Holmium:YAG laser endoureterotomy in the treatment of ureteroenteric stricture following Indiana urinary diversion

A 57-year-old man who had received radical urethrocystectomy and Indiana urinary diversion 6 months earlier was treated for ureteroenteric anastomosis stricture (left side) using a Holmium:YAG laser via antegrade approach. The availability of small (6.9 Fr) flexible ureteroscope, as well as the use of the Holmium:YAG laser has facilitated the ability to precisely incise the stricture under direct endoscopic visualization. The technique is described for laser endoureterotomy in a patient with ureteroenteric stricture following Indiana urinary diversion.

The treatment with tranilast, a mast cell blocker, for idiopathic oligozoospermia

Although many drug treatments have been reported to theoretically improve semen parameters in male infertility, a standard method has not been established. The authors examined whether tranilast, a mast cell blocker, improves fertility and/or semen parameters in severe oligozoospermia. Seventeen patients with a sperm density of less than 10 x 10(6) sperm/mL and their fertile partners were enrolled in this study. Patients were prescribed tranilast 300 mg/day for at least 12 weeks. Semen and blood samples were collected before and after the prescription of tranilast for 12 weeks. Semen parameters, serum gonadotropins, luteinizing hormone, follicle-stimulating hormone, serum testosterone, and testicular size were evaluated. One patient complained of mild drowsiness during treatment. The sperm count was significantly increased after administration of tranilast in 7 patients (41.1%), although sperm motility was not altered. Semen volume and normal morphology were also unaltered. Three pregnancies were achieved. Endocrine profile and testicular size were unchanged. Tranilast, a mast cell blocker, is clinically useful for the treatment of severe idiopathic oligozoospermic men.

Oxidation-active flavin models: oxidation of alpha-hydroxy acids by benzo-dipteridine bearing metal-binding site in the presence of divalent metal ion and base in organic solvents

The oxidizing ability of benzo-dipteridine bearing a bipyridin-6-ylmethyl moiety (4) was found to be increased with Zn(2+) by approximately 10(3)-fold for sulfite addition in MeOH and approximately 10(2)-fold for oxidation of an NADH model in MeCN. It was found for the first time that 4 is able to oxidize alpha-hydroxy acids to alpha-keto acids in the presence of a divalent metal ion such as Zn(2+), Co(2+), and Ni(2+) and an amine base in MeCN or t-BuOH, whereas benzo-dipteridine having a bipyridin-5-ylmethyl moiety (3) is unable to oxidize them under the same conditions. The oxidation reaction was kinetically investigated including the kinetic isotope effect for deuterated mandelic acids (k(H)/k(D) = 2.1-3.7) and the Hammett plots for substituted mandelic acids (V-shaped plots). In the reaction of alpha-substituted alpha-hydroxy acids such as alpha-methyl mandelic and benzylic acids with 4, novel oxidative decarboxylation was found to take place, giving acetophenone and benzophenone, respectively. The oxidation mechanism for mandelic acid was proposed to proceed via a ternary complex of 4.Zn(2+).PhCH(OH)CO(2)(-), in which alpha-oxyanion of mandelate attacks C(4a)-position of 4 to form an adduct followed by 1,2-elimination to afford benzoyl formate and 2e-reduced 4. The roles of the metal ion were proposed as follows; (i) activation of 4, (ii) substrate-binding site, and (iii) activation of the bound alpha-hydroxy acid by lowering pK(a)'s of alpha-OH and alpha-CH. This is a first example that a flavin model oxidizes alpha-hydroxy acids in the presence of a metal ion.

CA19-9-producing transitional cell carcinoma of the renal pelvis: a case report

We report a case of CA19-9-producing transitional cell carcinoma of the renal pelvis. A 59-year-old male patient with left hydronephrosis was referred to us from a local physician. Retrograde pyelogram revealed irregular filling defects involving calices, pelvis and proximal ureter. The serum CA19-9 level was elevated. Under the diagnosis of renal pelvic tumor, we performed radical left nephroureterectomy. The tumor was histologically diagnosed as transitional cell carcinoma. The tumor cells showed positive immunostaining for CA19-9. The serum CA19-9 level was normalized after the operation. To our knowledge, this is the 28th case of a CA19-9-producing tumor in the Japanese literature.

Pacemaker shift in the rabbit sinoatrial node in response to vagal nerve stimulation

Effects of brief postganglionic vagal nerve stimulation on the activation sequence of the rabbit sinoatrial (SA) node were investigated. Activation sequences in a small area (7 mm x 7 mm) on the epicardial surface were measured in a beat-to-beat manner using an extracellular potential mapping system composed of 64 modified bipolar electrodes with high-gain and low-frequency band-pass filtering. The leading pacemaker site was recognised clearly from both the activation sequence and the characteristic morphology of the potentials. Vagal stimulation resulted in a short-lasting initial slowing of spontaneous rate followed by a long-lasting secondary slowing; a brief period of relative or absolute acceleration was interposed between the two slowing phases. During these changes of spontaneous rate, the leading pacemaker site shifted in a complex beat-to-beat manner by 1-6 mm alongside the crista terminalis in the superior or inferior direction. For the first spontaneous excitation following stimulation, the greater the slowing, the larger the distance of the pacemaker shift. There was no such linear relationship between the extent of slowing and the distance of pacemaker shift for the subsequent beats. These changes in the leading pacemaker site in response to vagal stimulation may be the result of the functional and morphological heterogeneity of the mammalian SA node in terms of innervation, receptor distribution and ion channel densities. Experimental Physiology (2001) 86.2, 177-184.

Immune tolerance induced by polyethylene glycol-conjugate of protein antigen: clonal deletion of antigen-specific Th-cells in the thymus

Polyethylene glycol (PEG) conjugates of protein antigens induce antigen-specific immune tolerance of helper T (Th)-cells. However, the mechanism of this Th-cell tolerance has remained unelucidated. Using transgenic mice with ovalbumin (OVA)-specific T-cell receptor (TCR) genes, we examined the response of OVA-specific Th-cells towards tolerogenic PEG-conjugate of OVA in vitro and in vivo. When stimulated with PEG--OVA in vitro, transgenic OVA-specific Th-cells proliferated and produced interleukin 2, the levels of which were comparable to those induced by unmodified OVA. In contrast, PEG--OVA administered into the circulation of transgenic mice induced unresponsiveness in peripheral OVA-specific Th-cells. Moreover, in the thymus of these transgenic mice, the frequency of immature CD4+CD8+ (double positive) thymocytes was reduced. A similar phenomenon was not observed in transgenic mice treated with unmodified OVA. As autoreactive T-cells are known to be clonally deleted at the immature double positive stage in the thymus. Th-cell tolerance induced by PEG--protein antigens is at least in part mediated by central tolerance in the thymus, and is likely caused by the markedly enhanced stability of PEG--protein conjugates in the circulatory system.

Evidence for the involvement of the GTS1 gene product in the regulation of biological rhythms in the continuous culture of the yeast Saccharomyces cerevisiae

In the yeast Saccharomyces cerevisiae, ultradian oscillations of energy metabolism have been observed in continuous cultures. Here, we found that the level of the GTS1 gene product oscillated in concert with the ultradian rhythm of energy metabolism. When GTS1 was inactivated by gene disruption, the metabolic oscillation was affected severely, mostly disappearing within a day, in the absence of synchronized stress-response oscillations throughout the continuous culture. The disappearance of biological rhythms in the GTS1-deleted mutant was substantially rescued by transformation with chimera plasmids carrying GTS1 under the control of GTS1's own promoter. On the other hand, this disappearance was not rescued by constitutive expression of GTS1 under the control of the triose phosphate isomerase promoter.

Color Doppler sonography for evaluating response to transcatheter arterial embolization and percutaneous ethanol injection therapy and for detecting recurrence of hepatocellular carcinoma

Eighty-six patients (mean age, 63 years) with 92 hepatocellular carcinomas (2.0 cm or greater in diameter; mean +/- SD, 3.5 +/- 1.6 cm) underwent color Doppler sonography before and after transcatheter arterial embolization and after subsequent percutaneous ethanol injection for (1) identification of pulsatile flow in the residual tumor area after transcatheter arterial embolization, (2) evaluation of therapeutic effectiveness of combined transcatheter arterial embolization and percutaneous ethanol injection, and (3) detection of recurrence during follow-up evaluation. Before and 2 weeks after transcatheter arterial embolization, color Doppler sonography revealed pulsatile flow in 76 (82.6%) and 43 (46.7%)lesions, respectively. After percutaneous ethanol injection, tumor stains in these lesions completely disappeared on digital subtraction angiography (gold standard). During follow-up study (3 to 45 months), digital subtraction angiography revealed recurrence in 73 patients (38 local recurrences and 19 new lesions [2.0 cm or greater]), whereas color Doppler sonography revealed pulsatile flow in 76.3% (local) and 63.2% (new) (not significant). Color Doppler sonography was useful for complying with our three objectives, especially for detecting local recurrence during follow-up evaluation.

Sonographically guided core-needle biopsy of focal splenic lesions: report of four cases

There are few published reports about the use of splenic needle biopsies in the investigation of focal splenic lesions. We report our experience with sonographically guided core-needle biopsies of splenic lesions in 4 patients. The biopsies resulted in the following diagnoses: sarcoidosis, malignant lymphoma, infarction, and scar tissue. Surgery was avoided in the 3 patients diagnosed with sarcoidosis, infarction, and scar tissue by ruling out the possibility of a malignant splenic tumor. None of the patients experienced significant complications. We conclude that splenic core-needle biopsy is a useful and safe diagnostic tool for the evaluation of focal splenic lesions.

Participation of granulocyte colony-stimulating factor in the growth regulation of leukemia cells from Philadelphia chromosome-positive acute leukemia and blast crisis of chronic myeloid leukemia

Granulocyte colony-stimulating factor (G-CSF) has been shown to support the growth of multipotential hematopoietic stem cells in addition to the cells of neutrophilic lineage. Philadelphia chromosome (Ph1)-positive leukemia has its origin in the hematopoietic stem cell. In the present study, we demonstrated that the proliferation of leukemic cells from chronic myeloid leukemia in blast crisis (CML-BC) and Ph1-positive acute lymphoblastic leukemia (ALL) cases is frequently stimulated with G-CSF in vitro. We next studied a total of 12 leukemic cell lines established from CML-BC (n= 6) and Ph1-positive acute leukemia (n= 6): four 'myeloid', five 'biphenotypic', and three 'lymphoid' types. All cell lines expressed G-CSF receptor (G-CSFR) in flow cytometric analysis, but their proliferative response to G-CSF in 3H-thymidine incorporation assay varied. The 'biphenotypic' cell lines expressed G-CSFR at higher levels and showed the most pronounced response to G-CSF. The 'lymphoid' cell lines showed intermediate G-CSFR expression with the modest response to G-CSF. Unexpectedly, 'myeloid' cell lines showed lower G-CSFR expression and lower G-CSF response compared with 'biphenotypic' cell lines. In three of four 'myeloid' cell lines, proliferation was partially inhibited by an addition of anti-G-CSF neutralizing monoclonal antibody into culture medium. Further, the % inhibition of 3H-thymidine uptake of cell lines positively correlated with the amount of their intracellular G-CSF measured by enzyme immunoassay, suggesting an autocrine growth mechanism via the G-CSF/G-CSFR interaction. These results suggest that G-CSF play an important role in the growth regulation of leukemia cells from Ph1-positive acute leukemia and CML-BC.

Cellular stress responses oscillate in synchronization with the ultradian oscillation of energy metabolism in the yeast Saccharomyces cerevisiae

We investigated whether cellular responses to various stress conditions are regulated in synchronization with the ultradian rhythm of respiratory-fermentative metabolism which is coupled to the cell cycle rhythm in continuous cultures of the yeast Saccharomyces cerevisiae. The cellular resistance to heat oscillated with a peak at the late respiro-fermentative phase, which approximately corresponds to the unbudding period of the cell cycle. Cellular resistance to H(2)O(2) and that to the superoxide-generating agent menadione oscillated in the same phase as that of heat resistance. The resistance to cadmium and that to 1-chloro-2,4-dinitrobenzene, an uncoupler of energy metabolism in mitochondria, both oscillated with a peak advanced by about 80 degrees relative to that of heat resistance, approximately covering the respiro-fermentative phase. Thus, cellular resistance to various stresses in S. cerevisiae oscillated in synchronization with the metabolic oscillation in the continuous culture.

Phosphorylation of the GTS1 gene product of the yeast Saccharomyces cerevisiae and its effect on heat tolerance and flocculation

The GTS1 gene from the yeast Saccharomyces cerevisiae showed pleiotropic effects on yeast phenotypes, including an increase of heat tolerance in stationary-phase cells and an induction of flocculation. Here, we found that the GTS1 product, Gts1p, was partially phosphorylated at some serine residue(s) in cells grown on glucose. Studies using mutants of protein kinase A (PKA) and CDC25, the Ras-GTP exchange activator, showed that PKA positively regulated the phosphorylation level of Gts1p. Overexpression of Gts1p in a mutant with attenuated PKA activity did not show any increase of heat tolerance and partially decreased flocculation inducibility, suggesting that phosphorylation of Gts1p is required for induction of these phenomena.

Dynamic measurement of single protein's mechanical properties

Dimerized (tandemly repeated) protein was constructed, and the stretching force during the unfolding of the single protein molecule was measured using an atomic force microscope. In quasistatic measurements using normal force-distance curve measurements, each monomer unit was unfolded step by step. To elucidate the conformational state at each extension length, we measured the relax-stress response of the protein using short stroke sinusoidal movements of the sample stage. This allowed us to investigate the dynamic response of the protein repeatedly without full stretching or rupturing. Although the protein molecule responded in-phase to the applied movement in most cases, we found a novel out-of-phase response around the stretching length where the second monomer unit unfolded. Applying the spring constant measured in the quasistatic experiment, the out-of-phase response was reproduced in the simple calculation, which suggested the folding and the unfolding at the second monomer unit were taking place repeatedly during the relax-stress response measurement.

Cytologic differential diagnosis among reactive mesothelial cells, malignant mesothelioma, and adenocarcinoma: utility of combined E-cadherin and calretinin immunostaining

BACKGROUND

The differential diagnosis between reactive mesothelial cells (RMs), malignant mesotheliomas (MMs), and adenocarcinomas (ACs) is often difficult in cytologic specimens, and the utility of various immunohistochemical markers have been explored. Because recent immunohistologic studies have suggested that E-cadherin (E-cad) and calretinin (Cal) may be useful markers for epithelial and mesothelial differentiations, respectively, the authors investigated their utility in cytologic diagnosis.

METHODS

In this retrospective study, immunostaining was performed on smears retrieved from Papanicolaou-stained slides of effusions using the labeled streptavidin-biotin method. Sixteen cases of RM, 9 cases of MM, and 52 cases of AC from various sites, including 13 pulmonary primaries, were examined with primary antibodies against E-cad and Cal.

RESULTS

The positive rates for E-cad and Cal, respectively, were as follows: RM, 0/16 (0%) and 16/16 (100%); MM, 9/9 (100%) and 8/8 (100%); and AC, 45/52 (86.5%) and 0/51 (0%). The E-cad expression by neoplastic cells was strongest in the intercellular junctions, and poorly differentiated neoplastic cells in the single cell form showed the weakest expression.

CONCLUSIONS

In contrast to the results of previous immunohistochemical studies, the current study indicates that MMs constantly express E-cad, whereas RMs lack its expression in cytologic specimens, which would be useful in the differential diagnosis between the two. On the other hand, E-cad expression is not reliable for distinguishing AC from MM. The Cal expression can be a very useful marker for the distinction between AC and the mesothelial lineage. The combined immunostaining for E-cad and Cal has utility in differential diagnosis among RM, MM, and AC.

Genetic regulation of anti-erythrocyte autoantibodies and splenomegaly in autoimmune hemolytic anemia-prone new zealand black mice

New Zealand Black (NZB) mice spontaneously produce anti-erythrocyte autoantibodies (AEA) in association with splenomegaly, thus serving as a model for autoimmune hemolytic anemia. Although these autoimmune traits are inherited as a dominant fashion, expression in F(1) hybrids of NZB and most non-New Zealand strains is suppressed due to the contribution of wild-type modifying genes present in the latter strains. Using chromosomal microsatellite markers in the (C57BL/6 x NZB)F(1) x NZB backcross progeny, we mapped C57BL/6 modifying loci for AEA production and splenomegaly. Generation of AEA was found to be down-regulated by a combined effect of two major independently segregating dominant alleles-one linked to D7MIT30 on chromosome 7 and the other linked to D10MIT42 on chromosome 10. Splenomegaly was modified mainly by a single C57BL/6 allele linked to D4MIT58 on chromosome 4. Thus, the autoimmune hemolytic anemia in the NZB strain is under multigenic control and a combined action of not only susceptibility but also modifying alleles with suppressive activities affects the outcome of disease features in the progeny. There are potentially important candidate genes which may be linked to the regulation of AEA and splenomegaly.

Holmium laser incision technique for ureteral stricture using a small-caliber ureteroscope

BACKGROUND AND OBJECTIVES

The holmium laser has a short absorption depth in tissue and possesses excellent properties both in ablation and hemostasis. We have performed endoscopic incision for ureteral stricture using the holmium laser through a small-caliber ureteroscope.

METHODS

This method was used on five patients and seven ureters. The etiology of the stricture was stone scar in two patients, ureteroenteroanastomosis of Indiana urinary pouch in two, and primary in one. We used an 8F semi-rigid or 6.9F flexible ureteroscope. No prior procedures, such as balloon dilation, were necessary in any of the cases. The stricture was incised with the holmium laser using a 365-microm fiber through the working channel of the ureteroscope. The holmium laser operated at a wavelength of 2100 nm, with an output of 1.0 J/pulse at a rate of 10 Hz. After completion of the incision, a 12F Double-J catheter was left in for six weeks.

RESULTS

The mean operative time was 89 minutes. The stricture resolved completely in all cases at an average follow-up of 8.6 months.

CONCLUSIONS

The holmium laser incision for ureteral stricture using a small-caliber ureteroscope is an easy-to-perform, safe and effective procedure.

A novel human gene encoding HECT domain and RCC1-like repeats interacts with cyclins and is potentially regulated by the tumor suppressor proteins

Cyclin E-Cdk2 is an evolutionary conserved cyclin-dependent kinase (CDK) complex that drives the G1 to S phase transition of the cell cycle. A novel cDNA encoding a HECT family protein also containing RCC1-like repeats was isolated by a yeast two-hybrid screening using both cyclin E and its inhibitor p21. The protein product of this cDNA, Ceb1, interacts with various cyclin subunits of CDKs in mammalian cells. Expression of Ceb1 is specifically detected in testis and ovary and is highly elevated when the functions of the tumor suppressor proteins, p53 and RB, are compromised by mutations or viral oncoproteins. The present results suggest that Ceb1 may play a critical role when its expression and the CDK activity are upregulated by inactivation of p53 and RB.

Cloning and characterization of a novel p21(Cip1/Waf1)-interacting zinc finger protein, ciz1

p21(Cip1/Waf1) inhibits cell-cycle progression by binding to G1 cyclin/CDK complexes and proliferating cell nuclear antigen (PCNA) through its N- and C-terminal domains, respectively. Here, we report a novel p21(Cip1/Waf1)-interacting protein, Ciz1 (for Cip1 interacting zinc finger protein), which contains polyglutamine repeats and glutamine-rich region in the N-terminus as well as three zinc-finger motifs and one MH3 (matrin 3-homologous domain 3) in the C-terminal region. Ciz1 bound to the N-terminal, the CDK2-interacting part of p21(Cip1/Waf1), and the interaction was disrupted by the overexpression of CDK2. A region of about 150 amino acids containing the first zinc-finger motif in Ciz1 was the binding site for p21(Cip1/Waf1). When Ciz1 and p21(Cip1/Waf1) were individually overexpressed in U2-OS cells, they mostly localized in the nucleus. However, coexpression of Ciz1 induced cytoplasmic distribution of p21(Cip1/Waf1). These data indicate that Ciz1 is a unique nuclear protein that regulates the cellular localization of p21(Cip1/Waf1).

The DLP1 mutant of the yeast Saccharomyces cerevisiae with an increased copy number of the 2micron plasmid shows a shortened lifespan

We isolated and characterized a recessive mutant, named dlp1, which shows the Dlp phenotype (delayed loss of proliferation activity) during the autophagic death of cdc28. The dip1 mutant was found to consist of two subtypes of cells based on colony morphology. One subtype with the Dlp phenotype, named dlp1-1, became large, red, and nibbled during the incubation, suggesting that the cells on the surface of the colonies were dying. The other without the Dlp phenotype, named dlp1-s, retained small, white colonies even after a prolonged incubation and was found to be a petite mutant. The change from dlp1-1 to dlp1-s (petite) occurred much more frequently (about 15%) than that from the wild-type to petite mutant (less than 1%). The lifespan of both subtypes of cells was severely shortened. The copy number of the endogenous 2micron plasmid of dlp1-1 was 68-fold that of the original cdc28, and decreased by half after the conversion to dlp1-s (petite). A 4.0-kbp fragment of the 2micron plasmid containing REP2 decreased the copy number of the endogenous 2micron plasmid to 8-fold that of the original cdc28 cells and partially rescued the shortened lifespan, in addition to resulting in the complete complementation of the Dlp and nibbled-colony phenotypes. These results suggest that DLP1 is a chromosomal gene that regulates the copy number of the 2micron plasmid, and that the shortening of the lifespan and other effects of the dlp1 mutation are likely caused by the increased copy number of the endogenous 2micron plasmid.

Specific loss of chondromodulin-I gene expression in chondrosarcoma and the suppression of tumor angiogenesis and growth by its recombinant protein in vivo

Chondromodulin-I (ChM-I) was previously identified as an angiogenesis inhibitor in cartilage. Here, we demonstrated that the level of ChM-I transcripts was substantially reduced to 100 or even less in the lower-grade chondrosarcomas, in articular cartilage or other benign cartilage tumors. We implanted human chondrosarcoma OUMS-27 cells into nude mice that reproducibly produced tumors with cartilaginous matrix. Tumor-induced angiogenesis was evident when the tumors were excised 30 days after implantation. However, the local administration of recombinant human ChM-I almost completely blocked vascular invasion and tumor growth in vivo. Moreover, ChM-I also inhibited the growth of HT-29 colon adenocarcinoma in vivo, implying its therapeutic potential for solid tumors.

Correlation of unilateral thoracoscopic lung volume reduction with improvement in lung function and exercise performance in patients with severe pulmonary emphysema

This study was conducted to investigate the correlation of thoracoscopic lung volume reduction to changes in pulmonary function and exercise performance in patients with pulmonary emphysema. Unilateral thoracoscopic lung volume reduction treatment was performed in 30 patients with severe pulmonary emphysema. If large bullae were present, they were excised using an endoscopic stapling device, and the emphysematous pleura was contracted by neodymium:yttrium-aluminium-garnet laser to reduce the volume of nonfunctional lung air space. Pulmonary function and incremental exercise tests were performed before and at least 3 months after treatment. Follow-up functional evaluation showed a highly significant improvement in the forced expiratory volume in 1s (FEV1), forced vital capacity, static compliance, and maximal oxygen uptake. The functional residual capacity as measured by the gas dilution method (FRCgas), was unchanged; however, it was found to be decreased significantly when measured by body plethysmograph (FRCbox). Positive correlations existed between the reduction in FRCbox and the increase in FEV1 (r = 0.586, P = 0.0042) and maximal oxygen uptake (r = 0.550, P = 0.018). Pulmonary ventilation and exercise ability in patients with pulmonary emphysema were improved in a volume-dependent manner by thoracoscopic lung volume reduction. These findings indicate that patients with a preoperative trapped gas volume level exceeding 11 would be ideal candidates for thoracoscopic lung volume reduction.

Caspase activation during apoptotic cell death induced by expanded polyglutamine in N2a cells

Huntington disease (HD) is an autosomal dominant neurodegenerative disorder. To investigate the mechanism of neurodegeneration induced by mutant huntingtin, we developed a stable neuro2a cell line expressing truncated N-terminal huntingtin (tNhtt) with EGFP using the ecdysone-inducible system. The formation of aggregates and the cell death induced by expression of tNhtt with expanded polyglutamine was repeat length- and dose-dependent. Caspases were activated, and the death substrates of caspases, lamin B and ICAD (an inhibitor of caspase-activated DNase), were cleaved in this cell death process. The cleavage of lamin B was inhibited by caspase inhibitors. These findings suggest that the cell death induced by tNhtt with expanded polyglutamine is mediated by caspases.

High-performance liquid chromatographic-fluorimetric assay for cathepsin A (lysosomal protective protein) activity

A rapid and sensitive assay for the determination of cathepsin A activity is reported. This method is based on fluorimetric detection of a dansylated peptide, 5-dimethylaminonaphthalene-1-sulfonyl-L-Phe, enzymatically formed from the substrate 5-dimethylaminonaphthalene-1-sulfonyl-L-Phe-L-Leu, after separation by high-performance liquid chromatography using a C18 reversed-phase column and isocratic elution. This method is sensitive enough to measure 5-dimethylaminonaphthalene-1-sulfonyl-L-Phe at concentrations as low as 300 fmol, yields highly reproducible results and requires less than 7.0 min per sample for separation and quantitation. The optimum pH for cathepsin A activity was 4.5-5.0. The Km and Vmax values were respectively 14.9 microM and 27.91 pmol/microg/h with the use of enzyme extract obtained from mouse kidney. Cathepsin A activity was strongly inhibited by Ag+, Hg2+, diisopropylfluorophosphate and p-chloromercuriphenylsulphonic acid. Among the organs examined in a mouse, the highest specific activity of the enzyme was found in kidney. The sensitivity and selectivity of this method will aid in efforts to examine the physiological role of this peptidase.

Clinical study on recurrence in bladder cancer patients undergoing total cystectomy--statistical analysis of factors related to recurrence

A clinico-pathological study was performed retrospectively for 77 patients undergoing total cystectomy for primary transitional cell carcinoma of the urinary bladder between 1981 and 1995 to clarify the mode of recurrence, the risk factors which may affect recurrence following cystectomy and prognostic factors. Postoperative recurrence was recognized in 27 (35.1%) out of 77 patients and the one-, two- and three-year non-recurrent rates by the Kaplan-Meier method were 75.3, 64.9% and 63.3%, respectively. The duration from cystectomy to recurrence was 1 to 102 months with a mean of 12.1 months, and approximately 92.6% of recurrence occurred within two years. Among 27 patients with recurrence, pelvic recurrence, distant metastasis, both of them and urethral recurrence were recognized in 6 (22.2%), 18 (66.7%), 1 (3.7%) and 2 (7.4%), respectively as the first site of recurrence. The overall one-, three- and five-year cause-specific survival rates of the 77 patients were 84.7, 71.1% and 65.6%, respectively. Of the 27 patients with recurrence, 25 (92.6%) died of bladder cancer. Of the factors related to recurrence or prognosis, pathological stage, lymphatic invasion, venous invasion, type of infiltration and lymph node metastasis but not pathological grade or adjunctive chemotherapy were significant risk factors for recurrence and prognostic factors in univariate analysis. However, lymphatic invasion was the only significant risk factor for recurrence and prognosis in multivariate analysis using Cox's proportional hazard model.

APS, an adaptor protein containing Pleckstrin homology (PH) and Src homology-2 (SH2) domains inhibits the JAK-STAT pathway in collaboration with c-Cbl

We cloned a novel adaptor protein, APS (adaptor molecule containing Pleckstrin homology (PH) and Src Homology-2 (SH2) domains), which was tyrosine phosphorylated in response to c-kit or B cell receptor stimulation. Here, we report that APS was tyrosine phosphorylated by Janus kinase-2 (JAK2) at its C-terminal tyrosine residue and interacted with c-Cbl. Forced expression of APS in an erythropoietin (EPO)-dependent hematopoietic cell line resulted in reduced activation of STAT5 but not cell proliferation in response to EPO. APS bound to the phosphorylated tyrosine residue, Y343 of the erythropoietin receptor cytoplasmic domain. Co-expression of APS and c-Cbl, but not expression of either alone inhibited EPO-dependent STAT5 activation in 293 cells. This required the C-terminal phosphorylation site, as well as PH and SH2 domains of APS. Therefore, one of the major functions of APS is in recruitment of c-Cbl into the receptor/JAK complex, thereby inhibiting JAK signaling activity.