Biomedical subjects

R Kraus

Publications and source records attributed to R Kraus.

At least 19 recordsLinked to original sources

PubMed2007

[Intraoperative radiation exposure in elastic stable intramedullary nailing (ESIN) during the growth period. Observations in 162 long bone shaft fractures].

BACKGROUND: The increase of intraoperative radiation exposure in intramedullary techniques of osteosynthesis is recognised and accepted in adults especially in interlocked nailing. In contrast data about fluoroscopy times in elastic stable intramedullary nailing (ESIN) in children and adolescents are hardly available. MATERIAL AND METHOD: Operation records of 162 surgical procedures (8.6% humerus, 43.8% forearm, 32.7% femur, 14.8% lower leg) of a 3-year period were evaluated retrospectively. The mean age was 6.1 years in femoral shaft fractures, nearly similar in forearm and lower leg fractures (8.7 and 7.9 years, respectively) and 12.4 years in patients with humeral shaft fractures. RESULTS: Mean operation (OP) and fluoroscopy times (FL) were increased in humeral fractures (58.1 min OP, 1.62 min FL), at a medium level in forearm fractures (35.2 min OP, 1.06 min FL) and femoral fractures (42.3 min OP, 1.27 min FL) and shortest in lower leg fractures (29.6 min OP, 0.69 min FL). CONCLUSION: Our results and literature analysis show that optimal technical conditions, especially the use of a pulsed image intensifier and well-trained theatre staff, are able to reduce intraoperative radiation load.

Body Burden↗

PubMed2006

[Distraction osteogenesis for adjusting humeral length difference due to premature closure of the proximal growth plate in a simple bone cyst].

Complications after pathological fractures of simple bone cysts of the humerus are refracture, cyst recurrence, and in rare cases premature closure of the physeal plate with resulting shortening of the arm. Length discrepancies of the lower limbs beyond physiological limits need early compensation in children as well as adults to avoid interference with the pelvis and spine. However, surgical treatment of length differences of the humerus is usually cosmetic, because even considerable discrepancies do not lead to functional deficits. We report the long-term course of a complicated bone cyst of the proximal humerus and resolving a severe length difference of 7 cm by distraction osteogenesis in a young adult. The cause of the premature physeal closure and the primary therapeutical concept are discussed.

Adolescent↗

PubMed2006

[School accidents--an epidemiological assessment of injury types and treatment effort].

Children and adolescents spend up to 50% of their time at school. The purpose of this study was to assess injury patterns with their treatment of school accidents in a Trauma Service of a German University Hospital and to compare these data to the literature. All school accidents from 01.07.1999 to 30.06.2004 were statistically analysed in a retrospective manner by chart review. There were 1399 school accidents treated in our department. Average age of the injured children was 11.8 years with a boy:girl ratio of 3:2. Almost 40% of the injuries occurred during school sport. The most frequently injured region was the upper extremity including the hand (36.8%). Distortion and contusion were the most frequent diagnoses of all injuries. 16% of the cases had to be treated surgically and/or under general anaesthesia and also a total of 16% of the patients had to be admitted to the hospital. It can be concluded for school facilities that special attention has to be paid during school sports activity and breaks because they account for most accidents. Traffic education may reduce severe injuries. For diagnosis and treatment of school accidents specific knowledge of the growing longbones of the upper extremity and the hand is important.

Accidents↗

PubMed2006

Rare incidence of pulmonary gangrene--algorithm of the treatment.

The pulmonary gangrene is rare and serious disease. Our experience is based on the treatment of the 2 patients with pulmonary gangrene during the last twenty years. The first and lifesaving step in the treatment of sepsis is the early removal of the necrotic tissue. Next surgery succeeds usually after one week after initial treatment. Surgical treatment continues step by step, we do not advise providing of a major anatomical resection in the initial stage of the disease. This policy is effective in the treatment of this serious disease.

Algorithms↗

PubMed2005

[Covering of soft tissue defects of the lower leg with adipo-facial flaps].

AIM OF THE STUDY: Soft tissue covering on the lower leg is a difficult challenge. A plastic surgical method for covering of these soft tissue defects is presented. PATIENTS AND METHODS: From May 1997 until May 2003 36 patients were treated using neurovascular flaps. Above the sural or the saphenous nerve an adipo-facial flap is dissected, rotated into the defect and fixed without tension. Wound closure of the donor-site defect is done primarily or by mesh-graft. RESULTS: In 35 cases the flap healed without functional impairment. Primary healing was achieved in 30 patients. In 5 cases partial loss of the skin island was registered, whereby subcutaneous tissue remained vital. Revision by mesh-graft transplantation led to successful healing in these patients. In only one patient necrosis of the flap was seen. CONCLUSION: Neurovascular flaps usually result in reliable and complete healing of soft tissue defects of the lower extremity.

Adolescent↗

PubMed2005

[Fractures of the scaphoid tubercle].

BACKGROUND: Avulsion fractures of the scaphoid tubercle (Herbert type A1) are rare. Recommendations in the literature focus on a four to six week plaster immobilization including the thumb. Surgery is recommended in case of additional injuries to the carpus. MATERIAL AND METHODS: In a retrospective investigation including a 36 month period we reviewed acute fractures of the scaphoid and avulsion fractures of the scaphoid tubercle. RESULTS: We found 81 acute scaphoid fractures, four of them (4.9 %) were isolated tuberculum avulsions. Three cases were extra-, one case an intraarticular fracture. The first were treated conservatively, the last with a percutaneous screw. CONCLUSIONS: Following our own experiences with those rare injuries we recommend a differentiation of the fracture type into extraarticular injuries where conservative treatment should still be performed and intraarticular fractures where percutaneous screw osteosynthesis should be discussed.

Acute Disease↗

PubMed2005

[The arteries of the humerus and their relevance in fracture treatment].

BACKGROUND: The purpose of the current work was to study the arterial blood supply of the humerus to evaluate impairments of the blood supply after humeral fractures and different methods of fracture treatment. METHODS: Arterial blood supply of the humerus was studied by corrosion injection technique in 6 cadaver preparations and is compared with the existing literature. RESULTS: Humeral head arteries originate from the circumflex humeral arteries. The major vessel enters the greater tubercle. Another group of vessels accesses the head from medially. The nutrient artery for the shaft enters into the medial third of the shaft. At the distal humerus there are multiple anastomoses with penetrating branches into both condyles and proximal to the radial, coronoid, and olecranon fossae. CONCLUSIONS: Fragments of a proximal humeral fracture usually have an independent blood supply. The medial vessels to the head gain high importance in fractures of the anatomical neck. The nutrient artery lies regularly medial to the humeral mid-shaft and is at risk at open reduction of this region. The abundant vessels at the entire distal humerus ensure sufficient vascularization of the fragments after fracture.

Arteries↗

PubMed2003

[Operative treatment of extended peritendinous calcifications after open Achilles tendon repair-a case report].

In the recent literature, there are only a few hints on spontaneous or postoperative heterotopic ossifications of the Achilles tendon region. The strategies of treatment are different, both conservative and operative. Postoperative calcifications are not mentioned as typical complications in the treatment of Achilles tendon ruptures. We describe the case of a 39 year old male suffering of an increasing, painful swelling and a decrease of loading capacity. In clinical, sonographic and radiological investigations,we found large peritendinous calcifications ventral to the intact heel tendon up to 36 mm in diameter. After operative resection of the calcifications and postoperative chemical prophylaxis, the patient has been without pain for 1 year. There was no relapse of the calcifications or re-rupture of the tendon.

Achilles Tendon↗

PubMed2002

Aseptic necrosis of both femoral heads as first symptom of chronic myelogenous leukemia.

Chronic myelogenous leukemia (CML) is a disease of the elderly; in rare cases it occurs in childhood or adolescence. One complication at primary diagnosis is leukostasis, which usually causes respiratory, retinal, or central nervous symptoms. In this report we describe the case of a 24-year-old woman who developed aseptic necrosis of both femoral heads, which was successfully treated by bore holes in the femoral heads. This is a very rare complication of severe leukostasis, leading to the diagnosis of CML in this case. To our knowledge, this is the first case of an adult patient showing aseptic necrosis of femoral heads caused by leukostasis.

Adult↗

PubMed2002

Interventions aimed at improving immunization rates.

BACKGROUND: Immunization rates for children and adults are rising, but coverage levels have not reached national goals. As a result of low immunization rates, vaccine-preventable diseases still occur. In an era of increasing complexity of immunization schedules, rising expectations about the performance of primary care, and large demands on primary care physicians, it is important to understand and promote interventions that work in primary care settings to increase immunization coverage. A common theme across immunization programs in all nations involves the challenge of determining the denominator of eligible recipients (e.g., all children who should receive the measles vaccine), and identifying the best strategy to ensure high vaccination rates. Strategies have focused on patient-oriented interventions (e.g., patient reminders), provider interventions, and system interventions. One intervention strategy involves patient reminder/recall systems. OBJECTIVES: Assess the effectiveness of patient reminder/recall systems in improving immunization rates, and compare the effects of various types of reminders in different settings or patient populations. SEARCH STRATEGY: A systematic search was performed using MEDLINE (1966-1998) and 4 other bibliographic databases: EMBASE, PsychINFO, Sociological Abstracts, and CAB Abstracts. Authors also performed a search of EPOC in April 2001 to update the review. Two authors reviewed the lists of titles and abstracts, and used the inclusion criteria to mark potentially relevant articles for full review. The reference lists of all relevant articles and reviews were back searched for additional studies. Publications of abstracts, proceedings from scientific meetings, and files of study collaborators were also searched for references. SELECTION CRITERIA STUDY DESIGN: Randomized controlled trials (RCT), controlled before and after studies (CBA), and interrupted time series (ITS) studies written in English. TYPES OF PARTICIPANTS: Health care personnel who deliver immunizations and children (birth to 18 years) or adults (18 years and up) who receive immunizations in any setting. Types of interventions: Any intervention that falls within the Effective Practice and Organization of Care Group (EPOC) scope and that includes patient reminder and/or recall in at least one arm of the study. Types of outcome measures: Immunization rates, or the proportion of the target population up-to-date on recommended immunizations. Outcomes were acceptable for either individual vaccinations (e.g., influenza vaccination) or standard combinations of recommended vaccinations (e.g., all recommended vaccinations by a specific date or age). DATA COLLECTION AND ANALYSIS DATA COLLECTION: Each study was read independently by two reviewers. Disagreements between reviewers were resolved by a formal reconciliation process to achieve consensus. ANALYSIS: Results are presented for individual studies as relative rates for randomized controlled trials, and as absolute changes in percentage points for controlled before and after studies. Pooled results were presented using the random effects model. MAIN RESULTS: Patient reminder/recall systems were effective in improving immunization rates in 33 of 41 included studies, irrespective of baseline immunization rates, patient ages, type of setting, or type of vaccination. Increases in immunization rates due to reminders were in the range of 5 to 20 percentage points. Reminders were effective for childhood vaccinations (OR=2.02, 95% CI =1.49,2.72), childhood influenza vaccinations (OR=4.19, 95% CI =2.07,8.49), adult pneumococcus or tetanus (OR=5.14, 95%CI = 1.21, 21.8), and adult influenza vaccinations (OR=2.29, 95%CI = 1.69, 3.10). While reminders were most effective in academic settings (OR = 3.33, 95% CI = 1.98, 5.58), they were also highly effective in private practice settings (OR=1.79, 95% CI = 1.45, 2.22) and public health clinics (OR = 2.09, 95% CI = 1.42, 3.07). All types of reminders were effective (postcards, letters, telephone or autodialer calls), with telephone being the most effective but most costly. REVIEWER'S CONCLUSIONS: Patient reminder/recall systems in primary care settings are effective in improving immunization rates.

Humans↗

PubMed2001

Association of mitral annulus calcification, aortic valve sclerosis and aortic root calcification with abnormal myocardial perfusion single photon emission tomography in subjects age < or =65 years old.

OBJECTIVES: We examined the hypothesis that mitral annulus calcification (MAC), aortic valve sclerosis (AVS) and aortic root calcification (ARC) are associated with coronary artery disease (CAD) in subjects age < or =65 years. BACKGROUND: Mitral annulus calcification, AVS and ARC frequently coexist and are associated with coronary risk factors and CAD in the elderly. METHODS: We studied 338 subjects age < or =65 years who underwent evaluation of chest pain with myocardial perfusion single photon emission computed tomography (SPECT) and a two-dimensional transthoracic echocardiogram for other indications. The association of MAC, AVS and ARC with abnormal SPECT was evaluated by using chi-square analyses and logistic regression analyses. RESULTS: Compared with no or one calcium deposit and no or one coronary risk factor other than diabetes, multiple (> or =2) calcium (or sclerosis) deposits with diabetes or multiple (> or =2) coronary risk factors were significantly associated with abnormal SPECT in women age < or =55 years old (odds ratio [OR], 20.00), in women age >55 years old (OR, 10.00) and in men age < or =55 years old (OR, 5.55). Multivariate analyses identified multiple calcium deposits as a significant predictor for an abnormal SPECT in women (p < 0.001), younger subjects age < or =55 years (p < 0.05) and the total group of subjects (p < 0.01). CONCLUSIONS: When coronary risk factors are also taken into consideration, the presence of multiple calcium deposits in the mitral annulus, aortic valve or aortic root appears to be a marker of CAD in men < or =55 years old and women.

Aged↗

PubMed2001

Delta13C and deltaD values of Opuntia atacamensis depending on different environmental conditions in the Atacama desert of Northern Chile.

We analysed 13carbon and deuterium discrimination in Opuntia atacamensis PHIL. at three different sites in the Atacama desert in Northern Chile: At the western Andean slopes, influenced by summer rainfall, in the very arid Chilean central valley, and at coastal fog mountains. At the most arid site, the central valley, discrimination of 13C and D was less (delta-values less negative) and also discrimination more against deuterium. This is an aridity, not an altitude effect. The differences in 13C content may be due to some carbon fixation via the C3 photosynthetic pathway at the more humid sites. Deuterium enrichment at the arid sites might be due to greater discrimination of HDO against H2O during transpirational water loss.

Adaptation, Physiological↗

PubMed2000

Molecular determinants of inactivation in voltage-gated Ca2+ channels.

Evolution has created a large family of different classes of voltage-gated Ca2+ channels and a variety of additional splice variants with different inactivation properties. Inactivation controls the amount of Ca2+ entry during an action potential and is, therefore, believed to play an important role in tissue-specific Ca2+ signalling. Furthermore, mutations in a neuronal Ca2+ channel (Ca(v)2.1) that are associated with the aetiology of neurological disorders such as familial hemiplegic migraine and ataxia cause significant changes in the process of channel inactivation. Ca2+ channels of a given subtype may inactivate by three different conformational changes: a fast and a slow voltage-dependent inactivation process and in some channel types by an additional Ca2+-dependent inactivation mechanism. Inactivation kinetics of Ca2+ channels are determined by the intrinsic properties of their pore-forming alpha1-subunits and by interactions with other channel subunits. This review focuses on structural determinants of Ca2+ channel inactivation in different parts of Ca2+ channel alpha1-subunits, including pore-forming transmembrane segments and loops, intracellular domain linkers and the carboxyl terminus. Inactivation is also affected by the interaction of the alpha1-subunits with auxiliary beta-subunits and intracellular regulator proteins. The evidence shows that pore-forming S6 segments and conformational changes in extra- (pore loop) and intracellular linkers connected to pore-forming segments may play a principal role in the modulation of Ca2+ channel inactivation. Structural concepts of Ca2+ channel inactivation are discussed.

Action Potentials↗

PubMed2000

The effect of audit and feedback on immunization delivery: a systematic review.

OBJECTIVE: To assess the effective of audit and feedback (A&F) on immunization delivery by health care professionals. DESIGN: Systematic review of published literature. MAIN OUTCOME MEASURES: Changes in immunization rates. METHODS: We searched Medline between 1966 and 1997. We obtained additional studies from back-searching reference lists and the files of study collaborators. We included studies that were written in English, that included audit and feedback in at least one arm of the study, that studied universally recommended childhood or adult vaccines, and that provided immunization coverage data. Two reviewers read studies independently and abstracted using a validated checklist. Study quality was assessed using criteria standardized by the Cochrane Collaboration. Differences between reviewers were resolved by consensus. RESULTS: The search process resulted in 60 citations; 44 were fully reviewed and 15 met eligibility criteria. Five were randomized trials. Twelve of the fifteen studies found that A&F, alone or in combination with other interventions, were associated with improvements in immunization rates. The magnitude of the effect varied from -17% to +49% change. Study design heterogeneity precluded statistical pooling of study results. CONCLUSIONS: The evidence available from published studies suggests that A&F alone may be an effective strategy for improving immunization rates. The number of well-conducted studies is small, and the effect is variable. Additional well-designed studies are needed to identify the independent effects of A&F, optimal format and frequency of A&F, and to examine its long-term effect on provider immunization practices and costs.

Adult↗

PubMed1999

A randomized study of tracking with outreach and provider prompting to improve immunization coverage and primary care.

OBJECTIVE: To compare and measure the effects and cost-effectiveness of two interventions designed to raise immunization rates. SETTINGS: Nine primary care sites serving impoverished and middle-class children. SUBJECTS: Complete birth cohorts (ages 0 to 12 months; n = 3015) from these sites. INTERVENTIONS: Two 18-month duration interventions: 1) tracking with outreach [tracking/outreach] to bring underimmunized children to their primary care provider office, and 2) a primary care provider office policy change to identify and reduce missed immunization opportunities (prompting). DESIGN: Randomized, controlled trial, randomizing within sites using a two-by-two factorial design. Subjects were allocated to one of four study groups: control, prompting only, tracking/outreach only, and combined prompting with tracking/outreach. Outcomes were obtained by blinded chart abstraction. MEASURES: Immunization status for age; number of days of delay in immunization; primary care utilization; and rates of screening for occult disease. RESULTS: Out of 3015 subjects, 274 subjects (9%) transferred out of the participating sites or had incomplete charts and were excluded. The 2741 (91%) remaining subjects were assessed. At baseline, study groups did not differ in age, gender, insurance type, or immunization status. Of the remaining subjects, 63% received Medicaid. Final series-complete immunization coverage levels were: control, 74%; prompting-only, 76%; tracking/outreach-only 95%; and combined tracking/outreach with prompting, 95%. Analysis of variance showed that: 1) tracking/outreach increased immunization rates 20 percentage points; 2) tracking/outreach decreased mean immunization delay 63 days; 3) tracking/outreach increased mean health supervision visits 0.44 visits per child; 4) tracking/outreach increased mean anemia screening 0.17 screenings per child and mean lead screenings 0.12 screenings per child; 5) impact of tracking/outreach was greatest for uninsured and impoverished patients; and 6) the prompting intervention had no impact on the studied outcomes, and its failure was caused by inconsistent use of prompts and failure to vaccinate ill children when prompted. Using tracking/outreach, the cost per additional child fully immunized was $474. Each $1000 spent on the tracking/outreach intervention resulted in: 2.1 additional fully vaccinated children and 668 fewer child-days of delayed immunization; 4.6 additional health supervision visits and 5.9 additional other visits to the primary care provider; and 1.8 additional anemia screenings and 1.3 additional lead screenings. CONCLUSIONS: Outreach directed toward children not up-to-date on immunizations improves not only immunization status, but also health supervision visit attendance and screening rates. The cost per additional child immunized was high, but should be interpreted in view of the spillover benefits that accompanied improved immunization. Effective means to improve coverage by reducing missed immunization opportunities still need to be identified.

Analysis of Variance↗

PubMed1997

Beta subunit heterogeneity in neuronal L-type Ca2+ channels.

Heterologous expression studies have shown that the activity of voltage-gated Ca2+ channels is regulated by their beta subunits in a beta subunit isoform-specific manner. In this study we therefore investigated if one or several beta subunit isoforms associate with L-type Ca2+ channels in different regions of mammalian brain. All four beta subunit isoforms (beta1b, beta2, beta3, and beta4) are expressed in cerebral cortex as shown in immunoblots. Immunoprecipitation of (+)-[3H]isradipine-labeled L-type channels revealed that the majority of beta subunit-associated L-type channels was associated with beta3 (42 +/- 8%) and beta4 (42 +/- 7%) subunits, whereas beta1b and beta2 were present in a smaller fraction of channel complexes. beta3 and beta4 were also the major L-type channel beta subunits in hippocampus. In cerebellum beta1b, beta2, and beta3 but not beta4 subunits were expressed at lower levels than in cortex. Accordingly, beta4 was the most prominent beta subunit in cerebellar L-type channels. This beta subunit composition was very similar to the one determined for 125I-omega-conotoxin-GVIA-labeled N-type and 125I-omega-conotoxin-MVIIC-labeled P/Q-type channel complexes in cerebral cortex and cerebellum. Our data show that all four beta subunit isoforms associate with L-type Ca2+ channels in mammalian brain. This beta subunit heterogeneity may play an important role for the fine tuning of L-type channel function and modulation in neurons.

Animals↗

PubMed1997

DNA single strand breakage, DNA adducts, and sister chromatid exchange in lymphocytes and phenanthrene and pyrene metabolites in urine of coke oven workers.

OBJECTIVES: To investigate the specificity of biological monitoring variables (excretion of phenanthrene and pyrene metabolites in urine) and the usefulness of some biomarkers of effect (alkaline filter elution, 32P postlabelling assay, measurement of sister chromatid exchange) in workers exposed to polycyclic aromatic hydrocarbons (PAHs). METHODS: 29 coke oven workers and a standardised control group were investigated for frequencies of DNA single strand breakage, DNA protein cross links (alkaline filter elution assay), sister chromatid exchange, and DNA adducts (32P postlabelling assay) in lymphocytes. Phenanthrene and pyrene metabolites were measured in 24 hour urine samples. 19 different PAHs (including benzo(a)pyrene, pyrene, and phenanthrene) were measured at the workplace by personal air monitoring. The GSTT1 activity in erythrocytes and lymphocyte subpopulations in blood was also measured. RESULTS: Concentrations of phenanthrene, pyrene, and benzo(a)pyrene in air correlated well with the concentration of total PAHs in air; they could be used for comparisons of different workplaces if the emission compositions were known. The measurement of phenanthrene metabolites in urine proved to be a better biological monitoring variable than the measurement of 1-hydroxypyrene. Significantly more DNA strand breaks in lymphocytes of coke oven workers were found (alkaline filter elution assay); the DNA adduct rate was not significantly increased in workers, but correlated with exposure to PAHs in a semiquantitative manner. The number of sister chromatid exchanges was lower in coke oven workers but this was not significant; thus counting sister chromatid exchanges was not a good variable for biomonitoring of coke oven workers. Also, indications for immunotoxic influences (changes in lymphocyte subpopulations) were found. CONCLUSIONS: The measurement of phenanthrene metabolites in urine seems to be a better biological monitoring variable for exposure to PAHs than measurement of hydroxypyrene. The alkaline filter elution assay proved to be the most sensitive biomarker for genotoxic damage, whereas the postlabelling assay was the only one with some specificity for DNA alterations caused by known compounds.

Adult↗

PubMed1996

Identification of benz(othi)azepine-binding regions within L-type calcium channel alpha1 subunits.

To identify the binding domain for diltiazem-like Ca2+ antagonists on L-type Ca2+ channel alpha1 subunits we synthesized the benzazepine [3H]benziazem as a novel photoaffinity probe. [3H]Benziazem reversibly labeled the benzothiazepine (BTZ)-binding domain of partially purified skeletal muscle Ca2+ channels with high affinity (Kd = 12 nM) and photoincorporated into its binding domain with high yield (>66%). Antibody mapping of proteolytic labeled fragments revealed specific labeling of regions associated with transmembrane segments S6 in repeats III and IV. More than 50% of the labeling was found in the tryptic fragment alanine 1023-lysine 1077 containing IIIS6 together with extracellular and intracellular amino acid residues. The remaining labeling was identified in a second site comprising segment S6 in repeat IV and adjacent residues. Unlike for dihydropyridines, no labeling was observed in the connecting IIIS5-IIIS6 linker. The [3H]benziazem photolabeled regions must be in close contact to the drug molecule when bound to the channel. We propose that the determinants for high affinity BTZ binding are located within or in close proximity to segments IIIS6 and/or IVS6. Therefore the binding domain for BTZs, like for the other main classes of Ca2+ antagonists, must be located in close proximity to pore-forming regions of the channel.

Affinity Labels↗