Polyp detection rates as quality indicator in clinical versus screening colonoscopy

Background Adenoma and Polyp Detection Rates (ADR and PDR) are advocated as general performance measures for screening and clinical colonoscopy, but their evidence is largely derived from screening data. This study compares PDRs in colonoscopy for screening versus clinical indications.

Methods Consecutive patients at two Norwegian centers were examined by eight endoscopists either for colonoscopy screening in a randomized colonoscopy screening trial (Nordic-European Initiative on Colorectal Cancer, NordICC) or for clinical indications during the same time period (January 2013 to December 2014). PDR-5 mm, defined as the proportion of colonoscopies with detection of at least one polyp with diameter ≥ 5 mm, was measured prospectively. We fitted multivariable logistic regression models and calculated the adjusted odds ratios (OR) to evaluate factors for differences in PDR-5 mm between screening and clinical colonoscopies.

Results The study included 2939 clinical and 771 screening colonoscopies. The PDR-5 mm was 26 % and 31 %, respectively (P = 0.005). Among sex, age, cecum intubation, bowel cleansing, and endoscopist, only the latter explained the higher PDR-5 mm in screening compared to routine colonoscopy. In the fully adjusted logistic regression model, the detection of polyps ≥ 5 mm was not associated with indication for colonoscopy. The OR for polyp detection in screening vs. routine colonoscopy was 1.04; 95 % confidence interval 0.85 – 1.27.

Conclusion In this study, the differences in PDR-5 mm between clinical and screening colonoscopies could be explained by the endoscopist. Accordingly, PDR-5 mm benchmarks may be similar for clinical and screening colonoscopy.

Patient-reported adverse events after colonoscopy in Norway

Background and aims Patient-reported outcome measures are increasingly important in healthcare. European guidelines have recommended inclusion of patient feedback to capture adverse events due to colonoscopy, but this is rarely implemented. Methods The Norwegian Quality Assurance network for endoscopy (Gastronet) collects patient-reported outcome for colonoscopies. Free-text comments on patient reports from January to December 2015 were characterized as positive or negative. All negative free-text comments were scrutinized for information that might suggest colonoscopy-related adverse events. We identified severe adverse events with and without admission to hospital. Results We included 16 552 outpatient colonoscopies performed at 21 hospitals. A total of 11 248 procedures (68 %) were accompanied by a patient feedback report, of which 2628 (23 %) had free-text comments (2196 [20 %] characterized as positive and 432 [3.8 %] as negative). These negative free texts on patient reports revealed 15 post-colonoscopy hospital admissions due to adverse events that had not been registered in the colonoscopy report. This increased the number of hospital admissions caused by adverse events from 3 (0.03 %) to 18 (0.16 %). In addition, there were 14 patient reports of severe events without hospital admission. Therefore, a total of 29 severe adverse events reported by patients were missed by conventional documentation in the colonoscopy form. Conclusion It is feasible to implement patient feedback as routine reporting to capture the full picture of colonoscopy-related adverse events. Some patients experience significant complications that are not recorded through any registries. Patient feedback forms should be tailored to capture adverse events after colonoscopy that are otherwise not easily disclosed.

Cecum intubation rate as quality indicator in clinical versus screening colonoscopy

BACKGROUND AND STUDY AIMS

Some guidelines recommend a minimum standard of 90 % cecal intubation rate (CIR) in routine clinics and 95 % in screening colonoscopy, while others have not made this distinction - both with limited evidence to support either view. This study questions the rationale for making such differentiation.

PATIENTS AND METHODS

 We assessed cecum intubation rates amongst colonoscopies recorded in the Norwegian national quality register Gastronet by 35 endoscopists performing both clinical and screening colonoscopies. Colonoscopies were categorized into primary screening colonoscopy, work-up colonoscopy of screen-positives and clinical colonoscopy or surveillance. Cases with insufficient bowel preparation or mechanical obstruction were excluded. Endoscopists were categorized into "junior" and "senior" endoscopists depending on training and experience. Univariable and multivariable logistic regression analyses were applied.

RESULTS

During a 2-year period, 10,267 colonoscopies were included (primary screening colonoscopy: 746; work-up colonoscopy of screen-positives: 2,604; clinical colonoscopy or surveillance: 6917). The crude CIR in clinical routine colonoscopy, primary screening colonoscopy and work-up colonoscopy was 97.1 %, 97.1 % and 98.6 %, respectively. In a multiple logistic regression analysis, there were no differences in CIR between the 3 groups. Poor bowel cleansing and female sex were independent predictors for intubation failure.

CONCLUSION

Cecal intubation rate in clinical colonoscopies and colonoscopy screening are similar. There is no reason to differentiate between screening and clinical colonoscopy with regard to CIR.

An explorative study from the Norwegian Quality Register Gastronet comparing self-estimated versus registered quality in colonoscopy performance

BACKGROUND AND STUDY AIMS

The value of a colonoscopy quality assurance (QA) register may be questioned if it brings no new information on which to act for quality improvement, e. g. if self-assessed quality of colonoscopy performance correlates perfectly with registered performance.

PATIENTS AND METHODS

In this explorative study, 39 (33 Norwegian and 6 Swedish) out of 99 new endoscopists joining the Norwegian QA register Gastronet from 2008 to 2013 responded to an invitation to fill in a questionnaire for self-assessment of cecal intubation rate, polyp detection rate for polyps ≥ 5 mm (PDR-5 mm), withdrawal time, total examination time, and rates for severely painful and pain-free colonoscopies before receiving their first-time feedback of actually registered results from Gastronet. A linear regression analysis was applied to explore the correlation between experience level and quality of estimation.

RESULTS

We included 2654 colonoscopies in our study. Endoscopists underestimated their cecal intubation rate (estimated 88.8 %, registered 93.1 %, P < 0.001), total procedure time (estimated 31.7 minutes, registered 37.2 minutes, P = 0.014), withdrawal time (estimated 9.8 minutes, registered 14.4 minutes, P = 0.006) and the rate of pain-free procedures (estimated 18.3 %, registered 24.5 %, P = 0.001). Pre-study colonoscopy experience was not correlated with estimated quality for any of the indicators.

CONCLUSIONS

Apart from overestimation of severely painful examinations, endoscopists most often underestimated their colonoscopy performance. Self-assessed quality of colonoscopy performance may not be a satisfactory substitute for systematic registration of quality and not sufficiently valid to be acted upon.

Time trends in quality indicators of colonoscopy

BACKGROUND

There is considerable variation in the quality of colonoscopy performance. The Norwegian quality assurance programme Gastronet registers outpatient colonoscopies performed in Norwegian endoscopy centres. The aim of Gastronet is long-term improvement of endoscopist and centre performance by annual feedback of performance data.

OBJECTIVE

The objective of this article is to perform an analysis of trends of quality indicators for colonoscopy in Gastronet.

METHODS

This prospective cohort study included 73,522 outpatient colonoscopies from 73 endoscopists at 25 endoscopy centres from 2003 to 2012. We used multivariate logistic regression with adjustment for relevant variables to determine annual trends of three performance indicators: caecum intubation rate, pain during the procedure, and detection rate of polyps ≥5 mm.

RESULTS

The proportion of severely painful colonoscopies decreased from 14.8% to 9.2% (relative risk reduction of 38%; OR = 0.92 per year in Gastronet; 95% CI 0.86-1.00; p = 0.045). Caecal intubation (OR = 0.99; 95% CI 0.94-1.04; p = 0.6) and polyp detection (OR = 1.03; 95% CI 0.99-1.07; p = 0.15) remained unchanged during the study period.

CONCLUSIONS

Pain at colonoscopy showed a significant decrease during years of Gastronet participation while caecal intubation and polyp detection remained unchanged - independent of the use of sedation and/or analgesics and level of endoscopist experience. This may be due to the Gastronet audit, but effects of improved endoscopy technology cannot be excluded.

[Pain in connection with colonoscopy in Norway]

BACKGROUND

Colonoscopies are common examinations at Norwegian hospitals. In contrast to many other countries, the majority of colonoscopies in Norway are conducted without routine sedation or analgesia. We wanted to investigate whether current Norwegian practice offers adequate pain relief.

MATERIAL AND METHOD

The material consists of prospectively recorded outpatient colonoscopies in the period January 2003-December 2011 performed at Norwegian hospitals in the quality assurance network for gastrointestinal endoscopy (Gastronet). We analysed demographic patient data and data from colonoscopies. Patients' experience of pain (none, slight, moderate or severe pain) in connection with the examination was established with the aid of a validated questionnaire.

RESULTS

Data from 61,749 colonoscopies (55% on women) performed at 29 different hospitals were analysed. Colonoscopies were perceived as moderately or very painful by 33% of the patients (41% of the women, 24% of the men, p < 0.001). There were substantial differences between hospitals as to the percentage of colonoscopies that were perceived as moderately or very painful (from 9% to 43%, p < 0.001) and the use of sedatives and analgesics for the colonoscopies (from 1% to 92% of the examinations, p < 0.001). Only 23% of those who found the colonoscopy painful received analgesics. Pethidine was used in 95% of the cases in which analgesics were used during the examination.

INTERPRETATION

Many patients find colonoscopies painful. Pain relief practice varies substantially between hospitals. Pethidine is an analgesic with a slow onset of action, and should perhaps be replaced with more rapidly acting opiates.

Withdrawal time as a quality indicator for colonoscopy - a nationwide analysis

BACKGROUND AND STUDY AIMS

A withdrawal time of at least 6 min has been recommended as a quality indicator for colonoscopy. One drawback of many of the studies that have investigated withdrawal time and produced conflicting results has been their single-center design involving few endoscopists. Therefore, the validity of withdrawal time as a quality measure remains unclear. This study explores the value of individual withdrawal time in a nationwide analysis.

PATIENTS AND METHODS

This prospective cohort study comprised data from outpatient colonoscopies performed at 19 Norwegian centers from January to September 2009 and registered in the Norwegian Gastronet Quality Assurance (QA) program. The participating endoscopists were characterized by their median withdrawal time for visual colonoscopies (diagnostic colonoscopies without biopsy or therapy) and categorized into two visual withdrawal time (VWT) groups (< 6 min or ≥ 6 min) to analyze the predictive value of VWT for detection of one or more polyps ≥ 5 mm in diameter using multiple logistic regression models.

RESULTS

The study included 4429 consecutive colonoscopies performed by 67 endoscopists. The adjusted odds ratio for the detection of polyps ≥ 5 mm was 1.21 (95 %CI 0.94 - 1.56, P = 0.14) for endoscopists with a median VWT ≥ 6 min compared with endoscopists with a median VWT < 6 min.

CONCLUSION

Withdrawal time using 6 min as the threshold is not a strong predictor of the likelihood of finding a polyp during colonoscopy and should not be used as a quality indicator.

Incontinence after colonoscopy--an unrecognized and preventable problem. A cross-sectional study from the Gastronet quality assurance program

BACKGROUND

Colonoscopy requires insufflation of gas for visualization of the bowel wall. Worldwide, this is usually done using air. The aim of the present study was to assess the risk of postcolonoscopy incontinence, and to investigate whether insufflation of CO₂ instead of air may reduce this risk, since it is easily absorbed through the bowel mucosa.

METHODS

This is a prospective multicenter study of colonoscopy patients undergoing bowel insufflation using air or CO₂. A successive series of colonoscopies were reported to a national quality assurance program in Norway between January and December 2009 from 21 endoscopy centers with varying insufflation practices. The study comprised 7812 patients aged 18 years or older who were referred for outpatient colonoscopy. Of these, 5015 underwent colonoscopy performed using air and 2797 colonoscopy using CO₂ insufflation.

RESULTS

Patient-reported incontinence up to 24 h after colonoscopy was compared using binary logistic regression analysis for the type of gas used for insufflation. The air and CO₂ patient groups were comparable with regard to age, sex, indication for colonoscopy, and sedation practice. Incontinence was reported by 336 out of 7812 patients (4.3%). Incontinence was significantly less frequent in the CO₂ group than in the air group [2.1% versus 5.5%; adjusted odds ratio (OR) 0.38; 95%CI 0.28-0.50; P < 0.001]. Female patients had a higher risk of incontinence than men (adjusted OR 1.77; 95% CI 1.39-2.24; P < 0.001).

CONCLUSION

About every 20th patient undergoing colonoscopy using standard air insufflation experiences postexamination incontinence. This proportion can be reduced by 60% by converting from air insufflation to insufflation with the absorbable CO₂.

"Drop in" gastroscopy outpatient clinic--experience after 9 months

BACKGROUND

Logistics handling referrals for gastroscopy may be more time consuming than the examination itself. For the patient, "drop in" gastroscopy may reduce uncertainty, inadequate therapy and time off work.

METHODS

After an 8-9 month run-in period we asked patients, hospital staff and GPs to fill in a questionnaire to evaluate their experience with "drop in" gastroscopy and gastroscopy by appointment, respectively. The diagnostic gain was evaluated.

RESULTS

112 patients had "drop in" gastroscopy and 101 gastroscopy by appointment. The number of "drop in" patients varied between 3 and 12 per day (mean 6.5). Mean time from first GP consultation to gastroscopy was 3.6 weeks in the "drop in" group and 14 weeks in the appointment group. The half-yearly number of outpatient gastroscopies increased from 696 before introducing "drop in" to 1022 after (47% increase) and the proportion of examinations with pathological findings increased from 42% to 58%. Patients and GPs expressed great satisfaction with "drop in". Hospital staff also acclaimed although it caused more unpredictable working days with no additional staff.

CONCLUSIONS

"Drop in" gastroscopy was introduced without increase in staff. The observed increase in gastroscopies was paralleled by a similar increase in pathological findings without any apparent disadvantages for other groups of patients. This should legitimise "drop in" outpatient gastroscopies, but it requires meticulous observation of possible unwanted effects when implemented.

Colonoscope with a sub-distal hyper-flaccid segment for improved insertion at colonoscopy: a randomized study

BACKGROUND

In sharp bends, particularly in the colonic flexures, the axial pushing force conveyed to the distal actively bending tip of the endoscope may cause impaction rather than progression. It is hypothesized that colonoscopes with a very flaccid segment immediately proximal to the distal bending tip might reduce this problem.

MATERIAL AND METHODS

Two prototype colonoscopes with a flaccid passively bending segment (either progressively graded or ungraded flaccidity) positioned immediately proximal to the distal actively bending tip was evaluated in a single-blinded randomized study. The primary end-point was patients' evaluation of pain.

RESULTS

Altogether, 400 patients were randomized 1:1 to examination with a prototype (60 patients to endoscope with graded flaccidity; 141 to the endoscope with ungraded flaccidity) or a standard colonoscope. The groups were similar regarding age, sex and previous abdominal surgery. Severe pain was reported by 7% of patients in the prototype and 18% in the standard group (p = 0.001). There was a trend toward shorter cecal intubation time in the prototype group (mean 14.1 min, 95% CI 12.8-15.3) compared to the standard group (mean 15.5 min, 95% CI 14.3-16.7) (p = 0.12) and similar intubation rates (89% and 85%, respectively). Results for first (ungraded flaccidity) and second (graded flaccidity) generation prototypes collectively were similar to the second generation separately.

CONCLUSIONS

The concept of an endoscope with a hyper-flaccid segment may facilitate negotiation of sharp bends and reduce pain without compromising cecal intubation rate or intubation time.

Quality assurance as an integrated part of the electronic medical record - a prototype applied for colonoscopy

OBJECTIVE

Electronic medical records (EMRs) have not developed much beyond the days of typewritten journals when it comes to facilitating extraction of data for quality assurance (QA) and improvement of health-care performance.

MATERIAL AND METHODS

Based on 5 years' experience from the Norwegian Gastronet QA programme, we have developed a highly QA-profiled EMR for colonoscopy. We used a three-tier solution (client, server and database) written in the Java programming language using a number of open-source libraries. QA principles from the Norwegian paper-based Gastronet QA programme formed the basis for development of the ColoReg software. ColoReg is developed primarily for colonoscopy reporting in a screening trial, but may be used in routine clinical work. The QA module in ColoReg is well suited for intervention towards suboptimal performance in both settings.

RESULTS

We have developed user-friendly software dominated by clickable boxes and curtain menus reducing free text to a minimum. The software gives warnings when illogical registrations are entered and reasons have to be given for divergence from software recommendations for work-up and surveillance. At any time, defined performance quality parameters are readily accessible in tabular form with the named, logged-in endoscopist being compared with all other anonymized endoscopists in the database.

CONCLUSION

The ColoReg software is developed for use in an international, multicentre trial on colonoscopy screening. It is user-friendly and secures continuous QA of the endoscopist's performance. The principles used are applicable to development of EMRs in general.

Improvement in caecal intubation rate and pain reduction by using 3-dimensional magnetic imaging for unsedated colonoscopy: a randomized trial of patients referred for colonoscopy

OBJECTIVE

Use of magnetic endoscope imaging (MEI) during colonoscopy has the potential to ease caecal intubation and patient discomfort and to reduce dependence on sedation and/or analgesics (SAs). However, pain reduction by using MEI has not been demonstrated so far, probably because of the liberal use of SAs. The aim of the present study was to evaluate the effect of MEI on caecal intubation and patient pain during unsedated colonoscopy performed by experienced and inexperienced colonoscopists.

MATERIAL AND METHODS

A consecutive series of outpatients referred for colonoscopy were randomly allocated to examination with (imager group) or without (standard group) the use of MEI. Patients agreeing to SAs being given only on demand were included in the study. End-points were caecal intubation and pain, the latter to be graded by category on a form to be completed on the day after the examination.

RESULTS

The proportion of colonoscopies performed without SAs was similar when comparing imager and standard groups and experienced with inexperienced colonoscopists; altogether 367(88%) out of 419 colonoscopies. The caecal intubation rate was higher in the imager group (190/212 (90%)) than in the standard group (153/207(74%)) (p<0.001), both collectively and separately for experienced and inexperienced colonoscopists. A pain-reducing effect of MEI was shown only when performed by experienced colonoscopists, with severe pain in 10/137 patients (7.3%) in the imager group and 21/132 patients (16%) in the standard group (p=0.03).

CONCLUSIONS

In colonoscopy without the routine use of SAs, MEI significantly improves the caecum intubation rate and reduces pain during the procedure.

Carbon dioxide insufflation reduces discomfort due to flexible sigmoidoscopy in colorectal cancer screening

BACKGROUND

Flexible sigmoidoscopy is currently recommended as a screening modality for colorectal cancer. However, a substantial number of patients experience discomfort because of the procedure. possibly limiting compliance and thus screening success. During endoscopy, air is commonly used to insufflate the bowel. Carbon dioxide rather than air insufflation has been shown to reduce procedure-related pain and discomfort in colonoscopy. The aim of the present study was to evaluate whether carbon dioxide insufflation reduces discomfort during and after flexible sigmoidoscopy for colorectal cancer screening.

METHODS

In a randomized, double-blinded design, 230 consecutive participants in a population-based flexible sigmoidoscopy colorectal cancer screening trial were assigned to have their examination performed with either carbon dioxide or air insufflation. Patients were asked to grade discomfort experienced both during and in the hours after the procedure on a visual analogue scale.

RESULTS

Carbon dioxide insufflation significantly reduced the amount of discomfort at 1, 3 and 6 h after the sigmoidoscopy. One hour after the examination. 84% of patients in the CO2 group reported no discomfort, compared to 64% in the air group (P = 0.006). No differences between the groups were observed during the examination.

CONCLUSIONS

Carbon dioxide insufflation significantly reduced post-examination discomfort. The use of carbon dioxide rather than air insufflation may contribute to better public acceptance for flexible sigmoidoscopy screening.

Influence of long-term supplementation with alpha-linolenic acid on myocardial lipid peroxidation and antioxidative capacity in spontaneously hypertensive rats

The ischaemic vulnerability of the heart of spontaneously hypertensive rats (SHR) is enhanced after feeding an alpha-linolenic acid (LNA) enriched diet. Because oxygen radical-induced reactions (e.g. lipid peroxidation) are involved in the ischaemic damage, an increased susceptibility of the SHR heart to such damaging reactions might be the reason. As a sign of the enhanced susceptibility to lipid peroxidation of LNA-fed SHR, we found (measured as TBARS) higher plasma and heart lipid peroxide levels (3.84 +/- 0.50 micromol/l vs 2.98 +/- 0.78 micromol/l and 507 +/- 127 nmol/g prot. vs 215 +/- 80 nmol/g prot., respectively) after feeding LNA. Using Fe2+/Vit. C to induce lipid peroxidation in myocardial tissue homogenates, we demonstrated the enhanced susceptibility to lipid peroxidation of the LNA-fed SHR heart (68 +/- 12 nmol/min x g prot. vs 40 +/- 8 nmol/min x g prot.) also in vitro. The myocardial enrichment of n-3 polyunsaturated fatty acids (PUFA) resulting in a higher peroxidation index (PI 227 vs. 170) and the loss in myocardial activities of the antioxidative enzymes (SOD: 76 +/- 24 U x 10(3)/g prot. vs 235 +/- 150 U x 10(3)/g prot.; GSH-Px: 32 +/- 5 U/g prot. vs 110 +/- 30 U/g prot.) by feeding LNA could be the cause of the increase in myocardial susceptibility to lipid peroxidation of PUFA supplemented SHR.

Structural wall tissue alterations of the microvasculature in the course of spontaneous hypertension of rats

The existence of structural reactions of the microvasculature of spontaneously hypertensive rats (SHR) and the underlying causal mechanisms are generally controversially discussed. Ninety-two male SHR aged 3-52 weeks and 118 normotensive age and sex matched controls were investigated. A new histomorphometric procedure was applied that ascertains structural changes in microvessels with diameters below 9 microns, between 9 microns and 19 microns and above 19 microns in anatomically defined sections of the skeletal muscle, heart and pancreas. Significant rises in the numerical and area densities of microvessel surfaces document a pathological increase in wall tissue of the microvasculature in all 3 organs and stages of spontaneous hypertension, with the exception of the coronary microvessels of 8-16 week old SHR where this progressive structural reaction was antagonized. How far the hypertrophy of the microvascular wall tissue is connected with an increase in wall thickness disproportional to the corresponding lumen wideness remained unknown. A positive correlation between the increase in blood pressure and wall tissue was only substantiated in the pancreas microvasculature. The generalized preferential occurrence of pathological reactions in vessels with diameters below 19 microns in the early established phase indicates that the microvascular control changes in this phase of spontaneous hypertension (SH).

Ischemic myocardial damage in spontaneously hypertensive rats (SHR) is enhanced after long-term feeding of an alpha-linolenic acid enriched diet

In this study the influence of long-term feeding of an alpha-linolenic acid (LNA) enriched diet on the sensitivity of SHR to catecholamine-induced myocardial injury was investigated. An enhanced ischemic vulnerability after LNA supplementation was observed as indicated both by a marked decrease of enzyme activities in the myocardium and by a pronounced elevation of plasma enzymes. Distinctly higher TBARS levels in heart tissue and plasma of LNA rich fed SHR suggest that an exaggerated lipid peroxidation might contribute to the increased ischemic vulnerability. Non-enzymatic lipid peroxidation is favoured by a feeding-provoked enrichment in highly unsaturated fatty acids in tissue phospholipids. Under such conditions of enhanced substrate availability for radical-induced lipid peroxidation an increased requirement for antioxidants can be assumed which might not sufficiently be met by tocopherol-supplementation in SHR because of their known defects in antioxidative defense mechanisms.

Blood pressure and serum lipids from SHR after diets supplemented with evening primrose, sunflowerseed or fish oil

Spontaneously hypertensive rats (SHR) at 4 weeks of age were fed a diet supplemented with sunflowerseed oil (SO), evening primrose oil (EPO), fish oil (FO) or EPO + FO for 22 weeks. A diet with commercially available pellets served as control. Systolic blood pressure was significantly lower during and after FO, EPO and EPO + FO, whereas the lower level after SO was not significant when compared with the controls. Serum triglycerides and total cholesterol were lowest after EPO followed FO. The combination of both EPO and FO resulted in unexpected high values of triglycerides and cholesterol. HDL-cholesterol was likewise highest after EPO + FO. The results indicate a quantitatively different depression of blood pressure and serum lipids from SHR by individual polyunsaturated fatty acids (PUFA).

N-6 and N-3 PUFA in liver lipids, thromboxane formation and blood pressure from SHR during diets supplemented with evening primrose, sunflowerseed or fish oil

Spontaneously hypertensive rats (SHR) after weaning (at 4 weeks of age) were fed diets supplemented with either sunflowerseed oil (SO), evening primrose oil (EPO), fish oil (FO) or EPO + FO (50%: 50%, v/v) for 22 weeks. A diet with commercially available pellets served as control. Systolic blood pressure was significantly lower in the dietary groups receiving FO, EPO and FO + EPO, the former being most effective. In liver triglycerides (TG) EPO resulted in a markedly increased percentage of linoleic acid (LA; C 18:2, n-6), alpha-linolenic acid (alpha-LNA; C 18:3, n-6) and especially of arachidonic acid (AA; C 20:4, n-6), whereas the long-chain n-3 polyunsaturated fatty acids (PUFA), eicosapentaenoic acid (EPA; C 20:5, n-3) and docosahexaenoic acid (DHA; C 22:6 n-3), were depressed to undetectable and significantly lower levels, respectively. In liver phosphatidylcholine (PC) and phosphatidylethanolamine (PE) only slight changes of LA and AA were observed. Feeding of FO led to a significant rise of EPA and DHA in liver TG, PC and PE at the expense of n-6 PUFA (except LA in PC and PE). With a combination of both EPO and FO a significant increase of EPA and DHA, but on lower levels as compared to FO alone, was associated with a significant rise of LA, but with a slight decline of AA as compared to the control animals. Nevertheless, the levels of AA in the group fed EPO + FO were still higher than in the FO-group. In the SO-group the increase of LA was even higher when compared with the EPO-group.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteria and gallstone nucleation

This preliminary study reports for the first time that there might be a possible association between bacteria and the aetiology of some cholesterol calculi. The gall-bladder biles from 225 cholecystectomy patients underwent bacteriological and microscopic study. Cholesterol calculi from 13 patients (10.2%) were observed to be associated with gall-bladder bile profusely infected with at least one bacterial species that was shown to possess beta-glucuronidase activity, an enzyme that is thought to promote calcium bilirubinate precipitation in bile. Concomitantly, the associated gall-bladder bile was 'high' in calcium bilirubinate precipitation and the precipitate was also detected in the centre of the gallstones. Moreover, in approximately half of these patients (six of 13), the cholesterol gallstones' nuclear areas also contained calcium palmitate, which is also thought to be due to bacterial activity. The results also support the hypothesis that bacteria with active beta-glucuronidase (for example, Escherichia coli) can significantly influence the aetiology of brown pigment gallstones. In contrast, bacteria were observed to have no role in black pigment gallstone formation, as their associated gall-bladder biles were always observed to be sterile.

Streptozotocin diabetes in spontaneously hypertensive rats

The aim of our experiments was to find out to what extent male spontaneously hypertensive (SH) as well as normotensive Wistar-Kyoto (WKY) and Wistar-Schönerlinde (WS) rats developed changes of the endocrine pancreas function in response to streptozotocin (SR). 4 week old WS, WKY and SH rats were given ip. injections of 70 or 100 mg SR/kg and were killed at an age of 8 weeks, after which blood glucose, and in isolated islets, insulin-leakage, insulin secretion and insulin biosynthesis were determined; histologically the relative volume density of islet tissue was estimated. The results demonstrated that the intensity of the SR-caused damage to the endocrine pancreas differs considerably in the three strains of rats. The damage increases in the order WS, WKY, SH rats. These findings are indicative of the role played by genetic predisposition and of an increase in damage to the endocrine pancreas due to hypertension.

Blood pressure and heart rate responses to intracerebroventricular infusion of sodium chloride solution in normotensive and hypertensive rats

An increased central salt sensitivity is thought to be basically involved in hypertension. Therefore, in anaesthetized normotensive (Wistar, WKY) and hypertensive (SHR) rats, small amounts (10 microliters in 20 min) of both isotonic and hypertonic NaCl solutions (0.154 M, 0.3 M, 0.6 M and 1.0 M) were i.c.v. applied and blood pressure (BP) and heart rate (HR) responses registered. Central administration of hypertonic NaCl solution caused an elevation in BP and HR in both strains. The response magnitude was positively correlated to the NaCl concentration used. This increase could be interrupted by i.v. injection of a ganglionic blocker (tetraethylammoniumbromide). Despite of differences in time course, the magnitude of the BP and HR increases were much more elevated in SHR and WKY than in Wistar rats, suggesting strain differences. Considering the results obtained with 1.0 M NaCl solution, the following values were reached: in Wistar: delta syst. BP +15.7 mm Hg, delta HR +23.3 bpm; in WKY: delta syst. BP +40.2 mm Hg, delta HR +51.6 bpm; in SHR: delta syst. BP +46.0 mm Hg, delta HR +48.0 bpm. On the contrary, isotonic NaCl solution, when centrally applied, caused an elevation in HR (+25 bpm) and BP (delta syst. BP +6.2 mm Hg) only in SHR. These results support the idea that an exaggerated central sensitivity to sodium chloride may participate in hypertension.

Changes of N-6 and N-3 fatty acids in liver from spontaneously hypertensive (SHR) and normotensive rats after diets supplemented with alpha-linolenic or eicosapentaenoic acids

In spontaneously hypertensive (SHR) and normotensive rats (WKY), diets supplemented with n-3 fatty acids of different chain length (alpha-linolenic acid, LNA-C 18:3, n-3 with linseed oil and eicosapentaenoic acid, EPA-C 20:5, n-3 with cod liver oil) were fed over a period of 22 weeks. A diet with commercially available pellets served as control. After the LNA-rich diet the augmentation of LNA was most pronounced in liver triglycerides (TG) and free fatty acids (FFA), whereas the increase of EPA was most marked in phosphatidylethanolamine (PE) and phosphatidylcholine (PC) when compared with the controls. Docosahexaenoic acid (DHA) was decreased mainly in neutral lipids. Of the n-6 fatty acids linoleic acid (LA) appeared significantly depressed in TG and FFA, but increased in phospholipids. Arachidonic acid (AA), however, was lower in all lipids. In SHR and WKY fed the EPA-rich diet EPA and DHA were significantly higher as compared to the controls on a pellet diet. On the contrary, LNA was not detectable in all lipid classes. LA and AA were markedly depressed. Docosenoic acids were significantly increased. The p/s-ratio did not reflect the changes in the 20:5/20:4- and n-3/n-6-ratios. The data indicate a differential effect of dietary n-3 fatty acids of different chain length on the supply of other n-3 fatty acids. Moreover, after an LNA-rich diet divergent alterations of LA in neutral lipids and phospholipids occurred. The results are dissimilar to those obtained in adipose tissue. Blood pressure was not influenced by the diets in either SHR or WKY.

Different changes of n-6 and n-3 fatty acids in adipose tissue from spontaneously hypertensive (SHR) and normotensive rats after diets supplemented with linolenic or eicosapentaenoic acids

In spontaneously hypertensive (SHR) and normotensive rats of the Wistar-Kyoto (WKY) and Wistar-Schönwalde (WSCHOE) strain, diets supplemented with n-3 fatty acids of different chain length (alpha-linolenic acid, LNA--C 18:3, n-3 with linseed oil and eicosapentaenoic acid, EPA--C 20:5, n-3 with cod liver oil) were fed over a period of 22 weeks. After the LNA-rich diet, among the long-chain n-3 fatty acids EPA in epididymal adipose tissue remained unchanged, whereas docosapentaenoic (DPA) and docosahexaenoic acids (DHA) fell. The n-6 fatty acids linoleic (LA) and arachidonic acid (AA) both appeared decreased. After the EPA-rich diet, all n-3 fatty acids, i.e. not only EPA, DPA and DHA, but also LNA were augmented when compared with controls fed commercially available pellets. Among the n-6 fatty acids LA was extremely depressed, whereas AA appeared increased. The p/s-ratio was elevated after the LNA-rich diet, but decreased after the EPA-rich diet. The data indicate a differential effect of dietary n-3 fatty acids of different chain length on the supply of other n-3 fatty acids, of LA and AA as well as on the p/s-ratio in adipose tissue of rats. Blood pressure was not influenced by either diet in either SHR or in both normotensive strains of rats.

Microbial contamination of domiciliary nebuliser therapy equipment

Fifty-two outpatients requiring domiciliary nebulised bronchodilator therapy were studied to determine the frequency and degree of contamination of nebuliser solutions and equipment. In 32 of the 52 patients (61%) nebuliser solutions and/or aerosols were contaminated. The degree of contamination was greater than that of ambient air in 90% of the contaminated aerosols. Diluent solutions were more frequently contaminated than salbutamol solutions (51% vs. 9%) and the organisms isolated from the solutions frequently correlated with those in aerosols. Gram-negative bacilli, particularly Pseudomonas species, were the most frequently isolated organisms.

Changes of arachidonic acid in phosphatidylcholine different from other lipids in kidneys of spontaneously hypertensive rats after feeding a linoleic acid-rich diet

In spontaneously hypertensive rats (SHR) fed a linoleic acid-rich (LAR) diet over 22 weeks blood pressure could not be influenced when compared with SHR on linoleic acid-deficient (LAD) food. On the other hand, normotensive Wistar rats (WR) revealed a significantly lower blood pressure after feeding a LAR diet. The percentages of LA and AA were markedly increased in triglycerides and free fatty acids (FFA) in renal cortex and medulla of LAR-fed SHR and WR in comparison to LAD-fed animals. In renal phosphatidylethanolamine (PE) LA was also increased whereas AA remained unchanged. On the contrary, in phosphatidylcholine (PC) LA was only slightly augmented (in SHR) or even lowered (in WR), AA appearing decreased in SHR but increased in WR. These different changes in PE and PC indicate that individual phospholipids show a dissimilar behavior after dietary interventions, which can be masked by the evaluation of total phospholipids and might be of pathophysiological relevance.

Age-dependent alterations of linoleic, arachidonic and eicosapentaenoic acids in renal cortex and medulla of spontaneously hypertensive rats

The lipid content as well as the fatty acid pattern of triglycerides, free fatty acids (FFA), phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were estimated in renal cortex and medulla of spontaneously hypertensive rats (SHR) and normotensive Wistar rats (WR) at 4, 8, 26 and 52 weeks of age. In general, the level of triglycerides in renal medulla appeared higher when compared with the cortex. On the other hand, PC and PE, increasing with age, were usually higher in the cortex. A decreased percentage of linoleic acid (LA) in triglycerides, of arachidonic acid (AA) in PC and of eicosapentaenoic acid (EPA) in triglycerides, FFA, PC and PE could be found in the kidneys of SHR at 8 weeks of age, i.e. during the development of hypertension. This was accompanied with a rise of AA in FFA of SHR at 8 weeks of age, which occurred with delay in WR (at 26 weeks of age). From the data presented it can be concluded that systematic alterations in the availability of individual polyunsaturated fatty acids (PUFA) in various renal lipids might be related to the onset of hypertension in SHR which should be elucidated in more detail.

Changes of polyunsaturated fatty acids in serum lipids of spontaneously hypertensive rats during the onset of high blood pressure

The fatty acid pattern of serum triglycerides and cholesterol esters has been estimated in spontaneously hypertensive rats (SHR) and normotensive Wistar rats (WR) at 4, 5, 6, 7, and 8 weeks of age. The percentage of linoleic acid (LA) was lower in SHR when compared with WR, but increased with age in both strains. Arachidonic acid (AA) showed an abrupt fall in SHR and WR at 5 weeks of age in comparison to 4 week old rats. The fall was more pronounced in serum triglycerides of the former and in cholesterol esters of the latter. The changes in AA occurred prior to the onset of hypertension in SHR. From the data it can be concluded that the formation of AA from LA might be dependent on age being quantitatively different in SHR and WR. Furthermore, eicosapentaenoic acid (EPA) appeared lower in SHR than in age-related WR. Docosapentaenoic and docosahexaenoic acids also revealed a marked decrease in rats between 4 and 5 weeks of age indicating that individual polyunsaturated fatty acids (PUFA) change in a different manner which might be relevant to the development of high blood pressure in SHR.

Postoperative wound infections: a study of bacteriology and pathogenesis

Of 200 patients, 6.5% were skin carriers of Staphylococcus aureus and 3.5% became skin carriers after admission. Development of skin carrier state was associated with a long preoperative hospital stay. A second study of 275 cases showed that skin carriers of S. aureus had a significantly higher subsequent staph wound infection rate than non-carriers, but nose and/or throat carriers of S. aureus did not. Peroperative wound contamination was a significant factor in the subsequent development of wound infection. In clean surgery the infection rate was 5.9%. Both wound contamination and infection was due to gram positive organisms, usually S. aureus. When the gastrointestinal or biliary tract had been opened, the infection rate was 28%, the usual contaminating and infecting organisms were enteric and only occasionally S. aureus. There is a need for improved methods of minimizing peroperative wound contamination.

[Morphologic reactions and long-term vasal tonus behavior of the coronary microvascular system in different states of spontaneous hypertension in the rat]

The morphological reactions and the long-term vasotonus behaviour of the coronary microvasculature including its smallest ramifications as well as the relationships existing between these reactions and the myocardial activity in the different stages of spontaneous hypertension of rats (SHR) are unknown. Therefore 80 1-12 month-old male SH- and 60 normotensive Wistar control rats were histomorphometrically investigated. Already in the prestage of hypertension (1 month) an increase of wall thickness and phosphatase activity in blood vessels alpha less than 10,5 microns occurred. These appearances of vasotonus increase were regressed in the acute phase (2nd-4th month). When the rise of myocardial activity is lowered in the stabile stage the mentioned signs of vasotonus increase returned (6th month) and showed a strong spreading in the late stage (12th month), which is characterized by enzyme histochemically detected disturbances of heart muscle metabolism. The behaviour of long-term vasotonus of the microvasculature and myocardial metabolism in 6 month-old and older rats provides a hypothesis concerning the cause of the unknown increase of coronary contraction in the stabile phase. It points to the existence of a vicious circle which perhaps plays a role in the genesis of heart insufficiency in hypertension.

Polyphosphoinositide metabolism in erythrocytes from spontaneously hypertensive rats

Incorporation of 32P into di- and triphosphoinositides of erythrocytes from 1-month-old spontaneously hypertensive rats was lower, and diphosphoinositide content higher, than in controls. During development of hypertension these initial differences decreased and were even reversed.

The fatty acid pattern of triglycerides and FFA in serum of spontaneously hypertensive rats (SHR)

The fatty acid patterns of serum triglycerides and FFA in SHR and in normotensive controls aged 4, 8 and 26 weeks were estimated by gas-liquid chromatography. In serum triglycerides of SHR, the percentage of linoleic acid (C18:2) was lower and the content of arachidonic acid (C20:4) higher than in age-matched control animals. A continuous increase in palmitic (C16) and linoleic acids as well as a decrease in arachidonic acid has been found with advancing age, the most striking differences existing between 4- and 8-week-old animals, i.e. before onset of arterial hypertension in SHR. In the pre-hypertensive stage, the percentage of arachidonic acid was about 3 times as high as in later stages in SHR. This gradation was, however, even more pronounced in normotensive control rats. The C18:2/C20:4-ratio of triglycerides was lower in SHR but increased with age in both groups reaching a 5--8-fold level. Similar behavior of the FFA fatty acid pattern was less marked. Alterations in levels of linoleic and arachidonic acids are of interest because of their pathogenic role as precursors of prostaglandins in the development of genetically spontaneous hypertension in rats. The results are discussed in connection with the hypotensive effect of a linoleic acid-rich diet recently reported in hypertensive rats.

Adipose cell size in spontaneously hypertensive rats (SHR)

The size of adipose cells in spontaneously hypertensive rats (SHR) and normotensive controls has been evaluated at 4, 8 and 26 weeks of age. Age-matched groups showed significant differences only in 8-week-old rats, but this can be explained by the lower body weight of SHR. In both groups of animals fat cell size varies with body weight (r = 0.965 in SHR and r = 0.863 in normotensive rats) independent of the stage of hypertension. The regression lines are not significantly different. Thus, no evidence of enlarged adipocytes in SHR has been obtained.