Natural frequency/damping coefficient relationship of the catheter-manometer system required for high-fidelity measurement of the pulmonary arterial pressure

Using a digital simulation method, we analyzed the relationship between natural frequency (f _n ) and damping coefficient () of the catheter-manometer system required for high-fidelity measurement of the pulmonary arterial pressure. The pulmonary artery pressure waveform was obtained with a catheter-tip transducer and it was fed into a dynamic simulator programmed on a computer. The original waveform and the output of the simulator were compared and judged visually for the fidelity. From this analysis, the combination of f _n and was obtained and was plotted on a f _n – diagram. It showed as an area, which was convex on the left side and open on the right side. The left-convex endpoint was located at a damping coefficient of about 0.7. At a lower heart rate, this area was extended to the lower frequency side, while, at a higher heart rate, this area was limited to the higher frequency side. The f _n – diagram was also constructed theoretically by calculating the relations between natural frequencies and damping coefficients of a second order system with the amplitude and phase error tolerance set at +/–5% respectively.(Kinefuchi Y, Suzuki T, Takiguchi M, et al.: Natural frequency/Damping coefficient relationship of the catheter-manometer system required for high-fidelity measurement of the pulmonary arterial pressure. J Anesth 7: 419--426, 1993)     

The protective effect of thromboxane A2 synthetase inhibitor against ischemic liver injury

To evaluate the role of thromboxane A₂ (TXA₂) in ischemic liver injury, the serum changes in thromboxane B₂ (TXB₂) and 6-keto-prostaglandin F₁ alpha (6-K-PGF₁) following warm ischemia of the total canine liver were examined, and the protective effect of a TXA₂ synthetase inhibitor was assessed. Total liver ischemia was performed for 60 min on two groups of dogs: a control group, in which ischemia alone was performed, and an OKY-046 group, which received a TXA₂ synthetase inhibitor. A temporary active portacaval shunt was used to eliminate the effects of splanchnic venous stasis during clamping of the hepatic pedicle. Postoperative changes in liver function, assessed by the transaminase enzyme levels, and in prostaglandins were recorded and the histologic liver findings of both groups 1 week after ischemia were compared. The levels of 6-K-PGF₁ increased after reperfusion in both groups, while those of TXB₂ increased in the control group but maintained low levels in the OKY-046 group. Liver function was better and histologic changes less marked in the OKY-046 group than in the control group, suggesting the important role of TXA₂ in ischemic liver injury and the usefulness of a TXA₂ synthetase inhibitor for protecting the liver against ischemic injury.     

Programming a predictive rormula for angina and other risk factors in patients with cardiac diseases undergoing noncardiac operations

We programmed a formula which predicts the incidence of either myocardial infarction or cardiac death during the postoperative period. The original formula was proposed by Shah et al, based on their own data and analysis. The program is simple and is written in a language called Quick Basic. The use of this program is also simple. Such a program has improved the use of this analysis substantially. The program has been posted on to a few Computer network services as a free software.(Suwa K, Ogura S: Programming a predictive formula for angina and other risk factors in patients with cardiac diseases undergoing non-cardiac operations. J Anesth 6: 241–242, 1992)     

Report on the Computer Software Contest at 38th Congress of the Japan Society of Anesthesiology

We held a computer software contest at 38th Congress of the JSA, held in March, 1991. The aim is to encourage the members of the Society to write softwares and to help distribute them, especially as Freewares. We received 25 entries for the contest; two-thirds of these are for computers of NEC PC9801 series and a third are for Macintosh. We received donations 3 million yen worth of instruments and goods for prizes plus some cash, which as prizes were distributed to those who made entries for the contest.Most of these programs have been registered as freewares at various computer networks, including our Ether-Net, one of the common computer network SIGBBSs among Japanese anesthesiologists.(Suwa K, Miyasaka K, Tanaka Y, et al.: Report on the computer software contest at 38th congress of the Japan society of anesthesiology. J Anesth 5: 441–444, 1991)Executive Committee of the Computer Software Contest at 38th Congress of the Japan Society of Anesthesiology     

Induction of active melanocytes in mouse skin by carcinogens: a new method for detection of skin carcinogens

Application of potent skin carcinogens, such as 7, 12-dimethylbenz[a]anthracene,3-methylcholanthrene, benzo[a]pyrene and 4-nitroquinoline-1-oxide,induced numerous dihydroxyphenylalanine (dopa)-positive cellsin the interfollicular epidermis of C57BL/6 mice in a dose-and time-dependent fashion. Chrysene, a weak skin carcinogen,and croton oil, a tumor promoter, also induced 3–4 timesmore dopa-positive cells than acetone. Liver carcinogens, suchas 3'-methyl-4-di-methylaminoazobenzene and N-2-acetylaminofluorene,and non-carcinogenic aromatic hydrocarbons, such as anthracene,fluoranthene, fluorene and pyrene, did not induce increase inthese cells. These results indicate that increase in the numberof dopa-positive cells after application of chemicals is wellcorrelated with the abilities of these compounds to induce skincarcino-genesis and suppress sebaceous glands.     

Plasma cell leukemia with lobulated nuclei: One case report

The case of an 80-year-old man with plasma cell leukemia characterized by basophilic cytoplasm, and extensive lobulated nuclei is described. In spite of the peculiar morphologic nuclei, the diagnosis was based on the presence of M protein and Bence Jones protein in the serum and urine, immunophenotypic characteristics, immunoglobulin gene rearrangement, and findings of transmission electron microscopy.     

Stress sensitization induced by stressor and methamphetamine]

Repetitive or acute treatment of methamphetamine (MAP) or amphetamine (AMP) induces sensitization to both subsequent challenge treatment of the drugs, and exposure to emotional and physiological stress. In addition, chronic treatment of AMP enhanced DA utilization/release in striatum. Similarly, repetitive exposure to footshock or tail shock stress induces sensitization of noradrenaline or 3-methoxy-4-hydroxyphenylglycol (MHPG) to subsequent mild stress and to small amounts of AMP or MAP injection. Striatum, nucleus accumbens and prefrontal dopaminergic systems have an important role in the development of this sensitization. Immediate early gene (IEG) expression in the hypothalamus, nucleus accumbens and striatum may be involved in this process. Neurobiological vulnerability to schizophrenia may be induced by the interaction of multiple gene disposition and environmental insult, and schizophrenia onset and/or relapse in response to mild, non-specific stress. Stress-sensitive systems therefore are postulated in the pathophysiology of schizophrenia. In this regard, mesolimbic DA systems may be involved in the pathophysiology of schizophrenia. In contrast to MAP- or AMP- and stress-induced sensitization, haloperidol and clozapine induce IEG expression in the caudate-putamen and amygdala. Collectively, MAP- or AMP-induced sensitization may, in part, share an early functional process of neurobiological mechanisms.     

Quantification of N-acetyl-seryl-aspartyl-lysyl-proline in hemodialysis patients administered angiotensin-converting enzyme inhibitors by stable isotope dilution liquid chromatography-tandem mass spectrometry

We developed a sensitive, selective and accurate method based on liquid chromatography with tandem mass spectrometry (LC-MS/MS) to determine N-terminal thymosin-β peptides of Ac-SDKP and Ac-ADKP in human plasma samples. Quantification of Ac-SDKP and Ac-ADKP was performed using solid phase extraction (SPE) based on C(18), reversed phase LC separation, and stable isotope dilution electrospray ionization-MS/MS in multiple reaction-monitoring (MRM) mode. The Ac-SDKP-(13)C(6), (15)N(2) and Ac-ADKP-d(7) were synthesized for the internal standards. These MRM monitoring ions were m/z 488→129 (quantitative ion)/226 for Ac-SDKP, m/z 496→137 for Ac-SDKP-(13)C(6), (15)N(2), m/z 472→129 (quantitative ion)/226 for Ac-ADKP, and m/z 479→129 for Ac-ADKP-d(7), respectively. Lower limit of quantitation (LLOQ) of Ac-SDKP and Ac-ADKP was 0.1ng/mL in human plasma. Recovery values were ranged from 94.7% to 106.3% for inter- (RSD: 0.6-3.5%) and intra- (RSD: 0.4-4.9%) day assays. Plasma Ac-SDKP levels were significantly higher in hemodialyzed subjects treated with angiotensin-converting enzyme inhibitors of enalapril (27.3±24.6ng/mL, n=10) and trandolapril (12.3±16.9ng/mL, n=18) than healthy (0.4±0.2ng/mL, n=7) and hemodialyzed subjects (0.6±0.2ng/mL, n=34). This analytical method would be useful to measure N-terminal thymosin-β peptides in human plasma for the clinical study.     

Association between maternal gestational diabetes mellitus and high‐sensitivity C‐reactive protein levels in 8‐year‐old children: The Yamanashi Adjunct Study of the Japan Environment and Children’s Study (JECS)

Gestational diabetes mellitus (GDM) is one of the most common pregnancy‐related complications; it is associated with adverse pregnancy outcomes and metabolic disorders in offspring, consistent with the concept of the developmental origins of health and disease. This cohort study of women without diabetes (n = 761), who were part of the Yamanashi Adjunct Study of the Japan Environment and Children’s Study, aimed to explore the associations between maternal GDM and their offspring’s level of high‐sensitivity C‐reactive protein (hsCRP), a biomarker of inflammatory and cardiovascular diseases. We analyzed the associations between GDM and the offspring’s hsCRP levels using a multiple logistic regression model. A mother with GDM significantly increased the risk for high hsCRP level by 4.07‐fold (≥2.0 mg/L) in the child. As such, maternal GDM was significantly associated with increased serum hsCRP levels in 8‐year‐old children.     

Comparison of the clinical courses of the opticospinal and conventional forms of multiple sclerosis in Japan

We evaluated the clinical courses of 216 patients with multiple sclerosis (MS) diagnosed according to the recommended diagnostic criteria of McDonald et al (10). Sixty-five patients clinically displaying selective involvement of the optic nerves and spinal cord were classified as opticospinal MS (OS-MS), while the other 151 showing disseminated involvement of the central nervous system were classified as conventional MS (C-MS). The disease duration did not differ significantly between the two subtypes (11.2 years vs. 11.5 years). In addition to a higher age of onset, female preponderance and higher Kurtzke's expanded disability status scale (EDSS) scores, the OS-MS patients showed a markedly lower frequency of secondary progressive MS than the C-MS patients (4.6% vs. 29.1%, p=0.0001). The EDSS scores of the C-MS patients were significantly correlated with the disease duration, while those of the OS-MS patients were not. Among the C-MS patients, the frequency of secondary progressive MS was significantly more common in patients with a disease duration of more than 10 years than in those with a shorter duration. These results suggest that the irreversible disability in OS-MS is determined by relapses, rather than by chronic progression, whereas C-MS has a similar clinical course to MS in Westerners.