[Photodynamic therapy for gastric cancer]

In this article, we first present our clinical data on PDT for the treatment of gastric cancer and make a comparison between a continuous wave laser and a pulsed laser. The reasons for PDT failure in certain cases are also discussed. In the fifteen years from 1981 to 1995, we have treated a total of 76 gastric cancer lesions (73 cases), which was consist of 69 early gastric cancer lesions (66 cases) and seven advanced gastric cancer lesions (seven cases) by PDT. From 1981 to 1990, we used an argon dye laser (ADL, Models 171-08 and 375-03, Spectra-Physics, Mountain View, Calif., US) as an excitation light source for PDT with HpD (Photofrin I), DHE (Photofrin II) or PHE (freeze-dried Photofrin II). From analysis of the results in terms of the depth of cancer invasion in these 44 lesions (41 cases), the rate of cure for mucosal carcinomas was 57% (13/23), that of submucosal carcinomas was 53% (10/19), and that of carcinomas invading more than the muscularis propria was 0% (0/2). These data can be interpreted to indicate that the ADL laser beam could not penetrate and supply sufficient energy to activate HpD not only in the submoucosal layer but also in the mucosal layer. In 1990, therefore, we investigated an excimer dye laser (EDL, Hamamatsu Photonics, Hamamatsu, Japan), because its pulsed beam with extremely high peak power was expected to be more efficient at exciting HpD than continuous wave lasers such as ADL and high frequency pulsed lasers such as cooper vapor dye laser (Cu VDL). From 1990 to 1995, twenty-seven early gastric cancer lesions (27 cases) and five advanced gastric cancer lesions (five cases) were treated by PDT with EDL and PHE. Of these 32 lesions, the rate of cure for mucosal carcinomas was 100% (15/15), that of submucosal carcinomas was 75% (9/12), and that of carcinomas invading more than the muscularis propria was 20% (1/5). For the purpose of determining how much energy was required for a complete cure in early gastric cancer, and to compare the efficacy of ADL and EDL, the relation between the response (cure or no cure) and irradiated energy intensity (dose: J/cm 2) was evaluated by the depth of cancer invasion and kind of laser used in PDT. A smaller EDL dose was more effective than ADL in terms of photodynamic action.

Cooperative clinical trial of photodynamic therapy with photofrin II and excimer dye laser for early gastric cancer

BACKGROUND AND OBJECTIVE

Photodynamic therapy (PDT) is a recently developed endoscopic method for treating malignant tumors. For obtaining more photodynamic action with less thermal effect, we employed as the excitation light source for PDT an excimer dye laser, which is a pulsed laser with extremely high peak power, instead of an argon dye laser, which is a continuous wave laser and has been used conventionally.

STUDY DESIGN/MATERIALS AND METHODS

The effect of PDT using Photofrin II and the excimer dye laser was evaluated in 27 patients with early gastric cancer.

RESULTS

Complete responses (CR) were obtained in 88% of 24 assessable patients and the response rate was 100%. CR was observed in all cases of lesions of superficial depressed type without ulceration and/or with tumor diameter less than 2 cm. Regarding toxicity, mild cutaneous reaction and photosensitivity were seen and lasted several weeks. There were no serious abnormalities in laboratory tests.

CONCLUSION

We conclude that PDT is a promising modality for early gastric cancer.

Sarin poisoning in Matsumoto, Japan

A presumed terrorist attack with sarin occurred in a residential area of the city of Matsumoto, Japan, on June 27, 1994. About 600 residents and rescue staff were poisoned; 58 were admitted to hospitals, and 7 died. We examined clinical and laboratory findings of 264 people who sought treatment and the results of health examinations on 155 residents done 3 weeks after the poisoning. Findings for severely poisoned people were decreases in serum cholinesterase, acetylcholinesterase in erythrocytes, serum triglyceride, serum potassium and chloride; and increases in serum creatine kinase, leucocytes, and ketones in urine. Slight fever and epileptiform abnormalities on electroencephalogram were present for up to 30 days. Examination revealed no persisting abnormal physical findings in any individual. Acetylcholinesterase returned to normal within 3 months in all people examined. Although subclinical miosis and neuropathy were present 30 days after exposure, almost all symptoms of sarin exposure disappeared rapidly and left no sequelae in most people.

Identification of the yeast MCM3-related protein as a component of Xenopus DNA replication licensing factor

Replication licensing factor is thought to be involved in the strict control of the initiation of DNA replication in eukaryotes. We identified a 100 kDa protein as a candidate for the licensing factor in Xenopus egg extracts. This protein was required for replication; it bound to sperm DNA before the formation of nuclei and apparently dissociated from the nuclear DNA during the progression of replication without being transported into the nuclei. An immunologically homologous protein in HeLa cells behaved similarly to the Xenopus protein during the cell cycle. Cloning and sequencing of the cDNAs encoding the Xenopus and human proteins revealed that they are homologs of yeast Mcm3, a putative yeast DNA replication licensing factor.

A new type of defect in the gene for bilirubin uridine 5'-diphosphate-glucuronosyltransferase in a patient with Crigler-Najjar syndrome type I

Crigler-Najjar syndrome (CN) type I, which is characterized by the complete absence of bilirubin uridine 5'-diphosphate-glucuronosyltransferase (UGT) activity, is inherited as an autosomal recessive trait associated with unconjugated hyperbilirubinemia. Phenobarbital has no effect on the bilirubin concentration in the serum of patients with CN type I. Recently, cDNA for two human liver bilirubin UGT (UGT1A and UGT1D) were isolated, and their genetic organization was determined. The UGT1A (UGT1*1) and UGT1D (UGT1*4) genes each have a unique exon 1, whereas exons 2-5 are common to both genes. It has been predicted that some defect in the exons common to both genes is responsible for the absence of UGT1A and UGT1D activities in CN type I, and five cases with such a mutation have been reported. We describe here a new type of defect in the gene for bilirubin UGT in a patient with CN type I, namely, an abnormality in the exon 1 that is characteristic of the UGT1A gene. This mutation is a single nucleotide substitution, that is, C is changed to A at base position 840 in UGT1A cDNA, and this change results in a stop codon. Our patient is homozygous for the defect, and his nonconsanguineous parents and elder brother, who are clinically normal, are heterozygous for the defective allele. No mutation was detected in any exons of the UGT1D gene. Our results suggest that a homozygous nonsense or deletion mutation is detected not only in the exons common to UGT1A and UGT1D genes but also in unique exon 1 of UGT1A in CN type I.

Photodynamic therapy for cancers: a clinical trial of porfimer sodium in Japan

Photodynamic therapy utilizing Photofrin has proven to be an effective modality that can be used in the treatment of a wide variety of solid tumors and luminal cancers. An argon pumped dye laser or excimer dye laser was used to deliver 630 nm light via quartz fibers passed through the biopsy channel subsequent to i.v. injection of photosensitizer. In this study, 64 patients with superficial cancers were treated in this manner but only 58 patients, including 21 with roentgenographically occult lung cancer, 8 with stage I lung cancer, 5 with esophageal cancer, 12 with gastric cancer, 8 with cervical cancer and 4 with bladder cancer were evaluable. Complete remission was obtained in 48 out of 58 cases (82.8%). There was no serious complication except skin photosensitivity, which was seen in 13 patients. We conclude that photodynamic therapy is efficacious in the treatment of superficial cancers where complete remission may be achieved.

Protection by L-ascorbic acid against phototoxicity in tin-protoporphyrin-treated suckling rats

The protective effect of free radical scavengers against phototoxicity was investigated with tin-protoporphyrin (SnPP)-treated suckling rats. Six kinds of scavengers (L-ascorbic acid, reduced glutathione, alpha-tocopherol, retinol, uric acid and cystine) were intraperitoneally injected to rats treated with SnPP plus photoirradiation. Among them, L-ascorbic acid was found to be most effective in protecting SnPP-treated rats against phototoxicity. The survival period was markedly prolonged, and the frequency of abnormal behaviors was reduced with the treatment. Lipid peroxidation in vitro with the brain membrane fraction was also suppressed. The other five substances gave only a little antioxidant effect both in vivo and in vitro. The present study shows that L-ascorbic acid may be a promising chemical to prevent the phototoxicity of SnPP.

Cobalt-mesoporphyrin inhibits heme oxygenase activity but it does not induce lipid peroxidation in rat brain membranes during photoirradiation

We examined the effects of cobalt-mesoporphyrin (CoMP) in vitro. The porphyrin inhibited the activity of rat splenic heme oxygenase but scarcely stimulated peroxidation of lipids in a membrane fraction from rat brain during photoirradiation. The apparent inhibition constant for CoMP was 344 nM. It is suggested that CoMP may be a promising candidate for a chemopreventive of neonatal hyperbilirubinemia that is not associated with phototoxicity.

Report of a study using phantom materials, and clinical experience with simultaneous radio-hyperthermotherapy

Simultaneous radiohyperthermotherapy (SRH) is a combined hyperthermia-radiation therapy in which irradiation is given during heating. Mutual interference between the high energy radiotherapy system (Toshiba LMR-15A) and the 13.56 MHz capacitive heating system (Omron HEH-500C) was tested with phantom materials prior to a clinical trial with SRH. The energy and flatness of irradiation were not affected by the heating system within the range of clinical use. The high energy radiotherapy system did not affect the increase or distribution of temperature during simultaneous treatment. The results of this phantom study indicated that these apparatuses would not produce clinically significant mutual interference during SRH. A clinical trial was performed on a 57-year-old woman with postoperative recurrence of rectal cancer. This is the first reported clinical case treated with true SRH in which external irradiation was administered during mid capacitive heating. Twelve SRH treatments were performed on the recurrent lesion at a frequency of twice a week for six weeks using the apparatuses described above. There was a significant reduction in pain after treatment. The tumor marker carcinoembryonic antigen (CEA) level decreased after treatment. On CT images taken after treatment, the tumor site became a low density area which indicated necrosis. There were no side effects. These results suggest that further clinical study of SRH should be performed to clarify its advantages.

Sn-protoporphyrin plus photoirradiation induces lipid peroxidation in vivo and in vitro in nonjaundiced Gunn rats

Lipid peroxidation induced by Sn-protoporphyrin (SnPP) plus photoirradiation was investigated in vivo and in vitro using nonjaundiced Gunn rats. Membrane lipids from young adult rat brain were peroxidized by SnPP plus photoirradiation depending on the SnPP concentration and photoirradiance. Similarly, coadministration of SnPP and photoirradiation to suckling rats increased lipid peroxides in the whole blood and was found lethal. The influence of the wavelength distribution of light sources was also examined by using blue-white and green fluorescent lights. The photodynamic effect by green light irradiation whose energy distribution had no overlap with the Soret band of SnPP was about half of that produced by blue-white light with regard to the membrane peroxidation and the lethal effect on neonatal rats. We therefore conclude that the combination of SnPP and photoirradiation is a potentially hazardous treatment of neonatal jaundice.

[Photodynamic therapy in the early treatment of cancer]

The clinical application of photodynamic therapy (PDT) began in the late 1970's. Hematoporphyrin derivative has been used as a photosensitizer and recently Photofrin II (Dihematoporphyrin ether, DHE) was also developed as a second generation photosensitizer. The argon dye laseris used to excite the photosensitizer, however an eximer dye laser was recently developed as more effective laser. In a multicenter research study project team (7 institutions) on photodynamic therapy organized by the Ministry of Health and Welfare, 133 cases of gastric cancer (including 120 cases of early stage cancer), 209 cases of lung cancer (69 cases of early stage cancer), 66 cases of esophageal cancer (22 cases of early stage cancer), 68 cases of bladder cancer (68 cases of early stage cancer), and 86 cases of other organ cancers were treated. In early stage cancer cases 77.3% showed complete remission (CR) but among those the recurrence was 15.7% in lung cancer cases and opposed to 100% CR and 22.2% recurrence in gastric cancer cases, 80% CR and no recurrence in esophageal cancer cases, and 68.6% CR and 58.3% recurrence in bladder cancer cases. Especially in limited lesions less than 1 cm in diameter, the CR was obtained in 100% and the recurrence was recognized in only 1 (2.6%) of 28 lung cancer lesions, 100% CR and no recurrence was obtained in 30 lesions of gastric cancer and also 100% CR with no recurrence was recognized in 16 lesions in bladder cancer. This study suggests that PDT has the potential to cure early stage cancer lesions.

Dangerous effects of tin-protoporphyrin plus photoirradiation on neonatal rats

In vivo and in vitro effects of porphyrins (tin-protoporphyrin [SnPP], cobalt-mesoporphyrin, haemin and protoporphyrin) on neonatal rats were investigated. Under photoirradiation a high mortality rate was recognized in SnPP injected rats. None died from the application of SnPP without photoirradiation. In photoirradiated rats the median lethal dose (LD50) value of SnPP was calculated to be about 7.4 mumol/kg body weight. Haemolysis and malonaldehyde formation of red blood cells were induced by SnPP together with photoirradiation. SnPP may be useful in reducing bilirubin levels in severely jaundiced infants under non-photoirradiated conditions or dim light, but prophylactic administration of SnPP to the majority of infants is not recommended.

Improvement of speech sound disorder with figure deformation case to a bone-defected patient

This report describes improvement of pronuciation in a bone-defected patient with a partial denture. The patient's chief complaints were difficulty of fricative and africative consonant utterance. Insertion of partial denture improved the pronunciation to some degree. Furthermore, the patient's figure deformation was corrected.

[Acoustic investigation of various palatal rugae]

We use some palatal plates with some Kinds of palatal rugae; ready made, patterned, individually copied and omitted, and studied the influence of the pronunciation acoustically concerning the Formant Frequency.

An acoustic investigation caused by pontic formation

Prosthetics for cases with large defects of alveolar bone often tend to be difficult. We researched the acoustic effects of various pontic forms to satisfy a patient's expectations for both phonetics and aesthetics.

[Indications for and limitations of HpD photodynamic therapy for esophageal cancer and gastric cancer]

HpD photodynamic therapy (PDT) was performed on 4 patients with superficial esophageal cancer, 20 patients with 22 early gastric cancer lesions and one patient with advanced gastric cancer. About 50 h before irradiation, 3 mg/kg of HpD or 1.3-2.5 mg/kg of Photofrin II was injected intravenously. The entire lesion including a 5-mm border of normal surrounding mucosa, was irradiated with an argon dye laser at 630nm wavelength with an output of 100-400mW at the tip of the fiber. Complete response (CR) to HpD-PDT was obtained in 2 of 2 mucosal esophageal cancers, and one of 2 submucosal lesions, totalling 3 of 4, and in 13 of 13 mucosal gastric cancers and 7 of 9 submucosal lesions totalling 20 of 22. The depths of cancer involvement were determined endoscopically. In Borrmann 1 lesion with muscularis externa involvement, in spite of two trials with HpD-PDT, only partial response (PR) was obtained. Tumor laser dose had to be more than 90 J/cm2, and in several cases combined hot biopsy with electrodiathermy and/or repeated HpD-PDT was needed to obtain CR. HpD-PDT is indicated for superficial esophageal cancer and depressed and/or assembled protuberant-type of early gastric cancer with poor risk.

Transplacental passage of digoxin in the case of nonimmune hydrops fetalis

Successful treatment of intrauterine fetal tachyarrhythmia was reported in several cases recently. It was also pointed out that placental transfer of digoxin is unsatisfactory under certain conditions. However, it has not been clearly shown in which cases fetal digoxin level does not reach the maternal level. We present a case of nonimmune hydrops fetalis due to congenital atrial flutter in which digoxin concentration in the sera of the mother and the neonate showed significant dissociation, and discuss perinatological matters about the digoxin treatment and the factor that obstructs the transplacental passage of digoxin. Conclusively, we recommend that maternal digoxin concentration should be raised to near toxic level if the resolution of fetal and placental hydrops is not attained in the initial digoxin loading.

[A case of oral florid papillomatosis combined with gastroduodenal polyposis]

A 49-year-old man developing numerous papillary or partly cauliflower-like tumors over the lips, oral angles, gingiva and tongue starting 15 years earlier and associated with multiple gastroduodenal polyps of various sizes revealed by X-ray examination is presented. Histologically, the oral lesions consisted of marked proliferation of mature squamous cells without appreciable cellular atypism or submucosal invasion. Electron microscopic study failed to detect any virus-like particles, and negative reaction was obtained in immunohistological study for papilloma virus. The association of gastroduodenal polyposis with oral florid papillomatosis has appeared very rarely in the literature. Although the relationship between the two lesions remains unknown, it was assumed in the present case that all lesions would represent an entity of a hamartomatous nature.