Folate Receptor Targeted Alpha-Therapy Using Terbium-149

Terbium-149 is among the most interesting therapeutic nuclides for medical applications. It decays by emission of short-range α-particles (Eα = 3.967 MeV) with a half-life of 4.12 h. The goal of this study was to investigate the anticancer efficacy of a 149Tb-labeled DOTA-folate conjugate (cm09) using folate receptor (FR)-positive cancer cells in vitro and in tumor-bearing mice. 149Tb was produced at the ISOLDE facility at CERN. Radiolabeling of cm09 with purified 149Tb resulted in a specific activity of ~1.2 MBq/nmol. In vitro assays performed with 149Tb-cm09 revealed a reduced KB cell viability in a FR-specific and activity concentration-dependent manner. Tumor-bearing mice were injected with saline only (group A) or with 149Tb-cm09 (group B: 2.2 MBq; group C: 3.0 MBq). A significant tumor growth delay was found in treated animals resulting in an increased average survival time of mice which received 149Tb-cm09 (B: 30.5 d; C: 43 d) compared to untreated controls (A: 21 d). Analysis of blood parameters revealed no signs of acute toxicity to the kidneys or liver in treated mice over the time of investigation. These results demonstrated the potential of folate-based α-radionuclide therapy in tumor-bearing mice.

Synthesis and incorporation into a-DNA of a novel conformationally constrained alpha-nucleoside analogue

We describe the synthesis and incorporation into alpha-DNA of a novel conformationally constrained alpha-nucleoside analogue. The carbohydrate part of this analogue was prepared in 4 steps from the known bicyclic precursor 1 via a stereospecific, intramolecular, Et 3B mediated radical addition to a keto-function as the key step. The thus obtained intermediate 4 was transformed stereoselectively into the corresponding alpha-nucleoside analogues 7 and 8 containing the bases adenine and thymine, and were further elaborated into the phosphoramidite building blocks 11 and 12 . Both building blocks were incorporated into alpha-oligodeoxynucleotides and their pairing behavior to parallel complementary DNA studied by UV-melting experiments. Single substitutions of alpha-deoxyribnucleoside units by the new analogues in the center of duplexes were found to be thermally destabilizing by only -0.8 to -3.1›C.

Alpha-Chloralose-Intoxikation bei zwei Chihuahuas, Fallvorstellung und Literaturübersicht.

Gegenstand und Ziel: Darstellung einer Vergiftung mit Alpha-Chloralose anhand von zwei Fällen sowie Zusammenstellung der diesbezüglichen Literatur. Patienten: Zwei Chihuahua-Hündinnen (3- bzw. 12-jährig) wurden nach Aufnahme von mit Alpha-Chloralose präparierten Fleischwürstchen vorgestellt. Ergebnisse: Beide Tiere zeigten Hypoventilation und neurologische Symptome, wobei sich eine Hündin mit Koma und Hypothermie präsentierte, die andere mit Koma, Krämpfen und normaler Temperatur. Initial stand die Aufrechterhaltung und Überwachung der Vitalfunktionen sowie die Dekontamination im Vordergrund. Beide Hunde wurden symptomatisch behandelt und konnten das Tierspital nach 3 Tagen verlassen. Aufgrund der neurologischen Symptome sind bei solchen Patienten andere ZNS-depressive Toxine ebenfalls in Betracht zu ziehen. In diesem Fall wurde das Toxin Alpha-Chloralose nachgewiesen. Schlussfolgerung und klinische Relevanz: Alpha-Chloralose-Intoxikationen sind bisher selten beschrieben. Zu den Symptomen zählen Hypothermie, Hypoventilation, Krämpfe, Koma, Narkose, Miosis, Hypersalivation, bronchiale Hypersekretion und Bradykardie. Eine Intoxikation mit Alpha-Chloralose sollte daher sowohl bei komatösen als auch krampfenden Tieren als Differenzialdiagnose in Betracht gezogen werden.

Primary structure and evolutionary relationship between the adult alpha-globin genes and their 5'-flanking regions of Xenopus laevis and Xenopus tropicalis

To investigate the evolution of globin genes in the genus Xenopus, we have determined the primary structure of the related adult alpha I- and alpha II-globin genes of X. laevis and of the adult alpha-globin gene of X. tropicalis, including their 5'-flanking regions. All three genes are comprised of three exons and two introns at homologous positions. The exons are highly conserved and code for 141 amino acids. By contrast, the corresponding introns vary in length and show considerable divergence. Comparison of 900 bp of the 5'-flanking region revealed that the X. tropicalis gene contains a conserved proximal 310-bp promoter sequence, comprised of the canonical TATA and CCAAT motifs at homologous positions, and five conserved elements in the same order and at similar positions as previously shown for the corresponding genes of X. laevis. We therefore conclude that these conserved upstream elements may represent regulatory sequences for cell-specific regulation of the adult Xenopus globin genes.

Severe postoperative wound healing disturbance in a patient with alpha-1-antitrypsin deficiency: the impact of augmentation therapy

Wound healing disturbance is a common complication following surgery, but the underlying cause sometimes remains elusive. A 50-year-old Caucasian male developed an initially misunderstood severe wound healing disturbance following colon and abdominal wall surgery. An untreated alpha-1-antitrypsin (AAT) deficiency in the patient's medical history, known since 20 years and clinically apparent as a mild to moderate chronic obstructive pulmonary disease, was eventually found to be at its origin. Further clinical work-up showed AAT serum levels below 30% of the lower reference value; phenotype testing showed a ZZ phenotype and a biopsy taken from the wound area showed the characteristic, disease-related histological pattern of necrotising panniculitits. Augmentation therapy with plasma AAT was initiated and within a few weeks, rapid and adequate would healing was observed. AAT deficiency is an uncommon but clinically significant, possible cause of wound healing disturbances. An augmentation therapy ought to be considered in affected patients during the perioperative period.

The relationship of mutations in alpha- and beta-tubulin to microtubule assembly and anti-mitotic drug resistance

The mechanisms responsible for anti-cancer drug (including Taxol) treatment failure have not been identified. In cell culture model systems, many β-tubulin, but very few α-tubulin, mutations have been associated with resistance to Taxol. To test what, if any, mutations in α-tubulin can cause resistance, we transfected a randomly mutagenized α-tubulin cDNA into Chinese hamster ovary (CHO) cells and isolated drug resistant cell lines. A total of 12 mutations were identified in this way and all of them were confirmed to confer Taxol resistance. Furthermore, all cells expressing mutant α-tubulin had less microtubule polymer. Some cells also had abnormal nuclei and enlarged cell bodies. The data indicate that α-tubulin mutations confer Taxol resistance by disrupting microtubule assembly, a mechanism consistent with a large number of previously described β-tubulin mutations. ^ Because α- and β-tubulin are almost identical in their three dimensional structure, we hypothesized that mutations discovered in one subunit, when introduced into the other, would produce similar effects on microtubule assembly and drug resistance. 9 α- and 2 β-tubulin mutations were tested. The results were complex. Some mutations produced similar changes in microtubule assembly and drug resistance irrespective of the subunit in which they were introduced, but others produced opposite effects. Still one mutation produced resistance when present in one subunit, yet had no effect when present on the other; and one mutation that produced Taxol resistance when present in α-tubulin, resulted in assembly-defective tubulin when it was present in β-tubulin. The results suggest that in most cases, the same amino acid modification in α- and β-tubulin affects the microtubule structure and assembly in a similar way. ^ Finally, we tested whether three β-tubulin mutations found in patient tumors could confer resistance to Taxol by recreating the mutations in a β-tubulin cDNA and transfecting it into CHO cells. We found that all three mutations conferred Taxol resistance, but to different extents. Again, microtubule assembly in the transfectants was disrupted, suggesting that mutations in β-tubulin are a potential problem in cancer therapeutics. ^

Association of TNF-alpha genetic variants with HPV-associated oral cancer risk---a case-control study

The incidence of OSCC in younger population and in those who never smoked or drank has increased since the last decade. This increase may be attributable to increase of infection with HPV. The pro-inflammatory cytokine TNF-&agr; has the role in the pathogenesis of chronic inflammatory diseases and was found to control HPV infection in cervical cancer studies. Our study aimed to investigate the association between the four polymorphisms located in TNF-&agr; promoter region, -308(rs1800629), -857(rs1799724), -863(rs1800630) and -1031(rs1799964), and the risk of HPV-related OSCC. In this hospital-based case-control study, 325 cases and 335 controls were included. We found that HPV 16 seropositivity was associated with an increased risk of oral cancer (OR = 3.1, 95% CI, 2.1–4.6). Each of the polymorphism showed to increase the risk of HPV-related OSCC. And after combining the risk genotypes and using the low-risk group (0–1 combined risk genotypes) and HPV16 seronegativity as the reference group, only the high-risk groups (3–4 combined risk genotypes) and HPV16 seronegativity were associated with a low OR of 1.8 (95% CI, 1.1–2.8), while the low-risk and high-risk groups and HPV16 seropositivity were significantly associated with a higher OR of 2.7 (95% CI, 1.3–5.8) and 8.5 (95% CI, 3.7–19.4), respectively. In addition, the joint effects were greater among the young subjects (aged<50), males, never smokers or never drinkers, and patients with oropharyngeal cancer. Overall, the four TNF-&agr; polymorphisms, individually or collectively, would result in a significantly increased risk for HPV16-associated oral cancer in a non-Hispanic white population. More large sized studies are needed for future investigation.^