Pharmacokinetics of Anandron in patients with advanced carcinoma of the prostate

Summary The pharmacokinetics of total radioactivity and unchanged drug were studied in patients receiving Anandron (Nilutamide, RU 23908) after a single dose of [¹⁴C] Anandron and after q12 h dosings of unlabelled drug for 2–7 weeks. The results indicate that the radioactivity in plasma consists of unchanged drug and metabolites. The plasma decay of Anandron after the absorption phase was biexponential in all patients, with the terminal phase half-life ranging from 23.3–87.2 h. The plasma decay of total radioactivity after the absorption phase was biexponential in 3/12 and monoexponential in 9/12 patients. The calculated terminal phase half-lives for total radioactivity after [¹⁴C] Anandron were 34.5–137.3 h. The AUC_0– of the unchanged drug in plasma represented 23%–38% of the AUC_0– of total radioactivity. Urinary radioactivity consisted primarily of metabolites, the majority of which were chloroform-nonextractable. Urinary excretion of radioactivity at 120 h ranged from 49%–78% of the administered dose; the unchanged Anandron (at 72 h) was 0.6%–1.3% of the dose. In three patients studied, the fecal excretion of Anandron was 1.4%–7.0%. Steady-state plasma levels (4.4–8.5 g/ml) were attained within approximately 2 weeks from the initiation of twice daily dosing of Anandron. When the plasma pharmacokinetics of radioactivity and unchanged drug after the first single dose were compared with that during steady state, AUC_{0–12 h} of unchanged Anandron during steady state was significantly higher than the AUC_0– after the first single dose, suggesting that the plasma clearance of Anandron is lowered upon chronic administration of the drug, assuming that the bioavailability is constant.     

Microsomal lipid peroxidation induced by Adriamycin,epirubicin, daunorubicin and mitoxantrone: a comparative study

Summary Rat-liver microsomes and NADPH could reduce Adriamycin, epirubicin and daunorubicin to their free radical forms, which enhanced peroxidation of microsomal lipids less than 2-fold in air but 3- to 5-fold at a pO₂ of 4 mm Hg. Mitoxantrone was not reduced by microsomes and had no effect on microsomal peroxidation. Daunorubicin caused more lipid peroxidation than similar concentrations of either Adriamycin or epirubicin, which were equally efficient. In each case peroxidation was iron-dependent and could be catalysed by ferritin. The antioxidants -carotene and -tocopherol inhibited lipid peroxidation at low or high pO₂. The dose-for-dose difference in the cardiotoxicity of epirubicin compared with Adriamycin is not explained by its effect on microsomal lipid peroxidation. However, the lower incidence of cardiotoxicity with mitoxantrone may be a consequence of its inability to form free radical species and promote lipid peroxidation.     

Localization of SNARE proteins and secretory organelle proteins in astrocytes in vitro and in situ

Astrocytes are capable of regulated release of messenger molecules. Astrocytes cultured from new born rodent brain express a variety of classical presynaptic proteins. We investigated the question whether the capability to express synaptic proteins in culture was a feature only of immature astrocytes, and whether these proteins were also expressed by astrocytes in situ. Experiments were performed with transgenic mice expressing the enhanced green fluorescent protein under the control of the human glial fibrillary acidic protein promoter. Using double fluorescence and astrocytes cultured from 1 to 16 day-old animals we show that the astrocytic expression of synaptic proteins in culture is invariant of the age of donor animals. Culturing can induce the astrocytic expression of specific synaptic proteins such as SV2, synaptophysin and SNAP-25. Astrocytes in brain sections of 1-16 day-old animals revealed a punctuate immunofluorescence for secretory carrier membrane protein (SCAMP), SNAP-23, synaptobrevin II, and cellubrevin, to a minor extent for SNAP-25 and synaptophysin, and none for SV2. Our results demonstrate that cultured astrocytes express synaptic proteins not present in situ. Nevertheless, astrocytic organelles in situ are equipped with molecules that could be involved in regulated exocytosis of messenger substances.     

Macrophage response to peripheral nerve injury: the quantitative contribution of resident and hematogenous macrophages

Whereas local microglial cells of the CNS rapidly respond to injury, little is known about the functional role of resident macrophages of the peripheral nervous system in nerve pathology. Using bone marrow chimeric rats, we recently identified individual resident endoneurial macrophages that rapidly became activated after nerve injury. However, the extent of local macrophage activation and its quantitative contribution to the total macrophage response is unknown. We now have created chimeric mice by transplanting bone marrow from green fluorescent protein (GFP)-transgenic mice into irradiated wild-type mice, allowing easy differentiation and quantification of hematogenous and resident endoneurial macrophages. After sciatic nerve crush injury, both GFP(-) and GFP(+) resident macrophages, the latter having undergone physiological turnover from the blood before injury, rapidly underwent morphological alterations and increased in number. Proliferating GFP(-) and GFP(+) resident macrophages were abundant and peaked 3 days after injury. A major lesion-induced influx of hematogenous macrophages with a disproportionate increase of GFP(+) macrophages was not observed until Day 4. Throughout all time points examined, GFP(-) resident macrophages were strikingly frequent, reaching maximum numbers 9.5-fold above baseline. There was also a notable proportion of GFP(-) resident endoneurial macrophages phagocytosing myelin and expressing major histocompatibility complex class II. Our results demonstrate for the first time that the rapid response of resident endoneurial macrophages to nerve injury is quantitatively important and that local macrophages contribute significantly to the total endoneurial macrophage pool during Wallerian degeneration.     

Subsynaptosomal distribution of calcium during aging and 3,4-diaminopyridine treatment

Since previous studies showed that calcium uptake by synaptosomes from rodents declines with aging [30], the subsynaptosomal distribution of calcium was determined with the disruption method of Scott et al. [37]. Calcium uptake by the mitochondrial (digitonin-resistant) and non-mitochondrial (digitonin-labile) compartments, as well as total uptake, were determined at 2, 5 and 10 min. After a 10 min incubation under resting conditions (5 mM-KCl), total calcium uptake decreased at 10 months (−14.6%) and 30 months (−33.0%) of age; mitochondrial calcium uptake increased by 10 months (+11.2%) but declined by 30 months (−17.5%); the nonmitochondrial calcium compartment declined at 10 (−34.7%) and 30 (−43.4%) months when compared to the 3 month old control. With potassium depolarization (31 mM-KCl), total calcium uptake declined from 100% (3 months) to 73.8% (10 months) or 53.0% (30 months); mitochondrial calcium uptake declined from 100% (3 months) to 85.6% (10 months) or 68.4% (30 months); non-mitochondrial calcium uptake decreased at 10 (−34.3%) and 30 (−57.7%) months of age when compared to 3 months (100%). The deficits in calcium homeostasis are not due to changes in synaptosomal volumes or to diminished membrane potentials, as assessed by tetraphenylphosphonium ion accumulation. 3,4-Diaminopyridine partially reversed the alterations in total, mitochondrial and non-mitochondrial calcium uptake by synaptosomes from aged mice.     

Glucose determination in human aqueous humor with Raman spectroscopy

It has been suggested that spectroscopic analysis of the aqueous humor of the eye could be used to indirectly predict blood glucose levels in diabetics noninvasively. We have been investigating this potential using Raman spectroscopy in combination with partial least squares (PLS) analysis. We have determined that glucose at clinically relevant concentrations can be accurately predicted in human aqueous humor in vitro using a PLS model based on artificial aqueous humor. We have further determined that with proper instrument design, the light energy necessary to achieve clinically acceptable prediction of glucose does not damage the retinas of rabbits and can be delivered at powers below internationally acceptable safety limits. Herein we summarize our current results and address our strategies to improve instrument design.     

Detection of Parkin (PARK2) and DJ1 (PARK7) mutations in early-onset Parkinson disease: Parkin mutation frequency depends on ethnic origin of patients

Mutations in the Parkin (PARK2) and the DJ1 (PARK7) gene cause early-onset Parkinson disease (EOPD). We tested 75 Serbian EOPD patients for mutations in both genes by conventional mutational screening (SSCP/dHPLC/sequencing) to detect small sequence alterations and by gene dosage studies (quantitative PCR) to reveal deletions or multiplications of one or more exons. A compound heterozygous Parkin mutation (exon deletion and point mutation; [c.836_972del]+[c.1411C>T]; +1 is first nucleotide of GenBank AB009973.1) was identified in a patient who showed a relatively benign course after a disease onset at 41 years. Another case had a heterozygous exon deletion in DJ1 ([c.253_322del]+[?]) and presented with an age at onset of 45 years and a rapid disease course. In conclusion, Parkin mutations are surprisingly rare in our Serbian EOPD sample, suggesting that the mutation rate depends on the ethnic origin of the patients. Although DJ1 mutations appear to be rare, we confirm their role in EOPD and demonstrate the importance of gene dosage studies.     

Human cytomegalovirus UL144 gene polymorphisms in congenital infections

The human cytomegalovirus (HCMV) UL144 gene is a tumor necrosis factor-like receptor with the potential to affect HCMV virulence. HCMV strains display genetic variability in the UL144 region, and the analysis of a potential link between UL144 gene polymorphisms and disease severity has scarcely been studied. However, a correlation between the UL144 genotype and congenital-disease outcome has been reported in one previous study, with the observation that all asymptomatic infants had a single UL144 genotype. In order to confirm or refute this finding, we determined the UL144 polymorphisms of HCMV strains recovered from the amniotic fluids of 38 infected fetuses and compared them to HCMV strains obtained from 30 viremic adult controls. The UL144 sequences were distributed among five genotypes (A, B, C, AC, and AB), as previously described. We observed similar percentages of the three major genotypes A (37%), B (33%), and C (27%) in our population. The UL144 genotype distributions were similar among the group of infected adults and the group of infected fetuses and among symptomatic and asymptomatic fetuses (P < 0.05). In our series, all five UL144 genotypes could be vertically transmitted from mothers to fetuses, and all could cause symptomatic congenital infection. We concluded that determination of UL144 polymorphisms in cases of congenital infection is not relevant, since it is unlikely to help predict the outcome of the infection.