Monitoring therapeutic responses of primary bone tumors by diffusion-weighted image: initial results

The purpose of our study was to investigate whether quantitative diffusion-weighted images (DWI) were useful for monitoring the therapeutic response of primary bone tumors. We encountered 18 osteogenic and Ewing sarcomas. Magnetic resonance (MR) images were performed in all patients before and after therapy. We measured the apparent diffusion coefficient (ADC) values, contrast-to-noise ratio (CNR), and tumor volume of the bone tumors pre- and posttreatment. We determined change in ADC value, change in CNR on T2-weighted images (T2WI), change in CNR on gadopentetate dimeglumine (Gd)-T1-weighted images (Gd-T1WI), and change in tumor volume. The bone tumors were divided into two groups: group A was comprised of tumors with less than 90% necrosis after treatment and group B of tumors at least with 90%. Changes in ADC value, tumor volume, and CNR were compared between the groups. Change in the ADC value was statistically greater in group B than that in the group A (p=0.003). There was no significant difference in the changes in CNR on T2WI (p=0.683), in CNR on Gd-T1WI (p=0.763), and tumor volume (p=0.065). The ADC value on DWI is a promising tool for monitoring the therapeutic response of primary bone sarcomas.     

A computer-simulated liver phantom (virtual liver phantom) for multidetector computed tomography evaluation

Objective The purpose of study was to develop a computer-simulated liver phantom for hepatic CT studies. A computer-simulated liver phantom was mathematically constructed on a computer workstation.Materials and methods The computer-simulated phantom was calibrated using real CT images acquired by an actual four-detector CT. We added an inhomogeneous texture to the simulated liver by referring to CT images of chronically damaged human livers. The mean CT number of the simulated liver was 60 HU and we added numerous 5-to 10-mm structures with 60±10 HU/mm. To mimic liver tumors we added nodules measuring 8, 10, and 12 mm in diameter with CT numbers of 60±10, 60±15, and 60±20 HU. Five radiologists visually evaluated similarity of the texture of the computer-simulated liver phantom and a real human liver to confirm the appropriateness of the virtual liver images using a five-point scale.Results The total score was 44 in two radiologists, and 42, 41, and 39 in one radiologist each. They evaluated that the textures of virtual liver were comparable to those of human liver.Conclusions Our computer-simulated liver phantom is a promising tool for the evaluation of the image quality and diagnostic performance of hepatic CT imaging.     

Acute and late genitourinary toxicity of conformal radiotherapy for prostate cancer

Purpose The aim of this study was to identify predictive factors for genitourinary (GU) toxicity in prostate cancer patients who underwent conformal radiotherapy (CRT). Materials and methods In this study we analyzed 154 cases of T1-3N0M0 prostate adenocarcinoma and evaluated the occurrence rate of acute and late GU toxicity and the duration of acute toxicity according to clinical parameters: age, transurethral resection of the prostate prior to CRT, hormone therapy, CRT dose, length of planning target volume (PTV). Results Altogether, 41% of the patients developed grade 2 or higher acute GU toxicity. Longer PTV was significantly associated with a higher incidence of acute GU toxicity (>7 cm, 53%; ≤7 cm, 31%; P = 0.003), and hormone therapy prolonged the duration of the toxicity (P = 0.007). Grade 1 or higher late GU toxicity developed in 23% of the patients, and the 2-year late GU toxicity-free survival rate was 79%. Acute GU toxicity was significantly associated with the late GU toxicity-free survival rate (grade 0–1, 88.7%; grade 2–4, 73.2%; P = 0.0007). Conclusion The length of PTV and hormone therapy were predictive factors for acute GU toxicity. Furthermore, acute GU toxicity was the most important predictive factor for late GU toxicity.     

Neurodevelopmental outcome in children with intraventricular hemorrhage

To clarify the neurodevelopmental outcome in children with intraventricular hemorrhage, a follow-up study was performed for a consecutive group of 335 subjects in one tertiary center born between 1981 and 1999. Their mean gestation and birth weight were 28.1 weeks and 1162.2 gm, respectively. The follow-up period ranged from 3 to 20 years (mean: 7.5 years). The neurodevelopmental outcomes were normal in 188 (56.1%), cerebral palsy in 75 (22.4%), mental retardation in 34 (10.2%), and borderline intelligence in 38 (11.3%). There were statistically significant differences in the outcomes among the groups with different grades of intraventricular hemorrhage. Approximately 70% of the children with intraventricular hemorrhage grade 1 were normal, whereas only 15.4% of the children with intraventricular hemorrhage grade 4 were normal. Cerebral palsy was associated with as high as 71.2% in the patients with intraventricular hemorrhage grade 4. The overall incidence of epilepsy was 39/335 (11.6%). This study has not demonstrated clear improvement of the outcome in children with intraventricular hemorrhage between the 1980s and 1990s.     

Intrathecal injection of epidermal growth factor and fibroblast growth factor 2 promotes proliferation of neural precursor cells in the spinal cords of mice with mutant human SOD1 gene

We investigated three steps of neural precursor cell activation--proliferation, migration, and differentiation--in amyotrophic lateral sclerosis spinal cord treated with intrathecal infusion of epidermal growth factor (EGF) and fibroblast growth factor 2 (FGF2) into the lumbar spinal cord region of normal and symptomatic transgenic (Tg) mice with a mutant human Cu/Zn superoxide dismutase (SOD1) gene. We observed that 5-bromodeoxyuridine (BrdU) + nestin double-labeled neural precursor cells increased in the spinal cords of Tg mice compared with non-Tg mice, with a much greater increase produced by EGF and FGF2 treatment. The number of BrdU + nestin double-labeled cells was larger than that of BrdU + ionized calcium-binding adapter molecule-1 (Iba1), BrdU + glial fibrillary acidic protein (GFAP), or BrdU + highly polysialylated neural cell adhesion molecule (PSA-NCAM) double-labeled cells, but none expressed neuronal nuclear antigen (NeuN). On further analysis of the gray matter of Tg mice, the number of BrdU + nestin and BrdU + PSA-NCAM double-labeled cells increased more in the ventral horns than the dorsal horns, which was again greatly enhanced by EGF and FGF2 treatment. Because neural precursor cells reside close to the ependyma of central canal, the present study suggests that proliferation and migration of neural precursor cells to the ventral horns is greatly activated in symptomatic Tg mice and is further enhanced by EGF and FGF2 treatment and, furthermore, that the neural precursor cells preferentially differentiate into neuronal precursor cells instead of astrocytes in Tg mice with EGF and FGF2 treatment.     

Association of ambient air pollution and meteorological factors with primary care visits at night due to asthma attack

Aim

The association of outdoor air pollution and meteorological elements with primary care visits at night due to asthma attack was studied.

Methods

A case–crossover study was conducted in a primary care clinic in Himeji City, Japan. The subjects were 956 children aged 0–14 years who visited the clinic with an asthma attack between the hours of 9 p.m. and 6 a.m. Daily concentrations of particulate matter, ozone, nitrogen dioxide, and a number of meteorological elements were measured, and a conditional logistic regression model was used to estimate odds ratios (ORs) of primary care visits per unit increment of air pollutants or meteorological elements. The analyses took into consideration the effects of seasonality.

Results

Of the 956 children, 73 (7.6 %) were aged <2 years and 417 (43.6 %) were aged 2–5 years. No association between daily ozone levels and primary care visits due to asthma attack at night in the spring or summer was found. An inverse relation between suspended particulate matter and primary care visits due to asthma attack was detected in the winter. ORs in the summer per degree increment in daily mean temperature was 1.31 [95 % confidential interval (CI) 1.09–1.56], and ORs in the autumn per hourly increment in daily hours of sunshine was 0.94 (95 % CI 0.90–0.99).

Conclusion

The findings of our study fail to support any association between daily mean concentration of air pollutant and primary care visits at night. However, we did find evidence indicating that certain meteorological elements may be associated with primary care visits