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.

Ischemic preconditioning improved peak and mean power output during the early stages of repeated sprint cycling and may be beneficial for sprint sports.

SummaryThis paper reports our experience in monitoring gentamicin therapy during the treatment of 68 episodes of serious Gramnegative sepsis in 65 hospital patients. Most of the patients had major underlying disease. Of those who were adequately treated (peak serum concentrations of 5 ,ug/ml or more in 72 hours for septicaemia, urinary tract infection, and wound infection; and 8 ,ug/ml or more at some time during the course of treatment for pneumonia) B4% (46 out of 55) were cured. These serum concentrations could be achieved only by starting with a regimen of 5 mg/kg/day in three divided doses in ali adult patients, subsequent dosage being determined by the results of rapid serum assay. The incidence of nephrotoxicity and symptomatic ototoxicity was no greater than in previous series. The main reason for assaying serum gentamicin is to ensure that an adequate dosage is achieved as soon as possible. In patients with impaired renal function or receiving prolonged high dosage assays also serve to guard against an excessive accumulation of gentamicin and an increased risk of toxicity.

Infection of normal individuals with human parvovirus (B19) results in a mild disease (erythema infectiosum) but gives rise to aplastic crises in patients with chronic hemolytic anemias. The effects of this disease on hemopoiesis were investigated following intranasal inoculation of the virus into three volunteers. A typical disease ensued with a viremia peaking at 9 d. Marrow morphology 6 d after inoculation appeared normal but at 10 d there was a severe loss of erythroid precursors followed by a 1-2-g drop in hemoglobin, and an increase in serum immunoreactive erythropoietin. Erythroid burst-forming units (BFU-E) from the peripheral blood were considerably reduced, starting at the time of viremia and persisting for 4-8 d depending on the individual. Granulocyte-macrophage colony-forming units (CFU-GM) were also affected but the loss started 2 d later. Both CFU-GM and BFU-E showed a sharp overshoot at recovery. In the marrow, BFU-E and CFU-E were reduced at 6 and 10 d in the individual having the longest period of peripheral progenitor loss. In contrast, there was an increase in BFU-E and CFU-E in the subject with least change in peripheral progenitors. In the third subject, with an intermediate picture, there was a loss at 6 d but an increase at 10 d of erythroid progenitors. It is suggested that the architecture of the marrow might partially isolate progenitors from high titers of virus in the serum and individual variation in this respect might give the results observed.