A simple and consistent technique for ventricular catheter insertion using a tripod

Objective

For long-term preservation of ventriculo-peritoneal (VP) shunt function, it is essential to place the ventricular catheter tip above the foramen of Monro. But the free-hand technique for ventricular catheter passage is not consistent.

Methods

Supposing that a convex of skull matches to a sphere, in which the foramen of Monro is the center, a perpendicular direction from the surface of the sphere to inside always directs toward the center. The authors identified the range of skull where corresponded to the sphere by magnetic resonance imaging assessment and utilized tripod to achieve exactly perpendicular insertion of ventricular catheter. And an optimal length of catheter insertion was investigated by navigation system.

Results

The anterior–posterior range of the spherical portion was from coronal suture to 20 mm anterior, and the lateral range of it was between 15 and 35 mm lateral from sagittal suture. The optimal catheter length for insertion was between 55 and 58 mm from the brain surface. Ideal placement of a ventricular catheter tip was achieved in more than 90% of cases (31/34) with this technique.

Conclusion

Tripod-guided ventricular catheter insertion is a simple and reliable method for VP shunt at any angle of head-rotation.     

The impact of single nucleotide polymorphisms on human aldehyde oxidase

Aldehyde oxidase (AO) is a complex molybdo-flavoprotein that belongs to the xanthine oxidase family. AO is active as a homodimer, and each 150-kDa monomer binds two distinct [2Fe2S] clusters, FAD, and the molybdenum cofactor. AO has an important role in the metabolism of drugs based on its broad substrate specificity oxidizing aromatic aza-heterocycles, for example, N(1)-methylnicotinamide and N-methylphthalazinium, or aldehydes, such as benzaldehyde, retinal, and vanillin. Sequencing the 35 coding exons of the human AOX1 gene in a sample of 180 Italian individuals led to the identification of relatively frequent, synonymous, missense and nonsense single-nucleotide polymorphisms (SNPs). Human aldehyde oxidase (hAOX1) was purified after heterologous expression in Escherichia coli. The recombinant protein was obtained with a purity of 95% and a yield of 50 μg/l E. coli culture. Site-directed mutagenesis of the hAOX1 cDNA allowed the purification of protein variants bearing the amino acid changes R802C, R921H, N1135S, and H1297R, which correspond to some of the identified SNPs. The hAOX1 variants were purified and compared with the wild-type protein relative to activity, oligomerization state, and metal content. Our data show that the mutation of each amino acid residue has a variable impact on the ability of hAOX1 to metabolize selected substrates. Thus, the human population is characterized by the presence of functionally inactive hAOX1 allelic variants as well as variants encoding enzymes with different catalytic activities. Our results indicate that the presence of these allelic variants should be considered for the design of future drugs.     

Tumor-associated macrophages and angiogenesis: A statistical correlation that could reflect a critical relationship in ameloblastoma

Neoplasm growth is determined not only by the tumor cells themselves, but also by the tumor microenvironment. Increased densities of macrophages and activation of angiogenesis have been identified as common events in the progression of several neoplasms. Ameloblastoma is one of the most frequent odontogenic tumors and an excellent model for the study of neoplasm progression due to the different clinical variants that it exhibits. Here, by immunohistochemical studies using antibodies against CD68 and CD34, we evaluated the density of macrophages and microvessels associated to 45 paraffin-embedded ameloblastomas. In solid/multicystic ameloblastoma (SMA), we observed significantly higher densities of both macrophages and microvessels than in unicystic (UA) and desmoplastic (DA) ameloblastomas. Likewise, higher densities of macrophages and microvessels were found in UA than in DA. Furthermore, a predominance of intratumoral and peritumoral macrophage infiltrates was seen in SMA, while in UA, both macrophages and microvessels were also detected in the wall of the cysts. In contrast, DA had scant macrophages and microvessels, mainly situated distant from tumoral cells. In addition, a high correlation between macrophage and microvessel densities was observed in the samples (r = 0.9623). Our results suggest that these two tumor microenvironmental elements could have an important role during ameloblastoma progression.     

Interactive-plan technique conquers the disadvantages of volume-reducing hormone therapy in 125I permanent implantation for localized prostate cancer

Background  The purpose of this study was to assess the impact of hormone therapy on post-implant dosimetry in patients in whom pre-plan and interactive-plan techniques were used for transperineal brachytherapy against prostatic cancer. Methods  The subjects comprised 244 patients treated using ¹²⁵I seed implantation as monotherapy. The prescribed dose to the periphery of the prostate was 145 Gy. The pre-plan technique was used for 116 patients, and the interactiveplan technique for 128 patients. Hormone therapy was used in 71 patients (29.1%). The D90 (dose to 90% of prostate volume) of post-implant computed tomography (CT) analysis was assessed in both groups. In addition, the ratio of post-implant CT volume to preoperative ultrasonography (US) volume was assessed. Results  In the pre-plan group, D90 was significantly lower for patients who received hormone therapy than for those who did not (P = 0.035). However, in the interactive-plan group, D90 did not differ between patients with and without hormone therapy (P = 0.467). The CT-to-US prostate volume ratio was 1.022 for patients who received hormone therapy and 0.960 for patients who did not (P = 0.021). Conclusion  Post-traumatic swelling following implantation is increased by cessation of hormone therapy and may reduce D90. However, the present results suggest that the interactive-plan technique overcomes this disadvantage of hormone therapy.     

Regulation of gastroduodenal motility: acyl ghrelin, des-acyl ghrelin and obestatin and hypothalamic peptides

Real-time measurements for gut motility in conscious rats or mice combined with intracerebroventricular or intravenous injection of peptide agonists or antagonists allow us to understand the regulatory mechanism of gastrointestinal motility. Neuropeptide Y (NPY) in the arcuate nucleus in the hypothalamus stimulates the fasted motility in the duodenum, while urocortin in the paraventricular nucleus inhibits fed and fasted motility in the antrum and duodenum. Acyl ghrelin exerts stimulatory effects on the motility of the antrum and duodenum in both the fed and fasted state of animals. NPY Y2 and Y4 receptors in the brain may mediate the action of acyl ghrelin, and vagal afferent pathways might be involved in this mechanism. Des-acyl ghrelin exerts inhibitory effects on the motility of the antrum but not on the motility of the duodenum in the fasted state of animals. CRF type 2 receptor in the brain may mediate the action of des-acyl ghrelin, and vagal afferent pathways might not be involved in this mechanism. Obestatin exerts inhibitory effects on the motility of the antrum and duodenum in the fed state but not in the fasted state of animals. CRF type 1 and type 2 receptors in the brain may mediate the action of obestatin, and vagal afferent pathways might be partially involved in this mechanism.