Determinants of Slow Walking Speed in Ambulatory Patients Undergoing Maintenance Hemodialysis

Walking ability is significantly lower in hemodialysis patients compared to healthy people. Decreased walking ability characterized by slow walking speed is associated with adverse clinical events, but determinants of decreased walking speed in hemodialysis patients are unknown. The purpose of this study was to identify factors associated with slow walking speed in ambulatory hemodialysis patients. Subjects were 122 outpatients (64 men, 58 women; mean age, 68 years) undergoing hemodialysis. Clinical characteristics including comorbidities, motor function (strength, flexibility, and balance), and maximum walking speed (MWS) were measured and compared across sex-specific tertiles of MWS. Univariate and multivariate logistic regression analyses were performed to examine whether clinical characteristics and motor function could discriminate between the lowest, middle, and highest tertiles of MWS. Significant and common factors that discriminated the lowest and highest tertiles of MWS from other categories were presence of cardiac disease (lowest: odds ratio [OR] = 3.33, 95% confidence interval [CI] = 1.26–8.83, P<0.05; highest: OR = 2.84, 95% CI = 1.18–6.84, P<0.05), leg strength (OR = 0.62, 95% CI = 0.40–0.95, P<0.05; OR = 0.57, 95% CI = 0.39–0.82, P<0.01), and standing balance (OR = 0.76, 95% CI = 0.63–0.92, P<0.01; OR = 0.81, 95% CI = 0.68–0.97, P<0.05). History of fracture (OR = 3.35, 95% CI = 1.08–10.38; P<0.05) was a significant factor only in the lowest tertile. Cardiac disease, history of fracture, decreased leg strength, and poor standing balance were independently associated with slow walking speed in ambulatory hemodialysis patients. These findings provide useful data for planning effective therapeutic regimens to prevent decreases in walking ability in ambulatory hemodialysis patients.     

Synthesis and conformational analysis of aib-containing peptide modelling for N-glycosylation site in N-glycoprotein

A tetrapetide containing an Aib residue, Boc-Asn-Aib-Thr-Aib-OMe, was synthesized as a peptide model for the N-glycosylation site in N-glycoproteins. Backbone conformation of the peptide and possible intramolecular interaction between the Asn and Thr side chains were elucidated by means of n.m.r. spectroscopy. Temperature dependence of NH proton chemical shift and NOE experiments showed that Boc-Asn-Aib-Thr-Aib-OMe has a tendency to form a β-turn structure with a hydrogen bond involving Thr and Aib⁴ NH groups. Incorporation of Aib residues in the peptide model promotes folding of the peptide backbone. With folded backbone conformation, carboxyamide protons of the Asn residue are not involved in hydrogen bond network, while the OH group of the Thr residue is a candidate for a hydrogen bond in DMSO-d₆ solution.     

EnterohemorrhagicEscherichia coli O157:H7 possesses somatic (O) antigen identical with that ofSalmonella O301

The O antigen of enterohemorrhagicEscherichia coli O157:H7 is identical with that ofSalmonella O30₁ and is also related toSalmonella O30₁30₂ in an a-a, b type of relationship.     

Unusual solvent effect on protease activity and effective optical resolution of amino acids by hydrolytic reactions in organic solvents

Summary The catalytic activities of -chymotrypsin, subtilisin Carlsberg, and subtilisin BPN' for hydrolysis of amino acid esters in acetonitrile-water were unusually dependent on the solvent composition. The products obtained as precipitates in high concentrations of acetonitrile were L-amino acids of high optical purities, and effective optical resolution of amino acids was achieved.     

A novel opioid peptide, leumorphin, acts as an agonist at the kappa opiate receptor

The primary structure of the common precursor of porcine beta-neo-endorphin and dynorphin (preproenkephalin B) has shown the existence of a third leucine-enkephalin (leu-enkephalin) sequence with a C-terminal extension of 24 amino acids. This nonacosapeptide, named leumorphin, was approximately 70 times more potent than leu-enkephalin in inhibiting the contraction of the myenteric plexus-longitudinal muscle preparation of the guinea pig ileum. This action of leumorphin, like those of beta-neo-endorphin and dynorphin, was antagonized less effectively by naloxone than that of leu-enkephalin, but more effectively by Mr2266, an antagonist relatively specific for the kappa type opiate receptor. The inhibitory action of leumorphin or beta-neo-endorphin on the contraction of the guinea pig ileum muscle strip was reduced in a dose-dependent manner by pretreatment with dynorphin and vice versa. Leumorphin as well as beta-neo-endorphin and dynorphin inhibits the contraction of the rabbit vas deferens which is known to have only the kappa type opiate receptor. This action was also effectively antagonized by Mr2266. It is concluded that leumorphin has potent opioid activity and acts at the kappa receptor, like other opioid peptides derived from preproenkephalin B.     

Mode of antitumor action of recombinant human tumor necrosis factor on the sarcoma Meth A transplanted in the mouse

The mode of antitumor action of rHu-TNF was elucidated in BALB/c mice bearing Meth A fibrosarcoma 7 days after transplantation with respect to time course, dose-response relationships and selectivity of the effects. The maximal cytotoxic effect on tumor cells revealed by inhibition of DNA synthesis and maximal lesional effect on tumor vasculature revealed by change in blood pool-size in the tissue were detected at 30 min and I h after administration of rHu-TNF, respectively. The dose-response relationship between cytotoxic and tumoricidal effects of rHu-TNF was irrespective of administration route. ED₅₀s of these antitumor effects afteri.v. administration of rHu-TNF were about 50 times as high as ED₅₀s afteri.t. administration. ED₅₀ ofi.t. given rHu-TNF for vascular effect was about 20 times as high as that for cytotoxicity while ED₅₀ ofi.v. rHu-TNF for vascular effect was only 2–3 times as high as that for cytotoxicity. The whole body autoradiographies with [¹²⁵I] HSA giveni.v. to see the blood influx into tumor tissue and [¹⁴C]thymidine given i.v. to see DNA synthesis in the whole body after administration of rHu-TNF revealed that the distribution of radioactivity was markedly changed in the tumor alone without any detectable change in other whole body tissues.In conclusion, thein vivo antitumor effect of rHu-TNF giveni.t. ori.v., appears to be exerted through the direct action on Meth A sarcoma rather than indirectly on tumor vasculature. Under present conditions, the effect of rHu-TNF in the whole body tissues seems rather selective on cells and vasculature of the tumor.     

Enterobacter kobei sp. nov., a new species of the family Enterobacteriaceae resembling Enterobacter cloacae

The name Enterobacter kobei sp. nov. is proposed for a group of organisms referred to as NIH Group 21 at the National Institute of Health, Tokyo. The members of this species are Gram-negative, motile rods conforming to the definition of the family Enterobacteriaceae. The DNA relatedness of 23 strains of NIH Group 21 to the representative proposed as the type strain of this species averaged 82% at 70°C, whereas the relatedness to other species within the family Enterobacteriaceae was less than 42%. Because the phenotypic resemblance to Enterobacter cloacae is very close and the DNA relatedness (12–42%) is closer to species of the genus Enterobacter than to other species of the family, the members of NIH Group 21 were placed in the genus Enterobacter. Close phenotypic and genetic relationships were also found between NIH Group 21 and a member of a group of organisms referred to as Enteric Group 69 at the Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, USA. It is suggested that the latter could be regarded as a subspecific rank of E. kobei, though this is subject to study of further strains. The majority of strains of E. kobei were isolated from clinical specimens. A culture of the type strain (NIH 1485-79) has been deposited in the Japan Collection of Microorganisms as JCM 8580. Received: 22 March 1996 / Accepted: 19 April 1996     

Analysis of the biosynthetic process of cellulose and curdlan using C-labeled glucoses

In order to elucidate the biosynthetic process of cellulose and curdlan, ¹³C-labeled polysaccharides were biosynthesized by Acetobacter xylinum (IFO 13693) and Agrobacterium sp. (ATCC 31749), from culture media containing -(1-¹³C)glucose, -(2-¹³C)glucose, -(4-¹³C)glucose, or -(6-¹³C)glucose as the carbon source, and their structures were determined by ¹³C NMR spectroscopy. The labeling was mainly found in the original position, indicating direct polymerization of introduced glucoses. In addition, the transfer of labeling from C-2 to C-1, C-3 and C-5, from C-4 to C-1, C-2 and C-3, and from C-6 to C-1 was found in celluloses. In curdlan, the transfer of labeling from C-1 to C-3, from C-2 to C-1 and C-3, from C-4 to C-1, C-2 and C-3, and from C-6 to C-1 and C-3 was observed. From analysis of this labeling, the biosynthetic process of cellulose and curdlan was explained as involving six routes. The percentages of each route via which cellulose or curdlan is biosynthesized were estimated for upper (C-1 to C-3) and lower portions (C-4 to C-6) of glucosidic units in the polysaccharides. It is noted that very few polysaccharides are formed via the Embden-Meyerhof pathway. The lower half (C-4 to C-6) structure of introduced glucoses is well preserved in the polysaccharides.