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Biomedical subjects

Tomomi Harada

Publications and source records attributed to Tomomi Harada.

5 recordsLinked to original sources

Anion recognition by a silanediol-based receptor.

To explore the anion recognition ability of silanol hydroxy groups, a silanediol-based receptor 1 was prepared. Spectroscopic studies and X-ray crystallography revealed that the receptor exhibits the characteristic recognition of anions via two hydrogen bonds in chloroform.

Journal Article↗

Clinical usefulness of serum telomerase reverse transcriptase (hTERT) mRNA and epidermal growth factor receptor (EGFR) mRNA as a novel tumor marker for lung cancer.

Using a newly developed assay of telomerase reverse transcriptase (hTERT) mRNA in serum by real-time RT-PCR, we previously reported this assay to be superior to other tumor markers for hepatoma. In this study, we aimed to clarify its clinical significance as a biomarker for lung cancer. In 112 patients with lung tumor and 80 individuals without cancer, we measured serum hTERT mRNA and epidermal growth factor receptor (EGFR) mRNA levels, using a quantitative one-step real-time RT-PCR assay. We examined its sensitivity and specificity in lung cancer diagnosis, its clinical significance in comparison with other tumor markers, and its correlation with the clinical parameters using multivariate analyses and correlation relative tests. The copy number of serum hTERT mRNA was independently correlated with tumor size, tumor number, presence of metastasis and recurrence, and smoking (all P < 0.05). EGFR mRNA correlated with tumor number and clinical stage (both P < 0.05). The sensitivity and specificity in lung cancer diagnosis were 89.0% and 72.7% for hTERT mRNA, and 71.3% and 80.0% for EGFR mRNA, respectively. hTERT mRNA was superior to other tumor markers in lung cancer diagnosis. For both mRNAs, serum levels were significantly correlated with levels in lung cancer tissues (both P < 0.05). The copy number of hTERT mRNA significantly decreased after the surgical treatment. The data suggest that hTERT mRNA, especially when combined with EGFR mRNA, is a novel and excellent biomarker for pulmonary malignancies to diagnose and assess the clinical stage.

Adenocarcinoma↗

Serum human telomerase reverse transcriptase messenger RNA as a novel tumor marker for hepatocellular carcinoma.

PURPOSE: We previously reported the usefulness of a qualified highly sensitive detection method for human telomerase reverse transcriptase (hTERT) mRNA in serum with 89.7% sensitivity for hepatocellular carcinoma (HCC). In this study, we developed a quantitative detection method for serum hTERT mRNA and examined the clinical significance in HCC diagnosis. EXPERIMENTAL BACKGROUND: In 64 patients with HCC, 20 with liver cirrhosis, 20 with chronic hepatitis, and 50 healthy individuals, we measured serum hTERT mRNA by using the newly developed real-time quantitative reverse transcription-PCR with SYBR Green I. We examined its sensitivity and specificity in HCC diagnosis, clinical significance in comparison with other tumor markers, and its correlations with the clinical variables by using multivariate analyses. RESULTS: Serum hTERT mRNA showed higher values in patients with HCC than those with chronic liver diseases. hTERT mRNA expression was shown to be independently correlated with clinical variables such as tumor size, number, and degree of differentiation (P < 0.001, each). The sensitivity/specificity of hTERT mRNA and alpha-fetoprotein (AFP) mRNA in HCC diagnosis were 88.2%/70.0% for hTERT and 71.6%/67.5% for AFP, respectively. hTERT mRNA proved to be superior to AFP mRNA, AFP, and des-gamma-carboxy prothrombin in HCC diagnosis. Furthermore, hTERT mRNA in serum was associated with that in HCC tissue. CONCLUSIONS: The usefulness of hTERT mRNA expression in HCC diagnosis and its superiority to conventional tumor markers were shown. Therefore, serum hTERT mRNA is a novel and available marker for HCC diagnosis.

Adult↗

Trapidil enhances the slowly activating delayed rectifier potassium current and suppresses the transient inward current induced by catecholamine in Guinea pig ventricular myocytes.

We examined the electrophysiological effects of trapidil on the ionic currents influencing the repolarization and on the transient inward current (ITi) that can cause triggered arrhythmia using the whole-cell patch-clamp technique in guinea pig ventricular myocytes. Trapidil shortened the action potential duration (APD) and increased the delayed rectifier potassium current (IK) in a concentration-dependent manner. The effect of trapidil on the rapidly and slowly activating components of IK (IKr and IKs, respectively) was studied by the envelope of tails test. Trapidil failed to affect IKr and selectively enhanced IKs. Trapidil increased the amplitude of the L-type Ca2+ current (ICa,L), with an acceleration of its inactivation, whereas isoproterenol, a beta-adrenoceptor agonist, increased the amplitude of the ICa,L in a different manner. Isoproterenol activated ITi; however, trapidil not only failed to facilitate ITi but also suppressed isoproterenol-induced ITi. The inhibitory effect of trapidil on isoproterenol-induced ITi is at least partly via a reduction of Ca2+ overload through an acceleration of ICa,L inactivation and/or a sarcoplasmic reticulum (SR) Ca channel modulation. These results suggest that trapidil does not prolong the QT interval and has an antiarrhythmic effect on arrhythmias elicited by triggered activity secondary to Ca2+ overload at much higher concentrations than clinical concentration.

Action Potentials↗

[Effects of concentration and dosage of lidocaine on preventing the pain on injection of propofol].

Although it is well-known that 2% lidocaine has an effective action for preventing propofol-induced pain, it has been unclear whether or not lidocaine of the concentration below 2% has the effective action similar to 2% lidocaine. One-hundred and thirty-two patients were randomly assigned to one of the six groups according to concentration and dosage of lidocaine administered at the time of the initiation of propofol infusion. Groups I and II received 1 ml and 2 ml of 1% lidocaine, respectively; Groups III and IV were given 1 ml and 2 ml of 0.5% lidocaine, respectively; Group V received 2 ml of 2% lidocaine; Group VI was administered 1 ml of normal saline as a control. There were no significant differences in patients' profiles and alterations of hemodynamics during anesthetic induction among the six groups. Number of patients complaining of a pain during induction was more in Group VI with significance (P < 0.0001) and number of patients complaining of uncomfortableness was also more with significance (P < 0.0001). Incidence of propofol-induced pain and degree of satisfaction with anesthetic induction were similar among the groups receiving lidocaine. Even 0.5% lidocaine may have the same effective action as 2% lidocaine for preventing the pain on injection of propofol.

Adult↗