[A Case of a Migrating Central Venous Catheter in the Internal Jugular Vein Diagnosed Using Ultrasonography in a Patient with Right-Sided NeckPain during Chemotherapy].

We report a case of a migrating central venous(CV)catheter with thrombosis in the internal jugular vein that was diagnosed using ultrasonography in a patient complaining of neck pain during chemotherapy. A 57-year-old man with distant metastasis at 1 year after laparoscopic Hartmann operation for rectal cancer was transported to the emergency department by ambulance complaining of severe right-sided neck pain. On that day, his 6th course of chemotherapy with modified FOLFOX6 (levofolinic acid, 5-fluorouracil[5-FU], oxaliplatin[L-OHP])and panitumumab was administered using a CV port that had been placed 3 months previously from the right subclavian vein in the superior vena cava, and verified using radiography. Cervical ultrasonography revealed line migration, with a surrounding low echoic area without a Doppler signal in the right internal jugular vein. This migration was also observed on the radiograph. These findings indicated migration of the CV catheter with thrombosis. After admission, the CV catheter was removed, a new one was inserted from the left subclavian vein in the superior vena cava, and a direct oral anticoagulant was administered to treat the thrombosis. Two days later, his neck pain, which was caused by phlebitis that was probably induced by L-OHP or continuous 5-FU, disappeared. We should consider the possibility of CV catheter issues, including migration or damage, when patients experience neck pain during chemotherapy. Additionally, the present case demonstrated the utility of cervical ultrasonography in diagnosing CV catheter migration, as well as thrombosis.

Differences between right- and left-sided colon cancer in patient characteristics, cancer morphology and histology.

BACKGROUND AND AIM: Recently, the clinical and biological differences between right- and left-sided colon cancers have been widely debated. However, close analyses of these clinical differences, based on large-scale studies, have been scarcely reported. METHODS: A total of 3552 consecutive Japanese colorectal cancer cases were examined and the clinical differences between right- and left-sided colon cancer cases were investigated. RESULTS: The proportion of right-sided colon cancer was relatively high in patients aged less than 40 years (33%) and more than 80 years (43%). The proportion of right-sided colon cancer in patients aged 40-59 years was relatively low (male 22% and female 29%). In male patients the proportion increased in the 70-79 years age group (30%), while in female patients the proportion increased in the 60-69 years age group (39%). Right-sided colon cancer was more likely to be detected at an advanced stage (T1 stage; left 22%, right 15%) (P < 0.01) with severe symptoms. Polypoid-type early cancer was dominant in the left colon (left 59%; right 40%) (P < 0.01), while the proportion of flat-type early cancer in the right colon was significantly higher than that in the left colon (left 25%; right 44%) (P < 0.01). CONCLUSIONS: Specific age distribution of right-sided colon cancer was observed and the difference between male and female patients was highlighted. Other clinical features also differed between right- and left-sided colon cancer, suggesting that different mechanisms may be at work during right and left colon carcinogenesis.

Stereoisomerization of Cyclic Silanols.

Stereoisomerization of readily available all-cis-1,3,5,7-tetrahydroxy-1,3,5,7-tetraisobutylcyclotetrasiloxane (1 a) was carried out under acidic conditions to afford cis-trans-cis (1 b), all-trans (1 c), and cis-cis-trans (1 d) isomers. The compounds in the reaction mixture could be easily separated into 1 a and a mixture of 1 b, 1 c, and 1 d by the treatment with chloroform. Compounds 1 b, 1 c, and 1 d were further separated and isolated, and each structure was identified. The experimental results indicated that the most plausible mechanism is a substitution reaction at the silicon center via a pentacoordinate intermediate without a cyclic siloxane bond cleavage reaction. The obtained isomer 1 a or 1 b further reacted with dichlorodiphenylsilane in the presence of triethylamine to give syn-type laddersiloxane (2 a) or anti-type laddersiloxane (2 b), respectively.