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Biomedical subjects

C Lindqvist

Publications and source records attributed to C Lindqvist.

At least 109 records · Page 6Linked to original sources
PubMed1993

Pharmacokinetics and effects of mannitol on hemodynamics, blood and cerebrospinal fluid electrolytes, and osmolality during intracranial surgery.

Fifteen patients who underwent surgery for intracranial tumors under general anesthesia were given mannitol (1 g/kg of body weight) over 30 min. Measurements of mannitol concentration, osmolality, and electrolytes were determined in blood and cerebrospinal fluid (CSF) samples collected over an 8-h period. Seven sets of hemodynamic observations and four sets of intracranial pressure (ICP) measurements were also made. Mannitol disappeared from plasma in a biexponential manner. The mean maximal plasma concentration was 5.91 mg/ml at the end of mannitol infusion and decreased to 0.58 mg/ml after 8 h. The plasma half-life for the distribution phase was 0.16 h and for the elimination phase was 2.44 h. The distribution volume was 17.0 L and total plasma clearance 87.4 ml/min. There were marked interindividual variations of mannitol concentration in the CSF. The mean CSF concentration at 8 h was 97.1 micrograms/ml, started to decline earlier in 10 of 12 patients, and never exceeded 12% of that in plasma. Osmolality in serum increased with a maximum at the end of mannitol infusion (from 292 +/- 7 mOsmol/kg to 310 +/- 14 mOsmol/kg; p < 0.01), whereas CSF osmolality was unchanged, thus giving rise to a positive blood-CSF osmotic gradient of at least 10 mOsmol/kg for about 30 min. At the end of the mannitol infusion, cardiac output and pulmonary capillary wedge pressure increased significantly, whereas the hematocrit decreased. ICP was observed in five patients for 45 min, and mannitol induced a mean reduction from 11 +/- 4 to 4 +/- 2 mm Hg (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Expression of human IL-2 receptor alpha- and beta-chains using the baculovirus expression system.

The genes encoding the alpha- and beta-chains of the human interleukin-2 receptor were expressed in lepidopteran insect cells using the baculovirus expression vector system. The corresponding genes were inserted under the polyhedrin promoter of the Autographa california nuclear polyhedrosis virus and expressed in the Spodoptera frugiperda insect cell line during viral infection. The recombinant receptor proteins were identified in the insect cell lysates by using protein dot blot and ELISA techniques. At 36 h post infection the corresponding proteins were clearly detected using anti-IL-2 alpha- and beta-receptor-specific antibodies. A large amount of the alpha-chain was also found in the supernatant culture media at 72 h post infection and metabolic labelling with [35S]-methionine indicated that it was proteolytically cleaved into a 32 kDa soluble form. A similar soluble or secreted form of the beta-chain was, however, not observed. Both receptor proteins were expressed on the surface of the insect cells as determined by flow cytometry analysis. Studies performed with the different IL-2 receptor forms (alpha- and beta-chains alone or in combination) in the presence or absence of rIL-2 suggest that the receptor proteins when expressed in infected insect cells are non-functional with respect to tyrosine phosphorylation.

Animals↗
PubMed1993

One-year trial of the effect of rinsing with an amine fluoride-stannous-fluoride-containing mouthwash on gingival index scores and salivary microbial counts in lymphoma patients receiving cytostatic drugs.

This double-blind study was undertaken to evaluate the effect of twice-daily use of a mouthwash containing 0.025% of fluoride as amine fluoride-stannous fluoride (AmF + SnF) or 0.05% of fluoride as sodium fluoride (NaF) on visible plaque index (VPI) and gingival bleeding index (GBI) and on some salivary micro-organisms in patients suffering from non-Hodgkin or Hodgkin lymphomas. 79 patients were allocated at random to the two mouthwash groups. Mouthwashing began at the start of cancer chemotherapy. Results relating to 45 patients who completed a 1-year rinsing protocol showed a significant decrease in VPI and GBI in the AmF + SnF group. An increase was found in the NaF group. Mean values for stimulated salivary secretion rates and buffering capacities mostly did not differ significantly from baseline values during the study. In both groups, mutans streptococci counts decreased significantly after the study began and remained low in the AmF + SnF group. No corresponding effect was seen in relation to lactobacilli and yeast counts. In the NaF group, lactobacilli counts increased significantly over a year. Significantly more patients reported adverse or unpleasant effects in the AmF + SnF group (52%) than in the NaF group (6%), although both solutions had the same colour and taste. However, all patients continued with rinsing.

Adult↗
PubMed1993

Dental injuries in association with mandibular condyle fractures.

A total of 356 patients with mandibular condyle fractures were studied regarding associated dental injuries. One third of the patients had injured teeth, on average, 3.7 teeth had been injured per accident. Dental traumas were distributed equally between the anterior (incisors and canines) and posterior teeth (premolars and molars) in both jaws. In unilateral condylar fracture cases maxillary dental injuries involved more often premolars and/or molars of the fracture side than those of the nonfracture side. The mean number of dental traumas in the mandible was higher in cases of simultaneous mandibular body fracture than without, whereas the presence of mandibular body fracture did not affect number of associated dental injuries in the maxilla. The dental injuries were mostly to hard tissue (78%), which were commonest in men, 20 to 29 years of age, and in victims of violence or fall accidents. Severe dental injuries in association with mandibular condyle fractures were more common in accidents due to traffic and miscellaneous causes than in those due to violence. Severe dental injuries were more often encountered when simultaneous mandibular body fracture was present than when it was not and more so in bilateral than unilateral condylar fracture cases. The most important factor correlating with the severity of dental injuries was the presence of bilateral condylar fracture.

Accidental Falls↗
PubMed1993

Rigid internal fixation of fractures in the angular region of the mandible: an analysis of factors contributing to different complications.

Data relating to 113 patients with 121 mandibular angle fractures treated according to the principles of rigid internal fixation were analyzed to determine which clinical factors are associated with different complications. Certain clinical characteristics were found to be associated with major complications. The use of compression plates seemed to entail disadvantages resulting in some complications. Because of the relatively small cross section of bone surface and particular anatomic features of the angular region, well-adjusted interfragmentary compression is often not possible. A neutral reconstruction plate is considered optimal for rigid osteosynthesis. If a molar tooth in the fracture line has to be extracted, this should be done after fracture stabilization. In most cases, an extraoral approach could not be avoided, but complications associated with this approach were infrequent and well tolerated by patients.

Adult↗
PubMed1993

A baculovirus-expressed fusion protein containing the antibody-binding domain of protein A and insect luciferase.

A fusion construct encoding two antibody-binding sites of protein A from Staphylococcus aureus and click beetle, Pyrophorus plagiophthalamus, luciferase (LucGR) was designed and expressed using the baculovirus system. The construct was inserted under the transcriptional regulation of the polyhedrin gene promoter of the Autographa californica nuclear polyhedrosis virus (AcNPV) and expressed in the insect Spodoperta frugiperda cell line during viral infection. The properties of the resultant chimeric protein product, protA-LucGR, were studied both in vivo and in vitro by using i) luminometry, ii) immunoblot analysis, iii) immunoprecipitation, iv) metabolic labeling procedures and v) luminescent immunoassays. Together, the results clearly demonstrate that the light-emitting properties of the fused luciferase construct remain intact. Further, the antibody-binding domain of protein A retains its activity as it binds to both rabbit and goat as well as human immunoglobulins. Due to the dual biological function of this fusion protein, it should provide a potential reagent within the field of molecular biology and diagnostics.

Animals↗
PubMed1992

Decreased interleukin-2 beta-chain receptor expression by interleukin-4 on LGL: influence on the IL-2 induced cytotoxicity and proliferation.

Addition of increasing amounts of interleukin-4 (IL-4) to large granular lymphocytes (LGL) had a selective downregulative effect on the interleukin-2 beta-chain (p70) receptor expression. A 40% inhibition of the p70 expression compared to untreated cells was already observed after a 24-h incubation with IL-4. This decrease in p70 receptor expression had a marked suppressive effect on their proliferative response to IL-2. In addition, LGL cultured in the presence of both IL-2 and IL-4 substantially decreased the cytotoxic activity against the erythroleukemia cell line K562. Our data therefore indicate an important regulative role for IL-4 on the LAK-generation.

Cell Division↗
PubMed1992

Is nasotracheal intubation safe in surgery for mandibular cancer?

A retrospective study of problems of postoperative airway maintenance after surgery for mandibular cancers was conducted. Twenty-seven patients treated in an intensive care unit after mandibular resection and primary reconstruction were included. The mean duration of nasotracheal intubation in 22 patients was 33.7 hours. Reintubation because of breathing difficulties was required in four cases. In one of these cases, failed intubation led to an emergency cricothyroidostomy. Failure to perform reintubation resulted in the death of one patient. One patient was tracheostomized after 5 days of nasotracheal intubation. Prolonged nasotracheal intubation after major surgery for oral malignant neoplasms may be an alternative to tracheostomy, provided that adequate monitoring is available after extubation. The safe duration of endotracheal intubation is difficult to determine. Primary reconstruction does not eliminate the need for an artificial airway after tumor surgery.

Adult↗
PubMed1992

Radiologic follow-up of bone transplants to bridge mandibular continuity defects.

Special radiologic imaging techniques were used to evaluate the results of nonvascularized bone grafts combined with rigid mandibular reconstruction plates. The radiologic findings divided 21 cases into three clearly distinct groups on the basis of resorption: slight (less than 15%), moderate (15% to 30%), and massive (more than 30%) (mean follow-up, 26 months). This division predicted the clinical results well. In contrast to earlier reports, it was shown that rigid plate bridging did not adversely influence the prognosis of the graft. Nor was early plate removal necessary to reach good ossification. Narrow-beam radiography and spiral tomography proved to be excellent tools for adequate evaluation of bone resorption and bony healing of mandibular grafts.

Adult↗
PubMed1992

The histologic pattern of bone invasion by squamous cell carcinoma of the mandibular region.

Surgical specimens from 16 nonirradiated patients with carcinoma of the mandibular region who had undergone resection of the mandible were investigated histologically to evaluate the presence, pattern and extent of bone involvement. Thirteen of the 16 carcinomas had invaded the mandibular bone. Two main patterns of growth were identified: seven carcinomas had infiltrated nonuniformly into the bone and six tumours had advanced as a compact front. Direct invasion from the oral mucosal tumour could be verified in 12 cases. Extension of four of these 12 tumours in bone clearly exceeded their dimension in the overlying mucosa. Carcinoma tissue in the mandibular canal, at a distance from the major tumour extension, was seen in two cases, whereas the periodontal ligament spaces were invaded only when there was a direct contiguous invasion by the tumour. The grade of histologic differentiation of the carcinoma did not definitely correlate with the frequency, pattern or extension of bone involvement. The results indicate that large tumour size, location on the mandibular alveolar ridge and clinical fixation to the mandibular bone predispose to, but are not prerequisites for bone invasion. Taken together, this study has shown that prediction of the presence and extent of bone involvement of the carcinoma located in the mandibular region is difficult on clinical grounds.

Adult↗
PubMed1992

Topical application of 5% eutectic mixture of lignocaine and prilocaine (EMLA) before removal of arch bars.

The analgesic effect of topical application of a 5% eutectic mixture of lignocaine and prilocaine (EMLA) was studied in 45 patients undergoing removal of oral arch bars used for the treatment of mandibular fractures. Employing a double-blind technique, either 4 g of the eutectic mixture (EMLA group, n = 15) or 4 g of a similar emulsion containing no local anaesthetic (placebo group, n = 15) was applied to the gingivae using a toothbrush and a standardised technique. In the control group (n = 15), infiltration anaesthesia with lignocaine was used only if requested by the patient during the removal of the arch bars. The patients in the EMLA group had significantly better analgesia (P less than 0.005) of the gingivae just before removal of the arch bars than patients in the placebo group, but by the end of the procedure the difference in analgesia was not significant. The number of patients who found the procedure pain-free was significantly higher in the EMLA group (7/14) than in the placebo group (2/15) (P less than 0.005). The plasma concentrations of both lignocaine and prilocaine were well below the toxic levels. Topical application of EMLA can be recommended for short procedures as an alternative to infiltration.

Administration, Oral↗
PubMed1992

Erosion and heterotopic bone formation after alloplastic temporomandibular joint reconstruction.

Twenty-three temporomandibular joint arthroplasties using metallic condylar prostheses were performed because of severe ankylosis (8 patients), segmental mandibular resections in tumor surgery (9 patients), and after extensive trauma (2 patients). A clinical and radiological follow-up study showed heterotopic bone formation in 52% of cases and glenoid fossa resorption in 43%. In one patient with rheumatoid arthritis the condyle eroded through the skull base 10 months after surgery. Seven prostheses (30%) were removed and/or exchanged during the average 27.6-month follow-up.

Adult↗
PubMed1992

Rigid reconstruction plates for immediate reconstruction following mandibular resection for malignant tumors.

Thirty-four primary alloplastic reconstructions of segmental mandibular defects caused by surgery for oral malignancy were performed during a 6-year period. Eighty-eight percent of the tumors were classified as stage III or IV. One third of the patients died during follow-up, nine with their primary reconstruction plate in place. During the follow-up, 12 patients required plate removal because of complications; four of them were treated with another plate. Nineteen of 21 patients alive at the end of follow-up were free of disease. Ten had their primary plate in place, and four had had a secondary plate installed because of plate fracture or screw loosening. Three patients had their mandible permanently reconstructed with bone. The functional and esthetic results were considered excellent or fair in a majority of the cases. Because the 5-year survival rate for patients with advanced mandibular malignancies is 15% to 20%, extensive, definitive reconstructive procedures during primary surgery are usually not justified.

Adult↗
PubMed1992

Cross-sectional tomography in evaluation of patients undergoing sagittal split osteotomy.

A study was performed to evaluate the possibility of locating the mandibular canal before sagittal split osteotomy by cross-sectional spiral tomography in 55 patients. Visibility of the whole canal wall circumference was excellent or good in 65.5% fair in 18.2%, and poor in 12.7% of cases. Only four canals (3.6%) were invisible. The canal was located lingually in 61 cases, buccally in 9 cases, and centrally in 34 cases. In patients with mandibular protrusion, the mean (+/- SD) buccolingual width was significantly smaller (9.5 +/- 1.51 mm vs 10.4 +/- 1.46 mm, P < .01) and the mandibular canal was more often buccally located than in patients with retrognathia.

Adolescent↗
PubMed1992

Different patterns of condylar fractures: an analysis of 382 patients in a 3-year period.

Three hundred eighty-two patients with 443 condylar fractures, accounting for 52.4% of all mandibular fractures, were given diagnoses and treated in our department between 1987 and 1989. A high proportion of the fractures (44%) were caused by interpersonal violence, followed in incidence by falls (29%) and road traffic accidents (21%). The type of condylar fracture seems to be influenced directly by its cause. Severe fractures in which the condyle was dislocated out of the glenoid fossa resulted more often from falls (22%) and road traffic accidents (26%) than from violence (8%). Fractures caused by violence showed a uniform type characterized by a subcondylar location and nondisplacement or deviation at the fracture line. A relatively large number of patients (56, 15%) were considered to have an indication for open reduction of the fracture.

Accidental Falls↗
PubMed1992

Salivary flow and composition in lymphoma patients before, during and after treatment with cytostatic drugs.

To investigate the effect of modern, intensive chemotherapy on salivary flow rate and composition, 79 patients suffering from Hodgkin's disease or non-Hodgkin lymphoma were studied before, during and after administration of cytostatic drugs. 49 patients (mean age 49.9 years, 30 men, 19 women) completed the 1-year study. All patients who received radiotherapy or medication other than cytostatics were excluded. The results showed no marked differences in stimulated salivary flow rates, buffering capacities and amylase and total protein concentrations between the beginning and the end of the 12 month trial. However, significant increases in albumin secretion into saliva and salivary lysozyme concentrations were observed. Total salivary IgG, IgA and IgM concentrations decreased significantly during the cancer therapy but values returned to the baseline levels after termination of treatment. Despite the well-known cytolytic effect of anticancer drugs, chemotherapy need not therefore be permanently detrimental to saliva.

Adult↗
PubMed1992

Rigid internal fixation of mandibular fractures. An analysis of 270 fractures treated using the AO/ASIF method.

The results are reported on 214 patients treated for 270 mandibular fractures, using rigid internal fixation. Of these, 172 fractures (63.7%) in 131 patients had been re-evaluated at final follow-up in connection with plate and screw removal, on average 15.2 months, postoperatively. Although one-third of the patients had a history of alcohol abuse, and 86% were treated with a delay of more than 24 h (mean 3.2 days), good primary bone healing was observed in 93.9% of the patients. Infections, seen in 6.1% of the patients, were related exclusively to inadequate stability of the fracture. Malocclusion, observed in 18.2% of 159 dentate patients, was caused by incorrect plate bending and insufficient fracture reduction. Immediate postoperative dysfunction of the inferior alveolar nerve in 58.1% of the cases, and of the mandibular branch of the facial nerve in 12.7%, was followed by almost total recovery 1 year after operation. It is concluded that rigid internal fixation is a reliable method of treatment, especially indicated for patients with reduced healing capacity and poor co-operation.

Adolescent↗