Cardiomyopathy and angiopathy in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes

In four patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS) in which mutated mitochondrial deoxyribonucleic acid was seen, hypertrophic cardiomyopathy and angiopathy was demonstrated by echocardiography, dipyridamole stress scintigraphy, and cardiac catheterization. On stress scintigraphy with dipyridamole, three patients showed hypoperfusion in the early image and a "filling-in" pattern in the late image. However, coronary angiography did not demonstrate narrowing of the large vessels in these patients. Light and electron microscopy of endomyocardial biopsy specimens indicated abnormal mitochondria, with marked increase in the number and size of mitochondria in endothelium. Modified Gomori's trichrome staining in biopsied endomyocardial specimens revealed a red-purple deposit similar in appearance of the ragged-red fibers in skeletal muscle, a characteristic finding of mitochondrial disease. Deterioration of complex I in the mitochondrial electron transfer system, which is widely observed in various mitochondrial diseases, appeared in biopsied skeletal muscle of our patients, indicating deficiency of some subunits of complex I. These results indicate that mitochondrial diseases such as MELAS show not only cardiomyopathy but also angiopathy. We speculate that proliferation of mitochondria leads to narrowing of the lumen of arterioles, which might be responsible for the ischemic findings observed scintigraphically.

[Longitudinal change in independence in the elderly--Kahoku Longitudinal Aging Study (KLAS)]

A community based study named Kahoku Longitudinal Aging Study (KLAS) was conducted since 1990 for the purpose of evaluating the comprehensive geriatric functional assessment (CGA) and preventing a decline in CGA in the community-dwelling elderly population. It was carried out in a Japanese rural town, in which 32% of the population was over 65 years of age. This study included a questionnaire about activity of daily living (ADL), information-related physical function, mental (cognitive and affective) and social functional domains. In addition to subjective informative instruments, various types of objective assessment such as quantitative neuro-behavioral function tests and medical examinations were performed. Subjects were all the eligible elderly aged over 65 years in the community. Although the ratio of subjects who were independent in ADL decreased with advancing age in both 1991 and 1993, the ratio of the independent elderly in ADL became significant higher (74%) in 1993 than in 1991 (71%). Scores on 2 kinds of neurobehavioral function tests in the 159 subjects aged over 75 years who attended the examination every year showed a significant and slight decrease during two years. However, some test indices significantly improved during the 2 years. These results suggested that age-related dependency in ADL and some kind of neurobehavioral functions might be prevented, in part, by health promoting education and improvement of life style.

Oxidative DNA damage induced by Cu(II)-oligopeptide complexes and hydrogen peroxide

At physiological pH values, Cu(II)-tetraglycine and Cu(II) complexes with peptides containing a histidyl residue at the N-terminal caused DNA strand breakage in the presence of H2O2, whereas Cu(II) complexes with peptides containing histidyl residue in the second or third position did not. Because of the correlation between the generation of hydroxyl radical and DNA strand scission, a mechanism for the reaction is proposed.

Nutritional support through percutaneous transhepatic internal drainage route in common bile duct cancer

A 69 year old female with a duodenal bulb obstruction due to direct invasion of common bile duct cancer who received total enteral nutrition through the route of percutaneous transhepatic internal drainage (PTID) was presented. The tip of PTID tube was placed over the duodeno-jejunal flexure. Jejunal infusion of all nutrients and the bile juice through this route kept her in good nutritional condition until the terminal stage of primary disease. This procedure did not cause the infection of the biliary system. Major problems, tube obstruction and diarrhoea, were easily resolved with the selection of an appropriate infusion schedule and nutrient concentration. We conclude that nutritional support through the PTID route is a beneficial means for compromised patients without laparotomy or hospitalization.

Enzymatic and genetic adaptation of soleus muscle mitochondria to physical training in rats

To evaluate the effects of physical training on mitochondrial gene expression and mitochondrial biogenesis in slow-twitch muscle, adult female Sprague-Dawley rats were trained for 3, 6, and 12 wk by running on a motor-driven treadmill (speed of 25 m/min and duration of 90 min/day, 5 days/wk), and the activities of citrate synthase, ubiquinol-cytochrome-c oxidoreductase, cytochrome oxidase, mitochondrial cytochrome b mRNA (by Northern blot analysis), and mitochondrial DNA (by slot-blot and Southern blot analyses) were measured in rat soleus muscle. A DNA probe for detection of mitochondrial mRNA and DNA was prepared from a 1,500-bp fragment of human mitochondrial DNA that included the coding region of the cytochrome b gene. Training for 3, 6, and 12 wk significantly increased the activities of citrate synthase (31, 28, and 47%, respectively), ubiquinol-cytochrome-c oxidoreductase (61, 63, and 77%, respectively), and cytochrome oxidase (25, 26, and 32%, respectively) in muscle. The concentration of cytochrome b mRNA in the muscle was proportionally elevated with the enzyme activities. On the other hand, the mitochondrial DNA concentration in the muscle was not altered by training for 3 or 6 wk but increased significantly after training for 12 wk (35% in the slot-blot analysis and 31% in the Southern blot analysis). These results suggest that an increase in the oxidative capacity of slow-twitch muscle by the relatively short-term training is regulated at the pretranslational step in mitochondrial protein synthesis but that the increase by the long-term training involves mitochondrial replication.

Pathophysiology and end-organ damage in elderly hypertensives

PATHOPHYSIOLOGY OF HYPERTENSION: Blood pressure increases with advancing age in most developed countries. The pathophysiology of elderly hypertension is characterized by changes in the structure and function of the cardiovascular system. Changes in arterial structure lead to a decrease in aortic compliance, which augments the aortic pressure component generated by the wave reflection mechanism. The age-related increase in the reflected-wave component of arterial pressure may contribute, at least in part, to the age-related rise in systolic blood pressure. Disproportionately elevated systolic blood pressure in the elderly may account for the progressive increase in left ventricular mass with advancing age. In addition to the changes in vascular and cardiac structures, the haemodynamic function of elderly hypertensives is characterized by increased peripheral resistance as well as reduced cardiac output, renal blood flow and intravascular volume. In contrast to younger hypertensives, the sympathetic and renin-angiotensin systems may not be major factors in the genesis of high peripheral resistance in this patient group. END-ORGAN DAMAGE: The most important end-organ damage in elderly hypertensives is left ventricular hypertrophy with or without coronary heart disease, cerebrovascular disease or renal impairment. Furthermore, this end-organ damage is frequently asymptomatic (silent). The prevalence of silent cerebrovascular disease in particular is surprisingly high in this elderly population. Asymptomatic cerebrovascular disease has been shown to be associated with various cardiovascular risk factors, and depressed neurobehavioural function. Diurnal blood pressure variations appear to be related to end-organ damage. The presence of occult end-organ damage and co-existing diseases common in elderly hypertensives has important clinical implications in the management of this disorder.

Decrease in cytochrome c oxidase and cytochrome oxidase subunit I messenger RNA levels in preeclamptic pregnancies

OBJECTIVE

To elucidate the possible relation between mitochondrial gene expression and placental dysfunction.

METHODS

We measured the activity of cytochrome c oxidase and the expression of cytochrome oxidase subunit I in mitochondria from human placentas of women whose gestations were appropriate for gestational age (AGA) and those with preeclampsia. In addition, the amounts of normal mtDNA and deleted mitochondrial DNA were examined in the two groups by Southern blot analysis and polymerase chain reaction, respectively.

RESULTS

Cytochrome c oxidase activity and expression of cytochrome oxidase subunit I were significantly lower in the preeclamptic group than in the AGA group. There were no differences between the groups in the amounts of mitochondrial DNA. In addition, no mutant mitochondrial DNA with a 4977-base pair deletion was detected in the two groups.

CONCLUSION

These results suggest that reduced expression of the mitochondrial gene is involved in placental dysfunction in preeclamptic pregnancy.

[A clinical study of renal hemodynamics in patients with lupus nephritis]

This study was designed to evaluate the clinical significance of glomerular filtration rate (GFR) and renal plasma flow (RPF) in 122 patients with lupus nephritis. All patients had definite clinical evidence of active lupus nephritis, including urinary and immunological abnormalities. The average RPF was 634.5 +/- 171.4 ml/min in systemic lupus erythematosus patients and 537.4 +/- 141.9 ml/min in 37 age-and sex-matched patients with primary glomerular disease (PGD) (p < 0.01). A fall in GFR, accompanied by massive proteinuria and hypocomplementemia, was observed frequently in patients with class IV lupus nephritis (diffuse proliferative GN). In contrast, RPF did not change in most patients except in some with increased RPF. No correlation was noticed between RPF and proteinuria or immunological abnormalities. As a result, a marked fall in filtration fraction (FF) was observed frequently in class IV lupus nephritis, and was correlated significantly with urinary and immunological abnormalities. Follow-up data during treatment in the active to inactive phases (average 7.8 months) were available for 39 patients. The average GFR increased significantly from 56.9 +/- 31.4 ml/min in the pre-treatment stage to 74.5 +/- 26.9 ml/min in the post-treatment stage, accompanied by an improvement in proteinuria and hypocomplementemia. On the other hand, RPF decreased significantly from 521.3 +/- 217.1 to 437.6 +/- 156.2 ml/min, so that FF increased significantly as the renal and immunological parameters normalized. Additionally, the renal function was evaluated in 11 patients during the exacerbation of lupus nephritis.(ABSTRACT TRUNCATED AT 250 WORDS)

Synthesis of new oligopeptides and their scavenging abilities against active oxygen species

The reactivities of new synthetic oligopeptides containing cysteine or histidine towards active oxygen species such as superoxide (O2-) and hydroxyl radical (.OH) were investigated by an electron spin resonance (ESR)-spin trapping method. At physiological pH values, these oligopeptides greatly suppressed the generation of .OH from the reaction of Cu(en)2 (en: ethylenediamine) with hydrogen peroxide (H2O2), although these oligopeptides did not scavenge O2-. The antioxidant mechanism of these oligopeptides is discussed.

Activation of hydrogen peroxide by copper (II) complexes with some histidine-containing peptides and their SOD-like activities

The reactivities of copper(II) complexes with histidine-containing oligopeptides towards active oxygen species such as hydrogen peroxide (H2O2) and superoxide ion (O2-) were investigated by electron spin resonance (ESR)-spin trapping and thiobarbituric acid (TBA) methods. At physiological pH values, Cu(II) complexes with oligopeptides containing histidyl residue at the N-terminal could more easily activate H2O2 to yield hydroxyl radical (.OH) than other Cu(II)-oligopeptide complexes containing histidyl residue in the second or third position. Further, it was suggested that since all Cu(II)-oligopeptide complexes examined could scavenge O2-, these complexes have SOD-like activities.

Strand asymmetry in human mitochondrial DNA mutations

Replication of mitochondrial DNA is highly asymmetric between the heavy (H) and the light (L) strands. The parental H strand is displaced by the daughter H strand and remains in a single-stranded state until the daughter L strand is synthesized. To examine the effect of this asymmetric replication on mutagenesis, we determined sequences of mtDNAs from 43 human individuals. Occurrence of nucleotide substitutions at 4-fold degenerate sites was distinctly asymmetric between the two strands: G-->A and T-->C transitions were 9- and 1.8-fold more frequent on the L strand than on the H strand, respectively. This nucleotide substitution bias is consistent with the T and G abundance of the H strand as well as the A and C abundance of the L strand.

Fragmentation of human heart mitochondrial DNA associated with premature aging

Point mutations, oxygen damage and deletions in the heart mitochondrial (mt) DNA of a 19-year-old male patient with premature aging, who died of mitochondrial cardiomyopathy, were comprehensively analyzed. With total base-sequencing, one syn- mutation in the tRNA(Asp) gene and one mit-mutation in the ND3 gene were demonstrated. Using microHPLC/MS, 0.20% of the total deoxyguanosine (dG) were proved to be converted into its hydroxy-radical adduct, 8-hydroxy-dG, of which amount corresponds to that in normal subjects of 78 years old. The total detection system for mtDNA deletions, using 180 kinds of primer pairs, revealed extensive fragmentation of mtDNA; 235 types of deletions existed with various sizes, 97 of which yielded mtDNA minicircles lacking both of the replication origins of light- and heavy-strands. Deleted mtDNA accounted for 84% of the total mtDNA. In a man died from an accident at age 28 having almost the same mtDNA genotype except syn-, 50 types of deleted mtDNA, accounting for 15% of the total, were detected in his heart mtDNA. These results will present a clue to an unidentified mechanism of somatic mtDNA replication and the molecular basis of aging heart.

Thrombin generation as an acute effect of cigarette smoking

The effects of acute smoking on hemostatic functions were investigated in healthy young volunteers. Immediately after the volunteers smoked, a significant increase in blood pressure and heart rate was accompanied by a rise in plasma epinephrine. Fibrinopeptide A and thrombin-antithrombin III complex as markers of thrombin generation in vivo were significantly increased after smoking. The increase in thrombin-antithrombin III complex was significantly correlated with that of plasma epinephrine. Both antigen and activity of tissue plasminogen activator and plasmin-inhibitor complex as markers of fibrinolytic activity in vivo were markedly increased after smoking, whereas D-dimer, plasminogen activator inhibitor antigen, fibrinogen, and both beta-thromboglobulin and platelet factor 4 as markers of platelet activation in vivo were not changed. No effects were observed after sham smoking under exactly identical conditions in the same subjects. Thus thrombin generation was observed as acute hemostatic effects of smoking. Enhanced fibrinolytic response may counteract an increased procoagulant activity. Patients with vascular disease might be more susceptible to a state of disequilibrium in favor of coagulation, which may partly explain a mechanism by which cigarette smoking leads to cardiovascular morbidity and mortality.

A complete cDNA sequence for core I protein subunit of human ubiquinol-cytochrome c reductase

Core I protein is the largest subunit of ubiquinol-cytochrome c reductase. We have isolated a complete cDNA clone of 1575 bp encoding the precursor to this protein by screening a human fibroblast cDNA library. Nucleotide sequence comparison showed that the human core I protein cDNA is about 85% homologous with the reported bovine counter part but with a large difference in the length of coding region which consists of 480 amino acids in human and 362 amino acids in bovine. Human core I protein is presumed to contain a presequence of 34 amino acids. Amino acid sequence alignment study showed that the predicted human core I protein has a significant homology with other members of matrix processing peptidase (MPP) and processing enhancing protein (PEP) family.

Laser high performance liquid chromatography determination of prostaglandins in nasal lavage fluid in allergic rhinitis

This study was designed to analyse prostaglandins (PGs) in human nasal lavage fluid using the combination of microcolumn high performance liquid chromatography and a He/Cd laser induced fluorescence detection system. Forty-seven patients with allergic rhinitis and 12 healthy volunteers were investigated. Four species of PG, i.e. PGD2, PGE2, PGF2 alpha, and 6-keto-PGF1 alpha were detected in the nasal lavage fluid. Concentrations of PGD2 (1.33 +/- 0.17 nmol/ml) and PGE2 (0.87 +/- 0.11 nmol/ml) in nasal lavage fluid from patients with allergic rhinitis (the allergy group) were significantly increased compared with those of volunteers (the control group, 0.23 +/- 0.16 nmol/ml, 0.29 +/- 0.19 nmol/ml, respectively). On the other hand, no significant differences were observed in concentrations of either PGF2 alpha or 6-keto-PGF1 alpha between the control group and the allergy group. Histamine concentration in nasal lavage fluid was significantly increased in the allergy group (53 +/- 7.6 nmol/l) compared with the control group (3.4 +/- 1.0 nmol/l). No significant correlation was observed between PGD2 and histamine concentration (r = 0.24), or between PGE2 and histamine concentration (r = 0.08) in nasal lavage fluid from patients with allergic rhinitis. Treatment with oxatomide, an anti-histamine and anti-allergic drug, significantly improved symptom scores, but did not alleviate them completely. Concentrations of each PG detected in nasal lavage fluid did not change significantly after oxatomide treatment. It is concluded that, not only histamine but also PGs, particularly PGD2 and PGE2, might be involved in the genesis of allergic rhinitis.

A wild-type mu s C-terminal gene is expressed in Bloom's syndrome cells

Selective IgM deficiency is found commonly in patients with Bloom's syndrome (BS). Serum IgM concentrations were low though serum IgG and IgA concentrations were normal in both patients with BS included in the study. In a previous study the authors showed that selective IgM deficiency in BS is due to an abnormality in the maturation of surface IgM-bearing cells into IgM-secreting cells and a failure of secreted mu (mu s) mRNA synthesis. The membrane-bound mu (mu m) and mu s mRNA are produced from transcripts of a single immunoglobulin mu gene by alternative RNA processing pathways. The control of mu s mRNA synthesis depends on the addition of poly(A) to mu s C-terminal segment. The study described here demonstrated that there was no mutation or deletion in the sequence including mu s C-terminal coding sequence, the RNA splice site (GG/TAAAC) at the 5' end of mu s C-terminal segment, and the AATAAA poly(A) signal sequence, and second GT-rich element immediately down-stream of the cleavage site in both patients.

Acute and chronic effect of ethanol on the occurrence of alloxan diabetes in rats

We investigated the chronic and acute effect of ethanol on alloxan-induced diabetes in rats. When 1 ml/100 g b.w. of 35% ethanol solution was intraperitoneally injected into rats 10 min before intramuscular injection of alloxan, the alloxan-induced diabetes was completely prevented at the alloxan dosis (150, 200 mg/kg b.w.) at which the disease is unfailingly induced in control rats. This finding confirmed the results of Heikkila, Barden and Cohen. On the other hand, when rats were given 10% ethanol solution instead of water for 40 straight days, alloxan at a dose of 130 or 140 mg/kg caused diabetes in all cases, whereas no controls developed diabetes. This demonstrable effect of the promotion of alloxan-induced diabetes by chronic alcohol administration was the exact opposite of the acute effect of alcohol. We discussed the contradictory action of ethanol in relation to the occurrence of alloxan diabetes in rats.

Effects of FK506, an immunosuppressive agent, on genesis of water-immersion stress-induced gastric lesions in rats

We examined the effects of FK506, an immunosuppressive agent, on the genesis of water immersion stress-induced gastric lesions in rats. Using high-performance liquid chromatography, four kinds of prostaglandins, ie, 6-keto-prostaglandin F1 alpha, prostaglandin F2 alpha, prostaglandin E2, and prostaglandin D2, were detected, and no leukotrienes were detected in gastric mucosa in rats without stress. After 6 hr of stress, gastric lesions developed with decreases in all prostaglandin contents, and the emergence of peptide leukotrienes was observed. Intramuscular administration of FK506 (0.1, 0.25, 0.5, 1.0, and 2.0 mg/kg) reduced lesion index dose-dependently. Administration of FK506 at doses over 0.25 mg/kg decreased all prostaglandin contents, but did not affect the increase in leukotriene contents. Pretreatment with famotidine or omeprazole reduced lesion index, and the protective effects were equivalent to those of 1.0 mg/kg of FK506, although FK506 did not affect gastric secretion during water-immersion stress. Water-immersion stress did not change the activities of xanthine oxidase in either stomach or serum. Polyoxyethylene-modified superoxide dismutase did not prevent gastric lesions. Water-immersion stress significantly increased myeloperoxidase activity in gastric mucosa, and FK506 reduced the increase in myeloperoxidase activity induced by stress. From our results, other factors besides gastric acid secretion and tissue eicosanoid contents, such as chemoattractant factor, might also be involved in the genesis of water-immersion stress-induced gastric lesions in rats.

Mitochondrial cardiomyopathy

Accumulating evidence emphasizes the role of genetic factors in the development of cardiomyopathy. Mitochondrial cardiomyopathy is defined as cardiomyopathy caused by mitochondrial DNA mutations. The rate of mitochondrial DNA mutation is estimated to be much higher than that of nuclear DNA. It has been demonstrated that mutations of mitochondrial DNA are found in a variety of diseases, suggesting a new concept of mitochondrial disease. This contribution reviews the concept, molecular genetics, family history, pathology, clinical symptoms, diagnosis and therapy of mitochondrial cardiomyopathy.

[Effect of nifedipine and enalapril on cardiac autonomic activity in elderly hypertensive patients]

To clarify the effect of the calcium antagonist Nifedipine and the ACE inhibitor Enalapril on cardiac autonomic activity, power spectral analysis of heart rate variability (PSA) was conducted in 39 elderly patients with essential hypertension (mean age: 63: +/- 11 years) before and after treatment. Twenty patients were treated with 10-20 mg of Nifedipine (N group) and 19 with 5 mg of Enalapril (E group) for 3 months. beta-blocker (Atenolol 12.5 mg) was added to Nifedipine in 12 patients of the N group for 1 month, and the modified effect of Atenolol on cardiac autonomic activity was also evaluated. Blood pressures were significantly reduced in both N and E groups after the treatment. The low frequency component (LF) in PSA, which was considered to be a quantitative marker of cardiac sympathetic activity, increased significantly and the high frequency component (HF), which was a marker of cardiac parasympathetic activity, significantly decreased with increase of PNA levels in N group after the treatment. However, the LF decreased significantly after addition of Atenolol. On the other hand, there was little significant change in LF and PNA in E group. These results suggest that Nifedipine increased cardiac sympathetic activity and that Enalapril had little influence on the cardiac sympathetic tone, while both antihypertensive agents significantly reduced blood pressure itself.

Inactivation of gamma-hemolysin H gamma II component by addition of monosialoganglioside GM1 to human erythrocyte

The Staphylococcal toxins leukocidin and gamma-hemolysin consist of two protein components: F and S in leukocidin and H gamma I and H gamma II in gamma-hemolysin. The two toxins share one component (F = H gamma I). We found that the H gamma II component was completely inactivated by the addition of monosialoganglioside GM1 at the molar ratio of 1:1. Disialogangliosides GD1a and GD1b had little effect on the inactivation of H gamma II. The molar ratios of GD1a and GD1b to H gamma II needed for maximum inactivation were 30:1 and 100:1, respectively. Related glycolipids caused little if any inactivation. H gamma II bound to GM1 to form H gamma II-GM1 complexes. Analysis of the intrinsic aromatic amino acid fluorescence in H gamma II and H gamma II-GM1 with 280 nm as the excitation wavelength showed that GM1 in the complex reduced the fluorescence intensity of H gamma II by 12% without changing the wavelength of maximum emission (325 nm). We concluded that GM1 is a receptor of the H gamma II component on human erythrocytes and that H gamma II takes on a different conformation when it binds to GM1.