bluuebunny/crossref_metadata_2025_split huggingface dataset:
Converting the NiFeS Carbon Monoxide Dehydrogenase to a Hydrogenase and a Hydroxylamine Reductase
Authors: Heo Jongyun , Wolfe Marcus T. , Staples Christopher R. , Ludden Paul W. 
Published: October 2002

ABSTRACTSubstitution of one amino acid for another at the active site of an enzyme usually diminishes or eliminates the activity of the enzyme. In some cases, however, the specificity of the enzyme is changed. In this study, we report that the changing of a metal ligand at the active site of the NiFeS-containing carbon monoxide dehydrogenase (CODH) converts the enzyme to a hydrogenase or a hydroxylamine reductase. CODH with alanine substituted for Cys531exhibits substantial uptake hydrogenase activity, and this activity is enhanced by treatment with CO. CODH with valine substituted for His265exhibits hydroxylamine reductase activity. Both Cys531and His265are ligands to the active-site cluster of CODH. Further, CODH with Fe substituted for Ni at the active site acquires hydroxylamine reductase activity.
DNA Inversion on Conjugative Plasmid pVT745
Authors: Chen Jinbiao , Leblanc Donald J. , Galli Dominique M. 
Published: October 2002

ABSTRACT

Plasmid pVT745 from
Actinobacillus actinomycetemcomitans
strain VT745 can be transferred to other
A. actinomycetemcomitans
strains at a frequency of 10
−6
. Screening of transconjugants revealed that the DNA of pDMG21A, a pVT745 derivative containing a kanamycin resistance gene, displayed a structural rearrangement after transfer. A 9-kb segment on the plasmid had switched orientation. The inversion was independent of RecA and required the activity of the pVT745-encoded site-specific recombinase. This recombinase, termed Inv, was highly homologous to invertases of the Din family. Two recombination sites of 22 bp, which are arranged in opposite orientation and which function as DNA crossover sequences, were identified on pVT745. One of the sites was located adjacent to the 5′ end of the invertase gene,
inv
. Inversion of the 9-kb segment on pVT745 derivatives has been observed in all
A. actinomycetemcomitans
strains tested except for the original host, VT745. This would suggest that a host factor that is either inactive or absent in VT745 is required for efficient recombination. Inactivation of the invertase in the donor strain resulted in a 1,000-fold increase in the number of transconjugants upon plasmid transfer. It is proposed that an activated invertase causes the immediate loss of the plasmid in most recipient cells after mating. No biological role has been associated with the invertase as of yet.
The First Archaeal ATP-Dependent Glucokinase, from the Hyperthermophilic Crenarchaeon
Aeropyrum pernix
, Represents a Monomeric, Extremely Thermophilic ROK Glucokinase with Broad Hexose Specificity
Authors: Hansen Thomas , Reichstein Bianca , Schmid Roland , Schönheit Peter 
Published: October 2002

ABSTRACT

An ATP-dependent glucokinase of the hyperthermophilic aerobic crenarchaeon
Aeropyrum pernix
was purified 230-fold to homogeneity. The enzyme is a monomeric protein with an apparent molecular mass of about 36 kDa. The apparent

K
m

values for ATP and glucose (at 90°C and pH 6.2) were 0.42 and 0.044 mM, respectively; the apparent
V
max
was about 35 U/mg. The enzyme was specific for ATP as a phosphoryl donor, but showed a broad spectrum for phosphoryl acceptors: in addition to glucose, which showed the highest catalytic efficiency (
k
cat
/

K
m

), the enzyme also phosphorylates glucosamin, fructose, mannose, and 2-deoxyglucose. Divalent cations were required for maximal activity: Mg
2+
, which was most effective, could partially be replaced with Co
2+
, Mn
2+
, and Ni
2+
. The enzyme had a temperature optimum of at least 100°C and showed significant thermostability up to 100°C. The coding function of open reading frame (ORF) APE2091 (Y. Kawarabayasi, Y. Hino, H. Horikawa, S. Yamazaki, Y. Haikawa, K. Jin-no, M. Takahashi, M. Sekine, S. Baba, A. Ankai, H. Kosugi, A. Hosoyama, S. Fukui, Y. Nagai, K. Nishijima, H. Nakazawa, M. Takamiya, S. Masuda, T. Funahashi, T. Tanaka, Y. Kudoh, J. Yamazaki, N. Kushida, A. Oguchi, and H. Kikuchi, DNA Res. 6:83-101, 145-152, 1999), previously annotated as gene
glk
, coding for ATP-glucokinase of
A. pernix
, was proved by functional expression in
Escherichia coli
. The purified recombinant ATP-dependent glucokinase showed a 5-kDa higher molecular mass on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, but almost identical kinetic and thermostability properties in comparison to the native enzyme purified from
A. pernix.
N-terminal amino acid sequence of the native enzyme revealed that the translation start codon is a GTG 171 bp downstream of the annotated start codon of ORF APE2091. The amino acid sequence deduced from the truncated ORF APE2091 revealed sequence similarity to members of the ROK family, which comprise bacterial sugar kinases and transcriptional repressors. This is the first report of the characterization of an ATP-dependent glucokinase from the domain of
Archaea
, which differs from its bacterial counterparts by its monomeric structure and its broad specificity for hexoses.
The Dilemma of Phage Taxonomy Illustrated by Comparative Genomics of Sfi21-LikeSiphoviridaein Lactic Acid Bacteria
Authors: Proux Caroline , van Sinderen Douwe , Suarez Juan , Garcia Pilar , Ladero Victor , Fitzgerald Gerald F. , Desiere Frank , Brüssow Harald 
Published: October 2002

ABSTRACTThe complete genome sequences of two dairy phages,Streptococcus thermophilusphage 7201 andLactobacillus caseiphage A2, are reported. Comparative genomics reveals that both phages are members of the recently proposed Sfi21-like genus ofSiphoviridae, a widely distributed phage type in low-GC-content gram-positive bacteria. Graded relatedness, the hallmark of evolving biological systems, was observed when different Sfi21-like phages were compared. Across the structural module, the graded relatedness was represented by a high level of DNA sequence similarity or protein sequence similarity, or a shared gene map in the absence of sequence relatedness. This varying range of relatedness was found within Sfi21-like phages from a single species as demonstrated by the different prophages harbored byLactococcus lactisstrain IL1403. A systematic dot plot analysis with 11 completeL. lactisphage genome sequences revealed a clear separation of all temperate phages from two classes of virulent phages. The temperate lactococcal phages share DNA sequence homology in a patchwise fashion over the nonstructural gene cluster. With respect to structural genes, four DNA homology groups could be defined within temperateL. lactisphages. Closely related structural modules for all four DNA homology groups were detected in phages fromStreptococcusorListeria, suggesting that they represent distinct evolutionary lineages that have not uniquely evolved inL. lactis. It seems reasonable to base phage taxonomy on data from comparative genomics. However, the peculiar modular nature of phage evolution creates ambiguities in the definition of phage taxa by comparative genomics. For example, depending on the module on which the classification is based, temperate lactococcal phages can be classified as a single phage species, as four distinct phage species, or as two if not three different phage genera. We propose to base phage taxonomy on comparative genomics of a single structural gene module (head or tail genes). This partially phylogeny-based taxonomical system still mirrors some aspects of the current International Committee on Taxonomy in Virology classification system. In this system the currently sequenced lactococcal phages would be grouped into five genera: c2-, sk1, Sfi11-, r1t-, and Sfi21-like phages.
Conserved Filamentous Prophage in
Escherichia coli
O18:K1:H7 and
Yersinia pestis
Biovar orientalis
Authors: Gonzalez Mark D. , Lichtensteiger Carol A. , Caughlan Ruth , Vimr Eric R. 
Published: October 2002

ABSTRACT

Microbial virulence is known to emerge by horizontal gene transfer mechanisms. Here we describe the discovery of a novel filamentous prophage, designated CUS-1, which is integrated into the chromosomal
dif
homologue of the high-virulence clone
Escherichia coli
O18:K1:H7. An homologous chromosomal element (CUS-2) in
Yersinia pestis
biovar orientalis is integrated at the same relative location as CUS-1; both lysogenic
E. coli
and
Y. pestis
strains produce particles with properties expected of single-stranded DNA virions. CUSφ is epidemiologically correlated with the emergence of K1 strains with increased virulence and with the
Y. pestis
biovar responsible for the current (third) plague pandemic.
The G20210A mutation does not affect the stability of prothrombin mRNA in vivo
Authors: Pollak Eleanor S. , Lam Ho-Sun , Russell J. Eric 
Published: October 2002

AbstractThe activated form of prothrombin plays pivotal roles in the regulation of crucial coagulation, fibrinolytic, and cellular processes. Among several congenital genetic defects affecting the prothrombin gene, a G→A mutation at position 20210—the accepted polyadenylation site—has been linked to hyperprothrombinemia and a corresponding increase in venous and arterial thrombotic risk. The current study substantiates the hypothesis that the 20210A mutation effects posttranscriptional dysregulation of the prothrombin messenger RNA (mRNA). Moreover, data from experiments carried out in fresh liver tissue indicate that the 20210A mutation does not affect prothrombin mRNA stability but, rather, effects a change in the location of the 3′-cleavage/polyadenylation reaction. Based upon this evidence, we propose an alternate model for the dysregulated expression of the prothrombin 20210A gene that does not require a change in the stability of its mRNA.
Homozygous factor V splice site mutation associated with severe factor V deficiency
Authors: Schrijver Iris , Koerper Marion A. , Jones Carol D. , Zehnder James L. 
Published: October 2002

Abstract
We investigated a family whose proband has a severe bleeding disorder and factor V antigenic and functional levels of 8% and less than 1% of control values, respectively. Molecular analysis of the factor V gene revealed a novel homozygous mutation in the last nucleotide of exon 10. 1701G&gt;T causes activation of a cryptic exonic splice site in exon 10, which encodes part of the factor V heavy chain (A2 domain). This leads to the deletion of 35 nucleotides and results in a frameshift with a premature stop codon at amino acid position 498. The G1701 and corresponding Gln509 are conserved in murine, bovine, and porcine factor V and in human factor VIII. Few factor V deficiency mutations have been identified as yet. Several are present in the heterozygous form in combination with factor V Leiden (Arg506Gln). This is the first reported homozygous splice site mutation in a patient with factor V deficiency.
High-dose chemo-radioimmunotherapy with autologous stem cell support for relapsed mantle cell lymphoma
Authors: Gopal Ajay K. , Rajendran Joseph G. , Petersdorf Stephen H. , Maloney David G. , Eary Janet F. , Wood Brent L. , Gooley Theodore A. , Bush Sharon A. , Durack Lawrence D. , Martin Paul J. , Matthews Dana C. , Appelbaum Frederick R. , Bernstein Irwin D. , Press Oliver W. 
Published: October 2002

Abstract
Relapsed mantle cell lymphoma is a radiation-sensitive malignancy that is unlikely to be cured by treatment with conventional high-dose therapy and autologous stem cell transplantation. We tested the safety and efficacy of using a CD20-specific monoclonal antibody conjugated with 131I to deliver high-dose radiation selectively to all lymphoma sites. Patients with relapsed or refractory mantle cell lymphoma received infusions of 131I-labeled CD20-specific monoclonal antibody (Tositumomab). The antibody dose was 1.7 mg/kg body weight, and the amount of 131I was calibrated to deliver 20 to 25 Gy to vital normal organs. This treatment was followed 10 days later by administration of high-dose etoposide (30-60 mg/kg), cyclophosphamide (60-100 mg/kg), and infusion of cryopreserved autologous stem cells. The 16 patients in this study had received a median of 3 prior treatments, and 7 had chemotherapy-resistant disease. The median dose of 131I was 510 mCi (18.87 GBq). There were no therapy-related deaths. Among the 11 patients with conventionally measurable disease at the time of treatment, the respective complete and overall response rates were 91% and 100%. Fifteen patients remain alive, and 12 have had no progression of lymphoma at 6 to 57 months from transplantation and 16 to 97 months from diagnosis. Overall survival at 3 years from transplantation is estimated at 93%, and progression-free survival is estimated at 61%. High-dose treatment with 131I-Tositumomab, etoposide, and cyclophosphamide results in a high remission rate and may provide long-term disease-free survival for patients with relapsed or refractory mantle cell lymphoma.
Inhibition of PDE4 phosphodiesterase activity induces growth suppression, apoptosis, glucocorticoid sensitivity, p53, and p21WAF1/CIP1 proteins in human acute lymphoblastic leukemia cells
Authors: Ogawa Ryosuke , Streiff Michael B. , Bugayenko Artem , Kato Gregory J. 
Published: October 2002

AbstractGlucocorticoids are integral to successful treatment of childhood acute lymphoblastic leukemia (ALL) and other lymphoid malignancies. A large body of data indicates that in various model systems, elevation of cyclic adenosine monophosphate (cAMP) can potentiate glucocorticoid response, although this has not been well evaluated as a potential leukemia treatment. Although cAMP analogs have been studied, little data exist regarding the potential toxicity to leukemia cells of pharmacologic elevation of cAMP levels in leukemic blasts. Using MTT assays of cell proliferation on CEM ALL cells, we found that aminophylline and other nonspecific phosphodiesterase (PDE) inhibitors suppress cell growth. This effect is replicated by the PDE4-specific PDE inhibitor rolipram, but not by specific inhibitors of the PDE1 or PDE3 classes. We found that PDE inhibitors cause increased dexamethasone sensitivity and a synergistic effect with the adenylyl cyclase activator forskolin. We observed several important cellular characteristics associated with this treatment, including elevation of cAMP, induction of p53 and p21WAF1/CIP1proteins, G1 and G2/M cell cycle arrest, and increased apoptosis. Sensitivity to forskolin and rolipram is shared by at least 2 pediatric ALL cell lines, CEM and Reh cells. Some cell lines derived from adult-type lymphoid malignancies also show sensitivity to this treatment. These findings suggest that PDE inhibitors have therapeutic potential in human ALL and characterize the molecular mechanisms that may be involved in this response.
BRCAPRO Validation, Sensitivity of Genetic Testing of BRCA1/BRCA2, and Prevalence of Other Breast Cancer Susceptibility Genes
Authors: Berry Donald A. , Iversen Edwin S. , Gudbjartsson Daniel F. , Hiller Elaine H. , Garber Judy E. , Peshkin Beth N. , Lerman Caryn , Watson Patrice , Lynch Henry T. , Hilsenbeck Susan G. , Rubinstein Wendy S. , Hughes Kevin S. , Parmigiani Giovanni 
Published: October 2002

PURPOSE: To compare genetic test results for deleterious mutations of BRCA1 and BRCA2 with estimated probabilities of carrying such mutations; to assess sensitivity of genetic testing; and to assess the relevance of other susceptibility genes in familial breast and ovarian cancer. PATIENTS AND METHODS: Data analyzed were from six high-risk genetic counseling clinics and concern individuals from families for which at least one member was tested for mutations at BRCA1 and BRCA2. Predictions of genetic predisposition to breast and ovarian cancer for 301 individuals were made using BRCAPRO, a statistical model and software using Mendelian genetics and Bayesian updating. Model predictions were compared with the results of genetic testing. RESULTS: Among the test individuals, 126 were Ashkenazi Jewish, three were male subjects, 243 had breast cancer, 49 had ovarian cancer, 34 were unaffected, and 139 tested positive for BRCA1 mutations and 29 for BRCA2 mutations. BRCAPRO performed well: for the 150 probands with the smallest BRCAPRO carrier probabilities (average, 29.0%), the proportion testing positive was 32.7%; for the 151 probands with the largest carrier probabilities (average, 95.2%), 78.8% tested positive. Genetic testing sensitivity was estimated to be at least 85%, with false-negatives including mutations of susceptibility genes heretofore unknown. CONCLUSION: BRCAPRO is an accurate counseling tool for determining the probability of carrying mutations of BRCA1 and BRCA2. Genetic testing for BRCA1 and BRCA2 is highly sensitive, missing an estimated 15% of mutations. In the populations studied, breast cancer susceptibility genes other than BRCA1 and BRCA2 either do not exist, are rare, or are associated with low disease penetrance.
Triplet Combination With Irinotecan Plus Oxaliplatin Plus Continuous-Infusion Fluorouracil and Leucovorin as First-Line Treatment in Metastatic Colorectal Cancer: A Multicenter Phase II Trial
Authors: Souglakos J. , Mavroudis D. , Kakolyris S. , Kourousis Ch. , Vardakis N. , Androulakis N. , Agelaki S. , Kalbakis K. , Tsetis D. , Athanasiadis N. , Samonis G. , Georgoulias V. 
Published: October 2002

PURPOSE: To evaluate the efficacy and tolerance of irinotecan (CPT-11) in combination with oxaliplatin (l-OHP) plus fluorouracil (5-FU)/leucovorin (LV) (de Gramont regimen) as first-line treatment of metastatic colorectal cancer (MCC). PATIENTS AND METHODS: Thirty-one patients with MCC who had not received prior therapy for metastatic disease were enrolled. Their median age was 60 years; performance status (World Health Organization) was 0 in 12, 1 in 14, and 2 in five patients; 19 patients (61%) had prior surgery, and 14 (45%) had adjuvant chemotherapy. CPT-11 was administered on day 1 at 150 mg/m2 as a 90-minute intravenous (IV) infusion; l-OHP was administered on day 2 at 65 mg/m2 as a 2-hour IV infusion; and on days 2 and 3, LV 200 mg/m2 preceded 5-FU administration of 400 mg/m2/d initial IV bolus dose followed by 600 mg/m2/d 22-hour IV continuous infusion. The regimen was repeated every 2 weeks. RESULTS: All patients were assessable for toxicity and 30 for response to treatment. Complete response was achieved in two patients (6.5%) and partial response in 16 (51.6%) (overall response rate, 58.1%; 95% confidence interval, 40.7% to 75.4%); eight patients (25.8%) had stable disease, and five (16.1%) had disease progression. The median duration of response was 9 months, and the median time to disease progression was 13 months. Neutropenia grade 3 to 4 occurred in 14 patients (45%) and febrile neutropenia in two (6%). Diarrhea grade 3 to 4 was observed in 10 patients (32%), neurotoxicity grade 3 to 4 in three (9%), and asthenia grade 3 in two (10%). No treatment-related death has occurred. CONCLUSION: The triplet combination of 5-FU/LV + CPT-11 + l-OHP is a highly active regimen with manageable toxicity as front-line treatment in MCC.
Temozolomide Plus Thalidomide in Patients With Advanced Melanoma: Results of a Dose-Finding Trial
Authors: Hwu Wen-Jen , Krown Susan E. , Panageas Katherine S. , Menell Jennifer H. , Chapman Paul B. , Livingston Philip O. , Williams Linda J. , Quinn Carolyn J. , Houghton Alan N. 
Published: October 2002

PURPOSE: To establish a safe and tolerated regimen of an oral cytotoxic agent, temozolomide, and a cytostatic agent, thalidomide, in patients with unresectable stage III or IV malignant melanoma. PATIENTS AND METHODS: Patients with unresectable stage III or IV melanoma without brain metastases were entered successively onto four treatment cohorts: level 1, temozolomide 50 mg/m2/d for 6 weeks followed by a 4-week break; levels 2, 3, and 4, temozolomide 75 mg/m2/d for 6 weeks followed, respectively, by breaks of 4, 3, and 2 weeks. Thalidomide was started at 200 mg/d, and escalated to a maximum dose of 400 mg/d. Safety was assessed at weeks 2 and 4 and every 4 weeks thereafter; tumor response was evaluated every 8 to 10 weeks. RESULTS: Twelve patients were enrolled, three on each cohort. Therapy was generally well tolerated on all of the treatment schedules. Thalidomide at a dose of 400 mg/d was well tolerated in patients younger than 70, and 200 mg/d was well tolerated in older patients. The most common adverse events were grade 2 or 3 constipation and neuropathy, which were attributed to thalidomide. Five major responses (one complete, four partial) were documented, all at dose levels 2 to 4. Three of the five responding patients were in the over-70 age group. The median duration of response was 6 months (range, 4 to 17+ months), and the median overall survival was 12.3 months (range, 4 to 19+ months). CONCLUSION: The combination of temozolomide and thalidomide was well tolerated and had antitumor activity in patients with advanced melanoma, including elderly patients over 70 years old.
Hepatitis C virus replicates in sweat glands and is released into sweat in patients with chronic hepatitis C
Authors: Ortiz‐Movilla Nuria , Lázaro Pablo , Rodríguez‐Iñigo Elena , Bartolomé Javier , Longo Isabel , Lecona Manuel , Pardo Margarita , Carreño Vicente 
Published: October 2002

AbstractHepatitis C virus (HCV) replicates in salivary glands of chronic hepatitis C patients and is released into the saliva, suggesting that HCV may replicate in other exocrine glands. The presence of positive and negative HCV RNA strands was demonstrated by in situ hybridization, and of HCV core protein by immunohistochemistry, in sweat glands and keratinocytes in healthy skin biopsies from 15 patients with chronic hepatitis C and 10 anti‐HCV negative patients with chronic liver disease. Positive and negative HCV RNA strands were detected in 9.6 ± 5.2% and 4.2 ± 3.8%, respectively, of the epithelial cells of eccrine sweat glands. Core protein was detected in 6.0 ± 3.93% of these cells. HCV RNA resistant to RNase digestion (encapsidated HCV RNA) was detected in 10/10 sweat samples from HCV‐infected patients. Positive and negative HCV RNA strands were detected in 6.7 ± 2.97% and 3.0 ± 3.08% of the keratinocytes, respectively. HCV core protein was found in 4.5 ± 2.76% of these cells. No HCV RNA or HCV core protein was detected in the skin biopsies from the 10 anti‐HCV negative patients. In conclusion, HCV replicates in eccrine sweat glands cells and keratinocytes in healthy skin and is released into the sweat. J. Med. Virol. 68:529–536, 2002. © 2002 Wiley‐Liss, Inc.