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K Wakamatsu

Publications and source records attributed to K Wakamatsu.

At least 19 recordsLinked to original sources
PubMed1996

Immunohistochemical expression of glutathione S-transferase-Pi can predict chemotherapy response in patients with nonsmall cell lung carcinoma.

BACKGROUND: Resistance to chemotherapy agents is a major problem in the treatment of patients with nonsmall cell lung carcinoma (NSCLC). 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, including cisplatin compounds. METHODS: The expression of GST-Pi in tissues obtained by bronchoscopic biopsy from 38 NSCLC patients was investigated immunohistochemically. These patients were treated with a combination of cisplatin-based chemotherapy and were evaluated to determine the relationship between GST-Pi expression and chemotherapy response. RESULTS: Of the 38 patients, 25 (66%) were GST-Pi-positive and 13 (34%) were negative. There was no significant correlation between GST-Pi expression and the clinicopathologic factors examined (age, sex, performance status, histology, differentiation grade, and stage). Of the 38 patients treated with cisplatin-based chemotherapy, 12 patients responded to chemotherapy (overall response rate, 32%). For the patients with negative GST-Pi expression, the response rate was 69% (9 of 13 patients). In the patients with positive GST-Pi expression, the response rate was 12% (3 of 25 patients). This difference was statistically significant (P=0.0012). CONCLUSIONS: The expression of GST-Pi in NSCLC patients was significantly related to response to cisplatin-based chemotherapy, and may be a useful predictor of chemotherapy response.

Aged↗
PubMed1996

Serum concentration of 5-S-cysteinyldopa in pediatric patients with giant pigmented nevi.

The serum concentrations of 5-S-cysteinyldopa (5-S-CD) in pediatric patients with giant pigmented nevi (GPN) were investigated and compared with those of pediatric patients with small- or medium-sized congenital nevi (CN), or non-melanocytic benign skin tumor (control group). Serum 5-S-CD levels in the GPN group (N = 21), particularly in patients less than 5 years old, were significantly higher (highest concentration 38.4, mean +/- S.D. 16.6 +/- 9.4 nmol/L) than those in the CN (N = 22) or control groups (N = 26). Serum 5-S-CD levels in the CN group were not significantly different from those in the control group. There was a significant correlation between the serum 5-S-CD level and size (surface area) of the GNP. There was a significant inverse correlation between the serum 5-S-CD level and age in the CN and control groups, but not in the GPN group. Serum 5-S-CD levels were transiently elevated immediately after treatment of patients with GPN with a combination of skin abrasion and cryotherapy with solid carbon dioxide. These results suggest that serum 5-S-CD levels in the GPN group reflected the 5-S-CD derived from GPN, particularly in patients less than 5 years old. This indicates that melanogenesis may be accelerated in infant patients in the GPN group.

Adolescent↗
PubMed1995

Antimelanoma effect of 4-S-cysteaminylcatechol, an activated form of 4-S-cysteaminylphenol.

Rational chemotherapy of malignant melanoma could be developed by taking advantage of the presence of melanogenic enzymes in melanoma cells. 4-S-Cysteaminylphenol (4-S-CAP) has been evaluated for melanocytotoxicity and antimelanoma effect. Although 4-S-CAP is selectively toxic to pigmented melanoma cells, it is not potent enough when applied as a single agent. To increase the efficacy of 4-S-CAP, we synthesized 4-S-cysteaminylcatechol (4-S-CAC), an activated form of 4-S-CAP, and compared its biochemical properties and antimelanoma effects with those of the isomers 3-S-cysteaminylcatechol (3-S-CAC) and 2-S-cysteaminyl-hydroquinone (2-S-CAH). 4-S-CAC was found to be a better substrate for melanoma tyrosinase than was L-3,4-dihydroxyphenylalanine, the natural catecholic substrate. 3-S-CAC was a poor substrate, whereas 2-S-CAH was not a substrate. 4-S-CAC was the most cytotoxic to three lines of melanoma cells in vitro, followed by 2-S-CAH and 3-S-CAC. When applied i.p. for 9 days at a dose of 100 mg/kg, 4-S-CAC.HCl, increased by 46-52% the life span of C57BL/6 mice inoculated i.p. with B16 melanoma; this effect was comparable to that of a 50 mg/kg dose of 5-(3,3-dimethyltriazenyl)-1H-imidazole-4-carboxamide. 3-S-CAC was marginally effective, whereas 2-S-CAH was toxic to the host. This systemic toxicity of 2-S-CAH reflected its susceptibility to autoxidation. Growth of B16 melanoma cells inoculated s.c. was significantly inhibited by i.p. administration of 4-S-CAC.HCl (200 mg/kg) for 5 days (P < 0.05). These results suggest that 4-S-CAC is a potent antimelanoma agent, the effect of which is mostly mediated through tyrosinase oxidation.

Animals↗
PubMed1995

Chemical characterization of hair melanins in various coat-color mutants of mice.

Mammalian melanins exist in two chemically distinct forms: the brown to black eumelanins and the yellow to reddish pheomelanins. Melanogenesis is influenced by a number of genes, the levels of whose products determine the quantity and quality of the melanins produced. To examine the effects of various coat-color genes on the chemical properties of melanins synthesized in the follicular melanocytes of mice, we have introduced new methods to solubilize differentially pheomelanins and brown-type eumelanins. We applied these and previously developed high-performance liquid chromatography and spectrophotometric methods for assaying eu- and pheomelanins to characterize melanins in various mutant mice: black, lethal yellow, viable yellow, agouti, brown, light, albino, dilute, recessive yellow, pink-eyed dilution, slaty, and silver. It was demonstrated that 1) complete solubilization of melanins in Soluene-350 is a convenient method to estimate the total amount of eu- and pheomelanins, 2) lethal yellow, viable yellow, and recessive yellow hairs contain almost pure pheomelanins, and 3) melanins from brown, light, silver, and pink-eyed black hairs share chemical properties in common that are characterized by partial solubility in strong alkali. We suggest that 1) the brown-type eumelanins have lower degrees of polymerization than the black-type eumelanins, and 2) slaty hair melanin contains a greatly reduced ratio of 5,6-dihydroxyindole-2-carboxylic acid-derived units as compared with black and other eumelanic hair melanins. These results indicate that our methodology, high-performance liquid chromatography and spectrophotometric methods combined, may be useful in chemically characterizing melanin pigments produced in follicular melanocytes.

Animals↗
PubMed1995

Nle4DPhe7 alpha-melanocyte-stimulating hormone increases the eumelanin:phaeomelanin ratio in cultured human melanocytes.

In mammals, melanin exists in two chemically distinct forms: the red-yellow phaeomelanin and the brown-black eumelanin. Although administration of the pigmentary hormone alpha-melanocyte-stimulating hormone (alpha MSH) and its synthetic analogue Nle4DPhe7 alpha MSH induces skin darkening in man, the increases in melanogenesis in cultured human melanocytes in response to these peptides are relatively small. However, it is possible that MSH affects the eumelanin:phaeomelanin ratio rather than total cellular melanin. Thus, this study examined the specific effects of Nle4DPhe7 alpha MSH on the two melanins in cultured human melanocytes, quantifying eumelanin and phaeomelanin by high performance liquid chromatography. Nle4DPhe7 alpha MSH induced significant increases in the eumelanin content of these cells while having lesser and varied effects on the levels of phaeomelanin. As a consequence, the eumelanin:phaoemelanin ratio was increased in every culture. These results demonstrate that Nle4DPhe7 alpha MSH affects melanin type in human melanocytes and suggest a possible mechanism by which this peptide induces skin darkening in man.

Adolescent↗
PubMed1995

The expression of tyrosinase, tyrosinase-related proteins 1 and 2 (TRP1 and TRP2), the silver protein, and a melanogenic inhibitor in human melanoma cells of differing melanogenic activities.

The expression of various melanogenic proteins, including tyrosinase, the tyrosinase-related proteins 1 (TRP1) and 2 (TRP2/DOPAchrome tautomerase), and the silver protein in human melanocytes was studied in six different human melanoma cell lines and compared to a mouse derived melanoma cell line. Analysis of the expression of tyrosinase, TRP1, TRP2, and the silver protein using flow cytometry revealed that in general there was a positive correlation between melanin formation and the expression of those melanogenic enzymes. Although several of the melanoma cell lines possessed significant activities of TRP2, the levels of DOPAchrome tautomerase in extracts of human cells were relatively low compared to those in murine melanocytes. Melanins derived from melanotic murine JB/MS cells, from melanotic human Ihara cells and HM-IY cells, from sepia melanin, and from C57BL/6 mouse hair were chemically analyzed. JB/MS cells, as well as Ihara cells and HM-TY cells, possessed significant amounts of 5,6-dihydroxyindole-2-carboxylic acid (DHICA) derived melanins, this being dependent on the activity of TRP2. Kinetic HPLC assays showed that 5,6-dihydroxyindole (DHI) produced during melanogenesis was metabolized quickly to melanin in pigmented KHm-1/4 cells, whereas DHI was stable in amelanotic human SK-MEL-24 cells. A melanogenic inhibitor that has been purified from SK-MEL-24 cells that suppressed oxidation of DHI in the presence or absence of tyrosinase, but had no effect on DHICA oxidation. The sum of these results suggests that the expression of melanogenic enzymes as well as the activity of a melanogenic inhibitor are critical to the production of melanin synthesis in humans.

Animals↗
PubMed1995

Seasonal variation in serum concentration of 5-S-cysteinyldopa and 6-hydroxy-5-methoxyindole-2-carboxylic acid in healthy Japanese.

Serum concentrations of 5-S-cysteinyldopa (5-S-CD) and 6-hydroxy-5-methoxyindole-2-carboxylic acid (6H5MI2C) have been used as biochemical markers of melanoma progression. We examined the effect of solar radiation on serum levels of 5-S-CD and 6H5MI2C in 10 healthy Japanese by measuring these markers every month during a period of 2 years. 5-S-CD levels were higher in early summer and lower in early winter. The difference in the average levels was approximately twofold, but among the 240 samples, no individual values exceeded the upper limit of normal value, 10 nmol/L. A significant correlation (P < 0.02) was observed between 5-S-CD level and solar radiation. 6H5MI2C levels showed a smaller variation than 5-S-CD. No correlation was observed between 6H5MI2C level and solar radiation. This study showed that serum 5-S-CD and 6H5MI2C in healthy Japanese did not exceed the upper limit of normal values even in sunny season.

Cysteinyldopa↗
PubMed1995

Influences of sex, castration, and androgens on the eumelanin and pheomelanin contents of different feathers in wild mallards.

In mallards the bright nuptial plumage of the drake represents the neutral, sex hormone-independent coloration of the species that both sexes eventually exhibit after castration. We compared the pheo- and eumelanin contents of feathers from the head, breast, flank, and under-tail coverts in five groups of mallards after the post-nuptial molt in summer: intact hens, intact drakes, castrated drakes, castrated drakes injected with testosterone during the spring, and castrated drakes injected with 5 alpha-dihydrotestosterone during the spring. In the head feathers and under-tail coverts, the gonadal hormones of the intact birds and the testosterone injections into castrates significantly reduced the eumelanin content, tended to increase the pheomelanin content, and, thereby, changed the melanin type from eumelanic in the untreated castrates to mixed melanic in the other three groups. The eumelanin contents of the flank feathers did not differ among the groups, but the pheomelanin contents at this site was significantly elevated in the two intact groups and the testosterone-treated compared to the uninjected castrates. Again, the melanin type changed from eumelanic in the castrates to mixed melanic in the other three groups. The high pheomelanin content of the breast feathers in the castrated birds was significantly reduced in the hens, intact drakes, and testosterone-injected castrates with a concomitant tendency for elevated eumelanin contents. At this site, a change occurred from pheomelanic to mixed melanic. 5 alpha-dihydrotestosterone was clearly less effective than testosterone in affecting the melanin contents in castrates and resulted in an intermediate coloration.(ABSTRACT TRUNCATED AT 250 WORDS)

Androgens↗
PubMed1995

Eumelanin and phaeomelanin contents of human epidermis and cultured melanocytes.

There are two chemically distinct types of melanin: the red-yellow phaeomelanins and the brown-black eumelanins. While both melanins have been detected in human epidermis and cultured melanocytes, it is unknown how the phaeomelanin/eumelanin ratio in human melanocytes maintained in vitro relates to that in the epidermis from which they were isolated. This study uses high-performance liquid chromatography to quantify the eumelanin and phaeomelanin contents of epidermis and/or cultured melanocytes from 12 Europeans with lightly pigmented skin and 9 non-Europeans with more deeply pigmented skin. Epidermis from non-Europeans contained the highest levels of both eumelanin and phaeomelanin and had the lowest phaeomelanin/eumelanin ratios. In contrast, while cultured melanocytes from non-Europeans also had higher levels of eumelanin and phaeomelanin than melanocytes from Europeans, there was no difference in the phaeomelanin/eumelanin ratios in the two groups. However, the phaeomelanin/eumelanin ratios were higher in the cultured melanocytes than in the corresponding epidermis so that while eumelanin was the predominant melanin in these epidermis, phaeomelanin was the major melanin in the cultured melanocytes. These observations may have important implications for the use of cultured human melanocytes in the study of melanogenesis in man.

Adult↗
PubMed1995

Chronic bronchobronchiolitis obliterans associated with Stevens-Johnson syndrome.

We report a case of bronchobronchiolitis obliterans associated with Stevens-Johnson syndrome diagnosed using bronchography and bronchoscopy in a 25-year-old man with dyspnea. Eighteen months prior to admission, the diagnosis of Stevens-Johnson syndrome due to anticonvulsant therapy was made at another hospital. On admission, the patient was wheezing and had overinflation of the lungs, with marked obstructive pulmonary dysfunction. Ventilation and perfusion scintigrams revealed multiple ventilation and perfusion defects but not mismatch. Bronchography revealed central bronchiectasis and obstruction of the peripheral bronchi. Occlusion of the fifth right basal bronchus was observed with fiberoptic bronchoscopy. Bronchography and bronchoscopy provide useful information for the diagnosis of this disease.

Adult↗
PubMed1994

Vesicle-bound conformation of melittin: transferred nuclear Overhauser enhancement analysis in the presence of perdeuterated phosphatidylcholine vesicles.

We determined a detailed conformation of the honeybee venom peptide melittin when bound to phosphatidylcholine vesicles using proton NMR. In the presence of vesicles of perdeuterated dipalmitoylglycerophosphocholine, two-dimensional transferred nuclear Overhauser enhancement (TRNOE) experiments were carried out. By a distance geometry calculation using NOE-derived distance constraints followed by a simulated annealing refinement, the N-terminal (Leu6-Leu10) and C-terminal (Leu13-Lys21) parts were found to have an alpha-helical conformation, whereas five C-terminal residues (Arg22-Gln26) did not show a unique conformation in the vesicle-bound state. The two alpha-helices were connected via a less structured segment (Thr11-Gly12) with a helix bend angle of 86 degrees +/- 34 degrees. Model distance geometry calculations using distance constraints extracted from a tetrameric melittin molecule in crystal assured us that the NOE constraints can accurately reproduce melittin's structure, as well as helping to interpret the NMR structures. Although the vesicle-bound conformation of melittin is similar to that occurring in a methanol solution and in dodecylphosphocholine micelles, significant differences were found in the conformation of C-terminal basic residues and the helix bend angle. This is the first study to clearly demonstrate conformation differences in micelle- and vesicle-bound peptides. In addition, lytic activity of melittin and its analogs showed better correlation with a peptide conformation in vesicles than in either methanol or micelles.

Amino Acid Sequence↗
PubMed1994

Evaluation of melanin-related metabolites as markers of melanoma progression.

BACKGROUND: Urinary excretion of 5-S-cysteinyldopa (5-S-CD) has been used as a biochemical marker of melanoma progression. Melanomas produce not only 5-S-CD but also 5,6-dihydroxyindole-2-carboxylic acid (5,6DHI2C) as major intermediates in melanin formation. 5,6DHI2C is then metabolized to the two O-methyl derivatives, 5H6MI2C and 6H5MI2C. The aim of this study was to determine which marker in serum and urine most sensitively reflected the progression of melanoma. METHODS: Serum and 24-hour urine samples were collected and assayed serially by high-performance liquid chromatography every 1 to 4 months in 28 patients with primary or recurrent melanomas, for up to 48 months. RESULTS: Serum concentration and urinary excretion of 5-S-CD and 6H5MI2C in patients with melanoma without metastases were close to those obtained from normal subjects. Metastases developed in 9 of the 28 patients. In seven of these nine patients, serum or urinary 5-S-CD values were elevated before or at the time of clinical detection of visceral metastases. However, serum 5-S-CD was elevated significantly earlier and reflected melanoma progression better than the physical examination and/or laboratory tests, such as scintigraphy and echography. Serum 6H5MI2C values exceeded the normal range shortly before death in three patients, and urinary 6H5MI2C did not increase at any stage in most patients, therefore these metabolites did not reflect progression of disease. CONCLUSIONS: Among the four markers, serum 5-S-CD appears to be the best biochemical marker for the detection of progression of melanotic melanoma, a value of more than 10 nmol/l suggesting the presence of metastasis.

Adult↗
PubMed1994

Influence of Korean pine (Pinus koraiensis)-seed oil containing cis-5,cis-9,cis-12-octadecatrienoic acid on polyunsaturated fatty acid metabolism, eicosanoid production and blood pressure of rats.

The effects of dietary Korean pine (Pinus koraiensis)-seed oil containing a peculiar trienoic acid (cis-5,cis-9,cis-12-18:3, pinolenic acid, approximately 18%) on various lipid variables were compared in rats with those of flaxseed (Linum usitatissimum L.) oil, safflower (Carthamus tinctorius L.) oil and evening primrose (Oenothera biennis L.) oil under experimental conditions where the effects of different polyunsaturated fatty acids could be estimated. In Sprague-Dawley rats fed on diets containing 100 g fat and 5 g cholesterol/kg, the hypocholesterolaemic activity of pinolenic acid was intermediate between alpha-linolenic and linoleic acids. Analysis of the fatty acid composition of liver phosphatidylcholine indicated that, in contrast to alpha-linolenic acid, pinolenic acid does not interfere with the desaturation of linoleic acid to arachidonic acid. However, the effects on ADP-induced platelet aggregation and aortic prostacyclin production were comparable. When spontaneously hypertensive rats were fed on diets containing 100 g fat/kg but free of cholesterol, gamma-linolenic and pinolenic acids, as compared with linoleic acid, increased prostacyclin production and tended to reduce platelet aggregation. In addition, pinolenic acid attenuated the elevation of blood pressure after 5 weeks of feeding. Thus, the results of the present studies indicate the beneficial effects of pinolenic acid on various lipid variables.

Animals↗
PubMed1994

alpha-Linolenic, eicosapentaenoic and docosahexaenoic acids affect lipid metabolism differently in rats.

Rats were fed purified diets containing 10% fat with constant (n-6):(n-3) polyunsaturated fatty acids [(n-6):(n-3); 2.3-2.6] and polyunsaturated:saturated fatty acids (1) ratios. This was obtained with alpha-linolenic acid, eicosapentaenoic acid and docosahexaenoic acid added at 1 g/100 g diet. Eicosapentaenoic acid and docosahexaenoic acid were added as the ethyl esters. The concentration of plasma cholesterol in rats fed docosahexaenoic acid was significantly lower than in those fed alpha-linolenic acid. The concentration of plasma triglyceride was significantly lower in rats fed eicosapentaenoic acid than in those fed docosahexaenoic acid. Docosahexaenoic acid significantly reduced hepatic cholesterol compared with alpha-linolenic acid and eicosapentaenoic acid. Both eicosapentaenoic acid and docosahexaenoic acid decreased hepatic triglyceride compared with alpha-linolenic acid, but this effect was more pronounced in the docosahexaenoic acid group. There was no significant difference in fecal excretion of neutral and acidic steroids and apparent fat absorption. In rats fed docosahexaenoic acid, the proportion of arachidonic acid in liver microsomal phosphatidylcholine was lower than in those fed eicosapentaenoic acid. The same tendency was observed in plasma, platelet and aortic phosphatidylcholine and liver microsomal phosphatidylethanolamine and phosphatidylinositol. Dietary docosahexaenoic acid, but not eicosapentaenoic acid, significantly decreased aortic production of prostacyclin compared to alpha-linolenic acid, whereas platelet aggregation by collagen was not affected by the difference in dietary (n-3) polyunsaturated fatty acids.

Animals↗
PubMed1994

Circular dichroism studies of the interaction between synthetic peptides corresponding to intracellular loops of beta-adrenergic receptors and phospholipid vesicles.

We previously showed that peptides corresponding to the N-terminal parts of the third intracellular loops of turkey and hamster beta-adrenergic receptors (tu beta I3N and ha beta I3N, respectively) can activate the GS protein (one of the GTP-binding regulatory proteins which couples to the beta-adrenergic receptor) reconstituted in phospholipid vesicles, and also that such activation can be greatly enhanced by a modification which increases the hydrophobicity of the peptides. These observed phenomena suggest that the interaction with phospholipid membranes is important for the activity of these peptides; hence, in the present study we employed circular dichroism to analyze the interaction of the synthetic peptides corresponding to the intracellular loops of G protein-coupled receptors with phosphatidylserine/phosphatidylcholine mixed vesicles. The tu beta I3N and ha beta I3N peptides were subsequently found to take on an alpha-helical conformation upon binding with the vesicles, whereas those corresponding to the intracellular loops of m1 and m2 muscarinic acetylcholine receptors in contrast did not interact with the vesicles. The positions of several side chains of the membrane-bound loop peptides were also determined. Our results show for the first time the interaction occurring between the intracellular loops of beta-adrenergic receptors and a phospholipid membrane.

Amino Acid Sequence↗
PubMed1994

Selective decrease of eumelanin in hypopigmented epidermis of hypomelanosis of Ito.

A Japanese infant had bilateral hypopigmented macules in a whorled or marble-cakelike configuration on her trunk and extremities. Her irides were bluish gray and her hair was dark brown. She had photophobia and macrocephaly with developmental delay. Analysis of peripheral lymphocytes and dermal fibroblasts disclosed a normal chromosomal pattern. A new finding was that the eumelanin content of the hypopigmented epidermis was decreased. We suggest that at least a portion of patients with this disorder have a defect in eumelanogenesis in hypopigmented skin.

Epidermis↗
PubMed1994

An improved modification of permanganate oxidation of eumelanin that gives a constant yield of pyrrole-2,3,5-tricarboxylic acid.

Microanalysis of eumelanin is based on the formation of pyrrole-2,3,5-tricarboxylic acid (PTCA) on permanganate oxidation followed by its HPLC determination. A problem in this method was that the oxidation gave concave, exponential curves when the amounts of PTCA formed were plotted against the amounts of sample oxidized. The problem has been mostly overcome by adding a homogenate of 5 mg of a mouse liver to the oxidation medium. Sepia melanin, C57BL black mouse hair, B16 mouse melanoma, and MM418 human melanoma cells were oxidized in the absence or presence of the liver homogenate. The yields of PTCA increased about 1.5-fold by adding the liver homogenate and the calibration curves became linear or almost linear. With the improved method the PTCA values from various types of samples can be reliably compared.

Animals↗