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J Gielen

Publications and source records attributed to J Gielen.

At least 73 records · Page 4Linked to original sources
PubMed1994

[Tamoxifen in the treatment of breast cancer].

Tamoxifen is the most often prescribed non steroidal antioestrogenic agent in the world for breast cancer. Worldwide collaboration. has centralized the results, of different trials throughout the world on oral adjuvant therapy in the early stages of breast cancer. A significative regression of the tumour was observed in most cases. Moreover, recent epidemiological studies suggest that tamoxifen could prevent new contralateral primary tumours. The risk of the disease should thus be reduced by the prophylactic use of antioestrogens such as tamoxifen. Investigations using a variety of models have evaluated the effect of tamoxifen on tumour promotion and cell growth. Tamoxifen-induced growth inhibition is associated with major changes in biochemical events in cultured human breast cancer cells including cell proliferation or growth factor production. Growth inhibition of oestrogen-responsive human breast cancer cells is associated with an induced secretion of autoinhibitory polypeptides (TGF beta) and an antagonistic effect on the synthesis of proliferative proteins (TGF alpha,...). The first step in the mechanism of action of the drug is binding of tamoxifen to the oestrogen receptors. Development of resistance to tamoxifen treatment is a great problem in treatment of breast cancer patients and the mechanism of resistance will require further study: under the influence of the drug, tumours could become remodelled as selected subpopulations emerge resistant-tamoxifen. The fact that some breast cancers which are oestrogen receptor-negative respond to antioestrogen suggests that parallel but separate pathways for oestrogen and antioestrogen action may exist. This paper summarizes the results of the most recent studies concerning this promising drug.

Breast Neoplasms↗
PubMed1992

[The role of CT in diagnosis and therapy of fractures of the pelvic girdle].

The conventional pelvic overview and special projections of the pelvic ring are often not conclusive for the diagnosis of pelvic ring fractures. The superimposition of multiple bony and soft tissue structures interfere with correct three-dimensional orientation of the bony lesions in spite of special projections. CT offers the possibility of identifying pelvic fractures that are not visible in conventional radiographs. Dislocated fractures can especially be appreciated. With CT, it was possible for the first time to classify lesions of the sacroiliac joint: (I) distortion (vacuum phenomena), (II) rupture of the ventral sacroiliac ligaments (open book), (III) lesions of the ventral and dorsal sacroiliac ligaments, and (IV) luxation of the os sacrum. Lesions of the sacrum can also be classified into four groups: (I) diastasis of the sacroiliac joint, (II) sacral lip fractures, (III) vertical fractures and compression fractures, (IV) comminuted fractures. Above all, the CT scan facilitates an accurate examination of the dorsal pelvic ring. Furthermore, better appreciation of intrapelvic soft tissue lesions is possible. In a retrospective study on 53 patients, in 88.7% we had quite helpful and extremely helpful CT examinations, and 90% higher precision in comparison to conventional radiographs.

Female↗
PubMed1991

Tomato alcohol dehydrogenase. Expression during fruit ripening and under hypoxic conditions.

We have isolated and sequenced a partial tomato alcohol dehydrogenase (Adh) cDNA clone. Expression of tomato Adh was studied at the messenger RNA level in seedlings, roots, and fruit. High induction was observed under hypoxic conditions, both in tomato seedlings and in roots. In addition, the Adh mRNA was present at the mature green and pink stage of the tomato fruit, and was highly induced in late ripening. Moreover, an artificial ripening treatment resulted in at least 50-fold induction compared to the mature green mRNA level. Genomic DNA gel blotting suggested the presence of a multigene family for Adh in tomato.

Alcohol Dehydrogenase↗
PubMed1991

The extensin signal peptide allows secretion of a heterologous protein from protoplasts.

Extensins are hydroxyproline-rich glycoproteins which are amongst the most abundant proteins present in the cell wall of higher plants. Here, we describe the structural analysis of an extensin-encoding gene from Nicotiana plumbaginifolia. The encoded protein (46 kDa) has a highly repetitive structure and contains 37% proline, 18.1% tyrosine, 13.4% lysine, 8.1% serine and 7.1% histidine. The extensin-encoding sequence contains a typical signal peptide for translocation of the protein to the endoplasmic reticulum. By using chimeric genes consisting of different 5' parts of the extensin-encoding gene and the neomycin phosphotransferase II-encoding gene (nptII) as reporter gene, we show that the N-terminal part of extensin can mediate the secretion of NPTII from electroporated N. tabacum protoplasts.

Amino Acid Sequence↗
PubMed1991

Non-linear increase in vertebral density induced by a synthetic steroid (Org OD 14) in women with established osteoporosis.

The results of a 2-year placebo-controlled study in 38 female patients with osteoporosis are presented. This study was conducted to evaluate the efficacy of a daily oral dose of 2.5 mg Org OD 14 ((7 alpha, 17 alpha)-17-hydroxy-7-methyl-19-norpregn-5(10)-en-20-yn-3-one) in the treatment of established osteoporosis. Org OD 14 is a steroid which shows combined weak oestrogenic, androgenic and progestational activity. A total of 31 patients completed a 12-month study period (17 placebo, 14 Org OD 14) and 25 of these went on to complete the full 24-months (15 placebo, 10 Org OD 14). A significant increase in bone mineral density as measured by dual photon absorptiometry was recorded in the lumbar spine in the Org OD 14-treated patients at 8, 16 and 24 months. The gain in bone mass after 8 months averaged 4% (P less than 0.01) and after 24 months 8% (P less than 0.001). In the control group, a bone loss rate of 2% per year was recorded in the lumbar spine. No significant changes in bone density in the forearm as assessed by single photon absorptiometry were found in either group. The increase in spinal bone density in the Org OD 14 group was non-linear and followed an S-shaped upward pattern. Org OD 14, while inducing no appreciable endometrial stimulation, was found to be a bone-active compound with anti-resorbing as well as anabolic activity. Org OD 14 warrants consideration not only for the long-term prevention of bone loss but also for curative treatment of post-menopausal osteoporosis.

Absorptiometry, Photon↗
PubMed1991

Correlation between magnetic resonance imaging and arthroscopy in the diagnosis of anterior cruciate ligament and meniscus lesions.

In both radiological and orthopedic journals the value of MRI for diagnosing internal derangement of the knee has been assessed recently. However, results vary widely and no study reports on the differentiation among types of ACL tears. As far as meniscal pathology is concerned, attention has been drawn by Reicher et al. (11) and Glashow et al. (5) upon the false positive tears of the posterior horn of the medial meniscus. Where most authors consider signal inversion in the posterior horn of the meniscus as a normal finding in children--due to the higher water content--the same fact in adults can be interpreted as a false positive image or a missed tear at arthroscopy (5).

Adolescent↗
PubMed1990

Cloning and sequence analysis of truncated T-DNA inserts from Nicotiana tabacum.

Transgenic plants produced by Agrobacterium-mediated transformation usually have one or a few stable and intact T-DNA insertions. However, in a significant number of the transformants Southern blot analysis has revealed the occurrence of aberrant T-DNA insertions missing one or both ends. During the study of this phenomenon, we obtained KmR Nicotiana tabacum clones after cocultivation with an Agrobacterium strain containing a promoterless nptII gene located internally in the T-DNA. Expression of this nptII gene requires a break in the T-DNA region upstream from the nptII-coding sequence and insertion of the truncated T-DNA in a transcriptionally active plant DNA region. The most conspicuous result from Southern analyses on four such KmR plant clones is that they contain several T-DNAs truncated at other positions besides the upstream region of the nptII sequence. Four truncated T-DNA insertions have been cloned. Two insertions contain the nptII gene fused to plant expression signals and are missing the right part of the T-DNA. Another is missing the left T-DNA part and the last T-DNA is lacking both ends. Sequence analysis of the T-DNA::plant junctions has shown that the T-DNA breakpoints are randomly distributed and do not show obvious homologies to one another or to the border consensus sequence. S1-type mapping of the most strongly expressed plant genome::nptII fusion revealed a specific transcription start point and putative TATA and CAAT boxes in the upstream plant DNA region; the steady-state nptII mRNA in these plants is about 20 times more abundant than in transgenic Pnos-nptII plants.

Base Sequence↗
PubMed1989

Soft tissue involvement, mediastinal pseudotumor, and venous thrombosis in pustulotic arthro-osteitis. A study of eight new cases.

A syndrome of hyperostosis of the thoracic wall, nonspecific signs of inflammatory disease, and palmar and plantar pustulosis is described in eight patients (Table 1). Seven had intersternocostoclavicular ossification, and one had chronic recurrent multifocal osteomyelitis. This complex of findings has been called "pustulotic arthro-osteitis". This report emphasizes the periosseous soft tissue inflammation and the unexplained subclavian and mediastinal vein thrombosis seen in two patients. Inflammatory periosseous and mediastinal lesions were seen on plain films in all eight patients and on computed tomographic (CT) scans in seven. Radiographs of the spine showed a spondyloarthropathy in three patients. This was characterized by ossification of the vertebral ligaments and sclerosis of the vertebral bodies. Awareness of the radiologic features of pustulotic arthro-osteitis is important because the clinical, biochemical and pathologic findings are often nonspecific and misleading.

Adult↗
PubMed1989

Intrinsic problems with the external fixation device of Hoffmann-Vidal-Adrey: a critical evaluation of 117 patients with complex tibial shaft fractures.

In the 1978-1986 period, 117 patients with 119 fresh and complex fractures of the lower leg were secured primarily with a Hoffmann-Vidal-Adrey external fixation device. Ninety-five fractures could be followed until bony consolidation. In 12 fractures (12.7%) a pseudarthrosis developed, and a deep infection in four (4.2%). The external fixation device was attached for an average time of 25.0 weeks. Pin loosening was seen in seven patients (7.3%), minor pin-tract infection in nine (9.4%), and major pin-tract infection in three patients (3.1%). Fourteen fractures needed a secondary internal fixation; in 17 other fractures a secondary transplantation of cancellous bone autografts without internal fixation was carried out. After healing of the soft tissues, the tibial fracture can be regarded as a closed one and other therapeutic procedures to accelerate bony consolidation should be taken into account. The advantages and disadvantages of a second internal stabilization should be evaluated for every fracture with bone healing problems. The alteration from external to internal fixation makes an early removal of the external fixator possible and prevents in this way the intrinsic problems combined with this fixation type such as delayed union, nonunion, pin loosening, or pin-tract infection.

Adolescent↗
PubMed1989

Induction of liver microsomal cytochrome P-450 isozymes by 1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinoline carboxamide.

1. 1-(2-Chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinoline carboxamide (RP 52028), an antagonist of peripheral type benzodiazepine binding sites, a potential anticonvulsant, has been shown to have an inducing effect on drug-metabolizing enzymes. 2. RP 52028 was administered orally at 20-800 mg/kg for 1 week, and enzymic activities were determined using a panel of substrates. Western blot analyses were performed using several specific polyclonal and monoclonal antibodies directed against cytochrome P-450 isozymes. 3. RP 52028 appears to be an inducer of cytochrome P-450 II B1 (P-450b) and related enzymic activities; i.e. benzphetamine, ethylmorphine and aminopyrine demethylation.

Animals↗
PubMed1988

Primary structure of a hormonally regulated beta-glucanase of Nicotiana plumbaginifolia.

A cDNA clone for a hormonally regulated beta-glucanase from Nicotiana plumbaginifolia has been isolated by using an oligodeoxynucleotide probe, synthesized to match the previously determined N-terminal amino acid sequence. The cDNA has the complete sequence of the mature protein and contains at least part of a hydrophobic signal peptide. At the amino acid level, the beta-glucanase of N. plumbaginifolia is 73% homologous to a beta(1,3)-glucanase from tobacco and 52% homologous to a beta(1,3;1,4)-glucanase from barley. Southern-blot analysis clearly demonstrated that N. plumbaginifolia contains at least two related genes encoding beta-glucanase. The extent of the complete signal peptide of the cloned beta-glucanase was determined by sequencing part of the corresponding gene. Northern analysis showed that the expression of the beta-glucanase gene is influenced by auxins and cytokinins.

Amino Acid Sequence↗
PubMed1988

Characterization of highly repetitive sequences of Arabidopsis thaliana.

We have analyzed three classes of highly repetitive DNA sequences of Arabidopsis thaliana, composed of tamdemly repeated units of 180 bp, 500 bp, and 160 bp, respectively. The three families comprise approximately 2% of the Arabidopsis genome and are the major component of the highly repetitive DNA. The 500-bp element arose by duplication of one half of a 180-bp ancestor and insertion of a foreign segment between the two duplicated parts followed by amplification. The repeat elements contain occasionally palindromes and other motifs but none are significantly conserved. There is no significant similarity with previously published repetitive elements. Heterogeneity between monomers ranges from 6% to 17%. Monomers derived from different clusters in the genome are more diverged than monomers of the same array.

Base Sequence↗
PubMed1988

Staging and follow-up of rheumatoid arthritis of the knee. Comparison of sonography, thermography, and clinical assessment.

Twenty patients with longstanding polyarticular rheumatoid arthritis (including knee involvement) were selected for this study. The severity of the knee synovitis was assessed before and during treatment (with intra-articular corticosteroid injections) using clinical scores, sonography, and thermography. In all patients, the inflammation regressed during treatment. During follow-up, the quantity of synovial fluid, as measured sonographically 10 days after the start of therapy, correlated best with the clinical status. Maximal regression of synovial thickening was noted on delayed sonograms performed three months after treatment. Thermographic peak temperature showed good correlation with the clinical status, but the thermographic index was unreliable.

Adrenal Cortex Hormones↗