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Biomedical subjects

J Jorgensen

Publications and source records attributed to J Jorgensen.

At least 19 recordsLinked to original sources

Interpretive criteria and quality control for antimicrobial susceptibility tests of levofloxacin.

To confirm preliminary interpretive breakpoints for prototype 5 micrograms levofloxacin disks, 490 strains were tested in vitro using commercially manufactured disks. For in vitro susceptibility testing, 5 micrograms levofloxacin disks can be used with interpretive criteria of < or = 12 mm for resistant (MIC > or = 8.0 micrograms/ml) and > or = 16 mm for susceptible (MIC < or = 2.0 micrograms/ml). Proposed quality control limits for tests of levofloxacin are as follows: Escherichia coli ATCC 25922, zones 29-37 mm or MIC 0.008-0.03 microgram/ml; Pseudomonas aeruginosa ATCC 27853, zones 19-26 mm or MIC 0.5-2.0 micrograms/ml; Staphylococcus aureus ATCC 25923, zones 24-31 mm; Staphylococcus aureus ATCC 29213, MIC 0.06-0.25 microgram/ml and Enterococcus faecalis ATCC 29212, MIC 0.25-2.0 micrograms/ml.

Bacteriological Techniques

Extraperitoneal 'laparoscopic' adrenalectomy.

The technique of extraperitoneal 'laparoscopic' adrenalectomy is described in two cases, a left sided 1 cm Conn's tumour and a right sided 3.5 cm incidental non-functioning tumour. The extraperitoneal approach has the advantage of direct access to the adrenal gland without the need to mobilize abdominal organs, while maintaining all the advantages of minimal access surgery.

Adrenal Gland Neoplasms

Evidence against multiple premenstrual syndromes: results of a multivariate profile analysis of premenstrual symptomatology.

The topic of a single vs multiple premenstrual syndromes has generated much discussion. In this study, multivariate profile analysis was used to determine whether or not physical and affective symptoms associated with the premenstrual syndrome (PMS) could be explained as the manifestation of one underlying pathophysiologic process. The premenstrual symptom profiles of 820 undergraduate students and 485 graduate students were evaluated. It was not possible to reject the null hypothesis of parallel profiles in most comparisons, suggesting that variability in the severity of premenstrual symptoms may be the result of individual differences in the expression of one underlying pathophysiologic process.

Adolescent

The anorectal angle is not a reliable parameter on defaecating proctography.

Proctography is a standard method of investigating anorectal disorders. The parameters derived from this X-ray include the anorectal angle. The reproducibility of this measurement was assessed in 43 defaecating proctograms viewed by four observers on two separate occasions. Measurements were made at rest and during defaecation straining. Significant intra- and inter-observer variation was found. The anorectal angle is an inaccurate measurement, and should be interpreted with caution.

Anal Canal

A human T cell-specific molecule is a member of a new gene family.

We have used a cDNA library enriched for T cell-specific sequences to isolate genes expressed by T cells but not by other cell types. We report here one such gene, designated RANTES, which encodes a novel T cell-specific molecule. The RANTES gene product is predicted to be 10 kDa and, after cleavage of the signal peptide, approximately 8 kDa. Of the 68 residues, 4 are cysteines, and there are no sites for N-linked glycosylation. RANTES is expressed by cultured T cell lines that are Ag specific and growth factor dependent. RANTES expression is inducible in PBL by Ag or mitogen. In CTL, expression of RANTES decreases after stimulation with Ag and growth factors. Interestingly, RANTES was not expressed by any T cell tumor line tested. There is significant homology between the RANTES sequence and several other T cell genes, suggesting that they comprise a previously undescribed family of small T cell molecules.

Amino Acid Sequence

The isolation and sequence of a novel gene from a human functional T cell line.

Using a subtractive hybridization procedure we have constructed a cDNA library enriched for sequences present in functional human T cell lines, but not in human EBV-transformed B cell lines. We have isolated a cDNA clone, AH2-519, representing a novel gene, designated 519. This novel gene is expressed in functional human cytolytic and Th cell lines but not in a variety of other cell lines, including several long-term human T cell tumor lines. The expression of gene 519 is inducible in cultures of normal human PBL using antigenic or mitogenic stimulation. Neither the DNA sequence determined from a full-length cDNA clone overlapping with clone AH2-519 nor the amino acid sequence of its predicted protein product has significant homology to published sequences in the GenBank or NBRF databases. The restricted expression of gene 519 suggests that its gene product is involved in the growth and/or differentiation of normal T cells. The data also show that normal, nontransformed, functional T cells express gene products that can not be readily identified in long-term tumor lines of the same cell lineage.

Amino Acid Sequence

Results of a survey of antifungal susceptibility tests in the United States and interlaboratory comparison of broth dilution testing of flucytosine and amphotericin B.

In a survey of 350 laboratories, 41 of 210 respondents indicated that they performed antifungal susceptibility tests. Two-thirds performed 20 or fewer tests per year, and most used a broth dilution method to test amphotericin B and flucytosine activity against Candida albicans. The broth dilution procedure of S. Shadomy and A. Espinel-Ingroff (p. 647-653, in E.H. Lennette, ed., Manual of Clinical Microbiology, 3rd ed., 1980) was the method most frequently cited, and therefore this method was used to test the susceptibility of five isolates of C. albicans and one of Saccharomyces cerevisiae to amphotericin B and flucytosine in seven research laboratories. Agreement among replicates performed on the same day by each laboratory was excellent for both drugs, all values being within 1 twofold drug dilution. Precision from week to week for each laboratory was also good, with 95 and 92% of values being within 1 drug dilution for amphotericin B and flucytosine, respectively. Interlaboratory precision, however, was poor. For amphotericin B, values varied 8- to 32-fold, and for flucytosine, they varied 32- to greater than 512-fold. We conclude that antifungal susceptibility testing is currently being performed in small volumes by numerous laboratories in the United States and that results from one laboratory may not agree with results from another. Improved standardization of fungal susceptibility tests is necessary before their results can be generally applied to clinical situations.

Amphotericin B

Subgingival microflora of periodontal patients on tetracycline therapy.

Samples of subgingival plaque were collected from periodontal patients receiving two different tetracycline treatment regimens following conventional periodontal therapy. Four patients had received an oral dose of 1000 mg/day for 2 weeks and nine had received 1000 mg/day for 1 week followed by 250 mg/day for extended time periods. The latter regimen is similar so that commonly prescribed for the chronic skin disease, acne vulgaris. Taxonomic characterization of plaque isolates indicated that the predominant organisms cultured from both treatment groups were species of Streptococcus and the branching, filamentous Gram-positive rods, Actinomyces and Rothia. A much greater microbial complexity was observed among the flora isolated from patients taking 250 mg/day. The latter group harbored many of the fastidious Gram-negative organisms presently implicated in the etiology of periodontal disease. All bacterial strains isolated were tested for resistance to tetracycline by replica-plating cultures on an agar medium containing two-fold dilutions of the antibiotic. Streptococcus, Veillonella and Neisseria were the bacterial genera found to be consistently resistant to tetracycline, with minimum inhibitory concentrations as high as 128 micrograms/ml. Among the Actinomyces, selection for antibiotic resistance was common only within a single species, A. odontolyticus. However, A viscosus strains isolated at 54% of the subgingival flora from one patient did demonstrate an intermediate resistance level, growing on concentrations up to 8 micrograms/ml. Tetracycline resistance was shown by a variety of Gram-negative rods isolated from the low dosage group. Although a minimum number of patients were studied, extensive microbial analyses of the predominating subgingival bacteria indicated that the goal of tetracycline therapy was achieved during the 2-week therapy period at 1000 mg/day.

Actinomyces

Some characteristics of Escherichia coli strains isolated from extraintestinal infections of humans.

Escherichia coli strains isolated from extraintestinal infections of humans possess a constellation of phenotypes not usually found in random fecal isolates, enteropathogenic strains, or the laboratory strain E. coli K12. The phenotypes found more commonly in extraintestinal strains include hemolysin production, the biosynthesis of colicin V, and the hemagglutination of human erythrocytes in the presence of D-mannose (HAh). Hemolysin is assumed to be a cytotoxic factor, colicin V is assumed to interfere with host defense mechanisms, and HAh is assumed to play a role in specific tissue adherence. In addition, greater than or equal to 50% of E. coli strains from extraintestinal infections kill allantoically inoculated 13-day-old chick embryos. Some (20%) of the fecal E. coli also kill embryos, but E. coli K12 is innocuous in this virulence model. The plasmids for hemolysin and colicin V production have been transmitted to E. coli K12 derivatives but are not sufficient to convert laboratory strains to a form virulent for the chick embryo.

Adhesiveness

Association of hemolysin production, hemagglutination of human erythrocytes, and virulence for chicken embryos of extraintestinal Escherichia coli isolates.

One hundred forty-two strains of Escherichia coli isolated from extraintestinal infections were examined for colicin V (ColV) and hemolysin (Hly) production. For comparison, 20 strains isolated from the feces of normal individuals and 12 enteropathogenic strains of E. coli were tested for these properties. Thirty-five to 59% of extraintestinal isolates were Hly+, but only one fecal strain was Hly+. Colicin V biosynthesis was found for 12% of blood culture isolates, 7% of urine culture isolates and 16% of the strains from other extraintestinal infections. None of the fecal isolates was ColV+. Selected strains were tested for virulence in 13-day-old chicken embryos; these same strains were tested for their ability to hemagglutinate chicken or human erythrocytes. Of 22 extraintestinal isolates, 13 (59%) killed greater than or equal to 60% of the embryos within 72 h. Only one of eight normal fecal isolates and two of three enteropathogenic strains tested were virulent. About 80% of the virulent strains were Hly+. The most striking finding, however, was the hemagglutination of human erythrocytes by virulent extraintestinal isolates. It seems possible that the hemagglutination property reflects a specific common adherence factor.

Animals