Megakaryocytic Maturation is Regulated by Maintaining a Balance Against Cytokine Induced-cell Proliferation: Steel Factor Retards Thrombopoietin-induced Megakaryocytic Differentiation While Synergistically Stimulating Mitogenesis; Hematopoiesis

Using a factor-dependent cell line MO7ER, which contains a stably transduced human erythropoietin (EPO) receptor gene in human megakaryoblastic cell line MO7e and which resulted in concomitant expression of EPO receptor, c-Mpl and c-Kit, we investigated the biological effects of these cytokines in terms of cell growth and differentiation. Thrombopoietin (TPO), EPO and Steel factor (SLF) all stimulated MO7ER cell proliferation in a dose-dependent manner. Combined stimulation of cells with SLF plus either TPO or EPO resulted in striking synergistic enhancement of MO7ER cell growth as compared with each cytokine alone, whereas combination of TPO plus EPO showed only an additive effect on cell proliferation. With regards to cell differentiation, either TPO or EPO treatment induced enhancement of platelet glycoprotein (GP) IIb/IIIa and GPIb expression. SLF induced GPIIb/IIIa and GPIb expression, but the effect was much weaker than that of EPO or TPO. However, addition of SLF to either TPO- or EPO- containing cultures (which induced potent mitogenesis in MO7ER cells) resulted in suppression of these megakaryocyte specific antigens. Addition of low-dose cytosine arabinoside (Ara-C)(1 to 10 ng/ml) enhanced TPO- or EPO- induced megakaryocytic differentiation in MO7ER cells while mildly suppressing cell growth. Treatment the cells with low-dose Ara-C plus TPO plus SLF overrode the proliferative enhancing effects of SLF and induced GPIIb/IIIa and GPIb expression as efficient as TPO alone. Retardation of TPO-induced megakaryocytic maturation was also observed in normal murine bone marrow cells by combined stimulation with TPO and SLF as assessed by the numbers of acetylcholinesterase staining-positive cells and megakaryocyte nuclear polyploidy. These results suggest that megakaryocytic maturation is, at least in part, regulated by countering cytokine-induced cell proliferation.     

Ventricular Echo Beats and Retrograde Atrioventricular Nodal Exits in the Dog Heart: Multiplicity in Their Electrophysiologic and Anatomic Characteristics

INTRODUCTION: A single ventricular echo beat frequently is induced in the dog heart by ventricular pacing, but it has not been investigated using a concomitant ablative technique. We studied the effects of ablating the anterior atrial input to the AV node on ventricular echo beats induced in the dog heart to evaluate their electrophysiologic characteristics, the anatomic reentrant circuit, and the retrograde AV nodal exits. METHODS AND RESULTS: In 20 dogs, an epicardial radiofrequency current was applied to the right anterior septum in an attempt to ablate the anterior input to the AV node. Ventricular programmed stimulation was performed to evaluate the ventricular echo beat and the retrograde AV nodal exit before and after ablation. The AV junction was examined with light microscopy. Seventeen dogs in which the PR interval was prolonged significantly from 108+/-17 msec to 153+/-19 msec (P < 0.001) were selected for ventricular echo evaluation; 3 dogs in which persistent second- or third-degree AV block was induced by ablation were excluded. Ventricular echo beats, which were induced in 13 of 17 dogs, were classified into the anterior type (n = 6) or posterior type (n = 7) according to the earliest atrial activation site during the echo beat. The retrograde AV nodal exit site showed anterior-exit only (n = 10), posterior-exit only (n = 2), and dual-exit (n = 5) patterns. After ablation, the anterior-type ventricular echo beat was noninducible in all 6 dogs, whereas the posterior-type ventricular echo beat was noninducible in only 3 of 7 dogs. In 17 dogs, VA conduction was not demonstrated after ablation in 3 dogs, all of which showed the anterior-exit only pattern. CONCLUSION: The effect of ablation on the ventricular echo beats and retrograde AV nodal exit site suggests multiplicity in their electrophysiologic and anatomic characteristics in the dog heart.     

Do Sacral/Peripheral Lesions Contribute to Detrusor‐Sphincter Dyssynergia?

Objectives: While detrusor‐sphincter dyssynergia (DSD) occurs in conjunction with lesions between the brainstem and the sacral cord, it is not well known whether sacral/peripheral lesions contribute to DSD. We studied the relationship between DSD and sacral/peripheral lesions. Methods: One hundred and forty‐four patients with diverse neurologic etiologies underwent urodynamic study and analysis of motor unit potentials in the external sphincter muscles, 117 of whom were able to void during a urodynamic test. Sacral/peripheral lesion (SPL) is defined as neurogenic change in motor unit potentials. Detrusor overactivity (DO) is defined as involuntary detrusor contractions during the filling phase, which commonly occurs in lesions above the sacral cord. We considered DO as a putative indicator of supra‐sacral lesion. Results: DSD was found in 44 (30.6%), SPL in 71 (49.3%), and DO in 83 (57.6%) of 144 patients, respectively. The incidence of DSD was the same in the SPL positive group (31%) and the SPL negative group (30.1%). By contrast, within the subgroup of patients without DO, the incidence of DSD was significantly more common in the SPL positive group (41.4%) than in the SPL negative group (25.0%) (P < 0.05). In 53 of the SPL positive group who were able to void, postvoid residual >100 mL was more common in patients with DSD (not statistically significant). Conclusion: The results of the present study suggest that not only suprasacral pathology, but also sacral/peripheral lesions can produce DSD. In light of the previous reports, DSD might also result from partial lesions in peripheral branches of the sphincter circuit.     

CASE REPORT: A long-term survivor of jejunal leiomyosarcoma with liver metastasis: Effective transcathetel arterial embolization for hepatic metastatic foci

We report a case of jejunal leiomyosarcoma with liver metastases in a 52-year-old Japanese male. An echogram demonstrated multiple cystic liver masses in April 1991. The diagnosis of metastatic leiomyosarcoma was made on the basis of characteristic hepatic angiography images and liver biopsy findings. The jejunal leiomyosarcoma was resected and unresectable liver metastatic foci were treated repeatedly with transcathetel arterial embolization. Transcathetel arterial embolization was considered to be effective in this case as the patient survived 4 years and 9 months after the first treatment.     

Anti‐Tumor Effects and Pharmacokinetics of S‐40542, a Novel Non‐Steroidal Anti‐Androgen,in Mice

Objectives: The current study was undertaken to explore novel anti‐androgens. We investigated a series of tetrahydroquinoline compounds and identified 1‐(8‐nitro‐3a,4,5,9b‐tetrahydro‐3H‐cyclopenta[c]quinolin‐4‐yl)ethane‐1,2‐diol (S‐40542). Methods: Affinity for androgen receptor of S‐40542 was evaluated in receptor binding assay. Effects of repeated treatment with S‐40542 and bicalutamide on prostate weight were examined in mice subcutaneously treated for 14days. Efficacy of S‐40542 and bicalutamide against prostate cancer was evaluated in an androgen‐dependent prostate cancer xenograft model using KUCaP‐2 cell line. Plasma concentrations of these agents in mice after oral and subcutaneous administration were measured by liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) system. Results: S‐40542 displayed twofold higher affinity to androgen receptor than bicalutamide in vitro. Subcutaneous repeated administration of S‐40542 (10–100 mg/kg) significantly reduced the prostate weight. Oral repeated treatment with S‐40542 (30, 100 mg/kg) for 28 days significantly suppressed growth of KUCaP‐2 tumor. Similar administration of bicalutamide also exerted significantly anti‐tumor effect in the model. The serum prostate‐specific antigen level was little influenced by the S‐40542 treatment, while significantly decreased by bicalutamide. Oral treatment with S‐40542 resulted in a dose‐dependent elevation of the plasma concentration, and its C_max and AUC were much lower than those of bicalutamide. The pharmacokinetic study showed that this agent had relatively short plasma half‐life and low oral bioavailability. Conclusion: S‐40542 as well as bicalutamide has shown as an anti‐androgen by reducing the prostate weight of mice. Repeated oral treatment with S‐40542 was shown to significantly suppress tumor growth in the KUCaP‐2 xenograft model.     

How the Bladder Senses? A Five‐Grade Measure

Objectives: During bladder filling, the bladder starts to sense it and the sensation steadily increases. However, little is known concerning volume‐sensory correlation in normal bladder and pressure‐sensory correlation during detrusor overactivity (DO). We aimed to real‐time assess bladder sensation in normal bladder and DO using a five‐grade measure. Methods: We enrolled 74 normal individuals and 87 patients with DO (51 terminal, 36 phasic). During slow bladder filling, we instructed individuals to indicate sensation in five grades: 1, first sensation; 2, obviously greater than 1 but less than 3; 3, first desire to void when he or she usually goes to toilet; 4, obviously greater than 3 but less than 5; and 5, strong desire to void. We also instructed individuals to report other sensations, such as pain. Results: The five‐grade measure is feasible in all participants, showing a volume and pressure‐ sensory correlation. Among the five grades, grade 0 to 1 was the longest, followed by grade 4 to 5, in all participants. Grade 0 to 1 in phasic DO and grade 4 to 5 in terminal and phasic DO were shorter than those in normal bladder (P < 0.05). Eighty‐six percent of patients with DO reported that the rapidly increased sensory grade is akin to urinary urgency in daily life. Conclusion: The five‐grade measure is feasible to assess a volume and pressure‐sensory correlation. Using this measure the sensory grade rapidly increased during DO compared with normal bladder, and 86% of the patients with DO reported that it is akin to urinary urgency in daily life.     

Micropapillary variant of transitional cell carcinoma of the bladder

A 77-year-old man visited the Kobe City General Hospital complaining of macroscopic hematuria. A computed tomography scan found a bladder tumor with left iliac and para-aortic lymph node metastasis. Two courses of cisplatin, cyclophosphamide and doxorubicin chemotherapy resulted in a minimal response. Radical cystectomy and a retroperitoneal lymph node dissection with bilateral ureterocutaneostomy reconstruction were then performed. A pathological examination revealed a micropapillary variant of transitional cell carcinoma (Grade 3, pT1pN2M1). The patient died of pelvic recurrence 7 months after the initiation of chemotherapy. Peritonitis carcinomatosa and lung metastases were observed at autopsy.     

Use of Protease Inhibitors to Improve Calcitonin Absorption from the Small and Large Intestine in Rats

The objective of this study was to examine the effects of protease inhibitors on the absorption of calcitonin from different regions of the intestine in rats. The absorption experiments were investigated by in-situ use of closed intestinal loops in rats and stability of calcitonin was examined in mucosal homogenates and intestinal fluids. The intestinal absorption of calcitonin was evaluated by measurement of its hypocalcaemic effect. No substantial hypocalcaemic response was observed when calcitonin was administered into the jejunum or colon. A slight hypocalcaemic effect was observed after administration of calcitonin into the ileum. Of the co-administered protease inhibitors, bacitracin (20 mM) strongly promoted calcitonin absorption from the jejunum, ileum and colon. A significant hypocalcaemic effect was also obtained after intestinal administration of calcitonin with soybean trypsin inhibitor (10mgmL^?1), camostat mesylate (20mM) or aprotinin (2mgmL^?1). In the stability experiment, bacitracin reduced the degradation of calcitonin in the different intestinal homogenates. Soybean trypsin inhibitor significantly reduced the degradation of calcitonin in the fluids of the small intestine. We also examined the different endopeptidases in gut luminal fluids and the different exopeptidases in gut mucosal homogenates of rats. The ranking order for the total endopeptidase activity of the intestinal fluids was jejunum > ileum > colon. That for total exopeptidase activity of the intestinal mucosa was jejunum > ileum > colon. These results suggest that endo- and exopeptidases might be responsible for the hydrolysis of calcitonin and that protease inhibitors might usefully improve absorption of calcitonin to the systemic circulation from the large intestine.     

A Multicenter Phase I/II Study of the BCNU Implant (Gliadel ? Wafer) for Japanese Patients with Malignant Gliomas

Carmustine (BCNU) implants (Gliadel^® Wafer, Eisai Inc., New Jersey, USA) for the treatment of malignant gliomas (MGs) were shown to enhance overall survival in comparison to placebo in controlled clinical trials in the United States and Europe. A prospective, multicenter phase I/II study involving Japanese patients with MGs was performed to evaluate the efficacy, safety, and pharmacokinetics of BCNU implants. The study enrolled 16 patients with newly diagnosed MGs and 8 patients with recurrent MGs. After the insertion of BCNU implants (8 sheets maximum, 61.6 mg BCNU) into the removal cavity, various chemotherapies (including temozolomide) and radiotherapies were applied. After placement, overall and progression-free survival rates and whole blood BCNU levels were evaluated. In patients with newly diagnosed MGs, the overall survival rates at 12 months and 24 months were 100.0% and 68.8%, and the progression-free survival rate at 12 months was 62.5%. In patients with recurrent MGs, the progression-free survival rate at 6 months was 37.5%. There were no grade 4 or higher adverse events noted due to BCNU implants, and grade 3 events were observed in 5 of 24 patients (20.8%). Whole blood BCNU levels reached a peak of 19.4 ng/mL approximately 3 hours after insertion, which was lower than 1/600 of the peak BCNU level recorded after intravenous injections. These levels decreased to less than the detection limit (2.00 ng/mL) after 24 hours. The results of this study involving Japanese patients are comparable to those of previous studies in the United States and Europe.