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Biomedical subjects

M Macro

Publications and source records attributed to M Macro.

At least 37 records · Page 2Linked to original sources
PubMed1995

Modulation of interleukin-1 receptor expression by transforming growth factor-beta in cultured rabbit articular chondrocytes: analysis by reverse transcription-polymerase chain reaction.

Interleukin-1 receptor type I (IL-1RI) expression in cultured rabbit articular chondrocytes (RAC) was studied by reverse transcription-polymerase chain reaction (RT-PCR). A cDNA probe specific for the rabbit IL-1RI gene was constructed using primers derived from the sequence data of the human, murine and chick receptors. Transforming growth factor-beta 1 (TGF beta-1) was shown to transiently increase the level of expected 900-bp PCR product at 1 h of incubation and decrease the expression at 48 and 72 h with no effect at 24 h. In receptor binding assays using [125I]-IL-1 alpha, TGF beta decreased IL-1R bioactivity at all time points. These results suggest that TGF beta-induced down-regulation of IL-1 RI could be responsible for its ability to antagonize the effect of IL-1 and that TGF beta may have a role in the repair of articular cartilage.

Animals↗
PubMed1995

Human recombinant granulocyte-macrophage colony stimulating factor (hrGM-CSF) improves double hemibody irradiation (DHBI) tolerance in patients with stage III multiple myeloma: a pilot study.

Double hemibody irradiation (DHBI) is an alternative treatment of stage III multiple myeloma (MM) in patients aged over 55 years. Toxic side-effects such as myelosuppression are a severe limiting factor to its use. We performed DHBI associated with human recombinant granulocyte-macrophage colony stimulating factor (hrGM-CSF) as support therapy in 10 patients with stage III MM to improve the tolerance to this treatment. Ten patients received subcutaneously 5 micrograms/kg/d of hrGM-CSF during 2 weeks after each course of hemibody irradiation. All these patients had stage III MM: eight previously received chemotherapy, six of them were regarded as patients with refractory MM and two with relapse. Two patients received DHBI as first-line treatment. hrGM-CSF increased safety and tolerance of DHBI. GM-CSF support reduced the mean time between upper body irradiation (UBI) and lower body irradiation (LBI): 41 v 108 d in a cohort of 32 patients previously treated without growth factor support. Overall there was no lethal infection with hrGM-CSF or granulocytopenia (5.0 x 10(9)/l v 0.4 x 10(9)/l at day 15 in patients without growth factor). hrGM-CSF also reduced stomatitis grading and thrombocytopenia (90 x 10(9)/l v 45 x 10(9)/l at day 15). Furthermore, hrGM-CSF increased blood colony forming unit-granulocyte macrophage (CFU-GM) and was well tolerated in all but one patient. hrGM-CSF reduces toxic side-effects of DHBI, thus providing an effective treatment in patients with advanced and resistant MM.

Aged↗
PubMed1995

Modulation of rabbit articular chondrocyte (RAC) proliferation by TGF-beta isoforms.

We have previously shown that TGF-beta 1 exerts a bifunctional effect on RAC proliferation. Added to quiescent cultures, it inhibits the entry of G0/G1 cells into S phase whereas in S phase synchronized populations, it stimulates the DNA replication rate with a delayed G2 + M phase and a subsequent transient increase of cell number. As TGF-beta 2 and beta 3 isoforms are also expressed in bone and cartilage tissues, it was of interest to study their effect on RAC proliferation, in comparison to that of TGF-beta 1. Using cell counting and tritiated thymidine incorporation, we found that all the TGF-beta s used here induced an increase of RAC proliferation rate occurring between 24 and 48 h of exposure. TGF-beta 2 appeared as the most efficient form as judged from the maximum of thymidine labelling. However, TGF-beta 3 induced an increase of cell number slightly higher than both TGF-beta 1 and TGF-beta 2 (+30% versus 20% for TGF-beta 1 and beta 2). TGF-beta 2 and beta 3 were able to stimulate the DNA replication rate as previously demonstrated for TGF-beta 1. However, the effect occurred later for TGF-beta 2 and beta 3 (12 h) than for TGF-beta 1 (6 h). This was confirmed by flow cytometric analysis of DNA content. In addition, immunodetection by flow cytometry demonstrated that all TGF-beta isoforms enhanced endogenous expression of TGF-beta-related peptides. The effect was shown to be associated with the cell cycle S phase and was greater for TGF-beta 3 than for TGF-beta 1 and beta 2. These findings suggest that TGF-beta s could act on RAC functions via autocrine and paracrine ways. Taken together, these data indicate that TGF-beta s may modulate proliferation of articular chondrocytes and therefore could play a role in the activation of these cells in the early stages of osteoarthritis.

Animals↗
PubMed1995

Intravenous aminohydroxypropylidene bisphosphonate does not modify 99mTc-hydroxymethylene bisphosphonate bone scintigraphy. A prospective study.

Bisphosphonates have marked affinity for bone that makes them useful in both the treatment and imaging of bone lesions. Bone scintigraphy is very sensitive for the detection of bone metastases, which can cause life-threatening hypercalcemia requiring emergency treatment. This prospective study was done to determine whether intravenous administration of pamidronate, a second-generation bisphosphonate used to treat hypercalcemia, affects the affinity of the radiopharmaceutical 99m technetium-labeled hydroxymethylene bisphosphonate (99mTc-HMDP) for bone and bone lesions. Six patients with metastatic bone disease and five with Paget's disease of bone had a 99mTc-HMDP bone scan before and two to four days after an intravenous infusion of pamidronate. The number and activity of metastatic bone lesions were unchanged after pamidronate, even when the second bone scan was done only 24 hours after the pamidronate infusion. Our data suggest that emergency treatment of life-threatening hypercalcemia by intravenous pamidronate does not decrease the sensitivity of subsequent bone scanning done to detect bone metastases.

Aged↗
PubMed1994

Transforming growth factor-beta (TGF-beta) and articular chondrocytes.

Transforming growth factor-beta (TGF-beta) has a dual effect on the proliferation of joint chondrocytes. In medium with a low serum concentration, it inhibits cell growth, while in medium supplemented with 10% fetal calf serum it stimulates cell growth. This stimulation leads to a higher replication rate an a larger number of cells in the G2/M phase of the cell cycle. Since these cells have already replicated their DNA, they can begin mitosis when stimulated by a EGF type factor. This mechanism involves the systems of the TGF-beta receptors which appear to vary with the cell cycle. In addition, a glycane inositophosphate may play a role as a second messenger for TGG-beta in this action. Finally, TGF-beta cannot restore the chondrocyte phenotype in dedifferentiated cells nor limit the dedifferentiation process. It exerts a opposing effect to the deleterious effects of interleukin-1 by inhibiting the expression of the receptors of this cytokine at the level of transcription. These in vitro effects would suggest that TGF-beta plays an important role in the repair potentiality of joint cartilage especially in arthrosis. In vivo studies are however necessary to verify this hypothesis.

Animals↗
PubMed1993

[Psoriatic onycho-pachydermo-periostitis].

Psoriatic-onycho-pachydermo-periostitis is a particular form of psoriatic arthropathy recently described, which combine psoriatic onychosis, thickening of the distal soft tissues and osteo-periostitis of the distal phalanx without lesion of the interphalangeal joint. Biological examinations are normal. Radiological lesions show a phalanx condensation which gives a spicule aspect. Two cases of onycho-pachydermo-periostitis are described. We report the first one with all the fingers and toes concerned.

Acrodermatitis↗
PubMed1992

[Polyarthritis revealing hairy cell leukemia].

A female patient simultaneously developed hematologic evidence of hairy cell leukemia and marked but short-lived inflammatory involvement of a number of joints. Both these groups of symptoms resolved simultaneously and rapidly under alpha-2 interferon therapy. This course suggests that the arthritis was a rheumatologic manifestation of the hematologic disease. The concomitant occurrence in this patient of arthritis, splenomegaly and leukopenia was suggestive of Felty syndrome: these two conditions need to be differentiated.

Adult↗
PubMed1989

[Congestive outbreaks of osteo-arthrosis].

Osteo-arthritis is often interspersed with congestive episodes due to inflammation of the synovial membranes, the vascular component of which is more important than the cellular component. This explains why the clinical signs of inflammation are moderate and characterized mainly by a mechanical-type formula. The mechanism of these episodes involves several factors, and osteo-cartilaginous fragments, microcrystals and perhaps immune complexes have been blamed for their occurrence. The influence of inflammation on cartilage degradation has been proved experimentally, and this is supported by some clinical findings. Treatment consists of non-steroidal anti-inflammatory agents, intra-articular corticosteroid injections and relief of articular overload.

Humans↗
PubMed1988

Hemibody irradiation in stage III multiple myeloma: results of 20 patients.

The advanced forms of multiple myeloma of bone, stage III, or those with a large tumoral mass, characterized by a considerable number of myeloma-cells, pose difficult problems in treatment. Little progress has been made since the introduction of the alkylating agents, and combined chemotherapy does not seem to be any more effective in terms of survival. It is these severe forms that culminate in painful symptoms which are often difficult to eliminate. The radiosensitivity of myeloma led us to treat 20 patients affected by severe forms of the disease by total body irradiation in two stages, and we analyse here the effects of treatment and the tolerance for this technique.

Female↗