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PubMed2006

Long-term safety and efficacy of poly-L-lactic acid in the treatment of HIV-related facial lipoatrophy.

OBJECTIVE: We evaluated the long-term safety and efficacy of injectable poly-L-lactic acid (PLLA) for the correction of facial lipoatrophy. METHODS: This was a randomized, open-label, comparative, single-centre study of injected PLLA in patients with HIV-related facial lipoatrophy. Thirty subjects were randomized to immediate or delayed PLLA treatments, administered as three sets of bilateral injections, 2 weeks apart, into the deep dermis above the buccal fat pad. Week 24 results have been published previously (Moyle et al, HIV Medicine 2004, Vol. 5, pp. 82-87). Long-term efficacy was assessed at a recall visit using visual analogue scales (VASs) to record patient satisfaction, and by the Hospital Anxiety and Depression Scale (HADS). Patients also reported any adverse events (AEs) during the treatment period and at the recall visit. RESULTS: Twenty-seven patients returned for the recall visit, a minimum of 18 months post final study treatment. Fourteen of these patients were excluded from the recall visit because of additional treatment with PLLA. Improvements in VAS scores for facial appearance were sustained from baseline to the recall visit in both randomization groups (P<0.05 and P<0.001). Trends in improvement in HADS scores were also noted, with patients in the delayed group experiencing significant improvements in depressive symptoms (P<0.05). One case of injection-site induration and nine cases of injection-site nodules were noted at the recall visit, none of which was described as serious or severe. CONCLUSIONS: Physical and psychological benefits of PLLA are sustained over at least 18 months. Delayed AEs include mild nodularity at the treatment site.

Adult↗
PubMed2004

Utility of base deficit, lactic acid, microalbuminuria, and C-reactive protein in the early detection of complications in the immediate postoperative evolution.

OBJECTIVE: To determine the utility of biochemical parameters such as lactic acid (LA), C-reactive protein (CRP), microalbuminuria (MAU), and base deficit (BD) as early markers of complications in the immediate postoperative evolution of elective open gastrointestinal surgeries. DESIGN AND METHODS: Sixty-two patients subject to elective open gastrointestinal surgery were evaluated during a period of 22 months. RESULTS: From the initial 62 patients, 2 were excluded, 29 (48.3%) evolved without complications, and 31 (51.6%) with complications. It was observed that the most significant areas under the ROC curve corresponded to BD in the preoperative period, LA on the first day, and CRP from the second to the seventh day after surgery. MAU was not a discriminating parameter since it did not reach a significant area under the curve (AUC) at any time. CONCLUSIONS: The biochemical markers that best relate to the presence of complications are BD in the preoperative period, LA on the first day, and CRP from the second to the seventh day after surgery.

Acid-Base Imbalance↗
PubMed1992

Classification of ropy slime-producing lactic acid bacteria based on DNA-DNA homology, and identification of Lactobacillus sake and Leuconostoc amelibiosum as dominant spoilage organisms in meat products.

The classification of lactic acid bacteria able to cause ropy slime on vacuum-packed cooked meat products was carried out based on DNA-DNA homology. The ropy slime-producing lactobacilli were identified as strains of Lactobacillus sake and the ropy slime-producing leuconostocs, such as Leuconostoc amelibiosum and Leuconostoc mesenteroides.

DNA, Bacterial↗
PubMed2002

The lactic acid bacteria: a literature survey.

The purpose of this review article on the lactic acid bacteria grew from an early curiosity and a desire to convey and impart the broad scope of literary information on their functions as starter cultures, in the manufacture of fermentation products such as dairy products and alcoholic beverages, as well as their contribution to better health. This review article is an attempt to empower the reader and to circumvent the difficult task in acquiring and elucidating a large body of information. The intent is to familiarize the reader with the various lactic species, their habitat or source, associated food, physiological characteristics, colonial morphology, biochemical characteristics, culture media (enrichment, nonselective, and selective), classic description, and taxonomy. This review provides information on Lactobacillus, Lactococcus, Leuconostoc, Pediococcus, Carnobacterium, and Enterococcus. Trends are presented, such as the use of nisin to extend food shelf-life and the current research premise that Probiotic strains may alter the intestinal flora and thus prevent intestinal wall penetration by pathogens.

Culture Media↗
PubMed1996

Photodynamic therapy of tumours with hexadecafluoro zinc phthalocynine formulated in PEG-coated poly(lactic acid) nanoparticles.

Hexadecafluoro zinc phthalocyanine (ZnPcF16), a second-generation sensitizer for the photodynamic therapy (PDT) of cancer, was formulated in polyethylene-glycol-coated poly(lactic acid) nanoparticles (PEG-coated PLA-NP) and tested in EMT-6 tumour-bearing mice for its photodynamic activity. The tumour response was compared to that induced by the same dye formulated as a Cremophor EL (CRM) emulsion. Formulation in the biodegradable NP improved PDT response of the tumour while providing prolonged tumour sensitivity towards PDT.

Animals↗
PubMed1995

Controlled delivery of taxol from microspheres composed of a blend of ethylene-vinyl acetate copolymer and poly (d,l-lactic acid).

'Large' (30-100 microns) and 'small' (10-30 microns) size range taxol-loaded microspheres composed of a blend of biodegradable poly (d,l-lactic acid) (PLA) polymer and nondegradable ethylene-vinyl acetate (EVA) copolymer were prepared using the solvent evaporation method. Encapsulation efficiencies were between 95-100% for taxol in 50:50 EVA:PLA blend microspheres. Between 10-13% of the total taxol content of the microspheres (0.6% w/v taxol loading) was released in 50 days. Using the chick chorioallantoic membrane (CAM) model, the taxol microspheres released sufficient taxol to produce vascular regression and inhibition of angiogenesis. This taxol-loaded microsphere formulation may have potential for the targeted delivery of taxol to a tumor via arterial chemoembolization.

Animals↗
PubMed2002

Release of propranolol and diclofenac from low Mw DL-poly(lactic acid).

The controlled release of two drugs, i.e. the sodium salt of diclofenac and propranolol was studied, by using low molecular weight D,L-Poly(lactic acid) as a matrix. Tablets of the above polymer containing those drugs were immersed into buffers with various pH values and delivery was recorded as a function of time, via UV-spectroscopy. The results showed that the polymer is appropriate for such biomedical applications, as generally, it ensures complete drug delivery within 45-60 days, which is acceptable for most cases. On the other hand, the release rate depends on many parameters including the interactions among drug, matrix and the surrounding liquid, which adds complexity to the process and requires careful investigation for proper design of a controlled release system.

Biocompatible Materials↗
PubMedDate not supplied

Annealing and melting behavior of poly(l-lactic acid) single crystals as revealed by in situ atomic force microscopy.

In situ annealing and melting of folded-chain single crystals of poly(l-lactic acid) (PLLA) was examined by temperature-controlled atomic force microscopy (AFM). Prominent changes in the crystal appearance during annealing could be followed in real time by the AFM at temperatures above the original crystallization temperature. Thickening of the crystal edges could be occasionally observed, and this indicates that the crystal edges are less perfect than the central, well-ordered regions. At higher annealing temperatures, melting of the unthickened part started. The melting of the unthickened region progressed from the boundaries of the thickened portion normal to the growth face, rather than to the folding surfaces. In addition, it is suggested that melting also initiates at defective or distorted sites in the crystal as revealed by transmission electron microscopy (TEM) and AFM.

Biocompatible Materials↗
PubMedDate not supplied

[Hygienic characterization of lactic acid bacteria products prepared by using hydrolysates of raw milk and soya bean materials].

The paper reflects the results of a comparative study of preparations of lactic acid bacteria (LAB), which are based on the hydrolysates of raw milk and soya bean materials, by using methods to determine the organoleptic and physicochemical properties, microbiological characteristics including the titer of microbial cells per ml of the preparation and the presence/absence of representatives of sanitary significant groups of microorganisms, the persistent properties of microorganisms. By summarizing the findings, it can be stated that it is possible to use a raw soya-bean hydrolysate-based nutrient medium to cultivate technical LAB strains with the compliance of the toxicological and microbiological parameters of the prepared preparations with the current sanitary standards. The LAB preparations grown on the hydrolysate-soya-bean medium have been protected with the patents of Russia. Their biological properties are highly competitive with those and, in some cases, superior to hydrolysate-milk medium-based preparations. This presents in their adhesive potential and in the formation of more pronounced antagonistic properties against opportunistic microorganisms.

Animals↗
PubMed2003

Characterization of sourdough lactic acid bacteria based on genotypic and cell-wall protein analyses.

AIMS: To evaluate the effectiveness of two independent methods in differentiating a large population of lactic acid bacteria (LAB) isolated from wheat flours and sourdoughs and to correlate eventual differences/similarities among strains with their geographical origin and/or process parameters. METHODS AND RESULTS: One hundred fifty strains belonging to Lactobacillus spp. and Weissella spp., plus eight type strains, one for each species, and two unidentified isolates, were characterized by randomly amplified polymorphic DNA (RAPD) and SDS-PAGE of cell-wall proteins. The RAPD analysis separated the eight type strains but did not always assign all the strains of a species to the same group, while SDS-PAGE cell-wall protein profiles were species-specific. Frequently, strains isolated from sourdoughs of the same geographical origin or produced by similar raw material/process parameters showed similar RAPD and/or cell-wall profiles. CONCLUSIONS: The combined use of the RAPD and cell-wall protein analysis represents a useful tool to classify large adventitious microbial populations and to discriminate the diversity of the strains. SIGNIFICANCE AND IMPACT OF THE STUDY: This study represents a typing of a large collection of flour/sourdough LAB and provides evidence of the advantage of using two independent methods in the classification and traceability of microorganisms.

Bacterial Proteins↗
PubMed2004

Hetero-stereocomplexes of D-poly(lactic acid) and the LHRH analogue leuprolide. Application in controlled release.

Reversible hetero-stereoselective complexes were obtained by mixing acetonitrile solutions of enantiomeric D-poly(lactic acid) (d-PLA) and leuprolide, an L-configured nonapeptide LHRH analogue. The complex spontaneously aggregated and precipitated in high yields (95%) from acetonitrile solutions, forming uniform, porous microparticles with a mean unweighed particle size of 1.7 microm. The complexation of L-configured peptide occurred only with D-PLA, and not with L-PLA or racemic D,L-PLA. Various factors affecting the release pattern of leuprolide from the hetero-stereocomplexes were investigated. Complexes with D-PLA of low molecular weight (< 10,000 Da) displayed lower release rates of leuprolide than high molecular weight D-PLA (> 50,000 Da). Changing the leuprolide: D-PLA ratio from 1:50 to 1:10 (w/w) in the stereocomplex, resulted in a faster release of leuprolide. Similarly, the release rate of leuprolide was twice as fast when adding poly(ethylene glycol) to the acetonitrile complexation solution. Leuprolide was released from most of the formulations in a first order pattern, with only a small burst release during the first 24 h. Addition of water to the complexation solution significantly increased the initial release of the peptide. Low testosterone levels for over 25 days were observed in an in vivo release study of leuprolide from a hetero-stereocomplex formulation, monitoring testosterone levels in the blood of rats after sub cutaneous injection.

Animals↗
PubMed2003

The potential of dairy lactic acid bacteria to metabolise amino acids via non-transaminating reactions and endogenous transamination.

The metabolism of amino acids by 22 starter and 49 non-starter lactic acid bacteria (LAB) was studied in a system consisting of amino acids and non-growing cells without added amino acceptors such as alpha-ketoglutarate. There were significant inter- and intra-species differences in the metabolism of amino acids. Some amino acids such as alanine, arginine, aspartate, serine and branched-chain amino acids (leucine, isoleucine and valine) were utilised, whereas other amino acids such as glycine, ornithine and citrulline were produced. Alanine and aspartate were utilised by some LAB and accumulated during the incubation of other LAB. Arginine was degraded not only by Lactococcus lactis subsp. lactis (the lactococcal subspecies known to catabolise arginine), but also by pediococci, heterofermentative lactobacilli (Lactobacillus brevis and Lb. fermentum) and some unidentified homofermentative lactobacilli. Serine was utilised predominantly by homofermentative Lb. paracasei subsp. paracasei, Lb. rhamnosus and Lb. plantarum. Of the LAB studied, Lb. brevis and Lb. fermentum were the most metabolically active, utilising alanine, arginine, aspartate, glutamate and branched-chain amino acids. Leuconostocs were the least metabolically active, showing little potential to metabolise amino acids. The formation of ammonia and acetate from amino acid metabolism varied both between species and between strains within species. These findings suggest that the potential of LAB for amino acid metabolism via non-transaminating reactions and endogenous transamination will impact both on the physiology of LAB and on cheese ripening, especially when transamination is rate-limiting in the absence of an exogenous amino acceptor such as alpha-ketoglutarate.

Amino Acids↗
PubMed2001

Comparison of two methods of encapsulation of an oligonucleotide into poly(D,L-lactic acid) particles.

The aim of this study was to compare two methods to encapsulate a 25-mer-phosphorothioate oligonucleotide (ODN) into poly(D,L-lactic acid) (PLA) particles. Antisense oligonucleotides belong to a new therapeutic class especially attractive for the treatment of cancers and viral diseases. The development of these new drugs suffers, however, from poor stability in biological media and very low cellular uptake. Polymeric particulate systems display interesting features for ODN delivery. ODN are highly hydrophilic and most encapsulation methods are inappropriate for such molecules. Using poly(D,L-lactide) polymer, two methods of encapsulation were compared. First, a double emulsion technique was used to prepare nano- and microparticles. Secondly, the ODN was combined with a quaternary ammonium, the cethyltrimethyl-ammonium bromide (CTAB), to enhance the hydrophobicity of the molecule before entrapment by the emulsification-diffusion method. Both methods led to the formation of individualized and spherical particles loaded with a significant amount of ODN. Similar entrapment efficiencies were obtained for the nanoparticles prepared by both methods (approx. 27% of the theoretical loading) whereas 45% of entrapment efficiency was observed for the microparticles. Seventy five percent of the ODN were released in 60 min with the particles prepared by the emulsification-diffusion method, whereas only 7% were released in 60 h when using the double emulsion method. A viability test on U-937 cells showed better survival rates with the particles prepared by the double emulsion technique. The results suggest that the location of the ODN in the polymeric matrix is affected by the encapsulation method. Particles containing CTAB appeared more toxic than the ones obtained by the double emulsion technique, however, these particles can still be used for antisense activity since high oligonucleotide loading can be achieved.

Diffusion↗
PubMed2001

Poly(lactic acid)-poly(ethylene glycol) nanoparticles as new carriers for the delivery of plasmid DNA.

The purpose of the present work was to produce and characterize poly(lactic acid)-poly(ethylene glycol) (PLA-PEG) nanoparticles (size lower than 300 nm) containing a high loading of plasmid DNA in a free form or co-encapsulated with either poly(vinyl alcohol) (PVA) or poly(vinylpyrrolidone) (PVP). The plasmid alone or with PVA or PVP was encapsulated by two different techniques: an optimized w/o/w emulsion-solvent evaporation technique as well as by a new w/o emulsion-solvent diffusion technique. Particle size, zeta potential, plasmid DNA loading and in vitro release were determined for the three plasmid-loaded formulations. The influence of the initial plasmid loadings (5, 10, 20 microg plasmid DNA/mg PLA-PEG) on those parameters was also investigated. The plasmid loaded into the nanoparticles and released in vitro was quantified by fluorimetry and the different molecular forms were identified by gel electrophoresis. PLA-PEG nanoparticles containing plasmid DNA in a free form or co-encapsulated with PVA or PVP were obtained in the range size of 150-300 nm and with a negative zeta potential, both parameters being affected by the preparation technique. Encapsulation efficiencies were high irrespective of the presence of PVA or PVP (60-90%) and were slightly affected by the preparation technique and by the initial loading. The final plasmid DNA loading in the nanoparticles was up to 10-12 microg plasmid DNA/mg polymer. Plasmid DNA release kinetics varied depending on the plasmid incorporation technique: nanoparticles prepared by the w/o diffusion technique released their content rapidly whereas those obtained by the w/o/w showed an initial burst followed by a slow release for at least 28 days. No significant influence of the plasmid DNA loading and of the co-encapsulation of PVP or PVA on the in vitro release rate was observed. In all cases the conversion of the supercoiled form to the open circular and linear forms was detected. In conclusion, plasmid DNA can be very efficiently encapsulated, either in a free form or in combination with PVP and PVA, into PLA-PEG nanoparticles. Additionally, depending on the processing conditions, these nanoparticles release plasmid DNA either very rapidly or in a controlled manner.

Chemical Phenomena↗
PubMed2003

Chondrocyte behaviors on poly-L-lactic acid (PLLA) membranes containing hydroxyl, amide or carboxyl groups.

Hydrophilic groups, i.e. hydroxyl (-OH), carboxyl (-COOH) or amide (-CONH(2)) were introduced onto the poly-L-lactic acid (PLLA) membrane surfaces via the photo-induced grafting copolymerization of the corresponding monomers, i.e. hydroxyethyl methacrylate, methacrylic acid or acrylamide, respectively. Chondrocyte culture was used to study the correlation between the cell behaviors and the hydrophilic functional groups. The results showed that the cytocompatibility of the PLLA membranes with hydroxyl or amide groups on the surface was greatly improved compared to that of the original PLLA membrane. However, the PLLA membrane with carboxyl groups on the surface had even worse cytocompatibility though possessed a similar hydrophilicity.

Animals↗
PubMed1988

Numerical taxonomy of psychrotrophic lactic acid bacteria from prepacked meat and meat products.

Ninety-four strains of lactic acid bacteria isolated from refrigerated, prepacked meat and meat products were together with 59 reference strains of Brochothrix, Lactobacillus, Leuconostoc, Pediococcus and Streptococcus phenotypically classified, using 96 unit characters. Data were examined using Simple Matching (SSM) or Jaccard coefficient (SJ), and unweighted pair group algorithm with arithmetic averages. Twenty-three clusters with two or more members were defined at the 84% SSM-similarity level which corresponded to the SJ-similarity level of 61%. Based on SSM, most field strains were included in nine clusters, and with three unsignificant exceptions these contained no reference strains. The field clusters were designated Carnobacterium piscicola (cluster 1; 5% of field isolates), Carnobacterium divergens (cluster 2; 9% of field isolates), Leuconostoc (cluster 9; 18% of field isolates) and Lactobacillus (cluster 4, 10, 11, 12, 13 and 14; together 60% of field isolates). The Lactobacillus clusters had many features in common with cluster II of Shaw & Harding (1984). Phenotypical characteristics of major clusters are given. The SSM and SJ based classifications basically coincided for the field strains; the exception was cluster 4 which now were split in two parts. Fourteen clusters were made up of mainly reference strains (SSM). Most of them included more than one type strain on species level; exceptions were Brochothrix thermosphacta (cluster 3), Lactobacillus salivarius (cluster 17) and Leuconostoc mesenteroides (cluster 18). Several rearrangements were seen amongst the clusters of the reference strains when SJ, instead of SSM, was used for clustering.

Food Microbiology↗