Context: Acquired methemoglobinemia is a potentially fatal condition that leads to tissue hypoxia. Although the clinical features of methemoglobinemia depend on the methemoglobin levels, the clinical ...course would differ depending on the causative agents.
Objective: We attempted to clarify this issue by comparing the clinical course of methemoglobinemia caused by dapsone and that caused by other toxic agents.
Materials and methods: A retrospective case-control study was performed. All patients with methemoglobinemia and who were admitted to the emergency department (ED) of our hospital from 1 January 2002 to 31 December 2014 were included.
Results: Of the 34 patients with methemoglobinemia, 15 ingested dapsone (14 with acute overdose and one with chronic therapeutic use) and 19 had been exposed to other toxic agents, such as sodium nitrites, indoxacarb, primaquine, and lidocaine. The clinical characteristics and the course of dapsone-induced and other toxic-agent-induced methemoglobinemia were compared. There was no significant difference in clinical presentation and methemoglobin level (38.5% vs. 35.0%, p = 0.456) upon their ED arrival between the two groups. However, the methemoglobin level after use of methylene blue and the total dose of methylene blue were higher in patients with dapsone-induced methemoglobinemia than in those with other agent-induced methemoglobinemia (11.9% vs. 1.7%, p = 0.001, 455 mg vs. 144 mg, p = 0.006). The majority of dapsone-induced methemoglobinemia (93.3%) required more than 72 h for normalization of the methemoglobin level, despite the use of methylene blue. Five of the study patients died due to multiorgan failure, and all of whom were inpatients with dapsone-induced methemoglobinemia.
Conclusion: The clinical course of dapsone-induced methemoglobinemia was worse than that of other toxic-agent-induced methemoglobinemia despite no significant difference in their initial clinical presentation. Continuous treatment with serial monitoring of the serum methemoglobin is necessary for patients with dapsone-induced methemoglobinemia.
The asymmetric giant magnetoimpedance curves have been measured under the rotation of magnetic field on the weak-field annealed Co-based amorphous ribbons to analyze the characteristics of bias ...field. The bias field from the hard magnetic phases is expected to be of an order of 100
Oe along the annealing field direction. The effective field of soft magnetic phase in the field region parallel to the bias field is less than that antiparallel to the bias field, indicating that an antiferromagnetic exchange coupling exists between the magnetization of the soft phase and the bias field of the hard magnetic phases.
Despite recently increasing numbers of reports on intraductal papillary mucinous tumors (IPMTs), difficulties still remain in terms of diagnosis, treatment, and prognosis. The purpose of this ...multicenter study was to evaluate the clinicopathologic features of IPMT in Korea and to suggest predictive criteria for malignancy in IPMT.
We retrospectively reviewed the clinicopathologic data of 208 patients who underwent operations for IPMT between 1993 and 2002 at 28 institutes in Korea.
Of the 208 patients (mean age, 61 years), 147 were men and 61 were women. A total of 124 patients underwent pancreatoduodenectomy, 42 underwent distal pancreatectomy, 17 underwent total pancreatectomy, and 25 underwent limited pancreatic resection. There were 128 benign cases (adenoma, n = 62; borderline, n = 66) and 80 malignant cases (noninvasive, n = 29; invasive, n = 51). A significant difference in 5-year survival was observed between the benign and malignant groups (92.6% vs. 65.3%; P = .006). Of the six factors (age, location, duct dilatation, mural nodule, main duct type, and tumor size) that showed statistical differences by univariate analysis between the benign and malignant groups, three were significant by multivariate analysis--namely, mural nodule (P = .009), tumor size (P = .023), and a dilated duct size (P = .010).
A significant proportion of IPMTs are malignant, although the overall prognosis of IPMT is superior to that of ordinary pancreatic cancer. Radical surgery is recommended for IPMT with the predictors of malignancy: mural nodule, tumor size (> or =30 mm), and dilated duct size (> or =12 mm).
Analysis and design techniques of charge-pump-based RF antenna-switch controllers are presented. Loading effects of RF antenna switches that cause voltage drop of the controller have been identified ...and embedded in the analysis. The proposed analysis also captures effects of MOS-switch on-resistance and parasitic capacitances, so more precise descriptions of the charge-pump output voltage can be obtained. Furthermore, the body biasing technique has been employed to prevent latch-up. The analysis and the design techniques have been verified using a 0.35-mum CMOS technology. RF antenna-switch performances with the designed controller have also been measured and presented.
HslVU is an ATP-dependent protease consisting of HslU ATPase and HslV peptidase. In an HslVU complex, the central pores of
HslU hexamer and HslV dodecamer are aligned and the proteolytic active sites ...are sequestered in the inner chamber of HslV.
Thus, the degradation of natively folded proteins requires unfolding and translocation processes for their access into the
proteolytic chamber of HslV. A highly conserved GYVG 93 sequence constitutes the central pore of HslU ATPase. To determine the role of the pore motif on protein unfolding and translocation,
we generated various mutations in the motif and examined their effects on the ability of HslU in supporting the proteolytic
activity of HslV against three different substrates: SulA as a natively folded protein, casein as an unfolded polypeptide,
and a small peptide. Flexibility provided by Gly residues and aromatic ring structures of the 91st amino acid were essential
for degradation of SulA. The same structural features of the GYVG motif were highly preferred, although not essential, for
degradation of casein. In contrast, none of the features were required for peptide hydrolysis. Mutations in the GYVG motif
of HslU also showed marked influence on its ATPase activity, affinity to ADP, and interaction with HslV. These results suggest
that the GYVG motif of HslU plays important roles in unfolding of natively folded proteins as well as in translocation of
unfolded proteins for degradation by HslV. These results also implicate a role of the pore motif in ATP cleavage and in the
assembly of HslVU complex.
Rifampin-Resistant Mycobacterium kansasii Wallace, Richard J.; Dunbar, Denise; Brown, Barbara A. ...
Clinical infectious diseases,
05/1994, Volume:
18, Issue:
5
Journal Article
Peer reviewed
We identified 36 rifampin-resistant Mycobacterium kansasii isolates, including 17 (4%) of 464 isolates recovered in Texas between 1989 and 1992. Of 29 patients infected with rifampin-resistant M. ...kansasii whose history of medication was known, 90% had previously received rifampin, and 58% of these patients had been treated with one or two effective drugs. Thirty-two percent of rifampin-resistant isolates recovered since 1989 were from patients who were seropositive for human immunodeficiency virus (HIV) infection. Twenty courses of therapy with a four-drug regimen determined on the basis of in vitro susceptibilities were administered to 16 patients from whom rifampin-resistant isolates were recovered; the therapy did not include surgery. Sputum cultures converted to negative as the result of 90% of treatments (time to conversion: mean, 11 weeks; range, 4–20 weeks). Bacteriologic relapses occurred in four of five patients who withdrew from therapy after being culture negative for ⩽6 months of therapy and in one of 12 patients who were culture negative for at least 12 months of therapy (mean, 16.3 months). This study suggests that the prognosis for cure of infection due to rifampin-resistant M kansasii with chemotherapy alone is excellent, although the number of cases appears to be increasing, in part because of the HIV disease epidemic.
Chemical Mechanical Polishing (CMP) refers to a material removal process done by rubbing a work piece against a polishing pad under load in the presence of chemically active abrasive containing ...slurry. The CMP process is a combination of chemical dissolution and mechanical action. The mechanical action of CMP involves hydrodynamic lubrication. The liquid slurry is trapped between the work piece (wafer) and pad (tooling) forming a lubricating film. For the first step to understand the mechanism of the CMP process, hydrodynamic analysis is done with a semiconductor wafer. Slurry pressure distribution, resultant forces and moments acting on the wafer are calculated in typical conditions of the wafer polishing, and then nominal clearance of the slurry film, roll and pitch angles at the steady state are obtained.
The polymerization of 2‐butene and its copolymerization with ethylene have been investigated using four kinds of dichlorobis(β‐diketonato)titanium complexes, ArN(CH2)3NArTiCl2 (Ar = 2,6‐iPr2C6H3) and ...typical metallocene catalysts. The obtained copolymers display lower melting points than those produced of homopolyethylene under the same polymerization conditions. 13C NMR analysis indicates that 9.3 mol‐% of 2‐butene units were incorporated into the polymer chains with Ti(BFA)2Cl2‐MAO as the catalyst system. With the trans‐2‐butene a higher copolymerization rate was observed than with cis‐2‐butene. A highly regioselective catalyst system for propene polymerization, ArN(CH2)3NArTiCl2 complex using a mixture of triisobutylaluminium and Ph3CB(C6F5)4 as cocatalyst, was found to copolymerize a mixture of 1‐butene and trans‐2‐butene with ethylene up to 3.1 mol‐%. Monomer isomerization‐polymerization proceeds with typical metallocene catalysts to produce copolymers consisting of ethylene and 1‐butene.
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