Cavernous transformation of the portal vein associated to multiorgan developmental abnormalities

Initial diagnosis of cavernous transformation of the portal vein (portal cavernoma) is rarely made in adults. Its main clinical manifestation is upper gastrointestinal hemorrhage due to variceal bleeding. More rarely, diagnosis is made from obstructive jaundice. In children, this condition is frequently associated to prehepatic portal hypertension and congenital anomalies, the most frequent of which are atrial septal defects or malformations of the biliary tract or of the inferior vena cava. We describe here a case of a 23-year-old female presenting with massive hematemesis due to the presence of esophageal and small intestinal varices. She had a cavernous transformation of the portal vein with prehepatic portal hypertension associated with heretofore unreported malformations such as right pulmonary hypoplasia, cardiac dextroposition, and right renal ectopia. A unifying hypothesis (e.g. an intrauterine vascular insult) to explain the pathogenesis of these defects seems unlikely. Appropriate tests failed to identify specific functional abnormalities in these organs. Although she bled more than once, the combination of sclerotherapy and beta-blockers has been, thus far, able to control the major clinical consequences of this disease.

Scientific publications in gastroenterology and hepatology in Western Europe, USA and Japan in the years 1992-1996: a global survey

AIM

To evaluate number and quality of publications in gastroenterology, hepatology and digestive endoscopy from Western Europe (Belgium, Denmark, France, Germany, Great Britain, Italy, the Netherlands, Spain, Sweden, Switzerland), Japan and USA over a recent 5-year period.

METHODS

We screened by computer for full liver/gastrointestinal-related articles and reviews the top 40% of journals (according to the annual rating of the SCI Journal Citation Reports; Institute for Scientific Information database) in most clinical and basic science disciplines in the years 1992-1996. To be credited with an article, a given country had to be the site of the first institution where the work was conducted. Papers were rated according to the impact factor of the Institute for Scientific Information and to the ratio impact factor/mean European impact factor. Data were also normalized for nondefense research and development expenditure.

RESULTS AND CONCLUSIONS

As randomly tested, the computer search had an error of +/- 5-10%. In Europe, Great Britain achieved the highest total impact factor and the highest number of papers. Most of the British impact factor came from publications in British journals. The total USA impact factor exceeded that of Europe by 20%. The average impact factor for a single paper was highest for the USA and, in Europe, for Germany. The temporal trend of total impact factor showed Spain improving by 9% per year, with Germany and Italy also displaying a substantial growth. Expressed per funds allocated in nondefense research and development, Great Britain and the USA had the highest cumulative impact factor.

Molecular phylogeny of truffles (Pezizales: Terfeziaceae, Tuberaceae) derived from nuclear rDNA sequence analysis

Extensive morphological convergence or divergence, a common occurrence in fungi, tends to obscure recognition of phylogenetic relationships among Pezizales, widespread filamentous Ascomycetes with either enclosed underground (hypogeous) or exposed (epigeous) fruit bodies, that often establish mutualistic interactions with arboreous plants. Focusing on hypogeous Pezizales commonly known as truffles, we sequenced the 18S rDNA from nine species belonging to three different families (Tuberaceae, Terfeziaceae, and Balsamiaceae). A data set consisting of 1700 secondary structure-aligned sites, including 24 homologous sequences from the GenBank DNA database and using three reconstruction methods, was employed to infer phylogenies in an interval ranging from the subordinal to the subgeneric level. As revealed by the 18S phylogenetic scheme, Balsamiaceae represent a monophyletic clade, comprising the hypogeous taxa Balsamia and Barssia, nested within Helvellaceae. Similarly, the terfeziacean genera Pachyphloeus and Terfezia constitute together with Cazia a distinct hypogeous clade nested within Pezizaceae. The lack of clustering between Terfezia arenaria and Terfezia terfezioides strongly supports the reassignment of the latter taxon to the original monotypic genus Mattirolomyces. Within Tuberaceae, which are sister to the highly evolved Helvellaceae, the genus Tuber cannot be considered monophyletic if Choiromyces is recognized. The paraphyly of Tuber and other relationships that were not supported by high bootstrap values, nor corroborated by morphological evidence, were supported by a parallel analysis of the faster evolving internal transcribed spacer (ITS) rDNA. Distinct episodes of fruit body morphology shifts are discernable in the 18S rDNA phylogenetic tree. In all cases, the shift from an epigeous to a hypogeous form is the most parsimonious interpretation of character transformation, without any instance of character reversal.

[Ethical aspects of randomized clinical trials]

Randomized clinical trials represent the final, essential link between basic medical research and human health. However, their conduction presents very complex ethical problems, since the patient is the actual target of the experiment. Proper randomization, informed consent, and preliminary disclosure of results create deep ethical conflicts between the role of caretaker and that of impartial observer, both played by the same doctor. The dilemma reproduces the conflict between two different ethics. One is based on the inalienable individual rights stemming from the concept of man as an end in himself and not a means to an end. The other, derived from utilitarian philosophies, is based on the benefit for society as a whole. If we agree that randomized clinical trials represent the best method to test the validity of a new treatment, there is no easy solution. The dilemma could be solved by separating the role of the family doctor, committed to the best treatment possible for his patient, from the role of the scientist, committed to the progress of science and humanity. The former is involved in the treatment of individual patients, the latter in clinical and scientific experiments of a therapeutic nature. The patient may trade his rights to the best possible cure for the safety and the efficiency guaranteed by the scientific institution conducting the trial. Trials on relevant issues--expected to produce important results and impeccably designed scientifically--could be endowed with the ethics of science per se and this could be considered equivalent to the individual rights waived by the patient.

B-cell clonality and infection with Helicobacter pylori: implications for development of gastric lymphoma

BACKGROUND

Although Helicobacter pylori has been implicated in the pathogenesis of gastric mucosa associated lymphoid tissue (MALT) and MALT lymphoma, it is not known how it may trigger these lesions and whether there is an identifiable pre-neoplastic stage.

AIMS

To investigate the relation between MALT, H pylori infection, and B-cell clonality (a potential marker of pre-neoplastic lesions).

PATIENTS

141 subjects with simple dyspepsia.

METHODS

Gastric biopsy specimens from all patients were examined for MALT and H pylori. Of these, 25 consecutive MALT positive specimens were scored for features of MALT lymphoma and VDJ clonality studied by polymerase chain reaction.

RESULTS

Overall, prevalence was 62% for H pylori and 46% for MALT. VDJ clonality was frequent in the sub-group studied (nine of 25), mostly associated with lymphoid follicles (eight of nine or 89%), and with a high scoring for MALT lymphoma. VDJ clonality was equally frequent in patients with and without H pylori (seven of 20 and two of five or 35% and 40% respectively).

CONCLUSIONS

B-cell clonality is unexpectedly common in subjects with simple dyspepsia and MALT raising clinical management questions. These findings also suggest that the cascade MALT formation--B-cell clonality--MALT lymphoma may not be uniquely associated with H pylori infection.