Characterization of a relatively rare class B, type 2 trypanosome variant surface glycoprotein gene

We have examined the capacity of peripheral blood T cells from RA patients to be polarized in vitro towards a type 1 (T1) or a type 2 (T2) phenotype. Peripheral blood T cells from RA patients and from healthy donors were primed by 1 week of culture with soluble OKT3 in the presence of polarizing cytokines. The recovered T cells were restimulated and their cytokine secretion profile determined. Priming of T cells from RA patients in the presence of recombinant (r)IL-2 plus rIL-12 induced a shift towards a TI pattern, characterized by increased production of interferon-gamma, that was more pronounced than in the case of healthy donors. Conversely, priming of T cells from RA patients in the presence of IL-4 failed to induce a shift towards a T2 profile after 1 week, whereas it induced T cells from healthy donors to acquire such a profile characterized by heightened production of IL-4, IL-5 and IL-13. However, a T2 polarization profile emerged in T cells from RA patients that were primed in the presence of rIL-4 and subsequently maintained in culture in rIL-2 alone for 1 or 2 additional weeks. We conclude that in vitro differentiation of peripheral T cells towards a type 2 phenotype is impaired in RA. Nevertheless, conditions required to drive peripheral T cells towards a type 2 phenotype were established. Administration of autologous polyclonal T cells expressing a type 2 cytokine secretion profile is proposed as a therapeutic strategy in RA.     

Impaired clearance of emboli (washout) is an important link between hypoperfusion, embolism, and ischemic stroke

OBJECTIVE: To explore the relationship between hypoperfusion, embolism, and brain infarction. DESIGN: We studied 4 situations in which brain infarction is related to hypoperfusion: extracranial and intracranial occlusive vascular disease, reduced functional vascular reserve in patients with carotid artery occlusive disease, reduced collateral blood flow in patients given thrombolytic treatment, and cardiac surgery. We reviewed results of emboli monitoring using transcranial Doppler ultrasonography. RESULTS: Hypoperfusion is strongly linked to brain ischemia and infarction. The evidence includes close correlation of (1) the severity of arterial stenosis with brain infarction; (2) impaired functional blood flow reserve in patients with carotid artery disease and subsequent brain infarction; (3) reduced collateral blood flow with poor prognosis after thrombolysis; and (4) stroke-related neurologic deficits after cardiac surgery to hypoperfusion during surgery. Microembolization is common in patients with severe symptomatic carotid artery stenosis and during and after cardiac surgery. CONCLUSIONS: Hypoperfusion and embolism often coexist and their pathophysiological features are interactive. Arterial lumenal narrowing and endothelial abnormalities stimulate clot formation and subsequent embolization. Reduced perfusion limits the ability of the bloodstream to clear or wash out emboli and microemboli and reduces available blood flow to regions rendered ischemic by emboli that block supply arteries. The brain border zones are a favored destination for microemboli that are not cleared. We posit that impaired washout is an important but neglected concept that intertwines hypoperfusion, embolization, and brain infarction.     

Differential binding of estradiol and testosterone to SHBG. Relation to circulating estradiol levels

OBJECTIVE: Sex hormone-binding globulin (SHBG) binds testosterone (T) to a greater degree than it does estradiol (E2), acting as an amplifier of E2 action. However, it is not known whether the relative capacity of SHBG for E2 vs. T is altered by the hormonal milieu. We hypothesized that an increase in circulating E2 levels results in a compensatory increase in the relative binding capacity of SHBG for these hormones, dampening the E2 amplification effect in hyperestrogenic conditions. STUDY DESIGN: Retrospective. RESULTS: As expected, during hMG stimulation there was a significant increase in total and free E2 (28 to 1,986 pg/mL, P < .001; and 0.3 to 20.8 pg/mL, P < .001, respectively) and total T levels (40.3 vs. 78.3 ng/dL, P < .001) from basal to late stimulation. Free T levels increased, but the difference did not reach significance. The binding capacity of SHBG for both E2 and T increased in a proportional manner (980 +/- 340 vs. 1,434 +/- 449 nmol/L, P < .009; and 352 +/- 190 vs. 512 +/- 128 nmol/L, P < .02; respectively) since the ratio of SHBG binding to E2 and T was unchanged. Although the SHBG molar concentration appeared increased, the difference did not reach significance (821 +/- 542 to 1,099 +/- 254 nmol/L). CONCLUSION: A short-term, although profound, increase in circulating E2 does not seem to be associated with an increase in the relative binding capacity of the carrier protein for either E2 or T, although an overall increase in binding for both steroids was observed. It is possible that longer periods of exposure to E2 may be necessary to demonstrate a change in the differential binding of this carrier protein with an alteration in the hormonal milieu.     

Serologic test for syphilis as a surrogate marker for human immunodeficiency virus infection among United States blood donors

OBJECTIVE: To determine the presence of tricuspid regurgitation (TR) in patients affected by acute lung injury (ALI) and the adult respiratory distress syndrome (ARDS) during mechanical ventilation with positive end-expiratory pressure (PEEP). DESIGN: A prospective clinical study. SETTING: 10-bed general intensive care unit in a University Hospital. PATIENTS: 7 consecutive patients an age 44.7 +/- 8.6 years with a diagnosis of ALI or ARDS were studied. All were on mechanical ventilation with PEEP. INTERVENTIONS: PEEP was increased in steps of 5 cm H2O until the appearance of TR or up to a limit of 20 cm H2O. MEASUREMENTS AND RESULTS: Right atrial pressure, pulmonary artery pressure, and wedge pressure were measured and cardiac output was determined by thermodilution. TR was graded from 0 to 3. Standard 2D echocardiographic and pulsed-wave images were obtained at each level of PEEP. PEEP was increased from 4 +/- 3 to 17 +/- 2 cm H2O. Mean PAP increased from 27.7 +/- 2.9 to 36.7 +/- 3.5 mm Hg (p < 0.02) when PEEP was increased. Five patients had competent valves and two had mild TR at baseline. In six out of the seven, TR either developed or increased when PEEP was increased. CONCLUSIONS: Our study demonstrated the development of TR after the use of PEEP in patients with ALI and ARDS as a consequence of pulmonary hypertension and right ventricular overloading. Since TR may randomly affect cardiac output values and derived parameters, the assessment of cardiac performance by some techniques such as thermodilution should be used with caution.     

Physician practice management companies

Physicians are increasingly courted by insurers and hospitals as partners for integrated delivery systems. A new integrative option has emerged for physicians--the physician practice management company (PPMC). PPMCs have formed in response to several supply and demand factors. They hold out great promise for physicians, but closer scrutiny suggests that this promise has not yet been realized. PPMCs warrant managerial and research attention due to their contracting potential as physician networks in dealing with employers and payers.