Microvascular disturbances in the colonic mucosa in antibiotic-associated haemorrhagic colitis: Involvement of platelet aggregation

An ultrastructural study of the colonic mucosa was performed in four patients with antibiotic-associated haemorrhagic colitis and new findings are reported. Colonoscopy was performed and biopsy specimens were obtained within 24 h of the onset of bloody diarrhoea. Colonoscopy demonstrated diffuse oedematous and haemorrhagic mucosa with erosions and white coat. Light microscopy revealed mucosal haemorrhage and inflammatory cell infiltration. Ultrastructurally, platelet aggregation was frequently present in the lumina of colonic mucosal capillaries, causing engorgement of red blood cells in adjacent microvessels. Mild to severe damage was observed in capillary endothelial cells, including discontinuity of basement membranes, gaps between endothelial cells and the destruction of capillaries. There was no evidence of microvascular spasm. In conclusion, our findings suggest that antibiotics directly or indirectly cause microcirculatory disturbances, which result in tissue damage and haemorrhage, in the colonic mucosa.     

Vitamin D-dependent rickets type I and type II

Two distinct hereditary defects, vitamin D-dependent rickets type I (VDDR I) and type II (VDDR II), have been recognized in vitamin D metabolism. VDDR I is suggested to be a deficiency of the renal 25-hydroxyvitamin D (25(OH)D)-1α-hydroxylase. Muscle weakness and rickets are the prominent clinical findings. A normal physiologic dose of 1α-hydroxyvitamin D₃ and 1,25-dihydroxyvitamin D₃ is sufficient to maintain remission of rickets in this disorder. VDDR II consists of a spectrum of intracellular vitamin D receptor (VDR) defects and is characterized by the early onset of severe rickets and associated alopecia. This can be attributed to mutations in the VDR gene. Massive doses of vitamin D analogs and calcium supplementation is usually required for the treatment; however, the response to therapy is sometimes variable.     

Intravascular papillary endothelial hyperplasia

Intravascular papillary endothelial hyperplasia (IPEH) was first described by Masson.1 It is characterized by the development of endothelial-lined papillary projections in a vascular lumen. In Japan the disease was first reported by Tanimura et al.² in 1976, and since then over 30 cases have been described. In this reort we describe a case of IPEH together with the review of these Japanese cases.     

Measurement of human hair growth by optical microscopy and image analysis

We have developed a quantitative method for measuring hair growth using optical microscopy and image analysis, and have used this to investigate the rate of growth in subjects with and without alopecia. The hairs were cut from an area 7-8 mm in diameter and 24 h and 72 h later, images of the areas were obtained using an optical microscope and were recorded on a video disc. Measurements of the regrowing hairs, placed parallel to the scalp using a glass slide attached to the front of the microscope, were made using the image analyser. In subjects with little or no baldness there was a clear difference between fast-growing hairs and resting or slow-growing hairs. However, in subjects with alopecia there was no such difference and the growth rate of all the hairs showed a continuous distribution. Using this method other parameters such as the number of hairs per unit area and hair diameter as well as grouping of the hairs could be measured.     

"Beak"-Plasty: A New Effective Modification of Z-Plasty

BACKGROUND: Because the "lateral limbs" resulting from conventional Z-plasty form a steep angle against the relaxation skin tension line (RSTL), they often develop hypertrophic change, whereas the "central limbs" become inconspicuous after being realigned parallel to the RSTL. OBJECTIVE: To alleviate the above-mentioned hypertrophic change of the lateral limbs, we modified the conventional Z-plasty and invented a new technique. Because the shape of the flap resembles a bird's beak, we call the technique "beak-plasty." The purpose of this study is to present the new technique. METHODS: The technique is described and effectiveness of the technique is reviewed on 21 patients. In particular, three representative cases are presented with photographs. RESULTS: In all patients, the lateral limbs of the flaps did not become hypertrophic after a minimum follow-up period of 9 months. CONCLUSIONS: Our technique can effectively reduce Z-plasty's risk of postoperative hypertrophy in the lateral limb. Therefore, it can make the scar less conspicuous than in conventional Z-plasty. For this advantage, we recommend our technique as an effective armament for scar revision. The authors have indicated no significant interest with commercial supporters.