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Biomedical subjects

K Nakamori

Publications and source records attributed to K Nakamori.

At least 19 recordsLinked to original sources
PubMed2006

Predictive assay of neoadjuvant chemotherapy in management of oral cancer.

Neoadjuvant chemotherapy (NAC) for oral squamous cell carcinoma has a positive impact on organ preservation and/or survival only in patients who achieve an excellent anti-tumour effect with this therapy. Predictive assay for NAC can play an important role in establishing tailor-made treatments for oral squamous cell carcinoma. In this retrospective study, the anti-tumour effects of cisplatin-based NAC in 70 patients with oral squamous cell carcinoma were reviewed in relation to biological markers of tumour cell proliferation activity: tumour grade, cellular DNA content, mitotic index, apoptotic index, ki-67 positive rate, and p53 and Bax expression. Tumour grade, Bax expression, apoptotic index and cellular DNA content were significantly correlated with the anti-tumour effects of NAC in univariate analysis. Tumour grade, Bax expression and apoptotic index were selected as independent predictive factors by means of multiple logistic analysis. Using the regression equation from these results, the prediction rate for anti-tumour effects was 70%. For patients in whom NAC is predicted to be ineffective, it may be necessary to choose another treatment option in order to improve their survival and quality of life.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2005

Aberrant expression of beta- and gamma-catenin is an independent prognostic marker in oral squamous cell carcinoma.

Alteration in expression of E-cadherin and catenins is associated with loss of differentiation, acquisition of an invasive phenotype and poor clinical outcome in many types of cancer. To identify molecular prognostic markers, membrane expression levels of E-cadherin, and alpha-, beta- and gamma-catenin in biopsy samples (n=135) of oral squamous cell carcinoma (OSCC) were evaluated immunohistochemically in relation to preoperative tumour-related features, clinical course and prognostic value, and were found to be significantly correlated with an endophytic growth pattern and pathologically proved lymph-node metastasis. Alteration of expression of E-cadherin, and alpha-, beta- and gamma-catenin was also significantly correlated with poor disease-specific 5-year survival (P=0.0096, 0.0434, 0.0005 and 0.0005, respectively). Multivariate Cox proportional hazard regression analysis showed that alteration of beta- and gamma-catenin expression was a significantly independent prognostic parameter for survival (P=0.0112 and 0.0088, respectively), as was the case with endophytic growth pattern and advanced N-category. These results indicate that patients with OSCC and absent or reduced membrane expression of beta- and gamma-catenin should be considered a high-risk group for regional lymph-node metastasis and poor prognosis.

Adult↗
PubMed1999

Increase of antioxidative potential of rat plasma by oral administration of proanthocyanidin-rich extract from grape seeds.

The effect of a single oral administration of proanthocyanidins, oligomeric and polymeric polyhydroxyflavan-3-ol units, on the antioxidative potential of blood plasma was studied in rats. Proanthocyanidin-rich extract from grape seeds was administered by intragastric intubation to fasted rats at 250 mg/kg of body weight. The plasma obtained from water- or proanthocyanidin-administered rats was oxidized by incubation with copper sulfate or 2, 2'-azobis(2-amidinopropane) dihydrochloride (AAPH) at 37 degrees C, and the formation of cholesteryl ester hydroperoxides (CE-OOH) was followed. The plasma obtained from proanthocyanidin-administered rats was significantly more resistant against both copper ion-induced and AAPH-induced formation of CE-OOH than that from control rats. The lag phase in the copper ion-induced oxidation of rat plasma was remarkably increased at 15 min after administration of proanthocyanidins and reached a maximum level at 30 min. When the plasma from proanthocyanidin-administered rat was hydrolyzed by sulfatase and beta-glucuronidase following analysis by high-performance liquid chromatography with electrochemical detection, metabolites of proanthocyanidins occurred in rat plasma at 15 min after administration, three peaks of which were identified as gallic acid, (+)-catechin, and (-)-epicatechin. These results suggest that the intake of proanthocyanidins, the major polyphenols in red wine, increases the resistance of blood plasma against oxidative stress and may contribute to physiological functions of plant food including wine through their in vivo antioxidative ability.

Administration, Oral↗
PubMed1999

Efficacy and safety of infrared warming of the eyelids.

PURPOSE: To evaluate our newly developed infrared heater (IRH) and compare it to a broad-spectrum heater (BSH) for warming the eyelids. MATERIALS AND METHODS: Ten normal subjects were enrolled in this study. All measurements were recorded in a room with temperature 23 degrees C, 40% humidity, and no wind. The IRH is composed of two hard eye patches that have light-emitting diodes (LEDs) emitting near-infrared radiation. We first compared the temperature rises in the cornea, lacrimal gland, and eyelids after warming through closed eyelids with the IRH for 5 and 10 min. Next, we compared warming with the IRH or BSH for 30 min. We then used the IRH for 5 min with the eyes open to confirm its safety. Finally, we determined subjective feeling after warming the eyes. RESULTS: Direct comparison of 5 versus 10 min of warming with the IRH showed no significant differences in temperature rises in the upper eyelid (p = 0.09). The IRH caused significantly more heating (p < 0.05) than did the BSH everywhere except the cornea. The temperatures never rose above 37.7 degrees C for either heater during 30 min or with the IRH with the eyes open for 5 min. The subjects' comfort level rose significantly (p < 0.05) after treatment with the IRH. CONCLUSIONS: Our study showed the efficacy and safety of warming the eyelids with a newly developed IRH. Only 5 min is necessary to increase ocular temperature and enhance comfort.

Adult↗
PubMed1997

Multivariate analysis of occult lymph node metastasis as a prognostic indicator for patients with squamous cell carcinoma of the oral cavity.

BACKGROUND: The biologic aggressiveness of squamous cell carcinoma of the oral cavity is reflected in its ability to metastasize to regional cervical lymph nodes. Patients with clinically negative cervical lymph nodes are believed to have a good prognosis; however, the prognosis of patients with lymph node metastasis occurring after excision or radiotherapy of the primary tumor is poor. METHODS: Univariate and multivariate analyses for occult lymph node metastasis (ONM) in 172 patients with clinically negative cervical lymph nodes were performed by the authors to elucidate the clinical and histologic tumor risk factors to enhance their ability to predict ONM. A multivariate Cox proportional hazards model and Hayashi's quantification theory type II were used to analyze prognostic factors and to determine the probability of ONM. RESULTS: Using Cox's proportional regression model, the factors linked to cancer specific survival were selected: tumor differentiation (P = 0.0330), mode of carcinoma invasion (P = 0.0175), and ONM (P = 0.0433). Pathologically identified metastatic lymph nodes were found in 21.5% of the cases studied (37 of 172 cases). The 5-year cancer specific survival was 94.0% for patients without lymph node metastasis, and 51.0% for patients with ONM (P < 0.0001, log rank test). The most significant predictors for ONM of each of the clinical and histologic factors, in descending order, were: mode of carcinoma invasion, intensity of lymphocytic infiltration, degree of differentiation, number of mitotic figures, and type of growth by means of Hayashi's quantification theory type II. The presence or absence of ONM in 147 of 172 patients (85.5%) was correctly predicted by the score at the point of intersection of the two curves, which was -0.03. Further investigation revealed that 28 of 32 new cases were differentiated accurately by means of this diagnostic system. CONCLUSIONS: The results of the current study suggest that this method of analysis can establish a reliable predictor of ONM, thereby facilitating correct choices for surgical procedures to enhance the survival rates of patients with clinically negative cervical lymph nodes.

Adult↗
PubMed1997

Blinking is controlled primarily by ocular surface conditions.

PURPOSE: To investigate the relation between blinking and ocular surface conditions and to introduce and examine a new index, the maximum blink interval. METHODS: In a prospective study, the blink rate of subjects under relaxed conditions was determined from a video recording taken by a hidden observer. The maximum blink interval was defined as the longest time subjects can avoid blinking without feeling uncomfortable. RESULTS: Significant changes in the blink rate and maximum blink interval were induced by factors that directly or indirectly affect the ocular surface: topical anesthesia, changing exposed ocular surface area, and wind. Moreover, the blink rate and maximum blink interval were significantly different in dry eye patients compared with healthy volunteers, with the values of the former approaching the values of the latter after use of artificial tears. The maximum blink interval was decreased by the same factors that increased the blink rate, and there was a significant inverse correlation between blink rate and maximum blink interval. Use of video display terminals was associated with decreased maximum blink interval and, hence, the development of dry eye symptoms. CONCLUSIONS: There was an important association among blink rate, maximum blink interval, and ocular surface conditions. The blink rate and our newly introduced measurement, the maximum blink interval, should prove useful in assessing factors that cause dry eye. This prospective study should contribute to the understanding and treatment of dry eyes.

Administration, Topical↗
PubMed1996

Quantitative videographic analysis of blinking in normal subjects and patients with dry eye.

OBJECTIVE: To study patterns of eye blinking in normal subjects and patients with dry eye. METHODS: We developed an automated, noninvasive blink monitor that permits quantitative analysis of 6 parameters of blinking. We used this method under normal conditions and then examined the effects on the patterns of blinking in patients with dry eye; several steps in this method were designed to exacerbate or ameliorate ocular surface desiccation. RESULTS: The mean (+/-SD), maximum, and coefficient of variation of the interblinking time in normal subjects and patients with dry eye were 4.0 +/- 2.0 and 1.5 +/- 0.9 seconds, 8.9 +/- 4.0 and 4.2 +/- 2.4 seconds, and 55% +/- 21% and 65% +/- 24%, respectively. Those values for the blinking time were 0.20 +/- 0.04 and 0.27 +/- 0.16 seconds, 0.35 +/- 0.12 and 0.99 +/- 1.30 seconds, and 23% +/- 9% and 46% +/- 34%, respectively. The use of artificial tears or spectacles with moist panels and moist inserts tended to normalize the patterns of blinking in the patients with dry eye, whereas exposure to wind made them more abnormal. CONCLUSIONS: Our technique permitted a rigorous analysis of blinking that was previously unavailable. We have shown that local ocular surface conditions alone can significantly affect patterns of blinking. This method should be applicable to studying psychologic and any other factors that may influence blinking.

Adolescent↗
PubMed1996

The reactivity of taurine with hypochlorous acid and its application for eye drops.

The ability of taurine to protect biomembranes attacked by HOCl was examined using canine erythrocytes which had been pre-treated with HOCl. Of the amino acids tested, taurine was the most effective in inhibiting attack by HOCl, followed by glycine, alpha-alanine and beta-alanine. During the incubation of HOCl-treated erythrocytes with taurine, an appreciable amount of monochlorotaurine (TauNHCl) was detected in the supernatant. This suggests that taurine may remove the oxidized chlorine from HOCl-treated erythrocytes, resulting in the production of TauNHCl. The effect of taurine on the removal of Cl+ moiety was examined using Sepharose gel with amino groups. Taurine removed Cl+ from HOCl-treated Sepharose gel. The yield of TauNHCl depended on the concentration of taurine. The effectiveness of taurine in preventing ocular surface damage caused by HOCl was investigated in albino rabbits. The activity of lactate dehydrogenase (LDH) released from ocular tissues into tears during eye irritation was used as an index of ocular surface damage. Taurine effectively protected ocular surface tissues from damage induced by HOCl, and arrested the progression of tissue damage that had already been initiated by HOCl. These finding suggest that taurine may be clinically useful in the treatment of ocular surface damage caused by oxidants such as HOCl.

Alanine↗
PubMed1995

Effects of ocular surface area and blink rate on tear dynamics.

OBJECTIVE: To study the effects of exposed ocular surface area and blink rate on tear dynamics by the measurement of tear evaporation under a range of conditions. METHODS: Tear evaporation was measured in three gaze positions in 15 normal volunteers, and the ocular surface area was determined as a function of the width of the palpebral fissure. In 17 normal volunteers, the effect of blink rate on tear evaporation was assessed. RESULTS: The ocular surface area was 1.2 +/- 0.27, 2.2 +/- 0.39, and 3.0 +/- 0.33 cm2 with patients looking down, ahead, and up, respectively. The corresponding tear evaporation rates per eye were 7.0 +/- 3.5, 17.6 +/- 6.6, and 23.7 +/- 6.3 x 10(-7) g/s, respectively. The tear evaporation per square meter also increased proportionally with the ocular surface area. When the blink rate was changed from 10 to 60 per minute, the tear evaporation did not change in those individuals with evaporation rates more than 7.8 x 10(-7) g/s per square centimeter, whereas it did increase with the blink rate in those whose evaporation rates were lower. CONCLUSIONS: Ocular surface area and blink rate affect tear dynamics. Moderate palpebral fissure width and blink rate are necessary for the prevention of desiccation of the ocular surface.

Adult↗
PubMed1995

Spindle cell hemangioendothelioma: an immunohistochemical and flow cytometric study of six cases.

Six cases of spindle cell hemangioendothelioma (SCH) are presented with immunohistochemical and flow cytometric analyses. One case was associated with Maffucci's syndrome. All lesions were solitary or multifocal in the extremities, and prepresentation duration ranged from years to decades. One case recurred but none had metastases. Histologically, in four of the six cases the main lesions appeared to arise within vessels, predominantly muscular vessels. All lesions consisted of cavernous hemangioma-like areas and solid cellular areas resembling Kaposi's sarcoma. Cellular atypia was minimal. At the periphery of the lesions, a cluster of large thick or thin walled, and probably malformed, vessels were observed. Immunohistochemically, factor-VIII related antigen, CD34, vimentin, and lectin binding Ulex europaeus agglutinin 1 stained endothelial cells lining vascular channels, and vacuolated, or epithelioid cells. Spindle cells in the solid areas were negative for these endothelial markers except for vimentin, but showed divergent positive immunoreactions of HHF35, alpha-smooth muscle actin, desmin, and collagen type IV. Five cases were diploid and one was aneuploid. There was no significant correlation among DNA ploidy, S-phase fraction, and local recurrence in SCH although the number of cases examined was small. These results suggest SCH may be a benign lesion, probably a reactive process, rather than a low-grade angiosarcoma.

Adult↗
PubMed1994

Study on the detection of implantation site in rabbits.

In this study, an alkaline treatment was applied to the observation of implantation site in rabbits. Embryos in pregnant rabbits were stabbed to death on days 7, 8, 9, 10 and 18 of gestation. These animals were sacrificed on day 29. The uteri were removed, immersed in 2% sodium hydroxide and fixed with 10% buffered formalin. After the alkaline treatment, all of the implantation sites were clearly recognizable as white tissue since the other parts became fairly transparent. Even after the formalin fixation, all the implantation sites were similarly detectable. The mean area of implantation sites visibly increased after day 10. From all the results, the simple and accurate procedure including alkaline treatment was concluded to be useful for estimating implantation and pregnancy conditions in rabbits.

Animals↗
PubMed1993

Stable positively charged liposome during long-term storage.

The effect of taurine, as an isotonic solute, and of benzalkonium chloride (BZC), as a positive membrane component, on the long-term stability of liposomal suspensions was investigated by measuring surface potential. The surface potential, which introduced electrostatic repulsion to liposomes against aggregation, increased dose-dependently with the addition of BZC, which gave a positive charge. However, a further addition of BZC caused unexpected aggregation during storage, so the optimum addition of BZC was defined. On the other hand, taurine, which forms a zwitter ion in an aqueous solution, did not reduce the surface potential, suggesting that taurine is of possible utility as an isotonic solute. As the result of stability testing, the liposomal system using taurine and BZC was stable against aggregation during 6 months at 40 degrees C. We were successful in developing a stable, positively charged liposomal system during long-term storage, and our liposomal system is believed to be of wide utility as a drug carrier for therapeutic drugs applied topically to negatively charged mucosal tissues. We applied the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory to estimate the colloidal stability of liposomes. As a result of stability testing, positively charged liposomes had a good correlation between maximum total repulsive energy (VT(max)/kT) between two liposome particles and colloidal stability, suggesting that the VT(max)/kT value is useful for estimating stability and for designing liposomal preparations containing some ionic substances.

Benzalkonium Compounds↗
PubMed1993

Quantitative evaluation of the effectiveness of taurine in protecting the ocular surface against oxidant.

Quantitative evaluation of the effectiveness of taurine against ocular surface damage caused by hypochlorous acid (HOCl) was investigated using albino rabbits. The activity of lactate dehydrogenase (LDH) released from ocular tissues into meniscus tears at eye irritation was used as an index of ocular surface damage. Instead of collecting meniscus tears directly with a glass micropipette, a new sampling method, where 150 microliters of saline was instilled into the cul-de-sac of rabbit eyes and collected all of the diluted tears within 10 s, was developed. The LDH activity after serial instillations of HOCl increased dose-dependently with increasing HOCl concentration. After serial instillation of taurine, HOCl was instilled in the same way. Pre-application of taurine effectively suppressed (p < 0.01, n = 11) the HOCl-induced LDH release as compared to saline, suggesting that the residual taurine in ocular surface tissues was still effective in protecting the tissues against HOCl by scavenging HOCl. LDH activity at 30 in after post-application of taurine was significantly lower (p < 0.01, n = 10) than that in the case of saline. This result indicates that taurine is effective in protecting the ocular surface after it has been attacked by HOCl. LDH activity in meniscus tears became a good index of quantitatively estimating ocular surface damage due to HOCl by devising the new sampling method. By using this method, we were able to prove objectively and quantitatively that taurine is effective in protecting the ocular surface against HOCl. It was suggested that taurine is clinically useful in the treatment of ocular surface damage caused by oxidants, such as HOCl.

Animals↗
PubMed1992

A flow cytometric DNA analysis of giant cell tumors of bone including two cases with malignant transformation.

BACKGROUND AND METHODS: Flow cytometric DNA analysis was performed on 30 cases of giant cell tumor (GCT) of bone with the use of paraffin-embedded sections. RESULTS: According to the criteria of Huvos, they were classified histologically into three groups: Grade 1, 26 cases; Grade 2, 4 cases; and Grade 3, no cases. Among the Grade 1 cases, 21 were diploid and 5 were aneuploid. Of the four Grade 2 cases, three were diploid and one was aneuploid. Nine patients had local relapses. Among four patients with complications by lung metastases, two have remained well at 18 and 157 months with the metastases. The other two patients, who had Grade 1 DNA diploid GCT of the 11th thoracic spine, had malignant transformation (osteosarcoma) resulting from radiation therapy. In one patient, the primary lesion exposed to radiation and the lung lesions were diploid, but in the other patient both were found to be aneuploid at autopsy. No significant differences of S-phase fraction were observed between two different grade groups. There was no significant correlation among DNA ploidy, histologic grade, and the presence or absence of lung metastases. CONCLUSIONS: Based on this study, the DNA analysis has a limitation in predicting the biologic behavior of GCT.

Adolescent↗