Biomedical subjects
Publications and source records attributed to M Hoogmartens.
Cytogenetic analysis of a rare adipose tissue tumor, hibernoma, a benign proliferation of the brown fat, is presented for the first time. A complex translocation involving bands 1p36, 2q33, 5q22, and 11q13 was found as the sole chromosome abnormality.
Different derivatives of MAG, carrying amino acids such as D- or L-alanine, D-serine, D-2-aminobutyric acid, D-valine or D-phenylglycine were synthesized and their 99mTc-complexes were evaluated in mice and a baboon. The efficiency of renal handling of the examined 99mTc-complexes is influenced not only by their lipophilicity but also to a great extent by their configuration and the site of substitution. The renal excretion characteristics of 99mTc-MAGAG-DA are superior to those of 99mTc-MAG3 and the studied 99mTc-complexes in both animal species. In an attempt to improve the renal handling of 99mTc-MAG3 and to evaluate the effect of derivatization we have synthesized different derivatives of MAG3 in which one or more glycyl groups are replaced by other amino acids such as D- or L-alanine, D-serine, D-2-aminobutyric acid, D-valine or D-phenylglycine. Due to the presence of a chiral centre in the ligand core, exchange labelling of each of the MAG3 derivatives results in the formation of two diastereomeric technetium complexes. These isomers were separated by HPLC and evaluated in mice. Biodistribution in mice indicates that the efficiency of renal handling of the examined 99mTc-complexes is not only influenced by their lipophilicity but also to a great extent by their configuration. The renal excretion characteristics of isomer DA of 99mTc-MAGAG in mice are superior to those of all other studied 99mTc-complexes and also of the reference compound [131I]Hippuran. The isomers LB of several alanyl derivatives of 99mTc-MAG3 exhibit a pronounced renal retention in both mice and baboon. The results of the evaluation in a baboon confirm the superiority of 99mTc-MAGAG-DA over 99mTc-MAG3 and the other studied 99mTc-complexes.
Sixty-two tibial diaphyseal nonunions in 60 patients were treated with a posterolateral bone graft over an 18-year period (1969-1987). The majority were complicated by severe soft tissue damage or segmental bone loss. Thirty-four had a deep infection. Primary healing was achieved in 92%. Three types of bone grafts have been used: from 1969 to 1978 either a whole iliac bone graft (10 tibiae) or a nonvascularized fibular graft (11 tibiae) was used. Since 1978 small iliac cancellous bone chips (41 remaining tibiae) were applied to the posterior surfaces of tibia and interosseous membrane. In three tibiae with major bone defects, cancellous allografts were added to the autogenous bone. The use of cortico-cancellous bone chips resulted in a shorter healing time, compared to a nonvascularized fibular graft or a massive corticocancellous bone block.
A clinical analysis of 8 patients with brachial plexus neuropathy is presented. The disease may involve the upper, the lower, or the entire plexus. There is a higher incidence in men than in women. The syndrome is not uncommon but is frequently diagnosed incorrectly. The fairly typical pattern of symptoms and signs includes sudden onset with severe pain along one side of the shoulder girdle, followed in a few hours or days by atrophic paralysis of muscles over the affected shoulder. The disorder is occasionally bilateral. The paresis persists for months or even years. The overall prognosis is excellent despite the severity and extent of the lesion. The etiology is unknown, but decreased physical resistance is a predisposing factor.
In this series spondylolisthesis was treated operatively in children and adolescents who had a displacement greater than 50% even if they were asymptomatic. In youngsters with less than 50% displacement and in adults, operative stabilization was performed if the displacement was progressive or if there were persistent symptoms unresponsive to conservative treatment that interfered with the patient's normal activities. The operation consisted of a posterolateral fusion in situ. Usually a laminectomy was not performed unless there were signs of severe neural compression. No reduction of the spondylolisthesis was attempted. We reviewed 38 cases treated operatively with a mean follow-up of 7 years. Twenty patients were younger than 20 years at the time of operation and 10 of these had greater than 50% displacement. The results were good to excellent in 90% (18 patients). In the adult group (18 cases) the results were less favorable, but still good to excellent in 72% (13 patients). In the adult group pseudarthrosis frequently occurred at the L4-L5 level. There were no neurologic complications postoperatively. Fusion in situ for spondylolisthesis is a safe operation giving satisfactory results.
The authors describe a semiconservative approach for bilateral fracture-dislocation of the sacrum, an extremely rare injury. Traction is advocated; it seems to lead to a good functional result after 20 years. Other authors either propose internal fixation or benign neglect, also with a good outcome. Every case must be approached on an individual base.
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To study the differences in biological behaviour between the four stereoisomers of 99mTc-CO2-DADS we synthesized both the L- and D-isomer of N,N'-bis-(benzoylmercaptoacetyl)-2,3-diaminopropanoic acid ethyl ester. The N2S2 ligands were labelled with 99mTc by the dithionite reduction method in alkaline medium to hydrolyze the ester function. Each isomer yielded two diastereomeric 99mTc-complexes, that were separated by RP-HPLC to finally obtain the four isomers of 99mTc-CO2-DADS. The biodistribution of the isomers was determined in mice and a baboon. The study in mice indicates that only the LB-isomer is responsible for the high liver uptake reported for (DL)-99mTc-CO2-DADS-B (Fritzberg et al. J. Nucl. Med. 23, 592-598, 1982). The rate of renal extraction and hepatobiliary excretion of the three other isomers is comparable to that of [131I]o-I-hippurate. Baboon renograms for the LA- and DA-isomers are similar to that of [123I]o-I-hippurate. The renogram of the DB-isomer resembles more the 99mTc-DTPA renogram, whereas the LB-isomer exhibits a 99mTc-DMSA-like renal build-up. It appears that minor configurational changes can drastically alter the renal handling of these bisamide bisthiol 99mTc-tracer agents.
The fixation of segmental, distal third and comminuted femoral and tibial fractures by means of an interlocking nail is widely accepted now. A simple self-built target device allows easy placement of the distal transverse screws.
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.
A rat model was used to study renal function after unilateral kidney irradiations. The left kidney was irradiated with a single dose (6-14 Gy), 2 equal sized fractions (10-16 Gy total dose) or 4 equal sized fractions (12 to 21 Gy total dose). At regular time intervals after treatment, the left kidney function was assessed with the use of 99mTc-Dimercaptosuccinic acid for a period of about 1 year. It was found that renal function declined in a dose- and time-dependent manner. The threshold dose for detecting functional impairment was 8 Gy for 1 fraction, 12 Gy for 2 fraction and 15 Gy for 4 fraction irradiations, demonstrating the sensitivity of the isotope tracer test used in these experiments. Retreatment of the rats with a single i.p. dose of 5 mg/kg cis-Dichlorodiammineplatinum (II) (cis-DDP) given at about 1 year after X ray exposure revealed an important relative decrease in the function of the irradiated compared to the unirradiated kidney. Reductions in function of 11 to 70% (depending on radiation dose and schedule) compared with control values were observed at 11 weeks after drug injection. These results demonstrate that a previously irradiated kidney is more sensitive to a subsequent treatment with cis-DDP than the contralateral hypertrophied kidney in the same animal.
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Explore the source record for details and available documents.
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Explore the source record for details and available documents.