Masayukin Nomura

Bio: Masayukin Nomura is an academic researcher. The author has contributed to research in topics: Angiotensin receptor & Angiotensin II receptor type 1. The author has an hindex of 1, co-authored 1 publications receiving 29 citations.

Autopsy findings in the acquired immune deficiency syndrome.

Abstract: The medical records, premortem biopsy specimens, and autopsy materials from 36 patients with acquired immune deficiency syndrome (AIDS) were reviewed. The majority of the patients were homosexual men. Widely metastatic Kaposi's sarcoma was seen in eight patients, while tumor was confined to the skin in an additional ten. Four patients had high-grade lymphomas. Thirty-five of the 36 patients had at least one opportunistic infection at some point in the course of their illness. Many patients had multiple infectious agents. The most consistent and striking autopsy finding was a severe depletion of lymphoid tissues. Death in the majority (83%) of the patients was attributable to opportunistic infections affecting most commonly the respiratory tract (64%) and meninges (11%). Three patients (9%) died with widely metastatic Kaposi's sarcoma and secondary hemorrhage. ( JAMA 1984;252:1152-1159)

Hemodynamic and endocrine changes associated with potassium supplementation in sodium-loaded hypertensives.

Abstract: To clarify the mechanism by which potassium (KCl) protects against the blood pressure rising action of sodium (NaCl), we studied the effects of KCl loading in patients with idiopathic hypertension who, after a period of NaCl restriction, partook of a high NaCl diet. Eleven patients who had taken the KCl supplement (96 mEq/day) during the high NaCl period showed lesser mean blood pressure (MAP) rise with changes in NaCl intake from 25 to 250 mEq/day than 12 patients who had not taken the KCl supplement (p less than 0.001). With a high NaCl diet, the KCl-supplemented patients retained less NaCl, gained less weight, and showed a lesser increase in plasma volume and cardiac output than the non-KCl-supplemented ones. Overall, the increase in blood pressure levels during the high Na diet correlated directly either with changes in plasma volume (p less than 0.05) or with changes in cardiac output (p less than 0.01). The results suggest that KCl may prevent a rise in blood pressure with NaCl loads in hypertensive patients by attenuating the increase in cardiac output, mainly as a result of the natriuresis. Furthermore, plasma norepinephrine was measured to estimate the sympathetic activity, since the sympathetic nervous system is known to control urinary NaCl excretion. From the low NaCl diet to Day 3 of the high NaCl diet, plasma norepinephrine was significantly (p less than 0.01) decreased in the KCl-supplemented patients, whereas it remained unchanged in the non-KCl-supplemented ones.(ABSTRACT TRUNCATED AT 250 WORDS)

Infantile variant of Bartter syndrome and sensorineural deafness: a new autosomal recessive disorder.

Abstract: The infantile variant of Bartter syndrome (IBS) is usually associated with maternal polyhydramnios, premature birth, postnatal polyuria and hypokalemic hypochloremic metabolic alkalosis and a typical appearance. IBS is thought to be an autosomal recessive trait. Several congenital tubular defects are associated with sensorineural deafness (SND). However, an association between the IBS and SND has not been reported so far. Here we describe 5 children of an extended consanguineous Bedouin family with IBS and SND. In 3 of the cases, the typical electrolyte imbalance and facial appearance were detected neonatally. SND was detected as early as age 1 month, suggesting either coincidental homozygotization of 2 recessive genes or a pleiotropic effect of one autosomal recessive gene. This association suggests that evaluation of SND is warranted in every case of IBS.

Kinetics and crystal structure of the wild-type and the engineered Y101F mutant of Herpes simplex virus type 1 thymidine kinase interacting with (North)-methanocarba-thymidine.

Abstract: Kinetic and crystallographic analyses of wild-type Herpes simplex virus type 1 thymidine kinase (TKHSV1) and its Y101F-mutant [TKHSV1(Y101F)] acting on the potent antiviral drug 2‘-exo-methanocarba-thymidine (MCT) have been performed. The kinetic study reveals a 12-fold KM increase for thymidine processed with Y101F as compared to the wild-type TKHSV1. Furthermore, MCT is a substrate for both wild-type and mutant TKHSV1. Its binding affinity for TKHSV1 and TKHSV1(Y101F), expressed as Ki, is 11 μM and 51 μM, respectively, whereas the Ki for human cytosolic thymidine kinase is as high as 1.6 mM, rendering TKHSV1 a selectivity filter for antiviral activity. Moreover, TKHSV1(Y101F) shows a decrease in the quotient of the catalytic efficiency (kcat/KM) of dT over MCT corresponding to an increased specificity for MCT when compared to the wild-type enzyme. Crystal structures of wild-type and mutant TKHSV1 in complex with MCT have been determined to resolutions of 1.7 and 2.4 A, respectively. The thymine moiety o...