Biomedical subjects

R Zobrist

Publications and source records attributed to R Zobrist.

6 recordsLinked to original sources

PubMed2006

A less invasive anterior intrapelvic approach for the treatment of acetabular fractures and pelvic ring injuries.

BACKGROUND: The ilioinguinal approach by Letournel has fundamentally contributed to the successful treatment of acetabular fractures. Since most of the present complications arise from soft tissue structures in the inguinal part, it would be desirable to avoid the surgical dissection of this region. We have therefore developed a less invasive anterior intrapelvic approach consisting of a suprapubic access combined with the lateral window of the ilioinguinal approach. METHODS: Between January 2000 and October 2002, 14 patients with acetabular fractures and 6 patients with pelvic ring injuries were consecutively operated using our technique. The patients were prospectively followed up clinically and by standard X-rays for 1 year. RESULTS: In 19 patients the technique was successful and only one patient was converted to an ilioinguinal approach due to difficulties in reducing the fracture. Our access allowed good visibility but reduction manoeuvres were sometimes difficult and the development of a new reduction forceps became necessary. Anatomical and satisfactory reduction was achieved in 13 acetabular fractures and 4 pelvic ring injuries. One cutaneous femoris neurapraxy and one superficial infection occurred related to the approach and both resolved with conservative treatment. Clinical outcome at one year was good to excellent in 17 patients (modified Merle d'Aubigné/Postel score). In 3 patients the result was fair to poor for reasons unrelated to the approach. CONCLUSIONS: Our approach permits visualisation of the entire anterior column and pelvic ring without the necessity to dissect the inguinal neurovascular structures. Our preliminary results demonstrate that safe reduction and stable fixation of selected acetabular- and pelvic ring fractures are possible.

Acetabulum↗

PubMed2002

[Endoscopically controlled stabilization of humerus shaft fractures. The endoscope as an aid in minimally invasive osteosynthesis].

This study describes the anatomical basis of direct visualization of the radial nerve and of fracture reduction in humeral shaft nailing and reports first clinical results. Fourteen cadavers were random selected and dissected in order to determine the exact course of the radial nerve in relationship to anatomical landmarks. In individuals with a total humeral length between 25-33 cm the radial nerve was found to cross the humeral shaft exactly in the middle of the long axis of the humeral shaft. The average distance from the lateral epicondyle to the point were the radial nerve penetrates the lateral intermuscular septum was 11.9 +/- 1.0 cm, the distance from the posterior tip of the acromion to the crossing of the nerve with the medial border of the humeral shaft was 12.9 +/- 1.5 cm. Using these landmarks in six clinical cases fracture reduction, visualization of the radial nerve and intramedullary nailing could be achieved with endoscopic control. There were no surgical complications such as secondary radial nerve palsy, hematomas or wound healing problems. With the use of the endoscope the number of secondary radial nerve palsies associated with intramedullary humeral shaft nailing might be reduced in the future.

Adult↗

PubMed1998

Use of the balloon dissector in minimally invasive aesthetic and reconstructive surgery.

The use of minimally invasive surgery continues to evolve in all fields of surgery with new developments in techniques and instrumentation. One instrument that has evolved and become useful in the field of plastic surgery is the balloon dissector. The purpose of this paper is to examine the role of the balloon dissector in minimally invasive aesthetic and reconstructive plastic surgery. We define the concept of the fascial cleft-the loose areolar space between fascial linings. In addition, the balloon dissector and its use is described. The optical cavity created by the balloon dissector device is discussed, along with the two techniques used to maintain the optical cavity, and manual retraction and carbon dioxide insufflation. The application of the balloon dissector in various regions of the body is discussed along with its use in free tissue transfers. Three patients are presented to illustrate the application of the balloon dissector.

Adult↗

PubMed1997

Preclinical characterization of MDL 27,192 as a potential broad spectrum anticonvulsant agent with neuroprotective properties.

The compound 5-(4-chlorophenyl)-2,4-dihydro-4-ethyl-3H-1,2,4-triazol-3-one (MDL 27,192) was evaluated in a variety of rodent models to assess its anticonvulsant profile and its potential neuroprotective activity. MDL 27,192 demonstrated anticonvulsant activity in a wide range of epilepsy models that are genetically-based (audiogenic seizures in the seizure susceptible DBA/2J or Frings mouse; spike wave seizures in genetic absence epilepsy rats of Strasbourg (GAERS), electrically-based (MES seizures in mice and rats, corneally-kindled seizures in rats) and chemically-based (bicuculline, PTZ, picrotoxin, 3-mercaptopropionic acid, quinolinic acid and strychnine). When compared to valproate, orally administered MDL 27,192 was 17-48-fold more potent as an anticonvulsant and showed a safety index one to three-fold greater. Following a timed intravenous administration of PTZ to mice, MDL 27,192, but not phenytoin or carbamazepine, consistently increased the latencies to first twitch and clonus. MDL 27,192 was active in a genetic model of absence epilepsy, the GAERS rat model. These data indicate that MDL 27,192 likely exerts its anticonvulsant action by affecting seizure spread and by raising seizure threshold. MDL 27,192 did not display any signs of tolerance following subchronic (15 day) administration. In tests of neuroprotective potential, MDL 27,192 reduced infarct volume in a permanent middle cerebral artery occlusion model of focal cerebral ischemia in rats and reduced the loss of hippocampal dentate hilar neurons in an animal model of unilateral head injury. In summary, MDL 27,192 possesses a broad-spectrum anticonvulsant profile. The potential for reduced tolerance and neuroprotective activity are additional positive features of MDL 27,192's preclinical profile.

Animals↗

PubMed1992

Effect of flunarizine and nimodipine on the decrease in tryptophan hydroxylase activity induced by methamphetamine and 3,4-methylenedioxymethamphetamine.

The effect of calcium channel blockers on the decrease in central tryptophan hydroxylase (TPH) activity and serotonin (5-HT) concentration induced by repeated large doses of methamphetamine (METH) or 3,4-methylenedioxymethamphetamine (MDMA) was evaluated. Rats received four or five injections of METH (10 or 15 mg/kg) or MDMA (10 mg/kg) at 6-h intervals, and were sacrificed 18 to 20 h or 1 week after the last administration. Flunarizine (30 mg/kg) prevented the decline in cortical and neostriatal TPH activity induced by MDMA, but failed to alter the effect of METH. The effect of flunarizine on the METH- and MDMA-induced changes in cortical 5-HT and 5-hydroxyindoleacetic acid concentrations paralleled the changes in enzyme activity. Nimodipine, diltiazem or TA-3090 failed to prevent the MDMA- and the METH-induced decline in TPH activity or in 5-HT and 5-hydroxyindoleacetic acid content. Because haloperidol failed to mimic the protective action of flunarizine, it is unlikely that flunarizine exerts its action by blocking the dopamine D-2 receptors. This study suggests that calcium influx may participate in the MDMA-induced decline in central TPH activity, and that the mechanism by which MDMA and METH decreases TPH activity differs.

3,4-Methylenedioxyamphetamine↗

PubMed1989

Scanning microscopy of the developing vagina in postnatal gerbils.

Scanning electron microscopy of postnatally developing gerbil vagina (birth to maturity) shows that longitudinal folds form prior to transverse folds; the process of fold formation is initiated on the dorsal wall and proceeds ventrally. From days 1 to 7 postnatally, the vaginal epithelium is composed of either flat or bulging cells, depending on the vaginal region. The luminal cell surface is covered with uniform stubby microvilli and solitary cilia. Between days 9 and 20, the flat cells with distinct cell boundaries spread toward more proximal areas, leading to the formation of mixed patches of cells with flat or rounded apices. Individual elongated microvilli or tufts of forked microvilli may sprout from their surfaces. Solitary cilia gradually disappear. The transition from immature to mature vaginal epithelium starts around day 20, when individual cells recess below the level of neighboring cells. This process spreads throughout the vagina during the following days, reflecting local changes in the subsurface layers of the epithelium preparatory to exfoliation. Around day 40 the actual exfoliation of the luminal cell layer starts. By this time the surface characteristics of many of the desquamating cells have changed. In addition to microvilli, microridges are being formed. The process of exfoliation is finished by about day 60. The newly appearing cell layers now transform into typical cornified cells of the cycling vaginal epithelium.

Animals↗