic analysis showed that 7 VZV positive samples were on the same branch with 4 vaccine strains and p-oka strain. Based on gL, 12 VZV positive samples were on the same branch as the vaccine strains and p-oka strain. Conclusion: This study demonstrates that the genes of gM, gL are highly conserved and remain stable immunogen, which may be involved in the attenuation of VZV and need to be further researched.

[Association of PD-1, TIM-3 and TREM-1 single nucleotide polymorphisms with pulmonary tuberculosis susceptibility]

Objective: To investigate the association of programmed cell death 1(PD-1), T cell immunoglobulin mucin 3 (TIM-3) and triggering receptor expressed on myeloid cells-1 (TREM-1) genes polymorphisms with pulmonary tuberculosis susceptibility. Methods: In this case-control study, peripheral venous blood of 100 pulmonary tuberculosis patients (pulmonary tuberculosis group) in the Jintan People's Hospital of Changzhou and of community physical examination volunteers (health control group) was collected from Mar 2015 to Sep 2016. A total of 66 single nucleotide polymorphisms (SNP) in PD-1, TIM-3 and TREM1 sequences were selected and SNP genotype and allele frequency were analyzed using the next-generation sequencing technology. Association of these SNP with pulmonary tuberculosis susceptibility was investigated using linkage disequilibrium (LD) analysis and genetic models. Results: Among these 66 SNP, 24 SNP with Hardy-Weinberg equilibrium P (HWE-P) value <0.001 or minimum allele frequency (MAF) <0.05 were kicked out. The remaining 42 SNP were analyzed with LD analysis and genetic models. There was no significant difference in genotype frequencies between pulmonary tuberculosis group and health control group (all P>0.05). Five SNP (rs41435650, rs28539662, rs13023138, rs75565781, rs36084323) in PD-1 were identified in a significant haplotype (TACGC) between pulmonary tuberculosis group and health control group (P=0.014). Among these haplotypes, strong LD was observed between rs28539662 and rs75565781 (r(2)=0.871), as well as rs36084323 (r(2)=0.864). Rs75565781 showed highest correlation with rs36084323 (r(2)=0.966). Conclusion: These SNP in PD-1, TIM-3 and TREM-1 genes are not associated with the susceptibility of pulmonary tuberculosis.

[Association between blood pressure related dietary patterns and identified cognitive performance in the elderly Chinese-a study by reduced rank regression method]

Objective: To study the association between blood pressure related dietary pattern and cognitive impairment in the elderly. Methods: In 2015, all participants who were aged ≥60 and participated in the Nutrition and Chronic disease family cohort were involved in the study. Information on demographic variables, lifestyle and health status was collected. Cognitive performance was assessed by the Mini Mental State Evaluation (MMSE) scale. Blood pressure, height and weight were measured by trained medical personnel and fasting venous blood samples were collected for testing on serum level of triglycerides and total cholesterol. Both SBP and DBP were used as response variables when dietary patterns were identified by reduced rank regression method. Logistic regression models were fit to explore the associations of scores on blood pressure-related dietary pattern and cognitive impairment. Results: Two blood related dietary patterns were identified. The first one was characterized by high consumption of vegetables and less meat, eggs and dessert (Pattern 1), while the second one was with high consumption of meat, soy products, wine and fried foods and less intake of dairy (Pattern 2). Data showed that the Pattern 1 was associated with the risk of cognitive impairment. Comparing with the lowest quartile of score of this dietary pattern, the risk of cognitive impairment in the highest quartile group showed a significant (P<0.01) increase, with OR=1.94 (1.21-3.11) and showing significant (P=0.002) linear trend. However, no significant association was observed (P>0.05) with cognitive impairment in the second dietary pattern. Conclusion: Blood pressure-related dietary pattern was positively associated with cognitive impairment.

Transmissible gastroenteritis virus nsp7 protein localized in the cytoplasm down-regulates interleukin 8 expression in porcine intestinal epithelial cell

Transmissible gastroenteritis virus (TGEV) is an important pathogen in swine that is responsible for substantial economic losses. Previous studies suggest that the TGEV non-structural protein 7 (nsp7) plays an important role in the viral assembly process. However, the subcellular localization and other functions of the TGEV nsp7 protein are still unclear. In this study we have examined the subcellular localization and other functions of TGEV nsp7 protein through analysis of its effects on cell growth, cell cycle progression, interleukin 8 (IL-8) expression, and NF-κB activation. Our results showed that the nsp7 protein is localized in the cytoplasm and has no effect on intestinal epithelial cells (IECs) growth, cell cycle, and cyclin A expression. Further studies showed that TGEV nsp7 protein had no effect on GRP78 expression, could not induce endoplasmic reticulum (ER) stress and activate NF-κB activity. Interestingly, the IECs expressing nsp7 protein secreted lower levels of IL-8 than control cells. This is the first report to demonstrate the subcellular localization and novel functions of TGEV nsp7 protein. These findings provide novel information about the function of the poorly characterized TGEV non-structural protein 7.

Ultra-large non-volatile modulation of magnetic moments in PbZr0.2Ti0.8O3/MgO/La0.7Sr0.3MnO3 heterostructure at room temperature via interfacial polarization mediation

Multiferroic hybrid structures PbZr_0.2Ti_0.8O₃ (PZT)/La_0.7Sr_0.3MnO₃ (LSMO) and PZT/MgO/LSMO were epitaxially deposited on (001) Nb:SrTiO₃ crystals. Crystallinity and ferroelectric domain structures were investigated for the PZT/LSMO heterostructure. Interestingly, relatively high non-volatile magnetoelectric coupling effects were observed in both heterostructures at room temperature. The change of chemical valence for Mn and Ti at the PZT/MgO/LSMO interface may play a dominant role rather than external strain or orbital reconstruction, which lead to a large modulation of the magnetization. Correspondingly, the transport behavior of the PZT/MgO/LSMO heterostructure is investigated to confirm the role of oxygen vacancies motion. Our result indicates that the PZT/MgO/LSMO heterostructure have a promising application for future high-density non-volatile memories.

[Expression and significance of neutrophil surface adhesion molecules in renal transplant recipients with cytomegalovirus infection]

OBJECTIVE

To study the expression and its diagnostic significance of neutrophil surface adhesion molecules including CD11b, CD15 and CD62L after renal transplantation in recipients with cytomegalovirus (CMV) infection.

METHODS

Blood samples were collected from 142 kidney transplant recipients, including 95 males and 47 females, who received allogeneic renal transplantation between September 2009 and January 2015 in 309th Hospital of the PLA. Healthy volunteers (22 males and 9 females) were recruited from physical examination center in 309th Hospital of the PLA from September 2009 to January 2015 as healthy control group. Renal transplant recipients were divided into high active CMV infection group, active CMV infection group and CMV negative control group according to CMV-pp65 antigen detection. Neutrophil surface adhesion molecules CD11b, CD15 and CD62L were detected by flow cytometry and their mean fluorescence intensity compared among the groups. Receiver operating characteristic (ROC) curves of CD11b, CD15 and CD62L in detecting active infection in renal transplant recipients were made.

RESULTS

The mean fluorescence intensity of CD15 in high active CMV infection group(n=17) and active CMV infection group(n=65)were 776.31±89.53 and 554.39±67.89, respectively, with significant differences compared with CMV negative control group (n=60, 334.92±44.69) and healthy control group (n=31, 310.56±39.67) (all P<0.05); the expression proportions of CD11b and CD62L in high active CMV infection group and were 42.31%±6.11% and 40.35%±6.47%, respectively, with significant differences compared with active CMV infection group(62.45%±5.67% and 65.65%±5.33%), CMV negative control group(70.74%±6.55% and 70.37%±6.71%) and healthy control group(72.52%±6.48% and 72.43%±6.51%) (all P<0.05). The optimal cut-off values of CD11b and CD62L in diagnosing active CMV infection group were 56.61% and 44.35%, respectively, with the sensitivity being both 100.00%, the specificity being 76.67% and 58.06% respectively, and the area under the curve (AUC) being 0.851 and 0.628 respectively; the optimal cut-off values of CD11b and CD62L in diagnosing high active CMV infection group were 66.57% and 69.56% respectively, with the sensitivity being 81.54% and 87.69% respectively, the specificity being 100.00% and 98.33% respectively, and the AUC being 1.000 and 0.991 respectively; the optimal cut-off values of mean fluorescence intensity of CD15 in diagnosing high active CMV infection group and active CMV infection group were 542.71 and 408.03 respectively, the sensitivity in the two groups being 100.00% and 98.46% respectively, the specificity being both 100.00%, and the AUC being 1.000 and 0.999 respectively.

CONCLUSIONS

Neutrophils CD15 expression may be up-regulated in renal transplantation recipients with CMV infection, while neutrophils CD11b and CD62L expressions are down-regulated. Such changes in CD15, CD11b and CD62L expression can be used as a basis for laboratory diagnosis of active CMV infection.

Evaluation of staff, patient and foetal radiation doses due to endoscopic retrograde cholangiopancreatography (ERCP) procedures in a pregnant patient

The use of endoscopic retrograde cholangiopancreatography (ERCP) in pregnant patients is not rare. Most studies on the safety and efficacy of these procedures report short- and long-term pregnancy outcomes and but not foetal absorbed doses. This investigation reports on an ERCP procedure for a 40-y-old woman who was 32-34 weeks pregnant. Thermoluminescent dosemeters (TLD 100) were used to measure doses received by the patient and the staff. Additionally, Monte Carlo calculations were performed using a 3D computational phantom representing a 9-month pregnant patient to estimate the foetal absorbed dose. The results show that the spleen of the mother received the largest absorbed dose of 12.18 mGy since it was closer to the source than other internal organs. For the foetus and uterus, the lowest absorbed dose was found to be 0.01 mGy to the foetal brain, while the largest absorbed dose was estimated to be 0.13 mGy to the placenta.

Strain-controlled giant magnetoresistance of a spin valve grown on a flexible substrate

This paper studies the strain-controlled giant magnetoresistance (GMR) change of a top pinned spin valve with the stacking structure of Co₉₀Fe₁₀/Cu/Co₉₀Fe₁₀/IrMn fabricated on a flexible polyethylene terephthalate substrate.

Bortezomib-based treatment of acute antibody-mediated rejection: a case report

Antibody-mediated rejection (AMR) is an important factor affecting survival after renal transplantation. A highly selective proteasome inhibitor, bortezomib, clears activated plasma cells from the body and has important therapeutic effect on AMR. We investigated the effects of bortezomib on AMR in a patient after a second renal transplant. Biopsy confirmed the diagnosis of mixed cellular rejection and AMR. Bortezomib was administered on day 1 (1.3 mg/m(2)), day 4 (1.0 mg/m(2)), and day 8 (1.0 mg/m(2)). On the same days, 250 mg methylprednisolone was administered once, and cyclosporine dose (5 mg·kg(-1)·day(-1)) was reduced by 50%. Oral mycophenolate mofetil and steroid were withdrawn on day 1 of bortezomib treatment. Intermittent double-filtration plasmapheresis was also performed. We monitored parameters, including T lymphocyte subsets, CD139 and CD19 expression, panel reactive antibody (PRA), and serum creatinine concentration. At follow-up 6 months after bortezomib treatment, we observed: 1) serum creatinine stabilized at 130 μM from a peak level of 337 μM; 2) PRA decreased from a maximum of 66.7 to 0%; 3) blood plasma cell percentage rebounded after significantly decreasing following the first dose of bortezomib; 4) in renal allograft biopsy, immunohistochemical staining for C4d shifted from strongly positive to negative, and cellular rejection shifted from type IIA to borderline; and 5) adverse effects such as platelet suppression, hypotension, and grade 3 peripheral neuropathy emerged. Bortezomib effectively treated antibody-mediated renal transplantation rejection in this case study, but clinical trials with large sample sizes are still needed to explore clinical safety and tolerability.

Porcine epidemic diarrhea virus M protein blocks cell cycle progression at S-phase and its subcellular localization in the porcine intestinal epithelial cells

Porcine epidemic diarrhea (PED) caused by virulent strains of porcine epidemic diarrhea virus (PEDV) is a highly contagious enteric disease of swine characterized by severe enteritis, vomiting, and watery diarrhea. This study investigates the subcellular localization and function of PEDV M protein through examination of its effects on cell growth, cell cycle progression, and interleukin 8 (IL-8) expression. Our results revealed that the PEDV M protein is localized throughout the cytoplasm. The M protein altered swine intestinal epithelial cell line (IEC) growth and induced cell cycle arrest at the S-phase via the cyclin A pathway. The S-phase arrest is associated with a decrease in level of cyclin A. Furthermore, our results revealed that the M protein of PEDV does not induce endoplasmic reticulum (ER) stress and does not activate NF-κB which is responsible for IL-8 and Bcl-2 expression. This is the first report to demonstrate that the PEDV M protein is localized in the whole cell and induces cell cycle arrest at the S-phase. This study provides novel findings in the function of M proteins of PEDV.

Meta-analysis demonstrates association between Arg72Pro polymorphism in the P53 gene and susceptibility to keloids in the Chinese population

Although there is evidence suggesting genetic susceptibility for keloids, studies investigating the association between Arg72Pro polymorphism in the P53 gene and tendency to form keloids have given variable results. We made a meta-analysis of the effects of P53 Arg72Pro polymorphism on keloid risk in the Chinese population by conducting searches of the published literature in Pubmed, Embase, CBMdisc, and CNKI databases up to June 2011. Six studies were included in the meta-analysis, with a total of 359 keloid cases and 493 healthy controls. Meta-analysis results, respectively in the PCR-reverse dot blot and PCR-RFLP subgroups, showed significant associations between P53 Arg72Pro polymorphism and susceptibility to keloid in the comparisons of Pro allele vs Arg allele (odds ratio (OR) = 2.29, 95% confidence interval (CI) = 1.45-3.60; OR = 0.74, 95%CI = 0.56-0.98); Pro/Pro vs Pro/Arg + Arg/Arg (OR = 2.91, 95%CI = 1.88-4.53; OR = 0.54, 95%CI = 0.32-0.92); Pro/Pro vs Arg/Arg (OR = 2.79, 95%CI = 1.54-5.06; OR = 0.51, 95%CI = 0.28-0.92); Pro/Pro vs Pro/Arg (OR = 2.85, 95%CI = 1.75-4.63; OR = 0.57, 95%CI = 0.32-0.99). We conclude that the Pro allele of P53 Arg72Pro polymorphism is a risk factor for keloids in the Chinese population.

Electrically generated unidirectional surface plasmon source

We experimentally demonstrated an electrically excited surface plasmon source, which was fulfilled in a silver coated light emitting diode (LED) with well-designed gratings. With a DC current supply, surface plasmon polariton (SPP) waves were generated directly from the illuminations of the LED via the grating coupler. By adjusting the grating to a tilted one, a unidirectional SPP beam was successfully attained with a high extinction ratio (ER~10) and an improved launching efficiency. Detailed analyses show that this electrically generated unidirectional SPP has a considerable long propagation distance (~14 μm), allowing for further manipulations in plasmonic integrations and sensors.

Immunogenicity of the envelope GP3 protein of porcine reproductive and respiratory syndrome virus displayed on baculovirus

Porcine reproductive and respiratory syndrome virus (PRRSV) has been recognized as one of the most important pathogens of pigs throughout the world. The minor envelope protein GP3 of PRRSV plays an important role in clearing of the virus infection and protecting the animals. In this study, a recombinant baculovirus (BacSC-GP3) expressing His6-tagged GP3 with the transmembrane (TM) and cytoplasmic (CT) domains of envelope protein gp64 was constructed and its immunogenicity was evaluated in mouse and piglet models. The His6-tagged GP3 was successfully displayed on the surface of virions as well as virus-infected Sf-9 cells. The animals immunized with BacSC-GP3 gave a slightly higher (piglets) up to a markedly higher (mice) humoral and lymphocyte proliferation responses than those that received a commercial killed vaccine. This is the first study on the immunogenicity of recombinant GP3-baculovirus, which indicates that the latter can represent an alternative strategy for developing a more effective PRRSV vaccine.

Disorder effect on the transport properties of graphene quantum well structures

We study the disorder effect on the transport properties of graphene quantum well structures using a phenomenological statistical model. By adopting the transfer matrix method combined with a Monte Carlo averaging procedure, we observe transitions from ballistic transport to the diffusive limit. It is found that the transmission probability of incident electrons is sensitive to the disorder effect. The significance of the disorder effect depends on the incident angle of the electrons. For normal incidence, the perfect transmission due to the Klein tunneling remains robust against the disorder effect. For tilted incidence, the transmission possibility can be suppressed. In particular, we found that the transmission probability for electrons with a very small angle, i.e. the wavevector along the transport direction is zero in the barrier, can be greatly suppressed. As a result, abrupt dips at these wavevectors emerge in the transmission spectrum.

The development, validation and application of a multi-detector CT (MDCT) scanner model for assessing organ doses to the pregnant patient and the fetus using Monte Carlo simulations

The latest multiple-detector technologies have further increased the popularity of x-ray CT as a diagnostic imaging modality. There is a continuing need to assess the potential radiation risk associated with such rapidly evolving multi-detector CT (MDCT) modalities and scanning protocols. This need can be met by the use of CT source models that are integrated with patient computational phantoms for organ dose calculations. Based on this purpose, this work developed and validated an MDCT scanner using the Monte Carlo method, and meanwhile the pregnant patient phantoms were integrated into the MDCT scanner model for assessment of the dose to the fetus as well as doses to the organs or tissues of the pregnant patient phantom. A Monte Carlo code, MCNPX, was used to simulate the x-ray source including the energy spectrum, filter and scan trajectory. Detailed CT scanner components were specified using an iterative trial-and-error procedure for a GE LightSpeed CT scanner. The scanner model was validated by comparing simulated results against measured CTDI values and dose profiles reported in the literature. The source movement along the helical trajectory was simulated using the pitch of 0.9375 and 1.375, respectively. The validated scanner model was then integrated with phantoms of a pregnant patient in three different gestational periods to calculate organ doses. It was found that the dose to the fetus of the 3 month pregnant patient phantom was 0.13 mGy/100 mAs and 0.57 mGy/100 mAs from the chest and kidney scan, respectively. For the chest scan of the 6 month patient phantom and the 9 month patient phantom, the fetal doses were 0.21 mGy/100 mAs and 0.26 mGy/100 mAs, respectively. The paper also discusses how these fetal dose values can be used to evaluate imaging procedures and to assess risk using recommendations of the report from AAPM Task Group 36. This work demonstrates the ability of modeling and validating an MDCT scanner by the Monte Carlo method, as well as assessing fetal and organ doses by combining the MDCT scanner model and the pregnant patient phantom.

HLA-A*1136 and HLA-A*1138 were identified by polymerase chain reaction sequence-based typing in Chinese individuals

Two human leukocyte antigen (HLA)-A*11 variant alleles were identified in Chinese individuals. HLA-A*1136 shows only one nucleotide difference from A*110101 in exon 3 at position 368, resulting in an amino acid change from His to Cys at codon 99. HLA-A*1138 has two nucleotides change at positions 570 and 571 compared with A*110201, resulting in amino acids change from Glu to Asp at codon 166 and Trp to Gly at codon 167.

A novel HLA-B*15 allele, B*9534, identified by sequence-based typing in the Chinese population

We report here the identification of a novel human leukocyte antigen-B*9534 allele that was detected by polymerase chain reaction sequence-based typing.

Identification of a novel allele HLA-A*9208 by sequence-based typing

A novel HLA-A*9208 allele was identified in a Chinese individual by polymerase chain reaction sequence-based typing.

Pulse optimization for Raman spectroscopy with cross-correlation frequency resolved optical gating

We propose to employ the technique of femtosecond pulse shaping for improving the performance of the recently suggested method of complete characterization of molecular vibrations, in which both the amplitude and phase of the laser induced vibrational coherence are detected with high resolution. The amplitude-phase information is retrieved from the cross-correlation frequency resolved optical gating of Raman modes. By creating rich interference pattern in the measured two-dimensional spectrogram of coherent anti-Stokes Raman scattering we enhance the accuracy of the retrieved spectral and temporal response and increase the robustness of the method against noise.

X-ray imaging optimization using virtual phantoms and computerized observer modelling

This study develops and demonstrates a realistic x-ray imaging simulator with computerized observers to maximize lesion detectability and minimize patient exposure. A software package, ViPRIS, incorporating two computational patient phantoms, has been developed for simulating x-ray radiographic images. A tomographic phantom, VIP-Man, constructed from Visible Human anatomical colour images is used to simulate the scattered portion using the ESGnrc Monte Carlo code. The primary portion of an x-ray image is simulated using the projection ray-tracing method through the Visible Human CT data set. To produce a realistic image, the software simulates quantum noise, blurring effects, lesions, detector absorption efficiency and other imaging artefacts. The primary and scattered portions of an x-ray chest image are combined to form a final image for computerized observer studies and image quality analysis. Absorbed doses in organs and tissues of the segmented VIP-Man phantom were also obtained from the Monte Carlo simulations. Approximately 25,000 simulated images and 2,500,000 data files were analysed using computerized observers. Hotelling and Laguerre-Gauss Hotelling observers are used to perform various lesion detection tasks. Several model observer tasks were used including SKE/BKE, MAFC and SKEV. The energy levels and fluence at the minimum dose required to detect a small lesion were determined with respect to lesion size, location and system parameters.

Specific absorbed fractions for internal photon emitters calculated for a tomographic model of a pregnant woman

Specific absorbed fractions are essential for calculation of radiation dose from internal emitters. Existing specific absorbed fractions for pregnant women were calculated using the stylized models; in this work, a partial-body tomographic model for a pregnant woman was constructed from a rare set of CT images. Based on this tomographic model, the Monte Carlo code, EGS4-VLSI, was used to derive specific absorbed fractions. Monoenergetic, isotropic photon emitters from 15 keV to 4 MeV were distributed in different source organs, and doses were calculated to many target regions in the body. Even though the results showed general agreement with previous studies for higher energies, significant differences were also found, especially for lower energies. The main reasons for the differences are due to the variation of mass, geometry, and organ distances, and they demonstrate the influence of more realistic body models on dose calculations.

Fluence-to-dose conversion coefficients for monoenergetic proton beams based on the VIP-Man anatomical model

A new set of fluence-to-absorbed dose and fluence-to-effective dose conversion coefficients has been calculated for high-energy protons using the whole-body anatomical model VIP-Man, which was developed from the high-resolution transverse colour photographic images of the National Library of Medicine's Visible Human Project. For 10 monoenergetic proton beams between 20 and 10,000 MeV, organ dose calculations were performed using the Monte Carlo code MCNPX under six different irradiation geometries: anterior-posterior, posterior-anterior, left lateral, right lateral, isotropic and rotational. The absorbed dose results for 24 major organs of VIP-Man are presented and compared with those based on mathematical phantoms reported in the literature. The discrepancies (generally within 40%) in organ dose and effective dose estimates are attributed to the use of different transport models employed by different Monte Carlo codes.

Calculations of specific absorbed fractions of the gastrointestinal tract using a realistic whole body tomographic model

Assessment of organ doses from internally deposited radionuclides involves the use of predetermined specific absorbed fractions (SAFs). Many tabulations of SAFs have been derived from Monte Carlo transport simulations using stylized computational models that are not fully realistic of human internal organ anatomy. This paper presents the results of a study to calculate SAFs in the gastrointestinal (GI) tract using a recently developed tomographic model VIP-Man and the EGS4 Monte Carlo radiation transport code. Results show that, for some energies and source-target combinations, considerable discrepancies exist between these results and those from earlier studies, suggesting a need to evaluate existing data carefully by comparison with realistic models.

Estimating the depth of embedded contaminants from in-situ gamma spectroscopic measurements

The depth of radiological contamination is information required for decontamination and decommissioning of nuclear facilities. This paper proposes and tests a simple technique for measuring the depth of contamination. The method uses measurements with an HPGe detector at two distances (or heights) from the surface on the same side of the medium. The ratio of the photopeak areas easily can be used to yield the depth of an embedded source. The calculational algorithm was verified by simulations with the MCNP4C code and laboratory experiments for a point source and other special sources. Predictions of the depth for shallowly embedded sources have relatively large uncertainties (approximately 18%) but improve as depth increases. This technique provides a very easy way for a user to quickly estimate the depth of the subsurface contamination on site.

Fluence-to-dose conversion coefficients based on the VIP-Man anatomical model and MCNPX code for monoenergetic neutrons above 20 MeV

A new set of fluence-to-absorbed dose and fluence-to-effective dose conversion coefficients has been calculated for high-energy neutrons using a whole-body anatomical model, VIP-Man, developed from the high-resolution transversal color photographic images of the National Library of Medicine's Visible Human Project. Organ dose calculations were performed using the Monte Carlo code MCNPX for 20 monoenergetic neutron beams between 20 MeV and 10,000 MeV under 6 different irradiation geometries: anterior-posterior, posterior-anterior, left lateral, right lateral, isotropic, and rotational. For neutron Monte Carlo calculations, results based on an image-based whole-body model were not available in the literature. The absorbed dose results for 24 major organs of VIP-Man are presented in the form of tables and selected figures that compare with those based on simplified mathematical phantoms reported in the literature. VIP-Man yields up to 40% larger values of effective dose and many organ doses, thus suggesting that the results reported in the past may not be conservative.

Organ dose conversion coefficients for 0.1-10 MeV electrons calculated for the VIP-Man tomographic model

A whole-body tomographic model, called VIP-Man, was recently developed at Rensselaer Polytechnic Institute from the high-resolution color photographic images of the National Library of Medicine's Visible Human Project. An EGS4-based Monte Carlo user code, named EGS4-VLSI, was developed to efficiently transport electrons using the large image data set for VIP-Man. VIP-Man has been used to calculate doses for neutrons and photons. This paper presents a new set of fluence-to-absorbed-dose conversion coefficients for monoenergetic electron beams between 100 keV and 10 MeV for VIP-Man. Irradiation conditions include anterior-posterior, posterior-anterior, right lateral, left lateral, rotational, and isotropic source geometries. Comparisons between organ doses from VIP-Man, which is taller and heavier than the Reference Man, and existing data from mathematical models show significant discrepancies. It appears that even slight differences between body models can cause dramatic dosimetric deviations for low penetrating electron irradiation. This suggests that a single standard body model may poorly represent a large population and may not be acceptable for electron dosimetry.

Conversion coefficients based on the VIP-Man anatomical model and EGS4

A new set of conversion coefficients from kerma free-in-air to absorbed dose and kerma free-in-air to "effective VIP-Man dose" has been calculated for external monoenergetic photon beams from 10 keV to 10 MeV using an image-based whole-body anatomical model. This model, called VIP-Man, was recently developed at Rensselaer from the high-resolution color images of the National Library of Medicine's Visible Human Project. An EGS4-based Monte Carlo user code, named EGS4-VLSI, was developed to efficiently process the extremely large image data in VIP-Man. Irradiation conditions include anterior-posterior, posterior-anterior, right lateral, left lateral, rotational, and isotropic geometries. Conversion coefficients from this study are compared with those obtained from two mathematical models, ADAM and EVA. "Effective VIP-Man doses" differ from the previously reported effective dose results by 10%-50% for photons between 100 keV and 10 MeV. Discrepancies are more significant at lower energies and for individual organ doses. Since VIP-Man is a realistic model that contains several tissues that were not previously defined well (or not available) in other models, the reported results offer an opportunity to improve the existing dosimetric data and the mathematical models.

Specific absorbed fractions from the image-based VIP-Man body model and EGS4-VLSI Monte Carlo code: internal electron emitters

VIP-Man is a whole-body anatomical model newly developed at Rensselaer from the high-resolution colour images of the National Library of Medicine's Visible Human Project. This paper summarizes the use of VIP-Man and the Monte Carlo method to calculate specific absorbed fractions from internal electron emitters. A specially designed EGS4 user code, named EGS4-VLSI, was developed to use the extremely large number of image data contained in the VIP-Man. Monoenergetic and isotropic electron emitters with energies from 100 keV to 4 MeV are considered to be uniformly distributed in 26 organs. This paper presents, for the first time, results of internal electron exposures based on a realistic whole-body tomographic model. Because VIP-Man has many organs and tissues that were previously not well defined (or not available) in other models, the efforts at Rensselaer and elsewhere bring an unprecedented opportunity to significantly improve the internal dosimetry.

Effects of des-aspartate-angiotensin I on angiotensin II-induced incorporation of phenylalanine and thymidine in cultured rat cardiomyocytes and aortic smooth muscle cells

Des-aspartate-angiotensin I, a pharmacologically active nine-amino acid angiotensin peptide, and losartan, an AT(1) angiotensin receptor antagonist, but not angiotensin-(1-7), another active angiotensin peptide, completely attenuated the angiotensin II-induced incorporation of [3H]phenylalanine in cultured rat cardiomyocytes. The attenuation by des-aspartate-angiotensin I but not that of losartan was inhibited by indomethacin. The data support an earlier suggestion that the nonapeptide attenuates cardiac hypertrophy in rats via an indomethacin-sensitive angiotensin AT(1) receptor subtype. In rat aortic smooth muscle cells, both des-aspartate-angiotensin I and angiotensin-(1-7) had no effect on the angiotensin II-induced [3H]phenylalanine incorporation. However, the two peptides significantly attenuated the angiotensin II-induced [3H]thymidine incorporation in the smooth muscle cells. The attenuation by angiotensin-(1-7) but not by des-aspartate-angiotensin I was inhibited by (D-Ala(7))-angiotensin-(1-7), a specific angiotensin-(1-7) antagonist. Des-aspartate-angiotensin I also attenuated FCS-stimulated [3H]thymidine incorporation. This attenuation was inhibited by the peptide angiotensin receptor antagonist, (Sar(1), Ile(8))-angiotensin II, but not by losartan. These data indicate that des-aspartate-angiotensin I and angiotensin-(1-7) do not participate in the process of protein synthesis in vascular smooth muscle cells and that the nonapeptide and heptapeptide act on different non-AT(1) receptors to mediate their anti-hyperplasic action. Although the exact mechanisms of action remain to be elucidated, the findings indicate that des-aspartate-angiotensin I acts as an agonist on angiotensin AT(1) and non-AT(1) receptor subtypes and induces responses that oppose the actions of angiotensin II.

Fluence-to-dose conversion coefficients from monoenergetic neutrons below 20 MeV based on the VIP-man anatomical model

A new set of fluence-to-absorbed dose and fluence-to-effective dose conversion coefficients have been calculated for neutrons below 20 MeV using a whole-body anatomical model, VIP-Man, developed from the high-resolution transverse colour photographic images of the National Library of Medicine's Visible Human Project. Organ dose calculations were performed using the Monte Carlo code MCNP for 20 monoenergetic neutron beams between 1 x 10(-9) MeV and 20 MeV under six different irradiation geometries: anterior-posterior, posterior-anterior, right lateral, left lateral, rotational and isotropic. The absorbed dose for 24 major organs and effective dose results based on the realistic VIP-Man are presented and compared with those based on the simplified MIRD-based phantoms reported in the literature. Effective doses from VIP-Man are not significantly different from earlier results for neutrons in the energy range studied. There are, however, remarkable deviations in organ doses due to the anatomical differences between the image-based and the earlier mathematical models.

Improvement of terahertz imaging with a dynamic subtraction technique

By use of dynamic subtraction it is feasible to adopt phase-sensitive detection with a CCD camera to reduce long-term optical background drift. We report on a two-order improvement of the signal-to-noise ratio. The improved system is used to image terahertz field distribution generated by an optically rectified electro-optic crystal with a modulation depth as small as 10(-4). We also introduce a modified detection geometry that realizes near-field imaging capability with greatly improved spatial resolution.