Carboxylate isosteres for caspase inhibitors: the acylsulfonamide case revisited.

As part of an ongoing effort to discover inhibitors of caspase-1 with an optimized selectivity and biopharmaceutical profile, acylsulfonamides were explored as carboxylate isosteres for caspase inhibitors. Acylsulfonamide analogues of the clinically investigated caspase-1 inhibitor VRT-043198 and of the pan-caspase inhibitor Z-VAD-CHO were synthesized. The isostere-containing analogues with an aldehyde warhead had inhibitory potencies comparable to the carboxylate references. In addition, the conformational and tautomeric characteristics of these molecules were determined using 1H- and 13C-based NMR. The propensity of acylsulfonamides with an aldehyde warhead to occur in a ring-closed conformation at physiological pH significantly increases the sensitivity to hydrolysis of the acylsulfonamide moiety, yielding the parent carboxylate containing inhibitors. These results indicate that the acylsulfonamide analogues of the aldehyde-based inhibitor VRT-043198 might have potential as a novel type of prodrug for the latter. Finally, inhibition of caspase 1 and 11 mediated inflammation in mouse macrophages was found to correlate with the potencies of the compounds in enzymatic assays.

Development of irreversible diphenyl phosphonate inhibitors for urokinase plasminogen activator.

In this letter we report the synthesis and biochemical evaluation of selective, irreversible diphenyl phosphonate inhibitors for urokinase plasminogen activator (uPA). A diphenyl phosphonate group was introduced on the substratelike peptide Z-d-Ser-Ala-Arg, and modification of the guanidine side chain was investigated. A guanylated benzyl group appeared the most promising side chain modification. A k(app) value in the 10(3) M(-1) s(-1) range for uPA was obtained, together with a selectivity index higher than 240 toward other trypsin-like proteases such as tPA, thrombin, plasmin, and FXa.

Epidemiology of cancer mortality.

The level in each sex of site-specific cancers mortality is highly variable among 40 countries worldwide and somewhat less in the EU. The mortality ratio of the country worldwide with the highest upon that of the lowest cancer rate varied from 6 to 24 times in men and 6 to 17 times in women. In the EU it ranked from 3 to 10 in men and from 2 to 9 in women. Total cancer mortality had a smaller ratio (2 to 4) suggesting external and/or internal feedback mechanisms. The changes in site-specific cancer mortality rates worldwide over the years are also markedly different. A decreasing pattern since 1980 is more frequent in stomach and rectum cancer rates in each sex, in male lung cancer and in endometrium cancer. An increasing pattern is more often seen in prostate cancer, breast cancer, female lung cancer and male colon cancer. The most significant positive correlations of cardiovascular diseases are observed with rectum cancer in each sex and with endometrium cancer. Only male lung cancer correlates significantly with cardiovascular diseases. Prostate, breast and colon cancer are not positively and significantly related to cardiovascular diseases. The comparison of cancer mortality data from Belgium, The Netherlands and Denmark between 1955 and 1993 are consistent with previous results. The reliability of cancer mortality data and the role of genetic and environmental factors are discussed in two addenda. Finally it can be concluded that colon and rectum cancer behave differently at the population level. Colorectal cancer mortality data will provide misleading epidemiological results.

Cancers, mainly male, as population biomarkers for breast cancer mortality.

BACKGROUND: BCM correlates significantly with mor tality from other site-specific cancers and cardiovascular diseases for both sexes. These other mortalities could be used as independent biomarkers (predictors) of BCM allowing an evaluation of the importance of common etiological factors. METHODS: BCM (age-adjusted, 45-74 years), obtained around 1992 from 37 countries worldwide, was estimated in multivariate regression to identify the best predictors. RESULTS: Male and female biomarkers predicted BCM with a R(2) of 0.80 and 0. 69, respectively. Strongest correlation was obtained with male colon, prostate, lung, and rectum cancer and female esophagus cancer (R(2) = 0.84, P < 0.0001). The estimated independent mean percentage contribution +/- SD to BCM was 40 +/- 7 from prostate cancer, 38 +/- 9 from male colon, 13 +/- 6 from male lung and rectum cancer combined, and 9 +/- 3 from female esophagus cancer. The regression equation (1992 data) predicted mean BCM in 28 available countries from 1967 to 1991 with a mean error of 5%. BCM in individual countries was also reliably predicted from 1967 to 1991, r = 0.86 to 0.90 (P < 0.0001). In 1953, r was 0.74 (P < 0.0001). CONCLUSIONS: The evidence suggests a major influence of modifiable environmental factors common to BCM, its biomarkers, and both sexes: most likely nutrition, smoking, and alcohol intake. The results obtained with male data suggest a minor impact of sex-linked risk factors and, until recently, of treatment and early detection on BCM at the population level.

Dietary salt, nitrate and stomach cancer mortality in 24 countries. European Cancer Prevention (ECP) and the INTERSALT Cooperative Research Group.

BACKGROUND: High salt and nitrate intake are considered as risk factors for stomach cancer, but little is known about possible interactions. This ecological study examines the respective importance of both factors for stomach cancer mortality at the population level using data obtained under standardized conditions and with biochemical analyses performed in the same laboratories. METHODS: Randomly selected 24-hour urine samples from 39 populations, sampled from 24 countries (N = 5756 people for sodium, 3303 for nitrate) were obtained from the INTERSALT study. Median sodium and nitrate levels were age- and sex-standardized between ages 20-49 years and averaged per country. Ecological correlation-regression analyses were done in relation to national stomach cancer mortality rates. RESULTS: The Pearson correlation of stomach cancer mortality with sodium for the 24 countries was: 0.70 in men and 0.74 in women (both P < 0.001) and with nitrate: 0.63 (P = 0.001) in men and (P < 0.005) in women. In multiple regression of stomach cancer mortality, using sodium and nitrate as independent variables the adjusted R2 was 0.61 in men and 0.54 in women (both P < 0.001). Addition of the interaction term (sodium x nitrate) to the previous model increased the adjusted R2 to 0.77 in men, and to 0.63 in women. The analysis of this model showed that the importance of nitrate as risk factor for stomach cancer mortality increased markedly with higher sodium levels. However, the relationship of stomach cancer mortality with sodium was always stronger than with nitrate. CONCLUSIONS: Salt intake, measured as 24-hour urine sodium excretion, is likely the rate-limiting factor of stomach cancer mortality at the population level.

Twenty-four hour urinary nitrate excretion in 48 populations from 30 countries: an ECP-INTERSALT collaborative study.

BACKGROUND: There is considerable interest in the possible role of nitrate in gastric carcinogenesis, but little information on nitrate intake around the world. This is the first study to give comprehensive standardised data on nitrate excretion as a marker of intake, using 48 worldwide population samples. METHODS: Urinary nitrate excretion has been shown to be a valid measure of nitrate intake in people under 50. This report presents data on 24-hour urinary nitrate excretion from urine collections obtained in the INTERSALT study, based on random samples of men and women aged 20-49 from each of 48 population samples in 30 countries. RESULTS: There was large variation in urinary nitrate excretion both within and between samples; within-sample (individual) distributions tended to be skewed towards higher values. Median values of the samples ranged from 0.42 mmol/day (Labrador, Canada) to 3.52 (Beijing, People's Republic of China) in men and 0.44 mmol/day (Colombia) to 3.44 (Beijing) in women. Overall, median values were higher in men than women by 11% on average (higher in men in 37 of 48 population samples). Comparison by geographical region of median values for men and women combined showed relatively low values in the samples in North America and Northern Europe (range 0.46-0.88 mmol/day), slightly higher values in Western Europe and Africa (0.68-1.11), and intermediate to high values in Southern Europe, Eastern and Central Europe and India (0.86-2.47). The highest median values were found in the Far Eastern samples (up to 3.48). Median values in the Central and South American samples ranged from 0.48 mmol/day (Colombia) to 1.37 (Xingu Indians of Brazil, and Argentina). CONCLUSIONS: For the first time, these data give standardized information on urinary nitrate excretion from different geographical regions of the world, and provide a basis for the further exploration of the role of nitrate in the aetiology of disease in human populations.

On the determinants of the creatinine clearance: a population study.

The objective of this study was to define the normal urinary creatinine clearance and its determinants. The creatinine clearance was measured in both sexes in a large random Belgian population sample (BIRNH: Belgian interuniversity Research on Nutrition and Health) by measuring serum creatinine and the 24 h urinary creatinine excretion. At a mean age of 50.8 years in 2,075 men and 50.1 years in 1,933 women the mean creatinine clearance was 101 +/- 30.5 and 86.9 +/- 25.8 ml/min respectively. In multiple regression analysis the creatinine clearance in both sexes correlated negatively with age and positively with weight and 24 h urinary sodium, potassium, calcium and magnesium (all P < 0.0001). Total R2 was 0.40 in men and 0.35 in women. After adjustment for age, height and weight no significant relationship exists between the 24 h urinary creatinine clearance and either systolic or diastolic blood pressure. Serum creatinine increased with age, more so in women, and was at all ages higher in men compared to women. The creatinine clearance decreased with age in both sexes. Our study demonstrates the existence of highly significant associations between urinary cations and the creatinine clearance, independent of total caloric intake.

Forty years of evolution of mortality in Belgium and The Netherlands.

Age adjusted mortality in Belgium (B) and The Netherlands (NL) was calculated from 5 yearly age-specific death rates between the ages 45-74 and 75-85+ years. Mortality was available in Belgium from 1954 to 1991 or 1994 (depending on the cause of death) and from 1950 to 1993 in The Netherlands. In the 45-74 years age class all-cause mortality decreased in B between 1955 and 1992 with 33% in men and 48% in women. In NL this was 11% and 40%, respectively. In the age class 75-85+ it was 21% and 37% in B, and 4% and 36% in NL, respectively. Since 1980 to the last available year there was a marked decrease in mortality in the age class 75-85+ years in men and women from B and no change in NL. Wallonia always had the highest mortality, followed by B, Flanders and NL. However, recently the observed mortality in Flanders was the lowest. Mortality trends, in both age classes and sexes, were obtained between 1980 to the last available year for 11 causes of death in men and 13 in women. Among 48 possible comparisons, 38 (79%) were in favor of B, 9 in favor of NL and 1 ex aequo. Life expectancy in 1992 was compared in the 15 EU countries. For both sexes together B ranked 8th, NL 3rd. The difference in life expectancy between the two countries was 3 year in 1967 and 1 year in 1992. Flanders ranked 5th (0.3 year lower than NL) and Wallonia 14th (2.2 years lower) when substituted for B in the EU. Portugal had the best and Denmark had the worst results between 1967 and 1992). Changes in life style-fat, salt, fruit and vegetable intake and smoking habits -which occurred since 1960 in B, its regions and in NI are consistent with the changes in mortality and life expectancy. Curative medicine and medical technology cannot explain the observed differences and trends.

Mortality trends in Belgium and The Netherlands. Closing the gap.

Mean life expectancy at birth (1967-1992) increased for both sexes combined with 5.6 years in Belgium and 3.6 years in The Netherlands. Age adjusted mortality from all causes and cardiovascular diseases has been followed up from 1968 onwards to 1989 in Belgium and The Netherlands and in Flanders and Wallonia from 1971 to 1989 for each sex and two age classes, 45-74 y and 75-85 + y. Flanders and Wallonia were selected because of differences in mortality and life-style. Total mortality decreased faster in Belgium, especially in the period 1980-89, for almost all comparisons in each sex and age class and for most cardiovascular diseases. A comparison of mortality trends in the period 1980-89 among 35 countries worldwide showed a better performance in Belgium than in The Netherlands for 10 different causes of death. The mortality gap between both countries is closing, especially between The Netherlands and Flanders. The decreasing slope in mortality from all causes is explained mostly by the change in cardiovascular mortality. Medical treatment and care, which are not better in Belgium, do not explain the differences in mortality trends Observed changes in life-style, including saturated and polyunsaturated fat intake, smoking habits and salt intake are consistent with the observed mortality changes.

Secular trends in cerebrovascular mortality.

Since 1950 a marked decrease in cerebrovascular mortality has occurred in most Western countries. To evaluate whether changes in the pharmacological treatment of hypertension, introduced during the period observed (1950-87), have influenced this downward trend the linear time-trends over the period considered were calculated. Mass treatment of hypertension at the population level started in the early 1970s. Before this period a marked decrease in cerebrovascular mortality had already occurred. Moreover, the linear time trends were highly significant over the whole period with several correlation coefficients of > 0.98. The decrease in cerebrovascular mortality can best be explained by a decreased salt and saturated fat intake in the populations considered. In several Eastern European countries cerebrovascular mortality has increased. This runs parallel with an increase in all-cause mortality and an increase in ischaemic heart disease mortality and can be explained by the high saturated fat intake of these populations. The data show that important changes in cerebrovascular mortality are also occurring in the older age groups, e.g. 70-74 and 80-84 years. Epidemiological data point towards nutrition as playing an important role in the evolution of cerebrovascular mortality over the period considered.

Bread as a source of salt: an international comparison.

OBJECTIVE: The salt (NaCl) content of bread, obtained from Belgium and 25 other regions or countries worldwide, was analyzed to evaluate the importance of bread as a source of dietary salt in a population. METHODS: A total of 1166 dried bread samples were analyzed using a hot HCl extraction technique followed by flame photometry and performed by the same laboratory technician in Leuven (Belgium); 534 samples from Leuven were analyzed over 10 time periods from 1967-73 to 1992 together with 562 samples from 11 other European countries, 44 from the United States and Peru, and 26 from Asia. RESULTS: The average mean salt content of fresh bread (= dried bread times 0.6) in European countries was 12.4 +/- 1.7 g/kg for white and 13 +/- 1.0 g/kg for brown bread. In Japan and Korea it was about 8.5 g/kg and in Pakistan, Thailand, Nepal, and Laos about 5 g/kg. The mean sodium/potassium ratio with Na and K in mmol was 8.0 for white and 4.5 for brown bread, much higher than the recommended value of 1.0. Bread with a very low salt content was found in certain areas of Peru, Spain, and Italy. CONCLUSION: The overall salt content of bread in Western countries is excessive, and a gradual reduction is highly desirable.

Cancer mortality and age: relationship with dietary fat.

Highly significant correlations exist between total cancer mortality and age expressed by a log total cancer mortality-log age equation (mean r2 0.991 in men and 0.996 in women) or by a second-order polynomial equation including age and age2 (mean r2 0.999 in men and 0.998 in women). In all countries considered (n = 32), the second-order term of age is negative, indicating a decrease in the rate of rise of log cancer mortality at older age. This could be explained by a lesser accuracy of the diagnosis of cancer at older age, by selective survival of subjects resistant to cancer, by a cohort effect, or by a decrease in the rate of growth of cancer at older age. The decrease in the rate of rise of cancer mortality after 65 years of age occurs in all countries and applies to nearly all cancers except breast cancer in women after 75 years of age. A high cancer mortality in a country is characterized by a low intercept and a steep slope of the log mortality-log age equation. These parameters are influenced by dietary fat intake in men and women, with saturated fat increasing total cancer mortality and the ratio of polyunsaturated to saturated fat and the ratio of unsaturated to saturated fat decreasing it. The data on dietary fat were obtained from the Food and Agriculture Organization of the United Nations (FAO) food balance sheets (n = 32) and from dietary surveys (n = 21). Both vary in the same direction, but only the dietary data from the FAO correlate significantly with cancer mortality. This finding points toward a relationship between the level of dietary fat intake and total cancer mortality at the population level.

Relationship between dietary protein intake and serum urea, uric acid and creatinine, and 24-hour urinary creatinine excretion: the BIRNH Study.

Relationships between dietary protein intake of a large free-living group and serum creatinine (Cr), urea and uric acid levels have been studied, based on data obtained from the BIRNH (Belgian Interuniversity Research on Nutrition and Health) study. Highly significant correlations were found in both sexes for total protein, as well as for animal and vegetable protein intake. In a subgroup, the relationship between dietary protein intake and 24-hour urinary Cr excretion has also been studied. The range of +/- 2 SD of the mean for total protein and animal and vegetable protein daily intakes resulted in a calculated range of 24-hour Cr excretion of 430, 317 and 209 mg/24 hours in men and of 192, 169 and 125 mg/24 hours in women, respectively. The 24-hour urinary Cr excretion was significantly influenced by both dietary protein and polyunsaturated fat intake.

Worldwide mortality changes from all causes and from cardiovascular diseases between 1968 and 1988.

The worldwide changes in mortality from 35 countries, between 1968 and 1988, have been analyzed in four age classes between 45 and 85+ years and in both sexes, together with years gained in life expectancy at age one between 1967 and 1990. The most important decreases have been seen in populations with important changes in life style, primarily nutritional, such as in East Asia, Australia, Finland, Austria, France, Switzerland, Portugal, Belgium, F.R.G. and Spain. Less beneficial changes were observed in Sweden and The Netherlands. Unsatisfactory changes were observed in Norway, Denmark and especially in the East European countries. The small increase in life expectancy at age one (+1.5 year) observed in Denmark between 1967 and 1990 was situated between that of the former German Democratic Republic and of Czechoslovakia, +1.6 and +0.3, respectively. However, marked differences exist among sexes and age classes. The changes obtained for all-cause mortality in the 75-84 years age class are better than in the 45-64 years age class. All these observations cannot be explained by better medical treatment only and point towards nutrition as the most important causal factor.

The relationship between urinary cations obtained from the INTERSALT study and cerebrovascular mortality.

An epidemiological study on the relationship between 24 hour urinary sodium, potassium, calcium, magnesium and creatinine (Creat), as obtained from the INTERSALT study, and cerebrovascular disease (CVA) mortality in the age-standardised group 45-74 years, was conducted using data from 25 countries worldwide. A significant positive relationship was observed by multivariate analysis between cerebrovascular disease mortality and 24 hour urinary Na excretion in men, with Na/K ratio in women and with Na/Creat ratio in all groups. A significant negative correlation was found between the 24 hour urinary magnesium excretion and CVA mortality in men and in men and women averaged, while 24 hour urinary potassium excretion correlated significantly and negatively with CVA mortality in women. No significant relationship between systolic and diastolic blood pressure, 24 hour urinary calcium excretion and BMI with CVA mortality could be established. A log10 transformation revealed a significant positive relationship between Ca/Mg ratio with CVA mortality in men as well as in the group of men and women averaged. A significant negative correlation between CVA mortality and 24 hour creatinine excretion was found. This relationship was stronger in men and could point to a protective effect of protein intake. The findings also point to a direct relationship between dietary cation intake and CVA mortality.

Dairy fat, saturated animal fat, and cancer risk.

The relationship between the per person supply of fat from dairy products and lard and cause-specific cancer mortality was examined using 1979-1981 FAO data from 36 countries. Significant correlations (P less than 0.01) were found between dairy and lard fat intake and total, breast, prostate, rectal, colon, and lung cancer. Significant relationships between site-specific cancer mortality and ischemic heart disease mortality could also be established. Hormone-dependent cancers significantly correlate with both hormone-dependent and non-hormone-dependent cancers of the opposite sex, pointing toward other than sex-linked factors as an explanation. The level of saturated fat intake provides the most plausible link for the relationship between the cancers considered and ischemic heart disease mortality. Our findings support the concept of the important role saturated fat plays in cancer promotion.