A phase II study of SB939, a novel pan-histone deacetylase inhibitor, in patients with translocation-associated recurrent/metastatic sarcomas-NCIC-CTG IND 200†.

BACKGROUND: A subgroup of sarcomas is characterized by defining chromosomal translocations, creating fusion transcription factor oncogenes. Resultant fusion oncoproteins associate with chromatin-modifying complexes containing histone deacetylases (HDAC), and lead to epigenetic transcriptional dysregulation. HDAC inhibitors were shown to be effective in vitro, reversing gene repression by these complexes, restoring PTEN expression and apoptosis via the PI3K/Akt/mTOR pathway. PATIENTS AND METHODS: SB939 is an oral inhibitor of classes 1 and 2 HDAC. Eligible patients with recurrent or metastatic translocation-associated sarcoma (TAS) by local pathology were treated with 60 mg/day every other day for 3 of 4 weeks. Central pathology review was conducted with fusion oncogenes characterized, and HDAC2 expression correlated with efficacy in pre-specified methods. RESULTS: Twenty-two patients were treated with a median of 2 cycles. Fourteen patients were assessable for response with confirmed specific chromosomal translocations; 8 had a best response of stable disease (SD) (median duration 5.4 months) with no confirmed objective responses. The 3-month progression-free survival (PFS) rate was 49%. Among those with HDAC2 score ≥5, 7/10 had SD, versus 0/3 with HDAC2 score <5. SB939 was considered as well tolerated with <10% patients experienced ≥grade 3 toxicity. CONCLUSION: This study was stopped prematurely due to prolonged unavailability of SB939. No objective responses were seen. Although the observed SD in HDAC2 high patients was interesting, due to the small sample size, no definitive conclusion can be drawn about the efficacy of SB939 in this patient population. CLINICAL TRIAL: NCT01112384.

Safe handling of cytotoxics: guideline recommendations.

BACKGROUND: This evidence-based practice guideline was developed to update and address new issues in the handling of cytotoxics, including the use of oral cytotoxics; the selection and use of personal protective equipment; and treatment in diverse settings, including the home setting. METHODS: The guideline was developed primarily from an adaptation and endorsement of an existing guideline and from three systematic reviews. Before publication, the guideline underwent a series of peer and external reviews to gather feedback. All comments were addressed, and the guideline was amended when required. The guideline applies to health care workers who could come into contact with cytotoxic drugs at any point in the medication circuit. The intended users are hospital administrators, educators, and managers; occupational health and safety services; and pharmacy and health care workers. RESULTS: The recommendations represent a reasonable and practical set of procedures that the intended users of this guideline should implement to minimize opportunities for accidental exposure. They are not limited to just the point of care; they cover the entire chain of cytotoxics handling from the time such agents enter the institution until they leave in the patient or as waste. CONCLUSIONS: Reducing the likelihood of accidental exposure to cytotoxic agents within the medication circuit is the main objective of this evidenced-based guideline. The recommendations differ slightly from earlier guidelines because of the availability of new evidence.

Male sexual dysfunction in mice bearing targeted mutant alleles of the PEA3 ets gene.

PEA3, a member of the Ets family of transcriptional regulatory proteins, is expressed in a unique spatial and temporal pattern during mouse embryogenesis; its overexpression is positively correlated with HER2-mediated breast tumorigenesis in both humans and mice. To determine whether PEA3 plays a part in development and oncogenesis and to uncover its normal physiological role, we generated mice lacking functional PEA3 by gene targeting in embryonic stem cells. PEA3(-/-) mice arose from heterozygous crosses with the expected Mendelian frequency, revealing that PEA3 is dispensable for embryogenesis. PEA3 mutant mice displayed no overt phenotype and lived a normal life span. However, PEA3-deficient males failed to reproduce. PEA3 is expressed in several male sexual organs, but gross and histological analyses of the organs from PEA3(-/-) mice revealed no abnormalities. Spermatogenesis and spermiogenesis also appeared normal in mice homozygous for the PEA3 mutation, and their sperm were capable of fertilizing eggs in vitro. PEA3(-/-) males engaged in normal mating behavior, but they did not set copulatory plugs and sperm could not be detected in the uteri of females that had mated with PEA3(-/-) males. Erections could be evoked by abdominal pressure in PEA3-deficient male mice, and the results of in vitro experiments revealed that the corpus cavernosum isolated from PEA3 mutant males relaxed in response to acetylcholine. Therefore, the infertility of PEA3 mutant males involves either mechanisms proximal to the cavernosal smooth muscle or an ejaculatory dysfunction. However, PEA3 mutant mice are phenotypically distinguishable from other knockout mice with such deficits and thus provide a unique model for further investigation of male sexual dysfunction.

The activity of the Ets transcription factor PEA3 is regulated by two distinct MAPK cascades.

PEA3, a member of the Ets family of transcriptional regulatory proteins, binds to the PEA3 promoter element and stimulates transcription through this site. The activity of the PEA3 element is regulated by mitogens, activated receptor tyrosine kinases, and oncogenic members of the Ras signal transduction pathway. However, it is not clear whether PEA3 mediates transcriptional regulation by these agents because a number of different Ets proteins can functionally interact with the PEA3 element. To specifically learn whether the activity of PEA3 is regulated, we investigated the ability of constitutively-activated Ras (Ha-RasV12) and signaling proteins downstream of Ras to alter PEA3-dependent reporter gene expression in COS cells. Ha-RasV12 and activated proteins in both the extra-cellular regulated kinase (ERK) and the stress-activated protein kinase (SAPK) or Jun N-terminal kinase (JNK) cascades independently stimulated PEA3-mediated gene expression. Ha-RasV12 stimulation of PEA3 activity was reduced by dominant-negative mutants in each of these protein kinase cascades, suggesting that Ras activates PEA3 through both pathways. Furthermore, the ability of unique activators of each kinase cascade to stimulate PEA3-dependent gene expression was selectively reduced by dominant-negative mutants within the homologous but not the heterologous pathway. Hence two distinct mitogen-activated protein kinase (MAPK) cascades regulate PEA3 activity. PEA3 was phosphorylated in vivo at serine residues consistent with the possibility that it may be a direct target of MAPKs.

The arotinoids: early clinical experience and discussion of future development.

There has been great interest in the use of drugs attempting to modify the properties of malignant cells without necessarily destroying them. The family of compounds known as the retinoids have shown particular promise in this area. Current interest is directed towards established retinoids such as ATRA and 13-CRA. Newer synthetic retinoids such as fenretinide, the arotinoid Ro 40-8757, and 9-cis retinoic acid have been entering clinical trials. Ro 40-8757 is a particularly interesting new arotinoid with properties quite distinct from the other retinoids. It has different binding proteins and appears to regulate different genes than the classical retinoids such as ATRA or 13-CRA. Furthermore, it appears active against a different spectrum of malignancies. It also appears to have a relatively favourable side-effect profile. In addition to its anti-proliferative effects, this arotinoid may play a role in protection of bone marrow function after use of cytotoxic drugs. Development of Ro 40-8757 was halted before the compound had entered phase II testing due to lack of resources. Future developmental programmes for retinoids should move rapidly to explore the potential of interesting combinations identified in preclinical models. Retinoids should be considered primarily as drugs which modulate and enhance the effects of other active anticancer agents. Their development should not be prevented because they are unlikely to be active as single agents against common solid tumours.

The arotinoids: early clinical experience and discussion of future development.

There has been great interest in the use of drugs attempting to modify the properties of malignant cells without necessarily destroying them. The family of compounds known as the retinoids have shown particular promise in this area. Current interest is directed towards established retinoids such as ATRA and 13-CRA. Newer synthetic retinoids such as fenretinide, the arotinoid Ro 40-8757, and 9-cis retinoic acid have been entering clinical trials. Ro 40-8757 is a particularly interesting new arotinoid with properties quite distinct from the other retinoids. It has different binding proteins and appears to regulate different genes than the classical retinoids such as ATRA or 13-CRA. Furthermore, it appears active against a different spectrum of malignancies. It also appears to have a relatively favourable side-effect profile. In addition to its anti-proliferative effects, this arotinoid may play a role in protection of bone marrow function after use of cytotoxic drugs. Development of Ro 40-8757 was halted before the compound had entered phase II testing due to lack of resources. Future developmental programmes for retinoids should move rapidly to explore the potential of interesting combinations identified in preclinical models. Retinoids should be considered primarily as drugs which modulate and enhance the effects of other active anticancer agents. Their development should not be prevented because they are unlikely to be active as single agents against common solid tumours.

Immunolocalization of matrix metalloproteinases and their inhibitors in clinical specimens of bone metastasis from breast carcinoma.

Matrix metalloproteinases (MMPs) are essential in several stages of the metastatic process, and in normal bone development and remodeling. We explored whether the interaction between tumor cells and bone leads to changes in MMP and tissue inhibitor of MMP (TIMP) expression thus affecting osteolysis in metastatic bone disease. Using immunohistochemistry we have investigated the MMP/TIMP expression in tumor cells, fibroblasts, osteoblasts and osteoclasts. Thirty one specimens of bone metastasis from breast carcinoma were stained for MMP-1, -2, -9, MT1-MMP and TIMP-1, and -2 and compared with staining in normal breast tissue, primary breast carcinoma and normal bone. Specimens came from patients in three clinical scenarios: from open biopsies without or with pathological fracture, or bone marrow biopsies containing tumor from patients with pancytopenia but without clinical evidence of osteolysis. By bone histomorphometry the latter group showed a heavy tumor load not different from the open biopsy groups but displayed little active bone resorption and low numbers of osteoclasts. Cell type-specific MMP/TIMP expression was observed and the staining patterns were comparable between the three groups of patients. Though no major differences in the MMP/TIMP staining of tumor cells and fibroblasts were observed between bone metastasis and primary tumor, we showed that tumor cells do express MMPs capable of degrading bone matrix collagen. The number and activity of osteoclasts and osteoblasts was increased dramatically in bone metastases, their MMP/TIMP profiles, however, were not different from normal bone, suggesting that the mechanism of bone degradation by osteoclasts is not different from normal bone remodelling.

Genetically modified dendritic cells in cancer therapy: implications for transfusion medicine.

Dendritic cells (DCs) are a heterogeneous population of antigen-presenting cells (APCs) identified in various tissues, including the skin (Langerhans cells), lymph nodes (interdigitating and follicular DCs), spleen, and thymus. Properties of DCs include the ability to (1) capture, process, and present foreign antigens; (2) migrate to lymphoid-rich tissue; and (3) stimulate innate and adaptive antigen-specific immune responses. Until recently, the ability to study DCs has been limited by their absence in most culture systems. It is now known that specific cytokines can be used to expand DCs to numbers sufficient for their in vitro evaluation and for their use in human immunotherapy trials. Human DCs can be derived from hematopoietic progenitors (CD34+-derived DCs) or from adherent peripheral blood monocytes (monocyte-derived DCs). Cultured DCs can be recognized by a typical veiled morphologic appearance and expression of surface markers that include major histocompatibility complex class II, CD86/B7.2, CD80/B7.1, CD83, and CD1a. DCs are susceptible to a variety of gene transfer protocols, which can be used to enhance biological function in vivo. Transduction of DCs with genes for defined tumor antigens results in sustained protein expression and presentation of multiple tumor peptides to host T cells. Alternatively, DCs may be transduced with genes for chemokines or immunostimulatory cytokines. Although the combination of ex vivo DC expansion and gene transfer is relatively new, preliminary studies suggest that injection of genetically modified autologous DCs may be capable of generating anti-tumor immune responses in patients with cancer. Preclinical animal studies showing potent antigen-specific tumor immunity after DC-based vaccination support this hypothesis and provide rationale to further evaluate this approach in patients. Preliminary human studies are now required to evaluate optimal DC dose, schedule of vaccination, route of delivery, and maturational state of cultured cells. Initiation of these phase I/II cell therapy-based studies will occur in collaboration with hospital-based transfusion facilities. Issues relating to cell harvesting, storage, culture methodology, and administration require the collaborative efforts of basic scientists, immunologists, clinical investigators, and transfusion medicine staff to ensure strict quality control of injected cellular products. This review is intended to provide a brief overview of clinical DC-based gene transfer.

Effect of dilution on the growth of bacteria from blood cultures.

Artificial blood culture systems were set up to find the dilution with medium necessary to overcome the natural antibacterial effect of blood. The results indicate that blood should be diluted at least 1 in 50 in medium unless an additive such as Liquoid is used.

Intra-uterine closure of the atrial septum.

Two newborn babies with an intact atrial septum are described. In one, the two components of the atrial septum appeared to have become fused after relatively normal initial development; the left side of this heart was hypoplastic. In the other baby the formation of the atrial septum appeared to have been completely anomalous; this heart showed mitral atresia, absence of the left ventricle, and transposition of the great vessels. There was also pulmonary lymphangiectasis in the second case, and it is suggested that this was due to the cardiac malformation obstructing pulmonary venous drainage.

Unusual presentation of patients with myelomatosis in Malawi.

Malignant myeloma is not rare in tropical Africa. Its mode of presentation in Malawi is most often that of a tumour mass in bone. The types of immunoglobulin heavy and light chains in the tumour cells occur with a frequency similar to that observed in temperate countries.

Comparison of the time course of the anorectic effect of fenfluramine and amphetamine with drug levels in blood.

Time courses of the suppressive effects on food intake of (+)-amphetamine and (plus or minus)-fenfluramine in deprived rats were found to be different. Amphetamine displayed a potent initial action which rapidly decayed, and this behavioural effect was consistent with the measured blood concentration of amphetamine which showed a peak at 1 h followed by rapid clearance. For fenfluramine, the initial suppression of eating was maintained over several hours and was, for the first hour, related to the blood concentration of fenfluramine but later to an active metabolite, norfenfluramine. The study shows how drug-induced changes in feeding behaviour fluctuate over time and illustrate how single measures of food intake may overlook information about the effectiveness of anorectic drugs.

Impedance imaging using induced currents.

The principal features of an electrical impedance tomography system using induced currents are described. Images of the distribution of conductivity in a two-dimensional phantom are obtained using an algorithm based on a sensitivity matrix. Results are also presented which demonstrate the separation of conductivity and permittivity images from measurements of the complex peripheral voltage, the formation of unreferenced permittivity images, and the use of capacitively coupled electrodes in a measuring system without direct electrical contact.

Antiepileptic drugs, hepatic enzyme induction and raised serum alkaline phosphatase isoenzymes.

Thirteen patients with epilepsy on long-term antiepileptic drug therapy and who had a persistently raised serum alkaline phosphatase (ALP) activity were investigated biochemically. Twelve patients had a raised liver ALP-isoenzyme activity and in nine of these the bone ALP-isoenzyme activity was normal. Gamma-glutamyl transferase (gamma GT) levels were raised in 12 patients. Two patients were hypoglycaemic. One patient fitted the biochemical parameters for subclinical osteomalacia. The resultant clinical picture showed 75% of patients with borderline hypocalcaemia, raised liver ALP, raised gamma GT and normal bone ALP activities in whom 1,25 dihydroxy-cholecalciferol (1,25-DHCC; vitamin D) therapy would be inappropriate, whilst 1,25-DHCC therapy might be considered for those with borderline hypocalcaemia and a raised bone ALP activity (three patients). No evidence was found of hepatotoxicity or drug induced cholestasis. It is considered that the induction of liver microsomal enzymes by antiepileptic drugs could include liver ALP (as opposed to bone ALP) as well as gamma GT and the inactivation pathways for 1,25 DHCC.

Control of horn fly (Diptera: Muscidae) in Florida with an Australian trap.

A newly developed Haematobia spp. trap is described, and results are presented from field trials to reduce populations of adult horn fly, Haematobia irritans L., on 5 dairy farms in western Florida and Alabama during the summer of 1992. We compared fly infestations on milkers subjected to trapping, versus either dry cattle on the same farm or milkers on a nearby farm, without the trap but where traditional horn fly control practices were used. Results gave 96.9% (95% CI, 93.8-98.4) reduction compared with dry cattle with a mean count of 228 per animal, and 90.2% (84.5-94.5%) compared with milkers on the control farms with a mean count of 113. Trapping removed the need to use insecticides to control this pest on milking dairy cattle and so offers a practical, environmentally acceptable, safe, and sustainable means of horn fly control on cattle which pass through the trap regularly.

The efficacy of diazinon impregnated ear tags against buffalo fly and resulting weight gains and diazinon residues in meat and milk.

Ear tags impregnated with 20% diazinon were evaluated for their efficacy against the buffalo fly (Haematobia irritans exigua) on beef cattle in southern Queensland. Buffalo fly numbers and weight changes were recorded and diazinon residues in tissues of beef cattle and milk from lactating dairy cattle were assayed at different time intervals after tagging. In 2-efficacy trials conducted over 19 and 20 weeks, the mean numbers of buffalo fly on cattle each fitted with ear tags were 1 to 9 and 0 to 16, respectively, in trials 1 and 2, compared with 44 to 345 and 26 to 306 per head on untreated herds, respectively, despite regular spraying of the untreated herd in trial 1 with cypermethrin to reduce fly burdens. Percentage buffalo fly control was 96.7 to 99.5% and 89.3 to 100% in the 2 trials. Cattle fitted with ear tags gained an average of 94 kg body weight after 5 months compared with 61 kg in the untreated herd, a net increase of 60% in treated animals compared with 28% in the untreated herd. Mean diazinon residue concentrations in the fat of perianal tissue biopsies were 0.02 to 0.03 mg/kg 1 to 8 weeks after tagging. Mean diazinon residue concentrations in the butterfat of milk from lactating dairy cattle were 0.01 to 0.04 mg/kg after tagging.

The efficacy of ivermectin against larvae of the screw-worm fly (Chrysomya bezziana).

An in vitro technique for screening systemic insecticides against larvae of the screw-worm fly, Chrysomya bezziana is described. Susceptibilities of screw-worm larvae of different ages to ivermectin (MK-933) were determined. Based on 24 h larval mortality, the LD50 of 1-,2-,3-,4- and 5-day larvae was 0.01, 0.02, 0.03, 0.2 and 0.4 ppm of ivermectin. LD50 based on adult emergence following treatment of 4- and 5-day larvae was 0.02 and 0.05 ppm. The LD99.9 for 4-day larvae based on 24 h larval mortality and adult emergence was 11.0 and 0.15 ppm respectively and for 5-day larvae, was 44.3 and 0.4 ppm respectively. Pen and field trials with cattle infested with screw-worm fly demonstrated the potential of ivermectin as a systemic insecticide. Dosages of 50, 100 and 200 micrograms/kg, of ivermectin administered subcutaneously to experimentally infested cattle gave complete control for 6, 12 and 14 days respectively. Ivermectin at 200 micrograms/kg caused 100% mortality of screw-worm larvae up to 2 days old at the time of treatment with 70, 64 and 21% mortality of 3-, 4- and 5-day old larvae at the time of treatment. The residual protection from a single dose of 200 micrograms/kg was 16 to 20 days. When bull calves were treated with ivermectin at a dose of 200 micrograms/kg at the time of castration and branding, none of the 77 treated animals sustained a screw-worm strike in the scrotal area compared with 47 strikes (44%) in the 106 control cattle.

The efficacy of insecticides against the screw-worm fly (Chrysomya bezziana).

A number of insecticides used for ectoparasite control in the livestock industry were screened for their efficacy against larvae of the screw-worm fly, Chrysomya bezziana, using in vivo and laboratory tests. Proprietary screw-worm fly treatments (after exposure to outdoor conditions for up to 10 days) were also tested against eggs and adults of C bezziana. Three of these were also evaluated on naturally acquired screw-worm infestations. Residual protection was generally of short duration. Among the organophosphorus compounds, the most effective formulations contained relatively high concentrations (3 to 4% al) of coumaphos, 2.5% fenchlorphos or low concentrations (0.05 to 0.5% al) of diazinon, chlorfenvinphos and fenthion methyl. Two chlorinated hydrocarbon insecticides containing 3% lindane and 5% dieldrin were very effective but are now prohibited for use in Australia. Preparations had serious deficiencies when used under field conditions, especially for treating large, deepseated myiases for which systemic insecticides are recommended. A comparison of methods demonstrated that a laboratory test could supersede live animal experimentation, at least for the initial screening of potential insecticides.

The efficacy of some acaricides against screw-worm fly larvae.

Thirteen acaricides used for control of cattle tick in Queensland were evaluated for their potential in the chemical control of the screw-worm fly, Chrysomya bezziana. Laboratory evaluations and in vivo tests using artificially infested cattle were made in Papua New Guinea. Most of the acaricides caused some mortality of screw-worm larvae in infested cattle and in laboratory tests. Acaricides of the organophosphorous, carbamate and organophosphorous/synthetic pyrethroid groups showed reasonable activity against screw-worm fly, but the amidines were less effective.

Papua New Guinea Red Cross Blood Transfusion Service: present status and future considerations.

About 28,000 units of blood are collected per annum. This is adequate for present needs. 11 donors have been found positive for human immunodeficiency virus (HIV) since testing started in 1987, 8 of these in the last year and a half. No case of transmission of HIV by transfusion in Papua New Guinea has been established. Although the prevalence varies in different areas, on average 15% of donors are positive for hepatitis B. The impact of these figures, future requirements for quantity of blood and the need for additional testing of donations for hepatitis C (HCV) and cytomegalovirus (CMV) will require clear evaluation of the choices and firm decisions.

PIP: The Papua New Guinea Red Cross Blood Transfusion Program, a nongovernmental organization based in Port Moresby General Hospital, has an agreement with the government to "recruit and maintain suitable donor panels and collect and store blood at appropriate centers." The government provides staff (except for the Director and Deputy Director), buildings, and equipment. About 28,000 units of blood are collected each year from unpaid donors at government and church hospitals and mobile sites. Almost 50% of donors are new donors. Generally, the demand for blood is met. Donations are tested for hepatitis B and HIV. Since screening commenced in 1987, 11 donors have been found to be HIV-infected. No case of HIV transmission by transfusion has been established. On average, 15% of donors are positive for hepatitis B. Future goals include consolidation of a stable group of donors who give blood repeatedly and reliably and evaluation of the need for screening of blood supplies for hepatitis C and cytomegalovirus infections. The total annual cost of the blood transfusion program is about K200,000.