Surgical Factors Affecting Changes in Ocular Surface Dynamics in the Early Postoperative Period After 25-Gauge Vitrectomy.

OBJECTIVES: Because vitrectomy-associated postoperative ocular surface changes are not well known, we evaluated such changes before and after vitrectomy in eyes with posterior segment diseases and investigated their associations with patients' characteristics and surgical procedures. METHODS: Thirty-five eyes of 32 consecutive patients (16 women; average age 66.6±11.1 years) were included in this prospective, noncomparative case series from tertiary care university hospital. Contact lens wearers and patients with history of ocular surgery or regular use of topical eyedrops were excluded. Patients had undergone primary 25-gauge vitrectomy at Osaka University Hospital in Japan between July and December 2016. Tear break-up time (TBUT), corneal and conjunctival fluorescein staining score (FSS), and tear meniscus height (TMH) were evaluated before, 1 week after, and 1 month after vitrectomy. RESULTS: Conjunctival FSS and TMH were significantly higher at 1 week after vitrectomy than preoperatively. However, they decreased significantly 1 month after. Changes in TBUT and corneal FSS showed a similar course at 1 week, but this was not statistically significant. Multiple linear regression analysis showed no significant correlation between significantly increased ocular parameters and patients' characteristics. By contrast, surgical time and combined cataract surgery significantly contributed to increased and decreased conjunctival FSS, respectively (P=0.011 and 0.033, respectively). Sclerotomy site suturing significantly contributed to increased TMH (P=0.025). CONCLUSIONS: We showed associations between ocular surface changes and specific surgical procedures. Caution should be exercised to minimize the effect of surgical procedures on the ocular surface during vitrectomy.

Colonic hydrogen sulfide-induced visceral pain and referred hyperalgesia involve activation of both Ca(v)3.2 and TRPA1 channels in mice.

Luminal hydrogen sulfide (H(2)S), a gasotransmitter, causes colonic pain / referred hyperalgesia in mice, most probably via activation of T-type Ca(2+) channels. Here we analyzed the mechanisms for H(2)S-induced facilitation of colonic pain signals. Intracolonic administration of NaHS, an H(2)S donor, evoked visceral pain-like nociceptive behavior and referred hyperalgesia in mice, an effect abolished by NNC 55-0396, a selective T-type Ca(2+)-channel blocker, or by knockdown of Ca(v)3.2. AP18, a TRPA1 blocker, also prevented the NaHS-induced colonic pain and referred hyperalgesia. These findings demonstrate that H(2)S-induced colonic pain and referred hyperalgesia require activation of both Ca(v)3.2 and TRPA1 channels in mice.

Using superparamagnetic iron oxide-enhanced MRI to differentiate metastatic hepatic tumors and nonsolid benign lesions.

OBJECTIVE: We evaluated the ability of superparamagnetic iron oxide (SPIO)-enhanced MRI to differentiate solid metastatic tumors and nonsolid benign lesions by clarifying the characteristic signal-intensity pattern of each lesion on SPIO-enhanced T2-weighted and heavily T1-weighted gradient-echo images. MATERIALS AND METHODS: SPIO-enhanced MRI was performed using a 1.5-T system in 33 consecutive patients without cirrhosis who had 81 focal hepatic lesions (42 cysts, 13 hemangiomas, 26 metastatic tumors). The relative signal intensity of lesions on SPIO-enhanced heavily T1- and T2-weighted gradient-echo images was classified into one of the following three categories: high intensity, isointensity, or low intensity relative to the surrounding liver parenchyma. The diagnostic accuracy for differentiating solid metastatic tumors from nonsolid benign lesions (cysts or hemangiomas) was determined. RESULTS: A combination of the relative signal intensity of the lesion on T2- and heavily T1-weighted gradient-echo images could be classified into the following five categories: high intensity and high intensity (category 1), high intensity and isointensity (category 2), high intensity and low intensity (category 3), isointensity and isointensity (category 4), and isointensity and low intensity (category 5). According to these categories, category 1 contained two hemangiomas, category 2 had 11 hemangiomas, category 3 had 25 metastatic tumors and two cysts, category 4 had three cysts, and category 5 had 37 cysts and one metastatic tumor. When a tumor with a relative signal intensity of categories 1 or 2 was considered to be a hemangioma (category 3 metastatic tumors and categories 4 and 5 cysts), diagnostic accuracy for characterizing such hepatic lesions was 96% (78/81). CONCLUSION: When evaluating metastatic liver tumors on SPIO-enhanced MRI, we recommend that heavily T1- and T2-weighted gradient-echo images be obtained with our parameters to exclude hemangiomas or cysts.

Detection of hepatocellular carcinoma: comparison of dynamic MR imaging with dynamic double arterial phase helical CT.

OBJECTIVE: Three-dimensional (3D) Fourier transformation-enhanced fast gradient-echo sequences with a special spectral inversion recovery pulse and fat suppression developed for abdominal imaging, including MR angiography, can show enhanced areas clearly. The purpose of this study was to evaluate the efficacy of dynamic MR imaging with the pulse sequences for the detection of hypervascular hepatocellular carcinoma by comparing it with that of dynamic helical CT with double arterial phase imaging. SUBJECTS AND METHODS: Fifty-three patients with 103 hypervascular hepatocellular carcinoma nodules who underwent both dynamic MR imaging with 3D Fourier transformation-enhanced fast gradient-echo sequences with a special spectral inversion recovery pulse and dynamic helical CT with double arterial phase imaging were enrolled in the study. For dynamic MR imaging, unenhanced, arterial, portal venous, and equilibrium phase images were obtained before and approximately 19, 60, and 120 sec, respectively, after injection of gadopentetate dimeglumine. Three observers independently interpreted the images obtained with each technique in a blinded manner and in random order. RESULTS: Mean sensitivity and positive predictive values of CT for hypervascular hepatocellular carcinoma (66% and 97%, respectively) were higher than those of MR imaging (63% and 96%, respectively), but there was no significant difference in detecting sensitivity among the observers (p < 0.05). CT and MR imaging were complementary, with some tumors undetected by CT but revealed on MR imaging. There was also no significant difference in A(z) values between CT (0.74) and MR imaging (0.71) (p < 0.05). CONCLUSION: Dynamic MR imaging with 3D Fourier transformation-enhanced fast gradient-echo sequences with a special spectral inversion recovery pulse is recommended to improve the detection of hypervascular hepatocellular carcinoma nodules in addition to the use of dynamic helical CT with double arterial phase imaging.

Detection of hypervascular hepatocellular carcinoma by dynamic magnetic resonance imaging with double-echo chemical shift in-phase and opposed-phase gradient echo technique: comparison with dynamic helical computed tomography imaging with double arterial phase.

PURPOSE: The technique of double-echo chemical shift gradient echo magnetic resonance imaging (MRI) with the fast low-angle shot (double-echo FLASH) sequence provides in-phase and opposed-phase images in a single breath hold. The purpose of this study was to evaluate the efficacy of dynamic MRI with double-echo FLASH imaging for the detection of hypervascular hepatocellular carcinoma by comparing it with dynamic helical computed tomography (CT) imaging with double arterial phase. MATERIALS AND METHODS: Twenty-nine patients with 67 hypervascular hepatocellular carcinoma nodules who underwent both dynamic MRI with double-echo FLASH imaging (repetition time/echo time/flip angle: 160/3.6, 7.0/80 degrees ) and dynamic helical CT imaging with double arterial phase were enrolled in the study. For dynamic MRI, precontrast, arterial, portal venous, and equilibrium phase images were obtained before and approximately 19, 60, and 120 seconds, respectively, after intravenous injection of 0.1 mmol/kg of gadopentetate dimeglumine at a rate of 2 ml/s. For dynamic CT imaging, quadraphase images, including early arterial, late arterial, portal venous, and equilibrium phases, were obtained serially approximately 20, 30, 70, and 180 seconds, respectively, after intravenous administration of 2 ml/kg of 300 mgI/ml of nonionic contrast medium at a rate of 5 ml/s. Three masked observers independently interpreted images obtained with each technique in random order, separately and without patient identifiers. Sensitivity and positive predictive values as well as the area below the alternative-free response receiver operating characteristic curve (Az) for each imaging technique were calculated and compared statistically. RESULTS: Mean sensitivity and positive predictive values of MRI for hypervascular hepatocellular carcinoma were 48% and 94%, respectively, and those of CT imaging were 47% and 91%, respectively. In 11 (38%) of the 29 patients, at least one observer judged dynamic MRI to be superior, whereas in 5 patients (17%), dynamic CT was judged to be superior. There was no significant difference in the sensitivity and positive predictive values between these techniques (p > 0.05). There was no significant difference either in mean Az values between CT (0.55) and MRI (0.57) (p = 0.61). CONCLUSION: Dynamic MRI with double-echo FLASH imaging can detect hypervascular hepatocellular carcinoma as well as dynamic helical CT imaging with double arterial phase.