Short-term outcome of total knee replacement in a patient with hemophilia: A case report and review of literature

BACKGROUND

Hemophilia A is a rare inherited bleeding disorder caused by mutations in the factor VIII gene. This clotting factor plays an intrinsic role in the blood coagulation pathway. Patients with hemophilia may develop orthopedic manifestations such as hemarthrosis, but multiple malunion of fractures over the knee is rare and difficult to treat.

CASE SUMMARY

We report a patient with hemophilia A who developed severe knee osteoarthritis along with fracture malunion and nonunion. Total knee replacement was performed using a custom-made modular hinged knee prosthesis (cemented) equipped with extended distal and proximal stems. At 3 years’ follow-up, the patient exhibited excellent clinical function and remained satisfied with the surgical outcome. Surgical intervention was accompanied by rigorous coagulation factor replacement.

CONCLUSION

This case highlights various unique scenarios specific to individuals with hemophilia and fracture deformity.

[Etiologic characteristics of Shigella sonnei strains isolated from some areas of Guangdong province and Guangxi Zhuang Autonomous Region of China, 2014-2016]

Objective: To investigated the etiologic characteristics of Shigella (S.) sonnei strains causing outbreaks and sporadic cases in some areas of Guangdong province and Guangxi Zhuang Autonomous Region during 2014-2016. Methods: Fourteen S. sonnei strains isolated from outbreaks and 6 S. sonnei strains from sporadic cases from Guangdong and Liuzhou of Guangxi Zhuang Autonomous Region were tested for antimicrobial resistance and analyzed by pulsed-field gel electrophoresis (PFGE). Six typical strains were selected for whole genome sequencing typing and compared with 51 strains isolated both at home and abroad from NCBI genome database. Results: The antibiotic resistance test indicated the isolates had high resistance rate to ampicillin, tetracycline, gentamicin, trimethoprim/sulfamethoxazole and nalidixic acid, while sensitive to azithromycin, chloromycetin and imipenem. PFGE showed high similarity (93.2%) among the strains isolated from different areas. The whole genome sequencing analysis also revealed that all the typical strains were clustered into a same evolution branch, close to some strains from Korea. Conclusions: The S. sonnei strains isolated from some areas of Guangdong and Guangxi Zhuang Autonomous Region showed high resistance to commonly used antibiotics, but they were sensitive to azithromycin, chloramphenicol and imipenem. The isolates in this study also showed similar PFGE patterns and close phylogenic evolution.

Quercetin ameliorates LPS-induced inflammation in human peripheral blood mononuclear cells by inhibition of the TLR2-NF-κB pathway

Quercetin, a dietary flavonoid abundant in fruits, vegetables, and herbs, presents various pharmacological effects. This study aimed to investigate the anti-inflammatory effect and the underlying mechanism of quercetin in lipopolysaccharide (LPS)-stimulated human peripheral blood mononuclear cells (PBMCs). Cell viability was measured by the Cell Counting Kit-8 assay. The mRNA expression of Toll-like receptor 2 (TLR2) was assessed by quantitative real-time polymerase chain reaction. Inflammatory cytokine secretions and nuclear factor (NF)-kB levels were analyzed by enzyme-linked immunosorbent assay. Our findings showed that quercetin significantly reduced LPS-induced cytotoxicity in human PBMCs. Quercetin suppressed the secretion of tumor necrosis factor-a, interleukin (IL)-1b, and IL-6 in LPS-stimulated human PBMCs. Moreover, quercetin reduced the LPS-induced increase in the expression of TLR2 mRNA and decreased the NF-kB concentration in LPS-stimulated human PBMCs. The data indicates that quercetin plays an important role in LPS-induced inflammation in human PBMCs via suppression of the TLR2-NF-kB pathway.

Building-Related Symptoms among Office Employees Associated with Indoor Carbon Dioxide and Total Volatile Organic Compounds

This study investigated whether sick building syndrome (SBS) complaints among office workers were associated with the indoor air quality. With informed consent, 417 employees in 87 office rooms of eight high-rise buildings completed a self-reported questionnaire for symptoms experienced at work during the past month. Carbon dioxide (CO2), temperature, humidity and total volatile organic compounds (TVOCs) in each office were simultaneously measured for eight office hours using portable monitors. Time-averaged workday difference between the indoor and the outdoor CO2 concentrations (dCO2) was calculated as a surrogate measure of ventilation efficiency for each office unit. The prevalence rates of SBS were 22.5% for eye syndrome, 15.3% for upper respiratory and 25.4% for non-specific syndromes. Tiredness (20.9%), difficulty in concentrating (14.6%), eye dryness (18.7%) were also common complaints. The generalized estimating equations multivariate logistic regression analyses showed that adjusted odds ratios (aORs) and 95% confidence interval (CI) per 100 ppm increase in dCO2 were significantly associated with dry throat (1.10, 95% CI=(1.00-1.22)), tiredness (1.16, 95% CI=(1.04-1.29)) and dizziness (1.22, 95% CI=(1.08-1.37)). The ORs for per 100 ppb increases in TVOCs were also associated with upper respiratory symptoms (1.06, 95% CI=(1.04-1.07)), dry throat (1.06, 95% CI=(1.03-1.09)) and irritability (1.02, 95% CI=(1.01-1.04)). In conclusion, the association between some SBS symptoms and the exposure to CO2 and total VOCs are moderate but may be independently significant.

Sequential intravenous/oral moxifloxacin monotherapy for complicated skin and skin structure infections: a meta-analysis of randomised controlled trials

OBJECTIVES

The presumed superiority of moxifloxacin for the treatment of complicated skin and skin structure infections (cSSSIs) is based on laboratory data, but has not yet been established on clinical grounds. The aim of this meta-analysis was to evaluate the efficacy and safety of sequential intravenous (i.v.)/oral (p.o.) moxifloxacin monotherapy for the treatment of cSSSIs.

METHODS

Randomised controlled trials (RCTs) published prior to November 2012 were systematically retrieved from PubMed, MEDLINE, EMBASE, ScienceDirect, ClinicalTrials.gov and the Cochrane Central Register of Controlled Trials. Finally, a meta-analysis of all RCTs eligible for inclusion criteria was performed.

RESULTS

Three studies that enrolled 2255 patients were included in the meta-analysis. There were no statistically significant differences between patients given moxifloxacin and those given other antibiotics with regard to clinical success rate [1667 patients, odds ratio (OR) = 0.83, 95% confidence interval (CI) 0.63 to 1.09, p = 0.18], bacteriological success rate (bacteriological success rates: 1502 patients, OR = 0.90, 95% CI 0.68-1.18, p = 0.45) or mortality (2207 patients, OR = 1.96, 95% CI 0.79-4.88, p = 0.15). Significantly, more overall adverse events (AEs) were associated with the use of moxifloxacin than with other antibiotics (2207 patients, OR = 1.21, 95%CI 1.00-1.45, p = 0.04). However, there was no statistically significant difference in the occurrence of drug-related AEs, serious AEs or serious drug-related AEs between patients given moxifloxacin and those given other antibiotics.

CONCLUSION

Sequential i.v./p.o. moxifloxacin monotherapy is an effective and relatively safe option for the treatment of cSSSIs. Other benefits of moxifloxacin may make it a more viable option compared with the currently used regimens.

Efficacy of gradual pressure-decline compressing stockings in Asian patients with lower leg varicose veins: analysis by general measurements and magnetic resonance image

AIM

Most applications of gradual pressure-decline compressing stockings (GPDCS) are used in the United States and Western European countries, with over a decade of clinical experiments. Up to know, there is no standard establishment of gradual pressure-decline compressing stockings for Asian patients with venous insufficiency and varicose vein formations.

METHODS

We collected data on volunteer candidates of varicose vein for general measurements and assessments and magnetic resonance imaging (MRI) by non-contrast enhanced MRV techniques, and for post processing data analysis.

RESULTS

Clinical use of GPCDS provide a mild to moderate improvement in the varicose vein conditions of patients with deep venous insufficiency by improving their deep vein circulation, by general measurements; recording major symptoms and complaint; comfort and stretching/flexibility to the candidates after using GPDCS; and area changes/flow velocity changes/available hemoglobin changes in deep veins monitored by MRI.

CONCLUSION

The benefits and data collected in these results may help in developing compression stockings standards in Taiwanese and Asian countries, and to establishing criterias for product sizes, compression levels, and related parameters.

White blood cell subsets are associated with carotid intima-media thickness and pulse wave velocity in an older Chinese population: the Guangzhou Biobank Cohort Study

Cross-sectional associations between white blood cell (WBC) count, lymphocyte and granulocyte numbers, and carotid intima-media thickness (IMT) and brachial-ankle pulse wave velocity (PWV) were examined in a novel older Chinese community sample. A total of 817 men and 760 women from a sub-study of the Guangzhou Biobank Cohort Study had a full blood count measured by an automated hematology analyzer, carotid IMT by B-mode ultrasonography and brachial-ankle PWV by a non-invasive automatic waveform analyzer. Following adjustment for confounders, WBC count (β=0.07, P<0.001) and granulocyte (β=0.07, P<0.001) number were significantly positively related to PWV, but not lymphocyte number. Similarly, WBC count (β=0.08, P=0.03), lymphocyte (β=0.08, P=0.002) and granulocyte (β=0.03, P=0.04) number were significantly positively associated with carotid IMT, but only the association with lymphocyte count survived correction for other cardiovascular risk factors. In conclusion, higher WBC, particularly lymphocyte and granulocyte, count could be used, respectively, as markers of cardiovascular disease risk, measured through indicators of atherosclerosis and arterial stiffness. The associations for WBC count previously observed by others were likely driven by higher granulocytes; an index of systemic inflammation.

Arterial stiffness and left-ventricular diastolic dysfunction: Guangzhou Biobank Cohort Study-CVD

Brachial-ankle pulse wave velocity (baPWV), a marker of arterial stiffness, is an established cardiovascular risk factor of ventricular stiffening. We studied the association of baPWV with left-ventricular (LV) diastolic function in a sub-study of the Guangzhou Biobank Cohort Study. In all, 378 Chinese subjects with a normal ejection fraction (>50%) had baPWV measurement by a noninvasive automatic waveform analyser, carotid intima-medial thickness (IMT) measurement by B-mode ultrasonography and cardiac diastolic function assessment by echocardiography. After adjusting for age, both baPWV and IMT were associated with LV mass index, posterior wall end-diastolic thickness and inter-ventricular end-diastolic thickness, but only baPWV was associated with deceleration time, atrial flow velocity and E/A ratio. Multivariable linear regression model showed that baPWV and mean arterial pressure, but not IMT, were significantly associated with E/A ratio (β=-0.02, P=0.03 and β=-0.36, P=0.02, respectively). The receiver operator characteristic curve showed that baPWV was better than pulse pressure or mean arterial pressure to detect LV diastolic dysfunction (E/A<1.0). Our study suggested that increased baPWV might be an independent risk factor or marker for diastolic dysfunction. Early detection of an intervention on increased baPWV may be important for prevention of cardiac diastolic dysfunction.

Determination of particulate-bound formaldehyde from burning incense by solid phase microextraction

This work studied the feasibility of using a solid phase microextraction (SPME) fiber for sampling and analysis of gaseous formaldehyde as well as particulate-bound formaldehyde from burning Chinese incense. The SPME fiber with PDMS/DVB coating were partially coated with o-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine hydrochloride (PFBHA), and used for sampling formaldehyde. The sampling rate for formaldehyde and its dependence on temperature, relative humidity and sampling time were observed. The same PFBHA treated fibers were, in parallel, exposed to incense burning smoke with pre-filtration and without pre- filtration for 0.5-1 min. The NIOSH method 2541 using an XAD-2 tube at a flow rate of 0.1 Lpm was also applied for sampling simultaneously. The results demonstrate that commercially available PDMS/DVB fibers partially coated with PFBHA are capable of sampling the gas phase of formaldehyde as well as particulate-bound formaldehyde. The determined level of formaldehyde was close to the result obtained by the NIOSH method 2541. However, a reduction of the fiber's formaldehyde loading capacity in the aerosol sampling in comparison with gas sampling was noticed. This indicates that the particulate characteristics, and their bound chemicals other than formaldehyde may influence the maximum loading capacity of formaldehyde, and some characteristic particulates in high concentrations may even deteriorate the fiber coating.

Alteration of bone cell function by RANKL and OPG in different in vitro models

BACKGROUND

Receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG) are well-documented potent regulators of osteoclast development. However, their effects in mature bone cells and in organ cultures have not been well studied. It is uncertain whether their activities in different experimental models are comparable.

MATERIALS AND METHODS

RANKL and OPG were evaluated for their activities in mouse calvarial organ cultures, mouse bone marrow cultures, isolated rat mature osteoclast assays and rat primary osteoblast cultures. Results In murine calvarial organ culture, both muRANKL (> or = 10 ng mL(-1)) and rRANKL (> or = 100 ng mL(-1)) significantly stimulated (45)Ca release, while OPG (> or = 50 ng mL(-1)) was an inhibitor of bone resorption. Meanwhile, [(3)H]-thymidine incorporation in this assay was also modulated (indicating proliferation increases in the osteoblast lineage of cells) although these peptides had no direct effect on [(3)H]-thymidine incorporation in isolated osteoblast assays. In mouse bone marrow cultures, muRANKL (> or = 1 ng mL(-1)) and rRANKL (> or = 5 ng mL(-1)) significantly stimulated osteoclastogenesis. The number of nuclei per osteoclast was also significantly increased. OPG strongly inhibited this index, with over 90% suppression at 1 ng mL(-1). Both muRANKL (10 ng mL(-1)) and rRANKL (100 ng mL(-1)) stimulated, while OPG (10 ng mL(-1)) inhibited osteoclast activity in isolated mature osteoclast assays.

CONCLUSION

The current study demonstrated that bone resorption modulated by RANKL and OPG, in murine calvarial organ culture, leads to changes in osteoblast proliferation, suggesting a feedback mechanism from osteoclasts to osteoblasts. In addition, it was found that RANKL and OPG have more potent effects on osteoclastogenesis than on the activity of mature osteoclasts.

Oxidative DNA damage estimated by urinary 8-hydroxydeoxyguanosine and indoor air pollution among non-smoking office employees

This study investigated whether urinary 8-hydroxydeoxyguanosine (8-OHdG), a biomarker of oxidative stress, was associated with indoor air quality for non-smokers in high-rise building offices. With informed consents, urine samples from 344 non-smoking employees in 86 offices were collected to determine 8-OHdG concentrations. The concentrations of carbon dioxide (CO(2)) and total volatile organic compounds (TVOCs) in each office and outside of the building were simultaneously measured for eight office hours. The average workday difference between indoor and outdoor CO(2) concentrations (dCO(2)) was used as a surrogate measure of the ventilation efficiency for each office unit. The CO(2) levels in the offices ranged 467-2810ppm with a mean of 1170ppm, or 2.7 times higher than that in the outside air. The average urinary 8-OHdG levels among employees increased from 3.10 micro g/g creatinine, for those at the lowest tertile levels of both dCO(2) and TVOCs, to 6.27 micro g/g creatinine, for those at the highest tertile levels. Multivariate logistic regression analysis showed that the risk of having the urinary 8-OHdG level of greater than the median, 4.53 micro g/g creatinine, for participants was increased significantly at the highest tertile dCO(2) level of >680ppm (odds ratio (OR)=3.37, 95% confidence interval (CI)=1.20-9.46). The effect was significant at the middle tertile TVOCs level of 114-360ppb (OR=2.62, 95% CI=1.43-4.79), but not at the highest tertile. Inadequate ventilation in office increases the risk of building-related oxidative stress in non-smoking employees.

Oxidative stress associated with indoor air pollution and sick building syndrome-related symptoms among office workers in Taiwan

This study investigated whether sick building syndrome (SBS) complaints and indoor air pollution for office workers are associated with oxidative stress indicated by urinary 8-hydroxydeoxyguanosine (8-OHdG). With informed consent, 389 employees in 87 government offices of 8 high-rise buildings in Taipei city completed self-reported questionnaires on SBS complaints at work in the past month. Urinary 8-OHdG was determined for each study participant and on-site air pollutants were measured for each office in both indoor and outdoor air. The results showed that urinary 8-OHdG had significant associations with volatile organic compounds and carbon dioxide levels in offices, and with urinary cotinine levels. The mean urinary 8-OHdG level was also significantly higher in participants with SBS symptoms than in those without such complaints (6.16 vs. 5.45 mug/g creatinine, p = .047). The mean 8-OHdG increased as the number of SBS symptoms increased. The multivariate logistic regression analyses showed that the adjusted odds ratios (OR) in relation to micrograms per gram creatinine increase in 8-OHdG were statistically significant for eye dryness (1.12), upper respiratory syndrome (1.17) with particularly nose itching (1.25), sneezing (1.51), dry throat (1.21), skin dryness (1.31), and dizziness (1.19). This study indicates that the 8-OHdG level was significantly associated with SBS complaints after controlling for air pollution and smoking. Whether the 8-OHdG can be used as an effective predictor for SBS symptoms deserves further study.

Preptin, another peptide product of the pancreatic beta-cell, is osteogenic in vitro and in vivo

Several hormones that regulate nutritional status also impact on bone metabolism. Preptin is a recently isolated 34-amino acid peptide hormone that is cosecreted with insulin and amylin from the pancreatic beta-cells. Preptin corresponds to Asp(69)-Leu(102) of pro-IGF-II. Increased circulating levels of a pro-IGF-II peptide complexed with IGF-binding protein-2 have been implicated in the high bone mass phenotype observed in patients with chronic hepatitis C infection. We have assessed preptin's activities on bone. Preptin dose-dependently stimulated the proliferation (cell number and DNA synthesis) of primary fetal rat osteoblasts and osteoblast-like cell lines at periphysiological concentrations (>10(-11) M). In addition, thymidine incorporation was stimulated in murine neonatal calvarial organ culture, likely reflecting the proliferation of cells from the osteoblast lineage. Preptin did not affect bone resorption in this model. Preptin induced phosphorylation of p42/p44 MAP kinases in osteoblastic cells in a dose-dependent manner (10(-8)-10(-10) M), and its proliferative effects on primary osteoblasts were blocked by MAP kinase kinase inhibitors. Preptin also reduced osteoblast apoptosis induced by serum deprivation, reducing the number of apoptotic cells by >20%. In vivo administration of preptin increased bone area and mineralizing surface in adult mice. These data demonstrate that preptin, which is cosecreted from the pancreatic beta-cell with amylin and insulin, is anabolic to bone and may contribute to the preservation of bone mass observed in hyperinsulinemic states such as obesity.

Modulation spectroscopy study of the effects of growth interruptions on the interfaces of GaAsSb/GaAs multiple quantum wells

The effects of growth interruption times combined with Sb exposure of GaAsSb/GaAs multiple quantum wells (MQWs) have been investigated by using phototransmittance (PT), contactless electroreflectance (CER) and wavelength modulated surface photovoltage spectroscopy (WMSPS). The features originated from different portions of the samples, including interband transitions of MQWs, interfaces and GaAs, are observed and identified through a detailed comparison of the obtained spectra and theoretical calculation. A red-shift of the interband transitions and a broader lineshape of the fundamental transition are observed from samples grown under Sb exposure compared to the reference sample grown without interruption. The results can be interpreted in terms of both increases in Sb content and mixing of Sb in the GaAs interface layers. An additional feature has been observed below the GaAs region in the samples with Sb treatment. The probable origin of this additional feature is discussed.

Lactoferrin and bone; structure–activity relationshipsThis paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin: Structure, Function, and Applications, and has undergone the Journal's usual peer review process

The maintenance of the mechanical integrity of the skeleton depends on bone remodeling, the well-coordinated balance between bone formation by osteoblasts and bone resorption by osteoclasts. The coupled action of osteoblasts and osteoclasts is regulated by the action of many local and circulating hormones and factors as well as central regulation by a neurological mechanism. We have previously shown that lactoferrin can promote bone growth. At physiological concentrations, lactoferrin potently stimulates the proliferation and differentiation of primary osteoblasts and acts as a survival factor. Lactoferrin also affects osteoclasts, potently inhibiting their formation. In vivo, local injection of lactoferrin results in substantial increases in bone formation and bone area. In a critical bone-defect model in vivo, lactoferrin was also seen to promote bone growth. The mitogenic effect of lactoferrin in osteoblast-like cells is mediated mainly through low-density lipoprotein-receptor protein-1 (LRP1), a member of the low-density lipoprotein-receptor-related proteins that are primarily known as endocytic receptors; however, LRP1 is not necessary for the anti-apoptotic actions of lactoferrin. Lactoferrin also induces the activation of p42/44 mitogen-activated protein kinase (MAPK) signalling and the PI3-kinase-dependent phosphorylation of Akt in osteoblasts. In this study, we examined other properties of lactoferrin and the way they affect osteogenic activity. The degree of glycosylation, iron-binding, and the structure–activity relationships indicate that lactoferrin maintains osteogenic activity in deglycosylated, holo, and apo forms, and in with various small fragments of the molecule. These data suggest that lactoferrin signals through more than 1 membrane-bound receptor to produce its anabolic skeletal effects, and that it signals through diverse pathways. We conclude that lactoferrin might have a physiological role in bone growth and healing and a potential therapeutic role as an anabolic factor in osteoporosis.

Phenotyping of individual pancreatic islets locates genetic defects in stimulus secretion coupling to Niddm1i within the major diabetes locus in GK rats

The major diabetes quantitative trait locus (Niddm1), which segregates in crosses between GK rats affected with spontaneous type 2-like diabetes and normoglycemic F344 rats, encodes at least two different diabetes susceptibility genes. Congenic strains for the two subloci (Niddm1f and Niddm1i) have been generated by transfer of GK alleles onto the genome of F344 rats. Whereas the Niddm1f phenotype implicated insulin resistance, the Niddm1i phenotype displayed diabetes related to insulin deficiency. Individual islets from 16-week-old congenic rats were characterized for insulin release and oxygen tension (pO(2)). In the presence of 3 mmol/l glucose, insulin release from Niddm1f and Niddm1i islets was approximately 5 pmol. g(-1). s(-1) and pO(2) was 120 mmHg. Similar recordings were obtained from GK and F344 islets. When glucose was raised to 11 mmol/l, insulin release increased significantly in Niddm1f and F344 islets but was essentially unchanged in islets from GK and Niddm1i. The high glucose concentration lowered pO(2) to the same extent in islets from all strains. Addition of 1 mmol/l tolbutamide to the perifusion medium further increased pulsatile insulin release threefold in all islets. The pulse frequency was approximately 0.4 min(-1). alpha-Ketoisocaproate (11 mmol/l) alone increased pulsatile insulin release eightfold in islets from Niddm1f, Niddm1i, and control F344 rats but had no effect on insulin release from GK islets. These secretory patterns in response to alpha-ketoisocaproate were paralleled by reduction of pO(2) in Niddm1f, Niddm1i, and control F344 islets and no change of pO(2) in GK islets. The results demonstrate that Niddm1i carries alleles of gene(s) that reduce glucose-induced insulin release and that are amenable to molecular identification by genetic fine mapping.

Treatment and outcome of Taiwanese patients with 6-pyruvoyltetrahydropterin synthase gene mutations

Ten cases of tetrahydrobiopterin (BH4) deficiency were identified in 1,337,490 newborns screened in a Chinese population in Taiwan. The high incidence of BH4 deficiency in the Taiwanese population may be explained by a founder effect, since all of the patients revealed 6-pyruvoyltetrahydropterin synthase gene mutations, and grouping N52S and P87S mutations together constituted 88.9% of the disease alleles. BH4 supplementation with restriction of high-protein foods gave control of plasma phenylalanine within normal range, and levodopa itself prevented seizure. However, the average intelligence quotient (IQ) score of these patients was only 76 +/- 14 (56-98). Statistically, the age of starting medication, including 5-hydroxytryptophan (5-HTP), was inversely correlated to IQ scores of these patients. We suggest the combination of BH4, levodopa and 5-HTP as the standard protocol to commence the treatment of BH4 deficiency as early as possible, although prenatal brain damage could have existed.

Luminol chemiluminescence in unbuffered solutions with a cobalt(II)-ethanolamine complex immobilized on resin as catalyst and its application to analysis

Using a heterogeneous catalyst, Co(II)-ethanolamine complex sorbed on Dowex-50W resin, the chemiluminescence (CL) of luminol in unbuffered or weakly acidic solution was studied in the presence of H2O2. The maximum luminol CL wavelength at pH 5.7 was 448 nm, 23 nm longer than that in a basic solution (pH 10.5). Three different ligands, mono-, di-, and triethanolamine, and six transition metal ions, Co(II), Cu(II), Ni(II), Mn-(II), Fe(II), and Fe(III) were compared by CL measurements. The CL intensity decreased in the order mono- > di- > triethanolamine and Co(II) > Cu(II) > Ni(II) > Fe-(III) > Mn(II) > Fe(II). This heterogeneous CL system was developed as H2O2 and glucose flow-through sensors. Detection limits (S/N = 3) of H2O2 and glucose using Dowex-50W-X4-Co(II)-monoethanolamine as catalyst are 1 x 10(-7) M and 1 x 10(-6) M, respectively. On the basis of the studies of the CL, fluorescence, UV-vis and ESCA spectra and the effect of dissolved oxygen in luminol solution, a mechanism for CL emission in unbuffered solution was considered as the formation of a superoxide radical ion during the decomposition of H2O2 catalyzed by the Co(II)-ethanolamine immobilized resin. Then the superoxide radical ion acted on luminol and the CL was emitted. The applications of the proposed method to determine H2O2 in rainwater without any special pretreatment and glucose in human urine and orange juice samples give satisfactory results.

Giant tear retinal detachment after laser in situ keratomileusis--a case report

A 42-year-old woman with a refractive error of -10.00S - 2.00C x 105 degrees in the right eye underwent laser in situ keratomileusis (LASIK) at our hospital. LASIK was performed using the Schwind excimer laser (Keratom Multiscan, Schwind, Kleinostheim, Germany) and Moria LSK--One manual microkeratome with a 130 microns ablation plate. The uncorrected visual acuity improved postoperatively, and the patient was very satisfied. However, nine months later, she complained of sudden loss of visual acuity in the right eye. Indirect ophthalmoscopy revealed a giant retinal tear extending from 10:00 to 2:00 o'clock position with retinal detachment and vitreous hemorrhage. We performed scleral buckling procedure (with silicone band encircling), vitrectomy, and fluid-gas exchange with air/SF6 mixture. The retina attached postoperatively and remained so during 3-month follow-up period, but cellophane maculopathy was noted.

[Determination of coenzyme Q and alpha-tocopherol in mouse plasma and tissue mitochondria by liquid chromatography with electrochemical detection]

A convenient and reliable liquid chromatographic method with electrochemical detection was developed for the simultaneous determination of reduced coenzyme Q(ubiquinol), oxidized coenzyme Q(ubiquinone) and alpha-tocopherol in various tissues. The compounds of interest were separated on a reverse-phase C18 column under the mobile phase of 7 g/L NaClO4 in ethanol-methanol-70% HClO4 (800:200:1, volume ratio) and detected simultaneously by using a series of detection cells. Electrochemical guard cell (upstream of the injector) was used for eliminating interference for mobile phase. Ubiquinones were reduced in the -550 mV conditioning cell (downstream of the column). The resultant ubiquinols and original ubiquinols and alpha-tocopherol existing in the sample were easily oxidized in the 150 mV analytical cell. The linear range of the compounds were from 5 micrograms/L to 200 micrograms/L with correlation coefficients from 0.9976 to 0.9999. The detection limits were from 0.23 microgram/L to 0.68 microgram/L. The method was applied satisfactorily to the simultaneous determination of the amounts of ubiquinol-9, ubiquinol-10, ubiquinone-9, ubiquinone-10 and alpha-tocopherol in mice plasma and tissue mitochondria.

Chemiluminescent flow-through sensor for 1,10-phenanthroline based on the combination of molecular imprinting and chemiluminescence

A functional polymer for the catalysis of the chemiluminescent reaction and molecular recognition ability of 1,10-phenanthroline was prepared based on the molecular imprinting method. The structural and catalytic roles of transition metal ion interactions were applied in the material design. A ternary complex, 4-vinylpyridine-Cu(II)-1,10-phenanthroline (2:1:1), was synthesized and used as a functional monomer. The ligand 1,10-phenanthroline in the ternary complex was the template used to form the molecularly imprinted polymer. Another monomer, styrene, and the cross-linking reagent divinylbenzene were copolymerized with the ternary complex. The polymer containing the ternary complex is an efficient catalyst for the decomposition of hydrogen peroxide. During the hydrogen peroxide decomposition, superoxide radical ion is formed, which reacts with 1,10-phenanthroline and gives a chemiluminescent emission. The 1,10-phenanthroline was destroyed during the chemiluminescent reaction, leaving a cavity and copper binding sites for another 1,10-phenanthroline molecule. The prepared polymer particles were packed into a glass tube and developed as a molecular recognition chemiluminescent flow-through sensor for 1,10-phenanthroline. The sensitivity and selectivity of the sensor were tested.

Color vision after laser in situ keratomileusis

PURPOSE

To evaluate the effect of laser in situ keratomileusis (LASIK) on color vision.

SETTING

Department of Ophthalmology, China Medical College Hospital, Taichung, Taiwan.

METHOD

This prospective study comprised consecutive patients having LASIK. Patients were eligible for inclusion if they had a best corrected visual acuity of 20/20 or better and a normal color vision test preoperatively and an uncorrected near visual acuity of 20/40 or better postoperatively. Color vision was tested using the Farnsworth-Munsell 100-hue test (FM 100 test) preoperatively and 1 day, 1 week, and 1 month postoperatively.

RESULTS

Twenty-nine eyes of 15 patients having LASIK were enrolled in the study. The mean patient age was 29.2 years +/- 2.9 (SD). The mean preoperative spherical equivalent refractive error was -5.6 +/- 1.8 diopters, and the mean preoperative error score of the FM 100 test was 3.79 +/- 1.55. After surgery, no significant change in the error score was observed at 1 day (4.30 +/- 1.07, P =.1039, paired t test), 1 week (3.72 +/- 1.25, P =.8125, paired t test), or 1 month (3.97 +/- 1.29, P =.6149, paired t test).

CONCLUSION

Laser in situ keratomileusis did not affect color vision evaluated by the FM 100 test.

Inspection of the reversal of enantiomer migration order in ligand exchange micellar electrokinetic capillary chromatography

Enantiometers of D,L-phenylalanine were separated by capillary electrophoresis based on the principle of ligand exchange. Copper (II) complex of 4-hydroxy-L-proline was used as chiral selector. The separation and the migration order of D- and L-phenylalanine were strongly affected by adding an anion surfactant sodium dodecylsulfate (SDS). Without SDS in the electrolyte, the separation was also carried out but the resolution was very small. With SDS added into the electrolyte, the resolution decreased with increasing concentration of SDS until 5.0 mM. When the concentration of SDS in the electrolyte was over 5.0 mM, inversion of the migration order of DL-phenylalanine was observed and the resolution was also increased with increasing concentration up to 20 mM. It was interesting to find that the inversion of the migration order took place not only in the enantioscparation but also in the positional isomers. A family of a fluorinated amino acid, o-, m- and p-fluoro-D,L-phenylalanine was separated and the inversion of the migration order is discussed.

Continuous preconcentration system for nitrate ions using anionic reverse osmosis tubes coupled to an ion chromatograph

A continuous preconcentration system for nitrate ions was developed using cation exchange tubing made from Nafion perfluorosulfonic acid membrane. This method is based on ion exclusion effects and reverse osmosis phenomena. The system was evaluated by connecting it to an ion chromatograph. The concentration ratios could be increased by raising the pressures between the two sides of the cation exchange tubing. Twenty-fold concentration of nitrate ion was achieved when the pump pressure was 20 x 10(5) Pa. The relative standard deviations of the preconcentration ratio at four different pump pressures, 5, 10, 15 and 20 x 10(5) Pa were 1.2-2.8% (n = 5).

Effect of laser-assisted in situ keratomileusis on the retinal nerve fiber layer

PURPOSE

To assess the effects of laser-assisted in situ keratomileusis (LASIK) on the retinal nerve fiber layer (RNFL).

METHOD

In a prospective study, the RNFL thickness of 35 eyes of 20 consecutive patients was measured before and 1 month after LASIK by scanning laser polarimetry.

RESULTS

The postoperative integrals and averages of RNFL thickness were statistically significantly lower than preoperative values, except in the temporal quadrant.

CONCLUSION

LASIK has a significant effect on RNFL thickness determined by scanning laser polarimetry. Further studies are needed to determine whether the corneal compensation algorithms are affected by the keratome flap, whether the decreased averages and integrals of the RNFL thickness are reversible, and how to protect the RNFL.

Studies on the synthesis of trans-dihydrodiols of polycyclic aromatic thiaarenes as potential proximate carcinogenic metabolites: first synthesis of trans-10,11-dihydroxy-10,11-dihydroacenaphtho[1, 2-b]benzo[d]thiophene and 6,7-dihydroxy-6,7-dihydronaphtho[1, 2-b]thiophene

Polyaromatic thiophene compounds are found to occur concomitantly with numerous coal-derived products and shale oils and are suspected mutagens and/or carcinogens. The first synthesis of the two title compounds 9 and 16 has been achieved in five or four steps starting from 8,9-dihydroacenaphtho[1,2-b]benzo[d]thiophene (1) and 7-methoxynaphtho[1,2-b]thiophene (12), respectively. Compound 1 was converted to the cis-diol (11) (via treatment with OsO(4)/pyridine) or to trans-diol (3) [via Prevost reaction (PhCOOAg/I(2)) followed by hydrolysis] in 95-98% yield, respectively. Subsequent dehydration (PTS/benzene) of the diol followed by aromatization of the resulting ketone (5) produced the phenolic compound 6 in 97% yield. Oxidation of the phenol with phenyl iododiacetate followed by hydrolysis of the o-quinone monoketal 7 gave the o-quinone (8) in 86% yield. Stereoselective reduction of 8 with NaBH(4)/EtOH under oxygen afforded trans-10,11-dihydroxy-10,11-dihydroacenaphtho[1,2-b]benzo[d]thi oph ene(9) (orange yellow solid) in 55% yield. Compound 16 was obtained as a colorless solid, through the stereoselective reduction of the o-quinone 15 (with NaBH(4)), which in turn was prepared from 12 following the protocol of functional group transformation of methoxy --> phenol --> o-quinone monoketal --> o-quinone, as used in the previous case. The yields for all the steps are very good. The mutagenicity assay of compound 9 and 16 as well as their parent thiaarenes have been performed. The results showed that 9 may not be the proximate carcinogen of acenaphtho[1,2-b]benzo[d]thiophene, while it is likely that compound 16 is one of the possible proximate carcinogens for naphtho[1,2-b]thiophene.

Anti-hypercholesterolaemia, antioxidant activity and free radical scavenger effects of traditional Chinese medicine prescriptions used for stroke

The generation of oxygen radicals and lipid peroxidation may be factors in the cerebral damage secondary to ischaemia of the cerebrovascular disease, as in stroke. Five traditional Chinese medicinal prescriptions were investigated for their antioxidant activity: Shiee Fuu Jwu Iu Tang (TCMP1), Oh Yaw Shuen Chin Saan (TCMP2), Buu Yang Hwan Wuu Tang (TCMP3), Sheau Shiuh Ming Tang (TCMP4), and Chir Hwu Jia Long Guu Muu Lih Tang (TCMP5). Anti-lipid peroxidation, anti-superoxide formation and free radical scavenger activity were determined by the FeCl2--ascorbic acid-induced lipid peroxidation effects on lipids in-vitro, xanthine oxidase inhibition, cytochrome C system and an electron spin resonance spectrometer, respectively. The results showed that TCMP5 had greater anti-lipid peroxidation and anti-superoxide formation activity than the other prescriptions. TCMP4 had the greatest free radical scavenging effect, TCMP5 showed the greatest superoxide radical scavenger activity and TCMP3 showed the greatest hydroxyl radical scavenger activity. Tests were also performed to evaluate the effects of the five prescriptions on blood lipid in-vivo. The test showed that the prescriptions decreased the level of total cholesterol and LDL-cholesterol in serum in high cholesterol-fed rats. From these results, it seems probable that these prescriptions may be effective in the prevention and therapy of stroke and ischaemia.

Synthesis of anti-1,2-dihydroxy-3,4-epoxy-1,2,3, 4-tetrahydro-6-nitrochrysene and its reaction with 2'-deoxyguanosine- 5'-monophosphate, 2'-deoxyadenosine-5'-monophosphate, and calf thymus DNA in vitro

The remarkable carcinogenic activity of 6-nitrochrysene (6-NC) in several animal models, and its environmental presence, suggest its potential importance with regard to human cancer development. Depending on the bioassay model, 6-NC can be activated by simple nitro reduction, ring oxidation, or by a combination of ring oxidation and nitro reduction. Only the first pathway has been clearly established. Thus, this study purports to unequivocally define the other pathways. Toward this end, we report for the first time the synthesis of anti-1,2-dihydroxy-3,4-epoxy-1,2,3, 4-tetrahydro-6-nitrochrysene (6-NCDE), a likely ultimate carcinogenic metabolite of 6-NC. Also, we describe our initial investigation of its binding with calf thymus DNA, 2'-deoxyguanosine-5'-monophosphate (2'-dGuo), and 2'-deoxyadenosine-5'-monophosphate (2'-dAdo) in vitro. These adduct markers were then employed for comparison with those obtained in the rat after in vivo treatment with 6-NC. On the basis of the results, it appears that the major adduct formed in the liver of rats treated with 6-NC is not derived from 6-NCDE.

Antioxidant and hepatoprotective effects of Anoectochilus formosanus and Gynostemma pentaphyllum

Anoectochilus formosanus Hay. and Gynostemma pentaphyllum Makino are popular folk medicines that have been used for treating hepatitis, hypertension and cancer in Taiwan. Our previous studies showed that these crude drugs exert antiinflammatory activity and hepatoprotective activity against CC14-induced liver damage. In this study, the antioxidant effect of these crude drugs and their hepatoprotective activity on acetaminophen-induced liver injury in rat was evaluated. Our results suggest that A. formosanus and G. pentaphyllum do have antioxidant effects. On acetaminophen-intoxicated model, the increased levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) by acetaminophen administration were reduced by treatment with these two herbs. In histological observation, gross necrosis in the centribular area, sinusoidal congestion, infiltration of the lymphocytes and Kupffer cells around the hepatic central vein, and loss of cell boundaries and ballooning degeneration were reduced with herbal treatment. However, the effect of A. formosanus and G. pentaphyllum is biphasic. Methanol extract (100 and 300 mg/kg) and water extract (300 and 500 mg/kg) of A formosanus and water extract (100, 300 and 500 mg/kg) of G. pentaphyllum enhanced the recovery of liver injury while treatment with 500 mg/kg of A. formosanus methanol extract resulted in serious hepatic injury.

Natural history of central islands after laser in situ keratomileusis

PURPOSE

To assess the incidence and natural history of central islands following laser in situ keratomileusis (LASIK) and evaluate the association of central island characteristics with visual acuity.

SETTING

Department of Ophthalmology, China Medical College Hospital, Taichung, Taiwan.

METHODS

A consecutive series of 406 eyes of 212 patients who had LASIK was retrospectively evaluated. Uncorrected visual acuity (UCVA) was measured and corneal topography performed preoperatively and 1 week and 1, 3, 6, and 9 months postoperatively. Best spectacle-corrected visual acuity (BSCVA) was evaluated preoperatively and 1, 3, and 6 months postoperatively.

RESULTS

The topographic images obtained at 1 week demonstrated central islands in 23 eyes of 20 patients (5.7%). No new cases of central island formation were identified after 1 week. Of the 23 eyes with central islands, the 6 month post-LASIK maps were available in 20 eyes of 18 patients. There was a significant difference in the size and power of the central islands between 1 week and 6 months. However, the power and size decreased slowly. Within 6 months, only 5 of 20 central islands (25.0%) had resolved. Eight eyes were undercorrected, and 1 eye lost 2 lines of BSCVA. Central islands larger than 1.8 mm or 3.0 diopters (D) were significantly correlated with lower UCVA.

CONCLUSION

Most central islands that occur with LASIK persist more than 6 months. Large central islands (>/=1.8 mm or >/=3.0 D) are risk factors for lower UCVA. Preventive measures are necessary.

[Identification of turtle shell, tortoise plastron and their counterfeit products]

OBJECTIVE

To identify the commercial Chinese medicines turtle shell and tortoise plastron.

METHOD

Morphological identification and differential thermal analysis (DTA).

RESULT

2 kinds of counterfeit turtle shell and 3 kinds of counterfeit tortoise plastron were found, and their morphological and DTA identification features were proposed.

CONCLUSION

Sea turtle shells presently on the market are sham commodities of turtle shell, which derive from Lissemys punctata and Pelochelys bibroni indigenous to south Asia, while plastrons of Ocadia sinensis, Chelonia mydas and Lepidochelys olivacea are counterfeit products of tortoise plastron. Turtle shells, tortoise plastrons and their counterfeit products may be exactly distinguished by morphological and DTA features.

Ablation centration after active eye-tracker-assisted photorefractive keratectomy and laser in situ keratomileusis

PURPOSE

To evaluate the ablation centration after active eye-tracker-assisted photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) and to investigate the effect of surgery, patient, and surgeon on the centration.

SETTING

Department of Ophthalmology, China Medical College Hospital, Taichung, Taiwan, Republic of China.

METHODS

This retrospective study comprised 177 eyes of 101 patients: 16 eyes had PRK and 161, LASIK. All laser treatments were performed with the aid of an eye tracker. The amount of decentration was analyzed by corneal topography. The factors influencing centration were divided into surgery related (PRK/LASIK), patient related (low/high myopia and effect of learning), and surgeon related (learning curve).

RESULTS

The mean decentration was 0.33 mm in PRK eyes and 0.35 mm in LASIK eyes. For the surgery-related factor, there was no significant difference between the PRK and LASIK eyes. For the patient-related factors, centration was better in the second eye (effect of learning) and decentration was more severe in eyes with high myopia (low/high myopia). For the surgeon-related factor, there was no significant difference between eyes that had the first 50 LASIK procedures and those that had the last 50 procedures.

CONCLUSIONS

An eye tracker, which makes the laser beam follow the eye's movements, helps to avoid severe decentration. This study showed, however, that an active eye-tracking system alone cannot ensure good centration. Patient cooperation and fixation are important.

Interleukin-6 activates phosphatidylinositol-3 kinase, which inhibits apoptosis in human prostate cancer cell lines

BACKGROUND

A number of recent studies have identified interleukin (IL)-6 as an important regulator of prostate cancer growth. Here, we investigate the potential interaction of IL-6 with phosphatidylinositol (PI)-3 kinase, a key growth regulatory enzyme, in prostate cancer cell lines.

METHODS

Tyrosine phosphorylation of p85, the regulatory subunit of PI-3 kinase, in the human prostate cancer cell lines LNCaP and PC-3 was assessed by sequential immunoprecipitation with anti-p85 antibody and immunoblotting with anti-phosphotyrosine. The effects of wortmannin, an inhibitor of PI-3 kinase, and/or IL-6 on cell growth were assessed by MTT assays. DNA laddering experiments were performed to assay for programmed cell death.

RESULTS

Tyrosine phosphorylation of p85 is upregulated by IL-6 in both LNCaP and PC-3. IL-6 promotes coprecipitation of p85 with gp130, the signal-transducing component of the IL-6 receptor. Inhibition of PI-3 kinase with wortmannin induces programmed cell death in PC-3 cells. In contrast, wortmannin has no effect on LNCaP growth when used alone; however, combined with IL-6, wortmannin promotes apoptosis in these cells.

CONCLUSIONS

PI-3 kinase is involved in IL-6 signal transduction and delivers an antiapoptotic signal in human prostate cancer cell lines.

V(D)J recombination catalyzed by mutant RAG proteins lacking consensus DNA-PK phosphorylation sites

The process of antigen receptor gene rearrangement, V(D)J recombination, involves DNA cleavage by the RAG-1 and RAG-2 proteins. Cleavage generates covalently sealed (hairpin) DNA ends, termed coding ends, which must be opened by an endonuclease prior to joining. Resolution of these hairpin ends requires the activity of the DNA-dependent protein kinase (DNA-PK), a protein kinase whose specific role is yet undetermined. It has been suggested that phosphorylation of one or both RAG proteins by DNA-PK is required to activate or recruit the hairpin-opening nuclease. Furthermore, very recent work has shown that RAG proteins themselves can open hairpins. These data raise the possibility that DNA-PK-mediated phosphorylation of the RAG proteins could regulate the hairpin opening reaction. To test this hypothesis, we constructed mutant versions of RAG-1 and RAG-2 in which all four DNA-PK consensus phosphorylation sites were removed by site-directed mutagenesis. Our data provide conclusive evidence that phosphorylation of these conserved serine/threonine residues is not required for hairpin opening or joining of V(D)J recombination intermediates.

Correlation of the flow patterns among the four pulmonary veins as assessed by transesophageal echocardiography: influence of significant mitral regurgitation

AIMS

To evaluate the correlation of the flow patterns of the four pulmonary veins as assessed by transesophageal echocardiography and the influence of significant mitral regurgitation on this correlation.

METHODS AND RESULTS

Eighty-eight patients with normal sinus rhythm and variable underlying cardiovascular diseases underwent transthoracic and transesophageal echocardiographic studies. Doppler flow of the four pulmonary veins could not be adequately interpreted in 19 patients (22%). The left atrial dimension of these patients was significantly larger than that of the patients with complete study of the flow in the four pulmonary veins (49 +/- 6 vs. 43 +/- 7 mm; p < 0.05). Of the 69 patients with complete evaluation of the four pulmonary veins, 48 patients without significant mitral regurgitation were analyzed as group A, and the remaining 21 patients as group B. The peak systolic and diastolic forward flow velocities of the four pulmonary veins were measured and the ratio of peak systolic (S) to diastolic (D) flow velocity was calculated. Group A had a significantly larger S/D ratio in all four pulmonary veins than group B (p < 0.05 in each pulmonary vein measurement). There was good correlation of the flow pattern represented as S/D ratio between left upper and lower pulmonary veins (r = 0.90) and between right upper and lower pulmonary veins (r = 0.89) in group A. The correlation of the flow pattern among the four pulmonary veins deteriorated in group B.

CONCLUSION

Pulmonary veins on the same side share rather similar flow patterns in comparison with pulmonary veins on the opposite sides. The correlation of flow patterns among the four pulmonary veins is good in subjects without significant mitral regurgitation, but it worsens in patients with significant mitral regurgitation. Therefore, cautious interpretation of flow patterns of the four pulmonary veins in patients with significant regurgitation is indicated for grading the severity of mitral regurgitation.

Preserved pulsatile insulin release from prediabetic mouse islets

During the development of type I diabetes, the plasma insulin pattern changes. Because the islet secretory pattern has been implicated in this phenomenon, insulin release was measured from female nonobese diabetic (NOD) mouse islets isolated at different ages. Islets from 5-week-old mice were used as controls because they had no infiltrating mononuclear cells and insulin release rose almost 9-fold with maintained oscillatory frequency when the glucose concentration was raised from 3 to 11 mM. Islets isolated from 13- and 25-week-old mice were infiltrated with mononuclear cells. In these islets, increase in the glucose concentration from 3 to 11 mM only doubled insulin release. However, despite the cellular infiltration, insulin release was pulsatile. Islets from 13-week-old mice had reduced glucose oxidation rate. Culture of such islets for 7 days at 11.1 mM glucose causes a decrease in the number of mononuclear cells infiltrating the islets, which in the present study was accompanied by a normalization of both glucose oxidation and glucose-induced insulin release. In the presence of the mitochondrial substrate alpha-keto-isocaproate (5 mM) both control and infiltrated islets responded with pronounced insulin pulses with similar amplitudes. The results suggest that the deranged plasma insulin pattern observed during the development of type I diabetes may be related to decrease in the insulin pulse amplitude rather than loss of the pulsatile release from the islets.

Eukaryotic expression cloning with an antimetastatic monoclonal antibody identifies a tetraspanin (PETA-3/CD151) as an effector of human tumor cell migration and metastasis

A monoclonal antibody (mAb), 50-6, generated by subtractive immunization, was found to specifically inhibit in vivo metastasis of a human epidermoid carcinoma cell line, HEp-3. The cDNA of the cognate antigen of mAb 50-6 was isolated by a modified eukaryotic expression cloning protocol from a HEp-3 library. Sequence analysis identified the antigen as PETA-3/CD151, a recently described member of the tetraspanin family of proteins. The cloned antigen was also recognized by a previously described antimetastatic antibody, mAb 1A5. Inhibition of HEp-3 metastasis by the mAbs could not be attributed to any effect of the antibodies on tumor cell growth in vitro or in vivo. Rather, the antibodies appeared to inhibit an early step in the formation of metastatic foci. In a chemotaxis assay, HEp-3 migration was blocked by both antibodies. HeLa cells transfected with and overexpressing PETA-3/CD151 were more migratory than control transfectants expressing little CD151. The increase in HeLa migration was inhibitable by both mAb 50-6 and mAb 1A5. PETA-3 appears not to be involved in cell attachment because adhesion did not correlate with levels of PETA-3 expression and was unaffected by mAb 50-6 or mAb 1A5. The ability of PETA-3 to mediate cell migration suggests a mechanism by which this protein may influence metastasis. These data identify PETA-3/CD151 as the first member of the tetraspanin family to be linked as a positive effector of metastasis.

Synthesis of anti-7,8-dihydroxy-9,10-epoxy-7,8,9, 10-tetrahydro-11-methylbenzo[a]pyrene and its reaction with DNA

Substitution of a methyl group in the bay region can enhance the tumorigenicity of polycyclic aromatic hydrocarbons such as chrysene, benz[a]anthracene, and others. This phenomenon has been related to facile DNA adduct formation of bay region diol epoxides with a methyl group and epoxide ring in the same bay. While anti-7, 8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene and its DNA adduct formation have been studied extensively, it is not known whether a methyl substituent in the bay region alters the reactivity of DNA in this system. This is of interest because 11-methylbenzo[a]pyrene, which has a bay region methyl group, is more tumorigenic than benzo[a]pyrene. To examine the question, we have devised and employed an efficient synthesis based on photochemical cyclization, and prepared anti-7,8-dihydroxy-9, 10-epoxy-7,8,9,10-tetrahydro-11-methylbenzo[a]pyrene, the likely ultimate carcinogen of 11-methylbenzo[a]pyrene. We have then reacted anti-7,8-dihydroxy-9,10-epoxy-7,8,9, 10-tetrahydro-11-methylbenzo[a]pyrene with calf thymus DNA and found that it gives three major adducts. These were identified as having resulted from cis- and trans-ring opening of the (S,R,R, S)-enantiomer and from trans-ring opening of the (R,S,S, R)-enantiomer. The standard deoxyguanosine adduct markers were prepared, and their structures were tentatively assigned on the basis of their CD and 1H NMR spectra. The adduct distribution of anti-7,8-dihydroxy-9,10-epoxy-7,8,9, 10-tetrahydro-11-methylbenzo[a]pyrene is quite different from that observed in the reaction of DNA with the corresponding diol epoxides of benzo[a]pyrene or with 5-methylchrysene. The heterogeneity of adducts obtained with anti-7,8-dihydroxy-9,10-epoxy-7,8,9, 10-tetrahydro-11-methylbenzo[a]pyrene thus may be related to the enhanced tumorigenicity of 11-methylbenzo[a]pyrene.

Cloning and expression of a wheat (Triticum aestivum L.) phosphatidylserine synthase cDNA. Overexpression in plants alters the composition of phospholipids

We describe the cloning of a wheat cDNA (TaPSS1) that encodes a phosphatidylserine synthase (PSS) and provides the first strong evidence for the existence of this enzyme in a higher eukaryotic cell. The cDNA was isolated on its ability to confer increased resistance to aluminum toxicity when expressed in yeast. The sequence of the predicted protein encoded by TaPSS1 shows homology to PSS from both yeast and bacteria but is distinct from the animal PSS enzymes that catalyze base-exchange reactions. In wheat, Southern blot analysis identified the presence of a small family of genes that cross-hybridized to TaPSS1, and Northern blots showed that aluminum induced TaPSS1 expression in root apices. Expression of TaPSS1 complemented the yeast cho1 mutant that lacks PSS activity and altered the phospholipid composition of wild type yeast, with the most marked effect being increased abundance of phosphatidylserine (PS). Arabidopsis thaliana leaves overexpressing TaPSS1 showed a marked enhancement in PSS activity, which was associated with increased biosynthesis of PS at the expense of both phosphatidylinositol and phosphatidylglycerol. Unlike mammalian cells where PS accumulation is tightly regulated even when the capacity for PS biosynthesis is increased, plant cells accumulated large amounts of PS when TaPSS1 was overexpressed. High levels of TaPSS1 expression in Arabidopsis and tobacco (Nicotiana tabacum) led to the appearance of necrotic lesions on leaves, which may have resulted from the excessive accumulation of PS. The cloning of TaPSS1 now provides evidence that the yeast pathway for PS synthesis exists in some plant tissues and provides a tool for understanding the pathways of phospholipid biosynthesis and their regulation in plants.

Nitroreduction of 4-nitropyrene is primarily responsible for DNA adduct formation in the mammary gland of female CD rats

We determined whether DNA adducts derived from 4-nitropyrene (4-NP) are formed via nitroreduction or ring oxidation. DNA adduct markers derived from both pathways were prepared and, consequently, were compared with those obtained in vivo in rats treated with 4-NP. Following in vitro reaction of 9,10-epoxy-9,10-dihydro-4-nitropyrene (4-NP-9,10-epoxide), an intermediate metabolite derived from ring oxidation of 4-NP, with calf thymus DNA (average level of binding in two determinations was 8.5 nmol/mg of DNA), DNA was enzymatically hydrolyzed to deoxyribonucleosides and the DNA hydrolysates were analyzed by HPLC. Electrospray mass and 1H NMR spectra of the major products indicated that these adducts are deoxyguanosine (dG) derivatives that resulted from N2-dG substitution at the 9- or 10-position of the pyrene nucleus. However, these adducts were not detected in vivo in the rat mammary gland and liver following the administration of 4-NP. Nitroreduction of 4-NP catalyzed by xanthine oxidase in the presence of DNA resulted in three major putative DNA adducts (level of binding of 12.0 +/- 1.1 nmol/mg of DNA, n = 4) designated as peak 1 (46%), peak 2 (25%), and peak 3 (17%). Although peak 1 was further resolved into peaks 1a and 1b, both were unstable and gradually decomposed to peak 2, and the latter was unequivocally identified as pyrene-4,5-dione. On the basis of electrospray mass spectral analysis, peak 3 was tentatively identified as a deoxyinosine-derived 4-aminopyrene adduct. None of the adducts derived from nitroreduction of 4-NP catalyzed by xanthine oxidase coeluted with the synthetic standard N-(deoxyguanosin-8-yl)-4-aminopyrene prepared by reacting dG with N-acetoxy-4-aminopyrene. Nevertheless, HPLC analysis of the hydrolysates of liver and mammary DNA obtained from rats treated with [3H]-4-NP yielded four radioactive peaks, all of which coeluted with the markers derived from the nitroreduction pathway. These results indicate that nitroreduction is primarily responsible for DNA adduct formation in the liver and, especially, in the mammary gland which is the organ susceptible to carcinogenesis by this environmental agent.