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Biomedical subjects

G Lauer

Publications and source records attributed to G Lauer.

At least 37 records · Page 2Linked to original sources
PubMed2000

Evaluation of microvascular bone graft reconstruction of the head and neck with 3-D 99mTc-DPD SPECT scans.

OBJECTIVE: We conducted a prospective investigation to evaluate the diagnostic accuracy of computer-aided 3-dimensional (3-D) technetium 99m dicarboxypropane methylene diphosphonate ((99m)Tc-DPD) single photon emission computed tomography (SPECT) reconstruction in the evaluation of microvascular bone flaps used for maxillofacial reconstruction. STUDY DESIGN: Twenty patients who received 20 autogenous microvascular bone flaps for reconstruction of the mandible and maxilla were evaluated. Forty bone scans with subsequent computer-aided reconstruction were performed. Each graft could be assessed within 48 to 72 hours after surgery. The second bone scan was performed between 12 and 14 days after surgery. RESULTS: Complications were observed in 5 grafts. SPECT investigation performed at the 2 time points after reconstruction showed a significantly higher tracer uptake in grafts with an uncomplicated further course than in those that developed complications. CONCLUSIONS: Computer-aided 3D (99m)Tc-DPD SPECT reconstruction serves as a useful prognostic tool and helps in the very early recognition of complications. This technique adds significantly to the value of planar bone scintigraphy and conventional SPECT images.

Bone Transplantation↗
PubMed2000

The lateral upper arm free flap for intraoral reconstruction.

Twenty-three consecutive patients who were reconstructed with a lateral upper arm free flap (LUFF) were examined especially concerning functional and morphological results at the recipient and donor sites. There were 22 intraoral and one upper oesophageal reconstruction after radical laryngectomy. The LUFF rendered good functional and esthetic results except for one case of complete and one case of incomplete flap necrosis due to vascular insufficiency of the supplying vessel of the neck. There was some sensory deficit of the donor site (n=10), but no radial nerve injury or conspicuous scarring. Recipient site dehiscence occurred in two cases and a temporary orocervical fistula was seen in one case. Oral function was maintained due to the thin and pliable flap. Excellent flap adaptation to the adjacent tissue was obtained in eight cases of complete loss of lingual attached gingiva in the molar region and in four cases of loss of buccal attached gingiva. The success and functional results of LUFF were comparable to the results of 14 cases in which radial forearm free flaps (RFFF) were used. Although the length of the pedicle and the diameter of the vessels in LUFF are smaller than in RFFF, neither pedicle length nor vessel diameter proved to be a problem. Extent of scarring and risk of vascular compromise proved to be less as compared to RFFF. LUFF is, therefore, the flap of choice for intraoral soft tissue reconstruction and it is advised to reserve RFFF for cases in which LUFF fails.

Adult↗
PubMed1999

Endoscope-assisted fixation of mandibular condylar process fractures.

PURPOSE: Reduction and plate osteosynthesis of condylar fractures often require a wide extraoral approach with the risk of aesthetic impairment and possible facial nerve palsy. To avoid complications, the purpose of this pilot study was to use an endoscopic device for the treatment of condylar fractures also allowing for endoscopically assisted plate application. PATIENTS AND METHODS: Seven condylar fractures were operated under endoscopic control. In three patients, a newly developed device for endoscopically controlled plate application was clinically tested. The new device and the application technique is described in detail. RESULTS: In two of three cases using this approach, fracture healing was achieved with the condyle in the anatomically correct position. In the third case the plate had to be removed early because of insufficient screw fixation. CONCLUSION: This technique may be helpful to further minimize surgical trauma in head and neck fracture treatment. The newly developed plate application device may also be used to approach other regions of the skull eg, the skull base, the zygoma, or the orbit.

Bone Plates↗
PubMed1999

Oral or intravenous iron as an adjuvant to autologous blood donation in elective surgery: a randomized, controlled study.

BACKGROUND: This study was performed to evaluate the capacity of oral and intravenous (i.v.) iron administration during autologous blood donation (ABD) to improve the efficacy of ABD and to prevent the need for allogeneic blood transfusion in patients without iron deficiency who are undergoing major elective surgery for which a minimum of 3 autologous units have been ordered. STUDY DESIGN AND METHODS: One hundred twenty-three patients were enrolled in an open-labeled, randomized, controlled trial and assigned to three treatment groups: patients in Group 1 received 3 x 100 mg of Fe2+ per day given orally for 5 weeks before operation; patients in Group 2 received 200 mg of Fe3+ given intravenously after each donation combined with initial i.v. iron supplementation in patients with hemoglobin under 15 g per dL; and patients in Group 3 were in the control group that received no iron medication. A modest ABD program involving weekly phlebotomy and threshold hemoglobin values for donation of 11.5 g per dL in women and 12.0 g per dL in men was performed. RESULTS: Ninety patients, 15 women and 15 men in each of the three groups, completed the study. The mean net red cell production during ABD was no higher (p>0.2) in the iron-treated groups (Group 1: 473 +/- 178 mL; Group 2: 436 +/- 170 mL; Group 3 (controls): 397 +/- 174 mL). The mean number of autologous units donated per patient did not differ (p>0.7) among the groups (Group 1: 3.1 +/- 0.6; Group 2: 2.9 +/- 0.7; Group 3: 3.0 +/- 0.7). The proportion of patients who needed allogeneic blood transfusion showed no significant (p>0.4) advantage for iron treatment, (Group 1: 7%; Group 2: 20%; Group 3: 10%). CONCLUSION: In non-iron-deficient patients undergoing modest ABD without erythropoietin therapy, neither oral nor i.v. application of iron during the preoperative period enhances the success of preoperative ABD.

Administration, Oral↗
PubMed1998

[Endoscope-assisted fixation of condylar fractures of the mandible].

The reduction and plate osteosynthesis of condylar fractures often require a wide extraoral approach with the risk of facial nerve palsy. The endoscopic technique is an alternative. Seven condylar fractures were operated on under endoscopic control. In three patients a newly developed device for endoscopically controlled plate application was clinically tested for osteosynthesis. In two cases fracture healing was achieved. In the third case the plate had to be removed early due to insufficient screw fixation. The new device and the application technique are described in detail. This technique may be helpful in further minimizing trauma surgery.

Bone Plates↗
PubMed1997

Peripheral administration of cholecystokinin activates c-fos expression in the locus coeruleus/subcoeruleus nucleus, dorsal vagal complex and paraventricular nucleus via capsaicin-sensitive vagal afferents and CCK-A receptors in the rat.

Intraperitoneal (i.p.) administration of sulfated CCK octapeptide (CCK-8S) has been shown to induce changes in neuronal activity in the nucleus of the solitary tract (NTS) and area postrema (AP), sensory parts of the dorsal vagal complex (DVC), and in the paraventricular nucleus of the hypothalamus (PVN), as determined by activation of c-fos expression. Whether peripheral CCK influences neuronal activity in the locus coeruleus (LC)/subcoeruleus nucleus (SC) was investigated in awake rats at intraperitoneal (i.p.) injection of CCK-8S by c-Fos immunohistochemistry. CCK-8S i.p. (25, 50, and 100 micrograms/kg, respectively) dose-dependently increased the average number of c-Fos-LI-positive cells/section in the LC/SC by the factor 5.9, 8.2, and 11.7, respectively. Pretreatment with the CCK-A receptor antagonist MK-329 (devazepide; 1 mg/kg and 2 mg/kg i.p.) reduced the CCK-induced increase in c-fos expression in the LC/SC by 54% and 75%, respectively; the CCK-B receptor antagonist L-365,260 had no effect. Perivagal capsaicin pretreatment diminished the CCK-induced increase in the number of c-Fos-LI-positive cells in the LC/SC by 65%. In comparison, the CCK-A antagonist devazepide (1 mg/kg and 2 mg/kg i.p.) reduced the increase in c-fos expression by 76% and 88% in the PVN, 69% and 88% in the NTS, 86% and 83%, respectively, in the AP. Capsaicin diminished the CCK-induced increase in c-Fos-LI-positive cells in the PVN by 64%, in the NTS by 60%, but in the AP only by 25%. Immunostaining against the nuclear antigen c-Fos and the cytoplasmatic antigen tyrosine hydroxylase (TH) showed that 40% of all c-Fos-LI-positive cells in the LC/SC were TH-LI positive at 25 micrograms CCK/kg. The data indicate that CCK-8S i.p. induces modulation of neuronal activity in the LC/SC, DVC and PVN predominantly by peripheral action of CCK-A receptors and capsaicin-sensitive vagal afferents. These findings suggest that the LC/SC is involved in CNS-mediated regulatory influences of peripheral CCK.

Animals↗
PubMed1997

[Modifications in cultivating gingival keratinocytes].

Gingival keratinocyte grafts are usually cultured using 3T3 mouse fibroblasts as feeder cells and fetal calf serum as growth factor. These additives entail risks due to xenogenic DNA and protein. Therefore the explant and the disperse culture technique free of feeder cells were compared, and autogenous human serum was tested. Twelve halved gingival biopsies were trypsinized and cultured as single-cell suspensions, the other halves were cultured as explants. Six halved biopsies were cultured in autogenous serum, the other halves in fetal calf serum. Growth, morphology and cell biological aspects were compared. The single-cell suspensions did not form a confluent epithelial layer, whereas all explants formed confluent primary gingival keratinocyte cultures. The keratinocytes' growth in autogenous serum was equivalent to that in fetal calf serum. Morphology and cytokeratin expression were identical. The explant technique combined with autogenous serum can be used for culturing gingival autografts as well as for individual cultures for special issues.

Animals↗
PubMed1997

[Cultivation of gingival keratinocytes on permeable membranes: simulation of the function of mouth cavity epithelium].

Cultured epithelial cells are used in in vitro studies. Gingival keratinocytes are usually grown adherent to the floor of the culture dish, whereby the basal side of the epithelium can not be approached. To be able to study barrier function and transepithelial transport processes the gingival keratinocytes were seeded on different permeable membranes as support material. Six primary keratinocyte cultures each using the explant technique were established on polycarbonate membranes with pore sizes 2-8 mm and on nylon. Secondary cultures were established accordingly as single-cell suspension. Primary cultures formed confluent epithelial cultures on all membranes tested, whereas in secondary culture confluent gingival keratinocyte epithelia were found on the polycarbonate membranes, only. Thus, gingival keratinocytes can be used to study barrier and transport functions in an in-vitro model.

Biological Transport↗
PubMed1997

Serum interleukin 4 and interleukin 10 levels in patients with chronic hepatitis C virus infection.

BACKGROUND/AIMS: Immune-mediated mechanisms are believed to play an important pathogenetic role in chronic hepatitis C virus infection. Interleukin 4 (IL-4) and IL-10 are secreted by T helper-2 type cells (Th2) which may downregulate cell-mediated immune effector mechanisms important in the host defense against intracellular pathogens. This study aimed to determine Th2 cytokine levels in chronic hepatitis C virus infection. METHODS: Serum IL-4 and IL-10 levels were measured in 74 patients with chronic hepatitis C virus infection and 20 healthy controls. The expression of CD30 in liver, a marker that is preferentially expressed in Th2 cells, was also determined by immunohistochemical staining in 37 patients. RESULTS: Serum IL-4 and IL-10 were below the detection limit (5 pg/ml) in all 20 healthy controls. However, 36 patients (49%) had elevated serum IL-4 levels (range 5-106 pg/ml, p<0.001) and 23 patients (31%) had elevated serum IL-10 levels (range 5-37 pg/ml, p<0.05). There was no correlation between serum IL-4 and IL-10 levels. There was also no correlation between serum IL-4 and IL-10 levels and any of the clinical (age, gender, mode of acquisition), biochemical (serum alanine transaminase levels), virologic (viremia level, genotype), and histological parameters examined. Twenty of 37 liver biopsy specimens from patients with chronic hepatitis C virus infection showed occasional CD30+ lymphocytes, suggestive of Th2 phenotype. However, in 20 of the 37 patients with paired cryostat liver sections, IL-4 was not detected in any of these patients, suggesting that IL-4 was not produced in the liver in patients with chronic hepatitis C virus infection. CONCLUSIONS: This study showed that serum Th2 cytokines are elevated (but at a low level) in a proportion of patients with chronic hepatitis C virus infection. However, the elevated Th2 cytokine levels may represent a systemic response and not a result of increased local production within the liver.

Adult↗
PubMed1997

Pathways of Fos expression in locus ceruleus, dorsal vagal complex, and PVN in response to intestinal lipid.

Exogenous cholecystokinin (CCK) injected peripherally mimics effects of lipid entering the intestine on food intake and gastric motility via vagal afferents and induces c-fos expression in the locus ceruleus complex (LCC), nucleus of the solitary tract (NTS), area postrema (AP), and paraventricular nucleus (PVN). However, the role of peripheral endogenous CCK in induction of c-fos expression in the brain at ingestion of nutrients is controversial. In awake rats, intraduodenal lipid infusion markedly increased Fos protein-like immunoreactivity (FLI) in these brain nuclei. Perivagal capsaicin pretreatment reduced the increase of FLI in the LCC, NTS, and PVN by 66-86% and in the AP by 46%. The CCK-A receptor antagonist MK-329 (0.1 mg/kg i.p.) diminished the FLI increase in LC, NTS, AP, and PVN by 39-100%; the CCK-B receptor antagonist L-365,260 reduced the increased FLI in the AP by 54%. After capsaicin pretreatment, both CCK antagonists had additional inhibitory effects only on FLI in the AP. These findings suggest that entry of lipid into the intestine activates c-fos in the LCC, NTS, and PVN predominantly via CCK-A receptors on vagal afferents and in the AP via vagal and nonvagal pathways, as well as CCK-B and CCK-A receptors.

Animals↗
PubMed1996

Microinfusion of corticotropin-releasing factor into the locus coeruleus/subcoeruleus nuclei inhibits gastric acid secretion via spinal pathways in the rat.

Brain corticotropin-releasing factor (CRF) is involved in stress-related alterations of gastric acid secretion. CRF in the locus coeruleus has been shown to induce anxiogenic behavioral responses and to mimic stress-induced alterations of colonic motor function. Whether the locus coeruleus/subcoeruleus nucleus (LC/SC) is a site of action for CRF to alter gastric acid secretion was investigated in urethane-anesthetized gastric fistula rats. In sham-operated animals, CRF (126-420 pmol) microinfused bilaterally into the LC/SC induced a dose-dependent inhibition of pentagastrin (PG)-stimulated gastric acid secretion of 60-81% within the first hour after microinjection. At the 420 pmol dose, this inhibitory effect of CRF into the LC/SC lasted throughout the whole observation period of 120 min. After bilateral vagotomy, basal and PG-stimulated gastric acid secretion at microinjection of vehicle was reduced. Nevertheless, microinfusion of 420 pmol CRF into the LC/SC still inhibited significantly gastric acid secretion by 62.1%. In contrast, in spinal cord transected animals bilateral microinfusion of 420 pmol CRF into the LC/SC did not reduce PG-stimulated gastric acid secretion. These data indicate that CRF acts in the LC/SC to induce a long lasting inhibition of peripherally stimulated gastric acid secretion via spinal pathways. These findings suggest a possible role of the LC/SC in the regulation of gastric secretion and of endogenous CRF at these sites in the stress-related inhibition of gastric acid secretion by affecting autonomic nervous system activity.

Animals↗
PubMed1996

Transalveolar fixation of the peri-implant soft tissue in the mandible: surgical method and clinical follow-up.

PURPOSE: Firm, immobile mucosa around endosteal implants is one prerequisite for a reliable long-term result. In the atrophic mandible, this may be achieved by a vestibuloplasty on the facial side. However, on the lingual side, the floor of the mouth is often high and the mucosa mobile, especially after unintentional detachment of the lingual flap during implant surgery. To overcome this problem, a surgical technique applying a transalveolar suture circumscribing the inserted implants was developed. PATIENTS AND METHODS: The operation was performed in six patients, and they were evaluated over a period of more than 18 months. RESULTS: There was a clinically significant increase in fixed mucosa behind the implants compared with a control group of six patients with a similar preoperative and intraoperative status. CONCLUSION: A localized lowering of the floor of the mouth limited to the peri-implant region using this technique can successfully improve the lingual mucosa around implants.

Aged↗
PubMed1996

Neutral glycolipids of Schistosoma mansoni as feasible antigens in the detection of schistosomiasis.

The neutral glycolipid fraction from mouse-propagated, Schistosoma mansoni adult worms has been investigated as to its chromatographic and antigenic properties, and whether it fulfills the serodiagnostic antigen requirements of sensitivity and specificity in the detection of schistosomiasis. Serological analyses were performed by thin-layer chromatography immunostaining and ELISA. In the acute-phase form of mouse schistosomiasis, the kinetics of development of neutral glycolipid-specific antibody levels was correlated with the intensity of the initial infection and the response was dominated by IgG, as represented by the subclass IgG1. With the experimental animal helminthiases screened, glycolipid antigenicity fulfilled the fundamental traits for a serodiagnostic reagent. In the chronic-phase form of human schistosomiasis mansoni, neutral glycolipid-specific antibody levels were not correlated with the intensity of infection, as estimated from the faecal content of parasite eggs, whilst the isotypic response was dominated by IgM and IgG, the latter represented primarily by IgG1 and secondarily by IgG3. With other human helminthiases, glycolipid antigenicity was incomplete, in that, the specificity was only partially fulfilled. The reason for this incomplete specificity has been clarified, in part, by the detection of cryptic schistosomiasis infections in the cohorts of African patient sera examined.

Animals↗
PubMed1996

[Factitious disorders: psychopathologic markers, biographic background and therapy follow-up].

Based on german authors literature this contribution describes important features of facticious disorders. By demonstrating a single case, succeeding in a biographical reconstruction of the unconscious simulation of complaints, recent assumptions on this group of patients are discussed. Thereupon hints are seen voting against the common assumption of poor therapeutic prognosis.

Adult↗
PubMed1995

[Relapse in alcoholism during inpatient therapy. Empirical facts and practical recommendations for relapse management].

The contribution resumes the most important empirical results on the phenomenon of alcoholic relapse during inpatient-treatment. Results and clinical considerations lead to the opinion to abandon the classic position of disciplinary discharge after inpatient relapse without deviating from the ideal target of abstinence. Proposals are made for the practical management of relapses during inpatient-treatment. Finally, it is demanded for empirical studies on this taboo field of addiction treatment for deciding the questions of continued treatment or discharge after inpatient alcoholic relapse.

Alcoholism↗
PubMed1994

Autografting of feeder-cell free cultured gingival epithelium. Method and clinical application.

In oral and maxillofacial surgery an adequate mucosa/gingiva transplant is often not available in the amount required. Use of cultured gingival keratinocytes is a possibility in overcoming this problem. Keratinocytes were cultured in primary culture from gingival biopsies without xenogenous feeder-cells. The cells grew out of explants and formed, within 4 to 6 weeks, a sheet of keratinocytes up to size of 75 cm2. We have a success rate of 65% in cultures of people older than 40 years. This and the culture without feeder-cells encouraged us to use the cultured gingival cells as an autologous transplant in pre-prosthetic surgery for anterior vestibuloplasty.

Adolescent↗
PubMed1994

[Domain-specific subjective quality of life and illness-related limitations of chronic schizophrenic patients].

The relationships of subjective quality of life in nine domains and negative symptoms, duration of illness, dosage of a neuroleptic and neuroleptic side-effects are investigated in 30 chronic schizophrenic patients. Negative symptoms show negative correlations with four domains (safety, social relations, health, leisure), duration of illness with three domains (health, leisure, living situation). Whereas the dosage of a neuroleptic relates to safety only, neuroleptic side-effects correlate with five domains (social relations, health, safety, living situation, work and employment). The results are discussed in the light of clinical experience and former empirical studies. Proposals for further research are presented.

Activities of Daily Living↗