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1.
BMC Public Health ; 23(1): 1697, 2023 09 02.
Article in English | MEDLINE | ID: mdl-37660119

ABSTRACT

BACKGROUND: Although physical activity interventions are frequently reported to be effective, long-term changes are needed to generate meaningful health benefits. There are criticisms that evaluations of physical activity interventions mostly report short-term outcomes and that these are often self-reported rather than measured objectively. This study therefore aimed to assess the long-term (at least 24 month) effectiveness of behavioural interventions on objectively measured physical activity. METHODS: We conducted a systematic review with a meta-analysis of effects on objectively measured physical activity. We searched: Cochrane CENTRAL, EMBASE, PsychInfo, CINAHL and Pubmed up to 10th January 2022. Studies were included if they were in English and included a physical intervention that assessed physical activity in the long-term (defined as at least 24 months). RESULTS: Eight studies with 8480 participants were identified with data suitable for meta-analysis. There was a significant effect of interventions on daily steps 24 months post baseline (four studies, SMD: 0.15, 95% CI: 0.02 to 0.28) with similar results at 36 to 48 months of follow up (four studies, SMD: 0.17, 95% CI: 0.07 to 0.27). There was a significant effect of interventions on moderate-to-vigorous physical activity 24 months post baseline (four studies, SMD: 0.18 95% CI: 0.07 to 0.29) and at 36 to 48 months (three studies, SMD: 0.16 95% CI: 0.09 to 0.23). The mean effect size was small. However, the changes in moderate-to-vigorous physical activity and steps per day were clinically meaningful in the best-performing studies. CONCLUSION: This review suggests that behavioural interventions can be effective in promoting small, but clinically meaningful increases in objectively measured physical activity for up to 48 months. There is therefore a need to develop interventions that can achieve greater increases in long-term physical activity with greater efficiency.


Subject(s)
Behavior Therapy , Exercise , Humans , Self Report
2.
Lett Appl Microbiol ; 63(6): 458-465, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27604045

ABSTRACT

Identification of populations of Aspergillus section Nigri species in environmental samples using traditional methods is laborious and impractical for large numbers of samples. We developed species-specific primers and probes for quantitative droplet digital PCR (ddPCR) to improve sample throughput and simultaneously detect multiple species in each sample. The ddPCR method was used to distinguish Aspergillus niger, Aspergillus welwitschiae, Aspergillus tubingensis and Aspergillus carbonarius in mixed samples of total DNA. Relative abundance of each species measured by ddPCR agreed with input ratios of template DNAs. Soil samples were collected at six time points over two growing seasons from two raisin vineyards in Fresno County, California. Aspergillus section Nigri strains were detected in these soils in the range of 102 -105  CFU g-1 . Relative abundance of each species varied widely among samples, but in 52 of 60 samples, A. niger was the most abundant species, ranging from 38 to 88% of the total population. In combination with total plate counts, this ddPCR method provides a high-throughput method for describing population dynamics of important potential mycotoxin-producing species in environmental samples. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study to demonstrate the utility of ddPCR as a means to quantify species of Aspergillus section Nigri in soil. This method eliminates the need for isolation and sequence identification of individual fungal isolates, and allows for greater throughput in measuring relative population sizes of important (i.e. mycotoxigenic) Aspergillus species within a population of morphologically indistinguishable species.


Subject(s)
Aspergillus/isolation & purification , Polymerase Chain Reaction/methods , Soil Microbiology , Vitis/growth & development , Aspergillus/classification , Aspergillus/genetics , Aspergillus/metabolism , California , DNA Primers/genetics , Farms , Mycotoxins/genetics , Mycotoxins/metabolism , Ochratoxins/metabolism , Species Specificity , Vitis/microbiology
3.
Equine Vet J ; 48(5): 543-7, 2016 Sep.
Article in English | MEDLINE | ID: mdl-26282863

ABSTRACT

REASONS FOR PERFORMING STUDY: Sesamoiditis is a common radiological finding in yearling Thoroughbreds. The condition is believed to be associated with suspensory ligament branch injury (SLBI), which is known to affect racing performance. The presence of subclinical suspensory ligament branch change (SSLBC) in untrained yearlings has not been investigated. Associations between sesamoiditis, SSLBC and subsequent SLBI would allow more accurate prognoses to be made regarding the development of SLBI. They could also provide opportunity for intervention and prevention of SLBI. OBJECTIVES: To test our hypotheses that untrained yearling Thoroughbreds with sesamoiditis would be more likely to have ultrasonographic findings of SSLBC and those horses with concurrent sesamoiditis and SSLBC would be more likely to develop clinical suspensory ligament branch injury with training. STUDY DESIGN: Prospective, cohort, observational study. METHODS: Yearling Thoroughbreds located at a single training centre were evaluated at the onset of their training careers and for the next 9 months. Radiographic and ultrasonographic examination of bilateral forelimb proximal sesamoid bones and suspensory ligament branches was performed. RESULTS: Fifty horses were eligible, resulting in 200 forelimb sesamoid/suspensory ligament branch pairs. A significant relationship existed between possibly significant (PS) sesamoiditis and PS SSLBC (P<0.001). The odds ratio of sesamoids with PS sesamoiditis also demonstrating concurrent PS SSLBC was 5.1 (95% confidence interval 2.68-9.70, P<0.001). A significant relationship also existed between the concurrent presence of PS sesamoiditis and PS SSLBC and the subsequent development of clinical signs of SLBI (P<0.001, odds ratio 11.7, 95% confidence interval 4.1-33.4). CONCLUSIONS: The associations identified in this study highlight the importance of ultrasonographic examination of suspensory ligament branches in horses with PS sesamoiditis. This information should allow more accurate prognostic advice regarding potential SLBI development and also provide opportunities for intervention and prevention of clinical SLBI. THE SUMMARY IS AVAILABLE IN CHINESE - SEE SUPPORTING INFORMATION.


Subject(s)
Horse Diseases/diagnostic imaging , Horses/injuries , Ligaments/injuries , Sesamoid Bones/injuries , Aging , Animals , Cohort Studies , Female , Ligaments/diagnostic imaging , Male , Prospective Studies , Sesamoid Bones/diagnostic imaging
4.
Lett Appl Microbiol ; 60(2): 188-195, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25384730

ABSTRACT

Species of Aspergillus section Nigri are not easily distinguished by traditional morphological techniques, and typically are identified by DNA sequencing methods. We developed four PCR primers to distinguish between Aspergillus niger, Aspergillus welwitschiae, Aspergillus carbonarius and Aspergillus tubingensis, based on species-conserved differences in the calmodulin gene sequence. PCR amplification from total DNA using these primers was species specific; no amplification occurred from nontarget species DNA for each primer pair. Species-specific PCR could distinguish between species in mixed DNA templates, indicating a utility in determining culture uniformity of isolated Aspergillus strains. In addition, with these primer sets, each species could be detected in soil following mixed-species inoculation with Aspergillus spores. This indicates that PCR with these species-specific primers may be useful in determining the distribution of Aspergillus species in environmental samples without the need for species identification from isolated strains, as well as detecting species that may be infrequently isolated by culture-based methods.


Subject(s)
Aspergillus niger/isolation & purification , Aspergillus/isolation & purification , Polymerase Chain Reaction/methods , Aspergillus/classification , Aspergillus/genetics , Aspergillus niger/classification , Aspergillus niger/genetics , Calmodulin/genetics , DNA Primers , Genes, Fungal , Sequence Analysis, DNA , Soil Microbiology , Species Specificity
5.
Eur J Trauma Emerg Surg ; 40(5): 567-72, 2014 Oct.
Article in English | MEDLINE | ID: mdl-26814513

ABSTRACT

INTRODUCTION: Multiple studies have demonstrated a linear association between advancing age and mortality after injury. An inflection point, or an age at which outcomes begin to differ, has not been previously described. We hypothesized that the relationship between age and mortality after injury is non-linear and an inflection point exists. METHODS: We performed a retrospective cohort analysis at our urban level I center from 2007 through 2009. All patients aged 65 years and older with the admission diagnosis of injury were included. Non-parametric logistic regression was used to identify the functional form between mortality and age. Multivariate logistic regression was utilized to explore the association between age and mortality. Age 65 years was used as the reference. Significance was defined as p < 0.05. RESULTS: A total of 1,107 patients were included in the analysis. One-third required intensive care unit (ICU) admission and 48 % had traumatic brain injury. 229 patients (20.6 %) were 84 years of age or older. The overall mortality was 7.2 %. Our model indicates that mortality is a quadratic function of age. After controlling for confounders, age is associated with mortality with a regression coefficient of 1.08 for the linear term (p = 0.02) and a regression coefficient of -0.006 for the quadratic term (p = 0.03). The model identified 84.4 years of age as the inflection point at which mortality rates begin to decline. CONCLUSIONS: The risk of death after injury varies linearly with age until 84 years. After 84 years of age, the mortality rates decline. These findings may reflect the varying severity of comorbidities and differences in baseline functional status in elderly trauma patients. Specifically, a proportion of our injured patient population less than 84 years old may be more frail, contributing to increased mortality after trauma, whereas a larger proportion of our injured patients over 84 years old, by virtue of reaching this advanced age, may, in fact, be less frail, contributing to less risk of death.

7.
Eur J Trauma Emerg Surg ; 40(6): 729-32, 2014 Dec.
Article in English | MEDLINE | ID: mdl-26814790

ABSTRACT

INTRODUCTION: Traumatic brain injury is a leading cause of disability in bicycle riders. Preventive measures including bicycle helmet laws have been highlighted; however, its protective role has always been debated. The aim of this study was to determine the utility of bicycle helmets in prevention of intra-cranial hemorrhage. We hypothesized that bicycle helmets are protective and prevent the development of intra-cranial hemorrhage. METHODS: We performed a 4-year (2009-2012) retrospective cohort analysis of all the patients who presented with traumatic brain injury due to bicycle injuries to our level 1 trauma center. We compared helmeted and non-helmeted bicycle riders for differences in the patterns of injury, need for intensive care unit admissions and mortality. RESULTS: A total of 864 patients were reviewed of which, 709 patients (helmeted = 300, non-helmeted = 409) were included. Non-helmeted bicycle riders were more likely to be young (p < 0.001) males (p = 0.01). There was no difference in the median ISS between the two groups (p = 0.3). Non-helmeted riders were more likely to have a skull fracture (p = 0.01) and a scalp laceration (p = 0.01) compared to the helmeted riders. There was no difference in intra-cranial hemorrhage between the two groups (p = 0.1). Wearing a bicycle helmet was not independently associated (p = 0.1) with development of intra-cranial hemorrhage. CONCLUSION: Bicycle helmets may have a protective effect against external head injury but its protective role for intra-cranial hemorrhage is questionable. Further studies assessing the protective role of helmets for intra-cranial hemorrhage are warranted.

8.
Br J Surg ; 101(2): 17-22, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24375295

ABSTRACT

BACKGROUND: Small pigtail catheters appear to work as well as the traditional large-bore chest tubes in patients with traumatic pneumothorax, but it is not known whether the smaller pigtail catheters are associated with less tube-site pain. This study was conducted to compare tube-site pain following pigtail catheter or chest tube insertion in patients with uncomplicated traumatic pneumothorax. METHODS: This prospective randomized trial compared 14-Fr pigtail catheters and 28-Fr chest tubes in patients with traumatic pneumothorax presenting to a level I trauma centre from July 2010 to February 2012. Patients who required emergency tube placement, those who refused and those who could not respond to pain assessment were excluded. Primary outcomes were tube-site pain, as assessed by a numerical rating scale, and total pain medication use. Secondary outcomes included the success rate of pneumothorax resolution and insertion-related complications. RESULTS: Forty patients were enrolled. Baseline characteristics of 20 patients in the pigtail catheter group were similar to those of 20 patients in the chest tube group. No patient had a flail chest or haemothorax. Pain scores related to chest wall trauma were similar in the two groups. Patients with a pigtail catheter had significantly lower mean(s.d.) tube-site pain scores than those with a chest tube, at baseline after tube insertion (3.2(0.6) versus 7.7(0.6); P < 0.001), on day 1 (1.9(0.5) versus 6.2(0.7); P < 0.001) and day 2 (2.1(1.1) versus 5.5(1.0); P = 0.040). The decreased use of pain medication associated with pigtail catheter was not significantly different. The duration of tube insertion, success rate and insertion-related complications were all similar in the two groups. CONCLUSION: For patients with a simple, uncomplicated traumatic pneumothorax, use of a 14-Fr pigtail catheter is associated with reduced pain at the site of insertion, with no other clinically important differences noted compared with chest tubes. REGISTRATION NUMBER: NCT01537289 (http://clinicaltrials.gov).


Subject(s)
Catheterization/adverse effects , Chest Tubes/adverse effects , Pain/prevention & control , Pneumothorax/therapy , Thoracic Injuries/therapy , Analgesics/therapeutic use , Female , Humans , Male , Middle Aged , Pain/etiology , Pain Measurement , Prospective Studies , Treatment Outcome
9.
World J Surg ; 36(3): 516-23, 2012 Mar.
Article in English | MEDLINE | ID: mdl-21976011

ABSTRACT

Damage-control surgery and open-abdomen is an acceptable­and often lifesaving­approach to the treatment of patients with severe trauma, abdominal compartment syndrome, necrotizing soft tissue catastrophes, and other abdominal disasters, when closing the abdomen is not possible, ill advised, or will have serious sequelae. However, common consequences of open-abdomen management include large abdominal wall defects, enterocutaneous fistulas (ECFs), and enteroatmospheric fistulas (EAFs). Furthermore, in such patients, a frozen and hostile abdomen (alone or combined with ECFs) is not uncommon. Adding biologic mesh to our surgical armamentarium has revolutionized hernia surgery.


Subject(s)
Digestive System Surgical Procedures , Hernia, Abdominal/surgery , Intestinal Fistula/surgery , Anastomosis, Surgical/methods , Humans , Plastic Surgery Procedures , Reoperation/methods , Surgical Mesh
10.
Eur J Trauma Emerg Surg ; 37(2): 169-75, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21837258

ABSTRACT

OBJECTIVE: To determine the injury patterns, complications, and mortality after alcohol consumption in trauma patients. METHODS: The Trauma Registry at an American College of Surgeons (ACS) level I center was queried for all patients with a toxicology screen admitted between 1st January 2002 and 31st December 2005. Alcohol-positive (AP) patients were matched to control patients who had a completely negative screen (AN) using age, gender, mechanism, Injury Severity Score (ISS), head Abbreviated Injury Scale (AIS), chest AIS, abdominal AIS, and extremity AIS. Injuries and outcomes were compared between the groups. RESULTS: As many as 5,317 patients had toxicology data, of which 471 (8.9%) had a positive alcohol screen (AP). A total of 386 AP patients were then matched to 386 control (AN) patients. The AP group had a significantly higher mortality than the AN group overall (23 vs. 13%; p < 0.001), and by ISS stratification: ISS < 16 (6 vs. 0.4%; p < 0.001), ISS 16-25 (53 vs. 28%; p = 0.01), and ISS > 25 (90 vs. 67%; p = 0.01). AP patients had a higher incidence of admission systolic blood pressure < 90 (18 vs. 10%; p < 0.001) and Glasgow Coma Scale (GCS) score ≤ 8 (25 vs. 17%; p = 0.002). AN patients had a significantly higher incidence of hemopneumothorax (11 vs. 7%; p = 0.03), while AP patients had a higher incidence of cardiac arrest (8 vs. 3%; p = 0.004). There was no difference in intensive care unit (ICU) and hospital length of stay. CONCLUSION: In a mixed population of trauma patients, an AP screen is associated with an increased incidence of admission hypotension and depressed GCS score. In this case-matched study, alcohol exposure appeared to increase mortality after injury.

11.
Lett Appl Microbiol ; 52(4): 330-6, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21214608

ABSTRACT

AIMS: To determine incidence and levels of ochratoxin A (OTA) in California raisins and to isolate and characterize OTA-producing fungi from California raisin vineyard populations. METHODS AND RESULTS: Forty raisin clusters sampled from four California vineyards in the San Joaquin Valley were analysed for OTA content using immunoaffinity and HPLC methods. OTA was detected in 93% of the samples, at levels from 0·06 to 11·4 ng g⁻¹. From these raisin samples, a total of 400 strains of Aspergillus were isolated and analysed for OTA production. Twelve isolates (3%), from five raisin samples, produced OTA. These isolates were identified as Aspergillus carbonarius, based on morphological characteristics and multilocus sequence analysis. Levels of OTA produced by these isolates on raisin agar ranged from 0·9 to 15 µg g⁻¹. CONCLUSIONS: OTA is a common contaminant of raisin vineyards, but average levels are much lower than EU regulatory limits for dried fruit. The primary species responsible for OTA contamination in California raisins is A. carbonarius. SIGNIFICANCE AND IMPACT OF THE STUDY: This study illustrates that low-level OTA contamination of raisins occurs in California and that ecological studies of A. carbonarius within the Aspergillus section Nigri population on raisins are warranted to monitor ochratoxigenic potential of the crop.


Subject(s)
Aspergillus/isolation & purification , Ochratoxins/biosynthesis , Vitis/microbiology , Aspergillus/classification , Aspergillus/metabolism , California , Multilocus Sequence Typing
12.
Acta Chir Belg ; 108(2): 212-8, 2008.
Article in English | MEDLINE | ID: mdl-18557146

ABSTRACT

PURPOSE: The purpose of this study is to report results from a survey of members of the American Association for the Surgery of Trauma (AAST) on strategies for management of the open abdomen. MATERIAL AND METHODS: Invitations to participate in a web-based survey were sent to AAST members via email. MAIN RESULTS: The response rate was 26%. For 74% of surgeons surveyed, the number of cases treated per year has increased over the last 10 years. The abdomen is left open for damage control (46% of respondents) and abdominal organ distention (22%). Most respondents use the vacuum pack system to temporarily close the abdomen (57%) and a smaller proportion use a bogota bag (18%). Ventilatory failure was the most frequent complication (72%) and elderly patients have the worse outcome. SIGNIFICANT CONCLUSIONS: Given the lack of consensus regarding optimal management strategies for the open abdomen, there is a need for prospective, multi-institutional studies to evaluate therapeutic approaches to treat this challenging problem.


Subject(s)
Abdominal Injuries/surgery , Abdominal Wall/surgery , Attitude of Health Personnel , Decision Making , Health Care Surveys , Humans
13.
Mol Microbiol ; 39(4): 982-93, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11251818

ABSTRACT

Lacticin 3147 is a membrane-active, two-component lantibiotic produced by Lactococcus lactis ssp. lactis DPC3147. In this study, the promoters of the lacticin 3147 gene cluster were mapped to the intergenic region between ltnR and ltnA1 (the genes encoding the regulatory protein LtnR and the first structural gene, LtnA1), and Northern analyses revealed that the biosynthetic and immunity genes are divergently transcribed in two operons, ltnA1A2M1TM2D and ltnRIFE respectively. Although the promoter controlling biosynthesis (Pbac) appears to be constitutive, characterization of a downstream beta-galactosidase (beta-gal) fusion beyond an intragenic stem-loop structure in ltnM1 confirmed that this putative transcriptional attenuator allows limited readthrough to the downstream biosynthetic genes, thus maintaining the correct stoichiometry between structural peptides and biosynthetic machinery. The promoter of the ltnRIFE operon (Pimm) was shown to be regulated by the transcriptional repressor LtnR. A mutant with a truncated ltnR gene exhibited a hyperimmune phenotype, whereas overexpression of ltnR resulted in cells with increased sensitivity to lacticin 3147. Gel mobility shift analysis indicated that LtnR binds to the Pimm promoter region, and fusion of this promoter to the beta-gal gene of pAK80 revealed that expression from Pimm is significantly reduced in the presence of LtnR. Thus, we have demonstrated that lacticin 3147 uses a regulatory mechanism not previously identified in lantibiotic systems.


Subject(s)
Anti-Bacterial Agents , Bacterial Proteins/genetics , Bacteriocins , Gene Expression Regulation, Bacterial , Lactococcus lactis/genetics , Repressor Proteins/metabolism , Transcription, Genetic , Bacterial Proteins/immunology , Base Sequence , Genes, Bacterial , Lactococcus lactis/immunology , Molecular Sequence Data , Multigene Family , Promoter Regions, Genetic , Repressor Proteins/genetics
14.
Appl Environ Microbiol ; 65(4): 1506-15, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10103244

ABSTRACT

Enterocin A is a small, heat-stable, antilisterial bacteriocin produced by Enterococcus faecium DPC1146. The sequence of a 10, 879-bp chromosomal region containing at least 12 open reading frames (ORFs), 7 of which are predicted to play a role in enterocin biosynthesis, is presented. The genes entA, entI, and entF encode the enterocin A prepeptide, the putative immunity protein, and the induction factor prepeptide, respectively. The deduced proteins EntK and EntR resemble the histidine kinase and response regulator proteins of two-component signal transducing systems of the AgrC-AgrA type. The predicted proteins EntT and EntD are homologous to ABC (ATP-binding cassette) transporters and accessory factors, respectively, of several other bacteriocin systems and to proteins implicated in the signal-sequence-independent export of Escherichia coli hemolysin A. Immediately downstream of the entT and entD genes are two ORFs, the product of one of which, ORF4, is very similar to the product of the yteI gene of Bacillus subtilis and to E. coli protease IV, a signal peptide peptidase known to be involved in outer membrane lipoprotein export. Another potential bacteriocin is encoded in the opposite direction to the other genes in the enterocin cluster. This putative bacteriocin-like peptide is similar to LafX, one of the components of the lactacin F complex. A deletion which included one of two direct repeats upstream of the entA gene abolished enterocin A activity, immunity, and ability to induce bacteriocin production. Transposon insertion upstream of the entF gene also had the same effect, but this mutant could be complemented by exogenously supplied induction factor. The putative EntI peptide was shown to be involved in the immunity to enterocin A. Cloning of a 10.5-kb amplicon comprising all predicted ORFs and regulatory regions resulted in heterologous production of enterocin A and induction factor in Enterococcus faecalis, while a four-gene construct (entAITD) under the control of a constitutive promoter resulted in heterologous enterocin A production in both E. faecalis and Lactococcus lactis.


Subject(s)
Bacteriocins/biosynthesis , Enterococcus faecium/genetics , Enterococcus faecium/metabolism , Gene Expression Regulation, Bacterial , Operon/genetics , Amino Acid Sequence , Bacterial Proteins/biosynthesis , Bacterial Proteins/genetics , Bacteriocins/genetics , Enterococcus faecium/immunology , Genes, Bacterial , Molecular Sequence Data , Multigene Family , Open Reading Frames/genetics , Polymerase Chain Reaction/methods , Sequence Alignment , Sequence Analysis, DNA , Signal Transduction
15.
FEMS Microbiol Lett ; 173(1): 265-71, 1999 Apr 01.
Article in English | MEDLINE | ID: mdl-10220904

ABSTRACT

Enterococcus faecium DPC3675 is a derivative of E. faecium DPC1146 which contains a single copy of the conjugative transposon Tn916. Although the transposon is observed to be oriented in one direction in individual colonies, DNA extracted from cultures grown from these colonies contains the transposon in both orientations, as determined by PCR analysis and sequencing of the transposon/chromosome junctions. Therefore, Tn916 possesses a hitherto unreported ability to invert within a particular insertion site during growth in broth.


Subject(s)
Conjugation, Genetic , DNA Transposable Elements , Enterococcus faecium/genetics , Base Sequence , DNA, Bacterial , Enterococcus faecium/growth & development , Mutagenesis, Insertional , Sequence Analysis, DNA
16.
Anal Chem ; 69(17): 3595-602, 1997 Sep 01.
Article in English | MEDLINE | ID: mdl-9286165

ABSTRACT

Toward a goal of dideoxy sequencing DNA utilizing electrophore labels, we prepared four electrophore-labeled DNA oligonucleotide primers. Each primer has a different electrophore and DNA sequence but a common glycol keto (alpha,beta-dihydroxyketo) release group. Cleavage of this latter group by either periodate oxidation or a thermal retroaldol reaction releases the electrophores for detection by mass spectrometry. Successful sequencing data with these primers was obtained by capillary electrophoresis on an ABI Model 310 after fluorescence dideoxy terminator cycle sequencing reactions were conducted. In a separate experiment, it was demonstrated that a cocktail of the four electrophore DNA primers could be detected as a dried sample spot by CO2 laser desorption/capillary collection/gas chromatography electron capture mass spectrometry. These results establish some feasibility for our long-term goal of high-speed multiplex electrophore mass tag dideoxy DNA sequencing. Ultimately we plan to use a higher number of electrophore mass tags and to rely on direct detection of the desorbed electrophores by electron capture time-of-flight mass spectrometry.


Subject(s)
DNA Primers/chemical synthesis , DNA/chemistry , Sequence Analysis, DNA/methods , Chromatography, High Pressure Liquid , DNA/isolation & purification , Electrochemistry , Electrophoresis , Mass Spectrometry
17.
J Occup Environ Med ; 38(12): 1253-8, 1996 Dec.
Article in English | MEDLINE | ID: mdl-8978517

ABSTRACT

A retrospective cohort study evaluated the risk of lung cancer in aerospace workers with minimum of 6 months' employment in jobs with chromium [VI] exposure (n = 2429). Standardized incidence ratios (SIR) estimated the risk of lung cancer by duration of employment in chromate-exposure jobs and cumulative exposure based on industrial hygiene and work-history data. The overall SIR for lung cancer was 0.8 (observed [Obs] = 15). Lung cancer risk was inversely related to estimates of cumulative chromate exposure and duration of employment as a painter. Although based on few cases, an elevated lung cancer risk was found in subjects who had worked for 5 or more years as a chrome plater or surface processor tank tender (Obs = 2, SIR = 1.9) and sander/masker or polisher (Obs = 3, SIR = 2.7). A clear association was not observed between chromate exposure and the risk of lung cancer in this population of workers.


Subject(s)
Air Pollution, Indoor/adverse effects , Aviation , Chromates/adverse effects , Lung Neoplasms/epidemiology , Occupational Exposure/adverse effects , Adult , Aerosols/adverse effects , Dust/adverse effects , Female , Follow-Up Studies , Humans , Incidence , Male , Middle Aged , Occupations , Paint/adverse effects , Retrospective Studies , Time Factors , Washington/epidemiology
18.
Biotechniques ; 11(1): 102-4, 106, 108-9, 1991 Jul.
Article in English | MEDLINE | ID: mdl-1954008

ABSTRACT

A chemiluminescent DNA detection method is described and its application shown for both single-vector and multiplex DNA sequencing using the standard dideoxy chain-termination process. This recently developed detection method, which utilizes the light emitted by an enzyme-catalyzed dioxetane reaction, is highly sensitive and affords significant advantages in safety and speed over the traditional radioactive labeling method. When adapted to a multiplex strategy, this chemiluminescent detection method constitutes a safe, simple and rapid method for increasing the throughput of DNA sequencing procedures.


Subject(s)
Base Sequence , DNA/chemistry , DNA-Directed DNA Polymerase/metabolism , Electrophoresis, Polyacrylamide Gel , Genetic Techniques , Genetic Vectors/genetics , Luminescent Measurements
20.
Appl Opt ; 29(10): 1526-9, 1990 Apr 01.
Article in English | MEDLINE | ID: mdl-20563036

ABSTRACT

The feasibility of making multilayer optical filters using polymerized solgel solutions was demonstrated. Theoretical modeling was done to determine the expected optical response of multilayer coatings with various index profiles to select a coating design which was achievable using current technology and which would demonstrate the effectiveness of the method. The selected design consisted of a multilayer film whose index profile approximated a sine function, simulating the rugate concept for maximum reflection at 1.5 microm using a silicon substrate. Samples were prepared with 21, 29, and 37 layers. Agreement between the actual and the predicted optical performance of these films was good, showing that this method can be used to produce optical coatings having complicated index profiles.

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