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T Baba

Publications and source records attributed to T Baba.

At least 361 records · Page 20Linked to original sources
PubMed1991

Differentiation of the basal cell epithelioma-like changes overlying dermatofibroma.

Epidermis overlying dermatofibroma rarely displays basal cell epithelioma-like changes (BCE-like changes). Based on the histopathological findings, whether BCE-like changes are induced by dermal lesion or adnexal regression secondary to the solid fibrotic growth remains to be explored. From the standpoint of differentiation, we examined the BCE-like changes overlying dermatofibroma, normal epidermis, and hair follicles. PNA and two kinds of anti-keratin monoclonal antibodies were used to detect markers for epidermal differentiation. When PNA and anti-keratin monoclonal antibody (34betaB4) were used, no difference was observed in the staining patterns among BCE-like changes, hair follicles or normal basal cells. With the other anti-keratin antibody (34betaE12), BCE-like changes and normal basal cells were recognized, though the hair matrix was not. Thus the results obtained indicate that normal basal cells show the most similar differentiation to BCE-like changes.

Antibodies, Monoclonal↗
PubMed1991

HeLaTG cells have mitochondrial DNA inserted into the c-myc oncogene.

To determine whether mitochondrial DNA (mtDNA) fragments found within the nucleus are transcribed, we have differentially screened a HeLaTG cDNA library. A clone that hybridized to mtDNA as well as to c-myc was identified. Analysis of the cDNA disclosed that it contained a mtDNA sequence, encoding cytochrome-c oxidase subunit III (coxIII) that was contiguous with and 5' of a c-myc sequence corresponding to part of exon 2 and exon 3. Hybridization of ScaI-digested DNA with a 1.05 kb c-myc probe revealed a unique band in HeLaTG cells, as well as a band common to HeLaTG and 13 other cell types examined. Solution hybridization of HeLaTG RNA with a radiolabeled, single-stranded cDNA probe containing the coxIII-c-myc junction demonstrated a nuclease-resistant band that matched the full length of the junctional cDNA probe. A smaller band that equaled the size of the c-myc portion alone was also detected. Only the smaller band coinciding with the c-myc sequences was protected from nuclease digestion by RNA from other cells. When a radiolabeled probe synthesized in the opposite orientation was used, nuclease-resistant bands equal in length to the coxIII portion of the probe were detected after hybridization with RNA from all cells. These results indicate that insertion of mtDNA fragments into nuclear genes occurs and that subsequent transcription of a 'chimaeric' or 'fusion' mRNA containing both mitochondrial and nuclear sequences can ensue.

Base Sequence↗
PubMed1990

Acrosin biosynthesis in meiotic and postmeiotic spermatogenic cells.

It has been widely accepted that mammalian sperm acrosin is first synthesized only in the postmeiotic stages of spermatogenic cells. In this study, we carried out Northern blot analysis of RNAs prepared from purified populations of mouse spermatogenic cells. The acrosin mRNA was obviously found in meiotic pachytene spermatocytes, and the mRNA content markedly increased in postmeiotic round spermatids. Also, the acrosin mRNA in pachytene spermatocytes was functionally associated with polysomes. These results provide evidence that acrosin biosynthesis is already started in meiotic cells and continues through the early stages of spermiogenesis.

Acrosin↗
PubMed1990

Increased therapeutic efficacy of intra-arterial carboquone chemotherapy on a limb tumor in rats, by using an acidic vehicle adjusted with lactate.

We previously reported that the cytotoxicity of carboquone (CQ) was potentiated in vitro and in vivo under acidic conditions. In this study, an acidic vehicle adjusted with lactate at various low pHs was used for CQ intra-arterial (i.a.) injection, in order to enhance the antitumor effects of i.a. CQ chemotherapy. Treatments were evaluated in Wistar/KA rats bearing a limb tumor 5 days after the inoculation of 3 x 10(6) syngeneic RBT-1 tumor cells into the hind limb. In chemotherapy experiments using an intrafemoral injection of CQ at 1.5 mg/kg in phosphate-buffered saline (PBS, pH 7.4) or in an acidic vehicle at pH 5.0 or 6.0, the antitumor effects seen in rats given CQ in acidic vehicles, evaluated by tumor weight 14 days after treatment, were significantly greater than that seen in rats given CQ in PBS. There were no significant differences either in changes of body weight or in the number of leukocytes after treatment between the groups given CQ in PBS and in an acidic vehicle at pH 6.0. Although in the group given CQ at 2.0 mg/kg in PBS, the antitumor effect was the same as that observed in rats given CQ at 1.5 mg/kg in an acidic vehicle at pH 6.0, the side effects observed in the former group were much severer than in the latter group. These data suggest that the antitumor effect of i.a. CQ chemotherapy can be potentiated by using an acidic vehicle.

Animals↗
PubMed1990

Newly identified type of beta actin reduces invasiveness of mouse B16-melanoma.

Low metastatic parent B16 melanoma and isolated B16-F1 cell lines have a third actin designated as beta m(Ax:previously). beta m actin is scantily or not at all detected in highly metastatic cell lines, such as B16-F10 and BL6. To directly assess the physiological role of beta m in phenotypic changes of B16 melanoma, we transfected expression plasmids of beta m into B16-F10 cells. The actin expressed in the transfectants is located largely in cytoskeletal fractions. The transfectants exhibited a larger number of stress fibers and a lower invasiveness than did the recipient cells. Thus, beta m actin plays an important role in the organization of actin stress fibers, the result being a decrease in invasiveness of B16 melanoma.

Actins↗
PubMed1990

Systemic chemotherapy in tumor-bearing rats using high-dose cis-diamminedichloroplatinum(II) with low nephrotoxicity in combination with angiotensin II and sodium thiosulfate.

Systemic chemotherapy using high-dose DDP and its antidote, STS, was combined with the AT-II-induced hypertension method and evaluated for efficacy against s.c. tumors in rats. After i.v. infusion of DDP plus AT-II for 5 min, STS was administered i.v. over a further 5 min. The rats treated with this combination chemotherapy showed normal levels of BUN and serum creatinine 4 days after the treatment, although most rats given i.v. STS after DDP without AT-II showed severe nephrotoxicity. The absence of obvious nephrotoxicity in AT-II-combined chemotherapy using i.v. DDP plus post-administered STS can be explained by a transient inhibition of DDP-delivery to the kidney during the AT-II-induced hypertension. The anti-tumor effect of this modified therapy, evaluated by inhibition of tumor growth, was superior to other treatments, as follows: concomitant i.v. administrations of DDP and STS; i.v. DDP, with or without AT-II. The improvement in anti-tumor effect of this combination therapy is explained by the delayed neutralization of active DDP by STS at the tumor site and the selective enhancement of DDP delivery to the tumor tissue, as produced by AT-II. Thus, systemic chemotherapy using high-dose DDP induced no obvious nephrotoxicity and improved the anti-cancer effect in the case of concomitant administration of DDP plus AT-II and the time-delayed injection of STS.

Angiotensin II↗
PubMed1990

Augmented excretion of procathepsin L of a fos-transferred highly metastatic rat cell line.

We previously reported that v-fos transfer to a src-transformed rat 3Y1 cell line (SR-3Y1-2) enhanced lung metastasis accompanied with an increase in invasiveness. When analyzing factors relating to the high invasiveness, with special reference to typical lysosomal proteases (cathepsins), involving degradation of stroma, we found that the excretion of procathepsin L was significantly larger in the fos-transferred highly metastatic cell line (fos-SR-3Y1-202) than that in the recipient cell lines. The cathepsin D-induced enzyme activity of the excreted procathepsin L in fos-SR-3Y1-202 was about 4 and 13 fold that of SR-3Y1-2 and 3Y1, respectively. The increase in the excretion of procathepsin L from fos-SR-3Y1-202 may play a role in the high invasiveness induced by transfer with the v-fos oncogene.

Animals↗
PubMed1990

Comparison of the renal effects of dilevalol and carteolol in patients with mild to moderate essential hypertension.

The effects of 6 weeks of treatment with dilevalol 100 mg once daily, or carteolol 10 mg once daily, on renal blood flow (RBF), glomerular filtration rate (GFR) and total renal vascular resistance (TRR) were studied in 10 patients with mild-to-moderate essential hypertension in a randomised cross-over experiment. Both drugs lowered the systolic and diastolic blood pressures to a similar extent without altering the heart rate. Carteolol non-significantly decreased RBF by 9.2% and GFR by 12.3% without altering. TRR, whereas dilevalol produced a significant reduction in TRR by 13.2% (p less than 0.05), a non-significant decrease in RBF by 4.6% and no change in GFR. Neither drug changed plasma osmotic pressure, serum total protein concentration, electrolytes or plasma aldosterone concentration. Plasma renin activity tended to be lower in the dilevalol phase as compared to the carteolol phase. The results suggest that dilevalol may cause a greater decrease in TRR and less reduction in GFR when compared to carteolol in patients with mild-to-moderate essential hypertension. The difference in the renal effects might be due to the difference in the potency of vasodilatory properties of both drugs at the doses applied.

Adult↗
PubMed1990

Renal effects of nicardipine, a calcium antagonist, in hypertensive type 2 (non-insulin-dependent) diabetic patients with and without nephropathy.

The renal effects of oral maintenance doses of nicardipine 60-120 mg/day have been studied in 18 hypertensive patients with Type 2 (non-insulin-dependent) diabetes mellitus: 6 with normoalbuminuria (urinary albumin excretion rate, AER less than 20 micrograms.min-1, Group A); 6 with incipient nephropathy, (AER 20-200 micrograms.min-1, Group B); and 6 with overt nephropathy (AER greater than 200 micrograms.min-1, Group C). Treatment for 4 weeks significantly lowered the systolic and diastolic blood pressures and reduced total renal vascular resistance in all three groups. Nicardipine increased renal blood flow significantly in Group C and slightly in Group B, and had no effect in Group A. Glomerular filtration rate remained unchanged in all three groups. It significantly reduced AER and the fractional clearance of albumin in Group B, whereas AER in Groups A and C was not altered. Plasma renin activity, aldosterone concentration, osmotic pressure, serum total protein and albumin concentrations and haemoglobin A1c level were similar in the control and nicardipine phases in all three groups. The results suggest that nicardipine may preserve renal function whilst having a concomitant hypotensive action in hypertensive Type 2 diabetic patients with normoalbuminuria and incipient nephropathy, and that the drug may improve renal blood flow in patients with overt nephropathy. The effect of the drug on urinary albumin excretion may deserve further investigation.

Albuminuria↗
PubMed1990

Increased therapeutic effect on metastatic liver tumors in rats of two-route chemotherapy using cis-diamminedichloroplatinum (II) and its antidote, sodium thiosulfate, with temporary clamping of the abdominal aorta.

To improve the therapeutic effects of conventional "two-route chemotherapy" (TRC) comprising cis-diamminedichloroplatinum(II) (CDDP) given via the hepatic artery plus simultaneous i.v. sodium thiosulfate (STS) on metastatic liver tumors in rats, we combined TRC with aortic clamping at the supraceliac level. Treatments were evaluated in Wistar-King-Aptekman (WKA) rats bearing metastatic liver tumors 7 days after the inoculation of 10(6) syngenic RBT-1 (transitional-cell carcinoma) cells via the mesenteric vein. When 15 mg/kg CDDP was injected i.a. over 5 min, immediately followed by STS 1,580 mg/kg (200-fold the molar equivalent of 15 mg/kg CDDP) given i.v. over a further 5 min, the antitumor activity, evaluated by the number of tumor nodules present 12 days after treatment, was superior to that of conventional TRC (15 mg/kg i.a. CDDP plus simultaneous administration of 1,580 mg/kg i.v. STS), but the blood urea nitrogen (BUN) level was highly elevated (63.6 mg/dl). With aortic clamping for 7.5 min during CDDP administration and the first half of STS treatment, the TRC consisting of CDDP plus delayed STS (modified TRC) exhibited a further improvement in antitumor activity, with no nephrotoxicity (BUN, 17.1 mg/dl). Although the antitumor activity of 3 or 5 mg/kg i.a. CDDP was also increased by aortic clamping, in animals with normal BUN levels the survival of those treated with modified TRC was greater than that of rodents given 3 mg/kg i.a. CDDP with aortic clamping; however, the former was the same as that of animals given 5 mg/kg i.a. CDDP with aortic clamping whose BUN levels were elevated (31.2 mg/dl). Loss of body weight, the decrease in WBC counts, and changes in the serum transaminase levels in rats given modified TRC were tolerable. The improved therapeutic effect of modified TRC can be explained as follows: during aortic clamping, (a) CDDP delivery to the kidney decreased by 96% and made feasible the delay in STS administration after CDDP without nephrotoxicity, and (b) CDDP retention in the liver was increased by 366%, as aortic clamping decreased the portal blood flow, thereby inhibiting the washout of CDDP from the liver.

Animals↗
PubMed1990

Magnetic resonance imaging of experimental rat brain tumors: histopathological evaluation.

Using RG-C6 glioma-transplanted rats, we studied precontrast and postcontrast magnetic resonance imaging, extravasation of Evans blue, and histology. In all rats, tumor was enhanced with gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA). The necrotic portion in the tumor, however, was not enhanced. Hemorrhage and hydrocephalus were clearly visualized on both the precontrast and postcontrast images. Blood-brain barrier-disrupted areas stained with Evans blue and areas enhanced with Gd-DTPA on magnetic resonance imaging were nearly consistent. It is suggested that the mechanism of brain tumor enhancement with Gd-DTPA on magnetic resonance imaging is simply related to the degree of alteration of the blood-brain barrier. The Gd-DTPA-enhanced magnetic resonance imaging, even with low magnetic field, is useful for the evaluation of size, shape, and location of experimental rat brain tumors.

Animals↗
PubMed1990

ADP-ribosylation of nonmuscle actin by component I of botulinum C2 toxin inactivates the ability to interact with unmodified actin.

Botulinum C2 toxin, elaborated by Clostridium botulinum types C and D, is composed of two dissimilar unassociated proteins, designated components I and II. Component I catalyzes ADP-ribosylation of nonmuscle beta- and gamma-actins but not of muscle alpha-actin. The maximal levels of ADP-ribosylation of the actin were about 1.0 mol of ADP-ribose/mol of actin. Sedimentation velocity analysis showed that ADP-ribosylated actin remained in a monomeric state even under polymerization conditions. In addition to the inactivation of self-polymerization ability, the ADP-ribosylated actin affected neither the initial rate nor the final extent of polymerization of unmodified actin as monitored by the increase in fluorescence intensity of N-pyrenyliodoacetamide-labeled actin. Electron microscopy revealed that no filaments or particles were formed from ADP-ribosylated actin in the conditions favorable for polymerization of unmodified actin; moreover, actin filaments produced from unmodified actin in the presence of ADP-ribosylated actin were not distinguishable from those from unmodified actin alone. These results indicate that the introduction of one ADP-ribose residue into the beta/gamma-actin molecule by component I inactivated the actin, preventing not only the self-assembly of the modified actins but also the interaction with unmodified actin.(ABSTRACT TRUNCATED AT 250 WORDS)

Actins↗
PubMed1990

Primary structure of mouse proacrosin deduced from the cDNA sequence and its gene expression during spermatogenesis.

In the present study, we identified cDNA clones of mouse acrosin from a testis lambda gt11 library. The deduced amino acid sequence indicates that mouse acrosin is initially synthesized as a single-chain polypeptide with a 16-residue signal peptide followed by a 23-residue light chain and then a 394-residue heavy chain; mouse acrosin zymogen contains 417 amino acid residues with a calculated molecular mass of 46,993 Da. The cDNA-derived sequence of mouse proacrosin shows a high degree of similarity with human and porcine proacrosins and major portions of bovine trypsin, including the active site residues, the recognition site for substrate, the location of 12 cysteine residues, and two potential N-glycosylation sites. The sequence homology suggests that mouse proacrosin is converted to a mature acrosin, which consists of the light and heavy chains with a combined molecular mass of 35,587 Da, by cleavage of the peptide bond between Arg23 and IIe24, and sequential removal of 23-, 26-, and 50-residue COOH-terminal segments. Using Northern blot analysis of RNAs from various mouse tissues, the acrosin gene transcript was present only in testis. The 1,800-base acrosin message was first detectable in 18-day-old testis. At the same time of testicular development, some of the acrosin mRNA was actually associated with polysomes. Also, in situ hybridization analysis suggests that the acrosin gene is expressed only in the round spermatid. Therefore, it is most likely that transcription of the mouse acrosin gene and subsequent translation of its mRNA first occur in the early stages of the round spermatid, and that the acrosin message is not under translational control.

Acrosin↗
PubMed1990

Renal effects of bunazosin, a new alpha 1-adrenoceptor blocker, in patients with mild-to-moderate essential hypertension.

Renal effects of 4-week fixed maintenance doses of bunazosin three times daily (2.0 mg t.i.d., n = 8) and propranolol (40 mg t.i.d., n = 8) were evaluated in patients with mild-to-moderate essential hypertension [World Health Organization (WHO) stages I and II]. Both bunazosin and propranolol decreased blood pressure (BP) significantly (p less than 0.05), but the magnitude of reduction in diastolic BP (DBP) was greater with bunazosin (p less than 0.05) than with propranolol. Bunazosin produced a nonsignificant increase in renal blood flow (RBF) by 14%, a significant increase in glomerular filtration rate (GFR) 11% (p less than 0.05), and a decrease in total renal vascular resistance (TRR) by 15% (p less than 0.05), whereas propranolol caused no significant changes in these parameters. Urinary sodium excretion rate and the fractional excretion of sodium were unchanged by either of the drugs. The results of this short-term study suggest that bunazosin may be a drug that will increase RBF and GFR and decrease TRR with a concomitant hypotensive action in patients with mild-to-moderate essential hypertension. Whether these renal functional effects of the drug would benefit such patients must be determined in long-term studies.

Adrenergic alpha-Antagonists↗