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Biomedical subjects

M Shiga

Publications and source records attributed to M Shiga.

At least 55 records · Page 3Linked to original sources
PubMed1996

Prostaglandin E1 attenuates the hypertensive response to tracheal extubation.

PURPOSE: Tracheal extubation causes hypertension and tachycardia, which may cause imbalance between myocardial oxygen demand and supply in patients at risk of coronary artery disease. We conducted a randomized, controlled study to evaluate the effects of 0.05 or 0.1 microgram.kg-1.min-1 prostaglandin E1 (PGE1) iv on haemodynamic variables occurring during tracheal extubation and emergence from anaesthesia and compared them in patients receiving either lidocaine or saline. METHODS: Eighty ASA physical status 1 patients undergoing elective surgery were enrolled in the current study. Anaesthesia was maintained with sevoflurane 1.0%-2.5% (ET concentration) and nitrous oxide 60% in oxygen. Muscle relaxation was achieved with vecuronium. The patients were randomly assigned to receive one of four treatments (n = 20 each): saline (control), 0.05 microgram.kg-1.min-1 PGE1, 0.1 microgram.kg-1.min-1 PGE1, or 1 mg.kg-1 lidocaine. PGE1 was infused from completion of surgery until five minutes after tracheal extubation. Changes in heart rate (HR) and blood pressure (BP) were measured during and after tracheal extubation. RESULTS: In the control group, the HR, systolic BP, and diastolic BP increased during tracheal extubation. Administration of 0.1 microgram.kg-1.min-1 PGE1 and 1 mg.kg-1 lidocaine attenuated the increases in BP although 0.05 microgram.kg-1.min-1 PGE1 failed to do so. The inhibitory effect of the 0.1 microgram.kg-1.min-1 PGE1 on BP was similar to that of lidocaine 1 mg.kg-1 iv. The increase in HR was attenuated by lidocaine but not by PGE1. CONCLUSION: The intravenous infusion of 0.1 microgram.kg-1.min-1 PGE1 given during emergence from anaesthesia and tracheal extubation is a useful method for attenuating the hypertension associated with noxious stimuli during this period.

Adult↗
PubMed1996

A comparison of lansoprazole, omeprazole, and ranitidine for reducing preoperative gastric secretion in adult patients undergoing elective surgery.

Acid aspiration syndrome of induction of anesthesia is a life-threatening complication whose severity is affected by both pH and volume of the aspirated gastric juice. We compared the effects of two proton pump inhibitors (PPIs), lansoprazole and omeprazole, and an H2 blocker, ranitidine, on gastric secretion in a prospective, randomized, double-blind fashion in 200 adult patients of ASA physical status I undergoing elective surgery. The patients were divided into eight groups (n = 25 each) according to their premedication. The patients received lansoprazole-lansoprazole (Group L-L), lansoprazole-placebo (Group L-P), placebo-lansoprazole (Group P-L), omeprazole-omeprazole (Group O-O), omeprazole-placebo (Group O-P), placebo-omeprazole (Group P-O), placebo-ranitidine (Group P-R), or placebo-placebo (Group P-P), as the first and second medications. The dose of the study drug was 30 mg for lansoprazole, 150 mg for ranitidine, and 80 mg for omeprazole. The first medication was administered orally at 9:00 PM on the night before surgery and the second at 5:30 AM in the morning on the day of the surgery. Each patient fasted overnight and took the drug with 20 mL of water. After tracheal intubation, gastric fluid was aspirated via an orogastric tube and the volume and pH of the aspirate were measured. The pH of the aspirated gastric fluid was higher in Groups P-R, L-L, P-L, O-O, and O-P than in Group P-P (P < 0.05). The volume of the gastric contents was similar in Groups P-0 and P-P, and the other groups had smaller gastric volume than Group P-P (P < 0.05). Gastric fluid from patients in Group P-R was the least acidic (pH 6.1 +/- 1.2) and had the least volume (0.09 +/- 0.06 mL/kg). Group L-L was comparable with Group P-R in both pH and volume, whereas Groups P-L and O-O were similar to Group P-R only in volume. The proportion of patients at risk according to the traditional criteria (pH < 2.5 and volume 0.4 mL/kg) was significantly lower in Groups L-L (0%), P-L (4%), O-O (4%), and P-R (0%) than in Group P-P (48%) (P < 0.05). We concluded that two consecutive doses of lansoprazole or a morning dose of ranitidine seemed to be the most effective preanesthetic medication for reducing gastric acidity and volume.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1996

Mediastinal lymphangiomas in adults: CT findings.

Mediastinal lymphangioma is rare in adults, and there are few reports of their computed tomographic (CT) findings. We present the CT results in three cases of mediastinal lymphangioma. One showed a well-defined, multilocular, water-density mass enveloping mediastinal structures, without their displacement or compression; one presented as a well-defined, homogeneous, water-density mass in the right paratracheal region; and one was associated with hemorrhage into cysts and a significant increase in size over 5 years. CT is useful for diagnosis and evaluation of the extent or contents of mediastinal lymphangiomas.

Adolescent↗
PubMed1996

A combined assay of cell viability and in vitro cytotoxicity with a highly water-soluble tetrazolium salt, neutral red and crystal violet.

Cell viability and in vitro cytotoxicity assay methods were developed using a combination of dyes, 4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate (WST-1), neutral red (NR) and crystal violet (CV), with HeLa cells as a bioindicatior. As WST-1 produces a highly water soluble and non-cytotoxic formazan dye, ti allows each assay to be carried out in one culture dish. The combined cell viability assay using WST-1, NR and CV gave an absorbance that correlated linearly with the number of cells over the range 1000 to 50,000 cells/well. The combined assay was applied to the evaluation of IC50 values for sodium dodecyl sulfate as a model toxicant, which yielded similar values to those obtained with each assay independently.

Cell Survival↗
PubMed1996

[Nitric oxide and the lung].

Many studies on nitric oxide (NO) as a messenger for biosignal transduction have recently been published. Endogenous NO is thought to play a pivotal role in homeostasis of the respiratory system and pulmonary circulation. As exhaled NO levels increase in patients with asthma or bronchiectasia, NO seems to be related to some pathological states in the respiratory organ. NO inhalation has been shown to be effective in attenuating pulmonary hypertension and desaturation in acute respiratory failure. Recent findings concerning NO in the lung were described in this review article.

Acute Disease↗
PubMed1995

Photolysis of a newly synthesized caged glycine activates the glycine receptor of rat CNS neurons.

The functions of 12 different newly synthesized caged glycines were examined on strychnine-sensitive glycine receptors on rat hypothalamic neurons using photochemical and physiological methods. Quantitative analysis of Cl- current induced by photolyzed glycines revealed N-[1-(2-nitrophenyl)ethylcarbonoxyl] glycine (N4-caged glycine) to be the most effectively photolyzed. The current amplitude induced by photolyzed N4-caged glycine was almost the same as that induced by normal glycine. We propose N-[1-(2-nitrophenyl)ethylcarbonoxyl] to be a useful photolabile moiety for new caged neurotransmitters.

Animals↗
PubMed1995

Development of a protein-free medium with iron salts replacing transferrin for a human-human hybridoma.

Many protein-free media have been developed, because protein-free media are usually more economical than serum-free or serum-containing media and facilitate the purification of bioactive materials. We evaluated various iron salts and chelating agents replacing transferrin to develop a protein-free medium for a human-human hybridoma, HB4C5, and found out that ferric citrate was favorable for the production and the productivity of monoclonal antibodies.

Antibodies, Monoclonal↗
PubMed1990

[Studies on antibiotic skin testing].

Commercially available antibiotics for injection are supplied with test ampules. Users are instructed to dissolve them to make 300 micrograms/ml solution for intradermal pretests to avoid allergic reactions. Sometimes this concentration is too low to prevent anaphylactic reactions. In the present study, we tried to find the maximum concentration for the intradermal tests which would have high sensitivity without giving nonspecific, false positive reactions. We investigated intradermal tests with cephalothin (CET) in a patient who suffered from anaphylaxis after drip infusion with CET, although she was judged to be negative to CET by the usual intradermal test prior to the infusion. Her CET skin test was negative at a concentration of 150 micrograms/ml and positive at 300 micrograms/ml 6 weeks after anaphylaxis, but negative at 300 micrograms/ml and positive at 1000 micrograms/ml 4 and 7 years after anaphylaxis. Prick tests were always negative, even with the maximum soluble concentration of CET, 200 mg/ml. Nonspecific reactions to intradermal tests at concentrations as high as 1000 micrograms/ml were examined with 20 kinds of penicillins and cephems in 51 healthy subjects without histories of drug allergies. Very few false positive reactions were observed, except in 5 out of 24 cases with cefotiam. Intradermal tests at 3000 micrograms/ml, however, frequently resulted in nonspecific reactions. We conclude that 1000 micrograms/ml, not 300 micrograms/ml solutions should be used for intradermal tests to prevent allergic reactions to the injection of antibiotics.

Anti-Bacterial Agents↗
PubMed1989

Scavenger receptor of human monocytic leukemia cell line (THP-1) and murine macrophages for nonenzymatically glycosylated proteins.

Long-term incubation of proteins with glucose undergo a series of nonenzymatic reactions to form advanced glycosylation end product (AGE) with fluorescence and brown color. The receptor for AGE-proteins was demonstrated in murine macrophages (Vlassara et al. (1985) Proc. Natl. Acad. Sci. USA 82. 5588). Our recent study with rat macrophages revealed that the receptor also recognized proteins modified with aliphatic aldehydes such as formaldehyde or glycolaldehyde, indicating its close identity to a scavenger receptor for aldehyde-modified proteins (Takata, K. et al. (1988) J. Biol. Chem. 263. 14819). This notion was tested in the present study with human monocytic leukemia cell line (THP-1 cells), human monocyte macrophages and murine peritoneal macrophages. Endocytic uptake of AGE-proteins and aldehyde-modified proteins was inhibited in a cross-competitive fashion. The receptor activities of THP-1 cells for AGE-albumin and aldehyde-modified proteins were induced synchronously by phorbol 12-myristate 13-acetate. Furthermore, upon reduction by NaBH4 of the Schiff base formed between proteins and glucose or aldehydes, no ligand activity was generated. However, once the ligand activity was generated, NaBH4 was no longer effective for the ligand activity. Thus, a structure in common between AGE-proteins and aldehyde-modified proteins may be crucial for recognition by the human macrophage receptor.

Animals↗
PubMed1989

[An investigation of sudden cardiac death in apparently healthy young men by annual health examination].

We have clinically compared the health records of 58 apparently healthy men who succumbed to sudden cardiac death (SCD) against the same number of control subjects (CS) with similar physical and social backgrounds. SCD, for our purpose, was defined as a death that occurred from a non-traumatic cause within one hour after the SCD onset. The clinical examination of our SCD cases consisted of evaluating the findings derived from their health records covering a span of 13 years such as their ECGs, the blood pressure data, chest x-rays, serum chemical analysis, and their obesity indexes. Heart weights were estimated from their ECGs by the quantification of a multivariate analysis. Of the total SCD cases studied, eleven hearts also were examined pathologically. With respect to the physical conditions of the SCD cases and the CS cases, the systolic blood pressure in the SCD cases was found to be higher, whereas no significant variances in the diastolic values were found, and both the systolic and diastolic values were within normal ranges in the two groups. A greater number of hearts weighing more than 420 g were found in the SCD group. Similarly the frequency of premature contraction and the serum cholesterol level was higher. No further appreciable differences, however, were found. Myocardial cell hypertrophy, degeneration, and interstitial edema were observed in all eleven hearts. Our data have revealed that the greater the heart weight, the greater the risk of succumbing to SCD. The risk becomes more evident if the systolic and cholesterol levels are also found to be high.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[Asthma patients requiring unusually high doses of theophylline].

We often see severe asthma attacks occur in patients taking high doses of theophylline and disappear soon after intravenous injection of aminophylline. Theophylline concentration in the serum was investigated in those cases. Twenty five asthmatic patients, 14 males and 11 females, 16-17 years of age, visited our out-patient clinic 41 times in total over a period of 9 months suffering from dyspneic attacks of such severity that they had difficulty in speaking and walking although they had taken at least 200 mg theophylline within 6 hours and 400 mg within 12 hours. All cases were treated with iv infusion of 2.8-14 ml of 2.5% aminophylline for 5-15 minutes until the dyspneic symptoms disappeared. Theophylline levels in the serum (micrograms/ml) before the treatment were 2.0 in 1 case, 6.0-9.8 in 8, 10-20 in 23, and over 20 in 9 cases. Levels after the treatment were 5.8 in 1 case, 10-20 in 15, and over 20 in 25 cases. In one patient, a 27-year-old female, 300-400 mg of theophylline, aminophylline, or choline theophyllinate tablets could increase theophylline concentration in the serum only 4.8 micrograms/ml or less, while her theophylline clearance was normal. The present study revealed that there are asthmatic patients requiring unusually high doses of theophylline, partly because some of them have problems in absorption of theophylline, and partly because many of them need higher levels of blood theophylline than those usually thought of as standard therapeutic concentrations.

Adolescent↗