Biomedical subjects

K Klein

Publications and source records attributed to K Klein.

At least 19 recordsLinked to original sources

PubMed2006

Flux through a hole from a shaken granular medium.

We have measured the flux of grains from a hole in the bottom of a shaken container of grains. We find that the peak velocity of the vibration, v max, controls the flux, i.e., the flux is nearly independent of the frequency and acceleration amplitude for a given value of v max. The flux decreases with increasing peak velocity and then becomes almost constant for the largest values of v max. The data at low peak velocity can be quantitatively described by a simple model, but the crossover to nearly constant flux at larger peak velocity suggests a regime in which the granular density near the container bottom is independent of the energy input to the system.

Journal Article↗

PubMed2006

Granular materials: packing grains by thermal cycling.

A long-standing problem in managing the behaviour of a collection of solid grains concerns the nature of the grain packing, a property that is typically controlled by how the grains are poured or shaken. Here we show that a systematic and controllable increase in granular packing can be induced by simply raising and then lowering the temperature, without the input of mechanical energy. This thermal processing may have important practical implications for the handling and storage of granular materials.

Journal Article↗

PubMed2005

[Structural quality of neurologic rehabilitation clinics].

BACKGROUND: In 2003, criteria for assessing the structural quality of rehabilitation units for inpatient treatment were developed in cooperation with the German statutory pension insurance and health insurance. The aim of this study was to assess this quality using predefined valuation criteria and to test their applicability. METHODS: In the context of the Quality Assurance Programme for Rehabilitation provided by the German statutory health insurance, the structural quality of 18 neurological rehabilitation units was assessed applying the criteria for the first time. RESULTS: On average, the 18 rehabilitation units fulfilled 93.9% of the basic criteria. Despite this high proportion, variability in the degree of realisation in the individual rehabilitation units could be demonstrated. The basic criteria are realistic in respect to the structural requirements, without leveling out the differences between the centres. CONCLUSION: Assessing the structural quality of rehabilitation units on the basis of defined standards allows for a benchmark between units as well as for improvements within the individual units.

Germany↗

PubMed2005

Smokeless tobacco use among professional baseball players: survey results, 1998 to 2003.

OBJECTIVE: The use of smokeless tobacco (ST) (snuff and chewing tobacco) has long been associated with baseball in the USA. This article reviews six years of survey data from major and minor league baseball players to evaluate trends in tobacco use and quitting patterns over time in order to gain insight into the effects of past interventions and to document continued intervention needs. METHOD: Surveys were distributed by athletic trainers to major and minor league professional baseball players during spring training session in the six years from 1998 to 2003. The surveys were anonymous and identified only by team, level of league, and other self reported demographic data. RESULTS: ST use among professional baseball players remains much higher than among young males in the general population, and use is most prevalent among white non-Hispanic players. There was a significant decrease in ST use among minor league players from 1998 to 2003, with seven day self reported use declining from 31.7% in 1998 to 24.8% in 2003. No significant year to year changes were observed for major league players. Major league players' self reported past week use rates, estimated at 35.9% in 1998 and at 36% in 2003, were consistently higher than those of minor league players. Self reported prevalence of past month cigarette and cigar smoking was much lower than ST use for both major and minor league players. CONCLUSIONS: Six years of survey data confirm a continuing high use of ST among professional baseball players. Results suggest that the effects of the broad spectrum ST control efforts launched over the past decade may have been stronger among minor than major league players. Stronger policy interventions at the major league level and multi-level efforts, including programmes to increase the use of effective quitting aids and assistance, at both levels of play are needed. Future research is needed to further clarify changes in ST practices among professional players and set policy intervention directions.

Adolescent↗

PubMed2004

Associations of the UCP2 gene locus with asymptomatic carotid atherosclerosis in middle-aged women.

OBJECTIVE: Reactive oxygen species (ROS) contribute to atherogenesis. Uncoupling protein 2 (UCP2) reduces mitochondrial ROS generation and protects against the disease in animal models. A common -866G/A promoter polymorphism that has been associated with obesity and beta-cell function may also affect UCP2 gene expression in cells of the arterial wall. METHODS AND RESULTS: Genotype distributions of the -866G/A and of a 45nt-del/ins polymorphism in the 3'-untranslated region of the UCP2 gene were determined in 1334 participants of the Salzburg Atherosclerosis Prevention Program in Subjects at High Individual Risk (SAPHIR). We observed a modest association of the -866G/A promoter polymorphism and 2-loci haplotypes with asymptomatic carotid atherosclerosis in female study participants. Functional studies revealed increased expression of the -866G wild-type allele in human umbilical vein endothelial cells and differentiated THP-1 cells. Electrophoretic mobility shift assay studies and antibody-interference assays performed with nuclear extracts of various cell lines showed binding of cell-type specific protein complexes to the region encompassing the -866 site and suggested involvement of hypoxia inducible factor 1alpha in the regulation of UCP2 gene expression in endothelial cells and macrophages. CONCLUSIONS: Our results suggest a role of UCP2 in atherogenesis as originally proposed from studies in animal and cell culture models.

Adult↗

PubMed2004

[Criteria of quality of structure in rehabilitation units with inpatient treatment].

The structure of a rehabilitation unit is an important feature of the quality of care. Adequate and qualitatively good structures provide the basis for appropriate therapy offers and treatment and eventually, a better health for rehabilitants. The quality of structures is generally recorded without any evaluation of the aspects in particular. The definition of standards is the basis for such an evaluation. The project presented is aimed at the definition of relevant structural standards for rehab units with inpatient treatment for musculoskeletal, cardiac, neurological, gastroenterological, oncological, pneumological and dermatological diseases. Here, the distinction between basal criteria which have to be fulfilled by every rehab unit with inpatient treatment and criteria important for a well-aimed assignment of patients with specific needs ("assignment criteria") should be made. Apart from the documentation of structural attributes, the structural quality of a rehab unit can be described individually as well as in comparison with other units. Relevant structural criteria were defined in expert meetings by means of a modified Delphi-technique with five inquiries. Overall, 199 "basal criteria" and "assignment criteria" were defined. All criteria can be assigned to the two domains general structural characteristics (general characteristics and equipment of rooms; medical/technical equipment; therapy, education, care; staff) and process-related structures (conceptual frames; internal quality management; internal communication and personnel development). The structural standards are applicable to units for musculoskeletal, cardiac, neurological, oncological, gastroenterological, dermatological and pneumological rehabilitation financed by the two main providers of rehabilitation, the statutory pension insurance scheme and the statutory health insurance scheme for all other five indications. The definition of structural standards agreed by experts in a formal consensus process, provides comprehensive and concrete requirements for German rehab units with inpatient medical rehabilitation. If the two main providers of rehabilitation both use the standards this can be regarded as a hallmark on the path to a unitary programme for quality management. The results enable units to analyse their weak points not just on an individual basis but allow also for a comparison between units, along with contributing to optimizing the structural quality of rehab units.

Germany↗

PubMed2004

[Cranial sonography for newborn screening: a 10-year retrospective study in 11,887 newborns].

We retrospectively analyzed the results of a sonographic cranial screening study, performed between 1985 and 1994 to determine the incidence of intracranial hemorrhage and cerebral anomalies based on obstetrical risk factors. In the Department of Obstetrics and Gynecology of the University Giessen, Giessen, Germany, 94.6 % (n = 11,887) of all children born during the study period were included and underwent sonographic cranial screening within the first 10 days after birth. Cerebral abnormalities were found in 653 (= 5.5 %) cases, and peri-/intraventricular hemorrhages (PIVH, grade I-IV) in 303 cases. Periventricular leucomalacia, porencephaly, subarachnoidal hemorrhage and hydrocephaly were rare (< or = 0.2 %). The Apgar index proved to be a good prognostic factor, particularly at 1 and 5 minutes after birth (p < 0.0001). In contrast, correlation between PIVH and cardiotocography, arterial cord blood gases, and pH was poor. We did not observe a higher incidence of PIVH in newborns with growth retardation, preeclampsia and premature ruptures of membranes or prolonged labor. With decreasing gestational age, the frequency of PIVH increased progressively from 0.4 % at 39 weeks to 53.2 % at 27 weeks (p < 0.001). We also found a higher risk of intracranial hemorrhage in preterm newborns with amniotic infections (38.1 %, p < 0.001). In mature babies, we did not find a difference between the incidence of PIVH and delivery-modes; however, we noted a higher risk of PIVH Grade IV in preterm newborns with breech presentation for vaginal delivery versus caesarean section (38.5 % versus 7.4 %, p = 0.005). The incidence of PIVH over this 10 year time period did not increase despite an increasing number of preterm newborns over time. In conclusion, this study, which represents one of the largest patient cohorts studied for PIVH, indicates that neonatal sonographic cranial screening is an important tool to define quality control in obstetrics.

Apgar Score↗

PubMed2002

Analysis of immunoregulatory T-helper cell subsets in patients with multiple sclerosis: relapsing-progressive course correlates with enhanced T H1, relapsing-remitting course with enhanced T H0 reactivity.

In this study, we analysed the recall antigen-induced cytokine production by peripheral blood mononuclear cells (PBMC) from 31 patients with multiple sclerosis (MS) with a relapsing-remitting (rr) and a relapsing-progressive (rp) course and from 40 healthy controls. Cells were stimulated with purified protein derivative (PPD; type 1 response) and tetanus toxoid (TT; type 2 response). Cytokines were determined in the supernatants by ELISA. One of the interesting findings was that healthy controls showed more frequently an IL-5 production after incubation with TT than MS-patients (68% vs.37%; p<0.01), while the type 1 reactivity was only slightly enhanced in MS patients as compared to the controls. However, within the MS patients, there was a significant difference in the incidence of the type 1 reactivity comparing patients with an rp and an rr course (60% vs. 24%; p<0.05). Furthermore, the frequency of a type 0 profile (simultaneous PPD-induced IFN-gamma and TT-induced IL-5 production) was fourfold higher in rr than in the rp patients (43% vs. 10%, p<0.05). In vitro analysis of cytokine profiles in MS could therefore be an interesting approach to evaluate the prognosis of MS (rr vs. rp) already at the beginning of the disease. Thus, it seems that the presence of a type 0 profile is a valid indicator for a favorable course, while a type 1 profile is rather associated with rp MS.

Adult↗

PubMed2002

Intergenerational transmission of somatization behaviour: a study of chronic somatizers and their children.

BACKGROUND: Exposure to an ill parent in childhood may be a risk factor for adult somatization. This study examines the hypothesis that somatizing adults are more likely to have been exposed to illness as a child and that in turn, their children are more likely to report ill health and to have more contact with medical services than children of other mothers. METHOD: A cross-sectional comparative investigation of three groups of mothers and their children of 4-8 years of age: (i) 48 mothers suffering from chronic somatization; (ii) 51 mothers with chronic 'organic' illness; and (iii) 52 healthy mothers was carried out. RESULTS: Somatizing mothers were more likely than other women to report exposure to childhood neglect and to physical illness in a parent (OR 2.9; 95% CI 1.4-6.1). The children of these somatizing mothers were more likely to have health problems than were the children of organically ill or healthy women and had more consultations with family doctors (average annual rates: somatizers 4.9 (S.D. 3.8), organic 3.0 (S.D. 3.5) and healthy 2.8 (S.D. 2.6)). Multivariate modelling of consultation rates among children found significant main effects for maternal somatization, maternal childhood adversity, the child's tendency to worry about health and a two-way interaction of maternal childhood adversity and her somatization status. CONCLUSIONS: The hypotheses are broadly supported. However, it is important to emphasize the extent to which these findings are based on maternal reports.

Adolescent↗

PubMed2001

Expressive writing can increase working memory capacity.

The effect of emotional disclosure through expressive writing on available working memory (WM) capacity was examined in 2 semester-long experiments. In the first study, 35 freshmen assigned to write about their thoughts and feelings about coming to college demonstrated larger working memory gains 7 weeks later compared with 36 writers assigned to a trivial topic. Increased use of cause and insight words was associated with greater WM improvements. In the second study, students (n = 34) who wrote about a negative personal experience enjoyed greater WM improvements and declines in intrusive thinking compared with students who wrote about a positive experience (n = 33) or a trivial topic (n = 34). The results are discussed in terms of a model grounded in cognitive and social psychological theory in which expressive writing reduces intrusive and avoidant thinking about a stressful experience, thus freeing WM resources.

Adaptation, Psychological↗

PubMed2001

Mycosis fungoides: HLA class II associations among Ashkenazi and non-Ashkenazi Jewish patients.

BACKGROUND: An immunogenetic mechanism has been suggested to play a role in the pathogenesis of mycosis fungoides (MF). While results of studies on HLA class I associations haveproved inconsistent, two previous studies showed that certain HLA class II alleles were significantly increased among North American caucasian patients with MF: HLA-DRB1*11 and DQB1*03. OBJECTIVES: To investigate the possible HLA class I and class II associations with MF among Jewish patients. METHODS: The patient group comprised 68 Jewish patients with MF: 38 Ashkenazi and 30 non-Ashkenazi. The control group comprised 252 healthy Jewish volunteers: 132 Ashkenazi and 120 non-Ashkenazi. Tissue typing for HLA class I (A and B) was performed using the National Institutes of Health microlymphocytotoxicity technique. DNA-based low-medium resolution analysis for DRB1* and DQB1* alleles was performed using polymerase chain reaction (PCR) amplification with sequence-specific primers. For those alleles found to have significantly increased frequency, high-resolution analysis was done by means of PCR sequence-specific oligotyping. RESULTS: The allele frequency of HLA-DRB1*11 was found to be significantly increased but only among Ashkenazi patients with MF (30% vs. 19% in the controls; P = 0.034). High-resolution analysis for DRB1*11, not previously performed, suggested that its greater frequency is due to the increased number of Ashkenazi MF patients with the DRB1*1104 allele (P corrected = 0.036). Analysed together, DQB1*03 alleles (DQB1*0301-0304) had a significantly greater frequency in MF as a group as compared with controls (47% vs. 33%, P = 0.003). DQB1*0301 was demonstrated to be the specific allele associated with MF in Jewish patients (allele frequency of 36% vs. 23% in controls; P corrected = 0.0068), which was not the case for North American caucasian patients with MF. No greater frequencies of any of the HLA class I A or B antigens were found. CONCLUSIONS: Our findings further demonstrate the 'universality' of MF HLA class II susceptibility alleles, i.e. HLA-DRB1*11 and HLA-DQB1*03, suggesting that HLA polymorphism is likely to be important in the pathogenesis of MF in Jewish patients, as it is in North American caucasian patients. Not previously reported is our finding that HLA-DRB1*1104 is the specific allele more prevalent among patients with MF. Our study also underscores some differences in HLA profiles between non-Jewish and Jewish patients with MF and between Ashkenazi and non-Ashkenazi Jewish patients, indicating the possibility of diverse HLA disease associations in populations with different genetic backgrounds. Our study provides further evidence for the lack of association between HLA class I and MF.

Case-Control Studies↗

PubMed2001

Extensive genetic polymorphism in the human CYP2B6 gene with impact on expression and function in human liver.

The human cytochrome P450, CYP2B6, is involved in the metabolism of several therapeutically important drugs and environmental or abused toxicants. In this study, we present the first systematic investigation of genetic polymorphism in the CYP2B6 gene on chromosome 19. A specific direct sequencing strategy was developed based on CYP2B6 and CYP2B7 genomic sequence information and DNA from 35 subjects was completely analysed for mutations throughout all nine exons and their exon-intron boundaries. A total of nine novel point mutations were identified, of which five result in amino acid substitutions in exon 1 (C64T, Arg22Cys), exon 4 (G516T, Gln172His), exon 5 (C777A, Ser259Arg and A785G, Lys262Arg) and exon 9 (C1459T, Arg487Cys) and four are silent mutations (C78T, G216C, G714A and C732T). Polymerase chain reaction-restriction fragment length polymorphism tests were developed to detect each of the five nonsynonymous mutations in genomic DNA. By screening a population of 215 subjects the C64T, G516T, C777A, A785G and C1459T mutations were found at frequencies of 5.3%, 28.6%, 0.5%, 32.6% and 14.0%, respectively. Haplotype analysis revealed six different mutant alleles termed CYP2B6*2 (C64T), *3 (C777A), *4 (A785G), *5 (C1459T), *6 (G516T and A785G) and *7 (G516T, A785G and C1459T). By analysing a large number of human liver samples, significantly reduced CYP2B6 protein expression and S-mephenytoin N-demethylase activity were found in carriers of the C1459T (R487C) mutation (alleles *5 and *7). These data demonstrate that the extensive interindividual variability of CYP2B6 expression and function is not only due to regulatory phenomena, but also caused by a common genetic polymorphism.

Aryl Hydrocarbon Hydroxylases↗

PubMed2001

The genetic determinants of the CYP3A5 polymorphism.

CYP3A proteins comprise a significant portion of the hepatic cytochrome P450 (CYP) protein and they metabolize around 50% of drugs currently in use. The dissection of the individual contributions of the four CYP3A genes identified in humans to overall hepatic CYP3A activity has been hampered by sequence and functional similarities. We have investigated the expression of CYP3A5 and its genetic determinants in a panel of 183 Caucasian liver samples. CYP3A5 expression is increased in 10% of livers in this ethnic group. Using a high density map of CYP3A5 variants, we searched for genetic markers of the increased CYP3A5 expression. In agreement with an independent, recent study, we report that a SNP within intron 3 (g.6986G>A) is the primary cause of the CYP3A5 protein polymorphism. The frequencies of the g.6986A variant which allow for normal splicing of CYP3A5 transcripts are 5% in Caucasians, 29% in Japanese, 27% in Chinese, 30% in Koreans and 73% in African-Americans. In the last ethnic group, the expression of CYP3A5 in some individuals who carry the g.6986A variant is affected adversely by a frame shift mutation (CYP3A5*7, D348., q = 0.10). In summary, these results should add to efforts to identify clinically relevant, CYP3A5-specific reactions and to further elucidate traits responsible for variable expression of the entire CYP3A family.

Alternative Splicing↗

PubMed2001

Improving performance at the local level: implementing a public health learning workforce intervention.

In an effort to continually improve performance of the essential public health services with community partners, the diverse public health workforce in a major metropolitan area engaged in an organizational learning process. Core public health organizational competencies, identified in a multi-year collaborative applied research initiative, provided the curricula content for the public health learning experience. All members (about 600) of the Columbus and Franklin County (Ohio) Health Departments participated in four one-half day small group, highly interactive modules conducted during a 2-year period. The purpose of this article is to describe the design and implementation of this workforce intervention, the lessons learned, and implications for developing organizational capacity and improved performance.

Competency-Based Education↗

PubMed2001

Comparison of different approaches to quantify Staphylococcus aureus cells by real-time quantitative PCR and application of this technique for examination of cheese.

Two different real-time quantitative PCR (RTQ-PCR) approaches were applied for PCR-based quantification of Staphylococcus aureus cells by targeting the thermonuclease (nuc) gene. Purified DNA extracts from pure cultures of S. aureus were quantified in a LightCycler system using SYBR Green I. Quantification proved to be less sensitive (60 nuc gene copies/microl) than using a fluorigenic TaqMan probe (6 nuc gene copies/microl). Comparison of the LightCycler system and the well-established ABI Prism 7700 SDS with TaqMan probes revealed no statistically significant differences with respect to sensitivity and reproducibility. Application of the RTQ-PCR assay to quantify S. aureus cells in artificially contaminated cheeses of different types achieved sensitivities from 1.5 x 10(2) to 6.4 x 10(2) copies of the nuc gene/2 g, depending on the cheese matrix. The coefficients of correlation between log CFU and nuc gene copy numbers ranged from 0.979 to 0.998, thus enabling calculation of the number of CFU of S. aureus in cheese by performing RTQ-PCR.

Benzothiazoles↗

PubMed2001

The appeal cycle in three cultures: an exploratory comparison of child development.

Mother-child behaviors were studied in three cultural groups: Caucasian American (CA), overseas Japanese (JPN), and Chinese Vietnamese (CVN) immigrants. The children were sixteen to twenty-five months old, and the appeal cycle, with its descriptive analytic method, was the research paradigm. Group differences were found in appeal cycle occurrence and phase frequencies. CA mothers promoted independence through encouragement of decision making and toddler-initiated play, and through nonintrusive interactions. Neither JPN nor CVN mothers encouraged independence. JPN mothers were subtly directive; CVN mothers overtly so. Generally, CA toddlers played independently, evincing a beginning capacity for self-regulation. JPN and CVN toddlers reacted to separation by staying close to their mothers, and fewer were observed to play independently than in the CA group. CVN toddlers played independently more frequently than JPN toddlers, but less frequently than CA toddlers. Quantitative measures of dyadic behaviors generally support the descriptive findings, though methodological constraints did not permit comparison of phase sequencing. The findings reflect cultural differences in child development thought to influence psychic structure formation.

Adult↗

PubMed2001

[Relationship between the tendon of the long head of the biceps brachii muscle and the glenoid labrum].

For many authors, the insertion of the long head of the biceps brachii muscle is exclusively or mainly located on the supraglenoid tubercle. The aim of this work was to study the insertion of the long head of the biceps brachii at macroscopic and microscopic examinations. 31 shoulders of macerated cadavers of both sex (age range: 52-92 years) were dissected by a posterior approach in order to study the glenoid labrum and the origin of the long head of the biceps brachii muscle. At macroscopic examination two types of the proximal part of the long head of the biceps brachii were demonstrated: a flattened shape in 84% of the cases and a hemicylindrical shape in 16% of the cases. Four types of origin were demonstrated at dissection: in 64.5% of the cases the tendon inserted mainly on the postero-superior part of the labrum, in 19.4% of the cases the tendon inserted both on the postero-superior and postero-anterior labrum, in 6.4% of the cases it inserted only on the supraglenoid tubercle and in three cases the tendon inserted on the intertubercular groove. The histologic examination performed on 6 superior part of the bicipitolabral complex have all shown that the tendinous fibers blended with the glenoid labrum. The examination performed on an complete labrum demonstrated tendinous fibers within the glenoid labrum up to the junction between the postero-superior and postero-inferior part of the labrum.

Aged↗

PubMed2000

Exercise-trained young men have higher calcium absorption rates and plasma calcitriol levels compared with age-matched sedentary controls.

The effect of physical activity on human calcium (Ca) metabolism is still not completely understood. Thus, we investigated fractional Ca absorption using a stable strontium test (Fc(240)), calciotropic hormones, and renal Ca excretion in 31 young men with a high activity level (GH) and in 26 age-matched sedentary control subjects (GL). Weekly hours spent on physical activity, obtained with a questionnaire were 15.0 +/- 6.6 (GH) and 1.0 +/- 1.4 (GL), respectively. Serum testosterone levels were significantly lower in GH compared with GL (P < 0.005). Dietary Ca intake (4-day food record) was twice as high in GH compared with GL men (P < 0.001). GH had significantly higher serum calcitriol levels and Fc(240) values than GL (P < 0.001 and P < 0.01, respectively). In a stepwise multiple regression analysis including serum levels of 25-hydroxyvitamin D, calcitriol, testosterone, and dietary Ca intake, only calcitriol was significantly correlated with Fc(240) (P = 0. 017). Twenty-four hour renal Ca excretion was only slightly higher in GH compared with GL (P < 0.05). However, additional Ca losses might have occurred through the extensive sweating of GH, as indicated by a difference of 1.7 liter between fluid intake and renal fluid excretion (P < 0.001). In summary, we observed a higher fractional Ca absorption rate in physically active young men compared with sedentary controls which is probably mediated by calcitriol. The low testosterone serum levels of the athletes were obviously not a limiting factor in Ca absorption efficiency. An additional Ca retention might, however, only be obtained if absorbed Ca exceeded total obligatory Ca losses.

Adult↗