Effect of Bioactive Primers on Bacterial-Induced Secondary Caries at the Tooth-Resin Interface.

Secondary caries at the tooth-resin interface is the primary reason for replacement of resin composite restorations. The tooth-resin interface is formed by the interlocking of resin material with hydroxyapatite crystals in enamel and collagen mesh structure in dentin. Efforts to strengthen the tooth-resin interface have identified chemical agents with dentin collagen cross-linking potential and antimicrobial activities. The purpose of the present study was to assess protective effects of bioactive primer against secondary caries development around enamel and dentin margins of class V restorations, using an in vitro bacterial caries model. Class V composite restorations were prepared on 60 bovine teeth (n=15) with pretreatment of the cavity walls with control buffer solution, an enriched fraction of grape seed extract (e-GSE), 1-ethyl-3-(3-dimethyl aminopropyl)-carbodiimide/N-hydroxysuccinimide, or chlorhexidine digluconate. After incubating specimens in a bacterial model with Streptococcus mutans for four days, dentin and enamel were assessed by fluorescence microscopy. Results revealed that only the naturally occurring product, e-GSE, significantly inhibited the development of secondary caries immediately adjacent to the dentin-resin interface, as indicated by the caries inhibition zone. No inhibitory effects were observed in enamel margins. The results suggest that the incorporation of e-GSE into components of the adhesive system may inhibit secondary caries and potentially contribute to the protection of highly vulnerable dentin-resin margins.

Personality, psychological stress, and self-reported influenza symptomatology.

BACKGROUND: Psychological stress and negative mood have been related to increased vulnerability to influenza-like illness (ILI). This prospective study re-evaluated the predictive value of perceived stress for self-reported ILI. We additionally explored the role of the negative affectivity and social inhibition traits. METHODS: In this study, 5,404 respondents from the general population were assessed in terms of perceived stress, personality, and control variables (vaccination, vitamin use, exercise, etc.). ILI were registered weekly using self-report measures during a follow-up period of four weeks. RESULTS: Multivariable logistic regression analysis on ILI was performed to test the predictive power of stress and personality. In this model, negative affectivity (OR = 1.05, p = 0.009), social inhibition (OR = 0.97, p = 0.011), and perceived stress (OR = 1.03, p = 0.048) predicted ILI reporting. Having a history of asthma (OR = 2.33, p = < 0.0001) was also associated with ILI reporting. Older age was associated with less self-reported ILI (OR = 0.98, P = 0.017). CONCLUSION: Elderly and socially inhibited persons tend to report less ILI as compared to their younger and less socially inhibited counterparts. In contrast, asthma, trait negative affectivity, and perceived stress were associated with higher self-report of ILI. Our results demonstrate the importance of including trait markers in future studies examining the relation between stress and self-report symptom measures.

Acetazolamide stress brain-perfusion SPECT predicts the need for carotid shunting during carotid endarterectomy.

UNLABELLED: Although carotid shunting is occasionally necessary to prevent cerebral ischemia during carotid endarterectomy, there is no reliable indication for this procedure. The purpose of this study was to evaluate whether acetazolamide stress brain-perfusion SPECT can predict the need for carotid shunting during carotid endarterectomy. METHODS: Basal and acetazolamide stress brain-perfusion SPECT imaging was performed using a 1-d protocol and 99mTc-ethylcysteinate dimer (ECD) in 75 patients (12 women, 63 men; mean age, 64.8 y) before carotid endarterectomy. The need for carotid shunting during carotid endarterectomy was determined by the development of neurologic deterioration after carotid clamping under regional anesthesia. Regional cerebral blood flow, cerebrovascular reserve, the presence of contralateral carotid stenosis (> or =70%), and clinical risk factors, including age, sex, history of minor stroke or transient ischemic attack, diabetes mellitus, hypertension, and smoking, were assessed with regard to whether they could predict the need for shunting. RESULTS: Carotid endarterectomy was performed safely without carotid shunting in 61 of 75 patients (81.3%). Carotid shunting was required in 14 patients (18.7%). Seven of 21 patients with a contralateral carotid stenosis, 9 of 41 with a reduced regional cerebral blood flow, and 11 of 30 with a reduced regional cerebrovascular reserve underwent carotid shunting. Patients with a reduced cerebrovascular reserve had a significantly higher number of carotid shunts performed (P < 0.01) than did those with a normal reserve, whereas contralateral carotid stenosis (P = 0.054) showed borderline significance. Reduced cerebral blood flow and clinical risk factors did not predict the need for carotid shunting (P > 0.1). Multiple logistic regression analysis showed that reduced cerebrovascular reserve was the only reliable predictor of the need for carotid shunting (P < 0.01). When a severely reduced cerebrovascular reserve (8/8) or reduced cerebral blood flow and cerebrovascular reserve with contralateral carotid stenosis (6/7) were present, carotid shunting was necessary, with positive and negative predictive values of 91% (10/11) and 94% (60/64), respectively. CONCLUSION: A reduced cerebrovascular reserve can predict the development of cerebral ischemia during carotid clamping. Acetazolamide stress brain-perfusion SPECT may be useful as a complementary method in determining selective carotid shunting during carotid endarterectomy.

Concurrent chemotherapy and radiotherapy in invasive cervical cancer patients with high risk factors.

The aim of this study was to evaluate the survival of 395 previously untreated cervical cancer patients with at least one high risk factor following concurrent chemoradiation and to assess the toxicities. Two different chemotherapy regimens were used for concurrent chemoradiation. In the patients with squamous cell carcinoma, 100 mg/m2 of cisplatin was infused intravenously, followed immediately by five consecutive daily administrations of 5-fluorouracil, 1,000 mg/m2/day, each infused intravenously over 24 hr. As for the patients with adenocarcinoma, 70 mg/m2 of cisplatin, 250 mg/m2 of cytoxan and 45 mg/m2 of adriamycin were administered intravenously on days 1, 2, and 3, respectively. The 5-year survival rate was 54.4% with stage III and IV, 62.6% with lymph node metastasis on computed tomogram or MRI, 77.9% with stage I-II disease with lesion size > or =4 cm, and 50.3% with small cell carcinoma or adenocarcinoma. Side effects from concurrent chemoradiation such as nausea, vomiting, and alopecia were present in all 395 cases. Anemia, leukopenia, thrombocytopenia, hepatotoxicity, and nephrotoxicity were observed to varying degrees, but there was no toxic death. This study suggests that cisplatin-based concurrent chemoradiation in treating cervical cancer patients with high risk factors is effective and relatively well tolerated, with acceptable toxicity.

Neoadjuvant chemotherapy and radiation for inoperable carcinoma of the maxillary antrum: a matched-control study.

A matched-control study comparing standard radiotherapy versus neoadjuvant chemotherapy and radiation was undertaken to clarify the effects of neoadjuvant systemic chemotherapy for locally advanced squamous cell carcinoma of the maxillary antrum. Thirty-four patients with inoperable maxillary cancer were treated with neoadjuvant chemotherapy and radiotherapy (Group II). Before starting radiotherapy, all patients in Group II received two or three cycles of neoadjuvant chemotherapy consisting of cisplatin and a 5-day continuous infusion of 5-fluorouracil with or without intravenous injection of vinblastine. Radiation doses ranged from 66 Gy to 75 Gy (median, 70 Gy). The response rate, patterns of failure, toxicity, and survival for Group II were compared with those for 34 stage-matched patients treated with radiation alone (Group I). Despite a higher response rate to neoadjuvant chemotherapy, the recurrence rate and patterns of treatment failure were not influenced by the addition of neoadjuvant chemotherapy. In most cases, neoadjuvant chemotherapy did not interfere with subsequent radiotherapy, and radiation-induced late complications occurred equally in both treatment groups. After a median follow-up of 48 months, there was no significant difference in 5-year actuarial survival or disease-free survival between the two treatment groups. Radiation alone for inoperable maxillary cancer was clearly suboptimal for improving local control and survival rate, but neoadjuvant chemotherapy in addition to standard radiotherapy failed to demonstrate any therapeutic advantage over radiation alone.

Combined transcatheter arterial chemoembolization and local radiotherapy of unresectable hepatocellular carcinoma.

PURPOSE: The best prognosis in hepatocellular carcinoma (HCC) can be achieved with surgical resection; however, the number of resected cases are limited due to advanced lesions or associated liver disease. The purpose of this study was to investigate the efficacy and toxicity of a prospective trial of combined transcatheter arterial chemoembolization (TACE) and local radiotherapy (RT) in unresectable HCC. METHODS AND MATERIALS: Patients with histologically proven unresectable HCC due to either advanced lesions or associated cirrhosis were eligible. From March 1992 to August 1994, 30 patients were entered into this study. TACE was performed with Lipiodol (5 ml) and doxorubicin (Adriamycin ; 50 mg), followed by gelatin sponge particle (Gelfoam) embolization. Local RT was started within 7-10 days following TACE. Mean tumor dose was 44.0+/-9.3 Gy in daily 1.8 Gy fractions. Response was assessed by computerized tomography (CT) scan 4-6 weeks following completion of the treatment and then at 1-3-month intervals. Survival was calculated from the start of TACE using the Kaplan-Meier method. RESULTS: An objective response was observed in 19 patients, giving a response rate of 63.3%. Distant metastasis occurred in 10 patients, with 8 in the lung only and 2 in both lung and bone. Survival rates at 1, 2, and 3 years were 67%, 33.3%, and 22.2%, respectively. Median survival was 17 months. There were 6 patients surviving more than 3 years. Toxicity included transient elevation of liver function tests in all patients, fever in 20, thrombocytopenia in 4, and nausea and vomiting in 1. There was no treatment-related death. CONCLUSION: Combined TACE and local RT is feasible and tolerable. It gives a 63.3% response rate with median survival of 17 months. We feel that this regimen would be a new promising modality in unresectable HCC. Further study is required to compare the therapeutic efficacy of this regimen to TACE alone.

Combined treatment of radiotherapy and hyperthermia for unresectable hepatocellular carcinoma.

Eighty-four patients with unresectable primary hepatocellular carcinoma due either to locally advanced lesion or to association with liver cirrhosis were treated with combined radiotherapy and hyperthermia from April 1988 to January 1991. Purpose of this study was to assess thermometry, response rate, toxicity, and survival in those patients. External radiotherapy was given with a total of 30.6 Gy/3.5 wks. Hyperthermia was given twice a week with a total of 6 treatment sessions using an 8 MHz radiofrequency capacitive type heating machine. Each hyperthermia session was started within 30 min following radiotherapy and continued for 30-60 min. Thermal data were analysed with maximum, minimum, and average temperatures of the tumors. Thermal mapping was also done. In thermometry results, maximum, minimum, and average temperatures of the tumors were 41.9 +/- 1.3 degrees C, 39.9 +/- 1.0 degrees C, and 40.8 +/- 0.9 degrees C, respectively. The fraction over 40 degrees C was 73 +/- 32% with a wide variation from 15% to 100%. Among 67 assessable patients, 27 patients showed tumor regression of more than 50% of the original tumor volume (40.3% response rate). Symptomatic improvement was observed in 78.6% of the patients. Acute toxicities during the treatment were mostly acceptable local pain (51.2%) and local fat necrosis (13.1%). The actuarial 1-year, 2-year, and 3-year survival rates were 44.8%, 19.7%, and 15.6%, respectively. Median survival was 6 months. In view of acceptable toxicities and the current rate of survival, further evaluation of combined treatment of radiotherapy and hyperthermia for unresectable hepatocellular carcinoma is warranted.

Combined chemotherapy and radiation for bulky stages I-II cervical cancer: comparison of concurrent and sequential regimens.

Based on analysis of 5-year survival rates among 386 patients with carcinoma of the cervix treated between 1976 and 1984 at Yonsei University College of Medicine, high risk factors have been defined which identify patients with a poor prognosis when treated with radiation alone. Among patients with FIGO Stages I-II disease, lesions > or = 4 cm were indicative of a higher risk of treatment failure. Between 1984 and 1991, 39 patients with Stages I-II large cell squamous cancers > or = 4 cm in diameter were treated with radiation alone. Between 1984 and 1989, 19 comparable patients were treated with sequential chemotherapy consisting of two or three cycles of cisplatin at 100 mg/m2 and a 5-day infusion of 5-fluorouracil at 1000 mg/m2/24 hr. Between 1988 and 1991, 37 comparable patients were treated with concurrent radiation and one to six cycles of chemotherapy employing the same or equivalent drug and dose schedule. The radiation techniques, dose, and fractionation employed were similar in the three groups. The 30-month survival rate was 100, 89.5, and 79.5% (P < 0.05) following concurrent treatment, sequential treatment, and radiation alone, respectively. Response to chemotherapy administered in cycles was evaluated before instituting radiotherapy in the patients treated with sequential chemotherapy and radiation. In conclusion, the combination of radiotherapy and chemotherapy appeared superior to radiation alone, and the toxicity of combined modality therapy is manageable. Also concurrent chemotherapy may be slightly better than sequential chemotherapy and radiation, and given the lesser overall treatment time and expense, this has become the preferred mode of treatment in our institution.

Phase II trial for combined external radiotherapy and hyperthermia for unresectable hepatoma.

Hepatocellular carcinoma is a major malignant disease in parts of Africa and Asia, including Korea. Surgical resection, which represents the best hope for cure, is limited by the extent of the disease and the high incidence of concurrent liver cirrhosis in Korea. We designed a phase II trial of combined external radiotherapy and hyperthermia for hepatocellular carcinoma that was unresectable due to either locally advanced lesions or associated liver cirrhosis so as to evaluate the efficacy and the safety of this combination regimen. This trial was performed at Yonsei Cancer Center between April 1988 and July 1988. External radiotherapy was delivered to a total dose of 3060 cGy/3.5 weeks. Hyperthermia was applied twice a week for a total of six treatment sessions using an 8-MHz radio-frequency capacitive-type heating device, i.e., Thermotron RF-8 and Cancermia. In all cases, hyperthermia was carried out within 30 min of the radiotherapy for a period of 30-60 min. The temperature in the tumor was measured by inserting a thermocouple into the tumor mass under ultrasonographic guidance in patients who did not have a bleeding tendency. The tumor response was assessed by CT scan after completion of the designed treatment. No complete response was obtained. However, a symptomatic improvement in abdominal pain was observed in 78.6% of cases and a partial response was achieved in 40% of the patients. The most important factor affecting the tumor response was the type of tumor (single massive, 71.4%; diffuse infiltrative, 20%; multinodular, 0; P < 0.005). The 1-year survival values determined for all patients and for the partial responders were 34% and 50%, respectively. The overall median duration of survival was 6.5 months. The median duration of survival for the partial responders was longer than that for the nonresponders (11 vs 5 months; P < 0.05). A mild degree of heat sensation, fever, first-degree burns of the skin, and nausea were observed as treatment-related adverse reactions. In conclusion, although this study is being continued, the results obtained thus for indicate that combined radiotherapy and hyperthermia seem to be effective in providing local tumor control and pain palliation in unresectable hepatocellular carcinoma while producing an acceptable level of toxicity.

Effects of amiloride on intracellular pH and thermosensitivity.

Amiloride, a diuretic drug, is a potent inhibitor of Na+/H+ exchange through the plasma membrane, and has been reported to enhance thermal damage in tumor cells in vitro. We investigated the possible relationship between changes in the thermal response of SCK mouse mammary tumor cells in vitro and changes in intracellular pH (pHi) due to amiloride in the present study. At a concentration of 0.5 mM, amiloride reduced the shoulder (Dq) without causing significant change in the slope (Do) of the survival curve of SCK cells heated once at 43 degrees C. On the other hand, 0.5 mM of amiloride sensitized thermotolerant cells to heat as shown by a reduction in Do. The presence of amiloride during the interval between the first and second heatings slightly reduced or inhibited the development of thermotolerance. The pHi was measured with the BCECF fluorescence method. The presence of 0.5 mM amiloride significantly reduced pHi in both pH 7.2 and 6.6 medium. Heating the SCK cells at 43 degrees C in pH 7.2 or 6.6 medium also reduced the pHi. The combined effect of heat and amiloride in reducing the pHi of SCK cells was additive. These results suggest that the effects of amiloride on the thermal response of SCK cells might be mediated in part by a decrease in pHi. The possibility that the effects of amiloride on the thermal response of tumor cells are mediated by other biochemical changes, such as inhibition of protein synthesis, however, could not be ruled out.

The influence of Fluosol-DA and carbogen breathing on the antitumor effects of cyclophosphamide in vivo.

The effects of Fluosol-DA, an oxygen-carrying perfluorochemical emulsion, and carbogen breathing alone or in combination on the antitumor activity of cyclophosphamide (CTX) in vivo were investigated. The addition of 12 ml/kg Fluosol-DA immediately prior to CTX treatment exerted no effect on the antitumor effect of CTX on the RIF-1 tumor in C3H mice. On the other hand, carbogen breathing alone for 8 h significantly enhanced the antitumor effect of CTX, with a dose-modification factor of 1.29 +/- 0.07. The combination of Fluosol-DA and carbogen breathing further increased the effect of CTX, with a dose-modification factor of 1.63 +/- 0.05. There was no significant difference in animal lethality within the treatment groups. It was concluded that Fluosol-DA in combination with carbogen breathing may be useful for the enhancement of CTX chemotherapy of human neoplasms.

Cooperative clinical studies of hyperthermia using a capacitive type heating device GHT-RF8(Greenytherm).

Yonsei Cancer Center developed an RF(Radiofrequency) capacitive type heating device, GHT-RF8(Greenytherm) in cooperation with Green Cross Medical Corp., Korea in 1986 for the first time in Korea. Cooperative clinical studies of hyperthermia for the treatment of cancer using GHT-RF8 were conducted by Yonsei Cancer Center in collaboration with the Presbyterian Medical Center, Chonju, Korea. A total of forty patients with various histologically proven malignant tumors, including superficial (N = 13) and deep-seated tumors (N = 27), were treated with this newly developed heating device in conjunction with radiotherapy (N = 38) or chemotherapy (N = 2) at two different institutes between October 1986 and September 1987. These patients were locally far advanced or recurrent cases and considered to be refractory to conventional cancer treatment modalities. Radiotherapy was given in 200cGy per day, five times a week fractionations with a total tumor dose of 50-60Gy in 5-6 weeks. Within an hour after radiotherapy, the RF capacitive type of hyperthermia was given two times a week for a total of 4-10 treatment sessions and an attempt was made to maintain the tumor temperature at 41-45 degrees C for 30-60 minutes. Of forty patients treated, 14 patients with deep-seated tumors showed complete response and 20 patients showed partial response. The overall response rate was 85% (34 out of 40 patients) and only 6 patients showed no response. Complications from this treatment were mainly burns, superficial first degree burn in 2 cases, second degree in 4 cases and subcutaneous fat necrosis was observed in 2 cases.(ABSTRACT TRUNCATED AT 250 WORDS)