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T Umeyama

Publications and source records attributed to T Umeyama.

At least 37 records · Page 2Linked to original sources
PubMed1993

Dynamics of microtubules bundled by microtubule associated protein 2C (MAP2C).

MAP2C is a microtubule-associated protein abundant in immature nerve cells. We isolated a cDNA clone encoding whole mouse MAP2C of 467 amino acid residues. In fibroblasts transiently transfected with cDNA of MAP2C, interphase microtubule networks were reorganized into microtubule bundles. To reveal the dynamic properties of microtubule bundles, we analyzed the incorporation sites of exogenously introduced tubulin by microinjection of biotin-labeled tubulin and the turnover rate of microtubule bundles by photoactivation of caged fluorescein-labeled tubulin. The injected biotin-labeled tubulin was rapidly incorporated into distal ends of preexisting microtubule bundles, suggesting a concentration of the available ends of microtubules at this region. Although homogenous staining of microtubule bundles with antibiotin antibody was observed 2 h after injection, the photoactivation study indicated that turnover of microtubule bundles was extremely suppressed and < 10% of tubulin molecules would be exchanged within 1 h. Multiple photoactivation experiments provided evidence that neither catastrophic disassembly at the distal ends of bundles nor concerted disassembly due to treadmilling at the proximal ends could explain the observed rapid incorporation of exogenously introduced tubulin molecules. We conclude that microtubules bundled by MAP2C molecules are very stable while the abrupt increase of free tubulin molecules by microinjection results in rapid assembly from the distal ends within the bundles as well as free nucleation of small microtubules which are progressively associated laterally with preexisting microtubule bundles. This is the first detailed study of the function of MAPs on the dynamics of microtubules in vivo.

Animals↗
PubMed1992

The 72-kDa microtubule-associated protein from porcine brain.

A microtubule-associated protein (MAP) with a molecular mass of 72-kDa that was purified from porcine brain by using its property of heat stability in a low pH buffer was characterized. Low-angle rotary shadowing revealed that the 72-kDa protein was a rodlike protein approximately 55-75 nm long. The 72-kDa protein bound to microtubules polymerized from phosphocellulose column-purified tubulin (PC-tubulin) with taxol and promoted the polymerization of PC-tubulin in the absence of taxol. Microtubules polymerized by the 72-kDa protein showed a tendency to form bundles of several microtubules. Quick-freeze, deep-etch electron microscopy revealed that the 72-kDa protein formed short crossbridges between microtubules. We performed peptide mapping to analyze the relationship of the 72-kDa protein to other heat-stable MAPs, and the results showed some resemblance of the 72-kDa protein to MAP2. Cross-reactivity with a monoclonal anti-MAP2 antibody further suggested that the 72-kDa protein and MAP2 are immunologically related. To study the relationship between the 72-kDa protein and MAP2C, a smaller molecular form of MAP2 identified in juvenile rat brain, we prepared the 72-kDa protein from rat brain by the same method as that used for porcine brain. The fact that the 72-kDa protein from juvenile rat brain was also stained with our monoclonal anti-MAP2 antibody also suggested that the 72-kDa protein is an MAP2C homologue of the porcine brain.

Animals↗
PubMed1992

Increased microtubule stability and alpha tubulin acetylation in cells transfected with microtubule-associated proteins MAP1B, MAP2 or tau.

We previously transfected MAP2, tau and MAP1B cDNA into fibroblasts and have studied the effect of expression of these microtubule-associated proteins on microtubule organization. In this study, we examined some additional characteristics of microtubule bundles and arrays formed in fibroblasts transfected with these microtubule-associated proteins. It was found that microtubule bundles formed in MAP2c- or tau-transfected cells were stabilized against microtubule depolymerizing reagents and were enriched in acetylated alpha tubulin. When mouse MAP1B cDNA was expressed following transfection into COS cells, MAP1B was localized along microtubule arrays, but no extensive reorganization of microtubules such as bundle formation was observed, in agreement with our previous finding using HeLa and 3T3 cells. However, stabilization of microtubules was indicated: (a) microtubules in MAP1B-transfected cells were stabilized against a microtubule depolymerizing reagent, although stabilization was less efficient than that seen in MAP2c- or tau-transfected cells, and (b) microtubules in MAP1B-transfected cells were enriched in acetylated alpha tubulin. These results suggest that neuronal microtubule-associated proteins introduced into fibroblasts by cDNA transfection stabilize microtubules and affect the state of post-translational modification of tubulin.

Acetylation↗
PubMed1991

Immunohistochemical study of metallothionein in normal and benign prostatic hyperplasia of human prostate.

Metallothionein (MT) in the human prostate gland was examined. Prostatic tissues were obtained from patients of urinary bladder cancer who had received radical cystoprostatectomy. MT content was 99.3 micrograms/g wet tissue (w.t.) in the peripheral zone (PZ), 12.0 micrograms/g w.t. in the preprostatic region (PR), 7.3 micrograms/g w.t. in the central zone (CZ), 6.8 micrograms/g w.t. in the anterior fibromuscular stroma, and 29.5 micrograms/g w.t. in benign nodular hyperplasia (adenoma) by radioimmunoassay. Immunohistochemical study demonstrated that MT was localized in the cytoplasm, nuclei of glandular epithelia, and secretory products. In general, a positive immunoreaction was strong in PZ and weak in CZ. It is considered that glandular epithelial cells in PZ, PR, CZ, and adenoma may react differently to heavy metals, e.g., zinc and cadmium.

Aged↗
PubMed1991

Multielement analysis of kidney tissue with renal calculi.

Tissue distribution and concentration gradients of macro- and micro-elements in the papilla, medulla, and cortex of human kidney with renal calculi were measured with spectrometer. An uninvolved portion of the hypernephroma kidney was used as control. Cadmium (Cd), cobalt (Co), and molybdenum (Mo) were least in amount in renal papilla as compared with the cortex and medulla in renal stone kidney. Overall there was less Mo in stone kidney tissue, and also significantly less when compared with that of control renal papilla. Considering the reported fact that Mo was found in high concentrations in urinary tract stones and our data that Mo was less in stone kidney, it is speculated that Mo may play some unexplained but significant role in certain stage(s) of the stone formation.

Carcinoma, Renal Cell↗
PubMed1990

Protein factor obtained from rat adipose tissue specifically permits the proliferation of the 3T3-L1 and Ob1771 cell lines.

We have found the presence of protein factor in rat adipose tissue which permits the proliferation of 3T3-L1 and Ob1771 preadipocytes cultured in a completely defined serum-free medium containing only progression factors [epidermal growth factor (EGF) and insulin] as growth factors. This mitogenic activity of the protein factor was not detected in various other cell lines, in particular, Swiss 3T3 cells which could proliferate in response to a competent factor [platelet-derived growth factor (PDGF) or fibroblast growth factor (FGF)] in the same serum-free medium. This activity of the factor was heat- and pronase-unstable, and reductant-stable, and the apparent molecular weight of the factor was about 20,000. These results strongly suggest that the protein factor is different from PDGF or FGF and contributes to the formation of new adipocytes by specifically stimulating the proliferation of preadipocytes, acting like competent factor.

Adipose Tissue↗
PubMed1990

[Treatment of ureteral calculi by extracorporeal shock wave lithotripsy].

We reviewed 465 cases of ureteral calculi treated at Jömö Urological Hospital using a Dornier HM3 lithotripter during the period from October 1985 to February 1989. The 336 men and 122 women ranged from 11 to 78 years old with a mean age of 42.2. The stone size ranged from 4 mm to 30 mm with a mean length of 10.6 mm. Complete stone elimination by ESWL was achieved in 431 of the 465 cases (92.7%). The success rate was best for stones in the lower ureter, which was 98.1 per cent (53/54). For upper and mid ureteral calculi it was 92.4 per cent (363/393) and 83.3 per cent (15/18), respectively. ESWL after push up made 100 per cent (30/30) of patients completely free of stones, while ESWL after bypass 93.0 percent (106/114) and ESWL in situ 91.9 per cent (295/321). The rate of residual stone increases in proportion to the age of patients. Minor side effects such as fever and pain were observed. Our results suggest that ESWL currently is the first therapeutic option for the majority of ureteral calculi.

Adolescent↗
PubMed1988

[A case of leiomyoma of the spermatic cord].

A 46-year-old man visited our clinic with the chief complaint of indolent swelling of the left scrotal contents. An elastic hard and fist-sized mass with negative transillumination was palpable in left scrotum, but testis and epididymis were not discriminated. Left high orchiectomy was performed. Tumor was 90 X 55 mm in size and the testis and epididymis at the lower pole of the tumor were intact. Histological diagnosis was leiomyoma and we diagnosed leiomyoma of the spermatic cord. To our knowledge, this is the 5th case reported in Japan.

Genital Neoplasms, Male↗
PubMed1988

[A clinical study of tumor of the renal pelvis and ureter].

We report 54 patients with urothelial tumors in upper urinary tract admitted to our hospital between July, 1962 and December, 1985. The patients consisted of 38 males and 16 females; side their ages ranged from 47 to 88 years with a mean of 63.4 years. The affected side was the right side in 21 cases, and the left side in 33 cases. Macro-or microhematuria was observed in 87% of the patients. Pathologically, 53 of the patients had transitional cell carcinoma and 1 had papilloma. Six patients had a past history of bladder tumor. Simultaneous bladder tumor was identified in 10 cases. Vesical recurrence was observed in 5 cases. Total nephroureterectomy with bladder cuff resection was employed as the surgical method in 21 cases, and total nephrectomy without bladder cuff resection in 11 patients. The actual five-year survival rate was 53% for all the patients; 52% for patients with renal pelvic tumors, 75% for those with ureteral tumors and 15% for those with renal pelvic and ureteral tumors. The patients who received nephroureterectomy had a postoperative survival rate similar to that of those who received nephroureterectomy with bladder cuff resection. A simultaneous bladder tumor lowered the survival rate.

Aged↗
PubMed1987

Immunohistochemical demonstration of metallothionein in the rat prostate.

Metallothionein in the rat prostate was demonstrated by using an indirect immunoperoxidase technique. Strong staining was found mainly in the supranuclear area of the cytoplasm of the glandular epithelium in the dorsal and the lateral glands. Diffuse cytoplasmic staining and nuclear staining were found with less frequency. Secretory granules were found in the lumen with various intensities of staining. Most of the epithelial cells in the ventral lobes and the coagulating glands were negatively stained. Immunoreactive cells were found sporadically. Two types of immunoreactive cells, round cells and spindle-shaped cells, were scattered in the stroma. Vascular endothelial cells, red blood cells, and smooth muscle cells were negatively stained. These results suggest the synthesis and secretion of metallothionein in the rat prostate.

Animals↗
PubMed1987

[Therapy of renal cell carcinoma. 3. Interferon therapy].

Human lymphoblastoid interferon (HLBI-alpha) or recombinant human leukocyte interferon (HLIF-alpha) was administered to ten patients suffering from renal cell carcinoma at a daily dose of 5 X 10(6) units. The efficacy of interferon was assessed in nine patients who had received HLBI-alpha or HLIF-alpha for more than eight weeks. One patient (11%) demonstrated complete response (CR), three patients (33%) showed no change and five patients (56%) continued to have progressive disease. CR was obtained after 30 weeks under HLBI-alpha and FT-207 combination therapy. The main side effects were fever, anorexia, general fatigue and hematologic toxicities. Cessation of interferon therapy due to side effects was necessary in three patients. In conclusion interferon is one of the most valuable agents in the treatment of renal cell carcinoma.

Adult↗
PubMed1986

Cervical disk injuries in athletes.

Cervical disk injuries are defined as a cervical injury associated with neurological deficits, radicular symptoms, or radiological evidence of disk degeneration, but not with a fracture or a dislocation of the cervical spine. Thirty cases covering the period from July 1982 to June 1984 were analyzed, and the following findings are presented. Fifty percent of the injuries were sustained in American football. Sixty percent of radicular signs and symptoms were from the fourth and fifth cervical root. The roentgenographic changes were most common at the fourth and fifth intervertebral disk spaces. Most of the cases responded satisfactorily to a simple cervical collar and cervical traction. The athletes who presented radicular signs and symptoms required 5 months to return to full sports activities, and 60% of these had some residual symptoms after completion of treatment. The athletes who had a block vertebra of the cervical spine were not suited for contact sports. Recognition of the seriousness of cervical disk injuries in athletes is emphasized.

Adult↗
PubMed1986

A comparative study of seminal trace elements in fertile and infertile men.

Fourteen kinds of trace elements were analyzed in the semen of 22 fertile men and 69 infertile men by means of inductively coupled plasma optical emission spectroscopy. Ca had the highest concentration, and the second and third highest concentrations were Zn and Mg, respectively. The concentrations of Ca, Cr, Mg, Pb, Sr, and Zn were almost the same between fertile and infertile men. Ni had a lower concentration in infertile than in fertile men. Many trace elements, such as Al, Cd, Cu, Mg, Mn, Mo, Sn, and Zn, had significantly higher concentrations in infertile men with normozoospermia than in fertile men. There was a significantly positive correlation between Zn and Mg levels in fertile and infertile men.

Adult↗
PubMed1985

Ectopic ureter presenting with epididymitis in childhood: report of 5 cases.

We report 5 cases of an ectopic ureter opening into the seminal tract. All of the patients presented with the clinical features of acute or chronic epididymitis. Our experience has shown that the rare occurrence of epididymitis in prepubertal children necessitates a complete urological evaluation and that an underlying urological problem, including an ectopic ureter, should be sought.

Child↗