Is there a third peripheral catecholaminergic system? Endogenous dopamine as an autocrine/paracrine substance derived from plasma DOPA and inactivated by conjugation

In mammals, the sympathetic neurotransmitter is norepinephrine (NE), and the main adrenomedullary hormone is epinephrine (EPI). The sources and physiological roles of the third endogenous catecholamine, dopamine (DA), outside the brain have been obscure. Several lines of evidence suggest that in the periphery, rather than DA serving only as the precursor for the active compounds, released from sympathetic nerves and the adrenal medulla, DA may also act as an autocrine/paracrine regulator of local organ function. Thus, in the kidneys, most of DA formation appears to be from proximal tubular uptake of plasma DOPA, and binding of locally formed DA to dopaminergic receptors decreases Na/K ATPase activity and thereby accentuates natriuresis. In the gastric mucosa, DA may modulate sodium absorption and acid secretion. Recent clinical and laboratory animal evidence has indicated that the lungs and mesenteric organs contribute substantially to total body production and metabolism of DA. Generation of DA in non-noradrenergic, non-adrenergic cells can explain why human urine contains higher concentrations of DA and its metabolites than of NE and its metabolites. The vast preponderance of plasma DA in humans is sulfoconjugated. Since patients with sympathoneural failure have normal plasma levels of DA sulfate, one may speculate that the sulfoconjugating mechanism is relatively independent of sympathetic nerves and acts to localize DA effects and inactivate DA entering the circulation. These considerations lead to the concept of a third peripheral catecholaminergic system, where DA derived from plasma DOPA acts as an autocrine/paracrine substance and is inactivated by conjugation.

Amino acids and glucose differentially increased extracellular 5-hydroxyindoleacetic acid in the rat brain

To reveal the role of serotonergic neurons in the regulation of feeding, the levels of 5-hydroxyindoleacetic acid (5-HIAA), a metabolite of serotonin, in the striatum and the hypothalamus were continuously monitored by an in vivo microdialysis technique. Intake of 20% casein diet did not induce significant changes in the 5-HIAA level in these regions. When rats were fed on 5% casein diet (83.5% carbohydrate diet) for 2 h, the level of 5-HIAA in the striatum gradually increased and reached a maximum (226 +/- 44% of basal level, M +/- SEM, n = 7) at 4 h after stopping the diet. In the medial hypothalamus, its level also increased to 183 +/- 19% (n = 10) at 2 h after starting the diet. On the other hand, a 60% casein diet increased the level of 5-HIAA in the lateral hypothalamus to 138 +/- 19% (n = 10) at 2 h after starting the diet. The intravenous infusion of each of these nutrients, glucose, amino acid mixture or lipid, produced more rapid elevation of the 5-HIAA level than oral intake of the diets. When rats were infused with glucose, its level in the striatum continued to be elevated. In the medial hypothalamus, glucose infusion increased 5-HIAA to the maximum (189 +/- 38%, n = 7) at 4 h after starting infusion. In contrast, serotonergic neurons in the lateral hypothalamus seemed to respond only to infusion of the amino acid mixture, and the level of 5-HIAA reached 163 +/- 14% (n = 5) of the basal level at 1 h after starting the infusion. These results suggest that rapid elevation of glucose or amino acids may independently stimulate serotonin metabolism in these brain areas, participating in the feedback regulation of nutrient intake.

Trabeculectomy with mitomycin C for normal-tension glaucoma

PURPOSE

A prospective investigation of the postoperative intraocular pressure level, visual function changes, and postoperative complications of trabeculectomy with adjunctive mitomycin C in normal-tension glaucoma.

PATIENTS AND METHODS

Thirty-one patients (31 eyes) who underwent trabeculectomy with 0.4 mg/ml mitomycin C were studied. The preoperative intraocular pressure of the eyes ranged from 11 to 18 mm Hg with a mean (+/- SD) of 14.1 +/- 1.9 mm Hg. Follow-up examinations were performed at least once a month for 14-35 months (mean: 24.4 months).

RESULTS

Intraocular pressures decreased to between 4 and 14 mm Hg with a mean (+/- SD) of 8.4 +/- 2.4 mm Hg at the last three follow-up visits. The magnitude of the intraocular pressure reduction ranged from 1 to 10 mm Hg, with a mean of 5.8 mm Hg. Final measurements of postoperative intraocular pressure ranged between 5 and 12 mm Hg in 27 eyes (87%). Visual acuity deteriorated two lines or more in seven eyes, which was caused by cataract. The visual field deteriorated postoperatively in two eyes (6%): their respective postoperative intraocular pressures averaged 9.4 and 7.5 mm Hg. Hypotonous maculopathy developed in three eyes (10%).

CONCLUSIONS

Trabeculectomy with mitomycin C appears to have potential as a treatment modality of choice for normal-tension glaucoma, because a large majority of the patients in the present study achieved an intraocular pressure allegedly beneficial in managing normal-tension glaucoma.

The substantia nigra is a major target for neurovirulent influenza A virus

Clinical and immunohistochemical studies were done for 3-39 d on mice after intracerebral inoculation with the neurovirulent A/WSN/33 (H1N1; WSN) strain of influenza A virus, the nonneurovirulent A/Aichi/2/68 (H3N2; Aichi) strain, and two reassortant viruses between them. The virus strains with the WSN gene segment coding for neuraminidase induced meningoencephalitis in mice. The mice inoculated with the R96 strain, which has only the neuraminidase gene from the WSN strain, had mild symptoms and weak positive immunostaining to the anti-WSN antibody in meningeal regions. Both the WSN and R404BP strains, which contain the WSN gene segments coding for neuraminidase and matrix protein, were clearly neurovirulent both clinically and pathologically. On day 3 after inoculation with either of these two strains, WSN antigen was detected in meningeal and ependymal areas, neurons of circumventricular regions, the cerebral and cerebellar cortices, the substantia nigra zona compacta, and the ventral tegmental area. On day 7, meningeal reactions and neuronal staining were still seen, and advanced accumulation of the viral antigen was evident in the substantia nigra zona compacta and hippocampus. Double immunostaining demonstrated that the WSN antigen was only seen in neurons and not in microglia or reactive astrocytes. Immunostaining for the lectin maackia amurensis agglutinin, which recognizes the Neu5Ac alpha 2,3 Gal sequence, which serves as a binding site for influenza A virus on target cell membranes, showed that positive staining was localized in the ventral substantia nigra and hippocampus. These results suggest that neurovirulent influenza A viruses could be one of the causative agents for postencephalitic parkinsonism.

Ethanol as a xanthine dehydrogenase inhibitor

In the present study, we investigated whether ethanol inhibits the activity of xanthine dehydrogenase. Ethanol and/or inosine were administered to normal subjects, and plasma concentration and urinary excretion of purine bases were measured together with blood concentrations of lactic acid and pyruvic acid. In addition, ethanol and pyrazinamide were administered to these subjects, and plasma concentration and urinary excretion of pyrazinamide and its major metabolites were measured. Increases in plasma concentration and urinary excretion of xanthine induced by a combination of ethanol and inosine were greater than the sums of increases induced separately by ethanol and inosine, although increases in plasma concentration and urinary excretion of uric acid induced by the combination of ethanol and inosine were not different from the sums of increases induced separately by ethanol and inosine. Ethanol increased the ratio of blood lactic acid to blood pyruvic acid and decreased plasma concentration and urinary excretion of 5-hydroxypyrazinamide and 5-hydroxypyrazinoic acid. These results suggest that ethanol inhibits xanthine dehydrogenase presumably by an ethanol-induced increase in the cytosolic concentration of NADH in the liver.

Inhibitory activity in saliva of cell-to-cell transmission of human T-cell lymphotropic virus type 1 in vitro: evaluation of saliva as an alternative source of transmission

Human T-cell lymphotropic virus type 1 (HTLV-1) is known to be transmitted vertically through breastfeeding and horizontally by blood transfusion and sexual contact. Our intervention study has suggested the presence of additional alternative maternal transmission pathways. To explore the possibility of transmission through saliva, we used PCR to quantify the HTLV-1 provirus in saliva samples from 18 carrier mothers and 10 patients with HTLV-1-associated myelopathy/tropical spastic paraparesis. The provirus was detected in 60 and 90%, respectively, of the samples, with estimated copy numbers in the range of 10 to 10(4)/ml. However, the saliva, regardless of the presence or absence of antibodies to the virus, showed a strong tendency to inhibit the cell-to-cell transmission of HTLV-1 in vitro, as examined by a syncytium inhibition assay. The natural inhibitory activity in saliva of seronegative volunteers was heat sensitive, and most of the activity was recovered by ultrafiltration in the fraction of macromolecules with a molecular weight of more than 100,000. In addition to this natural activity, saliva of HTLV-1-infected individuals contained immunoglobulin G molecules capable of neutralizing syncytium formation. These results strongly suggested that HTLV-1-infected cells in the carriers' saliva, which contains neutralizing antibodies in addition to the natural activity inhibiting cell-to-cell viral infection, barely transmit the virus. Transmission of HTLV-1 through the saliva would thus seem to be rare, if it occurs at all.

[Pulse-dose cyclophosphamide therapy for steroid-refractory autoimmune neurological diseases]

Eight patients with neuroimmunological disorders refractory to conventional immunotherapies were given totally 17 courses of pulse-dose cyclophosphamide. The regimen consisted of 600 mg/m2 of intravenous cyclophosphamide at days 1,2,4,6 and 8 and infusion of 2,500-3,000 ml of fluids in order to avoid hemorrhagic cystitis. Some cases were followed by a monthly intravenous dose of cyclophosphamide as a booster treatment. As a result, all but one case of neuro-Behçet disease have shown neurological improvements. In particular, a complete remission was obtained in two cases of vasculitic neuropathy and a case of chronic inflammatory demyelinating polyneuropathy. The side effects, notably, granulocytopenia, alopecia, hemorrhagic cystitis and anorexia, are major problems. Granulocytopenia started 10 days after the first dose and the number of leucocytes was the lowest at day 15. However, the number steadily recovered thereafter without the use of granulocyte colony stimulating factor. There was no serious infections during the course. For neuroimmunological disorders, the pulse-dose cyclophosphamide therapy would serve a useful alternative when the conventional therapies are not efficacious or difficult to continue because of the adverse side effects.

Morphologic examination of rabbit nasal mucosa after the nasal administration of insulin peanut oil suspension and a powder dosage form with soybean-derived sterylglucoside

Soybean-derived sterylglucoside mixture (SG) is a potentially effective absorption enhancer for the nasal absorption of insulin. Insulin is a peanut oil suspension dosage form and in a powder dosage form with SG were administered into the rabbit nasal cavity. After 0.5 or 1 h, nasal mucosa was taken from the nasal cavity and side effects were examined by an optiphoto light microscope. The insulin in the peanut oil suspension produced a histological change in the nasal epithelium mucosae, as well as mucodermal phlogistic cellular infiltration. The peanut oil suspension with SG showed side effects slightly stronger than without SG. SG alone and the insulin powder dosage form with SG produced no signs of inflammation, erosion or squamous metaplasia. The results from this study indicate that SG can be considered safe.

[Four cases of acute myositis associated with influenza A infection in the elderly]

In nursing home belonging to our hospital, influenza like syndromes were recognized in 40 of 250 cases (16%) in 1994, and 5 cases were admitted to our hospital. On admission, three patients were unable to walk, and creatine phosphokinase levels were elevated in all patients, ranging from 337 IU/l to 20,672 IU/l. There were normal test findings for electrocardiography, ultrasonic cardiography. Three patients showed a significant antibody titer fall (Hemagglutinin Inhibition) in six months. The other patient did not show it, but his symptom was compatible with influenza. All patients recovered rapidly without sequelae. We reported four cases in the elderly of acute myositis associated with influenza A (H3N2) infection.

POEMS syndrome with central nervous system involvement: a case report

POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes) syndrome was found to be associated with a disorder of the central nervous system (CNS) in a 56-year-old woman. Elevated intracranial pressure, neuroimaging evidence of diffuse white matter edema and papilledema point to a disease process affecting the CNS. Brainstem auditory (BAEPs) and visual evoked potentials (VEPs) also provided evidence of reduced central conduction velocities without, however, apparent clinical deficits attributable to CNS involvement. The intracranial hypertension is thought to be a part of a generalized tendency toward edema characteristic of this particular syndrome. We speculate that POEMS syndrome is an autoantibody-mediated immunological disorder in which cerebral vascular endothelium is one of the targets of the immunopathogenetic process and undergoes subsequent enhancement of vascular permeability.

Xylitol-induced increase in the concentration of oxypurines and its mechanism

We investigated the effect of xylitol on the plasma concentration and the urinary excretion of purine bases, 5-hydroxypyrazinamide and 5-hydroxypyrazinoic acid in subjects who had ingested pyrazinamide (60 mg/kg weight). One liter of 10% xylitol was infused intravenously over 2 hours to 5 subjects to whom pyrazinamide had been administered 10 hours before. Xylitol increased the plasma concentration of uric acid, hypoxanthine and xanthine, the urinary excretion of hypoxanthine and a ratio of lactic acid/pyruvic acid in blood, while it decreased the plasma concentration and the urinary excretion of inorganic phosphate, 5-hydroxypyrazinamide and 5-hydroxypyrazinoic acid. These results suggested that in addition to an increase in purine degradation by xylitol, xylitol-induced increase in the cytosolic NADH inhibited xanthine dehydrogenase activity in the liver and the small intestine.

Transient expression of type I collagen in glomeruli with anti-Thy-1 antibody-induced mesangial proliferative lesions

Glomerular expression of extracellular matrices at the protein and mRNA levels was examined in rats with mesangial proliferative glomerulonephritis induced by the intravenous administration of a monoclonal anti-rat Thy-1 antibody. In close association with the mesangial proliferative lesion, type I collagen was immunostained at day 8 but not demonstrated at day 28 in the glomeruli of the kidneys. Type I collagen mRNA expression prominently increased in the nephritic glomeruli at day 4, prior to the appearance of type I collagen protein. In addition, fibronectin expression was also elevated in the diseased glomeruli at both the protein and mRNA levels. These results indicated that glomerular, probably mesangial cells, change their phenotypes during this disease, to synthesize abnormal extracellular matrices that lead to the progression of glomerular sclerosis.

Mucosal regeneration of gastric ulcer confirmed by electronic endoscopy

We studied the detailed surface structure and changes in the regenerated mucosa during the course of healing of recurrent gastric ulcers treated with lansoprazole or famotidine, using a magnifying electronic endoscope (videoendoscope) and a dye contrast method. The detailed patterns of regenerated mucosa were classified into five types: membranous, spindle-shaped, palisade-shaped, cobblestone-shaped, and almost normal structure. Initially, the membranous regenerated mucosa appears at the ulcer margin and grows into the spindle- and palisade-shaped regenerated mucosa. These latter types of mucosa change gradually into the cobblestone-shaped type, which finally develops into an almost normal structure. Lansoprazole appeared to bring about more rapid growth and changes of the regenerated mucosa than famotidine, although the difference was not statistically significant. We suggest that it is useful, in the assessment of gastric ulcer therapy, to observe the detailed patterns of the regenerated mucosa during the healing process using a magnifying electronic endoscope.

Hepatic failure in a case of multiple myeloma-associated amyloidosis (kappa-AL)

We report a case of kappa-AL amyloidosis which rapidly developed hepatic failure in a 79-year-old Japanese female who was admitted to our hospital because of abdominal distension and loss of appetite. Laboratory examination revealed a marked deterioration of liver function with cholestasis and monoclonal gammapathy. At the time that the diagnosis of IgG-kappa type multiple myeloma was made, jaundice was advanced, with continuous gastrointestinal bleeding. The patient died of hepatic failure 2 weeks after admission. Needle biopsy of the liver revealed a diffuse, massive deposition of amyloid protein.

An intestinal fistula in a 3-year-old child caused by the ingestion of magnets: report of a case

We describe herein the case of a 3-year-old child in whom a jejunoileal fistula was caused by the ingestion of magnets. This case report demonstrates that if more than one magnet is found as a foreign body in the intestine, they should not be left untreated even if there are no sharp edges and, it seems they could be evacuated spontaneously. This recommendation is made because the magnets will attract each other and hold the intestinal walls between them, causing necrosis and resulting in intestinal perforation or a fistula.

Vasopressin increases AQP-CD water channel in apical membrane of collecting duct cells in Brattleboro rats

The effect of vasopressin on subcellular localization of AQP-CD and AQP3 water channels was examined in thirsted Brattleboro rats by immunohistochemistry and immunoelectron microscopy. AQP-CD was mainly present in the cytoplasm of the collecting duct cells in association with cytoplasmic vesicles but was sparse in the apical membrane in control vehicle-injected rats. In rats given vasopressin 15 min before death, the number of immunogold particles for AQP-CD in the apical membrane increased significantly (P < 0.002) from 1.8 +/- 0.2 to 10.0 +/- 0.4/microns with a significant decrease (P < 0.05) of cytoplasmic labeling from 32.6 +/- 6.4 to 24.6 +/- 5.6/microns 2, indicating that AQP-CD is the vasopressin-regulated water channel predicted by the "shuttle" hypothesis. In contrast, AQP3 was restricted to the basolateral membrane of the collecting duct cells, and the labeling density of AQP3 was unchanged by vasopressin treatment, indicating that AQP3 is constitutively expressed and may maintain high water permeability of the basolateral membrane.

[Primary oculomotor nerve palsy due to head injury: analysis of 10 cases]

Ten cases of primary oculomotor nerve palsy due to head injury are presented. All ten patients had a dilated, non reactive pupil. Seven had complete oculomotor palsy. Two had partial extraocular palsy or blepharoptosis and one had neither extraocular palsy nor blepharoptosis. The initial ophthalmoplegia was recognized immediately after trauma. Nine patients had severely impaired consciousness on admission, but eight patients recovered fully within two months after the traumatic event, while one patient remained disoriented. Emergency CT scan on admission showed mass lesions in no patients except one who had a hematoma measuring 3 cm in the frontal lobe, but had no herniation sign. Patients with complete oculomotor palsy had a high incidence of traumatic SAH (71%) or skull fracture (57%). Recovery from third nerve palsy was not so good. The follow-up period extended from 3 months to 18 months. Of the 10 patients, none recovered completely from third nerve palsy. The prognoses of blepharoptosis, external ophthalmoplegia and internal ophthalmoplegia were analyzed separately. The recovery rates were 78%, 44% and 20%, respectively, the internal ophthalmoplegia showing poorest recovery. We discuss the mechanism of direct injury to the oculomotor nerve.

Visceral epithelial cells in rat glomerular cell culture

The purpose of this study was to identify and characterize visceral epithelial cells (VECs) of renal glomeruli in culture. Such cells have been described variably as regular, polygonal cells showing a high rate of replication and a cobblestone-like appearance at confluence and also as irregular, arborized and often multinucleated cells showing a very limited proliferative capacity. We examined early outgrowths from the glomeruli by immunofluorescence microscopy using antibodies specific for VECs (anti-podocalyxin(1A), anti-pp44 and 5-1-6), for endothelial cells (anti-von Willebrand factor (vWF) and RECA-1) and for mesangial cells (anti-Thy-1). 1A and anti-pp44 reacted with several types of irregular, arborized cells, but never with regular, polygonal cells. 5-1-6 did not react with any of the cells. Neither the 1A- nor anti-pp44-positive cells (1A/pp44(+) cells) stained with anti-vWF, RECA-1 or anti-Thy-1. However, all the 1A/pp44(+) cells expressed desmin and vimentin but not cytokeratin. These results show that the 1A/pp44(+) cells are derived from VECs, supporting the idea that most polygonal cells in glomerular cultures are of parietal epithelial origin.

Accumulation of plasma cells in atherosclerotic lesions of Watanabe heritable hyperlipidemic rabbits

By screening a cDNA library constructed from aortic total RNA derived from Watanabe heritable hyperlipidemic (WHHL) rabbits by differential hybridization, we have obtained a cDNA encoding the kappa light chain of immunoglobulin. Northern blot analysis of total RNA prepared from aortas of WHHL and normal rabbits of various ages revealed that this light-chain mRNA accumulates gradually with age in aortas in WHHL rabbits. Northern blotting and in situ hybridization with an antisense oligonucleotide specific to rabbit immunoglobulin gamma heavy-chain mRNA also detected accumulation of this heavy-chain mRNA in advanced lesions of WHHL rabbit aortas. Moreover, immunohistochemical and electron microscopic analyses demonstrated the presence of plasma cells in the atherosclerotic lesions.

Selective inhibition of spontaneous pulmonary metastasis of Lewis lung carcinoma by 5'-deoxy-5-fluorouridine

5'-deoxy-5-fluorouridine (5'-FUdR) is a cytostatic that is biotransformed to 5-fluorouracil (5-FUra) by pyrimidine nucleoside phosphorylase (PyNPase), the expression of which is up-regulated by tumor necrosis factor alpha (TNF alpha), interleukin-1 alpha (IL-1 alpha) and interferon gamma (IFN gamma). In Lewis lung carcinoma (LLC) cell cultures, these inflammatory cytokines up-regulated the expression of type-IV collagenase, metastatic factor, as well as PyNPase and consequently enhanced the antiproliferative activity of 5'-FUdR. However, the activity of 5-FUra was not enhanced. It appears that 5'-FUdR selectively kills highly metastatic cells which are exposed to these intrinsic cytokines in tumor tissues, because of their high PyNPase activity. In fact, 5'-FUdR inhibited the spontaneous metastasis of LLC from the s.c. inoculation site to the lung. When 5'-FUdR was given during the process of metastasis it greatly reduced the number of tumor nodules in the lung even at doses 46 times lower than those inhibiting the primary tumor growth. In addition, 5'-FUdR, but not 5-FUra, lowered type-IV collagenase levels in the tumors at the low dose showing only anti-metastatic activity. On the other hand, 5-FUra showed anti-metastatic activity at doses similar to or only several times lower than those inhibiting the primary tumor growth.

Aversive taste stimuli facilitate extracellular acetylcholine release in the insular gustatory cortex of the rat: a microdialysis study

The release of extracellular acetylcholine (ACh) in the insular gustatory cortex of conscious rats during taste stimulation was measured using the microdialysis technique. The mean basal release of ACh before stimulation was 273 +/- 21 fmol/10 microliters (mean +/- S.E.M., n = 25). Intraorally applied taste stimuli or distilled water significantly increased the release of ACh. Among them, infusion of 0.001 M quinine HCl produced a marked increase in the release of ACh up to 355% of baseline levels. Infusion of 0.01 M saccharin to the subjects that had acquired an aversion to this taste also caused a prominent increase in ACh up to 343% of basal levels. In contrast, saccharin infusion to the naive subjects moderately increased ACh up to 243% of baseline. Water infusion resulted in the smallest increase in ACh up to 175% of baseline. Although intraoral infusions of quinine or distilled water caused a significant increase in ACh in the parietal cortex, the magnitude of increased ACh was smaller than that in the gustatory cortex. These results suggest that ACh release in the insular gustatory cortex is related to behavioral expression to aversive taste stimuli.