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Biomedical subjects

A Prokop

Publications and source records attributed to A Prokop.

At least 19 recordsLinked to original sources

Gram-scale synthesis of pinusolide and evaluation of its antileukemic potential.

Pinusolide (1), a known platelet-activating factor (PAF) receptor binding antagonist, was synthesized from lambertianic acid (2), a labdane-type diterpene readily accessible in multigram quantities from the Siberian pine tree. It was shown that 1 not only decreases the proliferation activity of tumor cells at relatively low concentrations but specifically induces apoptosis at 100 microM via the mitochondrial pathway in the Burkitt lymphoma cell line BJAB. Also, using primary lymphoblasts and leukemic cells from children with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML), a significant DNA fragmentation in pinusolide-treated cells could be detected in an ex vivo apoptosis assay.

Antineoplastic Agents↗

[Multislice CT in diagnostic work-up of polytrauma].

BACKGROUND: In severely injured patients, diagnostic procedures should be as brief as possible. With the use of spiral CT technology, the time required for diagnosis is minimized. QUESTION: Do severely injured patients benefit when primary diagnostic examinations are completed in less than 30 min? How much time is required for primary emergency department (ED) care and how much in the CT scanner? MATERIAL AND METHODS: Between 31 July 2001 and 31 December 2003, severely injured patients with ISS scores over 16 underwent total body spiral CT scans (Siemens Somatom Volume Zoom Multislice CT) after initial ultrasonography. One hundred patients (M:F=25:75) with an average age of 42 years (range: 3-81 years) were evaluated retrospectively. The average ISS score was 32.8+/-12 points (range: 17-75 points). RESULTS: The average time in the ED, prior to CT, was 33+/-14 min. The CT scans lasted 16+/-5 min and the total diagnostic time was 48+/-14 min. Fifty percent of patients were taken immediately to the operating room. The mortality rate in hospital was 13%. The average hospital stay was 30 days, with an average ICU stay of 10 days. CONCLUSION: The shorter the time spent in the ED, the shorter the stays in ICU and in total hospitalization were, regardless of injury severity. With structured management and shortening of diagnostic time with spiral CT, the time in the ED was decreased from 85 to 48 min.

Adolescent↗

Engineering challenges of BioNEMS: the integration of microfluidics, micro- and nanodevices, models and external control for systems biology.

Systems biology, i.e. quantitative, postgenomic, postproteomic, dynamic, multiscale physiology, addresses in an integrative, quantitative manner the shockwave of genetic and proteomic information using computer models that may eventually have 10(6) dynamic variables with non-linear interactions. Historically, single biological measurements are made over minutes, suggesting the challenge of specifying 10(6) model parameters. Except for fluorescence and micro-electrode recordings, most cellular measurements have inadequate bandwidth to discern the time course of critical intracellular biochemical events. Micro-array expression profiles of thousands of genes cannot determine quantitative dynamic cellular signalling and metabolic variables. Major gaps must be bridged between the computational vision and experimental reality. The analysis of cellular signalling dynamics and control requires, first, micro- and nano-instruments that measure simultaneously multiple extracellular and intracellular variables with sufficient bandwidth; secondly, the ability to open existing internal control and signalling loops; thirdly, external BioMEMS micro-actuators that provide high bandwidth feedback and externally addressable intracellular nano-actuators; and, fourthly, real-time, closed-loop, single-cell control algorithms. The unravelling of the nested and coupled nature of cellular control loops requires simultaneous recording of multiple single-cell signatures. Externally controlled nano-actuators, needed to effect changes in the biochemical, mechanical and electrical environment both outside and inside the cell, will provide a major impetus for nanoscience.

Animals↗

[Lecture disasters - and how to prevent them].

Presentations at medical conferences can sometimes confuse or compromise understanding of current topics. Although considerable time and financial costs may be taken to be present at such events, all too often one must go through inferior presentations that are poorly structured and do not contribute to one's understanding of the topic at hand. A good presentation is distinguishable by the clear intentions of the speaker to give a good lecture. The presenter has worked extensively with his topic and is familiar with the audience. The presentation has a clear structure and finishes with a take-home message. The speaker takes the listener from his previous level of knowledge to a new understanding. To do so, both voice and body language are used. The supporting slides are simple and direct, and not overloaded with information. The speech conforms exactly with the pre-determined time limit.

Audiovisual Aids↗

[ Intramedullary nailing (ESIN) in clavicular pseudoarthroses. Results of a prospective clinical trial].

This prospective clinical trial was performed to assess healing, clinical outcome and complications after intramedullary nailing of midshaft clavicular nonunions. Over 2.5 years, 14 patients were included. Exclusion criteria were pathological fractures, bony defects, previous operative therapy, atrophic and infection pseudarthrosis and the patient's age: <18 years or >70 years. Results were evaluated after 3, 6, 12 and 18 months. Beginning 3 months after the operation, pain (VAS), subjective satisfaction, Constant score and DASH score were significantly better than preoperatively during the follow-up period (p<0.001). There were no infections, no implant displacements or refractures.Intramedullary fixation of midshaft clavicular nonunions with an elastic titanium nail is a safe, minimally invasive surgical technique, producing excellent functional and cosmetic results without additional bone grafting.

Adult↗

[Treatment of mid-clavicular fractures in adults. Early results after rucksack bandage or elastic stable intramedullary nailing].

OBJECTIVES: The aim of this prospective study was to compare the results achieved in two groups of patients treated for mid-clavicular fracture. METHODS: The first group of 27 patients was treated nonoperatively with a rucksack bandage, whereas the second group underwent intramedullary fixation with a titanium pin, using a minimally invasive technique. Within the follow-up period of 6 months, results were evaluated seven times. RESULTS: During the whole period significantly (p<0.05) better results were observed in the group of operated patients concerning shoulder function, Constant score, DASH score, personal satisfaction, pain, and cosmetic result. In the second group return to work occurred in less than half the time of the first group. CONCLUSION: Intramedullary nailing of mid-clavicular fractures is a safe and minimally invasive operation technique. Early functional and cosmetic results are not worse than results after nonoperative treatment with a rucksack bandage.

Adolescent↗

[Multistep surgery for spondylosyndesis. Treatment concept of destructive spondylodiscitis in patients with reduced general condition].

OBJECTIVE: Retrospective assessment of multistage surgery in the treatment of progressive spondylodiscitis in patients with critical physical status. PATIENTS: A total of 34 patients (mean age 58.6 years) with 37 progressive spondylodiscitis foci and destruction of one to three vertebral segments (1.9 mean) were recorded within an 8-year period. Time between first complaints and operative treatment was 3 months (mean). Preoperative health status was critically reduced in 11 patients (ASA IV) and poor general condition (ASA III) was seen in 23 patients when vital indication was seen preoperatively. Considerable systemic disease (n=31), further infection focus (n=18), and nosocomial trauma (n=5) were causally related. Spondylodiscitis was seen more frequently in the lumbar (n=20) and thoracolumbar than in the thoracic (n=10) and cervical spine (n=1). Staphylococcus aureus was detectable from operative specimens and hemoculture in 15 cases, MRSA in 6 of these. METHODS: In cases of monosegmentary involvement (n=7) ventral debridement, biopsy, and application of antibiotic chains were followed by autologous interbody bone grafting in a second stage operation. In 29 cases with destruction of two (n=27) and three (n=3) segments, posterior instrumentation including laminectomy in 4 patients was completed by anterior debridement and application of antibiotic chains during a first surgical intervention. After stabilization of physical condition and having reached a macroscopically indisputable implant bed, the ventral fusion with autologous interbody bone grafting or cage in combination with a plate or internal fixation system was performed as the last of several surgical steps. RESULTS: No case of perioperative mortality was observed. Intensive care continued 9.1 days and hospitalization 49.5 days (mean). During a 37.6-month follow-up two late recurrences were observed. CONCLUSION: A multistep surgical procedure under protection of dorsal instrumentation can limit perioperative mortality in patients in critical general condition by avoiding an extended one stage dorsoventral spondylodesis. After eradication of further infection foci and stabilization of physical condition, ventral instrumentation is completed under elective conditions.

Adult↗

[Pitfalls and complications of elastic stable intramedullary nailing (ESIN) of femoral fractures in infancy].

BACKGROUND: The aim of this prospective study was to evaluate the intra- and postoperative problems as well as the complications of elastic stable intramedullary nailing (ESIN) of femur fractures in children. PATIENTS AND METHODS: 47 consecutive children, mean age 6 years, were reviewed clinically and radiologically until hardware removal and after this annually. Mean time of follow up was 37 months. RESULTS: Intraoperatively one cortex perforation and one displacement of a third fragment occurred. Two correction operations were necessary: In one case due to an implant displacement and in another case due to an unacceptable loss of reduction. There were no infections, non union, implant breakage, refracture or disturbance of growth. CONCLUSIONS: ESIN is a safe procedure in femoral shaft fractures of children. Most of the problems and complications can be avoided by a careful consideration of the indication and a correct operation technique.

Bone Nails↗

[Experience with elastic stable intramedullary nailing (ESIN) of shaft fractures in children].

The aim of this prospective clinical controlled trial was to investigate the early and midterm results of shaft fractures in children treated with elastic stable intramedullary nailing (ESIN). From January 1997 to December 2001, elastic stable intramedullary nailing was carried out on 112 children with 118 diaphyseal fractures. The mean age was 7.7 years. There were 51 fractures of the lower arm, 46 femoral fractures, 14 of the lower leg, and 7 of the humerus. A total of 92 children have been followed up for more than 12 months. The mean time of follow-up was 38 months.The mean time of fluoroscopy was 2.2 min. Open reduction was necessary in 3.4 %. In children with injuries of the lower extremity, full weight bearing was achieved after a mean period of 9.3 days. In 1.8% of the children, reoperation was necessary within the first 10 days after the operation. In 3.6 % there was painful skin irritation due to the protruding end of a nail. No infection or delayed union was observed. Implant removal was done after a mean time of 5.6 months. There was no rotational or angular deformity of more than 5 degrees in children with isolated fractures of the lower extremity. Mean lengthening of the injured leg was 2.4 mm. In three children who had fractures of the upper extremity, a deficit in range of motion of the adjacent joints was detected. The current results show that intramedullary fixation of displaced diaphyseal fractures in children with a flexible titanium nail is a safe, minimally invasive surgical technique producing excellent functional and cosmetic results.

Arm Injuries↗

[Use of the injectable bone cement Norian SRS for tibial plateau fractures. Results of a prospective 30-month follow-up study].

Reduction of the depressed joint surface in tibial plateau fractures often leaves large cancellous bone defects. These metaphyseal voids are typically filled with autogenous bone grafts that can cause a significant donor site morbidity. The use of injectable bone cement offers the opportunity to support the reduced joint surface without bone grafting. The aim of this study was to evaluate the clinical and radiological outcome as well as the period of partial weight bearing after the use of Norian SRS in tibial plateau fractures. Twenty-one patients with a mean age of 48 years were included in this prospective trial. According to the AO/OTA Classification, there were seven fractures of type B2, ten B3, one C1, one C2, and two fractures of type C3. The period of partial weight bearing was 3.7 weeks. In 18 patients the follow-up was more than 24 months. After a mean follow-up of 30 months, the Lysholm score was 87.9 at mean. The radiological part of the Rasmussen score was excellent and good in eight cases each and fair in four cases. Soft tissue reactions due to the cement were not observed. On all radiographs taken 36 months after the operation the cement bloc was still visible. The results show that Norian SRS can be used to fill metaphyseal bone defects in tibial plateau fractures. Clinical and radiological results are comparable to those of fractures treated with autologous bone graft. The high compression strength allows early full weight bearing without the risk of secondary loss of reduction.

Adult↗

Soft tissue reactions of different biodegradable polylactide implants.

Soft tissue reactions resulting from biodegradable polylactide implants to bone have not been adequately examined during their 3-year degradation period. An osteotomy was performed on the medial femoral condyle of 36 sheep and secured by either three poly-L-DL-lactide pins (70/30) (Polypin) or three composite pins [10% beta-tricalcium phosphate (beta-TCP) (90/10)]. A histological examination was performed on the synovial membrane and lymph nodes after 3, 18 and 36 months. After 18 months two non-specific, minor reactions of the synovial membrane were observed in the composite pin group. In both groups different reactions of both inguinal lymph nodes were observed. These had no statistical relevance and could not be clearly attributed to the implants. Due to the slow degradation process of biodegradable polylactide implants, there is no clinically relevant inflammation of either joint or lymph nodes. The addition of 10% beta-TCP did not result in any significant enhancement.

Animals↗

[Risk factors for the development of pneumonia in multiple injured patients. Results of a prospective clinical trial].

Pneumonia is the most common infectious complication in multiple trauma patients. In a prospective clinical cohort study, 266 multiply injured patients were examined for the development of pneumonia. Various risk factors were tested in uni- and multivariate analyses. Three different definitions of pneumonia were used in order to examine how results depended on definition. The incidence of pneumonia was 41%, but varied with definition (30-50%). Injuries to the thorax, head,and abdomen were associated with a significantly increased risk of pneumonia (adjusted relative risk: 1.77, 1.97,and 1.52, respectively).Furthermore, increasing age led to a higher risk of pneumonia. Although the primary analysis revealed a higher pneumonia risk in male patients (adjusted relative risk: 2.23; 95% CI: 1.43-3.05), this result could not be consistently reproduced when using other definitions of pneumonia. Trunk and head injuries and age are proven risk factors for developing posttraumatic pneumonia. The association between male gender and an increased rate of infectious complications remained questionable.

Abbreviated Injury Scale↗

[Tossy III injuries of the acromioclavicular joint. In what circumstances is surgery still justified? Personal results and literature review].

In Germany AC-joint-dislocations type Tossy III are treated in most of the cases operatively. Over two times of period we treated AC-joint-dislocations type Tossy III with biodegradable PDS-cords. 54 patients were operated between 1989 and 1997 and followed up after 39 months. 87.5% of patients are satisfied with results and have 10.2 points at Taftscore. In this period we couldn't differentiated the results by Rockwood classification. 12 patients with Rockwood V were operated between 1998 and 2002 and followed up after 14 months. Excellent and good results were seen in 92% of cases. At Taftscore we seen 10.7 points. 3 patients with Rockwood III were treated conservative with 10.3 points and 3 patients were operated with 10.7 points at Taftscore. AC-joint dislocations should be classified to Rockwood. No differences were seen between operation and conservative treatment in Rockwood III in literature. We recommend operation with PDS cords with good results in Rockwood V.

Acromioclavicular Joint↗

Elastic stable intramedullary nailing of midclavicular fractures in athletes.

BACKGROUND: Intramedullary fixation of midclavicular fractures may be a better option than non-operative treatment for high performance/professional athletes because of the potential reduction in recovery time. OBJECTIVES: To evaluate the effectiveness of intramedullary fixation in high performance athletes and the time required to return to sporting activity. METHODS: Data were taken from a prospective study on intramedullary fixation techniques using the elastic stable Ti nail (TEN, Synthes) for the treatment of displaced midclavicular fractures, initiated in 1996. The patients in 12 cases were classified as high performance/professional athletes. These cases were used to evaluate the technique specifically in this population. Fractures were classified according to the Orthopaedic Trauma Association (OTA) system. Patients were evaluated before and after surgery for shoulder function and subjective pain. After the operation, radiological assessments documented fracture healing, and clinical outcomes scores were obtained. Time required to return to training and competition was documented. RESULTS: All fractures were transverse or oblique. Mean (SD) shoulder abduction increased from 36.3 (8) degrees before surgery to 154.2 (17) degrees afterwards (p<0.001). Mean subjective pain score using a visual analogue scale (0-100) decreased from 71.7 (18) points before surgery to 19.2 (6) points (p<0.001) three days after. There were no complications. Hospital stay averaged 2.9 (1) days. Mean delay to resumption of training was 5.9 (1) days, and to resumption of competition it was 16.8 (5) days. The mean Constant clinical outcomes score one year after hardware removal was 98.3 (2) points. CONCLUSIONS: Intramedullary fixation of displaced midclavicular fracture was successful in terms of clinical outcome and rapid resumption of sporting activities. This treatment should be offered to athletes as an alternative to non-operative treatment.

Adolescent↗

[Reconstruction of shoulder-girdle symmetry after midclavicular fractures. Stable, elastic intramedullary pinning versus rucksack bandage].

The aim of this study was to compare the results achieved in two groups of 20 patients treated for midclavicular fracture. The first group (mean age 36 years) was treated non-operatively with a rucksack bandage, whereas the second group (mean age 37 years) underwent intramedullary fixation with a titanium pin using a minimally invasive, unreamed technique. At follow-up, which averaged 3.1+/-0.9 years in group 1 and 2.9+/-0.7 years in group 2, the result of treatment, as indicated by the Constant score, functional outcome and cosmetic outcome, was significantly better in the group undergoing operative treatment. Clavicle shortening was significantly ( P=0.027) higher in patients treated with a rucksack bandage. The absolute Constant score averaged 78+/-23 in group 1 and 97+/-4 in group 2 ( P=0.001). The Constant rating scale showed a significant difference between patients with clavicle shortening of less than 1 cm and 1 cm shortening or more. There were two non-unions in group 1 but none in group 2. Refractures were not observed in either group. According to these results, intramedullary fixation with a titanium pin seems to be more advantageous in midclavicular fractures than non-operative treatment. As the operation is well received by the patients, it should be offered to them as an alternative treatment to the rucksack bandage.

Adolescent↗

[New biodegradable polylactide implants (Polypin-C) in therapy for radial head fractures].

Dislocated radial head fractures of the type Mason II are usually treated with screws and buttress plates. The implants are generally removed at a later date. Biodegradable implants can be applied successfully for the reduction of small radial head fractures subject to shearing forces and slight loads. The implants are completely absorbed once the fracture has healed, making a second operation for the removal of the implant unnecessary. The Polypin C-Pin is made of poly(L, DL-lactide) mixed with 10% beta-tricalcium phosphate to ensure controlled, slow degradation with no significant side effects. This new Polypin C fixation pin was clinically tested on 35 patients with radial head fractures (CCF 21B2.1 and 21B2.2) from 31.10.1996 until 1.4.2002. A total of 34 of the patients (97.1%) underwent a clinical and conventional radiological follow-up examination after an average of 38.2 months. In 29 cases a CT was also carried out. Between 18 and 24 months, two cases of grade 1 osteolysis were observed around the pin head. No trace of osteolysis was observed at the final examination in either case. According to the Broberg score, an average of 96 out of a possible 100 points were attained at the final examination (31 excellent, 2 good, 1 unsatisfactory). After a period of 24 months, the pins were no longer visible on a conventional x-ray. A CT evaluation showed a density similar to that of spongioid bone in the original pin cavities after 3 years. These excellent clinical results prove that the Polypin C is a good method to treat dislocated radial head fractures.

Absorbable Implants↗

[Linezolid--a new antibiotic for treatment of methicillin resistant Staphylococcus aureus infections in trauma surgery? Report of 2 cases].

PROBLEM: Infections with Methicillin-resistant Staphylococcus aureus are reported increasingly in intensive care unit and ward, that means not only a dangerous disease but also a considerable expenditure factor. METHODS: In trauma surgery we could observe the Linezolid treatment of 2 patients with a MRSA infection. After treatment with Vancomycin and further evidence of MRSA the application of Linezolid was continued during 3 weeks accompanied by further microbiologic investigations. RESULTS: In a 73 year old man with humerus shaft fracture the MRSA osteomyelitis was eradicated with Linezolid (600 mg/day per os over 3 weeks) after radical débridement and reosteosynthesis. The MRSA pneumonia in a 14 year old girl was treated successfully by Linezolid (600 mg/day i.v. over 3 weeks) and pneumotherapy. Follow up excluded further MRSA infection. CONCLUSIONS: Linezolid represents an efficient new reserve antibiotic. In case of pneumonia, severe skin and soft tissue infections good results can be expected. The treatment of osteomyelitis has been reported only in single cases.

Acetamides↗

[Palmar lunate dislocation].

UNLABELLED: Palmar lunate dislocation as the end stage of a perilunate dislocation is a very uncommon injury. Having treated 19,534 hospitalized patients between 1 January 1986 and 1 October 2001 the diagnosis was recorded in four male trauma patients (33, 36, 37 and 62 years old). Among the operatively treated carpal dislocations and carpal fracture dislocations those of the lunate were seen in five per cent. The dislocation was caused in by an acute hyperextension injury resulting of falls from heights in three cases, and of a motorcycle accident in a further case. In two of these cases a complete palmar lunate dislocation was analysed that were produced by fall from seven meters heights of a young craftsman and by accident of a motorcyclist. First using a longitudinal palmar approach in both cases a revision of the hemorrhagic carpal canal was performed urgently, the largely denuded lunate was reduced and the repair of identified ligamentous structures was performed by means of sutures respectively suture anchors. Reduction was stabilized with Kirschner wires. Afterwards performed computed tomography identified the result of reduction and associated defects (subluxation distal radioulnar joint). In one patient a soft tissue infection prevented the dorsal ligamentous repair. In spite of a consequent after-treatment and a good functional result a scapho-lunate dissociation was proved. An avascular defect of the lunate could be excluded by magnetic resonance imaging. In case of a secondary performed dorsal repair a persisting carpal stabilization with a satisfactory functional result could achieved. At second hand an advanced carpal collapse was proved. CONCLUSIONS: If reduction cannot be achieved by closed manipulation or a loss of reduction is shown, open reduction is indicated first by a palmar approach. An additional dorsal ligamentous repair seems to be necessary. Transfixation by Kirschner wires and suture anchors stabilize the restored anatomic relationships. Wrist immobilization in a cast for at least eight weeks is recommended. Although ligamentous insufficiency, osteoarthrosis and avascular necrosis are often proved, functional results are satisfactory.

Adult↗