Biomedical subjects

Y Nishikawa

Publications and source records attributed to Y Nishikawa.

At least 199 records · Page 11Linked to original sources

PubMed1992

[A case of renal pelvic carcinoma in situ].

A 72-year-old female visited our hospital with the complaint of macroscopic hematuria on Jan. 29, 1990. Cystoscopic examination revealed hematuria flowing out from the left ureteral orifice. A 1 cm mass was found in the left upper calyx by retrograde pyelography (RP). Urine cytology obtained by RP was class IIIb. Later, the mass was found in the left middle calyx by CT. Repeated RP revealed no mass and the wall of the left upper calyx was irregular. Washing cytology from the left renal pelvis was class V. Left total nephroureterectomy was performed on Feb. 2, 1990. Macroscopically, no tumor mass was apparent. Microscopically, transitional cell carcinoma in situ was widely spread from the left renal pelvis to the middle ureter. The preoperative upper calyceal mass was thought to have been a blood clot. At twelve months after the operation, there has been no evidence of tumor recurrence.

Aged↗

PubMed1992

[A case of myocardial infarction in a young man with systemic lupus erythematosus].

Apparently the incidence of coronary artery disease in systemic lupus erythematosus (SLE) has been increasing. However, most of the cases had been treated with corticosteroids, and had atherosclerotic lesions in the coronary arterial tree. A 21-year-old man with latent and untreated SLE had an attack of acute myocardial infarction. Coronary arteriography showed eccentric stenotic lesion at the proximal segment of the right coronary artery. One week later, in the 2nd coronary arteriography, this stenotic lesion was not able to be recognized. We supposed that the coronary artery occlusion was due to thrombus formation, and was not related to atherosclerosis, arteritis and embolus. He had no coronary risk factors. Laboratory data showed lymphocytopenia, proteinuria, positive antinuclear antibody, and positive LE cell, and the case was diagnosed as SLE. Subsequent investigations showed the presence of antibodies to cardiolipin. It was suggested that anticardiolipin antibody and other thrombogenic factors were the causes of the coronary occlusive thrombosis in this patient with SLE.

Adult↗

PubMed1992

[Bilateral ureteral obstruction secondary to aneurysm of abdominal aorta: a case report].

A 66-year-old man with the chief complaint of oliguria had been referred to our hospital under the diagnosis of bilateral hydronephrosis and abdominal aortic aneurysm by his family doctor. CT scan and digital subtraction angiography demonstrated an abdominal aortic aneurysm continuing to bilateral internal iliac arteries. The degree of right hydronephrosis was less advanced compared to the left side. Right percutaneous nephrostomy was performed because the retrograde stenting was unsuccessful. After the renal function improved, an operation for the aneurysm was undertaken in the surgical department. Although bilateral ureterolysis was possible, the resection of the aneurysm could not be done. After clamping the nephrostomy catheter, drainage of urine into the ureter was not seen one month after the operation. A double-J ureteral stent was inserted by the antegrade approach and the nephrostomy tube was removed. By exchanging the stent every 3 months, the renal function has been stable and the size of the aneurysm unchanged during the 25 months after the surgery.

Aged↗

PubMed1992

Nitrotriazoles bearing sulfur-substituted side chains: preparation and characterization as hypoxic cell radiosensitizers.

A series of 3-nitro-1,2,4-triazole (NTA) derivatives with -(CH2)mC(= Y)NH(CH2)nZCH3(Y, Z = O or S; m = 1 or 2; n = 2 or 3) group in the side chain at the N-1 position of NTA and their fluorinated analogs were synthesized. Their physicochemical properties and radiosensitizing activities in vitro and in vivo were investigated with respect, particularly, to the effects of sulfur substitution on the side chain of triazoles. The sulfur substitution of the oxygen atom in the side chain of NTA derivatives increased the partition coefficient (P value), but had little effect on the one-electron reduction potential. The derivatives bearing a thioether group in the side chain were more effective in vitro on hypoxic EMT6/KU cells, but were less effective in vivo on SCCVII tumor than their oxygen analogs. The thioamide compounds showed almost the same or slightly higher sensitizing activities in vitro compared with their oxygen analogs.

Animals↗

PubMed1992

[Clinical assessment of patients with microscopic hematuria pointed out by mass screening examination].

We clinically examined 445 patients with positive urine occult blood test found by mass screening examination. Among them, 41 cases had the history of macroscopic hematuria. Urological abnormalities were observed in 169 (41.8%) of the patients with microscopic hematuria, and in 22 (53.7%) of those with a history of macroscopic hematuria. Genitourinary neoplasms were found less frequently in the patients with microscopic hematuria (1.2%) than in those with macroscopic hematuria (22%). We couldn't find a correlation between the degree of hematuria and the severity of the underlying diseases. Hematuria is often thought to appear intermittently, and urinalyses of the patients with so-called significant disease may not be found at the first visit.

Adult↗

PubMed1991

Purification and cDNA cloning of Xenopus laevis skin peptidylhydroxyglycine N-C lyase, catalyzing the second reaction of C-terminal alpha-amidation.

The alpha-amidation of glycine-extended peptides is a two-step reaction catalyzed by peptidylglycine alpha-hydroxylating monooxygenase (PHM) and peptidylhydroxyglycine N-C lyase (PHL). PHL was purified to homogeneity from Xenopus laevis skin and its partial amino acid sequence (including the N-terminal 35 residues) was determined. It was found that the cDNA codes for a 935-residue precursor protein (AE-III protein), containing the PHM and PHL sequences at its N terminus and C terminus, respectively. The PHM sequence in AE-III protein is completely identical to that deduced from the nucleotide sequence of X. laevis AE-I cDNA, which encodes only PHM, except that the AE-I protein has an extra 10 residues at its C terminus. It is suggested that AE-I and AE-III mRNA are encoded by the same gene and produced by alternative splicing.

Amides↗

PubMed1991

Effects of nocturnal hyperprolactinemia on ovarian luteal function and galactorrhea.

To determine the effects of nocturnal hyperprolactinemia on luteal function and galactorrhea we studied six diurnal normoprolactinemic women with regular menstrual cycles. The diurnal serum levels of prolactin (PRL), luteinizing hormone (LH) and progesterone (Prog) and the nocturnal PRL levels at 1 h intervals were determined throughout the first menstrual cycle. Four of the women were nocturnally normoprolactinemic and two showed nocturnal hyperprolactinemia and low luteal progesterone values. In the second menstrual cycle, they were given metoclopramide (10 mg) at midnight before sleep every day, and their serum levels of PRL, LH and Prog were determined by the same protocol as in the first cycle. During treatment with metoclopramide, all the women showed nocturnal hyperprolactinemia, but their diurnal PRL levels remained within the normal range. Low luteal Prog values were observed in all of them and the peak LH levels decreased in all four nocturnally normoprolactinemic women. They had galactorrhea but neither of the nocturnally hyperprolactinemic women had galactorrhea. These results suggest that nocturnal hyperprolactinemia is a cause of luteal insufficiency and galactorrhea.

Adult↗

PubMed1991

An FM3A mutant, G258, with a mutation that affects both cell growth and oligosaccharide-lipid synthesis.

I have previously isolated a temperature-sensitive FM3A mutant (G258) defective in asparagine-linked glycosylation. G258 shows not only the temperature sensitivity for cell growth, but also temperature sensitivity for synthesis of oligosaccharide-lipid (Nishikawa, Y. (1984) J. Cell. Physiol. 119, 260-266). In the present study, I isolated revertants for cell growth from G258 cells. All three growth revertants also showed reversion on the synthesis of oligosaccharide-lipid. These results imply that the temperature sensitivity for oligosaccharide-lipid synthesis of G258 couples with the temperature sensitivity for cell growth of the mutant. A possible mechanism of the coupling between impaired oligosaccharide-lipid synthesis and growth arrest of G258 cells at 39 degrees C is discussed.

Animals↗

PubMed1991

Molecular cloning and expression of cDNA encoding the enzyme that controls conversion of high-mannose to hybrid and complex N-glycans: UDP-N-acetylglucosamine: alpha-3-D-mannoside beta-1,2-N-acetylglucosaminyltransferase I.

UDP-GlcNAc:alpha-3-D-mannoside beta-1,2-N-acetylglucosaminyltransferase I (GnT I; EC 2.4.1.101) catalyzes an essential first step in the conversion of high-mannose N-glycans to hybrid and complex N-glycans. Cloning of the gene encoding this enzyme was carried out by mixed oligonucleotide-primed polymerase chain reaction amplification of rabbit liver single-stranded cDNA using sense and antisense 20- to 24-base-pair (bp) primers. A rabbit liver library in phage lambda gt10 yielded a 2.5-kilobase (kb) cDNA with a 447-amino acid coding sequence. None of the nine asparagine residues were in an Asn-Xaa-(Ser or Thr) sequence, indicating that the protein is not N-glycosylated. There is no sequence homology to other previously cloned glycosyltransferases, but GnT I appears to have a domain structure typical of these enzymes--i.e., a short amino-terminal domain, a transmembrane domain, a "neck" region, and a large carboxyl-terminal catalytic domain. RNA was transcribed off the 2.5-kb cDNA, and in vitro translation with rabbit reticulocyte lysate yielded a 52-kDa protein with GnT I activity.

Amino Acid Sequence↗

PubMed1991

The effect of superoxide dismutase and catalase on myocardial reperfusion injury in the isolated rat heart.

This study was designed to evaluate the efficacy of superoxide dismutase (SOD) and catalase on ischemic and reperfusion injury in the isolated working rat heart. The temperature and duration of ischemia varied under three conditions: 1) at 37 degrees C for 35 minutes, 2) at 28 degrees C for 120 minutes and 3) at 20 degrees C for 120 minutes. SOD (100 mg/L) and catalase 10 mg/L) were either added to St. Thomas' Hospital cardioplegic solution during ischemia (CP group) or to the reperfusion solution for 10 minutes after reflow (RS group). They were compared with a control group which received no free radical scavengers. The postischemic recovery ratio of cardiac functions were markedly superior to the values of the control group with a significant difference being noted in the CP and RS groups under ischemia at 37 degrees C and 28 degrees C. In the series done at 20 degrees C, a significant improvement was seen in the RS group, and the CP group also showed better functional recovery rates compared with the control group, although the differences were not statistically significant. Thus, SOD and catalase added to the cardioplegic solution or reperfusion fluid demonstrated an excellent protective effect on the myocardium against ischemic or reperfusion injury in both hypothermic ischemia and normothermia.

Animals↗

PubMed1991

Trigeminal nociceptive neurons in the subnucleus reticularis ventralis. I. Response properties and afferent connections.

Trigeminal nociceptive neurons within the subnucleus reticularis ventralis medullae oblongatae (SRV), which lies ventral to the trigeminal subnucleus caudalis and subnucleus reticularis dorsalis medullae oblongatae, were studied in urethane/chloralose-anesthetized cats and monkeys. These neurons were called 'SRV neurons'. They were almost regularly excited by pressure to the ipsilateral cornea or to both corneas at a strength well above the human corneal pain threshold. Most of them were activated by noxious mechanical stimulation of the pinna, face and/or tongue. A significant fraction of SRV units was responsive to tapping of the ipsilateral dorsum of the nose and/or electrical stimulation of tooth pulp afferents. Evidence was obtained that responses to tapping of the dorsum of the nose were due to mechanical distortion of the nasal mucosa. Intracellular injection of HRP into SRV neurons demonstrated that injected neurons were large neurons characteristic of the SRV. Trigeminal tractotomy just rostral to the obex did not eliminate responses of SRV units to trigeminal inputs. Neurons relaying trigeminal inputs to SRV neurons were electrophysiologically identified in the nucleus reticularis parvocellularis which is ventromedially adjacent to the subnuclei oralis and interpolaris of the trigeminal spinal tract nucleus. These findings were supported by HRP injection into the SRV. Units having receptive fields similar to those of SRV neurons were found in lamina VII of the first cervical cord, suggesting that SRV neurons may be trigeminal lamina VII neurons.

Afferent Pathways↗

PubMed1991

Trigeminal nociceptive neurons in the subnucleus reticularis ventralis. II. Ascending projection.

Ascending projection of trigeminal nociceptive neurons in the subnucleus reticularis ventralis (SRV) was studied in urethane/chloralose-anesthetized cats. Thalamic neurons having complex trigeminal receptive fields similar to those of SRV neurons were found in the intralaminar nuclei, i.e. nuclei centralis lateralis, centralis medialis and parafascicularis. About half of the SRV units tested were antidromically activated by electrical stimulation of the nucleus centralis lateralis. It was also found that a significant proportion of SRV units was antidromically activated by electrical stimulation of the mesencephalic reticular formation (MRF), and retrogradely labelled neurons were found in the SRV after HRP injection into the MRF. These findings suggest that SRV neurons relay trigeminal nociceptive inputs directly or indirectly via the MRF to the intralaminar nuclei.

Afferent Pathways↗

PubMed1991

Mannose-resistant adhesion of motile Aeromonas to INT407 cells and the differences among isolates from humans, food and water.

Aeromonas has been recognized as an important enteropathogen, but factors related to its virulence have not been clarified. For most enteric pathogens, attachment is a prerequisite for infection and for the effective delivery of toxins to the intestinal epithelial cells. We examined a total of 273 strains isolated from stool, food and environmental specimens by an assay for mannose-resistant adhesion to INT407 cells in vitro. Seventeen of the 102 faecal isolates were adhesive strains with more than 10 bacteria adhering per cell, while only 2 of the 118 isolates from foods and river water adhered to the cells (P less than 0.001). It is possible that the adhesion might serve as a marker for discrimination between the pathogenic and nonpathogenic isolates. The 8 highly adhesive strains with more than 20 adhering organisms per cell were scrutinized for the mechanism of adhesion. No correlation was apparent between the adhesion to INT407 cells and hydrophobicity. It was noted that fucose inhibited the adhesion of four strains as well as haemagglutination by them. Electronmicroscopic studies showed the presence of flexible and curvilinear fimbriae in only 2 of the 8 highly adhesive strains.

Aeromonas↗

PubMed1991

Marked reduction in CSF lactate and pyruvate levels after CoQ therapy in a patient with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS).

Many CoQ trials for mitochondrial encephalomyopathy are reported, however, the action of CoQ in the central nervous system is unknown. We administered CoQ to a patient with MELAS, and decreasing CSF lactate and pyruvate levels were revealed. This reduction in CSF lactate and pyruvate may be evidence that CoQ acts directly on the CNS. There have been no other descriptions of evidence of CoQ effective action in the central nervous system, a finding unique to this report.

Acidosis, Lactic↗

PubMed1991

A case of malignant lymphoma simulating acute myocardial infarction.

A patient with malignant lymphoma suddenly collapsed, and ST segment elevation with complete atrioventricular block was observed on his electrocardiogram during an episode resembling acute myocardial infarction. Cardiac cineangiography revealed posterobasal asynergy of the left ventricle with no significant obstruction in the coronary arterial tree. Autopsy revealed diffuse invasion of the myocardium by lymphoma cells. Left ventricular wall motion was preserved even in the area of massive invasion; there was no true necrosis. Myocardial biopsy may be indicated in patients in whom there is a discrepancy between coronary pathoanatomy and wall motion abnormalities.

Diagnosis, Differential↗

PubMed1991

Aspiration and tetracycline sclerotherapy of hydrocele.

Seventeen patients with hydrocele of the testis were treated by aspiration of fluid and substitution with tetracycline supplemented with 1% lidocaine. In 15 patients (88%) symptoms disappeared by sclerotherapy. After sclerotherapy scrotal ultrasonography was useful to diagnose either relapse or thickened tunica vaginalis. No side effect was noticed.

Adolescent↗

PubMed1991

[Silica calculi: a case report].

A 66-year-old female visited our university hospital with the chief complaint of right lower abdominal pain in July, 1984. Kidney-ureter-bladder roentgenograms disclosed the right ureter stone and several left renal stones. She passed the right ureter stone composed of calcium oxalate. Thereafter, she passed small stones twice and sand stones twice until September, 1985. The stone analysis revealed two of them as silica. Although most patients with silica stones reported in Japan had a history of long-term medication of magnesium trisilicate, this patient had not taken this drug. Silica stones are rare and fifteen cases including the present case have been reported in Japan.

Aged↗

PubMed1991

[Clinical analysis of 35 patients with renal injury].

Because of the increase of abdominal trauma owing to traffic accident, the number of renal injury is increasing. Between May 1, 1986 and December 31, 1989, thirty-five cases with renal injury were treated in our hospital. The cases were classified as contusion, minor laceration, major laceration and vascular injury by the clinical findings and the radiographic evaluation. Contusion had 22 patients, who were treated conservatively except one with preexisting hydronephrosis. Four patients of minor laceration were all treated conservatively. In four cases of major laceration nephrectomy was performed, the other five cases were healed conservatively. There were two death cases caused by other organ injuries. The extent of associated injuries influenced the prognosis, rather than the degree of renal damage. Thirty-three cases except two survived with no complication. In cases of major injury same were managed conservatively, other required surgical treatment. Sometimes it is difficult to determine which treatment should be done. Indication for surgical treatment is discussed.

Accidents, Traffic↗