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Biomedical subjects

M Krauss

Publications and source records attributed to M Krauss.

At least 37 records · Page 2Linked to original sources
PubMed1999

Dualistic level competencies for professional nursing practice: an international educational initiative.

Ensuring professional nurses are competent is integral to promoting quality outcomes for persons with spinal cord impairment (SCI). This project, funded by the American Association of Spinal Cord Injury Nurses (AASCIN), was designed to develop instruments to validate the competencies of registered nurses (RNs) caring for persons with SCI. The project expanded a 1994 model project focusing on the competencies of licensed practical nurses and licensed vocational nurses (LPNs/LVNs) and RNs in an adult rehabilitation setting. Using the earlier project as a foundation, investigators identified competencies for RNs applicable to the life span trajectory of persons with SCI including pediatric, adolescent, adult, and geriatric populations. Additionally, the focus was broadened to encompass acute, rehabilitation, outpatient community, and long-term settings. This innovative project resulted in the development of the SCI Knowledge/Skill Competency tool for dualistic competency levels of "competent" RNs with two years of recent SCI nursing experience, and "expert" RNs with five years of recent SCI experience. Additionally, the SCI Behavior Competency tool for the "competent" level was developed using hermeneutic techniques and Patricia Benner's (1983) framework, "Novice to Expert." This complemented the "expert" level tool devised in the 1994 model project. Implementation will enable RNs to validate the competencies that are essential to provide care that results in quality outcomes for persons with SCI, their families, and other consumers of SCI health care services.

Adult↗
PubMed1998

Multicenter case-control study of exposure to environmental tobacco smoke and lung cancer in Europe.

BACKGROUND: An association between exposure to environmental tobacco smoke (ETS) and lung cancer risk has been suggested. To evaluate this possible association better, researchers need more precise estimates of risk, the relative contribution of different sources of ETS, and the effect of ETS exposure on different histologic types of lung cancer. To address these issues, we have conducted a case-control study of lung cancer and exposure to ETS in 12 centers from seven European countries. METHODS: A total of 650 patients with lung cancer and 1542 control subjects up to 74 years of age were interviewed about exposure to ETS. Neither case subjects nor control subjects had smoked more than 400 cigarettes in their lifetime. RESULTS: ETS exposure during childhood was not associated with an increased risk of lung cancer (odds ratio [OR] for ever exposure = 0.78; 95% confidence interval [CI] = 0.64-0.96). The OR for ever exposure to spousal ETS was 1.16 (95% CI = 0.93-1.44). No clear dose-response relationship could be demonstrated for cumulative spousal ETS exposure. The OR for ever exposure to workplace ETS was 1.17 (95% CI = 0.94-1.45), with possible evidence of increasing risk for increasing duration of exposure. No increase in risk was detected in subjects whose exposure to spousal or workplace ETS ended more than 15 years earlier. Ever exposure to ETS from other sources was not associated with lung cancer risk. Risks from combined exposure to spousal and workplace ETS were higher for squamous cell carcinoma and small-cell carcinoma than for adenocarcinoma, but the differences were not statistically significant. CONCLUSIONS: Our results indicate no association between childhood exposure to ETS and lung cancer risk. We did find weak evidence of a dose-response relationship between risk of lung cancer and exposure to spousal and workplace ETS. There was no detectable risk after cessation of exposure.

Aged↗
PubMed1998

[Imaging of aortic endoprostheses and their complications].

PURPOSE: To determine the optimal postoperative imaging modality for the follow-up of patients with endoluminal aortic stent grafts. MATERIAL AND METHODS: From August 1994 to November 1997, 214 patients (194 male and 20 female) with abdominal and thoracic aortic aneurysms were treated with endovascular stent grafts. 137 patients (129 male, 8 female) with 89 tube grafts and 48 bifurcated grafts (45 EVT, 88 Stentor/Vanguard, 3 Chuter, 1 Talent) were evaluated with contrast-enhanced spiral-CT, duplex ultrasound, and DSA at a mean follow-up of 11.1 months. RESULTS: We found 12 persistent primary endoleaks (8.8%), 17 secondary endoleaks (12.4%), 8 limb occlusions (5.8%), 28 endoluminal thrombi lining the stent graft (20.4%), and 26 suture breakages of the stent frame (19%). In 9 patients (6.6%) the proximal end of the stent partially covered the renal arteries. In 3 patients (2.2%) a partial renal infarction was seen. Spiral-CT was able to demonstrate all the above changes except for 3 sidebranch endoleaks that were documented by duplex ultrasound only and 8 suture breaks seen on abdominal plain films only. The median aneurysm diameter decreased from 48 mm pre-operatively to 46 mm at 24 months post-operatively in patients with endoleaks and from 44 mm to 36 mm in patients without endoleak. For several patients the decreasing aneurysm diameter did not reliably correlate with complete exclusion of the aneurysm. CONCLUSION: For follow-up of endoluminal aortic stent grafts contrast-enhanced spiral-CT is superior to duplex ultrasound. DSA is necessary only for patients with complications requiring a secondary intervention.

Adult↗
PubMed1998

Environmental tobacco smoke and lung cancer.

In a case-control study of 1,004 lung cancer cases and 1,004 population controls, all nonsmokers (71 cases, 236 controls) were interviewed for their exposure to environmental tobacco smoke. On the basis of indices of duration, we separated intermediate and high exposures from low or no exposure. The odds ratio for high exposure was 2.09 (95% confidence interval = 1.02-4.28). Exposure from the spouse was only weakly associated with lung cancer risk. We found little association for exposure during childhood. High exposure at the work place showed an odds ratio of 1.91. There was little indication of confounding by dietary habits.

Adult↗
PubMed1998

Benign familial pemphigus (Hailey-Hailey disease). Treatment with the pulsed carbon dioxide laser.

BACKGROUND: Benign familial pemphigus (BFP) is a chronic blistering disease with significant morbidity. Surgical methods are often needed to control flares in difficult cases. OBJECTIVE: To describe the response of BFP to vaporization with a pulsed carbon dioxide (CO2) laser. METHODS: A 38-year-old woman with chest and axillary involvement unresponsive to conventional therapy was treated with the UltraPulse 5000 Laser (Coherent Medical Group, Palo Alto, CA). After active sites of BFP showed good response to treatment, we treated uninvolved skin of the left axilla to assess the efficacy of prophylactic therapy. RESULTS: Treatment of affected areas, except biopsy sites, resulted in clearing of active lesions after 1-2 weeks. We noted striking sparing of the treated areas from developing subsequent disease. The region that was later treated prophylactically has shown minor, asymptomatic recurrence of BFP in less than 5% of the area treated over an 18-month follow-up period. CONCLUSION: The pulsed carbon dioxide laser is a useful modality in treatment of BFP. In our patient, prophylactic treatment led to near complete eradication of disease in the treated area. A controlled, larger study is needed to confirm our results, and to determine optimal laser parameters. Long-term effects and duration of remission remain to be determined.

Adult↗
PubMed1997

Interactions of the nicotinic acetylcholine receptor transmembrane segments with the lipid bilayer in native receptor-rich membranes.

Proper ion channel function of the nicotinic acetylcholine receptor (nAChR) requires the interaction of the protein with distinct lipid species present in the receptor's membrane microenvironment. Two classes of lipid binding sites present at the protein-membrane interface have been postulated: annular binding sites primarily occupied by phospholipids and non-annular binding sites mainly occupied by cholesterol [Jones & McNamee (1988) Biochemistry 27, 2364-2374]. We investigated the binding of these lipids to the nAChR and potential dynamics of these interactions during events associated with signal transduction by electron spin resonance spectroscopy (ESR) using spin-labeled analogues of phospholipids, androstane, and stearic acid. Protein-lipid interactions were characterized in receptor-rich membranes prepared from Torpedo californica electric tissue preserving the native lipid environment of the nAChR. We found a strong preference of the receptor for the phosphatidylserine (PS) analogue as compared to the other probes. Up to 57% of PS were perturbed by the membrane protein, while the fraction of motionally restricted lipid for the other analogues was on the order of 30%. After removal of the extramembrane portions of the membrane-bound receptor, we observed a loss of binding sites for the spin-labeled analogue of androstane and for stearic acid, but not for phospholipids and sphingomyelin analogues. Our results demonstrate the existence of topologically distinct lipid binding sites for different lipid species. In the case of cholesterol, extramembrane portions of the receptor are involved, whereas the transmembrane segments meet the requirements for the binding of phospholipids. Tyrosine phosphorylation of the nAChR did not affect protein-lipid interactions in samples of intact nAChR. Similarly, no significant changes were observed in the presence of carbamoylcholine at concentrations that caused rapid and quantitative desensitization of the nAChR.

Animals↗
PubMed1997

In vivo formation of prostaglandin E1 and prostaglandin E2 in atopic dermatitis.

Immunological and biochemical alterations in atopic dermatitis have been attributed to a deficient conversion of omega-6 fatty acids (i.e. linoleic acid, gamma-linolenic acid, and dihomo-gamma-linolenic acid) to prostaglandin (PG) E1. In patients with atopic dermatitis, however, the formation of PGE1 has not been evaluated so far. We therefore measured plasma concentrations of 15-keto-13,14-dihydro-PGE1, which reflects endogenous PGE1 release, by gas chromatography-mass spectrometry in 31 patients with atopic dermatitis (aged 18-41 years, median 26 years) and in 31 healthy, age- and sex-matched control subjects. In order to exclude a metabolic shift from PGE1 to PGE2, we also measured the plasma levels of 15-keto-13,14-dihydro-PGE2. There was no difference between patients and control subjects with respect to plasma concentrations of 15-keto-13,14-dihydro-PGE1 (3.9-49.6, median 10.3 pg/ml vs. 3.2-80.4, median 8.3 pg/ml, P = 0.22), 15-keto-13,14-dihydro-PGE2 (11.6-201.0, median 24.8 pg/ml vs. 8.6-201.0, median 19.6 pg/ml, P = 0.10), and the ratio of 15-keto-13,14-dihydro-PGE1 to 15-keto-13,14-dihydro-PGE2 (0.17-1.39, median 0.41 vs. 0.2-1.17, median 0.45, P = 0.29). These results indicate that the endogenous formation of both PGE1 and PGE2 is normal in our patients. The results do not confirm the pivotal role that other authors have attributed to a deficient PGE1 formation in the pathogenesis of atopic dermatitis.

Adolescent↗
PubMed1996

Mycophenolate mofetil in patients with acute renal failure: evidence of metabolite (MPAG) accumulation and removal by dialysis.

Pharmacokinetics of mycophenolic acid (MPA) was analyzed in eight patients with post-transplant acute renal failure. Furthermore, the effect of hemodialysis upon blood levels of MPA and its major metabolite, MPA glucuronide (MPAG), was determined. The mean duration of the posttransplant renal failure was 18 days, but renal function resumed in all patients eventually. The patients were treated with 3 g/day of mycophenolate mofetil for 28 consecutive days combined with cyclosporine A, methylprednisolone, and ATG for induction therapy. In all patients, accumulation of MPAG but not of MPA was observed. MPA trough levels were in the range between 0.5 microgram/ml at day 2 and 2.3 micrograms/ml at the end of the study period. However, this concentration difference did not reach statistical significance. Trough levels of MPAG accumulated, reaching levels as high as 358 micrograms/ml. However, with increasing recovery of renal function, MPAG levels fell to a median trough concentration of 141 micrograms/ml. MPAG, but not MPA, could partially be removed from the circulation by hemodialysis treatment.

Acute Kidney Injury↗
PubMed1995

[The quantitative determination of the protein content of milk by means of violet spectral photometry. 7. The milk analyzer MAG 100 (Carl Zeiss Jena GmbH)--a possibility for simultaneous measurement of protein and fat content in raw milk at the dairy farm].

A new analysing apparatus is introduced, which allows to measure protein and fat contents of milk in the dairy farm. The instrument works on the basis of ultraviolet spectral photometry. Before measuring the milk sample must be diluted with a hydrous detergent solution in the ratio 1:100 and then homogenized. Accuracy and precision of the analytic results are influenced by detergent type, the water quality of detergent solution, the detergent foam, the air content and the pH of detergent solution, the reliability of homogenizer and thermostating system, the stability of photometer and by the error of dosage. Also a milk standard was developed, which is required for daily calibration of the apparatus.

Animals↗
PubMed1995

FK 506 versus cyclosporin in the prevention of renal allograft rejection--European pilot study: six-week results.

FK 506 was compared with cyclosporin in a randomised trial in good-risk cadaveric renal transplant recipients. The objective was to evaluate whether oral FK 506 dosing was viable and whether blood concentrations in the range 10-20 ng/ml would prove to be practical. Thirty-one adult patients were randomised to FK 506 and 16 to cyclosporin. Both groups received an identical regimen of azathioprine and corticosteroids. Serum creatinine concentrations decreased rapidly in both groups with mean values below 200 mumol/l within 2 weeks. One graft in the cyclosporin group was lost due to renal vein thrombosis. During the 6-week study period, 19.4% of patients on FK 506 and 31.3% on cyclosporin experienced acute rejection. One patient in each group experienced corticosteroid-resistant rejection that responded to anti-lymphocyte therapy. Infections were reported in 51.6% of the FK 506 group compared with 37.5% of the cyclosporin group. The spectrum of adverse events was similar in both groups. However, minor neurological disorders were more common in the FK 506 group (54.8% versus 6.3%) whereas hypertension was less common (48.8% versus 75.0%). The results indicate that oral FK 506 rapidly achieves therapeutic blood concentrations and is an effective immunosuppressant for the initial treatment of renal allograft recipients.

Adolescent↗
PubMed1995

Effective fragment potentials and spectroscopy at enzyme active sites.

Spectroscopy at a biochemical active site is influenced by local fields and hydrogen-bonds. Quantum calculations of the electronic structure of the entire biomolecule is, of course, impossible, but the chemical system can be modeled by dividing it into an active region (A) described quantum mechanically, and a spectator region (S) that influences A with strong fields and hydrogen-bonds. The all-electron interaction between A and S is replaced by an effective fragment potential (EFP) which represents the interaction as electrostatic, polarization and exchange repulsion terms. The EFP are derived entirely by ab initio model calculations of the S electronic properties and interactions and have been implemented in the quantum chemistry code, GAMESS. Spectroscopic analysis of enzyme active sites using the EFP will examine rhodanese and glutathione bound to glutathione S-transferase. The effect of specific hydrogen-bonds and local helices on spectral shifts is determined.

Amino Acid Sequence↗
PubMed1994

Jejunal obstruction as a late result of neonatal jejunal atresia.

The authors report on two adults who had jejunal dilatation after having had resection for jejunal atresia in the neonatal period. Both patients presented 20 years after the initial procedure, with severe iron deficiency anemia, marked jejunal dilatation proximal to the old anastomotic site (which was not narrowed), and a bezoar within the dilated segment. Upper gastrointestinal series were used to evaluate both patients before surgical resection of the enlarged intestine, with subsequent correction of the anemia.

Adult↗
PubMed1994

Tetrasomy 8 as a clonal anomaly in myeloid neoplasias.

Tetrasomy of chromosome 8 as a sole anomaly is apparently extremely rare in acute non-lymphocytic leukemia (ANLL): Only two cases have been reported, one of ANLL (M5b) with this karyotype. Very recently, another case was reported of a myelodysplastic syndrome (MDS) with isolated tetrasomy 8. We report tetrasomy 8 in four cases of ANLL, two of them with M5 and one with M1 subtype. Although in the latter case, tetrasomy 8 was evident in all karyotypes analyzed, in all other cases it constituted a subpopulation of cells other than those with trisomy 8 and those with a normal karyotype (in only one case another change was evident in the karyotype). Using fluorescence in situ hybridization (FISH), the proportion of tetrasomic cells was determined in interphase nuclei. By this technique, small cell populations (3-9%) were detected in three additional trisomy cases. An additional "control" group of five trisomy cases did not show a significant population of tetrasomic interphase nuclei. The data show that tetrasomy 8, if present as a sole anomaly in ANLL, may play a rather specific role for the subtype, and probably for the progression of myeloid neoplasia as well.

Adult↗
PubMed1994

Dynamic three-dimensional echocardiographic imaging of congenital heart defects in infants and children by computer-controlled tomographic parallel slicing using a single integrated ultrasound instrument.

Three-dimensional cardiac reconstruction generated from transesophageal interrogation can be performed using an integrated unit that captures, processes, and postprocesses tomographic parallel slices of the heart. This probe was used for infants and young children in the transthoracic position to evaluate the feasibility of producing three-dimensional cardiac images with capability for real-time dynamic display. Twenty-two infants and children (range 1 day-3.5 years) underwent image acquisition using a 16 mm 5 MHz 64 element probe placed over the precordium. Two infants were also imaged from the subcostal position. Data was obtained and stored over a single cardiac cycle after acceptable cardiac and respiratory gating intervals were met. The transducer was advanced in 0.5-1 mm increments over the cardiac structures using identical acquisition criteria. The images were reconstructed from the stored digital cubic format and could be oriented in any desired plane. In 9 of the 22 infants the images obtained were of optimal quality. The images obtained displayed normal cardiac structures emphasizing depth relationships as well as visualization of planes not generally demonstrated by two-dimensional imaging. Several lesions were also depicted in a unique fashion using this technique. Though the method employed was limited by movement artifact and reconstruction time, the quality of the three-dimensional display was excellent and enhanced by real-time demonstration. The transthoracic approach was successful in capturing sufficient data to create three-dimensional images, which may have further application in more accurate diagnosis of complex cardiac abnormalities and generation of planes of view which could duplicate surgical visualization of a lesion. Further assessment of the technique in infants with congenital heart disease is warranted.

Child, Preschool↗
PubMed1993

Late results of the surgical treatment of complete unilateral cleft lip and palate: soft tissue characteristics.

Sixty-one UCLP patients at 17-20 years of age treated in childhood by the same surgeon (Krauss) were invited for check-up examination to evaluate the late results of the surgical treatment. In the patients, the cleft lip was closed by a modified Le Mesurier procedure at 6-9 months of age and the cleft palate by a modified Veau procedure at 3-4 years of age. The "normal face" appearance showed 69% of the patients. More than one third of the population had successfully corrected nose deformities after the primary operation. In the most cases, the lip was also restored satisfactorily during the first treatment. Regular border between the lip and vermilion was observed in 62% of cases. The correct shape of hard palate was also found in 62% of the patients. The soft palate was well reconstructed in 92% of cases. In the most cases (95%), the speech was correct although the cleft palate was closed relatively late. The late results of the treatment can be considered satisfactory.

Adolescent↗
PubMed1990

Binding of cis(1,2-diaminocyclohexane)platinum(II) and its derivatives to duplex DNA.

A theoretical study is presented for the binding of RR, SS, SR, and RS isomers 1,2-diaminocyclohexane (DAC) or cis-PtII(DAC) to DNA. cis-PtII(DAC) is ligated to N7(G) on two adjacent intrastrand guanine bases in a kinked pentamer duplex of DNA (AT, CG*, CG*, GC, AT). The relative stability of the complexes is determined by calculating the relative conformational energy of the cis-PtII(DAC)(DNA) complexes with molecular mechanics (MM) and the intrinsic binding or ligation energy with quantum mechanics (QM). The results suggest that the RR and SS isomers of PtII(DAC) adducts with DNA are more stable than the SR/RS isomer by 1.7 kcal/mol relative to the cis-PtII(DAC(H2O)2 aquated species. Calculations on the overall stability of these isomers show that the SS and RR isomers are 6.5-8.2 kcal/mol more stable than the SR/RS isomers when bound to DNA, and this is attributed to differences in the strain energy in the DAC rings. The theoretical analyses of these compounds correlate a small differential activity with the trend in intrinsic binding energies. The RR isomer is more active in B16 melanoma cells, and the SS is most active in L1210 leukemia, and in general the RR and SS isomers are more active than the SR and RS in most cell types. The fact that the activity is DNA dependent suggests that excision or repair mechanisms may be taking place and that additional mechanistic steps beyond molecular modeling and quantum mechanical calculations are required to fully understand the activity. These studies of molecular fit of cis-PtII(DAC) to DNA are used to suggest substituted DAC compounds that may yield similar binding characteristics. Modifications to yield DAC derivatives are recommended in anticipation that they may also exhibit activity.

Antineoplastic Agents↗