Bone marrow transplantation for severe aplastic anemia: has outcome improved?

Bone marrow transplants for severe aplastic anemia were first performed in the 1970s. Transplant regimens, supportive care, and patient selection have changed substantially since then. Our objective was to determine the impact of these changes on transplant outcome. We studied 1,305 recipients of HLA-identical sibling transplants for aplastic anemia between 1976 and 1992, reported to the IBMTR by 179 centers. We compared survival of transplants performed in three intervals (1976 through 1980 [n = 186], 1981 through 1987 [n = 648], and 1988 through 1992 [n = 471]) using Cox proportional hazards regression. Five-year survival (+/-95% confidence interval) increased from 48% +/- 7% in the 1976-1980 cohort to 66% +/- 6% in the 1988-1992 cohort (P < .0001). Risks of graft-versus-host disease (GVHD) and interstitial pneumonia decreased over time, but the risk of graft failure did not. Higher long-term survival resulted primarily from decreased mortality in the first 3 months posttransplantation. Late mortality risks were low and changed little over the intervals studied. In multivariate analysis, changes in transplantation strategies accounted for most but not all of the improved outcome. Use of cyclosporine to prevent GVHD was the most important factor. Changes in patient selection did not seem to explain improved survival. Survival after HLA-identical sibling bone marrow transplantations for aplastic anemia has improved since 1976. Changes in GVHD prophylaxis account for much of this improvement. Other changes may also operate.     

Spontaneous healing of a massive tibial cortical defect

BACKGROUND: Intraocular cilia present clinical perplexity due to their radiolucency, the extremely variable ocular response to such cilia, and the inadvisability of using MRI in cases of suspected metallic intraocular foreign bodies (IOFB). METHODS: Two cases of intravitreal cilia associated with phakic penetrating eye injury are described where preoperative CT scan revealed no retained IOFB. RESULTS: B-scan ultrasonography detected intravitreal cilia in one patient and raised this suspicion in the other. One patient presented with endophthalmitis unresponsive to intravitreal antibiotics, the other with culture-negative anterior uveitis. Both underwent vitrectomy and removal of cilia. CONCLUSIONS: Intravitreal cilia should be considered in penetrating eye injuries even in phakic eyes with no radiological evidence of IOFB, especially if associated with endophthalmitis. B-scan ultrasonography may aid detection of intravitreal cilia and thus alter clinical management.     

Regulation of monocyte IL-10 synthesis by endogenous IL-1 and TNF-alpha: role of the p38 and p42/44 mitogen-activated protein kinases

IL-10 is an anti-inflammatory cytokine with potent immunomodulatory effects, including inhibition of cytokine production. However, regulation of monocyte IL-10 production is poorly understood. In this report we have investigated the mechanisms of LPS-induced IL-10 production by human peripheral blood monocytes and demonstrate that IL-10 synthesis is uniquely dependent on the endogenous proinflammatory cytokines IL-1 and/or TNF-alpha. LPS signal transduction in monocytes has been shown to involve activation of the p38 and p42 mitogen-activated protein kinase (MAPK) cascades. The results in this paper indicate that inhibition of p38 MAPK potently inhibited the production of IL-10, IL-1beta, and TNF-alpha, whereas blockade of the p42/44 MAPK pathway, while partially inhibiting TNF-alpha and IL-1beta production, had no effect on monocyte secretion of IL-10. Furthermore, neither the inhibition of monocyte TNF-alpha induced by IL-10 nor the stimulation of soluble TNF receptor production was affected by inhibition of the p42/44 MAPK pathway, suggesting that this signaling event is not involved in either monocyte production of or anti-inflammatory responses to IL-10. These data raise the interesting possibility that proinflammatory TNF-alpha-mediated effects may be selectively blocked without modulating the induction or the response to IL-10, whereas the signaling events associated with the anti-inflammatory events induced by IL-10 remain to be elucidated.     

Ribonuclease A variants with potent cytotoxic activity

Select members of the bovine pancreatic ribonuclease A (RNase A) superfamily are potent cytotoxins. These cytotoxic ribonucleases enter the cytosol, where they degrade cellular RNA and cause cell death. Ribonuclease inhibitor (RI), a cytosolic protein, binds to members of the RNase A superfamily with inhibition constants that span 10 orders of magnitude. Here, we show that the affinity of a ribonuclease for RI plays an integral role in defining the potency of a cytotoxic ribonuclease. RNase A is not cytotoxic and binds RI with high affinity. Onconase, a cytotoxic RNase A homolog, binds RI with low affinity. To disrupt the RI-RNase A interaction, three RNase A residues (Asp-38, Gly-88, and Ala-109) that form multiple contacts with RI were replaced with arginine. Replacing Asp-38 and Ala-109 with an arginine residue has no effect on the RI-RNase interaction. In addition, these variants are not cytotoxic. In contrast, replacing Gly-88 with an arginine residue yields a ribonuclease (G88R RNase A) that retains catalytic activity in the presence of RI and is cytotoxic to a transformed cell line. Replacing Gly-88 with aspartate also yields a ribonuclease (G88D RNase A) with a decreased affinity for RI and cytotoxic activity. The cytotoxic potency of onconase, G88R RNase A, and G88D RNase A correlate with RI evasion. We conclude that ribonucleases that retain catalytic activity in the presence of RI are cytotoxins. This finding portends the development of a class of chemotherapeutic agents based on pancreatic ribonucleases.     

Glucose content in human skin: relationship with blood glucose levels

In order to ascertain the dynamic relationship between the extracellular glucose in upper skin layers and blood glucose, skin suction blisters were raised in six Type 1 diabetic patients during a three-step glucose clamp. Blister glucose closely paralleled venous glucose (mean of r = 0.998). However, in three patients blister glucose was constantly lower than plasma glucose and this appeared to be related to their slower formation of skin blisters. A substantial difference in skin blister suction time was noted among patients and it was found that suction time was linearly correlated to glycosylated haemoglobin (HbA1C) (n = 6, r = 0.865, p = 0.026). It is concluded that a non-invasive blood glucose monitoring system could be successfully based on measurement of alterations in skin glucose contents.     

Lymphoma cell burden in progenitor cell grafts measured by competitive polymerase chain reaction: less than one log difference between bone marrow and peripheral blood sources

The suppressor of Hairy-wing [SU(HW)] binding region disrupts communication between a large number of enhancers and promoters and protects transgenes from chromosomal position effects. These properties classify the SU(HW) binding region as an insulator. While enhancers are blocked in a general manner, protection from repressors appears to be more variable. In these studies, we address whether repression resulting from the Polycomb group genes can be blocked by the SU(HW) binding region. The effects of this binding region on repression established by an Ultrabithorax Polycomb group Response Element were examined. A transposon carrying two reporter genes, the yellow and white genes, was used so that repression and insulation could be assayed simultaneously. We demonstrate that the SU(HW) binding region is effective at preventing Polycomb group repression. These studies suggest that one role of the su(Hw) protein may be to restrict the range of action of repressors, such as the Polycomb group proteins, throughout the euchromatic regions of the genome.     

Variation in incidence of indinavir-associated nephrolithiasis among HIV-positive patients

BACKGROUND: Nephrolithiasis may be an important consequence of indinavir therapy; however little has been published on the variation in incidence between different populations of patients or the possible mechanisms of calculus formation. OBJECTIVE: To examine variation in the incidence of indinavir-associated nephrolithiasis (IAN) in HIV-positive patients in relation to hemophilia and hepatitis C virus (HCV) infection. METHODS: Clinical data were abstracted retrospectively from the medical records of all adult patients treated with indinavir from September 1995 to September 1997. Occurrence of first IAN, defined as flank pain and hematuria after initiation of therapy, was analyzed in relation to hemophilia status and HCV infection. RESULTS: There were 17 episodes of IAN (22%) among 79 patients treated with indinavir. Of 10 patients with hemophilia, 50% developed IAN as compared with 17% of patients without hemophilia (P = 0.03). Median days to first IAN was 22 (range 7-110 days) for hemophiliacs and 156 (range 5-611 days) for those without hemophilia. Data for HCV status were available for 74 out of 79 patients: 10 out of 27 (37%) patients with HCV developed IAN compared with six out of 42 (14%) without HCV (P = 0.02). CONCLUSION: Overall incidence of IAN was higher than that previously reported and was significantly greater in hemophiliacs than in non-hemophiliacs. HCV may be a contributing factor.     

Single-center randomized trial comparing tacrolimus (FK506) and cyclosporine in the prevention of acute myocardial rejection

BACKGROUND: To compare the efficacy and safety of tacrolimus and cyclosporine in heart transplantation, this single-center, prospective, randomized, open-label clinical trial was undertaken. METHODS: Seventy-three adult patients were randomly assigned at the time of transplantation to receive either tacrolimus (n=43) or cyclosporine (n=30) as the primary immunosuppressant. Ten of the 43 patients in the tacrolimus group received the drug intravenously in the perioperative period; all other patients received only oral tacrolimus. RESULTS: With a mean follow-up of 27 months, patient survival rates (tacrolimus 83%, cyclosporine 81%) were similar. Fewer patients experienced acute rejection in the tacrolimus group (79%) than in the cyclosporine group (100%), but the difference was not statistically significant. The number of infections and dialysis and insulin requirements were similar for the 2 treatment groups, but the proportion of patients requiring multidrug antihypertensive regimens was lower in the tacrolimus group (12.5% vs 50.0% at month 6; p=.025). The interpatient variance in pharmacokinetic parameters in a subset of 10 patients was much higher after the first oral dose of tacrolimus than at steady-state (eg, first-dose time at which maximal concentration is reached (t(max)): 3.5+/-2.5h, steady-state t(max): 2.0+/-0.7h), and patients treated with intravenous tacrolimus (n=13) rather than oral tacrolimus (n=30) reached target concentrations faster and with less interpatient variability (eg, at day 0: 9.72+/-10.9 ng/mL intravenously vs 3.31+/-8.1 orally). CONCLUSIONS: Tacrolimus was associated with similar efficacy and safety profiles compared with cyclosporine. The higher interpatient variance in absorption associated with oral tacrolimus during the first few days after transplantation would suggest that intravenous tacrolimus should be used during the perioperative period.