Interest In Clinical Medicine Research Articles

The role of biomarkers in early identification of acute kidney injury among non-critically ill patients.

Prediction and/or early identification of acute kidney injury (AKI) and individuals at greater risk remains of great interest in clinical medicine. Acute kidney injury continues to be a common complication among hospitalized patients, with an incidence ranging from 6 to 58%, depending on the setting.Aim of this study was to determine the performance of Insulin-like growth factor binding protein-7 (IGFBP7), tissue metallopeptidase inhibitor 2 (TIMP2), and urinary neutrophil gelatinase-associated lipocalin (uNGAL) in early detection of AKI among non-critically ill patients. In this prospective observational study at Mayo Clinic Hospitals in Rochester, Minnesota, USA, non-critically ill patients admitted from the emergency department between October 31st, 2016 and May 1st, 2018, who had an acute kidney injury (AKI) probability of 5% or higher were included. Biomarkers were measured in residual urine samples collected in the emergency department. The primary outcome was biomarker performance in predicting AKI development within the first 72h. Among 368 included patients, the mean age was 79 ± 12years, and 160 (43%) were male. Acute kidney injury occurred in 62 (17%) patients; 11.5% stage 1, 2.5% stage 2, and 3% stage 3. Twelve patients (3%) died during hospitalization and 102 (28%) within nine months after admission. The median uNGAL and IGFBP7-TIMP2 were 57 [20-236ng/ml], and 0.3 [0.1-0.8], respectively. The C-statistic of uNGAL and IGFBP7-TIMP2 of > 0.3 and > 2.0 for AKI prediction were 0.56, 0.54, and 0.53, respectively. In a model where one point is assigned to each marker of AKI (elevated serum creatinine, IGFBP7-TIMP2 > 0.3, and uNGAL), a higher score correlated with higher nine-month mortality [OR of 1.32 per point (95% CI 1.02-1.71)]. Among non-critically ill hospitalized patients, the performance of uNGAL and IGFBP7-TIMP2 for AKI prediction within 72h of admission was modest. This suggests a limited role for these biomarkers in AKI risk stratification among non-critically ill patients. Key learning points What was known Acute kidney injury (AKI) is a common complication among hospitalized patients. It is associated with increased morbidity and mortality. Various clinical prediction models and biomarkers have been developed to identify patients in special populations (such as ICU and cardiac surgery) who are at risk of AKI and diagnose AKI early. This study adds The performance of the biomarkers uNGAL, TIMP-2, and IGFBP-7 in predicting AKI within 72h of admission in non-critically ill patients was modest. However, these biomarkers were found to have a prognostic value for predicting 9-month mortality. One potential application of these biomarkers is identifying patients at higher AKI risk before exposing them to nephrotoxic agents. Potential impact This study provides evidence regarding the real-world performance of current FDA-approved biomarkers (uNGAL, TIMP-2, and IGFBP-7) for predicting acute kidney injury (AKI) within 72h of hospital admission among noncritically ill patients. While the performance of these biomarkers for predicting short-term AKI was modest, they may have a prognostic value for predicting 9-month mortality.

Systematic review/meta-analysis and a cross-sectional study to assess effects of potassium supplementation on the renin-angiotensin-aldosterone system (RAAS) and blood pressure

Abstract Introduction Nutritional medicine plays a key role in disease prevention and treatment, and we pharmacists must consider our contribution beyond our role in dispensing. Apart from the Dietary Approaches to Stop Hypertension (DASH) diet1, there is a paucity of data on the benefits of nutritional interventions in hypertension with no clear recommendation on potassium in the NICE guidelines. Potassium has been an area of interest in clinical medicine over the decades because of its effect on cardiovascular disease. However, its mechanism of action is poorly understood, and it is unclear it differs between different ethnic groups. Dietary potassium decreases blood pressure (BP) but can also stimulate aldosterone production2. However, the magnitude of potassium-dependent regulation of aldosterone secretion in humans is not fully characterised and it is not clear whether this is mediated by activation of the renin-angiotensin-aldosterone system (RAAS) as a result of a reduction in BP or other mechanisms. Aim To perform a (1) systematic review and meta-analysis of clinical trials assessing effects of potassium on plasma aldosterone and renin in adult individuals alongside a (2) cross-sectional multi-ethnic study to explore the relationship between potassium intake and aldosterone in hypertension. Methods (1) This study was carried out in accordance with PRISMA guidelines3. The full protocol can be found on the PROSPERO database. (2) Self-defined black or white hypertensives were recruited from the hypertension outpatient clinic at St. Thomas’ Hospital and had aldosterone, renin and a 24-hour urinary potassium collected. The systematic review and meta-analysis on already approved clinical trials and did not require ethnical approval. The cross-sectional study was approved by the local Research Ethics Committee in the UK and written informed consent was obtained from all patients. Results 6395 articles were retrieved, and 124 full-text articles were assessed for eligibility. 36 met the prespecified inclusion/exclusion criteria. Potassium supplementation caused a significant decrease in systolic BP (- 3.69 mmHg [-4.91, -2.46], P<0.001) and increase in serum potassium (+0.37 [0.23, 0.52] mmol/L, P<0.001). There was an increase in plasma aldosterone (standardised difference 0.414 [0.291, 0.537], P<0.001) but no effect on plasma renin activity (+0.033 [-0.07, 0.14], P=0.538]. Meta-regression showed a significant positive correlation between change in plasma aldosterone and change in serum potassium (P<0.001). (2) In 469 subjects (72% black), there was a positive association between the measured 24-hour potassium excretion and aldosterone in black (β = 0.200, P = 0.014) but not in white individuals (P = 0.531). Discussion/Conclusion Potassium supplementation increases plasma aldosterone but not renin. The increase in aldosterone correlates with the raise in serum potassium. In subjects with hypertension, potassium intake is related with aldosterone concentration only in black subjects. Overall, the data supports a RAAS-independent potassium regulation of aldosterone which could be particularly relevant in African origin subjects. Limitations: 1. the systematic review results could not be stratified by ethnicity because most of the studies were performed in Caucasian subjects, 2. Use of background therapy in some studies, variable doses of potassium supplementation and duration of supplementation.

Opportunities to increase the attractiveness of the German Public Health Service as an employer

Abstract For decades, the public health service in Germany (PHS) experienced shortages of young professionals and challenges in recruiting qualified personnel. To sustainably counteract this challenge, it is necessary to understand the reasons of the perceived low attractiveness of PHS as a potential employer among students and young professionals. Two cross-sectional online surveys were conducted to assess the attitudes of medical, public health, and health science students towards the PHS as a potential employer. Wave 1, conducted from 2019-12 to 2020-04, focused on factors associated with high and with low interest in working for the PHS. Wave 2 was conducted from 2020-06 to 2020-09 to capture changes that may have resulted from the newfound attention of the PHS during the SARS-CoV-2 pandemic. Participants in both waves were asked about opportunities to increase the attractiveness of the PHS, which were analyzed using qualitative content analysis. In total 3040 students participated. Low interest in the PHS was associated with limited knowledge about public health, primary interest in clinical medicine, and a negative image of the public service. The qualitative analysis indicated as major obstacles: low visibility of and low awareness about the PHS, a perception of hierarchical and bureaucratic workplaces, and perceptions of repetitive occupations, among others. The participants suggested: improving awareness about the PHS in the population, including PHS in curriculum, and reducing entry barriers for non-medical students. The results of the largest survey of students on the attractiveness of the ÖGD in Germany provide valuable insights for ongoing reform processes. In addition to approaches to increase external visibility, existing processes and procedures within the ÖGD should be considered. Key messages • To counteract the shortage of skilled workers, the PHS must become more attractive to young professionals. This requires both, greater external visibility and modernization of internal structures. • Successful inclusion of the perspective of young professionals in the current modernization processes introduces opportunities to increase the attractiveness of the PHS in the long-term.

An introduction to machine learning for clinicians: How can machine learning augment knowledge in geriatric oncology?

Interest in machine learning (ML) approaches to analyze patient data is in an explosive phase of growth. Underpinning this burgeoning interest are several advances in technology, including availability of computing power, evolution of ML software, and the ubiquity of electronic health records (EHRs). Personal computers now have sufficient computational power to run some ML algorithms for small to medium datasets, encompassing many of the datasets of interest in clinical medicine. Even for very large datasets (“big data”, with number of data points in the billions, trillions, or more), access to parallel computing resources is now widespread at academic medical centers and via cloud computing platforms.

Evaluation of susceptibility and response in the surface of agents of surface mycoses (Trichophyton mentagrophytes; T. tonsurans) to antifungal drugs of interest in a medical clinic

Introduction: The resistance of fungal species to drugs usually used in clinics is of great interest in the medical field. Objective: To evaluate susceptibility and in vitro response of species of Trichophyton spp. to antifungal drugs of interest in clinical medicine. Methods: 12 samples of clinical isolates from humans were used, nine of T. mentagrophytes and three of T. tonsurans. Susceptibility tests were performed according to the agar diffusion (AD) and broth microdilution (BM) methods. Results: In the AD method, the species T. tonsurans presented a percentage of sensitivity of 33% in relation to amphotericin B and 66% to itraconazole, with 100% resistance to ketoconazole and fluconazole. T. mentagrophytes also showed 100% resistance to ketoconazole in this technique, with 11% sensitivity to ketoconazole, 22% to itraconazole and 22% of samples classified as sensitive dose dependent. In the MC method, the species T. tonsurans presented a sensitivity percentage of 66%, 55% and 33% in relation to ketoconazole, fluconazole and itraconazole, respectively. The T. mentagrophytes species presented sensitivity percentages of 11%, 11%, 33% and 55% for amphotericin B, itraconazole, ketoconazole and fluconazole, respectively. Conclusion: There was resistance in vitro of the species of T. mentagrophytes and T. tonsurans against the antifungal fluconazole and relative resistance against ketoconazole in the AD method. In BM, however, important percentages of sensitivity were observed for the two species analyzed in relation to the antifungals fluconazole and ketoconazole when compared to itraconazole and amphotericin B.

A novel structure for online surgical undergraduate teaching during the COVID-19 pandemic

BackgroundThe Covid-19 pandemic necessitated the delivery of online higher education. Online learning is a novel experience for medical education in Sri Lanka. A novel approach to undergraduate surgical learning was taken up in an attempt to improve the interest amongst the students in clinical practice while maximizing the limited contact time.MethodOnline learning activity was designed involving medical students from all stages and multi consultant panel discussions. The discussions were designed to cover each topic from basic sciences to high-level clinical management in an attempt to stimulate the student interest in clinical medicine. Online meeting platform with free to use basic plan and a social media platform were used in combination to communicate with the students. The student feedback was periodically assessed for individual topics as well as for general outcome. Lickert scales and numeric scales were used to acquire student agreement on the desired learning outcomes.ResultsA total of 1047 student responses for 7 questionnaires were analysed. During a 6-week period, 24 surgical topics were discussed with 51 contact hours. Eighty-seven per cent definitely agreed (highest agreement) with the statement ‘students benefitted from the discussions’. Over 95% have either participated for all or most sessions. A majority of the respondents (83.4%) ‘definitely agreed’ that the discussions helped to improve their clinical sense. Of the total respondents, 79.3% definitely agreed that the discussions helped to build an interest in clinical medicine. Around 90% agreed that both exam-oriented and clinical practice-oriented topics were highly important and relevant. Most widely raised concerns were the poor Internet connectivity and limitation of access to the meeting platform.ConclusionOnline teaching with a novel structure is feasible and effective in a resource-limited setting. Students agree that it could improve clinical interest while meeting the expected learning outcomes.

Biomedical applications of copper-impregnated bioactive glass

Bioactive glass (BG) is generally reckoned as an active constituent that both bonds with skeleton and connects with cartilage. This active material often releases the active ions in a controlled fashion via degradation, which is of particular interest in clinical medicine. However, monodispersed bioactive glass without modification still exists limitations, e.g., aggregation or lower activities both in vitro and in vivo . Owing to its unique morphology, distinctive cell uptake process, excellent degradation and biomineralization ability, as well as certain high biosafety, functionalized bioactive glass plays a key role in diverse biomedical applications such as bioimaging, gene/drug delivery and wound healing, facilitating the self-repair and regeneration of tissues. The interesting physicochemical properties of bioactive glass can be adjusted by appropriately selecting active ions, especially metal ions, as impregnated components to alter original bridging oxygen (BO) network to non-bridging oxygen (NBO) structure. In terms of the difference in matrix, bioactive glass is generally devided into three types, i.e., silicate, borate, and phosphate-based architectures. As a universal element in human physiological fluids, copper ions can also be impregnated in the structure of bioactive glass, in which these species not only affect the signal pathway and metabolic activity, but also serve as essential cofactors for many enzymes. After the ion exchange with the surrounding fluidic environment, copper ions can be precisely released at the desired site, minimizing the adverse effects. On the one hand, the impregnated copper ions inhibit the activity of osteoclast and stimulate the generation and aggregation of collagens, which significantly impact on the formation and healing of skeleton and cartilage. On the other hand, these copper species not only upregulate the expresssion of fibroblast growth factor (FGF)-2 and hypoxia inducible factor (HIF)-1α, but also enhance the production of endothelial nitric oxide synthase, subsequently promoting the proliferation and migration of human endothelial cells. In addition, the doped copper species are capable of bonding with mercapto, imidazole, carboxyl and amine, among others, to make changes in the membrane structure, including permeability augmentation and membrane transport dysfunction, indicating efficient antibacterial ability. Besides, hyperthermia process appears due to the photothermal effect after the irridation of near-infrared. In another case, copper ions participate in Fenton-like reaction under the acidic microenvironment of tumors, converting glutathione to oxidized glutathione, catalyzing the generation of reactive oxygen species (ROS), thus leading to the damage of mitochondria, ultimately inducing the apoptosis of cancer cells. Currently, it is required to achieve clinical translation from laboratory outcomes. Despite of a series of advantegeous features, the biomedical applications of copper-impregnated bioactive glass are still facing great challenges. To further facilitate the superiority of this prospective field, the developmental proposals are systemically discussed in this review. Further, critical discussions on effectively solving the aggregation caused by high-temperature sintering process and the denaturation induced by organic solvent utilization are emphasized. Moreover, the encapsulation mechanisms of certain molecules and compensate for the dificient exertion in cancer therapeutics are elaborated, providing an innovative and uninvasive platform in the field of prosperous biomedicine.

“From womb to tomb; we’re bound to others”: microbiome in forensic science

Microbiome is a new field of interest in clinical medicine with high potential in forensic medicine. It could be used in several applications, such as post-mortem interval (PMI) estimation, personal identification, differential diagnosis of cause of death and toxicology. Regarding PMI, during the decomposition of a corpse, the passage of time involves changing in microbial population both outside and inside the corpse but also in surrounding soil (cadaver decomposition island). These variations could be hypothetically used as PMI indicators (microbial clock), even thanks to the development of machine learning approach. Another potential use of skin and saliva microbiome is personal identification thanks to its inter-individual variability and tendency to remain unvarying over time. It may also be helpful to link a person to a specific object that has been touched (microbial fingerprint). Furthermore, we could infer some information about health state of human subjects, comparing post-mortem and ante-mortem microbiome, but this field of research is quite new and needs further studies. Moreover, we have to consider the influence of microbiome metabolism in post-mortem toxicological evaluation; microbes could alter substances concentrations – for example of ethanol, gamma-hydroxybutyric acid (GHB) and nitrobenzodiazepines – due to enzymatic degradation and individual microbial metabolism. Finally, integration of microbiome and human being’s transcriptomic analysis may be helpful to depict their complex interactions even after death.

Stephen G. Young

Stephen G. Young

Expression profiling-based clustering of healthy subjects recapitulates classifications defined by clinical observation in Chinese medicine

Differences between healthy subjects and associated disease risks are of substantial interest in clinical medicine. Based on clinical presentations, Traditional Chinese Medicine (TCM) classifies healthy people into nine constitutions: Balanced, Qi, Yang or Yin deficiency, Phlegm-dampness, Damp-heat, Blood stasis, Qi stagnation, and Inherited special constitutions. In particular, Yang and Yin deficiency constitutions exhibit cold and heat aversion, respectively. However, the intrinsic molecular characteristics of unbalanced phenotypes remain unclear. To determine whether gene expression-based clustering can recapitulate TCM-based classification, peripheral blood mononuclear cells (PBMCs) were collected from Chinese Han individuals with Yang/Yin deficiency (n = 12 each) and Balanced (n = 8) constitutions, and global gene expression profiles were determined using the Affymetrix HG-U133A Plus 2.0 array. Notably, we found that gene expression-based classifications reflected distinct TCM-based subtypes. Consistent with the clinical observation that subjects with Yang deficiency tend toward obesity, series-clustering analysis detected several key lipid metabolic genes (diacylglycerol acyltransferase (DGAT2), acyl-CoA synthetase (ACSL1), and ATP-binding cassette subfamily A member 1 (ABCA1)) to be down- and up-regulated in Yin and Yang deficiency constitutions, respectively. Our findings suggest that Yin/Yang deficiency and Balanced constitutions are unique entities in their mRNA expression profiles. Moreover, the distinct physical and clinical characteristics of each unbalanced constitution can be explained, in part, by specific gene expression signatures.

Expression Profiling of Transcriptome and Its Associated Disease Risk in Yang Deficiency Constitution of Healthy Subjects

Objectives. Differences among healthy subjects and associated disease risks are of substantial interest in clinical medicine. According to the theory of “constitution-disease correlation” in traditional Chinese medicine, we try to find out if there is any connection between intolerance of cold in Yang deficiency constitution and molecular evidence and if there is any gene expression basis in specific disorders. Methods. Peripheral blood mononuclear cells were collected from Chinese Han individuals with Yang deficiency constitution (n = 20) and balanced constitution (n = 8) (aged 18–28) and global gene expression profiles were determined between them using the Affymetrix HG-U133 Plus 2.0 array. Results. The results showed that when the fold change was ≥1.2 and q ≤ 0.05, 909 genes were upregulated in the Yang deficiency constitution, while 1189 genes were downregulated. According to our research differential genes found in Yang deficiency constitution were usually related to lower immunity, metabolic disorders, and cancer tendency. Conclusion. Gene expression disturbance exists in Yang deficiency constitution, which corresponds to the concept of constitution and gene classification. It also suggests people with Yang deficiency constitution are susceptible to autoimmune diseases, enteritis, arthritis, metabolism disorders, and cancer, which provides molecular evidence for the theory of “constitution-disease correlation.”

Genotyping of the Duffy blood group among Plasmodium knowlesi-infected patients in Malaysia.

The Duffy blood group is of major interest in clinical medicine as it plays an important role in Plasmodium knowlesi and Plasmodium vivax infection. In the present study, the distribution of Duffy blood group genotypes and allelic frequencies among P. knowlesi infected patients as well as healthy individuals in Peninsular Malaysia were determined. The blood group of 60 healthy blood donors and 51 P. knowlesi malaria patients were genotyped using allele specific polymerase chain reaction (ASP-PCR). The data was analyzed using Fisher's exact test in order to assess the significance of the variables. Our results show a high proportion of the FY*A/FY*A genotype (>85% for both groups) and a high frequency of the FY*A allele (>90% for both groups). The FY*A/FY*A genotype was the most predominant genotype in both infected and healthy blood samples. The genotype frequency did not differ significantly between the donor blood and the malaria patient groups. Also, there was no significant correlation between susceptibility to P. knowlesi infection with any Duffy blood genotype.

Anti-Yersinia Activity of Cryptdin-2: A Paneth Cell Peptide

In view of the emerging antibiotic(s) resistance in pathogens, there is a renewed interest in clinical medicine to exploit novel agents with a wide range of actions over several pathogens. Therefore, in the present study, bactericidal efficacy of cryptdin-2 against Yersinia enterocolitica was evaluated. Cryptdin-2 exhibited strong bactericidal activity against Y. enterocolitica at the minimum bactericidal concentration (MBC) of 21 μg/ml. Scanning electron microscopic investigations of cryptdin-2 treated bacterial cells revealed that the peptide was able to induce significant morphological alterations in terms of destructive pore formation and damaged membrane confirming its membrane dependent bactericidal activity. N-phenyl napthylamine (NPN) uptake assay in the presence of sublethal, lethal as well as twice the lethal concentrations further confirmed the membrane-dependent mode of action of cryptdin-2 which indicated that the peptide could permeabilize the membrane of Y. enterocolitica. Additionally, the peptide interfered with DNA, RNA as well as protein synthesis in Y. enterocolitica, with maximum inhibition observed for protein synthesis. Thus, the biochemical and biophysical alterations observed in the treated cells in terms of macromolecular synthesis and membrane permeabilization respectively, correlated well with the bactericidal activity. In view of the antibacterial efficacy of the peptide against Salmonella typhimurium and Entamoeba histolytica, observed in our earlier studies, along with its inhibitory potential against Y. enterocolitica as demonstrated in the present study, suggests that it may be exploited as a broad-spectrum antimicrobial agent against enteric infections.

Fiber Types in Mammalian Skeletal Muscles

Mammalian skeletal muscle comprises different fiber types, whose identity is first established during embryonic development by intrinsic myogenic control mechanisms and is later modulated by neural and hormonal factors. The relative proportion of the different fiber types varies strikingly between species, and in humans shows significant variability between individuals. Myosin heavy chain isoforms, whose complete inventory and expression pattern are now available, provide a useful marker for fiber types, both for the four major forms present in trunk and limb muscles and the minor forms present in head and neck muscles. However, muscle fiber diversity involves all functional muscle cell compartments, including membrane excitation, excitation-contraction coupling, contractile machinery, cytoskeleton scaffold, and energy supply systems. Variations within each compartment are limited by the need of matching fiber type properties between different compartments. Nerve activity is a major control mechanism of the fiber type profile, and multiple signaling pathways are implicated in activity-dependent changes of muscle fibers. The characterization of these pathways is raising increasing interest in clinical medicine, given the potentially beneficial effects of muscle fiber type switching in the prevention and treatment of metabolic diseases.

From evidence based bioethics to evidence based social policies

Dear Editor, The comment ‘‘From evidence based bioethics to evidence based social policies’’ [1], published in the August 2007 issue, deals with an essential aspect for of interventions in public health: the effectiveness, the utility of the result, the benefit. The approach ‘‘evidence based’’ has raised an increasing interest in clinical medicine from the early nineties [2], and is often mentioned also in bioethics [3]. The author of the comment refers to an ‘‘evidence based’’ approach in bioethics and seems to suggest that useful results can justify, in an ethical perspective, any intervention. The comment is inspired by an article published in the same issue [4]: the article is, indeed, an interesting example of useful results obtained from existing information. In the case described in the paper it is easy to agree: excesses in the personal data protection could prevent from the achievement of important results in public health. In this case benefits undoubtedly exceed the uncertain advantages resulting from personal data protection. Nevertheless, this approach, if applied in other contexts and accepted as general criterion, could lead to a ‘‘utilitarianism’s tyranny’’, which does not admit a deep analysis of good and evil in themselves: the utilitarianism emphasizes only the evaluation of the consequences, profits or harmful, of our behaviours. On the contrary, a sound moral judgment must not be reduced to a calculation of the consequences or to the summation of individual good. There are human actions whose morality comes before any consequence. Apart from theoretical bases, and measuring consequentialism with the pragmatic criteria proposed by the consequentialism itself, the utilitarian/consequential approach is impracticable for at least two reasons: (a) it requires the knowledge of the future; (b) it assigns a responsibility for every consequences of our actions. Consequentialists could reply to these two points narrowing the moral responsibility to foreseeable consequences. However, from the point of view of the same consequentialism, this restriction lacks of foundation: restriction would be justifiable only if and only after having calculated that it will produce a good result; moreover each consequence potentially produces other consequences in an endless chain.

Nuclear Receptor Coregulators and Human Disease

Nuclear receptor (NR) coregulators (coactivators and corepressors) are essential elements in regulating nuclear receptor-mediated transcription. In a little more than a decade since their discovery, these proteins have been studied mechanistically and reveal that the regulation of transcription is a highly controlled and complex process. Because of their central role in regulating NR-mediated transcription and in coordinating intercompartmental metabolic processes, disruptions in coregulator biology can lead to pathological states. To date, the extent to which they are involved in human disease has not been widely appreciated. In a complete literature survey, we have identified nearly 300 distinct coregulators, revealing that a great variety of enzymatic and regulatory capabilities exist for NRs to regulate transcription and other cellular events. Here, we substantiate that coregulators are broadly implicated in human pathological states and will be of growing future interest in clinical medicine.

Real‐time multiplex allele‐specific polymerase chain reaction for genotyping of the Duffy antigen, the Plasmodium vivax invasion receptor

Duffy blood group is of major interest in clinical medicine as it is not only involved in blood-transfusion risks and occasionally in neonatal haemolytic disease, but it is also the receptor for the human malaria parasite Plasmodium vivax in the erythrocyte invasion. The aim of this study was to develop a rapid and inexpensive approach for high-throughput Duffy genotyping. This paper reported the development of a Duffy genotyping assay based on multiplex real-time polymerase chain reaction (PCR) using SYBR Green I fluorescent dye. By using this approach for Duffy genotyping we obtained the same results as that for the conventional allele-specific PCR, however, in a high-throughput assay. The Duffy genotyping of field samples demonstrated that P. vivax-infected individuals showed a significantly higher prevalence of two functional alleles than Plasmodium falciparum-infected and non-infected individuals. This finding corroborates the hypothesis that the presence of two functional alleles increases the risk of P. vivax infection. This methodology may be suitable for epidemiological studies, particularly for exploring the relationship between Duffy alleles and malaria susceptibility, and also for identification of transfusional incompatibility in blood banks.

Implantable Functional Electrical Stimulation with Inductive Power and Data Transmission System

Functional electrical stimulation (FES) has developed over the last 35 years to become a scientifically, technologically and clinically recognized field of interest in clinical medicine. FES has been applied to locomotion, grasping, ventilation, incontinence, and decubitus healing. However, all of these achievements illustrate the initial applications of FES; its true potential has not yet been realized. Recently, FES systems, which are miniaturized stimulation devices, have been utilized in the clinical setting. However, because the stimulating electrodes of the current FES devices are percutaneous electrodes, which are susceptible to wire breakage, and skin infection an implantable FES stimulating electrode has been introduced in the U.S. and Japan. In the present study, an external power supply method using radio frequency (RF) coupling and data transmission was developed for the control of the implantable FES device. In addition, we review the current understanding of FES devices and their application in clinical medicine.

Neutralizing effects of Brazilian plants against snake venoms

Medicinal plants constitute a very rich source of natural inhibitors of animal toxins, and may be used: 1) to study the mechanism of action of toxins and inhibitors; 2) to treat ophidian envenomation as a supplementary and/or alternative therapy; and 3) as models to design new drugs of interest in clinical medicine. Several Brazilian plants have been utilized in folk medicine as antiophidians. However, only a few species have been scientifically investigated and still fewer have had their active components isolated and characterized both structurally and functionally. This article presents a review of Brazilian species showing neutralizing properties against snake venoms which have been assayed in the research laboratory and characterized ethnopharmacologically in terms of: 1) the part of the plant used as antidote; 2) the respective genus and family; and 3) the main pharmacological properties related to inhibition of toxic and enzymatic activities of snake venoms and isolated toxins.

Gangliosides as receptors for biological toxins: development of sensitive fluoroimmunoassays using ganglioside-bearing liposomes.

Gangliosides, glycosphingolipids present in the membranes of neuronal and other cells, are natural receptors for a number of bacterial toxins and viruses whose sensitive detection is of interest in clinical medicine as well as in biological warfare or terrorism incidents. Liposomes containing gangliosides mimic cells that are invaded by bacterial toxins and can be used as sensitive probes for detecting these toxins. We discuss detection of three bacterial toxins-tetanus, botulinum, and cholera toxins using ganglioside-bearing liposomes. Tetanus and botulinum toxins selectively bind gangliosides of the G1b series, namely, GT1b, GD1b, and GQ1b; and cholera toxin binds GM1 very specifically. Unilamellar liposomes containing GT1b or GM1 as one of the constituent lipids were prepared by extrusion through polycarbonate membranes. To impart signal generation capability to these liposomes, fluorophore-labeled lipids were incorporated in the bilayer of liposomes. The fluorescent liposomes, containing both a marker (rhodamine) and a receptor (GT1b or GM1) in the bilayer, were used in sandwich fluoroimmunoassays for tetanus, botulinum, and cholera toxins and as low as 1 nM of each toxin could be detected. The apparent dissociation constants of liposome-toxin complexes were in 10(-8) M range, indicating strong binding. This is the first report on detection of tetanus and botulinum toxins based on specific recognition by gangliosides. The fluorescent liposomes are attractive as immunoreagents for another reason as well--they provide enormous signal amplification for each binding event as each liposome contains up to 22,000 rhodamine molecules. The present approach using receptors incorporated in bilayers of liposomes offers a unique solution to employ water-insoluble receptors, such as glycolipids and membrane proteins, for sensitive detection of toxins and other clinically important biomolecules.