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Biomedical subjects

C L Woodley

Publications and source records attributed to C L Woodley.

At least 19 recordsLinked to original sources
PubMed1995

Evaluation of infection control measures in preventing the nosocomial transmission of multidrug-resistant Mycobacterium tuberculosis in a New York City hospital.

OBJECTIVE: To evaluate the efficacy of Centers for Disease Control and Prevention (CDC)-recommended infection control measures implemented in response to an outbreak of multidrug-resistant (MDR) tuberculosis (TB). DESIGN: Retrospective cohort studies of acquired immunodeficiency syndrome (AIDS) patients and healthcare workers. The study period (January 1989 through September 1992) was divided into period I, before changes in infection control; period II, after aggressive use of administrative controls (eg, rapid placement of TB patients or suspected TB patients in single-patient rooms); and period III, while engineering changes were made (eg, improving ventilation in TB isolation rooms). SETTING: A New York City hospital that was the site of one of the first reported outbreaks of MDR-TB among AIDS patients in the United States. PARTICIPANTS: All AIDS patients admitted during periods I and II. Healthcare workers on nine inpatient units with TB patients and six without TB patients. RESULTS: The epidemic (38 patients) waned during period II and only one MDR-TB patient presented during period III. The MDR-TB attack rate among AIDS patients hospitalized on the same ward on the same days as an infectious MDR-TB patient was 8.8% (19 of 216) during period I, decreasing to 2.6% (5 of 193; P = 0.01) during period II. In a small group of healthcare workers with tuberculin skin test data, conversions during periods II through III were higher on wards with than without TB patients (5 of 29 versus 0 of 15; P = 0.15), although the difference was not statistically significant. CONCLUSIONS: Transmission of MDR-TB among AIDS patients decreased markedly after enforcement of readily implementable administrative measures, ending the outbreak. However, tuberculin skin-test conversions among healthcare workers may not have been prevented by these measures. CDC guidelines for prevention of nosocomial transmission of TB should be implemented fully at all US hospitals.

AIDS-Related Opportunistic Infections↗
PubMed1995

Nosocomial transmission of Mycobacterium tuberculosis: role of health care workers in outbreak propagation.

To investigate an outbreak of tuberculosis (TB) among health care workers (HCWs) at a county hospital, all patients with culture-confirmed TB on wards A and B and all HCWs working at least one shift on these wards from January 1991 through March 1992 were studied. Tuberculin skin test conversions occurred in 30% (ward A) and 48% (ward B) of HCWs; 8 developed active TB. Workers exposed for at least one shift to workers or patients with active TB were more likely to have skin test conversion than were workers who were not exposed (ward A exposure relative risk [RR] for workers = 2.8, P = .005, and for patients = 2.2, P > .5; ward B exposure RR for workers = 2.8, P < .001, and for patients = 5.3, P < .001). Underlying conditions and performing charting activities in the nurses' work room were associated with progression to active TB among infected workers. Transmission was facilitated by delays of < or = 2.5 months in treatment of workers with skin test conversion or TB symptoms.

Cross Infection↗
PubMed1994

Multiplex PCR assay specific for the multidrug-resistant strain W of Mycobacterium tuberculosis.

In 1991, a multidrug-resistant strain of Mycobacterium tuberculosis was isolated from eight people with tuberculosis at a state correctional facility in New York. This strain, which is designated strain W (IS6110 restriction fragment length polymorphism type 212072), was resistant to isoniazid, rifampin, ethambutol, streptomycin, kanamycin, ethionamide, and rifabutin. Since that outbreak, the W strain has been associated with outbreaks in five hospitals in the New York City area and is a continuing public health problem in the area. To be able to identify this strain rapidly, we developed a multiplex PCR assay which targets a direct repeat of IS6110 with a 556-bp intervening sequence (NTF-1). The amplification generates two amplicons from strain W, which indicate the presence and orientation of the NTF-1 sequence between the direct repeat of IS6110, and a third amplicon, which serves as an internal PCR control. The assay was evaluated with 193 isolates of M. tuberculosis, and all 48 strain W isolates among those 193 isolates were correctly identified.

Antitubercular Agents↗
PubMed1993

Tuberculosis in a correctional facility.

BACKGROUND: After the identification of five suspected cases of tuberculosis (TB) in a Nassau County (New York) jail during a 3-week period, an epidemiologic investigation was begun to document the number of cases of TB infection and disease associated with the jail, the characteristics of current or former inmates with TB disease, and the factors contributing to TB transmission in the jail. METHODS: The county TB register was matched against the inmate files of the jail. Medical records from hospitals, the health department, and the jail were then reviewed. All inmates in the jail were skin tested during a mass screening. RESULTS: From January 1, 1988, through March 16, 1990, of 205 TB cases in the county, 49 (24%) were associated with the jail. Forty of the cases occurred among current or former inmates, one in a corrections officer, and eight among community contacts of inmates. The 40 inmates with TB were predominantly nonwhite (75%), unmarried (80%) men (90%), with a median age of 32 years. Twenty-three (58%) had a history of injecting drug use, and 14 (35%) were known to be seropositive for the human immunodeficiency virus. Thirty (75%) of the inmates had culture-confirmed pulmonary TB. Five (29%) of 17 Mycobacterium tuberculosis isolates had the same phage type and DNA fingerprint, which was consistent with transmission of infection within the jail. The mass screening revealed that 374 (20%) of 1855 inmates were tuberculin positive. CONCLUSIONS: Without an effective program of TB control, jails can act as reservoirs of disease for inmates and staff, and for the community into which the inmates are released.

Adult↗
PubMed1993

Transmission of multidrug-resistant Mycobacterium tuberculosis among persons with human immunodeficiency virus infection in an urban hospital: epidemiologic and restriction fragment length polymorphism analysis.

From January 1990 to December 1991, 16 patients with multidrug-resistant tuberculosis (MDR-TB) caused by Mycobacterium tuberculosis resistant to isoniazid, rifampin, and streptomycin were diagnosed at Elmhurst Hospital. Compared with other TB patients, MDR-TB patients were more likely to have human immunodeficiency virus (HIV) infection (14/16 vs. 21/204, P < .001) and a prior admission (10/16 vs. 3/204, P < .001). HIV-infected patients hospitalized for > 10 days within three rooms of an infectious MDR-TB patient had higher risk of acquiring MDR-TB than did HIV-infected patients with shorter hospitalizations or locations further from the MDR-TB patient(s) (6/28 vs. 2/90, P < .001). Isolates of 6 of 8 MDR-TB patients in a chain of transmission were identical by restriction fragment length polymorphism DNA typing. Ambulation on the wards of inadequately masked TB patients and lack of negative pressure in isolation rooms probably facilitated transmission. This report documents nosocomial transmission of MDR-TB and underscores the need for effective isolation practices and facilities in health care institutions.

AIDS-Related Opportunistic Infections↗
PubMed1993

Mycobacterium celatum sp. nov.

A new slowly growing nonphotochromogenic Mycobacterium species of clinical importance is described. The biochemical characteristics of this organism were similar to those of Mycobacterium xenopi and members of the Mycobacterium avium complex. However, none of the strains reacted with commercially available genetic probes for the M. avium complex. The strains were resistant to most antituberculosis drugs. Multilocus enzyme electrophoresis revealed two original electrophoretic types, which was suggestive of new species. The strains contained alpha-, keto-, and dicarboxylic mycolates, as determined by thin-layer chromatography. A mycolic acid analysis by high-performance liquid chromatography revealed a chromatographic pattern similar to that of M. xenopi, but distinct from the patterns of previously described Mycobacterium species. Hexadecanoic and tuberculostearic acids were identified as the major cell wall fatty acids by gas-liquid chromatographic analysis; hexacosanoic acid was the major mycolic acid cleavage product, and 2-eicosanol was the major alcohol. Evaluation of the 16S rRNA sequence confirmed the phylogenetic position of the organism among the slowly growing Mycobacterium species. Cultures representing this new species have been deposited in the American Type Culture Collection as strains ATCC 51130 and ATCC 51131T (T = type strain). The name Mycobacterium celatum is proposed.

Bacterial Typing Techniques↗
PubMed1993

Rapid, amplification-based fingerprinting of Mycobacterium tuberculosis.

Insertion element IS6110 occurs in multiple copies throughout the Mycobacterium tuberculosis genome, and the variability of its insertion sites is the basis for the IS6110 restriction fragment length polymorphism (RFLP) method for typing. We describe a novel gene amplification method to assess the variability of the location of IS6110. A unilateral-nested polymerase chain reaction and hybridization procedure was used to measure the variability in the distances between IS6110 elements and copies of a major polymorphic tandem repeat sequence of M. tuberculosis. The pattern of amplicons produced could be used to cluster epidemiologically related strains of M. tuberculosis into groups which correlated with the groups formed using IS6110-RFLP typing. Reliable patterns can be generated directly from sputum specimens as well as from M. tuberculosis cultures. We designated the novel method as IS6110-ampliprinting.

Bacterial Typing Techniques↗
PubMed1993

Mixed-linker polymerase chain reaction: a new method for rapid fingerprinting of isolates of the Mycobacterium tuberculosis complex.

Rapid recognition of multidrug-resistant strains of Mycobacterium tuberculosis is a desirable goal for treatment of patients and protection of health care workers. DNA fingerprints produced with the insertion sequence IS6110 generate restriction fragment length polymorphism (RFLP) patterns that reliably identify M. tuberculosis complex strains. This report describes a rapid technique for RFLP typing using the polymerase chain reaction. The method uses one primer specific for IS6110 and a second primer complementary to a linker ligated to the restricted genomic DNA. In one strand the linker contains uracil in place of thymidine, and specific amplification is obtained by elimination of this strand with uracil N-glycosylase. Mixed-linker fingerprinting clearly differentiated multidrug-resistant isolates from 12 outbreaks and unambiguously assigned them to 26 RFLP groups.

Base Sequence↗
PubMed1992

Differentiation of slowly growing Mycobacterium species, including Mycobacterium tuberculosis, by gene amplification and restriction fragment length polymorphism analysis.

A two-step assay combining a gene amplification step and a restriction fragment length polymorphism analysis was developed to differentiate the Mycobacterium species that account for greater than 90% of potentially pathogenic isolates and greater than 86% of all isolates in clinical laboratories in the United States. These species are M. tuberculosis, M. bovis, M. avium, M. intracellulare, M. kansasii, and M. gordonae. With lysates of pure cultures as the template, two oligonucleotide primers that amplified an approximately 1,380-bp portion of the hsp65 gene from all 139 strains of 19 Mycobacterium species tested, but not from the 19 non-Mycobacterium species tested, were identified. Digestion of the amplicons from 126 strains of the six most commonly isolated Mycobacterium species with the restriction enzymes BstNI and XhoI in separate reactions generated restriction fragment patterns that were distinctive for each of these species, except for those of M. tuberculosis and M. bovis, which were not distinguishable. By including size standards in each sample, the restriction fragment profiles could be normalized to a fixed distance and the similarities of patterns could be calculated by using a computer-aided comparison program. The availability of this data base should enable the identification of an unknown Mycobacterium strain to the species level by a comparison of the restriction fragment pattern of the unknown with the data base of known patterns.

Bacterial Typing Techniques↗
PubMed1991

Mammalian seryl-tRNA synthetase associates with mRNA in vivo and has homology to elongation factor 1 alpha.

Previous work in our laboratories (Slobin, L. I., and Greenberg, J.R. (1988) Eur. J. Biochem. 173, 305-310) showed that messenger ribonucleoprotein (mRNP) particles possess a polypeptide component of approximately 62 kDa that appears to share a common epitope with eucaryotic elongation factor 1 alpha (EF-1 alpha). We report here that the previously unidentified mRNP constituent corresponds to seryl-tRNA synthetase (SerRS). Furthermore, we show that SerRS contains a sequence motif that is shared by both EF-1 alpha and glutaminyl-tRNA synthetase. We also find that the association of SerRS with mRNA depends on the functional state of the latter. Our data suggest that SerRS may participate directly in the initiation phase of protein synthesis.

Amino Acid Sequence↗
PubMed1988

Effects of eucaryotic initiation factor 3 on eucaryotic ribosomal subunit equilibrium and kinetics.

In order to understand the possible role of eucaryotic initiator factor 3 (eIF-3) in maintaining a pool of eucaryotic subunits, we have measured the effects of eIF-3 on the equilibria and kinetics of ribosomal subunit association and dissociation. The ribosomal subunit interactions have been studied by laser light scattering, which does not perturb the system. We find that eIF-3 reduces the apparent association rate of reticulocyte, wheat germ, and Artemia ribosomes. The kinetics of the reassociation for a shift in [Mg2+] from 0.5 to 6 mM are best explained by a model where eIF-3 dissociates from the 40S subunits prior to association of the 40S and 60S subunits. Static titrations indicate there is some binding of eIF-3 to 80S ribosomes at lower [Mg2+].

Animals↗
PubMed1988

Radiometric method for pyrazinamide susceptibility testing of Mycobacterium tuberculosis in egg-yolk-enriched BACTEC 12A medium.

A radiometric method for testing the susceptibility of Mycobacterium tuberculosis to pyrazinamide in egg-yolk-enriched 12A medium (pH 5.5) is described. We obtained 100% agreement between the 7H10 agar method with 25 microgram of pyrazinamide per ml and the modified radiometric method with a drug concentration of 50 microgram/ml in tests of 90 clinical isolates.

Animals↗
PubMed1987

A fluorescence study of the binding of eucaryotic initiation factors to messenger RNA and messenger RNA analogues.

The binding of the eucaryotic polypeptide chain initiation factors (eIFs) 4A, 4B, and 4F to poly(1,N6-ethenoadenylic acid) [poly(epsilon A)] was investigated by fluorescence spectroscopy. Competition experiments allowed us to determine the relative affinity of these proteins for mRNA cap analogues and the triplets AUG, GUG, UUU, UAA, and UGA. The salt dependence of eIF-4A binding to poly(epsilon A) and mRNA suggested that the binding was largely electrostatic and was enhanced in the presence of Mg2+ and ATP. The size of the binding site of eIF-4A, eIF-4B, and eIF-4F on poly(epsilon A) was approximately 13, 25, and 35 nucleotides, respectively. Fluorescence studies with the cap analogue 7-methylguanosine triphosphate as well as competition studies with poly(epsilon A) provide further evidence for a direct interaction of eIF-4F with the cap region. There was no evidence that either eIF-4B or eIF-4A bound the mRNA cap directly. In contrast to the other two factors, eIF-4B was found to bind preferentially to AUG, and of all the triplets tested, AUG was the most effective competitor for poly(epsilon A) binding.

Eukaryotic Initiation Factor-4A↗
PubMed1987

Evidence for simultaneous derepression of messenger RNA and the guanine nucleotide exchange factor in fertilized sea urchin eggs.

Translational control was studied in extracts of Lytechinus pictus eggs and zygotes. We showed that neither mRNA nor initiation factors alone limit translation in these lysates; rather they are together rate limiting. Added globin mRNA was translated in egg and zygote lysates but overall protein synthesis did not increase significantly as the added RNA competed with the endogenous message. The lysates mimicked the in vivo response, since microinjection of globin mRNA into L. pictus eggs similarly competed with endogenous mRNAs. A number of translational components were used to determine if they would stimulate protein synthesis in these lysates. The addition of globin polyribosomes increased the level of protein synthesis. The majority of this increase was due to reinitiation of the globin mRNA, and under these conditions the level of endogenous protein synthesis in both egg and zygote extracts did not change. The addition of crude initiation factors alone did not appreciably alter the rate of protein synthesis in the egg lysates. However, in the presence of added mRNA, these initiation factors stimulated translation two- to fourfold. Of all the initiation factors tested, only the guanine nucleotide exchange factor (GEF, eIF-2B, RF) significantly increased protein synthesis when globin mRNA was present. The addition of an unfractionated initiation factor preparation further stimulated protein synthesis in the presence of added GEF and mRNA, suggesting that a component other than mRNA and GEF was also limiting in these egg lysates. Other initiation factors, including eIF-2, eIF-4A, eIF-4B, and eIF-4F, did not substitute for the component in the unfractionated initiation factor preparation. We propose that alkalinization of the cytoplasm and the subsequent activation of initiation factors and mRNAs contribute to the large stimulation of protein synthesis in echinoid eggs after fertilization. Furthermore, we discuss the possibility that the increase in NADPH at the expense of NAD+, which occurs within 3 min after fertilization, may lead to the activation of GEF.

Animals↗
PubMed1986

Structural studies on the eukaryotic chain initiation factor 2 from rabbit reticulocytes and brine shrimp Artemia embryos. Phosphorylation by the heme-controlled repressor and casein kinase II.

In contrast to reticulocyte polypeptide chain initiation factor 2 (eIF-2), the Artemia factor retains activity in the presence of Mg2+ or after phosphorylation of its alpha-subunit by rabbit reticulocyte heme-controlled repressor (Mehta, H. B., Woodley, C. L., and Wahba, A. J. (1983) J. Biol. Chem. 258, 3438-3441). Furthermore, we have so far been unable to demonstrate a requirement for a GDP/GTP nucleotide exchange factor with Artemia eIF-2. In order to explain these differences we compared the structure of eIF-2 from Artemia and rabbit reticulocytes by using one- and two-dimensional phosphopeptide and iodopeptide maps. Partial trypsin digestion of the alpha-subunit of Artemia eIF-2 after phosphorylation by the heme-controlled repressor generates a 4000 Mr phosphopeptide. Upon extensive trypsin digestion, the two-dimensional phosphopeptide maps of the alpha-subunits for the reticulocyte and Artemia factors are indistinguishable, whereas the iodopeptide maps are different. In addition, immunoblotting indicates that there is no consistent cross-reactivity of the reticulocyte subunits with antibodies prepared in rabbits against the Artemia eIF-2 subunits. A casein kinase II activity was isolated from Artemia embryos that phosphorylates the beta-subunit of reticulocyte eIF-2, but specifically phosphorylates the alpha-subunit of eIF-2 preparations from several non-mammalian sources, including Artemia, yeast, and wheat germ embryos. Since this kinase phosphorylates a site distinct from that recognized by the heme-controlled repressor, and this phosphorylation does not alter the ability of Artemia eIF-2 to undergo nucleotide exchange, caution must be exercised when interpreting the significance of eIF-2(alpha) phosphorylation in non-mammalian cells.

Animals↗
PubMed1986

The association of NADPH with the guanine nucleotide exchange factor from rabbit reticulocytes: a role of pyridine dinucleotides in eukaryotic polypeptide chain initiation.

The guanine nucleotide exchange factor (GEF) was purified to apparent homogeneity from postribosomal supernatants of rabbit reticulocytes by chromatography on DEAE-cellulose and phosphocellulose, fractionation by glycerol gradients, and chromatography on Mono S and Mono Q (Pharmacia). At the Mono S step GEF is isolated as a complex with the eukaryotic polypeptide chain initiation factor 2 (eIF-2) and is separated from this factor by column chromatography on Mono Q. An emission spectrum characteristic of a reduced pyridine dinucleotide was observed when GEF was subjected to fluorescence analysis. By both coupled enzymatic analysis and chromatography on reverse-phase or Mono Q columns, the bound dinucleotide associated with GEF was determined to be NADPH. The GEF-catalyzed exchange of eIF-2-bound GDP for GTP was markedly inhibited by NAD+ and NADP+. This inhibition was not observed in the presence of equimolar concentrations of NADPH. Similarly, the stimulation of ternary complex (eIF-2 X GTP X Met-tRNAf) formation by GEF in the presence of 1 mM Mg2+ was abolished in the presence of oxidized pyridine dinucleotide. These results demonstrate that pyridine dinucleotides may be directly involved in the regulation of polypeptide chain initiation by acting as allosteric regulators of GEF activity.

Animals↗
PubMed1986

Evaluation of streptomycin and ethambutol concentrations for susceptibility testing of Mycobacterium tuberculosis by radiometric and conventional procedures.

Clinical isolates of Mycobacterium tuberculosis were used to compare various concentrations of streptomycin and ethambutol in the BACTEC 460 (Johnston Laboratories, Inc., Towson, Md.) radiometric method for drug susceptibility testing with those in the conventional method. Streptomycin used at 2.0 micrograms/ml for both methods showed a 0.99 agreement with susceptible strains and a 0.97 agreement with resistant strains. Ethambutol used at 2.5 micrograms/ml for the radiometric method showed 1.00 agreement with both susceptible and resistant strains when compared with ethambutol at 5.0 micrograms/ml for the conventional method.

Drug Resistance, Microbial↗