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1.
Virulence ; 11(1): 695-706, 2020 01 01.
Article in English | MEDLINE | ID: mdl-32490711

ABSTRACT

Surgical site infection risk continues to increase due to lack of efficacy in current standard of care drugs. New methods to treat or prevent antibiotic-resistant bacterial infections are needed. Multivalent Adhesion Molecules (MAM) are bacterial adhesins required for virulence. We developed a bacterial adhesion inhibitor using recombinant MAM fragment bound to polymer scaffold, mimicking MAM7 display on the bacterial surface. Here, we test MAM7 inhibitor efficacy to prevent Gram-positive and Gram-negative infections. Using a rodent model of surgical infection, incision sites were infected with antibiotic-resistant bioluminescent strains of Staphylococcus aureus or Pseudomonas aeruginosa. Infections were treated with MAM7 inhibitor or control suspension. Bacterial abundance was quantified for nine days post infection. Inflammatory responses and histology were characterized using fixed tissue sections. MAM7 inhibitor treatment decreased burden of S. aureus and P. aeruginosa below detection threshold. Bacterial load of groups treated with control were significantly higher than MAM7 inhibitor-treated groups. Treatment with inhibitor reduced colonization of clinically-relevant pathogens in an in vivo model of surgical infection. Use of MAM7 inhibitor to block initial adhesion of bacteria to tissue in surgical incisions may reduce infection rates, presenting a strategy to mitigate overuse of antibiotics to prevent surgical site infections.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacterial Adhesion/drug effects , Gram-Negative Bacterial Infections/prevention & control , Surgical Wound Infection/microbiology , Surgical Wound Infection/prevention & control , Animals , Bacterial Load , Gram-Negative Bacterial Infections/drug therapy , Gram-Positive Bacterial Infections/drug therapy , Gram-Positive Bacterial Infections/prevention & control , Male , Pseudomonas Infections/drug therapy , Pseudomonas Infections/prevention & control , Rats, Sprague-Dawley , Skin/microbiology , Skin/pathology , Staphylococcal Infections/drug therapy , Staphylococcal Infections/prevention & control , Virulence
2.
J Clin Endocrinol Metab ; 99(4): 1245-52, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24512493

ABSTRACT

BACKGROUND: Poorly differentiated thyroid cancer (PDTC) accounts for only 1-15% of all thyroid cancers. Our objective is to report outcomes in a large series of patients with PDTC treated at a single tertiary care cancer center. METHODS: A total of 91 patients with primary PDTC were treated by initial surgery with or without adjuvant therapy at Memorial Sloan-Kettering Cancer Center from 1986 to 2009. Outcomes were calculated by the Kaplan-Meier method. Clinicopathological characteristics were compared for PDTC patients who died of disease to those who did not by the χ(2) test. Factors predictive of disease-specific survival (DSS) were calculated by univariate and multivariate analysis using the log rank and Cox proportional hazards method, respectively. RESULTS: With a median follow-up of 50 months, the 5-year overall survival and DSS were 62 and 66%, respectively. The 5-year locoregional and distant control were 81 and 59%, respectively. Of 27 disease-specific deaths, 23 (85%) were due to distant disease. Age ≥ 45 years, pathological tumor size >4 cm, extrathyroidal extension, higher pathological T stage, positive margins, and distant metastases (M1) were predictive of worse DSS on univariate analysis. Multivariate analysis showed that only pT4a stage and M1 were independent predictors of worse DSS. CONCLUSIONS: With appropriate surgery and adjuvant therapy, excellent locoregional control can be achieved in PDTC. Disease-specific deaths occurred due to distant metastases and rarely due to uncontrolled locoregional recurrence in this series.


Subject(s)
Carcinoma/pathology , Carcinoma/therapy , Thyroid Neoplasms/pathology , Thyroid Neoplasms/therapy , Adolescent , Adult , Aged , Aged, 80 and over , Carcinoma/mortality , Combined Modality Therapy/statistics & numerical data , Female , Follow-Up Studies , Humans , Iodine Radioisotopes/therapeutic use , Male , Middle Aged , Prognosis , Recurrence , Thyroid Neoplasms/mortality , Thyroidectomy/statistics & numerical data , Treatment Outcome , Young Adult
3.
Environ Sci Technol ; 36(19): 4065-73, 2002 Oct 01.
Article in English | MEDLINE | ID: mdl-12380076

ABSTRACT

Reactions of bisulfide and polysulfides with alachlor, propachlor, and metolachlor were examined in aqueous solution to investigate the role reduced sulfur species could play in effecting abiotic transformations of chloroacetanilide herbicides. Experiments at 25 degrees C demonstrated that reactions were approximately first-order in HS- concentration and revealed that polysulfides are considerably more reactive than HS-. delta H not equal to values for reactions of the three chloroacetanilides with HS- are statistically indistinguishable at the 95% confidence level, as are delta S not equal to values, despite significant differences in second-order rate constants (kHS-). Transformation products were characterized by GC/MS (in some cases following methylation) and were found to be consistent with substitution of chlorine by the sulfur nucleophile. Products containing multiple sulfur atoms were observed for the reactions of chloroacetanilides with polysulfides, while products resulting from reaction with HS- only possessed a single sulfur atom. When second-order rate constants at 25 degrees C are multiplied by HS- and polysulfide concentrations reported in salt marsh porewaters, predicted half-lives range from minutes to hours. HS- and especially polysulfides could thus exert a substantial influence on the fate of chloroacetanilide herbicides in aquatic environments. Oxidation of the resulting sulfur-substituted products could generate ethane sulfonic acid derivatives, previously reported as prevalent chloroacetanilide degradates.


Subject(s)
Acetamides/chemistry , Acetanilides/chemistry , Herbicides/chemistry , Sulfides/chemistry , Environmental Pollutants/analysis , Gas Chromatography-Mass Spectrometry , Oxidation-Reduction , Temperature
4.
Acad Radiol ; 8(8): 705-12, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11508749

ABSTRACT

RATIONALE AND OBJECTIVES: The authors performed this study to evaluate whether a digital processing technique called disparity processing (DP) can improve the differentiation between benign and malignant breast masses at ultrasound (US) and, thus, reduce the number of benign lesions being sampled for biopsy. MATERIALS AND METHODS: During an US examination, a sonographer slightly varies the pressure of the probe on the breast surface. DP can be used to evaluate pairs of B scans that represent the different parts of this compression cycle. The apparent displacement of the tissue is measured with DP, and a new image, called a correlation map, is constructed. This new image illustrates the similarity between the speckle patterns around each point. The authors evaluated 25 solid lesions with DP. Results were compared with those from (a) histologic examination of specimens obtained with core or surgical biopsy or (b) cytologic examination of specimens obtained with fine-needle aspiration. RESULTS: All 25 lesions were correctly diagnosed with DP. There were no false-positive or false-negative findings. All malignancies demonstrated a relatively low-brightness halo around the lesion perimeter with evidence of discontinuity. All benign lesions were associated with relatively high-brightness, continuous halos. CONCLUSION: The results suggest that DP can help differentiate benign from malignant masses.


Subject(s)
Breast Neoplasms/diagnostic imaging , Image Interpretation, Computer-Assisted/methods , Signal Processing, Computer-Assisted , Diagnosis, Differential , Female , Humans , Ultrasonography
5.
Dev Comp Immunol ; 25(3): 219-29, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11164887

ABSTRACT

Proteins of the STAT family (Signal Transducers and Activators of Transcription) are latent cytoplasmic factors which, upon phosphorylation, are translocated to the nucleus where they participate in gene activation. In this report, we describe the cloning and developmental expression of a Xenopus homolog of Stat1. XStat1 is highly conserved, exhibiting greater than 90% identity in the critical DNA binding, SH2, SH3 and trans-activation domains with both human and murine Stat1. Using RT-PCR, we show that XStat1 is present as a maternal message during early development of Xenopus. The maternal message is translated during cleavage and its product is phosphorylated on tyrosine, a prerequisite for functional activation. During cleavage and gastrula stages, XStat1 is widely expressed throughout the developing embryo. During neurulation and early tailbud stages, XStat1 is expressed in both dorsal axial and ventral tissues. By late tailbud, dorsal XStat1 expression domains are associated with the developing pharyngeal arches and pronephros. These regions of the embryo correspond to the future location of the thymus, sites of dorsal hematopoietic activity, and one location where melanocytes differentiate.


Subject(s)
DNA-Binding Proteins/genetics , Trans-Activators/genetics , Xenopus/genetics , Amino Acid Sequence , Animals , Base Sequence , Cloning, Molecular , Consensus Sequence , Conserved Sequence , DNA Primers/genetics , Female , Gene Expression Regulation, Developmental , Humans , In Situ Hybridization , Mice , Molecular Sequence Data , Protein Biosynthesis , Reverse Transcriptase Polymerase Chain Reaction , STAT1 Transcription Factor , Sequence Homology, Amino Acid , Transcriptional Activation , Xenopus/embryology , Xenopus/growth & development , Xenopus Proteins
6.
Breast Cancer Res Treat ; 61(2): 161-70, 2000 May.
Article in English | MEDLINE | ID: mdl-10942102

ABSTRACT

Infiltrating lobular carcinoma (ILC) and infiltrating ductal carcinoma (IDC) are similar in many respects and their histologic features occasionally overlap. Despite the many similarities, some clinical follow-up data and the patterns of metastasis suggest that ILC and IDC are biologically distinct. Unfortunately, most breast cancer research has focused almost exclusively on the ductal subtype or has not stressed the biologic or molecular genetic distinctions between breast carcinoma subtypes. Several reports have suggested the possibility that ILCs and IDCs differ with respect to expression of antigens involved in proliferation and cell cycle regulation. Therefore, we undertook an immunohistochemical evaluation of cell cycle related antigens in ILCs, including histologic variants thought to represent aggressive neoplasms, and IDCs matched for histologic grade (Modified Bloom-Richardson Grade I). We believe that different antigen expression profiles could elucidate the biological distinctiveness of breast carcinoma subtypes and possibly provide diagnostically relevant information. We studied the expression of the following antigens in 28 archived, formalin-fixed ILCs and 34 well-differentiated IDCs: estrogen receptor (ER), progesterone receptor (PR), Her 2-neu, mib-1, cyclin D1, p27, p53, mdm-2 and bcl-2. 94% of ILCs and 100% of IDCs expressed ER; 75% of ILCs and 76% of IDCs expressed PR; 4% of ILCs and 13% of IDCs expressed c cerb B-2; ILCs and IDCs both expressed mib-1 in approximately 10% of lesional cells; 82% of ILCs and 54% of IDCs expressed cyclin D1; 90% of ILCs and 83% IDCs expressed p27 strongly; 4% of ILCs and 4% of IDCs expressed p53, 25% of ILCs and 33% of IDCs expressed mdm-2; 96% of ILCs and 100% of IDCs expressed bcl-2. None of the apparent differences were statistically significant. The ILC variants demonstrated immunophenotypes that were essentially similar to ILCs of the usual type. We conclude that ILCs and well-differentiated IDCs show similar proliferation and cell cycle control antigen profiles. Despite their unusual histologic features, most ILC variants appear to maintain a characteristic ILC immunophenotype.


Subject(s)
Breast Neoplasms/chemistry , Carcinoma, Ductal, Breast/chemistry , Carcinoma, Lobular/chemistry , Cell Cycle Proteins/analysis , Cell Cycle , Neoplasm Proteins/analysis , Tumor Suppressor Proteins , Antigens, Neoplasm/analysis , Antigens, Nuclear , Biomarkers/analysis , Breast Neoplasms/pathology , Carcinoma, Ductal, Breast/pathology , Carcinoma, Lobular/pathology , Cohort Studies , Cyclin D1/analysis , Cyclin-Dependent Kinase Inhibitor p27 , Female , Humans , Immunophenotyping , Ki-67 Antigen , Microtubule-Associated Proteins/analysis , Neoplasm Invasiveness , Neoplasm Metastasis , Nuclear Proteins/analysis , Proto-Oncogene Proteins/analysis , Proto-Oncogene Proteins c-bcl-2/analysis , Proto-Oncogene Proteins c-mdm2 , Receptor, ErbB-2/analysis , Receptors, Estrogen/analysis , Receptors, Progesterone/analysis , Tumor Suppressor Protein p53/analysis
8.
Am J Health Syst Pharm ; 57(8): 753-5, 2000 Apr 15.
Article in English | MEDLINE | ID: mdl-10786261

ABSTRACT

An educational program designed to help physicians control the overall cost of drugs and total health care is described, along with its effectiveness at one managed health care plan. Prime Therapeutics, Inc., developed and manages an ongoing physician education program designed to help primary care physicians control drug and total health care costs. Physician education initiatives in the program are developed by using peer-reviewed literature; selections of preferred drugs are based on evidence of their safety, efficacy, uniqueness, and cost-effectiveness. For a typical educational initiative, a pharmacist meets with the physicians identified as being among the top 20% of prescribers of high-cost drugs addressed by the initiative and delivers a 20-minute presentation. One-on-one meetings with the physicians are then held quarterly to review their prescribing. Each physician is shown comparisons with the prescribing patterns of other physicians in the organization. The clinic chooses to present the clinicwide data as either blinded or nonblinded data. The program was evaluated by comparing per member per month (PMPM) total health care and drug costs for 1996 and 1997 at 12 general medicine clinics in a managed health care plan. Five clinics received no interventions, three clinics allowed the initial presentation and the quarterly face-to-face meetings, and four clinics allowed only the presentation and barred ongoing meetings. In general, the clinics with more interaction between pharmacists and physicians had lower PMPM costs for total health care and drugs than the clinics with less interaction. Pharmacists acting as advisers to primary care physicians in general medicine clinics helped lower PMPM costs for drugs and total health care.


Subject(s)
Managed Care Programs/standards , Pharmaceutical Preparations/economics , Pharmaceutical Services/organization & administration , Pharmacists , Physicians , Risk Sharing, Financial , Health Care Costs , Humans , Minnesota , Practice Patterns, Physicians'/economics , Program Evaluation
9.
J Urol ; 163(1): 52-5, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10604312

ABSTRACT

PURPOSE: We assessed the diagnostic accuracy of a ureteroscopic multi-biopsy approach to upper tract urothelial carcinoma compared with subsequently resected surgical specimens. MATERIALS AND METHODS: From 1990 to 1998, 45 upper tract lesions were ureteroscopically evaluated and biopsied with 3Fr cup forceps and/or an 11.5Fr resectoscope before nephroureterectomy or ureterectomy. A definitive diagnosis of urothelial carcinoma was made by biopsy in 40 lesions (89%). Each tumor was histopathologically graded but only staged if the lamina propria were uninvolved (Ta), and if the lamina propria were invaded by tumor (T1+). RESULTS: Of the 40 urothelial tumors 16 (40%) were in the renal pelvis, and 8 (20%) in the proximal and 16 (40%) in the distal ureter. Of the lesions 95% were papillary and 65% were grade 2. Ureteroscopic biopsy grade matched surgical pathological grade in 31 of the 40 cases (78%), and was less than surgical pathological grade in the remainder. Lamina propria was detected in 27 of the 40 biopsies, including 21 of the 34 cup (62%) and all 6 resection loop (100%) biopsies. Ureteroscopic biopsy staging in 27 cases revealed Ta and T1+ disease in 22 and 5, respectively. In the 5 cases in which ureteroscopic biopsy stage was T1+ surgical pathological stage was also pT1+ (range pT1 to pT3). Tumors were pathologically up staged to pT1+ (range pT1 to pT3) in 10 of the 22 cases (45%) in which ureteroscopic biopsy stage was Ta. Tumor location did not affect diagnostic accuracy. CONCLUSIONS: This multi-biopsy ureteroscopic approach provided the tissue diagnosis of urothelial carcinoma in 89% of cases and predicted exact histopathological grade in 78%. Although it is not accurate as a staging modality, multi-biopsy ureteroscopy may assess lamina propria invasion in two-thirds of cases.


Subject(s)
Carcinoma, Transitional Cell/pathology , Kidney Neoplasms/pathology , Kidney Pelvis , Ureteral Neoplasms/pathology , Ureteroscopy , Aged , Biopsy/methods , Female , Humans , Male , Neoplasm Staging , Reproducibility of Results
11.
Radiology ; 207(2): 545-50, 1998 May.
Article in English | MEDLINE | ID: mdl-9577508

ABSTRACT

A two-dimensional sonoelastographic technique called "disparity mapping" was applied to breast sonographic examinations in eight patients to test discrimination between benign and malignant lesions. With probe compression, pairs of gray-scale sonographic scans were obtained about 1 second apart. The disparity mapping procedure calculated the apparent displacement of the speckle pattern about each point in the image and presented that information in the form of a disparity map. Findings were consistent with a firm lesion in two of the three cancers, were indistinguishable from normal tissue in all three fibroadenomas, were indistinguishable from normal findings in one cyst, and showed no disparity in one cyst because it had few internal echoes.


Subject(s)
Breast Diseases/diagnostic imaging , Breast Neoplasms/diagnostic imaging , Image Processing, Computer-Assisted/methods , Ultrasonography, Mammary , Adult , Aged , Aged, 80 and over , Algorithms , Biopsy , Breast/pathology , Carcinoma, Ductal, Breast/diagnostic imaging , Data Display , Diagnosis, Differential , Elasticity , Female , Fibroadenoma/diagnostic imaging , Fibrocystic Breast Disease/diagnostic imaging , Follow-Up Studies , Hardness , Humans , Mammography , Middle Aged , Pressure , Videotape Recording
12.
J Cell Physiol ; 173(2): 115-8, 1997 Nov.
Article in English | MEDLINE | ID: mdl-9365505

ABSTRACT

The northern leopard frog, Rana pipiens, is vulnerable to a herpesvirus-induced renal tumor. The Lucké renal adenocarcinoma is metastatic as a function of temperature. The cloning procedure of nuclear transplantation has been used to study the differentiation potential of the tumor genome. This paper summarizes current studies of the pathology, virology, and differentiation competence of the Lucké tumor.


Subject(s)
Adenocarcinoma/veterinary , Kidney Neoplasms/veterinary , Rana pipiens , Animal Diseases/pathology , Animal Diseases/virology , Animals , Genome, Viral , Herpesvirus 1, Ranid/genetics
13.
Biochemistry ; 36(50): 15900-8, 1997 Dec 16.
Article in English | MEDLINE | ID: mdl-9398323

ABSTRACT

The replication Telomere Protein, rTP, is a nuclear protein from the ciliate Euplotes crassus that appears to be a novel telomere replication factor. rTP shares extensive amino acid sequence identity with the two proteins that bind and protect the macronuclear telomeres from the ciliates Oxytricha and Euplotes. Since the most extended regions of conservation fall within the DNA-binding domains of the telomere-binding proteins, when rTP was first identified it was predicted to be another structural telomere-binding protein. However, subsequent research demonstrated that rTP transcripts accumulate only during DNA replication and the rTP protein localizes to the sites of DNA replication within Euplotes macronuclei. We have now expressed rTP in a heterologous expression system and have examined the DNA-binding properties of the recombinant protein. We show that rTP binds specifically to the G-strand of Euplotes telomeric DNA and hence has some of the same DNA-binding characteristics as the Euplotes and Oxytricha telomere-binding proteins. However, other aspects of rTP binding are unique. In particular, the protein exhibits a very high off-rate and can bind double-stranded DNA as well as internal tracts of telomeric sequence. We conclude that rTP and the telomere-binding proteins are members of a class of proteins that have a conserved DNA-binding motif tailored to bind the G-strand of telomeric DNA. However, the unique DNA-binding characteristics of rTP indicate that the protein has evolved to fulfil a specialized role during telomere replication.


Subject(s)
DNA, Protozoan/metabolism , DNA-Binding Proteins/metabolism , Protozoan Proteins , Animals , Base Sequence , Binding, Competitive , Blotting, Western , Conserved Sequence/genetics , Deoxyribonucleotides/chemistry , Deoxyribonucleotides/metabolism , Euplotes/chemistry , Evolution, Molecular , Molecular Sequence Data , Oxytricha/chemistry , Recombinant Proteins/metabolism , Saccharomyces cerevisiae/genetics , Telomere/genetics , Telomere/metabolism
14.
Mayo Clin Proc ; 70(11): 1108-15, 1995 Nov.
Article in English | MEDLINE | ID: mdl-7475342

ABSTRACT

OBJECTIVE: To describe practical nonpharmacologic approaches to dementia-related behavioral problems for enhancement of the function and care of elderly patients with dementia. DESIGN: We reviewed the pertinent medical literature and summarized strategies and available resources for management of geriatric patients with dementia and behavior problems. RESULTS: For optimal care of older patients with dementia, key concepts of related behavior problems must be understood. Agitation and aggression, resisting help with care, wandering, incontinence, sleep disturbance, and emotional lability can become difficult management issues with such patients. In some patients, these disruptions can lead to overmedication and nursing home placement. Herein, practical nonpharmacologic measures for management of behavior problems that arise among community-dwelling and institutionalized elderly patients with dementia are discussed. Attention is directed to the medical, psychologic, environmental, and social factors that may contribute to unwanted behaviors. CONCLUSION: Nonpharmacologic approaches can help ameliorate behavioral problems and assist in the overall care of elderly patients with dementia.


Subject(s)
Dementia/complications , Mental Disorders/therapy , Humans , Mental Disorders/etiology
15.
J Comp Pathol ; 113(3): 277-86, 1995 Oct.
Article in English | MEDLINE | ID: mdl-8592053

ABSTRACT

The amphibian pronephros is fated to die during early development. Pronephric cells undergo apoptosis and their function is replaced by the mesonephros, which becomes the functional kidney of the adult frog. Tadpoles of the northern leopard frog, Rana pipiens, were inoculated with a Lucké tumour herpesvirus (LTV) preparation. Most of the animals developed typical Lucké renal carcinomas at metamorphosis. Fewer developed carcinomas of the pronephric cell type. A pronephric carcinoma, rescued from apoptosis by the herpesvirus, was harvested from a post-metamorphic frog. The tumour was judged to be pronephric by its anatomical location (in the anterior part of the body) and because both mesonephric kidneys were intact and tumour-free upon removal of the tumour mass. A tumour fragment was fixed for histological examination, which confirmed that the tissue was a renal carcinoma. A further fragment was subjected to short-term culture in order to produce metaphase cells for cytogenetical analysis. Based upon silverstained nucleolar organizing region numbers, 14 of 15 metaphase cells were estimated to have the diploid number (2N = 26) of chromosomes and a karyotype was constructed which did not appear to differ from that of normal cells. A single cell was estimated to be tetraploid (4N = 52). This is the first report of chromosomes of a pronephric Lucké carcinoma. LTV replicates only in tumour tissue maintained in the cold. Because the frog in this study had been maintained in the laboratory at 22 degrees C for about 10 months, no viruses would have been detectable with electron microscopy. However, the presence of Lucké herpesvirus DNA was detected in tumour homogenates by polymerase chain reaction amplification of a 1.2 kbp Hind III restriction fragment of the LTV DNA. The presence of LTV DNA provided assurance that the rescued pronephric tumour was indeed a Lucké carcinoma.


Subject(s)
Apoptosis , Chromosomes , Herpesviridae Infections/genetics , Herpesvirus 1, Ranid/physiology , Kidney Neoplasms/genetics , Tumor Virus Infections/genetics , Animals , Base Sequence , Herpesviridae Infections/pathology , Herpesviridae Infections/virology , Herpesvirus 1, Ranid/isolation & purification , Karyotyping , Kidney/growth & development , Kidney Neoplasms/pathology , Kidney Neoplasms/virology , Larva , Mesonephros , Molecular Probes/genetics , Molecular Sequence Data , Polymerase Chain Reaction , Rana pipiens , Tumor Virus Infections/pathology , Tumor Virus Infections/virology
16.
Biofactors ; 5(1): 29-37, 1995 May.
Article in English | MEDLINE | ID: mdl-7546216

ABSTRACT

We have demonstrated that the common soil bacterium, Bacillus subtilis, reduces selenite to an insoluble and much less toxic product--the red form of elemental selenium. Reduction was effected by an inducible system that appears to deposit elemental selenium between the cell wall and the plasma membrane. Glucose and sucrose supported selenite reduction. Although malate and citrate supported growth, no significant reduction of selenite occurred, indicating the importance of the redox state of the culture substrate. Selenite reduction in the millimolar concentration range (i.e., cultures supplemented with 1 mM selenite) was not affected by a ten-fold excess of nitrate or sulfate--compounds that serve as alternate electron acceptors and antagonize selenite reduction by anaerobic bacteria. Similarly, nitrite and sulfite did not significantly affect the rate or extent of selenite reduction. B.subtilis was able to grow and produce selenium (Se degree) at selenite concentrations ranging from 0.6 microM to 5 mM (50 ppb to 395 ppm selenium). At the lowest selenite concentration tested, 50 ppb selenium, B.subtilis removed 95% of the selenite from the liquid phase. The results suggest that selenite is reduced via an inducible detoxification system rather than dissimilatory electron transport. The findings establish the potential utility of B.subtilis for the bioremediation of selenite-polluted sites.


Subject(s)
Bacillus subtilis/metabolism , Selenium/metabolism , Sodium Selenite/metabolism , Bacillus subtilis/growth & development , Cell Membrane/metabolism , Cell Wall/metabolism , Citrates/pharmacology , Citric Acid , Culture Media , Glucose/pharmacology , Malates/pharmacology , Nitrates/pharmacology , Oxidation-Reduction , Sucrose/pharmacology , Sulfates/pharmacology
17.
Chromosoma ; 103(6): 414-22, 1994 Oct.
Article in English | MEDLINE | ID: mdl-7859562

ABSTRACT

We have previously reported that the replication origin region located near the ura4 gene on chromosome III of the fission yeast, Schizosaccharomyces pombe, contains three closely spaced origins, each associated with an autonomously replicating sequence (ARS) element. Here we report the nucleotide sequences of two of these ARS elements, ars3002 and ars3003. The two ARS elements are located on either side of a transcribed 1.5 kb open reading frame. Like 11 other S. pombe ARS elements whose sequences have previously been determined in other laboratories, the 2 new ARS elements are unusually A+T-rich. All 13 ARS elements contain easily unwound stretches of DNA. Each of the ARS elements contains numerous copies, at a higher than expected frequency, of short stretches of A+T-rich DNA in which most of the Ts are on one strand and most of the As are on the complementary strand. We discuss the potential significance for ARS function of these multiple asymmetric A+T-rich sequences.


Subject(s)
DNA Replication/genetics , Replication Origin/genetics , Schizosaccharomyces/genetics , Base Composition , Base Sequence , Chromosome Mapping , DNA, Fungal/genetics , Molecular Sequence Data , Oligodeoxyribonucleotides/genetics , Open Reading Frames/genetics , Plasmids/biosynthesis , Poly dA-dT/genetics , Sequence Analysis, DNA , Sequence Homology, Nucleic Acid , Transformation, Genetic
18.
J Comp Pathol ; 111(2): 197-204, 1994 Aug.
Article in English | MEDLINE | ID: mdl-7806705

ABSTRACT

The Lucké renal carcinoma of the northern leopard frog, Rana pipiens, has a herpesvirus aetiology. Lucké tumour nuclei inserted into enucleated frogs' eggs produce development to the swimming tadpole stage. Tissue from these tumour nuclear transplant animals can be induced to survive and differentiate further by allografting to normal tadpoles. We wished to ascertain whether the aetiological agent, the Lucké tumour herpesvirus (LTV), persists in the animals produced by tumour nuclear transplantation. The polymerase chain reaction was used to amplify a 1.2 kbp Hind III restriction fragment of LTV DNA in whole animal homogenates prepared from tumour nuclear transplant tadpoles and normal tadpoles fertilized in vitro. The LTV fragment was not present in the majority (31 of 34) of the cloned animals derived from tumour nuclei, nor was it present in any of five normal tadpoles. Either the 1.2 kbp fragment of LTV DNA was eliminated from most of the cloned animals during the massive reprogramming of the neoplastic genome initiated by insertion of the tumour nuclei into egg cytoplasm, or the nuclei selected for transplantation were primarily those lacking this fragment of LTV DNA. The limited development of the tumour nuclear tadpoles was probably not due to the presence of these viral sequences, but rather reflected the limited plasticity of the tumour cell genome as assayed by nuclear transplantation. Failure to detect the 1.2 kbp fragment of LTV DNA in the majority of mitotic progeny of the Lucké tumour genome does not imply that other parts of the viral genome do not persist.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
DNA, Viral/isolation & purification , Herpesviridae Infections/virology , Herpesvirus 1, Ranid/isolation & purification , Tumor Virus Infections/virology , Animals , Base Sequence , Clone Cells , Larva/virology , Molecular Sequence Data , Neoplasm Transplantation , Nuclear Transfer Techniques , Polymerase Chain Reaction , Rana pipiens
19.
EMBO J ; 13(15): 3638-47, 1994 Aug 01.
Article in English | MEDLINE | ID: mdl-8062838

ABSTRACT

The ura4 replication origin region, which is located near the ura4 gene on chromosome III of the fission yeast, Schizosaccharomyces pombe, contains multiple initiation sites. We have used 2D gel electrophoretic replicon mapping methods to study the distribution of these initiation sites, and have found that they are concentrated near three ARS elements (stretches of DNA which permit autonomous plasmid replication). To determine the roles of these ARS elements in the function of the ura4 origin region, we deleted either one or two of them from the chromosome and then assessed the consequences of the deletions by 2D gel electrophoresis. The results suggest that each of the three ARS elements is responsible for the initiation events in its vicinity and that the ARS elements interfere with each other in a hierarchical fashion. It is possible that the large initiation zones of animal cells are similarly composed of multiple mutually interfering origins.


Subject(s)
DNA Replication/genetics , Genes, Fungal/genetics , Regulatory Sequences, Nucleic Acid/genetics , Schizosaccharomyces/genetics , Chromosome Mapping , Chromosomes, Fungal , DNA Replication/physiology , DNA, Fungal/analysis , DNA, Fungal/chemistry , Electrophoresis, Gel, Two-Dimensional , Nucleic Acid Conformation , Sequence Deletion/physiology
20.
J Comp Pathol ; 110(4): 349-55, 1994 May.
Article in English | MEDLINE | ID: mdl-8056870

ABSTRACT

The Lucké tumour herpesvirus (LTV) is the aetiological agent of the Lucké renal adenocarcinoma of the northern leopard frog, Rana pipiens. LTV virions can be detected by electron microscopy in renal adenocarcinomata after prolonged exposure to low temperature. Tumours maintained at warm temperatures do not contain viral particles. To gain insight into the processes of viral infection, replication and oncogenesis, evidence was sought for the presence of LTV DNA in warm renal tumours and normal renal tissue. The polymerase chain reaction was used to amplify a Hind III restriction fragment of LTV DNA in tissue homogenates. LTV DNA was detected in a significant percentage of normal kidneys as well as in "virus-free" warm tumours and virus-containing cold tumours.


Subject(s)
DNA, Viral/analysis , Herpesviridae Infections/microbiology , Herpesvirus 1, Ranid/genetics , Kidney Neoplasms/microbiology , Kidney/microbiology , Tumor Virus Infections/microbiology , Adenocarcinoma/microbiology , Animals , Base Sequence , Electrophoresis, Agar Gel , Herpesvirus 1, Ranid/isolation & purification , Molecular Sequence Data , Polymerase Chain Reaction , Rana pipiens
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