We report the prevalence of end-stage diabetic nephropathy treated by hemodialysis in the Lazio region, which includes the City of Rome, with a total population of over 5 million people. The percentage of diabetic patients among those attending the dialysis centers was 5% (n = 59), which is below the figures reported for both Northern Europe or Southern Italy (Sicily). A higher number (40%) of patients were affected by non-insulin treated diabetes. This figure is similar to that reported in Southern Italy, but highly discordant from the Northern European data where the large majority of diabetics on hemodialysis are affected by insulin-treated diabetes. Genetic differences and the type of diet may account for the difference in prevalence of end-stage nephropathy between Northern and Southern Caucasians affected by diabetes.

Adult↗

PubMedDate not supplied

On the origins of the Mendelian laws.

The two laws usually attributed to Mendel were not considered as laws by him. The first law, the law of independent segregation occurs in Mendel's paper as an assumption or hypothesis. Hugo de Vries refers to this as a law discovered by Mendel. This appears to be the first use of an expression equivalent to Mendel's law. In his paper de Vries did not associate the observable characters with structures having a causitive role. That was done by Correns, who transformed the law of segregation of characters into a law of the segregation of anlagen. The second law, the law of independent assortment, is present in embryonic form in Mendel's paper. Here the independent assortment of characters appears as a secondary conclusion to a series of experiments involving several pairs of traits. Mendel repeats the primary conclusion later in the paper but not the secondary one. This leads us to believe that he considered the secondary conclusion as of lesser importance. We note in this context that the 9:3:3:1 ratio commonly associated with the idea of independent assortment, and attributed to Mendel, also does not occur in his paper. A careful reading of the papers of his discoverers shows it was Correns who first drew attention to this ratio. However, he did not formulate the second Mendelian law even though it was clearly implied. Neither was it stated by de Vries. Indeed, the first clear separation of the two laws and the naming of the second law was by T. H. Morgan some 13 years later.

Genetics↗

PubMedDate not supplied

Mendel had no "true" monohybrids.

Mendel's experiments in hybridizing peas started in 1856 and ended in 1863. When one attempts to fit the described experiments--in the sequence indicated in the paper--into those limits some serious implications emerge with regard to parental types needed and the scheduling of the experiments. If Mendel had to develop the parental types of his monohybrid and dihybrid crosses and then do the experiments he described, 8 years would not have been a sufficient amount of time. We believe that his original true-breeding varieties differed in more than one trait on the basis of a logical analysis of breeding relationships. It follows first that his "monohybrid" experiments were performed with varieties in several traits but that in each offering he concentrated his attention on only one, second that he had the parental lines for his dihybrid and trihybrid experiments on hand before he started those experiments.

Austria↗

PubMedDate not supplied

Role of de Vries in the recovery of Mendel's work. I. Was de Vries really an independent discoverer of Mendel?

Recently, doubt has been cast on the view that de Vries developed the idea of disjunction independently of Mendel. Arguments are based on de Vries' own writings that showed the F2 data of his numerous crosses are reported as 3:1 ratios only after 1900. They also show that his theory of inheritance becomes quasi Mendelian only after 1900. The authors of this review paper cannot but agree with de Vries' critics that he did not develop his law of disjunction independently of Mendel. They also raise some questions that, hopefully, will lead to a reanalysis of de Vries' theory of inheritance in 1900.

Botany↗

PubMedDate not supplied

Chi-square and Mendel's experiments: where's the bias?

Mendel has been accused of "cooking" his data to meet a particular hypothesis. The earliest time he could have formulated an hypothesis in the course of his experiments was at the end of the second year of experiments 1 and 2. If he knew what to expect as the result of his first two pea-seed experiments, one might expect the chi-square values of subsequent experiments to exhibit a trend toward smaller values. However, when the individual experiments are, each in turn, subjected to a chi-square test, there is no evidence of the expected trend. With few exceptions, the data show no systematic variation in a particular direction. In our view, the suggestion of bias is not supported.

Genotype↗

PubMedDate not supplied