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The evidence of mucocutaneous leishmaniasis transmission in the non-forest environment in the Ribeira Valley region, São Paulo, Brazil, has made this epidemiologic four years' study possible, viewing the enzootic activity of L. (V.) braziliensis. Furthermore, the natural infection in small mammals and the domestic dog population has been completed in collecting of phlebotomine sandflies in the forest and peridomiciliar environments. Positive test-results have only been found in resident dogs (Canis familiaris) with a rate of 5.6 and 2.4% for serological and parasitological test respectively. Among silvatic and synanthropic rodents collected, Oryzomys (Olygoryzomys) and Rattus rattus are pre-eminent having both been collected in equal proportions, in peridomiciliar environment. The sandfly Lutzomyia intermedia has contributed only with 166 feminine specimens due to insecticide (DDT) application on and in the human and domestic habitations. From the general epidemiologic standpoint the fragile L. (V.) braziliensis cycle in the unforested areas as well as the canine and small mammals roles as a domiciliar infection source are discussed, and their potencial in the dispersion of this parasite in the researched area is analysed too.

A case of severe tetanus showing clinical features compatible with sympathetic overactivity (SOA) is reported. A 64-year-old man was admitted to our hospital 6 days after injury. The clinical signs of SOA developed on the second day in ICU. Through the clinical investigation of this case, we found out and insisted on some new concepts about the clinical features of SOA. 1. Lability of arterial pressure is parallel to that of catecholamine level in serum. 2. Two different types in SOA were found. One is dominantly lable type of Adrenaline and another is of Noradrenaline. 3. Drawing a sharp line between 2 types by assessment of circulatory data from Swan-Ganz catheter is significant for deciding therapeutic lines.

Rapid measurement of serum intact parathyroid hormone concentration was achieved by modification of an immunoradiometric assay for the hormone. Incubation of serum samples for 15 min at 37 degrees C under shaking gave optimal results in terms of assay variance and reproducibility: intra-assay CVs were less than 10% over the hormone concentrations of 11-1,600 pg/ml; intra- and inter-assay CVs for two control sera at different hormone levels were less than 12%. The minimal detectable hormone concentration was found at 27.8 pg/ml. The serum hormone levels of 43 subjects (31 health subjects, 9 patients with primary hyperparathyroidism, and 3 patients with secondary hyperparathyroidism) determined by either rapid or regular assay well correlated with each other (r2 = 0.979, p less than 0.001). In two patients with parathyroid adenoma serum intact PTH levels fell rapidly to 12.1% of the preoperative values 20 min after ligation of the vascular pedicle to the hyperfunctioning glands. We conclude that the modified assay protocol allows rapid, accurate, and simple estimation of intact PTH concentrations, and can be used as an intraoperative measure to aid both diagnosis and surgical cure of hyperparathyroidism.

Nine plants were evaluated for their insecticidal actions on Callosobruchus chinensis L: Agcratum conyzoides, Blumea baJsimifera, Chrysanthemum indicum, Coleus amboinicus, Vitex negun-do, Azadirachta indica, Cocos nucifera, Capsicum frutesccns and Piper nigrum. By filter paper impregnation method, the oils of the first seven plants exhibited contact toxicity with mortality ranging from 66 to 100% at 100 mg/ml, 48 hrs after exposure. At the same concentration, the oils were more toxic when mixed with the seeds, giving 100% mortality at 24 hours. C. amboinicus oil was the most toxic causing 93% mortality at 10 mg/ml within 15 minutes exposure, while the rest of the oils gave mortalities ranging from 43 to 100% 24 hours after exposure. Seed treatment at 5 mg inhibited egg laying by 71 to 100%. Mungbean seed treated with ground P. nigrum and C frutescens at 600 ppm was very toxic (91% mortality) after 48 hours exposure and was residually toxic 6 months after treatment to the weevils. P. nigrum inhibited the development of Fl progenies. Exposure of the bean weevil to mungbean treated with oils/extracts/powders from the test plants exhibited one or a combination of the following actions: toxicity, repellancy, antioviposition and growth inhibition. GC-mass infrared analysis of the volatile oil from sambong and its fractions showed the presence of sesquiterpe-noidal compounds. Purification and identification of the active compounds are in progress.

The authors report an instance of familial moyamoya disease involving a 47-year-old female and her 18-year-old daughter, both of whom initially presented, within a 1-year period, with intracranial hemorrhage. Cerebral angiography showed the typical features of moyamoya disease. The mother, whose disease was more advanced, underwent superficial temporal-middle cerebral artery bypass, with satisfactory results. Human leukocyte antigen typing was performed in both cases. The pertinent literature is reviewed.

A precise method of measuring vertebral mineral content by quantitative computed tomography (QCT) using reference phantom was conducted. In order to minimize the error, the lumbar spine to be measured should be brought to the center of CT gantry, the phantom should be brought into close contact with the subject for measurement, scanning should be carried out on 10 mm slice thickness and the region of interest should be selected as large as possible. Comparison of QCT values among various CT scanners was difficult. This method was useful for the measurement of trabecular mineral content of lumbar vertebra in clinical practice.

A new annihilation technique for antimatter search is under development of the balloon experiments in the Antarctica. The capability of antiparticle‐particle discrimination of the detector is about 10−9 by combining the Cherenkov technique, 10−5, which was confirmed by using accelerator antiproton beams, and topological methods, 10−4. The polar balloon flight with the 1/4 m2 detector will reach to the flux sensitivities around 10−7 level for antiprotons and antiheliums and the 10−6 level for heavier antinuclei.

We report the appearance of lymphocutaneous sporotrichosis on the left arm of a 28-year-old farmer's wife, followed two months later by the same type of lesion on the right upper eyelid of this patient's three-year-old child. According to the mother, the child was accustomed to sleeping with the right side of her face applied to the lesion on the mother's arm, and so it was presumed that the infection had been transmitted by direct contact from mother to child. Cases of person-to-person contagion of this disorder are thought to be extremely rare, but where there has been close contact on a daily basis, such contagion is likely to occur.

A new murine malignant fibrous histiocytoma (MFH) cell line was established from a 4-hydroxyaminoquinoline 1-oxide-induced MFH. This cell line was followed by a contiguous sheet, and a confluent monolayer was established after 12 days incubation. These cells could be serially transplanted into the subcutaneous tissue of mice, the success rate becoming 100% after the 9th passage. Transplanted tumors demonstrated rapid growth and displayed a high potential for metastasis to the lung after the 16th passage. And a 100% lung metastasis rate was observed for MFH cells after the 20th passage. Histologically, these metastatic tumors retained features of the primary tumor.

Cytidylate cyclase was demonstrated to be distributed in various tissues of rat, with the highest activity in brain, and it was shown to be a membrane-bound type enzyme. The enzyme was effectively dispersed from the membrane fraction of rat brain with 0.3% (w/v) Triton X-100. The dispersed cytidylate cyclase had an optimal pH of 9.4 and the activity at a physiological pH of 7.5 was less than 20% of the maximum value. This enzyme completely lost its activity in the absence of divalent cation such as Mn2+ and Mg2+. The Km value for CTP was calculated as 0.0156 mM, by Lineweaver-Burk analysis. It was also found that activity of dispersed enzyme was inhibited by ATP, but not GTP. Both forskolin and lanthanum chloride, which affect adenylate cyclase, showed no effect on cytidylate cyclase. These results indicate that cytidylate cyclase is a unique membrane-bound enzyme distinct from purine nucleotide cyclases, adenylate cyclase and guanylate cyclase.

Some raw material characteristics were evaluated in three apple varieties Gala, Gold and Fuji. The study was undertaken to collect information in order to identify the effects of initial tissue properties on mass transport phenomena in general, and osmotic processing responses in particular. The apples, obtained from the local market, were washed, peeled and cut into 10 mm cube. After this, the samples were dehydrated in sugar osmotic solution (50% w/w) at 30°C and 110 rpm of agitation. The ratio of foodstuff to osmotic solution was greater than 1:20. The mass transfer kinetics was measured in intervals of 20 minutes during 3 hours. The mass transfer kinetics of the different apple varieties has presented different behavior during the osmotic dehydration. The apples vs. Gala have presented the highest water loss and solid gain. The vs. Gold presented a lower tendency to solid uptake.

Various utility-interactive photovoltaic power conditioning systems have been reported. In general, it could be said that such photovoltaic power conditioning systems have been approaching the ideal, i.e. high efficiency, high performance etc. However, the system cost including that for power converters and solar cells still prevents widespread application. A simple utility-interactive photovoltaic power conditioning system with a forward converter and an innovative lossless snubber circuit are proposed. They are easy to utilise and complement each other. The system operation is confirmed by simulation analysis and experiment.

Although a large number of studies have been made on a theory of scattering, no studies have been attempted to evaluate the scattered sound fields in a concert hall. This paper will show an evaluation method of sound fields that involve scattered reflection by a circular‐columns array installed in front of both side walls. Measurements were performed by use of a 1/10 scale model of the concert hall. Here, scattered sound fields are evaluated by four acoustic factors (SPL, DT1, Tsub; IACC, and in addition WIACC and tauIACC). It is found that the IACC and Dt1 of the sound fields of the concert hall are improved with use of the circular columns array.

The city of Tsuyama is located about 100 kilometers west of Kobe. The fundamental shape of the plan and cross sections of the hall were designed by applying the theory of subjective preference [Ando, Architectural Acoustics (AIP Press/Springer‐Verlag, New York, 1998)]. Special attempts made in the acoustic design of this hall are: (1) a number of columns distributed in front of the walls at the audience level and on the stage: This may keep a small value of the IACC and a certain initial time delay gap between the direct sound and the first reflection, making an increase of the subjective preference for both listeners and musicians; (2) a stage enclosure with the canopy of several triangular reflectors at adjustable height for musicians, to control the preferred delay time of the reflections in performing a certain type of music; and (3) the shape of the rear wall of the stage, to control the IACC for listeners.

Instrumented Charpy impact test has been widely used as a simple method for semi-empirically evaluating material impact toughness. The authors have developed a new instrumented Charpy impact testing system, which is called CAI (Computer Aided instrumented Charpy Impact testing) system. Using the CAI system, dynamic fracture toughness parameters such as Kd, Jd, Tmat, and various absorbed energies can be obtained from the load-deflection curve of a single precracked specimen for both ductile and brittle materials. It has been already put into practical use in Japan. This paper introduces the details of the toughness evaluation procedures in the CAI system.

Degenerative change at the end plate of the discovertebral joint was studied in the elderly adult by correlating the histologic and radiographic findings. Undecalcified ground sections were made from 21 autopsied lumbar spines that demonstrated no evidence of disease except age-related osteoporosis. Histologic examination showed that the cartilaginous end plates were degenerated to various extents and were replaced by subchondral bone proliferation (endochondral bone formation) in the direction of the joint space. In advanced cases, this histologic finding was reflected in radiographs as a subchondral sclerotic zone protruding toward the disk space. The degree of end-plate change was positively correlated with disk-space narrowing and the vacuum phenomenon (degeneration of the nucleus pulposus) but not with osteoporosis and vertebral compression. Anatomically and functionally, this may be the most common form of degeneration at the discovertebral joint end plate. Further study will be necessary to clarify the process.

Previous neutron measurements in the mixed magnetic system, CsMn1-xCoxCl3·2H2O have been extended to samples with x = 0.035, 0.05 and 0.075. In this system two kinds of magnetic ions with competing orthogonal spin anisotropies are randomly distributed. The ordering temperatures TN (x are clearly detected through the appearance of magnetic Bragg reflections. However, there are no indications for the existence of any other phase transition under the experimental conditions. The observed magnetic phase below TN (x) corresponds to an oblique antiferromagnetic phase predicted for such a system.

Four rhesus monkeys were trained to perform visually guided wrist tracking movements (50). While they performed tasks by wrist flexion or extension from a neutral position, simple-spike (SS) and complex-spike (CS) discharges of a single Purkinje cell (P-cell) were recorded from intermediate and lateral parts of cerebellar hemispheres (lobules IV to VI) ipsilateral to the task-performing wrist. Of approximately 400 P-cells observed, 215 (54%) significantly increased or decreased their SS discharge rate during task performance (task-related P-cells). Of these, 161 were selected for analysis of CS activity; in these P-cells, we could reliably discriminate between CS and background SS by a spike discriminator. The 161 P-cells were further classified into response locked (n = 65) and poorly locked (n = 96) cells according to temporal coupling of the SS frequency modulation to the onset of wrist movements. About 60% of the response-locked P-cells showed a phasic increase (statistical significance level: P less than 0.01) of CS firing rate at the onset of wrist tracking movement. In a few P-cells, a phasic decrease (statistically insignificant) of CS firing rate was observed with the wrist movement. In most P-cells, an increase of CS firing rate was observed with both rapid- and slow-tracking wrist movements. The increase was larger with faster step-tracking movement than with slower ramp-tracking movement. In most P-cells, the CS activity increased with both wrist flexion and extension; in some cells, however, it increased only with either flexion or extension. In most of the response-locked P-cells, the increase of CS firing rate occurred during motor time, i.e., after the onset of the EMG change in prime movers and before the beginning of wrist tracking movement. The increase occurred phasically at the onset and/or at the recovery phase of SS frequency modulation. At neutral wrist position, the maintained frequency of the CS was 0.72 +/- 0.29 CS/s (mean and SD for 161 task-related P-cells). Compared with the frequency at neutral position, the CS frequency did not change tonically during maintained flexed or extended wrist position in any response-locked P-cells. There was no increase of CS firing rate when the monkey returned the handle to center position after completing the tracking task, even in P-cells that had shown a significant increase of CS activity during tracking.(ABSTRACT TRUNCATED AT 400 WORDS)

Cysteine-conjugate beta-lyase (EC 4.4.1.13) was purified about 880-fold from human liver obtained post mortem. The purification procedure included (NH4)2SO4 precipitation, chromatography on DEAE-cellulose and hydroxyapatite, gel filtration on Sephadex G-200, and chromatofocusing. The purified enzyme cleaves the C-S bond of several S-aryl-L-cysteines to yield equimolar amounts of thiols, pyruvic acid and ammonia via an alpha beta-elimination reaction. The Mr of the enzyme was estimated to be 88,000 by gel filtration. The enzyme is thermolabile, has a pH optimum of 8.5, and an apparent Km of 0.7 mM towards S-(p-bromophenyl)-L-cysteine. The enzyme requires pyridoxal 5′-phosphate as a cofactor, and hence the enzyme activity was completely abolished by hydroxylamine. No effect of EDTA or thiol-blocking reagents was observed on the activity of the enzyme.

The effect of alpha-human atrial natriuretic factor (alpha-hANP, 10(-6) M- 10(-8) M) on basal, and maximum angiotensin II (AII, 4.8 X 10(-8) M)-, ACTH (4.3 X 10(-9) M)-, and potassium (8mM)-stimulated levels of corticosterone, 18-hydroxycorticosterone (18-OHB) and aldosterone production were studied in adrenal glomerulosa cells from spontaneously hypertensive rats (SHR) at 14 weeks of age as compared to those in the age-matched Wistar-Kyoto rats (WKY) on a normal sodium diet. Plasma corticosterone, 18-OHB and aldosterone levels and the aldosterone response in vitro to the graded doses of AII were similar in SHR and WKY. Basal, and maximum AII-, ACTH-, and potassium-stimulated levels of corticosterone, 18-OHB and aldosterone also were similar in the cells from SHR and WKY. alpha-hANP similarly inhibited basal and stimulated levels of these corticosteroids in the cells from SHR and WKY. These results indicate that the inhibitory effect of alpha-hANP on aldosteronogenesis is unaltered in SHR at 14 weeks of age on a normal sodium diet.

Micronuclei time response and the effects of multiple treatments of mutagens on induction of micronuclei were studied. In the time-response investigation, mice were treated once with each of 5 mutagens, then killed at various times. The bone marrow was examined for the presence of micronucleated erythrocytes (MNEs). The maximal frequencies for MNEs occurred around 30 h post treatment for all mutagens tested. To examine the effects of multiple treatments, the frequencies of MNEs observed after a single- or a 5-treatment schedule were compared for 9 mutagens. Both treatment schedules were equally sensitive in detecting alkylating agents and spindle poisons, whereas the 5-treatment schedule was more sensitive for anti-metabolites. The 5-treatment schedule was particularly effective for detecting the anti-metabolites 5-fluorouracil and methotrexate, which require longer than 30 h to induce micronuclei (Maier and Schmid, 1976). These results suggest that it is practicable to sample at 30 h in the single-treatment schedule, and seem to support the usefulness of the 5-treatment schedule in screening tests.

A 53-year-old man with retinitis pigmentosa, who had two years' complaints of general malaise and muscle weakness, noticed occasional attacks of the cramps of the lower legs about three months prior to admission. At that time, hypocalcemia (7.6 mg/dl) and hyperphosphatemia (5.2 mg/dl) were pointed out. On admission, serum potassium was high-normal or high (4.4 - 4.9 mEq/l). Endocrinological studies revealed the findings of pseudohypoparathyroidism (PHP) type II, including a normal urinary cyclic AMP but blunted phosphaturic response to synthetic human parathyroid hormone (PTH), a high level of serum amino-terminal fragment of PTH with a low level of serum calcium and its ionized form, and a high-normal level of nephrogenous cyclic AMP. This patient also had selective hypoaldosteronism, as shown by intermittent hyperkalemia, low plasma and urinary levels of aldosterone and normal glucocorticoid levels. Plasma renin activity was normal but responded to a greater extent to furosemide plus upright posture. Plasma aldosterone was low and responded poorly to furosemide plus upright posture and graded angiotensin II infusions. The possible explanations for the association of PHP type II and selective hypoaldosteronism in this patient with retinitis pigmentosa are discussed.

NADP-dependent formate dehydrogenase (NADP+) (EC 1.2.1.43) from Clostridium thermoaceticum has been purified to a specific activity of about 1100 mumol min-1 mg-1 when assayed at 55 degrees C and pH 7.5. The enzyme is extremely oxygen-sensitive and 7.6 microM of O2 causes 50% inhibition of initial velocity under assay conditions. Purification was done in an atmosphere at 95% N2 and 5% H2 and by including azide, dithionite, and glycerol as stabilizing agents in all buffer solutions. The enzyme contains, in molar ratios, 2 tungsten, 2 selenium, 36 iron, and about 50 inorganic sulfur. It has a molecular weight of about 340,000 and consist of two each of two different subunits giving the composition alpha 2 beta 2. The molecular weight of the alpha-subunit is 96,000 and that of the beta-subunit is 76,000. The selenium resides in the two alpha-subunits. Tungsten is released from the protein on denaturation and may exist as a tungsten cofactor. The enzyme catalyzes a reduction of CO2 with NADPH at pH 7.5 and 55 degrees C and Keq at these conditions is (2.35 +/- 0.49) x 10(-2) if CO2 is considered the active species and (1.48 +/- 0.31) x 10(-3) if HCO3- is the active species.

Properties of human atrial natriuretic factor (ANF) binding to the crude membrane fraction of rat kidney were studied using the ANF-radiolabeled receptor assay; the developmental change of renal ANF receptors in three age groups of spontaneously hypertensive rats (SHR) was also investigated with the methods of radiolabeled receptor assay and the quantitative approach of in vitro macro-autoradiography. Temperature and incubation time greatly influenced ANF binding capacities because of the degradation of radiolabeled ligand. Addition of 5 mM MgCl2 to assay buffer was useful for the stabilization of ANF specific binding. Scatchard analysis suggested that the crude membrane fraction of rat's kidney had a single binding site with the apparent dissociation constant of 0.55 nM. In the study of the developmental change of renal ANF receptor in SHR, systolic blood pressure of the SHR at the age of 5 weeks and 12 weeks was significantly higher than that of age-matched Wistar-Kyoto (WKY) rats, but there was no significant difference in blood pressure between SHR and WKY rats at the age of 3 weeks. Concerning the radiolabeled receptor assay of ANF, the apparent dissociation constant and maximum binding capacity in SHR were low in all age groups when compared with those of WKY rats. In the in vitro macro-autoradiographic observation, the specific binding of ANF was localized mainly in the renal cortex, and these binding patterns of SHR and WKY rats were the same in all age groups.(ABSTRACT TRUNCATED AT 250 WORDS)

A low-permittivity two-level interconnection process is presented. The key features of this process are the use of a low dielectric constant SiBN interlayer and the adoption of planarization using a two-stage etch-back process. The SiBN film is characterized from the standpoint of its device applications. The two-level interconnection process flow is described in detail. The effect of the SiBN interlayer in reducing the second wiring capacitance is compared to that of a conventional silicon nitride interlayer. This is demonstrated by fabricating a 33-stage ECL ring oscillator and a 2.1 kG macrocell array LSI. >

The effect of three new fluoroquinolones on theophylline kinetics and the urinary excretion of metabolites was studied in 5 healthy subjects (3 male, 2 female). All subjects received serial, single i.v. infusions of theophylline (aminophylline, 250 mg) over 60 min after 200 mg doses of a quinolone (enoxacin, ofloxacin, norfloxacin) every 8 h for 3 consecutive days, the quinolone being administered up to the day following theophylline administration. Pretreatment with ofloxacin and norfloxacin did not influence theophylline disposition, but theophylline clearance fell from 0.054 to 0.027 l.h-1.kg-1 in the presence of enoxacin, without a change in the apparent volume of distribution. Enoxacin, too, was the sole compound to increase the urinary excretion of theophylline (33.2 vs 43.9 mg, before vs after treatment), and significantly to decrease the excretion of 3-methylxanthine (3-MX), 1-methyluric acid (1-MU) and 1,3-dimethyluric acid (1,3-DMU) in 24-h urine samples (from 19.8 to 7.16 mg, from 28.3 to 10.3 mg and from 68.8 to 49.5 mg, respectively). The effect of the quinolones on hepatic drug metabolizing enzyme activity was investigated in each subject using the ratios of 6-hydroxycortisol to total 17-hydroxycorticosteroids and to free cortisol in 24-h urines as an index of the hepatic P-450-dependent enzyme system. No significant difference in ratio was observed between control and other treatments. It is concluded that the theophylline-enoxacin interaction was largely due to inhibition of a metabolic system other than the common hepatic P-450 system.

Magnetic resonance imaging of acute spinal cord injury is described. The traumatized cord segment was clearly shown as a hyperintensity in a T2-weighted image whereas it appeared as an isointensity in a moderately T1-weighted image. This different sensitivity may result from parenchymal hemorrhagic tissue and edematous changes due to direct trauma. Hyperintense tissue was also seen in the retro-pharyngeal and -tracheal spaces.

The effect of CO2 laser light on the excited F centre in KBr has been investigated at 80K by monitoring the F emission band. Under the action of CO2 laser light on F centres excited with F light a remarkable decrease of the emission intensity was observed, whereas no changes of the peak energy and linewidth were observed. If any new emission band was induced by the CO2 laser light it was not detected within the limits of experimental error. These results are interpreted by considering the non-radiative decay from the higher excited state in the relaxed configuration to the 1s ground state.

Human myeloma cells were purified from bone marrow aspirates from four patients having advanced myeloma, including one with common acute lymphoblastic leukemia antigen-positive myeloma. All of these myelomas had marked bone lytic lesions. From the culture supernatants of these purified myeloma cells, bone-resorbing activities were significantly revealed by 45Ca-release bone resorption assay, and IL-1 activities were also detected by IL-1 bioassay (mouse thymocyte comitogenic assay). Sandwich enzyme immunoassay for IL-1 alpha or IL-1 beta revealed that IL-1 beta was responsible for IL-1 activity of these culture supernatants. Furthermore, the bone resorbing activities of these culture supernatants were completely neutralized by pretreatment of anti-IL-1 beta, but not anti-IL-1 alpha antibody. By Northern blot analysis, IL-1 beta mRNA was identified from these myeloma cells. Therefore, it is concluded that myeloma cells produce IL-1 beta, which acts as bone-resorbing activity in multiple myeloma.

Characteristic alterations at the surface of chick embryo cells infected with the HF-TC strain of rabies virus and the binding sites of hemadsorption were studied employing both scanning and transmission electron microscopes. The initial alteration of the cell surface structure revealed by scanning electron microscopy was an appearance of elongated and reticulated microvilli on the 2nd day after virus inoculation. On the 3rd day, numerous bullet-shaped virions could be seen budding as single, tetrapod-like structures and as radial projections both from the perikarya and microvilli. Thereafter, elongation of microvilli, formation of numerous blebs in various sizes, disappearance of filopodia, and rounding up of infected cells were observed as characteristic cytopathic effects by rabies virus infection. The attachments of goose erythrocytes to the infected cells occured in two forms. The one was adsorption of erythrocytes to the cell surface involving microvilli and filopodia in the absence of detectable virus, and the other was adsorptio n of erythrocytes to the virus particles budding from cell surface. The former could be seen from the early stage of infection through the end of observation period, while the latter was observed only on and after the 3rd day after virus inoculation. These findings were also confirmed with transmission electron microscopy.

An efficient separation of corticosteroids in plasma of rats was obtained by reversed-phase high-performance liquid chromatography (HPLC). Plasma corticosteroid assays with HPLC separation were used to determine the circadian rhythm of 18-hydroxycorticosterone (18-OHB) and its possible relationship to aldosterone or corticosterone in conscious rats under standard conditions (regular diet; 12-hour light and 12-hour dark cycle). Significant circadian rhythms of plasma corticosterone, 18-OHB and aldosterone were observed with peak values at 20.00 h and nadir values at 08.00 h. The mean ratio of plasma 18-OHB to aldosterone during 24 h was 2.4. The circadian rhythm of 18-OHB was also correlated with that of plasma aldosterone or corticosterone.