Distortion and movement of the expander during skin expansion.

Distortion and movement of tissue expanders can cause expansion of the wrong area, such as the naevus or the scar that is to be resected. In 71 rectangular expanders, we examined the incidence of distortion (over 15 degrees) and movement (over 3 cm). We divided the expanders into three anatomical site groups: scalp, body, and extremities, and compared the complication rate between two study groups (distortion or movement, or not). In total, the incidence of distortion was 15/71 (21%) and that of movement 5/71 (7%). Distortion occurred mainly in the extremities (11/33,33%). The implanted expanders tended to move more often in the body part (3/15, 20%). In the extremities, the bigger the angle between the axis of the implanted expander and that of the extremity, the bigger the angle of distortion. Although the incidence of complications between the two groups was not significant, except for alteration in design of the flap, we recommend that these points should be considered when preoperative plans are being made for appropriate patients.     

Repeat operations in the management of clival chordomas: palliative surgery.

Some chordomas have a very poor prognosis because of their aggressive growth nature, but the efficacy of repeat operations for these cases has not been well documented. This report concerns 3 patients with aggressive chordoma of the clivus, who underwent operations 6 to 12 times over a period of 8 to 17 years because of symptomatic regrowth. Overall mean interval between repeat operations was 18 months with a range from 5 to 57 months and survival times were 9 to19 years after the first surgery. Main symptoms before each operation were diplopia and visual disturbance. Repeat palliative operations by intentional extradural debulking of the tumour to decompress offending neural structures, as well as maximal removal of the tumour, using appropriate skull base approaches, can mitigate progressive symptoms, and may result in better quality and some prolongation of life, although our patients gradually deteriorated neurologically throughout the clinical course.     

Ketamine Suppresses Platelet Aggregation Possibly by Suppressed Inositol Triphosphate Formation and Subsequent Suppression of Cytosolic Calcium Increase

Background: Ketamine has been shown to suppress platelet aggregation, but its mechanisms of action have not been defined. The purpose of the current study is to clarify the effects of ketamine on human platelet aggregation and to elucidate the underlying mechanisms of its action.

Methods: Platelet aggregation was measured using an eight-channel aggregometer, and cytosolic free calcium concentration was measured in Fura-2/AM-loaded platelets using a fluorometer. Inositol 1,4,5-triphosphate (IP3) was measured with use of a commercially available IP3 assay kit. To estimate thromboxane A2 (TXA2) receptor binding affinity and expression, Scatchard analysis was performed using [3H]S145, a specific TXA2 receptor antagonist. TXA2 agonist binding assay was also performed. The membrane-bound guanosine 5'-triphosphatase activity was determined using [[gamma]-32P]guanosine triphosphate by liquid scintillation analyzer.

Results: Ketamine (500 [mu]m) suppressed aggregation induced by adenosine diphosphate (0.5 [mu]m), epinephrine (1 [mu]m), (+)-9,11-epithia-11,12-methano-TXA2 (STA2) (0.5 [mu]m), and thrombin (0.02 U/ml) to 39.1 +/- 30.9, 46.3 +/- 4.3, -2.0 +/- 16.8, and 86.6 +/- 1.4% of zero-control, respectively. Ketamine (250 [mu]m-1 mm) also suppressed thrombin- and STA2-induced cytosolic free calcium concentration increase dose dependently. Although ketamine (2 mm) had no effect on TXA2 receptor expression and its binding affinity, it (1 mm) suppressed intracellular peak IP3 concentrations induced by thrombin and STA2 from 6.60 +/- 1.82 and 4.39 +/- 2.41 to 2.41 +/- 0.98 and 1.90 +/- 0.86 pmol/109 platelets, respectively, and it suppressed guanosine triphosphate hydrolysis induced by thrombin (0.02 units/ml) and STA2 (0.5 [mu]m) to 50.3 +/- 3.2 and 67.5 +/- 5.5%versus zero-control, respectively.     

Comparison of the vasodilator effects of thiopentone and pentobarbitone

The aim of this study was to elucidate the vasodilator mechanisms of barbiturates. In helical strips of dog mesenteric artery, the effects of pretreatment with thiopentone and pentobarbitone on the contractions induced by KCl (2.0 x 10(-2) M) and norepinephrine (10(-5) M) in normal bathing fluid, and those induced by norepinephrine and caffeine (2.5 x 10(-2) M) in Ca(++)-free fluid were tested, and their effects on caffeine-induced contractions in skinned strips were also examined. Thiopentone, at concentrations over 10(-4) M, inhibited the KCl-induced contractions in normal bathing fluid and those induced by caffeine in Ca(++)-free fluid and, at concentrations over 3 x 10(-4) M, inhibited norepinephrine-induced contractions in normal and Ca(++)-free bathing fluids significantly. Pentobarbitone, at concentrations over 3 x 10(-4) M, inhibited KCl- and norepinephrine-induced contractions in normal bathing fluid significantly, whereas contractions in Ca(++)-free fluid induced by norepinephrine and caffeine were inhibited only by a high concentration (10(-3) M) of pentobarbitone. Caffeine-induced contractions of chemically skinned fibres were more susceptible to inhibition by thiopentone than by pentobarbitone. These results suggest that the vasodilator effect of thiopentone is mediated via its intracellular inhibitory effect and that, in contrast, the vasodilator effect of pentobarbitone can be attributed mainly to its Ca(++)-channel blocking action.     

Localized wall thickening of the gallbladder mimicking a neoplasm

Clinical diagnosis of chronic cholecystitis is made based on diffuse hyperechoic thickening of the gallbladder wall as shown by ultrasonographic examination. We herein report three cases of chronic cholecystitis showing localized hypoechoic thickening of the gallbladder wall that mimicked gallbladder cancer by ultrasonography. Histologically, hypertrophy of the muscularis propria was a common characteristic finding in these three patients. A smooth surface of the inner hypoechoic layer of the thickened wall was considered to be a reliable finding in the differential diagnosis between this type of chronic cholecystitis and gallbladder cancer.     

Balloon cell nevus of the soft palate: an immunohistochemical and ultrastructural study

An ultrastructural analysis of oral balloon cell nevus of intramucosal type complemented with an immunohistochemical study was performed for the first time. The lesion was composed of large balloon cells with an admixture of small nevus cells and melanophages at the periphery. Balloon cells showed cytoplasmic accumulation of vacuoles of varying sizes and the presence of microgranular and vacuolated melanosomes were found. Residual cytoplasm contained no identifiable organelles. A spectrum of transitional forms between balloon cells and conventional nevus cells with microvacuoles was readily observed. Both cells exhibited intense immunoreactivity to multiple melanocytic markers. Ballooning phenomenon was not evident in melanophages containing a large amount of melanosome complex. It can be inferred, from the present and previous observations, that progressive vacuolization of melanosomes in nevomelanocytes may be responsible for the formation of peculiar ballooning appearance, suggesting an aberrant melanogenesis.     

A case of dermatofibrosarcoma protuberans in the skin over the breast

Dermatofibrosarcoma protuberans (DFSP) is a slow-growing but locally aggressive, fibrous tumor that has a high rate of local recurrence after surgical resection. This tumor occurs most commonly in the trunk and proximal extremities. In this report we present a case of dermatofibrosarcoma protuberans in the skin over the breast which was re-excised after pathological diagnosis, considering cosmetic aspects. Only three other cases of dermatofibrosarcoma protuberans of the anterior chest wall have been encountered in our hospital, and all of these cases were male. The presence of this tumor in the skin over the breast appears to be rare in females. Careful complete resection is recommended for this type of tumor.     

Isozyme selective induction of mouse pulmonary superoxide dismutase by the exposure to mercury vapor

Alterations in lung superoxide dismutase (SOD) isozymes after exposure of mice to mercury vapor were examined. Inhalation of mercury vapor (10 mg/m(3)) for 1 h by mice resulted in a higher accumulation of mercury in the kidney and lung compared to other organs, at 1 h after exposure. Under these conditions marked enhancement of protein content in bronchoalveolar fluid (BALF), attributed to lung injury, was observed. Exposure to mercury vapor caused a significant increase in the pulmonary Cu,Zn-SOD activity (1.32-fold at 48 h) whereas Mn-SOD activity was suppressed to 82% of the control level, suggesting different sensitivity to the metal inhalation. The selective induction of Cu,Zn-SOD protein (1.79-fold at 48 h) was confirmed by immunoblot analysis with polyclonal antibodies against these isozymes. These observations suggest that the selective induction of Cu,Zn-SOD at the translational level appears to occur as an initial defense against mercury-promoted oxidative stress.