Population structure and landscape genetics of two endangered frog species of genus Odorrana: different scenarios on two islands.

Isolation by distance and landscape connectivity are fundamental factors underlying speciation and evolution. To understand how landscapes affect gene flow and shape population structures, island species provide intrinsic study objects. We investigated the effects of landscapes on the population structure of the endangered frog species, Odorrana ishikawae and O. splendida, which each inhabit an island in southwest Japan. This was done by examining population structure, gene flow and demographic history of each species by analyzing 12 microsatellite loci and exploring causal environmental factors through ecological niche modeling (ENM) and the cost-distance approach. Our results revealed that the limited gene flow and multiple-population structure in O. splendida and the single-population structure in O. ishikawae were maintained after divergence of the species through ancient vicariance between islands. We found that genetic distance correlated with geographic distance between populations of both species. Our landscape genetic analysis revealed that the connectivity of suitable habitats influences gene flow and leads to the formation of specific population structures. In particular, different degrees of topographical complexity between islands are the major determining factor for shaping contrasting population structures of two species. In conclusion, our results illustrate the diversification mechanism of organisms through the interaction with space and environment. Our results also present an ENM approach for identifying the key factors affecting demographic history and population structures of target species, especially endangered species.

Effect of age on bowel management in traumatic central cord syndrome.

STUDY DESIGN: A retrospective multicenter study. OBJECTIVES: To investigate the characteristics of bowel dysfunction in elderly people with traumatic central cord syndrome (TCCS). SETTING: A total of 28 Rosai hospitals in Japan. METHODS: The Rosai Hospital registry included 3006 persons with spinal cord injury during 1997-2007. The study subjects were 186 patients with TCCS (160 men, 26 women; mean age, 61.7±11.6 years, ±s.d.). Patients were divided according to age into the young group (<50 years, n=30), the middle-age group (50-69 years, n=112) and the elderly group (≥70 years, n=44). We assessed the differences in bowel management techniques (spontaneous, rectal medications and manual emptying) and activity of daily living (ADL) with respect to bowel care at discharge among the three groups. RESULTS: Continent spontaneous defecation was the most common bowel management method (50%, 93/186). The percentage of elderly subjects on continent spontaneous defecation (36.4%) was significantly less than that of the young group (66.7%; P<0.05). Furthermore, the percentage of elderly patients who required no bowel care (18.2%) was significantly less than those of the young (53.3%) and middle-age groups (41.1%; P<0.01). However, few differences in bowel care-related ADL were recognized among the three groups in patients who required manual emptying. CONCLUSION: The results identified significantly fewer patients aged ≥70 years with 'continent spontaneous defecation' or 'independent for bowel care' compared with younger patients. The results also highlighted the clinical importance of bowel dysfunction associated with TCCS especially in elderly people.

Incidence of symptomatic autonomic dysreflexia varies according to the bowel and bladder management techniques in patients with spinal cord injury.

STUDY DESIGN: A retrospective, multicenter study. OBJECTIVES: To investigate the relationship between bowel and bladder management methods and symptomatic autonomic dysreflexia (AD) during hospitalization in patients with spinal cord injury (SCI). SETTING: Twenty-eight Rosai hospitals in Japan. METHODS: The study subjects were 571 patients with SCI who had been admitted to 28 Rosai hospitals between April 1997 and March 2007 for rehabilitation therapy and fulfilled the following criteria: (1) SCI at or above sixth thoracic level, (2) discharged from hospital after more than 4 months of admission for initial injury and (3) lack of pressure ulcers, deep venous thrombosis, ureteral and renal stones or heterotopic ossification throughout hospitalization to exclude possible influence of these complications on cardiovascular reflexes. The study subjects were examined for the incidence of symptomatic AD according to age, sex, ASIA Impairment Scale, injury level, bowel and bladder management techniques at discharge. RESULTS: The Rosai Hospital registry included 3006 persons with SCI during 1997-2007, and 571 patients fulfilled the above criteria. The highest incidence of symptomatic AD was diagnosed in subjects using reflex voiding and in those using manual removal of stool. By contrast, the lowest incidence of symptomatic AD was in those on continent spontaneous voiding and continent spontaneous defecation. CONCLUSION: Medical staff should evaluate the presence of AD in patients with SCI at or above the T6 level under bladder and bowel management such as reflex voiding and manual removal of stool.

Conserved CDR 3 region of T cell receptor BV gene in lymphocytes from bronchoalveolar lavage fluid of patients with idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is an inflammatory lung disease characterized by the accumulation of inflammatory cells and deposition of collagen, resulting in lung remodelling. High numbers of T cells are present in bronchoalveolar lavage fluid (BALF) of IPF patients, although the characteristics of these cells are yet to be determined. To elucidate the pathogenic mechanisms of IPF, we analysed the T cell receptor (TCR) of BALF lymphocytes in three patients with IPF and three healthy subjects as control. TCR repertoire of BALF lymphocytes and T cell clonality were examined by family PCR and Southern blot analysis, and single-strand conformation polymorphism (SSCP), respectively. We observed that the TCR repertoire in the lung was heterogeneous, both in the control subjects and three patients with IPF. SSCP analysis demonstrated an increase in the number of accumulated T cell clones in BALF of two of the three patients, but not in the healthy subject. Furthermore, junctional sequence analysis showed the presence of conserved amino acid motifs (ETGRSG, LAxG, QGQ, GxQP, GRxG, VAR, PGT, GTI, GGT, TGR, LxLxQ, SGQ) in the TCR-CDR 3 region of BAL lymphocytes in patients with IPF, whereas only two amino acid motifs (VTTG, GGE) were found in the control. Our findings suggest that T cells in BALF of patients with IPF expand oligoclonally in the lung, suggesting antigen stimulation of these cells.

Airway epithelial cells promote transmigration of eosinophils in a new three-dimensional chemotaxis model.

BACKGROUND: Prominent infiltration of eosinophils in airway mucosa is the pathognomonic sign of asthma. The role of airway epithelial cells in eosinophil infiltration, however, has not been fully elucidated. OBJECTIVE: The aim of this study is to develop a new in vitro transmigration system composed of airway epithelial cells and extracellular matrix, and to investigate the role of airway epithelial cells in eosinophil infiltration. METHODS: A layer of type I collagen gel was formed in Netwell, and BEAS-2B bronchial epithelial cells were cultured on the gel. Then the wells covered with epithelial monolayer were filled with medium, inverted, and new upper chambers were constructed on the gel side by applying a ring cap. After further incubation with or without exogenous cytokines for 48 h, eosinophils or neutrophils were loaded in upper chambers (the gel side) and cells transmigrated to lower chambers (the epithelial cell side) were counted. Immunohistochemical analyses were also performed. RESULTS: While a simple collagen gel hardly promoted eosinophil migration even in the presence of eotaxin or RANTES, significant numbers of eosinophils migrated to lower chambers in the presence of the epithelial cells. Replacement of medium in the lower chamber (the epithelial cell side) with fresh medium, addition of exogenous eotaxin or RANTES in the upper chamber (the gel side), or pre-treatment of eosinophils with anti-CCR3 all inhibited transmigration. We found that the epithelial cells produced and deposited extracellular matrix proteins such as type IV collagen onto the type I collagen gel. Separately, we found that type IV collagen itself was capable of enhancing eotaxin-induced eosinophil migration in a standard chemotaxis assay. Neutrophils also efficiently migrated in the present transmigration system. Pre-treatment of epithelial cells with TNF-alpha and IL-4 enhanced eosinophil transmigration, while that of neutrophils was enhanced by TNF-alpha but suppressed by IL-4. CONCLUSION: By utilizing a new in vitro transmigration system mimicking the airway mucosa, we have demonstrated that airway epithelial cells play an essential role in transmigration of eosinophils and that multiple factors such as chemokines, extracellular matrix proteins and exogenous inflammatory cytokines are involved in efficient transmigration.

Thickening of sphenoid sinus mucosa during the acute stage of pituitary apoplexy.

The authors treated two patients with pituitary apoplexy in whom magnetic resonance (MR) images were obtained before and after the episode. Two days after the apoplectic episodes, MR imaging demonstrated marked thickening of the mucosa of the sphenoid sinus that was absent in the previous studies. The relevance of this change in the sphenoid sinus was investigated. Retrospective evaluations were performed using MR images obtained in 14 consecutive patients with classic pituitary apoplexy characterized by acute onset of severe headache. The mucosa of the sphenoid sinus had thickened predominantly in the compartment just beneath the sella turcica, in nine of 11 patients, as ascertained on MR images obtained within 7 days after the onset of apoplectic symptoms. This condition improved spontaneously in all four patients who did not undergo transsphenoidal surgery. The sphenoid sinus mucosa appeared to be normal on MR images obtained from three patients at the chronic stage (> 3 months after onset). The incidence of sphenoid sinus mucosal thickening during the acute stage was significantly higher in the patients with apoplexy than that in the 100 patients without apoplexy. A histological study conducted in four patients who underwent transsphenoidal surgery during the early stage showed that the subepithelial layer of the sphenoid sinus mucous membrane was obviously swollen. The sphenoid sinus mucosa thickens during the acute stage of pituitary apoplexy. This thickening neither indicates infectious sinusitis nor rules out the choice of the transsphenoidal route for surgery.

Concomitant pituitary adenoma and Rathke's cleft cyst.

We reviewed the clinical, radiological and surgical findings in patients with both pituitary adenoma and Rathke's cleft cyst. We retrospectively selected patients with both lesions from the 374 patients in whom a sellar/juxtasellar lesion was detected on MRI at 1.5 tesla. All patients received intravenous contrast medium. Concomitant pituitary adenoma and Rathke's cleft cyst were found in eight patients (2.1 %). The frequency of the combination was 3.5 % of pituitary adenomas and 11% of Rathke's cleft cysts. Symptoms were always due to the adenoma, secreting adrenocorticotrophin in two patients and growth hormone in six. The adenoma was larger in five patients, and the cyst in three. The cysts gave variable signal. The adenoma was adjacent to the cyst in seven patients, and enclosed it in the other patient. As a result of experience with MRI, concomitant pituitary adenoma and Rathke's cleft cyst are now known not to be as rare as thought previously. When a non-enhancing cyst-like structure is demonstrated in a patient with pituitary adenoma, the possibility of a coexisting Rathke's cleft cyst should be considered.

[Decompressive craniectomy for massive infarction of middle cerebral artery territory].

There is continuing controversy about the benefits of decompressive craniectomy for the treatment of massive infarction of middle cerebral artery (MCA) territory. Under conservative therapy, the mortality rate for this stroke is reported to be up to 80%. So the authors have actively carried out decompressive craniectomy since 1997, and have compared the outcome with patients who were admitted before 1997 and, consequently treated with conservative therapy. Fifteen consecutive victims of massive infarction of MCA territory were studied. Seven patients (male: 1, female: 6, mean age: 79.8 years) were treated with conservative therapy, and 8 patients (male: 3, female: 5, mean age: 71.8 years) were treated with decompressive craniectomy. There were no significant differences in age and consciousness level distribution between the two groups. Mortality rate in the conservative therapy group was 85.7% against 12.5% in the surgery group (p < 0.05). Functional performance, which was evaluated by activity in daily life (ADL), was also better in the surgery group e.g. 3 patients in ADL 3, and 3 in ADL 4 (1 patient died from a non-neurological cause). Even among the patients with speech-dominant hemispheric stroke, all except one were able to communicate in some way and understand language. Even though patients in this study were elderly, decompressive craniectomy reduced mortality and improved functional performance, so it seems that this surgery should be aggressively considered for massive infarction of MCA territory.

Analysis of T cell receptor V(beta) gene expression and clonality in bronchoalveolar fluid lymphocytes from a patient with chronic eosinophilic pneumonitis.

Chronic eosinophilic pneumonitis (CEP) is characterized by longstanding respiratory symptoms accompanied by a massive pulmonary eosinophil infiltration. T lymphocytes in bronchoalveolar lavage (BAL) from patients with chronic eosinophilic pneumonitis are considered to recognize unknown antigens. To analyze the pathogenesis of CEP, we examined the T cell receptor (TCR) repertoire and T cell clonotype of BAL lymphocytes and peripheral blood lymphocytes (PBLs) in a 66-year-old woman patient with CEP. The expression of TCR BV gene was analyzed by the family PCR method using specific primers for 20 TCR BV genes and BC gene. The clonotype of BAL and peripheral T cells was examined by the PCR-single-strand conformation polymorphism (SSCP) method. Functional sequences of some T cell clones were also carried out. A TCR repertoire of BAL T cells was heterogeneous as well as PBLs. However, SSCP analysis showed that distinct T cell clonotypes were detected in BAL T cells, TCR BV3, BV4, BV6, BV8, BV9, BV14, and BV18-positive T cell clones especially, expanded clonally in BAL from the patient. Sequencing analysis showed that GVD, LGG, RDXS, and SSG amino acid sequence motif were found in the CDR3 in lung-specific T cells. BAL-specific T cell clones accumulated in the patient with CEP. Thus, we can conclude that BAL T cells are induced by the antigen-driven stimulation and these cells might play a crucial role in the generation of CEP.

[Long distance air transport by helicopter of a patient with severe head damage].

A report of a case of a patient with severe head trauma with pneumonia and cerebral infarction transported by helicopter. An eighty-year-old male was referred to our hospital because of dyspnea after a fall during sightseeing at Hiroshima. He was lucid at first, but, after two days presented restlessness due to brain contusional hemorrhage and edema. Moreover, he developed pneumonia and cerebral infarction during the period of his hospitalization. He was intubated and received central venous routing. While being transported, his consciousness showed moderate disturbance, aphasia and right hemiplegia. His family asked that therapy be continued near his house in Osaka. We selected transport by helicopter because of his bad general condition and because transport time would be much shorter. He was transported by helicopter to Osaka one month after admission. First, he was transported by ambulance to the airport of Hiroshima. He was carried to the helicopter at the airport. An oxygen cylinder was connected to the incubation tube via an ambu bag because direct connection between the oxygen cylinder and the intubation tube was impossible. Just before the take off, O2 saturation was checked by the pulse oximeter of the ambulance. In the helicopter, there were six men; two pilots, two rescue men, one doctor and the patient. Suction was applied only once and there was no trouble during the flight. The weather was fine and the helicopter experienced almost no rolling during the flight. The flight time was only one hour and twenty minutes. The helicopter safely landed at an emergency heliport in Osaka. The patient was carried to a waiting ambulance and transported to the hospital. Total transport time was only two hours and thirty minutes. This is a case showing a helicopter could safely transport a patient with severe brain damage over a long distance in a short time.

Early rehabilitation effect for traumatic spinal cord injury.

OBJECTIVE: To determine the natural course of traumatic spinal cord injury (SCI) and the effect of early rehabilitation on it. DESIGN: A retrospective, multicenter study. SETTING: Sixteen Rosai hospitals and 1 medical school. PARTICIPANTS: One hundred twenty-three SCI patients (104 men, 19 women; mean age, 48.8 +/- 17.7yr) enrolled. INTERVENTIONS: Dividing the subjects into an early rehabilitation group and a delayed group; differences were ensured by international classification of SCI. MAIN OUTCOME MEASURES: Using the American Spinal Injury Association (ASIA) classifications, the motor recovery rate (MRR) was defined as (ASIA motor score at discharge - ASIA motor score at admission)/(100 - ASIA motor score at admission). The regression lines for FIM instrument score and ASIA motor score were determined for 6 subgroups (early or delayed tetraplegia, central cord injury, paraplegia) by the MRR staging. The regression lines for physical or cognitive FIM score and ASIA motor score were also determined for 6 subgroups. RESULTS: Three stages were obtained: acute stage: 2 weeks postinjury; recovery stage: 2 weeks to 6 months postinjury; and chronic stage: more than 6 months postinjury. Regression lines showed that rehabilitation improved physical functional independence for ASIA motor score, especially in the early rehabilitation subgroups. There was no correlation between cognitive FIM score and ASIA motor score in 6 subgroups. CONCLUSION: Early SCI rehabilitation contributes to good physical activities of daily living for motor function.

Complete nucleotide sequence and gene rearrangement of the mitochondrial genome of the Japanese pond frog Rana nigromaculata.

In this study, we determined the complete nucleotide sequence of the mitochondrial genome of the Japanese pond frog Rana nigromaculata. The length of the sequence of the frog was 17,804 bp, though this was not absolute due to length variation caused by differing numbers of repetitive units in the control regions of individual frogs. The gene content, base composition, and codon usage of the Japanese pond frog conformed to those of typical vertebrate patterns. However, the comparison of gene organization between three amphibian species (Rana, Xenopus and caecilian) provided evidence that the gene arrangement of Rana differs by four tRNA gene positions from that of Xenopus or caecilian, a common gene arrangement in vertebrates. These gene rearrangements are presumed to have occurred by the tandem duplication of a gene region followed by multiple deletions of redundant genes. It is probable that the rearrangements start and end at tRNA genes involved in the initial production of a tandemly duplicated gene region. Putative secondary structures for the 22 tRNAs and the origin of the L-strand replication (OL) are described. Evolutionary relationships were estimated from the concatenated sequences of the 12 proteins encoded in the H-strand of mtDNA among 37 vertebrate species. A quartet-puzzling tree showed that three amphibian species form a monophyletic clade and that the caecilian is a sister group of the monophyletic Anura.

Biochemical and morphological changes in herniated human intervertebral disc.

The molecular and morphologic features of herniated human intervertebral disc tissues are of particular importance to clarify the pathogenesis. The present study analyzed the biochemical and morphological features of herniated intervertebral disc tissues to determine the constituent factors responsible for intervertebral disc herniation. A total of 32 herniated disc specimens and 4 control disc samples were analyzed. Collagen subunit composition, collagenase activity, lipid peroxidation level, caspase-3 activity, metal levels, morphologic studies, and genetic analysis were performed on herniated disc tissues of chronic (group A) and acute (group B) group and compared with findings of control group. Nick translation analysis in situ revealed apoptotic-positive stained DNA fragments as black-brown spots in herniated disc tissues. The presence of type II collagen in control disc samples and its absence in herniated samples were confirmed immunohistochemically. The increased caspase-3 activity, the apoptotic-positive stained DNA fragments, and the electron microscopic findings suggest enhanced programmed cell death in herniated discs. The significant increase in lipid peroxidation levels and collagenase activity, and the low metal levels suggest the enhancement of cell death signals in herniated discs, caused by oxygen stress. Linkage analysis of herniated disc tissues in Japanese individuals may suggest ethnic variation. These findings may be helpful in understanding the pathogenesis of herniated disc disease.

Improvement of capillary zone electrophoresis sensitivity with artificial seawater as the background electrolyte utilizing transient isotachophoresis for the determination of nitrate and nitrate ions in seawater.

We describe capillary zone electrophoresis (CZE) with transient isotachophoresis (ITP) for the determination of low concentrations of nitrite and nitrate ions in seawater. Bromide-free artificial seawater was adopted as background electrolyte (BGE) to eliminate the interference of high concentrations of salts in seawater. To reverse the electroosmotic flow (EOF), 3 mM cetyltrimethylammonium chloride (CTAC) was added to the BGE. High concentrations of chlorate were added to sample solutions as the terminating ion to generate the ITP process before the CZE separation. In general, the stacking effect increased with increasing amounts of chlorate injected into the capillary. The limits of detection (LODs) for nitrite and nitrate were 0.063 and 0.033 mg/L when the chlorate concentration was 600 and 200 mM, respectively; these were half of those obtained by CZE without the transient ITP. The LODs were obtained at a signal to noise ratio (S/N) of 3. The relative standard deviations (RSD, n = 10) of the peak areas for these ions were 3.2 and 2.9%. The RSDs of peak heights for these ions were 1.6 and 2.1%. The RSDs of migration times for these ions were 0.67 and 0.46%.

Molecular phylogenetic relationships of pond frogs distributed in the Palearctic region inferred from DNA sequences of mitochondrial 12S ribosomal RNA and cytochrome b genes.

The evolutionary relationships of pond frogs distributed in the Far East and Europe were investigated by analyses of nucleotide sequences of mitochondrial 12S ribosomal RNA (12S rRNA) and cytochrome b (cyt b) genes. The nucleotide sequences of a 412-bp segment of the 12S rRNA gene and a 534-bp segment of the cyt b gene were determined by the PCR-direct sequencing method using 19 frogs belonging to six species and one subspecies distributed in the Palearctic region. Phylogenetic trees were constructed by the neighbor-joining and maximum-likelihood methods using Rana catesbeiana or Xenopus laevis as an outgroup. The 412-bp segment of the 12S rRNA gene contained 65 variable sites including gap sites, and the 534-bp segment of the cyt b gene contained 160 variable sites. The nucleotide sequence divergences of the 12S rRNA gene were 0.25-4.83% within the Far Eastern frogs, 0.25-6.22% within the European frogs, and 8.74-11.24% between the Far Eastern and the European frogs, whereas those of the cyt b gene were 3.64-14.73% within the Far Eastern frogs, 0.38-14.42% within the European frogs, and 16.53-23.58% between the Far Eastern and the European frogs. Although most nucleotide substitutions were at the third codon position of the cyt b gene and were silent mutations, 4 amino acid replacements occurred within the Far Eastern frogs, 4 within the European frogs, and 11 between the Far Eastern and the European frogs. The phylogenetic trees constructed from the nucleotide sequence divergences showed slightly different topologies for the 12S rRNA and cyt b genes. R. esculenta from Ukraine was closely related to R. lessonae from Luxembourg in both the 12S rRNA and the cyt b gene sequences.

Substrate-dependent lipolysis induced by isoproterenol.

The relationship between isoproterenol-induced lipolysis and the phosphorylation of perilipin and hormone-sensitive lipase (HSL) was examined using cell-free systems consisting of lipid droplets isolated from rat fat cells and HSL, and/or trioleoylglycerol emulsified with gum arabic and HSL. Isoproterenol was found to stimulate lipolysis in the cell-free system with the lipid droplets without an increase in the phosphorylation of either perilipin or HSL. On the other hand, no stimulation of lipolysis was found in the cell-free system containing lipid droplets despite increases in the phosphorylation of perilipin and HSL. In the cell-free system consisting of trioleoylglycerol emulsified with gum arabic and HSL, neither isoproterenol nor increases in the phosphorylation of perilipin and HSL accelerated lipolysis. These results suggest that isoproterenol-induced lipolysis may not be mediated through the phosphorylation of perilipin and HSL, and may rather be dependent on the substrate of HSL.

The steady-state kinetics of the enzyme reaction tested by site-directed mutagenesis of hydrophobic residues (Val, Leu, and Cys) in the C-terminal alpha-helix of human adenylate kinase.

To elucidate whether the C-terminal region in human adenylate kinase participates in the interaction with the substrate (MgATP(2-) and/or AMP(2-)), hydrophobic residues (Val182, Val186, Cys187, Leu190, and Leu193) were substituted by site-directed mutagenesis and the steady-state kinetics of fifteen mutants were analyzed. A change in the hydrophobic residues in the C-terminal domain affects the affinity for substrates (K(m)), that is, not only for MgATP(2-) but also for AMP(2-), and the catalytic efficiency (k(cat)). The results obtained have led to the following conclusions: (i) Val182 may interact with both MgATP(2-) and AMP(2-) substrates, but to a greater extent with MgATP(2-), and play a role in catalysis. (ii) Val186 appears to play a functional role in catalysis by interacting with both MgATP(2-) and AMP(2-) to nearly the same extent. (iii) Cys187 appears to play a functional role in catalysis. (iv) Leu190 appears to interact with both MgATP(2-) and AMP(2-) substrates but to a greater extent with AMP(2-). (v) Leu193 appears to interact with both MgATP(2-) and AMP(2-) but to a greater extent with AMP(2-). The activity of all mutants decreased due to the change in substrate-affinity. The closer the residue is located to the C-terminal end, the more its mutation affects not only MgATP(2-) but also AMP(2-) substrate binding. The hydrophobic alterations disrupt hydrophobic interactions with substrates and that might destabilize the conformation of the active site. The more C-terminal part of the alpha-helix appears to interact with AMP, as if it has swung out and rotated to cover the adenine moieties. The C-terminal alpha-helix of human adenylate kinase appears to be essential for the interaction with adenine substrates by swinging out during catalysis.

Substituted 3-phenylsulfonylquinazoline-2,4-dione derivatives as novel nonpeptide inhibitors of human heart chymase.

A series of 3-phenylsulfonylquinazoline-2,4-dione derivatives have been synthesized and evaluated for their ability to inhibit human heart chymase. The structure-activity relationship studies on these compounds gave the following results. The phenyl moiety of quinazoline participates in a hydrophobic interaction where an optimum size is required. In this moiety, 7-chloroquinazoline is the best moiety for inhibiting chymase, chymotrypsin and cathepsin G. A 3-phenylsulfonyl moiety substituted with hydrophobic electron-withdrawing groups at the 4-position potentiated the activity. Anthranil moiety also enhanced the activity. Pyridylmethyl and N-pyridylacetamide at the 1-position gave an IC50 in the order of 10(-8)M. Molecular modeling studies on the interaction of 7-chloro-3-(4-chlorophenylsulfonyl) quinazoline-2,4(1H, 3H)-dione (4) with the active site of human heart chymase suggested that the phenyl moiety of quinazoline interacts with the hydrophobic P1 pocket, the 3-phenylsulfonyl moiety resides in the S1'-S2' subsites, the moiety at the 1-position locates in the S2-S3 subsites and the 4-carbonyl and 3-sulfonyl group interact with the oxyanion hole and the His57 side-chain of chymase, respectively.

Sequence variation and structural conservation in the D-loop region and flanking genes of mitochondrial DNA from Japanese pond frogs.

The nucleotide sequences of the D-loop region and its flanking genes of the mitochondrial DNA (mtDNA) from Japanese pond frogs were determined by the methods of PCR, cloning, and sequencing. The frogs belonged to two species, one subspecies, and one local race. The gene arrangements adjacent to the D-loop region were analyzed. The frogs shared a unique mitochondrial gene order that was found in Rana catesbeiana; i.e., cyt b--D-loop region--tRNA(Leu(CUN))--tRNA(Thr)--tRNA(Pro)--tRNA(Phe)--12S rRNA. The arrangements of the three tRNA genes of these frogs were different from those of X. laevis, a species which has the same overall structure as in mammals. Highly repetitive sequences with repeat units (16-bp or 17-bp sequence specific for each taxon) were found in the D-loop region. The length of repetitive sequences varied from 0.6 kbp to 1.2 kbp, and caused the extensive size variation in mtDNA. Several short sequence elements such as putative TAS, OH, CSB-1, and CSB-2 were found in the D-loop region of these frogs. The sequences of these short regulatory elements were conserved in R. catesbeiana, X. laevis, and also in human. The comparison of sequence divergences of the D-loop region and its adjacent genes among various taxa revealed that the rates of nucleotide substitutions depend on genes. The nucleotide sequences of the 3'-side segment of the D-loop region were the most variable among taxa, whereas those of the tRNA and 12S rRNA genes were the most conservative.