The Icatibant Outcome Survey: 10 years of experience with icatibant for patients with hereditary angioedema

In patients with hereditary angioedema (HAE), bradykinin causes swelling episodes by activating bradykinin B₂ receptors. Icatibant, a selective bradykinin B₂ receptor antagonist, is approved for on-demand treatment of HAE attacks. The Icatibant Outcome Survey (IOS; NCT01034969) is an ongoing observational registry initiated in 2009 to monitor effectiveness/safety of icatibant in routine clinical practice. As of March 2019, 549 patients with HAE type 1 or 2 from the IOS registry had been treated, for 5995 total attacks. This article reviews data published from IOS over time which have demonstrated that effectiveness of icatibant in a real-world setting is comparable to efficacy in clinical trials; one dose is effective for the majority of attacks; early treatment (facilitated by self-administration) leads to faster resolution and shorter attack duration; effectiveness/safety of icatibant has been shown across a broad range of patient subgroups, including children/adolescents and patients with HAE with normal C1 inhibitor levels; and tolerability has been demonstrated in patients aged ≥65 years. Additionally, this review highlights how IOS data have provided valuable insights into patients' diagnostic journeys and treatment behaviors across individual countries. Such findings have helped to inform clinical strategies and guidelines to optimize HAE management and limit disease burden. This research was sponsored by Takeda Development Center Americas, Inc. Takeda Development Center Americas, Inc., provided funding to Excel Medical Affairs for support in writing and editing this manuscript.

Variability of disease activity in patients with hereditary angioedema type 1/2: longitudinal data from the Icatibant Outcome Survey

BACKGROUND

Hereditary angioedema due to C1 inhibitor deficiency (HAE-1/2) is a chronic and debilitating disease. The unpredictable clinical course represents a significant patient burden.

OBJECTIVE

To analyse longitudinal registry data from the Icatibant Outcome Survey (IOS) in order to characterize temporal changes in disease activity in patients with HAE-1/2.

METHODS

Icatibant Outcome Survey (NCT01034969) is an international observational registry monitoring the clinical outcomes of patients eligible for icatibant treatment. The current analyses are based on data collected between July 2009 and July 2019. Retrospective data for attacks recorded in the 12 months prior to IOS enrolment and for each 12-month period up to 7 years were analysed.

RESULTS

Included patients reported angioedema attacks without long-term prophylaxis (LTP; n = 315) and with LTP (n = 292) use at the time of attack onset. Androgens were the most frequently used LTP option (80.8%). At the population level, regardless of LTP use, most patients (52-80%) reporting <5 attacks in Year 1 continued experiencing this rate; similarly, many patients (25-76%) who reported high attack frequency continued reporting ≥10 attacks/year. However, year on year, 31-51% of patients experienced notable changes (increase/decrease of ≥5 attacks) in annual attack frequency. Of patients who reported an absolute change of ≥10 attacks from Year 1 to 2, 17-50% continued to experience a change of this magnitude in subsequent years.

CONCLUSION

At the population level, attack frequency was generally consistent over 7 years. At the small group level, 28.8-34.5% of patients reported a change in attack frequency of ≥5 attacks from Year 1 to Year 2; up to half of these patients continued to experience this magnitude of variation in disease activity in later years, reflecting high intra-patient variability.

Adult liver transplant for hepatocellular carcinoma at Wits Donald Gordon Medical Centre in Johannesburg, South Africa

BACKGROUND

For those with unresectable hepatocellular carcinoma, liver transplantation is considered the treatment of choice. Since 2006, the transplant programme at Wits Donald Gordon Medical Centre (WDGMC) has offered liver transplantation for selected patients with hepatocellular carcinoma. While the number of patients transplanted was small, we are unaware of any published data from Southern Africa describing outcomes in this group of liver transplant recipients. The aim of this study was to describe our experience as a case series.

METHODS

The records of all patients with HCC who underwent deceased donor liver transplantation between April 2006 and March 2018 were reviewed retrospectively. Data were extracted from transplant clinic patient files, histopathology and pathology laboratory reports and an existing database of all liver transplant recipients at WDGMC. Patient survival was calculated from the time of transplant and survival estimates were determined by the Kaplan-Meier method.

RESULTS

Thirty-one liver transplants were reviewed. The most common causes of underlying liver disease were infectious, mostly hepatitis B virus, and diseases of lifestyle including alcoholic/non-alcoholic steatohepatitis. Median age at transplant, 57 years (IQR 44-65 years), was younger than observed internationally, but consistent with reports from Africa. Male recipients predominated, in keeping with published trends. Overall, outcomes were worse than expected but for recipients who were within the University of California at San Francisco (UCSF) criteria for transplantation; survival was comparable to previously published data.

CONCLUSION

Despite limitations, this is the first documented series of patients undergoing liver transplantation for HCC in South Africa and demonstrates that good results can be achieved in appropriately selected patients.

Living donor liver transplantation in South Africa: the donor experience

BACKGROUND

Living donor liver transplantation (LDLT) plays a crucial role in liver transplant programmes, particularly in regions with a scarcity of deceased donor organs and especially for paediatric recipients. LDLT is a complex and demanding procedure which places a healthy living donor in harm's way. Donor safety is therefore the overriding concern. This study aimed to report our standardised approach to the evaluation, technical aspects and outcomes of LDLT donor hepatectomy at Wits Donald Gordon Medical Centre.

METHOD

The study population consisted of all patients undergoing LDLT donor hepatectomy since the inception of the programme in March 2013 until 2018. Sixty five living donor hepatectomies were performed. Primary outcome measures included donor demographics, operative time, peak bilirubin, aspartate and alanine transaminase levels postoperatively, length of hospital stay and postoperative complications using the Clavien-Dindo classification.

RESULTS

The majority of the donors were female, most were parents with mothers being the donor almost 85% of the time. The median operative time was 374 minutes with a downward trend over time as experience was gained. The median length of hospital stay was 7 days. There was no mortality and the complication rate was 30% with the majority being minor (Grade 1).

CONCLUSION

Living donor liver transplant from adult-to-child has been successfully initiated in South Africa. Living donor hepatectomy can be safely performed with acceptable outcomes for the donor. Wait-list mortality however remains unacceptably high. Expansion of LDLT as well as real change in deceased donor policy is required to address this issue.

Outcomes of paediatric liver transplant for biliary atresia

BACKGROUND

Despite the widespread use of Kasai Portoenterostomy (KPE) for biliary atresia, more than two thirds of these patients require liver transplant. Liver transplantation is not widely available in South Africa, and Wits Donald Gordon Medical Centre is one of two centres performing paediatric liver transplantation in the country, and the only centre performing living related donor transplants.

METHOD

A retrospective review was performed at the centre. Demographic data were collected, and tabulated. Survival analysis was performed using the Kaplan Meier method. Complication rates were categorised into biliary, vascular and enteric, and classified as early and late.

RESULTS

Sixty-seven first time liver transplants were performed for biliary atresia at WDGMC from 2005 to 2017. Sixty-nine percent were female patients and thirty-one percent were male patients. Forty-eight percent of patients under the age of 5 years had a z-score of -2 or worse for mid upper arm circumference (MUAC). One year overall survival of the cohort is 84.5%, and overall graft survival is 82.9%. Overall mortality was 22%, with infection being the most common cause of death.

CONCLUSION

Early referral of all patients with biliary atresia to a paediatric liver transplant centre is essential for early assessment of indications, and medical and nutritional optimisation of patients. Primary liver transplant should be considered for a select group of patients with unique clinical indications.

Commercial Low-citrate Anticoagulation Haemofiltration in High Risk Patients with Frequent Filter Clotting

This study assessed the safety and efficacy of a commercial low-citrate concentration-based pre-filter replacement fluid during continuous veno-venous haemofiltration (CVVH) in patients with frequent filter clotting and high risk of bleeding. We used a commercial low-citrate fluid as pre-dilution replacement fluid during CVVH (citrate: 11 mmol/l (33 meq/l), sodium: 140 mmol/l, chloride: 108 mmol/l and potassium: 1 mmol/l). A calcium and magnesium infusion was delivered separately by central line for the maintenance of serum ionized calcium (Cai) and total magnesium (Mg). In this prospective observational study, 30 patients, 124 filters and 1,515 treatment-hours were observed. Median filter life of citrate CVVH was 9.5 hours. Filter life in the 48 hours prior to citrate CVVH was also observed. In the patients on prior non-anticoagulant CVVH (n=14) filter life increased significantly with citrate (9.5 hours vs 5 hours; P<0.0001). In patients on prior heparin CVVH (n=15), filter life was similar with citrate (10 hours vs 8 hours; P=0.68). However, in patients with prior early/frequent filter clotting despite heparin (n=11) filter life increased significantly (10 hours vs 7 hours; P=0.038). Of 411 serum Cai measurements, none showed a Cai<0.85 mmol/l and, of 84 observations, none showed a serum Mg<0.6mmol/l. One patient with sepsis and shock needed to cease citrate CVVH because of progressive ionized hypocalcaemia and increasing anion gap. No other adverse effects were observed. In selected patients, CVVH with a commercial low-citrate concentration solution as pre-filter replacement fluid and a simultaneous calcium and magnesium infusion protocol appears generally safe. Filter life was acceptable and superior to that achieved with previous treatment.

Management of patients with hereditary angioedema in Germany: comparison with other countries in the Icatibant Outcome Survey

Background

The Icatibant Outcome Survey (IOS; NCT01034969) is a Shire‐sponsored, international, observational study monitoring the safety and effectiveness of icatibant, a bradykinin B2 receptor antagonist approved for the acute treatment of adults with hereditary angioedema with C1 inhibitor deficiency (HAE‐C1‐INH).

Objective

To report IOS data comparing demographic and icatibant treatment outcomes in patients with HAE‐C1‐INH from Germany to HAE‐C1‐INH patients from 11 other IOS countries.

Methods

A descriptive, retrospective, comparative analysis of data from 685 IOS patients with HAE‐C1‐INH from seven centres in Germany (n = 93) vs. centres from Austria, Brazil, Czech Republic, Denmark, France, Greece, Israel, Italy, Spain, Sweden and the United Kingdom (n = 592, July 2009–January 2017). Icatibant treatment outcomes were retrieved from patients with complete attack outcome data for time to treatment, time to resolution and attack duration (160 attacks in 42 German patients and 1442 attacks in 251 patients from other IOS countries).

Results

German patients reported significantly fewer severe/very severe attacks (38.7% vs. 57.5%, respectively; P < 0.001). The proportion of attacks treated with a single icatibant injection was significantly higher in German patients (97.1% vs. 91.6%, P = 0.0003). The median time to treatment (0.0 h vs. 1.5 h), time to resolution (3.0 h vs. 7.0 h) and attack duration (4.3 h vs. 10.5 h) in German patients vs. other IOS countries were all significantly shorter (all P < 0.0001). No meaningful differences were identified between patients from Germany and other countries with regard to sex, median age at enrolment, median age at symptom onset and median age at diagnosis.

Conclusion

German IOS patients share similar demographic characteristics to patients from other IOS countries yet treat their attacks with icatibant significantly earlier and have markedly fewer severe or very severe attacks. Factors including regional access to and availability of icatibant may drive these outcomes and warrant further investigation.

Surgery for portal hypertension in children: A 12-year review

BACKGROUND

Portal hypertension is a common and potentially devastating condition in children. Notwithstanding advances in the nonsurgical management of portal hypertension, surgery remains an important treatment modality in select patients. We report here on our experience in the past 12 years.

OBJECTIVES

To describe the profile of, indication for, and complications of shunt surgery in children with portal hypertension.

METHODS

Twelve children underwent shunt surgery between 2005 and 2017. Patient records were reviewed.

RESULTS

Fourteen procedures were performed on 12 patients during the study period. The median age at surgery was 6.5 (range 1 - 18) years. Six patients were male. Gastrointestinal bleeding that was not amenable to endoscopic control was the most common indication for surgery. Portal vein thrombosis was the most common cause of portal hypertension in our series (n=11). Two-thirds (8/12) of all patients had an identifiable underlying risk factor for portal vein thrombosis. One-third of all patients (4/12) underwent a meso-portal bypass procedure (Rex shunt), while 58% (7/12) were managed with a distal splenorenal shunt. All patients received postoperative thromboprophylaxis. We experienced a single mortality, 1 patient experienced shunt thrombosis that required revision shunt surgery, and 2 patients experienced anastomotic strictures, with one being managed with revision surgery and the other currently awaiting radiological venoplasty.

CONCLUSIONS

Surgery is a safe and important tool in the management of children with non-cirrhotic portal hypertension and those with sufficient hepatic reserve who fail to respond to more conservative methods for the treatment of side effects of portal hypertension.

The limitations in implementing and operating a rapid response system

Despite the widespread introduction of rapid response systems (RRS)/medical emergency teams (MET), there is still controversy regarding how effective they are. While there are some observational studies showing improved outcomes with RRS, there are no data from randomised controlled trials to support the effectiveness. Nevertheless, the MET system has become a standard of care in many healthcare organisations. In this review, we present an overview of the limitations in implementing and operating a RRS in modern healthcare.

Interpreting diaphragmatic movement with bedside imaging, review article

The diaphragm is the most important muscle of respiration. At equilibrium, the load imposed on the diaphragmatic muscles from transdiaphragmatic pressure balances the force generated by diaphragmatic muscles. However, procedural and nonprocedural thoracic and abdominal conditions may disrupt this equilibrium and impair diaphragmatic function. Diaphragmatic dysfunction is associated with respiratory insufficiency and poor outcome. Therefore, rapid diagnosis and early intervention may be useful. Ultrasound imaging provides quick and accurate bedside assessment of the diaphragm. Various imaging techniques have been suggested, using 2-dimensional and M-mode technology. Diaphragm viewing depends on the degree of robe movement, determined by the angle of incidence of the ultrasound beam and by the direction of probe movement. In this review, we will discuss the function of the diaphragm focusing on clinically important anatomical and physiological properties of the diaphragm. We will review the literature regarding various sonographic techniques for diaphragm assessment. We will also explore the evidence for the role of the tidal displacement of subdiaphragmatic organs as a surrogate for diaphragm movement.

Heterozygote to homozygote related living donor liver transplantation in maple syrup urine disease: a case report

Liver transplantation is an accepted treatment modality in the management of MSUD. To our knowledge, ours is only the second successful case to date of a patient with MSUD receiving an allograft from an RLD who is a heterozygous carrier for the disease. In view of the worldwide shortage of available organs for transplantation, heterozygote to homozygote transplantation in the setting of MSUD may provide a viable alternative for those awaiting transplantation. We report on the case of a two-yr-old infant with MSUD, who received a left lateral segment (segments II and III) liver transplant from his mother, a heterozygote carrier of one of the three abnormal genes implicated in MSUD. Post-operative BCAA levels normalized in our patient and remained so on an unrestricted protein diet and during times of physiological stress. To date, this is only the second case of a successful RLD liver transplant in a child with MSUD. Preliminary results indicate that RLD liver transplants are at least equivalent to deceased donor liver transplants in the treatment of MSUD, although longer term follow-up is required. Heterozygote to homozygote RLD transplant in patients with MSUD presents a new pool of potential liver donors.

Paediatric liver transplantation for children treated at public health facilities in South Africa: time for change

Paediatric liver transplantation (PLT) is the only therapeutic option for many children with end-stage chronic liver disease or irreversible fulminant hepatic failure, and is routinely considered as a therapy by paediatric gastroenterologists and surgeons working in developed countries. In South Africa (SA), a PLT programme has been available at Red Cross War Memorial Children's Hospital in Cape Town since November 1991, and another has rapidly developed at the Wits Donald Gordon Medical Centre in Johannesburg over the past decade. However, for most children with progressive chronic liver disease who are reliant on the services provided at state facilities in SA, PLT is not an option because of a lack of resources in a mismanaged public health system. This article briefly outlines the services offered at Chris Hani Baragwanath Academic Hospital--which is typical of state facilities in SA--and proposes that resources be allocated to establish an innovative, nationally funded centre that would enable greater numbers of children access to a PLT programme.

Structural vascular disease in Africans: Performance of ethnic-specific waist circumference cut points using logistic regression and neural network analyses: The SABPA study

A recently proposed model for waist circumference cut points (RPWC), driven by increased blood pressure, was demonstrated in an African population. We therefore aimed to validate the RPWC by comparing the RPWC and the Joint Statement Consensus (JSC) models via Logistic Regression (LR) and Neural Networks (NN) analyses. Urban African gender groups (N=171) were stratified according to the JSC and RPWC cut point models. Ultrasound carotid intima media thickness (CIMT), blood pressure (BP) and fasting bloods (glucose, high density lipoprotein (HDL) and triglycerides) were obtained in a well-controlled setting. The RPWC male model (LR ROC AUC: 0.71, NN ROC AUC: 0.71) was practically equal to the JSC model (LR ROC AUC: 0.71, NN ROC AUC: 0.69) to predict structural vascular -disease. Similarly, the female RPWC model (LR ROC AUC: 0.84, NN ROC AUC: 0.82) and JSC model (LR ROC AUC: 0.82, NN ROC AUC: 0.81) equally predicted CIMT as surrogate marker for structural vascular disease. Odds ratios supported validity where prediction of CIMT revealed -clinical -significance, well over 1, for both the JSC and RPWC models in African males and females (OR 3.75-13.98). In conclusion, the proposed RPWC model was substantially validated utilizing linear and non-linear analyses. We therefore propose ethnic-specific WC cut points (African males, ≥90 cm; -females, ≥98 cm) to predict a surrogate marker for structural vascular disease.

Effect of anti-IL-1β antibody (canakinumab) on insulin secretion rates in impaired glucose tolerance or type 2 diabetes: results of a randomized, placebo-controlled trial

AIMS

Evaluate anti-interleukin-1β (IL-1β) antibody, canakinumab, in patients with type 2 diabetes and impaired glucose tolerance (IGT) in whom hyperglycaemia may trigger IL-1β-associated inflammation leading to suppressed insulin secretion and β-cell dysfunction.

METHODS

This 4-week, parallel-group study randomized 190 patients with type 2 diabetes 2 : 1, canakinumab versus placebo, into the following treatment arms: metformin monotherapy, metformin + sulfonylurea, metformin + sulfonylurea + thiazolidinedione or insulin ± metformin. IGT population (n = 54) was randomized 1 : 1, canakinumab versus placebo. Primary efficacy assessment was change from baseline in insulin secretion rate (ISR) relative to glucose 0-2 h.

RESULTS

Mean changes from baseline to week 4 in ISR relative to glucose at 0-2 h or other time points were not statistically significant for canakinumab versus placebo across groups. ISR (relative to glucose) at 0-0.5 h (first-phase insulin secretion) numerically favoured canakinumab versus placebo in insulin-treated patients {difference in mean change from baseline [point estimate (PE)] 3.81 pmol/min/m(2)/mmol/l; p = 0.0525} and in the IGT group (PE 3.92 pmol/min/m(2)/mmol/l; p = 0.1729). Mean change from baseline in fasting plasma glucose favoured canakinumab in the type 2 diabetes/metformin group and the IGT group; however, differences were not statistically significant. Mean change from baseline in peak insulin level and insulin AUC 0-4 h were statistically significantly higher in the canakinumab group in IGT patients. Canakinumab was well tolerated and consistent with known safety experience.

CONCLUSIONS

The trend towards improving ISR relative to glucose 0-0.5 h in patients treated with insulin supports the hypothesis that insulin secretion can be improved by blocking IL-1β.

Incidence, risk factors, and outcomes associated with cytomegalovirus disease in small bowel transplant recipients

Despite improved prophylaxis, monitoring, and more efficient immunosuppression, CMV infection remains a common opportunistic infection in transplant recipients. We assessed the incidence of CMV disease in pediatric SBT recipients, the timing of CMV disease after transplantation, and its impact on patient outcome. The medical records of 98 SBT recipients were reviewed. We performed descriptive analysis, regression analysis, and Kaplan-Meier curves to determine the time-to-event after transplantation. Fifty-three percent patients were male and 47% female, with a mean age of 38.3 months. Thirty-five percent of patients received prophylactic VGC, 55% GCV, 10% a combination of GCV/VGC, and 99% CMV immunoglobulins. A total of 24.5% recipients were CMV D+/R- (CMV serostatus donor positive/recipient negative). Seven (c. 7%) patients developed CMV disease. CMV disease was associated with 2.5 times (0.52-12.1; p = 0.25) higher rate of CMV mismatch and 11.1 times (1.3-95.9; p = 0.03) higher risk of death. CMV prophylaxis increased time-to-death (p = 0.074). Time-to-CMV disease was shorter in patients with enteritis (p < 0.0001), and CMV disease was associated with shorter time-to-death after transplantation (p = 0.001). CMV disease in SBT recipients was associated with an 11-fold mortality increase and a fourfold faster time-to-death. Time-to-death was significantly shorter with CMV enteritis.

Paediatric liver transplantation in Johannesburg: initial 29 cases and prospects for the future

BACKGROUND

The Wits Donald Gordon Medical Centre paediatric liver transplant programme is the second such unit in sub-Saharan Africa. Initiated in November 2005, it forms part of the centre's solid organ transplant unit, comprising kidney, liver and simultaneous kidney-pancreas arms. Initially established in the private sector, we recently received government approval to expand our programme into the provincial sector and have performed transplants on several provincial-sector patients. Current challenges relate to the lack of appropriately trained paediatric sub-specialists, specifically critical care practitioners and hepatologists.

METHODS

Subsequent to institutional approval, a retrospective chart analysis of all paediatric liver transplants performed at our facility to date was conducted.

RESULTS

Defining children as those under 18 years of age, 29 patients have received a cadaveric liver transplant since 2005, using 16 whole livers, 10 reduced-size grafts, and 3 split segments; 13 were transplanted with biliary atresia, 3 hyperoxalurea, 3 autosomal recessive polycystic disease, 2 alpha-1 antitrypsin deficiency, and 2 idiopathic, with the remainder for a wide spectrum of other pathologies. Seven patients received combined liver-kidney transplants. There were 3 in-hospital mortalities. The remaining 26 patients are all long-term survivors. We describe 7 acute surgical morbidities in 6 patients, and 8 long-term surgical morbidities. One patient was subsequently re-transplanted in Cape Town.

CONCLUSIONS

Despite a shortage of organs, we have overcome a steep learning curve, with results comparable with other early series. The current threat to the continued viability of our unit is the lack of appropriately trained paediatric hepatologists and intensivists.

Staphylococcus aureus infections after liver transplantation

BACKGROUND

More data on the risk factors and outcomes after Staphylococcus aureus infections in liver transplantation are needed.

METHODS

Liver recipients with S. aureus infections (cases) were retrospectively identified and compared to gender-, age-, and transplant type-matched (1:2) non-S. aureus-infected controls. Risk factors associated with S. aureus infections were identified by conditional logistic regression analysis.

RESULTS

We evaluated 51 patients (median age 52 years). First S. aureus infections developed at a median time of 29 days after transplantation, with 52.94% of them in the first month; 88.24% were nosocomial, 41.18% were polymicrobial, and 47.06% were caused by methicillin-resistant S. aureus (MRSA). Surgical site infections represented 58.82% and bacteremia 23.53%. By univariate analysis, patients with S. aureus infections were intubated more frequently (odds ratio [OR] 26.92, 95% confidence interval [CI] 3.23-3,504.15, p = 0.0006), had a central line (OR 11.69, 95% CI 1.42-95.9, p = 0.02), or recent surgery (OR 26.92, 95% CI 3.23-3,504.15, p = 0.0006) compared with controls. By multivariate analysis, subjects who underwent surgery within 2 weeks prior to infection had a 26.9 times higher risk of developing S. aureus infection (95% CI 3.23-3,504.15, p = 0.0006); these results were adjusted for matched criteria. S. aureus infections did not affect graft or patient survival, but the study was not powered for such outcomes.

CONCLUSION

Only recent surgical procedure was found to be a significant independent risk factor for S. aureus infections after liver transplantation.

Iron and the folate-vitamin B12-methylation pathway in multiple sclerosis

Some subjects with multiple sclerosis (MS) present with low blood iron parameters. Anecdotal reports and a single patient study suggest that iron supplementation may be beneficial in these subjects. Myelin is regenerated continually, but prerequisites for this process are iron and a functional folate-vitamin B12-methylation pathway. The aim of this study was to determine iron status, folate and homocysteine in MS subjects, and to evaluate the effect on MS symptoms if deficiencies were addressed.

RESULTS

In relapsing-remitting MS subjects, serum iron concentration correlated significantly with age at diagnosis (r=0.49; p=0.008). In Caucasian female MS subjects, serum iron and ferritin concentrations were significantly lower than in matched controls. In a 6-month pilot study, 12 subjects taking a regimen of nutritional supplements designed to promote myelin regeneration, improved significantly neurologically as measured by the Kurzke EDSS (Total Score means 3.50 to 2.45, 29.9%; p=0.021). These were significantly improved (p=0.002) compared to 6 control group patients taking multivitamins (Kurzke Score increased by 13.9% from 4.83 to 5.50). Both groups had significantly reduced homocysteine concentrations at 6 months, suggesting that methylation is necessary but not sufficient for myelin regeneration.

The effect of changing from pressure support ventilation to volume control ventilation on renal function

OBJECTIVE

Mechanical ventilation increases intrathoracic pressure and decreases cardiac output, and the associated hormonal changes may affect the free water, sodium and creatinine clearance. We sought to establish if there was any difference in creatinine clearance, urine volume and fractional excretion of sodium (FE(Na)) between pressure support ventilation (PSV) and volume controlled (VC) ventilation.

METHODS

The study took place in a 10 bedded metropolitan intensive care unit that admitted both medical and surgical patients. The study was a within subjects, non-randomised, controlled procedures design. Patients were included if they were ventilated on volume control ventilation (VC) with a constant positive end expiratory pressure (PEEP) and suitable for pressure support ventilation (PS), a mean arterial pressure of > 65 mmHg, a normal serum creatinine, well-hydrated and catheterised. Exclusion criteria were administration of a loop diuretic or renal dopamine in the six hours preceding the onset of the study, clinical adrenal dysfunction or clinically unstable requiring a change in intravenous fluid therapy. Eight patients completed four hours of VC ventilation and had renal functions monitored and then changed to PS ventilation for a one hour washout period. Four hours of PS were maintained and renal function monitored over a second four hour period. Patients remained on PS and then after a one hour washout on VC the final four hour monitored period on VC was completed. Urine and serum samples were collected for urine volume, fractional excretion of sodium and creatinine clearance during each four hour cycle on VC and PS ventilation.

RESULTS

Friedman's test statistical analysis revealed no significant difference in creatinine clearance (p = 0.54), fractional excretion of sodium (p = 0.58) or urine volume (p = 0.42).

CONCLUSIONS

VC ventilation had no adverse effects on renal indices in comparison to spontaneous PS ventilation.

The state of sedation in the nation: results of an Australian survey

OBJECTIVE

The authors conducted a postal survey to establish what the current sedative and analgesic practice in selected Australian intensive care units was.

METHODS

A questionnaire based on a European e-mail survey was devised and then posted to directors and senior Intensivists in 72 Australian intensive care units.

RESULTS

There were 47 returns out of 72 units. The most commonly used drugs were infusions of morphine and midazolam. A sedation scale was used in 21 of the units that replied to the survey. Only 7 units surveyed regularly audited complications related to sedation. The most common method of sedative/analgesic drug administration was by continuous infusion.

CONCLUSIONS

Despite recent recommendations for daily interruption of sedative agents and the use of a sedation scale, this was not the most common practice in Australian intensive care units. Most units used continuous infusions of midazolam and morphine for sedation/analgesia.

Harvesting impacts on commonly used medicinal tree species (Catha edulis and Rapanea melanophloeos) under different land management regimes in the Mpumalanga Lowveld, South Africa

Harvesting of products from plants in the wild is widespread throughout southern Africa. Particularly important products are plant parts used in traditional medicine. However, the impacts of harvesting practices are rarely quantified, with as yet insufficient generic rules across species and life forms. This limits the predictive ability to monitor and manage the affected populations. This paper examines the harvesting impact on two popular woody medicinal species used throughout sub-Saharan Africa, namely Catha edulis (Vahl) Forssk. ex Endl. (bushman’s tea) and Rapanea melanophloeos (L.) Mez. (Cape beech). In both species, basal diameters, heights, and the number of size classes in the harvested populations were lower than in unharvested. Densities of harvested populations were higher in both species, including densities of young plants, but the frequency of individuals in larger size classes was lower. The populations of both species being harvested for medicinal products appeared to be withstanding the current levels of harvesting, but the population structure of C. edulis populations being harvested for poles on the roadside and near human settlements had been substantially altered. Despite the resilience of the two species to harvesting for medicinal products, loss of habitat or changes in land use pose a threat to a number of the assessed populations.

An examination of triassic cynodont tooth enamel chemistry using fourier transform infrared spectroscopy

The Cynodontia are considered to be particularly significant as their remains document the reptile-to-mammal transition during the Permian and Triassic periods. Studies examining cynodont morphology and anatomy have shown that these animals acquired increasingly mammal-like characteristics during their evolution. In this study, we use Fourier Transform Infrared spectroscopy to assess the enamel structure of several Triassic cynodonts. Extant Crocodylus niloticus and Varanus enamel spectra as well as published extant and fossil mammalian data were used as comparisons. The profiles of the cynodont spectra resemble biological apatite, in spite of their great age. The ratio of structural carbonate to phosphate in these cynodonts is significantly higher than in the extant and fossil mammals, but very similar to the extant reptiles. We suggest that the enamel apatite structure of these cynodonts was more similar to the reptilian rather than the mammalian pattern.

A comparison of anthropogenic and elephant disturbance on Acacia xanthophloea (fever tree) populations in the Lowveld, South Africa

Acacia xanthophloea (the ‘fever tree’) is a popular medicinal species that is traded widely in South Africa. Although it occurs throughout southern Africa, there is increasing pressure on its riverine and marshy habitats. This study compares the impact of harvesting on an A. xanthophloea population located on private land near Komatipoort, Mpumalanga, with two protected populations situated within the Kruger National Park. The densities of the harvested and protected populations were similar (84±8 trees/ha and 85±20 trees/ha, respectively). There were fluctuations in the quotients between frequencies of trees in successive diameter classes, which is common in savanna where high levels of fire, mega-herbivore and anthropogenic disturbance are experienced. The extent of stem damage (stripping of bark and breakage) by elephants in the protected area was significantly higher than the extent of harvesting on private land, although the degree of damage was relatively low, with only 7 % of the populations having been damaged at rates >26 %. The degree of harvesting on private land was relatively low, with the majority of trees having been harvested at rates of less than 10 % of the stem below 2 m. Despite this, ringbarking had occurred (4 %). The basal diameters and heights were significantly lower in the protected population than in the harvested one, suggesting that over time elephant impact was the more severe disturbance. Acacia xanthophloea exhibited high resilience to disturbance, with all the elephant damaged trees and harvested individuals surviving. However, the mean bark thickness measured in local markets (6.3±1.4 mm) was significantly lower than that measured in either the harvested (12.4±1.0 mm) or the KNP (10.3±0.8 mm) populations. As harvesters tend to select the largest individuals in a population to maximise their financial returns, this could mean that smaller individuals are being harvested, and/or bark is not being given sufficient time to grow back after harvesting. Acacia xanthophloea outside protected areas thus need to be monitored and the management improved, preferably in conjunction with the resource users. In addition, traditional healers, those selling medicinal plants and other members of the community need to continue to be encouraged to cultivate this fast growing species.

An inventory of medicinal plants traded on the western boundary of the Kruger National Park, South Africa

The World Health Organisation estimates that traditional medicine still plays a vital role in the lives of 70-80 of the populations of developing countries. Approximately 20 000 tons of medicinal plants are estimated to be traded in South Africa annually, resulting in considerable pressure on the wild populations from which these plants are harvested. In 1997, a study was initiated to assess the extent of trade in medicinal plants on the western boundary of the Kruger National Park, and to determine local perceptions of the availability and values of these plants. This paper presents an inventory of the species traded, including vendors' and traders' perceptions of current availability of species and consumer demand, as well as price/kg. In Mpumalanga, 176 species were identified (71 of the vernacular names encountered in the market place), representing 69 families. In Northern Province, 70 different species were identified (84 of the ver-nacular names recorded in the markets), representing 40 families. Perceptions of availability of a species varied considerably, often within the same markets. Perceptions of demand tended to be more consistent, although these also sometimes varied. Although monitoring markets is an efficient means of assessing the conservation status of medicinal plants, it is important to select appropriate parameters. Markets often differ from one another, and an understanding of local conditions is crucial. For example, in the medicinal markets on the western boundary of the Kruger National Park, price/kg and market perceptions of availability of species were highly variable and would thus not provide a consistent monitoring parameter. Perceptions of demand provide an indication of current and potential pressure on a species, particularly when combined with the monitoring of species traded, and the introduction of substitutes in the market place. The size of plant parts traded could also provide useful monitoring data. It is important to identify the plants utilised locally first hand where possible, due to the variation of vernacular names from one area to another.