PubMed HealthSearch

Biomedical subjects

K Uegaki

Publications and source records attributed to K Uegaki.

17 recordsLinked to original sources

Archaerhodopsin-2, from Halobacterium sp. aus-2 further reveals essential amino acid residues for light-driven proton pumps.

We have isolated a retinal protein which differs from bacteriorhodopsin and archaerhodopsin and pumps out as many protons in the light as those proton pumps. We tentatively named it archaerhodopsin-2. We have cloned and sequenced the gene that encodes archaerhodopsin-2. The gene consists of 780-bp nucleotides for 259 amino acids with a molecular mass of 27,937 Da. The amino acid sequence of archaerhodopsin-2 is 56% identical to bacteriorhodopsin and 88% to archaerhodopsin, with a few gaps of a few amino acids in both cases. Although the amino acid sequence of archaerhodopsin has revealed 157 conserved residues common to bacteriorhodopsin, the sequence of archaerhodopsin-2 reduces that number to 133. Of these, 38 amino acids are also common to chloride pumps and 24 to all bacterial retinal proteins known to date.

Amino Acid Sequence

Australian Halobacteria and their retinal-protein ion pumps.

Halophiles collected in Western Australia have been found to be examples of extremely halophilic rod-shaped archaebacteria, members of the genus Halobacterium. Most of them contain retinal proteins, and these proteins differ from one another and also from both bacteriorhodopsin (bR) and halorhodopsin [and sensory rhodopsins (sR)] isolated from Halobacterium salinarium (halobium), as revealed by their peptide maps and amino acid sequences. However, these retinal proteins still have the ability to pump protons or chloride ions in the light. These new ion pumps, designated archaerhodopsins (aR) [Mukohata et al. (1988) Biochem. Biophys. Res. Commun. 151, 1339-1345], are almost identical in terms of their molecular sizes and transient photochemical properties to the ion pumps identified previously. Differences are found in the: (1) apparent extinction coefficient of dark/light-adapted aR-2; (2) titration profiles at acidic pH of the absorption spectra of all aRs; and (3) circular dichroism spectra, which are influenced by the coexistent isoprenoid bacterioruberin. The amino acid sequences of two proton pumps from the Australian halobacteria, namely aR and aR-2, are approximately 90% homologous and both sequences are about 60% homologous with that of bR. Hydropathy plots suggest that these pumps also have a seven-helical structure similar to that of bR. The amino acid residues are highly conserved in the helical regions, in particular in the case of helices C and G (91 and 84%, respectively), among the three proton pumps.

Amino Acid Sequence

E-rosetting of guinea pig lymphocytes with lyophilized rabbit red cells after treatment with papain and glutaraldehyde.

Guinea pig lymphoid cells were reacted to form spontaneous rosettes (E-rosettes) with rabbit red blood cells before and after treatment with papain or a very low concentration (0.01%) of glutaraldehyde alone or both. The papain-glutaraldehyde-treated cells showed as high ability as papain-treated cells to rosette with lymphoid cells prepared from thymus, spleen, lymph node and peripheral blood of guinea pigs. Moreover, papain-glutaraldehyde-treated red cells were lyophilized and stored for 1 year without any change in their ability to form E-rosettes with these lymphoid cells. Binding between lymphocytes and treated or nontreated red cells was completely inhibited by specific anti-guinea pig thymocyte serum. Furthermore, a lymphocyte population enriched for B cells from lymph nodes or leukemic cells of strain 2 guinea pigs (B cells) did not show any substantial E-rosettes with nontreated or treated red cells. Scanning electron microscopy revealed no surface alteration in the treated cells when compared to those in nontreated red cells.

Aldehydes

[Bacteriological and clinical studies of cefoxitin with special reference to anaerobic infections in the patients of abdominal surgery (author's transl)].

Both bacteriological and clinical studies of the effectiveness of cefoxitin (CFX) in the treatment of infections associated with abdominal surgery have been carried out at Tokyo Metropolitan Toshima Hospital from September 1979 through August 1980. The results of these studies are summarized in the following: 1. The clinical isolates from the 29 surgical patients were studied and anaerobes were found in 16 patients (55% of the patients). B. fragilis was found in 11 of the 16 patients (69%) from whom anaerobes were isolated. In all of these patients, aerobes were also isolated--most frequently E. coli or K. pneumoniae. 2. The in vitro antibacterial activity of cefoxitin (CFX) against 83 clinical isolates was compared to that of cephalothin (CET), cefazolin (CEZ) and carbenicillin (CBPC). The activity of CFX against Gram-positive bacteria was generally slightly inferior to that of the other 3 antibiotics. Among the Gram-negative aerobic organisms, CEZ was the most active against E. coli and CFX and CEZ against K. pneumoniae. However, CFX, with MIC's of 0.78-12.5 micrograms/ml, showed the greatest activity against B. fragilis, followed by CBPC, CEZ and CET, in order of decreasing activity. 3. CFX was administered in a 1-hour drip infusion to 3 patients following abdominal surgery, and concentrations of CFX in the serum and the exudate were measured. Peak serum concentrations were obtained at the end of the infusion, with a mean peak level of 97.93 micrograms/ml. Peak concentrations in the exudate were observed 30 to 60 minutes later and varied from 21.10 to 56.25 micrograms/ml. 4. Of the 20 patients administered of CFX, complete clinical and bacteriological data of anaerobic infections were available in 8 patients. The clinical evaluation was 'good' in 7 patients and 'fair' in 1. The bacteriological evaluation was 'eradicated' in 5 patients and 'decreased' in 3. As for side effects, elevations of S-GOT and S-GPT were observed in 4 of the 20 patients received CFX, but these abnormalities might also be attributable to other factors such as underlying disease, surgical intervention etc. No other side effects were found in these patients.

Abdomen

[Cardiospasm].

Explore the source record for details and available documents.

Adult