Active Range of Motion Measurement System Using an Optical Sensor to Evaluate Hand Functions

Impairment of hand function greatly affects the independence of a human being. Proper assessment of hand function before and after any treatment for functional restoration is important to decide better treatment strategies. Despite traditional techniques of hand function evaluation, individual joint based assessment is vital to better track the details of the hand function. Current clinical assessments with goniometers are labour intensive, cumbersome and highly depend on the skill level of the practitioner. This study introduces an active range of motion (AROM) measurement system to measure individual range of motion of finger joints using an optical sensor. The proposed method is highly efficient, and the results demonstrated that the measurements are instant, repeatable and can successfully be employed in a clinical setup for patient evaluations.Clinical Relevance-Closely working with clinician to develop rehabilitation systems, we have identified that the assessment of patient hand functions is time consuming, and accuracy can be depended on the skill level of the practitioner in measuring joint range of motions (ROM). System introduced in this study can measure the joint AROMs instantly and independent of the practitioner's skill level and hence can provide a reliable, repeatable assessment of patient's hand function.

Special Issue on Robotics for Medical Applications

In recent years, the field of robots for medical applications has been expanding rapidly. Robots effectively augment their operators’ skills, enabling them to achieve accuracy and high precision during complex procedures. The use of robots improves the quality of life of patients and the quality of medical research. Therefore, the research and development of robots for medical applications will become more active in aging societies. This special issue focuses on the design and control of robots as well as integrated technologies for robots for medical applications. These include navigation, simulator, image guidance, training, and validation technologies for robots.

The special issue consists of 17 papers with various studies related to medical robots. There are 7 papers on assistant robots, including their passive and active controls, devices, and sensors. There are 10 papers related to minimally invasive surgery and neurosurgery involving robots, including papers on sensors, actuators, navigation, haptic display devices, the mechanical design of devices, and other topics. The editors are confident that this special issue will greatly contribute to further progress in robotics

We sincerely thank the authors for their fine contributions and the reviewers for their generous contributions of time and effort. We would also like to thank the Editorial Board of the Journal of Robotics and Mechatronics for their help with this special issue.

Compact Variable Stiffness Actuator for Surgical Robots

Highly rigid surgical robots are capable of precise positioning; however, there is a risk of injury to the surrounding organs owing to undesired contact. To solve this problem, surgeons can change their stiffness according to the desired motion by contracting and relaxing the muscles. Therefore, surgical robots that can change their stiffness according to their application, similar to a surgeon, are useful in improving safety. However, existing variable stiffness actuators cannot easily achieve a wide variable stiffness range while maintaining a small size and lightweight, which are critical factors for surgical robots. This study presents the design, fabrication, and evaluation of a variable stiffness actuator that is compact and provides a wide range of variable stiffness, with elastic elements arranged in a circumferential direction.

Surgical Robot for Intraluminal Access: An Ex Vivo Feasibility Study

Early-stage gastrointestinal cancer is often treated by endoscopic submucosal dissection (ESD) using a flexible endoscope. Compared with conventional percutaneous surgery, ESD is much less invasive and provides a high quality of life for the patient because it does not require a skin incision, and the organ is preserved. However, the operator must be highly skilled because ESD requires using a flexible endoscope with energy devices, which have limited degrees of freedom. To facilitate easier manipulation of these flexible devices, we developed a surgical robot comprising a flexible endoscope and two articulating instruments. The robotic system is based on a conventional flexible endoscope, and an extrapolated motor unit moves the endoscope in all its degrees of freedom. The instruments are thin enough to allow insertion of two instruments into the endoscope channel, and each instrument has a bending section that allows for up–down, right–left, and forward–backward motion. In this study, we performed an ex vivo feasibility evaluation using the proposed robotic system for ESD in a porcine stomach. The procedure was successfully performed by five novice operators without complications. Our findings demonstrated the feasibility of the proposed robotic system and, furthermore, suggest that even operators with limited experience can use this system to perform ESD.

Fully Wearable Actuated Soft Exoskeleton for Grasping Assistance in Everyday Activities

Worldwide, over 50 million people suffer from persistent hand impairments after stroke or spinal cord injury (SCI). This results in major loss of independence and quality of life. Robotic hand exoskeletons can compensate for lost motor function and assist in grasping tasks performed in everyday activities. Several recent prototypes can partially provide this assistance. However, it remains challenging to integrate the dexterity required for daily tasks in a safe and user-friendly design that is acceptable for daily use in subjects with neuromotor hand impairments. We present the design of RELab tenoexo; a fully wearable assistive soft hand exoskeleton for daily activities. We present sleek mechanisms for a hand module that generates the four most frequently used grasp types, employing a remote actuation system that reduces weight on the hand. For optimal assistance and highest adaptability, we present various design and control options to customize the modular device, along with an automated tailoring algorithm that allows automatically generated hand modules for individual users. Mechanical evaluation shows that RELab tenoexo covers the range of motion and the fingertip forces required to assist users in up to 80% of all grasping activities. In user tests, we find that the low weight, unintrusive size, high wearing comfort, and appealing appearance are beneficial for user acceptance and usability in daily life. Finally, we demonstrate that RELab tenoexo leads to an immediate improvement of the functional grasping ability in a subject with SCI.

Spherical and Non-Spherical Combined Two Degree-of-Freedom Rotational Parallel Mechanism for a Microsurgical Robotic System

Microsurgery, often performed for anastomosis of small vessels and nerves, requires micro-manipulations of small tissues and thus requires highly specialized surgical skills. Robotic technology has great potential to assist with microsurgical treatments because of the high accuracy provided by robots; however, implementation remains challenging because the technical requirements of robotic surgery are far different from those in industry. One of the greatest challenges is that two surgical tools (e.g., tweezers) must be precisely and deftly moved around the surgical area in seven degrees of freedom (DOF) using one DOF to grasp each tool, and these tools are used in close proximity to each other. Additionally, high accuracy and rigidity at the tool tip are imperative for successful performance of the microsurgical procedure. In this study, we propose a new rotational two-DOF parallel mechanism that has the inherent advantages of a parallel mechanism, namely accuracy and rigidity, within a newly proposed spherical and non-spherical combined parallel structure to prevent collision of the two mechanisms in a dual-arm setup for microsurgery. The prototype was evaluated by performing a series of mechanical tests, and microsurgical suturing was performed by a microsurgical robotic system. The series of evaluations demonstrated the feasibility of the proposed mechanism.

A multichannel-near-infrared-spectroscopy-triggered robotic hand rehabilitation system for stroke patients

There is a demand for a new neurorehabilitation modality with a brain-computer interface for stroke patients with insufficient or no remaining hand motor function. We previously developed a robotic hand rehabilitation system triggered by multichannel near-infrared spectroscopy (NIRS) to address this demand. In a preliminary prototype system, a robotic hand orthosis, providing one degree-of-freedom motion for a hand's closing and opening, is triggered by a wireless command from a NIRS system, capturing a subject's motor cortex activation. To examine the feasibility of the prototype, we conducted a preliminary test involving six neurologically intact participants. The test comprised a series of evaluations for two aspects of neurorehabilitation training in a real-time manner: classification accuracy and execution time. The effects of classification-related factors, namely the algorithm, signal type, and number of NIRS channels, were investigated. In the comparison of algorithms, linear discrimination analysis performed better than the support vector machine in terms of both accuracy and training time. The oxyhemoglobin versus deoxyhemoglobin comparison revealed that the two concentrations almost equally contribute to the hand motion estimation. The relationship between the number of NIRS channels and accuracy indicated that a certain number of channels are needed and suggested a need for a method of selecting informative channels. The computation time of 5.84 ms was acceptable for our purpose. Overall, the preliminary prototype showed sufficient feasibility for further development and clinical testing with stroke patients.

Improving the strength of sutureless laser-assisted vessel repair using preloaded longitudinal compression on tissue edge

BACKGROUND AND OBJECTIVE

Little is known about the approximation of coapted edges in sutureless laser-assisted vessel welding. Tissue shrinkage by laser irradiation may cause coapted edges to separate, reducing strength of welding. This may be avoided by preloaded longitudinal compression on the tissue edges to be welded. This study compared welding strength with and without preloaded compression in ex vivo animal experiments.

MATERIALS AND METHODS

This study evaluated 24 samples of harvested porcine carotid arteries, each having a length of 3 cm and an inner diameter of 1.0-2.0 mm. A half circumferential incision was made at the center of each sample. A steel shaft 2.0 mm in diameter was inserted into each sample to approximate the incised edges. The samples were longitudinally compressed to 6 mm. Incision sites were repaired by irradiation with a 970-nm diode laser. No glue or die was used. The repair strength was evaluated by measuring the bursting point (BP) of all samples. In a pilot study, the welding conditions, including power, duration, and interval of the laser spots, were tested by trial and error in 18 samples, including six treated under optimum conditions. As a control group, six samples were welded under optimum conditions, but without compression.

RESULTS

Optimum conditions, consisting of 2.4 W power, 30-second duration, and 1-mm intervals of laser spots, yielded the highest BP (623 ± 236 mmHg), which was significantly higher than in the control group without compression (204 ± 208 mmHg, P = 0.009). Defining BP > 400 mmHg as successful repair, the success rates in the compression and control groups were 83% and 17%, respectively.

CONCLUSION

Preloaded longitudinal compression on the coapted edges may be important for sutureless laser-assisted vessel repair and anastomosis and may affect the strength of welding. Lasers Surg. Med. 49:533-538, 2017. © 2017 Wiley Periodicals, Inc.

A Microsurgical Robotic System that Induces a Multisensory Illusion

Intuitiveness in robotic surgery is highly desirable when performing highly elaborate surgical tasks using surgical master–slave systems (MSSs), such as suturing. To increase the operability of such systems, the time delay of the system response, haptic feedback, and eye–hand coordination are the issues that have received the most attention. In addition to these approaches, we propose a surgical robotic system that induces a multisensory illusion. In our previous study, we reported that a robotic instrument we devised enhances the multisensory illusion. In this paper, we determine the requirements for inducing this multisensory illusion in a multi-degree-of-freedom (DOF) MSS, and the first stage of prototype implementation based on the given requirements is described.

Next-generation robotic surgery--from the aspect of surgical robots developed by industry

At present, much of the research conducted worldwide focuses on extending the ability of surgical robots. One approach is to extend robotic dexterity. For instance, accessibility and dexterity of the surgical instruments remains the largest issue for reduced port surgery such as single port surgery or natural orifice surgery. To solve this problem, a great deal of research is currently conducted in the field of robotics. Enhancing the surgeon's perception is an approach that uses advanced sensor technology. The real-time data acquired through the robotic system combined with the data stored in the robot (such as the robot's location) provide a major advantage. This paper aims at introducing state-of-the-art products and pre-market products in this technological advancement, namely the robotic challenge in extending dexterity and hopefully providing the path to robotic surgery in the near future.

Gastric endoscopic submucosal dissection using novel 2.6-mm articulating devices: an ex vivo comparative and in vivo feasibility study

BACKGROUND AND STUDY AIMS

The conventional procedure of endoscopic submucosal dissection (ESD) is technically demanding. This study investigated the efficiency of novel articulating devices (maximum diameter 2.6 mm), which can be used with commercially available, standard endoscopes.

PATIENTS AND METHODS

In an ex vivo comparative study, eight endoscopists were divided into novices and experienced operators, and performed ESD using new devices and the conventional setup. An in vivo animal experiment was performed by two experts. Procedure times for incision and dissection were recorded, and unit times for circumferential length and area of specimens were calculated.

RESULTS

All procedures were successfully completed with en bloc resection. In the ex vivo study, the unit procedure times for incision and dissection by novices were significantly shorter using the new system (P < 0.01 and P < 0.05), whereas there was no significant difference for experienced endoscopists. Perforation occurred during one procedure in which the new system was used. The in vivo experiments were successfully completed without adverse events.

CONCLUSIONS

ESD using novel articulating devices was feasible. These devices were able to reduce the procedure time for novices.

Energy-Saving High-Speed Pick-and-Place Robot Using In-Frame Parallel Spring

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Concept prototype</div> Robotic instruments have recently been widely introduced into industrial automation. As energy supply and demand have become global issues, energy saving in industrial robots has become urgent. In general industrial pick-and-place robots, servomotors periodically repeat acceleration and deceleration, consequently lose much energy in motion. We propose a mechanism using an in-frame parallel spring for the pick-and-place robot. During motion, spring blades deform and store energy, then release it as energy of motion, enabling the mechanism to recycle energy that have been lost in conventional mechanisms. In this paper, a 1 DOF proof-of-concept prototype and preliminary feasibility tests are described. In this study, we applied in-frame parallel springs to a mechanism for pick-and-place robot. The parallel springs are fabricated from spring steel SK85M (Young’s modulus: 210 GPa) with 252 mm long, 50 mm wide and 0.3 mm thick. The results suggest that the prototype can achieve a repeated motion with the range of ±145.7 mm in 2.56 Hz by 1.17 W, greatly reduced from that of the the traditional mechanisms. In addition, it is desired to stop the robot immediately in regular motion if anomalies occurred in industrial applications. The prototype showed that an immediate stop in 0.6 s was feasible by dissipating elastic energy stored in spring blades, confirming the feasibility of our proposed mechanism.

Robotically enhanced rubber hand illusion

The rubber hand illusion is a well-known multisensory illusion. In brief, watching a rubber hand being stroked by a paintbrush while one's own unseen hand is synchronously stroked causes the rubber hand to be attributed to one's own body and to "feel like it's my hand." The rubber hand illusion is thought to be triggered by the synchronized tactile stimulation of both the subject's hand and the fake hand. To extend the conventional rubber hand illusion, we introduce robotic technology in the form of a master-slave telemanipulator. The developed one degree-of-freedom master-slave system consists of an exoskeleton master equipped with an optical encoder that is worn on the subject's index finger and a motor-actuated index finger on the rubber hand, which allows the subject to perform unilateral telemanipulation. The moving rubber hand illusion has been studied by several researchers in the past with mechanically connected rigs between the subject's body and the fake limb. The robotic instruments let us investigate the moving rubber hand illusion with less constraints, thus behaving closer to the classic rubber hand illusion. In addition, the temporal delay between the body and the fake limb can be precisely manipulated. The experimental results revealed that the robotic instruments significantly enhance the rubber hand illusion. The time delay is significantly correlated with the effect of the multisensory illusion, and the effect significantly decreased at time delays over 100 ms. These findings can potentially contribute to the investigations of neural mechanisms in the field of neuroscience and of master-slave systems in the field of robotics.

OpenIGTLink: an open network protocol for image-guided therapy environment

BACKGROUND

With increasing research on system integration for image-guided therapy (IGT), there has been a strong demand for standardized communication among devices and software to share data such as target positions, images and device status.

METHOD

We propose a new, open, simple and extensible network communication protocol for IGT, named OpenIGTLink, to transfer transform, image and status messages. We conducted performance tests and use-case evaluations in five clinical and engineering scenarios.

RESULTS

The protocol was able to transfer position data with submillisecond latency up to 1024 fps and images with latency of <10 ms at 32 fps. The use-case tests demonstrated that the protocol is feasible for integrating devices and software.

CONCLUSION

The protocol proved capable of handling data required in the IGT setting with sufficient time resolution and latency. The protocol not only improves the interoperability of devices and software but also promotes transitions of research prototypes to clinical applications.

Open core control software for surgical robots

OBJECT

In these days, patients and doctors in operation room are surrounded by many medical devices as resulting from recent advancement of medical technology. However, these cutting-edge medical devices are working independently and not collaborating with each other, even though the collaborations between these devices such as navigation systems and medical imaging devices are becoming very important for accomplishing complex surgical tasks (such as a tumor removal procedure while checking the tumor location in neurosurgery). On the other hand, several surgical robots have been commercialized, and are becoming common. However, these surgical robots are not open for collaborations with external medical devices in these days. A cutting-edge "intelligent surgical robot" will be possible in collaborating with surgical robots, various kinds of sensors, navigation system and so on. On the other hand, most of the academic software developments for surgical robots are "home-made" in their research institutions and not open to the public. Therefore, open source control software for surgical robots can be beneficial in this field. From these perspectives, we developed Open Core Control software for surgical robots to overcome these challenges.

MATERIALS AND METHODS

In general, control softwares have hardware dependencies based on actuators, sensors and various kinds of internal devices. Therefore, these control softwares cannot be used on different types of robots without modifications. However, the structure of the Open Core Control software can be reused for various types of robots by abstracting hardware dependent parts. In addition, network connectivity is crucial for collaboration between advanced medical devices. The OpenIGTLink is adopted in Interface class which plays a role to communicate with external medical devices. At the same time, it is essential to maintain the stable operation within the asynchronous data transactions through network. In the Open Core Control software, several techniques for this purpose were introduced. Virtual fixture is well known technique as a "force guide" for supporting operators to perform precise manipulation by using a master-slave robot. The virtual fixture for precise and safety surgery was implemented on the system to demonstrate an idea of high-level collaboration between a surgical robot and a navigation system. The extension of virtual fixture is not a part of the Open Core Control system, however, the function such as virtual fixture cannot be realized without a tight collaboration between cutting-edge medical devices. By using the virtual fixture, operators can pre-define an accessible area on the navigation system, and the area information can be transferred to the robot. In this manner, the surgical console generates the reflection force when the operator tries to get out from the pre-defined accessible area during surgery.

RESULTS

The Open Core Control software was implemented on a surgical master-slave robot and stable operation was observed in a motion test. The tip of the surgical robot was displayed on a navigation system by connecting the surgical robot with a 3D position sensor through the OpenIGTLink. The accessible area was pre-defined before the operation, and the virtual fixture was displayed as a "force guide" on the surgical console. In addition, the system showed stable performance in a duration test with network disturbance.

CONCLUSION

In this paper, a design of the Open Core Control software for surgical robots and the implementation of virtual fixture were described. The Open Core Control software was implemented on a surgical robot system and showed stable performance in high-level collaboration works. The Open Core Control software is developed to be a widely used platform of surgical robots. Safety issues are essential for control software of these complex medical devices. It is important to follow the global specifications such as a FDA requirement "General Principles of Software Validation" or IEC62304. For following these regulations, it is important to develop a self-test environment. Therefore, a test environment is now under development to test various interference in operation room such as a noise of electric knife by considering safety and test environment regulations such as ISO13849 and IEC60508. The Open Core Control software is currently being developed software in open-source manner and available on the Internet. A communization of software interface is becoming a major trend in this field. Based on this perspective, the Open Core Control software can be expected to bring contributions in this field.

Replantation of multi-level fingertip amputation using the pocket principle (palmar pocket method)

Two cases of multi-level fingertip amputation are presented. In each case, replantation was achieved in a two-stage procedure, involving reattachment, de-epithelialisation and insertion into a palmar pocket in stage 1, followed by removal from the palmar pocket 16 days later. The cases are described and the technique is discussed.

Amicrobial pustular dermatosis in two patients with immunological abnormalities

We report two patients with severe amicrobial pustular dermatosis with immunological abnormalities: a 63-year-old woman with a 30-year-history of discoid lupus erythematosus and sicca syndrome, and a 35-year-old woman with high levels of gamma-globulinemia and positive antinuclear antibodies. Both patients presented with crusty and eroded erythematous plaques studded with aseptic pustules on the back, face, and scalp. Histological examination showed acanthosis, neutrophilic exocytosis to the epidermis, and neutrophilic and lymphocytic infiltration with nuclear dust in the dermis. These patients were diagnosed as having "amicrobial pustulosis associated with autoimmune diseases". The eruptions improved with combination treatment of oral prednisolone with cyclosporin A or diaminodiphenylsulphone. Although the pathogenesis remains unclear, amicrobial pustular dermatosis might be one of the cutaneous complications in autoimmune diseases.

Numerical, morphological and phenotypic changes in Langerhans cells in the course of murine graft-versus-host disease

BACKGROUND

In the course of graft-versus-host disease (GVHD) or diseases that histologically mimic GVHD (e.g. toxic epidermal necrolysis, Stevens-Johnson syndrome), it is known that epidermal Langerhans cells (LCs) are depleted from the epidermis. However, the mechanism and significance of LC depletion is not well known.

OBJECTIVES

To investigate the numerical, morphological and phenotypic changes in LCs and apoptosis of LCs in the course of GVHD using a non-irradiated mouse GVHD model.

METHODS

BALB/c nu/nu mice and C57BL/6 mice were used as recipients and donors, respectively. Recipient mice were injected with T-cell-enriched donor spleen cells. Skin samples were harvested at various times after the inoculation. The numerical and morphological changes were examined by an immunofluorescence study of epidermal sheets. Apoptosis was studied by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling method and flow cytometric analysis using annexin V. Phenotypic change was studied by flow cytometric analysis of epidermal cell suspensions. The mixed epidermal cell lymphocyte reaction (MELR) was performed to examine functional changes in the epidermal cells.

RESULTS

Five days after inoculation, a graft-versus-host reaction occurred. Epidermal LCs began to decrease from the sixth day. On the fifth day, the LCs became larger and had prominent dendrites. Immediately before the LCs began to decrease, many LCs became round in shape, with scanty dendrites. LC apoptosis was not observed in the epidermis either on the fifth or seventh day. Phenotypically, the expression of CD40, CD80, CD86 and major histocompatibility complex class II antigen on the LCs was upregulated on the fifth and seventh day. Epidermal cells from GVHD mice showed an increased allostimulatory capacity in the secondary MELR.

CONCLUSIONS

These results suggest that at early GVHD onset, most LCs may not undergo apoptosis in the epidermis but are phenotypically activated, resulting in further activation of alloreactive T cells and aggravation of the disease.

Koebner phenomenon on skin graft donor site in cutaneous angiosarcoma

An 81-year-old woman developed a necrotic plaque and a surrounding purple-red, irregularly shaped macule on her scalp. The diagnosis of angiosarcoma was confirmed histologically. A wide surgical excision was made followed by a split-thickness skin graft from her right buttock. Nine months later, she noticed a dark purple-red lesion on the donor site which grew rapidly into a large mass. Histological examination revealed irregular clefts and vascular channels lined by atypical endothelial cells. Lung metastasis and pneumothorax were also noted. The secondary tumor appeared to represent Koebner phenomenon in a patient with angiosarcoma of the scalp.

A combination of roxithromycin and imipenem as an antimicrobial strategy against biofilms formed by Staphylococcus aureus

We examined the effects of a combination of roxithromycin and imipenem on a biofilm model of Staphylococcus aureus. Treatment with roxithromycin alone and imipenem alone did not decrease the number of viable bacterial cells compared with the control. However, a combination treatment of roxithromycin and imipenem significantly decreased the number of viable bacterial cells on day 8 after inoculation in the in vivo model (P < 0.01). On days 5 and 8 after inoculation, numerous polymorphonuclear leucocytes and macrophages invaded the bacterial clusters in the roxithromycin- and roxithromycin/imipenem-treated groups, but did not invade the control or imipenem-treated groups. The present study indicated that a combination of roxithromycin and imipenem is a potentially effective treatment for S. aureus biofilm-associated skin infections as it can induce the invasion of polymorphonuclear leucocytes into the biofilm.

The palmar pocket method: an adjunct to the management of zone I and II fingertip amputations

In 1979 Brent reported a new replantation method, without vascular anastomosis, that used a subcutaneous pocket. Brent chose the contralateral chest wall as a pocket site, but in other clinical reports, the abdominal wall was used. For both sites there were complications such as stiffness in the wrist, elbow, and shoulder joints and anxiety about pulling out the pocketed finger. To overcome these problems, we chose the ipsilateral palm and named this method the palmar pocket method. We used this method in 16 cases in which a digit other than the thumb had been amputated between the tip and lunula. In 13 cases the method was completely successful, and in 3 cases there was a small area of tip necrosis. The palmar pocket method is a simple and reliable operation for fingertip reattachment and more comfortable for patients than pocketing in the chest wall or abdominal wall.

Thyroid gland tumour, pemphigus foliaceus and myasthenia gravis in the daughter of a woman with myasthenia gravis

We describe a rare case of pemphigus foliaceus associated with familial myasthenia gravis (MG). A 35-year-old woman developed MG during oral corticosteroid treatment for pemphigus foliaceus. She had been operated on for a thyroid gland tumour that was confirmed histopathologically to be papillary carcinoma without metastasis. At the time of treatment, her mother had had MG for 30 years and undergone thymectomy 22 years ago. A specific ELISA technique showed that antidesmoglein 1 antibody was present in the daughter. There are many reports of multiple diseases such as pemphigus, thymoma, malignancy, and other autoimmune diseases associated with MG. However, familial MG following pemphigus foliaceus has not been reported previously.

Allergic contact dermatitis from a pyridine derivative in polyvinyl chloride leather

Antimicrobial coating of household products has gained wide acceptance in Japan in the past several years. Pyridine derivatives, used as antifungal or antibacterial agents in many common products, are known to cause contact dermatitis. We present a case of severe contact dermatitis caused by a pyridine derivative used as an antifungal agent in the polyvinyl chloride (PVC) leather of a chair. An open patch test was performed with each ingredient of the PVC leather. Other products were previously eliminated from consideration based on a series of negative patch tests. The PVC leather obtained from the patient's chair gave a ++ reaction with evident blistering, according to the International Contact Dermatitis Research Group standard. Fifteen ingredients of the PVC leather were open patch tested; a positive reaction was found with 2,3,5,6-tetrachloro-4 (methylsulphonyl) pyridine (1% in petrolatum). Clinicians should be aware that antifungal or antibacterial agents may be increasingly incorporated into common household products and should be suspected in cases of contact dermatitis.

Antimicrobial effects of acidic hot-spring water on Staphylococcus aureus strains isolated from atopic dermatitis patients

The present study examined the antimicrobial effects of acidic hot-spring water on Staphylococcus aureus strains isolated from atopic dermatitis (AD) patients. Plasma coagulation by S. aureus cells was not detected in plasma containing acidic hot-spring water (60%, pH 5.4) or hydrochloric acid (pH 5.0) after incubation for 24 h. S. aureus cells did not grow in Mueller-Hinton broth with acidic hot-spring water (50%, pH 4.4) after 24 h incubation. The colony counts of S. aureus cells in tryptic soy broth containing acidic hot-spring water (60%, pH 3.9) were over ten times lower than those in tryptic soy broth alone after incubation for 24 h (P<0.01). A membranous structure (an immature biofilm) was formed on the coverslips of tissue culture dishes by S. aureus cells in plasma after incubation for 24 h, although the colony counts of S. aureus cells in the immature biofilms in plasma containing acidic hot-spring water (60%, pH 5.4) were about eight times lower than those in plasma alone after incubation for 24 h (P<0.01). The colony counts of S. aureus cells that attached on coverslips in plasma containing acidic hot-spring water (60%, pH 5.4) or hydrochloric acid (pH 5.4) were over 1000 times lower than those in plasma alone after incubation for 24 h. These results suggest that 50% acidic hot-spring water has a bacteriostatic effect, 60% acidic hot-spring water has a moderate bactericidal effect against floating S. aureus cells and those cells in a biofilm, and, 60% acidic hot-spring water has an inhibitory effect on plasma coagulation and attachment of S. aureus cells. Furthermore, our present results suggest that a small amount of some ions in hot-spring water such as manganese and iodide ions are very important for a bactericidal activity of hot-spring water as well as the low pH condition.

The production of superantigenic exotoxins by coagulase-negative staphylococci isolated from human skin lesions

We examined the production of superantigenic exotoxins in 136 coagulase-negative staphylococci isolated from various skin lesions in humans using a reversed passive latex agglutination test (Denka Seiken). As a control we examined the same in 50 Staphylococcus aureus strains isolated from non-infective skin ulcers in humans. Of the 136 strains of coagulase negative-staphylococci, 9 (6.6%) produced one or more identifiable exotoxins. In contrast, 21 (42%) out of the 50 S. aureus strains produced one or more identifiable exotoxins (P<0.01).

The brain link protein-1 (BRAL1): cDNA cloning, genomic structure, and characterization as a novel link protein expressed in adult brain

We report here molecular cloning and expression analysis of the gene for a novel human brain link protein-1 (BRAL1) which is predominantly expressed in brain. The predicted open reading frame of human brain link protein-1 encoded a polypeptide of 340 amino acids containing three protein modules, the immunoglobulin-like fold and proteoglycan tandem repeat 1 and 2 domains, with an estimated mass of 38 kDa. The brain link protein-1 mRNA was exclusively present in brain. When analyzed during mouse development, it was detected solely in the adult brain. Concomitant expression pattern of mRNAs for brain link protein-1 and various lectican proteoglycans in brain suggests a possibility that brain link protein-1 functions to stabilize the binding between hyaluronan and brevican. The human BRAL1 gene contained 7 exons and spanned approximately 6 kb. The entire immunoglobulin-like fold was encoded by a single exon and the proteoglycan tandem repeat 1 and 2 domains were encoded by a single and two exons, respectively. The deduced amino acid sequence of human brain link protein-1 exhibited 45% identity with human cartilage link protein-1 (CRTL1), previously reported as link protein to stabilize aggregates of aggrecan and hyaluronan in cartilage. These results suggest that brain link protein-1 may have distinct function from cartilage link protein-1 and play specific roles, especially in the adult brain.

Adherence characteristics and susceptibility to antimicrobial agents of Staphylococcus aureus strains isolated from skin infections and atopic dermatitis

We examined the adherence characteristics and susceptibility to various antimicrobial agents of 130 strains of Staphylococcus aureus isolated from infective skin lesions and 135 strains of S. aureus isolated from non-infective eczematous lesions of atopic dermatitis (AD) patients. The isolation rate of methicillin-resistant S. aureus (MRSA) was 27.7% in strains from clinical sources excluding AD and 31.1% in those from AD. Coagulase type II strains were most frequently observed in MRSA strains isolated from all sources excluding AD, and coagulase type III strains were most frequently observed in those isolated from AD. We proposed that antimicrobial treatment for AD patients should be carefully designed to prevent MRSA infection. Plasma coagulation ability was lowest in S. aureus strains isolated from abscesses, suggesting that the lower production of fibrin observed in abscesses may assist the infiltration of neutrophils into skin tissues and that a decrease in plasma coagulation ability may enable abscess formation. Adherence to polypropylene tubes with slime production was most evident in S. aureus strains isolated from felon and least evident in those isolated from cellulitis and lymphangitis. Tube adherence was characteristic of the S. aureus strains attached to superficial skin tissues, but not necessarily for strains that had infiltrated the deep skin tissues. Fusidic acid demonstrated significant antimicrobial activity against the MRSA strains, but rifampicin was the strongest antimicrobial agent.

Linear IgA disease with IgA antibodies directed against 200- and 280-kDa epidermal antigens

We report an 80-year-old man with the lamina lucida type of linear IgA disease, with IgA autoantibodies reactive with 200-kDa and 280-kDa epidermal proteins. The patient presented with widespread bullous lesions on his trunk and extremities without mucosal involvement. Histopathology of lesional skin showed a subepidermal blister with papillary microabscesses of neutrophils and a few eosinophils. Direct immunofluorescence microscopy of perilesional skin showed linear deposits of IgA and C3 at the basement membrane zone. The patient's serum contained IgA autoantibodies that bound exclusively to the epidermal side of 1 mol L-1 NaCl split skin as determined by indirect immunofluorescence microscopy. Circulating IgA autoantibodies to 200- and 280-kDa antigens were detected in the patient's serum by immunoblot analysis using extracts from normal human epidermis and human epidermal keratinocytes. These two antibodies, eluted from individual nitrocellulose membranes, reacted with the epidermal side of 1 mol L-1 NaCl split skin on indirect immunofluorescence microscopy, and bound to hemidesmosomes as determined by immunoperoxidase electron microscopy. This observation suggests the presence of hitherto uncharacterized 200- and 280-kDa hemidesmosomal proteins distinct from BPAG1, BPAG2 and beta4 integrin as target antigens in linear IgA disease.

[Azithromycin in the field of dermatology]

Azithromycin (AZM) is a new macrolides antibiotic that has a 15-membered ring structure obtained by introducing methyl-substituted nitrogen into a 14-membered ring lactone of erythromycin(EM). This article reviewed and summarized the clinical studies in the treatment of skin and skin structure infections conducted in Japan and abroad of AZM.

Palmoplantar pustulosis with pustulotic arthroosteitis involving temporal osteomyelitis and meningitis

A 46-year-old man who had been suffering from palmoplantar pustulosis (PPP) for 3 years had anterior chest pain and left temporal pain from six months after the onset of his disease. A bone scan revealed abnormal uptake at the sternoclavicular joint and left temporal region. The head CT and MRI gave the diagnosis of temporal osteomyelitis with meningitis and myositis. His headache continued even after tonsillectomy and was effectively treated with cyclosporine A (3 mg/kg/day). Oral cyclosporine A was beneficial for the osteomyelitis and skin lesions. Sterile lytic bone lesions occurring most often at the sternocostoclavicular joint have been associated with PPP. However, there have been no reports of a PPP patient with temporal osteomyelytic involvement.

Expression pattern of the bcl-2 homologous protein bad in normal skin, psoriasis vulgaris and keratinocytic tumors

Previous investigations focused on the mechanisms and regulation of apoptotic process have found that bcl-2 and its homologous proteins are central regulators of the mitochondrial phase of apoptosis. Expression of several members of the bcl-2 family has been studied in various tissues including skin under normal as well as disease conditions. In this report, we investigated the expression of bad, the pro-apoptotic member of the BH3 subfamily, in normal and psoriatic epidermis, keratoacanthoma, and basal and squamous cell carcinomas. Normal and psoriatic epidermis showed accentuation of the staining in the lower suprabasal compartment. A weak, predominantly diffuse staining pattern was observed in the upper epidermis of psoriatic plaques. Keratoacanthoma showed strong but diffuse immunostaining for pro-apoptotic bad, however we found only weak bad expression in squamous cell carcinoma. Seven out of 15 basal cell carcinomas failed to express bad protein. There was no correlation between bad positivity and depth of tumour infiltration. Our observation suggests that the pro-apoptotic bad may function as one of regulators involved in the maintenance of epidermal homeostasis and this function could be altered depending on the disease state.

Calcium oxide and magnesium oxide inhibit plasma coagulation by Staphylococcus aureus cells at the lower concentration than zinc oxide

We examined the effect of ceramic powder slurries on the coagulation of plasma by Staphylococcus aureus cells. Plasma coagulation by S. aureus strains or their cultured supernatant was inhibited in the plasma with 0.12% calcium oxide or 0.25% magnesium oxide after incubation for 24 h at 37 degrees C. Inhibition of plasma coagulation by calcium oxide and magnesium oxide was observed at the lower concentration than zinc oxide.

Characteristics in adherence of streptococci and Staphylococcus aureus isolated from various infective skin lesions: serum IgA decreases adherence of Streptococcus pyogenes but not Staphylococcus aureus

We characterized adherence of streptococci and Staphylococcus aureus strains isolated from various infective skin lesions in terms of hydrophobicity, negative charge, tube adherence, slime production, and influence on adherence to coverslips by plasma and serum immunoglobulins. High hydrophobicity was more frequently observed in Streptococcus pyogenes strains than in Streptococcus agalactiae strains (P < 0.01) and S. aureus strains (P < 0.001) and slime production was more frequently observed in S. agalactiae strains than in S. pyogenes strains (P < 0.05). Serum IgA decreased adherence to coverslips of S. pyogenes strains but not that of S. aureus strains.

[Clinical evaluation of biapenem in various infectious diseases]

The clinical usefulness of injectable biapenem (BIPM) was examined for various infectious diseases in the fields of internal medicine, urology, surgery, orthopedics, obstetrics and gynecology, otorhinolaryngology, ophthalmology, dermatology, oral surgery, and plastic surgery. BIPM was administered by intravenous drip infusion at a dose of 150, 300, or 600 mg twice a day. The concentrations in various body fluid and tissues were also examined. 1. In the total enrollment of 256 cases, the numbers subjected to the analyses for clinical efficacy, bacteriological efficacy, side effects and abnormal laboratory findings were 214, 170, 252 and 251 cases, respectively. 2. The clinical efficacy rate was 85.5% (183/214 cases) as a whole, being 2/2 for sepsis, 6/8 for cellulitis and lymphangitis, 76.2% (16/21) for traumatic, operative wound and burn infections, 4/6 for osteomyelitis and arthritis, 92.9% (13/14) for peritonsillar abscess and peritonsillitis, 83.3% (15/18) for chronic lower respiratory tract infection, 7/7 for pneumonia, 83.3% (30/36) for complicated urinary tract infection, 100% (14/14) for cholecystitis and cholangitis, 88.2% (15/17) for peritonitis, 86.5% (32/37) for internal genital infection, 8/9 for pelvic peritonitis, 2/4 for corneal ulcer, orbital infection and panophthalmitis, 1/2 for otitis media, 4/4 for sinustitis, 93.3% (14/15) for osteitis of jaw and cellulitis of mouth floor. The efficacy rate in the poor responders to the pretreatment by other antibiotics was 86.4% (70/81). 3. 300 strains of causative organisms were isolated from 170 cases which contained polymicrobial infections. The elimination rate of causative organisms was 85.3% (256/300 strains), in terms of bacteriological efficacy. 4. Side effects were noted in 11 of 252 cases (4.4%) with 11 events. The signs and symptoms were the skin symptoms (5 cases), gastro-intestinal symptoms (3 cases), interstitial pneumonia (2 cases), and feeling bad (1 case), all of which disappeared during treatment or after the discontinuation of treatment. The abnormal laboratory findings were observed in 31 of 251 cases (12.4%) with 50 events, and major ones were an increase in eosinophils, and elevations of AST, ALT, gamma-GTP and Al-p. 5. The concentrations of BIPM in body fluid and tissues were determined in 46 cases (212 samples) most of which were administered 300 mg of BIPM by intravenous drip infusion for 60 minutes. The concentrations in the sputum within 6 hours after administration were 0.1-2.5 micrograms/g. The maximum concentrations in body fluid and tissues were 0.2-1.8 micrograms/g or ml in the bile, middle ear mucosa, tonsillar tissue, aqueous humor and bone tissues and were 2.0-5.7 micrograms/g or ml in the gallbladder, maxillary sinus mucous membrane, ethmoidal sinus mucous membrane, oral tissues, skin, woman genitals, synovia, joint tissue, and the eschar. The concentrations in the uterine arterial plasma and retroperitoneal fluid were almost similar to those in the cubitl vein plasma. From the above-mentioned results of clinical efficacy, bacteriological efficacy, and safety, injectable BIPM was confirmed to be useful in the treatment of moderate, severe and/or refractory infections in various fields.

Regulation of cyclooxygenase-2 by interferon gamma and transforming growth factor alpha in normal human epidermal keratinocytes and squamous carcinoma cells. Role of mitogen-activated protein kinases

Treatment of normal human epidermal keratinocytes (NHEK) with interferon-gamma (IFN-gamma) causes a 9-fold increase in the level of cyclooxygenase-2 (COX-2) mRNA expression. Nuclear run-off assays indicate that this induction is at least partly due to increased transcription. Activation of the epidermal growth factor receptor (EGFR) signaling pathway due to the enhanced transforming growth factor alpha (TGFalpha) expression plays an important role in the induction of COX-2 by IFN-gamma. This is supported by the ability of TGFalpha to rapidly induce COX-2 and the inhibition of the IFN-gamma-mediated COX-2 mRNA induction by an EGFR antibody and EGFR-selective kinase inhibitors. Deletion and mutation analysis indicates the importance of the proximal cAMP-response element/ATF site in the transcriptional control of this gene by TGFalpha. The increase in COX-2 mRNA by TGFalpha requires activation of both the extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) pathways. Inhibition of p38 MAPK decreases the stability of COX-2 mRNA, while inhibition of MAPK/ERK kinase (MEK) does not. These results suggest that the p38 MAPK signaling pathway controls COX-2 at the level of mRNA stability, while the ERK signaling pathway regulates COX-2 at the level of transcription. In contrast to NHEK, IFN-gamma and TGFalpha are not very effective in inducing TGFalpha or COX-2 expression in several squamous carcinoma cell lines, indicating alterations in both IFN-gamma and TGFalpha response pathways.