bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hormone replacement therapy and breast cancer risk in Kyushu University Hospital: Supporting the Women's Health Initiative study
Authors: Nozaki Masahiro , Koera Keiko , Nagata Hideaki , Nakano Hitoo 
Published: July 2004

AbstractAim:  The influence of hormone replacement therapy (HRT) on breast cancer has not been clarified in Japan, however the Women's Health Initiative (WHI) trial recently showed breast cancer risk according to use of estrogen plus progestin. We assessed retrospectively the incidence of breast cancer in postmenopausal women who received HRT at our outpatients clinic.Methods:  Among the patients registered at the postmenopausal clinic in Kyushu University Hospital from 1990 to 2003, 917 women who received HRT (estrogen plus progestin, 507 patients; estrogen only, 410 patients) after informed consent were examined by mammography or breast ultrasound tomography.Results:  Breast cancer occurred in nine patients: five patients who received estrogen plus progestin and four who received estrogen only. Four of five the patients who used estrogen plus progestin received HRT for more than 5 years.Conclusion:  Breast cancer risk in patients who used estrogen plus progestin for more than 5 years seemed to be higher than those who used it for less than 5 years. This tendency is similar to the results of the WHI. In addition, breast cancer incidence in patients treated with HRT in our clinic seemed to be higher than the incidence in average Japanese women. Therefore, patients need to be given sufficient information before undergoing HRT.
Rapidly growing leiomyoma in a postmenopausal woman
Authors: Okamoto Takako , Koshiyama Masafumi , Yamamoto Keiko 
Published: July 2004

AbstractWe present here a case of a rapidly growing leiomyoma occurring after menopause. The tumor weighed 4329 g, suggesting the rapid accumulation of ‘hyaline fibrosis’. A small amount of proliferative activity was detected as evidenced by Ki‐67 antigen immunoreactivity.
Fasting or two‐hour postprandial plasma glucose levels in early months of pregnancy as screening tools for gestational diabetes mellitus developing in later months of pregnancy
Authors: Bhattacharya Sudhindra Mohan 
Published: July 2004

AbstractPurpose:  The present study was done to find out whether the fasting or 2‐hour postprandial plasma glucose (PPPG) levels in early months of pregnancy can be used as screening tools for gestational diabetes mellitus (GDM) developing in later months of pregnancy.Basic procedure:  Fasting and 2‐hour PPPG levels were measured in the early months of pregnancy in 246 women attending the antenatal clinic of the author. All of the women underwent glucose challenge tests with 50 grams of glucose at 24–28 weeks and if the value exceeded 140 mg%, a three‐hour oral glucose tolerance test (OGTT) with 100 grams of glucose was performed to diagnose GDM.Main findings:  The present study found that the incidence of GDM was 10.5% in the third trimester. Statistical analysis did not show any correlation between fasting and the PPPG values in the early months and GDM in later months of pregnancy.Conclusion:  Fasting or PPPG values cannot be used as efficient screening tools for GDM developing in the later months of pregnancy.
A Viewpoint‐Dependent Approach to Ray Trace Free‐Form Surfaces
Authors: Formella A. , Müller K. 
Published: July 2004

AbstractFor convincing realistic scenes objects with free‐form surfaces are essential. Especially for photorealistic rendering pure polygonal models are often not sufficient. We present a new kind of algorithm to render free‐form surfaces in a rendering system based on ray tracing. We describe a triangular patch as usual by its three points and normal vectors, but base the intersection calculation as well on the viewpoint of the camera (or, in general, on the ray itself). Hence, the shape of the object depends to some extent on the sampling rays. However, the resulting differences of, for instance, the shape of the silhouette to the shape of the corresponding shadow is usually not perceived by the observer of the rendered image. Because we perform a direct computation without a tessellation process, the resulting surface, its shadows, and its reflections appear smooth independent of the distance to the camera. Furthermore, the memory consumption depends only linearly on the number of input triangles. Special features like creases, T‐vertices, and darts are also well supported. The computed uv‐coordinates provide a direct means for texture mapping whose visual appearance improves significantly compared to triangle meshes of the same resolution.
Visualizing Objects with Mirrors
Authors: Hurtado F. , Noy M. , Robert J.‐M. , Sacristán V. , Skiena S. 
Published: July 2004

Abstract We present an automatic camera and mirrors placement method for visualizing 3D scenes such that complete and nonredundant visibility is guaranteed, as well as highest image resolution. We provide algorithms and geometries for optimal object‐independent mirrors and viewpoint placement for all objects in a specific class. We also briefly consider object‐dependent algorithmic problems, where mirrors and viewpoints are positioned as a function of the object.
Image Interpolation by Pixel‐Level Data‐Dependent Triangulation
Authors: Su Dan , Willis Philip 
Published: July 2004

AbstractWe present a novel image interpolation algorithm. The algorithm can be used in arbitrary resolution enhancement, arbitrary rotation and other applications of still images in continuous space. High‐resolution images are interpolated from the pixel‐level data‐dependent triangulation of lower‐resolution images. It is simpler than other methods and is adaptable to a variety of image manipulations. Experimental results show that the new “mesh image” algorithm is as fast as the bilinear interpolation method. We assess the interpolated images' quality visually and also by the MSE measure which shows our method generates results comparable in quality to slower established methods. We also implement our method in graphics card hardware using OpenGL which leads to real‐time high‐quality image reconstruction. These features give it the potential to be used in gaming and image‐processing applications.
Thioesterase II of
Escherichia coli
Plays an Important Role in 3-Hydroxydecanoic Acid Production
Authors: Zheng Zhong , Gong Qiang , Liu Tao , Deng Ying , Chen Jin-Chun , Chen Guo-Qiang 
Published: July 2004

ABSTRACT

3-Hydroxydecanoic acid (3HD) was produced in
Escherichia coli
by mobilizing (
R
)-3-hydroxydecanoyl-acyl carrier protein-coenzyme A transacylase (PhaG, encoded by the
phaG
gene). By employing an isogenic
tesB
(encoding thioesterase II)-negative knockout
E. coli
strain, CH01, it was found that the expressions of
tesB
and
phaG
can up-regulate each other. In addition, 3HD was synthesized from glucose or fructose by recombinant
E. coli
harboring
phaG
and
tesB
. This study supports the hypothesis that the physiological role of thioesterase II in
E. coli
is to prevent the abnormal accumulation of intracellular acyl-coenzyme A.
Thermus thermophilus
as a Cell Factory for the Production of a Thermophilic Mn-Dependent Catalase Which Fails To Be Synthesized in an Active Form in
Escherichia coli
Authors: Hidalgo Aurelio , Betancor Lorena , Moreno Renata , Zafra Olga , Cava Felipe , Fernández-Lafuente Roberto , Guisán José M. , Berenguer José 
Published: July 2004

ABSTRACT

Thermostable Mn-dependent catalases are promising enzymes in biotechnological applications as H
2
O
2
-detoxifying systems. We cloned the genes encoding Mn-dependent catalases from
Thermus thermophilus
HB27 and HB8 and a less thermostable mutant carrying two amino acid replacements (M129V and E293G). When the wild-type and mutant genes were overexpressed in
Escherichia coli
, unmodified or six-His-tagged proteins of the expected size were overproduced as inactive proteins. Several attempts to obtain active forms or to activate the overproduced proteins were unsuccessful, even when soluble and thermostable proteins were used. Therefore, a requirement for a
Thermus-
specific activation factor was suggested. To overcome this problem, the Mn-dependent catalase genes were overexpressed directly in
T. thermophilus
under the control of the
Pnar
promoter. This promoter belongs to a respiratory nitrate reductase from of
T. thermophilus
HB8, whose transcription is activated by the combined action of nitrate and anoxia. Upon induction in
T. thermophilus
HB8, a 20- to 30-fold increase in catalase specific activity was observed, whereas a 90- to 110-fold increase was detected when the laboratory strain
T. thermophilus
HB27::
nar
was used as the host. The thermostability of the overproduced wild-type catalase was identical to that previously reported for the native enzyme, whereas decreased stability was detected for the mutant derivative. Therefore, our results validate the use of
T. thermophilus
as an alternative cell factory for the overproduction of thermophilic proteins that fail to be expressed in well-known mesophilic hosts.
Ability of Thermophilic Lactic Acid Bacteria To Produce Aroma Compounds from Amino Acids
Authors: Helinck Sandra , Le Bars Dominique , Moreau Daniel , Yvon Mireille 
Published: July 2004

ABSTRACT

Although a large number of key odorants of Swiss-type cheese result from amino acid catabolism, the amino acid catabolic pathways in the bacteria present in these cheeses are not well known. In this study, we compared the in vitro abilities of
Lactobacillus delbrueckii
subsp.
lactis
,
Lactobacillus helveticus,
and
Streptococcus thermophilus
to produce aroma compounds from three amino acids, leucine, phenylalanine, and methionine, under mid-pH conditions of cheese ripening (pH 5.5), and we investigated the catabolic pathways used by these bacteria. In the three lactic acid bacterial species, amino acid catabolism was initiated by a transamination step, which requires the presence of an α-keto acid such as α-ketoglutarate (α-KG) as the amino group acceptor, and produced α-keto acids. Only
S. thermophilus
exhibited glutamate dehydrogenase activity, which produces α-KG from glutamate, and consequently only
S. thermophilus
was capable of catabolizing amino acids in the reaction medium without α-KG addition. In the presence of α-KG, lactobacilli produced much more varied aroma compounds such as acids, aldehydes, and alcohols than
S. thermophilus,
which mainly produced α-keto acids and a small amount of hydroxy acids and acids.
L. helveticus
mainly produced acids from phenylalanine and leucine, while
L. delbrueckii
subsp.
lactis
produced larger amounts of alcohols and/or aldehydes. Formation of aldehydes, alcohols, and acids from α-keto acids by
L. delbrueckii
subsp.
lactis
mainly results from the action of an α-keto acid decarboxylase, which produces aldehydes that are then oxidized or reduced to acids or alcohols. In contrast, the enzyme involved in the α-keto acid conversion to acids in
L. helveticus
and
S. thermophilus
is an α-keto acid dehydrogenase that produces acyl coenzymes A.
Accurate Estimation of Viral Abundance by Epifluorescence Microscopy
Authors: Wen Kevin , Ortmann Alice C. , Suttle Curtis A. 
Published: July 2004

ABSTRACT

Virus enumeration by epifluorescence microscopy (EFM) is routinely done on preserved, refrigerated samples. Concerns about obtaining accurate and reproducible estimates led us to examine procedures for counting viruses by EFM. Our results indicate that aldehyde fixation results in rapid decreases in viral abundance. By 1 h postfixation, the abundance dropped by 16.4% ± 5.2% (
n
= 6), and by 4 h, the abundance was 20 to 35% lower. The average loss rates for glutaraldehyde- and formaldehyde-fixed samples over the first 2 h were 0.12 and 0.13 h
−1
, respectively. By 16 days, viral abundance had decreased by 72% (standard deviation, 6%;
n
= 6). Aldehyde fixation of samples followed by storage at 4°C, for even a few hours, resulted in large underestimates of viral abundance. The viral loss rates were not constant, and in glutaraldehyde- and formaldehyde-fixed samples they decreased from 0.13 and 0.17 h
−1
during the first hour to 0.01 h
−1
between 24 and 48 h. Although decay rates changed over time, the abundance was predicted by using separate models to describe decay over the first 8 h and decay beyond 8 h. Accurate estimates of abundance were easily made with unfixed samples stained with Yo-Pro-1, SYBR Green I, or SYBR Gold, and slides could be stored at −20°C for at least 2 weeks or, for Yo-Pro-1, at least 1 year. If essential, samples can be fixed and flash frozen in liquid nitrogen upon collection and stored at −86°C. Determinations performed with fixed samples result in large underestimates of abundance unless slides are made immediately or samples are flash frozen. If protocols outlined in this paper are followed, EFM yields accurate estimates of viral abundance.
The P450 Monooxygenase BcABA1 Is Essential for Abscisic Acid Biosynthesis in
Botrytis cinerea
Authors: Siewers Verena , Smedsgaard Jørn , Tudzynski Paul 
Published: July 2004

ABSTRACT

The phytopathogenic ascomycete
Botrytis cinerea
is known to produce abscisic acid (ABA), which is thought to be involved in host-pathogen interaction. Biochemical analyses had previously shown that, in contrast to higher plants, the fungal ABA biosynthesis probably does not proceed via carotenoids but involves direct cyclization of farnesyl diphosphate and subsequent oxidation steps. We present here evidence that this “direct” pathway is indeed the only one used by an ABA-overproducing strain of
B. cinerea
. Targeted inactivation of the gene
bccpr1
encoding a cytochrome P450 oxidoreductase reduced the ABA production significantly, proving the involvement of P450 monooxygenases in the pathway. Expression analysis of 28 different putative P450 monooxygenase genes revealed two that were induced under ABA biosynthesis conditions. Targeted inactivation showed that one of these,
bcaba1
, is essential for ABA biosynthesis: ΔBcaba1 mutants contained no residual ABA. Thus,
bcaba1
represents the first identified fungal ABA biosynthetic gene.
Disruption of the Subtilase Gene,
albin1
, in
Ophiostoma piliferum
Authors: Hoffman Brad , Breuil Colette 
Published: July 2004

ABSTRACT

Wood sapstaining fungi produce multiple proteases that break down wood protein. Three groups of subtilases have been identified in sapstaining fungi; however, it is not known if these groups have distinct physiological roles (B. Hoffman and C. Breuil, Curr. Genet.
41:
168-175, 2002). In this work we examined the role of the subtilase Albin1 from
Ophiostoma piliferum
. Reamplification of cDNA ends PCR was used to obtain the
albin1
gene sequence. The encoded subtilase is probably extracellular and involved in nutrient acquisition. This gene was disrupted with an
Agrobacterium tumefaciens
-mediated transformation system. Two of the disruptants obtained had significantly lower levels of proteolytic activity, slower growth in bovine serum albumin, and significantly reduced growth on wood. Thus,
albin1
plays an important role in
O. piliferum
's ability to acquire nitrogen from wood proteins.
Rotavirus Virus-Like Particles as Surrogates in Environmental Persistence and Inactivation Studies
Authors: Caballero Santiago , Abad F. Xavier , Loisy Fabienne , Le Guyader Françoise S. , Cohen Jean , Pintó Rosa M. , Bosch Albert 
Published: July 2004

ABSTRACTVirus-like particles (VLPs) with the full-length VP2 and VP6 rotavirus capsid proteins, produced in the baculovirus expression system, have been evaluated as surrogates of human rotavirus in different environmental scenarios. Green fluorescent protein-labeled VLPs (GFP-VLPs) and particles enclosing a heterologous RNA (pseudoviruses), whose stability may be monitored by flow cytometry and antigen capture reverse transcription-PCR, respectively, were used. After 1 month in seawater at 20°C, no significant differences were observed between the behaviors of GFP-VLPs and of infectious rotavirus, whereas pseudovirus particles showed a higher decay rate. In the presence of 1 mg of free chlorine (FC)/liter both tracers persisted longer in freshwater at 20°C than infectious viruses, whereas in the presence of 0.2 mg of FC/liter no differences were observed between tracers and infectious rotavirus at short contact times. However, from 30 min of contact with FC onward, the decay of infectious rotavirus was higher than that of recombinant particles. The predicted Ct value for a 90% reduction of GFP-VLPs or pseudoviruses induces a 99.99% inactivation of infectious rotavirus. Both tracers were more resistant to UV light irradiation than infectious rotavirus in fresh and marine water. The effect of UV exposure was more pronounced on pseudovirus than in GFP-VLPs. In all types of water, the UV dose to induce a 90% reduction of pseudovirus ensures a 99.99% inactivation of infectious rotavirus. Recombinant virus surrogates open new possibilities for the systematic validation of virus removal practices in actual field situations where pathogenic agents cannot be introduced.
Analysis and Validation of a Predictive Model for Growth and Death ofAeromonas hydrophilaunder Modified Atmospheres at Refrigeration Temperatures
Authors: Pin Carmen , Velasco de Diego Raquel , George Susan , García de Fernando Gonzalo D. , Baranyi József 
Published: July 2004

ABSTRACTSpecific growth and death rates ofAeromonas hydrophilawere measured in laboratory media under various combinations of temperature, pH, and percent CO2and O2in the atmosphere. Predictive models were developed from the data and validated by means of observations obtained from (i) seafood experiments set up for this purpose and (ii) the ComBase database (http://www.combase.cc;http://wyndmoor.arserrc.gov/combase/).Two main reasons were identified for the differences between the predicted and observed growth in food: they were the variability of the growth rates in food and the bias of the model predictions when applied to food environments. A statistical method is presented to quantitatively analyze these differences. The method was also used to extend the interpolation region of the model. In this extension, the concept of generalizedZvalues (C. Pin, G. García de Fernando, J. A. Ordóñez, and J. Baranyi, Food Microbiol.18:539-545, 2001) played an important role. The extension depended partly on the density of the model-generating observations and partly on the accuracy of extrapolated predictions close to the boundary of the interpolation region. The boundary of the growth region of the organism was also estimated by means of experimental results for growth and death rates.
Properties of a Novel Thermostable Glucoamylase from the Hyperthermophilic Archaeon
Sulfolobus solfataricus
in Relation to Starch Processing
Authors: Kim Mi-Sun , Park Jong-Tae , Kim Young-Wan , Lee Hee-Seob , Nyawira Rose , Shin Hyoun-Seung , Park Cheon-Seok , Yoo Sang-Ho , Kim Yong-Ro , Moon Tae-Wha , Park Kwan-Hwa 
Published: July 2004

ABSTRACT

A gene (
ssg
) encoding a putative glucoamylase in a hyperthermophilic archaeon,
Sulfolobus solfataricus
, was cloned and expressed in
Escherichia coli
, and the properties of the recombinant protein were examined in relation to the glucose production process. The recombinant glucoamylase was extremely thermostable, with an optimal temperature at 90°C. The enzyme was most active in the pH range from 5.5 to 6.0. The enzyme liberated β-
d
-glucose from the substrate maltotriose, and the substrate preference for maltotriose distinguished this enzyme from fungal glucoamylases. Gel permeation chromatography and sedimentation equilibrium analytical ultracentrifugation analysis revealed that the enzyme exists as a tetramer. The reverse reaction of the glucoamylase from
S. solfataricus
produced significantly less isomaltose than did that of industrial fungal glucoamylase. The glucoamylase from
S. solfataricus
has excellent potential for improving industrial starch processing by eliminating the need to adjust both pH and temperature.
A New Black
Aspergillus
Species,
A. vadensis
, Is a Promising Host for Homologous and Heterologous Protein Production
Authors: de Vries Ronald P. , Burgers Kim , van de Vondervoort Peter J. I. , Frisvad Jens C. , Samson Robert A. , Visser Jaap 
Published: July 2004

ABSTRACT

A new species of the group of black aspergilli,
Aspergillus vadensis
, was analyzed for its potential as a host for homologous and heterologous protein production. Unlike the other black aspergilli, this strain does not acidify the culture medium when nitrate is the nitrogen source and only produces very low levels of extracellular proteases, mainly serine metalloproteases. The stability of
A. tubingensis
feruloyl esterase A (FaeA) was compared upon production in wild-type
A. vadensis
,
A. tubingensis
, and an
A. niger
strain in which the three main protease-encoding genes were disrupted. The production of FaeA in
A. vadensis
resulted in larger amounts of intact protein than production in
A. tubingensis
and was similar to production in an
A. niger
protease disruptant, confirming in vivo the low proteolytic activity of
A. vadensis
. The protoplast formation and transformation efficiencies of
A. vadensis
were much higher than those of
A. niger
. These characteristics make
A. vadensis
a very promising candidate for homologous, and possibly heterologous, protein production.
Disruption of a Gene Predicted To Encode a Solute Binding Protein of an ABC Transporter Reduces Transmission of
Spiroplasma citri
by the Leafhopper
Circulifer haematoceps
Authors: Boutareaud A. , Danet J. L. , Garnier M. , Saillard C. 
Published: July 2004

ABSTRACT

Spiroplasma citri
is transmitted from plant to plant by phloem-feeding leafhoppers. In an attempt to identify mechanisms involved in transmission, mutants of
S. citri
affected in their transmission must be available. For this purpose, transposon (Tn
4001
) mutagenesis was used to produce mutants which have been screened for their ability to be transmitted by the leafhopper vector
Circulifer haematoceps
to periwinkle plants. With one mutant (G76) which multiplied in leafhoppers as efficiently as
S. citri
wild-type (wt) strain GII-3, the plants showed symptoms 4 to 5 weeks later than those infected with wt GII-3. Thirty to fifty percent of plants exposed to leafhoppers injected with G76 remained symptomless, whereas for wt GII-3, all plants exposed to the transmission showed severe symptoms. This suggests that the mutant G76 was injected into plants by the leafhoppers less efficiently than wt GII-3. To check this possibility, the number of spiroplasma cells injected by a leafhopper through a Parafilm membrane into SP4 medium was determined. Thirty times less mutant G76 than wt GII-3 was transmitted through the membrane. These results suggest that mutant G76 was affected either in its capacity to penetrate the salivary glands and/or to multiply within them. In mutant G76, transposon Tn
4001
was shown to be inserted into a gene encoding a putative lipoprotein (Sc76) In the ABCdb database Sc76 protein was noted as a solute binding protein of an ABC transporter of the family S1_b. Functional complementation of the G76 mutant with the
Sc76
gene restored the wild phenotype, showing that Sc76 protein is involved in
S. citri
transmission by the leafhopper vector
C. haematoceps
.