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K Nieman

Publications and source records attributed to K Nieman.

18 recordsLinked to original sources
PubMed2004

Isolation and characterization of polycyclic aromatic hydrocarbon-degrading Mycobacterium isolates from soil.

Bioremediation of soils contaminated with wood preservatives containing polycyclic aromatic hydrocarbons (PAHs) is desired because of their toxic, mutagenic, and carcinogenic properties. Creosote wood preservative-contaminated soils at the Champion International Superfund Site in Libby, Montana currently undergo bioremediation in a prepared-bed land treatment unit (LTU) process. Microbes isolated from these LTU soils rapidly mineralized the (14)C-labeled PAH pyrene in the LTU soil. Gram staining, electron microscopy, and 16S rDNA-sequencing revealed that three of these bacteria, JLS, KMS, and MCS, were Mycobacterium strains. The phylogeny of the 16S rDNA showed that they were distinct from other Mycobacterium isolates with PAH-degrading activities. Catalase and superoxide dismutase (SOD) isozyme profiles confirmed that each isolate was distinct from each other and from the PAH-degrading mycobacterium, Mycobacterium vanbaalenii sp. nov, isolated from a petroleum-contaminated soil. We find that dioxygenase genes nidA and nidB are present in each of the Libby Mycobacterium isolates and are adjacent to each other in the sequence nidB-nidA, an order that is unique to the PAH-degrading mycobacteria.

Base Sequence↗
PubMed2003

Non-invasive angiography of the coronary arteries with multislice computed tomography: state of the art and future prospects.

Until now conventional angiography has represented the only technique for assessing the coronary arteries. During the last decade, attempts have been made to validate a non-invasive technique for the study of coronary arteries. In particular, Electron-beam Tomography and Magnetic Resonance Imaging have been used for this purpose, even though they have not become clinical tools. More recently, spiral computed tomography (CT) technology, improved by the use of multiple slices and 500ms gantry rotation times, has shown a good potential without entering routine clinical practice. The introduction of multislice technology with 16 rows and rotation times below 500ms has yielded such good results in detecting significant (>50%) coronary artery stenosis that it has been proposed as a clinical tool. This paper describes the examination technique and the results achieved in CT angiography of the coronary arteries.

Coronary Angiography↗
PubMed2002

Non-invasive coronary angiography with multislice spiral computed tomography: impact of heart rate.

OBJECTIVE: To evaluate the impact of heart rate on the diagnostic accuracy of coronary angiography by multislice spiral computed tomography (MSCT). DESIGN: Prospective observational study. PATIENTS: 78 patients who underwent both conventional and MSCT coronary angiography for suspicion of de novo coronary artery disease (n=53) or recurrent coronary artery disease after percutaneous intervention (n=25). SETTING: Tertiary referral centre. METHODS: Intravenously contrast enhanced MSCT coronary angiography was done during a single breath hold, and ECG synchronised images were reconstructed retrospectively. All coronary segments of > or = 2.0 mm without stents were evaluated by two investigators and compared with quantitative coronary angiography. Patients were classified according to the average heart rate (mean (SD)) into three equally sized groups: group 1, 55.8 (4.1) beats/min; group 2, 66.6 (2.8) beats/min; group 3, 81.7 (8.8) beats/min. RESULTS: Image quality was sufficient for analysis in 78% of the coronary segments in patients in group 1, 73% in group 2, and 54% in group 3 (p < 0.01). The sensitivity and specificity for detecting significant stenoses (> or = 50% lumen reduction) in these assessable segments were: 97% (95% confidence interval (CI) 84% to 100%) and 96% in group 1; 74% (52% to 89%) and 94% in group 2; and 67% (33% to 90%) and 94% in group 3 (p < 0.05). Accounting for all segments of > or = 2.0 mm, including lesions in non-assessable segments as false negatives, the sensitivity decreased to 82% (28/34 lesions, 95% CI 69% to 91%), 61% (14/23 lesions, 42% to 77%), and 32% (6/19 lesions, 15% to 50%), respectively (p < 0.01). CONCLUSIONS: MSCT allows reliable coronary angiography in patients with low heart rates.

Confidence Intervals↗
PubMed2001

Functional activity and role of cation-efflux family members in Ni hyperaccumulation in Thlaspi goesingense.

The ability of Thlaspi goesingense to hyperaccumulate Ni seems to be governed in part by enhanced accumulation of Ni within leaf vacuoles. We have characterized genes from T. goesingense encoding putative vacuolar metal ion transport proteins, termed metal tolerance proteins (TgMTPs). These proteins contain all of the features of cation-efflux family members, and evidence indicates they are derived from a single genomic sequence (TgMTP1) that gives rise to an unspliced (TgMTP1t1) and a spliced (TgMTP1t2) transcript. Heterologous expression of these transcripts in yeast lacking the TgMTP1 orthologues COT1 and ZRC1 complements the metal sensitivity of these yeast strains, suggesting that TgMTP1s are able to transport metal ions into the yeast vacuole in a manner similar to COT1 and ZRC1. The unspliced and spliced TgMTP1 variants differ within a histidine-rich putative metal-binding domain, and these sequence differences are reflected as alterations in the metal specificities of these metal ion transporters. When expressed in yeast, TgMTP1t1 confers the highest level of tolerance to Cd, Co, and Zn, whereas TgMTP1t2 confers the highest tolerance to Ni. TgMTP1 transcripts are highly expressed in T. goesingense compared with orthologues in the nonaccumulators Arabidopsis thaliana, Thlaspi arvense, and Brassica juncea. We propose that the high-level expression of TgMTP1 in T. goesingense accounts for the enhanced ability of this hyperaccumulator to accumulate metal ions within shoot vacuoles.

Amino Acid Sequence↗
PubMed2001

Coronary angiography with multi-slice computed tomography.

BACKGROUND: A new generation of subsecond multi-slice computed tomography (MSCT) scanners, which allow complete coronary coverage, are becoming widely available. We investigated the potential value of MSCT angiography in a range of coronary disorders. METHODS: We studied 35 patients, including 11 who had undergone percutaneous transluminal coronary angioplasty and four who had had coronary-artery bypass grafts, by both MSCT and conventional coronary angiography. After intravenous injection of a non-ionic contrast medium with high iodine content, the entire heart was scanned within a single breath-hold. The total examination time was no more than 20 min. The retrospective electrocardiographically gated reconstruction source images and three-dimensional reconstructed volumes were analysed by two investigators, unaware of the results of conventional angiography. FINDINGS: In the 31 patients without previous coronary surgery, 173 (73%) of the 237 proximal and middle coronary segments were assessable. In the assessable segments, 17 of 21 significant stenoses (>50% reduction of vessel diameter) were correctly diagnosed. The non-assessable segments included four lesions. Misinterpretations were mainly the result of severe calcification of the vessel wall. Segments with implanted stents were poorly visualised, but stent patency could be assessed in all cases. Of the 17 segments of bypass grafts, 15 were assessable and four of five graft lesions were detected. Two cases of anomalous coronary anatomy could be visualised well. INTERPRETATION: These preliminary data suggest that MSCT allows non-invasive imaging of coronary-artery stenoses and has potential to develop into a reliable clinical technique.

Adult↗
PubMed2000

Impaired mitogen-activated protein kinase activation and altered cytokine secretion in endotoxin-tolerant human monocytes.

BACKGROUND: Dysregulation of monocyte/macrophage cytokine production after exposure to multiple inflammatory stimuli may contribute to multiple organ failure and sepsis. Endotoxin (lipopolysaccharide [LPS]) activation of murine macrophage results in the phosphorylation of kinases in the mitogen-activated protein kinase cascade. Pretreatment of murine macrophages with LPS induces LPS-tolerance, with inhibition of LPS-stimulated activation of kinases (ERK1/2 and p38) and diminished release of tumor necrosis factor (TNF). We sought to determine whether similar alterations in LPS-dependent signal transduction are present in LPS-tolerant human peripheral blood monocytes. METHODS: Human peripheral blood monocytes from healthy volunteer donors (n = 12) were incubated in RPMI 1640 culture medium +/- 10 ng/mL of LPS for 18 hours, then stimulated with 0 to 1,000 ng/mL of LPS. Supernatant TNF and interleukin-1 (IL-1) levels were measured after 5 hours by enzyme-linked immunosorbent assay. Activation of the p42/p44 kinases (ERK1/2) was measured 15 minutes after LPS with monoclonal antibodies to diphosphorylated (active) ERK1/2 using novel flow cytometric methods. RESULTS: LPS-tolerant (10 ng/mL LPS pretreatment) human monocytes had significant inhibition of LPS-stimulated TNF secretion but augmented IL-1 release (p < 0.05). Nontolerant human monocytes had a dramatic increase in the percentage of ERK1/2-positive cells in response to an initial stimulation with LPS. This did not occur in the LPS-tolerant cells. Phorbol-12-myristate-13 acetate restored ERK1/2 activation in LPS-tolerant human monocytes. CONCLUSION: LPS-tolerance in human monocytes is associated with inhibition of LPS-stimulated TNF secretion, augmented release of IL-1, and defective activation of mitogen-activated protein kinase cascade (ERK1/2). These results suggest a method of identifying LPS-tolerance and monocyte dysfunction in patients with sepsis.

Cytokines↗
PubMed2000

Impaired ex vivo lipopolysaccharide-stimulated whole blood tumor necrosis factor production may identify "septic" intensive care unit patients.

Currently, there is no reliable diagnostic test to identify septic intensive care unit (ICU) patients. We initiated studies to test the hypothesis that in sepsis, the in vivo exposure to endotoxin is detectable by the ex vivo analysis of lipopolysaccharide (LPS)-stimulated tumor necrosis factor (TNF) production. We obtained heparinized whole blood (WB) from 58 ICU patients and 14 healthy controls. The samples were incubated +/-10 ng/mL of LPS at 37 degrees C for 3 h. Plasma TNF levels were measured using enzyme-linked immunoassay (mean +/- standard error of the mean). Clinical data, including ICU length of stay (LOS), ventilator days (VentD), WBC, and positive cultures (Clt+), were obtained retrospectively. A wide range of LPS-stimulated WB TNF production (pg/mL) was observed in ICU patients (4481+/-469) and controls (6706+/-715). Patients were stratified into quartiles (I-IV) on the basis of the distribution of plotted LPS-stimulated TNF values (pg/mL). Patients in quartile I (N = 14) had significantly lower TNF production (< 2000 pg/mL, P < 0.05) and required increased VentD (16 vs. 10 days, P < 0.05) compared to quartiles II-IV (N = 44). Patients in quartile I also had a higher incidence of infection (79 vs. 50%) and longer LOS (18 vs. 13 d) compared to quartiles II-IV. Impaired TNF release may be a manifestation of monocyte endotoxin tolerance and may be useful to diagnose sepsis.

Adult↗
PubMed1985

Obstetrics in the physical therapy curriculum.

We report the status of obstetric education in physical therapy curricula. A questionnaire was sent to 83 accredited physical therapy education programs. Of the respondents from 69 programs, 47 (68%) included a specific unit or information on obstetrics in their program. The reporting programs averaged 7.5 hours for obstetric education. The unit was required in 45 of the 47 programs. Topics covered included anatomy and physiology, psychology, labor and delivery sequence, relaxation techniques, breathing techniques, prenatal and postpartum exercises, body mechanics, nutrition, fetal development, and birthing alternatives. Fifty-three percent of the units were taught by a physical therapist and combination of other professionals including a nurse, physician, nutritionist, psychiatric social worker, physiologist, or anatomist. We present behavioral objectives, required readings, and audiovisual aids used in the units.

Curriculum↗
PubMedDate not supplied

Comparison of different methods to define a target volume for external beam radiation therapy of restenotic coronary arteries.

PURPOSE: Different methods have been described to define a target volume for the treatment of restenotic (stented) coronary arteries by external beam radiation therapy (EBRT). The purpose of this study was to explore two methods to define a target for such therapy, and to compare these with previously investigated methods. MATERIALS AND METHODS: The 3-D position of a stent throughout the cardiac cycle in the three major epicardial coronary arteries was measured in three patients by single-breathhold multislice spiral CT and breathhold biplane conventional X-ray angiography, both indexed in time with the ECG. The volume through which the stent traversed (STV) during the cardiac cycle was determined by use of displacement measurements. RESULTS: For multislice CT and biplane angiography, respectively, the mean STV was 1.23 cm(3) (range 0.65-2.22 cm(3)) and 2.81 cm(3) (range 1.60-4.99 cm(3)). The STV represented only a fraction of the whole heart volume in all patients, that is, equal to or less than 0.4%. CONCLUSIONS: Multislice CT and biplane angiography allowed the measurement of a relatively small potential target, that is the STV, for EBRT of restenotic stented coronary arteries. Both studied imaging modalities are instrumental for targeting the STV by highly conformal radiation therapy in case of restenotic stented coronary arteries.

Coronary Angiography↗
PubMedDate not supplied

Non-invasive assessment of coronary artery stent patency with multislice CT: preliminary experience.

PURPOSE: To evaluate the diagnostic accuracy of multislice computed tomography coronary angiography (MSCT-CA) in the detection of in-stent restenosis. MATERIALS AND METHODS: Forty-two patients (33 male, 9 female, mean age 58+/-8 years) previously subjected to percutaneous implantation of coronary stent with suspected in-stent restenosis, underwent a 16-row MSCT (Sensation 16, Siemens) examination. The average time between stent implantation and MSCT-CA was 7.4+/-5.3 months. The following scan parameters were used: collimation 16x0.75 mm, rotation time 0.42 s, feed 3.0 mm/rot., kV 120, mAs 500. After administration of iodinated contrast material (Iomeprol 400 mgI/ml, 100 ml at 4 ml/s) and bolus chaser (40 ml of saline at 4 ml/s) the scan was completed in <20 s. All segments with a stent were assessed by two observers in consensus and were graded according to the following scheme: patent stent, in-stent intimal hyperplasia (IIH) (lumen reduction <50%), in-stent restenosis (ISR) (=/>50%), in-stent occlusion (ISO) (100%). Consensus reading was compared with coronary angiography. RESULTS: Forty-seven stents were assessed (16 in the right coronary artery; 4 in the left main; 22 in the left anterior descending; 5 in the circumflex). In 7 (17%) stents there was ISR (3) or ISO (4), and in 4 (10%) stents there was IIH. The sensitivity and negative predictive values for the detection of ISO were 80% and 98%, respectively, while for the detection of ISR+ISO they were 50% and 89%, respectively. CONCLUSIONS: Although the results are encouraging, the follow-up of stent patency with MSCT-CA does not show a diagnostic accuracy suitable for clinical implementation.

Journal Article↗