Long Term Results of Prostate Cancer Patients Treated with Cs131 LDR Brachytherapy Compared with Recently Published SBRT Data

PURPOSE/OBJECTIVE(S)

The use of LDR prostate brachytherapy (PB) as monotherapy has been established as a definitive treatment for prostate cancer patients with low and favorable intermediate risk. Patients choose PB in part due to it being minimally invasive with a quick return to full activity. Recently, there has been more interest in using shorter courses of radiotherapy, citing the same rationale. We present patient-reported outcomes from a cohort of patients treated at our institution treated with PB using Cs131to compare our outcomes with the 5-year data from the published RTOG 0938 MATERIALS/METHODS: We analyzed data from patients treated at our institution with Cs131 PB monotherapy who completed the EPIC questionnaire at baseline and at 1, 2, and 5 years after treatment. Urinary and bowel functions were evaluated based on the EPIC questionnaire the same way they were evaluated in the recently published RTOG 0938, assessing the proportion of patients with deterioration from baseline of >5 for urinary function and >2 for bowel function. We also report the 5- and 10-year bDFS calculated using the Kaplan Meier method RESULTS: A total of 138 patients were included in this analysis with a median age of 66 and median follow-up of 121.5 months. Change in urinary score of >2 at 1, 2, and 5 years was 62%, 53%, and 43% respectively (compared with 44.3, 51.7, and 41.3 respectively for RTOG 0938). Change in bowel score of >5 at 1, 2, and 5 years was 27%, 23%, and 25% (compared with 29.3, 28.7, and 30.6 respectively for RTOG 0938). Interestingly, there were a number of patients who reported improvement in their urinary score at 1, 2, and 5 years (26%, 36%, and 46%, respectively), The same held for patients who reported improvement in their bowel score at 1, 2 and 5 years (37%, 38% and 41%, respectively). Hence, the median urinary score was 6.25 lower at year 1, but only 2.08 lower at year 2 with no difference by year 5. The median bowel score showed zero difference at every time point. The 5-year bDFS in our cohort was 97.8% (compared to 91.3% in RTOG 0938). Our 10-year bDFS was 96%.

CONCLUSION

Single modality PB with Cs131 provides excellent long-term bDFS, especially when compared to recently published RTOG 0938 as 47% of our patients had intermediate-risk disease (RTOG 0938 had low-risk disease only and only 5-year data). Our patients had modest changes in urinary and bowel QOL compared to baseline, also comparable to published SBRT data. At 5 years in our cohort, 46% and 41% reported improvement in their urinary and bowel EPIC scores. The reason for this needs to be explored.

Bayesian Estimation of Different Scale Parameters Using a LINEX Loss Function

The LINEX loss function, which climbs exponentially with one-half of zero and virtually linearly on either side of zero, is employed to analyze parameter analysis and prediction problems. It can be used to solve both underestimation and overestimation issues. This paper explained the Bayesian estimation of mean, Gamma distribution, and Poisson process. First, an improved estimator for μ 2 is provided (which employs a variation coefficient). Under the LINEX loss function, a better estimator for the square root of the median is also derived, and an enhanced estimation for the average mean in such a negatively exponential function. Second, giving a gamma distribution as a prior and a likelihood function as posterior yields a gamma distribution. The LINEX method can be used to estimate an estimatorλ B L ^ using posterior distribution. After obtainingλ B L ^ , the hazard functionh B L ^ andD B L ^ the function of survival estimators are used. Third, the challenge of sequentially predicting the intensity variable of a uniform Poisson process with a linear exponentially (LINEX) loss function and a constant cost of production time is investigated using a Bayesian model. The APO rule is offered as an approximation pointwise optimal rule. LINEX is the loss function used. A variety of prior distributions have already been studied, and Bayesian estimation methods have been evaluated against squared error loss function estimation methods. Finally, compare the results of Maximum Likelihood Estimation (MLE) and LINEX estimation to determine which technique is appropriate for such information by identifying the lowest Mean Square Error (MSE). The displaced estimation method under the LINEX loss function was also examined in this research, and an improved estimation was proposed.

Author Correction: Assessment of the cardioprotective effect of liraglutide on methotrexate induced cardiac dysfunction through suppression of inflammation and enhancement of angiogenesis in rats

Correction to: European Review for Medical and Pharmacological Sciences 2021; 25 (19): 6013-6024-DOI: 10.26355/eurrev_202110_26879-PMID: 34661261, published online on 15 October 2021. After publication, the authors applied to add some corrections to the paper. They wanted to change the second affiliation of one co-author Dr. Eman Said. The second affiliation will be "Department of Pharmacology and Toxicology, College of Pharmacy, Qassim University, Buraydah, Saudi Arabia", instead of "College of Pharmacy, Qassim University, Al-Qassim, Saudi Arabia". There are amendments to this paper. The Publisher apologizes for any inconvenience this may cause.  https://www.europeanreview.org/article/26879.

Assessment of the cardioprotective effect of liraglutide on methotrexate induced cardiac dysfunction through suppression of inflammation and enhancement of angiogenesis in rats

OBJECTIVE

Methotrexate (MTX) is one of the most commonly used anti-cancer drugs for various types of neoplasms. It is associated with multiple cytotoxic effects including nephrotoxicity, hepatotoxicity and cardiotoxicity. Liraglutide (LIR) is a potent anti-diabetic drug and also has antioxidant and anti-inflammatory properties. In this study, we tried to investigate the protective effect of LIR on MTX induced cardiotoxicity and to identify the molecular mechanisms for this protection.

MATERIALS AND METHODS

 Rats were divided into 4 groups, including control group, LIR group, MTX group and LIR + MTX group. ECG was measured then blood samples were taken, and hearts were excised for biochemical and histological investigations.

RESULTS

MTX group exhibited a mild non-significant irregular bradycardia, an increase of CK-MB besides a decrease of total antioxidant capacity. MTX administration also resulted in downregulation of vascular endothelial growth factor (VEGF), while caused upregulation of interleukin 1 beta (IL-1B) and interleukin 6 (IL-6) in comparison to the control group. Also, MTX group showed histological abnormalities besides negative VEGF and positive iNOS as detected by immunohistochemical staining compared to the control group. LIR administration could reverse these results.

CONCLUSIONS

LIR prevented MTX induced cardiotoxicity through its antioxidant and anti-inflammatory properties.

Cervical cancer screening uptake in Sub-Saharan Africa: a systematic review and meta-analysis

OBJECTIVES

The objective of this study is to estimate the pooled uptake of cervical cancer screening and identify its predictors in Sub-Saharan Africa.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

We searched PubMed, EMBASE, CINAHL, African Journals OnLine, Web of Science and Scopus electronic databases from January 2000 to 2019. All observational studies published in the English language that reported cervical cancer uptake and/or predictors in Sub-Saharan Africa were initially screened. We assessed methodological quality using the Newcastle-Ottawa Scale. An inverse variance-weighted random-effects model meta-analysis was performed to estimate the pooled uptake and odds ratio (OR) of predictors with a 95% confidence interval (CI). The I² test statistic was used to check between-study heterogeneity, and the Egger's regression statistical test was used to check publication bias.

RESULTS

We initially screened 3537 citations and subsequently 29 studies were selected for this review, which included a total of 36,374 women. The uptake of cervical cancer screening in Sub-Saharan Africa was 12.87% (95% CI: 10.20, 15.54; I² = 98.5%). A meta-analysis of seven studies showed that knowledge about cervical cancer increased screening uptake by nearly five times (OR: 4.81; 95% CI: 3.06, 7.54). Other predictors of cervical screening uptake include educational level, age, Human Immune deficiency Virus (HIV) status, contraceptive use, perceived susceptibility and awareness about screening locations.

CONCLUSIONS

Cervical screening uptake is low in Sub-Saharan Africa as a result of several factors. Health outreach and promotion programmes to target these identified predictors are required.

Ethnic differences in sedentary behaviour in 6-8-year-old children during school terms and school holidays: a mixed methods study

BACKGROUND

Sedentary behaviour (SB) in childhood is a major public health concern. Little is known about ethnic differences in SB during school and holiday weeks among White British (WB) and South Asian (SA) children, which this study aims to address through investigating inclinometer measured SB and exploring reasons for child engagement in SB.

METHODS

A mixed methods study, comprising of a quantitative investigation with 160, 6-8 years old children and a qualitative study with a subsample of 18 children, six parents and eight teachers was undertaken. Children of WB and SA ethnicity in three schools were invited to wear inclinometers for seven school terms (summer/winter/spring) and seven holidays (winter/spring) days during July 2016-May 2017. Total SB, SB accumulated in bouts > 30 min and breaks in SB were explored using multivariate linear mixed effects models which adjusted for wear time, sex, deprivation, overweight status, season, term, weekday and school. Nine focus groups and two interviews were carried out using the Theoretical Domains Framework to explore SB perceptions among parents, teachers and children. Data were analysed using the Framework Approach.

RESULTS

104/160 children provided 836 valid days of data. Children spent on average eight hours of SB/day during term time and holidays, equating to 60% of their awake time, and had on average 111 SB breaks /day. SA children had 25 fewer SB breaks/ day when compared to WB (p < 0.001). Perceived reasons for engagement in SB included: boredom, enjoyment of screen activities (by children), parenting practices, curriculum pressures (by teachers), the need to sit down and learn, and child's preference for screen activities (by parents).

CONCLUSIONS

Children spent 60% of their awake time being sedentary, regardless of ethnicity or school term. There were no significant ethnic differences for any of the SB outcomes except for breaks in SB. Interventions aimed at reducing SB should consider involving parents and teachers and should focus on increasing breaks in SB, especially for SA children, who are at a higher risk of cardio metabolic ill health.

Vitamin D attenuates gentamicin-induced acute renal damage via prevention of oxidative stress and DNA damage

Background:

Despite being one of the most nephrotoxic drugs, gentamicin (GM) remains a mainstay as a first-choice agent in a vast variety of clinical situations owing to its superlative efficiency as a broad-spectrum antibiotic in treating several life-threatening bacterial infections. This urgently calls for the need for in-depth analysis of the mechanisms governing GM-induced nephrotoxicity and entails the necessity of presenting novel protective agents capable of ameliorating those renal deleterious effects. The reactive oxygen species and redox-sensitive transcription factors in GM-induced nephrotoxicity have recently called attention.

Purpose:

This study has been designed to shed light on the possible mechanisms of GM-induced nephrotoxicity and to provide a consensus set of histopathological, immunohistochemical, genetic and biochemical parameters elucidating the protective role of vitamin D against this nephrotoxicity.

Methods:

Twenty-four adult male albino rats were equally divided into four groups: group I (control group), group II (GM), group III (GM + vitamin D) and group IV (vitamin D only). Kidney function tests, histopathological examination, gene expression of nuclear factor 2, nuclear factor kappa beta (NF-κB) and western blot of NF-κB p65, assessment of glutathione peroxidase and nicotinamide adenine dinucleotide phosphate oxidase (NADPH) oxidase by ELISA, as well as immunohistochemical evaluation of inducible nitric oxide, malondialdehyde, 8-hydroxy 2 deoxyguanine and vitamin D receptor, have been carried out.

Results:

The kidney function deterioration, tissue oxidative stress development and the histopathological changes induced by GM were significantly attenuated by vitamin D administration.

Conclusion:

Vitamin D attenuates GM nephrotoxicity through its antioxidant properties and prevention of DNA damage.

Effect of Caffeine on Serum Tumour Necrosis Factor Alpha and Lactate Dehydrogenase in Wistar Rats Exposed to Cerebral Ischaemia-reperfusion Injury

Caffeine is known to confer neuro-protection via A1 and A2A adenosine receptor antagonism in which adenosine neuro-modulates excitotoxic release of glutamate. Currently, it is unclear whether caffeine modulates inflammation in ischaemic stroke model. The present study examined effects of caffeine following ischaemia-reperfusion injury on neuro-inflammatory tumour necrosis alpha (TNF-α), lactate dehydrogenase (LDH), as well as effect of caffeine against brain ischaemic damage on histology. Thirty three adult male Wistar rats (180-300 g) were used in this study. They were randomly divided into four groups (n=5 each): Group I (Control) that received neither the operation nor any treatment; Group II (Sham/Water) received a pseudo-ischaemic-reperfusion and 1ml water for injection; Group III (BCCO/Water) that received complete bilateral common carotid occlusion (BCCO) and 1ml water for injection; Group IV (BCCO/Caffeine) that received complete BCCO and caffeine solution intraperitoneally at a dose of 50% LD50 value (144mg/kg); and thirteen rats were used for LD50 assessment. Sensory and motor functions significantly (p<0.05) decreased in the rat following ischaemia-reperfusion injury when compared to pre-injury state on Garcia neurological score. Caffeine reduced brain ischaemic injury and significantly reduced (p<0.05) TNF-α activity. While no significant effects (p>0.05) of caffeine was observed on LDH activity. This study has shown neuro-protective roles of caffeine against ischaemia-reperfusion damage to brain tissue, inflammatory TNF-α activity, but not on LDH activity.

The learning curve to achieve satisfactory completion rates in upper GI endoscopy: an analysis of a national training database

OBJECTIVE

The aim of this study was to determine the number of OGDs (oesophago-gastro-duodenoscopies) trainees need to perform to acquire competency in terms of successful unassisted completion to the second part of the duodenum 95% of the time.

DESIGN

OGD data were retrieved from the trainee e-portfolio developed by the Joint Advisory Group on GI Endoscopy (JAG) in the UK. All trainees were included unless they were known to have a baseline experience of >20 procedures or had submitted data for <20 procedures. The primary outcome measure was OGD completion, defined as passage of the endoscope to the second part of the duodenum without physical assistance. The number of OGDs required to achieve a 95% completion rate was calculated by the moving average method and learning curve cumulative summation (LC-Cusum) analysis. To determine which factors were independently associated with OGD completion, a mixed effects logistic regression model was constructed with OGD completion as the outcome variable.

RESULTS

Data were analysed for 1255 trainees over 288 centres, representing 243 555 OGDs. By moving average method, trainees attained a 95% completion rate at 187 procedures. By LC-Cusum analysis, after 200 procedures, >90% trainees had attained a 95% completion rate. Total number of OGDs performed, trainee age and experience in lower GI endoscopy were factors independently associated with OGD completion.

CONCLUSIONS

There are limited published data on the OGD learning curve. This is the largest study to date analysing the learning curve for competency acquisition. The JAG competency requirement for 200 procedures appears appropriate.

Using routine blood test results to predict the risk of death for emergency medical admissions to hospital: an external model validation study

BACKGROUND

The Biochemistry and Haematology Outcome Model (BHOM) relies on the results from routine index blood tests to predict the patient risk of death. We aimed to externally validate the BHOM model.

METHOD

We considered all emergency adult medical patients who were discharged from Northern Lincolnshire and Goole (NLAG) hospital in 2014. We compared patient characteristics between NLAG (the validation sample) and the hospital where BHOM was developed. We evaluated the predictive performance, according to discriminative ability (with a concordance statistic, c), and calibration (agreement between observed and predicted risk).

RESULT

There were 29 834 emergency discharges of which 24 696 (83%) had complete data. In comparison with the development sample, the NLAG sample was similar in age, blood test results, but experienced a lower mortality (4.7 vs. 8.7%). When applied to NLAG, the BHOM model had good discrimination (c-statistic 0.83 [95% CI 0.823-0.842]). Calibration was good overall, although the BHOM model overpredicted for lowest (<5%, observed = 229, predicted = 286) and highest (≥50%, observed = 31, predicted = 49) risk groups, even after recalibrating for the differences in baseline risk of death.

CONCLUSION

Differences in patient case-mix profile and baseline risk of death need to be considered before the BHOM model can be used in another hospital. After re-calibrating for the baseline difference in risk the BHOM model had good discrimination but less adequate calibration.

Use of a pathway quality improvement care bundle to reduce mortality after emergency laparotomy

Background

Emergency laparotomies in the UK, USA and Denmark are known to have a high risk of death, with accompanying evidence of suboptimal care. The emergency laparotomy pathway quality improvement care (ELPQuiC) bundle is an evidence-based care bundle for patients undergoing emergency laparotomy, consisting of: initial assessment with early warning scores, early antibiotics, interval between decision and operation less than 6 h, goal-directed fluid therapy and postoperative intensive care.

Methods

The ELPQuiC bundle was implemented in four hospitals, using locally identified strategies to assess the impact on risk-adjusted mortality. Comparison of case mix-adjusted 30-day mortality rates before and after care-bundle implementation was made using risk-adjusted cumulative sum (CUSUM) plots and a logistic regression model.

Results

Risk-adjusted CUSUM plots showed an increase in the numbers of lives saved per 100 patients treated in all hospitals, from 6·47 in the baseline interval (299 patients included) to 12·44 after implementation (427 patients included) (P < 0·001). The overall case mix-adjusted risk of death decreased from 15·6 to 9·6 per cent (risk ratio 0·614, 95 per cent c.i. 0·451 to 0·836; P = 0·002). There was an increase in the uptake of the ELPQuiC processes but no significant difference in the patient case-mix profile as determined by the mean Portsmouth Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity risk (0·197 and 0·223 before and after implementation respectively; P = 0·395).

Conclusion

Use of the ELPQuiC bundle was associated with a significant reduction in the risk of death following emergency laparotomy.

The findings of the Mid-Staffordshire Inquiry do not uphold the use of hospital standardized mortality ratios as a screening test for 'bad' hospitals

The Mid-Staffordshire Public Inquiry has published its findings. The initial investigations were triggered by an elevated hospital standardized mortality ratio (HSMR). This shows that the HSMR is being used as a screening test for substandard care; whereby hospitals that fail the test are scrutinized, whilst those that pass the test are not. But screening tests are often misunderstood and misused and so it is prudent to critically examine the HSMR before casting it in the role of a screening test for 'bad' hospitals. A screening test should be valid, have adequate performance characteristics and a clear post-test action plan. The HSMR is not a valid screening test (because the empirical relationship between clinically avoidable mortality and the HSMR is unknown). The HSMR has a poor performance profile (10 of 11 elevated HSMRs would be false alarms and 10 of 11 poorly performing hospitals would escape attention). Crucially, the aim of a post-test investigation into an elevated HSMR is unclear. The use of the HSMR as a screening test for clinically avoidable mortality and thereby substandard care, although well intentioned, is seriously flawed. The findings of the Mid-Staffordshire Public Inquiry have no bearing on this conclusion because a 'bad' hospital cannot uphold a bad screening test. Nonetheless, HSMRs continue to pose a grave public challenge to hospitals, whilst the unsatisfactory nature of the HSMR remains a largely unacknowledged and unchallenged private affair. This asymmetric relationship is inappropriate, unhelpful, costly and potentially harmful. The use of process measures remains a valid way to measure quality of care.

Prevalence and associated risk factors of male erectile dysfunction among patients on hemodialysis and kidney transplant recipients: a cross-sectional survey from Sudan

Male erectile dysfunction (ED) is an important issue worldwide occurring in 5-69% of men in community-based studies. It is more common in patients with chronic kidney disease (CKD) and those on peritoneal as well as hemodialysis (HD), occurring in more than 80% of patients. In Sudan, there is no previous report on ED among patients with CKD. A cross-sectional study was done to determine the prevalence of ED and its associated risk factors among Sudanese CKD patients on HD and those who underwent renal transplant. This was conducted in Khartoum, Sudan from October 2005 to July 2006 including all married men who were on maintenance HD for more than three months and all married men who had received renal transplantation at least three months earlier. Single, divorced/separated men, those whose wives were living away, those who were bed-bound and those with cognitive impairment were also excluded. After obtaining consent for participation, demographic and clinical data were collected by using anonymous questionnaires and the Arabic version of International Index of Erectile Function (IIEF; the Egyptian version). Patients who did not participate in full and proper manner were considered as "non-responders." A total of 146 patients, 106 HD patients, and 40 renal transplant recipients completed the IIEF questionnaire. Non-responders constituted 43.7% and 54.5% of HD and transplant recipient patients, respectively. Blood samples were taken after completion of the IIEF questionnaire to determine the required investigations. ED prevalence was high among our study patients, 83% among the HD patients and 67.5% among the renal transplant recipients. Univariate analysis showed that there was a trend, although non-significant, of older age being associated with ED in both groups. Similar association was seen in those who were under-dialyzed in the HD group and DM in the transplant recipient group. Previous history of ED was significantly associated with current presence of ED in both groups. More studies with larger sample size are needed to clarify the results of this study.

Plotting basic control charts: tutorial notes for healthcare practitioners

There is considerable interest in the use of statistical process control (SPC) in healthcare. Although SPC is part of an overall philosophy of continual improvement, the implementation of SPC usually requires the production of control charts. However, as SPC is relatively new to healthcare practitioners and is not routinely featured in medical statistics texts/courses, there is a need to explain the issues involved in the selection and construction of control charts in practice. Following a brief overview of SPC in healthcare and preliminary issues, we use a tutorial-based approach to illustrate the selection and construction of four commonly used control charts (xmr-chart, p-chart, u-chart, c-chart) using examples from healthcare. For each control chart, the raw data, the relevant formulae and their use and interpretation of the final SPC chart are provided together with a notes section highlighting important issues for the SPC practitioner. Some more advanced topics are also mentioned with suggestions for further reading.

Natural and experimental nodular dermatomycosis in chickens

The occurrence of unusual cases of generalised, tumour-like cutaneous swellings in 2-3-month-old chickens, from which A. flavus or C. albicans could be isolated, is described. Histologically similar but clinically different lesions could be produced experimentally in 1-month-old chickens by intradermal inoculation of A. flavus alone or combined with C. albicans. The latter organism alone failed, however, to produce the cutaneous lesions by the same route of inoculation. Intracardiac inoculation of A. flavus into chickens of the same age resulted in a systemic infection, including the nervous tissue, but without apparent involvement of the skin.

National audit of the sensitivity of double-contrast barium enema for colorectal carcinoma, using control charts

AIM

To audit the sensitivity of double-contrast barium enema (DCBE) for colorectal carcinoma, as currently practised in UK departments of radiology.

METHODS

As part of its programme of national audits, the Royal College of Radiologists Clinical Radiology Audit Sub-Committee undertook a retrospective audit of the sensitivity of DCBE for colorectal carcinoma during 2002. The following targets were set: demonstration of a lesion > or =95%; correct identification as a carcinoma > or =90%.

RESULTS

Across the UK, 131 departments took part in the audit, involving 5454 examinations. The mean demonstration rate was 92.9% and the diagnosis rate was 85.9%, slightly below the targets set. The equivocal rate (lesion demonstrated, but not defined as malignant) was 6.9%, the perception failure rate was 2.8% and the technical failure rate was 4.4%. Control-chart methodology was used to analyze the data and to identify any departments whose performance was consistent with special-cause variation.

CONCLUSION

When compared with the diagnosis rate (84.6%) and demonstration rate (92.7%) reported in the Wessex Audit 1995, [Thomas RD, Fairhurst JJ, Frost RA. Wessex regional audit: barium enema in colo-rectal carcinoma. Clin Radiol 1995;50:647-50.] a similar level of performance was observed in the NHS today, implying that the basic process for undertaking and reporting DCBE has remained relatively unchanged over the last few years. Improvement in the future will require fundamental changes to the process of reporting DCBE, in order to minimize the perception failure rate and accurately to describe lesions, so reducing the equivocal rate. Control-chart methodology has a useful role in identifying strategies to deliver continual improvement.

The measurement of active errors: methodological issues

The value of research in any topic area turns on its validity. Patient safety research has revealed--or, at least, given renewed urgency to--a raft of methodological issues. The meaning and thus the value of empirical research in this field is contingent on getting the methodology right. The need for good methods for the measurement of error is necessary whenever an inference is intended and, since inferences lie at the heart of research and management, there is a huge need to understand better how to make measurements that are meaningful, precise, and accurate. In this paper we consider issues relating to the measurement of error and the need for more research.

Bristol, Shipman, and clinical governance: Shewhart's forgotten lessons

During the past century, manufacturing industry has achieved great success in improving the quality of its products. An essential factor in this success has been the use of Walter A Shewhart's pioneering work in the economic control of variation, which culminated in the development of a simple yet powerful graphical method known as the control chart. This chart classifies variation as having a common cause or special cause and thus guides the user to the most appropriate action to effect improvement. Using six case studies, including the excess deaths after paediatric cardiac surgery seen in Bristol, UK, and the activities of general practitioner turned murderer Harold Shipman, we show a central role for Shewhart's approach in turning the rhetoric of clinical governance into a reality.

Oxygen and 99mTc-MAA shunt estimations in patients with pulmonary arteriovenous malformations: effects of changes in posture and lung volume

BACKGROUND

Patients with arteriovenous malformations are routinely monitored with arterial oxygen saturation (SaO2) estimations (breathing air) from which an oxygen shunt fraction can be calculated. This simple estimation has been compared with an anatomically defined estimate of the right to left shunt using a radioisotopic method. The fall in SaO2 which occurs in patients with pulmonary arteriovenous malformations in the erect posture and at high lung volumes was used to test the ability of SaO2 alone to follow changes in right to left shunt.

METHODS

Radiolabelled albumin macroaggregates (99mTc-MAA) or microspheres (MS) were injected intravenously and kidneys and lungs were imaged. The shunt fraction (QS/QTTc) in the supine position at functional residual capacity (baseline) was obtained by quantifying right kidney radioactivity. On standing or while breath holding at total lung capacity, shunt fraction was calculated from baseline QS/QTTc and from lung counts and the injected dose. Arterial oxygen saturation (SaO2) was recorded by a pulse oximeter for calculation of the oxygen shunt (QS/QTO2) (breathing air).

RESULTS

In the postural study (n = 8) SaO2 decreased from a mean (SD) value of 89 (5)% supine to 80 (6)% erect, corresponding to QS/QTO2 28 (8)% and 44 (8)% respectively. QS/QTTc increased from 28.7 (10.3)% to 39 (14.3)%. In the lung volume study (n = 8) QS/QTTc increased from 16.6 (11.5)% at functional residual capacity to 23.3 (11.9)% at total lung capacity while QS/QTO2 increased from 19.5 (7.5)% to 25.9 (10.6)% respectively. When all measurements were compared for QS/QTTc% and QS/QTO2% (n = 32) the difference in the mean values was 2.5% (absolute) and the limits of agreement between the two methods were +38% to -18% (relative). In neither the postural nor the volume study did delta (QS/QTO2) reliably predict delta (QS/QTTc)%.

CONCLUSIONS

In pulmonary arteriovenous malformations the simple physiological shunt calculated from SaO2 breathing air agreed well with the anatomical right to left shunt measured with 99mTc-MAA, but predicted poorly the changes in anatomical shunt induced by postural or lung volume changes.

Experimental study of contagious paralysis of pigeons

A study of the clinical and pathological changes in pigeons experimentally inoculated with a herpesvirus isolated recently from natural cases of a condition termed contagious paralysis was carried out. Signs and pathological findings similar to those recorded in natural cases were produced after inoculation of the isolate via different routes. The incubation period differed according to the route of inoculation from 2 to 10 days and the course of the disease from 5 to 21 days. The mortality ranged from 100% in the intracerebrally inoculated pigeons to 61% in the orally infected ones. The clinical signs and the gross and histopathological changes included mainly progressive paralysis, meningo-encephalomyelitis, pancreatitis and sometimes enteritis.