PubMed Health⌕ Search

Biomedical subjects

H Lohrer

Publications and source records attributed to H Lohrer.

At least 19 recordsLinked to original sources
PubMed2006

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.

Adolescent↗
PubMed2006

[Flexor hallucis longus tendon rupture as an impingement lesion induced by os trigonum instability].

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.

Adult↗
PubMed2004

[Combined lateral ankle and calcaneocuboid joint instability].

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.

Adult↗
PubMed2003

[Impingement lesion of the distal anterior Achilles tendon in sub-Achilles bursitis and Haglund-pseudoexostosis-a therapeutic challenge].

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.

Achilles Tendon↗
PubMed2002

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.

Cell Division↗
PubMed2001

[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.

Adolescent↗
PubMed2001

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.

Adult↗
PubMed1999

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.

Adhesives↗
PubMed1998

[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.

Adolescent↗
PubMed1996

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.

Antineoplastic Agents↗
PubMed1995

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.

Ataxia Telangiectasia↗
PubMed1994

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.

Alkylating Agents↗
PubMed1993

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.

Achilles Tendon↗
PubMed1993

[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.

Ankle Injuries↗
PubMed1992

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.

Alkylating Agents↗