Mechanisms of caffeine-induced contraction and relaxation of rat aortic smooth muscle

1. Using front-surface fluorimetry and Fura-2, we determined the effects of caffeine on cytosolic calcium concentration ([Ca2+]i) and on tension of strips of the rat thoracic aorta. We also determined the effects of caffeine on 45Ca2+ influx into the strips. The objective was to elucidate the mechanism of contraction and relaxation in vascular smooth muscle, as induced by caffeine. 2. In normal physiological salt solution (PSS), caffeine induced a transient tension development, while it induced a biphasic change in [Ca2+]i. The initial transient peak in [Ca2+]i which coincided with tension development was followed by a sustained increase. Thus, changes in tension did not follow changes in [Ca2+]i. In Ca(2+)-free PSS, both the caffeine-induced contraction and the increase in [Ca2+]i were transient. It was suggested that in both the presence and absence of extracellular Ca2+, the transient increase in [Ca2+]i was due to the release of Ca2+ from the intracellular store. Although the sustained increase in [Ca2+]i depended on extracellular Ca2+, it was not affected by diltiazem, a Ca2+ antagonist. 3. Caffeine inhibited the increase in [Ca2+]i and tension development during 118 mM-K+ depolarization, in a concentration-dependent manner. The extent of reduction in tension (relaxation) was greater than that expected from the reduction in [Ca2+]i based on the [Ca2+]i-tension relationship observed with K+ depolarization. Pretreatment of the strips with ryanodine did not alter the inhibitory effects of caffeine. 4. Caffeine inhibited the increased [Ca2+]i and developed tension during stimulation by 10(-5) M-noradrenaline, in a concentration-dependent manner. 5. Dibutyryl cAMP (10(-4) M) inhibited both high K(+)-induced and noradrenaline-induced tension development. Inhibition of an increase in [Ca2+]i in relation to the inhibition of tension during noradrenaline stimulation was much greater than that in 118 mM-K+ depolarization. 6. Although caffeine per se had no effect on 45Ca2+ influx in the strips in normal PSS, caffeine did inhibit the increase in 45Ca2+ influx stimulated by 118 mM-K+ or by 10(-5) M-noradrenaline, to a similar extent and with similar IC50 values. 7. The characteristic features of the effects of caffeine on vascular smooth muscle, i.e. the transient nature of contraction and the relaxation of precontracted strips could be explained as follows: caffeine is able to reduce [Ca2+]i after releasing Ca2+ from intracellular stores; however, this may play a minor role. Independent of the [Ca2+]i reduction, the second messenger, cAMP, might directly influence the [Ca2+]i-tension relationship, and if so, would play a major role.

[Ocular penetration of UF-021, a new prostaglandin related compound, in the rabbit eye]

The ocular penetration and pigment affinity of topically applied UF-021, a newly developed prostaglandin-related compound, were investigated in rabbit eyes using 3H-labeled UF-021. Ten minutes to 24 hours after instillation of 0.12% of 3H-UF-021 solution into New Zealand white or pigmented rabbit eyes, the rabbits were sacrificed and the eyes were immediately enucleated. The extraocular muscles, conjunctiva, aqueous humor, cornea, iris, anterior and posterior sclera, ciliary body, lens, vitreous, retino-choroid complex, optic nerve were separated and blood samples were taken. The concentration of 3H-UF-021 in each sample was determined with a liquid scintillation counter. The peak concentration of UF-021 was obtained at 40 minutes and 1 hour after instillation in the iris-ciliary body and aqueous humor of albino rabbit. According to the pharmacokinetic analysis of the data, UF-021 showed good ocular penetration into the rabbit eye, and the permeability of the epithelial barrier for UF-021 was calculated to be 2.9 x 10(-3) cm/hr. The apparent elimination rate constant and the apparent absorption rate constant were also calculated to be 0.21 hr-1 and 1.28hr-1, respectively. The time course for 3H-UF-021 concentration in the eye of pigmented rabbit was almost the same as that in the eye of non-pigmented rabbit, indicating that UF-021 did not bind to pigmented tissues.

The micronucleus test of benzo[a]pyrene with mouse and rat peripheral blood reticulocytes

The micronucleus test using peripheral blood reticulocytes (RETs) was evaluated in CD-1 and BDF1 mice and Sprague-Dawley rats treated with benzo[a]pyrene at two independent laboratories. The maximum incidence of micronucleated reticulocytes (MNRETs) appeared in both strains of mice 48 h after the treatment; interlaboratory differences were small. The incidence of MNRETs in BDF1 mice was higher than in CD-1 mice. In rats, significant increases of MNRETs with the maximum response at 72 h were detected when B[a]P was administered i.p.; slight but significant increases were observed at 24 h or later, with the maximum at 24-48 h, when it was administered p.o. These results suggest that the new method for the micronucleus test using circulating RETs will be useful in the detection of the clastogenicity of chemicals.

Influence of water on the transverse strength of posterior composite resins

In an attempt to evaluate the influence of water on the mechanical properties of composite resin, the transverse strengths of 15 commercially available composites were determined in water at 37 degrees C and compared with the strength measured in air after storage in water for periods of 1 day to 3 months. Some of the composites, including two which contained a blend filler, showed remarkable reduction of transverse strength when measured in air, according to the procedures specified in ISO 4049, in comparison with transverse strength measured in water. The change of water content in the material can predominantly affect the mechanical behavior of composite resin.

[Systolic anterior motion of the anterior mitral leaflet and/or the chordae tendinae in the elderly]

Systolic anterior motion of the anterior mitral leaflet and asymmetric septal hypertrophy (ASH) are characteristic features of hypertrophic obstructive cardiomyopathy (HOCM) on an echocardiogram. Among 9,670 patients over 60 years old examined by echocardiography from January, 1984 to October, 1990, 55 patients showed systolic anterior motion of the anterior mitral leaflet and/or the chordae tendinae (SAM). We investigated clinical features and morphological features of the left ventricle on an echocardiogram in the 55 patients with SAM. They were classified into three groups according to the degree of SAM. Thirty eight cases (group I) had no mitral and/or chordal-septal contact, 10 (group II) had brief contact (less than 30% on the echocardiographic systole) and 7 (group III) had prolonged contact (greater than or equal to 30%). Ages ranged from 60 to 99 with a mean age of 78.2 years. There were 19 males and 36 females and there was a predominance of females in each group. Thirty five cases had hypertension and 34 left ventricular hypertrophy on electrocardiograms. One case of group I, 3 of group II and 7 of group III had a clinical diagnosis of HOCM. In comparison with each group, the incidence of LVH (SV1 + RV5 greater than or equal to 35 mm) was 52% in group I, 90% in group II and 83% in group III and that of LVH (SV1 + RV5 greater than or equal to 70 mm) was 29%, 20% and 67%, respectively. On echocardiographic examination, the diastolic descent rate of the anterior mitral leaflet in the 3 groups was 36.1 +/- 13.1 mm/sec, 19.4 +/- 13.1 mm/sec and 10.7 +/- 11.8 mm/sec (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Gastric mucosa in female patients with fundic glandular polyps

To evaluate the characteristics of the gastric mucosa in women with fundic glandular polyps, we examined gastric acid secretion, fasting serum levels of pepsinogen I and gastrin, and gastric histology in 11 female patients with fundic polyps, and compared the results with 30 female controls without endoscopic abnormalities and 50 female patients with gastric foveolar hyperplastic polyps. No significant difference was found in gastric and secretion and fasting serum levels of pepsinogen I and gastrin between the patients with fundic glandular polyps and the control subjects. Histological examination showed that atrophic gastritis was generally not found in the patients with fundic glandular polyps. In contrast, gastric acid secretion and fasting serum levels of pepsinogen I were significantly lower and serum gastrin levels were significantly higher in the patients with foveolar hyperplastic polyps than in the other two groups. Also, patients with foveolar hyperplastic polyps had a higher prevalence and further advanced atrophic gastritis in the fundus than did the other two groups. Our investigations demonstrated that fundic glandular polyps arise from gastric mucosa without atrophic gastritis, whereas foveolar hyperplastic polyps develop from mucosa affected by atrophic gastritis, especially type A gastritis.

Lack of correlation between P pulmonale and right atrial overload in chronic obstructive airways disease

The correlation between P pulmonale and right atrial overload in chronic lung disease was studied. Right atrial pressure, pulmonary artery pressure, and cardiac output were measured with a Swan-Ganz catheter in nine patients with chronic lung disease and P pulmonale on the electrocardiogram (P wave amplitude of greater than or equal to 2.5 mm (0.25 mV) in leads II, III, and a VF. The results were compared with those in six patients with an atrial septal defect (left to right shunt greater than or equal to 50%) and six patients with pulmonary hypertension (mean pressure greater than or equal to 30 mm Hg without left sided heart disease). Right atrial volume and wall thickness were measured in 10 cases of P pulmonale among 1000 necropsy cases and compared with 141 normal hearts from the same series. The patients with P pulmonale did not show a significant increase in right atrial or pulmonary artery pressures. None of the patients with an atrial septal defect or pulmonary hypertension had P pulmonale on the electrocardiogram. In the necropsy cases of P pulmonale mean (1 SD) in right atrial volume (32 (12) ml) and wall thickness (1.5 (0.7) mm) were not significantly increased (40 (14) ml and 1.4 (0.5) mm in the normal hearts). There was a significant inverse relation between the presence of P pulmonale and the cardiothoracic ratio. In all the patients with P pulmonale chest x ray showed a low cardiothoracic ratio, a considerably depressed diaphragm, and a pendulous heart. This study showed no correlation between P pulmonale and right atrial overload in chronic lung disease. A more vertical anatomical position of the heart, particularly of the right atrium, seems to be the major factor responsible for generation of P pulmonale in chronic airways disease.

A change in the spontaneous release of endogenous acetylcholine from rat striatal slices after repeated injection of haloperidol

The spontaneous and 50 mM K(+)-stimulated release of endogenous acetylcholine (ACh) from rat striatal slices was measured to investigate an adaptive change of striatal ACh after a withdrawal period for 24 h from chronic treatment of the rat with haloperidol. The haloperidol injections (2.5 mg/kg/day) for a period of 3, 7 or 14 days all reduced the spontaneous release of ACh significantly by 20-50% without changing tissue levels of ACh. On the contrary, these treatments produced a very small (by about 10%) but significant increase in K(+)-stimulated release except for the treatment of 7 days. These results suggest that the spontaneous ACh release is under the control of a dopaminergic mechanism, which might be different from the mechanism controlling the evoked release of ACh and emerges following withdrawal from chronic haloperidol treatment.

Toxicity modification of sodium selenite by a brief exposure to heat or cold in mice

The effect of a brief exposure to heat/cold on the subsequent development of toxicity of sodium selenite (SS) was evaluated in male ICR mice. Mice were exposed to one of three ambient temperatures (Ta; approx. 8 degrees, 22 degrees and 33 degrees C). One and a half hours after the beginning of the exposure, they were injected with 45 mumol/kg of SS subcutaneously. The exposure was terminated 3 h after injection and the mice were returned to Ta of 22 degrees C. Heat-induced enhancement of toxicity was recognized in some plasma enzyme activities 3 days after injection and in the suppression of body weight for up to 3 weeks. On the other hand, cold exposure alleviated SS toxicity in terms of these indices. Thus, the Ta during this short period was recognized to be important in determining subsequent development of SS toxicity. At the end of the thermal exposure, heat increased renal concentration of the injected Se. On the other hand, in the liver and the other organs examined, the highest Se concentration was found in the cold-exposed group, followed by the control (room temperature) and the heat-exposed. The relation between the modification of toxicity and the altered distribution was not clear. Neither glutathione level in the liver nor that in the kidney at the time of SS injection could explain the observed modification of the toxicity.

[A clinical study of hypertrophic obstructive cardiomyopathy in the elderly]

Seven elderly patients with hypertrophic obstructive cardiomyopathy (HOCM), who had the three following characteristics on echocardiograms 1) extremely thickened septum, 2) systolic anterior motion of the mitral valve, 3) mid systolic semi-closure of the aortic valve, were clinically evaluated. Ages ranged from 73 to 86 years old (average 78.9% yr.) and all were women. None had not a family history of hypertrophic cardiomyopathy but they had mild hypertension. Six patients showed a significant high voltage on the ST-segment and T-wave abnormalities ("strain" pattern). The left ventricular posterior wall as well as the septum was thickened in 5 and the remaining 2 showed asymmetrical septal hypertrophy (ASH) on echocardiograms. The left ventricular cavity was narrowed due to left ventricular hypertrophy and the shape of the left ventricular cavity was ovoid in all patients. The aorto-septal angles in these 7 patients were 80 degrees to 120 degrees. In addition, proximal septal bulge in all and anterior displacement of the mitral posterior leaflet due to the mitral ring calcification (MRC) in some patients contributed to the narrowing of the left ventricular outflow tract, and the mitral valve was pulled up toward the septum because of the good left ventricular systolic function (ejection fraction: 70 to 94% by echocardiography) and blood was ejected at a high velocity through a narrowed outflow tract (Venturi effect). Pressure gradients in the left ventricular outflow tract was 38 to 146 mmHg in 5 examined by cardiac catheterization. Biopsy specimens were obtained from 2 patients, showing hypertrophic myocytes (diameter: 20 to 30 micron) in 2 and mild disarray in 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Possible role of cementoblasts in the resorbant organ of human deciduous teeth during root resorption

Human deciduous teeth undergoing physiologic root resorption were extracted and fixed with a mixture of formaldehyde and glutaraldehyde and processed for scanning (SEM) and transmission (TEM) electron microscopy, and for acid (ACPase) and alkaline phosphatase (ALPase) cytochemistry. The resorbant organ, rich in odontoclasts, cementoblasts, fibroblasts, and macrophages, formed prominent resorption lacunae in root dentin. SEM observations of resorption lacunae treated with trypsin solution showed islands of newly-formed cementum matrix in part of the resorbing dentin surfaces. Such cementum consisted of bundles of densely-arranged collagen fibrils and, in part, contained forming cementocytic lacunae and canaliculi. Active cementoblasts adjacent to odontoclasts on resorbing dentin surfaces showed cuboidal outlines and were characterized by the presence of numerous cisterns of rough endoplasmic reticulum, well-developed Golgi complexes, secretion granules, and many mitochondria. They sometimes formed a thin layer of cementoid and/or cementum matrix upon the resorbing dentin surface. These cementoblasts had ACPase-positive lysosomes in the cell bodies and exhibited intense ALPase activity along the plasma membranes of whole cell surfaces. These results suggest that, during root resorption, 1) active cementoblasts are present adjacent to active odontoclasts and 2) these cementoblasts are involved in remodeling the resorbing dentin surfaces.

Modification by nickel of instrumental thermoregulatory behavior in rats

The effects of NiCl2 on the colonic temperature and thermoregulatory behavior (TRB) of rats were examined. TRB was evaluated in an instrumental (operant) setting in which rats were required to press a level to obtain convectional heat (SEEK) or to avoid heat (ESCAPE). Orthogonal polynomial regression was used to describe the response patterns in both the SEEK and ESCAPE situations. Two milligrams per kilogram of Ni (ip) caused rapid, transient hypothermia at an ambient temperature of 21 degrees C. When given access to heat reinforcement, rats responded for heat at a lower rate immediately after 2 or 5 mg/kg of Ni (up to 5-15 min) than after saline. Subsequently, response rates rose 30 min or more after Ni injection. A converse pattern was found with the heat escape situation. These observations, confirmed by two contrasting procedures, indicate that the changes were thermoregulatory in nature and cannot be explained by nonspecific suppressive or excitatory effects of Ni. They further suggest that Ni-induced hypothermia results from an altered body temperature set point. The subsequent reversal in behavior probably arises from a direct action of Ni on autonomic effector mechanisms. The origin and biological significance of these findings require further investigation. Physical requirements and response topography are discussed as critical variables in the interpretation of experiments requiring similar responses under different ambient temperatures.

Transient hypothermia and hyperphagia induced by selenium and tellurium compounds in mice

The effects of sublethal doses of selenite, selenate, selenocystine (Se-Cys) and selenomethionine (Se-Met) as well as of tellurite on body temperature and feeding behavior were examined in male ICR mice. Ten or 30 mumol/kg of chemicals were injected subcutaneously and body temperature was measured up to 4 h. In a separate experiment, the gastric content was weighted 4 h after injection. All chemicals except Se-Met induced both hypothermia and hyperphagia, suggesting that: (a) these two effects are related to each other; (b) among the chemicals tested, Se-Cys appears to be the most potent hypothermia inducer; (c) Se-Met is unique in that it has neither effect.

Cellular roles in physiological root resorption of deciduous teeth in the cat

This study has attempted to assess the importance of mesenchymal cells, fibroblasts, cementoblasts, and mononuclear phagocytes (i.e., macrophages) in physiological root resorption of feline deciduous teeth. Deciduous incisors of three- to six-month-old kittens undergoing root resorption were investigated by means of electron microscopy. In an early phase of root resorption, the resorption organ consisted of many fibroblasts and relatively few macrophages and odontoclasts, the last with a wide, clear zone and narrow, immature, ruffled border. In the active phase of root resorption, the resorption organ contained many odontoclasts with a well-developed ruffled border and a reduced clear zone, cementoblasts, fibroblasts, macrophages, neutrophils, and many blood vessels. Cementoblasts were present usually on the resorbing dentin surface adjacent to odontoclasts and, in many cases, these cells communicated with each other via gap junctions. Cementoblasts frequently extended broad cell processes with secretion granules and with phagosomes containing collagen fibrils into the dentinal tubules exposed to resorption lacunae. Some macrophages exhibiting a clear zone-like structure also appeared on resorbing dentin surfaces. In the resting phase of root resorption, the dentin surface was covered mostly with cementoblasts resembling bone lining cells. There was an occasional macrophage, but no odontoclasts were observed during this phase. During removal of the periodontal ligament concomitant with root resorption, many fibroblasts phagocytosed mature collagen fibrils, as well as amorphous fluffy material. These results suggest that these mesenchymal cells, as well as odontoclasts, are essential for the cellular removal of dental hard and soft tissues during shedding of feline deciduous teeth.

Stenotic lesions and length of the left main coronary artery in the aged

To evaluate lesions of the left main coronary artery (LM) in the aged, a pathologic study was performed on a total of 972 consecutive autopsy cases over 60 years of age. The study population consisted of 503 men and 469 women with an average age at death of 79.0 years. In this study the degree of narrowing and length of the LM were evaluated in all cases (T), and the 141 cases with normal hearts (N) were compared with the 202 cases with myocardial infarction (MI). The following results were obtained: (1) the average coronary stenotic index (CSI) was 9.1/15 in T, 5.8/15 in N and 11.2/15 in MI (N less than MI, p less than 0.001), (2) the grade of narrowing in the LM (LMG), when 100% obstruction of the LM is counted as 5, was 1.8 +/- 0.9 in T, 1.3 +/- 0.6 in N and 2.3 +/- 1.1 in MI (N less than MI, p less than 0.001). Cases showing more than 75% narrowing of the LM were found in 58 (6%), of which 35 cases belonged to MI, but development of MI directly due to lesions in the LM was found in only 9 patients (4.5% among MI), (3) the average length of the LM (LML) was 9.4 +/- 4.4 mm in T, 9.0 +/- 4.2 mm in N and 9.3 +/- 3.8 mm in MI (N vs MI; n.s.). Cases presenting left coronary artery dominance (n = 82) or a balanced type (n = 159) showed shorter LML than those with right coronary artery dominance (n = 729) (8.5 +/- 4.0 mm, 8.8 +/- 4.6 mm and 9.7 +/- 4.4 mm, respectively, p less than 0.05), (4) in T there was a correlation between the LMG and CSI, but not between the LML and CSI. In conclusion, lesions of the LM in the aged were generally mild and the LMG showed a positive correlation with CSI and the narrowing of each coronary branch, while no relationship was noted between the LML and CSI.

A case of benign cementoblastoma

A rare case of benign cementoblastoma is reported. Active cementoblasts adding cementoid tissue were observed histologically by means of specific staining for unmineralized matrix of hard tissue. A polarizing microscope and an x-ray diffractometer were used to clarify the cementum-like tissue of benign cementoblastoma. The collagen bundles of tumor tissue showed irregular and random arrangements under polarized light. The qualitative analysis revealed that the mineralized component was composed of low-crystalline hydroxylapatite.

A clinicopathologic study of the accessory bypass tracts in six cases of Wolff-Parkinson-White syndrome

A clinical and histologic correlation study was conducted to examine the accessory bypass tracts in 6 cases of Wolff-Parkinson-White syndrome. (1) Types A, B (Rosenbaum) and C (Ueda) were found in 2 cases each. From the polarity of the delta waves, the site of the bypass tract was assumed to be in the left posterior and left lateral free wall in type A, the right lateral and right posterior paraseptal regions in type B and in the right posterior paraseptal and right anterior paraseptal areas in type C. (2) In 6 cases 19 bypass tracts were found, consisting of 18 Kent bundles and 1 Mahaim fiber, from a total of 146,400 serial sections. The site of the bypass tract was the left lateral and left posterior walls in 2 type A cases, and the right lateral and right posterior walls in 2 type B cases, with good correspondence to our assumption. In both type C cases it was biventricular, composed of left posterior paraseptal and right lateral regions with an additional Mahaim fiber in 1 case. (3) A total of 46 cases of WPW syndrome were collected from the literature and the present paper; they consisted of 16 cases of type A, 20 of type B, 4 of type A + B and 6 of type C. Seventy % of type A cases showed a bypass tract in the left heart, and 64% of type B in the right heart. In 6 cases of type C, the bypass tract was found in various sites and in various combinations, requiring further investigation.

Cytodifferentiation and degeneration of odontoclasts in physiologic root resorption of kitten deciduous teeth

To investigate the cytodifferentiation and degeneration of odontoclasts in physiologic root resorption, we studied deciduous incisors undergoing resorption in 6-month-old kittens by electron microscopy of ultrathin sections. The endogenous peroxidase activity within the cells was also examined by incubating the tissue slices in diaminobenzidine-H2O2 medium. The resorbing tissues, consisting of multinucleated giant cells, macrophages, granular leukocytes, fibroblasts and many blood vessels, were observed at the resorbing surface of the root dentine. Macrophages and granular leukocytes exhibited endogenous peroxidase activity, but mononuclear and multinucleated preodontoclasts and multinucleated odontoclasts did not. These preodontoclasts contained abundant mitochondria, a moderate amount of rough endoplasmic reticulum, stacks of Golgi membranes, lysosomes and numerous polyribosomes scattered throughout the cytoplasm. Many cellular processes extended from their cell surfaces by which the preodontoclasts appeared to fuse to one another during their multinucleation. Concomitant with the multinucleation process, the preodontoclasts developed numerous pale vacuoles throughout the cytoplasm. These vacuoles seemed to arise from some smooth endoplasmic reticula, perhaps representing Golgi-endoplasmic reticulum-lysosome, and the Golgi saccules. However, the preodontoclasts did not yet form a ruffled border and clear zones. When these preodontoclasts came into direct contact with resorbing dentine surfaces, they began to form the clear zones against dentine surfaces. Characteristically, numerous pale vacuoles were accumulated in the cytoplasm adjacent to the clear zone, then they penetrated into the cytoplasm of the clear zone, and with this, ruffles of the plasma membranes appeared. Through a further movement of more pale vacuoles towards the ruffled plasma membranes, the odontoclasts developed typical ruffled borders against the resorbing dentine surfaces. At this differential phase, little pale vacuoles appeared in the Golgi area, but the cisterns of the Golgi apparatus themselves reached their greatest extent during cellular differentiation. Fully differentiated odontoclasts frequently extended long broad cellular processes into the dentinal tubules exposed to the resorption lacunae. Although some odontoclastic processes penetrating the dentinal tubules contained vacuoles and lysosomal structures, most processes lacked any cytoplasmic organelles, and their cytoplasm resembled that of the clear zone. But these processes never exhibited ruffled-border-like structures.(ABSTRACT TRUNCATED AT 400 WORDS)

Dentin resorption mediated by odontoclasts in physiological root resorption of human deciduous teeth

Extracted human deciduous teeth undergoing physiological root resorption were fixed with a mixture of formaldehyde and glutaraldehyde and processed for scanning (SEM) and analytical transmission electron microscopy, as well as acid trimetaphosphatase cytochemistry. The granulated tissues, which are rich in multinucleated odontoclasts and capillary vessels, formed various resorption lacunae on the resorbing dentin surfaces. SEM observations of dentin surfaces treated with sodium hypochlorite revealed two types of resorption lacunae: deep, round lacunae in which the peritubular matrix of dentinal tubules was strongly dissolved; and shallow, irregular lacunae with intact peritubular matrix. In trypsin-treated materials, the resorption surfaces were characterized by the presence of numerous collagen fibers in both the peritubular and intertubular matrices, suggesting demineralization of the surface dentin. Odontoclasts were characterized by the presence of abundant mitochondria, perinuclear stacks of Golgi membranes, various lysosomes, numerous endocytotic vacuoles, and a well-developed ruffled border against the resorption lacunae. Most endocytotic vacuoles were distributed in the cytoplasm between the ruffled border and the nuclei. In undemineralized ultrathin sections, the surface dentin of resorption lacunae consisted of collagen fibers and apatite crystals and had a lower packing density than those in unresorbed, deeper dentin. Many apatite crystals were demonstrated to be present in the extracellular channels of the ruffled border and in adjacent endocytotic vacuoles derived from it. Lysosomes located in the perinuclear cytoplasm of odontoclasts contained amorphous dense material and/or a small amount of crystals. An energy-dispersive x-ray microanalysis of apatite crystals in undemineralized sections indicated that the energy spectrum peaks of Ca and P detected from crystals in resorbing dentin were much lower than those in unresorbed dentin. Similarly, lower spectrum peaks of Ca and P were obtained from crystals found in the ruffled border and endocytotic vacuoles of odontoclasts. A slight trace Ca peak also was detected in the amorphous dense material in lysosomes of odontoclasts. The enzyme cytochemistry of lysosomal acid trimetaphosphatase indicated that odontoclasts had intense enzymatic activity in the Golgi membranes, endoplasmic reticulum cisternae, lysosomes, and endocytotic vacuoles. Dense reaction precipitates of enzymatic activity also were found along the dentin surfaces of resorption lacunae occupied by odontoclast ruffled borders.(ABSTRACT TRUNCATED AT 400 WORDS)

Modification of lethal, hypothermic and hyperphagic effects of sodium selenite by reduced glutathione in mice

The effects of co-administration of reduced glutathione (GSH) on the lethality of sodium selenite (SS) and on SS-induced hypothermia and hyperphagia were examined in adult male ICR mice. Tissue GSH levels after s.c. injection were also determined. In the plasma, GSH concentration was significantly elevated up to 2 h after injection of 2 mmol/kg of GSH. Little change was observed in liver, and erythrocyte levels, the lethality of SS was enhanced by a similar dose of GSH. This enhancement, however, was observed only when SS was injected during the period when plasma GSH was elevated. These results suggest that the interaction between GSH and SS in plasma was the major contributor to the enhancement of SS toxicity. Hypothermia induced by SS was also enhanced by a 60-fold dose of GSH but not by a 6-fold dose of GSH. With respect to hyperphagia, GSH suppressed the effect of SS, probably because of depressing effect of co-administration of SS an GSH.

Rapid screening method for inhibitors of protein kinase C

Specific inhibitors of protein kinase C (PKC) were screened for with a unique detection system, named bleb forming assay. When K562, a human chronic myeloid leukemia cell, was treated with phorbol 12,13-dibutylate (PDBu) or teleocidin which are activators of PKC, many blebs appeared on the cell surface of K562 within 10 minutes. This appearance of blebs is inhibited by staurosporine and H7 which are known to be PKC inhibitors. Teleocidin and PDBu did not induce bleb formation of HL60, a human acute promyelocytic leukemia cell, and the mouse Friend leukemia cell, even though their morphology was changed 24 hours after treatment with teleocidin or PDBu. Many inducers of terminal differentiation of K562 have the same effect on HL60 and Friend cells. However, the bleb inducing activity of PKC activators seems to be specific for K562. The bleb forming assay satisfied the criteria (simplicity and specificity) required for preliminary screening of activators or inhibitors of PKC. Teleocidins A and B, and tautomycin (a new antibiotic isolated in our laboratory) were identified as activators of PKC, and also staurosporine and isoflavones (daidzein and genistein) as inhibitors.

Induction of morphological change of human myeloid leukemia and activation of protein kinase C by a novel antibiotic, tautomycin

A novel antibiotic tautomycin induced many blebs on the surface of K562 human chronic myeloid leukemia cells, similar to the morphological changes induced by phorbol esters. However, tautomycin did not induce nitroblue tetrazolium reducing activity, when HL60 human promyelocytic leukemia cells were caused to differentiate by quinomycin into mature granulocytes. It did not induce spread of HL60 cells, one of the phenotypes of mature macrophages. In addition, it did not compete with phorbol dibutyrate to bind to the cell surface of K562 cells. However, tautomycin significantly activated protein kinase C (PKC) extracted from K562 cells. These results indicate that tautomycin is a new activator of PKC, distinct from phorbol esters.

Metallothionein induction by sodium selenite at two different ambient temperatures in mice

The induction of metallothionein (MT) synthesis by sodium selenite was investigated in mice with regard to the hypothermic response known to be caused by sodium selenite. Mice received a subcutaneous injection of sodium selenite at two doses (20 and 45 mumol/kg) under two ambient temperature (22 and 33 degrees C) conditions. Hepatic MT concentration was significantly increased by an injection of sodium selenite compared to the control, whereas no significant effect of ambient temperature was observed. The distribution of radiolabeled selenium was examined in vivo and in vitro. When sodium selenite was injected into mice, radiolabeled selenium was mostly eluted in a fraction larger in molecular weight than MT and was not found in a fraction corresponding to MT. When sodium selenite was added to the hepatic supernatant of the mice that had been injected with zinc sulfate, zinc in zinc-thionein was not displaced by radiolabeled selenium.

Transient hyperphagia after sodium selenite injection in mice

Injection (s.c.) of Na2SeO3 (SS, 20-30 mumol/kg) into male mice initiated eating, which began about 20 min after injection and continued for about 3 h. This initiation effect was observed for mice of different ages and at different times of the day. Other findings of this study were: (1) early morning injection (30 mumol/kg) caused increased food intake, as examined by gastric content 3 h after injection, compared to daytime injection; and (2) SS-induced transient hyperphagia was observed at ambient temperatures of 10 and 22 degrees C, but not at 37 degrees C. This paper discusses these results in relation to SS-induced hypothermia.

[Mitral regurgitation due to ruptured chordae tendineae in the aged: a clinicopathologic study]

We observed 13 cases of mitral regurgitation (MR) due to ruptured chordae tendineae (RCT) among 4,000 consecutive autopsies of patients over 60 years of age (0.33%). There were four men and nine women whose average age was 79.8 yrs. Five cases had a single RCT (Group I) and eight had multiple RCT (from two to eight chordae) (Group II). The sites of RCT were in the posterior mitral leaflet (PML) in nine, the anterior leaflet in one, and both in three. All in Group I showed RCT in the PML; the posterior scallop in two and the middle scallop in three. The average heart weight was 340 g in Group I and 431 g in Group II. Sclerosis of the coronary arteries, the circumference of the mitral valve ring, and thickness of the leaflets did not differ significantly. Estimated volume of the left atrium was significantly greater in Group II than in Group I (185 ml vs 57 ml, p less than 0.05). Jet lesions were observed in 10 of the 13 cases. The etiologies of RCT were previous endocarditis in two, mitral valve prolapse in three, and spontaneous rupture in eight. Congestive heart failure was observed in three (60%) in Group I and eight (100%) in Group II (p less than 0.01). Cardiothoracic ratio more than 60% was observed in three (60%) of Group I and six (75%) of Group II. Atrial fibrillation was demonstrated in one in Group I (20%) and six (75%) in Group II (p less than 0.05), and cardiac death in one (20%) in Group I and six (75%) in Group II (p less than 0.05). Phonocardiograms showed pansystolic murmur in all cases, third heart sound in nine (69%), and fourth heart sound in four (57%). Echocardiographically, RCT was diagnosed in six of nine cases (67%). In conclusion, patients with RCT involving more than two chordae tendineae can show more severe clinical course than cases with a single RCT.

Computer analysis of automated Edman degradation and amino acid analysis data

Computer programs are described that allow facile analysis of data from a protein sequencer and amino acid analyzer. The sequencer program provides automated sequence interpretation while requiring minimal user interaction. The program serves as a powerful aid in deciphering mixture sequences and allows routine monitoring of sequencer performance. The computer program for amino acid analysis data provides the following calculations: mole percent, protein concentration and residues per mole with comparison between theoretical and calculated values. A plot of molecular weight versus deviation from integer values is calculated providing a measure of peptide or protein purity.

[Tricuspid regurgitation induced by transvenous right ventricular pacing: echocardiographic and pathological observations]

To assess tricuspid regurgitation (TR) in patients with permanent transvenous right ventricular (RV) pacing, we performed phonocardiographic, contrast and pulsed Doppler echocardiographic studies in 18 patients with transvenous leads for RV pacing. In addition, a pathological study was performed on 26 autopsy cases with transvenous leads for RV pacing. None of the patients had right-sided heart failure. The previous phonocardiograms revealed regurgitant murmurs of TR in one clinical case and five autopsy cases. In the clinical study, definite TR was diagnosed both by contrast and pulsed Doppler echocardiography in five cases (28%). Probable TR was diagnosed only by one technique in three cases (17%), and the absence of TR was confirmed by both techniques in 10 cases (55%) (non-TR group). The average right atrial dimension was 59 +/- 5.3 mm in the definite TR group and 39 +/- 2.4 mm in the non-TR group (p less than 0.01). The average inferior vena cava dimension was 19 +/- 1.7 mm in the definite TR group and 15 +/- 0.8 mm in the non-TR group (p less than 0.05). Right atrial and inferior vena cava dimensions showed a significantly positive correlation (r = 0.58, p less than 0.05). In the pathological study, the presence of TR, which was explained by the position of the pacemaker lead in relation to the valve structure, was confirmed in 11 cases (42%). Valve motion interference was classified as type I (two cases), in which the lead was suppressed and the leaflet immobilized, type II (4 cases), in which chordae tendineae were involved by a pacemaker lead, and type III (five cases), in which both mechanisms contributed to valvular regurgitation. In conclusion, TR may follow transvenous RV pacing in approximately half of the cases with RV pacing. Contrast and pulsed Doppler echocardiography are sensitive noninvasive techniques for detecting this valvular abnormality and they should be used in the follow-up of such pacemaker recipients.

[Therapeutic goals for fluid management in profound shock]

The therapeutic goals for fluid replacement in 9 patients were studied. Five cases in sepsis, 2 in necrotizing pancreatitis and 2 in fat embolism were treated as dehydration or hypovolemia. Fluid replacement was performed with the view of obtaining the amelioration of circulation and urine output, even if CVP or PCWP had been elevated on admission. The values of CVP and PCWP, renal function and pulmonary function were assessed retrospectively. Out of 9 patients, one died of refractory shock, brain edema due to fat embolism and remaining one after recovery of shock. Out of 6 survivors, 2 showed oliguric renal failure, and 2 nonoliguric renal failure. The volume of administered fluid ranged from 5445 ml/10 hrs to 15820 ml/14 hrs and speeds of fluid administration were 545 ml/hr to 1248 ml/hr. CVP value on admission ranged from 4.0 to 22.0 cmH2O (3.0 to 16.3 mmHg), mean value 14.0 +/- 6.5 cmH2O. Through the course, the highest CVP and PCWP ranged from 12.5 to 26.5 (mean 19.8) mmHg and 14 to 36 (mean 20.9) mmHg, respectively. Out of 9 patients, 8 were suffering from respiratory distress, however, 7 recovered by PEEP except for one refractory shock. High values of CVP or PCWP could be recognized even if in hypovolemic shock and/or septic shock. Maintenance of higher values (18-20 mmHg) in CVP and/or PCWP during fluid resuscitation might be recommended because adequate fluid resuscitation could sustain the renal function, and result in good outcome.

Sodium selenite-induced hypothermia in mice: indirect evidence for a neural effect

The effect of sodium selenite (SS) on the body temperature of adult male ICR mice was examined. SS (10-60 mumol/kg) administered subcutaneously resulted in a transient and dose-dependent hypothermia at ambient temperatures (Ta) of 20 and 30 degrees C. Reduced oxygen consumption accompanied the changes in body temperature. In addition, SS-treated mice exhibited transient cold-seeking behavior in the thermogradient. This SS-induced hypothermia was very similar to those induced by ethanol, tetrahydrocannabinol, triethyltin, sulfolane, and chlordimeform in that these all were transient, dependent on Ta, and not counteracted by behavioral thermoregulation. From these results, involvement of neural afferent or integral pathways is suggested. Further, acute mortality of SS-injected mice was enhanced with the elevation of Ta, as in the case of the chemicals mentioned above. Considering the diverse chemical and pharmacological properties of these chemicals, these results may suggest a possible interrelation between the hypothermic response and the modification of toxicity.

Mercury-selenium interaction in workers exposed to elemental mercury vapor

Mercury (Hg) and selenium (Se) levels were determined for erythrocytes, plasma and urine of 25 male and 29 female workers exposed to elemental mercury (Hgo) vapor. Interrelationship between the Hg levels and the Se levels was examined by the correlational analysis and the stepwise regression analysis. Indicators of Se status (erythrocyte Se levels, plasma Se levels and urinary Se levels) were closely intercorrelated; similarly, indicators of exposure to Hgo vapor (erythrocyte inorganic Hg levels, plasma Hg levels and urinary Hg levels) were significantly intercorrelated. Since plasma Hg level was one of the significant independent variables in determining the erythrocyte Se and plasma Se levels, Hgo vapor exposure was thought likely to influence the Se metabolism in workers. None of the Se status indicators were significant as determinants of the indicators of Hgo vapor exposure.

[Mitral valvular disease secondary to mitral ring calcification: a clinicopathologic study]

Fifteen cases with mitral valvular disease caused by mitral ring calcification (MRC) were observed among 2,800 consecutive autopsy patients more than 60 years of age. They consisted of one man and 14 women whose average age was 86.4 years. All had been diagnosed as having mitral valvular disease during life. For this clinicopathologic study, the cases were categorized as nine cases with mitral regurgitation (MR Group) and six with mitral stenosis (MS Group). Among the 15 cases, phonocardiograms were obtained in 14 and echocardiograms in 6. In addition, 122 cases with MRC, the length of which was 5 mm or more, were selected from 900 recent consecutive autopsies of senile patients, to evaluate the site of calcification and to analyze the ratio of calcification length to mitral valve ring circumference. The following conclusions were obtained: The prevalence of mitral valvular disease due to MRC in the aged was 15/2,800 (0.5%). MR was observed in nine cases and MS in six. Phonocardiograms of the MR Group revealed a holosystolic murmur in seven cases, a late systolic murmur in one, a third heart sound in four and a fourth heart sound in five. In the MS Group, a holosystolic murmur was found in four, a presystolic murmur in four, a diastolic rumble in one, but no opening snap in any case. A diamond-shaped systolic murmur was found in nine cases with MS or MR, suggesting an ejection systolic murmur caused by an associated calcified aortic valve. Echocardiograms showed markedly decreased DDR in five cases and increased echo intensity of the aortic valve in four. Pathologic findings revealed that the mean length of MRC was 36.6 mm in the MR Group and 58.0 mm in the MS Group. The calcification ring ratio (CRR = MRC/MVR X 100) was 50.3% in the MR Group and 69.8% in the MS Group. In the MR Group, MRC involved the anterolateral commissure in three, posteromedial commissure in five, and both in one. In five of six cases with MS, both commissures were involved by MRC. The study of 122 cases with MRC length greater than or equal to 5 mm suggested that MRC occurred first in the middle scallop of the posterior mitral leaflet, and extended to the posterior scallop, subsequently extending up to the anterior scallop, and finally involved the anterior mitral leaflet beyond the commissures.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of fasting on hypoxia tolerance of mice in relation to oxygen consumption and heart rate

Mice more than 8 weeks old were fasted for 1 or 2 d and challenged by severe acute hypoxia. The hypoxia survival times (ST) were compared to the body weight, oxygen consumption (VO2), or heart rate (HR) of each animal. The duration of fasting was found to be important to determine ST. VO2 or HR were negatively correlated with ST, whether mice were fasted or not. The regression line (InST on HR) in the fed (control) group did not significantly differ from that of 2-d fasted groups, but those of fed and 1-d fasted groups differed. These results suggested that, in fasting for 2 d, the reduction in energy consumption was a major determining factor of hypoxia survival; in 1-d fasting, other factors might operate to determine the tolerance.

[Pathophysiology and prognosis of acute pancreatitis--early and late prognostic signs]

The purpose of this study is to elucidate the pathophysiology of the acute pancreatitis and set up the criteria for assessing the severity of this disease. One hundred and fifty seven cases of acute pancreatitis were treated at the First Surgical Department of Tokyo University Hospital and its affiliated hospitals. They consisted of 24 severe cases, 76 moderate cases, and 57 mild cases according to our classification. In early stage ten parameters, namely, abnormalities of white cell count, platelet count, hematocrit, lactic acid dehydrogenase, blood urea nitrogen, serum calcium, base excess, PaCO2 and fasting blood glucose and age within 24 hours after admission and X-ray CT scan within 48 hours as early prognostic signs, enabled us to predict severe, moderate, or mild pancreatitis. More than 4 weeks later than the onset of acute pancreatitis, X-ray CT scan, white blood cell count, elevation of serum FDP level, endotoxemia and fall of plasma opsonic index served as good indicators to evaluate the severity of abdominal sepsis. In experimental pancreatitis, CH50 and opsonic index were remarkably decreased at 6 and 12 hours after induction of acute pancreatitis. As the above results, determination of early prognostic signs immediately after onset and late prognostic signs 3-4 weeks after onset is very important to evaluate and manage the acute pancreatitis patients.

Kinetic studies on dextransucrase from the cariogenic oral bacterium Streptococcus mutans

The kinetic mechanism of dextransucrase was studied using the Streptococcus mutans enzyme purified by affinity chromatography to a specific activity of 36.9 mumol/min/mg of enzyme. In addition to dextran synthesis, the enzyme catalyzed sucrose hydrolysis and isotope exchange between fructose and sucrose. The rates of sucrose hydrolysis and dextran synthesis were partitioned as a function of dextran concentration such that exclusive sucrose hydrolysis was observed in the absence of dextran and exclusive dextran synthesis at high dextran concentrations. An analogous situation was observed with fructose-dependent partitioning of sucrose hydrolysis and fructose exchange. Steady state dextran synthesis and fructose isotope exchange kinetics were simplified by assay at dextran or fructose concentrations high enough to eliminate significant contributions from sucrose hydrolysis. This limited dextran synthesis assays to dextran concentrations above apparent saturation. The limitation was diminished by establishing conditions in which the enzyme does not distinguish between dextran as a substrate and product which allowed initial discrimination among mechanisms on the basis of the presence or absence of dextran substrate inhibition. No inhibition was observed, which excluded ping-pong and all but three common sequential mechanisms. Patterns of initial velocity fructose production inhibition and fructose isotope exchange at equilibrium were consistent with dextran synthesis proceeding by a rapid equilibrium random mechanism. A nonsequential segment was apparent in the exchange reaction between fructose and sucrose assayed in the absence of dextran. However, the absence of detectable glucosyl exchange between dextrans and the lack of steady state dextran substrate inhibition indicate that glucosyl transfer to dextran must occur almost exclusively through the sequential route. A review of the kinetic constants from steady state dextran synthesis, fructose product inhibition, and fructose isotope exchange showed a consistency in constants derived from each reaction and revealed that dextran binding increases the affinity of sucrose and fructose for dextransucrase.

Cell-matrix interrelation and cell-to-cell connection in the secretory ameloblast layer of kitten teeth

To investigate the cell-matrix interrelation and the structure and permeability of the junctional complexes of secretory ameloblasts, molar tooth germs from kittens were examined by means of scanning electron microscopy, routine thin sections and freeze-fracture replication. Scanning electron microscopy showed remarkably dissolved growth fronts of enamel in materials that had been fixed with glutaraldehyde and then subjected to EDTA perfusion for 10 min. By the action of EDTA, intercrystallite spaces in rod and interrod enamel were prominently widened, and their longitudinal ends of crystallites displayed irregular and extremely sparse structures. In enamel rods surrounded entirely by interrod enamel, and in enamel rods of the typical key hole shape with successive interrod enamel participation, the most striking dissolution of crystallites occurred at the boundaries between rod and interrod enamel, where broad expanses of rod-sheath spaces were observed. In thin sections, the Tomes processes of secretory ameloblasts occupying the above rods were rectangular or variations of a rectangular shape, respectively; and interameloblast spaces opened to the enamel growth fronts, which corresponded to the junction between rod and interrod enamel. In enamel rods standing in regular rows and showing the typical arcade shape, the centers of the rods were drastically dissolved and exhibited single and deep slits, whereas the boundaries between rod and interrod enamel showed no wide furrows. The Tomes processes occupying such arcade-shaped rods were typically triangular, and the interameloblast space always joined the type-1 face of process, which is responsible for enamel rod formation. Secretory ameloblast possessed two sets of junctional complexes at the proximal and distal ends of the cell body. The distal one was situated proximally to the Tomes process. Freeze-fracture replication demonstrated the functional structures of these junctions: the proximal junction was fascia occludens, and the distal one incomplete zonula occludens with many free-ending tight junctional strands and interstrand spaces or a less developed irregular junction.

[A clinical study on 164 patients with extensive burn--with special reference to improved survival factors]

One hundred and sixty four patients with extensive burn were treated over 6 years, 1976 through 1981. Clinical data were analyzed, dividing into successive period; Grod: Group I (83 patients, 1976-1978) and Group II (81 patients, 1979-1981). The mean age was 28.9 years, the mean burn area was 52.6% body surface area (% BSA) and Burn Index was 38.7 in group I, whereas in Group II 33.7 years, 56.0% BSA, 41.8, respectively. There are no statistical difference between the two groups. The mortality of the 164 patients was 50.6%. That of Group I was 55.4% and 45.7% in Group II. Excluding patients with almost fatal burns over 70% BSA or over 60 years of age, the former mortality is 33.3% and the latter is 21.3%. When a mortality rate was analyzed in patients with 50-70% BSA and aged less than 60 years in Group I, it was 65.0% and in Group II 36.8%. The main difference in the treatment between the two periods are as follows. Air fluidized beds were used in the latter period. As topical agents, silver sulfadiazine cream was administered in the former period, and silver sulfadiazine cream nitrate was administered in the latter period. Concerning debridement and skin graft, surgery was carried out 2-3 weeks after burn in the former period, while it started within one week in the latter period. In the latter period, active nutritional support and new generation of Cephem were used. These facts reveal that progress in various aspects of the treatments in the latter period have resulted in improvement of the mortality rate.