The Usefulness of Readout-Segmented Echo-Planar Imaging (RESOLVE) for Bio-phantom Imaging Using 3-Tesla Clinical MRI

Readout-segmented echo-planar imaging (RESOLVE) is a multi-shot echo-planar imaging (EPI) modality with k-space segmented in the readout direction. We investigated whether RESOLVE decreases the distortion and artifact in the phase direction and increases the signal-to-noise ratio (SNR) in phantoms image taken with 3-tesla (3T) MRI versus conventional EPI. We used a physiological saline phantom and subtraction mapping and observed that RESOLVE’s SNR was higher than EPI’s. Using RESOLVE, the combination of a special-purpose coil and a large-loop coil had a higher SNR compared to using only a head/neck coil. RESOLVE’s image distortioas less than EPI’s. We used a 120 mM polyethylene glycol phantom to examine the phase direction artifact.vThe range where the artifact appeared in the apparent diffusion coefficient (ADC) image was shorter with RESOLVE compared to EPI. We used RESOLVE to take images of a Jurkat cell bio-phantom: the cell-region ADC was 856×10−6mm2/sec and the surrounding physiological saline-region ADC was 2,951×10−6mm2/sec. The combination of RESOLVE and the 3T clinical MRI device reduced image distortion and improved SNR and the identification of accurate ADC values due to the phase direction artifact reduction. This combination is useful for obtaining accurate ADC values of bio-phantoms

High-dose Chemotherapy with Peripheral Blood Stem Cell (PBSCT) Support for Recurrent Breast Cancer

Between May 1995 and June 1999 Seven patients with recurrent breast cancer received high dose chemotherapy (HDCT) with autologous peripheral blood stem cell transplantation (PBSCT) . The HDCT regimen consisted of epirubicin (120-260 mg/m? ), cyclophosphamide (0-4000 mg/body) . Medroxy-progesterone (1200 mg/day) was given more than 2 weeks prior to induction chemotherapy. HDCT with PBSCT support was performed on all patients on schedule. No toxic death by chemotherapy occurred. The clinical response was CR in 3, PR in 3 and NC in one patient. The rate of good clinical re-sponse was 86 %. The mean survival duration after recurrence was 24 months (range10-34) . The mean survival period after HDCT was 12 months (range 8-25) . The durations of efficacy were shorter than had been ex-pected. While this treatment resulted in higher rates of clinical response, the prognosis for patients with metastatic tumor was not improved

In Vitro Assessment of Factors Affecting the Apparent Diffusion Coefficient of Jurkat Cells Using Bio-phantoms

It is well known that many tumor tissues show lower apparent diffusion coefficient (ADC) values, and that several factors are involved in the reduction of ADC values. The aim of this study was to clarify how much each factor contributes to decreases in ADC values. We investigate the roles of cell density, extracellular space, intracellular factors, apoptosis and necrosis in ADC values using bio-phantoms. The ADC values of bio-phantoms, in which Jurkat cells were encapsulated by gellan gum, were measured by a 1.5-Tesla magnetic resonance imaging device with constant diffusion time of 30sec. Heating at 42℃ was used to induce apoptosis while heating at 48℃ was used to induce necrosis. Cell death after heating was evaluated by flow cytometric analysis and electron microscopy. The ADC values of bio-phantoms including non-heated cells decreased linearly with increases in cell density, and showed a steep decline when the distance between cells became less than 3μm. The analysis of ADC values of cells after destruction of cellular structures by sonication suggested that approximately two-thirds of the ADC values of cells originate from their cellular structures. The ADC values of bio-phantoms including necrotic cells increased while those including apoptotic cells decreased. This study quantitatively clarified the role of the cellular factors and the extracellular space in determining the ADC values produced by tumor cells. The intermediate diffusion time of 30msec might be optimal to distinguish between apoptosis and necrosis

The usefulness of colposcopy for evaluation of chemotherapeutic effect on uterine cervical carcinoma

Forty-three patients with atage II squamous cell carcinoma of the uterine cervix were treated with intra-arterial cis-platinum before radical hysterectomy. The dose of cis-platinum was 50mg/㎡ and the infusion was repeated twice at 3-week intervals. In this in investigation, serial colposcopy and biopsies were performed to assess the efficacy of this chemotherapy. On colposcopy, the first change on the surface of the lesion during chemotherapy was a whitish change, followed by a yellowish change. After that, the lasion became less irregular, atypical vessels were less numerous and the surface was civered with squamous epithelium. On patho-logical examination of the resected meterials following radical hysterectomy, viable tumor cells had disappeared in 7 (group 1) and remained in 36 (group 2) patients. Retrospective investigation revealed a significant difference in colposcopic findings between groups 1 and 2, one week after the first chemotherapy. In regard to the remaining viable tumor cells, the pathological examination using serial biopsies revealed a significant difference between groups 1 and 2, 5 weeks after the first chmotherapy. Thus, the present results indicate that colposcopy is clinically effective in the early evaluation of the efficacy of intra-arerial injection on uterine cervical carcinoma

Luteinizing hormone-releasing hormone(LH-RH)analogueの遊離家兎陰茎海綿体機能におよぼす影響

雄家兎を3群に分け, 血中テストステロン測定後それぞれLH-RH analogue (leuprolide acetate 1.5mg/kg)の皮下注射をLH-RH群に, 精巣摘除術を精巣摘除群に, sham手術を対照群に施した.毎週血中テストステロンを測定し, 4週後に実験に供した.1週後血中テストステロン濃度はLH-RH群及び精巣摘除群で対照群に比べて有意に低下し, これはその後3週間持続した.実験浴槽内における遊離海綿体の各種刺激に対する反応性を調べた結果, LH-RH analogue投与により陰茎海綿体の収縮機能は変化しないものの, 電気刺激とsodium nitroprussideに対する弛緩反応が精巣摘除術同様に低下していたAn adverse effect of the administration of luteinizing hormone-releasing hormone (LH-RH) analogue is impotence. The effects of LH-RH analogue injection on the function of the rabbit corpus cavernosum were investigated. Eighteen male rabbits were divided into three groups, i.e., LH-RH analogue injection, castration, and sham-operated control groups. After measurement of serum testosterone, the LH-RH analogue (1.5 mg/kg leuprolide acetate) was injected once in the LH-RH group, castration in the castrated group, and sham surgery in the control group. Four weeks later, the rabbits were maintained in the same circumstance and serum testosterone was measured once a week. Four weeks after preparation, all rabbits were used for in vitro experiments. At one week the serum testosterone level of the LH-RH and castrated groups decreased significantly from that in the sham-operated control group, which was sustained for the next 3 weeks. Although contractile strength of the corporal tissue taken from the castrated group was weakened in response to phenylephrine and KCl, corporal contractile strength of the LH-RH group was not. Under precontraction with 200 microM phenylephrine relaxation of the corpus cavernosum in response to field stimulation and sodium nitroprusside significantly decreased in both the LH-RH and castrated groups. However, there were no differences in the maximal relaxations induced by ATP and bethanechol between the three groups. In conclusion, the LH-RH analogue impaired the relaxation of the corpus cavernosum induced by field stimulation and sodium nitroprusside as much as castration did. Although the corporal contraction to phenylephrine and KCl was decreased by castration, it was not altered by the LH-RH analogue