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Papers by Piet Dijkstra

Research paper thumbnail of A 100-year-old anatomical specimen presenting with boomerang-like skeletal dysplasia: Diagnostic strategies and outcome

A 100-year-old anatomical specimen presenting with boomerang-like skeletal dysplasia: Diagnostic strategies and outcome

American Journal of Medical Genetics, Jul 16, 1999

The Museum Vrolik collection of human anatomy comprises 360 recently redescribed specimens with c... more The Museum Vrolik collection of human anatomy comprises 360 recently redescribed specimens with congenital anomalies. The specimen described here dated from 1881 and presented with a general embryonic appearance, disproportionate short stature, brachycephaly, widened cranial sutures, hypertelorism, microphthalmia, bilateral cleft lip and palate, micrognathia, short and curved limbs, polysyndactyly, and abnormal female genitalia. Conventional radiography was hampered by decalcification of the skeleton, due to acidification of the preservation fluid. The use of additional imaging techniques, i.e., mammography, computerized tomography with three-dimensional reconstruction, and magnetic resonance imaging eventually led us to conclude that the condition of our specimen was similar to Piepkorn type skeletal dysplasia, boomerang dysplasia, and a condition described by Carpenter and Hunter [1982: J Med Genet 19:311-315], though none of these diagnoses seemed fully applicable.

Research paper thumbnail of Uniform fat suppression in hands and feet through the use of two-point Dixon chemical shift MR imaging

Uniform fat suppression in hands and feet through the use of two-point Dixon chemical shift MR imaging

J Magn Reson Imaging, 1999

To assess the potential of two-point Dixon chemical shift magnetic resonance imaging to achieve u... more To assess the potential of two-point Dixon chemical shift magnetic resonance imaging to achieve uniform fat suppression in the distal parts of the extremities. Two-point Dixon chemical shift imaging was performed in 31 consecutive patients clinically suspected to have bone marrow disease. In some patients, Dixon studies were performed before and after the intravenous administration of gadopentetate dimeglumine, and in some patients follow-up examinations were performed, for a total of 64 studies. Areas of interest were the hand, wrist, foot, ankle, and lower leg. There was a special interest in the neuropathic foot and osteomyelitis. The uniformity of fat suppression in the entire field of view, the frequency of displacement artifacts, and the applicability of the technique in routine patient treatment were evaluated. In 64 (100%) Dixon studies, uniform fat suppression was achieved. In 59 (92%) studies, there were no displacement artifacts. In five (8%) studies, displacement artifacts occurred; however, in only one (2%) study did they severely hamper the reading. Thus, in 63 (98%) studies, adequate diagnostic quality was obtained. Two-point Dixon chemical shift imaging is a good technique for achieving uniform fat suppression in the distal parts of the extremities. Because the frequency of displacement artifacts is low, the technique is applicable in a routine clinical setting.

Research paper thumbnail of Achondrogenesis…Hypochondrogenesis: the Spectrum of Chondrogenesis Imperfecta a Radiological, Ultrasonographic, and Histopathologic Study of 23 Cases

Achondrogenesis…Hypochondrogenesis: the Spectrum of Chondrogenesis Imperfecta a Radiological, Ultrasonographic, and Histopathologic Study of 23 Cases

In the classification of lethal osteochondrodysplasias, achondrogenesis and hypochondrogenesis ha... more In the classification of lethal osteochondrodysplasias, achondrogenesis and hypochondrogenesis have recently received special attention. We describe 23 cases representing the different subtypes. Within the classical type I (Parenti-Fraccaro) two distinct disorders can be recognized: type IA (Houston-Harris) and type IB (Fraccaro). The classical type II (Langer-Saldino) and hypochondrogenesis represent phenotypic variants of one disorder in which type II is the most severe form and hypochondrogenesis the mildest form, while transitional forms exist. It is likely that a basic defect in cellular function of the chondrocyte results in a deficient cartilage matrix and in disorganized enchondral ossification.

Research paper thumbnail of Perinatal Lethal Osteogenesis Imperfecta: Radiologic and Pathologic Evaluation of Seven Prenatally Diagnosed Cases

Perinatal Lethal Osteogenesis Imperfecta: Radiologic and Pathologic Evaluation of Seven Prenatally Diagnosed Cases

Pediatric Pathology Affiliated With the International Paediatric Pathology Association, Feb 1, 1988

The radiologic and pathologic characteristics of 7 cases of lethal osteogenesis imperfecta (OI), ... more The radiologic and pathologic characteristics of 7 cases of lethal osteogenesis imperfecta (OI), diagnosed prenatally by ultrasound in the 15th to 34th week, are described. They include four variants of the Sillence classification: types IIA, IIB, IIC, and type III. The radiologic criteria that differentiate these types of OI are described. The histopathology of the bones differed only slightly in types IIA, IIB, and III; OI type IIC, however, differed markedly from the other types.

Research paper thumbnail of Metacarpophalangeal pattern profile analysis in Rubinstein-Taybi syndrome

American Journal of Medical Genetics, 2005

pattern profile (MCPP) was determined in 49 radiographs of 40 patients with Rubinstein-Taybi synd... more pattern profile (MCPP) was determined in 49 radiographs of 40 patients with Rubinstein-Taybi syndrome. Two recognizable hand profiles were seen, depending on the configuration of the thumb and on age. Patients with a straight thumb showed a short first proximal phalanx, and short third medial phalanx. Patients with a radially deviated thumb had a short first proximal phalanx. Depending on age, a relatively large (infancy) or markedly short (older patients) first distal phalanx was found. The similarity between the patients was high. A third group of patients did not show a particular hand profile, but only small hand bones. The pattern variability indices were high in all groups of patients.

Research paper thumbnail of Prenatal ultrasonographic diagnosis of osteogenesis imperfecta

Prenatal ultrasonographic diagnosis of osteogenesis imperfecta

American Journal of Obstetrics and Gynecology, 1988

Between 1982 and 1986, osteogenesis imperfecta was diagnosed by ultrasound in seven fetuses. The ... more Between 1982 and 1986, osteogenesis imperfecta was diagnosed by ultrasound in seven fetuses. The known heterogeneity of osteogenesis imperfecta was confirmed by the prenatal ultrasonographic findings. Dependent on the type of osteogenesis imperfecta, the appearance of the limbs varied from severely shortened and broad, with very low echogeneity and absent acoustic shadow (type IIA), to only moderately shortened and thin, with almost normal echogeneity and acoustic shadow but clearly visible fractures causing angulation of the bone (types IIC and III). Ultrasonography offers the possibility to detect or exclude the lethal and severe forms of osteogenesis imperfecta early (type IIA) or halfway (types IIB, IIC, and III) through the second trimester. Prenatal diagnosis of the disease allows the option of elective abortion or may prevent unnecessary obstetric intervention.

Research paper thumbnail of Uniform Fat Suppression in Hands and Feet through the Use of Two-Point Dixon Chemical Shift MR Imaging

Uniform Fat Suppression in Hands and Feet through the Use of Two-Point Dixon Chemical Shift MR Imaging

Radiology, 1999

To assess the potential of two-point Dixon chemical shift magnetic resonance imaging to achieve u... more To assess the potential of two-point Dixon chemical shift magnetic resonance imaging to achieve uniform fat suppression in the distal parts of the extremities. Two-point Dixon chemical shift imaging was performed in 31 consecutive patients clinically suspected to have bone marrow disease. In some patients, Dixon studies were performed before and after the intravenous administration of gadopentetate dimeglumine, and in some patients follow-up examinations were performed, for a total of 64 studies. Areas of interest were the hand, wrist, foot, ankle, and lower leg. There was a special interest in the neuropathic foot and osteomyelitis. The uniformity of fat suppression in the entire field of view, the frequency of displacement artifacts, and the applicability of the technique in routine patient treatment were evaluated. In 64 (100%) Dixon studies, uniform fat suppression was achieved. In 59 (92%) studies, there were no displacement artifacts. In five (8%) studies, displacement artifacts occurred; however, in only one (2%) study did they severely hamper the reading. Thus, in 63 (98%) studies, adequate diagnostic quality was obtained. Two-point Dixon chemical shift imaging is a good technique for achieving uniform fat suppression in the distal parts of the extremities. Because the frequency of displacement artifacts is low, the technique is applicable in a routine clinical setting.

Research paper thumbnail of General overgrowth in the fragile X syndrome: variability in the phenotypic expression of the FMR1 gene mutation

Journal of Medical Genetics, 1995

The fragile X syndrome, which often presents in childhood with overgrowth, may in some cases show... more The fragile X syndrome, which often presents in childhood with overgrowth, may in some cases show some diagnostic overlap with classical Sotos syndrome. We describe four fragile X patients with general overgrowth, all of whom are from families with other affected relatives who show the classic Martin-Bell phenotype. Molecular studies of the FMR1 gene in all cases showed the typical full mutation as seen in males affected by the fragile X syndrome. Endocrine studies were unremarkable, except in one case where there were raised levels of insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3)

Research paper thumbnail of MCP analysis and its role in the treatment of congenital hand malformations

The Journal of Hand Surgery: Journal of the British Society for Surgery of the Hand, 1996

Based on our own experiments on piglets from 1983 to 1986 and the clinical experience of Yu Dong ... more Based on our own experiments on piglets from 1983 to 1986 and the clinical experience of Yu Dong Gu from Shanghai, we used, in 199415, supplementary one spinal nerve C7 from the healthy side for the neurotization in total avulsions of the brachial plexus. We studied the sequels of such a procedure and the efficiency of the reinervation in the paralyzed upper extremity.

Research paper thumbnail of Professor Jan Feijen—30 years research in biomedical technology

Journal of Controlled Release, 2005

he also initiated a joint program together with these investigators to develop drug delivery syst... more he also initiated a joint program together with these investigators to develop drug delivery systems based on biodegradable polymers.

Professor Jan Feijen was trained as an organic and polymer chemist at the University of Groningen in the Netherlands. After he received his Ph.D. in 1970 from Prof. H. Wynberg, he became an Assistant Professor of Materials Science and Technology at the University of Twente. From 1972 to 1973 he was a visiting assistant professor at the University of Utah, working with Professor Lyman in the field of biomaterials and Professor Kolff in his artificial heart program. After his return to The Netherlands, he started an exchange program for Ph.D. students with Professor Dr. Sung Wan Kim of the University of Utah and Professor Jim

Research paper thumbnail of The Value of Additional Carpal Box Radiographs in Suspected Scaphoid Fracture

The Value of Additional Carpal Box Radiographs in Suspected Scaphoid Fracture

INVESTIGATIVE RADIOLOGY, 1997

Carpal Box (CB) radiographs, transverse and longitudinal, produce elongated and magnified views o... more Carpal Box (CB) radiographs, transverse and longitudinal, produce elongated and magnified views of the carpus. These radiographs can be used after carpal injury, in addition to conventional scaphoid x-rays. In this study, the use of CB radiographs was evaluated in patients with possible scaphoid fracture. Seventy-one consecutive patients who presented at the First Aid department from May 1994 to May 1995 were included. All patients were examined for scaphoid fracture after a fall on the out-stretched hand. If a scaphoid fracture was seen on the scaphoid x-rays, patients were immobilized. If the x-rays remained negative or dubious for fracture, additional transverse and longitudinal CB radiographs were obtained. If CB radiographs remained negative or inconclusive, patients were referred for three-phase bone scintigraphy. The results of independent and masked judgment by three different observers were used for an inter- and intraobserver analysis. Twenty of 71 patients initially showed a scaphoid fracture on the conventional scaphoid x-rays, 41 were negative, and 10 inconclusive. All 41 negative patients remained negative on CB radiograph; however, the bone scintigraphy was positive for scaphoid fracture in 11 patients and in 9 patients a hot spot elsewhere in the carpus was found. Of the 10 patients with inconclusive x-rays, 2 showed a clear fracture of the scaphoid on CB radiograph, 5 were negative, and 3 remained inconclusive. The agreement between observers, calculated in kappa values, was highest in CB radiographs. In the diagnosis of scaphoid fracture, Carpal Box radiography is of limited value in patients with clinically suspected scaphoid fracture. In two of 10 patients with initial dubious scaphoid x-ray, bone scintigraphy can be avoided. Furthermore, the reliability of the interpretation of the radiographs is increased by additional Carpal Box radiography.

Research paper thumbnail of Radiography of the Carpal Scaphoid

Radiography of the Carpal Scaphoid

Investigative Radiology, 1992

Research paper thumbnail of Double translocation t(7;12),t(2;6) heterozygosity in one family

Human Genetics, 1978

Double translocation heterozygosity t(2;6),t(7;12) in three generations of a Dutch family is desc... more Double translocation heterozygosity t(2;6),t(7;12) in three generations of a Dutch family is described: the segregation of a double translocation in more than one generation has not been previously published. The index case was a 16-year-old mentally retarded boy with partial trisomy 12p who showed several dysmorphic features such as high prominent forehead, flat face, flat and short nose bridge, short nose, dysplastic ears, prominent lower lip, and several skeletal abnormalities. Based on the findings in this patient and those in nine other cases, the existence of a specific trisomy 12p syndrome is postulated.

Research paper thumbnail of Perinatal Lethal Osteogenesis Imperfecta: Radiologic and Pathologic Evaluation of Seven Prenatally Diagnosed Cases

Perinatal Lethal Osteogenesis Imperfecta: Radiologic and Pathologic Evaluation of Seven Prenatally Diagnosed Cases

Fetal & Pediatric Pathology, 1988

The radiologic and pathologic characteristics of 7 cases of lethal osteogenesis imperfecta (OI), ... more The radiologic and pathologic characteristics of 7 cases of lethal osteogenesis imperfecta (OI), diagnosed prenatally by ultrasound in the 15th to 34th week, are described. They include four variants of the Sillence classification: types IIA, IIB, IIC, and type III. The radiologic criteria that differentiate these types of OI are described. The histopathology of the bones differed only slightly in types IIA, IIB, and III; OI type IIC, however, differed markedly from the other types.

Research paper thumbnail of Achondrogenesis…Hypochondrogenesis: the Spectrum of Chondrogenesis Imperfecta a Radiological, Ultrasonographic, and Histopathologic Study of 23 Cases

Achondrogenesis…Hypochondrogenesis: the Spectrum of Chondrogenesis Imperfecta a Radiological, Ultrasonographic, and Histopathologic Study of 23 Cases

Fetal & Pediatric Pathology, 1988

In the classification of lethal osteochondrodysplasias, achondrogenesis and hypochondrogenesis ha... more In the classification of lethal osteochondrodysplasias, achondrogenesis and hypochondrogenesis have recently received special attention. We describe 23 cases representing the different subtypes. Within the classical type I (Parenti-Fraccaro) two distinct disorders can be recognized: type IA (Houston-Harris) and type IB (Fraccaro). The classical type II (Langer-Saldino) and hypochondrogenesis represent phenotypic variants of one disorder in which type II is the most severe form and hypochondrogenesis the mildest form, while transitional forms exist. It is likely that a basic defect in cellular function of the chondrocyte results in a deficient cartilage matrix and in disorganized enchondral ossification.

Research paper thumbnail of Significance of a hot spot on the bone scan after carpal injury ?evaluation by computed tomography

European Journal of Nuclear Medicine, 1993

The use of bone scintigraphy in patients with negative radiographs after carpal injury is widely ... more The use of bone scintigraphy in patients with negative radiographs after carpal injury is widely advocated. However, focally increased activity on the bone scan in the scaphoid or other carpal bones cannot always be radiologically confirmed as a fracture. To confirm scintigraphically suspected carpal fractures, computed tomography (CT) of the wrist was performed in patients with clinically suspected scaphoid fracture and initially negative radiographs. All patients underwent plain radiography, bone scintigraphy and CT. The combination of plain radiographs and CT, as judged by a panel of experienced observers, was used as the reference standard. In 18 patients, 21 out of 22 carpal hot spots on bone scintigraphy could be radiologically confirmed as a fracture. The diagnosis was missed by CT scan in three patients with proven fractures on plain radiographs. We conclude that, in patients with negative initial radiographs following carpal injury, a positive bone scan must be interpreted as a fracture.

Research paper thumbnail of Radiologic features in juvenile idiopathic arthritis: A first step in the development of a standardized assessment method

Arthritis & Rheumatism, 2003

To describe radiologic features of patients with juvenile idiopathic arthritis (JIA) in a standar... more To describe radiologic features of patients with juvenile idiopathic arthritis (JIA) in a standardized manner, to test the reliability and feasibility of this description, and to correlate these features with clinical signs as a first step in the development of a standardized assessment method.

Research paper thumbnail of Sulfasalazine in the treatment of juvenile chronic arthritis: A randomized, double-blind, placebo-controlled, multicenter study

Sulfasalazine in the treatment of juvenile chronic arthritis: A randomized, double-blind, placebo-controlled, multicenter study

Arthritis & Rheumatism, 1998

To assess the efficacy, tolerability, and safety of sulfasalazine (SSZ) in the treatment of juven... more To assess the efficacy, tolerability, and safety of sulfasalazine (SSZ) in the treatment of juvenile chronic arthritis (JCA). We conducted a 24-week randomized, placebo-controlled, double-blind, multicenter study of patients with active JCA of both oligoarticular and polyarticular onset. Patients were treated with a dosage of 50 mg/kg/day of SSZ (maximum 2,000 mg/day) or placebo. The efficacy variables were joint scores, physician's, parents', and patient's overall assessments, and laboratory parameters of inflammation. Of the 69 patients enrolled, 52 (75%) completed the trial. Six patients (18%) withdrew from the placebo group, and 11 (31%) withdrew from the SSZ group (P = 0.18). In the intention-to-treat analysis of end point efficacy, between-group differences were significant for the overall articular severity score (P = 0.02), all global assessments (P = 0.01), and the laboratory parameters (P < 0.001). Adverse events occurred more frequently in the SSZ group and were the main reason for withdrawal (P < 0.001), but in all instances, these events were transient or reversible upon cessation of treatment. The results of this first placebo-controlled study show that SSZ is effective and safe in the treatment of children with oligoarticular- and polyarticular-onset JCA, although it was not well tolerated in one-third of the patients.

Research paper thumbnail of Metacarpophalangeal pattern profile analysis in Sotos and Marfan syndrome

Metacarpophalangeal pattern profile analysis in Sotos and Marfan syndrome

American Journal of Medical Genetics, 1994

Research paper thumbnail of Autosomal dominant familial radial luxation, carpal fusion and scapular dysplasia with variable heart defects

Autosomal dominant familial radial luxation, carpal fusion and scapular dysplasia with variable heart defects

American Journal of Medical Genetics, 1996

A family is described with skeletal abnormalities involving the shoulder, elbow, and hand, in com... more A family is described with skeletal abnormalities involving the shoulder, elbow, and hand, in combination with variable cardiac defects including conduction defects and anatomical anomalies. The disorder followed an autosomal dominant pattern of inheritance with apparently full penetrance for the skeletal abnormalities and reduced penetrance for the cardiac defects.

Research paper thumbnail of A 100-year-old anatomical specimen presenting with boomerang-like skeletal dysplasia: Diagnostic strategies and outcome

A 100-year-old anatomical specimen presenting with boomerang-like skeletal dysplasia: Diagnostic strategies and outcome

American Journal of Medical Genetics, Jul 16, 1999

The Museum Vrolik collection of human anatomy comprises 360 recently redescribed specimens with c... more The Museum Vrolik collection of human anatomy comprises 360 recently redescribed specimens with congenital anomalies. The specimen described here dated from 1881 and presented with a general embryonic appearance, disproportionate short stature, brachycephaly, widened cranial sutures, hypertelorism, microphthalmia, bilateral cleft lip and palate, micrognathia, short and curved limbs, polysyndactyly, and abnormal female genitalia. Conventional radiography was hampered by decalcification of the skeleton, due to acidification of the preservation fluid. The use of additional imaging techniques, i.e., mammography, computerized tomography with three-dimensional reconstruction, and magnetic resonance imaging eventually led us to conclude that the condition of our specimen was similar to Piepkorn type skeletal dysplasia, boomerang dysplasia, and a condition described by Carpenter and Hunter [1982: J Med Genet 19:311-315], though none of these diagnoses seemed fully applicable.

Research paper thumbnail of Uniform fat suppression in hands and feet through the use of two-point Dixon chemical shift MR imaging

Uniform fat suppression in hands and feet through the use of two-point Dixon chemical shift MR imaging

J Magn Reson Imaging, 1999

To assess the potential of two-point Dixon chemical shift magnetic resonance imaging to achieve u... more To assess the potential of two-point Dixon chemical shift magnetic resonance imaging to achieve uniform fat suppression in the distal parts of the extremities. Two-point Dixon chemical shift imaging was performed in 31 consecutive patients clinically suspected to have bone marrow disease. In some patients, Dixon studies were performed before and after the intravenous administration of gadopentetate dimeglumine, and in some patients follow-up examinations were performed, for a total of 64 studies. Areas of interest were the hand, wrist, foot, ankle, and lower leg. There was a special interest in the neuropathic foot and osteomyelitis. The uniformity of fat suppression in the entire field of view, the frequency of displacement artifacts, and the applicability of the technique in routine patient treatment were evaluated. In 64 (100%) Dixon studies, uniform fat suppression was achieved. In 59 (92%) studies, there were no displacement artifacts. In five (8%) studies, displacement artifacts occurred; however, in only one (2%) study did they severely hamper the reading. Thus, in 63 (98%) studies, adequate diagnostic quality was obtained. Two-point Dixon chemical shift imaging is a good technique for achieving uniform fat suppression in the distal parts of the extremities. Because the frequency of displacement artifacts is low, the technique is applicable in a routine clinical setting.

Research paper thumbnail of Achondrogenesis…Hypochondrogenesis: the Spectrum of Chondrogenesis Imperfecta a Radiological, Ultrasonographic, and Histopathologic Study of 23 Cases

Achondrogenesis…Hypochondrogenesis: the Spectrum of Chondrogenesis Imperfecta a Radiological, Ultrasonographic, and Histopathologic Study of 23 Cases

In the classification of lethal osteochondrodysplasias, achondrogenesis and hypochondrogenesis ha... more In the classification of lethal osteochondrodysplasias, achondrogenesis and hypochondrogenesis have recently received special attention. We describe 23 cases representing the different subtypes. Within the classical type I (Parenti-Fraccaro) two distinct disorders can be recognized: type IA (Houston-Harris) and type IB (Fraccaro). The classical type II (Langer-Saldino) and hypochondrogenesis represent phenotypic variants of one disorder in which type II is the most severe form and hypochondrogenesis the mildest form, while transitional forms exist. It is likely that a basic defect in cellular function of the chondrocyte results in a deficient cartilage matrix and in disorganized enchondral ossification.

Research paper thumbnail of Perinatal Lethal Osteogenesis Imperfecta: Radiologic and Pathologic Evaluation of Seven Prenatally Diagnosed Cases

Perinatal Lethal Osteogenesis Imperfecta: Radiologic and Pathologic Evaluation of Seven Prenatally Diagnosed Cases

Pediatric Pathology Affiliated With the International Paediatric Pathology Association, Feb 1, 1988

The radiologic and pathologic characteristics of 7 cases of lethal osteogenesis imperfecta (OI), ... more The radiologic and pathologic characteristics of 7 cases of lethal osteogenesis imperfecta (OI), diagnosed prenatally by ultrasound in the 15th to 34th week, are described. They include four variants of the Sillence classification: types IIA, IIB, IIC, and type III. The radiologic criteria that differentiate these types of OI are described. The histopathology of the bones differed only slightly in types IIA, IIB, and III; OI type IIC, however, differed markedly from the other types.

Research paper thumbnail of Metacarpophalangeal pattern profile analysis in Rubinstein-Taybi syndrome

American Journal of Medical Genetics, 2005

pattern profile (MCPP) was determined in 49 radiographs of 40 patients with Rubinstein-Taybi synd... more pattern profile (MCPP) was determined in 49 radiographs of 40 patients with Rubinstein-Taybi syndrome. Two recognizable hand profiles were seen, depending on the configuration of the thumb and on age. Patients with a straight thumb showed a short first proximal phalanx, and short third medial phalanx. Patients with a radially deviated thumb had a short first proximal phalanx. Depending on age, a relatively large (infancy) or markedly short (older patients) first distal phalanx was found. The similarity between the patients was high. A third group of patients did not show a particular hand profile, but only small hand bones. The pattern variability indices were high in all groups of patients.

Research paper thumbnail of Prenatal ultrasonographic diagnosis of osteogenesis imperfecta

Prenatal ultrasonographic diagnosis of osteogenesis imperfecta

American Journal of Obstetrics and Gynecology, 1988

Between 1982 and 1986, osteogenesis imperfecta was diagnosed by ultrasound in seven fetuses. The ... more Between 1982 and 1986, osteogenesis imperfecta was diagnosed by ultrasound in seven fetuses. The known heterogeneity of osteogenesis imperfecta was confirmed by the prenatal ultrasonographic findings. Dependent on the type of osteogenesis imperfecta, the appearance of the limbs varied from severely shortened and broad, with very low echogeneity and absent acoustic shadow (type IIA), to only moderately shortened and thin, with almost normal echogeneity and acoustic shadow but clearly visible fractures causing angulation of the bone (types IIC and III). Ultrasonography offers the possibility to detect or exclude the lethal and severe forms of osteogenesis imperfecta early (type IIA) or halfway (types IIB, IIC, and III) through the second trimester. Prenatal diagnosis of the disease allows the option of elective abortion or may prevent unnecessary obstetric intervention.

Research paper thumbnail of Uniform Fat Suppression in Hands and Feet through the Use of Two-Point Dixon Chemical Shift MR Imaging

Uniform Fat Suppression in Hands and Feet through the Use of Two-Point Dixon Chemical Shift MR Imaging

Radiology, 1999

To assess the potential of two-point Dixon chemical shift magnetic resonance imaging to achieve u... more To assess the potential of two-point Dixon chemical shift magnetic resonance imaging to achieve uniform fat suppression in the distal parts of the extremities. Two-point Dixon chemical shift imaging was performed in 31 consecutive patients clinically suspected to have bone marrow disease. In some patients, Dixon studies were performed before and after the intravenous administration of gadopentetate dimeglumine, and in some patients follow-up examinations were performed, for a total of 64 studies. Areas of interest were the hand, wrist, foot, ankle, and lower leg. There was a special interest in the neuropathic foot and osteomyelitis. The uniformity of fat suppression in the entire field of view, the frequency of displacement artifacts, and the applicability of the technique in routine patient treatment were evaluated. In 64 (100%) Dixon studies, uniform fat suppression was achieved. In 59 (92%) studies, there were no displacement artifacts. In five (8%) studies, displacement artifacts occurred; however, in only one (2%) study did they severely hamper the reading. Thus, in 63 (98%) studies, adequate diagnostic quality was obtained. Two-point Dixon chemical shift imaging is a good technique for achieving uniform fat suppression in the distal parts of the extremities. Because the frequency of displacement artifacts is low, the technique is applicable in a routine clinical setting.

Research paper thumbnail of General overgrowth in the fragile X syndrome: variability in the phenotypic expression of the FMR1 gene mutation

Journal of Medical Genetics, 1995

The fragile X syndrome, which often presents in childhood with overgrowth, may in some cases show... more The fragile X syndrome, which often presents in childhood with overgrowth, may in some cases show some diagnostic overlap with classical Sotos syndrome. We describe four fragile X patients with general overgrowth, all of whom are from families with other affected relatives who show the classic Martin-Bell phenotype. Molecular studies of the FMR1 gene in all cases showed the typical full mutation as seen in males affected by the fragile X syndrome. Endocrine studies were unremarkable, except in one case where there were raised levels of insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3)

Research paper thumbnail of MCP analysis and its role in the treatment of congenital hand malformations

The Journal of Hand Surgery: Journal of the British Society for Surgery of the Hand, 1996

Based on our own experiments on piglets from 1983 to 1986 and the clinical experience of Yu Dong ... more Based on our own experiments on piglets from 1983 to 1986 and the clinical experience of Yu Dong Gu from Shanghai, we used, in 199415, supplementary one spinal nerve C7 from the healthy side for the neurotization in total avulsions of the brachial plexus. We studied the sequels of such a procedure and the efficiency of the reinervation in the paralyzed upper extremity.

Research paper thumbnail of Professor Jan Feijen—30 years research in biomedical technology

Journal of Controlled Release, 2005

he also initiated a joint program together with these investigators to develop drug delivery syst... more he also initiated a joint program together with these investigators to develop drug delivery systems based on biodegradable polymers.

Professor Jan Feijen was trained as an organic and polymer chemist at the University of Groningen in the Netherlands. After he received his Ph.D. in 1970 from Prof. H. Wynberg, he became an Assistant Professor of Materials Science and Technology at the University of Twente. From 1972 to 1973 he was a visiting assistant professor at the University of Utah, working with Professor Lyman in the field of biomaterials and Professor Kolff in his artificial heart program. After his return to The Netherlands, he started an exchange program for Ph.D. students with Professor Dr. Sung Wan Kim of the University of Utah and Professor Jim

Research paper thumbnail of The Value of Additional Carpal Box Radiographs in Suspected Scaphoid Fracture

The Value of Additional Carpal Box Radiographs in Suspected Scaphoid Fracture

INVESTIGATIVE RADIOLOGY, 1997

Carpal Box (CB) radiographs, transverse and longitudinal, produce elongated and magnified views o... more Carpal Box (CB) radiographs, transverse and longitudinal, produce elongated and magnified views of the carpus. These radiographs can be used after carpal injury, in addition to conventional scaphoid x-rays. In this study, the use of CB radiographs was evaluated in patients with possible scaphoid fracture. Seventy-one consecutive patients who presented at the First Aid department from May 1994 to May 1995 were included. All patients were examined for scaphoid fracture after a fall on the out-stretched hand. If a scaphoid fracture was seen on the scaphoid x-rays, patients were immobilized. If the x-rays remained negative or dubious for fracture, additional transverse and longitudinal CB radiographs were obtained. If CB radiographs remained negative or inconclusive, patients were referred for three-phase bone scintigraphy. The results of independent and masked judgment by three different observers were used for an inter- and intraobserver analysis. Twenty of 71 patients initially showed a scaphoid fracture on the conventional scaphoid x-rays, 41 were negative, and 10 inconclusive. All 41 negative patients remained negative on CB radiograph; however, the bone scintigraphy was positive for scaphoid fracture in 11 patients and in 9 patients a hot spot elsewhere in the carpus was found. Of the 10 patients with inconclusive x-rays, 2 showed a clear fracture of the scaphoid on CB radiograph, 5 were negative, and 3 remained inconclusive. The agreement between observers, calculated in kappa values, was highest in CB radiographs. In the diagnosis of scaphoid fracture, Carpal Box radiography is of limited value in patients with clinically suspected scaphoid fracture. In two of 10 patients with initial dubious scaphoid x-ray, bone scintigraphy can be avoided. Furthermore, the reliability of the interpretation of the radiographs is increased by additional Carpal Box radiography.

Research paper thumbnail of Radiography of the Carpal Scaphoid

Radiography of the Carpal Scaphoid

Investigative Radiology, 1992

Research paper thumbnail of Double translocation t(7;12),t(2;6) heterozygosity in one family

Human Genetics, 1978

Double translocation heterozygosity t(2;6),t(7;12) in three generations of a Dutch family is desc... more Double translocation heterozygosity t(2;6),t(7;12) in three generations of a Dutch family is described: the segregation of a double translocation in more than one generation has not been previously published. The index case was a 16-year-old mentally retarded boy with partial trisomy 12p who showed several dysmorphic features such as high prominent forehead, flat face, flat and short nose bridge, short nose, dysplastic ears, prominent lower lip, and several skeletal abnormalities. Based on the findings in this patient and those in nine other cases, the existence of a specific trisomy 12p syndrome is postulated.

Research paper thumbnail of Perinatal Lethal Osteogenesis Imperfecta: Radiologic and Pathologic Evaluation of Seven Prenatally Diagnosed Cases

Perinatal Lethal Osteogenesis Imperfecta: Radiologic and Pathologic Evaluation of Seven Prenatally Diagnosed Cases

Fetal & Pediatric Pathology, 1988

The radiologic and pathologic characteristics of 7 cases of lethal osteogenesis imperfecta (OI), ... more The radiologic and pathologic characteristics of 7 cases of lethal osteogenesis imperfecta (OI), diagnosed prenatally by ultrasound in the 15th to 34th week, are described. They include four variants of the Sillence classification: types IIA, IIB, IIC, and type III. The radiologic criteria that differentiate these types of OI are described. The histopathology of the bones differed only slightly in types IIA, IIB, and III; OI type IIC, however, differed markedly from the other types.

Research paper thumbnail of Achondrogenesis…Hypochondrogenesis: the Spectrum of Chondrogenesis Imperfecta a Radiological, Ultrasonographic, and Histopathologic Study of 23 Cases

Achondrogenesis…Hypochondrogenesis: the Spectrum of Chondrogenesis Imperfecta a Radiological, Ultrasonographic, and Histopathologic Study of 23 Cases

Fetal & Pediatric Pathology, 1988

In the classification of lethal osteochondrodysplasias, achondrogenesis and hypochondrogenesis ha... more In the classification of lethal osteochondrodysplasias, achondrogenesis and hypochondrogenesis have recently received special attention. We describe 23 cases representing the different subtypes. Within the classical type I (Parenti-Fraccaro) two distinct disorders can be recognized: type IA (Houston-Harris) and type IB (Fraccaro). The classical type II (Langer-Saldino) and hypochondrogenesis represent phenotypic variants of one disorder in which type II is the most severe form and hypochondrogenesis the mildest form, while transitional forms exist. It is likely that a basic defect in cellular function of the chondrocyte results in a deficient cartilage matrix and in disorganized enchondral ossification.

Research paper thumbnail of Significance of a hot spot on the bone scan after carpal injury ?evaluation by computed tomography

European Journal of Nuclear Medicine, 1993

The use of bone scintigraphy in patients with negative radiographs after carpal injury is widely ... more The use of bone scintigraphy in patients with negative radiographs after carpal injury is widely advocated. However, focally increased activity on the bone scan in the scaphoid or other carpal bones cannot always be radiologically confirmed as a fracture. To confirm scintigraphically suspected carpal fractures, computed tomography (CT) of the wrist was performed in patients with clinically suspected scaphoid fracture and initially negative radiographs. All patients underwent plain radiography, bone scintigraphy and CT. The combination of plain radiographs and CT, as judged by a panel of experienced observers, was used as the reference standard. In 18 patients, 21 out of 22 carpal hot spots on bone scintigraphy could be radiologically confirmed as a fracture. The diagnosis was missed by CT scan in three patients with proven fractures on plain radiographs. We conclude that, in patients with negative initial radiographs following carpal injury, a positive bone scan must be interpreted as a fracture.

Research paper thumbnail of Radiologic features in juvenile idiopathic arthritis: A first step in the development of a standardized assessment method

Arthritis & Rheumatism, 2003

To describe radiologic features of patients with juvenile idiopathic arthritis (JIA) in a standar... more To describe radiologic features of patients with juvenile idiopathic arthritis (JIA) in a standardized manner, to test the reliability and feasibility of this description, and to correlate these features with clinical signs as a first step in the development of a standardized assessment method.

Research paper thumbnail of Sulfasalazine in the treatment of juvenile chronic arthritis: A randomized, double-blind, placebo-controlled, multicenter study

Sulfasalazine in the treatment of juvenile chronic arthritis: A randomized, double-blind, placebo-controlled, multicenter study

Arthritis & Rheumatism, 1998

To assess the efficacy, tolerability, and safety of sulfasalazine (SSZ) in the treatment of juven... more To assess the efficacy, tolerability, and safety of sulfasalazine (SSZ) in the treatment of juvenile chronic arthritis (JCA). We conducted a 24-week randomized, placebo-controlled, double-blind, multicenter study of patients with active JCA of both oligoarticular and polyarticular onset. Patients were treated with a dosage of 50 mg/kg/day of SSZ (maximum 2,000 mg/day) or placebo. The efficacy variables were joint scores, physician's, parents', and patient's overall assessments, and laboratory parameters of inflammation. Of the 69 patients enrolled, 52 (75%) completed the trial. Six patients (18%) withdrew from the placebo group, and 11 (31%) withdrew from the SSZ group (P = 0.18). In the intention-to-treat analysis of end point efficacy, between-group differences were significant for the overall articular severity score (P = 0.02), all global assessments (P = 0.01), and the laboratory parameters (P < 0.001). Adverse events occurred more frequently in the SSZ group and were the main reason for withdrawal (P < 0.001), but in all instances, these events were transient or reversible upon cessation of treatment. The results of this first placebo-controlled study show that SSZ is effective and safe in the treatment of children with oligoarticular- and polyarticular-onset JCA, although it was not well tolerated in one-third of the patients.

Research paper thumbnail of Metacarpophalangeal pattern profile analysis in Sotos and Marfan syndrome

Metacarpophalangeal pattern profile analysis in Sotos and Marfan syndrome

American Journal of Medical Genetics, 1994

Research paper thumbnail of Autosomal dominant familial radial luxation, carpal fusion and scapular dysplasia with variable heart defects

Autosomal dominant familial radial luxation, carpal fusion and scapular dysplasia with variable heart defects

American Journal of Medical Genetics, 1996

A family is described with skeletal abnormalities involving the shoulder, elbow, and hand, in com... more A family is described with skeletal abnormalities involving the shoulder, elbow, and hand, in combination with variable cardiac defects including conduction defects and anatomical anomalies. The disorder followed an autosomal dominant pattern of inheritance with apparently full penetrance for the skeletal abnormalities and reduced penetrance for the cardiac defects.