Hypertension, end-stage renal disease and mesangiocapillary glomerulonephritis in methamphetamine users

Background: Methamphetamine abuse has risen dramatically in South Africa. The chronic effects of abuse on the kidneys and blood pressure have not been documented. This study reviewed patients referred for evaluation of kidney disease and/or hypertension, who had been abusing methamphetamines.Methods: The records of patients referred to the renal unit between 2005 and 2013 who had been using methamphetamines were retrospectively reviewed. Patient demographics, biophysical parameters, blood pressure, renal function, renal ultrasound and biopsy findings, complications of chronic kidney disease and comorbidities were recorded.Results: Forty-seven patients were included in the study. Their mean age was 29 years. Hypertension was present in 42 (89.4%) of patients, with malignant hypertension in 21 (44.7%). Forty-five (95.7%) had chronic kidney disease (CKD), and 26 (55.3%) had end-stage renal disease. Renal biopsies were performed in 24 patients. Twelve (50.0%) of the biopsies showed hypertensive changes and 14 (58.3%) mesangiocapillary glomerulonephritis type 1, with deposition of IgM and C3 complement.Conclusion: Methamphetamine use is associated with severe hypertension, mesangiocapillary glomerulonephritis and CKD

Evaluation and management of patients referred to a tertiary-level hypertension clinic in Cape Town, South Africa

Background. Hypertension remains a global health burden, with a high incidence of long-term morbidity and mortality.Objectives. To evaluate blood pressure (BP) control, factors associated with poor BP control, target organ damage (TOD), white-coat hypertension, treatment-resistant hypertension and secondary hypertension in patients referred to a tertiary-level hypertension clinic.Method. This was a prospective case-control study of patients referred for specialist hypertension management. Patient parameters recorded included age, gender, body mass index, uric acid, cholesterol, screening BP  follow-up BP, TOD and  medications. We also recorded causes of secondary hypertension. Net BP change and the percentage achieving target BP were calculated in all patients followed up.Results. A total of 175 patients were sampled (72 males and 103 females, mean age 46.5 years). Of the patients 16.6% had a normal screening BP; 62.9% of  patients were followed up, and 43.6% of these achieved BP control. After  intervention, there was a net drop of 13.2 mmHg (range 7.9 - 18.4) in systolic BP and of 3.8 mmHg (4.4 - 12.0) in diastolic BP. Of all the patients, 12.6% had resistant hypertension, 49.1% had evidence of left ventricular hypertrophy and 18.3% had microalbuminuria; 13.1% of the patients were diagnosed with secondary hypertension.Conclusion. Specialist intervention was useful in identifying patients with white-coat and secondary hypertension, as well as in improving hypertension control in patients with apparent treatment-resistant hypertension. However, a significant percentage of patients did not reach target BP, and further efforts are required to identify the underlying causes for this

A modern look at hypertension and anaesthesia

Hypertension is common among patients presenting for surgery, and is frequently untreated or inadequately treated. While the approach to the patient with hypertension presenting for anaesthesia is controversial, and the evidence base for appropriate clinical decisions is weak, this is a problem that practising clinical anaesthetists face on a regular basis. This article seeks to present a unified approach to the problem of a  hypertensive patient presenting for surgery, and offers suggestions as to the appropriate management options. As far as possible, the recommendations contained in this article have been based on the best available evidence. The authors suggest that moderate degrees of hypertension (up to 180/120 mmHg), without obvious target organ disease, should never be grounds for postponing surgery. Even with greater degrees of hypertension, the relative risk of postponing surgery should always be considered. There is little evidence that, in patients without target organ disease, delaying surgery in order to establish  antihypertensive therapy is beneficial. For very severe hypertension, the benefits of delaying surgery to establish adequate hypertensive control must be weighed against the risk of delayed surgery. Where a surgical delay is considered, adequate time to establish appropriate blood pressurecontrol must be allowed, and there is no place for sudden “cosmetic” correction of blood pressure immediately prior to anaesthesia. Previously undiagnosed hypertension, presenting for the first time at surgery, requires a basic investigation of target organ disease prior to anaesthesia, and appropriate subsequent follow-up referral for further management

A modern look at hypertension and anaesthesia

Hypertension is common among patients presenting for surgery, and is frequently untreated or inadequately treated. While the approach to the patient with hypertension presenting for anaesthesia is controversial, and the evidence base for appropriate clinical decisions is weak, this is a problem that practising clinical anaesthetists face on a regular basis. This article seeks to present a unified approach to the problem of a hypertensive patient presenting for surgery, and offers suggestions as to the appropriate management options. As far as possible, the recommendations contained in this article have been based on the best available evidence. The authors suggest that moderate degrees of hypertension (up to 180/120 mmHg), without obvious target organ disease, should never be grounds for postponing surgery. Even with greater degrees of hypertension, the relative risk of postponing surgery should always be considered. There is little evidence that, in patients without target organ disease, delaying surgery in order to establish antihypertensive therapy is beneficial. For very severe hypertension, the benefits of delaying surgery to establish adequate hypertensive control must be weighed against the risk of delayed surgery. Where a surgical delay is considered, adequate time to establish appropriate blood pressure control must be allowed, and there is no place for sudden “cosmetic” correction of blood pressure immediately prior to anaesthesia. Previously undiagnosed hypertension, presenting for the first time at surgery, requires a basic investigation of target organ disease prior to anaesthesia, and appropriate subsequent follow-up referral for further management.Keywords: hypertension, anaesthesia, ris

Therapeutic drug monitoring of amlodipine and the Z-FHL/HHL ratio: Adherence tools in patients referred for apparent treatment-resistant hypertension

Background. Non-adherence to antihypertensives is a cause of ‘pseudo-treatment-resistant’ hypertension. Objective. To determine whether monitoring plasma amlodipine concentrations and inhibition of angiotensin-converting enzyme (ACE) can be adjunct adherence tools. Methods. Patients with hypertension who were prescribed enalapril and amlodipine were enrolled. Blood pressures (BPs) were monitored and an adherence questionnaire was completed. Steady-state amlodipine was assayed using liquid chromatography-mass spectrometry and degree of ACE inhibition using the Z-FHL/HHL (z-phenylalanine-histidine-leucine/hippuryl-histidine-leucine) ratio. Results. One hundred patients (mean (standard deviation) age 50.5 (12) years, 46% male) were enrolled. Based on plasma assays, 26/97 patients (26.8%) were unsuppressed by enalapril and 20/100 (20%) were sub-therapeutic for amlodipine. There were significant BP differences based on plasma levels of the medication: 21/20 mmHg lower in the group with suppressed ACE and 26/20 mmHg in the group with steady-state amlodipine concentrations. Conclusions. Monitoring antihypertensive adherence by assaying plasma medication concentrations is a feasible option for evaluating true v. pseudo-resistant hypertension.S Afr Med J 2017;107(10):887-89

Sterile Protection against Plasmodium knowlesi in Rhesus Monkeys from a Malaria Vaccine: Comparison of Heterologous Prime Boost Strategies

Using newer vaccine platforms which have been effective against malaria in rodent models, we tested five immunization regimens against Plasmodium knowlesi in rhesus monkeys. All vaccines included the same four P. knowlesi antigens: the pre-erythrocytic antigens CSP, SSP2, and erythrocytic antigens AMA1, MSP1. We used four vaccine platforms for prime or boost vaccinations: plasmids (DNA), alphavirus replicons (VRP), attenuated adenovirus serotype 5 (Ad), or attenuated poxvirus (Pox). These four platforms combined to produce five different prime/boost vaccine regimens: Pox alone, VRP/Pox, VRP/Ad, Ad/Pox, and DNA/Pox. Five rhesus monkeys were immunized with each regimen, and five Control monkeys received a mock vaccination. The time to complete vaccinations was 420 days. All monkeys were challenged twice with 100 P. knowlesi sporozoites given IV. The first challenge was given 12 days after the last vaccination, and the monkeys receiving the DNA/Pox vaccine were the best protected, with 3/5 monkeys sterilely protected and 1/5 monkeys that self-cured its parasitemia. There was no protection in monkeys that received Pox malaria vaccine alone without previous priming. The second sporozoite challenge was given 4 months after the first. All 4 monkeys that were protected in the first challenge developed malaria in the second challenge. DNA, VRP and Ad5 vaccines all primed monkeys for strong immune responses after the Pox boost. We discuss the high level but short duration of protection in this experiment and the possible benefits of the long interval between prime and boost

Plasmodium falciparum Merozoite Invasion Is Inhibited by Antibodies that Target the PfRh2a and b Binding Domains

Plasmodium falciparum, the causative agent of the most severe form of malaria in humans invades erythrocytes using multiple ligand-receptor interactions. The P. falciparum reticulocyte binding-like homologue proteins (PfRh or PfRBL) are important for entry of the invasive merozoite form of the parasite into red blood cells. We have analysed two members of this protein family, PfRh2a and PfRh2b, and show they undergo a complex series of proteolytic cleavage events before and during merozoite invasion. We show that PfRh2a undergoes a cleavage event in the transmembrane region during invasion consistent with activity of the membrane associated PfROM4 protease that would result in release of the ectodomain into the supernatant. We also show that PfRh2a and PfRh2b bind to red blood cells and have defined the erythrocyte-binding domain to a 15 kDa region at the N-terminus of each protein. Antibodies to this receptor-binding region block merozoite invasion demonstrating the important function of this domain. This region of PfRh2a and PfRh2b has potential in a combination vaccine with other erythrocyte binding ligands for induction of antibodies that would block a broad range of invasion pathways for P. falciparum into human erythrocytes

Common variants of the beta and gamma subunits of the epithelial sodium channel and their relation to plasma renin and aldosterone levels in essential hypertension

BACKGROUND: Rare mutations of the epithelial sodium channel (ENaC) result in the monogenic hypertension form of Liddle's syndrome. We decided to screen for common variants in the ENaC βand γ subunits in patients with essential hypertension and to relate their occurrence to the activity of circulating renin-angiotensin-aldosterone system. METHODS: Initially, DNA samples from 27 patients with low renin/low aldosterone hypertension were examined. The DNA variants were subsequently screened for in 347 patients with treatment-resistant hypertension, 175 male subjects with documented long-lasting normotension and 301 healthy Plasma renin and aldosterone levels were measured under baseline conditions and during postural and captopril challenge tests. RESULTS: Two commonly occurring βENaC variants (G589S and a novel intronic i12-17CT substitution) and one novel γENaC variant (V546I) were detected. One of these variants occurred in a heterozygous form in 32 patients, a prevalence (9.2%) significantly higher than that in normotensive males (2.9%, p = 0.007) and blood donors (3.0%, p = 0.001). βENaC i12-17CT was significantly more prevalent in the hypertension group than in the two control groups combined (4.6% vs. 1.1%, p = 0.001). When expressed in Xenopus oocytes, neither of the two ENaC amino acid-changing variants showed a significant difference in activity compared with ENaC wild-type. No direct evidence for a mRNA splicing defect could be obtained for the βENaC intronic variant. The ratio of daily urinary potassium excretion to upright and mean (of supine and upright values) plasma renin activity was higher in variant allele carriers than in non-carriers (p = 0.034 and p = 0.048). CONCLUSIONS: At least 9% of Finnish patients with hypertension admitted to a specialized center carry genetic variants of β and γENaC, a three times higher prevalence than in the normotensive individuals or in random healthy controls. Patients with the variant alleles showed an increased urinary potassium excretion rate in relation to their renin levels

Merozoite release from Plasmodium falciparum-infected erythrocytes involves the transfer of DiIC16 from infected cell membrane to Maurer’s clefts

Merozoite release from infected erythrocytes is a complex process, which is still not fully understood. Such process was characterised at ultra-structural level in this work by labelling erythrocyte membrane with a fluorescent lipid probe and subsequent photo-conversion into an electron-dense precipitate. A lipophilic DiIC16 probe was inserted into the infected erythrocyte surface and the transport of this phospholipid analogue through the erythrocyte membrane was followed up during 48 h of the asexual erythrocyte cycle. The lipid probe was transferred from infected erythrocyte membranes to Maurer’s clefts during merozoite release, thereby indicating that these membranes remained inside host cells after parasite release. Fluorescent structures were never observed inside infected erythrocytes preceding merozoite exit and merozoites released from infected erythrocyte were not fluorescent. However, specific precipitated material was localised bordering the parasitophorous vacuole membrane and tubovesicular membranes when labelled non-infected erythrocytes were invaded by merozoites. It was revealed that lipids were interchangeable from one membrane to another, passing from infected erythrocyte membrane to Maurer’s clefts inside the erythrocyte ghost, even after merozoite release. Maurer’s clefts became photo-converted following merozoite release, suggesting that these structures were in close contact with infected erythrocyte membrane during merozoite exit and possibly played some role in malarial parasite exit from the host cell