Purine receptors modulate chondrocyte extracellular inorganic pyrophosphate production.

OBJECTIVE: Extracellular inorganic pyrophosphate (ePPi) plays a key role in the regulation of normal and pathologic mineralization. The purpose of this work was to evaluate the role of P1 and P2 purine receptors in modulating ePPi production by articular chondrocytes. METHODS: Porcine cartilage explants and chondrocyte monolayers were cultured in the presence of P1 agonists, or a P2 agonist or antagonist and inhibitors of P2 signaling. Ambient media ePPi concentrations were measured after 48-96h. RESULTS: The P1 agonists NECA and CGS 21680 significantly decreased ePPi concentrations surrounding chondrocytes and cartilage explants. The P2 agonist, ADP, increased ePPi levels, and the P2 antagonist, suramin, decreased ePPi concentrations. Thapsigargin and 1,2 bis-(2-aminophenoxy)ethane-N,N,N'N'-tetra acetic acid (BAPTA), which dampen Ca(2+)-related P2 signaling, suppressed the response to ADP. CONCLUSIONS: Purine receptors are important regulators of ePPi production by chondrocytes. P1 receptor stimulation diminishes and P2 receptor stimulation enhances ePPi production. Alterations in receptor signaling or aberrations of extracellular purine nucleotide metabolism resulting in abnormal quantities or proportions of P1 and P2 receptor ligands could foster changes in ePPi production that in turn affect mineralization. We propose a homeostatic role for extracellular purine nucleotides and purine receptors in stabilizing ePPi concentrations.

A unique ectonucleotide pyrophosphohydrolase associated with porcine chondrocyte-derived vesicles.

Previous studies have shown increased nucleotide pyrophosphohydrolase (EC 3.6.1.8) (NTPPHase) activity in detergent extracts of degenerated human cartilage containing calcium pyrophosphate dihydrate (CPPD) crystals relative to those from osteoarthritis or normal cartilage. NTPPHase was later shown to be an ectoenzyme and its activity was increased in synovial fluid from patients with CPPD crystal deposits relative to fluids from other types of arthritis. We have purified a soluble 61-kD NTPPHase from conditioned media of organ-cultured porcine articular cartilage to electrophoretic homogeneity. Its NH2-terminal sequence through 26 cycles showed < 30% homology to any previously reported protein sequence. An antibody raised to a synthetic peptide corresponding to this sequence reacted with denatured but not native enzyme. This antibody reacted against a sedimentable vesicle-associated 127-kD protein in conditioned media from cultured articular cartilage or from chondrocytes in primary monolayer culture and against a series of soluble proteins in conditioned media supernatant, including a 61-kD protein representing our original isolate. No reactivity was found in 1% SDS extracts of washed cultured chondrocytes, although these contained greater NTPPHase activity than the conditioned media. Antibody to PC-1, another ectoNTPPHase, reacted with 1% SDS extracts of whole chondrocytes but not against those chromatographic fractions containing the major portion of NTPPHase activity. Release of the vesicle-associated 127-kD enzyme into conditioned medium was stimulated three- to sevenfold by TGF beta 1. The antibody also reacted with a series of soluble proteins and with 127-kD sedimentable protein in human synovial fluid. Kinetic studies supported the existence of a unique vesicle-associated NTPPHase; apparent Km (mM) of chondrocyte membrane NTPPHase was 1.5 and 3.0 at pH 7.3 and 9.88, respectively; apparent Km (mM) of vesicle associated NTPPHase was 0.83 and 1.28 at pH 7.3 and 9.88. The data suggest the existence of a unique ecto-NTPPHase associated with vesicles derived from normal articular cartilage.

Induction of JAB/SOCS-1/SSI-1 and CIS3/SOCS-3/SSI-3 is involved in gp130 resistance in cardiovascular system in rat treated with cardiotrophin-1 in vivo.

CIS (cytokine-inducible SH2 protein), SOCS (suppressor of cytokine signaling), or SSI (signal transducers and activators of transcription [STAT]-induced STAT inhibitor) proteins are a family of cytokine-inducible negative regulators of cytokine signaling via Janus kinase (JAK)-STAT pathways. Given the evidence that the JAK-STAT pathway plays a critical role in the cardiovascular system, the primary objective of this study was to assess the effects of the CIS family on JAK-STAT signaling in the cardiovascular system in rats treated with cardiotrophin-1 (CT-1), an interleukin-6 family of cytokines. Intravenous injection of 20 microgram/kg body weight of CT-1 induced a transient, marked increase in STAT3 activation in various tissues, including heart and lung, and subsequent upregulation of 2 members of the CIS family, JAK-binding protein (JAB)/SOCS-1/SSI-1 and CIS3/SOCS-3/SSI-3, in the same tissues. It was also observed that CIS3 was directly associated with JAK2 in vivo. Pretreatment with the same dose of CT-1 60 minutes before significantly attenuated the STAT3 activation induced by a second injection of CT-1. We previously reported that intravenous injection of CT-1 results in the nitric oxide (NO)-dependent hypotension accompanied by the induction of inducible NO synthase mRNA. In rats pretreated with CT-1, the induction of inducible NO synthase mRNA or hypotension by subsequent CT-1 injection was not observed. Forced expression of JAB or CIS3, but not other CISs, directly blocked CT-1-induced STAT3 activation in 293 cells. These results suggest that JAB and CIS3 serve as endogenous inhibitors of CT-1-mediated JAK-STAT signaling in the cardiovascular system in vivo.

Involvement of cardiotrophin-1 in cardiac myocyte-nonmyocyte interactions during hypertrophy of rat cardiac myocytes in vitro.

BACKGROUND: The mechanism responsible for cardiac hypertrophy is currently conceptualized as having 2 components, mediated by cardiac myocytes and nonmyocytes, respectively. The interaction between myocytes and nonmyocytes via growth factors and/or cytokines plays an important role in the development of cardiac hypertrophy. We found that cardiac myocytes showed hypertrophic changes when cocultured with cardiac nonmyocytes. Cardiotrophin-1 (CT-1), a new member of the interleukin-6 family of cytokines, was identified by its ability to induce hypertrophic response in cardiac myocytes. In this study, we used the in vitro coculture system to examine how CT-1 is involved in the interaction between cardiac myocytes and nonmyocytes during the hypertrophy process. METHODS AND RESULTS: RNase protection assay revealed that CT-1 mRNA levels were 3. 5 times higher in cultured cardiac nonmyocytes than in cultured cardiac myocytes. We developed anti-CT-1 antibodies and found that they significantly inhibited the increased atrial and brain natriuretic peptide secretion and protein synthesis characteristic of hypertrophic changes of myocytes in the coculture. In addition, non-myocyte-conditioned medium rapidly elicited tyrosine phosphorylation of STAT3 and induced an increase in natriuretic peptide secretion and protein synthesis in cultured cardiac myocytes; these effects were partially suppressed by anti-CT-1 antibodies. Finally, the hypertrophic effects of CT-1 and endothelin-1, which we had previously implicated in the hypertrophic activity in the coculture, were additive in cardiac myocytes. CONCLUSIONS: These results show that CT-1 secreted from cardiac nonmyocytes is significantly involved in the hypertrophic changes of cardiac myocytes in the coculture and suggest that CT-1 is an important local regulator in the process of cardiac hypertrophy.

Variations in site and levels of expression of chondrocyte nucleotide pyrophosphohydrolase with aging.

The aim of this study was to identify changes in cartilage intermediate layer protein/nucleotide pyrophosphohydrolase (CILP/NTPPH) expression in articular cartilage during aging. Adult (3-4 years old) and young (7-10 days old) porcine articular hyaline cartilage and fibrocartilage were studied by Northern blot analysis, in situ hybridization, and immunohistochemistry using a complementary DNA (cDNA) probe encoding porcine CILP/NTPPH and antibody to a synthetic peptide corresponding to a CILP/NTPPH sequence. Northern blot analysis of chondrocytes showed lower expression of CILP/NTPPH messenger RNA (mRNA) in young cartilage than in adult cartilage. In adult cartilage, extracellular matrix from the surface to the middeep zone was immunoreactive for CILP/NTPPH, especially in the pericellular matrix surrounding the middeep zone chondrocytes. In young cartilage, chondrocytes were moderately immunoreactive for CILP/NTPPH throughout all zones except the calcified zone. The matrix of young cartilage was negative except in the superficial zone. In young cartilage, CILP/NTPPH mRNA expression was undetectable. In adult cartilage, chondrocytes showed strong mRNA expression for CILP/NTPPH throughout middeep zones. Protein and mRNA signals were not detectable below the tidemark. CILP/NTPPH secretion into matrix around chondrocytes increases with aging. In this extracellular site it may generate inorganic pyrophosphate and contribute to age-related calcium pyrophosphate dihydrate crystal deposition disease.

Endothelial nitric oxide synthase gene is positively associated with essential hypertension.

Essential hypertension has a genetic basis. Accumulating evidence, including findings of elevation of arterial blood pressure in mice lacking the endothelial nitric oxide synthase (eNOS) gene, strongly suggests that alteration in NO metabolism is implicated in hypertension. There are, however, no reports indicating that polymorphism in the eNOS gene is associated with essential hypertension. We have identified a missense variant, Glu298Asp, in exon 7 of the eNOS gene and demonstrated that it is associated with both coronary spastic angina and myocardial infarction. To explore the genetic involvement of the eNOS gene in essential hypertension, we examined the possible association between essential hypertension and several polymorphisms including the Glu298Asp variant, variable number tandem repeats in intron 4 (eNOS4b/4a), and two polymorphisms in introns 18 and 23. We performed a large-scale study of genetic association using two independent populations from Kyoto (n=458; 240 normotensive versus 218 hypertensive subjects) and Kumamoto (n=421; 223 normotensive versus 187 hypertensive subjects), Japan. In both groups, a new coding variant, Glu298Asp, showed a strong association with essential hypertension (Kyoto: odds ratio, 2.3 [95% confidence interval, 1.4 to 3.9]; Kumamoto: odds ratio, 2.4 [95% confidence interval, 1.4 to 4.0]). The allele frequencies of 298Asp in hypertensive subjects were significantly higher than those in normotensive subjects in both groups (Kyoto: 0.103 versus 0.050, P<0.0017; Kumamoto: 0.120 versus 0.058, P<0.0013, respectively). No such disequilibrium between genotypes was significantly associated with any other polymorphisms we examined; the Glu298Asp variant was also not linked to any other polymorphisms. In conclusion, the Glu298Asp missense variant was significantly associated with essential hypertension, which suggests that it is a genetic susceptibility factor for essential hypertension.

Molecular cloning and expression of a porcine chondrocyte nucleotide pyrophosphohydrolase.

The porcine 127-kDa nucleotide pyrophosphohydrolase (NTPPHase) had been previously purified from the conditioned culture media of porcine articular cartilage. Protein sequencing of an internal 61-kDa proteolytic fragment of NTPPHase (61-kDa NTPPHase) determined the 26 N-terminal amino acids. This sequence was used to amplify a DNA fragment, which was used as a probe to clone the gene encoding the 61-kDa NTPPHase from a porcine chondrocyte cDNA library. DNA sequence analysis showed the cDNA insert to be 2509 bp, corresponding to a predicted open reading frame (ORF) encoding 599 amino acids. The 26 N-terminal amino acids of the 61-kDa NTPPHase were located within the ORF immediately downstream of a putative protease recognition region, RRKRR. This is consistent with this cDNA insert representing an internal proteolytic fragment of the full length 127-kDa NTPPHase. BLAST and FASTA analysis confirmed that the deduced amino acid sequence of 61-kDa NTPPHase was unique and did not possess a high degree of homology to sequence in the non-redundant protein and nucleotide databases. Proteins that possess limited homology (< 17%) with the 61-kDa NTTPPHase include several prokaryotic and eukaryotic ATP pyrophosphate-lyases (adenylate cyclase). Northern blot analysis of porcine chondrocyte RNA showed that the DNA encoding the 61-kDa NTPPHase hybridized to a single 4.0-kb RNA transcript. This DNA probe also hybridized to a single species of human chondrocyte RNA. Expression of a 61-kDa protein was detected by coupled in-vitro transcription/translation. Western blot analysis of this in-vitro transcription/translation reaction detected a 61-kDa protein, using an antibody raised against the peptide sequence that was originally used to clone the 61-kDa NTPPHase. These data indicate the successful in-vitro cloning and expression of the porcine chondrocyte 61-kDa NTPPHase. Future studies that utilize the gene encoding the 61-kDa NTPPHase may allow the characterization of the role of NTPPHase in calcium pyrophosphate dihydrate (CPPD) crystal deposition disease.

A heart-specific increase in cardiotrophin-1 gene expression precedes the establishment of ventricular hypertrophy in genetically hypertensive rats.

OBJECTIVE: Cardiotrophin-1 is a cytokine, a novel member of the interleukin-6 superfamily, which is isolated from mouse embryoid bodies. It is known to bind a gp130/ leukemia inhibitory factor (LIF) receptor heterodimer and to induce myocyte hypertrophy. Accumulating evidence indicates that a gp130 signaling pathway is involved in cardiac development and ventricular hypertrophy. METHODS: In order to elucidate the pathophysiologic significance of cardiotrophin-1 in ventricular hypertrophy associated with hypertension, we examined the level of cardiotrophin-1 mRNA in the ventricle of spontaneously hypertensive rats/Izm stroke-prone (SHRSP/Izm) in neonates, and at 4-, 12- and 20-weeks of age by Northern blot analysis. We also examined the gene expression of LIF by Northern blot and reverse transcription-polymerase chain reaction analyses. RESULTS: No significant difference was observed in the level of cardiotrophin-1 mRNA in the ventricle between SHRSP/ Izm and Wistar-Kyoto/Izm (WKY/Izm) neonates. However, the level of cardiotrophin-1 mRNA in the ventricle was significantly augmented in 4-week-old SHRSP/Izm, which did not yet show overt ventricular hypertrophy, and its augmented expression lasted for the duration of the experimental period. The difference in the level of cardiotrophin-1 mRNA between the two strains was most prominent at the age of 4 weeks. This augmented expression of the cardiotrophin-1 gene was not related to the severity of left ventricular hypertrophy. The level of cardiotrophin-1 mRNA in other organs, including the kidney and lung, showed no significant change with aging and was not different between the two strains. After long-term treatment with lisinopril, levels of cardiotrophin-1 mRNA were not changed, although it morphologically prevented the development of left ventricular hypertrophy. LIF mRNA was not detected in any ventricles examined by Northern blot analysis. CONCLUSIONS: The present study demonstrates that the expression of cardiotrophin-1 mRNA is increased in the early stage of ventricular hypertrophy in SHRSP/Izm and it remains elevated after hypertrophy has been established. However, it is unlikely that cardiotrophin-1 plays a mechanistic role in the development and maintenance of left ventricular hypertrophy in SHRSP/Izm. The present study also suggests that cardiotrophin-1, but not LIF, is a possible candidate for natural ligand of a gp130 signaling pathway in the heart.

Regional abnormality of iodine-123-MIBG in diabetic hearts.

UNLABELLED: Autonomic neuropathy along with cardiac denervation is one of the prognostic factors of diabetic patients. The aim of this study was to establish qualitative and quantitative assessment of diabetic cardiac denervation using [123I]metaiodobenzylguanidine (MIBG). METHODS: The study population consisted of 31 diabetic patients and 12 control subjects (C). Diabetic patients were classified into the following three groups according to their presentation of neuropathy: NO, without neuropathy; N1, mild neuropathy; N2, severe neuropathy. All subjects underwent triple-phase MIBG scanning, including dynamic planar imaging as well as early and delayed planar and SPECT imaging. Myocardial uptake ratios of MIBG and heart-to-mediastinum count ratios (H/M) were calculated as global uptake indices. Inferior-to-anterior count ratios and coefficients of variation were calculated as regional distribution indices. The washout rate of the inferior wall and whole myocardium were also studied. RESULTS: MIBG abnormalities were obvious in the inferior wall, which gradually spread to the adjacent segments. All indices of regional uptake showed a significant difference (p < 0.01) among the groups, while only the H/M of the late image showed significant differences in the two global uptake indices (p = 0.02). the washout rate of the inferior wall was enhanced with neuropathy. CONCLUSION: Diabetic neuropathy involves an MIBG abnormality in its early stages. Since this abnormality occurs in the inferior segment, an inferior-to-anterior count ratio, an index of regional MIBG uptake could be suitable for the evaluation of this condition because of its superior sensitivity.

First-pass radionuclide angiography using iodine-123 myocardial tracers and a multicrystal gamma camera.

UNLABELLED: The purpose of this study was to validate the accuracy of the assessment of ventricular function by first-pass radionuclide angiography (FPRNA) with 123I myocardial tracers and a multicrystal gamma camera. METHODS: Left ventricular ejection fraction (LVEF) and right ventricular ejection fraction were measured in 69 patients by FPRNA using 123I myocardial tracers (126 +/- 7 MBq) and 99mTc tracers (541 +/- 141 MBq) on a multicrystal gamma camera with a high-sensitivity collimator. For 44 patients, ejection fraction values measured by 123I-FPRNA were compared to those estimated by equilibrium radionuclide angiography (ERNA). Visual wall-motion analysis was also performed to judge clinical acceptability of 123I-FPRNA images for identification of wall-motion abnormality. RESULTS: Mean LVEFs (%) estimated by 123I-FPRNA and by 99mTc-FPRNA were 49.6 +/- 13.6 and 49.1 +/- 14.1, respectively (nonsignificant p value). An excellent correlation was found between LVEFs estimated by 123I-FPRNA and 99mTc-FPRNA (r = 0.96, s.e.e. = 1.9%). Values of LVEF measured by 123I-FPRNA also demonstrated excellent correlation with those measured by ERNA (r = 0.95, s.e.e. = 2.2%). A good correlation was also noted between right ventricular ejection fractions measured by 123I-FPRNA and 99mTc-FPRNA (r = 0.72, s.e.e. = 4.0%). The Spearman rank correlation coefficient between 123I-FPRNA and ERNA wall-motion scores was 0.87 (n = 135, p < 0.001). CONCLUSION: Resting ventricular function can be reliably measured with 123I-FPRNA in combination with a multicrystal gamma camera. This indicates that the assessment of ventricular function is feasible in conjunction with 123I myocardial imaging without an increase in cost or radiation dose to patients.

Abnormality of myocardial oxidative metabolism in noninsulin-dependent diabetes mellitus.

UNLABELLED: The purpose of this study was to evaluate oxidative metabolism and its response by dobutamine in patients with noninsulin-dependent diabetes mellitus (NIDDM) using 11C-acetate PET. METHODS: We studied 16 patients with NIDDM (9 men, 7 women; mean age 53.7 +/- 12.8 yr) and 6 healthy male control subjects (mean age 41.8 +/- 17.2 yr). None of them had an abnormality on stress-perfusion SPECT. The 11C-acetate clearances (Kmono) were compared regionally for five myocardial segments in all subjects at rest and during low-dose dobutamine stress in 13 patients (8 patients with NIDDM, age 51.9 +/- 13.6 yr; 5 healthy male control subjects, age 45.6 +/- 16.3 yr). Correlation between regional Kmono and rate-pressure product (RPP) was also studied. RESULTS: At rest, the clearance of 11C-acetate was slightly heterogeneous for both patients with NIDDM and healthy control subjects, with smaller values in the apex and inferior wall in both groups. The difference became significant during dobutamine stress in the patients. The RPP-to-Kmono (average for five segments) ratio at rest was slightly smaller in the patients (1042.7 +/- 559.1 x 0.01) than in the healthy control subjects (1391.4 +/- 209.6 x 0.01, not significant), and those during dobutamine stress were almost the same in the two groups (1457.3 +/- 737.4 x 0.01 and 1486.0 +/- 211.8 x 0.01, respectively). A significant correlation was seen between regional Kmono and RPP in every segment in the healthy control subjects (average; r = 0.89; p < 0.01), whereas more scattered correlation with greater regional variation was observed in the patients (average; r = 0.31; p value was not significant). CONCLUSION: Patients with NIDDM showed slight regional heterogeneity in myocardial oxidative metabolism. They also had more scattered correlation between myocardial oxidative metabolism and cardiac work (RPP) than healthy control subjects, with the smallest correlation coefficient observed in the inferior wall. These findings may help the understanding of dynamics in myocardial oxidative metabolism of NIDDM hearts.

Gene transfer with liposomes to the intraocular tissues by different routes of administration.

PURPOSE: To determine whether a reporter gene carried by liposomes can be introduced into the ocular tissues in vivo by different routes of administration. METHODS: Three different kinds of liposomes carrying plasmid DNA with beta-galactosidase gene were applied topically to the eye or were injected into the anterior chamber, subretinal space, and vitreous of adult Wistar rats. Gene expression was detected by enzymatic color reaction using X-gal as a substrate in enucleated eyes 1 day, 1 week, and 1 month after topical application or injection. RESULTS: Topical application could transfer the gene to retinal ganglion cells. Injection into the anterior chamber delivered the gene to the basal layer of the corneal epithelium, ciliary epithelium, stroma of the ciliary body and iris, and retinal ganglion cells. Injection into the vitreous or subretinal space resulted in the expression of the gene in the ciliary epithelium, stroma of the ciliary body and iris, retinal ganglion cells, and retinal pigment epithelial cells. CONCLUSIONS: Efficient and stable transfer of the functional gene could be achieved by liposomes in the cornea, iris, ciliary body, and retina of rats. Liposomes appear to be a promising vehicle for delivering therapeutic genes in vivo to mammalian intraocular tissues.

Clinical implications of leptin and its potential humoral regulators in long-term low-calorie diet therapy for obese humans.

OBJECTIVE: To address the clinical implications of leptin and to re-examine the relationship between leptin and its potential humoral regulators such as insulin, nonesterified fatty acids (NEFA) and triiodothyronine (T3) in low-calorie diet (LCD) for obese humans. DESIGN: Longitudinal study. SETTING: University and foundation hospitals. SUBJECTS: Ten obese men and 10 premenopausal obese women. INTERVENTIONS: Five men and five women took 800 kcal/day LCD and another five men and five women took 1400 kcal/day balanced deficit diet (BDD) during 4 weeks. RESULTS: Plasma leptin levels in the LCD group decreased more markedly (46.2+/-14.6 to 13.2+/-3.6 ng/ml) than that expected for the decrement in percentage fat (39.0+/-1.7 to 35.9+/-1.7%) and body mass index (BMI; 35.4+/-2.4 to 33.1+/-2.2 kg/m(2)), while that in the BDD group did not decrease significantly (14.9+/-3.5 to 13.4+/-2.8 ng/ml). The ratio of the decrease in leptin levels to that of BMI during the first week was significantly greater than that during the following 3 weeks (39.5+/-2.7 vs 29.3+/-2.1%, P=0.017). The plasma insulin and T3 levels also fell substantially in the first week and continued to decrease during the entire course. Plasma leptin levels measured weekly in each subject were correlated well with insulin (r=0.586, P=0.0003) and T3 (r=0.785, P=0.0004). Multiple regression analyses after adjustment for the time course and BMI revealed that serum levels of T3 were independently correlated with plasma leptin levels (r=0.928, P<0.0001). The plasma NEFA level was markedly elevated during the first 2 weeks and decreased thereafter. CONCLUSIONS: A rapid fall in leptin during the first week of LCD, coordinated by insulin, T3 and NEFA, should be beneficial for responding to decreased energy intake. Inversely, in view of the powerful effect of leptin on energy dissipation, the present findings suggest the potential usefulness of leptin in combination with caloric restriction for the treatment of obesity. SPONSORSHIP: The Ministry of Education, Culture, Sports, Science and Technology of Japan and the Ministry of Health, Labour and Welfare of Japan.

A histological study of calcium pyrophosphate dihydrate crystal-deposition disease.

Synovial, meniscal, articular cartilage, and other connective tissue from fifty-seven patients who had calcium pyrophosphate dihydrate crystal-deposition disease was examined by light microscopy, electron microscopy, and electron-probe microanalysis. Safranin O-positive hypertrophic chondrocytes that contained proteoglycans were observed in the tissues of each patient. Microcrystals that were suggestive of early precipitation of crystals were found in the degenerating matrix surrounding hypertrophic chondrocytes. The matrix contained electron-dense amorphous material, including proteoglycans and debris of cellular components. The microcrystals were often seen in contact with degenerating collagen fibers. There was never any histological evidence of formation of crystal in the areas that had no hypertrophic chondrocytes. Chondrocytes of this kind, surrounded by characteristic degenerating matrix, were never observed in the articular tissue from sixty-one patients who had only osteoarthritis. On the basis of our results, we speculate that electron-dense amorphous material containing proteoglycans and debris of cellular components, and the degenerating collagen fibers that were seen around the hypertrophic chondrocytes, may play important roles in the formation of calcium pyrophosphate dihydrate crystals.

Exercise testing, clinical, and angiographic characteristics of anginal patients with and without diabetes mellitus.

To elucidate the influence of coexisting diabetes mellitus (DM) on clinical and pathophysiologic characteristics in patients with coronary artery disease (CAD), the authors reviewed 1,211 consecutive patients who underwent coronary angiography (CAG) and selected 80 patients with significant CAD but without myocardial infarction, hypertension, or other heart diseases, who underwent both symptom-limited treadmill test (TM) and CAG within four weeks. DM was found in 22 of the 80 patients. No significant difference in the average number of diseased arteries of left ventricular ejection fraction at rest was found between DM patients and patients without DM (NDM patients). The incidences of exercise-induced ST depression and anginal pain revealed no difference between DM and NDM patients. Mean duration of exercise was shorter in DM patients (345 +/- 97 sec) than in NDM patients (423 +/- 162 sec, p less than 0.01). Furthermore, anginal pain during exercise occurred earlier in DM patients (187 +/- 68 sec) than in NDM patients (248 +/- 99 sec, p less than 0.05). No significant difference in double product or magnitude of ST segment depression at the onset of anginal pain was found between DM and NDM patients. However, heart rate responsiveness to exercise in DM patients was higher than that in NDM patients. These findings may indicate that pathophysiology of the heart in CAD patients with DM is affected not only by CAD itself but also by myocardial damage due to DM.

Geographic choroiditis and retinal vasculitis in rheumatoid arthritis.

A 37-year-old man developed geographic choroiditis and retinal vasculitis in the left eye while taking 3.5 mg/day oral prednisolone for rheumatoid arthritis. The choroidal lesions stopped growing when the dose of prednisolone was increased to 60 mg/day, while its tapering resulted in the recurrence and enlargement of the choroidal lesions to the macula. The patient experienced further recurrence twice in the following year. Indocyanine green angiography demonstrated the obstruction of choroidal arteries in addition to the complete obstruction of the choriocapillaris in a fresh lesion. This case was the first to have geographic choroiditis on the background of a systemic inflammatory disease.

Prevention of gastric ulcers in swine by feeding of sodium polyacrylate.

Five experiments involving 169 swine were conducted to determine the effects of 0.1% to 0.5% sodium polyacrylate (PANa) in rations of growing swine on weight gain, feed conversion, and occurrence of esophagogastric lesions. Seemingly, PANa prevented swine from developing esophagogastric ulcers. Esophagogastric ulcers or erosions occurred in 42.9% of the swine fed a PANa-free diet, but occurred in only 9.8% of those fed a diet containing PANa. Addition of PANa (0.1% to 0.5%) to the growing ration increased weight gain and feed conversion. The anti-ulcer effect of PANa was discussed.

An ultrashort 1-day protocol of Tc-99m tetrofosmin.

PURPOSE: This study describes a new 1-day protocol with Tc-99m tetrofosmin that requires only 100 minutes to obtain both stress and resting cardiac images by using a double-injection and subtraction method. METHODS: This procedure was performed in 48 consecutive patients. Rest-rest double injections were performed in eight patients (five men, three women; mean age, 69 +/- 9.8 years ) to evaluate count and image reproducibility (subprotocol A), and stress-rest and additional resting perfusion images (true rest) were done on a different day in 11 patients (five men, six women; mean age, 63 +/- 5.9 years) to confirm the validity of the new protocol (subprotocol B). RESULTS: Image quality scores of the resting image were excellent (35 of 48, or 72.9%), good (7 of 48, or 14.6%), fair (3 of 48, or 6.3%), and poor (3 of 48, or 6.3%). The scintigraphic findings with the new protocol corresponded closely with those of angiography in 26 of 34 cases (76.5%), with a tendency for underestimation (in 5 of 34 cases, or 14.7%) rather than overestimation (in 3 of 34 cases, or 8.8%). In subprotocol A, count reproducibility between the two resting images was excellent (r = 0.95; P < 0.0001); and in subprotocol B, the early-rest images were concordant visually and quantitatively with the true rest images (r = 0.89, P < 0.0001). CONCLUSION: Although there are some limitations, this protocol can be used as a routine stress-rest protocol.

Studies on the effects of microgravity on the ultrastructure and function of cultured mammalian cells.

Four cultures of monkey kidney cell line, JTC-12, were flown on the Spacelab-J (SL-J) mission during 8 days. The results of the present study showed that the space flight gave no essential effect on morphology, cell cycle, glucose consumption and urokinase production of the mammalian culture cell. However, the cell proliferation slightly decreased under microgravity. Moreover, the lack of gravity induced the trypsin-treated dissociated cells to keep floating in the culture medium. Therefore, the attachment of the cells onto the substratum was delayed, and that caused difficulties in subculturing the cells. The present research also offered some important information on techniques for establishment of cell cultures in space laboratories.

[Combination assay of IAP and ADA in hematologic malignancies].

We measured the levels of adenosine deaminase (ADA) and immunosuppressive acid protein (IAP) in 10 patients with acute myeloid leukemia (AML), 5 with acute lymphoblastic leukemia (ALL), 8 with chronic myeloid leukemia (CML), 7 with myelodysplastic syndrome (MDS), 5 with malignant lymphoma (ML), 3 with multiple myeloma (MM) and one with adult T cell leukemia. On admission, the level of IAP was abnormally high in all cases of AML and ALL 50% of CML cases, 71.4% of MDS cases, 60% of ML cases and none of MM cases. ADA was elevated in all cases of ALL, 77.8% of AML and CML cases, 57.1% of MDS cases, 60% of ML cases and 33.3% of MM cases. In 7 patients with AML, the level of IAP returned to normal when they achieved complete remission. On the other hand, the level of ADA had already returned to normal even during induction therapy. ADA showed a positive correlation with the absolute number of peripheral blasts and lactic dehydrogenase both in AML and ALL. These results suggest that ADA indicates the activity of leukemia and IAP indicates the immunocompetence of the host.