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The biosynthetic pathway of phenolics with an acetylenic group, 4-[5-(4-methoxyphenoxy)-3-penten-1-ynyl]phenol (1) and its related compounds, isolated from suspension-cultured cells of Asparagus officinalis L. (Liliaceae), was studied in feeding experiments using [1-13C]- and [U-13C] glucose. Analyses of the 13C-NMR spectra of the methyl ether and acetate of the 13C-labelled species of 1 indicated that the aromatic rings at both ends of the molecule are formed from shikimic acid. It was also assumed that the acetylenic carbons in the C5 chain could be incorporated together with its adjacent aromatic ring through any phenethyl class compound derived from phenylpropanoids, and the propenylene carbon through glycolysis metabolites with C3 carbon units.

The purpose of the present investigation was to determine whether calbindin-D28k and parvalbumin are distributed to different subpopulations of somatic and visceral sensory neurons. Immunofluorescent and retrograde techniques were combined to examine the distribution of calbindin- and parvalbumin-like immunoreactivity in the cell bodies of somatic and visceral primary afferent neurons in dorsal root ganglia L1-S1 of rats. Calbindin and parvalbumin were differentially distributed to essentially non-overlapping subpopulations of primary sensory neurons that could be distinguished by their segmental and size distributions, as well as by their innervation of somatic and visceral structures. Calbindin-like immunoreactivity was found in a population of smaller-sized cell bodies comprising approximately 14%of all dorsal root ganglion cells examined, with the proportions being greatest in L6 and S1. In contrast, parvalbumin was found in a population of larger-sized cells that made up about 11% of dorsal root ganglion cells and that were most concentrated in L4 and L5. Sensory neurons were further characterized by retrograde transport following the application of the neuroanatomical tracer FluoroGold to somatic (sural and gastrocnemius) and visceral (hypogastric and pelvic) nerves. Somatic tissues were innervated by a population of calbindin-containing as well as a separate population of parvalbumin-containing sensory neurons. In contrast, afferent neurons innervating visceral structures contained only a subpopulation of calbindin-containing neurons and very few parvalbumin-positive cells.

Immunofluorescent techniques were used to examine the distribution of delta- and mu-opioid receptor-like immunoreactivity (ir) in primate spinal cord. At every segmental level examined, opioid receptor-ir formed a dense plexus of small profiles within the superficial dorsal horn. delta-Opioid receptor-ir was found in laminae I and II, whereas mu-opioid receptor-ir was confined mostly to lamina II. The distribution of opioid receptors within the superficial dorsal horn is appropriate for a localization to the central terminals of thinly myelinated and unmyelinated sensory neurons. Differences in the distribution of the delta- and mu-opioid receptors may reflect the presence of these two opioid receptor types on different functional classes of afferent neurons, or they may relate to differences in presynaptic and postsynaptic localization within the spinal gray matter.

Three new acetylenic compounds, compounds I, II and III were isolated from the cultured cells of Asparagus officinalis L. (Liliaceae) and their structures identified as 1-methoxy-4-[5-(4-methoxyphenoxy)-3-penten-1-ynyl]-benzene, 4-[5-(4-methoxyphenoxy)-3-penten-1-ynyl]phenol and 4-[5-(4-hydroxyphenoxy)-3-penten-1-ynyl]phenol, respectively, from chemical and spectral analysis.

This study was aimed at providing quantitative data on the thalamic circuitry that underlies the central processing of somatosensory information. Four physiologically identified thalamocortical relay neurons in the ventral posterior lateral nucleus (VPL) of the cat thalamus were injected with horseradish peroxidase and subjected to quantitative electron microscopy after pre- or postembedding immunostaining for gamma-aminobutyric acid to reveal synaptic terminals of thalamic inhibitory neurons. The four cells all had rapidly adapting responses to light mechanical stimuli applied to their receptive fields, which were situated on hairy or glabrous skin or related to a joint. Their dendritic architecture was typical of cells previously described as type I relay cells in VPL, and they lacked dendritic appendages. Terminals ending in synapses on the injected cells were categorized as RL (ascending afferent), F (inhibitory), PSD (presynaptic dendrite), and RS (mainly corticothalamic) types and were quantified in reconstructions of serial thin sections. RL and F terminals formed the majority of the synapses on proximal dendrites (approximately 50% each). The number of synapses formed by RL terminals declined on intermediate dendrites, but those formed by F terminals remained relatively high, declining to moderate levels (20-30%) on distal dendrites. RS terminals formed moderate numbers of the synapses on intermediate dendrites and the majority (> 60%) of the synapses on distal dendrites. Synapses formed by PSDs were concentrated on intermediate dendrites and were few in number (approximately 6%). They formed synaptic triads with F terminals and rarely with RL terminals. On somata, only a few synapses were found, all made by F terminals. The total number of synapses per cell was calculated to be 5,584-8,797, with a density of 0.6-0.9 per micrometer of dendritic length. Of the total, RL terminals constituted approximately 15%, F terminals approximately 35%, PSD terminals approximately 5%, and RS terminals approximately 50%. These results provide the first quantitative assessment of the synaptic architecture of thalamic somatic sensory relay neurons and show the basic organizational pattern exhibited by representatives of the physiological type of relay neurons most commonly encountered in the VPL nucleus.

Sieve tubes play important roles in the transfer of nutrients as well as signals. Hundreds of proteins were found in pure phloem sap collected from rice (Oryza sativa L. cv. Kantou) plants through the cut ends of insect stylets. These proteins may be involved in nutrient transfer and signal transduction. To characterize the nature of these proteins, the partial amino-acid sequence of a 13-kDa protein, named RPP13-1, that was abundant in the pure phleom sap was determined. A cDNA clone of 687 bp, containing an open reading frame of 122 amino acids, was isolated using corresponding oligonucleotides as a probe. The deduced amino-acid sequence was very similar to that of the ubiquitous thiol redox protein, thioredoxin. The consensus sequences of thioredoxins are highly conserved. No putative signal peptide was identified. Antiserum against wheat thioredoxin h cross-reacted with RPP13-1 in the phloem sap of rice plants. RPP13-1 produced in Escherichia coli was reactive to antiserum against wheat thioredoxin h. Both E. coli-produced RPP13-1 and the phloem sap proteins catalyzed the reduction of the disulfide bonds of insulin in the presence of dithiothreitol. These results indicate that an active thioredoxin is a major protein translocating in rice sieve tubes.

A treatment regimen for boron neutron capture therapy of malignant melanomas is described using 10B-paraboronophenylalanine as the tumor-targeting compound. As a therapeutic dose, we adopted the maximum tolerable dose for the skin regardless of tumor 10B concentration. In practice, the maximum neutron fluence should be decided prior to starting irradiation. For this purpose, the kinetics of the concentration of 10B in the blood and skin and the skin-to-blood ratios were analyzed in the six patients who received 170 mg/kg of the compound intravenously, and skin concentrations during irradiation were predicted using a standard skin factor curve. This yields a skin concentration at time T based on the blood concentration at time 0. We calculated the maximum tolerable fluence yielding but not exceeding 18 RBE-Gy by assuming that the RBE of 14N(n,p)14C and 10B(n, alpha)7Li reaction for skin damage is 2.5. Actual skin reactions in three of five patients treated with the therapy were, as predicted, within tolerable limits, and we were able to obtain complete tumor regression in four cases. The results indicate that application of our logical approach will be useful for subsequent cases and further development of this therapy.

We have developed neutron-capture therapy (NCT) for cutaneous malignant melanoma using a melanoma-seeking 10B-dopa, analogue, 10B1-para-boronophenylalanine (10B1-BPA). In order to explore the feasibility of applying NCT further to ocular melanoma, we investigated the boron concentrations in ocular melanomas and normal ocular tissues by 10B1-BPA administration to three patients, because success of NCT depends mainly upon selective boron accumulation in melanoma. In the first and second ocular melanoma patients, to whom 10B1-BPA fructose complex (total dose of 10B1-BPA: 170 mg/kg body weight) was administered orally in two divided doses, the boron concentrations in blood, vitreous body, sclera and retina choroidea were lower than that in melanoma examined. In the third conjunctival melanoma patient, to whom 10B1-BPA fructose complex (dose of 10B1-BPA: 85 mg/kg body weight) was administered by intravenous drip infusion, the average boron concentration in four melanoma samples was 17.7 ppm, which was estimated to be within the range necessary for melanoma eradication by thermal neutron irradiation. Boron uptake by lens, vitreous body, retina choroidea and sclera was much lower than that by melanoma. It was suggested that such a superficial ocular melanoma as iris melanoma can be destroyed by NCT, although vision may be affected--mainly due to cataract formation.

Pyramidal neurons in layers V and VI of cat primary auditory cortex (AI) were intracellularly injected with biocytin after functional characterization according to a position relative to an anteroposterior sequence of best-frequency responses. A sample of 19 completely filled neurons was analyzed, and a preliminary classification was made on the basis of dendritic morphology and axon collateral distribution. Layer V cells could be divided into two types. Cells in the upper part of layer V and projecting toward the diencephalon had a large cell body and an apical dendrite with extensive branches in layer I. These cells had few recurrent axon collaterals, and no terminal axonal bushes were formed in the vicinity of the dendritic field. Long horizontal collaterals with many boutons, however, extended in various directions parallel to the cortical surface. By contrast, cells in the lower part of layer V and sending an axon into the putamen, or without an obvious subcortical axon, had a medium soma and an apical dendrite with few branches in layer I. These cells had a dense bush of recurrent collaterals extending into layers II and III and surrounding the dendritic field, but few or no horizontal collaterals. Layer VI injected neurons were more heterogeneous. All had a thin ascending dendrite with oblique branches both ending in layer III. Axon collateral distributions varied from cell to cell. Relatively small cells with an apical dendrite that branched frequently in layers III and IV had a dense network of recurrent collaterals in the dendritic field, but virtually no horizontal collaterals. This type projected toward the diencephalon. Cells with relatively long horizontal collaterals and a weak recurrent system confined to layers V and VI had a unique arborization pattern of basal dendrites. This type may have projected to the claustrum or other cortical areas. One cell with dendritic branches restricted to layer VI had horizontal collaterals predominantly in layer VI. This cell projected into the corpus callosum. The apparent close correlation between extrinsic projections of infragranular neurons and their dendritic morphology and intracortical collateral distributions suggests that differentially projecting cells may engage different elements of intracortical circuitry in AI.

The potential of 4-borono-2-[18F]fluoro-D,L-phenylalanine ([18F]FBPA), a flurodinated derivative of a target compound for boron neutron capture therapy, for melanoma imaging by positron emission tomography (PET) was studied using animal models. A high uptake of [18F]FBPA was found in murine B16 melanoma or in Greene's melanoma No. 179, a melanotic cell line in hamsters, for the first 6 h after injection. Whole body autoradiography using [18F]FBPA gave a clear image of the B16 tumor. The acid-insoluble 18F in the B16 increased to 27% by 6 h, and most of the free 18F was detected as [18F]FBPA in both B16 and plasma. In the hamster models, No. 179 showed a 1.7 times higher uptake than amelanotic Greene's melanoma No. 178 at 6 h post-injection, although both melanomas indicated similar metabolic activities when examined by a tracer uptake study using L-[14C]methionine, 2-deoxy-D-[14C]glucose and [3H]thymidine. [18F]FBPA may be a very promising PET tracer for melanoma imaging.

The anti-allergic activity of bryonolic acid (1) isolated from the cultured cells of Luffa cylindrica L. (Cucurbitaceae) was compared with that of glycyrrhetinic acid (2), the aglycone of glycyrrhizin from licorice. Compound 1, when administered to rats intraperitoneally at a dose of 600 mg/kg, inhibited homologous passive cutaneous anaphylaxis more strongly than 2 at the same dose. Compound 1 also significantly inhibited delayed hypersensitivity in mice which could not be inhibited by 2. In contrast to 2, 1 showed not only little toxicity but no visible side effects on mice, without impairing the activity of the hepatic enzyme (4,5 beta-dihydrocortisone:NADP+ delta 4-oxidoreductase) involved in steroid catabolism.

A 65-year-old female developed peduncular hallucinosis 3 days after rupture of a basilar-superior cerebellar artery aneurysm. There were no neurological deficits except slight anisocoria when she first complained of hallucinations. Vasospasm of the perforating arteries to the upper brainstem, rather than direct brainstem damage caused by the bleeding, was probably the cause. Peduncular hallucinosis is possibly the only localizing sign of ruptured upper posterior circulation aneurysm.

The present study focuses on 3 different aspects of the descending adrenergic system in the primate: (1) the distribution of adrenergic fibers and terminals in the spinal cord, (2) the source of this input and (3) the possible physiological effects of this system on spinal nociceptive processing. Antibodies to the enzyme phenylethanolamine-N-methyltransferase (PNMT) were employed to map the distribution of epinephrine-containing axonal profiles in the primate spinal cord. Smooth longitudinally oriented fibers were localized to the outer edge of the lateral funiculus. PNMT-containing axonal enlargements were distributed to the superficial dorsal horn, intermediate gray matter and the region surrounding the central canal at all spinal cord levels. PNMT-immunostained profiles were also observed in the intermediolateral cell column. A double labeling study employing retrograde transport of HRP from the spinal cord and PNMT immunohistochemistry identified a small population of HRP-PNMT-labeled neurons in the 'C1' region at the levels of the medulla and ponto-medullary junction. Thus, these cells are a probable source of adrenergic input to the spinal cord. Electrophysiological studies demonstrated that iontophoresis of epinephrine onto identified primate spinothalamic tract neurons in the lumbar dorsal horn resulted in inhibition of the glutamate-induced firing of these cells. The data from these studies support the hypothesis that adrenergic (PNMT-containing) cells in the caudal brainstem project to all levels of the cord and may contribute to descending modulation of nociceptive processing at these levels.

10B1-para-boronophenylalanine (10B1-BPA), one of our boronated dopa analogues developed for thermal neutron capture therapy, has been found to have a selective affinity for malignant melanoma. We have established a method of 'in situ' detection of subcutaneous melanoma lesions, using this melanoma-seeking 10B-labeled compound. In this study, we applied an 'in situ' 10B microanalysis system via detection of the prompt gamma-ray from the 10B(n, alpha)7Li reaction triggered by irradiating the 10B-containing target with pure thermal neutrons, called prompt gamma-ray spectrometry, to hamsters bearing Greene's melanoma in subcutis and to a human patient whose occipital subcutaneous tumor was suspected of being a metastatic melanoma. In the hamsters, the time-dependent 10B dynamics showed increased 10B accumulation in melanoma, after 10B1-BPA administration, in contrast to that in non-melanoma normal skin. In the human patient, after subcutaneous injection of 10B1-BPA into perilesional sites 4 cm distant from the tumor margin, the average 10B concentration in the tumor was determined to be 24 ppm (microgram/g), in contrast to 3 ppm in skin covering the tumor and 1.1 ppm in blood, indicative of selectively high 10B1-BPA uptake by the tumor.

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.

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.

The cytotoxic and cytokinetic effects of prostaglandin (PG)D2 on human and rat glioma cells were studied in vitro, and the morphological changes occurring in glioma cells following PGD2 treatment were investigated by light and electron microscopy. The cytotoxic effect was evaluated by both colony formation assay and cell growth inhibition. The cytokinetic effect was analyzed by DNA histogram using a flow cytometer. It was found that PGD2 had a dose-dependent cytotoxic effect on the glioma cells and that rat C6 cells were less sensitive to PGD2 than human KY cells. Within 24h after treatment of KY cells with PGD2, a time-dependent cytotoxic effect was also observed. However, the effect of PGD2 on glioma cells was reversible at lower concentration. Investigation of KY cells treated with 2.5 micrograms/ml of PGD2 revealed that the cells in S and G2 + M phases gradually decreased in number and subsequently almost all cells were accumulated in the G0 + G1 phase 12 h later. However, no chronological change of the DNA histogram was obvious in the cells treated with a relatively high concentration of PGD2 (10 micrograms/ml). On the other hand, the treated cells showed more severe morphological changes at a higher concentration of PGD2. Glioma cells treated with PGD2 became round with cytoplasmic vacuolization and blebbing. Thus, PGD2 appears to be useful as an adjuvant chemotherapeutic agent for malignant glioma.

Cytotoxic and cytokinetic effects of Cisplatin (cisdiamminedichloroplatinum) on cultured human and rat glioma cells (KY and C6) were studied both in vitro and in vivo. The cytotoxic or cytostatic effect was evaluated by either colony formation assay or inhibition rate of cell growth. The cytokinetic effects were analyzed by DNA histogram using a flow cytometer. It was found that the cytotoxic effect of Cisplatin on the cultured glioma cells was dose-dependent, and that human KY cells and rat C6 cells had similar sensitivity to Cisplatin. Within 24 hours after treatment of KY cells with Cisplatin, a time-dependent effect was observed, but the cytotoxic effect of Cisplatin in the medium decreased rapidly. Investigation of chronological changes in the DNA histogram of KY cells treated with 0.2 microgram/ml Cisplatin revealed that cell-cycle progression was delayed in the S-phase and blocked at the S-G2 + M boundary 18 hours later. KY tumors subcutaneously transplanted into nude mice were treated with intraperitoneal injection of 3 mg/kg/day Cisplatin for 10 days and the tumors markedly regressed by 65% of their wet weight.

In the present study we have employed immunoperoxidase techniques to investigate the distribution of vasoactive intestinal polypeptide (VIP)-like immunoreactivity in the spinal cord and sensory ganglia of the cat. The spinal distribution of VIP-containing neuronal processes was also compared with that of substance P (SP), somatostatin (SOM), and cholecystokinin-8 (CCK) at lumbar, sacral, and coccygeal levels. At sacral levels, VIP was found to be contained in small and medium-sized primary sensory neurons and in dorsal rootlets. Deafferentation, by either ganglionectomy or dorsal rhizotomy, resulted in a nearly complete loss of VIP immunoreactivity in the spinal cord. The spinal distribution of VIP fibers and terminals was most dense and extensive in sacral segments. Forming a thin shell around the dorsal horn, collaterals, apparently originating from Lissauer's tract, projected either medially or laterally through lamina I. Laterally, many VIP axons terminated in lateral laminae V to VII. Others projected further through the neck of the dorsal horn to medial lamina V and the gray matter near the central canal. Medially, VIP axons descended through lamina I to expand into terminal fields in the posterior commissure and medial lamina V. At the ultrastructural level, VIP-like immunoreactivity was found in dense core vesicles within axonal enlargements containing both large dense core and smaller clear round vesicles. Synaptic connections were infrequently observed but, when encountered, were of the simple axodendritic type. The spinal distribution of VIP-containing fibers was remarkably similar to that reported for pelvic nerve visceral afferents, both in termination patterns within the spinal gray matter and in localization to the sacral cord. The density of SP-, SOM-, and CCK-containing fibers and terminals was constant at all levels examined (L4 to Co4). In marked contrast, the distribution of VIP fibers, much like that of pelvic nerve afferents, was mostly confined to sacral segments. Thus, although SP, SOM, and CCK may be contained within a population of sacral visceral afferents, they must be common to afferent systems in other segments as well. VIP, however, appears to be preferentially contained within pelvic visceral afferent fibers confined mostly to sacral segments.

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.

Adrenaline (epinephrine) is an important candidate transmitter in descending spinal control systems. To date intrinsic spinal adrenergic neurons have not been reported; thus adrenergic input is presumably derived from brainstem sites. In this regard, the localization of adrenergic neurons in the brainstem is an important consideration. Maps of adrenergic cell bodies and to a lesser extent axons and terminal fields have been made in various species, but not in monkeys. Thus, the present study concerns the organization of adrenergic systems in the brainstem of a monkey (Macaca fascicularis) immunohistochemically mapped by means of an antibody to the enzyme phenylethanolamine N-methyltransferase (PNMT). PNMT-immunostained cell bodies are distributed throughout the medulla in two principal locations. One concentration of labeled cells is in the dorsomedial medulla and includes the nucleus of the solitary tract (NTS), the dorsal motor nucleus of the vagus (X), and an area ventral to X in a region of the reticular formation (RF) known as the central nucleus dorsalis (CnD) of the medulla. A few scattered cells are observed in the periventricular gray just ventral to the IVth ventricle and on midline in the raphe. The second major concentration of PNMT-immunostained cells is located in the ventrolateral RF, lateral and dorsolateral to the inferior olive (IO), including some cells in the rostral part of the lateral reticular nucleus (LRN). Terminal fields are located in the NTS, X, area postrema (AP), and the floor of the IVth ventricle in the medulla and pons. A light terminal field is also observed in the raphe, particularly raphe pallidus (RP). A heavy terminal field is present in locus coeruleus (LC). Fibers labeled for PNMT form two major fiber tracts. One is in the dorsomedial RF extending as a well-organized bundle through the medulla, pons, and midbrain. A second tract is located on the ventrolateral edge of the medulla and caudal pons. Fibers in this tract appear to descend to the spinal cord. A comparison with maps of other catecholamine neurons in primates is discussed, confirming that the distribution of the adrenergic system in monkeys is similar to that described in the human.

The authors analyzed water-soluble proteins of culture human and rat glioma cells by two-dimensional polyacrylamide gel electrophoresis methods. Glioma cells were suspended in distilled water and then destroyed by freezing and thawing to obtain the water-soluble protein fraction. A modification of O'Farrell's non-equilibrium pH gradient (NEPHGE) method was used to analyze differences in protein mapping. Manabe's microscale two-dimensional electrophoresis without denaturing agents was used to detect proliferating cell nuclear antigen (PCNA/cyclin) by Western blotting. With O'Farrell's NEPHGE method and silver staining, at least 200 different polypeptides were clearly identified in each cell line. Cytoskeletal proteins, such as actin, were consistently separated in all cell lines. Marked differences in the protein map were observed between human and rat glioma cell lines, and even within the same species. Presumably, these differences are attributable to cell-biological difference in the glioma cells lines. Some proteins that were prominent in proliferating cells were scant in the protein maps of cells cultured for 24 hours in medium not containing calf serum, which suppresses cell growth. PCNA, an acidic nuclear protein that appears only in the late G1-S phase and is believed to be involved in cell proliferation, was detected by Western blotting and indirect immunostaining. Quantitative analysis of PCNA spots on the protein map appears useful in assessment of glioma cell proliferation. These results indicate that two-dimensional polyacrylamide gel electrophoresis can contribute to the understanding of the biological features of glioma cells.

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.

Immunohistochemical examination of transthyretin (TTR), which is known to be synthesized in the epithelial cells of the choroid plexus as well as in the liver cells, was carried out on normal brain tissues and 84 human brain tumors, using a peroxidase-antiperoxidase (PAP) technique. TTR was demonstrated diffusely and strongly in the cytoplasm of normal choroid plexus cells, but not in ependyma and other tissues of normal brain. In all of 10 choroid plexus papillomas, TTR was found within the cytoplasm of tumor cells. In contrast, neither the two papillary ependymomas nor any other brain tumors contained TTR. Among the choroid plexus papillomas, some cases showed clear positive reactions in almost all tumor cells, while others had only a few TTR-positive cells. With these immunohistochemical findings, TTR proved a very useful marker of normal choroid plexus and choroid plexus papilloma.

In the present study, we determined that a population of spinally projecting neurons in the monkey brainstem also contained the enzyme phenylethanolamine-N-methyltransferase (PNMT). Following bilateral placements of horseradish peroxidase (HRP) in the cervical spinal cord, brainstem sections containing retrogradely labeled cells were immunohistochemically stained for PNMT. Single labeled PNMT-positive cells were found in a distinctive pattern in the dorsomedial and ventrolateral medulla. A population of double labeled cells was observed in the latter group only. This population was dispersed among other single labeled HRP and single labeled PNMT neurons. Possible functional roles of descending PNMT cells include involvement in sympathetic control of cardiovascular mechanisms and/or tonic descending inhibition of dorsal horn neurons.

Neurons surrounding and dorsal to the central canal in caudal segments of the cat spinal cord were functionally and morphologically characterized. From electrophysiologically obtained responses these neurons were categorized into 3 functional groups based on excitation by somatic afferent stimulation. Eighteen of 36 units were activated by both low threshold and high threshold primary afferent inputs. Of the remaining 18 units, 9 responded only to innocuous intensities of stimulation and the other 9 were excited selectively by noxious peripheral stimulation. Neurons intracellularly marked with horseradish peroxidase formed a heterogeneous population with respect to perikaryal size, dendritic orientation and dendritic extent, and no evident correlations between functional categories and morphological features were observed in light microscopic analyses. Neurons immediately surrounding the central canal were functionally similar to neurons located in the dorsally adjacent gray matter.

Neurons surrounding the central canal in sacral spinal segments were functionally characterized on the basis of somatic and/or visceral afferent input, then intracellularly marked with horseradish peroxidase (HRP). Tissue sections containing portions of HRP-stained neurons were subsequently immunohistochemically examined for the presence of contacts made by axonal enlargements containing vasoactive intestinal polypeptide (VIP), substance P (SP), somatostatin (SS), Leu-enkephalin (ENK), or serotonin (5-HT). ENK-and 5-HT-containing enlargements were found to contact all neurons examined. SP and SS terminals contacted fewer neurons, and were not associated with specific functional classes. On the other hand, VIP-containing fibers contacted only those neurons receiving visceral afferent input, thus supporting the contention that VIP is contained in a population of visceral afferent fibers projecting to the gray matter surrounding the central canal at sacral levels.