Healthy adult volunteers were inoculated intranasally with human parvovirus obtained from an asymptomatic blood donor. One week after inoculation, intense viremia was observed in seronegative volunteers, accompanied by a mild illness with pyrexia, malaise, myalgia, itching, and excretion of virus from the respiratory tract. In the following week hematologic studies revealed reticulocytopenia with an associated slight drop in hemoglobin concentration, lymphopenia, neutropenia, and a drop in platelet counts. At 17-18 days after inoculation a second-phase illness with rash and arthralgia lasting three to four days occurred in three of four infected volunteers. This study confirms the etiologic role of human parvovirus in erythematous rash illness, with the second-phase illness being consistent with adult cases of erythema infectiosum. Moreover, the hematologic changes associated with infection support the hypothesis that the same virus is responsible for the temporary arrest of erythropoiesis that leads to aplastic crisis in persons with chronic hemolytic anemia.

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Gastrointestinal lymphoma is an uncommon disease but is the most frequently occurring extranodal lymphoma and is almost exclusively of non-Hodgkin type. Primary gastrointestinal lymphoma most commonly involves the stomach but can involve any part of the gastrointestinal tract from the esophagus to the rectum. Risk factors for the development of gastrointestinal lymphoma include Helicobacter pylori infection, immunosuppression after solid organ transplantation, celiac disease, inflammatory bowel disease, and human immunodeficiency virus infection. Although gastrointestinal lymphoma has a wide variety of imaging appearances and definitive diagnosis relies on histopathologic analysis, certain findings (eg, a bulky mass or diffuse infiltration with preservation of fat planes and no obstruction, multiple site involvement, associated bulky lymphadenopathy) can strongly suggest the diagnosis. Imaging also plays an important role in the detection of complications such as perforation, obstruction, and fistulization. The most commonly used imaging modalities are barium examination and computed tomography (CT). These modalities are complementary, although CT provides a better overall assessment of the disease stage.

The ability to repeatedly produce a high-power output or sprint speed is a key fitness component of most field and court sports. The aim of this study was to evaluate the validity and reliability of eight different approaches to quantify this parameter in tests of multiple-sprint performance. Ten physically active men completed two trials of each of two multiple-sprint running protocols with contrasting recovery periods. Protocol 1 consisted of 12 x 30-m sprints repeated every 35 seconds; protocol 2 consisted of 12 x 30-m sprints repeated every 65 seconds. All testing was performed in an indoor sports facility, and sprint times were recorded using twin-beam photocells. All but one of the formulae showed good construct validity, as evidenced by similar within-protocol fatigue scores. However, the assumptions on which many of the formulae were based, combined with poor or inconsistent test-retest reliability (coefficient of variation range: 0.8-145.7%; intraclass correlation coefficient range: 0.09-0.75), suggested many problems regarding logical validity. In line with previous research, the results support the percentage decrement calculation as the most valid and reliable method of quantifying fatigue in tests of multiple-sprint performance.