Clinical and photobiological characteristics of xeroderma pigmentosum complementation group F: a review of cases from Japan

A 61-year-old female patient with xeroderma pigmentosum (XP), registered as XP46KO, was assigned to complementation group F by the cell fusion-complementation method. The XP46KO fibroblasts in culture exhibited a defective DNA repair capacity of 10-15% unscheduled DNA synthesis and a 3-fold sensitivity to the lethal effect of 254 nm ultraviolet light compared with normal cells. The patient had mild clinical symptoms consisting of numerous pigmented freckles and a small number of seborrheic keratosis-like papules. She had no skin cancers in the sun-exposed areas of the skin and so far no neurological abnormalities. A review of 11 Japanese group F patients revealed very mild skin symptoms with no ocular or neuro-psychiatric abnormalities. Single skin cancers occurred in only 3 of the 11 patients with an average age of 52 years for their first skin malignancy.

Effects of various drugs on bladder function in conscious rats

In the present study, we attempted to evaluate the effects of various intravenous administered drugs, which had been shown to influence bladder function in anesthetized animals, on the cystometrogram in conscious rats placed in a restraining cage. Thiopental, diazepam, baclofen, clonidine and flavoxate, considered to act on the micturition center in the brain stem, hardly increased bladder capacity (time to micturition in cystometrogram) in conscious rats, but morphine, indomethacin and lidocaine, considered to act on the micturition center in the sacral cord or bladder mechanoreceptors, increased it. In a chronic conscious rat, histopathological findings show that the bladder tissue at 2 days after implantation of the catheter to the bladder showed experimental cystitis characterized by severe edema in the submucosa and an increase in prostaglandin E2 content, which is thought to stimulate directly and/or indirectly the capsaicin-sensitive sensory fiber in the afferent branch of the micturition reflex, and there was hyperreflexia characterized by decreases in both bladder capacity and urine volume. In conclusion, cystometrography in conscious rats placed in a restraining cage is thought to be a useful model for evaluating the true effect of a newly developed agent on bladder function.

Sublethal and potentially lethal damage repair on thermal neutron capture therapy

Tonicity shock or caffeine postirradiation treatment makes evident fast-type potentially lethal damage (PLD). Caffeine expresses fast-type PLD more efficiently than tonicity shock in X-irradiated B-16 mouse melanoma cells, compared with V79 Chinese hamster cells. The survival curves of thermal neutrons for either V79 or B-16 cells exhibit no shoulder. Neither V79 nor B-16 cells show the sublethal damage (SLD) repair of thermal neutrons. Caffeine-sensitive fast-type PLD repairs exist in X-irradiated B-16 cells, as well as V79 cells. The fast-type PLD repair of B-16 cells exposed to thermal neutrons alone is rather less than that of X-irradiated cells. Furthermore, an extremely low level of fast-type PLD repair of B-16 cells with 10B1-paraboronophenylalanine (BPA) preincubation (20 hours) followed by thermal neutron irradiation indicated that 10B(n,alpha)7Li reaction effectively eradicates actively growing melanoma cells. The plateau-phase B-16 cells are well able to repair the slow-type PLD of X-rays. However, cells can not repair the slow-type PLD induced by thermal neutron irradiation with or without 10B1-BPA preincubation. These results suggest that thermal neutron capture therapy can effectively kill radioresistant melanoma cells in both proliferating and quiescent phases.

New thermal neutron capture therapy for malignant melanoma: melanogenesis-seeking 10B molecule-melanoma cell interaction from in vitro to first clinical trial

Human melanoma regression by single thermal neutron capture therapy (NCT) using melanoma-seeking 10B compounds has been achieved. Since 1972, the aim of my team has been to synthesize tumor-seeking 10B-compounds possessing selective affinity for specific metabolic activity of the target cancer cells. Once the melanoma takes up these 10B compounds, thermal neutrons, which cause insignificant cell damage, are easily absorbed by nonradioactive 10B, inducing the 10B(n, alpha)7Li reaction and releasing the high LET particles to 14 mu melanoma cell diameter, destroying the tumor without damaging surrounding tissue. Radiobiological and preclinical studies culminated in the first successful human NCT treatment, with no recurrence of the treated melanoma since July, 1987.

Relative biological effectiveness (RBE) of thermal neutron capture therapy of cultured B-16 melanoma cells preincubated with 10B-paraboronophenylalanine

An experimental study of the relative biological effectiveness (RBE) of thermal neutron capture therapy (TNCT) for melanoma cell inactivation using 10B1-paraboronophenylalanine (10B1-BPA) was carried out to demonstrate a high therapeutic effect of TNCT, compared with that of fast neutron. Cells preincubated with or without 10B1-BPA at a concentration of 50 micrograms/ml for 20 h were irradiated with 60Co gamma-ray, fast neutron or thermal neutron. The absorbed dose of the cells from thermal neutron was calculated by Kobayashi's model. The D0 value of fast neutron was 1.07 Gy, and the D0S of thermal neutron radiation with or without preincubation of the cells with 10B1-BPA were 0.46 Gy or 0.67 Gy, respectively. The RBEs of fast neutron, thermal neutron beams, and neutron capture therapy relative to 60Co gamma-ray were calculated as 2.78, 4.18, and 6.15 at 0.1 surviving fraction, respectively. These results indicate radiologically that thermal neutron capture therapy using 10B1-BPA is an excellent radiation therapy for malignant melanoma.

Specific killing of human melanoma cells with an efficient 10B-compound on monoclonal antibodies

We previously established methods which have enabled us to target a sufficient number of 10B atoms on human melanoma cells to destroy them by thermal neutron irradiation. Monoclonal antibodies were here used as vector of 10B atoms on the target cell. Thermal neutrons require at least 10(9) 10B atoms to destroy the cell. In order to accumulate an adequate number of 10B atoms on target cells, our first approach was to make an effective compound that contains 12 atoms of 10B in a molecule. The second step was to conjugate the compound with an avidin molecule (10B12-avidin). One molecule of the 10B12-avidin carries about 30 atoms of 10B. This 10B12-avidin can be specifically targeted on human melanoma cells by biotinated monoclonal antibodies specific for the cells. Furthermore, the number of 10B atoms on target cells can be augmented by a hapten-antihapten monoclonal antibody system. The cultured human melanoma cells treated with these methods were damaged by thermal neutron irradiation. This is the first study that indicates thermal neutrons do injure target cells boronated by monoclonal antibodies.

Morphological changes in human melanoma cells following irradiation with thermal neutrons

Morphological changes in two human melanoma cell lines, MM96 and MM418, following irradiation with thermal neutrons, were studied using light and electron microscopy. The results show that the response of human malignant melanoma cells to neutron irradiation is both cell line dependent and dose dependent, and that in any given cell line, some cells are more resistant to irradiation than others, thus demonstrating heterogeneity in respect to radiosensitivity. Cells repopulating MM96 flasks after irradiation were morphologically similar to the cells of origin whereas in MM418 flasks cells differentiated into five morphologically distinct subgroups and showed increased melanization. The results also show that radiation causes distinctive morphological patterns of damage although ultrastructural changes unique to the high LET particles released from boron 10 neutron capture are yet to be identified.

Review: biological effectiveness of thermal neutrons and 10B(n,alpha)7Li reaction on cultured cells

There are only a few reports on the relative biological effectiveness (RBE) of thermal neutrons and 10B(n,alpha)7Li reactions either in vitro or in vivo. The data in this paper summarize almost all previously published in vitro data. Because only a few reactors are available for biomedical purposes, it is difficult to make a comparison of data from experiments using the same kind of radiation, and also to make a comparison of data from experiments using the different kinds of radiations. However, it is indispensable for boron neutron capture therapy to make a radiobiological analysis. More intensive study, including repair process and oxygen effect, is necessary for establishing the fundamental basis of the clinical application of boron neutron capture therapy.

Estimation of absorbed dose in the covering skin of human melanoma treated by neutron capture therapy

A patient with malignant melanoma was treated by thermal neutron capture therapy using 10B-paraboronophenylalanine. The compound was injected subcutaneously into ten locations in the tumor-surrounding skin, and the patient was then irradiated with thermal neutrons from the Musashi Reactor at reactor power of 100 KW and neutron flux of 1.2 X 10(9) n/cm2/s. Total absorbed dose to the skin was 11.7-12.5 Gy in the radiation field. The dose equivalents of these doses were estimated as 21.5 and 24.4 Sv, respectively. Early skin reaction after irradiation was checked from day 1 to day 60. The maximum and mean skin scores were 2.0 and 1.5, respectively, and the therapy was safely completed as far as skin reaction was concerned. Some factors influencing the absorbed dose and dose equivalent to the skin are discussed.

Neutron irradiation of human melanoma cells

The biological characteristics and in vitro radiosensitivity of melanoma cells to thermal neutrons were investigated as a guide to the effectiveness of boron neutron capture therapy. Plateau phase cultures of three human malignant melanoma-established cell lines were examined for cell density at confluence, doubling time, cell cycle parameters, chromosome constitution, and melanin content. Cell survival dose-response curves, for cells preincubated in the presence or absence of p-boronophenylalanine. HCl (10B1-BPA), were measured over the dose range 0.6-8.0 Gy (N + gamma). The neutron fluence rate was 2.6 x 10(9) n/cm2/s and the total dose rate 3.7 Gy/h (31% gamma). Considerable differences were observed in the morphology and cellular properties of the cell lines. Two cell lines (96E and 96L) were amelanotic, and one was melanotic (418). An enhanced killing for neutron irradiation was found only for the melanotic cells after 20 h preincubation with 10 micrograms/ml 10B1-BPA. In view of the doubling times of the cell lines of about 23 h (96E and 96L) or of 36 h (418), it seems likely that an increased boron uptake, and hence increased radiosensitivity, might result if the preincubation period with 10B1-BPA is extended to several hours longer than the respective cell cycle times.

A trial to improve the analysis of boron in biological materials

For the spectrophotometric determination of boron in biological materials, two decomposition methods were used. One is the alkali fusion method, and the other is the acid decomposition method using a uniseal decomposition vessel. A long-range calibration curve for the former method was obtained by using an ultrapure sulfuric acid. The alkali fusion method was applied to samples into which paraboronophenylalanine (BPA) or its hydrochloric salt (BPA.HCl) had been injected. By the acid decomposition method using a uniseal vessel, 50 mg dried liver was digested by a mixed solution of 1 ml conc. sulfuric acid and 6 ml 30% hydrogen peroxide. A problem exists, however, in that the hydrogen peroxide remaining in the decomposition solution must be eliminated without loss of boron.

Treatment of malignant melanoma by selective thermal neutron capture therapy using melanoma-seeking compound

As pigment cells undergo melanoma genesis, accentuated melanogenesis concurrently occurs in principle. Subsequent to the understanding of intrinsic factors controlling both processes, we found our selective melanoma neutron capture therapy (NCT) using 10B-dopa (melanin substrate) analogue, 10B1-p-boronophenylalanine (10B1-BPA), followed by 10B(n, alpha)7Li reaction, induced by essentially harmless thermal neutrons, which releases energy of 2.33 MeV to 14 mu, the diameter of melanoma cells. In vitro/in vivo radiobiological analysis revealed the highly enhanced melanoma killing effect of 10B1-BPA. Chemical and prompt gamma ray spectrometry assays of 10B accumulated within melanoma cells after 10B1-BPA administration in vitro and in vivo show high affinity, e.g., 10B melanoma/blood ratio of 11.5. After successfully eradicating melanoma transplanted into hamsters with NCT, we advanced to preclinical studies using spontaneously occurring melanoma in Duroc pig skin. We cured three melanoma cases, 4.6 to 12 cm in diameter, by single neutron capture treatment. Complete disappearance of melanoma was obtained without substantial side effects. Acute and subacute toxicity as well as pharmacodynamics of 10B1-BPA have been studied in relation to therapeutic dosage requirements. Clinical radiation dosimetry using human phantom has been carried out. Further preclinical studies using human melanoma transplanted into nude mouse have been a useful model for obtaining optimal results for each melanoma type. We recently treated the first human melanoma patient with our NCT, using essentially the method for Duroc pig melanoma, and obtained similar regression time course leading to cure.

[Effects of (+/-)-4'-ethyl-2-methyl-3-(l-pyrrolidinyl) propiophenone hydrochloride (HY-770) on the bladder function]

The effects of HY-770 on micturition reflexes in rats, dogs and cats and urethral pressure in dogs were compared with those of flavoxate.HC1 (flavoxate), terodiline.HCl (terodiline) and oxybutynin.HCl (oxybutynin). 1) HY-770, in intravenous (2 and 4 mg/kg) and intraduodenal (12.5 and 25 mg/kg) administrations, dose-dependently abolished the rhythmic bladder contractions in anesthetized rats. The activity of HY-770, in intravenous administration (i.v.), was almost equal to those of flavoxate, terodiline and oxybutynin; and the activity of HY-770, like terodiline, was more potent than that of flavoxate in intraduodenal administration (i.d.). 2) In the cystometrograms, HY-770 (3, 4 or 8 mg/kg, i.v.) dose-dependently increased the time to micturition (capacity of bladder) without decreasing the amplitude of micturition contraction in anesthetized rats, dogs and cats, and HY-770 (25 mg/kg, i.d.) also increased the capacity in anesthetized cats. 3) HY-770 (4 and 8 mg/kg, i.v.) dose-dependently increased the capacity of the bladder in the cystometrograms of pollakiuria induced by either transection of both the hypogastric nerves or chronic cannulation to the bladder in anesthetized or conscious rats, respectively. 4) HY-770 (25 mg/kg, i.d.) slightly decreased the urethral pressure in anesthetized dogs. These results suggest that HY-770 is a promising drug for the treatment of pollakiuria induced by a neurogenic bladder or unstable bladder, etc.

Melanin monomers within coated vesicles and premelanosomes in melanin synthesizing cells

We have found substantial amounts (6.6-143 and 0.5-13 micrograms/mg. protein, respectively) of 5,6-dihydroxyindole (5,6-DHI) and 5,6-dihydroxyindole-2-carboxylic acid (5,6-DHI2C), which are key intermediate monomers for the formation of the eumelanin polymer, within coated vesicle fraction of pigment cells. In addition, the amounts of these eumelanin monomers have been found to decrease along with the process of eumelanin polymer formation from coated vesicles to premelanosomes and finally to melanosomes among melanogenic subcellular compartments. Our present findings seem to indicate that coated vesicles transfer not only highly glycosylated T1-tyrosinase but also eumelanin monomers into premelanosomes.

No apparent neurologic defect in a patient with xeroderma pigmentosum complementation group D

A 31-year-old female patient with xeroderma pigmentosum (XP) XP43KO was assigned to complementation group D by the cell-fusion complementation methods. Cultured XP43KO cells from our patient had the defective DNA repair phenotype showing a residual level of ultraviolet (UV)-induced unscheduled DNA synthesis (45% of normal) and an eightfold higher sensitivity to 254-nm UV killing, compared with normal cells. The phototest on the patient revealed the delayed maximum reaction to UV-B-induced erythema and lower minimal erythema doses at 290- and 300-nm monochromatic wavelengths. However, the XP43KO patient showed no apparent neurologic abnormalities and rather mild or moderate skin lesions at the age of 31 years, although DNA repair deficiency in XP43KO cells from our patient fell into the range of group D cells.

Comparative analysis of oncogene expression and chromosome abnormalities between metastatic and nonmetastatic B16 melanoma clones

We have established nonmetastatic mouse B16 melanoma clone, C1-2, and metastatic variant, C4-1, by subcloning the 30th passage of nonmetastatic W1-4 cells. We have investigated oncogene expression and chromosomal abnormalities to see whether there is some correlation with tumor progression and phenotypic diversification in melanoma cells. Not only metastatic C4-1 but also nonmetastatic C1-2 showed similarly high expression of c-Ha-ras and c-myc oncogenes by Northern blotting method. The chromosome numbers of both clones were distributed mainly within the range of 48-52. C1-2 had about 20 biarmed chromosomes and C4-1 had 13 or 14, which made real ploidy of C1-2 and C4-1, hypotetraploidy and triploidy, respectively. 21 marker chromosomes were commonly observed, while 9 marker chromosomes peculiar to C1-2 and 4 peculiar to C4-1 were constantly recognized. In partial accordance with a previous report, chromosomes 4, 5, 6, 8, 10, 13, 18, 19, and X were additionally observed in nonmetastatic C1-2 cells, compared with metastatic C4-1 cells. Furthermore, in our study, the increase of chromosomes 1, 15, and 16 was found to be greater in metastatic C4-1.

Cockayne syndrome: magnetic resonance images of the brain in a severe form with early onset

A 2-year-old boy with an early onset and severe form of Cockayne's syndrome (CS) showed differences from the common CS form, which made the clinical diagnosis difficult. However, the cellular characteristics of CS, that the patient's skin fibroblasts exhibited the hypersensitivity to the lethal effect of 254 nm ultraviolet light (UV) and a defective recovery of post-UV DNA synthesis, but normal level of UV-induced unscheduled DNA synthesis, were observed. The magnetic resonance imaging (MRI) by the inversion-recovery method of the brain at age of 26 months showed atrophy or poor development of high signal images of the white matter. The MRI spin-echo image showed a low signal image of the lenticular nucleus. The T1 and T2 values of the cerebrum (grey matter, white matter, lenticular nucleus and thalamus) were greater than those of the age-matched controls. but similar to infant brains with much free water. Such MRI findings may suggest hypomyelination leading to the severe atrophy of the brain in this CS patient. His severe symptoms progressed rapidly until his death at 35 months due to systemic sepsis and renal dysfunction. Autopsy revealed severe microcephaly, severe atrophy of cerebrum, cerebellum and brain stem, and calcification throughout the brain, especially in the basal ganglia. Myelin staining showed numerous patchy losses of myelination in the cortical white matter.