Transport of prepro-albumin into inverted vesicles prepared from the inner membrane of rat liver mitochondria.

When inverted vesicles prepared from the inner membrane of rat liver mitochondria were incubated with prepro-rat serum albumin, considerable amounts of prepro-albumin and pro-albumin were recovered with the inverted vesicles re-isolated by centrifugation. Pro-albumin was resistant to trypsin, but prepro-albumin was completely digested by trypsin, indicating that prepro-albumin was transported into the vesicles and concomitantly converted to pro-albumin. This transport process required ATP, but not a membrane potential. These results suggest that some export machinery for a protein having an amino acid sequence in its N-terminal portion similar to the signal sequence of secretory protein exists in the inner mitochondrial membrane.

Peroxidase-catalyzed generation of catechin oligomers that inhibit glucosyltransferase from Streptococcus sobrinus.

Oolong tea extract (OTE) and the purified polymeric polyphenols from OTE have been found to inhibit glucosyltransferase (GTase) of mutans streptococci. In view of the partial fermentation characteristic of oolong tea, we describe here an in vitro model reaction system to produce partially fermented products of D-(+)-catechin or green tea extract (GTE) using horseradish peroxidase. A dimeric catechin molecule was identified as dehydro-dicatechin A by instrumental analyses. The molecular size of some oligomeric catechins was estimated by the elution profile with HPLC. These catechin oligomers markedly inhibited GTase from Streptococcus sobrinus 6715. As the degree of polymerization of catechin or GTE increased, GTase was inhibited more effectively. These results suggest that polymeric polyphenols found in OTE are synthesized by partial fermentation due to oxidases/peroxidases present in tea leaves.

Incorporation into human enamel of fluoride slowly released from a sealant in vivo.

Fluoride incorporation into human enamel from an experimental sealant resin in vivo was investigated. The sealant consisted of a newly synthesized methacryloyl fluoride-methyl methacrylate (MF-MMA) copolymer resin, which contains acidic fluoride covalently bonded to carbonyl groups and releases fluoride ions slowly by hydrolysis in an aqueous environment. This experimental sealant was applied to the enamel of permanent pre-molars and the control sealant without MF-MMA copolymer to that of the contralateral teeth. Fluoride concentration was determined by an enamel biopsy procedure with acid-etching four weeks after the sealant application. As much as 3500 ppm fluoride was found to be deposited at 10 microns depth in the enamel under the MF-MMA copolymer sealant. The increase in fluoride concentration was significant even at 60 microns. Of the fluoride incorporated into the enamel, from 70 to 80% was present as a tightly bound form. This resin sealant is expected to protect the enamel from caries attack even after detachment of the sealant.

Efficacy of double-filtration plasmapheretic cross-circulation with a high-permeability membrane using canine harvested liver in porcine fulminant hepatic failure model.

INTRODUCTION: The use of bioartificial liver devices requires. A sufficient liver cell mass to provide adequate metabolic support, reduction of xenogeneic immune reactions, and avoidance of viral transmission. We have developed a plasmapheresis system using a semipermeable membrane combined with canine whole liver perfusion (PMCWLP). In this study, we investigated the efficacy of our system in a porcine fulminant hepatic failure (FHF) model. METHODS: The porcine FHF model was established by intraportal administration of alpha-amanitin (0.1 mg/kg) and lipopolysaccharide (1 microg/kg). Nine hours after drug injection, xenogenic perfusion treatment was performed twice within 6 hours (n = 5). As the plasmapheresis device, we used a hollow-fiber module with cellulose diacetate porous fibers (pore size, 0.05 microm, surface area, 2 m2). The canine whole liver was perfused with modified Krebs solution, which is commonly used in many laboratories, containing albumin (2 g/dL) and glucose (300 mg/dL). Control pigs (n = 10), had the circuit not connected to the whole canine liver. RESULTS: The survival of FHF pigs was significantly increased by the treatment (58.9 +/- 21.8 hour) compared with the controls (22.3 +/- 8.1 hour). Mean blood ammonia levels and intracranial pressure during treatment were significantly lower compared with control groups. CONCLUSION: Treatment of FHF pigs with the system significantly increased survival time, suggesting that this method may have applications as a clinical liver assist device.

Network structures and thermal properties of polyurethane films prepared from liquefied wood.

Polyurethane (PU) films were prepared by solution-casting after co-polymerization of liquefied woods (LWs) and polymeric methylene diphenylene diisocyanate (PMDI). The resulting PU films had various [NCO]/[OH] ratios ranging from 0.6 to 1.4 and contained 5.0-16.8% dissolved woody components at the [NCO]/[OH] ratio of 1.0. The crosslink densities of the films with [NCO]/[OH] ratios of 0.6-1.4 increased remarkably with increasing [NCO]/[OH] ratio. Similarly, there were large increases in glass transition temperatures (Tg). These characteristics could be attributed to effective incorporation of PMDI into the LW. The crosslink densities and Tg of the PU films prepared at the [NCO]/[OH] ratio of 1.0 increased because the amounts of dissolved woody components in the films increased. It is concluded that the dissolved woody components acted as crosslinking points in PU network formations. The thermal degradation of the PU films at an [NCO]/[OH] ratio of more than 0.8 or with more than 10.6% dissolved wood started above 262 degrees C under an N2 atmosphere. The thermostability was lost at low crosslink density or with large amount of co-polymerized glycerol structures in the PU networks.

[Bacteriological examination of infections in the field of oral surgery].

Etiology of bacterial infections in the field of oral surgery was studied. A total of 270 samples collected from patients with encapsulated abscess in their oral cavities was examined and bacteria were isolated from the 244 samples (90.4%). The following results were found; 1) Organisms more than one from one sample were frequently isolated from cases with parodontitis, pericoronitis and gnathitis. Isolation of anaerobic bacteria was common (54.2%). 2) Streptococcus milleri and Streptococcus sanguis and Capnocytophaga species were the most common isolates among aerobic gram-positive and gram-negative bacteria, respectively. 3) Peptostreptococcus micros and Eubacterium lentum were most frequent isolates among gram-negative anaerobic bacteria. Among gram-negative bacteria, Oral Group Bacteroides, especially Bacteroides gingivalis, Bacteroides intermedius, Bacteroides buccae and Bacteroides oralis were most prominent. 4) Isolation frequency of bacteria (both species and strains) was high from samples obtained from patients before antibiotic chemotherapy. 5) Most strains were sensitive to Midecamycin acetate and Josamycin. Minimum inhibitory concentration of 80% isolates (MIC80) against these antibiotics was 0.39 microgram/ml.

Study of anionic sites on the mesangium in aminonucleoside nephrosis.

In recent years, various reports have appeared concerning anionic sites in glomerular lesions. However, no detailed results for anionic sites in the mesangium have been reported. The authors therefore prepared nephrotic rats by the administration of puromycin aminonucleoside (PA) and investigated the anionic sites in various mesangial regions, using polyethyleneimine (PEI) as a cationic probe. In the mesangium of the control group as well as the experimental groups, PEI particles were most numerous in the subendothelial regions, followed by the central region and paramesangial region, in that order. In the group treated with PA, the numbers of PEI particles in each mesangial region decreased as compared with those in the control group. Among the three mesangial regions considered, this decrease was most pronounced in the paramesangial region. In the group which received elastase, no significant decrease in numbers of PEI particles was observed in subgroups I and II, indicating maintenance of the anionic sites. The results obtained suggested that regional investigations of the mesangial matrix may be of considerable significance for elucidating the etiologic factors in glomerular sclerosis, and that negative charge impairment in the mesangial matrix plays an important role in the development of glomerular sclerotic lesions.

A ten-year experience and follow-up of three hundred patients fitted with the Biomet/Lorenz Microfixation TMJ replacement system.

The purpose of this paper is to present the postoperative results obtained after full temporomandibular joint (TMJ) reconstruction employing the Biomet/Lorenz Microfixation TMJ replacement system (Jacksonville, FL, USA) in 300 patients (201 unilateral, 99 bilateral). Objective data (maximum inter-incisal opening; MIO) and subjective data (function and speech, diet, and pain) were collected preoperatively and at postoperative evaluations performed over a 10-year period (mean 3.5, standard deviation 2.1 years). The MIO measures were obtained using a calliper rule. Subjective data were evaluated using a visual analogue scale with scores ranging from 0 to 5 for each variable. The results were analyzed with the paired t-test (two-sided, α=5%). Each patient showed significant improvements for all of the variables at evaluation on postoperative day 7. The results for MIO, function and speech, and diet, showed improvements at each postoperative evaluation over a maximum of 3 years, with stabilization of the results from the fourth year. Complaints of pain decreased considerably up to the 1-month postoperative evaluation, and no patient reported severe pain at 6 months after surgery. The results presented show that the reconstruction of the TMJ through the installation of the Biomet/Lorenz system prosthesis is a safe and effective option for proper reestablishment of the joint and stomatognathic system function; significant long-term improvements in mandibular range of motion are promoted and pain levels decrease.

Isolation of mesenchymal stem cells from bone marrow wastes of spinal fusion procedure (TLIF) for low back pain patients and preparation of bone dusts for transplantable autologous bone graft with a serum glue.

Low back pain and subsequent disabilities are common. A lumbar spinal fusion procedure is an effective treatment with autologous bone grafts, but harvesting the bone from the iliac crest is associated with risks of complications. New treatments using stem cells together with osteoconductive and otesoinductive materials have made the procedure safer, but the inconsistency of the amount of stem cells harvested from bone marrow aspirate still remains to be solved. This study reports that the bone dusts, usually discarded as surgical wastes during transforaminal lumbar interbody fusion procedure (TLIF procedure), yielded cells which had the characteristics of mesenchymal stem cells (MSCs) in vitro. The cells were positive for the MSC markers and were able to differentiate in osteogenic and adipogenic directions. The cells grew robustly in an osteoconductive material, Bolheal (serum glue), and also proliferated well in culture medium supplemented with autologous serum. Therefore, the bone dust is a good candidate for the alternative source of stem cells other than bone marrow aspirate to increase the safety of the TLIF procedure.

Effects of size of cellulose granules on dough rheology, microscopy, and breadmaking properties.

Breadmaking was performed with cellulose-blended wheat flour. Cellulose granules (7 types) of various sizes (diameter) were prepared by kneading. With increase of the blend percent of the cellulose samples from 10% to 20%, breadmaking properties such as bread height and specific volume (SV) gradually decreased in every sample; however, the decreasing levels of the properties in 7 types of various sizes varied. The decrease of bread height and SV was associated with the size of the cellulose granule. It was observed at both 10% and 20% blends that the same bread height and SV as for bread baked with only wheat flour could be obtained when the diameter of cellulose granule was above 154 mum in cellulose/wheat flour breadmaking, while they gradually decreased with granules below 154 mum. When the largest cellulose granules were mechanically ground to make smaller ones, the bread height and SV decreased with increasing grinding time. It was ascertained that the size of the cellulose granule was important for breadmaking properties. Cellulose-blended wheat flour was subjected to mixograph tests. When cellulose granules above 154-mum dia were blended with wheat flour, the profile of the mixogram was almost the same as that for wheat flour; that is, the profile had a short mixing requirement and showed a viscous gluten matrix. However, when cellulose granules below 81-mum dia were blended, a different curve showing a nonviscous dough due to breakdown of the gluten protein was observed, as ascertained by microscopy. Farmograph test showed that the amount of the released gas from cellulose-blended bread dough increased with decrease of the size of the cellulose granule due to breakdown of the gluten protein.