Interleukin-2 (IL-2) receptor alpha, beta and gamma subunit expression as a function of B-cell lineage ontogeny: the use of IL-2-PE66(4Glu) to characterize internalization via IL-2 receptor subunits

Interleukin-2 (IL-2) is a pluripotent cytokine which plays a crucial role in the immune system response. Although the IL-2/IL-2 receptor (IL-2R) system has been well characterized in cells of the T lineage it is less known in B lymphocytes. The authors therefore studied the expression of the IL-2R alpha, beta and gamma subunits in human B-cell lines at different stages of maturation, by the polymerase chain reaction technique. The authors found that the alpha and beta subunits are expressed in the final stages of B-cell lineage maturation, whereas the gamma subunit is constitutively expressed during B-lymphocyte differentiation. The results indicate that the IL-2/IL-2R system, most probably, does not have a role in the early stages of B-cell differentiation, but may be involved only in the final stages of B-cell lineage ontogeny. Moreover, the ability of the different forms of IL-2R to internalize the IL-2 ligand was investigated, using the chimeric protein IL-2-PE66(4Glu). Cell lines bearing the alphagamma, betagamma and alpha betagamma forms of IL-2R were inhibited by the chimeric protein, while those bearing the gamma subunit alone did not respond to the chimera. Thus, internalization of IL-2 is most likely mediated via the alphagamma form of the IL-2R, as shown here for the first time, as well as through the betagamma and alpha betagamma IL-2R forms. However, IL-2 cannot be internalized through the IL-2R gamma subunit alone.

Ocular distribution of the chimeric protein IL2-PE40

A construct of IL-2 and pseudomonas exotoxin (PE40) has been genetically engineered. An aliquot of 100 microliter of the chimeric protein, radiolabelled with I125, was administered to healthy rats by various routes. At different intervals, ocular and non ocular tissues were removed and the levels of the radiolabelled chimeric protein IL-2-PE40 measured. Systemic administration of IL2-PE40 either intravenously (IV) or intraperitoneally (IP) leads to high levels of the drug in the blood, liver and spleen. Little or no radioactivity is observed within the ocular tissues using this route. On the other hand, local administration of the drug either as subtenon injection or as eye drops resulted in a very high concentration of the drug within the conjunctiva, cornea and sclera, with little radioactivity detected systemically. Subtenon injection induced a significant drug level within the optic nerve. With the drops, the chimeric protein was also detected, in low levels, intraocularly.

Bladder rupture associated with pelvic fracture due to blunt trauma

A total of 103 patients with pelvic fracture due to blunt trauma were evaluated by cystography and 10 cases of bladder rupture were identified. Risk factors associated with the likelihood of bladder rupture included gross hematuria, the number of fractured pubic rami, tachycardia, hypotension, and declining hematocrit. We conclude that since 90 percent of the patients do not have bladder rupture when a pelvic fracture is encountered, cystography may be safely reserved for those patients with pelvic fracture who are considered to be at high risk for such an injury.

Renal aspergilloma: an unusual cause of infection in a patient with the acquired immunodeficiency syndrome

The case of a 36-year-old man with the acquired immunodeficiency syndrome (AIDS) and a renal aspergilloma is reported. Aspergillus infections are uncommon in patients with AIDS. Isolated renal aspergillomas have rarely been reported in the non-AIDS population (14 cases) and have never been reported in a patient with AIDS. The patient we describe was clinically symptomatic and initially treated medically, but he did not respond to intravenous amphotericin and oral itraconazole. He eventually required nephrectomy; however, there was local recurrence of the aspergilloma postoperatively. We comment on some issues in the spectrum of Aspergillus infections in AIDS and review the literature on the manifestations and treatment of renal aspergillomas.

Maternal cocaine use and infant behavior

We hypothesized that prenatal cocaine exposure results in less optimal infant behavior and more impaired maternal-infant interaction in healthy term infants. Infants were evaluated with the Neonatal Behavioral Assessment Scale (NBAS) at days 1-3 and 11-30 of age, and mother-infant pairs with the Nursing Child Assessment of Feeding Scale (NCAFS) at 7-16 weeks of age. Drug use was determined from confidential interviews, urine assays and medical records. Cocaine-exposed infants (N = 51) were no different than unexposed comparison infants (N = 60) on the first NBAS exam. On the second NBAS exam, 20 cocaine-exposed infants had slightly lower motor cluster scores compared with those of 32 unexposed infants (p = 0.01), but this difference was reduced after control for several confounding variables. The NCAFS detected no differences between groups in maternal or infant behavior. Infants in this population showed no clinically meaningful effects of cocaine exposure on behavior or maternal-infant interaction.