Der Röntgenthorax: Routineindikation in der Nachsorge des differenzierten Schilddrüsenkarzinoms?

Ziel: Anhand einer retrospektiven Untersuchung wurde überprüft, inwieweit der routinemäßige Einsatz des Röntgenthorax auch bei Low-risk-Patienten trotz der hohen Sensitivität des Tumormarkers Thyreoglobulin sinnvoll ist. Methode: Es wurden die Krankengeschichten von 609 Patienten mit einem differenzierten Schilddrüsenkarzinom ausgewertet. Bei 50 Patienten wurde eine pulmonale Metastasierung diagnostiziert. Der Thyreoglobulinwert zum Zeitpunkt der Diagnosestellung der pulmonalen Metastasierung wurde mit dem Befund des Röntgenthorax und der vorhandenen weiteren Diagnostik, wie der lod-131-Ganzkörperszintigraphie und CT des Thorax, soweit vorhanden, verglichen. Ergebnisse: Die gefundene Sensitivität des Röntgenthorax im Nachweis von Lungenmetastasen lag mit 52% unterhalb der Sensitivität der 131 -lod-Ganzkörperszintigraphie (64%), der Thorax-CT (82%) und der Sensitivität des Thyreoglobulins unter Suppressionsbedingungen (86%). Bei Patienten mit papillärem Schilddrüsenkarzinom der Tumorstadien I und II entwickelte nur ein Patient im Verlauf eine Lungenmetastasierung. Der Nachweis von Lungenfiliae nur mit Hilfe des Röntgenthorax bei einem Thyreoglobulinwert unter der Nachweisgrenze ist in einer solchen Low-risk-Gruppe sehr selten (berechnete Wahrscheinlichkeit: 1:4000) und mit erheblichen Kosten verbunden. Schlußfolgerung: Der routinemäßige, lebenslange Einsatz des Röntgenthorax ohne Rezidivverdacht (z. B. Thyreoglobulin positiv) ist für Low-risk-Patienten zu überdenken.

Onko-PET: Bildanalyse mittels Monitor versus standardisierter Filmdokumentation

Ziel: Die Wertigkeit einer standardisierten Filmdokumentation in der Beurteilung von 2-[18F]Fluor-2-deoxy-D-Glukose (F-18-FDG) Onko-PET-Untersuchungen sollte untersucht werden. Methoden: 100 Onko-PET-Untersuchungen (ohne Schwächungskorrektur) wurden in Hinblick auf Zahl und Lokalisation malignitätsverdächtiger Läsionen ausgewertet: zum einen mittels standardisierter Filmvorlagen und zum anderen unter zusätzlicher Analyse am Monitor. Die Filmdokumentation beinhaltet erstens transversale Schnitte des Gehirns, zweitens koronale Schnitte und Maximum-intensity-projections (MIPs) sowohl des Kopf-/Halsbereiches als auch drittens des Körperstammes und viertens MIPs der Beine. Bei der Monitorauswertung wurden sämtliche Körperabschnitte in koronaler, transversaler und sagittaler Schnittführung analysiert. Ergebnisse: Insgesamt wurden 315 Läsionen bei 100 Patienten detektiert. Bei 96/100 Untersuchungen fand sich eine Übereinstimmung beider Auswertemethoden in Anzahl und Lokalisation der Läsionen. In der Filmauswertung wurden bei drei Patienten insgesamt sieben Herde in den Beinen übersehen. 9/315 Läsionen in 2/100 Patienten erfuhren durch die zusätzliche Monitorauswertung eine Lokalisationsänderung. Hiervon befanden sich acht der neun Läsionen in den Beinen. Erst nach zusätzlicher Dokumentation der Beine in koronaler Schnittführung wurden sämtliche, in den MIPs übersehene Läsionen detektiert und die topographisch falsch zugeordneten Läsionen konnten konkordant zur Monitorauswertung lokalisiert werden. Bei dieser so ergänzten Filmdokumentation führte die zusätzliche Monitorauswertung zu keiner Detektion weiterer Herde und zu einer klinisch nicht relevanten Lokalisationsänderung von lediglich 1/322 Läsionen. Schlußfolgerung: Die beschriebene, standardisierte Filmdokumentation erlaubt eine Befundung unter nur noch gezieltem Einsatz der Analyse am Monitor. Darüber hinaus entspricht der hier vorgestellte Ansatz den Intentionen der nuklearmedizinischen Arbeitsgemeinschaft Standardisierung, daß auswärtige Voruntersuchungen problemlos in eine Verlaufsbeurteilung einbezogen werden können.

Computer simulations suggest that acute correction of hyperglycaemia with an insulin bolus protocol might be useful in brain FDG PET

Aim: FDG PET in hyperglycaemic subjects often suffers from limited statistical image quality, which may hamper visual and quantitative evaluation. In our study the following insulin bolus protocol is proposed for acute correction of hyperglycaemia (> 7.0 mmol/l) in brain FDG PET. (i) Intravenous bolus injection of short-acting insulin, one I.E. for each 0.6 mmol/l blood glucose above 7.0. (ii) If 20 min after insulin administration plasma glucose is ≤ 7.0 mmol/l, proceed to (iii). If insulin has not taken sufficient effect step back to (i). Compute insulin dose with the updated blood glucose level. (iii) Wait further 20 min before injection of FDG. (iv) Continuous supervision of the patient during the whole scanning procedure. Methods: The potential of this protocol for improvement of image quality in brain FDG PET in hyperglycaemic subjects was evaluated by computer simulations within the Sokoloff model. A plausibility check of the prediction of the computer simulations on the magnitude of the effect that might be achieved by correction of hyperglycaemia was performed by retrospective evaluation of the relation between blood glucose level and brain FDG uptake in 89 subjects in whom FDG PET had been performed for diagnosis of Alzheimer's disease. Results: The computer simulations suggested that acute correction of hyperglycaemia according to the proposed bolus insulin protocol might increase the FDG uptake of the brain by up to 80%. The magnitude of this effect was confirmed by the patient data. Conclusion: The proposed management protocol for acute correction of hyper glycaemia with insulin has the potential to significantly improve the statistical quality of brain FDG PET images. This should be confirmed in a prospective study in patients.

Prevalence of iodine- and thyroglobulin negative findings in differentiated thyroid cancer

Aim: The prevalence of iodine- and thyroglobulin-nega-tive findings was evaluated in all patients with differentiated thyroid cancer (DTC) treated from 1961 until 1998 at the Department of Nuclear Medicine, University Hospital Hamburg-Eppendorf. Methods: A total of 490 patients with papillary thyroid cancer (PCA) and 242 patients with follicular thyroid cancer (FCA) were analyzed retrospectively. Patients were divided into four groups: 1: no recurrence, 2: recurrent disease, 3: primary metas-tatic/progressive disease and 4: inconclusive follow-up. Results of iodine scan, serum-TG, and additional imaging modalities as well as histology were compared in all patients. Results: 21/490 (4,3%) of patients with PCA and 16/242 (6,6%) with FCA suffered from recurrent disease. 62/490 (12,7%) of patients with PCA and 59/242 (24,4%) with FCA had primary metastatic/progressive disease. 12/21 patients with PCA and 12/16 with FCA showing up with recurrent disease had a negative iodinescan. 11/21 of patients with PCA and 4/16 with FCA and tumor recurrence had negative serum-TG levels. 14/62 patients with PCA and 14/59 with FCA presenting with primary metastatic/ progressive disease had negative iodinescan. 14/62 patients with PCA and 6/59 with FCA had negative serum-TG. Conclusion: The prevalence of iodine-negative recurrent"/metastatic disease is in accordance to the literature, whereas the prevalence of TG-negative recurrent/metastatic was noted higher than reported previously. Thus, the commonly used follow-up scheme of DTC is confirmed. However, iodine scan should be regularly performed in patients with high risk of recurrence.

Changes in muscle cross-sectional area, muscle force, and jump performance during 6 weeks of progressive whole-body vibration combined with progressive, high intensity resistance training

OBJECTIVES

We hypothesized that progressive whole-body vibration (WBV) superimposed to progressive high intensity resistance training has greater effects on muscle cross-sectional area (CSA), muscle force of leg muscles, and jump performance than progressive high intensity resistance training alone.

METHODS

Two groups of healthy male subjects performed either 6 weeks of Resistive Vibration Exercise (RVE, squats and heel raises with WBV, n=13) or Resistive Exercise (RE, squats and heel raises without WBV, n=13). Squats under RVE required indispensable weight loading on the forefoot to damp harmful vibrations to the head. Time, intervention, and interaction effects were analyzed.

RESULTS

After 6 weeks of training, knee extensor CSA, isometric knee extension force, and counter movement jump height increased equally in both groups (time effect, P⟨0.001, P≤0.02, and P≤0.03, respectively), whereas only in RVE ankle plantar flexor CSA and isometric ankle plantar flexion force reached significance or a tendency, respectively, (time effect, P=0.015 and P=0.069, respectively; intervention effect also for the latter, P=0.006). Drop jump contact time did significantly more improve in RVE (interaction effect, P=0.042).

CONCLUSIONS

RVE showed better training effects than RE only in plantar flexor muscles. RVE seems to be suitable in professional sports with a special focus on calf muscles.

The repeated bout effect: is the blunted creatine kinase response an effect of an altered enzyme inactivation kinetic?

AIM

If unaccustomed lengthening contractions are repeated within a certain period of time, muscle damage symptoms are blunted. This observation, often referred to as the repeated bout effect (RBE), also holds true for the response of muscle damage markers like creatine kinase (CK). However, measuring plasma enzyme activity rather than the concentration of enzyme protein might conceal the actual amount of damaged tissue. Therefore, the primary aim of the study was to investigate if the RBE of CK can partially be explained by enzyme inactivation.

METHODS

Ten healthy male subjects performed two bouts of 100 drop-to-vertical jumps (DVJs) from a 70-cm high platform at an interval of three weeks. CK activity, CK concentration, and neutrophils were measured prior to, and on four consecutive days after the interventions.

RESULTS

Besides significant main effects, there was a significant group by time interaction for the specific CK activity (CK activity in blood [U/L] divided by the enzyme concentration [ng/mL]). Higher values following the first bout (133.1±99.4 U/µg) than the second bout (94.7±63.0 U/µg) indicate that the ratio of inactive to active CK molecules increased. Neutrophil levels were similar following both bouts and differed only at 8 hours (7.0±2.5 bout 1, 5.1±1.6 bout 2).

CONCLUSION

The findings of the present study support the hypothesis that the blunted response of CK activity after a repeated bout of eccentric exercise is not solely the result of tissue protection, but can be at least partially attributed to enzyme inactivation.

Acute effects of superimposed electromyostimulation during cycling on myokines and markers of muscle damage

OBJECTIVES

The purpose of the present study was to evaluate the effects of superimposed electromyostimulation (E) during cycling on myokines and markers of muscle damage, as E might be a useful tool to induce a high local stimulus to skeletal muscle during endurance training without performing high external workloads.

METHODS

13 subjects participated in three experimental trials each lasting 60 min in a randomized order. 1) Cycling (C), 2) Cycling with superimposed E (C+E) and 3) E. Interleukin-6 (IL-6), brain-derived neurotrophic factor (BDNF), creatine kinase (CK) and myoglobin were determined before (pre) and 0', 30', 60', 240' and 24h after each intervention.

RESULTS

Only C+E caused significant increases in levels of CK and myoglobin. BDNF and IL-6 significantly increased after C and C+E, however increases for IL-6 were significantly higher after C+E compared to C.

CONCLUSION

The present study showed that superimposed E during cycling might be a useful tool to induce a high local stimulus to skeletal muscle even when performing low to moderate external workloads. This effect might be due the activation of additional muscle fibers and mild eccentric work due to the concomitant activation of agonist and antagonist. However the higher load to skeletal muscle has to be taken into account.

Active vs. passive recovery during high-intensity training influences hormonal response

The aim of the present study was to compare the effects of active (A) vs. passive (P) recovery during high-intensity interval training on the acute hormonal and metabolic response. Twelve triathletes/cyclists performed four 4 min intervals on a cycle ergometer, either with A- or P-recovery between each bout. Testosterone, hGH, cortisol, VEGF, HGF and MIF were determined pre, 0', 30', 60' and 180' after both interventions. Metabolic perturbations were characterized by lactate, blood gas and spirometric analysis. A-recovery caused significant increases in circulating levels of cortisol, testosterone, T/C ratio, hGH, VEGF and HGF. Transient higher levels were found for cortisol, testosterone, hGH, VEGF, HGF and MIF after A-recovery compared to P-recovery, despite no differences in metabolic perturbations. A-recovery was more demanding from an athlete's point of view. Based on the data of testosterone, hGH and the T/C-ratio, as well as on the data of VEGF and HGF it appears that this kind of exercise protocol with A-recovery phases between the intervals may promote anabolic processes and may lead to pro-angiogenic conditions more than with P-recovery. These data support the findings that also the long term effects of both recovery modes seem to differ, and that both can induce specific adaptations.

Acute metabolic, hormonal, and psychological responses to different endurance training protocols

In the last years, mainly 2 high-intensity-training (HIT) protocols became common: first, a Wingate-based "all-out" protocol and second, a 4×4 min protocol. However, no direct comparison between these protocols exists, and also a comparison with high-volume-training (HVT) is missing. Therefore, the aim of the present study was to compare these 3 endurance training protocols on metabolic, hormonal, and psychological responses. Twelve subjects performed: 1) HVT [130 min at 55% peak power output (PPO)]; 2) 4×4 min at 95% PPO; 3) 4×30 s all-out. Human growth hormone (hGH), testosterone, and cortisol were determined before (pre) and 0', 30', 60', 180' after each intervention. Metabolic stimuli and perturbations were characterized by lactate, blood gas (pH, BE, HCO₃⁻, pO₂, PCO₂), and spirometric analysis. Furthermore, changes of the person's perceived physical state were determined. The 4×30 s training caused the highest increases in cortisol and hGH, followed by 4 × 4 min and HVT. Testosterone levels were significantly increased by all 3 exercise protocols. Metabolic stress was highest during and after 4×30 s, followed by 4×4 min and HVT. The 4×30 s training was also the most demanding intervention from an athlete's point of view. In conclusion, the results suggest that 4×30 s and 4×4 min promote anabolic processes more than HVT, due to higher increases of hGH, testosterone, and the T/C ratio. It can be speculated that the acute hormonal increase and the metabolic perturbations might play a positive role in optimizing training adaptation and in eliciting health benefits as it has been shown by previous long term training studies using similar exercise protocols.

Acute hormonal responses before and after 2 weeks of HIT in well trained junior triathletes

The aim was to compare the acute hormonal response to a single HIT session at the beginning and end of a HIT shock microcycle. 13 male junior triathletes (15.8±1.8 yrs.) performed 16 HIT sessions within a 2 week period. Venous blood samples were collected before and after the first and last HIT session. Significant increases in cortisol (first session +89.7%; last session +70.3%) and hGH (first session +435.1%; last session +314.6%) concentrations were observed after both training sessions (P<0.05). The acute responses of cortisol, hGH, T3, and fT3 were not different between the first and last HIT sessions (P=1.00). Although no acute changes in testosterone were detected after the training sessions, testosterone concentrations were significantly higher at all time points (62.6-80.1%) during the last compared to first training session (P≤0.001). Findings from the present study reveal that 16 sessions of HIT led to significant increases in baseline concentrations of serum testosterone. This might indicate a heightened anabolic state even in junior triathletes. Based on the hormonal data, we conclude that at the end of this 2 week microcycle no familiarization effect was evident and that the training stimulus produced by HIT was still great enough to "stress" the athletes and induce positive training adaptations.

Randomized controlled study on resistive vibration exercise (EVE study): protocol, implementation and feasibility

OBJECTIVES

A training intervention comparing resistance exercise with or without whole-body vibration (WBV) was conducted to compare acute and chronic effects on functional and molecular parameters.

METHODS

A six-week training intervention was performed including 26 healthy males (26 years, SD=4). Two groups were analyzed in a parallel design performing either resistive exercise (RE, n=13) or resistive vibration exercise (RVE, n=13) training with weekly increasing vibration frequencies (20-40Hz). Resting and exercising blood pressure and heart rate were measured before and after the 6-week intervention.

RESULTS

Both training interventions decreased resting systolic blood pressure (P=0.003). Resting diastolic blood pressure was significantly decreased only in the RVE group (P=0.01). Exercising diastolic blood pressure was significantly decreased during the final training (P<0.001) with no additional effect of superimposed vibrations. Resistance exercise with superimposed vibrations evoked back pain to a higher degree than resistance exercise alone when training at frequencies above 30Hz (P<0.01).

CONCLUSIONS

These data suggest positive effects of resistance exercise upon cardiovascular health and vascular responsiveness and a further beneficial effect of superimposed vibrations in decreasing resting diastolic blood pressure. Finally, development of back pain may be fostered by superimposed vibrations to high training loads, particularly at higher frequencies.

Responses of angiogenic growth factors to exercise, to hypoxia and to exercise under hypoxic conditions

The purpose of the present study was to compare the acute hormonal response of angiogenic regulators to a short-term hypoxic exposure at different altitudes with and without exercise. 7 subjects participated in 5 experimental trials. 2 times subjects stayed in a sedentary position for 90 min at 2000 m or 4000 m, respectively. The same was carried out again in combination with exercise at the same relative intensity (2 mmol∙L(-1) of lactate). The fifth trial consisted of 90 min exercise at sea level. Venous blood samples were taken under resting conditions, 0 and 180 min after each condition to determine VEGF, EPO, IL-6, IL-8 and IGF-1 serum concentrations. EPO, VEGF, and IL-8 showed increases only, when hypoxia was combined with exercise. IL-6 was increased after exercise, independent of altitude. IGF-1 showed no changes in any intervention. The present study suggests that short term hypoxic exposure combined with low intensity exercise is able to up-regulate angiogenic regulators, which might be beneficial to induce angiogenesis and to improve endurance performance. However, in some cases high altitudes are needed, or it can be speculated that exercise intensity needs to be increased.

Ergogenic effect of hyperoxic recovery in elite swimmers performing high-intensity intervals

This investigation tested the hypothesis that breathing oxygen-enriched air (F(i)O(2) =1.00) during recovery enhances peak (P(peak)) and mean power (P(mean)) output during repeated high-intensity exercise. Twelve elite male swimmers (21 ± 3 years, 192.1 ± 5.9 cm, 79.1 ± 8.2 kg) inhaled either hyperoxic (HOX) or normoxic (NOX) air during 6-min recovery periods between five repetitions of high-intensity bench swimming, each involving 40 maximal armstrokes. Oxygen partial pressure (pO(2)) and saturation (SO(2)), [H(+)], pH, base excess and blood lactate concentration were measured before and after all intervals. The production of the reactive oxygen species (ROS) hydrogen peroxide was measured before, directly after and 15 min after the test. P(peak) and P(mean) with HOX recovery were significantly higher than with NOX throughout the third, fourth and fifth intervals (P<0.001-0.04). With HOX, electromyography activity was lower during the third, fourth and fifth intervals than during the first (P=0.05-0.001), with no such changes in NOX (P=0.99). There were no differences in blood lactate, pH, [H(+)] or base excess and ROS production at any time point with either HOX or NOX recovery. These findings demonstrate that the P(peak) and P(mean) of elite swimmers performing high-intensity intervals can be improved by exposure to oxygen-enriched air during recovery.

Cardio-respiratory and metabolic responses to different levels of compression during submaximal exercise

OBJECTIVE

The effects of knee-high socks that applied different levels of compression (0, 10, 20, 30 and 40 mmHg) on various cardio-respiratory and metabolic parameters during submaximal running were analysed.

METHODS

Fifteen well-trained, male endurance athletes (age: 22.2 ± 1.3 years; peak oxygen uptake: 57.2 ± 4.0 mL/minute/kg) performed a ramp test to determine peak oxygen uptake. Thereafter, all athletes carried out five periods of submaximal running (at approximately 70% of peak oxygen uptake) with and without compression socks that applied the different levels of pressure. Cardiac output and index, stroke volume, arterio-venous difference in oxygen saturation, oxygen uptake, arterial oxygen saturation, heart rate and blood lactate were monitored before and during all of these tests.

RESULTS

Cardiac output (P = 0.29) and index (P = 0.27), stroke volume (P = 0.50), arterio-venous difference in oxygen saturation (P = 0.11), oxygen uptake (P = 1.00), arterial oxygen saturation (P = 1.00), heart rate (P = 1.00) and arterial lactate concentration (P = 1.00) were unaffected by compression (effect sizes = 0.00-0.65).

CONCLUSION

This first evaluation of the potential effects of increasing levels of compression on cardio-respiratory and metabolic parameters during submaximal exercise revealed no effects whatsoever.

Proliferation of breast cancer cells: regulation, mediators, targets for therapy

A majority of breast cancers (BC) display characteristics of epithelial cells and express estrogen receptors and/or HER-2 (a member of the epidermal growth factor receptor family). About one-fifth of BC is constituted of basal cells for which there is no specific category of proliferation regulators. Insulin-like growth factor (IGF) signaling is involved in most BC cells, irrespective of cell type. All inducers of cell proliferation employ transcriptional as well as non-transcriptional mechanisms to activate the cascade of cyclin-dependent kinases, which causes irreversible progression to the G1/S phase transition. We analyze the pathways of the different inducers that lead to this cascade. Several actors in the mitogenic signal transduction are required irrespective of the initial signal although their functions may differ: for example members of the mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3 kinase (PI3K) cascades. As some of these proteins are also involved in the cell survival mechanisms, they appear to be good targets for therapeutic intervention. In the case of the estrogen-dependent cells, complex interplay between the estrogen receptor (a conditional transcription factor), co-repressors and co-activators offers additional molecular targets for therapy. Besides, we have found that p21(WAF1), an inhibitor of cyclin-dependent kinases, can orient the cell to either proliferation or differentiation suggesting that at an early stage of BC development it may be possible to reverse the cellular changes associated with malignant transformation.

Computer simulations suggest that acute correction of hyperglycaemia with an insulin bolus protocol might be useful in brain FDG PET

AIM

FDG PET in hyperglycaemic subjects often suffers from limited statistical image quality, which may hamper visual and quantitative evaluation. In our study the following insulin bolus protocol is proposed for acute correction of hyperglycaemia (>7.0 mmol/l) in brain FDG PET. (i) Intravenous bolus injection of short-acting insulin, one I.E. for each 0.6 mmol/l blood glucose above 7.0. (ii) If 20 min after insulin administration plasma glucose is <or=7.0 mmol/l, proceed to (iii). If insulin has not taken sufficient effect step back to (i). Compute insulin dose with the updated blood glucose level. (iii) Wait further 20 min before injection of FDG. (iv) Continuous supervision of the patient during the whole scanning procedure.

METHODS

The potential of this protocol for improvement of image quality in brain FDG PET in hyperglycaemic subjects was evaluated by computer simulations within the Sokoloff model. A plausibility check of the prediction of the computer simulations on the magnitude of the effect that might be achieved by correction of hyperglycaemia was performed by retrospective evaluation of the relation between blood glucose level and brain FDG uptake in 89 subjects in whom FDG PET had been performed for diagnosis of Alzheimer's disease.

RESULTS

The computer simulations suggested that acute correction of hyperglycaemia according to the proposed bolus insulin protocol might increase the FDG uptake of the brain by up to 80%. The magnitude of this effect was confirmed by the patient data.

CONCLUSION

The proposed management protocol for acute correction of hyper glycaemia with insulin has the potential to significantly improve the statistical quality of brain FDG PET images. This should be confirmed in a prospective study in patients.

Unusual presentation of sarcoidosis of the breast

We report a case of sarcoidosis with an unusual radiological appearance. The patient was a 41-year-old asymptomatic woman who presented for a baseline screening mammogram, which revealed an asymmetric, slightly increased density in the upper outer quadrant of her left breast. Ultrasonography failed to demonstrate any mass. Her past medical history was remarkable for sarcoidosis. Stereotactic core biopsy revealed sarcoidosis diffusely infiltrating the breast parenchyma.

Serum testosterone and urinary excretion of steroid hormone metabolites after administration of a high-dose zinc supplement

OBJECTIVES

To investigate whether the administration of the zinc-containing nutritional supplement ZMA causes an increase of serum testosterone levels, which is an often claimed effect in advertising for such products; to monitor the urinary excretion of testosterone and selected steroid hormone metabolites to detect potential changes in the excretion patterns of ZMA users.

SUBJECTS

Fourteen healthy, regularly exercising men aged 22-33 years with a baseline zinc intake between 11.9 and 23.2 mg day(-1) prior to the study.

RESULTS

Supplementation of ZMA significantly increased serum zinc (P=0.031) and urinary zinc excretion (P=0.035). Urinary pH (P=0.011) and urine flow (P=0.045) were also elevated in the subjects using ZMA. No significant changes in serum total and serum free testosterone were observed in response to ZMA use. Also, the urinary excretion pattern of testosterone metabolites was not significantly altered in ZMA users.

CONCLUSIONS

The present data suggest that the use of ZMA has no significant effects regarding serum testosterone levels and the metabolism of testosterone in subjects who consume a zinc-sufficient diet.

Vibration training: benefits and risks

The main results of our recent several studies, i.e. the measurements of vibration training results for single case and group studies as well as the cardiovascular parameter measurements during vibrations and the corresponding hydrodynamic analysis, are summarized. Our studies and previous work all confirm that vibration training is an effective training method in order to improve maximal strength and flexibility as well as various other factors if the training is properly designed. Some recommendations regarding the proper ranges of frequencies, amplitudes and exposure duration of vibration training are made based on the existing vibration training practice and mechanism analysis, although much work remains to be carried out in order to set up clear rules for various groups of people so that maximal training results could be expected and in the meantime potential dangerous effects could be avoided. Cardiovascular parameter measurements confirm that total peripheral resistance (TPR) to the blood flow is increased during body vibration. Hydrodynamic analysis offers the mechanism for the increase of TPR through the deformation of vessels. As a reaction of compensation, more capillaries are probably opened in order to keep a necessary level of cardiac output needed for the body, resulting in more efficient gas and material metabolism between the blood and muscle fibres. This might be one of the reasons for the various potential beneficial effects of vibration training.

7-Bromoindirubin-3'-oxime induces caspase-independent cell death

Indirubin, an isomer of indigo, is a reported inhibitor of cyclin-dependent kinases (CDKs) and glycogen synthase kinase-3 (GSK-3) as well as an agonist of the aryl hydrocarbon receptor (AhR). Indirubin is the active ingredient of a traditional Chinese medicinal recipe used against chronic myelocytic leukemia. Numerous indirubin analogs have been synthesized to optimize this promising kinase inhibitor scaffold. We report here on the cellular effects of 7-bromoindirubin-3'-oxime (7BIO). In contrast to its 5-bromo- and 6-bromo- isomers, and to indirubin-3'-oxime, 7BIO has only a marginal inhibitory activity towards CDKs and GSK-3. Unexpectedly, 7BIO triggers a rapid cell death process distinct from apoptosis. 7-Bromoindirubin-3'-oxime induces the appearance of large pycnotic nuclei, without classical features of apoptosis such as chromatin condensation and nuclear fragmentation. 7-Bromoindirubin-3'-oxime-induced cell death is not accompanied by cytochrome c release neither by any measurable effector caspase activation. Furthermore, the death process is not altered either by the presence of Q-VD-OPh, a broad-spectrum caspase inhibitor, or the overexpression of Bcl-2 and Bcl-XL proteins. Neither AhR nor p53 is required during 7BIO-induced cell death. Thus, in contrast to previously described indirubins, 7BIO triggers the activation of non-apoptotic cell death, possibly through necroptosis or autophagy. Although their molecular targets remain to be identified, 7-substituted indirubins may constitute a new class of potential antitumor compounds that would retain their activity in cells refractory to apoptosis.

Analysis of tuberculosis surveillance in Hungary in 2000

SETTING

Hungary, Central Europe, with a population of 10.3 million living in 20 administrative districts (19 counties and the capital).

OBJECTIVE

To summarize the results of the first year of the revised National Tuberculosis Surveillance System.

DESIGN

Retrospective survey of the National Tuberculosis Surveillance Center (NTSC) database.

METHODS

Analysis of data on all tuberculosis cases reported to the NTSC in 2000. Drug susceptibility results were evaluated in line with WHO and IUATLD definitions.

RESULTS

During 2000, a total of 3598 patients with tuberculosis were reported. Only 40% of these were bacteriologically confirmed. Although susceptibility testing has been required for previously untreated culture-positive cases, only 801 (67.8% of the bacteriologically confirmed cases) were tested in 2000. Drug resistance was detected in 10.7% of previously untreated and in 23.5% of previously treated patients. Multidrug-resistant (MDR) cases were not common: only 1.5% of the isolates from previously untreated patients and 4.9% of those from previously treated patients were MDR.

CONCLUSIONS

The results suggest that the NTSC should work towards increasing the numbers of cases that are bacteriologically confirmed. In addition, some form of surveillance system should be instituted to ensure that mandatory susceptibility testing is performed on all isolates from previously untreated tuberculosis patients.

A model analysis of internal loads, energetics, and effects of wobbling mass during the whole-body vibration

The internal loads, energetics, and the effects of wobbling mass during the whole-body vibration are studied in terms of analysis and comparison of two models: one is a system of four degrees-of-freedom with rigid and wobbling masses in both lower body and upper body (Model A), while the other one (Model B) is a system of three degrees-of-freedom with a rigid upper body and is otherwise identical to Model A. The main findings are the following: (1) The wobbling mass in the upper body is able to reduce the total internal load on the rigid mass of the upper body considerably. (2) "Partial" internal loads on a certain part of the body may be even larger than the total load on the same part of the body because of the phase differences among the partial loads. Therefore, a full consideration of safety during the whole-body vibration has to take not only the total, but also all the partial internal loads into account. (3) The fluctuation of power input and the fluctuation of mechanical energy could be much larger than the fluctuation of dissipation rate. (4) For frequencies higher than the resonance frequency range, the amplitude of the oscillation of the centre of mass of the body is so reduced that only the change of elastic potential energy dominates in the change of mechanical energy. Thus, a simple picture of energy flow is obtained as follows: for approximately one half of the oscillation period, the energy flows from the vibrator into the human body and is mainly stored in the muscle-tendon system, while for the remaining approximate half of the period, the energy flows from the muscle-tendon system back to the vibrator with a slightly smaller amount because a small part of the flown-in energy has been dissipated.

Molecular characterization of rifampin-resistant isolates of Mycobacterium tuberculosis from Hungary by DNA sequencing and the line probe assay

Two regions of rpoB associated with rifampin resistance were sequenced in 29 rifampin-resistant (determined by the proportion method) isolates of Mycobacterium tuberculosis obtained from patients from three counties in Hungary. Of the 29 resistant strains, 27 had a mutation in either the 81-bp region (26 strains) or the N-terminal region (1 strain), while the other 2 strains had no mutations in either region. The locations and frequencies of the mutations differed from those previously reported. The most common mutation in this study, D516V, was found in 38% of the Hungarian strains, a frequency 2 to 10 times higher than that found in studies from other countries. These same 29 isolates were also evaluated with the Inno-LiPA Rif. TB test (LiPA), a reverse hybridization assay for the rapid detection of rifampin resistance. Although LiPA detected the presence of an rpoB mutation in 26 of the resistant isolates, the type of mutation could not be determined in 4 isolates because the mutations present were not among those included on the LiPA strip. In addition, a silent mutation in one of the rifampin-susceptible control strains was interpreted as rifampin resistant by LiPA. These findings demonstrate the importance of validating this rapid molecular test by comparison with DNA sequence results in each geographic location before incorporating the test into routine diagnostic work.

[Prevalence of iodine- and thyroglobulin-negative findings in differentiated thyroid cancer.A retrospective analysis of patients treated from 1951 to 1998 in university hospital]

AIM

The prevalence of iodine- and thyroglobulin-negative findings was evaluated in all patients with differentiated thyroid cancer (DTC) treated from 1961 until 1998 at the Department of Nuclear Medicine, University Hospital Hamburg-Eppendorf.

METHODS

A total of 490 patients with papillary thyroid cancer (PCA) and 242 patients with follicular thyroid cancer (FCA) were analyzed retrospectively. Patients were divided into four groups: 1: no recurrence, 2: recurrent disease, 3: primary metastatic/progressive disease and 4: inconclusive follow-up. Results of iodine scan, serum-TG, and additional imaging modalities as well as histology were compared in all patients.

RESULTS

21/490 (4.3%) of patients with PCA and 16/242 (6.6%) with FCA suffered from recurrent disease. 62/490 (12.7%) of patients with PCA and 59/242 (24.4%) with FCA had primary metastatic/progressive disease. 12/21 patients with PCA and 12/16 with FCA showing up with recurrent disease had a negative iodinescan. 11/21 of patients with PCA and 4/16 with FCA and tumor recurrence had negative serum-TG levels. 14/62 patients with PCA and 14/59 with FCA presenting with primary metastatic/progressive disease had negative iodinescan. 14/62 patients with PCA and 6/59 with FCA had negative serum-TG.

CONCLUSION

The prevalence of iodine-negative recurrent/metastatic disease is in accordance to the literature, whereas the prevalence of TG-negative recurrent/metastatic was noted higher than reported previously. Thus, the commonly used follow-up scheme of DTC is confirmed. However, iodine scan should be regularly performed in patients with high risk of recurrence.

Insulin-like growth factor binding proteins and mitogenic activity of partially fractionated sheep amniotic fluid

Amniotic fluid collected from ewes on various days of gestation was examined for the presence of insulin-like growth factor (IGF) binding proteins. IGF-binding proteins with a molecular mass of 40-45 kDa appeared at day 41 of gestation. The level of these major IGF-binding proteins increased during pregnancy and reached a maximum at day 106. Smaller IGF-binding molecules with an approximate molecular mass of 35 kDa and 25 kDa appeared at day 90, also reaching a concentration peak at day 106. The mitogenic activity of sheep amniotic fluid after chromatography on Sephadex G-50 was separated into two peaks. The peak having lower molecular mass corresponded to an elution profile of 125I-IGF-I. The first peak, having higher molecular mass, was eluted immediately after the void volume of column. Electrophoresis and ligand blotting showed that proteins in the first peak had similar properties as IGF-binding proteins.

Mitogenic activity of high molecular weight forms of insulin-like growth factor-II in amniotic fluid

Amniotic fluid (AF) collected from ewes and goats at mid gestation displayed mitogenic activity in mouse fibroblasts. Upon fractionation of this material by size exclusion chromatography, the mitogenic activity was resolved into two peaks, whose activity was inhibited by an anti-IGF type 1 receptor blocking antibody. One of the peaks contained IGF-I and IGF-II (mature form), whereas the other contained high M(r) precursor forms of IGF-II. The presence in this latter fraction of IGF-binding proteins (IGFBP) suggests that the AF IGFBPs do not efficiently inhibit the mitogenic activity of the high M(r) forms of IGF-II. In agreement with this conclusion, exogenous IGFBP-1 failed to affect this activity. Analysis of IGF-II in sheep AF showed that the AF concentrations of both forms of IGF-II increased dramatically from mid pregnancy until 106-120 days of gestation, and fell thereafter. The amniotic IGFBPs followed a similar evolution. High M(r) forms of IGF-II were also found in human AF, with a pattern of electrophoretic migration different from that of sheep. We suggest that the precursor forms of IGF-II may play an important role in foetal development.

Comparison of rate of development and rate of change for benign and malignant breast calcifications at the lumpectomy bed

OBJECTIVE

The study purpose was to evaluate the rate of development and the rate of change for benign and malignant breast calcifications at the lumpectomy bed.

MATERIALS AND METHODS

Retrospective review identified 53 new calcifications at the lumpectomy bed in patients with available mammograms and medical records. Breast Imaging Reporting and Data System (BI-RADS) categories were retrospectively assigned on the basis of initial prospective recommendation for yearly follow-up (category 2), 6-month follow-up (category 3), or biopsy (category 4 or 5). Outcomes were defined as benign for no recurrence at the lumpectomy bed on biopsy or follow-up and malignant if biopsy-proven at the lumpectomy bed.

RESULTS

The median rate of development after lumpectomy was 23 months (range, 2-174 months) for benign and 39 months (range, 15-112 months) for malignant calcifications. Fifteen (28%) of 53 calcifications were classified as BI-RADS category 3. Twelve (80%) of 15 were downgraded to BI-RADS category 2 at a median follow-up of 6.5 months (range, 6-16 months); none represented recurrent disease. Three (20%) of 15 were upgraded to BI-RADS category 4 at the 6-month follow-up, one despite stability (benign) and two for increasing pleomorphism (malignant). Nine (17%) of 53 calcifications were classified as BI-RADS category 4 or 5; six (67%) of the nine were malignant and three (33%) were benign at biopsy. Twenty-nine (55%) of 53 calcifications were classified as BI-RADS category 2, none representing recurrent disease.

CONCLUSION

Benign calcifications at the lumpectomy bed usually develop earlier than malignant calcifications, but the rate of development overlaps. Most calcifications initially placed in the probably benign category evolve quickly to more benign or more malignant morphology. Most calcifications heralding recurrence appear suspicious on first presentation.

Low-cost, small-animal shelf for simultaneously assessing several small animals with a whole-body PET scanner

OBJECTIVE

The purpose of this work was to establish a low-cost device for simple positioning of several small animals within a whole-body PET scanner.

METHODS

The device was designed as a stackable shelf for 3 x 3 animals, similar to a stackable shelf for wine bottles. It was constructed from ordinary PVC drain pipe and acrylic panes.

RESULTS

The shelf simplified accurate and reproducible positioning of the animals and, therefore, supported automatic data processing. Deterioration of image quality by attenuation of photons within the shelf itself was rather small.

CONCLUSION

The small-animal shelf is a useful, low-cost device for simultaneously assessing up to 9 small animals with a whole-body PET scanner.

B-ind1, a novel mediator of Rac1 signaling cloned from sodium butyrate-treated fibroblasts

Sodium butyrate is a multifunctional agent known to inhibit cell proliferation and to induce differentiation by modulating transcription. We have performed differential display analysis to identify transcriptional targets of sodium butyrate in Balb/c BP-A31 mouse fibroblasts. A novel butyrate-induced transcript B-ind1 has been cloned by this approach. The human homologue of this transcript contains an open reading frame that codes for a protein of 370 amino acids without known functional motifs. In transfected cells, the B-ind1 protein has been found to potentiate different effects of the small GTPase Rac1, such as c-Jun N-terminal kinase activation and transcriptional activity of nuclear factor kappaB (NF-kappaB). In addition, we have demonstrated that B-ind1 forms complexes with the constitutively activated Rac1 protein. To investigate the role of B-ind1 in Rac1 signaling, we have constructed several deletion mutants of B-ind1 and tested their ability to affect the activation of NF-kappaB by Rac1. Interestingly, the fragment encoding the median region of human B-ind1 acted as a dominant-negative variant to block Rac1-mediated NF-kappaB activity. These data define B-ind1 as a novel component of Rac1-signaling pathways leading to the modulation of gene expression.