Biomedical subjects

T Hida

Publications and source records attributed to T Hida.

At least 73 records · Page 4Linked to original sources

PubMed1997

Subretinal fluid drainage with the erbium:YAG laser in rabbit eyes.

BACKGROUND AND OBJECTIVE: To evaluate the efficacy and safety of the erbium:yttrium-aluminum-garnet (Er:YAG) laser for choroidotomy as a means of performing external drainage of subretinal fluid with less risk of choroidal bleeding. MATERIALS AND METHODS: The authors tested this application in a rabbit model of retinal detachment by evaluating the effects of Er:YAG laser energy on the bare choroid at various energy settings (1, 2, 3, or 5 mJ/pulse) and repetition rates (2, 4, 10, or 30 Hz). RESULTS: Although the choroid was not perforated at low energy and frequency settings, choroidotomy was successfully achieved as energy and repetition rate were increased. Through higher energy levels per pulse and higher repetition rates, choroidotomy was achieved at lower total energy levels. No retinal damage was detected after laser choroidotomy. Choroidal bleeding was noted in 2 of 97 eyes; however, no subretinal hemorrhage occurred. CONCLUSION: These results indicate that the Er:YAG laser may be a clinically useful tool for retinal reattachment surgery.

Animals↗

PubMed1997

[Elucidation of the mechanism of retinal degeneration and regeneration and the prospects for its clinical application].

In order to obtain the basic knowledge necessary to develop therapeutical intervention for blindness due to the damaged retina and optic nerve, the mechanism of retinal degeneration and regeneration in an amphibian model, Cynops pyrrhogaster, was studied. In the retinal degenerative process following enucleation and reimplantation of the eye ball, evidence was found for active cell death of neural retinal cells. As the degeneration proceeded, Musashi, an ribonucleic acid (RNA)-binding protein, started its expression in the daughter cells of proliferating retinal pigment epithelium (RPE) cells, messenger RNA (mRNA) expression of proneural genes with basic helix-loop-helix motif was then detected in the newly developing retina. These results suggest that transdifferentiation of RPE cells to neural retina involves at least partial cascade, if not entirely, of neural induction from uncommitted ectodermal tissue. Search for genes that are required for transdifferentiation of RPE cells to neural retinal cells, in addition to those mentioned above, will provide the basic knowledge for successful retinal transplantation and retinal regeneration in higher vertebrates.

Amphibians↗

PubMed1996

[Clinical study of occupational uroepithelial cancer].

We studied 438 persons who were engaged in the production and use of aromatic amines (benzidine sulfate, beta-naphthylamine, alpha-naphthylamine and dianisidine). Among these 438 persons, 88 new cases of occupational uroepithelial cancer had occurred from 1949 to 1995. The incident rate of occupational uroepithelial cancer was 20.1%. The average exposure period of these 88 cases to the aromatic amines was 7.40 years (range, 0.75-26.75), and the incidence rate of tumors increased with the length of exposure to aromatic amines. The average latent period was 26.79 years (range, 1.33-48.50), and the average age of first onset was 52.59 (range, 24-79). Recently it has been determined that the longer the latent period, the older the age of first onset. Of these 88 cases, the tumor sites were bladder in 67 cases (76.1%) and upper urinary tract (renal pelvis and/or ureter) in 5 cases (5.7%). The other 16 cases (18.2%) were the bladder and upper urinary tract. The screening examination for chemical workers using urinary cytology was begun in 1962. In our cases, urine cytology was a useful method for diagnosing occupational uroepithelial cancer. As for initial treatment of the 88 cases, transurethral surgery was most frequently performed, that is on 58 cases (65.9%). However, eight cases (9.1%) had to undergo a total nephroureterectomy, and six cases (6.8%) had a total cystectomy. Recurrence was observed in 61 cases (69.3%) out of the 88 patients with an average of 1.81 times. The other organic cancers developed in 39 cases (8.9%) out of 438 workers who were exposed to aromatic amines and in 8 cases out of 88 patients (9.1%). Prognosis of the 88 patients is that, the number of alive and dead is 51 (58.0%) and 37 (42.0%) respectively on December 31, 1995. Twenty-eight patients (31.8%) died of uroepithelial cancer, and five patients (5.7%) died of other organic cancers. The survival rates of 5, 10, 15 and 20 years was 87.9%, 74.0%, 65.9% and 56.3%, respectively. From these results, patients with occupational uroepithelial cancer and workers who are exposed to aromatic amines should undergo long term observation.

2-Naphthylamine↗

PubMed1996

Breast cancer growth is inhibited by vasoactive intestinal peptide (VIP) hybrid, a synthetic VIP receptor antagonist.

Breast cancer vasoactive intestinal peptide (VIP) receptors were characterized. Using in vitro autoradiographic techniques, 125I-labeled VIP bound with high affinity to breast biopsy sections. 125I-labeled VIP bound specifically to give breast cancer cell lines examined using receptor-binding techniques. Specific 125I-labeled VIP binding to MDA-MB-231 cells was inhibited with high affinity by VIP and pituitary adenylate cyclase-activating polypeptide (IC50, = 2 nM) and with moderate affinity by the VIP hybrid (IC50 = 0.5 microM). VIP elevated the cAMP in a dose-dependent manner, and VIP hybrid (10 microM) inhibited the increase in cAMP caused by VIP. Using Northern blot analysis, VIP (10 nM) stimulated c-fos and c-myc mRNA, and the increase caused by VIP was reversed by the VIP hybrid. The VIP hybrid inhibited breast cancer growth in vitro and in vivo using nude mice bearing breast cancer xenografts. These data suggest that the VIP hybrid is a breast cancer VIP receptor antagonist.

Animals↗

PubMed1996

Retrospective survey of surgical outcomes on rhegmatogenous retinal detachments associated with atopic dermatitis.

OBJECTIVE: To determine the clinical features and surgical outcomes of retinal detachment associated with atopic dermatitis. METHODS: One hundred twenty-one eyes of 98 patients with atopic dermatitis and rhegmatogenous retinal detachment were surgically treated and followed up for 1 year or longer. Fundus examination data on retinal breaks and detachment, and follow-up data on anatomic reattachment were obtained and compared between phakic and aphakic eyes using the chi 2 test. RESULTS: Breaks were often multiple and located at the ora serrata (72%) and in the ciliary epithelium (15%). Irregularly shaped breaks (13.5%) and giant breaks (16%) also were seen. Most detachments (71%) were localized and shallow. No significant difference was identified with or without a history of cataract surgery. The prognosis after the initial surgery (reattachment rate, 72%) was unfavorable because of new break formation, but the results of reoperation (reattachment rate, 93%) were as successful. CONCLUSIONS: Patients with atopic dermatitis may have an abnormality in the anterior retina and ciliary epithelium that predisposes to retinal detachment. Findings suggest a possible traumatic trigger and the need to perform an encircling scleral buckle procedure with widespread retinopexy initially in these patients.

Adolescent↗

PubMed1996

PACAP stimulates c-fos mRNAs in small cell lung cancer cells.

The effects of PACAP on c-fos mRNA using small cell lung cancer (SCLC) cell was investigated. PACAP-27 (100 nM) increased c-fos mRNA 5-fold using NCI-N417 cells. The increase was concentration dependent with 0.1 nM PACAP-27 half maximally increasing c-fos mRNA. Also the increase in c-fos mRNA caused by PACAP was time dependent; being maximal after 1 hour and returning to basal values after 4 hours. PACAP-38 but not PACAP(28-38) increased c-fos mRNA. One uM PACAP(6-38), a PACAP receptor antagonist, inhibited the increase in c-fos mRNA caused by 1 nM PACAP. These data indicate that PACAP stimulates nuclear oncogene expression in SCLC cells.

Carcinoma, Small Cell↗

PubMed1996

Modification of chemo-radiosensitivity of a human lung cancer cell line by introduction of the glutathione S-transferase pi gene.

Recent studies have suggested that glutathione S-transferase pi (GST-pi) may play a role in determining tumor sensitivities to cytotoxic drugs. In order to better understand the role of this enzyme in chemo- and/or radioresistance of lung cancer cells, we examined whether introduction of GST-pi cDNA into a chemo- and radiosensitive lung cancer cell line altered its sensitivities to various chemotherapeutic agents and/or ionizing radiation, which are often used in the management of lung cancers. Modestly increased resistance of the GST-pi transfectants preferentially to sublethal damage caused by ionizing radiation as well as to adriamycin (ADM) was observed. In contrast, resistances to cisplatin (CDDP), etoposide (VP-16), irinotecan hydrochloride (CPT-11) and paclitaxel were virtually unaltered. These results suggest that GST-pi may not play a major role in chemo- and radioresistance of lung cancers, although it could afford selective and limited protection against ADM- and ionizing radiation-induced damage.

Antineoplastic Agents↗

PubMed1996

[Vitrectomy in Coats' disease].

Four eyes of four patients with Coats' disease underwent vitrectomy because of exudative or tractional detachments involving the macula or premacular fibrosis. All cases had gelatinous vitreous and had no complete posterior vitreous detachment. The exudates decreased and the retina reattached after removing vitreous traction and coagulating abnormal vessels with endodiathermy and not removing subretinal fluid in 3 eyes with retinal detachment. In one eye with tractional detachment, retinal breaks were found beneath the proliferative membrane during the initial vitrectomy procedure. This eye needed multiple operations because of recurrent traction by the remaining peripheral vitreous. Exudation into the vitreous and vitreous traction may cause mutual progression in these eyes, and vitrectomy is an effective treatment, although there are difficulties in removing vitreous traction completely.

Adolescent↗

PubMed1996

Reduced expression of DNA topoisomerase II confers resistance to etoposide (VP-16) in small cell lung cancer cell lines established from a refractory tumor of a patient and by in vitro selection.

Cell lines, LC-5 and LC-172, were established from tumors of a small cell lung cancer patient prior to and after combination chemotherapy including etoposide (VP-16), when drug-resistant tumors developed in relapse. A VP-16-resistant cell line, LC-172/VP, was selected from the LC-172 cells in culture in multiple steps with VP-16. LC-172 cells were 3.5-fold resistant to VP-16 in growth inhibition, and 3.3-fold resistant to adriamycin as compared with LC-5 cells. LC-172/VP cells showed large differences in cross-resistance to topoisomerase II-targeting drugs such as VP-16, 200-fold, adriamycin, 10-fold, and MST-16, 4.3-fold; the cells were moderately refractory, 5.5-fold, to vincristine. VP-16 accumulation in the cells was similar in three cell lines. Topoisomerase II unknotting activity was reduced 7- to 10-fold in LC-172/VP and 1.5- to 2-fold in LC-172 cells compared with LC-5 cells, while relaxing activity of topoisomerase I appeared to be unchanged. Topoisomerase II protein was also reduced 5- to 10-fold in LC-172/VP and marginally so in LC-172 cells. Topoisomerase II alpha and II beta were each reduced 10-fold and 2-fold, respectively, in LC-172/VP cells, while they were both slightly decreased (-1.5-fold), respectively, in LC-172 cells compared with LC-5 cells. No apparent alteration in ATP requirement for catalytic activity and in sensitivity to VP-16 was observed for topoisomerase II from the three cell lines. Taken together, these results suggested that resistance to VP-16 in LC-172 and LC-172/VP is associated with a quantitative reduction in expression of topoisomerase II alpha of the parental type.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1995

A novel type of retinoic acid receptor antagonist: synthesis and structure-activity relationships of heterocyclic ring-containing benzoic acid derivatives.

A new series of heterocyclic ring-containing benzoic acids was prepared, and the binding affinity and antagonism of its members against all-trans-retinoic acid were evaluated by in vitro assay systems using human promyelocytic leukemia (HL-60) cells. Structure-activity relationships indicated that both an N-substituted pyrrole or pyrazole (1-position) and a hydrophobic region, with these linked by a ring system, were indispensable for effective antagonism. Among the compounds evaluated, optimal antagonism was exhibited by 4-[4,5,7,8,9,10-hexahydro-7,7,10,-10-tetramethyl-1-(3- pyridylmethyl)anthra[1,2-b]pyrrol-3-yl]benzoic acid (31), 4-[4,5,7,8,9,10-hexahydro-7,7,10,10-tetramethyl-1-(3-pyridylmethyl)-5- thiaanthral[1,2-b]pyrrol-3-yl]benzoic acid (40), and 4-[4,5,7,8,9,10-hexahydro-7,7,10,10-tetramethyl-1-(3- pyridylmethyl)anthra[2,1-d]pyrazol-3-yl]benzoic acid (55), all of which possess a 3-pyridylmethyl group at the five-membered ring nitrogen atom.

Benzoates↗

PubMed1995

Long-term follow-up of patients with familial subepithelial amyloidosis of the cornea.

PURPOSE: To investigate the clinical course of patients with familial subepithelial amyloidosis of the cornea (FSA). METHODS: The authors retrospectively investigated the clinical course of seven Japanese patients with FSA. Corneal specimens obtained at the time of keratoplasty were examined histopathologically. RESULTS: The mean follow-up period was 20.6 years, including four patients followed for more than 25 years. In all patients, the initial symptoms of photophobia and epiphora started in the first decade of life. All except one patient had their first keratoplasty before 30 years of age. The seven Japanese patients with FSA had a total of 35 keratoplasties, each of which was followed by a severe recurrence of disease. In each patient, subepithelial haziness developed in the graft within 1 year of keratoplasty (mean, 7.9 months). Amyloid deposition typically recurred within a few years (mean, 26.6 months) followed by a deterioration of vision. There was a high incidence of postkeratoplasty complications such as wound dehiscence, glaucoma, and cataract. Histopathologic findings demonstrated that, in the early phase of recurrence, amyloid was deposited between the basal cell of the epithelium and Bowman's layer. CONCLUSION: Patients with FSA have ocular symptoms with a deterioration in vision from an early decade of life. Conventional surgical approaches were complicated by subepithelial haziness in the first postoperative year, which was followed by a severe recurrence in each patient. New surgical approaches may be indicated in FSA.

Adult↗

PubMed1995

TAN-1323 C and D, new concanamycin-group antibiotics; detection of the angiostatic activity with a wide range of macrolide antibiotics.

We detected potent angiostatic activity in a MeOH extract from the mycelia of microbial strain S-45628 in the chick chorioallantoic membrane (CAM) assay. The producer was taxonomically characterized as Streptomyces purpurascens. Active principles designated TAN-1323 A-D were isolated and determined to be 18-membered macrolide antibiotics; components C and D are new members of this group, while components A and B are identical to concanamycins C and A, respectively. When tested in the CAM assay, components B and D gave huge avascular zones at the extremely low doses of 10-100 ng/disk, although components A and C showed far weaker activity due to their preferential tissue-damaging effect on the CAM. The discovery that these 18-membered macrolide antibiotics are angiostatic substances prompted us to examine other types of macrolide antibiotics, leading to the discovery that 16-membered macrolide antibiotics such as bafilomycin C1, tylosin and leucomycin also show angiostatic activity on the CAM. Thus, angiostatic potential is widely distributed among macrolide antibiotics. The mechanism of action of these macrolide antibiotics is also discussed.

3T3 Cells↗

PubMed1995

TAN-1511 A, B and C, microbial lipopeptides with G-CSF and GM-CSF inducing activity.

The microbial lipopeptides, TAN-1511 A, B and C, were isolated from the culture broth of Streptosporangium amethystogenes subsp. fukuiense AL-23456. Their structures were elucidated on the basis of their reactions and spectroscopic analyses. These lipopeptides were mixtures of molecules having different lengths of fatty acids. The metabolites stimulated the proliferation of bone marrow cells from BALB/c female mice at very low concentrations (concentration giving 30% increase: A and B, 0.313 ng/ml; C, 1.25 ng/ml). We confirmed that chemically synthesized TAN-1511 A analogue [(2R,6R)-2-tetradecanoylamino-6,7- bis(hexadecanoyloxy)-4-thiaheptanoyl-Gly-Gly-Gly-Glu-Thr-Thr -OH] stimulated the proliferation of bone marrow cells in a manner similar to that of natural TAN-1511 A. This analogue induced the secretion of both granulocyte colony stimulating factor (G-CSF) and granulocyte-macrophage colony stimulating factor (GM-CSF), and potentiated the generation of Gr-1 positive cells in the bone marrow cell culture. Moreover, it effected the G-CSF mediated restoration of granulocytopoiesis in a murine leukopenia model.

Amino Acid Sequence↗

PubMed1995

Synthesis and biological activities of TAN-1511 analogues.

TAN-1511 analogues were synthesized and their effects on the proliferation of bone marrow cells were examined. To exert potent activity the following conditions are necessary: the configuration of the 2-amino-6,7-dihydroxy-4-thiaheptanoic acid moiety must be (2R,6R), long chain acyl groups (C14 to C18) must be bound to both hydroxyl groups, the amino group must be free or acylated with the long chain fatty acid (ca. C14) and the peptide moiety must have glutamic acid as a component. Among the synthesized compounds, trisodium (2R,6R)-2-amino-6,7-bis (hexadecanoyloxy)-4-thiaheptanoyl glycyl glutamyl glutamate, which has improved solubility, was effective in experimental leukocytopenia in mice.

Amino Acid Sequence↗

PubMed1994

Novel role of vitamin K2: a potent inducer of differentiation of various human myeloid leukemia cell lines.

When myeloblastic ML1 cells were cultured in the presence of Vitamin K2 (menaquinone, VK2), the population of cells capable of reducing NBT increased to 83.5% at low VK2 concentration of 1 microM, indicating VK2 induces cellular differentiation. VK2 also exerted differentiation-inducing action on histiocytic U937 and promyelocytic HL60 cell lines. None of these effects were observed with Vitamin K1 (phylloquinone, VK1), suggesting the geranylgeranyl group of the side chain of VK2 to be essential to these effects. Combinations of VK2 with other differentiation-inducers such as interferon-gamma, retinoic acid, or camptothecin additively or synergistically induced the differentiation of HL-60 cells. These results suggest that VK2 may safely be used in differentiation therapy in combination with other inducers.

Cell Differentiation↗

PubMed1994

Serum glutathione S-transferase-pi level as a tumor marker for non-small cell lung cancer. Potential predictive value in chemotherapeutic response.

BACKGROUND: Resistance to chemotherapeutic agents is a major problem in non-small cell lung cancer (NSCLC) chemotherapy, and recent studies have indicated that glutathione S-transferase-pi (GST-pi) may play an important role in the resistance of cancer cells to alkylating agents that include platinum compound. METHODS: GST-pi in serum of 121 patients with NSCLC was measured by a sandwich enzyme-linked immunosorbent assay, and the serum concentrations of carcinoembryonic antigen (CEA), squamous cell carcinoma (SCC) antigen, and neuron-specific enolase (NSE) were also examined. Serum levels of these tumor markers were also evaluated in relation to therapeutic response in 69 patients who received combination chemotherapy with platinum compound. RESULTS: Fifty of 121 patients with NSCLC (41.3%) showed elevated serum GST-pi levels above a cutoff value of 34.8 ng/ml (mean + two standard deviations in 30 healthy control subjects). The positive rate of GST-pi in patients with NSCLC was higher than those of CEA (37.2%), SCC (15.7%), and NSE (14.9%). The mean pretreatment GST-pi level was significantly lower in patients with a partial response to chemotherapy than in those with no response (26.9 +/- 11.3 ng/ml versus 38.8 +/- 16.7 ng/ml; P < 0.003). Among patients with elevated levels of pretreatment serum GST-pi, only 13.8% (four of 29) responded to the combination chemotherapy, whereas partial response was observed in 40.0% of patients (16 of 40) with serum GST-pi concentration below the cutoff level (P < 0.02). Neither CEA, SCC, nor NSE showed such a relationship. CONCLUSIONS: The serum GST-pi level may have limited value as a tumor marker for NSCLC: Interestingly, pretreatment serum GST-pi levels may be a useful parameter for predicting therapeutic response to combination chemotherapy regimens that include platinum compound.

Adult↗

PubMed1994

Gomisin A, a lignan component of Schizandora fruits, inhibits development of preneoplastic lesions in rat liver by 3'-methyl-4-dimethylamino-azobenzene.

The effects of gomisin A, a lignan component of Schizandra fruits, on development of preneoplastic lesions in the liver after a short-term (3 weeks) feeding of 3'-methyl-4-dimethyl-aminoazobenzene (3'-MeDAB) to male Donryu rats were investigated, and compared with the effects of phenobarbital. Gomisin A inhibited both increases of the level of glutathione-S-transferase placental form (GST-P) and the number and size of GST-P positive foci in the liver increased after treatment with 3'-MeDAB. Moreover, although the population of diploid nuclei was increased and that of tetraploid nuclei was decreased by pretreatment with 3'-MeDAB, gomisin A returned this to near the normal ploidy pattern. But phenobarbital increased the level of GST-P and the number and size of GST-P positive foci with little affect on the ploidy population changed by 3'-MeDAB. Thus, the effect of gomisin A on hepatocarcinogenesis was inhibitory in contrast with that of phenobarbital. This study suggests that gomisin A is a candidate for a chemopreventive drug inhibiting the promotion process in hepatocarcinogenesis.

Animals↗

PubMed1994

Ectopic expression of c-kit in small-cell lung cancer.

Accumulating evidence suggests that c-kit plays an important role in the regulation of growth of at least 3 lineages of stem cells, while only very limited data are available on the development of human solid tumors. Our recent studies have shown that c-kit transcripts are expressed in a very restricted sub-set of human solid tumors such as small-cell lung cancer (SCLC). We have also conducted an immunohistological study on in situ localization of the c-kit protein in various human solid tumors as well as in corresponding fetal and adult normal tissues. No c-kit expression was detected in normal bronchial epithelial cells or pneumocytes in lung parenchyma of human fetal and adult specimens, indicating that the c-kit protein is aberrantly expressed in lung-cancer cells. We also found that significant chemotactic response as well as moderate in vitro cell growth occurred in SCLC cell lines upon addition of recombinant human stem-cell factor.

Adenocarcinoma↗