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1.
Res Social Adm Pharm ; 17(11): 2006-2014, 2021 11.
Article in English | MEDLINE | ID: mdl-33775557

ABSTRACT

AIMS: To explore the impact of a prescribing feedback intervention on insulin prescribing. METHODS: This was a mixed-methods study in a hospital setting. An insulin prescribing feedback intervention was delivered verbally and in writing to twelve doctors. Insulin prescribing error frequency was compared to ten doctors who had not received the feedback intervention. Insulin prescribing was audited over four weeks at the start and end of the intervention period. Semi-structured interviews were conducted with participating doctors who had received feedback, and qualitative data analysed thematically to explore the impact of the intervention on their prescribing practice. RESULTS: Prescribing data were collected on 370 insulin prescriptions with 241 errors identified. A significant reduction (χ2 = 22.6, p=<0.05) in insulin prescribing error frequency was observed in the intervention group, with a non-significant increase reported in the control group. Feedback was received positively and considered valuable by doctors, supporting development of their knowledge and skills and encouraging reflection on their prescribing performance. Doctors described enhanced confidence in insulin prescribing and a desire to improve as a prescriber and avoid harm, with feedback raising awareness of their development needs. Prescribers also described enhanced team work, with greater information and feedback seeking behavior to inform future prescribing decisions. CONCLUSIONS: Feedback has potential to improve insulin prescribing and is a valued and acceptable process intervention for doctors. The impact on insulin prescribing practice is varied and complex influencing the capability, opportunity and motivation of prescribers to adapt and evolve their behavior in response to ongoing feedback.


Subject(s)
Insulin , Pharmacists , Drug Prescriptions , Feedback , Hospitals , Humans , Medication Errors/prevention & control , Pilot Projects
2.
Res Social Adm Pharm ; 17(9): 1579-1587, 2021 09.
Article in English | MEDLINE | ID: mdl-33341404

ABSTRACT

BACKGROUND: Prescribing errors are prevalent in hospital settings with provision of feedback recommended to support prescribing of doctors. Feedback on prescribing has been described as feasible and valued but limited by doctors, with pharmacists described as credible facilitators of prescribing feedback. Evidence supporting prescribing feedback has been limited to date. A formalised programme of pharmacist-led prescribing error feedback was designed and implemented to support prescribers. OBJECTIVE: To evaluate the impact of a prescribing feedback intervention on prescribing error rates and frequency of prescribing error severity and type. METHOD: Prospective prescribing audits were undertaken across sixteen hospital wards in a UK teaching hospital over a five day period with 36 prescribers in the intervention group and 41 in the control group. The intervention group received pharmacist-led, individualised constructive feedback on their prescribing, whilst the control group continued with existing practice. Prescribing was re-audited after three months. Prescribing errors were classified by type and severity and data were analysed using relevant statistical tests. RESULTS: A total of 5191 prescribed medications were audited at baseline and 5122 post-intervention. There was a mean prescribing error rate of 25.0% (SD 16.8, 95% CI 19.3 to 30.7) at baseline and 6.7% (SD 9.0, 95% CI 3.7 to 9.8) post-intervention for the intervention group, and 19.7% (SD 14.5, 95% CI 15.2 to 24.3) at baseline and 25.1% (SD 17.0, 95% CI 19.8 to 30.6) post-intervention for the control group with a significant overall change in prescribing error rates between groups of 23.7% (SD 3.5, 95% CI, -30.6 to -16.8), t(75) = -6.9, p < 0.05. The frequency of each error type and severity rating was reduced in the intervention group, whilst the error frequency of some error types and severity increased in the control group. CONCLUSION: Pharmacist-led prescribing feedback has the potential to reduce prescribing errors and improve prescribing outcomes and patient safety.


Subject(s)
Medication Errors , Pharmacists , Feedback , Hospitals, Teaching , Humans , Medication Errors/prevention & control , Prospective Studies
4.
Res Social Adm Pharm ; 14(6): 545-554, 2018 Jun.
Article in English | MEDLINE | ID: mdl-28684117

ABSTRACT

BACKGROUND: Prescribing errors occur frequently in hospital settings. Interventions to influence prescribing behaviour are needed with feedback one potential intervention to improve prescribing practice. Doctors have reported a lack of feedback on their prescribing previously whilst the literature exploring the impact of feedback on prescribing behaviour is limited. OBJECTIVES: To explore the impact of pharmacist-led feedback on prescribing behaviour. METHODS: Semi-structured interviews were conducted with doctors who had received prescribing error feedback. A topic guide was used to explore the type of error and what impact feedback was having on prescribing behaviour. All interviews were transcribed verbatim and analysed thematically using a framework approach. RESULTS: Twenty-three prescribers were interviewed and 65 errors discussed over 38 interviews. Key themes included; affective behaviour, learning outcome, prescribing behaviour and likelihood of error recurrence. Feedback was educational whilst a range of adaptive prescribing behaviours were also reported. Prescribers were more mindful and engaged with the prescribing process whilst feedback facilitated reflection, increased self-awareness and informed self-regulation. Greater information and feedback-seeking behaviours were reported whilst prescribers also reported greater situational awareness, and that they were making fewer prescribing errors following feedback. CONCLUSIONS: Pharmacist-led feedback was perceived to positively influence prescribing behaviour. Reported changes in prescriber behaviour resonate with the non-technical skills (NTS) of prescribing with prescribers adapting their prescribing behaviour depending on the environment and prescribing conditions. A model of prescribing is proposed with NTS activated in response to error provoking conditions. These findings have implications for prescribing education to make it a more contextualised educational process.


Subject(s)
Interprofessional Relations , Medication Errors/psychology , Pharmacists , Physicians , Attitude of Health Personnel , Behavior , Female , Humans , Male , Practice Patterns, Physicians' , Qualitative Research
5.
Res Social Adm Pharm ; 12(3): 461-74, 2016.
Article in English | MEDLINE | ID: mdl-26482469

ABSTRACT

BACKGROUND: Prescribing error (PE) rates have been extensively reported in the literature. Various interventions at reducing PEs have been studied with some success, yet PEs continue to be a challenge for the health care system. Prescriber feedback has been proposed as one mechanism to reduce PEs in seminal studies. Pharmacists are viewed as an integral safety net in intercepting PEs and have been suggested as best placed to deliver feedback. However, there is very limited literature considering pharmacists; attitudes, views and opinions on facilitating PE feedback. OBJECTIVES: To explore the attitudes and views of hospital pharmacists in delivering feedback on PEs to prescribers. METHODS: Twenty-four pharmacists were recruited for one of four focus groups in a large district general hospital in the Northwest of England to explore the views of pharmacists to delivering feedback on PEs. Focus groups were transcribed verbatim and analyzed using a thematic framework approach to identify current practices, beliefs and attitudes of pharmacists toward delivering PE feedback. Transcripts were independently analyzed by the research team. RESULTS: Pharmacists' views on providing feedback on PEs were organized into eight major themes; Delivery of feedback, impact of feedback, prescription error, work environment, feedback facilitator, working relationships, education and training, and system improvements. Pharmacists recognized that timely feedback on PEs was essential for prescribers to learn from their mistakes and to reduce PEs. However, delivery of feedback appeared to be inconsistent, influenced by time pressures, workload, rapport and PE severity and prescriber availability. Pharmacists reported that ward-based pharmacists in particular, were suitable to facilitate PE feedback, but expressed concern that the process may adversely affect prescriber-pharmacist rapport. Pharmacists reported limited training on delivery of feedback with formalized training required for improved consistency, and quality, of constructive feedback. CONCLUSIONS: PE feedback should be delivered to prescribers with ward-based pharmacists best suited to the role. Both direct and indirect benefits of PE feedback were reported, although potential barriers to delivering PE feedback were also identified. Pharmacists reported additional anxieties that feedback could create tensions and compromise working relationships with prescribers. PE feedback could be considered an extension of a pharmacist's role and pharmacists welcomed formalization of feedback, but were cognizant of the potential impact on their workload and expressed the need for training in the delivery of feedback.


Subject(s)
Attitude of Health Personnel , Formative Feedback , Medication Errors , Pharmacists , England , Female , Focus Groups , Humans , Interprofessional Relations , Male , Pharmacy Service, Hospital
6.
Br J Hosp Med (Lond) ; 76(12): 713-8, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26646334

ABSTRACT

Doctors have reported a lack of awareness of their prescribing errors with lack of feedback considered a system failure. This article summarizes the views of hospital doctors about receiving formal prescribing error feedback from ward-based pharmacists.


Subject(s)
Drug Prescriptions , Medication Errors/prevention & control , Pharmacists/organization & administration , Pharmacy Service, Hospital/organization & administration , Practice Patterns, Physicians'/standards , Professional Role , Surveys and Questionnaires , Cross-Sectional Studies , Feedback , Female , Humans , Male
7.
Diabet Med ; 32(12): 1652-7, 2015 Dec.
Article in English | MEDLINE | ID: mdl-25884635

ABSTRACT

AIM: To conduct an audit of insulin pump therapy in the UK after the issue of guidelines for the use of continuous subcutaneous insulin infusion by NICE in 2008 (Technology Appraisal 151). METHODS: All centres in the UK, providing pump services to children and young people were invited to participate in an online audit. Audit metrics were aligned to NICE Technology Appraisal 151 and an electronic data collection tool was used. RESULTS: Of the 176 UK centres identified as providing pump services, 166 (94.3%) participated in the study. A total of 5094 children and young people were identified as using continuous subcutaneous insulin infusion (19% of all paediatric patients with Type 1 diabetes), with a median (range) of 16.9 (0.67-69.4)% per centre. Units had a median of 0.58 consultant sessions, 0.43 full-time equivalent diabetic specialist nurses, and 0.1 full-time equivalent dieticians delivering the pump service. The majority of this time was not formally funded. Families could access 24-h clinical and technical support (83% units), although the delivery varied between consultant, diabetic specialist nurse and company representatives. Only 53% of units ran, or accessed, structured education programmes for continuous subcutaneous insulin infusion use. Most units (86%) allowed continuous subcutaneous insulin infusion use for paediatric inpatients, but only 56% had written guidelines for this scenario. Nine percent of units had encountered funding refusal for a patient fulfilling NICE (Technology Appraisal 151) criteria. CONCLUSION: The number of children and young people on continuous subcutaneous insulin infusion therapy is consistent with numbers estimated by NICE. There is a worrying lack of funded healthcare professional time. The audit also identified gaps in the provision of structured education and absence of written inpatient guidelines.


Subject(s)
Adolescent Medicine/methods , Diabetes Mellitus, Type 1/drug therapy , Guideline Adherence , Insulin Infusion Systems , Needs Assessment , Practice Guidelines as Topic , Adolescent , Adolescent Medicine/standards , Child , Clinical Protocols/standards , Combined Modality Therapy/adverse effects , Diabetes Mellitus, Type 1/diet therapy , Diabetes Mellitus, Type 1/nursing , Diabetes Mellitus, Type 1/therapy , Diet, Diabetic , Health Care Surveys , Humans , Insulin Infusion Systems/adverse effects , Internet , Life Style , Medical Audit , Motor Activity , Patient Care Team/standards , Patient Education as Topic , United Kingdom , Workforce
8.
Diabet Med ; 31(4): 412-8, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24117515

ABSTRACT

AIMS: The National Institute for Health and Clinical Excellence (NICE) published guidelines for the use of continuous subcutaneous insulin infusion in 2008 (technology appraisal 151). The first U.K.-wide insulin pump audit took place in 2012 with the aim of determining adherence to the guidance issued in NICE technology appraisal 151. The results of the adult service level audit are reported here. METHODS: All centres providing continuous subcutaneous insulin infusion services to adults with diabetes in the U.K. were invited to participate. Audit metrics were aligned to technology appraisal 151. Data entry took place online using a DiabetesE formatted data collection tool. RESULTS: One hundred and eighty-three centres were identified as delivering adult continuous subcutaneous insulin infusion services in the U.K., of which 178 (97.3%) participated in the audit. At the time of the audit, 13 428 adults were using insulin pump therapy, giving an estimated prevalence of use of 6%. Ninety-three per cent of centres did not report any barriers in obtaining funding for patients who fulfilled NICE criteria. The mean number of consultant programmed activities dedicated to continuous subcutaneous insulin infusion services was 0.96 (range 0-8), mean whole-time equivalent diabetes specialist nurses was 0.62 (range 0-3) and mean whole-time equivalent dietitian services was 0.3 (range 0-2), of which 39, 61 and 60%, respectively, were not formally funded. CONCLUSIONS: The prevalence of continuous subcutaneous insulin infusion use in the U.K. falls well below the expectation of NICE (15-20%) and that of other European countries (> 15%) and the U.S.A. (40%). This may be attributable, in part, to lack of healthcare professional time needed for identification and training of new pump therapy users.


Subject(s)
Diabetes Mellitus, Type 1/drug therapy , Guideline Adherence/statistics & numerical data , Hypoglycemic Agents/administration & dosage , Insulin Infusion Systems/statistics & numerical data , Insulin/administration & dosage , Practice Guidelines as Topic , Adult , Humans , Infusion Pumps, Implantable/statistics & numerical data , Infusions, Subcutaneous , Medical Audit , United Kingdom
9.
Postgrad Med J ; 83(978): 277-80, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17403957

ABSTRACT

OBJECTIVE: Adults with hypothalamic-pituitary disease have increased morbidity and mortality from cardiovascular disease (CVD). Therefore, the prevalence of CVD and adequacy of treatment of cardiovascular risk factors (according to current treatment guidelines) was studied in a large group of patients with hypothalamic-pituitary disease. STUDY DESIGN: In 2005, 152 consecutive adult patients with hypothalamic-pituitary disease attending our neuro-endocrine centre were clinically examined and blood pressure (BP), lipid profile, type 2 diabetes mellitus, body composition and smoking status were assessed. RESULTS: Of the 152 patients, 36.8% had treated hypertension and 28.2% had treated dyslipidaemia. Many of these patients had inadequate BP control (BP >140/85 mm Hg, 44.6%) and undesirable lipid levels (total cholesterol >4.0 mmol/l, 69%). Also, many of the untreated patients had BP and lipid levels which should have been considered for treatment (26 patients (27%) and 83 patients (76%), respectively). Smoking was admitted in 18% of patients. Central adiposity was present in 86% and obesity (body mass index > or =30) was present in 50%. CONCLUSIONS: Cardiovascular risk factors are highly prevalent and often inadequately treated in adult patients with hypothalamic-pituitary disease. Aggressive treatment of these factors is essential to reduce mortality and morbidity from CVD in these patients.


Subject(s)
Cardiovascular Diseases/etiology , Hypothalamic Diseases/complications , Obesity/etiology , Pituitary Diseases/complications , Adult , Aged , Blood Pressure/physiology , Body Composition , Diabetes Mellitus, Type 2/complications , Dyslipidemias/etiology , Female , Humans , Hypertension/etiology , Lipids/blood , Male , Middle Aged
10.
Cochrane Database Syst Rev ; (4): CD003418, 2004 Oct 18.
Article in English | MEDLINE | ID: mdl-15495054

ABSTRACT

BACKGROUND: It is unclear whether patients with type 2 diabetes who have poor glycaemic control despite maximal oral hypoglycaemic agents (OHAs) should be commenced on insulin as monotherapy, or insulin combined with oral hypoglycaemic agents (insulin-OHA combination therapy). OBJECTIVES: To assess the effects of insulin monotherapy versus insulin-OHA combinations therapy. SEARCH STRATEGY: Eligible studies were identified by searching MEDLINE, EMBASE, and The Cochrane Library. Date of last search: May 2004. SELECTION CRITERIA: Randomised controlled trials (RCTs) with 2 months minimum follow-up duration comparing insulin monotherapy (all schemes) with insulin-OHA combination therapy. DATA COLLECTION AND ANALYSIS: Data extraction and assessment of study quality were undertaken by three reviewers in pairs. MAIN RESULTS: Twenty RCTs (mean trial duration 10 months) including 1,811 participants, with mean age 59.8 years and mean known duration of diabetes 9.6 years. Overall, study methodological quality was low. Twenty-eight comparisons in 20 RCTs were ordered according to clinical considerations. No studies assessed diabetes-related morbidity, mortality or total mortality. From 13 studies (21 comparisons), sufficient data were extracted to calculate pooled effects on glycaemic control. Insulin-OHA combination therapy had statistically significant benefits on glycaemic control over insulin monotherapy only when the latter was applied as a once-daily injection of NPH insulin. Conversely, twice-daily insulin monotherapy (NPH or mixed insulin) provided superior glycaemic control to insulin-OHA combination therapy regimens where insulin was administered as a single morning injection. In more conventional comparisons, regimens utilising OHAs with bedtime NPH insulin provided comparable glycaemic control to insulin monotherapy (administered as twice daily, or multiple daily injections). Overall, insulin-OHA combination therapy was associated with a 43% relative reduction in total daily insulin requirement compared to insulin monotherapy. Of the 14 studies (22 comparisons) reporting hypoglycaemia, 13 demonstrated no significant difference in the frequency of symptomatic or biochemical hypoglycaemia between insulin and combination therapy regimens. No significant differences in quality of life related issues were detected. Combination therapy with bedtime NPH insulin resulted in statistically significantly less weight gain compared to insulin monotherapy, provided metformin was used +/-sulphonylurea. In all other comparisons no significant differences with respect to weight gain were detected. REVIEWERS' CONCLUSIONS: Bedtime NPH insulin combined with oral hypoglycaemic agents provides comparable glycaemic control to insulin monotherapy and is associated with less weight gain if metformin is used.


Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/therapeutic use , Insulin/therapeutic use , Drug Therapy, Combination , Humans , Randomized Controlled Trials as Topic
11.
Diabet Med ; 20(11): 935-41, 2003 Nov.
Article in English | MEDLINE | ID: mdl-14632720

ABSTRACT

AIMS: This open-label randomized controlled clinical trial compared the effect on glycaemic control and weight gain of repaglinide vs. gliclazide combined with bedtime NPH insulin in patients with Type 2 diabetes inadequately controlled with oral hypoglycaemic therapy [HbA1c>7.0% (DCCT aligned assay, normal range 4.6-6.2%)]. METHODS: Eighty subjects with Type 2 diabetes were randomized to 13 weeks' open-label treatment with repaglinide 4 mg t.i.d. or gliclazide 160 mg b.i.d. in combination with bedtime NPH insulin (initial dose 0.5 units/kg). The fasting blood glucose (FBG) target was < or =6.0 mmol/l. RESULTS: Baseline characteristics were similar for age, sex, weight, BMI, FBG and HbA1c. Glycaemic control improved similarly in both groups-insulin/gliclazide by (mean) 1.0%, from 9.2 to 8.2% (P=0.001) and by 0.9%, from 9.4 to 8.5% in the insulin/repaglinide group (P=0.005) (P=0.83 between groups). Weight gain averaged (mean +/- sem) 4.1 +/- 0.5 and 3.4 +/- 0.4 kg in the insulin/gliclazide and insulin/repaglinide groups, respectively (P<0.0001 for both groups from baseline) (P=0.29 between groups). The mean number of hypoglycaemic episodes experienced per patient was 2.95 +/- 0.82 (insulin/gliclazide) and 2.3 +/- 0.52 (insulin/repaglinide) (P=0.81 between groups). Both treatments were associated with significant improvements in Diabetes Treatment Satisfaction [Diabetes Treatment Satisfaction Questionnaire-potential range 0 (min) to 36 (max)]; in the insulin/gliclazide group, by 4.9 +/- 1.1 points to 33.3 +/- 0.6 (P<0.0001) and by 3.0 +/- 0.9 points to 34.6 +/- 0.4 (P=0.0006) in the insulin/repaglinide group (P=0.29 between groups). CONCLUSIONS: Over 13 weeks, both repaglinide and gliclazide, when combined with bedtime NPH insulin produce similar significant improvements in glycaemic control (-1%) and similar weight gain.


Subject(s)
Carbamates/therapeutic use , Diabetes Mellitus, Type 2/drug therapy , Gliclazide/therapeutic use , Hypoglycemic Agents/administration & dosage , Insulin, Isophane/therapeutic use , Piperidines/therapeutic use , Administration, Oral , Blood Glucose/analysis , Carbamates/adverse effects , Drug Therapy, Combination , Female , Gliclazide/adverse effects , Hemoglobin A/analysis , Humans , Hypoglycemic Agents/adverse effects , Insulin, Isophane/adverse effects , Male , Metformin/administration & dosage , Middle Aged , Patient Satisfaction , Piperidines/adverse effects , Surveys and Questionnaires , Weight Gain/physiology
12.
BMJ ; 323(7324): 1298-300, 2001 Dec 01.
Article in English | MEDLINE | ID: mdl-11731398

ABSTRACT

PROBLEM: Wasted outpatient appointments as a result of clinic non-attendance, exacerbating outpatient waiting times. DESIGN: Single centre, prospective, non-randomised, controlled study. BACKGROUND AND SETTING: Diabetes clinic in a district general hospital run by a consultant, one or two diabetes nurse specialists, a dietitian, and a podiatrist. Clinic receives 10-15 new referrals a week in a health district with a population of 340 000. KEY MEASURE FOR IMPROVEMENT: Non-attendance rate in 325 new patients who attended after the intervention compared with 1336 historical controls from the same clinic in the three years before the scheme. STRATEGY FOR CHANGE: Two weeks before their outpatient appointment new patients were sent an information pack telling them when and where to come, where to park, what to bring, who they will see, and what to expect. One week before the appointment they received a supplementary phone call. EFFECTS OF CHANGE: Telling patients what to expect reduced non-attendance rate overall from 15% (201/1336) to 4.6% (15/325), P<0.0001. Non-attendance rate was 7.3% (13/178) in those sent a pack but not phoned and 1.4% (2/147) in those sent a pack and phoned, P=0.01. LESSON LEARNT: Giving new patients detailed information reduces non-attendance to almost 1%.


Subject(s)
Appointments and Schedules , Communication , Hospital-Patient Relations , Outpatient Clinics, Hospital/organization & administration , Patient Dropouts/statistics & numerical data , Diabetes Mellitus/therapy , England , Hospitals, District , Hospitals, General , Humans , Outpatient Clinics, Hospital/statistics & numerical data , Prospective Studies , Telephone
14.
Cancer Lett ; 38(1-2): 1-7, 1987 Dec.
Article in English | MEDLINE | ID: mdl-3690500

ABSTRACT

The effects of vitamin E, vitamin B2 and selenite on DNA single strand breaks induced by Na2CrO4 were examined by alkaline elution. Incubation of Chinese hamster V-79 cells with alpha-tocopherol succinate (vitamin E) for 24 h prior to exposure to Na2CrO4 resulted in a decrease of DNA breaks produced by this compound. However, similar pretreatment with riboflavin (vitamin B2) or Na2SeO3 resulted in an enhanced formation of breaks induced by Na2CrO4. Pretreatment with Na2SeO3 resulted in increased levels of glutathione in these cells while levels of glutathione remained the same with vitamin E or vitamin B2. These results suggest that Na2CrO4 induced DNA breaks appear to be mediated by the formation of free radicals and/or cellular reductive metabolism.


Subject(s)
Chromates/toxicity , DNA Damage , Riboflavin/pharmacology , Selenium/pharmacology , Sodium Compounds , Vitamin E/pharmacology , Animals , Cells, Cultured , Cricetinae , Free Radicals , Glutathione/analysis , Selenious Acid
15.
Biochem Genet ; 24(1-2): 71-8, 1986 Feb.
Article in English | MEDLINE | ID: mdl-3008707

ABSTRACT

Twenty-four clones of EcoR1-restricted, 340-base pair (bp) DNA derived from human DNA have been sequenced and compared to a published consensus sequence for this family. No two clones were found to have identical sequences; the clones studied differed from the consensus sequence in as few as 1 or as many as 41 sites. On the average in these clones, a 5.2% divergence from exact homology was found, with 1 of 10 of the site variations being "nonrandom," i.e., cases in which five or more clones had the same nucleotide substitution at that site (viz., 53, 124, 126, 138, 152, and 157). At site 157, for example, 16 of the 24 clones differed from the reference sequence. Positions and their respective changes, as compared to the consensus sequence, are summarized. Variations are discussed with relation to possible functions for these sequences.


Subject(s)
DNA/genetics , Repetitive Sequences, Nucleic Acid , Base Sequence , DNA Restriction Enzymes/metabolism , Deoxyribonuclease EcoRI , Humans
16.
Z Naturforsch C Biosci ; 40(11-12): 854-7, 1985.
Article in English | MEDLINE | ID: mdl-2938352

ABSTRACT

There are non-random features in the occurrences of nucleotides in the DNA's of certain organisms which are detectable by statistical analyses of the entire sequence. Earlier, using the bacteriophage Phi-X 174 DNA sequence, we had reported that the self-information values for one type of dinucleotide association showed a marked periodicity when their autocorrelation coefficients were graphed. A similar, but computationally simpler, analysis has been developed which gives a comparable indication of periodicity. The difference, in average autocorrelation coefficients obtained with this analysis, between the peak values and all others has been used as an index to compare the extent of periodic non-randomness for a series of natural DNA sequences and for various artificial sequences. Calculations show that triplet periodicity, the relationship between dinucleotides separated by a single nucleotide, is characteristic only of the natural sequences of certain filamentous phages and is not found prominently in any other DNA analyzed (including sequences of similar length from plasmids, yeast, bacteria and higher animals). By shuffling nucleotides in a given sequence or by substituting selected nucleotides to alter various positions in both periodic and aperiodic sequences, we have found that an excess or deficiency of a given nucleotide at one of the three positions in a triplet reading frame can simulate the periodic characteristic. Thus, it appears that this global statistical analysis detects the tendency for single-strand phages to utilize a specific nucleotide, rather than one randomly selected, to constitute codons.


Subject(s)
Bacteriophage phi X 174/analysis , DNA, Viral/analysis , Nucleotides/analysis , Base Sequence , Periodicity
18.
Mich Nurse ; 57(4): 1-2, 1984.
Article in English | MEDLINE | ID: mdl-6565956
20.
Mich Nurse ; 57(2): 5-6, 1984.
Article in English | MEDLINE | ID: mdl-6562358
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