Reduced Autophagy in Aged Trigeminal Neurons Causes Amyloid ß Diffusion.

The relationship between oral health and the development of Alzheimer's disease (AD) in the elderly is not yet well understood. In this regard, the association between aging or neurodegeneration of the trigeminal nervous system and the accumulation of amyloid-ß(1-42) (Aß42) oligomers in the pathogenesis of AD is unknown. We focused on selective autophagy in the trigeminal mesencephalic nucleus (Vmes) and the diffusion of Aß42 oligomers with respect to aging of the trigeminal nervous system and whether the degeneration of Vmes neurons affects the diffusion of Aß42 oligomers. We used female 2- to 8-mo-old transgenic 3xTg-AD mice and AppNL-G-F knock-in mice and immunohistochemically examined aging-related changes in selective autophagy and Aß42 oligomer processing in the Vmes, which exhibits high amyloid-ß (Aß) expression. We induced degeneration of Vmes neurons by extracting the maxillary molars and examined the changes in Aß42 oligomer kinetics. Autophagosome-like membranes, which stained positive for Aß, HO-1, and LC3B, were observed in Vmes neurons of 3xTg-AD mice, while there was weak immunoreactivity of the membranes for intraneuronal Aß in AppNL-G-F mice. By contrast, there was strong immunopositivity for extracellular Aß42 oligomers with the formation of Aß42 oligomer clusters in AppNL-G-F mice. The expression of Rubicon, which indicates age-related deterioration of autophagy, increased the diffusion of Aß42 oligomer with the age of Vmes neurons. Tooth extraction increased the extracellular immunopositivity for Aß42 oligomers in AppNL-G-F mice. These results suggest that autophagy maintains homeostasis in Vmes neurons and that deterioration of autophagy due to aging or neurodegeneration leads to the diffusion of Aß42 oligomers into the extracellular space and possibly the development of AD.

First Report of Nectria haematococca Stem Girdling of Greenhouse Peppers in Florida.

Nectria haematococca Berk. & Broome causing stem girdling of three cultivars of greenhouse pepper, Capsicum annuum (cvs. Kelvin, Cubico, and Grizzly), was found for the first time in a single greenhouse in south Florida in March 1999. Approximately 10% of the plants were affected at first report increasing to over 40% within 3 months. Black lesions occurred at nodes where the plant was pruned or where fruit had been harvested. No mycelium or perithecia were noted in association with the lesions. All tissue above a lesion appeared normal until the lesion girdled the stem, causing the tissue above the lesion to wilt and die. The plant appeared unaffected below the lesion. The pathogen was isolated on half-strength Difco potato-dextrose agar (½ DPDA). Reddish perithecia developed readily in culture. Two single spore isolates of the pathogen obtained from two naturally infected plants (cultivar Kelvin) were used to satisfy Koch's postulates. Five plants of Kelvin were inoculated with each isolate by inserting a 4-mm agar block of the pathogen grown for 5 days on ½ DPDA into the stem. Five plants of the same cultivar were similarly treated with fungus-free ½ DPDA. Plants were grown under greenhouse conditions after inoculation. In four plants, black lesions similar to those seen in the commercial greenhouse developed within 1 week. In one plant, the portions of the plants above the point of inoculation wilted after 5 days. The upper parts of the plants appeared healthy until lesions girdled the stems. The plants treated with fungus-free agar remained healthy. The fungus was re-isolated from the margins of lesions on the inoculated plants. The pathogen has been reported to cause stem lesions and fruit rot of pepper in greenhouses in England (1) and Canada (2). Fruit symptoms were not observed in the Florida greenhouse. Stem symptoms were again reported from the same greenhouse in the following season. References: (1) J. T. Fletcher. Plant Pathol. 43:225-222, 1994. (2) W. R. Jarvis. Can. Plant Dis. Surv. 74:131-134, 1994.

Phencyclidine-induced abnormal behaviors in rats as measured by the hole board apparatus.

RATIONALE: Phencyclidine (PCP) and methamphetamine (MAP) are known as psychotomimetic agents. Both agents produce behavioral alterations in animals. OBJECTIVE: The present study investigated the difference in behavioral alterations in rats induced by these two psychotomimetic agents using the hole board apparatus (HBA). In addition, mechanisms underlying PCP-induced behavioral changes were also investigated. METHODS: After the administration of PCP (1-4 mg/kg SC) or MAP (1-4 mg/kg SC), locomotor activity and dipping behavior were assessed using HBA. Effect of selective NMDA antagonists, (+)MK801 and 3-((+/-)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP), on rat behaviors were also assessed. The effects of D-alanine (D-Ala), a coagonist of NMDA receptors, or neuroleptics, haloperidol, clozapine and risperidone, on PCP-induced behavioral changes were investigated. RESULTS: PCP increased locomotor activity and decreased exploratory behaviors of rats in HBA. On the other hand, MAP increased locomotor activity but did not decrease exploratory behaviors. (+)MK-801 produced hyperactivity as well as decreased exploratory behaviors, eliciting behavioral changes very similar to those of PCP. CPP decreased the exploratory behavior but failed to produce hyperactivity. D-Ala attenuated both behavioral changes induced by PCP. Three neuroleptics tested here inhibited hyperactivity but did not attenuate decreases in exploratory behavior. CONCLUSION: These results suggest that PCP-induced decrease in exploratory behavior are attributable to antagonism of NMDA receptors and may not involve dopaminergic transmission via D2 receptors.

Flow injection determination of iodide ion in a photographic developing solution using iodide ion-selective electrode detector.

A potentiometric flow injection determination method for iodide ion in a photographic developing solution was proposed by utilizing a flow-through type iodide ion-selective electrode detector. The sensing membrane of the electrode was Ag(2)S-AgI membrane. The response of the electrode detector as a peak-shape signal was obtained for injected iodide ion in a photographic developing solution. A linear relationship in the subnernstian zone was found to exist between peak height and the concentration of the iodide ion in a photographic developing solution in a concentration range from 0 to 6.0x10(-5) mol l(-1). The relative standard deviation for ten injections of 2x10(-5) mol l(-1) iodide ion in a photographic developing solution was 0.96% and the sampling rate was approximately 12-13 samples h(-1). The iodide ion could be determined under coexisting of an organic reducing reagent and inorganic electrolytes of high concentration in a photographic developing solution sample solution by the present method.

[Effects of benidipine hydrochloride (Coniel) on blood pressure, heart rate and plasma norepinephrine concentration in spontaneously hypertensive rats].

We investigated the effects of benidipine hydrochloride (benidipine, Coniel) on blood pressure, heart rate and plasma norepinephrine (NE) concentration in spontaneously hypertensive rats and compared them with those of other calcium channel blockers. Benidipine (2 mg/kg, p.o.) was compared with the equihypotensive doses of nifedipine (5 mg/kg), cilnidipine (6 mg/kg) and amlodipine (3 mg/kg). All the 4 calcium channel blockers exhibited significant antihypertensive effects. Nifedipine and cilinidipine significantly increased heart rate, as compared with that in the control group, whereas benidipine or amlodipine did not significantly affect it. The area under the curves for hypotensive effect and tachycardic effect for 10 hr after the drug administration were compared among the 4 compounds. As a result, the tachycardic effect of benidipine was significantly lower than those of nifedipine, cilnidipine and amlodipine, while the hypotensive effects were similar among the 4 compounds. Nifedipine and amlodipine, significantly increased plasma NE concentration, cilnidipine tended to increase it. In contrast, benidipine did not significantly affect plasma NE concentration. These results suggest that the effects of benidipine on plasma NE concentration and heart rate are less prominent than those of the other calcium channel blockers.

NMDA induced glutamate release from the suprachiasmatic nucleus: an in vitro study in the rat.

The suprachiasmatic nucleus (SCN) has been identified as a pacemaker for mammalian circadian rhythms. Excitatory amino acid receptors, especially N-methyl-D-aspartate (NMDA) receptors, have been considered to play an important role in the transmission of light information from the retina to the circadian clocks in the SCN. In the present study, we showed that application of NMDA at circadian time (CT) 12-15 induced significant glutamate release from the SCN region in vitro. The NMDA-induced glutamate release was blocked by co-application of the NMDA receptor antagonist MK-801, but not by that of tetrodotoxin. These results suggested that glutamate stimulated its own release by activating NMDA receptors. This NMDA-induced glutamate release through NMDA receptor-mediated mechanisms might be involved in NMDA-induced potent phase shifts.

A Psorosis-Like Agent Prevalent in Florida's Grapefruit Groves and Budwood Sources.

Rio Grande Gummosis (RGG) is one of the most serious diseases of grapefruit in the Indian River region of Florida. Experiments were conducted to determine if a graft-transmissible agent was associated with this disease in commercial grapefruit, and if any such agent was present in scion sources used for grapefruit propagation. Indexing data from indicators revealed that 79% and 31% of the commercial grapefruit and scion trees, respectively, contained a psorosis-like agent (PLA). The PLA was present in both RGG-affected and symptomless trees. We conclude that Florida's grapefruit propagation sources are contaminated with a PLA that is now widespread in commercial plantings.

Powdery Mildew of Field-Grown Tomato in Florida.

Powdery mildew was observed affecting mature, field-grown, fresh-market tomatoes in southeastern Florida (St. Lucie, Martin, Palm Beach, and Broward counties). Outbreaks were noted in May of 1996 and throughout the spring of 1997. Affected leaves were generally yellow and, in some cases, developed a purplish cast. Whitish areas of fungal growth were often seen in the middle of lesions, but were less prominent than that reported for powdery mildew of field tomato in Hungary (2). Microscopic examination revealed that conidia were produced in chains, contained no fibrosin bodies, and were not dimorphic. Conidial measurements were 33.2 × 15.6 µm, based on 21 samples of five conidia taken from five different fields. These measurements were similar to those for an Erysiphe sp. causing powdery mildew of greenhouse tomato in New York (1). Greenhouse-grown tomato plants, cv. Sunny, in the fourth-true-leaf stage were inoculated with conidia scraped from lesions gathered in commercial fields. A single-edged razor blade was used to transfer the fungus to the adaxial surface of the test plants. Powdery mildew symptoms were observed within 10 days of inoculation. Morphology and size of conidia taken from greenhouse plants were similar to those for original field samples. This is the first report of powdery mildew of field-grown tomato in Florida. References: (1) D. M. Karasevicz and T. A. Zitter. Plant Dis. 80:709, 1996. (2) L. Kiss. Plant Dis. 80:224, 1996.

Pharmacological studies on YM992, a novel antidepressant with selective serotonin re-uptake inhibitory and 5-HT2A receptor antagonistic activity.

YM992 ((S)-2-[[(7-fluoro-4-indanyl)oxy]methyl]morpholine monohydrochloride) is a novel compound that has selective serotonin (5-hydroxytryptamine, 5-HT) re-uptake inhibition and 5-HT2A receptor antagonistic activity in vivo. YM992, fluoxetine and citalopram showed 5-HT uptake inhibition activity in l-5-hydroxy-tryptophan (l-5-HTP)-treated mice. YM992 and trazodone attenuated 5-HT2A/2C receptor agonist-induced head-twitches in mice, indicating that these drugs had 5-HT2A receptor antagonistic activity. YM992 and amitriptyline were highly active in the mouse tail suspension test. In contrast, fluoxetine and citalopram showed only a tendency to reduce the immobility time. Single treatment with YM992 as well as trazodone and fluoxetine ameliorated the learning deficit of olfactory-bulbectomized rats, whereas citalopram and amitriptyline showed an ameliorative effect only after chronic treatment. Although YM992 has moderate affinity for alpha1-adrenoceptors, alpha1-adrenoceptor antagonism of YM992 in vivo was 10 times weaker than that of trazodone. These results demonstrate that YM992 has 5-HT uptake inhibition and 5-HT2A receptor antagonistic activity in vivo, and suggest that YM992 may be a novel antidepressant with high efficacy in clinical use.

Ustiloxins, antimitotic cyclic peptides from false smut balls on rice panicles caused by Ustilaginoidea virens.

Ustiloxins A (1a), B (1b), C (1c), D (1d) and E (1e), antimitotic peptides, have been isolated from the water extract of false smut balls caused on the panicles of rice plant by a fungus Ustilaginoidea virens. The structure of 1b was assigned from its spectral property and its amino acid analysis in relation to 1a whose structure was determined previously by a combination of X-ray crystallographic and amino acid analyses. Structures of 1c and 1d were elucidated by their spectroscopic data, specially based on their 1H and 13C NMR spectra. Bioactivities of these compounds against microtubule assembly as well as mammal, plant and fungal cells have been studied.

Aluminium beta-cyclodextrin sulphate as a stabilizer and sustained-release carrier for basic fibroblast growth factor.

The water-insoluble aluminium salt of beta-cyclodextrin sulphate (Al.beta-CyD-Sul) was used as a stabilizer and sustained-release carrier for recombinant human basic fibroblast growth factor (bFGF). An adsorbate of bFGF with Al.beta-CyD-Sul was prepared by incubating the protein with a suspension of Al.beta-CyD-Sul in water. The mitogenic activity of bFGF released from the adsorbate, as indicated by the proliferation of kidney cells of baby hamster (BHK-21), was almost comparable with that of the intact bFGF. Al.beta-CyD-Sul significantly protected bFGF from proteolytic degradation by pepsin and alpha-chymotrypsin, compared with the water-soluble sodium salt. The in-vitro release of bFGF from the adsorbate was sustained in proportion to a rise in the ratio of Al.beta-CyD-Sul to the protein in the adsorbate. Of the bFGF preparations evaluated, the adsorbate of bFGF with Al.beta-CyD-Sul, when given subcutaneously to the rat, showed the most prominent increase in the formation of granulation tissues, due to the stabilization and slow-release of the mitogen. The limited data presented here suggest that the adsorbate of bFGF with Al.beta-CyD-Sul has a potent therapeutic efficacy for wound healing, and may be applicable to oral protein formulations for the treatment of intestinal mucosal erosions.

"Lupinosis"-like lesions in mice caused by ustiloxin, produced by Ustilaginoieda virens: a morphological study.

A crude toxin, obtained by methanol-extraction of a water extract of false smut balls (INA-KOUJI in Japanese) caused by Ustilaginoidea virens on rice panicles, was injected into mice intraperitoneally. Single injection of 100 or 200 mg/kg body weight of the extract was not lethal but caused acute, occasional necrosis of hepatocytes and renal tubular cells, followed by increased number of mitotic figures with occasional multinuclear giant cells. Erosions and ulceration of the forestomach and atrophy of the thymus were observed a week later. Repeated intraperitoneal injection of the crude toxin at the levels of 12 and 25 mg/kg body weight induced more severe necrosis of the liver and kidneys, with delayed occurrence of mitosis. Forestomach erosion also occurred. Serial injection for 10-12 days of either 3 or 6 mg/kg of the crude extract or 400 micrograms/kg of ustiloxin A, using the purified crystals, caused relatively mild but definite liver and kidney lesions similar to those described above. The lesions in the liver and kidney were quite similar to those observed in lupinosis caused by phomopsin A, a mycotoxin produced by Phomopsis leptostromiformis. Isolation of the toxic substance indicates that the contaminated rice panicles may cause toxicosis of cattle, although no field outbreaks have occurred yet.

Clinical application of atrial natriuretic polypeptide in patients with congestive heart failure: beneficial effects on left ventricular function.

Synthetic alpha-human atrial natriuretic polypeptide was infused in patients with congestive heart failure (CHF) (New York Heart Association class III or IV) and in those without CHF. The infusion of atrial natriuretic polypeptide (ANP) at a rate of 0.1 microgram/kg/min significantly decreased pulmonary capillary wedge pressure and increased stroke volume index in all of the patients with CHF, whereas it decreased pulmonary capillary wedge pressure but caused no significant change in stroke volume index in the patients without CHF. Concomitant significant reductions in total systemic resistance were observed in both groups of patients. The ANP infusion significantly increased the urine volume, the excretion of sodium, and endogenous creatinine clearance in the patients without CHF. In the patients with CHF, it also showed a tendency to increase all these variables, but the urine volume did not correlate with the reduction in pulmonary capillary wedge pressure. The ANP infusion also decreased plasma aldosterone concentrations in these patients, although no significant difference was observed in the decrement of the plasma aldosterone concentration in the patients with and those without CHF. These findings indicate that the ANP infusion improves left ventricular function in patients with CHF, and suggest that this improvement results mainly from the vasodilating activity of ANP.

Hemodynamic effects of intravenous diltiazem in patients with acute myocardial infarction.

Experimentally, diltiazem has demonstrated favorable effects on acute myocardial infarction in animals. In this study, we administered diltiazem intravenously to 11 patients with acute myocardial infarction within 24 hours from the onset and examined the hemodynamic changes. Dose was 20 minutes of 0.5 mg/min and 20 minutes of 1.0 mg/min (i.e., total 30 mg). Hemodynamic results were decrease in heart rate, blood pressure (systolic, diastolic), mean arterial pressure, double product (p less than 0.01), and systemic vascular resistance (p less than 0.05). On the other hand, stroke volume index increased (p less than 0.01). There were no significant changes in mean pulmonary capillary wedge pressure, cardiac index, and stroke work index. Serum diltiazem concentrations during intravenous administration in our study were near the steady-state plasma concentrations in which oral multiple-dose administration of diltiazem 60 mg twice or thrice daily resulted in 2 to 3 days. It is concluded that diltiazem can be administered safely to patients with acute myocardial infarction in acute phase and has two favorable hemodynamic effects on acute myocardial infarction. One is decrease of afterload, as evidenced by the decrease in systemic vascular resistance and in mean arterial pressure. Second is the decrease of double product as an index of myocardial oxygen consumption.

Induction of coronary artery spasm by acetylcholine in patients with variant angina: possible role of the parasympathetic nervous system in the pathogenesis of coronary artery spasm.

We injected acetylcholine (ACh), the neurotransmitter of the parasympathetic nervous system, into the coronary arteries of 28 patients with variant angina. Injection of 10 to 80 micrograms ACh into the coronary artery responsible for the attack induced spasm together with chest pain and ST segment elevation or depression on the electrocardiogram in 30 of the 32 arteries of the 25 of the 27 patients. The injection of 20 to 100 micrograms ACh into the coronary artery not responsible for the attack in 18 patients resulted in various degrees of constriction in most of them, but no spasm in any of them. After intravenous injection of 1.0 to 1.5 mg atropine sulfate, the injection of ACh into the coronary artery responsible for the attack did not induce spasm or attack in any of the nine coronary arteries injected in eight patients. We conclude that the intracoronary injection of ACh induces coronary spasm and attack in patients with variant angina and that the activity of the parasympathetic nervous system may play a role in the pathogenesis of coronary spasm. We also conclude that the intracoronary injection of ACh is a useful test for provocation of coronary spasm.