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Biomedical subjects

A Maki

Publications and source records attributed to A Maki.

At least 73 records · Page 4Linked to original sources
PubMed1992

Right ventricular wall motion disturbance and determinants of the appearance of hemodynamic right ventricular infarction.

In order to elucidate the mechanisms of the appearance of hemodynamic right ventricular infarction (RVI), we studied right and left ventriculograms and hemodynamic findings in 52 patients with acute inferior myocardial infarction. Right ventricular wall motion disturbance (RVWMD) was detected in 69% of patient but hemodynamic RVI was observed only in 16%. Among patients with RVWMD, there was no significant difference in right ventricular ejection fraction between those with (group III) and without (group II) hemodynamic RVI, suggesting that right ventricular (RV) systolic dysfunction does not independently produce hemodynamic RVI. Right ventricular end-diastolic volume index was similar in groups II and III in spite of higher mRA in group III. The result suggested that the RV compliance of group III was decreased. Heart rate (HR) was significantly lower in group III than in group II. Not only physiologic pacing but also VVI pacing significantly improved hemodynamics in patients with hemodynamic RVI. A positive correlation between HR and cardiac index was observed (r = 0.56, p < 0.001) in patients with RVWMD. Decreased RV compliance and bradycardia were considered to be determinants of the appearance of hemodynamic RVI. Volume loading did not improve hemodynamics significantly in patients with hemodynamic RVI.

Angiography, Digital Subtraction↗
PubMed1992

[The treatment of choice in deep vein thrombosis of the lower extremity].

Of 67 patients with acute deep vein thrombosis of the lower extremity (DVT), 43 patients were treated by venous thrombectomy and 24 patients were managed by conservative treatment. The clinical effect of thrombectomy was evaluated by analyzing follow-up results in the 2 groups. The cumulative incidences of pigmentation and stasis ulcer at the 5th year were 2.7% and 0% respectively in the thrombectomy group, and 24.3% and 10% respectively in the conservative treatment group. Pigmentation and stasis ulcer were significantly more frequent in the conservative treatment group (p < 0.01). It is concluded that venous thrombectomy is superior to conservative treatment to prevent late postthrombotic sequelae. Protein C, protein S and plasminogen were assayed in 40 DVT patients to determine the incidence of hypercoagulable state in DVT. Congenital deficiency or abnormality were found in 15 patients (37.5%). In such DVT patients with thrombophilia anticoagulant prophylaxis should be continued to decrease a risk of rethrombosis.

Adult↗
PubMed1991

Oxidative injury induces influx-dependent changes in intracellular calcium homeostasis.

Understanding of the mechanisms of cell injury and cell death is fundamental to the understanding of both protection against and initiation of cell injury and cell death. We subjected primary cultures of proximal tubular epithelium (PTE) from adult rats to an exogenous oxidative stress, generated by xanthine/xanthine oxidase (X/XOD), and studied its effect on the concentration of cytosolic ionized calcium ([Ca2+]i) by means of digital imaging fluorescence microscopy (DIFM) using a cytosolic calcium probe, fura-2. Exposure to 25 mU/ml X/XOD caused notable increases in [Ca2+]i detectable within 15 sec and increasing to micromolar levels with time. Experiments with Ca(2+)-free medium containing ethylene glycol-bis(beta-aminoethyl ether)N,N,N',N'-tetraacetic acid (EGTA) showed that the increase of [Ca2+]i was due to influx from the extracellular space. Smaller and slower increases in [Ca2+]i were seen after exposure to lower concentrations of X/XOD (5 and 10 mU/ml). PTE injury and killing were assessed by measuring the release of cytosolic lactate dehydrogenase (LDH), exclusion of trypan blue, and observation of morphologic changes. Exposures to the 25 mU/ml concentration of X/XOD caused significant LDH release after 2 hr and correlated with trypan blue staining of exposed cells. Again, lesser concentrations of X/XOD resulted in a slower release of smaller amounts of LDH, and thus delayed trypan blue staining. Cytoplasmic bleb formation was seen by phase microscopy within minutes of exposure to 25 mU/ml, followed by cell rounding, retraction, and disintegration. Transmission electron microscopy revealed a progression of changes characteristic of lethal cell injury, beginning with dilatation of the endoplasmic reticulum, detachment of ribosomes, condensation of mitochondria, and chromatin clumping and terminating with mitochondrial swelling and formation of intramitochondrial flocculent densities. These studies clearly show that notable increases of [Ca2+]i precede both sub-lethal and lethal changes in rat PTE. These results indicate that interventions designed to minimize or to accelerate calcium entry could be of importance in cell preservation or cell killing, respectively, and therefore to therapeutic strategies for myocardial infarction, stroke, or shock in the former instance and for cancers in the latter.

Animals↗
PubMed1990

[Clinical investigation of hepatectomies for hepatocellular carcinoma--significance of extended hepatectomy for advanced hepatocellular carcinoma].

Although the diagnostic methods for hepatocellular carcinoma (HCC) are now being improved, there are still many cases detected at advanced stage. We, based on the Redox theory and using a technique of vascular surgery and liver transplantation, made it possible to perform the extended hepatectomy more actively even in the advanced cases which were previously considered to be in-operable. We report these extended hepatectomies in this paper. From January 1985 to August 1989, we performed 263 hepatectomies for HCC. Out of these 263 cases, we examined 208 cases which had an interval more than three months from the time of the operation and had exact follow-up data at the end of August 1989. There are 57 extended hepatectomies and they consist of 4 groups as follows. 1) Multiple group (14 cases): the operation for the cases with multiple daughter nodules in both lobes besides the main tumor. 2) Thrombus group (30 cases): the operation for the cases with portal tumor thrombus in the first branch or the main trunk of portal vein. 3) IVC group (4 cases): the operation adding resection and reconstruction of IVC because tumor was hardly fixed to the wall of IVC. 4) Recurrence group (9 cases): the operation for hepatic recurrence. Six cases of the Multiple group survived more than one year and one case is still alive more than two years after surgery. The 6-months, 1-year and 2-year cumulative survival rates of the Multiple group are 50.5%, 38.3%, and 8.5% respectively and these results are better than other reports. Forty-three hepatic recurrences were observed in 138 cases whose tumor was completely resected macroscopically.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Cytochrome c oxidase activity in human liver specimens. An index of prognosis for hepatic resection.

Cytochrome c oxidase activity, measured as Vmax (nanomoles of cytochrome c oxidized per second per milligram of protein) and Michaelis constant (Km) (micromoles per liter), was measured spectrophotometrically in human liver specimens obtained by needle biopsy from 43 patients. In 16 normal livers, the Vmax and Km values ranged from 1.26 to 2.25 nmol/s per milligram of protein and from 2.78 to 3.95 mumol/L, respectively. In 27 patients with liver cirrhosis or chronic hepatitis, these values ranged from 1.60 to 3.80 nmol/s per milligram of protein and from 2.80 to 6.50 mumol/L, respectively. Patients with Vmax above 2.5 nmol/s per milligram of protein or Km above 5.0 mumol/L had a high incidence of postoperative complications even after minor hepatic resection. By contrast, even patients with liver cirrhosis or chronic hepatitis could tolerate major hepatic resection as long as their Vmax and Km values were within the normal range. These findings indicate that the cytochrome c oxidase activity in liver specimens can serve as a prognostic sign in hepatic resection even in patients with liver cirrhosis or chronic hepatitis.

Adult↗
PubMed1990

Changes in arterial ketone body ratio in the phase immediately after hepatectomy. Prognostic implications.

Postoperative fluctuations of the ketone body ratio in arterial blood (acetoacetate/3-hydroxybutyrate), reflecting hepatic mitochondrial redox potential, were analyzed in 266 hepatectomized patients in relation to their prognosis. Changes in ketone body ratio were classified into the following two types: a primary decrease at the end of operation and a secondary decrease after transient recovery. Patients were classified into three groups by the primary decrease of ketone body ratio: group 1 (183 cases) with ketone body ratio above 0.7, group 2 (49 cases) between 0.7 and 0.4, and group 3 (34 cases) below 0.4 Ketone body ratio was restored to above 0.7 in 2.5 +/- 0.2 days (mean +/- SE) in all group 2 patients. However, though it was restored within 4.5 +/- 0.4 days in 26 group 3 patients, the other 8 died of multiple organ system failure in 7.4 +/- 2.8 days without recovery of ketone body ratio. This was followed by a secondary decrease in ketone body ratio to below 0.7 in 94 patients, concomitant with complications. The degree of the secondary decrease was positively correlated with that of the primary decrease. In the secondary decrease, of 42 patients with ketone body ratio below 0.4, 28 died of multiple organ failure. Total mortality was 7% in group 1, 12% in group 2, and 50% in group 3. It is suggested that the primary decrease in ketone body ratio at the end of operation is a decisive factor in the prognosis for hepatectomized patients.

Adult↗
PubMed1990

Effects of intra-arterial chemotherapy with a new lipophilic anticancer agent, estradiol-chlorambucil (KM2210), dissolved in lipiodol on experimental liver tumor in rats.

Anticancer effects and biodistribution of a new lipophilic anticancer agent, estradiol-chlorambucil (KM2210), dissolved in lipiodol (LPD) were investigated as an intra-arterial chemotherapy (IAC) on Walker 256 carcinosarcoma grown in the liver of 136 Wistar rats. All rats treated with KM2210 (10 mg)-LPD survived for 90 days after administration, whereas none of the rats with LPD alone were alive for more than 19 days. Histological examination revealed that there was no viable tumor cell in the encapsulated necrotic tumor at 21 days after administration. There was no significant liver dysfunction or leukopenia due to KM2210. The biodistribution study using [14C, 3H]KM2210-LPD solution showed that KM2210 accumulated selectively in tumor and that the tumor-to-normal-liver and tumor-to-blood ratios were 10 and 1,000, respectively, at 21 days after administration. These results suggest that KM2210 has potential clinical application in the treatment of human liver cancer.

Animals↗
PubMed1990

Content and distribution of vasoactive intestinal polypeptide (VIP) in cavernous tissue of human penis.

Penile erection is controlled by a valvular structure in the helicine artery in humans. The opening and closing of this valve are believed to be regulated by the autonomic nervous system, especially through the release of vasoactive intestinal polypeptide (VIP). We determined the content of VIP in cavernous tissue in 18 impotent patients and in 5 normal controls by radioimmunoassay, and we examined the distribution of VIP-ergic nerve fibers in cavernous tissue by an immunohistochemical method. As a result, it was found that the lower penile VIP content was more frequent among patients with organic impotence than among the controls. Furthermore, VIP-ergic nerve fibers were seen to be diffusely and loosely distributed in a large number of organic impotence patients. These findings suggest that organic impotence in some patients may be due to decreases in the VIP content and in VIP-ergic nerve fibers.

Adolescent↗
PubMed1990

Response of hepatic mitochondrial redox state to oral glucose load. Redox tolerance test as a new predictor of surgical risk in hepatectomy.

The redox tolerance test introduced in this article attempts to quantify the deterioration of hepatic mitochondrial energy metabolism by measuring the changes in arterial ketone body ratio in response to 75-g oral glucose loading, and is discussed in relation to its predictive value for assessing surgical risk in hepatectomy. The indicator, called redox tolerance index (RTI), represents a 100-fold cumulative enhancement of ketone body ratio relative to glucose level (100 x delta KBR/delta glucose). The redox tolerance index was significantly different between 31 liver cirrhotics and 10 normal volunteers (p less than 0.001). Subjects were divided into three classes (I: RTI greater than or equal to 1.0, II: 0.5 less than or equal to RTI less than 1.0, III: RTI less than 0.5). Postoperative mortality was significantly different among the three classes in 127 hepatic resections (chi 2 = 9.843, p less than 0.01). Of 97 hepatocellular carcinoma cases, major hepatic resections in class III showed significantly higher postoperative morbidity and mortality rates (p less than 0.05 and p less than 0.05, respectively). The present findings indicate that RTI based on redox theory is of potential value in predicting posthepatectomy outcome.

Carcinoma, Hepatocellular↗
PubMed1990

Relation between toxicity and carcinogenesis in the kidney: an heuristic hypothesis.

Cellular toxicity and cellular carcinogenesis are closely linked. In the kidney, this relationship has been emphasized by the recent discovery of a number of putatively non-mutagenic chemicals that result in acute and chronic toxicity and ultimately in carcinogenesis, especially in the male rat. Many, but not all such compounds, result in renal PTE phagolysosomal overload. At the same time, known metabolites of other carcinogens, e.g., HCBD and FBPA, result in acute renal injury and/or necrosis, followed by chronic tubular disease, interstitial nephritis, and ultimately carcinogenesis. A series of cell mechanisms have been suggested that lead from acute cell injury to altered control of cell division. These mechanisms appear to involve ion deregulation, (especially [Ca2+]i) resulting from a variety of continued injuries, (e.g., oxidative stress from inflammatory cells) and ultimately leading to altered gene expression.

Animals↗
PubMed1990

[Effects of anti-androgens on sexual function. Double-blind comparative studies on allylestrenol and chlormadinone acetate Part I: Nocturnal penile tumescence monitoring].

Allylestrenol (ALE) and chlormadinone acetate (CMA) were administered to patients with prostatomegaly by the double-blind method, and the effects of these antiandrogens on their sexual function were objectively compared. Each agent was orally administered to 58 patients in a dosage of 50 mg/day for 12 consecutive weeks. For the objective evaluation of the sexual function, nocturnal penil tumescence (NPT) was measured using an erectometer. For the subjective evaluation the conventional interview method was employed. The levels of hormones relating to sexual function were also determined. A decrease in NPT was noted in both the ALE and CMA groups, but the degree of the decrease was significantly smaller in the ALE group than in the CMA group (p less than 0.001). The results of the interview, revealed a large between the two drug groups; in the CMA group, marked worsening for all items. In the determination of hormones, levels of luteinizing hormone, follicle stimulating hormone, testosterone and estradiol were decreased in both drug groups, while the prolactin level was increased in both groups. The changes in the testosterone, estradiol and prolactin levels in the CMA group were significantly dominant compared with those in the ALE group. In addition, drop-out cases due to a decrease in the sexual function numbered 7 (12.1%) in the CMA group, while there were no such drop-out cases in the ALE group; the difference in the drop-out rate was thus significant. In conclusion, ALE's effects on the sexual function were concluded to be smaller than those of CMA.

Aged↗
PubMed1990

[Effects of anti-androgens on sexual function. Double-blind comparative studies on allylestrenol and chlormadinone acetate. Part II: Self-assessment questionnaire method].

Allylestrenol (ALE) and chlormadinone acetate (CMA) were administered to patients with prostatomegaly by the double-blind method, and a self-assessment questionnaire method developed by the authors was used to study the influence of these two antiandrogens on their sexual function. Each test drug was orally administered to 58 patients, in a daily dosage of 50 mg for 12 consecutive weeks. The questionnaires consisted of 6 categories each consisting of 5 questions, or 30 questions in total. The 6 categories were "sexual desire," "erectile capacity" and "ejaculation," which relate to the sexual function, and "living environment (including the frequency of sex)," "dysuria" and "dummy (personality)." Each question was graded into 0-10 points, and each patient was requested to circle the number which best described his status. The scores were compiled and statistically analyzed. Many patients were senile. Evaluable answers were obtained for 99 (85.3%) of the 116 patients. Factor analysis based on the preadministration scores confirmed the contents of the questionnaires to be appropriate for the objectives of the present study. Multiple regression analysis revealed a high correlation between the self-assessment scores and objective data (nocturnal penile tumescence values; NPT values) when dropout cases due to a decrease in the sexual function and non-replying cases were excluded. The self-assessment questionnaire method was concluded to be as useful an objective test method as the NPT measurement for examining the sexual function. Aggravation of the "frequency of urination during night" was conspicuous in the CMA group, and there was a significant difference (p less than 0.05) in this parameter between the two groups. Except for this parameter, dysuria was improved in both administration groups, and there was no significant difference in the efficacy of the two drugs. Both drugs tended to suppress overall sexual function, but the suppression was less severe in the ALE group. Especially the suppression was significantly (p less than 0.05) lower in the ALE group regarding the 3 parameters of "contact sexual arousal," "contact erection" and "morning erection", which are included in the category of "sexual desire" or "erectile capacity." Also, suppression of "frequency of sex" and "intensity of sexual desire" tended to be lower in the ALE group at a level of significance of p less than 0.1. Regarding questions in the category of "ejaculation," the incidence of non-replies was high in both groups, but its rate was higher in the CMA group.

Adult↗