Takehiko Ohura

Evaluation of blood flow by laser speckle image sensing. Part 1

A new method is proposed to visualize the microcirculation map using a dynamic laser speckle effect. A skin surface is illuminated by He-Ne laser line spot and its image speckle is detected by a CCD array sensor. The erence between a pair of output data for successive scannings of the image speckles at the sensor plane was calculated and integrated for each pixel. The results were displayed in color graphics showing the spatial variation of the flow level in the area of interest.

A study on bone induction in hydroxyapatite combined with bone morphogenetic protein

Our present study consisted of an implantation of artificially made hydroxyapatite (HAP) ceramic pellets under the periosteum of the rabbit skull with subsequent inspection of further progress of bone formation and also of an evaluation of the effects of bone morphogenetic protein (BMP). The results revealed that the alkali phosphatase (AL-P) activity of the pellets was elevated only in those of the bone morphogenetic protein group. The results of determination of bone mineral density at the site of the pellets revealed that the increase in bone mineral density was the most remarkable in the bone morphogenetic protein group rather than the control group. The results of the histopathologic examinations revealed that marginal bone formation was found in the pores on the surface between the pellets and the skull in the control group and in the collagen group, whereas in the bone morphogenetic protein group very active bone formation was found not only on the interface in contact with the skull but also surrounding the whole pellet. It also was noted in the animals in the bone morphogenetic protein group that the pellets were corrupted from the peripheries and then absorbed into the newly formed bone. From these results, the efficacy of the hydroxyapatite-collagen-bone morphogenetic protein complex was made clear, and applications in clinical practice are expected in the near future.

Blood flow observed by time-varying laser speckle

The temporal statistics of laser speckle from vascular tissues on skin surface have been measured. Based on a temporal spectral analysis of the speckle signal, a new method of monitoring skin blood flow is proposed.

Dilemmas in measuring and using pressure ulcer prevalence and incidence: an international consensus

Pressure ulcer prevalence and incidence data are increasingly being used as indicators of quality of care and the efficacy of pressure ulcer prevention protocols. In some health care systems, the occurrence of pressure ulcers is also being linked to reimbursement. The wider use of these epidemiological analyses necessitates that all those involved in pressure ulcer care and prevention have a clear understanding of the definitions and implications of prevalence and incidence rates. In addition, an appreciation of the potential difficulties in conducting prevalence and incidence studies and the possible explanations for differences between studies are important. An international group of experts has worked to produce a consensus document that aims to delineate and discuss the important issues involved, and to provide guidance on approaches to conducting and interpreting pressure ulcer prevalence and incidence studies. The groups main findings are summarised in this paper.

Evaluation of effects of nutrition intervention on healing of pressure ulcers and nutritional states (randomized controlled trial)

The objective of this study was to evaluate the effects of nutrition intervention on nutritional states and healing of pressure ulcers by standardizing or unified factors including nursing, care and treatment in a multicenter open randomized trial. Tube‐fed patients with Stage III–IV pressure ulcers were selected. The control group (30 patients) received the same nutrition management as before participating in this trial, whereas the intervention group (30 patients) was given calories in the range of Basal Energy Expenditure (BEE) × 1.1 × 1.3 to 1.5. The intervention period was 12 weeks. The efficacy and safety were evaluated based on the nutritional states and the sizes of ulcers (length × width), and on the incidence of adverse events related to the study, respectively. The calories administered to the control and intervention groups were 29.1±4.9 and 37.9±6.5 kcal/kg/day, respectively. Significant interactions between the presence or absence of the intervention and the intervention period were noted for nutritional states (p<0.001 for body weight, p<0.05 for prealbumin). Similarly, the size of ulcers differed significantly between subjects in the intervention group and in the control group (p<0.001). The results suggest that nutrition intervention could directly enhance the healing process in pressure ulcer patients.

Influence of external forces (pressure and shear force) on superficial layer and subcutis of porcine skin and effects of dressing materials: Are dressing materials beneficial for reducing pressure and shear force in tissues?

The purpose of this study was to measure the impact of external shear force and pressure on a superficial layer of skin and subcutaneous layer with an underlying bony prominence, and also to verify how the influence of these external forces can be reduced after dressings are applied. For this purpose, an experimental model was prepared, consisting of porcine skin and a Predia sensor capable of measuring pressure and shear force simultaneously. External force was applied to the skin model using a 1 kg weight consisting of metal beads. As a result, the control of the shear force value in the subcutaneous layer became approximately 35% smaller than the control in the superficial layer. The shear forces present in the subcutaneous layer were significantly reduced to within 31–45% when compared with the control values, depending on the dressing applied. Regarding the maximum pressures in the subcutaneous layer, the pressure measured following movement was 2.4 times higher in the control than the static pressure and they were also 1.3–1.8 times higher than the static pressure in all instances with the dressing tested. All the dressing materials tested proved to be effective in reducing pressure in the subcutaneous layer compared with the control. Film dressings and hydrocolloid dressings were more effective than hydropolymer and hydrocellular dressings. From the above results, we conclude that efforts made to reduce shear force and pressure may be clinically important.

Superiority of the fasciocutaneous flap in reconstruction of sacral pressure sores.

The gluteal maximus muscle has been used in the treatment of sacral pressure sores since the 1970s. However, it is noted that the muscle portion of the transferred flap shows highly atrophic degeneration and the muscle itself is not suitable tissue for covering the pressure-bearing area. We have managed various fasciocutaneous flaps as the first choice for reconstruction of sacral pressure sores and obtained good results. The fasciocutaneous flap has an anatomical structure that resists physical stimulation or external pressure and an abundant blood supply via its fascial plexus. In addition, if we use a gluteal maximus myocutaneous flap at first, some fasciocutaneous flaps are compromised because of the design and blood supply. We suggest that the fasciocutaneous flap has the first priority and is superior to the gluteal maximus myocutaneous and muscle flaps in reconstruction of sacral pressure sores.

Crystalline lamellae in the endothelial cells of a type of hemangioma characterized by the proliferation of immature endothelial cells and pericytes—angioblastoma (Nakagawa)

Two babies were found to have large hemangiomas. Histologically there were many islands of compactly packed mesenchymal cells in the deep dermis and subcutaneous tissue. Electron microscopically there was proliferation of immature endothelial cells and pericytes. Characteristic crystalline lamellae were in the endothelial cells. Our two cases seemed to be an independent entity from other benign angiomas because of the distinct clinical, histologic, and ultrastructural features. The suggested diagnosis was angioblastoma (Nakagawa; Miki and Matsumoto), hypertrophic hemangioma (Watson and McCarthy), and benign hemangioendothelioma (Stout).

The extensibility in human skin: variation according to age and site.

Normal skin extensibility in the living body of 94 healthy male subjects ranging in age from 3 months to 73 years was determined quantitatively with the Bio-Skin Tension Meter at 12 sites. In comparison with the age of 20-29 years, the skin extensibility, particularly in the age group of less than 2 years, was significantly high. However, no significant difference from the age groups of 12-14, 15-19, 30-49 and over 50 years was found at any site. Correlation by age was noted at the extremities, excluding the posterior upper arm and at the lower abdomen, with the extensibility of the group less than 1 year as the maximum value, decreasing gradually down to 3-5 or 6-8 years. At the cheek, shoulder, anterior chest, and posterior upper arm, however, no correlation with age was noted.

Facial Reconstruction with Free-Tissue Transfer

The article provides a retrospective review of 25 free-tissue transfers for facial reconstruction on 24 recipient sites in 21 patients. The recipient sites of the face were classified into frontal (4 patients), orbital (2 patients), nasal (2 patients), buccal (11 patients), and oral region (5 patients). The transferred flaps included 16 fasciocutaneous flaps (6 forearm flaps, 5 scapular flaps, 2 anteromedial thigh flaps, 1 lateral arm flap, 1 dorsalis pedis flap, and 1 deltopectoral flap) and 8 myocutaneous flaps (6 latissimus dorsi myocutaneous flaps, 1 serratus anterior myocutaneous flap, 1 rectus abdominis myocutaneous flap, and 1 prefabricated flap). Thinning modifications such as the expansion, reduction, or extension techniques were performed in the myocutaneous flap to avoid having a bulky flap. In our view, the flap from the trunk matches the facial skin color better than that from the extremity. Satisfactory results were attained in all cases in which a complete replacement of the facial aesthetic unit was performed.