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1.
Ann Oncol ; 29(2): 352-360, 2018 02 01.
Article in English | MEDLINE | ID: mdl-29069303

ABSTRACT

Background: Genomic aberrations have been identified in metastatic castration-resistant prostate cancer (mCRPC), but molecular predictors of resistance to abiraterone acetate/prednisone (AA/P) treatment are not known. Patients and methods: In a prospective clinical trial, mCRPC patients underwent whole-exome sequencing (n = 82) and RNA sequencing (n = 75) of metastatic biopsies before initiating AA/P with the objective of identifying genomic alterations associated with resistance to AA/P. Primary resistance was determined at 12 weeks of treatment using criteria for progression that included serum prostate-specific antigen measurement, bone and computerized tomography imaging and symptom assessments. Acquired resistance was determined using the end point of time to treatment change (TTTC), defined as time from enrollment until change in treatment from progressive disease. Associations of genomic and transcriptomic alterations with primary resistance were determined using logistic regression, Fisher's exact test, single and multivariate analyses. Cox regression models were utilized for determining association of genomic and transcriptomic alterations with TTTC. Results: At 12 weeks, 32 patients in the cohort had progressed (nonresponders). Median study follow-up was 32.1 months by which time 58 patients had switched treatments due to progression. Median TTTC was 10.1 months (interquartile range: 4.4-24.1). Genes in the Wnt/ß-catenin pathway were more frequently mutated and negative regulators of Wnt/ß-catenin signaling were more frequently deleted or displayed reduced mRNA expression in nonresponders. Additionally, mRNA expression of cell cycle regulatory genes was increased in nonresponders. In multivariate models, increased cell cycle proliferation scores (≥ 50) were associated with shorter TTTC (hazard ratio = 2.11, 95% confidence interval: 1.17-3.80; P = 0.01). Conclusions: Wnt/ß-catenin pathway activation and increased cell cycle progression scores can serve as molecular markers for predicting resistance to AA/P therapy.


Subject(s)
Abiraterone Acetate/administration & dosage , Drug Resistance, Neoplasm/genetics , Prednisone/administration & dosage , Prostatic Neoplasms, Castration-Resistant/genetics , Wnt Signaling Pathway/genetics , Aged , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Cell Cycle , Cell Proliferation , Genome-Wide Association Study , Humans , Male , Middle Aged , Neoplasm Metastasis/drug therapy , Neoplasm Metastasis/genetics , Prospective Studies , Prostatic Neoplasms, Castration-Resistant/drug therapy
3.
Prostate Cancer Prostatic Dis ; 16(4): 352-6, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23958895

ABSTRACT

BACKGROUND: It remains unclear whether the hemodilution effect of body mass index (BMI) on PSA levels translates to inappropriate prostate cancer (PCa) screening in obese men. To address this, we conducted two nested case-control studies within prospective cohorts of men undergoing radical prostatectomy for newly diagnosed PCa. METHODS: We identified 1817 men with BMI 30 kg m(-2) (cases) and 1244 men with BMI <25 kg m(-2) (controls) who underwent surgery to treat PCa at Mayo Clinic in Rochester between 2000 and 2009. Cases and controls were frequency matched on age and PSA level. In a similar manner, we identified 206 cases and 133 controls treated at Mayo Clinic in Florida between 2006 and 2011. We employed logistic regression models to evaluate the association of pathologic features of aggressiveness with obesity status. RESULTS: After adjusting for age and PSA level, we noted that obese men in the Rochester population are more likely to present with Gleason grade 8-10 tumors (OR= 1.50; 95% CI 1.14-1.96; P=0.003) and pT3, pT4, pTxN+ stage disease (OR=1.30; 95% CI 1.05-1.62). We noted a similar association seminal vesicle involvement (OR= 1.41; 95% CI 1.03-1.92; P=0.03). Results from the smaller Florida population supported these same associations but did not achieve conventional statistical significance. CONCLUSIONS: Obese men present with more aggressive PCa tumors compared with non-obese men of similar age and PSA screening values. If confirmed, this would support the need to explore PSA-based screening in obese men to possibly account for a hemodilution effect.


Subject(s)
Obesity/complications , Prostatic Neoplasms/complications , Prostatic Neoplasms/pathology , Age Factors , Aged , Aged, 80 and over , Body Mass Index , Case-Control Studies , Disease Progression , Humans , Male , Middle Aged , Neoplasm Staging , Prostate-Specific Antigen/metabolism , Prostatic Neoplasms/metabolism , Prostatic Neoplasms/surgery
4.
SAR QSAR Environ Res ; 17(4): 413-28, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16920662

ABSTRACT

Although the literature is replete with QSAR models developed for many toxic effects caused by reversible chemical interactions, the development of QSARs for the toxic effects of reactive chemicals lacks a consistent approach. While limitations exit, an appropriate starting-point for modeling reactive toxicity is the applicability of the general rules of organic chemical reactions and the association of these reactions to cellular targets of importance in toxicology. The identification of plausible "molecular initiating events" based on covalent reactions with nucleophiles in proteins and DNA provides the unifying concept for a framework for reactive toxicity. This paper outlines the proposed framework for reactive toxicity. Empirical measures of the chemical reactivity of xenobiotics with a model nucleophile (thiol) are used to simulate the relative rates at which a reactive chemical is likely to bind irreversibly to cellular targets. These measures of intrinsic reactivity serve as correlates to a variety of toxic effects; what's more they appear to be more appropriate endpoints for QSAR modeling than the toxicity endpoints themselves.


Subject(s)
Computational Biology/methods , Quantitative Structure-Activity Relationship , Toxicology/methods , Xenobiotics/chemistry , Xenobiotics/toxicity , Amino Acids/chemistry , Animals , Binding Sites , Computer Simulation , Hepatocytes/drug effects , Models, Chemical , Nucleic Acids/chemistry , Respiratory System/drug effects , Skin/drug effects , Sulfhydryl Compounds/chemistry , Tetrahymena pyriformis/drug effects
5.
J Lab Clin Med ; 136(2): 116-24, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10945240

ABSTRACT

Urinary monitoring of exposed workers by either analytic chemical methods or radioimmunoassay suggests that urinary levels of 2,4-dichlorophenoxyacetic acid (2,4-D) exceeding 30 ppb are indicative of occupational exposure. However, the current methods do not lend themselves to clinical laboratory use in the rural medical setting. The major goal of this project was to provide medical practitioners who care for members of the agricultural community with a cost-efficient way to conduct exposure assessment. This project used a direct 2,4-D enzyme immunoassay (EIA) and measurement of the ratio between 2,4-D-spiked and non-spiked samples of the same urine to quantify 2,4-D levels. This simplified approach minimizes the effects of non-specific interfering substances in urine and eliminates the need for sample extraction and clean-up. Possible urine co-contaminants (2,4-dichlorophenol and 2,5-dichlorophenol) do not significantly interfere with this immunoassay. Twenty-two forest pesticide applicators who apply and use chlorophenoxy herbicides in their work and 14 comparable control subjects were studied to validate the assay in the occupational setting. Coded urine specimens were examined for levels of 2,4-D by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and compared with immunoassay results from the same specimens. A correlation coefficient of r = 0.982 with a P value of .0001 for a plot of HPLC-MS/MS versus immunoassay demonstrated that the results from these methods were comparable over urinary dose levels ranging from not detectable (<19 ppb) to 1700 ppb 2,4-D, as determined by immunoassay.


Subject(s)
2,4-Dichlorophenoxyacetic Acid/immunology , 2,4-Dichlorophenoxyacetic Acid/urine , Immunoassay/methods , Adolescent , Adult , Aged , Aged, 80 and over , Child , Female , Humans , Male , Middle Aged , Sensitivity and Specificity
6.
Foot Ankle Int ; 21(1): 18-25, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10710257

ABSTRACT

We carried out an experiment to measure the relationship between tensile force in the tendoachilles and plantar fascia strain, and how this relationship is affected by the metatarsophalangeal joint dorsiflexion angle. Eight cadaver lower extremity specimens underwent biomechanical testing. Using a servo-hydraulic testing machine, a tensile force up to 500 N was applied to the tendoachilles while the strain on the plantar fascia was measured using an extensometer. The experiment was repeated at four different metatarsophalangeal joint dorsiflexion angles (0 degrees, 5 degrees, 30 degrees, and 45 degrees). Measurements and calculations showed that dorsiflexion of the toes tightens the plantar fascia (the windlass effect) and increases the effect that a tensile force in the tendoachilles has on the tensile strain and tensile force in the plantar fascia.


Subject(s)
Achilles Tendon/physiology , Fascia/physiology , Metatarsophalangeal Joint/physiology , Aged , Biomechanical Phenomena , Cadaver , Humans , Mathematics , Middle Aged , Models, Biological , Pliability , Research Design , Toes/physiology
7.
Foot Ankle Int ; 20(12): 762-70, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10609703

ABSTRACT

During a 12-year period in which 878 hallux valgus corrections were performed, 18 patients (21 feet) with symptomatic hallux valgus deformity and an increased distal metatarsal articular angle (DMAA) underwent periarticular osteotomies (double or triple first ray osteotomies). They were studied retrospectively at an average follow-up of 33 months. The surgical technique comprised a closing wedge distal first metatarsal osteotomy combined with either a proximal first metatarsal osteotomy or an opening wedge cuneiform osteotomy (double osteotomy). When a phalangeal osteotomy was added, the procedure was termed a "triple osteotomy." The average age of the patients at the time of surgery was 26 years. At final follow-up, the average hallux valgus correction measured 23 degrees and the average 1-2 intermetatarsal angle correction was 9 degrees. The DMAA averaged 23 degrees preoperatively and was corrected to an average of 9 degrees postoperatively. One patient developed a postoperative hallux varus deformity, and one patient developed a malunion, both of which required a second surgery. A hallux valgus deformity with an increased DMAA can be successfully treated with multiple first ray osteotomies that maintain articular congruity of the first metatarsophalangeal joint.


Subject(s)
Foot Bones/surgery , Hallux Valgus/pathology , Hallux Valgus/surgery , Metatarsal Bones/pathology , Metatarsal Bones/surgery , Osteotomy/methods , Adolescent , Adult , Aged , Child , Female , Follow-Up Studies , Hallux Valgus/physiopathology , Humans , Male , Metatarsophalangeal Joint/pathology , Metatarsophalangeal Joint/physiopathology , Middle Aged , Osteotomy/adverse effects , Patient Satisfaction , Retrospective Studies
8.
Chemosphere ; 34(5-7): 915-28, 1997.
Article in English | MEDLINE | ID: mdl-9134667

ABSTRACT

A simple and easy to use system has been developed for rapid screening of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) in a variety of situations. The system uses a competitive inhibition Enzyme ImmunoAssay (EIA) based on a previously described mouse monoclonal antibody which is specific for 2,3,7,8-TCDD and related congeners. Two formats have been developed, a rapid tube test and a microplate test. Respective sensitivities are 100 pg/tube and 25 pg/well of 2,3,7,8-TCDD. Congener specificity of the tube test roughly correlates with 1-TEF. The concept of TEQ screening is validated by comparing TEQ values for a set of soil samples to the EIA responses predicted for those samples. Actual analysis of crude extracts of some of the same soils indicated some clean-up is required to remove interferences. Rapid extraction and sample clean-up methods for soil and other matrices are being developed. Potential implementation of the EIA in a fixed lab is discussed. The EIA system offers significant improvements in speed, sample throughput, and cost compared to GC-MS. This system should be useful for screening environmental samples in many situations.


Subject(s)
Dioxins/toxicity , Furans/toxicity , Immunoenzyme Techniques , Polychlorinated Dibenzodioxins/toxicity , Toxicity Tests , Sensitivity and Specificity , Soil Pollutants/toxicity
9.
Anal Chem ; 67(21): 3829-39, 1995 Nov 01.
Article in English | MEDLINE | ID: mdl-8633754

ABSTRACT

Polychlorinated biphenyls (PCBs) are ubiquitous environmental pollutants with diverse toxic, teratogenic, reproductive, immunotoxic, and tumorigenic effects. Three of the least abundant of the 209 PCB isomers (congeners) are the most toxic and most difficult to quantify. These are 3,4,3',4'-tetrachlorobiphenyl, 3,4,3',4',5'-pentachlorobiphenyl, and 3,4,5,3',4',5'-hexachlorobiphenyl (IU-PAC No. 77, 126, and 169, respectively). An immunizing hapten was designed to retain the 3,4,3',4' chlorine-substitution pattern and coplanarity characteristic of these toxic congeners. The optimal competitors for immunoassay were weaker binding distinctive single-ring fragments of the PCBs. A monoclonal antibody designated S2B1 was derived and used in direct (antibody-capture) competitive enzyme immunoassays (EIAs). The EIAs are highly specific for non-ortho-substituted congeners and do not recognize the more prevalent but much less toxic noncoplanar PCB congeners or 2,3,7,8-tetrachlorodibenzo-p-dioxin, 2,3,7,8-tetrachlorodibenzofuran, or dichlorobenzenes. Hapten and competitor design for this assay suggests a basis for development of sensitive EIAs for other classes of PCB congeners.


Subject(s)
Antibodies, Monoclonal/immunology , Polychlorinated Biphenyls/analysis , Animals , Binding, Competitive , Cells, Cultured , Cross Reactions , Haptens/chemistry , Hybridomas , Immunoenzyme Techniques , Mice , Polychlorinated Biphenyls/metabolism
10.
Am J Physiol ; 262(3 Pt 2): H641-8, 1992 Mar.
Article in English | MEDLINE | ID: mdl-1558171

ABSTRACT

The contribution of myocardial edema to the no-reflow phenomenon, left ventricular functional recovery, and infarct size after coronary occlusion and reperfusion is uncertain. To examine this, we studied 26 open-chest dogs after coronary occlusion and reperfusion. Twelve dogs received hypertonic mannitol 30 min before reperfusion, which increased serum osmolality (P less than 0.01 vs. control). Fourteen control dogs received a similar volume of saline that had no effect on serum osmolality. Tissue biopsies of central ischemic and normal myocardial areas were analyzed by proton nuclear magnetic resonance relaxation spectroscopy to assess edema content. Hypertonic mannitol resulted in a significant decrease in ischemic tissue T1 (767.0 +/- 16.3 vs. 818.6 +/- 19.0 ms, P less than 0.05) compared with the control group. Despite this, no significant differences were found between the mannitol and control groups in 4-h reperfusion subendocardial blood flow or left ventricular wall thickening. In addition, mannitol administered before reperfusion did not modify infarct size compared with the control group (infarct/risk area, 41.0 +/- 1.4 vs. 37.9 +/- 1.9%, P not significant). In conclusion, no benefit is produced in reperfusion blood flow or functional recovery by reducing edema in postischemic myocardial tissue. This suggests that mechanisms other than myocardial edema are responsible for myocardial no reflow and contractile dysfunction after coronary reperfusion. Furthermore, hypertonic mannitol administered before reperfusion does not reduce infarct size.


Subject(s)
Coronary Circulation , Heart/physiopathology , Myocardial Infarction/physiopathology , Myocardial Reperfusion , Animals , Blood Pressure , Coronary Vessels/physiopathology , Dogs , Echocardiography , Edema , Heart/drug effects , Heart/physiology , Heart Rate , Heart Ventricles , Male , Mannitol/pharmacology , Time Factors
11.
Am Heart J ; 122(3 Pt 1): 655-64, 1991 Sep.
Article in English | MEDLINE | ID: mdl-1877442

ABSTRACT

To determine the distribution and extent of myocardial edema resulting from ischemia and reperfusion, seven open-chest dogs underwent occlusion of the left circumflex coronary artery for 2 hours (group I), and 10 underwent occlusion for 2 hours and reperfusion for 2 hours (group II). Proton nuclear magnetic resonance spectroscopy (T1 and T2 relaxation times) and percent water content were determined to quantitate the amount of edema. There was a transmural increase of the T1 relaxation time of the central ischemic zone in groups I and II, although this increase was significantly greater in group II in both the subendocardium (group I = 707.8 +/- 12.5 msec, group II = 813.2 +/- 36.2 msec; p less than 0.01) and subepicardium (group I = 641.7 +/- 20.5 msec, group II = 760.5 +/- 34.7 msec; p less than 0.01). These increases were also observed in the T2 weighted relaxation time in the subendocardium (group I = 54.7 +/- 0.8 msec, group II = 78.7 +/- 6.3 msec; p less than 0.005) and subepicardium (group I = 54.0 +/- 1.4 msec, group II = 73.1 +/- 4.0 msec; p less than 0.001). Transmural differences were evident between the myocardial layers with increased T1 relaxation times (p less than 0.01) in the subendocardium in both groups. Similar increases were noted in the percent water content of the myocardium. Thus T1 and T2 relaxation times lengthened with an increase in myocardial water content following occlusion, and these relaxation times were augmented by reperfusion. We conclude that ischemia-induced edema occurs in a transmural distribution from subendocardium to subepicardium following occlusion, and this edema is further enhanced by reperfusion.


Subject(s)
Magnetic Resonance Spectroscopy , Myocardial Reperfusion Injury/diagnosis , Myocardium/pathology , Animals , Dogs , Edema/diagnosis , Hemodynamics/physiology , Male , Myocardial Reperfusion Injury/physiopathology , Time Factors
12.
J Psychosoc Nurs Ment Health Serv ; 29(4): 28-32, 1991 Apr.
Article in English | MEDLINE | ID: mdl-2046071

ABSTRACT

1. Adult women who are survivors of incest can work on healing issues during long-term group therapy sessions. 2. Group therapy sessions can assist survivors to deal with unresolved family issues. 3. Group therapy sessions can be facilitated by psychiatric nurses who are college faculty when a nursing center is affiliated with a college of nursing.


Subject(s)
Family/psychology , Incest/psychology , Psychiatric Nursing/organization & administration , Psychotherapy, Group/organization & administration , Adult , Female , Humans , Incest/prevention & control , Incest/statistics & numerical data , Organizational Objectives , Outpatient Clinics, Hospital , Psychiatric Nursing/methods , Psychotherapy, Group/methods , Truth Disclosure
13.
Anticancer Res ; 10(3): 845-52, 1990.
Article in English | MEDLINE | ID: mdl-2369098

ABSTRACT

Antibody-drug conjugates containing a linkage susceptible to lysosomal hydrolases were constructed by coupling peptide-daunorubicin (DNR) derivatives to MAb. Using a modification in the method of Trouet et al, peptide derivatives of DNR containing the sequences Ala-Leu and Ala-Leu-Ala-Leu linked to drug via their carboxy terminus were prepared. Cleavage of these derivatives by lysosomal enzymes resulting in the release of free DNR was demonstrated. Human antitumor MAb were derivatized with either succinic anhydride or cis-aconitic anhydride to introduce spacer arms for coupling. Binding studies showed that MAb with a decrease of 12-20 amino groups retained greater than 70% of their immunoreactivity, a level deemed acceptable for constructing conjugates. Derivatized and native MAb were conjugated to peptide-DNR via a carbodiimide mediated reaction. None of the conjugates displayed cytotoxicity toward target tumor cell lines in vitro.


Subject(s)
Antibodies, Monoclonal/pharmacology , Daunorubicin/analogs & derivatives , Daunorubicin/pharmacology , Tumor Cells, Cultured/cytology , Aconitic Acid/analogs & derivatives , Amino Acid Sequence , Antibodies, Monoclonal/metabolism , Cell Line , Cell Survival/drug effects , Daunorubicin/chemical synthesis , Dipeptides , Flow Cytometry , Humans , Indicators and Reagents , Molecular Sequence Data , Oligopeptides , Protein Binding , Structure-Activity Relationship , Succinic Anhydrides , Tumor Cells, Cultured/drug effects
15.
J Am Coll Cardiol ; 14(7): 1803-13, 1989 Dec.
Article in English | MEDLINE | ID: mdl-2584572

ABSTRACT

Recent studies suggest that neutrophil accumulation and activation in postischemic myocardium may be responsible for myocardial no reflow, which is characterized by an incomplete restoration of blood flow after reperfusion. To examine this further, 11 open chest, anesthetized dogs received bolus injections of a bovine neutrophil antiserum that produced an average 81 +/- 5% depletion of circulating neutrophils, and 10 control dogs received nonimmune serum. Each animal underwent 2 h of left circumflex artery occlusion followed by 4 h of reperfusion. Simultaneous two-dimensional echocardiography and radioactive microsphere blood flow studies were performed at baseline, 2 h of occlusion and early (approximately 5 min) and 4 h of reperfusion. During occlusion, both groups developed similar reductions in myocardial blood flow and levels of ischemic zone myocardial wall thinning. At early reperfusion, similar levels of hyperemia and regional hypokinesia were observed for both groups. By late reperfusion, both groups experienced significant no reflow in the subendocardium (p less than 0.05) and reduced reflow in the mid-myocardium. Regional depression in ischemic zone function persisted throughout the reperfusion period in both groups. However, infarct size expressed as a percent of left ventricular weight, assessed by triphenyltetrazolium chloride staining, was smaller for the neutrophil depletion group compared with the control group (8.7 +/- 1.3% versus 13.1 +/- 1.8%, p less than 0.05). It is concluded that an 81% neutrophil depletion fails to modify the no reflow phenomenon or improve functional recovery after 2 h of coronary artery occlusion and 4 h of coronary reperfusion despite modification of the ultimate size of necrosis.


Subject(s)
Coronary Circulation , Myocardial Reperfusion , Neutrophils/physiology , Animals , Dogs , Echocardiography , Hemodynamics , Myocardial Infarction/pathology
16.
Am Heart J ; 116(2 Pt 1): 536-45, 1988 Aug.
Article in English | MEDLINE | ID: mdl-3400571

ABSTRACT

Myocardial ischemia may be produced by limitation of blood flow as in abrupt coronary occlusion, termed supply-type ischemia, or by increasing myocardial oxygen demand in the setting of restricted flow, termed demand-type ischemia. To examine the comparative extent and severity of the dysfunction related to both forms of ischemia, we studied anesthetized, open-chest dogs by means of two-dimensional echocardiography and tracer microspheres. Supply-type ischemia was produced by total occlusion of the LCx (n = 7); demand-type ischemia was induced by infusion of dobutamine after creation of a critical LCx stenosis (n = 6). At the time of the production of ischemia, the group with demand-type ischemia had significant increases in both heart rate (p less than 0.05) and mean arterial pressure (p less than 0.05), whereas the group with supply-type ischemia had a decrease in mean arterial pressure (p less than 0.05). Subendocardial blood flow in the LCx region was severely depressed in supply-type ischemia (0.09 +/- 0.04 ml/min/gm) compared to demand-type ischemia (1.04 +/- 0.07 ml/min/gm; p less than 0.01). Although both groups of animals had an abnormality of left ventricular function during ischemia, as determined by two-dimensional echocardiography, the extent of the dysfunction in the group with supply-type ischemia was greater (146 +/- 12 degrees) compared to the group with demand-type ischemia (99 +/- 9 degrees; p less than 0.01). Similarly, the degree of left ventricular dysfunction in the group with supply-type ischemia was greater than that for the group with demand-type ischemia (p less than 0.05). Thus these data suggest that supply-type ischemia produced by coronary occlusion results in a greater extent and degree of left ventricular functional abnormality than pharmacologically induced demand-type ischemia.


Subject(s)
Coronary Disease/physiopathology , Heart/physiopathology , Animals , Blood Pressure , Coronary Circulation , Coronary Disease/metabolism , Dogs , Echocardiography , Male , Myocardial Contraction , Myocardium/metabolism , Oxygen Consumption , Stroke Volume
18.
Can J Microbiol ; 32(1): 38-46, 1986 Jan.
Article in English | MEDLINE | ID: mdl-3697843

ABSTRACT

The 2nd year of a 2-year study of the fate of pentachlorophenol in outdoor artificial streams focused on details of microbial degradation by a combination of in situ and laboratory measurements. Replicate streams were dosed continuously at pentachlorophenol concentrations of 0, 48, and 144 micrograms/L, respectively, for an 88-d period during the summer of 1983. Pentachlorophenol was degraded both aerobically and anaerobically. Aerobic degradation was more rapid than anaerobic degradation. Mineralization of pentachlorophenol was concommitant with pentachlorophenol disappearance under aerobic conditions, but lagged behind loss of the parent molecule under anaerobic conditions. Biodegradation in the streams, or in specific stream compartments such as the sediment or water column, was characterized by an adaptation period (3-5 weeks for the stream as a whole, and reproducible from the previous year), which was inversely dependent on the concentration of pentachlorophenol and microbial biomass. The adaptation in the streams could be attributed to the time necessary for selective enrichment of an initially low population of pentachlorophenol degraders on surface compartments. The extent of biodegradation in the streams (percent loss of initial concentration of pentachlorophenol) increased with increasing pentachlorophenol input, which was explicable by an increase in the pentachlorophenol degrader population with increasing pentachlorophenol concentration. The sediment zone most significant to overall pentachlorophenol biodegradation was the top 0.5- to 1-cm layer as shown by pentachlorophenol migration rates and depth profiles of degrader density within the sediment. Pentachlorophenol profiles in sediment cores taken during and after the adaptation period for degradation showed that diffusion of pentachlorophenol into the sediment was rate limiting to degradation in this compartment.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Bacteria, Aerobic/metabolism , Bacteria, Anaerobic/metabolism , Chlorophenols/metabolism , Pentachlorophenol/metabolism , Water Microbiology , Water Pollutants, Chemical , Water Pollutants , Aerobiosis , Anaerobiosis , Biodegradation, Environmental , Temperature
19.
Appl Environ Microbiol ; 50(1): 127-32, 1985 Jul.
Article in English | MEDLINE | ID: mdl-4026288

ABSTRACT

Outdoor artificial streams were treated continuously with pentachlorophenol (PCP) for 88 days during the summer of 1983. The contributions of different stream compartments (microbial habitats) to microbial degradation of PCP were determined in a stream treated with 144 micrograms of PCP per liter. The 488-m long stream was composed of mud-bottomed pools alternating with gravel riffles. PCP loss in the stream attributable to microbial degradation after an adaptation period was in the range of 55 to 74%. Contributions to PCP loss were determined for rock surface (epilithic), macrophyte surface (epiphytic), sedimentary, and water column communities by measuring rates of PCP disappearance in stream water, containing ambient concentrations of PCP, in contact with representative compartmental samples. The specific capability, in units of micrograms of PCP per hour per square meter of stream cross-sectional area (macrophytes at maximum plant density, water column at mean depth, upper 10-cm layer of gravel), followed the order rock surface much greater than macrophytes greater than sediment approximately equal to water column. The compartmental contribution to total stream losses in units of grams per hour followed the same order, although the differences were smaller. The rate of PCP disappearance in the water column above sediment cores followed the order oxygen-rich greater than oxygen-poor approximately equal to anaerobic greater than sorption-only conditions. The large difference in specific capability between the rock surface and sediment compartments could be attributed to oxygen deficiency (because of chemical and biological oxygen demand) in the sediments. Free-floating and particle-attached organisms in the water column were important to PCP biodegradation.


Subject(s)
Chlorophenols/metabolism , Pentachlorophenol/metabolism , Water Microbiology , Water Pollutants, Chemical , Water Pollutants , Aerobiosis , Anaerobiosis , Biodegradation, Environmental/drug effects , Chromatography, Gas , Fresh Water , Oxygen/pharmacology , Soil Microbiology , Soil Pollutants
20.
Am J Ophthalmol ; 98(6): 717-22, 1984 Dec 15.
Article in English | MEDLINE | ID: mdl-6507543

ABSTRACT

Of 104 consecutive patients with senile reticular pigmentary degeneration (207 eyes), 85 patients (82%) were more than 60 years old (mean age, 69.2 +/- 8.54 years). Forty-nine (47%) were men and 55 (53%) were women. Peripheral visual fields were not characteristically constricted. Although most eyes tested had visual acuities of 20/50 or better, 69 eyes (33%) had visual acuities of 20/100 or worse. A total of 136 eyes (66%) had senile macular degeneration at the time senile reticular pigmentary degeneration was first diagnosed, whereas only 43 control eyes (21%) from the same referral population also had senile macular degeneration (P less than .001). Macular degeneration was the primary cause for reduced vision when it was noted. In no instance could reduced visual acuity or constricted visual fields be attributed to the senile reticular pigmentary degeneration alone. Senile reticular pigmentary degeneration on routine ophthalmoscopy should alert the clinician to the possibility of co-existing macular degenerative disease.


Subject(s)
Retinal Degeneration/diagnosis , Aged , Aging , Female , Fluorescein Angiography , Fundus Oculi , Humans , Male , Middle Aged , Pigment Epithelium of Eye/pathology , Visual Acuity , Visual Fields
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