Possible factors contributing to the postmortem lung weight in fire fatalities

The aim of the present study was to examine the factors that contribute to the postmortem lung weight in acute fire fatalities (n=149) including those with lower (<60%) and higher (>60%) blood carboxyhemoglobin (COHb) levels (n=94 and 55, respectively). The control groups consisted of acute myocardial infarction/ischemia (AMI, n=99) and mechanical asphyxiation (n=85). For all cases (n=333), the lung and heart weights were independent of the postmortem time (4.5-72 h) and charring of the body. The combined weight of both lobes of the lung showed a significant gender difference (males>females, P<0.001), negative regression with respect to age (R=0.167, P<0.01) and positive regression with respect to heart weight (R=0.316, P<0.001). The gender difference was also significant for each cause of death even after being corrected using body height measurements. When the lung-heart weight ratio was estimated to diminish the influence of possible cardiogenic factors, the gender difference was insignificant for each cause of death among the non-elderly (<60 years of age). However, for elderly fire fatalities (>60 years of age), there was a gender difference (males>females) for the lower COHb group (P<0.05) and higher COHb group (P<0.001). A significant age-dependent difference (non-elderly>elderly) in the lung-heart weight ratio was observed for fire fatalities with a lower COHb and AMI among males and for fire fatalities with a higher COHb among females. Such gender- and/or age-dependent influences were not significant for fatal mechanical asphyxiation. These findings suggest that a person's heart weight may be a possible contributory factor to an increase in the lung weight in acute death, and that gender- and/or age-dependent susceptibilities may be additional factors that contribute to fire fatalities and AMI. In addition, elderly females appear to be most susceptible among fire casualties, and extreme cardiomegaly may also be a potential fatal risk factor.     

Methemoglobinemia induced by automobile exhaust fumes

Although methemoglobinemia is an uncommon disorder, it should always be considered in the differential diagnosis of cyanosis. Major causes of acquired methemoglobinemia are nitrates, aniline, and analgesics, though rare cases have been reported to have been caused by automobile exhaust fumes. A 24-year-old man had inhaled a large amount of automobile exhaust fumes, intending to commit suicide. He had become unconscious, with dilated pupils and symptoms of cyanosis. Arterial hemoglobin oxygen saturation (Sp_O2) was 86%, with a methemoglobin level of 44.3% and a carboxyhemoglobin level of 0%, while electrolytes, blood urea nitrogen, creatine, and glucose measurement results were normal. He was treated with methylene blue 250 mg (approximately 4 mg/kg) through a nasogastric tube. Four hours after the treatment, because the methemoglobin level was slightly above normal (2.2%), we added 180 mg of methylene blue. The results of final arterial blood gas analysis were a methemoglobin level of 0.4% and a carboxyhemoglobin level of 0.8%. He recovered uneventfully and returned home by himself the next day. To summarize, we successfully treated, with methylene blue given through a nasogastric tube, a young man who had developed severe methemoglobinemia from inhaling automobile exhaust fumes.     

Immunization with pseudorabies virus harboring Fc domain of IgG makes a contribution to protection of mice from lethal challenge

To enhance the efficacy of an inactivated vaccine against pseudorabies virus (PRV), we evaluated the adjuvant properties of Fc domain of IgG. A cell line expressing mouse IgG Fc chimera on its surface was established. We found that when PRV was propagated in the cells expressing the Fc chimera, PRV virion incorporated the Fc. Immunization of BALB/c mice with inactivated PRV harboring Fc, which had been propagated in the cells expressing Fc on its surface, induced higher antibody production against PRV and protected mice more effectively from lethal challenge of virulent strain, comparing to the immunization with normal inactivated virus. Virus harboring Fc has a great potential as a new inactivated vaccine.     

Hen's eggshell calcium

In Japan, insufficient calcium (Ca) intake is serious problem for health which may be associated with the high prevalence of osteoporosis among the aged. The intake of most nutrients has been sufficient, however, the Ca intake has never been sufficient. Eggshell Ca has as much as 38% of Ca and low phosphorus content. Eggshell Ca was more soluble than Ca carbonate and was as much as milk products. Eggshell Ca has been shown to exhibit higher absorptivity and availability than Ca carbonate. Furthermore, it has been reported that eggshell Ca is more effective in increasing bone mineral density in ovariectomized osteoporotic rats. These results suggest that eggshell Ca could be beneficial for bone and we propose Ca fortified foods which contain eggshell Ca as a nutraceutical.     

Single-channel properties of volume-sensitive Cl- channel in ClC-3-deficient cardiomyocytes

It is controversial whether the ClC-3 protein, which is one of the voltage-dependent chloride channel ClC family members, is a candidate for the volume-sensitive outwardly rectifying (VSOR) Cl(-) channel per se or its regulator. Here, for the first time, we examined the single-channel properties of the VSOR Cl(-) channel in ventricular myocytes isolated from ClC-3-deficient mice. The single-channel current induced by cell swelling exhibited Cl(-) selectivity, mild outward rectification, and an intermediate unitary conductance (around 38 pS). A Cl(-) channel blocker, 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS), reversibly inhibited the outward current. These single-channel properties were identical with those in ClC-3 expressing wild-type ventricular myocytes. These results indicate that the single-channel activity of the VSOR Cl(-) channel is independent of the expression of ClC-3 proteins in mouse ventricular myocytes.     

Dual Left Anterior Descending Coronary Artery: Report of a Case

We report a case of Type I dual left anterior descending artery (LAD) successfully treated by coronary artery bypass grafting including the long LAD. This rare coronary artery anomaly is of clinical importance in the field of myocardial revascularization.     

Regulatory volume increase after secretory volume decrease in colonic epithelial cells under muscarinic stimulation

To address the question of whether colonic secretory cells change their volume in response to carbachol (CCh) stimulation and, if so, the mechanisms involved therein, we used two-photon laser scanning microscopy to measure the volume of individual epithelial cells in the fundus region of crypts isolated from the guinea-pig distal colon. We also measured the volume of human colonic epithelial T84 cells using an electronic sizing technique. Both types of colonocytes responded to stimulation by CCh with shrinkage and then underwent a regulatory volume increase (RVI), even during continued stimulation by CCh. The secretory volume decrease (SVD) induced by CCh was antagonized by atropine, BAPTA loading and niflumic acid, a blocker of Ca²⁺-activated Cl^– channels. An increase in the intracellular free [Ca²⁺] was observed with fura-2 during these volume responses to CCh. Removal of all Na⁺ or K⁺ or of most of the Cl^– from the extracellular solution abolished the RVI, but not the preceding SVD. The RVI, but not the preceding SVD, was abolished by bumetanide, a blocker of the Na⁺-K⁺-2Cl^– cotransporter. We conclude that guinea-pig crypt colonocytes and human T84 cells exhibit a cytosolic Ca²⁺-dependent SVD and undergo a subsequent RVI that is dependent on the operation of Na⁺-K⁺-2Cl^– cotransporters.     

Dioxin health risk to infants using simulated tissue concentrations

Dioxin concentrations in infant and child were simulated using physiologically based pharmacokinetic (PBPK) models developed for these groups. The infant model was validated by comparing the simulated concentration with the measured concentration from the literature, and they showed good agreement. Simulations with our PBPK model showed temporal patterns in concentrations in various tissues. For risk assessment, estimated concentrations of 29 dioxins in the liver were summed up in a toxic equivalency (TEQ) basis to be compared with actual 2,3,7,8-TCDD concentrations in rat liver associated with toxicity. Maximum liver concentrations in breast-fed and formula-fed infants were 16.8pg TEQ/g and 3.5pg TEQ/g, respectively. The level in breast-fed infant liver was approximately 1/300 of the level associated with hepatocellular carcinoma and 1/5 of the level found in maternal rat liver associated with alterations in reproductive organs in the next generation. Based on our analysis, the present contamination level is not safe enough, but further dose-response data is required for a quantitative risk assessment.