Development of a Janus tissue adhesive hemostatic patch based on hydrophobically-modified Alaska pollock gelatin.

Uncontrollable hemorrhage from trauma and open surgery leads to a high percentage of death. Even though some patch-type hemostatic materials have been used in the clinic, sufficient tissue adhesion property and the management of tissue adhesion and anti-adhesion have been the challenges. In this report, we designed Janus tissue adhesive hemostatic patch, consisting of Alaska pollock gelatin (Org-ApGltn) as a support layer and decanoyl group-modified ApGltn (C10-ApGltn) with pentaerythritol poly(ethylene glycol) ether tetrasuccinimidyl glutarate (4S-PEG) as an adhesive layer, named as the C10-ApGltn patch. The C10-ApGltn patch adhered onto blood vessel surface by the activation 4S-PEG and hydrophobic groups in C10-ApGltn through the covalent bond formation and physical interaction. The burst strength of the C10-ApGltn patch was optimized in terms of the degree of substitution, the molecular weight of 4S-PEG, the concentration of C10-ApGltn, and the NHS/NH2 ratio. The optimized C10-ApGltn patch showed significantly higher burst strength with commercially available TachoSil®. The C10-ApGltn patch showed enzymatic degradability in a buffer solution with collagenase. In a rat liver hemorrhage model, the C10-ApGltn patch acted as a sealant on the hemorrhage site and exhibited competitive hemostatic property to TachoSil®.

Effects of partial sleep restriction and subsequent daytime napping on prolonged exertional heat strain.

OBJECTIVES: It is considered that sleep restriction is one of the risk factors for the development of exertional heat stroke and illness. However, how sleep restriction affects exertional heat strain and the nature of the coping strategy involved in this phenomenon remain unclear. METHODS: Fourteen healthy subjects were studied on four occasions: after a night of normal sleep (NS, 7-8 h) and after a night of partial sleep restriction (PSR, 4 h), each with or without taking a daytime nap during the subsequent experimental day. The laboratory test consisted of two 40 min periods of moderate walking in a hot room in the morning and the afternoon. RESULTS: The increase in rectal temperature during walking was significantly greater in PSR than in NS in the afternoon. The rating scores for physical and psychological fatigue and sleepiness were significantly greater in PSR than in NS, both in the morning and in the afternoon. The reaction times and lapses in the psychomotor vigilance task (PVT) after walking were significantly worse in PSR than in NS in the morning and after lunch. The nap intervention attenuated significantly the scores for fatigue and sleepiness in PSR. Furthermore, the decreased PVT response in PSR was significantly reversed by the nap. CONCLUSIONS: These results suggest that PSR augments physiological and psychological strain and reduces vigilance in the heat. Taking a nap seemed to be effective in reducing psychological strain and inhibiting the decrease in vigilance.

Metabolic rate prediction in young and old men by heart rate, ambient temperature, weight and body fat percentage.

OBJECTIVES: An estimation of metabolic rate (MR) is needed to determine wet-bulb globe temperature (WBGT) reference values in order to reduce heat strain in physical workers. The aim of this study was to develop MR prediction equation for younger and older men in hot working environments. METHODS: We measured the MR and heart rate (HR) of both younger and older men at ambient temperatures (Ta) of 25, 30 and 35°C while they cycled on a bicycle ergometer at a workload of 30, 45 and 60% of maximal oxygen uptake (V̇O2max). Seven younger male university students aged 22.9 ± 0.7 (mean ± SD) years and seven older male workers aged 61.7 ± 2.2 (mean ± SD) years participated in this study. MR, HR and rectal temperature (Tre) were measured during the study. HR, ambient temperature (Ta), body weight (BW) and body fat percentage (BF) served as predictors of MR using multivariate analysis. To increase the MR prediction accuracy, the following three alternative predictors of HR were used: HRres, calculated as 100 × [(HR - resting HR) / (maximal HR - resting HR)]; HRnet, calculated as (HR - resting HR); and HRi, calculated as (HR / resting HR). RESULTS: The R(2) value indicated that the models with HRres or HRnet were more accurate than those with HRi or HR. Ta had a significantly positive correlation with MR in older men. BW had a significantly positive correlation with MR in both younger and older men, and BF had a significantly negative correlation with MR in both younger and older men. CONCLUSIONS: HRres or HRnet enabled more accurate MR prediction than HR. BW and BF would increase the accuracy of MR prediction.

Fan-precooling effect on heat strain while wearing protective clothing.

This study compared heat strain during walking while wearing impermeable protective suits between fan-precooling and nonprecooling conditions. Six males engaged in 60 min of walking at a moderate speed (∼2.5 km/h) in a hot environment (37 °C, 40% relative humidity). Fanning using a fan (4.5 m/s) and spraying water over the body before wearing the suits produced significantly lower rectal temperature before the walking (37.3 ± 0.1 °C vs. 37.0 ± 0.1 °C, P < 0.05). In addition, whilst walking, rectal temperature was significantly lower in the precooling condition (maximum difference: 0.4 °C at 15 min of walking; 38.0 ± 0.1 °C vs. 37.8 ± 0.1 °C at the end of walking, P < 0.05). Although skin temperature decreased during fanning, no difference was observed during walking. Heart rate was lower in the precooling condition during the early stages of walking. Thermal and fatigue perceptions whilst walking did not differ between the conditions. Body weight loss was significantly lower in the precooling condition. These results may indicate that fan precooling attenuates exertional heat strain while wearing impermeable protective clothing. The fan-cooling method is practical, convenient, and yields lower heat strain during prolonged moderate exertion.

Topographical relationship between the human lateral circumflex femral artery and saphenous nerve.

This study was performed to investigate causes of various types of topographical relationship between the lateral circumflex femoral artery (L) and the saphenous nerve (S). Femoral artery (F), deep femoral artery (P), L and S of 186 legs of 93 Japanese adult cadavers were submitted to anatomy. Further, the levels of origin of L in thigh were measured. L were classified into nine types by the origins of L and topographical relationship between L and S. The incidence of various types of L is different among researchers. Our findings proved that these differences were caused by the differences in evaluations of twig from ascending branch (AB) or descending branch (DB) of L. In cases of L originating from F, incidence of L positioned in front of S is significantly higher than L originating from P (p < 0.01). In cases of L originating from F, L positioned in front of S originates from F at the significantly more proximal level compared to L positioned posterior to S (p < 0.001). Furthermore, also in cases of L originating from P, L positioned in front of S originates from P at the significantly more proximal level compared to L positioned posterior to S (p < 0.001). It is supposed that the topographical relationship between L and S changes depending on the artery where L originates and the level of origin of L.

A morphological study on the human obturator externus muscle with reference to anomalous muscle and anomalous fasciculus originating from the obturator externus muscle.

To elucidate the essential nature of the human obturator externus muscle (OE), the gross anatomy of the anomalous muscle and anomalous fasciculus originating from this muscle as well as the posterior division of the obturator nerve (P) were examined in 73 thighs of 45 Japanese adult cadavers. The investigation of anomalous muscle and anomalous fasciculus was effected by observation of the supernumerary muscular branch and supernumerary muscular twig from the P. The anomalous muscle occurring between the adductor brevis muscle (AB) and adductor minimus muscle (AMi) (37/73 thighs; 50.7%) and the anomalous fasciculus fused to the posterior surface of the AMi (18/73 thighs; 24.7%) were detected. It was demonstrated by the course of the P and the suppling nerve, that the OE was divided into its superior fasciculus (or fasciculi) (SF) and main belly by the P, moreover the anomalous muscle originated from the former and the anomalous fasciculus from the latter. Presumably, in the process of ontogeny, the SF of the original OE retained its original morphology (23/73 thighs; 31.5%), a part of the SF was converted to anomalous muscle (27/73 thighs; 37.0%), the entire SF was converted to anomalous muscle (10/73 thighs; 13.7%), and the entire SF underwent retrogression and disappeared (13/73 thighs; 17.8%). The presence (50/73 thighs; 68.5%) or absence (23/73 thighs; 31.5%) of piercing of the OE by the P seemed to depend upon the circumstances surrounding the morphological change in the SF. The original OE was considered to occur as an OE pierced by the P not possessing any supernumerary muscular branch or twig. Actually, the original OE was confirmed to occur with a low frequency (15/73 thighs; 20.5%). It was inferred that the original OE readily underwent variation in the process of ontogeny due to the influence of the obturator nerve. The segmental composition of the obturator nerve was considered not to be involved in the morphological change in the OE.

Comparison of the prevalence of ventricular and supraventricular premature beats with 24-hour Holter electrocardiography between hypertensive and normotensive shift workers in a manufacturing company.

We conducted 24-hour Holter electrocardiography (ECG) among shift workers to assess whether there were differences in the prevalence of ventricular apd supraventricular premature beats between hypertensive (HT) and normotensive (NT) workers. Among the selected 24 male shift workers, 20 were fitted with 24-hour Holter ECG monitors. Nine workers were in the HT group and 11 the NT group. The prevalence of isolated supraventricular premature beats (SVPBs) and SVPB runs were higher in the HT group than in the NT group, but without statistical significance. The prevalence of ventricular premature beats (VPBs) was similar between groups. One worker in each group experienced > or = 720 VPBs per 24 hours, while the worker in the HT group was detected as having a short run of VPBs. The results suggested the necessity of a larger scale study to clarify an association between hypertension and arrhythmias using 24-hour Holter electrocardiography.