Determination of an iron suspension in water by laser-induced breakdown spectroscopy with two sequential laser pulses

We have applied laser-induced breakdown spectroscopy to quantitative analysis of colloidal and particulate iron in water. A coaxial sample flow apparatus developed in our previous work, which allowed us to control the atmosphere of laser-induced plasma, was used. Using sequential laser pulses from two Q-switched Nd:YAG lasers as excitation sources, the FeO(OH) concentration in the tens of ppb range was determined with an optimum interval between two laser pulses and an optimum delay time of a detector gate from the second pulse. The detection limit of Fe decreased substantially using two sequential laser pulse excitations:  the 0.6 ppm limit of single pulse excitation to 16 ppb with sequential pulse excitation. The effects of the second laser pulse on the plasma emission were studied. The concentration of iron in fine particles in boiler water sampled from a commercially operated thermal power plant has been determined successfully by this method. The results show the capability of laser-induced breakdown spectroscopy in determining suspended colloidal and particulate impurities in a simple and quick way.

Coulomb energy difference as a probe of isospin-symmetry breaking in the upper f p-shell nuclei

The anomaly in Coulomb energy differences (CEDs) between the isospin T=1 states in the odd-odd N=Z nucleus 70Br and the analogue states in its even-even partner 70Se has remained a puzzle. This is a direct manifestation of isospin-symmetry breaking in effective nuclear interactions. Here, we perform large-scale shell-model calculations for nuclei with A=66 to 78 using the new filter diagonalization method based on the Sakurai-Sugiura algorithm. The calculations reproduce well the experimental CED. The observed negative CED for A=70 are accounted for by the cross-shell neutron excitations from the fp shell to the g(9/2) intruder orbit with the enhanced electromagnetic spin-orbit contribution at this special nucleon number.

Low-cost high-speed imaging system for observing vocal fold vibration in voice disorders

PURPOSE

The aim of this study was to establish a method to observe vocal fold vibration using a low-cost high-speed laryngeal imaging system.

PROCEDURES

We assembled a high-speed imaging system with a consumer digital camera and a rigid laryngeal endoscope. The camera can shoot digital images at a rate of 1,200 frames per second and be purchased for about USD 1,000 in Japan.

RESULTS

We examined the normal and pathological vocal folds of 215 subjects with our new system and analyzed the vocal fold vibration in these subjects by playback of a video and kymograph images.

CONCLUSIONS

Our high-speed laryngeal imaging system is highly cost-effective and can be a useful tool for examining the vocal folds of patients with voice disorders.

Arginine 485 of human serum albumin interacts with the benzophenone moiety of ketoprofen in the binding pocket of subdomain III A and III B

Arylpropionic acid nonsteroidal anti-inflammatory drusg (NSAIDs) primarily bind to subdomain III A (site II) of human serum albumin (HSA). Ketoprofen (KP), an arylpropionic acid that contains a photoreactive benzophenone moiety, was used to photolabel the binding region of site II. LC/Q-TOF mass spectrometry determination revealed that R485 was the amino acid residue that formed covalent adduct with the benzophenone moiety of KP. Point mutation of arginine 485 to alanine showed a slight decrease in the overall binding percentage of KP when compared to that of native HSA. The induced circular dichroism spectral data of KP with both R485A and native albumin confirmed the photolabeling findings. Interestingly, an increase in the extent of [14C]KP covalent adduct formation with the 11.6 kDa peptide derived from subdomain IIB-IIIA was observed for R485A. In contrast, mutation of arginine 410 caused a significant reduction of binding percentage, confirming the importance of this residue in high affinity binding of arylpropionic acid derivatives. This may indicate that while KP's carboxylate interacts electrostatically with arginine 410, the benzophenone moiety may have swung away from helix 6 in the absence of arginine 485. In this study, photolabeling of native and mutants albumins, R485A and R410C with [14C]KP confirmed that R485 involved in the non-electrostatic interaction with the benzophenone moiety of KP, but not vital to hold KP in the binding pocket of subdomain IIIA.

Hypoxanthine guanine phosphoribosyltransferase (HPRT) mutations in the Asian population

Mutation of hypoxanthine guanine phosphoribosyltransferase (HPRT) gives rise to Lesch-Nyhan syndrome, which is characterized by hyperuricemia, severe motor disability, and self-injurious behavior, or HPRT-related gout (Kelley-Seegmiller syndrome). The marked heterogeneity of HPRT deficiency is well known, with more than 300 mutations at the HPRT gene locus having been reported (deletions, insertions, duplications, abnormal splicing, and point mutations at different sites of the coding region from exons 1 to 9). We have identified mutations in Asian families with patients manifesting different clinical phenotypes, including rare cases of female subjects, by analyzing all nine exons of the HPRT gene (HPRT1) from genomic DNA and reverse-transcribed mRNA using the polymerase chain reaction technique coupled with direct sequencing. We developed suitable methods to detect the mutations identified from respective families with HPRT deficiency. Then, prenatal genetic diagnoses in HPRT-deficient families were carried out using both mRNA and genomic DNA from chorionic villi or amniotic fluid cells. As shown here in the heterogeneity of HPRT mutations, the spectrum of 70 mutations identified in the Asian population fits the four main conclusions that emerged previously from worldwide analysis.

Simultaneous determination of purine and pyrimidine metabolites in HPRT-deficient cell lines

Genetic mutations in the purine salvage enzyme, hypoxanthine-guanine phosphoribosyltransferase (HPRT), are known to cause Lesch-Nyhan syndrome and Kelley-Seegmiller syndrome. In patients, purine metabolism is different from that of normal persons. We have previously developed a method for simultaneously determining the concentration of purine and pyrimidine nucleosides and nucleotides. This system was applied to determine the concentrations of nucleosides and nucleotides in HPRT-deficient cell lines. The amount of inosine 5'-monophosphate (IMP) was different in Lesch-Nyhan syndrome, Kelley-Seegmiller syndrome, and control cell lines. The difference in the amount of IMP confirmed the mutation of the enzyme.

Valproic acid improves the tolerance for the stress in learned helplessness rats

In this study, we investigated whether previously stressed rats with learned helplessness (LH) paradigm could recover from depressive-like behavior four weeks after the exposure, and also whether chronic treatment with valproic acid (VPA) could prevent behavioral despair due to the second stress on days 54 in these animals. Four weeks after induction of LH, we confirmed behavioral remission in the previously stressed rats. Two-way analysis of variance (ANOVA) performed with two factors, pretreatment (LH or Control) and drug (VPA or Saline), revealed a significant main effect of the drug on immobility time in forced swimming test. Post hoc test showed a shorter immobility time in the LH+VPA group than in the LH+Saline group. Immunohistochemical study of synapsin I showed a significant effect of drug by pretreatment interaction on immunoreactivity of synapsin I in the hippocampus: its expression levels in the regions were higher in the LH+VPA group than in the LH+Saline group. These results suggest that VPA could prevent the reappearance of stress-induced depressive-like behaviors in the rats recovering from prior stress, and that the drug-induced presynaptic changes in the expression of synapsin I in the hippocampus of LH animals might be related to improved tolerance toward the stress.

Dehydroxymethylepoxyquinomicin (DHMEQ) can suppress tumour necrosis factor-α production in lipopolysaccharide-injected mice, resulting in rescuing mice from death in vivo

Dehydroxymethylepoxyquinomicin (DHMEQ), a new nuclear factor (NF)-κB inhibitor, has several beneficial effects, including the suppression of tumour growth and anti-inflammatory effects. DHMEQ can also suppress the production of tumour necrosis factor (TNF)-α induced by lipopolysaccharide (LPS) in vitro. In the present study, we examine the effects of DHMEQ on TNF-α production in vivo and on the survival of mice injected with LPS. When DHMEQ was injected into mice 2 h before LPS injection, the survival of the LPS-injected mice was prolonged. When DHMEQ was injected twice (2 h before LPS injection and the day after LPS injection), all the mice were rescued. The injection of DHMEQ 1 h after LPS injection and the day after LPS injection also resulted in the rescue of all mice. The serum levels of TNF-α in the mice that received both LPS and DHMEQ were suppressed compared to the mice that received only LPS. These results suggest that DHMEQ can be utilized for the prevention and treatment of endotoxin shock.

Tracheal reconstruction using S-shaped skin flaps and a conchal cartilage graft

We have devised a technique of two-stage tracheal reconstruction using S-shaped skin flaps and an aural conchal cartilage graft. During the first operation, S-shaped skin flaps were elevated before resection of the trachea. A tracheocutaneous fistula was created at the tracheal defect using S-shaped skin flaps while placing the conchal cartilage graft underneath. During the second operation, a skin incision was made around the fistula to elevate the hinge flaps, including the cartilage. The edges of the hinge flaps were sutured to form the tracheal lumen, and the area of the skin defect was then closed with double-rotation skin flaps.

Histidine146 of human serum albumin plays a prominent role at the interface of subdomains IA and IIA in allosteric ligand binding

Fatty acids are endogenous ligands of human serum albumin (HSA) that induce conformational changes and participate in allosteric ligand binding to HSA. In a previous study, we showed that, when myristate (MYR) is present, the binding of [(14) C]ketoprofen (KP) to subdomain IA of HSA was increased, indicating that, when MYR binds to HSA, a new binding site in formed in that region. Meanwhile, an N-B transition has been reported to increase the binding of ligands at alkaline pH when the status of albumin is the B-conformer. Six histidine single mutants of HSA, H9A, H39A, H67A, H105A, H128A and H146A were produced and photolabeled with [(14) C]KP at pH 6.5, 7.4 and 8.2 and the role of each histidine in causing the N-B transition induced allosteric ligand binding was examined. Cyanogen bromide cleavage of the photolabeled native HSA showed that subdomain IA was the site of the allosteric binding of KP at pH 8.2. From the photolabeling results, H146 was found to play a prominent role whilst H128 played little or no role in the allosteric binding. However, the remaining 4 mutants did not show a clear photolabeling pattern that was similar to either native HSA or H146A and, as a result, no firm conclusions can be made. An additional histidine mutant, H146I, was produced to confirm the results for H146A. A similar experiment using H146I showed that a benzene ring-like structure at position 146 is required for the allosteric ligand binding to occur.

Long-term results of salvage photodynamic therapy for patients with local failure after chemoradiotherapy for esophageal squamous cell carcinoma

BACKGROUND AND STUDY AIMS

Local failure after chemoradiotherapy (CRT) remains a major problem for patients with esophageal squamous cell carcinoma (ESCC). The aim of this study was to clarify the long-term results of salvage photodynamic therapy (PDT) for local failure.

PATIENTS AND METHODS

Patients were treated with CRT, consisting of more than 50 Gy irradiation and concurrent chemotherapy. The indications for salvage PDT were as follows: 1) absence of lymph-node or distant metastasis after CRT; 2) failure lesion limited to T2; 3) refusal by patient to undergo salvage esophagectomy; 4) written informed consent. PDT was performed using an excimer dye laser at 48 and 72 hours after administration of Photofrin.

RESULTS

A total of 37 consecutive patients underwent salvage PDT. The baseline stage before CRT was as follows: T1/T2/T3/T4 in 3/4/24/6 and N0/1 in 13/24 patients, respectively. Prior to PDT, 20 patients had a uT1 lesion, and 17 had a uT2 lesion; 24 patients had histologically proven local failure. A complete response was achieved in 22 patients (59.5%) following PDT. Esophageal fistulae, stenosis, and phototoxicity occurred in 4 (10.8%), 20 (54.1%), and 2 (5.4%) patients, respectively. Over a median follow-up period of 55 months, the 5-year progression-free (PFS) and overall survival rates of 37 patients following PDT were 20.7% and 36.1%, respectively. The 5-year PFS and overall survival of 24 patients with proven local failure were 17.6% and 34.6%, respectively.

CONCLUSION

Salvage PDT is a curative treatment option for patients with local failure after CRT for ESCC.

KRAS mutations detected by the amplification refractory mutation system-Scorpion assays strongly correlate with therapeutic effect of cetuximab

Background:

We aimed to compare the sensitive and quality-controlled KRAS testing with direct sequencing and to assess the impact on decision making of treatment.

Patients and methods:

We analysed genomic DNA isolated from macrodissected formalin-fixed paraffin-embedded specimens by direct sequencing and an amplification refractory mutation system–Scorpion assay (ARMS/S) method. Cetuximab was administered to patients identified as having wild-type (WT) KRAS using direct sequencing. Therapeutic effects were evaluated according to their KRAS status as determined by ARMS/S.

Results:

Among the 159 patients, the overall mutation rate was determined to be 37.0% by direct sequencing and 44.0% by ARMS/S. For the patients diagnosed as WT by direct sequencing and treated with cetuximab (n=47), a response rate of 16.0% was observed for 38 ARMS/S WT patients, whereas 9 ARMS/S mutant (MUT) patients failed to respond. The ARMS/S WT patients showed significant improvement in progression-free survival (PFS) and overall survival (OS) compared with ARMS/S MUT patients (PFS median 5.0 vs 1.7 months, hazards ratio (HR)=0.29, P=0.001; OS median 12.1 vs 3.8 months, HR=0.26, P=0.001).

Conclusion:

Sensitive and quality-controlled KRAS testing may provide improved predictive power to determine the efficacy of anti-epidermal growth factor antibodies.

Influence of lameness on follicular growth, ovulation, reproductive hormone concentrations and estrus behavior in dairy cows

The objective of this study was to examine the effect of a chronic stressor, lameness, on reproductive parameters. Seventy cows 30–80 days post-partum were scored for lameness and follicular phases synchronized with GnRH followed seven days later by prostaglandin (PG). Fifteen Lame animals did not respond to GnRH ovarian stimulation. Milk progesterone for 5 days prior to PG was lower in the remaining Lame cows than Healthy herdmates. Fewer Lame cows ovulated (26/37 versus 17/18; P = 0.04) and the interval from PG to ovulation was shorter in Lame cows. In Subset 1 (20 animals), the LH pulse frequency was similar in ovulating animals (Lame and Healthy) but lower in Lame non-ovulators. An LH surge always preceded ovulation but lameness did not affect the interval from PG to LH surge onset or LH surge concentrations. Before the LH surge, estradiol was lower in non-ovulating cows compared to those that ovulated and estradiol concentrations were positively correlated with LH pulse frequency. In Subset 2 (45 cows), Lame ovulating cows had a less intense estrus than Healthy cows, although Lame cows began estrus and stood-to-be-mounted earlier than Healthy cows. In conclusion, we have identified several parameters to explain poor fertility in some chronically stressed animals. From 30 to 80 days post-partum, there was a graded effect that ranged from 29% Lame cows with absence of ovarian activity, whereas another 21% Lame cows failed to express estrus or ovulate a low estrogenic follicle; in 50% cows, many reproductive parameters were unaffected by lameness.