Development of a highly efficient implanted thermal ablation device: in vivo experiment in rat liver.

OBJECTIVES: To evaluate an implanted thermal ablation device that can be heated with high efficiency using a resonant circuit as the implant. METHODS: 16 rats were used. The implants, adjusted at a resonance frequency of 4 MHz, were fixed on the surface of the liver of rats under laparotomy. In 14 of 16 rats, an alternating magnetic field (AMF) was applied for 6 min with an output of 300 W from outside the body using a ferrite core applicator. The implant temperature during AMF exposure was measured. The 14 rats were divided into 5 groups, depending on time from AMF application until they were sacrificed (1 h, 1 day, 3 days, 7 days and 1 month after application). Two rats not exposed to AMF were used as controls. Livers were removed and evaluated; the cross-sectional area and width of the ablated region were measured. RESULTS: During AMF exposure, the implant temperature rose to 127.8±39.3 °C (mean±standard deviation). The cross-sectional area of the ablated region was largest after 1 day and tended to decrease with time. The widths of the ablated region were 4.87±0.22 mm, 4.15±0.36 mm, 3.67±0.58 mm and 3.24±0.16 mm in the 1 day, 3 day, 7 day and 1 month groups, respectively. No significant differences (p<0.05) were seen in either cross-sectional area or width of the ablated region. CONCLUSION: Sufficient heat for ablation was obtained in vivo using a newly developed implanted thermal ablation device. This device may be a new option for thermal ablation therapy.

Frequent loss of heterozygosity at 3p25-p26 is associated with invasive oral squamous cell carcinoma.

Recent molecular evidence suggests that allelic deletions of chromosomes are involved in the carcinogenesis of various neoplasms, including oral squamous cell carcinoma (OSCC). To determine the role of 3p deletions in Japanese OSCC and to define the localization of putative tumor suppressor genes, we initially examined loss of heterozygosity (LOH), using nine microsatellite markers in 36 OSCCs and 28 oral epithelial dysplastic lesions (OEDLs). LOH on chromosome 3p was observed at one or more loci in 72% of OSCCs and 18% of OEDLs. Fourteen (61%) of 23 OSCC patients informative at D3S2450 (3pter-p24.2) showed LOH most frequently, in contrast to OEDL, where LOH was never seen at this locus. Interestingly, we found a significant association between an allelic deletion at this locus and the histologic grade of mode of tumor invasion. Therefore, we also examined allelic deletion on chromosome 3p telomeric to where D3S2450 was located. A common deletion region was identified between D3S2450 and D3S3591. Our results provide evidence for the presence of a tumor suppressor gene in a 0.8-cM region bordered by D3S2450 and D3S3591 at 3p25-p26, which may play a role in carcinogenesis and invasion of OSCC.

Resolution and synthesis of optically active alcohols with immobilized ovalbumin and pea protein as new bio-catalysts.

It was found that ovalbumin stereoselectively oxidized one of the enantiomers of p-substituted racemic alcohols, thereby providing optically active alcohols with high optical purities. It was found out that, when used appropriately in combination with immobilized pea protein, immobilized ovalbumin made it possible to resolve and synthesize racemic 1-(2-naphthyl)ethanol, 1-phenylethanol, and 1-phenyl-1-propanol. Immobilized ovalbumin could be continuously recycled at least three times without lowering the yield and purity of the products. These results suggested that cereals, beans, and ovalbumin might have additional fourth function among conventional foods. Namely, there might contain nutritional, sensory, biologically regulatory and bio-catalytic functions in conventional foods.

Keratin mRNA for detecting micrometastasis in cervical lymph nodes of oral cancer.

We studied three keratin (K) gene candidates, K13, K19, and K20 mRNAs, for detecting micrometastases in cervical lymph nodes (LNs) by reverse transcriptase-polymerase chain reaction (RT-PCR). Of 166 histologically metastasis-negative nodes, 24 micrometastatic LNs (14. 4%) were detected based on K13 gene expression. Keratin 19 mRNA is an inadequate marker for the genetic diagnosis due to not only illegitimate gene expression from lymphatic tissue but also gene expression from the ectopic salivary gland. Keratin 20 mRNA showed low sensitivity. It is suggested that K13 mRNA may be a promising tumor marker among these keratin genes for detecting the micrometastases in cervical LNs of oral cancer.

Tyrosinase inhibitory activity of Bangladeshi indigenous medicinal plants.

The tyrosinase-inhibitory activity of 15 kinds of Bangladeshi medicinal plants was evaluated. Methanol extracts were prepared for screening tests, and other kinds of extracts were also studied for those with high activity. Swertia chirata, Piper nigrum, Glycyrrhiza glabra, Piper longam and Ocimum americanum were screened as highly inhibiting samples. Methanol was found to be the most efficient solvent for extracting the active compounds. The 50% tyrosinase-inhibitory concentration of the Glycyrrhiza glabra methanol extract was 21.2 microg/ml.

Histological study on pN upgrading of oral cancer.

The International Union Against Cancer (UICC) does not define the number of sections required from each regional lymph node to record pTNM classification. This study was designed to clarify the incidence of occult metastasis and to assess the pN upgrading of patients with oral cancer. Ultimately, this study led to a proposal for appropriate semiserial sectioning guidelines. Five hundred fifty-four nonmetastatic cervical lymph nodes taken from 73 patients with oral cancer were subjected to hematoxylin-eosin (HE) staining and keratin immunohistochemistry. Micrometastases, defined as foci < or =3 mm, were detected in 29 sites of 23 lymph nodes (4.2%) of 16 patients (21.9%). In 9 patients (12.3%) pN upgrading was needed: in 6 from pN0 to pN1, in 1 from pN0 to pN2b, and in 2 from pN1 to pN2b. The remaining 13 lymph nodes with occult metastasis were found in 5 pN2b and 2 pN2c patients, resulting in no pN upgrading. Occult metastasis was also detected in 6 small lymph nodes < or =5 mm in diameter. The average minor axis of the micrometastasis was 1.36-/+0.85 mm. We propose that the lymph nodes should be cut and examined at 1-mm intervals to detect micrometastatic foci and to evaluate the pN classification accurately.

Indication for epidural morphine for the relief of intractable pain in advanced oral cancer: report of four cases.

It can be difficult to manage the pain of advanced oral cancer. We present four patients in whom epidural morphine was used for intractable pain at primary or metastatic sites. For pain supplied by the trigeminal or cervical nerve a small dose of morphine was given through an epidural catheter inserted into the epidural space through C7-Th1. A favourable clinical response was achieved in three. In particular, in one patient who was given continuous morphine using a computerized ambulatory drug delivery system, we achieved excellent efficacy and stable control of pain. We think that the effect of the epidural morphine was decreased in the patient who did not respond because he had previously been treated with high oral doses. The present study confirmed that morphine given epidurally in small doses has a strong and prolonged analgesic action with less toxicity than when given orally.

Resolution and synthesis of optically active alcohols with immobilized water-soluble proteins from green pea, soybean and buckwheat as new bio-catalysts.

Kinetic resolution of racemic alcohols, (+/-)-1-(4-substituted phenyl)ethanol and (+/-)-1-(2-naphthyl)ethanol, was done with immobilized green pea, soybean, or buckwheat proteins. The resolution was done stereoselectively by oxidizing only one enantiomer of a racemic alcohol to leave an optically active alcohol with a high purity. In addition, each protein could be reused consecutively at least three times without any decrease of yield or optical purity.

Superoxide-scavenging and prolyl endopeptidase inhibitory activities of Bangladeshi indigenous medicinal plants.

The superoxide-scavenging and prolyl endopeptidase (PEP) inhibitory activities of 15 different kinds of Bangladeshi medicinal plants were evaluated. Methanol extraction was performed for the screening tests. Swertia chirata, Emblica officinalis, Zingiber officinale and Myristica malabarica were screened as superoxide-scavenging samples. Similarly, E. officinalis was identified as one of the strongest PEP inhibitory samples. The 50% (O2-)-scavenging and PEP-inhibitory concentrations from E. officinalis methanol extracts were found to be 13.17 and 26.10 microg/ml, respectively.

Clinical usefulness of telomerase assay for the detection of lymph node metastasis in patients with oral malignancy.

OBJECTIVE: Telomerase is considered a diagnostic marker of malignancy. We investigated the usefulness of telomerase assay for the detection of lymph node micrometastasis. METHODS: Sixteen cervical lymph nodes with metastasis of oral cancer and 20 benign lymph nodes were studied. The oral cancer cell line was used to estimate the sensitivity for telomerase assay. Telomerase activity was measured by semiquantitative telomeric repeat amplification protocol. RESULTS: There was a significant difference between malignant and benign lymph nodes. The telomerase activity of 50 mg of lymph nodes with 103 or more cancer cells differed from that of control lymph nodes. Lymph nodes with 102 or fewer tumor cells expressed similar levels as benign lymph nodes. CONCLUSIONS: In addition to routine histologic examination, telomerase assay is considered a useful tool for the detection of lymph node metastasis in patients with oral malignancy.

Synthesis and biological activities of ferulic acid derivatives.

Three types of ferulic acid derivatives (feruloylaminoacid benzyl or methyl esters, feruloylaminoacids, and 4-0-[N-(carbobenzyloxy)-aminoacyl] ferulic acid) were synthesized by introduction of amino acids at different sites and their platelet aggregation (PA)-inhibitory, tyrosinase-inhibitory, angiotensin converting enzyme (ACE)-inhibitory, and superoxide dismutase (SOD)-like activities were evaluated. PA, one of the mechanisms involved in repair of blood vessel injury, is related to diseases such as thrombosis. Developing a compound capable of inhibiting PA may thus provide a therapeutic tool. From the results of study, particularly in the case of 4-0-[N-(carbobenzyloxy) aminoacyl] ferulic acid (amino acid components: isoleucine, proline), inhibition of collagen-induced aggregation was maintained of the same level as with ferulic acid, but stronger dissociation of ADP-induced aggregation was detected. In other words, these compounds may not only prevent thrombosis but also dissolve thrombi. Further, the compounds with stronger tyrosinase-inhibitory activity were found to scavenge superoxide as effectively as ferulic acid. Since they are also more hydrophobic, they may be particularly efficacious as cosmetic ingredients. Finally, feruloyl-Phe-Ala-Pro-OH had strong ACE inhibitory activity (IC50 = 1.5 microM) lacking in the case of ferulic acid itself.

Resolution and synthesis of (S)-1-(2-naphthyl)ethanol with immobilized pea protein: as a new biocatalyst.

(S)-1-(2-Naphthyl)ethanol was yielded by immobilized pea (Pisum sativum L.) protein (IPP) from (R, S) 2-naphthyl ethanol (> 99% ee, yield; about 50%), in which the (R)-enantiomer was selectively oxidized to 2-acetonaphthone. IPP could be reused consecutively at least three times without any decrease of yield and optical purity.

"Chain-link" combined tissue transfer for the reconstruction of the mandible.

We describe a procedure for "chain-link" combined tissue transfer connecting the vascular pedicle of a deep circumflex iliac flap with that of a forearm flap after wide resection of the mandible. Combination of these flaps facilitated the reconstruction of the defect in both intra- and extraoral soft tissue and the mandibular bone. This method is useful when cervical recipient blood vessels are limited due to the wide resection of the primary tumor and radical neck dissection.

Superoxide-scavenging and Tyrosinase-inhibitory Activities of the Extracts of Some Chinese Medicines.

The superoxide-scavenging and the tyrosinase-inhibitory activities of 28 kinds of plants used as Chinese medicines were evaluated. Methanol/water extracts were used for the screening tests, and for those which represented high activities, other kinds of extracts were also studied. The extracts of Mallotus japonicus Muell. Arg. scavenged superoxide strongly; the half-inhibiting concentration (IC50) of its 50% methanol/water extract was 10.57 µg of dried material in 1 ml of reaction mixture. The extracts of Fntillaria thunbergii Miq., Carthamus tinctorius L., and Prunus persica (L.) Batsch had strong tyrosinase-inhibitory activities, and the extracts of Scutellariu baicalensis Georgi represented both kinds of activities. These facts suggested that Chinese medicines may be a treasure house of chemical compounds that have the superoxide-scavenging and the tyrosinase-inhibitory activities.

Increased plasma level of platelet-activating factor (PAF) and decreased serum PAF acetylhydrolase (PAFAH) activity in adults with bronchial asthma.

We evaluated the plasma level of platelet-activating factor (PAF), a chemical mediator that induces various symptoms of bronchial asthma, and the activity of serum PAF acetylhydrolase (PAFAH), an enzyme that specifically inactivates PAF, in adults with bronchial asthma. Measurements were made by radioimmunoassay of samples obtained from 137 adult asthmatic patients (137 cases examined in remission and from among these 41 cases were also measured at the time of an asthmatic attack) 59 adult patients with untreated pulmonary tuberculosis and 106 healthy adult volunteers. It was demonstrated that the plasma PAF level was markedly higher and the serum PAFAH activity markedly lower in the asthmatic patients, both in remission and at the time of asthmatic attack, than in the healthy volunteers. The plasma PAF level was more closely associated with asthma both in remission and at the time of asthmatic attack than with pulmonary tuberculosis, whereas there was no significant difference in the serum PAFAH activity between the two diseases. The low serum PAFAH activity in the asthmatic patients may have been due to saturation as a result of continuous reaction to the increased plasma PAF level in those patients.

Taste evaluations of angiotensin I converting enzyme inhibitors, Leu-Lys-Tyr analogues.

Tastes of Leu-Lys-Tyr (LKY) analogues, a series of potent angiotensin I converting enzyme (ACE) inhibitory peptides were evaluated. Some of these analogues were found to be sweet, such as Val-Lys-Tyr and Ala-Orn-Tyr. Furthermore, the structural requirements for sweetness or decreasing the bitterness were investigated by considerations of the structure-taste relationship with LKY analogues.

Effects of normal and their branched alcohols with structurally minimal variation on kinetic parameters in thermolysin-catalyzed peptide hydrolysis and synthesis of N-(benzyloxycarbonyl)-L-phenylalanyl-L-phenylalanine and its methyl ester.

When higher alcoholic solvents were added to the reaction medium, and the enhancement of the enzyme activity, followed by its reduction then inactivation, were observed in thermolysin-catalyzed peptide hydrolysis and synthesis. The organic solvent content used was less than the saturating concentration in the buffer (i.e., water-organic one-phase system). The kinetic parameters, Km and kcat, at the alcoholic concentration giving maximal enzyme activity in these reactions changed linearly with increasing logP values of the alcohols and consequently kcat/Km as well. When the branched isomers of alcohols with structurally minimal variation of which logP was equivalent theoretically, were used as annexments, the kinetic parameters were also changed. The results, especially the changes of Km for each organic solvent, suggested that each alcohol should act at the active site of the enzyme in its own effective mode.