bluuebunny/crossref_metadata_2025_split huggingface dataset:
Establishment of reference range for thyroid hormones in normal pregnant Indian women
Authors: Marwaha RK , Chopra S , Gopalakrishnan S , Sharma B , Kanwar RS , Sastry A , Singh S 
Published: March 2008

Background  Interpretation of thyroid function tests during pregnancy needs trimester‐related reference intervals from pregnant populations with minimal risk for thyroid dysfunction. While India has become iodine sufficient after two decades of salt iodisation, there is no normative data for thyroid function from healthy pregnant women of this country.Aims and objectives  To determine trimester‐specific reference ranges for free triiodothyronine (FT3), free thyroxine (FT4) and thyrotropin (TSH) from healthy pregnant Indian women.Design  Cross‐sectional study in a reference population of pregnant women.Setting  Primary care level obstetric department in India.Population  Women with uncomplicated pregnancy in any trimester.Methods  Five hundred and forty‐one apparently healthy pregnant women with uncomplicated single intrauterine gestations reporting to the Armed Forces Clinic in any trimester were consecutively recruited. Clinical examination, thyroid ultrasound for echogenicity and nodularity and estimation of FT3, FT4, TSH and antithyroid antibodies (antithyroperoxidase [anti‐TPO] and antithyroglobulin [anti‐Tg]) using electrochemiluminescence technique were carried out. From this entire sample, a disease‐ and risk‐free reference population was obtained by excluding those with any known factor that could affect thyroid function or those who were being treated for thyroid dysfunction.Main outcome measure  None.Results  Of the 541 consecutive pregnant women in different trimesters enrolled for the study, 210 women were excluded. The composition of reference population comprising 331 women was 107 in first trimester, 137 in second trimester and 87 in third trimester. The 5th and 95th percentiles values were used to determine the reference ranges for FT3, FT4 and TSH. The trimester‐wise values in the first, second and third trimesters were: FT3 (1.92–5.86, 3.2–5.73 and 3.3–5.18 pM/l), FT4 (12–19.45, 9.48–19.58 and 11.32–17.7 pM/l) and TSH (0.6–5.0, 0.44–5.78 and 0.74–5.7 iu/ml), respectively. Analysis of mean, median values for FT3, FT4 and TSH between each trimester showed no significant difference in FT3 and TSH values (95% CI). However, FT4 showed significant variation between trimesters with values decreasing with advancing gestational age (P value: first versus second = 0.015, first versus third = 0.003 and second versus third = not significant). Women with antibody positivity and hypoechogenicity of thyroid gland had significantly higher TSH values when compared with women with antibody negativity and normoechogenicity.Conclusions  Reference ranges of FT3, FT4 and TSH have been established for pregnant Indian women using 5th and 95th percentiles.
Kynurenine pathway metabolism in human blood–brain–barrier cells: implications for immune tolerance & neurotoxicity
Authors: Owe‐Young Robert , Webster Nicole L. , Mukhtar Muhammad , Pomerantz Roger J. , Smythe George , Walker David , Armati Patricia J. , Crowe Suzanne M. , Brew Bruce J. 
Published: March 2008

AbstractThe catabolic pathway of l‐tryptophan (l‐trp), known as the kynurenine pathway (KP), has been implicated in the pathogenesis of a wide range of brain diseases through its ability to lead to immune tolerance and neurotoxicity. As endothelial cells (ECs) and pericytes of the blood–brain–barrier (BBB) are among the first brain‐associated cells that a blood‐borne pathogen would encounter, we sought to determine their expression of the KP. Using RT‐PCR and HPLC/GC‐MS, we show that BBB ECs and pericytes constitutively express components of the KP. BBB ECs constitutively synthesized kynurenic acid, and after immune activation, kynurenine (KYN), which is secreted basolaterally. BBB pericytes produced small amounts of picolinic acid and after immune activation, KYN. These results have significant implications for the pathogenesis of inflammatory brain diseases in general, particularly human immunodeficiency virus (HIV)‐related brain disease. Kynurenine pathway activation at the BBB results in local immune tolerance and neurotoxicity: the basolateral secretion of excess KYN can be further metabolized by perivascular macrophages and microglia with synthesis of quinolinic acid. The results point to a mechanism whereby a systemic inflammatory signal can be transduced across an intact BBB to cause local neurotoxicity.
The co‐evolution of phytoplankton and trace element cycles in the oceans
Authors: MOREL FRANÇOIS M. M. 
Published: March 2008

ABSTRACTThe composition of the oceans and of its biota have influenced each other through Earth's history. Of all the biologically essential elements, nitrogen is the only one whose seawater concentration is clearly controlled biologically; this is presumably the main reason why the stoichiometry of nitrogen (defined as its mol ratio to phosphorus), but not that of the trace nutrients manganese, iron, cobalt, nickel, copper, zinc and cadmium, is the same in seawater and in the plankton. Like the major nutrients, the trace nutrients are depleted in surface seawater as a result of quasi‐complete utilization by the biota. This is made possible in part by the ability of marine phytoplankton to replace one trace metal by another in various biochemical functions. This replacement also results in an equalization of the availability of most essential trace metals in surface seawater. The difference in the stoichiometric composition of the plankton and of deep seawater, which is the dominant source of new nutrients to the surface, indicates that some nutrients are likely recycled with different efficiencies in the photic zone. The difference in the composition of the ocean and its biota provides insight into the coupling of biochemistry and biogeochemistry in seawater.
Genetic and Environmental Influences on the Rate of Progression to Alcohol Dependence in Young Women
Authors: Sartor Carolyn E. , Agrawal Arpana , Lynskey Michael T. , Bucholz Kathleen K. , Heath Andrew C. 
Published: March 2008

Background:  The development of alcohol dependence (AD) involves transitions through multiple stages of drinking behaviors and is shaped by both heritable and environmental influences. We attempted to capture this dynamic process by characterizing genetic and environmental contributions to the rate at which women progressed through 3 significant transitions along the pathway to AD: nonuse to initiation, initiation to onset of first alcohol‐related problem, and first problem to onset of AD.Methods:  The sample consisted of 3,546 female twins from the Missouri Adolescent Female Twin Study. Participants ranged in age from 18 to 29 years. Retrospective reports of alcohol use histories were collected by telephone diagnostic interview and transition times between drinking milestones were coded ordinally. Standard genetic analyses were conducted in Mx to derive a trivariate model that provided estimates of genetic and environmental influences that were common as well as specific to the 3 transition times.Results:  Heritable influences were found for rate of progression across all 3 transitions, accounting for 30 to 47% of the variance in transition times. Shared environmental contributions were evident only in rate of progression from nonuse to initiation (i.e., age at first drink). Heritable contributions to the rate of movement through successive drinking milestones were attributable to a common factor, whereas environmental influences were transition‐specific.Conclusions:  The current study is unique in its use of a genetically informative design to document the rate of movement between drinking milestones in a female sample and to examine genetic contributions to multiple transition times over the course of AD development. Results indicate that an earlier report of heritability for males in rate of progression from regular drinking to AD generalizes to women and to other alcohol stage transitions. Findings also suggest the need to consider stage‐specific environmental contributions to alcohol outcomes in developing interventions.
Association of ADH and ALDH Genes With Alcohol Dependence in the Irish Affected Sib Pair Study of Alcohol Dependence (IASPSAD) Sample
Authors: Kuo Po‐Hsiu , Kalsi Gursharan , Prescott Carol A. , Hodgkinson Colin A. , Goldman David , Van Den Oord Edwin J. , Alexander Jeffry , Jiang Cizhong , Sullivan Patrick F. , Patterson Diana G. , Walsh Dermot , Kendler Kenneth S. , Riley Brien P. 
Published: March 2008

Background:  The genes coding for ethanol metabolism enzymes [alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH)] have been widely studied for their influence on the risk to develop alcohol dependence (AD). However, the relation between polymorphisms of these metabolism genes and AD in Caucasian subjects has not been clearly established. The present study examined evidence for the association of alcohol metabolism genes with AD in the Irish Affected Sib Pair Study of alcohol dependence.Methods:  We conducted a case–control association study with 575 independent subjects who met Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, AD diagnosis and 530 controls. A total of 77 single nucleotide polymorphisms (SNPs) in the seven ADH (ADH1‐7) and two ALDH genes (ALDH1A1 and ALDH2) were genotyped using the Illumina GoldenGate protocols. Several statistical procedures were implemented to control for false discoveries.Results:  All markers with minor allele frequency greater than 0.01 were in Hardy–Weinberg equilibrium. Numerous SNPs in ADH genes showed association with AD, including one marker in the coding region of ADH1C (rs1693482 in exon6, Ile271Gln). Haplotypic association was observed in the ADH5 and ADH1C genes, and in a long haplotype block formed by the ADH1A and ADH1B loci. We detected two significant interactions between pairs of markers in intron 6 of ADH6 and intron 12 of ALDH2 (p = 5 × 10−5), and 5′ of both ADH4 and ADH1A (p = 2 × 10−4).Conclusion:  We found evidence for the association of several ADH genes with AD in a sample of Western European origin. The significant interaction effects between markers in ADH and ALDH genes suggest possible epistatic roles between alcohol metabolic enzymes in the risk for AD.
Liver dysfunction after chemotherapy in lymphoma patients infected with hepatitis C
Authors: Dizdar Omer , Tapan Umit , Aksoy Sercan , Harputluoglu Hakan , Kilickap Saadettin , Barista Ibrahim 
Published: March 2008

AbstractReactivation of hepatitis B virus (HBV) infection in asymptomatic hepatitis B surface antigen carriers undergoing chemotherapy or immunosuppressive therapy is a well‐documented complication. However, data on the consequence of chemotherapy on the course of hepatitis C virus (HCV) infection in HCV(+) patients have been controversial. Here, we review the current knowledge about the complications related to HCV in lymphoma patients receiving chemotherapy/immunosuppressive therapy. Although less frequent than HBV, these complications occur in a subset of patients with mortality rates up to 45%. Therefore, baseline screening for HBV and HCV before initiation of chemotherapy is crucial. High‐risk patients having chronic active hepatitis, high baseline HCV viral load, HBV co‐infection and receiving cytotoxic drugs, corticosteroids and rituximab (particularly if combined) should be closely monitored for serum transaminase, bilirubin and HCV RNA levels.
Neonatal testicular torsion – a lost cause?
Authors: Mathews John Cheri , Kooner Gagan , Mathew Deepa E , Ahmed Shiban , Kenny Simon E 
Published: March 2008

AbstractTwenty‐four neonates presented with signs of testicular ischaemia over a 13‐year period. They had a mean birth weight of 3.706 kg. The right testicle was affected in 13, the left in 9 and there was bilateral torsion in 2 babies. Two babies had no twist in the cord, but the testicles were nonviable macroscopically and microscopically. Twenty‐one babies had primary exploration revealing necrotic testes in all patients and they underwent orchidectomies. The other three babies had conservative management and the affected testes had atrophied on follow‐up. Sixteen babies had contralateral orchidopexy. Doppler ultrasound scans were reported as normal in 2 of 13 babies who had scans. No testes were salvaged following surgery.Conclusion: The incidence of testicular torsion in the neonatal period was calculated as 6.1 per 100 000 live births. No testis was salvaged following surgery in our series of 24 patients. This dismal outcome underlines that immediate surgical exploration, although commonly performed, rarely saves torted testes.
Tracing Ground Water Input to Base Flow Using Sulfate (S, O) Isotopes
Authors: Gu Ailiang , Gray Floyd , Eastoe Christopher J. , Norman Laura M. , Duarte Oscar , Long Austin 
Published: March 2008

AbstractSulfate (S and O) isotopes used in conjunction with sulfate concentration provide a tracer for ground water contributions to base flow. They are particularly useful in areas where rock sources of contrasting S isotope character are juxtaposed, where water chemistry or H and O isotopes fail to distinguish water sources, and in arid areas where rain water contributions to base flow are minimal. Sonoita Creek basin in southern Arizona, where evaporite and igneous sources of sulfur are commonly juxtaposed, serves as an example. Base flow in Sonoita Creek is a mixture of three ground water sources: A, basin ground water with sulfate resembling that from Permian evaporite; B, ground water from the Patagonia Mountains; and C, ground water associated with Temporal Gulch. B and C contain sulfate like that of acid rock drainage in the region but differ in sulfate content. Source A contributes 50% to 70%, with the remainder equally divided between B and C during the base flow seasons. The proportion of B generally increases downstream. The proportion of A is greatest under drought conditions.
Quantum Mechanical/Molecular Mechanical Studies on Spectral Tuning Mechanisms of Visual Pigments and Other Photoactive Proteins†
Authors: Altun Ahmet , Yokoyama Shozo , Morokuma Keiji 
Published: March 2008

AbstractThe protein environments surrounding the retinal tune electronic absorption maximum from 350 to 630 nm. Hybrid quantum mechanical/molecular mechanical (QM/MM) methods can be used in calculating excitation energies of retinal in its native protein environments and in studying the molecular basis of spectral tuning. We hereby review recent QM/MM results on the phototransduction of bovine rhodopsin, bacteriorhodopsin, sensory rhodopsin II, nonretinal photoactive yellow protein and their mutants.
Melanosomal Damage in Normal Human Melanocytes Induced by UVB and Metal Uptake—A Basis for the Pro‐oxidant State of Melanoma†
Authors: Gidanian Shirley , Mentelle Mallory , Meyskens Frank L. , Farmer Patrick J. 
Published: March 2008

AbstractMelanins are ubiquitous catecholic pigments, formed in organelles called melanosomes within melanocytes, the function of which is to protect skin against harmful effects of UV radiation. Melanosomes within melanoma cells are characteristically abnormal, with fragmented melanin and disrupted membranes. We hypothesize that the disruption of melanosomal melanin might be an early event in the etiology and progression of melanoma, leading to increased oxidative stress and mutation. In this report, we examine the effect of a combination of UV treatment and metal ion exposure on melanosomes within melanocytes, as well as their ability to act as pro‐oxidants in ex situ experiments, and assay the effects of this treatment on viability and cell cycle progression. UVB exposure causes morphologic changes of the cells and bleaching of melanosomes in normal melanocytes, both significantly enhanced in Cu(II) and Cd(II)‐treated cells, as observed by microscopy. The promoted bleaching by Cu(II) is due to its ability to redox cycle under oxidative conditions, generating reactive oxygen species; verified by the observed enhancement of hydroxyl radical generation when isolated melanosomes were treated with both Cu(II) ions and UVB, as assayed by DNA clipping. Single‐dose UVB/Cu treatment does not greatly affect cell viability or cell cycle progression in heavily pigmented cells, but did so in an amelanotic early stage melanoma cell line.
Salamander Blue‐sensitive Cones Lost During Metamorphosis†
Authors: Chen Ying , Znoiko Sergey , DeGrip Willem J. , Crouch Rosalie K. , Ma Jian‐xing 
Published: March 2008

AbstractThe tiger salamander lives in shallow water with bright light in the aquatic phase, and in dim tunnels or caves in the terrestrial phase. In the aquatic phase, there are five types of photoreceptors—two types of rods and three types of cones. Our previous studies showed that the green rods and blue‐sensitive cones contain the same visual pigment and have the same absorbance spectra; however, the green rods have a larger photon‐catch area and thus have higher light sensitivity than the blue‐sensitive cones. Here we show that after metamorphosis, the terrestrial salamander looses the blue‐sensitive cones, while the density of the green rods increases. Moreover, the size of the green rod outer segments is increased in the terrestrial phase, compared to that in the aquatic phase. This switch from the blue‐sensitive cones to the green rods may represent an adaptation to the dim light environment of the terrestrial phase.
Oxygen Dependence of Two‐photon Activation of Zinc and Copper Phthalocyanine Tetrasulfonate in Jurkat Cells
Authors: Mir Youssef , Van Lier Johan E. , Paquette Benoit , Houde Daniel 
Published: March 2008

AbstractPhotodynamic therapy (PDT), the use of light‐activated drugs, is a promising treatment of cancer as well as several nonmalignant conditions. However, the efficacy of one‐photon (1‐γ) PDT is limited by hypoxia, which can prevent the production of the cytotoxic singlet oxygen (1O2) species, leading to tumor resistance to PDT. To solve this problem, we propose an irradiation protocol based on a simultaneous, two‐photon (2‐γ) excitation of the photosensitizer (Ps). Excitation of the Ps triplet state leads to an upper excited triplet state Tn with distinct photochemical properties, which could inflict biologic damage independent of the presence of molecular oxygen. To determine the potential of a 2‐γ excitation process, Jurkat cells were incubated with zinc or copper phthalocyanine tetrasulfonate (ZnPcS4 or CuPcS4). ZnPcS4 is a potent 1O2 generator in 1‐γ PDT, while CuPcS4 is inactive under these conditions. Jurkat cells incubated with either ZnPcS4 or CuPcS4 were exposed to a 670 nm continuous laser (1‐γ PDT), 532 nm pulsed‐laser light (2‐γ PDT), or a combination of 532 and 670 nm (2‐γ PDT). The efficacy of ZnPcS4 to photoinactivate the Jurkat cells decreased as the concentration of oxygen decreased for both the 1‐γ and 2‐γ protocols. In the case of CuPcS4, cell phototoxicity was measured only following 2‐γ irradiation, and its efficacy also decreased at a lower oxygen concentration. Our results suggest that for CuPcS4 the Tn excited state can be populated after 2‐γ irradiation at 532 nm or the combination of 532 and 670 nm light. Dependency of phototoxicity upon aerobic conditions for both 1‐γ and 2‐γ PDT suggests that reactive oxygen species play an important role in 1‐γ and 2‐γ PDT.
The Length of Esterifying Alcohol Affects the Aggregation Properties of Chlorosomal Bacteriochlorophylls
Authors: Zupcanova Anita , Arellano Juan B. , Bina David , Kopecky Jiri , Psencik Jakub , Vacha Frantisek 
Published: March 2008

AbstractChlorosomes, the main light‐harvesting complexes of green photosynthetic bacteria, contain bacteriochlorophyll (BChl) molecules in the form of self‐assembling aggregates. To study the role of esterifying alcohols in BChl aggregation we have prepared a series of bacteriochlorophyllide c (BChlide c) derivatives differing in the length of the esterifying alcohol (C1, C4, C8 and C12). Their aggregation behavior was studied both in polar (aqueous buffer) and nonpolar (hexane) environments and the esterifying alcohols were found to play an essential role. In aqueous buffer, hydrophobic interactions among esterifying alcohols drive BChlide c derivatives with longer chains into the formation of dimers, while this interaction is weak for BChlides with shorter esterifying alcohols and they remain mainly as monomers. All studied BChlide c derivatives form aggregates in hexane, but the process slows down with longer esterifying alcohols due to competing hydrophobic interactions with hexane molecules. In addition, the effect of the length of the solvent molecules (n‐alkanes) was explored for BChl c aggregation. With an increasing length of n‐alkane molecules, the hydrophobic interaction with the farnesyl chain becomes stronger, leading to a slower aggregation rate. The results show that the hydrophobic interaction is the driving force for the aggregation in an aqueous environment, while in nonpolar solvents it is the hydrophilic interaction.
Aristotle and Earthquake Data: A Historical Note
Authors: Missiakoulis Spyros 
Published: March 2008

Summary The earliest known written work on earthquake theory was written by Aristotle (c. 330 B.C.). Aristotle had collected a lot of earthquake data and therefore we assume (or rather speculate) he had to organize, to classify and to summarize them in order to use and describe them in his work. With respect to the history of Statistics, the Aristotelian text on earthquake theory is probably the earliest written application of statistical tables on collected data.
Dental Health Services Utilization and Associated Factors in Children 6 to 12 Years Old in a Low‐Income Country
Authors: Medina‐Solis Carlo Eduardo , Maupomé Gerardo , Del Socorro Herrera Miriam , Pérez‐Núñez Ricardo , Ávila‐Burgos Leticia , Lamadrid‐Figueroa Hector 
Published: March 2008

AbstractObjective: To determine the factors associated with the dental health services utilization among children ages 6 to 12 in León, Nicaragua.Material and Methods: A cross‐sectional study was carried out in 1,400 schoolchildren. Using a questionnaire, we determined information related to utilization and independent variables in the previous year. Oral health needs were established by means of a dental examination. To identify the independent variables associated with dental health services utilization, two types of multivariate regression models were used, according to the measurement scale of the outcome variable: a) frequency of utilization as (0) none, (1) one, and (2) two or more, analyzed with the ordered logistic regression and b) the type of service utilized as (0) none, (1) preventive services, (2) curative services, and (3) both services, analyzed with the multinomial logistic regression.Results: The proportion of children who received at least one dental service in the 12 months prior to the study was 27.7 percent. The variables associated with utilization in the two models were older age, female sex, more frequent toothbrushing, positive attitude of the mother toward the child's oral health, higher socioeconomic level, and higher oral health needs.Conclusion: Various predisposing, enabling, and oral health needs variables were associated with higher dental health services utilization. As in prior reports elsewhere, these results from Nicaragua confirmed that utilization inequalities exist between socioeconomic groups. The multinomial logistic regression model evidenced the association of different variables depending on the type of service used.