Actions of acromelic acid on nervous system L-glutamate receptors

Acromelic acid, a naturally occurring kainoid, isolated from the mushroom Clitocybe acromelalga, is a weak displacer of [3H]L-glutamate binding to cockroach (Periplaneta americana) nerve cord membranes. Acromelic acid (1 mM) displaces approximately 60% of specifically bound [3H]L-glutamate. When applied by bath perfusion to the cell body membrane of the cockroach fast coxal depressor motor neurone, acromelic acid generated slow, prolonged, dose-dependent depolarizations at concentrations of 0.3 microM and above. Thus acromelic acid is among the most potent of the excitatory amino acids tested to date on insect neurones.

Mechanisms of the development of trazodone withdrawal symptoms

Three cases developed withdrawal symptoms of trazodone despite gradual discontinuation of therapeutic doses of the drug. This report suggests that effects of trazodone and its metabolite m-chlorophenylpiperazine on the serotonergic system, which may result in noradrenergic rebound after discontinuation, and short half-lives of these compounds are involved in the development of these symptoms. From a clinical point of view, we suggest that trazodone should be tapered off at a very slow rate.

Correlation between prolactin response and therapeutic effects of zotepine in schizophrenic patients

The correlation between prolactin response and therapeutic effects of zotepine, as assessed by the Brief Psychiatric Rating Scale, was studied in 24 schizophrenic patients (12 males, 12 females), after 4 weeks of treatment. The daily dose was 100 mg in the first week, and 200 mg for the next 3 weeks. There were significant (p < 0.05) positive correlations between changes in serum prolactin concentration and amelioration scores of positive or total symptoms in males only. Thus, prolactin response may reflect therapeutic effects of zotepine, at least in males.

Ultrastructure and cytochemical characteristics of leukocyte infected with Hepatozoon canis

We have observed the ultrastructure of a canine leukocyte infected with Hepatozoon canis by transmission electron microscope. The infected leukocytes contained many small vesicles and a few typical granules in the cytoplasm. They also contained a few rough surfaced endoplasmic reticula, mitochondria and a segmented nucleus with condensed chromatin. Cytochemical analysis indicated that the infected leukocytes with H. canis contained little alkaline phosphatase, peroxidase, naphthol AS-D chloroacetate esterase or alpha naphthol acetate esterase. These results suggested that the infected leukocytes were neutrophils or monocytes which lost their typical characteristics.

[The prediction of blood pressure after adrenalectomy in primary aldosteronism]

In 30-40% of patients with primary aldosteronism owing to adenoma, hypertension is not relieved even though a hyper-functioning adenoma has been completely removed. The purpose of this study is to determine whether the prognosis of hypertension can be evaluated pre-operatively in patients with primary aldosteronism. Thirteen patients (6 men, 7 women; 47 +/- 9 years old) with primary aldosteronism were studied and adrenalectomy was performed in all cases. The success of the operation was confirmed by the normalization of plasma renin activity (PRA), plasma aldosterone concentration (PAC) and serum potassium. Eight patients, 3 men and 5 women, whose blood pressure (BP) was reduced to below 140mmHg systolic and 90mmHg diastolic at one year after the operation were classified as "group N" and the other 5 cases, 3 men and 2 women, remained hypertensive and were classified as "group H". There were no significant differences in the age of the patients, duration of hypertension, pretreatment mean BP and severity of hypertension between the two groups. Thus, it is doubtful that the lack of improvement of hypertension is due to the irreversible damage of the small arteries. Although pretreatment BP was similar in the two groups, systolic BP after the administration of 200mg per day of spironolactone for one week was significantly reduced in group N, but not in group H. Moreover, a significant correlation was found between mean BP after treatment with spironolactone and post-operative mean BP in all subjects. Pretreatment PRA was significantly lower in group H.(ABSTRACT TRUNCATED AT 250 WORDS)

Stereoselective renal tubular secretion of carbenicillin

The stereoselective disposition of carbenicillin epimers was studied in healthy human volunteers. There was a difference between the two epimers in the extent of plasma protein binding in vitro, with the unbound fraction of the R epimer being greater than that of the S epimer. Renal clearance (CLR) of each epimer was greater than the glomerular filtration rate, suggesting renal tubular secretion of both epimers. Although the CLR was greater for the R epimer, renal tubular secretion was greater for the S epimer. When probenecid was coadministered, the CLR of each epimer was significantly reduced and was approximately equal to the glomerular filtration rate. The difference in CLR between the two epimers was simply due to differences in plasma protein binding. The observations in the present study suggest that both carbenicillin epimers are secreted by an organic anion transport system in the renal proximal tubule in humans and that the two epimers may be distinguished in the secretion process, resulting in the differences in the secretion rates.

Osmoregulation in Paramecium: the locus of fluid segregation in the contractile vacuole complex

In a previous study, monoclonal antibody DS-1 was found to specifically label the decorated spongiome along the radial arms of the contractile vacuole complexes in Paramecium multimicronucleatum. Fluorescein isothiocyanate-conjugated DS-1, when injected into cells, labels the radial arms initially, but with increasing postinjection time both the intensity of fluorescence and the number of fluorescently labeled radial arms were reduced. When these cells were fixed after 45 minutes and probed indirectly using a second fluorochrome, little new label was seen on the already fluorescein-labeled radial arms. Thin sections showed that the amount of decorated tubules along some collecting canals decreased from the proximal to the distal end and vesicles, which were never seen in control cells, appeared next to the decorated spongiome. These results suggested that the decorated spongiome was undergoing disassembly and sequestration into one region of the cell. The injected DS-1 also reduced the expulsion frequency of the contractile vacuoles in a dose-, time- and site-dependent manner. The contractile vacuole complexes near the injection site were affected more than those farther from the site, but the sizes of both contractile vacuoles were only transiently affected so that fluid output per cell was reduced by approximately 60%. Beyond 45 minutes postinjection, both the expulsion frequency and total fluid output began to recover as the DS-1 was sequestered into one part of the cell. This region persisted in cells up to 18 hours but disappeared by 24 hours, which coincided with the full recovery of the expulsion frequency and of decorated spongiome along the radial arms. The contractile vacuole, the collecting canals and the smooth spongiome were morphologically unaffected. These results indicate that when the decorated spongiome is dissociated from the contractile vacuole complex, the complex's function is strongly inhibited, showing the decorated spongiome to be the site of fluid segregation.

Elevated cytosolic free calcium concentrations in platelets of hypertensive drinkers: a weak association with alcohol consumption

Although the mechanisms of alcohol related hypertension remain unknown, it has been hypothesised that alcohol causes the accumulation of calcium ions (Ca2+) in vascular smooth muscle cells, resulting in the elevation of vascular tonus. To evaluate this contention, intra platelet free calcium concentrations (platelet [Ca2+]i) were determined in 20 young adult men, i.e. five each of hypertensive heavy drinkers, hypertensive light drinkers, normotensive heavy drinkers, and normotensive light drinkers. Platelet [Ca2+]i were higher in the ten hypertensives than in the ten normotensives, irrespective of alcohol consumption. The hypertensive drinkers also showed higher levels of serum gamma-glutamyl transpeptidase (gamma-GTP) and parathyroid hormone (PTH). Platelet [Ca2+]i in the total 20 subjects did not correlate with alcohol consumption, but correlated positively with serum gamma-GTP levels and SBP. These preliminary study results do not support the contention that Ca2+ accumulates in the vascular smooth muscle cells of humans as a result of chronic alcohol consumption. The significance of elevated platelet [Ca2+]i observed in the hypertensive heavy drinkers in the pathogenesis of alcohol related hypertension remains obscure.

A new metabotropic glutamate receptor agonist: developmental change of its sensitivity to receptors in the newborn rat spinal cord

A novel metabotropic glutamate receptor agonist, (2S,1'R,2'R,3'R)-2-(2,3-dicarboxycyclopropyl)glycine (DCG-IV), reduced the monosynaptic excitation in newborn rat spinal cord rather than polysynaptic discharges at the nanomolar range without causing postsynaptic depolarization of motoneurones. Its inhibitory action on the monosynaptic excitation reduced in due course of time after birth. On the contrary, the inhibitory action of a metabotropic GABAB receptor agonist, baclofen, did not show marked developmental change. DCG-IV should be expected to have the potential to provide further useful information on the physiological function of metabotropic glutamate receptors.

High fermentative production of L-threonine from acetate by a Brevibacterium flavum stabilized strain transformed with a recombinant plasmid carrying the Escherichia coli thr operon

Decrease in L-threonine productivity caused not only by plasmid-free segregation but also by plasmid deletion was observed in a Brevibacterium flavum L-threonine producer when transformed with a recombinant plasmid carrying Escherichia coli thr operon. However, a recombinant strain, HT-16, was stabilized by the addition of trimethoprim (a selective marker on the vector) at concentration of 1000 micrograms/ml, which was rather higher than the minimum inhibitory one, into the stock culture medium. Strain HT-16 produced 64.4 g/liter of L-threonine, 30% higher than that of the host strain, after 92 h of cultivation in a small jar fermentor using acetic acid as a carbon source without trimethoprim.

Primary aldosteronism with ipsilateral adrenal cyst: report of a case

Adrenal cysts are rare; most lack endocrinologic activity and do not produce clinical symptoms. The present case is the first to be reported with both an adrenal cyst and a functioning adenoma present ipsilaterally. This 39-year-old male with hypertension was diagnosed as having primary aldosteronism as reflected by hypokalemia and an excess plasma aldosterone concentration (PAC). However, examination by computed tomography revealed a grossly enlarged left adrenal gland with a cyst-like lesion. The right adrenal appeared normal. At surgery, an adenoma and a cyst were found to coexist in the left adrenal cortex. The cyst fluid contained three times the amount of aldosterone present in plasma, less than in previous reports, and was considered to lack endocrinologic activity. Following a left adrenectomy, the patient's blood pressure, serum potassium concentration, and PAC all normalized without the need for medical treatment.

(2S,3S,4R)-2-(carboxycyclopropyl)glycine, a potent and competitive inhibitor of both glial and neuronal uptake of glutamate

The effects of several diastereoisomers of L-2-(carboxycyclopropyl)glycine (CCG) on L-glutamate uptake were compared among three different preparations, glial plasmalemmal vesicles (GPV), synaptosomes and cultured astrocytes from rat hippocampus. The (2S,3S,4R)-isomer (L-CCG-III) inhibited a Na(+)-dependent high-affinity L-glutamate uptake in GPV and synaptosomes in a dose dependent manner at a micromolar range. The potency was quite similar to that of L-threo-beta-hydroxyaspartate in both subcellular fractions and much higher than L-aspartate-beta-hydroxamate, which were known as potent inhibitors of glutamate uptake. The (2S,3R,4S)-isomer (L-CCG-IV) also inhibited the glutamate uptake in GPV and synaptosomes, but it was about 100 times less active than L-CCG-III. The (2S,3S,4S)- and (2S,3R,4R)-isomers (L-CCG-I and L-CCG-II, respectively) hardly showed any inhibitory action on the glutamate uptake. Dixon plot analysis of the initial uptake rate revealed that the inhibition was in a competitive manner and the value of the inhibition constant (Ki) was about 1 microM in both GPV and synaptosomes. L-CCG-III effectively inhibited the glutamate uptake by cultured hippocampal astrocytes as well. These results suggested that L-CCG-III inhibited the glutamate uptake in both neurones and glial cells of the mammalian central nervous system in a similar manner.

A novel metabotropic glutamate receptor agonist: marked depression of monosynaptic excitation in the newborn rat isolated spinal cord

1. Neuropharmacological actions of a novel metabotropic glutamate receptor agonist, (2S,1'R,2'R,3'R)-2(2,3-dicarboxycyclopropyl)glycine (DCG-IV), were examined in the isolated spinal cord of the newborn rat, and compared with those of the established agonists of (2S,1'S,2'S)-2-(carboxycyclopropyl)glycine (L-CCG-I) or (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid ((1S,3R)-ACPD). 2. At concentrations higher than 10 microM, DCG-IV caused a depolarization which was completely blocked by selective N-methyl-D-aspartate (NMDA) antagonists. The depolarization was pharmacologically quite different from that caused by L-CCG-I and (1S,3R)-ACPD. 3. DCG-IV reduced the monosynaptic excitation of motoneurones rather than polysynaptic discharges in the nanomolar range without causing postsynaptic depolarization of motoneurones. DCG-IV was more effective than L-CCG-I, (1S,3R)-ACPD or L-2-amino-4-phosphonobutanoic acid (L-AP4) in reducing the monosynaptic excitation of motoneurones. 4. DCG-IV (30 nM-1 microM) did not depress the depolarization induced by known excitatory amino acids in the newborn rat motoneurones, but depressed the baseline fluctuation of the potential derived from ventral roots. Therefore, DCG-IV seems to reduce preferentially transmitter release from primary afferent nerve terminals. 5. Depression of monosynaptic excitation caused by DCG-IV was not affected by any known pharmacological agents, including 2-amino-3-phosphonopropanoic acid (AP3), diazepam, 2-hydroxysaclofen, picrotoxin and strychnine. 6. DCG-IV has the potential of providing further useful information on the physiological function of metabotropic glutamate receptors.

[Treatment of urinary tract anomalies detected by prenatal ultrasonography]

Twelve pediatric patients with antenatal diagnosed urinary tract anomalies from 1988 to 1992 in Niigata University Hospital were clinically examined. 1: All patients were diagnosed by ultrasonography. Eleven cases did not have any abnormal pregnancy and other had oligohydramnious. 2: Postnatal surgical treatments were performed in 11 cases, but antenatal therapy was not performed in any case. 3: Temporary percutaneous nephrostomy (PNS) were carried out on 7 kidneys in 6 cases during infantile period seems to be effective in preserving function of congenital obstructed kidneys.

Silent brain infarction and coronary artery disease in Japanese patients

OBJECTIVE

Silent brain infarction is fairly common in the elderly, but predictive factors have not been definitively established. This study focuses attention on ischemic heart disease and cerebrovascular risk factors about the frequency of silent brain infarction.

DESIGN

The existence of silent brain infarction, the extent of coronary artery stenosis, and cerebrovascular risk factors of consecutive 92 case series with suspected ischemic heart disease were surveyed.

SETTING

A hospital for patients with ischemic heart disease.

PATIENTS

Ninety-two consecutive Japanese patients with suspected ischemic heart disease were recruited.

MAIN OUTCOME MEASURES

All subjects were evaluated for coronary atherosclerosis (number of coronary arteries with significant stenosis and Gensini score), the number of silent brain infarctions detected by computed tomography, the extent of carotid atherosclerosis as determined by B-mode ultrasonography, and cerebrovascular risk factors.

RESULTS

Patients with silent cerebral infarctions were older (66.2 +/- 10.4 years) than those without such events (60.1 +/- 8.8 years) (P < .01). The extent of coronary atherosclerosis in patients with silent cerebral infarctions was significantly greater than in those without such events after adjustment for the effect of age (P < .001). The extent of carotid atherosclerosis and the percentages of individuals with hypertension, diabetes mellitus, a smoking habit, hypercholesterolemia, hypertriglyceridemia, and a low serum high-density lipoprotein cholesterol level did not differ between the groups with and without silent brain infarction. The frequency of silent brain infarction increased with the severity of coronary stenosis.

CONCLUSION

Coronary atherosclerosis and age were important risk factors for silent brain infarction.

[Cases of lethal midline granuloma (polymorphic reticulosis) at our department in a recent 10-year period]

We had 18 patients (15 males and 3 females) with lethal midline granuloma (polymorphic reticulosis) in the period from 1981 to 1990. This number was about 5.6% of the total number of patients with malignant head and neck tumors that we encountered during this period. An average of 9.1 months separated the first appearance of disease and the beginning of treatment. Most of the 18 patients underwent both radiation therapy and chemotherapy (COP, CHOP, MACOP-B), but, since their disease had reached an advanced stage, 3 underwent radiation therapy only, 3 underwent chemotherapy only, and 1 received no radical therapy at all. Of the 18 patients, 13 died of the disease. In of 6 of these, the disease was confined to the local lesion. The 5-year cumulative survival rate was 15.7% (Kaplan-Meier). Fourteen autopsy studies revealed that tumor cells had invaded the liver (92.8%), lung (92.8%) and spleen (71.4%) and in all cases it was in leukemic patterns. Fifteen cases were studied for tumor surface marker phenotype, but none was found to be positive for L26, CD43, Leu M1 (CD15), or MAC 387. Five cases were positive for UCHL-1 (CD45RO) and 10 cases were positive for lysozyme. All cases were positive for Ki-1 (CD30).

[Therapeutic and adverse effects of zotepine and their relationships with serum kinetics of the drug]

The spectrum of therapeutic and adverse effects of zotepine and their relationships with serum concentrations of the drug were investigated in 28 schizophrenic inpatients by a fixed-dose (100 mg/day for the first 1 wk and 200 mg/day for the following 3 wk) study. The mean % improvement in Brief Psychiatric Rating Scale (BPRS) scores were 63.4% for total, 64.4% for positive, 41.8% for negative and 74.2% for anxiety-depression symptoms, suggesting that zotepine has a broad therapeutic spectrum. There were significant differences in improvement of negative symptoms after 1 wk and total and positive symptoms after 2 wk (P < 0.05) between responders (more than 50% reduction in total BPRS scores at wk 4) and nonresponders. The mean scores of UKU Side Effect Rating Scale were low in this study. UKU scores of psychic at wk 2 and total adverse effects at wk 3 and wk 4 (P < 0.05) were higher in nonresponders than in responders. A negative correlation between % improvement in total BPRS and total UKU scores was observed (P < 0.05). These two results suggest some relationship between poor clinical response and increased adverse effects during zotepine treatment. Lack of close correlation between serum drug concentrations and clinical or adverse effects indicates that therapeutic monitoring of zotepine concentrations would be of little significance.

Antioxidant protection against oxidant-induced damage in cultured gastric mucosal cells

Gastric epithelium is exposed not only to oxidants generated within the lumen, but also to those produced by ischemia/reperfusion. This study examined the mechanism(s) of oxidant-induced injury to cultured rat gastric mucosal cells, and characterized the antioxidant profile of these cells. Hydrogen peroxide (H2O2), generated by glucose oxidase, damaged cells dose-dependently, as assessed by increased leakage of labeled 51Cr. Glucose oxidase-induced damage was prevented by exogenous catalase (but not by exogenous superoxide dismutase). Chelation of cellular iron with desferrioxamine or phenanthroline specifically protected cells against H2O2, whereas binding of extracellular iron with apotransferrin failed to. Disruption of the glutathione redox cycle at three independent sites rendered cells less resistant to H2O2, whereas inhibition of cellular catalase did not result in sensitization of cells to H2O2. In conclusion, (1) oxidant injury induced by extracellular H2O2 is mediated by intracellular iron; (2) extracellular superoxide is not involved in the damaging process; and (3) the glutathione redox cycle plays a principal role in detoxifying H2O2 as a cellular antioxidant in cultured gastric mucosal cells.

Improvement of detection in computed radiography by new single-exposure dual-energy subtraction

It is reported that the use of the dual-energy subtraction method enhances the abnormal shadow detection capability. However, because the subtracted image is significantly inferior to the original in signal-to-noise ratio (SNR), the x-ray dosage normally used for chest x-rays has not yielded subtracted images with adequate SNRs. Under these circumstances, we focus on the fact that there is a correlation between the noise contents of bone-and soft-tissue-subtracted images although there is no correlation between the signal contents of these images. We propose an algorithm that improves SNRs of subtraction images by reducing the noise only.

Pregnancy complicated by the May-Hegglin anomaly

May-Hegglin anomaly is a prepotent autosomal hereditary disease characterized by giant thrombocytes, thrombocytopenia and continuous appearance of inclusion bodies (Döhle like corpuscle) in the cytoplasm of granulocytes. In this report we report our experience of a case whose pregnancy was complicated by this disease. This anomaly is rare and there are only 15 families reported in this country. The only clinical symptom is the tendency to bleed, but since this is not rare, it may be necessary to consider examination of peripheral blood in every case of thrombocytopenia. If this disease complicates pregnancy, it is important to plan the mode of delivery to consider both the maternal and fetal prognosis.

Five cases of mucormycosis in paranasal sinuses

Five cases of mucormycosis are reported, 2 of them suffered from immunosuppression, the other 3 did not. We conclude that a combination of CT and bacteriological findings is useful for the diagnosis of mucormycosis differentially from other diseases. Therapy consisted of paranasal debridement and administration of amphotericin B.

Inhibitory effect of xian-qing-long-tan extract on degranulation and histamine release from rat mast cells

Xian-Qing-Long-Tang (XQLT), a Chinese medicine, is useful for treating allergic diseases. To demonstrate the anti-allergic effect of this drug we examined its effect on degranulation and histamine release from rat mast cells induced by antigen and compound 48/80. The effect on 48 h homologous passive cutaneous anaphylaxis (PCA) in rats was also studied. In the IgE antigen-antibody reaction using DNP-As, XQLT inhibited histamine release from rat mast cells, in vitro; it also inhibited 48 h rat homologous PCA reaction, in vivo. These results suggest that XQLT inhibits type 1 allergic reaction, and has effectiveness for allergic disease.