Synthesis of CaCO3 supported nano zero-valent iron-nickel nanocomposite (nZVI-Ni@CaCO3) and its application for trichloroethylene removal in persulfate activated system

Nano zero-valent (nZVI) based composite have been widely utilized in environmental remediation. However, the rapid agglomeration and quick deactivation of nZVI limited its application on large scale. In this work, CaCO3 supported nZVI-Ni catalyst, namely nZVI-Ni@CaCO3 was prepared and used for the efficient removal of trichloroethylene (TCE) in PS oxidation process. The successful disbursement of nZVI-Ni on CaCO3 support material not only increased the surface area of nZVI-Ni@CaCO3 (69.45 m2/g) with respect to CaCO3 (5.92 m2/g) and bare nZVI (13.29 m2/g) but also improved the catalytic activity. XRD, XPS and FTIR analysis confirmed the successful formation of nZVI-Ni@CaCO3 nanoparticles. The nZVI-Ni@CaCO3 nanoparticles combined with PS had achieved complete removal of TCE (99.8%) with dosage of 36 mg/L and 1.34 mM respectively. These results showed that the use of CaCO3 as support material for nZVI-Ni could have significant influence on contaminant removal process. Scavenging and EPR tests validated the existence of SO4•-, OH• and O2•- radicals in PS/nZVI-Ni@CaCO3 system and highlighted the dominant role of SO4•- radicals in TCE removal process. HCO3- ions and humic acid have shown adverse effect on TCE removal due to radical scavenging and buffering effect. Owing to improved catalytic activity and easy preparation, the nZVI-Ni@CaCO3 nanoparticles could be served as an alternative strategy for environmental remediation.

Microplastic pollutants in water: A comprehensive review on their remediation by adsorption using various adsorbents

Microplastics (MPs), as emerging pollutants, have attracted the attention of environmentalists, statespersons, and the scientific community over the last few decades. To address the spread of MPs in the environment, it is imperative to develop various removal techniques and materials that are effective, scalable, and ecologically benign. However, to the best of our knowledge, no review has systematically examined the removal of MPs using adsorption or provided an in-depth discussion on various adsorbents. Adsorption is an inexpensive and effective technology for wastewater treatment. Recently, many researchers have conducted studies on MP remediation using diverse adsorbent materials, such as biochar, activated carbon, sponges, carbon nanotubes, metal-layered oxides, metal-organic frameworks (MOFs), and zeolites. Each adsorbent has advantages and disadvantages. To overcome their disadvantages, researchers have been designing and developing hybrid adsorbents for MP remediation. This review provides insights into these individual adsorbents and also discusses hybrid adsorbents for MP removal. Finally, the review elaborates on future possibilities and ways to enable more efficient, scalable, and environmentally friendly MP cleanup. Overall, this review bridges the gap between contemporary MP remediation using adsorption techniques and adsorbent development.

Effects of oleanolic acid on acute liver injury triggered by lipopolysaccharide in broiler chickens

1. Infectious injury caused by lipopolysaccharide (LPS), a metabolite of gram-negative bacteria, can induce stress responses in animals and is a significant cause of morbidity and mortality in young birds. The purpose of this study was to investigate the effects of dietary supplementation with oleanolic acid (OA) on acute liver injury in broiler chickens challenged with LPS.2. In total, 120 broiler chickens were randomly divided into six groups and fed a basal diet containing 0, 50, 100, or 200 mg/kg OA or 100 mg/kg aureomycin. On d 15, broiler chickens were injected with either LPS or an equivalent volume of normal saline. Six hours after LPS injection, two broiler chicks were randomly selected for sampling in each replicate.3. The results indicated that dietary aureomycin was ineffective in alleviating LSP-associated liver injury, but protected broiler chickens from LPS-induced liver damage. This promoted a significant reduction in the levels of malondialdehyde and an increase in the levels of superoxide dismutase in liver. In addition, OA was found to cause significant reductions in the relative expression of IL-1β, IL-6, and TNF-α in broiler liver tissues, whereas the relative expression of IL-10 was significantly increased.4. In conclusion, oleanolic acid can alleviate oxidative stress and injury in the livers of broiler chickens induced by lipopolysaccharide. Consequently, oleanolic acid has potential utility as a novel anti-inflammatory and antioxidant feed additive.

Degradation of trichloroethylene in aqueous solution by FeS2 catalyst under innovative oxic environments

Rapid growth and industrialization have become a major threat to water contamination with carcinogenic chlorinated hydrocarbons such as trichloroethylene (TCE). Therefore, this study aims to assess the TCE degradation performance through advanced oxidation process (AOP) using catalyst FeS2 in combination with oxidants persulfate (PS), peroxymonosulfate (PMS), and hydrogen peroxide (H2O2) in PS/FeS2, PMS/FeS2, and H2O2/FeS2 systems, respectively. TCE concentration was analyzed using gas chromatography (GC). The results found the trend for TCE degradation by the systems was PMS/FeS2>PS/FeS2>H2O2/FeS2 (99.84, 99.63, and 98.47%, respectively). Degradation of TCE was analyzed at different pH ranges (3-11) and maximum degradation at a wide pH range was observed for PMS/FeS2. The analysis using electron paramagnetic resonance (EPR) and scavenging tests explored responsible reactive oxygen species (ROS) for TCE degradation and found that HO• and SO4-• played the most effective role. The results of catalyst stability showed PMS/FeS2 system the most promising with the stability of 99, 96 and 50% for the first, second and third runs, respectively. The system was also found efficient in the presence of surfactants (TW-80, TX-100, and Brij-35) in ultra-pure water (89.41, 34.11, 96.61%, respectively), and actual groundwater (94.37, 33.72, and 73.48%, respectively), but at higher reagents dosages (5X for ultra-pure water and 10X actual ground water). Furthermore, it is demonstrated that the oxic systems have degradation capability for other TCE-like pollutants. In conclusion, due to its high stability, reactivity, and cost-effectiveness, PMS/FeS2 system could be a better choice for the treatment of TCE contaminated water and can be beneficial for field application.

Mechanism of trichloroethylene degradation in Fe(II)-activated peroxymonosulfate coupled with citric acid system in the presence of surfactants

This study demonstrated that peroxymonosulfate (PMS) activated by Fe(II)/citric acid (CA) could effectively degrade trichloroethylene (TCE) in the presence of Tween-80 (TW-80) or sodium dodecyl sulfate (SDS). Significant TCE removal of 91.6% (90.1%) with 1.3 g L^-1 TW-80 (2.3 g L^-1 SDS) were achieved at the PMS/Fe(II)/CA/TCE molar ratio of 4/4/4/1 (20/20/20/1). TCE degradation could be greatly elevated by Fe(II) and CA addition, while the existence of surfactants restrained TCE removal and the inhibitory effect increased with the higher surfactant concentration. The tests of the electron paramagnetic resonance (EPR) and reactive radicals scavenging experiments proved that sulfate radical (SO₄^-•), hydroxyl radical (HO•), and superoxide radical (O₂^-•) were responsible for TCE degradation and SO₄^-• acted as the major one. The influences of initial solution pH and inorganic anions k(Cl^- and HCO₃^-) on TCE removal were also investigated. Eventually, TCE removal in actual groundwater tests with surfactants confirmed that the PMS/Fe(II)/CA process has a huge potential of practical application in remediating the groundwater contaminated by TCE after the pretreatment by solubilization using surfactants.

Enhancement in reactivity via sulfidation of FeNi@BC for efficient removal of trichloroethylene: Insight mechanism and the role of reactive oxygen species

A novel catalyst of sulfidated iron-nickel supported on biochar (S-FeNi@BC) was synthesized to activate persulfate (PS) for the removal of trichloroethylene (TCE). A number of techniques including XRD, SEM, TEM, FTIR, BET and EDS were employed to characterize S-FeNi@BC. The influence of sulfur to iron ratio (S/F) on TCE removal was investigated by batch experiments and a higher TCE removal (98.4%) was achieved at 0.22/1 ratio of S/F in the PS/S-FeNi@BC oxidation system. A dominant role in iron species conversion was noticed by the addition of sulfur in FeNi@BC system. Significant enhancement in recycling of the dissolved and surface Fe(II) was confirmed which contributed to the generation of free and surface-bound active radical species (OH, O₂^-, ¹O₂, SO₄^-). Further, the presence and contribution of these radicals were validated by the electron paramagnetic resonance (EPR) and quenching study. In addition, XPS results demonstrated the dominant role of S(-II) with the increase of Fe(II) from 36.3% to 58.6% and decrease of Fe(III) from 52.1% to 39.8% in the PS/S-FeNi@BC system. In crux, the influence of initial pH, catalyst dosage, oxidant dosage, and inorganic ions (HCO₃^-, Cl^-, NO₃^- and SO₄^2-) on TCE removal was also investigated. The findings obtained from this study suggest that S-FeNi@BC is an appropriate catalyst to activate PS for TCE contaminated groundwater remediation.

Unveiling the catalytic ability of carbonaceous materials in Fenton-like reaction by controlled-release CaO2 nanoparticles for trichloroethylene degradation

Carbonaceous materials (CMs) have been applied extensively for enhancing the catalytic performance of environmental catalysts, however, the self-catalytic mechanism of CMs for groundwater remediation is rarely investigated. Herein, we unveiled the catalytic ability of various CMs via Fe(III) reduction through polyvinyl alcohol-coated calcium peroxide nanoparticles (PVA@nCP) for trichloroethylene (TCE) removal. Among selected CMs (graphite (G), biochar (BC) and activated carbon (AC)), BC and AC showed enhancement of TCE removal of 89% and 98% via both adsorption and catalytic degradation. BET and SEM analyses showed a higher adsorption capacity of AC (27.8%) than others. The generation of solution-Fe(II) and surface-Fe(II) revealed the reduction of Fe(III) on CMs-surface. The role of O-containing groups was investigated by the FTIR technique and XPS quantified the 52% and 57% surface-Fe(II) in BC and AC systems, respectively. EPR and quenching tests confirmed that both solution and surface-bound species (HO•, O₂^-• and ¹O₂) contributed to TCE degradation. Acidic pH condition encouraged TCE removal and the presence of HCO₃^- negatively affected TCE removal than other inorganic ions. Both schemes (PVA@nCP/Fe(III)/BC and PVA@nCP/Fe(III)/AC) exhibited promising results in the actual groundwater, surfactant-amended solution, and removal of other chlorinated-pollutants, opening a new direction towards green environmental remediation for prolonged benefits.

Mechanism of surfactant in trichloroethene degradation in aqueous solution by sodium persulfate activated with chelated-Fe(II)

The mechanism of surfactants in surfactant-in situ chemical oxidation (S-ISCO) coupled process for trichloroethene (TCE) degradation was firstly reported. The performance of TCE solubilization and inhibition of TCE degradation in three nonionic surfactants (TW-80, Brij-35, TX-100) in PS/Fe(II)/citric acid (CA) system was compared and TW-80 was evaluated to be the optimal surfactant in S-ISCO coupled process due to the best TCE solubilizing ability and minimal inhibition for TCE degradation (only 31.8% TCE inhibition in the presence of 1 g L^-1 TW-80 surfactant). The inhibition mechanism in TCE degradation was also demonstrated by comparing the strength of ROSs and PS utilization. In the presence of TW-80 (1 g L^-1), over 97.5% TCE was removed at the PS/Fe(II)/CA/TCE molar ratio of 30/4/4/1, in which more than 86.7% TCE was dechlorinated. The result of scavenger experiments revealed that the dominant radicals were HO• and SO₄^-• in PS/Fe(II)/CA system in TW-80 containing aqueous solution, among which SO₄^-• performed a greater role in TCE removal. Moreover, over 85.3% TCE degradation in actual groundwater revealed the potential of PS/Fe(II)/CA process for actual groundwater remediation in containing TW-80 of TCE contaminant. This research provided a novel alternative technology for groundwater remediation with TCE contaminant when containing surfactants.

Case report: Pulmonary artery thrombosis in cyanotic congenital heart disease

Cyanotic congenital cardiac anomalies increase the risk of thrombosis. In pediatric congenital heart disease, the diagnosis of pulmonary artery thrombosis is rare. We reported an 11-year-old male child who developed progressive shortness of breath over six months. He was subsequently referred to the National Institute of Cardiovascular Diseases, Karachi, Pakistan. The child was diagnosed as a case of double outlet left ventricle, levo-transposition of the great arteries, pulmonary stenosis, ventricular septal defect and thrombus in the main pulmonary artery with extension into the branch pulmonary arteries. He underwent thromboendarterectomy with a Glenn shunt and made an uneventful postoperative recovery.

Trichloroethylene degradation by PVA-coated calcium peroxide nanoparticles in Fe(II)-based catalytic systems: enhanced performance by citric acid and nanoscale iron sulfide

In this study, the enhanced trichloroethylene (TCE) degradation performance was investigated by polyvinyl alcohol coated calcium peroxide nanoparticles (PVA@nCP) as an oxidant in Fe(II)-based catalytic systems. The nanoscale iron sulfide (nFeS), having an average particle size of 115.4 nm, was synthesized in the laboratory and characterized by SEM, TEM, HR-TEM along with EDS elemental mapping, XRD, FTIR, ICP-OES, and XPS techniques. In only ferrous iron catalyzed system (PVA@nCP/Fe(II)), TCE degradation was recorded at 58.9% in 6 h. In comparison, this value was increased to 97.5% or 99.7% with the addition of citric acid (CA) or nFeS in PVA@nCP/Fe(II) system, respectively. A comparative study was performed with optimum usages of chemical reagents in both PVA@nCP/Fe(II)/CA and PVA@nCP/Fe(II)/nFeS systems. Further, the probe compounds tests and electron paramagnetic resonance (EPR) analysis confirmed the generation of reactive oxygen species. The scavenging experiments elucidated the dominant role of HO• to TCE degradation, particularly in PVA@nCP/Fe(II)/nFeS system. Both CA and nFeS strengthened PVA@nCP/Fe(II) system, but displayed completely different mechanisms in the enhancement of active radicals generation; hence, their different contribution to TCE degradation. The acidic environment was favorable for TCE degradation, and a high concentration of HCO₃^- inhibited TCE removal in both systems. Conclusively, compared to PVA@nCP/Fe(II)/nFeS system, PVA@nCP/Fe(II)/CA system resulted in encouraging TCE degradation outcomes in actual groundwater, showing great potential for prolonged benefits in the remediation of TCE polluted groundwater. Graphical abstract.

Development and Validation of an Analytical Method to Quantitate Tris(chloroisopropyl)phosphate in Rat and Mouse Plasma using Gas Chromatography with Flame Photometric Detection

Tris(chloropropyl)phosphate (TCPP) is an organophosphorus flame retardant (OPFR) and plasticizer increasingly used in consumer products and as a replacement for brominated flame retardants. Commercially available TCPP is a mixture of four structural isomers the most abundant of which is tris(1-chloro-2-propyl)phosphate (TCPP-1). Although there is a widespread use of TCPP and potential for human exposure, there is limited data on the safety or toxicity of TCPP. The National Toxicology Program is conducting long-term studies to examine the toxicity of the TCPP in rats after lifetime exposure, including perinatal oral exposure. Quantitative estimates of internal dose are essential to interpret toxicological findings in rodents. To aid in this, a method was fully validated to quantitate the most abundant isomer, TCPP-1, in female Harlan Sprague Dawley (HSD) rat and B6C3F1 mouse plasma with partial validation in male rat plasma, and male and female mouse plasma. The method used protein precipitation using trichloroacetic acid followed by the extraction with toluene, and analysis by gas chromatography with flame photometric detection. The performance of the method was evaluated over 5-70 ng TCPP-1/mL plasma. The method was linear (r ≥ 0.99), accurate (inter-day relative error: ≤ ± -7.2) and precise (inter-batch relative standard deviation: ≤27.5%). The validated method has lower limits of quantitation and detection of ~5 and 0.9 ng/mL, respectively, in female HSD rat plasma and can be used on samples as small as 50 μL demonstrating the applicability to plasma samples from toxicology studies.

Effects of dietary supplementation of fulvic acid on lipid metabolism of finishing pigs

The experiment was conducted to investigate the effects of dietary supplementation of fulvic acid on lipid metabolism of finishing pigs. One hundred eighty crossbred barrows (Landrace × Yorkshire, 60 ± 2.5 kg) were randomly allotted to 5 dietary treatments (36 pigs/treatment) and fed a basal diet supplemented with 0, 0.2%, 0.4%, 0.6%, and 0.8% fulvic acid for 42 d. Thirty pigs (6 pigs/treatment) were slaughtered at the end of the experiment. Blood samples and adipose tissue were collected for determination of blood parameters and lipid metabolic enzymes. The results showed that compared with the control group, dietary supplementation of 0.2%, 0.4%, and 0.6% fulvic acid significantly reduced mean backfat thickness of pigs (P < 0.05). The serum concentrations of low-density lipoprotein, leptin, growth hormone, insulin, and triiodothyronine were significantly increased by adding fulvic acid in diets (P < 0.05). With the raised concentration of dietary fulvic acid, hormone sensitive lipase (HSL) activity was significantly increased (P < 0.05), and lipoprotein lipase (LPL) activity was significantly decreased (P < 0.05) in adipose tissue. In conclusion, dietary supplementation of fulvic acid reduced the mean backfat thickness of pigs. This change related to the increased activity of HSL and the decreased activity of LPL in adipose tissue.

Preventing the preventable: role of transamine in total knee arthroplasty

OBJECTIVE

To assess the efficacy and safety of perioperative intravenous Tranexamic Acid in reducing blood loss and transfusion requirements in patients undergoing Total Knee Arthroplasty.

METHODS

The prospectivedouble-blind randomised control trial was conducted from March to July 2014 at the Combined Military Hospital, Rawalpindi, and comprised patients below 85 years of age undergoing unilateral or bilateral cemented Total Knee Arthroplasty. The patients were divided into control or Transaminegroups. Two doses of 15mg/kg of Transamine were given to the latter group. All patients were operated under spinal or combined spinal-epidural anaesthesiausing pneumatic tourniquet and similar cemented implant. Primary outcome was postoperative blood loss in drains. Secondary outcomes were the number of blood units transfused, change in haemoglobin level and adverse events.

RESULTS

Of the 62 patients on the study, there were 34(55%) patents in the Transaminegroup with a mean age of 64±8.4 years, and28(45%)in the control group with a mean age of 60.8±10.3. The two groups were matched for demographic and blood indices.Mean blood loss via intra-articular drain in the control group was 619±243ml per knee, and 402±169ml per knee in the Transaminegroup. Blood transfusions were required by 14(50%)patients in the control groupand 6(17.6%)in the Transaminegroup.

CONCLUSIONS

Perioperative intravenous transamine significantly reduced blood loss as well as blood transfusion requirements.

Biochemical changes and oxidative stress induced by zearalenone in the liver of pregnant rats

The aim of the present research was to examine the toxic influence of different doses of zearalenone (ZEN) on the liver, especially oxidative stress induced by ZEN on the liver. A total of 48 pregnant Sprague-Dawley rats were randomly assigned into 4 treatments groups with 12 animals in each. The rats were fed with a normal diet treated with 0 mg/kg (control), 50 mg/kg (treatment 1), 100 mg/kg (treatment 2), or 150 mg/kg (treatment 3) ZEN in feed on gestation days (GDs) 0–7 and then all the rats were fed with a normal diet on GDs 8–20. The experimental period lasted 21 days. The results showed that exposure to ZEN induced increase in aspartate amino transferase, alanine aminotransferase, and alkaline phosphatase activities and decrease in total protein and albumin content in a dose-dependent manner and also induce decrease in superoxide dismutase and glutathione peroxidase activities and increase in malondialdehyde content in a dose-dependent manner in the serum and the liver. The increased transcription of cytochrome P450 2E1 (CYP2E1) was detected in the liver after exposure to ZEN. These results suggested that ZEN not only caused damage in the liver of pregnant rats in a dose-dependent manner but also induced the messenger RNA expression of CYP2E1 in the liver.

Antioxidant enzyme expression and reactive oxygen species damage in prostatic intraepithelial neoplasia and cancer

BACKGROUND

Oxidative stress results in damage to cellular structures and has been linked to many diseases, including cancer. The authors sought to determine whether the expression of three major antioxidant enzymes, copper-zinc superoxide dismutase (SOD1), manganese superoxide dismutase (SOD2), and catalase, was altered in human prostate carcinoma and its likely precursor, high grade prostatic intraepithelial neoplasia (PIN). The level of reactive oxygen species damage was evaluated by measuring the expression of the DNA adduct 8-hydroxydeoxyguanosine.

METHODS

The authors evaluated the tissue expression of the antioxidant enzymes in prostate carcinoma by immunohistochemistry, immunogold electron microscopy, and enzymatic assay. The polymerase chain reaction was used to amplify and screen tissue specimens for the genes of SOD1, SOD2, and extracellular SOD (SOD3). Matched paraffin embedded tissue sections were evaluated by RNA in situ hybridization for expression of SOD1 and immunohistochemically for the DNA adduct 8-hydroxydeoxyguanosine.

RESULTS

All prostatic tissues, including cancer, displayed immunoreactivity for the three antioxidant enzymes in epithelial cells, with no staining of the stroma, inflammatory cells, or endothelial cells. The number of immunoreactive cells was greater in benign epithelium than in PIN and cancer for each enzyme. The mean percentage and intensity of immunoreactive cells was greatest for SOD2, intermediate for SOD1, and lower for catalase. Staining in cancer was heterogeneous. Immunogold ultrasound studies revealed strong mitochondrial labeling for SOD2, which was greater in benign epithelium than in cancer; SOD1 labeling was invariably weaker, with nuclear labeling in benign epithelium and cytoplasmic labeling in cancer cells. There was no difference in enzyme activity for the three antioxidant enzymes between benign epithelium and cancer. No mutations were found in the 5 exons of SOD1, 5 exons of SOD2, and 3 exons of SOD3, except for 3 of 20 cases with polymorphisms for exon 3 of SOD1. Intense nuclear immunoreactivity for 8-hydroxydeoxyguanosine was present in fewer than 3% of epithelial cells, with no apparent differences among benign epithelium, PIN, and cancer.

CONCLUSIONS

SOD1, SOD2, and catalase had lower expression in PIN and prostate carcinoma than in benign epithelium. The number of immunoreactive cells in PIN was similar to cancer, indicating that these are closely related. Enzyme activities were variable, with no difference between benign epithelial cells and cancer, although this lack of change in enzyme activity could have been due to the presence of contaminating benign cells within the cancer specimens. The results of reactive oxygen species damage were found only in the epithelium and not in the stroma. Expression of the DNA adduct 8-hydroxydeoxyguanosine was present in fewer than 3% of cells, with no apparent differences among benign epithelium, PIN, and cancer. These findings suggest that oxidative stress is an early event in carcinogenesis.

Independent origin of multiple foci of prostatic intraepithelial neoplasia: comparison with matched foci of prostate carcinoma

BACKGROUND

Prostate carcinoma usually is heterogeneous and multifocal, with diverse clinical and morphologic manifestations. Understanding of the molecular basis for this heterogeneity is limited, particularly for the putative precursor, high grade prostatic intraepithelial neoplasia (PIN). In this study, the authors attempted to determine the genetic relation between multiple foci of PIN and matched foci of carcinoma, and whether they are independent in origin.

METHODS

The distribution and prevalence of allelic imbalance at 6 microsatellite polymorphic markers on chromosomes 7q, 8p, 8q, and 18q were examined in 84 microscopically excised PIN foci (mean, 1.6 foci/case) and 95 foci of prostate carcinoma (mean, 1.8 foci/case) from 52 completely embedded, mapped whole mount prostates.

RESULTS

PIN contained a lower overall proportion of allelic imbalance than matched prostate carcinoma foci for the 6 polymorphic microsatellite markers (65% vs. 82%), but this difference was not significant. The rate of allelic imbalance in PIN was similar to that in prostate carcinoma at 5 of 6 loci studied; the exception, D18S34 (18q12.2-12.3), had a significantly lower rate of allelic imbalance in PIN than in prostate carcinoma (19% vs. 52%), suggesting that genetic alterations in this chromosomal region may be important in carcinogenesis. Of 22 cases with allelic imbalance in at least 1 focus of PIN and 1 focus of prostate carcinoma, 21 informative cases (95%) showed a similar pattern of allelic imbalance at > or = 1 markers in the matched PIN and prostate carcinoma foci. Significant genetic heterogeneity was observed in both PIN and prostate carcinoma. Allelic imbalance was observed in at least 1 focus in 11 of 25 cases with multiple foci of PIN (44%) and 20 of 25 cases with multiple foci of prostate carcinoma (80%). There was no significant correlation between allelic imbalance and pathologic stage or tumor grade.

CONCLUSIONS

Our findings indicate that multiple foci of PIN arise independently within the same prostate. This observation suggests that a field effect underlies prostatic neoplasia. Multiple foci of prostate carcinoma also often arise independently, lending additional support for this hypothesis. The strong genetic similarities between PIN and prostate carcinoma strongly suggest that evolution and clonal expansion of PIN may account for the multifocal etiology of carcinomas.

Bactericidal monoclonal antibodies that define unique meningococcal B polysaccharide epitopes that do not cross-react with human polysialic acid

The poor immunogenicity of the Neisseria meningitidis group B polysaccharide capsule, a homopolymer of alpha(2-->8) sialic acid, has been attributed to immunologic tolerance induced by prenatal exposure to host polysialyated glycoproteins. Substitution of N-propionyl (N-Pr) for N-acetyl groups on the meningococcal B polysaccharide, and conjugation of the resulting polysaccharide to a protein carrier, have been reported to yield a conjugate vaccine that elicits protective Abs with minimal autoantibody activity. To characterize the protective epitopes on the derivatized polysaccharide, we isolated 30 anti-N-Pr meningococcal B polysaccharide mAbs. These Abs were heterogeneous with respect to complement-mediated bactericidal activity, fine antigenic specificity, and autoantibody activity as defined by binding to the neuroblastoma cell line, CHP-134, which expresses long-chain a(2-->8)-linked polysialic acid. Eighteen of the Abs could activate complement-mediated bacteriolysis. Seven of these 18 Abs cross-reacted with N-acetyl meningococcal B polysaccharide by ELISA and had strong autoantibody activity. Thus, N-Pr meningococcal B polysaccharide conjugate vaccine has the potential to elicit autoantibodies. However, 7 of the 18 bactericidal mAbs had no detectable autoantibody activity. These Abs may be useful for the identification of molecular mimetics capable of eliciting protective Abs specific to the bacteria, without the risk of evoking autoimmune disease.

Atypical adenomatous hyperplasia of the prostate: a premalignant lesion?

To better understand genetic alterations in atypical adenomatous hyperplasia (AAH) of the prostate, we examined the prevalence of allelic imbalance at 5 microsatellite polymorphic markers on chromosomes 7q31-35, 8p12-21, 8p22, 8q22.2, and 18q12.2 from 15 patients with AAH. DNA samples were obtained from formalin-fixed paraffin-embedded sections using tissue microdissection. We found allelic imbalance in 7 of 15 (47%) cases of AAH. Genetic changes that commonly occur in early prostatic carcinogenesis and prostate carcinoma are found in AAH. Current data provide evidence of a genetic link between some cases of AAH and carcinoma.

Allelic imbalance and microsatellite instability in prostatic adenocarcinoma

Although prostate cancer is one of the most common malignancies of males in Western countries, relatively little is known about the molecular mechanisms involved in tumor initiation and progression. Allelic loss studies have suggested the involvement of multiple tumor suppressor genes (TSGs), but few detailed studies of all chromosomes have been performed. In an effort to localize and identify candidate TSGs, we performed allelic imbalance (AI) studies on 55 prostate cancers, using 135 polymorphic microsatellite markers. For the entire chromosome. AI ranged from a low of 0% on chromosomes 14 and 20 to a high of 71% on chromosome 8. Chromosomal regions demonstrating at least twice the background frequency of AI (ranging from 20 to 69%) included 5q, 6q, 7q, 8p, 13, l6q, l8q, and 21. In addition, AI was examined for association with a number of clinicopathological parameters. AI on chromosomes 7 and 16 were each associated with greater age at diagnosis (P = 0.009 and 0.001, respectively), and AI on chromosomes 10, 16, and 18 was associated with aneuploidy/tetraploidy (P = 0.037, 0.013, and 0.054, respectively). Furthermore, AI on chromosome 5 was associated with a higher pathological stage (P = 0.021) and on chromosome 8 and 16 with a higher Gleason score (P = 0.027 and 0.041, respectively). No tumor exhibited a phenotype of widespread microsatellite instability. These results indicate that there likely exist multiple sites harboring candidate TSG in prostate cancer, some of which may have important clinical implications, and which argue against widespread microsatellite instability.

Analyses of two azo dyes by high-performance liquid chromatography

Two structurally similar azo dyes, Direct Blue No. 6 and Direct Blue No. 15, are analyzed by separate reversed-phase high-performance liquid chromatographic (HPLC) systems utilizing a dual-wavelength UV/visible detector at 254 and 546 nm. Each dye contains more than 35 impurity peaks. Different lots of each dye are compared by means of their respective chromatographic profiles. The system used to obtain a chromatographic profile for each dye is adapted to make comparisons of the major component in different lots by an internal standard method. These methods are reproducible, giving relative standard deviations ranging from approximately 1 to 5%. These HPLC systems are adaptable for the analysis of other structurally similar dyes.