Genotype-phenotype relationship in human ATP6i-dependent autosomal recessive osteopetrosis

Autosomal-recessive osteopetrosis is a severe genetic disease caused by osteoclast failure. Approximately 50% of the patients harbor mutations of the ATP6i gene, encoding for the osteoclast-specific a3 subunit of V-ATPase. We found inactivating ATP6i mutations in four patients, and three of these were novel. Patients shared macrocephaly, growth retardation and optic nerve alteration, osteosclerotic and endobone patterns, and high alkaline phosphatase and parathyroid hormone levels. Bone biopsies revealed primary spongiosa lined with active osteoblasts and high numbers of tartrate-resistant acid phosphatase (TRAP)-positive, a3 subunit-negative, morphologically unremarkable osteoclasts, some of which located in shallow Howship lacunae. Scarce hematopoietic cells and abundant fibrous tissue containing TRAP-positive putative osteoclast precursors were noted. In vitro osteoclasts were a3-negative, morphologically normal, with prominent clear zones and actin rings, and TRAP activity more elevated than in control patients. Podosomes, alphaVbeta3 receptor, c-Src, and PYK2 were unremarkable. Consistent with the finding in the bone biopsies, these cells excavated pits faintly stained with toluidine blue, indicating inefficient bone resorption. Bone marrow transplantation was successful in all patients, and posttransplant osteoclasts showed rescue of a3 subunit immunoreactivity.     

Lenalidomide plus dexamethasone vs. lenalidomide plus melphalan and prednisone: a retrospective study in newly diagnosed elderly myeloma

Background: The goal of this retrospective study was to compare the efficacy and toxicity of lenalidomide–dexamethasone (len/dex) vs. melphalan–prednisone–lenalidomide (MPR) as upfront therapy for newly diagnosed elderly patients with myeloma. Methods: Data from 51 patients enrolled in an Italian phase I/II trial and treated with MPR were analyzed and compared with data from 38 patients, seen at the Mayo Clinic, treated with len/dex and enrolled in phase II/III trials. Results: On intention‐to‐treat analysis, time to progression (median: 24.7 vs. 27.5 months in MPR and len/dex groups, respectively, P = 0.903), progression‐free survival (median: 24.7 vs. 27.5 months in MPR and len/dex groups, respectively, P = 0.926), and overall survival (2‐yr overall survival: 86.2% in MPR vs. 89.1% in len/dex, P = 0.730) were not significantly different between the two groups. Results were confirmed when the analysis was restricted to MPR and len/dex matched pair mates. Hematologic grade 3–4 toxicities were more common with MPR (neutropenia: 66.7% vs. 21.1%, P < 0.001; thrombocytopenia: 31.4% vs. 2.6%, P < 0.001). Grade 3–4 gastrointestinal events (13.2% vs. 3.9%, P = 0.132), thrombotic events (13.2% vs. 5.9%, P = 0.279), and fatigue (10.5% vs. 3.9%, P = 0.395) were more common with len/dex. Conclusions: Results show that both MPR and len/dex are efficacious regimens for elderly patients with myeloma. Randomized trials are needed to confirm these results.     

Isoprostanes quickly normalize after quitting cigarette smoking in healthy adults

BACKGROUND: Isoprostanes and in particular 8-epi-PGF2 alpha have been claimed as a useful measure for invivo oxidation injury. While smokers show elevated 8-epi-PGF2 alpha the behaviour during quitting smoking is unknown. METHODS AND RESULTS: We determined 8-epi-PGF2 alpha in 7 healthy adults ready to quit smoking in plasma, serum and urine by means of an enzyme immunoassay after extraction and purification before quitting smoking and during a follow-up period of 4 weeks. After quitting smoking, 8-epi-PGF2 alpha shows a rapid decline within a few days almost completely normalizing within 4 weeks. CONCLUSION: The cigarette-smoking associated invivo oxidation injury almost completely disappears within 4 weeks of quitting smoking.     

Synthesis of (+)- and (-)-cis-2-[(1-adamantylamino)-methyl]-1-phenylcyclopropane derivatives as high affinity probes for sigma1 and sigma2 binding sites

Selective ligands for either sigma1 (sigma1) or sigma2 binding sites are potentially useful for gaining a better understanding of the physiological functions of these proteins. Moreover, potent and selective homochiral sigma1 and sigma2 binding site ligands represent leads to potential radioligands for tumour imaging with positron emission tomography (PET). On the basis of their structural similarity to previous leads, new (+)- and (-)-cis-2-[(1-adamantylamino)-methyl]-1-phenylcyclopropane derivatives were synthesised and their binding affinities for sigma1 and sigma2 binding sites were determined. Each enantiomer showed high affinity for both sigma1 and sigma2 binding sites, but only (-)-cis-methyl-2-[[1-adamantyl(methyl)amino]methyl]-1-phenylcyclopropane-carboxylate, (-)-4, showed appreciable selectivity for binding to sigma1 versus sigma2 sites. The enantiomers of cis-(2-[[1-adamantyl(methyl)amino]methyl]-1-phenylcyclopropyl)methanol, 6, expressed the highest affinity for sigma1 and sigma2 binding sites. Ligands (-)-4, (+)-6 and (-)-6 might be rapidly labelled in their N-methyl groups by methylation of the N-desmethyl analogues with [11C]iodomethane to provide prospective radioligands for PET. The N-desmethyl analogues, which are also high affinity ligands, were prepared and shown to undergo satisfactory methylation with iodomethane.     

Antitumor agents. 1. Synthesis,biological evaluation,and molecular modeling of 5H-pyrido[3,2-a]phenoxazin-5-one,a compound with potent antiproliferative activity

The iminoquinone is an important moiety of a large number of antineoplastic drugs and plays a significant role in the nucleus of actinomycins, powerful, highly toxic, natural antibiotics that target DNA as intercalating agents. A series of polycyclic iminoquinonic compounds, 2-amino-3H-phenoxazin-3-one (1), 2-amino-1,9-diacetyl-3H-phenoxazin-3-one (2), 2-acetylamino-3H-phenoxazin-3-one (3), 3H-phenoxazin-3-one (4), 5H-pyrido[3,2-a]phenoxazin-5-one (5), and 5H-pyrido[3,2-a]phenothiazin-5-one (6), strictly related to the actinomycin chromophore, were synthesized for developing new anticancer intercalating drugs. The antiproliferative activity of these compounds, evaluated against representative human liquid and solid neoplastic cell lines, showed that 5 and its isoster 6 were the most active compounds inhibiting cell proliferation in a submicromolar range. Compound 5 was also evaluated against KB subclones (KBMDR, KB7D, and KBV20C), which overexpress the MDR1/P-glycoprotein drug efflux pump responsible for drug resistance. All the above KB subclones did not show altered sensitivity to the antiproliferative activity of 5. UV-vis and (1)H NMR spectroscopy experiments support the phenoxazinone 5/DNA binding. Molecular mechanics methods were used to build a three-dimensional model of the 5/[d(GAAGCTTC)]2 complex. Electrostatic interactions between the hydrogen of the positively charged pyridine nitrogen of 5 and the negatively charged oxygen atoms (O4' and O5') of the cytosine C5 residue together with stacking forces contribute to the high antiproliferative activity. The metal(II)-assisted synthesis procedure of 5 is described, and the formation mechanism is proposed.     

MRI and neuropsychological correlates of carbon monoxide exposure: a case report

A 45-year-old woman experienced long-term, chronic exposure to carbon monoxide in the restaurant kitchen where she was employed as a cook. After returning to the restaurant after 5 days off work, she noticed that her symptoms returned immediately; she then aired out the room and called the gas company. Approximately 6 hr after a leak was detected, the patient went to the hospital, where her carboxyhemoglobin was found to be within normal limits and results of a neurologic examination were described as normal. Based on her symptoms, the patient believed she had been exposed to CO for at least 1 year before the leak was discovered. Initially, she experienced flu-like symptoms, which eventually resolved. At the time of her first neuropsychological evaluation (17 months after the exposure was identified), her persisting complaints included difficulties in reading, writing, speaking and word retrieval. The test results were consistent with secondary frontal lobe dysfunction associated with subcortical disorders such as those seen after CO exposure. Results of a subsequent neuropsychological examination (29 months postexposure) showed slight improvement in performance, but her performance was still consistent with mild frontal/subcortical dysfunction. Although the initial screening of a brain magnetic resonance image (MRI) performed 15 months after the exposure was interpreted as being within normal limits, two subsequent blind reviews of the same scans identified multiple bilateral lesions in the basal ganglia, which were consistent with chronic CO exposure. We present this case as an example of the utility of MRI and neuropsychological examinations in detecting central nervous system dysfunction secondary to CO exposure.     

Intralesional topotecan in advanced ovarian cancer: a clinical report,based on a preclinical study

The aim of this study was to evaluate the response of ovarian cancer to intralesionally administered topotecan. Preliminary experiments were carried out in nude mice subcutaneously grafted with three different human ovarian carcinoma cells (A2780, IGROV/DDP and SKOV-3). Topotecan was administered intravenously (i.v.: 10-15 mg/kg every 4th day for 4 times) or intralesionally (i.t.: single dose of 15-20 mg/kg) and tumor size changes/drug toxicity were evaluated. The results indicate that the sensitivity of the three tumor models was different (rank: A2780 > IGROV/DDP > SKOV-3) but, for each tumor line, the pattern of response was similar after i.v. and i.t. administration. No local toxicity was detected, but appreciable systemic toxicity (animal death rate) was observed in spite of the use of a single i.t. dose. The effects of intralesional topotecan administration were then assessed in a patient with an advanced, epithelial ovarian tumor (endometroid type, poorly differentiated histologic grade), already treated with cisplatin and paclitaxel. The treatment (7.5 mg/m(2)) was repeated three times and, although drug plasma levels were in the range generally reported following i.v. administration and typical systemic toxicity occurred, no tumor regression was observed and the patient died 14 months later. We conclude that the intralesional drug delivery is effective to achieve a rapid tumor shrinkage in large tumor lesions, but in the presence of drug resistance, either intrinsic or acquired, intratumor drug administration can not be recommended.