Temporal dynamics of sexual dimorphism in a dioecious species.

BACKGROUND AND AIMS: Sexual dimorphism for floral traits is common in dioecious plant species. Beyond its significance for understanding how selection acts on plant traits through male vs. female reproductive function, sexual dimorphism has also been proposed as a possible risky characteristic for insect-pollinated plants, as it could drive pollinators to forage mostly on male plants. However, even though most flowering plant species spread their flowering across several weeks or months, the temporal variation of floral phenotypes and sexual dimorphism have rarely been investigated. METHODS: We performed a survey of male and female plants from the dioecious generalist-pollinated Silene dioica (Caryophyllaceae) in a common garden experiment, over two consecutive flowering seasons. Flower number and floral size were measured each week, as well as pollen quantity and viability in male plants. KEY RESULTS: Sexual dimorphism was found for all investigated floral traits, with males showing an overall higher investment in flower production and flower size. Males and females showed a similar temporal decline in flower size. The temporal dynamics of daily flower number differed between sexes, with males showing a peak in the middle of their flowering season, whereas flower production by females was quite stable over time. At the scale of the experimental population, both individual and floral sex ratios appeared to vary across the flowering season. Moreover, because the onset of flowering varied among plants, the magnitude of sexual dimorphism in floral size also fluctuated strongly through time. CONCLUSIONS: Capturing male/female differences with only one temporal measurement per population may not be informative. This opens stimulating questions about how pollinator behaviour and resulting pollination efficiency may vary across the flowering season.

MR imaging of spondylitis with gadopentetate dimeglumine enhancement.

MR images of 17 patients with spondylitis were reviewed. T1 weighted spin-echo scans were obtained in 17 patients and proton density and T2 weighted scans were obtained in 15 patients. Unenhanced and gadopentetate dimeglumine enhanced scans were obtained in all patients. Five patients had pyogenic spondylitis, two patients tuberculous spondylitis, two patients fungal spondylitis and eight patients postoperative spondylitis. The four criteria described by Thrush and Enzmann were generally applicable in our study: 1) narrowing of the intervertebral disc; 2) cortical bone erosion; 3) abnormal signal in the adjacent vertebral bodies and 4) abnormal paraspinous or epidural soft tissue. In addition to plain sagittal T1 and T2 weighted images we suggest the routine administration of gadopentetate dimeglumine to assess the extent of the soft tissue mass and to differentiate postoperative spondylitis from a normal postoperative course, by showing disc enhancement. Disc enhancement occurs infrequently in the normal postoperative course. If it is associated with adjacent vertebral bone marrow changes it should be considered as postoperative spondylitis. A differential diagnosis between pyogenic, tuberculous, fungal and postoperative spondylitis was not possible although the pattern of enhancement in tuberculous spondylitis was different from the other cases of spondylitis.

The importance of magnetic resonance imaging in the diagnosis and treatment of diffuse lymphangioma.

In this study, we will investigate the importance of MRI in the diagnosis and treatment of diffuse lymphangioma. Twenty-nine patients with lymphangiomas were treated at the U.Z. Leuven between March 1988 and September 1997. They all underwent a total surgical excision of the lesion. A global recurrence rate of 34.45% corresponds with a recurrence rate of 30.76% found in literature. In our study, a remarkable difference in recurrence rates is noticed between cystic hygroma (5/19 patients or 26.39%) and the more diffuse types of lymphangioma (5/10 patients or 50%). On three patients, preoperative MRI was performed. All these illustrate the important role of MRI in the diagnosis of lymphangioma, namely the characteristic appearance of the lesions on T1- and T2-weighted images and the better visualization of the lymphangioma extent. In line with the high recurrence rates of diffuse lymphangiomas and the advantages of MRI of these lesions, the role of MRI in the treatment of diffuse lymphangiomas is discussed.

CT of soft tissue tumors.

We review the documented strengths and weaknesses of CT in the evaluation of soft tissue tumors and we describe what we believe to be an optimal CT technique. We also briefly outline the relation of CT to the other techniques in the diagnosis of soft tissue tumors and relate some particular CT findings to the major tumor types.

Parosteal osteosarcoma.

A case of parosteal osteosarcoma is reported. In spite of the pathognomonic plain radiographic signs of parosteal osteosarcoma, it is very uneasy to differentiate it from myositis ossificans circumscripta in the mature stage. CT and MRI defined the extent of the tumor into the soft tissue, the medullary and cortical invasion and gave more information about the composition of the lesion.

Dysplasia epiphysealis hemimelica (Trevor's disease).

The authors report a case of dysplasia epiphysealis hemimelica. This is a benign osteochondromatous epiphyseal overgrowth affecting most commonly the inferior limbs. The cartilage cap of the lesion can be demonstrated very accurately by MRI (gradient echo sequence). Early diagnosis and treatment is vital in preventing articular malformation and malfunction.

Adamantinoma of the tibia: MRI documentation.

We report two cases of adamantinoma of the tibia, for which an MR examination was performed. Each patient was initially investigated with plain radiography and in case 2, a computerized tomography was also performed. The MR characteristics of this tumor are scarcely documented in the even few case reports of this tumor. MRI does not add to the (differential) diagnosis but does have significance in the preoperative staging because it allows adequate delineation of tumor, which is essential for a complete and curative resection of the tumor.

Ultrasonography of the knee.

Despite the increasing use of MRI in knee disorders, ultrasonography remains the first choice examination technique in para-articular disease. The technique is fast, cheap, easily accessible and usable in the acutely injured patient. The choice of equipment, positioning of the patient and some characteristics of normal anatomy are described. The routine applications of ultrasonography include different types of tendon disease, trauma of the collateral ligaments, bursal pathology, joint effusions and synovitis, evaluation of the popliteal fossa and para-articular swellings. Other possible applications, somewhat more depending on the examiner's experience, are meniscal disease, trauma to the cruciate ligaments and evaluation of the articular cartilage and synovial plicae.

[Three-dimensional imaging of acetabular fractures using spiral CT]. / Driedimensionele beeldvorming van acetabulumfrakturen met spiraal CT.

Seven adult patients with acetabular fractures were investigated with conventional X-rays, axial spiral computed tomographic (CT) images and three-dimensional (3D) surface rendered reconstructions. Spiral CT has the advantage that it acquires the data much faster than incremental CT, resulting in less motion artefacts. A semi-automatic three-dimensional environment for segmentation has been developed in our institution. It created significant reduction of user interaction and improved visualization of acetabular and femoral joint surfaces. The main advantages of three-dimensional visualization of acetabular fractures included: creation of unlimited and unique views by which fracture location, fracture extension, fragment shape and fragment position became more clear, better visualization of acetabular dome and quadrilateral plate and more simple and easier interpretation of these complex fracture patterns. On the other hand, 3D surface reconstructions do not accurately demonstrate undisplaced fractures, intra-articular fragments may be obscured, congruence assessment is uneasy, and soft tissue injuries are not shown. Therefore, we consider 3D images of acetabular fractures as being complementary to and not a substitute to plain radiographs and axial CT scans.

Trans-iliac-sacral-iliac-bar procedure to treat insufficiency fractures of the sacrum.

BACKGROUND: Osteoporosis is an increasing problem attributed to the greater longevity of the population and the incidence of fractures related to osteoporosis. The presence of osteoporotic bone, comorbidities, and functional status of the patient require adequate solutions to improve the clinical outcome of sacral insufficiency fractures. Conservative treatment by means of prolonged bed rest and analgesics are associated with increased risks and complications. A sacroplasty significantly improves the functional outcome. We describe the trans-iliac-sacral-iliac-bar (TISIB) procedure and our clinical experience to treat insufficiency fractures of the sacrum. MATERIALS AND METHODS: The records of 19 consecutive patients with a mean age of 71.7 years (range: 57-82 years) who had been managed with a TISIB procedure from 2005 till 2007 were reviewed retrospectively. There were 15 females and 4 males. Predisposing factors for sacral insufficiency fractures were osteoporosis (n = 12, 63%), radiotherapy (n = 6, 32%), and rheumatoid arthritis (n =1). Diagnosis with a mean delay of 3.7 months was mainly made by CT. All patients were preoperatively and at follow-up assessed by means of the visual analogue score (VAS), analgesic consumption, and the ability to perform activities of daily living (ADLs) using a 5-point pain scale: 1, without pain; 2, mild pain; 3, moderate pain; 4, severe pain and, 5 unable to perform ADLs because of pain. RESULTS: The average duration of postoperative follow-up was 9 months (range: 3-24.5 months). No neurological complications occurred during the surgery. A postoperative radiographic study showed a well-positioned bar in every case. The mean VAS improved 44.7 mm (preoperative: 67.8; at follow-up: 23.2). Fifteen patients (79%) consumed narcotic analgesics before surgery, and only one (5%) at follow-up; two patients (10%) consumed NSAIDS before surgery and three (15%) after. Two patients (10%) consumed minor analgesics before, and 11 (58%) after the procedure. Finally, four patients (21%) were not taking any analgesics at follow-up. Before surgery, 9 patients (47%) were able to perform ADLs with a pain score of 4; 6 (32%) with a score of 3, and 4 (21%) a score of 2. At follow-up 1 (5%) did have a score of 4; 1 (5%) a score of 3, 8 (42%) a score of 2 and 9 (47%) a pain score of 1. CONCLUSION: A TISIB PROCEDURE RELIES ON THE PRINCIPLES OF FRACTURE TREATMENT: fracture stabilisation and compression. The incapacitating problem of an insufficiency fracture of the sacrum can be elegantly solved by means of this minimally invasive procedure. A near-immediate improvement is noticed when looking at the VAS score, analgesics consumption, and the ability to perform ADLs.

The use of 'hybrid' allografts in the treatment of fractures of the thoracolumbar spine: first experience.

Harvesting autogenous bone grafts of the iliac crest carries complications and lengthens operative times. Allografts are preferred to avoid these problems. Fusion after using allogenic bone grafts has been well studied, by examining trabeculations and remodelling on anteroposterior and lateral radiographs. However, the question remains whether one can rely on radiographs alone to determine fusion. 'Hybrid' fresh-frozen allografts from the femur or tibia were used in 11 adult patients with a mean age of 56.4 years (range: 30-78 years) to stabilize the thoracolumbar spine after anterior decompression for trauma. In one case two adjacent levels were fractured, in another case two fractures occurred at different levels. Fresh-frozen allografts of the femur (in ten cases) and tibia (one case), filled with autogenous cancellous bone graft or pieces of rib, were used to reconstruct the anterior column of the spine. Stabilization was performed by means of a Kaneda device. Anteroposterior and lateral radiographs and, additionally, computed tomography (CT) examinations with reconstructions were used to study fusion. One patient died 1 month after surgery. At follow-up in ten patients, after a mean time of 30.2 months (range: 18-42 months), ten allografts showed a grade I fusion and one a grade III fusion. Additional data from the CT examination with reconstructions, however, showed cross-trabeculations in all cases, and a partially united allograft in the patient with a grade III fusion. Cross-trabeculations between the allograft and vertebral body was observed at 6 months, with remodelling occurring at approximately 2 years. Mean loss of correction was minimal, at 3.6 degrees (range 0 degree-16 degrees). Fresh-frozen femoral or tibial allografts worked effectively to maintain correction after trauma when combined with anterior instrumentation. CT examinations with sagittal and coronal reconstructions were more effective for evaluation of fusion compared with anteroposterior and lateral radiographs. The high fusion rate and the low morbidity achieved using allografts in this way supports the exclusive use of allografts in the anterior thoracic and lumbar spine in the future.

Case report 814: Fibrolipoma of the median nerve.

A case of fibrolipoma of the median nerve was described. Peripheral nerve tumors of the upper extremity are very rare. Within this group of tumors, the fibrolipoma is an exceedingly uncommon entity. It was first described in 1953, and to date less than 100 cases have been described. The purpose of this report was to point out a characteristic sign of fibrolipoma, which in our opinion allows distinction on CT and MRI between fibrolipoma and the other peripheral nerve and fatty soft tissue tumors.

Tumour-induced rickets: a case report and review of the literature.

UNLABELLED: Hypophosphataemic rickets was diagnosed in a 6-year-old boy with a negative family history. After 16 years of medical treatment he developed a malignant sarcoma of the right distal thigh. Removal of the tumour by high amputation of the leg resulted in disappearance of the phosphate leak. In spite of surgery and chemotherapy, the patient died due to extensive lung metastases. Retrospective analysis of the initial X-ray films showed a benign lesion on the lateral side of the right distal femur. This lesion is believed to be at the origin of the rickets. This is the first paediatric case reported with malignant degeneration of a benign tumour causing rickets. CONCLUSION: Patients with the classical hallmarks of X-linked, familial hypophosphataemic rickets but no affected family members should have a careful periodic search for a tumour, even years after onset of the disorder.

Chondroblastoma of the patella with a secondary aneurysmal bone cyst.

A case of chondroblastoma of the patella combined with an aneurysmal bone cyst is presented. Chondroblastoma of the patella is an uncommon, benign neoplasm. On the other hand, secondary aneurysmal bone cyst is frequently associated with giant cell tumour of chondroblastoma.

Giant cell rich parosteal osteosarcoma.

A parosteal osteosarcoma of the distal femur with a typical radiographic and macroscopic appearance is reported. On histology the tumour was dominated by large numbers of osteoclast-like giant cells in a fibro-osseous background and islands of immature bone. Most of the neoplastic bone lacked osteoblastic rimming. There was no spatial relationship between the giant cells and areas of haemorrhage. Signs of 'dedifferentiation' were lacking. Cytogenetic a analysis revealed telomeric associations which are frequently found in giant cell tumours of bone. Parosteal osteosarcoma may, on histological appearances, hardly be recognizable as malignant. In addition, unusual changes such as abundant giant cells may be misleading in the absence of clinico-pathological correlation.

Proliferative myositis in a child.

A case of proliferative myositis in the lumbar paraspinal muscles in a 14-year-old boy is presented. Imaging investigations including plain radiograph, ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), bone scan and positron emission tomography (PET) were suggestive of an inflammatory process such as myositis ossificans. The diagnosis was made by incisional biopsy. More pronounced edema, more muscle fiber necrosis and a higher cellularity were found compared to adult cases. The karyotype of the lesion was normal. Clinically, the mass disappeared spontaneously. After 24 months, asymptomatic bridging ossification between the third and fourth lumbar vertebrae was noted.