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Biomedical subjects

J Ishida

Publications and source records attributed to J Ishida.

At least 37 records · Page 2Linked to original sources
PubMed1999

Treatment of the nasal hump with preservation of the cartilaginous framework.

Classically, nasal hump reduction is based on the partial resection of the cartilages and bones of the nose, as it was described by Joseph almost a century ago. The cartilaginous portion of the hump consists of a single unity formed by the two upper lateral cartilages and the septal cartilage. During hump reduction in the classic rhinoplasty, this structure is slashed in three pieces, which is the main cause of irregularities, shadows, and pinchings over the long-term results. Late follow-ups of the classical hump removal often show an inverted V-shaped shadow on the dorsum secondary to the destruction of the osseous-cartilaginous transition. The angle and relation between the septal and upper lateral cartilages are reduced, which may compromise the functional aspect. The destruction of the unique anatomy of the cartilaginous hump is one of the main causes of this functional and aesthetic sequela. Here, we present a technique that preserves the cartilaginous framework of the nasal hump by lowering it through the resection of a strip of septum, avoiding the problems described above.

Cartilage↗
PubMed1999

[Angiotensin II and apoptosis].

Angiotensin II (AII), the effector octapeptide of the renin-angiotensin system, exerts a multitude of actions, including vascular contraction, aldosterone secretion, catecholamine release, glycogenolysis, and decreased renal filtration. These diverse actions are mediated through AII receptor subtypes present in a variety of target tissues. Molecular cloning studies have identified two major types of mammalian AII receptors, designated AT1 and AT2, which are classified as a typical family of seven transmembrane guanyl nucleotide-binding protein (G-protein) coupled receptors from hydropathy analyses. Mainly, if not all, of the actions of AII are mediated by AT1 that has been well characterized. Recently, AT2 is found to exert growth inhibitory and proapoptotic effects, but its physiological role is still unclear. The molecular mechanism and the physiological importance of signaling pathways via these receptors remain to be elucidated.

Angiotensin II↗
PubMed1998

Rescue of angiotensinogen-knockout mice.

Angiotensinogen, the precursor of angiotensins I and II, is a critical component of the renin-angiotensin system that plays an important role in regulating blood pressure and electrolyte homeostasis. Genetically altered mice lacking angiotensinogen (Agt-KO) showed an expected phenotype, such as marked hypotension, but unexpected ones including abnormal kidney morphology, reduced survival rates of newborns, and impaired blood-brain barrier function after cold injury. To examine whether disruption of the angiotensinogen gene is responsible for the observed phenotypes, we generated a line of mice heterozygous for the mouse angiotensinogen gene under the control of a mouse metallothionein-I promoter (MT-Agt) and crossmated transgenic mice with Agt-KO mice. The resulting mice (MT-Agt(+/-)/Agt(-/-):MT-Agt/KO) produced the plasma level of angiotensin I comparable to that of wild-type mice, and the mutant phenotypes were rescued. These results indicated that the resultant phenotypes due to the genetic deficiency of mouse angiotensinogen can be corrected by restoring angiotensinogen and angiotensin I in the circulation.

Angiotensin I↗
PubMed1998

Primary tumours of the greater omentum.

Primary tumours of the greater omentum are very rare. Ultrasound allows the detection and characterization of such lesions, but determination of their precise anatomical location is usually difficult by US. Computed tomography determines the omental origin of the tumour. Thus, when US reveals an abdominal tumour of unknown origin, the possibility of an omental tumour, although rare, must be kept in mind and CT should be performed.

Diagnostic Imaging↗
PubMed1998

Anterior abdominal wall pathologies detected by high-frequency annular array.

AIM AND METHODS: In 1850 patients, high-frequency (HF: 7.5-10 MHz) annular array US examination was performed to evaluate the value of HF annular US in the detection of pathologies of the anterior abdominal wall. RESULTS: HF annular US revealed pathological lesions (metastasis, benign tumor, lymphoma, hematoma, fistula, hernia, abscess) in 37 patients. The lesions were detected by conventional medium-frequency (3.5-3.75 MHz) US in only 8 of 37 cases (21.6%). HF annular US added information that altered clinical management in 19 cases (51.4%), predominantly in cases with tumors and fistulas. CONCLUSION: The addition of HF annular US to a conventional US examination increases the detectability of small, but clinically important pathologies in the anterior abdominal wall.

Abdominal Muscles↗
PubMed1998

Simultaneous determination of urinary catecholamines and 5-hydroxyindoleamines by high-performance liquid chromatography with fluorescence detection.

A simple, selective and sensitive high-performance liquid chromatographic method with fluorescence detection is described for the simultaneous determination of catecholamines and 5-hydroxyindoleamines. The method is based on the derivatization of the amines with benzylamine in the presence of potassium hexacyanoferrate(III) under mild conditions. The resulting fluorescent derivatives are separated on a reversed-phase column, Cosmosil 5C18, using a mixture of acetonitrile and 10 mmol l-1 acetate buffer (pH 6.0) (35 + 65 v/v) as mobile phase, and are detected spectrofluorimetrically at 480 nm with excitation at 345 nm. The detection limits (signal-to-noise ratio = 3) for the amines are 2.8-236.0 fmol for an injection volume of 50 microliters. The method was successfully applied to the determination of 5-hydroxyindol-3-ylacetic acid, serotonin, norepinephrine and epinephrine in human urine. The method is simple and does not require clean-up of urine samples.

Benzylamines↗
PubMed1998

Abdominal wall closure after selective aponeurotic incision and undermining.

The tension required to pull the anterior and the posterior rectus sheaths toward the midline was studied in 20 fresh cadavers at two levels: 3 cm above and 2 cm below the umbilicus. The quotient of the force used to mobilize the aponeurotic site to the midline and its resulting displacement was called the traction index. These indices were compared in three situations: (1) prior to any aponeurotic undermining, (2) after the incision of the anterior rectus sheath and the undermining of the rectus muscle from its posterior sheath, and (3) after additionally releasing and undermining the external oblique muscle. A significant decrease in aponeurotic resistance was observed after each dissection. The anterior sheath showed higher resistance to traction compared with the posterior sheath on both levels. No statistical difference was noted in the comparison of the values of the aponeurosis above and below the umbilicus. These results suggest that these procedures are effective in assisting in the closure of abdominal wall defects because these maneuvers decrease substantially the tension required for advancement of the aponeurotic edges.

Abdominal Muscles↗
PubMed1997

3,4-Dimethoxybenzylamine as a sensitive pre-column fluorescence derivatization reagent for the determination of serotonin in human platelet-poor plasma.

3,4-Dimethoxybenzylamine is shown to be a highly sensitive pre-column fluorescence derivatization reagent for the determination of serotonin in plasma by high-performance liquid chromatography. The reagent reacts selectively with 5-hydroxyindoles including serotonin in slightly alkaline media in the presence of potassium hexacyanoferrate(III) to give highly fluorescent derivatives. The derivatives of six standard 5-hydroxyindoles (5-hydroxytryptophan, 5-hydroxyindole-3-acetic acid, serotonin, 5-hydroxyindole-3-acetamide, N-acetyl-5-hydroxytryptamine and 5-hydroxytryptophol) are separated within 18 min by isocratic elution using acetonitrile-10 mM phosphate buffer (pH 6.0)-50 mM 1-hexanesulfonic acid on a Wakosil II 5C18RS reversed-phase column. The detection limits (signal-to-noise ratio=3) for the indoles were 1.0-5.7 fmol in a 100-microl injection volume. The method was applied to the measurement of serotonin in human platelet-poor plasma.

Benzylamines↗
PubMed1997

Isolated splenic metastases.

We analyzed the primary tumors, sonographic findings, clinical manifestations, and prognosis in five cases of isolated splenic metastases to determine in what situations these rare metastases should be suspected. The metastases were detected by ultrasonography in all five patients, and the primary tumors were colonic cancer in four patients and renal cancer in one patient. Splenectomy was performed and the postoperative course was uneventful in all patients. We conclude that preoperative and follow-up examinations must be performed with special attention given to the spleen in colonic or renal cancer patients.

Adult↗
PubMed1996

Hypertension induced in pregnant mice by placental renin and maternal angiotensinogen.

Maternal hypertension is a common complication of pregnancy and its pathophysiology is poorly understood. This phenomenon was studied in an animal model by mating transgenic mice expressing components of the human renin-angiotensin system. When transgenic females expressing angiotensinogen were mated with transgenic males expressing renin, the pregnant females displayed a transient elevation of blood pressure in late pregnancy, due to secretion of placental human renin into the maternal circulation. Blood pressure returned to normal levels after delivery of the pups. Histopathologic examination revealed uniform enlargement of glomeruli associated with an increase in urinary protein excretion, myocardial hypertrophy, and necrosis and edema in the placenta. These mice may provide molecular insights into pregnancy-associated hypertension in humans.

Angiotensin II↗
PubMed1996

High-performance liquid chromatographic determination of human serum albumin in plasma and urine by post-column fluorescence enhancement detection using 8-anilino-1-naphthalenesulfonic acid.

A method for the quantitative determination of human serum albumin in plasma and urine by post-column high-performance liquid chromatography with fluorescence detection is presented. Human serum albumin in plasma and urine is separated by gel-permeation column chromatography, which is followed by fluorescence detection. The detection uses the fluorescence enhancement observed when 8-anilino-1-naphthalenesulfonic acid binds to human serum albumin. The method is rapid to perform and is highly sensitive (detection limit is 2.5 ng/injection volume at a signal-to-noise ratio of three.

Adult↗
PubMed1996

Assay for tryptophan hydroxylase activity in rat brain by high-performance liquid chromatography with fluorescence detection.

A highly sensitive and selective liquid chromatographic (HPLC) method with post-column fluorescence detection has been developed for the determination of tryptophan 5-monooxygenase activity in rat brain tissue homogenate. 5-Hydroxytryptophan, formed enzymatically from tryptophan (incubation time, 20 min), is extracted with perchloric acid and determined by HPLC. Detection is performed fluorometrically after post-column derivatization by a reaction with benzylamine in the presence of potassium hexacyanoferrate (III). The lower limit of detection for 5-hydroxytryptophan formed enzymatically is 100 fmol at a signal-to-noise ratio of three.

5-Hydroxytryptophan↗
PubMed1995

Determination of maprotiline in plasma by high-performance liquid chromatography with chemiluminescence detection.

A simple and sensitive high-performance liquid chromatographic method is described for the determination of maprotiline, an antidepressant, in plasma. After a single-step extraction from plasma (100 microliters) with n-hexaneisoamylalcohol (19:1, v/v), the drug and desipramine (internal standard) are converted into their chemiluminescent derivatives by reaction with 6-isothiocyanatobenzo[g]phthalazine-1,4(2H,3H)-dione, a new chemiluminescence derivatization reagent for amines. The derivatives are separated within 60 min on a reversed-phase column, TSKgel ODS-80, using isocratic elution with acetonitrile-100 mM acetate buffer (pH 3.2), and produced chemiluminescence by reaction with hydrogen peroxide in the presence of potassium hexacyanoferrate(III) in alkaline medium. The detection limit for maprotiline added to plasma is 0.36 pmol (0.1 ng)/ml plasma (1.5 fmol on column), at a signal-to-noise ratio of 3.

Antidepressive Agents, Second-Generation↗
PubMed1995

Development of a novel luminol-related compound, 3-propyl-7,8-dihydropyridazino-[4,5-g]quinoxaline-2,6,9(1H)- trione, and its application to hydrogen peroxide and serum glucose assays.

Manual and flow injection methods with chemiluminescence detection were developed for the determination of hydrogen peroxide (H2O2) using a novel luminol-related compound, 3-propyl-7,8-dihydropyridazino[4,5-g]quinoxaline-2,6,9(1H)-trione (PDIQ), having a higher efficiency than luminol. The methods are based on the chemiluminescence produced by the reaction of H2O2 with PDIQ in the presence of microperoxidase in alkaline media. Detection limits for manual and flow injection methods are 13 pmol per 100 microliter of test solution and 1.3 pmol per 100 microliter injection volume, respectively, at a ratio of chemiluminescence intensities (or peak heights) of test to blank of 2. The manual method was applied to the determination of glucose in human serum. The method correlated well with the conventional spectrophotometric method (4 = 0.998).

Blood Glucose↗
PubMed1995

A study of cysts in the oral region. Cysts of the jaw.

Clinical cases of cysts of the jaw treated in the Department of Oral Surgery of our university during the 10 y between 1980 and 1989 were studied clinically. Patients with radicular cyst, dentigerous cyst, odontogenic keratocyst and postoperative maxillary cyst, which were found at relatively high frequencies, were further analyzed with regard to age, sex and anatomical distribution. A diagnosis of cyst was established in 1,444 patients during the above period, and 1,234 (85.5%) of them had cysts of the jaw. According to a pathological classification by Ishikawa's method, these patients included 509 (41.2%) with radicular cyst, 259 (27.0%) with dentigerous cyst, 95 (7.7%) with odontogenic keratocyst and 267 (21.6%) with postoperative maxillary cyst. The pattern of age distribution in cases of radicular cyst, odontogenic keratocyst and postoperative maxillary cyst was similar to that found in previous studies. Among patients with dentigerous cyst, those aged under 20 y accounted for about 60%. Radicular cyst occurred most frequently in the maxillary lateral incisors, dentigerous cyst in the mandibular wisdom teeth, and odontogenic keratocyst in the region between the mandibular molar and the ramus of the mandible.

Adolescent↗
PubMed1995

[Reduction mammoplasty with shortened scars: surgical technique].

Reduction mammaplasty is nowadays one of the most frequently performed plastic surgeries. The main purpose is the reduction of the volume of breasts, but the resulting scars can jeopardize the result of the operation. The Division of Plastic Surgery follows the modern tendency of reducing the length of the incisions and thus the resulting scars. A technique that incorporates this principle was developed with good results. The technique is simple enough to be used in a training program.

Cicatrix↗