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.     

Hemostatic effects of fibrinogen gamma-chain dodecapeptide-conjugated polymerized albumin particles in vitro and in vivo

BACKGROUND: Prototypes of platelet (PLT) substitutes have been studied and the focus was on a dodecapeptide, HHLGGAKQAGDV (H12), which is a fibrinogen gamma-chain carboxy-terminal sequence (gamma 400-411) and exists only in the fibrinogen domain. STUDY DESIGN AND METHODS: H12 was conjugated to the surface of polymerized albumin particles (polyAlb) as biocompatible and biodegradable particles with a mean diameter of 260 +/- 60 nm, and the hemostatic ability of H12-conjugated polyAlb (H12-polyAlb) under flow conditions and thrombocytopenic rats have been studied. RESULTS: H12-polyAlb enhanced the in vitro thrombus formation of activated PLTs on a collagen-immobilized plate when exposed to the flowing thrombocytopenic imitation blood. Furthermore, the analysis of the tail bleeding time of rats that were made thrombocytopenic by busulfan injection showed that H12-polyAlb had a hemostatic effect. Based on the bleeding time and the amount injected, the hemostatic capacity of 20 H12-polyAlb was estimated to correspond to that of one PLT. CONCLUSION: These results were important first steps toward the development of PLT substitutes and indicated that H12-polyAlb may be a suitable candidate for an alternative to human PLT concentrates transfused into thrombocytopenic patients in the future.     

Denervation and Reinnervation of the Heart After Aortic Surgery,Estimated by <Superscript>123</Superscript>I-Metaiodobenzylguanidine Scintigraphy

Purpose To investigate whether sympathetic nerve injury occurs during aortic surgery and how reinnervation takes place afterward.Methods Imaging with ¹²³I-metaiodobenzylguanidine (MIBG) was performed in 12 patients (aortic group) who underwent aortic surgery (ascending replacement 3, ascending-arch replacement 9) before and 3 weeks after surgery. In 8 of 12 patients, MIBG scintigraphy was performed 1 and 2 years after surgery. Twelve patients (control group) who underwent open-heart surgery (mitral valve repair: 11; tricuspid valve replacement: 1) were studied using MIBG scintigraphy. The heart-to-mediastinum (H/M) activity ratio was obtained from planar images. The myocardial single-photon-emission computed tomography image was divided into five segments and the regional tracer uptake was scored from 0 = absent to 3 = normal uptake.Results No significant difference in the H/M ratio in either early and delayed planar scans was observed between both groups before surgery. The H/M ratios significantly decreased 3 weeks after surgery in the aortic group, whereas there was no significant change in the control group. The H/M ratio did not recover to the preoperative level within 2 years. In these 8 patients, the regional uptake of MIBG improved in the anterior and septal regions 1 year after surgery.Conclusion During ascending or ascending-arch replacement, the sympathetic nerve was globally denervated and slight reinnervation was observed within 2 years. The anterior and septal regions showed a rapid reinnervation, whereas other regions did not.     

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.     

Detection of lipopolysaccharide in hemoglobin-vesicles by Limulus amebocyte lysate test with kinetic-turbidimetric gel clotting analysis and pretreatment of surfactant

A method to quantitatively measure the bacterial endotoxin content (lipopolysaccharide, LPS) in phospholipid vesicles or liposomes is necessary because the conventional Limulus amebocyte lysate (LAL) test does not provide an accurate measurement due to the hydrophobic interaction of LPS and vesicles that shields the activity of LPS to clot the LAL coagulant. This interference was evident from isothermal titration calorimetry results in our study that clearly demonstrated the insertion of the LPS molecule into the phospholipid bilayer membrane. Hemoglobin-vesicles (HbVs; particle diameter = 251 +/- 80 nm; [Hb] = 10 g/dL) are artificial oxygen carriers encapsulating a conc. Hb solution in phospholipid vesicles, and their oxygen transporting ability has been extensively studied. To accurately measure the LPS content in the HbV suspension, we tested the solubilization of HbV with deca(oxyethylene) dodecyl ether (C(12)E(10)), used to release the LPS entrapped in the vesicles, as a pretreatment for the succeeding LAL assay of the kinetic-turbidimetric gel clotting (detecting wavelength, 660 nm). The C(12)E(10) surfactant interferes with the gel clotting in a concentration-dependent manner, and the optimal condition was determined in terms of minimizing the dilution factor and C(12)E(10) concentration. We clarified the condition that allowed the measurement of LPS at >0.1 endotoxin units (EU)/mL in the HbV suspension. Moreover, the utilization of histidine-immobilized agarose gel effectively concentrated the trace amount of LPS from the C(12)E(10)-solubilized HbV solution and washed out C(12)E(10) as an inhibitory element. The LAL assay with the LPS-adsorbed gel resulted in the detection limit of 0.0025 EU/mL. Pretreatment with C(12)E(10) would be applicable not only to HbVs but also to other drug delivery systems using phospholipid vesicles encapsulating or incorporating functional molecules.