Anterior cruciate ligament ganglion: case report.
CONTEXT: A ganglion is a cystic formation close to joints or tendinous sheaths, frequently found in the wrist, foot or knee. Intra-articular ganglia of the knee are rare, and most of them are located in the anterior cruciate ligament. The clinical picture for these ganglia comprises pain and movement restrictions in the knee, causing significant impairment to the patient. Symptoms are non-specific, and anterior cruciate ligament ganglia are usually diagnosed through magnetic resonance imaging or arthroscopy. Not all ganglia diagnosed through magnetic resonance imaging need to undergo surgical treatment: only those that cause clinical signs and symptoms do. Surgical results are considered good or excellent in the vast majority of cases. CASE REPORT: A 29-year-old male presented with pain in the left knee during a marathon race. Physical examination revealed limitation in the maximum range of knee extension and pain in the posterior aspect of the left knee. Radiographs of the left knee were normal, but magnetic resonance imaging revealed a multi-lobed cystic structure adjacent to the anterior cruciate ligament, which resembled a ganglion cyst. The mass was removed through arthroscopy, and pathological examination revealed a synovial cyst. Patient recovery was excellent, and he resumed his usual training routine five months later. (+info)
A locus on mouse chromosome 6 that determines resistance to herpes simplex virus also influences reactivation, while an unlinked locus augments resistance of female mice.
During studies to determine a role for tumor necrosis factor (TNF) in herpes simplex virus type 1 (HSV-1) infection using TNF receptor null mutant mice, we discovered a genetic locus, closely linked to the TNF p55 receptor (Tnfrsf1a) gene on mouse chromosome 6 (c6), that determines resistance or susceptibility to HSV-1. We named this locus the herpes resistance locus, Hrl, and showed that it also mediates resistance to HSV-2. Hrl has at least two alleles, Hrl(r), expressed by resistant strains like C57BL/6 (B6), and Hrl(s), expressed by susceptible strains like 129S6 (129) and BALB/c. Although Hrl is inherited as an autosomal dominant gene, resistance to HSV-1 is strongly sex biased such that female mice are significantly more resistant than male mice. Analysis of backcrosses between resistant B6 and susceptible 129 mice revealed that a second locus, tentatively named the sex modifier locus, Sml, functions to augment resistance of female mice. Besides determining resistance, Hrl is one of several genes involved in the control of HSV-1 replication in the eye and ganglion. Remarkably, Hrl also affects reactivation of HSV-1, possibly by interaction with some unknown gene(s). We showed that Hrl is distinct from Cmv1, the gene that determines resistance to murine cytomegalovirus, which is encoded in the major NK cell complex just distal of p55 on c6. Hrl has been mapped to a roughly 5-centimorgan interval on c6, and current efforts are focused on obtaining a high-resolution map for Hrl. (+info)
A case of extensor digitorum brevis manus.
The extensor digitorum brevis manus (EDBM), a relatively rare anomalous muscle on the dorsal hand, may be misdiagnosed as a ganglion, a synovial nodule or cyst, or a soft-tissue tumor. MRI scans can help to distinguish EDBM from tumors. EDBM should be included in the differential diagnosis of soft tissue masses on the dorsal aspect of the hand. (+info)
Leiomyoma of the hand mimicking a pearl ganglion.
Leiomyomas rarely occur in the hand. To our knowledge, there have been no reports of a leiomyoma of the hand mimicking a pearl ganglion in the English literature. We report such a case with a leiomyoma of the right third finger in a 59-year-old woman. The tumor was excised together with the underlying sheet of tissue. The pathology revealed that the tumor was linked to the underlying structure of a vascular wall by a stalk of tumor tissue. This report serves to remind clinicians to include leiomyoma in the differential diagnosis when encountering a 'ganglion-like lesion'. Also, this report demonstrates the link between a leiomyoma and its underlying origin. (+info)
The role of Pax2 in mouse inner ear development.
The paired box transcription factor, Pax2, is important for cochlear development in the mouse inner ear. Two mutant alleles of Pax2, a knockout and a frameshift mutation (Pax21Neu), show either agenesis or severe malformation of the cochlea, respectively. In humans, mutations in the PAX2 gene cause renal coloboma syndrome that is characterized by kidney abnormalities, optic nerve colobomas and mild sensorineural deafness. To better understand the role of Pax2 in inner ear development, we examined the inner ear phenotype in the Pax2 knockout mice using paint-fill and gene expression analyses. We show that Pax2-/- ears often lack a distinct saccule, and the endolymphatic duct and common crus are invariably fused. However, a rudimentary cochlea is always present in all Pax2 knockout inner ears. Cochlear outgrowth in the mutants is arrested at an early stage due to apoptosis of cells that normally express Pax2 in the cochlear anlage. Lack of Pax2 affects tissue specification within the cochlear duct, particularly regions between the sensory tissue and the stria vascularis. Because the cochlear phenotypes observed in Pax2 mutants are more severe than those observed in mice lacking Otx1 and Otx2, we postulate that Pax2 plays a key role in regulating the differential growth within the cochlear duct and thus, its proper outgrowth and coiling. (+info)
Unusual localization of multiple myxoid (mucous) cysts of toes.
Myxoid cysts of fingers and toes are observed frequently on the lateral or dorsal aspects of the distal digits. They are usually solitary nodules. Both subungual localization and multiplicity are quite rare. We present a 74-year-old woman with digital subungual mucous cysts located on all toes. (+info)
Drosophila Grainyhead specifies late programmes of neural proliferation by regulating the mitotic activity and Hox-dependent apoptosis of neuroblasts.
The Drosophila central nervous system is generated by stem-cell-like progenitors called neuroblasts. Early in development, neuroblasts switch through a temporal series of transcription factors modulating neuronal fate according to the time of birth. At later stages, it is known that neuroblasts switch on expression of Grainyhead (Grh) and maintain it through many subsequent divisions. We report that the function of this conserved transcription factor is to specify the regionalised patterns of neurogenesis that are characteristic of postembryonic stages. In the thorax, Grh prolongs neural proliferation by maintaining a mitotically active neuroblast. In the abdomen, Grh terminates neural proliferation by regulating the competence of neuroblasts to undergo apoptosis in response to Abdominal-A expression. This study shows how a factor specific to late-stage neural progenitors can regulate the time at which neural proliferation stops, and identifies mechanisms linking it to the Hox axial patterning system. (+info)
Ganglion cyst of the anterior cruciate ligament: a case report.
A ganglion is a cystic swelling that usually arises close to tendons or joints. Its occurrence inside a joint is rare, and its diagnosis is usually incidental during magnetic resonance imaging or arthroscopy. It may be painful or asymptomatic. Some patients may have a trauma history. Ganglia may mimic intra-articular lesions like tears of the anterior cruciate ligament or meniscus. Magnetic resonance imaging is the investigation of choice for diagnosis. Ganglia commonly arise from the anterior cruciate ligament, but can also arise from other structures such as the posterior cruciate ligament or meniscus. Ganglia are typically treated by arthroscopic excision and debridement. We report a case of ganglion cyst of the anterior cruciate ligament in a 16-year-old man. (+info)