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Biomedical subjects

C Hermann

Publications and source records attributed to C Hermann.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Lower leg compartment syndrome after prolonged gynecologic surgeries in lithotomy position].

OBJECTIVE: How to prevent severe complications of lower leg compartment syndrome following gynecologic operations in the lithotomy position? MATERIAL AND METHODS: Two cases of lower leg compartment syndrome following long lasting gynecologic operations are presented. RESULTS: Early diagnosis by clinical signs, measurement of compartment pressure and creatine kinase activity and undelayed surgical intervention can avoid acute renal failure due to rhabdomyolysis and damage of neuromuscular function. CONCLUSIONS: Early diagnosis and undelayed surgical intervention can prevent severe complications of lower leg compartment syndrome following gynecologic operations in the lithotomy position.

Adult↗
PubMed1999

Effect of tumour necrosis factor-alpha on total myofibrillar and sarcoplasmic protein synthesis and polysomal aggregation in rat skeletal muscles.

The total sarcoplasmic and myofibrillar protein synthesis was reduced in incubated fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus of rat after in vivo tumour necrosis factor-alpha treatment at 50 micrograms/kg/day for 5 days. The rate of protein synthesis in the myofibrillar fraction was inhibited more severely (41% in EDL and 34% in soleus) than that in the sarcoplasmic fraction (23% in EDL and 14% in soleus). Sucrose density gradient centrifugation analysis indicated that TNF-alpha treatment impaired polysomal aggregation in rat diaphragm muscle. Compared with the control muscles, the ratio of 40S and 60S subunits to polysomes was higher in TNF-alpha treated muscles. These findings suggest a role for TNF-alpha in the translational regulation of protein synthesis in rat skeletal muscle.

Animals↗
PubMed1998

A trauma-like elevation of plasma cytokines in humans in response to treadmill running.

1. Elevated levels of cytokines, especially interleukin (IL)-6 and IL-1ra, can be measured in the plasma of athletes after exhaustive long term exercise. 2. The present study investigates the kinetics of several cytokines and chemokines in ten male athletes before, during and after 2.5 h of treadmill running at 75 % of maximal oxygen consumption (VO2,max). Blood was sampled before, every half-hour during running and every hour in the following 6 h recovery period. 3. The plasma concentration of IL-6 increased after 30 min of running, and peaked at the end of running with a 25-fold increase compared with the pre-exercise value. IL-1ra increased only after running, and peaked after 2 h of rest with an 18-fold increase compared with the pre-exercise value. No changes were found in the concentrations of IL-1beta, tumour necrosis factor (TNF)alpha, IL-15 and macrophage inflammatory protein (MIP)-1beta, and the concentrations of IL-8 and MIP-1alpha were below detection limits. 4. The results suggest that very early events in exercise trigger the release of IL-6, and that the cytokine response to exercise has similarities to that observed after trauma.

Adult↗
PubMed1998

Fluid shear stress stimulates phosphorylation of Akt in human endothelial cells: involvement in suppression of apoptosis.

Fluid shear stress alters the morphology and function of the endothelium by activating several kinases. Furthermore, shear stress potently inhibits apoptosis of endothelial cells. Since activation of Akt kinase has been shown to prevent cell death, we investigated the effects of shear stress on Akt phosphorylation. To test the hypothesis that shear stress interacts with the Akt kinase pathway, human umbilical venous endothelial cells were exposed to laminar shear stress (15 dyne/cm2). Western blotting with specific antibodies against the phosphorylated Akt demonstrated a time-dependent stimulation of Akt phosphorylation by shear stress with a maximal increase up to 6-fold after 1 hour of shear stress exposure. The stimulation of Akt phosphorylation by shear stress thereby seemed to be mediated by the phosphoinositide 3-OH kinase (PI3K), as evidenced by the significant inhibition of shear stress-induced Akt phosphorylation by the PI3K inhibitors wortmannin (20 nmol/L) and Ly294002 (10 micromol/L). In addition, pharmacological inhibition of P13K reduced the antiapoptotic effect of shear stress against growth factor depletion-induced apoptosis. Most important, overexpression of a dominant-negative Akt mutant significantly inhibited the apoptosis-suppressive effect of shear stress against serum depletion-induced apoptosis, thus indicating the direct involvement of shear stress-induced Akt phosphorylation for inhibition of endothelial cell apoptosis. These results define a novel shear stress-stimulated signal transduction pathway, namely, activation of the serine/threonine kinase Akt, which may contribute to the profound changes in endothelial morphology and function by shear stress.

Apoptosis↗
PubMed1998

Psychophysiological reactivity in pediatric migraine patients and healthy controls.

The hypothesis that physiological responses of migraine patients are symptom-specific was evaluated in 29 children (age range 8-16 years) suffering from migraine and 10 healthy control children. The assessment included two major stress phases and a relaxation period. A standard laboratory stressor (a subtraction task) and parent-child conflict served as stressors. A total of six physiological parameters were measured: pulse amplitude at two extracranial (A. temporalis, A. supraorbitalis) and one peripheral (index finger) sites; finger temperature; heart rate; and skin-conductance level. There were no significant group differences in autonomic arousal. Moreover, extracranial and peripheral vasomotor activity was not different between groups, a finding which might be partially due to the considerable interindividual variability. The implications of the results are discussed taking into account that studying pediatric rather than adult migraine patients allows to minimize the potentially confounding impact of factors such as headache chronicity, medication, and additional nonmigraine headaches.

Adolescent↗
PubMed1998

Vaccination of the civilian population in a country at war: it can be done; it can also be evaluated. The ICRC experience in Mozambique.

The medical division of the International Committee of the Red Cross undertook an expanded programme of immunization in rural areas of Mozambique controlled by the resistance. This programme was evaluated by a 30 cluster survey which showed that 82 per cent of children between 1 and 5 years and 81.7 per cent of mothers of children of less than 1 year had had contact with the vaccination service. Full vaccination was achieved in 40.6 and 35.2 per cent respectively. The reasons for immunization failure were established. The study shows that vaccination of the civilian population of a developing country at war is possible and, importantly, the outcome of the programme can be assessed.

Adult↗
PubMed1998

Apoptosis of endothelial cells. Contribution to the pathophysiology of atherosclerosis?

Endothelial cell injury is a key event in the pathogenesis of atherosclerosis. Importantly, endothelial cells in lesion-prone regions, where atherosclerotic lesions preferentially develop, are characterised by increased endothelial cell turn-over rates suggesting a mechanistic link between endothelial cell turn-over with preceding cell death and the susceptibility to atherosclerotic plaque development. The activation of the cellular suicide pathway leading to apoptosis of the endothelial cell may be an initial step in the development of atherosclerotic lesions. This hypothesis is supported by the finding that proatherosclerotic factors such as angiotensin II, oxidized low density lipoprotein, reactive oxygen species, glucose and inflammatory cytokines have all been shown to induce apoptosis of endothelial cells. In contrast, the known atheroprotective factors, such as oestrogen, nitric oxide or anti-oxidants, prevented endothelial cell apoptosis. Furthermore, laminar flow, which seems to be one of the most potent endogenous anti-atherosclerotic factor as illustrated by the focal nature of atherosclerotic lesion development in areas with turbulent or low blood flow, protects endothelial cell from apoptotic cell death. The present article summarizes the effects of pro and anti-atherosclerotic factors on endothelial cell apoptosis and provides insights into the underlying signalling events.

Animals↗
PubMed1997

Direction of temperature control in the thermal biofeedback treatment of vascular headache.

In order to test for the specific therapeutic effects of thermal biofeedback (TBF) for hand warming on vascular headache (HA), 70 patients with chronic vascular HA were randomly assigned to TBF for hand warming, TBF for hand cooling, TBF for stabilization of hand temperature, or biofeedback to suppress alpha in the EEG. Patients in each condition initially had high levels of expectation of therapeutic benefit and found the treatment rationales highly credible. Participants in each condition received 12 treatment sessions on a twice-per-week basis. Based on daily HA diary data gathered for 4 weeks prior to treatment and 4 weeks after treatment, HA Index was significantly (p = .003) reduced as was HA medication consumption. There were no differential reductions in HA Index or Medication Index among the four conditions. Global self-reports of improvement gathered at the end of the post-treatment monitoring period also did not differ among the four conditions. We were unable to demonstrate a specific effect of TBF for hand warming on vascular HA activity.

Adolescent↗
PubMed1997

Biofeedback treatment for pediatric migraine: prediction of treatment outcome.

Despite a growing number of studies showing good effectiveness of nonpharmacological treatments such as thermal biofeedback (TBF) for pediatric migraine, little is known about psychosocial variables that might be predictive of treatment outcome. The identification of predictors appears especially important when children are treated in a home-based treatment format that tends to be somewhat less effective than a therapist-administered treatment. A total of 32 children between the ages 8 and 16 years completed a home-based TBF treatment program with treatment outcome being of similar magnitude as previously reported in the literature. Multiple regression analysis revealed externalizing behavior tendencies, initial level of psychosomatic complaints, and the child's age to be highly predictive of outcome, whereas dimensions of family functioning failed to exert a direct influence. The implications of these findings for the development and evaluation of future treatment programs are discussed.

Adolescent↗
PubMed1997

Overactivation of the immune system by translocated bacteria and bacterial products.

Gut-derived bacteria and their constituents, namely endotoxins, contribute to the pathogenesis of septic multi-organ failure. Ischemia, trauma, chronic inflammation, immunosuppression or reduced blood flow in the gut are conditions that enhance bacterial translocation, which in turn activates the non-specific immune system, i.e. macrophages and granulocytes to release mediators of inflammation such as cytokines, eicosanoids and degranulation products. Besides blood leukocytes, the liver macrophage population (Kupffer cells), the majority of macrophages in the organism, is a central part of the defense. When overactivated this system can turn against the host, resulting in inflammatory organ damage such as liver injury. A variety of cell and animal models was used to characterize the response of blood and liver leukocytes stimulated by bacteria and bacterial wall preparations. Inflammatory hepatocytotoxicity was studied in vivo as well as in a coculture model of Kupffer cells and hepatocytes. A combination of tumor necrosis factor-mediated apoptosis and interleukin-1-mediated necrosis was identified as a crucial mechanism of endotoxin-inducible hepatocytotoxicity in vitro. Lactulose is believed to reduce bacterial translocation and could thus limit the adverse overactivation of the non-specific immune system. In addition, lactulose at high concentrations inhibited Kupffer cell release of inflammatory mediators and protected hepatocytes against macrophage toxicity. The clinical significance of this observation deserves further investigation.

Animals↗
PubMed1997

Shear stress inhibits H2O2-induced apoptosis of human endothelial cells by modulation of the glutathione redox cycle and nitric oxide synthase.

Physiological levels of shear stress reduce endothelial cell turnover and exert a potent antiatherosclerotic effect. Here we demonstrate that oxidative stress-induced apoptosis of human endothelial cells was inhibited by shear stress exposure (15 dynes/cm2). Incubation with H2O2 (200 mumol/L) for 18 hours induced apoptosis of human umbilical venous endothelial cells as demonstrated by an enzyme-linked immunosorbent assay specific for histone-associated DNA fragments and visual analysis of fluorescence-stained nuclei. Shear stress-mediated inhibition of apoptosis was partially prevented by pharmacological inhibition of glutathione (GSH) biosynthesis with buthionine sulfoximine (BSO) or nitric oxide (NO) synthase with NG-monomethyl-L-arginine (LNMA), whereas inhibition of catalase by aminotriazol did not affect the inhibitory action of shear stress. Combined inhibition of NO synthase and GSH biosynthesis completely reversed the protective effect of shear stress, suggesting that both NO synthase and the GSH redox cycle system are involved in the apoptosis-suppressing effect of shear stress. Similar results were obtained when apoptosis was stimulated by tumor necrosis factor alpha (TNF alpha). To gain further insights into the interference of shear stress with apoptosis signal transduction, we measured caspase-3-like activity, a cysteine protease that has been shown to play a predominant role in the cell death effector pathway. Indeed, shear stress prevented the activation of caspase-3-like activity induced by H202 or TNF alpha. The inhibitory effect of shear stress was prevented by LNMA and BSO, suggesting that the reduction of oxidative flux by shear stress prevents the activation of caspase-like proteases and thereby inhibits apoptotic cell death in human endothelial cells.

Apoptosis↗
PubMed1997

[99m-Tc-MIBI for recurrent and metastatic differentiated thyroid carcinoma].

AIM: The aim of the study has been the examination of the diagnostic value of 99mTc-MIBI scintigraphy for the detection of local tumor or metastases following total thyroidectomy and 131I ablation therapy in differentiated thyroid carcinoma. METHODS: MIBI-scintigraphy has been indicated in 85 patients because of ascending thyroglobulin values or suspected local recurrencies by ultrasonography. The results have been compared to cytology or histology or ultrasonography, computed tomography, X-ray and radioiodine scanning. RESULTS: MIBI scintigraphy was found positive in 32 of 40 metastases. Only 18 metastases have been seen by radioiodine. MIBI scintigraphy was most effective in detecting local tumor recurrencies and lymph node metastases (94%). The specificity of MIBI and radioiodine was similar (100%). In inflammatory enlarged lymph nodes no MIBI uptake was found, so it is possible to differentiate reactive lymph node enlargement from metastatic disease. CONCLUSION: In conclusion scintigraphy with 99mTc-MIBI is advisable in suspected local recurrencies and negative radioiodine scan. It is favourable that withdrawing TSH-suppressive hormone medication is not necessary.

Adult↗
PubMed1997

The effect of histone-mRNA interaction in protein synthesis.

The effect of lysine-rich and arginine-rich histones on selective inhibition of translation of mRNAs of tobacco mosaic virus (TMV), brome mosaic virus (BMV) and luciferase, in rabbit reticulocyte (RRL) was evaluated. Nuclease-treated RRL were supplemented with an appropriate mRNA and incubated with lysine-rich or arginine-rich histones at 5 and 2.5 micrograms/100 microliters lysate at 30 degrees C. Protein synthesis was measured as incorporation of 3H-leucine into protein for 24 min. The lysine-rich histone was more inhibitory than arginine-rich histone. At 5 and 2.5 micrograms/100 microliters lysate concentration, the lysine-rich histone inhibited translation of TMV mRNA by 57% and 35%, respectively, after 24 min. The corresponding values for arginine-rich histone were 31% and 13%. Both histones had a more inhibitory effect on the translation of viral mRNA than luciferase mRNA. Arginine-rich histone at 2.5 micrograms/100 microliters lysate did not cause any inhibition of luciferase mRNA. The spectrophotometric analysis of histone-mRNA mixtures at 280 nm indicated that, compared with arginine-rich histone, lysine-rich histone had a stronger affinity for mRNA.

Animals↗
PubMed1996

Slow potentials, event-related potentials, "gamma-band" activity, and motor responses during aversive conditioning in humans.

We examined slow potentials, transient event-related potentials, and oscillatory-like responses in the electroencephalogram during aversive conditioning in humans, in order to determine what is happening in the neocortex when behavioral adaptations are learned. Pictures of an angry and a happy human face served as reinforced (CS+) and unreinforced (CS-) conditioned stimuli, respectively, in one group, and either the reversed condition or two discriminably different neutral faces in two other groups (total n = 48 subjects). The unconditioned stimulus (US) was intracutaneous shock delivered to the left hand 5 s after CS+ onset. The electroencephalographic (EEG) activity was recorded from Fz, Cz, Pz, C3, and C4, electromyographic (EMG) activity from bilateral forearm and corrugator muscles, and skin conductance from the right hand. During acquisition a negative slow potential developed after CS+ (not CS-), which was more pronounced when a neutral face served as CS+. Early (iCNV, initial contingent negative variation) and late (tCNV, terminal contingent negative variation) components of the slow-potential response were positively related to the magnitude of conditioned EMG responses. Differentiation of tCNV was larger when neutral faces signaled the US; iCNV persisted during extinction when a happy face served as CS+. Late-occurring event-related potentials (ERPs) elicited by the US diminished over conditioning, whereas short-latency US components and ERPs elicited by CS events did not. Fourier analysis revealed oscillatory ("gamma-band") activity between 30 and 40 Hz, which persisted up to 3 s after US delivery and diminished as conditioning progressed. Our findings indicate that learning is expressed in neocortical structures at the earliest stages of conditioning. The functional roles of the three types of EEG response in learning are discussed.

Adult↗
PubMed1996

Thiopentone requirements in adults after varying pre-induction doses of fentanyl.

The thiopentone dose needed for satisfactory induction of anaesthesia was determined in 60 adult patients using a double-blinded study design. No premedication was given. The effect of pretreatment with four different doses of fentanyl on ED50 for thiopentone was determined and compared with a control group not receiving fentanyl. The cardiovascular effects of the combinations were also studied. ED50 for thiopentone was reduced from 4.0 mg.kg-1 in the control group to 2.2 mg.kg-1 in patients receiving fentanyl 5.0 micrograms.kg-1. Only in the group of patients receiving fentanyl 5.0 micrograms.kg-1 was there no significant change in systolic arterial blood pressure. An increased heart rate was noted in patients induced with thiopentone in combination with fentanyl 0.625 micrograms.kg-1. No adverse effects of thiopentone, fentanyl or the combinations were noted.

Adjuvants, Anesthesia↗
PubMed1995

Behavioral and prophylactic pharmacological intervention studies of pediatric migraine: an exploratory meta-analysis.

In this review, the effectiveness of behavioral and pharmacological treatments for pediatric migraine was quantitatively summarized following the meta-analytic approach outlined by Hedges and Olkin (1985). A first meta-analysis based on treatment outcome within treatment conditions revealed that thermal biofeedback and interventions combining biofeedback and progressive muscle relaxation seem to be significantly more efficacious than other behavioral treatment modalities, psychological and drug placebo, and the more commonly used prophylactic drug regimens. Though there is some evidence suggesting good effectiveness of propranolol, the lack of systematic data precludes more definitive conclusions. A second meta-analysis that included only studies providing data on the comparison between control versus active treatment conditions replicated the initial findings only partially. In the light of the relative small number of studies that met basic inclusion requirements, the methodological flaws of many studies, and the under-representation of certain treatment types, conclusions regarding differential effectiveness of the treatment types have to be drawn with caution. Overall, our findings clearly demonstrate the need for direct comparisons between behavioral and pharmacological treatments and the need for more theory-driven research in order to determine the most promising treatment approaches for pediatric migraine.

Behavioral Medicine↗