Purification and properties of fMet-tRNAf deacylase from Escherichia coli.

A formylmethionyl-tRNAf deacylase has been purified about 330-fold from a crude initiation factor preparation (1 M NH4Cl ribosomal wash) from Escherichia coli Q13. The enzyme was nearly homogeneous and had an apparent molecular weight of 24 000. Rat liver methionyl-tRNAf and E. coli methionyl-tRNAm were not hydrolyzed significantly by the enzyme under standard conditions. Q beta RNA- and AUG(A)n-directed polypeptide synthesis was inhibited by the enzyme. The inhibition was at the level of initiation of polypeptide synthesis. The enzymatic activity was inhibited by various factors necessary for polypeptide synthesis. The activity was inhibited more by NH4Cl and spermidine than by Mg2+, GTP and ATP. The complex of formylmethionyl-tRNAf, initiation factor 2 and GTP was resistant to enzymatic hydrolysis, and the resistance was enhanced by the addition of AUG and ribosomes to the above reaction mixture.

Pagetoid premalignant melanosis and melanoma: differentiation from Hutchinson's melanotic freckle.

Twenty-three examples of pagetoid premalignant melanosis have been analyzed by clinical, histologic, histochemical, and microscopic techniques. Utilizing criteria based on these findings, the pagetoid lesions can be differentiated from Hutchinson's melanotic freckel and seem to be particular types of nevocytic pigment cell tumors.

Lead contact lens for crystalline lens shielding in electron therapy for eyelid tumors.

In radiotherapy for eyelid tumors, a sufficient dose is required in the target tissue while preserving the crystalline lens. A I-mm thick, 20-mm diameter lead contact lens was prepared for crystalline lens protection. The lens was coated with an acrylic polymer and weighted 5.5 g. Six MeV electron therapy was scheduled using a 10 mm bolus on the eyelid. A simulation experiment proved that 0.78 +/- 0.04 percent of the maximal eyelid dose was given at the crystalline lens portion. A total of 14 eyelids in eight patients with cutaneous lymphoma, angiosarcoma, or basal cell carcinoma were treated with the contact lens. No cataract was found after irradiation over an average period of 24.3 months. The combination of the lead contact lens, bolus, and 6 MeV electron beam was a simple procedure and provided adequate dose distribution in the treatment of various eyelid tumors.

T1 and T2 lip cancer: a superselective method of facial arterial infusion therapy--preliminary experience.

PURPOSE: To formulate and evaluate a facial arterial infusion chemotherapy for squamous cell lip carcinoma. MATERIALS AND METHODS: The study included six patients (age range, 46-84 years) with squamous cell carcinoma of the lower lip. There were two T1 tumors, three T2 tumors, and one T1-compatible postoperative recurrent tumor. A 4-F, double-lumen balloon catheter was inserted into the external carotid artery through the superficial temporal artery and placed for selective infusion into the tumor-feeding facial artery. Patients received a combination of mitomycin C (4.4 mg/m2 per body surface area) on day 1 and 3.2 mg/m2 of peplomycin sulfate on days 1-7 (22.4 mg/m2 per week), or, when peplomycin sulfate was contraindicated, 16 mg/m2 of cisplatin only on days 1-5 (80 mg/m2 per week). Two to three cycles of chemotherapy were given until tumor disappearance was histologically confirmed. RESULTS: Complete tumor disappearance was achieved in all cases. One patient had a self-limiting asthma attack during peplomycin sulfate treatment, and another had transient partial hair loss. No disfigurement, recurrence, or late complications were observed at a mean follow-up of 5.0 years (range, 2.3-11.2 years). CONCLUSION: The described facial arterial infusion chemotherapy appears to be a safe and curative treatment for T1 and T2 squamous cell lip carcinomas.

Beneficial effect of Helicobacter pylori eradication in dermatologic diseases.

BACKGROUND: A relationship between skin diseases, particularly rosacea and chronic urticaria, and H. pylori infection has been suggested. METHODS: We preformed a prospective evaluation of the effect of H. pylori eradication in patients with a variety of chronic skin diseases. Patients were followed monthly for at least one year after cure of the infection. The effect of therapy was scored using a three point scale: complete remission (> 90% improvement), partial remission (50-90% improvement) or no improvement (< 50 improvement). The relationship between response and anti-H. pylori Ig G and E to specific H. pylori antigens was analyzed by Western blot analysis. RESULTS: Eighty-eight H. pylori-infected patients with skin disease were enrolled. Treatment was successful in 73% of patients with chronic urticaria as 23% (6 of 26) had complete and 50% had partial remission. Sixty-two percent (18 of 29) with pruritus cutaneus had partial remission as well as 30% with prurigo chronica multiformis had complete remission. Western blotting was done on 24 patients with skin disease and a 44K H. pylori antigen was detected by Ig E analysis in 100% (5 of 5) patients with complete remission compared to 23% (3 of 13) in those without skin disease. CONCLUSIONS: These results suggest it may be prudent to test patients with chronic urticaria, prurigo chronica multiformis, pruritus cutaneus, and eczema nummulare for H. pylori infection and to eradicate the infection in those whose test is positive.