Distribution of retinal ganglion cells projecting into the nucleus of the optic tract in the rat

Recent neurophysiological studies have disclosed that the nucleus of the optic tract (NOT) in the pretectum is the first relay station responsible for horizontal optokinetic nystagmus (OKN) both in non-foveate and foveate animals. However, what parts of the retina and what kinds of retinal ganglion cells project their fibers into the NOT have been controversial. In the present study, horseradish peroxidase conjugated with wheatgerm agglutinin (WGA-HRP) was injected into the NOT of rats. The retina and injection sites were processed for the histochemical demonstration of WGA-HRP in order to investigate the distribution of the retinal ganglion cells projecting into the NOT. The present study indicated that visual signals responsible for OKN are mainly conducted from the contralateral retinal ganglion cells, and only from the ventral area of the ipsilateral retina. The retinal ganglion cells projecting into the NOT ipsilateral to the injection site were larger than those on the contralateral side. Large retinal ganglion cells existed on the peripheral areas including ipsilateral ventral area. The density of the ventral ganglion cells of the retina contralateral to the injection site was lower than that in other areas of retina, and the density of the ventral ganglion cells ipsilateral to the injection site tented to be greater than that on the contralateral side. Since the ventral area of retina corresponded to the upper visual field in front of the nose, it may receive visual signal of OKN and fire OKN. In conclusion, visual signals responsible for OKN are conducted through the retinal ganglion cells mainly contralaterally, and only from the ventral area of the retina ipsilateral to the injection site.     

A phenytoin-sensitive cationic current participates in generating the afterdepolarization and burst afterdischarge in rat neocortical pyramidal cells

We report here on the ionic mechanisms underlying the depolarizing afterpotential (DAP) in neocortical pyramidal cells, with special interest in those underlying the burst afterdischarge. Injections of short depolarizing current pulses under whole-cell current clamp with a CsCl-based internal medium generated, in most pyramidal cells, a single action potential with a plateau phase (plateau-AP), followed by a slowly decaying DAP both in the absence and presence of TTX. Under voltage-clamp, the same cells displayed a slow tail current (tail-I) at the offset of depolarization. When intracellular free Ca²⁺ was chelated with 10 mm BAPTA or when extracellular Ca²⁺ was replaced with equimolar Ba²⁺, neither the slow DAP nor the slow tail-I was observed. Extracellular application of Co²⁺ or Cd²⁺ reduced Ca²⁺ currents and the slow tail-I. Cation substitution experiments revealed that the channel generating the slow tail-I was permeable to K⁺ and Cs⁺ more than to Na⁺ (P_K≈P_Cs > P_Na > P_NMDG≈P_TEA). The cationic slow tail-I was not reduced by applying antagonists of the metabotropic glutamate receptor (MCPG, 1 mm ) and the muscarinic receptor (atropine, 1–10 μm ). Thus, the slow DAP was produced by activation of the cationic channel whose gating is solely dependent on [Ca²⁺]_i. An increase in [K⁺]_o from 3 to 6 or 9 mm enhanced the slow DAP, and resulted in a generation of burst afterdischarges. An anticonvulsant, phenytoin (PT; 1–10 μm ) suppressed the slow DAP while enhancing the plateau-AP in the presence of TTX, most likely by blocking the cationic channel.     

Fibrolamellar hepatocellular carcinoma coexistent with a hepatocellular carcinoma of common type: Report of a case

A case of small fibrolamellar hepatocellular carcinoma (HCC) coexistent with a HCC of common type is herein reported. A 56-year-old man was diagnosed as having multi-nodular type HCC with liver cirrhosis. The serum alpha-fetoprotein (AFP) level was slightly increased. The patient underwent a partial caudate lobectomy and lateral segmentectomy. Histologically, both resected tumors were small HCCs measuring less than 2 cm in diameter. One was a fibrolamellar type located in the caudate lobe, while the other was the common type in the lateral segment of the liver. Positive immunohistochemical staining for AFP was observed in the tumor cells of the HCC of common type but was not observed in the fibrolamellar HCC. We also reviewed previously reported cases of fibrolamellar HCC in Japan, and discussed the clinicopathologic implications of this disease.     

Colon bladder replacement after total cystectomy

Although ileal conduit diversion is widely accepted in the treatment of the patients undergoing radical cystectomy, many patients would prefer other alternatives which allow continence. and urination through the urethra. We describe a new procedure in which a segment of detuburalized right colon is used as a continent reservoir. Eight patients, 7 after radical cystectomy for bladder cancer and one after total exenteration for rectal cancer, have undergone colon bladder replacement. New created bladder had a capacity of 300 to 600 ml. All patients could pass urine through the urethra but one is on self-catheterization. Five of the 8 patients had no residual urine. Three months after operations 4 were totally continent and 3 were satisfactorily dry during daytime but slightly enuretic. Excretory urography showed no abnormalities in their upper urinary tract. Considering the "quality of life' of a patient, this procedure can be an ideal option for selected patients.     

Fine structure of soft and hard tissues involved in eye migration in metamorphosing Japanese flounder (Paralichthys olivaceus)

The body of a Japanese flounder (Paralichthys olivaceus) changes from a symmetrical to an asymmetrical form during metamorphosis. To obtain detailed information on the mechanisms of the migration of the right eye to the left side, soft and hard tissues in the head of larval flounders were examined using transmission electron microscopy (TEM). Retrorbital vesicles (Rvs) are pairs of sac-like structures under the eyes. It has been suggested that the asymmetrical development of Rvs, with the right (blind) one being bigger than the left, is the driving force behind eye migration. The present study revealed that the ultrastructure of the Rv sheath is quite similar to that of a lymphatic capillary. Thus, it is possible that the Rv is a part of the lymph system, and is probably related to the secondary vascular system in teleosts. If we assume that the Rv sheath has a high permeability to liquid, similar to lymphatic capillaries, it is not plausible that the active expansion of the Rv pushes the eyeball. On the other hand, the pseudomesial bar (Pb) is a bone that is unique to flounders and is present only on the right (blind) side. At the beginning of eye migration, an aggregation of fibroblast-like cells is observed in the dermis under the right eye, where the Pb will subsequently be formed. These cells have a well-developed rough endoplasmic reticulum (rER) and mitochondria, and are probably responsible for formation of the thick layers of collagen fibrils around them. Since it is unlikely that the active expansion of the Rv causes eye migration, the role played by the Pb and its rudiment becomes more significant in right eye migration in the Japanese flounder becomes more significant.     

Adjuvant activity of synthetic 6-O-"mycoloyl"-N-acetylmuramyl-L-alanyl-D-isoglutamine and related compounds.

Adjuvant and antitumor activities of synthetic 6-O-"mycoloyl"-N-acetylmuramyl-L-alanyl-D-isoglutamine were examined. All the synthetic 6-O-corynomycoloyl-, 6-O-mocardomycoloyl-, and 6-O-mycoloyl-N-acetylmuramyl-L-alanyl-D-isoglutamine were active as adjuvants for cell-mediated immune responses. However, 6-O-mycoloyl-N-acetylmuramyl-L-alanyl-D-isoglutamine was less active as an adjuvant on circulating antibody formation. It was shown that pyrogenic activity of N-acetylmuramyldipeptide was reduced by 6-O-acylation with mycolic acid, but not with nocardomycolic or corynomycolic acid. Tumor-suppression activity was observed by the synthetic 6-O-mycoloyl-N-acetylmuramyl-L-alanyl-D-isoglutamine by using transplantable tumor in syngenic mice.     

The finite element model for the propagation of light in scattering media: a direct method for domains with nonscattering regions

We present a method for handling nonscattering regions within diffusing domains. The method develops from an iterative radiosity-diffusion approach using Green's functions that was computationally slow. Here we present an improved implementation using a finite element method (FEM) that is direct. The fundamental idea is to introduce extra equations into the standard diffusion FEM to represent nondiffusive light propagation across a nonscattering region. By appropriate mesh node ordering the computational time is not much greater than for diffusion alone. We compare results from this method with those from a discrete ordinate transport code, and with Monte Carlo calculations. The agreement is very good, and, in addition, our scheme allows us to easily model time-dependent and frequency domain problems.     

Effects of anoxia and recovery on the neurotransmission and level of high-energy phosphates in thin hippocampal slices from the guinea-pig

The effects of anoxia and recovery on the neuronal transmission and the levels of high-energy phosphates such as ATP and phosphocreatine were studied using thin hippocampal slices from the guinea-pig. For the index of neuronal activity, postsynaptic field potentials were recorded in the CA3 and CA4 regions after electrical stimulation to the dentate gyrus during deprivation of oxygen and glucose from the perfusion medium at 36.5 degrees C. With deprivation of both oxygen and glucose from the medium, neuronal activity was abolished in 6-8 min. When the deprivation period was extended longer than 15 min, no recovery in the postsynaptic field potentials was observed. The concentrations of ATP and phosphocreatine in the slices decreased to 30-40% of original levels after 10 min deprivation of oxygen and glucose. ATP and phosphocreatine recovered to the original levels with the readmission of oxygen and glucose after 10 min anoxia, but the recovery of the ATP was worsened by the longer period of deprivation. Deprivation of oxygen only slowly decreased the amplitude of postsynaptic field potentials and blocked the neuronal activity after 70 min deprivation. The postsynaptic field potentials did not reappear after 180 min deprivation of oxygen. Even 120 min after deprivation of oxygen, the ATP and phosphocreatine levels were maintained at 60-70% of originals, whereas they both decreased to 30% after 150 min anoxia. The recovery of ATP even after 150 min anoxia was 64% and the recovery of phosphocreatine was over 100% even after 180 min anoxia.(ABSTRACT TRUNCATED AT 250 WORDS)     

Identification of Goodpasture antigens in human alveolar basement membrane.

Goodpasture (GP) antigens, protein components reactive with human autoantibodies against glomerular basement membrane (GBM), were identified in human alveolar basement membrane (ABM) using an enzyme-linked immunoassay (ELISA), Western blotting and immunoprecipitation. All six anti-GBM antisera studied, three obtained from patients with glomerulonephritis and pulmonary haemorrhages (i.e. GP syndrome), and three from patients with glomerulonephritis alone, distinctively reacted with collagenase-digested (CD) ABM. Very cationic 22-28 kD and 40-48 kD components were detected by blot analysis combined with two-dimensional gel electrophoresis. These proteins showed some similarities to GP antigens in human GBM with respect to the monomer-dimer composition and charge distribution. Inhibition ELISA revealed that the binding of anti-GBM antisera to CDGBM decreased when they were pre-incubated with CDABM, suggesting that the anti-GBM antisera recognized the same epitope(s) on the GBM and ABM. Heterogeneity of the GP antigens in human ABM was demonstrated by blotting; monomeric antigens were absent or at low levels in the CDABM of three out of 10 normal individuals. In immunoprecipitation, anti-GBM antisera from patients with and without pulmonary haemorrhage showed different reactivities with CDABM. The former antisera precipitated both monomeric and dimeric components, but the latter did not. The observations of variation in monomer-dimer composition of ABM, and the different binding of anti-GBM antisera to it may explain why only some patients with anti-GBM nephritis have lung involvement.     

Immunohistochemical analysis of centromere protein F expression in buccal and gingival squamous cell carcinoma

Centromere protein F (CENP-F) expression (localization and characteristics) in relation to tumor clinicopathological parameters was immunohistochemically examined and evaluated in 47 archival biopsy specimens of buccal and gingival squamous cell carcinomas (SCC). Centromere protein F expression was detected in 79% of the samples. An increase in the labeling index (LI) with WHO grading was obtained ( P  < 0.05). Correlations were obtained between the CENP-F LI and tumor size ( P  < 0.05). Immunoelectron microscopy showed CENP-F nuclear staining as punctate or fine dots. The present study shows that CENP-F expression and detection of a more specific cell subpopulation presents a theoretical advantage for the analysis of the precise cell cycle of G₂ to M cells, compared to Ki-67.