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PubMed1992

[The endoscopic management of pancreatic pseudocysts: a case report].

The Authors present a case of post traumatic pseudocyst of the pancreas added to their observations and treated with an endoscopic cytogastric deviation. The incidence of such pathology has increased during the last few years thanks also to the improvement of the diagnostic techniques (TAC, U/S, Rm and eco-endoscopy) on hard today; in the second place the technological evolution has allowed, improving the diagnostic definition, the ability to heat pseudocysts, in selected patients, with minor surgery techniques with result equal to those of conventional surgery, but with complications and mortality decisively reduced. The morbidity and mortality rates of internal deviation surgery has respectively worsened varying between 21% and 50% and from 5% to 12%. The results of endoscopic deviations, even if the cases are less, report positive results from 80% to 100%, with complications and mortality greatly reduced. To be able to propose an endoscopic indication certain requirement are necessary of which one is indispensable: the distance between the two adjacent lumen must not be more than one centimeter. The Authors are of the opinion that such methods, in expert hand an on selected patients, should be the first surgical choice for the treatment of pancreatic pseudocysts.

Adult↗
PubMed1998

Spatial and temporal variations of herbicide (triazines and phenylureas) concentrations in the catchment basin of the Marne river (France).

Triazine and phenylurea concentrations were investigated in four sub-basins of the Marne river (France) in 1992 and 1993. The peak concentrations of atrazine, simazine and isoproturon occurred between March and July. In the four basins, the peaks were in relation with the herbicide application periods and with the important rainfalls, except for the isoproturon. The peaks of terbutryne and ametryne came later in the year, due to their use for weed control on post-emergent corn. For the phenylureas, the peak concentrations were observed in March-April next to the spraying period on winter cereals. The fast transfer of those herbicides was related to their high water solubility. In all the samples, the deethylatrazine (DEA) was detected 1 month after the atrazine due to its degradation within the soils which is of minor importance as compared to its transport by surface waters and also, to interactions between the silt sheet and the stream itself. The DAR evolution showed that the atrazine residence time depends both on the run-off in the first centimetres of the soil and on the treatment periods, particularly in the Grand Morin. The Marne river contamination level was similar to that of the Mélarchez and of the Grand Morin. The minor pollution of the Orgeval was related to minor cultivated areas.

Atrazine↗
PubMed2003

Evolution of surface and nonstructural-1 genes of influenza B viruses isolated in the Province of Québec, Canada, during the 1998-2001 period.

After 2 minor winter seasons, influenza B viruses were predominantly isolated in the Province of Quebec, Canada, during the 2000-2001 season representing 74% of laboratory-confirmed influenza viruses. We performed an antigenic study of the hemagglutinin (HA) protein and a molecular characterization of the HA1 region, nonstructural-1 (NS1) and neuraminidase (NA)/NB genes of 20 influenza B strains isolated in the Province of Quebec during the 1998-2001 period. Our isolates were compared to recent vaccine strains (B/Harbin/7/94 in 1998-1999, B/Yamanashi/166/98 in 1999-2000 and 2000-2001, and B/Sichuan/379/99 in 2001-2002). The hemagglutination inhibition (HI) test revealed that all isolates were different from B/Harbin/7/94 and were more related to the 2 other vaccine strains although precise identification was often impossible. Molecular analysis of the HA1 gene revealed that both B/Yamanashi/166/98-like and B/Sichuan/379/99-like isolates co-circulated during the 1998-1999 season whereas isolates from the 2 subsequent years were more related to B/Sichuan/379/99. Most isolates (8/9) of the 2000-2001 season contained a N126D substitution recently associated with altered antigenicity in recent influenza B/Yamagata/16/88-related viruses. Although the HA1 and NS1 protein sequences of viruses isolated during the 1998-1999 season were clearly different from those of the respective vaccine strain (B/Harbin/7/94), the NA protein sequence of those isolates was slightly more related to B/Harbin/7/94 than B/Yamanashi/166/98 suggesting distinct patterns of evolution for these genes. This study confirms the importance of a detailed molecular analysis for understanding the evolution of influenza B viruses.

Antigenic Variation↗
PubMed2001

Modulation of the regioselectivity of a Bacillus alpha-galactosidase by directed evolution.

Alpha-galactosidase AgaB of Bacillus stearothermophilus was subjected to directed evolution in an effort to modify its regioselectivity. The wild-type enzyme displays a major 1,6 and minor 1,3 regioselectivity. We used random mutagenesis and staggered extension process (StEP) to obtain mutant enzymes displaying modified regioselectivity. We developed a screening procedure allowing first the elimination of AgaB mutants bearing the 1,6 regioselectivity and secondly the selection of those retaining a 1,3 regioselectivity. Our results show that, among the evolved enzymes that have lost most of their activity towards the 1,6 linkage both in hydrolysis and in synthesis, one (E901) has retained its 1,3 activity. However the transglycosylation level reached by this mutant is quite low versus that of the native enzyme. This work constitutes the first example of modification of glycosylhydrolase regioselectivity by directed evolution.

Carbohydrate Conformation↗
PubMedDate not supplied

[Heart conduction disorders in pediatric practice].

This study was prepared on the basis of the recent data published in the specialized literature, as well as on the personal experience of the authors, and is considered as a necessary updating in the field of heart rhythm disturbances which occur in the child. A review is presented of sinoatrial blocks, of atrioventricular conduction disturbances, and of intraventricular conduction abnormalities (branch blocks). A modern classification is used in the discussion of sinoatrial, and of atrioventricular blocks, with the three distinctive degrees (first degree block, second degree block--with type I and type II variants, and the third degree block). The authors have attempted, in their effort to present the data concerning each of the entities, to include a series of anatomical and electrophysiological notions, some of which represent modern acquisitions obtained by endocavitary electrocardiographic exploration, and which are considered to be essential for a good understanding of the material. An important place is given--for each of the entities discussed--to the etiological study, as well as to clinical semiology, and electrocardiography, to problems related to the positive and differential diagnosis, and to therapeutical means, as well as to evolution and prognosis. The study is concluded by a presentation of intraventricular conduction disturbances (branch blocks) which are evaluated in their distinct variants: the monofascicular block (single bundle block), the bi- and trifascicular bundle blocks, major or minor blocks, and functional rate-dependent blocks. In these cases also the authors have analysed etiologic aspects, the clinical picture, and the electrocardiographic aspects, as well as therapeutical, evolutive and prognostic features for each of the different forms.

Arrhythmias, Cardiac↗
PubMedDate not supplied

[Clinical picture and evolution of hepatitis C].

Hepatitis C is becoming the main cause of cirrhosis and primary liver carcinoma. Infection by hepatitis C virus (HCV) generally induces an asymptomatic acute hepatitis. HCV infection becomes chronic in about 80% of cases. In a minority of the subjects, chronic HCV infection is asymptomatic with persistent viremia and normal liver tests. These asymptomatic subjects have minimal liver histologic lesions and a good prognosis. In a majority of the subjects, chronic HCV infection is associated with chronic hepatitis with increased serum transaminases levels. Among the patients with chronic hepatitis, the majority have a mild liver disease with a moderate increase in serum transaminases levels and, at liver histology, minimal lesions; a minority (about 20%) have a more severe liver disease and will develop cirrhosis after 5 to 20 years. In patients with HCV related cirrhosis, the incidence of hepatocellular carcinoma is high (around 5% per year). The factors influencing the evolution of HCV infection are not known. Alcohol is certainly an important factor which increases the risk of development of fibrosis then cirrhosis. Virus related factors, such as genotype and level of replication, might also be important. Autoimmune diseases have been reported in association with hepatitis C. HCV infection is a major cause of mixed cryoglobulinemia associated with vasculitis or glomerulonephritis. A relationship between HCV and auto-immune diseases such as thyroiditis or Gougerot syndrome has been suggested but not demonstrated. HCV infection is frequent in patients with porphyria cutanea tarda; in these patients, HCV related liver disease might trigger the expression of the metabolic disease.

Acute Disease↗
PubMed1998

Lindane degradation and effects on soil microbial activity.

The degradation of U-14C-lindane in two Egyptian soils was determined in a three-month laboratory incubation. Lindane mineralization was slow and limited in both soils. Evolution of 14CO2 increased with time but only reached 3.5 to 5.5% of the initial 14C-concentration within 90 days. At that time both soils contained about 88% of the applied radiocarbon; 33% to 37% of the initial dose was unextractable and assumed bound to the soils. The methanol-extractable 14C primarily contained lindane with traces of minor metabolites. Radiorespirometry was used to evaluate the effect of lindane on soil microbial activity. Low concentrations of the insecticide initially supressed 14CO2 evolution from U-14C-glucose and microbial activity was significantly inhibited by 10 mg lindane/kg soil.

Carbon Dioxide↗
PubMed2003

Chromatographic separation and in vitro activity of sorgoleone congeners from the roots of sorghum bicolor.

Sorgoleone, 2-hydroxy-5-methoxy-3-[(8'Z,11'Z)-8',11',14'-pentadecatriene]-p-benzoquinone (1), and its corresponding hydroquinone are the major components of the root exudate of Sorghum bicolor. The name sorgoleone includes minor analogues differing in the length or degree of unsaturation of the 3-alkyl side chain. These compounds are known to be phytotoxic, probably through inhibition of photosystem II (PSII) driven oxygen evolution, as previously demonstrated for 1. Isolation of these sorgoleone congeners was achieved by C(8) column chromatography and argentation thin-layer chromatography, and the purified compounds were structurally characterized. The abilities of the minor sorgoleones to inhibit PSII were similar to that of the major compound, suggesting that all of these sorgoleone congeners contribute to the overall allelopathy of sorghum.

Benzoquinones↗
PubMed2006

The distribution of HLA alleles revealed a founder effect in the geographically isolated Chinese population, Drung.

The Drung ethnic minority is one of the smallest ethnic groups of China, geographically isolated by mountains and rivers. Before 1949, Drung society maintained many vestiges of the primitive commune system. The origin and migration of the Drung and their genetic background are still unknown because of limited records about this population. Here, we for the first time demonstrated the unique distribution of HLA alleles in the Drung by high-resolution sequence-based typing (SBT) method. Number of alleles detected is obviously less than expected and only a few alleles with a high homozygosity in each locus are predominant in this minority. The characteristics of HLA allele distribution in the Drung could reflect founder effects, suggesting the Drung probably descended from very few ancestors. The statistical analysis based on allele frequencies indicated that the Drung was an isolated ethnic group, but it also provided the clue that the Drung was genetically related to Chinese southwestern ethnic groups. Significant reduced allelic diversity and genetic isolate in the Drung make it an ideal homogeneous population and very useful model to study the evolution of HLA and the origin and migration of Chinese ethnic groups. The research paved a way to elucidate the genetic background of this mysterious minority and disease predisposition.

Alleles↗
PubMed2001

Q-wave evolution of a first acute myocardial infarction without significant ST segment elevation.

BACKGROUND: Some patients with acute myocardial infarction presenting without significant ST segment elevation develop a Q-wave infarction. It is unclear whether these patients can be identified from the admission electrocardiogram (ECG) and whether they differ in their in-hospital prognosis from those who retain a non-Q-wave myocardial infarction. METHODS: In 432 consecutive patients admitted to our centre with a first acute myocardial infarction without Q waves and with ST segment amplitudes < or =0.1 mV on admission, we assessed the frequency, the electrocardiographic predictors and the short-term implications of a Q-wave evolution. RESULTS: In 94 patients (22%), a Q-wave myocardial infarction evolved before hospital discharge (14 anterior, 26 inferior, six lateral, and 48 posterior). Minor anterior ST segment elevation was 36% sensitive and 95% specific in predicting anterior Q waves; minor inferior ST segment elevation, 42% and 89%, respectively, for inferior Q waves; and a maximal ST segment depression > or =0.2 mV in leads V2-V3 with upright T waves and without remote ST segment depression, 38% and 97%, respectively, for posterior R waves. Although patients with a Q-wave evolution had a greater creatinkinase MB peak than those retaining a non-Q-wave pattern (191+/-113 vs. 105+/-77 IU/l, respectively, P<0.001), they experienced a benign in-hospital course, with similar risk of severe complications after adjustment for the baseline clinical predictors than non-Q-wave patients. CONCLUSIONS: About one fifth of patients with a first acute myocardial infarction without a significant ST segment elevation develop a Q-wave infarction and the admission ECG can help identify them. This evolution, however, is not associated with a worse in-hospital outcome.

Biomarkers↗
PubMed2004

Molecular phylogeny of the plant pathogenic genus Botrytis and the evolution of host specificity.

The cosmopolitan genus Botrytis contains 22 recognized species and one hybrid. The current classification is largely based on morphological characters and, to a minor extent, on physiology and host range. In this study, a classification of the genus was constructed based on DNA sequence data of three nuclear protein-coding genes (RPB2, G3PDH, and HSP60) and compared with the traditional classification. Sexual reproduction and the host range, important fitness traits, were traced in the tree and used for the identification of major evolutionary events during speciation. The phylogenetic analysis corroborated the classical species delineation. In addition, the hybrid status of B. allii (B. byssoidea x B. aclada) was confirmed. Both individual gene trees and combined trees show that the genus Botrytis can be divided into two clades, radiating after the separation of Botrytis from other Sclerotiniaceae genera. Clade 1 contains four species that all colonize exclusively eudicot hosts, whereas clade 2 contains 18 species that are pathogenic on either eudicot (3) or monocot (15) hosts. A comparison of Botrytis and angiosperm phylogenies shows that cospeciation of pathogens and their hosts have not occurred during their respective evolution. Rather, we propose that host shifts have occurred during Botrytis speciation, possibly by the acquisition of novel pathogenicity factors. Loss of sexual reproduction has occurred at least three times and is supposed to be a consequence of negative selection.

Base Sequence↗
PubMed1994

Koinophilia replaces random mating in populations subject to mutations with randomly varying fitnesses.

Koinophilia, the avoidance of sexual mates bearing strange phenotypic features, or displaying odd behaviour, would, if it evolved, profoundly influence the evolutionary process. A stochastic computer model was therefore devised to investigate the evolution of an initially rare koinophilic trait in panmictic populations, subject to mutations with randomly varying fitnesses. Individual genomes consisted of 50 genes. Mutations occurred at a rate of 0.005, 0.01 or 0.02 per gene per generation. The mean and maximum fitness of mutations could be varied, as could the proportion of beneficial mutations. The carriers of the koinophilic trait avoided, with adjustable degrees of intensity, mates displaying unusual phenotypic features (traits with population frequencies < 0.5); panmictic individuals mated randomly. The results show that koinophilia tends to replace panmixis whenever the preference for common phenotypic traits is strongly expressed, when few mutations are beneficial (1% instead of 10%), or when the maximum fitness of mutations is low (1.2 instead of 2.0). The mutation rate and mean fitness of mutations had only minor effects on the relative advantage of koinophilia.

Animals↗
PubMedDate not supplied

The development of the human foot as a résumé of its evolution.

The changes the human foot undergoes during its development are described as indications of structural and functional changes which might have occurred during the evolution of the vertebrate hind foot. The human foot, when compared to other vertebrate feet, appears to be a relatively minor modification of the plantigrade hind foot of the shrew-like insectivores that gave rise to all of the mammals. There is no developmental evidence to indicate that the first toe of the human foot was ever prehensile. Thus, the generally accepted evolutionary view, which depicts the feet of the early ancestors of modern human beings as having ape-like prehensile first toes, is seriously questioned.

Anatomy, Comparative↗
PubMed1995

Quantitative molecular methods in virology.

During the past few years, significant technical effort was made to develop molecular methods for the absolute quantitation of nucleic acids in biological samples. In virology, semi-quantitative and quantitative techniques of different principle, complexity, and reliability were designed, optimized, and applied in basic and clinical researches. The principal data obtained in successful pilot applications in vivo are reported in this paper and show the real usefulness of these methods to understand more details of the natural history of viral diseases and to monitor specific anti-viral treatments in real time. Theoretical considerations and practical applications indicate that the competitive polymerase chain reaction (cPCR) and competitive reverse-transcription PCR (cRT-PCR) assay systems share several advantages over other quantitative molecular methodologies, thus suggesting that these techniques are the methods of choice for the absolute quantitation of viral nucleic acids present in low amounts in biological samples. Although minor obstacles to a wide use of these quantitative methods in clinical virology still remain, further technical evolution is possible, thus making the quantitative procedures easier and apt to routine applications.

DNA, Viral↗
PubMed2006

The reaction of nitrogen atoms with methyl radicals: Are spin-forbidden channels important?

A computational study of the N(4S) + CH3 reaction has been carried out. The reactants approach through an attractive potential surface leading to an intermediate, H3CN, whose formation does not involve any barrier. In agreement with the experimental results, the dominant channel for this reaction is H2CN+H. The theoretically estimated rate coefficient for the overall process at 298 K is 9.1 x 10(-12) cm3 s(-1) molecule(-1), which is nearly 1 order of magnitude lower than the experimental result, but also much larger than those computed for the reactions of ground-state nitrogen atoms with halomethyl radicals. The analysis of the singlet potential energy surface, and the corresponding computational kinetic study, shows that for the reaction of excited nitrogen atoms with methyl radicals, the preferred product from the kinetic point of view is also H2CN+H, but in this case production of HCN is significant (with branching ratios around 0.185). According to our calculations, spin-forbidden processes are highly unlikely for the N(4S) + CH3 reaction. However, further evolution of the preferred products, H2CN+H, might explain the experimental observation of hydrogen cyanide as a minor product in this reaction.

Journal Article↗
PubMed2003

Pathogenesis of DNA repair-deficient cancers: a statistical meta-analysis of putative Real Common Target genes.

DNA mismatch repair deficiency is observed in about 15% of human colorectal, gastric, and endometrial tumors and in lower frequencies in a minority of other tumors thereby causing insertion/deletion mutations at short repetitive sequences, recognized as microsatellite instability (MSI). Evolution of tumors, including those with MSI, is a continuous process of mutation and selection favoring neoplastic growth. Mutations in microsatellite-bearing genes that promote tumor cell growth in general (Real Common Target genes) are assumed to be the driving force during MSI carcinogenesis. Thus, microsatellite mutations in these genes should occur more frequently than mutations in microsatellite genes without contribution to malignancy (ByStander genes). So far, only a few Real Common Target genes have been identified by functional studies. Thus, comprehensive analysis of microsatellite mutations will provide important clues to the understanding of MSI-driven carcinogenesis. Here, we evaluated published mutation frequencies on 194 repeat tracts in 137 genes in MSI-H colorectal, endometrial, and gastric carcinomas and propose a statistical model that aims to identify Real Common Target genes. According to our model nine genes including BAX and TGFbetaRII were identified as Real Common Targets in colorectal cancer, one gene in gastric cancer, and three genes in endometrial cancer. Microsatellite mutations in five additional genes seem to be counterselected in gastrointestinal tumors. Overall, the general applicability, the capacity to unlimited data analysis, the inclusion of mutation data generated by different groups on different sets of tumors make this model a useful tool for predicting Real Common Target genes with specificity for MSI-H tumors of different organs, guiding subsequent functional studies to the most likely targets among numerous microsatellite harboring genes.

Base Pair Mismatch↗
PubMed2002

Amplification of 'variola virus-specific' sequences in German cowpox virus isolates.

In 1995 a polymerase chain reaction (PCR) protocol describing the specific detection of variola virus, the causative agent of smallpox, was published by Knight and others. Virulent variola major strains could be differentiated from less virulent variola minor strains because of the distinct amplicon sizes. Here, we applied this PCR protocol to DNA from various orthopoxvirus isolates. There was no amplification with the orthopoxvirus species vaccinia, monkeypox, mousepox, or camelpox viruses. However, amplification was observed in six out of 15 cowpox virus strains investigated. The size of the amplicons corresponded exactly with the size described for variola minor strains and the nucleotide sequence identity accounted for 97%. Findings are discussed with respect to the evolution of orthopoxvirus species assuming that variola virus most probably stems from a rodent-transmitted cowpox virus-like progenitor.

Animals↗
PubMed2005

New techniques and technologies for pediatric cataract surgery.

PURPOSE OF REVIEW: This paper surveys the literature from April 2004 to April 2005 and addresses trends in pediatric cataract surgery techniques. RECENT FINDINGS: The evolution of pediatric cataract surgery continues, with many adult cataract surgical techniques being applied to children with minor technical adjustments. More and more, surgeons are implanting intraocular lenses in younger children. One of the most widely reported technologic advances in 2004-2005 was the use of hydrophobic acrylic intraocular lenses in children. Predicting axial growth, and refractive change that accompanies it, is one of the major remaining challenges for the long-term care of children who have had cataract surgery. SUMMARY: Automation and intraocular lenses have helped to provide better anatomic and functional outcome for cataract surgery in children. Two major challenges in the coming years will be to find a way to obviate invasive procedures like posterior capsulotomy and vitrectomy and to study the growth of eyes in a well designed prospective study that will help to design new intraocular lens power calculation formulas specifically suited for children's eyes.

Cataract Extraction↗