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Biomedical subjects

E Hamada

Publications and source records attributed to E Hamada.

At least 55 records · Page 3Linked to original sources
PubMed1993

A continuous, simple and rapid method for the detection, extraction and identification of residual antibacterial agents in meat.

Most antibacterial agents produced larger inhibition zones and showed lower detectable concentrations on minimal medium (MM) seeded with Bacillus subtilis than on Mueller-Hinton medium. After simple extraction, using a small amount of acetonitrile, from an agar block inside the inhibitory zone produced by each antibacterial agent, identification was carried out by reverse-phase high-performance liquid chromatography (HPLC). It is recommended that for inspection of residues MM is superior as a bioassay medium. The continuous, simple and rapid method described may be useful for routine laboratory testing of residual antimicrobial agents in food.

Anti-Bacterial Agents↗
PubMed1991

Beta-angonists modulate ACh-inhibition of a K current in intestinal smooth muscle cells.

ACh causes a long-lasting inhibition of STOCs via G proteins in intestinal smooth muscle cells. We examined the effects of isoproterenol (Iso) on the ACh-induced inhibition of STOCs in isolated ileal smooth muscle cells using the G omega-seal whole cell clamp technique. In control, ACh (1 microM) completely suppressed STOCs, which did not desensitize over a period lasting 20 minutes. When Iso (10 microM) was added to the bath in the presence of ACh, the ACh-induced inhibition of STOCs was gradually removed. This effect of Iso was prevented by propranolol (10 microM). Application of Db-cAMP (500 microM) mimicked the Iso effects. Intracellulary applied GTP-gamma S (100 microM) gradually suppressed STOCs in the absence of ACh, which could not be removed by either Iso or Db-cAMP. These results suggest that beta-adrenergic stimulation causes a removal of the muscarinic inhibition of STOCs via a cAMP-dependent process.

Acetylcholine↗
PubMed1991

Coenzyme Q10 attenuates cyanide-activation of the ATP-sensitive K+ channel current in single cardiac myocytes of the guinea-pig.

The effect of coenzyme Q10 (CoQ10) on the cyanide (CN-)-induced ATP-sensitive K+ channel current (KATP) was examined in single atrial myocytes, using the patch clamp technique. Superfusion of the cells with a CN-/low glucose bathing solution induced an outward current in the whole-cell clamp condition. Glibenclamide (1 microM) abolished this current, indicating that the current was carried through the KATP channel. After steady-state activation by CN-, pinacidil (a KATP channel opener, 300 microM) failed to further increase the current. In cell-attached patches, CN-, when applied to the bath, induced bursting openings of an 80 pS channel (the KATP channel). In cells preincubated for 30 min in a solution containing CoQ10 (100 micrograms/ml), CN(-)-activation of the KATP channel was markedly attenuated both at the whole cell and at the single channel level. At the steady-state effect of CN- in CoQ10-treated cells, pinacidil (300 microM) activated the current to the maximum level achieved by CN- in the control cells. These results suggest that CoQ10 reduces in the CN(-)-induced KATP current not by affecting the channel itself but by preventing depletion of intracellular ATP caused by CN-.

Adenosine Triphosphate↗
PubMed1991

Multiple-needle insertion method in percutaneous ethanol injection therapy for liver neoplasms.

One of the shortcomings of percutaneous ethanol injection therapy (PEIT) is that many sessions are necessary to accomplish the treatment. In order to reduce the number of treatment sessions, we inserted two or three needles before injection of ethanol was begun. Using the multiple-needle insertion method, we markedly reduced the number of treatment sessions. Histopathologic examination, imaging techniques, and serum alpha-fetoprotein levels showed efficacy of PEIT using the multiple-needle insertion method. No serious complication occurred. Levels of transient pain, fever, and the feeling of intoxication did not seem to be different from those occurring with the conventional method. Multiple-needle insertion method may be valuable as a method for reducing the number of treatment sessions necessary and thus shortening the treatment period.

Carcinoma, Hepatocellular↗
PubMed1991

A case of malignant lymphoma in the liver treated by percutaneous ethanol injection therapy under peritoneoscopic observation.

A 41-year-old woman with non-Hodgkin's lymphoma in the liver was treated with percutaneous ethanol injection therapy. Ethanol injection was performed twice under ultrasonographic guidance for a lesion inside the liver and once under peritoneoscopic observation for lesions on the surface of the liver. CT performed after treatment showed that sizes of the lesions decreased and that the lesions were not enhanced by contrast medium, indicating lack of blood supply and necrosis of the lesion. Ultrasonography performed after treatment did not show any lesions in the liver. There was no sign of recurrence or metastasis.

Adult↗
PubMed1991

Sensation of ear fullness caused by eustachian tube dysfunctions.

One hundred and ninety-four patients with a sensation of ear fullness were examined with the audiometry, tympanometry, and tubotympanoaero-dynamic graphy (TTAG) as a eustachian tube ventilatory test. In 74 cases of 194, the eustachian tube dysfunction was thought to cause an ear fullness sensation and patulous tube was found in 19 patients which is more frequent than expected. Functional unbalance of the both eustachian tubes which results from minimum ventilatory disturbance on the complaining side was also thought to be one of the causes of this symptom. The eustachian tube dysfunctions like stenotic or patulous tube could not be fully diagnosed by the audiometry and tympanometry because most patients with the eustachian tube dysfunctions showed normal middle ear pressure measured by the tympanometry. From our study, it could be concluded that eustachian ventilatory test like TTAG was very available in the patient with an ear fullness feeling which is one of the most common symptoms in the otolaryngological field.

Acoustic Impedance Tests↗
PubMed1990

Heparin uncouples the muscarinic receptors from GK protein in the atrial cell membrane of the guinea-pig heart.

The effects of heparin on activation of the G protein-gated muscarinic K+ channel were examined in atrial cells of guinea-pig heart. The inside-out patch clamp technique was used. The pipette solution contained 1.1 microM acetylcholine (ACh). In the inside-out patches, intracellular GTP activated the muscarinic, K+ channel. When heparin (0.05-5 units/ml) was further added to the intracellular side of the patch membrane, the channel openings were depressed in a concentration-dependent fashion. The effects of heparin were reversible after wash-out. Heparin did not affect GTP-gamma S-induced activation of the K+ channel. Therefore, it is suggested that heparin may uncouple the muscarinic receptors from GK protein in the cardiac atrial cell membrane.

Animals↗
PubMed1990

Trimebutine maleate has inhibitory effects on the voltage-dependent Ca2+ inward current and other membrane currents in intestinal smooth muscle cells.

We examined effects of trimebutine maleate on the membrane currents of the intestinal smooth muscle cells by using the tight-seal whole cell clamp technique. Trimebutine suppressed the Ba2+ inward current through voltage-dependent Ca2+ channels in a dose-dependent manner. The inhibitory effect of trimebutine on the Ba2+ inward current was not use-dependent. It shifted the steady-state inactivation curve to the left along the voltage axis. Trimebutine also had inhibitory effects on the other membrane currents of the cells, such as the voltage-dependent K+ current, the Ca2(+)-activated oscillating K+ current and the acetylcholine-induced inward current. These relatively non-specific inhibitory effects of trimebutine on the membrane currents may explain, at least in part, the dual actions of the drug on the intestinal smooth muscle contractility, i.e. inhibitory as well as excitatory.

Animals↗
PubMed1990

Glibenclamide specifically blocks ATP-sensitive K+ channel current in atrial myocytes of guinea pig heart.

Effects of glibenclamide on the control membrane ionic currents, acetylcholine or adenosine-induced K+ current, and nicorandil-induced K+ current were examined in single atrial myocytes of guinea pig heart. The nystatin-whole cell clamp technique was used. Nicorandil evoked the time-independent K+ current which is probably the current through the ATP-sensitive K+ channel. Glibenclamide inhibited this current in a concentration-dependent fashion, although it had no effect on the other currents. We concluded that glibenclamide specifically inhibits the ATP-sensitive K+ channel current in cardiac myocytes.

Adenosine Triphosphate↗
PubMed1987

[A bronchogenic cyst of the esophageal wall--a case report and differential diagnosis from an esophageal cyst].

A 25-year-old man underwent extirpation of a cystic mass of the esophageal wall. It proved to be an unilocular cyst surrounded by a pseudo-stratified, ciliated columnar epithelium with occasional goblet cells. Outside of the epithelium, a smooth muscle layer was seen and a small foci of seromucous glands were scattered in the wall. Electron microscopic observations of the epithelial layer revealed 5 types of the cells: ciliated columnar cells, mucous cells, brush cells, intermediate cells, and basal cells. Our results suggest that electron microscopic observations are useful for distinguishing the bronchogenic cyst from the esophageal cyst. Nine cases of para-esophageal bronchogenic cysts that have been reported in Japan also are briefly reviewed.

Adult↗
PubMed1986

[Intravascular papillary endothelial hyperplasia of the breast--report of a case with scanning electron microscopic observations].

A 65-year-old woman noticed a left breast mass and underwent excisional biopsy. The excised mass measured 1.7 cm in diameter. Histologically, the tumor-like mass revealed irregular vascular channels with occasional thrombi and many papillary projections of fibrous stalks lined with a layer of flat endothelial cells. A small cavernous hemangioma was present adjacent to the lesion. Scanning electron microscopic observation revealed disorderly oriented thin and thick cords forming branches and meshworks in the lumina. The luminal wall and cords were covered with flat endothelial cells. Light and scanning electron microscopic differences between intravascular papillary endothelial hyperplasia and angiosarcoma are discussed.

Breast↗
PubMed1982

Development and clinical application of a new membrane oxygenator using a microporous polysulfone membrane.

We have developed a new plate-type membrane oxygenator (MO) using a microporous polysulfone membrane. The MO is compact, handy and very easy to set up, and has easy defoaming. The MO is primed with crystalloid; through the cardiotomy reservoir, air exits across the porous membrane and is removed through ports in the membrane oxygenator. Performance and clinical use have shown that the PS oxygenator has a better gas exchange than conventional silicone oxygenators, with appropriate O2/CO2 balance and a capability for controlling oxygen and carbon dioxide separate exchange. The advantage of the MPS membrane is improved blood compatibility, and TABLE 1. BLOOD GAS ANALYSIS DURING PERFUSION Mean +/- SD Range Blood Flow (L/min) 1.56 +/- 0.29 1.04-2.12 Gas Flow (L/min) 1.89 +/- 0.73 0.5-3.0 Gas/Blood Flow Ratio 1.19 +/- 0.38 0.45-1.95 pH venous 7.340 +/- 0.083 7.220-7.443 arterial 7.390 +/- 0.080 7.272-7.507 pCO2 (mm Hg) venous 44.8 +/- 10.8 29.6-65.2 arterial 35.7 +/- 7.1 23.8-51.1 pO2 (mm Hg) venous 46.4 +/- 17.2 26.1-98.8 arterial 276.3 +/- 135.6 66.1-533.4 SO2 (%) venous 71.9 +/- 14.7 35.7-95.6 arterial 98.7 +/- 2.3 91.5-99.9 a larger number of small pores than the MPP membrane. Vapor loss, thought to be typical of microporous membranes, was found to be negligibly small. Use of the PS oxygenator for open heart surgery on 15 pediatric patients proved satisfactory, and in the future the oxygenator may prove useful for prolonged perfusions.

Animals↗