Efficacy of sucroferric oxyhydroxide treatment in Japanese hemodialysis patients and its effect on gastrointestinal symptoms.

Sucroferric oxyhydroxide (SFOH) is a non-calcium, iron-based phosphate binder indicated for the treatment of hyperphosphatemia in adult dialysis patients. Studies in Japan about the side effects of SFOH treatment indicate that the incidence of diarrhea (25%) is greater while that of constipation (2.9%) is lesser in comparison to that observed upon treatment with an existing phosphate binder. In the present study, the effect of treatment with a combination of the existing phosphate binders and SFOH on the serum phosphorus level and digestive symptoms was observed in hemodialysis patients with hyperphosphatemia, which is untreatable using only the existing phosphate binders. We evaluated the serum phosphorus levels and gastrointestinal symptoms (using the gastrointestinal symptom rating scale) of 6 patients (2 men, 4 women) before and 2, 4, 6, and 8 weeks after continuous administration. The serum phosphorus levels before and 2, 4, 6, and 8 weeks after combination treatment were 7.4±1.0 mg/dL, 5.9±1.3 mg/dL, 5.8±1.5 mg/dL, 5.8±1.4 mg/dL, and 5.8±1.3 mg/dL, respectively, with significant reduction in the levels being observed 2 weeks after administration (p<0.05) and persisting even 8 weeks after continuous administration. The constipation scores before and 2, 4, and 8 weeks after drug administration were 2.39±0.85, 2.34±1.93, 2.56±1.44, and 3.28±2.19, respectively, with no changes observed during the investigation period. The diarrhea scores before and 2, 4, and 8 weeks after drug administration were 2.22±0.91, 2.06±1.16, 1.28±0.39, and 1.06±0.13 respectively. The scores improved significantly, 4 weeks after drug administration (p<0.05), and the improvement persisted, even 8 weeks after continuous administration. Thus, by using a combination of the existing phosphate binders and SFOH, we were able to reduce the serum phosphorus level in patients with hyperphosphatemia, which is untreatable using the existing phosphate binder alone, with no sign of exacerbation of the gastrointestinal symptoms despite a few contradictory case reports.

Cancer emerging from the recurrence of sessile serrated adenoma/polyp resected endoscopically 5 years ago.

Since the serrated neoplastic pathway has been regarded as an important pathway of colorectal carcinogenesis, few reports have been published on clinical cases of cancer derived from sessile serrated adenoma/polyp, especially on recurrence after resected sessile serrated adenoma/polyp. An elderly woman underwent endoscopic mucosal resection of a flat elevated lesion, 30 mm in diameter, in the ascending colon; the histopathological diagnosis at that time was a hyperplastic polyp, now known as sessile serrated adenoma/polyp. Five years later, cancer due to the malignant transformation of the sessile serrated adenoma/polyp was detected at the same site. The endoscopic diagnosis was a deep invasive carcinoma with a remnant sessile serrated adenoma/polyp component. The carcinoma was surgically removed, and the pathological diagnosis was an adenocarcinoma with sessile serrated adenoma/polyp, which invaded the muscularis propria. The surgically removed lesion did not have a B-RAF mutation in either the sessile serrated adenoma/polyp or the carcinoma; moreover, the initial endoscopically resected lesion also did not have a B-RAF mutation. Immunohistochemistry confirmed negative MLH1 protein expression in only the cancer cells. Lynch syndrome was not detected on genomic examination. The lesion was considered to be a cancer derived from sessile serrated adenoma/polyp recurrence after endoscopic resection, because both the surgically and endoscopically resected lesions were detected at the same location and had similar pathological characteristics, with a serrated structure and low-grade atypia. Furthermore, both lesions had a rare diagnosis of a sessile serrated adenoma/polyp without B-RAF mutation. This report highlights the need for the follow-up colonoscopy after endoscopic resection and rethinking our resection procedures to improve treatment.

Evaluation of the potassium adsorption capacity of a potassium adsorption filter during rapid blood transfusion.

The concentration of extracellular potassium in red blood cell concentrates (RCCs) increases during storage, leading to risk of hyperkalemia. A potassium adsorption filter (PAF) can eliminate the potassium at normal blood transfusion. This study aimed to investigate the potassium adsorption capacity of a PAF during rapid blood transfusion. We tested several different potassium concentrations under a rapid transfusion condition using a pressure bag. The adsorption rates of the 70-mEq/l model were 76·8%. The PAF showed good potassium adsorption capacity, suggesting that this filter may provide a convenient method to prevent hyperkalemia during rapid blood transfusion.

The association between risk factors and time of onset for thrombocytopenia in Japanese patients receiving linezolid therapy: a retrospective analysis.

WHAT IS KNOWN AND OBJECTIVE: Linezolid (LZD) is an oxazolidinone antibiotic that is active against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci. The major adverse effect related to its use in humans is reversible myelosuppression, which mostly manifests as thrombocytopenia. This retrospective study was conducted to identify risk factors that might contribute towards the development of thrombocytopenia due to intravenous administration of LZD. METHOD: Patients who were administered LZD between January 2008 and March 2013 were included. Thrombocytopenia was defined as a decrease in platelet count of ≥10 × 10(4) cell/µL from baseline or of ≥30%. RESULTS: A total of 47 patients were included in this study. These patients were divided into two groups: 22 patients (46·8%) were assigned to a non-thrombocytopenia group and 25 patients (53·2%) to a thrombocytopenia group. Multivariate logistic regression analysis revealed significant intergroup differences in duration of LZD treatment [odds ratio (OR) = 1·278; 95% confidence interval (CI) = 1·068-1·529; P = 0·007] and white blood cell (WBC) count (>12000 cells/µL; OR = 10·399; 95% CI = 1·667-64·882; P = 0·012). WHAT IS NEW AND CONCLUSIONS: This finding suggests that duration of LZD treatment and WBC count (>12000 cells/µL) are risk factors associated with thrombocytopenia resulting from LZD administration.

Gastrointestinal symptoms after the substitution of sevelamer hydrochloride with lanthanum carbonate in Japanese patients undergoing hemodialysis.

Lanthanum carbonate has the same phosphorus depressant effect as the other phosphorus adsorbents, and is expected to decrease digestive symptom onset such as constipation in Japanese patients undergoing hemodialysis compared to sevelamar hydrochloride. In this study, we investigated the short- and long-term changes in digestive symptoms in these patients after substituting sevelamar hydrochloride with lanthanum carbonate. We studied 16 patients (4 men, 12 women) and evaluated their gastrointestinal symptoms before administration, at the time of administration, and 2, 4, 8, and 12 weeks after administration, using the Gastrointestinal Symptom Rating Scale. In addition, we conducted repeat evaluations 52 weeks after administration for the patients in whom lanthanum carbonate was administered continuously for 52 weeks. Fourteen (87.5%) out of the 16 patients could tolerate continuous administration for 12 weeks. The constipation score was 3.21 ± 1.74 before administration, 2.07 ± 0.83 2 weeks after administration, 1.76 ± 0.83 4 weeks after administration, 1.57 ± 0.56 8 weeks after administration, and 11.41 ± 0.48 12 weeks after administration. The scores improved significantly 4 weeks after administration (p < 0.05) and even 12 weeks after continuous administration. Among the 16 study patients, 9 patients (1 men, 8 women) were received lanthanum carbonate continuously for 52 weeks. The constipation score was 3.74 ± 1.92 at the start of administration, 1.37 ± 0.56 12 weeks after administration, and 1.85 ± 0.63 52 weeks after administration, with significant improvement even 52 weeks after administration (p < 0.05). This study shows that substituting sevelamar hydrochloride with lanthanum carbonate improves constipation symptoms in hemodialysis patients from an early stage, which indicates its usefulness in improving constipation symptoms caused by sevelamar hydrochloride.

Influence of cerebral fluid drainage on the pharmacokinetics of vancomycin in neurosurgical patients.

The objective of this study was to retrospectively investigate the influence of cerebral fluid drainage on the serum concentrations and pharmacokinetic parameters of vancomycin (VCM). We analyzed 55 patients with normal renal function who had been hospitalized in the neurosurgical ward and received intravenous infusions of VCM. We compared the daily doses of VCM, serum VCM concentrations, serum concentration/dose ratio (C/D ratio), and pharmacokinetic parameters calculated using the Sawchuk-Zaske method between patients who underwent cerebral fluid drainage (drainage group) and controls (non-drainage group). The patients in the drainage group showed a significantly lower trough concentration of VCM (5.8 ± 3.3 µg/mL) than that shown by the non-drainage group (9.9 ± 5.4 µg/mL, p = 0.017). Further, the patients in the drainage group showed a significantly lower trough C/D ratio (0.32 ± 0.17) than that shown by the non-drainage group (0.50 ± 0.31, p = 0.047). In conclusion, cerebral fluid drainage may influence VCM pharmacokinetics. Our findings strongly suggest that a high dose of VCM is required to maintain optimal serum concentrations of VCM in patients managed with cerebral fluid drainage.

Immunosuppressive effect of prolactin-induced protein: a new insight into its local and systemic role in chronic allergic contact dermatitis.

BACKGROUND: Prolactin-induced protein (PIP) has been shown to bind to CD4 and is speculated to block CD4-HLA-DR interaction. However, the immunomodulatory effect of PIP on chronic allergic contact dermatitis (ACD) remains to be elucidated. OBJECTIVES: To define the role of PIP during the immunoresponse. METHODS: Using a low-dose oxazolone-induced mouse chronic ACD model, expression of PIP was examined immunohistologically. Furthermore, effects of continued exposure to a peptide mimicking the major binding site of PIP (amino acids 106-132) for CD4 was examined in a mouse chronic ACD model. RESULTS: We clarified that keratinocytes, dermal infiltrating cells and spleen infiltrating mononuclear cells are positively stained with anti-PIP antibody. The PIP peptide significantly downregulated oxazolone-induced mouse ACD compared with controls. We also found that inflammation of the control ear, to which the PIP peptide had not been applied, was also suppressed in a synchronized manner in the late phase of ACD. CONCLUSIONS: These findings suggest that PIP might have a local and systemic immunosuppressive effect in mouse chronic ACD.

Central projections of identified, unmyelinated (C) afferent fibers innervating mammalian skin.

Unmyelinated (C) fibers are the most numerous sensory elements of mammalian peripheral nerve and comprise many of those responsible for initiating pain and temperature reactions; however, direct evidence has been lacking as to where and how these fibers terminate in the central nervous system. A plant lectin (Phaseolus vulgaris leukoagglutinin) was applied intracellularly by iontophoresis as an immunocytochemical marker. This permitted visualization of the central terminations of cutaneous C sensory fibers that had been identified by the nature of stimuli that excited them. The central branch of C-fiber units arborized and terminated mainly in the superficial layers of the spinal dorsal horn in defined patterns that related to their functional attributes. Thus, the superficial dorsal horn seems to act as a processing station for signals from fine sensory fibers.

[Tonsillar metastais from primary lung large cell neuroendocrine carcinoma in the early stage; report of a case].

We experienced an extremely rare case of large cell neuroendocrine carcinoma (LCNEC) of the lung metastasizing to the tonsil. A 66-year-old woman who had been undergone radical hysterectomy and radiated on whole pelvis in June, 2006, was pointed out 2 cm diameter abnormal shadow at the right S8 of the lung by computed tomography (CT) in May, 2007. In June, 2007, the right lower lobectomy with lymphandenectomy was done by video-assisted thoracic surgery (VATS). The pathological diagnosis was stage IA LCNEC of the lung. In April, 2008, multiple metastases to the brain appeared, and the patient unederwent gamma knife treatment. In addition, metastases to the liver, lymphnode of abdomen, left adrenal and bone followed in 1 month. Although we considered a chemotherapy, her general condition deteriorated rapidly with development of right tonsil metastasis and died as lasly as 3 months later.

A case of bilateral parietal cortical laminar necrosis with a loss of vertiginous sensation.

BACKGROUND: Animal experiments demonstrated that there are vestibular cortical areas at the parietal cortex. Moreover, in humans, recent functional neuroimaging studies revealed that caloric stimulation activated the parietoinsular vestibular cortex and optokinetic stimulation activated the parieto-occipital cortex. These activations indicate that the parietal vestibular areas play some role in nystagmus generation or in spatial information processing in the eye movement tasks. AIMS OF THE STUDY: The aim of this communication was to present a patient giving some information about parietal cortical function in nystagmus production and vertigo. CASE: We report a 51-year-old, heavy alcoholic man with Bálint syndrome, constructional disability, limb-kinetic apraxia and ideo-motor apraxia. Brain magnetic resonance imaging demonstrated bilateral parietal cortical laminar necrosis anterior to the parieto-occipital sulci without any involvement of the primary sensory and parietoinsular cortices. Optokinetic nystagmus (OKN) was not elicited whereas cold caloric stimulation fully evoked nystagmus toward the opposite side with oscillopsia when eyes opened. However, he did not feel vertiginous sensation when the eyes were closed. CONCLUSIONS: These findings suggest that the parietal cortices are indispensable for OKN production and vertiginous sensation.

Mandibular reconstruction with free fibula flaps in the elderly: a retrospective evaluation.

The purpose of this study was to evaluate surgical outcomes in elderly patients who had undergone free fibula flap transfer for malignant head and neck tumours. A retrospective chart review was performed to identify patients who had undergone free fibula flap transfer for mandibular reconstruction after malignant tumour resection at Jichi Medical University Hospital between May 2009 and April 2015. Enrolled patients were divided into an elderly group (≥80years old) and a younger group (<80years old). Seventeen patients met the inclusion criteria and were included in the elderly group. Age at surgery ranged from 80 to 92years. Thirteen patients (76.5%) experienced postoperative complications. Surgical site complications occurred in seven patients. The success rate of free fibula flap transfer was 100%. Systemic complications occurred in nine patients, most commonly delirium (n=6). No perioperative mortality was encountered. The overall 1-year survival rate was 94.1% (16/17). No patient reported gait disturbance as a donor site complication or any other major complication. The incidence of postoperative complications did not differ significantly between the elderly and younger groups. Almost no difference in postoperative course was seen between the groups. Elderly patients appear to tolerate free fibula flap reconstruction just as well as younger patients.

Ribosomal P protein P0 as a candidate for the target antigen of anti-endothelial cell antibodies in mixed connective tissue disease.

OBJECTIVE: To evaluate the presence of anti-endothelial cell antibodies (AECA) in patients with mixed connective tissue disease (MCTD) compared to those with systemic sclerosis (SSc) and to determine the candidates for the endothelial auto-antigen that reacts with AECA in patients with MCTD using a molecular cloning strategy. METHODS: AECA were measured by a cellular enzyme-linked immunosorbent assay (ELISA) using fixed human umbilical vein endothelial cells (HUVEC) in 47 MCTD patients, 68 SSc patients, and 52 normal controls. A HUVEC cDNA expression library was immunoscreened with pooled sera from 6 patients with high AECA levels determined by cellular ELISA to explore the endothelial autoantigens in MCTD. An ELISA assay for anti-ribosomal protein P0 antibodies was used to assess the correlation with AECA levels. RESULTS: The candidate target proteins recognized by AECA in MCTD included: (i) ribosomal protein P0; (ii) a putative oncogene derived from dek mRNA; (iii) SS-B/La protein; (iv) U1 RNA-associated 70K protein; and (v) DNA-binding protein B. A significant correlation between the levels of AECA and anti-ribosomal protein P0 antibodies was demon-strated in MCTD, but not in systemic sclerosis. The sera containing high levels of AECA from patients with MCTD frequently cross-reacted with ribosomal protein P0. On the other hand, sera without AECA activity from patients with MCTD never reacted with ribosomal protein P0. CONCLUSION: AECA were more frequently seen in patients with MCTD than in patients with SSc. Ribosomal protein P0 may be one of the major target antigens of AECA in patients with MCTD.

Fibre-free diet leads to impairment of neuronally mediated muscle contractile response in rat distal colon.

Dietary fibre consumption is known to be beneficial to increase stool bulk and frequency. In contrast, it is unclear whether chronic dietary fibre deficiency affects colonic motor functions, especially neuronally mediated muscle contractions. In this study, rats were fed a fibre-free diet or diet containing dietary fibre (cellulose or guar gum) for 27 days. Furthermore, neurogenic and myogenic contractions were evaluated in circular and longitudinal muscle strips of the distal colon. Additionally, the number of enterochromaffin (EC) cells, which play important roles in the initiation of the peristaltic reflex, was also examined by immunohistochemistry for serotonin. Myogenic contractions induced by carbachol or substance P were examined in the presence of tetrodotoxin. Circular muscle was hyposensitive to carbachol, but longitudinal muscle was hypersensitive to substance P in the fibre-free group. Nerve-mediated circular (5-20 Hz) and longitudinal (1-2 Hz) muscle contractions evoked by electrical field stimulation were attenuated in the fibre-free group and the latter response was almost abolished by atropine, suggesting functional changes of cholinergic neurons. EC cell number was decreased in the fibre-free group. In conclusion, changes in neurogenic and myogenic contractions and a decrease in EC cell number observed may affect colonic motility of the fibre-free group.

Selected base sequence outside the target binding site of zinc finger protein Sp1.

Human transcription factor Sp1 contains three contiguous repeats of the C2H2-type zinc finger motif and binds to the decanucleotide sequence 5'-(G/T)GGGCGG(G/A)(G/A)(C/T)-3' (GC box). In order to determine whether the three-zinc finger peptide Sp1(530-623) has selectivity for sequence outside the GC box, we used a selection and amplification of binding experiment. The high affinity sequence generated from this selection is 5'-GGGTGGGCGTGGC-3' (s-GC box), which is flanked by a novel conserved guanine triplet on the 5'-side of the core decanucleotide. Gel mobility shift assays reveal that Sp1(530-623) binds to the s-GC box with 2.3-fold higher affinity than to the wild-type GC box, 5'-GGGGCGGGGC-3' (c-GC box). DNase I and hydroxyl radical footprinting analyses show that the area of the s-GC box protected by binding of Sp1(530-623) is wider by 1 nt than that of the c-GC box. On the other hand, alkylation interference analyses demonstrate that Sp1(530-623) forms only one special base contact at the guanine triplet. With respect to cleavage of the c-GC and s-GC boxes by the 1,10-phenanthroline-copper complex (OP-Cu), binding of Sp1(530-623) has no effect on the cleavage pattern of the s-GC box, whereas OP-Cu actually enhances cleavage of the c-GC box. Additionally, the extent of cleavage of the s-GC box by DNase I and OP-Cu is clearly different from that of the c-GC box under peptide-free conditions. The results strongly indicate that: (i) the conformation of the s-GC box is evidently distinct from that of the c-GC box; (ii) Sp1(530-623) binds to the s-GC box without induction of a conformational change in DNA detectable by cleavage with OP-Cu. The present study provides useful information for the design of multi-zinc finger proteins with various sequence specificities.

The plasminogen-plasminogen activator (PA) system in neuroblastoma: role of PA inhibitor-1 in metastasis.

Proteases of the plasminogen-plasminogen activator (PA) system play an important role in cancer metastasis. We have examined the expression of these proteases and their cell surface receptors and inhibitors in neuroblastoma, a tumor that originates in cells of the neural crest and is the second most common solid tumor in children. This analysis was performed in seven established human cell lines and 20 primary tumor specimens. Urokinase PA and, in particular, tissue-type PA were expressed in cell lines and in tumor tissues; however, their levels of expression did not correlate with clinical stage. There was little evidence suggesting that neuroblastoma cells concentrate PA activity at their cell surface because urokinase-type PA receptor mRNA was detected in two cell lines and in 5 of 20 tumor samples by reverse transcription-PCR only. PA inhibitor (PAI)-2 was absent in all cell lines and tumor tissue samples examined. However, PAI-1, which was not expressed by the cell lines, was expressed by stromal cells and, specifically, endothelial cells in tumor tissue. By extending the analysis of PAI-1 expression in 64 primary tumor specimens, we found that high PAI-1 expression paradoxically correlated with metastatic stage and tumor recurrence. In vitro experiments indicated that the expression of PAI-1 by human microvascular endothelial cells was stimulated in the presence of SK-N-BE(2) human neuroblastoma cells and neuroblastoma culture medium. Recombinant PAI-1 also promoted SK-N-BE(2) cell detachment from vitronectin and migration from vitronectin toward fibronectin. From these data, we conclude that the up-regulation of PAI-1 expression in endothelial cells may promote rather than inhibit metastasis in neuroblastoma.

Matrix metalloproteinases-2 and -9 are expressed in human neuroblastoma: contribution of stromal cells to their production and correlation with metastasis.

Neuroblastoma, the second most common solid childhood tumor, can be a highly invasive and metastatic form of cancer. To assess the role of matrix-degrading proteases in this cancer, we have examined the expression of matrix metalloproteinases (MMPs) and their corresponding tissue inhibitors of metalloproteinases (TIMPs) in 7 human neuroblastoma cell lines and 24 primary untreated tumors. MMP-2 (gelatinase A) and MMP-9 (gelatinase B) were the only two MMPs expressed. MMP-2 was detected predominantly in an inactive proform in all tumor cell lines and tumor tissue extracts. The lack of MMP-2 activation in cell lines was attributed to the absence of expression of a membrane-type MMP (MT1-MMP), which activates proMMP-2, and to the abundant expression of TIMPs, particularly TIMP-2. Immunohistochemical analysis of tumor tissue samples indicated that MMP-2 was present in both tumor cells and stromal cells. In contrast, MMP-9 was not expressed by neuroblastoma cell lines but was present in inactive and active forms in extracts from tumor tissues. Immunohistochemical analysis of positive specimens indicated that MMP-9 was predominantly present in stromal, vascular, and perivascular cells surrounding nests of tumor cells. There was no correlation between the levels of these MMPs and the MYCN copy number or the histopathological phenotype. However, there were higher levels of MMP-2 and MMP-9 in stage IV (metastatic) disease when compared with stages I and II (noninvasive and nonmetastatic) or IV-S (P < 0.05).

Structure of molecular aggregates of 1-(3-sn-phosphatidyl)-L-myo-inositol 3,4-bis(phosphate) in water.

The molecular organization of 1-(3-sn-phosphatidyl)-L-myo-inositol 3,4-bis-(phosphate)/water systems is investigated over a wide range of lipid concentrations using X-ray diffraction, calorimetry, analytical ultracentrifugation, densitometry and viscometry. At high lipid concentrations, the lipid molecules are found to form a lamellar phase. The repeat distance increases from 60 to 120 A with increasing water content to 70 wt% and the surface area per lipid molecule increases from 41.7 A2 to a limiting value of 100 A2. On the other hand, at very low lipid concentrations the molecules are found to form not vesicles but micelles, the total molecular weight of which takes a value of 93,000. This finding revises the prevalent view that lipids containing two (or more) hydrocarbon chains form extended bilayers or vesicles, whereas single chained lipids form micelles.

DNA binding mode of class-IIS restriction endonuclease FokI revealed by DNA footprinting analysis.

We investigate the interaction of FokI with its DNA recognition sequence by several footprinting techniques. Methylation of three guanine bases in the recognition sequence 5'-GGATG-3' is strongly protected by FokI binding, whereas other guanine bases are not masked from the modification. In footprinting using the methidiumpropyl-EDTA-Fe(II) complex, binding of FokI strongly inhibits cleavage by the footprinting reagent at and near the recognition sequence. In high-resolution footprinting techniques using hydroxyl radical and the bleomycin-Fe(II) complex, all footprints in each binding site clearly face one side of the DNA helix. Interference analysis with FokI digestion by preethylation of phosphate groups suggests that essential phosphates for FokI digestion are located at and near the recognition sequence and the cleavage site. Evidently, the results indicate that (i) the sequence-recognition of FokI occurs in the major groove and that (ii) the enzyme interacts with its target DNA from one side of the DNA helix.

Hydrophobic DNA binding of esperamicin requires conformational distortion of the host DNA.

Evidence is presented that the sequence-specific DNA binding of esperamicin is accompanied by structural distortion of the host DNA that depends on hydrophobic interactions. In the first part of this paper, we describe the effects of conformational freedom of DNA on the DNA-cutting efficiency of esperamicin. If conformational distortion of DNA is significantly required for binding of the drug, then the drug should possess a lower binding/cleaving efficiency for conformationally more restricted DNAs. Our results on model DNAs reveal a substantial decrease in the DNA-cleaving efficiency of esperamicin as the conformational freedom of DNA decrease. In the second part we demonstrate that esperamicin binds to DNA with considerably higher affinity in solutions containing organic solvents. This observation indicates that the required distortion of DNA depends on hydrophobic interactions. Molecular origins of the sequence-specific binding are also discussed on the basis of all available data.

DNA interaction and nucleotide sequence cleavage of copper-streptonigrin.

The copper-accelerated DNA binding and cleavage of streptonigrin have been investigated by 1H-NMR, ESR spectrometry and nucleotide sequence analysis. In the DNA breakage by the streptonigrin-Cu(II)-NADPH system, the somewhat preferred cleavage sites were several cytosine bases adjacent to purine bases such as GCGG(5'----3'), ACGC(5'----3') and GGCG(5'----3') sequences. The proton chemical shifts for the streptonigrin-Cu(I)-poly(dA-dT) complex demonstrated the interaction between the pyridine ring of the drug and the purine bases of the nucleic acid. Indeed, the temperature profile of adenine H-2 proton clearly showed the Tm to shift from 70 degrees C in the binary streptonigrin-poly(dA-dT) system to 75 degrees C in the ternary streptonigrin-Cu(I)-poly(dA-dT) system. The interaction of the streptonigrin-Cu(II) complex with DNA also induced the apparent change of ESR parameters. The tricyclic phenanthidium ring system including the copper chelate ring appears to significantly contribute to the present DNA interaction and cleavage of copper-streptonigrin.