A case of unprovoked venous thromboembolism in a marathon athlete presenting atypical sequelae: What are the chances?

Marathon runners are exposed to multiple thrombogenic risk factors including dehydration and hemoconcentration, injury and inflammation, long-distance travel between events, and contraceptive usage. However, despite awareness about thromboembolism and several case reports detailing life-threatening hypercoagulopathies in athletes, the prevalence of venous thromboembolism in marathon runners remains uncharted. There is a lack of data and evidence-based guidelines for these athletes and for healthcare providers, including general medical practitioners and sports physicians. We present an episode of unprovoked deep vein thrombosis (DVT) and pulmonary embolism (PE) in a female marathon athlete who presented with atypical sequelae over the course of 8 months, and identify some "easy-to-miss" warning signs and symptoms. Through dialogue with the patient regarding their personal questions and anxieties surrounding idiopathic DVT-PE, we identify a clear need for more accessible information and comprehensive research concerning the detection, prevalence, and long-term management of venous thromboembolism in athletes. We discuss the possibility that being an athlete might constitute a more significant risk factor for venous thromboembolism than is currently estimated by commonly used diagnostic protocols and conclude that there is quite possibly a need for more specific clinical guidelines for athletes in this area.

Mutation frequency and type during ageing in mouse seminiferous tubules.

Mutations arise in the germline by errors of replication, recombination and repair, and the movement of transposable elements. Transgenic mice bearing reporter genes such as lacZ have proven useful for measurements of spontaneous and induced mutation frequencies, as well as studies of the effects of ageing. In this study, testicular DNA from lacZ transgenic mice was examined for age-related effects on mutation frequency and type. The recovered transgene was tested for simple substitutions and rearrangements including transposition of endogenous mobile elements. There was no evidence for either an age-related accumulation of mutations, or for the insertion of retrotransposons into the lacZ reporter gene in the testis. We conclude that the frequency of retrotransposition of several mouse mobile elements into the lacZ reporter gene is less than 3.73x10(-8). This is significantly less than the known frequency of approximately 7% of all spontaneous mutations in the mouse being due to retrotransposition of these elements.

Rapid accumulation of genome rearrangements in liver but not in brain of old mice.

Somatic mutations have long been considered a possible cause of ageing. To directly study mutational events in organs and tissues of ageing mammals, a transgenic mouse model has been generated that harbours lacZ reporter genes as part of chromosomally integrated plasmids. Using this model, we determined spontaneous mutant frequencies and spectra in mouse liver and brain as a function of age. In the liver, mutant frequencies increased with age from birth to 34 months; in the brain, an increase was observed only between birth and 4-6 months. Molecular characterization of the mutations showed that a substantial portion involved genome rearrangement events, with one breakpoint in a reporter gene and the other in the mouse flanking sequence. In the liver, these genome rearrangements did not increase with age until after 27 months, when they increased rapidly. In brain, the frequency of genome rearrangements was lower than in liver and did not increase with age.

Establishing a nurse-managed center: a community approach.

Documentation of need, designing and implementing services to meet the need, networking with and referral to other community providers, practice agreements, and mechanisms for reimbursement and billing are just a few issues that must be addressed when establishing a community-based health care unit. This article will discuss essentials of establishing a nurse-managed, community-based health care center, based on the author's experience in developing and managing the Outreach Health Care Unit.

Pathologic correlates of prognosis in lymph node-positive breast carcinomas.

BACKGROUND: Many pathologic features of breast carcinomas have been proposed as prognostic correlates; their interrelationships and their relative value as prognostic indicators were studied. METHODS: A series of 399 axillary lymph node-positive infiltrating ductal breast carcinomas was studied histologically and compared with the patient prognosis. RESULTS: Many pathologic findings fit into two groups of closely related features--those related to the extent of local spread and those related to histologic anaplasia and mitotic count. Both groups correlated with the primary tumor size. The best predictors of long-term survival were measures of the extent of axillary metastasis (the number of axillary metastases, the size of the largest metastasis, and lymph node capsular invasion), which are components of the pathologic node stage. The mitotic count, tumor grade, primary tumor stage, smooth tumor border, tumor necrosis, and multifocal primary tumors were weaker but significant survival correlates. The mitotic count and Bloom-Richardson grade best predicted the survival time of patients with node-positive disease who died. Four years after diagnosis, less than 25% of the patients who would die of breast carcinoma in the low mitotic count and Bloom-Richardson Grade 1 (well differentiated) groups already had died; more than 75% of those in the high mitotic count and Bloom-Richardson Grade 3 (poorly differentiated) groups already had died. Among patients with small tumors (< 1.8 cm in diameter), those with one micrometastasis (1-2 mm) had a worse prognosis than those with uninvolved lymph nodes of similar size. CONCLUSION: The extent of axillary metastasis best predicted the long-term prognosis of patients with infiltrating ductal carcinoma and axillary metastases. The mitotic count and tumor grade best predicted the survival time of those who died.