Effect of occlusal stabilisation splint with or without arthroscopic disc repositioning on condylar bone remodelling in adolescent patients

The aim of this study was to investigate the treatment effects of a stabilisation splint (SS) with and without arthroscopic disc repositioning (ADR) on condylar bone remodelling in adolescent patients with anterior disc displacement without reduction (ADDwoR). Cone beam computed tomography and magnetic resonance imaging were used to analyse condylar bone remodelling, condyle position, and disc position. Twenty-two temporomandibular joints of 14 patients who underwent ADR (age range 12-20 years; mean follow-up 12.5 ± 7.8 months) and 21 temporomandibular joints of 14 patients who did not undergo ADR (age range 13-20 years; mean follow-up 11.1 ± 5.1 months) were included. The change in bone volume (P < 0.001), rate of bone volume change (P < 0.001), and change in condyle height (P = 0.031) were significantly greater in patients with ADR than in those without ADR. The changes in posterior joint space (P = 0.013), superior joint space (P = 0.020), and ratio of condyle sagittal position (P = 0.013) were significantly greater in patients with ADR than in those without ADR. All discs in patients who underwent ADR and one disc in those who did not undergo ADR were backward repositioned. In conclusion, in adolescent patients with ADDwoR, ADR with SS therapy achieved better condyle and disc position than SS therapy alone, and also induced bone generation.

Compare image quality of T2-weighted imaging with different phase acceleration factors

Previous studies demonstrated that adjusting the phase acceleration (PA) factors could influence image quality. To improve image quality and decrease respiratory artifacts of lesions in the liver on T2-weighted image by adjusting PA factor and number of excitation (NEX). Sixty consecutive patients with hepatic lesions were enrolled in this prospective research between May 2020 and June 2020. All patients had 3.0T magnetic resonance imaging with 4 sequences (combining PA factors and NEXs, the former was 2 and 3, the latter were 1.5 and 2, respectively, with the same other scanning parameters). Two readers used 5-point quality scales to assess image quality. The signal intensity was measured by drawing regions of interest in the liver, spleen, and background on the T2-weighted imaging. Artifacts, overall image impression, and vascular conspicuity were better when the PA factor was 3 than 2. Artifacts and vascular conspicuity were better when NEX was 2 than 1.5. PA factor 3 and NEX 2 got a higher score in 5-point quality scales and less scan time than the other 3 sequences. Meanwhile, the signal-to-noise ratio of PA factor 3 and NEX 2 was best among these 4 sequences. PA factor and NEX could influence the imaging quality and lesion-to-hepatic contrast in detecting hepatic lesions on T2-weighted images. PA factor 3 and NEX 2 may have a positive effect in the clinic, especially for those with irregular respiration, as it decreased artifacts and reduced scan time.

Pulmonary valve annular and right ventricular outflow tract size as predictions values for moderate to severe pulmonary regurgitation after repaired Tetralogy of Fallot

OBJECTIVE

This study sought to investigate the variation of right heart structure pre- and post-operation as risk factors for moderate to severe pulmonary regurgitation (PR) after repaired Tetralogy of Fallot and the best "cutoff" values for the transannular patch (TAP).

METHODS

We collected surgical, echocardiographic, and computed tomographic data of Teralogy of Fallot (TOF) patients over two years and calculated z-score values based on the echocardiographic data. Based on the PR level after follow-up, the patients were divided into two groups, trivial to mild PR and moderate to severe PR. A multivariate logistic regression analysis was performed, and the receiver operating characteristic curve analysis was used to find the best "cutoff" value for risk factors.

RESULTS

A total of 104 TOF patients were included in our cohort study. From the multivariate analysis, correction strategy (P = .002), difference in zRVOT (OR 1.974, 95% CI 1.354 to 2.878, P < .0001), and zPVA (OR 3.605, 95% CI 1.980 to 6.562, P < .0001) were the significant risk factors for moderate to severe PR. The "cutoff" value for the difference in zPVA that could predict moderate to severe PR in the TAP group was 3, and the optimal "cutoff" value for TAP was -1.4.

CONCLUSIONS

The TAP is a risk factor for significant PR after surgery. We recommend the optimal "cutoff" value for TAP is -1.4 calculated using Shan-Shan Wang's data set. During the procedure, to limit the RVOT resection and restrict the enlargement of pulmonary annulus within a variation of z-score as 3 would reduce significant PR.

Role of Whole-exome Sequencing in Phenotype Classification and Clinical Treatment of Pediatric Restrictive Cardiomyopathy

Background:

Restrictive cardiomyopathy (RCM) is the least common cardiomyopathy in which the walls are rigid and the heart is restricted from stretching and filling properly. Cardiac troponin I (cTnI) mutation-caused myofibril Ca²⁺ hypersensitivity has been shown to be associated with impaired diastolic function. This study aimed to investigate the linkage between the genotype and clinical therapy of RCM.

Methods:

Five sporadic pediatric RCM patients confirmed by echocardiography were enrolled in this study. Whole-exome sequencing (WES) was performed for the cohort to find out candidate causative gene variants. Sanger sequencing confirmed the WES-identified variants.

Results:

TNNI3 variants were found in all of the five patients. R192H mutation was shared in four patients while R204H mutation was found only in one patient. Structure investigation showed that the C terminus of TNNI3 was flexible and mutation on the C terminus was possible to cause the RCM. Catechins were prescribed for the five patients once genotype was confirmed. Ventricular diastolic function was improved in three patients during the follow-up.

Conclusions:

Our data demonstrated that TNNI3 mutation-induced RCM1 is the most common type of pediatric RCM in this study. In addition, WES is a reliable approach to identify likely pathogenic genes of RCM and might be useful for the guidance of clinical treatment scheme.

Balloon Angioplasty as a Modality to Treat Children with Pulmonary Stenosis Secondary to Complex Congenital Heart Diseases

BACKGROUND

Pulmonary stenosis is common in children with complex congenital heart diseases. Proper management of this problem, especially postoperatively, is still controversial. This study was designed to assess the rate and determinants of success or failure of balloon angioplasty for such lesions.

METHODS

Clinical and hemodynamic data from 40 pediatric patients (24 boys and 16 girls) with complex congenital heart diseases who underwent balloon angioplasty were reviewed retrospectively from January 2012 to December 2016. Patients were divided into four groups according to the site of stenosis, which included pulmonary valve stenosis (PVS), valved conduit stenosis, pulmonary artery stenosis (PAS), and supravalvular pulmonary stenosis (SVPS). Success rates were calculated according to defined criteria for initial success and favorable clinical impacts, and comparison between the successful subgroup and the unsuccessful subgroups was analyzed.

RESULTS

Grouped by the site of stenosis, initial success rates varied from 40.0% to 52.4% with the greatest success being seen in the PVS group, followed by the PAS group and SVPS group. In the PVS group and the PAS group, there was no statistical difference among age at dilation, postoperative interval, balloon/stenosis ratio, or pressure gradient predilation between the successful and the unsuccessful subgroups. Favorable clinical impacts included success rates of balloon angioplasty in the SVPS group, which was best (100%), followed by the PVS group (90.9%) and the PAS group (85.7%). There were a total of two transient complications (5.0%).

CONCLUSIONS

Balloon angioplasty was proven to be a safe and useful modality in children with complex congenital heart diseases and postoperative pulmonary stenosis, which should be the initial therapeutic modality in selected patients.

[The study of genistein attenuating genioglossus muscle fatigue under chronic intermittent hypoxia]

OBJECTIVE

To investigate the effects of genistein on genioglossus muscle function and nuclear factor erythroid 2 related factor 2(Nrf-2)/antioxidant responsive element(ARE) signaling pathway in rats under chronic intermittent hypoxia(CIH) condition in order to find medication treatment of obstructive sleep apnea/hyponea syndrome.

METHODS

Thirty female Sprague-Dawley(SD) rats (8 weeks old) were randomly(random number table) divided into three groups 1 week after ovariectomy: control group(NC group), CIH group, and CIH+genistein treatment group(T group). Rats in the latter two groups were exposed to CIH for 8 h/d for 5 weeks. Electrophysiological method was used to detect the change of genioglossus muscle function, and real-time reverse transcription(RT)-PCR and Western blotting were used to determine the level of Nrf-2 gene and protein.

RESULTS

Compared to NC group, the contractive properties of genioglossus muscle fatigue test at every time set was significantly decreased in CIH group(P<0.05). Compared to CIH group, the contractive properties was significantly increased in T group(P<0.05). The level of Nrf-2 gene and protein were less in CIH group(0.54±0.11 and 0.35±0.13) than in NC group(1.00±0.001.00±0.00)(P<0.05). Compared to CIH group the level of Nrf-2 gene and protein were increased in T group (0.76 ± 0.16 and 0.63 ± 0.14) (P<0.05), however, it was still less than the level in NC group(P<0.05).

CONCLUSIONS

CIH attenuates genioglossus muscle fatigue resistance under chronic intermittent hypoxia through Nrf-2/ARE signaling pathway. Genistein protects genioglossus muscle function through up-regulation of the level of Nrf-2 gene and protein.

Value of the Ratio of Occluder Versus Atrial Septal Length for Predicting Arrhythmia Occurrence after Transcatheter Closure in Children with Ostium Secundum Atrial Septal Defect

Background:

Transcatheter occlusion has been applied to treat ostium secundum atrial septal defect (OS ASD) since 1997. During the clinical practice, several postoperative complications including arrhythmia have been reported. This study aimed to evaluate the value of the ratio of atrial septal occluder (ASO) versus atrial septal length (ASL) for predicting arrhythmia occurrence after transcatheter closure in children with OS ASD.

Methods:

Six hundred and fifty-one children diagnosed with OS ASD underwent occlusion procedures after completing routine examinations. The onsets and types of arrhythmia both during and after the occlusion procedures were monitored. Treatments were given based on the individual types of arrhythmia. The binary logistic regression analysis and receiver-operating characteristic (ROC) curve were used in the analysis of value of the ratio of ASO/ASL for predicting postoperative arrhythmia occurrence.

Results:

Transcather occlusions were conducted in 651 children, among whom 7 children had different types and degrees of arrhythmia, with an incidence of 1.1%. The types of arrhythmia included sinus bradycardia, atrial premature beats, bundle branch block, and different degrees of atrioventricular block. Normal electrocardiograph findings were resumed in these 7 patients following active therapies such as corticoids, nutrition, and surgeries. The binary logistic regression and ROC analysis suggested that the ratio of ASO/ASL exhibited an intermediate predictive value for predicting arrhythmia occurrence after occlusion procedures. A cut-off value of 0.576 in the ratio provided a sensitivity of 87.5% and a specificity of 76.2% with an area under the ROC curve of 0.791 (95% confidence intervals, 0.655–0.926; P < 0.05) in predicting arrhythmia occurrence after the closure procedures.

Conclusions:

The ratio of ASO/ASL might be a useful index for predicting arrhythmia occurrence after closure procedures in children with OS ASD.

Comparison of molar intrusion efficiency and bone density by CT in patients with different vertical facial morphology

The purpose of this study is to examine the relationship between molar intrusion efficiency and bone density in patients with different vertical facial morphology. Thirty-six female patients, with overerupted upper first molars, were divided into two groups according to mandiblular plane angle (FH-MP): hyperdivergent, FH-MP>30° (G1), hypodivergent, FH-MP<22° (G2). Mini-screw implants with elastic chains were used to intrude upper first molars. Spiral CT was used to measure the intrusion degree of upper first molar and bone density, and molar intrusion efficiency was calculated as amount/duration (mm month(-1) ). In addition, each tooth was divided into three portions (cervical, furcation and apical) to measure the bone density. It was found in this study that treatment duration was 3·13 and 4·71 months in G1 and G2 and that the intrusion efficiency was 1·57 and 0·81 in G1 and G2 with significant difference (P < 0·05). There were significant differences in cervical, furcation and apical bone density between two groups (P < 0·05). The bone density was significantly reduced after molar intrusion. In addition, the bone density change was greater in G1 than in G2 (P < 0·05). It was concluded that molars were more easily to be intruded in hyperdivergent than in hypodivergent patients. The difference of bone density and bone density changes during intrusion may account for the variation of molar intrusion efficiency.

Prolonged total isovolumic time is related to reduced long-axis functional recovery following valve replacement surgery for severe aortic stenosis

BACKGROUND

The left ventricular (LV) long axis (Lax) function is very sensitive in documenting myocardial abnormalities in aortic stenosis (AS). We hypothesized that Lax recovery after aortic valve replacement (AVR) is related to the extent of cavity dyssynchrony measured by total isovolumic time (t-IVT).

METHODS

A consecutive 107 patients (aged 70 ± 7 years, 70 male) with severe AS and Lax impairment were studied. T-IVT was measured before and after AVR. Reduced Lax function and its post-operative recovery were defined as mitral annular plane systolic excursion (MAPSE) ≦10 mm and an increase of MAPSE >10%, respectively.

RESULTS

LV function improved (EF: 43 ± 8 to 48 ± 10%; MAPSE: 7.9 ± 1.0 to 11.0 ± 2.4 mm) and t-IVT shortened (9.7 ± 3.7 to 7.0 ± 2.8s/min, p<0.01 for all) after AVR. Sixty-five (61%) patients had Lax recovery after a median of 32-month follow-up. Univariate predictors were LV size, LA dimensions, the presence of restrictive LV filling and prolonged t-IVT. Only LV end-systolic dimension, restrictive filling and t-IVT (OR 0.61, 95% CI 0.47-0.79, p<0.01) were independent predictors. A pre-operative t-IVT ≦ 9.3s/min was 81% sensitive and 63% specific in predicting Lax recovery (AUC 0.81, p<0.001). The prevalence of CAD or concomitant CABG were similar in 2 patient groups with different t-IVT.

CONCLUSIONS

Lax recovery was evident in the majority of AS patients after AVR. The lower prevalence of Lax recovery seen in patients with prolonged t-IVT suggests that dyssynchrony may play an important role in the process of adverse LV remodeling.

Biochemical metabolic changes assessed by 31P magnetic resonance spectroscopy after radiation-induced hepatic injury in rabbits

AIM: To compare the features of biochemical metabolic changes detected by hepatic phosphorus-31 magnetic resonance spectroscopy (³¹P MRS) with the liver damage score (LDS) and pathologic changes in rabbits and to investigate the diagnostic value of ³¹P MRS in acute hepatic radiation injury.

METHODS: A total of 30 rabbits received different radiation doses (ranging 5-20 Gy) to establish acute hepatic injury models. Blood biochemical tests, ³¹P MRS and pathological examinations were carried out 24 h after irradiation. The degree of injury was evaluated according to LDS and pathology. Ten healthy rabbits served as controls. The MR examination was performed on a 1.5 T imager using a ¹H/³¹P surface coil by the 2D chemical shift imaging technique. The relative quantities of phosphomonoesters (PME), phosphodiesters (PDE), inorganic phosphate (Pi) and adenosine triphosphate (ATP) were measured. The data were statistically analyzed.

RESULTS: (1) Relative quantification of phosphorus metabolites: (a) ATP: there were significant differences (P < 0.05) (LDS-groups: control group vs mild group vs moderate group vs severe group, 1.83 ± 0.33 vs 1.55 ± 0.24 vs 1.27 ± 0.09 vs 0.98 ± 0.18; pathological groups: control group vs mild group vs moderate group vs severe group, 1.83 ± 0.33 vs 1.58 ± 0.25 vs 1.32 ± 0.07 vs 1.02 ± 0.18) of ATP relative quantification among control group, mild injured group, moderate injured group, and severe injured group according to both LDS grading and pathological grading, respectively, and it decreased progressively with the increased degree of injury (r = -0.723, P = 0.000). (b) PME and Pi; the relative quantification of PME and Pi decreased significantly in the severe injured group, and the difference between the control group and severe injured group was significant (P < 0.05) (PME: LDS-control group vs LDS-severe group, 0.86 ± 0.23 vs 0.58 ± 0.22, P = 0.031; pathological control group vs pathological severe group, 0.86 ± 0.23 vs 0.60 ± 0.21, P = 0.037; Pi: LDS-control group vs LDS-severe group, 0.74 ± 0.18 vs 0.43 ± 0.14, P = 0.013; pathological control group vs pathological severe group, 0.74 ± 0.18 vs 0.43 ± 0.14, P = 0.005) according to LDS grading and pathological grading, respectively. (c) PDE; there were no significant differences among groups according to LDS grading, and no significant differences between the control group and experimental groups according to pathological grading. (2) The ratio of relative quantification of phosphorus metabolites: significant differences (P < 0.05) (LDS-moderate group and LDS-severe group vs LDS-control group and LDS-mild group, 1.94 ± 0.50 and 1.96 ± 0.72 vs 1.43 ± 0.31 and 1.40 ± 0.38) were only found in PDE/ATP between the moderate injured group, the severe injured group and the control group, the mild injured group. No significant difference was found in other ratios of relative quantification of phosphorus metabolites.

CONCLUSION: ³¹P MRS is a useful method to evaluate early acute hepatic radiation injury. The relative quantification of hepatic ATP levels, which can reflect the pathological severity of acute hepatic radiation injury, is correlated with LDS.

A case of primary malignant fibrous histiocytoma of the pancreas: CT and MRI findings

Primary malignant fibrous histiocytoma (MFH) of the pancreas is rare and a distinct clinical entity. We report a case of recurrence of pancreatic MFH with computed tomography (CT) and magnetic resonance imaging (MRI) findings. A 67-year-old man presented with a history of decreased body weight over the past 6 mo. Abdominal CT revealed a large, multilocular cystic mass in the head of the pancreas with obvious atrophy in the body and tail of the pancreas. After 6 mo postoperatively, MRI demonstrated a recurrent large mass in the primary area of the head of the pancreas. The lesion was heterogeneous, hypointense to the liver on T1-weighted imaging, and heterogeneously hyperintense to the liver with a hypointense area in the central part of the tumor on fat-saturated T2-weighted imaging. Contrast-enhanced T1-weighted imaging demonstrated a large multilocular cystic mass with a cystic wall, fibrous septa and enhancement of solid components. To the best of our knowledge, this is the first report on recurrence of primary MFH of the pancreas, and the first with MRI findings.

Analysis of linear alkylbenzenesulfonates by capillary zone electrophoresis with large-volume sample stacking

A systematic investigation of optimal conditions for determining the homologues of linear alkylbenzenesulfonates (LAS) by capillary zone electrophoresis (CZE) using the large-volume sample stacking technique was presented. The most effective sample stacking and separation conditions was 20 mM borate buffer with 30% acetonitrile at pH 9.0, and the sample hydrodynamic injection of up to 90 s at 4 p.s.i. (1 p.s.i. = 6,892.86 Pa) (around 711 nl). Under such conditions, approximately a 100-fold enrichment factor was achieved based on peak heights. The reproducibility of migration time and quantitative results of stacking CZE can be improved by using internal standards. Quantitation limits of the homologues of LAS were 0.002-0.01 mg/l under these enrichment conditions. The analysis of real samples of laundry and dishwashing detergents was performed. The established high-performance liquid chromatography method was applied to evaluate the stacking CZE method, and compatible results were obtained.

Determination of naphthalenesulfonic acid isomers by large-volume on-line derivatization and gas chromatography-mass spectrometry

This work presents a modified method to analyze polar and water-soluble naphthalene monosulfonic acid (NS) isomers in industrial effluents and river water samples. The method involves extraction of samples by a styrene-divinylbenzene copolymer solid-phase extraction cartridge, and on-line derivatization in the GC injection port using a large-volume (10 microl) sample injection with tetrabutylammonium salts. The analytes were then identified and quantitatively determined by GC-MS. The large-volume injection-port derivatization technique provides sensitivity, fast and reproducible results for NS isomers, to quantitation at 0.05 microg/l in 200 ml of water sample. Enhanced extracted mass chromatograms of molecular ion and [M-56]+ ion of butylated NS isomers by electron impact ionization MS allows us to determine residues at trace levels in environmental samples. Recoveries of the NS isomers in spiked water samples ranged from 70 to 82% with RSDs around 10%. Naphthalene-2-sulfonic acid was found as a major pollutant and propagated in surface water and industrial effluents.

Determination of alkylbenzyldimethylammonium chlorides in river water and sewage effluent by solid-phase extraction and gas chromatography/mass spectrometry

This study presents a modified method to analyze alkylbenzyldimethylammonium chlorides (ABDACs) in river water and sewage effluent. The method involves mixed samples with linear alkylbenzenesulfonates (LAS) as a counterion to enhance the extraction of ABDAC residues from an RP-18 solid-phase cartridge by formation of hydrophobic ion-pair complexes. The ABDACs were then eluted with methanol-ethyl acetate (1:1, v/v) and formed to their corresponding alkyldimethylamines by the Hofmann degradation with potassium tert-butoxide. The alkyldimethylamines were then identified and quantitated by gas chromatograph/mass spectrometry (GC/MS). The results indicate that, in the presence of LAS, debenzylation of ABDACs occurs selectively at a temperature higher than 90 degrees C to produce the corresponding nonionic alkyldimethylamines. The method proposed herein provides a high precision and sensitivity for ABDACs, to quantitation at < or =0.1 microg/L in 500 mL of the water samples. The average recovery of ABDAC spiked water samples was 95% with relative standard deviations (RSD, n = 7) of 9%. The RSDs of three replicate environmental sample analyses ranged from 5 to 11%. Direct HPLC method was applied to evaluate the GC/MS method, and compatible results were observed.

Analysis of chlorophenoxy acid herbicides in water by large-volume on-line derivatization and gas chromatography-mass spectrometry

This work presents a modified method to analyze chlorophenoxy acid herbicides in water samples. The herbicides 2,4-D (2,4-dichlorophenoxyacetic acid). Silvex (2,4,5-trichlorophenoxypropionic acid) and 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) were used to evaluate the method. The method involves extraction of samples by a graphitized carbon black cartridge, and on-line derivatization in the GC injection port using a large-volume (10-20 microl) direct sample introduction (DSI) device with tetraalkylammonium salts. The analytes were then identified and quantitated by ion-trap gas chromatography-mass spectrometry. The large-volume DSI injection-port derivatization technique provides sensitivity, fast and reproducible results for chlorophenoxy acid herbicides residues, to quantitation at 0.1 to 0.2 microg/l in 500-ml water samples. An enhanced characteristic mass chromatogram of molecular ions of butylated chlorophenoxy acid herbicides with a significant chlorine isotope pattern by electron impact ionization MS allows us to determine herbicides residues at trace levels in aqueous samples. Recovery of the herbicide residues in spiked various water samples ranged from 70 to 99% while RSDs ranged from 1 to 13%.

Application of pressurized liquid extraction followed by gas chromatography-mass spectrometry to determine 4-nonylphenols in sediments

A time- and solvent-saving method, pressurized liquid extraction (PLE), to extract 4-nonylphenol (4-NP) in sediment was developed. The effects of various operational parameters (i.e., temperature, pressure, etc.) for the quantitative extraction of 4-NP by PLE were investigated. The analytes were then identified and quantitated by a large-volume injection GC-MS technique. The 4-NP can be completely extracted by methanol at 100 degrees C and 100 atm combined with 15 min static and then 10 min dynamic extraction steps (1 atm = 101,325 Pa). Recovery of 4-NP in spiked blank kaolin samples was 98% with 5% RSD. The degrees of recovery of 4-NP in the spiked sediment samples from a reservoir and a polluted river were 111% with 4% RSD and 106% with 5% RSD, respectively. The perfect applicability of PLE for 4-NP was determined after testing it with spiked and aged samples. The extraction efficiency of the PLE was compared with conventional Soxhlet and bath ultrasonication extraction methods using the spiked sediment samples.

Analysis of nonylphenol polyethoxycarboxylates and their related metabolites by on-line derivatization and ion-trap gas chromatography-mass spectrometry

This study presents a modified method to analyze nonylphenol polyethoxycarboxylates (NPEC) and their related metabolites (carboxyalkylphenol ethoxycarboxylates (CNPEC)) in water samples. The method involves extraction of samples by a graphitized carbon black (GCB) cartridge, and direct derivatization in the GC injection-port using a large-volume (10-20 microl) direct sample introduction (DSI) device with tetraalkylammonium (TAA) salts. The analytes are identified and quantitated by ion-trap GC-MS. The large-volume DSI injection-port derivatization technique provides sensitivity, fast and reproducible results for NPEC and their metabolites, to quantitation at 0.1 microg/l in 200 ml of water samples. The retention effect of TAA salts in the injection-port is not detected. In addition, the significant [M-29]+ ions and molecular ions of butylated NPEC and CNPEC residues are observed. Recovery of NP1EC in spiked water samples ranges from 90 to 108%. Moreover, relative standard deviations of replicate analyses ranges from 1 to 9%. However, unsatisfactory on-line derivatization of CNPEC residues is observed. This finding maybe owing to their lesser dissociation with the ion-pair reagent in chloroform.

Occurrence and behavior of wastewater indicators in the Santa Ana River and the underlying aquifers

The occurrence and behavior of wastewater indicator compounds in the Santa Ana River (SAR) water and the underlying aquifer recharged by the SAR has been studied. The SAR contains a high proportion of tertiary treated wastewater effluents, up to 100% during summer and fall. The following water quality parameters were quantified: four specific wastewater indicator compounds, ethylene diaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), a naphthalene dicarboxylate (NDC) isomer, alkylphenol polyethoxy carboxylates (APECs), and selected haloacetic acids (HAAs), nitrate, dissolved oxygen (DO), DOC, total carbohydrate, and phenolic substances. Statistical analysis indicated that normal distribution was adequate to describe the probability distribution of the constituents in most cases. In the river, the concentrations of wastewater indicator compounds decreased as the fraction of storm runoff increased. EDTA and NDC were detected in a monitoring well near the river and in two production wells 1.8 and 2.7 km down gradient with little apparent attenuation. By contrast, NTA, APECs, bromochloro- and dibromoacetic acids appeared to be attenuated significantly during infiltration of river water and groundwater transport.

Analysis of linear alkylbenzenesulfonates in water samples by large-volume injection-port derivatization and gas chromatography-mass spectrometry

This work presents a modified method to analyze linear alkylbenzenesulfonates (LASs) in water samples. The method involves extraction of samples by a graphitized carbon black (GCB) cartridge, and direct derivatization in the GC injection port using a large-volume (10-20 microl) direct sample introduction (DSI) device with tetraalkylammonium (TAA) salts. The analytes were then identified and quantitated by ion-trap GC-MS. The large-volume DSI injection-port derivatization technique provides sensitivity, fast and reproducible results for LAS residues, to quantitation at 0.1 microg/l in 200 ml of water samples. The retention effect of TAA salts in the injection port was not detected. Enhanced selected mass chromatograms of [M-55]+ ions of butylated C10-C13 LASs by electron impact ionization MS allows one to determine LAS residues at trace levels in environmental samples. Recovery of total LASs in spiked variety water samples ranged from 89 to 112% while RSDs ranged from 2 to 13%.

Effects of S-nitrosoglutathione on acute vasoconstriction and glutamate release after subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Subarachnoid hemorrhage (SAH) causes acute vasoconstriction that contributes to ischemic brain injury shortly after the initial bleed. It has been theorized that decreased availability of nitric oxide (NO) may contribute to acute vasoconstriction. Therefore we examined the effect of the NO donor N-nitroso glutathione (GSNO) on acute vasoconstriction and early ischemic glutamate release after experimental SAH.

METHODS

SAH was induced by the endovascular suture method in anesthetized rats. GSNO (1 micromol/L/kg, n=31) or saline (n=21) was injected 5 minutes after SAH. Sham-operated rats received GSNO (1 micromol/L/kg, n=5) 5 minutes after sham surgery. Arterial and intracranial pressures, cerebral blood flow (CBF), and extracellular glutamate release were measured serially for 60 minutes after SAH. SAH size was determined, and vascular measurements were made histologically.

RESULTS

GSNO had no effect on resting blood pressure, intracranial pressure, cerebral perfusion pressure, or CBF in sham-operated animals. However, administration of GSNO after SAH was associated with significantly increased CBF (161.6+/-26.6% versus saline 37.1+/-5.5%, 60 minutes after SAH, P<0.05), increased blood vessel diameter (internal carotid artery [ICA] 285.0+/-16.5 microm versus saline 149.2+/-14.1 microm, P<0.01), decreased vessel wall thickness (ICA12.9+/-0.7 microm versus saline 25.1+/-1.6 microm, P<0.01), and decreased extracellular glutamate levels (3315.6+/-1048.3% versus saline469. 7+/-134.3%, P<0.05). Blood pressure decreased transiently, whereas intracranial pressure, cerebral perfusion pressure, and SAH size were not affected.

CONCLUSIONS

These results suggest that GSNO can reverse acute vasoconstriction and prevent ischemic brain injury after SAH. This further implies that acute vasoconstriction contributes significantly to ischemic brain injury after SAH and is mediated in part by decreased availability of NO.

Analysis of nonylphenol polyethoxylates and their degradation products in river water and sewage effluent by gas chromatography-ion trap (tandem) mass spectrometry with electron impact and chemical ionization

A method is presented for the analysis of nonylphenol polyethoxylate (NPEO) residues and their degradation products, nonylphenol polyethoxy carboxylates and carboxyalkylphenol ethoxy carboxylates, in the samples of river water and sewage effluent. The method involves extraction of the samples by graphitized carbon black (GCB) cartridge, propylation by a propanol/acetyl chloride derivatization procedure, and separation, identification and quantitation by ion-trap GC-MS with electron impact ionization (EI), liquid-chemical ionization (CI) and CI-MS-MS modes. The large-volume injection technique provides high precision and sensitivity for both NPEO residues and their degradation products, to quantitation at > or = 0.01 microgram/l in 100 ml of water samples. Dicarboxylic acids of NPEO residues were identified by the CI-MS-MS technique with relatively high concentrations in the samples of river water and sewage effluent. Recovery of nonylphenol and octylphenoxyacetic acid in spiked water samples ranged from 81 to 107%. Relative standard deviations of replicate analyses ranged from 2 to 12%.

Determination of linear alkylbenzenesulfonates and their degradation products in water samples by gas chromatography with ion-trap mass spectrometry

A method was developed for the analysis of linear alkylbenzenesulfonates (LAS) and their degradation products, sulfophenylcarboxylic acids (SPC), in samples of sewage effluent and river water. This method involved extraction of the samples by graphitized carbon black cartridge, esterification by a two-step thionyl chloride-trifluoroethanol derivatization procedure, and separation, identification and quantitation by ion-trap GC-MS with EI and low pressure CI modes. High selectivity with few signals was observed in the low pressure CI mass spectra of LAS and SPC. Enhanced sensitivity with protonated molecular ion chromatograms of homologous C10-C13 LAS by CI-MS permit the determination of LAS and SPC at trace concentrations in environmental samples. Recovery rates of LAS and SPC in spiked water samples ranged from 75 to 112% with R.S.D. values from 3 to 26%. The limit of quantitation for both LAS and SPC was estimated to be 0.01 microgram/l in 100 ml of water sample.

Acute vasoconstriction after subarachnoid hemorrhage

OBJECTIVE

Decreased cerebral blood flow (CBF) and cerebral ischemia occurring immediately after subarachnoid hemorrhage (SAH) may be caused by acute microvascular constriction. However, CBF can also be influenced by changes in intracranial pressure (ICP) and cerebral perfusion pressure (CPP). The goal of these experiments was to assess the significance of acute vasoconstriction after SAH and its relationship to changes in CBF, ICP, CPP, and extracellular glutamate concentrations.

METHODS

Three experiments were performed using the endovascular filament technique to produce SAH. In the first experiment, CBF, ICP, and CPP were measured for 60 minutes after SAH (n = 21) and were correlated with the 24-hour mortality rate. In the second experiment, rats undergoing SAH (n = 23) or a sham procedure (n = 7) were perfused 60 minutes after SAH for measurement of the circumference and wall thickness of the internal carotid and anterior cerebral arteries and correlation with CBF, ICP, and CPP. In the third experiment (n = 11), extracellular glutamate concentrations determined by hippocampal and cortical microdialysis and high performance liquid chromatography were correlated with physiological changes.

RESULTS

CBF reductions to less than 40% of baseline for 60 minutes after SAH predicted 24-hour mortality with 100% accuracy and were used to define "lethal" SAH. In contrast, ICP and CPP 60 minutes after SAH were not correlated with the mortality rate. The vascular circumference was significantly smaller in lethal than in sublethal SAH or sham-operated rats (P < 0.001). Vessel measurements were correlated with both CBF and hemorrhage size (P < 0.01). Extracellular glutamate concentration increased to 600% of baseline after lethal SAH in both hippocampus and cortex and was inversely correlated with CBF (r = 0.9, P < 0.001) but did not increase after sublethal SAH.

CONCLUSION

Acute vasoconstriction after SAH occurs independently of changes in ICP and CPP and is associated with decreased CBF, larger hemorrhage size, persistent elevations of extracellular glutamate, and poor outcome. Acute vasoconstriction seems to contribute directly to ischemic brain injury after SAH. Further evaluations of pharmacological agents with the potential to reverse acute vasoconstriction may increase CBF and improve outcome.

[Calcitonin gene-related peptide and thrombolysis]

After thrombolytic therapy with urokinase (UK) plasmaimmunoreactive calcitonin gene-related peptide (CGRP-ir) in patients with acute myocardial infarction (AMI) was increased rapidly, and 2 hours after treatment with UK the plasma CGRP-ir reached peak value which was 5 times higher than that before thrombolytic therapy. Fourteen hours after therapy with UK the plasma CGRP-ir gradually decreased to the initial level before treatment. In rat model with abdominal aorta thrombosis induced by FeCl3-injured vascular endothelium, it was found that change in plasma CGRP-ir of the rats after treatment with UK was similar to that of AMI patients, and that administration of CGRP alone had no recanalization effect on the thrombotic blood vessel. However, treatment with CGRP synergically potentiated the UK-induced vascular recanalization in a dose-dependent manner. And antagonist of CGRP (CGRP8-37) significantly attenuated the recanalization action of UK. The results suggest that release of CGRP by tissues could play an endogenous protective role in thrombolytic therapy with UK, and exogenous administration of CGRP might be useful clinically as an assistant of vascular recanalization.

[Evaluation of head-chest lead ECG in the diagnosis of acute right ventricular infarction]

The clinical features, hemodynamic parameters, Wilson's lead and head-chest (H-C) lead ECG of 23 cases with acute right ventricular infarction (ARVI) were analyzed. Results showed that 13 cases revealed clinical right heart failure, but 10 of them had clear lung fields. 11 cases showed hypotension. 20 cases had mean right atrial pressure (MRAP) > or = 10 mmHg. The remaining 3 cases had MRAP between 8 mmHg and 10 mmHg, but it was > or = 10 mmHg after volume loading. The ratio of MRAP to pulmonary wedge pressure was > 0.65 and the right ventricular stroke work index < 5.0 g.m/m2 in all the 23 cases. ST elevation > or = 1 mm in V3R to V6R was found in 12 cases (52%), while ST elevation > or = 1 mm in HV3R to HV8R in 20 cases (87%). The results showed that the diagnostic accuracy for ARVI with H-C lead (right chest) ECG is higher than that with Wilson's lead. H-C ECG is better correlated with hemodynamics in patients with ARVI.

Elevated circulating tumor necrosis factor levels in Alzheimer's disease

Recent investigations have demonstrated a local inflammatory response in Alzheimer's disease (AD), including microglia and cytokines. Levels of the cytokine tumor necrosis factor alpha (TNF-alpha) in sera from patients with AD and age-matched controls were measured by an enzyme-linked immunoassay and a cytotoxicity bioassay. Significantly elevated levels of TNF were found in AD sera compared to controls. Elevated circulating TNF may be derived from the local CNS inflammatory reaction in AD, and may account for some systemic manifestations of AD such as weight loss. Future studies may determine if, in the absence of complicating disorders which may elevate TNF, circulating TNF could be a marker of AD inflammatory activity.

Biochemical effects of PR toxin on rat liver mitochondrial respiration and oxidative phosphorylation

The in vitro effects of PR toxin, a toxic secondary metabolite produced by certain strains of Penicillium roqueforti, on the membrane structure and function of rat liver mitochondria were investigated. It was found that the respiratory control and oxidative phosphorylation of the isolated mitochondria decreased concomitantly when the toxin was added to the assay system. The respiratory control ratio decreased about 60% and the ADP/O ratio decreased about 40% upon addition of 3.1 X 10(-5) M PR toxin to the highly coupled mitochondria. These findings suggest that PR toxin impairs the structural integrity of mitochondrial membranes. On the other hand, the toxin inhibited mitochondrial respiratory functions. It exhibited noncompetitive inhibitions to succinate oxidase, succinate-cytochrome c reductase, and succinate dehydrogenase activities of the mitochondrial respiratory chain. The inhibitory constants of PR toxin to these three enzyme systems were estimated to be 5.1 X 10(-6), 2.4 X 10(-5), and 5.2 X 10(-5) M, respectively. Moreover, PR toxin was found to change the spectral features of succinate-reduced cytochrome b and cytochrome c1 in succinate-cytochrome c reductase and inhibited the electron transfer between the two cytochromes. These observations indicate that the electron transfer function of succinate-cytochrome c reductase was perturbed by the toxin. However, PR toxin did not show significant inhibition of either cytochrome oxidase or NADH dehydrogenase activity of the mitochondria. It is thus concluded that PR toxin exerts its effect on the mitochondrial respiration and oxidative phosphorylation through action on the membrane and the succinate-cytochrome c reductase complex of the mitochondria.