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Biomedical subjects

K Murakami

Publications and source records attributed to K Murakami.

At least 739 records · Page 41Linked to original sources
PubMed1992

Identification of bone morphogenetic protein-2 in early Xenopus laevis embryos.

Polyclonal antibodies capable of reacting with amphibian bone morphogenetic protein (BMP-2 and -4) were raised in rabbits by immunization with a synthetic 21 amino acid peptide which corresponds to a sequence residing in the mature protein of Xenopus BMP-2 (xBMP-2). The antibodies recognized an embryonic BMP as well as mammalian and bacteria expressed recombinant xBMPs. The antibodies detected, under reducing conditions, a 30 kDa protein in the extract of oocytes and embryos during early development. Interestingly, acidification of the extract from each developmental stage yielded a protein band of smaller molecular weight of 18 kDa, which is similar in size to reduced form of mature BMPs purified from mammalian species. Two-dimensional electrophoresis employed to examine the molecular weight of unreduced forms using the antibody, revealed that both molecular forms are monomeric in the embryos. The result suggests that at least BMP-2 mRNA previously detected in early embryos, is translated into peptide but the dimerization may be incomplete or strictly limited in these embryos.

Amino Acid Sequence↗
PubMed1992

Expression of rat renin in mammalian cells and its purification.

Rat renin cDNA was transfected into COS-7 and Chinese hamster ovary (CHO) cells and expressed under the control of the Simian Virus 40 early promoter. Conditioned media of the transfected cells showed renin activity only after trypsin treatment, suggesting prorenin was secreted into the medium. From the trypsinized serum-free culture of the transfected CHO cells active renin was purified to homogeneity by a simple three-step procedure. The active renin had similar specific activity, molecular weight, Km, pH optimum, and isoelectric point compared to native renin. The amino-terminal sequence was the same as that deduced from the renin cDNA. This suggests that the recombinant rat renin is similar to kidney renin in many respects, and is easily obtained by the present procedures.

Animals↗
PubMed1992

Diurnal variation and increase of disaccharidase activity in diabetic rats.

The small intestinal disaccharidase activity and its daily variation in the diabetic rat have not been well described. Therefore, the small intestinal disaccharidase (maltase, lactase and sucrase) activity and its daily profile were studied in streptozotocin-induced diabetic rats under physiological conditions. In diabetic rats, a similar pattern of diurnal variation of disaccharidase activity to control rats was observed, while the relationships between daily change of disaccharidase activity and that of food consumption suggested that there was a different mechanism of diurnal variation in diabetic rats. On the other hand, a significant increase of mean 24-h lactase and sucrase activities was noted in diabetic rats, while that of maltase was not significant. Using the in vitro incubation method, a significant correlation between glucose concentration and lactase or sucrase activity but not maltase activity was observed. However, insulin showed no effect on disaccharidase activity. Thus we clarified the presence of a diurnal variation of disaccharidase activity and an increase in its activity in diabetic rats. This change was suggested to be derived from high plasma glucose level.

Animals↗
PubMed1992

Comparative study of renin expression in the coagulating glands of C57BL/6 and Balb/c mice.

The comparative localisation of renin in the genital organs, especially in the coagulating glands of male mice of the strains C57BL/6 and Balb/c, was investigated using immunocytochemical, immunoelectron microscopical and Northern blot techniques. Dot-like reactions for renin, of varying diameters, were detected immunocytochemically in the epithelial cells of coagulating glands of C57BL/6 mice, but not in those of Balb/c mice. In both strains, many electron dense granules differing in content and morphology were observed in the epithelial cells of the coagulating glands. Crystalline materials were sometimes contained in these granules. Colloidal gold particles indicating the presence of renin were detected in the electron dense granules of C57BL/6 mice, in which they showed a heterogeneous distribution and were especially located on the crystalline structure. No positive reaction was detected in these crystalline structures in Balb/c mice. Renin mRNA was detected in the coagulating glands of both C57BL/6 and Balb/c mice by Northern blot analysis. However, the expression in C57BL/6 coagulating glands was stronger than that in Balb/c. These findings suggest that renin is synthesised and released in the coagulating glands.

Animals↗
PubMed1992

An application of ultrasonic tissue characterization to the diagnosis of cataract.

From a therapeutic and pathological point of view, it is important to classify types of cataract and to identify their stages. However, accepted criteria for quantitative diagnosis have not been established. On the other hand, based on the experience from tissue characterization applied to other clinical fields, the attenuation characteristics of the lens are expected to change according to the stage of disease and the type of cataract. In this study from echo signals we tried to measure the attenuation coefficient of the lens with the purpose of quantitatively diagnosing the cataract, and at an early stage. It is shown that the attenuation of the cataractous lens is larger than that of the normal lens and its value depends on the type of the cataract, an indication of the possibility of using tissue characterization in the evaluation of cataract.

Adult↗
PubMed1992

Effect of manidipine, a new calcium antagonist, on intrarenal hemodynamics in essential hypertension.

The effect of manidipine, a new Ca2+ antagonist, on intrarenal hemodynamics was assessed in essential hypertension and compared with nicardipine, a previously studied Ca2+ antagonist. Identical 2-week studies were repeated before and during the administration of manidipine (10 mg once daily, 2 weeks) in 3 patients with essential hypertension who were given regular- and sodium-restricted diets for 1 week each. The renal function curve (pressure-natriuresis relationship) was drawn by plotting the urinary sodium excretion rate on the y-axis as a function of the systemic mean arterial pressure (MAP) on the x-axis. Assuming that the difference between MAP and the extrapolated x-intercept of the renal function curve represents the effective filtration pressure across the glomerular capillary walls, the intrarenal hemodynamics were calculated (e.g., afferent arteriolar resistance (RA), efferent arteriolar resistance (RE), and glomerular pressure (PG)). During the regular sodium diet, MAP was lowered from 100 +/- 7 to 93 +/- 5 mmHg (p < 0.04) and the effective filtration pressure was lowered from 20 +/- 2 to 10 +/- 3 mmHg (p < 0.05); the renal plasma flow rate (pre: 560 +/- 74 vs. post: 627 +/- 108 mL/min) and glomerular filtration rate (82 +/- 10 vs. 78 +/- 5 mL/min) were not altered. RA remained unchanged (3,800 +/- 700 vs. 3,400 +/- 300 dyn.sec.cm-5; % reduction: 4 +/- 16%) whereas RE was reduced from 4,300 +/- 700 to 3,300 +/- 800 dyn.sec.cm-5 (19 +/- 15%). Thus, PG was lowered from 58 +/- 2 to 50 +/- 2 mmHg (13 +/- 3%), which parallels with the reduction in MAP.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1992

[Histopathological characteristics of rheumatoid arthritis--as a clue to elucidate its pathogenesis].

A correct histopathological diagnosis of Rheumatoid Arthritis (RA) is quite important for the decision of early phase treatment to cure it fundamentally. But, generally speaking, usual hospital pathologist is not so much experienced about RA. The purpose of this article is originally to let such pathologist familiar in RA pathology, but for the RA specialist to offer any clue to elucidate the still-unknown etio-pathogenesis of RA or to cure RA fundamentally. The "Tetralogy of RA Arthritis for pathologist" must be as follows: (1) Enormous proliferation of well-permeable granulation-tissue-type neo-vascularization, some of which became high column-endothelial and the center of primary as well as secondary follicle-like lymphoid cell cluster. (2) Lymphoid cluster in RA synovium is also pathological in function. It consisted of preferentially CD4T and B cells to produce IgG rheumatoid factor endlessly. (3) Synovial lining A and B cells proliferate as far as five layers of each, but later, the sublining D (M) and D (F) cells proliferate more and more and finally replace the lining cells. D (M) cells express macrophage marker and full of lysosome, on the contrary, D (F) cells express mesenchymal marker and contains much metalloproteinase. Both express strong Class II antigens but neither has complement activation inhibitor DAF. (4) Proliferation of these D cells with full of mesenchymal tissue destroying and inflammation accelerating activity must be playing a major role in the joint destruction of RA, some in shape of pannus and more in shape of granulation tissue in and around the bone.

Arthritis, Rheumatoid↗
PubMed1992

[Renin].

Explore the source record for details and available documents.

Carbohydrate Conformation↗
PubMed1992

Phenol block for hip flexor muscle spasticity under ultrasonic monitoring.

Hip flexor spasticity, which is often associated with central nervous system (CNS) diseases, is a major impediment in rehabilitation. In order to cope with this problem, lumbar nerve blocking techniques developed by Meelhuysen and major and minor psoas muscle blocking techniques developed by Awad have been used in combination with physical therapies. Based on these techniques, we conducted major and minor psoas muscle phenol block (motor point block or intramuscular nerve block) under ultrasonic monitoring. Phenol block was conducted in nine patients with cerebral infarction (13 blocking procedures) and three with spinal cord injuries (six blocking procedures) while keeping them in a lateral position with the operation side upside. The beginning of the femoral nerves and part of the lumbar artery were visualized by ultrasound in some patients. As a result of the improvement of hip flexor spasticity, the range of hip joint motion (determined by the Mundale technique, prone hip extension and Thomas test) improved shortly after blocking. When physical therapy was conducted after blocking, improvement of skin care management was observed in eight cases, ability to keep in a stable sitting position in nine, improvement of a standing posture in three, increases in the ability to walk in two and alleviation of pain in three. Although nerve block is reported to result in hematoma, decreases in muscle force, pain, cystic/rectal disorders and hypogonadism, we have observed no such complication in our patients.

Adult↗
PubMed1992

The association between salt sensitivity of blood pressure and family history of hypertension.

1. The salt sensitivity index (SSI) and family history of hypertension were studied in 140 hospitalized patients with essential hypertension to clarify whether salt sensitivity of blood pressure is related to familial disposition to hypertension. 2. SSI was calculated by dividing the change of mean blood pressure by that of urinary sodium excretion when salt intake was restricted from 15 to less than 3 g/day. 3. Family history of hypertension was classified into three groups depending on the presence or absence of hypertension in the father, mother and siblings. 4. The group without a family history of hypertension showed a significantly lower SSI value than other groups. 5. In multiple regression analysis undertaken within each gender, SSI showed significant partial correlations with blood pressure and family history of hypertension in the female group (r = 0.402 and 0.265, respectively), whereas in the male group it showed a positive correlation only with blood pressure (r = 0.501). These results indicate that salt sensitivity of blood pressure is related to familial disposition to hypertension. This association was more apparent in the female than male group and its gender difference can be partially attributed to the fact that blood pressure in the female group is more sensitive to salt.

Blood Pressure↗
PubMed1992

[A case of rheumatoid arthritis with immunotactoid glomerulopathy].

The patient was a 64-year-old female who had been treated by a local doctor for rheumatoid arthritis and hypertension for 10 years. Malaise and edema developed since July, 1990, and as proteinuria and renal dysfunction were noted, the patient was admitted to our hospital on November 2. On admission, BUN was 33mg/dl, creatinine was 2.5mg/dl, and proteinuria was about 3g/day. Renal biopsy was performed after admission. Light microscopy revealed nodular lobulation of glomeruli and occlusion of loops. Dylon staining was negative. Immunofluorescent study showed granular deposition of IgG, IgM, C3, C4, Clq in the glomerular basement membrane and mesangial area. Electron microscopy showed a large amount of electron dense deposits in the subendothelium and mesangial area and dense aggregation of tubular structure in the deposit, part of which exhibited a profile of fingerprint deposit. The tubular structures were classified into three major types, which were 120, 100, and 50nm in diameter. From these findings, a diagnosis of immunotactoid glomerulopathy was made. After renal biopsy, plasmapheresis and prednisolone were administered, and the patient has been managed conservatively to date.

Arthritis, Rheumatoid↗
PubMed1992

[Growth factors: a regulator of renal function].

We selectively focus on two growth factors, epidermal growth factor (EGF) and insulin-like growth factor (IGF), and discuss their roles on regulation of renal function and associated diseases conditions, as well. EGF, 6 kD polypeptide, is derived by proteolysis from a large precursor (prepro EGF, 133 kD). Prepro EGF is a membrane-anchored protein and its mRNA is predominantly localized to distal tubules of mouse and rat kidneys. We immunohistochemically demonstrated the glomerular distribution of EGF and EGF-receptor in normal and nephritic human kidneys. The physiologic roles of EGF produced in the kidney are various; it is mitogenic for tubular epithelial cell, inhibits gluconeogenesis and salt and water reabsorption in the tubules, and effects on glomerular hemodynamics. Alteration of renal EGF expression is suggested in renal ischemic injury, renal hypertrophy and cystic renal disease. IGF-I, somatomedin-C, is produced in collecting duct, and glomerular cells, and exerts a variety of actions on kidney. IGF-I stimulates gluconeogenesis in renal tubules, and is mitogenic for mesangial cells. The administration of this growth factor increases glomerular filtration rate. Enhanced expression of renal IGF-I was observed in the uninephrectomized animals.

Animals↗
PubMed1992

[Changes in right ventricular function with unilateral pulmonary artery occlusion test for pre-operative evaluation prior to lung resection].

We measured the right ventricular ejection fraction (RVEF) before and during unilateral pulmonary artery occlusion test (UPAO) by thermodilution method. We also measured the right ventricular end-diastolic volume index (RVEDVI), right ventricular end-systolic volume index (RVESVI), and right ventricular stroke volume index (RVSVI). RVEF and RVSVI were significantly decreased by UPAO (p less than 0.05), but there were no obvious changes in RVEDVI and RVESVI. Some cases showed only a small decrease in RVEF by UPAO, even though their total pulmonary vascular resistance indices were over 700 dyne.sec.cm-5/m2 during UPAO. On the other hand, some cases had a decreased in RVEF of more than 10% by UPAO, even though their total pulmonary vascular resistance indices were under 400 dyne.sec.cm-5/m2 during UPAO. We consider that it is important to measure right ventricular functions such as RVEF together with pulmonary vascular hemodynamics in the pre-operative evaluation of cases of lung resection.

Aged↗
PubMed1992

[Application of laser in the treatment of spontaneous pneumothorax and emphysema].

From August 1990 to August 1991, sixteen patients with bullae or blebs (pneumothorax 9, giant bullae 5, bullous emphysema 2) were treated by CO2 laser ablation under limited thoracotomy. We found the irradiation of bullae or blebs by CO2 laser quite effective in eliminating these bullous lesions which were often multiple and inoperable by conventional methods. Histological examination revealed the wall of bullae where CO2 laser was applied became thick with dense fibrous tissues and degenerated collagen fibers which, however, were not disrupted. The procedure was safe and we were able to operate patients with disabling emphysema. Because CO2 laser can penetrate only 0.2-0.3 mm of tissue thickness, it is suitable for the ablation of bullous lesions which have thin walls and rapidly shrink and collapse by irradiation leaving thick walled scar tissues. Removing multiple bullae and blebs in patients with bullous emphysema can improve gas exchange by reducing dead spaces and elevating the diaphragm which is often flat and downward displaced because of hyperinflation in these patients. We are planning to incorporate thoracoscopy for this operation to make the procedure less invasive.

Adolescent↗