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Dive into the research topics where Johannes Hierholzer is active.

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Featured researches published by Johannes Hierholzer.


The American Journal of Clinical Nutrition | 2011

Effects of supplemented isoenergetic diets differing in cereal fiber and protein content on insulin sensitivity in overweight humans

Martin O. Weickert; Michael Roden; Frank Isken; D Hoffmann; Peter Nowotny; M Osterhoff; Michael Blaut; Carl Alpert; Özlem Gögebakan; Christiane Bumke-Vogt; Friederike Mueller; Jürgen Machann; Thomas M. Barber; Klaus J. Petzke; Johannes Hierholzer; S Hornemann; Michael Kruse; Anne-Kathrin Illner; Angela Kohl; Christian von Loeffelholz; Ayman M. Arafat; Matthias Möhlig; Andreas F.H. Pfeiffer

BACKGROUND Despite their beneficial effects on weight loss and blood lipids, high-protein (HP) diets have been shown to increase insulin resistance and diabetes risk, whereas high-cereal-fiber (HCF) diets have shown the opposite effects on these outcomes. OBJECTIVE We compared the effects of isoenergetic HP and HCF diets and a diet with moderate increases in both cereal fibers and dietary protein (Mix diet) on insulin sensitivity, as measured by using euglycemic-hyperinsulinemic clamps with infusion of [6,6-(2)H(2)]glucose. DESIGN We randomly assigned 111 overweight adults with features of the metabolic syndrome to 1 of 4 two-phased, 18-wk isoenergetic diets by group-matching. Per 3-d food protocols, the percentages of energy derived from protein and carbohydrates and the intake of cereal fiber per day, respectively, were as follows-after 6 wk: 17%, 52%, and 14 g (control); 17%, 52%, and 43 g (HCF); 28%, 43%, and 13 g (HP); 23%, 44%, and 26 g (Mix); after 18 wk: 17%, 51%, and 15 g (control); 17%, 51%, and 41 g (HCF); 26%, 45%, and 14 g (HP); and 22%, 46%, and 26 g (Mix). Eighty-four participants completed the study successfully and were included in the final analyses. Adherence was supported by the provision of tailored dietary supplements twice daily in all groups. RESULTS Insulin sensitivity expressed as an M value was 25% higher after 6 wk of the HCF diet than after 6 wk of the HP diet (subgroup analysis: 4.61 ± 0.38 compared with 3.71 ± 0.36 mg · kg(-1) · min(-1), P = 0.008; treatment × time interaction: P = 0.005). Effects were attenuated after 18 wk (treatment × time interaction: P = 0.054), which was likely explained by lower adherence to the HP diet. HP intake was associated with a tendency to increased protein expression in adipose tissue of the translation initiation factor serine-kinase-6-1, which is known to mediate amino acid-induced insulin resistance. Biomarkers of protein intake indicated interference of cereal fibers with dietary protein absorption. CONCLUSION Greater changes in insulin sensitivity after intake of an isoenergetic HCF than after intake of an HP diet might help to explain the diverse effects of these diets on diabetes risk. This trial is registered at clinicaltrials.gov as NCT00579657.


Abdominal Imaging | 1995

Drug smuggling by ingested cocaine-filled packages: conventional x-ray and ultrasound.

Johannes Hierholzer; M. Cordes; H. Tantow; U. Keske; Jürgen Mäurer; Roland Felix

PurposeTo evaluate the imaging characteristics and the diagnostic value of both abdominal ultrasound and conventional abdominal x-ray in identifying ingested drug packages in “body packers.”Materials and MethodsTwelve individuals were studied prospectively by abdominal ultrasound and by abdominal x-ray to rule out incorporated drug containers.ResultsBoth abdominal ultrasound and abdominal x-ray correctly identified the 7 of 12 individuals who had ingested multiple drug packages. In 5 of the 12 individuals, ultrasound as well as abdominal x-ray were correctly unremarkable with regard to abdominal foreign bodies.ConclusionsAbdominal ultrasound and abdominal x-ray both represent valuable diagnostic tools in the assessment of ingested drug packages. Abdominal x-ray is superior to ultrasound in differentiating ingested drug-filled condoms from “pseudocondoms.”


Journal of Vascular and Interventional Radiology | 2003

Percutaneous Osteoplasty as a Treatment for Painful Malignant Bone Lesions of the Pelvis and Femur

Johannes Hierholzer; Gianni Anselmetti; Heiko Fuchs; Claude Depriester; Karin Koch; Dirk Pappert

The purposes of this report are to describe percutaneous osteoplasty as a highly effective minimally invasive procedure to treat painful malignant bone lesions of the pelvis, ilium, and femur and to discuss the relevant literature. Five patients with histologically proven metastases to the pelvis, ilium, or femur were treated by percutaneous injection of liquid bone cement as an attempt to control severe bone pain. After percutaneous osteoplasty, all five patients experienced immediate and substantial pain relief and did not require pain medication for the duration of follow-up. No clinically significant complications occurred. Whereas percutaneous osteoplasty of the spine (vertebroplasty) is well-described and widely accepted to treat pain caused by benign or malignant vertebral body diseases, osteoplasty of bones outside the spine is less known. The immediate good clinical results observed in our small patient group should encourage more widespread application of this palliative treatment.


CardioVascular and Interventional Radiology | 2007

Complications in Percutaneous Vertebroplasty Associated with Puncture or Cement Leakage

Clemens Baumann; Heiko Fuchs; Jürgen Kiwit; Kerstin Westphalen; Johannes Hierholzer

Due to the minimally invasive character and excellent clinical outcome of percutaneous vertebroplasty (PVP), the procedure is being performed in greatly increasing numbers. While PVP has a low complication rate in general, severe complications can occur. We focus on the imaging appearance of complications of PVP associated with puncture or cement leakage—from harmless to life-threatening.


PLOS ONE | 2014

Validation of Anthropometric Indices of Adiposity against Whole-Body Magnetic Resonance Imaging – A Study within the German European Prospective Investigation into Cancer and Nutrition (EPIC) Cohorts

Jasmine Neamat-Allah; Diana Wald; Anika Hüsing; Birgit Teucher; Andrea Wendt; Stefan Delorme; Julien Dinkel; Matthaeus Vigl; Manuela M. Bergmann; Silke Feller; Johannes Hierholzer; Heiner Boeing; Rudolf Kaaks

Background In epidemiological studies, measures of body fat generally are obtained through anthropometric indices such as the body mass index (BMI), waist (WC), and hip circumferences (HC). Such indices, however, can only provide estimates of a person’s true body fat content, overall or by adipose compartment, and may have limited accuracy, especially for the visceral adipose compartment (VAT). Objective To determine the extent to which different body adipose tissue compartments are adequately predicted by anthropometry, and to identify anthropometric measures alone, or in combination to predict overall adiposity and specific adipose tissue compartments, independently of age and body size (height). Methods In a sub-study of 1,192 participants of the German EPIC (European Prospective Investigation into Cancer and Nutrition) cohorts, whole-body MRI was performed to determine adipose and muscle tissue compartments. Additional anthropometric measurements of BMI, WC and HC were taken. Results After adjusting for age and height, BMI, WC and HC were better predictors of total body volume (TBV), total adipose tissue (TAT) and subcutaneous adipose tissue (SAT) than for VAT, coronary adipose tissue (CAT) and skeletal muscle tissue (SMT). In both sexes, BMI was the best predictor for TBV (men: r = 0.72 [0.68–0.76], women: r = 0.80 [0.77–0.83]) and SMT (men: r = 0.52 [0.45–0.57], women: r = 0.48 [0.41–0.54]). WC was the best predictor variable for TAT (r = 0.48 [0.41–0.54]), VAT (r = 0.44 [0.37–0.50]) and CAT (r = 0.34 [0.26–0.41]) (men), and for VAT (r = 0.42 [0.35–0.49]) and CAT (r = 0.29 [0.22–0.37]) (women). BMI was the best predictor for TAT (r = 0.49 [0.43–0.55]) (women). HC was the best predictor for SAT (men (r = 0.39 [0.32–0.45]) and women (r = 0.52 [0.46–0.58])). Conclusions Especially the volumes of internal body fat compartments are poorly predicted by anthropometry. A possible implication may be that associations of chronic disease risks with the sizes of internal body fat as measured by BMI, WC and HC may be strongly underestimated.


Journal of Affective Disorders | 2001

Bone mineral density in pre-and post-menopausal women with affective disorder treated with long-term L-thyroxine augmentation

Laszlo Gyulai; Michael Bauer; Felipe Garcia-Espana; Johannes Hierholzer; Andreas Baumgartner; Anne Berghöfer; Peter C. Whybrow

BACKGROUND Augmentation with TSH-suppressive L-thyroxine (T4) has been shown to improve the course of illness in otherwise refractory affective disorders. This collaborative study investigates whether T4 augmentation for a minimum of 12 months decreases bone mineral density (BMD) in 26 pre- and post-menopausal women with affective disorder. METHODS We measured BMD at the femoral neck, Wards triangle, trochanter and lumbar vertebrae (L1-L4) in 13 premenopausal and 13 postmenopausal women with affective disorder using dual energy X-ray absorptiometry. BMD was expressed as g/cm(2) and as a Z-score, calculated using bone density data from the international reference population standard. RESULTS The Z-scores for the pre- and post-menopausal women were within the reference range of the age and sex matched population standard. BMD for the composite group also did not differ either from the population standard. BMD in the lumbar spine and hip did not differ significantly between the pre- and post-menopausal groups. However, there were a relatively high number of postmenopausal patients with BMDs one S.D. lower than the population standard. LIMITATIONS This is a cross-sectional study with a relatively small sample size. CONCLUSIONS The study demonstrates that T4 augmentation treatment does not reduce BMD to a clinically significant degree in many women with affective disorder. However, the resilience of bone structure to T4 treatment may vary with site and menopausal status. This study underscores the need for regular assessment of BMD during adjunctive thyroid treatments for affective disorder, especially in postmenopausal women.


Spine | 2013

Cement directed kyphoplasty reduces cement leakage as compared with vertebroplasty: results of a controlled, randomized trial.

Thomas J. Vogl; Robert Pflugmacher; Johannes Hierholzer; Gerd Stender; Matthew J. Gounis; Ajay K. Wakhloo; Christian Fiebig; Renate Hammerstingl

Study Design. A novel randomized, controlled, unblinded clinical trial comparing 2 procedural interventions for painful osteoporotic vertebral compression fractures. Objective. The primary study objective was to evaluate cement leakage for a cement directed kyphoplasty system (CDKS) with anteriorly biased cement flow and vertebroplasty. The secondary study objective was to compare adjacent level fracture rates and vertebral body height for these 2 intervention methods. Summary of Background Data. Cement leakage remains a significant clinical problem associated with vertebroplasty and kyphoplasty procedures. Uncontrolled cement flow in the posterior direction can result in leakage into the vertebral veins or spinal canal, leading to potentially serious clinical complications. Methods. Seventy-seven patients with painful osteoporotic vertebral compression fractures were enrolled. Patients were randomized 2:1 for treatment with CDKS (49 patients, 65 levels) or vertebroplasty (28 patients, 39 levels). Cement leakage was evaluated from radiographs and computed tomographic scans. Three- and 12-month follow-ups included additional radiographs and computed tomographic scans to assess changes in vertebral body height and the incidence of new fractures. Results. Treatment with CDKS significantly reduced the number of levels with leaks and the total number of leaks per level, as compared with vertebroplasty (P = 0.0132 and P = 0.0012, respectively). Significantly, fewer lateral cortical and spinal canal leaks (posterior leaks) occurred in the CDKS group (P = 0.0050, P = 0.02260, respectively). Three adjacent level fractures occurred in the vertebroplasty group, as compared with 2 in the CDKS group. Vertebral body height maintenance was equivalent. Conclusion. Cement directed kyphoplasty effectively reduces posterior cement leakage, reducing the risk of leakage related complications. Level of Evidence: 2


Transplant International | 1999

Contribution of color and power Doppler sonography to the differential diagnosis of acute and chronic rejection, and tacrolimus nephrotoxicity in renal allografts

Stephan Venz; Andreas Kahl; Johannes Hierholzer; Matthias Gutberlet; Bettina Windrich; Wolf O. Bechstein; Norbert Hosten; Ulrich Frei; Roland Felix

The aim of the present study was to differentiate acute rejection, chronic rejection, and tacrolimus nephrotoxicity with color and power Doppler imaging of renal transplants. One hundred examinations were obtained from 45 patients. Pulsatility and resistive indices were calculated from color Doppler images. The grade of renal vascularization was quantified using computer‐assisted pixel analysis in a rectangular region‐of‐interest. The percentage of vessel‐covered renal parenchyma (POV) was calculated using a histogram that discriminated renal vessels from renal parenchyma via power Doppler images. Furthermore, the distance from the most peripherally located vessels to the renal capsule (PVD) was measured. A reduced POV ± 55 % proved to be the best discriminator when chronic rejection was suspected (sensitivity 79 %, specificity 87 %). Tacrolimus nephrotoxicity showed not only a moderate elevation of the Doppler signal but also an increased PVD±3.9 mm and a normal POV. We conclude that the evaluation of renal vessels by power Doppler images improves diagnostic accuracy for patients with renal allografts.


The Journal of Clinical Endocrinology and Metabolism | 2014

Modulation of Amino Acid Metabolic Signatures by Supplemented Isoenergetic Diets Differing in Protein and Cereal Fiber Content

John G. Hattersley; Andreas F.H. Pfeiffer; Michael Roden; Klaus-Jürgen Petzke; D Hoffmann; Natalia Rudovich; Harpal S. Randeva; Manu Vatish; M Osterhoff; Özlem Goegebakan; S Hornemann; Peter Nowotny; Jürgen Machann; Johannes Hierholzer; Christian von Loeffelholz; Matthias Möhlig; Ayman M. Arafat; Martin O. Weickert

CONTEXT Amino-acid (AA) metabolic signatures differ in insulin-resistant (IR) obese vs normal-weight subjects, improve after weight loss, and seem to predict the risk of type 2 diabetes. It is unknown whether weight-maintaining dietary measures aimed at influencing IR alter AA signatures of high-risk subjects. SETTING AND DESIGN In the randomized controlled Protein, Fiber and Metabolic Syndrome (ProFiMet) trial we investigated effects of four isoenergetic, moderately fat-reduced diets varying in protein and cereal-fiber contents on complete AA metabolic signatures in 76 group-matched overweight or obese high-risk subjects. We analyzed the relation of whole-body and hepatic IR with AA signatures, body fat composition and liver fat, after 0, 6, and 18 weeks of dietary intervention. Discrimination between diets was further enhanced by providing tailored dietary supplements for twice-daily consumption over 18 weeks in all groups. RESULTS Baseline AA, including branched-chain signatures significantly related to IR, liver fat, and visceral fat mass. Isoenergetic variation of protein and cereal-fiber dietary contents, but not fat restriction, significantly influenced IR, whereas the relation of AA with IR changed with all diets. The tryptophan ratio was significantly suppressed in obese vs overweight participants, but increased after 6 weeks of high cereal-fiber intake to a nonobese phenotype. Modeling analyses revealed diet-induced alterations of complex AA profiles to relate to 70% and 62% of changes in whole-body and hepatic IR. CONCLUSIONS We demonstrate that relatively short-term isoenergetic changes in the diet significantly alter the relation of AA signatures with IR, with possible implications on the determination and treatment of diabetes risk.


PLOS ONE | 2012

Quantifying the Improvement of Surrogate Indices of Hepatic Insulin Resistance Using Complex Measurement Techniques

John G. Hattersley; Matthias Möhlig; Michael Roden; Ayman M. Arafat; Christian von Loeffelholz; Peter Nowotny; Jürgen Machann; Johannes Hierholzer; M Osterhoff; Michael Khan; Andreas F.H. Pfeiffer; Martin O. Weickert

We evaluated the ability of simple and complex surrogate-indices to identify individuals from an overweight/obese cohort with hepatic insulin-resistance (HEP-IR). Five indices, one previously defined and four newly generated through step-wise linear regression, were created against a single-cohort sample of 77 extensively characterised participants with the metabolic syndrome (age 55.6±1.0 years, BMI 31.5±0.4 kg/m2; 30 males). HEP-IR was defined by measuring endogenous-glucose-production (EGP) with [6–62H2] glucose during fasting and euglycemic-hyperinsulinemic clamps and expressed as EGP*fasting plasma insulin. Complex measures were incorporated into the model, including various non-standard biomarkers and the measurement of body-fat distribution and liver-fat, to further improve the predictive capability of the index. Validation was performed against a data set of the same subjects after an isoenergetic dietary intervention (4 arms, diets varying in protein and fiber content versus control). All five indices produced comparable prediction of HEP-IR, explaining 39–56% of the variance, depending on regression variable combination. The validation of the regression equations showed little variation between the different proposed indices (r 2 = 27–32%) on a matched dataset. New complex indices encompassing advanced measurement techniques offered an improved correlation (r = 0.75, P<0.001). However, when validated against the alternative dataset all indices performed comparably with the standard homeostasis model assessment for insulin resistance (HOMA-IR) (r = 0.54, P<0.001). Thus, simple estimates of HEP-IR performed comparable to more complex indices and could be an efficient and cost effective approach in large epidemiological investigations.

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Michael Cordes

Free University of Berlin

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Michael Roden

University of Düsseldorf

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