Morphologic, immunologic, and cytogenetic classification of acute myeloid leukemia and myelodysplastic syndrome in childhood: a report from the Childrens Cancer Group

The purposes of this report are to reaffirm concordance difficulties with the acute myeloid leukemia (AML) French-American-British (FAB) classification, to present the frequency of previously delineated AML syndromes in pediatric patients and to describe additional characteristic AML profiles utilizing composite morphologic, cytogenetic and immunophenotypic data. Profiles of 124 children with acute myeloid leukemia (AML) and 13 children with myelodysplastic syndrome entered on the Childrens Cancer Group (CCG) pilot study CCG-2861 were examined. Concordance between institutions and reviewers for FAB designation was 65%. Discordance was found principally between M1 and M2, M2 and M4, and M4 and M5. In 49% of marrow specimens, leukemic blasts expressed at least one T lineage-related antigen; 24% expressed the B lineage-related antigen CD19. CDw14 correlated with FAB M4 or M5 morphology and was the only surface antigen associated with a specific FAB subtype. Normal karyotypes were found for 15% of the 75 children with satisfactory karyotype preparations. Recurring aberrations, found in 76% of children, included t(15;17)(q22;q11), t(8;21)(q22;q22), inv(16)(p13q22), rearrangements of band 11q23, t(6;9) (p23;q34), trisomy 8 and monosomy 7. Results from this pilot study and from the current CCG randomized trial correlating morphology, immunophenotyping and cytogenetics, will help to classify AML into unique subgroups with differing clinical consequences or therapy requirements.

Factors that influence collection and engraftment of autologous peripheral-blood stem cells

PURPOSE

To analyze factors that affect the collection of peripheral-blood stem cells (PBSC) before transplant and the tempo of engraftment after transplant.

PATIENTS AND METHODS

A consecutive series of 243 patients with breast cancer (n = 87), malignant lymphoma (n = 90), multiple myeloma (n = 32), or other malignancies (n = 34) had PBSC collected following stimulation with colony-stimulating factors (CSFs) or after chemotherapy followed by CSF. Infusion of PBSC was performed following myeloablative chemotherapy with chemotherapy with or without total-body irradiation (TBI). Postinfusion CSFs were administered to 72 patients. An analysis of factors that influence CD34+ cell yield was performed by linear regression. Cox regression analysis was used to determine factors that affect the kinetics of granulocyte and platelet recovery following infusion of PBSC.

RESULTS

Mobilization with chemotherapy followed by CSF, a diagnosis of breast cancer, absence of marrow disease, no prior history of radiation therapy, and fewer cycles of conventional-dose chemotherapy were associated with a higher average daily yield of CD34+ cells. In the multivariate analysis, the CD34 content of infused cells and the use of a posttransplant CSF influenced neutrophil recovery after infusion of PBSC. CD34 content was also important for predicting platelet recovery. The use of postinfusion CSF was associated with a significant delay in platelet recovery in patients who received less than 5.0 x 10(6) CD34+ cells/kg, but there was no discernable effect in patients who received greater than 5.0 x 10(6) CD34+ cells/kg.

CONCLUSION

Disease status and prior treatment influence the ability to mobilize PBSC. CD34 cell dose is an important predictor of engraftment kinetics after PBSC transplant, regardless of disease or mobilization technique. The use of postinfusion CSF improves neutrophil recovery, but at low CD34 doses can delay platelet recovery.

Recombinant aprotinin in coronary artery bypass graft operations

OBJECTIVE

To evaluate the role of recombinant bovine aprotinin in reducing blood loss in coronary artery bypass graft surgery.

DESIGN

An open-label, randomized, controlled study evaluating two dosage levels of recombinant aprotinin.

SETTING

Two acute care hospitals (Northwestern Memorial Hospital, Chicago, Ill., and the Scott & White Memorial Hospital, Temple, Texas).

PATIENTS

Patients undergoing primary and reoperation coronary artery bypass grafting were assigned to groups by means of a computer-generated table of random numbers. Treated (n = 48) and control (n = 36) patients did not differ significantly in age, sex, weight, number of grafts, or preoperative hemoglobin level.

INTERVENTIONS

Recombinant aprotinin was given at two dosages. Dosage level 1 consisted of a bolus of 2 mg/kg intravenously immediately after the induction of anesthesia, 1 mg/kg added to each liter of the oxygenator prime, and 0.5 mg.kg-1.hr-1 infused continuously during operation. At dosage level 2, doses were doubled. Intraoperative monitoring of anti-factor Xa activity was performed, and additional doses of heparin were given on the basis of anti-factor Xa results.

MAIN OUTCOME MEASURES

Preoperative and postoperative hemoglobin levels, amounts of autotransfusion device and chest tube drainage blood, and transfusions of allogeneic red blood cells. Adverse clinical events (alterations in renal function, graft thrombosis, myocardial infarction, and death) were recorded.

RESULTS

Additional heparin was given to 48% patients in the aprotinin group and to 44% of control patients. Overall red blood cell loss (in milliliters, mean +/- standard deviation [SD]) was decreased with aprotinin at dosage level 1 for reoperations (1040 +/- 162 vs 1544 +/- 198, p < 0.01), and at dosage level 2 for all operations (primary operations, 886 +/- 362 vs 1333 +/- 618, p = 0.02; reoperations, 1191 +/- 560 vs 1815 +/- 1116, p = 0.2). Fewer patients in the aprotinin than in the control group had transfusions of donated blood (6/48 vs 12/36, p = 0.02) or reinfusion of chest tube drainage blood (12/48 vs 20/36, p < 0.01). Among patients receiving dosage level 1, there were no myocardial infarctions or deaths. At dosage level 2, one patient had profound bradycardia and died on day 12 and two patients had late graft closures. Two control patients had hypotension after bypass necessitating intraaortic balloon pumps, and one of these patients died. Postoperative increases in blood urea nitrogen and creatinine levels were small in both aprotinin and control groups. No hypersensitivity or other allergic reactions occurred.

CONCLUSION

We conclude that, at the dosages given, recombinant bovine aprotinin decreases surgical blood loss and transfusion requirements in patients undergoing coronary artery bypass grafting, but its use requires appropriate monitoring of heparin use during bypass. Whether higher dosages of aprotinin increase the risk of graft thrombosis must be further assessed with a larger patient sample.

Physiological responses, organ distribution, and circulation kinetics in anesthetized rats after hypovolemic exchange transfusion with technetium-99m-labeled liposome-encapsulated hemoglobin

Physiological responses and circulation properties of liposome-encapsulated hemoglobin (LEH) labeled with technetium-99m (99mTc) were measured in rats after a 10% (170 mg/kg hemoglobin; 430 mg/kg phospholipid) or a 50% (450 mg/kg hemoglobin, 2.3 g/kg phospholipid) hypovolemic exchange transfusion (n = 5 per exchange group). Mean arterial pressure returned to baseline values (105 +/- 8 mmHg) by 90 min post-infusion for both groups. By 20 h, mean arterial pressure remained at baseline values for the 10% group, but dropped to 30 +/- 14 mmHg for the 50% group. For both groups, bradycardia was seen after the exchange period, but heart rate recovered by 30 min for the 10% group and by 90 min for the 50% group. The 99mTc-LEH remained in circulation longer for the 50% group (18.2 h half-life) than for the 10% group (2.4 h half-life). Removal of 99mTc-LEH from the bloodstream was via the liver and spleen. At 20 h, 99mTc-LEH accumulation in these organs was greater for the 10% group (liver, 36.2 +/- 1.7%; spleen, 37.5 +/- 2.5%) than for the 50% group (liver, 17.0 +/- 1.4%; spleen, 17.1 +/- 1.4%). The data show that there is less clearance of 99mTc-LEH from the bloodstream by the reticuloendothelial system after a 50% hypovolemic exchange transfusion, thus supporting the possible use of LEH as an oxygen-carrying resuscitative fluid in situations of severe blood loss.

Allogeneic marrow transplantation following cyclophosphamide and escalating doses of hyperfractionated total body irradiation in patients with advanced lymphoid malignancies: a Phase I/II trial

PURPOSE

To define the maximum tolerated dose (MTD) of unshielded total body irradiation (TBI) delivered from dual 60C sources at an exposure rate of 0.08 Gy/min and given in thrice daily fractions of 1.2 Gy in patients with advanced lymphoid malignancies.

METHODS AND MATERIALS

Forty-four patients with a median age of 28 (range 6-48) years were entered into a Phase I/II study. All patients received cyclophosphamide (CY), 120 mg/kg administered over 2 days before TBI. Marrow from human leukocyte antigen (HLA) identical siblings was infused following the last dose of TBI. An escalation-deescalation schema designed to not exceed an incidence of 25% of Grade 3-4 regimen-related toxicities (RRTs) was used. The first dose level tested was 13.2 Gy followed by 14.4 Gy.

RESULTS

None of the four patients at the dose level of 13.2 Gy developed Grade 3-4 RRT. Two of the first eight patients receiving 14.4 Gy developed Grade 3-4 RRT, establishing this as the MTD. An additional 32 patients were evaluated at the 14.4 Gy level to confirm these initial observations. Of 40 patients receiving 14.4 Gy, 13 (32.5%) developed Grade 3-4 RRTs; 46% in adults and 12% in children. The primary dose limiting toxicity was Grade 3-4 hepatic toxicity, which occurred in 12.5% of patients. Noninfectious Grade 3-4 interstitial pneumonia syndrome occurred in 5% of patients. The actuarial probabilities of event-free survival, relapse, and nonrelapse mortality at 2 years were 0.10, 0.81, and 0.47, respectively, for patients who received 14.4 Gy of TBI.

CONCLUSIONS

The outcome for patients receiving 14.4 Gy of TBI was not different from previous studies of other CY and TBI regimens in patients with advanced lymphoid malignancies. These data showed that the incidence of Grade 3-4 RRTs in adults was greater than the 25% maximum set as the goal of this study, suggesting that 13.2 Gy is a more appropriate dose of TBI for adults, while 14.4 Gy is an appropriate dose for children.

Allogeneic marrow grafts from donors with congenital chromosomal abnormalities in marrow cells

To determine whether siblings with chromosomal abnormalities in marrow cells which are associated with cellular defects (e.g. Down syndrome or heterozygosity for Fanconi syndrome) are suitable donors for allogeneic bone marrow transplants, we have reviewed the patient files at the Fred Hutchinson Cancer Research Center (FHCRC) and carried out a survey among member centres of the International Bone Marrow Transplant Registry (IBMTR). The 57 of 253 (23%) member centres which responded to the survey reported seven transplants from donors with the following conditions: Down syndrome (n = 2), suspected heterozygotes for Fanconi syndrome (n = 3), and 47,XXX syndrome (n = 2), among a total of 5,561 allogeneic transplants from HLA-identical siblings. Adding the three cases seen at the Fed Hutchinson Cancer Research Center among 2,927 HLA-identical sibling transplants during 1992 resulted in 10 transplants among 8,488 cases transplanted overall: four with Down syndrome, four suspected of being heterozygous for Fanconi syndrome, and two trisomy X. Three out of four grafts from siblings with Down syndrome had complications, including poor graft function (n = 2) and graft failure (n = 1). Two of four recipients of marrow from presumed Fanconi syndrome heterozygotes presented with poor graft function and a third recipient developed graft failure after initial evidence of engraftment. The two patients given marrow from siblings with 47,XXX syndrome engrafted uneventfully. The experience reported here shows a low frequency of encountering an HLA-identical sibling donor who has chromosomal abnormalities in marrow cells consistent with Down syndrome or heterozygosity for Fanconi syndrome, about one case among 1,000 transplants. The much higher than expected incidence of graft problems with marrow from such a donor would make it reasonable to look either for an alternative marrow donor or consider an autologous transplant, in case a sibling marrow donor with Down syndrome or heterozygosity for Fanconi syndrome is encountered, although a donor with trisomy X seems acceptable.

Osmotic pressure method to measure salt induced folding/unfolding of bovine serum albumin

A new approach has been developed to monitor protein folding by utilizing osmotic pressure and a range of salt concentrations in a well characterized protein, bovine serum albumin (BSA). It is hypothesized that both the 'effective' osmotic molecular weight, Ae, and the solute/solvent interaction parameter, I, in the empirical relation Msolvent/Msolute = (RT rho/Ae)1/pi + I [1] can be used as measures of protein folding. I is a measure of solvent perturbed by the solute and is thought to depend directly upon the solvent accessible surface area (ASA). It is reasoned that larger solvent accessible surface area of an unfolded or denatured protein should perturb more water and produce larger I-values. Thus I-values allow calculation of a unfolded protein fraction, fua, due to changes in relative solvent accessible surface area. It has been observed that Ac decreases for filamentous, denatured proteins due to segmental motion of the molecule [2]. This allows calculation of unfolded protein fraction from the effective molecular weight, fum. Colloid osmotic pressure of BSA was measured in a range of salt concentrations at 25 degrees C, and pH = 7 (above the isoelectric point of BSA at pH = 5.4). Both S and I were used to monitor protein folding as the salt concentration was varied. In general, larger and variable I-values and smaller Ae were observed at salt concentrations less than 50 mmolal NaCl (Imax = 8.9), while constant I = 4.1 and Ae = 66,500 were observed above 50 mmolal NaCl. The two expressions for fractional unfolding (fua and fum) are in general agreement. Small differences in the parameters below 50 mmolal salt concentration are explained with well known shifts in the relative amounts of alpha-helix, beta-sheet and random coil in denatured BSA. The relative amounts of these shifts agree with predictions in the literature attributed to continuous BSA expansion rather than an 'all-or-none' conversion.

Influence of total nucleated cell dose from marrow harvests on outcome in patients with acute myelogenous leukemia undergoing autologous transplantation

This retrospective study was conducted to determine whether the total number of nucleated cells (TNC)/kg collected at marrow harvest was associated with outcome in 151 patients with acute myelogenous leukemia (AML) who received an autologous purged (n = 67) or non-purged (n = 84) marrow transplant. At the time of transplant 33 patients were in first complete remission (CR), 47 in second CR, 54 in first relapse and 17 beyond second CR. Ninety patients received busulfan (BU) 16 mg/kg and cyclophosphamide (CY) 120 or 200 mg/kg, 51 patients received CY 120 mg/kg and total body irradiation (TBI) 12-15.75 Gy and 10 patients received BU 8 mg/kg, CY 60 mg/kg and TBI 12 Gy as conditioning regimens. Patients whose marrow harvest yielded < 2 x 10(8) TNC/kg did not undergo purging with 4-hydroperoxycyclophosphamide (4HC). This group of patients (n = 28) had a 100 day mortality of 50% and only 54% achieved a granulocyte levels of > 0.5 x 10(9)/l and 29% achieved platelet transfusion independence. Patients whose marrow harvest yielded 2-4 x 10(8) TNC/kg and did not undergo marrow purging had a 20% mortality by day 100, 91% recovered granulocytes to > 0.5 x 10(9)/l and 61% became platelet independent. Patients whose marrow harvest yielded 2-4 x 10(8) TNC/kg and underwent marrow purging with 4HC had a 50% mortality by day 100 and 58% achieved a granulocyte levels of > 0.5 x 10(9)/l and 42% became platelet transfusion independent.(ABSTRACT TRUNCATED AT 250 WORDS)

Rapid engraftment after autologous transplantation utilizing marrow and recombinant granulocyte colony-stimulating factor-mobilized peripheral blood stem cells in patients with acute myelogenous leukemia

This study was performed to determine whether peripheral blood stem cells (PBSCs) mobilized with recombinant granulocyte-colony stimulating factor (rhG-CSF) increase the tempo of granulocyte and platelet recovery when added to marrow in patients with acute myelogenous leukemia (AML) undergoing autologous bone marrow transplantation (BMT). Twenty six patients with AML had bone marrow harvested in first (n = 16) or second (n = 10) complete remission (CR) and cryopreserved. Patients received rhG-CSF alone (n = 20) or rhG-CSF following chemotherapy (n = 6). PBSCs were collected from 24 of the 26 patients a median of 7 (range 3-2130) days after marrow harvest. Two patients presumed to be in second CR did not have PBSCs collected because of early relapse. Fourteen patients in first CR (n = 3), second CR (n = 8) or first relapse (n = 3) proceeded to autologous BMT utilizing marrow + rhG-CSF-mobilized PBSCs. Engraftment parameters were compared with a historical group of 158 patients with AML who had received purged (n = 67) or unpurged (n = 91) autologous BMT without PBSCs. The median number of peripheral blood total nucleated and CD34+ cells collected from 24 patients was 19.55 x 10(8)/kg (range 1.83-54.83) and 5.59 x 10(6)/kg (1.23-34.79), respectively. All patients transplanted achieved a granulocyte level of > 0.5 x 10(9)/l with a median of 13 days (range 11-27 days) and platelets to 20 x 10(9)/l median 14 days (range 9-83 days).(ABSTRACT TRUNCATED AT 250 WORDS)

Transplantation of allogeneic peripheral blood stem cells mobilized by recombinant human granulocyte colony-stimulating factor

Peripheral blood stem cells (PBSCs) are widely used in autologous transplantation because of ease of collection and rapid hematopoietic reconstitution. However, PBSCs have rarely been used for allogeneic transplantation because of concerns about donor toxicities from cytokine administration and the theoretical increased risk of graft-versus-host-disease (GVHD) from the large number of T cells infused. Eight patients with advanced malignancies received allogeneic PBSC transplants from genotypically HLA-identical sibling donors. All donors received 5 days of recombinant human granulocyte colony-stimulating factor (rhG-CSF; 16 micrograms/kg/day) subcutaneously and were leukapheresed for 2 days. After treatment of the patient with total body irradiation and cyclophosphamide (n = 7) or etoposide, thiotepa, and cyclophosphamide (n = 1), PBSCs were infused immediately after collection and without modification. All patients received cyclosporine and either methotrexate (n = 6) or prednisone (n = 2) for GVHD prophylaxis, rhG-CSF was well tolerated with mild bone pain requiring acetaminophen occurring in two donors. All patients engrafted and in seven hematopoietic recovery was rapid, with 500 neutrophils/microL achieved by day 18 and 20,000 platelets/microL by day 12. Complete donor engraftment was documented by Y chromosome analysis in all four sex-mismatched donor-recipient pairs tested and by DNA analysis in two sex-matched pairs. One patient died on day 18 of veno-occlusive disease of the liver with engraftment but before chromosome analysis could be performed (results are pending in 1 patient). A second patient died of fungal infection 78 days after transplant. Grade 2 acute GVHD occurred in two patients and grade 3 GVHD occurred in one patient. One patient is 301 days from transplant in remission with chronic GVHD; the remaining five patients are alive and disease free 67 to 112 days after transplantation. Preliminary results indicate that allogeneic PBSCs mobilized by rhG-CSF can provide rapid hematologic recovery without an appreciably greater incidence of acute GVHD than would be expected with marrow. Further follow-up is required to determine the incidence of chronic GVHD and any potential beneficial effects on relapse after transplant.

HIV malingering in the accident and emergency department

This paper reports a number of cases of patients attending an accident and emergency (A&E) department claiming to be HIV positive when they have been tested negative and are known to be negative by other departments in the hospital. The reasons for these patients claims are not always apparent. These patients may place an inappropriate workload on an already busy department. We caution doctors working in A&E departments to be vigilant when dealing with patients who claim to be HIV positive when there are no clinical or laboratory findings to substantiate the claim and we recommend liaison between relevant departments within a hospital and the patient's general practitioner (GP) when dealing with these patients.

High-dose cyclophosphamide, carmustine, and etoposide followed by allogeneic bone marrow transplantation in patients with lymphoid malignancies who had received prior dose-limiting radiation therapy

PURPOSE

To evaluate a high-dose chemotherapy regimen without total-body irradiation (TBI) followed by allogeneic (allo) bone marrow transplantation (BMT) in patients with lymphoid malignancies who had received prior dose-limiting radiotherapy.

PATIENTS AND METHODS

Fifty-six patients with non-Hodgkin's lymphoma (NHL, n = 26), Hodgkin's disease (HD, n = 17), or acute lymphoblastic leukemia (ALL, n = 13) with a history of previous radiation therapy were treated with cyclophosphamide (7.2 g/m2), carmustine (300 mg/m2 or 600 mg/m2), and etoposide (2,400 mg/m2; CBV) followed by allo BMT.

RESULTS

Nine of 56 patients are alive and disease-free a median of 1,091 (range, 512 to 1,784) days post-transplant. The probabilities of transplant-related mortality, relapse, and event-free survival at 2 years for the entire group of 56 patients were .62, .59, and .17, respectively. Patients who received 600 mg/m2 of carmustine had a higher incidence of grade 3 or 4 regimen-related toxicities (RRTs) (14 of 22) than did patients who received 300 mg/m2 (12 of 33; P < .04), whereas there was no difference in relapse (.34 and .53, respectively, P = .73). Fourteen of 16 patients who received allo BMT for advanced disease (n = 12) or less-advanced disease (n = 4) but who were also eligible for auto BMT relapsed (n = 4) or died of transplant-related complications (n = 10).

CONCLUSIONS

Allo BMT following a high-dose CBV regimen resulted in long-term disease-free survival in 17% of patients with lymphoid malignancies who had received prior dose-limiting radiotherapy. A high incidence of transplant-related complications, especially fatal idiopathic pneumonia syndrome (IPS) and a high relapse rate limited success. Morbidity and mortality associated with carmustine 600 mg/m2 were high and were not associated with a decrease in relapse. The number of patients in this study eligible for either allo or auto BMT was limited and precluded meaningful analysis of relative effectiveness.

Effect of graft-versus-host disease prophylaxis on relapse in patients transplanted for acute myeloid leukemia

Between November 1978 and September 1988, 184 patients with acute myeloid leukemia in first remission received marrow transplants from HLA-identical siblings after conditioning with 120 mg/kg of cyclophosphamide and 12.0 Gy fractionated total body irradiation. Patients received either cyclosporine (CYA, n = 59), methotrexate (MTX, n = 82), or MTX + CYA (n = 43 as graft-versus-host disease (GVHD) prophylaxis. The probabilities of grades II-IV acute GVHD after CYA, MTX or MTX+CYA were 0.43, 0.48 and 0.28, respectively (p = 0.06). The probability of non-relapse mortality was 0.53, 0.50 and 0.42 at 4 years in patients treated with CYA, MTX, or MTX + CYA, respectively. The probability of relapse was 0.24 in patients receiving CYA, 0.24 in patients receiving MTX and 0.44 in patients receiving MTX + CYA (p = 0.02). The probability of survival at 4 years was 0.54 with CYA, 0.51 with MTX and 0.45 with MTX + CYA. A multivariate analysis of risk factors for relapse examined age, WBC at diagnosis, blast count at diagnosis, percentage of marrow blasts, FAB subtype, the number of remission induction courses to achieve a remission, maintenance therapy, consolidation therapy, marrow cell dose, donor-recipient sex, GVHD prophylaxis regimen and isolation and decontamination in laminar airflow rooms. GVHD prophylaxis with MTX + CYA was independently significantly associated with an increased risk of relapse (relative risk 2.25, p = 0.01). Acute GVHD was associated with increased non-relapse mortality (RR = 3.58, p < 0.0001). The administration of MTX + CYA did not adversely affect survival because patients receiving this regimen experienced less mortality from causes other than relapse when compared with patients receiving either CYA or MTX alone.

Plasma melatonin concentration in neonatal northern elephant seals, Mirounga angustirostris

The development of pineal function in northern elephant seals was examined in an attempt to understand the physiological basis for previously observed high daytime levels of melatonin in neonatal southern elephant seals. Pineal glands from four northern elephant seal pups, estimated age less than 1 week, weighted 3.0 +/- 0.80 g, which was significantly less than that previously found in southern elephant seals (4.6 +/- 0.35 g). Midday concentrations of plasma melatonin in pups averaged more than 3000 pmol/l in the first 5 days post-partum, but declined rapidly to less than 400 pmol/l after day 9. Daytime melatonin levels in northern elephant seals tended to be lower than in southern elephant seals, although they were very high compared with other species. A circadian cycle of plasma melatonin concentration was observed in newborn northern elephant seals, with levels of 3000-5000 pmol/l during the day, rising to more than 10,000 pmol/l late in the dark phase. Soon after weaning at 4 weeks of age, daytime and night-time levels were in the range 60-100 pmol/l and 100-400 pmol/l, respectively. When approximately 10 weeks old, most samples were in the range 100-400 pmol/l with no discernible difference between day and night levels. The results do not support the hypothesis that the pineal gland is involved in thermogenesis in new-born southern elephant seals. Instead, the very active pineal gland may contribute to energy conservation, by lowering body temperature, particularly at night. As physical insulation is acquired by the deposition of blubber, the mechanism is not required and melatonin falls to adult levels.

Structural requirements for the utilization of ascorbate analogues in the prolyl 4-hydroxylase reaction

The ability of structural analogues of ascorbate to serve as substitutes for this reducing agent in the prolyl 4-hydroxylase reaction was studied. In experiments using the purified enzyme, variations of the compounds' side chain were compatible with co-substrate activity. The presence of very large hydrophobic substituents or a positively charged group caused an increase in the observed Km values. A negative charge and smaller modifications did not change the affinity to the enzyme when compared with L-ascorbate. 6-Bromo-6-deoxy-L-ascorbate had a lower Km than the physiological reductant. Substitution at the -OH group in ring position 3 prevented binding to the enzyme. The same pattern of activity was observed when the full and uncoupled prolyl 4-hydroxylase reactions were studied. The Vmax. values with all compounds were similar. The reaction of microsomal prolyl 4-hydroxylase was supported by D-isoascorbate, O6-tosyl-L-ascorbate and 5-deoxy-L-ascorbate, giving the same dose-response behaviour as L-ascorbate itself. Again, 6-bromo-6-deoxy-L-ascorbate gave a lower Km and a similar Vmax. value. L-Ascorbic acid 6-carboxylate produced substrate inhibition at concentrations above 0.3 mM. The Km and Vmax. values calculated from concentrations up to 0.2 mM were similar to those of L-ascorbate. The enzyme activity observed with 6-amino-6-deoxy-L-ascorbate was very low in the microsomal hydroxylation system. The calculated Vmax. value was lower than that of L-ascorbate, suggesting a restriction of the access of this compound to the enzyme.

Circulation profile of technetium-99m labeled liposome encapsulated hemoglobin in a 10% or 50% rat hypovolemic shock model

The circulation kinetics and organ biodistribution of liposome encapsulated hemoglobin (LEH) was determined non-invasively in hypovolemic rats using a technetium-99m (Tc-99m) liposome labeling procedure. Rats with an indwelling catheter had either 10% or 50% of their blood volume removed and replaced with an equal volume of LEH labeled with Tc-99m (Tc-99m LEH). Mean arterial pressures and heart rates were monitored throughout the experiment. Gamma camera images were acquired during the first 90 minutes following infusion of the Tc-99m LEH and at 20 hours post-infusion. Blood capillaries were drawn at various times to monitor Tc-99m activity and the amount of LEH remaining in circulation. There were significant differences in the kinetics and biodistribution for the two groups. In the 10% group, the LEH was removed quickly from circulation with only 0.9% remaining at 20 hours, while the 50% group had 51.2% at 20 hours. The liver and spleen were the major organs responsible for LEH clearance. The 20 hour biodistribution by tissue sampling showed that the 10% group had 37.6% in the liver and 34.3% in the spleen, while the 50% group had only 18.4% in the liver and 14.6% in the spleen.

Salmonella enteritidis in eggs from commercial chicken layer flocks implicated in human outbreaks

Eggs were cultured from four commercial chicken layer houses implicated in three human outbreaks of Salmonella enteritidis serotype enteritidis infection as part of the activities of the USDA-APHIS, VS, Salmonella enteritidis Task Force. Each house was part of a multiple in-line complex, ranging from three to seven houses. Houses were located on three separate farms, and each house contained between 50,000 and 80,000 chickens. S. enteritidis phage types 8, 13a, and 23 were isolated from samples taken from environmental and organ tissue samples, but only phage type 8 was cultured from eggs. Phage type 8 was isolated from humans in all three S. enteritidis outbreaks. Frequency estimates of contaminated eggs ranged from 0.03% to 0.90%.

From science to evidence: the testimony on causation in the Bendectin cases

Critics of American tort law often question the ability of lay jurors to make factual determinations in trials involving complex scientific evidence. In this article, Professor Sanders attempts to refocus tort reform debate by studying how trial procedures themselves contribute to jurors' inability to properly assess scientific evidence. Professor Sanders' analysis centers on trials involving Bendectin, a drug which plaintiffs have claimed caused birth defects in the children of mothers who took it during pregnancy. After noting that the weight of scientific and federal judicial opinion concludes that plaintiffs cannot establish a causal link between Bendectin use and birth defects by a preponderance of the evidence, Professor Sanders analyzes the transcripts of six Bendectin trials to determine why jury verdicts do not comport with the weight of scientific and judicial opinion. Based on his conclusion that trials are incapable of adequately conveying the weight of scientific opinion to a lay jury, he evaluates the ability of various trial reform proposals to ameliorate this problem. Finally he recommends adopting proposals that would facilitate jurors' understanding of scientific evidence and lead to verdicts consistent with the weight of scientific opinion.

Autologous bone marrow transplantation for acute lymphoblastic leukemia

Between December 1979 and February 1991, 89 patients with ALL received autologous BMT. Median patient age was 18.4 years. Ten patients were in first remission, 52 were in second or greater remission and 27 were in relapse at the time of transplant. Conditioning regimens utilized chemotherapy alone (5 patients) or in combination with 10-15.75 Gy total body irradiation (84 patients). Disease-free survival at 1 year is 50% for patients transplanted in first remission, 27% for those in > or = second remission and 8% for patients in relapse. Pre- and post-transplant variables were evaluated in univariate and multivariate analyses for their effect on survival and relapse. Factors significantly associated with improved survival were being transplanted in first remission and achieving a self-sustained platelet count > or = 20 x 10(9)/l in a shorter period of time. A decreased relapse rate after transplant was associated with a lower white blood count at diagnosis, being transplanted in first remission and not being transplanted in relapse.