Stiff fingers as an unwanted side effect of intravascular tadalafil gel abuse

The internet provides the public with unregulated access to a wide range of medications. We present the case of a 43-year-old man who purchased oral tadalafil gel on the internet and injected it into his left radial artery. He presented 48 hours after injection with signs of ischaemia distal to the injection site requiring a combination of medical and surgical treatment. This unique case highlights the potential dangers of unregulated access to medication and the consequences of intravascular injection of oral gels.

A dosimetric comparison of intensity-modulated proton therapy optimization techniques for pediatric craniopharyngiomas: a clinical case study

BACKGROUND

To evaluate the dosimetric characteristics of intensity-modulated proton therapy (IMPT) optimization techniques and pencil-beam scanning (PBS) nozzle designs on pediatric craniopharyngiomas.

PROCEDURE

We compared a double-scatter (DS) plan with IMPT plans using single-field uniform dose (SFUD) optimization or multi-field optimization (MFO) and different PBS nozzles. The clinical impacts of SFUD versus MFO, range shifters, and two different PBS nozzles were compared. For target coverage assessment, the conformity index and inhomogeneity coefficient were evaluated.

RESULTS

Although both proton therapy techniques achieved adequate target coverage, IMPT achieved a better conformity index of 0.78 versus 0.60 for DS. For the inhomogeneity coefficient, IMPT with MFO performed better than using SFUD or DS. MFO with the dedicated nozzle (MFO-DN) achieved the best result of 0.023, as compared to values of 0.03 or higher for the other plans. IMPT achieved lower doses to the normal tissues, as compared to DS; MFO-DN had the best results. The DN provided the best beam-spot characteristics and the sharpest lateral penumbra. MFO reduced the need for range shifters.

CONCLUSIONS

As compared to DS proton therapy for pediatric craniopharyngiomas, IMPT achieved significantly better target coverage and dose sparing of normal tissue. Nozzle designs that provided small beam spots and sharp lateral penumbra allowed for better target coverage and reduced dose to normal tissue. In the case of shallow targets, MFO, in contrast to SFUD, required minimal use of range shifters, which preserved the penumbra and the dosimetric advantage. MFO-DN proved to be the optimal technique for IMPT.

Proton therapy for skull base chordomas: an outcome study from the university of Florida proton therapy institute

Objectives Skull base chordoma is a rare, locally aggressive tumor located adjacent to critical structures. Gross total resection is difficult to achieve, and proton therapy has the conformal advantage of delivering a high postoperative dose to the tumor bed. We present our experience using proton therapy to treat 33 patients with skull base chordomas. Design Retrospective outcomes study. Setting University of Florida Proton Therapy Institute; 2007 to 2011. Participants A total of 33 patients with skull base chordomas received postoperative three-dimensional conformal proton therapy. The patients were 79% male and 6% diabetic; 27% had received a gross total resection. Main Outcome Measures The gross tumor/tumor bed received a dose between 77.4 CGE and 79.4 CGE. Local control and overall survival were tracked, and radiation toxicity was assessed using a modified Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer Late Radiation Morbidity Scoring Scheme. Results Median follow-up for all patients was 21 months. Local control and overall survival rates at 2 years were 86% and 92%, respectively. Grade 2 toxicity was observed in 18% of our cohort in the form of unilateral hearing loss partially corrected with a hearing aid. No grade 2 or higher optic or brainstem toxicities were observed. Conclusions Proton therapy is an effective treatment modality for skull base chordomas.

Proton therapy for head and neck cancer: rationale, potential indications, practical considerations, and current clinical evidence

There is a strong rationale for potential benefits from proton therapy (PT) for selected cancers of the head and neck because of the opportunity to improve the therapeutic ratio by improving radiation dose distributions and because of the significant differences in radiation dose distribution achievable with x-ray-based radiation therapy (RT) and PT. Comparisons of dose distributions between x-ray-based and PT plans in selected cases show specific benefits in dose distribution likely to translate into improved clinical outcomes. However, the use of PT in head and neck cancers requires special considerations in the simulation and treatment planning process, and currently available PT technology may not permit realization of the maximum potential benefits of PT. To date, few clinical data are available, but early clinical experiences in sinonasal tumors in particular suggest significant improvements in both disease control and radiation-related toxicity.

Dosimetric characterization of whole brain radiotherapy of pediatric patients using modulated proton beams

This study was designed to investigate dosimetric variations between proton plans with (PPW) and without (PPWO), a compensator for whole brain radiotherapy (WBRT). The retrospective study on PPW and PPWO in Eclipse and XiO systems and photon plans (XP) using controlled segments in Pinnacle system was performed on nine pediatric patients for craniospinal irradiations. DVHs and derived metrics, such as the homogeneity index (HI), the doses to 2%(D2%) and 5%(D5%) volumes, and mean dose (Dmean) of the whole brain (i.e., PTV), and the organs at risk (OARs) such as lens and skull, were obtained. The PPW plans from both Eclipse and XiO systems uncovered the following advantages: (1) encompassing a cribriform plate area with the 100% isodose line was better than either PPWO or XP, according to calculated two‐dimensional distributions of one patient; (2) the mean value of D5% for lens was reduced to 23.6% of DP from 54.1% for PPWO or 41.6% for XP; and (3) the mean value of Dmean for skull was reduced to 94.8% of DP from either 98.4% for PPWO or 98.3% for XP. However, the PPW plans also exposed several disadvantages including: (1) the HI of PTV increased to 7.7 from 4.7 for PPWO or 3.7 for XP; (2) D2% to PTV increased to 108.8% of DP from 104.8% for PPWO or 105.1% for XP; and (3) D5% to the skull increased to 104.9% of DP from 101.6% for PPWO or 103.4% of for XP. One‐half of the observed variations were caused by different penumbra on lateral profiles and distal fall‐off depth doses of protons in Eclipse and XiO. Because the utilization on the sharp proton distal fall‐off was limited for WBRT, the difference between PPW and PPWO or XP indicated no distinguishable improvement by using a compensator in proton plans.

PACS number: 87.55.‐x

Development of gluconeogenesis in neonatal rat liver. Effect of premature delivery

1. An assay method for the determination of phosphopyruvate carboxylase activity is described in which improved sensitivity is obtained by separation of the enzyme from interfering pyruvate kinase by zone sedimentation. 2. The molecular weight of rat liver phosphopyruvate carboxylase determined by zone sedimentation is about 68000. 3. Premature delivery of rat foetuses by uterine section results in the rapid appearance of phosphopyruvate carboxylase, but hexose diphosphatase and pyruvate carboxylase, already present in the foetal rat liver, are not significantly affected, and glucose 6-phosphatase activity is only slightly affected. 4. The rate of incorporation of [(14)C]pyruvate into glucose by liver slices is also greatly increased by premature delivery and there is a highly significant linear correlation between this process and the phosphopyruvate carboxylase activity.

Development of gluconeogenesis in neonatal rat liver. Effect of triamcinolone

1. The normal development of the key enzymes of gluconeogenesis in rat liver, glucose 6-phosphatase, hexose diphosphatase, phosphopyruvate carboxylase and pyruvate carboxylase, was measured during the neonatal period. 2. Glucose 6-phosphatase, hexose diphosphatase and pyruvate carboxylase are all present in the late foetal liver, but all the enzymes show an increase in activity after birth. 3. Phosphopyruvate carboxylase is not present in liver extracts from foetal rats, but activity appears immediately after birth and increases rapidly over the first day and then more slowly to reach its maximum at the fourth postnatal day. 4. The fluorinated synthetic glucocorticoid, triamcinolone, was administered to foetal rats at various gestation times by intraperitoneal injection in utero and the animals were killed at intervals between 4 and 48hr. later. 5. The administration of triamcinolone results in slight depression of glucose 6-phosphatase, and a more significant depression of hexose diphosphatase to about one-half its normal activity in foetal rat liver. 6. Triamcinolone injection is without effect on pyruvate carboxylase activity and does not result in premature appearance of phosphopyruvate carboxylase in foetal rat liver. 7. Pyruvate kinase and aspartate amino-transferase activities in foetal rat liver are both depressed by triamcinolone treatment, whereas phosphofructokinase activity is elevated. 8. Tyrosine amino-transferase activity in foetal rat liver is markedly elevated in animals exposed to triamcinolone for 10hr. or more, but the effect is only observed in animals close to term. 9. The results are discussed in relation to mechanisms involved in the initial synthesis of tissue-specific enzymes in developing tissues, and it is concluded that glucocorticoids do not initiate the synthesis of the gluconeogenic enzymes.