Biomedical subjects

Peter Kessler

Publications and source records attributed to Peter Kessler.

23 records · Page 2Linked to original sources

PubMed2003

[Distraction osteogenesis in the midface. Indications, technique and first long-term results].

Since the beginning of 1998, eleven patients have been treated by osteodistraction to correct hypoplasia of the maxilla and midface of various origins. Among them were six patients who were treated by high LeFort I osteotomies and insertion of subcutaneous intraoral distraction devices in the malar region. In the remaining five patients extraoral distraction devices were applied after LeFort I, II and III osteotomies. Distraction osteogenesis was successful in all cases, resulting in a mean sagittal bone gain measured parallel to the skull base of 9.5 mm (range 4.5-12.0) in the group treated with intraoral distractors and a mean of 19.4 mm in the extraoral distraction group (range 15.0-25.0). All patients were kept under orthodontic supervision before, during, and after osteodistraction. In eight patients long-term cephalometric and clinical evaluation after a mean follow-up period of 24 months in the intraoral distraction group (range 22-26) and 12 months in the extraoral distraction group (range 10-14) show stable results concerning the skeletal and dental relations. Long-term follow-up is necessary.

Adolescent↗

PubMed2002

Glucose is toxic to glycosome-deficient trypanosomes.

Trypanosomatids, the etiologic agents of sleeping sickness, leishmaniasis, and Chagas' disease, compartmentalize glycolysis within glycosomes, metabolic organelles related to peroxisomes. Here, we identify a trypanosome homologue of PEX14, one of the components of the peroxisomal protein import docking complex. We have used double-stranded RNA interference to target the PEX14 transcript for degradation. Glycosomal matrix protein import was compromised, and both glycolytic bloodstream stage parasites and mitochondrially respiring procyclic stage parasites were killed. Thus, unlike peroxisomes, glycosomes are essential organelles. Surprisingly, procyclic forms, which can grow in the absence of glucose, were killed by PEX14 RNA interference only when simple sugars were present. Thus, interference with glycosome protein import makes glucose toxic to trypanosomes.

Amino Acid Sequence↗

PubMed2002

Endoscopically assisted Le Fort I osteotomy to correct transverse and sagittal discrepancies of the maxilla.

PURPOSE: The purpose of this report was to show the feasibility of the combination of a minimally invasive endoscopic approach to the maxilla with transverse and sagittal distraction procedures. MATERIALS AND METHODS: Four human cadavers were used for training of a minimally invasive access to the maxilla to perform a endoscopically assisted Le Fort I osteotomy, before this technique was applied in 3 patients with transverse and sagittal growth deficits of the maxilla. Access to the maxilla was gained through a small mucosa incision in the vestibule to create a visualization port to the maxillary sinus through a bur hole. Landmarks were identified through the endoscope before a Le Fort I osteotomy was performed using chisels of different shapes and angulations. In 2 patients the maxilla was split sagittally to perform a transverse maxillary expansion; in 1 patient, a buried distractor was applied close to the piriform aperture to correct a sagittal growth deficit in a hypoplastic maxilla. RESULTS: Endoscopic exposure of the maxillary sinus walls from within the sinus, the accurate identification of landmarks, and the creation of a Le Fort I osteotomy were achieved in all cases. Distractor application close to the piriform aperture rendered good stability. CONCLUSION: The results of these cases indicate that the endoscopic approach to the maxillary sinus allows excellent exposure of the sinus walls to perform a endscopically assisted Le Fort I osteotomy. The combination of endoscopy and osteodistraction processes supports the tendency to perform minimally invasive, less-traumatizing surgical procedures, especially in individuals who are still growing.

Adolescent↗

PubMed2002

Remifentanil vs morphine for patients in intensive care unit who need short-term mechanical ventilation.

This randomized, double-blind study compared the safety and efficacy of remifentanil (9 microg/ kg/h) with morphine (0.045 mg/kg/h plus a bolus dose of 0.025 mg/kg). One hundred and eighty nine Intensive Care Unit (ICU) patients with normal renal function or mild renal impairment requiring mechanical ventilation were included in this study. A pre-defined dosing algorithm permitted initial titration of the opioids to predetermine the optimal level of sedation and pain score. Supplementary infusion of midazolam (0.03 mg/kg/h) was given when additional sedation was required. The duration of optimal sedation during the maintenance phase was 82.7 per cent and 84.3 per cent of the total time in the remifentanil and morphine groups respectively. There were no statistically significant differences in the between-subject variability in the duration of optimal sedation between the two treatment groups. Midazolam was not required in approximately 75 per cent of all patients. The patients in the morphine group required twice the amount of midazolam required by the remifentanil group. The dosing algorithm facilitated rapid extubation in both groups. Remifentanil provided comparable hemodynamic stability to morphine, and was not associated with an increase in cardiovascular adverse event. Remifentanil is therefore considered to be effective and well tolerated in ICU patients.

Adult↗

PubMedDate not supplied

Bone conditioning to enhance implant osseointegration: an experimental study in pigs.

PURPOSE: Osseointegration of implants depends on time and the local bone conditions regarding quality and quantity. This led to the bone classification by Lekholm and Zarb. The aim of the present study was to enhance osseointegration of implants through conditioning of the bone bed and to compare in this context the efficacy of bone condensation, an osteoinductive collagen (Colloss), and platelet-rich plasma (PRP). MATERIALS AND METHODS: Porcine frontal skull bone was used for the preparation of Identical-size implant beds. Before placement of the implants (Ankylos, 3.5 x 4 mm), the implant beds were untreated (control) or conditioned with condensation, Colloss, or PRP. The animals were sacrificed after 2, 4, and 8 weeks. The specimens were then compared and analyzed by microradiography, and statistical analysis was performed using the Wilcoxon signed rank test. RESULTS: At the early observation times, significant effects on the sites of topical bone conditioning in comparison to the control group could be seen regarding the implant-bone interface (2 weeks: control 31%, Colloss 60%, condensation 73%, PRP 47%; 4 weeks: control 39%, Colloss 51%, condensation 40%, PRP 42%) and peri-implant bone density (2 weeks: control 31%, Colloss 48%, condensation 59%, PRP 39%; 4 weeks: control 47%, Colloss 53%, condensation 41%, PRP 50%). A leveling of the results between groups was found at 8 weeks (implant-bone interface: control 51%, Colloss 58%, condensation 55%, PRP 62%; peri-implant bone density: control 50%, Colloss 55%, condensation 51%, PRP 51%). DISCUSSION: Overall, bone condensation and Colloss apparently influenced bone formation process from the onset, but over the entire 8-week healing period, differences in bone formation were not significant CONCLUSION: It can be stated that, in the initial healing phase, an effect of topical bone conditioning may be achieved by the different described methods.

Animals↗