Impaired and preserved aspects of independent finger control in patients with cerebellar damage.

The influence of the cerebellum on independent finger control has rarely been investigated. We examined multidigit control in 22 patients with cerebellar degeneration, 20 patients with cerebellar stroke, and 21 patients with surgical lesions after cerebellar tumor removal. In the first task, either the index finger or the middle finger was actively lifted from an object during static holding. Both controls and cerebellar patients increased the forces of the nearby digits in synchrony with lift-off to maintain the total finger force. Patients used increased finger forces but showed no significant deficits in the pattern and timing of rearrangement of finger forces. In the second task, subjects had to press and release one finger against a force-sensitive keypad with the other fingers being inactive. All patient groups showed increased force production of the noninstructed (enslaved) fingers compared with controls. Lesion-symptom mapping in the focal patients revealed that lesions of the superior hand area were related to abnormal levels of enslaving. Increased finger forces in the finger-lifting task likely reflect an unspecific safety strategy. Increased effects of enslaving in the individuated key-press task, however, may be explained by a deterioration of cerebellar contribution to feedforward commands necessary to suppress activity in noninstructed fingers or by increased spread of the motor command intended for the instructed finger. Despite the large and diverse patient sample, surprisingly few abnormalities were observed. Both holding an object and finger typing are overlearned, automatized motor tasks, which may not or little depend on the integrity of the cerebellum.

Bone morphogenetic protein receptor complexes on the surface of live cells: a new oligomerization mode for serine/threonine kinase receptors.

The bone morphogenetic proteins (BMPs) play important roles in embryogenesis and normal cell growth. The BMP receptors belong to the family of serine/threonine kinase receptors, whose activation has been investigated intensively for the transforming growth factor-beta (TGF-beta) receptor subfamily. However, the interactions between the BMP receptors, the composition of the active receptor complex, and the role of the ligand in its formation have not yet been investigated and were usually assumed to follow the same pattern as the TGF-beta receptors. Here we demonstrate that the oligomerization pattern of the BMP receptors is different and is more flexible and susceptible to modulation by ligand. Using several complementary approaches, we investigated the formation of homomeric and heteromeric complexes between the two known BMP type I receptors (BR-Ia and BR-Ib) and the BMP type II receptor (BR-II). Coimmunoprecipitation studies detected the formation of heteromeric and homomeric complexes among all the BMP receptor types even in the absence of ligand. These complexes were also detected at the cell surface after BMP-2 binding and cross-linking. Using antibody-mediated immunofluorescence copatching of epitope-tagged receptors, we provide evidence in live cells for preexisting heteromeric (BR-II/BR-Ia and BR-II/BR-Ib) and homomeric (BR-II/BR-II, BR-Ia/ BR-Ia, BR-Ib/ BR-Ib, and also BR-Ia/ BR-Ib) oligomers in the absence of ligand. BMP-2 binding significantly increased hetero- and homo-oligomerization (except for the BR-II homo-oligomer, which binds ligand poorly in the absence of BR-I). In contrast to previous observations on TGF-beta receptors, which were found to be fully homodimeric in the absence of ligand, the BMP receptors show a much more flexible oligomerization pattern. This novel feature in the oligomerization mode of the BMP receptors allows higher variety and flexibility in their responses to various ligands as compared with the TGF-beta receptors.

[Anomalies of the colour vision of women as an indication of testicular feminisation (author's transl)]. / Anomalien des Farbensinnes bei Frauen als Hinweis auf testikuläre Feminisierung.

When women show inborn anomalies of colour vision the syndroma of testicular feminization should be thought of as a possibility. In such cases the ophthalmologist should always ask the patient whether an amenorrhoea is present or ask for gynaecological examination.

[Blood-pressure regulating drugs and intraocular pressure in animal experiments (author's transl)]. / Blutdruckändernde Medikamente und Augeninnendruck im Tierversuch

Electromanometric measurements of blood pressure and intraocular pressure, carried out in rabbits after the intravenous administration of Norphen, Peripherin, Sympatol, Hydergin, Tropodil, Complamin, Euphyllin and Vasculat showed that the changes in the pressure curves were largely in the same sense. Apart from a "passive" correlation of the intraocular pressure with the blood pressure, the local effects of pharmaceuticals administered are also discussed. The results obtained provide both general medicine and ophthalmology with insights into the mode of action of drugs, some of which are frequently administered. In addition, they serve both to provide information on the desirable curative effects of the drugs and to help prevent damage being done to the organ of sight.