Sex and body mass index impact on digit circumference for Leeds Dactylitis Index calculation.

OBJECTIVES: To estimate digit circumference and the impact of sex and body mass index (BMI) for the calculation of the Leeds Dactylitis Index (LDI) in psoriatic arthritis (PsA) patients with bilateral dactylitis. METHODS: Digit circumference of the hands and the foot were measured with a dactylometer and were studied according to sex and BMI (divided in 4 weight categories) in healthy Portuguese subjects, using Student's t-test and One-way ANOVA, respectively. The effect size of sex and BMI were calculated using Cohen's d test and Eta squared, respectively. Multiple linear regression was used to calculate the effect of sex and BMI, as well as their interaction, to create a formula to predict digit circumference. RESULTS: Fifty-nine participants (33 women, 26 men) with a mean BMI of 24.8 were included. Men's mean digit circumferences were statistically higher than those of women (p<0.001), with a large sex effect size in most of the digits. Differences in the mean circumference between the four BMI categories were statistically significant (p<0.05) for all digits, with a large BMI effect size. Sex and BMI were independent variables to predict mean digit circumference (p<0.001). A new tool (based on regression analysis) allowing to estimate the circumference of digits for males and females of different BMIs is presented. CONCLUSIONS: Our data allows the calculation of digit circumference for males and females of different BMIs in the Portuguese population; and shows that BMI influences digital circumference supporting BMI inclusion in LDI references tables.

Low doses of ionizing radiation activate endothelial cells and induce angiogenesis in peritumoral tissues.

PURPOSE: During radiotherapy the peritumoral tissues are daily exposed to subtherapeutic doses of ionizing radiation. Herein, the biological and molecular effects of doses lower than 0.8 Gy per fraction (LDIR), previously described as angiogenesis inducers, were assessed in human peritumoral tissues. MATERIAL AND METHODS: Paired biopsies of preperitoneal adipose tissue were surgically collected from 16 patients diagnosed with locally advanced rectal cancer who underwent neo-adjuvant radiotherapy. One of the biopsies is located in the vicinity of the region where the tumor received the prescribed dose of radiation, and thus exposed to LDIR; the other specimen, outside all beam apertures, was used as an internal calibrator (IC). Microvessel density (MDV) was quantified by immunohistochemistry and the expression of angiogenic, pro-inflammatory, adhesion and oxidative stress genes was assessed by quantitative RT-PCR using exclusively endothelial cells (ECs) isolated by laser capture microdissection microscopy. RESULTS: LDIR activated peritumoral ECs by significantly up-regulating the expression of several pro-angiogenic genes such as VEGFR1, VEGFR2, ANGPT2, TGFB2, VWF, FGF2, HGF and PDGFC and down-regulating the pro-inflammatory IL8 marker. Accordingly, the MVD was significantly increased in peritumoral tissues exposed to LDIR, compared to the IC. The patients that yielded a larger pro-angiogenic response, also showed the highest MVD. CONCLUSIONS: LDIR activate ECs in peritumoral tissues that are associated with increased MVD. Although the technological advances in radiotherapy have contributed to reduce the damage to healthy tissues over the past years, the anatomical regions receiving LDIR should be taken into account in the treatment plan report for patient follow-up and in future studies to correlate these doses with tumor dissemination.

Low doses of ionizing radiation activate endothelial cells and induce angiogenesis in peritumoral tissues.

PURPOSE: During radiotherapy the peritumoral tissues are daily exposed to subtherapeutic doses of ionizing radiation. Herein, the biological and molecular effects of doses lower than 0.8 Gy per fraction (LDIR), previously described as angiogenesis inducers, were assessed in human peritumoral tissues. MATERIAL AND METHODS: Paired biopsies of preperitoneal adipose tissue were surgically collected from 16 patients diagnosed with locally advanced rectal cancer who underwent neo-adjuvant radiotherapy. One of the biopsies is located in the vicinity of the region where the tumor received the prescribed dose of radiation, and thus exposed to LDIR; the other specimen, outside all beam apertures, was used as an internal calibrator (IC). Microvessel density (MDV) was quantified by immunohistochemistry and the expression of several pro-angiogenic genes was assessed by quantitative RT-PCR using exclusively endothelial cells (ECs) isolated by laser capture microdissection microscopy. RESULTS: LDIR activated peritumoral ECs by significantly up-regulating the expression of several pro-angiogenic genes such as VEGFR1, VEGFR2, ANGPT2, TGFB2, VWF, FGF2, HGF and PDGFC. Accordingly, the MVD was significantly increased in peritumoral tissues exposed to LDIR, compared to the IC. The patients that yielded a larger pro-angiogenic response, also showed the highest MVD. CONCLUSIONS: LDIR activate ECs in peritumoral tissues that are associated with increased MVD. Although the technological advances in radiotherapy have contributed to reduce the damage to healthy tissues over the past years, the anatomical regions receiving LDIR should be taken into account in the treatment plan report for patient follow-up and in future studies to correlate these doses with tumor dissemination.