DNA-directed alkylating agents. 3. Structure-activity relationships for acridine-linked aniline mustards: consequences of varying the length of the linker chain

Four series of acridine-linked aniline mustards have been prepared and evaluated for in vitro cytotoxicity, in vivo antitumor activity, and DNA cross-linking ability. The anilines were attached to the DNA-intercalating acridine chromophores by link groups (-O-, -CH2-, -S-, and -SO2-) of widely varying electronic properties, providing four series of widely differing mustard reactivity where the alkyl chain linking the acridine and mustard moieties was varied from two to five carbons. Relationships were sought between chain length and biological properties. Within each series, increasing the chain length did not alter the reactivity of the alkylating moiety but did appear to position it differently on the DNA, since cross-linking ability (measured by agarose gel assay) altered with chain length, being maximal with the C4 analogue. The in vivo antitumor activities of the compounds depended to some extent on the reactivity of the mustard, with the least reactive SO2 compounds being inactive. However, DNA-targeting did appear to allow the use of less reactive mustards, since the S-linked acridine mustards showed significant activity whereas the parent S-mustard did not. Within each active series, the most active compound was the C4 homologue, suggesting some relationship between activity and extent of DNA alkylation.     

The rate of development and time of transfer play different roles in influencing the viability of human blastocysts

Improved embryo culture protocols now render more feasible the possibility of obtaining human blastocysts after in-vitro fertilization. In this study we present: (i) results of blastocyst development from supernumerary embryos after co-culture on green monkey kidney epithelial cells and (ii) pregnancy rates after transfer of frozen blastocysts. In addition, we have examined the influence of the day of blastocyst freezing and the day of transfer after the luteinizing hormone (LH) peak on pregnancy and implantation rates. Of 423 supernumerary embryos, 200 developed to the blastocyst stage (47.3%). By days 5 and 6, 67% of the blastocysts had reached the blastocyst stage, and were frozen, compared to 28.5% by day 7. When we compared the cases where only blastocysts frozen on days 5 and 6 were transferred compared to those frozen and transferred on or after day 7 the pregnancy rates were 7/18 (38.9%) and 1/16 (6.2%) respectively. In contrast, when we examined the influence of the day of transfer we found that pregnancies were established from day 5 up to day 9 post LH peak. Based on these results, we suggest that every attempt should be made to increase the development rate of supernumerary embryos to the blastocyst stage, as it appears that the quality of blastocysts transferred, as shown in this study by rate of development, plays a more crucial role than the timing of transfer.      

Changes in muscle morphology in dialysis patients after 6 months of aerobic exercise training.

BACKGROUND: In the present study we investigated the effect of a 6-month aerobic exercise programme on the morphology of the gastrocnemius muscle of end-stage renal disease (ESRD) patients. METHODS: Twenty-four ESRD patients volunteered to participate in the training programme and underwent muscle biopsy before training. Eighteen patients completed the training programme of whom nine agreed to a post-training biopsy (one woman and eight men, mean age 56 +/- 15 years). Data are presented for the nine subjects who were biopsied before (PRE) and after training (POST) and separately for the 15 subjects for whom we only have a biopsy before training (cross-sectional group). RESULTS: There were no significant differences (P > 0.05) in fibre type distribution or myosin heavy chain (MyHC) expression between the cross-sectional and PRE/POST groups. The mean cross-section fibre area after training (POST) increased by 46% compared with the PRE training status (P < 0.01). The proportion of atrophic fibres decreased significantly after training in type I, IIa and IIx fibre populations (from 51 to 15%, 58 to 21% and 62 to 32%, respectively). Significant differences were also found in capillary contact per fibre (CC/F), with the muscle having 24% (P < 0.05) more CC/F compared with the PRE training status. No significant differences in cytochrome c oxidase concentration were found between the groups. CONCLUSIONS: In conclusion, exercise appeared to be beneficial in renal rehabilitation by correcting the fibre atrophy, increasing the cross-section fibre area and improving the capillarization in the skeletal muscle of renal failure patients.     

The fate of N1'-methanesulphonyl-N4'-(9-acridinyl)-3'-methoxy-2',5'-cyclohexadiene- 1',4'-diimine (m-AQDI), the primary oxidative metabolite of amsacrine, in transformed Chinese hamster fibroblasts

The cytotoxicity of the anti-leukaemia drug amsacrine (m-AMSA) has been suggested to result from its oxidative metabolism to the corresponding quinonediimine, N1'-methanesulphonyl-N4'-(9-acridinyl)-3'-methoxy-2',5'-cyclohexad iene-1',4'- diimine (mAQDI). The metabolic fate of mAQDI was examined in cultured CHO cells (subline AA8) to identify the end products to be expected following oxidative metabolism of m-AMSA. [Acridinyl-G-3H]-m-AQDI was rapidly accumulated by AA8 cells in phosphate buffered saline with complete conversion in less than one minute to m-AMSA, macromolecular adducts and polar low molecular weight species, each of these three classes being formed in approximately equal amounts. Two of the polar products were chromatographically identical to those formed on reaction of m-AQDI with reduced glutathione. These were identified by 1H NMR spectroscopy as the 1,4-addition product 5'-(S-glutathionyl)-m-AMSA and the previously unreported isomeric 6'-(S-glutathionyl)-m-AMSA. These thiol adducts were also formed rapidly from m-AQDI in deproteinized cell lysates indicating a non-enzymatic process, although the possibility of enzymatic catalysis in intact cells has not been eliminated. The absence of such products in AA8 cells after treatment with m-AMSA places an upper limit of 1% per hour on the rate of its oxidative metabolism in these cells and suggests that generation of m-AQDI is unlikely to be responsible for the cytotoxicity of m-AMSA in cultured tumour cells.     

Conducting applied research on Vietnam combat-related post-traumatic stress disorder

A paradigmatic shift in post-traumatic stress disorder (PTSD) research is underway. Formistic and mechanistic research designs, characterized by single-category, single-cause, single-effect models, gradually are being replaced by contextual and organistic research designs that feature multi-category, multi-cause, and multi-effect interactional models. Such changes in diagnostic and treatment outcome research require solving many methodological issues in such areas as: measuring types of traumas and stressors; measuring PTSD symptoms and subtypes; measuring subject dispositional characteristics (such as ethnic differences); assessing concurrent and/or pre-existing psychiatric (Axis I) disorders; classifying personality styles and concurrent and/or pre-existing personality (Axis II) disorders; evaluating phase in the development of PTSD as a disorder; measuring current environmental stresses and interpersonal interactions; and assessing secondary gains and readiness for treatment. These and other methodological problems must be addressed as research on PTSD shifts to longitudinal measurement of subjects randomly assigned to treatment conditions.     

NLA-1: a 2-nitroimidazole radiosensitizer targeted to DNA by intercalation.

Targeting of electron affinic radiosensitizers to DNA via reversible non-covalent intercalative binding has potential for increasing sensitizer concentrations locally at the DNA target while decreasing accessibility to reductases responsible for bioactivation and cytotoxicity. We have prepared an DNA-targeted acridine-linked 2-nitroimidazole (NLA-1) as an example of such a compound. NLA-1 binds reversibly to DNA with an affinity similar to 9-aminoacridine, and is approximately 1000 times more potent than MISO as a cytotoxin, despite a similar reduction potential. It shows less enhancement of cytotoxicity under hypoxia (5- to 6-fold) than does MISO (approximately 11-fold), but is a potent hypoxia-selective radiosensitizer in AA8 cells with a concentration for an enhancement ratio of 1.6 (C1.6) of 9 microM. The mean intracellular concentration at the C1.6 is 400 microM, on which basis its potency is about twice that of MISO. The in vitro therapeutic index (aerobic cytotoxic potency/hypoxic C1.6) of NLA-1 is approximately 6-fold lower than that for MISO. NLA-1 lacks radiosensitizing activity against SCCVII or EMT6 tumors in vivo at the maximum tolerated dose (MTD) of 100 mumol.kg-1.     

Diagnostic value of anti-cyclic citrullinated peptide antibodies in Greek patients with rheumatoid arthritis

Background  

Anti-cyclic citrullinated peptide (anti-CCP) antibodies have been of diagnostic value in Northern European Caucasian patients with rheumatoid arthritis (RA). In these populations, anti-CCP antibodies are associated with the HLA-DRB1 shared epitope. We assessed the diagnostic value of anti-CCP antibodies in Greek patients with RA where the HLA shared epitope was reported in a minority of patients.     

Blastocyst development from supernumerary embryos after intracytoplasmic sperm injection: a paternal influence?

The success of intracytoplasmic sperm injection (ICSI) warrants further study on the role of paternal factors in early human embryogenesis. To investigate whether poor sperm parameters can influence embryo development, we examined the development of ICSI-fertilized embryos to the blastocyst stage. We present results of blastocyst development from supernumerary ICSI embryos after co-culture on monkey kidney epithelial cells. In addition, we compare the development of supernumerary embryos to the blastocyst stage after ICSI and in-vitro fertilization (IVF). Of 168 supernumerary ICSI embryos, 45 (26.8%) developed to blastocysts. Sperm concentration and morphology did not influence blastocyst development. In contrast, blastocysts arose from spermatozoa that had a significantly higher (P = 0.015) forward progressive motility compared with spermatozoa from those patients who failed to produce blastocysts (42.7% versus 28.2%, respectively). Overall the rate of embryo development to the blastocyst stage after ICSI was lower (26.8%) than that after IVF (47.3%). When the rate of blastocyst development was calculated for patients with three or more supernumerary embryos, it remained significantly higher for the IVF patients than for the ICSI patients (45.6% versus 30.0%). There was no significant difference in the mean cell number and quality of the supernumerary embryos between the IVF and ICSI patients. This study confirms previous reports that have postulated that abnormal spermatozoa may manifest a negative paternal effect on preimplantation embryo development.      

Percutaneous isolated liver perfusion for treatment of hepatic malignancy: preliminary report.

Chemotherapy for primary or metastatic hepatic malignancy is limited by poor tumor response and dose-related systemic toxicity. As an alternative to chemotherapy infusion by vein or by the hepatic artery, the authors have developed a percutaneous technique of isolated liver perfusion that allows the regional delivery of high-dose chemotherapy to the liver with little systemic toxicity. After placement of a hepatic artery infusion catheter, an 18-F double-balloon catheter is placed into the inferior vena cava through the opposite femoral vein. Balloons are inflated above and below the hepatic veins, thus isolating hepatic venous outflow. The effluent passes through fenestrations in the catheter and is pumped through charcoal hemoperfusion filters where the drug is removed. The filtered blood is returned to the patient through the internal jugular vein. Fifteen treatments have been conducted in eight patients in a phase I dose-escalation study with use of 5-fluorouracil (5-FU). While it is premature to assess tumor response to isolated liver perfusion, the data demonstrate that the procedure is safe and is tolerated by patients. Pharmacokinetic studies show a 5-FU extraction of up to 85%, with minimal drug leakage into the systemic circulation. This technique shows potential for improving liver tumor response while decreasing systemic toxicity.