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Biomedical subjects

S Hesse

Publications and source records attributed to S Hesse.

123 records · Page 7Linked to original sources
PubMed1975

Significant pathways of hepatic ethanol metabolism.

Rat liver microsomes oxidized ethanol two to three times faster than propanol when incubated with either an NADPH- or an H2O2-generating system. In addition, solubilized, purified microsomal subfractions were found to contain protein with an electrophoretic mobility identical to rat liver catalase on SDS polyacrylamide gels, suggesting that the separation of catalase from cytochrome P-450 and other microsomal components may not be feasible. These data support the postulate that catalase is responsible for NADPH-dependent microsomal ethanol oxidation. Direct read-out techniques for pyridine nucleotides, the catalase-H2O2 complex, and cytochrome P-450 were utilized to evaluate the specificity of inhibitors of alcohol dehydrogenase (4-methylpyrazole; 4 mM) and catalase (aminotriazole; 1.0 g/kg) qualitatively in perfused rat livers. 4-Methylpyrazole and aminotriazole are specific inhibitors for alcohol dehydrogenase and catalase, respectively, under these conditions. Neither inhibitor nor a combination of them altered the mixed function oxygen of p-nitroanisole to p-nitrophenol as observed by oxygen uptake and product formation. When ethanol utilization was measured over the concentration range 20-80 mM in perfused liver, a concentration dependence was observed. At low concentrations of ethanol, ethanol oxidation was almost totally abolished by 4-methylpyrazole; however, the contribution of 4-methylpyrazole-insensitive ethanol uptake increased as a function of ethanol concentration. At 80 mM ethanol, ethanol utilization was nearly 50% methylpyrazole-insensitive. This portion of ethanol oxidation, however, was abolished by aminotriazole. The data indicate that alcohol dehydrogenase and catalase-H2O2 are responsible for hepatic ethanol oxidation. At low ethanol concentrations (less than 20 mM), alcohol dehydrogenase is predominant; however, at higher ethanol concentrations (up to 80 mM), the contribution of catalase-H2O2 to overall ethanol utilization is significant. No evidence that the endoplasmic reticulum is involved in ethanol metabolism in the perfused liver emerged from these studies.

1-Propanol↗
PubMedDate not supplied

Effect of urapidil on the performance of ischemic myocardium in anesthetized dogs.

Urapidil (URA) is used to treat acute hypertension in patients with coronary artery disease, but the effect of URA on the performance of ischemic myocardium has not yet been investigated. The present study was intended to assess the function of ischemic myocardium following URA administration. In eight anesthetized (piritramide) open-chest dogs systolic contraction (dL) and end-diastolic length (edL) of myocardium supplied by the left descending (LAD) and circumflex (LCA) coronary arteries were measured by sonomicrometry simultaneously with aortic pressure (AoP), left ventricular end-diastolic pressure (LVedP), heart rate (HR), stroke volume (SV), and LAD-flow (QLAD). QLAD was reduced by LAD stenosis to about 50% of control, decreasing dLLAD by 55%. Concomitantly, edLLAD increased by about 9% and LVedP by 22%, whereas AoP decreased by 5%. Then, URA was given i.v. (0.25 + 0.25 + 0.50 + 1.0 mg/kg) in 15-min intervals. Following URA, the performance of the non-ischemic area was not systematically affected, but dLLAD increased by about 50%. This could neither be related to the significant reduction in afterload (AoP: -8%), nor to an increase in preload (LVedP and edLLAD did not change significantly), nor to an improved oxygen supply via the LAD (QLAD even decreased), although an increased collateral flow the LCA could not be excluded. The increase in systolic shortening correlated very closely to a decrease in heart rate (r = -0.92). It is concluded that the improved function of ischemic myocardium following urapidil resulted from a reduced oxygen demand in consequence to the decrease in heart rate.

Animals↗
PubMedDate not supplied

[Giant vascular tumour in an adult: tufted angioma or kaposiform hemangioendothelioma].

INTRODUCTION: Tufted angioma and kaposiform hemangioendothelioma are two rare benign but aggressive vascular tumours that occur mainly in children. OBSERVATION: A 72 year-old man consulted for a 50 cm wide vascular tumour of the right shoulder which was increasing for 10 years. On histological examination there were features of tufted angioma and kaposiform hemangioendothelioma. DISCUSSION: The tumour of this patient was atypical because of its big size never described before. The histological association of aspects which could correspond to tufted angioma and kaposiform hemangioendothelioma seems to confirm recent publications which support the hypothesis that these two tumours are two evolutive stages of one and only entity.

Aged↗
PubMedDate not supplied

Keratitis, ichthyosis, and deafness (KID) syndrome in half sibs.

The keratitis, ichthyosis, and deafness (KID) syndrome is a rare congenital disorder of the ectoderm characterized by diffuse hyperkeratotic erythroderma, keratitis with neovascularization of the cornea, and severe neurosensory hearing loss. A familial occurrence of this syndrome has been mentioned in four reports including three of vertical transmission and one of two affected sisters born from consanguineous, unaffected parents. We report for the first time a familial case of KID syndrome in two half siblings born to the same unaffected mother. This new observation allows us to propose various hypotheses about its mode of inheritance.

Child, Preschool↗
PubMedDate not supplied

[The gait of patients with full weightbearing capacity after hip prosthesis implantation on the treadmill with partial body weight support, during assisted walking and without crutches].

PROBLEM: Treadmill training with partial body weight support is a new promising technique in the rehabilitation in hip arthroplasty patients. With little data on the gait pattern and extent of pelvitrochanteric muscle activation, this study analysed the gait of hip arthroplasty patients walking on the treadmill and also during floor walking with and without crutches. METHOD: Gait analysis in 19 hip arthroplasty patients capable of full weight bearing included the assessment of kinematics, kinetics and kinesiologic electromyogram of relevant trunk and lower limb muscles during treadmill walking with 15% of body weight support, and during floor walking with and without crutches at comparable walking velocities. RESULTS: Both on the treadmill and with crutches, patients walked less frequent, with a longer stride and more symmetric as compared to the unaided gait. Both techniques, however, resulted in a reduced activation of most of the pelvitrochanteric muscles, particularly when using crutches. The comparison of both supporting methods revealed a higher activity of the M. gluteus medius of the affected side on the treadmill. The amount of body weight reduction was comparable ranging from 10 to 15%. CONCLUSIONS: Treadmill training with constant body weight support enables hip arthroplasty patient to entrain a dynamic and symmetric gait pattern with a better activation of the hip abductor of the affected side as compared to walking with crutches. Nevertheless, the level of activation was less than when walking without crutches which, however, resulted in a limping gait pattern.

Aged↗
PubMedDate not supplied

The influence of treadmill inclination on the gait of ambulatory hemiparetic subjects.

INTRODUCTION: This study evaluated the influence of the degree of treadmill belt inclination for training of ambulatory patients with hemiparetic stroke. METHODS: Twelve patients were instructed to walk at 5 different levels of inclination (0%-8%) while harness-secured on the treadmill. The gait velocity was kept constant during all conditions. Dependent variables were heart rate, gait cycle-dependent parameters, and electromyographic activation patterns of the weight-bearing muscles. RESULTS: Heart rate increased across all inclination levels, stride length increased and cadence decreased, whereas swing symmetry improved due to shortening of the relative swing phase of the affected side at the 6% and 8% inclination levels. No change in the activation pattern of the leg muscles was found. CONCLUSION: An inclination up to at least 8% can be accommodated for treadmill training by ambulatory stroke patients. For a given belt speed, heart rate increased without exceeding critical levels and patients walked with a more symmetric pattern. This protocol appeared to be safe in this selected group of subjects.

Adult↗
PubMedDate not supplied

Gait initiation, development of a measuring device for use in a clinical environment.

Gait initiation is a part of daily mobility, its restoration thus plays a major role in the rehabilitation of hemiparetic patients that have a higher risk of falling. This study presents a clinically applicable system for the analysis of gait initiation of healthy persons and hemiparetic patients. For this purpose we have analysed the triaxial ground reaction forces yielding the displacement of the centre of pressure (CP) and, with a two-fold integration of ground reaction forces, the centre of mass (CM). These are descriptive parameters of the dynamics and symmetry of gait initiation that could predict the risk of falling. Hemiparetic patients showed a distinct behaviour when starting either with their affected or non-affected limb. Future applications include individual assessment of patients with gait disabilities and validation of physiotherapy strategies.

Biomechanical Phenomena↗
PubMedDate not supplied

[Development of a gait trainer with regulated servo-drive for rehabilitation of locomotor disabled patients].

The aim of the present study was to develop a new gait trainer for the rehabilitation of non-ambulatory patients. For the simulation of the gait phase, we used a commercially available fitness trainer (Fast Track) with two foot plates moving in an alternating fashion and connected to a servo-controlled propulsion system providing the necessary support for the movement depending on the patient's impairment level. To compensate deficient equilibrium reflexes, the patient was suspended in a harness capable of supporting some of his/her weight. Video analysis of gait and the kinesiological EMG were used to assess the pattern of movement and the corresponding muscle activity, which were then evaluated in healthy subjects, spinal cord injured and stroke patients and compared with walking on the flat or on a treadmill. Walking on the gait trainer was characterised by a symmetrical, sinusoidal movement of lower amplitude than in normal gait. The EMG showed a low activity of the tibialis anterior muscle, while the antigravity muscles were clearly activated by the gait trainer during the stance phase. In summary, the new gait trainer generates a symmetrical gait-like movement, promoting weight acceptance in the stance phase, which is important for the restoration of walking ability.

Adult↗
PubMedDate not supplied

Development of an advanced mechanised gait trainer, controlling movement of the centre of mass, for restoring gait in non-ambulant subjects.

The study aimed at further development of a mechanised gait trainer which would allow non-ambulant people to practice a gait-like motion repeatedly. To simulate normal gait, discrete stance and swing phases, lasting 60% and 40% of the gait cycle respectively, and the control of the movement of the centre of mass were required. A complex gear system provided the gait-like movement of two foot plates with a ratio of 60% to 40% between the stance and swing phases. A controlled propulsion system adjusted its output according to patient's efforts. Two eccenters on the central gear controlled phase-adjusted the vertical and horizontal position of the centre of mass. The patterns of sagittal lower limb joint kinematics and of muscle activation of a normal subject were similar when using the mechanised trainer and when walking on a treadmill. A non-ambulatory hemiparetic subject required little help from one therapist on the gait trainer, while two therapists supported treadmill walking. Gait movements on the trainer were highly symmetrical, impact-free, and less spastic. The weight-bearing muscles were activated in a similar fashion during both conditions. The vertical displacement of the centre of mass was bi-instead of mono-phasic during each gait cycle on the new device. In conclusion, the gait trainer allowed wheelchair-bound subjects the repetitive practice of a gait-like movement without overstraining therapists.

Adult↗
PubMedDate not supplied

A mechanized gait trainer for restoration of gait.

The newly developed gait trainer allows wheel-chair-bound subjects the repetitive practice of a gait-like movement without overstressing therapists. The device simulates the phases of gait, supports the subjects according to their abilities, and controls the center of mass (CoM) in the vertical and horizontal directions. The patterns of sagittal lower limb joint kinematics and of muscle activation for a normal subject were similar when using the mechanized trainer and when walking on a treadmill. A non-ambulatory hemiparetic subject required little help from one therapist on the gait trainer, while two therapists were required to support treadmill walking. Gait movements on the trainer were highly symmetrical, impact free, and less spastic. The vertical displacement of the CoM was bi-phasic instead of mono-phasic during each gait cycle on the new device. Two cases of non-ambulatory patients, who regained their walking ability after 4 weeks of daily training on the gait trainer, are reported.

Adult↗
PubMedDate not supplied

High negative predictive value of slow lymphatic drainage on metastatic node spread detection in malignant limb and trunk cutaneous melanoma.

AIM: Harvesting of the "sentinel lymph node" (SLN) as identified by lymphoscintigraphy (LSG) is becoming increasingly important in the staging of patients with malignant melanoma. The purpose of the current study was to determine whether the appearance time of the LSG had a prognostic value in predicting metastasis dissemination in thick cutaneous malignant melanoma. METHODS: Between July 1999 and July 2003, 88 consecutive patients with histologically proven melanoma with a Breslow's thickness > 1 mm, without clinical or radiological evidence of lymph node involvement or metastasis, prospectively underwent lymphoscintigraphy with 32 Mbq Tc 99m sulfur colloid prior to sentinel lymphadenectomy with sentinel lymph node (SLN) histological examination. RESULTS: LSG was performed in 88 patients with limb and trunk melanoma and identified a total of 149 sentinel nodes. Pathological examination revealed lymph node involvement in 21 patients (24%). All positive SLNs were imaged with a scintigraphic appearance time of less than 30 min. With a scintigraphic appearance time greater than 30 min, the negative predictive value (NPV) of spread in the SLN was 100% (27/27)(CI 87-100%). CONCLUSION: The strong NPV of LSG in identifying "slow" sentinel lymph nodes in patients with no clinical evidence of lymph node involvement suggests that patients could be spared sentinel lymph node biopsy when LSG detects "slow" sentinel lymph nodes. Another prospective study will be required to confirm that the scintigraphic appearance time of sentinel lymph nodes is an important predictive parameter of metastatic disease in sentinel lymph nodes and consequently might reduce the number of sentinel lymph node biopsies.

Adult↗