Rescue of signaling by a chimeric protein containing the cytoplasmic domain of CD45.

Surface expression of the CD45 tyrosine phosphatase is essential for the T cell antigen receptor (TCR) to couple optimally with its second messenger pathways. CD45 may be required to dephosphorylate a TCR-activated protein tyrosine kinase, which then transduces an activation signal from the TCR. A chimeric molecule that contained extracellular and transmembrane sequences from an allele of a major histocompatibility class I molecule and cytoplasmic sequences of CD45 restored TCR signaling in a CD45-deficient mutant T cell line. Thus, expression of the complex extracellular domain of CD45 is not required for the TCR to couple to its signaling machinery.

Change in erythropoietin pharmacokinetics following hematopoietic transplantation.

Pre-clinical studies have demonstrated that bone marrow ablation has a profound effect in decreasing erythropoietin (EPO) elimination. The study's objective was to determine in humans if EPO pharmacokinetics (PKs) are perturbed following bone marrow ablation. EPO PK studies were performed in eight subjects, aged 4 to 61 years, undergoing fully myeloablative hematopoietic stem cell transplantation. Serial PK studies using intravenous injection of recombinant human EPO (92+/-2.0 U/kg) (mean+/-SEM) were carried out during four periods of altered marrow integrity: baseline pre-ablation, post-ablation pre-transplant, early post-transplant pre-engraftment, and late post-transplant full engraftment. Compared with baseline, post-ablation pre-transplant and early post-transplant EPO PKs demonstrated declines in clearance increases in terminal elimination half-life of 36 and 95%, respectively. Clearance and half-life returned to baseline following full engraftment. The association of EPO elimination with decreased bone marrow activity in patients undergoing transplantation conclusively establishes the bone marrow as a key determinant of EPO elimination in humans.

Defective expression of p56lck in an infant with severe combined immunodeficiency.

Severe combined immune deficiency (SCID) is a heterogeneous disorder characterized by profound defects in cellular and humoral immunity. We report here an infant with clinical and laboratory features of SCID and selective CD4 lymphopenia and lack of CD28 expression on CD8(+) T cells. T cells from this patient showed poor blastogenic responses to various mitogens and IL-2. Other T cell antigen receptor- induced responses, including upregulation of CD69, were similarly inhibited. However, more proximal T cell antigen receptor signaling events, such as anti-CD3 induced protein tyrosine phosphorylation, phosphorylation of mitogen-associated protein kinase, and calcium mobilization were intact. Although p59fyn and ZAP-70 protein tyrosine kinases were expressed at normal levels, a marked decrease in the level of p56lck was noted. Furthermore, this decrease was associated with the presence of an alternatively spliced lck transcript lacking the exon 7 kinase encoding domain. These data suggest that a deficiency in p56lck expression can produce a SCID phenotype in humans.

Successful unrelated umbilical cord blood transplantation in children with Shwachman-Diamond syndrome.

Shwachman-Diamond syndrome (SDS) is an autosomal recessive disorder characterized by pancreatic insufficiency and variable degrees of neutropenia. SDS patients are at risk of developing myelodysplasia, aplastic anemia, and leukemic transformation. The role and timing of allogeneic hematopoietic stem cell transplantation (HSCT) in SDS remain controversial. We report three SDS patients with severe aplasia transplanted using unrelated umbilical cord blood (UCB). Patients received melphalan (180 mg/m2), etoposide (1200 mg/m2), anti-thymocyte globulin (90 mg/kg), and total lymphoid irradiation (500 cGy); graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and prednisone. Myeloid engraftment occurred promptly with absolute neutrophil count >500 cells/mm3 on day 15 +/- 5 and all patients displayed 100% donor chimerism by 2 months post transplant. The major complication of transplant was GVHD, with all patients developing grade II or III acute GVHD, one progressing to chronic extensive GVHD. Patients are alive 309, 623, and 2029 days post transplant. Factors important in HSCT outcome for SDS may include transplantation at a young age, avoidance of cyclophosphamide, and adequate GVHD prophylaxis. Importantly, these cases also suggest that unrelated UCB, in the absence of a matched family member, is an excellent alternative stem cell source for SDS patients undergoing HSCT.

Treatment of therapy-refractory B-lineage acute lymphoblastic leukemia with an apoptosis-inducing CD19-directed tyrosine kinase inhibitor.

Seven children and eight adults with CD19+ B-lineage acute lymphoblastic leukemia, as well as one adult with chronic lymphocytic leukemia, were treated with the CD19 receptor-directed tyrosine kinase inhibitor B43-Genistein. All patients had failed previous chemotherapy regimens, and six patients had relapsed after bone marrow transplantation. B43-Genistein was administered as a 1-hour i.v. infusion at 0.1-0.32 mg/kg/day dose levels for 10 consecutive days or 3 consecutive days weekly for a total of nine doses. B43-Genistein was well tolerated by all patients with no life-threatening side effects. There were six episodes of grade 2-3 fever, two of which were clearly drug related, one episode each of grade 3 myalgia, grade 2 sinus tachycardia, and grade 2 vascular leak syndrome. There was one durable complete remission and two transient responses. Pharmacokinetic analyses in 12 patients revealed a plasma half-life of 20 +/- 5 h, mean residence time of 24 +/- 5 h, and a systemic clearance rate of 20 +/- 3 ml/h/kg. Moderate levels of human antimouse antibody (HAMA) ranging from 20-87 ng/ml were detected in the day 28 blood samples from three of nine cases examined. Treatment of these three HAMA-positive patients with a second course of B43-Genistein did not yield measurable immunoconjugate levels in the plasma, indicating that the administered B43-Genistein molecules were rapidly cleared from circulation due to the HAMA. On the basis of its acceptable toxicity profile and its ability to elicit objective responses at nontoxic dose levels, B43-Genistein may provide the basis for an effective treatment strategy for B-lineage acute lymphoblastic leukemia patients who have failed standard therapy.

Restoration of CD2-mediated signaling by a chimeric membrane protein including the cytoplasmic sequence of CD45.

We showed previously that the TCR and CD2 fail to couple efficiently with their signal transduction machinery in J45.01, a CD45-deficient variant of the Jurkat T-cell line. Transfection into J45.01 of a cDNA encoding a chimeric membrane protein containing the cytoplasmic sequence of CD45 and extracellular and transmembrane sequences derived from the A2 allele of MHC class I rescues proximal signaling events after TCR stimulation. In this report, we describe rescue of CD2-mediated signaling and evaluate further the characteristics of TCR signaling in J45.01 after expression of the chimeric protein. Cells expressing the chimeric molecule demonstrate TCR- and CD2-mediated increases in PTK activity and PI turnover. Stimulation of the TCR and CD2 on the transfected cells also results in the expression of CD69 on the cell surface, a more distal signaling event. Although these measures of signal transduction via the TCR and CD2 are restored in the transfected cells, the magnitude of the responses are less than those seen in the wild-type Jurkat cells. These findings demonstrate that the cytoplasmic domain of CD45, expressed as a chimeric membrane protein, is sufficient for mediating signal transduction through CD2 as well as through the TCR complex. In addition, these results suggest that the extracellular and/or transmembrane domains of CD45 may contribute to the efficiency of signal transduction.

Effect of in vivo lymphocyte-depleting strategies on development of lymphoproliferative disorders in children post allogeneic bone marrow transplantation.

T cell depletion (TCD) of marrow is a proven method of graft-versus-host disease (GVHD) prophylaxis in allogeneic bone marrow transplantation (BMT). Nonetheless, TCD is associated with an increased risk of developing post transplant lymphoproliferative disorder (PTLD). Between 1986 and 1998, 241 pediatric patients at the University of Iowa underwent BMT using ex vivo TCD of marrow from mismatched related or matched unrelated donors. Additional GVHD prophylaxis included antithymocyte globulin (ATG) or anti lymphocyte globulin (ALG) post transplant (in vivo TCD). A total of 30 cases of PTLD were identified based upon a combination of clinical, histological, and immunological features. Nearly all cases occurred within 3 months post BMT. A statistically significant increase in PTLD incidence was noted for patients treated with ATG vs ALG (33 vs 9%). While grade I-II acute GVHD was more common in patients receiving ATG vs ALG, no difference in grade III-IV GVHD or overall survival was noted between the two groups. Assessment of immune recovery at various times post BMT revealed significantly fewer T cells in the ATG-treated group, suggesting the deleterious effect of ATG may be due to excessive depletion of donor-derived Epstein-Barr virus-specific cytotoxic T cells. Thus, caution should be exercised in the use of anti-T-cell antibody therapy for additional GVHD prophylaxis in the setting of TCD BMT.

Poor outcome in children with refractory/relapsed leukemia undergoing bone marrow transplantation with mismatched family member donors.

The utility of bone marrow transplantation for childhood leukemia in patients unable to achieve a remission prior to transplant is controversial. To address this issue, we analyzed a subset of patients with advanced leukemia entered on prospective transplant trials at our hospital. Fifty-eight patients with ALL or AML (age 1-19) were identified. They had failed standard chemotherapy and were in relapse (22 in 1st, 27 in 2nd, three in 3rd, and three in 4th) or had never achieved an initial remission (three) at the time of transplant. Fifty-two patients received marrow from mismatched family members (haplo or DR-identical), while six received marrow from matched siblings. Most patients received myeloablative therapy consisting of total body irradiation, etoposide, cyclophosphamide, and cytosine arabinoside. Marrow from mismatched donors was T cell depleted. Only one of 52 patients transplanted with a mismatched donor survived long-term while three of six patients transplanted in relapse with a fully matched sibling donor are alive 6-10 years post BMT. The major causes of death were infection (39%) and relapse (28%). Acute GVHD grade III-IV was noted in 7% of patients. A comparable group of patients with leukemia transplanted at our center in remission using similarly mismatched family member donors (haplo or DR-identical) had an event-free survival of 28%. In conclusion, our data suggest that BMT utilizing mismatched family member donors is a poor option for patients in relapse at the time of transplant. New treatment strategies need to be developed to effectively manage these patients.

Complete heart block in association with graft-versus-host disease.

An infant who received haploidentical BM for severe combined immunodeficiency (SCID) developed acute, reversible complete heart block in association with an exacerbation of GVHD. Respiratory distress and myocardial dysfunction were also seen with this and previous GVHD exacerbations. The patient had not received chemotherapy or radiation prior to BMT. The complete heart block resolved after 1 week of intensive immunosuppression. The association of complete heart block with GVHD is important because the heart block is potentially reversible with prompt, aggressive control of the GVHD.

Successful allogeneic hematopoietic stem cell transplantation (HSCT) for Shwachman-Diamond syndrome.

Shwachman-Diamond syndrome (SDS) is a rare genetic disorder characterized by pancreatic insufficiency, short stature, skeletal abnormalities and bone marrow dysfunction. Patients with SDS have varying degrees of marrow aplasia, which can be severe or progress to leukemic transformation. While allogeneic hematopoietic stem cell transplantation (HSCT) can be curative for the hematologic disturbances of SDS, a recent review of the literature reveals few survivors. Poor outcome with HSCT is often related to excessive cardiac and other organ toxicity from transplant preparative therapy. We describe two young children with SDS who developed aplastic anemia and subsequently underwent successful allografting using a non-cardiotoxic conditioning regimen. Case 1 received marrow from an HLA-identical sibling while case 2 received partially matched umbilical cord blood from an unrelated donor. Both patients are presently alive and well with sustained donor engraftment and excellent hematopoietic function at 36 and 22 months post-HSCT.

Abnormal diurnal weight gain among long-term patients with schizophrenic disorders.

We found diurnal weight gain to be abnormal among 65 long-term patients with schizophrenic disorders. Patients were weighed at 7 a.m. and 4 p.m. serially and diurnal weight gain was normalized (NDWG) as a percentage by subtracting the 7 a.m. weight from the 4 p.m. weight, multiplying the difference by 100, and then dividing the result by the 7 a.m. weight. NDWG was 2.2 +/- 1.5% for 47 male patients compared (P = 0.001) with 0.6 +/- 0.4% for 11 male controls. NDWG was 1.7 +/- 0.7% for 18 female patients compared (P less than 0.0001) with 0.5 +/- 0.3% for 14 female controls. We hypothesize that NDWG may be an index of both the severity and duration of the schizophrenic disorder.

Clinical pharmacokinetics of the CD19 receptor-directed tyrosine kinase inhibitor B43-Genistein in patients with B-lineage lymphoid malignancies.

The authors examined the pharmacokinetics of the CD19 receptor-directed tyrosine kinase inhibitor B43-Genistein in 17 patients (4 children, 13 adults) with B-lineage lymphoid malignancies, including 12 patients with acute lymphoblastic leukemia (ALL) and 5 patients with non-Hodgkin's lymphoma (NHL). The immunoconjugate was administered intravenously as a 1-hour continuous infusion at a dose level of either 0.1 mg/kg (N = 12) or 0.18 mg/kg (N = 5), and the plasma concentration-time data were modeled by using the WinNonlin program to estimate the pharmacokinetic parameters. Pharmacokinetic analyses revealed a plasma half-life of 19 +/- 4 hours, mean residence time of 22 +/- 4 hours, and a systemic clearance of 18 +/- 2 mL/h/kg. The average (mean +/- SEM) values for the maximum plasma concentration Cmax, volume of distribution at steady state (Vss), and area under curve (AUC) were 1092 +/- 225 ng/ml, 291 +/- 37 mL/kg, and 9987 +/- 2021 micrograms x h/L, respectively. The AUC values were higher at the 0.18 mg/kg dose level than at the 0.1 mg/kg dose level (16,848 +/- 5118 micrograms x h/L vs. 7128 +/- 1156 micrograms x h/L, p = 0.009). Patients with ALL had a significantly larger volume of distribution at steady state (332 +/- 47 mL/kg vs. 191 +/- 12 mL/kg, p = 0.04), faster clearance (21 +/- 3 mL/h/kg vs. 11 +/- 2 mL/h/kg, p = 0.03), and lower dose-corrected AUC than patients with NHL (6010 +/- 836 micrograms x h/L vs. 12,044 +/- 2707 micrograms x h/L, p = 0.006). There was a trend toward faster clearance rates (23 +/- 4 mL/h/kg vs. 16 +/- 3 mL/h/kg, p = 0.1), shorter elimination half-lives (5.7 +/- 3.6 hours vs. 13 +/- 8.8 hours, p = 0.1), and shorter mean residence times (11 +/- 3 hours vs. 25 +/- 5 hours, p = 0.08) for non-Caucasian patients as compared to Caucasian patients. When compared to adult patients, pediatric patients showed a significantly larger volume of distribution at steady state (418 +/- 82 mL/kg vs. 252 +/- 34 mL/kg, p = 0.02) and a longer elimination half-lives (18.4 +/- 13.6 hours vs. 8.7 +/- 6.7 hours, p = 0.04). The pharmacokinetics of B43-Genistein was not affected by the gender of the patients or by bone marrow transplantation in past medical history. Overall, B43-Genistein showed favorable pharmacokinetics in this heavily pretreated leukemia/lymphoma patient population, which is reminiscent of its recently reported favorable pharmacokinetics in cynomolgus monkeys. To our knowledge, this is the first clinical pharmacokinetics study of a tyrosine kinase inhibitor containing immunoconjugate.

Diurnal weight gain in chronic psychosis.

We found diurnal weight gain to be abnormal among 93 chronically psychotic patients, most of whom had schizophrenia. They were weighed at 7 a.m. and 4 p.m. weekly for 3 weeks. We normalized the diurnal weight gain (NDWG) as a percentage by subtracting the 7 a.m. weight from the 4 p.m. weight, multiplying the difference by 100, and dividing the result by the 7 a.m. weight. NDWG was 1.7 +/- 1.0 percent for the study sample, 0.6 +/- 0.4 percent for 16 acutely psychotic controls, and 0.5 +/- 0.4 percent for 29 normals. More than 60 percent of the study sample had abnormal NDWG values. NDWG related to antipsychotic drug dose (r = 0.290, p = 0.005) with variability in drug dose accounting for 8 percent of the variability in NDWG. This report provides yet another piece of evidence that disordered water balance is common in chronic psychiatric patients. The etiology is unknown, but it may relate to subtle brain abnormalities in the regulation of fluid intake and excretion.

Determinants of interest rates on tax-exempt hospital bonds.

The aim of this paper is to examine the determinants of interest rates on tax-exempt hospital bonds. The results highlight the potential and actual roles of Federal and state policy in the determination of these rates. The shift to a Prospective Payment System under Medicare has subsidized the borrowing costs of some hospitals at the expense of others. The selection of underwriters by negotiation rather than by competitive bidding results in higher interest rates. The Federal tax act of 1986 raised the cost of hospital debt by encouraging bond issues to contain call features.

Maxillary removal and reinsertion for anterior cranial base tumors: long-term results.

OBJECTIVE: To evaluate complications and sequelae of maxillary removal and reinsertion for anterior cranial base tumors. DESIGN: A retrospective review of patients who underwent maxillary removal and reinsertion from 1990 to 1996. SETTING: The Arthur G. James Cancer Hospital and Research Institute at The Ohio State University, Columbus. PATIENTS: A consecutive sample of 46 patients who underwent maxillary removal and reinsertion. The patients ranged in age from 11 to 77 years and were followed up for as long as 6 years after surgery. There were 16 benign and 30 malignant lesions. MAIN OUTCOME MEASURES: Intraoperative, postoperative (1-10 days), short-term (11 days through 3 months), and long-term (>3 months) complications; survival status of patients; and adjuvant therapy. RESULTS: Four patients (9%) had undergone previous radiotherapy; 9 (20%) received intraoperative radiation therapy; and 23 (50%) received planned postoperative radiotherapy. No intraoperative complications were noted. The most common short-term complication found was transient diplopia, affecting 9 patients (20%). Diplopia resolved within 3 months in all but 2 patients, in whom the condition was permanent. There were 4 patients (9%) who required removal of the nasal dorsum plate, and 4 (9%) who required removal of maxillary plates that were exposed intranasally. Midface asymmetry as reported by the patient or noted on the physical examination was documented in only 2 patients. The most common long-term complication was nasal asymmetry, affecting 13 patients (28%). CONCLUSIONS: Maxillary removal allows improved visualization and access to anterior skull base lesions, while reinsertion of the maxillary fragment provides functional preservation and excellent cosmesis with few short- or long-term complications, even when adjuvant radiotherapy is used.

Long-term follow-up of Keller arthroplasty with irradiated costochondral implants.

The authors present results of long-term follow-up of seven patients whose degenerative disease of the first metatarsophalangeal joint was treated with irradiated chondral graft implantation arthroplasty. In appropriate candidates, this procedure is a reasonable alternative to Keller arthroplasty alone, arthrodesis, and nonbiologic implant arthroplasty.

Surgical approach for enlarged peroneal tubercles.

The peroneal tubercle is an anatomic landmark consistently found on the lateral aspect of the calcaneus. Its enlargement can be either congenital or acquired. In the past, surgical treatment of enlarged tubercles has consisted of simple excision of the tubercle. The authors have presented a technique to preserve the gliding facet that is often found on the inferior surface of the tubercle.

Compartment pressure in the foot. Analysis of normal values and measurement technique.

This clinical trial was carried out to verify the validity of the current objective compartment pressure parameters described in the forearm and leg for use in the foot. The authors evaluated the compartment pressures of the central plantar compartment in 25 normal volunteers (94 separate measurements). In addition to determining an average normal foot compartment pressure, two methods of measurement were compared. Results showed no significant difference in normal values through the use of an arterial line monitor technique (5.98 +/- 2.78 mm Hg [SD]) as compared with a Stryker intracompartmental pressure monitor (4.69 +/- 2.62 mm Hg [SD]). It was found that pedal edema caused a statistically significant increase in pressures. The authors propose a standard technique for pedal compartment pressure measurement and discuss diagnosis and management of compartment syndrome in the foot.

Renal cell carcinoma and osseous metastases. Case report and literature review.

Renal cell carcinoma is one of the great mimics in medicine. The diagnosis is complicated by clinical presentations involving a multitude of symptoms, often associated with the sites of metastasis. A high percentage of renal cell carcinomas have metastasized at the time of initial presentation, and symptoms associated with this metastasis may actually initiate the diagnosis. Because the site of tumor origin is frequently unknown, a diagnostic strategy for identifying the primary source has been proposed. The prognosis for renal cell carcinoma with metastasis is poor, with fewer than 9% of patients surviving at 5 years. Consequently, treatment is directed primarily at palliation of painful symptoms and stabilization of bony structures. With these goals in mind, treatment modalities run the gamut from radiotherapy, to curettage with polymethyl methacrylate augmentation, to amputation. In the case reported here, renal cell carcinoma was diagnosed in the course of evaluation of a painful lytic lesion of the foot. Treatment alternatives and associated risks and complications were discussed at some length and the patient chose curettage and packing with polymethyl methacrylate in combination with radiotherapy. This approach was successful in palliation of pain and maintenance of walking ability and independence.