Verapamil induced reduction of the myocardial beta-adrenoceptor density in BIO 14.6 cardiomyopathic Syrian hamsters

In general, it is recognized that prolonged exposure to catecholamine leads to a reduction in the beta-adrenoceptor density (downregulation). However, it has been previously reported that the myocardial beta-adrenoceptor densities and norepinephrine levels significantly increase in the hearts of BIO 14.6 cardiomyopathic hamsters in the early stage. The mechanism of the increased beta-adrenoceptor density is not clearly elucidated, and it can not be excluded that this phenomenon may be a secondary effect. The purpose of this study was to assess the effect of verapamil on the density of beta-adrenoceptors in the heart of BIO 14.6 cardiomyopathic hamsters. The total number of beta-adrenoceptors in untreated BIO 14.6 hamsters was significantly higher at 90 days of age (30.4 +/- 2.2 v.s. 25.9 +/- 1.4 fmol/mg protein, p < 0.05). BIO 14.6 hamsters received daily intraperitoneal injections of 5 mg/kg verapamil for 70 days, from an age of 20 days. Verapamil protected against progressive myocardial damage (total damage; 8.2 +/- 0.7 v.s. 0.4 +/- 0.2%/area, p < 0.05) and the myocardial beta-adrenoceptor density returned to that of the normal control group (26.9 +/- 3.0 fmol/mg protein). Conversely, verapamil did not have an effect on the number of myocardial beta-adrenoceptors in normal golden hamsters. This study showed that verapamil protected against progressive myocardial damage and myocardial beta-adrenoceptor density returned to those of normal hamsters. These results suggest that an increased number of beta-adrenoceptors in the early stage of BIO 14.6 cardiomyopathic hamsters may be involved in the secondary pathogenesis of cardiomyopathy.

Clinical application of percutaneous left ventricular support with a centrifugal pump

A percutaneous left ventricular support (PLVS) system can play an important role in the short-term support of patients with severe heart failure, but these devices are not available for clinical use. We devised a new transseptal left atrial (LA) cannula for PLVS without thoracotomy. The cannula is 21 Fr in size (internal diameter: 5.3 mm) and 65 cm in length. This transseptal LA cannula can be inserted easily into the left atrium under fluoroscopy, by the usual transseptal technique, using a conventional Brockenbrough's needle. PLVS was used in two patients who developed cardiogenic shock following acute myocardial infarction and underwent resuscitation using percutaneous cardiopulmonary support (PCPS). The patients could not be weaned from PCPS even after successful percutaneous transluminal coronary angioplasty (PTCA), and PLVS provided 3.0 L/min of assist flow. The duration of PLVS was 114 and 92 hr. Both patients were weaned from PLVS, and one survived. There were no complications related to the PLVS. PLVS with a new transseptal LA cannula may be effective and useful for patients with severe heart failure.

Lithocholic acid-sensitive mutant cells isolated from Chinese hamster ovary cells are cross-sensitive to cytoskeleton-disturbing agents

The lithocholic acid-sensitive mutant cells were isolated from CHO-9 cells mutagenized with ethylmethane sulfonate, through clonal selection on 96-well dishes. The isolated mutant cells (LSJ-11) were 3-fold more sensitive than controls in the survival to lithocholic acid and were also sensitive to other bile acids such as deoxycholic acid and cholic acid. As a preliminary characterization, it was found that the mutant cells were also sensitive to cytoskeleton-disturbing agents such as colchicine, colcemide, taxol and cytochalasin B. This is the first observation that a bile acid-sensitive mutant was isolated and was partially characterized.

Morphometric analysis of benign and malignant adrenal pheochromocytomas

At present, there are no reliable histologic features that can predict malignancy in adrenal pheochromocytomas other than the documentation of metastases. With the use of computerized interactive morphometry, our aim was to assess nuclei from tissue sections of confirmed cases of benign and malignant pheochromocytomas to determine whether consistent quantitative differences existed between the two. Eight benign cases with at least a 5-year follow-up and nine malignant cases with documented metastases were evaluated. Size distribution plots of the maximum nuclear cord length and of the nuclear area showed a narrow peak for the malignant cases, whereas benign cases showed a right-shifted curve with a wider peak. We concluded that nuclear morphometric analysis of benign and malignant pheochromocytomas yields two distinctive patterns and may be of utility in the assessment of future cases.

Hypothalamic-pituitary-adrenal axis function in children with attention-deficit hyperactivity disorder

Examined hypothalamic-pituitary-adrenal axis (HPA axis) function in 30 children with attention-deficit hyperactivity disorder (ADHD) by measuring the diurnal variation and response to the dexamethasone suppression test (DST) of saliva cortisol. Normal diurnal saliva cortisol rhythm was found in only 43.3% of the ADHD children. DST showed suppression in 46.7% of the ADHD children. An abnormal diurnal rhythm and nonsuppression to the DST were more frequent in the severely hyperactive group than in the mildly were more frequent in the severely hyperactive group than in the mildly hyperactive group of children with ADHD. These results suggest abnormalities in HPA axis function in some children with ADHD, especially those exhibiting severe hyperactivity.

Identity of D-3-aminoisobutyrate-pyruvate aminotransferase with alanine-glyoxylate aminotransferase 2

D-3-Aminoisobutyrate-pyruvate aminotransferase (EC 2.6.1.40) and alanine-glyoxylate aminotransferase 2 (EC 2.6.1.44) were co-purified from rat liver as a single protein. The ratio of the two activities remained constant after Sephacryl S-200 chromatography and chromatofocussing. The Km value for beta-alanine as a substrate with 1 mM glyloxylate as amino group acceptor was 1.4 mM. The activity was inhibited by (S)-alanine with Ki = 2.2 mM. The Km for (S)-alanine as substrate with 1 mM glyoxylate as amino group was 6 mM. This activity was inhibited competitively by beta-alanine with Ki = 0.7 mM. (R)-3-aminoisobutyric acid, 5-aminolevulinic acid, NG,NG'-dimethyl-(S)-arginine, and (S)-2-aminobutyric acid were active competitively with respect to beta-alanine with Km of 0.12 mM, 2.1 mM, 6.4 mM and 11.3 mM, respectively. Antiserum to rat liver D-3-aminoisobutyrate-pyruvate aminotransferase inhibited alanine-glyoxylate aminotransferase activity in rat liver in the same way as that of D-3-aminoisobutyrate-pyruvate aminotransferase. Alanine-glyoxylate aminotransferase activity and D-3-aminoisobutyrate-pyruvate aminotransferase activities were inactivated competitively with respect to beta-alanine by 5-fluorouracil and 6-azauracil, which are chemotherapeutic reagents used to cancer. These experiments indicate that D-3-aminoisobutyrate-pyruvate aminotransferase is identical with alanine-glyoxylate aminotransferase 2, aminolevulinate aminotransferase, 2-aminobutyrate aminotransferase and dimetylarginine-pyruvate aminotransferase.

Pathological analysis of bone fractures in race horses

Pathomorphological analysis was performed on fractured bones of 470 race horses. The most common fracture site was the limb (98% of cases), and the majority of fractures were intra-articular. Focal osteochondral lesions consisting of osteochondrosis, osteonecrosis and osteosclerosis were observed frequently in fractured and non-fractured bones. In the fractured bones, the lesions frequently appeared in the vicinity of the fractured site. Under the influence of antecedent osteochondrosis from the young stage, osteosclerotic and osteonecrotic lesions may have been induced by immoderate exercise and localized ischemia. These morbid conditions may be important as local predisposing factors for bone fracture because the osteosclerotic and osteonecrotic lesions may contribute to diminished resistance to torsion and shearing forces.

Effect of systemic hypotension on cerebral energy metabolism during chronic cerebral vasospasm in primates

The influence of systemic hypotension on cerebral blood flow (CBF) and energy metabolism during chronic cerebral vasospasm after subarachnoid hemorrhage was studied in 15 monkeys. Changes in the phosphorus spectrum, as demonstrated by in vivo phosphorus-31 (31P) magnetic resonance (MR) spectroscopy, or in regional CBF were measured in the parietal cortex during graded hypotension. Sequential changes in the phosphorus spectrum were observed during moderate hypotension in the animals 7 days after the introduction of an autologous blood clot around the right middle cerebral artery (MCA). Angiograms revealed a reduction in vessel caliber by approximately 50% in the right MCA. The mean CBF in the spasm side decreased in parallel with a decrease in the mean arterial blood pressure (MABP) from 120 to 40 mm Hg, indicating the abolition of autoregulation. There were no significant differences in the mean percentage totals of inorganic phosphate (Pi), phosphocreatine (PCr), adenosine triphosphate (ATP), and pH between the hemispheres at baseline MABP before hypotension. The values of PCr, ATP, and pH decreased significantly (p < 0.05) and Pi increased significantly (p < 0.05) at an MABP of less than 60 mm Hg in the involved hemisphere. The ratio of PCr:Pi decreased in parallel with a decrease in MABP. The ATP showed a stepwise decrease during moderate hypotension (MABP 60 mm Hg) and was reduced significantly 20 minutes after the beginning of hypotension (p < 0.05). The results indicate that, during chronic vasospasm, changes in cerebral energy metabolism are coupled with changes in CBF in the state of impaired autoregulation. There exists a critical level for ischemia below which high-energy phosphorus metabolites become markedly depleted. It is suggested that 31P MR spectroscopy may be useful to evaluate the ischemic vulnerability of brain tissue in order to prevent delayed neurological deficit during cerebral vasospasm.

An abnormal protein C (protein C Yonago) with an amino acid substitution of Gly for Arg-15 caused by a single base mutation of C to G in codon 57 (CGG-->GGG). Deteriorated calcium-dependent conformation of the gamma-carboxyglutamic acid domain relevant to a thrombotic tendency

Protein C Yonago is a dysfunctional protein C characterized by defective anticoagulant activity determined by a coagulation assay and normal amidolytic activity measured on a synthetic substrate S-2366 (Iijima et al., Thromb Res 1991;63:249-257). We have identified a single point mutation of C to G in codon 57 (CGG-->GGG) of the gene for protein C Yonago by genetic analysis utilizing the polymerase chain reaction. The mutation should have resulted in an amino acid substitution of Gly for Arg at position 15 of the light chain of mature protein C. No mutations were found in nucleotides spanning the putative gamma-carboxylase recognition site or gamma-carboxyglutamic acid residues of protein C. Protein C Yonago was non-reactive to monoclonal antibodies JTC-1 and -3 that solely recognized the calcium-dependent conformation of the gamma-carboxyglutamic acid domain. This indicated that the mutation had critically perturbed the highly conserved structure of the gamma-carboxyglutamic acid domain. Thus, the calcium-dependent conformation required for the phospholipids binding to exert the physiological functions of protein C may not have been elicited normally in this abnormal protein C, resulting in defective generation of anticoagulant activities in plasma. Consequently, no anticoagulant activities may have been generated in vivo.

[Human parvovirus B19 infection in patients with hematologic disorders on chemotherapy]

We described two cases having erythroid hypoplasia and pancytopenia, respectively, caused by human parvovirus B19 (PVB19) infection on chemotherapy. The first patient was a seven-year-old boy with Non-Hodgkin's lymphoma. He has obtained complete remission with LSA2L2 protocol, but, immediately after this remission, he suddenly developed high fever, erythema on cheeks and severe anemia without reticulocytes. We concluded that the cause of anemia and other symptoms were due to PVB19 infection because PVB19 DNA in his serum was detected by dot blot hybridization and polymerase chain reaction, although specific antibodies to PVB19 remained absent. He received gamma-globulin intravenously (200mg/kg/day for 5 days). The fever and erythema were improved promptly, but viremia and anemia lasted a few weeks and the specific antibodies to PVB19 were negative for about two months thereafter. The second patient was a nine-year-old boy with common ALL in remission. Pancytopenia suddenly occurred under maintenance therapy. Because IgM to PVB19 was detected in his serum, the patient was diagnosed to have temporary pancytopenia due to PVB19 infection. In conclusion, it is important to confirm specific antibodies and PVB19 DNA in serum when anemia or pancytopenia of unknown cause occurs in immunocompromised patients receiving chemotherapy.

The effects of epidural anesthesia on ventilatory response to hypoxia

STUDY OBJECTIVE

To evaluate the effects of epidural morphine on the ventilatory response to hypoxia in patients having abdominal surgery and to compare the effects of epidural lidocaine.

DESIGN

Open-label, randomized study.

SETTING

Shimane Medical University Hospital, Shimane, Japan.

PATIENTS

Sixteen consenting, unpremedicated ASA physical status I and II patients undergoing abdominal surgery.

INTERVENTIONS

Patients were administered 2 mg of morphine diluted in 10 ml of saline or 10 ml of 2% lidocaine from an epidural catheter that was inserted the day before surgery.

MEASUREMENTS AND MAIN RESULTS

On the day before surgery, ventilatory parameters consisting of minute expiratory volume (VE), tidal volume (VT), respiratory frequency (f), and oxygen saturation by pulse oximeter (SpO2) were measured during resting state and hypoxic challenge. The same measurements were repeated 30 minutes after the epidural injection before surgery. The slope of VE/SpO2 decreased significantly from 1.6 +/- 0.3 to 1.2 +/- 0.2 after epidural morphine, although ventilatory values such as f, VT, VE, and PaCO2 were unchanged. Epidural lidocaine produced no significant changes in ventilatory response.

CONCLUSION

Epidural anesthesia with morphine, but not lidocaine, reduced the ventilatory response to hypoxia indicated by VE/SpO2.

Long-term results of entry closure and aneurysmal wall plication with axillofemoral bypass: a new procedure for repair of DeBakey type 3 dissecting aneurysm

To prevent aneurysm rupture, avoid pseudoaneurysm formation, and preserve intercostal arteries, a new procedure for repair of DeBakey type 3 dissecting aneurysm was developed. Since January 1977, 28 patients have undergone repair of type 3 dissecting aneurysm. Fifteen patients with type 3b underwent this new procedure (group 1) and 13 patients with type 3a dissecting aneurysm underwent segmental graft replacement (group 2). In group 1 a permanent axillofemoral bypass was placed on the right side. Next the intrathoracic false lumen was opened longitudinally, the entry was closed, and the aneurysmal wall was sutured around the true lumen as tightly as possible. The operative mortality rate was 20% in group 1 and 31% in group 2. One of 15 patients in group 1 died of operation-related causes, whereas three patients in group 2 died. There were six late deaths: three in group 1 and three in group 2. Paraplegia occurred in neither group 1 nor group 2. The mean diameter of the plicated descending aorta was 24.0 +/- 2.7 mm 3 months after surgery. No recurrence was detected in group 1. These results suggested that this new surgical technique for repair of type 3 dissection reduces the incidence of paraplegia and pseudoaneurysm formation.

Reversible interactions between plasminogen activators and plasminogen activator inhibitor-1

We have shown that the urokinase (UK) kringle domain contains a high-affinity plasminogen activator inhibitor-1 (PAI-1) binding site, responsible for the 10-fold faster complex formation between UK and PAI-1 than between PAI-1 and low-molecular-weight urokinase (LMWUK). Complex formation between UK and PAI-1, but not between LMWUK and PAI-1, was suppressed 10-fold in the presence of peptide U-107 derived from the UK kringle domain. Peptide U-373 derived from the UK catalytic domain slowed complex formation between UK and PAI-1 and also LMWUK and PAI-1. Inactivation of tissue-type plasminogen activator (tPA) by PAI-1 was slowed 10-fold in the presence of peptides derived from the tPA finger and kringle-2 domains. DFP-inactivated (DIP) UK and both forms of DIP-tPA inhibited PAI-1 binding to U-107 and to U-373 whereas single-chain urokinase-type PA (scuPA) was unable to compete with either peptide for PAI-1 binding. These data suggest that the reversible PAI-1 binding site in the UK A-chain plays a role in the rapid association with PAI-1 as important as those that reside in the tPA A-chain and that reversible PAI-1 binding sites are expressed on the surface of UK upon conversion from scuPA, in contrast to tPA.

[Transjugular intrahepatic portosystemic stent shunt (TIPSS) with use of Rösch-Uchida transjugular liver access set--evaluation by CT and its clinical application]

Appropriateness of the Rösch-Uchida transjugular liver access set designed for TIPSS procedure was confirmed, especially about the catheter angle and effective length of the 20 G puncture needle, by CT analysis on three dimensional vascular anatomy of the liver. Clinically, TIPSS using the set was successfully made for two patients, connecting superior right hepatic vein with right portal vein in one patient and middle hepatic vein with left portal vein in another patient with hypoplastic right portal vein. Prior to TIPSS procedure, verification of vascular anatomy on CT images is the key to success of TIPSS in safe.

[Relationship between health services for maternal and child health and working hours of public health nurses]

Based on the "Maternal and Child Health Service Act", public health centers and municipalities offer health education, health counseling, health examination, and home visits for district children and for their mothers. The relationship between the number of the MCH services offered and the working hours of public health nurses at the public health centers and the municipalities was analyzed. Data were taken by a survey in 1989, which was used for evaluating services provided to the children and their mothers in 1988. Questionnaires were sent to 23 health centers and their districts and 100 responses from 8 wards, 20 cities, 47 towns, and 25 villages were analyzed. When total working hours of the public health nurse for MCH are allocated to the four parts-planning, implementation, evaluation and training-86.7% of working hours are for implementation itself. The correlation coefficient between the total working hours of the public health nurse for MCH and the population, and the number of births per year, were significantly positive. A total of 107 hours were supplied for the infant child health examination per 100 births per year, for which 64% was for implementation itself. In the case of the health examination for three-year-old children, total working hours were 143 hours, for with 79% was for implementation itself. The number of mother-child handbooks issued, the number of health education classes and health counselings conducted, various health examinations performed, and home visits made were correlated significantly with the working hours of the public health nurse.

[Coronet status of digital radiography in chest medicine]

It has been ten years since Computed Radiography (CR) was introduced to evaluate its efficacy on the diagnosis of chest diseases in Japan. Over 600 CR systems are in their daily clinical use. CR images improve the quality of chest X-ray diagnosis with its enhancement parameters, that is, the digital image's contrast and edge enhancement. In daily clinical work, however, some abnormalities on the images, such as infiltrative shadows and fine miliary shadows, have shown CR imaging to have no superiority in visualization compared to conventional X-ray films. The quality of CR images greatly depends on the reconstruction algorithm. The diagnostic system of CR images using CRT monitor and workstations will be warranted in order to make the CR system the optimal and most useful modality in chest medicine. The CR system is potentially applicable in Picture Archiving and Communication System (PACS).

[Gianturco expandable metallic stents in the treatment of tumor thrombus in portal vein--preliminary clinical experience]

Two cases of hepatocellular carcinoma with protal vein invasion (Vp3) were successfully treated by Gianturco expandable metallic stents (GEMS). Each case was treated through the different approach, i.e. the percutaneous transhepatic or ileocolic venous route. GEMS was easily expanded within the protal vein and carcinoma thrombi were pushed against the walls, resulting in increase of portal blood flow. The GEMS might improve the impaired portal blood flow with hepatic failure and esophagogastric varices, in spite of the possibilities of dissemination and ingrowth of carcinoma thrombi.

Decrease in heart mitochondrial creatine kinase activity due to oxygen free radicals

This study was undertaken to examine the effects of oxygen free radicals on mitochondrial creatine kinase activity in rat heart. Xanthine plus xanthine oxidase (superoxide anion radical generating system) reduced mitochondrial creatine kinase activity both in a dose- and a time-dependent manner. Superoxide dismutase showed a protective effect on depression in creatine kinase activity due to xanthine plus xanthine oxidase. Hydrogen peroxide inhibited creatine kinase activity in a dose-dependent manner, this inhibition was protected by the addition of catalase. In order to understand the detailed mechanisms by which oxygen free radicals inhibit mitochondrial creatine kinase activity, the effects of oxygen free radicals on mitochondrial sulfhydryl groups were examined. Mitochondrial sulfhydryl groups contents were decreased by xanthine plus xanthine oxidase or hydrogen peroxide; this depression in sulfhydryl groups contents was prevented by the addition of superoxide dismutase or catalase. N-Ethylmaleimide (sulfhydryl group reagent) expressed inhibitory effects on the creatine kinase activity both in a dose- and a time-dependent manner; dithiothreitol or cysteine (sulfhydryl group reductant) showed protective effects on the creatine kinase activity depression induced by N-ethylmaleimide. Dithiothreitol or cysteine also blocked the depression of mitochondrial creatine kinase activity caused by xanthine plus xanthine oxidase or hydrogen peroxide. These results lead us to conclude that oxygen free radicals may inhibit mitochondrial creatine kinase activity by modifying sulfhydryl groups in the enzyme protein.

[Usefulness and limitations of ECG-gated myocardial single-photon emission computed tomography with 99mTc-methoxy-isobutyl-isonitrile (MIBI) in patients with prior myocardial infarction]

To evaluate the relationship between regional wall motion and 99mTc-methoxy-isobutyl-isonitrile (MIBI) uptake, ECG-gated single-photon emission computed tomography (SPECT) with 99mTc-MIBI was performed in 20 patients with prior myocardial infarction. The left ventricular images at end-diastole (ED) and end-systole (ES) were divided into 39 segments, respectively. Based on circumferential profile analysis, relative uptake (%EDc, %ESc), percent count increase (% delta C), and normalized percent count increase (% delta Cn) were analyzed in each segment and compared with regional wall motion indices assessed by echocardiography and left ventriculography. ECG-gated SPECT with 99mTc-MIBI provided high contrast tomograms of the left ventricular myocardium. %EDc and %ESc showed good correlations with regional wall motion indices. % delta C and % delta Cn, however, showed lower correlations compared with %EDc and %ESc. In conclusion, high-quality left ventricular images were obtained with 99mTc-MIBI ECG-gated SPECT, but quantitative analysis based on only percent count increase (% delta C) have limitations for evaluation of regional wall motion.

Intrapulmonary sublesions detected before surgery in patients with lung cancer

BACKGROUND

The treatment of patients with multiple intrapulmonary lesions remains controversial.

METHODS

Fifty-three patients with lung cancer, in whom preoperative evaluation disclosed intrapulmonary nodules distinct from the main tumor, were analyzed retrospectively to establish the optimal treatment in such cases.

RESULTS

These sublesions proved to be intrapulmonary metastases (PM) in 16 cases (30%), multiple primary lung cancers in 7 cases (13%), and various nonmalignant lesions in the others. The survival of the 53 patients, and of patients with clinical Stage I/II disease in particular, compared favorably with that of all patients with resected lung cancer. Those with multiple sublesions had a poorer prognosis, irrespective of their nature. Although patients with PM as sublesions often had clinically advanced cancer, metastatic foci, per se, did not influence the survival data as calculated by a multivariate analysis.

CONCLUSIONS

The authors conclude that the existence of a solitary intrapulmonary sublesion should not preclude surgical treatment, unless surgery is contraindicated because of other clinical and radiologic findings.

Gene analyses of abnormal fibrinogens with a mutation in the gamma chain

In four abnormal fibrinogens with a point mutation in the gamma chain, all characterized by impaired fibrin polymerization, we identified single base exchanges in the respective mutant gamma chain genes by polymerase chain reaction followed by DNA sequence analysis. These base exchanges accounted for the amino acid substitutions previously reported from our laboratory. They were exchanges of C to T (CGC for gamma Arg-275 to TGC for Cys) in fibrinogen Osaka II, T to G (AAT for gamma Asn-308 to AAG for Lys) in fibrinogen Kyoto I, T to C (ATG for gamma Met-310 to ACG for Thr) in fibrinogen Asahi, and G to T (GAT for gamma Asp-330 to TAT for Tyr) in fibrinogen Kyoto III. These base exchanges were found to reside in exon VIII of the gamma chain gene. Since many abnormal molecules are associated with polymerization defects, unless associated with the impaired release of fibrinopeptides A and/or B, exon VIII of the gamma chain gene may deserve careful study to define the structural alterations.