[Ankle arthrometry for evaluation of the mechanical component in chronic ankle instability]

BACKGROUND

Chronic ankle instability (CAI) is a term that is not well defined until now in spite of a large body of respective literature. Most frequently this umbrella term is used synonymously for functional ankle instability and the role of the mechanical component is not fully understood.

PATIENTS/MATERIAL AND METHODS

In a cohort consisting of 15 patients suffering from CAI we preoperatively investigated the mechanical component using both stress radiographs and ankle arthrometry. The functional impact was measured with the FAAM-G (foot and ankle ability measure, German version). The results were compared with a respective group of 17 uninjured subjects.

RESULTS

Relevant differences were found between the patients and the uninjured groups in the mechanical (stiffness in the 40 - 60 N region of the load deformation curves and the ratio between stiffness in the 125 - 175 N and 40 - 60 N region) and functional analyses (FAAM-G), respectively (p < 0.001 - 0.040). There was no difference found between groups in the upper (125 - 175 N) region of the load deformation curves.

CONCLUSIONS

This article helps to clarify the role of the mechanical component in CAI. Patients suffering from both functional and mechanical ankle instability can be detected with the FAAM-G questionnaire and with different ankle stiffness parameters from ankle arthrometer stress testing. These measures differentiate CAI patients from uninjured persons with functionally and mechanically stable ankles. Therefore, these instruments can be recommended to diagnose and quantify the mechanical component in CAI.

[Extracorporeal shock wave therapy for patients suffering from recalcitrant Osgood-Schlatter disease]

BACKGROUND

Intensive physical load can damage epi-/apophyseal growth. Osgood-Schlatter disease is a well-known and sport-associated overuse injury of the tibial tuberosity apophysis. Long-lasting load-associated pain and a reduced ability to play sports can be the consequence.

AIM OF THE STUDY

The aim of this study was to analyse the safety and effectiveness of extracorporeal shock wave therapy (ESWT) for recalcitrant Osgood-Schlatter disease.

PATIENTS AND METHODS

14 adolescent patients, median age 14 (13.2-14.7) years, suffering from recalcitrant Osgood-Schlatter disease (16 symptomatic knees) were treated with radial extracorporeal shock waves. The nine boys, median age 14 (13.5-15.0) years and the five girls, median age 12 (10.8-15.2) were retrospectively followed up 5.6 (3.4 - 6.7) years later using the disease specific VISA-P-G questionnaire which is validated for jumper's knee.

RESULTS

At follow up the median VISA-P-G score was 100 (82.9-100.9). Twelve of 16 knees (75%) reached 100 out of 100 VISA-P-G points. Four patients changed their sports activity due to persisting problems at the distal patellar tendon insertion. Four knees had persisting tibial tuberosity pain when playing sport. Pain induced by activities of daily living (stair climbing) was stated in two cases. No side effects or long-term complications were reported.

CONCLUSIONS

This pilot study demonstrates that radial ESWT is a safe and promising treatment for adolescent athletes with recalcitrant Osgood-Schlatter disease.

[Validation of the VISA-A-G questionnaire for German-speaking patients suffering from Haglund's disease]

BACKGROUND

The VISA-A questionnaire is currently the only valid, reliable, and disease specific patient administered questionnaire for research in Achilles tendinopathy. To perform multinational and multilingual investigations this instrument was already adapted to several languages. According to the "guidelines for the process of cross-cultural adaptation of self-report measures" we already translated and validated the VISA-A questionnaire for patients with Achilles tendinopathy.

AIM OF THE STUDY

To cross-culturally adapt and validate the VISA-A Questionnaire for German-speaking patients suffering from Haglund's disease.

METHODS

The VISA-A-G questionnaire was tested for reliability, validity, and internal consistency in 39 Haglund's disease patients and 79 asymptomatic persons. For concurrent validity the VISA-A-G was compared with the Curwin and Stanish tendon grading system and with the Percy and Conochie classification system for the effect of pain on athletic performance. VISA-A-G results in Haglund's disease were additionally compared with VISA-A-G results obtained from Achilles tendinopathy patients and with VISA-A results presented in the international literature.

RESULTS

ICC for the VISA-A-G questionnaire in conservatively treated Haglund's disease patients was 0.96. In asymptomatic students and joggers ICC was 0.97 and 0.60. When correlated with the grading system of Curwin and Stanish and with the Percy and Conochie classification rho was -0.95 and 0.94, respectively. Internal consistency (Cronbach's alpha) for the total VISA-A-G scores of the patients was calculated to be 0.87. Compared with VISA-A-G results obtained from Achilles tendinopathy patients there was no relevant difference discernible. Compared with VISA-A results presented in the original publication no difference was found statistically for students, healthy people, conservative, and preoperative patients, respectively.

CONCLUSIONS

This study confirms that the VISA-A-G is a valid and reliable measure for German-speaking patients suffering from Haglund's disease.

Translation, cross-cultural adaption and validation of the German version of the Foot and Ankle Ability Measure for patients with chronic ankle instability

OBJECTIVES

The evaluation of health-related quality of life and physical function is important for determining therapeutic strategies following ankle injuries. The Anglo-American Foot and Ankle Ability Measure (FAAM) is a valid and reliable self-reported measure to detect functional deficits in chronic lateral ankle instability. The purpose of this study was to translate, cross-culturally adapt and validate the FAAM questionnaire for use with German-speaking patients with chronic lateral ankle instability.

PATIENTS/PARTICIPANTS

Preoperative and conservatively treated patients with chronic lateral ankle instability. Sport students and volleyball athletes served as control groups.

MAIN OUTCOME MEASUREMENTS

The FAAM was forward and back translated, cross-culturally adapted and validated. The study population completed the FAAM-G questionnaire twice within 3-5 days. Additionally, the patients were scored with the Good ankle laxity classification system. Test-Retest reliability, construct validity and internal consistency were calculated.

RESULTS

Reliability and validity of the FAAM-G were examined in presurgical chronic ankle instability patients (n=24), conservatively treated chronic ankle instability patients (n=17), university sport students (n=31) and volleyballers (n=37). Test-retest reliability revealed fair, good, or excellent reliability (inter-class correlation coefficient (ICC)=0.590-0.998; ρ=0.528-1.000). Construct validity, tested between the FAAM-G subscores and the Good et al ankle laxity classification system demonstrated strong correlations (ρ = -0.819 to -0.861).

CONCLUSIONS

The original FAAM questionnaire was successfully translated and cross-culturally adapted from English to German. Corresponding to the Anglo-American version, the FAAM-G is a reliable and valid questionnaire for self-reported assessment of pain and disability in German-speaking patients suffering from chronic ankle instability.

[Minimally invasive repair of an impingement induced partial tear of the anterior Achilles tendon in a top level athlete]

AIM

A rarely described Achilles tendon lesion resulting from Haglund's disease and its repair is presented.

METHOD

An analysis of the respective clinical records was carried out.

RESULTS

Haglund's resection was performed from a 3 cm lateral transverse approach. A coincidental anterior Achilles tendon partial tear was repaired by transversal U-sutures.

CONCLUSION

A minimally invasive repair of a partial tear of the anterior Achilles tendon is feasible and effective.

[Balance therapy shoes - a comparative analysis with respect to immediate training effects]

BACKGROUND

Manufacturers attribute specific shoes and sole construction to induce neuromuscular training. Thus injury prevention or rehabilitation from injury is aimed.

HYPOTHESIS

H1=Different shoe and sole construction result in different load to the neuromuscular system and postural control.

STUDY DESIGN

Controlled laboratory study.

METHODS

10 healthy subjects were tested postural stabilization using a force plate and EMG-recordings. First each person performed three 20 sec single leg unshod stance trial (control condition). Then MBT shoe, Finnamic-Rollenschuh and ReflexControl were applied and tested in a randomized order.

RESULTS

No difference in the EMG- activity was detected comparing the barefoot condition with MBT and Finnamic-Rollenschuh (p=0,051-1,000). However with one exception (barefoot M. gastrocnemius. EMG-activity; p=0,110) putting on the ReflexControl shoe increased the EMG-activity relative to all three tested muscles and shoe/barefoot conditions (p=0,000-0,001). Moreover, the ReflexControl shoe led to a highly significantly higher postural sway (p=0,000-0,072), while MBT, Finnamic-Rollenschuh and barefoot conditions were not statistically different (p=0,818-1,000).

CONCLUSIONS

This study confirms that during upright stance the ReflexControl shoe is a means for neuromuscular training, while MBT and Finnamic-Rollenschuh simulate barefoot stance.

Dorsal calcaneocuboid ligament versus lateral ankle ligament repair: a case-control study

OBJECTIVE

Anatomic reconstruction is the treatment of choice for lateral ankle ligament instability. A similar technique has recently been described for stabilisation of a chronic unstable calcaneocuboid joint as an alternative to the previously proposed tenodesis and arthrodesis procedures.

METHODS

Five consecutive young females experiencing recurrent giving way of six calcaneocuboid joints were treated operatively during a 4 year period using anatomic ligament repair reinforced by a periosteal flap. Results were compared to five patients who underwent anatomic lateral ankle ligament repair in a case-control design. Outcome was measured using the Foot and Ankle Outcome Score, physical examination, and stress radiographic and MRI (calcaneocuboid group) investigation. Functional neuromuscular performance was evaluated by isokinetic torque measurements, posturometry, single-leg drop jumps, and single-leg long jumps.

RESULTS

Outcome scores at follow up (5-61 months after surgery) revealed excellent results for both groups. No relevant difference was found between the affected legs and the non-affected legs or between groups with respect to the outcome measures. MRI exhibited ligament-like structures at the repaired dorsal calcaneocuboid joints in five out of six joints.

CONCLUSIONS

Results of anatomic repair of unstable lateral ankle and isolated calcaneocuboid joint instability equally lead to excellent results.

Flexor-hallucis-longus-Sehnenruptur als Impingementläsion bei instabilem Os trigonum

A Flexor hallucis longus tendon lesion induced by an unstable Os trigonum has not been described heretofore. A 39 years old karateka complained increasing load induced pain at the posteromedial ankle. Because of this, he was unable to take part in sports activities. Clinical, X-ray and MRI investigation assumed a Flexor hallucis longus tendon tear induced by an impingeing Os trigonum. At surgery a longitudinal and a partial transverse tendon tear was present. The Flexor hallucis longus tendon pulley was narrowed by a partially unstable Os trigonum. Tendon reconstruction, Os trigonum removal and early functional posttreatment resulted in full ability in sport, leisure-time activities and profession five months later.

Kombinierte chronische Instabilität des lateralen oberen Sprung- und des dorsolateralen Calcaneocuboidalgelenks

Up to now there was no publication describing a combined instability of the calcaneocuboid and lateral ankle joint. A 38 years old teacher (a former gymnast) complained about increasing giving way symptoms and pain at the lateral foot and ankle. Because of this, he was unable to take part in sports activities. Clinical investigation revealed lateral ankle and calcaneocuboid joint instability. Surgical treatment was done using periosteal flap augmented capsular reefing for both joints, resulting in full ability in sport and profession four months later.

Die Impingementläsion der distalen Achillessehne bei Bursitis subachillae und Haglund-Pseudoexostose - eine therapeutische Herausforderung

Retrocalcaneal bursitis in athletes is frequently misdiagnosed. Results of conservative treatment are not very promising. This investigation evaluates the results of 39 consecutive cases in 38 patients surgically treated due to chronic retrokalkaneal bursitis in a sport specific population. Preoperative MRI and ultrasound investigation showed corresponding lesions (focal degeneration, partial rupture) of the anterior Achilles tendon. This is possibly the result of a previously undescribed impingement lesion produced by the Haglund's bone and the chronically inflamed retrocalcaneal bursa. During operation this lesion was additionally addressed in 85% of the cases. Follow up was done after 32 months. Success rate was 54%. VISA-A Score at follow up was 80.6 points. Training and competition activities were started at 16 weeks and 9 months respectively. Unsatisfying results were analysed. In two cases Haglund's bone resection was incomplete and had to be removed in a reoperation. Additionally one deep wound infection had to be revised. Due to the distal Achilles tendon fiber extensions around the medial and lateral calcaneal bone, an unintended Achilles tendon lesion, induced by the edge of the osteotome seems to be possible. Two calcanear stress fractures complicated the postoperative rehabilitation.

The c-myc oncogene: use of a biological prognostic marker as a potential target for gene therapy in melanoma

The c-myc oncogene has been shown to be overexpressed in a number of malignancies, and may play an important role in the pathogenesis of malignant melanoma. Previous prognostic studies have demonstrated c-myc overexpression in a range of cutaneous melanomas, and levels of c-myc oncoprotein expression have been shown to correlate with clinical outcome in both primary and secondary disease. The purpose of this study was to investigate the in vitro manipulation of c-myc expression using antisense oligonucleotides. The human melanoma cell lines A375M, Be11 and WM115 were treated with c-myc antisense oligonucleotides, and the cellular growth was compared with controls. Antisense oligonucleotides reduced the growth rate of all three cell lines, and produced a reduction in c-myc gene expression as measured by flow cytometry. The growth inhibitions in the A375M, Be11 and WM115 cell lines at 72 h were 36.6%, 35.8% and 29.3%, respectively. Each of these was significantly different from control cultures (P<0.01). The c-myc antisense produced a mean 75% reduction in c-myc oncoprotein expression when compared with controls in the A375M cells (P<0.001), a 49% reduction in the Be11 cells (P<0.001) and a 28% reduction in the WM115 cells (P=0.005). This study demonstrates the importance of the c-myc oncogene in controlling melanoma growth. It suggests that blocking the expression of this gene, using an antisense approach, reduces melanoma cell growth, and may potentially provide a novel gene-therapy strategy for the treatment of advanced melanoma.

[Orthopaedic examination of gymnasts]

A gymnast is prone to catch specific acute and overload injuries as well. Those injuries are concentrated at the spine due to the fact, that high load is administered to the growing apophyseal elements. Preventive X-ray examinations are useless in this respect, because the gymnasts training starts at the age of 5-6 years and apophyseal ossification nuclei develop not before the age of about 11-13 years. On the other hand regular performed preventive clinical examinations seem to be important for preventive reasons. For this purpose we developed specific clinical tests which allow early recognition of overuse injuries while they are in a latent phase and while the athlete does not complain any pain. Furthermore staging of the injury is possible and healing response can be controlled.

MP I joint giving way--a case study

A case history of a 26 year old international class female 400 m hurdle sprinter is presented. While sprinting she felt a sudden and very intensive pain at her left hallux. After this she was unable to run and had episodes of giving way in the MP I joint elicited by minor activity. Operative investigation revealed a broad disruption of the MP I medial collateral ligament. After periosteal flap repair and early functional aftertreatment she returned to full high level sports ability.

Functional properties of adhesive ankle taping: neuromuscular and mechanical effects before and after exercise

The purpose of the study was to investigate effects of adhesive ankle taping. Using electromyographic, goniometric, and thermologic methods, different ankle tapes were tested before and after athletic exercise in simulated inversion trauma. Twelve subjects with stable ankle joints performed five trials: with two different materials, with two taping techniques, and one trial without tape as control. After the simulated inversion trauma, approximately 35% of the initial maximum inversion amplitude was decreased by ankle taping. Depending on the technique, there was a loss of tape stability < or =14% after 30 min of athletic exercise. Thermologic analysis revealed a postexercise 6 degrees C temperature increase in the foot, especially under the tape. Initially, interpreted as the primary effect, the improved joint stabilization is based on mechanical stiffness caused by the adhesive tape. Joint stability was influenced positively by neuromuscular proprioceptive and physiological processes, characterized by relatively increased electromyographic activation.

Neuromuscular properties and functional aspects of taped ankles

We used electromyographic and goniometric methods to test 40 subjects to describe the neuromuscular and biomechanical adaptation of the ankle with respect to application of two different adhesive tapes and to exercises. The neuromuscular responses to inversion injury simulation, together with the mechanical displacements of the joint complex, were analyzed before and after controlled athletic exercises. The proprioceptive amplification ratio was calculated on the basis of the integrated reflex electromyographic results and on the maximum inversion amplitude. Relevant stability gains were achieved immediately after applying tape. There was reduced tape stability after athletic exercise for one of the two tape materials tested. No further loosening was detected, even after prolonged wearing of tape (24 hours). Compared with the unprotected ankle, the taped ankle had a significant increase in the proprioceptive amplification ratio. Both fatigue and mechanical loosening may be responsible for the significant reduction in this ratio immediately after exercise. After the 24-hour interval, the ratio was increased, which could be explained by physiologic neuromuscular regeneration and mechanical restabilization of the tape itself. The sensitivity of the proprioceptive amplification ratio, both to external stabilization and to internal fatigue, supports its potential value to quantify functional joint stability.

[An increased risk of spinal injury in high performance gymnasts during pubertal growth?]

Elite womens gymnastics has generally been described to induce vertebral overload injuries, especially in the pubertal growth phase. This paper describes the results of a 4-year prospective longitudinal and transversal investigation of German elite womens gymnasts with respect to the spine. The main results are: 1) Pathological changes are detectable by clinical investigation before X-ray abnormalities can be found. 2) A sensitive test is the spine springing test. 3) Functional abnormalities can be detected especially in the lumbosacral region. 4) There were no spondylolyses. 5) Osteochondrotic lesions are frequent. They are concentrated in the dorsolumbar region.

Sensitivity of testis tumour cells to chemotherapeutic drugs: role of detoxifying pathways

In contrast to most other types of cancer, metastatic testicular germ cell tumours (TGCT) are cured in most patients using cisplatin-based combination chemotherapy. The biochemical mechanisms underlying this sensitivity have not been defined. Drug detoxification can modulate response to chemotherapy in vivo and in vitro, and therefore we measured levels of glutathione (GSH), glutathione-S-transferase (GST) and both constitutive and cisplatin- and dexamethasone-induced levels of metallothionein (MT) in five human testis tumour cell lines. The levels were compared with those in five human bladder cancer cell lines and two cell lines with cisplatin resistance acquired in vitro. GSH levels were relatively low in the testis tumour cell lines, as might be expected in drug-sensitive cells, and there was a 77-fold increase in GSH levels in the cisplatin-resistant testis tumour cell line. GST levels were similar in the two cell types, while metallothionein levels were relatively high in the testis tumour cell lines. These data indicate that GSH may contribute to the sensitivity of TGCT to chemotherapy, and that GSH expression may be involved in the acquisition of cisplatin resistance in these tumours.

Defects in the kinetics of the repair of DNA double-strand breaks and inhibition of DNA synthesis in the ataxia telangiectasia AT5BI-VA cell line: comparison to a corrected hybrid, atxbc

The nature of the primary biochemical defect in the human radiosensitive and cancer-prone syndrome, ataxia telangiectasia (AT), has remained obscure despite many efforts to elucidate it. In this study, AT complementation group D cells and a nearly isogenic corrected AT-hamster hybrid derivative have been analyzed for induction and repair of initial double-strand breaks (DSBs) after exposure to ionizing radiation, using a sensitive field-inversion electrophoresis technique. Results suggesting that initial levels of damage are the same in these two cell types, but indicating differences in the fast component of DNA repair, have been compared and correlated with those resulting from a study of the radioresistant DNA synthesis defect and its correction in the same cell lines. These measurements show that the radioresistant phenotype of the substantially corrected AT-hamster hybrid correlates with its higher level of fast-component DSB repair and higher level of inhibition of DNA synthesis, but that the initial damage induction does not contribute to the phenotype. We propose that the AT gene product(s) is likely to act early in a signaling pathway which controls both DNA repair and progression of cells through the phases of the cell cycle in response to ionizing radiation.

Increased DNA-repair capacity and the modulation of 2 proteins in and metallothionein overexpressing Chinese hamster cell line

Elevated intracellular levels of metallothionein have been associated with resistance to the cytotoxic effects of some alkylating agents. In order to study the mechanisms responsible for this resistance, we used a pair of CHO cell lines consisting of normal K1-2 cells and their derivative K1-2MT, which overexpresses the human metallothionein II-A gene (Lohrer et al., 1989). K1-2MT cells were found to be resistant to cadmium chloride and the alkylating agents N-methyl-N'-nitro-N- nitrosoguanidine (MNNG), but resistance did not extend to the alkylating agent, 1,3-bis(2-chloroethyl)- 1-nitrosourea, nor to adriamycin, an inhibitor of DNA synthesis. The DNA damage caused by MNNG, was only marginally less in resistant cells compared with the parental cell line, thus excluding drug scavenging as a possible mechanism for resistance. Also, glutathione S-transferases (GSTs) were present at equal levels in both cell lines (acidic and basic type GST) or slightly reduced in drug resistant K1-2MT cells (neutral type GST), thereby ruling out metabolic inactivation of the alkylating agents. However, the drug resistant phenotype was accompanied by a more efficient block of DNA synthesis after MNNG treatment and by a 3-h delay in the G2 phase of the cell cycle. Using two-dimensional gel electrophoresis of total protein extracts, we identified a 24-kDa protein (MIP1), which is only present in the resistant K1-2MT cells, and a 23.5-kDa protein (MIP2) which is 2-3 times over-synthesized in K1-2MT cells. MNNG treatment reduced the level of both proteins MIP1 and MIP2. These results suggest that the proteins MIP1 and possibly MIP2 may be responsible for the alkylating agent resistant phenotype and are probably modulated by the human metallothionein II-A protein.

Orthotic devices in functional treatment of ankle sprain. Stabilizing effects during real movements

Various orthotic devices generally employed for therapy of ankle sprain were tested under functional conditions. The experimental setup comprised inversion stimuli of 20 and 30 degrees (13 subjects) while standing on a tiltplatform as well as running movements of 8 and 12 km.h-1 on a treadmill (12 subjects). Ankle joint displacements were registered together with the surface EMGs from mm. peroneus long., tibialis ant., gastrocnemius med. and vastus med. In an additional study the relation between achilles tendon angle and talar tilt was determined under static conditions. Ten subjects with chronical instability were examined both in uni- and bipedal stance with the foot inverted to 20, 30 and 40 degrees. None of the tested devices could reduce achilles tendon angle movements completely neither during a sudden inversion nor during running. However, there were significant differences among the tested devices in the dorsal-plantar and in the eversion-inversion plane. In bipedal stance talar tilts were observed only when the foot was inverted more than 30 degrees. In unipedal stance these tilts were clearly reduced or disappeared totally. It is concluded that for functional rehabilitation, loading of the ankle joint is desirable in order to increase joint stability. The central importance of the treatment by orthotic devices may be regarded in an optimal passive joint stabilization combined with a correct fitting in order to preserve proprioceptive neuromuscular function for an active muscular stabilization.

[Novel functional studies of the stabilizing behavior of ankle joint ortheses]

For functional treatment of acute ankle sprain after surgical or nonsurgical management various special shoes and braces are in use. For a comparison under functional conditions we applied controlled inversion movements of 20 and 30 degrees to 13 subjects. The reduction of angular displacement was measured for the following orthosis: Aircast, Adimed Stabil 2, Adipromed Stabil Super, Mikros Ankle Brace, MHH-Splint Caligamed, Puschbrace and Tape. For evaluation of the neuromuscular activation surface EMGs of selected leg muscles were analyzed. A significant reduction of the induced inversion displacement was observed in all devices, although a complete inhibition of this movement was not possible. EMG activation was comparable to physiological conditions and is not correlated to the displacement characteristics. It is concluded that functional evaluation must take into consideration both the optimal reduction of the inversion and the high functional innervation.

Increased sensitivity of a Chinese hamster ovary cell line to alkylating agents after overexpression of the human metallothionein II-A gene

The elevation of intracellular levels of metallothionein has been associated with the development of resistance to the cytotoxic effects of some alkylating agents. In order to study the mechanisms underlying metallothionein associated drug resistance we transfected the alkylating agent sensitive CHO cell line MMC-1 (Robson et al., 1985) with an episomally replicating plasmid coding for the human metallothionein II-A gene. Two transfectants were isolated which carried about 10 copies of the plasmid. The basal expression of metallothionein was increased from undetectable levels in the recipient cell line MMC-1 to between 22 and 26 micrograms metallothionein per 10(7) cells in the transfectants. Treatment with cadmium salts increased metallothionein levels a further 1.7-fold. Cytotoxicity assays revealed that MTII-A transfection increased the sensitivity of the parental MMC-1 cells to N-methyl-N'-nitro-N-nitrosoguanidine and N-nitroso-N-methylurea. These results suggest that metallothionein does not act as a simple scavenger of alkylating agents, but interacts with unknown factor(s) in host cells.

[Rare causes and differential diagnoses of Achilles tendinitis]

Especially in sports disciplines involving high uniform stress by running, such as all running competitions in athletics, the condition known as achillodynia is a much-dreaded lesion. We evaluated an own series of 74 consecutive patients who reported pain at the achilles tendon, with regard to etiological aspects. It was a remarkable fact that besides the well-known classical reasons (degenerative changes in the center of the achilles tendon with spindle-shaped distension, aseptic irritated condition of the paratenon, bursitis subachillea mostly associated with Haglund's exostosis) numerous other syndromes may seem to be achilles tendon pain to individual athletes. To arrive at on-target therapy directed etiologically at the root cause of the disease, it will be necessary to differentiate them from one another: insertion tendopathies of the achilles tendon; metabolic diseases; arthritis and chondropathic disease of the ankle joint; hallux rigidus --rotation anomalies; tibia vara; os trigonum impingement syndrome --tendovaginitis of the flexor tendon at the retinaculum flexorum; stress fractures (calcaneus, fibula, tibia) Diagnosis is assisted, besides a detailed and exact clinical examination and an inspection of the sports shoes worn by the patient, by a biomechanical analysis of the running behaviour, an x-ray of the ankle joint, sonographic examination and clarification with the help of laboratory examinations, i.e. clinical pathology.

Purification and characterization of lipoamide dehydrogenase from Trypanosoma cruzi

From Trypanosoma cruzi, the causative agent of Chagas' disease, a lipoamide dehydrogenase was isolated. The enzyme, an FAD-cystine oxidoreductase, shares many physical and chemical properties with T. cruzi trypanothione reductase, the key enzyme of the parasite's thiol metabolism. 1. From 60 g epimastigotic T. cruzi cells, 2.7 mg lipoamide dehydrogenase was extracted. The flavoenzyme was purified 3000-fold to homogeneity with an overall yield of 26%. 2. The enzyme is a dimer with a subunit Mr of 55,000. With 1 mM lipoamide (Km approximately 5 mM) and 100 microM NADH (Km = 23 microM), the specific activity at pH 7.0 is 297 U/mg. 3. With excess NADH, the enzyme is reduced to the EH2.NADH complex and, by addition of lipoamide, it is reoxidized, indicating that it can cycle between the oxidized state E and the two-electron-reduced state, EH2. 4. As shown by N-terminal sequencing of the enzyme, 21 out of 30 positions are identical with those of pig heart and human liver lipoamide dehydrogenase. The sequenced section comprises the GGGPGG stretch, which represents the binding site for the pyrophosphate moiety of FAD. 5. After reduction of Eox to the two-electron-reduced state, the enzyme is specifically inhibited by the nitrosourea drug 1,3-bis(2-chloroethyl)-1-nitrosourea (Carmustine), presumably by carbamoylation at one of the nascent active-site thiols. 6. Polyclonal rabbit antibodies raised against T. cruzi lipoamide dehydrogenase and trypanothione reductase are specific for the respective enzyme, as shown by immunoblots of the pure proteins and of cell extracts.

Differential effects on cell killing in metallothionein overexpressing CHO mutant cell lines

An increased level of metallothionein (MT) within the cytosol has been associated with the development of resistance to the cytotoxic effects of alkylating agents, but the mechanism of this effect is unclear. To verify the possible role of MT as a direct scavenger of alkylating agents we transfected two alkylating agent sensitive CHO mutant cell lines, methyl methanesulphate-1 and -2 (MMS-1 and MMS-2), with the human metallothionein II-A (hMTII-A) gene. From each mutant two transfected cell clones were isolated which were found to bear episomally 50 to 70 copies of the plasmid pMTII-BPV coding for the hMTII-A gene. The transfected cell lines contained between 1.4 and 4.9 micrograms of MT per 10(7) cells. This could be increased 2- to 9-fold by heavy metal induction. Transfectants derived from mutant MMS-1 were equally sensitive as the parental cells to a set of alkylating agents. However, transfectants derived from mutant cell line MMS-2 gained significant resistance to both N-methyl-N'-nitro-N-nitrosoguanidine and N-nitroso-N-methylurea, whilst retaining sensitivity to MMS. The degree of resistance was not increased by MT induction after heavy metal ion exposure. These results indicate that although resistance to alkylating agents may be mediated by a process which involves MT expression, this is not due to simple scavenging of the cytotoxic agent by the MT protein.

Overexpressed human metallothionein IIA gene protects Chinese hamster ovary cells from killing by alkylating agents

Experiments were designed to detect survival advantages that cells gain by overexpressing metallothionein (MT). Chinese hamster ovary K1-2 cells and an x-ray-sensitive derivative were transfected with a bovine papillomavirus (BPV)-linked construct carrying the human metallothionein IIA (hMT-IIA) gene. Transfectants survived 40-fold higher levels of cadmium chloride, harbored at least 30 copies of hMT-IIA, and contained 25- to 166-fold more MT than the parent cells. Even under conditions of reduced glutathione synthesis, the transfectants were not more resistant to the lethal effects of ionizing radiation and bleomycin than the parent cells. Thus free radicals generated by these agents cannot be scavenged efficiently by MT in vivo. The hMT-IIA transfectants, however, but not control transfectants harboring a BPV-MT promoter-neo construct, tolerated significantly higher doses of the alkylating agents N-methyl-N-nitrosourea and N-methyl-N'-nitro-N-nitrosoguanidine. Resistance and MT overexpression occurred irrespective of selection and cultivation in cadmium and zinc. There was no increase in resistance to methyl methanesulfonate and N-hydroxyethyl-N-chloroethylnitrosourea. MT did not affect the degree of overall DNA methylation after N-methyl-N-nitrosourea treatment nor the level of O6-methylguanine-DNA methyltransferase. The results suggest that MT participates as a cofactor or regulatory element in repair or tolerance of toxic alkylation lesions.

Overexpression of metallothionein in CHO cells and its effect on cell killing by ionizing radiation and alkylating agents

Metallothionein protein protects cells from the toxic effects of heavy metal ions. To establish its protective function against ionizing radiation and alkylating agents, a model system was created by transfecting two CHO cell lines (wild-type, K1-2 and X-ray sensitive, xrs-2 subclone Bc11) with the human metallothionein II-A (hMTII-A) gene integrated in a bovine papilloma derived autonomously replicating vector. The isolated transfectants are cadmium-resistant (Cdr), due to the overexpression of the hMTII-A gene. Their steady-state level of hMTII-A mRNA can be increased up to 40-fold after Cd treatment and 20-fold after induction with ionizing radiation. The transfected cell lines proved to be as sensitive as the recipient cell lines to ionizing radiation and bleomycin but the transfectants were significantly more resistant to N-methyl-N'-nitro-N'-nitrosoguanidine (MNNG) and mitomycin C (MMC). These results lead to the conclusion that the MT protein does provide a defence mechanism to protect cells from monofunctional alkylating and cross-linking agents but not from free radicals.

[Design and effect of sports shoe insoles for the runner]

Running injuries of the lower extremities are more frequent with increasing intensity and extent of training. Biomechanical investigations demonstrate that exertion induced injuries of the foot, achillotendinitis, patellar tendinitis and shin splint syndrome are correlated with disorders in footstrike patterns. Therefore running shoe insoles can eliminate peak forces by exactly placing supporting elements. Furthermore peak forces may be distributed and complaints may be reduced. 50 runners with exertion induced injuries of the lower extremity were provided with appropriate running shoe insoles. There were excellent results in 34% and good results in 42%. 20% had moderate improvements while only 4% had unchanged complaints.

A promising genomic transfectant into Xeroderma pigmentosum group A with highly amplified mouse DNA and intermediate UV resistance turns revertant

Following transfection of genomic mouse DNA into an SV40 transformed fibroblast cell line from a patient with Xeroderma pigmentosum (complementation group A, XPA), a single UV resistant cell clone was isolated out of a total of 10(4) independent transfectants. The recipient XPA cell line has as yet not produced spontaneous revertants among 2.2 x 10(8) cells. The isolated cell clone contains 50-70 kb of mouse sequences which are heavily amplified (500-fold), and has acquired both intermediate resistance to UV killing and intermediate unscheduled DNA synthesis (UDS) capacity. By continued passage without selective pressure, cells were generated, which had lost both the dominant marker gene and repetitive mouse sequences. Single colonies of these cells were still intermediately resistant to UV suggesting that either undetected unique mouse DNA had segregated from the bulk of repetitive DNA, or, more likely, that the initially isolated transfectant was a spontaneous revertant. This documents that a persuasive clone isolated can still be a false positive (spontaneous revertant) and that an extremely laborious approach may lead into a dead end.

Ataxia telangiectasia resists gene cloning: an account of parameters determining gene transfer into human recipient cells

A subclone of an SV40-transformed fibroblast cell line from a patient with Ataxia telangiectasia (AT) with a relatively high rate of DNA uptake was isolated. However, more than 65000 independent genomic transfectants (using wild-type human DNA) did not contain the functional AT gene. This number represents the statistical distribution of an amount of DNA equivalent to more than three times the haploid human genome. The transfectants were screened by an X ray selection protocol that could rescue a single wild-type cell out of a population of 10(6) AT cells. This suggests a reversion frequency for AT of below 10(-8). The DNA uptake into human cells is compared with that into NIH3T3 cells and future possibilities for the isolation of human repair genes are discussed.

Double-strand break repair and G2 block in Chinese hamster ovary cells and their radiosensitive mutants

Two X-ray-sensitive mutants of the CHO K1 cell line were examined for their cell-cycle progression after irradiation with gamma-rays, and for their ability to rejoin double-strand breaks (DSBs) as detected by neutral filter elution. Both mutants were impaired in DSB rejoining and both were irreversibly blocked in the G2 phase of the cell cycle as determined by cytofluorometry. From one mutant we have isolated several revertants. The revertants stem from genomic DNA transfection experiments and may have been caused by gene uptake. All revertants survived gamma-irradiation as did the wild-type CHO line. One of them has been examined for its ability to rejoin DSBs and was found to be similar to the wild type.