Mutational effects of γ-rays and carbon ion beams on Arabidopsis seedlings

To assess the mutational effects of radiation on vigorously proliferating plant tissue, the mutation spectrum was analyzed with Arabidopsis seedlings using the plasmid-rescue method. Transgenic plants containing the Escherichia coli rpsL gene were irradiated with γ-rays and carbon ion beams (320-MeV ¹²C⁶⁺), and mutations in the rpsL gene were analyzed. Mutant frequency increased significantly following irradiation by γ-rays, but not by 320-MeV ¹²C⁶⁺. Mutation spectra showed that both radiations increased the frequency of frameshifts and other mutations, including deletions and insertions, but only γ-rays increased the frequency of total base substitutions. These results suggest that the type of DNA lesions which cause base substitutions were less often induced by 320-MeV ¹²C⁶⁺ than by γ-rays in Arabidopsis seedlings. Furthermore, γ-rays never increased the frequencies of G:C to T:A or A:T to C:G transversions, which are caused by oxidized guanine; 320-MeV ¹²C⁶⁺, however, produced a slight increase in both transversions. Instead, γ-rays produced a significant increase in the frequency of G:C to A:T transitions. These results suggest that 8-oxoguanine has little effect on mutagenesis in Arabidopsis cells.     

Successful differentiation of herpes zoster‐associated erythema multiforme from generalized extension of herpes by rapid polymerase chain reaction analysis

The polymerase chain reaction (PCR) assay for varicella zoster virus (VZV), herpes simplex virus (HSV)‐1 and HSV‐2 is available for use. Sometimes the differential diagnosis of the generalized herpes zoster (HZ), HSV1/2, and drug eruption is difficult. We report a case of HZ followed by the vesicular erythema multiforme (EM)‐like lesion. In this case the use of PCR was of great assistance. A 78‐year‐old Japanese man without any significant previous history of disease was admitted to our hospital complaining of zosteriform vesicle on an erythematous base from his right shoulder to the upper arm. We diagnosed him with HZ at the level of right Th2. In spite of the prompt start of antiviral therapy, a secondary new vesiculous erythema developed on his trunk. Clinically, it was quite difficult to differentiate the lesion from the generalized HZ. Rapid PCR assay of effusion and crust for VZV was performed. A PCR assay of VZV was positive for the crust taken from the primary lesion, while it was negative for the effusion and crust of the secondary widespread lesion. We diagnosed the secondary widespread lesion as an EM‐type drug eruption induced by acyclovir, or an EM associated with herpes zoster. We then stopped the use of acyclovir and applied steroid ointment of a very strong class for the secondary lesions, which improved after a few days. A PCR assay for VZV was useful for ruling out the generalized HZ in our case with secondary developed vesiculous lesions.     

SLOW GROWING FLAT‐TYPE PRIMARY MALIGNANT MELANOMA OF THE ESOPHAGUS TREATED WITH CAP‐ASSISTED EMR

We report a rare case of flat‐type primary malignant melanoma of the esophagus treated with endoscopic mucosal resection (EMR). A 64‐year‐old woman was referred for examination of a small pigmented lesion located in the mid esophagus. On endoscopy, the lesion exhibited almost no change in size over the year. Cap‐assisted EMR was performed en bloc. The histopathological findings showed atypical melanocyte proliferation in the basal layer, spindle cells, and epithelioid cell proliferation with nuclear enlargement and a few mitotic figures. Histopathological examination confirmed the diagnosis of primary malignant melanoma. Immunostaining for S‐100 protein and HMB‐45 antibody were positive, and the Ki‐67 index was low. The patient was discharged without additional surgical resection and/or chemotherapy. The patient had no symptoms and no signs of recurrence 20 months after EMR. There has been no report on a slow growing esophageal melanoma. It is difficult to estimate the malignant behavior of this case.     

Comparison of endoscopic findings with symptom assessment systems (FSSG and QUEST) for gastroesophageal reflux disease in Japanese centres

Background and Aim: We compared endoscopic findings of the frequency scale for the symptoms of gastroesophageal reflux disease (FSSG), a written questionnaire developed in Japan, to that for the questionnaire for the diagnosis of reflux esophagitis (QUEST) for the diagnosis of reflux esophagitis. Methods: We registered 475 patients with untreated symptoms of upper abdominal pain (male/female: 252/223, average age 52.4 ± 17.8 years). Subjects were assessed first with the FSSG and QUEST questionnaires, then by endoscopy, before allocation to a gastric ulcer (GU), duodenal ulcer (DU), gastroesophageal reflux disease (GERD) or functional dyspepsia (FD) group. Results: On the basis of the endoscopic findings the diagnoses for the 475 subjects were as follows: FD 52.2%, DU 7.6%, GU 7.8%, and GERD 32.4% (Grade M 10.1%, Grade A + B 20.2%, Grade C + D 2.3%). There was no difference between the FSSG and QUEST in sensitivity, specificity or accuracy for any condition. The FSSG score rose with increasing endoscopic severity of GERD, but there was no correlation between the QUEST score and endoscopic severity. The FSSG total score was inferior to QUEST in terms of distinguishing GERD from other conditions, but when only the questions relating to reflux symptoms were used, the FSSG was able to distinguish GERD from other conditions as well as QUEST. Conclusions: The FSSG score reflects the severity of the endoscopic findings of GERD.