Identification of clinical factors impacting outcome in patients undergoing autologous hematopoietic cell transplantation after BEAM and TEAM conditioning

Organ dysfunction, including pulmonary function impairment, plays a key role in the choice of conditioning chemotherapy before autologous hematopoietic stem cell transplantation (auto-HSCT). Replacement of BCNU/carmustine as part of BEAM (BCNU/carmustine, etoposide, cytarabine, and melphalan) conditioning protocol by thiotepa (TEAM) reduces pulmonary toxicity while maintaining efficacy. We retrospectively analyzed the association of clinical characteristics, comorbidities, and organ function with outcomes after conditioning with BEAM or TEAM. Three hundred ninety-six patients undergoing auto-HSCT (n = 333 with BEAM; n = 63 with TEAM) at our institution between 2008 and 2021 were included in this study. In the multivariate analysis, CO-diffusion capacity corrected for hemoglobin (DLCOcSB) ≤ 60% of predicted, progressive disease (PD) before auto-HSCT, Karnofsky performance score (KPS) ≤ 80%, HCT-CI score ≥ 4, and cardiac disease before auto-HSCT were associated with decreased overall survival (OS) in patients treated with BEAM. In contrast, only PD before auto-HSCT was identified in patients treated with TEAM. Patients conditioned with BEAM and DLCOcSB ≤ 60% had higher non-relapse mortality, including pulmonary cause of death. In summary, we have identified clinical and pulmonary risk factors associated with worse outcomes in patients conditioned with BEAM compared to TEAM. Our data suggest TEAM conditioning as a valid alternative for patients with comorbidities, including pulmonary dysfunction and/or poorer performance scores, before auto-HSCT.

Treosulfan Exposure Predicts Thalassemia-Free Survival in Patients with Beta Thalassemia Major Undergoing Allogeneic Hematopoietic Cell Transplantation

A toxicity-reduced conditioning regimen with treosulfan, fludarabine, and thiotepa in patients with high-risk β-thalassemia major has significantly improved hematopoietic stem cell transplantation (HCT) outcomes. However, complications resulting from regimen-related toxicities (RRTs), mixed chimerism, and graft rejection remain a challenge. We evaluated the dose-exposure-response relationship of treosulfan and its active metabolite S, S-EBDM, in a uniform cohort of patients with β-thalassemia major to identify whether therapeutic drug monitoring (TDM) and dose adjustment of treosulfan is feasible. Plasma treosulfan/S, S-EBDM levels were measured in 77 patients using a validated liquid chromatography with tandem mass spectrometry method, and the pharmacokinetic parameters were estimated using nlmixr2. The influence of treosulfan and S, S-EBDM exposure, and GSTA1/NQO1 polymorphisms on graft rejection, RRTs, chimerism status, and 1-year overall survival (OS), and thalassemia-free survival (TFS) were assessed. We observed that treosulfan exposure was lower in patients with graft rejection than those without (1,655 vs. 2,037 mg•h/L, P = 0.07). Pharmacodynamic modeling analysis to identify therapeutic cutoff revealed that treosulfan exposure ≥1,660 mg•hour/L was significantly associated with better 1-year TFS (97% vs. 81%, P = 0.02) and a trend to better 1-year OS (90% vs. 69%, P = 0.07). Further, multivariate analysis adjusting for known pre-HCT risk factors also revealed treosulfan exposure <1,660 mg•h/L (hazard ratio (HR) = 3.23; 95% confidence interval (CI) = 1.12-9.34; P = 0.03) and GSTA1*B variant genotype (HR = 3.75; 95% CI = 1.04-13.47; P = 0.04) to be independent predictors for inferior 1-year TFS. We conclude that lower treosulfan exposure increases the risk of graft rejection and early transplant-related mortality affecting TFS. As no RRTs were observed with increasing treosulfan exposure, TDM-based dose adjustment could be feasible and beneficial.

Reduced-Intensity Compared to Nonmyeloablative Conditioning in Patients with Non-Hodgkin Lymphoma Undergoing Allogeneic Hematopoietic Stem Cell Transplantation

Reduced-intensity conditioning (RIC) and nonmyeloablative (NMA) conditioning are preferred for patients with non-Hodgkin lymphoma (NHL) undergoing allogeneic hematopoietic stem cell transplantation (allo-HCT). Although prior studies have suggested that higher-intensity regimens in RIC-NMA conditioning are associated with inferior outcomes in patients with NHL, the optimal conditioning regimen remains unknown. We performed a retrospective single-center analysis to determine outcomes of adult patients with B cell and T cell NHL who underwent allo-HCT and received either RIC or NMA conditioning between March 2008 and December 2019. RIC regimens included fludarabine-cyclophosphamide-thiotepa-4 Gy-total body irradiation (Flu-Cy-TT-4Gy-TBI), fludarabine-melphalan (Flu-Mel), fludarabine-cyclophosphamide-4 Gy-total body irradiation (Flu-Cy-4Gy-TBI), and fludarabine-busulfan-4 (Flu-Bu-4). The NMA regimen comprised fludarabine-cyclophosphamide-2 Gy-total body irradiation (Flu-Cy-2Gy-TBI). The primary outcome was overall survival (OS); secondary outcomes included progression-free survival (PFS), nonrelapse mortality (NRM), and the incidence of acute and chronic graft-versus-host-disease (GVHD). Of 279 transplants recipients (median age, 58 years), 110 received RIC (55% Flu-Mel, 38% Flu-Cy-TT-4Gy-TBI, 6% Flu-Bu-4, 1% Flu-Cy-4Gy-TBI) and 169 received NMA conditioning with Flu-Cy-2Gy-TBI. With a median of 64 months of follow-up post-allo-HCT, there was no significant difference in OS between the NMA and RIC groups (median, not reached [NR] versus 103 months; P = .1), and this was maintained on multivariable analysis. Similarly, after adjustment for all independently significant covariates (age, Karnofsky Performance Status [KPS], Hematopoietic Cell Transplantation Comorbidity Index [HCT-CI], and disease histology), the regression analysis showed no significant difference in PFS with RIC compared to NMA conditioning (hazard ratio [HR] 1.38; 95% confidence interval [CI], .92 to 2.09; P = .24). On univariable analysis, there was no significant difference in NRM between the RIC and NMA arms (100-day estimate, 10.0% versus 1.8%; P = .5). After adjustment for age, ethnicity, KPS, HCT-CI, GVHD prophylaxis, and donor source, RIC conditioning was associated with a significantly higher incidence of NRM compared to NMA conditioning (HR, 2.61; 95% CI, 1.04 to 6.52; P = .039). On multivariable analysis, compared with the NMA arm, the RIC arm had higher rates of grade II-IV (HR, 2.25; 95% CI, 1.31 to 3.86; P = .002) and grade III-IV acute GVHD (HR, 5.62; 95% CI, 2.03 to 15.6; P < .001). The findings of this study suggest that NMA conditioning with Flu-Cy-TBI-2Gy may be considered over more intensive RIC regimens for patients with NHL undergoing allo-HCT.

Thiotepa, Busulfan, Cyclophosphamide: Effective but Toxic Conditioning Regimen Prior to Autologous Hematopoietic Stem Cell Transplantation in Central Nervous System Lymphoma

In primary central nervous system lymphoma, two-year progression-free survival rates of up to 63 percent have been reported for first-line autologous stem cell transplantation after conditioning with the thiotepa busulfan cyclophosphamide regimen. However, 11 percent of the patients died due to toxicity. Besides conventional survival, progression-free survival and treatment related mortality analyses, a competing-risk analysis was applied to our cohort of twenty-four consecutive patients with primary or secondary central nervous system lymphoma who underwent autologous stem cell transplantation after thiotepa busulfan cyclophosphamide conditioning. The two-year overall survival and progression-free survival rates were 78 percent and 65 percent, respectively. The treatment-related mortality rate was 21 percent. The competing risks analysis demonstrate that age 60 or over and the infusion of less than 4.6 × 106/kg CD34+ stem cells were significant adverse prognostic factors for overall survival. Autologous stem cell transplantation with thiotepa busulfan cyclophosphamide conditioning was associated with sustained remission and survival. Nevertheless, the intensive thiotepa busulfan cyclophosphamide conditioning regimen was highly toxic, especially in older patients. Thus, our results suggest that future studies should aim at identifying the subgroup of patients who will really benefit of the procedure and/or to reduce the toxicity of future conditioning regimen.

Decreasing Skin Breakdown Around Central Lines in Patients Receiving Thiotepa Prior to Bone Marrow Transplantation

Skin breakdown occurring around central line dressings increases the risk for infection and bacteremia in all patients. The risk is magnified when experienced in pediatric patients receiving marrow-ablative therapy. A staff nurse on an inpatient pediatric oncology and bone marrow transplant unit noted an increased incidence of skin breakdown around central line dressings in patients receiving Thiotepa prior to bone marrow transplantation. Although there is a wealth of information surrounding routine care of central venous access devices, there is little evidence surrounding care with impaired skin integrity. A staff nurse turned to expert opinion and consensus revealed the use of nonocclusive dressings for central lines. A new protocol for changing central line dressings was developed to decrease the rate of skin breakdown. The protocol utilized gauze and a self-adherent wrap instead of tape to secure central lines. Bone marrow transplant staff nurses were educated prior to the practice change, and compliance was monitored through observation and review of documentation in the electronic medical record. A retrospective chart review compared the rate of skin breakdown and central line associated blood stream infections pre- and postpractice change. The overall percentage of skin breakdown surrounding central lines was reduced by over 80%.

Optimizing MATRix as remission induction in PCNSL: de-escalated induction treatment in newly diagnosed primary CNS lymphoma

BACKGROUND

Primary diffuse large B-cell lymphoma (DLBCL) of the central nervous system (PCNSL) is a rare disorder with an increasing incidence over the past decades. High-level evidence has been reported for the MATRix regimen (high-dose methotrexate (HD-MTX), high-dose AraC (HD-AraC), thiotepa and rituximab) followed by high-dose chemotherapy and autologous stem cell transplantation (HCT-ASCT) supporting this approach to be considered a standard therapy in newly diagnosed PCNSL patients ≤ 70 years. However, early treatment-related toxicities (predominantly infectious complications), occurring in up to 28% per MATRix cycle, diminish its therapeutic success. Furthermore, sensitivity to first-line treatment is an independent prognostic factor for improved overall survival (OS) in PCNSL. Thus, patients achieving early partial remission (PR) after 2 cycles of MATRix might be over-treated with 4 cycles, in the context of consolidation HCT-ASCT.

METHODS

This is an open-label, multicentre, randomized phase III trial with two parallel arms. 326 immunocompetent patients with newly diagnosed PCNSL will be recruited from 37 German, 1 Austrian and 12 UK sites. Additional IELSG (International Extranodal Lymphoma Study Group) sites are planned. The objective is to demonstrate superiority of a de-escalated and optimised remission induction treatment strategy, followed by HCT-ASCT. Randomization (1:1) will be performed after completion of all screening procedures. Patients in Arm A (control treatment) will receive 4 cycles of MATRix. Patients in Arm B (experimental treatment) will receive a pre-phase (R/HD-MTX), followed by 2 cycles of MATRix. Patients in both arms achieving PR or better will proceed to HCT-ASCT (BCNU, thiotepa). The primary endpoint of the study is event-free-survival (EFS), defined as time from randomization to premature end of treatment due to any reason, lymphoma progression or death whichever occurs first. Secondary endpoints include OS, progression free survival (PFS), toxicity, neurocognitive impairment and quality of life. Minimal follow-up is 24 months.

DISCUSSION

Current treatment options for PCNSL in patients ≤ 70 years have improved remarkably over recent years. However, the potential efficacy benefits are offset by an increased incidence of short-term toxicities which can impact on treatment delivery and hence on survival outcomes. In patients ≤ 70 years with newly diagnosed PCNSL addressing the need to reduce treatment-related toxicity by de-escalating and optimising the induction phase of treatment, is a potentially attractive treatment strategy.

TRIAL REGISTRATION

German clinical trials registry DRKS00022768 registered June 10th, 2021.

Enhanced Luminescent Detection of Circulating Tumor Cells by a 3D Printed Immunomagnetic Concentrator

Circulating tumor cells (CTCs) are an indicator of metastatic progression and relapse. Since non-CTC cells such as red blood cells outnumber CTCs in the blood, the separation and enrichment of CTCs is key to improving their detection sensitivity. The ATP luminescence assay can measure intracellular ATP to detect cells quickly but has not yet been used for CTC detection in the blood because extracellular ATP in the blood, derived from non-CTCs, interferes with the measurement. Herein, we report on the improvement of the ATP luminescence assay for the detection of CTCs by separating and concentrating CTCs in the blood using a 3D printed immunomagnetic concentrator (3DPIC). Because of its high-aspect-ratio structure and resistance to high flow rates, 3DPIC allows cancer cells in 10 mL to be concentrated 100 times within minutes. This enables the ATP luminescence assay to detect as low as 10 cells in blood, thereby being about 10 times more sensitive than when commercial kits are used for CTC concentration. This is the first time that the ATP luminescence assay was used for the detection of cancer cells in blood. These results demonstrate the feasibility of 3DPIC as a concentrator to improve the detection limit of the ATP luminescence assay for the detection of CTCs.

Allogeneic Hemopoietic Stem Cell Transplants in Patients with Acute Myeloid Leukemia (AML) Prepared with Busulfan and Fludarabine (BUFLU) or Thiotepa, Busulfan, and Fludarabine (TBF): A Retrospective Study

This is a multicenter retrospective comparison of 2 myeloablative conditioning regimens in 454 patients with acute myeloid leukemia (AML) in remission: busulfan (4 days) and fludarabine (BUFLU) versus thiotepa, busulfan, and fludarabine (TBF). Eligible for this study were patients allografted between January 2008 and December 2018 in 10 transplant centers, with AML in first or second remission: 201 patients received BUFLU, whereas 253 received TBF. The 2 groups (BUFLU and TBF) were comparable for age (P = .13) and adverse AML risk factors (P = .3). The TBF group had more second remissions and more haploidentical grafts. The donor type included HLA-identical siblings, unrelated donors, and family haploidentical donors. The 5-year cumulative incidence of nonrelapse mortality (NRM) was 19% for BUFLU and 22% for TBF (P = .8), and the 5-year cumulative incidence of relapse was 30% and 15%, respectively (P = .0004). The 5-year actuarial survival was 51% for BUFLU and 68% for TBF (P = .002). In a multivariate Cox analysis, after correcting for confounding factors, the use of TBF reduced the risk of relapse compared with BUFLU (P = .03) and the risk of death (P = .03). In a matched pair analysis of 108 BUFLU patients matched with 108 TBF patients, with the exclusion of haploidentical grafts, TBF reduced the risk of relapse (P = .006) and there was a trend for improved survival (P = .07). Superior survival of patients receiving TBF as compared with BUFLU is due to a reduced risk of relapse, with comparable NRM. The survival advantage is independent of donor type and AML risk factors.

Successful engraftment and stable full donor chimerism after myeloablation with thiotepa, fludarabine, and melphalan and CD34-selected peripheral allogeneic stem cell transplantation in hemophagocytic lymphohistiocytosis

Allogeneic hematopoietic stem cell transplantation (HSCT) represents the only curative option for primary hemophagocytic lymphohistiocytosis (HLH), a rare disease of infants and young children, characterized by recurrent fever, hepatosplenomegaly, and cytopenia. We report a case of successful engraftment and stable full-donor chimerism in a patient with HLH who underwent peripheral allogeneic CD34-selected HSCT. The donor was his 1-antigen-HLA-mismatched grandmother. After a conditioning regimen based on the combination of thiotepa, fludarabine, melphalan, and rabbit antilymphocyte serum, the patient received a megadose of 26.3 x 10(6)/kg of CD34(+) peripheral blood cells. Neutrophil (>0.5 x 10(9)/L) and platelet (>50 x 10(9)/L) engraftment was observed on days +16 and +12, respectively, and the patient was discharged home on day +24. No acute or chronic GVHD was observed. Infectious complications were the main causes of re-hospitalization in the first year after transplantation, but no significant morbidity was observed thereafter. Thirty-two months after HSCT, the patient is alive and well, still in complete clinical remission of his underlying disease with a durable engraftment, normal NK activity and full donor chimerism. This case suggests that a fludarabine-based conditioning regimen and CD34-selected peripheral allogeneic HSCT may be a feasible option in case of unavailability of a fully HLA-matched related or unrelated donor.

Nonablative hematopoietic cell transplantation for the treatment of metastatic renal cell carcinoma

Nonablative hematopoietic cell transplantation (HCT) is becoming a preferred treatment for those recipients in whom the potential toxicity risk of standard ablative allogeneic therapy may be unacceptable. Graft-versus-malignancy effects may be generated against epithelial malignancies which are similar to the graft-versus-leukemia activity that is well documented in human hematological malignancies. Renal cell carcinoma has been shown to be responsive to immunotherapy with recombinant human cytokines and may be an ideal model for exploring this novel therapy. Clinical investigations have demonstrated regression of metastatic renal cell carcinoma occurs in some patients following nonablative allogeneic HCT. However, graft-versus-host disease remains a significant toxicity of nonablative transplantation, and further investigations are warranted to further evaluate this promising approach and to improve its safety.

STUDIES ON ANTIBODY PRODUCTION. XII. INHIBITION OF PRIMING BY DRUGS

The effect of drugs upon the primary and the secondary antibody response to diphtheria toxoid in mice was studied using an experimental system previously described. Triethylenethiophosphoramide (thio-TEPA), chloramphenicol, 6-mercaptopurine, 8-azaguanine, and versenate were found to inhibit, partially or completely,"priming" for the secondary response. Thio-TEPA, chloramphenicol, and 6-mercaptopurine, in doses exceeding those effective in inhibiting priming, did not cause alteration of the secondary response when given only during the secondary response. However, when chloramphenicol and amethopterin were given for 5 days prior to and at least 5 days after the second antigen injection, slight suppression of peak secondary titers occurred. Therefore, drug dosages effective in suppressing priming had less effect on the secondary response. It thus appears that there is a real difference between "priming" and the induction of antibody synthesis.

THE ASSAY OF THE EFFECT OF CHEMICAL AGENTS ON TUMOUR INVASION USING CHICK EMBRYOS

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The toxicity of radiotherapy following high-dose chemotherapy with peripheral blood stem cell support in high-risk breast cancer: a preliminary analysis

High-dose chemotherapy with autologous bone marrow and/or peripheral blood stem cell (PBSC) support is increasingly employed in the adjuvant treatment of high-risk breast cancer. Subsequent radiotherapy has been reported to be associated with morbidity and mortality resulting from pulmonary toxicity. In addition, the course of radiation therapy may be hampered by excess myelosuppression. The aim of this study was to investigate the contribution to radiation-induced toxicity of a high-dose chemotherapy regimen (CTC) that incorporates cyclophosphamide, thiotepa and carboplatin, in patients with high-risk breast cancer. In two randomised single institution studies, 70 consecutive patients received anthracycline-containing adjuvant chemotherapy (FEC: 5-fluorouracil, epirubicin and cyclophosphamide) followed by radiotherapy to achieve maximal local control. Of these patients, 34 received high-dose CTC with autologous PBSC support. All patients tolerated the full radiation dose in the planned time schedule. Radiation pneumonitis was observed in 5 patients (7%), 4 of whom had undergone high-dose chemotherapy (P = 0.38). All 5 responded favourably to prednisone. Fatal toxicities were not observed. Myelosuppression did not require interruption or untimely discontinuation of the radiotherapy, although significant reductions in median nadir platelet counts and haemoglobin levels were observed in patients who had received high-dose chemotherapy (P = 0.0001). The median nadir of WBC counts was mildly but significantly decreased during radiotherapy (P = 0.01). Red blood cell or platelet transfusions were rarely indicated. Adequate radiotherapy for breast cancer can be safely administered after high-dose CTC with autologous PBSC support. Radiation-induced myelotoxicity is clearly enhanced following CTC, but this is of little clinical significance. Radiation pneumonitis after high-dose therapy may occur more often in patients with a history of lung disease or after a relatively high radiation dose to the chest wall. Other high-dose regimens, particularly those incorporating drugs with known pulmonary toxicity (such as BCNU), may predispose patients to radiation pneumonitis.

Graft-versus-myeloma effect: proof of principle

The presence of a graft-versus-tumor effect has been well established in leukemia but not in multiple myeloma. A 40-year-old patient with myeloma refractory to standard chemotherapy and autologous transplantation received a matched unrelated T-cell-depleted transplant after conditioning with fractionated total-body irradiation, thiotepa, and cyclophosphamide. This procedure resulted in a transient and incomplete response with evidence of rapidly progressive disease within 2.5 months posttransplantation. The patient then received a small number of donor peripheral blood (PB) mononuclear cells (CD3 cells 1.2 x 10(6)/kg) without any further cytotoxic therapy. A complete remission was attained, lasting now for more than 14 months. The procedure was associated with severe acute and subsequently limited chronic graft-versus-host disease (GVHD). This report provides the first direct evidence of a graft-versus-myeloma effect after allogenic transplantation.

Is there any future for T-cell depleted bone marrow transplantation in chronic myeloid leukaemia?

There is no doubt that the poor reputation of T-cell depleted bone marrow transplant arises from its use in CML patients, where an increase in graft rejection and, above all, in leukaemia relapse has been reported by almost all centres. Evidence suggests that the standard conditioning regimen (once thought to be sufficiently immunosuppressive and myeloablative in unmanipulated transplants) should no longer be considered adequate when the immunological balance has shifted in favour of unopposed host-versus-graft reactivity and the GvL effect is lacking. Since GvHD remains the major problem in BMT, we suggest T-cell depletion should be considered the most effective method for GvHD prophylaxis but the cytoreductive effect of the conditioning regimens and the anti-leukaemia immune reactivity should be enhanced.

Arterial thrombosis associated with adjuvant chemotherapy for breast carcinoma: a Cancer and Leukemia Group B Study

PURPOSE

Multiagent chemotherapy and chemohormonal therapy for breast cancer are associated with an increased risk for venous thromboembolic complications. We observed instances of arterial thrombosis in two studies of breast cancer involving multiagent chemotherapy for stages II and III disease. Our purpose in this study was to determine the incidence of this complication and whether it appeared to be related to the chemotherapy or was a random event.

PATIENTS AND METHODS

Episodes of arterial thrombotic events were identified from record reviews of 1,014 assessable patients with breast cancer entered on two Cancer and Leukemia Group B protocols. Details of the kind of arterial event, when it occurred, the outcome, and the occurrence of metastases were analyzed.

RESULTS

Thirteen (1.3%) patients had an arterial thrombosis: six (5.3%) of 113 patients with stage III disease and seven (0.8%) of 901 patients with stage II disease. Four of these patients had a peripheral arterial thrombosis and nine had strokes (four were fatal). All these events occurred while the patients were receiving adjuvant chemotherapy. Only one additional arterial event (a stroke approximately four years later) has occurred in this patient group after chemotherapy was completed.

CONCLUSION

Arterial thrombosis is also associated with multiagent chemotherapy in patients with breast cancer. The mechanism is unknown.

Permeability of latex and polyvinyl chloride gloves to 20 antineoplastic drugs

Permeability of latex and polyvinyl chloride (PVC) gloves to 20 injectable antineoplastic drugs was studied. Four types of gloves were evaluated: latex surgical gloves, latex examination gloves, and PVC gloves in two thicknesses. Each glove material was exposed to each drug for 90 minutes, and permeation was tested using a mutagenicity assay. Individual fingertips of thin PVC gloves and latex surgical gloves were tested for permeability at five time points (2-30 minutes) using a doxorubicin coloration assay. All drugs permeated the thin PVC gloves. Latex surgical gloves were definitely permeable to two drugs (carmustine and thiotepa) and exhibited borderline permeability to mechlorethamine hydrochloride. The thick PVC gloves were definitely permeable to four drugs (carmustine, thiotepa, mechlorethamine hydrochloride, and daunorubicin hydrochloride) and exhibited borderline permeability to two drugs (doxorubicin and mercaptopurine). The latex examination gloves were permeable to carmustine, thiotepa, mechlorethamine hydrochloride, and cyclophosphamide. Doxorubicin permeation of individual fingertips of thin PVC gloves varied in time and amount. Doxorubicin did not permeate the latex surgical glove material, but testing with thiotepa showed that individual fingertips of this material also varied in permeability. Glove thickness was a major determinant of permeability; latex surgical gloves were the least permeable and thin PVC gloves the most permeable to the antineoplastic drugs tested. Within individual gloves and glove types, time and amount of permeation were not uniform.

[Teratogenic effect of thiophosphamide on mice of different genotypes]

It has been shown that 101/H mice differ from CBA mice by a higher sensitivity to the teratogenic action of the alkylating agent thiophosphamide.

Fragilitas ossium: a new autosomal recessive mutation in the mouse

Fragilitas ossium, fro, is an often lethal recessive mutation that was discovered in a randombred stock of mice after treatment with the chemical mutagen tris(1-aziridinyl) phosphine-sulphine. The fro/fro mice have osteoporosis-bending and fracture of the long bones-that is associated with apparently normal cartilage growth. The roentgenological and pathological features are similar to those of the severe, often lethal recessive form of human osteogenesis imperfecta.

[Role of conditionally pathogenic microbes in the development of experimental destructive pneumonia]

Experiments on 32 puppies with a preliminary decrease of immunologic resistance have demonstrated the possibility of the development of purulent destructive pneumonia under the effect of opportunistic microorganisms, such as Proteins, Escherichia coli, Pseudomonas aeruginosa. Histoenzymatic studies of a pathologically changed lung tissue have disclosed appreciable microcirculatory disorders and destruction of the bronchioli and thus promoted the unraveling of the pathogenesis of pulmonary destructive foci.

Preparation of spin-labeled analogs of the antitumor agents TEPA and thio-TEPA

Spin-labeling of phosphorus compounds, cancer, EPR, 2,2,6,6-tetramethylpiperidine-1-oxyl

Chemosterilization of the tropical house mosquito Culex pipiens fatigans Wied.: laboratory and field cage studies

Tris(1-aziridinyl)phosphine sulfide was found to be an excellent sterilant for male Culex pipiens fatigans. When male pupae were exposed to a 0.6% solution for 3 hours, the ensuing adults were rendered permanently sterile with no apparent reduction in their vigour or longevity based on laboratory and field cage studies. Females, however, exposed to the same dosage for the same length of time were partially fertile.