Search PubMed⌕ Search

Biomedical subjects

S Ernst

Publications and source records attributed to S Ernst.

123 records · Page 7Linked to original sources
PubMedDate not supplied

Structural analysis of ricin and implications for inhibitor design.

Ricin is a potent cytotoxin with experimental and clinical uses; it has also been used as a poison. There is considerable interest in identifying or designing inhibitors of the toxin that could be administered as antidotes. The X-ray structure of ricin A-chain is known and a plausible mechanism of action has been proposed. This provides a structural and chemical framework around which inhibitors could be designed; such a structure-based project is underway. Computer programs such as DOCK, GRID, SYBYL, and CHEMX have been used to map the ricin A-chain binding site and to search for potential inhibitors. Inhibitor candidates can be assayed kinetically in a protein synthesis assay and binding can be observed crystallographically. Taken together, a workable search algorithm has been developed and initial tests indicate that at least one ricin A-chain inhibitor, pteroic acid, has been identified.

Animals↗
PubMedDate not supplied

MR sialography: initial experience using a T2-weighted fast SE sequence.

PURPOSE: The aim of this study was to evaluate an MR technique optimized for imaging of the parotid gland ductal system. METHOD: The pulse sequence was optimized in 10 volunteers to depict static or nearly static fluid in the parotid ductal system. A heavily T2-weighted fast SE sequence (TR 3,600 ms/TE 800 ms) with a slice thickness of 30-40 mm using an 8 cm surface coil allowed depiction of the fluid-filled parotid duct. Thirteen patients with benign as well as malignant parotid gland pathologies were examined: sialadenitis (n = 2), sialadenosis (n = 3), Heerfordt syndrome (n = 1), pleomorphic adenoma (n = 2), parotid carcinoma (n = 1), lymphoepithelial carcinoma (n = 1), cystadenolymphoma (n = 2), and non-Hodgkin lymphoma (n = 1). RESULTS: The heavily T2-weighted projection image yielded good quality sialographic images. The main duct and primary branching ducts were clearly depicted in all normal cases. The main duct was visualized in all patients. Intra- and extraglandular duct widening and ductal strictures were well depicted. Sialolithiasis with a calculus in the main duct was correctly demonstrated in one case. CONCLUSION: MR sialography is noninvasive and does not depend on duct cannulation or contrast agent injection. Initial experience with a thick slice projection technique indicates that MR sialography can be successfully applied to image the parotid gland ductal system.

Adenolymphoma↗
PubMedDate not supplied

A method for the induction of a cochlea-specific auditory deprivation in the gerbil (Meriones unguiculatus).

The neurophysiological effects of early electrical stimulation on the development and neural plasticity of the central auditory system in prelingually deafened children with cochlear implants are still unknown. Many of these basic questions can be answered systematically only in animal experiments. Meriones unguiculatus is a well-established animal model in hearing research. Deafening is produced by a single intracochlear application of an ototoxic aminoglycoside antibiotic (neomycin sulfate) on the 14th day after birth (DAB), i.e. before the late natural onset of hearing on the 16th DAB. A single application of the antibiotic abolishes auditory brainstem responses (ABR) to clicks completely and reduces sensitivity to low frequency tonebursts by 50 dB SPL. Scanning electron microscopy results show a destruction of the stereocilia of the inner and outer hair cells of the basal and medial cochlear turn and a reduction of those in the apical turn. Our method avoids a systemic application of antibiotics and can be used in studies dealing with the consequences of different forms of auditory deprivation, neuronal compensation processes or with ontogenetic studies and chronic electrostimulation in an animal model.

Acoustic Stimulation↗
PubMedDate not supplied

[Analysis of some variables in patients with hydatidosis surgically treated at the Regional Hospital of Valdivia, Chile, 1976-1986].

A survey of surgically treated cases of hydatidosis in the province of Valdivia, Chile, was done. Data were provided by the Regional Hospital of Valdivia, and a period of eleven years was covered (1976-1986). Disease, treatment and related data from each patient were consigned. For the analysis, the information was grouped according to: sex, age, cyst location, condition of the cyst, concomitance with another pathology, condition at time of discharge, hospitalization period and number of repeat hospitalizations. In the period studied, 197 cases of hydatidosis were surgically treated. The sex distribution was 53.3% for males and 46.7 for females; the age group 10-19 years was the most affected by the disease (19.3%). The most frequent locations of hydatid cysts were the liver (58.9%) and lungs (36.5%); the 38.6% of the patients showed complicated cysts, mainly with bacterial infections (11.7%); also, 20% of the cases presented a concomitant liver-related pathology. After the operation, 153 (77.7%) clinically recovered and 27 (13.7%) non-recovered patients left the hospital and 7 (3.5%) cases died while hospitalized. The average hospitalization period was 29 days. During 1976-1986, 24 patients were rehospitalized.

Adolescent↗
PubMedDate not supplied

[Presence of extracranial cerebral arterial lesions in patients undergoing open heart surgery: a planned approach to a single stage operation (author's transl)].

The combined approach of extracranial arterial lesions in patients undergoing open heart surgery decreases the high cardiac and neurological morbidity and mortality presented by patients operated sequentially. Besides the anatomically sound simultaneous approach of arch lesions and heart surgery, both to be operated by median sternotomy, the authors present their criteria used in the selection of neurologically symptomatic and asymptomatic patients with carotid and vertebral disease to be operated simultaneously. Results in 17 personal cases are presented.

Aorta, Thoracic↗
PubMedDate not supplied

[Human hydatidosis in Valdivia, Chile: retrospective survey at the Valdivia Regional Hospital. 1987-1991].

A retrospective hospital survey of surgically confirmed cases of hydatidosis in the province of Valdivia was carried out. Data were provided by the Valdivia Regional Hospital and a five year (1987-1991) period was covered. Morbidity, mortality and case fatality rates were calculated. Descriptive epidemiological characteristics of the disease were determined. In the period studied, 137 new cases were registered. The incidence rate for the period was 9.1 per 100,000 inhabitants. The mortality rate was 0.2 per 100,000 inhabitants and the average fatality rate was 2.2%. The over-all sex distribution was 51.8% for females and 48.2% for males. The age group 10-19 years was the most affected by the disease (30.7%). The distribution according to activity revealed a higher proportion of house-wives (29.2%) and students (23.2%) with the disease. Hydatidosis was more frequent in Valdivia (23.4%), Panguipulli (17.5%) and La Unión (15.5%) and in patients from rural areas (73.7%).

Adolescent↗