Survey of medications for myelomeningocele patients over their lifetime in Japan

BACKGROUND

This study aimed to investigate medication prescriptions for patients with myelomeningocele (MMC) across different age groups, particularly in adulthood and after middle age.

METHODS

The Japan Medical Data Center (JMDC) database, based on medical claims data, was utilized for this analysis. Patients were divided into 10-year age groups, and prescriptions for analgesics, anticonvulsants, psychotropic drugs, lifestyle disease-related drugs, drugs for urinary incontinence, and laxatives were examined. To compare the differences in the utilization of medications unrelated to lifestyle-related diseases across different age groups, the data was categorized into three age groups: 19 or under, 20-39, and 40 or older.

RESULTS

Among the 556 MMC patients, the percentage of those regularly prescribed analgesics increased from 2.8% in patients ≤ 19 to 31.7% in patients 40 or older (p < 0.01). Psychotropic medication use also increased with age, rising significantly from 6.3% in patients ≤ 19 to 34.6% in patients 40 or older (p < 0.01). Patients with MMC showed an increasing trend in prescriptions for lifestyle-related disease medications compared to the normal control group. Notably, the percentage of patients in their 30 s taking hypertension medication was 4.9%, significantly higher than the 0.86% in the control group (p = 0.029). In their 40 s, 22.9% of MMC patients were prescribed hyperlipidemia medication, significantly higher than the 3.9% in the control group (p < 0.01).

CONCLUSION

Comprehensive multidisciplinary support and follow-up are crucial to enhance the quality of life for MMC patients, with particular attention to pain management, psychological care, and treatment of lifestyle-related diseases.

Refractory Delayed Pneumocephalus after Transsphenoidal Cyst Drainage for Rathke's Cleft Cyst in a Patient with a Cerebrospinal Fluid Shunt

A 75-year-old man presented with bilateral lower limb weakness to our hospital from another clinic. Radiological examinations implied the possibilities of idiopathic normal pressure hydrocephalus (iNPH) and a suprasellar cyst, but both were observed conservatively at that time. Due to the progressive gait disturbance, a lumboperitoneal shunt was implanted 1 year later. The clinical symptoms improved, but the cyst had grown after another year, causing visual impairment. Transsphenoidal drainage of the cyst was performed, but delayed pneumocephalus occurred. Repair surgery was performed with temporary suspension of shunt function, but pneumocephalus relapsed two and a half months after the resumption of shunt flow. In the second repair surgery, the shunt was removed because it was assumed that it would prevent closure of the fistula by lowering intracranial pressure. Two and a half months later, after confirming involution of the cyst and no pneumocephalus, a ventriculoperitoneal shunt was implanted, and cerebrospinal fluid (CSF) leakage has not relapsed since then. The coexistence of idiopathic normal pressure hydrocephalus (iNPH) and Rathke's cleft cyst (RCC) is rare, but it can occur. RCC can be cured by simple drainage, but delayed pneumocephalus can occur in cases whose intracranial pressure decreases due to CSF shunting. When simple drainage without sellar reconstruction for RCC is attempted after CSF shunting for coexistent iNPH, attention should be paid to changes in intracranial pressure, and it is desirable to stop the flow of the shunt for a certain period.

Comparison of intraoperative neurophysiological monitoring methods for lumbosacral lipoma surgery in infants

BACKGROUND

Stable intraoperative neurophysiology monitoring of infants, especially very young infants, is challenging. In this study, motor evoked potentials (MEPs), the bulbocavernosus reflex (BCR), and somatosensory evoked potentials (SEPs) were simultaneously monitored in infants with lumbosacral lipomas, and these methods were compared retrospectively.

METHODS

A total of 21 surgeries performed for lumbosacral lipoma in patients less than 1 year old were studied. The mean age at surgery was 133.8 days (range 21-287 days; ≤ 120 days: 9 cases, > 120 days: 12 cases). Transcranial MEPs were measured in the anal sphincter and gastrocnemius, and tibialis anterior and other muscles were added as needed. The BCR was measured by the electromyogram of the anal sphincter muscle with stimulation of the pubic region, and SEPs were measured from the waveforms of stimulation of the posterior tibial nerves.

RESULTS

For the BCR, stable potentials could be recorded for all 9 cases at ≤ 120 days of age. In contrast, for MEPs, stable potentials could be recorded in only 4 of 9 cases (p < 0.05). For all patients > 120 days of age, MEPs and the BCR were measurable. SEPs were undetectable in some patients regardless of age.

CONCLUSION

The BCR could be more consistently measured than MEPs in infant patients with lumbosacral lipoma at ≤ 120 days of age.

A case of acute hydrocephalus due to a giant prolactinoma rescued by transventricular neuroendoscopic tumorectomy

Background

A giant prolactinoma extending to the suprasellar area and causing hydrocephalus may be life-threatening and should be treated promptly. A case of a giant prolactinoma with acute hydrocephalus that underwent transventricular neuroendoscopic tumor resection followed by cabergoline administration is presented.

Case Description

A 21-year-old man had a headache lasting for about a month. He gradually developed nausea and disturbance of consciousness. Magnetic resonance imaging showed a contrast-enhanced lesion that extended from the intrasellar space to the suprasellar space and into the third ventricle. The tumor obstructed the foramen of Monro and caused hydrocephalus. A blood test showed marked elevation of prolactin (16,790 ng/mL). The tumor was diagnosed as a prolactinoma. The tumor in the third ventricle had formed a cyst, and the cyst wall blocked the right foramen of Monro. The cystic component of the tumor was resected using an Olympus VEF-V flexible neuroendoscope. The histological diagnosis was pituitary adenoma. The hydrocephalus improved rapidly and his consciousness became clear. After the operation, he was started on cabergoline. The tumor size subsequently decreased.

Conclusion

Prompt partial resection of the giant prolactinoma by transventricular neuroendoscopy resulted in early improvement of hydrocephalus with less invasiveness, allowing subsequent treatment with cabergoline.

Newborn with severe supratentorial subdural hematoma due to laceration of the tentorium cerebelli

PURPOSE

A rare case of a newborn girl born by a normal vaginal delivery who developed a severe supratentorial subdural hematoma due to a laceration in the tentorium cerebelli is presented.

METHODS AND RESULTS

The girl, born by normal vaginal delivery at 39 weeks and 4 days of gestation, showed an intermittent decrease in oxygen saturation and bulging of the anterior fontanelle. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a subdural hematoma centered in the left occipital region with a midline shift. Hematoma evacuation with craniotomy was performed, and the source of bleeding was a laceration of the tentorium cerebelli.

CONCLUSION

Severe supratentorial subdural hematomas can occur due to laceration of the tentorium cerebelli even in a normal vaginal delivery.

ML-4 POLICY CHANGE TO PCNSL TREATMENT LED BY HEMATOLOGY, AND INITIAL TREATMENT RESULTS

In the treatment of PCNSL, chemotherapy is becoming the main treatment, in a while, radiation therapy is becoming to be avoided. In our hospital, hematology leads an initiative to the treatment of PCNSL from 2021. During the 7 years from 2016, there were 32 cases of PCNSL that underwent initial treatment at our hospital, of which 8 cases occurred after 2021. The breakdown was 6:2 male to female, and the average age was 71.3 years. In 5 relatively young patients, remission was induced with 5 to 6 courses of R-MPV therapy, 3 of which received high-dose chemotherapy combined with autologous peripheral blood stem cell transfusion, all of whom avoided RT and have maintained remission. In 3 older patients, only RT was performed in 1 and HD-MTX therapy was performed in 2, of which RT was combined in 1 and BSC was introduced due to treatment related sepsis in another patient. Although the follow-up period was short, there has been no recurrence except for one patient who became BSC. On the other hand, in 24 patients before 2020, HD-MTX therapy combined with RT was performed in all patients, except for 1 patient who underwent RT only due to advanced age and 1 patient who died before treatment due to poor general condition. Recurrence was observed in 8 cases, and additional RT and chemotherapy were performed. Although no recurrence was seen in 16 cases, there are only 4 patients who had been still followed up, 6 died, and 6 had unknown or BSC, with a poor prognosis. One of the reasons was thought to be related to the decrease in ADL due to radiation injury. In the absence of recurrence, ADL may be maintained long-term in young patients. On the other hand, elderly people cannot avoid RT, which is still a problem.

Endogenous protein and enzyme fragments induce immunoglobulin E-independent activation of mast cells via a G protein-coupled receptor, MRGPRX2

Mast cells play a central role in inflammatory and allergic reactions by releasing inflammatory mediators through 2 main pathways, immunoglobulin E-dependent and E-independent activation. In the latter pathway, mast cells are activated by a diverse range of basic molecules (collectively known as basic secretagogues) through Mas-related G protein-coupled receptors (MRGPRs). In addition to the known basic secretagogues, here, we discovered several endogenous protein and enzyme fragments (such as chaperonin-10 fragment) that act as bioactive peptides and induce immunoglobulin E-independent mast cell activation via MRGPRX2 (previously known as MrgX2), leading to the degranulation of mast cells. We discuss the possibility that MRGPRX2 responds various as-yet-unidentified endogenous ligands that have specific characteristics, and propose that MRGPRX2 plays an important role in regulating inflammatory responses to endogenous harmful stimuli, such as protein breakdown products released from damaged or dying cells.

Uncoupling Action of Antibiotic Sporaviridins with Rat-liver Mitochondria

The effects of the glycoside antibiotic sporaviridins (SVDs) on oxidative phosphorylation of rat-liver mitochondria were examined. SVDs released state 4 respiration, dissipated transmembrane electrical potential, and accelerated ATPase activity. These facts demonstrated that SVDs are potent uncouplers of oxidative phosphorylation. During the uncoupling caused by SVDs, large amplitude swelling and oxidation of intramitochondrial NAD(P)H occurred, suggesting that SVDs greatly enhanced nonspecific permeability of the inner mitochondrial membrane. It is suggested that the uncoupling action of SVDs might be caused by dissipation of proton electrochemical potential due to an increase in the permeability of inner mitochondrial membrane.

Molecular characterization and chromosomal localization of cytochrome P450 genes involved in the biosynthesis of cyclic hydroxamic acids in hexaploid wheat

The cyclic hydroxamic acids, 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA) and 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), are defensive secondary metabolites found in gramineous plants including wheat, maize and rye. cDNAs for five cytochromes P450 (P450s) involved in DIBOA biosynthesis (CYP71C6, CYP71C7v2, CYP71C8v2, CYP71C9v1 and CYP71C9v2) were isolated from seedlings of hexaploid wheat [( Triticum aestivum L. cv. Chinese Spring (2n=6x=42, genomes AABBDD)] by RT-PCR and screening of a cDNA library. CYP71C9v1 and CYP71C9v2 are 97% identical to each other in amino acid and nucleotide sequences. The cloned P450 species showed 76-79% identity at the amino acid level to the corresponding maize P450 species CYP71C1-C4, which are also required for DIBOA biosynthesis. The wheat P450 cDNAs were heterologously expressed in the yeast ( Saccharomyces cerevisiae) strain AH22. Microsome fractions from yeast cells expressing these P450 species catalyzed the same reactions as their maize orthologs. The chromosomes carrying the cyp71C6- C9v1 orthologs were identified by Southern hybridization using aneuploid lines of Chinese Spring wheat. The cyp71C9v1 orthologs were located on the chromosomes of wheat homoeologous group-4. The orthologs of the other P450 genes, cyp71C7v2, cyp71C6 and cyp71C8v2, were located on group-5 chromosomes. The same P450 genes were also present in the three ancestral diploid species of hexaploid wheat, T. monococcum (AA), Aegilops speltoides [BB (approximately SS)] and Ae. squarrosa (DD).

Prophylactic effect of JTE-607 on LPS-induced acute lung injury in rats with CINC-1 inhibition

OBJECTIVE AND DESIGN

JTE-607, a multiple cytokine inhibitor, was evaluated in lipopolysaccharide (LPS)-induced acute lung injury in rats in vivo and in vitro.

MATERIALS AND METHODS

LPS instillation into airways of rats was performed. JTE-607 at 3-30 mg/kg and dexamethasone at 3 mg/kg were administered intravenously at 10 min and 0 min for JTE-607, and 60 min for dexamethasone prior to the LPS instillation (n = 8). Cytokine-induced neutrophil chemoattractant (CINC)-1 level and myeloperoxidase (MPO) activity in lung were measured at 4 h after LPS instillation, and at 24 h for lung wet weight measurement and histological study. LPS-induced CINC-1 production by rat alveolar macrophages were also measured in vitro.

RESULTS

JTE-607 and dexamethasone showed a significant reduction of increased CINC-1 level and MPO activity in lung after LPS treatment in vivo. Increased wet weight was also significantly inhibited. Histological studies revealed that JTE-607 and dexamethasone significantly inhibited LPS-induced accumulation of peribronchial neutrophils and eosinophils, and perivascular edema. JTE-607 and dexamethasone suppressed CfNC-1 synthesis by rat alveolar macrophages in vitro with IC50 values of 12.4 microM and 2.3 nM, respectively.

CONCLUSIONS

These results indicate that JTE-607 has an inhibitory effect on LPS-induced rat lung inflammation in parallel with CINC-1 reduction. The effect of JTE-607 was suggested to be through direct inhibition of CINC-1 production from rat alveolar macrophages. JTE-607 may thus be efficacious in cytokine-mediated lung inflammation such as acute respiratory distress syndrome.

Ferromagnetic exchange coupling of vanadium(IV) dpi spins across pyrimidine rings: dinuclear complexes of oxovanadium(IV) bis(1,1,1,5,5,5-hexafluoropentane-2,4-dionate) bridged by pyrimidine derivatives

Dinuclear oxovanadium(IV) complexes bridged by pyrimidine derivatives, L[VO(hfac)(2)](2) [L = pyrimidine (PM), 4-methylpyrimidine (MPM), 4,6-dimethylpyrimidine, 4-aminopyrimidine, and quinazoline; hfac = 1,1,1,5,5,5-hexafluoropentane-2,4-dionate], were synthesized and characterized. All of them showed intramolecular ferromagnetic interaction, and the magnetic susceptibilities were analyzed on the basis of the singlet-triplet model, giving 2J/k(B) = 2.2-5.5 K. PM[VO(hfac)(2)](2) crystallized in a monoclinic space group C2/c with a = 34.092(2), b = 6.9783(4), and c = 16.4940(9) A, beta = 109.104(1) degrees, V = 3707.8(4) A(3), and Z = 4 for C(24)H(8)F(24)N(2)O(10)V(2), and MPM[VO(hfac)(2)](2) gave isomorphous crystals. A semiempirical calculation study based on the determined structure suggests the presence of dpi-ppi interaction between vanadium and pyrimidine nitrogen atoms. Ferromagnetic coupling is explained in terms of a spin-polarization mechanism across the pyrimidine bridge. The intermolecular ferromagnetic interaction of PM[VO(hfac)(2)](2) can be interpreted by the contact between the spin-polarized pyrimidine moiety and the oxovanadium oxygen atom in an adjacent molecule.

[Malignant fibrous histiocytoma originating in a renal capsule: a case report]

We report a case of malignant fibrous histiocytoma originating in a renal capsule. A 43-year-old woman was admitted with a chief complaint of right lower abdominal pain. Physical examination was unremarkable. Serum C-reactive protein and erythrocyte sedimentation rate increased to 3.8 mg/dl and 60 mm/hr., respectively. Computed tomography (CT) and magnetic resonance image (MRI) showed a heterogeneous enhanced mass, 4 x 9 x 13 cm in size, in contact with the lateral part of the right kidney. Selective right renal arteriography revealed a hypovascular tumor, the main feeding artery of which was the right adrenal artery. Preoperative clinical diagnosis was a retroperitoneal sarcoma and transabdominal tumor resection was performed. The adhesion between the tumor and the right kidney was so severe that right nephrectomy was also necessary for a radical surgery. The tumor, measuring 13 x 9 x 6 cm, was located laterally adhering to the right renal capsule. Microscopic examination of the tumor demonstrated spindle-shaped fibroblast-like cells arranged in a storiform pattern with fibrous stroma and clusters of rounded histiocyte-like cells and pleomorphic giant cells with bizarre nuclei. Histopathological diagnosis was malignant fibrous histiocytoma arising from the renal capsule and there was no tumor invasion to renal parenchyma. No adjuvant therapy was performed but she has remained well for 31 months since the operation without evidence of disease.

Induction of hydroxycinnamic acid amides and tryptophan by jasmonic acid, abscisic acid and osmotic stress in barley leaves

The effects of jasmonic acid (JA) and abscisic aid (ABA) on secondary metabolism in barley (Hordeum vulgare L.) were investigated. Treatment with JA at 100 microM for 48 h induced accumulation of four compounds in barley primary leaves. The accumulation of these compounds was also observed after treatment with ABA at 100 microM. The induced compounds were identified as p-coumaroylputrescine, p-coumaroylagmatine, p-coumaroyl-3-hydroxyagmatine and tryptophan by spectroscopic methods. The profiles of compounds induced by application of JA and ABA were different. JA exhibited stronger inducing activity for hydroxycinnamic acid amides than ABA, while ABA was more active in tryptophan accumulation. The major hydroxycinnamic acid amides in JA- and ABA-treated leaves were p-coumaroylagmatine and p-coumaroyl-3-hydroxyagmatine, respectively. These differences suggested that JA and ABA act in distinct modes. The induction of these compounds was also observed in leaf segments treated with 1 M sorbitol and glucose. These findings suggested that JA and ABA are involved in accumulation of hydroxycinnamic acid amides and tryptophan in response to osmotic stress in barley.

[Multiple primary cancers limited to the urological field]

We analyzed the clinical features of multiple primary cancers arising from the urogenital organs. Between January 1980 and December 1999, 300 patients with renal cell carcinoma (RCC), 661 patients with urothelial carcinoma (bladder cancer and renal pelvic-ureteral cancer) (TCC) and 391 patients with prostate cancer (PC) were treated at our hospital. Of these patients, 20 patients had double genitourinary cancers. The double cancers consisted of RCC and TCC in 1 case, RCC and PC in 6 cases, and TCC and PC in 13 cases. Seven cases had synchronous tumors. The average interval in the metachronous cases was 68 (range: 12-209) months. The age at diagnosis of the second cancer was 68-94 (mean: 77.6) years old. The follow-up period ranged from 4-168 (mean: 38) months; Six patients are alive with no evidence of disease and 6 patients died of cancer. Even when limited to the urological section, the frequency of multiple primary cancers is increasing.

Results of combined-modality therapy for primary and secondary malignant lymphoma of the central nervous system (CNS)

PURPOSE

We consider that whatever the vital prognosis of secondary CNS lymphoma (SCNSL), its local control is as serious as that of primary CNS lymphoma (PCNSL). In this study, both the treatment outcomes and local control of patients with SCNSL and PCNSL were compared, with the aim of improving the treatment of SCNSL.

MATERIALS AND METHODS

This study included 11 patients with PCNSL and 14 with SCNSL treated from January 1984 to October 1997. PCNSL patients underwent partial tumor resection and received systemic chemotherapy. All SCNSL patients received systemic chemotherapy, and eight also received intrathecal anticancer drug infusion. Nine PCNSL patients and 11 SCNSL patients underwent whole-brain radiation therapy with 4-MV photons. Among the SCNSL patients, three patients underwent localized-brain irradiation and two patients also received whole-spine irradiation.

RESULTS

Five-year survival rates were 34% for PCNSL and 33% for SCNSL. In SCNSL, survival times after CNS involvement were very short, irrespective of treatment. One-year local control rates after CNS irradiation were 38% for PCNSL and 14% for SCNSL. Recurrence was mainly found in the cranial region, in seven of 11 PCNSL patients and 10 of 14 SCNSL patients.

CONCLUSIONS

Patients with SCNSL had a poor prognosis, and local control in them was more problematic than in patients with PCNSL. It is necessary to develop new combined modality therapy for patients with SCNSL,including the participation of a radiation oncologist, before the disease becomes progressive.

Induced accumulation of 2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-one glucoside (HDMBOA-Glc) in maize leaves

Accumulation of 2-(2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-one)-beta-D-glucopyranose (HDMBOA-Glc) was induced in maize leaves by treatment with CuCl2, chitopentaose, penta-N-acetylchitopentaose, or jasmonic acid (JA). The accumulation of HDMBOA-Glc was accompanied by a decrease in level of 2-(2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one)-beta-D-glucopyranose (DIMBOA-Glc). When the leaf segments were treated with JA in the presence of [Me-2H3]L-methionine, the label was efficiently incorporated into HDMBOA-Glc, while no incorporation into DIMBOA-Glc or HMBOA-Glc was detected, suggesting the conversion of constitutive DIMBOA-Glc to HDMBOA-Glc by methylation at the 4-position. Levels of endogenous JA and its leucine conjugate transiently increased prior to the accumulation of HDMBOA-Glc in leaf segments treated with CuCl2 and chitopentaose. The lipoxygenase inhibitor ibuprofen suppressed the accumulation of HDMBOA-Glc induced by CuCl2 treatment, and the reduced accumulation of HDMBOA-Glc was recovered by addition of JA. These findings suggested that JA functions as a signal transducer in the induction of HDMBOA-Glc accumulation.

Elicitor-induced changes in isoflavonoid metabolism in red clover roots

When roots of 5-d-old red clover (Trifolium pratense L.) seedlings were treated with chitohexaose and CuCl(2), constitutive glucosidic conjugates of formononetin (F) and (-)-maackiain (Ma) promptly disappeared. Free F and Ma, which were not detected in the control tissues, rapidly appeared to reach the maximum levels 24 h after the initiation of treatment and then declined. The pattern of appearance and disappearance was the same between the tissues treated with chitohexaose and CuCl(2). The enzyme activities related to isoflavonoid metabolism were investigated using crude extracts from elicitor-treated roots. The conjugate-forming glucosyltransferase and malonyltransferase activities were lost or markedly reduced after elicitor treatment. On the other hand, malonylesterase and glucosidase activities remained unchanged or showed only slight increase. Phenylalanine ammonia-lyase activity disappeared following elicitor treatment. These results indicated that free aglycones were produced from the conjugate pool by hydrolysis under conditions in which the biosynthetic pathway was extinguished. The amount of Ma produced did not explain that of MaGM lost (about 45%). Since Ma, but not its conjugates, served as a substrate for peroxidase from the elicitor-treated roots, Ma was considered to be converted to insoluble materials.

In vitro and in vivo pharmacological characterization of JTE-907, a novel selective ligand for cannabinoid CB2 receptor

JTE-907 [N-(benzo[1,3]dioxol-5-ylmethyl)-7-methoxy-2-oxo-8-pentyloxy-1,2-dihydroquinoline-3-carboxamide] was evaluated in vitro and in vivo as a novel selective ligand for cannabinoid receptor of peripheral type (CB2). The compound binds with high affinity to human CB2 or mouse CB2 expressed on CHO cell membrane and to rat CB2 on splenocytes. The K(i) affinities for human, mouse, and rat CB2 were 35.9, 1.55, and 0.38 nM, respectively. The selectivity ratio for the CB2 receptors compared with central nervous type receptors (CB1) of human (expressed on CHO cells), and mouse and rat CB1 on cerebellum were 66, 684, and 2760, respectively. JTE-907 showed concentration-dependent increase of forskolin-stimulated cAMP production in CHO cells expressing human and mouse CB2 in vitro, i.e., JTE-907 behaved as an inverse agonist, which is in contrast to Win55212-2 that reduces cAMP as an agonist. JTE-907 dosed orally inhibited carrageenin-induced mouse paw edema dose dependently. The same in vivo effect was observed with other cannabinoid receptor ligands such as SR144528, Delta(9)-tetrahydrocannabinol (THC), and Win55212-2. This is the first report that a CB2-selective inverse agonist, JTE-907, has an anti-inflammatory effect in vivo, and how the inverse agonist showed the same effect as Win55212-2 and Delta(9)-THC is discussed.

Definition of crucial structural factors of acetogenins, potent inhibitors of mitochondrial complex I

Some natural acetogenins are the most potent inhibitors of bovine heart mitochondrial complex I. These compounds are characterized by two functional units (i.e. hydroxylated tetrahydrofuran (THF) and alpha,beta-unsaturated gamma-lactone ring moieties) separated by a long alkyl spacer. To elucidate which structural factors of acetogenins including their active conformation are crucial for the potent inhibitory effect, we synthesized a series of novel acetogenin analogues possessing bis-THF rings. The present study clearly demonstrated that the natural gamma-lactone ring is not crucial for the potent inhibition, although this moiety is the most common structural unit among a large number of natural acetogenins and has been suggested to be the only reactive species that directly interacts with the enzyme (Shimada et al., Biochemistry 37 (1998) 854-866). The presence of free hydroxy group(s) in the adjacent bis-THF rings was favorable, but not essential, for the potent activity. This was probably because high polarity (or hydrophilicity), rather than hydrogen bond-donating ability, around the bis-THF rings is required to retain the inhibitor in the active conformation. Interestingly, length of the alkyl spacer proved to be a very important structural factor for the potent activity, the optimal length being approximately 13 carbon atoms. The present study provided further strong evidence for the previous proposal (Kuwabara et al., Eur. J. Biochem. 267 (2000) 2538-2546) that the gamma-lactone and THF ring moieties act in a cooperative manner on complex I with the support of some specific conformation of the spacer.

Occurrence and characterization of a UDP-glucose:hydroxamic acid glucosyltransferase isolated from wheat (Triticum aestivum) seedlings

Cyclic hydroxamic acid glucosides are present at high concentrations immediately after germination in wheat (Triticum aestivum L.). Changes in the activity of UDP-Glucose:cyclic hydroxamic acid glucosyltransferase (EC 2.4.1.-) in wheat were investigated using the cyclic hydroxamic acids 2.4-dihydroxy-1,4-benzoxazin-3-one (DIBOA) and its 7-methoxy derivative (DIMBOA) as sugar acceptors. Glucosyltransferase activity on both substrates was detected in dry seeds, with activity increasing after imbibition, peaking in shoots and roots 36-48 hours after imbibition and decreasing thereafter. The transience of glucosyltransferase activity was concurrent with the transient occurrence of the hydroxamic acid glucosides [Nakagawa E., Amano T., Hirai N., and Iwamura H. (1995) Phytochemistry 38, 1349-1354], suggesting that glucosyltransferases regulate the accumulation of hydroxamic acid glucosides in wheat seedlings. Two peaks in activity of UDP-Glucose:DIMBOA glucosyltransferase were detected using a Mono Q column, indicating the presence of at least two isozymes of this glucosyltransferase. The enzyme in the major peak was purified about 1500-fold and shown to be in a monomeric form with a molecular mass of 47 or 49 kDa. The enzyme reacted strongly with DIMBOA, less so with DIBOA. The enzyme of the minor peak on the Mono Q chromatogram, which was also a monomeric enzyme with a molecular mass of 47 kDa, showed similar substrate specificity to that of the major peak enzyme.

Molecular structures and magnetic properties of the mixed-ligand complexes of bis(hexafluoroacetylacetonato)manganese(II), -copper(II), and -zinc(II) with 4,4'-bis(N-tert-butyl-N-oxylamino)-2,2'-bipyridine. Isosceles triangular hetero-three-spin systems consisting of aminoxyls and metal ions

4,4'-Bis(N-tert-butyloxylamino)-2,2'-bipyridine (4) and its 1:1 complexes with bis(hexafluoroacetylacetonato)manganese(II), -copper(II), and -zinc(II) were prepared. An X-ray structure analysis of free ligand 4 reveals that the molecule has a trans conformation with Ci symmetry and the aminoxyl radical center has a short contact of 2.36 A with one of the neighboring molecules. The three 1:1 complexes have mutually similar molecular structures in which the 2,2'-bipyridine moiety has a cis conformation and serves as a bidentate ligand and coordination geometry around the metal atom is a distorted octahedron. The EPR experiments for free ligand 4 and [Zn(hfac)2.4] in frozen solution suggested that the exchange couplings between the two aminoxyls (R) through the 2,2'-bipyridine rings are antiferromagnetic with JR-R/kB = -19.3 +/- 0.5 and -24.3 +/- 0.4 K, respectively. Isosceles triangular three-spin models were applied to the 1:1 magnetic metal complexes to give JR-M/kB = -19.1 +/- 0.2 K and JR-R/kB = -32.9 +/- 0.3 K for [Mn(hfac)2.4] and JR-M/kB = +73 +/- 18 K and JR-R/kB = -24.5 +/- 6.5 K for [Cu(hfac)2.4].

Purification and characterization of a beta-glucosidase from rye (Secale cereale L.) seedlings

Cyclic hydroxamic acids and a glucosidase that occur in rye seedlings were investigated. The concentration of the glucoside of 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA-Glc) in shoots increased soon after germination and decreased to a lower, constant level as the plants started autotrophic growth. Cyclic hydroxamic acid glucoside beta-glucosidase activity also occurred transiently, and the timing of the increase and decrease was concurrent with that of cyclic hydroxamic acid glucosides. The glucosidase was isolated from 48-h-old rye shoots and purified to apparent homogeneity by using isoelectric precipitation, anion exchange chromatography, and gel filtration. The isoelectric point and the optimum reaction temperature were 4.9-5.1 and 25-30 degrees C, respectively. The N-terminal amino acid sequence was almost identical to that of the wheat glucosidases, but did not show any similarity to the sequences of other glucosidases of plant origin. SDS- and native-PAGE analyses showed that rye had several isozymes of glucosidase, and each isozyme was an oligomer of 60-kDa monomers with a molecular mass of approximately 300 kDa. The enzyme was highly active not only for DIMBOA-Glc but also for its 7-demethoxy analogue, DIBOA-Glc, which was different from the specificities of maize and wheat glucosidases.

Induction of clovamide by jasmonic acid in red clover

The effect of jasmonic acid (JA) on the secondary metabolism of 5-day-old red clover seedlings was investigated. Induction of the formation of four compounds was found in roots after treatment with 50 microM JA for 48 h, while no induction was observed in the shoots. These compounds, whose formation was induced by JA addition, were isolated and identified as caffeoyl DOPA (clovamide), caffeoyltyrosine, p-coumaroyl DOPA and p-coumaroyltyrosine, by ion-spray MS and 1H NMR analyses, and by chemical synthesis. Among them, clovamide was the most abundant, while the other amides represented only a minor portion. Clovamide started to increase in amount 24-36 h after treatment and reached a maximum after 96 h (2.81 nmol/mg fr. wt.). The induction of their formation was observed even with 5 microM of JA, and the amount increased with concentrations up to 100 microM. Treatment with 1 mM CuCl2, which elicits accumulation of the phytoalexin maackiain in red clover, caused a decrease in clovamide amount.

Induction of N-hydroxycinnamoyltyramine synthesis and tyramine N-hydroxycinnamoyltransferase (THT) activity by wounding in maize leaves

Both N-p-coumaroyl- and N-feruloyltyramine accumulated in response to wounding in leaf segments of maize. The amount of N-hydroxycinnamoyltyramines started to increase 3-6 h after wounding and peaked at 12 h. Thereafter, the amount of N-p-coumaroyltyramine decreased rapidly, while the N-feruloyltyramine content remained at a high level. The accumulation of N-hydroxycinnamoyltyramines was accompanied by an increase in the tyramine N-hydroxycinnamoyltransferase (THT) activity. This increase was initially detected 3 h after wounding and reached a maximum at 36 h, the level of activity being 40 and 11 times that in the leaves before wounding and in the control leaves, respectively. Partial purification of THT from wounded leaves by (NH4)2SO4 precipitation and subsequent two steps of anion-exchange chromatography resulted in a 12.5-fold increase in specific activity. Kinetic studies with this partially purified enzyme revealed that the best substrates were tyramine and feruloyl-CoA, although tryptamine and sinapoyl-CoA also efficiently served as substrates. The apparent native molecular weight of the enzyme was determined by gel filtration as 40 kDa.

Design syntheses and mitochondrial complex I inhibitory activity of novel acetogenin mimics

Some natural acetogenins are the most potent inhibitors of mitochondrial complex I. These compounds are characterized by two functional units [i.e. hydroxylated tetrahydrofuran (THF) and alpha, beta-unsaturated gamma-lactone ring moieties] separated by a long alkyl spacer. To elucidate which structural factors of acetogenins, including their active conformation, are crucial for the potent inhibitory activity we synthesized a novel bis-acetogenin and its analogues possessing two gamma-lactone rings connected to bis-THF rings by flexible alkyl spacers. The inhibitory potency of the bis-acetogenin with bovine heart mitochondrial complex I was identical to that of bullatacin, one of the most potent natural acetogenins. This result indicated that one molecule of the bis-acetogenin does not work as two reactive inhibitors, suggesting that a gamma-lactone and the THF ring moieties act in a cooperative manner on the enzyme. In support of this, either of the two ring moieties synthesized individually showed no or very weak inhibitory effects. Moreover, combined use of the two ring moieties at various molar ratios exhibited no synergistic enhancement of the inhibitory potency. These observations indicate that both functional units work efficiently only when they are directly linked by a flexible alkyl spacer. Therefore, some specific conformation of the spacer must be important for optimal positioning of the two units in the enzyme. Furthermore, the alpha,beta-unsaturated gamma-lactone, the 4-OH group in the spacer region, the long alkyl tail attached to the THF unit and the stereochemistry surrounding the hydroxylated bis-THF rings were not crucial for the activity, although these are the most common structural features of natural acetogenins. The present study provided useful guiding principles not only for simplification of complicated acetogenin structure, but also for further wide structural modifications of these molecules.

Multivariate analysis of prognostic determinants after surgery for renal cell carcinoma at Himeji National Hospital

A clinico-pathological study was performed retrospectively on 62 patients who underwent surgery for renal cell carcinoma between January 1992 and October 1998 at Himeji National Hospital to clarify the prognostic determinants for survival. The median follow-up period was 32 months and the cause-specific survival rates at 1, 3 and 5 years were 86.7, 81.3, 81.3%, respectively. Of the 62 patients, 11 (17.7%) patients died of renal cell carcinoma and 2 (3.2%) patients died of unrelated causes. Of the variables related to survival, presenting symptoms, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), alkaline phosphatase (ALP), tumor size, pathological tumor grade, infiltration pattern, pathological tumor stage, N classification and M classification were significant risk factors for survival by univariate analysis. However, ALP, N classification and M classification were significant for survival as determined by the step-wise procedure and M classification was the most significant factor according to Cox's proportional hazard model analysis.

JTE-522 selectively inhibits cyclooxygenase-2-derived prostaglandin production in inflammatory tissues

OBJECTIVE AND DESIGN

To investigate the effect of JTE-522, a selective cyclooxygenase (COX)-2 inhibitor, on prostaglandin (PG) production and COX expression in rats.

SUBJECTS

Male rats (4-8 weeks old) were used for in vivo experiments, while for in vitro assay, rat peritoneal macrophages were used.

TREATMENT

JTE-522 (1-100 mg/kg) and indomethacin (0.03-10 mg/kg) were administered orally. JTE-522 and reference compounds (0.01-10 microM) were subjected to COX expression.

RESULTS

JTE-522 inhibited the development of carrageenin-induced paw edema and PGE2 production in inflammatory paws at a dose of 10 mg/kg. On the other hand, JTE-522 (1-100 mg/kg) did not affect A23187-stimulated thromboxane B2 release from whole blood or the PGE2 level in gastric mucosa. JTE-522 did not suppress lipopolysaccharide-induced COX-2 expression in peritoneal macrophages.

CONCLUSION

These results indicate that JTE-522 selectively inhibits PG production mediated by COX-2 in inflammatory tissues. JTE-522 may thus represent a novel type of anti-inflammatory drug without adverse effects on the gastro-intestinal tract.

Purification and characterization of a hydroxamic acid glucoside beta-glucosidase from wheat (Triticum aestivum L.) seedlings

A beta-glucosidase (EC 3.2.1.21) with a high affinity for cyclic hydroxamic acid beta-D-glucosides was purified from 48-h-old wheat (Triticum aestivum L.) seedlings. The activity occurred transiently at a high level during the non-autotrophic stage of growth, and the nature of the transient occurrence was correlated with that of 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one glucoside (DIMBOA-Glc). The glucosidase had maximum activity at an acidic pH (pH 5.5) and the purified enzyme showed a high affinity for DIMBOA-Glc, Vmax and Km being 4100 nkat/mg protein and 0.27 mM, respectively. It also hydrolyzed p-nitrophenol beta-glycosides, as well as flavone and isoflavone glucosides, but to a lesser extent. The results indicated that the primary natural substrate for the glucosidase is DIMBOA-Glc and that the enzyme is involved in defense against pathogens and herbivores in non-autotrophic wheat. The glucosidase was found to be present as oligomeric forms with a molecular mass of 260-300 kDa comprising 60- and 58-kDa monomers. The N-terminal 12-amino-acid sequences of the two monomers were identical (Gly-Thr-Pro-(Ser?)-Lys-Pro-Ala-Glu-Pro-Ile-Gly-Pro), and showed no similarity to those of other plant glucosidases. Polyacrylamide gel electrophoresis under nondenaturing condition indicated the existence of at least eight isozymes. Three cultivars of Triticum aestivum had the same zone of glucosidase activity on zymograms, but the activity zones of the Triticum species, T. aestivum L., T. spelta L. and T. turgidum L., had different mobilities.

Occurrence of avenanthramides and hydroxycinnamoyl-CoA:hydroxyanthranilate N-hydroxycinnamoyltransferase activity in oat seeds

Oat phytoalexins, avenanthramides, occur as constitutive components in seeds. The amounts of each avenanthramide were analyzed. The composition of avenanthramides in dry seeds was different from that in elicitor-treated leaves. In seeds, avenanthramide C was most abundant with an amount two times larger than that of avenanthramide A or B. On the other hand, avenanthramide A was the major component in elicitor-treated leaves. The total amount of avenanthramides in seeds increased 2.5 times during imbibition for 48 h although the composition did not change. The hydroxycinnamoyl-CoA:hydroxyanthranilate N-hydroxycinnamoyltransferase (HHT, EC 2.3.1.-) activity, which is responsible for the final condensation step in the avenanthramide biosynthesis, was detected in dry seeds. The activity was localized in endosperm and scutellum, and slightly increased during 48-h imbibition. The enzyme was partially purified by anion exchange chromatography from both dry seeds and elicitor-treated leaves The activity was separated into two peaks by chromatography, indicating that HHT consists of at least two isoforms. The substrate specificities of HHT isoforms from seeds were different from each other.

Origin of selective inhibition of mitochondrial complex I by pyridinium-type inhibitor MP-24

Positively charged pyridiniums are unique inhibitors to probe the structural and functional properties of the ubiquinone reduction site of bovine heart mitochondrial complex I. In this study, we synthesized a series of neutral as well as pyridinium analogues of MP-24 (N-methyl-4-[2-methyl-2-(p-tert-butylbenzyl)propyl]pyridinium), a selective inhibitor of one of the two proposed binding sites of these pyridinium-type inhibitors of complex I (H. Miyoshi et al., J. Biol. Chem. 273 (1998) 17368-17374), to elucidate the origin of its selectivity. Inhibitory potencies of all neutral and pyridinium analogues with tetraphenylboron (TPB(-)), which forms an ion-pair with pyridiniums, were comparable, although the degrees of selective inhibition by pyridiniums without TPB(-) were entirely different. In contrast to MP-24, the dose-response curves of nonselective pyridiniums and all neutral analogues were not affected by incubation conditions. These results strongly suggested that the process of the inhibitor passage to the binding sites is responsible for the selective inhibition.

[Small cell neuroendocrine carcinoma of the urinary bladder: a case report]

A 60-year-old male was referred to our hospital with a complaint of asymptomatic gross hematuria. Cystoscopic examination revealed a non-papillary broad-based tumor on the posterior wall of the urinary bladder. Computed tomography revealed no evidence of metastases. Transurethral resection of bladder tumor (TUR-BT) was performed and muscle invasion was detected by histological examination of the specimen. Total cystectomy and ileal conduit formation were performed at the preoperative diagnosis of T2-3N0M0. Hematoxylin-eosin staining of the specimen revealed small cancer cells with hyperchromatic nucleus and scanty cytoplasm growing in the muscle layer of the urinary bladder and in the left obturator lymph nodes. Immunohistochemistry for neurospecific enolase showed diffuse staining in the cytoplasm of cancer cells, and ultrastructural study showed dense core granules. From these findings, the patient was diagnosed with small cell neuroendocrine carcinoma of the urinary bladder at the stage of pT3bpN1M0. Three courses of adjuvant chemotherapies with cis-platinum (CDDP) and etoposide were administered. The patient is still alive with no evidence of any recurrence at 22 months after the operation. This case suggests that treatment with combined total cystectomy and adjuvant CDDP and etoposide chemotherapies is effective against neuroendocrine carcinoma of the urinary bladder with regional lymph node metastases.

JTE-607, a novel inflammatory cytokine synthesis inhibitor without immunosuppression, protects from endotoxin shock in mice

OBJECTIVE AND DESIGN

We investigated the effect of a novel N-benzoyl-L-phenylalanine derivative compound (JTE-607) on production of various cytokines and other immune responses in vitro and on endotoxin shock in vivo.

MATERIALS AND METHODS

Human, monkey, rabbit, mouse and rat peripheral blood mononuclear cells (PBMCs), and human fibroblasts, umbilical vein endothelial cells (HUVEC), mesangial cells and T cells were used in vitro. Endotoxin shock was induced by lipopolysaccharide (LPS) in Corynebacterium parvum (C. parvum) sensitized male C57BL/6 mice in vivo.

RESULTS

JTE-607 inhibited inflammatory cytokine production, including tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6, IL-8 and IL-10, from LPS-stimulated human PBMCs, with IC50 values of 11, 5.9, 8.8, 7.3 and 9.1 nM, respectively. The inhibitory effects of JTE-607 were also seen in mRNA expression of those cytokines. The potency of JTE-607 on cytokine production from PBMCs of other species, and from other human cells were much lower than that on human PBMCs. JTE-607 did not affect either LPS-stimulated microbead phagocytosis or reactive oxygen species production at 1 microM in human PBMCs but slightly suppressed expression of major histocompatibility complex class II antigen at 1 microM, although it was 100-fold less active than it was as a cytokine inhibitor. JTE-607 (0.3-10 mg/kg, i.v.) showed dose dependent inhibition of mortality after LPS challenge in C. parvum sensitized mice in accordance with a decrease of plasma TNF-alpha.

CONCLUSIONS

These results suggest that JTE-607 is a multiple cytokine inhibitor specific for human PBMCs. This compound may be useful for the treatment of various cytokine mediated diseases such as septic shock without causing immunosuppression.

Topographical characterization of the ubiquinone reduction site of glucose dehydrogenase in Escherichia coli using depth-dependent fluorescent inhibitors

Membrane-bound glucose dehydrogenase in Escherichia coli possesses a binding site for ubiquinone as well as glucose, metal ion and pyrroloquinoline quinone. To probe the depth of the ubiquinone binding site in the membrane environment, we synthesized two types of fluorenyl fatty acids which bear an inhibitor mimic moiety (i.e., specific inhibitor capsaicin) close to the fluorene located at different positions in the alkyl tail chain; one close to the polar carbonyl head group (alpha-(3, 4-dimethoxyphenyl)acetyloxy-7-nonyl-2-fluoreneacetic acid, alpha-DFA), and the other in the middle of the chain (theta-(3, 4-dimethoxyphenyl)acetyloxy-7-ethyl-2-fluorenenonanoic acid, theta-DFA). Mixed lipid vesicles consisting of phosphatidylcholine (PC) and alpha-DFA or theta-DFA were prepared by sonication method, and fluorescent quenching against a hydrophilic quencher, iodide anion, was examined. The vesicles containing alpha-DFA were more susceptible to quenching than those containing theta-DFA, indicating that the fluorene and consequently capsaicin mimic moiety are located at different depths in the lipid bilayer depending upon the position of attachment to the alkyl tail chain. The purified glucose dehydrogenase was reconstituted into PC vesicles which consisted of PC and alpha-DFA or theta-DFA with various molar ratios. For both types of reconstituted vesicles, the extent of inhibition of short-chain ubiquinone reduction activity increased with increases in the molar ratio of fluorenyl fatty acid to PC. The ubiquinone reduction activity was more significantly inhibited in the reconstituted vesicles containing alpha-DFA compared to those containing theta-DFA. Our findings strongly suggested that the ubiquinone reduction site in glucose dehydrogenase is located close to the membrane surface rather than in the hydrophobic membrane interior.

[A case of genital Paget's disease with severe dermal invasion and early dissemination]

A 65-year-old man was referred to our hospital with a complaint of a scrotal mass which he first noticed 8 months ago. The mass was resected saving genital organs. Pathological diagnosis was extramammary Paget's disease with severe dermal invasion and many nuclear mitoses. The tumor was 15 mm in diameter, and 18 mm in thickness. The bilateral inguinal lymph nodes were dissected and multiple metastases were revealed in the right specimen. Since paraaortic lymph node metastases were detected later 5 cycles of chemotherapy consisting of cyclophosphamide, adriamycin and cisplatin (CAP) followed by radiation therapy were performed. However, only a partial response could be obtained, and multiple brain metastases were revealed on computed tomographic scan. He died 22 months after discovery of this disease. Since extramammary Paget's disease tends to grow slowly and horizontally, cases with such severe dermal invasion and early dissemination as in our case are unusual.

Characterization of the ubiquinol oxidation sites in cytochromes bo and bd from Escherichia coli using aurachin C analogues

Natural aurachin C is the most potent inhibitor of oxidation of ubiquinols by cytochromes bo and bd from Escherichia coli. To probe the structural properties of the substrate oxidation site in the ubiquinol oxidases, we synthesized a systematic set of aurachin C analogues (N-hydroxy-4-quinolone derivatives) and examined how their structure affects their activity towards cytochromes bo and bd, which are structurally unrelated. We found that the presence of the 3-methyl group of the 2-n-decyl and 2-n-undecyl derivatives increased the inhibitory potency towards both enzymes, probably due to a local steric congestion that allows favorable interaction of the alkyl tail with the enzyme. Increase in the chain length of the 3-alkyl tail of the 2-n-undecyl derivatives decreased the inhibitory potency only in cytochrome bo, indicating that the binding site for the alkyl tails of cytochrome bo is smaller than that of cytochrome bd. Based on these findings, we discuss the differences in the molecular mechanism of substrate oxidation by these two terminal ubiquinol oxidases.

Role of the isoprenyl tail of ubiquinone in reaction with respiratory enzymes: studies with bovine heart mitochondrial complex I and Escherichia coli bo-type ubiquinol oxidase

The hydrophobic isoprene tail of ubiquinone-2 (Q2) exihibits binding specificity in redox reactions with bovine heart mitochondrial complex I (Ohshima, M., Miyoshi, H., Sakamoto, K., Takegami, K., Iwata, J., Kuwabara, K., Iwamura, H., and Yagi, T. (1998) Biochemistry 37, 6436-6445) and the Escherichia coli bo-type ubiquinol oxidase (Sakamoto, K., Miyoshi, H., Takegami, K., Mogi, T., Anraku, Y., and Iwamura, H. (1996) J. Biol. Chem. 271, 29897-29902). To identify the structural factor(s) of the diprenyl tail of Q2 governing the specific interaction with these enzymes, we synthesized a series of novel Q2 analogues in which only one of the structural factors of the diprenyl tail was systematically modified. In bovine complex I, the presence of the methyl branch and the pi-electron system in the first isoprene unit are responsible for high-affinity binding of Q2 to the ubiquinone reduction site, which results in a low Km and kcat values of Q2 reduction. The position of the methyl group in the tail is strictly recognized by the enzyme. In contrast to complex I, in bo-type ubiquinol oxidase, either of the two pi-electron systems in the tail is required for high-affinity binding of Q2H2 to the enzyme, while the presence of the methyl branch and the location of the pi-electron systems are not strictly recognized by the enzyme. We concluded that the role of the ubiquinone tail is not simply the enhancement of the hydrophobicity of the molecule and that molecular recognition of the tail by the quinone redox site differs among the respiratory enzymes.

[Endoscopical reconstruction of traumatic urethral disruption with ureteral resectoscope: a case report]

A 19-year-old man sustained a fracture of the left ischial rami and disruption of the membranous urethra when a car hit him against a wall. A suprapubic tube was placed and was used for reconstruction of the disrupted urethra 3 months later. Eighty days after the injury, an 11.5 F ureteral resectoscope was inserted through the open cystostomy tract. Simultaneously, a 11 F pediatric cystoscope was inserted via urethra. Using the "cut to the light" procedure, the scar tissue was incised with sharp strokes of the ureteral resectoscope revealing the distal urethral lumen. Sequentially, urethral dilatation to 24 F was performed over a 0.038 Teflon-coated guide wire following insertion of a 24 F urethral catheter. The urethral catheter was removed 22 days after the operation. Direct vision urethroscopy was performed at 1- to 2-week intervals for 3 months. At present 13 months after the operation, he performs 18 F urethral self-dilation and has been free of voiding complaints. The ureteral resectoscope is useful for endoscopical reconstruction of urethral disruption.

Essential structural factors of annonaceous acetogenins as potent inhibitors of mitochondrial complex I

The annonaceous acetogenins are the most potent of the known inhibitors of bovine heart mitochondrial complex I. These inhibitors act, at the terminal electron transfer step of the enzyme, in a similar way to the usual complex I inhibitors, such as piericidin A and rotenone; however, structural similarities are not apparent between the acetogenins and these known complex I inhibitors. A systematic set of isolated natural acetogenins was prepared and examined for their inhibitory actions with bovine heart mitochondrial complex I to identify the essential structural factors of these inhibitors for the exhibition of potent activity. Despite their very potent activity, the structural requirements of the acetogenins are not particularly rigid and remain somewhat ambiguous. The most common structural units, such as adjacent bis-tetrahydrofuran (THF) rings and hydroxyl groups in the 4- and/or 10-positions, were not essential for exhibiting potent activity. The stereochemistry surrounding the THF rings, surprisingly, seemed to be unimportant, which was corroborated by an exhaustive conformational space search analysis, indicating that the model compounds, with different stereochemical arrangements around the THF moieties, were in fairly good superimposition. Proper length and flexibility of the alkyl spacer moiety, which links the THF and the alpha, beta-unsaturated gamma-lactone ring moieties, were essential for the potent activity. This probably results from some sort of specific conformation of the spacer moiety which regulates the two ring moieties to locate into an optimal spatial position on the enzyme. It is, therefore, suggested that the structural specificity of the acetogenins, required for optimum inhibition, differs significantly from that of the common complex I inhibitors in which essential structural units are compactly arranged and conveniently defined. The structure-activity profile for complex I inhibition is discussed in comparison with those for other biological activities.

Specificity of pyridinium inhibitors of the ubiquinone reduction sites in mitochondrial complex I

Dual binding sites for pyridinium-type inhibitors in bovine heart mitochondrial complex I have been proposed (Gluck, M. R., Krueger, M. J., Ramsay, R. R., Sablin, S. O., Singer, T. P., and Nicklas, W. J. (1994) J. Biol. Chem. 269, 3167-3174). The marked biphasic nature of the dose-response curve for inhibition of the enzyme by MP-6(N-methyl-4-[2-(p-tert-butylbenzyl)propyl]pyridinium) makes this compound the first selective inhibitor of the two sites (Miyoshi, H., Inoue, M., Okamoto, S., Ohshima, M., Sakamoto, K., and Iwamura, H. (1997) J. Biol. Chem. 272, 16176-16183). Modifications of the structure of MP-6 show that a tert-butyl group on the benzene ring, a methyl group attached to the pyridine nitrogen atom, para-substitution pattern in the pyridine ring, and the presence of a branched structure in the spacer moiety are important for the selective inhibition. On the basis of the structural specificity, we synthesized a selective inhibitor, MP-24 (N-methyl-4-[2-methyl-2-(p-tert-butylbenzyl)propyl]pyridinium), which elicits greater selectivity. Characterization of the inhibitory behavior of MP-24 provided further strong evidence for the dual binding sites model.

Characterization of the ubiquinone reduction site of mitochondrial complex I using bulky synthetic ubiquinones

A wide variety of alkyl derivatives of Q2 (6-geranyl-2, 3-dimethoxy-5-methyl-1,4-benzoquinone) and DB (6-n-decyl-2, 3-dimethoxy-5-methyl-1,4-benzoquinone), in which methoxy groups of the 2- and/or 3-positions of the quinone ring were replaced by other bulky alkoxy groups from ethoxy to butoxy, were prepared by novel synthetic procedures. Electron-accepting activities of the bulky quinones were investigated with bovine heart mitochondrial complex I and its counterpart of Paracoccus denitrificans(NDH-1) to elucidate structural and functional features of the quinone reduction site of the enzymes. The bulky quinone analogues served as sufficient electron acceptors from the physiological quinone reduction site of bovine complex I. Considering the very poor activities of even the ethoxy derivatives as substrates for other respiratory enzymes such as mitochondrial complexes II and III [He, D. Y., Gu, L. Q., Yu, L., and Yu, C. A. (1994) Biochemistry 33, 880-884], this result indicated that the quinone reduction site of bovine complex I is spacious enough to accommodate bulky exogenous substrates. In contrast to bovine complex I, bulky quinone analogues served as poor electron acceptors with Paracoccus NDH-1. These observations indicated that bovine complex I recognizes the substrate structure with poor specificity. The substituent effects in the 2- and 3-positions of the quinone ring on the electron-transfer activity with bovine complex I differed significantly between Q2 and DB series despite having the same total number of carbon atoms in the side chain. The inhibitory effect involving Q2 due to its geranyl side chain was markedly diminished by structural modifications of the quinone ring moiety. These findings indicate that the side chain plays a specific role in the redox reaction and that the quinone ring and side-chain moieties contribute interdependently to binding interaction. Moreover, structural dependency of the proton-pumping activity of the quinone analogues was comparable to that of the electron-transfer activity with bovine complex I, indicating that the mechanism of redox-driven proton-pumping does not differ depending upon the substrate structure.