Interleukin-3 and interleukin-7 are alternative growth factors for the same B-cell precursors in the mouse

Clones and lines of precursor (pre) B cells can be established by limiting dilutions of unseparated cell suspensions of fetal liver or bone marrow on stromal cells in the presence of interleukin (IL)-7. When IL-3 is used instead of IL-7, cultures are regularly overgrown by different precursor cells of the myeloid lineage, as well as by adherent cells that inhibit pre-B-cell expansion. However, in the presence of either IL-7 or IL-3, clones of pre-B cells can be established on stroma cells at frequencies near one in one when the cultures are initiated with cell sorter purified CD45RO (B220)+/c-kit+ fetal liver or bone marrow derived pre-B cells. Clones grown on stromal cells in the presence of IL-7 can be regrown in IL-3, and vice versa. Pre-B cells that proliferate on stromal cells in the presence of IL-7 or IL-3 have the same phenotype, ie, are B220+ c-kit+, CD43+, and surrogate light chain+. Removal of the growth factors (IL-7, respectively IL-3) from the cultures results in differentiation to surface immunoglobulin (slg) positive, c-kit-, CD43-, surrogate light chain- B cells, a fraction of which is lipopolysaccharide (LPS) responsive as shown by IgM secretion. These results show that IL-7 and IL-3 stimulate largely overlapping populations of precursor B cells from bone marrow to proliferate for long periods of time in the presence of stromal cells. Thus, IL-7 and IL-3 are alternative growth factors for the same pre-BI cell.     

Raltegravir is a substrate for SLC22A6: a putative mechanism for the interaction between raltegravir and tenofovir

The identification of transporters of the HIV integrase inhibitor raltegravir could be a factor in an understanding of the pharmacokinetic-pharmacodynamic relationship and reported drug interactions of raltegravir. Here we determined whether raltegravir was a substrate for ABCB1 or the influx transporters SLCO1A2, SLCO1B1, SLCO1B3, SLC22A1, SLC22A6, SLC10A1, SLC15A1, and SLC15A2. Raltegravir transport by ABCB1 was studied with CEM, CEM(VBL100), and Caco-2 cells. Transport by uptake transporters was assessed by using a Xenopus laevis oocyte expression system, peripheral blood mononuclear cells, and primary renal cells. The kinetics of raltegravir transport and competition between raltegravir and tenofovir were also investigated using SLC22A6-expressing oocytes. Raltegravir was confirmed to be an ABCB1 substrate in CEM, CEM(VBL100), and Caco-2 cells. Raltegravir was also transported by SLC22A6 and SLC15A1 in oocyte expression systems but not by other transporters studied. The K(m) and V(max) for SLC22A6 transport were 150 μM and 36 pmol/oocyte/h, respectively. Tenofovir and raltegravir competed for SLC22A6 transport in a concentration-dependent manner. Raltegravir inhibited 1 μM tenofovir with a 50% inhibitory concentration (IC(50)) of 14.0 μM, and tenofovir inhibited 1 μM raltegravir with an IC(50) of 27.3 μM. Raltegravir concentrations were not altered by transporter inhibitors in peripheral blood mononuclear cells or primary renal cells. Raltegravir is a substrate for SLC22A6 and SLC15A1 in the oocyte expression system. However, transport was limited compared to endogenous controls, and these transporters are unlikely to have a great impact on raltegravir pharmacokinetics.     

Induction of ovulation with purified urinary follicle-stimulating hormone in patients with polycystic ovarian syndrome

Purified urinary follicle-stimulating hormone was used to induce ovulation in 18 patients with polycystic ovarian syndrome. Each ampule contained 75 IU of follicle-stimulating hormone and less than 0.11 IU of luteinizing hormone. Initial doses were 150 to 225 IU/day, later increased to a maximum of 375 IU, according to daily clinical controls and estradiol values. After 12 to 16 days, follicle-stimulating hormone treatment was suspended. Within 36 to 48 hours each patient received 5000 or 10,000 IU of human chorionic gonadotropin, rarely more. Ovulation occurred in 39 of 43 treatment cycles and hyperstimulation in nine. Seven patients had normal pregnancies with viable fetuses, including one pair of twins. Two had abortions. Analysis of the endocrine situation during therapy does not permit either pregnancy or hyperstimulation to be predicted. However, hyperstimulation is frequently accompanied by endogenous luteinizing hormone peaks and greater estradiol increases during the final phase of induction. Purified follicle-stimulating hormone has thus demonstrated its validity in inducing ovulation in patients with polycystic ovarian syndrome, apparently with equal or lower risks of hyperstimulation than with other gonadotropin preparations.     

The impact of late acute rejection after cadaveric kidney transplantation

BACKGROUND: Acute graft rejection (AR) following renal transplantation results in reduced graft survival. However, there is uncertainty regarding the definition, aetiology and long-term graft and patient outcome of AR occurring late in the post-transplant period. AIM: To determine if rejection episodes can be classified by time from transplantation by their impact on graft survival into early acute rejection (EAR) and late acute rejection (LAR). MATERIALS AND METHODS: 687 consecutive adult renal transplant recipients who received their first cadaveric renal transplant at a single centre. All received cyclosporine (CyA)-based immunosuppression, from 1984 to 1996, with a median follow-up of 6.9 yr. Details were abstracted from clinical records, with emphasis on age, sex, co-morbid conditions, HLA matching, rejection episodes, patient and graft survival. ANALYSIS: Patients were classified by the presence and time to AR from the date of transplantation. Using those patients who had no AR (NAR) as a baseline, we determined the relative risk of graft failure by time to rejection. The characteristics of patients who had no rejection, EAR and LAR were compared. RESULTS: Compared with NAR, the risk of graft failure was higher for those patients who suffered a rejection episode. A much higher risk of graft failure was seen when the first rejection episode occurred after 90 d. Thus, a period of 90 d was taken to separate EAR and LAR (relative risk of 3.06 and 5.27 compared with NAR as baseline, p<0.001). Seventy-eight patients (11.4%) had LAR, 271 (39.4%) had EAR and 338 (49.2%) had NAR. The mean age for each of these groups differed (LAR 39.6 yr, EAR 40.8 yr compared with NAR 44 yr, p<0.003). The 5-yr graft survival for those who had LAR was 45% and 10-yr survival was 28%. HLA mismatches were more frequent in those with EAR vs. NAR (zero mismatches in HLA-A: 36 vs. 24%, HLA-B: 35 vs. 23% and HLA-DR: 63 vs. 41%, p<0.003). There was no difference in mismatching frequency between NAR and LAR. CONCLUSIONS: AR had a deleterious impact on graft survival, particularly if occurring after 90 d. AR episodes should therefore be divided into early and late phases. In view of the very poor graft survival associated with LAR, it is important to gain further insight into the main aetiological factors. Those such as suboptimal CyA blood levels and non-compliance with medication should be further investigated with the aim of developing more effective immunosuppressive regimens in order to reduce the incidence of LAR.     

The Effect of Surgical Weight Reduction on Functional Status in Morbidly Obese Patients with Low Back Pain

Background: Although low back (LBP) pain is not a lifethreatening disease, it is a source of significant discomfort and disability and accounts for work absences. It has been shown previously that morbid obesity is associated with increased frequency of LBP and that surgical weight loss improves the symptomatology. However, there are no studies to quantitatively assess the exact degree of functional disability caused by severe obesity and the degree of improvement of LBP that follows weight loss from bariatric surgery. Methods: 29 morbidly obese candidates for bariatric surgery with LBP, weight 132.5±27 (mean±SD) kg and BMI 47.2±8.8 kg/m² were examined for their functional status using psychometric instruments specifically designed to objectively assess the patients' complaints. The preoperative scores were measured by a) visual analogue scales (VAS1, VAS2, VAS3), b) Roland-Morris disability questionnaire, c) Oswestry LBP disability questionnaire, and d) Waddell disability index, and were compared with the scores obtained by the same instruments 2 years after vertical banded gastroplasty. Results: The postoperative weight (92.3±19 kg) and BMI (32.9±6.3 kg/m²) of the 29 patients were significantly reduced (P<0.001). The improved functional disability scores were statistically significant: a) VAS1 1.59±1.86 (mean±SD) vs 0.32±0.64, P<0.001; b) VAS2 5.5±1.97 vs 2.14±1.88, P<0.001; c) VAS3 0.77±1.11 vs 0.09±0.29, P=0.006, d) Roland-Morris 7.89±5.11 vs 1.89±2.13, P<0.001; e) Oswestry 21.22±15.63 vs 5.61±7.51, P<0.001; f) Waddell 2.81±1.37 vs 0.56±0.72, P<0.001. Conclusions: Surgical weight loss significantly improves the degree of functional disability of morbidly obese patients suffering from LBP.     

Antigen-driven C–C Chemokine-mediated HIV-1 Suppression by CD4+ T Cells from Exposed Uninfected Individuals Expressing the Wild-type CCR-5 Allele

Despite repeated exposure to HIV-1, certain individuals remain persistently uninfected. Such exposed uninfected (EU) people show evidence of HIV-1–specific T cell immunity and, in rare cases, selective resistance to infection by macrophage-tropic strains of HIV-1. The latter has been associated with a 32–base pair deletion in the C–C chemokine receptor gene CCR-5, the major coreceptor of macrophage-tropic strains of HIV-1. We have undertaken an analysis of the HIV-specific T cell responses in 12 EU individuals who were either homozygous for the wild-type CCR-5 allele or heterozygous for the deletion allele (CCR-5Δ32). We have found evidence of an oligoclonal T cell response mediated by helper T cells specific for a conserved region of the HIV-1 envelope. These cells produce very high levels of C–C chemokines when stimulated by the specific antigen and suppress selectively the replication of macrophage-tropic, but not T cell–tropic, strains of HIV-1. These chemokine-producing helper cells may be part of a protective immune response that could be potentially exploited for vaccine development.