Biodegradation of carbonate apatite/collagen composite membrane and its controlled release of carbonate apatite.

The aim of this study was to investigate the biodegradation of carbonate apatite (CO(3)Ap)/collagen composite membrane as a new guided tissue regeneration membrane in vivo and to estimate its controlled release of CO(3)Ap in vitro. To control the biodegradation of the guided tissue regeneration membrane and to promote hard tissue regeneration in the periodontal region, we added CO(3)Ap into the collagen membrane. To investigate the biodegradation of CO(3)Ap/collagen composite membranes, the prepared membranes (CO(3)Ap:0, 10 wt %) were cut into 5 x 5 x 0.1 mm and subcutaneously implanted into the backside of male rats under general anesthesia. The explanted membranes were investigated histologically. To estimate their controlled release of CO(3)Ap in vitro, the membranes (CO(3)Ap 0-10 wt %, 5 x 5 x 0.1 mm) were immersed into collagenase solution and compulsorily dissolved for 48 h. Histological results suggested that the membrane had a good biocompatibility and the biodegradable period was shortened with the presence of CO(3)Ap. In the solubility experiments of the membrane, eluted Ca concentrations gradually increased with total dependence on the dissolution of the collagen membrane. Our study demonstrated that the biodegradation time can be controlled by CO(3)Ap contents in the membrane and CO(3)Ap could be released from the membrane with the biodegradation period.

Squamous cell carcinoma of the maxillary sinus treated with radiation therapy and conservative surgery.

BACKGROUND: For patients with squamous cell carcinoma of the maxillary sinus, combined modality treatment is usually employed, involving radiation and en bloc radical surgery. In this study, local control was analyzed retrospectively in patients who underwent less aggressive piecemeal surgery. METHODS: Of the 37 patients irradiated between 1973 and 1992, 62% were classified as having T4 lesions. Thirty-two patients underwent surgery and radiation therapy; conventional fractionation radiation therapy was used in most cases. Thirty of these patients underwent piecemeal debulking of their tumors and simultaneous radiation therapy. RESULTS: Local recurrence free survival at 5 years was 59%, and orbital exenteration was performed on only 1 patient. T classification, the number of operations, and the presence of macroscopic residual disease each had a statistically significant impact on local recurrence. For the patients with macroscopic residual disease, more than 58 gray administered in conventional fractionation appeared to be necessary to improve local control. CONCLUSIONS: Combined with radiation therapy, conservative surgery with piecemeal debulking was an effective method of treatment for the patients in this study.

Local control of piriform sinus cancer treated by radiation therapy alone.

Local control rate by radical radiation therapy was analyzed in 33 patients with a piriform sinus cancer. Twenty-five patients (76%) were in stage T3 + T4. Local recurrence-free survival at 3 years was 49% in T1 + T2 and 25% in T3 + T4 (p = 0.01). In T1 + T2 lesions, a biologically effective dose for an acute reaction over 80 Gy and total treatment time less than 70 days appeared to improve local control. In T3 + T4 lesions, good radiation response assessed by the regaining of laryngeal mobility affected local control favorably. An esophageal involvement and destruction of the laryngeal cartilage as well as soft tissue extension precluded the possibility of local control by radiation therapy alone. In addition to the T-stage, other tumor factors should also be considered for predicting local control with radiation therapy.

Studies on yellow fever vaccine. III--Dose response in volunteers.

Standard and stabilized yellow fever (YF) vaccines were compared on the basis of the serological responses of human volunteers to varying doses of vaccine measured as pfu or LD50. The addition of stabilizer substances to bulk vaccine did not affect the immunogenicity and stabilized vaccine gave a consistently good performance. The vaccine fulfilled WHO recommendations in inducing 100% serological conversion in volunteers given about 200 pfu or 600 LD50.

[A case of complete remission following recurrent relapses 12 years after onset of acute myelocytic leukemia. Response to protocol including neocarzinostatin].

A 23-year-old male who had suffered recurrent relapses of acute myelocytic leukemia was treated with a protocol including neocarzinostatin (NCS) and complete remission was obtained. At the age of 11 years, he had complained of general fatigue and anemia, and was diagnosed as having AML because of the presence of leukemic cell infiltration in the bone marrow as well as peripheral blood. Auer bodies and a positive reaction to peroxidase were found. The last episode of relapse occurred at the age of 15 years, when he achieved complete remission following a trial protocol which included NCS. NCS seemed to be effective after it had been used intravenously for a short time. The patient has maintained complete remission for the past 7 years and has had no consolidation therapy in the last 3 years. For the last 18 months, he has been working in a market as a clerk 8 hours a day. NCS with a rapid infusion time seems to have effects on leukemic cells when it used with proteolytic enzyme. Neither skull radiation nor testicular biopsy were attempted. Results of CSF examination were within normal limits, but EEG and CT scan revealed the probability of early-stage leukoencephalopathy, although no significant clinical signs were observed. He had suffered an asthmatic attack before the onset of AML, but no further attack occurred until several months ago. In order to establish any relationship between these two diseases, further detailed analysis will be necessary.

Antineoplastic agents. 42. The butterfly, Prioneris thestylis.

Isoguanine (2) was found to be an antineoplastic constituent of Prioneris thestylis Dbldy. wings. Three other purine components of the butterfly wings were identified as hypoxanthine (3), uric acid (4) and xanthine (5). Isolation of urocanic acid (6) from the same wing material represented the first detection of this interesting histidine derivative in an arthropod.