Analysis of organic esters of plasticizer in indoor air by GC-MS and GC-FPD

The aim of this study was to assess the performance of a method of analyzing organic esters of plasticizer in indoor air by sampling air in a charcoal tube and extracting the esters in toluene using a gas chromatography-mass spectrometer (GC-MS) and flame photometric detector (FPD). An internal standardization method was used for the GC-MS measurement of phthalate esters, whereas an external calibration method was employed to determine the levels of phosphate esters by FPD. The instrumental detection limit, the instrumental lower limit of determination, and the blank and method detection limits were also determined. Mean recoveries of phthalate esters from the charcoal tube were 97.9-115%. Mean recoveries of phosphate esters were lower but reproducible. Recoveries of the esters from indoor air were generally greater than 80%. For all the compounds, no significant breakthrough was detected up to 100 microg. Thus, indoor organic esters could be accurately determined in the range of 0.6 x 10(-3)-23 microg/m3 by the procedure presented here. Preliminary analysis of the organic esters indicated that exposure to phthalate esters via indoor air inhalation could constitute a significant contribution to total daily intake.

Malignant islet cell tumor projecting into the main pancreatic duct

We report herein a rare case of islet cell tumor showing a unique growth pattern in a patient who developed repeated acute pancreatitis as the tumor's initial symptom. Preoperative imaging examinations showed dilatation of the main pancreatic duct (MPD) and cysts around the pancreatic tail. A distal pancreatectomy with splenectomy was performed because the pancreatitis was localized in the distal pancreas and was not controlled by various drug therapies. Grossly, the tumor consisted of two component parts: a markedly infiltrative part in the pancreatic parenchyma, and a papillary elevated part in the MPD. The MPD was obstructed by the tumor spreading widely along the distal MPD. Microscopically, the tumor was composed entirely of islet cell tumors (nonfunctioning), with several foci of venous and lymphatic involvement. Based on its growth behavior, we assumed that the tumor may have arisen from the MPD or from islet cells closely adjacent to the MPD. The patient's postoperative course was uneventful and he is doing well 2 years after the operation. We discuss the growth pattern of the tumor and the cause of the pancreatitis.

Uncoupling protein 3 and peroxisome proliferator-activated receptor gamma2 contribute to obesity and diabetes in palauans

We examined the genetic contribution of single nucleotide polymorphisms (SNPs) of the energy metabolism-related genes, including beta 3 adrenergic receptor (beta3AR), apolipoprotein E (apo-E), promoter of uncoupling protein 3 (UCP3-p), peroxisome proliferator-activated receptor gamma 2 (PPARgamma2) and leptin receptor (LEPR) to metabolic disorders, in 118 inhabitants of Palau. The data were statistically analyzed and ethnically compared to correlate SNPs and their metabolic parameters. UCP3-p (P < 0.01) and PPARgamma2 (p = 0.05) correlated with plasma HbA1c, and UCP3-p correlated with fasting blood glucose (P < 0.01) in males, but not in females. UCP3-p correlated with body fat (%) (P < 0.01) in females, but not in males. Plasma leptin levels and apo-E were correlated in both groups. The frequency of SNPs for PPARgamma2, LEPR, and UCP3-p are significantly different between Palauans and Caucasians.

Cloning and characterization of three novel genes, ALS2CR1, ALS2CR2, and ALS2CR3, in the juvenile amyotrophic lateral sclerosis (ALS2) critical region at chromosome 2q33-q34: candidate genes for ALS2

Amyotrophic lateral sclerosis is a progressive neurodegenerative disease that manifests as selective upper and lower motor neuron degeneration. The autosomal recessive form of juvenile amyotrophic lateral sclerosis (ALS2) has previously been mapped to the 1.7-cM interval flanked by D2S116 and D2S2237 on human chromosome 2q33-q34. We identified three novel full-length transcripts encoded by three distinct genes (HGMW-approved symbols ALS2CR1, ALS2CR2, and ALS2CR3) within the ALS2 critical region. The intron-exon organizations of these genes as well as those of CFLAR, CASP10, and CASP8, which were previously mapped to this region, were defined. These genes were evaluated for mutations in ALS2 patients, and no disease-associated sequence alterations in either exons or intron-exon boundaries were observed. Sequence analysis of overlapping RT-PCR products covering the whole coding sequence for each transcript revealed no aberrant mRNA sequences. These data strongly indicate that ALS2CR1, ALS2CR2, ALS2CR3, CFLAR, CASP10, and CASP8 are not causative genes for ALS2.

Characteristics of sorption losses of polychlorinated biphenyl congeners onto glass surfaces

Sorption losses to glass surfaces of five polychlorinated biphenyl (PCB) congeners in aqueous solutions were investigated. Adsorption/desorption experiments were conducted under conditions that simulated actual sample handling procedures for environmental samples. It was found that the adsorption loss is related to the degree of chlorination. PCB congener 180 lost the most onto glass surfaces, followed by congeners 138, 101/28, and 52, in decreasing order. More PCB adsorption occurred onto glass under conditions of agitation and higher temperature (22 degrees C) during the five-day experimental period. The salinity effect ("salting out effect") was also observed in this work. The efficiency of desorption (rinsing three times with solvent) was found to be ineffective in extracting adsorbed PCBs. It was necessary to use mechanical shaking for extraction. Storage of samples up to five days resulted in sorption losses as much as 30%, 17%, 30%, 40%, and 55% of PCB 28, 52, 101, 138, and 180, respectively. Sorption losses need to be considered when conducting water sampling or toxicological studies to avoid underestimation of the actual PCB concentrations and their toxic effects.

Association equilibrium of d-methamphetamine and l-methamphetamine with serum albumin

The association equilibria for complex formation between serum albumin (bovine, rat) and the optical isomers of methamphetamine (MAMP) was determined using an ultrafiltration method. It was found that serum albumin/d-MAMP and serum albumin/l-MAMP complexes had distinctly different Scatchard plots with bovine and rat albumin. The binding parameters of each association equilibrium were estimated from the Scatchard plots by Rosenthal's graphic method. This distinguished two kinds of specific binding sites in terms of the association equilibrium between bovine serum albumin and d-MAMP, and one binding site for rat serum albumin and d-MAMP. One specific binding site was found between serum albumin and l-MAMP in both bovine and rat. Molar ellipticities, [theta], of peaks were decreased in the CD spectra of the complexes formed between bovine serum albumin and d-MAMP or l-MAMP when compared with the CD spectrum of bovine serum albumin alone. However, no difference in [theta] was found between the CD spectra of the enantiomers of MAMP in the measured wavelength range. The non-specific binding site was distinct from the specific binding site and resulting from altered tertiary structure of the albumin molecule.

Interpretation and enantiomer analysis of methamphetamine abusers' urine and illegally brewed methamphetamine crystals

This study deals with the high-performance liquid chromatographic identification of methamphetamine (MAMP) and amphetamine (AMP) enantiomers (d- and l-forms) in five illicit MAMP crystals and in urine specimens from 30 Japanese MAMP abusers. The analysis revealed that two of the types of crystals have a different optical purity ratio (l/d) and the other three have a single crystal of either the d- or l-enantiomer. The l/d ratios of two types of crystals were 0.04 and 49.4, and no racemic form (l/d = 1.00) was found. The urinary analysis showed that nonmetabolized MAMP and its demethylated metabolite, AMP, were present in urine specimens of all addicts. The stereoisomeric profiles in urine can be classified roughly into five groups according to the detected amount and the l/d ratio of MAMP and AMP enantiomers collected at one time point. In the first group, only d-MAMP and d-AMP were detected (in 16 cases). In the second group, only l-MAMP and l-AMP were detected (in one case). In the third group, the amount of the l-enantiomer detected, for both MAMP and AMP, was less than that of the d-enantiomer, and the l/d ratio was between 0.004 and 0.54 for MAMP and between 0.01 and 0.07 for AMP (in five cases). In the fourth group, the l-enantiomer of MAMP and AMP was found to be more abundant than the d-enantiomer, and the l/d ratio was between 2.63 and 30.11 for MAMP and between 1.23 and 31.30 for AMP (in four cases). In the fifth group, the amount of l-MAMP detected was greater than that of d-MAMP, and less l-AMP than d-AMP was detected. The l/d ratios were between 1.13 and 8.82 for MAMP and between 0.17 and 0.82 for AMP (in four cases). These results might be suitable for identification and the forensic toxicological investigation of AMP analogues.

Methylation of the hMLH1 promoter in familial gastric cancer with microsatellite instability

Microsatellite instability (MSI), which is recognized as an important mechanism in tumorigenesis, has been reported in familial gastric cancers (FGC). However, genetic defects responsible for this phenotype, that is, mutations in mismatch-repair genes such as hMLH1 and hMSH2, have not been detected in most FGC cases. Earlier studies have shown that the promoter region of the hMLH1 gene was methylated in some sporadic colorectal and endometrial cancers. To determine how FGC acquire MSI, we examined the MSI status, hMLH1-protein expression and methylation status of the hMLH1-promoter region in FGC cases. Out of 9 cancers, 6 from 8 FGC kindreds showed MSI at one or more loci; no germline mutations in the hMLH1 or hMSH2 genes were detected; 4 cancers exhibiting MSI displayed aberrant hMLH1 expression: complete loss in one, decreased level in another, and partially staining pattern in the remaining 2. Methylation in the hMLH1-promoter region was found in these 4 cases. In contrast, the cancers displaying hMLH1-protein expression were not methylated in the hMLH1-promoter region. Our data show a significant association between the absence of hMLH1 expression and methylation of its promoter in FGC cases with MSI. This suggests that the mechanism of inactivation of hMLH1 is epigenetic and that there are other genes responsible for FGC.

Methylation of the hMLH1 promoter in familial gastric cancer with microsatellite instability

Microsatellite instability (MSI), which is recognized as an important mechanism in tumorigenesis, has been reported in familial gastric cancers (FGC). However, genetic defects responsible for this phenotype, that is, mutations in mismatch-repair genes such as hMLH1 and hMSH2, have not been detected in most FGC cases. Earlier studies have shown that the promoter region of the hMLH1 gene was methylated in some sporadic colorectal and endometrial cancers. To determine how FGC acquire MSI, we examined the MSI status, hMLH1-protein expression and methylation status of the hMLH1-promoter region in FGC cases. Out of 9 cancers, 6 from 8 FGC kindreds showed MSI at one or more loci; no germline mutations in the hMLH1 or hMSH2 genes were detected; 4 cancers exhibiting MSI displayed aberrant hMLH1 expression: complete loss in one, decreased level in another, and partially staining pattern in the remaining 2. Methylation in the hMLH1-promoter region was found in these 4 cases. In contrast, the cancers displaying hMLH1-protein expression were not methylated in the hMLH1-promoter region. Our data show a significant association between the absence of hMLH1 expression and methylation of its promoter in FGC cases with MSI. This suggests that the mechanism of inactivation of hMLH1 is epigenetic and that there are other genes responsible for FGC.

Methylation of the hMLH1 promoter in familial gastric cancer with microsatellite instability

Microsatellite instability (MSI), which is recognized as an important mechanism in tumorigenesis, has been reported in familial gastric cancers (FGC). However, genetic defects responsible for this phenotype, that is, mutations in mismatch-repair genes such as hMLH1 and hMSH2, have not been detected in most FGC cases. Earlier studies have shown that the promoter region of the hMLH1 gene was methylated in some sporadic colorectal and endometrial cancers. To determine how FGC acquire MSI, we examined the MSI status, hMLH1-protein expression and methylation status of the hMLH1-promoter region in FGC cases. Out of 9 cancers, 6 from 8 FGC kindreds showed MSI at one or more loci; no germline mutations in the hMLH1 or hMSH2 genes were detected; 4 cancers exhibiting MSI displayed aberrant hMLH1 expression: complete loss in one, decreased level in another, and partially staining pattern in the remaining 2. Methylation in the hMLH1-promoter region was found in these 4 cases. In contrast, the cancers displaying hMLH1-protein expression were not methylated in the hMLH1-promoter region. Our data show a significant association between the absence of hMLH1 expression and methylation of its promoter in FGC cases with MSI. This suggests that the mechanism of inactivation of hMLH1 is epigenetic and that there are other genes responsible for FGC.

A core promoter and a frequent single-nucleotide polymorphism of the mismatch repair gene hMLH1

The hMLH1 gene encodes a protein that is involved in the DNA mismatch repair system. The coding region of the hMLH1 gene has been known to be mutated in a subset of patients with hereditary nonpolyposis colorectal cancer (HNPCC). Our current research characterized the promoter region of the hMLH1 gene and searched for mutations correlating to HNPCC. Utilizing the oligo-capping method, major transcription start sites of the hMLH1 gene were mapped at two locations. The core promoter region of about 180 bp was determined by the luciferase assay of serial deletion mutants. Although we did not find any pathogenic mutation in the hMLH1 promoter region by PCR-SSCP, we found a single-nucleotide polymorphism at position -93 nt from the adenine residue of the start codon. By PCR-RFLP analysis with Pvu II for this polymorphism, we detected LOH in four tumors from three patients. An easy detection of this polymorphism with PCR-RFLP and high incidence ( approximately 50%) of informative cases make this polymorphism a suitable marker for the detection of hMLH1 allelic losses.

Two short sequences have positive effects on the human p27Kip1 gene transcription

The cyclin-dependent kinase (Cdk) inhibitor p27Kip1 plays an important role in the progression from G1 to S phase in the cell cycle. To study the activities of its promoter and other regulatory elements, we have cloned and characterized the 5'-flanking region of the human p27Kip1 gene. This region, about 3kb in length, is GC-rich and shares homology with that of the mouse p27Kip1 gene. Transcription start points (tsp) determined by the oligo-capping method are mapped in two regions, the cluster I (-479 to -403) and cluster II (-280 to -273). The cluster I was the primary functional site in transcription initiation. The luciferase activities of serial deletion mutants indicated that two short sequences (-581 to -557 and -556 to -526) had positive effects on transcription. The gel shift assay showed that factors in HeLa nuclear extract bound to these sequences. Sp1 was the major binding factor to the sequence of -556 to -526, wheres yet unidentified positive factors bound to the sequence of -581 to -557.

Determinants of nitrogen dioxide concentrations in indoor ice skating rinks

OBJECTIVES

The combination of poor ventilation and fuel-powered ice resurfacers has resulted in elevated nitrogen dioxide (NO2) concentrations in many indoor ice skating rinks. This study examined the factors influencing concentrations and the effects of various engineering controls in ice rinks with different resurfacer fuels.

METHODS

Indoor NO2 concentrations were measured in 19 enclosed ice skating rinks over 3 winters by means of passive samplers, with 1-week average measurements during the first winter pilot study and single-day working-hour measurements in the final 2 winters. Personal exposures to drivers also were assessed during the last winter.

RESULTS

Rinks in which propane-fueled resurfacers were used had a daily mean indoor NO2 concentration of 206 ppb, compared with 132 ppb for gasoline-fueled and 37 ppb for electric-powered resurfacers. Engineering controls, such as increased ventilation and resurfacer tuning, reduced NO2 concentrations by 65% on average, but outcomes varied widely, and concentrations increased in subsequent months.

CONCLUSIONS

Electric ice resurfacers, increased ventilation, or emission control systems are recommended to protect the health of workers and patrons, with surveillance programs proposed to track implementation and maintain an observer effect.

Human megasatellite DNA RS447: copy-number polymorphisms and interspecies conservation

We previously isolated a novel 4.7-kb RS447 sequence, which tandemly repeated approximately 50-70 copies and resided on human chromosome 4p15 (M. Kogi et al., 1997, Genomics 42: 278-283). Another tandem array (or arrays) of several RS447 copies was hereby identified on the distal part of chromosome 8p. To analyze copy-number polymorphisms of the RS447 repeats, genomic DNA samples of eight nonkindred Japanese were subjected to pulsed-field gel electrophoresis. The copy numbers of the RS447 tandem arrays on 4p15 varied drastically from allele to allele and ranged from approximately 34 to 94 copies. All eight Japanese subjects were apparently heterozygous for the RS447 copy number, and 12 copy-number-different alleles have been at least clearly distinguished. The RS447 tandem repeats were thus found to be hypervariable and highly polymorphic in a human population. The RS447 sequences, however, do not appear to be either "selfish" or "junk" DNA. The unit size and sequence of RS447 were found to be very similar between members in the human genome. The unit size of 4746 bp comprises a putative open reading frame of 1590 bp. The RS447 sequence was well conserved in all the tested mammalian species. The head-to-tail tandem repetitive structure in the RS447 homologs was also confirmed in those species. The RS447 sequence is, therefore, considered to consist of a new class of tandemly repeated satellite DNA elements in the mammalian genome, which may thus be called "megasatellite DNA."

The Boston residential nitrogen dioxide characterization study: classification and prediction of indoor NO2 exposure

Many epidemiological studies have used house characteristics associated with indoor sources as simplified proxies for personal nitrogen dioxide (NO2) exposure. Stove type and presence of a pilot light often been used as the two key characteristics, but significant overlaps have remained in the NO2 concentrations in the exposed and unexposed groups. This has contributed to inconsistencies in epidemiological findings, due to potential misclassification of exposure. In this study, other possible proxies were analyzed by cross-table analyses and were investigated in terms of improvements in both classification and predictive power. Adding building type to the above two proxies resulted in 0-5% of households with concentrations overlapping the observed range for the opposing stratum, compared with 22-42% for the two-proxy model. In spite of this performance, the predictive power of regression models for indoor NO2 was not improved by the addition of the third proxy, and the potential sample population was significantly limited. Using these analytical methods to choose descriptive proxies and evaluate the tradeoffs in their implementation can help epidemiological studies improve their designs and therefore optimize the robustness of their conclusions.

Promoter analysis of the human mismatch repair gene hMSH2

The human DNA mismatch repair gene homologue hMSH2 is involved in hereditary nonpolyposis colorectal cancer. We isolated and characterized the 5' upstream region, about 4.4kbp, of the hMSH2 gene. This region contains CpG islands and a number of elements involved in constitutive expression, but there is no TATA-box nearby the transcription start points. This is the typical structure for many promoters of housekeeping genes. Alu sequences and mononucleotide repeats are clustered in this region and there are two transcription start points. Deletion analysis revealed that less than 300bp was sufficient to initiate transcription. Although no mutation that influences promoter activity of this region was found, a polymorphism was detected by PCR-RFLP analysis. Because informative cases (C/T heterozygous) were relatively high ( approximately 30%), this polymorphism is suitable for a marker to examine allelic losses.

Impact of residential nitrogen dioxide exposure on personal exposure: an international study

Nitrogen dioxide (NO2) concentrations were measured during two-day winter periods in indoor and outdoor environments, and these concentrations were compared with simultaneously measured personal exposures in 18 cities in 15 countries around the world. Information was also gathered on activity patterns and household characteristics in order to determine the influences of these factors on personal exposures. All NO2 measurements were taken using passive filter badges. Personal exposures were found to vary greatly among the array of cities, with mean concentrations ranging between 11.0 ppb and 51.5 ppb. Personal NO2 exposures were more strongly correlated with indoor concentrations (r = 0.75) than with outdoor concentrations (r = 0.57) when all countries were considered simultaneously. Use of a gas stove in the home was the dominant activity influencing NO2 concentrations, with a 67% increase in mean personal NO2 exposure and an increase in indoor-outdoor ratios from 0.7 to 1.2 for participants using gas stoves, although preliminary evidence indicates the importance of combustion space heaters as well. These associations indicate the global nature of the correlation between personal NO2 exposures and indoor NO2 sources such as gas stoves or space heaters, demonstrating that this relationship is not dependent on country-specific parameters.

Isolation and characterization of the 5' region of the human mismatch repair gene hPMS1

The hPMS1 gene encodes a mutL homolog that is implicated in DNA mismatch repair and was found to be mutated in the germline of a patient with hereditary nonpolyposis colorectal cancer (HNPCC). To understand transcriptional regulation and to perform mutational analysis in the promoter region, we cloned and characterized the genomic sequence of the 5' region of the gene. hPMS1 has an intron upstream of the initiation codon. There were several transcripts with alternative splicing sites and multiple transcriptional start sites. The cloned 1.4-kbp fragment of the 5' region contains a CpG island but no TATA-boxes, typical for promoters of housekeeping genes. The promoter activity of the fragment was almost equal to that of the SV40 early promoter. Deletion analysis showed that about a 300-bp region was sufficient to initiate transcription. Although we searched for mutations in the hPMS1 promoter region in HNPCC kindreds, neither germline nor somatic mutations were detected. However, we found a highly informative polymorphism in the first exon that is useful for searching allelic losses because no polymorphic changes in hPMS1 have been reported previously.

Analysis of DNA from subjects found to be heterozygous for the haptoglobin-Johnson alpha gene

We found two rare Hp Johnson variant families (Hp2-Johnson type and Hp1-Johnson type) by PAGE. It was confirmed by SDS-PAGE that the haptoglobin molecules with the Hp Johnson variant consisted of alpha-2 or alpha-1 and alpha-3 subunits. Direct gene analysis of Hp Johnson heterozygous individuals using three endonucleases: EcoRI, HindIII and BamHI, showed a three-fold tandem repeat of the same 1.7-kb DNA fragment implicated in the Hp alpha-2 gene duplication, and this Hp-Johnson-specific extension was identified in two generations of the Hp2-Johnson and Hp1-Johnson families.

[Toxicity studies of landiolol hydrochloride (ONO-1101) (1). Single intravenous toxicity study in rats and dogs]

Single dose toxicity studies of landiolol hydrochloride (ONO-1101), a novel ultra short acting beta-blocker, were conducted in Sprague-Dawley (SD) rats and beagle dogs. ONO-1101 was administered intravenously at a dose level of 37.5, 75, 150 or 300 mg/kg to rats of both sexes and 25, 50 or 100 mg/kg to male dogs. In the rat study, 5/6 males in the 150 mg/kg group and all animals in the 300 mg/kg group died during or right after administration. Survivors in the 150 mg/kg group showed temporal hypoactivity, bradypnea, dyspnea, tremor, loss of righting reflex and reddish lacrimation up to 5 min after injection. One male in the 150 mg/kg group had a tendency of suppression on body weight gain. No effects on clinical signs and body weight gain were seen in the 75 mg/kg group or lower. Necropsy findings showed only red tear in the majority of the decedents. In the dog study, all animals died within 6 min after administration in the 100 mg/kg group, showed ataxic gait, rolling and tachypnea followed by bradypnea and gasping/apnea. Incontinence of urine, defecation and vocalization were also seen in each one of two animals before death. Temporal hypoactivity was seen 1 min after administration in the 50 mg/kg group. No clinical signs were seen in the 25 mg/kg group. ONO-1101 did not affect bodyweight or food consumption. Necropsy findings of the decedents showed no abnormalities. It is indicated that the minimum lethal doses are 150 mg/kg in rats and 100 mg/kg in dogs.

Association equilibrium of L-methamphetamine with serum albumin in various animal species

The association equilibrium of complex formation between serum albumin (bovine, rat, rabbit, guinea pig, horse, mouse and chicken) and L-methamphetamine (MAMP) was determined by the use of ultrafiltration to examine the effect of animal species on adsorption of L-MAMP to albmin. Serum albumin L-MAMP complexes had the same Scatchard plot patterns in all species tested. The binding parameters of each association equilibrium were estimated by Rosenthal's method. One kind of binding site and non-specific binding sites were distinguished in terms of the association equilibrium between each serum albumin and L-MAMP in all species tested.

Analysis of the affinity of each haptoglobin polymer for hemoglobin by two-dimensional affinity electrophoresis

Using polyacrylamide gel electrophoresis we have often encountered a decrease in the high molecular weight polymers of haptoglobin 2-1 in the serum of patients after transfusion and with hemolytic diseases. Using two-dimensional affinity electrophoresis we have attributed this phenomenon to the high affinity of high molecular weight polymers of the haptoglobin 2-1 for hemoglobin.

Binding of methamphetamine to serum albumin in various species in vitro

While drugs from experimental animals provide very important information, it is also true that data differ from species to species, and that data from experimental animals cannot be applied directly to humans. The binding parameters of serum albumin from various animal species and methamphetamine were investigated in vitro by the Scatchard method. The Scatchard plots for the binding of serum albumin and methamphetamine were classified into three patterns: straight lines for human and rat serum albumin; downwardly convex curves for bovine and rabbit serum albumin; and upwardly convex curves for horse, mouse and chicken serum albumin. Hill coefficients were calculated for binding in which the Scatchard plots were upwardly convex curves and for guinea pig serum albumin. The results suggested the existence of positive cooperativity between the methamphetamine binding sites on serum albumin from the horse, mouse, chicken and guinea pig. Furthermore, the process of methamphetamine binding to human serum albumin appears to differ from the process for all experimental animals except the rat, and there are also differences between the binding processes in the various experimental animals.

Comparison of two-photon excitation laser scanning microscopy with UV-confocal laser scanning microscopy in three-dimensional calcium imaging using the fluorescence indicator Indo-1

Two-photon excitation laser scanning fluorescence microscopy (2p-LSM) was compared with UV-excitation confocal laser scanning fluorescence microscopy (UV-CLSM) in terms of three-dimensional (3-D) calcium imaging of living cells in culture. Indo-1 was used as a calcium indicator. Since the excitation volume is more limited and excitation wavelengths are longer in 2p-LSM than in UV-CLSM, 2p-LSM exhibited several advantages over UV-CLSM: (1) a lower level of background signal by a factor of 6-17, which enhances the contrast by a factor of 6-21: (2) a lower rate of photobleaching by a factor of 2-4; (3) slightly lower phototoxicity. When 3-D images were repeatedly acquired, the calcium concentration determined by UV-CLSM depended strongly on the number of data acquisitions and the nuclear regions falsely exhibited low calcium concentrations. probably due to an interplay of different levels of photobleaching of Indo-1 and autofluorescence, while the calcium concentration evaluated by 2p-LSM was stable and homogeneous throughout the cytoplasm. The spatial resolution of 2p-LSM was worse by 10% in the focal plane and by 30% along the optical axis due to the longer excitation wavelength. This disadvantage can be overcome by the addition of a confocal pinhole (two-photon excitation confocal laser scanning fluorescence microscopy), which made the resolution similar to that in UV-CLSM. These results indicate that 2p-LSM is preferable for repeated 3-D reconstruction of calcium concentration in living cells. In UV-CLSM, 0.18-mW laser power with a 2.6-phi pinhole (in normalized optical coordinate) gives better signal-to-noise ratio, contrast and resolution than 0.09-mW laser power with a 4.9-phi pinhole. However, since the damage to cells and the rate of photobleaching is substantially greater under the former condition, it is not suitable for repeated acquisition of 3-D images.

Estimation of CO exposure of road construction workers in tunnel

Carbon monoxide (CO) level in three different tunnels in Boston area have been measured during rush hour periods, and expected CO exposure of construction workers who possibly work there was also estimated. CO levels in these tunnels have been measured at outside of a car running through the tunnels. The data collected in this study include vehicle speed, length of tunnels and traffic volume. In addition, structure of each tunnel was investigated. These data were used to estimate relationship between CO level and the distance of sampling points from entrance/exit of each tunnel. CO concentration in each tunnel was distributed in the range of 5 ppm-42 ppm, and linear relationship between CO concentration and distance from entrance/exit has been observed. This study had been held from April 1989 to May 1989 in Boston, MA, USA.

Determination of intermediates of hemoglobin-haptoglobin complex of haptoglobin polymers by "Crossed hemoglobin electrophoresis"

We designed a "crossed hemoglobin electrophoresis" to be able to detect the intermediates of a hemoglobin-haptoglobin complex without the need for the purification step of haptoglobin molecules. Native polyacrylamide gel electrophoresis was performed as the first dimensional electrophoresis followed by a cross to hemoglobin as the second dimensional electrophoresis. Using this method, we found that a number of intermediates of normal Hp 2-2, Hp 2-1 polymers, particularly those from the trimer to the pentamer, were detected on a polyacrylamide gel. Each of their polymers combined to the hexamer with at least an equimolar content of hemoglobin. In the process of detecting the haptoglobin serotype of more than 10,000 patients for the clinical utilization of quantitative analytical data, we observed two haptoglobin variants, the Hp Johnson and a haptoglobin serotype similar to the Carlberg type. Using our crossed hemoglobin electrophoresis, we also detected the capacity for combining with hemoglobin of each polymer of these variants.

Latent high jugular bulb: case report and significance of neck compression test

High jugular bulb is a vascular anomaly seen in the middle ear. In typical cases, the jugular bulb is easily observed through the tympanic membrane. We report here 3 patients with nontypical high jugular bulb. Their tympanic membranes were almost normal but protruded externally with pulsation when their necks were compressed. Computed tomography (CT) revealed jugular bulb protrusion into the tympanic cavities. We propose that this condition be named 'latent high jugular bulb'. Neck compression easily detects this condition and may also be useful in the detection of other disorders of the middle ear that are related to the venous system.

Determinations of personal carbon monoxide exposure and blood carboxyhemoglobin levels in Korea

Determinant factors for personal carbon monoxide (CO) exposures were sought in Korea, where CO poisoning has been a major public health problem due to coal briquette (Yeontan) combustion for space heating and cooking. Personal 24-hr CO exposures of 15 housewives were measured by CO passive samplers on 2 days of the week (Wednesday and Sunday). Blood samples were taken to measure carboxyhemoglobin (COHb) just after the exposure sampling. Average CO exposure and COHb level were 5.6 ppm and 2.4%, respectively. Personal CO exposures as well as COHb levels were significantly increased by the use of Yeontan, especially on a weekday. Carboxyhemoglobin levels were closely related to the time between blood collection and replacement of Yeontan: the closer the blood collection was to replace Yeontan, the higher the COHb levels were. Assuming a background COHb of 1.34%, COHb increased on average by 1.8% with a 24-hr personal CO exposure of 10 ppm. The relationship between CO exposure and COHb level was provided by simultaneous direct measurements in real environment, although a measurement of COHb at the end of exposure could not represent previous 24-hr exposure thoroughly.

[The effect of temocapril, an angiotensin-converting enzyme inhibitor with preferential biliary excretion, on experimental diabetic nephropathy]

Tempocapril is a novel angiotensin-converting enzyme (ACE) inhibitor which is preferentially eliminated via the biliary tract. To examine whether it has a protective effect in diabetic nephropathy like conventional ACE inhibitors which are eliminated via the kidney, a study was performed in streptozotocin-induced diabetic rats for 8 months. Male Wistar rats were divided into 4 groups (control rats, diabetic rats treated with temocapril at the doses of 5 mg/l or 15 mg/l of drinking water, and untreated diabetic rats). There was no significant difference in the blood glucose levels of the 3 diabetic groups. Administration of temocapril at both doses of 5 mg/l and 15 mg/l significantly reduced the blood pressure as well as the urinary excretion of albumin and N-acetyl-beta-D-glucosaminidase. However, significant suppression of glomerular basement membrane hypertrophy was only induced by treatment with temocapril at the dose of 15 mg/l. Elevated glomerular filtration rate and filtration fraction in diabetic rats were decreased by tempocapril at the dose of 15 mg/l, but not significantly. These results indicate that tempocapril has a protective effect on diabetic nephropathy like conventional ACE inhibitors.

[Identification of group C Streptococcus with Helix pomatia lectin in use for blood grouping]

The lectin anti-AHP (Helix lectin) obtained from the albumen gland of an edible snail, Helix pomatia, was used for the identification of group C streptococci. All 1,045 strains of group C streptococci (S. equisimilis, S. zooepidemicus, and S. dysgalactiae) were agglutinated with the Helix lectin, but none of the 12,264 strains of group A, 1,346 strains of group G, 330 strains of group B, and 121 strains of other streptococcal groups was not. A few strains of S. equisimilis which belongs to group C have on the cell surface specific T antigen of group A streptococci, but it did not affect the agglutination with Helix lectin. Some strains of S. milleri carrying or not carrying group G specific carbohydrate and S. sanguis with group H antigen were agglutinated with the Helix lectin (Anti-AHP). This suggests that terminal N-acetyl-D-galactsamine of the cell-wall carbohydrate of these bacteria reacts with the Helix lectin (Anti-AHP). Therefore, the Helix lectin is a very useful tool for identification of group C streptococci.

Carbon monoxide and nitrogen dioxide exposures in indoor ice skating rinks

Exposures to carbon monoxide (CO) and nitrogen dioxide (NO2) were determined in seven enclosed ice skating rinks and an outdoor rink. The uptake of CO was also determined by the difference in alveolar CO concentration of the non-smoking hockey players before and after games. Carbon monoxide concentrations in enclosed rinks ranged from 4 to 117 ppm and NO2 concentrations from 342 to 2729 ppb for 2 h hockey games. The CO uptakes were linearly related to the ambient CO concentrations. Alveolar CO of the hockey players increased on average by 0.53 ppm per 1 ppm CO exposure over 2 h. Considering the CO and NO2 levels currently measured in enclosed ice skating rinks, indoor air quality guidelines or standards should be established. It is recommended that 1 h maximum allowable limits of 20 ppm CO and 250 ppb NO2 be established.

A passive ozone sampler based on a reaction with iodide

A new passive sampler for ozone and its simple analytical system have been developed. Because it is small and sensitive, the sampler can be used for determining personal exposures to ozone and oxidants and for multilocation measurements. The sampler consists of an electrode, a spacer, and several layers of membrane filters and Teflon meshes. The electrode is a carbon paper disk coated with nylon-6 polymer and potassium iodide. The membrane filters are used to remove interferences. A sampling rate of ozone is controlled by the spacer and Teflon meshes. Iodine is liberated by an oxidation reaction of potassium iodide with ozone. The iodine is stabilized by forming a charge transfer complex with nylon-6 and is accumulated in the nylon-6 layer. The amount of iodine, which is proportional to the level of ozone exposure, is quantified by constant current coulometry. The discharge time of a galvanic battery is measured using the electrode as a positive electrode and a zinc plate as a counter electrode. A time-weighted average concentration of ozone is derived from the discharge time after exposing the electrode to ozone. The effects of various environmental conditions on the sampler's performance were investigated. The results indicated that the sampler showed a linear response to ozone exposure up to 1,450 parts per billion for every hour of use (ppb.hour). The minimum detectable exposure was about 400 ppb.hour. The effects of surface wind velocity, temperature, and humidity were small. However, a relative humidity below 20% resulted in an underestimation of the ozone concentration. Because the electrode requires no pretreatment and the analytical method is very simple, this method is suitable for large-scale studies of personal exposures to ozone and oxidants using multilocation measurements.

Paraoccupational exposures to lead and tin carried by electric-cable splicers

To test the hypothesis that electric-cable splicers contaminate their homes with lead and tin, nine splicers were matched with nine of their neighbors. House dust samples were collected in two areas within each home: a laundry room/dirty clothes area, and a composite sample from other areas in the house. Samples were analyzed by energy dispersive X-ray fluorescence for lead and tin (tin is a tracer to the occupational source of lead). The difference in the geometric mean lead concentrations in the laundry areas between the splicers' and neighbors' homes (1021 ppm and 390 ppm) was statistically significant (p < 0.025). The difference in concentrations from the other areas of the house (585 ppm and 329 ppm) was also significant (p < 0.05). Tin concentrations in house dust were very different between the two groups (p < 0.0005), suggesting that electric-cable splicers were contaminating their homes with lead and tin from work. Recommendations are included to prevent paraoccupational lead exposures by eliminating the pathways into the home. Another recommendation suggests that blood-lead levels be screened in children under the age of seven who live with electric-cable splicers.

[The relationship between serum leukotriene B4 and smoking]

Leukotriene B4 (LTB4), an arachidonic acid metabolite released by neutrophils, is involved in the regulation of the host immune response to antigenic stimulation. Furthermore, LTB4 affects the chemokinesis, aggregation, and enzyme release of neutrophils and stimulates activity of cytotoxic T cells, natural killer cells and suppressor T cells. On the other hand, smoking typically results in inflammatory stimulation of the lung, and long-term smoking can cause chronic stimulation. In this paper, we report the measurement of LTB4, IgG, IgA, IgM, IgD and IgE in sera of cigarette smokers who did not have an allergic reaction (group 1), non-smokers who also had no history of allergy (group 2) and non-smokers who had delicate allergic conditions (group 3). The mean LTB4 concentration in serum of group 1 was nearly 3.3-fold greater than in group 2 and 2-fold greater than in group 3, being 430 +/- 55 (Mean +/- S.D.), 130 +/- 22 and 220 +/- 14 pg/ml, respectively. Concentrations of IgG, IgA, IgM, IgD and IgE of all volunteers were in the normal healthy range. The mean concentration of IgE in the serum of group 1 did not change significantly within one day. It was 35 +/- 4 IU/ml in the morning, 34 +/- 4 IU/ml in the afternoon, 31 +/- 2 IU/ml in the evening and 32 +/- 4 IU/ml the next morning. But in group 3 the IgE concentration changed significantly within one day, being < 25 IU/ml in the morning, 97 +/- 7 IU/ml in the afternoon, 97 +/- 7 IU/ml in the evening and 25 +/- 14 IU/ml the next morning.(ABSTRACT TRUNCATED AT 250 WORDS)

Stiffening of connective tissue in elderly diabetic patients: relevance to diabetic nephropathy and oxidative stress

Limited joint mobility seen in diabetes mellitus is thought to be the result of stiffening of periarticular connective tissue, which is presumably derived from increased cross-linking of collagen related to advanced glycation end products. In this study the extent of the stiffening of connective tissue was measured by the passive extension angle of the metacarpophalangeal joints in 205 elderly diabetic patients. Association with diabetic nephropathy, with which advanced glycation end products have recently been demonstrated to increase, and metabolic abnormalities were also considered. The angle of the metacarpophalangeal joints was significantly correlated with age (r = -0.24, p < 0.01), and was significantly smaller in men than in women (p < 0.01). The angle demonstrated a decrease in association with diabetic retinopathy and nephropathy, and only the association with nephropathy was significant (p < 0.05). The angle was weakly, but significantly, correlated with serum thiobarbituric acid reactants as a measure of lipid peroxides (r = -0.15, p < 0.05), triglyceride (r = -0.20, p < 0.01) and HDL cholesterol (r = 0.19, p < 0.01), but not with blood glucose (r = 0.02), HbA1c (r = 0.06) or duration of diabetes (r = -0.05). In addition, the angle in 14 non-diabetic patients on haemodialysis was significantly (p < 0.05) smaller than that in age- and sex-matched normal subjects. Thus, it was indicated that the stiffening of connective tissue was associated with diabetic nephropathy, serum lipid peroxide and dyslipidaemia. Stiffening of connective tissue seems to be more affected by oxidative stress than non-enzymatic glycation per se.(ABSTRACT TRUNCATED AT 250 WORDS)

Protective effect of vitamin E supplementation on increased thermal stability of collagen in diabetic rats

Products similar to non-enzymatic glycation end products are known to arise from the interactions between proteins and lipid peroxides in vitro. In this study, we assessed the effect of vitamin E, which possibly modifies lipid peroxide, on advanced glycation end products or similar products in vivo by measuring the fluorescence and thermal rupture time of tail tendon collagen in streptozotocin-induced diabetic rats. The diabetic rats and non-diabetic rats were fed a vitamin E supplemented diet, and a control diet starting 3 days after the streptozotocin injection. After the 4-week treatment, the serum lipid peroxide levels expressed as thiobarbituric acid reactants in the diabetic rats on control diet (15.9 +/- 2.6 mumol/l[SEM]) were significantly (p less than 0.05) higher than in the non-diabetic rats (7.9 +/- 1.3 mumol/l on control diet and 3.3 +/- 0.4 mumol/l on supplemented diet), but the levels in the diabetic rats on supplemented diet (7.9 +/- 2.3 mumol/l) were reduced to the normal levels. No significant differences were found in serum glucose and glycated haemoglobin levels within the diabetic rats on control and supplemented diets. Both the fluorescence and thermal rupture time of collagen were significantly (p less than 0.05) increased in the diabetic rats on both diets compared with those in the corresponding non-diabetic rats. Although there was no significant difference in the collagen-linked fluorescence within the diabetic rats on control and supplemented diets, the thermal rupture time was significantly (p less than 0.01) shortened with supplemented diet (10.8 +/- 0.7 min on supplemented diet vs 15.0 +/- 0.7 min on control diet).(ABSTRACT TRUNCATED AT 250 WORDS)

No significant effect of vitamin E deficiency or supplementation on collagen-linked fluorescence in skin of diabetic rats

It is speculated that oxidative stress in vivo may have some influence on advanced, nonenzymatic, glycosylation end products. However, this has not been demonstrated yet. We assessed changes in collagen-linked fluorescence in the skin of nondiabetic and streptozotocin-induced diabetic rats fed three different diets for 4 weeks that could modify oxidative stress: vitamin E-deficient (D), vitamin E-supplemented (S), and control (C). The serum lipid peroxide level expressed as thiobarbituric acid (TBA) activity in diabetic rats on the S diet (9.6 +/- 1.0 [SE] nmol/L/mL) was significantly (P less than .01) lower than that in rats on the D diet (111.4 +/- 22.4), and similar to that in nondiabetic rats on the C diet (12.4 +/- 2.2). The collagen-linked fluorescence level was significantly (P less than .01) higher in diabetic rats than in nondiabetic rats, which corresponded to the serum glucose and glycosylated hemoglobin levels. However, there were no significant differences in the fluorescence levels among three groups classified by three different diets in both nondiabetic and diabetic rats (21.7 +/- 1.7 arbitrary U/mg collagen for D, 22.3 +/- 2.0 for C, and 22.8 +/- 2.5 for S in nondiabetic rats v 41.2 +/- 4.1 for D, 40.1 +/- 4.7 for C, and 39.3 +/- 3.5 for S in diabetic rats), despite significant changes in serum lipid peroxide levels. Consequently, there were no significant changes found in collagen-linked fluorescence levels in diabetic rats wherein oxidative stress was modified by vitamin E deficiency and supplementation.(ABSTRACT TRUNCATED AT 250 WORDS)

Possible participation of a prostaglandin E1 analogue in the aggravation of diabetic nephropathy

A relation between the progression of diabetic nephropathy and glomerular hyperfiltration has been speculated. We describe two cases of non-insulin-dependent diabetic males aged 55 and 59 years in whom diabetic nephropathy was aggravated during the administration of limaprost, a a prostaglandin E1 analogue with a vasodilatory action. We also observed a short-term effect of limaprost on renal hemodynamics in three cases with diabetic nephropathy. In case 1, one year after limaprost administration the serum albumin level fell from 3.6 to 2.6 g/dl and the serum creatinine level rose from 1.0 to 1.6 mg/dl. In case 2, 9 months after limaprost administration the serum albumin level fell from 3.6 to 2.9 g/dl and the serum creatinine level rose from 1.8 to 2.3 mg/dl. In the latter stages of limaprost administration, the downslopes of reciprocal serum creatinine against time appeared to be augmented in the two cases. After the 3-day administration of limaprost, the peripheral and renal blood flows, and the glomerular filtration rate (GFR) were observed to rise, but the filtration fraction (FF) and urinary protein output were elevated. Keeping in mind the pre-existing renal damage, the increases in GFR and FF suggested acceleration of compensatory glomerular hyperfiltration in less damaged surviving glomeruli. The sustained acceleration of hyperfiltration with long-term administration of limaprost as an exogenous vasodilatory prostaglandin was assumed to eventuate in the aggravation of diabetic nephropathy. Attention should be paid to drugs which increase GFR in patients with established diabetic nephropathy.

Wind velocity effects on sampling rate of NO2 badge

The effects of wind velocity on a sampling rate of a nitrogen dioxide (NO2) diffusive badge were experimentally determined using a turntable. The use of a turntable permits the collection of the large amounts of data that are needed for statistically reliable results at several wind velocities in one experiment. The regression model for the wind effect determined by these experiments was closely correlated with data previously gathered from experiments using wind tunnels. Experiments at two different relative humidities, 35% and 60%, were performed and analyzed by a simple least square regression model. A multi-regression model containing two independent variables, wind velocity and relative humidity, also was developed. The multi-regression model was useful at relative humidity between 20% and 60% and wind velocity between 0 and 7 meter per second (m/sec).

Beneficial effect of dibutyryl cyclic AMP (DBcAMP) on ischemic acute renal failure in the rat

To determine the effect of dibutyryl cyclic AMP (DBcAMP) on ischemic acute renal failure (IARF), that disorder was induced in male Wistar rats. After the animals were anesthetized with sodium pentobarbital (50 mg/kg, i.p.), the right kidney was removed and the left renal pedicle was clamped for 60 min. DBcAMP (5 mg/kg, i.p.) was given each 30 min before and after the renal pedicle clamping in half the dose each. Twenty-four hours after surgery, the levels of serum creatinine, BUN, serum potassium, and FENa% were significantly less elevated; and the total urine volume was significantly less decreased for 24 h in the group of IARF given DBcAMP than in the group of IARF alone. The elevation in Ca2+ content of the renal cortex was also significantly lower in the group of IARF given DBcAMP than in the group of IARF alone. These data indicate that DBcAMP can produce a beneficial effect on experimentally induced IARF. Since the intracellular accumulation of Ca2+ has been reported to be a potentially harmful factor in the development of IARF, it is suggested that the effect of DBcAMP on IARF can be in part due to an inhibition of the intracellular accumulation of Ca2+ in the kidney.

Contribution of hyperglycemia and renal damage to urinary C-peptide clearance in non-insulin-dependent diabetic patients

The variation of urinary C-peptide clearance in relation to hyperglycemia and renal damage was evaluated in 57 patients with non-insulin-dependent diabetes mellitus (NIDDM) with and without overt proteinuria, 14 nondiabetic patients with renal disease (RD) and 18 healthy control subjects. Urinary C-peptide clearance expressed as the ratio of urinary C-peptide to creatinine clearance (CCP/CCR) in the fasting state did not differ in control subjects and RD patients, and was higher equally in NIDDM patients with and without proteinuria. In NIDDM patients without overt proteinuria, urinary levels of C-peptide, beta 2-microglobulin (B2M), N-acetyl-beta-D-glucosaminidase (NAG) and albumin as well as CCP/CCR ratio all decreased significantly with short-term glycemic control (P less than 0.05). Despite a wide range of CCP/CCR ratio (0.07-0.73), a weak but significant correlation (r = 0.56, P less than 0.005) was found between fasting serum and urinary C-peptide levels in NIDDM patients. These results suggest that urinary C-peptide may easily be affected by hyperglycemia per se rather than renal damage, while urinary B2M, NAG and albumin may be affected by both hyperglycemia and renal damage. When the urinary C-peptide level is interpreted, the influence of hyperglycemia on it must be taken into consideration.