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1.
Public Health ; 224: 118-122, 2023 Sep 25.
Article in English | MEDLINE | ID: mdl-37757630

ABSTRACT

OBJECTIVE: Most respiratory virus surveillance relies on medically attended respiratory illness, but an understanding of the true patterns of infection independent of care-seeking behaviour would enhance clinical and public health responses to respiratory virus outbreaks. We evaluated the potential of decedent surveillance by estimating the burden of respiratory virus infection in decedents in a large, urban medical examiner's office. STUDY DESIGN: Observational. METHODS: In 2020-2022, we tested nasopharyngeal swabs from 4121 decedents in Detroit, Michigan for 15 respiratory viruses, including SARS-CoV-2, respiratory syncytial virus, and influenza virus A and B. We analysed infection prevalence over time and by age, sex, race/ethnicity, and manner of death. RESULTS: Of 4113 valid tests, 30.2% were positive for at least one virus, and 6.1% were positive for multiple viruses. All viruses were detected except for influenza A/H1N1 and influenza B. The most prevalent viruses were SARS-CoV-2 (15.7%), rhinovirus (11.2%), and adenovirus (4.9%), which were detected in all months. Most viruses exhibited decreasing prevalence with age, higher prevalence among Black and Hispanic than among White decedents and lower prevalence among deaths from natural causes; SARS-CoV-2 was a notable exception to the patterns by age and manner of death, instead reflecting community trends in catchment counties. CONCLUSIONS: There was high prevalence and diversity of respiratory viruses in decedents entering a large, urban medical examiner's office. Decedent surveillance could offer a clearer picture of the true underlying burden of infection, motivating public health priorities for intervention and vaccine development, and augmenting data for real-time response to respiratory virus outbreaks.

2.
Acta Chir Plast ; 65(1): 34-36, 2023.
Article in English | MEDLINE | ID: mdl-37211422

ABSTRACT

The authors present a novel modification of vastus lateralis muscle free flap based orbital reconstruction in a 41-year-old patient, with a secondary defect to an injury with technical oil under high pressure. The patient underwent multiple reconstructive procedures in different medical centers with poor functional and esthetic results including simple local plasty techniques. The patient underwent simultaneous reconstruction of the soft tissues of the orbit, and conjunctival sac based on a prelaminated vastus lateralis free flap. The two-stage reconstruction of these structures is beneficial both for the patient's psychical and mental condition and for health system finances. Therefore, whenever it's possible, we should try to decrease the number of required procedures. The authors believe that their technique can significantly improve the quality of life of patients after exenteration but simultaneously they emphasize the need to carry out more procedures in order to refine it.


Subject(s)
Lacrimal Apparatus , Plastic Surgery Procedures , Humans , Adult , Orbit/surgery , Lacrimal Apparatus/surgery , Quality of Life , Surgical Flaps
3.
Dalton Trans ; 49(10): 3088-3092, 2020 Mar 09.
Article in English | MEDLINE | ID: mdl-32051978

ABSTRACT

Two new, microporous MOFs of framework composition ((CH3)2NH2)2[M3O(HHTP)(HHTP˙)], M = Al3+, Ga3+, H6HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene, are described. Electron diffraction combined with molecular simulations show that these compounds crystallize in the ß-cristobalite structure, containing a new type of trinuclear inorganic building unit for MOFs and radical anions.

4.
J Fish Biol ; 79(1): 89-111, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21722113

ABSTRACT

A study on the feeding ecology of juvenile cod Gadus morhua, haddock Melanogrammus aeglefinus and whiting Merlangius merlangus during the pelagic to demersal transition was carried out on fishes sampled throughout their settlement season at a local nursery ground in the north-western North Sea, off the Scottish east coast. A comprehensive quantitative taxonomic analysis of the diets, as described in the paper, showed the emergence of distinctive feeding niches, minimizing the potential for competition between species and size categories. The diet of the juveniles changed with fish size, water depth, time of year and distance offshore. Small G. morhua were present in the study area earlier in the season, settled further inshore and ate a higher proportion of pelagic prey (copepods) and as size increased they moved into deeper waters and targeted larger, more benthic prey. As M. aeglefinus grew larger and moved into deeper waters, a diet of largely copepods, amphipods, pelagic Ammodytes spp., cyprids and pelagic gastropods evolved to one dominated predominantly by fishes and benthic invertebrates. In the case of M. merlangus, widespread ages and sizes throughout the sampling season, a consequence of their more protracted spawning season, resulted in dietary changes which were more likely to be influenced by seasonal changes in the prey field, in addition to developmental (size) changes, than the diets of the other two species.


Subject(s)
Diet , Feeding Behavior , Gadiformes/physiology , Gadus morhua/physiology , Animals , Gastrointestinal Contents , North Sea , Predatory Behavior , Seasons
5.
J Physiol Pharmacol ; 59 Suppl 6: 349-60, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19218659

ABSTRACT

Several biological markers have been proposed to improve the efficacy of diagnosing tuberculous pleurisy. The study was undertaken to evaluate the accuracy of pleural fluid adenosine deaminase (ADA) activity and interferon-gamma (IFN-gamma) concentration in differentiating tuberculous pleural effusion (TPE) and nontuberculous pleural effusion (non-TPE). Ninety four patients (50 M and 44 F, mean age 60+/-18, range 18-95 years) with pleural effusion (PE) were studied. TPE was diagnosed in patients with: (i) positive pleural fluid or pleural biopsy culture or (ii) granulomas in the pleural biopsy specimen, after exclusion of other granulomatous diseases. Pleural fluid ADA activity was measured with the colorimetric method of Giusti, while IFN-gamma level was measured with ELISA. TPE was diagnosed in 28 patients. The non-TPE group consisted of 35 patients with malignant PE, 20 patients with parapneumonic effusion/pleural empyema, 5 with pleural transudate, and 6 with miscellaneous PE. The ADA activity and IFN-gamma concentration were significantly higher in TPE than in non-TPE (614.1+/-324.5 vs. 15.1+/-36.0 pg/ml, P<0.0001 and 75.1+/-39.1 vs. 11.0+/-16.6 U/l respectively, P<0.0001). The diagnostic sensitivity and specificity of IFN-gamma measurement (cut-off value of 75.0 pg/ml) were 100% and 98.5% respectively and were similar to those of ADA (100% and 93.9% at the cut-off value of 40.3 U/L). We conclude that pleural fluid ADA activity and IFN-gamma concentration are highly sensitive and specific markers of tuberculous pleurisy.


Subject(s)
Adenosine Deaminase/analysis , Interferon-gamma/analysis , Pleural Effusion/chemistry , Tuberculosis, Pleural/diagnosis , Adolescent , Adult , Aged , Aged, 80 and over , Cell Count , Diagnosis, Differential , Female , Glucose/analysis , Humans , Hydrogen-Ion Concentration , L-Lactate Dehydrogenase/analysis , Male , Middle Aged , Mycobacterium tuberculosis , Pleural Effusion/enzymology , Pleural Effusion/pathology , Specific Gravity , Tuberculosis, Pleural/enzymology , Tuberculosis, Pleural/metabolism , Young Adult
6.
J Physiol Pharmacol ; 57(4): 677-89, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17229990

ABSTRACT

The objective of this study was to investigate the secretion of pancreatic enzymes and antibacterial activity in weaned pigs of three pure breeds, Pietrain, Duroc and Polish synthetic line 990, to look for eventual differences related to the genotype. Six male pigs of each breed, about 24 kg mean body weight, were equipped with chronic pancreatic duct catheters and duodenal cannulas to assess pure pancreatic juice, and jugular vein catheters for blood withdrawal. Pancreatic juice was collected before and after the morning feeding. Protein output and enzyme activities revealed two distinct profiles: strong manifestation of the prandial phase in Pietrain and line 990 pigs, and weak manifestation in Duroc. The antibacterial activity did not follow the enzyme kinetics, and it was the strongest in pancreatic juice from Pietrain pigs. Postprandial insulinaemia was reduced in the order of: line 990>Pietrain>Duroc. A slight (not significant) tendency towards a reduction of leptin after feeding in synthetic line 990 corresponded with elevated secretion of pancreatic enzymes and plasma insulin. The presented results suggest that the prandial secretion of pancreatic juice differs according to genotype, and the differences may be in part related to release of insulin.


Subject(s)
Pancreatic Juice/metabolism , Swine , Animals , Escherichia coli/drug effects , Genotype , Glucagon/blood , Insulin/blood , Leptin/blood , Male , Pancreatic Juice/enzymology , Pancreatic Juice/microbiology , Pancreatic Juice/physiology , Proteins/analysis , Species Specificity , Swine/genetics , Swine/growth & development , Swine/metabolism , Weight Gain
7.
Mycopathologia ; 159(1): 65-73, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15750733

ABSTRACT

Fusarium verticillioides is an important fungus occupying dual roles in the maize plant. The fungus functions as an endophyte, a fungal/host interaction beneficial to the growth of some plants. At other times, the fungus may function as a mycotoxin producing pathogen. The advantages and/or disadvantages of the endophytic relationship must be established in order to target appropriate sites for controlling diseases and mycotoxins in maize. One possibility could be to ensure seed maize is fungal free prior to planting. Reciprocal inoculations were made with two fungal isolates on seed of two maize genotypes. Yield was measured at harvest by ear and seed characters and vegetative growth at one-month intervals for plant survival, height, weight and stem diameter. Yield and vegetative growth differed among mature plants only once based on seed inoculation status. In 1998, plant weight was reduced and seed weight per ear was increased for the dent maize, GT-MAS: gk, grown from F. verticillioides RRC 374-inoculated seed compared to other seed treatments. Most vegetative characters were reduced at the first collection for Silver Queen plants grown from F. verticillioides-inoculated seed in 1997 and 1999, but not in 1998. However, no significant differences occurred among mature Silver Queen plants during any of the three growing seasons. In conclusion, yield and vegetative growth of mature maize plants grown from F. verticillioides-inoculated seed were equal to or greater than plants grown from non-inoculated seed under south Georgia field conditions during 1997, 1998, and 1999.


Subject(s)
Fusarium/growth & development , Seeds/microbiology , Zea mays/growth & development , Zea mays/microbiology , Climate , Georgia , Symbiosis
8.
Int J Tuberc Lung Dis ; 8(8): 1032-5, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15305490

ABSTRACT

Primary drug resistance of Mycobacterium tuberculosis strains in Poland increased two-fold between 1997 and 2000. Among 3705 drug-resistant strains investigated in 2000, 169 were resistant to streptomycin alone or in combination with isoniazid, rifampicin and/or ethambutol. The molecular basis of streptomycin resistance for 88 (52%) of these strains in comparison with 15 susceptible controls was determined. The most prevalent mutation was the single substitution Lys43Arg in the rpsL gene, found in 30.7% of the strains analysed. However, as many as 51% of the strains investigated carried no mutation in the rpsL or rrs genes. The multiple mutations present in two Beijing family strains were also identified.


Subject(s)
Antibiotics, Antitubercular , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/genetics , Streptomycin , DNA Mutational Analysis , Drug Resistance, Microbial , Genes, Bacterial , Humans , Microbial Sensitivity Tests , Poland/epidemiology , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , RNA, Bacterial/genetics , RNA, Ribosomal, 16S/genetics , Ribosomal Proteins/genetics
9.
Brain Res Brain Res Protoc ; 13(1): 26-36, 2004 Apr.
Article in English | MEDLINE | ID: mdl-15063838

ABSTRACT

The outer blood-retina barrier (BRB) is formed by the retinal pigment epithelium (rpe) and functions similarly to the blood-brain barrier (BBB). In contrast to the BBB, which is composed of a myriad of capillaries, the rpe can in principle be prepared as an intact planar tissue sheet without disruption of its barrier and carrier functions. Both a rapid and gentle procedure to isolate porcine rpe and a method to implement the harvested rpe in drug penetration testing are presented. Enucleated eyes were flat-mounted and the RPE/choroid tissue sheets with or without the retina were isolated. Fluorescence microscopy based on double-labeling with propidium iodide/calcein and scanning electron microscopy revealed well-preserved cell and tissue architecture. For drug evaluation, specimens were immobilized as the interface between test compartments in a dual-chamber device. Ten different test agents were added to one chamber at defined concentrations. After an incubation time of 30 min at 37 degrees C permeated drug levels in both compartments were quantified by HPLC-tandem mass spectrometry or HPLC with fluorescence detection. Sodium fluorescein used as a barrier marker indicated that the rpe model had excellent seal integrity. The use of a representative subset of pharmaceuticals with known BBB permeability characteristics demonstrated that the rpe model had a large permeability dynamic range (factor >350). These findings showed that the model represents a valuable tool for the investigation of the blood barrier penetration of test compounds.


Subject(s)
Blood-Retinal Barrier/physiology , Cell Membrane Permeability/physiology , Models, Biological , Organ Culture Techniques/methods , Pigment Epithelium of Eye/physiology , Animals , Artifacts , Blood-Retinal Barrier/drug effects , Cell Membrane Permeability/drug effects , Choroid/blood supply , Choroid/drug effects , Choroid/physiology , Diffusion Chambers, Culture/instrumentation , Diffusion Chambers, Culture/methods , Dissection/methods , Fluorescein/pharmacokinetics , Organ Culture Techniques/instrumentation , Pharmacokinetics , Pigment Epithelium of Eye/blood supply , Pigment Epithelium of Eye/drug effects , Reproducibility of Results , Sus scrofa
10.
Int J Tuberc Lung Dis ; 7(7): 645-51, 2003 Jul.
Article in English | MEDLINE | ID: mdl-12870685

ABSTRACT

SETTING: Three years after the last survey of drug-resistant tuberculosis in Poland, a nationwide survey was conducted by the National Tuberculosis Reference Laboratory in cooperation with all TB laboratories. OBJECTIVE: To determine the prevalence and patterns of primary and acquired drug resistance among Mycobacterium tuberculosis isolates recovered from tuberculosis patients in Poland in 2000 and to compare the results with an earlier survey carried out in 1997. DESIGN: In a prospective survey based on the questionnaires and strains of M. tuberculosis from all 16 regional centres participating in the study, 3705 questionnaires and cultures were obtained from 3037 new and 668 previously treated patients excreting TB bacilli during the 12-month period of 2000. Tests of resistance to isoniazid, rifampicin, streptomycin and ethambutol were performed using Löwenstein-Jensen and the Bactec system. RESULTS AND CONCLUSION: Compared with the previous survey in 1997, the current survey showed a twofold increase in tuberculosis resistance in new cases: any resistance was 3.6% in 1997 vs. 6.1% in 2000 (P < 0.001), multidrug resistance was 0.6% vs. 1.2% (P < 0.01), and no cases of four-drug resistance in 1997 vs. 15 cases in 2000. No statistical differences were observed in the rate of acquired resistance in both surveys.


Subject(s)
Drug Resistance, Bacterial , Tuberculosis/epidemiology , Adolescent , Adult , Aged , Data Collection , Drug Resistance, Multiple, Bacterial , Female , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/isolation & purification , Poland/epidemiology , Prevalence , Prospective Studies , Tuberculosis/microbiology
11.
Pneumonol Alergol Pol ; 70(7-8): 359-67, 2002.
Article in Polish | MEDLINE | ID: mdl-12708077

ABSTRACT

The amplified Mycobacterium tuberculosis direct test (MTD) (Gen-Probe Inc., San Diego, CA, USA) is a rapid technique of nucleic acid amplification which can be used directly on processed clinical specimens. It is based on the enzymatic amplification of ribosomal RNA via DNA intermediates, with detection of amplified product by an acridinum-ester-labeled DNA probe. The purpose of this study was to evaluate the clinical utility of this test for diagnosis of tuberculosis by comparing the sensitivity and specificity of the test with acid-fast smear, mycobacterial culture and clinical evaluation. The study included 399 specimens from patients, suspected of Tb which were submitted to the microbiological laboratory of our Institute over a 12 months period. Compared with bacterioscopy, conventional culture on L-J and rapid systems of cultivation (Bactec-450 Tb, MB/Bact, Bactec 960 MGIT) MTD had a sensitivity 93.2% and specificity 98.5%. We conclude, that MTD test which is completed within 6-8 hours, when used rationally, mainly in conjunction with routine smear and culture is a useful, rapid diagnostic test for suspected tuberculosis patients.


Subject(s)
Mycobacterium tuberculosis/isolation & purification , Nucleic Acid Amplification Techniques , RNA, Bacterial/analysis , Tuberculosis, Pulmonary/diagnosis , Bacteriological Techniques , Evaluation Studies as Topic , Humans , Mycobacterium tuberculosis/genetics , Nucleic Acid Amplification Techniques/methods , RNA, Ribosomal/analysis , Respiratory System/microbiology , Sensitivity and Specificity , Tuberculosis, Pulmonary/microbiology
12.
Ophthalmic Physiol Opt ; 21(6): 441-9, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11727872

ABSTRACT

Systemic hypertension is an important public health concern. If optometrists are to perform a more active role in the detection and monitoring of high blood pressure (BP), there is a need to improve the consistency of describing the retinal vasculature and to assess patient's ability to correctly report the diagnosis of hypertension, its control and medication. One hundred and one patients aged > 40 years were dilated and had fundus photography performed. BP was measured and a self-reported history of general health and current medication was compared with the records of their general practitioner (GP). The status of the retinal vasculature was quantified using a numeric scale by five clinicians and this was compared to the same evaluation performed with the aid of a basic pictorial grading scale. Image analysis was used to objectively measure the artery-to-vein (A/V) ratio and arterial reflex. Arteriolar tortuosity and calibre changes were found to be the most sensitive retinal signs of high BP. Using the grading scale to describe the retinal vasculature significantly improved inter- and intra-observer repeatability. Almost half the patients examined were on medication for high BP or cardiovascular disease. Patients' ability to give their complete medical history was poor, as was their ability to recall what medication they had been prescribed. GPs indicated it was useful to receive details of their patient's BP when it was > 140/90 mmHg. The use of improved description of the retinal vasculature and stronger links between optometrists and GPs may enhance future patient care.


Subject(s)
Hypertension/diagnosis , Medical History Taking/standards , Optometry/standards , Retinal Diseases/diagnosis , Adult , Aged , Aged, 80 and over , Antihypertensive Agents/therapeutic use , Blood Pressure Determination/methods , Female , Humans , Hypertension/drug therapy , Image Processing, Computer-Assisted , Male , Middle Aged , Observer Variation , Photography , Referral and Consultation , Regression Analysis , Retinal Diseases/drug therapy , Retinal Vessels
13.
J Pept Sci ; 7(8): 433-47, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11548059

ABSTRACT

From the culture broths of the mold Stilbella flavipes CBS 146.81, a mixture of polypeptides could be isolated by adsorption on XAD polystyrene resin and purified by Sephadex LH-20 chromatography. Using preparative thin-layer chromatography (TLC) three groups of peptides, named stilboflavins (SF) A, B, and C could be separated. Each of the groups showed microheterogeneity when investigated by high-performance liquid chromatography (HPLC). Employing on-line HPLC-electrospray ionization tandem mass spectrometry in the positive and negative ionization mode, together with gas chromatography-selected ion monitoring mass spectrometry, enantioselective GC and quantitative amino acid analysis, the sequences of stilboflavins A and B could be determined. Exchange of Glu in stilboflavins A peptides (acidic) against Gln in stilboflavins B peptides (neutral) is the rational for different polarity of the peptide groups and their separatability by TLC. Since SF A and B are bioactive N-acetylated 20-residue peptides with a high proportion of alpha-aminoisobutyric acid and C-terminal bonded amino alcohols (either leucinol, isoleucinol or valinol) the peptides belong to the group of peptaibol antibiotics.


Subject(s)
Anti-Bacterial Agents/chemistry , Flavins/chemistry , Flavins/isolation & purification , Hypocreales/chemistry , Peptide Library , Peptides/chemistry , Amino Acid Sequence , Chromatography, High Pressure Liquid , Fermentation , Gas Chromatography-Mass Spectrometry , Mass Spectrometry , Molecular Sequence Data , Time Factors
14.
J Biol Chem ; 276(21): 18597-604, 2001 May 25.
Article in English | MEDLINE | ID: mdl-11279140

ABSTRACT

The 2.5-kilobase pair poly(purine.pyrimidine) (poly(R.Y)) tract present in intron 21 of the polycystic kidney disease 1 (PKD1) gene has been proposed to contribute to the high mutation frequency of the gene. To evaluate this hypothesis, we investigated the growth rates of 11 Escherichia coli strains, with mutations in the nucleotide excision repair, SOS, and topoisomerase I and/or gyrase genes, harboring plasmids containing the full-length tract, six 5'-truncations of the tract, and a control plasmid (pSPL3). The full-length poly(R.Y) tract induced dramatic losses of cell viability during the first few hours of growth and lengthened the doubling times of the populations in strains with an inducible SOS response. The extent of cell loss was correlated with the length of the poly(R.Y) tract and the levels of negative supercoiling as modulated by the genotype of the strains or drugs that specifically inhibited DNA gyrase or bound to DNA directly, thereby affecting conformations at specific loci. We conclude that the unusual DNA conformations formed by the PKD1 poly(R.Y) tract under the influence of negative supercoiling induced the SOS response pathway, and they were recognized as lesions by the nucleotide excision repair system and were cleaved, causing delays in cell division and loss of the plasmid. These data support a role for this sequence in the mutation of the PKD1 gene by stimulating repair and/or recombination functions.


Subject(s)
DNA Repair/genetics , DNA, Bacterial/genetics , Escherichia coli/genetics , Proteins/genetics , DNA, Bacterial/chemistry , Humans , Mutation , Nucleic Acid Conformation , Recombination, Genetic , TRPP Cation Channels
15.
Ophthalmic Physiol Opt ; 20(5): 371-80, 2000 Sep.
Article in English | MEDLINE | ID: mdl-11045245

ABSTRACT

Conjunctival intraepithelial neoplasia (CIN) are considered to be the third most common ocular tumour and the most common tumour of the ocular surface. Due to their malignant potential, they must be carefully differentially and promptly treated. A recurrence rate of approximately 30% leads to the need for monitoring of patients even after successful treatment. This article presents several cases of CIN and reviews their histopathology, aetiology, appearance, differential diagnosis and management. Typical patient presentations and prognoses are also discussed.


Subject(s)
Carcinoma/diagnosis , Conjunctival Neoplasms/diagnosis , Aftercare , Aged , Biopsy , Carcinoma/etiology , Carcinoma/pathology , Conjunctival Neoplasms/etiology , Conjunctival Neoplasms/pathology , Diagnosis, Differential , Humans , Male , Middle Aged , Neoplasm Recurrence, Local/diagnosis , Prognosis , Ultraviolet Rays/adverse effects
16.
J Mol Biol ; 299(4): 865-74, 2000 Jun 16.
Article in English | MEDLINE | ID: mdl-10843843

ABSTRACT

We showed previously that mutations in methyl-directed mismatch repair of Escherichia coli reduced the occurrence of large deletions in (CTG.CAG)(175) repeats contained on plasmids. By contrast, other workers reported that mutations in mismatch repair increase the frequency of small-length changes in the shorter (CTG.CAG)(64). Using plasmids with a variety of lengths and purity of (CTG.CAG) repeats, we have resolved these apparently conflicting observations. We show that all lengths of (CTG.CAG) repeats are subject to small-length changes (eight repeats) in (CTG.CAG)(n) occur more readily in cells with active mismatch repair. The frequency of large deletions is proportional to the tract length; in our assays they become prominent in tracts greater than 100 repeats. Interruptions in repeat purity enhance the occurrence of large deletions. In addition, we observed a high level of incidence of deletions in (CTG.CAG) repeats for cultures passing repeatedly through stationary phase during long-term growth experiments of all strains (i.e. with active or inactive mismatch repair). These results agree with current theories on mismatch repair acting on DNA slippage events that occur in DNA triplet-repeats.


Subject(s)
Base Pair Mismatch/genetics , DNA Repair/genetics , Escherichia coli/genetics , Sequence Deletion/genetics , Trinucleotide Repeat Expansion/genetics , Trinucleotide Repeats/genetics , Bacterial Proteins/genetics , Bacterial Proteins/physiology , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Escherichia coli/growth & development , Gene Frequency/genetics , Genes, Bacterial/genetics , Models, Genetic , Molecular Weight , Mutagenesis, Insertional/genetics , Mutation/genetics , Plasmids/genetics
17.
J Pept Sci ; 6(4): 149-67, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10809388

ABSTRACT

Mixtures of the microheterogeneous 16-mer peptaibol antibiotics called antiamoebins (AAM) have been isolated from the culture broths of strains of the filamentous fungi Stilbella erythrocephala ATCC 28144, Stilbella fimetaria CBS 548.84 and Gliocladium catenulatum CBS 511.66. Sequences were determined using on-line HPLC together with positive- and negative-ion electrospray ionization mass spectrometry. Some characteristic features are recognized in the mass spectrometric fragmentation pattern of AAM. From a sample originally used for sequencing AAM (from Hindustan Antibiotics, Ltd., Pimpri, Poona-411018, India), and a sample of AAM commercially available (from Sigma Chemicals, St. Louis, MO, USA) HPLC elution profiles and sequences were assigned. Further, sequences of AAM previously isolated from Emericellopsis synnematicola CBS 176.60 and Emericellopsis salmosynnemata CBS 382.62 were determined. The peptide designated AAM I was the most abundant in all isolates and its structure could be confirmed. AAM II was detectable as a minor component (1.9%) only in the original sample of AAM, but not in the other isolates. The structures of AAM III, IV and V, which had previously been partly assigned, were definitely established, and the new sequences AAM VI-XVI were elucidated. AAM showing Phe1/Leu1 or Phe1/Val1 exchange, respectively, are produced in amounts only by S. erythrocephala. Sequences, HPLC elution profiles ('fingerprints') and relative amounts of peptides of all isolates were correlated.


Subject(s)
Anti-Bacterial Agents/chemistry , Fungi/metabolism , Peptides , Amino Acid Sequence , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/metabolism , Chromatography, High Pressure Liquid , Fermentation , Mass Spectrometry/methods , Mitosporic Fungi/metabolism , Molecular Sequence Data , Molecular Structure , Peptaibols
18.
J Chromatogr A ; 862(2): 179-89, 1999 Nov 12.
Article in English | MEDLINE | ID: mdl-10596975

ABSTRACT

Using high-performance liquid chromatography (HPLC) coupled to electrospray ionization mass spectrometry (ESI-MS) the sequences of the microheterogeneous peptide mixture of the 18-residue "peptaibol" antibiotics trichotoxins A-40, isolated from the mold Trichoderma viride strain NRRL 5242, were reinvestigated. The structures of two major and one minor component [J. Chromatogr., 296 (1984) 236] could be confirmed and hitherto not known sequences of a further major and two minor peptides could be determined. It is demonstrated that ESI-MS in the positive ionization mode is advantageously completed by applying negative ionization. The methods used make possible the sequence determination of components of peptaibols without previous isolation and allow, in certain cases, sequencing of peptides which are incompletely or not resolved by HPLC.


Subject(s)
Anti-Bacterial Agents/analysis , Peptides , Amino Acid Sequence , Chromatography, High Pressure Liquid , Mass Spectrometry , Molecular Sequence Data , Solvents , Spectrophotometry, Ultraviolet
19.
J Food Prot ; 62(11): 1326-32, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10571324

ABSTRACT

Biocontrol activity against Fusarium moniliforme was analyzed for a Trichoderma viride strain isolated from root segments of corn plants grown in Piedmont Georgia. The isolate suppressed radial extension of F. moniliforme colonies during cocultivation on potato dextrose agar and fumonisin B1 (FB1) production during incubation of both fungi on corn kernels. T. viride decreased radial extension of F. moniliforme by 46% after 6 days and by 90% after 14 days. Furthermore, the colony diameter of F. moniliforme was less at 14 days than at 5 days, suggesting that F. moniliforme mycelia were undergoing lysis. FB1 production by F. moniliforme on corn kernels decreased by 85% when both organisms were inoculated the same day onto corn kernels and by 72% when inoculation of T. viride was delayed by 7 days after F. moniliforme inoculation. These results are the first to demonstrate that T. viride can suppress FB1 production by F. moniliforme, thereby functioning to control mycotoxin production. Thus, this isolate may be useful in biological control to inhibit F. moniliforme growth as a preharvest agent to prevent disease during plant development and/or as a postharvest agent during seed storage to suppress FB1 accumulation when kernels are dried inadequately.


Subject(s)
Carboxylic Acids/metabolism , Fumonisins , Fusarium/metabolism , Trichoderma/physiology , Food Microbiology , Plant Roots/microbiology , Zea mays/microbiology
20.
J Pept Sci ; 5(8): 341-51, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10507683

ABSTRACT

From the culture broth of the mold Trichoderma viride NRRL 5243 a mixture of polypeptides, named trichovirins (TV), could be isolated and purified by chromatography on XAD-2 adsorber resin and Sephadex LH-20 gel. Chromatography on silica gel using chloroform/methanol 8:2 as eluent provided a mixture of peptides named TV I. Subsequent elution with chloroform/methanol 1:1 yielded a second group of peptides named TV II. That group could be separated into individual components by repetitive HPLC on an octadecylsilyl and a fluorocarbon stationary phase. The sequences of 12 peptides of TV II could be determined by electrospray ionization tandem mass spectrometry of isolated peptides and gas chromatography-mass spectrometry of methanolysates. The N-termini of the 18-mer peptides are acetylated and the C-termini consist of leucinol. Owing to the presence of alpha-aminoisobutyric acid (Aib) residues and the bactericidal and hemolytic activity, the peptides belong to the family of peptaibol antibiotics.


Subject(s)
Anti-Bacterial Agents/chemistry , Peptides , Trichoderma/chemistry , Amino Acid Sequence , Animals , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/pharmacology , Chromatography, High Pressure Liquid , Hemolysis/drug effects , Mass Spectrometry , Microbial Sensitivity Tests , Molecular Sequence Data , Protein Conformation , Sequence Homology, Amino Acid , Sheep
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