Urinary benzyl alcohol and hippuric acid in workers exposed to benzyl alcohol during paint stripping work.

OBJECTIVE: This research aimed to develop a reliable gas chromatography-mass spectrometry (GC-MS) method for detecting urinary benzyl alcohol (BeOH) concentrations and assess its suitability as a biomarker for occupational BeOH exposure. METHODS: Thirteen male participants exposed to BeOH during paint stripping work provided preshift and postshift urine samples, and their personal exposure concentrations were measured. Meanwhile, a control group of 10 nonexposed workers contributed urine samples. The newly developed GC-MS method met regulatory guidelines. RESULTS: The personal exposure concentrations of BeOH ranged from 8.4 to 45.2 mg/m3. Postshift urine samples from exposed participants showed significant BeOH and hippuric acid (HA) concentration increases compared to preshift samples (BeOH, post-/pre-shift geometric mean (GM) ratio = 7.5-7.8, p < 0.001; HA, post-/pre-shift GM ratio = 4.3-4.5, p < 0.001). These levels were considerably higher than those in postshift samples from the nonexposed control group (BeOH, exposed-/nonexposed-workers GM ratio = 14.8-19.0, p < 0.001; HA, exposed-/nonexposed-workers GM ratio = 12.1-15.3, p < 0.001), even after urine density correction. CONCLUSIONS: Urinary BeOH and HA can serve as potential biomarkers of occupational exposure to BeOH. More specifically, BeOH might serve as a superior biomarker than HA because it is apparently less influenced by confounding factors such as dietary intake and genetic polymorphism of low-Km aldehyde dehydrogenase (ALDH2). The findings will improve workplace safety measures and protocols, assisting healthcare professionals in diagnosing and managing exposure-related health issues, thereby potentially reducing the risk of occupational exposure to BeOH.

[Overwhelming postsplenectomy infection 22 years after splenectomy].

A 25-year-old man undergoing splenectomy at 3 years of age to treat idiopathic thrombocytopenic purpura but no history of Streptococcus pneumonia vaccination, and reporting high fever, nausea, and headache developed purpura, confusion, and hypotension the next day and was admitted. Detailed examination showed disseminated intravascular coagulation and multiple-organ dysfunction. Chest X-ray and computed tomography (CT) showed pneumonia and pleural effusion. Blood culture was positive for S. pneumoniae. Gram staining of sputa yielded numerous white blood cells and gram-negative rods, and sputa culture was positive for Pasteurella multocida and Haemophilus influenzae. The medical history and presence of these organisms yielded a diagnosis of overwhelming postsplenectomy infection (OPSI), and the patient responded to treatment with a combination of benzylpenicillin, cefotaxime, and meropenem. This case suggests that patients with a history of splenectomy may benefit from vaccination for S. pneumoniae and adequate education on OPSI.

Comprehensive reduction of amino acid set in a protein suggests the importance of prebiotic amino acids for stable proteins.

Modern organisms commonly use the same set of 20 genetically coded amino acids for protein synthesis with very few exceptions. However, earlier protein synthesis was plausibly much simpler than modern one and utilized only a limited set of amino acids. Nevertheless, few experimental tests of this issue with arbitrarily chosen amino acid sets had been reported prior to this report. Herein we comprehensively and systematically reduced the size of the amino acid set constituting an ancestral nucleoside kinase that was reconstructed in our previous study. We eventually found that two convergent sequences, each comprised of a 13-amino acid alphabet, folded into soluble, stable and catalytically active structures, even though their stabilities and activities were not as high as those of the parent protein. Notably, many but not all of the reduced-set amino acids coincide with those plausibly abundant in primitive Earth. The inconsistent amino acids appeared to be important for catalytic activity but not for stability. Therefore, our findings suggest that the prebiotically abundant amino acids were used for creating stable protein structures and other amino acids with functional side chains were recruited to achieve efficient catalysis.

Anticholinergic effects of artemisinin, an antimalarial drug, in isolated guinea pig heart preparations.

Concern has been growing about the cardiac toxicity of antimalarial drugs. Artemisinin, a unique type of antimalarial drug originating from a Chinese medicinal plant, has minimal adverse effects, but it has been reported to inhibit delayed rectifier potassium current, a voltage-gated potassium current. However, no studies have been published concerning the effect of artemisinin on ligand-gated potassium currents. Therefore, in the present study, we examined the influence of artemisinin on the acetylcholine receptor-operated potassium current (IK.ACh), a ligand-gated potassium current, in guinea pig atrial myocytes using a patch clamp technique. Artemisinin (1 to 300 microM) inhibited I(K.ACh) induced by extracellular application of both carbachol (1 microM) and adenosine (10 microM) and that induced by intracellular loading of GTPgammaS (100 microM) in a concentration-dependent manner. Artemisinin inhibited carbachol-induced, adenosine-induced, and GTPgammaS-activated IK.ACh within almost the same concentration range. In left atria, artemisinin (1 to 100 microM) partially reversed the shortening of action potential duration induced by carbachol in a concentration-dependent manner. Carbachol-induced negative inotropic action in left atria was also inhibited by artemisinin (10 to 300 microM). In conclusion, we suggest that the anticholinergic action of artemisinin is mediated through inhibition of IK.ACh via inhibition of the muscarinic potassium channel and/or associated GTP-binding proteins.

Prediction of transfusions in extremely low-birthweight infants in the erythropoietin era.

BACKGROUND: The purpose of the present paper was to detect the clinical factors most predictive of red blood cell (RBC) transfusion in extremely low-birthweight (ELBW) infants in the recombinant human erythropoietin era. METHODS: Between 1995 and 2000, 66 ELBW infants were admitted to a level III neonatal intensive care unit. Fifty-four of 66 infants were eligible for enrollment in the present study. Infants were treated with erythropoietin 200 IU/kg per dose s.c. twice a week with 4-6 mg/kg per day iron supplement. RESULTS: The mean gestational age and birthweight were 26.5 +/- 2.1 weeks and 776 +/- 134 g, respectively. Ten of 54 ELBW infants (18.5%) died during the first 21 days. Eight of 10 dead infants (80.0%) and 27 of 44 surviving infants (61.4%) received one or more RBC transfusions. The overall requirement for RBC transfusions in the surviving infants was 3.0 +/- 3.2 per infant/hospital course (range: 0-9) . There were significant differences in gestational weeks, birthweight, initial hemoglobin value, 5 min Apgar score, phlebotomy loss, phlebotomy loss/birthweight, duration of mechanical ventilation, duration of oxygen supplement, and incidence of both intraventricular hemorrhage and chronic lung disease between the transfused and non-transfused group. The predictive variables, initial hemoglobin level (odds ratio [OR] 2.61; 1 g/dL), birthweight (OR 3.00; 100 g), and gestational week (OR 1.89; 1 week), were found to be most predictive for transfusion on logistic regression analysis. CONCLUSION: ELBW infants are still the population at greatest risk for repeated blood transfusions after introduction of erythropoietin treatment. If labor develops, it is often impossible to extend the pregnancy period, therefore efforts should be made to increase hemoglobin level at birth.

Autologous cord blood transfusion in an infant with a huge sacrococcygeal teratoma.

We describe a case of cord blood harvest for autologous transfusion in a neonate weighing 3,992 g with a giant sacrococcygeal teratoma. The umbilical vein was pierced with an 18-gauge needle, and placental blood was withdrawn into two 50-ml syringes filled with 4 ml of citrate-phosphate-dextrose solution. Resection of the sacrococcygeal teratoma was performed on day one. During the operation the infant lost 46 ml of whole blood, more than 15% of the estimated total blood volume, and thus underwent autologous transfusion with 27.8 ml of packed red cells obtained from autologous cord blood. Consequently, she could avoid homologous blood transfusion during the hospital stay. This case highlights the safety of this procedure, with no evidence of consumption coagulopathy, hemolysis or bacterial infection.