PubMed Health⌕ Search

Biomedical subjects

R Löfvenberg

Publications and source records attributed to R Löfvenberg.

14 recordsLinked to original sources
PubMed1999

Clinical course in synovial sarcoma: a Scandinavian sarcoma group study of 104 patients.

We analyzed treatment and outcome in 104 Scandinavian patients with synovial sarcoma in the extremities or trunk wall, diagnosed between 1986 and 1994. Only surgically treated patients without metastases at diagnosis were included. Median follow-up of survivors was 6 (3-11) years. 34 patients developed metastases. The overall 5- and 7-year survival rates were 0.76 (95% CI 0.66-0.83) and 0.69 (0.58-0.78), respectively. Large tumor size and amputation were significantly associated with impaired metastasis-free survival. Patients with local recurrence had a higher risk of metastases following the local event. Local excision with inadequate margin was associated with a higher risk of local recurrence.

Adolescent↗
PubMed1997

A novel spontaneous metastasis model of human osteosarcoma developed using orthotopic transplantation of intact tumor tissue into tibia of nude mice.

Evaluation of potential new treatment strategies requires adequate experimental tumor models which resemble the clinical situation as closely as possible. The purpose of the present study was to establish a new human osteosarcoma spontaneous metastasis model using orthotopic transplantation of histologically intact tumor tissue into the tibia of nude mice. Intact tumor pieces, obtained from the 32nd serial passage of subcutaneously growing human osteosarcoma xenografts, were implanted into the proximal tibia in 31 nude mice. Animals were sacrificed and autopsied 2, 4, 6, and 8 weeks after transplantation and examined macroscopically and microscopically for local tumor growth and metastases. All mice developed local intratibial bone tumors that were radiographically and histologically similar to primary human osteosarcoma. Lung metastases were observed in all mice, local and distant lymph node metastases in 15 (48%), and liver metastases in 6 (19%) mice. The microscopic appearance of the metastases was similar to that observed in the donor patient's tumor, corresponding subcutaneous xenografts and orthotopically transplanted intratibial tumors. This spontaneous metastasis model of human osteosarcoma in nude mice may resemble a clinical situation and could thus be useful for studies on local tumor growth, metastasis formation and therapy.

Animals↗
PubMed1996

Growth patterns and cell kinetics of human osteosarcoma xenografts in serial passages in nude mice analyzed by in vivo labelling with iododeoxyuridine.

A human osteoblastic osteosarcoma was transplanted in nude mice and followed in seven serial passages. Tumor cell kinetics was analyzed by in vivo labelling with the thymidine analogue iododeoxyuridine (IdUrd). Immunohistochemistry was used to measure the IdUrd labelling index. Duration of S phase (ts) was estimated by flow cytometry. From these two parameters potential doubling time (tpot) was calculated. Cell kinetic parameters showed low variations between passages and also between xenografts in same passage. Smaller variations of ts compared to labelling index and tpot were found. tpot was generally short with an interpassageal mean of 1.3 days and CV=14.8%. All xenografts showed DNA aneuploidy (mean DNA index --1.6). Homogeneous tumor growth was indicated by low variations of volume doubling time and lag time. There was no correlation between tumor growth and cell proliferation. Histopathological characteristics of the donor patients tumor were retained during serial transplantation.

Animals↗
PubMed1996

[Proprioceptive reaction in the healthy and chronically unstable ankle joint].

Chronic lateral instability of the ankle, a condition with frequent ankle sprain episodes, difficulties to walk and run on uneven ground and often pain, occurs in 20-30% after acute ankle sprains. The treatment of CLI as well as of acute ankle sprains have more and more in addition to operative reconstructions been focused on proprioceptive training which is in concordance with the results of recent research results. The present study shows that the reaction time after sudden angular displacement of the ankle on a trapdoor is increased by approximately 15 ms in patients with chronic lateral instability compared to control persons. We conclude that delayed proprioceptive response to sudden angular displacement of the ankle can be one of the causes to chronic lateral instability of the ankle and that proprioceptive training should be included in the treatment of acute and chronic ankle disabilities.

Adult↗
PubMed1996

Antagonistic effect of amphotericin B on carboplatin antitumor activity in human osteosarcoma xenografts.

Amphotericin B (AmB), a polyene antifungal antibiotic, has been shown to potentiate the cytotoxic effect of different chemotherapeutic drugs in vivo and in vitro. The purpose of this study was to determine whether AmB could enhance the carboplatin antitumor activity in a human osteosarcoma xenograft model. Nude mice, bearing s.c. transplanted osteosarcoma xenografts, received i.p. an injection of AmB (5 mg/kg) 6 h prior to carboplatin (20 mg/kg) or each of the drugs separately. The effect of treatment was assessed by analyzing tumor growth delay and T/C ratio. Carboplatin clearly reduced tumor growth when administered alone. However, an unexpected interaction was seen where AmB significantly decreased the antitumor effect of carboplatin. The present results contradict some earlier in vitro studies and indicate the complexity of this interaction in vivo. Hence, it seems that interactive phenomena in one experimental model, and especially with regard to AmB, cannot be universally applied to all experimental situations.

Amphotericin B↗
PubMed1996

Structure, growth and cell proliferation of human osteosarcoma and malignant fibrous histiocytoma xenografts in serial transplantation in nude mice.

Tumour specimens from one patient with osteosarcoma and one with malignant fibrous histiocytoma were transplanted in serial passages in nude mice. Structure, growth and cell kinetics of the xenografts were studied in order to assess the validity of the two tumour models. Cell proliferation was analysed using in vivo labelling with the thymidine analogue iododeoxyuridine (IdUrd) and the IdUrd labelling index (LI) was determined by immunohistochemistry. The DNA index (DI) was examined by flow cytometry. The c-myc oncoprotein expression was studied by immunohistochemistry. More intense proliferation was observed in the peripheral parts of the tumours. There was no correlation between tumour growth and cell proliferation in the two tumour groups. Stability of the tumour models was indicated by low intrapassage and interpassage variations of DI, LI, and volume doubling time, and also by retained histopathological characteristics and c-myc staining patterns of donor patients' tumours during serial transplantation.

Aged↗
PubMed1994

The outcome of nonoperated patients with chronic lateral instability of the ankle: a 20-year follow-up study.

Thirty-seven patients conservatively treated because of chronic lateral instability of the ankle were studied 18 to 23 years after their index visit. Twenty-two patients, 12 with unilateral and 10 with bilateral symptoms (32 of 49 ankles), still suffered from instability, but only three considered further treatment. Degenerative changes were observed in six of 46 radiographically examined ankles, with no correlation to age or persistent instability.

Adolescent↗
PubMed1994

Ligament reconstruction for ankle instability. A 5-year prospective RSA follow-up of 30 cases.

30 ankles in 27 patients operated on for chronic lateral instability with tensioning of the lateral ligaments and capsular tissue were examined using RSA preoperatively, at 20 and 60 months. 28 ankles were considered excellent or improved by the patients. Mechanical stability (talar adduction and translation) was increased without compromising the passive range of motions.

Adolescent↗
PubMed1990

Fibular mobility in chronic lateral instability of the ankle.

Using roentgen stereophotogrammetric analysis we recorded the mobility of the lateral malleolus under maximum passive plantarflexion and dorsiflexion and during the anterior drawer and the adduction tests in 29 patients with chronic lateral instability of the ankle. Medial and anterior displacements were observed during plantarflexion, at the adduction test and at the posterior loading of the tibia. At dorsiflexion we recorded posterior fibular shifts. The simultaneously occurring fibular rotations were small. Chronic lateral instability of the ankle was associated with slightly increased fibular movements during plantarflexion and dorsiflexion, and at the adduction test in some patients with bilateral symptoms, perhaps reflecting a generalized joint laxity.

Adolescent↗
PubMed1990

A case of occipitocervical fusion in myeloma.

Posterior fusion (from occiput to C4) with an iliac graft on the right side and methyl methacrylate on the left side was performed in a 49-year-old woman with an osteolytic destruction of the second vertebral body caused by multiple myeloma. Thirty months after the fusion, the patient remains free from pain, although there is progression of the osteolytic lesion, now extending to the third vertebral body.

Cervical Vertebrae↗
PubMed1989

Chronic lateral instability of the ankle. Roentgen stereophotogrammetry of talar position.

Using roentgen stereophotogrammetric analysis (RSA), we investigated the talar mobility in 54 ankles during the anterior drawer and adduction tests. Talar tilt was increased in ankles with unilateral symptoms of chronic lateral instability. No other difference in talar tilt and anterior drawer sign was noted comparing ankles with and without symptoms. We conclude that mechanical tests cannot always verify the diagnosis "chronic lateral instability of the ankle".

Adolescent↗
PubMedDate not supplied

The influence of an ankle orthosis on the talar and calcaneal motions in chronic lateral instability of the ankle. A stereophotogrammetric analysis.

The mechanical support provided by a semirigid ankle orthosis was tested in 14 ankles with symptoms of chronic lateral instability by use of stereophotogrammetric analysis. Talar and calcaneal rotations were measured with and without the Strong ankle orthosis during manual adduction test and adduction test with a predetermined torque (5 N-m). Significant reduction of talar and calcaneal plantar flexion, internal rotation, and varus angulation was noted when the orthosis was applied. The results of this study suggest that the semirigid orthosis may provide enough external support to prevent ankle sprains and to protect ligament reconstructions.

Adult↗
PubMedDate not supplied

Prolonged reaction time in patients with chronic lateral instability of the ankle.

Impaired proprioception has been suggested as one cause of chronic lateral instability of the ankle. We subjected 15 ankles in 13 patients with symptoms of chronic lateral instability to sudden angular displacement. The reaction times in the peroneus longus and the tibialis anterior muscles were recorded and compared with those from 15 control ankles. Significantly longer ipsilateral reaction time was recorded in the patients (65 ms) compared with the controls (49 ms). We concluded that delayed proprioceptive response to sudden angular displacement of the ankle may predispose an individual to or be a cause of chronic lateral instability of the ankle.

Adult↗