Patellofemoral joint: kinematic MR imaging to assess tracking abnormalities

The patellofemoral joint was imaged with magnetic resonance (MR) in the axial plane while the knee was positioned from 0 degrees to 32 degrees of flexion (nine positions). These multiple sequential images obtained within the early phases of flexion of the knee were viewed in a "cine-loop" format, producing a kinematic study that clearly demonstrated the relationship of the patella to the trochlear groove. Four healthy subjects and one patient with known bilateral subluxing patellae were studied. The preliminary results suggest that kinematic MR imaging of the patellofemoral joint is potentially useful for the evaluation of patellar tracking abnormalities.     

Segmental duplications and gene conversion: Human luteinizing hormone/chorionic gonadotropin beta gene cluster

Segmental duplicons (>1 kb) of high sequence similarity (>90%) covering >5% of the human genome are characterized by complex sequence variation. Apart from a few well-characterized regions (MHC, β-globin), the diversity and linkage disequilibrium (LD) patterns of duplicons and the role of gene conversion in shaping them have been poorly studied. To shed light on these issues, we have re-sequenced the human Luteinizing Hormone/Chorionic Gonadotropin β (LHB/CGB) cluster (19q13.32) of three population samples (Estonians, Mandenka, and Han). The LHB/CGB cluster consists of seven duplicated genes critical in human reproduction. In the LHB/CGB region, high sequence diversity, concentration of gene-conversion acceptor sites, and strong LD colocalize with peripheral genes, whereas central loci are characterized by lower variation, gene-conversion donor activity, and breakdown of LD between close markers. The data highlight an important role of gene conversion in spreading polymorphisms among duplicon copies and generating LD around them. The directionality of gene-conversion events seems to be determined by the localization of a predicted recombination “hotspot” and “warm spot” in the vicinity of the most active acceptor genes at the periphery of the cluster. The data suggest that enriched crossover activity in direct and inverted segmental repeats is in accordance with the formation of palindromic secondary structures promoting double-strand breaks rather than fixed DNA sequence motifs. Also, this first detailed coverage of sequence diversity and structure of the LHB/CGB gene cluster will pave the way for studying the identified polymorphisms as well as potential genomic rearrangements in association with an individual's reproductive success.     

Critical ovarian hyperstimulation syndrome in a coasted in-vitro fertilization patient

We report an instance of critical ovarian hyperstimulation syndrome in a highly responsive in-vitro fertilization patient despite the preventive measure of a 4 day 'coast' interval during which no gonadotrophins were administered while gonadotrophin-releasing hormone agonist therapy continued until serum oestradiol concentrations fell below 3000 pg/ml.      

An unusual clinical presentation of bilateral schizencephaly

Summary We present a case with a characteristic magnetic resonance image (MRI) of bilateral open-lipped schizencephaly and atypical clinical presentation. The patient is still alive and in good health in her forties, she has never presented seizures, and although the motor dysfunction is well correlated with cerebral lobe involvement, neurobehavioral dysfunction is not proportional to the MR image of the cerebral malformation.

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Un cas inhabituel de schizencéphalie bilatérale

Résumé Nous présentons un cas de schizencéphalie bilatérale ouverte caractérisé par une présentation clinique atypique et une imagerie par résonance magnétique nucléaire caractéristique. La patiente est encore vivante, en bonne santé, à plus de 40 ans, elle n'a jamais présenté de crise comitiale et, bien que les troubles moteurs soient bien corrélés aux altérations cérébrales, les troubles neuro-comportementaux ne sont pas proportionnels aux images IRM de cette malformation cérébrale.

     

The transplantation of hematopoietic stem cells after non-myeloablative conditioning: a cellular therapeutic approach to hematologic and genetic diseases

Originally, allogeneic hematopoietic stem cell transplantation (HSCT) was viewed as a form of rescue from the marrow lethal effects of high doses of chemo-radiotherapy used to both eradicate malignancy and to provide sufficient immunosuppression to ensure allogeneic engraftment. Clear evience of a therapeutic graft-versus-tumor (GVT) effect mediated by allogeneic affector cells (T cells) has prompted the exploration of HSCT regimens that rely solely upon host immunosuppression (non-myeloblative) to facilitate allogenic donor engraftment. The engrafted donor effector cells are then used to accomplish the task of eradicating host malignant cells. The non-myeloblative regimen developed in Seattle uses 2 Gy total body irradiation (TBI) before transplant followed by postgrafting cyclosporine (CSP) and mycophenolate mofetil (MMF). This regimen resulted in initial mixed donor-host chimerism in all patients with hematologic malignancies and genetic disorders who received HLA-matched sibling allografts. The 17% incidence of graft rejection was reduced to 3% with the addition of fludarabine, 30 mg/m²/day on d-4,-3, and-2. The non-myeloblative combination of fludarabine/TBI has also been successful at achieving high engraftment rates in recipients of 10 of 10 HLA antigen matched unrelated donor HSCTs in patients with hematologic malignancies. By reducing acute toxicities relative to conventional HSCT, most patients have received their pre- and post-HSCT therapy almost exclusively as outpatients. Acute and chronic GVHD occur after non-myeloablative HSCT, but the incidence and severity appear less compared to conventional HSCT. As in conventional transplants, immune dysregulation from GVHD and its treatment and delayed reconstitution of immune function continue to present risks to patients who have otherwise undergone successful non-myeloablative HSCT. Cellular therapeutic effects have been nobserved after non-myeloblative HSCT such as correction of inherited genetic disorders, and eradication of hematologic malignant diseases and renal cell carcinoma via GVT responses.     

The infrapyloric artery and cephalic pancreatoduodenectomy with pylorus preservation: preliminary study

Summary Cephalic pancreatoduodenectomy (CPD) with pylorus preservation has been suggested to improve the functional and nutritional result of surgery. At operation, the first two centimeters of the duodenum are preserved, the vascular arch of the lesser gastric curvature is saved and the right gastroepiploic artery is resected at its origin. The aim of this study on 15 fresh cadavers was to determine the origin of the vascularization of the remaining duodenum and also the possibilities of preserving an optimal vascularization after CPD and pylorus preservation. All of the arteries supplying the remaining duodenum and arising either from the right gastric artery or the right gastroepiploic artery were identified. The distances between the origin of the infrapyloric artery and the termination of the gastroduodenal artery on the cranial and ventral pancreaticoduodenal artery and the left gastroepiploic artery were measured. At CPD with pylorus preservation, the study demonstrated that: 1) the cranial side of the remaining duodenum remains vascularized in 80% of the cases by one or two supraduodenal branches coming from the right gastric artery; 2) ligation of the right gastroepiploic artery eliminates all vascular supply to the caudal side of the remaining duodenum in almost half of the cases; 3) in these cases, the dissection of the bifurcation of the gastroduodenal artery and the vascular section beyond the origin of the infrapyloric artery allowed a direct vascular supply to the remaining duodenum to be preserved.This work was presented at the French Section of the European Association of Clinical Anatomy meeting, Bobigny, France, 1992