bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of excess corticosterone on NADPH generating enzymes and glucose oxidation in Leydig cells of adult rats
Authors: Kavitha T Subramanian , Parthasarathy C , Sivakumar R , Badrinarayanan R , Balasubramanian K
Published: March 2006

Clinical and experimental studies have shown the adverse effects of excess glucocorticoid on testicular testosterone production. The NADPH co-enzyme has been recognized as an important factor that regulates several steps in steroidogenesis, while glucose oxidation acts as a limiting factor on testicular testosterone production. Nevertheless, the impact of excess corticosterone, the stress hormone on testicular NADPH availability and glucose oxidation is unknown. Therefore, the present study was designed to assess the specific effects of excess corticosterone on Leydig cell NADPH generating enzymes and glucose oxidation. Adult Wistar rats (200–250 g, b.w.) were treated with corticosterone-21-acetate (2 mg/100 g, b.w., i.m., twice daily) for 10 days and corticosterone-21-acetate plus luteinizing hormone (LH) (100 mg/kg b.w., i.m., daily) for 10 days. After the treatment period, experimental animals and controls were killed, blood was collected and the sera separated for testosterone assay. Testes were removed and Leydig cells were isolated, purified and used for estimating the specific activity of NADPH generating enzymes and 14C-glucose oxidation. Serum testosterone, Leydig cellular 14C-glucose oxidation and the specific activities of 6-phosphogluconate dehydrogenase (6-PGDH), NADP-iso-citrate dehydrogenase (ICDH) and malic enzyme were significantly decreased in corticosterone-treated rats. Coadministration of LH with corticosterone maintained the specific activities of 6-PGDH and ICDH and 14C-glucose oxidation at control level. Nevertheless, serum testosterone and Leydig cellular malic enzyme activity showed a significant decrease in these rats. In conclusion, the inhibitory effects of excess corticosterone on Leydig cell steroidogenesis are mediated through impaired glucose oxidation and defective NADPH generation. Co-administration of LH with corticosterone failed to prevent the decrease in serum testosterone and Leydig cell malic enzyme activity, suggesting the dominant inhibitory effects of excess corticosterone.
A framework for using epidemiological data for risk assessment
Authors: Swaen G MH
Published: March 2006

Data on health effects from human exposure to chemicals provide the most direct information for risk assessment. Despite their clear relevance for risk assessment and despite the frequently made statements by regulatory bodies to use epidemiological data whenever deemed appropriate, they are not always optimally used. In this article, a framework for using epidemiological data in risk assessment is presented. Before using an epidemiologic study as the basis for risk assessment, its quality must be evaluated. The quality criteria for such a study strongly depends on the type of association between the chemical and health effect in terms of its specificity and latency period. The framework is built on the type of health effect under consideration, whether it is a specific or non-specific effect and time window of the effect, whether it is an acute, sub-acute or long-term effect. Specificity and latency are aspects that have a great impact on the choice of research design and quality criteria that must be met in order to produce reliable results appropriate for risk assessment purposes.

Although expert judgement will always play an important role, the framework can help to assess if a set of epidemiological data are sufficiently reliable to serve as the basis for the derivation of health-based exposure limits. The limitations and suitability to use for risk assessment of epidemiologic studies is more likely to be the result of poor or insufficient exposure data than of poor or unreliable health effect information. It is concluded that the value of epidemiologic data not only depends on its intrinsic quality, but also on the type of health effects under consideration. In this respect, the specificity and latency play an important role.
Terminalia chebula (fruit) prevents liver toxicity caused by sub-chronic administration of rifampicin, isoniazid and pyrazinamide in combination
Authors: Tasduq S A , Singh K , Satti N K , Gupta D K , Suri K A , Johri R K
Published: March 2006

Terminalia chebula Gertn. (Combetraceae) is an important herbal drug in Ayurvedic pharmacopea. In the present study, a 95% ethanolic extract of T. chebula (fruit) (TC extract), which was chemically characterized on the basis of chebuloside II as a marker, was investigated for hepatoprotective activity against anti-tuberculosis (anti-TB) drug-induced toxicity. TC extract was found to prevent the hepatotoxicity caused by the administration of rifampicin (RIF), isoniazid (INH) and pyrazinamide (PZA) (in combination) in a sub-chronic mode (12 weeks). The hepatoprotective effect of TC extract could be attributed to its prominent anti-oxidative and membrane stabilizing activities. The changes in biochemical observations were supported by histological profile.
Increased morbidity and mortality in acute human organophosphate-poisoned patients treated by oximes: a meta-analysis of clinical trials
Authors: Rahimi Roja , Nikfar Shekoufeh , Abdollahi Mohammad
Published: March 2006

Organophosphates are one of the most common causes of poisoning, especially in the Third world, with high morbidity and mortality. The treatment of this type of poisoning involves the use of atropine and oximes. Atropine has been used successfully in large doses to counteract the muscarinic effects of organophosphate poisoning, but the efficacy of oximes in the management of this poisoning remains under question. In this study, we undertook a meta-analysis by reviewing all clinical trials to evaluate the efficacy of oximes in the management of organophosphate poisoning. The databases of PUBMED, EMBASE, Cochrane, SCOPUS, and the search engine of Google were searched for all clinical trials on the use of oximes in organophosphate poisoning. The inclusion criteria were death, development of intermediate syndrome, and need for ventilation. Six clinical trials met the inclusion criteria and were included in the metaanalysis. The x2 tests for heterogeneity (P–0.25, 0.16, and 0.33, respectively) indicated that the included studies were not significantly heterogeneous and could be combined. A significant relative risk (P–0.0017) for death among oxime-exposed was 2.17 (95% CI of 1.34 / 3.51). The ‘need for ventilation’ in patients who received oxime was higher (P–0.03) than those who did not receive oxime with a relative risk of 1.53 (1.16 / 2.02). The incidence of ‘intermediate syndrome’ for oximeexposed patients was significantly higher (P–0.01) than oxime non-exposed patients with a relative risk of 1.57 (95% CI 1.11 / 2.11). It can be concluded that oximes are not effective in the management of organophosphate-poisoned patients and, surprisingly, they can be dangerous and worsen the patient's clinical situation.
Effects of therapeutic agents on cellular respiration as an indication of metabolic activity
Authors: Ishikawa T , Zhu B-L , Maeda H
Published: March 2006

Animal experiments are indispensable in the investigation of the toxicity of drugs on cells, but may not be preferred for ethical reasons and sensitivity. As an alternative procedure, we investigated the susceptibility of cells to drugs using the effect on cellular respiration as an indicator of cell activity (toxicity). The primary cultures (cell lines) used in this study included human fetal myocardial cells, skeletal muscle cells, nerve cells, hypophyseal cells, epithelial cells of gastric mucosa, lymphocytes, hepatocytes, pancreatic (exocrine) cells, renal tubular epithelial cells and fetal adrenal cortex cells, which were obtained from the American Type Culture Collection (ATCC). The drugs used were diazepam, haloperidol and levomepromazine maleate (psychoactive drugs), cisplatin and doxorubicin hydrochloride (anticancer agents). The cells were used at a density of 2–106 cells/2 mL of growth medium and, to test the susceptibility, each drug was prepared at a concentration of 10 g/mL. Experiment results indicated that, even with the same drug, sensitivity was markedly different depending on the cell lines. Cardiac muscle cells showed the strongest respiratory inhibition by Serenace and were least inhibited by Hirnamin. The highest sensitivity to Cercine was noted for neurons, while gastric mucosa cells had almost no sensitivity. Sensitivity to Serenace, which was expected to have a strong nerve action, was higher in myocardial cells instead. In the present study, we suggested the possibility of studying individual differences in drug sensitivity through investigation of toxicity in each organ as opposed to toxicity in the individual. In addition, Serenace, which was developed as a neurotopic agent, showed a higher toxicity in cardiac muscle cells than in neurons. This finding appeared noteworthy, not only for forensic toxicology, but also for clinical practice and drug development.
Risk of Second Malignancy After Non-Hodgkin's Lymphoma: A British Cohort Study
Authors: Mudie Nadejda Y. , Swerdlow Anthony J. , Higgins Craig D. , Smith Paul , Qiao Zongkai , Hancock Barry W. , Hoskin Peter J. , Linch David C.
Published: March 2006

Purpose

To assess long-term site-specific risks of second malignancy following non-Hodgkin's lymphoma (NHL) in relation to treatment and demographic factors.

Patients and Methods

A cohort of 2,456 patients with NHL who were first treated from 1973 to 2000 and were younger than 60 years from centers in the British National Lymphoma Investigation were observed, and occurrences of second malignancy was compared with expectations based on general population cancer rates in England and Wales.

Results

In total, 123 second malignancies occurred. Relative risks (RRs) were significantly elevated for all malignancies combined (RR = 1.3; 95% CI, 1.1 to 1.6) and for leukemia (RR = 8.8; 95% CI, 5.1 to 14.1) and lung cancer (RR = 1.6; 95% CI, 1.1 to 2.3). RRs of malignancy overall diminished significantly with increasing age at first treatment. Leukemia risk was significantly increased after chemotherapy (RR = 10.5; 95% CI, 5.0 to 19.3) and mixed-modality treatment (RR = 13.0; 95% CI, 5.2 to 26.7). Relative risks of lung (RR = 1.9; 95% CI, 1.1 to 3.1) and colorectal (RR = 2.1; 95% CI, 1.1 to 3.6) cancers were significantly raised following chemotherapy.

Conclusion

NHL patients are at elevated risk of developing second malignancy, particularly leukemia and lung cancer. The relative risk is greater with patients who are younger at first treatment. Chemotherapy predisposes patients toan increased risk of leukemia, and possibly lung and colorectal cancers. The role of specific drug treatments in the etiology of solid cancers after NHL deserves further investigation.
Pentostatin, Cyclophosphamide, and Rituximab Is an Active, Well-Tolerated Regimen for Patients With Previously Treated Chronic Lymphocytic Leukemia
Authors: Lamanna Nicole , Kalaycio Matt , Maslak Peter , Jurcic Joseph G. , Heaney Mark , Brentjens Renier , Zelenetz Andrew D. , Horgan Denise , Gencarelli Alison , Panageas Katherine S. , Scheinberg David A. , Weiss Mark A.
Published: March 2006

Purpose

Purine analogs and alkylators are important agents for treating chronic lymphocytic leukemia (CLL). Early studies combining fludarabine and chlorambucil were abandoned owing to increased toxicity from overlapping myelosuppression and immunosuppression. Of the purine analogs active in CLL, pentostatin appears to be the least myelosuppressive. We previously reported that pentostatin and cyclophosphamide (PC) is active and well-tolerated in patients with relapsed or refractory CLL. Subsequently, we added rituximab, and now report on this three-drug combination.

Patients and Methods

We treated 46 patients with either previously treated CLL (32 patients) or other low-grade B-cell neoplasms (14 patients). Patients received pentostatin 4 mg/m2, cyclophosphamide 600 mg/m2, and rituximab 375 mg/m2 (PCR). All drugs were administered on the same day (rituximab omitted from cycle 1), and patients received six cycles at 3-week intervals. Filgrastim, sulfamethoxazole/trimethoprim, and acyclovir were administered prophylactically.

Results

The median age was 62 years (range, 30 to 80 years). The median number of prior regimens was two (range, one to seven). For CLL patients, there were 24 responses (75%), including eight complete responses (25%). In fludarabine-refractory patients, 75% responded. Toxicity was acceptable, with grade 3/4 infections (including fever of unknown origin) in 28%. The regimen was well tolerated, with 72% of patients receiving the planned treatment at full dose.

Conclusion

PCR is safe and effective in previously treated patients with CLL. In comparison with our prior two-drug regimen, we find that rituximab did not seem to add significantly to the toxicity, but did appear to confer a survival advantage. Based on these results, we are currently studying PCR as initial therapy for patients with CLL.
Single Nucleotide Polymorphisms of RecQ1, RAD54L, and ATM Genes Are Associated With Reduced Survival of Pancreatic Cancer
Authors: Li Donghui , Frazier Marsha , Evans Douglas B. , Hess Kenneth R. , Crane Christopher H. , Jiao Li , Abbruzzese James L.
Published: March 2006

Purpose

Our goal was to determine whether single nucleotide polymorphisms (SNPs) in DNA repair genes influence the clinical outcome of pancreatic cancer.

Patients and Methods

We evaluated 13 SNPs of eight DNA damage response and repair genes in 92 patients with potentially resectable pancreatic adenocarcinoma. All patients were treated with neoadjuvant concurrent gemcitabine and radiotherapy with or without a component of induction gemcitabine/cisplatin at The University of Texas M.D. Anderson Cancer Center (Houston, TX) from February 1999 to August 2004 and observed through August 2005. Response to the pretreatment was assessed by evaluating time to tumor progression and overall survival. Kaplan-Meier plot, log-rank test, and Cox regression were used to compare survival of patients according to genotype.

Results

The RecQ1 A159C, RAD54L C157T, XRCC1 R194W, and ATM T77C genotypes had a significant effect on the overall survival with log-rank P values of .001, .004, .001, and .02, respectively. A strong combined effect of the four genotypes was observed. Patients with none of the adverse genotypes had a mean survival time of 62.1 months, and those with one, two, or three or more at-risk alleles had median survival times of 27.5, 14.4, and 9.9 months, respectively (log-rank P < .001). There is a significant interaction between the RecQ1 gene and other genotypes. All four genes except XRCC1 remained as independent predictors of survival in multivariate Cox regression models adjusted for other clinical predictors.

Conclusion

These observations support the hypothesis that polymorphic variants of DNA repair genes affect clinical prognosis of patients with pancreatic cancer.
Prospective Study of Survival Outcomes in Non-Hodgkin's Lymphoma Patients With Rheumatoid Arthritis
Authors: Mikuls Ted R. , Endo Justin O. , Puumala Susan E. , Aoun Patricia A. , Black Natalie A. , O'Dell James R. , Stoner Julie A. , Boilesen Eugene C. , Bast Martin A. , Bergman Debra A. , Ristow Kay M. , Ooi Melissa , Armitage James O. , Habermann Thomas M.
Published: March 2006

Purpose

Although preliminary studies suggest that non-Hodgkin's lymphoma (NHL) complicating rheumatoid arthritis (RA) may be a clinically distinct entity compared with that occurring in the general population, studies examining the impact of antecedent RA on survival are limited. In this prospective study, we examined the association of RA with survival in patients with NHL.

Patients and Methods

Using two large lymphoma registries, we identified patients with evidence of RA preceding NHL. Survival in RA patients was compared with that of controls using proportional hazards regression, adjusting for the effects of age, sex, lymphoma diagnosis-to-treatment lag time, calendar year, International Prognostic Index score, and NHL grade.

Results

The frequency of NHL subtypes was similar in RA patients (n = 65) and controls (n = 1,530). Compared with controls, RA patients with NHL had similar overall survival (hazard ratio [HR] = 0.95; 95% CI, 0.70 to 1.30) but were at lower risk of lymphoma progression or relapse (HR = 0.41; 95% CI, 0.25 to 0.68) or death related to lymphoma or its treatment (HR = 0.60; 95% CI, 0.37 to 0.98), but were more than twice as likely to die from causes unrelated to lymphoma (HR = 2.16; 95% CI, 1.33 to 3.50).

Conclusion

RA is associated with improved NHL-related outcomes, including a 40% reduced risk of death occurring as a result of lymphoma or its treatment and approximately a 60% lower risk of lymphoma relapse or progression compared with non-RA controls. However, the survival advantage gained in RA from the acquisition of lymphomas with favorable prognoses is negated through an increased mortality from other comorbid conditions.
Ranolazine: A New Approach to Management of Patients with Angina
Authors: Tafreshi Mohammad J , Fisher Edward
Published: March 2006

Objective:

To review the pharmacology, pharmacokinetics, and clinical efficacy of ranolazine for the treatment of chronic stable angina.

Data Sources:

MEDLINE was searched (1966–February 2006) using the English-language key terms ranolazine and chronic stable angina. Additional studies were identified from the bibliographies of the reviewed literature.

Study Selection and Data Extraction:

Studies evaluating ranolazine, alone or in combination with other agents, were incorporated in this review.

Data Synthesis:

Ranolazine is a metabolic modulator designed to improve cardiac energy availability and cardiac metabolism. It is believed to be a partial fatty acid oxidation inhibitor. Ranolazine has been shown to improve exercise duration and time to anginal attacks without significantly affecting heart rate or blood pressure. Adverse effects of ranolazine are reported to be dose related. The elimination half-life of ranolazine is estimated to be between 1.4 and 1.9 hours for the immediate-release and 7 hours for sustained-release preparations.

Conclusions:

Ranolazine has a unique mechanism of action that is different from that of conventional agents. It has been studied as monotherapy or in combination with other commonly prescribed agents. It appears that ranolazine has a promising safety data profile and does not affect hemodynamic parameters. At this point, although ranolazine should not be used in place of conventional therapy, it appears that ranolazine may be considered in the management of symptomatic patients when standard antianginal medications are not tolerated or are ineffective.
Risk of Clozapine-Associated Agranulocytosis and Mandatory White Blood Cell Monitoring
Authors: Schulte Peter FJ
Published: March 2006

Objective:

To provide information for physicians and patients on which to base a decision as to whether to stop mandatory blood testing.

Data Sources:

Articles on drug-induced blood dyscrasias were identified by searches of MEDLINE (1966—September 2005) and review of their bibliographies. Novartis was asked to provide additional data on clozapine, leukopenia, agranulocytosis, and suicidality.

Study Selection and Data Extraction:

Data on the chance of clozapine-induced leukopenia and agranulocytosis were combined with data about possible fatality and compared with the risks associated with other medications and with life in general.

Data Synthesis:

The chance of clozapine-induced leukopenia or agranulocytosis decreases exponentially over time. In the US, the chance in the second 6 months of treatment is 0.70/1000 patient-years and, after the first year, 0.39/1000 patient-years. The case fatality rate of clozapine-induced agranulocytosis is estimated as 4.2–16%, depending on whether a granulocyte colony-stimulating factor is used. Nevertheless, treatment with clozapine reduces overall mortality, probably because it reduces suicidality.

Conclusions:

After at least 6 months' treatment with clozapine, the mortality involved in stopping white blood cell monitoring is about the same as the mortality associated with other medications, such as mianserin or phenylbutazone, and with life in general (traffic or occupational accident). If the patient has been well informed and wishes to stop the monitoring, it is a medically justifiable option to do so and is preferable to stopping treatment with clozapine since this drug reduces overall mortality.
Discordance Between Availability of Pharmacogenetics Studies and Pharmacogenetics-Based Prescribing Information for the Top 200 Drugs
Authors: Zineh Issam , Pebanco Glenn D , Aquilante Christina L , Gerhard Tobias , Beitelshees Amber L , Beasley Bach Nhi , Hartzema Abraham G
Published: March 2006

Background:

Despite growing numbers of pharmacogenetics studies, little pharmacogenetics-based prescribing information is available to practitioners. It is possible that the lack of prescribing data for commonly used drugs is due to a paucity of evidence-based pharmacogenetics literature for these agents.

Objective:

To investigate the relationship between pharmacogenetics prescribing data in drug package inserts (Pls) and pharmacogenetics research literature for agents represented in the top 200 prescribed drugs for 2003.

Methods:

A PubMed search (to August 7, 2004) was performed to identify pharmacogenetics studies relevant to the top 200 drugs. These data were compared with Pls for drugs in the top 200 list that contained pharmacogenetics prescribing information.

Results:

Pharmacogenetics data in the literature were available for 71.3% of the top 200 drugs. The gene involved coded for a drug-metabolizing enzyme in 34.5% of the literature sampled. The remaining 65.5% of the pharmacogenetics studies contained information largely related to genetic variability in target proteins and drug transporters. Three drugs with Pls containing pharmacogenetics prescribing information deemed to be useful to guide therapy were in the top 200 list (celecoxib, fluoxetine, pantoprazole). There was no consensus on the strength of association between genetic variability and drug response for these agents.

Conclusions:

The lack of specific pharmacogenetics-based prescribing information in Pls for commonly used drugs does not seem to be related to a paucity of pharmacogenetics data in the research literature. Rather, other factors including, but not limited to, the uncertain clinical relevance of genetic associations may make practical prescribing recommendations difficult.
Update on Prevention of Meningococcal Disease: Focus on Tetravalent Meningococcal Conjugate Vaccine
Authors: Mehlhorn Allana J , Balcer Holly E , Sucher Brandon J
Published: March 2006

Objective:

To review the immunogenicity, efficacy, safety, and new recommendations for routine use of the tetravalent meningococcal conjugate vaccine (MCV4).

Data Sources:

A MEDLINE search (1966–June 2005) was conducted using the key words Neisseria meningitidis and meningococcal vaccines for clinical trials limited to human research published in the English language.

Study Selection and Data Extraction:

Randomized, controlled, multicenter trials were reviewed and included to evaluate the safety and efficacy of MCV4. Additional open-label trials on the use of MCV4 in children less than 24 months of age are included since these studies may be used to support the approval of the vaccine for use in children. Literature on epidemiology and pathology of meningococcal meningitis and the Advisory Committee on Immunization Practices (ACIP) recommendations were also reviewed.

Data Synthesis:

MCV4 is approved for active immunization of adolescents and adults between the ages of 11 and 55 years for the prevention of disease caused by N. meningitidis serogroups A, C, Y, and W-135. MCV4 has been shown to have comparable immunogenicity and a similar adverse reaction profile to the tetravalent meningococcal polysaccharide vaccine (MPSV4). It is expected that MCV4 will provide a longer duration of protection from meningococcal disease than MPSV4.

Conclusions:

Based on published immunogenicity, efficacy, and safety data, as well as the recent recommendations by the ACIP for its routine use, MCV4 is the preferred meningococcal vaccine for persons between 11 and 55 years of age and should be included on pharmacy formularies.
Evaluation of a new Sebia kit for analysis of hemoglobin fractions and variants on the Capillarys® system
Authors: Louahabi Amal , Philippe Marianne , Lali Salah , Wallemacq Pierre , Maisin Diane
Published: March 2006

We evaluated the analytical performances of the new Sebia kit for quantification of hemoglobin fractions (HbA, HbF and HbA
Recommendation for measuring and reporting chloride by ISEs in undiluted serum, plasma or blood: International Federation of Clinical Chemistry and Laboratory Medicine (IFCC): IFCC Scientific Division, Committee on Point of Care Testing and Working Group on Selective Electrodes
Authors: Rayana Mohammed C. Ben , Burnett Robert W. , Covington Arthur K. , D'Orazio Paul , Fogh-Andersen Niels , Jacobs Ellis , Kataky Ritu , Külpmann Wolf R. , Kuwa Katsuhiko , Larsson Lasse , Lewenstam Andrzej , Maas Anton H.J. , Mager Gerhard , Naskalski Jerzy W. , Okorodudu Anthony O. , Ritter Christoph , St John Andrew
Published: March 2006

The proposed recommendation for measuring and reporting chloride in undiluted plasma or blood by ion-selective electrodes (ISEs) will provide results that are identical to chloride concentrations measured by coulometry for standardized normal plasma or blood samples. It is applicable to all current ISEs dedicated to chloride measurement in undiluted samples that meet the requirements. However, in samples with reduced water concentration, results by coulometry are lower than by ion-selective electrode due to volume displacement. The quantity measured by this standardized ISE procedure is called the ionized chloride concentration. It may be clinically more relevant than the chloride concentration as determined by coulometry, photometry or by ISE after dilution of the sample.
The influence of lignin chemistry and ultrastructure on the pulping efficiency of clonal aspen (Populus tremuloides Michx.)
Authors: Stewart Jaclyn J. , Kadla John F. , Mansfield Shawn D.
Published: March 2006

The variation in wood chemistry among aspen clones of similar age, harvested from a common site in northern British Columbia, Canada, was evaluated. The aspen clones were evaluated for ease of chemical pulping and differed by as much as 4.5% in pulp yield at a common H-factor. The results demonstrate both the need for understanding the resource and the substantial opportunities that exists in natural population of trees for selecting superior clones for reforestation and afforestation. The syringyl/guaiacyl ratio, as determined by nitrobenzene oxidation, was directly correlated with the ease of pulping, whereas thioacidolysis results were not as predictive. These results were supported by quantitative NMR analysis, which demonstrated differences in the amount of β-O-4/Ar groups and the degree of condensation. Furthermore, it was shown that, in addition to total lignin content, which differed by as much as 5%, structural differences in the lignin may influence pulping efficacy. Among the other parameters evaluated, the distribution of molecular mass and methoxyl content is relevant for pulping. More specifically, among the fractions isolated in this study [milled wood lignin (MWL), MWELsol, and MWELinsol], the insoluble fraction was the most indicative of the pulping efficiency.
Elucidating carboxylic acid profiles for extended oxygen delignification of high-kappa softwood kraft pulps
Authors: Zhang Dongcheng , Pu Yunqiao , Chai Xing-Sheng , Naithani Ved , Jameel Hasan , Ragauskas Arthur J.
Published: March 2006

Two laboratory high-lignin-content softwood (SW) kraft pulps with kappa values of 48.0 and 49.5, prepared by cooking at high and low active alkali (AA), were used for the study of fiber charge development during two-stage oxygen delignification with inter-stage washing (OwO). It was established that the first oxygen delignification (O) stage increased total fiber charge by 2–4%, and further O-delignification via a second O-stage led to a 3–18% decrease in total fiber charge. Carboxylic acid content in pulp holocelluloses decreased by 12–26% with respect to a 35–70% kappa number reduction due to an O and OwO stage of delignification for high and low AA cooked SW kraft pulps. After an OwO-stage delignification, the residual lignin was found to exhibit a 50–100% increase in carboxylic acid content. 13C NMR spectral data for the residual lignin samples indicated that the unconjugated/conjugated acid ratio was approximately (3–4):1. Generally, the carboxylic acid content in low AA cooked softwood kraft pulp and the corresponding oxygen-delignified pulps was systematically higher (13–23%) than that in high AA cooked SW kraft pulp and the corresponding oxygen-delignified pulps. The experimental results also demonstrated that maximum acid-group content in total fiber occurred after 45–50% oxygen delignification of the SW kraft pulps studied.
Evidence for the formation of lignin-hexenuronic acid-xylan complexes during modified kraft pulping processes
Authors: Jiang Zhi-Hua , Bouchard Jean , Berry Richard
Published: March 2006

The finding that hexenuronic acid (HexA) groups can be selectively removed from kraft pulps by acid hydrolysis has provided an opportunity to reduce bleaching chemicals. However, there is evidence that the acid hydrolysis is not uniform. In this report, we evaluate the kinetics of acid hydrolysis of HexA in a xylan sample enriched with HexA, a conventional kraft pulp, and three modified kraft pulps: anthraquinone pulp (Kraft-AQ), polysulfide pulp (PS), and polysulfide-anthraquinone pulp (PS-AQ). We found that HexA present in the xylan and conventional kraft pulp behaved similarly toward the acid hydrolysis throughout. On the other hand, HexA present in the Kraft-AQ, PS-AQ and PS pulps was heterogeneous toward acid hydrolysis and the reaction can be separated into two pseudo-first-order kinetic phases, each of which has a different rate constant. The kinetic data provide evidence for the formation of lignin-HexA-xylan complexes during modified kraft pulping processes.
Critical comparison of methods for surface coverage by extractives and lignin in pulps by X-ray photoelectron spectroscopy (XPS)
Authors: Fardim Pedro , Hultén Anette Heijnesson , Boisvert Jean-Phillippe , Johansson Leena-Sisko , Ernstsson Marie , Campbell Joseph M. , Lejeune Agnes , Holmbom Bjarne , Laine Janne , Gray Derek
Published: March 2006

Different methods for estimation of the surface coverage by extractives and lignin were critically compared. For data collection, four state-of-the-art X-ray photoelectron spectroscopy (XPS) instruments located in four different laboratories were used. Hand sheets of one mechanical and two chemical pulp samples were prepared in one laboratory and distributed among the other participants. The XPS results based on O/C ratios and curve fitting of the C 1s peak had very good intra- and interlaboratory variation for extracted and non-extracted pulp samples. The estimations of surface coverage by extractives and lignin also had acceptable intra- and interlaboratory variation. However, significant differences were observed between the results for the various methods. Estimation of surface coverage by extractives based on O/C ratios was much higher than that based on the C1 component analysis in the case of mechanical and unbleached chemical pulp. The surface coverage by lignin of mechanical pulp was reproducibly detected based on O/C ratios, C1 component analysis and by labelling with mercury acetate. The same data were, however, rather scattered if they were collected with these three methods for bleached and unbleached chemical pulp. In spite of the differences, similar trends regarding the pulp type could be observed. We interpret the results as indicating that the surface coverage for both extractives and lignin should not be considered as absolute “true” values, but rather as relative values, which are reliable only for comparison of samples for the same instrument. Even for relative comparisons, we recommend the selection of a strict experimental set-up for spectral acquisition and data treatment when applying any of the instruments and calculation models currently available.
Improvement of formaldehyde-scavenging ability of condensed tannins by ammonia treatment
Authors: Hashida Koh , Ohara Seiji , Makino Rei
Published: March 2006

Condensed tannins have formaldehyde gas-scavenging ability. Tannins consisting of phloroglucinol-type A-rings, such as prodelphinidin and procyanidin, had higher formaldehyde-scavenging ability than those consisting of resorcinol-type A-rings, such as prorobietinidin and profisetinidin. This ability was markedly improved by ammonia treatment. The increase in formaldehyde-scavenging ability was especially notable in the case of condensed tannins with a high ratio of pyrogallol-type B-rings, such as prorobietinidin and prodelphinidin. To clarify the factors affecting improvement of the formaldehyde-scavenging ability by ammonia treatment, the reaction behavior of condensed tannins during ammonia treatment was studied. Analyses using 13C-NMR and on-line methylation pyrolysis/gas chromatography/mass spectrometry revealed that on treatment of condensed tannins with ammonia, amino-substitution at C-4′ of the pyrogallol-type B-ring occurred to form a 4′-amino-3′,5′-dihydroxybenzene-type B-ring. It can be assumed that the introduction of a 4′-amino-3′,5′-dihydroxybenzene-type B-ring into the tannin molecule results in improved formaldehyde-scavenging ability.
Transverse anisotropy of compressive failure in European oak – a digital speckle photography study
Authors: Ljungdahl Jonas , Berglund Lars A. , Burman Magnus
Published: March 2006

The mechanical behaviour of European oak (Quercus robur L.) was studied in radial and tangential compression. Young's modulus and the yield strength were approximately 1.7- and 1.6-fold higher, respectively, in the radial direction. Strain fields were determined by digital speckle photography (DSP). Strains and the effective Poisson ratio could be determined separately in earlywood and latewood during deformation and failure events. In radial compression, strain data showed that rays contributed significantly to the high modulus. In addition, multiseriate ray microbuckling was observed to control yield strength. The microbuckling was localised in the low-density earlywood. In tangential compression, yield strength was controlled by vessel collapse in the low-density regions of the latewood. The strain field data provide direct evidence that the rays are the main micro-structural factor controlling transverse anisotropy in European oak.
Temperature-drop sensor for determination of drying curves in conventional lumber drying
Authors: Elustondo Diego , Oliveira Luiz , Lister Peter
Published: March 2006

Conventional lumber drying is carried out by forcing hot air to flow across a pile of lumber layers separated by wood strips. The airflow provides the heat required to warm up the lumber and produce the moisture evaporation and, in theory, the difference in temperature at each side of the load can be used to estimate the evaporation rate. The main problem with this approach is that typical temperature sensors that are installed in conventional kilns are not accurate enough to measure the temperature drop across the load during periods of low evaporation. In this paper, a new sensor to measure the temperature drop across the load is proposed and tested in three experimental drying runs of 2″×6″ spruce-pine lumber. The results demonstrate that after calibration, the temperature drop across the load can be used to determine drying curves in conventional lumber drying. In the particular case of this study, calibration was performed by multiplying the experimental temperature drop across the load by a constant factor, which was adjusted by identifying the correction factor that best simulated the experimental green moisture content of the three lumber charges.
Preparation of acetoacetylated wood meal and its properties. Part 1. Preparation of parameter and preliminary evaluation of the antifungal activity
Authors: Nasuno Tomoko , Takano Toshiyuki , Yoshimura Tsuyoshi , Kamitakahara Hiroshi , Nakatsubo Fumiaki
Published: March 2006

Acetoacetylated wood meal (AAWM) was prepared and a preliminary evaluation of its antifungal activity was carried out. Acetoacetylation of wood meal proceeded almost quantitatively with diketene under optimal reaction conditions, even as a heterogeneous reaction. Diketene concentration was the most important governing factor for this reaction. AAWM with a high weight percentage gain inhibited the fungal growth of Fomitopsis palustris.
Preparation of acetoacetylated wood meal and its properties. Part 2. Copper ion fixation by acetoacetylation
Authors: Nasuno Tomoko , Takano Toshiyuki , Kamitakahara Hiroshi , Nakatsubo Fumiaki
Published: March 2006

Fixation of copper ions to acetoacetylated wood meal (AAWM) was conducted in Cu(OAc)2-MeOH solution. The maximum amount of copper fixed to AAWM was 147.9 mg g−1 under optimum conditions. From FT-IR analyses of AAWM containing copper ions (AAWM-Cu), it was concluded that a chelate was formed between copper and the acetoacetyl group of AAWM. In a leaching test, half of the copper in AAWM-Cu was retained, even at pH 4.0.
Detection of fungal decay by high-energy multiple impact (HEMI) testing
Authors: Brischke Christian , Welzbacher Christian Robert , Rapp Andreas Otto
Published: March 2006

The suitability of a previously described high-energy multiple impact (HEMI) test for the detection of early fungal decay was examined. The HEMI test characterises the treatment severity of thermally modified wood by stressing the treated material by thousands of impacts of pounding steel balls. This method differentiates between heat treatment intensities, which are manifest as structural changes in the wood. Similar changes in wood structure are known for wood decayed by fungi. Pine (Pinus sylvestris L.) decayed by brown rot and beech (Fagus sylvatica L.) decayed by white rot were tested. Mass loss caused by fungal decay and resistance to impact milling (RIM) determined in HEMI tests were found to be highly correlated. Testing of non-degraded pine, beech, and ash (Fraxinus exelsior L.) showed only marginal effects of wood density on RIM. Furthermore, annual ring angles and RIM of spruce (Picea abies Karst.) were not correlated. Accordingly, the detection of RIM reduction in decayed wood is not masked by variations in density and orientation of the annual rings. Previous results showed no adverse effects of weathering on RIM. Thus, the detection of fungal decay with HEMI tests is feasible not only for laboratory purposes, but also for wood in outdoor applications that has already undergone weathering.
The Use of Digital Image Correlation to Verify the Behavior of Fiber Metal Laminate Cylinders under Torsional Loading
Authors: Backman D , Jodoin A , Poon C , Mendis Y
Published: March 2006

Measurements made using digital image correlation were compared to both strain gages and displacement transducers during the testing of a fiber metal laminate cylinder under torsional loading. The image correlation results showed very good agreement with measurements made using both strain gages and displacement transducers. The image correlation results were also used to measure out-of-plane displacement of the cylinder and to determine the exact onset of initial buckling. Although strain gages remain a proven and valuable technology for measuring strain, image correlation can completely characterize full-field strains and full-field displacements in the cylinder. In addition, image correlation is able to provide insight into the material behavior at strain values where the gages are less reliable and more prone to failure.
Simulation of Heat Transfer and Residual Stresses from Cooling Curves Obtained in Quenching Studies
Authors: Penha RN , Canale LCF , Totten GE , Sarmiento GS , Ventura JM
Published: March 2006

This paper describes the use of computational simulation of heat transfer and resulting residual stress obtained by quenching a standard probe into different quench oils. Cooling curves were obtained after immersing a preheated 12.-mm diameter × 60 mm cylindrical Inconel 600 (Wolfson) probe with a Type K thermocouple inserted into the geometric center into a mineral oil quenchant as described in ASTM D 6200. Four different oil quenchants were used. Three of these oils were typical commercial quench oils and one was a used quench oil from a heat treating shop. Heat transfer coefficients were estimated using HT-Mod, a recently released commercial computational code. Using the cooling curve temperature—time data, the temperature distribution within the probe and the corresponding residual stresses were calculated using ABAQUS. These results of this work illustrate potential benefits of computational simulation to examine the potential impact of different quenchants and quenching conditions on a heat treatment process.
Quantification of UV‐Induced Erythema and Pigmentation Using Computer‐Assisted Digital Image Evaluation
Authors: Coelho Sergio G. , Miller Sharon A. , Zmudzka Barbara Z. , Beer Janusz Z.
Published: March 2006

Photography has been used in human skin research for some time. With the advent of digital photography in recent years, its use has increased. However, the focus has now turned from documentation to actual analysis and quantification of skin color changes. The advantages of digital photography out‐weigh any shortcomings as long as consistent, standardized procedures are followed and quality control is implemented. We present a simple procedure to standardize images and discuss a computer‐assisted digital image evaluation (CADIE) technique to quantify skin color changes following UV exposure. The CADIE approach is illustrated with examples from two different studies on UV responses in human skin. Using the Commission Internationale de l'Eclairage L*a*b* color coordinate system in combination with a personal computer and image‐editing software, we analyzed digital images obtained in these two studies. We demonstrate the feasibility of using digital photography for objective evaluation of UV erythema in different racial/ethnic groups and for measuring pigmentation changes caused by repeated exposures over a period of several weeks. Our results indicate how objective assessment using CADIE can be an adjunct to visual and optical observation in clinical and scientific evaluations.
Discriminant Classification of Fish and Zooplankton Backscattering at 38 and 120 kHz
Authors: McKelvey Denise R. , Wilson Christopher D.
Published: March 2006

Acoustic scattering layers were evaluated for species classification by means of 38‐ and 120‐kHz mean volume backscattering strength () collected during a 1995 acoustic–trawl survey of Pacific hake Merluccius productus off the west coasts of the United States and Canada. Scattering layers selected for analyses were shallower than 150 m and were analyzed with a −79‐decibel (dB) integration threshold. Pacific hakes, euphausiids, and Pacific hake–euphausiid mixes dominated the layers. Other scatterers (unidentified, noneuphausiid, or non—Pacific hake sources) were included in the analyses. The overall mean volume backscatter difference (Δ = 120 kHz – 38 kHz) was computed for each species category, and results varied depending on the species composition of the scattering layer (i.e., Pacific hakes = −7.1 dB, euphausiids = 11.9 dB, Pacific hakes–euphausiids = 3.5 dB, and other species = 0.1 dB). Discriminant function analysis of 120 kHz and 38 kHz separated echoes originating from each of the dominant scattering layers. Backscatter was then classified into species groups with a quadratic discriminant classification model, which obtained an overall correct classification rate of 84%. The use of multiple frequencies and these analytical methods (e.g., frequency differencing and discriminant classification functions) can provide an efficient and objective means of classifying sound‐scattering layers composed of different taxonomic groups.
Estimating Mortality from Mean Length Data in Nonequilibrium Situations, with Application to the Assessment of Goosefish
Authors: Gedamke Todd , Hoenig John M.
Published: March 2006

The Beverton–Holt length‐based mortality estimator has received widespread use primarily due to its applicability in data‐limited situations. The mean length of animals that are fully vulnerable to the sampling gear can be used to estimate total mortality from basic growth parameters and a known length at first capture. This method requires equilibrium conditions because the mean length of a population will change only gradually after a change in mortality. In this study, we derive the transitional behavior of the mean length statistic for use in nonequilibrium conditions. We investigate conditions affecting the reliability of the Beverton–Holt results and then develop a new procedure that allows a series of mortality rates to be estimated from mean length data representing nonequilibrium conditions in multiple years. We then examine an assessment of goosefish Lophius americanus that was criticized for its use of the Beverton–Holt estimator under nonequilibrium conditions. Using data from the 1963–2002 National Marine Fisheries Service annual fall groundfish surveys off the northeastern United States and assuming a single change in total mortality, we used the maximum likelihood method to estimate that the total mortality of goosefish in the southern assessment region increased from 0.31 to 0.60 per year in 1977. Estimates of the new mortality rate made three or more years after the change were relatively stable and only ranged from 0.55 to 0.71 per year, while estimates from the standard Beverton–Holt approach ranged from 0.37 to 1.1 per year. The results for goosefish in the northern assessment region showed that total mortality changed from 0.14 to 0.29 per year in 1978 and then to 0.55 per year in 1987. The new nonequilibrium estimator allows a change in mortality to be characterized reliably several years faster than would occur with the use of the Beverton–Holt estimator.
1,25-dihydroxyvitamin D3 and its receptor inhibit the chenodeoxycholic acid-dependent transactivation by farnesoid X receptor
Authors: Honjo Yumiko , Sasaki Shigekazu , Kobayashi Yoshimasa , Misawa Hiroko , Nakamura Hirotoshi
Published: March 2006

Farnesoid X receptor (FXR), the receptor for bile acids, including chenodeoxycholic acid (CDCA), is a member of the nuclear receptor superfamily, which also includes the receptors for retinoic acid, vitamin D (D3), thyroid hormone, thiazolidinedione and 22(R)-hydroxycholesterol. Here, we have evaluated the effects of a series of ligands and their receptors on the promoter activity induced by CDCA/FXR. The kidney cell line, CV1, was cotransfected with FXR-expression plasmid and the luciferase-based reporter gene that has a thymidine kinase promoter fused to the canonical FXR-responsive element or the natural promoter for the small heterodimer partner (SHP), bile salt export pump (BSEP), and ileum bile acid (I-BABP) gene. D3 and its receptor (VDR) inhibited the transactivation of all four reporter constructs that are enhanced by CDCA/FXR. The effect of D3 on the expression of the BSEP and SHP genes in HepG2 cells and that of the I-BABP gene in Caco-2 cells were confirmed by reverse transcription (RT)–PCR. Deletion analysis of VDR revealed that its ligand-binding domain (LBD) is responsible for the repression and the DNA-binding domain (DBD) is dispensable. Specific interaction between FXR and VDR was detected with the in vitro pull-down assay using chimeric FXR or VDR fused to glutathione-S-transferase.