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L Gram

Publications and source records attributed to L Gram.

At least 19 recordsLinked to original sources
PubMed1998

Evaluation of the role of Carnobacterium piscicola in spoilage of vacuum- and modified-atmosphere-packed cold-smoked salmon stored at 5 degrees C.

The microflora on spoiled cold-smoked salmon often consists of a mixture of lactic acid bacteria (LAB) and Gram-negative bacteria. To elucidate the role of the different groups, a storage trial was carried out in which nisin and CO2 were used for the selective inhibition of the two bacterial groups. The shelf-life of vacuum-packed cold-smoked salmon, recorded by sensory evaluation, was four weeks at 5 degrees C and the microflora was composed of LAB (10(6)-10(7) cfu/g) with an associate Gram-negative flora in varying levels (10(5)-10(7) cfu/g). The addition of nisin and/or a CO2-atmosphere increased the shelf-life to five or six weeks and limited the level of LAB to about 10(4)-10(6), 10(3)-10(6) and 10(2)-10(4) cfu/g, respectively. CO2-atmosphere +/- nisin inhibited the growth of Gram-negative bacteria, whereas nisin had no effect on these in vacuum packages. The Gram-negative flora on vacuum-packed salmon was dominated by a Vibrio sp., resembling V. marinus, Enterobacteriaceae (Enterobacter agglomerans, Serratia liquefaciens and Rahnella aquatilis) and occasionally Aeromonas hydrophila. Irrespective of the addition of nisin and/or CO2-atmosphere, the LAB microflora was dominated by Carnobacterium piscicola, which was found to account for 87% of the 255 LAB isolates characterized. Whole-cell-protein patterns analysed by SDS-PAGE confirmed the Carnobacterium species identification. The spoilage potential of C. piscicola isolates was further studied by inoculation of approx. 10(6) cfu/g in cold-smoked salmon stored at 5 degrees C. The salmon did not spoil within 4 weeks of storage in vacuum- or CO2-atmosphere, and it is concluded that despite high levels (> 10(7) cfu/g) of C. piscicola, sensory rejection was caused by autolytic changes. This was supported by the development of soft texture and sour, rancid and bitter off-flavours at the point of spoilage, irrespective of the length of shelf-life and low or high total counts of LAB and Gram-negative bacteria.

Animals↗
PubMed1998

Antiepileptic drugs as a cause of worsening seizures.

PURPOSE: Although the paradoxical ability of antiepileptic drugs (AEDs) to increase seizure activity has been recognized for decades, the underlying mechanisms are poorly understood and few systematic studies have addressed this problem. This article is intended to provide a critical review of available literature on this topic. METHODS: Information was collected by means of computerized literature searches, screening of journals and textbooks, and consultation with colleagues. Mechanisms which potentially might precipitate underlying drug-induced exacerbation of seizures were considered based on available pharmacologic and clinical knowledge. RESULTS: The reviewed information suggests that a paradoxical increase in seizure frequency may occur as a result of at least two separate mechanisms. The first appears to involve a nonspecific manifestation of drug intoxication; seizure-worsening in this context is usually reversible by dosage reduction or elimination of unnecessary polypharmacy. Conversely, the other mechanism may involve a distinct adverse primary action of the drug in specific seizure types or in syndromic forms. Carabamazepine, in particular, has been reported to precipitate or exacerbate a variety of seizures, most notably absence, atonic, or myoclonic seizures in patients with generalized epilepsies characterized by bursts of diffuse and bilaterally synchronous spike-and-wave EEG activity. Phenytoin and vigabatrin also have been implicated in worsening of seizures, particularly generalized seizures, whereas gabapentin has been associated repeatedly with precipitation of myoclonic jerks. Benzodiazepines occasionally have been reported to precipitate tonic seizures, especially when given intravenously to control other seizure types in patients with Lennox-Gastaut syndrome. Seizure deterioration has been reported also with other drugs; though in most cases evidence is still insufficient for meaningful conclusions to be drawn. CONCLUSIONS: Drug-induced exacerbation of seizures is a serious and common clinical problem that is often unrecognized or overlooked by the treating physician. Its occurrence appears to be related to three possible causes: an incorrect diagnosis of seizure type or syndromic form, lack of knowledge about certain drugs that are contraindicated in specific types of epilepsies, or to prescription of excessive drug dosages and drug combinations. Further studies are required to evaluate the prevalence of this phenomenon of drug-induced exacerbation of seizures, to investigate its mechanisms in greater detail and to characterize additional prognostic factors that may be used for early identification of patients at risk.

Acute Disease↗
PubMed1998

Pregnancy and epilepsy: a retrospective study of 151 pregnancies.

OBJECTIVE: We studied the course of pregnancy in women with epilepsy to identify possible risk factors which might complicate the epilepsies and pregnancy outcomes. MATERIAL AND METHODS: Data were collected retrospectively from the records of 151 pregnancies in 124 women with epilepsy from 1978-1992. Epilepsy variables were compared with that of non-pregnant women with epilepsy matched for age. Obstetric and neonatal variables were compared with those of all deliveries in the same unit from 1979-1992 (n=38,983). RESULTS: Pregnancy among patients with epilepsy was more likely to occur in women with relatively mild epilepsy. In 12% of the pregnancies, the women were untreated while 71% were on monotherapy. Twenty-one percent had increased seizure frequency during the pregnancy. Perinatal deaths among newborns of epileptic mothers (1.3%) was more frequent but not significantly increased compared to the background population of 0.5% (95% CI 0.2-4.7). A total of 5.3% had congenital malformations compared to 1.5% in the controls (95% CI 2.3-10.3). No neural tube defects were observed. Maternal treatment with phenytoin was significantly related to the occurrence of congenital malformations, P=0.04. CONCLUSIONS: Most women with epilepsy have an uncomplicated pregnancy and normal healthy offsprings. Maternal treatment with phenytoin might be associated with congenital malformations. No other risk factors could be identified.

Abnormalities, Drug-Induced↗
PubMed1997

Inhibition of Listeria monocytogenes on cold-smoked salmon by nisin and carbon dioxide atmosphere.

The bacteriostatic and bacteriocidal effect of nisin in combination with carbon dioxide, NaCl and low temperature on the survival of Listeria monocytogenes was investigated in in vitro model studies and in trials with cold-smoked salmon. Addition of nisin caused various degrees of inhibition and sometimes death of L. monocytogenes in model experiments performed at 10 degrees C. The antilisterial effect of nisin was improved in the presence of 100% CO2 and increasing NaCl concentrations (0.5 to 5.0% w/v). Minimal bactericidal concentrations (MBC) of nisin varied from 30 to more than 500 IU/ml. The most pronounced effect of nisin was found when 10(2) cfu/ml was grown in media with 5.0% NaCl and incubated in CO2 atmosphere (MBC = 30 IU/ml). The bactericidal effect of nisin was reduced in air and vacuum, and did not increase systematically with increasing NaCl concentrations. In general, nisin concentration < or = 50 IU/ml resulted in the survival and growth of L. monocytogenes in all combinations with other preservatives (NaCl, CO2). Addition of nisin (500 or 1000 IU/g) to cold-smoked salmon inoculated with L. monocytogenes and stored at 5 degrees C delayed, but did not prevent growth of L. monocytogenes in vacuum-packs. Numbers of L. monocytogenes increased to 10(8) cfu/g in vacuum packed cold-smoked salmon in 8 days, whereas CO2 packing of cold-smoked salmon resulted in an 8-day lag phase of L. monocytogenes, with numbers eventually reaching 10(6) cfu/g in 27 days. Addition of nisin to CO2 packed cold-smoked salmon resulted in a 1 to 2 log reduction of L. monocytogenes followed by a lag phase of 8 and 20 days in salmon with 500 and 1000 IU nisin/g, respectively. The levels of L. monocytogenes remained below 10(3) cfu/g during 27 days of storage at both concentrations of nisin.

Animals↗
PubMed1997

Protamine-induced permeabilization of cell envelopes of gram-positive and gram-negative bacteria.

The inhibitory effect of the cationic peptide protamine on Listeria monocytogenes, Escherichia coli, and Shewanella putrefaciens has been studied in detail. The addition of protamine (10 to 1,000 micrograms/ml) resulted in inhibition of oxygen consumption after less than 1 min and loss of intracellular carboxyfluorescein and ATP after 2 to 5 min. Maximum antibacterial activity was reached at alkaline pH and in the absence of divalent cations. The efficient permeabilization of cell envelopes of both gram-positive and gram-negative bacteria suggests that protamine causes a general disruption of the cell envelope, leading to a rapid and nonspecific efflux of low- and high-molecular-weight compounds.

Adenosine Triphosphate↗
PubMed1997

Differentiation of Shewanella putrefaciens and Shewanella alga on the basis of whole-cell protein profiles, ribotyping, phenotypic characterization, and 16S rRNA gene sequence analysis.

Seventy-six presumed Shewanella putrefaciens isolates from fish, oil drillings, and clinical specimens, the type strain of Shewanella putrefaciens (ATCC 8071), the type strain of Shewanella alga (IAM 14159), and the type strain of Shewanella hanedai (ATCC 33224) were compared by several typing methods. Numerical analysis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of whole-cell protein and ribotyping patterns showed that the strains were separated into two distinct clusters with 56% +/- 10% and 40% +/- 14% similarity for whole-cell protein profiling and ribotyping, respectively. One cluster consisted of 26 isolates with 52 to 55 mol% G + C and included 15 human isolates, mostly clinical specimens, 8 isolates from marine waters, and the type strain of S. alga. This homogeneous cluster of mesophilic, halotolerant strains was by all analyses identical to the recently defined species S. alga (U. Simidu et al., Int. J. Syst. Bacteriol, 40:331-336, 1990). Fifty-two typically psychrotolerant strains formed the other, more heterogeneous major cluster, with 43 to 47 mol% G + C. The type strain of S. putrefaciens was included in this group. The two groups were confirmed by 16S rRNA gene sequence analysis. It is concluded that the isolates must be considered two different species, S. alga and S. putrefaciens, and that most mesophilic isolates formerly identified as S. putrefaciens belong to S. alga. The ecological role and potential pathogenicity of S. alga can be evaluated only if the organism is correctly identified.

Animals↗
PubMed1997

Enzymatic removal and disinfection of bacterial biofilms.

Model biofilms of Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas fluorescens, and Pseudomonas aeruginosa were made on steel and polypropylene substrata. Plaque-resembling biofilms of Streptococcus mutans, Actinomyces viscosus, and Fusobacterium nucleatum were made on saliva-coated hydroxyapatite. The activity of enzymes against bacterial cells in biofilm was measured by fluorescence microscopy and an indirect conductance test in which evolution of carbon dioxide was measured. Glucose oxidase combined with lactoperoxidase was bactericidal against biofilm bacteria but did not remove the biofilm from the substrata. A complex mixture of polysaccharide-hydrolyzing enzymes was able to remove bacterial biofilm from steel and polypropylene substrata but did not have a significant bactericidal activity. Combining oxidoreductases with polysaccharide-hydrolyzing enzymes resulted in bactericidal activity as well as removal of the biofilm.

Bacteria↗
PubMed1996

[Epilepsy].

Explore the source record for details and available documents.

Anticonvulsants↗
PubMed1996

[Lamotrigine treatment of 92 patients with intractable epilepsy].

The efficacy of treatment with lamotrigine (LTG) was evaluated in 92 patients with refractory epileptic seizures (46 women and 46 men aged 14-80 years, median 32 years). Seventy-one patients had partial epilepsy and 21 had primary generalized epilepsy. Patients were treated from zero to four (most frequently two) other antiepileptic drugs (AEDs). Maintenance dose of LTG was 50-800 mg daily (median 300 mg). Fifteen percent of the patients became seizure-free (13% of patients with partial epilepsy, 24% with primary generalized epilepsy). Thirty-eight percent of patients experienced at least 50% reduction in seizure frequency. Twenty-six percent of patients had a significant increase in seizure frequency (the same percentage in the two groups). Adverse events were recorded in 61% of patients, but most symptoms disappeared after dose reduction in concomitant AEDs. LTG was discontinued in 22% of patients, either because of adverse events or lack of effect. We conclude, that LTG is effective in reducing seizure frequency in patients with therapyresistant primary generalized epilepsy or partial epilepsy. Toxicity appears to be limited.

Adolescent↗
PubMed1996

Microbiological spoilage of fish and fish products.

Spoilage of fresh and lightly preserved fish products is caused by microbial action. This paper reviews the current knowledge in terms of the microbiology of fish and fish products with particular emphasis on identification of specific spoilage bacteria and the qualitative and quantitative biochemical indicators of spoilage. Shewanella putrefaciens and Pseudomonas spp. are the specific spoilage bacteria of iced fresh fish regardless of the origin of the fish. Modified atmosphere stored marine fish from temperate waters are spoiled by the CO2 resistant Photobacterium phosphoreum whereas Gram-positive bacteria are likely spoilers of CO2 packed fish from fresh or tropical waters. Fish products with high salt contents may spoil due to growth of halophilic bacteria (salted fish) or growth of anaerobic bacteria and yeasts (barrel salted fish). Whilst the spoilage of fresh and highly salted fish is well understood, much less is known about spoilage of lightly preserved fish products. It is concluded that the spoilage is probably caused by lactic acid bacteria, certain psychotrophic Enterobacteriaceae and/or Photobacterium phosphoreum. However, more work is needed in this area.

Animals↗
PubMed1996

Vigabatrin withdrawal randomized study in children.

Controlled studies with new antiepileptic drugs are problematic and limited in children. Withdrawal randomization versus placebo in responders previously recognized in an open phase is a new design reported in adults which allows comparison to placebo without delaying the administration of the active compound. We applied such a design in refractory epileptic children in order to study vigabatrin (VGB) in children. Twenty-eight patients aged 1.5-18.5 years and having partially responded to VGB, prescribed in an open study for refractory epilepsy, were included. Patients were randomized to VGB (continued) or placebo (VGB blindy stopped in 3 weeks) for 2 months and seizure frequency was compared to the prerandomization period. More than 50% increase in seizure frequency induced drop-out. Fifteen patients received VGB, 13 others placebo, with the same clinical characteristics in both groups. The patients remaining in the study (primary efficacy endpoint) were more numerous on VGB (93%) than on placebo (46%) (P < 0.01) and seizure frequency (secondary endpoint) was lower on VGB than placebo (P < 0.05). The same results were observed in a subgroup of partial epilepsies. No status epilepticus was observed when withdrawing VGB and all patients returned to baseline status by reintroducing VGB. Such a randomized withdrawal design is therefore feasible in epileptic children. It provides the first VGB controlled study in this age range and demonstrates efficacy. It could be useful for future designs of drug trials in childhood epilepsy.

Adolescent↗
PubMed1996

Shewanella alga bacteremia in two patients with lower leg ulcers.

The first Danish cases of Shewanella alga bacteremia in two patients with chronic lower leg ulcers are reported. Both patients were admitted to the hospital during the same month of a very warm summer and had been exposed to the same marine environment, thereby suggesting the same source of infection. Both patients survived; however, one of them had extensive myonecrosis, while the other patient had an uncomplicated course. The strains were initially believed to be Shewanella putrefaciens on the basis of key characteristics and results of the API 20NE identification system (bioMérieux, Marcy l'Etoile, France), but further genetic and physiological analyses identified them as Shewanella alga.

Aged↗
PubMed1996

Interaction between fish spoilage bacteria Pseudomonas sp. and Shewanella putrefaciens in fish extracts and on fish tissue.

The interaction between fish spoilage bacteria, Pseudomonas sp. and Shewanella putrefaciens, was investigated using fish extract and fish tissue as model systems. Isolates of Pseudomonas that produced iron chelators, siderophores, inhibited growth of S. putrefaciens in a fish-extract-agar diffusion assay but no, or only weak, antagonistic activity was seen when the medium was supplemented with iron. Sterile-filtered supernatant fluid from a siderophore-producing Pseudomonas grown in fish extract was inhibitory to S. putrefaciens if the number of Psudomonas was above 10(8) cfu ml-1. In contrast, supernatant fluids from siderophore-negative Pseudomonas isolates did not inhibit growth of S. putrefaciens. The inhibitory effect was, except for one strain of Pseudomonas, not seen in supernatant fluids from iron-enriched cultures of Pseudomonas sp. Finally, siderophore-producing Pseudomonas sp. lowered the maximum cell level of S. putrefaciens 1-2 log units from 10(9) to 10(10) cfu g-1 when the strains were grown on fish muscle blocks at 0 degrees C but the growth rate of S. putrefaciens was not affected.

Agar↗
PubMed1996

Pharmacokinetics of new antiepileptic drugs.

This article surveys the pharmacokinetic parameters for the new antiepileptic drugs (AEDs): felbamate, gabapentin, lamotrigine, oxcarbazepine, tiagabine, topiramate, and vigabatrin. Compared to the pharmacokinetics of standard AEDs, these new AEDs have progressed in terms of (a) longer half-lives, permitting once- or twice-daily dosing, (b) greatly reduced potential for drug interactions, thus increasing ease of treatment, and (c) general lack of hepatic enzyme induction, which facilitates polytherapy as well as other aspects of treatment.

Acetates↗
PubMed1996

Changes in cell morphology of Listeria monocytogenes and Shewanella putrefaciens resulting from the action of protamine.

Protamine, which is an antibacterial basic peptide, was shown to alter the cell morphology of Listeria monocytogenes and Shewanella putrefaciens. Atomic force microscopy revealed that protamine smoothed the surface of cells, formed holes in the cell envelope, and caused fusion of S. putrefaciens cells. Immunoelectron microscopy of protamine-treated cells of both L. monocytogenes and S. putrefaciens showed great damage to the cell wall and condensation of the cytoplasm. Respiration of the cells was decreased due to treatment with sublethal concentrations of protamine, probably due to leakage or loss of cell envelope potential. It was concluded that protamine disrupted the outer surface structure and condensed the cytoplasm of sensitive cells and, in sublethal concentrations, altered membrane structures, thereby eliminating respiration.

Fluorescent Dyes↗
PubMed1996

Eukaryotic interference with homoserine lactone-mediated prokaryotic signalling.

Acylated homoserine lactones (AHLs) play a widespread role in intercellular communication among bacteria. The Australian macroalga Delisea pulchra produces secondary metabolites which have structural similarities to AHL molecules. We report here that these metabolites inhibited AHL-controlled processes in prokaryotes. Our results suggest that the interaction between higher organisms and their surface-associated bacteria may be mediated by interference with bacterial regulatory systems.

4-Butyrolactone↗