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Biomedical subjects

H Ueno

Publications and source records attributed to H Ueno.

At least 73 records · Page 4Linked to original sources
PubMed2001

Comparison of genetic variation in growth performance on normal and novel host plants in a local population of a herbivorous ladybird beetle, Epilachna vigintioctomaculata.

Local populations of herbivore species that display variation in host plant use are subject to natural selection for improved ability to use their own host species. Since natural selection changes the frequency of alleles that control host use, genetic variation in growth performance on host plants may change with each generation of selection. Therefore, within-population variations in the ability to use different hosts may reflect past selective forces. The present study reports the genetic variation in growth performance in a population of the herbivorous ladybird beetle, Epilachna vigintioctomaculata Motschulsky (Coccinellidae, Epilachninae) on both the normal host and a novel host. The present study found higher heritabilities for growth performance on the novel host than the normal host. The difference in heritabilities was caused by smaller among-family variance components on the normal host compared to those on the novel host. The results are compatible with the view that natural selection, which improved the ability of the population to use a particular host plant, has reduced genetic variation within that population in the ability to use that host plant. The pattern of reduced genetic variation in a population reared on the normal host observed in the present study is compared with that in another population, which showed local adaptation in the use of its own host plant. The effect of natural selection on differing host plant use on within-population genetic variation is discussed.

Adaptation, Physiological↗
PubMed2001

Treatment strategy for small hepatocellular carcinoma: comparison of long-term results after percutaneous ethanol injection therapy and surgical resection.

This comparative study was conducted to clarify the efficacy of percutaneous ethanol injection (PEI) and surgical resection in the treatment of small hepatocellular carcinomas (HCC). Thirty-nine patients treated by PEI and 58 who underwent hepatic resection for small HCC (smaller than 3 cm and 3 or less in number) during the same period were enrolled. The surgery group included more patients with large and multiple bilobar nodules than the PEI group. The histological differentiation of the treated tumors became worse in the surgery patients than in those treated by PEI. On the other hand, the PEI group included more patients with a poor hepatic reserve, according to Child-Pugh grading, the ICG test, and the serum total bilirubin value. The 1-, 3-, and 5-year overall survival rates were almost identical between the 2 cohorts (100%, 82.1%, and 59.0%, respectively, in the PEI group; 96.6%, 84.4%, and 61.5%, respectively, in the surgery group) (P =.96). During the follow-up period, 33 of 39 (85%) and 41 of 58 (71%) patients developed tumor recurrence after PEI and surgery, respectively. Cumulative 1-, 3-, and 5-year tumor-free survival rates in the PEI group were 63.4%, 30.3%, and 9.7 %, whereas those in the surgery group were 75.5%, 44.7%, and 25.7%, respectively (P =.10). Our overall findings show that local therapy can achieve an actual 5-year survival rate of around 60% for patients with small HCC with the proper selection of treatment. A prospective randomized comparative trial is required to settle this longstanding issue.

Adult↗
PubMed2001

Recognition and specific degradation of bacteriophage T4 mRNAs.

Gene 61.5 of bacteriophage T4 has a unique role in gene expression. When this gene is mutated, mRNAs of many late genes are rapidly degraded, resulting in late-gene silencing. Here, we characterize an extragenic suppressor, ssf5, of a gene 61.5 mutation. ssf5 was found to be an amber mutation in motA, which encodes a transcription activator for T4 middle genes. When this gene is mutated, both degradation and specific cleavage of late-gene mRNA is induced after a delay, as exemplified by soc mRNA. Consequently, partial late-gene expression occurs. In an ssf5 genetic background, a gene 61.5 mutation exhibits a novel phenotype: in contrast to late-gene mRNA, middle-gene mRNA is stabilized and the expression of middle genes is prolonged. This is attributable to an activity of gene 61.5 specific for degradation of middle-gene mRNA. The degradation of middle-gene mRNA in the presence of a normal gene 61.5 appears in parallel with the degradation of late-gene mRNA in its absence. This observation suggests that the mRNA-degrading activity that silences late genes in cells infected with a gene 61.5 mutant is targeted to middle-gene mRNA when gene 61.5 is wild type. These results and the results obtained in the presence of a normal motA gene suggest that gene 61.5 protein functions to discriminate mRNAs for degradation in a stage-dependent manner.

Bacteriophage T4↗
PubMed2001

Phase I trial of gemcitabine in patients with advanced pancreatic cancer.

BACKGROUND: Gemcitabine is the most promising new agent currently being tested in pancreatic cancer. The present study was conducted to confirm the tolerability of a weekly schedule of gemcitabine at a dose of 1000 mg/m2 in Japanese patients with advanced pancreatic cancer. METHODS: The primary end-point was to evaluate the frequency of dose-limiting toxicity. Gemcitabine 1000 mg/m2 was administered over 30 min weekly in two schedules: gemcitabine x3 every 4 weeks (Schedule 1) and gemcitabine x7 followed by a week of rest and then gemcitabine x3 every 4 weeks thereafter (Schedule 2). At least three patients entered each schedule and three additional patients were treated in the presence of dose-limiting toxicity. RESULTS: Eleven chemo-naive patients with a good Karnofsky performance status of > or =80 points and distant metastasis were entered into this trial. In Schedule 1, no dose-limiting toxicity was observed in the three patients. In Schedule 2, the evaluation of dose-limiting toxicity was complete in six of the eight enrolled patients and two patients showed dose-limiting toxicity in this Schedule; one patient experienced both grade 4 leukocytopenia and grade 4 neutropenia, and both grade 4 neutropenia and grade 3 GOT/GPT increased in another patient. Two patients (18%) showed a partial response and a clinical benefit response was also achieved in two (29%) of the seven evaluable patients. CONCLUSION: Gemcitabine 1000 mg/m2 weekly x7 followed by a week of rest and weekly x3 every 4 weeks thereafter may be tolerated in Japanese patients with advanced pancreatic cancer.

Adult↗
PubMed2001

Radiofrequency ablation and percutaneous ethanol injection in patients with small hepatocellular carcinoma: a comparative study.

BACKGROUND: Radiofrequency ablation (RFA) is a novel thermal ablation technique to achieve coagulative necrosis of hepatocellular carcinoma. A study was conducted to compare the antitumor effect and adverse effect of RFA with those of percutaneous ethanol injection (PEI) in patients with solitary small hepatocellular carcinoma. METHODS: The study population consisted of 119 consecutive patients with solitary hepatocellular carcinoma smaller than 3 cm in diameter. Among these, 23 patients were treated with RFA and the remaining 96 patients were treated with PEI. The antitumor effects of both treatments were assessed by contrast-enhanced computed tomography 1 month after treatment. RESULTS: Complete tumor necrosis was achieved in 23 patients (100%) of the RFA group and 90 patients (94%) of the PEI group (p = 0.48) and local recurrence rates at 1 year were 15% in the RFA group and 14% in the PEI group (p = 0.80). RFA required an average of 1.5 sessions to achieve complete necrosis, whereas PEI required an average of 4.0 sessions. As a consequence, the hospital stay in the RFA group (median 10 days) was significantly shorter than that in the PEI group (median 17 days). There were no serious adverse effects or complications except for one case of cholangitis in the PEI group, although deterioration of serum transaminase after RFA was significantly more severe than that after PEI. CONCLUSION: RFA achieved complete tumor necrosis for small hepatocellular carcinoma with fewer treatment sessions compared with PEI. There were no serious complications.

Adult↗
PubMed2001

Spontaneous regression of hepatocellular carcinoma with multiple lung metastases: a case report.

Spontaneous regression of hepatocellular carcinoma is an extraordinarily unusual phenomenon. We present here a case of a 75-year-old man in whom multiple lung metastases of hepatocellular carcinoma regressed spontaneously. He underwent systemic chemotherapy for hepatocellular carcinoma with multiple lung metastases. However, the chemotherapy was not effective and he was therefore followed up without any anticancer treatments in an outpatient clinic. Four months later, multiple lung nodules regressed dramatically and the serum alpha-fetoprotein level decreased markedly. After an 8-month period of the regression, however, intrahepatic lesions gradually enlarged, although multiple lung metastatic lesions remained regressed. The mechanisms underlying this intriguing phenomenon remain unknown.

Aged↗
PubMed2001

Structural and functional changes in bovine pancreatic ribonuclease a by the replacement of Phe120 with other hydrophobic residues.

To clarify the specific role of Phe120 in bovine pancreatic ribonuclease A (RNase A), changes in the thermal stability and activity of F120L, F120A, F120G, and F120W were analyzed with respect to some thermodynamic terms, i.e., Gibbs free energy, enthalpy, and entropy. The structural destabilization of F120L, F120A, and F120G was due to a decrease in DeltaH(m) with a parallel decrease in amino-acid volume at position 120, while the destabilization of F120W can be ascribed to an increase in DeltaS(m) accompanying an increase in DeltaH(m), showing that the size of Phe120 produces an optimum balance of conformational enthalpy and entropy for achieving the maximal structural stability. Moreover, the replacement of Phe120 affects activity. The increase in K(m) showed that the hydrophobicity and pi electron of Phe120 are important factors in substrate binding. The decrease in k(cat) was predicted to be due to positional changes of the side chains of His12 and/or His119. The positional changes were successfully detected by the rate of carboxymethylation by iodoacetate or bromoacetate, which correlated very well with decreases in activity, supporting the view that Phe120 also plays an important role in determining the position of His12 and/or His119 in order to achieve efficient catalysis.

Acetates↗
PubMed2001

Prognostic determinants of patients with lateral nodal involvement by rectal cancer.

OBJECTIVE: To clarify the characteristics related to long-term survival in patients with lateral nodal involvement. SUMMARY BACKGROUND DATA: Few reports have addressed the prognostic determinants in patients with actual lateral nodal involvement, which are important in determining treatment. METHODS: Review of a prospective colorectal database at a single institution for a 10-year period (1987-1996) identified 53 patients with lateral nodal involvement. RESULTS: All nine patients who underwent resection of synchronous distant metastases developed recurrence and died within 3 years. Of the 44 patients without distant metastases, 25 (57%) developed locoregional recurrence, and the overall 5-year survival rate was 32%. Multivariate analysis showed that age, total number of involved nodes (mesorectal and lateral), and circumferential surgical margin involvement had independently predicted postoperative survival. Patients with three or fewer nodes involved accounted for one third of lateral-positive patients, with a 5-year survival rate of 75%, whereas the 18 patients with four or more involved nodes had a 5-year survival rate of 4%. All eight patients with circumferential margin involvement died of carcinoma, and seven developed locoregional recurrences. Involvement of other pelvic organs had no effect on prognosis, nor were adverse prognostic outcomes noted by the region of lateral involvement. CONCLUSIONS: For patients with lateral involvement, the most important prognostic variables are distant metastases, the total number of nodes involved, circumferential margin involvement, and age. Selection of patients based on these variables may lead to the identification of a subgroup for whom lateral nodal dissection could be the first treatment choice.

Adult↗
PubMed2001

Abdominal pain in patients with resectable pancreatic cancer with reference to clinicopathologic findings.

Abdominal and/or back pain is one of the most common symptoms in patients with pancreatic cancer. However, the cause of the pain and the clinicopathologic features of patients with pain have not been fully elucidated. We retrospectively determined the factors related to preoperative abdominal and/or back pain in 95 patients with resectable pancreatic cancer. Pancreatic tumor size, invasion of the intrapancreatic nerves, invasion of the anterior pancreatic capsule, and lymph node metastasis were determined to be variables related to the pain. Pancreatic tumor size, invasion of anterior pancreatic capsule, and lymph node metastasis were also variables significantly correlating to pain intensity. Survival also correlated with pain intensity: the median survival periods were 29 months in patients without pain, 19 months in those with mild pain, and 9 months in those with severe pain who required analgesics. Larger pancreatic tumors, invasion of the intrapancreatic nerves, and invasion of the anterior pancreatic capsule may cause abdominal and/or back pain in patients with resectable pancreatic cancer. This study also suggests clinical implications of the pain intensity as a prognostic factor in patients with resectable pancreatic cancer.

Abdominal Pain↗
PubMed2001

Seroprevalence of antibodies against spotted fever group rickettsia among dogs and humans in Okinawa, Japan.

We evaluated serum antibodies against Rickettsia japonica in 517 dogs (430 stray dogs and 87 pet dogs) and 164 humans in Okinawa, Japan, by indirect immunofluorescence assay. The seropositive rate in stray dogs was significantly higher than that in pet dogs (30.7 versus 4.6%, P<0.01). This high prevalence rate is attributed to the understandably frequent environmental exposure of stray dogs to tick infestation. Human samples obtained from Okinawa and Sapporo also showed a significant difference in seropositive antibody percentages (45.1 and 12.0%, respectively, P<0.01). This result suggests that there has been pre-exposure to spotted fever group rickettsia in humans in Okinawa.

Animals↗
PubMed2001

First detection of Ehrlichia platys in dogs and ticks in Okinawa, Japan.

We investigated Ehrlichia platys infection of dogs and ticks in Okinawa, Japan. Using E. platys specific primers, E. platys and HE3-R, PCR-positive results were obtained with 32.0% (64/200) of blood samples of dogs and 3.8% (3/77) of ticks. The nucleotide sequences of the amplified DNA fragment from the dogs and the ticks infesting them were identical, and the sequence corresponded to that of the E. platys Gzh981 strain. We concluded that there is a cyclic maintenance of E. platys between dogs and ticks in Okinawa.

Animals↗
PubMed2001

Mechanism for maintenance of dominant T helper 1 immune responses in Lewis rats.

Lewis rats are prone to T helper (Th) 1 immune responses, whereas Brown Norway (BN) rats are susceptible to Th2 immune responses. Yet, the precise mechanism of induction of the different outcome between these two strains remained elusive. We investigated the expression levels of some cytokines, their receptors and accessory molecules responsible for the polarization of antigen-specific immune response into a predominant Th1 or Th2 profile in Lewis and BN rats. Lymph node (LN) cells collected from rats immunized with short ragweed (RW) were used directly or after stimulation in vitro with RW for 3 days. Expression of cytokines, their receptors and accessory molecules in these LN cells were tested by reverse transcriptase-PCR. Culture supernatant was used for ELISA to detect IL-12 protein. We observed clear differences between these strains in the expression of IL-12p40, which was high in LN cells of Lewis rats even before stimulation in vitro. In addition, a higher amount of IL-12 was present in the culture supernatant in Lewis rats. Upregulation of the expression of IL-12 receptor beta1, beta2, IFN-gamma receptor alpha and beta genes were more prominent in Lewis rats rather than BN rats. Furthermore, attenuated expression of CD40 and CD40 ligand by stimulation in vitro was noted only in BN rats. Changes in expression of these molecules by stimulation as well as higher basal level of IL-12p40 might have led to the activation of Th1 cells in Lewis rats.

Animals↗
PubMed2001

UR-3216: a manageable oral GPIIb/IIIa antagonist.

UR-3216, a prodrug, is a novel, selective, and orally active platelet surface glycoprotein (GPIIb/IIIa) receptor antagonist. The most important property of UR-3216 is the very tight binding of its active metabolite to platelets (Ki for resting platelets is < 1 nM). UR-2992, the active form of UR-3216, binds to platelets for a long period of time, while the unbound drug is rapidly cleared. Therefore, after an initial loading dose of 0.1 mg/kg, only once daily repeated low maintenance doses of UR-3216 (< 0.05 mg/kg p.o.) are required. This regimen maintains a high level of inhibition of platelet aggregation and, due to a small peak-to-trough ratio, severe bleeding is avoided. The therapy with UR-3216 is easy to manage, because it has low peak-to-trough ratio and high efficacy (> 80% inhibition of platelet aggregation). In addition, UR-3216 does not produce excessive bleeding or thrombocytopenia and does not interact with abciximab. UR-3216 is excreted mostly in bile, so that it will not accumulate in patients with chronic renal dysfunction. UR-2316 has the following abciximab-like features: (a) its half-lives for residence on platelets, inhibition of platelets aggregation and bleeding time prolongation are 60 to 80 h, 24, and 2 h, respectively; (b) its receptor binding occupancy is similar to that of abciximab (Mab1 is inhibited and Mab2 is unaltered). In conclusion, UR-3216 is a promising, orally active GPIIb/IIIa antagonist for the treatment of cardiovascular diseases.

Administration, Oral↗
PubMed2001

Effects of in vivo gene transfer of fibroblast growth factor-2 on cardiac function and collateral vessel formation in the microembolized rabbit heart.

The effects of gene transfer of the secreted form of fibroblast growth factor-2 (FGF-2) were tested using an adenovirus vector in the microembolized rabbit heart. Japanese white rabbits underwent an intracoronary injection of 25-microm microspheres followed by recombinant adenovirus vectors encoding a secreted form of FGF-2 (FGF group), LacZ (LacZ group), or saline (saline group). Left ventricular (LV) systolic function was serially assessed by echocardiography. Vascular density was measured at 14 days with Azan and CD31 staining. The development of collateral vessels was assessed by measuring myocardial blood flow before and after the occlusion of the left anterior descending coronary artery. Percent fractional shortening (%FS) decreased after the microembolization, and improved gradually for 14 days in the FGF group only (41+/-1% (FGF) vs 32+/-1% (LacZ), 31+/-1% (saline), p<0.01). The vascular density and myocardial collateral blood flow were significantly higher in the FGF group in comparison with other groups. Transcoronary arterial gene transfer of the secreted form of FGF-2 was beneficial for the recovery of LV systolic function and development of collateral vessels in the microembolized rabbit heart.

Animals↗
PubMed2001

Substrate recognition mechanism of carboxypeptidase Y.

To clarify the substrate-recognition mechanism of carboxypeptidase Y, Fmoc-(Glu)n Ala-OH (n = 1 to 6), Fmoc-(Glu)n Ala-NH2 (1 to 5), and Fmoc-Lys(Glu)3Ala-NH2 were synthesized, and kinetic parameters for these substrates were measured. Km for Fmoc-peptides significantly decreased as peptide length increased from n = 1 to n = 5 with only slight changes in kcat. Km for Fmoc-(Glu)(5,6)Ala-OH were almost the same as one for protein substrates described previously (Nakase et al., Bull. Chem. Soc. Jpn., 73, 2587-2590). These results show that the enzyme has six subsites (S1' and S1-S5). Each subsite affinity calculated from the Km revealed subsite properties, and from the differences of subsite affinity between pH 6.5 and 5.0, the residues in each subsite were predicted. For Fmoc-peptide amide substrates, the priorities of amidase and carboxamide peptidase activities were dependent on the substrate. It is likely that the interactions between side chains of peptide and subsites compensate for the lack of P1'-S1' interaction, so the amidase activity prevailed for Fmoc-(Glu)(3,5)Ala-NH2. These results suggest that these subsites contribute extensively to substrate recognition rather than a hydrogen bond network.

Amino Acid Sequence↗
PubMed2001

Investigation of the short-term effect of chemonucleolysis with chondroitinase ABC.

Chondroitinase ABC (C-ABC) is expected to be a novel agent for chemonucleolysis. The effect of C-ABC was investigated by magnetic resonance (MR) and radiograph. C-ABC was administered into the lumbar intervertebral disks on the clinically normal beagles (n=5), in a dose of 50 microl (12.5 units as C-ABC). MR scans were performed pre-dose, and 1, 3, 7, 14 and 28 days after administration of C-ABC, and the signal intensity (SI) of the nucleus pulposus was measured. Radiographs were taken pre-dose, and 1, 2, 3, 4, 5, 6, 7, 14 and 28 days post-dose, to evaluate narrowing of the disk space in terms of height index (HI). In addition, the quantity of the chondroitin sulfate (CS) and the hyaluronic acid (HA) in the nucleus pulposus were measured by high performance liquid chromatography on day 28 after dosing. SI and HI continuously decreased, following the injection to 37.1% and 78.9% of the pre-dose values, respectively. Statistically significant differences (p<0.01) were observed between the C-ABC group and the control group in the respects on day 1 post-dose. CS and HA contents of the nucleus pulposus were noted to be significantly decreased on day 28 (p<0.01) in the treated group. This agent proved to degenerate proteoglycans in the nucleus pulposus, thus progressively reducing the interdiskal pressure from day 1 post-dose onwards. It is concluded that C-ABC is expected to afford its efficacy from early in the course of chemonucleolysis.

Animals↗
PubMed2001

Spinal extradural arachnoid cyst--case report.

A 48-year-old male presented with progressive leg weakness. Magnetic resonance imaging and computed tomography myelography showed an extradural arachnoid cyst extending from the T-12 to L-2 levels in the thoracolumbar region. The cyst was confirmed at surgery and completely removed. This surgical intervention achieved improvement in the neurological symptoms.

Arachnoid Cysts↗