Quantum chemical analysis of the deferiprone-iron binding reaction

To prevent side effects of excessive accumulation of iron in the body, chelation therapy is recommended in transfusion-dependent patients. The reaction between deferiprone and iron to form a complex red substance can be described as 3 molecules of the chelator, deferiprone, reacting with a molecule of iron. However, the actual mechanism of the deferiprone-iron binding reaction is not well understood. A quantum chemical analysis of the deferiprone-iron binding reaction was performed, focusing on the reaction between 1 molecule of deferiprone and I molecule of iron. The two main alternative pathways for the deferiprone-iron binding reaction were shown to be C-C cleavage and C-O cleavage. The required energy for complex formation in C-C cleavage was less than for C-O cleavage. The total energy requirement for C-C cleavage was negative, implying that this reaction can occur without any external energy source. The resulting complex fits the reported tertiary structure model for the deferiprone-iron complex.     

Tertiary structural analysis of the elongated part of an abnormal hemoglobin, hemoglobin Pakse

Hemoglobin variants in which a frameshift results in chain elongation are unusual. Hemoglobin Pakse (Hb Pakse) is an unstable hemoglobin with abnormal elongation, first described in Indochina. An alpha2-globin gene termination codon mutation, TAA -->TAT or Term -->Tyr, has been described in the pathogenesis of Hb Pakse. This abnormality causes a frameshift that elongates the alpha chain amino acids. Computer-based protein structure modeling was used in a bioinformatics analysis of the tertiary structure of these elongated amino acid sequences. The elongated part of Hb Pakse showed additional helices, which may cause the main alteration in Hb Pakse. Abnormalities in the fold structure of globin in Hb Pakse were identified, and helices additional to the normal alpha globin chains were shown in the elongated part of Hb Pakse.     

Indinavir resistance evolution: a comment

Dear Editor, I read the recent report on HIV with a great interest[2].Geng et al concluded that"Indinavir-resistance evolution was observed by single-genome amplification[2]"and"During the course of changing the regimen to incorporate Indinavir,the G73S mutation occurred and was combined with M46I/L90M[2]."I have some points for discussion on this work.First,focusing on the single-genome amplification,although it is acceptable the false positive can still be detected[3].     

A note on indirect hemagglutination (IHA) antibody titers among hospitalized patients in Thailand with amebic liver abscesses

Amebic hepatic abscess is a tropical disease with a wide spectrum of clinical presentations. A retrospective case review was performed on 39 hospitalized patients in Thailand with the diagnosis of amebic liver abscess. A total of 23 men (59%) and 16 women (41%), with a mean age of 44.56 +/- 21.81 years (range, 10 to 88 years), were involved in the study. The average duration of present illness was 7.33 +/- 0.83 days. Abscesses were discovered in the right lobe in 29 patients (74.4%), in the left lobe in 3 patients (7.7%), and in both lobes in 7 patients (17.9%). Thirty patients had single abscesses (76.9%) and 9 patients had multiple abscesses (23.1%). On admission, the average white blood count was 17.37 +/- 6.34 x 1000 WBC/mm3, serum albumin was 2.86 +/- 0.61 g/dL, prothrombin time was 16.52 +/- 5.8 seconds, serum aspartate transaminase (AST) was 92.62 +/- 118.74 U/L, serum alanine transaminase (ALT) was 83.74 +/- 107.84 U/L, serum alkaline phosphatase (ALP) was 407.68 +/- 343.42 U/L, and serum bilirubin was 2.44 +/- 2.08 g/dL. Average indirect hemagglutination (IHA) titer of the cases was 1:1190.35 +/- 895.42 (range, 1:256 to 2048). Concerning the multiple logistic regression analysis, no significant correlation was found between antibody titer and the other parameters. Of interest, pathogenic organisms were detected in stool in only 2 cases. This study shows the usefulness of serologic study in diagnosis of amebic liver abscess.     

High blood lead level among garage workers in Bangkok, public concern is necessary

Lead is an important toxic metal agent found in many industrial processes in the present day. Lead exposure must be of particular concern because of ongoing exposure to thousands of workers in the industrial plants and recent research indicating that asymptomatic lead exposure can result in chronic toxicity manifestations. Therefore, determination and control lead exposure among the risk workers is very necessary. Like other developing countries, lead pollution becomes an important public health problem of Thailand, especially for the big cities as Bangkok but relatively few of these countries have introduced policies and regulations for significantly combating the problem. We set this pilot study to determine the blood lead levels by anodic stripping volammetry (ASV) method as a marker for lead exposure among the occupational exposed and control subjects. Totally 89 subjects, 20 control subjects and 69 garage workers (52 mechanics and 17 dye sprayers), as the representatives of occupational exposed subjects, were included into this preliminary study. The mean blood lead level in the control group was 0.32±0.07 mol/l. The mean blood lead level in the mechanics group was 0.42±0.13 mol/l. The mean blood lead level in the dye sprayers was 0.58±0.07 mol/l. Significant higher blood lead levels among the mechanics and dye sprayer groups were observed (P<0.05). Based on this study, the considerations for prevention of possibly exposure to lead among the high-risk workers as public health policies was recommended.