Katsunori Niitsuma

Mechanical anisotropy in cobra skin is related to body movement.

The mechanical breaking stress and strain of cobra leather, along with their mechanical anisotropies, were studied in relation to body movement. The mechanical breaking strain in the transverse direction (TD), which was perpendicular to the direction (CCD) from the caudal to the cranial end, was much larger around the dorsum, and slightly larger around the abdomen, than that in the CCD. The mechanical strain is closely related to the expansion of skin. The mechanical anisotropy of cobra leather was relatively large in the dorsum, but smaller in the abdomen. These findings indicate that it was comparatively easy for the cobra body to expand preferentially in the TD around the dorsum and also to expand roughly equally in all directions around the abdomen, whereas expansion of the dorsum in the CCD was restricted by the spinal column. These findings also suggest that the strong mechanical anisotropy in cobra leather is closely related to the motion of the skin around the waist, which accompanies movement of the body.

Aesthetic reconstruction of a defect in the skin of the upper lip using a hatchet flap

Abstract Reconstruction of the upper lip requires symmetrical reconstruction of the free border according to the aesthetic principle. We have reconstructed this area with a hatchet flap, so that the scars match the subunit line as far as possible by rotation and advancement of the flap. We operated on six patients. The lower pedicled flap was used in 4 cases and the upper pedicled flap in 2, who also needed reconstruction of the vermillion. In one patient the scar did not match the nasolabial fold. For the upper pedicled cases, scars made on the vermillion were not conspicuous. However, trap door deformity occurred in half, which was a disadvantage. We think that our flap is useful, because it leaves a minimal scar in an inconspicuous area.

Recurrence of cutaneous lymphangioma after surgical resection: its features and manner

Twenty-five cutaneous lymphangiomas were treated surgically. The recurrence rate of mixed type lymphangioma was higher than the other types. The recurrence rate of the patients with lesion present at birth was significantly higher than that of the patients in whom the lesion occurred later. The interval from age at onset to the first operation was significantly shorter in the patients without recurrence than in the patients with recurrence. In conclusion, our study shows that the lesion must be resected as early as possible to prevent recurrence. Moreover, the following should be specially considered; recurrence rate is higher in mixed type lymphangioma, recurrence is more likely to occur when the interval from age at onset to the first operation is long or in the patients with a lesion present at birth.

Localization and expression of R-cadherin in skeletal muscle following nerve injury.

Rats in which the sciatic nerves were cut were divided into two groups: animals with nerve sutured and animals with nerve not sutured. In the unsutured group, the levels of R-cadherin expression increased and then decreased to values lower than those of controls. In the sutured group, the levels of R-cadherin expression increased and then decreased to almost control values. These results suggest that R-cadherin plays some role in cells of normal and regenerating muscles.

Adult umbilical hernia with vertical dislocation.

We present a case of adult umbilical hernia with vertical dislocation along the abdominal wall. The hernial sac arose from the internal ring and connected to the umbilicus 20 mm below the internal ring. The postoperative course was uneventful. Two years and four months after the operation there was no evidence of recurrent hernia even when abdominal pressure was increased, and the umbilicus looked acceptable. An umbilical hernia is usually within the umbilicus. The hernial sac arose from the internal ring so should be called an umbilical hernia not an epigastric hernia. It is unusual that the umbilical hernia dislocates vertically along the abdominal wall, while the umbilicus stays depressed. This atypical form of umbilical hernia has not been described previously as far as we know.

Differential changes in the expression level of M-Cadherin in denervation and reinnervation processes following nerve injury

The localization and the expression level of M-cadherin in skeletal muscle was investigated following nerve injury. The rats used in the study, in which the sciatic nerves were cut, were divided into two groups; the nerve was sutured (sutured group) or not sutured (unsutured group). In both groups, the level of M-cadherin expression decreased after the first postoperative week. The decreased level returned to the control level in the sutured group, but it did not return to the control level in the unsutured group. Immunofluorescence staining was observed around the muscular membrane at the 9th, 12th, 16th, 20th, and 24th postoperative weeks in the sutured group. These results suggest that M-cadherin plays a role in maintaining intercellular adhesion around the muscular membrane.