Gender differences in the incidence and progression of diabetic retinopathy among Japanese patients with type 2 diabetes mellitus: A clinic-based retrospective longitudinal study

A clinic-based retrospective longitudinal study conducted for 5.8 ± 2.5 years, including 383 (M/F 245/138) Japanese patients with type 2 diabetes mellitus showed that females exhibit a significantly higher prevalence of proliferative diabetic retinopathy (DR) at baseline and that female gender is an independent risk factor for the development of DR.     

Changes in cerebral blood flow during steady-state cycling exercise: a study using oxygen-15-labeled water with PET

Cerebral blood flow (CBF) during dynamic exercise has never been examined quantitatively using positron emission tomography (PET). This study investigated changes in CBF that occur over the course of a moderate, steady-state cycling exercise. Global and regional CBF (gCBF and rCBF, respectively) were measured using oxygen-15-labeled water (H₂¹⁵O) and PET in 10 healthy human subjects at rest (Rest), at the onset of exercise (Ex1) and at a later phase in the exercise (Ex2). At Ex1, gCBF was significantly (P<0.01) higher (27.9%) than at Rest, and rCBF was significantly higher than at Rest in the sensorimotor cortex for the bilateral legs (M1_Leg and S1_Leg), supplementary motor area (SMA), cerebellar vermis, cerebellar hemispheres, and left insular cortex, with relative increases ranging from 37.6% to 70.5%. At Ex2, gCBF did not differ from Rest, and rCBF was significantly higher (25.9% to 39.7%) than at Rest in only the M1_Leg, S1_Leg, and vermis. The areas showing increased rCBF at Ex1 were consistent with the central command network and the anatomic pathway for interoceptive stimuli. Our results suggest that CBF increases at Ex1 in parallel with cardiovascular responses then recovers to the resting level as the steady-state exercise continues.     

Strength estimation of a moving 125Iodine source during implantation in brachytherapy: application to linked sources

This study sought to demonstrate the feasibility of estimating the source strength during implantation in brachytherapy. The requirement for measuring the strengths of the linked sources was investigated. The utilized sources were ¹²⁵I with air kerma strengths of 8.38–8.63 U (μGy m² h^–1). Measurements were performed with a plastic scintillator (80 mm × 50 mm × 20 mm in thickness). For a source-to-source distance of 10.5 mm and at source speeds of up to 200 mm s^–1, a counting time of 10 ms and a detector-to-needle distance of 5 mm were found to be the appropriate measurement conditions. The combined standard uncertainty (CSU) with the coverage factor of 1 (k = 1) was ∼15% when using a grid to decrease the interference by the neighboring sources. Without the grid, the CSU (k = 1) was ∼5%, and an 8% overestimation due to the neighboring sources was found to potentially cause additional uncertainty. In order to improve the accuracy in estimating source strength, it is recommended that the measurment conditions should be optimized by considering the tradeoff between the overestimation due to the neighboring sources and the intensity of the measured value, which influences the random error.     

Hepatitis B virus X stimulates redox signaling through activation of ataxia telangiectasia mutated kinase

Hepatitis B virus X (HBX) protein plays a crucial role in carcinogenesis, but its mechanism is unclear. The involvement of ataxia telangiectasia mutated (ATM) kinase in the enhanced redox system was investigated by examining the phosphorylation level of ATM in HBX gene-transfected cells and in transgenic mice following redox system manipulation by treatment with hydrogen peroxide (H₂O₂) or antioxidant. Western blotting and immunostaining showed that phospho-ATM was significantly increased by HBX both in vitro (3.2-fold; p<0.05) and in vivo (4-fold; p<0.05), and this effect was abrogated by antioxidant treatment. The level of PKC-δ in HBX-expressing cells was increased 3.5-fold compared to controls. Nuclear localized NF-E2-related factor 2 (Nrf2) was increased in HBX-expressing cells exposed to H₂O₂, but remained at lower levels after the treatment with rottlerin, KU55933, or caffeine. The levels of anti-oxidant molecules were increased in HBX expressing cells and in transgenic mice, indicating that HBX stimulates the Nrf2-mediated redox system. The levels of intracellular reactive oxygen species (ROS) were significantly increased in HBX-expressing cells treated with hydrogen peroxide in the presence of ATM inhibitor KU55933 or caffeine. Treatment of HBX-expressing cells with KU55933 or caffeine before the exposure to H₂O₂ increased the ratio of cell apoptosis to 33 ± 4% (p<0.05) and 22 ± 4% (p<0.05), respectively. Collectively, HBX stimulates the ATM-mediated PKC-δ/Nrf2 pathway, and maintains the enhanced activity of the redox system. Therefore, manipulating ATM kinase activity might be a useful strategy for treating HBX-induced carcinogenesis.     

Mural vegetation in left ventricular apex caused by Staphylococcus aureus

A 77-year-old male on chronic haemodialysis was admitted for repeated episodes of stroke and a high fever. The patient’s blood culture was positive for Staphylococcus aureus and echocardiogram results revealed moderate mitral valve regurgitation, small masses in the left atrial appendage and a 20-mm mobile, spherical structure attached to the apical cavity of the left ventricle. Surgery was conducted to successfully excise these masses and pathological investigation confirmed the diagnosis of infective endocarditis. The attachment of mobile, spherical vegetation to the apex of the left ventricle is a rare manifestation of infective endocarditis.     

Combination effect of photodynamic and sonodynamic therapy on experimental skin squamous cell carcinoma in C3H/HeN mice

We studied a combination of photodynamic therapy (PDT) and sonodynamic therapy (SDT) for improving tumoricidal effects in a transplantable mouse squamous cell carcinoma (SCC) model. Two sensitizers were utilized: the pheophorbide-a derivative PH-1126, which is a newly developed photosensitizer, and the gallium porphyrin analogue ATX-70, a commonly used sonosensitizer. Mice were injected with either PH-1126 or ATX-70 i.p. at doses of 5 or 10 mg/kg.bw. At 24 (ATX-70) or 36 hr (PH-1126) (time of optimum drug concentration in the tumor) after injection, SCCs underwent laser light irradiation (88 J/cm2 of 575 nm for ATX-70; 44J/cm2 of 650 nm for PH-1126) (PDT), ultrasound irradiation (0.51 W/cm2 at 1.0 MHz for 10 minutes) (SDT), or a combination of the two treatments. The combination of PDT and SDT using either PH-1126 or ATX-70 as a sensitizer resulted in significantly improved inhibition of tumor growth (92-98%) (additive effect) as compared to either single treatment (27-77%). The combination using PH-1126 resulted in 25% of the treated mice being tumor free at 20 days after treatment. Moreover, the median survival period (from irradiation to death) of PDT + SDT-treated mice (> 120 days) was significantly greater than that in single treatment groups (77-95 days). Histological changes revealed that combination therapy could induce tumor necrosis 2-3 times as deep as in either of the single modalities. The combination of PDT and SDT could be very useful for treatment of non-superficial or nodular tumors.     

Cigarette smoking, alcohol drinking, and oral and pharyngeal cancer mortality in Japan

Objectives:  To prospectively examine the association of cigarette smoking and alcohol drinking with oral and pharyngeal carcinogenesis, we analyzed data from a nation-wide large-scale cohort study in Japan.
Methods:  A total of 34 136 men and 43 711 women aged 40–79 years were included in the study. The Cox proportional hazard model was used to estimate the relative risk (RR) and 95% confidence interval (95% CI) of oral and pharyngeal cancer for smoking and drinking by sex, while adjusting for age, consumption of green tea, preference for salty foods, and consumption of green yellow vegetables.
Results:  Current smokers were found to have a higher risk of death caused by oral and pharyngeal cancer compared with non-smokers in both sexes: the RR was 2.6 (95% CI: 1.0–6.7) in men and 8.2 (95% CI: 2.1–32.1) in women. Men who drank more than 46 g ethanol per day had an approximately threefold increased risk of oral and pharyngeal cancer. Simultaneous exposure to both factors was significantly associated with an elevated risk of oral and pharyngeal cancer (RR: 3.3, 95% CI: 1.1–9.6).
Conclusions:  The result supports the carcinogenic effect of cigarette smoking and alcohol drinking on the oral cavity and pharynx.