Indoor environment and heatstroke risk

This paper describes the outline of heatstroke risk evaluation model for aged residents based on surveys done by the Heatstroke Surveillance Committee of Japanese Association for Acute Medicine and field measurements of indoor air temperature, humidity and so on. To reduce heatstroke of aged residents, promotion of thermal insulation, sun-shading, cross ventilation, air-condition of houses and living behavior of residents are needed.     

Balance of older trekkers: data on alpine accidents and performance as assessed using a video game machine

The number of alpine accidents involving older trekkers has increased markedly in developed countries in recent years. More than 76.8% of the trekkers involved in alpine accidents in Japan were older than 40 years, with some experiencing a stroke or myocardial infarction while trekking at altitude. In the present study, we surveyed social trends in trekkers by interview at a popular mountain site, Mt Tanigawa (1963 m in altitude). The total number of trekkers interviewed was 511, and more than 60% of these were older than 40 years. Of trekkers older than 60 years, 42% complained of conditions such as hypertension or diabetes. In 2 volunteer groups (10 younger subjects and 10 older subjects), physical condition was assessed before and after trekking. Significant body weight loss induced by dehydration was observed more often in older subjects than in younger subjects (P < .05). Balance, as measured using the Nintendo WiiFit (Nintendo, Kyoto, Japan), worsened in the older group (P < .05). Local police records for 2009 showed that the total number of alpine accidents was 65. Injuries provoked by stumbling, slipping, and falling accounted for 51% of these, and 82% of casualties were older than 40 years, with 35% being older than 60 years. In conclusion, many older people involved in nonchallenging middle-altitude trekking have problems with regard to overall health and balance. Alpine accidents caused by myocardial infarction, stroke, or hypoglycemia tend to be more common in this population. Alpine rescue teams should be well prepared for this, and older trekkers should be made aware of their increased risk of injury in alpine settings.     

Antimicrobial-susceptible patterns of <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> isolated from surgical infections: a new approach

Our goal was to analyze minimum inhibitory concentration (MIC) data for Staphylococcus aureus isolated from surgical infections (SIs) and to look for correlations among the clinically available antimicrobials that were tested. Clinical isolates from SIs were collected by a multicenter surveillance group involving 34 institutions in Japan. During the period April 1998 to March 2007, 312 strains of S. aureus [71 methicillin susceptible (MSSA) and 241 methicillin resistant (MRSA)] were consecutively obtained from these institutions. MIC data for 18 clinically available antimicrobial agents [ABPC, CEZ, CTM, CMX, CPR, FMOX, CFPM, CZOP, IPM, MEMP, GM, ABK, MINO, CLDM, FOM, LVFX, VCM, and TEIC (abbreviations defined in Tables 2 and 3)] against these isolates was analyzed using a principal component analysis (PCA). PCA revealed that four principal components explained 71.1% of the total variance. The first component consisted of major contributions from MEPM and IPM. The second component consisted of major contributions from MINO. These two-first axes, which were strong and explained 54.2% of the total variance, were able to classify the clinical isolates into four clusters. Furthermore, the proportion of the four clusters provided the characteristics of the S. aureus that were clinically isolated at each institute. PCA is a clinically applicable method for analyzing MIC patterns. Such analyses might contribute to the establishment of a practical classification of antimicrobial agents and to the identification of the characteristic antimicrobial resistance patterns at each institute.     

PDGFRalpha-positive cells in bone marrow are mobilized by high mobility group box 1 (HMGB1) to regenerate injured epithelia

The role of bone marrow cells in repairing ectodermal tissue, such as skin epidermis, is not clear. To explore this process further, this study examined a particular form of cutaneous repair, skin grafting. Grafting of full thickness wild-type mouse skin onto mice that had received a green fluorescent protein-bone marrow transplant after whole body irradiation led to an abundance of bone marrow-derived epithelial cells in follicular and interfollicular epidermis that persisted for at least 5 mo. The source of the epithelial progenitors was the nonhematopoietic, platelet-derived growth factor receptor α-positive (Lin(-)/PDGFRα(+)) bone marrow cell population. Skin grafts release high mobility group box 1 (HMGB1) in vitro and in vivo, which can mobilize the Lin(-)/PDGFRα(+) cells from bone marrow to target the engrafted skin. These data provide unique insight into how skin grafts facilitate tissue repair and identify strategies germane to regenerative medicine for skin and, perhaps, other ectodermal defects or diseases.     

Acrosome-reacted mouse spermatozoa recovered from the perivitelline space can fertilize other eggs

Many investigators maintain that spermatozoa that have initiated the acrosome reaction (AR) before reaching the surface of the egg's zona pellucida (ZP) are unable to bind and penetrate the ZP. A recent study has revealed that most fertilizing mouse spermatozoa initiate the AR before contacting the ZP. We found that acrosome-reacted spermatozoa collected from the perivitelline space of Cd9-null mice (whose egg plasma membranes are incapable of fusing with spermatozoa) were able to pass through both the cumulus and ZP of WT mouse eggs and produced live offspring. This means that the spermatozoa we used had the ability to pass through the ZP at least twice. Apparently, some spermatozoa that had undergone the AR long before contact with the ZP remained capable of crossing the ZP and fertilizing eggs. Thus, the concept that acrosome-reacted spermatozoa are unable to bind to the ZP and have lost their fertilizing capacity must be reconsidered.     

A case of pneumatosis cystoides intestinalis induced by steroid pulse therapy for severe acute hepatitis B

A 26-year-old Japanese woman was admitted to the hospital because of fever and general fatigue. A diagnosis of acute hepatitis B was given because of high levels of transaminase and positivity for HBs-Ag, HBe-Ag and HBc-IgM. On the 2nd day progression to fulminant hepatitis was suspected, and steroid pulse therapy, cyclosporin, entecavir, and interferon-β were started. Her laboratory data improved until transaminase showed an increase on 18th day, and steroid was once again administered. Abdominal CT scan and plain abdominal X-ray showed pneumatosis cystoides intestinalis (PCI) mainly along the ascending colon without any symptoms. After discontinuation of steroid therapy, abnormal gas gradually disappeared. This is a very rare case of PCI, which may have been caused by short-term steroid pulse therapy.