Hemorrhage in vitamin K deficiency--a preventable entity

Der diaplazentare Transport von Vitamin K ist kaum messbar, die Muttermilch ist arm an Vitamin K und die intestinale Flora von Neugeborenen produziert praktisch kein Vitamin K. Deshalb weisen gesunde Neugeborene «physiologischerweise» tiefe Vitamin-K-Spiegel auf, was durch Verminderung der Vitamin-K-abhängigen Gerinnungsfaktoren zu schweren Mangelblutungen führen kann. Die klassische Form der Vitamin-K-Mangelblutung tritt mit einer Inzidenz von bis zu 1.5% bis zum 7. Lebenstag auf, die Spätform wird bis zur 12. Lebenswoche bei bis zu 10 von 100000 Neugeborenen festgestellt. Mit einer adäquaten Vitamin-K-Prophylaxe lassen sich Vitamin-K-Mangelblutungen grösstenteils verhindern. Die heute in der Schweiz empfohlene Prophylaxe von 3 oralen Dosen à 2 mg Konakion® MM in der 4. Lebensstunde, am 4. Lebenstag und in der 4. Lebenswoche ist bezüglich unerwünschter Nebenwirkung äusserst sicher, insbesondere besteht kein erhöhtes Krebsrisiko. Angesichts der dramatischen Folgen der häufig intrakraniell lokalisierten Vitamin-K-Mangelblutungen ist sowohl bei medizinischen Fachpersonen als auch bei den Eltern eine möglichst gute Compliance für diese einfache und sichere Prophylaxe wie auch eine entsprechende Aufklärung anzustreben.

Effects of expectation and caffeine on arousal, well-being, and reaction time

The objective of this study is to determine the impact of expectation associated with placebo and caffeine ingestion. We used a three-armed, randomized, double-blind design. Two three-armed experiments varying instruction (true, false, control) investigated the role of expectations of changes in arousal (blood pressure, heart rate), subjective well-being, and reaction time (RT). In Experiment 1 (N = 45), decaffeinated coffee was administered, and expectations were produced in one group by making them believe they had ingested caffeinated coffee. In Experiment 2 (N = 45), caffeinated orange juice was given in both experimental groups, but only one was informed about the true content. In Experiment 1, a significant effect for subjective alertness was found in the placebo treatment compared to the control group. However, for RT and well-being no significant effects were found. In Experiment 2, no significant expectancy effects were found. Caffeine produced large effects for blood pressure in both treatments compared to the control group, but the effects were larger for the false information group. For subjective well-being (alertness, calmness), considerable but nonsignificant changes were found for correctly informed participants, indicating possible additivity of pharmacologic effect and expectations. The results tentatively indicate that placebo and expectancy effects primarily show through introspection.

Coronary collateral flow in response to endurance exercise training

BACKGROUND: In humans, it is not known whether physical endurance exercise training promotes coronary collateral growth. The following hypotheses were tested: the expected collateral flow reduction after percutaneous coronary intervention of a stenotic lesion is prevented by endurance exercise training; collateral flow supplied to an angiographically normal coronary artery improves in response to exercise training; there is a direct relationship between the change of fitness after training and the coronary collateral flow change. METHODS AND RESULTS: Forty patients (age 61+/-8 years) underwent a 3-month endurance exercise training program with baseline and follow-up assessments of coronary collateral flow. Patients were divided into an exercise training group (n=24) and a sedentary group (n=16) according to the fact whether they adhered or not to the prescribed exercise program, and whether or not they showed increased endurance (VO2max in ml/min per kg) and performance (W/kg) during follow-up versus baseline bicycle spiroergometry. Collateral flow index (no unit) was obtained using pressure sensor guidewires positioned in the coronary artery undergoing percutaneous coronary intervention and in a normal vessel. In the vessel initially undergoing percutaneous coronary intervention, there was an increase in collateral flow index among exercising but not sedentary patients from 0.155+/-0.081 to 0.204+/-0.056 (P=0.03) and from 0.189+/-0.084 to 0.212+/-0.077 (NS), respectively. In the normal vessel, collateral flow index changes were from 0.176+/-0.075 to 0.227+/-0.070 in the exercise group (P=0.0002), and from 0.219+/-0.103 to 0.238+/-0.086 in the sedentary group (NS). A direct correlation existed between the change in collateral flow index from baseline to follow-up and the respective alteration of VO2max (P=0.007) and Watt (P=0.03). CONCLUSION: A 3-month endurance exercise training program augments coronary collateral supply to normal vessels, and even to previously stenotic arteries having undergone percutaneous coronary intervention before initiating the program. There appears to be a dose-response relation between coronary collateral flow augmentation and exercise capacity gained.

Beneficial effect of recruitable collaterals: a 10-year follow-up study in patients with stable coronary artery disease undergoing quantitative collateral measurements

BACKGROUND: The prognostic relevance of the collateral circulation is still controversial. The goal of this study was to assess the impact on survival of quantitatively obtained, recruitable coronary collateral flow in patients with stable coronary artery disease during 10 years of follow-up. METHODS AND RESULTS: Eight-hundred forty-five individuals (age, 62+/-11 years), 106 patients without coronary artery disease and 739 patients with chronic stable coronary artery disease, underwent a total of 1053 quantitative, coronary pressure-derived collateral measurements between March 1996 and April 2006. All patients were prospectively included in a collateral flow index (CFI) database containing information on recruitable collateral flow parameters obtained during a 1-minute coronary balloon occlusion. CFI was calculated as follows: CFI = (P(occl) - CVP)/(P(ao) - CVP) where P(occl) is mean coronary occlusive pressure, P(ao) is mean aortic pressure, and CVP is central venous pressure. Patients were divided into groups with poorly developed (CFI < 0.25) or well-grown collateral vessels (CFI > or = 0.25). Follow-up information on the occurrence of all-cause mortality and major adverse cardiac events after study inclusion was collected. Cumulative 10-year survival rates in relation to all-cause deaths and cardiac deaths were 71% and 88%, respectively, in patients with low CFI and 89% and 97% in the group with high CFI (P=0.0395, P=0.0109). Through the use of Cox proportional hazards analysis, the following variables independently predicted elevated cardiac mortality: age, low CFI (as a continuous variable), and current smoking. CONCLUSIONS: A well-functioning coronary collateral circulation saves lives in patients with chronic stable coronary artery disease. Depending on the exact amount of collateral flow recruitable during a brief coronary occlusion, long-term cardiac mortality is reduced to one fourth compared with the situation without collateral supply.

Pineal calcification in Alzheimer's disease: an in vivo study using computed tomography

Melatonin has been postulated to have diverse properties, acting as an antioxidant, a neuroprotector, or a stabilizer within the circadian timing system, and is thus thought to be involved in the aging process and Alzheimer's disease (AD). We used computed tomography to determine the degree of pineal calcification (DOC), an intra-individual melatonin deficit marker, as well as the size of uncalcified pineal tissue, in 279 consecutive memory clinic outpatients (AD: 155; other dementia: 25; mild cognitive impairment: 33; depression: 66) and 37 age-matched controls. The size of uncalcified pineal tissue in patients with AD (mean 0.15 cm(2) [S.D. 0.24]) was significantly smaller than in patients with other types of dementia (0.26 [0.34]; P=0.038), with depression (0.28 [0.34]; P=0.005), or in controls (0.25 [0.31]; P=0.027). Additionally, the DOC in patients with AD (mean 76.2% [S.D. 26.6]) was significantly higher than in patients with other types of dementia (63.7 [34.7]; P=0.042), with depression (60.5 [33.8]; P=0.001), or in controls (64.5 [30.6]; P=0.021). These two findings may reflect two different aspects of melatonin in AD. On the one hand, the absolute amount of melatonin excretion capability, as indicated by uncalcified pineal volume, refers to the antioxidant properties of melatonin. On the other hand, the relative reduction in melatonin production capability in the individual, as indicated by DOC, refers to the circadian properties of melatonin.

Cervical soft tissue imaging using a mobile CBCT scanner with a flat panel detector in comparison with corresponding CT and MRI data sets

OBJECTIVE: The aim of this study was to evaluate soft tissue image quality of a mobile cone-beam computed tomography (CBCT) scanner with an integrated flat-panel detector. STUDY DESIGN: Eight fresh human cadavers were used in this study. For evaluation of soft tissue visualization, CBCT data sets and corresponding computed tomography (CT) and magnetic resonance imaging (MRI) data sets were acquired. Evaluation was performed with the help of 10 defined cervical anatomical structures. RESULTS: The statistical analysis of the scoring results of 3 examiners revealed the CBCT images to be of inferior quality regarding the visualization of most of the predefined structures. Visualization without a significant difference was found regarding the demarcation of the vertebral bodies and the pyramidal cartilages, the arteriosclerosis of the carotids (compared with CT), and the laryngeal skeleton (compared with MRI). Regarding arteriosclerosis of the carotids compared with MRI, CBCT proved to be superior. CONCLUSIONS: The integration of a flat-panel detector improves soft tissue visualization using a mobile CBCT scanner.

3D C-arm as an alternative modality to CT in postmortem imaging: technical feasibility

OBJECT: The aim of our study was to demonstrate the image quality of the new device using human cadavers, extending the horizon of available imaging modalities in forensic medicine. MATERIALS AND METHODS: Six human cadavers were examined, revealing C-arm data sets of the head, neck thorax, abdomen and pelvis. High-resolution mode was performed with 500 fluoroscopy shots during a 190 degrees orbital movement with a constant tube voltage of 100 kV and a current of 4.6 mA. Based on these data sets subsequent three-dimensional reconstructions were generated. RESULTS: Reconstructed data sets revealed high-resolution images of all skeletal structures in a near-CT quality. The same image quality was available in all reconstruction planes. Artefacts caused by restorative dental materials are less accentuated in CBCT data sets. The system configuration was not powerful enough to generate sufficient images of intracranial structures. CONCLUSION: After the here-demonstrated encouraging preliminary results, the forensic indications that would be suitable for imaging with a 3D C-arm have to be defined. Promising seems the visualization local limited region of interest as the cervical spine or the facial skeleton.

Sensitivity of osteoblasts, fibroblasts, bone marrow cells, and dendritic cells to 5-aminolevulinic acid based photodynamic therapy

INTRODUCTION: Photodynamic therapy with 5-aminolevulinic acid (5-ALA-PDT) exerts cell type specific effects on target cells. Since chondrocytes were found to be more resistant than osteoblasts to 5-ALA-PDT, the pre-treatment of osteochondral grafts with 5-ALA-PDT may represent a means to devitalize the osseous portion while maintaining functional cartilage. The present study was designed to determine the effects of 5-ALA-PDT in vitro on cell populations residing in skeletal tissues. METHODS: Osteoblasts, fibroblasts, bone marrow cells, and dendritic cells were incubated with 0.5 mM 5-ALA for 4 h. Protoporphyrin IX (PpIX) accumulation and after exposure to light cellular functions were assessed for up to 6 days. RESULTS: Accumulation of PpIX reached a plateau at 0.5 mM in osteoblasts, fibroblasts, and dendritic cells, and at 2.0 mM in bone marrow cells. At 0.5 mM 5-ALA, similar responses to illumination were observed in all cells with a survival rate of less than 12% at a light dose of 20 J/cm(2). The function of osteoblasts (proliferation, levels of mRNA encoding collagen type I, alkaline phosphatase activity) and fibroblasts (proliferation, levels of mRNAs encoding collagens type I and III) was not affected, when the cells were treated with 5-ALA and light doses of < or =10 J/cm(2). Paralleling the reduction of viable cells after 5-ALA-PDT, the capacity of dendritic cells to stimulate T cells in a mixed leukocyte reaction decreased to 4+/-2% at 20 J/cm(2). CONCLUSION: The investigated cell types were sensitive to 5-ALA-PDT and the residual cell debris did not elicit an allogenic response. These findings, together with the resistance of chondrocytes to 5-ALA-PDT, encourage the further investigation of this protocol in the pretreatment of osteochondral allografts.