Citations

AbstractMultiple myeloma (MM) is a B-lineage malignancy characterized by diverse genetic subtypes and clinical outcomes. The recurrent immunoglobulin heavy chain (IgH) switch translocation, t(4;14)(p16;q32), is associated with poor outcome, though the mechanism is unclear. Quantitative reverse-transcription–polymerase chain reaction (RT-PCR) for proposed target genes on a panel of myeloma cell lines and purified plasma cells showed that only transcripts originating from the WHSC1/MMSET/NSD2 gene are uniformly dysregulated in all t(4;14)POS patients. The different transcripts detected, multiple myeloma SET domain containing protein (MMSET I), MMSET II, Exon 4a/MMSET III, and response element II binding protein (RE-IIBP), are produced by alternative splicing and alternative transcription initiation events. Translation of the various transcripts, including those from major breakpoint region 4-2 (MB4-2) and MB4-3 breakpoint variants, was confirmed by transient transfection and immunoblotting. Green fluorescent protein (GFP)–tagged MMSET I and II, corresponding to proteins expressed in MB4-1 patients, localized to the nucleus but not nucleoli, whereas the MB4-2 and MB4-3 proteins concentrate in nucleoli. Cloning and localization of the Exon 4a/MMSET III splice variant, which contains the protein segment lost in the MB4-2 variant, identified a novel protein domain that prevents nucleolar localization. Kinetic studies using photobleaching suggest that the breakpoint variants are functionally distinct from wild-type proteins. In contrast, RE-IIBP is universally dysregulated and also potentially functional in all t(4;14)POS patients irrespective of fibroblast growth factor receptor 3 (FGFR3) expression or breakpoint type.

AbstractOur aim was to examine the long‐term success of cholecystoenterostomy performed for the relief of benign extrahepatic biliary obstruction. Concern about the ability of cholecystoenterostomy to provide reliable long‐term biliary decompression has led many to abandon its use for benign biliary obstruction. Thirty‐four patients who underwent cholecystoenterostomy for benign biliary obstruction over a 17‐year period were reviewed. Patients were followed until cholecystoenterostomy failure, death, or to date. Failure was defined as recurrent biliary obstruction or cholangitis requiring therapeutic intervention. Mean follow‐up was 8.0 years. Early postoperative morbidity occurred in 11 patients (32%), but only one early complication (cholangitis) was related directly to the cholecystoenteric anastomosis. Five patients (15%) experienced late biliary tract complications related directly to the cholecystoenterostomy including recurrent biliary stones with biliary obstruction in four and anastomotic stricture in one. All required reoperation and conversion to choledochoenterostomy at a mean of 112 months. Cholecystoenterostomy can provide reasonably effective long‐term biliary decompression in selected patients with benign biliary obstruction.

ABSTRACT The pathophysiology of sepsis involves excessive lymphocyte apoptosis, which correlates with adverse outcomes, and disordered cytokine production, which may promote host injury. As the protease inhibitor (PI) class of antiretroviral agents is known to prevent apoptosis in vitro, we evaluated their effect on survival, lymphocyte apoptosis, and consequent cytokine production in mice with sepsis induced by cecal ligation and perforation. Mice pretreated with PIs have improved survival (67%; P <0.0005) compared with controls (17%) and a significant (P<0.05) reduction in lymphocyte apoptosis. Even mice receiving therapy beginning 4 h after perforation demonstrated improved survival (50%; P <0.05) compared with controls. PI therapy is also associated with an increase in the Th1 cytokine TNF‐a ( P <0.05) early in sepsis and a reduction in the Th2 cytokines IL‐6 and IL‐10 ( P <0.05) late in sepsis; despite no intrinsic antibacterial effects, PI also reduced quantitative bacterial blood cultures. The beneficial effects of PI appear to be specific to lymphocyte apoptosis, as lymphocyte‐deficient Rag1—/— mice did not experience benefit from treatment with PI. Thus, inhibition of lymphocyte apoptosis by PI is a candidate approach for the treatment of sepsis.— Weaver, J. G. R., Rouse, M. S., Steckelberg, J. M., Badley, A. D. Improved survival in experimental sepsis with an orally administered inhibitor of apoptosis. FASEB J. 18, 1185–1191 (2004)

ABSTRACT Pneumocystis species remain an important cause of life-threatening pneumonia in immunocompromised hosts, including those with AIDS. Responses of the organism to environmental cues both within the lung and elsewhere have been poorly defined. Herein, we report the identification of a cell wall biosynthesis kinase gene ( CBK1 ) homologue in Pneumocystis carinii , isolated by differential display PCR, that is expressed optimally at physiological pH (7 to 8) as opposed to more acidic environments. Expression of Pneumocystis CBK1 was also induced by contact with lung epithelial cells and extracellular matrix. Translation of this gene revealed extensive homology to other fungal CBK1 kinases. Pneumocystis CBK1 expression was equal in the cyst and trophic life forms of the organisms. We further demonstrate that Pneumocystis CBK1 expressed in cbk1Δ Saccharomyces cerevisiae cells restored defective cell wall separation during proliferation. Consistent with this, Pneumocystis CBK1 expression also stimulated transcription of the CTS1 chitinase in cbk1Δ mutant yeast cells, an event necessary for cell wall separation. In addition, Pneumocystis CBK1 cDNA supported normal mating projection formation in response to α-factor in the cbk1Δ yeast cells. Site-directed mutations of serine-303 and threonine-494, potential regulatory phosphorylation sites in Pneumocystis CBK1, abolished mating projection formation, indicating a role for these amino acid residues in CBK1 activity. These findings indicate that Pneumocystis CBK1 is an environmentally responsive gene that may function in signaling pathways necessary for cell growth and mating.

Purpose Atypical teratoid/rhabdoid tumor (AT/RT) of the CNS is an extremely rare and aggressive tumor of early childhood. The poor outcome with conventional infant brain tumor therapy has resulted in a lack of clear treatment guidelines. A registry has been established to create an outcomes database and to facilitate biology studies for this tumor. Materials and Methods A standardized data sheet was provided to treating physicians listing the reports that were to be sent to the registry for abstraction. Follow-up information was sought twice yearly. Results Information was complete for 42 patients. Median age at diagnosis was 24 months. Nine patients (21%) had disseminated disease at diagnosis. Sixteen tumors were infratentorial; 26 were supratentorial. Twenty patients (48%) received a primary complete resection. Primary therapy included chemotherapy in all patients, radiotherapy in 13 patients (31%), stem-cell rescue in 13 patients (31%), and intrathecal chemotherapy in 16 patients (38%). Recurrent or progressive disease was reported in nine and 19 patients, respectively. Twenty-seven patients (64%) are dead of disease (3 to 62 months from diagnosis) and one patient died of toxicity. Fourteen patients (33%) show no evidence of disease (9.5 to 96 months from diagnosis). The median survival is 16.75 months and the median event-free survival is 10 months. Conclusion Aggressive therapy has prolonged the natural history in a subset of children. Prospective multi-institutional and national clinical trials designed specifically for AT/RT are needed. Enrollment onto the AT/RT registry should be continued.