Depth release of illusory contour shape in the Ehrenstein grid

In the Ehrenstein grid, bright illusory patches delineated by illusory contours are seen. In order to assess whether the illusory patches possess shape constancy, the Ehrenstein grid was viewed straight on and at various angles of slant with respect to the observer. Observers matched the apparent shape of the illusory patches with a circle or an ellipse defined by real lines in a reference stimulus. Results show that, when viewed at a slanted angle, the shape of the bright patches was deformed and became oval. Such deformation was much less when the illusory contours were replaced by real contours. We label this dissociation of shape perception from depth cues depth release to contrast it with the previously described phenomenon of depth capture in which depth cues displace the illusory patches in depth. As a common explanation for both effects, it is proposed that the illusory contours induced by line ends or line ends themselves provide only weak or ineffective depth signals.

Alcohol dehydrogenase (ADH) isozymes in the AdhN/AdhN strain of Peromyscus maniculatus (ADH-deermouse) and a possible role of class III ADH in alcohol metabolism

Although the AdhN/AdhN strain of Peromyscus maniculatus (so-called ADH- deermouse) has been previously considered to be deficient in ADH, we found ADH isozymes of Classes II and III but not Class I in the liver of this strain. On the other hand, the AdhF/AdhF strain (so-called ADH+ deermouse), which has liver ADH activity, had Class I and III but not Class II ADH in the liver. In the stomach, Class III and IV ADHs were detected in both deermouse strains, as well as in the ddY mouse, which has the normal mammalian ADH system with four classes of ADH. These ADH isozymes were identified as electrophoretic phenotypes on the basis of their substrate specificity, pyrazole sensitivity, and immunoreactivity. Liver ADH activity of the ADH- strain was barely detectable in a conventional ADH assay using 15 mM ethanol as substrate; however, it increased markedly with high concentrations of ethanol (up to 3 M) or hexenol (7 mM). Furthermore, in a hydrophobic reaction medium containing 1.0 M t-butanol, liver ADH activity of this strain at low concentrations of ethanol (< 100 mM) greatly increased (about sevenfold), to more than 50% that of ADH+ deermouse. These results were attributable to the presence of Class III ADH and the absence of Class I ADH in the liver of ADH- deermouse. It was also found that even the ADH+ strain has low liver ADH activity (< 40% that of the ddY mouse) with 15 mM ethanol as substrate, probably due to low activity in Class I ADH. Consequently, liver ADH activity of this strain was lower than its stomach ADH activity, in contrast with the ddY mouse, whose ADH activity was much higher in the liver than in the stomach, as well as other mammals. Thus, the ADH systems in both ADH- and ADH+ deermouse were different not only from each other but also from that in the ddY mouse; the ADH- strain was deficient in only Class I ADH, and the ADH+ strain was deficient in Class II ADH and down-regulated in Class I ADH activity. Therefore, Class III ADH, which was found in both strains and activated allosterically, may participate in alcohol metabolism in deermouse, especially in the ADH- strain.

[Morphological study on the gastric mucosa in diabetes mellitus rats induced by streptozotocin]

To clarify the pathogenesis of vulnerability to acute gastric mucosal lesion (AGML) in diabetes mellitus (DM), we investigated histopathologically the gastric mucosa of the fundic gland in streptozotocin-induced DM rats. The length of the mucosa and the thickness of the surface epithelial cell (SEC) layer were measured, and the number of proliferating cell nuclear antigen (PCNA) positive cells was counted. As results, compared with control rats, the ratio of the length of SEC layer to that of mucosa, and the number of PCNA positive cells were significantly decreased in DM rats, whereas the length of the mucosa tended to extend in DM rats. Consequently, it is considered that attenuation of mucosal barrier in the SEC layer can be closely associated with susceptibility to occurrence of AGML in DM.

Extensive lichen amyloidosus refractory to DMSO

While lichen amyloidosus reportedly may respond to dimethyl sulfoxide (DMSO) application, we present a patient whose lesions were refractory to this agent. This Japanese woman had chronic extensive lichen amyloidosus, mainly on her trunk. Her 10-year history of using nylon towels was the suspected cause. The application of DMSO ointment had no clinical effect, and the amyloid deposits persisted in the histological specimens despite the treatment. The administration of a topical corticosteroid led to gradual clinical improvement.

[Valve repair or valvulectomy without replacement for infective endocarditis: a report of 11 cases]

Recently advances in early diagnosis of infective endocarditis (IE) by echocardiography provide for IE as a target disorder for valve repair. Valvulectomy without replacement might be still better operation of choice for some cases of intractable right-sided endocarditis. For our experience in 11 cases of valve repair or valvulectomy without replacement for IE, actuarial survival and reoperation-free rate at 6.8 years of mean follow-up after surgery was 81.8% and 90.9%. Persistent infection and intraoperative evaluation of the residual regurgitation was the point for postoperative management after these procedures. Although an elaborative valve repair should be applied for right-sided endocarditis, total pulmonary valvulectomy or regional tricuspid valvulectomy without prosthesis was available for destructive endocarditis.

Up-regulation of high-affinity dehydroepiandrosterone binding activity by dehydroepiandrosterone in activated human T lymphocytes

Although evidence indicates that dehydroepiandrosterone (DHEA) exerts direct physiological effects, its mechanism of action remains unknown. DHEA binding sites were examined using a whole-cell binding assay in a human T lymphoid cell line, PEER, revealing that a single class of high-affinity binding sites for DHEA (dissociation constant = 7.4 +/- 0.53 nmol/L, mean +/- SE, n = 4) was greatly increased when treated with DHEA, phorbol-12-myristate-13-acetate, and the Ca2+ ionophore A23187. Bound [3H]DHEA was displaced sensitively by DHEA and secondarily by dihydrotestosterone, but not effectively by other steroids, including DHEA sulfate. These results not only indicate the existence of a DHEA receptor, but also suggest that T cells become susceptible to regulation by DHEA during the process of signal-induced activation.

Suppressive effect of growth hormone on the expression of peroxisome proliferator-activated receptor in cultured rat hepatocytes

The effect of growth (GH) and thyroid hormones (triiodothyronine, T3) on the expression of peroxisome proliferator-activated receptor (PPAR alpha) was examined using Northern blotting in primary cultures of rat hepatocytes. Exposure of the hepatocytes to GH at the concentrations of 5-500 ng/ml for 1 day decreased the steady state level of PPAR mRNA by 20-30% compared with the control. The decrease in the mRNA level reached about 50% after a 5-day exposure to 50 or 500 ng/ml GH. However, the PPAR mRNA level was increased by 30-50% in hepatocytes exposed to T3 at 30 or 300 nM. These findings suggest the suppression of PPAR expression as a possible mechanism for the GH-mediated suppression of the induction of peroxisomal beta-oxidation caused by peroxisome proliferators (PPs), whereas T3 may act in the other way to exert its suppressive effect on the PP induction of peroxisomal enzymes.

Mutational analysis of the CDKN2 (MTS1/p16ink4A) gene in primary B-cell lymphomas

The CDKN2 gene located on chromosome 9p21 encodes the cyclin-dependent kinase-4 inhibitor p16. This gene is a putative tumor-suppressor gene because of its frequent alterations in many kinds of tumor cell lines. We analyzed the CDKN2 gene to evaluate its alterations in 52 primary specimens of non-Hodgkin's lymphoma (NHL) or chronic lymphocytic leukemia (CLL) of B-cell origin by Southern blot analysis, polymerase chain reaction-mediated single-strand conformation polymorphism (PCR-SSCP) analysis, and direct sequencing. By Southern blot analysis, we showed homozygous deletion of the CDKN2 gene in 3 of 42 patients with B-NHL (7.1%). After screening by PCR-SSCP analysis, direct sequencing identified one missense mutation at codon 72 (nucleotide 233) and two frameshifts due to a 35-bp deletion arising at codon 49 (nucleotides 163 to 175) in patients with B-NHL (3 of 42, 7.1%). In the patient carrying the missense mutation, hemizygous deletion of the CDKN2 gene was also suspected. In this study, we detected alterations in CDKN2 in 6 of 42 patients (14.3%) with B-NHL and in none of 10 patients with B-CLL. Our results suggest that the CDKN2 alterations contribute in tumorigenesis in some patients with B-NHL.

Induction of hepatic P-glycoprotein enhances biliary excretion of vincristine in rats

To clarify the contribution of P-glycoprotein to the biliary excretion of vincristine in rats, the effects of induction of hepatic P-glycoprotein by a phenothiazine treatment on the biliary excretion of [3H]vincristine were investigated. Immunoblot analysis using C219, a monoclonal antibody to P-glycoprotein, demonstrated that the phenothiazine treatment increased the P-glycoprotein level in isolated bile canalicular membrane vesicles approximately 6.5-fold. Transport of [3H]vincristine to canalicular membrane vesicles from the phenothiazine-treated and control rats revealed ATP-dependency, with an overshoot that results from the consumption of medium ATP. The maximum ATP-dependent uptake was increased in canalicular membrane vesicles from the phenothiazine-treated rats approximately 2-fold compared to the control. The biliary excretion of [3H]vincristine was further studied using an indicator dilution method in a single-pass perfused liver. The ratios of the cumulative amount of [3H]vincristine excreted into the bile ot the amount of [3H]vincristine taken up by the liver at 15, 30 and 90 min were significantly increased in the phenothiazine-treated rats by 60, 45 and 25%, respectively, compared to the control rats. Furthermore, the corrected mean residence time of [3H]vincristine in hepatocytes in the phenothiazine-treated rats was reduced to 21 min from that in the control rats (30 min), supporting the contention that the induction of hepatic P-glycoprotein on the bile canalicular membrane function sas a transporter not only in the isolated membrane but also in the more physiological perfused liver system. One must be cautious in the interpretation of the data, however, since phenothiazine can induce other proteins which might affect the behavior of [3H]vincristine.

[Ultrasonography of pediatric right lower abdominal pain: correlation with clinical and pathological results]

Right lower abdominal pain is a common problem in the pediatric population. Ultrasonography (US) is a well-accepted imaging modality in the clinical management of this problem. One hundred and six consecutive pediatric patients with right lower abdominal pain were prospectively evaluated. There were 54 boys and 52 girls, with ages ranging from 3 to 15 years (mean: 9.9 years). Final diagnoses were established based on pathological findings or clinical follow-up. US had sensitivity of 90%, specificity of 98%, and accuracy of 94% in the diagnosis of acute appendicitis. Among all true negative cases (n = 55), there was a variety of US findings other than appendiceal abnormality in 21 cases including intestinal and/or mesenteric (n = 19), gallbladder (n = 1), and ovarian (n = 1) abnormalities. All 21 cases were managed medically without complication. We conclude that US of pediatric right lower abdominal pain is a reliable imaging modality not only for the diagnosis of surgical cases but for eliminating the unexpected surgical intervention.

AIDS-associated mycoplasmas possess phospholipases C in the membrane

Phosphatidylinositol- and phosphatidylcholine-hydrolyzing activities existed in the cell lysates of AIDS-associated Mycoplasma species, including Mycoplasma fermentans IID 812, M. fermentans incognitus, and M. penetrans GTU-54-6A1. These activities were found to be attributable to phospholipases C, because the water-soluble product from phosphatidylcholine digested by the cell lysate of M. fermentans IID 812 was phosphorylcholine. M. fermentans IID 812 was examined for localization of these enzymes, and it was found that they were associated with the membrane.

Effect of nifedipine on cyclic GMP turnover in cultured coronary smooth muscle cells

We investigated the effects of nifedipine on cyclic GMP turnover and the pertinent enzyme activities in cultured coronary smooth muscle cells (SMC). Nifedipine at high concentrations slightly decreased basal soluble guanylate cyclase activity and inhibited the action of sodium nitroprusside (SNP) but had no effect on the particulate form of the enzyme. In contrast, nifedipine inhibited cyclic GMP hydrolysis by directly inhibiting the partially purified calmodulin-stimulated isoform of phosphodiesterase (type I PDE) with IC50 of 4.2 microM. Nifedipine > or = 1.0 microM enhanced cyclic GMP accumulation in response to 1.0 microM SNP, although nifedipine alone exerted no influence on cyclic GMP levels. Enhancement of cyclic GMP accumulation by nifedipine in response to SNP was not affected by BAY K 8644, a calcium channel agonist. These properties may be shared by other dihydropyridines since nicardipine and nisoldipine also inhibited type I PDE with similar IC50. However, some other structurally unrelated calcium channel blockers, diltiazem and verapamil, had little effect on cyclic nucleotide hydrolysis or on cyclic GMP accumulation in response to SNP. Nifedipine may synergistically enhance cyclic GMP accumulation in response to nitric oxide (NO)-releasing agents by directly inhibiting type I PDE in coronary SMC. Such effects of nifedipine may partly contribute to coronary vasodilation and prevention of coronary spasm in patients with ischemic heart disease.

Dietary intake of cadmium and lead among the general population in Korea

This survey was conducted in Seoul, Pusan, Chunan, and Haman in Korea to clarify cadmium and lead burden in the general Korean populations in terms of dietary intake of cadmium and lead and the concentrations of the two metals in blood. People who participated in the study were 141 healthy nonsmoking women aged 21-56 years. Determination of cadmium and lead in 24-hr food duplicates and blood samples was carried out by graphite furnace atomic absorption spectrophotometry. The geometric means for the four sites in combination were 21.2 micrograms/day for dietary cadmium, 20.5 micrograms/day for dietary lead, 1.27 ng/ml for blood cadmium, and 44.3 ng/ml for blood lead. Cadmium intake from boiled rice accounted for 23% of total daily cadmium intake. The counterpart value for lead intake from boiled rice was 12%. Blood cadmium levels and dietary cadmium intake were lower and blood lead level and dietary lead intake were higher in Korean women than in Japanese women. The values for dietary cadmium are similar to, and the values for dietary lead are somewhat lower than, the levels reported from Europe and the United States. Dietary intake was the main source of cadmium exposure, whereas lead exposure was from both ambient air and foods in the Korean population.

Propagation of local motion correspondence

We examined how the direction of apparent motion in one part of a scene can propagate and constrain motion direction in another part. The stimulus scene consisted of an array of dots all moving in the same physical direction at the same time. According to the proximity rule, the dots in the interior of the array should appear to move rightward and the dots at the edges should appear to oscillate horizontally. However, we found that: (1) with long frame durations, the interior dots also appeared to oscillate; (2) with shorter frame durations, the likelihood that the subjects perceived rightward motion at the center of the array increased; (3) oscillation was observed at the edges regardless of frame duration; (4) when opaque objects were placed on both the left and right sides of the array as occluders, only rightward motion was observed both in the center and at the edges of the occluders independent of frame duration; (5) in all cases, similar results were obtained with both foveal and peripheral viewing of either the center or the edge; and (6) with longer frame durations, the interior area within which oscillations were observed became larger. These findings suggest that signals for motion correspondence (oscillation) can gradually propagate to distant units (roughly 30 deg/sec). This can be explained by a locally-connected iterative network model.

Intraoperative evaluation of myocardial viability by nitroglycerin-induced improvement in regional left ventricular function assessed by transesophageal echocardiography

The aim of this study was to assess whether intraoperative transesophageal echocardiography with nitroglycerin infusion could identify viable myocardium. Twenty-eight patients with coronary artery disease with regional dysfunction underwent transesophageal echocardiography during bypass surgery. A transgastric left ventricular cross-sectional image at the midpapillary level was obtained and divided into four segments for wall motion analysis. Forty-four segments were graded as asynergic. Nitroglycerin was then given intravenously with an initial infusion rate of 1 microgram/kg/min, followed by an increase in dose up to 3 micrograms/kg/mini. Functional improvement with nitroglycerin was observed in 33 or 44 asynergic segments, while 11 remained unchanged. Follow-up transthoracic echocardiography was performed at 15.9 +/- 5.5 days after surgery. A segment was defined as viable when wall motion was better than or equal to severe hypokinesis at baseline or follow-up. Forty-three of 44 asynergic segments at baseline were defined as viable; these were the same segments demonstrating wall thickening with nitroglycerin. In particular, four of 5 akinetic segments at baseline demonstrated viability at follow-up, which had been predicted with nitroglycerin. Transesophageal echocardiography with nitroglycerin correctly identified viability (p < 0.05). No adverse hemodynamic effect was observed. Intraoperative transesophageal echocardiography with nitroglycerin appears to be a safe, noninvasive, feasible, and widely available method to identify myocardial viability under the condition supported by cardiopulmonary bypass.

Histamine H1 receptor occupancy in human brains after single oral doses of histamine H1 antagonists measured by positron emission tomography

1. Histamine H1 receptor occupancy in the human brain was measured in 20 healthy young men by positron emission tomography (PET) using [11C]-doxepin. 2. (+)-Chlorpheniramine, a selective and classical antihistamine, occupied 76.8 +/- 4.2% of the averaged values of available histamine H1 receptors in the frontal cortex after its administration in a single oral dose of 2 mg. Intravenous administration of 5 mg (+)-chlorpheniramine almost completely abolished the binding of [11C]-doxepin to H1 receptors (H1 receptor occupancy: 98.2 +/- 1.2%). 3. Terfenadine, a nonsedative antihistamine, occupied 17.2 +/- 14.2% of the available H1 receptors in the human frontal cortex after its administration in a single oral dose of 60 mg. 4. There was no correlation between H1 receptor occupancy by terfenadine and the plasma concentration of the active acid metabolite of terfenadine in each subject. 5. PET data on human brain were essentially compatible with those on H1 receptor occupancy in guinea-pig brain determined by in vivo binding techniques, although for the same H1 receptor occupancy the dose was less in human subjects than in guinea-pigs. 6. The PET studies demonstrated the usefulness of measuring H1 receptor occupancy with classical and second-generation antihistamines in human brain to estimate their unwanted side effects such as sedation and drowsiness quantitatively.

Imidapril hydrochloride in essential hypertension: a double-blind comparative study using enalapril maleate as a control

OBJECTIVE

To assess the value of using imidapril hydrochloride (ACE/TA-6366), a long-acting angiotensin converting enzyme (ACE) inhibitor developed in Japan, to treat patients with essential hypertension.

PATIENTS AND METHODS

A double-blind, comparative, phase III study was carried out using enalapril maleate as a control, with a 4-week observation period and a 12-week treatment period. Both drugs were started at a dose of 5 mg once a day, increasing to 10 mg in patients whose antihypertensive response was insufficient after 4 weeks. The study included 231 outpatients aged 30-74 years; of these, 108 in the imidapril group and 115 in the enalapril group were assessed. There were no differences in background factors between groups.

RESULTS

An adequate antihypertensive effect was observed in 71.3% (77/108) in the imidapril group in in 66.1% (76/115) in the enalapril group, with no significant difference between groups. The pulse rate was unchanged in both groups. The drug had no adverse effects in 86.1% (93/108) of the imidapril group and 79.1% (91/115) of the enalapril group, with no significant difference between groups. Adverse drug effects were observed din 5.6% (6/108) of the imidapril group and 12.2% (14/115) of the enalapril group. Cough was the most frequent side effect, reported in 0.9% (1/108) of the imidapril group and 7.0% (8/115) of the enalapril group. Other side effects were reported in 4.6% (5/108) of the imidapril group and 5.2% (6/115) of the enalapril group. Abnormal laboratory values were observed in 3.7% (4/108) of the imidapril group and 0.9% (1/115) of the enalapril group.

CONCLUSIONS

Imidapril showed excellent clinical efficacy and safety compared to enalapril. The low incidence of cough is of particular interest.

Juvenile parkinsonism treated with bilateral pallidotomies--case report

A 47-year-old female diagnosed as having juvenile parkinsonism at age 38 years developed progressive motor fluctuation while receiving levodopa medication. She underwent right posteroventral pallidotomy which achieved only a transient effect on the wearing-off. An additional procedure on the left pallidum resulted in long-lasting relief of the parkinsonian symptoms.

[Effect of repeated toothbrushing instructions on periodontal health in a community]

This study was conducted to compare the effect of frequency of toothbrushing instruction using the Toothpick Method in a community periodontal health program. Two courses, one consisting of three monthly toothbrushing instructions and the other a single instruction session, were given to residents in a small town. Thirty-one subjects (mean age; 48.7 +/- 9.2) in the three-time instruction course and 40 subjects (mean age; 55.2 +/- 8.3) in the single instruction course participated in dental examinations. During the first visit, the subjects of the both groups attended a class for dental health education, and observed their dental plaque using a phase contrast microscope, and the condition of their teeth and periodontal tissue was recorded. They were instructed to brush their teeth by the Toothpick Method. After 1 year, the subjects of the both groups were examined and required to fill out a questionnaire. The percentage of sites with gingival redness and swelling significantly decreased after 1 month, 2 months and 1 year in the three-time instruction group. In the single instruction group, however, gingival redness and swelling did not change after 1 year. The percentage of sites with bleeding on probing significantly decreased in the both groups. The improvement ratio for the CPITN code was higher in the three-time instruction group than the other. The questionnaire showed that subjects in the three-time instruction group brushed their teeth more actively, and were more satisfied with the program than those in the single instruction group. These results show that the three-time instruction course was more effective than the single instruction course.(ABSTRACT TRUNCATED AT 250 WORDS)

Genetic influences on bone density: physiological correlates of vitamin D receptor gene alleles in premenopausal women

Common vitamin D receptor (VDR) gene alleles have recently been shown to contribute to the genetic variability in bone mass and bone turnover, however, the physiological mechanisms involved are unknown. To examine this, the response to 7 days of 2 micrograms oral 1,25-dihydroxyvitamin D[1,25-(OH)2D] (calcitriol) stimulation was assessed in 21 premenopausal women, homozygous for one or other of the common VDR alleles (bb, n = 11; BB, n = 10). Indices of bone turnover and calcium homeostasis were measured during 2 weeks. Baseline osteocalcin, 1,25-(OH)2D, type I collagen carboxyterminal telopeptide, and inorganic phosphate levels were significantly higher and spinal bone mineral density was significantly lower in the BB allelic group. After calcitriol administration, similar levels of 1,25-(OH)2D were attained throughout the study in both genotypic groups. The increase in serum osteocalcin levels in the BB group was significantly less than that in the bb group (11% vs. 32%, P = 0.01). The genotype-related baseline difference in osteocalcin levels was not apparent at the similar serum 1,25-(OH)2D levels. By contrast, the baseline differences in phosphate and type I collagen carboxyterminal telopeptide persisted throughout the study. Serum ionized calcium levels did not differ between genotypes, nor did it move out of normal range values. However, parathyroid hormone was less suppressed in the low bone density group (38% vs. 11%, P = 0.01). These data indicate that the VDR alleles are associated with differences in the vitamin D endocrine system and may have important implications in relation to the pathophysiology of osteoporosis.

Biotin influences palatal development of mouse embryos in organ culture

Maternal biotin deficiency is strongly teratogenic in CD-1 mice. The most common malformations are craniofacial and limb defects such as cleft palate, micrognathia and micromelia. The effect of biotin deficiency on palatal development in mouse embryos on d 12 of gestation was studied by culturing mouse embryonic palates in serum-free medium using a suspension culture system. In control embryos palatal processes developed to the fused stage after 72 h in culture. The fusion of palatal processes was further increased by the addition of biotin (10(-8) mol/L) to the medium. The addition of organic acids such as propionic, beta-methyl crotonic or beta-hydroxy isovaleric acids as well as avidin to the medium did not affect the stage of palatal formation. Cycloheximide completely blocked the fusion of palatal shelves. In embryos from biotin-deficient mice, the incidence of fusion between the palatal shelves was < 7% and increased to > 30% when biotin (10(-8)-10(-6) mol/L) was added to the medium. The addition of fatty acids to the organ culture medium did not have any effect on the fusion of palatal processes. The incorporation of 35S-methionine into protein from biotin-deficient embryo explants was 88% of that in controls. The results indicate that biotin deficiency may interfere directly with synthesis of specific proteins and the formation of palatal processes.

Functional role of coronary collaterals with exercise in infarct-related myocardium

We evaluated the regional myocardial blood flow in collateral dependent infarct-related areas to examine the functional role of coronary collaterals. Regional myocardial blood flow was measured by positron emission tomography with 13N-ammonia at rest and during low-grade exercise (bicycle ergometer fixed at 25 W for 6.5 min). The study was performed in 24 subjects, consisting of 19 patients with prior myocardial infarction, and five normal individuals. Regional myocardial blood flow was calculated using the radioactivity in myocardial tissue measured by positron emission tomography and the radioactivity in arterial blood. Concerning the infarct related area, the exercise caused myocardial blood flow to decrease by 18.4% (P < 0.01) in the collateral-dependent areas (n = 8) of angiographically positive collaterals, and to increase by 14.4% (P = not significant) in the areas (n = 10) of negative collaterals. Four patients in whom the myocardial blood flow in all walls, including the normal areas, decreased with exercise were excluded from this evaluation. Myocardial blood flow in collateral-dependent infarct-related areas appeared to decrease transiently by low-grade exercise. Our results suggest that collaterals increase the incidence of exercise-induced ischemia, but may protect the infarct related but viable myocardium from necrosis.

Immunocytochemical colocalizations of serotonin, aromatic L-amino acid decarboxylase and polypeptide hormones in A- and PP-cells of the chicken endocrine pancreas

The colocalization of serotonin and aromatic L-amino acid decarboxylase (AADC) in the avian pancreatic polypeptide-containing PP-cells and glucagon-storing A-cells of the chicken endocrine pancreas was investigated using combined pre-embedding immuno-peroxidase and post-embedding immunogold electron microscopic immunocytochemistry. The avian pancreatic polypeptide-immunoreactive cells manifested by the labeling of immunogold particles on secretory granules were also immunoreactive with antisera directed against serotonin and AADC, an enzyme involved in the synthesis of serotonin. In PP-cells immunoreactivity against the anti-serotonin serum was stronger in secretory granules than in the cytoplasmic matrix, whereas immunoreaction with the anti-AADC serum was observed to be more intense in the cytoplasmic matrix. Immunoreactions with the serotonin and AADC antisera were also found in secretory granules of glucagon-storing A-cells. These results indicate that serotonin is co-stored within secretory granules of both A- and PP-cells, and that AADC is localized within secretory granules of A-cells, and may be present in the cytoplasmic matrix of PP-cells. It is probable that serotonin is synthesized and released simultaneously with secretory granules from both A- and PP-cells of the chicken endocrine pancreas.