Toshiaki Higashida

Cl--ATPase and Na+/K+-ATPase activities in Alzheimer's disease brains

Abstract The enzyme activities and the protein levels of Cl − -ATPase and Na + /K + -ATPase were examined in Alzheimers disease (AD) brains. Cl − -ATPase and Na + /K + -ATPase activities in AD brains ( n =13) were significantly lower than those in age-matched control brains ( n =12). In contrast, there was no significant difference in anion-insensitive Mg 2+ -ATPase activity between the two groups. Western blot analysis revealed that the protein levels of Cl − -ATPase, Na + /K + -ATPase and neuron specific Na + /K + -ATPase α 3 isoform were also significantly reduced in AD brains, while the amount of protein disulfide isomerase, one of the house keeping membrane proteins, was not different between the two groups. The data first demonstrated that Cl − -ATPase and Na + /K + -ATPase are selectively impaired in AD brains, which may reduce the gradients of Na + , K + and Cl − across the cell membranes to cause excitotoxic cellular response and the resulting neuronal death.

Staphylococcus aureus Isolated from Nostril Anteriors and Subungual Spaces of the Hand: Comparative Study of Medical Staff, Patients, and Normal Controls

An epidemiologic investigation of methicillin‐resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus (S. aureus) colonization was conducted at Kansai Medical University Hospital between 1990 and 1991. The incidence of nasal and subungual positivity for S. aureus was examined in a total of 156 subjects including inpatients, physicians, and nurses at a ward for dermatology, plastic surgery, and emergency patients, outpatients with atopic dermatitis and other skin diseases, and normal controls. Inpatients were most heavily colonized with MRSA (40.8%), but S. aureus colonization was most frequent in outpatients with atopic dermatitis (95.5%). Not only nostrils, which have been much discussed as a reservoir of S. aureus, but also subungual spaces seemed to be havens of S. aureus. Twelve out of 22 atopic dermatitis patients were positive for S. aureus on skin regions, and coagulase and phage testing showed a correlation between the nasal and skin‐colonizing S. aureus. Coagulase type II and phase type NT (not typable) were the predominant types of S. aureus, including MRSA.

Antiserum against Cl− pump complex recognizes 51 kDa protein, a possible catalytic unit in the rat brain

We purified Cl- pump in the rat brain and obtained 520 or 580 kDa protein complexes which consisted of 62, 60, 55 and 51 kDa proteins. An antiserum against 520 kDa protein complex recognized 51 kDa protein in both 520 and 580 kDa complexes, and reduced both Cl(-)-ATPase and Cl(-) pump activities. Such an immunoreactive 51 kDa protein was found in the brain, spinal cord and kidney. When incubated with [gamma-(32)P]ATP, the protein complex yielded phosphorylated 51 kDa protein, the label being hydroxylamine-sensitive and increased in the presence of Cl- and/or an inhibitor of Cl- pump, ethacrynic acid. Thus, the antibody appears to recognize a possible catalytic subunit of Cl- pump, 51 kDa protein, in the rat.

An epidemiological study of methicillin-resistant Staphylococcus aureus (MRSA) isolated from medical staff, inpatients, and hospital environment in one ward at our hospital.

Methicillin‐resistant Staphylococcus aureus (MRSA) is one of the most important causative microorganisms for nosocomial infections. Recently, the incidence of isolation of MRSA has been increasing every year in Japan and is, notably, much more frequently found in inpatients than in outpatients. Therefore, we have done epidemiological studies of MRSA isolated from medical staff, inpatients, and the hospital environment in one ward of our hospital. Thereafter, we examined the antibiotic susceptibility (ABPC, DMPPC, CET, CMZ, IPM, GM, MINO, OFLX, EM, CLDM, VCM), phage typing, and coagulase typing of these MRSA MRSA were isolated more frequently from anterior nares of inpatients than from doctors and nurses. MRSA were isolated more frequently from the environment near carriers of MRSA

Antimicrobial resistance of Staphylococcus aureus isolated from impetigo patients between 1994 and 2000

Background The incidence of strains of Staphylococcus aureus resistant to the antimicrobial agents used in treating impetigo has been increasing.

Developmental changes in Cl−-ATPase activity in rat brains

Developmental changes in brain Cl(-)-ATPase activity were examined using fetal, neonatal and adult rats. The Cl(-)-ATPase activity rapidly increased over 20 postnatal days to a level four-fold higher than that in an 18-day-old fetus. On Western blot analysis using an anti-Cl(-)-ATPase/pump 51 kDa subunit (ClP51) antibody, the amount of ClP51 protein increased in parallel with Cl(-)-ATPase activity. Immunohistochemistry using the same antibody showed Cl(-)-ATPase-like immunoreactivity on the cell membranes of neurons such as cerebral and hippocampal pyramidal cells and cerebellar Purkinje cells, where the immunoreactivity increased with developmental changes in the size and shape of the neurons. These findings suggest that neuronal Cl(-)-ATPase activity markedly increases during early postnatal development with an increase in the amount of Cl(-)-ATPase protein, which may support the formation of inwardly directed neuronal Cl(-) gradients.