[Effect of swimming on the distribution of metallic mercury in mice].
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Biomedical subjects
Publications and source records attributed to S Yamaguchi.
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A female infant presenting congenital ascites, hepatosplenomegaly, coarse face, and delayed mental and physical development is described. Oligosaccharides in the urine and the abdominal ascites of this patient were investigated by Bio-Gel column chromatography. The level of urinary oligosaccharides excreted (nmol/mg creatinine) by the patient was 25.8 times the levels of the controls. The oligosaccharides in the urine and the ascites were composed almost entirely of sialyl oligosaccharides. The structures of urinary oligosaccharides were the same as those of oligosaccharides in the ascites. The ratio of high molecular weight sialyl oligosaccharides with repeating structures to low molecular weight sialyl oligosaccharides was higher in the ascites than in the urine.
We examined the mutant protein of mitochondrial acetoacetyl-CoA thiolase (mutant T2) in fibroblasts from a Japanese boy with 3-ketothiolase deficiency. The molecular size of the mutant T2 protein, determined by pulse labeling and SDS/PAGE, was intermediate between the mature subunit and the precursor of T2. To characterize the mutant T2 protein, pulse-labeling and rhodamine 6G inhibition of mitochondrial transport in fibroblasts, cell-free translation experiments, and family studies by thiolase assay, immunoblotting, and pulse-labeling were carried out. The mutant T2 was detectable as early as a 10-min pulse. The probable precursor of the mutant T2 was not detectable in either the rhodamine 6G inhibition or cell-free translation experiments. In the parents, the K+ ion dependency of acetoacetyl-CoA thiolase activity was low and the T2 bands in immunoblots were faint. It would thus appear that the parents are heterozygotes of this disease. In pulse-labeling, only a band for the mutant T2 was detected in the patient and a single band for the normal mature subunit of T2 in the father; both bands were detected in the mother. These findings suggested that the mutant T2 in the patient was inherited from the mother, and that the expression of another mutant allele of the father may be either abolished or scanty.
Using sections of formalin-fixed, paraffin-embedded tissues from 64 colorectal cancer patients, the expression of c-erbB-2 oncoprotein was studied immunohistochemically. Twenty-seven percent of the cases with liver metastasis showed positive staining. On the other hand, only 3% of cases without liver metastasis were positive. Expression rates of c-erbB-2 protein in liver metastasis cases showed no significant difference between primary operation (26%) and recurrence (27%). Of all c-erbB-2 positive patients, 90% (9/10) had liver metastasis. Secondly, vessel invasions of 45 rectal cancer patients were studied using Victoria Blue (VB) elastic staining and endothelial staining by factor VIII-related antigen and Ulex europaeus agglutinin I (UEA-I) lectin. VB-HE double stain was efficacious to detect vascular invasion, but endothelial staining was not. There were statistically more vascular invasions in 30 patients with liver or lymph node metastases than in those without metastasis. And in cases with metastasis, many vascular invasions into the extra-muscular layer were seen. Both vascular invasions and c-erbB-2 protein were valuable indicators of possible liver metastasis.
A case report of 3-ketothiolase deficiency due to a defect of mitochondrial acetoacetyl-CoA thiolase protein in a Brazilian boy and its biochemical investigation is presented. The child had moderate generalized hypotonia, EEG alterations and crises of metabolic acidosis following infections. Hypotonia and EEG abnormalities disappeared with a low protein diet, and physical and mental development are normal. Urinary organic acid excretion was typical of 3-ketothiolase deficiency, showing consistently high levels of 2-methyl-3-hydroxybutyric acid and tiglylglycine. Activation of acetoacetyl-CoA thiolase activity by potassium (K) ion in cultured fibroblasts was not observed, demonstrating the lack of activity of mitochondrial acetoacetyl-CoA thiolase. In addition, the signal for the mitochondrial acetoacetyl-CoA thiolase protein was undetectable in the immunoblot analysis. In the pulse-chase experiments, the signal for mitochondrial acetoacetyl-CoA thiolase was detected after a 1-h pulse but not after a 24-h chase. These results indicate that the deficiency was caused by an unstable mitochondrial acetoacetyl-CoA thiolase protein.
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The effect of a single oral dose of nicorandil (N-2-(hydroxyethyl)-nicotinamide nitrate, CAS 65141-46-0) on the regional cerebral blood flow (rCBF) was studied in 9 patients with cerebral infarction. The rCBF was measured by the Xe-133 inhalation method before and after a single oral 10 mg dose of nicorandil. Mean arterial blood pressure (MABP) was mildly but significantly decreased. PeCO2 did not change significantly. Mean rCBF was significantly increased by 20.9% after administration of nicorandil (p less than 0.05). No significant correlation between percentage change in the MABP and percentage change in the rCBF was observed. These results indicate that nicorandil is not just a coronary vasodilator, but also possesses beneficial effects on the cerebral circulation in patients with cerebral infarction.
Fluorescein isothiocyanate (FITC)-labeled red blood cells (RBCs) and rhodamine-B isothiocyanate (RITC)-labeled dextran were used as two fluorescent tracers under intravital fluorescence microscopy. RBC velocity in cerebral microvessels of cats was measured with a dual window technique using FITC-labeled RBCs as a flow tracer. Measurement of the vessel diameter was performed using a digital image processor system by staining plasma with RITC-labeled dextran. The RBC velocity, obtained directly with digital cross-correlation of videodensitometric signals derived from the two windows, coincided with those obtained with the frame-by-frame analysis. The obtained RBC velocity ranged between 12.9 and 0.45 mm/sec in arterioles (< 60 microns) in diameter, 4.2 and 0.18 mm/sec in venules (< 60 microns in diameter), and 1.1 and 0.26 mm/sec in capillaries. The use of the labeled RBCs as the flow tracer enabled us to measure a wide range of RBC velocity (up to about 7 mm/sec) by setting the distance between the two windows beyond about 200 microns.
Photopic electroretinograms were elicited in anesthetized monkey eyes with stimulus light of various intensities under background light of different luminances. The b-wave implicit time was prolonged with increasing stimulus light intensity and shortened with brighter background luminance. While the change of anesthetic conditions produced by the addition of halothane (0.5% or 1.0%) mildly prolonged the implicit time, it affected neither the waveforms nor the relationship between the b-wave implicit time and background luminance.
In the kidney, adenosine plays important regulatory roles, including renal blood flow, glomerular filtration rate, renin secretion, tubuloglomerular feedback, tubular reabsorption of sodium and water, sympathetic neurotransmitter release, and erythropoietin secretion. These functions are mediated through adenosine 1 (A1)-receptors and adenosine 2 (A2)-receptors. These receptors couple to the inhibition and stimulation of adenylate cyclase, through Gi and Gs proteins, respectively. A variety of other effecter systems have been reported to be coupled to A1 receptors, including phospholipase C, phospholipase A2 and potassium, as well as Ca++ channels. Recently, A1 receptors, A2 receptors and novel A2 receptor have been cloned, sequenced and expressed. In association with the development of selective adenosine analogues, we are now ready to take up problems at the biochemical and molecular biological levels.
We evaluated regional blood flow and oxygen metabolism in the cerebral and cerebellar cortices of 15 patients with unilateral major cerebral artery occlusive disorders with PET. These patients showed a cortical blood flow asymmetry in middle cerebral artery distribution. Only subcortical abnormalities were detected on computed tomography. Nine patients showed crossed cerebellar hypoperfusion, a reduction in contralateral cerebellar blood flow, while six did not. No difference in the degree of cerebral blood flow asymmetry existed between the two patient groups. However, oxygen metabolism asymmetry was more pronounced and was more closely matched to blood flow asymmetry in patients with crossed cerebellar hypoperfusion. These findings suggest that a major cause of cerebral cortical blood flow reduction is reduced metabolic demand in patients with crossed cerebellar hypoperfusion. Crossed cerebellar hypoperfusion may have clinical significance as a reflection of the cerebral metabolic state on blood flow images.
The authors studied the effect of stimulus intensity and background luminance on the b-wave implicit time of photopic electroretinogram in normal human eyes. Photopic electroretinograms were recorded at various stimulus intensities and background luminances in the range of 2.5 log scale using an integrating sphere of 30 cm diameter in the first experiment. The results from two normal eyes showed that with increasing stimulus intensity or with decreasing background luminance the b-wave implicit time of photopic electroretinogram prolonged and one or three wavelets superimposed on the ascending limb of the b-wave. The second experiment was performed using a half dome sphere of 60 cm diameter to study the b-wave implicit time at three different stimulus intensities. The results from 30 normal eyes disclosed a statistically significantly longer implicit time at the greater stimulus intensities. These results suggest that b-wave implicit time in photopic electroretinogram becomes delayed with increasing stimulus intensity and becomes shorter with brighter background luminance.
Six cases of sector retinitis pigmentosa were studied by automated static perimetry and photopic electroretinogram. Four cases out of six revealed elevated thresholds in the lower half of the visual field, which corresponded to the normally appearing upper eyeground. They also showed delayed implicit time on the photopic electroretinogram. These results show that sector retinitis pigmentosa is not necessarily a regional retinal dystrophy.
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We performed parathyroidectomy for renal osteodystrophy due to secondary hyperparathyroidism on 16 patients with chronic renal failure who were refractory to medical management; subtotal parathyroidectomy on one patient and total parathyroidectomy with autotransplantation on 15 patients. Postoperative clinical improvement, i.e., bone and/or joint pain, pruritus and radiographic signs of renal osteodystrophy, was marked. After the operation, serum calcium decreased rapidly and adequate calcium replacement therapy was necessary. The levels of intact parathyroid hormone decreased rapidly and serum concentration of alkaline phosphatase gradually decreased for a few months postoperatively. Recurrence was diagnosed in one patient, who underwent excision of the transplanted parathyroid tissue. Osteomalasia due to hypoparathyroidism was not seen clinically in this series. In preoperative image diagnosis, ultrasonotomogram (US) showed the highest detective rate of the enlarged parathyroid glands. However, combination of US, computerized tomography and 99mTcO4(-)-201T1C1 scintigram can be recommended as a localizing diagnostic method for compensating the disadvantages of each method. Clinical results after parathyroidectomy for secondary hyperparathyroidism are considered to be good. However, long-term followup is mandatory for early detection of persistent hyperparathyroidism or hypoparathyroidism.
The first case was in a 48-year-old man admitted with a chief complaint of macroscopic hematuria and sense of residual urine. A tumor in the diverticulum of the bladder was detected by cystoscopy, computed tomography (CT) and magnetic resonance imaging (MRI). We made the diagnosis of an invasive tumor in the diverticulum of the bladder. Total cystourethrectomy and ileal conduit diversion was performed. Histopathological finding was transitional cell carcinoma including squamous cell carcinoma. Adjuvant chemotherapy was performed. No recurrence and metastasis has been recognized for 12 months. The second case was a 56-year-old man having an intradiverticular tumor diagnosed by cystoscopy, CT, and MRI. Total cystectomy and ileal conduit diversion was performed. Histopathological findings was squamous cell carcinoma. No recurrence has been recognized for 8 months. The last case was an 81-year-old man. The patient had the complication of a primary progressive squamous cell carcinoma of the skin. Transurethral resection of diverticular tumor was performed under the diagnosis of superficial tumor. Histopathological findings revealed transitional cell carcinoma. One hundred and sixty one cases of tumor in the diverticulum of the bladder were reviewed. Importance of aggressive treatment including total cystectomy was emphasized.
To examine 3-ketothiolase deficiency at the gene level, we analyzed the structure of the human mitochondrial acetoacetyl-CoA thiolase (MAT; EC 2.3.1.9)-encoding gene (MAT). From the genomic library of a normal subject in lambda EMBL3, we isolated seven overlapping clones covering the entire length of MAT and the structural organization was determined. The gene spans approx. 27 kb and contains twelve exons interrupted by eleven introns. The 5'-flanking region of the gene lacks a conventional TATA box, but is G + C-rich and contains two CAAT boxes. Included are a putative binding site for the transcription factor, Sp1, and sequences resembling the binding sites of several other transcription factors, all features characteristic of housekeeping genes. A CAT assay revealed that a 101-bp DNA fragment immediately upstream from the cap site has promoter activity, and suggested that a DNA fragment from bp -888 to -102 probably contains a negative regulatory element(s).