julilili42/papers huggingface dataset:
Cellular responses and cytokine profiles in Ascaris lumbricoides and Trichuris trichiura infected patients
2002-11-01

SUMMARY The impact of intestinal helminth infection, i.e. Ascaris lumbricoides and Trichuris trichiura , on cellular responsiveness and cytokine production was investigated in young adults. Ascaris ‐specific cellular responsiveness was higher in parasite‐free endemic controls than in patients infected with T. trichiura , or A. lumbricoides, or patients co‐infected with both parasites. Also, mitogen‐induced tumour necrosis factor (TNF)‐α, interleukin (IL)‐12 and interferon (IFN)‐γ secretion by peripheral blood mononuclear cells (PBMC) was higher in negative endemic controls than in infected individuals. Ascaris antigen‐specific production of TNF‐α, IL‐12 and IFN‐γ was low in singly Ascaris as well as in co‐infected patients, whereas secretion of IL‐10 and IL‐13 was elevated and similarly high in all patient groups. The detection of Trichuris ‐specific and Ascaris ‐specific IgG4 revealed significantly higher serum antibody levels in Trichuris or Ascaris patients when compared to endemic controls ( P &lt; 0·05), whereas parasite‐specific IgE antibody levels were similarly high in infected individuals and in endemic controls. In summary, chronically infected Ascaris and Trichuris patients with a high parasite load presented reduced cellular reactivity and lower type 1 TNF‐α, IFN‐γ and IL‐12 responses when compared with endemic controls, whereas type 2 IL‐10 and IL‐13 productions were similar in all groups from the endemic area. The former may support parasite persistence, whereas substantial type 2 cytokine release may promote protective immunity, suggesting an adaptation of the host to control the parasite burden while minimizing immune‐mediated host self‐damage.
Efficacy of Metoprolol and Sotalol in the Prevention of Recurrences of Sustained Ventricular Tachyarrhythmias in Patients with an Implantable Cardioverter Defibrillator
2002-11-01

KETTERING, K., et al. : Efficacy of Metoprolol and Sotalol in the Prevention of Recurrences of Sustained Ventricular Tachyarrhythmias in Patients with an Implantable Cardioverter Defibrillator. ICDs provide protection against sudden cardiac death in patients with life‐threatening ventricular arrhythmias. Nevertheless, most ICD recipients receive adjunctive antiarrhythmic drug therapy to reduce the number of recurrent episodes and ICD discharges. The aim of the study was to compare the efficacy of metoprolol and d,l‐sotalol in preventing VT/VF recurrences in patients with an ICD in a prospective, randomized trial. One hundred patients (83 men, 17 women; mean age 59 years, SD ± 11 years) were randomized to receive metoprolol or sotalol after implantation of an ICD. There were no significant differences between the two groups with regard to age, sex, underlying cardiac disease, left ventricular ejection fraction, NYHA class assessment and clinical arrhythmia. The median follow‐up was 728 days (25th percentile: 530 days, 75th percentile: 943 days) in the metoprolol group and 727 days (25th percentile: 472 days, 75th percentile: 1,223 days) in the sotalol group ( P = 0.52 ). Thirty‐three patients treated with metoprolol and 30 patients receiving sotalol had at least one episode during the follow‐up. Event‐free survival curves were generated for the two treatment arms using the Kaplan‐Meier method and showed no significant difference ( P = 0.68 ). Eight patients treated with metoprolol and six patients treated with sotalol died during follow‐up. Total mortality was not significantly different between the two study groups ( P = 0.43 ). Metoprolol is as efficacious as sotalol in preventing VT/VF recurrences in patients with an ICD.
Complex sociogenetic organization and reproductive skew in a primitively eusocial sweat bee,Lasioglossum malachurum, as revealed by microsatellites
2002-11-01

Abstract The sweat bees (Family Halictidae) are a socially diverse taxon in which eusociality has arisen independently numerous times. The obligate, primitively eusocial Lasioglossum malachurum , distributed widely throughout Europe, has been considered the zenith of sociality within halictids. A single queen heads a colony of smaller daughter workers which, by mid‐summer, produce new sexuals (males and gynes), of which only the mated gynes overwinter to found new colonies the following spring. We excavated successfully 18 nests during the worker‐ and gyne‐producing phases of the colony cycle and analysed each nest's queen and either all workers or all gynes using highly variable microsatellite loci developed specifically for this species. Three important points arise from our analyses. First, queens are facultatively polyandrous (queen effective mating frequency: range 1–3, harmonic mean 1.13). Second, queens may head colonies containing unrelated individuals ( n = 6 of 18 nests), most probably a consequence of colony usurpation during the early phase of the colony cycle before worker emergence. Third, nonqueen's workers may, but the queen's own workers do not, lay fertilized eggs in the presence of the queen that successfully develop into gynes, in agreement with so‐called ‘concession’ models of reproductive skew.
Homozygous mutation within the conserved Ala-Phe-Asn-Glu-Thr motif of exon 7 of the LH receptor causes male pseudohermaphroditism
2002-11-01

BACKGROUND: Human chorionic gonadotropin/luteinizing hormone (hCG/LH) function in the male is mediated by the LH receptor (LHR) and is crucial for the normal development of internal and external genitalia. We report a 46, XY patient who presented at the age of 16 with a female phenotype and delayed puberty. Gonads were located bilaterally in the inguinal canal, removed surgically and showed hypoplastic Leydig cells. Immunostaining for the LHR revealed that some Leydig cell progenitors were positive, while others were negative, reflecting different developmental stages of Leydig cell maturation. METHODS AND RESULTS: Molecular analysis of the LHR was performed on DNA extracted from blood samples of the patient, her parents and sister. The 11 exons of the LHR gene were amplified by PCR and subjected to further single stranded conformation polymorphism (SSCP) analysis. Aberrant migration patterns were observed in exon 7. Upon sequencing, a homozygous T to G transversion was identified, resulting in a F194V substitution located in the extracellular domain. The parents and sister were heterozygous carriers of this mutation. Functional studies in transiently transfected COS-7 cells with the F194V LHR mutation showed the lack of cAMP production upon hCG stimulation, indicating complete inactivation of the receptor due to impaired trafficking of the receptor to the membrane. The mutation is located within a stretch of five amino acids Ala (A)-Phe (F)-Asn (N)-Gly (G)-Thr (T), highly conserved in glycoprotein hormone receptors. For the follicle-stimulating hormone (FSH) receptor (FSHR) loss-of-function mutations have been allocated to this region, a homozygous A189V mutation resulting in a resistant ovary syndrome and impaired spermatogenesis and a heterozygous N191I mutation with no apparent phenotype. Further mutational and functional analysis of the AFN region in the LHR and FSHR revealed that the integrity of this amino acid sequence is crucial for receptor function.
Replicative aging of human articular chondrocytes during ex vivo expansion
2002-11-01

Abstract Objective To investigate the contribution of clinical ex vivo expansion protocols to replicative aging of human chondrocytes. Methods Primary human chondrocytes were cultured as monolayers after isolation from 7 articular cartilage specimens. Cells were passaged corresponding to 12–19 cell population doublings (cpd). Aliquots of the cells were collected from each passage and analyzed for telomere length and telomerase activity. Results The rate of telomere shortening was heterogeneous, ranging from 147 to 431 bp/cpd (mean ± SD 305 ± 122). Telomerase activity was detected at various time points during passaging in 5 of 7 primary chondrocytes analyzed, but not in native human articular cartilage specimens. According to our data, an 8–10‐fold (∼3 cpd) ex vivo expansion of articular chondrocytes, as typically performed for transplantation procedures, leads to telomere erosion in the range of 900 bp. This is comparable with 30 years of aging based on the in vivo rate of telomere shortening of 30 bp/year recently found in chondrocytes. Conclusion If telomere shortening is an important determinant of aging in human articular cartilage, an additional telomere loss due to ex vivo expansion might affect the incidence or time of onset of age‐related cartilage disorders. However, given the limited extent of expansion performed in the clinical setting to date, a significant telomere‐mediated increase in the risk of malignant transformation or replicative exhaustion of the transplanted cells seems unlikely.
Colocalization of the apical Cl−/HCO 3 − exchanger PAT1 and gastric H-K-ATPase in stomach parietal cells
2002-11-01

The apical Cl − /HCO[Formula: see text] exchanger called the putative anion transporter (PAT1; SLC26A6) is expressed on apical membranes of villus cells in the duodenum, but its location in the stomach remains unknown. Here we examined the cell distribution and membrane location of PAT1 in mouse stomach. Immunofluorescence labeling studies with anti-PAT1 antibodies and Dolichos biflorusagglutinin indicated the exclusive expression of PAT1 in gastric parietal cells. Double immunocytochemical staining revealed colocalization of PAT1 with the gastric H-K-ATPase, consistent with expression in tubulovesicles and/or the secretory canaliculus. Radiolabeled 36 Cl flux studies demonstrated the functional presence of Cl − /HCO[Formula: see text] exchange in purified tubulovesicles of parietal cells. The expression of PAT1 was significantly decreased in parietal cells of gastric H-K-ATPase-null mice, which exhibit a sharp reduction in tubulovesicle membranes. These data indicate that the Cl − /HCO[Formula: see text]exchanger PAT1 is localized on tubulovesicular membranes, and they are consistent with the hypothesis that it functions in the maintenance of intravesicular ion concentrations in the resting state and dehydration of vesicles derived from the secretory membranes following the transition from the stimulated to the resting state.
Relationship between Serum Adiponectin Concentration and Intramyocellular Lipid Stores in Humans
2002-11-01

The recently identified adipocytokine adiponectin has been shown to improve insulin action and decrease triglyceride content in skeletal muscle (by stimulating lipid oxidation) in mice. In the present study, we tested the hypothesis that high serum concentrations of adiponectin are associated with lower intramyocellular (IMCL) fat content by promoting lipid oxidation in humans. IMCL-content in predominantly non-oxidative tibialis anterior muscle and oxidative soleus was determined by proton magnetic resonance spectroscopy in a cross- sectional study involving 63 healthy volunteers. In a second set of experiments, changes in IMCL in both muscles were measured after a three days dietary lipid challenge (n = 18) and after intravenous lipid challenge (n = 12) with suppressed lipid oxidation under hyperinsulinemia. Adiponectin serum concentrations were found to be negatively correlated with IMCL in the oxidative soleus muscle (IMCL [sol]) (r = - 0.46, p < 0.001) independent of measures of obesity, but not with IMCL in the non-oxidative tibialis anterior muscle (IMCL [tib]) (p = 0.40). Adiponectin serum concentrations were negatively correlated with the observed increase in IMCL load after dietary lipid challenge in the tibialis (r = 0.53, p = 0.03) but not in the soleus muscle. During suppression of lipid oxidation by hyperinsulinemia, no effect of adiponectin on IMCL was observed in either soleus or tibialis muscle. Overall, the presented findings are consistent with the hypothesis that adiponectin promotes lipid oxidation in humans resulting in lower intracellular lipid content in human muscle. These results are consistent with animal data, where adiponectin could be shown to enhance lipid oxidation and reduce muscle triglycerides.
Reassessment of the resistance of Plasmodium falciparum to chloroquine in Gabon: implications for the validity of tests in vitro vs. in vivo
2002-11-01

Increasing resistance of Plasmodium falciparum to antimalarial drugs presents a major risk factor for people living in endemic areas of tropical Africa. In Lambaréné, Gabon, regular surveillance of chloroquine sensitivity of P. falciparum in vitro has been carried out since 1992 using the WHO standard microtest. Results indicated that from 1994 onwards chloroquine resistance in vitro decreased significantly and that by 2000, about 70% of parasite isolates seemed to be sensitive to chloroquine in vitro. In 2001, we conducted a clinical study to reassess the efficacy of chloroquine in vivo for the treatment of uncomplicated P. falciparum malaria. Twenty-six patients aged 4-15 years were included in this study. Most unexpectedly, the study demonstrated high-grade resistance to chloroquine in vivo (failure rate on day 28 of 100%). As a consequence, tests of parasite susceptibility to chloroquine in vitro were repeated using the same protocol except for the replacement of previously used commercially available predosed WHO culture plates by independently dosed plates. All tested P. falciparum isolates were highly resistant to chloroquine, correlating well with our clinical findings. We concluded that high level resistance of P. falciparum to chloroquine persists in the study area. Neglect or absence of quality controls of essential test material can lead to invalid study results and wrong conclusions and should always be suspected in the case of major fluctuations in the sensitivity patterns of an antimalarial drug in vitro. In addition, our results highlight the supreme value of tests in vivo in providing reliable estimates of the efficacy of an antimalarial in a specific area.
Acute Effect of Glimepiride on Insulin-Stimulated Glucose Metabolism in Glucose-Tolerant Insulin-Resistant Offspring of Patients With Type 2 Diabetes
2002-11-01

OBJECTIVE—This study addressed whether acute infusion of glimepiride influences glucose metabolism independent of its effect on insulin secretion. RESEARCH DESIGN AND METHODS—Ten healthy, glucose-tolerant but insulin-resistant probands were subjected to a placebo-controlled, double-blind, cross-over study. Each individual received infusions of either 0.15 mol/l saline or glimepiride in randomized order on two separate occasions. A three-step hyperinsulinemic (0.5, 1.0, and 1.5 mU · kg−1 · min−1)-euglycemic glucose clamp was performed on both occasions to determine insulin sensitivity. Glimepiride-induced insulin secretion was inhibited by octreotide. Endogenous glucose production and glucose elimination were measured with the “hot” glucose infusion method using U-[13C]glucose as tracer. Glucose oxidation was determined from indirect calorimetry. Lipolysis was evaluated by measurements of nonesterified fatty acid (NEFA) and glycerol concentration and measurement of glycerol production. RESULTS—Plasma glucose and insulin concentrations were not significantly different between glimepiride or saline infusions. There was a significant increase in the rate of glucose infusion necessary to maintain euglycemia during infusion of glimepiride during the low- (12.2 ± 1.1 vs. 16.1 ± 1.7 μmol · kg−1· min−1) and intermediate-dose insulin infusion (24.4 ± 1.7 vs. 30.0 ± 2.8 μmol · kg−1 · min−1). This was explained by an increased rate of glucose elimination and to a lesser degree by a decrease in glucose production. Glucose oxidation rate was not different. NEFA and glycerol concentration and glycerol production were equally suppressed. CONCLUSIONS—Glimepiride improves peripheral glucose uptake and decreases endogenous glucose production independent of its insulin secretagogue action. The effects shown in this acute study are, however, too small to be considered therapeutically beneficial for the individual patient.
TonB of Escherichia coli activates FhuA through interaction with the β-barrel a aThe GenBank accession number for the sequence reported in this paper is Y15319.
2002-11-01

FhuA is a multifunctional protein in the outer membrane of Escherichia coli that actively transports Fe(3+)-ferrichrome and the antibiotics albomycin and rifamycin CGP 4832, and serves as a receptor for the unrelated phages T5, T1, phi80 and UC-1, colicin M and microcin J25. The energy source for active transport is the proton-motive force of the cytoplasmic membrane, which is required for all FhuA functions except infection by phage T5, and is thought to be mediated to the outer-membrane receptor FhuA by the TonB protein. The crystal structure of FhuA consists of a beta-barrel that is closed by a globular domain. The proximal region carries the TonB box (residues 7-11), for which genetic evidence exists that it interacts with the region around residue 160 of TonB. However, deletion of the TonB box along with the globular domain results in a protein, FhuAdelta5-160, that still displays TonB-dependent active ferrichrome transport across the outer membrane and confers sensitivity to the FhuA ligands. In this study synthetic nonapeptides identical in sequence to amino acids 150-158, 151-159, 152-160, 153-161 and 158-166 of TonB were shown to reduce ferrichrome transport of cells via wild-type FhuA and the corkless derivative FhuAdelta5-160, which suggests that this TonB region is involved in the interaction of TonB with the beta-barrel of FhuA. TonB missense mutants reduced the activity of FhuA and FhuAdelta5-160. TonB proteins of different Enterobacteriaceae activated FhuA and FhuAdelta5-160 to a similar degree. TonB of Pantoea agglomerans displayed low activity in an E. coli tonB mutant. Sequencing of the tonB gene of P. agglomerans revealed differences from E. coli TonB in the region around residue 160 of the deduced protein; these differences might contribute to the lower activity of the P. agglomerans TonB protein when coupled to the E. coli FhuA protein. The data support the theory that the beta-barrel receives the energy from the cytoplasmic membrane via TonB and responds to the energy input and thus represents the transporting domain of FhuA.
A study of gyroremanent magnetisation (GRM) and rotational remanent magnetisation (RRM) carried by greigite from lake sediments
2002-11-01

SUMMARY Further studies of gyroremanent magnetisation (GRM) and rotational remanent magnetisation (RRM) have been conducted on lake sediments from the Zoige Basin in the Eastern Tibetan Plateau, in which greigite is the main carrier of gyroremanent magnetisation. Greigite has the greatest effective gyrofield (Bg) of all magnetic minerals studied so far, being several hundred μT for a peak AF of 80 mT. This high Bg value has the potential to be used as an indicator for greigite. The GRM produced during static alternating field (AF) demagnetisation became close to its maximum at a peak AF of 150 mT. Attempts to extract the natural remanent magnetisation (NRM) by algebraic elimination of the GRM were unsuccessful above fields of about 30 mT because the GRM became much larger than the remaining NRM. The GRM of a crushed sample was much reduced because of the destruction of the sample's anisotropy, although as expected, both RRM and Bg were similar before and after crushing, thus demonstrating that RRM and Bg are independent of anisotropy. Measurement of the anisotropy of two samples from different depths showed that the deeper sample, which acquired the higher GRM, also had the higher anisotropy presumably as a result of greater sediment compaction. Study of anisotropy of GRM may help to elucidate the preferred alignment of greigite within the sample, which is difficult to ascertain by other means.
The influence of bulk composition on the diffusivity of carbon dioxide in Na aluminosilicate melts
2002-11-01

The bulk diffusivity of dissolved carbon dioxide (CO2 and CO32-) in NaAlSi3O8 + nNa2O (n = 0- 6.87 wt%) and in NaAlSi3O8 + nH2O (n = 0-2 wt%) melts was investigated at 1523 K and 0.5 GPa using the diffusion couple technique. CO2 contents of the starting glass pairs varied between 0 and 0.2 wt%. Symmetrical concentration-distance profiles of bulk CO2 were determined by infrared spectroscopy. An error function was fitted to the profiles to obtain apparent chemical diffusion coefficients of bulk CO2. In the investigated compositional range, the diffusivity of bulk CO2 increases exponentially with Na2O and H2O content and thus exponentially with the ratio of nonbridging oxygen atoms per tetrahedral cations (NBO/ T). The bulk CO2 diffusivity increases from logDCO2 = -11.38 (DCO2 in m2/s) in NaAlSi3O8 melt to logDCO2 = -10.92 in NaAlSi3O8 melts containing 6.87 wt% Na2O excess, and to logDCO2 = -10.91 in NaAlSi3O8 melts containing 2 wt% H2O. These data imply that either: (1) the diffusivities of the CO2 species (molecular CO2 and CO32-) are very similar, or (2) the speciation of CO2 in the quenched glasses is very different from the speciation in the melt.
Evaluation of calixarene—derivatives as high-resolution negative tone electron-beam resists
2002-11-01

We present a systematic evaluation of calixarene derivatives as high-resolution negative tone resists for electron-beam lithography with a focus on their sensitivities. We studied the effect of a modification of the calixarene molecules to trimethysilyl ethers as well as the effect of an introduction of an allyl group and showed that the introduction of double bonds into the molecules can improve the sensitivity of the resists while their position does not seem to be important. The high-resolution capability of tetraallylcalix[4]arene was confirmed by fabricating an 18 nm dot array.
Primary intraosseous meningioma in a skull of the medieval period of Southwestern Germany
2002-11-01

Abstract Primary intraosseous calvarial meningiomas are very rare entities in recent times. We present the first case in antiquity of a primary intraosseous meningioma in the frontoparietal bone associated with the coronal suture, and discuss its pathology. The skull derives from southwestern Germany and is dated to the 12th–14th centuries AD. The lesion is interpreted as a solitary osteoblastic neoplasm with hyperostosis on the outside, and osteolysis and radial spiculation in the central part of the lesion with an area of irregularity along the inner table. In cases of solitary osteoblastic skull lesions the differential diagnosis comprises: fibrous dysplasia, osteoma, osteoblastic metastasis, Pagets disease and meningioma with sheet‐like growth along the dural surface with marked hyperostosis (called meningioma en plaque). We believe that a differentiation between hyperostotic meningioma en plaque and intraosseous meningioma cannot be made in skulls from antiquity. Copyright © 2002 John Wiley &amp; Sons, Ltd.
Characterisation of thekatAgene encoding a catalase and evidence for at least a second catalase activity inStaphylococcus xylosus, bacteria used in food fermentation
2002-11-01

The catalase gene katA of Staphylococcus xylosus was cloned. It encodes a protein of 494 amino acids with a molecular mass of 56.9 kDa, closely related to monofunctional catalases. A katA mutant still showed a relatively high catalase activity demonstrating that S. xylosus possesses more than one enzyme. By Southern blot analysis using a katA probe, a second genetic locus distinct from katA was detected that probably contained the additional catalase gene. To analyse katA expression, a transcriptional fusion of the katA promoter region to a promoterless β-galactosidase gene was integrated into the genome of S. xylosus. katA expression is induced upon entry into stationary phase, by oxygen and hydrogen peroxide. Iron and manganese depletion induced katA transcription. Comparing the resistance of S. xylosus wild-type and the katA mutant strain to hydrogen peroxide clearly showed that KatA is essential for S. xylosus to cope with hydrogen peroxide stress. Therefore, S. xylosus has at least two differentially expressed catalases.