Biomedical subjects

M Heckmann

Publications and source records attributed to M Heckmann.

78 records · Page 5Linked to original sources

PubMedDate not supplied

Neuromuscular glutamatergic and GABAergic channels.

Our laboratory has worked extensively on glutamatergic and GABA-ergic channels, predominantly in crayfish, but also in locust, Drosophila and recently Ascaris. Channel currents were recorded in the different modes of the patch-clamp technique (Hamill et al., 1981). The opening kinetics of the channels were derived from open and closed time histograms obtained from single channel recordings. From these, channel conductances could also be evaluated. The most relevant data were obtained by very rapidly rising and falling pulses (time of change about 0.1 ms) of agonists applied to outside-out patches containing the respective channels (Franke et al., 1987). From such recordings we constructed dose-response curves for peak and steady-state currents, for the rise times of the currents and for the time constants of desensitization. In double-pulse experiments we measured recovery from desensitization and predesensitization due to low agonist concentrations. For most of the channel types, we succeeded in constructing a reaction scheme which in computer simulations mimicked channel behaviour to a good approximation.

Animals↗

PubMedDate not supplied

[Adrenal function in very preterm infants in the early postnatal period].

In very premature infants of less than 30 weeks gestational age there is no correlation between the severity of illness and plasma cortisol concentrations. Low plasma cortisol levels were measured during critical illness with severe arterial hypotension requiring catecholamine treatment in the first two weeks of life. Thus, a relative adrenal insufficiency is suspected. The pituitary responds to CRH and the adrenal cortex to ACTH. But it is still questionable, wether the response is sufficient. Preterm infants with an impaired adrenal function in the first weeks of life seem to be at a higher risk for developing bronchopulmonary dysplasia. Steroids are effective in the treatment of arterial hypotension and bronchopulmonary dysplasia. Because of the broad spectrum of severe and long-term adverse effects, the treatment with glucocorticoids is recommended only after carefully balancing its benefits and risks.

Adrenal Cortex↗

PubMedDate not supplied

[Acute Renal Failure in Twin-to-Twin Transfusion Syndrome: Differential Diagnosis].

In the differential diagnosis of acute renal failure in Newborns prerenal, renal and postrenal causes must be considered. Additionally, in twin-to-twin transfusion syndrome especially the donor can suffer from acute renal failure caused by longterm intrauterine hypoperfusion of the kidneys resulting in severe retardation of renal development.

Acute Kidney Injury↗

PubMedDate not supplied

[Hemiconvulsion-Hemiplegia-Epilepsy-Syndrome (HHE)].

The pathogenesis of HHE is likely to be caused by prolonged focal convulsions responsible for a hypoxic cerebral edema. The decreased frequency of the syndrome could be explained by usually immediate drug-induced interruption of the seizure nowadays.

Brain Edema↗

PubMedDate not supplied

[Cervical myelopathy in a newborn with achondroplasia].

BACKGROUND: Patients with achondroplasia have an increased risk of apnoea due to cervical myelopathy. The indication for operative decompression can not be made by MRI alone, because signal alteration and osseous compression of the cervico-medullary region without functional relevance are frequent in this disease. CASE REPORT: We report on a male new-born with achondroplasia who displayed apnoeas from the first day of life. Two times, mask ventilation had to be performed. After exclusion of other diseases potentially causing apnoeas, an MRI of the skull and cervical spine revealed cervico-medullary compression due to foramen magnum stenosis, but no signal alterations of brain stem and cervical mark. Recording of somato-sensory evoked potentials (SSEP) of the median nerve showed normal potentials at Erb's point. By contrast, cortical potentials were distinctly abnormal during left-sided stimulation and could not be recorded during right-sided stimulation. Based on these findings, operative decompression of the craniocervical region was performed which led immediately to complete remission of clinical symptoms. At follow-up, MRI revealed a normal width of the foramen magnum and SSEP were markedly improved. CONCLUSION: In newborns with Achondroplasia, SSEP can confirm the functional relevance of osseous compression of the cervico-medullary region, and facilitate the decision for operative decompression.

Achondroplasia↗

PubMedDate not supplied

[Wegener's granulomatosis as a rare cause of hemoptysis in childhood].

Wegener's granulomatosis is together with Churg-Strauss syndrome and microscopic polyangiitis a very rare cause of hemoptysis in childhood. We report on a 14 years old girl who developed arthralgia, purpura, glomerulonephritis and a diffuse alveolar haemorrhage with hemoptysis after a short time period of unspecific symptoms.

Adolescent↗