Corticosteroids as adjunctive therapy for diffuse alveolar hemorrhage associated with bone marrow transplantation. University of Nebraska Medical Center Bone Marrow Transplant Group

BACKGROUND: Diffuse alveolar hemorrhage is a frequent complication of treating malignancies with high-dose chemotherapy and bone marrow transplantation and is associated with very high mortality. This disorder's association with pulmonary inflammation, its coincidence with marrow recovery, and the usefulness of corticosteroids for treating other pulmonary hemorrhage syndromes provided the rationale for this study. METHODS: We retrospectively studied 65 episodes of diffuse alveolar hemorrhage that has occurred in 63 of 603 consecutively treated patients who had undergone high-dose chemotherapy with bone marrow transplantation. Patients were divided into three groups according to the therapy they had received for diffuse alveolar hemorrhage: supportive therapy alone (n = 12); low-dose corticosteroids (30 mg or less of methylprednisolone or its equivalent; n = 10); and high-dose corticosteroids (more than 30 mg methylprednisolone or its equivalent; n = 43). The primary outcome measures were overall survival and survival to hospital discharge, occurrence of respiratory failure requiring intubation, and development of infections subsequent to the diagnosis of diffuse alveolar hemorrhage. RESULTS: Overall survival at the end of the follow-up period was significantly higher for the high-dose corticosteroid group compared with the supportive therapy group (P = 0.005); however, treatment with low-dose steroids did not increase survival over supportive therapy alone (P = 0.198). In addition, survival to discharge was significantly increased for the high-dose group compared with the other two groups combined (33% versus 9.1%, P = 0.038). Respiratory failure after the diagnosis of diffuse alveolar hemorrhage developed in only 12 of the 22 unintubated patients in the high-dose group compared with 9 of the 10 initially unintubated patients in the other two groups (P = 0.056). Although the incidence of infections was high (40%) subsequent to diffuse alveolar hemorrhage, neither high-dose nor low-dose corticosteroid treatment significantly increased the risk of infections (P > 0.4, all comparisons). CONCLUSIONS: In this study, high-dose corticosteroid therapy for diffuse alveolar hemorrhage related to bone marrow transplantation was associated with improved total survival and survival to hospital discharge, and decreased development of respiratory failure in these patients. These results suggest the therapy is beneficial, and further prospective studies are warranted to verify the effectiveness of the treatment.     

BAX is required for neuronal death after trophic factor deprivation and during development

Members of the BCL2-related family of proteins either promote or repress programmed cell death. BAX, a death-promoting member, heterodimerizes with multiple death-repressing molecules, suggesting that it could prove critical to cell death. We tested whether Bax is required for neuronal death by trophic factor deprivation and during development. Neonatal sympathetic neurons and facial motor neurons from Bax-deficient mice survived nerve growth factor deprivation and disconnection from their targets by axotomy, respectively. These salvaged neurons displayed remarkable soma atrophy and reduced elaboration of neurities; yet they responded to readdition of trophic factor with soma hypertrophy and enhanced neurite outgrowth. Bax-deficient superior cervical ganglia and facial nuclei possessed increased numbers of neurons. Our observations demonstrate that trophic factor deprivation-induced death of sympathetic and motor neurons depends on Bax.     

Sarcomatoid renal carcinoma with angiosarcomatoid component. Light microscopic and immunohistochemical study

We describe a case of primary renal pelvic carcinoma which showed an unusual histologic pattern of anastomosing blood-filled channels lined by atypical cells. This angiosarcomatoid pattern merged with solid areas typical of renal carcinoma. Immunoperoxidase stains for cytokeratin and epithelial membrane antigen were positive in both the angiosarcomatoid and typical carcinomatous areas, while stains for factor VIII-related antigen and desmin were negative. Since primary renal angiosarcomas are rare neoplasms, the diagnosis of sarcomatoid renal carcinoma should be considered in primary renal neoplasms which show this angiosarcomatoid pattern.     

A model for detecting early metabolic changes in neonatal asphyxia by 1H-MRS

In newborn rabbits, the early cerebral metabolic changes caused by hypoxic-ischemic (H-I) insult was examined by using volume localized 1H-MRS (STEAM). Partial ischemia was caused by unilateral carotid artery ligation, and hypoxia was induced by 10% oxygen inspiration for 150 minutes. Lactate immediately increased after hypoxia induction and almost disappeared 120 to 150 minutes after removal of hypoxia in both H-I and hypoxia-only experiments. Lactate production correlated well with decrease of the blood oxygen saturation. More lactate was produced on ischemic side 50 minutes post-hypoxia induction in H-I study. Ischemia alone did not cause any significant lactate production. Lactate caused by hypoxia can be dynamically monitored by localized 1H-MRS. Existence of regional ischemia can induce greater anaerobic glycolysis and may affect the pattern of brain injury under hypoxia. 1H-MRS is a sensitive tool to detect the acute metabolic change caused by H-I insult.     

Dorsal root ganglion neurons require functional neurotrophin receptors for survival during development

Neurotrophins are the most profound known regulators of survival in the developing peripheral nervous system. Within dorsal root ganglia, the signalling receptors for the different members of the neurotrophin family are distributed in distinct patterns suggesting regulation of different functional classes of sensory neurons. Abnormalities observed in neurotrophin receptor mutant mice have confirmed this idea. Both trkA (-/-) and trkC (-/-) mice have striking neurological defecits referrable to subpopulations of DRG neurons which have distinct axon projections in the periphery. These results thus generalize concepts of dependence on target-derived factors based on extensive work with the prototypical neurotrophin, nerve growth factor. Further analysis of these animals also provides evidence for more complex developmental mechanisms including dependence on locally synthesized neurotrophins at early developmental stages and plasticity of neurotrophin receptor expression.     

Prostate-specific membrane antigen: a novel folate hydrolase in human prostatic carcinoma cells

A novel monoclonal antibody has been developed that reacts strongly with human prostatic cancer, especially tumors of high grade. This antibody (7E11C-5) is currently in Phase 3 trials as an imaging agent for metastatic disease. We have cloned the gene that encodes the antigen that is recognized by the 7E11C-5 monoclonal antibody and have designated this unique protein prostate-specific membrane (PSM) antigen. PSM antigen is a putative class II transmembranous glycoprotein exhibiting a molecular size of Mr 94,000. Functionally, class II membrane proteins serve as transport or binding proteins or have hydrolytic activity. Preliminary studies have demonstrated binding of pteroylmonoglutamate (folate) to membrane fractions that also cross-reacted with the PSM monoclonal antibody. We observed substantial carboxypeptidase activity as folate hydrolase associated with PSM antigen. The purpose of our study was to demonstrate that human prostatic carcinoma cells expressing PSM antigen exhibit folate hydrolase activity using methotrexate triglutamate (MTXGlu3) and pteroylpentaglutamate (PteGlu5) as substrates. Isolated membrane fractions from four human prostate cancer cell lines (LNCaP, PC-3, TSU-Prl, and Duke-145) were examined for folate hydrolase activity using capillary electrophoresis. After timed incubations at various pH ranges and in the presence and absence of thiol reagents, separation of pteroyl(glutamate)n derivatives was achieved with an electrolyte of sodium borate and SDS, while absorbance was monitored at 300 nm. The results demonstrate clearly that LNCaP cells, which highly express PSM, hydrolyze gamma-glutamyl linkages of MTXGlu3. The membrane-bound enzyme is an exopeptidase, because it progressively liberates glutamates from MTXGlu3 and PteGlu5 with accumulation of MTX and PteGlu1, respectively. The semipurified enzyme has a broad activity from pH 2.5 to 9.5 and exhibits activity maxima at pH 5 and 8. Enzymatic activity is maintained in the presence of reduced glutathione, homocysteine, and p-hydroxymercuribenzoate (0.05-0.5 mm) but was inhibited weakly by DTT (>/=0.2 mm). By contrast to LNCaP cell membranes, membranes isolated from other human prostate adenocarcinoma cells (PC-3, Duke-145, and TSU-Pr1) did not exhibit comparable hydrolase activity, nor did they react with 7E11-C5 monoclonal antibody. After transfection of PC-3 cells with a full-length 2.65-kb PSM cDNA subcloned into a pREP7 eukaryotic expression vector, non-PSM antigen-expressing PC-3 cells developed immunoreactivity to 7E11-C5 monoclonal antibody and demonstrated folate hydrolase activities and optimum pH activity profiles identical to those of LNCaP cells. The membrane-bound enzymes from both LNCaP- and PC-3-transfected cells also have a capacity to hydrolyze an alpha-linked glutamyl moiety from N-acetyl-alpha-aspartylglutamate. We have identified that PSM antigen is a pteroyl poly-gamma-glutamyl carboxypeptidase (folate hydrolase) and is expressed strongly in human prostate cancer. Cancer cells that express this enzyme are resistant to methotrexate therapy. Those developing future therapeutic strategies in the treatment of prostate cancer that utilize folate antagonists need to consider this mechanism of resistance.