CD34+ progenitor cells from asymptomatic patients are not a major reservoir for human immunodeficiency virus-1

Controversy exists as to whether hematopoietic progenitor cells are infected by human immunodeficiency virus-1 (HIV-1) in vivo. Most studies have focused on patients with acquired immunodeficiency syndrome (AIDS)/AIDS-related complex, and little data are available on asymptomatic patients with well preserved CD4+ T-cell counts. To determine if CD34+ hematopoietic progenitor cells are infected early in the course of HIV-1 disease, we evaluated 10 asymptomatic HIV-1 seropositive (HIV-1+) patients. The CD34+ cell fraction was purified by a two-step procedure consisting of both affinity chromatography and fluorescence-activated cell sorting that resulted in a median purity of over 99%. Using conventional and nested polymerase chain reaction (PCR) assays, we evaluated the presence and frequency of HIV-1 proviral DNA. Both bone marrow mononuclear cells and CD34- cells from all 10 patients were strongly positive for the HIV-1 pol and/or gag gene sequences. In contrast, sorted CD34+ cells from only two of 10 patients were positive, and the number of copies of proviral DNA in these samples was estimated to be from 2 to 5 per 250,000 cells. To test the in vitro functional capacity of CD34+ progenitors, these cells were assayed in both methylcellulose and long-term stromal culture. We found no significant reduction in the number of colony-forming unit-erythroid (CFU-E), burst-forming unit-erythroid (BFU-E), or colony-forming unit- granulocyte macrophage (CFU-GM) colonies, or in the frequency of cobblestone area forming cells from limit dilution analysis in HIV-1+ asymptomatic patients. Pooled methylcellulose colonies generated from CD34+ cells were HIV-1- in nine of 10 samples. All progeny from long- term cultures of CD34+ cells were HIV-1-. We conclude that the CD34+ hematopoietic progenitor compartment is not infected in the majority of asymptomatic HIV-1+ patients, and that these cells may represent a suitable target for strategies designed to protect developing CD4+ T cells from infection.     

Acute mixed lineage leukemia: clinicopathologic correlations and prognostic significance

The frequency and clinical significance of acute leukemia displaying both lymphoid and myeloid characteristics was determined in 123 consecutive children using a panel of lineage-associated markers. The leukemic blasts from 18 of 95 children (19%) with the diagnosis of acute lymphoblastic leukemia (ALL) by standard diagnostic criteria expressed myeloid-associated cell surface antigens. Despite immunological evidence of lymphoid differentiation (17 CALLA + and one T cell-associated antigen +) and findings of immunoglobulin gene rearrangement, blasts from these patients reacted with one to five monoclonal antibodies identifying myeloid-associated cell surface antigens (My-1, MCS.2, Mo1, SJ-D1, or 5F1). Dual staining with microsphere-conjugated antibodies and analysis by flow cytometry confirmed that some blasts were simultaneously expressing lymphoid- and myeloid-associated antigens. Conversely, blasts from seven of 28 patients (25%) with acute nonlymphocytic leukemia (ANLL), diagnosed by otherwise standard morphological and cytochemical criteria, expressed lymphoid-associated surface antigens. Dual staining of individual blasts demonstrated simultaneous expression of myeloperoxidase (MPO) (including Auer rods) in association with either T-11, CALLA, or terminal deoxynucleotidyl transferase. Blasts from one patient with ANLL demonstrated T cell receptor gene rearrangement, while blasts from another patient demonstrated characteristics associated with T (T-11), B (CALLA and heavy-chain immunoglobulin gene rearrangement), and myeloid (MPO) lineage. There were no consistent cytogenetic abnormalities, and no patient demonstrated independent leukemic clones. Each patient with typical ALL, except for myeloid-associated antigens, achieved complete remission with conventional induction therapy for ALL. By contrast, three of the seven children with ANLL whose blasts expressed the T-11 surface antigen failed ANLL induction therapy. These three patients subsequently achieved remission with ALL therapy.     

Nephron-sparing partial nephrectomy for bilateral Wilms' tumor

PurposePartial nephrectomy is increasingly used in children with bilateral Wilms' tumor (BWT) or contralateral recurrence. Nephron-sparing surgery seeks to achieve complete tumor removal while preserving functional renal parenchyma. Previous series have documented high rates of complications, recurrence, and mortality.MethodsTwelve patients (4 boys and 8 girls aged 9-42 months) with BWT or contralateral recurrence were treated at our institution with unilateral or bilateral partial nephrectomy. Preoperative imaging, operative notes, and pathology reports were reviewed. Outcomes analyzed included complications, recurrence, readmission rate, postoperative glomerular filtration rate (GFR), and survival.ResultsAll patients underwent successful nephron-sparing resection using standard techniques, with only 2 patients requiring unilateral nephrectomy. Median length of stay was 3 days. There were no major complications or urine leaks. Two patients were lost to follow-up. The remaining 10 were followed up for a median of 36 months (range, 3-79 months). There have been no recurrences or unplanned readmissions. Mean GFR is 107.7 (±32.8) mL/min per 1.73 m², with no patient having a GFR below the lower limit of normal for age.ConclusionNephron-sparing resection is a safe and effective approach for children with BWT or contralateral recurrence and should be part of the multimodality therapeutic approach to this disease.     

L-selectin can mediate leukocyte rolling in untreated mesenteric venules in vivo independent of E- or P-selectin

Granulocyte recruitment during the acute inflammatory response is initiated by their rolling along the endothelial lining of postcapillary venules. To determine whether expression of L-selectin alone is sufficient for rolling, the murine pre-B lymphocytic cell line 300.19, which does not bind E- or P-selectin, was transfected with human L-selectin cDNA, which led to stable L-selectin expression at a level similar to that of blood lymphocytes. Fluorescent-labeled cells were infused retrogradely into a side branch of the superior mesenteric artery of anesthetized rats. In venules of the mesenteric membrane, leukocyte rolling occurs without intentional stimulation. On average, 17% +/- 6% of L-selectin transfectants rolled in the observed venules, while mock-transfected cells did not roll. Rolling of L-selectin transfectants began approximately 20 minutes after surgery and continued for at least 120 minutes. In contrast, HL-60 promyelocytes, which express sialyl-Lewis(x) tetrasaccharide (sLe(x)) but not L- selectin and that bind to E- and P-selectin in vitro, did not roll between 20 and 120 minutes, but some HL-60 cells rolled at very early (< 20 minutes) and late (> 2 hours) time points. Pretreatment with either of two function-blocking monoclonal antibodies recognizing the lectin domain of L-selectin completely blocked rolling of L-selectin transfectants and sharply reduced (by 70%) rolling of isolated human granulocytes. Taken together, these results show that L-selectin can mediate leukocyte rolling by virtue of its lectin activity.     

Clinical and laboratory characteristics of acute leukemia with the 4;11 translocation

This report describes the clinical and laboratory features of seven cases of acute leukemia associated with the 4;11 chromosomal translocation. All seven children had acute lymphoblastic leukemia by standard morphologic and cytochemical criteria. Leukemic blasts from six of seven patients were terminal deoxynucleotidyl transferase- positive. Immunologic phenotyping suggested the leukemias were of B cell origin; blasts from five patients expressed HLA-DR and p24 (CD-9 antibody), blasts from three patients expressed B4 (CD-19), and blasts from two patients expressed the common acute lymphoblastic leukemia antigen (CD-10). One patient's leukemic blasts contained cytoplasmic immunoglobulin. Analysis of DNA from four of five patients demonstrated additional evidence of B cell differentiation with heavy-chain immunoglobulin gene rearrangement. When DNA from the four patients with heavy-chain immunoglobulin gene rearrangement was analyzed, one patient's DNA demonstrated light-chain immunoglobulin gene rearrangement. However, flow cytometric analysis of blasts from three patients showed the simultaneous expression of the lymphoid-associated antigen B4 (CD-19) and the myeloid-associated antigen My-1 (X-Hapten). Electron microscopic examination of blasts from one patient that expressed both lymphoid- and myeloid-associated antigens demonstrated ultrastructural characteristics of both lineages. These findings suggest that acute leukemia with the t(4;11) abnormality has mixed lineage characteristics as a result of leukemogenesis in a multipotential progenitor cell or aberrant gene expression later in differentiation. Furthermore, serial analysis of karyotype, immunophenotype, and heavy-chain immunoglobulin genes revealed changes in these biologic markers over time, suggesting continued chromosome rearrangement and gene modulation after the leukemogenic event in cells with the t(4;11).     

Clinical prediction of post-extubation radiological changes of the chest in newborn infants

Objective: Whether a chest radiograph should be performed routinely in all infants after extubation, or selectively only in those with clinical deterioration, is a controversy in neonatal unit practice. This study tested the hypothesis that most cases of post-extubation radiological deterioration in the lungs could be detected by clinical assessment. Methods: A chest radiograph was performed at 8 h post-extubation in 100 episodes of extubation in 85 newborn infants ventilated for a variety of lung diseases. Each infant was assessed at the same time by a neonatologist blinded to the radiological findings, to determine whether a chest radiograph would have been requested based on clinical judgement. The infants were continuously monitored for their respiratory and oxygenation status before and after extubation. Results: Compared to the pre-extubation chest radiographs, 23 of the 100 post-extubation chest radiographs showed either deterioration of the pre-existing lung pathologies or appearance of significant new pathologies. The clinicians' assessment failed to detect most of the deterioration, with a sensitivity of only 21.7%. Systematic analysis of the infants' clinical parameters showed that the development of significant intercostal/subcostal retraction, and an increase in inspired oxygen concentration by ≥ 7% after extubation, were the best predictors of post-extubation radiological deterioration (sensitivity 82.6%, specificity 62.3%, positive predictive value 39.6%, and negative predictive value 92.3%). Serial blood gas in contrast had little predictive value. Conclusion: We conclude that most cases of radiological deterioration of the lungs after extubation are clinically predictable, provided the correct clinical criteria are used.     

海岛轮环藤碱-N-氧化物的制备和结构

Oxidation of insularine (Ⅰ) with m-chloroperbenzoic acid yielded four insularine-N-oxides. Two of them are identical in every respect with our insularine-2β-N-oxide (Ⅱ) and insularine-2'β-N-oxide (Ⅲ), two rare examples of naturally occurring head-to-tail bisbenzyliso-quinoline N-oxides newly isolated from Cyclea sutchnenensis, which confirmed the structures of the two novel natural N-oxides. The other two are new. compounds and their structures have been established as insularine-2'α-N-oxide (Ⅳ) and insularine-2β-2'β-N, N-dioxide (Ⅴ), on the basis of spectral data (UV, IR. ¹HNMR, NOEDS AND MS) analysis.     

四川轮环藤根中两种新双苄基异喹啉生物碱的分离鉴定

从中国特有植物四川轮环藤(Cyclea sutchuenensis Gagnep.)根中除分得已知的轮环藤碱(Ⅰ)和异粒枝碱(Ⅱ)外,还分离得到两种新双苄基异喹啉生物碱,分别命名为异轮环藤碱(Ⅲ)和四川轮环藤辛碱(Ⅳ)。经物理常数和波谱数据分析鉴定,证明Ⅲ为轮环藤碱的差向异构体,Ⅳ系一种新型的8-12′,12-7′首尾双氧桥双苄基异喹啉生物碱。