Leiomyosarcoma of the Inferior Vena Cava: A Case Series and Review of the Literature.

BACKGROUND: Leiomyosarcoma of the inferior vena cava (IVC) is an exceedingly rare smooth muscle sarcoma. Approximately 300 cases have been described in the literature, and further research is needed to understand the disease and guide its management. Surgery remains the only potential curative measure. METHODS: A retrospective chart review of patients who underwent surgical resection of IVC leiomyosarcoma at our institution over the past 3 years was performed. The patients were identified using a prospectively maintained database. RESULTS: Three patients with leiomyosarcoma of the infrahepatic IVC underwent radical resection carried out by a team of surgical oncologists and vascular surgeons. There were 2 males (66.7%) and 1 female (33.3%). Mean age at diagnosis was 60.3 years (range 43-78). Mean tumor size was 12.2 cm (range 5.6-22). The mean operative time was 320 min (range 180-421), mean estimated blood loss was 1,300 mL (100-2,000) mL, and average length of stay 8.67 days (6-12). All patients achieved grossly negative margins (R1 or R0 resections) and are alive with a mean overall survival of 21 months (range 12-30). Patient 1 was a 60-year-old man who presented with metachronous skin leiomyosarcomas at 2 different sites. He underwent PET/CT scan that revealed an IVC mass. Resection of the middle segment of the IVC and right kidney was performed with reconstruction with polytetrafluorethylene (PTFE) graft. Patient 2 was a 78-year-old man with an incidentally found a 9-cm IVC tumor. Resection of the tumor was performed, and no reconstruction was needed since the tumor had a completely extraluminal growth pattern. Patient 3 was a 43-year-old woman who presented with abdominal pain. Her work-up showed a 15-cm IVC mass. She underwent resection of the middle segment of the IVC, right nephrectomy, and cholecystectomy with reconstruction of the IVC with PTFE graft. CONCLUSIONS: Surgical resection is the mainstay of treatment in patients with leiomyosarcoma of the IVC. A collaborative approach involving surgical oncologists and vascular surgeons ensures adequate resection with functional reconstruction to achieve the best patient outcomes.

Fatty acid composition of achenes of Cirsium taxa (Asteraceae, Carduoideae) from Turkey.

The fatty acid compositions and total oil contents in achenes of 22 Cirsium taxa collected from different natural habitats in Turkey were investigated. The range of total fat in the taxa varied from 1.7% to 13.3%. The taxa contained palmitic (C16:0), stearic (C18:0), oleic (C18:1n-9), linoleic (C18:2n-6), and α-linolenic (C18:3n-3) acid. Polyunsaturated fatty acids had the highest level, ranging from 52.1% to 75.2% (C18:2n-6) and 0.5%-17.3% (C18:3n-3). Total saturated (6.9%-17.4%), monounsaturated (11.7%-28.9%), and polyunsaturated (57.4%-79.9%) fatty acids varied substantially, whereas total unsaturated fatty acids ranged from 70.6% to 91.3%. Considerable variation was observed (P<0.05) within each taxon for these fatty acids, especially α-linolenic acid (C18:3n-3). Fatty acid compositions of the 22 taxa were compared by cluster analysis (UPGMA) and principle component analysis (PCA) based on six major fatty acids. This is the first report on the lipid content and fatty acid composition of achenes of Cirsium taxa growing in different areas of Turkey. Fatty acid profiles, relative proportions and levels of fatty acids can be used as additional biochemical markers in the taxonomy of Cirsium.

Renal systems biology of patients with systemic inflammatory response syndrome.

A systems biology approach was used to comprehensively examine the impact of renal disease and hemodialysis (HD) on patient response during critical illness. To achieve this, we examined the metabolome, proteome, and transcriptome of 150 patients with critical illness, stratified by renal function. Quantification of plasma metabolites indicated greater change as renal function declined, with the greatest derangements in patients receiving chronic HD. Specifically, 6 uremic retention molecules, 17 other protein catabolites, 7 modified nucleosides, and 7 pentose phosphate sugars increased as renal function declined, consistent with decreased excretion or increased catabolism of amino acids and ribonucleotides. Similarly, the proteome showed increased levels of low-molecular-weight proteins and acute-phase reactants. The transcriptome revealed a broad-based decrease in mRNA levels among patients on HD. Systems integration revealed an unrecognized association between plasma RNASE1 and several RNA catabolites and modified nucleosides. Further, allantoin, N1-methyl-4-pyridone-3-carboxamide, and N-acetylaspartate were inversely correlated with the majority of significantly downregulated genes. Thus, renal function broadly affected the plasma metabolome, proteome, and peripheral blood transcriptome during critical illness; changes were not effectively mitigated by hemodialysis. These studies allude to several novel mechanisms whereby renal dysfunction contributes to critical illness.

Docosahexaenoic acid in maternal and neonatal plasma phospholipids and milk lipids of Taiwanese women in Kinmen: fatty acid composition of maternal blood, neonatal blood and breast milk.

BACKGROUND: Docosahexaenoic acid (DHA) is a long-chain omega-3 polyunsaturated fatty acid (LCPUFA) that is critically important for the structure, development and function of the retina and central nervous system (CNS), ultimately contributing to improved cognition. It is known that the DHA content of breast milk is positively correlated with maternal DHA intake. Since there is a lack of information about the DHA status of pregnant and lactating women in rural Taiwan. The aims of the present study were to: 1) assess the DHA status of mothers and babies in urban setting, and 2) determine the content of DHA in the milk of nursing mothers. METHODS: All pregnant women who attended the Obstetrics and Gynecology Outpatient Clinic of Kinmen Hospital on Kinmen Island in Taiwan between May 1 and May 30, 2011 were invited by research nurses to enroll in the study. The maternal blood sample was obtained on the day of their delivery. Cord blood was collected by the obstetrician following delivery. Participants were asked to visit the doctor forty-two days after the delivery, at which time a nurse collected breast milk on the day mothers were visiting the doctor for post-natal well-baby check-up. RESULTS: The DHA percentages of maternal and neonatal plasma phospholipids were 5.16% and 6.36%, respectively, which are higher than values reported for most populations elsewhere in the world. The DHA percentage for the breast milk of Kinmen mothers was also high (0.98%) relation to international norms. The DHA proportions in maternal and neonatal plasma phospholipids were positively correlated (r = 0.46, p = 0.01). CONCLUSIONS: We show that the DHA status of mothers and newborns on Kinmen Island is satisfactory, thereby providing an evidence-based argument for promoting breastfeeding in Taiwan.

The importance of community in academic health centers.

BACKGROUND: A strong sense of community in any organization, whether it is a small business or a large academic medical center, positively impacts on productivity, efficiency, and morale and makes for an enjoyable workplace. Striking a balance between institutional interests and those of the individual is an ongoing challenge that demands vigilance on the part of faculty and administrators. A faculty comprising self-absorbed individuals, no matter how accomplished they are, will eventually devolve into dysfunction. As the emphasis on extramural grants and clinical productivity has intensified in recent years, this balance has tilted in favor of individualism at the expense of student success and community spirit. SUMMARY: This article examines factors that tend to undermine community and human behaviors that can counter these negative forces. CONCLUSIONS: If the various stakeholders in the academic health center--deans, chairpersons, faculty, students and staff--all take stock of their responsibilities and commit themselves to restoring a healthier balance between self-interest and institutional missions, beneficial returns are likely in terms of higher quality education and clinical care, increased research productivity and a more vibrant and enjoyable workplace.

Acanthosis nigricans predicts the clustering of metabolic syndrome components in Hispanic elementary school-aged children.

BACKGROUND: Acanthosis nigricans (AN) is a dermatologic condition associated with hyperinsulinemia, a marker of insulin resistance that is the principal abnormality in metabolic syndrome (MetS). We examined the association of AN with the clustering of MetS components. METHODS: A cross-sectional study was conducted in an urban school-based health center in New Mexico. Students without diabetes were evaluated for AN, a family history of type 2 diabetes, body mass index (BMI), and MetS components. The clustering of MetS components by BMI category and AN status was assessed by comparing the group means of summed average z-scores of fasting insulin, triglycerides, high-density lipoprotein-cholesterol, and systolic blood pressure among the students. A multivariate model with BMI category and AN status controlling for Tanner stage was performed to identify the variables associated with the clustering of MetS components. RESULTS: Complete data were available for 90 children (age, 9.7±1.4 years; 94% Hispanic; 60% female). In multivariate modeling of MetS cluster z-score, significant differences were found between the students with BMI <85th percentile [-0.27; 95% confidence interval (95% CI)=-0.42 to -0.11] and (a) the students with BMI 85th-94.9th percentile with AN (0.74; 95% CI=0.17-1.31) and (b) the students with BMI ≥95th percentile with AN (0.86; 95% CI=0.54-1.18). No significant differences in the MetS cluster z-score were seen between the students with BMI <85th percentile and those with BMI 85th-94.9th percentile without AN (0.24; 95% CI=-0.33 to 0.81) or those with BMI ≥95th percentile without AN (0.31; 95% CI=-0.13 to 0.75). CONCLUSIONS: Overweight/obese Hispanic elementary school-aged children with AN exhibit clustering of MetS components and could benefit from early intervention.

How much longer will Africa have to depend on western nations for support of its capacity-building efforts for biomedical research?

Advances in biomedical research techniques have resulted in the conquest of many diseases and the improvement in the health and well-being of populations, yet sub-Saharan Africa continues to lag behind western nations in terms of research infrastructure and capacity. The increasing numbers of links and collaborations between western institutions of higher learning and teaching hospitals and universities in sub-Saharan Africa have undoubtedly promoted scholarly research activity on the continent. However, most of the research agenda is, understandably, dominated by western collaborators who provide the much needed funding. Given the recent exposure by events on Wall Street of the frailties of western economies, Africa urgently needs to look inwards in its quest to train biomedical researchers of repute and to secure funding for its capacity-building needs.

Fatty acid and amino acid compositions of selected wild-edible mushrooms consumed in Turkey.

The fatty acid and amino acid compositions of 11 mushroom species commonly consumed were collected from the East Black Sea region of Turkey and analyzed. All species were characterized by a high content of linoleic acid (C18:2n-6) and glutamic acid. The highest content of linoleic acid (78.0%) and glutamic acid (29.4 µg/mg dry weight [d.w.]) was found in Agaricus arvensis and the lowest in Cantharellus tubaeformis, 19.8% and 10.9 µg/mg d.w., respectively. The average content of amino acids for all species was 148 µg/mg d.w. Overall, these results demonstrate that the 11 different kinds of wild edible mushrooms gathered from the region represent substantial sources of fatty acids and amino acids that are essential in the diet of humans. Quality of the mushroom protein compares favorably with the FAO/WHO Standard. The present study demonstrates that macrofungi from the East Black Sea region (Turkey) are a good source of many nutrients essential to human well-being.

Differences in fatty acid composition between aquatic and terrestrial insects used as food in human nutrition.

Edible insects may be a source of long-chain polyunsaturated fatty acids (LC-PUFA). The aim of this article is to test for differences in aquatic and terrestrial insects used in human nutrition. We implemented linear models and discovered that differences in the proportion of LC-PUFA between aquatic and terrestrial insects do exist, with terrestrial insects being significantly richer in particular omega-6 fatty acids. In conclusion, any kind of insect may provide valuable sources of LC-PUFA. Because terrestrial insects are more abundant and easier to collect, they can be considered a better source of LC-PUFA than aquatic ones.

Sources of variation in estimates of lean body mass by creatinine kinetics and by methods based on body water or body mass index in patients on continuous peritoneal dialysis.

OBJECTIVE: We identified factors that account for differences between lean body mass computed from creatinine kinetics (LBM(cr)) and from either body water (LBM(V)) or body mass index (LBM(BMI)) in patients on continuous peritoneal dialysis (CPD). DESIGN: We compared the LBM(cr) and LBM(V) or LBM(BMI) in hypothetical subjects and actual CPD patients. PATIENTS: We studied 439 CPD patients in Albuquerque, Pittsburgh, and Toronto, with 925 clearance studies. INTERVENTION: Creatinine production was estimated using formulas derived in CPD patients. Body water (V) was estimated from anthropometric formulas. We calculated LBM(BMI) from a formula that estimates body composition based on body mass index. In hypothetical subjects, LBM values were calculated by varying the determinants of body composition (gender, diabetic status, age, weight, and height) one at a time, while the other determinants were kept constant. In actual CPD patients, multiple linear regression and logistic regression were used to identify factors associated with differences in the estimates of LBM (LBM(cr)LBM(V). The differences in determinants of body composition between groups with high versus low LBM(cr) were similar in hypothetical and actual CPD patients. Multivariate analysis in actual CPD patients identified serum creatinine, height, age, gender, weight, and body mass index as predictors of the differences LBM(V)-LBM(cr) and LBM(BMI)-LBM(cr). CONCLUSIONS: Overhydration is not the sole factor accounting for the differences between LBM(cr) and either LBM(V) or LBM(BMI) in CPD patients. These differences also stem from the coefficients assigned to major determinants of body composition by the formulas estimating LBM.

Vitamin D status of seminomadic Fulani men and women.

The purpose of this study was to assess the vitamin D status of Fulani men and women in northern Nigeria. The Fulani are seminomadic pastoralists whose culture, economy, and diet are centered on cattle. Most of the foods consumed by the Fulani are not good sources of vitamin D. Also being Muslim, the women do not derive much benefit from the vitamin D-generating effects of sunlight due to their dress habits. Furthermore, childhood rickets is common in the region. Serum was collected from 22 Fulani men (age, 47.6 +/- 8.3 years; body mass index [BMI], 21.1 +/- 3.2 kg/m2) and 29 women (age, 55.5 +/- 13.5 years; BMI, 21.6 +/- 3.1 kg/m2) in rural northern Nigeria and analyzed for 25-hydroxyvitamin D2 and D3 using ultraperformance liquid chromatography coupled with mass spectrometry Eighty-three percent of the women and 45% of the men had serum 25-hydroxyvitamin D levels in the hypovitaminosis D range (10-30 ng/mL). In the males, there was a strong negative correlation between serum vitamin D and BMI (r = -0.49, p = .022) and percent body fat (r = -0.51, p = .015). No such correlations were observed in the Fulani women. Our main conclusion is that about half the men and most of the women in the Fulani community where this study was conducted are inadequately nourished with respect to vitamin D. A high prevalence of hypovitaminosis D indicates an elevated risk for rickets in children and bone fractures in adults.

Lipid profiles and trans fatty acids in serum phospholipids of semi-nomadic Fulani in northern Nigeria.

The Fulani are semi-nomadic pastoralists of West Africa whose diet, culture, and economy are centred on cattle. Previous studies have shown that the Fulani of northern Nigeria derive 50% of their total calories from fat and 30% of their calories from milk, cheese, yogurt, and butter oil that contain significant amounts of trans fatty acids (TFAs), primarily vaccenic acid, which raise total serum cholesterol and low-density lipoproteincholesterol (LDL-C), and lower high-density lipoprotein-cholesterol (HDL-C). The study was conducted to know how the consumption of relatively large amounts of dairy products by adult Fulani affected the TFA content of their serum phospholipids. Blood samples were collected from 22 male and 29 female Fulani, aged 35-60 years, who were living in rural areas of Gombe state in northeastern Nigeria. The total serum phospholipid fraction was isolated, and its fatty acid composition was determined. Surprisingly, vaccenic acid was not detected, and three other TFAs--18:1-t6, 18:1-t9, and 18:2-t9,t12--together accounted for only 0.16% of the total fatty acid. The mean serum total cholesterol, LDL-C, and triglyceride concentrations of the subjects were within the normal range for populations in developed countries; however, at 32 mg/dL, the mean serum HDL-C concentration of the Fulani males was slightly below the lower limit of the reference range. No correlations were observed between the total TFA percentage or that of the three individual TFAs and any of the parameters of the serum lipid profile. These findings indicate that, with respect to TFAs at least, the fatty acid pattern of the serum phospholipids of Fulani pastoralists does not reflect the high TFA content of their traditional diet. Despite the consumption of rumenic acid-rich dairy products, for unknown reasons, the semi-nomadic Fulani manage to maintain a low level of TFAs in their blood and a relatively healthful serum lipid profile. While the mechanism that accounts for this disconnect between the consumption of TFAs by Fulani pastoralists and the proportion of TFAs in their serum phospholipids is obscure, possibilities include discrimination against rumenic acid during the process of triglyceride synthesis and chylomicron synthesis in the intestine and the preferential oxidation of TFAs by Fulani the people compared to other ethnic groups.

Dialysis-associated hyperglycemia: manifestations and treatment.

PURPOSE: Dialysis-associated hyperglycemia (DAH), is associated with a distinct fluid and electrolyte pathophysiology. The purpose of this report was to review the pathophysiology and provide treatment guidelines for DAH. METHODS: Review of published reports on DAH. Synthesis of guidelines based on these reports. RESULTS: The following fluid and solute abnormalities have been identified in DAH: (a) hypoglycemia: this is a frequent complication of insulin treatment and its prevention requires special attention. (b) Elevated serum tonicity. The degree of hypertonicity in DAH is lower than in similar levels of hyperglycemia in patients with preserved renal function. Typically, correction of hyperglycemia with insulin corrects the hypertonicity of DAH. (c) Extracellular volume abnormalities ranging from pulmonary edema associated with osmotic fluid shift from the intracellular into the extracellular compartment as a consequence of gain in extracellular solute (glucose) to hypovolemia from osmotic diuresis in patients with residual renal function or from fluid losses through extrarenal routes. Correction of DAH by insulin infusion reverses the osmotic fluid transfer between the intracellular and extracellular compartments and corrects the pulmonary edema, but can worsen the manifestations of hypovolemia, which require saline infusion. (d) A variety of acid-base disorders including ketoacidosis correctable with insulin infusion and no other interventions. (e) Hyperkalemia, which is frequent in DAH and is more severe when ketoacidosis is also present. Insulin infusion corrects the hyperkalemia. Extreme hyperkalemia at presentation or hypokalemia developing during insulin infusion require additional measures. CONCLUSIONS: In DAH, insulin infusion is the primary management strategy and corrects the fluid and electrolyte abnormalities. Patients treated for DAH should be monitored for the development of hypoglycemia or fluid and electrolyte abnormalities that may require additional treatments.

Nutrient content of carob pod (Ceratonia siliqua L.) flour prepared commercially and domestically.

Although the fruit of the carob tree (Ceratonia siliqua L. Fabaceae) is nutritious and widely available in Turkey, especially in West and South Anatolia, much remains to be learned about its nutrient composition. The main goal of our study was to determine if there are differences in the content of certain nutrients in commercially-prepared carob flour (CPCP) and domestic or home-prepared carob powder (HPCP). Sucrose was the main sugar in CPCP and HPCP. Total protein was 40% lower in CPCP than HPCP due mainly to decreases in the content of several essential amino acids. However, except for lysine in CPCP, HPCP and CPCP compared favourably to a WHO protein standard. There were large differences in terms of their content of the two essential fatty acids, linoleic and alpha-linolenic acid, and the linoleic acid/alpha-linolenic acid ratio was 3.6 for CPCP, and 6.1 for HPCP. Manganese and iron were 2.5-fold higher in HPCP than CPCP. This study demonstrates that carob flour prepared in either the household or industrially is a good source of many, but not all essential nutrients, and that commercial processing of carob fruit into flour seems to affect its content of several important nutrients.

Symptomatic Hyperglycemia in a Patient with Dialysis Ascites.

An anuric woman with ascites rapidly developed extreme hyperglycemia and seizures after hemodialysis. During development of hyperglycemia, the decrease in serum sodium concentration (Δ[Na]) was nearly twice the value predicted by a formula accounting for the degree of hyperglycemia and the intracellular-to-extracellular volume ratio. The prediction assumed that ascitic fluid is part of the extracellular volume. Potential contributors to the development of seizures include the rapid development of severe hypertonicity, a remote history of seizure disorder and development of dialysis disequilibrium syndrome. Observations in peritoneal dialysis suggest that fluid with sodium concentration lower than in the ascitic fluid is transferred from the abdominal cavity into the blood during rapid development of hyperglycemia. In this case, Δ[Na], which determines the tonicity level expected after correction of hyperglycemia, resulted from exit of both intracellular and ascitic fluid into the extracellular compartment and, therefore, ascitic fluid functions as an extension of the intracellular fluid.

Promoting collaborations between biomedical scholars in the U.S. and sub-Saharan Africa.

The premise of this piece is that a priority of international health should be to increase the number of investigators in the US and other developed countries who engage in research and other kinds of scholarly work in underdeveloped parts of the world, particularly sub-Saharan Africa where the overall disease burden is the highest and the gap in biomedical research infrastructure is the widest. The author's aim is to encourage medical students, resident doctors, and medical school faculty to devote a part of their career to teach, acquire clinical skills, or participate in research with health professionals at teaching hospitals in Africa. After briefly describing the thinking that led the author to Nigeria 30 years ago to teach and study biochemical aspects of health problems in rural and urban areas, he discusses some of the factors one needs to consider before entering into an international partnership, including identifying the right foreign collaborators, selecting a suitable research site, setting realistic goals, learning the local culture and indigenous language, and defining a theme for your program. Lastly, the piece points out potential pitfalls and problems that are often overlooked or underestimated in the early phases of planning an international partnership, including lukewarm institutional support at home, inflexible institutional review boards, dominance of the program by the US partner, maintaining continuity, and striking the right balance between scholarly work and humanitarian efforts. My hope is that US students and faculty in the health professions who read this piece will be stimulated and encouraged to consider how they might integrate into their curriculum or academic life visits lasting several months or more each year during which they would teach or train others or engage in research at a teaching hospital in some country in Africa.

Low docosahexaenoic acid in the diet and milk of women in New Mexico.

Because docosahexaenoic acid (DHA) is critical for the development of the nervous system, especially during the first year of life, the content of DHA in human milk is important for the well-being of exclusively breastfed infants. The aim of this study was to determine the fatty acid composition, including DHA, of the breast milk fat and serum phospholipids of women in New Mexico, and to correlate these data with dietary fatty acid content. Samples of blood and breast milk, 3-day diet records, and information on dietary supplement use were obtained from 29 women. Eligible subjects were nonsmokers, aged 18 to 40 years, lactating for 1 to 6 months, and not pregnant, taking immunosuppressive drugs, or diagnosed with diabetes. The mean fat content of the breast milk was 3.37+/-2.34 g/dL. The percentage of DHA in the milk fat was very low (0.11%) relative to international norms (0.2% to 0.4%) and could be explained by the women's low intake of DHA (33 to 58 mg/day). These data can be explained by the fact that the subjects were not taking DHA supplements or consuming foods that are good sources of DHA. Correlations were found between the percentages of DHA in the serum phospholipids and milk fat. The findings underscore the need for educating lactating women about food sources of DHA. Educational opportunities could occur in conjunction with other education postdelivery or during postnatal clinic visits.

Pulmonary function correlates with body composition in Nigerian children and young adults with sickle cell disease.

Sickle cell disease (SCD) is associated with impaired growth and skeletal maturation. Decreased fat-free mass (FFM) and body fat (BF) have been reported in Nigerian children with SCD relative to healthy age- and gender-matched controls. Pulmonary abnormalities, including reduced forced vital capacity (FVC), forced expiratory volume in one second (FEV(1)) and total lung capacity (TLC), have also been described in children with SCD. Since undernutrition is common in sub-Saharan Africa, we were interested in knowing the relationship between pulmonary function and body composition in Nigerian children and young adults with SCD. Body composition was determined using bioelectrical impedance and pulmonary function was assessed by spirometry in Nigerian children and young adults aged 7-35 years (n = 102) as well as healthy age-and gender-matched controls (n = 104). Age-adjusted data revealed 19-26% lower FFM for male (P < 0.001) and female (P < 0.001) subjects with SCD relative to the controls. FVC, FEV(1) and PEF were also significantly reduced in male and female children and young adults with SCD compared to their control counterparts. For both male and female patients and controls, FVC, FEV(1) and PEF correlated positively with FFM (P < 0.001). PEF for the female subjects with SCD diverged progressively with increasing age relative to the controls and the rate of change was significantly lower (P < 0.001). We conclude that pulmonary function is reduced in Nigerian children and young adults with SCD compared to controls and that for both groups, pulmonary function is directly related to body composition. These findings underscore the need for early nutritional intervention for children with SCD.

Twenty-first Century ethics of medical research involving human subjects: achievements and challenges.

The field of ethics in medical research has seen important developments in the last three decades, but it also faces great challenges in the new century. The purposes of this report are to examine the current status of ethics of medical research involving human subjects and the nature of the ethical challenges facing this research, to identify the weakness of the current system of safeguards for ethical research, and to stress the importance of the ethical character of the researcher, which is the safeguard that has the greatest potential for protecting the research subjects. Researchers appreciate the risks of human medical research that create ethical dilemmas and the need for an ethical compromise in order to proceed with the research. The main elements of the compromise, formulated primarily from experiences in the Second World War, include: (1) the dominant position of the ethical principle of autonomy; (2) the demand for a signed informed consent; (3) the likelihood of improving health with the research protocol, which must be approved by a duly appointed supervising committee; and (4) an acceptable risk/benefit ratio. The main weakness of this set of safeguards is the difficulty with obtaining a truly informed consent. The new challenges to ethical medical research stem from certain types of research, such as genetic and stem cell research, and from the increasing involvement of the industry in planning and funding the research studies. Developing medical researchers with an ethical character and knowledge about ethics in medicine may be the most effective safeguard in protecting participants of medical research experiments.